Augmented reality display devices

Abstract

The present invention provides an augmented reality display device for providing augmented reality images to a user's eyes. The augmented reality display device includes a display module and multiple lens assemblies. The display module includes a projector and multiple switching elements. The projector provides an original image beam. Multiple switching elements are sequentially arranged in the path of the original image beam. Each switching element reflects or transmits the original image beam. The reflection paths of each ray of the original image beam on the switch elements intersect at a point, forming multiple image beams. Multiple lens assemblies are arranged in the paths of the multiple image beams. The multiple image beams are reflected at different angles by the lens assemblies, and the lens assemblies reflect the multiple image beams toward the eyes.

Description

Technical Field

[0001] The present invention relates to a display device, and in particular to an augmented reality display device. Background Art

[0002] In virtual reality (VR) or augmented reality (AR) display technology, different images with different viewing angles (disparity) can be projected onto the user's left and right eyes, allowing the left and right eyes to focus on different planes, thus creating stereoscopic vision. However, current research indicates that while this technology can create a sense of stereoscopic vision, the left and right eyes still focus on different planes at the same depth. This visual effect differs from the way the human eye focuses on different depths of three-dimensional objects in real space. This discrepancy is one of the causes of dizziness in some users, an effect known as vergence-accommodation conflict (VAC).

[0003] In order to resolve the conflict between visual convergence and accommodation, an existing technology uses a pinhole mirror to reflect the image beam to the human eye, and uses pinhole imaging technology to achieve a long depth of field effect, so that the focus distance of the human eye can be wider, and the distance where the lines of sight of both eyes intersect can be consistent with the focus distance of the human eye, so as to effectively resolve the conflict between visual convergence and accommodation. In the main optical architecture of the existing technology, image beams covering different vertical fields of view (FoV) are emitted from different positions of the panel, pass through the optical lens, and are incident on multiple pinhole mirrors. To make the optical lens thinner and lighter, it is necessary to reduce the diameter of the optical lens, but this will require reducing the vertical field of view of the image. Summary of the Invention

[0004] The present invention is directed to an augmented reality display device, which can achieve lightweight and thin lenses.

[0005] According to one embodiment of the present invention, an augmented reality display device is provided for providing augmented reality images to a user's eyes. The augmented reality display device includes a display module and multiple lens assemblies. The display module includes a projector and multiple switching elements. The projector provides an original image beam. Multiple switching elements are sequentially arranged along the path of the original image beam. Each switching element reflects or transmits the original image beam. The reflection paths of each ray of the original image beam on the switch elements intersect at a point, forming multiple image beams. Multiple lens assemblies are arranged along the paths of the multiple image beams. The multiple image beams reflect at different angles on the lens assemblies, and the lens assemblies reflect the multiple image beams toward the eyes.

[0006] Based on the above, in the augmented reality display device provided by the embodiment of the present invention, since the reflection paths of the original image light beams on the switch element intersect at one point, forming multiple groups of image light beams, and the reflection angles of the image light beams on the lens group are different, the light beams composed of the image light beams can be narrowed, thereby achieving the goal of making the lens lighter and thinner. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 is a schematic diagram of an augmented reality display device according to an embodiment of the present invention;

[0008] Figure 2 for Figure 1 A schematic diagram of a display module of an augmented reality display device;

[0009] Figure 3 for Figure 1 A schematic diagram of an augmented reality display device forming a virtual image in front of a user's eyes;

[0010] Figure 4 for Figure 2 A schematic diagram of a projector of a display module;

[0011] Figure 5A for Figure 2 A cross-sectional schematic diagram of a switch element of a display module;

[0012] Figure 5B for Figure 5A A cross-sectional diagram of a liquid crystal phase modulator with a switching element having a voltage turned on and off;

[0013] Figure 6 for Figure 1 A schematic diagram of output states of an image beam of an augmented reality display device at different times;

[0014] Figure 7A for Figure 1 A schematic diagram of another embodiment of the output state of an image light beam of an augmented reality display device at different times;

[0015] Figure 7B for Figure 7A A schematic diagram of the reflection position of the image light beam on the switching element at different times according to an embodiment of the present invention;

[0016] Figure 8 FIG. 4 is a schematic diagram of an augmented reality display device according to another embodiment of the present invention. DETAILED DESCRIPTION

[0017] Reference will now be made in detail to exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Whenever possible, the same reference numerals are used in the drawings and the description to refer to the same or like parts.

