CN101881936B - Holographical wave guide display and generation method of holographical image thereof - Google Patents

Abstract

The invention belongs to an image display device and a method, relating to a holographical wave guide display taking a planar wave guide as a display screen and a generation method of a holographical image adaptive to the holographical wave guide display. The holographical wave guide display comprises a wave guide serving as the display screen and a holographcal projection system used for inputting the holographical image to the wave guide; the wave guide is provided with a light input panel and a light output panel; the incident light ray can be transmitted in the wave guide until leaving the wave guide from the light output panel; and the emergent position of the light ray on the light output panel is mutually determined by the position of point of incidence and the incidence angle of the light ray on the incidence panel. The holographical wave guide display of the invention can display the holographical image, can adopt the wave guide as a display carrier to manufacture the display which has jumbotron, low cost and environment protection and is energy-saving, sturdy and durable.

Description

The generation method of holographical wave guide display and hologram image thereof

Technical field

The invention belongs to image display device and method, relate to a kind of generation method of the hologram image of take holographical wave guide display that slab guide is display screen and adapting with this holographical wave guide display.

Background technology

Holography be a kind of by image transitions for its diffraction pattern at a certain specific range, and use one or more monochromatic sources to irradiate the technology of diffraction patterns.After the propagation through specific range, due to diffraction of light and interference effect, this diffraction pattern can be reduced into former target image.Compare and common projection and lcd technology, line holographic projections has the following advantages:

1. energy-conservation: different from the unwanted light of LCD shielding, holographic modulation also guides light, and the luminous energy of all incidents all will be used effectively in theory.The efficiency of light energy utilization of liquid crystal display is between 10-20% according to statistics, and the holography that adopts binary phase modulation technique (binary-phase modulation) shows that the efficiency of light energy utilization is more than 40%, and polynary phase modulation technique (multi-phase modulation) can be brought up to the efficiency of light energy utilization more than 90%.In addition, compare the white light bulb that traditional shadow casting technique is used, the LASER Light Source that line holographic projections is used or photodiode light source have very high energy conversion efficiency.

2. volume is little, simple in structure: than conventional projector, show that the aberration of image can be corrected by computed hologram itself, saved thus the bulky complex arranged and the expensive lens combination that differ for rectification.In addition, for coloured image, the line holographic projections instrument uses three kinds of monochromatic sources of red green basket, and the common projection of the white light that its chromatic aberration correction also comprises all spectrum more than use is easy.

3. stability is high: traditional display technique demonstration image and projection chip or indicator screen and show image are point-to-point corresponding relation, if a bad point is arranged on chip or screen, just show image produces a bad point.And line holographic projections is in spatial light modulator (Spatial Light Modulator, SLM), upper what show is the hologram through specific calculations, and its ultimate principle has guaranteed will produce never bad point on screen.Certain spectrum information on the corresponding screen picture of picture element of hologram image but not particular pixels point, the hypothesis space photomodulator is distinguished as 1000x1000, amount to 1,000,000 picture elements, on it, 1 bad point is changed to 1/1000000th and without corresponding bad point to what show that image causes, naked eyes can't be discovered at all, even hundreds of bad points are arranged on spatial light modulator, it is also only several per milles on the impact that shows image, and naked eyes are difficult for discovering.

Reported a kind of tapered transmission line display of applying conventional projector in patent CN1217539C, its advantage is to save the required light path of conventional projection, thin more next than traditional rear projection display of its thickness, and can compare favourably with flat-panel monitors such as liquid crystal plasmas.Because waveguide can be compared and liquid crystal by cheap optical glass or transparent plastic sheet manufacture, the classic flat-plate display techniques such as plasma, when making the large scale screen, its cost will be very cheap.Because waveguide itself does not contain any electronic devices and components, compare liquid crystal in addition, plasma, the displays such as photodiode, Waveguide display is more firm, durable in use.But existing this Waveguide display is used conventional projection, for correction differs aberration, the structure of waveguide is comparatively complicated and be difficult for manufacturing.Huge volume and the complicated lens combination of conventional projector also limited its application on waveguide shows in addition.

