CN112305776B - Light field display system based on light waveguide coupling light exit pupil segmentation-combination control - Google Patents

Abstract

The invention discloses a light field display system based on optical waveguide coupled light exit pupil segmentation-combination control, which takes at least one optical waveguide projection unit for projecting images to a finite projection surface as a display unit, and respectively projects views with the viewpoint distance smaller than the diameter of the pupil of an observer to each eye of the observer by the regional segmentation-combination control of the coupled light exit pupil of the at least one optical waveguide projection unit and combining the polarization characteristic or/and the time sequence characteristic, and forms monocular naturally focusable space light spot distribution by utilizing the spatial superposition of light beams from more than one view, thereby realizing three-dimensional light field display. The display system has a light and thin structure by means of the optical waveguide, and can be applied to various screens and portable display terminals, such as head-mounted VR, AR, mobile phones, ipads, and the like.

Description

Light field display system based on light waveguide coupling light exit pupil segmentation-combination control

Technical Field

The invention relates to three-dimensional display, in particular to a light field display system based on optical waveguide coupling-out pupil segmentation-combination control.

Background

The optical waveguide is a commonly used optical structure in the field of three-dimensional display at present due to the advantage of light and thin structure volume. Especially in the field of Augmented Reality (AR), light and thin three-dimensional glasses based on an optical waveguide structure are being widely used. However, the existing optical waveguide three-dimensional display system is mainly based on a stereoscopic technology, and only one view is respectively projected to two eyes of an observer, and the three-dimensional depth is presented by utilizing the convergence of the two eye views in the space. But in order to see clearly the respective views of the binoculars, the viewer needs to focus his/her eyes on the display surface. The resulting focus-convergence conflict is inconsistent with the natural physiological response of the human eye to view a real three-dimensional scene. When a real object is observed naturally, the human eyes receive a cone-shaped light beam from a real object point, and the cone-shaped light beam enables the eyes of an observer to naturally focus on the object point while enabling the binocular vision of the observer to converge on the object point. This conflict of focusing and convergence, which is contrary to the natural physiological requirements of the human body, is the root cause of visual fatigue during three-dimensional viewing.

PCT15/481,467 (this-vision DISPLAY SYSTEM BASED ON vision multi-level OF THE VIEWER 'S ENTRANCE-PUPIL AND DISPLAY METHOD thermal) discloses a light field display technique that overcomes focus-convergence conflicts by projecting different views to different regions OF the observer's PUPIL, and forming a true spatial spot that can be naturally focused by a monocular by receiving a spatial superposition OF two or more view-emerging rays, to overcome focus-convergence conflicts. However, the display systems described in the above patents either require an external conventional large-sized flat display screen or are drawn to the near-to-eye region of the viewer through a conventional optical magnifying structure, and are not thin and light.

Disclosure of Invention

In order to realize light field three-dimensional display overcoming focusing-converging conflict in a light and thin structure, the invention provides the following scheme.

A light field display system based on the conventional optical waveguide coupled light exit pupil division-combination control comprises:

the conventional optical waveguide projection unit stack structure is formed by stacking G conventional optical waveguide projection units, each conventional optical waveguide projection unit projects a virtual image to the + z direction, and transmits the projected virtual image light information to the-z direction only through a coupling light exit pupil, wherein G is larger than or equal to 1;

the small-interval aperture array is composed of T groups of apertures capable of being switched in a time sequence, each aperture group comprises G apertures sequentially spaced by T-1 apertures, the aperture groups are arranged in front of each coupled exit pupil in the-z direction, of the G multiplied by T apertures, and the interval between adjacent apertures is smaller than the diameter D of the pupil of an observer_pThe T aperture groups are staggered one by one along the x direction, wherein T is not less than 1, and T multiplied by G is not less than 2;

in the stack structure of the conventional optical waveguide projection units, coupled light exit pupils of adjacent conventional optical waveguide projection units are sequentially staggered in the x direction and are arranged without overlapping with T apertures, each conventional optical waveguide projection unit respectively corresponds to T apertures from different aperture groups, which are arranged adjacently, and the conventional optical waveguide projection units emit light rays through the coupled light exit pupils to cover the T apertures corresponding to the conventional optical waveguide projection units and have no intersection with the apertures corresponding to other conventional optical waveguide projection units;

the control unit is used for controlling the T aperture groups to be opened in sequence only by one group at each T adjacent time points and controlling each conventional optical waveguide projection unit to synchronously project a view of a scene to be displayed relative to the corresponding opened aperture of the conventional optical waveguide projection unit;

and the diaphragm is arranged at the small-spacing aperture array and used for blocking the part of emergent light from each conventional optical waveguide projection unit, which is transmitted in the area except the corresponding aperture of the conventional optical waveguide projection unit.

Further, when the small-pitch aperture arrays are arranged at equal intervals Δ D along the x direction, the coupled-out pupils of the adjacent conventional optical waveguide projection units have an interval Δ D along the x direction which is T × Δ D, and the coupled-out pupils of each conventional optical waveguide projection unit have a width Δ W along the x direction which is less than T × Δ D.

Further, when the conventional optical waveguide projection units project virtual images to be adjacently connected on the projection plane, at a time point when only one aperture group is opened, the conventional optical waveguide projection units project virtual image loading information as different parts of a view, and a viewpoint of the view is an intersection point of the virtual image projected by each conventional optical waveguide projection unit and a straight line corresponding to the opened aperture.

Furthermore, the T apertures corresponding to the same conventional optical waveguide projection unit are switchable in the grouping, the opening timing of the T aperture groups is switchable, and the stacking sequence of the G conventional optical waveguide projection units is switchable.

Further, the conventional optical waveguide projection unit includes: the pixel array loads optical information required by the conventional optical waveguide projection unit synchronously and emits light beams; an optical waveguide composed of a substrate and a total reflection surface, for transmitting an incident beam by total reflection; an optical incoupling device that incouples incident light into the optical waveguide; the relay device is arranged between the pixel array and the light coupling-in device, phase-modulates each pixel of the pixel array to emit light beams, and draws the modulated light beams into the light coupling-in device; an exit pupil coupled out, an exit aperture through which the light is transmitted by the light guide; the optical out-coupling device modulates and guides the light transmitted by the optical waveguide through total reflection to be diverted to the out-coupling pupil; the image plane projection device is used for extending and converging light beams which are guided by the optical coupler out-coupling device and come from different pixels of the pixel array on each corresponding equivalent pixel on the projection plane along the + z direction in the opposite direction to form a virtual image of the pixel array on the projection plane, and the light beams emitted from the coupled light exit pupil are equivalent to the virtual image equivalent emergent light beams; and the compensation unit is arranged behind the light out-coupling device along the-z direction and used for reversely eliminating the influence of other devices on the incident light of the external environment.

Further, the stacked conventional optical waveguide projection units share the image plane projection device or/and the compensation unit.

Further, the pixel array is an OLED microdisplay, an LED microdisplay, an LCOS microdisplay, or a reflective surface that reflects external projected information, the optical waveguide is a planar optical waveguide, the optical coupler-in device is a micro-structural grating etched on the surface of the optical waveguide by a micromachining process, or a holographic grating exposed in the optical waveguide, or a mirror coated on the surface of the optical waveguide, or a diffraction grating attached on the surface of the optical waveguide, the relay device is a collimating lens, or an imaging lens, or/and a beam deflector, the optical coupler-out device is an embossed optical element etched on the surface of the optical waveguide, or a reflective surface array processed in the substrate of the optical waveguide, or a holographic grating exposed on the substrate of the optical waveguide, the image plane projection device is a concave lens, or a holographic grating exposed on the exit pupil plane of the optical waveguide, the compensation unit is a phase film, or a relief element, the compensating unit being attached to the surface of the optical waveguide, or being etched on the surface of the optical waveguide, or being exposed to the surface of the optical waveguide.

Further, the conventional optical waveguide projection unit is a frequency division multiplexing conventional optical waveguide projection unit formed by stacking three monochromatic conventional optical waveguide projection units, the wavelengths of projected light information of the three monochromatic conventional optical waveguide projection units are different, the coupled light exit pupils of the three monochromatic conventional optical waveguide projection units are overlapped, an image plane projection device or/and a compensation unit are shared, and projected superposed virtual images with different wavelengths are mixed and synthesized into a color virtual image.

The present application also provides the following alternative.

The light field display system based on the light-polarization characteristic light waveguide coupling light exit pupil segmentation-combination control is characterized by comprising the following components:

the polarization characteristic optical waveguide projection unit stack structure is formed by stacking G polarization characteristic optical waveguide projection units, each polarization characteristic optical waveguide projection unit projects a virtual image to the + z direction, and the projected virtual image light information is transmitted to the-z direction only through the coupled light exit pupil, wherein G is not less than 1;

in the stack structure of the polarized light characteristic optical waveguide projection units, each polarized light characteristic optical waveguide projection unit projects a virtual image and consists of S sub-regions along the x direction, equivalent emergent light polarization states of the same polarized light characteristic optical waveguide projection unit on adjacent sub-regions project the virtual image are mutually orthogonal, equivalent emergent light polarization states of adjacent polarized light characteristic optical waveguide projection units on sub-regions with the same sequence number along the x direction project the virtual image and are mutually orthogonal, wherein S is larger than or equal to 1;

small-spacing aperture array with T x (S + G-1) adjacent spacing along x direction smaller than pupil diameter D of observer_pThe aperture composition is arranged in front of each coupling light exit pupil along the-z direction, S + G-1 apertures with T-1 apertures are arranged in groups respectively, the T aperture groups in the group are staggered along the x direction by one aperture, the polarization states of passing light are orthogonal when adjacent apertures in each aperture group are opened, and the S apertures adjacent to each other in each aperture group are grouped secondarily respectively to construct and form G aperture subgroups, wherein T is not less than 1, and T multiplied by G is not less than 2;

in the stack structure of the polarization characteristic optical waveguide projection units, coupling exit pupils of adjacent polarization characteristic optical waveguide projection units are sequentially staggered with T apertures along the x direction, G polarization characteristic optical waveguide projection units with the coupling exit pupils sequentially staggered correspond to G aperture subgroups in each aperture group, wherein the S apertures of each aperture subgroup correspond to S subregions of the corresponding polarization characteristic optical waveguide projection units one by one in the same direction, and the polarization direction of emergent light is allowed to be consistent with the polarization direction of equivalent emergent light of the corresponding subregion when each aperture is opened;

the control unit is used for controlling only one group of the T aperture groups to be opened at each T adjacent time points and controlling each polarized light characteristic optical waveguide projection unit to synchronously project a view of a scene to be displayed relative to the corresponding opened aperture subgroup of the polarized light characteristic optical waveguide projection unit;

the view point of the projection unit is the intersection point of the straight lines respectively passing through each sub-area of the projection unit of the polarized light characteristic optical waveguide and the corresponding aperture of the sub-area in the opening aperture subgroup;

and the diaphragm is attached to the small-distance aperture array and blocks the part of the emergent light from each polarization characteristic optical waveguide projection unit, which is transmitted in the area except the corresponding aperture of the polarization characteristic optical waveguide projection unit.

Furthermore, the sub-regions of the virtual images projected by the polarization characteristic optical waveguide projection units are overlapped, and the equivalent emergent light polarization states of the virtual images projected by the adjacent polarization characteristic optical waveguide projection units on the same overlapped sub-region are mutually orthogonal.

Further, the sub-regions are arranged at equal intervals, and the apertures are arranged at equal intervals Δ D, the coupling exit pupil of the adjacent polarization characteristic optical waveguide projection units is arranged at an x-direction interval Δ D ≦ T × S × Δ D, and the coupling exit pupil of each polarization characteristic optical waveguide projection unit is arranged at an x-direction width Δ W ≦ T × S × Δ D;

further, the polarization characteristic optical waveguide projection unit projects a view of a scene to be displayed about a corresponding open aperture subgroup, and the viewpoint of the view is the intersection point of the center of each sub-region of the polarization characteristic optical waveguide projection unit and the connecting line of the sub-region at the center of the corresponding aperture in the open aperture subgroup.

Furthermore, the attribution of the T apertures of the same sub-region of the polarization characteristic optical waveguide projection unit in the T groups of apertures is switchable.

Further, the states at respective time points in one period are switchable, and the stacking order of the G polarization characteristic optical waveguide projection units is switched.

