Volume holographic optical waveguide exposure equipment

Abstract

The utility model discloses volume holographic optical waveguide exposure equipment, which can complete splicing exposure of a to-be-exposed area by switching a plurality of baffle plates to perform multiple exposure when the area of the to-be-exposed area is large, and can repeatedly utilize the baffle plates and mask plates for different types of optical waveguides or different shapes of to-be-exposed areas. The utilization rate of the baffle plate and the mask plate is increased to a certain extent, and the cost for manufacturing the baffle plate and the mask plate is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductors, in particular to a volume holographic optical waveguide exposure device. Background Art

[0002] Augmented Reality (AR) technology revolutionizes visual experience and human-computer interaction, seamlessly integrating real-world and virtual-world information. The optical display system of an AR device typically consists of a microdisplay and optical components. Head-up displays (HUDs) are currently very popular in the market. Automotive HUDs that utilize AR technology offer a wider field of view and a longer imaging distance, resulting in a wider field of view, superior imaging quality, and improved user interactivity.

[0003] Currently, the waveguides used in AR-HUDs are generally volume holographic waveguides or surface relief waveguides. Volume holographic waveguides are widely used due to their relative advantages in manufacturing difficulty and cost. However, a problem exists: different waveguide types require different baffles, and the same waveguide typically requires at least two baffles (incoupling and outcoupling). This requires numerous baffles to expose different waveguide types, which can be a significant burden and increase production costs. Utility Model Content

[0004] The utility model provides a volume holographic optical waveguide exposure device, which enables splicing exposure to be performed in a switching manner through multiple baffles when the area to be exposed is large. Baffles and masks can be reused for optical waveguides of different models or areas to be exposed of different shapes, thereby increasing the utilization rate of the baffles and masks and reducing the cost of manufacturing the baffles and masks.

[0005] The utility model proposes a volume holographic optical waveguide exposure device, comprising: a baffle assembly, a mask assembly and a workpiece stage for carrying the exposed waveguide plate, which are sequentially arranged along the transmission direction of the exposure beam;

[0006] The baffle assembly includes a plurality of baffle modules, each of which includes at least one baffle, and each baffle includes a light-transmitting area. When the baffle module includes a plurality of baffles, the light-transmitting areas of different baffles have different shapes and / or sizes. The light-transmitting areas of the baffles in the baffle module can be spliced ​​to form an area to be exposed on the waveguide sheet. The baffle modules can be switched between different modules and between different baffles in the same baffle module.

[0007] The mask assembly includes at least one mask, which includes a periodic grating mask structure. When exposing an area to be exposed of the waveguide plate, the baffle and mask corresponding to the current exposure of the area to be exposed can be simultaneously switched to the path of the exposure beam transmission.

[0008] Optionally, when there are multiple masks, different masks correspond to different areas to be exposed on the waveguide plate, and different masks can be switched; the periodic grating mask structures on different masks have different periods and / or shapes.

[0009] Optionally, the volume holographic waveguide exposure apparatus further comprises: a switching support module, the switching support module comprising at least one support unit, the support unit comprising a support shaft and a plurality of support rods, one end of each support rod being connected to the support shaft, and the other end being connected to a connector for the baffle and / or the mask; the support rods being capable of rotating about the support shaft. Optionally, the plurality of baffles are located in a first plane, and the plurality of masks are located in a second plane, the first and second planes being sequentially arranged along the transmission direction of the exposure beam, the support rods located in the first plane being connected to the connector for the baffle, and the support rods located in the second plane being connected to the connector for the mask.

[0010] Optionally, the baffle is fixedly arranged with the mask, the baffle is a light-shielding layer with a light-transmitting area attached to the mask, and the support rods are located in the same plane and connected to the connector of the mask.

[0011] Optionally, the baffle module includes at least a first baffle module and a second baffle module, the baffle in the first baffle module is located in a third plane, the baffle in the second baffle module is located in a fourth plane, the mask is located in the second plane, the third plane and the second plane are arranged in sequence along the exposure beam transmission direction, the fourth plane and the second plane are arranged in sequence along the exposure beam transmission direction, and the third plane and the fourth plane are not coplanar.

[0012] Optionally, the switching bracket module includes a plurality of bracket units, one of which is used to carry the mask assembly, and the number of the remaining bracket units is the same as that of the baffle modules, and are respectively used to carry baffles in the corresponding baffle modules.

[0013] Optionally, the volume holographic optical waveguide exposure device further comprises: a light source module, configured to form the exposure light beam;

[0014] The light source module includes a laser, a switch element, a beam shaping element, a first beam expanding element, a polarization element, a second beam expanding element, a reflecting element and a light blocking element arranged in sequence along the light transmission direction. The outer diameter of the light blocking element is larger than the diameter of the light spot formed by the exposure beam, and the inner diameter of the light blocking element is smaller than the diameter of the light blocking area of ​​the mask.

[0015] Optionally, the reflection angle of the reflective element is adjustable.

[0016] Optionally, the volume holographic optical waveguide exposure device further comprises: a light absorbing element, which is located on a side of the waveguide plate away from the mask plate and is used to absorb the exposure light beam passing through the waveguide plate.

[0017] Optionally, the volume holographic optical waveguide exposure device further comprises: a liquid spraying part, comprising a liquid spraying nozzle and a moving axis, for spraying a refractive index matching liquid onto the upper surface of the waveguide plate;

[0018] An alignment camera assembly includes at least one camera to capture the alignment mark on the waveguide plate and align it with the alignment mark on the mask.

