A holographic display system

Abstract

The utility model discloses a holographic display system, holographic display system includes: backlight, is used to produce the light beam feature adjustable light source light, pixelated holographic structure is located on the emergent light path of light source light, includes a plurality of holographic structure unit group, and each holographic structure unit group converges the light source light on the incidence on it to a corresponding target view point, when the different light source light of backlight emission is incident to pixelated holographic structure in time, pixelated holographic structure is used for modulating light source light as the light field converging to the corresponding target view point group, and the target view point group includes a plurality of target view points corresponding to a plurality of holographic structure unit group formation. The utility model discloses through adjusting the light beam feature of light source light incident to pixelated holographic structure to change the directivity of diffracted light, thereby can realize multiple view point groups through changing the view point number and view point position of holographic backlight, makes holographic display system have view point variable and view point expandable function.

Description

Technical Field

[0001] This utility model relates to the field of 3D display technology, and in particular to a holographic display system. Background Technology

[0002] 3D display systems based on pixelated directional backlights have significant practical value and application prospects. The principle involves using pixelated diffraction units to deflect light from the source to different viewpoints, thereby, in conjunction with image-enhancing elements (film masks, LCD screens, etc.), to present images of objects from different perspectives. 3D displays based on multi-viewpoint parallax barrier schemes or cylindrical lens array schemes have already been applied in many scenarios.

[0003] In recent years, directional backlight technology based on pixelated diffractive elements has provided a new technical approach for multi-viewpoint displays. Its core is to use pixelated diffractive elements to divide the collimated backlight into directional backlights pointing to multiple viewpoints, and then combine this with imaging elements to modulate image information from different viewpoints, thereby achieving multi-viewpoint displays. Compared to parallax barrier solutions or cylindrical lens array solutions, directional backlight solutions have advantages such as high luminous efficiency, low crosstalk between viewpoints, and ease of implementing more viewpoints. Generally speaking, once the pixelated diffractive elements are fabricated, the number and positions of the viewpoints that the corresponding display system can achieve are fixed.

[0004] Therefore, existing technologies still need to be improved and developed. Utility Model Content

[0005] In view of the shortcomings of the prior art, the purpose of this utility model is to provide a holographic display system to solve the problem that the number and position of viewpoints that can be achieved in the existing directional backlight technology based on pixelated diffraction elements cannot be adjusted.

[0006] The technical solution of this utility model is as follows: A holographic display system comprising: A backlight source, wherein the backlight source is used to generate light source light with adjustable beam characteristics; A pixelated holographic structure is located on the outgoing light path of the light source. The pixelated holographic structure includes multiple holographic structure unit groups, and each holographic structure unit group converges the light source incident on it to a corresponding target viewpoint. When different light sources emitted from the backlight are incident on the pixelated holographic structure in a time-division manner, the pixelated holographic structure is used to modulate the light source into a light field that converges to the corresponding target viewpoint group. The target viewpoint group includes multiple target viewpoints formed by multiple holographic structure unit groups.

[0007] The present invention further provides that, when each of the holographic structural unit groups converges the light incident on it to a corresponding target viewpoint, it simultaneously modulates the light incident on it into the corresponding target image light.

[0008] The present invention further includes an image element in the holographic display system. The image element is located in the outgoing light path of the pixelated holographic structure. The image element modulates the light emitted from each target viewpoint into the corresponding target image light.

[0009] The present invention further provides that the backlight source is used to emit light from light sources with different emission angles or different polarization states in a time-division manner.

[0010] The present invention further provides that the backlight includes at least two sets of laser light source components, and the at least two sets of laser light sources work alternately to output light from different emission angles in a time-division manner.

[0011] The present invention further includes a backlight source assembly and a moving component. The laser source assembly is mounted on the moving component, and the moving component drives the laser source to rotate so as to emit light from the source at different emission angles in a time-division manner.

[0012] The present invention further provides that the laser source assembly includes a laser source and an optical assembly, wherein the laser source is used to generate coherent light; the optical assembly is located in the output light path of the laser source and is used to collimate the coherent light.

