Summary of the invention
Fundamental purpose of the present invention is to provide a kind of stereo projection display apparatus, the technical matters that brightness of image is low, quality is low and arrangement takes up space existing to solve existing projection stereo display technique.
The present invention solves aforesaid technical matters by the following technical programs:
A kind of stereo projection display apparatus, comprise display screen and array of rear-projectors, described display screen comprises from described array of rear-projectors is from the close-by examples to those far off close to the Fresnel Lenses of setting, longitudinal scattering layer and specular layer successively, and described Fresnel Lenses contacts with described longitudinal scattering layer with flat one side, and the focal length of described Fresnel Lenses horizontal direction is less than the focal length of vertical direction; Described longitudinal scattering layer is for carrying out the scattering in vertical direction to light; Described array of rear-projectors comprises at least two projector on the focal plane that is positioned over described Fresnel Lenses vertical direction; The parameter of described Fresnel Lenses can be watched index adjustment according to different, to form different viewing areas, the wherein said index of watching comprises viewing distance and viewing angle, and the parameter of described Fresnel Lenses comprises the focal length of horizontal direction and the focal length of vertical direction.
Preferably, described projector is short focal length laser-projector.
Preferably, each described projector is positioned on the horizontal line that same is parallel to ground.
Stereo projection display apparatus provided by the invention, compared with prior art, at least there is following beneficial effect: because the vertical direction focal length of Fresnel Lenses is greater than horizontal direction focal length, and projector is unlikely on the focal plane of lens vertical direction, so twice of vertical direction light is under Fresnel Lenses and the effect at longitudinal scattering film, when final outgoing, be parallel and level penetrates (between light, be parallel to each other and light parallel to the ground), and (direction parallel to the ground) in the horizontal direction converges when upper final outgoing.Thereby the light of projector outgoing passes through Fresnel Lenses for the first time, longitudinally scattering of warp after catoptron reflection, after Fresnel Lenses, pool for the second time a vertical arrowband (but human eye see be complete picture), because of the longitudinally effect of scattering layer, different height all can be seen complete picture again.In the time that the image of different visual angles is dropped into respectively people's right and left eyes by certain two projector, the vertical arrowband of two different visual angles is formed at respectively right and left eyes place, and human eye is experienced stereoeffect, thereby realizes bore hole stereo display.
In sum, in this programme, due to final emergent ray rarely obliquely or the light of oblique lower ejaculation in vertical direction, horizontal direction is also that level penetrates and converges in certain point, thereby has greatly reduced light loss, has improved the brightness of imaging, and external stray light in environment, its light source is seldom on the focal plane in Fresnel Lenses vertical direction, thus be difficult to imaging to cause interference, thus image quality is improved; In addition, in the time that the focal length of the vertical direction of Fresnel Lenses diminishes, projector just can arrange from display screen more close to, strengthened the dirigibility of arranging.
On the other hand, the stereo projection display apparatus of this programme can also be realized 2D/3D and switch, as long as by the image at the same visual angle of all projector projections or same road video, also can be only with a projector job, and before Fresnel Lenses, increase again the controlled horizontal dispersion layer of one deck, by its scattering properties of switch control, in the time of needs 2D, this film is horizontal dispersion film, light level scattering can be come, and makes optional position all can see same two-dimensional picture.
In the preferred scheme that adopts short focal length laser-projector, based on the Fresnel Lenses of adjustable parameters, be used in conjunction with short focal length laser-projector, projector can be arranged from screen more close to, even can be placed in front of screen, realized almost and entirely freely having arranged, and walking about of personnel can not stop light yet.
Embodiment
Preferred embodiment the invention will be further described to contrast accompanying drawing combination below.
Concept definition:
Horizontal direction: the direction that is parallel to ground;
Vertical direction: perpendicular to the direction on ground;
This specific embodiment part provides a kind of stereo projection display apparatus as depicted in figs. 1 and 2, comprise array of rear-projectors 10 and display screen 20, array of rear-projectors 10 comprises two above projector, for example, array of rear-projectors 10 comprises five projector in the present embodiment: 11,12,13,14,15; Display screen 20 comprises from array of rear-projectors 10 is from the close-by examples to those far off close to the Fresnel Lenses 21 of setting, longitudinal scattering layer 22 and specular layer 23 successively.The optical characteristics of Fresnel Lenses is equal to the convex lens of identical parameters, convex lens have the optical characteristics of both direction, horizontal direction and vertical direction, the optical characteristics control emergent ray of vertical direction angle in the vertical direction, and the optical characteristics control emergent ray of horizontal direction angle in the horizontal direction, common lens characteristic is in the horizontal and vertical directions the same, it is isotropic round lens, but in the present invention, Fresnel Lenses 21 focal distance f is in the horizontal direction less than the focal distance f ＇ of vertical direction.Array of rear-projectors 10 is arranged on the vertical direction focal plane of Fresnel Lenses 21, moreover, can also make all projector in preferred scheme on same level line (being parallel to ground).In this programme, can be according to watching index (viewing distance and viewing angle etc.), design the proper parameter of display screen, it is mainly the parameter of Fresnel Lenses, make the focal distance f of Fresnel Lenses horizontal direction be less than the focal distance f ＇ of vertical direction, and then according to the parameter of the position of array of rear-projectors and display screen, determine viewing areas.
Set forth layout principle and the imaging process of the stereo projection display apparatus of the present embodiment below.