[0019] According to an embodiment of the present invention, the volume holographic optical waveguide exposure device proposed includes: a baffle assembly, a mask assembly and a workpiece table for carrying the exposed waveguide plate, which are arranged in sequence along the transmission direction of the exposure beam; the baffle assembly includes a plurality of baffle modules, the baffle module includes at least one baffle, and the baffle includes a light-transmitting area; when the baffle module includes a plurality of baffles, the light-transmitting areas in different baffles have different shapes and / or sizes, and the light-transmitting areas of each baffle in the baffle module can be spliced ​​to form an area to be exposed on the waveguide plate, and can be switched between different baffle modules and between different baffles of the same baffle module; the mask assembly includes at least one mask, and the mask includes a periodic grating mask structure, wherein, when exposing an area to be exposed of the waveguide plate, the baffle and mask corresponding to the current exposure of the area to be exposed can be switched to the path of the exposure beam transmission at the same time. Therefore, this technical solution allows for multiple exposures of a large area to be exposed by switching between multiple baffles, completing the spliced ​​exposure of the area. Furthermore, different masks can be switched for different areas to be exposed, thereby increasing the utilization of baffles and masks, reducing the cost of manufacturing them, and reducing the size of the equipment. Furthermore, when the areas to be exposed are different, the shape of the area to be exposed can be formed by splicing different baffles.

[0020] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present invention, nor is it intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 This is a schematic structural diagram of a volume holographic optical waveguide exposure device proposed in an embodiment of the present utility model;

[0023] Figure 2 This is a schematic structural diagram of a baffle in a volume holographic optical waveguide exposure device proposed in an embodiment of the present utility model;

[0024] Figure 3 This is a schematic structural diagram of a waveguide sheet to be exposed in the volume holographic optical waveguide exposure device proposed in an embodiment of the present utility model;

[0025] Figure 4 This is a schematic structural diagram of multiple baffles in a baffle module of a volume holographic optical waveguide exposure device proposed in an embodiment of the present invention;

[0026] Figure 5 This is a schematic structural diagram of multiple baffles in another baffle module of the volume holographic optical waveguide exposure device proposed in an embodiment of the present utility model;

[0027] Figure 6 This is a schematic structural diagram of multiple masks in a mask assembly of a volume holographic optical waveguide exposure device proposed in an embodiment of the present invention;

[0028] Figure 7 This is a structural diagram of a switching bracket module in the volume holographic optical waveguide exposure device proposed in an embodiment of the present utility model;

[0029] Figure 8 This is a structural diagram of another switching bracket module in the volume holographic optical waveguide exposure device proposed in an embodiment of the present utility model;

[0030] Figure 9 This is a structural diagram of another switching bracket module in the volume holographic optical waveguide exposure device proposed in an embodiment of the present utility model;

[0031] Figure 10 This is a structural diagram of the light source module of the volume holographic optical waveguide exposure device proposed in an embodiment of the present utility model;

[0032] Figure 11This is a structural schematic diagram of a light blocking element in a volume holographic optical waveguide exposure device proposed in an embodiment of the present utility model;

[0033] Figure 12 This is a schematic structural diagram of a volume holographic optical waveguide exposure device proposed in a specific embodiment of the present invention;

[0034] Figure 13 This is a schematic structural diagram from another perspective of a volume holographic optical waveguide exposure device proposed in a specific embodiment of the present invention;

[0035] Figure 14 It is a schematic diagram of the process of preparing the waveguide plate part in the volume holographic optical waveguide exposure equipment proposed in a specific embodiment of the utility model. DETAILED DESCRIPTION

[0036] In order to help those skilled in the art better understand the present invention, the following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0037] It should be noted that the terms "first," "second," and the like in the specification and claims of the present invention and the accompanying drawings are used to distinguish similar items and are not necessarily used to describe a specific order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, such that the embodiments of the present invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "including," "having," and any variations thereof are intended to cover non-exclusive inclusions.

[0038] In related technologies, a volume holographic waveguide generally includes an input region, a turning region, and an output region. The input region is used to couple external light carrying image information into the volume holographic waveguide. The turning region and the output region are used to propagate and expand the coupled external light. The output region is also used to couple the light in the volume holographic waveguide out to form an output light field for the human eye to receive, thereby observing the relevant image information. Among them, the area of ​​the input region is generally small, and the corresponding mask and baffle can be used for exposure. However, the area of ​​the turning region and the output region is generally large. If a baffle is used for exposure, a baffle with a larger area needs to be made. In addition, when the shape and contour of the turning region or the output region changes, the baffle cannot be reused, resulting in a waste of resources.

[0039] Based on the above, embodiments of the present invention provide a volume holographic waveguide exposure device capable of splicing multiple baffles to expose the same area to be exposed. This allows the light-transmitting areas of the multiple baffles to be spliced ​​into different contours, allowing exposure of areas with different contours, as well as exposure of areas corresponding to the contour of a single baffle's light-transmitting area. This improves baffle utilization, reduces the number of baffle production cycles, and reduces costs.

[0040] Figure 1 This is a schematic diagram of the structure of the volume holographic optical waveguide exposure device proposed in the embodiment of the present utility model. Figure 1 As shown, the volume holographic optical waveguide exposure device 100 includes: a baffle assembly 200, a mask assembly 300 and a workpiece stage 400 for carrying the waveguide plate 101 to be exposed, which are sequentially arranged along the transmission direction of the exposure beam;

[0041] The baffle assembly 200 includes a plurality of baffle modules 201, each of which includes at least one baffle 2011. The baffle 2011 includes a light-transmitting area A. When the baffle module 201 includes a plurality of baffles 2011, the light-transmitting areas A in different baffles 2011 have different shapes and / or sizes. The light-transmitting areas A of the baffles 2011 in the baffle module 201 can be spliced ​​together to form a region B to be exposed on the waveguide 101. Switching between different baffle modules 201 and between different baffles 2011 in the same baffle module 201 is possible.

[0042] The mask assembly 300 includes at least one mask 301, which includes a periodic grating mask structure. When exposing an area B to be exposed on the waveguide plate 101, the baffle 2011 and the mask 301 corresponding to the current exposure area B to be exposed can be simultaneously switched to the path of exposure beam transmission.

