Light leakage eliminating near-to-eye display device

Abstract

The utility model discloses a light leakage eliminating near-to-eye display device, which comprises an optical machine, a first narrow-band optical filter, a waveguide and a second narrow-band optical filter, and is characterized in that the optical machine is used for providing imaging light; the first narrow-band optical filter is positioned on the light emitting side of the ray machine and is used for transmitting the imaging light in a first preset wavelength range; the waveguide is used for reflecting one part of the light transmitted by the first narrow-band optical filter to the second narrow-band optical filter and transmitting the other part of the light to human eyes; and the second narrow-band optical filter is used for absorbing the light reflected by the waveguide. According to the device, light leakage can be avoided, meanwhile, a user can normally watch a virtual image, privacy of the user is protected, visual experience and operation accuracy are improved, and the application range is wide.

Description

Technical Field

[0001] This utility model belongs to the field of near-eye display technology, specifically relating to a near-eye display device that eliminates light leakage. Background Technology

[0002] In recent years, Augmented Reality (AR) technology has been applied and rapidly developed in smart wearable devices. Smart wearable devices have high requirements for thinness and lightness, making waveguide solutions the preferred choice for lightweight AR glasses. However, waveguide solutions suffer from severe frontal light leakage, a problem that cannot be solved through waveguide design alone. That is, all existing waveguide solutions exhibit frontal light leakage, posing a risk of information leakage. This is because, during the finite element time-domain differential design of waveguides, diffracted light exists at different levels. For example, if +1st-order diffraction is required, there will be a -1st-order diffraction with similar energy. The two diffractions propagate in opposite directions; one enters the human eye, and the other propagates to the outside world.

[0003] Therefore, light leakage from the front of the waveguide in head-mounted displays is one of the major defects in wearable smart device display technology, especially common in diffractive waveguide solutions. Light leakage can lead to privacy breaches; the virtual image inside the glasses may be leaked into the external environment, allowing observers to see the content displayed on the user's glasses screen, such as navigation and information prompts. Alternatively, external light entering the glasses can reduce the contrast of the virtual image, affecting user privacy, reducing visual experience, and decreasing operational accuracy. Utility Model Content

[0004] The purpose of this invention is to address the above-mentioned problems by proposing a near-eye display device that eliminates light leakage. This device can prevent light leakage while allowing users to view virtual images normally, protecting user privacy, improving visual experience and operational accuracy, and has a wide range of applications.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0006] This utility model proposes a near-eye display device with light leakage reduction, comprising an optical engine, a first narrowband filter, a waveguide, and a second narrowband filter, wherein:

[0007] Optical engines are used to provide imaging light;

[0008] The first narrowband filter is located on the light-emitting side of the optical engine and is used to transmit imaging light within a first preset wavelength range;

[0009] A waveguide is used to reflect a portion of the light transmitted through a first narrowband filter to a second narrowband filter, while transmitting the other portion to the human eye.

[0010] The second narrowband filter is used to absorb light reflected from the waveguide.

[0011] Preferably, the thickness of the first narrowband filter and the second narrowband filter is 50nm-500nm.

[0012] Preferably, the optical engine is a monochromatic optical engine, and both the first narrowband filter and the second narrowband filter are monochromatic light filters.

[0013] Preferably, the first preset wavelength range is 450±30nm, 530±30nm, or 640±30nm.

[0014] Preferably, the optical engine is a color optical engine, and both the first narrowband filter and the second narrowband filter are color optical filters.

[0015] Preferably, the first preset wavelength range is 450±30nm, 530±30nm and 640±30nm.

[0016] Preferably, the first narrowband filter is attached or coated on the optomechanical system, and the second narrowband filter is attached or coated on the waveguide.

[0017] Preferably, the waveguide is a single-layer waveguide or a multi-layer waveguide, and the thickness is 0.3mm-4mm.

[0018] Preferably, the waveguide is a surface relief waveguide, a volume holographic waveguide, or an array waveguide.

[0019] Preferably, the optical engine is one of a DLP display, an LCOS display, a Micro OLED display, a Micro LED display, an LBS display, and an FSD display.

