TW202326237A - Augmented reality display device - Google Patents

Abstract

An augmented reality display device, which is used to provide an image beam to a user’s eye, includes a display device and an optical combiner. The display device emits the image beam. The optical combiner is used to transmit the image beam to the user’s eye. The optical combiner includes at least one reflection mirror and at least one beam splitting element. The at least one reflection mirror is deposed on the path of the image beam. The at least one beam splitting element is deposed on the path of the image beam from the at least one reflection mirror, and reflect the image beam to the user’s eye. The at least one reflection mirror has refractive power. An external light beam transmit through the at least one beam splitting element to the user’s eye. The at least one reflection mirror does not overlap the at least one beam splitting element in the transmission direction of the external light beam.

Description

Augmented Reality Display Device

The present invention relates to a display device, and in particular to an augmented reality display device.

In recent years, virtual reality (VR) display technology and augmented reality (augmented reality, AR) display technology have flourished, and so far there are various optical systems for head-mounted displays (HMD). Among them, the optical system of many augmented reality display devices adopts the birdbath optical structure. This type of optical architecture can achieve good imaging effects at low cost. The current head-mounted display using the birdbath optical architecture has problems such as bulky size, low image brightness, low external light penetration rate, and vergence-accommodation conflict (VAC).

Vergence adjustment conflict is caused by the difference between the single-eye focal distance (accommodation distance; focal distance) and the binocular focal distance (vergence distance), which causes confusion in the human brain and makes the user prone to dizziness. Both virtual reality display devices and augmented reality display devices have this problem. This is especially true for augmented reality display devices, which use virtual images to interact with real objects. In order to solve the conflict of visual vergence adjustment, a conventional technology uses a small pinhole mirror to reflect the image beam to the human eye, and uses the pinhole imaging technology to achieve the effect of long depth of field, so that the range of the focusing distance of the human eye can be wider, so that the eyesight of both eyes can be improved. The intersecting distance can be consistent with the focusing distance of the human eye, so as to effectively solve the conflict of visual vergence adjustment.

In addition, whether the augmented reality device uses video see-through (vedio see-through, VST) or optical see-through (oedio see-through, OST) will also affect the overall computing power, weight, portability, and image contrast , color, field of view. For example, the image contrast of the video-type see-through device is better, but the calculation amount, power consumption and weight are relatively large, while the calculation amount, power consumption and weight of the optical see-through device are small, but the image quality is easily affected by the external brightness, and There is still room for improvement in size and weight. How to design an optical solution that overcomes bulky size, low image brightness, low external light penetration, and visual vergence adjustment conflicts remains to be resolved.

The invention provides an augmented reality display device, which can enhance the brightness of images viewed by users.

In an embodiment of the present invention, an augmented reality display device provides image light beams to the eyes of a user, and the augmented reality display device includes a display and an optical coupler. The display emits image light beams, and the optical coupler is suitable for delivering the image light beams to the eyes of users. The optical combiner includes at least one mirror and at least one light splitting element. At least one mirror is arranged on the transmission path of the image beam. At least one light splitting element is arranged on the transmission path of the image beam from the mirror, and reflects the image beam to the eyes of the user. At least one mirror has diopter. The light from the outside is transmitted to the eyes of the user through the light splitting element, wherein at least one mirror does not overlap the at least one light splitting element in the transmission direction of the light from the outside.

Based on the above, in the augmented reality display device of the embodiment of the present invention, since the mirror does not overlap the light splitting element in the transmission direction of the light from the outside, the brightness of the image viewed by the user can be improved.

FIG. 1A is a structural diagram of an optical path of an augmented reality display device according to a first embodiment of the present invention. Referring to FIG. 1A , the augmented reality display device 100 provides an image light beam IL to the user's eyes EY, and the augmented reality display device 100 includes a display 102 and an optical coupler 200 . In this embodiment, the display 102 is, for example, a liquid crystal display panel, an organic light-emitting diode (organic light-emitting diode, OLED) display panel, a micro light-emitting diode (micro light-emitting diode, micro-LED) display panel or other appropriate displays. The display 102 emits an image light beam IL, and the optical coupler 200 is adapted to transmit the image light beam IL to the user's eye EY. In this embodiment, the display 102 is disposed above the eyes EY.

