CN118151382A

CN118151382A - Augmented reality display device

Info

Publication number: CN118151382A
Application number: CN202211566138.9A
Authority: CN
Inventors: 邱奕荣; 涂宗伟; 石维国
Original assignee: Acer Inc
Current assignee: Acer Inc
Priority date: 2022-12-07
Filing date: 2022-12-07
Publication date: 2024-06-07

Abstract

The invention provides an augmented reality display device for wearing in front of eyes of a user. The augmented reality display device includes an image source, a polarizing plate, a first wave plate, a transflective element, a first lens, a second wave plate, a polarizing reflective plate, a second lens, a light guiding unit, and a curved transflective film. The image source is used for emitting an image light beam, and the polaroid, the first wave plate, the transflective element, the first lens, the second wave plate, the polarized reflector and the second lens are sequentially arranged on the path of the image light beam. The light guide unit has a reflecting surface. The curved transflective film is disposed on the light guiding unit. After the image light beam enters the light guide unit, the image light beam is reflected to eyes of a user by the reflecting surface and the curved transparent reflecting film in sequence.

Description

Augmented reality display device

Technical Field

The present invention relates to a display device, and more particularly to an augmented reality display device (augmented REALITY DISPLAY DEVICE).

Background

In recent years, virtual Reality (VR) display technology and augmented reality (augmented reality, AR) display technology have been vigorously developed, and various optical systems for head-mounted displays (HMDs) have been used. The existing head-mounted display has the problems of huge volume, visual convergence adjustment conflict (vergence-accommodation conflict, VAC) and the like.

The convergence adjustment conflict is caused by confusion of human brain due to the fact that the single eye focusing distance (accommodation distance) is different from the double eye focusing distance (VERGENCE DISTANCE), and the user can easily feel dizziness. This problem is present in both virtual reality display devices and augmented reality display devices. This problem is particularly evident with augmented reality display devices because virtual images are used to interact with real objects. Therefore, how to design an optical solution that can overcome the convergence adjustment conflict and reduce the volume of the head-mounted display remains a problem to be solved.

Disclosure of Invention

The present invention is directed to an augmented reality display device that can achieve good optical effects with a small volume.

An embodiment of the present invention provides an augmented reality display device for wearing in front of eyes of a user. The augmented reality display device includes an image source, a polarizing plate (polarizer), a first wave plate, a transflective element (TRANSFLECTIVE ELEMENT), a first lens, a second wave plate, a polarizing reflective plate (REFLECTIVE POLARIZER), a second lens, a light guiding unit, and a curved transflective film (curved TRANSFLECTIVE FILM). The image source is used for emitting an image light beam, and the polaroid is arranged on the path of the image light beam. The first wave plate is disposed on the path of the image beam from the polarizer, and the transflective element is disposed on the path of the image beam from the first wave plate. The first lens is disposed on the path of the image beam from the transflective element, and the second wave plate is disposed on the path of the image beam from the first lens. The polarizing reflector is disposed on the path of the image beam from the second wave plate, and the second lens is disposed on the path of the image beam from the polarizing reflector. The light guide unit is configured on the path of the image light beam from the second lens, wherein the light guide unit is provided with a reflecting surface. The curved transflective film is disposed on the light guiding unit, wherein the image light beam is reflected by the reflective surface and the curved transflective film to the eyes of the user after entering the light guiding unit, and the light from the external object is transmitted to the eyes of the user through the curved transflective film.

In the augmented reality display device according to the embodiment of the invention, since the architecture of the polarizer, the first wave plate, the transflective element, the first lens, the second wave plate and the polarizing reflector is adopted, the image beam can be folded back twice between the transflective element and the polarizing reflector, and the optical path is further increased without enlarging the space occupied by the element. Therefore, the augmented reality display device of the embodiment of the present invention can achieve a good optical effect using a small space.

Drawings

FIG. 1 is a schematic diagram of an augmented reality display device according to an embodiment of the present invention;

FIG. 2 is a graph of the separation of the first lens and the second lens of FIG. 1 relative to the focal length adjustment of an augmented reality display device;

fig. 3 is a schematic structural view of an augmented reality display device according to another embodiment of the present invention.

