CN107765434B

CN107765434B - Single-image-source binocular near-to-eye display device

Info

Publication number: CN107765434B
Application number: CN201711118412.5A
Authority: CN
Inventors: 程德文
Original assignee: Beijing Ned+ar Display Technology Co ltd
Current assignee: Beijing NED+AR Display Technology Co.,Ltd.
Priority date: 2016-02-23
Filing date: 2016-02-23
Publication date: 2021-01-01
Anticipated expiration: 2036-02-23
Also published as: CN105572879A; CN105572879B; CN107765434A

Abstract

The invention relates to a single-image-source binocular near-to-eye display device, which is realized based on a free-form surface prism, realizes good binocular vision experience by the position matching of the free-form surface prism and a reflecting element under the condition of only using a single micro display element, has an ultrathin volume, can be used as a clamping piece type peripheral device to be attached to a main body frame or common correcting glasses, effectively reduces the cost of the near-to-eye display device, improves the user experience and promotes the popularization of the device.

Description

Single-image-source binocular near-to-eye display device

The invention relates to a divisional application of an invention patent application with the application number of 201610098428.8, the application date of 2016, 2 and 23 and the name of 'a single-image source binocular near-eye display device'.

Technical Field

The present invention relates to a free-form surface prism, and more particularly, to a free-form surface prism suitable for a single-image source near-eye display device, which can realize good binocular vision characteristics only by a small image display element having a high PPI and effectively reduce the cost of the near-eye display device, and a single-image source near-eye display device using the same.

Background

Consumer electronics have been developed vigorously in recent years, and after smart phones, consumers have generally known the concept of virtual reality (virtual reality) and augmented reality (augmented reality) and pursued related products as attempts to experience new technologies, and companies such as Microsoft, FACEBOOK, GOOGLE, etc. have introduced conceptual products in which a display element for one's eye alone, or two small and medium-sized display elements separated on the left and right eye viewing optical systems are mostly used, even though the two small and medium-sized display elements may be integrated into one piece, such as VR devices where Oculus and Samsung cooperate, but there is an inevitable need to use a VR device implanted in a large-area display (e.g. a mobile phone screen) as a whole, which is not economical compared to the demand for high PPI resolution display elements required by near-eye display devices, the manufacturing cost of the near-eye display device is greatly influenced, and good binocular vision characteristics cannot be realized under a light and thin optical system.

In order to reduce the use of display elements occupying a high proportion of the cost, some designs propose a spectroscope-based mode, and the light from the display element is divided into two beams by a spectroscope such as a semi-reflective semi-transparent spectroscope to enter a visual system of left and right eyes.

Disclosure of Invention

The invention aims to provide a single-image-source binocular near-eye display device which is realized based on a free-form surface prism, can realize good binocular vision experience by matching the positions of an effective optical surface and a reflecting element under the condition of only using a single miniature display element, has an ultrathin volume, and can be attached to a main body frame or common correction glasses as a clamping piece type peripheral.

The invention relates to a single-image source binocular near-eye display device, which comprises:

a micro display element;

a first free-form surface prism located on the left side and a second free-form surface prism located on the right side, the first and second free-form surface prisms including optical surfaces (32L, 32R) located on one side of the micro display element, the optical surfaces (32L, 32R) receiving image light incident toward optical surfaces (33L, 33R) of the first and second spherical mirrors and then totally reflecting to optical surfaces (31L, 31R) of the first and second free-form surface prisms facing the human eye direction, which totally reflects the image light to the optical surfaces (32L, 32R) again, and the image light is reflected by the optical surfaces (32L, 32R) to the optical surfaces (31L, 31R) of the first and second free-form surface prisms facing the human eye direction to exit;

the first spherical reflector is used for receiving the light emitted by the micro display element and reflecting the light to the first free-form surface prism and is positioned on the left side, and the second spherical reflector is used for receiving the light emitted by the micro display element and reflecting the light to the second free-form surface prism and is positioned on the right side;

the miniature display element is positioned on the midline of the first free-form surface prism and the second free-form surface prism, and the display surface is vertical to the midline, is opposite to the first spherical reflector and the second spherical reflector, and is parallel to the exit pupil; the lower edge positions of the reflecting surfaces of the first and second spherical reflecting mirrors do not protrude from the lower edge positions of the first and second free-form surface prisms, so that the thickness of the integral optical component is determined by the thicknesses of the first and second free-form surface prisms in the direction perpendicular to the micro display element.

