CN110515212B

CN110515212B - Near-to-eye display system

Info

Publication number: CN110515212B
Application number: CN201910921643.2A
Authority: CN
Inventors: 程德文; 陈海龙
Original assignee: Beijing Ned+ Ar Display Technology Co ltd
Current assignee: Beijing Ned+ Ar Display Technology Co ltd
Priority date: 2019-09-27
Filing date: 2019-09-27
Publication date: 2021-12-14
Anticipated expiration: 2039-09-27
Also published as: CN110515212A

Abstract

The invention provides a near-eye display system, which comprises at least one reflection-type spectroscope which is not coaxial with the visual axis of a user, wherein the spectroscope is fixed at a preset position in front of the eyes of the user, the side facing the eyes of the user is coated with a reflection film with preset inverse transmission ratio, one end of the reflection film, which is close to the user, is more than 15mm away from the user. The near-to-eye display system is light in modeling, has a good display effect, can be adapted to users with different visual degrees, and is wide in application range.

Description

Near-to-eye display system

Technical Field

The invention relates to the technical field of augmented reality, in particular to a near-to-eye display system.

Background

As the concept of Virtual Reality (VR) and Augmented Reality (AR) has been proposed, the market of near-eye display devices based on VR or AR modes has also been greatly developed. Among the hardware implementations that apply AR or VR technology, head-Mounted Display (HMD) and Near-Eye Display (NED) are the most efficient implementations that bring the best experience to the user in the prior art.

A near-eye display is a head-mounted display that can project an image directly into the eye of a viewer. The display screen of the NED is close to human eyes and is smaller than the photopic distance, the human eyes cannot directly distinguish image contents on the display screen, the images can be approximately far away through the NED optical system and are refocused on retinas of the human eyes, and the images seen by the human eyes are as if the images are more than several meters, so that the display effect of the AR and VR technology is achieved.

Since the near-eye display needs to be worn on the head of a person, it is important to have a small size and a good display effect.

Disclosure of Invention

It is therefore a primary object of the present invention to provide a near-eye display system.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

a near-to-eye display system includes at least one reflection type spectroscope not coaxial with the visual axis of a user, the spectroscope is fixed at a predetermined position in front of the eye of the user, the side facing the eye of the user is coated with a reflection film of a predetermined inverse transmittance ratio, the end of the reflection film close to the user is more than 15mm away from the user.

Further, the beam splitter receives image light from a micro display, which is implemented by means of an LCD, OLED, LCoS, or MEMS scanning mirror.

Further, the micro-display is a curved display, in particular an OLED or MEMS implemented curved display, the convex surface of which emits image light.

Further, the near-to-eye display system further comprises a lens group and a reflecting mirror, wherein the reflecting mirror, the lens group and the micro display are sequentially arranged above the spectroscope from left to right; the lens group comprises at least one lens, and the optical axis of the lens and the optical axis of the micro display form a certain included angle; the reflector is a curved surface and forms a conjugate relation with the micro display.

Further, the side of the spectroscope facing the human eye is a curved surface.

Further, the near-eye display system further comprises a relay mirror that implements an image emitted by the microdisplay as a curved image.

Further, the curved image is an ideal image of the inner surface of the spectroscope to an infinite object.

Further, the near-eye display system further includes a diffuser screen that increases a transmission angle of the curved image.

Further, the relay lens is a micro lens array, and the curvature of the middle part of the micro lens array is larger than the curvatures of the upper area and the lower area.

Further, the inside and outside surfaces of the spectroscope are different, and the outside ambient light is formed into visibility which is matched with the visibility of a user.

By adopting the near-to-eye display system, the reflector is adopted to reflect the image light of the micro display, the volume of the display system is greatly reduced, and the image is amplified through the lens group, so that the display effect is improved. In addition, a curved intermediate image is further formed through an MEMS, a relay lens and a scattering screen in the near-eye display system, so that aberration is effectively improved, and imaging quality is further improved.

Drawings

Fig. 1 is a schematic structural diagram of a near-eye display system according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a near-eye display system according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a second near-eye display system according to an embodiment of the present invention;

fig. 4(a) and 4(b) are schematic structural diagrams of three near-eye display systems according to embodiments of the present invention;

FIG. 5(a) is a right side view of a triple relay lens in accordance with an embodiment of the present invention;

fig. 5(b) is a front view of a third relay lens according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

The invention is further described with reference to the following drawings and specific examples, which are not intended to be limiting.

The near-to-eye display system comprises a micro display and a spectroscope;

the micro display is used for emitting image light, the spectroscope reflects and amplifies the received image light to enter human eyes, and meanwhile, ambient light in an external environment enters the human eyes through the spectroscope, so that an augmented reality display effect is achieved. The micro display, the spectroscope and the human eye form a preset position and an angle, and the image light of the micro display is reflected by the spectroscope and then enters the human eye completely.

