A single-lens machine binocular double-layer display system based on beam splitting right-angle turning prism

Abstract

The present invention provides a single optical machine binocular double-layer display system based on a beam splitting right-angle turning prism, comprising: an optical machine, used for providing a light beam with a preset field angle; a first optical waveguide layer, arranged on one side of the optical machine, a first coupling unit is arranged in the first optical waveguide layer, the first coupling unit is used for coupling the light beam output by the optical machine into the first optical waveguide layer; a second optical waveguide layer, arranged on a side of the first optical waveguide layer away from the optical machine, a second coupling unit is arranged in the second optical waveguide layer, the second coupling unit is used for coupling the light beam not coupled into the first optical waveguide layer into the first optical waveguide layer; wherein the first coupling unit and the second coupling unit are arranged in a staggered manner, a beam splitting right-angle turning prism is arranged between the optical machine and the first optical waveguide layer, the beam splitting right-angle turning prism comprises a long-wave pass filter film, the long-wave pass filter film is used for reflecting or transmitting light of a preset wavelength, and is used for reflecting the field angles of green light and blue light in the light beam to the second coupling unit, and reflecting the red light in the light beam to the first coupling unit. The present invention solves the problems of insufficient brightness, reduced brightness uniformity and color uniformity of the image coupled out of a single-light machine single-layer binocular waveguide in the prior art, and avoids the problem of crosstalk between double-layer waveguides.

Description

Technical Field

[0001] The present invention relates to the field of optical machine technology, and in particular to a single optical machine binocular double-layer display system based on a beam splitting right-angle turning prism. Background Art

[0002] The single-optical binocular waveguide can achieve binocular imaging while using one layer of waveguide and one optical machine, and naturally has the function of binocular fusion. It is superior to the dual-optical binocular waveguide in terms of cost and effect, and is currently a popular binocular reality solution in AR glasses or helmets.

[0003] The optical machine used in the current single-optical binocular waveguide is mainly a single green optical machine, with a central wavelength of about λ=530nm, a corresponding field of view angle DFOV=30°, and a waveguide refractive index n=1.6~1.9. The current wavelength and field of view limit the use scenarios of single-optical binocular waveguides, so that they can only be used for functions such as information prompts, translation, and map navigation.

[0004] In the prior art, a single-layer binocular waveguide of a single optical machine has the problem of missing one or two field of view angles under the condition of full-color optical machine incidence, resulting in insufficient brightness of the outcoupled image, reduced brightness uniformity, and color uniformity. When a double-layer waveguide is used, crosstalk is prone to occur between the double-layer waveguides. Summary of the invention

[0005] Based on this, the purpose of the present invention is to provide a single-light machine binocular double-layer display system based on a beam-splitting right-angle turning prism, which aims to solve the problem in the prior art that a single-light machine single-layer binocular eye waveguide has one or two missing field angles under full-color light machine incidence, resulting in insufficient brightness of the outcoupled image, reduced brightness uniformity, and color uniformity, and when a double-layer waveguide is used, crosstalk is likely to occur between the double-layer waveguides.

[0006] The embodiment of the present invention is implemented as follows:

[0007] On the one hand, the present invention provides a single-lens machine binocular double-layer display system based on a beam splitting right-angle turning prism, the system comprising:

[0008] An optical machine, for providing a light beam with a field of view of a preset angle;

[0009] A first optical waveguide layer, arranged at one side of the optical machine, wherein a first coupling unit is arranged in the first optical waveguide layer, and the first coupling unit is used to couple the light beam output by the optical machine into the first optical waveguide layer;

[0010] A second optical waveguide layer is arranged on a side of the first optical waveguide layer away from the optical engine, wherein a second coupling unit is arranged in the second optical waveguide layer, and the second coupling unit is used to couple the light beam that is not coupled into the first optical waveguide layer into the first optical waveguide layer;

[0011] Among them, the first coupling unit and the second coupling unit are arranged in a staggered manner, and a beam splitting right-angle turning prism is arranged between the optical machine and the first optical waveguide layer. The beam splitting right-angle turning prism includes a long-wave pass filter film, and the long-wave pass filter film is used to reflect or transmit light of a preset wavelength, and is used to reflect the field angles of green light and blue light in the light beam to the second coupling unit, and transmit the red light in the light beam and reflect it to the first coupling unit through the prism.

