Binocular display optical waveguide system and near-to-eye display equipment

Abstract

The invention discloses a binocular display optical waveguide system and near-to-eye display equipment. The binocular display optical waveguide system comprises a waveguide substrate, a coupling-in grating, a first conduction grating, a second conduction grating, a first coupling-out grating and a second coupling-out grating, the coupling-out grating is arranged on the waveguide substrate, the first conduction grating and the second conduction grating are both arranged on the waveguide substrate, and the first conduction grating and the second conduction grating are symmetrically arranged on the two sides of the coupling-in grating; the first out-coupling grating and the second out-coupling grating are both arranged on the waveguide substrate, and the first out-coupling grating and the second out-coupling grating are symmetrically arranged on the two sides of the in-coupling grating. The angle range of the direction angle coupled into the grating is-15 degrees to 15 degrees. Compared with the prior art, binocular image synchronous display of a single optical machine image source can be realized, the structural complexity of an optical waveguide system can be reduced, the weight and cost of near-eye display equipment are reduced, the power consumption of the near-eye display equipment is reduced, and meanwhile, the impression experience of a user is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical technology, in particular to a binocular display optical waveguide system and a near-eye display device. BACKGROUND

[0002] In the existing binocular display system, each binocular is usually configured with an independent optical engine module to image respectively to achieve the effect of stereoscopic vision. However, the use of a binocular independent optical engine way has relatively low integration of the near-eye display device, increases the cost and weight of the near-eye display device, and relatively significantly increases the power consumption of the near-eye display device, thereby affecting the user's experience. At the same time, the use of a double optical engine also increases the assembly difficulty of the optical waveguide system, affecting the production efficiency of the near-eye display device.

[0003] In view of this, it is necessary to provide a binocular display optical waveguide system and a near-eye display device to solve the above problems. SUMMARY

[0004] In view of the deficiencies in the prior art, the present application provides a binocular display optical waveguide system and a near-eye display device, which can realize the binocular image synchronous display function of a single optical engine image source, reduce the weight and volume of the near-eye display device, improve the endurance of the near-eye display device, improve the user's experience, and improve the production efficiency of the near-eye display device.

[0005] To achieve the above purpose, the first aspect of the present application provides a binocular display optical waveguide system, comprising a waveguide substrate, a coupling-in grating, a first transmission grating, a second transmission grating, a first coupling-out grating and a second coupling-out grating; the coupling-out grating is arranged on the waveguide substrate, the first transmission grating and the second transmission grating are both arranged on the waveguide substrate, and the first transmission grating and the second transmission grating are symmetrically arranged on both sides of the coupling-in grating; the first coupling-out grating and the second coupling-out grating are both arranged on the waveguide substrate, and the first coupling-out grating and the second coupling-out grating are symmetrically arranged on both sides of the coupling-in grating; the angle range of the direction angle of the coupling-in grating is -15° to 15°.

[0006] In a preferred embodiment, the direction angle of the coupling-in grating is 0°.

[0007] In a preferred embodiment, the coupling-in grating is arranged on the central axis of the horizontal line of the plane where the waveguide substrate is located.

[0008] In a preferred embodiment, the waveguide substrate includes a first surface close to the user's eye, the coupling-in grating is arranged on the first surface, and the coupling-in grating is a transmissive grating.

[0009] In a preferred embodiment, the waveguide substrate includes a second surface away from the user's eye, the coupling-in grating is arranged on the second surface, and the coupling-in grating is a reflective grating.

[0010] In a preferred embodiment, the distance between the first out-coupling grating and the second out-coupling grating ranges from 60 mm to 73 mm.

[0011] In a preferred embodiment, the horizontal line direction of the waveguide substrate is the x-axis, the grating vectors of the in-coupling gratings include a first grating vector K1 and a second grating vector K2, the grating vector of the first transmission grating is K3, the grating vector of the second transmission grating is K4, the grating vector of the first out-coupling grating is K5, the grating vector of the second out-coupling grating is K6, and the following conditions are met: the modulus of the resultant vector of K1, K3 and K5 is equal to one quarter of the x-axis component of the K-space projection of the incident light; and the modulus of the resultant vector of K2, K4 and K5 is equal to one quarter of the x-axis component of the K-space projection of the incident light.