Example one

As shown in fig. 1 and 2, in a preferred embodiment of the present invention, the near-eye display system specifically includes:

at least one reflection-type spectroscope 102, the inner surface of which is a curved surface facing human eyes, and the reflection film with a preset transmission inverse ratio is coated on the reflection-type spectroscope 102, and the outer surface of which is a curved surface, wherein the preset transmission inverse ratio can be set according to requirements, so that the light intensity of an image reaching human eyes is moderate, and preferably, the light transmittance of the image is 30-50%; the curved surface can be a free curved surface, a cylindrical surface, an aspheric surface, a spherical surface and the like; the beam splitter 102 is fixed at a predetermined position in front of human eyes, the optical axis of the beam splitter is not coaxial with the visual axis of the human eyes, the included angle between the optical axis and the visual axis ranges from 15 degrees to 45 degrees, and preferably, the included angle is 25 degrees, so that more image light can be reflected into the human eyes.

The microdisplay 101 is disposed near the eye, and emits image light toward the beam splitter 102 at an angle toward the beam splitter 102, and the angle is set as required to ensure that the image light of the microdisplay is projected onto the beam splitter 102. In order to realize lightness and miniaturization, the microdisplay 101 can be selected from an LCD, an OLED and an Lcos microdisplay. The microdisplay 101 may be a flat panel display, as shown in FIG. 1; it may be a curved display as shown in fig. 2, in which the convex surface emits image light, and the aberration can be effectively corrected by using the curved display, and preferably, the curved surface of the curved display may be a free curved surface, a spherical surface, or an aspherical surface.

The image light emitted by the micro display 101 is partially reflected to enter human eyes after passing through the spectroscope 102, the image light of the micro display 101 is amplified and projected far by utilizing the surface shape and the curvature of the spectroscope 102, the image of the micro display seen at human eyes is emitted from a distance of several meters far rather than a very close place, and the external ambient light enters the human eyes through the spectroscope, so that the human eyes can simultaneously see the image light and the ambient light emitted by an image source, and the display effect of augmented reality is achieved.

Example two:

in another embodiment of the present invention, as shown in fig. 3, a reflecting mirror 303, a lens group 302, and a micro display 301 are arranged above a beam splitter 304 from left to right in the optical axis direction of the lens group 302.

The micro display 301 emits image light, which is amplified by the lens assembly 302, and then reflected by the reflecting mirror 303 to the beam splitter 304, and then partially reflected to the human eye by the beam splitter 304, and external ambient light enters the human eye by the beam splitter 304, so as to achieve the effect of augmented reality.

Specifically, the optical axis of the lens group 302 forms an angle with the optical axis of the microdisplay 301, preferably, the angle is smaller than 20 degrees, and the length of the lens group 302 in the y-axis direction is equal to or larger than the microdisplay 301 so as to receive the image light emitted from the entire microdisplay 301, and further, the distance between the microdisplay 301 and the lens group 302 is as small as possible, thereby reducing the size of the near-eye display system, preferably, the distance is smaller than 10 mm. The lens group 302 includes at least one lens, and the number and the shape of the lens are not limited as long as the image can be magnified. In the embodiment of the present invention, a convex lens is taken as an example, and the convex lens is a spherical surface.

The surface of the reflector 303 may be a plane, or a spherical surface, an aspheric surface, a free-form surface, etc., and may be matched with the beam splitter 304 to further correct aberration, thereby achieving a better display effect. The mirror 303 forms an approximately infinite conjugate relationship with the position of the microdisplay 301. In order to avoid the obstruction of the visual line, the mirror 303, the lens group 302, and the microdisplay 301 are out of the visual line of the human eye.

A spectroscope 304, the inner surface of which is a curved surface facing the human eye and coated with a reflecting film with a certain splitting ratio, and the outer surface of which is a curved surface; the curved surface can be a free curved surface, a cylindrical surface, an aspheric surface, a spherical surface and the like; the beam splitter 304 is fixed at a predetermined position in front of the human eye so as to reflect the image light into the human eye.

EXAMPLE III

In the present embodiment, the Micro display is a MEMS (Micro electro mechanical Systems) scanning mirror, and the near-eye display system further includes a beam splitter 404 and a relay mirror 402, wherein the relay mirror 402 and the MEMS scanning mirror 401 are sequentially arranged above the beam splitter 404 from left to right.

