Optical devices with selective absorption and adjustable transmittance, and augmented reality devices.

Abstract

This invention relates to an optical device with selective absorption and adjustable transmittance, and an augmented reality device. The optical device includes: a first light plate assembly; at least one first type polarizer is disposed on the front side of the first light plate assembly; the first type polarizer is a polarizer rotatable relative to the first light plate assembly; at least one second light plate assembly is selectively disposed on the back side of the first light plate assembly; the first light plate assembly includes: a first polarizer, a first waveplate, and a second polarizer arranged sequentially and in parallel; the first waveplate is used to rotate the vibration direction of light rays with wavelengths corresponding to the first waveplate after light enters the first waveplate; each second light plate assembly includes a second waveplate and a third polarizer arranged sequentially and in parallel; the second waveplate is used to rotate the vibration direction of light rays with wavelengths corresponding to the second waveplate after light enters the second waveplate.

Description

Technical Field

[0001] The present invention relates to the technical field of augmented reality, and in particular to an optical device with selective absorption and adjustable transmittance and an augmented reality device. Background Art

[0002] Augmented Reality (AR) is a technology that organically integrates the images of the virtual world and the scenes of the real world. It can superimpose virtual information on the real world and has a wide range of applications in all walks of life. Existing augmented reality display devices (waveguide Birdbath, prism, etc.) all have a part of the light emitted to the outside world, and there is a light leakage phenomenon. Although a reflection elimination device and an augmented reality display device are disclosed in the patent document with publication number CN111399232A, and the reflection elimination device eliminates or weakens the light reflected and scattered to the outside world by the human eye and the surrounding skin when wearing an augmented reality display device, there are still many problems with the existing augmented reality display device. For example, when the augmented reality display device is in an environment with high brightness, the ambient light will drown out the light that displays the virtual image, causing the wearer to be unable to comfortably obtain the virtual image. At the same time, when the existing augmented reality display device is used in an environment with high brightness, there are still problems with insufficient brightness or high power consumption.

[0003] In addition, existing augmented reality display devices such as Figure 4 As shown, it consists of two parts, namely, an optomechanical module and an optical combiner. The optomechanical module is used to generate optical signals that carry virtual image information; a part of the light that displays the virtual image is emitted from the optomechanical module, reaches the optical combiner, and then enters the human eye from the human eye side through reflection, diffraction, etc., and the other part is emitted from the outside of the optical combiner (facing the external environment) so that other people can see it, which may cause the leakage of information displayed by the augmented reality display device, and affect the natural and beautiful appearance of the wearer, making it look weird. If you wear an augmented reality display device to participate in military operations at night or other operations that require concealment, it is easy to expose the wearer's position.

[0004] It can be seen that the augmented reality display device in the prior art has the problem that the wearer cannot comfortably obtain the virtual image due to the inability to adjust the transmittance of light, and the prior art cannot selectively absorb light of a specified wavelength, which easily exposes the wearer's position. Summary of the invention

[0005] 1. Technical issues to be resolved

[0006] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides an optical device and an augmented reality device with selective absorption and adjustable transmittance, which solve the technical problems in the prior art that the augmented reality display device cannot adjust the transmittance of light, resulting in the wearer's inability to comfortably obtain virtual images, and the prior art cannot selectively absorb light of a specified wavelength, which easily exposes the wearer's position.

[0007] (II) Technical solution

[0008] In order to achieve the above object, the main technical solutions adopted by the present invention include:

[0009] In a first aspect, an embodiment of the present invention provides an optical device with selective absorption and adjustable transmittance, comprising:

[0010] a first light sheet assembly;

[0011] At least one first type polarizer 24 is disposed on the front side of the first optical sheet assembly;

[0012] The first type polarizer 24 is a polarizer that can rotate relative to the first optical sheet assembly;

[0013] At least one second optical sheet assembly is selectively disposed on the reverse side of the first optical sheet assembly;

[0014] The first optical sheet assembly comprises: a first polarizing sheet 23, a first wave plate 22, and a second polarizing sheet 21 which are arranged sequentially and in parallel;

[0015] The first wave plate 22 is used to rotate the vibration direction of the light with a wavelength corresponding to the first wave plate after the light enters the first wave plate 22;

[0016] Each of the second optical sheet assemblies comprises a second wave plate 42 and a third polarizing plate 41 which are arranged in parallel in sequence;

[0017] The second wave plate 42 is used to rotate the vibration direction of the light with a wavelength corresponding to the second wave plate after the light enters the second wave plate;

[0018] Each of the first wave plate 22 and the second wave plate 42 is made of different materials;

[0019] or,

[0020] The first wave plate 22 and the second wave plate 42 are made of the same material and have different thicknesses.