Further, the polarization characteristic optical waveguide projection unit includes: the pixel array consists of S areas, and the emergent light polarization state of each area is consistent with the equivalent emergent light polarization state of a corresponding sub area on the virtual image projected by the light guide projection unit with the polarization characteristic; the optical waveguide consists of a substrate and a total reflection surface and transmits incident beams through total reflection keeping the polarization state of the incident beams unchanged; an optical incoupling device for incoupling the polarized light of the incident light into the optical waveguide; the relay device is arranged between the pixel array and the light coupling-in device, phase-modulates outgoing light beams of each pixel of the pixel array while keeping a polarization state unchanged, and draws the modulated light beams into the light coupling-in device; an outcoupled light exit pupil, the optical waveguide transmitting a light exit aperture; the optical coupler is used for modulating and guiding the polarized state of the light beam transmitted by the optical waveguide through total reflection to be invariably turned to the coupled light exit pupil; the image plane projection device is used for extending and converging light beams which are guided by the light coupling-out device and come from different pixels of the pixel array on each corresponding equivalent pixel on the projection plane along the + z direction in a reverse direction to form a virtual image of the pixel array on the projection plane, and the light beams which are emitted from the coupled light exit pupil are equivalent to the equivalent emergent light beams of the virtual image; and the compensation unit is arranged behind the light out-coupling device along the-z direction and used for reversely eliminating the influence of other devices on the incident light of the external environment.

Further, the stacked polarization characteristic optical waveguide projection units share the image plane projection device or/and the compensation unit.

Furthermore, the polarization characteristic optical waveguide projection unit is a complex structure polarization characteristic optical waveguide projection unit formed by stacking M + N conventional optical waveguide projection units, the coupled-out pupil of each conventional optical waveguide projection unit is one or more than one spaced-apart coupled-out pupil, wherein M conventional optical waveguide projection units are combined into an coupled-out pupil array, each coupled-out pupil is respectively provided with a corresponding polarization film with a size not smaller than the size of the coupled-out pupil, the number, position and polarization direction of the polarization films corresponding to the coupled-out pupil array are consistent with the number, position and polarization direction of one polarization property aperture in the apertures corresponding to the polarization characteristic optical waveguide projection unit, the other N conventional optical waveguide projection units are combined into another coupled-out pupil array, each coupled-out pupil is respectively provided with a corresponding polarization film with a size not smaller than the size of the coupled-out pupil, the number, the position and the polarization direction of the polarization films corresponding to the exit pupil array are consistent with the number, the position and the polarization direction of the other polarization property aperture in the corresponding aperture of the polarization property optical waveguide projection unit, M is not less than 1, and N is not less than 1.

Further, in the complex-structured polarization characteristic optical waveguide projection unit, the M + N stacked conventional optical waveguide projection units share the image plane projection device or/and the compensation unit.

The present application also provides the following alternative.

The light field display system based on time sequence characteristic light waveguide coupled light exit pupil segmentation-combination control is characterized by comprising the following components:

the time sequence characteristic optical waveguide projection unit stack structure is formed by stacking G time sequence characteristic optical waveguide projection units, each time sequence characteristic waveguide projection unit projects a virtual image which is divided into S sub-areas along the x direction to the + z direction, and the projected virtual image light information is transmitted to the-z direction only through a coupled light exit pupil of the time sequence characteristic waveguide projection unit, wherein G is larger than or equal to 1, and S is larger than or equal to 2;

small-spacing aperture array with T x (S + G-1) adjacent spacing along x direction smaller than pupil diameter D of observer_pThe aperture composition of (1) is arranged in front of each coupling light exit pupil along the-z direction, S + G-1 apertures with intervals of T-1 apertures are respectively grouped, T aperture groups in the group are staggered by one aperture along the x direction, in each aperture group, every adjacent S apertures are respectively grouped into an aperture subgroup for the second time to form a T multiplied by G aperture subgroup, wherein T is not less than 1, and T multiplied by G is not less than 2;

in the time sequence characteristic optical waveguide projection unit stack structure, coupling exit pupils of adjacent time sequence characteristic optical waveguide projection units are sequentially staggered by T apertures along the x direction, G time sequence characteristic optical waveguide projection units with sequentially staggered coupling exit pupils respectively correspond to G aperture subgroups sequentially staggered in the same direction in each aperture group, and S apertures of each aperture subgroup correspond to S sub-regions of the corresponding time sequence characteristic optical waveguide projection units in the same direction one by one;

the control unit is used for opening only one aperture cluster consisting of apertures at intervals of V-1 apertures in sequence in only one aperture group at one time point, and controlling the T multiplied by V different aperture clusters of all the aperture groups to be opened only one cluster at a time at adjacent T multiplied by V time points within each time period delta T, wherein V is less than or equal to 2 and less than or equal to S;

when one aperture is opened, the corresponding sub-area on each time sequence characteristic optical waveguide projection unit is controlled to load information related to the aperture, and the sub-area corresponding to the unopened aperture is not loaded with information;

the information of the sub-area of the time sequence characteristic optical waveguide projection unit about one aperture is the information of a virtual image area of the time sequence characteristic optical waveguide projection unit about the view of the aperture subgroup where the aperture is located on the sub-area;

the view of the virtual image area of the time sequence characteristic optical waveguide projection unit about one aperture subgroup is that the viewpoint of the view is the intersection point of the straight lines which respectively pass through each sub-area of the time sequence characteristic optical waveguide projection unit and the corresponding aperture of the sub-area in the aperture subgroup;

and a diaphragm attached to the small-pitch aperture array and blocking a portion of the light emitted from each of the timing characteristic optical waveguide projection units, which portion is transmitted through a region other than the aperture corresponding to the timing characteristic optical waveguide projection unit.

Further, when the sub-regions are arranged at equal intervals and the apertures are arranged at equal intervals Δ D, the coupling pupil of the adjacent timing characteristic optical waveguide projection units has an x-direction interval Δ D ≦ T × S × Δ D, and the coupling pupil of each timing characteristic optical waveguide projection unit has an x-direction width Δ W ≦ T × S × Δ D.

Further, a view of the virtual image region of the time-series characteristic optical waveguide projection unit with respect to one aperture sub-group is a view of the time-series characteristic optical waveguide projection unit from a viewpoint of the time-series characteristic optical waveguide projection unit projecting an intersection of the center of each sub-region of the virtual image and a line connecting the sub-region with the corresponding aperture center in the aperture sub-group.

Further, the time-series characteristic optical waveguide projection unit includes: the pixel array consists of S areas, synchronously loads the projection information required by the time sequence characteristic optical waveguide projection unit and emits light beams; an optical waveguide composed of a base and a total reflection surface for transmitting an incident beam by total reflection; an optical incoupling device to couple incident light into the optical waveguide; the relay device is arranged between the pixel array and the light coupling-in device, phase-modulates each pixel of the pixel array to emit light beams, and draws the modulated light beams into the light coupling-in device; an outcoupled light exit pupil, the optical waveguide transmitting a light exit aperture; the optical out-coupling device modulates and guides the light beams transmitted by the optical waveguide through total reflection to be turned to an out-coupling pupil; the image plane projection device is used for extending and converging light beams which are guided by the light coupling-out device and come from different pixels of the pixel array on each corresponding equivalent pixel on the projection plane along the + z direction in a reverse direction to form a virtual image of the pixel array on the projection plane, and the light beams which are emitted from the coupled light exit pupil are equivalent to the equivalent emergent light beams of the virtual image; and the compensation unit is arranged behind the light out-coupling device along the-z direction and used for reversely eliminating the influence of other devices on the incident light of the external environment.

Further, the stacked time-series characteristic optical waveguide projection units share the image plane projection device or/and the compensation unit.

Further, the state of T × V time points in each time period is switchable, and the stacking order of the G timing characteristic optical waveguide projection units is switchable.

The present application also provides the following alternative.

The light field display system based on the polarized light time sequence characteristic light waveguide coupling light exit pupil segmentation-combination control is characterized by comprising the following components:

the polarization time sequence optical waveguide projection unit stack structure is formed by stacking G polarization time sequence optical waveguide projection units, each polarization time sequence optical waveguide projection unit projects a virtual image to the + z direction, and the projected virtual image light information is transmitted to the-z direction only through a coupling light exit pupil, wherein G is not less than 1;

the polarization time sequence optical waveguide projection unit stack structure is characterized in that each polarization time sequence optical waveguide projection unit projects a virtual image and consists of S sub-regions along the x direction, equivalent emergent light polarization states of the same polarization time sequence optical waveguide projection unit on adjacent sub-regions project the virtual image and are mutually orthogonal, equivalent emergent light polarization states of adjacent polarization time sequence optical waveguide projection units on sub-regions with the same sequence number along the x direction project the virtual image and are mutually orthogonal, wherein S is larger than or equal to 1;

small-spacing aperture array with T x (S + G-1) adjacent spacing along x direction smaller than pupil diameter D of observer_pThe aperture components are arranged in front of each coupling light exit pupil along the-z direction, S + G-1 apertures with T-1 apertures are respectively grouped, the T groups of apertures are staggered along the x direction, the adjacent apertures in each group of apertures allow the polarization states of light to pass through to be orthogonal when being opened, and the adjacent S apertures in each group of apertures are respectively secondarily grouped to form G aperture subgroups, wherein T is not less than 1, and T multiplied by G is not less than 2;

in each aperture group, starting from a first aperture along the x direction, the most adjacent apertures with different polarization states form a first mixed aperture, then in the aperture group, starting from the first aperture after the first mixed aperture, the same method defines a second mixed aperture, and the steps are repeated to determine all mixed apertures in the aperture group;

in the polarization time sequence optical waveguide projection unit stack structure, coupling exit pupils of adjacent polarization time sequence optical waveguide projection units are sequentially arranged in a staggered T-aperture mode along the x direction, G polarization time sequence optical waveguide projection units with the coupling exit pupils sequentially staggered correspond to G aperture sub-groups in each aperture group, the G aperture sub-groups are sequentially staggered in the same direction, S apertures of each aperture sub-group correspond to S sub-regions of the corresponding polarization time sequence optical waveguide projection units in the same direction one by one, and the polarization direction of emergent light is allowed to be consistent with the polarization direction of equivalent emergent light of the corresponding sub-regions when each aperture is opened;

the control unit is used for opening only one aperture cluster formed by mixed apertures at intervals of V-1 mixed apertures in only one aperture group at one time point, controlling T multiplied by V different aperture clusters of all aperture groups to be opened at adjacent T multiplied by V time points in each time period delta T in sequence, and opening only one aperture cluster at one time point, wherein V is more than or equal to 2 and less than or equal to [ (S +1)/2], [ ] is an integer symbol;

when one aperture is opened, the corresponding sub-regions are controlled to load information;

the loading information of the sub-region corresponding to one aperture is information of a view of a polarized light time sequence optical waveguide projection unit projection virtual image region corresponding to the sub-region, wherein the view of the aperture sub-group corresponding to the polarized light time sequence optical waveguide projection unit belongs to the aperture, on the sub-region;

the view point of the virtual image region projected by the polarized light time sequence optical waveguide projection unit is the intersection point of each sub-region of the virtual image projected by the polarized light time sequence optical waveguide projection unit and the straight line of the sub-region corresponding to the aperture in the aperture subgroup;

and the diaphragm is attached to the small-distance aperture array and used for blocking the part of emergent light from each polarization time sequence optical waveguide projection unit, which is transmitted in the area except the corresponding aperture of the polarization time sequence optical waveguide projection unit.

Furthermore, the sub-regions of the virtual images projected by the polarization time sequence optical waveguide projection units are overlapped, and the equivalent emergent light polarization states of the virtual images projected by the adjacent polarization time sequence optical waveguide projection units on the same overlapped sub-region are mutually orthogonal.

When the sub-regions are arranged at equal intervals and the apertures are arranged at equal intervals Δ D, the coupled-out pupils of the adjacent polarization time-sequential optical waveguide projection units have an x-direction interval Δ D ≦ T × S × Δ D, and the width Δ W of the coupled-out pupil of each polarization time-sequential optical waveguide projection unit along the x-direction is ≦ T × S × Δ D.

Further, the polarization time-series optical waveguide projection unit projects a view of the virtual image region with respect to the corresponding aperture sub-group, with a viewpoint being an intersection of the center of each sub-region of the virtual image projected by the time-series characteristic optical waveguide projection unit and a line connecting the center of the corresponding aperture in the aperture sub-group.

Further, the polarization time-series optical waveguide projection unit and the polarization characteristic optical waveguide projection unit are configured to have the same optical structure.

Further, the states of T × V time points in each time period are switchable, and the stacking order of the G polarization time-sequential optical waveguide projection units is switchable.

