Projection display system

Abstract

The embodiment of the application provides a projection display system, and belongs to the technical field of projection display. The projection display system comprises a lens, at least two spatial light modulators and a light combination device. The lens comprises a rear-end lens group and at least two front-end lens groups, the at least two front-end lens groups are respectively located on the two sides of an aperture stop position of the lens, and the front-end light paths of the rear-end lens group are combined into one light path at the aperture stop position of the lens. The at least two spatial light modulators correspond to the at least two front-end lens groups one by one and are located in the front-end light paths of the corresponding front-end lens groups, and the light combination device is arranged at the aperture stop position of the lens and comprises guide surfaces corresponding to the at least two front-end lens groups one by one, the guide surfaces guide the outgoing light beams of the corresponding front-end lens groups to be emitted from the rear-end lens group. The projection display system can realize a high-resolution display picture and obtain a better resolution effect.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of projection display, and more particularly, relates to a projection display system. BACKGROUND

[0002] Increasing the resolution of a projection display image can effectively improve the display effect. Since the resolution of projection is restricted by the resolution of a spatial light modulator, the resolution of a single spatial light modulator is limited, and too high a resolution will result in a sharp increase in the manufacturing difficulty of the spatial light modulator and an increase in the cost.

[0003] In addition to directly using the resolution of the spatial light modulator itself, a method of splicing multiple low-resolution images into a higher-resolution image can also be used.

[0004] However, the current splicing method of multiple low-resolution images has the problem of poor display effect. SUMMARY

[0005] The purpose of the present application includes, for example, providing a projection display system to achieve high-resolution display of images.

[0006] Embodiments of the present application provide a projection display system, comprising a lens, at least two spatial light modulators, and a light combining device; the lens comprises a rear lens group and at least two front lens groups, the at least two front lens groups correspond one-to-one to the at least two spatial light modulators, so that the at least two spatial light modulators emit modulated light beams after modulation to the at least two front lens groups, and the at least two front lens groups are respectively located on both sides of the aperture stop position of the lens; the light combining device is arranged at the aperture stop position of the lens and comprises guide surfaces corresponding one-to-one to the at least two front lens groups, the guide surfaces guide the emitted light beams of the corresponding front lens groups to be emitted from the rear lens group; the front light paths of the rear lens group are combined into one path at the aperture stop of the lens, the at least two front lens groups are respectively arranged in the at least two front light paths of the rear lens group, each spatial light modulator is located in the front light path of the corresponding front lens group, and the light combining device is used to combine and guide the modulated light beams emitted by the at least two spatial light modulators to be emitted by the rear lens group.

[0007] Further, the light combining device comprises opposite bottom and top ends, the guide surfaces gradually converge from the bottom end to the top end and intersect at the top end, and when the modulated light beams emitted by the front lens groups are reflected by the guide surfaces, the position of the reflected light beams located at the edge on the guide surfaces has a spacing from the top end of the light combining device.

[0008] Further, the front lens groups are two, the light combining device is a triangular prism, the guide surfaces are two adjacent side surfaces corresponding one-to-one to the front lens groups, and the top end is a prism formed by the intersection of the two guide surfaces.

[0009] Further, the front lens group is four, the light combiner is a four-sided pyramid, the guide surface is four side surfaces corresponding to the front lens group and connected in sequence, and the top end is a vertex formed by the intersection of the four guide surfaces.

[0010] Further, the modulation light beams emitted by the at least two spatial light modulators have an inclination angle with respect to the optical axis of the corresponding front lens group, so that the light beams emitted after sequentially passing through the at least two spatial light modulators and the corresponding front lens group do not overlap at the top end position of the light combiner.

[0011] Further, the modulation light beams are inclined towards the side away from the rear lens group with respect to the optical axis of the front lens group.

[0012] Further, the guide surface is a reflective surface.

[0013] Further, the optical axes of the front lens groups located on both sides of the aperture stop position of the lens coincide.

[0014] Further, the corresponding spatial light modulator, front lens group and guide surface form a light processing group; in the same light processing group, the light beams passing through the spatial light modulator and the front lens group in sequence are reflected by the guide surface to form a picture in the rear lens group; the picture formed by any light processing group in the rear lens group has an overlap with the picture formed by the adjacent light processing group in the rear lens group.

[0015] Further, the light processing group is four groups, and the four front lens groups are located on the circumference of the light combiner, and the four spatial light modulators are arranged one-to-one in the front light path of the four front lens groups.

[0016] Further, the guide surface is the four side surfaces of the light combiner, and the picture formed by any light processing group in the rear lens group has an overlap with the picture formed by the adjacent two light processing groups in the rear lens group.

[0017] Further, the light combiner is a tower-shaped reflector.

[0018] Further, the spatial light modulator is a DMD, LCD or LCOS.