The optical combiner 200 includes at least one mirror 210 (a mirror 210 is taken as an example in FIG. 1A ) and at least one beam splitting element 220 (the beam splitting element 220 is an example beam splitter in FIG. 1A ). The mirror 210 is disposed on the transmission path of the image beam IL. The light splitting element 220 is disposed on the transmission path of the image beam IL from the mirror 210, and reflects the image beam IL to the eyes EY of the user. The mirror 210 has a diopter (that is, the diopter of the mirror 210 is not zero). In FIG. 1A , the mirror 210 is a curved mirror as an example. In this embodiment, after the image light beam IL emerges from the display 102, it first passes through the light splitting element 220, and then is reflected back to the light splitting element 220 by the reflector 210, wherein the image light beam IL reflected by the reflector 210 back to the light splitter element 220 is then split. The element 220 is reflected and transmitted to the user's eye EY, and then forms an image on the retina of the user's eye EY, so that the user can see the image displayed on the display 102, which is a magnified virtual image in front of the eye EY.

The light EL from the outside is transmitted through the light splitting element 220 to the user's eyes EY. In this way, the user's eyes EY can not only see the virtual image displayed on the display 102, but also see the external scene, so as to achieve the visual effect of augmented reality. In this embodiment, the light splitting element 220 has a rear side BS for receiving the image beam from the mirror 210, and a front side FS opposite to the back side BS, and the light EL from the outside is transmitted through the light splitting element 220 from the front side FS. The reflective mirror 210 does not overlap the light splitting element 220 in the transmission direction of the light EL from the outside. Therefore, the intensity of the light EL from the outside will not be weakened by the reflector 210, which improves the brightness of the external environment for the user to watch. Because the mirror 210 does not need to allow the light EL from the outside to penetrate, it can increase its reflectivity (for example, close to 100% complete reflection), reduce the loss of the image beam IL in the transmission process, and then improve the user's viewing of the image beam IL The brightness of the virtual image.

Specifically, in this embodiment, the reflection mirror 210 is disposed below the light splitting element 220 . The reflectivity of the mirror 210 is, for example, approximately 100%, and the reflectivity and transmittance of the light splitting element 220 are, for example, approximately 50%. The brightness of the image light beam IL entering the eye EY is about 25% of the brightness emitted by the display 102 , and the brightness of the external light EL entering the eye EY is about 50% of the brightness before entering the light splitting element 220 .

FIG. 1B is a structural diagram of an optical path of an augmented reality display device of a comparative example. Referring to FIG. 1B , the mirror 210' of the augmented reality display device 100' of the comparative example is disposed in front of the light-splitting element 220', and overlaps the light-splitting element 220' in the line-of-sight direction of the eye EY'. The reflectivity of the mirror 210' is, for example, approximately 50%, and the reflectivity and transmittance of the light splitting element 220' are, for example, approximately 50%. The brightness of the image light beam IL' when it enters the eye EY' is about 12.5% of the brightness of the light emitted by the display 102', and the brightness of the light EL' from the outside when it hits the eye EY is about 25% of the brightness before it enters the light splitting element 220'. Compared with the comparative example in FIG. 1B , the overall image brightness of the augmented reality display device 100 in the embodiment of FIG. 1A is increased by about two times.

FIG. 2 is a structural diagram of an optical path of an augmented reality display device according to a second embodiment of the present invention. Referring to FIG. 2 , the difference from the embodiment in FIG. 1A is that in this embodiment, the optical coupler 200 further includes an eyepiece 230 , the light splitting element 220 is disposed inside the eyepiece 230 , and the reflector 210 is disposed on the eyepiece 230 . The eyepiece 230 is, for example, made of a transparent material, such as plastic or glass. In this embodiment, the surface 232 of the eyepiece 230 facing away from the user's eye EY is a plane. In other embodiments, the surface 232 of the eyepiece 230 facing away from the user's eye EY is an arc surface or a free-form surface. In this way, the optical path of the image light beam IL can be extended to place the virtual image at a farther position.

In this embodiment, the augmented reality display device 100 further includes an optical lens 104 disposed on a path of the image light beam IL from the display 102 to the optical coupler 200 . In this embodiment, the optical lens 104 is a convex lens. In other embodiments, the optical lens 104 is a lens formed by a plurality of microstructures.

FIG. 3 is a structural diagram of an optical path of an augmented reality display device according to a third embodiment of the present invention. Please refer to FIG. 3 , the difference from the embodiment in FIG. 2 is that in this embodiment, the display 102 is disposed on the left or right side of the eye EY (the right side is taken as an example in FIG. 3 ). In this embodiment, the optical coupler 200 further includes an eyepiece 230, the light splitting element 220 is disposed inside the eyepiece 230, the reflector 210 is disposed on the eyepiece 230, and the surface 234 of the eyepiece 230 opposite to the reflector 210 is a total reflection There is no reflective film on the surface, and the image light beam IL is totally reflected on the surface 234 and reflected to the light splitting element 220 . In other embodiments, the surface 234 is provided with at least one of a plurality of optical microstructures and reflective film layers. Because the present embodiment adopts a side-type light source, the weight of various mechanisms and circuits of the display 102 can be evenly shared on two sides, thereby increasing the wearing comfort of the user. Compared with the embodiment in FIG. 1A and FIG. 2, the image beam IL has a longer optical path, and the virtual image is at a farther position, which can reduce the power of the image beam IL irradiated on the optical lens 104 and the reflector 210, and increase production feasibility.