Detailed Description

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

Fig. 1 is a schematic diagram of an augmented reality display device according to an embodiment of the present invention. Referring to fig. 1, the augmented reality display device 200 of the present embodiment is intended to be worn in front of the eyes 60 of a user. The augmented reality display device 200 includes an image source 110, a polarizing plate 120, a first wave plate 130, a transflective element 140, a first lens 150, a second wave plate 160, a polarizing reflecting plate 170, a second lens 180, a light guiding unit 210, and a curved transflective film 220. The image source 110 is configured to emit an image beam 112. In this embodiment, the image source 110 is a display panel. For example, the image source 110 is an organic light-emitting diode (OLED) display, a Liquid Crystal On Silicon (LCOS) panel, a digital micro-mirror device (DMD), or other devices that can provide the image beam 112.

The polarizer 120 is disposed on the path of the image beam 112. The first wave plate 130 is disposed on the path of the image beam 112 from the polarizing plate 120, and the transflective element 140 is disposed on the path of the image beam 112 from the first wave plate 130. The first lens 150 is disposed on the path of the image beam 112 from the transflective element 140, and the second wave plate 160 is disposed on the path of the image beam 112 from the first lens 150. The polarizing reflector 170 is disposed on the path of the image beam 112 from the second wave plate 160, and the second lens 180 is disposed on the path of the image beam 112 from the polarizing reflector 170.

In the present embodiment, the polarizing plate 120 is, for example, a linear polarizing plate, and the transflective element 140 is a transflective film and is disposed on a surface of the first lens 150 facing the first wave plate 130. In one embodiment, the transflective film is, for example, a transflective film.

In the present embodiment, the first wave plate 130 and the second wave plate 160 are quarter wave plates. In this embodiment, the image beam 112 has a first linear polarization direction after passing through the polarizer 120, and a circular polarization direction after passing through the first waveplate 130 (i.e., the quarter waveplate). Then, a portion of the image beam 112 passes through the transflective element 140 and the first lens 150, and has a second linear polarization direction after passing through the second wave plate 160. The polarizing reflector 170 (i.e., reflective polarizer) is adapted to reflect light having the second linear polarization direction and to transmit light having the first linear polarization direction, such that the polarizing reflector 170 reflects the image light beam 112 having the second linear polarization direction from the second wave plate 160. Then, the image beam 112 having the second linear polarization direction has a circular polarization direction after passing through the second wave plate 160. The image beam 112 is then reflected by the transflector 140 after passing through the first lens 150 and is again passed to the second waveplate 160 after passing through the first lens 150. The image beam 112 having the circular polarization direction has the first linear polarization direction after passing through the second wave plate 160, and thus the image beam 112 having the first linear polarization direction is then transmitted through the polarizing reflector 170 to the second lens 180. In this embodiment, the first linear polarization direction is perpendicular to the second linear polarization direction. The image source 110, the polarizer 120, the first wave plate 130, the transflector 140, the first lens 150, the second wave plate 160, the polarizing reflector 170, and the second lens 180 may form the projection module 100. The structure shown in the large box of the left projection module 100 of fig. 1 is an enlarged view of the small box of the right projection module 100 of fig. 1, showing in detail the detailed elements of the projection module 100.

The light guiding unit 210 is disposed on the path of the image beam 112 from the second lens 180, wherein the light guiding unit 210 has a reflecting surface 212. The curved transflective film 220 is disposed on the light guiding unit 210, wherein the image beam 112 is reflected by the reflective surface 212 and the curved transflective film 220 to the user's eye 60 after entering the light guiding unit 210, so that the user's eye 60 can see the virtual image in front of the light guiding unit 210. On the other hand, the light 50 from the external object partially penetrates the curved transreflective film 220 to be transmitted to the user's eye 60. In this way, the user's eyes 60 can simultaneously see the virtual image and the external object provided by the augmented reality display device 200, thereby achieving the effect of augmented reality.