[0019] The projection display system provided by the embodiment of the present application is characterized in that a light combination device is arranged at the aperture stop position of the lens. At least two spatial light modulators are arranged in the front light path of the lens, and the at least two spatial light modulators are in one-to-one correspondence with at least two front lens groups. The modulated light beams emitted by the at least two spatial light modulators are combined by the light combination device at the aperture stop position of the lens and then emitted to the rear lens group, thereby realizing the splicing of multiple modulated images.

[0020] The incident light beams are modulated by different spatial light modulators and then emitted to the corresponding front lens groups. The emitted light beams passing through the front lens groups are emitted to different guide surfaces of the light combination device. The light combination device at the aperture stop position of the lens combines the light beams and realizes the splicing of the at least two image light beams, thereby realizing high-resolution display and improving the display effect and the refresh rate and color bit depth.

[0021] The size of the aperture stop of the lens can be adjusted by the parameter design of the lens, so that the aperture stop is smaller than the spatial light modulator. That is, without changing the size of the image formed by the spatial light modulator and the rear lens group, the structure size of the light combination device and the lens is reduced by reducing the light combination area, which is beneficial to reducing the overall volume. In addition, the optical system shares a set of rear lens group, which is convenient to use and can avoid repeated development, thereby reducing the cost. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0023] Figure 1 The schematic diagram of the projection display system provided by an embodiment of the present application for image splicing;

[0024] Figure 2 The schematic diagram of a single spatial light modulator projection for generating an image provided by an embodiment of the present application;

[0025] Figure 3 The schematic diagram of the light combination device in the projection display system provided by an embodiment of the present application;

[0026] Figure 4 The structural schematic diagram of the light combination device in the projection display system provided by an embodiment of the present application, which is a triangular prism;

[0027] Figure 5 The structural schematic diagram of the light combination device in the projection display system provided by an embodiment of the present application, which is a quadrangular pyramid;

[0028] Figure 6 A schematic diagram of picture splicing produced by projection of two spatial light modulators according to an embodiment of the present application;

[0029] Figure 7 A light beam schematic diagram of picture produced by projection of two spatial light modulators according to an embodiment of the present application;

[0030] Figure 8 A structure schematic diagram of four spatial light modulators corresponding to a light combining device according to an embodiment of the present application;

[0031] Figure 9 A schematic diagram of picture splicing produced by projection of four spatial light modulators according to an embodiment of the present application;

[0032] Figure 10 A schematic diagram of picture splicing produced by projection when the spatial light modulator is a DMD according to an embodiment of the present application;

[0033] Figure 11 A schematic diagram of picture splicing produced by projection when the spatial light modulator is a LCOS according to an embodiment of the present application. DETAILED DESCRIPTION

[0034] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described below in connection with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings can be arranged and designed in various different configurations.

[0035] It should be noted that the features in the embodiments of the present application can be combined with each other without conflict.

[0036] The projection display effect can be effectively improved by improving the resolution of the projection display picture. The resolution of the projection display picture can be improved by the following three methods.

[0037] Firstly, the resolution of the spatial light modulator itself is improved. Since the resolution of a single spatial light modulator is limited, if a too high resolution is used, the manufacturing difficulty of the spatial light modulator will be sharply increased, and the cost will also be greatly increased.

[0038] Second, the resolution of the projection display picture is improved through an XPR (Extended Pixel Resolution) device. According to the high refresh rate characteristics of the spatial light modulator, a time division multiplexing method is used to display different contents in different picture frames, and then the XPR device is used to slightly shift the image (commonly by half a projection pixel size), and finally the pictures of different frames are spliced to obtain an equivalent higher resolution image.

[0039] For example, using a native 1080p DMD, driven to 240Hz display, every 4 frames is a cycle, and every frame is displayed with a half-pixel shift, which can achieve the effect of 4K display.

[0040] However, due to the overlap between pixels when the picture is superimposed, the final picture effect is inferior to that of the native 4K picture.

[0041] Third, the picture splicing method is used. A method of splicing a high-resolution image from multiple low-resolution images is used.

[0042] For example, back projection wall is one of them. Using multiple back projection modules directly spliced together can get larger and higher resolution display. Since multiple back projection modules are directly superimposed, there will be gaps between pictures due to splicing, which affects the display effect. Of course, the scheme of overlapping splicing of projection pictures can be used, and the digital correction method can be used to correct the overlapping area, so that the picture is continuously transitioned without display gaps.

[0043] However, this scheme often requires multiple projectors to work together, and has high requirements for the relative placement position between the projectors, which makes it inconvenient to use.

[0044] In addition, the inventors have found that multiple spatial light modulators can be spliced. This method requires that the pictures overlap each other to avoid gaps, and can resist the thermal deformation effect of the machine. However, since the actual devices cannot interfere with each other, it is difficult to overlap multiple spatial light modulators themselves.