[0012] In a preferred embodiment, the K-space includes a fifth region corresponding to the first out-coupling grating and a sixth region corresponding to the second out-coupling grating, and the fifth region and the sixth region are arranged side by side.

[0013] In a preferred embodiment, the K-space includes a fifth region corresponding to the first out-coupling grating and a sixth region corresponding to the second out-coupling grating, and the fifth region and the sixth region are arranged side by side.

[0014] The second aspect of the present application provides a near-eye display device including the binocular display optical waveguide system of any one of the preceding embodiments.

[0015] The present application has the beneficial effects that: by setting the in-coupling grating, adjusting the diffraction curve of the in-coupling grating, the incident light beam of a single optical machine can be separated into two light rays with opposite propagation directions and diffraction orders, to realize the binocular image synchronous display function of a single optical machine image source, reduce the structural complexity of the optical waveguide system, reduce the weight and cost of the near-eye display device, reduce the power consumption of the near-eye display device, and improve the user's viewing experience. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 The structure diagram of the binocular display optical waveguide system provided by the embodiment of the present application.

[0017] Figure 2 The first schematic diagram of the light wave vector distribution of the K-space when the binocular display optical waveguide system guides light.

[0018] Figure 3 The second schematic diagram of the light wave vector distribution of the K-space when the binocular display optical waveguide system guides light.

[0019] Figure 4 The third schematic diagram of the light wave vector distribution of the K-space when the binocular display optical waveguide system guides light. DETAILED DESCRIPTION

[0020] In the present application, the terms "provided with", "provided", "connected" should be interpreted in a broad manner. For example, it can be fixed connection, detachable connection, or integral structure; it can be mechanical connection, or electrical connection; it can be direct connection, or indirect connection through intermediate medium, or internal communication between two devices, elements or components. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0021] The terms "first", "second" are only for descriptive purpose, and cannot be understood as indicating or implying relative importance, or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise explicitly and specifically limited.

[0022] In addition, in addition to being used to represent the orientation or positional relationship, the above-mentioned part of the terms can also be used to represent other meanings, for example, the term "upper" can also be used to represent a certain dependent relationship or connection relationship in some cases. For those skilled in the art, the specific meaning of these terms in the present application can be understood according to the specific circumstances.

[0023] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application, and are not used to limit the present application.

[0024] The following is the content of the first aspect of the present application: Please refer to Figure 1 The embodiment provides a binocular display optical waveguide system, which comprises a waveguide substrate 1, an in-coupling grating 2, a first transmission grating 3, a second transmission grating 4, a first out-coupling grating 5 and a second out-coupling grating 6; the out-coupling grating is arranged on the waveguide substrate 1, the first transmission grating 3 and the second transmission grating 4 are both arranged on the waveguide substrate 1, and the first transmission grating 3 and the second transmission grating 4 are symmetrically arranged on the two sides of the in-coupling grating 2; the first out-coupling grating 5 and the second out-coupling grating 6 are both arranged on the waveguide substrate 1, and the first out-coupling grating 5 and the second out-coupling grating 6 are symmetrically arranged on the two sides of the in-coupling grating 2; the angle range of the direction angle of the in-coupling grating 2 is-15° to 15°.

[0025] The coordinate system is established on the plane of the waveguide substrate 1, with the plane of the waveguide substrate 1 as the xy coordinate plane and the thickness direction of the waveguide substrate 1 as the z-axis direction. The in-coupling grating 2 is used to separate the light emitted by the image source into first light and second light, and to efficiently in-couple the first light and the second light into the waveguide substrate 1. The first transmission grating 3 is used to receive the first light transmitted by the in-coupling grating 2 and to transmit the light to the first out-coupling grating 5. The second diffraction grating is used to receive the second light transmitted by the in-coupling grating 2 and to transmit the light to the second out-coupling grating 6. The first out-coupling grating 5 is used to out-couple the received light from the waveguide substrate 1 and project it into the eye of one of the users. The second out-coupling grating 6 is used to out-couple the received light from the waveguide substrate 1 and project it into the eye of the other of the users.