[0013] The present invention further includes a backlight source comprising a uniform waveguide, wherein the uniform waveguide includes an input region and an output region. The uniform waveguide is disposed in the output optical path of the at least two laser source components. The output light from the at least two sets of laser source components is coupled into the coupling region of the uniform waveguide in a time-division manner, propagates to the coupling region of the uniform waveguide after total internal reflection, and exits from the coupling region of the uniform waveguide before being incident on the pixelated holographic structure; or, The uniform waveguide is set in the light output path of the laser source component. The light emitted from the laser source component is coupled into the coupling region of the uniform waveguide, propagates to the coupling region of the uniform waveguide after total internal reflection, and is coupled out from the coupling region of the uniform waveguide and incident on the pixelated holographic structure.

[0014] The present invention further provides that the holographic structure unit group includes multiple holographic structure units; When light from a source is incident on it, the spatial angle of the outgoing light formed by the diffraction of the light from the source by each holographic structural unit is less than 90 degrees; or, The holographic structural unit is rectangular, and the length of the holographic structural unit is 10-600 micrometers; The multiple holographic structural unit groups are interlocked in an ordered or disordered manner so that all the holographic structural units are laid out flat on the light-emitting surface of the backlight.

[0015] The present invention further provides that the arrangement of the multiple target viewpoints in the target viewpoint group formed by light sources with different incident angles is different.

[0016] This invention provides a holographic display system comprising: a backlight source for generating light with adjustable beam characteristics; and a pixelated holographic structure located on the outgoing light path of the light source, the pixelated holographic structure comprising multiple holographic structure unit groups, each of which converges the incident light source light to a corresponding target viewpoint. When different light sources emitted from the backlight source are incident on the pixelated holographic structure in a time-division manner, the pixelated holographic structure modulates the light source light into a light field converged to a corresponding target viewpoint group, the target viewpoint group comprising multiple target viewpoints corresponding to the multiple holographic structure unit groups. This invention employs a holographic structure in the pixelated diffraction device, and the holographic structure can record information from multiple light sources. By adjusting the beam characteristics of the light source incident on the pixelated holographic structure, this invention changes the directivity of the diffracted light, thereby enabling multiple viewpoint groups to be achieved by changing the number and position of the holographic backlight, thus giving the holographic display system variable and expandable viewpoint functionality. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the overall structure of the holographic display system in this utility model.

[0019] Figure 2 This is a schematic diagram of the pixelated holographic structure in this utility model.

[0020] Figure 3 This is a schematic diagram of different backlight implementation schemes in the holographic display system of this utility model.

[0021] Figure 4 This is a schematic diagram illustrating the principle of single-pixel exposure in the pixelated holographic structure fabrication scheme of this utility model.

[0022] Figure 5 This is a schematic diagram of the exposure principle of another set of pixels in the pixelated holographic structure fabrication scheme of this utility model.

[0023] Figure 6 This is a schematic diagram illustrating the principle of single-pixel multiplexing exposure in the pixelated holographic structure fabrication scheme of this utility model.

[0024] Figure 7 This is a schematic diagram illustrating the principle of using an additional pixelation mask to prepare a pixelated holographic structure in this invention.

[0025] The following labels in the attached figures are: 10, backlight; 110, laser light source; 120, optical component; 20, pixelated holographic structure; 201, functional layer; 202, first protective film layer; 203, second protective film layer; 204, first pixelated mask; 205, second pixelated mask; 30, image element. Detailed Implementation

[0026] This utility model provides a holographic display system. To make the purpose, technical solution, and effects of this utility model clearer and more explicit, the following describes this utility model in further detail with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely illustrative of this utility model and are not intended to limit this utility model.

[0027] In the implementation methods and claims, unless otherwise specified in the text, the terms "a," "an," "the," and "the" may also include plural forms. If the embodiments of this utility model involve descriptions of "first," "second," etc., such descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0028] It should be further understood that the term "comprising" as used in this specification means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. It should be understood that when an element is referred to as "connected" or "coupled" to another element, it can be directly connected or coupled to the other element, or there may be intermediate elements present. Furthermore, "connected" or "coupled" as used herein can include wireless connections or wireless coupling. The term "and / or" as used herein includes all or any of the units and all combinations thereof of one or more associatedly listed items.