According to a particular embodiment, the first and second freeform prisms are symmetrically disposed with respect to the midline and include a freeform surface (33L) facing the spherical mirror.

The first and second spherical reflectors are symmetrically distributed about the centerline and are arranged separately or integrally.

Preferably, the image light is reflected three times in the first and second free-form surface prisms and then exits through an optical surface (31L) of the first or second free-form surface prism.

According to the near-eye display device of the present invention, it may be formed in a sheet-like shape and have a jig; the microdisplay element is removable.

Furthermore, the near-eye display device of the invention also comprises a controller, an image file memory and a power supply which can be arranged in an external device, wherein the external device can be electrically connected to the micro display element and used for supplying power to the micro display element and controlling the image display on the micro display element.

The peripheral device may also include a user interface and a communication interface to receive user instructions and communicate with other devices.

3D display is achieved by providing controllable shutter elements in the optical paths of the left and right sides.

In order to improve the wearing comfort of the user, the outer shape of the near-eye display device includes a soft portion recess formed on the midline so as to be variable according to the face shape of the wearer.

The free-form surface prism has the advantages of being light, thin and easy to install, and under the matching of the positions of the reflecting elements, the light emitted by the miniature display element serving as a single image source can be reasonably distributed to the left free-form surface prism and the right free-form surface prism without enlarging the size of the whole optical system, so that the light energy utilization rate is improved, the weight and the volume of the device are reduced, the practicability and the comfort degree of near-to-eye display equipment are improved, and the cost for realizing various near-to-eye display devices such as VR (virtual reality), AR (augmented reality) and the like is reduced.

Drawings

FIG. 1 is an optical path diagram of a near-eye display device according to a first embodiment of the invention

FIG. 2 is an optical path diagram of a near-eye display device according to a second embodiment of the invention

FIG. 3 is an optical path diagram of a near-eye display device according to a variation of the present invention

FIG. 4 is a system block diagram of a near-eye display device electrically connected to an external device according to the present invention

Detailed Description

Practical examples of embodying the present invention will be discussed in detail below with reference to the drawings, the structure of a free-form surface prism, and the like. This invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art. In addition, the features of the embodiments may be combined in other ways than those described in the following embodiments, and the combined technical solutions still fall within the scope of the present application.

First embodiment

As shown in fig. 1, a cross-sectional view of a monocular binocular near-eye display device 100 according to a first embodiment of the present invention includes a micro display element 1I, and two sets of visual optical systems located on the left and right sides, it can be understood that the left and right sets of visual optical systems are symmetrically distributed about a central axis O of the micro display element 1I, and the central axis O of the micro display element 1I coincides with a central line of the left and right sets of visual optical systems. Hereinafter, the visual optics on the left side will be specifically described as objects of the present invention, and specific embodiments of the present invention will be explained.

The left visual optical system comprises a first free-form surface prism and a first reflector arranged opposite to the micro display element, the first reflector is a third free-form surface prism, and the first free-form surface prism and the third free-form surface prism both comprise 3 optical surfaces. For convenience of expression, a reverse light path direction is adopted, the light is transmitted into the first free-form surface prism through the optical surface 11L from the human eye direction to the micro display element, is incident on the optical surface 12L and reflected back to the optical surface 11L, is totally internally reflected again on the optical surface 11L to reach the optical surface 13L, is transmitted to the optical surface 14L to enter the third free-form surface prism, is totally internally reflected to the optical surface 16L through the optical surface 15L, is reflected again on the optical surface 16L, and is emitted through the optical surface 15L to reach the micro display 1I. The powers of the

optical surfaces

12L, 13L, 15L and 16L are positive, and the powers of the optical surfaces 11L and 14L are negative.

As will be understood by those skilled in the art, the right viewing optics are symmetrically disposed with respect to the left, and include second and fourth free-form curved prisms, with each optical surface 11R-16R being disposed opposite to, and having a consistent effect on, 11L-16L. The incidence surfaces 11L and 11R of the first free-form surface prism and the second free-form surface prism are arranged opposite to human eyes, and the micro display 1I is positioned in the center of the two eyes and is parallel to the exit pupil of an optical system formed by the first free-form surface prism and the third free-form surface prism (or the second free-form surface prism and the fourth free-form surface prism). To avoid the influence of other rays in the field of view, a stop G may be added, which may be located at the exit pupil position of the whole optical system.