[0043] Among them, reference Figure 1 After exposure, the waveguide plate 101 can form a volume holographic optical waveguide. In this embodiment, the waveguide plate 101 can be a HUD waveguide plate, and its structure can be two layers of glass with a volume holographic material sandwiched between them. During the exposure process of the waveguide plate 101, the reticle 301 is located on the side closest to the waveguide plate 101. The projection of the reticle 301 on the plane of the waveguide plate 101 at least partially overlaps with the waveguide plate 101. The reticle 301 is provided with a periodic grating mask structure. During exposure, the pattern corresponding to the periodic grating mask structure on the reticle 301 can be transferred to the volume holographic material. The baffle 2011 is located on the side of the reticle 301 away from the waveguide plate 101, that is, the reticle 301 is located between the baffle 2011 and the waveguide plate 101. The projection of the baffle 2011 on the plane of the waveguide plate 101 at least partially overlaps with both the reticle 301 and the waveguide plate 101. Figure 2 This is a schematic diagram of the structure of a baffle in the volume holographic optical waveguide exposure device proposed in the embodiment of the present invention, with reference to Figure 2 A light-transmitting area A is provided on the baffle 2011 , and the exposure beam can pass through the light-transmitting area A of the baffle 2011 and illuminate the mask plate 301 , thereby transferring the pattern of the periodic grating mask structure on the mask plate 301 to the waveguide plate 101 .

[0044] Baffle 2011 has a light transmittance of 100% in the exposure area and 0% in the non-exposure area, thereby achieving a single-exposure target pattern. The material of baffle 2011 is not limited, as long as its transmittance within the laser wavelength band is 0%. Baffle 2011 must be less than 0.1 mm thick to mitigate edge diffraction effects of the grating.

[0045] It should be noted that Figure 3 This is a schematic structural diagram of a waveguide sheet to be exposed in the volume holographic optical waveguide exposure device proposed in the embodiment of the present invention, with reference to Figure 3 When exposing the waveguide plate 101, the exposed region B of the waveguide plate 101 needs to be exposed. The exposed region B includes the incoupling region B1, the turning region B2, and the outcoupling region B3. Thus, the incoupling region B1, the turning region B2, and the outcoupling region B3 need to be exposed to form a volume holographic optical waveguide. In other embodiments, the exposed region B of the waveguide plate 101 may include only the incoupling region B1 and the outcoupling region B3.

[0046] The baffle module 201 corresponds to the area B to be exposed on the waveguide plate 101. That is, when exposing the incoupling area B1, the baffle 2011 in the baffle module 201 corresponding to the incoupling area B1 is used; when exposing the turning area B2, the baffle 2011 in the baffle module 201 corresponding to the turning area B2 is used; when exposing the outcoupling area B3, the baffle 2011 in the baffle module 201 corresponding to the outcoupling area B3 is used. Since the incoupling area B1 is generally small in area, the baffle 2011 in the baffle module 201 corresponding to it can be one (e.g., Figure 2 As shown in FIG. 1 ). Since the areas of the turning region B2 and the outcoupling region B3 are generally large, the baffle 2011 in the corresponding baffle module 201 can be divided into multiple parts (such as Figure 4 In the figure are a plurality of baffles 2011 corresponding to the turning area B2, as shown in FIG. Figure 5 , which are multiple baffles 2011 corresponding to the outcoupling area B3). For example, when the turning area B2 is exposed, Figure 4 The baffles 2011 in the image are switched in sequence, and finally the splicing exposure of the turning area B2 is completed. Figure 4The splicing outline of the light-transmitting areas of each baffle 2011 is the outline of the turning area B2. The exposure principle of the outcoupling area B3 is the same as that of the turning area B2, and will not be repeated here.

[0047] It should be noted that the spliced ​​outline of the light-transmitting areas A of the baffles 2011 in the same baffle module 201 is identical to the outline of the corresponding area to be exposed B. The shapes and / or sizes of the light-transmitting areas A of the baffles 2011 are different. The shapes and / or sizes of the light-transmitting areas A of the baffles can be determined based on the outline of the corresponding area to be exposed B, as well as the compatibility of the outlines of other exposure areas on the substrate to be exposed with the light-transmitting area A of a single baffle, thereby increasing the utilization rate of the baffles 2011.

[0048] Alternatively, if the periodic grating mask structure required for each to-be-exposed region B on the waveguide plate 101 is the same, then the reticle 301 in the reticle assembly 300 may be a single reticle. If the periodic grating mask structure required for each to-be-exposed region B on the waveguide plate 101 is the same but at different angles, then the reticle 301 in the reticle assembly 300 may be a single reticle. During exposure, the workpiece stage 400 may be controlled to adjust the position of the waveguide plate 101 so that the waveguide plate 101 and the periodic grating mask structure on the reticle 301 have corresponding angles.

[0049] Optionally, when there are multiple masks 301, different masks 301 correspond to different areas B to be exposed on the waveguide plate 101, and different masks 301 can be switched; the periodic grating mask structures on different masks 301 have different periods and / or shapes to meet the requirements of different areas B to be exposed.

[0050] If the periodic grating mask structures required for each area B to be exposed on the waveguide plate 101 are different, the mask plate assembly 300 may include multiple masks 301, each mask plate 301 corresponding to a different area B to be exposed (e.g., Figure 6 The masks shown in FIG respectively correspond to different to-be-exposed areas B of the waveguide plate 101 . In this way, the same mask 301 has only one periodic grating mask structure, thereby increasing the utilization rate of the mask 301 .

[0051] When exposing the area B to be exposed, the corresponding mask 301 and baffle 2011 can be switched to be located on the transmission path of the exposure light beam to complete the exposure of the area B to be exposed.

