Volume holographic optical waveguide exposure equipment and method

Abstract

The invention discloses a volume holographic optical waveguide exposure device and method, in the device, a light source module is used for emitting an irradiation beam, and a reflection assembly is used for reflecting the irradiation beam to form an exposure beam; the baffle assembly comprises at least one baffle module, the baffle module comprises at least one baffle, and the baffle comprises a light-transmitting area; the mask assembly at least comprises one mask, and the mask comprises a periodic grating mask structure; the controller is used for controlling the reflection angle of the reflection assembly to the irradiation beam according to the grating parameters of the to-be-exposed area of the waveguide sheet, controlling the movement of the workpiece table according to the position of the exposure beam, and obtaining the model of the baffle plate and the model of the mask plate corresponding to the current exposure of the to-be-exposed area according to the grating parameters. And adjusting the position of the baffle plate and the position of the mask plate according to the position of the exposure light beam so as to expose the to-be-exposed area. The whole exposure equipment can be controlled through the controller, full-automatic execution of exposure is realized, and the efficiency is greatly improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a volume holographic optical waveguide exposure device and method. Background Art

[0002] Augmented Reality (AR) is a new technology that innovates visual experience and human-computer interaction. It is a new technology that "seamlessly" integrates real-world information and virtual-world information. The optical display system of AR devices usually consists of a micro display screen and optical components. Currently, HUD (Head-up-Display) is very popular in the market. The automotive HUD head-up display using AR technology has a larger field of view and a longer imaging distance, a wider field of view, better imaging effects, and good user interactivity.

[0003] At present, the waveguide in AR-HUD is generally a volume holographic waveguide or a surface relief waveguide. Volume holographic waveguides are widely used because they have relative advantages in manufacturing difficulty and cost. However, the problem is that the current volume holographic exposure process mostly uses manual switching of baffles, masks, etc., which makes the exposure efficiency low and the yield rate low. Summary of the invention

[0004] The present invention provides a volume holographic optical waveguide exposure device and method, which can fully automatically expose the waveguide sheet, reducing labor costs, and for exposure areas with larger areas, exposure can be performed by splicing multiple baffles, which improves the exposure efficiency and the utilization rate of the baffles and masks.

[0005] According to one aspect of the present invention, a volume holographic optical waveguide exposure device is provided, comprising: a baffle assembly, a mask assembly, a workpiece stage for carrying an exposed waveguide sheet, a light source module, a reflection assembly and a controller, which are sequentially arranged along the transmission direction of the exposure beam;

[0006] The light source module is used to emit an irradiation beam, and the reflection assembly is used to reflect the irradiation beam to form an exposure beam; the baffle assembly includes at least one baffle module, and the baffle module includes at least one baffle, and the baffle includes a light-transmitting area; the mask assembly includes at least one mask, and the mask includes a periodic grating mask structure;

[0007] The controller is respectively connected to the baffle assembly, the mask assembly, the workpiece stage and the reflection assembly. The controller is used to control the reflection angle of the reflection assembly to the irradiation light beam according to the grating parameters of the area to be exposed of the waveguide plate, so as to adjust the incident angle of the exposure light beam to the area to be exposed; the controller is also used to control the movement of the workpiece stage according to the position of the exposure light beam, so as to adjust the area to be exposed to the center position of the light spot of the exposure light beam; the controller is also used to obtain the baffle model and the mask model corresponding to the current exposure of the area to be exposed according to the grating parameters, and adjust the baffle position and the mask position according to the position of the exposure light beam to expose the area to be exposed.

[0008] Optionally, the baffle module includes at least one baffle;

[0009] When there is one baffle, the light-transmitting area of ​​the baffle corresponds to an area to be exposed on the waveguide plate;

[0010] When there are multiple baffles, the light-transmitting areas in different baffles have different shapes and / or sizes, and 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.

[0011] Optionally, the waveguide sheet includes a coupling-in region and a coupling-out region, or further includes a turning region, and the region to be exposed is any one of the coupling-in region, the coupling-out region or the turning region; each of the baffle modules is arranged corresponding to the region to be exposed;

[0012] Among them, the baffle module corresponding to the coupling-in area includes a baffle; the baffle module corresponding to the turning area or the coupling-out area includes multiple baffles, and the turning area or the coupling-out area is divided into multiple sub-exposure areas before exposure, and the shapes of the light-transmitting areas of the multiple baffles in the corresponding baffle module correspond to the shapes of the sub-exposure areas.

[0013] 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, wherein the periods and / or shapes of the periodic grating mask structures on different masks are different.

[0014] Optionally, the volume holographic waveguide exposure equipment also includes: a switching bracket module, the switching bracket module includes at least one bracket unit, the bracket unit includes a support shaft and a plurality of support rods, one end of the support rod is connected to the support shaft, and the other end is connected to a connecting piece for connecting the baffle and / or the mask, and the support rod can rotate around the support shaft.

[0015] Optionally, multiple baffles are located on a first plane, multiple masks are located on a second plane, the first plane and the second plane are arranged sequentially 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.

[0016] 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 with the connector of the mask.

[0017] 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.

[0018] 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 the number of the baffle modules, and are respectively used to carry baffles in the corresponding baffle modules.

[0019] Optionally, the light source module includes a laser, a switch element, a beam shaping element, a first beam expanding element, a polarization element, and a second beam expanding element, which are sequentially arranged along the light transmission direction;

[0020] The reflective assembly comprises a reflective element and a light blocking element, the outer diameter of the light blocking element is larger than the diameter of the light spot formed by the exposure light beam, and the inner diameter of the light blocking element is smaller than the diameter of the light blocking area of ​​the mask.

[0021] 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 for absorbing the exposure light beam passing through the waveguide plate.

[0022] Optionally, the volume holographic optical waveguide exposure equipment further comprises: an alignment camera assembly, wherein the alignment camera assembly comprises at least one camera for capturing an alignment mark on the waveguide sheet and aligning the alignment mark on the mask.

[0023] According to another aspect of the present invention, a method for exposing a volume holographic optical waveguide is provided. The method is performed based on the volume holographic optical waveguide exposure device according to any embodiment of the present invention. The method comprises the following steps:

[0024] Acquire the grating parameters of the area to be exposed of the waveguide plate, and control the reflection angle of the reflection component to the irradiation light beam according to the grating parameters of the area to be exposed of the waveguide plate, so as to adjust the incident angle of the exposure light beam to the area to be exposed;

[0025] Acquiring the position of the exposure beam, and controlling the movement of the workpiece stage according to the position of the exposure beam to adjust the position of the area to be exposed to the exposure beam;

[0026] The baffle model and mask model corresponding to the current exposure of the area to be exposed are obtained according to the grating parameters, and the baffle position and the mask position are adjusted according to the position of the exposure beam to expose the area to be exposed.