Summary of the invention

Technical matters to be solved by this invention is, but a kind of display holography image is provided, can adopt simultaneously waveguide as showing carrier, can manufacture jumbotron, the generation method of with low cost, energy-conserving and environment-protective, robust holographical wave guide display and the hologram image that adapts with this holographical wave guide display.

Holographical wave guide display of the present invention comprises one as the waveguide of display screen and is used for to the holographic projection system of waveguide input hologram image; Described waveguide has optical input surface and light output plane, and incident ray can be propagated until it leaves waveguide from the light output plane in waveguide, and by it, incidence point position and the incident angle on optical input surface determines jointly in the outgoing position of light on the light output plane.

The side original shape of described waveguide is triangle, and the front end drift angle is α, for saving material, the excision of front end nonuseable part can be made it to become wedge shape, and its rear end is the optical input surface that and positive light output plane become the β angle.

The first half section of described waveguide is viewing area, and the second half section is the image diffusion zone, and the image diffusion zone is foldable to the back side, viewing area to save space hold.

Described holographic projection system includes light source, be used for to light source is carried out phase place or intensity modulated and exports the modulation of source module of required image.

The light source that described holographic projection system also includes between light source and modulation of source module importation expands correction module.

Described holographic projection system also can include the image amplification correction module that is positioned at modulation of source module output.

Described holographic projection system also includes a control module, control module is controlled switch and the output power of light source, when the modulation of source module is convertible on it during the device of show image, control module is accepted the input image, and export accordingly hologram image to the modulation of source module, and make itself and light source export synchronised.

Described control module also can include for common image synchronous being converted to the hologram image generation module of hologram image.When control module comprises the hologram image generation module, it can receive common image, then is converted to hologram image; When control module does not comprise the hologram image generation module, it can directly receive the hologram image generated by external system.

The hologram image generation method that is adapted to above-mentioned wedge-shaped waveguide of the present invention operates in above-mentioned hologram image generation module or external system, and described hologram image generation module or external system can be electronic chip or the computers such as single-chip microcomputer, digit chip (DSP), field programmable gate array (FPGA).

The hologram image generation method that is adapted to above-mentioned wedge-shaped waveguide of the present invention comprises a waveguide inverse transformation, and the waveguide inverse transformation comprises the following steps:

(1) image of required demonstration added to phase factor;

(2) light according to different angles is divided into one or more zones in the principle of zones of different outgoing by full screen;

(3) image of corresponding region is done to Fourier transform or inverse fourier transform, get the corresponding wave band of result, obtain its angular spectrum;

(4) the contrary A as a result that propagates (3)_n(f_x, f_y), the angular spectrum after propagation${A_n}^{\&prime;}(f_x,f_y)=A_n(f_x,f_y)\&times;{\mathrm{<figure-callout\; label="e\; jkL\; sin"\; filenames="HFW00000064900200042.png"\; state="\{\{state\}\}">e</figure-callout>}}^{\mathrm{jkL}\sin }$K=2 π/λ wherein, λ is the incident light wavelength; L is the distance from wedge-shaped waveguide triangle prolongation summit to the waveguide end, the drift angle that α is wedge-shaped waveguide triangle prolongation;

(5) by A_n' (f_x, f_y) retrograde rotation pi/2-2n α; (due to hologram image, to the anglec of rotation insensitive, need not rotate also and can obtain more satisfied picture quality in most situation, so this step also can be omitted)

(6) calculate and compensate the impact caused due to air waveguide interface and lens combination;

(7) by all angular spectrum stacks, then do inverse fourier transform or Fourier transform, the phase and magnitude that obtains space distributes;

(8) last selecting range or phase place quantizes the generating hologram picture according to used modulation of source module in the lump.

In the step of above-mentioned waveguide inverse transformation, step (1) can be exchanged mutually with the order of step (2).

