Augmented reality equipment display method based on diffraction grating waveguide

Abstract

The invention discloses an augmented reality equipment display method based on diffraction grating waveguide. The method comprises the following steps: synthesizing first light containing a virtual image and second light containing a live-action image of an external scene into image light; the image display outputs image light to the coupling-in grating; image light enters the first diffractive optical element, the first diffractive optical unit and the second diffractive optical element which are coupled out of the grating after being totally reflected in the waveguide substrate; the first diffractive optical element and the first diffractive optical unit enable image light to be expanded and conducted in the diffraction grating waveguide, and then the image light is transmitted to the second diffractive optical element; the second diffraction optical element diffracts the image light and finally couples the image light out of the diffraction grating waveguide, and the coupled image light enters human eyes. Therefore, more image light coupled out by the coupling-out grating can be concentrated on the observation side of the human eyes, the phenomenon that the diffraction grating waveguide leaks the image light is improved, and the utilization efficiency of the diffraction grating waveguide on the image light is improved.

Description

Technical Field

[0001] The present invention relates to the field of augmented reality technology, and in particular to an augmented reality device display method based on a diffraction grating waveguide. Background Art

[0002] Diffractive optical waveguide augmented reality display has the advantage of compact structure because it folds the optical path into the waveguide. As a near-eye display, it can be closer to the ideal glasses form including thin lenses. As a head-up display, it can also greatly reduce the structure size and save space. At the same time, due to the characteristics of the diffractive optical element itself, it has good transmittance to the external ambient light.

[0003] Based on this, technicians in this field urgently need to design an augmented reality device display method based on a diffraction grating waveguide to improve the phenomenon of image light leakage in the diffraction grating waveguide and improve the utilization efficiency of the image light in the diffraction grating waveguide. Summary of the invention

[0004] In view of the above-mentioned deficiencies, the technical problem to be solved by the present invention is: to provide an augmented reality device display method based on a diffraction grating waveguide, which can make the image light coupled out by the coupling grating more concentrated on the side observed by the human eye, improve the phenomenon of image light leakage in the diffraction grating waveguide, and improve the utilization efficiency of the image light by the diffraction grating waveguide.

[0005] In order to solve the above technical problems, the technical solution of the present invention is:

[0006] A display method for an augmented reality device based on a diffraction grating waveguide, the augmented reality device comprising an image display and a diffraction grating waveguide, the diffraction grating waveguide comprising a waveguide substrate, an in-coupling grating and an out-coupling grating arranged on the waveguide substrate, the out-coupling grating comprising a plurality of first diffractive optical elements and a plurality of second diffractive optical elements; all the first diffractive optical elements are arranged at intervals along a first direction, all the second diffractive optical elements are arranged at intervals along a second direction, and the first diffractive optical element intersects with the second diffractive optical element; the first diffractive optical element is provided with a plurality of first diffractive optical units at intervals along its length direction; the display method comprising:

[0007] Step 1: emitting a first light beam including a virtual image, wherein the virtual image is an image transmitted from an external device;

[0008] Step 2: obtaining a second light ray containing a real scene image of an external scene;

[0009] Step 3: synthesizing the image light by combining the first light including the virtual image and the second light including the real scene image of the external scene;

[0010] Step 4, the image display outputs image light to the coupling-in grating;

[0011] Step 5: the image light enters the first diffractive optical element, the first diffractive optical unit and the second diffractive optical element of the outcoupling grating after being totally reflected in the waveguide substrate;

[0012] Step 6: The first diffractive optical element and the first diffractive optical unit expand and transmit the image light in the diffraction grating waveguide, and then transmit it to the second diffractive optical element;

[0013] Step seven: the second diffractive optical element diffracts the image light, and finally couples out the diffraction grating waveguide, and the coupled image light enters the human eye.

[0014] Preferably, the diffraction efficiency of the first diffractive optical element and the first diffractive optical unit is greater than the diffraction efficiency of the second diffractive optical element.

[0015] Preferably, the diffraction grating waveguide comprises two outcoupling gratings, and the two outcoupling gratings are symmetrically arranged about a central axis of the incoupling grating.

[0016] Preferably, the augmented reality device is AR glasses.

[0017] Preferably, the acquired real-scene image is a real-scene image of the environment where the user is located; and the virtual image includes: a virtual display screen, a virtual mouse or a virtual keyboard.