In the present embodiment, the light guiding unit 210 is a light guiding column, and the curved transflective film 220 is sandwiched in the light guiding column. For example, the light guiding unit 210 includes a first light transmitting portion 214 and a second light transmitting portion 216, and the curved transflective film 220 is sandwiched between the first light transmitting portion 214 and the second light transmitting portion 216. In this embodiment, the concave surface of the curved transflector 220 faces the eye 60. In one embodiment, the curved transflective film 220 is a transflective film. In the present embodiment, the reflection surface 212 may be a total reflection surface, or a reflection film may be provided on the reflection surface 212 to reflect the image beam 112.

In the augmented reality display device 200 of the present embodiment, since the architecture of the polarizer 120, the first wave plate 130, the transflective element 140, the first lens 150, the second wave plate 160, and the polarizing reflector 170 is adopted, the image beam 112 can be folded back twice between the transflective element 140 and the polarizing reflector 170, that is, the image beam 112 can pass through the first lens 150 twice to greatly increase the magnification. Therefore, the light path and the magnification can be increased without enlarging the space occupied by the element. Therefore, the augmented reality display device 200 of the present embodiment can achieve a good optical effect using a small space, for example, such that a virtual image provided by the augmented reality display device 200 covers a wide range of fields of view. In the present embodiment, the first lens 150 and the second lens 180 are convex lenses, for example, plano-convex lenses, but other types of lenses, such as concave lenses, may be used in other embodiments. In addition, in other embodiments, the number of lenses between the reflective element 140 and the polarizing reflector 170 may be multiple. In another embodiment, a plurality of lenses may be used instead of the second lens 180.

In the present embodiment, the first lens 150 is configured to move between the first wave plate 130 and the second wave plate 160 to adjust the effective focal length of the first lens 150 and the second lens 180. The augmented reality display device 200 may further include an actuator 190 connected to the first lens 150 and configured to drive the first lens 150 between the first wave plate 130 and the second wave plate 160. In one embodiment, the actuator 190 is, for example, a motor.

Fig. 2 is a graph of the separation of the first lens and the second lens of fig. 1 relative to the focal length adjustment of an augmented reality display device. Referring to fig. 1 and 2, the lens pitch along the vertical axis of fig. 2 refers to the pitch between the first lens 150 and the second lens 180, which is measured in millimeters (millimeter, mm), and the focal length adjustment (focus accommodation) of the augmented reality display device along the horizontal axis is measured in diopters (diopter, D).

List one

Diopter of refraction

0D

-1D

-2D

-3D

-4D

-5D

Virtual image position

∞

1m

0.5m

0.33m

0.25m

0.2m

Lens spacing

5.65mm

4.67mm

3.67mm

2.67mm

1.67mm

0.70mm

The above table shows the relationship between the lens distance (i.e., the distance between the first lens 150 and the second lens 180), the virtual image position (i.e., the distance between the virtual image formed by the augmented reality display device 200 in front of the eye 60 and the diopter of the augmented reality display device 200. As can be seen from table one and FIG. 2, the smaller the lens distance, the closer the virtual image is to the eye 60 and the smaller the diopter, thus, by properly adjusting the lens distance, the distance of the virtual image can be changed, and when the virtual image distance is consistent with the focusing distance of the eye 60 (e.g., when the eye 60 focuses on an external object and the virtual image distance is adjusted to be consistent with the distance of the external object), the conflict of vision convergence adjustment can be effectively ameliorated.

Fig. 3 is a schematic structural view of an augmented reality display device according to another embodiment of the present invention. Referring to fig. 3, in actual use, one augmented reality display device 200 may be disposed in front of each of the two eyes 60 of the user, and both of the two augmented reality display devices 200 in front of the eyes may employ the augmented reality display device 200 of fig. 1. In the present embodiment, the augmented reality display device 200 further includes a camera 240 and a controller 230. The camera 240 is used to capture the eye 60. The camera 240 may be an infrared camera or a visible light camera, and the light from the eye 60 may be directly transferred to the camera 240 or transferred to the camera 240 through reflection of the surface of the light guide unit 210 as in fig. 3.