[0029] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless specifically defined as herein.

[0030] Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0031] The inventors discovered that 3D display is one of the ultimate goals in the display field and has long been a hot research topic. Compared to light field display schemes that display true 3D information, multi-viewpoint display schemes are currently the easiest 3D display solutions to implement with existing technology. The principle is to present different patterns from different viewpoints, allowing the viewer's left and right eyes to see different images, which are then synthesized into 3D information in the viewer's brain. Directional backlight technology based on pixelated diffraction elements provides a new technical route for multi-viewpoint displays. In typical directional backlight multi-viewpoint display systems, the diffraction function or micro / nano morphology of each pixel is designed based on a preset viewpoint position. Therefore, generally speaking, a set of directional backlights corresponds to a fixed number and position of viewpoints. Furthermore, typical pixelated element manufacturing schemes are achieved through pixel-by-pixel step-by-step exposure, which is inefficient for high-definition displays. Simultaneously, multi-viewpoint displays rely on image-based elements.

[0032] To address the aforementioned technical problems, this invention provides a holographic display system. By adjusting the beam characteristics of the light source incident on the pixelated holographic structure, the directivity of the diffracted light can be altered, thereby changing the number and position of viewpoints in the holographic backlight. This enables the holographic display system to have variable and expandable viewpoints. Furthermore, by utilizing exposure light field design, batch exposure recording of pixelated units can be achieved, thus improving the fabrication efficiency and feasibility of the holographic structure. Moreover, by recording pattern information within the holographic structure, multi-viewpoint display is achieved without using image elements.

[0033] Please also refer to Figures 1 to 3 This utility model provides a preferred embodiment of a holographic display system.

[0034] In some embodiments, such as Figure 1 and Figure 2As shown, this utility model provides a holographic display system, comprising: a backlight 10 and a pixelated holographic structure 20. The backlight 10 is used to generate light with adjustable beam characteristics; the pixelated holographic structure 20 is located in the outgoing light path of the light source, and the pixelated holographic structure 20 includes multiple holographic structure unit groups, each of which converges the light source incident on it to a corresponding target viewpoint. When different light sources emitted from the backlight 10 are incident on the pixelated holographic structure 20 in a time-division manner, the pixelated holographic structure 20 modulates the light source into a light field that converges to the corresponding target viewpoint group, and the multiple holographic structure unit groups included in the target viewpoint group correspond to multiple target viewpoints.

[0035] In this embodiment, a hologram is an advanced photographic technique that records all the information in the light waves reflected (or transmitted) by a photographed object. The principle of holography is based on the principle of light interference, using the interference of two beams of light to record the information of the photographed object. The laser beam is split in two by a beam splitter; one beam illuminates the object being photographed and is called the object beam; the other beam illuminates directly onto the holographic plate and is called the reference beam. When the object beam is reflected by the object, its reflected beam also illuminates the film, thus completing the holographic photograph capture process.

[0036] The pixelated holographic structure 20 has multiplexing characteristics. When illuminated by light sources (backlights) with different beam characteristics, the pixelated holographic structure 20 can generate viewpoints of different numbers and positions. That is, all pixels belonging to the same viewpoint are exposed separately using reference light (light sources) with different characteristics, thereby making the corresponding area reusable. The beam characteristics include, but are not limited to, direction and polarization. The multiplexing characteristics of the pixelated holographic structure 20 are achieved based on its angle multiplexing, polarization multiplexing, wavelength multiplexing, and other multiplexing characteristics.

[0037] like Figure 1 and Figure 2 As shown, assuming the holographic display system has four viewpoints, the pixelated holographic structure 20 has four groups of holographic structure units, each group consisting of multiple holographic structure units, such as... Figure 2The holographic structure units 2011, 2012, 2013, and 2014 form a holographic structure unit group. Each holographic structure unit group is responsible for diffracting the incident light source light to a corresponding target viewpoint. That is, the pixelated holographic structure modulates the light source light emitted from the backlight 10 to generate a light field with multiple target viewpoints 501-504. By modulating the image of each viewpoint, a stereoscopic image visible to the human eye is generated. Furthermore, since the pixelated holographic structure has angle multiplexing or polarization multiplexing characteristics, when the angle or polarization state of the incident light source light is different, each holographic structure unit group deflects the incident light source light to different target viewpoints. Therefore, by changing the emission angle or polarization state of the light source light emitted from the backlight, the light field formed after modulation by the pixelated holographic structure can be changed, that is, the target viewpoint group formed after modulation by the pixelated holographic structure can be changed, thereby realizing viewpoint switching.