[0045] Based on the above problems, please refer to Figure 1 The embodiment of the present application provides a projection display system 100.

[0046] The projection display system 100 illuminates the plurality of spatial light modulators 120 (here, the plurality refers to two or more) by an incident light beam, modulates the modulated light beams 141 emitted by the spatial light modulators 120, and causes the modulated light beams 141 to be incident on the front lens group 113 of the lens 110. The light beams emitted by the front lens group 113 are caused to pass through the light combining device 130 positioned at the aperture stop 115 of the lens 110, so that the light beams pass through the light combining device 130, are reflected by the light combining device 130, and are incident on the rear lens group 111 of the lens 110. Thus, the light combining device 130 combines the modulated light beams 141 emitted by the plurality of spatial light modulators 120 and guides the modulated light beams 141 to be emitted by the rear lens group 111, so that the at least two image light beams are overlapped with each other to form a picture. This is advantageous to obtain a high-resolution image, and the optical system is emitted by a single lens, which is convenient to use and effectively improves the resolution effect without reducing the refresh rate and color bit depth.

[0047] Specifically, the projection display system 100 provided by the embodiment of the present application includes a lens 110, at least two spatial light modulators 120, and a light combining device 130.

[0048] The lens 110 includes a rear lens group 111 and at least two front lens groups 113. The at least two front lens groups 113 are respectively positioned on both sides of the aperture stop 115 of the lens 110 and correspond to the at least two spatial light modulators 120 one by one. The light combining device 130 is arranged at the aperture stop 115 of the lens 110 and includes a guide surface 131 corresponding to the at least two front lens groups 113 one by one.

[0049] The incident light beam is incident on the at least two spatial light modulators 120, and the modulated light beams 141 modulated by the spatial light modulators 120 are emitted to the front lens group 113 corresponding to the spatial light modulators 120. The modulated light beams 141 pass through the front lens group 113, are emitted to the guide surface 131 of the light combining device 130 corresponding to the front lens group 113, pass through the light combining device 130, and are guided to be emitted by the rear lens group 111 of the lens 110, so as to form an imaging light path.

[0050] That is, the front lens group 113 is positioned in the front light path of the rear lens group 111, the light combining device 130 is positioned in the light path between the front lens group 113 and the rear lens group 111 and at the aperture stop 115 of the lens 110, and the spatial light modulator 120 is positioned in the front light path of the front lens group 113. The front light path can be understood as a position where a light beam first passes through is the front end, and a position where the same light beam passes through later is the rear end.

[0051] The front optical path of the rear lens group 111 is combined from at least two paths at the aperture stop 115 of the lens 110. At least two front lens groups 113 are respectively disposed in the at least two front optical paths of the rear lens group 111, and each spatial light modulator 120 is located in the front optical path of its corresponding front lens group 113. The projection display system 100 combines the modulated beams 141 emitted from at least two spatial light modulators 120 through a light combining device 130 and guides them to the rear lens group 111 of the lens 110 for emission, thereby realizing the splicing of the projected image.

[0052] The projection display system 100 provided in this application embodiment employs multiple spatial light modulators 120 to position the light combining device 130 at the aperture stop 115 of the lens 110. This achieves a high-resolution display image, obtains better resolution, has a high refresh rate and color bit depth, and avoids the actual sharp edges of the light combining device 130 affecting the image during light combining.

[0053] First, the working principle will be introduced by taking the projection of a single spatial light modulator 120 as an example.

[0054] For details, please refer to Figure 2 As shown, the lens 110 includes a front lens group 113 and a rear lens group 111. A spatial light modulator 120 is disposed in the front optical path of the lens 110. The incident light beam is modulated by the spatial light modulator 120 and then output as a modulated light beam 141. The modulated light beam 141 passes through the front lens group 113 and the rear lens group 111 of the lens 110 in sequence and is output, finally forming a projected image 140 in the rear optical path of the lens 110.

[0055] The front lens group 113 can be a single lens or a combination of multiple lenses. The aperture stop 115 of the lens 110 is located between the front lens group 113 and the rear lens group 111. From the position of the spatial light modulator 120 to the position of the aperture stop 115 of the lens 110, after the image formed by the spatial light modulator 120 is transformed, the brightness distribution of light at different positions of the spatial light modulator 120 becomes the brightness distribution of light at different angles at the position of the aperture stop 115 of the lens 110, which is equivalent to a transformation from a planar distribution to an angular distribution.

[0056] Since the position and area covered by the light beam at the aperture stop 115 are determined by the angular distribution of the image generated by the spatial light modulator 120, and the position of the spatial light modulator 120 corresponds to the angular distribution at the aperture stop 115, the position of the final projected image 140 is determined by the position of the spatial light modulator 120. By setting an offset for the spatial light modulator 120, the projected image 140 of a single spatial light modulator is offset relative to the center of the lens 110.