[0052] Optionally, Figure 7 FIG. 1 is a structural diagram of a switching bracket module in a volume holographic optical waveguide exposure device proposed in an embodiment of the present invention; Figure 7As shown, the volume holographic optical waveguide exposure apparatus 100 further includes: a switching support module 500, the switching support module 500 including at least one support unit 501, the support unit 501 including a support shaft 5011 and a plurality of support rods 5012, one end of the support rod 5012 is connected to the support shaft 5011, and the other end is connected to a connector for connecting the baffle 2011 and / or the mask 301;

[0053] The support rod 5012 is rotatable around the support shaft 5011 .

[0054] It is understood that the support shaft 5011 and the support rod 5012 can be fixedly connected, and the support rod 5012 can rotate by the rotation of the support shaft 5011, wherein the support shaft 5011 can be driven by a motor. When the other end of the support rod 5012 is connected to the connecting member of the baffle 2011 and / or the mask 301, the connecting end of the support rod 5012 can be provided with a connector that can be connected and used with the connecting member of the baffle 2011 and / or the mask 301, such as a snap or a lock. For example, the support rod 5012 can be provided with a first connector, and the baffle and / or the mask 301 can be provided with a second connector, and the first and second connectors can be connected to each other, so that the support rod 5012 can be connected to the baffle and / or the mask 301. In one embodiment, the first connector provided on the support rod 5012 can rotate on the support rod 5012, thereby adjusting the angle of the baffle 2011 and / or the mask 301 relative to the support rod 5012 after being connected thereto.

[0055] The reticle 301 in the support unit 501 is positioned closer to the waveguide 101, while the baffle 2011 is positioned closer to the reticle 301 and further away from the waveguide 101. Along the exposure beam transmission direction z, the plurality of support rods 5012 can be divided into upper and lower sections: the upper section supports the baffle 2011, and the lower section supports the reticle 301. The support rods 5012 in each section can be arranged to radiate outward from the support shaft 5011. When exposing the to-be-exposed area B of the waveguide 101, the light-transmitting area A of the baffle 2011 and the corresponding reticle 301 can be switched to the exposure beam transmission direction z by controlling the support unit 501.

[0056] Optionally, multiple baffles 2011 are located on a first plane, multiple masks 301 are located on a second plane, and the first and second planes are sequentially arranged along the exposure beam transmission direction z. The support rods located on the first plane are connected to the connectors of the baffles 2011, and the support rods 5012 located on the second plane are connected to the connectors of the masks 301.

[0057] In other words, all baffles 2011 are located in the same plane, and all reticles 301 are located in the same plane. The number of baffle modules 201 corresponds to the number of areas B to be exposed on the waveguide plate 101. In other words, all baffles 2011 in all baffle modules 201 are located in the same plane (first plane), and all reticles 301 are located in the same plane (second plane). This embodiment is suitable for situations where the number of baffles 2011 and reticles 301 is small.

[0058] Optionally, the baffle 2011 is fixed to the mask 301 , and the baffle 2011 is a light shielding layer having a light-transmitting area A attached to the mask 301 . The support rods 5012 are located in the same plane and connected to the connector of the mask 301 .

[0059] Among them, two support columns 5014 (such as Figure 12 As shown), the support rod 5012 is snap-connected with the support column 5014, the baffle 2011 is attached to the mask 301, and the support rods 5012 are all located in the same plane and are connected to the mask 301, which can reduce the height of the bracket unit 501 and reduce the volume of the bracket unit 501.

[0060] Optionally, Figure 8 FIG. 1 is a structural diagram of another switching bracket module in the volume holographic optical waveguide exposure device proposed in an embodiment of the present invention; Figure 8 As shown,

[0061] The baffle module 201 includes at least a first baffle module 201A and a second baffle module 201B, the baffle in the first baffle module 201A is located in the third plane, the baffle in the second baffle module 201B is located in the fourth plane, the mask 301 is located in the second plane, the third plane and the second plane are arranged in sequence along the exposure beam transmission direction z, the fourth plane and the second plane are arranged in sequence along the exposure beam transmission direction z, and the third plane and the fourth plane are not coplanar.

[0062] The switching support module 500 may include a support unit 501. When the number of baffles 2011 and reticles 301 is large, multiple support rods 5012 may be arranged in layers along the exposure beam transmission direction z to arrange the baffles 2011 and reticles 301 in multiple layers. The bottom layer of baffles 2011 is positioned above the top layer of reticles 301. Furthermore, to ensure a consistent spacing between the baffles 2011 and reticles 301 during exposure, in this embodiment, the support rods 5012 may be retractable and angled relative to the support shaft 5011, similar to an umbrella-shaped support structure. This allows for more flexible adjustment of the positions of the baffles 2011 and / or reticles 301.

[0063] In one embodiment, the number of baffle modules 201 corresponds to the number of exposure regions B on the waveguide sheet 101. The baffles 2011 in different baffle modules 201 are arranged in different planes. In other words, the baffles 2011 in the same baffle module 201 can be located in the same plane. In another embodiment, the baffles 2011 in the same baffle module 201 can be layered and located in different planes, depending on the number of baffles 2011 in the baffle module 201 and the number of support rods 5012 that can be arranged on the support shaft 5011 of the bracket unit 501. Similarly, if necessary, the mask 301 can also be layered and arranged in different planes.

[0064] In one embodiment, there may be multiple support units 501, with the baffle module 201 and mask 301 in each support unit 501 corresponding to one of the to-be-exposed areas B. Alternatively, one support unit 501 may be provided with the mask assembly 300, and another support unit 501 may be provided with the baffle assembly 200. Alternatively, one support unit 501 may be provided with the mask assembly 300, and different support units 501 may be provided with different baffle modules 201.