[0018] After adopting the above technical solution, the beneficial effects of the present invention are:

[0019] The display method of the augmented reality device based on the diffraction grating waveguide of the present invention mainly emits a first light beam containing a virtual image, and the virtual image is an image transmitted from the received external device; obtains a second light beam containing a real scene image of an external scene; synthesizes the image light beam by combining the first light beam containing the virtual image with the second light beam containing the real scene image of the external scene; the image display outputs the image light beam to the coupling-in grating; the image light beam enters the first diffraction optical element, the first diffraction optical unit and the second diffraction optical element of the coupling-out grating after total reflection in the waveguide substrate; the first diffraction optical element and the first diffraction optical unit expand and conduct the image light beam in the diffraction grating waveguide, and then transmits it to the second diffraction optical element; the second diffraction optical element diffracts the image light beam, and finally couples out the diffraction grating waveguide, and the coupled-out image light beam enters the human eye. It can be seen that the display method of the present invention can make the image light beam coupled out of the coupling-out grating more concentrated on the side observed by the human eye, improve the phenomenon that the diffraction grating waveguide leaks the image light beam, and improve the utilization efficiency of the diffraction grating waveguide for the image light beam, and the display method of the present invention is simple and easy to implement. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail in the following embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0023] It should be particularly noted that: the augmented reality device involved in the present invention may be but is not limited to AR glasses, the AR glasses include an image display and a diffraction grating waveguide, wherein the diffraction grating waveguide includes a waveguide substrate, an in-coupling grating and an out-coupling grating arranged on the waveguide substrate, and the out-coupling grating includes a plurality of first diffractive optical elements and a plurality of second diffractive optical elements; all the first diffractive optical elements are arranged at intervals along a first direction, all the second diffractive optical elements are arranged at intervals along a second direction, and the first diffractive optical element intersects with the second diffractive optical element; the first diffractive optical element is provided with a plurality of first diffractive optical units at intervals along its own length direction;

[0024] The first diffractive optical unit includes a first diffractive optical structure and a second diffractive optical structure, the first diffractive optical structure and the second diffractive optical structure are arranged at intervals along the length direction of the first diffractive optical element, the length direction of the first diffractive optical structure forms a first predetermined angle with the length direction of the first diffractive optical element, and the length direction of the second diffractive optical structure forms a second predetermined angle with the length direction of the first diffractive optical element; the diffraction efficiency of the first diffractive optical element and the first diffractive optical unit is greater than the diffraction efficiency of the second diffractive optical element. The first diffractive optical unit also includes: a third diffractive optical structure, located between the first diffractive optical structure and the second diffractive optical structure, the length direction of the third diffractive optical structure is the same as the length direction of the first diffractive optical element. Furthermore, the diffraction grating waveguide includes two outcoupling gratings, and the two outcoupling gratings are symmetrically arranged about the central axis of the incoupling grating.

[0025] A display method for an augmented reality device based on a diffraction grating waveguide comprises the following steps:

[0026] Step 1: emit a first light beam containing a virtual image, where the virtual image is an image transmitted from an external device. In this embodiment, the real scene image obtained is a real scene image of the user's environment. The virtual image includes: a virtual display screen, a virtual mouse or a virtual keyboard.

[0027] Step 2: obtaining a second light ray containing a real scene image of an external scene;

[0028] Step 3: synthesizing the image light by combining the first light including the virtual image and the second light including the real scene image of the external scene;

[0029] Step 4, the image display outputs image light to the coupling-in grating;

[0030] Step 5: The image light enters the first diffractive optical element, the first diffractive optical unit and the second diffractive optical element of the outcoupling grating after total reflection in the waveguide substrate;

[0031] Step 6: The first diffractive optical element and the first diffractive optical unit expand and transmit the image light in the diffraction grating waveguide, and then transmit it to the second diffractive optical element;

[0032] Step seven: The second diffractive optical element diffracts the image light, and finally couples out the diffraction grating waveguide, and the coupled image light enters the human eye.