[0027] According to the volume holographic optical waveguide exposure device and method proposed in the embodiment of the present invention, the device includes a baffle assembly, a mask assembly, a workpiece stage for carrying the exposed waveguide plate, a light source module, a reflection assembly and a controller which are sequentially arranged along the transmission direction of the exposure beam; the light source module is used to emit an irradiation beam, and the reflection assembly is used to reflect the irradiation beam to form an exposure beam; the baffle assembly includes at least one baffle module, the baffle module includes at least one baffle, and the baffle includes a light-transmitting area; the mask assembly includes at least one mask, and the mask includes a periodic grating mask structure; the controller is respectively connected to the baffle assembly, the mask, and the controller. The controller is used to control the reflection angle of the irradiation light beam of the reflective component according to the grating parameters of the area to be exposed of the waveguide plate, so as to adjust the incident angle of the exposure light beam to the area to be exposed; the controller is also used to control the movement of the workpiece stage according to the position of the exposure light beam, so as to adjust the area to be exposed to be located at the center position of the light spot of the exposure light beam; the controller is also used to obtain the model of the baffle and the model of the mask corresponding to the current exposure of the area to be exposed according to the grating parameters, and adjust the position of the baffle and the position of the mask according to the position of the exposure light beam, so as to expose the area to be exposed.

[0028] Therefore, in this technical solution, the entire exposure equipment can be controlled by the controller to realize fully automated execution of exposure, and the efficiency is greatly improved. And when the area to be exposed is large, multiple exposures can be performed by switching multiple baffles to complete the splicing exposure of the area to be exposed, and different masks can also be switched for different areas to be exposed, which increases the utilization rate of baffles and masks to a certain extent, reduces the cost of making baffles and masks, and can reduce the size of the equipment.

[0029] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they 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

[0030] 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 creative work.

[0031] Figure 1 is a schematic structural diagram of a volume holographic optical waveguide exposure device proposed in an embodiment of the present invention;

[0032] Figure 2 It is a schematic structural diagram of a baffle in a volume holographic optical waveguide exposure device proposed in an embodiment of the present invention;

[0033] Figure 3 It is a schematic structural diagram of a waveguide sheet to be exposed in a volume holographic optical waveguide exposure device provided in an embodiment of the present invention;

[0034] Figure 4 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;

[0035] Figure 5 is a schematic structural diagram of multiple baffles in another baffle module of a volume holographic optical waveguide exposure device provided in an embodiment of the present invention;

[0036] Figure 6 It 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;

[0037] Figure 7 It is a structural schematic diagram of a switching support module in a volume holographic optical waveguide exposure device proposed in an embodiment of the present invention;

[0038] Figure 8 It is a structural schematic diagram of another switching support module in the volume holographic optical waveguide exposure device proposed in an embodiment of the present invention;

[0039] Fig. 9 It is a structural schematic diagram of another switching support module in the volume holographic optical waveguide exposure device proposed in an embodiment of the present invention;

[0040] Fig.10 2 is a schematic structural diagram of a light source module in a volume holographic optical waveguide exposure device according to an embodiment of the present invention;

[0041] Fig.11 2 is a schematic structural diagram of a middle light blocking element of a volume holographic optical waveguide exposure device provided in an embodiment of the present invention;

[0042] Fig.12 is a schematic structural diagram of a volume holographic optical waveguide exposure device proposed in a specific embodiment of the present invention;

[0043] Fig.13 is a schematic structural diagram of another viewing angle of a volume holographic optical waveguide exposure device proposed in a specific embodiment of the present invention;

[0044] Fig.14 It is a schematic diagram of the process of preparing the waveguide plate part in the volume holographic optical waveguide exposure device proposed in a specific embodiment of the present invention. DETAILED DESCRIPTION

[0045] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments 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 creative work should fall within the scope of protection of the present invention.

[0046] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0047] In the related art, the volume holographic optical waveguide generally includes a coupling region, a turning region and a coupling-out region, or includes a coupling-in region and a coupling-out region. The coupling-in region is used to couple external light carrying image information into the volume holographic optical waveguide, the turning region is used to propagate and expand the coupled external light, and the coupling-out region is also used to couple the light in the volume holographic optical waveguide to form a coupling-out light field for the human eye to receive, so as to observe the relevant image information. Among them, the area of ​​the coupling-in region is generally small, and the corresponding mask and baffle can be used for exposure. However, the area of ​​the turning region and the coupling-out region is generally large. If a baffle is used for exposure, a baffle with a larger area needs to be made. And when the shape and contour of the turning region or the coupling-out region changes, the baffle cannot be reused, resulting in a waste of resources. In addition, in the related art, during the exposure process, the baffle and the mask have always been switched manually, which has high labor costs and low exposure efficiency. The controller automatically exposes the waveguide sheet, which improves the exposure efficiency.

[0048] Based on the above content, the embodiment of the present invention proposes a volume holographic optical waveguide exposure device and method, which can control the entire exposure device through a controller, realize fully automated execution of exposure, and greatly improve efficiency. And when the area of ​​a to-be-exposed area is large, it is also possible to complete the splicing exposure of the to-be-exposed area by switching multiple baffles for multiple exposures, and different masks can also be switched for different to-be-exposed areas, which increases the utilization rate of baffles and masks to a certain extent, reduces the cost of making baffles and masks, and can reduce the size of the equipment.

[0049] Figure 1 FIG. 1 is a schematic diagram of the structure of a volume holographic optical waveguide exposure device according to an embodiment of the present invention. Figure 1 As shown, the volume holographic optical waveguide exposure device 100 comprises: a baffle assembly 200, a mask assembly 300, a workpiece stage 400 for carrying the exposed waveguide sheet 101, a light source module 600, a reflection assembly 60 and a controller which are sequentially arranged along the transmission direction of the exposure beam;

[0050] The light source module 600 is used to emit an irradiation beam, and the reflection component 60 is used to reflect the irradiation beam to form an exposure beam; the baffle assembly 200 includes a plurality of baffle modules 201, and the baffle module 201 includes at least one baffle 2011, and the baffle 2011 includes a light-transmitting area A; the mask assembly 300 includes at least one mask 301, and the mask 301 includes a periodic grating mask structure;

[0051] The controller is respectively connected to the baffle assembly 200, the mask assembly 300, the workpiece stage 400 and the reflection assembly 60. The controller is used to control the reflection angle of the reflection assembly 60 to the irradiation light beam according to the grating parameters of the area to be exposed of the waveguide plate 101, so as to adjust the incident angle of the exposure light beam incident on the area to be exposed; the controller is also used to control the movement of the workpiece stage 400 according to the position of the exposure light beam, so as to adjust the area to be exposed to the center position of the light spot of the exposure light beam; the controller is also used to obtain the model of the baffle 2011 and the mask 301 corresponding to the current exposure of the area to be exposed according to the grating parameters, and adjust the position of the baffle 2011 and the mask 301 according to the position of the exposure light beam, so as to expose the area to be exposed.