[0065] Optionally, Figure 9 FIG. 1 is a structural diagram of another switching bracket module in the volume holographic optical waveguide exposure device proposed in an embodiment of the present invention; Figure 9 As shown, the switching bracket module 500 includes multiple bracket units 501, one of which is used to carry the mask assembly 300, and the number of the remaining bracket units 501 is the same as that of the baffle modules 201, and is respectively used to carry the baffles 2011 in the corresponding baffle modules 201.

[0066] The baffle module 201 includes a first baffle module 201A and a second baffle module 201B. The first baffle module 201A is supported by a support unit 501 (support shaft and support rod), the second baffle module 201B is supported by a support unit 501 (support shaft and support rod), and the mask assembly 300 is supported by a support unit 501 (support shaft and support rod). Figure 9 As shown, three support units 501 are arranged in a tree structure. For the decoupling region or transition region, since a single mask 301 generally requires multiple baffles 2011, the support rods 5012 (bold black lines in the figure) in the support unit 501 supporting the mask assembly 300 are longer than the support rods 5012 (thin black lines in the figure) supporting the baffle module 201, facilitating switching. Furthermore, only two layers, baffles 2011 and masks 301, are provided along the exposure beam transmission direction z. This arrangement makes it easier to meet the exposure spacing between the two.

[0067] Figure 10 This is a structural diagram of a light source module in a volume holographic optical waveguide exposure device proposed in an embodiment of the present invention; Figure 11 Schematic diagram of the structure of the light blocking element of the volume holographic waveguide exposure device proposed in the embodiment of the present invention; optionally, as Figure 10 and Figure 11 As shown, the volume holographic optical waveguide exposure device 100 further includes: a light source module 600 for forming an exposure beam;

[0068] The light source module 600 includes a laser 601, a switching element 602, a beam shaping element 603, a first beam expanding element 604, a polarization element 605, a second beam expanding element 606, a reflecting element 607 and a light blocking element 608 arranged in sequence along the light transmission direction. The outer diameter of the light blocking element 608 is larger than the diameter of the light spot formed by the exposure beam L, and the inner diameter of the light blocking element 608 is smaller than the diameter of the light blocking area of ​​the mask 301.

[0069] The laser 601 emits a laser beam. The light-opening element 602 can be an electrically controlled switch located along the laser beam transmission path, used to cut off or open the laser beam transmission to control the laser exposure time. The beam shaping element 603 can be a flat-top beam shaper, used to convert a Gaussian beam into a flat-top beam, thus homogenizing the beam. The first beam expander 604 is a primary beam expander, used to initially expand the light spot by a factor of 8-12. The polarization element 605 adjusts the polarization direction of the polarized light spot and can be a half-wave plate. The second beam expander 606 is a secondary beam expander, further expanding the light spot to the target size. It can be a combination of a spatial filter and a large convex lens, a convex lens, an aperture, and a large convex lens, or a concave lens, an aperture, and a large convex lens. The reflective element 607 is a reflector, used to deflect the light path and project the light spot onto the workpiece stage 400. The workpiece stage 400 is used to place the waveguide 101 and perform subsequent processing operations. As described above, the effects of modulating the spot size, light intensity, light intensity uniformity, propagation direction, and polarization direction can be achieved.

[0070] Figure 12 FIG. 1 is a schematic structural diagram of a volume holographic optical waveguide exposure device proposed in a specific embodiment of the present invention; Figure 11 and Figure 12 As shown, the light blocking element 608 is annular (ie, as shown in FIG. Figure 11The light transmittance is 0% (outlined by the thicker black line in the figure). The outer diameter of the light blocking element 608 is slightly larger than the spot diameter of the exposure beam L, and the inner diameter of the light blocking element 608 is slightly smaller than the outer diameter of the light blocking area of ​​the reticle 301. This prevents the exposure beam L from irradiating other areas, ensuring that the exposure beam L can illuminate the light-transmitting area A of the baffle 2011 and the periodic grating mask structure of the reticle 301. Furthermore, after the light spot passes through the light blocking element 608, the baffle 2011, and the reticle 301, the pattern after exposure of the waveguide plate 101 is the target pattern, and no stray light exposure pattern is generated.

[0071] Optionally, Figure 12 FIG. 1 is a schematic structural diagram of a volume holographic optical waveguide exposure device proposed in a specific embodiment of the present invention; Figure 12 As shown, the reflection angle of the reflective element 607 is adjustable.

[0072] Among them, the reflective element 607 can be a reflector. The material of the reflector is not limited, as long as the reflectivity in the laser band is greater than 98%. The reflector part is equipped with an electrically controlled displacement stage, which moves along the y-axis; and a Φ-angle electrically controlled rotation stage, which rotates in the yz plane. By adjusting the rotation angle of the reflector, the angle of the light spot incident on the mask is adjusted, and then the tilt angle of the volume holographic grating is controlled to obtain the target grating structure. However, as the rotation angle of the reflector changes, the position of the center of the light spot also changes, which brings great complexity to the motion design of the carrier platform. Therefore, an electrically controlled displacement stage is configured to synchronously control the movement of the reflector on the y-axis and adjust the center of the light spot back to the origin. The combination of the electrically controlled displacement stage and the electrically controlled rotation stage can achieve only the change of the tilt angle of the light spot without changing the position of the center of the light spot after reflection, greatly reducing the design complexity of the carrier platform.

[0073] Optionally, continue to refer to Figure 12 The volume holographic waveguide exposure apparatus 100 further includes a light-absorbing element 700, located on the side of the waveguide plate 101 away from the reticle 301. This element absorbs the exposure beam transmitted through the waveguide plate. The material of the light-absorbing element 700 exhibits an absorptivity greater than 95% within the laser wavelength range, and the size of the light-absorbing element 700 is comparable to that of the HUD waveguide plate 101. Alternatively, a prismatic irregular glass device can be used to direct light from the bottom surface of the waveguide plate 101, preventing light from being reflected back into the waveguide plate 101 and affecting exposure.