[0012] Furthermore, in the above-mentioned single-lens machine binocular dual-layer display system based on a beam splitting right-angle turning prism, the period of the first coupling unit is:

[0013] ;

[0014] in, is the central wavelength of the red light in the beam, n is the waveguide refractive index, 1 ≤M2≤1.2, 0.8 ≤N2≤1, is the horizontal field of view, is the vertical field of view.

[0015] Furthermore, in the above-mentioned single-lens machine binocular dual-layer display system based on a beam splitting right-angle turning prism, the period of the second coupling unit is:

[0016] ;

[0017] Where n is the waveguide refractive index, is the horizontal field of view, is the vertical field of view, is the central wavelength of the green light in the beam, is the central wavelength of the blue light in the beam.

[0018] Furthermore, in the above-mentioned single-light machine binocular dual-layer display system based on the beam-splitting right-angle turning prism, the centers of the first coupling unit and the second coupling unit correspond to the center positions of the first exit pupil and the second exit pupil of the beam-splitting right-angle turning prism respectively.

[0019] Furthermore, in the above-mentioned single-light machine binocular dual-layer display system based on the beam splitting right-angle turning prism, the thickness of the first optical waveguide layer and the second optical waveguide layer are both 0.3mm~1mm, and the refractive index is both 1.6~2.5.

[0020] Furthermore, in the above-mentioned single-light machine binocular dual-layer display system based on a beam splitting right-angle turning prism, the spacing between the first optical waveguide layer and the second optical waveguide layer is 0.03 mm to 0.08 mm.

[0021] Furthermore, in the above-mentioned single-optical machine binocular dual-layer display system based on a beam splitting right-angle turning prism, the first coupling unit and the second coupling unit are diffractive optical elements, and the diffractive optical elements are surface relief gratings or volume holographic gratings;

[0022] The surface relief grating is any one of a rectangular grating, a tilted grating and a blazed grating.

[0023] Furthermore, in the above-mentioned single-light machine binocular dual-layer display system based on a beam splitting right-angle turning prism, the first turning out-coupling unit and the second turning out-coupling unit of the first optical waveguide layer are respectively disposed on both sides of the first coupling-in unit, and the first turning out-coupling unit and the second turning out-coupling unit of the second optical waveguide layer are respectively disposed on both sides of the second coupling-in unit;

[0024] The first turning outcoupling unit and the second turning outcoupling unit of the first optical waveguide layer, and the first turning outcoupling unit and the second turning outcoupling unit of the second optical waveguide layer are two-dimensional gratings or consist of two one-dimensional gratings.

[0025] Furthermore, in the above-mentioned single-light machine binocular dual-layer display system based on a beam splitting right-angle turning prism, the period of the first coupling unit is 400nm~500nm, and the period of the second coupling unit is 300nm~400nm.

[0026] Furthermore, in the above-mentioned single-optical-machine binocular-double-layer display system based on the beam-splitting right-angle turning prism, the optical machine is any one of Micro-LEDs, LCOS, DLP and LBS.