In the step of above-mentioned waveguide inverse transformation, step (6)～(7) can also be replaced by the following step:

A. calculate and compensate the impact that cause at different interfaces;

B. all angular spectrums are superposeed, then do inverse fourier transform or Fourier transform, the phase and magnitude that obtains space distributes;

C. calculate the impact that also the offset lens system causes.

In order to improve the display quality of image, hologram image generation method of the present invention can also be: at first input picture is calculated to hologram image by the waveguide inverse transformation, after quantizing by the waveguide transformation calculations, hologram image is at the phase and magnitude of light output plane again, get its phase place, and join original input image; Recalculate again hologram image; Repeat above step, until after meeting the number of times of setting, then export the hologram image obtained to the modulation of source module; Described waveguide conversion comprises the following steps:

(1) hologram image is done to inverse fourier transform or Fourier transform obtains its angular spectrum, and be divided into one or more wave bands, obtain each wave band angular spectrum;

(2) impact that cause at calculating offset lens and different interface;

(3) by the result rotation pi/2-2n α obtained in (2); (due to hologram image, to the anglec of rotation insensitive, need not rotate also and can obtain more satisfied picture quality in most situation, so this step also can be omitted)

(4) propagate the A as a result of (3)_n(f_x, f_y), the angular spectrum after propagation${A_n}^{\&prime;}(f_x,f_y)=A_n(f_x,f_y)\&times;e^{-\mathrm{<figure-callout\; label="jkL\; sin"\; filenames="HFW00000064900200042.png"\; state="\{\{state\}\}">jkL</figure-callout>}\sin 2\mathrm{n\&alpha;}\sqrt{1-{\left(\mathrm{\&lambda;}{f}_x\right)}^2-{\left(\mathrm{\&lambda;}{f}_y\right)}^2}}$K=2 π/λ wherein, λ is the incident light wavelength; L is the distance from wedge-shaped waveguide triangle prolongation summit to the waveguide end, the drift angle that α is wedge-shaped waveguide triangle prolongation;

(5) each wave band is done respectively to Fourier transform or inverse fourier transform, and only get amplitude and the PHASE DISTRIBUTION of its corresponding region;

(6) each regional amplitude and PHASE DISTRIBUTION stack are obtained to total amplitude and PHASE DISTRIBUTION.

In the step of above-mentioned waveguide conversion, step (1)～(2) can be replaced by the following step:

A. calculate the impact that also the offset lens system causes;

B. hologram image is done to inverse fourier transform or Fourier transform obtains its angular spectrum, and be divided into one or more wave bands, obtain each wave band angular spectrum;

C. calculate and compensate the impact that cause at different interfaces.

In the step of above-mentioned waveguide conversion, the order of step (3) and (4) can be exchanged.

In order further to improve the display quality of image, hologram image generation method of the present invention can also be to the above-mentioned hologram image of modulation of source module that exports to by showing multiframe nuance image at short notice fast, utilize the human eye vision residual effect, make it be stacked Calais on retina and reduce error, its concrete steps are as follows:

(1) determine that every frame shows that image is comprised of how many frame subimages, counts M;

(2) input picture is added to phase factor, the desirable random phase of the initial phase factor.Determine that each sub-frame images needs the times N of iteration;

(3) carry out the waveguide inverse transformation, obtain required hologram image;

(4) judge whether to reach iterations, if operating procedure (5) moves the waveguide conversion if not, the phase and magnitude that obtains quantizing the demonstration image that hologram image is corresponding distributes, and gets its phase place, is added to original input image, and rebound step (3);

(5) will quantize hologram image is presented on the modulation of source module as a subframe;

(6) judged whether the demonstration of all subframes of this image, if input the next frame image, rebound step (1); Move if not the waveguide conversion, the amplitude of the amplitude of gained image and original input image is compared, according to errors, the intensity of original input image is modified, then rebound step (2).

Holographical wave guide display of the present invention is compared and general projectors, has a volume little, and cost is low, energy-conserving and environment-protective, the stable advantage such as not fragile.Compare common line holographic projections technology, the present invention shows and combines with waveguide, makes product have screen, has saved the required optical path space of projector, and with the ordinary flat display, is as good as in profile and use.Combine with waveguide and can make product there is the touch-screen of being transformed in addition, transparent display, the space of the following application of three dimensional display etc.