Specifically, as shown in fig. 4(a) and 4(b), the MEMS scanning mirror 401 generates an image signal by line-by-line scanning, projects the image signal to the relay mirror 402, and forms a curved image after passing through the relay mirror 402, so that the aberration can be effectively improved, and a clear image can be formed in human eyes, where the curved image is the same as an ideal image formed by the beam splitter 404 on an infinite object. In the present embodiment, the relay mirror 402 is implemented by a micro lens array, and those skilled in the art should understand that the implementation of the relay mirror 402 is not limited to this manner, and it is within the scope of the present invention as long as the relay mirror 402 can form a curved image for improving aberration. The microlens array in this embodiment can be divided into three regions, as shown in fig. 5(a) and 5(b), in this embodiment, the three regions are a1 in the upper region, a2 in the middle region, and A3 in the lower region, and the division ratio of the three regions can be set as needed. The curvature of each region is different, with the curvature of the middle portion a2 being greater than the curvature of the upper and lower regions a1 and A3.

The image light passes through the microlens array, the transmission angle is reduced, and when the image light is transmitted to the spectroscope 404, the effect is relatively poor, preferably, the near-eye display system in this embodiment further includes a scattering screen 403 which is located in the same horizontal direction as the relay mirror 402 and on the left side of the relay mirror 402, and the scattering screen 403 receives the image light emitted by the relay mirror at a certain angle; the angle can be set as required, and the scattering screen 403 is matched with the beam splitter 404 to transmit the received image light of the relay mirror 402 to the beam splitter 404.

And a diffusion screen 403 for diffusing the received image light of the microlens array to increase a transmission angle of the image light to ensure that the image light reaches the beam splitter 404 with a good display effect, and optionally, the diffusion screen 403 may be frosted glass.

A spectroscope 404 having an inner surface facing the human eye and coated with a reflective film having a certain splitting ratio, and an outer surface having a curved surface; the curved surface can be a free curved surface, a cylindrical surface, an aspheric surface, a spherical surface and the like; the beam splitter 404 is fixed at a predetermined position in front of the human eye.

In the first to third embodiments, the inverse transmittance ratio of the reflecting film on the inner surface of the spectroscope can be adjusted according to the microdisplay, so that the brightness of light entering human eyes is moderate; an anti-reflective material may also be applied to the outer surface of the beam splitter to reduce glare. The outer surface of the beam splitter is displaced from the inner surface along its main optical axis by a distance, which is the thickness of the beam splitter. Further, when the thickness distribution is not uniform, that is, the inner surface and the outer surface of the spectroscope are different, the thickness distribution can be provided for users with visibility problems. For example, the outer surface of the beam splitter may be optically treated to configure the glasses for visually impaired users, thereby varying the thickness, and the inner surface of the beam splitter may be optimized to eliminate distortions and deformations that may be caused by the optical treatment, thereby ensuring the quality of the image viewed by the user through the display system.

In summary, the present invention provides a near-eye display system design applying AR or VR technology, which designs the near-eye display system into a more compact structure and simultaneously realizes a larger field angle (over 55 degrees). All of the optical elements of the near-eye display system can be mounted to the HMD or NED device by mechanical mounts, making mechanical mounting and packaging of the entire system easier.

While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.

Claims

1. A near-eye display system comprising at least one reflective beam splitter not coaxial with the visual axis of a user, said beam splitter being fixed at a predetermined location in front of the eye of the user, the side facing the eye being coated with a reflective film having a predetermined inverse transmission ratio, the end thereof near the user being located at a distance of more than 15mm from the user;

the near-eye display system further comprises a relay mirror for receiving the image light from the microdisplay and implementing the image emitted by the microdisplay as a curved image; the relay lens is a micro-lens array, and the curvature of the middle part of the micro-lens array is greater than the curvatures of the upper area and the lower area;

the image light passing through the relay lens reaches the spectroscope, and the spectroscope reflects the received image light into human eyes.

2. The near-to-eye display system of claim 1 wherein the micro-display is implemented by way of an LCD, OLED, Lcos, or MEMS scanning mirror.

3. The near-to-eye display system of claim 2 wherein the microdisplay is a curved display with its convex surface emitting image light.

4. The near-to-eye display system of claim 1 wherein the beam splitter is curved toward the human eye.

5. The near-to-eye display system of claim 1 wherein the curved image is an ideal image of the spectroscopic inner surface onto an infinite object.

6. The near-eye display system of claim 1 further comprising a diffuser screen that increases the transmission angle of the curved image.

7. The near-to-eye display system of any one of claims 1-6 wherein the beam splitter has different inner and outer surfaces to provide a degree of visibility to ambient light to match a user's degree of visibility.

8. The near-eye display system of claim 1,

the included angle range of the optical axis of the spectroscope and the visual axis is 15-45 degrees.

9. The near-eye display system of claim 1,

the inverse transmission ratio of the reflecting film enables the image light transmission rate to be between 30% and 50%.

10. The near-eye display system of claim 6,

the scattering screen is frosted glass.