[0038] like Figure 1 As shown in Figure a, under the light source 101, the pixelated holographic structure 20 modulates the light source 101 emitted by the backlight 10 into a light field converging at four viewpoints. For example... Figure 1 As shown in b, the light rays diffracted by holographic structure units 2011, 2013, 2031, and 2033 are incident on viewpoint 501. When the direction of the light source is adjusted, for example, taking light source 102, the holographic structure unit group corresponding to the viewpoint deflects the light source light with the new incident direction to the new viewpoint 501. Furthermore, under the illumination of light source 101, the pixelated holographic structure 20 generates four target viewpoints arranged in parallel in a 1*4 pattern along the same direction; under the illumination of light source 102, the pixelated holographic structure 20 generates four target viewpoints arranged in a 2*2 pattern. That is, the arrangement of the multiple target viewpoints in the target viewpoint groups formed by light sources with different incident angles is different.

[0039] In the above technical solution, the present invention adopts a holographic structure in the pixelated diffraction device. The holographic structure can record information of multiple light sources. The present invention changes the directionality of the diffracted light by adjusting the beam characteristics of the light source incident on the pixelated holographic structure 20, that is, changes the backlight characteristics of the incident on the pixelated holographic structure 20, so as to change the multi-viewpoint characteristics formed by the pixelated holographic structure 20. Thus, multiple viewpoint groups can be realized by changing the number and position of the holographic backlight, so that the holographic display system has the functions of variable viewpoint and viewpoint expansion. It can realize holographic display with variable viewpoint for different applications and realize a multi-viewpoint directional backlight.

[0040] In some specific embodiments, the holographic display system further includes an imaging element 30, located in the outgoing light path of the pixelated holographic structure 20. The imaging element 30 modulates the light emitted from each target viewpoint into corresponding target image light. By utilizing the synchronous cooperation between the pixelated holographic structure 20 and the imaging element 30, more viewpoints can be displayed simultaneously based on the time-division multiplexing principle. Combined with the modulation of the imaging element 30, the number of viewpoints in the stereoscopic display system can be increased, or the viewpoint distribution of the holographic display system can be changed according to the application scenario. The imaging element 30 can modulate image information from different viewpoints, generating images with different perspectives from different viewpoints, ultimately achieving multi-viewpoint display.

[0041] Since holographic materials inherently possess the function of recording images, in some specific embodiments, each holographic structural unit group, while focusing the incident light source onto it to a corresponding target viewpoint, simultaneously modulates the incident light source into the corresponding target image light. If the pixelated holographic structure 20 records image information, then the image element 30 may not be necessary. However, correspondingly, the pixelated holographic structure 20, which records image information, can only present a limited number of holographic images.

[0042] In some specific embodiments, the backlight is used to emit light from sources with different emission angles or different polarization states at different times. The beam characteristics of the light emitted by the backlight 10 can be different emission angles and polarization states. That is, by emitting light from the backlight 10 at different angles or with different polarization states, switching between target viewpoint groups composed of multiple target viewpoints can be achieved. In addition, it can also be light from sources of different wavelengths. That is, by emitting light from the backlight 10 at different wavelengths, switching between target viewpoint groups can be achieved. For example, emitting blue light or red light at different times can achieve the display of different target viewpoint groups.