[0026] Specifically, the waveguide substrate 1 includes a first surface close to the user's eye and a second surface away from the user's eye. The in-coupling grating 2 can be disposed on the first surface or the second surface. When the in-coupling grating 2 is disposed on the first surface, the in-coupling grating 2 is a transmission grating. When the in-coupling grating 2 is disposed on the second surface, the in-coupling grating 2 is a reflection grating.

[0027] When the incident light beam is within a specific field of view angle range of -30° to 30°, the incident light beam is separated into +1 order and -1 order diffracted light after passing through the in-coupling grating 2. The +1 order diffracted light has a relatively high diffraction efficiency in the field of view range of -30° to 0°, and a relatively low diffraction efficiency in the field of view range of 0° to 30°. Correspondingly, the -1 order diffracted light has a relatively high diffraction efficiency in the field of view range of 0° to 30°, and a relatively low diffraction efficiency in the field of view range of -30° to 0°.

[0028] When the incident light beam is within a specific field of view angle range of -30° to 30°, the incident light beam is separated into +1 order and -1 order diffracted light after passing through the in-coupling grating 2. The +1 order diffracted light has a relatively high diffraction efficiency in the field of view range of -30° to 0°, and a relatively low diffraction efficiency in the field of view range of 0° to 30°. Correspondingly, the -1 order diffracted light has a relatively high diffraction efficiency in the field of view range of 0° to 30°, and a relatively low diffraction efficiency in the field of view range of -30° to 0°.

[0029] The orientation angle of the coupling grating 2 directly affects the propagation paths of the +1st order diffracted rays and the -1st order diffracted rays, which in turn affects the layout and size of the first conductive grating 3 and the second conductive grating 4 in the binocular display waveguide system. By limiting the orientation angle of the coupling grating 2 to the range of -15° to 15°, the size of the waveguide substrate 1 and the binocular display waveguide system can be better ensured, and the first conductive grating 3 and the second conductive grating 4 can always be located within the effective area.

[0030] Understandably, by setting the coupling grating 2 and adjusting its diffraction curve, the incident beam of a single optical engine can be separated into two rays with opposite propagation directions and diffraction orders, thereby realizing the binocular image synchronous display function of a single optical engine image source. This can reduce the structural complexity of the optical waveguide system, reduce the weight and cost of near-eye display devices, reduce the power consumption of near-eye display devices, and improve the user's viewing experience.

[0031] Furthermore, in a preferred embodiment, the orientation angle of the coupling grating 2 is 0°. Specifically, a 0° orientation angle for the coupling grating 2 means that the grating fringes of the coupling grating 2 are parallel to the y-axis of the coordinate system established on the waveguide substrate 1. When the orientation angle of the coupling grating 2 is 0°, after the incident beam is separated into a first ray and a second ray by the coupling grating 2, the first ray and the second ray propagate in opposite horizontal directions. The first guiding grating 3 and the second guiding grating 4 can be better symmetrically arranged on both sides of the coupling grating 2, thereby forming a more reasonable and compact optical waveguide structure.

[0032] Furthermore, in one embodiment, the coupling grating 2 is disposed on the central axis of the horizontal line of the plane on which the waveguide substrate 1 is located. It can be understood that by disposing the coupling grating 2 on the central axis of the horizontal line, the coupling grating 2 can be positioned centrally on the waveguide substrate 1, which can better realize the layout of the first conducting grating 3, the second conducting grating 4, the first coupling grating 5 and the second coupling grating 6, and can reduce the volume of the binocular display optical waveguide system to a certain extent.