[0052] Among them, reference Figure 1 , the waveguide sheet 101 can form a volume holographic optical waveguide after exposure. The waveguide sheet 101 in this embodiment can be a HUD waveguide sheet, and the structure can be a volume holographic material sandwiched between two layers of glass. During the exposure of the waveguide sheet 101, the mask 301 is located on the side close to the waveguide sheet 101, and the projection of the mask 301 on the plane where the waveguide sheet 101 is located at least partially overlaps with the waveguide sheet 101. The mask 301 is provided with a periodic grating mask structure. Through exposure, the pattern corresponding to the periodic grating mask structure on the mask 301 can be transferred to the volume holographic material. The baffle 2011 is located on the side of the mask 301 away from the waveguide sheet 101, that is, the mask 301 is located between the baffle 2011 and the waveguide sheet 101. The projection of the baffle 2011 on the plane where the waveguide sheet 101 is located at least partially overlaps with the mask 301 and the waveguide sheet 101 at the same time. Figure 2 FIG. 1 is a schematic diagram of a baffle in a volume holographic optical waveguide exposure device according to an embodiment of the present invention, with reference to FIG. 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 irradiate the mask plate 301 , thereby transferring the pattern of the periodic grating mask structure on the mask plate 301 to the waveguide plate 101 .

[0053] It is understandable that, since the areas to be exposed on the waveguide sheet 101 are different, the baffles 2011 and the mask plates 301 to be used may also be different. Therefore, the correspondence between the grating parameters of the area to be exposed and the style (shape or size) of the baffle 2011, the style of the mask plate 301 (related parameters of the periodic grating mask structure) and the exposure angle of the exposure beam can be input in advance in the controller of the device. When the waveguide sheet 101 is exposed, the corresponding baffle 2011, the mask plate 301 and the exposure angle of the exposure beam (the reflection angle of the reflection component 60 can be controlled) can be called through the correspondence. Based on the adjusted position of the exposure beam, the positions of the baffle 2011, the mask plate 301 and the workpiece stage 400 are adjusted so that the center of the area to be exposed can be located at the center of the light spot of the exposure beam, thereby realizing exposure of the area to be exposed.

[0054] It should be noted that the grating parameters include the shape of the area to be exposed and the period, arrangement direction, diffraction angle, etc. of the grating structure. The waveguide plate 101 generally needs to be exposed to form a coupling region and an outcoupling region, or to form a coupling region, an outcoupling region and a turning region. The outer contour shape of the coupling region corresponds to the model of a baffle, the period and arrangement direction of the grating structure of the coupling region correspond to the model of a mask, and the diffraction angle of the coupling region corresponds to the incident angle of the exposure beam. The outcoupling region and the turning region are similar to the coupling region, and will not be repeated here.

[0055] Optionally, the baffle module 201 includes at least one baffle 2011; when there is one baffle 2011, the light-transmitting area A of the baffle 2011 corresponds to an area to be exposed on the waveguide plate 101; when there are multiple baffles 2011, the shapes and / or sizes of the light-transmitting areas A in different baffles 2011 are different, and the light-transmitting areas A of each baffle 2011 in the baffle module 201 can be spliced ​​to form an area to be exposed on the waveguide plate 101.

[0056] The light transmittance of the baffle 2011 in the exposure area is 100%, and the light transmittance in the non-exposure area is 0%, so as to obtain a single exposure target pattern. The material of the baffle 2011 is not limited, as long as the transmittance in the laser band is 0%; the thickness of the baffle 2011 needs to be less than 0.1 mm to reduce the edge diffraction effect of the grating.

[0057] It can be understood that one baffle module 201 corresponds to one area B to be exposed. When the area of ​​the area B to be exposed is large, the baffle module 201 may include multiple baffles 2011, and the light-transmitting areas A in different baffles 2011 have different shapes and / or sizes. The light-transmitting areas A of each baffle 2011 in the baffle module 201 can be spliced ​​to form an area B to be exposed on the waveguide sheet 101. The area B to be exposed is the coupling-in area B1, the turning area B2 or the out-coupling area B3. Different baffle modules 201 and different baffles 2011 in the same baffle module 201 can be switched. In this way, the utilization rate of the baffles 2011 can be improved. In one embodiment, the baffles 2011 in different baffle modules 201 can be overlapped or used crosswise. For example, part of the baffles 2011 in the baffle module 201 corresponding to the turning area B2 can also be applied to the out-coupling area B3, or to the turning area B2 in the next waveguide sheet 101.

[0058] Optionally, the waveguide plate 101 includes a coupling-in region B1 and a coupling-out region B3, or further includes a turning region B2, and the area B to be exposed is any one of the coupling-in region B1, the coupling-out region B3 or the turning region B2; each baffle module 201 is arranged corresponding to the area B to be exposed;

[0059] Among them, the baffle module 201 corresponding to the coupling-in area B1 includes a baffle 2011; the baffle module 201 corresponding to the turning area B2 or the coupling-out area B3 includes multiple baffles 2011, and the turning area B2 or the coupling-out area B3 is divided into multiple sub-exposure areas before exposure. The shape of the light-transmitting area A of the multiple baffles 2011 in the corresponding baffle module 201 corresponds to the shape of the sub-exposure area.

[0060] It should be noted that Figure 3 FIG. 1 is a schematic structural diagram of a waveguide sheet to be exposed in a volume holographic optical waveguide exposure device according to an embodiment of the present invention, with reference to FIG. Figure 3 When exposing the waveguide sheet 101, the to-be-exposed region B of the waveguide sheet 101 needs to be exposed, that is, the coupling-in region B1, the turning region B2, and the coupling-out region B3 need to be exposed to form a volume holographic optical waveguide. In other embodiments, the to-be-exposed region B of the waveguide sheet 101 may also include only the coupling-in region B1 and the coupling-out region B3.

[0061] The baffle module 201 corresponds to the area B to be exposed on the waveguide plate 101, that is, when the coupling-in area B1 is exposed, the baffle 2011 in the baffle module 201 corresponding to the coupling-in area B1 is used; when the turning area B2 is exposed, the baffle 2011 in the baffle module 201 corresponding to the turning area B2 is used; when the coupling-out area B3 is exposed, the baffle 2011 in the baffle module 201 corresponding to the coupling-out area B3 is used. Since the area of ​​the coupling-in area B1 is generally small, the baffle 2011 in the baffle module 201 corresponding to it can be one (such as Figure 2 As shown in FIG. 1 ). Since the areas of the turning region B2 and the coupling-out 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 FIG. 2 , there are multiple baffles 2011 corresponding to the sub-exposure areas in the turning area B2, such as Figure 5 , which are multiple baffles 2011 corresponding to the sub-exposure areas in 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, wherein: Figure 4 The 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.