[0033] When the AR glasses using the display method of the present invention are working, the image display emits the synthesized image light, which first enters the diffraction grating waveguide through the coupling-in grating, and then is totally reflected by the waveguide substrate and enters the coupling-out grating. The image light entering the coupling-out grating is first diffracted by the first diffraction optical element, the first diffraction optical structure, the second diffraction optical structure, and the third diffraction optical structure for expansion and conduction, and then is diffracted by the second diffraction optical element and coupled out of the diffraction grating waveguide. The coupled-out image light enters the human eye, so that the human eye can see the image of the image display, achieving the enhanced display effect of the AR glasses.

[0034] It can be seen that by adopting the display method of the present invention, the image light coupled out by the outcoupling grating can be more concentrated on the side observed by the human eye, the phenomenon of image light leakage from the diffraction grating waveguide is improved, and the utilization efficiency of the image light by the diffraction grating waveguide is improved. Moreover, the display method of the present invention is simple and easy to implement.

[0035] In addition, the augmented reality display device of the present invention also includes a processor, a gyroscope, an accelerometer, a magnetic field meter, a monocular camera, a depth of field sensor or a binocular / multi-eye camera, and the processor is used to synthesize a first light beam containing a virtual image and a second light beam containing a real scene image of an external scene and display them in a first display mode; or the processor combines data from the gyroscope, accelerometer, magnetic field meter, monocular camera, depth of field sensor or binocular / multi-eye camera and displays them in a second display mode; or the processor combines data from the gyroscope, accelerometer or magnetic field meter and displays them in a third display mode; the first display mode is a display mode in which the relative angle and relative position between the virtual image and the real scene image are not fixed; the second display mode is a display mode in which the relative angle and relative position between the virtual image and the real scene image are fixed; the third mode is a display mode in which the relative angle between the virtual image and the real scene image is fixed, but the relative position is not fixed.

[0036] The above-described preferred embodiments of the present invention are only intended to limit the present invention. Any modifications made within the spirit and principles of the present invention, as well as improvements to the display method of an augmented reality device based on a diffraction grating waveguide, etc., should be included in the protection scope of the present invention.

Claims

1. A display method of an augmented reality device based on a diffraction grating waveguide, wherein the augmented reality device comprises an image display and a diffraction grating waveguide, wherein the diffraction grating waveguide comprises a waveguide substrate, an in-coupling grating and an out-coupling grating arranged on the waveguide substrate, wherein the out-coupling grating comprises a plurality of first diffractive optical elements and a plurality of second diffractive optical elements; all the first diffractive optical elements are arranged at intervals along a first direction, and all the second diffractive optical elements are arranged at intervals along a second direction, and the first diffractive optical elements intersect with the second diffractive optical elements; The first diffractive optical element is provided with a plurality of first diffractive optical units spaced apart along its length direction; characterized in that: The display method comprises: Step 1: emitting a first light beam including a virtual image, wherein the virtual image is an image transmitted from an external device; Step 2: obtaining a second light ray containing a real scene image of an external scene; Step 3: synthesizing the image light by combining the first light including the virtual image and the second light including the real scene image of the external scene; Step 4, the image display outputs image light to the coupling-in grating; Step 5: the image light enters the first diffractive optical element, the first diffractive optical unit and the second diffractive optical element of the outcoupling grating after being totally reflected in the waveguide substrate; Step 6: The first diffractive optical element and the first diffractive optical unit expand and transmit the image light in the diffraction grating waveguide, and then transmit it to the second diffractive optical element; Step seven: the second diffractive optical element diffracts the image light, and finally couples out the diffraction grating waveguide, and the coupled image light enters the human eye.

2. The augmented reality device display method based on diffraction grating waveguide according to claim 1, characterized in that: The diffraction efficiency of the first diffractive optical element and the first diffractive optical unit is greater than the diffraction efficiency of the second diffractive optical element.

3. The augmented reality device display method based on diffraction grating waveguide according to claim 1, characterized in that: The diffraction grating waveguide includes two outcoupling gratings, and the two outcoupling gratings are symmetrically arranged about the central axis of the incoupling grating.

4. The augmented reality device display method based on diffraction grating waveguide according to claim 1, characterized in that: The augmented reality device is AR glasses.

5. The augmented reality device display method based on diffraction grating waveguide according to claim 1, characterized in that: The acquired real scene image is a real scene image of the environment where the user is located; the virtual image includes: a virtual display screen, a virtual mouse or a virtual keyboard.