FIG. 4 is a structural diagram of an optical path of an augmented reality display device according to a fourth embodiment of the present invention. Referring to FIG. 4 , the difference from the embodiment shown in FIG. 3 is that in this embodiment, the reflector 210 is a reflector formed by a plurality of microstructures, such as a Fresnel reflector. The optical lens 104 is a lens formed by a plurality of microstructures, such as a Fresnel lens, which can reduce the volume and weight of the optical lens 104 . The surface 234 is provided with a plurality of optical microstructures 236 , and the shape of the optical microstructures 236 can be designed according to the reflection angle required for the image beam IL to be transmitted to the mirror 210 , for example, it can be a columnar structure with multiple triangular longitudinal sections. In this embodiment, the mirror formed by the microstructure, the lens formed by the microstructure and the optical microstructure 236 are used to place the virtual image of the image light beam IL at a position one meter away from the user's eye EY.

FIG. 5 is a structural diagram of an optical path of an augmented reality display device according to a fifth embodiment of the present invention. Please refer to FIG. 5 , which is different from the embodiment in FIG. 4 in that in this embodiment, at least one light splitting element 220 is a plurality of micro-reflectors 222 arranged at intervals, and the light EL from the outside can pass through the gap between the micro-mirrors 222 . The image light beam IL can be reflected on the micro-mirror 222 and transmitted to the user's eye EY at intervals, so that the light splitting effect can be achieved. In addition, in this embodiment, the image light beam IL can be totally reflected on the surface of the eyepiece 230 facing the eye EY and the surface facing away from the eye EY, and transmitted to the mirror 210 and the micro-mirror 222 . In this embodiment, the width W of each micromirror 222 is smaller than the diameter of the pupil of the eye EY (for example, less than 2 millimeters), for example, the width of each micromirror 222 in all directions is smaller than the diameter of the pupil ( For example, it is less than 2 millimeters), that is to say, each micro-mirror 222 is, for example, a small pinhole mirror. The small pinhole mirror can elongate the depth of field of the imaging light beam IL and eliminate the conflict of visual vergence adjustment.

FIG. 6A and FIG. 6B are schematic diagrams of the manufacturing process of the light splitting element of the augmented reality display device of FIG. 5 . Please refer to FIG. 6A and FIG. 6B . In this embodiment, during the manufacturing process of the optical coupler 200 , the micro-mirror 222 is conformally disposed on the slope 312 of the columnar structure 310 on the substrate 300 . In detail, an ultra-precision metal mold can be used, a UV molded substrate 300 and a columnar structure 310 can be used, and a material such as a stainless steel mask can be used to expose the area where the micro-mirror 222 will be formed, and the film layer material can be coated on the mask. The exposed area forms the micro-mirror 222, and the columnar structure 310 is filled with UV glue to form the optical coupler 200 shown in FIG. 6B, so that the micro-mirror 222 can be fabricated in the middle of the lens material. In this embodiment, the material of the micro mirror 222 is silver. In this embodiment, the thickness H of the micromirror 222 in the direction perpendicular to the slope 312 is less than 200 nm. Therefore, the light EL from the outside can partially penetrate the micro-mirror 222, and the transmittance is about 30% to 65%, so that the user's line of sight will not be blocked by the micro-mirror 222 when viewing the external environment.

FIG. 7 is a schematic diagram of an augmented reality display device according to a sixth embodiment of the present invention. Please refer to FIG. 7. In this embodiment, the augmented reality display device 100 further includes an electrochromic film 106, which is arranged on the side of the optical coupler 200 facing away from the user's eyes EY, such as in the above-mentioned FIG. 1A The side of the optical coupler 200 of the augmented reality display device 100 in each embodiment shown in FIG. 5 is facing away from the user's eyes EY. In FIG. The side of the optical coupler 200 of the device 100 facing away from the user's eye EY is taken as an example. The user can adjust the discoloration state of the electrochromic sheet 106 according to the usage environment (for example, indoor or outdoor). For example, in indoors, charging places, or other suitable places, the electrochromic sheet 106 can be adjusted to be opaque, so that the light EL from the outside will not enter the user's eyes EY, so as to activate the video mode. See-through: In outdoors, places where charging is not convenient, or other suitable places, the electrochromic sheet 106 can be adjusted to be transparent, so as to activate optical see-through, increasing the flexibility of use. The following content will describe the video see-through system and the optical see-through system in detail.