[0062] It can be understood that the splicing contour of the light-transmitting area A of each baffle 2011 in the same baffle module 201 is the same as the contour of the corresponding area to be exposed B. The shape and / or size of the light-transmitting area A of each baffle 2011 are different, and the shape and / or size of the light-transmitting area A of each baffle can be considered based on the contour of the corresponding area to be exposed B, and the adaptability of the contour of other exposure areas on the substrate to be exposed and the light-transmitting area A of a single baffle, so as to increase the utilization rate of each baffle 2011.

[0063] 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; wherein the period and / or shape of the periodic grating mask structure on different masks 301 are different.

[0064] If the periodic grating mask structures required for each area B to be exposed on the waveguide sheet 101 are the same, then the mask 301 in the mask assembly 300 can be one. If the periodic grating mask structures required for each area B to be exposed on the waveguide sheet 101 are the same but at different angles, then the mask 301 in the mask assembly 300 can be one. During exposure, the workpiece stage 400 can be controlled to adjust the position of the waveguide sheet 101 so that the waveguide sheet 101 and the periodic grating mask structure on the mask 301 have a corresponding angle.

[0065] However, 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 (eg, Figure 6 The masks shown in FIG. 3 correspond to different to-be-exposed areas B of the waveguide plate 101 , respectively. In this way, the same mask 301 has only one periodic grating mask structure, which increases the utilization rate of the mask 301 .

[0066] 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.

[0067] Optionally, Figure 7 is a structural schematic diagram of a switching support module in a volume holographic optical waveguide exposure device proposed in an embodiment of the present invention; Figure 7 As shown, the volume holographic waveguide exposure device 100 also includes: a switching bracket module 500, the switching bracket module 500 includes at least one bracket unit 501, the bracket unit 501 includes 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; the support rod 5012 can rotate around the support shaft 5011.

[0068] It can be 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.

[0069] Wherein, when the other end of the support rod 5012 is connected to the connecting piece of the baffle 2011 and / or the mask 301, the connecting end of the support rod 5012 can be provided with a connecting piece that can be connected and used in conjunction with the connecting piece of the baffle 2011 and / or the mask 301, such as a buckle or a lock, etc. For example, the support rod 5012 is provided with a first connecting piece, and the baffle and / or the mask 301 are provided with a second connecting piece, and the first connecting piece and the second connecting piece can be connected in conjunction, so that the support rod 5012 can be connected to the baffle and / or the mask 301. In one embodiment, the first connecting piece provided on the support rod 5012 can rotate on the support rod 5012, so that the angle of the baffle 2011 and / or the mask 301 connected thereto relative to the support rod 5012 can also be adjusted.

[0070] The mask 301 in the bracket unit 501 is arranged closer to the waveguide 101, and the baffle 2011 is arranged closer to the mask 301 and farther from the waveguide 101. Along the exposure beam transmission direction z, the plurality of support rods 5012 can be divided into upper and lower parts, the upper part is used to support the baffle 2011, and the lower part is used to support the mask 301. The support rods 5012 of each part can be arranged in an outwardly radiating manner 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 mask 301 can be switched to the exposure beam transmission direction z by switching and controlling the bracket unit 501.

[0071] Optionally, a plurality of baffles 2011 are located on a first plane, a plurality of masks 301 are located on a second plane, and the first plane and the second plane are sequentially arranged along the exposure beam transmission direction z. The support rod located on the first plane is connected to the connecting piece of the baffle 2011, and the support rod 5012 located on the second plane is connected to the connecting piece of the mask 301.

[0072] That is, all the baffles 2011 are located in the same plane, and all the masks 301 are located in the same plane. The number of baffle modules 201 corresponds to the number of the to-be-exposed areas B on the waveguide plate 101, that is, the baffles 2011 in all the baffle modules 201 are located in the same plane, and all the masks 301 are located in the same plane. This embodiment is suitable for the case where the number of baffles 2011 and the number of masks 301 are small.

[0073] Optionally, the baffle 2011 is fixedly arranged with 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 with the connecting piece of the mask 301 .

[0074] Among them, two support pillars 5014 (such as Fig.12As shown), the support rod 5012 is snap-connected with the support column 5014, the baffle 2011 is attached to the mask plate 301, and the support rods 5012 are all located in the same plane and are connected to the mask plate 301, which can reduce the height of the bracket unit 501 and reduce the volume of the bracket unit 501.

[0075] Optionally, Figure 8 is a structural schematic diagram of another switching support module in the volume holographic optical waveguide exposure device proposed in an embodiment of the present invention; Figure 8 As shown, 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 plate 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.

[0076] The switching support module 500 may include a support unit 501. When the number of baffles 2011 and the number of masks 301 are large, a plurality of support rods 5012 may be arranged in layers along the exposure beam transmission direction z to arrange the baffles 2011 and the masks 301 in multiple layers. The bottom layer where the baffles 2011 are arranged is located above the top layer where the masks 301 are arranged. In addition, in order to ensure the spacing between the baffles 2011 and the masks 301 during exposure, in this embodiment, the support rods 5012 may be configured to be retractable and have a certain angle with the support shaft 5011, similar to an umbrella-shaped support structure. In this way, the positions of the baffles 2011 and / or masks 301 can be adjusted more flexibly.

[0077] In one embodiment, the number of baffle modules 201 corresponds to the number of the to-be-exposed regions B on the waveguide sheet 101, and the baffles 2011 in different baffle modules 201 are arranged in different planes, that is, 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 also 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.

[0078] In one embodiment, there may be multiple support units 501, and the baffle module 201 and the mask 301 in each support unit 501 correspond to one of the to-be-exposed areas B. Alternatively, one support unit 501 is provided with the mask assembly 300, and another support unit 501 is provided with the baffle assembly 200. Alternatively, one support unit 501 is provided with the mask assembly 300, and different support units 501 are provided with different baffle modules 201.

[0079] Optionally, Fig. 9 is a structural schematic diagram of another switching support module in the volume holographic optical waveguide exposure device proposed in an embodiment of the present invention; Fig. 9 As shown, the switching bracket module 500 includes a plurality of 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 the number of the baffle modules 201 , and are respectively used to carry the baffles 2011 in the corresponding baffle modules 201 .