The accompanying drawing explanation

Fig. 1 is the structural representation that has shown the holographical wave guide display embodiment of the present invention of waveguide side structure;

Fig. 2 is the plan structure schematic diagram of Fig. 1;

Fig. 3 is the structural representation that has shown another embodiment of holographical wave guide display of the present invention of waveguide side structure;

Fig. 4 is the plan structure schematic diagram of Fig. 3;

Fig. 5 is the holographic projection system schematic diagram of one embodiment of the invention;

Fig. 6 is the holographic projection system schematic diagram of another embodiment of the present invention;

Fig. 7 is a kind of enforceable index path of schematic diagram shown in Fig. 6;

Fig. 8 is the hologram image generating principle figure of wedge-shaped waveguide;

Fig. 9 is the process flow diagram of waveguide inverse transformation;

Figure 10 is the process flow diagram of waveguide conversion;

Figure 11 is a kind of schematic diagram that reduces the method for hologram image error.

Embodiment

As shown in Figure 1, 2, the holographical wave guide display of the embodiment of the present invention comprises a waveguide as display screen 11 and is used for to the holographic projection system 12 of waveguide input hologram image.The shape of waveguide can be as shown in Figure 1, and the side original shape is triangle, and its front end drift angle is α, for saving material, the front end nonuseable part can be excised, make it to become wedge shape, for ease of light incident, the waveguide rear end can be designed to one after as calculated and become the plane at β angle with exit facet.Its vertical view can be rectangle, triangle, or other is convenient to the shape shown.It is latter half of as image diffusion zone 111(light propagation region), first half is used for show image as viewing area 112.Wherein thereby space (as Fig. 3, Fig. 4) is saved at the latter half of first half back side that also is collapsible into), Waveguide display shape and ordinary flat display are as good as, one bed interface is wherein arranged between image diffusion zone and screen, can be air or special media, only reflect and not outgoing on this interface to guarantee light.Can plate one deck anti-reflection film (anti-reflection film) in screen surface, to guarantee light, reach all outgoing after shooting angle, eliminate impact image caused because of secondary reflection.

As shown in Figure 5, Figure 6, holographic projection system comprises following part:

Light source: light source adopts monochromatic source, for example laser or photodiode.Red by using, green, three kinds of monochromatic sources of basket, can obtain coloured image.

Light source expands correction module and image amplification correction module: they are for being amplified and proofreaied and correct by laser beam expanding and correction and to the image output of modulation of source module.Can be for example that directional light is used for irradiating optical modulator module by the Light source correction after expanding, and amplify the hologram of output by lens combination.

The modulation of source module: this module is used for to light source is carried out phase place or intensity modulated and exports required image.It can adopt liquid crystal over silicon System on Chip/SoC (LCOS), digital micromirror elements (DMD), or hologram, grating array etc.If adopt liquid crystal over silicon System on Chip/SoC (LCOS), the devices such as digital micromirror elements (DMD), the hologram image shown on it can carry out the high speed switching by control module, thereby realizes the output of dynamic video stream.

Control module: control module is strong and weak for switch and the output of controlling light source, and it can be by single-chip microcomputer, digit chip (DSP), electronic chip and the circuit formations such as field programmable gate array (FPGA).If the spatial light modulation module adopts liquid crystal over silicon System on Chip/SoC (LCOS), digital micromirror elements (DMD) etc. can realize converting the device of show image on it, control module will be accepted the input image, and export accordingly hologram image to the spatial light modulation module, and make itself and light source export synchronised.In addition, if be input as common image, control module will comprise the hologram image generation module, realize that ordinary video is to the real-time synchronization conversion of hologram image, export the hologram image of generation to the spatial light modulation module again, and keep light source to synchronize (as Fig. 5) with it.If control module be input as hologram, this module can not contain the hologram image modular converter.Control module directly will be inputted hologram and output to the spatial light modulation module, and the strong and weak and corresponding image maintenance of light source is synchronizeed (as Fig. 6), and ordinary video flow to the transfer process of hologram image video flowing and can be completed by outside computing machine.

