阅读说明：本技术 衍射光波导ar系统、ar眼镜及其系统的配置方法 (Diffractive light waveguide AR system, AR glasses, and method for configuring system ) 是由 韩娜 王晨如 董瑞君 马占山 武玉龙 栗可 白家荣 黄海涛 于 2021-09-01 设计创作，主要内容包括：本公开实施例提供了一种衍射光波导AR系统、AR眼镜及其系统的配置方法,系统包括：显示单元、准直透镜组、反射镜、耦入光栅、光波导板、耦出光栅；其中,准直透镜组,用于将显示单元射出的光进行光束准直处理,并将处理后的平行光传输至反光镜上；反射镜,用于将入射的平行光反射至耦入光栅；耦入光栅,用于将入射的平行光耦入至光波导板中进行全反射；耦出光栅,用于接收来自光波导板的全反射光,并射出全反射光。本公开实施例将准直透镜组出射的平行光光路折转,最终使光线垂直入射到光波导的耦入光栅区域,可以减小耦入光栅与耦出光栅之间的距离,以增大FOV及Eyebox的大小,增强视觉效果。(The disclosed embodiments provide a diffractive light waveguide (AR) system, AR glasses and a configuration method of the system, wherein the system comprises: the display unit, the collimating lens group, the reflector, the coupling-in grating, the optical waveguide plate and the coupling-out grating; the collimating lens group is used for carrying out beam collimation treatment on the light emitted by the display unit and transmitting the treated parallel light to the reflector; a reflector for reflecting the incident parallel light to the incoupling grating; the coupling-in grating is used for coupling the incident parallel light into the optical waveguide plate for total reflection; and the coupling-out grating is used for receiving the total reflection light from the optical waveguide plate and emitting the total reflection light. The embodiment of the disclosure turns the light path of the parallel light emitted by the collimating lens group, finally makes the light vertically incident to the coupling grating area of the optical waveguide, and can reduce the distance between the coupling grating and the coupling grating, so as to increase the size of the FOV and the Eyebox and enhance the visual effect.)

1. A diffractive light waveguide, AR, system, comprising:

the display unit, the collimating lens group, the reflector, the coupling-in grating, the optical waveguide plate and the coupling-out grating; wherein the content of the first and second substances,

the collimating lens group is used for carrying out beam collimation treatment on the light emitted by the display unit and transmitting the treated parallel light to the reflector;

the reflector is used for reflecting incident parallel light to the incoupling grating;

the incoupling grating is used for incoupling incident parallel light into the optical waveguide plate for total reflection;

the coupling-out grating is used for receiving total reflection light from the optical waveguide plate and emitting the total reflection light.

2. The diffractive light waveguide AR system according to claim 1, characterized in that said mirrors are total reflection mirrors.

3. The diffractive light waveguide AR system according to claim 1, characterized in that said total reflection mirror comprises at least one of: a plane reflector, a secondary reflection prism and a trapezoidal prism.

4. The diffractive light waveguide AR system according to any of claims 1 to 3, characterized in that the width and height of the outcoupled grating under human eye head-up field of view are determined according to target parameters, wherein said target parameters comprise at least: eye movement range Eye Box, pupil distance ERF, field of view area FOV.

5. The diffractive light waveguide AR system of claim 4, wherein said out-coupling grating has a width W in a human eye head-up field of view_outAnd height H_outThe following formula is satisfied:

W_out＝Eyebox_W+2ERF×tan(FOV_W/2)；

H_out＝Eyebox_H+2ERF×tan(FOV_H/2)；

wherein, Eyebox_WEye box width of eye movement_HHeight of eye movement range, ERF pupil distance, FOV_WIs the width of the field of view, FOV_HIs the height of the field of view region.

6. The diffractive light waveguide AR system according to claim 5, wherein the width and height of said in-coupling grating are determined according to the exit azimuth angle of the exit light of said in-coupling grating, a predetermined pitch between said in-coupling grating and said out-coupling grating, and the width and height of said out-coupling grating.

7. The diffractive optical waveguide AR system of claim 6, wherein said incoupling grating has a width W_inAnd height W_inThe following formula is satisfied:

wherein the content of the first and second substances,d is a predetermined distance between the incoupling grating and the outcoupling grating.