[0080] 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 bracket unit 501 (support shaft 5011 and support rod 5012), the second baffle module 201B is supported by a bracket unit 501 (support shaft 5011 and support rod 5012), and the mask assembly 300 is supported by a bracket unit 501 (support shaft 5011 and support rod 5012). Fig. 9 As shown, three bracket units 501 are arranged in a tree structure. For the outcoupling area or the turning area, since a mask plate 301 generally needs to be adapted to multiple baffles 2011, the length of the support rod 5012 (the bold black line in the figure) in the bracket unit 501 carrying the mask plate assembly 300 is longer than the length of the support rod 5012 (the thinner black line in the figure) carrying the baffle module 201, which is convenient for switching, and only two layers of baffles 2011 and mask plates 301 are set along the exposure beam transmission direction z. With this arrangement, it is easier to meet the exposure spacing between the two.

[0081] Fig.10 2 is a schematic structural diagram of a light source module in a volume holographic optical waveguide exposure device according to an embodiment of the present invention; Fig.11 is a schematic structural diagram of a light blocking element in a volume holographic optical waveguide exposure device according to an embodiment of the present invention; optionally, Fig.10 and Fig.11As shown, the light source module 600 includes a laser 601, a switch element 602, a beam shaping element 603, a first beam expanding element 604, a polarization element 605, and a second beam expanding element 606 arranged in sequence along the light transmission direction; the reflection component 60 includes a reflection element 607 and a light blocking element 608, the outer diameter of the light blocking element 608 is larger than the diameter of the 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.

[0082] Among them, the laser 601 is used to emit a laser beam, and the light-opening element 602 can be an electrically controlled switch, which is located on the path of the laser beam transmission and is used to cut off or conduct the transmission of the laser beam to control the laser exposure time. The beam shaping element 603 can be a flat-top beam shaper, which is used to convert a Gaussian beam into a flat-top beam and play a role in homogenizing the beam. The first beam expansion element 604 is a primary beam expansion device, which is used to initially expand the light spot, and the beam expansion multiple range is 8-12 times. The polarization element 605 is a device for adjusting the polarization direction of the polarized light spot, which can be a half-wave plate. The second beam expansion element 606 is a secondary beam expansion device, which continues to expand the light spot to the target size. It can be a combination of a spatial filter and a large-size convex lens, or a combination of a convex lens, an aperture and a large-size convex lens, or a combination of a concave lens, an aperture and a large-size convex lens. The reflective element 607 is a reflector, which is used for turning the light path and hitting the light spot on the workpiece stage 400 at a corresponding exposure angle. The workpiece stage 400 is used to place the waveguide sheet 101 and perform a series of 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.

[0083] Fig.12 FIG. 1 is a schematic structural diagram of a volume holographic optical waveguide exposure device according to a specific embodiment of the present invention; Fig.11 and Fig.12 As shown, the light blocking element 608 is annular (i.e., Fig.11 The light transmittance is 0%. 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 mask 301, so that the exposure beam L can be prevented from irradiating other areas, so as to ensure that the exposure beam L can be irradiated to the light-transmitting area A of the baffle 2011 and the periodic grating mask structure of the mask 301. Furthermore, after the light spot passes through the light blocking element 608, the baffle 2011, and the mask 301, the pattern of the waveguide plate 101 after exposure is the target pattern, and no stray light exposure pattern will be generated.

[0084] Optionally, Fig.12 FIG. 1 is a schematic structural diagram of a volume holographic optical waveguide exposure device according to a specific embodiment of the present invention; Fig.12 As shown, the reflection angle of the reflection element 607 is adjustable.

[0085] Among them, the reflective element 607 can be a reflector, and 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, and the displacement direction moves along the y-axis; and a Φ-angle electrically controlled rotating stage, which rotates in the yz plane. The angle of the light spot incident on the mask is adjusted by adjusting the rotation angle of the reflector, and then the inclination 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 rotating stage can achieve only changing the inclination angle of the light spot without changing the position of the center of the light spot after reflection, which greatly reduces the design complexity of the carrier platform.

[0086] Optionally, continue to refer to Fig.12 The volume holographic optical waveguide exposure device 100 further includes: a light absorbing element 700, which is located on the side of the waveguide plate 101 away from the mask plate 301 and is used to absorb the exposure light beam passing through the waveguide plate. The absorption rate of the material of the light absorbing element 700 in the laser band is greater than 95%, and the size of the light absorbing element 700 is equivalent to that of the HUD waveguide plate 101. In addition, a prism-type irregular glass device can be selected to conduct the light from the lower surface of the waveguide plate 101, so that the light will not be reflected back to the waveguide plate 101 to affect the exposure.

[0087] Continue to refer Fig.12 and Fig.13 The volume holographic optical waveguide exposure device 100 also includes: a liquid spraying part 800, which includes a liquid spraying nozzle and a movable axis. Its function is to spray the refractive index matching liquid 01 on the upper surface of the waveguide plate 101, and to spray the refractive index matching liquid 01 after replacing the mask plate 301. Its refractive index matches the refractive index of the waveguide plate 101 and the mask plate 301, which helps the light conduction. The movable area of ​​the fixed axis of the liquid spraying nozzle is within the range of the waveguide plate 101, and the displacement destination point of a single exposure is the center of the mask plate 301. The single liquid output is sufficient to fill the contact area between the mask plate 301 and the waveguide plate 101 with the refractive index matching liquid 01. The liquid spraying method is not limited, and can be piezoelectric or pneumatic.

[0088] Optionally, the volume holographic optical waveguide exposure device 100 also includes: an alignment camera component 900, which includes a group of lenses for alignment; it is movable, and after the alignment is completed, the alignment camera component can be moved away and moved to the outside of the carrying platform to avoid affecting the exposure. The movable area of ​​the movable arm of the alignment camera is the outer ring area of ​​the mask 301. The inner side of the edge of the mask 301 is engraved with an alignment mark, and the alignment mark can be collected by the alignment camera component 900 to correspond to the alignment mark on the waveguide sheet 101, so as to realize the alignment of the mask 301 and the waveguide sheet 101. The size of the HUD waveguide sheet is greater than 15 inches.

[0089] In addition, the work stage 400 is used to displace the light absorbing element 700 and the waveguide 101 carried by the work stage 400, wherein the work stage 400 includes a carrying platform 401, a connecting component 402 and a fixed base 403, wherein a positioning block 02 is provided on the carrying platform 401 for positioning the waveguide 101. The connecting component 402 can be displaced in the x-axis, y-axis and θ-angle rotation. The work stage 400 needs to drive the waveguide 101 to rotate for exposure, and the rotation angle range is [0°, 360°]. Therefore, the displacement area of ​​the work stage 400 is the circumscribed circle of the waveguide 101. When exposing, the area B to be exposed needs to be displaced to the center of the light spot. With the center of the light spot as the reference, the center of the fixed work stage 400 coincides with the center of the light spot, and the ±x and ±y displacement strokes of the work stage 400 need to be greater than the radius of the circumscribed circle of the waveguide 101 - the radius of the light spot.

