Optical display system and near-eye display device

Abstract

The invention provides an optical display system and near-to-eye display equipment, the optical display system comprises a micro projection module, and the micro projection module is used for emitting first light; the optical waveguide module and the micro-projection module are oppositely arranged, the optical waveguide module is used for coupling in and transmitting the first light, and part of the first light is reflected by the optical waveguide module to form second light; and the polarization module is arranged between the micro-projection module and the optical waveguide module, and the polarization module is used for transmitting the first light and preventing the second light from entering the optical waveguide module. The optical display system can prevent human eyes from seeing stray light.

Description

Technical Field

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

[0002] In near-eye display devices, the micro-projection module projects light to the optical waveguide module for coupling in and out, and the light eventually enters the human eye, which can display a virtual image within a predetermined distance in front of the human eye. Because the optical waveguide module has a certain reflectivity, when the projected light is coupled into the optical waveguide, part of the light will be reflected back to the micro-projection module, and then reflected on the micro-projection module and continued to propagate into the optical waveguide module, causing the human eye to see stray light such as "ghost images", affecting the user experience. Summary of the invention

[0003] Embodiments of the present application provide an optical display system and a near-eye display device, which can prevent stray light from being seen by human eyes.

[0004] The present application provides an optical display system, including:

[0005] A micro-projection module, wherein the micro-projection module is used to emit a first light;

[0006] An optical waveguide module, the optical waveguide module is arranged opposite to the micro-projection module, the optical waveguide module is used to couple in and transmit the first light, and part of the first light is reflected by the optical waveguide module to form a second light;

[0007] A polarizing module, wherein the polarizing module is disposed between the micro-projection module and the optical waveguide module, and is used for transmitting the first light and blocking the second light from entering the optical waveguide module.

[0008] In some embodiments, the polarization module includes a linear polarizer and a quarter wave plate, and in the direction from the micro-projection module toward the optical waveguide module, the quarter wave plate and the linear polarizer are sequentially arranged.

[0009] In some embodiments, the second light passes through the linear polarizer to form a first linear polarized light, the first linear polarized light passes through the quarter wave plate to form a first circularly polarized light, at least part of the first circularly polarized light is reflected by the micro-projection module to form a second circularly polarized light, and the second circularly polarized light passes through the quarter wave plate to form a second linear polarized light; the linear polarizer is used to block the linear polarized light.

[0010] In some embodiments, the micro-projection module includes a plurality of pixel units arranged in an array, and the pixel units are used to emit the first light.

[0011] In some embodiments, the linear polarizer includes a plurality of polarization units, and the polarization units correspond to the pixel units one by one; when the pixel unit emits light, the polarization units corresponding to the pixel units are in a light-transmitting state; when the pixel unit is off, the polarization units corresponding to the pixel units are in a polarized state.

[0012] In some embodiments, the material of the polarization unit is an anisotropic material.

[0013] In some embodiments, the optical waveguide module includes a waveguide substrate, an in-coupling grating and an out-coupling grating. The in-coupling grating and the out-coupling grating are arranged on the waveguide substrate, and the in-coupling grating is a reflection grating.

[0014] In some embodiments, the optical display system further includes an optical module, which is disposed on a light-emitting side of the micro-projection module; the optical module includes at least one imaging lens, which is used to adjust the light beam.

[0015] In some embodiments, the optical module is disposed between the micro-projection module and the optical waveguide module; or, the optical module is disposed between the optical waveguide module and the polarization module.

[0016] An embodiment of the present application also provides a near-eye display device, comprising the above-mentioned optical display system.

[0017] In the optical display system and near-eye display device provided in the embodiments of the present application, the optical display system includes a micro-projection module, an optical waveguide module and a polarizing module, wherein the micro-projection module is used to emit a first light, the optical waveguide module is used to couple into and transmit the first light, part of the first light is reflected by the optical waveguide module to form a second light, the polarizing module is arranged between the micro-projection module and the optical waveguide module, and the polarizing module is used to transmit the first light and block the second light from entering the optical waveguide module. Since the second light is the main cause of stray light, the polarizing module blocks the stray light from entering the optical waveguide module, thereby preventing the human eye from seeing stray light. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application, and those skilled in the art can obtain other drawings based on these drawings without creative work.

[0019] Figure 1 A schematic diagram of the structure of a near-eye display device in the prior art provided in an embodiment of the present application.

[0020] Figure 2A schematic diagram of the structure of an optical display system provided in an embodiment of the present application.

[0021] Figure 3 The first schematic diagram shows that various structures in the optical display system provided in an embodiment of the present application are placed in sequence.