On the basis of a display method for realizing monocular multi-view light field display by 'projecting different views to different areas of a pupil of an observer' disclosed in PCT15/481,467, a light guide and other optical components form a light guide projection unit as an image transmission display means, and a light and thin three-dimensional display system based on a light guide stack structure is disclosed. Compared with the thick and heavy three-dimensional light field display system of PCT15/481,467, the display system of the present application adopts the optical waveguide structure, has a very thin and light characteristic, and can be applied to various screens and portable display terminals, such as head-mounted VR, AR, mobile phone, iPad, and the like. More importantly, the stacking of multiple optical waveguides in this patent is equivalent to providing multiple display devices (pixel arrays), which greatly improves the bandwidth of the display system and facilitates the implementation of high-quality monocular multiview compared to the case where a monocular corresponds to only one display device in the system described in PCT15/481,467. On the other hand, in the conventional optical waveguide stack AR system, the coupled light exit pupils of the stacked optical waveguides are all designed to be completely overlapped, such as PCT/2013/045267(Multiple depth-display using a wave guide reflective array projector) which suppresses the focus convergence conflict by projecting Multiple display surfaces to different spatial depths. The area division-combination control of the coupled-out pupil of the optical waveguide projection unit is realized by the design arrangement of the size of the output pupil and the error amount of the output pupil of each optical waveguide in the stack or/and the area division multiplexing of the coupled-out pupil of each optical waveguide in the stack through an externally introduced aperture array. Therefore, the structural design of the system components and the stacked optical waveguides in the present patent is different from the structural design of the constituent devices and the stacked optical waveguides in the existing lightwave stacked AR system. And the polarization characteristics and timing characteristics of the pixel array (display device) introduced in this patent are not discussed in the prior patent.

The invention has the following technical effects: the light field display system based on the optical waveguide coupling light exit pupil division-combination control realizes the monocular and multiview three-dimensional light field display of an observer through the area division-combination control of the coupling light exit pupil of at least one optical waveguide projection unit and the combination of the polarization characteristic or/and the time sequence characteristic. On the basis of overcoming the inherent focusing-converging conflict of the traditional stereoscopic three-dimensional technology, the three-dimensional stereo display has the characteristics of thinness and thinness, and can be applied to various screens and portable display terminals, such as head-mounted VR, AR, mobile phones and iPad.

The details of embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings.

Drawings

The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments and together with the description serve to explain the principles of the invention.

Fig. 1 shows an example of a conventional optical waveguide projection unit structure.

Fig. 2 shows another example of a conventional optical waveguide projection unit structure.

Fig. 3 shows a stacked structure of optical waveguide projection units with overlapping coupled-out pupils.

Fig. 4 shows a stacked structure of an optical waveguide projection unit with a partially overlapped exit pupil and a staggered optical waveguide.

Figure 5 shows a stacked structure of an optical waveguide projection unit of the coupled-out pupil partially overlapping-optical waveguide alignment type.

Fig. 6 shows a stacked structure of coupled-pupil non-overlapping optical waveguide misaligned optical waveguide projection units.

Fig. 7 shows the optical structure of a conventional optical waveguide projection unit stack-time division multiplexed display system.

Fig. 8 is a view of a conventional optical waveguide projection unit stack-time division multiplexing display system loaded at time t.

Fig. 9 is a view of the aperture corresponding to the view point distribution region.

FIG. 10 shows a conventional optical waveguide projection unit stack-TDM display system at time t + Δ t/2.

Fig. 11 observer pupil to small pitch aperture array spacing effect on display system optical parameters.

Fig. 12T-1 shows a conventional optical waveguide projection unit stack-time division multiplexed display system.

Fig. 13S-1 conventional optical waveguide projection unit stack-time division multiplexed display system.

Fig. 14 is a frequency division multiplexing conventional optical waveguide projection unit.

Fig. 15 is an optical structure of a polarization characteristic optical waveguide projection unit stack-time division multiplexing display system.

Fig. 16 is a view of a polarization characteristic optical waveguide projection unit stack-time division multiplexing display system loaded at time t.

FIG. 17 is a view of a polarization characteristic optical waveguide projection unit stack-TDM display system at time t + Δ t/2.

Fig. 18 is a projection unit of a light guide having a complex structure and polarization characteristics.

Fig. 19 shows a time-sequential characteristic optical waveguide projection unit stack-time division multiplexing display system operating at a time point.

Fig. 20 shows a time-sequential characteristic optical waveguide projection unit stack-time division multiplexing display system operating at another point in time.

FIG. 21 is a stacked-TDM display system of a polarization sequential optical waveguide projection unit.

Detailed Description

The display system takes the stack structure of the optical waveguide projection units as the optical information transmission and projection structure, the splitting-combination control of the coupled light exit pupil of each optical waveguide projection unit is combined with the polarization characteristic or/and the time sequence characteristic, and each optical waveguide projection unit respectively projects corresponding views with the viewpoint distance smaller than the diameter of the pupil of an observer to each eye of the observer through different coupled light exit pupils or different areas of different coupled light exit pupils. The light field three-dimensional display system with the light and thin optical structure is built by utilizing the spatial superposition of different view emergent rays received by each eye and based on stacked film-shaped optical waveguides. Compared with the monocular multi-view light field display system disclosed in PCT15/481,467, the optical waveguide projection unit of the present invention, which is composed of a film-shaped optical waveguide and other optical components, is used as an image transmission display means, and has a light and thin characteristic due to the adoption of the optical waveguide structure. More importantly, the stacking of multiple optical waveguides in this patent is equivalent to providing multiple display devices (pixel arrays), which greatly improves the bandwidth of the display system and facilitates the implementation of high-quality monocular multiview compared to the case where a monocular corresponds to only one display device in the system described in PCT15/481,467. On the other hand, the exit pupils of the stacked optical waveguides in the conventional optical waveguide stacked AR system are completely overlapped, such as PCT/2013/045267, which suppresses focus convergence conflicts by projecting multiple display surfaces to different depths in space. The area division-combination control of the coupled exit pupil of the optical waveguide projection unit is realized by stacking the design arrangement of the exit pupil size and the exit pupil displacement of each optical waveguide projection unit or/and stacking the area division multiplexing of the coupled exit pupil of each optical waveguide projection unit through an externally introduced aperture array. In contrast, the structural design of the system components and the stacked optical waveguides in the present patent is completely different from the structural design of the components and the stacked optical waveguides in the conventional optical waveguide stacked AR system. And the polarization characteristics and timing characteristics of the pixel array (display device) introduced in this patent are not discussed in the prior patent.

Fig. 1 shows a conventional opticalwaveguide projection unit 101, which is a conventional optical waveguide projection unit, commonly used in the field of optical displays.

Thepixel array 1101, theoptical waveguide 1301, therelay device 1201a, theoptical coupler device 1201b, theoptical coupler device 1501, the imageplane projection device 1701 and thecompensation unit 1801 are mainly included. Thepixel array 1101 is constituted by pixels, and light information is synchronously loaded and a light beam is emitted. Theoptical waveguide 1301, a two-dimensional optical waveguide, is composed of a base body andtotal reflection surfaces 1401a and 1401b, and transmits an incident beam by total reflection. Theoptical coupler 1201b may be a micro-structured grating etched on the surface of the optical waveguide by a micro-machining process, or a holographic grating exposed in the optical waveguide, or a mirror coated on the surface of the optical waveguide, or a diffraction grating attached to the surface of the optical waveguide, to couple incident light into theoptical waveguide 1301. Therelay device 1201a is disposed between thepixel array 1101 and theoptical coupler device 1201b, and may be a collimating lens, which collimates the outgoing light beam of each pixel of thepixel array 1101 and draws the collimated light beam into theoptical coupler device 1201 b. Therelay device 1201a may also be a reflective imaging device, imaging thepixel array 1101 to anoptical coupler device 1201b, or include a mirror for steering. The light out-coupling device 1501 is a relief optical element etched on the surface of the optical waveguide, or a reflecting surface array etched in the optical waveguide substrate through a micromachining process, or a holographic grating exposed on the optical waveguide substrate, and modulates and guides light transmitted by the total reflection of theoptical waveguide 1301 to be diverted to the light out-coupling pupil 1601. In the drawings of the present patent, the coupling-out pupil 1601 is indicated by a dotted line to be distinguished from thetotal reflection surface 1401 b. Light beams from different pixels of thepixel array 1101 are guided to enter and exit thepupil 1601 along the-z direction, and then pass through the imageplane projection device 1701 to form a virtual image along the + z direction on theprojection plane 1901, so that a virtual image 1101' of thepixel array 1101 on theprojection plane 1901 is formed. In a common case, collimated light beams from different pixels of thepixel array 1101 are incident and coupled out of theexit pupil 1601 along the-z direction at respective corresponding angles while maintaining the collimated light state, and then are extended in the + z direction via the imageplane projection device 1701 to converge on each corresponding equivalent pixel on theprojection plane 1901, thereby forming a virtual image 1101' of thepixel array 1101 on theprojection plane 1901. The light beam exiting from the coupled-out exit pupil may be equivalently referred to as a light beam exiting equivalently from the virtual image 1101' according to the object-image relationship. Thecompensation unit 1801 is disposed behind the optical coupler out-coupling device along the-z direction, and is configured to reversely eliminate the influence of other devices of the optical waveguide projection unit on incident light of an external environment, so as to implement superposition and fusion between a display scene and an external real scene, which are often required for augmented reality AR. When an external real scene is not required, thecompensation unit 1801 may be replaced by an additional light shielding device, such as a light shielding film. This common sense operation, not shown in fig. 1, is not described in detail below. In fig. 1, therelay device 1201a is embodied as a collimator lens, and converts light emitted from each pixel of thepixel array 1101 into parallel beams having different propagation directions. Theoptical coupler 1201b is embodied as a holographic grating exposed to theoptical waveguide 1301, and couples parallel light beams in different propagation directions input through therelay device 1201a into theoptical waveguide 1301, so that each coupled light beam is at least partially propagated to theoptical coupler 1501 through total reflection in theoptical waveguide 1301. Theoutcoupling device 1501 is embodied as a holographic grating exposed to the membrane, which is attached to the surface of theoptical waveguide 1301. The light coupling-out device 1501 modulates the light beam propagating through thelight guide 1301 based on total reflection, so that the propagation direction of the light beam is turned to the coupling-out pupil 1601 in the-z direction. In FIG. 1, the-z direction and the x direction are schematically shown in a perpendicular relationship. In fact, they may be in a non-perpendicular relationship, where the light beam traveling in the x-direction is modulated by the light-outcoupling device 1501 to travel in the-z-direction, which is non-perpendicular to x. This situation is easily understood, and the z direction and the x direction in the following embodiment diagrams are both illustrated as a vertical relationship, and the non-vertical case will not be described repeatedly. The imageplane projection device 1701 in fig. 1 is embodied as a concave lens, and transmits each pixel of thepixel array 1101 as a parallel light beam, and the parallel light beam is extended and converged to a corresponding virtual image point of the pixel on theprojection plane 1901 along the + z direction. Thecompensation unit 1801 is embodied as a relief device.

Fig. 2 shows another conventional opticalwaveguide projection unit 101, which is different from fig. 1 mainly in that thelight incoupling device 1201b is a reflecting surface, and thelight outcoupling device 1501 is a semi-transparent and semi-reflecting surface array disposed in theoptical waveguide 1301 and distributed along the x direction. For clarity and simplicity of illustration, only half-transparent reflective surfaces 1501a3 and 1501a7 are labeled in fig. 2. In addition, thecompensation unit 1801 in fig. 2 is also exemplified as a separate phase film attached to the optical waveguide, and the imageplane projection device 1701 is a separate holographic phase grating, and functions like an imaging function of a concave lens.

Fig. 1 and 2 depict two common conventional opticalwaveguide projection units 101. In fact, various optical waveguides and combinations of components having the following functions can be used as the conventional opticalwaveguide projection unit 101 in the present document: the display pattern of thepixel array 1101 is transmitted through theoptical waveguide 1301, is virtually imaged to theprojection surface 1901 along the + z direction by means of other optical devices, and transmits virtually imaged equivalent outgoing light only through the coupled-out exit pupil along the-z direction. When the virtual images projected by these optical waveguide assemblies further have polarization characteristics and/or timing characteristics described below in this patent, the virtual images may be used as the polarization characteristic opticalwaveguide projection unit 301, the timing characteristic opticalwaveguide projection unit 501, or the polarization timing opticalwaveguide projection unit 601 in this document.