[0021] Preferably,

[0022] In the first optical sheet assembly, the angle between the light transmission axis of the second polarizer 21 and the optical axis of the first wave plate 22 is 45°;

[0023] The light transmission axis of the first polarizer 23 and the light transmission axis of the second polarizer 22 are 90° or 180°.

[0024] Preferably,

[0025] The first wave plate 22 realizes rotating the vibration direction of the light of the first specified wavelength corresponding to the first wave plate by 90° after the light enters the first wave plate.

[0026] Preferably,

[0027] The optical axis of the second wave plate 42 in each second optical plate assembly is 45° to the transmission axis of the third polarizer 41; and the transmission axis of the third polarizer 41 or the second polarizer 21 adjacent to the first side of each second wave plate 42 is 90° or 180° to the transmission axis of the third polarizer 41 adjacent to the second side of the second wave plate 42.

[0028] Preferably,

[0029] Each of the first wave plate 22 and the second wave plate 42 corresponds to light of different wavelengths.

[0030] Preferably,

[0031] The first wave plate 22 and the second wave plate 42 are both multi-order wave plates.

[0032] Preferably,

[0033] The thickness of each of the first wave plate 22 and the second wave plate 42 is different.

[0034] In a second aspect, an augmented reality display device comprises any of the above-mentioned optical devices with selective absorption and adjustable transmittance.

[0035] Preferably, the selectively absorbing optical device with adjustable transmittance is arranged on the outward side of the optical combiner of the augmented reality display device.

[0036] (III) Beneficial effects

[0037] The beneficial effects of the present invention are: the optical device with selective absorption and adjustable transmittance and the augmented reality device of the present invention, the optical device uses different phase delays for different wavelengths and cooperates with a polarizer to achieve a wavelength selective absorption function; the transmittance is adjusted by adjusting the angle of the transmission axis of the polarizer. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1A schematic diagram of an optical device with selective absorption and adjustable transmittance according to the present invention;

[0039] Figure 2 is a schematic diagram of an optical device with selective absorption and adjustable transmittance in an embodiment of the present invention;

[0040] Figure 3 Schematic diagram of transmittance and phase delay of light after passing through a 0.5 mm quartz crystal placed in the middle of parallel polarizers in an embodiment of the present invention;

[0041] Figure 4 A schematic diagram of an existing augmented reality display device.

[0042] [Description of Reference Numerals]

[0043] 23: first polarizer;

[0044] 22: First wave film;

[0045] 21: second polarizer;

[0046] 24: first type polarizer;

[0047] 42: second wave plate;

[0048] 41: The third polarizer. DETAILED DESCRIPTION

[0049] In order to better explain the present invention and facilitate understanding, the present invention is described in detail below through specific implementation modes in conjunction with the accompanying drawings.

[0050] In order to better understand the above technical solution, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a clearer and more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0051] See also Figure 1 This embodiment provides an optical device with selective absorption and adjustable transmittance, comprising:

[0052] A first light sheet assembly.

[0053] At least one first type polarizer 24 is disposed on the front side of the first optical sheet assembly.

[0054] The first type polarizer 24 is a polarizer that can be rotated relative to the first optical sheet assembly.

[0055] See also Figure 1 and Figure 2 At least one second optical sheet assembly is selectively disposed on the reverse side of the first optical sheet assembly.

[0056] The first optical sheet assembly includes: a first polarizer 23, a first wave plate 22, and a second polarizer 21 which are arranged sequentially and in parallel.

[0057] The first wave plate 22 is used to rotate the vibration direction of the light with a wavelength corresponding to the first wave plate after the light enters the first wave plate 22 .

[0058] Each of the second optical sheet assemblies includes a second wave plate 42 and a third polarizing plate 41 which are sequentially arranged in parallel.