Further, when the first embodiment of the present invention is used as an AR-type display device, the present invention may further include a wedge-shaped compensation prism located above the first free-form surface prism, where the compensation prism includes an outer surface 17L, and the wedge-shaped prism formed by the optical surfaces 12L and 17L and the first free-form surface prism form an afocal system for projecting light to the outside, at this time, the semi-reflective and semi-transparent films are plated on the

optical surfaces

12L and 12R, the total reflection films are plated on the optical surfaces 16L and 16R, and the outside light enters the wedge-shaped compensation prism through the optical surface 17L, and further enters human eyes through the optical surface 11L after being transmitted by the optical surface 12L.

The individual curved prisms of the present invention may also include other surfaces as needed for ease of manufacture and installation, but are not discussed as optical surfaces in the present invention, as such surfaces typically do not have optical transmission or reflection effects and are treated, such as frosted.

It will be understood by those skilled in the art that the optical surfaces 11L and 11R facing the eyes of the user may be coated with a protective film for removing harmful light to prevent damage to the eyesight of the human eye. When the optical surface is used as a simple VR near-eye display device, the outer sides of the surfaces of the

optical surfaces

12L and 12R can be plated with reflecting films, so that the light total reflection efficiency is ensured, external light is effectively prevented from entering the inside of the free-form surface prism, and the influence of stray light on the display effect is avoided.

Various optical surface parameters according to the first embodiment of the present invention can be represented by the following tables 1-1 and 1-2,

surface marking	Surface type	Radius of	Material	X eccentricity	Y eccentricity	Z eccentricity	Alpha tilt
								Diaphragm G	Spherical surface	Infinite number of elements		0	0	0	0
11	Spherical surface	-1000	PMMA	0	0.000	37.218	-3.000
								12	XY polynomial	-48.9221	PMMA	0	0.000	42.100	-31.355
13	Spherical surface	-56.6915		0	14.717	41.846	33.057
								14	Spherical surface	-20	PMMA	0	17.842	42.977	81.506
15	Spherical surface	-55.0243	PMMA	0	23.556	44.627	16.256
								16	XY polynomial	8.704021	PMMA	0	28.386	39.144	-11.982
Display element	Spherical surface	Infinite number of elements		0	32.000	52.207	0.000
								17	Spherical surface	-1000	PMMA	0	0.000	46.218	-3.000

Table 1-1 wherein surface 12 and surface 16 are free surfaces defined by XY polynomials, the coefficients are shown in tables 1-2:

tables 1 to 2

Second embodiment

Similar to the first embodiment, the second embodiment of the present invention also includes first to fourth free-form surface prisms as shown in fig. 2, and the first free-form surface prism and the third free-form surface prism located on the left side of the micro display device 2I each include 3 optical surfaces, as exemplified on the left side. For convenience of expression, a reverse light path direction is adopted, the light is transmitted into the first free-form surface prism through the optical surface 21L from the human eye direction to the micro display element, is incident on the optical surface 22L and is totally reflected back to the optical surface 21L, is totally reflected again on the optical surface 21L to reach the optical surface 23L, is transmitted to the optical surface 24L to enter the third free-form surface prism, is totally reflected to the optical surface 26L through the optical surface 25L, is totally reflected again on the optical surface 26L, and is emitted to the micro display 2I through the optical surface 25L. The difference from the first embodiment is that the third and fourth prisms in the second embodiment are integrally formed by curved prisms or are separately formed and then glued together, which facilitates alignment during installation.

Each optical surface parameter according to the second embodiment of the present invention can be represented by the following tables 2-1 and 2-2,

	surface type	Radius of	Material	X eccentricity	Y eccentricity	Z eccentricity	Alpha tilt
								Diaphragm	Spherical surface	Infinite number of elements		0	0	0	0
21	Spherical surface	243.1243	PMMA	0	0.000	37.113	-2.085
								22	XY polynomial	-59.7016	PMMA	0	0.000	42.209	-32.456
23	Spherical surface	-24.5515		0	15.108	41.533	47.129
								24	Spherical surface	-20	PMMA	0	18.060	43.234	87.684
25	Spherical surface	-142.2	PMMA	0	23.324	45.194	14.177
								26	XY polynomial	10.22588	PMMA	0	28.302	39.512	-12.831
Display element	Spherical surface	Infinite number of elements		0	32.000	53.170	0.000

TABLE 2-1

Wherein the surface 22 and the surface 26 are free surfaces defined by XY polynomials with coefficients as shown in tables 2-2