[0027] The present invention provides two optical waveguide layers, respectively provides a first coupling unit and a second coupling unit in the two optical waveguide layers, and provides a beam splitting right-angle turning prism between the optical machine and the first optical waveguide layer. By providing a long-wave pass filter film on the beam splitting right-angle turning prism, light of a preset wavelength is reflected or transmitted, and all viewing angles of green light and blue light in the light beam are reflected to the second coupling unit, and all viewing angles of red light in the light beam are transmitted and reflected to the first coupling unit through the prism. The first and second coupling units are coupled to the first and second optical waveguides to achieve image outcoupling, ensuring that each color has a complete viewing angle, avoiding the lack of viewing angle, resulting in insufficient brightness of the coupled image, and reduced brightness uniformity and color uniformity. In addition, since the first coupling unit and the second coupling unit can be arranged in a staggered manner, crosstalk between the double-layer waveguides can be avoided at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A schematic diagram of the red, green and blue light field angle coupling of a single-light machine in the prior art;

[0029] Figure 2 A schematic diagram of the structure of a single-lens machine binocular dual-layer display system based on a beam splitting right-angle turning prism in one embodiment of the present invention;

[0030] Figure 3 A schematic diagram of the coupling of green light and blue light field angles of a single-lens machine binocular dual-layer display system based on a beam splitting right-angle turning prism in one embodiment of the present invention;

[0031] Figure 4 Schematic diagram of red light field angle coupling of a single-lens machine binocular dual-layer display system based on a beam splitting right-angle turning prism in one embodiment of the present invention.

[0032] The following specific implementation manner will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0033] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. Several embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0034] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0036] The current single-optical binocular waveguide can achieve binocular imaging while using one layer of waveguide and one optical machine, and naturally has the function of binocular fusion. It is superior to the dual-optical binocular waveguide in terms of cost and effect, and is currently a popular binocular reality solution in AR glasses or helmets.

[0037] In the current single-optical machine binocular waveguide implementation scheme, the optical machine used is mainly a single green optical machine, with a central wavelength of about λ=530nm, a corresponding field of view angle DFOV=30°, and a waveguide refractive index n=1.6~1.9; however, the current wavelength and field of view limit the use scenarios of single-optical machine binocular waveguide, so that it can only be used for functions such as information prompt translation and map navigation.

[0038] If based on the current waveguide refractive index, such as n=1.9, a full-color optical machine is used, DFOV=30°, λ=450nm~630nm, the optical waveguide will be monocular and unable to take into account three colors at the same time. At the same time, the diffraction angle of red light with a wavelength near 630nm will be too large, and part of its field of view angle cannot be coupled into the optical waveguide. Figure 1 As shown, the blue frame represents the field of view with a wavelength of 450nm, the green frame represents the field of view with a wavelength of 530nm, and the red frame represents the field of view with a wavelength of 630nm. It can be seen from the figure that when the blue field of view is completely coupled into the waveguide, only a part of the red field of view can be coupled into the waveguide, and the red field of view frame is close to the outside of the waveguide, indicating that the diffraction angle is too large, which will eventually lead to incompleteness of the red field of view, and reduced brightness and uniformity.

[0039] Therefore, the current single-light machine single-layer binocular waveguide has the problem of missing one or two field of view angles under the full-color light machine incident condition, resulting in insufficient brightness of the outcoupled image and reduced brightness uniformity and color uniformity.

[0040] The present invention proposes a single-optical-machine double-layer binocular display system, which can avoid the problem of missing one or two field of view angles, resulting in insufficient brightness of the coupled-out image, reduced brightness uniformity and color uniformity, and crosstalk between the double-layer waveguides by staggering the coupling-in units.

[0041] See also Figures 2 to 4 , which shows a single-optical-machine binocular dual-layer display system based on a beam splitting right-angle turning prism proposed in one embodiment of the present invention, the system includes an optical machine P00, a first optical waveguide layer Layer01 and a second optical waveguide layer Layer02, wherein:

[0042] The optical machine P00 is used to provide a light beam with a preset field of view angle, and can provide monochrome or full color. In a specific implementation, the optical machine P00 adopts a micro-projection optical machine P00, and the micro-projection optical machine P00 can be one of Micro-LEDs, LCOS, DLP or LBS. The preset angle of the field of view can be set according to actual conditions. Generally, the preset angle is set at 30° and above.