[0043] In some specific embodiments, the backlight 10 includes at least two sets of laser light source components, which operate alternately to output light from different emission angles in a time-division manner, forming... Figure 1 The different viewpoint distributions are shown. Specifically, each laser source component consists of a laser source 110 and an optical component 120, the optical component being used to collimate the emitted light from the laser source to form the source light. For example... Figure 3The coherent light emitted by each laser source 110 is modulated by the optical component 120 to form light incident on the pixelated holographic structure 20. Viewpoint switching of the holographic display system can be achieved by controlling the on / off state of the two sets of laser sources 110. For example, when one set of laser sources 110 is on, the other set is off. At this time, the image element 30 modulates a pattern corresponding to the viewpoint pattern of the light source. Furthermore, in this embodiment, to improve the uniformity of the light emitted from the backlight, the backlight also includes a uniform waveguide. The uniform waveguide includes an input region and an output region. The emitted light from the at least two sets of laser source components is coupled into the input region of the uniform waveguide in a time-division manner, propagates through total internal reflection, exits through the output region of the uniform waveguide, and then incident on the pixelated holographic structure. Using at least two sets of laser source components to achieve light from different emission angles is a simple and easy-to-implement solution, but it is also costly.

[0044] Based on this, in one specific embodiment, the backlight 10 includes at least one laser light source assembly and a moving component (not shown in the figure). The at least one laser light source assembly is mounted on the moving component, and the moving component drives the laser light source assembly to rotate to emit light from the light source at different emission angles in a time-division manner. Figure 3 b in Figure 3 As shown in c, the laser light source assembly is rotated by a moving component to achieve light from different emission angles, which can save the number of light sources and match the incident light angle requirements of more pixelated holographic structures. Specifically, in this embodiment, the laser light source assembly also includes a laser light source 110 and an optical component 120. The optical component 120 is used to collimate the light emitted from the laser light source 110 to generate light from the light source.

[0045] Furthermore, in this embodiment, in order to improve the uniformity of the light emitted from the backlight, the backlight also includes a uniform waveguide, which includes an input region and an output region. The emitted light from the laser light source component is coupled into the input region of the uniform waveguide, and after total internal reflection, it propagates to the output region of the uniform waveguide and is then coupled out and incident on the pixelated holographic structure, so that the light emitted onto the pixelated holographic structure is more uniform.

[0046] In some specific embodiments, the holographic structure unit group includes multiple holographic structure units; when light from a source is incident on it, the spatial angle of the outgoing light formed by the diffraction of the light from the source by each holographic structure unit is less than 90 degrees. Since the high-efficiency angle range of the holographic structure is 15-20 degrees, in order to ensure the diffraction efficiency of the holographic structure, the spatial angle range of the light emitted by the holographic structure units of the pixelated holographic structure 20 needs to be less than 90 degrees when dealing with different viewpoint scenarios; for example, it can be 15 degrees, 20 degrees, 30 degrees, etc.

[0047] In some specific embodiments, the length of the holographic structural unit is 10-600 micrometers. For holographic structural units with a size greater than 600 micrometers, the holographic structural unit is visible to the naked eye, resulting in lower resolution. Conversely, a holographic structural unit size smaller than 10 micrometers would increase manufacturing difficulty; therefore, the size of the holographic structural unit needs to be greater than 10 micrometers.

[0048] In some specific embodiments, the plurality of holographic structural unit groups are interlocked in an ordered or disordered manner, so that all the holographic structural units are laid out flat on the light-emitting surface of the backlight. This allows the pixelated holographic structure to have a compact arrangement and a relatively small area.

[0049] In some embodiments, the present invention also provides a pixel exposure method for a pixelated holographic structure, comprising the steps of: S1. Use a pixelated mask 1 superimposed on the holographic film to cover the non-target holographic structural unit group to expose the target holographic structural unit group 1; S2, using the first reference beam 101 and the first object beam 601 (e.g.) Figure 4 (As shown) the target holographic structure unit group is exposed, and the first object beam 601 and the first reference beam 101 converge to a focal point 1 on the other side of the holographic film; S3, using a second reference beam 102 and a second object beam 603 (such as...) Figure 6 (As shown) the target holographic structure unit group is exposed, and the second object beam 603 and the second reference beam 102 converge to a focal point 2 on the other side of the holographic film; S4. Repeat the above steps until all incident angles corresponding to the target holographic structure unit group 1 have been exposed. S5. Remove the pixelated mask 1, and use a single-layer or double-layer pixelated mask to superimpose on the holographic film to cover the non-target holographic structure unit group to expose the target holographic structure unit group 2. S6, Using the first reference beam 101 and the third object beam 602 (e.g. Figure 5(As shown) the target holographic structure unit group is exposed, and the first reference beam 101 and the third object beam 602 converge to a focal point 3 on the other side of the holographic film; S7. The target holographic structure unit group is exposed using a second reference beam 102 and a fourth object beam 604 (not shown). The second reference beam 102 and the fourth object beam 604 (not shown) converge to a focal point 4 on the other side of the holographic film. S8. Repeat the above steps until all incident angles corresponding to the target holographic structure unit group 2 have been exposed. S9. Remove the pixelated mask and repeat the above steps so that all holographic structural unit groups on the final holographic film are exposed.