[0090] The mask 301 is provided with a support column 5014 connected to the support rod 5012, which is used to heighten the edge of the mask 301 to prevent the refractive index matching liquid from penetrating into the upper surface of the mask 301 when the waveguide plate 101 moves, thereby destroying the periodic structure and causing exposure failure. The mask 301 and the baffle 2011 can be automatically switched by switching the bracket module 500.

[0091] 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 exposure times of the grating regions. Since the coupling region of the optical waveguide is small, it can be completed by one exposure, so the coupling region only needs to be exposed once. Fig. 9The automatic switching mode of the baffle 2011 is realized by rotating in the xy plane. In other embodiments, it can also be realized by rotating in the xz plane, or it can be realized by rotating 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 plate 301 are fixed, the number of exposure times of a single grating area increases, the number of baffles 2011 required increases, the support rods 5012 of the mask plate 301 and the support rods 5012 of the baffle 2011 need to be lengthened, and the volume of the entire device increases. Therefore, longitudinal rotation can also be used to realize the automatic switching function of the baffle to reduce the volume of the device. The mask plate 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, which can realize the fully automated preparation of volume holographic HUD optical waveguides.

[0092] Therefore, the exposure equipment is designed with a variety of movable bearing platform components, configured with software operation, and fully automated operation, which can be mass-produced. The equipment adopts the top projection exposure method, the waveguide sheet 101 is of large size, the mask plate 301 is of small size, the small size is on the top, and the large size is on the bottom, which is easier to operate. And the platform on which the waveguide sheet 101 is placed is specially treated to make the exposure effect equivalent to the bottom projection exposure method. The equipment is highly flexible and can be used to expose and prepare a variety of waveguide sheets. It solves the disadvantage of HUD optical waveguide devices being difficult to manufacture. The equipment has high-precision alignment, and the prepared optical waveguide devices have excellent imaging effects.

[0093] The present invention further provides a volume holographic optical waveguide exposure method, which is based on the volume holographic optical waveguide exposure device of any embodiment of the present invention for exposure, and the exposure method comprises the following steps:

[0094] Obtaining grating parameters of the area B to be exposed of the waveguide plate 101, and controlling the reflection angle of the reflection component 60 to the irradiation light beam according to the grating parameters of the area B to be exposed of the waveguide plate 101, so as to adjust the incident angle of the exposure light beam to the area B to be exposed;

[0095] Acquire the position of the exposure beam, and control the movement of the workpiece stage 400 according to the position of the exposure beam to adjust the area B to be exposed to the position of the exposure beam;

[0096] The model of the baffle 2011 and the model of the mask 301 corresponding to the current exposure of the area B to be exposed are obtained according to the grating parameters, and the position of the baffle and the mask are adjusted according to the position of the exposure beam to expose the area B to be exposed.

[0097] It is understandable that, since the areas to be exposed on the waveguide sheet 101 are different, the baffles 2011 and the mask plates 301 to be used may also be different. Therefore, the correspondence between the grating parameters of the area to be exposed and the style (shape or size) of the baffle 2011, the style of the mask plate 301 (related parameters of the periodic grating mask structure) and the exposure angle of the exposure beam can be input in advance in the controller of the device. When the waveguide sheet 101 is exposed, the corresponding baffle 2011, the mask plate 301 and the exposure angle of the exposure beam (the reflection angle of the reflection component 60 can be controlled) can be called through the correspondence. Based on the adjusted position of the exposure beam, the positions of the baffle 2011, the mask plate 301 and the workpiece stage 400 are adjusted so that the center of the area to be exposed can be located at the center of the light spot of the exposure beam, thereby realizing exposure of the area to be exposed.

[0098] It should be noted that the grating parameters include the shape of the area B to be exposed and the period, arrangement direction, diffraction angle, etc. of the grating structure. The waveguide plate 101 generally needs to be exposed to form the coupling-in area B1 and the coupling-out area B3, or to form the coupling-in area B1, the coupling-out area B3 and the turning area B2. The outer contour shape of the coupling-in area B1 corresponds to the model of a baffle, the period and arrangement direction of the grating structure of the coupling-in area B1 correspond to the model of a mask, and the diffraction angle of the coupling-in area B1 corresponds to the incident angle of the exposure beam. The coupling-out area B3 and the turning area B2 are similar to the coupling-in area B1, and will not be described in detail here.

[0099] Specifically, when exposing an area to be exposed, first adjust the reflection angle of the reflective element so that the exposure light beam can meet the incident angle of the area to be exposed of the waveguide; then adjust the position of the worktable so that the center of the area to be exposed moves to the center of the light spot of the exposure light beam; then control the liquid spray nozzle to open and drip the refractive index matching liquid on the waveguide; then switch the mask and baffle corresponding to the area to be exposed to be located on the transmission path of the exposure light 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; control the alignment camera to collect the alignment mark of the mask and align it with the alignment mark of the waveguide; control the laser switch to close, form an exposure beam, and perform exposure. After the exposure is completed, control the laser switch to disconnect and switch the baffle; repeat the baffle switching step, the alignment step and the exposure step in sequence to complete the splicing exposure of the area to be exposed; repeat the above steps in sequence to complete the exposure of each area to be exposed of the waveguide.

[0100] More specifically, 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 a volume holographic optical waveguide exposure device according to an embodiment of the present invention. Figure 3As shown, the waveguide plate 101 is provided with a coupling-in area B1, a turning area B2, a coupling-out area 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 in the exposure stage and the light conduction inside the waveguide glass, thereby avoiding affecting the imaging effect of the optical waveguide. Fig.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. Fig.14 As shown in FIG. 1 , the rotation angle of the waveguide plate 101 during the exposure of the three grating regions is such that the grating strip direction of the rotated grating region is parallel to the xz plane. The area of ​​the coupling-in region B1 is usually small, and no splicing exposure is required. The grating areas of the turning region B2 and the coupling-out region B3 are large, and multiple splicing exposures are required. The splicing principle is to minimize the number of exposures. Figure 6 It is a schematic diagram of the structure of multiple masks in a mask assembly of a volume holographic optical waveguide exposure device proposed in an embodiment of the present invention, which is divided into three masks according to 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 on the outer ring of the mask 301, symmetrical with the center of the mask 301. However, if the alignment marks of the mask 301 are all designed in the basic way, the alignment marks will appear in the grating area, so it is necessary to adjust the alignment marks that appear in the grating area. 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 the alignment accuracy. 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 1 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; and corresponds to a schematic diagram of the coupling-in area baffle. Figure 4 It is a schematic diagram of the structure of multiple baffles in a baffle module of a volume holographic optical waveguide exposure device proposed in an embodiment of the present invention, and a schematic diagram of a baffle in a corresponding turning area. Figure 5 1 is a schematic diagram of the structure of multiple baffles in another baffle module of the volume holographic optical waveguide exposure device proposed in an embodiment of the present invention, and corresponds to a schematic diagram of the baffle in the outcoupling area. The gray area is a light-proof area, and the white area is a light-transmitting area.