[0018] Figure 1 is a schematic diagram of an augmented reality display device according to an embodiment of the present invention, Figure 2 for Figure 1 A schematic diagram of a display module of an augmented reality display device, Figure 3 for Figure 1 Schematic diagram of an augmented reality display device forming a virtual image in front of the user's eyes. Figures 1 to 3 The augmented reality display device 100 includes a display module 200 and multiple lens assemblies 300. The display module 200 includes a projector 230 and multiple switch elements 220. The projector 230 provides an original image beam LB. Multiple switch elements 220 (e.g., switch elements 220a, 220b, and 220c) are sequentially arranged along the path of the original image beam LB. Each switch element 220 reflects or transmits the original image beam LB. The reflection paths of each ray of the original image beam LB on the switch elements 220 intersect at a point, forming multiple image beams (e.g., T1, T2, and T3). Multiple lens assemblies 300 are arranged along the paths of the multiple image beams T1, T2, and T3. The multiple image beams T1, T2, and T3 are reflected at different angles by the lens assemblies 300, and the lens assemblies 300 reflect the multiple image beams T1, T2, and T3 toward the eye EY.

[0019] Specifically, in this embodiment, the display module 200 further includes a projection panel 210. The paths of multiple light rays of the original image beam LB reflected from the switch element 200 intersect at multiple points on the projection panel 210, forming a plurality of pixels 212. Each pixel 212 provides multiple image beams T1, T2, and T3 with different emission angles. In this embodiment, the projection panel 210 is a diffuser or a microlens array. The optical lens 110 is disposed in the path of the multiple image beams T1, T2, and T3 to receive the multiple image beams T1, T2, and T3. Multiple lens assemblies 300 are disposed in the path of the image beams T1, T2, and T3 from the optical lens 110. Each lens assembly 300 reflects one of the image beams T1, T2, and T3 toward the eye EY. The paths of the original image beam LB reflected from the corresponding positions of the switch elements 220a, 220b, and 220c intersect at a single point (i.e., a single pixel 212) on the projection panel 210. The original image beam LB reflected by the switching element 220 forms an image beam after transmitting through the projection plate 210. For example, in this embodiment, the light reflected by the switching elements 220a, 220b, and 220c forms three sets of image beams T1, T2, and T3 behind the projection plate 210, respectively. However, the present invention is not limited to three switching elements 220, nor is it limited to three sets of image beams. Because each pixel 212 of the projection plate 210 provides an image beam T1, T2, and T3 with a different light output angle, the image beams T1, T2, and T3 emitted from each pixel 212 partially overlap on the optical path to the optical lens 110. This allows the beam formed by the image beams T1, T2, and T3 to be narrowed, thereby requiring only a smaller diameter optical lens 110.

[0020] In this embodiment, each lens assembly 300 includes a micro-mirror 310, and the micro-mirrors 310 are arranged at different angles. Alternatively, in another embodiment, each lens assembly 300 includes a micro-mirror 310 and a reflector 320. A group of image beams (e.g., one of the image beams T1, T2, T3) from each switch element 220 (e.g., one of the switch elements 220a, 220b, 220c) is sequentially reflected by the reflector 320 and the micro-mirror 310 and transmitted to the user's eye EY. The reflectors 320 are arranged at different angles, while the micro-mirrors 310 are arranged at the same angle. The micro-mirrors 310 are, for example, pinhole mirrors.