[0022] Figure 4 A second schematic diagram showing the sequential placement of various structures in the optical display system provided in an embodiment of the present application.

[0023] Figure 5 A first structural schematic diagram of a near-eye display device provided in an embodiment of the present application.

[0024] Figure 6 A second structural schematic diagram of the near-eye display device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0026] See also Figure 1 , Figure 1 A schematic diagram of the structure of a near-eye display device in the prior art provided in an embodiment of the present application. The near-eye display device described herein is a device that is configured at a certain distance (generally 2-5 cm) in front of the user's eyes and directly presents the display content in front of the user, such as a head-mounted display in a virtual reality device, an optical perspective glasses in an augmented reality device, and so on.

[0027] In the near-eye display device 2, the micro-projection module 201 is responsible for projecting light to the optical waveguide module 202, completing the coupling-in and coupling-out process of light, thereby presenting an image in front of the human eye. However, since the optical waveguide module 202 has certain reflective properties, part of the light will be reflected back to the micro-projection module 201. After being reflected again in the micro-projection module, these lights will re-enter the optical waveguide module 202. This cycle process causes the human eye to observe stray light such as "ghost images", which seriously affects the user experience.

[0028] The embodiments of the present application provide an optical display system and a near-eye display device, which can prevent human eyes from seeing stray light, and are described in detail below with reference to the accompanying drawings.

[0029] See also Figure 2 , Figure 2 A schematic diagram of the structure of an optical display system provided in an embodiment of the present application.

[0030] The embodiment of the present application provides an optical display system 100, including a micro-projection module 10, an optical waveguide module 20, and a polarizing module 30. The micro-projection module 10 is used to emit a first light. The optical waveguide module 20 is arranged opposite to the micro-projection module 10, and the optical waveguide module 20 is used to couple in and transmit the first light, and part of the first light is reflected by the optical waveguide module 20 to form a second light. The polarizing module 30 is arranged between the micro-projection module 10 and the optical waveguide module 20, and the polarizing module 30 is used to transmit the first light and block the second light from entering the optical waveguide module 20.

[0031] The micro-projection module 10 may include various display screens that can emit light and display images, such as LED miniaturization and matrix technology display screens (Micro LED display screens), OLED miniaturization and matrix technology display screens (MicroOLED display screens), laser beam scanning display screens (LBS display screens), and digital mirror display screens (DMD display screens). The micro-projection module 10 is also called a micro-display, a light engine, an optical engine, etc. If these terms are not specifically specified, they can be used interchangeably in this application.

[0032] The optical waveguide module 20 is used to combine the light emitted by the micro-projection module 10 with the light of the real scene, and transmit it to the user's human eye 200 for viewing. The optical waveguide module 20 may include a waveguide substrate 21, an in-coupling grating 22, and an out-coupling grating, and the in-coupling grating 22 and the out-coupling grating are both arranged on the waveguide substrate 21. The in-coupling grating 22 may be a reflective grating. The optical waveguide module 20 may be, but is not limited to, a diffraction optical waveguide, a geometric optical waveguide, and a holographic optical waveguide.

[0033] The coupling-in grating 22 is correspondingly arranged at the light-emitting side of the micro-projection module 10, and the coupling-out grating is correspondingly arranged at the position of the user's human eye 200. The coupling-in grating 22 can couple the light emitted by the micro-projection module 10 into the optical waveguide substrate 21, and the light is totally reflected in the optical waveguide substrate 21, and finally coupled out from the coupling-out grating to the user's human eye 200.

[0034] In the embodiment of the present application, the number of the coupling-in grating 22 , the waveguide substrate 21 , and the coupling-out grating is not limited.

[0035] The polarizing module 30 is designed to allow part of the light emitted by the micro-projection module 10 (i.e., the first light) to pass smoothly, while effectively blocking the light reflected back to the micro-projection module 10 by the optical waveguide module 20 (i.e., the second light). Specifically, the micro-projection module 10 is responsible for emitting the first light, and a part of these lights will be reflected when passing through the optical waveguide module 20 to form the second light. The role of the polarizing module 30 is that it allows the first light to penetrate unimpeded, while blocking the second light - the main factor causing stray light - outside the optical waveguide module 20. In this way, the polarizing module 30 successfully prevents stray light from entering the optical waveguide module 20, thereby ensuring that the human eye 200 does not see any stray light that interferes with vision.

[0036] The polarizing module 30 includes a linear polarizing plate 31 and a quarter wave plate 32. The quarter wave plate 32 and the linear polarizing plate 31 are sequentially arranged in the direction from the micro-projection module 10 to the optical waveguide module 20. In other words, the micro-projection module 10, the quarter wave plate 32, the linear polarizing plate 31 and the optical waveguide module 20 are sequentially arranged.