FIG. 8A is a block diagram of an augmented reality display device in one state (video see-through) according to an embodiment of the present invention, and FIG. 8B is a block diagram of an augmented reality display device in another state (optical perspective) according to an embodiment of the present invention. perspective). Please refer to FIG. 8A and FIG. 8B. In this embodiment, the augmented reality display device 100 may include the display 102, the optical coupler 200 and the configuration of the augmented reality display device 100 of the above-mentioned embodiments in FIGS. 1A to 5. The electrochromic film 106 on the side of the optical coupler 200 facing away from the user's eyes EY is used to be switched to a transparent state or an opaque state, and further includes a video synthesizer 110, a scene generator 120, an eye tracking device 130 and environment sensor 140.

The structure of the video synthesizer 110 , the scene generator 120 , the eye tracker 130 and the environment sensor 140 will be described below using the video see-through system shown in FIG. 8A (the electrochromic film 106 is switched to an opaque state). In this embodiment, the eye tracker 130 is coupled to the scene generator 120 for providing the eyeball position of the user's eye EY to the scene generator 120 . The environment sensor 140 is coupled to the scene generator 120 for providing environment information about the real world to the scene generator 120, wherein the scene generator 120 provides augmented reality image signals according to the eyeball position and the environment information. For example, the environment sensor 140 detects that the scene in front of the user in the real world is a flower, and the eye tracker 130 detects that the line of sight of the user's eyes EY is in the direction of the flower, and the scene is generated. The device 120 can provide augmented reality image signals about butterflies according to the information. The video synthesizer 110 is coupled to the display 102 , the scene generator 120 and the environment sensor 140 . The scene generator 120 provides the augmented reality image signal to the display 102, for example, in this state, the augmented reality image signal is provided to the video synthesizer 110 (such as an augmented reality image signal about a butterfly), and the environment sensor 140 also provides the external environment image signal to the video synthesizer 110 (for example, the external environment image signal about flowers), and the video synthesizer 110 provides a synthesized image signal to the display 102 (for example, about the flower) according to the augmented reality image signal and the external environment image signal. synthetic image signals of flowers and butterflies), users can watch the external environment (such as flowers) and augmented reality images ( such as butterflies).

Next, FIG. 8B is used to illustrate the optical see-through system (the electrochromic film 106 is switched to a transparent state). In this state, the video synthesizer 110 may not communicate with the display 102 , the scene generator 120 and the environment sensor 140 . The scene generator 120 is coupled to the display 102, and directly transmits the generated augmented reality image signal to the display 102, such as ordering the display 102 to provide an image light beam IL related to the butterfly image, and the user can make the electrochromic film 106 transparent. In this case, the augmented reality image (such as a butterfly) can be viewed through the image light beam IL provided by the display 102 , and the external environment (such as a flower) can be viewed directly through the optical coupler 200 to receive the light EL from the outside.

To sum up, in the embodiment of the augmented reality display device of the present invention, since the mirror does not overlap the light splitting element in the transmission direction of the light from the outside, the virtual image viewed by the user and the overall brightness of the external environment are improved. . The weight of the mechanism and the circuit is evenly distributed on both sides by using a side-type light source to increase the comfort of the user. The optical path of the image beam is increased by using the lens formed by the microstructure and the reflector formed by the microstructure, and the virtual image is at a far position, which reduces the power of the image beam irradiated on the optical lens and reflector, and increases the manufacturing feasibility. Use the principle of pinhole imaging to solve the problem of visual vergence adjustment conflicts. The electrochromic film is placed in front of the user's eyes, and the user can choose video-type see-through or optical see-through according to the environment, increasing the flexibility of use.