[0057] According to the working principle of the single spatial light modulator 120 for projecting to generate a picture, the projection display system 100 provided by the embodiment of the present application is described in detail below.

[0058] Please continue to refer to Figure 1 As shown in the figure, the lens 110 includes a rear end lens group 111 and at least two front end lens groups 113. Among them, the front end lens group 113 can be a single lens, or a combination of multiple lenses. The at least two front end lens groups 113 are the same lens or lens group. The rear end lens group 111 can also be a single lens, or a combination of multiple lenses, which is determined according to the actual imaging requirements.

[0059] The exit light beams (at least two light beams) of the at least two front end lens groups 113 pass through the light combining device 130 at the aperture stop 115 position of the lens 110 to combine light into a light beam incident to the rear end lens group 111. That is, the front end light path of the rear end lens group 111 can include at least two light beam branches emitted by the at least two front end lens groups 113, and a light beam combined after passing through the light combining device 130 at the aperture stop 115 position of the lens 110. The at least two front end lens groups 113 are respectively arranged in the at least two front end light paths of the rear end lens group 111, that is, the at least two front end lens groups 113 are respectively arranged in the at least two light beam branches in a one-to-one correspondence, and the at least two front end lens groups 113 are respectively located on both sides of the aperture stop 115 position of the lens 110.

[0060] For example, as Figure 1 shown, when the number of front end lens groups 113 is two, the front end light path of the rear end lens group 111 includes two light beam branches emitted by the two front end lens groups 113 respectively, and a light beam combined after the two light beam branches pass through the light combining device 130 at the aperture stop 115 position. The two front end lens groups 113 are respectively located in the two light beam branches, and are respectively located on both sides of the aperture stop 115 position of the lens 110 (here, both sides can be understood as a plane passing through the center axis of the rear end lens group 111 and perpendicular to the center axis of the two front end lens groups 113, the plane is perpendicular to the aperture stop 115 position of the lens 110, and the two front end lens groups 113 are symmetric about the plane).

[0061] When the number of the front lens groups 113 is four, the front light path of the rear lens group 111 includes four light beam branches respectively emitted by the four front lens groups 113 and a light path formed by the four light beam branches after being reflected by the light combination device 130 located at the aperture stop 115 of the lens 110. The four front lens groups 113 are respectively located in the four light beam branches and are respectively located at the circumferential direction of the aperture stop 115 of the lens 110. The four front lens groups 113 are divided into two groups, two front lens groups 113 in the same group are oppositely arranged, and the two front lens groups 113 in the same group are respectively located at two sides of the aperture stop 115 of the lens 110. The central axes of the front lens groups 113 in different groups have an included angle, and in an optional embodiment, the four front lens groups 113 are uniformly arranged around the central axis of the rear lens group 111.

[0062] Further, the light combination device 130 is arranged at the aperture stop 115 of the lens 110. The light combination device 130 includes guide surfaces 131 corresponding to the number of the front lens groups 113 of the lens 110. The corresponding relationship between the front lens group 113 and the guide surface 131 of the light combination device 130 is one-to-one. The light beams passing through the corresponding front lens group 113 are folded by the different guide surfaces 131, so as to combine the different light beam branches into a light path, and then the light beam is projected by the rear lens group 111 to realize the picture splicing of the at least two spatial light modulators 120. Further, the spatial light modulator 120 is arranged in the front light path of each front lens group 113, so that the spatial light modulator 120 corresponds to the front lens group 113 one-to-one, and further corresponds to the guide surface 131 of the light combination device 130 one-to-one.

[0063] Further, the optical axes of the front lens groups 113 located at both sides of the aperture stop 115 of the lens 110 coincide.

[0064] When the number of the front lens groups 113 is two, the number of the spatial light modulators 120 is also two. The two front lens groups 113 are respectively located at both sides of the aperture stop 115, and the optical axes of the two front lens groups 113 coincide.

[0065] When the number of the front lens groups 113 is more than two, the number of the spatial light modulators 120 is also more than two and is the same as the number of the front lens groups 113. The front lens groups 113 are respectively located at the circumferential direction of the aperture stop 115 position, the optical axes of all the front lens groups 113 are located on the same plane, and the plane is parallel to or coincides with the plane where the aperture stop 115 of the lens 110 is located. For example, the number of the front lens groups 113 is four, and the number of the spatial light modulators 120 is also four. The four front lens groups 113 are respectively located at the circumferential direction of the aperture stop 115 position, and the optical axes of the four front lens groups 113 are located on the same plane. When the four front lens groups 113 are opposite to each other, the corresponding two front lens groups 113 are located on both sides of the aperture stop 115 position, and the optical axes of the corresponding two front lens groups 113 coincide. The optical axes of the four front lens groups 113 are all located on the same plane which is parallel to or coincides with the plane where the aperture stop 115 is located.