[0037] The second light reflected from the optical waveguide module 20 passes through the linear polarizer 31 to form a first linear polarized light, and the first linear polarized light passes through the quarter wave plate 32 to form a first circular polarized light. At least part of the first circular polarized light is reflected by the micro-projection module 10 to form a second circular polarized light, and the second circular polarized light passes through the quarter wave plate 32 to form a second linear polarized light; the linear polarizer 31 is used to block the linear polarized light. The linear polarizer 31 is also called a half wave plate. The polarizer can transmit the first linear polarized light and reflect the second polarized light, and the polarization states of the first polarized light and the second polarized light are perpendicular.

[0038] When the micro-projection module 10 is a micro LED display screen, the micro-projection module 10 includes a plurality of pixel units arranged in an array, and the pixel unit is used to emit a first light. The pixel unit includes a plurality of light-emitting units, for example, each pixel unit includes three light-emitting units, specifically a red light-emitting unit, a green light-emitting unit, and a blue light-emitting unit. In each frame of the image projected by the micro-projection module 10, the pixel unit emits light in a specific mode, some of the pixel units are lit to display image information, and the other part remains off to optimize the display effect and reduce energy consumption.

[0039] In order to further improve the utilization rate of light, the linear polarizer 31 includes a plurality of polarization units, and the polarization units correspond to the pixel units one by one; when the pixel unit emits light, the polarization unit corresponding to the pixel unit is in a light-transmitting state; when the pixel unit is off, that is, the pixel unit does not emit light, the polarization unit corresponding to the pixel unit is in a polarized state. In this way, when the first light emitted by the pixel unit can smoothly pass through the quarter and linear polarizers 31 in sequence, it will not affect the utilization rate and light intensity of the first light emitted to the optical waveguide module 20. For the second light reflected from the micro-projection module 10, the polarization unit in a polarized state can block the second light from entering the optical waveguide module 20. This not only ensures the effective utilization of light, but also significantly improves the overall performance of the system.

[0040] The micro-projection module 10 not only has the function of playing pictures, but also can play videos smoothly. When playing pictures, since the light-emitting state and position of the pixel unit are fixed, the light-transmitting state and polarization state of the polarization unit also remain unchanged, ensuring the stable display of the image. When playing a video, as the picture switches quickly, the state of the polarization unit also needs to be adjusted accordingly. In this case, the material of the polarization unit can be an anisotropic material, which can then change between a polarization state and a transparent state. In order to achieve the change between the transparent state and the polarization state of the polarization unit, power can be applied to each anisotropic material to change its molecular form. For example, the anisotropic material is a liquid crystal, and its molecular arrangement is changed by the action of an electric field, so as to flexibly switch between the transparent state and the polarization state, thereby achieving the flexible switching of the polarization unit between the transparent state and the polarization state, which not only meets the demand for dynamic display effects during video playback, but also demonstrates the high flexibility and adaptability of the system.

[0041] See also Figure 3 as well as Figure 4 , Figure 3 A first schematic diagram of the sequential placement of various structures in the optical display system provided in an embodiment of the present application, Figure 4 A second schematic diagram of the various structures in the optical display system provided in the embodiment of the present application are placed in order. The optical display system 100 also includes an optical module 40, which is arranged on the light-emitting side of the micro-projection module 10. The optical module 40 includes at least one imaging lens, which is used to adjust the light beam to improve the utilization rate of the first light.

[0042] In some cases, the optical module 40 is disposed between the micro-projection module 10 and the polarization module 30. In other cases, the optical module 40 is disposed between the optical waveguide module 20 and the polarization module 30. It can be seen that the configuration of the optical module 40 not only fully utilizes the space between the micro-projection module 10 and the polarization module 30, and between the optical waveguide module 20 and the polarization module 30, but also effectively improves the space utilization of the entire system, demonstrating the ingenuity and efficiency of the design.

[0043] See also Figure 5 as well as Figure 6 , Figure 5 A schematic diagram of a first structure of a near-eye display device provided in an embodiment of the present application, Figure 6 A second structural schematic diagram of a near-eye display device provided in an embodiment of the present application. The present application provides a near-eye display device 1, comprising the above-mentioned optical display system 100. The near-eye display device 1 includes but is not limited to AR head-mounted devices such as AR (Augmented Reality) glasses and AR helmets. The near-eye display device 1 may also include a fixing part 300 such as a glasses temple 301 or a glasses frame 302, and the fixing part 300 is fixed to the optical display system 100, and the fixing part 300 is used to install, fix or carry the optical display system 100.