8. The diffractive light waveguide AR system of claim 7,determined according to the following formula:

where θ is the diffraction angle of incident light coupled into the grating,and j is an imaginary number, Λ is the period of the coupling-in grating, and λ is the wavelength of the incident light.

9. AR eyewear, comprising: the diffractive light waveguide AR system of any one of claims 1 to 8.

10. A method of configuring a diffractive light waveguide AR system, which is used for the diffractive light waveguide AR system according to any one of claims 1 to 9, comprising:

determining a target parameter, wherein the target parameter at least comprises: eye movement range Eye Box, pupil distance ERF, field of view area FOV;

determining the width and height of the coupled grating in the eye level vision according to the target parameters;

determining an emergent azimuth angle of emergent light coupled into the grating according to an incident azimuth angle and an incident diffraction angle of incident light coupled into the grating, a period of the coupled grating and a wavelength of the incident light;

and determining the width and height of the coupling-in grating according to the width and height of the coupling-out grating, the emergent azimuth angle and the preset interval between the coupling-in grating and the coupling-out grating.

Technical Field

The present disclosure relates to the field of optics, and more particularly, to a diffractive light waveguide AR system, AR glasses, and a method of configuring the system.

Background

The conventional diffractive light waveguide AR system includes a microdisplay screen, a collimating lens set, an incoupling grating, a light guide plate, and an outcoupling grating. The micro display screen is used for outputting a light beam corresponding to the virtual image; the lens is used for beam collimation; the coupling grating is used for coupling the parallel light into the waveguide for total reflection; the coupling grating is used for emitting the total reflection light to human eyes.

In the existing diffraction optical waveguide AR glasses, in order to ensure that an image generated by a micro display screen vertically enters an optical waveguide sheet, a scheme that a collimating lens must be directly opposite to an incoupling grating is adopted. The positions of the glasses legs of the AR glasses are fixed, when the glasses are watched by human eyes, pupils need to face the middle position of the coupling grating, but due to the fact that the size of the optical machine (the micro display screen and the collimating lens group) is relatively large, in order to avoid interference between the optical machine and the human face, the distance between the coupling grating and the coupling grating is large, the field of view (FOV) and the eye movement range (Eyebox) are very small, and the system performance is low.

Disclosure of Invention

In view of the above, the embodiments of the present disclosure provide a diffractive light waveguide AR system, AR glasses and a configuration method of the system, so as to solve the following problems in the prior art: the size of the existing optical machine is relatively large, so that the distance between the coupling-in grating and the coupling-out grating is large in order to avoid interference between the optical machine and a human face, the field area and the eye movement range are very small, and the system performance is low.

In one aspect, an embodiment of the present disclosure provides a diffractive light waveguide AR system, including: the display unit, the collimating lens group, the reflector, the coupling-in grating, the optical waveguide plate and the coupling-out grating; the collimating lens group is used for carrying out beam collimation treatment on the light emitted by the display unit and transmitting the treated parallel light to the reflector; the reflector is used for reflecting incident parallel light to the coupling grating; the coupling-in grating is used for coupling the incident parallel light into the optical waveguide plate for total reflection; and the coupling-out grating is used for receiving the total reflection light from the optical waveguide plate and emitting the total reflection light.

In some embodiments, the mirror is a total reflection mirror.

In some embodiments, the total reflection mirror comprises at least one of: a plane reflector, a secondary reflection prism and a trapezoidal prism.

In some embodiments, the width and height of the coupled-out grating at the eye-level-up field of view is determined from target parameters, wherein the target parameters include at least: eye movement range, pupil distance, field of view area.

In some embodiments, the width W of the outcoupling grating in the field of view at human eye level_outAnd height H_outThe following formula is satisfied:

W_out＝Eyebox_W+2ERF×tan(FOV_W/2)；

H_out＝Eyebox_H+2ERF×tan(FOV_H/2)；

wherein, Eyebox_WEye box width of eye movement_HHeight of eye movement range, ERF pupil distance, FOV_WIs the width of the field of view, FOV_HIs the height of the field of view region.

In some embodiments, the width and height of the incoupling grating are determined according to the emission azimuth angle of the emergent light of the incoupling grating, the predetermined interval between the incoupling grating and the outcoupling grating, and the width and height of the outcoupling grating.

In some embodiments, the width W of the incoupling grating_inAnd height W_inThe following formula is satisfied:

wherein the content of the first and second substances,d is a predetermined distance between the incoupling grating and the outcoupling grating.