[0020] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0021] This near-eye light leakage elimination display device achieves light leakage elimination without affecting external transmittance by placing a first narrowband filter on the light-emitting side of the optical engine and a second narrowband filter on the non-near-eye side of the waveguide. It can be used not only in monochromatic light schemes but also in R / G / B full-color schemes. Specifically, the combination of the first and second narrowband filters makes it applicable to different optical engines. Since the center wavelength and half-width of different optical engines are not consistent, the first filter can constrain the spectral range, and the second filter, in conjunction with the first filter, can eliminate light leakage for different types of optical engines. This solves the problem of frontal light leakage caused by unwanted diffraction light in waveguide design and eliminates the need for the complex method of coating the waveguide grating in existing technologies, thus simplifying waveguide design and facilitating fabrication. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the near-eye light leakage elimination display device of this utility model;

[0023] Figure 2 This is a schematic diagram of the output wavelength of the monochromatic optical engine in Embodiment 1 of this utility model;

[0024] Figure 3 This is a schematic diagram of the working wavelength of the second narrowband filter in Embodiment 1 of this utility model;

[0025] Figure 4 This is a schematic diagram of the emitted wavelength of the color optical engine in Embodiment 2 of this utility model;

[0026] Figure 5 This is a schematic diagram of the working wavelength of the second narrowband filter in Embodiment 2 of this utility model.

[0027] Explanation of reference numerals in the attached figures: 1. Optical mechanism; 2. First narrowband filter; 3. Waveguide; 4. Second narrowband filter. Detailed Implementation

[0028] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0029] It should be noted that when a component is referred to as being "connected" to another component, it can be directly connected to the other component or there may be an intervening component. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the application.

[0030] Example 1:

[0031] like Figure 1-3 As shown, a near-eye display device with light leakage reduction includes an optomechanical system 1, a first narrowband filter 2, a waveguide 3, and a second narrowband filter 4, wherein:

[0032] Optical mechanism 1, used to provide imaging light;

[0033] The first narrowband filter 2 is located on the light-emitting side of the optical engine 1 and is used to transmit imaging light within a first preset wavelength range.

[0034] Waveguide 3 is used to reflect a portion of the light transmitted through the first narrowband filter 2 to the second narrowband filter 4, and transmit the other portion to the human eye;

[0035] The second narrowband filter 4 is used to absorb the light reflected from the waveguide 3.

[0036] In this design, the first narrowband filter 2 is a transmission-type narrowband filter, and the second narrowband filter 4 is an absorption-type narrowband filter. The optical engine 1, the first narrowband filter 2, and the second narrowband filter 4 are all located on the same side of the waveguide 3. By placing the first narrowband filter 2 on the light-emitting side of the optical engine 1 and the second narrowband filter 4 on the non-eye-friendly side of the waveguide 3, front-side light leakage is eliminated without affecting external transmittance. This is applicable not only to monochromatic light but also to R / G / B full-color schemes. The combination of the first narrowband filter 2 and the second narrowband filter 4 allows for application to different optical engines, solving the problem of front-side light leakage caused by unwanted diffraction light in waveguide design. It also eliminates the need for the complex method of coating the grating on the waveguide 3 used in existing technologies for light leakage elimination, thus simplifying waveguide design and facilitating fabrication.

[0037] At work, such as Figure 1 As shown, the imaging light emitted by the optical engine 1 passes through the first narrowband filter 2, and then the imaging light (S) within the first preset wavelength range is transmitted and enters the waveguide 3. The waveguide 3 reflects a portion of the light (R) to the second narrowband filter 4 for absorption to eliminate light leakage, while the other portion of the light (T) is transmitted to the human eye.

[0038] In one embodiment, the thickness of the first narrowband filter 2 and the second narrowband filter 4 is 50nm-500nm. A thickness within this range is beneficial for film formation and transfer; thinner films cannot be formed, and excessive thickness will affect transmittance.

[0039] In one embodiment, the optical engine 1 is a monochromatic optical engine, and the first narrowband filter 2 and the second narrowband filter 4 are both monochromatic light filters.

[0040] In one embodiment, the first preset wavelength range is 450±30nm, 530±30nm, or 640±30nm.

[0041] Specifically, the imaging light emitted from the optical engine 1 passes through the first narrowband filter 2 and exits as monochromatic light (green light) with a wavelength of 530nm, while other wavelengths are cut off. A second narrowband filter 4, which absorbs the 530nm wavelength, is deposited on the waveguide 3. This absorbs the 530nm monochromatic light reflected from the waveguide 3. Since no narrowband filter is deposited on the side near the eye, it does not affect the viewing of the virtual image. Furthermore, because it is a narrowband filter, it does not affect the transmittance when viewing the outside world. It is easy to understand that the filter can also be selected according to actual needs; for example, the light emitted after passing through the first narrowband filter 2 can be of different wavelengths and colors.