[0043] The first optical waveguide layer Layer01 is arranged on one side of the optical machine P00, and is used for receiving the light beam emitted by the optical machine P00. Specifically, a first coupling unit IG11 is provided in the first optical waveguide layer Layer01, and the first coupling unit IG11 is used for coupling the light beam into the first optical waveguide layer Layer01. More specifically, the light beam generally includes red light, green light and blue light, i.e., RGB three primary colors. The second optical waveguide layer Layer02 is arranged on the side of the first optical waveguide layer Layer01 away from the optical machine P00. A second coupling unit IG21 is provided in the second optical waveguide layer Layer02, and the second coupling unit IG21 is used for coupling the light beam not coupled into the first optical waveguide layer Layer01 into the first optical waveguide layer Layer01.

[0044] Specifically, the first coupling unit IG11 and the second coupling unit IG21 are staggered, and a beam splitting right-angle turning prism P01 is provided between the optical engine P00 and the first optical waveguide layer Layer01. The beam splitting right-angle turning prism P01 includes a layer of long-wave pass filter film S00, and the long-wave pass filter film S00 is used to reflect or transmit light of a preset wavelength. For example, for the full-color light beam emitted by the optical engine P00, light with a wavelength greater than 600nm has a high transmittance (T>96%), and light with a wavelength less than 600nm (420nm~580nm) has a high reflectivity (R>96%). Therefore, the field angles of green light and blue light in the light beam are reflected to the second coupling unit IG21, and the red light in the light beam is transmitted and reflected by the turning prism and then enters the first coupling unit IG11 of the first optical waveguide layer Layer01.

[0045] It can be understood that by setting two optical waveguide layers, the first coupling unit IG11 and the second coupling unit IG21 are respectively set in the two optical waveguide layers, and the beam splitting right-angle turning prism P01 is set between the optical machine P00 and the first optical waveguide layer Layer01, and by setting the long-wave pass filter film S00 on the beam splitting right-angle turning prism P01, the light of the preset wavelength is reflected or transmitted, and all the viewing angles of the green light and the blue light in the light beam are reflected to the second coupling unit IG21, and all the viewing angles of the red light in the light beam are reflected to the first coupling unit IG11, and the first and second coupling units IG21 are coupled to the first and second optical waveguides to achieve image coupling, ensuring that each color has a complete viewing angle, avoiding the lack of viewing angle, resulting in insufficient brightness of the coupled image, and reduced brightness uniformity and color uniformity. In addition, since the first coupling unit IG11 and the second coupling unit IG21 can be set in an offset manner, crosstalk between the double-layer waveguides can be avoided at the same time.

[0046] Further, more specifically, the period of the second coupling unit IG21 is:

[0047] ;

[0048] Where n is the waveguide refractive index, is the horizontal field of view, is the vertical field of view, is the central wavelength of the green light in the beam, is the central wavelength of the blue light in the beam. All viewing angles of blue and green light can be coupled into the optical waveguide.

[0049] The period of the first coupling unit IG11 is:

[0050] ;

[0051] in, is the central wavelength of the red light in the beam, n is the waveguide refractive index, 1 ≤M2≤1.2, 0.8 ≤N2≤1, is the horizontal field of view, is the vertical viewing angle. All viewing angles of red light can be coupled into the first light waveguide layer.

[0052] In addition, the centers of the first coupling unit IG11 and the second coupling unit IG21 correspond to the center positions of the first exit pupil and the second exit pupil of the light-splitting right-angle turning prism P01, respectively.

