AR glasses

Abstract

The invention discloses AR glasses. The AR glasses comprise an optical machine, a first prism, a second prism and a waveguide, the first prism and the second prism are sequentially arranged along the light emitting direction of the ray machine, the waveguides comprise a first waveguide and a second waveguide which are respectively arranged along the reflection directions of the first prism and the second prism, the first waveguide is provided with a first coupling-in area and a first coupling-out area, and the second waveguide is provided with a second coupling-in area and a second coupling-out area; wherein the first prism is used for reflecting and transmitting light rays emitted by the ray machine to form first light rays and second light rays, the first light rays enter the first coupling-in area, and the second prism is used for reflecting the second light rays and entering the second coupling-in area; and the first light and the second light are subjected to total reflection propagation in the first waveguide and the second waveguide respectively and finally reach the first coupling-out area and the second coupling-out area, so that an image is formed. The waveguide structure is high in light efficiency, clear and complete in image display and not prone to being polluted and damaged, and the user experience is improved.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and in particular to AR glasses. Background Art

[0002] Augmented reality (AR) technology is a technology that combines virtual information with real scenes to bring an immersive experience to users. The core of AR technology lies in the use of computer vision algorithms, sensor technology, and real-time data processing capabilities. In specific implementation, the near-eye display system of AR technology converts pixels on the display into distant virtual images through a series of optical imaging elements and accurately projects them to the human eye. This process is usually presented to users through terminals such as head-mounted display devices, AR glasses, or smartphone screens, blurring the boundaries between virtual and reality and creating a seamless new environment.

[0003] However, in the published patent (application number 202110653697.2), the application name is a waveguide assembly and a folding AR eyepiece with an optical front, such as Figure 1 As shown, the waveguide plate assembly includes a left waveguide plate and a right waveguide plate that are connected to each other. With the connection as the center, the structures of the left waveguide plate and the right waveguide plate are mirror-symmetrical and form an angle. A folding structure is adopted to make the waveguide plates parallel to each other fold inward at the joint, so that the outer edge of the lens is close to the face, thereby improving the wearing aesthetics. Despite this, the design still has the following problems: on the one hand, the optical machine 10 needs to be close to the waveguide. If there is a certain distance from it, the light spot is too large, which will cause the light spot to not be fully irradiated into the pupil area, and then the monocular image display will be incomplete; on the other hand, the waveguide 20 designed in this patent needs to be cut grating operation, which not only reduces the light efficiency, but also easily produces edge stray light problems. At the same time, the exposed grating is also easily contaminated and damaged, thereby reducing the reliability of the product.

[0004] At the same time, the optical machine of AR glasses usually includes LCOS, DLP, Micro-LED, etc. Micro LED is small in size, but the color display effect of Micro LED is not good at present, while the color display effect of DLP or LCOS optical machine is better, but because the optical machine 230 is large in size, it needs to be placed horizontally to reduce the impact of the volume. At this time, a prism 40 (such as a reflective prism) or a reflector is needed to turn the light path. Its general structure is as follows Figure 2 As shown, Figure 1 Comparison of the schemes in Figure 2 The optical path before the middle entrance pupil becomes longer, and this situation will cause the gratings of the two coupling areas (coupling area 1 501 and coupling area 2 502) on waveguide 2 50 to have a large difference in coupling energy to light at the same angle, thereby causing brightness differences between the left and right eyes. Summary of the invention

[0005] The purpose of the present invention is to provide an AR glasses, aiming to solve the problems in the prior art that the optical machine needs to be close to the waveguide, the waveguide needs to cut the grating, and there is a brightness difference between the left and right eyes.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0007] The present invention provides an AR glasses, comprising:

[0008] An optical machine, a first prism, a second prism and a waveguide; the first prism and the second prism are sequentially arranged along the light emitting direction of the optical machine, the waveguide comprises a first waveguide and a second waveguide respectively arranged along the reflection directions of the first prism and the second prism, the first waveguide is provided with a first coupling-in region and a first coupling-out region, and the second waveguide is provided with a second coupling-in region and a second coupling-out region;

[0009] The first prism is used to reflect and transmit the light emitted by the optical machine to form a first light and a second light. The first light enters the first coupling-in area, and the second prism is used to reflect the second light and enter the second coupling-in area. The first light and the second light are respectively totally reflected and propagated inside the first waveguide and the second waveguide, and finally reach the first coupling-out area and the second coupling-out area, thereby forming an image.

[0010] Optionally, an angle is set between the first waveguide and the second waveguide.

[0011] Optionally, the first prism is a polarizing beam splitter or a non-polarizing beam splitter.