[0066] Please refer to Figure 3 The light combination device 130 includes opposite bottom end 135 and top end 133, and the guide surface 131 gradually approaches from the bottom end 135 to the top end 133 and intersects at the top end 133 position, wherein the top end 133 position is located at the aperture stop position of the lens 110.

[0067] When the number of the front lens groups 113 is two, the light combination device 130 is a three-prism structure (as shown in Figure 4 The guide surface 131 of the light combination device 130 is two sides of the three-prism, and the two sides correspond to the two front lens groups one by one, and the top end 133 is the edge formed by the intersection of the two sides.

[0068] When the number of the front lens groups 113 is four, the light combination device 130 is a four-prism structure (as shown in Figure 5 The guide surface 131 of the light combination device 130 is four sides of the four-prism, and the four sides correspond to the four front lens groups one by one, and the top end 133 is the vertex formed by the intersection of the four sides.

[0069] Please continue to refer to Figure 1 The modulated light beams 141 emitted from the spatial light modulator 120 after modulation are emitted from the front lens groups 113 to the corresponding guide surface 131, and when reflected to the rear lens group 111 through the guide surface 131, the position of the reflected light beams at the edge on the guide surface 131 has a spacing between the top end 133 of the light combination device 130. Wherein, the reflected light beams at the edge here refer to the edge light beams close to the top end 133 of the light combination device 130.

[0070] The light beam distribution at the aperture stop 115 of the lens 110 is related to the angular distribution of the picture generated by the spatial light modulator 120 corresponding to the aperture stop 115. The light beam at the edge can be designed to be offset from the top end 133 of the light combiner 130 by designing the illumination light beam of the spatial light modulator 120. Thus, the pictures generated by the at least two spatial light modulators 120 will not be joined together by the light combiner 130 to form a picture with a joint gap due to the manufacturing tolerance of the top end 133 of the light combiner 130.

[0071] Please refer to Figure 6 Figure 6 The picture joining diagram of the modulated pictures formed in the rear end lens group 111 after the two spatial light modulators (121, 123) pass through the corresponding front end lens group (1130, 1132) and the two guide surfaces (1310, 1312) of the light combiner 130. In the projection display system 100 provided by the embodiment of the present application, the modulated light beam 141 emitted by the at least two spatial light modulators (121, 123) has an inclination angle with respect to the central axis of the corresponding front end lens group (1130, 1132).

[0072] Specifically, please refer to Figure 7 When the number of the spatial light modulators 120 is two, the two spatial light modulators 120 are arranged in the front end light path of the two front end lens groups 113 of the lens 110. The optical axis of the front end lens group 113 is the first optical axis 1134, and the optical axis of the rear end lens group 111 is the second optical axis 1118. The modulated light beam 141 emitted by the spatial light modulator 120 after modulation is incident on the corresponding front end lens group 113, and the modulated light beam 141 has an inclination angle with respect to the first optical axis 1134. Thus, the light beams emitted after sequentially passing through the two spatial light modulators 120 and the corresponding front end lens groups 113 will not be overlapped at the top end 133 of the light combiner 130 when reflected on the guide surface 131 of the light combiner 130. Thus, the modulated light beams 141 emitted by the two spatial light modulators 120 will be completely separated at the aperture stop of the lens 110.

[0073] Further, the direction of the modulated light beam 141 emitted after passing through the spatial light modulator 120 is inclined towards the side away from the rear end lens group 111 with respect to the optical axis (the first optical axis 1134) of the corresponding front end lens group 113. The direction of the emitted light beam 143 is different after sequentially passing through different spatial light modulators 120, front end lens groups 113 and different guide surfaces 131 of the light combiner 130.

[0074] ​With the second optical axis 1118 (the optical axis of the rear lens group 111) as a reference, the direction of the outgoing beam 143 corresponding to different incident beams is away from the second optical axis 1118. Figure 7 (represented by two different forms of dashed lines in the middle), the tilt angle of the incident beam must satisfy that the outgoing beam 143 after passing through different spatial light modulators 120 and front lens group 113 does not overlap.

[0075] Please continue to refer to Figure 6 As shown, the light combining device 130 is positioned at the angular distribution position of the stitched image formed in the rear lens group 111, i.e., at the aperture stop 115 position of the lens 110. The aperture stop 115 position of the lens 110 is as follows: Figure 2 As shown, this plane is parallel to the plane containing the stitched image formed in the rear lens group 111. Since the guide surfaces (1310, 1312) of the beam combiner 130 are tilted relative to the angular distribution position of the stitched image, the guide surfaces of the beam combiner 130 cannot coincide with the plane containing the angular distribution position of the stitched image. As described above, the light beam incident on the guide surface 131 must be completely offset from the top end 133 of the beam combiner 130; therefore, the top end 133 of the beam combiner 130 is positioned near the aperture stop 115 of the lens 110.