[0053] Furthermore, the thickness of the first waveguide layer Layer01 and the second waveguide layer are both 0.3 mm to 1 mm, the refractive index is both 1.6 to 2.5, and the spacing between the first waveguide layer Layer01 and the second waveguide layer is 0.03 mm to 0.08 mm; the first coupling unit IG11 and the second coupling unit IG21 are diffractive optical elements, which can be surface relief gratings or volume holographic gratings in specific implementations, preferably surface relief gratings such as rectangular gratings, tilted gratings or blazed gratings; the period of the first coupling unit IG11 is in the range of 400 to 500 nm; the period of the second coupling unit IG21 is in the range of 300 nm to 400 nm.

[0054] The first coupling unit IG11 is provided with a first turning coupling unit OG11 and a second turning coupling unit OG12 of the first optical waveguide layer Layer01 on both sides, and the first turning coupling unit OG21 and a second turning coupling unit OG22 of the second optical waveguide layer Layer02 on both sides of the second coupling unit IG21 are provided with a first turning coupling unit OG21 and a second turning coupling unit OG22 of the second optical waveguide layer Layer02 on both sides;

[0055] The first turning outcoupling unit OG11 and the second turning outcoupling unit OG12 of the first optical waveguide layer Layer01 and the first turning outcoupling unit OG21 and the second turning outcoupling unit OG22 of the second optical waveguide layer Layer02 are two-dimensional gratings or consist of two one-dimensional gratings.

[0056] In order to further describe the specific implementation process of the embodiment of the present invention in more detail, a more specific embodiment is used below to illustrate how the embodiment of the present invention achieves a large full field of view.

[0057] Among them, the central wavelength of the red light in the optical machine is =620nm, =530nm, =450nm, if FOV=40°, then =35°, =20°, n=1.9, T21 range: 335nm≤T 21 ≤354nm, take T 21 =350nm, the schematic diagram of the field angle coupling of green and blue light is as follows Figure 3 For details, please refer to Figure 2 , blue light and green light interact with the second coupling unit IG21, and their T+1 and T-1 diffraction orders are transmitted in the second waveguide layer Layer02 along the +X direction and -X direction respectively, and interact with the second turning coupling unit OG22 of the second waveguide layer Layer02 and the first turning coupling unit OG21 of the second waveguide layer Layer02 respectively, and then couple out from the waveguide after expansion and enter the left and right eyes (blue arrow and green arrow). Red light enters the first optical waveguide layer Layer01 after reflection by P01 and interacts with the first coupling unit IG11. The T+1 and T-1 orders generated by it can be fully reflected and transmitted therein, and are transmitted along the +X and -X directions respectively, and then are expanded and coupled out through the second turning coupling unit OG12 of the first optical waveguide layer Layer01 and the second turning coupling unit OG11 of the first optical waveguide layer Layer01, and enter the left and right eyes for imaging. If M2=1.12, N2=0.9, then 429nm≤T 21 ≤439nm, take T 11 =435nm. Corresponding Figure 4 As shown, the full viewing angle of red light is within the first optical waveguide layer Layer01 and is located in the middle of the ring.

[0058] In summary, the single-optical machine binocular dual-layer display system based on a beam splitting right-angle turning prism in the above-mentioned embodiment of the present invention is provided with two optical waveguide layers, and the first coupling unit IG11 and the second coupling unit IG21 are respectively provided in the two optical waveguide layers, and a beam splitting right-angle turning prism P01 is provided between the optical machine and the first optical waveguide layer Layer01, and a long-wave pass filter film S00 is provided on the beam splitting right-angle turning prism P01 to reflect or transmit light of a preset wavelength, so that all viewing angles of green light and blue light in the light beam are reduced. The red light in the light beam is reflected to the second coupling unit IG21, and all viewing angles of the red light in the light beam are reflected to the first coupling unit IG11, and coupled to the first and second optical waveguides through the first and second coupling units to realize image coupling out, thereby ensuring a complete viewing angle under each color, avoiding the lack of viewing angle, resulting in insufficient brightness of the coupled image, reduced brightness uniformity and color uniformity, and because the second coupling unit IG21 and the second coupling unit IG11 can be staggered, crosstalk between the double-layer waveguides can be avoided at the same time.