[0012] Optionally, the first prism is a polarization beam splitter, and the AR glasses further include a wave plate, and the wave plate is arranged between the first prism and the first waveguide; or, the wave plate is arranged between the second prism and the second waveguide.

[0013] Optionally, the first prism includes a polarization beam splitter and a wave plate, and the wave plate is arranged along the reflection direction of the polarization beam splitter.

[0014] Optionally, the wave plate is a 1 / 2 wave plate.

[0015] Optionally, the second prism is a reflecting prism.

[0016] Optionally, a first liquid crystal shutter and a second liquid crystal shutter are further included, wherein the first liquid crystal shutter is arranged between the first prism and the first waveguide, and the second liquid crystal shutter is arranged between the second prism and the second waveguide.

[0017] Optionally, the first coupling region and the second coupling region are provided with gratings, and the gratings include slanted gratings or blazed gratings.

[0018] Optionally, pupil expansion areas are provided on both the first waveguide and the second waveguide.

[0019] The present invention provides an AR glasses. In an embodiment of the present invention, a first prism and a second prism are sequentially arranged in a light-emitting direction of an optical machine, thereby leading out a first light ray and a second light ray. A first coupling-in region and a second coupling-in region are arranged relatively to each other, and the first coupling-out region and the second coupling-out region correspond to the first coupling-in region and the second coupling-in region, respectively, so that the optical machine can ensure the integrity of monocular imaging without being particularly close to a waveguide structure; and the waveguide does not need to cut a grating, but two independent entrance pupil regions are respectively arranged in the first waveguide and the second waveguide, which can not only prevent the grating from being polluted by impurities such as external water vapor, but also reduce the possibility of edge stray light; at the same time, the grating will not be exposed to the outside, so that the grating is protected from pollution and damage by the external environment, the reliability of the product is improved, and the user experience is further enhanced; in addition, two first prisms and a second prism are arranged, which are equivalent to two sub-light sources and correspond to two coupling-in regions, so as to reduce the brightness difference between the left and right eyes, so that the displayed image is complete. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0021] Figure 1 A schematic diagram of the structure of an optical waveguide provided by the prior art;

[0022] Figure 2 A schematic diagram of the structure of another optical waveguide provided by the prior art;

[0023] Figure 3 A schematic diagram of the structure of AR glasses provided by an embodiment of the present invention;

[0024] Figure 4 A schematic diagram of light propagating in a first waveguide and a second waveguide provided in an embodiment of the present invention;

[0025] Figure 5 Another structural schematic diagram of the AR glasses provided by an embodiment of the present invention;

[0026] Figure 6 Another structural schematic diagram of the AR glasses provided by an embodiment of the present invention.

[0027] Description of the symbols in the figure:

[0028] In the prior art, 10, optical machine 1; 20, waveguide 1; 30, optical machine 2; 40, prism; 50, waveguide 2; 501, coupling region 1; 502, coupling region 2;

[0029] 100, optical machine; 200, first prism; 300, second prism; 400, waveguide; 401, first waveguide; 4011, first coupling-in region; 4012, first decoupling region; 402, second waveguide; 4021, second coupling-in region; 4022, second decoupling region; 500, first light; 600, second light; 700, wave plate; 800, first liquid crystal shutter; 900, second liquid crystal shutter. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0032] It should also be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0033] It should be further understood that the term "and / or" used in the present description and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0034] See also Figure 3 and Figure 4The embodiment of the present invention provides an AR glasses, including: an optical machine 100, a first prism 200, a second prism 300 and a waveguide 400; the first prism 200 and the second prism 300 are sequentially arranged along the light emitting direction of the optical machine 100, the waveguide 400 includes a first waveguide 401 and a second waveguide 402 respectively arranged along the reflection directions of the first prism 200 and the second prism 300, the first waveguide 401 is provided with a first coupling-in region 4011 and a first coupling-out region 4012, the second waveguide 402 is provided with a second coupling-in region 4021 and a second coupling-out region 4022. Area 4022; wherein the first prism 200 is used to form a first light 500 and a second light 600 by reflection and transmission respectively from the light emitted by the optical machine 100, the first light 500 enters the first coupling-in area 4011, and the second prism 300 is used to reflect the second light 600 and enter the second coupling-in area 4021; the first light 500 and the second light 600 are propagated by total reflection inside the first waveguide 401 and the second waveguide 402 respectively, and finally arrive at the first coupling-out area 4012 and the second coupling-out area 4022, thereby forming an image.