[0074] Continue to refer Figure 12 and Figure 13The volume holographic waveguide exposure apparatus 100 also includes a liquid spraying unit 800, which includes a liquid spray nozzle and a movable axis. This unit sprays refractive index matching liquid 01 onto the upper surface of the waveguide plate 101, replenishing the liquid after the reticle 301 is replaced. The refractive index of the liquid matches that of the waveguide plate 101 and the reticle 301, aiding light transmission. The movable range of the liquid spray nozzle's fixed axis is within the waveguide plate 101. The displacement target for a single exposure is the center of the reticle 301, and the liquid output per single exposure is sufficient to fully cover the contact area between the reticle 301 and the waveguide plate 101 with the refractive index matching liquid 01. The liquid spraying method is not limited and can be either piezoelectric or pneumatic.

[0075] The volume holographic waveguide exposure apparatus 100 also includes a movable alignment camera assembly 900, which includes a set of lenses for alignment. Once alignment is complete, the camera assembly can be moved outside the carrier platform to prevent interference with exposure. The movable area of ​​the alignment camera's movable arm is the outer ring area of ​​the reticle 301. Alignment marks are engraved on the inner edge of the reticle 301. The alignment camera assembly 900 captures these marks and aligns them with the alignment marks on the waveguide sheet 101, effectively aligning the reticle 301 with the waveguide sheet. The HUD waveguide sheet is larger than 15 inches.

[0076] Furthermore, the workpiece stage 400 is used to displace the supported light-absorbing element 700 and waveguide 101. The workpiece stage 400 comprises a supporting platform 401, a connecting component 402, and a fixed base 403. A positioning block 02 is provided on the supporting platform 401 for positioning the waveguide 101. The connecting component 402 can be displaced along the x-axis, y-axis, and θ-axis. The workpiece stage 400 must rotate the waveguide 101 for exposure, within an angle range of [0°, 360°]. Therefore, the displacement range of the workpiece stage 400 is the circumscribed circle of the waveguide 101. During exposure, the exposed area B must be displaced to the center of the light spot. With the center of the light spot as a reference, the center of the fixed workpiece stage 400 must coincide with the center of the light spot. The ±x and ±y displacements of the workpiece stage 400 must be greater than the radius of the circumscribed circle of the waveguide 101 minus the light spot radius.

[0077] The reticle 301 is provided with support columns 5014 connected to support rods 5012. This serves to raise the edge of the reticle 301, preventing refractive index matching fluid from seeping onto the reticle 301 surface during waveguide plate 101 movement, potentially destroying the periodic structure and causing exposure failure. The reticle 301 and baffle 2011 can be automatically switched using the switch bracket module 500.

[0078] The number of masks 301 depends on the number of grating regions on the waveguide plate 101, and the number of baffles 2011 depends on the number of exposures of the grating regions. Since the coupling region of the optical waveguide is relatively small and can be completed with a single exposure, the coupling region only needs to be exposed once. Figure 9 The automatic switching of the baffle 2011 is achieved by rotating in the xy plane. In other embodiments, it can also be achieved by rotating in the xz plane or in the zy plane. As the size of the waveguide plate 101 increases, the size of a single grating area also increases. When the specifications of the mask 301 are fixed, the number of exposures of a single grating area increases, and the number of baffles 2011 required increases. The support rods 5012 of the mask 301 and the support rods 5012 of the baffle 2011 need to be lengthened, which increases the volume of the entire device. Therefore, longitudinal rotation can also be used to achieve the automatic switching function of the baffles to reduce the volume of the device. The mask assembly 300 also needs to have a displacement in the z-axis direction to meet the requirement of rapid bonding without large bubbles after the refractive index matching liquid 01 is sprayed on the upper surface of the waveguide plate 101. All of the above-mentioned electric devices are connected to a computer and controlled by software to achieve fully automated preparation of volume holographic HUD optical waveguides.

[0079] Therefore, the exposure equipment is designed with multiple movable platform components and software-controlled, enabling fully automated operation and mass production. The equipment utilizes a top-projection exposure method, with the large waveguide 101 and the smaller mask 301 positioned above, making it easier to operate. The platform on which the waveguide 101 rests is specially treated to achieve exposure results equivalent to bottom-projection exposure. The equipment offers high flexibility and can expose and prepare a variety of waveguides. This overcomes the difficulty in manufacturing HUD optical waveguide components. The equipment features high-precision alignment, resulting in excellent imaging quality for the prepared optical waveguide components.

[0080] In one embodiment, when the waveguide sheet includes multiple areas to be exposed, when the areas to be exposed need to be spliced ​​for exposure, and the baffle module corresponding to the areas to be exposed includes multiple baffles, when the volume holographic waveguide exposure device according to any embodiment of the present invention performs exposure, first, the reflection angle of the reflective element is adjusted so that the exposure beam can meet the incident angle of the area to be exposed of the waveguide sheet; then, the position of the workpiece stage is adjusted so that the center of the area to be exposed moves to the center of the light spot of the exposure beam; then, the liquid nozzle is controlled to open and the refractive index matching liquid is dripped on the waveguide sheet; then, the liquid nozzle corresponding to the area to be exposed is switched. The mask and baffle are located on the transmission path of the exposure beam, so that the periodic grating mask structure of the mask and the light-transmitting area of ​​the baffle correspond to the area to be exposed; then the alignment camera is controlled to collect the alignment mark of the mask and align it with the alignment mark of the waveguide; then the laser switch is controlled to close to form an exposure beam for exposure, and then after the exposure is completed, the laser switch is controlled to disconnect and the baffle is switched; then the baffle switching step, the alignment step and the exposure step are repeated in sequence to complete the splicing exposure of the area to be exposed; then the above steps are repeated in sequence to complete the exposure of each area to be exposed of the waveguide.