For convenience of explanation, first set forth the imaging process of a projector, taking projector 13 as example: projector 13 is equivalent to a pointolite, because pointolite is positioned on the focal plane of vertical direction of Fresnel Lenses 21, so pointolite (is that object distance u) just equals the half (because light be twice by parallel ejaculation after Fresnel Lenses, so only need semicoke incident can realize parallel outgoing) of the vertical direction focal distance f ＇ of Fresnel Lenses 21 apart from the distance of Fresnel Lenses.The light that projector 13 sends incides Fresnel Lenses 21 with the form of dispersing, after Fresnel Lenses 21, (pass through for the first time), light level penetrates, because longitudinal scattering layer 22 is close to specular layer 23, when so light passes through longitudinal scattering layer 22 for the first time, longitudinally scattering layer 22 is equivalent to not have to the scattering process of light, light is after specular layer 23 reflections, pass through for the second time longitudinal scattering layer 22, this time light is played to the scattering process in vertical direction, light in vertical direction is scattered up and down, and (not understanding left and right scatters, because be longitudinal scattering), and it is unaffected to light travel path in the horizontal direction, then, light passes through Fresnel Lenses 21 for the second time, again produce the effect of converging, light ray parallel in vertical direction is penetrated, just as shown in (a) in Fig. 4, (a) be side view, and light in horizontal direction converges to space point, sees (b) in Fig. 4, be (b) vertical view, thereby light forms vertical arrowband after Fresnel Lenses at twice, just can watch complete picture the user of this point.This vertical arrowband projects people's a certain eyes, only have eyes can receive picture, and another does not have, in order to obtain stereoeffect, need to open another projector and carry out projection, if open projector 12, and make image or another road video of projector 12 projection different visual angles, according to aforesaid imaging process, people's another eye has received the picture from projector 12, thereby eyes have been seen the picture with depth information, produce stereoscopic sensation, i.e. bore hole 3D.
In the present invention, the parameter of Fresnel Lenses arranges and must ensure that the focal distance f ＇ in vertical direction is greater than the focal distance f in horizontal direction, and the radius-of-curvature in vertical direction is greater than the radius-of-curvature in horizontal direction, and concrete setting up procedure is as follows:
According to lens imaging formula: 1/u+1/v=1/f, for formula (1), wherein u is object distance, u is also the focal length of Fresnel Lenses vertical direction in the present invention, be u=f ＇, v is viewing distance, known: when v is positive number, be beholder between Fresnel Lenses and projector when (being Fresnel Lenses convex surface one side) (because there is the existence in reflection horizon, otherwise when v is positive number, observer should be the opposite side at lens), u is always greater than f's, so, according to formula (1), when known wherein both time, can calculate the value of another one, namely aforementioned description according to viewing distance, lens parameter is set, also can determine viewing distance according to the position of lens parameter and projector,
For example, as shown in Figure 5, first suppose a viewing distance v=3m (rice), viewing angle is for to become 30 ° with Fresnel Lenses primary optical axis, vertical direction focal length u (f ＇) is known, thereby calculates horizontal direction focal distance f according to formula (1), thereby completes the parameter setting of Fresnel Lenses, determine display screen, then:
As shown in Figure 5: suppose that the distance between adjacent projections instrument is E, the spacing of people's eyes is e, in order to experience stereoeffect, except aforesaid setting, twice, the picture that also needs to ensure the projection of adjacent projections instrument through Fresnel Lenses out after, meet at the spacing E of viewing distance place imaging ＇:
E=nE ＇, n=1,2,3..., this is formula (2);
For example: in the time of u=2f, according to formula (1), can obtain v=2f, i.e. viewing distance v=u, watches at projector place, this kind of situation E=E ＇.While getting n=1, human eye is seen respectively the picture of projector 11 and 12 projections, and in the time of n=2, human eye is seen respectively the picture of projector 11 and 13.
In addition, because Fresnel Lenses is imaged as inverted real image, in order to obtain display frame accurately, need in advance video or image source to be processed, make it left and right upset, Cai getable picture in the right direction.
Suppose in the situation that there is no longitudinal scattering layer, through after lensing, view picture picture has become vertical rectangular, can only see part picture in certain position, just must carry out scattering to light, make the people of different height can watch image, crosstalk for fear of the light between different projector, just need to carry out longitudinal scattering, make light only carry out in vertical direction scattering.
Projector is usually arranged in screen below, project to picture non-rectangle on vertical display screen, now just need to carry out skew control to image, and common projector projection correction ability is effective, so restricted for projector distance, under this situation, whole system will take larger space, in order to alleviate this restriction, in preferred version of the present invention, adopt the short focal length laser-projector (as LG HECTO projector) with stronger calibration capability, so, can arrange more flexibly projector, even projector directly can be arranged in front of display screen, almost completely freely arrange this stereo projection display apparatus thereby realize.
And in order to realize the changeable broadcasting of 2D/3D, have two kinds of implementations: simple the most a kind of is the identical images of all projector projections, and it is poor that the effect obtaining like this shows than traditional two dimension, and cost also will be higher than traditional two-dimentional display system; Another is before Fresnel Lenses layer, to increase the controlled horizontal dispersion film of one deck, by its scattering properties of switch control: in the time that needs 2D shows, this film is horizontal dispersion film, light level scattering can be come, make optional position all can see picture, now only need to open a projector; In the time that needs 3D shows, this film is transmission film, does not carry out any scattering, is equivalent to not exist, and now all projector all need in running order.
Above content is in conjunction with concrete preferred implementation further description made for the present invention, can not assert that specific embodiment of the invention is confined to these explanations.For those skilled in the art, without departing from the inventive concept of the premise, can also make some being equal to substitute or obvious modification, and performance or purposes identical, all should be considered as belonging to protection scope of the present invention.