[0101] First, the coupling region B1 is exposed. The reflector, i.e., the reflective element 607, is controlled to adjust the incident angle of the exposure beam to the coupling region B1, and the workpiece stage 400 is rotated to the rotation angle of the coupling region B1, so that the grating direction is parallel to the xz plane. Among them, the initial angle of the reflector, i.e., the reflective element 607, is 0°, and the initial state is that the mirror surface is parallel to the surface of the bearing platform, and the height of the rotation axis of the reflector is consistent with the height of the center of the light spot. The industrial computer is used to realize the electric control of the rotation angle (90°-Φi) / 2 of the reflector to adjust it to the incident angle Φi of the coupling region; the initial position of the center of the reflector on the y-axis is consistent with the center position of the bearing platform. After the rotation angle (90°-Φi) / 2, the center of the light spot is offset relative to the center of the bearing platform, and the height difference between the center of the bearing platform and the center of the reflector is h. The industrial computer is used to control the electric displacement stage connected to the reflector, and the displacement is h*tanΦi. After the movement, the center of the light spot coincides with the center of the bearing platform on the y-axis. The initial angle of the rotating platform is 0°, and the initial state is that the long side of the waveguide is parallel to the xz plane. The angle rotating stage of the exposure platform is electronically controlled by the industrial computer to rotate the carrier platform to the coupling area rotation angle θi, so that the grating direction of the coupling area is parallel to the xz plane. After moving the center of the coupling area B1 to the center of the spot, open the liquid spray nozzle and drip the refractive index matching liquid 01. Switch to the mask 301 ( Figure 6 (a)), baffle 2011( Figure 2 The baffle 2011 in the middle is removed, the mask 301 is dropped, and the alignment camera 900 is moved to the preset position for alignment. The switch element 602 of the laser beam is turned on for exposure. After the exposure is completed, the workpiece stage 400 is moved to the end of the moving axis stroke to separate the waveguide plate 101 and the mask 301, and the mask 301 is lifted to complete the exposure of the coupling area B1. Each of the above displacement stages, rotating stages, and control switches are connected to the industrial computer and controlled by software. The steps in the above sequence are recorded as exposure program one and written into the industrial computer control software to achieve fully automated exposure. Secondly, the turning area B2 is exposed. The control mirror, i.e., the reflective element 607, is adjusted to the incident angle of the turning area B2, and the workpiece stage 400 is rotated to the rotation angle of the turning area B2 so that the grating direction is parallel to the xz plane. That is, the rotation angle of the electrically controlled reflector is (90°-Φf) / 2 adjusted to the incident angle Φf of the turning area; the industrial computer is used to control the electric displacement stage connected to the reflector, the displacement is h*tanΦf, and the electrically controlled carrier platform is rotated to the turning area rotation angle θf, so that the grating direction of the turning area is parallel to the xz plane. The x-axis and y-axis displacements of the carrier platform are electrically controlled to move the workpiece stage 400, and the center of the first sub-exposure area in the turning area B2 is moved to the center of the light spot. The spray assembly is electrically controlled to open the spray nozzle and drip the refractive index matching liquid 01. The industrial computer is used to control the switch to the mask 301 ( Figure 6 (b)), 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 for electrically controlling the laser beam is turned on for exposure. After the exposure is completed, the switch element 602 is turned off, the displacement of the x-axis and y-axis of the carrier platform is electrically controlled, and the workpiece stage 400 is moved to move the center of the second sub-exposure area in the turning area B2 to the center of the light spot. Replace the baffle 2011 ( Figure 4 (b) in the figure), move the alignment camera 900 to the preset position for alignment. Turn on the switch element 602 of the laser beam for exposure. After the exposure is completed, turn off the switch element 602. The same steps as in the turning area B2, replace the baffle 2011 ( Figure 4 The exposure of each sub-exposure area of ​​the turning area B2 is completed by steps (c)-(d)-(e)-(f)), and then the splicing exposure of the turning area B2 is completed. The steps in the above sequence are recorded as exposure program 2 and written into the industrial computer control software.

[0102] Furthermore, the out-coupling area B3 is exposed. The reflector is controlled to adjust to the incident angle of the out-coupling area B3, and the workpiece stage 400 is rotated to the rotation angle of the out-coupling area B3, so that the grating direction is parallel to the xz plane. The rotation angle of the electrically controlled reflector is (90°-Φo) / 2 and is adjusted to the incident angle Φo of the out-coupling area; the industrial computer is used to control the electric displacement stage connected to the reflector, and the movement displacement is h*tanΦo. The electrically controlled bearing platform is rotated to the rotation angle θo of the out-coupling area, so that the grating direction of the out-coupling area is parallel to the xz plane. The displacement of the x-axis and y-axis of the bearing platform is electrically controlled to move the workpiece stage 400, and the center of the first sub-exposure area in the out-coupling area B3 is moved to the center of the light spot. The liquid spraying assembly is electrically controlled to open the liquid spraying nozzle to drip the refractive index matching liquid 01. The mask plate 301 is electrically controlled to be switched ( Figure 6 (c)), baffle 2011( Figure 5 (g) in the figure), drop the mask 301, and move the alignment camera 900 to the preset position for alignment. Turn on the switch element 602 of the laser beam for exposure. After the exposure is completed, turn off the switch element 602, move the workpiece stage 400, and move the center of the second sub-exposure area of ​​the outcoupling area B3 to the center of the light spot. Replace the baffle 2011 ( Figure 5 (h) in the figure), move the alignment camera 900 to the preset position for alignment. Turn on the switch element 602 of the laser beam for exposure. After the exposure is completed, turn off the switch element 602. The same steps as the decoupling 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. The steps in the above sequence are recorded as exposure program three and written into the industrial computer control software.

[0103] The above-mentioned mirror rotation angle Φ and y-axis displacement, the platform rotation angle θ and x-axis displacement and y-axis displacement, the displacement and switch of the liquid nozzle, the displacement and switch of the mask, the displacement and switch of the alignment camera, and the switch of the spot are all electrically controlled, connected to the industrial computer, and controlled by software. The above steps are written as a program to realize the fully automated exposure operation of the HUD waveguide.