[0021] The augmented reality display device 100 is used to provide an augmented reality image IMG to the user's eyes EY, such as Figure 3 For example, please also refer to Figure 1 and Figure 3In this embodiment, the plurality of mirror groups 300 are three mirror groups 300a, 300b and 300c, and the mirror groups 300a, 300b and 300c include micro-mirrors 310a, 310b and 310c respectively. In this embodiment, there may be a plurality of micro-mirrors 310a, a plurality of micro-mirrors 310b and a plurality of micro-mirrors 310c. These micro-mirrors 310a, 310b and 310c are arranged in a Figure 1 The micro-mirrors 310a, 310b, and 310c are arranged in a direction perpendicular to the paper. The micro-mirrors 310a, 310b, and 310c reflect the image light beams T1, T2, and T3 respectively to the user's eye EY, and form an augmented reality image IMG in front of the user's eye EY. In other words, the augmented reality image IMG is composed of the virtual images of the image light beams T1, T2, and T3. In this embodiment, the lens groups 300a, 300b, and 300c are arranged from top to bottom relative to the user (for example, Figure 1 Because the micro-reflectors 310a, 310b, and 310c are arranged from top to bottom (with different angles), the virtual images of the image beams T1, T2, and T3 are arranged from top to bottom. In other words, the virtual images of the image beams T1, T2, and T3 cover different vertical viewing angles as seen by the user. However, in other embodiments, the lens assemblies 300a, 300b, and 300c can also be arranged from left to right relative to the user (for example, the micro-reflectors 310a, 310b, and 310c are arranged from left to right). In this way, the virtual images of the image beams T1, T2, and T3 are arranged from left to right, covering different horizontal viewing angles as seen by the user. Although this embodiment uses three lens assemblies 300a, 300b, and 300c and the corresponding three image beams T1, T2, and T3 as an example, the present invention is not limited to this. In some other embodiments, the lens assembly 300 is arranged from left to right and from top to bottom relative to the user (for example, the micro-reflectors 310 with different angles are arranged from left to right and from top to bottom). Therefore, the virtual images of the multiple image beams are arranged from left to right and from top to bottom, that is, they cover different field of view angles in the horizontal and vertical directions as seen by the user.

[0022] In this embodiment, the acute angles between the switch elements 220 and the original image beam LB increase sequentially along the path of the original image beam LB. Specifically, switch elements 220c, 220b, and 220a are the first, second, and third switch elements 220, respectively, along the path of the original image beam LB. Of the three switch elements, switch element 220c has the smallest angle with the original image beam LB, and the original image beam LB has the largest angles of incidence and reflection on switch element 220c. Switch element 220a has the largest angle with the original image beam LB, and the original image beam LB has the smallest angles of incidence and reflection on switch element 220a. Switch element 220b has an angle between the original image beam LB and switch elements 220a and 220c, respectively, and the original image beam LB has an angle of incidence and reflection on switch element 220b that is between the angles of incidence and reflection on switch element 220b and switch elements 220a and 220c, respectively. However, in other embodiments, the acute angle between the switching element 220 and the original image beam LB may also decrease sequentially along the path of the original image beam LB, or be set in other appropriate manners so that the reflected paths of the original image beam LB after being incident on different switching elements 220 intersect at a point (i.e., pixel 212) on the projected panel 210.

[0023] Figure 4 for Figure 2 Schematic diagram of the projector of the display module. Figure 4 In this embodiment, the projector 230 includes a laser scanning projector 232, a collimating lens 234, and a linear polarizer 236. The original image beam LB is emitted by the laser scanning projector 232 and sequentially passes through the collimating lens 234 and the linear polarizer 236. Therefore, the original image beam LB emitted by the projector 230 is a collimated linearly polarized light.