[0035] In this embodiment, the first prism 200 and the second prism 300 are sequentially arranged in the light-emitting direction of the optical machine 100, thereby leading out the first light 500 and the second light 600, the first coupling region 4011 and the second coupling region 4021 are arranged close to each other, and the first coupling region 4012 and the second coupling region 4022 correspond to the first coupling region 4011 and the second coupling region 4021 respectively, so that the optical machine 100 can ensure the integrity of the monocular imaging without being particularly close to the waveguide structure; and the waveguide 400 does not need to cut the grating, but two independent entrance pupil regions are respectively arranged in the first waveguide 401 and the second waveguide 402, which can not only prevent the external impurities such as water vapor from polluting the grating, but also reduce the possibility of edge stray light; at the same time, the grating will not be exposed to the outside, so as to protect the grating from pollution and damage by the external environment, improve the reliability of the product, and further enhance the user experience; in addition, two first prisms and second prisms are arranged, which are equivalent to two sub-light sources, corresponding to two coupling regions, thereby reducing the brightness difference between the left and right eyes, so that the displayed image is complete.

[0036] Further, such as Figure 4 As shown, an angle is set between the first waveguide 401 and the second waveguide 402. In this embodiment, the waveguide 400 can be formed by splicing two pieces of the first waveguide 401 and the second waveguide 402 with the same material and symmetrical structure at a certain angle. The angle between the first waveguide 401 and the second waveguide 402 is set to θ, θ is fixed, and the direction of the angle is toward the human eye. Due to the introduction of the angle, the crosstalk phenomenon on both sides of the light wave during the transmission process is significantly reduced. At the same time, the optical machine 100 is placed on the outside, and the image is coupled into the waveguide plate perpendicular to the human eye in a transmission manner. According to the transmission principle, the exit pupil beam (such as Figure 4 As shown, the light rays emitted vertically from the first exit pupil area 4012 and the second exit pupil area 4022 to the human eye are in the same direction as the entrance pupil light beam (the first light beam 500 and the second light beam 600), so the exit pupil light beam will also be emitted vertically to the human eye, thereby avoiding the influence of the angle on the exit light beam.

[0037] In a specific embodiment, the first prism 200 is a polarizing beam splitter or a non-polarizing beam splitter. In this embodiment, the first prism 200 can be a polarizing beam splitter PBS or a non-polarizing beam splitter (that is, a common beam splitter BS). The polarizing beam splitter PBS can split the non-polarized light incident along the light-emitting direction of the optical machine 100 into two beams of perpendicular linear polarized light (P polarized light and S polarized light), wherein the P polarized light (whose vibration direction is parallel to the light-emitting direction) will be completely transmitted by the polarizing beam splitter PBS, and then the P polarized light will continue to propagate along its original direction, while the S polarized light will be reflected by the polarizing beam splitter PBS, and the emitting direction forms a certain angle with the propagation direction of the P polarized light. When the first prism 200 is a polarization beam splitter PBS, the light emitted by the optical machine 100 along the light-emitting direction passes through the first prism 200, which is a polarization beam splitter PBS. When passing through the first prism 200, the incident non-polarized light is divided into two linearly polarized light beams. The transmitted P polarized light enters the second prism 300 and is reflected at an angle of 30° to 60°. The S polarized light enters the first coupling region 4011 of the first waveguide 401, and the P polarized light enters the second coupling region 4021 of the second waveguide 402. The first prism 200 and the second prism 300 described above act as two sub-light sources, corresponding to the first coupling region 4011 and the second coupling region 4021, respectively. By adjusting the polarization ratio or setting an aperture, the brightness difference between the left and right eyes can be reduced, and the displayed image can be complete.

[0038] In one embodiment, if Figure 5 As shown, the first prism 200 is a polarization beam splitter, and the AR glasses further include a wave plate 700, which is disposed between the first prism 200 and the first waveguide 401; or, the wave plate is disposed between the second prism 300 and the second waveguide 402. In this embodiment, when the first prism 200 is a polarization beam splitter PBS, it can separate the incident non-polarized light into P-polarized light and S-polarized light. In this particular design, the first coupling region 4011 and the second coupling region 4021 can be designed to be most sensitive to light in the P polarization state, that is, P polarized light has the highest diffraction efficiency in these regions.

[0039] However, due to the characteristics of the polarization beam splitter PBS, the P polarized light will be completely transmitted, while the S polarized light will be reflected. If only the output light of the PBS (i.e., the P polarized light) is relied upon, the S polarized light will be wasted because the polarization state of this part of the light does not match the most sensitive state of the coupling region. Therefore, in order to maximize the efficiency of the diffracted light of the first waveguide 401 and the second waveguide 402, a wave plate 700 is disposed between the first prism 200 and the first waveguide 401, that is, below the first prism 200. The wave plate 700 can convert the S polarized light emitted from the first prism 200 into P polarized light, so that the first coupling region 4011 and the second coupling region 4021 both receive light of the P polarization state.