[0104] In summary, according to the volume holographic optical waveguide exposure device and method proposed in the embodiment of the present invention, the device includes: a baffle assembly, a mask assembly, a workpiece stage for carrying the exposed waveguide plate, a light source module, a reflection assembly and a controller arranged in sequence along the transmission direction of the exposure beam; the light source module is used to emit an irradiation beam, and the reflection assembly is used to reflect the irradiation beam to form an exposure beam; the baffle assembly includes at least one baffle module, the baffle module includes at least one baffle, and the baffle includes a light-transmitting area; the mask assembly includes at least one mask, and the mask includes a periodic grating mask structure; the controller is respectively connected to the baffle assembly, The mask assembly, the work stage and the reflection assembly are connected. The controller is used to control the reflection angle of the reflection assembly to the irradiation light beam according to the grating parameters of the area to be exposed of the waveguide plate, so as to adjust the incident angle of the exposure light beam to the area to be exposed. The controller is also used to control the movement of the work stage according to the position of the exposure light beam, so as to adjust the area to be exposed to the center position of the spot of the exposure light beam. The controller is also used to obtain the baffle model and mask model corresponding to the current exposure of the area to be exposed according to the grating parameters, and adjust the baffle position and the mask position according to the position of the exposure light beam to expose the area to be exposed. Therefore, in this technical solution, the entire exposure equipment can be controlled by the controller, and the exposure can be fully automated, which greatly improves the efficiency.

[0105] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0106] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A volume holographic optical waveguide exposure device, characterized in that: include: A baffle assembly, a mask assembly, a workpiece stage for carrying the exposed waveguide sheet, a light source module, a reflection assembly and a controller are sequentially arranged along the transmission direction of the exposure beam; The light source module is used to emit an irradiation beam, and the reflection assembly is used to reflect the irradiation beam to form an exposure beam; the baffle assembly includes at least one baffle module, and the baffle module includes at least one baffle, and the baffle includes a light-transmitting area; the mask assembly includes at least one mask, and the mask includes a periodic grating mask structure; The controller is respectively connected to the baffle assembly, the mask assembly, the workpiece stage and the reflection assembly. The controller is used to control the reflection angle of the reflection assembly to the irradiation light beam according to the grating parameters of the area to be exposed of the waveguide plate, so as to adjust the incident angle of the exposure light beam to the area to be exposed; the controller is also used to control the movement of the workpiece stage according to the position of the exposure light beam, so as to adjust the area to be exposed to the center position of the light spot of the exposure light beam; the controller is also used to obtain the model of the baffle and the model of the mask corresponding to the current exposure of the area to be exposed according to the grating parameters, and adjust the position of the baffle and the position of the mask according to the position of the exposure light beam, so as to expose the area to be exposed.

2. The volume holographic optical waveguide exposure device according to claim 1, characterized in that: The baffle module includes at least one baffle; When there is one baffle, the light-transmitting area of ​​the baffle corresponds to an area to be exposed on the waveguide plate; When there are multiple baffles, the light-transmitting areas in different baffles have different shapes and / or sizes, and 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.

3. The volume holographic optical waveguide exposure device according to claim 2, characterized in that: The waveguide plate includes a coupling-in region and a coupling-out region, or further includes a turning region, and the area to be exposed is any one of the coupling-in region, the coupling-out region or the turning region; each of the baffle modules is arranged corresponding to the area to be exposed; Among them, the area of ​​the coupling-in region is smaller than the area of ​​the turning region or the area of ​​the coupling-out region, and the baffle module corresponding to the coupling-in region includes a baffle; the baffle module corresponding to the turning region or the coupling-out region includes multiple baffles, and the turning region or the coupling-out region is divided into multiple sub-exposure regions before exposure, and the shapes of the light-transmitting areas of the multiple baffles in the corresponding baffle module correspond to the shapes of the sub-exposure regions.

4. The volume holographic optical waveguide exposure device according to claim 1, characterized in that: 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 periods and / or shapes of the periodic grating mask structures on different masks are different.

5. The volume holographic optical waveguide exposure device according to claim 1, characterized in that: Also includes: A switching bracket module, the switching bracket module includes at least one bracket unit, the bracket unit includes a support shaft and a plurality of support rods, one end of the support rod is connected to the support shaft, and the other end is connected to a connecting piece for connecting the baffle and / or the mask, and the support rod can rotate around the support shaft.

6. The volume holographic optical waveguide exposure device according to claim 5, characterized in that: Multiple baffles are located on a first plane, 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.

7. The volume holographic optical waveguide exposure device according to claim 5, characterized in that: The baffle is fixedly arranged with the mask plate, and the baffle is a light shielding layer with a light-transmitting area attached to the mask plate. The support rods are located in the same plane and are connected with the connecting piece of the mask plate.

8. The volume holographic optical waveguide exposure device according to claim 5, characterized in that: 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.

9. The volume holographic optical waveguide exposure device according to claim 5, characterized in that: 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 the number of the baffle modules, and are respectively used to carry the baffles in the corresponding baffle modules.

10. The volume holographic optical waveguide exposure device according to claim 1, characterized in that: The light source module includes a laser, a switch element, a beam shaping element, a first beam expanding element, a polarization element, and a second beam expanding element arranged in sequence along the light transmission direction; The reflective assembly comprises a reflective element and a light blocking element, the outer diameter of the light blocking element is larger than the diameter of the light spot formed by the exposure light beam, and the inner diameter of the light blocking element is smaller than the diameter of the light blocking area of ​​the mask.

11. The volume holographic optical waveguide exposure device according to claim 1, characterized in that: Also includes: A light absorbing element is located at 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.

12. The volume holographic optical waveguide exposure device according to claim 1, characterized in that: Also includes: An alignment camera assembly includes at least one camera to collect the alignment marks on the waveguide plate and align them with the alignment marks on the mask.

13. A method for exposing a volume holographic optical waveguide, characterized in that: Exposure is performed based on the volume holographic optical waveguide exposure device according to any one of claims 1 to 12, and the exposure method comprises the following steps: Acquire the grating parameters of the area to be exposed of the waveguide plate, and control the reflection angle of the reflection component to the irradiation light beam according to the grating parameters of the area to be exposed of the waveguide plate, so as to adjust the incident angle of the exposure light beam to the area to be exposed; Acquiring the position of the exposure beam, and controlling the movement of the workpiece stage according to the position of the exposure beam to adjust the position of the area to be exposed to the exposure beam; The model of the baffle and the model of the mask corresponding to the current exposure of the area to be exposed are obtained according to the grating parameters, and the position of the baffle and the mask are adjusted according to the position of the exposure beam to expose the area to be exposed.

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