More than one optical waveguide projection unit can be superposed into an optical waveguide projection unit stack structure. Fig. 3 illustrates an example of stacking 3 conventional opticalwaveguide projection units 101, 102, and 103 into a conventional optical waveguide projectionunit stack structure 10. Their coupled-outlight exit pupils 1601, 1602 and 1603 are aligned coincident in the x-direction. For clearer illustration, some components of each conventional optical waveguide projection unit are not shown in the drawings. In fig. 3, imageplane projection devices 1701, 1702 and 1703 are common, andcompensation units 1801, 1802 and 1803 are common. The total reflection surface of the optical waveguide totally reflects light transmitted in the optical waveguide, but has higher transmittance for light transmitted at a certain deviation angle along the-z direction because the incident angle of the light does not meet the requirement of total reflection, which is also the light effect advantage of the optical waveguide when the light waveguide is applied in VR or AR. Emergent light transmitted along the-z direction through the light waveguide coupling light exit pupil can transmit the 'total reflection surface' of other light waveguides in the direction. In theconventional stack structure 10 of light guide projection unit, the coupled-out pupils of the light guides may also be partially overlapped in a staggered manner, as shown in fig. 4, wherein the reflection surfaces 1401c, 1402c and 1403c can introduce the un-coupled-out light beams in the light guides into the coupled-outdevice 1501 again through secondary reflection, thereby improving the coupling-out efficiency. Although the reflective surface may be added to improve coupling efficiency if desired, it will not be depicted in the following figures for clarity. When the coupled-out pupil is arranged in a dislocated manner, the optical waveguides of different optical waveguide projection units may be arranged in a dislocated manner as shown in fig. 4, or may be arranged in an aligned manner as shown in fig. 5. When more than one optical waveguide projection units are superposed into a stack structure, the image plane projection devices and the compensation units corresponding to the optical waveguide projection units are optimally shared. As shown in fig. 3 to 5, the imageplane projection devices 1701, 1702 and 1703 are common, and thecompensation units 1801, 1802 and 1803 are common. Fig. 6 shows a stacked structure of the projection unit with the coupled-out exit pupil of the optical waveguide in a staggered arrangement. In this case, the imageplane projection devices 1701, 1702 and 1703 may also be selectively attached to or etched in the respective corresponding exit pupils. In fact, the dislocation of adjacent optical waveguides along the-z direction is small, and the image plane projection devices of different optical waveguide projection units optimally adopt a common scheme. Similar to fig. 5, the structure shown in fig. 6 may also adopt a structure of an optical waveguide alignment type. The illustration used in the following examples may be an optical waveguide offset type structure and an optical waveguide alignment type structure, but both structures may be common and will not be described again.

Fig. 1 to 6 illustrate a common structure of a conventional opticalwaveguide projection unit 101, and different spatial positional relationships between the coupled-out pupils of the optical waveguide projection units when they are superimposed. The display system of this patent is explained based on a similar structure. As described above, the optical waveguide and the related auxiliary optical device that project the virtual image and guide the optical information to propagate only through the corresponding coupled exit pupil can replace the optical waveguide projection unit in the following embodiments, thereby realizing three-dimensional display of the optical field with a light and thin structure.

A conventional optical waveguide projection unit stack-time division multiplexing display system is shown in FIG. 7, and comprises G (≧ 1) conventional optical waveguide projection unitsThe optical waveguide projection unit is formed by stacking. Here, the conventional opticalwaveguide projection units 101 and 102 are described by way of example with G ═ 2. Some components of each optical waveguide projection unit are not shown, and their spatial relationship with the key components shown is readily understood from fig. 1 and 2 and the common general knowledge in the art. The conventional opticalwaveguide projection unit 101 projects a virtual image 1101 'to aprojection plane 1901 in the + z direction, and propagates light information of the virtual image 1101' only in the-z direction through the coupled-outlight exit pupil 1601. Also, the conventional opticalwaveguide projection unit 102 projects a virtual image 1102 'to the projection plane 1902 in the + z direction, and propagates light information of the virtual image 1102' only to the-z direction through the coupled-outlight exit pupil 1602. In fig. 7,projection planes 1901 and 1902, virtual image 1101 'and virtual image 1102' are designed to spatially overlap. The distance between adjacent apertures is smaller than the diameter D of the pupil of the observer_pThe small-pitch aperture array 60, which is composed of 2 aperture groups T, is placed in front of the coupled-outpupils 1601 and 1602 along the-z direction. Wherein the aperture A₁₁And pore diameter A₁₂Set of, pore diameter A₂₁And pore diameter A₂₂And one group, the adjacent aperture intervals T-1 in the same aperture group are 1 aperture, and T-2 groups of apertures are staggered. In the x direction, thecoupling exit pupils 1601 and 1602 are completely non-overlapping, and the offset T is 2 apertures, so that thecoupling exit pupil 1601 only covers the aperture a₁₁And A₂₁The exit light from the coupled-out pupil 1602 covers only the aperture A₁₂And A₂₂. That is, the virtual image 1101' projected by the conventional opticalwaveguide projection unit 101 can cover only the aperture a corresponding to the conventional opticalwaveguide projection unit 101₁₁And A₂₁And pore diameter A₁₂And A₂₂No intersection exists; the equivalent emergent light projected by the conventional opticalwaveguide projection unit 102 to form the virtual image 1102' can only cover the aperture A corresponding to the conventional opticalwaveguide projection unit 102₁₂And A₂₂And pore diameter A₁₁And A₂₁There is no intersection. Thediaphragm 70 is positioned at the closely spacedaperture array 60 to block out light from the conventional opticalwaveguide projection unit 101 that passes through its corresponding aperture A₁₁And A₂₁The transmitted light from the outer spatial region is blocked from passing through its corresponding aperture A from the conventional opticalwaveguide projection unit 102₁₂And A₂₂Light transmitted from the outer spatial region.

Thecontrol unit 80 is connectedA smallpitch aperture array 60 andpixel arrays 1101, 1102 corresponding to virtual images 1101 ', 1102', as in fig. 7. In each of 2 adjacent time points T and T + Δ T/2 within the time period Δ T, only one of the 2 aperture groups is opened. FIG. 8 shows aperture set A at time t₁₁And A₁₂The open state. Pore diameter A₁₁The corresponding conventional opticalwaveguide projection unit 101 projects a virtual image 1101' whose optical information can only pass through the aperture a₁₁Transmission of the content of the scene to be displayed in relation to A₁₁A view of (a); pore diameter A₁₂The corresponding conventional opticalwaveguide projection unit 102 projects a virtual image 1102' whose optical information can only pass through the aperture a₁₂Transmission of the content of the scene to be displayed in relation to A₁₂To (d) is shown. The view of the scene to be displayed with respect to an aperture may be obtained according to the method described in PCT15/481,467, where the viewpoint distribution area of the view is an area surrounded by a connecting line between a side point of the projected virtual image area and a side point of the aperture, for example, an area covered by oblique lines in fig. 9. Optimally, the viewpoints are taken to be the midpoints of the corresponding apertures, such as viewpoints VP1 and VP3 in fig. 8. FIG. 10 shows the aperture group A at time t + Δ t/2₂₁And A₂₂The open state. Pore diameter A₂₁The corresponding conventional opticalwaveguide projection unit 101 projects a virtual image 1101' set to the scene to be displayed with respect to the aperture a₂₁View of midpoint VP2, Aperture A₂₂The corresponding conventional opticalwaveguide projection unit 102 projects a virtual image 1102' set to the scene to be displayed about A₂₂View of midpoint VP 4. The process is repeated for different time periods. When the time period is sufficiently small, based on visual retention, views from two or more different viewpoints can be obtained through apertures spaced less than the pupil diameter in the-z direction with little distance from the observer's pupil at theaperture array 1701. Another view information determining method different from PCT15/481,467 is that when the virtual images projected by the conventional optical waveguide projection units are not in an overlapped state in space, for example, they are connected adjacent to each other on the projection plane, and when one aperture group is opened, the conventional optical waveguide projection units project virtual image loading information as different parts of a view whose viewpoint is the intersection of the line through which the virtual image is projected by the conventional optical waveguide projection units and the corresponding opened aperture, such as the conventional optical waveguide projection unitsThe optical waveguide projection unit projects an intersection point of a connecting line of the virtual image center point and the corresponding opening aperture center point. When connecting lines of virtual image central points projected by different conventional optical waveguide projection units and corresponding open aperture central points of the virtual image central points intersect at a plurality of points, the points in the point distribution areas can be taken as the viewpoints. According to the display principle described in PCT15/481,467, two or more views received through the pupil, whose emergent rays are spatially superimposed, form a target scene light point distribution that the corresponding eye of the pupil can naturally focus on monocular. One conventional optical waveguide projection unit stack-time divisionmultiplexing display system 10 corresponds to one eye of an observer, and two conventional optical waveguide projection unit stack-time divisionmultiplexing display systems 10 with the same structure respectively correspond to two eyes of the observer, so that a binocular three-dimensional display system can be constructed and completed, such as a head-mounted Virtual Reality (VR), a head-mounted Augmented Reality (AR) and the like. The following embodiments are discussed only with respect to monocular multiview presentations, and in the case where the monocular architecture is easily extended to a binocular display system, the case of the binocular display system will not be discussed in detail.

When the lightfield display system 10 based on the conventional optical waveguide coupled-out pupil division-combination control shown in fig. 7 achieves the above-mentioned functions, the T aperture groups corresponding to the same conventional optical waveguide projection unit in the T aperture groups may be switched, the opening timing of each aperture group may be switched, and the stacking order of the G conventional optical waveguide projection units may also be switched.

In fact, the distance L between the observer's eye and the smallpitch aperture array 60 takes into account spatial compatibility_rMust be greater than zero. The geometrical relationship shown in FIG. 11 is Δ D/Δ D ═ D/(D + L)_r). Where Δ D' is the spatial distance at the pupil of the light ray from an equivalent pixel onprojection plane 1901 that passes through the adjacent viewpoint, and D is the distance between smallpitch aperture array 60 andprojection plane 1901. The equivalent pixel is a corresponding image point of one pixel of the projection unit on the virtual image of the projection unit, and the emergent light of the pixel is equivalently regarded as the emergent light of the equivalent pixel through the light transmitted from the exit pupil to the-z direction. With L_rIncreasing, Δ d' increases. In this case, two conditions can ensure that more than one view enters the eye of the viewer. First, Δ d' is smaller than pupilDiameter D of hole_pNot only Δ D being smaller than the pupil diameter D_p(ii) a Second, the number of apertures is sufficiently large to satisfy, in the x-direction: distance between two apertures at the farthest distance/size of projected virtual image ≧ L_r/(L_r+ D). When Δ d is sufficiently small and the number of apertures is sufficiently large, a large L can be obtained_rValue when the observer's eye is not at L_rInstead, when placed closer to the small array of spacedapertures 60, a conventional optical waveguide projection unit stack-time division multiplexeddisplay system 10 may provide a field of view that covers both eyes of the viewer, allowing each eye of the viewer to receive more than one view information within the field of view. In this case, the conventional optical waveguide projection unit stack-time divisionmultiplexing display system 10 can be further applied to portable terminals such as mobile phones, computer screens, and various other display screen devices. A sufficiently small Δ d and a sufficiently large number of apertures while ensuring a reasonable display frequency would require a conventional optical waveguide projection unit stack-time division multiplexeddisplay system 10 to combine a relatively large number, and/or high display frame rate, of optical waveguide projection units. This paragraph relates to L_rThe size design requirements also apply to the display systems based on other types of light wave projection units, which will not be repeated below.

In each of the above figures, the apertures are shown as being arranged contiguously and seamlessly, i.e., the aperture clear width is equal to the aperture pitch. In fact, the aperture clear width may be larger or smaller than the aperture pitch on the premise of satisfying the function realization of each component. Implementations in which the aperture clear width is greater than the aperture pitch may be achieved by devices such as controllable liquid crystal aperture arrays.

When T and G are taken to be 1, respectively, the optical structures of the conventional optical waveguide projection unit stack-time divisionmultiplexing display system 10 are shown in fig. 12 and 13, respectively. However, T × G ≧ 2 is required to ensure the presentation of at least two views of a pupil, so T and G cannot simultaneously take 1.