[0050] The above exposure method is intended to prepare the pixelated holographic structure. Steps S1-S4 can simultaneously expose and prepare all holographic structural units corresponding to one holographic structural unit group, giving them angle multiplexing characteristics. Steps S5-S8 can expose and prepare all holographic structural units corresponding to another holographic structural unit group, giving them angle multiplexing characteristics. By repeating the above process, the preparation of all holographic structural unit groups can be completed. Since multiple holographic structural units can be exposed simultaneously, this method has higher preparation efficiency compared to the pixelated grating structure corresponding to the surface relief grating structure in the prior art.

[0051] In some specific implementations, step S1 above specifically includes the following steps: S10. Provide a first protective film layer 202 and a second protective film layer 203, as well as a first pixelation mask 204 and a second pixelation mask 205; such that the first protective film layer 202 and the second protective film layer 203 are respectively located on both sides of the functional layer 201 of the holographic film, the first pixelation mask 204 is located on the side of the first protective film layer 202 away from the functional layer 201, and the second pixelation mask 205 is located on the side of the second protective film layer 203 away from the functional layer 201. S20. Alignment marks on the first pixelated mask 204 and the second pixelated mask 205 are used to align and install the first pixelated mask 204 and the second pixelated mask 205 with the holographic film containing the first protective film layer 202 and the second protective film layer 203, so that the non-target holographic pixel structure unit group is masked.

[0052] In some specific embodiments, the functional layer 201 is a photopolymer holographic photosensitive layer, a dichromate gelatin holographic photosensitive layer, a silver halide holographic photosensitive layer, or a photorefractive holographic photosensitive layer.

[0053] In this embodiment, such as Figure 7 As shown, the holographic film material is a three-layer sandwich structure during fabrication. The middle layer is a functional layer 201, which is made of holographic material and is used to modulate light from light sources with different beam characteristics into a light field that converges to the corresponding target viewpoint. The two sides of the functional layer 201 are a first protective film layer 202 and a second protective film layer 203, both of which are made of optically transparent material. The first pixelation mask 204 is located on the side of the first protective film layer 202 away from the functional layer 201, and the second pixelation mask 205 is located on the side of the second protective film layer 203 away from the functional layer 201. This three-layer sandwich structure allows for accurate masking of the non-exposed areas of the holographic film and also protects the holographic film during the exposure fabrication process.

[0054] In other specific embodiments, a single-layer mask can also be used for exposure, that is, only the first pixelated mask 204 is needed. The first pixelated mask 204 is located on the side of the first protective film layer 202 away from the functional layer 201. When a pixelated mask is required for exposure, the first pixelated mask 204 needs to be aligned with the alignment marks of the pixelated holographic structure 20 before exposure. Compared with the above-described two-layer mask method, using a single-layer mask simplifies the process and increases efficiency.

[0055] In some other specific embodiments, in order to reduce the mask replacement and alignment process during the exposure of the pixelated holographic structure 20, this embodiment provides a pattern of pixelated light-transmitting areas and non-light-transmitting areas on the first protective film layer 202 and the second protective film layer 203, so that the pixelated holographic structure 20 can be directly exposed.