In some embodiments of the present invention, the,determined according to the following formula:

where θ is the diffraction angle of incident light coupled into the grating,and j is an imaginary number, Λ is the period of the coupling-in grating, and λ is the wavelength of the incident light.

In another aspect, an embodiment of the present disclosure provides an AR glasses, including: the diffractive optical waveguide AR system according to any of the embodiments of the present disclosure.

On the other hand, the embodiments of the present disclosure provide a configuration method of a diffractive light waveguide AR system, which is used for the diffractive light waveguide AR system according to any one of the embodiments of the present disclosure, and includes: determining a target parameter, wherein the target parameter at least comprises: eye movement range, pupil distance, field of view area; determining the width and height of the coupled grating in the eye level vision according to the target parameters; determining an emergent azimuth angle of emergent light coupled into the grating according to an incident azimuth angle and an incident diffraction angle of incident light coupled into the grating, a period of the coupled grating and a wavelength of the incident light; and determining the width and height of the coupling-in grating according to the width and height of the coupling-out grating, the emergent azimuth angle and the preset interval between the coupling-in grating and the coupling-out grating.

The reflector is added in the AR system, the original light path is changed through the reflector, the position of the existing optical machine which needs to be vertically placed is changed, the position can be adjusted at will, the number of the reflectors can be set at will, and the condition that the incident light coupled into the grating is collimated parallel light can be met; the embodiment of the disclosure converts the parallel light path emitted by the collimating lens group, finally makes the light vertically incident to the coupling grating area of the optical waveguide, and the optical machine placed at other positions cannot generate excessive interference with the human face, so that the distance between the coupling grating and the coupling grating can be reduced, the area of the coupling grating is increased, the size of the FOV and the Eyebox is increased, and the visual effect is enhanced.

Drawings

In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, it is obvious that the drawings in the following description are only some embodiments described in the present disclosure, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic diagram of a prior art diffractive optical waveguide AR system;

FIG. 2 is a schematic diagram of a diffractive light waveguide AR system provided by an embodiment of the present disclosure;

fig. 3 is a wave vector diagram of incident light and a structure of a diffraction grating provided in an embodiment of the present disclosure;

fig. 4 is a schematic diagram illustrating a relationship between an in-grating and an out-grating according to an embodiment of the present disclosure.

Reference numerals:

1-display unit, 2-collimating lens group, 3-reflector, 4-coupling-in grating, 5-optical waveguide plate and 6-coupling-out grating.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present disclosure more clear, the technical solutions of the embodiments of the present disclosure will be described below clearly and completely with reference to the accompanying drawings of the embodiments of the present disclosure. It is to be understood that the described embodiments are only a few embodiments of the present disclosure, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the described embodiments of the disclosure without any inventive step, are within the scope of protection of the disclosure.

Unless otherwise defined, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this disclosure belongs. The use of "first," "second," and similar terms in this disclosure is not intended to indicate any order, quantity, or importance, but rather is used to distinguish one element from another. The word "comprising" or "comprises", and the like, means that the element or item listed before the word covers the element or item listed after the word and its equivalents, but does not exclude other elements or items. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "upper", "lower", "left", "right", and the like are used merely to indicate relative positional relationships, and when the absolute position of the object being described is changed, the relative positional relationships may also be changed accordingly.

To maintain the following description of the embodiments of the present disclosure clear and concise, a detailed description of known functions and known components have been omitted from the present disclosure.

Fig. 1 shows a prior art diffraction optical waveguide AR system, and it can be seen from fig. 1 that the collimating lens faces the coupling-in grating, and in order to avoid interference with a human face, the distance D between the coupling-in grating and the coupling-out grating is large, so that the coupling-out grating must have a small area, and the FOV and Eyebox are very small.

In order to solve the existing problems, a first embodiment of the present disclosure provides a diffractive light waveguide AR system, a structural schematic of which is shown in fig. 2, including:

the device comprises a display unit 1, a collimating lens group 2, a reflector 3, an incoupling grating 4, an optical waveguide plate 5 and an outcoupling grating 6; the collimating lens group 2 is used for performing beam collimation processing on light emitted by the display unit 1 and transmitting the processed parallel light to the reflector 3; the reflector 3 is used for reflecting the incident parallel light to the coupling grating 4; an incoupling grating 4 for coupling the incident parallel light into the optical waveguide plate 5 for total reflection; and a light coupling grating 6 for receiving the totally reflected light from the optical waveguide plate 5 and emitting the totally reflected light.