Figure 7 shows that a kind of feasible specific implementation light path of schematic diagram shown in Fig. 5.Wherein light source is used red, green, three kinds of one-wavelength lasers of basket, and light source expands correction and image amplification correction module consists oflens 1～lens 5.Lens 1,2,3 are the Light source correction lens, make respective sources be converted to plane wave by nonplanar wave.Lens 4,5 form reverse telescope configuration, for amplifying the hologram of modulation of source module output.The spatial light modulation module can realize the phase-modulation to light after using liquid crystal over silicon System on Chip/SoC (LCOS) to add polaroid.Control module is used digit chip (DSP) or field programmable gate array (FPGA), and realization is converted to the common image real-time synchronization of input the function of hologram image, and the output of synchronous light source and hologram image.

Can have multiple light path to realize the principle of Fig. 5 or 6, Fig. 7 is only a kind of scheme wherein.Fig. 5 or 6 principle also can configure by the laser of every kind of color a modulation of source device and realize, for example in whole system, contain 3 liquid crystal over silicon System on Chip/SoCs (LCOS) thus modulated red, green, three kinds of light sources of basket improve picture qualities respectively.

The propagation of light in waveguide is different from the circulation way in free space.Therefore the hologram in waveguide generate also will distinguish and free space in the generation method.The waveguide of wedge structure of the present invention, the incident light of different angles can be become to be projected on the exit plane of different rotation angle by equivalence.The side view that Fig. 8 is wedge-shaped waveguide, there is plated film on its surface, and the waveguide drift angle is α, and height is H, and long is L.It is θ that light enters incident angle after waveguide, and as calculated, angle belongs to (θ_in, θ_in+ 2 α] the projection of light can be equivalent on the waveguide surface be projected in after rotation 2m α, and angle belongs to (θ_in-2 α, θ_in] light be equivalent to and be projected on the waveguide surface of rotation after 2 (m+1) α.

Fig. 9 is a kind of method that generates the waveguide hologram image, is called the waveguide inverse transformation in the present invention.Its step is as follows:

1. the image T (x, y) of required demonstration is added to phase factor T (x, y) * e^{j Φ (x, y)}, initial phase factor Φ (x, y) can be random phase;

2. the light according to different angles is divided into N zone (interregional partly overlapping, the incident light of different angles is because of the different same point outgoing on screen of incidence point), N wave band T on the corresponding angles frequency spectrum respectively in the principle of zones of different outgoing by full screen_n(x, y)=T (x, y) * e^{j Φ (x, y)}* P_n(x, y), wherein$P_n(x,y)=\left\{\begin{array}{cc}1& (x,y)\&Element;R_n\\ 0& (x,y)\&NotElement;R_n\end{array}\right.$Play the spatial filter effect, R_nfor corresponding screen area;

3. the image of regional n is done to Fourier transform or inverse fourier transform, and only get the n wave band of result, obtain its angular spectrum, A_n(f_x, f_y)=F{T_n(x, y) } * Q_n(f_x, f_y), wherein F{} is wherein Fourier or inverse fourier transform,$Q_n(f_x,f_y)=\left\{\begin{array}{cc}1& (f_x,f_y)\&Element;S_n\\ 0& (f_x,f_y)\&NotElement;S_n\end{array}\right.,$Play the angular spectrum wave filter, S_nfor corresponding wave band;

4. against propagating A_n(f_x, f_y).Angular spectrum after propagation${A_n}^{\&prime;}(f_x,f_y)=A_n(f_x,f_y)\&times;{\mathrm{<figure-callout\; label="e\; jkL\; sin"\; filenames="HFW00000064900200042.png"\; state="\{\{state\}\}">e</figure-callout>}}^{\mathrm{jkL}\sin }$K=2 π/λ wherein, λ is the incident light wavelength;

5. calculate A_n' (f_x, f_y) result (if the anglec of rotation is little, this step also can be omitted) after retrograde rotation pi/2-2n α;

6. calculate and compensate the empty impact caused due to air waveguide interface and lens combination;

7. all angular spectrums are superposeed, then do inverse fourier transform or Fourier transform, the phase and magnitude that obtains space distributes.