[0081] In a specific embodiment, taking the exposure of a 15-inch HUD waveguide as an example, Figure 3 FIG. 1 is a schematic structural diagram of a waveguide sheet to be exposed in the volume holographic optical waveguide exposure device proposed in an embodiment of the present invention. Figure 3 As shown, the waveguide plate 101 is provided with an incoupling region B1, a transition region B2, an outcoupling region B3, and an alignment mark "+". The alignment mark on the waveguide plate 101 needs to avoid the grating area to avoid affecting the formation of the grating during the exposure stage and the light transmission within the waveguide glass, thereby avoiding affecting the imaging effect of the optical waveguide. Figure 14 FIG. 1 is a schematic diagram of a process for preparing a waveguide sheet in a volume holographic optical waveguide exposure device according to a specific embodiment of the present invention. Figure 14 As shown, the rotation angles of the waveguide 101 during exposure of the three grating regions are such that the grating strips of the rotated grating regions are parallel to the xz plane. The incoupling region B1 is typically small and does not require splicing exposure. The grating areas of the transition region B2 and the outcoupling region B3 are larger and require multiple splicing exposures. The principle of splicing is to minimize the number of exposures. Figure 6It is a structural diagram of multiple masks in a mask assembly of the volume holographic optical waveguide exposure device proposed in an embodiment of the present invention, which is divided into three masks according to the three grating areas. Among them, the mask 301 includes a periodic grating mask structure, and an alignment mark "+". The most basic design of a pair of alignment marks is the design on the mask 301, which is symmetrical with the center of the mask 301 on the outer ring of the mask 301. However, if the alignment marks of the mask 301 are all based on the basic design, the alignment marks will appear in the grating area, so the alignment marks that appear in the grating area need to be adjusted. The adjustment principle is to use the center of the circle as the rotation point and rotate to the non-grating area. A certain distance is maintained between a group of alignment marks to ensure alignment accuracy. Such as Figure 6 As shown, different exposure areas may share the same mask alignment mark, or different exposure areas may have designated different mask alignment marks. Figure 2 This is a schematic diagram of the structure of a baffle in the volume holographic optical waveguide exposure device proposed in an embodiment of the present invention; it corresponds to a schematic diagram of the coupling area baffle. Figure 4 This is a schematic diagram of the structure of multiple baffles in a baffle module of the volume holographic optical waveguide exposure device proposed in an embodiment of the present invention, corresponding to a schematic diagram of the turning area baffle. Figure 5 This is a schematic diagram of the structure of multiple baffles in another baffle module of the volume holographic waveguide exposure device proposed in an embodiment of the present invention, corresponding to a schematic diagram of the baffle in the outcoupling area. The gray area is the opaque area, and the white area is the transmissive area.

[0082] First, the coupling region B1 is exposed. The reflector 607 is controlled to adjust the incident angle of the coupling region B1, and the workpiece stage 400 is rotated to the coupling region B1 rotation angle so that the grating direction is parallel to the xz plane. The workpiece stage 400 is moved to move the center of the coupling region B1 to the center of the light spot, and the liquid nozzle is opened to drip the refractive index matching liquid 01. Switch to the mask 301 ( Figure 6 (a) in), baffle 2011( Figure 2 The mask 301 is lowered and the alignment camera 900 is moved to a preset position for alignment. The laser beam switch 602 is turned on for exposure. After the exposure is complete, the workpiece stage 400 is moved to the end of the axis travel, separating the waveguide 101 and the mask 301. The mask 301 is then lifted, completing the exposure of the coupling region B1.

[0083] Next, the turning area B2 is exposed. The reflector 607 is controlled to adjust to the incident angle of the turning area B2, and the workpiece stage 400 is rotated to the turning area B2 rotation angle so that the grating direction is parallel to the xz plane. The workpiece stage 400 is moved to move the center of the turning area B2 to the center of the light spot, and the liquid nozzle is opened to drip the refractive index matching liquid 01. Switch to the mask 301 ( Figure 6(b) in), baffle 2011( Figure 4 (a) in the figure), drop the mask 301 and move the alignment camera 900 to the preset position for alignment. The switch element 602 of the laser beam is exposed. After the exposure is completed, the switch element 602 is closed and the workpiece stage 400 is moved to move the center of the turning area B2 to the center of the light spot. Replace the baffle 2011 ( Figure 4 (b) in the figure), the alignment camera 900 is moved to the preset position for alignment. The switch element 602 of the laser beam is exposed. After the exposure is completed, the switch element 602 is closed. The same steps as in the turning area B2 are followed to replace the baffle 2011 ( Figure 4 (c)-(d)-(e)-(f)) in FIG. 4 completes the exposure of the turning area B2, and then completes the splicing exposure of the turning area B2.

[0084] Expose the outcoupling area B3. Control the reflector 607 to adjust the incident angle of the outcoupling area B3, rotate the workpiece stage 400 to the outcoupling area B3 rotation angle, and make the grating direction parallel to the xz plane. Move the workpiece stage 400 to move the center of the outcoupling area B3 to the center of the light spot, open the liquid nozzle, and drip the refractive index matching liquid 01. Switch to the mask 301 ( Figure 6 (c) in), baffle 2011( Figure 5 (g) in the figure), drop the mask 301, and move the alignment camera 900 to the preset position for alignment. The switch element 602 of the laser beam is exposed. After the exposure is completed, the switch element 602 is closed, and the workpiece stage 400 is moved to move the center of the outcoupling area B3 to the center of the light spot. Replace the baffle 2011 ( Figure 5 (h) in the figure), the alignment camera 900 is moved to the preset position for alignment. The switch element 602 of the laser beam is exposed. After the exposure is completed, the switch element 602 is closed. The same steps as the coupling area B3 are followed to replace the baffle 2011 ( Figure 5 (i)-(j)) in the figure complete the exposure of the out-coupling area B3, and then complete the splicing exposure of the out-coupling area B3.