The reflector is added in the AR system, the original light path is changed through the reflector, the position of the existing optical machine which needs to be vertically placed is changed, the position can be adjusted at will, the number of the reflectors can be set at will, and the condition that the incident light coupled into the grating is collimated parallel light can be met; the embodiment of the disclosure converts the parallel light path emitted by the collimating lens group, finally makes the light vertically incident to the coupling grating area of the optical waveguide, and the optical machine placed at other positions cannot generate excessive interference with the human face, so that the distance between the coupling grating and the coupling grating can be reduced, the area of the coupling grating is increased, the size of the FOV and the Eyebox is increased, and the visual effect is enhanced.

In a specific implementation, fig. 2 is only an example, and the optical-mechanical position formed by the display unit and the collimating lens group can be arbitrarily set by adjusting the number and the position of the reflecting mirrors; in order to ensure the best reflection effect, the reflector is preferably a total reflector, such as a plane reflector, a secondary reflector prism, a trapezoidal prism, and the like.

Since the predetermined spacing between the coupling-in grating and the coupling-out grating is sufficient for no interference to occur, a large coupling-out grating can be provided, in particular the width and height of the coupling-out grating in the eye-level viewing field being determined according to target parameters, wherein the target parameters include at least: eye movement range Eye Box, pupil distance ERF, field of view area FOV.

When implemented, the width W of the out-coupling grating under the human eye head-up field of view_outAnd height H_outThe following formula is satisfied:

W_out＝Eyebox_W+2ERF×tan(FOV_W/2)；

H_out＝Eyebox_H+2ERF×tan(FOV_H/2)；

wherein, Eyebox_WEye box width of eye movement_HHeight of eye movement range, ERF pupil distance, FOV_WIs the width of the field of view, FOV_HIs the height of the field of view region.

The width and height of the incoupling grating are determined according to the emergent azimuth angle of emergent light of the incoupling grating, the preset spacing between the incoupling grating and the outcoupling grating, and the width and height of the outcoupling grating. In practice, the width W of the incoupling grating_inAnd height W_inThe following formula is satisfied:

wherein the content of the first and second substances,d is a predetermined distance between the incoupling grating and the outcoupling grating.

For theCan be determined according to the following formula:

where θ is the diffraction angle of incident light coupled into the grating,and j is an imaginary number, A is the period of the coupling-in grating, and lambda is the wavelength of the incident light.

The configuration of the above embodiment will be further described with reference to the drawings.

The Eyebox, FOV, ERF, the predetermined spacing D between the incoupling grating and the outcoupling grating are all predetermined, which is generally determined according to the user's needs; the calculation of the lateral and vertical dimensions of the coupled-out grating is as follows,

W_out＝Eyebox_W+2ERF×tan(FOV_W/2)；

H_out＝Eyebox_H+2ERF×tan(FOV_H/2)；

in the formula, Eyebox_WEye box width of eye movement_HHeight of eye movement range, ERF pupil distance, FOV_WIs the width of the field of view, FOV_HIs the height of the field of view region.

The light is diffracted by the coupling grating and then is totally reflected in the optical waveguide, and the diffraction angle theta_jAnd azimuth angleThe calculation formula is as follows:

the structure of the diffraction grating and the wave vector diagram of the incident light are shown in fig. 3, and the wave vector formula of the incident light is:

wherein, theta is the incident diffraction angle of the incident light,is the incident azimuth angle of the incident light.

After the incident light passes through the coupling grating, the wave vector formula in the xy direction is as follows:

k_yj＝k_y；

through derivation, the calculation formulas of the emergent diffraction angle and the emergent azimuth angle of emergent light are as follows:

where is an imaginary number, Λ is the period of the incoupling grating, λ is the wavelength of the incident light, n₂Is the refractive index of the optical waveguide plate.

The dimensions of the transverse and vertical incoupling gratings can be determined according to the above target parameters and the predetermined spacing D between the incoupling grating and the outcoupling grating, which is schematically shown in fig. 4, and the formula is as follows:

from the above formula, it can be seen that the size of the exit pupil aperture of the collimating lens group is determined by the size of the transverse and vertical coupling grating; the ERF exit pupil distance is generally determined according to the normal viewing distance of human eyes, and is about 18 mm; the value of the distance D between the incoupling grating and the outcoupling grating is inversely proportional to the FOV or Eyebox size, the larger the value of D, the smaller the FOV or Eyebox value.