[0059] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A single-lens machine binocular double-layer display system based on a beam splitting right-angle turning prism, characterized in that: The system comprises: An optical machine, for providing a light beam with a field of view of a preset angle; A first optical waveguide layer, arranged at one side of the optical machine, wherein a first coupling unit is arranged in the first optical waveguide layer, and the first coupling unit is used to couple the light beam output by the optical machine into the first optical waveguide layer; A second optical waveguide layer is arranged on a side of the first optical waveguide layer away from the optical engine, wherein a second coupling unit is arranged in the second optical waveguide layer, and the second coupling unit is used to couple the light beam that is not coupled into the first optical waveguide layer into the first optical waveguide layer; Among them, the first coupling unit and the second coupling unit are staggered, and a beam splitting right-angle turning prism is provided between the optical machine and the first optical waveguide layer. The beam splitting right-angle turning prism includes a long-wave pass filter film, and the long-wave pass filter film is used to reflect or transmit light of a preset wavelength, and is used to reflect the field angles of green light and blue light in the light beam to the second coupling unit, and reflect the red light in the light beam to the first coupling unit.

2. The single-lens machine binocular double-layer display system based on a beam splitting right-angle turning prism according to claim 1, characterized in that: The first coupling unit and the second coupling unit are both diffractive optical elements, and the diffractive optical elements are surface relief gratings or volume holographic gratings; The surface relief grating is any one of a rectangular grating, a tilted grating and a blazed grating, and the period of the first coupling unit is: ； in, is the central wavelength of the red light in the beam, n is the waveguide refractive index, 1 ≤M2≤1.2, 0.8 ≤N2≤1, is the horizontal field of view, is the vertical field of view.

3. The single-lens machine binocular double-layer display system based on a beam splitting right-angle turning prism according to claim 2, characterized in that: The period of the second coupling unit is: ； Where n is the waveguide refractive index, is the horizontal field of view, is the vertical field of view, is the central wavelength of the green light in the beam, is the central wavelength of the blue light in the beam.

4. The single-lens machine binocular double-layer display system based on a beam splitting right-angle turning prism according to claim 1, characterized in that: The centers of the first coupling unit and the second coupling unit correspond to the center positions of the first exit pupil and the second exit pupil of the beam-splitting right-angle turning prism, respectively.

5. The single-lens machine binocular double-layer display system based on a beam splitting right-angle turning prism according to claim 1, characterized in that: The thickness of the first optical waveguide layer and the second optical waveguide layer are both 0.3 mm to 1 mm, and the refractive index is both 1.6 to 2.

5.

6. The single-lens machine binocular double-layer display system based on a beam splitting right-angle turning prism according to claim 1, characterized in that: The distance between the first optical waveguide layer and the second optical waveguide layer is 0.03 mm to 0.08 mm.

7. The single-lens machine binocular double-layer display system based on a beam splitting right-angle turning prism according to claim 1, characterized in that: A first turning outcoupling unit and a second turning outcoupling unit of the first optical waveguide layer are respectively disposed on both sides of the first coupling-in unit, and a first turning outcoupling unit and a second turning outcoupling unit of the second optical waveguide layer are respectively disposed on both sides of the second coupling-in unit; The first turning outcoupling unit and the second turning outcoupling unit of the first optical waveguide layer, and the first turning outcoupling unit and the second turning outcoupling unit of the second optical waveguide layer are two-dimensional gratings or consist of two one-dimensional gratings.

8. The single-lens machine binocular double-layer display system based on a beam splitting right-angle turning prism according to claim 2, characterized in that: The period of the first coupling unit is 400nm-500nm, and the period of the second coupling unit is 300nm-400nm.

9. The single-lens machine binocular double-layer display system based on a beam splitting right-angle turning prism according to claim 1, characterized in that: The optical engine is any one of Micro-LEDs, LCOS, DLP and LBS.

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