[0033] Furthermore, in one embodiment, the distance between the first coupling grating 5 and the second coupling grating 6 ranges from 60 mm to 73 mm. Preferably, the distance between the first coupling grating 5 and the second coupling grating 6 is 65 mm. It is understood that controlling the distance between the first coupling grating 5 and the second coupling grating 6 to 60 mm to 73 mm, while conforming to the common range of human interpupillary distance, can better constrain the size of the first coupling grating 5 and the second coupling grating 6, thereby better limiting the overall volume of the binocular display waveguide system.

[0034] For further details, please refer to... Figure 2In one embodiment, the horizontal direction of the waveguide substrate 1 is the x-axis. The grating vector of the coupled grating 2 includes a first grating vector K1 and a second grating vector K2. The grating vector of the first guiding grating 3 is K3, the grating vector of the second guiding grating 4 is K4, the grating vector of the first coupled grating 5 is K5, and the grating vector of the second coupled grating 6 is K6. The following conditions are met: the magnitude of the resultant vector of K1, K3, and K5 is equal to one-quarter of the component of the incident light projected in K space along the x-axis; the magnitude of the resultant vector of K2, K4, and K5 is equal to one-quarter of the component of the incident light projected in K space along the x-axis.

[0035] The grating vector is used to represent the control effect of each grating on the light wave vector. In K space, the control effect of the grating on the light wave vector is manifested as shifting the projection distribution of the light wave vector in K space along a specific direction by a vector K, and K=Gmλ / d (where G is the unit vector of the periodic direction of the grating, m is the diffraction secondary, λ is the wavelength of light in vacuum, and d is the grating period).

[0036] Specifically, the wave vector distribution of the incident light in K-space includes a first region S1 and a second region S2. The first region S1 corresponds to the +1st order diffracted light with a field of view ranging from -30° to 0°, and this light moves to the third region S3 through the first grating vector K1. The second region S2 corresponds to the -1st order diffracted light with a field of view ranging from 0° to 30°, and this light moves to the fourth region S4 through the second grating vector K2.

[0037] The grating vector of the first guiding grating 3 is K3. When light enters the first guiding grating 3, the beam will be deflected and then propagate to the first coupling grating 5. At this time, the region of light wave vector distribution in K space after moving through the first guiding grating 3 is the fifth region S5. The grating vector of the first coupling grating 5 is K5. When light enters the first coupling grating 5, the beam can couple out of the waveguide substrate 1 and enter the user's eye. At this time, the region of light wave vector distribution in K space after moving through the first coupling grating 5 is the target region S7 jointly formed by the first region S1 and the second region S2.

[0038] The grating vector of the second guiding grating 4 is K4. When light enters the second guiding grating 4, the beam will be deflected and then propagate to the second coupling grating 6. At this time, the region of light wave vector distribution in K space after moving through the second guiding grating 4 is the sixth region S6. The grating vector of the second coupling grating 6 is K6. When light enters the second coupling grating 6, the beam can be coupled out of the waveguide substrate 1 and enter the user's other eye. At this time, the region of light wave vector distribution in K space after moving through the second coupling grating 6 is the target region S7.

[0039] Furthermore, in a preferred embodiment, please refer to... Figure 2 and Figure 3The K-space includes a fifth region corresponding to the first coupling grating 5 and a sixth region corresponding to the second coupling grating 6, with the fifth and sixth regions arranged side by side. Specifically, as shown... Figure 2 and Figure 3 As shown, the +1st order diffracted ray and the -1st order diffracted ray can be incident on the boundary line where the fifth region and the sixth region coincide.

[0040] Furthermore, in a preferred embodiment, please refer to... Figure 4 The K-space includes a fifth region corresponding to the first coupling grating 5 and a sixth region corresponding to the second coupling grating 6, with the fifth and sixth regions overlapping. Specifically, the +1st order diffracted ray and the -1st order diffracted ray can be incident on the boundary lines on both sides of the overlapping area of ​​the fifth and sixth regions, respectively.