[0056] In other embodiments, multiple layers of pixelated exposure holographic structures under different mask patterns can be stacked and merged into a single pixelated holographic structure 20 with full pixel functionality. For example, assuming the pixelated holographic structure has four pixel regions, the first pixel region of the first pixelated holographic structure is exposed, the second pixel region of the second pixelated holographic structure is exposed, the third pixel region of the third pixelated holographic structure is exposed, and the fourth pixel region of the fourth pixelated holographic structure is exposed. By bonding the four pixelated holographic structures together, a holographic structure with complete pixels can be formed.

[0057] In summary, the holographic display system provided by this utility model has the following beneficial effects: By adjusting the beam characteristics of the light source incident on the pixelated holographic structure, the directivity of the diffracted light can be altered, thereby changing the number and position of the holographic backlight. This allows the holographic display system to have variable and expandable viewpoints. The pixelated display structure, combined with exposure field design, improves the fabrication efficiency and feasibility of the pixelated holographic structure through parallel exposure. It should be understood that the application of this invention is not limited to the examples described above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A holographic display system, characterized in that, include: A backlight source, wherein the backlight source is used to generate light source light with adjustable beam characteristics; A pixelated holographic structure is located on the outgoing light path of the light source. The pixelated holographic structure includes multiple holographic structure unit groups, and each holographic structure unit group converges the light source incident on it to a corresponding target viewpoint. When different light sources emitted from the backlight are incident on the pixelated holographic structure in a time-division manner, the pixelated holographic structure is used to modulate the light source into a light field that converges to the corresponding target viewpoint group. The target viewpoint group includes multiple target viewpoints formed by multiple holographic structure unit groups.

2. The holographic display system according to claim 1, characterized in that, When each of the holographic structural unit groups converges the incident light source light onto a corresponding target viewpoint, it simultaneously modulates the incident light source light onto the target image light.

3. The holographic display system according to claim 1, characterized in that, The holographic display system further includes an image element located in the outgoing light path of the pixelated holographic structure. The image element modulates the light emitted from each target viewpoint into the corresponding target image light.

4. The holographic display system according to claim 1, characterized in that, The backlight is used to emit light from sources with different emission angles or different polarization states in a time-division manner.

5. The holographic display system according to claim 4, characterized in that, The backlight includes at least two sets of laser light source components, which work alternately to output light from different emission angles in a time-division manner.

6. The holographic display system according to claim 4, characterized in that, The backlight also includes a laser light source assembly and a moving component. The laser light source assembly is mounted on the moving component, and the moving component drives the laser light source to rotate so as to emit light from the light source at different emission angles in a time-division manner.

7. The holographic display system according to claim 5 or 6, characterized in that, The laser source assembly includes a laser source and an optical component. The laser source is used to generate coherent light. The optical component is located in the output light path of the laser source and is used to collimate the coherent light.

8. The holographic display system according to claim 5 or 6, characterized in that, The backlight source also includes a uniform waveguide, which comprises an input region and an output region. The uniform waveguide is disposed in the output optical path of the at least two sets of laser source components. The output light from the at least two sets of laser source components is coupled into the coupling region of the uniform waveguide in a time-division manner, propagates to the coupling region of the uniform waveguide after total internal reflection, and exits from the coupling region of the uniform waveguide before being incident on the pixelated holographic structure; or, The uniform waveguide is set in the light output path of the laser source component. The light emitted from the laser source component is coupled into the coupling region of the uniform waveguide, propagates to the coupling region of the uniform waveguide after total internal reflection, and is coupled out from the coupling region of the uniform waveguide and incident on the pixelated holographic structure.

9. The holographic display system according to claim 1, characterized in that, The holographic structural unit group includes multiple holographic structural units; When light from a source is incident on it, the spatial angle of the outgoing light formed by the diffraction of the light from the source by each holographic structural unit is less than 90 degrees; or, The holographic structural unit is rectangular, and its length is 10-600 micrometers; or, The multiple holographic structural unit groups are interlocked in an ordered or disordered manner so that all the holographic structural units are laid out flat on the light-emitting surface of the backlight.

10. The holographic display system according to claim 1, characterized in that, Light from light sources with different incident angles corresponds to the formation of target viewpoint groups, and the arrangement of the multiple target viewpoints is different.

Images