[0024] Figure 5A for Figure 2 A cross-sectional schematic diagram of a switching element of a display module, Figure 5B for Figure 5A Cross-sectional diagram of the liquid crystal phase modulator voltage on and off of the switching element. Figure 5A and Figure 5B, the switch element 220 includes a liquid crystal phase modulator 222 and a polarization reflector 224. The liquid crystal phase modulator 222 and the polarization reflector 224 of each switch element 220 are arranged in sequence on the optical path of the original image light beam LB. The liquid crystal phase modulator 222 includes two transparent electrodes ITO, a liquid crystal layer LC and a controller CRL. The liquid crystal layer LC is arranged between the two transparent electrodes ITO, and the controller CRL is coupled to the two transparent electrodes ITO. The original image light beam LB from the projector 230 has a first polarization direction d1 (the first polarization direction d1 is a p-polarization direction). When the original image light beam LB passes through the liquid crystal phase modulator 222, if the voltage of the controller CRL is turned on (such as Figure 5B The original image light beam LB having the first polarization direction d1 (ie, the p-polarization direction) will not be polarized after passing through the liquid crystal layer LC, and will then transmit the polarization reflector 224 (eg, Figure 5A The light shown above transmits the polarized reflector 224); if the voltage of the controller CRL is turned off (such as Figure 5B The liquid crystal phase modulator 222 on the right side) is used as the original image light beam LB with the first polarization direction d1 (i.e., the p-polarization direction) after passing through the liquid crystal layer LC. The original image light beam LB will be transformed into the second polarization direction d2 (the second polarization direction d2 is the direction of entering and exiting the paper, i.e., the s-polarization direction) after passing through the liquid crystal layer LC. Therefore, it will be reflected on the polarization reflector 224 (e.g., Figure 5A The lower beam of light shown is reflected by polarizing reflector 224. In this manner, controller CRL can be used to control switch element 220 to reflect or transmit original image beam LB. In other embodiments, depending on the liquid crystal mode, when the voltage of controller CRL is off, original image beam LB having a first polarization direction d1 may be converted to a second polarization direction d2 after passing through liquid crystal layer LC. When controller CRL is on, original image beam LB may not be polarized after passing through liquid crystal layer LC.

[0025] For example, in this embodiment, if the voltages of the controllers CRL of switch elements 220c and 220b are both on, the original image beam LB passes through switch elements 220c and 220b, is incident on switch element 220a, and is reflected, generating image beam T1 behind the projection panel 210. If the voltages of the controllers CRL of switch elements 220c and 220b are on and off, respectively, the original image beam LB passes through switch element 220c, is reflected by switch element 220b, and generates image beam T2 behind the projection panel 210. If the voltage of the controller CRL of switch element 220c is off, the original image beam LB is reflected by switch element 220c, generating image beam T3 behind the projection panel 210. In this embodiment, switch element 220a can be replaced with a conventional reflector. Because a single projector 230 is used to generate an image of a portion of the field of view of the augmented reality image IMG, the resulting image resolution is higher than when a single projector is used to generate the entire augmented reality image. In this embodiment, the resolution is three times higher.

[0026] Figure 6 for Figure 1 Schematic diagram of the output state of the image beam of the augmented reality display device at different times. In this embodiment, the switch elements 220a, 220b, and 220c reflect the original image beam LB in turn, and at each moment there is a switch element 220 that reflects the original image beam LB to form a group of image beams. For example, please refer to Figure 6 , with 0 and 1 used in the figure to represent no output and output. At time Ta, switching element 220c reflects the original image beam LB, forming image beam T3 behind the projected panel 210. At time Tb, switching element 220b reflects the original image beam LB, forming image beam T2 behind the projected panel 210. At time Tc, switching element 220a reflects the original image beam LB, forming image beam T1 behind the projected panel 210. Therefore, image beams T1, T2, and T3 are generated in turn behind the projected panel 210 and illuminate the user's eye EY in turn. If the controller CRL of switching element 220 switches quickly enough, the user will experience a sense of persistence of vision for the virtual images of image beams T1, T2, and T3, and the user will appear to see the complete augmented reality image IMG.

[0027] Figure 7A for Figure 1 A schematic diagram of another embodiment of the output states of an image light beam of an augmented reality display device at different times. Figure 7B for Figure 7ASchematic diagram of the reflection position of the image beam on the switch element 220 at different times in the embodiment of the present invention. In this embodiment, the switch element 220 includes a plurality of pixels PXL. The pixels PXL of each switch element 220 reflect the original image beam LB in turn. At each moment, a plurality of the switch elements 220 reflect a portion of the original image beam LB, forming a portion of the plurality of groups of image beams. The pixels PXL include, for example, thin film transistors. Figure 7A and Figure 7B ,in Figure 7A The vertical axis represents the output of the pixel PXL at the corresponding position of each switching element 200 (for example, the output of the pixel PXL in the 3rd, 6th, 9th, ... rows). Figure 7B The top column shows the reflection states of the switch elements 220c, 220b, and 220a at time Ta from left to right, the middle column shows the reflection states of the switch elements 220c, 220b, and 220a at time Tb from left to right, and the bottom column shows the reflection states of the switch elements 220c, 220b, and 220a at time Tc from left to right.