In the method, the order of step can adjust, to adapt to different system.Finally selecting range or phase place quantizes the generating hologram picture according to used modulation of source module in the lump, for example, modulation of source module for the binary phase modulation, a kind of quantization method is to take to make all phase places to be greater than 0 point to get pi/2, be less than 0 get-pi/2 of point, thereby obtain a binary hologram.

Step 3,4,6 can be expressed as on mathematics

$\begin{array}{c}{F}^{-1}\left\{F\right\{T(x,y)\&times;e^{\mathrm{j\&Phi;}(x,y)}\&times;P_n(x,y)\}\&times;S_n\&times;{\mathrm{<figure-callout\; label="e\; jkL\; sin"\; filenames="HFW00000064900200042.png"\; state="\{\{state\}\}">e</figure-callout>}}^{\mathrm{jkL}\sin }\}\\ =[T(x,y)\&times;e^{\mathrm{j\&Phi;}(x,y)}\&times;P_n(x,y)]*F^{-1}\{S_n\&times;{\mathrm{<figure-callout\; label="e\; jkL\; sin"\; filenames="HFW00000064900200042.png"\; state="\{\{state\}\}">e</figure-callout>}}^{\mathrm{jkL}\sin }\}\end{array}$

Wherein * is convolution algorithm, becauseirrelevant with concrete image, so but calculated in advance storage, thus can use a convolutional calculation to replace Fourier transform twice, thus improve arithmetic speed.

Said method is reversible in addition, only need slightly revise, and just can obtain the waveguide conversion (Figure 10) of computed hologram at screen display:

(1) hologram image is done to inverse fourier transform or Fourier transform obtains its angular spectrum, and be divided into one or more wave bands, obtain each wave band angular spectrum;

(2) impact that cause at calculating offset lens and different interface;

(3) by the result rotation pi/2-2n α (if the anglec of rotation is little, this step also can be omitted) obtained in (2);

(4) propagate the A as a result of (3)_n(f_x, f_y), obtain angular spectrum${A_n}^{\&prime;}(f_x,f_y)=A_n(f_x,f_y)\&times;{\mathrm{<figure-callout\; label="e\; jkL\; sin"\; filenames="HFW00000064900200042.png"\; state="\{\{state\}\}">e</figure-callout>}}^{\mathrm{jkL}\sin }$K=2 π/λ wherein, λ is the incident light wavelength;

(5) each wave band is done respectively to Fourier transform or inverse fourier transform, and only get amplitude and the PHASE DISTRIBUTION of its corresponding region;

(6) each regional amplitude and PHASE DISTRIBUTION stack are obtained to total amplitude and PHASE DISTRIBUTION.

The order of above-mentioned steps can according to circumstances be adjusted.

Quantizing process will produce error, for improving picture quality, can utilize the persistence of vision effect of human eye and the high refresh rate of modulation of source module to realize that the quick demonstration of image reduces to quantize on the modulation of source module due to hologram the error caused.For example, a liquid crystal over silicon System on Chip/SoC (LCOS) that refresh rate is 1024 hertz of per seconds, per second can show 1024 two field pictures, by one second 24 two field picture note of ordinary video, every two field picture can be comprised of 42 frame subimages, between subimage, exist nuance with making up error to each other, due to the persistence of vision effect of human eye, the image finally observed will have very high quality.(introduced a kind of aberration correcting method of two-dimension holographic projection in free space in patented claim CN101310225A.The difference correction used in the present invention based on waveguide conversion but not simple Fourier transform is obviously different from its existence), waveguide hologram of the present invention bearing calibration is as Figure 11:

1. input a frame new images, determine that it is comprised of how many frame subimages, counts M

2. input picture is added to phase factor, the desirable phase place immediately of the initial phase factor.Determine and calculate the times N that each sub-frame images needs iteration.

3. carry out the waveguide inverse transformation, obtain required hologram image

4. judge whether to reach iterations, if operating procedure 5 moves the waveguide conversion if not, obtain quantizing the corresponding phase and magnitude distribution that shows image of hologram image institute, get PHASE DISTRIBUTION, be added to input picture in 2, and rebound step 3

5. will quantize hologram image is presented on the modulation of source module as a subframe

6. judged whether the demonstration of all subframes of this image, if input the next frame image, rebound step 1.Move if not the waveguide conversion, the amplitude of the amplitude of gained image and original input image is compared, according to errors, by specific process, the intensity of original input image is carried out to trickle modification, then reboundstep 2.