[0076] Preferably, the top end 133 of the light combining device 130 is located at the center of the aperture stop 115 of the lens 110, wherein the center of the aperture stop 115 refers to the intersection of the optical axis of the rear lens group 111 and the aperture stop 115.

[0077] Light rays perpendicular to the plane of the stitched image will converge at the center of the aperture stop 115, i.e., at the top 133 of the light combining device 130. Figure 6 From a certain perspective, if light rays are tilted to the left, they will converge to the left of the center of aperture stop 115; if light rays are tilted to the right, they will converge to the right of the center of aperture stop 115. Here, tilting to the left and tilting to the right means that the angle of incidence of the light rays is opposite to the optical axis of the rear lens group 111.

[0078] Figure 6In the embodiment, the two spatial light modulators 120 include a first modulator 121 and a second modulator 123, the first modulator 121 generates a first image 1110 through a first front lens group 1130 and a first guide surface 1310, and the second modulator 123 generates a second image 1112 through a second front lens group 1132 and a second guide surface 1312. The top end 133 of the light combiner 130 is placed at the center of the aperture stop 115 of the lens 110, an angle-tilted illumination beam is used for the first modulator 121 so that the light rays of the formed first image 1110 are all tilted to the left of the center of the aperture stop 115, and an angle-tilted illumination beam in the opposite direction is used for the second modulator 123 so that the light rays of the formed second image 1112 are all tilted to the right of the center of the aperture stop 115. At the position of the aperture stop 115 of the lens 110, the light rays corresponding to the first image 1110 and the second image 1112 are completely separated.

[0079] The different angle of incident light is used to illuminate the different spatial light modulators 120, and the light rays are emitted from the spatial light modulators 120 and the front lens group 113 to the different guide surfaces 131 of the light combiner 130, so as to be separated at the light combiner 130, regardless of the overlapping between the multiple images, and the degree of image splicing is not limited. Therefore, the overlapping between the multiple images can be set arbitrarily on the premise that the incident light rays are sufficiently separated.

[0080] In other words, when the pictures formed by the at least two spatial light modulators 120 are spliced through the light combiner 130, the light beams emitted by the spatial light modulators 120 cannot overlap with each other at the light combiner 130. When the light beams overlap with each other, the picture will have display failure such as gaps and dark lines due to energy loss, so that effective light combination cannot be performed. In addition, due to the position of the top end 133 of the light combiner 130, there will be some edge collapse problems in actual manufacturing, and thus the region of the top end 133 cannot be used.

[0081] The position of the spliced picture out of the rear lens group 111 depends on the position of the spatial light modulator 120. Optionally, the position of the picture formed by each spatial light modulator 120 can be controlled by shifting the spatial light modulator 120 to produce an offset, and the pictures formed by the plurality of spatial light modulators 120 are overlapped. The position of the spliced picture can also be adjusted by controlling the angle of the directing surface 131 in the light combiner 130. Since the light combiner 130 is located at the position of the aperture stop 115 of the lens 110, it is equivalent to rotating the whole of the spatial light modulator 120 and the front lens group 113 around the directing surface 131, that is, to deflect the angle of the light at the aperture stop 115 of the lens 110. According to the angle of the light at the aperture stop 115 corresponding to different positions of the image formed by the rear lens group 110, when the angle of the directing surface 131 in the light combiner 130 is changed, the position of the picture in the rear lens group 111 is also changed.

[0082] When the plurality of spatial light modulators 120 are used to splice pictures, the position and angle of each spatial light modulator 120 relative to the corresponding directing surface 131 need to be set according to the form of picture splicing.

[0083] For example, referring to Figure 8 and Figure 9 , four spatial light modulators 120 are used to splice pictures through the light combiner 130 with a four-prism structure (wherein a front lens group is arranged between each spatial light modulator 120 and the corresponding directing surface 131, Figure 8 and the front lens group and the rear lens group are not shown).

[0084] When the four spatial light modulators 120 are at the position and angle shown in Figure 8 , the pictures formed by the four spatial light modulators 120 in the rear lens group 111 are in the splicing form shown in Figure 9 .

[0085] Specifically, the four spatial light modulators 120 are a first modulator 121, a second modulator 123, a third modulator 125, and a fourth modulator 127, which correspond to form a first image 1110, a second image 1112, a third image 1114, and a fourth image 1116 in the rear lens group 111 of the lens 110. The picture formed by any spatial light modulator 120 in the rear lens group 111 has an overlapping part with the pictures formed by the two spatial light modulators 120 adjacent to it in the rear lens group 111. Optionally, a picture without joint can be formed by digital correction.