[0085] In summary, the volume holographic optical waveguide exposure device proposed in accordance with an embodiment of the present invention includes: a baffle assembly, a mask assembly, and a workpiece stage for carrying the waveguide plate to be exposed, which are arranged in sequence along the transmission direction of the exposure beam; the baffle assembly includes a plurality of baffle modules, the baffle module includes at least one baffle, and the baffle includes a light-transmitting area; when the baffle module includes a plurality of baffles, the light-transmitting areas in different baffles have different shapes and / or sizes, and the light-transmitting areas of each baffle in the baffle module can be spliced ​​to form an area to be exposed on the waveguide plate, and the area to be exposed is a coupling-in area, a turning area, or an out-coupling area, and can be switched between different baffle modules and between different baffles of the same baffle module; the mask assembly includes at least one mask, and the mask includes a periodic grating mask structure; wherein, when exposing an area to be exposed of the waveguide plate, the baffle and mask corresponding to the current exposure of the area to be exposed can be simultaneously switched to the transmission path of the exposure beam. Therefore, this technical solution can complete the splicing exposure of the area to be exposed by switching multiple baffles to perform multiple exposures when the area to be exposed is large, and different mask plates can also be switched for different areas to be exposed, which increases the utilization rate of the baffles and mask plates to a certain extent, reduces the cost of making the baffles and mask plates, and can reduce the size of the equipment.

[0086] It should be understood that the various forms of the processes shown above can be used to reorder, add, or delete steps. For example, the steps described in this utility model can be performed in parallel, sequentially, or in a different order, as long as the desired results of the technical solution of this utility model can be achieved. This is not limited herein.

[0087] The above specific embodiments do not limit the scope of protection of this utility model. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model shall be included within the scope of protection of this utility model.

Claims

1. A volume holographic optical waveguide exposure device, characterized in that: include: A baffle assembly, a mask assembly, and a workpiece stage for carrying the exposed waveguide sheet are sequentially arranged along the transmission direction of the exposure beam; The baffle assembly includes a plurality of baffle modules, each of which includes at least one baffle, and each baffle includes a light-transmitting area. When the baffle module includes a plurality of baffles, the light-transmitting areas of different baffles have different shapes and / or sizes. The light-transmitting areas of the baffles in the baffle module can be spliced ​​to form an area to be exposed on the waveguide sheet. The baffle modules can be switched between different modules and between different baffles in the same baffle module. The mask assembly includes at least one mask, which includes a periodic grating mask structure. When exposing an area to be exposed of the waveguide plate, the baffle and mask corresponding to the current exposure of the area to be exposed can be simultaneously switched to the path of the exposure beam transmission.

2. The volume holographic optical waveguide exposure apparatus according to claim 1, wherein: When there are multiple masks, different masks correspond to different areas to be exposed on the waveguide plate, and different masks can be switched; wherein the period and / or shape of the periodic grating mask structure on different masks are different.

3. The volume holographic optical waveguide exposure apparatus according to claim 1, wherein: Also includes: A switching bracket module, the switching bracket module includes at least one bracket unit, the bracket unit includes a support shaft and multiple support rods, one end of the support rod is connected to the support shaft, and the other end is connected to a connector for connecting the baffle and / or the mask; the support rod can rotate around the support shaft.

4. The volume holographic optical waveguide exposure apparatus according to claim 3, wherein: Multiple baffles are located on a first plane, and multiple masks are located on a second plane. The first plane and the second plane are arranged in sequence along the exposure beam transmission direction. The support rod located on the first plane is connected to the connecting piece of the baffle, and the support rod located on the second plane is connected to the connecting piece of the mask.

5. The volume holographic optical waveguide exposure apparatus according to claim 3, wherein: The baffle is fixedly arranged with the mask. The baffle is a light-shielding layer with a light-transmitting area attached to the mask. The support rods are located in the same plane and are connected to the connector of the mask.

6. The volume holographic optical waveguide exposure apparatus according to claim 3, wherein: The baffle module includes at least a first baffle module and a second baffle module, the baffle in the first baffle module is located in a third plane, the baffle in the second baffle module is located in a fourth plane, the mask is located in the second plane, the third plane and the second plane are arranged in sequence along the exposure beam transmission direction, the fourth plane and the second plane are arranged in sequence along the exposure beam transmission direction, and the third plane and the fourth plane are not coplanar.

7. The volume holographic optical waveguide exposure apparatus according to claim 3, wherein: The switching bracket module includes a plurality of bracket units, one of which is used to carry the mask assembly, and the number of the remaining bracket units is the same as that of the baffle modules, and are respectively used to carry the baffles in the corresponding baffle modules.

8. The volume holographic optical waveguide exposure apparatus according to claim 1, wherein: Also includes: a light source module, configured to form the exposure light beam; The light source module includes a laser, a switch element, a beam shaping element, a first beam expanding element, a polarization element, a second beam expanding element, a reflecting element and a light blocking element arranged in sequence along the light transmission direction. The outer diameter of the light blocking element is larger than the diameter of the light spot formed by the exposure beam, and the inner diameter of the light blocking element is smaller than the diameter of the light blocking area of ​​the mask.

9. The volume holographic optical waveguide exposure apparatus according to claim 8, wherein: The reflection angle of the reflection element is adjustable.

10. The volume holographic optical waveguide exposure apparatus according to claim 1, wherein: Also includes: A light absorbing element is located on a side of the waveguide plate away from the mask plate, and is used for absorbing the exposure light beam passing through the waveguide plate.

11. The volume holographic optical waveguide exposure apparatus according to claim 1, wherein: Also includes: A liquid spraying part, comprising a liquid spraying nozzle and a movable shaft, for spraying a refractive index matching liquid onto the upper surface of the waveguide; An alignment camera assembly includes at least one camera to capture the alignment mark on the waveguide plate and align it with the alignment mark on the mask.

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