[0044] The near-eye display device 1 may include lenses, vision corrective lenses or non-corrective lenses, such as prescription glasses, bifocal glasses, reading glasses, driving glasses and progressive glasses. Examples of vision corrective lenses or non-corrective lenses are sunglasses, adapter glasses, safety glasses, sports glasses, swimming masks or goggles and ski goggles.

[0045] The near-eye display device 1 may also include wraparound glasses (with wraparound lenses), adaptable glasses or auxiliary frames (attached to existing frames). Furthermore, the near-eye display device 1 may include a strap for glasses, such as a strap for fixing the near-eye display device 1 to the user's head. The main frame of the near-eye display device 1, such as the temples 301 and the frame 302 of the glasses, forms an inner cavity, and the inner cavity is provided with an electronic circuit, and the electronic circuit includes common electronic components such as a flexible circuit board, a chip motherboard, and a power supply. The near-eye display device 1 may also be electrically connected to an acceleration processor such as a GPU / CPU / NPU, and electrically connected to sensors such as a camera, a gyroscope, an IMU, an eye tracker, and an electromyograph.

[0046] In the optical display system 100 and the near-eye display device 1 provided in the embodiment of the present application, the optical display system 100 includes a micro-projection module 10, an optical waveguide module 20 and a polarizing module 30, wherein the micro-projection module 10 is used to emit a first light, the optical waveguide module 20 is used to couple and transmit the first light, part of the first light is reflected by the optical waveguide module 20 to form a second light, and the polarizing module 30 is arranged between the micro-projection module 10 and the optical waveguide module 20, and the polarizing module 30 is used to transmit the first light and block the second light from entering the optical waveguide module 20. The second light is the main cause of stray light, and the polarizing module 30 blocks the stray light from entering the optical waveguide module 20, so that the human eye 200 can avoid seeing stray light.

[0047] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0048] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more features.

[0049] The optical display system and near-eye display device provided by the embodiments of the present application are described in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the present application, and the description of the above embodiments is only used to help understand the present application. At the same time, for those skilled in the art, according to the ideas of the present application, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as limiting the present application.

Claims

1. An optical display system, characterized in that: include: A micro-projection module, wherein the micro-projection module is used to emit a first light; An optical waveguide module, the optical waveguide module is arranged opposite to the micro-projection module, the optical waveguide module is used to couple in and transmit the first light, and part of the first light is reflected by the optical waveguide module to form a second light; A polarizing module, wherein the polarizing module is disposed between the micro-projection module and the optical waveguide module, and is used for transmitting the first light and blocking the second light from entering the optical waveguide module.

2. The optical display system according to claim 1, characterized in that: The polarizing module comprises a linear polarizing plate and a quarter wave plate. In the direction from the micro-projection module to the optical waveguide module, the quarter wave plate and the linear polarizing plate are arranged in sequence.

3. The optical display system according to claim 2, characterized in that: The second light passes through the linear polarizer to form a first linear polarized light, the first linear polarized light passes through the quarter wave plate to form a first circular polarized light, at least part of the first circular polarized light is reflected by the micro-projection module to form a second circular polarized light, and the second circular polarized light passes through the quarter wave plate to form a second linear polarized light; The linear polarizing plate is used to block the linear polarized light.

4. The optical display system according to claim 2, characterized in that: The micro-projection module includes a plurality of pixel units arranged in an array, and the pixel units are used to emit the first light.

5. The optical display system according to claim 4, characterized in that: The linear polarizer includes a plurality of polarization units, and the polarization units correspond to the pixel units one by one; when the pixel unit emits light, the polarization units corresponding to the pixel unit are in a light-transmitting state; when the pixel unit is off, the polarization units corresponding to the pixel unit are in a polarized state.

6. The optical display system according to claim 5, characterized in that: The material of the polarization unit is anisotropic material.

7. The optical display system according to any one of claims 1 to 6, characterized in that: The optical waveguide module comprises a waveguide substrate, an in-coupling grating and an out-coupling grating. The in-coupling grating and the out-coupling grating are arranged on the waveguide substrate, and the in-coupling grating is a reflection grating.

8. The optical display system according to any one of claims 1 to 6, characterized in that: It also includes an optical module, which is arranged on the light-emitting side of the micro-projection module; the optical module includes at least one imaging lens, which is used to adjust the light beam.

9. The optical display system according to claim 8, characterized in that: The optical module is arranged between the micro-projection module and the optical waveguide module; or, the optical module is arranged between the optical waveguide module and the polarization module.

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

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