Step 2 is adoptable lid Shi Beige-Sa Ke stone (Gerchberg-Saxton) or Liu-Tai (Liu-Taghizadeh) method during to the common hologram of 5 similar calculating, utilize phase freedom, optimize phase place by iteration, thereby obtain the hologram image that quality is higher.Step 7 realizes that the Error Feedback that will quantize to produce is to input picture, and revises the shown image of next subframe by specific process, to making up the error of current sub-frame images.

Claims (16)

1. a holographical wave guide display is characterized in that: it comprises a waveguide as display screen (11) and is used for to the holographic projection system (12) of waveguide input hologram image; Described waveguide has optical input surface and light output plane, and incident ray can be propagated until it leaves waveguide from the light output plane in waveguide, and by it, incidence point position and the incident angle on optical input surface determines jointly in the outgoing position of light on the light output plane; Described waveguide is that the side original shape is triangle, the wedge shape excision of front end nonuseable part formed for saving material, and its rear end is optical input surface, front is the light output plane.

2. holographical wave guide display according to claim 1, it is characterized in that: the first half section of described waveguide is viewing area (112), and the second half section is image diffusion zone (111), and the image diffusion zone is folded to the back side, viewing area.

3. according to the described holographical wave guide display of one of claim 1～2, it is characterized in that: described holographic projection system includes light source, be used for to light source is carried out phase place or intensity modulated and exports the modulation of source module of required image.

4. holographical wave guide display according to claim 3, it is characterized in that: the light source that described holographic projection system includes between light source and modulation of source module importation expands correction module.

5. holographical wave guide display according to claim 3, it is characterized in that: described holographic projection system includes the image amplification correction module that is positioned at modulation of source module output.

6. holographical wave guide display according to claim 3, it is characterized in that: described holographic projection system also includes a control module, control module is controlled switch and the output power of light source, the modulation of source module is the convertible device of show image on it, control module is accepted the input image, and export accordingly hologram image to the modulation of source module, and make itself and light source export synchronised.

7. holographical wave guide display according to claim 6, it is characterized in that: described control module includes for common image synchronous being converted to the hologram image generation module of hologram image.

8. a hologram image generation method that is adapted to the described holographical wave guide display of claim 3, it is characterized in that: it comprises a waveguide inverse transformation, and the waveguide inverse transformation comprises the following steps:

(1) image of required demonstration added to phase factor;

(2) light according to different angles is divided into one or more zones in the principle of zones of different outgoing by full screen;

(3) image of corresponding region is done to Fourier transform or inverse fourier transform, get the corresponding wave band of result, obtain its angular spectrum;

(4) the contrary A as a result that propagates (3)_n(f_x, f_y), the angular spectrum after propagation${A_n}^{\&prime;}(f_x,f_y)=A_n(f_x,f_y)\&times;e^{\mathrm{jkL}\sin 2\mathrm{n\&alpha;}\sqrt{1-{\left(\mathrm{\&lambda;}{f}_x\right)}^2-{\left(\mathrm{\&lambda;}{f}_y\right)}^2}}$K=2 π/λ wherein, λ is the incident light wavelength, L is the distance from wedge-shaped waveguide triangle prolongation summit to the waveguide end, the drift angle that α is wedge-shaped waveguide triangle prolongation

(5) by A_n' (f_x, f_y) retrograde rotation pi/2-2n α;

(6) calculate and compensate the impact caused due to air waveguide interface and lens combination;

(7) by all angular spectrum stacks, then do inverse fourier transform or Fourier transform, the phase and magnitude that obtains space distributes;

(8) last selecting range or phase place quantizes the generating hologram picture according to used modulation of source module in the lump.

9. the hologram image generation method that is adapted to the described holographical wave guide display of claim 3 according to claim 8, it is characterized in that: described waveguide inverse transformation is in its step, described step (5) to be omitted.