The controller 230 is electrically connected to the camera 230, the image source 110 (shown in fig. 1) and the actuator 190 of the first lens 150 (shown in fig. 1), and is configured to calculate a gaze point position of the eye 60 according to an image of the eye 60 captured by the camera 230. The controller 230 is then configured to determine the image content provided by the image source 110 according to the gaze point position, and to command the actuator 190 to dynamically adjust the position of the first lens 150 according to the image content. In this way, the position of the virtual image provided by the augmented reality display device 200 can be dynamically adjusted to be the same as the gaze point position of the eye 60, so as to effectively improve the convergence adjustment conflict. For example, when the camera 230 detects that the user's eyes 60 are looking at the external object 70, the controller 230 can command the image source 110 and the actuator 190 to adjust so that the virtual image formed by the augmented reality display device 200 is also located at the same distance as the object 70, so as to effectively solve the convergence adjustment conflict.

In one embodiment, the controller 230 is, for example, a central processing unit (central processing unit, CPU), a microprocessor (microprocessor), a digital signal processor (DIGITAL SIGNAL processor, DSP), a programmable controller, a programmable logic device (programmable logic device, PLD), or other similar devices or combinations of devices, which are not limiting. Furthermore, in one embodiment, the functions of the controller 230 may be implemented as a plurality of program codes. The program codes are stored in a memory and executed by the controller 230. Or in an embodiment, the functions of the controller 230 may be implemented as one or more circuits. The present invention is not limited to the implementation of the functions of the controller 230 in software or hardware.

In summary, in the augmented reality display device according to the embodiment of the present invention, since the structures of the polarizer, the first wave plate, the transflective element, the first lens, the second wave plate and the polarizing reflector are adopted, the image beam can be folded back twice between the transflective element and the polarizing reflector, and the optical path is further increased without enlarging the space occupied by the element. Therefore, the augmented reality display device of the embodiment of the present invention can achieve a good optical effect using a small space.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and not for limiting the same; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the invention.

Claims

1. An augmented reality display device to be worn in front of an eye of a user, the augmented reality display device comprising:

an image source for emitting an image beam;

A polarizing plate disposed on a path of the image light beam;

A first wave plate disposed on a path of the image light beam from the polarizing plate;

A transflective element disposed on a path of the image beam from the first wave plate;

a first lens disposed on a path of the image beam from the transflective element;

a second wave plate disposed on a path of the image beam from the first lens;

A polarizing reflection plate disposed on a path of the image light beam from the second wave plate;

a second lens disposed on a path of the image beam from the polarizing reflection plate;

A light guide unit disposed on a path of the image light beam from the second lens, wherein the light guide unit has a reflection surface; and

The curved transflective film is configured on the light guide unit, wherein the image light beam is reflected to the eyes of the user by the reflective surface and the curved transflective film in sequence after entering the light guide unit, and the light part from the external object penetrates through the curved transflective film and is transmitted to the eyes of the user.

2. The augmented reality display device of claim 1, wherein the transflective element is a transflective film disposed on a surface of the first lens facing the first wave plate.

3. The augmented reality display device of claim 2, wherein the transflective film is a transflective film.

4. The augmented reality display device of claim 1, wherein the first lens is to move between the first wave plate and the second wave plate to adjust an effective focal length of the first lens and the second lens.

5. The augmented reality display device of claim 1, wherein the first wave plate and the second wave plate are both quarter wave plates.

6. The augmented reality display device of claim 1, further comprising:

A camera to capture the eye; and

The controller is electrically connected to the camera, the image source and the actuator of the first lens, and is used for calculating the fixation point position of the eye according to the image of the eye shot by the camera, the controller is used for determining the image content provided by the image source according to the fixation point position, and the actuator is commanded to dynamically adjust the position of the first lens according to the image content.

7. The augmented reality display device of claim 1, wherein the image source is a display panel.

8. The augmented reality display device of claim 1, wherein the light guide unit is a light guide column and the curved transflector film is sandwiched in the light guide column.

9. The augmented reality display device of claim 1, wherein a concave surface of the curved transflector faces the eye.

10. The augmented reality display device of claim 1, wherein the curved transflective film is a transflective film.