[0086] It is understood that the above examples illustrate image stitching using two spatial light modulators 120 and four spatial light modulators 120. The embodiments of this application are not limited to the number of spatial light modulators 120, as long as the number of spatial light modulators 120 is two or more, depending on actual usage requirements. The structure of the light combining device 130 is not required, as long as it reflects and combines the light from multiple spatial light modulators 120 through multiple guide surfaces 131 and projects it into the rear lens group 111.

[0087] In this application, the guiding surfaces 131 of the corresponding spatial light modulator 120, front lens group 113, and light combining device 130 form a light processing group. In the same light processing group, the light beams that pass through the spatial light modulator 120 and the front lens group 113 in sequence are reflected by the guiding surface 131 and form an image in the rear lens group 111.

[0088] Furthermore, the image formed by any light processing group in the rear lens group 111 overlaps with the image formed by its adjacent light processing group in the rear lens group 111.

[0089] The guiding surfaces 131 are the four sides of the light combining device 130, and corresponding to them, there are four light processing groups. The four front lens groups 113 are located around the light combining device 130 and correspond one-to-one with the four guiding surfaces 131. At the same time, the four spatial light modulators 120 are also correspondingly arranged in the front optical path of the four front lens groups 113.

[0090] Furthermore, the light combining device 130 is a tower-shaped reflector. The tower-shaped reflector includes a base and a top, and has a converging structure from the base to the top.

[0091] Specifically, the tower-shaped reflector includes a bottom surface at the base of the tower and a side surface connecting the base and the top of the tower. The bottom surface is polygonal, with the same number of sides as the side surfaces. From the base to the top of the tower, the side surfaces gradually taper and converge, intersecting at the top. The converging side surfaces form the guiding surface 131 of the light combining device 130.

[0092] For example, such as Figure 4 As shown, when there are two spatial light modulators 120, the tower-shaped reflector is a triangular prism structure. The triangular prism includes two parallel planes and three intersecting side surfaces. One side surface is the bottom surface of the tower base, and the other two side surfaces gradually converge and intersect from the bottom to the top of the tower. These two side surfaces are the guiding surfaces 131 of the light combining device 130, and the edge formed by the intersection of the two guiding surfaces 131 is the top edge 133.

[0093] like Figure 5As shown, when the number of spatial light modulators 120 is four, the tower mirror is a four-prism structure. The four-prism includes a bottom surface and four side surfaces connected to the four edges of the bottom surface, respectively. The four side surfaces gradually converge from the bottom of the tower to the top of the tower and meet at a point at the top of the tower, which is the top end 133 of the light combining device 130. The guide surface 131 is the four side surfaces of the four-prism. In the projection display system 100 of this structure, the picture formed by any light processing group and its adjacent two light processing groups in the rear end lens group 111 has an overlap.

[0094] After the multiple light beam branches formed by the multiple spatial light modulators 120 are combined at the light combining device 130, they converge into one light beam. That is, in the front end optical path of the rear end lens group 111, there will be a light beam formed by multiple light spots spliced together. The rear end lens group 111 of the lens 110 will simultaneously receive light from multiple light spots, so when designing the rear end lens group 111, it is necessary to ensure that the aperture of the rear end lens group 111 is large enough to accept the light from all the light spots, with sufficient margin.

[0095] Optionally, the spatial light modulator 120 can be, but is not limited to, a DMD (Digital Micromirror Device), an LCOS (Liquid Crystal on Silicon), an LCD (Liquid Crystal Display), etc. Hereinafter, the DMD and the LCOS are taken as examples for illustration.

[0096] Specifically, please refer to Figure 10 As shown, Figure 10 is a schematic diagram of image splicing for two DMDs. The light combining device 130 is a tower mirror, and the rear end lens group is not shown. A TIR prism 128 device cooperating with the DMD is arranged between each front end lens group 113 and the corresponding DMD. The front end lens group 113 is used to refract the picture light beam of the corresponding DMD, and the refracted light beam is combined at the light combining device 130.

[0097] Please refer to Figure 11 As shown, Figure 11 is a schematic diagram of image splicing for two LCOSs. The light combining device 130 is a tower mirror, and the rear end lens group is not shown. A PBS prism 129 device cooperating with the LCOS is arranged between each front end lens group 113 and the corresponding LCOS. The front end lens group 113 is used to refract the picture light beam of the corresponding LCOS, and the refracted light beam is combined at the light combining device 130.

[0098] It can be understood that the above examples two spatial light modulators 120 (DMD and LCOS) for picture splicing embodiment, the embodiments of the present application are not limited to the above two, according to the actual use requirements.