[0028] For example, in this embodiment, at time Ta, the pixels PXL in the 3rd, 6th, 9th, ... rows of switching element 220c reflect the original image beam LB, forming a portion of image beam T3. The portion of the original image beam LB not reflected by switching element 220c passes through the remaining pixels PXL of switching element 220c and enters switching element 220b. The pixels PXL in the 1st, 4th, 7th, ... rows of switching element 220b reflect the original image beam LB, forming a portion of image beam T2. The portion of the original image beam LB not reflected by switching element 220b passes through the remaining pixels PXL of switching element 220b and enters switching element 220a (which may also be replaced by a conventional reflector) and is reflected, forming a portion of image beam T1. At time Tb, pixels PXL in the 2nd, 5th, 8th, ... rows of switching element 220c reflect the original image beam LB, forming another portion of image beam T3. The portion of original image beam LB not reflected by switching element 220c passes through the remaining pixels PXL of switching element 220c and enters switching element 220b. Pixels PXL in the 3rd, 6th, 9th, ... rows of switching element 220b reflect the original image beam LB, forming another portion of image beam T2. The portion of original image beam LB not reflected by switching element 220b passes through the remaining pixels PXL of switching element 220b, enters switching element 220a, and is reflected to form another portion of image beam T1. At time Tc, pixels PXL in the 1st, 4th, 7th, ... rows of switching element 220c reflect the original image beam LB, forming another portion of image beam T3. The portion of original image beam LB not reflected by switching element 220c passes through the remaining pixels PXL of switching element 220c and enters switching element 220b. The pixels PXL in the 2nd, 5th, 8th, etc. rows of switching element 220b reflect the original image beam LB, forming another portion of the image beam T2. The portion of the original image beam LB not reflected by switching element 220b passes through the remaining pixels PXL of switching element 220b, enters switching element 220a, and is reflected there, forming another portion of the image beam T1. Therefore, the image beams T1, T2, and T3 simultaneously illuminate the user's eye EY, with different portions of the image beams T1, T2, and T3 illuminating the user's eye EY in turn. If the controller CRL of switching element 220 switches quickly enough, the user will experience a sense of persistence of vision for the virtual images of the different portions of the image beams T1, T2, and T3, seemingly viewing the complete augmented reality image IMG. The advantage of alternating portions of the image beams T1, T2, and T3 illuminating the user's eye EY is that it achieves a better persistence of vision and reduces flickering in the augmented reality image IMG.

[0029] Figure 8 FIG is a schematic diagram of an augmented reality display device according to another embodiment of the present invention. Figure 1The difference between augmented reality display devices is that Figure 8 Each mirror group 300 of the augmented reality display device 100 includes a micro-mirror 310 and a reflector 320. A group of image light beams (e.g., one of the image light beams T1, T2, T3) from each switch element 220 is sequentially reflected by the reflector 320 (e.g., one of the reflectors 320a, 320b, 320c) and the micro-mirror 310 (e.g., one of the micro-mirrors 310a, 310b, 310c) and transmitted to the user's eye EY. The reflectors 320 are set at different angles, while the micro-mirrors 310 are set at the same angle. Figure 8 In this embodiment, the mirror assembly 300 is positioned within the light guide plate. The reflector 320 can be a coating on the inner surface of the light guide plate, or the image beam can be totally reflected directly from the inner surface of the light guide plate. Therefore, the reflector 320 can be the inner surface of the light guide plate. The advantage of using the reflector 320 is that the micro-mirrors 310 can be set at the same angle, which reduces manufacturing difficulty and increases mass production.