Therefore, the scheme of reducing D is adopted in the scheme, the total reflection mirror is added between the collimating lens group and the coupling grating, the light path is turned, the human engineering design can be met on the premise of not influencing the image quality, the FOV and the Eyebox size can be increased, and the visual experience is enhanced.

Embodiments of the present disclosure also provide AR glasses including at least the diffractive light waveguide AR system in the above-described embodiments of the present disclosure. Of course, it is not limited to AR glasses, and may be an AR headset or the like.

The embodiment of the present disclosure further provides a configuration method of a diffractive light waveguide AR system, which is used for the above diffractive light waveguide AR system, and may include the following processes:

(1) determining a target parameter, wherein the target parameter at least comprises: eye movement range Eye Box, pupil distance ERF, field of view area FOV;

(2) determining the width and height of the coupled grating in the eye level vision according to the target parameters;

(3) determining an emergent azimuth angle of emergent light coupled into the grating according to an incident azimuth angle and an incident diffraction angle of incident light coupled into the grating, a period of the coupled grating and a wavelength of the incident light;

(4) and determining the width and height of the coupling-in grating according to the width and height of the coupling-out grating, the emergent azimuth angle and the preset interval between the coupling-in grating and the coupling-out grating.

In the implementation, when the width and the height of the coupled grating are determined according to the target parameters during the eye level vision, the width W is determined according to the following formula_outAnd height H_out：

W_out＝Eyebox_W+2ERF×tan(FOV_W/2)；

H_out＝Eyebox_H+2ERF×tan(FOV_H/2)；

Wherein, Eyebox_WEye box width of eye movement_HHeight of eye movement range, ERF pupil distance, FOV_WIs the width of the field of view, FOV_HIs the height of the field of view region.

During implementation, when the emergent azimuth angle of emergent light coupled into the grating is determined according to the incident azimuth angle and the incident diffraction angle of incident light coupled into the grating, the period of the coupled grating and the wavelength of the incident light, the wave vector formula of the incident light is determined according to the structure of the coupled grating and the wave vector diagram of the incident light, the wave vector formula of the emergent light after the incident light passes through the coupled grating is determined according to the wave vector formula of the incident light and the refractive index of the optical waveguide plate, the emergent azimuth angle is determined according to the wave vector formula of the emergent light, and the emergent diffraction angle can also be determined. The formula is as follows:

wherein, when the width and height of the coupling-in grating are determined according to the width and height of the coupling-out grating, the diffraction angle and azimuth angle, the preset interval and the target parameter, the width W of the coupling-in grating can be determined according to the following formula_inAnd height H_in：

Moreover, although exemplary embodiments have been described herein, the scope thereof includes any and all embodiments based on the disclosure with equivalent elements, modifications, omissions, combinations (e.g., of various embodiments across), adaptations or alterations. The elements of the claims are to be interpreted broadly based on the language employed in the claims and not limited to examples described in the present specification or during the prosecution of the application, which examples are to be construed as non-exclusive. It is intended, therefore, that the specification and examples be considered as exemplary only, with a true scope and spirit being indicated by the following claims and their full scope of equivalents.

The above description is intended to be illustrative and not restrictive. For example, the above-described examples (or one or more versions thereof) may be used in combination with each other. For example, other embodiments may be used by those of ordinary skill in the art upon reading the above description. In addition, in the foregoing detailed description, various features may be grouped together to streamline the disclosure. This should not be interpreted as an intention that a disclosed feature not claimed is essential to any claim. Rather, the subject matter of the present disclosure may lie in less than all features of a particular disclosed embodiment. Thus, the following claims are hereby incorporated into the detailed description as examples or embodiments, with each claim standing on its own as a separate embodiment, and it is contemplated that these embodiments may be combined with each other in various combinations or permutations. The scope of the disclosure should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

While the present disclosure has been described in detail with reference to the embodiments, the present disclosure is not limited to the specific embodiments, and those skilled in the art can make various modifications and alterations based on the concept of the present disclosure, and the modifications and alterations should fall within the scope of the present disclosure as claimed.