[0042] In one embodiment, the first narrowband filter 2 is attached or deposited on the optomechanical system 1, and the second narrowband filter 4 is attached or deposited on the waveguide 3. Each narrowband filter can be in the form of a coating or a coating, and has a wide range of applications. For example, it is also widely applicable to the waveguide 3, as it can be a waveguide made of glass or a waveguide made of plastic.

[0043] In one embodiment, waveguide 3 is a single-layer waveguide or a multi-layer waveguide, with a thickness of 0.3mm-4mm. A waveguide that is too thin will affect the display effect and reliability, while one that is too thick will increase the weight. This range ensures both display effect and facilitates miniaturization and lightweight design. Waveguide 3 is preferably a single-layer or double-layer waveguide, and can also be designed as a three-layer or higher waveguide according to actual needs.

[0044] In one embodiment, waveguide 3 is a surface relief waveguide, a volume holographic waveguide, or an array waveguide. The specific waveguide type can be selected according to actual needs.

[0045] In one embodiment, the optical engine 1 is one of a DLP display, an LCOS display, a Micro OLED display, a Micro LED display, an LBS display, and an FSD display.

[0046] Among them, the optical engine 1, as the core component of near-eye display technology, directly affects the final display effect, size, and user experience. For example, a Micro OLED display or a Micro LED display is preferred, as it has high brightness and high contrast characteristics, and the resolution can be improved by reducing the pixel size while reducing power consumption, thus meeting the lightweight requirements of AR / VR devices. It is easy to understand that those skilled in the art are not limited to the display types listed above, and can also select the model according to actual needs.

[0047] Example 2:

[0048] like Figure 1 , 4 As shown in Figure 5, a near-eye display device with light leakage reduction includes an optomechanical system 1, a first narrowband filter 2, a waveguide 3, and a second narrowband filter 4, wherein:

[0049] Optical mechanism 1, used to provide imaging light;

[0050] The first narrowband filter 2 is located on the light-emitting side of the optical engine 1 and is used to transmit imaging light within a first preset wavelength range.

[0051] Waveguide 3 is used to reflect a portion of the light transmitted through the first narrowband filter 2 to the second narrowband filter 4, and transmit the other portion to the human eye;

[0052] The second narrowband filter 4 is used to absorb the light reflected from the waveguide 3.

[0053] In this design, the first narrowband filter 2 is a transmission-type narrowband filter, and the second narrowband filter 4 is an absorption-type narrowband filter. The optical engine 1, the first narrowband filter 2, and the second narrowband filter 4 are all located on the same side of the waveguide 3. By placing the first narrowband filter 2 on the light-emitting side of the optical engine 1 and the second narrowband filter 4 on the non-eye-friendly side of the waveguide 3, front-side light leakage is eliminated without affecting external transmittance. This is applicable not only to monochromatic light but also to R / G / B full-color schemes. The combination of the first narrowband filter 2 and the second narrowband filter 4 allows for application to different optical engines, solving the problem of front-side light leakage caused by unwanted diffraction light in waveguide design. It also eliminates the need for the complex method of coating the grating on the waveguide 3 used in existing technologies for light leakage elimination, thus simplifying waveguide design and facilitating fabrication.

[0054] At work, such as Figure 1 As shown, the imaging light emitted by the optical engine 1 passes through the first narrowband filter 2, and then the imaging light (S) within the first preset wavelength range is transmitted and enters the waveguide 3. The waveguide 3 reflects a portion of the light (R) to the second narrowband filter 4 for absorption to eliminate light leakage, while the other portion of the light (T) is transmitted to the human eye.

[0055] In one embodiment, the thickness of the first narrowband filter 2 and the second narrowband filter 4 is 50nm-500nm. A thickness within this range is beneficial for film formation and transfer; thinner films cannot be formed, and excessive thickness will affect transmittance.

[0056] In one embodiment, the optical engine 1 is a color optical engine, and the first narrowband filter 2 and the second narrowband filter 4 are both color optical filters.

[0057] In one embodiment, the first preset wavelength range is 450±30nm, 530±30nm and 640±30nm.

[0058] Specifically, the imaging light emitted from the optical engine 1 passes through the first narrowband filter 2 and emits colored light with wavelengths of 450±30nm (blue light), 530±30nm (green light), and 640±30nm (red light), while other wavelengths are cut off. A second narrowband filter 4 is deposited on the waveguide 3 to absorb the wavelengths of 450±30nm (blue light), 530±30nm (green light), and 640±30nm (red light). This absorbs the colored light reflected from the waveguide 3. Since no narrowband filter is deposited on the side near the eye, it does not affect the viewing of the virtual image. At the same time, because it is a narrowband filter, it does not affect the transmittance when viewing the outside world.