[0059] The second wave plate 42 is used to rotate the vibration direction of the light with a wavelength corresponding to the second wave plate after the light enters the second wave plate.

[0060] In practical applications of this embodiment, in the first optical sheet assembly, the angle between the light transmission axis of the second polarizing sheet 21 and the optical axis of the first wave plate 22 is 45°.

[0061] In this embodiment, each of the first wave plate 22 and the second wave plate 42 is made of different materials; or, each of the first wave plate 22 and the second wave plate 42 is made of the same material and has different thicknesses.

[0062] The material of the wave plate in this embodiment can be selected from crystal wave plates, polymer wave plates, and liquid crystal wave plates.

[0063] The materials of the crystal wave plate in this embodiment include mica, calcite, and quartz.

[0064] The light transmission axis of the first polarizer 23 and the light transmission axis of the second polarizer 22 are 90° or 180°.

[0065] In practical applications of this embodiment, the first wave plate 22 realizes rotating the vibration direction of the light of the first specified wavelength corresponding to the first wave plate by 90° after the light enters the first wave plate.

[0066] In the actual application of this embodiment, the optical axis of the second wave plate 42 in each second optical plate assembly is 45° to the light transmission axis of the third polarizer 41; and the light transmission axis of the third polarizer 41 or the second polarizer 21 adjacent to the first side of each second wave plate 42 is 90° or 180° to the light transmission axis of the third polarizer 41 adjacent to the second side of the second wave plate 42.

[0067] In a specific application, when the optical device is not provided with a second optical sheet assembly, the optical device is as follows: Figure 2As shown, if the phase delay of the light of the wavelength corresponding to the first wave plate 22 is an even multiple of π, since the thickness of the first wave plate 22 is fixed, the phase delay of the light of other wavelengths is not an even multiple of π, or even an odd multiple of π / 2; the angle between the transmission axis of the second polarizer 21 and the optical axis of the wave plate 22 is 45°, when the light is incident from the side of the second polarizer 21:

[0068] 1) When the angle between the transmission axis of the first polarizer 23 and the transmission axis of the second polarizer 21 is 90°:

[0069] The light passes through the second polarizing plate 21 and becomes linearly polarized light whose vibration direction is consistent with the transmission axis direction of the second polarizing plate 21 .

[0070] For the light whose wavelength phase delay is an even multiple of π corresponding to the first wave plate 22 , the vibration direction remains unchanged after passing through the first wave plate 22 , and is perpendicular to the light transmission axis of the first polarizing plate 23 , and cannot pass through the first polarizing plate 23 .

[0071] For the light whose wavelength phase delay amount is an odd multiple of π corresponding to the first wave plate 22 , the vibration direction is rotated by 90° after passing through the first wave plate 22 , and is parallel to the transmission axis of the first polarizer 23 , and can pass through the first polarizer 23 .

[0072] 2) When the transmission axis of the first polarizer 23 is parallel to the transmission axis of the second polarizer 21:

[0073] The light passes through the second polarizing plate 21 and becomes linearly polarized light whose vibration direction is consistent with the transmission axis direction of the second polarizing plate 21 .

[0074] For a light ray with a specific wavelength whose phase delay is an even multiple of π, the vibration direction remains unchanged after passing through the first wave plate 22 , and the light ray is parallel to the light transmission axis of the first polarizer 23 , and can pass through the first polarizer 23 .

[0075] For the light whose wavelength phase delay corresponding to the first wave plate 22 is an odd multiple of π, the vibration direction is rotated by 90° after passing through the first wave plate 22, which is perpendicular to the light transmission axis of the first polarizer 23 and cannot pass through the first polarizer 23. Through the above steps, the optical device in this embodiment can achieve the performance of wavelength selective absorption.

[0076] In a specific application, when the optical device is not provided with a second optical sheet assembly, the optical device is as follows: Figure 2As shown, the first type polarizer 24 can be rotated relative to the first polarizer 23; when light is incident from one side of the first type polarizer 24, it first passes through the first type polarizer 24 and changes into a light transmission axis parallel to the first type polarizer 24; by rotating the first type polarizer 24, the angle of the vibration direction of the transmitted polarized light relative to the first polarizer 23 can be adjusted: when the angle is 90°, the light passing through the first type polarizer 24 cannot pass through the first polarizer 23; when the angle is 0°, the light passing through the first type polarizer 24 passes through the first polarizer 23, and after passing through the first polarizer 23:

[0077] a) When the angle between the transmission axis of the first polarizer 23 and the transmission axis of the second polarizer 21 is 90°:

[0078] The light passes through the first polarizing plate 23 and becomes linearly polarized light whose vibration direction is consistent with the transmission axis direction of the first polarizing plate 23 .