The conventional optical waveguide projection unit may also be a superposition of optical waveguide projection units that respectively project only monochromatic virtual images, such as the frequency division multiplexing conventional opticalwaveguide projection unit 201 shown in fig. 14. The frequency division multiplexing conventional opticalwaveguide projection unit 201 is formed by stacking three single-color (e.g., commonly used R, G, B) opticalwaveguide projection units 101, 102, and 103. The three monochromatic conventional opticalwaveguide projection units 101, 102 and 103 project virtual image equivalent emergent light which is red light, green light and blue light respectively, the virtual image equivalent emergent light is synthesized to generate a color virtual image effect, the coupled light exit pupils of the three monochromatic conventional optical waveguide projection units are overlapped, and an image plane projection device is shared.

Another polarization optical waveguide projection unit stack-time division multiplexing display system for realizing monocular multi-view light field display is shown in fig. 15, and is formed by stacking G (≧ 1) polarization optical waveguide projection units. Here, the explanation will be given taking the example of the polarization characteristic opticalwaveguide projection units 301 and 302 with G ═ 2. The polarization characteristic opticalwaveguide projection unit 301 projects a virtual image 1101 'to theprojection plane 1901 in the + z direction, and propagates light information of the virtual image 1101' only in the-z direction through the coupled-outlight exit pupil 1601. Also, the conventional opticalwaveguide projection unit 302 projects a virtual image 1102 'to the projection plane 1902 in the + z direction, and propagates light information of the virtual image 1102' only to the-z direction through the coupled-outlight exit pupil 1602. In fig. 15,projection surfaces 1901 and 1902, virtual image 1101 'and virtual image 1102' are designed to overlap spatially, and the polarization characteristic optical waveguide projection units share theimage projection device 1701 and thecompensation unit 1801. For a clearer and simpler illustration, theimage projection device 1701 and thecompensation unit 1801 are not shown in fig. 15. The virtual image 1101' is composed of 4 sub-regions, i.e., S (≧ 1) ═ 4, and is a sub-region 1(301), a sub-region 2(301), a sub-region 3(301), and a region 4(301), respectively, in the x direction. Virtual image 1102' is composed of the same 4 sub-regions in the x-direction, which are sub-region 1(302), sub-region 2(302), sub-region 3(302), and region 4 (302). When they are fully coincident, they are represented directly byregion 1,subregion 2, subregion 3 and region 4. The requirement of the polarization characteristic of equivalent emergent light information on each subarea is as follows: equivalent emergent light polarization states of virtual images projected by the same polarization characteristic optical waveguide projection units on adjacent sub-areas are mutually orthogonal, and equivalent emergent light polarization states of the virtual images projected by the adjacent polarization characteristic optical waveguide projection units on the sub-areas with the same sequence number along x direction are mutually orthogonal. Under the condition that the virtual images projected by the polarization characteristic optical waveguide projection units are overlapped, the latter requirement is that the polarization states of equivalent emergent light projected by the virtual images projected by the adjacent polarization characteristic optical waveguide projection units on the same sub-area are mutually orthogonal. In FIG. 15, 1 is set on four subregions along the x direction101 'equivalent emergent light polarization state distribution is "" and 1102' equivalent emergent light polarization state distribution is "" and "" respectively. The distance between adjacent apertures is smaller than the diameter D of the pupil of the observer_pIs placed in front of the coupling-outpupils 1601 and 1602 in the-z direction, and consists of 2 aperture groups, T. Wherein the aperture A₁₁、A₁₂、A₁₃、A₁₄And A₁₅Form an aperture group with an aperture A₂₁、A₂₂、A₂₃、A₂₄And A₂₅Constitute another aperture group. The apertures of 2 aperture groups are staggered, and the interval T-1 between adjacent apertures in the same aperture group is 1 aperture. Each aperture of the 2 aperture groups, along the x direction, allows the polarization direction of the transmitted light to be sequentially designed as "-". In the x-direction, the partially overlapping coupled-outpupils 1601 and 1602, the offset T being 2 apertures. In the first aperture group, the adjacent apertures A constituting one aperture subgroup₁₁、A₁₂、A₁₃And A₁₄Corresponding to 1101'sub-region 1,sub-region 2, sub-region 3 and sub-region 4 in sequence; adjacent A forming another aperture subgroup₁₂、A₁₃、A₁₄And A₁₅Corresponding tosub-region 1,sub-region 2, sub-region 3 and sub-region 4 of 1102' respectively in sequence; in the second aperture group, adjacent A constituting one aperture subgroup₂₁、A₂₂、A₂₃And A₂₄Sub-region 1,sub-region 2, sub-region 3 and sub-region 4, which in turn correspond to 1101', respectively, constitute the neighbor a of another aperture subgroup₂₂、A₂₃、A₂₄And A₂₅Which in turn correspond tosub-region 1,sub-region 2, sub-region 3, and sub-region 4, respectively, of 1102'. Each aperture, and its corresponding sub-region, has the same polarization characteristics. One aperture, possibly corresponding to only one sub-region, such as aperture A₁₁Corresponding only tosub-region 1 of 1101', and possibly to different sub-regions of the virtual image projected by the optical waveguide projection unit of different polarization characteristics, such as aperture a₁₂Corresponding tosub-regions 2 and 1102 'of 1101'. Thediaphragm 70 is disposed at the smallpitch aperture array 60, and blocks transmission light from a spatial region other than the aperture of each polarization characteristic optical waveguide projection unit.

Thecontrol unit 80 connects the small-pitch aperture array 60 and thepixel arrays 1101, 1102 corresponding to the virtual images 1101 ', 1102'. For clarity and simplicity of illustration, neither thecontrol unit 80 nor thepixel arrays 1101 and 1102 are shown in the figure. At 2 adjacent time points T and T + Δ T/2 within the time period Δ T, thecontrol unit 80 opens only one aperture group, respectively. FIG. 16 shows time t, aperture set A only₁₁、A₁₂、A₁₃、A₁₄And A₁₅And (4) opening. Virtual image 1101'subregion 1 to aperture A₁₁A view is projected about the aperture, again with virtual images 1101'sub-regions 2, 3, 4, respectively, directed towards the aperture a₁₂、A₁₃、A₁₄Projecting a view about the aperture, virtual image 1102'subregions 1, 2, 3, 4 are directed towards the aperture a, respectively₁₂、A₁₃、A₁₄、A₁₅A view is projected about the aperture. The view of a sub-area with respect to an aperture refers to the distribution information of the view of the scene to be displayed with respect to the aperture over the sub-area. The view point region of this view, similarly designed to the principle shown in fig. 9, is optimally chosen to correspond to the midpoint of the aperture. The difference is that the edge points on theprojection plane 1901 take the edge points of the sub-regions and are no longer the edge points of the entire projected virtual image. The view loading can also adopt another loading mode: and synchronously projecting the view of the scene to be displayed relative to the corresponding open aperture subgroup of the polarization characteristic optical waveguide projection unit by each polarization characteristic optical waveguide projection unit. The viewpoint of the scene projected by one polarization characteristic optical waveguide projection unit with respect to the view corresponding to the opened aperture subgroup is the intersection point of the different sub-regions of the virtual image projected by the polarization characteristic optical waveguide projection unit and the straight lines of the sub-regions corresponding to the apertures in the aperture subgroup. In the case where the sub-regions and the aperture arrays are arranged at equal intervals, the viewpoint is most preferably an intersection of the centers of the sub-regions of the virtual image projected by the polarization characteristic optical waveguide projection unit and the central lines of the apertures in the corresponding aperture sub-group, as viewed from viewpoints VP1 and VP3 in fig. 16. At the time of t + delta t/2, the aperture group A is closed₁₁、A₁₂、A₁₃、A₁₄And A₁₅Opening the aperture group A₂₁、A₂₂、A₂₃、A₂₄And A₂₅. The corresponding views are loaded similarly, forming viewpoints VP2 and VP4, as shown in fig. 17. The process is repeated for different time periods. When the time period is sufficiently small, G × T ═ 4 viewpoints are generated based on the visual retention. Due to the introduction of S sub-regions, the viewing area covered by each viewpoint of the polarization characteristic optical waveguide projection unit stack-time divisionmultiplexing display system 20 is effectively improved, or the distance between the viewpoint and the smallpitch aperture array 60 is increased, compared to the conventional optical waveguide projection unit stack-time divisionmultiplexing display system 10 shown in fig. 8.

When the lightfield display system 20 with polarization characteristic optical waveguide coupling exit pupil division-combination control shown in fig. 15 realizes the above functions, the attribution of T apertures corresponding to the same sub-region of the polarization characteristic optical waveguide projection unit in the T groups of apertures can be changed. Further, after the one-to-one correspondence relationship between each sub-region of each polarization characteristic optical waveguide projection unit and each aperture is determined, the operation order of each time point in one cycle may be changed, and the stacking order of the G polarization characteristic optical waveguide projection units may be changed.

The polarization characteristic opticalwaveguide projection unit 301 may adopt the structure of the basic opticalwaveguide projection unit 101 shown in fig. 1 and fig. 2, and even other optical waveguide projection units that can project a virtual image 1101' to aprojection plane 1901 at a limited distance from-z through the coupled-outlight exit pupil 1601, but thepixel array 1101 requiring the outgoing light is divided into S regions according to the object image correspondence, and the polarization characteristic of the outgoing light from each region is consistent with the polarization direction of the equivalent outgoing light corresponding to the sub-viewing zone on theprojection plane 1901. Meanwhile, the optical device in which the optical transmission process and light interact has polarization maintaining characteristics. Such astotal reflection surfaces 1401a and 1401b which do not change the polarization direction of incident light, and anoptical coupler 1501 which has the same polarization state of outgoing light and polarization state of incident light.

The combination of the optical waveguide and the related devices which can realize that equivalent emergent light in different areas of the projected virtual image has different polarization states can be obtained by other modes and can also be used as the optical waveguide projection unit with the polarization characteristics. For example, a complex-structured polarization characteristic opticalwaveguide projection unit 401 as shown in fig. 18. The complex-structured polarization characteristic opticalwaveguide projection unit 401 is formed by stacking M + N-1-2 conventional opticalwaveguide projection units 101 and 102. The conventional opticalwaveguide projection unit 101 has 2 exit pupils spaced apart from each other, andpolarizers 90a and 90b, which are attached to the exit pupils and have the same size as the corresponding exit pupils, allow the light to pass through in the polarization state "·"; the conventional opticalwaveguide projection unit 102 couples out an exit pupil having 2 exit pupils spaced apart from each other, andpolarizers 90c and 90d, which are attached to the exit pupils and have the same size as the corresponding exit pupils, allow the passage of the polarized light state "-". They are designed in the order of 90c, 90a, 90d, 90b in the x-direction. Wherein 90c corresponds tosubregion 1 of 1102 ', 90a corresponds tosubregion 2 of 1101', 90d corresponds to subregion 3 of 1102 ', and 90b corresponds to subregion 4 of 1101'. Thesubregions 2 of thesubregions 1 and 1101 'of the 1102' and the subregions 3 of the 1102 'and 4 of the 1101' are respectively used as thesubregions 1, 2, 3 and 4 of the complex-structure polarization characteristic opticalwaveguide projection unit 401, and the polarization state of equivalent outgoing light is "-, in order along the x direction. Other sub-regions of the conventional optical waveguide projection unit, includingsub-region 1 of 1101 ',sub-region 2 of 1102', sub-region 3 of 1101 ', and sub-region 4 of 1102', whose corresponding pixels on the pixel array are no longer loaded with information, or are not present directly. An "x" in the figure represents that the sub-region is not loaded with view information, or that its corresponding pixel is not present on thepixel array 1101. In the complex-structured polarization characteristic opticalwaveguide projection unit 401, the stacked conventional optical waveguide projection units optimally share one imageplane projection device 1701 and onecompensation unit 1801. In fig. 18, the polarizer corresponding to each exit pupil is attached to the exit pupil. In fact, the polarizer corresponding to each pupil may be attached to the foremost optical waveguide surface, i.e., theoptical waveguide surface 1401b shown in fig. 18, in the light beam propagation direction. Even the polarizer corresponding to each exit pupil may be replaced by a polarizer withsmall pitch apertures 60 for each aperture. Only when T aperture groups are employed, each exit pupil of the here complex-structured polarization characteristic optical waveguide projection unit needs to be assigned to adjacent T apertures of theaperture array 60.