[0040] In this way, both the P-polarized light directly transmitted from the PBS and the P-polarized light (original S-polarized light) converted by the wave plate 700 can enter the first coupling region 4011 and the second coupling region 4021 with the highest diffraction efficiency. In this way, the energy of the optical machine 100 is maximized, so that more light can enter the waveguide efficiently, thereby improving the integrity and efficiency of image display.

[0041] It should be noted that if the coupling region is sensitive to the S polarization state, both light rays can be adjusted to the S polarization state. At this time, a wave plate 700 can be set between the second prism 300 and the second waveguide 402, that is, below the second prism 300, and the first prism 200 is still a polarization beam splitter PBS. The light emitted by the optical machine 100 along the light output direction passes through the first prism 200. When passing through the first prism 200, the incident non-polarized light is divided into two beams of linear polarized light, the P polarized light is transmitted, and the S polarized light is reflected. The reflected S polarized light directly enters the first coupling region 4011. After the transmitted P polarized light enters the second prism 300, it is reflected at an angle of 30° to 60°. At this time, the wave plate 700 can convert the P polarized light reflected from the second prism 300 into S polarized light, so that the first coupling region 4011 and the second coupling region 4021 both receive light in the S polarization state. Whether it is P polarized light or S polarized light, it can be converted into the most sensitive polarization state in the coupling region through the wave plate 700 or other optical elements. In this way, no matter what the original polarization state of the light is, it can be received and utilized by the waveguide with the highest efficiency, so that the optical machine can be close to the waveguide to display the image completely.

[0042] In another embodiment, the first prism 200 includes a polarization beam splitter and a wave plate, and the wave plate is arranged along the reflection direction of the polarization beam splitter. In this embodiment, the first prism 200 is a polarization beam splitter PBS and a wave plate, which splits the incident non-polarized light into two linear polarized lights of the same polarization state in different directions (transmission and reflection).

[0043] Specifically, the first coupling region 4011 and the second coupling region 4021 are designed to be most sensitive to light in the P polarization state, that is, the diffraction efficiency of light in the P polarization state is the highest. Therefore, in order to make the diffraction light efficiency of the first waveguide 401 and the second waveguide 402 the highest, a wave plate is arranged in the first prism 200. The wave plate can convert the S polarized light reflected from the first prism 200 into P polarization state light, so that the first coupling region 4011 and the second coupling region 4021 both receive the P polarization state, which can maximize the utilization of the energy of the optical machine 100.

[0044] In a specific embodiment, the wave plate 700 is a 1 / 2 wave plate. The working principle of the 1 / 2 wave plate is based on its special optical properties. Light is an electromagnetic wave with a vibration direction and a vibration mode. When light passes through the wave plate, the wave plate changes the vibration direction and vibration mode of the light. Specifically, when linearly polarized light passes through the 1 / 2 wave plate, the phase of one polarization component is delayed by half a wavelength (π radians) compared to the other polarization component, thereby changing the polarization state of the light.

[0045] In a specific embodiment, the second prism 300 is a reflecting prism. In this embodiment, the second prism 300 is a reflecting prism, which reflects the second light 600 transmitted from the first prism 200 into the second coupling region 4021 of the second waveguide 402, ensuring that the first light 500 and the second light 600 can be efficiently propagated in the first waveguide 401 and the second waveguide 402, and can also be fully utilized.

[0046] Further, such as Figure 6 As shown, the first liquid crystal shutter 800 and the second liquid crystal shutter 900 are also included. The first liquid crystal shutter 800 is arranged between the first prism 200 and the first waveguide 401, and the second liquid crystal shutter 900 is arranged between the second prism 300 and the second waveguide 402. In this embodiment, the liquid crystal shutter is an optical element that can control whether light passes through. The main function of the first liquid crystal shutter 800 and the second liquid crystal shutter 900 is to cooperate with the polarization beam splitter PBS and the 1 / 2 wave plate to perform timing control on the P polarized light and the S polarized light to achieve a 3D display effect and ensure visual transmittance.

[0047] Since the images corresponding to all polarization states are the same, no matter whether it is through P polarized light or S polarized light, a 3D effect cannot be formed. Only through a timing method can a 3D display effect be achieved, so that the left and right eyes see different images respectively (that is, the images in the first waveguide 401 and the second waveguide 402 are alternately presented to the left and right eyes). Therefore, the first prism 200 directly uses PBS+1 / 2 wave plate, or the first prism 200 directly uses PBS+1 / 2 wave plate to generate light of the same polarization state, and then controls the switch through the liquid crystal shutter, so that the P polarized light (whether it is directly transmitted through the PBS or converted by the 1 / 2 wave plate) can enter the first waveguide 401 and the second waveguide 402 respectively according to the timing.