[0030] In summary, in the augmented reality display device provided by the embodiments of the present invention, the reflection paths of the original image beams on the switch element intersect at a point, forming multiple image beams. Furthermore, the image beams are reflected at different angles on the lens assembly. This allows the resulting beams to be narrowed, resulting in thinner and lighter lenses. Furthermore, because time-sharing multitasking is used to project images covering different fields of view, the device exhibits superior resolution.

[0031] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An augmented reality display device, characterized in that: For providing an augmented reality image to a user's eyes, the augmented reality display device comprises: Display module, including: a projector, providing the original image beam; and a plurality of switch elements, the plurality of switch elements being sequentially arranged on the path of the original image beam, the switch element having a reflecting and transmitting function being located between the switch element having a reflecting function and the projector, the switch element having a reflecting and transmitting function reflecting and transmitting the original image beam, the switch element having a reflecting function reflecting the original image beam, the reflection paths of each light ray of the original image beam on the plurality of switch elements intersecting at a point, forming a plurality of groups of image beams; and A plurality of mirror groups are arranged on the paths of the plurality of image light beams. The plurality of image light beams have different reflection angles on the plurality of mirror groups, and the plurality of mirror groups reflect the plurality of image light beams toward the eyes.

2. The augmented reality display device according to claim 1, wherein Each mirror group includes a micro-reflector, and the micro-reflectors are arranged at different angles.

3. The augmented reality display device according to claim 1, wherein: Each mirror set includes a micro-reflector and a reflector. A group of image light beams from each switch element are sequentially reflected by the reflector and the micro-reflector and transmitted to the user's eyes. The multiple reflectors are set at different angles, while the multiple micro-reflectors are set at the same angle.

4. The augmented reality display device according to claim 1, wherein It also includes an optical lens, which is arranged on the path of the multiple groups of image light beams and is used to receive the multiple groups of image light beams.

5. The augmented reality display device according to claim 1, wherein: The display module also includes a projected plate, and the reflection paths of multiple light rays of the original image beam on the multiple switching elements intersect at multiple points on the projected plate to form multiple pixels. Each pixel provides multiple groups of image beams with different light output angles. The projected plate is a diffuser or a microlens array.

6. The augmented reality display device according to claim 1, wherein: The plurality of lens groups are arranged inside the light guide plate.

7. The augmented reality display device according to claim 1, wherein: The acute angles between the plurality of switch elements and the original image light beam increase sequentially along the path of the original image light beam.

8. The augmented reality display device according to claim 1, wherein: The acute angles between the plurality of switch elements and the original image light beam decrease in sequence along the path of the original image light beam.

9. The augmented reality display device according to claim 1, wherein: The projector includes a laser scanning projector, a collimating lens and a linear polarizing plate. The original image light beam is emitted from the laser scanning projector and passes through the collimating lens and the linear polarizing plate in sequence.

10. The augmented reality display device according to claim 1, wherein: At least some of the multiple switching elements include a liquid crystal phase modulator and a polarization reflector. The liquid crystal phase modulator and the polarization reflector of each switching element are arranged in sequence on the optical path of the original image light beam. The liquid crystal phase modulator includes two transparent electrodes, a liquid crystal layer and a controller. The liquid crystal layer is arranged between the two transparent electrodes, and the controller is coupled to the two transparent electrodes.

11. The augmented reality display device according to claim 1, wherein: The plurality of switch elements reflect the original image light beam in turn, and at each moment there is one switch element reflecting the original image light beam to form a group of image light beams.

12. The augmented reality display device according to claim 1, wherein: The multiple switching elements include multiple pixels, and the multiple pixels of each switching element reflect the original image light beam in turn. At each moment, multiple of the multiple switching elements reflect a portion of the original image light beam to form a portion of the multiple groups of image light beams.

13. The augmented reality display device according to claim 1, wherein: The plurality of lens groups are arranged from top to bottom or from left to right, wherein top, bottom, left and right are relative to the user.

14. The augmented reality display device according to claim 1, wherein: The plurality of lens groups are arranged from left to right and from top to bottom, wherein top, bottom, left and right are relative to the user.

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