The time-series optical waveguide projection unit stack-time divisionmultiplexing display system 30 is, as shown in fig. 19, configured to project G (≧ 1) time-series optical waveguidesThe units are stacked. Here, the timing characteristic opticalwaveguide projection units 501 and 502 are explained as an example where G is 2. The time-series characteristic opticalwaveguide projection unit 501 projects a virtual image 1101 'to aprojection plane 1901 in the + z direction, and propagates light information of the virtual image 1101' only in the-z direction through the coupled-outlight exit pupil 1601. Similarly, the timing opticalwaveguide projection unit 502 projects a virtual image 1102 'to the projection plane 1902 in the + z direction, and propagates light information of the virtual image 1102' only to the-z direction through the coupled-outlight exit pupil 1602. In fig. 19,projection planes 1901 and 1902, virtual image 1101 'and virtual image 1102' are designed to spatially overlap. Theimage projection device 1701 and thecompensation unit 1801 are shared by the timing characteristic optical waveguide projection units. For a clearer and simpler illustration, theimage projection device 1701 and thecompensation unit 1801 are not shown in fig. 19. Virtual images 1101 'and 1102' are formed along the x direction by 4 sub-regions,sub-region 1,sub-region 2, sub-region 3, and region 4. The distance between adjacent apertures is smaller than the diameter D of the pupil of the observer_pThe small-pitch aperture array 60 is disposed in front of the coupled-outlight pupils 1601 and 1602, and is composed of 2 groups of apertures. The coupled-out pupils of 2 adjacent time sequence characteristic optical waveguide projection units are sequentially arranged in an X direction in a staggered way by T-2 apertures. Pore diameter A₁₁、A₁₂、A₁₃、A₁₄And A₁₅Form an aperture group with an aperture A₂₁、A₂₂、A₂₃、A₂₄And A₂₅Constitute another aperture group. In the arrangement of all the apertures, the interval T-1 between adjacent apertures in the same aperture group is 1 aperture, and the apertures in T-2 aperture groups are staggered. In the first aperture group, A constituting an aperture subgroup₁₁、A₁₂、A₁₃And A₁₄Sequentially corresponding tosub-region 1,sub-region 2, sub-region 3 and sub-region 4 of 1101' respectively to form an aperture subgroup A₁₂、A₁₃、A₁₄And A₁₅Corresponding tosub-region 1,sub-region 2, sub-region 3 and sub-region 4 of 1102' respectively in sequence; in the second aperture group, A constituting one aperture subgroup₂₁、A₂₂、A₂₃And A₂₄Sequentially corresponding tosub-region 1,sub-region 2, sub-region 3 and sub-region 4 of 1101' respectively to form an aperture subgroup A₂₂、A₂₃、A₂₄And A₂₅Which in turn correspond tosub-region 1,sub-region 2, sub-region 3, and sub-region 4, respectively, of 1102'. An aperture, possibly corresponding to only one sub-region, such as A₁₁Corresponding tosubregion 1 of 1101'. An aperture may also correspond to different sub-areas of the projected virtual image from different timing characteristics of the optical waveguide projection unit, e.g. A₁₂Corresponding tosub-regions 2 and 1102 'of 1101'. Thestop 70 is disposed at the smallpitch aperture array 60, and blocks transmission light from a spatial region other than the aperture from each timing characteristic optical waveguide projection unit. In each aperture group, apertures sequentially spaced by V-1 apertures form an aperture cluster. Where the value of V is the number of clusters for each pore size component as a pore size cluster. Then a total of 4 aperture clusters, where a₁₁、A₁₃、A₁₅Make upcluster 1, A₂₁、A₂₃、A₂₅Make upcluster 2, A₁₂、A₁₄Make up cluster 3, A₂₂、A₂₄Forming clusters 4. And at 4 time points, sequentially opening only one cluster of apertures, and controlling to open only the sub-regions corresponding to the apertures to load the corresponding views. As in FIG. 19, the aperture ofcluster 1 is open, its A₁₁Sub-region 1 loading corresponding to 1101' relative to A₁₁View information of A₁₃Sub-regions 2 corresponding to sub-regions 3 and 1102 'of 1101' are loaded relative to aperture a, respectively₁₃View information of (A)₁₅The sub-region 4 corresponding to 1102' is loaded relative to the aperture a₁₅View information of (2). Fig. 20 shows the case when the aperture of cluster 3 is open. An "x" in the figure represents that the view information is not loaded by the sub-region. Then, after only one cluster of apertures is opened and corresponding information is loaded in sequence at the time points of txv ═ 4, presentation of txv ═ 4 viewpoints can be achieved, such as the formation viewpoints VP1, VP2, VP3, and VP4 in fig. 20.

The determination of each sub-region with respect to a certain aperture view information is designed similarly to the principle shown in fig. 9, and the midpoint of the corresponding aperture is preferably taken. The difference is that the edge points on theprojection plane 1901 take the edge points of the sub-regions and are no longer the edge points of the entire projected virtual image. The determination of each sub-region with respect to a certain aperture view information may also adopt another way: the time sequence characteristic optical waveguide projection unit of the sub-area projects information of a virtual image area on the sub-area relative to the view of the aperture sub-group of the aperture. The viewpoint of the virtual image region projected by the time-series characteristic opticalwaveguide projection unit 501 with respect to a certain aperture sub-group view is an intersection of a different sub-region of the virtual image projected by the time-series characteristic opticalwaveguide projection unit 501 and a line of the corresponding aperture of the sub-region in the aperture sub-group. In the case where the sub-regions and the aperture array are arranged at equal intervals, the viewpoint is optimally the intersection point of the centers of the sub-regions of the virtual image projected by the time-series characteristic opticalwaveguide projection unit 501 and the connecting line of the centers of the corresponding apertures in the aperture sub-group, as shown in fig. 19 and 20.

The timing characteristic opticalwaveguide projection unit 501 may adopt the structure of the basic opticalwaveguide projection unit 101 shown in fig. 1 and fig. 2, and even other optical waveguide projection units that can project a virtual image 1102' to theprojection plane 1901 at a limited distance in the-z direction through the coupled-out pupil 1601 thereof, but thepixel array 1101 is required to reach a higher frame frequency to realize flicker-free display. In addition, the stacked time-series characteristic optical waveguide projection units optimally share the image plane projection device or/and the compensation unit. The attribution of the T apertures corresponding to the same sub-region of the time sequence characteristic optical waveguide projection unit in the T groups of apertures can be exchanged. Further, after the one-to-one correspondence relationship between each sub-region of each timing characteristic optical waveguide projection unit and each aperture is determined, the working order of each time point in one cycle may be changed, and the stacking order of G timing characteristic optical waveguide projection units may be changed.

In fig. 15 to 17, sub-regions having the same polarization state exist in the sub-regions corresponding to the polarization characteristic opticalwaveguide projection unit 301. When the corresponding aperture sub-group is opened at a time point, equivalent emergent light of one sub-region can be used as noise to pass through other sub-regions with the same polarization state to correspondingly open apertures. Especially, when the aperture is opened correspondingly by the sub-regions of the same type (the same equivalent emergent light polarization state) which are closest, the generated noise distribution region is closest to the view point of the display view, as shown in fig. 16, and easily enters the pupil of the observer to influence the display effect. The aperture subgroup opened at the same time point is expanded to be opened step by step at more time points to allow adjacent apertures of the same type (the allowed light-transmitting polarization states are the same)And opening at different time points, and simultaneously, not loading information on the sub-regions corresponding to the unopened apertures, so that the noise can be suppressed. The optical waveguide projection unit at this time is named as a polarization time sequence opticalwaveguide projection unit 601, and G polarization time sequence optical waveguide projection units construct a polarization-time sequence optical waveguide projectionunit stack structure 40 which can realize the presentation of a small-distance viewpoint view in the same manner. For clarity and simplicity of illustration, fig. 21 illustrates the polarization-time waveguide projectionunit stack structure 40 with G ═ 1 as an example. The polarization time sequence opticalwaveguide projection unit 601 adopts the optical structure of the polarization characteristic optical waveguide projection unit, and the difference is that the same optical waveguide projection unit in the polarization time sequence opticalwaveguide projection unit 601 projects different virtual image sub-regions to load time sequence information at different time points. As a specific example, as shown in fig. 21, a polarization-time sequential opticalwaveguide projection unit 601 is constructed by sequentially loading information at two points in time into 4 regions of apixel array 1101 in a polarization-characteristic opticalwaveguide projection unit 301. In the figure, A₁、A₃、A₅And A₇Is a group of apertures, A₂、A₄、A₆And A₈Is an aperture group. 4 points in time of one cycle, A in the case of the indicated smaller number of apertures₁And A₃The formed mixed aperture is independently a cluster, is opened at the time t, and thearea 1 and thearea 2 which respectively correspond to 1101' are correspondingly loaded with information, and the information is determined by adopting the viewpoint determining method adopted by the opticalfield display system 20 of the polarization characteristic optical waveguide coupling exit pupil division-combination control. A. the₅And A₇Is a cluster, is turned on at time t + Δ t/2, and the corresponding areas 3 and 4 at 1101' are loaded with information. In the same way, A₂And A₄Is a cluster, is opened at time t + Deltat/4, and is loaded with information corresponding toregion 1 andregion 2, respectively, at 1101₆And A₈The image is a cluster, the image is opened at the time t +3 delta t/4, the corresponding area 3 and the corresponding area 4 on 1101' are correspondingly loaded with information, and two view point presentations for reducing noise are realized based on visual retention. More points in time within a cycle may be better at reducing the above noise when more apertures are designed.

When the multi-structure polarization characteristic opticalwaveguide projection unit 401 shown in fig. 18 is used, if more optical waveguide projection units are stacked, the sub-regions of the multi-structure polarization characteristic opticalwaveguide projection unit 401 from the same conventional optical waveguide projection unit are spaced apart from each other at a larger interval, and the above-described noise can be reduced. Even when a conventional optical waveguide projection unit contributes only one sub-region to the complex-structured polarization characteristic opticalwaveguide projection unit 401, the above noise is completely suppressed.

In fig. 15 to 17 and 19 to 21, the image displayed on the projection surface is a virtual image of the pixel array transmitted through the optical waveguide. If the display image generated by other means, such as an image displayed by a real display screen, or an image projection plane generated by reflecting an external projection image by a reflecting screen, or an image generated by diffracting an external projection image by a diffraction screen, or a virtual image generated by a small display (pixel array) in a conventional head-mounted VR/AR through an imaging lens, is equivalent to the virtual image generated by transmission through an optical waveguide in the patent. The small-pitch aperture arrays of polarization characteristics and their associated applications discussed with reference to fig. 15-17, the small-pitch aperture arrays of timing characteristics and their associated applications discussed with reference to fig. 19-20, and the small-pitch aperture arrays of polarization timing and their associated applications discussed with reference to fig. 21 are all suitable for use in displaying images on a display surface in other ways. In each of the configurations of the display system described in the prior patent PCT15/481,467, the three-dimensional light field display can be performed by using the small pitch aperture array having the polarization characteristic and/or the time-series characteristic and by controlling the polarization state or time-series region of the projected image.

In the above embodiment, the virtual images projected by the different optical waveguide projection units in the display system are arranged to be completely coincident. In practice, the above implementation may be performed in synchronization when the virtual images originating from different optical waveguide projection units are misaligned, including misalignment in the depth (z direction) caused by the respective optical waveguide projection units using differentimage projecting devices 1701, and x-direction misalignment caused by the optical structure itself.

The core idea of the patent is to realize the projection of the small-interval viewpoint views to each purpose of an observer through the split-combination control of the coupled light exit pupil of the plurality of optical waveguide projection units. Other various optical waveguide projection structures, such as PCT/2013/045267, implement optical waveguide projection units for displaying different projection images on different depth display surfaces, such as optical waveguide projection units designed with other various light incoupling devices and other various relay devices, optical waveguide projection units fused with other pupil-expanding optical components, or optical waveguide projection units designed with optical components that split images during coupling and restore images during coupling, and optical waveguide components that can propagate information projected onto a limited distance view through an coupled-out pupil can be used as the conventional opticalwaveguide projection unit 101, or the polarization characteristic opticalwaveguide projection unit 301, or the timing opticalwaveguide projection unit 501, and perform optical field display based on "coupled-out pupil splitting-combining control" in combination with the small-pitch aperture array described in this patent. The system of the present invention may be further extended, for example, by designing differentimage projection devices 1701, a plurality of projection surfaces may be formed at different depths, and then, on the projection surface at each depth, the light field display based on the "coupled-out pupil segmentation-combination control" described in the present invention may be performed, so as to improve the depth of field of the displayed light field scene. The system adopts the polarization characteristic and the time sequence characteristic commonly used by optics to build a system, and the polarization characteristic and the time sequence characteristic are all in an orthogonal state. The polarization characteristics may be two sets of perpendicular linear polarizations, which are also used in the above embodiments, or left-handed and right-handed polarizations. In fact, whatever other possible orthogonal states may be used for light field display system construction, as long as they can be mutually identified through an aperture, that is, only one corresponding orthogonal state can pass through one aperture, and the other orthogonal states can be further utilized as the polarization orthogonality or the time sequence orthogonality in the embodiments of the present patent document.