[0048] Further, the first coupling region 4011 and the second coupling region 4021 are provided with gratings, and the gratings include a kind of slanted grating or blazed grating. In this embodiment, the first coupling region 4011 and the second coupling region 4021 are used to couple the light beam of the optical machine 100 into the waveguide plate, so that the light beam satisfies the condition of total reflection propagation in the first waveguide 401 and the second waveguide 402. The coupling region can be a reflector or a reflector array, a prism, an embossed grating, a volume holographic grating, etc. The grating is an optical element composed of a series of equidistant parallel lines, and it is a dispersion element that performs light splitting by using the diffraction and interference principles of light.

[0049] Furthermore, the first outcoupling region 4012 and the second outcoupling region 4022 may be arrayed semi-transparent and semi-reflective mirror arrays, relief gratings, and volume holographic gratings, etc. The outcoupling region is used to couple the light beam propagated by total reflection out of the first waveguide 401 and the second waveguide 402 and transmit it to the human eye.

[0050] Furthermore, pupil expansion areas are provided on both the first waveguide 401 and the second waveguide 402. In this embodiment, the number of pupil expansion areas provided on the first waveguide 401 and the second waveguide 402 is not limited, and different pupil expansion methods can be used according to different grating distributions to improve the applicability of the product and user experience. When pupil expansion areas are provided on both the first waveguide 401 and the second waveguide 402, it means that after the light enters the waveguide, it will be adjusted by the pupil expansion area to better adapt to the user's pupil distance, so as to ensure that the light can be accurately projected onto the user's retina, thereby presenting a clear image and further enhancing the optical performance and comfort of the AR glasses.

[0051] Furthermore, the first waveguide 401 and the second waveguide 402 are usually made of glass or resin, or other materials with good optical properties, good transparency, and high refractive index; the first waveguide 401 and the second waveguide 402 form a refractive index difference with the external environment (usually air), so that light within a certain angle range can be fully reflected and propagated inside the first waveguide 401 and the second waveguide 402. The refractive index of the materials commonly used to make AR glasses optical waveguides (including various types of glass and resin) ranges from 1.5 to 2.0.

[0052] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. An AR glasses, characterized in that: The optical machine comprises an optical machine, a first prism, a second prism and a waveguide; the first prism and the second prism are sequentially arranged along the light emitting direction of the optical machine, the waveguide comprises a first waveguide and a second waveguide respectively arranged along the reflection directions of the first prism and the second prism, the first waveguide is provided with a first coupling-in region and a first coupling-out region, and the second waveguide is provided with a second coupling-in region and a second coupling-out region; The first prism is used to reflect and transmit the light emitted by the optical machine to form a first light and a second light. The first light enters the first coupling-in area, and the second prism is used to reflect the second light and enter the second coupling-in area. The first light and the second light are respectively totally reflected and propagated inside the first waveguide and the second waveguide, and finally reach the first coupling-out area and the second coupling-out area, thereby forming an image.

2. The AR glasses according to claim 1, characterized in that: An angle is set between the first waveguide and the second waveguide.

3. The AR glasses according to claim 1, characterized in that: The first prism is a polarizing beam splitter or a non-polarizing beam splitter.

4. The AR glasses according to claim 3, characterized in that: The first prism is a polarization beam splitter, and the AR glasses further include a wave plate, which is arranged between the first prism and the first waveguide; or, the wave plate is arranged between the second prism and the second waveguide.

5. The AR glasses according to claim 1, characterized in that: The first prism includes a polarization beam splitter and a wave plate, and the wave plate is arranged along the reflection direction of the polarization beam splitter.

6. The AR glasses according to claim 4 or 5, characterized in that: The wave plate is a 1 / 2 wave plate.

7. The AR glasses according to claim 1, characterized in that: The second prism is a reflecting prism.

8. The AR glasses according to claim 1, characterized in that: It also includes a first liquid crystal shutter and a second liquid crystal shutter, wherein the first liquid crystal shutter is arranged between the first prism and the first waveguide, and the second liquid crystal shutter is arranged between the second prism and the second waveguide.

9. The AR glasses according to claim 1, characterized in that: The first coupling region and the second coupling region are provided with gratings, and the gratings include one of a slanted grating and a blazed grating.

10. The AR glasses according to claim 1, characterized in that: The first waveguide and the second waveguide are both provided with pupil expansion areas.

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