100, 100': augmented reality display device 110: Video synthesizer 120:Scene Generator 130:Eye tracker 140: Environmental sensor 102, 102': display 104: Optical lens 106:Electrochromic film 200: Optical coupler 210, 210': reflector 220, 220': light splitting element 222: micro mirror 230: Eyepiece 232, 234: surface 236: Optical Microstructure 300: Substrate 310: columnar structure 312: Bevel BS: rear side EL, EL': light from outside EY, EY': user's eyes FS: front side H: Thickness IL, IL': image beam W: width

FIG. 1A is a structural diagram of an optical path of an augmented reality display device according to a first embodiment of the present invention. FIG. 1B is a structural diagram of an optical path of an augmented reality display device of a comparative example. FIG. 2 is a structural diagram of an optical path of an augmented reality display device according to a second embodiment of the present invention. FIG. 3 is a structural diagram of an optical path of an augmented reality display device according to a third embodiment of the present invention. FIG. 4 is a structural diagram of an optical path of an augmented reality display device according to a fourth embodiment of the present invention. FIG. 5 is a structural diagram of an optical path of an augmented reality display device according to a fifth embodiment of the present invention. FIG. 6A and FIG. 6B are schematic diagrams of the manufacturing process of the light splitting element of the augmented reality display device of FIG. 5 . FIG. 7 is a schematic diagram of an augmented reality display device according to a sixth embodiment of the present invention. FIG. 8A is a block diagram of an augmented reality display device in a state (video perspective) according to an embodiment of the present invention. FIG. 8B is a block diagram of an augmented reality display device in another state (optical see-through) according to an embodiment of the present invention.

100: augmented reality display device

102: display

200: Optical coupler

210: reflector

220: light splitting element

BS: rear side

EL: light from outside

EY: user's eyes

FS: front side

IL: image beam

Claims (12)

An augmented reality display device provides an image light beam to an eye of a user, and the augmented reality display device includes: a display emitting the image beam; and an optical coupler adapted to deliver the image beam to the eye of the user, the optical coupler comprising: At least one mirror is arranged on the transmission path of the image beam; and At least one light splitting element is arranged on the transmission path of the image beam from the reflector, and reflects the image beam to the user's eyes, wherein the at least one reflector has a diopter, and a light from the outside is transmitted The light splitting element is transmitted to the user's eyes, and the at least one reflector does not overlap the at least one light splitting element in the transmission direction of the light from the outside. The augmented reality display device as claimed in claim 1, wherein the at least one mirror is a curved mirror. The augmented reality display device as claimed in claim 1, wherein the at least one mirror is a plurality of mirrors formed by structures. The augmented reality display device as described in Claim 1, wherein the optical coupler further includes an eyepiece, the at least one light splitting element is disposed inside the eyepiece, and the at least one reflector is disposed on the eyepiece, and the eyepiece A surface facing away from the eyes of the user is a plane, arc or free-form surface. The augmented reality display device as claimed in claim 1, wherein the at least one light-splitting element is a light-splitting mirror or a plurality of micro-mirrors arranged at intervals. The augmented reality display device as claimed in claim 5, wherein the at least one light-splitting element is the micro-mirrors arranged at intervals, and the material of the micro-mirrors is silver. The augmented reality display device as claimed in claim 5, wherein the at least one light-splitting element is the micro-mirrors arranged at intervals, and the thickness of the micro-mirrors in a direction perpendicular to the slopes is less than 200 nanometers. The augmented reality display device as described in Claim 1, further comprising an optical lens disposed on the path of the image beam from the display to the optical coupler, the optical lens is formed by a convex lens or a plurality of microstructures lens. The augmented reality display device as described in Claim 1, wherein the optical coupler further includes an eyepiece, the at least one light splitting element is disposed inside the eyepiece, the at least one reflector is disposed on the eyepiece, and the eyepiece is in A surface opposite to the at least one mirror is a total reflection surface, or at least one of a plurality of optical microstructures and a reflection film layer is provided. The augmented reality display device as claimed in claim 1 further includes an electrochromic film disposed on a side of the optical coupler facing away from the user's eyes. The augmented reality display device as described in claim 10, further comprising: An electrochromic film is arranged on the side of the optical coupler facing away from the eye of the user; A scene generator, coupled to the display, for providing an augmented reality image signal to the display; an eye tracker, coupled to the scene generator, to provide the eyeball position of the user's eyes to the scene generator; and An environment sensor, coupled to the scene generator, is used to provide an environment information about the real world to the scene generator, wherein the scene generator provides the augmented reality image signal according to the eyeball position and the environment information . The augmented reality display device as described in claim 11, further comprising a video synthesizer coupled to the display, the scene generator and the environment sensor, wherein the electrochromic film is used to be switched to a transparent state or an opaque state, when the electrochromic film is switched to the transparent state, the scene generator provides the augmented reality image signal to the display; when the electrochromic film is switched to the opaque state, the scene generator provides the augmented reality image signal to the video synthesizer, the environment sensor provides an external environment image signal to the video synthesizer, and the video synthesizer responds to the augmented reality image signal and the external environment image signal, providing a synthesized image signal to the display.

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