The above is only a preferred embodiment of the present invention, but the design concept of the present invention is not limited thereto, and any insubstantial modifications made by using the design concept fall within the scope of the present invention. For example, the exclusive use of this feature is not limiting. Accordingly, all such related embodiments are intended to be within the scope of the following claims.

Claims (30)

1. A light field display system based on conventional optical waveguide coupled-out pupil division-combination control, comprising:

the conventional optical waveguide projection unit stack structure is formed by stacking G conventional optical waveguide projection units, each conventional optical waveguide projection unit projects a virtual image to the + z direction, and projects virtual image light information to the-z direction only through a coupling light exit pupil of each conventional optical waveguide projection unit, wherein G is not less than 1;

the small-interval aperture array is composed of T groups of apertures capable of being switched in a time sequence, each aperture group comprises G apertures sequentially spaced by T-1 apertures, the aperture groups are arranged in front of each coupled exit pupil in the-z direction, of the G multiplied by T apertures, and the interval between adjacent apertures is smaller than the diameter D of the pupil of an observer_pThe T aperture groups are staggered one by one along the x direction, wherein T is not less than 1, and T multiplied by G is not less than 2;

in the stack structure of the conventional optical waveguide projection units, coupled light exit pupils of adjacent conventional optical waveguide projection units are sequentially staggered in the x direction and are arranged without overlapping with T apertures, each conventional optical waveguide projection unit respectively corresponds to T apertures from different aperture groups, which are arranged adjacently, and the conventional optical waveguide projection units emit light rays through the coupled light exit pupils to cover the T apertures corresponding to the conventional optical waveguide projection units and have no intersection with the apertures corresponding to other conventional optical waveguide projection units;

the control unit is used for controlling the T aperture groups to be opened in sequence only by one group at each T adjacent time points and controlling each conventional optical waveguide projection unit to synchronously project a view of a scene to be displayed relative to the corresponding opened aperture of the conventional optical waveguide projection unit;

and the diaphragm is arranged at the small-spacing aperture array and used for blocking the part of emergent light from each conventional optical waveguide projection unit, which is transmitted in the area except the corresponding aperture of the conventional optical waveguide projection unit.

2. The light field display system according to claim 1, wherein when the small-pitch aperture array is arranged at an equal x-direction distance Δ D, the coupling-out pupils of the adjacent conventional light waveguide projection units have an x-direction distance Δ D ≦ txΔ D, and the width Δ W of the coupling-out pupil of each conventional light waveguide projection unit has an x-direction width Δ W ≦ txΔ D.

3. The light field display system based on conventional optical waveguide coupled-exit pupil division-combination control as claimed in claim 1, wherein when each conventional optical waveguide projection unit projects a virtual image to be adjacently connected on the projection surface, at a point in time when only one aperture group is open, each conventional optical waveguide projection unit projects virtual image loading information as a corresponding portion of one view on the projected virtual image region, the viewpoint of the view being an intersection point of a straight line which passes through each conventional optical waveguide projection unit to project the virtual image and its corresponding open aperture.

4. The light-field display system based on conventional optical waveguide coupled-out pupil division-combination control of claim 1, wherein the T apertures corresponding to the same conventional optical waveguide projection unit are switchable in their grouping, the timing of the opening of the T aperture groups is switchable, and the stacking order of the G conventional optical waveguide projection units is switchable.

5. The light field display system based on the conventional light guide coupled-exit pupil division-combination control as claimed in any one of claims 1 to 4, wherein the conventional light guide projection unit comprises: the pixel array loads optical information required by the conventional optical waveguide projection unit synchronously and emits light beams; an optical waveguide composed of a base and a total reflection surface for transmitting an incident beam by total reflection; an optical incoupling device that incouples incident light into the optical waveguide; the relay device is arranged between the pixel array and the light coupling-in device, phase-modulates each pixel of the pixel array to emit light beams, and draws the modulated light beams into the light coupling-in device; an exit pupil coupled out, an exit aperture through which the light is transmitted by the light guide; the optical out-coupling device modulates and guides the light transmitted by the optical waveguide through total reflection to be diverted to the out-coupling pupil; the image plane projection device is used for extending and converging light beams which are guided by the light coupling-out device and come from different pixels of the pixel array on each corresponding equivalent pixel on the projection plane along the + z direction in a reverse direction to form a virtual image of the pixel array on the projection plane, and the light beams which are emitted from the coupled light exit pupil are equivalent to the equivalent emergent light beams of the virtual image; and the compensation unit is arranged behind the optical coupler-out device along the-z direction and used for reversely eliminating the influence of the optical coupler-out device and the image plane projection device on the incident light of the external environment.

6. The light field display system based on the conventional optical waveguide coupled-out pupil division-combination control as claimed in claim 5, wherein the stacked conventional optical waveguide projection units share an image plane projection device or/and a compensation unit.

7. The system of claim 5, wherein the pixel array is an OLED micro-display, an LED micro-display, an LCOS micro-display, or a reflective surface for reflecting external projection information, the optical waveguide is a planar optical waveguide, the optical coupling-in device is a micro-structure grating etched on the surface of the optical waveguide by a micro-machining process, or a holographic grating exposed in the optical waveguide, or a mirror coated on the surface of the optical waveguide, or a diffraction grating attached on the surface of the optical waveguide, the relay device is a collimating lens, or an imaging lens, or/and a beam deflector, the optical coupling-out device is an embossed optical element etched on the surface of the optical waveguide, or a reflective surface array processed in the substrate of the optical waveguide, or a holographic grating exposed on the substrate of the optical waveguide, the image plane projection device is a concave lens or a holographic grating exposed on the exit pupil plane of the optical waveguide, the compensation unit is a phase film or a relief element, and the compensation unit is attached to the surface of the optical waveguide, or etched on the surface of the optical waveguide, or exposed on the surface of the optical waveguide.

8. The system according to claim 5, wherein the conventional optical waveguide projection unit is a frequency division multiplexing conventional optical waveguide projection unit formed by stacking three single-color conventional optical waveguide projection units, the three single-color conventional optical waveguide projection units project light with different wavelengths, the coupled light exit pupils of the three single-color conventional optical waveguide projection units overlap, and the projected light is combined into a color virtual image by sharing an image plane projection device or/and a compensation unit.

9. The light field display system based on the light-polarization characteristic light waveguide coupling light exit pupil segmentation-combination control is characterized by comprising the following components:

the polarization characteristic optical waveguide projection unit stack structure is formed by stacking G polarization characteristic optical waveguide projection units, each polarization characteristic optical waveguide projection unit projects a virtual image to the + z direction, and projects virtual image light information to the-z direction only through the coupled light exit pupil, wherein G is not less than 1;

in the stack structure of the polarized light characteristic optical waveguide projection units, each polarized light characteristic optical waveguide projection unit projects a virtual image and consists of S sub-regions along the x direction, equivalent emergent light polarization states of the same polarized light characteristic optical waveguide projection unit on adjacent sub-regions project the virtual image are mutually orthogonal, equivalent emergent light polarization states of adjacent polarized light characteristic optical waveguide projection units on sub-regions with the same sequence number along the x direction project the virtual image and are mutually orthogonal, wherein S is larger than or equal to 1;

small-spacing aperture array with T x (S + G-1) adjacent spacing along x direction smaller than pupil diameter D of observer_pThe aperture composition is arranged in front of each coupling light exit pupil along the-z direction, S + G-1 apertures with T-1 apertures are arranged in groups respectively, the T aperture groups in the group are staggered along the x direction by one aperture, the polarization states of passing light are orthogonal when adjacent apertures in each aperture group are opened, and the S apertures adjacent to each other in each aperture group are grouped secondarily respectively to construct and form G aperture subgroups, wherein T is not less than 1, and T multiplied by G is not less than 2;

in the polarization characteristic optical waveguide projection unit stack structure, coupling exit pupils of adjacent polarization characteristic optical waveguide projection units are sequentially staggered with T apertures along the x direction, G polarization characteristic optical waveguide projection units with the coupling exit pupils sequentially staggered correspond to G aperture sub-groups in each aperture group, the G aperture sub-groups are sequentially staggered in the same direction, S apertures of each aperture sub-group correspond to S sub-regions of a virtual image projected by the corresponding polarization characteristic optical waveguide projection units in the same direction one by one, and the polarization direction of emergent light is allowed to be consistent with the polarization direction of emergent light equivalent to the corresponding sub-regions when each aperture is opened;

the control unit is used for controlling only one group of the T aperture groups to be opened at each T adjacent time points and controlling each polarized light characteristic optical waveguide projection unit to synchronously project a view of a scene to be displayed relative to the corresponding opened aperture subgroup of the polarized light characteristic optical waveguide projection unit;

the view point of the projection unit is the intersection point of straight lines respectively passing through each sub-area of the projection unit of the polarized light characteristic optical waveguide and the corresponding aperture of the sub-area in the opening aperture subgroup;

and a diaphragm attached to the small pitch aperture array and blocking a portion of the light emitted from each polarization characteristic optical waveguide projection unit, which is transmitted through a region other than the aperture corresponding to the polarization characteristic optical waveguide projection unit.

10. The light field display system based on polarization characteristic optical waveguide coupled-exit pupil division-combination control of claim 9, wherein the sub-regions where each polarization characteristic optical waveguide projection unit projects the virtual image overlap, and the equivalent exit light polarization states of the adjacent polarization characteristic optical waveguide projection units projecting the virtual image on the same overlapping sub-region are orthogonal to each other.

11. The light field display system according to claim 9, wherein the sub-regions are arranged at equal intervals and the apertures are arranged at equal intervals Δ D, the coupling-out pupils of the adjacent light guide projection units are spaced at an x-direction distance Δ D ≦ T × Δ D, and the coupling-out pupil of each light guide projection unit is spaced at an x-direction width Δ W ≦ T × S × Δ D.

12. The light field display system based on polarization characteristic optical waveguide coupled-exit pupil segmentation-combination control of claim 11, wherein the polarization characteristic optical waveguide projection unit projects a view of the scene to be displayed with respect to the corresponding open aperture sub-group from a viewpoint of an intersection point of a center of each sub-region of the polarization characteristic optical waveguide projection unit and a line connecting the sub-region with the center of the corresponding aperture in the open aperture sub-group.

13. The light field display system based on polarization characteristic optical waveguide coupled exit pupil division-combination control of any one of claims 9 to 12, wherein the assignment of T apertures in the T groups of apertures in the same sub-region of the polarization characteristic optical waveguide projection unit is switchable.

14. The light-field display system based on splitting-combining control of the coupled exit pupil of the polarization characteristic optical waveguide according to any one of claims 9 to 12, wherein the states at each time point in a period are switchable, and the stacking order of the G polarization characteristic optical waveguide projection units is switchable.

15. The light field display system based on polarization characteristic optical waveguide coupled exit pupil division-combination control according to any one of claims 9 to 12, wherein the polarization characteristic optical waveguide projection unit comprises: the pixel array consists of S areas, and the emergent light polarization state of each area is consistent with the equivalent emergent light polarization state of a corresponding sub area on the virtual image projected by the light guide projection unit with the polarization characteristic; the optical waveguide consists of a substrate and a total reflection surface and transmits incident beams through total reflection keeping the polarization state of the incident beams unchanged; an optical incoupling device for incoupling the polarized light of the incident light into the optical waveguide; the relay device is arranged between the pixel array and the light coupling-in device, phase-modulates outgoing light beams of each pixel of the pixel array while keeping a polarization state unchanged, and draws the modulated light beams into the light coupling-in device; an outcoupled light exit pupil, the optical waveguide transmitting a light exit aperture; the optical coupler is used for modulating and guiding the polarized state of the light beam transmitted by the optical waveguide through total reflection to be invariably turned to the coupled light exit pupil; the image plane projection device is used for extending and converging light beams which are guided by the light coupling-out device and come from different pixels of the pixel array on each corresponding equivalent pixel on the projection plane along the + z direction in a reverse direction to form a virtual image of the pixel array on the projection plane, and the light beams which are emitted from the coupled light exit pupil are equivalent to the equivalent emergent light beams of the virtual image; and the compensation unit is arranged behind the optical coupler-out device along the-z direction and used for reversely eliminating the influence of the optical coupler-out device and the image plane projection device on the incident light of the external environment.