[0059] In one embodiment, the first narrowband filter 2 is attached or deposited on the optomechanical system 1, and the second narrowband filter 4 is attached or deposited on the waveguide 3. Each narrowband filter can be in the form of a coating or a coating, and has a wide range of applications. For example, it is also widely applicable to the waveguide 3, as it can be a waveguide made of glass or a waveguide made of plastic.

[0060] In one embodiment, waveguide 3 is a single-layer waveguide or a multi-layer waveguide, with a thickness of 0.3mm-4mm. A waveguide that is too thin will affect the display effect and reliability, while one that is too thick will increase the weight. This range ensures both display effect and facilitates miniaturization and lightweight design. Waveguide 3 is preferably a single-layer or double-layer waveguide, and can also be designed as a three-layer or higher waveguide according to actual needs.

[0061] In one embodiment, waveguide 3 is a surface relief waveguide, a volume holographic waveguide, or an array waveguide. The specific waveguide type can be selected according to actual needs.

[0062] In one embodiment, the optical engine 1 is one of a DLP display, an LCOS display, a Micro OLED display, a Micro LED display, an LBS display, and an FSD display.

[0063] Among them, the optical engine 1, as the core component of near-eye display technology, directly affects the final display effect, size, and user experience. For example, a Micro OLED display or a Micro LED display is preferred, as it has high brightness and high contrast characteristics, and the resolution can be improved by reducing the pixel size while reducing power consumption, thus meeting the lightweight requirements of AR / VR devices. It is easy to understand that those skilled in the art are not limited to the display types listed above, and can also select the model according to actual needs.

[0064] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0065] The embodiments described above are merely specific and detailed examples of the embodiments described in this application, and should not be construed as limiting the scope of the application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these modifications and improvements all fall within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the appended claims.

Claims

1. A near-eye display device that eliminates light leakage, characterized in that: The near-eye display device with light leakage elimination includes an optical engine (1), a first narrowband filter (2), a waveguide (3), and a second narrowband filter (4), wherein: The optical engine (1) is used to provide imaging light; The first narrowband filter (2) is located on the light-emitting side of the optomechanical system (1) and is used to transmit imaging light within a first preset wavelength range; The waveguide (3) is used to reflect a portion of the light transmitted by the first narrowband filter (2) to the second narrowband filter (4), and transmit the other portion to the human eye; The second narrowband filter (4) is used to absorb the light reflected by the waveguide (3).

2. The near-eye display device for eliminating light leakage as described in claim 1, characterized in that: The thickness of the first narrowband filter (2) and the second narrowband filter (4) is 50nm-500nm.

3. The near-eye display device with light leakage elimination as described in claim 1, characterized in that: The optical engine (1) is a monochromatic optical engine, and the first narrowband filter (2) and the second narrowband filter (4) are both monochromatic light filters.

4. The near-eye display device for eliminating light leakage as described in claim 3, characterized in that: The first preset wavelength range is 450±30nm, 530±30nm, or 640±30nm.

5. The near-eye display device with light leakage elimination as described in claim 1, characterized in that: The optical engine (1) is a color optical engine, and the first narrowband filter (2) and the second narrowband filter (4) are both color optical filters.

6. The near-eye display device for eliminating light leakage as described in claim 5, characterized in that: The first preset wavelength range is 450±30nm, 530±30nm and 640±30nm.

7. The near-eye display device with light leakage elimination as described in claim 1, characterized in that: The first narrowband filter (2) is attached or plated on the optomechanical system (1), and the second narrowband filter (4) is attached or plated on the waveguide (3).

8. The near-eye display device with light leakage elimination as described in claim 1, characterized in that: The waveguide (3) is a single-layer waveguide or a multi-layer waveguide, and its thickness is 0.3mm-4mm.

9. The near-eye display device with light leakage elimination as described in claim 8, characterized in that: The waveguide (3) is a surface relief waveguide, a volume holographic waveguide, or an array waveguide.

10. The near-eye display device with light leakage elimination as described in claim 1, characterized in that: The optical engine (1) is one of the following: DLP display, LCOS display, Micro OLED display, Micro LED display, LBS display and FSD display.

Images