10. the hologram image generation method that is adapted to the described holographical wave guide display of claim 3 according to claim 8, it is characterized in that: described waveguide inverse transformation is in its step, step (1) to be exchanged mutually with the order of step (2).

11. be adapted to the hologram image generation method of the described holographical wave guide display of claim 3 according to claim 8, it is characterized in that: described waveguide inverse transformation is in its step, step (6)～(7) to be replaced by the following step:

A. calculate and compensate the impact that cause at different interfaces;

B. all angular spectrums are superposeed, then do inverse fourier transform or Fourier transform, the phase and magnitude that obtains space distributes;

C. calculate the impact that also the offset lens system causes.

A 12. hologram image generation method that is adapted to the described holographical wave guide display of claim 3, it is characterized in that: at first input picture is calculated to hologram image according to the described waveguide inverse transformation of one of claim 8～11, after quantizing by the waveguide transformation calculations, hologram image is at the phase and magnitude of light output plane again, get its phase place, and join original input image; Recalculate again hologram image; Repeat above step, until after meeting the number of times of setting, then export the hologram image obtained to the modulation of source module;

Described waveguide conversion comprises the following steps:

(1) hologram image is done to inverse fourier transform or Fourier transform obtains its angular spectrum, and be divided into one or more wave bands, obtain each wave band angular spectrum;

(2) impact that cause at calculating offset lens and different interface;

(3) by the result rotation pi/2-2n α obtained in (2);

(4) propagate the A as a result of (3)_n(f_x, f_y), the angular spectrum after propagation${A_n}^{\&prime;}(f_x,f_y)=A_n(f_x,f_y)\&times;e^{-\mathrm{jkL}\sin 2\mathrm{n\&alpha;}\sqrt{1-{\left(\mathrm{\&lambda;}{f}_x\right)}^2-{\left(\mathrm{\&lambda;}{f}_y\right)}^2}}$K=2 π/λ wherein, λ is the incident light wavelength, L is the distance from wedge-shaped waveguide triangle prolongation summit to the waveguide end, the drift angle that α is wedge-shaped waveguide triangle prolongation;

(5) each wave band is done respectively to Fourier transform or inverse fourier transform, and only get amplitude and the PHASE DISTRIBUTION of its corresponding region;

(6) each regional amplitude and PHASE DISTRIBUTION stack are obtained to total amplitude and PHASE DISTRIBUTION.

13. be adapted to the hologram image generation method of the described holographical wave guide display of claim 3 according to claim 12, it is characterized in that: described waveguide conversion is in its step, step (3) to be omitted.

14. be adapted to the hologram image generation method of the described holographical wave guide display of claim 3 according to claim 12, it is characterized in that: described waveguide conversion is in its step, step (1)～(2) to be replaced by the following step:

A. calculate the impact that also the offset lens system causes;

B. hologram image is done to inverse fourier transform or Fourier transform obtains its angular spectrum, and be divided into one or more wave bands, obtain each wave band angular spectrum;

C. calculate and compensate the impact that cause at different interfaces.

15. be adapted to the hologram image generation method of the described holographical wave guide display of claim 3 according to claim 12, it is characterized in that: described waveguide conversion is in its step, the order of step (3) and (4) to be exchanged.

16., according to the described hologram image of one of claim 12～15 generation method, it is characterized in that: to exporting the hologram image of modulation of source module to, carry out the processing of following steps:

(1) determine that every frame shows that image is comprised of how many frame subimages, counts M;

(2) input picture is added to phase factor, the initial phase factor is got random phase; Determine that each sub-frame images needs the times N of iteration;

(3) carry out the waveguide inverse transformation, obtain required hologram image;

(4) judge whether to reach iterations, if operating procedure (5) moves the waveguide conversion if not, the phase and magnitude that obtains quantizing the demonstration image that hologram image is corresponding distributes, and gets its phase place, is added to original input image, and rebound step (3);

(5) will quantize hologram image is presented on the modulation of source module as a subframe;

(6) judged whether the demonstration of all subframes of this image, if input the next frame image, rebound step (1); Move if not the waveguide conversion, the amplitude of the amplitude of gained image and original input image is compared, according to errors, the intensity of original input image is modified, then rebound step (2).

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