	Surface 22	Surface 26
			K	0	0
C1	0.0000E+00	0.0000E+00
			C2	0.0000E+00	0.0000E+00
C3	-5.5632E-03	-1.6637E-02
			C4	0.0000E+00	0.0000E+00
C5	5.6491E-04	-2.1873E-02
			C6	0.0000E+00	0.0000E+00
C7	-3.4392E-04	2.1347E-05
			C8	0.0000E+00	0.0000E+00
C9	-2.6616E-04	7.5567E-05
			C10	1.6003E-05	-7.8927E-05
C11	0.0000E+00	0.0000E+00
			C12	1.1341E-07	-2.5913E-04
C13	0.0000E+00	0.0000E+00
			C14	4.4197E-06	-1.6109E-04
C15	0.0000E+00	0.0000E+00
			C16	-7.8704E-08	7.5637E-06
C17	0.0000E+00	0.0000E+00
			C18	-7.6329E-07	2.7544E-06
C19	0.0000E+00	0.0000E+00
			C20	-1.8518E-07	0.0000E+00

Tables 2 to 2

According to the above-described embodiment of the present invention, when the self-curved surface prism is used as the reflecting mirror, the lower edge thereof does not protrude from the lower edges of the first and second free-form surface prisms, such an arrangement may allow the thickness of the unitary optical component to be determined by the thickness of the first and second free-form surface prisms in a direction perpendicular to the microdisplay element, and the thickness of the first and second free-form surface prisms (shown by dotted lines in fig. 1-2) may preferably be up to a level of about 8mm according to the above-described embodiments of the present invention, achieving slimness and thinness of the device, and in view of this, its weight can set up to the clamping piece form of peripheral hardware completely, and accessible structure such as similar anchor clamps is attached to on the all kinds of correction glasses that the user wore (for example wear the user who has the correction myopia glasses), can not increase too big burden for the user to be applicable to more manifold scenes.

In particular, since the two mirrors are inclined inward at the incident surfaces facing the micro display elements, and have an inverted "eight" shape, it is possible to provide a sufficient space for the installation of the micro display elements while the device is being slimmed, the micro display elements may be selected from various types of micro display elements having a high PPI, including but not limited to LCD type, LCOS type, and OLED type, and such display elements may exist as modular installation, and when the technology of the display elements is developed, replacement may be achieved by disassembling the display elements as modular, so that the near-eye display device of the present invention may always use the most advanced display elements, and if the optical system is customized by the user according to his visual needs, such an arrangement is advantageous for the long-term use of the device.

In order to ensure image quality, the first to fourth free-form surface prisms of the above embodiments each include at least one free surface defined by an xy polynomial, and it is preferable that the surfaces 12, 22, 32, 42, 52 that perform total internal reflection on the side of the microdisplay element among the first and second free-form surface prisms be free surfaces, and that the surfaces 16, 26, 36, 46, 56 that perform total internal reflection on the side away from the microdisplay element among the third and fourth free-form surface prisms be free surfaces. Further, all surfaces can be provided with free surfaces defined by xy polynomials for better optimization of image quality, but the corresponding manufacturing costs will increase.

Modification example

According to the above embodiment of the present invention, the mirror disposed facing the micro display element 3I is a pair of spherical mirrors, and the reflecting surface thereof is spherical and disposed facing the micro display element. Expressed by adopting a reverse light path direction, light rays are transmitted from the human eye direction to the micro display element through the optical surface 31L, enter the first free-form surface prism, are incident on the optical surface 32L and are totally reflected back to the optical surface 31L, are subjected to the generation of the total internal reflection on the optical surface 31L and reach the optical surface 32L again, are totally reflected through the optical surface 32L, are transmitted out of the first free-form surface prism through the optical surface 33L to the reflecting surface of the spherical reflector 34L, and are totally reflected through the optical surface 34L to reach the micro display 3I. According to the first and second free-form surface prisms according to the modified examples of the present invention, the image light emitted from the micro display device 3I enters the free-form surface prisms and is reflected 3 times.

Due to the above arrangement when using a spherical mirror, the distance of the micro-display element 6I from the spherical mirror can be further compressed, and since the weight of the spherical mirror can usually be smaller than the prism, the weight of the device can also be further reduced, but it has to be taken into account that the spherical mirror is slightly more difficult to mount than the prism.

When the near-eye display device of the present invention is used, the micro display element is used as an image display, and the controller, the image file memory, the power supply and the like of the micro display element can be disposed in an external device, as shown in fig. 4, the external device is electrically connected to the micro display element to supply power to the micro display element and control image display on the micro display element.