16. The light field display system based on polarization characteristic optical waveguide coupled-out pupil division-combination control of claim 15, wherein the stacked polarization characteristic optical waveguide projection units share an image plane projection device or/and a compensation unit.

17. The light field display system based on polarization characteristic optical waveguide coupled exit pupil division-combination control of any one of claims 9 to 12, wherein the polarization characteristic optical waveguide projection unit is a complex structure polarization characteristic optical waveguide projection unit formed by stacking M + N conventional optical waveguide projection units, the coupled exit pupil of each conventional optical waveguide projection unit is one or more than one exit pupil distributed at intervals, wherein the M conventional optical waveguide projection units are combined into an exit pupil array, each exit pupil is respectively attached with a corresponding polarization film with a size not smaller than the size of the exit pupil, the number, position and polarization direction of the polarization films corresponding to the exit pupil array are consistent with the number, position and polarization direction of one polarization property aperture in the corresponding aperture of the polarization characteristic optical waveguide projection unit, and the coupled exit pupils of the other N conventional optical waveguide projection units are combined into another exit pupil array, and a corresponding polarizing film with the size not smaller than the size of the exit pupil is attached to each exit pupil, the number, the position and the polarization direction of the polarizing films corresponding to the exit pupil array are consistent with the number, the position and the polarization direction of another polarization property aperture in the corresponding aperture of the polarization characteristic optical waveguide projection unit, M is not less than 1, and N is not less than 1.

18. The light field display system based on polarization characteristic optical waveguide coupled-out pupil division-combination control of claim 17, wherein in the complex-structured polarization characteristic optical waveguide projection unit, the M + N stacked conventional optical waveguide projection units share the image plane projection device or/and the compensation unit.

19. The light field display system based on time sequence characteristic light waveguide coupled light exit pupil segmentation-combination control is characterized by comprising the following components:

the time sequence characteristic optical waveguide projection unit stack structure is formed by stacking G time sequence characteristic optical waveguide projection units, each time sequence characteristic optical waveguide projection unit projects a virtual image which is divided into S sub-areas along the x direction to the + z direction, and the virtual image light information is transmitted and projected to the-z direction only through a time sequence characteristic optical waveguide projection unit coupling light exit pupil, wherein G is larger than or equal to 1, and S is larger than or equal to 2;

small-spacing aperture array with T x (S + G-1) adjacent spacing along x direction smaller than pupil diameter D of observer_pThe aperture composition of (1) is arranged in front of each coupling light exit pupil along the-z direction, S + G-1 apertures with intervals of T-1 apertures are respectively grouped, T aperture groups in the group are staggered by one aperture along the x direction, in each aperture group, every adjacent S apertures are respectively grouped into an aperture subgroup for the second time to form a T multiplied by G aperture subgroup, wherein T is not less than 1, and T multiplied by G is not less than 2;

in the time sequence characteristic optical waveguide projection unit stack structure, coupling exit pupils of adjacent time sequence characteristic optical waveguide projection units are sequentially staggered by T apertures along the x direction, G time sequence characteristic optical waveguide projection units with sequentially staggered coupling exit pupils respectively correspond to G aperture subgroups sequentially staggered in the same direction in each aperture group, and S apertures of each aperture subgroup correspond to S sub-regions of a virtual image projected by the corresponding time sequence characteristic optical waveguide projection units in the same direction one by one;

the control unit is used for opening only one aperture cluster consisting of apertures at intervals of V-1 apertures in sequence in only one aperture group at one time point, and controlling the T multiplied by V different aperture clusters of all the aperture groups to be opened only one cluster at a time at adjacent T multiplied by V time points within each time period delta T, wherein V is less than or equal to 2 and less than or equal to S;

when one aperture is opened, the corresponding sub-area on the virtual image projected by each time sequence characteristic optical waveguide projection unit is controlled to load information about the aperture, and the sub-area corresponding to the unopened aperture is not loaded with information;

the time sequence characteristic optical waveguide projection unit projects information of a virtual image sub-region about one aperture, and projects information of a virtual image region about a view of an aperture subgroup where the aperture is located on the sub-region for the time sequence characteristic optical waveguide projection unit;

the time sequence characteristic optical waveguide projection unit projects a view of a virtual image region about one aperture subgroup, and the viewpoint of the view is the intersection point of each sub-region of the virtual image projected by the time sequence characteristic optical waveguide projection unit and a straight line of the corresponding aperture of the sub-region in the aperture subgroup;

and a diaphragm attached to the small-pitch aperture array and blocking a portion of the light emitted from each of the timing characteristic optical waveguide projection units, which portion is transmitted through a region other than the aperture corresponding to the timing characteristic optical waveguide projection unit.

20. The light field display system according to claim 19, wherein when the subregions are equally spaced and the apertures are equally spaced, the coupling pupil of the adjacent sequential lightguide projection unit has an x-direction distance Δ D ≦ txsxΔ D, and the coupling pupil of each sequential lightguide projection unit has an x-direction width Δ W ≦ txsxΔ D.

21. The light field display system based on time-sequential characteristic optical waveguide coupled-exit pupil division-combination control of claim 20, wherein the time-sequential characteristic optical waveguide projection unit projects a view of the virtual image region about one of the aperture sub-groups from a viewpoint of an intersection of a center of each sub-region of the virtual image projected by the time-sequential characteristic optical waveguide projection unit and a line connecting the sub-region with a corresponding aperture center in the aperture sub-group.

22. The light field display system based on sequential characteristic optical waveguide coupled-exit pupil division-combination control of claim 19, wherein the sequential characteristic optical waveguide projection unit comprises: the pixel array consists of S areas, synchronously loads the projection information required by the time sequence characteristic optical waveguide projection unit and emits light beams; an optical waveguide composed of a base and a total reflection surface for transmitting an incident beam by total reflection; an optical incoupling device that incouples incident light into the optical waveguide; the relay device is arranged between the pixel array and the light incoupling device, and is used for modulating light beams emitted by each pixel of the pixel array in a phase mode and drawing the modulated light beams into the light incoupling device; an outcoupled light exit pupil, the optical waveguide transmitting a light exit aperture; the optical out-coupling device modulates and guides the light beams transmitted by the optical waveguide through total reflection to be turned to an out-coupling pupil; the image plane projection device is used for extending and converging light beams which are guided by the optical coupler out-coupling device and come from different pixels of the pixel array on each corresponding equivalent pixel on the projection plane along the + z direction in the opposite direction to form a virtual image of the pixel array on the projection plane, and the light beams emitted from the coupled light exit pupil are equivalent to the virtual image equivalent emergent light beams; and the compensation unit is arranged behind the optical coupler-out device along the-z direction and used for reversely eliminating the influence of the optical coupler-out device and the image plane projection device on the incident light of the external environment.

23. The light field display system based on sequential characteristic optical waveguide coupled-exit pupil division-combination control of claim 22, wherein the image plane projection device or/and the compensation unit are shared by the stacked sequential characteristic optical waveguide projection units.

24. The light field display system according to any of claims 19-23, wherein the state of T x V time points in each time period is switchable, and the stacking order of the G sequential characteristic light guide projection units is switchable.

25. The light field display system based on the polarized light time sequence characteristic light waveguide coupling light exit pupil segmentation-combination control is characterized by comprising the following components:

the polarization time sequence optical waveguide projection unit stack structure is formed by stacking G polarization time sequence optical waveguide projection units, each polarization time sequence optical waveguide projection unit projects a virtual image to the + z direction, and projects virtual image light information to the-z direction only through a coupling light exit pupil, wherein G is not less than 1;

the polarization time sequence optical waveguide projection unit stack structure is characterized in that each polarization time sequence optical waveguide projection unit projects a virtual image and consists of S sub-regions along the x direction, equivalent emergent light polarization states of the same polarization time sequence optical waveguide projection unit on adjacent sub-regions project the virtual image and are mutually orthogonal, equivalent emergent light polarization states of adjacent polarization time sequence optical waveguide projection units on sub-regions with the same sequence number along the x direction project the virtual image and are mutually orthogonal, wherein S is larger than or equal to 1;

small-spacing aperture array with T x (S + G-1) adjacent spacing along x direction smaller than pupil diameter D of observer_pThe aperture components are arranged in front of each coupling light exit pupil along the-z direction, S + G-1 apertures with T-1 apertures are respectively grouped, the T groups of apertures are staggered along the x direction, the adjacent apertures in each group of apertures allow the polarization states of light to pass through to be orthogonal when being opened, and the adjacent S apertures in each group of apertures are respectively secondarily grouped to form G aperture subgroups, wherein T is not less than 1, and T multiplied by G is not less than 2;

in each aperture group, starting from a first aperture along the x direction, the most adjacent apertures with different polarization states form a first mixed aperture, then in the aperture group, starting from the first aperture after the first mixed aperture, the same method defines a second mixed aperture, and the steps are repeated to determine all mixed apertures in the aperture group;

in the polarization time sequence optical waveguide projection unit stack structure, coupling exit pupils of adjacent polarization time sequence optical waveguide projection units are sequentially arranged in a staggered T-aperture mode along the x direction, G polarization time sequence optical waveguide projection units with the coupling exit pupils sequentially staggered correspond to G aperture sub-groups in each aperture group, the G aperture sub-groups are sequentially staggered in the same direction, S apertures of each aperture sub-group correspond to S sub-regions of a virtual image projected by the corresponding polarization time sequence optical waveguide projection units in the same direction one by one, and the polarization direction of emergent light is allowed to be consistent with the polarization direction of equivalent emergent light of the corresponding sub-region when each aperture is opened;

the control unit is used for opening only one aperture cluster formed by mixed apertures at intervals of V-1 mixed apertures in only one aperture group at one time point, controlling T multiplied by V different aperture clusters of all aperture groups to be opened at adjacent T multiplied by V time points in each time period delta T in sequence, and opening only one aperture cluster at one time point, wherein V is more than or equal to 2 and less than or equal to [ (S +1)/2], [ ] is an integer symbol;

when one aperture is opened, the corresponding sub-regions are controlled to load information;

the loading information of the sub-region corresponding to one aperture is information of a view of a polarized light time sequence optical waveguide projection unit projection virtual image region corresponding to the sub-region, wherein the view of the aperture sub-group corresponding to the polarized light time sequence optical waveguide projection unit belongs to the aperture, on the sub-region;

the view point of the virtual image region projected by the polarized light time sequence optical waveguide projection unit is the intersection point of each sub-region of the virtual image projected by the polarized light time sequence optical waveguide projection unit and the straight line of the corresponding aperture of the sub-region in the aperture subgroup;

and the diaphragm is attached to the small-distance aperture array and used for blocking the part of emergent light from each polarization time sequence optical waveguide projection unit, which is transmitted in the area except the corresponding aperture of the polarization time sequence optical waveguide projection unit.

26. The light field display system based on polarization time-sequential optical waveguide coupled exit pupil division-combination control of claim 25, wherein the sub-regions where each polarization time-sequential optical waveguide projection unit projects the virtual image overlap, and the equivalent exit light polarization states of the adjacent polarization time-sequential optical waveguide projection units projecting the virtual image on the same overlapping sub-region are mutually orthogonal.

27. The light field display system according to claim 26, wherein the subregions are equally spaced and the apertures are equally spaced, and when the adjacent polarization time-sequential light waveguide projection units have the coupled-out light pupil with an x-directional distance Δ D, the coupled-out light pupil of each polarization time-sequential light waveguide projection unit has an x-directional width Δ W ≦ T × S × Δ D.

28. The light field display system based on polarization time-sequential optical waveguide coupled light exit pupil division-combination control of claim 27, wherein the polarization time-sequential optical waveguide projection unit projects a view of the virtual image region with respect to the corresponding aperture sub-group from a viewpoint of an intersection of a center of each sub-region of the virtual image projected by the time-sequential optical waveguide projection unit and a line connecting the sub-region with the corresponding aperture center in the aperture sub-group.

29. The light field display system based on polarization time-sequential optical waveguide coupled exit pupil division-combination control of any one of claims 25 to 28, wherein the polarization time-sequential optical waveguide projection unit and the polarization characteristic optical waveguide projection unit adopt the same optical structure.

30. The light-field display system according to any of claims 25-28, wherein the T x V time-point states in each time period are switchable, and the stacking order of the G polarization-time sequential light-guide projection units is switchable.

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