[0041] It is understandable that by adjusting and / or optimizing the configuration of the grating vector of the coupled grating, it can be ensured that the center of the projection area of ​​the final coupled beam in K space coincides with the origin, thereby ensuring that the field of view of the beam received by the user's left and right eyes is completely consistent, and realizing the binocular image display function of a single optomechanical image source.

[0042] In summary, by setting a coupling grating 2 and adjusting its diffraction curve, this application can separate the incident beam of a single optical engine into two rays with opposite propagation directions and diffraction orders, thereby realizing the binocular image synchronous display function of a single optical engine image source. This can reduce the structural complexity of the optical waveguide system, reduce the weight and cost of near-eye display devices, reduce the power consumption of near-eye display devices, and improve the user's viewing experience.

[0043] The second aspect of this application provides a near-eye display device, which includes the binocular display optical waveguide system of any of the foregoing embodiments. It is understood that by setting up a binocular display optical waveguide system, the function of synchronous display of binocular images from a single optomechanical image source can be realized, reducing the structural complexity of the optical waveguide system, reducing the weight and cost of the near-eye display device, reducing the power consumption of the near-eye display device, and improving the user's viewing experience.

[0044] The above are merely specific embodiments of this application. It should be noted that those skilled in the art can make several improvements and modifications without departing from the principles of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A binocular display optical waveguide system, characterized in that, The device includes a waveguide substrate, a coupling grating, a first conductive grating, a second conductive grating, a first coupling grating, and a second coupling grating. The coupling grating is disposed on the waveguide substrate. The first and second conductive gratings are both disposed on the waveguide substrate and are symmetrically disposed on both sides of the coupling grating. The first and second coupling gratings are both disposed on the waveguide substrate and are symmetrically disposed on both sides of the coupling grating. The orientation angle of the coupling grating has a range of -15° to 15°.

2. The binocular display optical waveguide system according to claim 1, characterized in that, The orientation angle of the coupled grating is 0°.

3. The binocular display optical waveguide system according to claim 1, characterized in that, The coupling grating is positioned on the central axis of the horizontal line of the plane containing the waveguide substrate.

4. The binocular display optical waveguide system according to claim 1, characterized in that, The waveguide substrate includes a first surface close to the user's eye, and the coupling grating is disposed on the first surface. The coupling grating is a transmission grating.

5. The binocular display optical waveguide system according to claim 1, characterized in that, The waveguide substrate includes a second surface away from the user's eye, and the coupling grating is disposed on the second surface. The coupling grating is a reflective grating.

6. The binocular display optical waveguide system according to claim 1, characterized in that, The distance between the first coupling grating and the second coupling grating ranges from 60 mm to 73 mm.

7. The binocular display optical waveguide system according to claim 1, characterized in that, The horizontal direction of the waveguide substrate is the x-axis. The grating vector of the coupled grating includes a first grating vector K1 and a second grating vector K2. The grating vector of the first conductive grating is K3, the grating vector of the second conductive grating is K4, the grating vector of the first coupled grating is K5, and the grating vector of the second coupled grating is K6. The resultant vector of K1, K3, and K5 has a modulus equal to one-quarter of the x-axis component of the incident light projected in K space. The magnitude of the resultant vector of K2, K4 and K5 is equal to one-quarter of the x-axis component of the incident light projected onto space K.

8. The binocular display optical waveguide system according to claim 7, characterized in that, The K-space includes a fifth region corresponding to the first coupling grating and a sixth region corresponding to the second coupling grating, with the fifth region and the sixth region arranged side by side.

9. The binocular display optical waveguide system according to claim 7, characterized in that, The K-space includes a fifth region corresponding to the first coupling grating and a sixth region corresponding to the second coupling grating, wherein the fifth region and the sixth region are arranged to overlap.

10. A near-eye display device, characterized in that, The binocular display optical waveguide system includes any one of claims 1 to 9.

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