Further, the peripheral device may also include a user interface and a communication interface to receive user instructions and communicate with other devices. In one form, the peripheral device may be a general purpose computing device such as a PC, tablet, smart phone, etc., on which various functions and applications may be displayed using the display device of the present invention. Taking a smartphone as an example, it includes, for example, a general purpose processor, a memory that includes applications and non-volatile storage, the processor may implement communications as well as any number of applications and act as a controller. The memory may include various types of semiconductor memory devices of nonvolatile and volatile memories. The user interface for operation may implement the functionality of a user interface, a communication interface such as wireless communication interfaces WIFI, bluetooth, NFC, etc., as well as various known limited communication interfaces that may communicate with and receive data information from other devices.

In another form, the peripheral device may use dedicated components such as controllers and memory to achieve better display performance and develop personalized functionality, such as various industrial applications.

When the micro display element supports 3D display, the near-eye display device can support 3D display; or by adding controllable shutter elements in the light paths to the left and right sides, a 3D display is achieved.

According to the near-to-eye display device, a good binocular display effect under a single image source is achieved based on the prism comprising the free surface, and the device is light and thin. As an alternative, when the near-eye display device of the present invention has the shape of glasses and is worn on the head of a user, the micro display element is located right at the bridge of the nose, the first and second separate reflectors can be placed on both sides of the bridge of the nose by effectively using the contour of the face of the user, and the shape of the near-eye display device is formed as a soft depression at the bridge of the nose, which can be changed according to the face shape of the wearer, so that the micro display element can be effectively close to the face of the user, and an advantageous condition is provided for realizing the appearance of a product with a design feeling.

The foregoing is illustrative of the present invention and is not to be construed as limiting thereof in any way. Any simple modification, equivalent change and modification made to the above embodiments according to the technical spirit of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A single image source binocular near-eye display device comprising:

a micro display element;

a first free-form surface prism and a second free-form surface prism;

the first spherical reflector is used for receiving the light emitted by the micro display element and reflecting the light to the first free-form surface prism, and the first spherical reflector and the first free-form surface prism are positioned on the left side of the micro display element;

the second spherical reflector is used for receiving the light emitted by the micro display element and reflecting the light to the second free-form surface prism, and the second spherical reflector and the second free-form surface prism are positioned on the right side of the micro display element;

the micro display element is positioned on a center line of the first and second free-form surface prisms, the display surface is arranged perpendicular to the center line,

the first spherical reflector and the second spherical reflector are opposite and parallel to the exit pupil;

the first and second free-form surface prisms include optical surfaces (32L, 32R) on a side of the micro display element, the optical surfaces (32L, 32R) on the side of the micro display element receive the image light incident toward the optical surfaces (33L, 33R) of the first and second spherical mirrors and then totally reflect to the optical surfaces (31L, 31R) of the first and second free-form surface prisms facing the human eye direction, the optical surfaces facing the human eye direction totally reflect the image light again, and the optical surfaces (31L, 31R) facing the human eye direction reflected by the optical surfaces (32L, 32R) on the side of the micro display element to the first and second free-form surface prisms exit;

the lower edge positions of the reflecting surfaces of the first and second spherical reflecting mirrors do not protrude from the lower edge positions of the first and second free-form surface prisms, so that the thickness of the integral optical component is determined by the thicknesses of the first and second free-form surface prisms in the direction perpendicular to the micro display element.

2. The near-eye display device of claim 1, wherein the first and second spherical mirrors are symmetrically distributed about the centerline and are integrally disposed.

3. The near-eye display device of claim 1 wherein the near-eye display device is formed in a sheet-like shape and has a clip.

4. The near-eye display device of claim 1 wherein the microdisplay element is removable.

5. The near-eye display device of claim 1, further comprising a controller, an image file memory, and a power supply positionable in an external device, the external device being electrically connectable to the microdisplay elements for powering the microdisplay elements and controlling the display of images on the microdisplay elements.

6. The near-eye display device of claim 5 wherein the peripheral device further comprises a user interface and a communication interface to receive user instructions and to communicate with other devices.

7. The near-eye display device of claim 6, wherein 3D display is achieved by providing controllable shutter elements in the left and right light paths.

8. The near-eye display device of claim 1, wherein the near-eye display device profile comprises a flex depression formed on the midline that varies with the wearer's face.