[0099] The projection display system 100 provided by the embodiments of the present application adopts at least two spatial light modulators 120, and the light combiner 130 is arranged at the aperture stop 115 of the lens 110, so that the at least two spatial light modulators 120 perform light combination at the aperture stop 115 of the lens 110, thereby splicing multiple pictures.

[0100] The optical system can separate the illumination angle of each spatial light modulator 120 to avoid the influence of the top end 133 of the light combiner 130 on the picture during light combination, and is not prone to interference between the multiple spatial light modulators 120. High-resolution display pictures are realized, the display effect is improved, the refresh rate and the color bit depth are higher, a set of rear lens group 111 is shared, repeated development is avoided, and the cost is reduced.

[0101] In addition, the size of the aperture stop 115 of the lens 110 can be adjusted by the parameter design of the lens 110, so that the aperture stop 115 smaller than the spatial light modulator can be obtained. That is to say, without changing the image size formed by the spatial light modulator 120 and the rear lens group 111, the structure size of the light combiner 130 and the lens 110 is reduced by reducing the light combination area, and the overall volume of the optical system is reduced.

[0102] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not drive the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A projection display system, characterized by comprising: The application relates to a lens system, comprising: at least two spatial light modulators; a lens, which comprises a rear lens group and at least two front lens groups corresponding to the at least two spatial light modulators, so that the at least two spatial light modulators emit modulated light beams to the at least two front lens groups, and the at least two front lens groups are respectively located on both sides of an aperture stop position of the lens; and a light combiner, which is arranged at the aperture stop position of the lens and comprises guide surfaces corresponding to the at least two front lens groups, the guide surfaces guiding the light beams emitted by the corresponding front lens groups to be emitted from the rear lens group, the light combiner comprising opposite bottom and top ends, the guide surfaces gradually converging from the bottom end to the top end and intersecting at the top end; the modulated light beams emitted by the at least two spatial light modulators have an inclination angle with the optical axes of the corresponding front lens groups, so that the light beams sequentially passing through the at least two spatial light modulators and the corresponding front lens groups do not overlap at the top end of the light combiner; the front light paths of the rear lens group are combined into one path at the aperture stop of the lens, the at least two front lens groups are respectively arranged in the at least two front light paths of the rear lens group, each spatial light modulator is located in the front light path of the corresponding front lens group, and the light combiner is used for combining and guiding the modulated light beams emitted by the at least two spatial light modulators to be emitted by the rear lens group; wherein the size of the aperture stop of the lens is smaller than the size of the spatial light modulator, so as to reduce the structural size of the light combiner and the lens without changing the image size formed by the spatial light modulator and the rear lens group.

2. The projection display system of claim 1, wherein, When the modulated light beams emitted by the front lens groups are reflected by the guide surfaces, the positions of the reflected light beams on the guide surfaces and the top end of the light combiner have a spacing.

3. The projection display system of claim 2, wherein, The front lens groups are two, the light combiner is a triangular prism, the guide surfaces are two side surfaces corresponding to the front lens groups and adjacent to each other, and the top end is a vertex formed by the intersection of the two guide surfaces.

4. The projection display system of claim 2, wherein The front lens groups are four, the light combiner is a quadrangular pyramid, the guide surfaces are four side surfaces corresponding to the front lens groups and sequentially connected to each other, and the top end is a vertex formed by the intersection of the four guide surfaces.

5. The projection display system of claim 1, wherein, The modulated light beams are inclined to the side away from the rear lens group relative to the optical axes of the front lens groups.

6. The projection display system of any of claims 1-5, wherein, The guide surfaces are reflective surfaces.

7. The projection display system of claim 1, wherein The optical axes of the front lens groups located on both sides of the aperture stop of the lens coincide.

8. The projection display system of claim 1, wherein, The corresponding spatial light modulator, front lens group and guide surface form a light processing group; in the same light processing group, the light beams sequentially passing through the spatial light modulator and the front lens group are reflected by the guide surface, and a picture is formed in the rear lens group. The picture formed by any one of the light processing groups in the rear-end lens group has an overlap with the picture formed by its adjacent light processing group in the rear-end lens group.

9. The projection display system of claim 8, wherein, The light processing groups are four groups, and the four front-end lens groups are respectively located in the circumferential direction of the light combining device.

10. The projection display system of claim 9, wherein, The guiding surfaces are four side surfaces of the light combining device, and the picture formed by any one of the light processing groups in the rear-end lens group has an overlap with the picture formed by its adjacent two light processing groups in the rear-end lens group.

11. The projection display system of claim 1, wherein, The light combining device is a tower-shaped mirror.

12. The projection display system of any of claims 1-5, 7-11, wherein, The spatial light modulator is a DMD, an LCD or an LCOS.

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