[0079] For the light whose wavelength phase delay is an even multiple of π corresponding to the first wave plate 22 , the vibration direction remains unchanged after passing through the first wave plate 22 , and is perpendicular to the light transmission axis of the second polarizer 21 , and cannot pass through the second polarizer 21 .

[0080] For the light whose wavelength phase delay is an odd multiple of π corresponding to the first wave plate 22 , the vibration direction is rotated by 90° after passing through the first wave plate 22 , and is parallel to the transmission axis of the second polarizer 21 , and can pass through the second polarizer 21 .

[0081] b) When the transmission axis of polarizer 23 is parallel to the transmission axis of polarizer 21:

[0082] The light passes through the first polarizing plate 23 and becomes linearly polarized light whose vibration direction is consistent with the transmission axis direction of the first polarizing plate 23 .

[0083] For the light whose wavelength phase delay is an even multiple of π corresponding to the first wave plate 22 , the vibration direction remains unchanged after passing through the first wave plate 22 , and is parallel to the light transmission axis of the first polarizer 23 , and can pass through the first polarizer 23 .

[0084] For the light whose wavelength phase delay is an odd multiple of π corresponding to the first wave plate 22, the vibration direction is rotated by 90° after passing through the first wave plate 22, which is perpendicular to the light transmission axis of the second polarizer 21 and cannot pass through the polarizer 23. In this way, the optical transposition proposed in this embodiment can achieve the adjustment of transmittance.

[0085] For example, when the transmission axis of the first polarizer 23 is parallel to the transmission axis of the second polarizer 21, the first wave plate 22 is a quartz crystal with a birefringence coefficient of about 0.00925 and a thickness of 0.5 mm; the transmittance and phase delay of the light after passing through the second polarizer 21, the first wave plate 22 and the first polarizer 23 are as follows: Figure 3As shown, wavelengths with a phase delay of even multiples of π (such as 510nm, 9λ=18π) corresponding to the first wave plate 22 can be completely transmitted, and wavelengths with a phase delay of odd multiples of π (such as 540nm, 17λ / 2=17π) cannot be transmitted, thereby achieving wavelength selective absorption performance.

[0086] In order to achieve a wider wavelength absorption range or a better absorption effect in this embodiment, multiple wave plates and polarizers can be used, and the wave plates and polarizers are placed alternately, and the wave plates have different phase delays for the same wavelength (wave plates of different materials or wave plates of different thicknesses are used). Figure 1 As shown: the optical axes of the second polarizer 21, the first polarizer 23 and the third polarizer 41 are parallel, and the angle between the light transmission axis of the third polarizer 41 and the optical axis of the second wave plate 42 is 45°. The phase delay of the first wave plate 22 is set by the wavelength of the third polarizer 41, the second wave plate 42 and the second polarizer 21, so that the phase delay is an odd multiple of π when passing through the first wave plate 22, and the vibration direction is rotated 90° perpendicular to the first polarizer 23, and cannot pass through, thereby increasing the absorption range of the wavelength.

[0087] In practical applications of this embodiment, each wave plate in the first wave plate 22 and the second wave plate 42 corresponds to light of different wavelengths.

[0088] In practical applications of this embodiment, both the first wave plate 22 and the second wave plate 42 are multi-order wave plates.

[0089] The selective absorption and transmittance adjustable optical device and augmented reality device of this embodiment, the optical device uses different phase delays for different wavelengths and cooperates with a polarizer to achieve a wavelength selective absorption function; the transmittance is adjusted by adjusting the angle of the transmission axis of the polarizer.

[0090] This embodiment also provides an augmented reality display device, comprising any of the above-mentioned selective absorption and transmittance-adjustable optical devices.

[0091] In a specific embodiment, the selectively absorbing and transmittance-adjustable optical device is disposed on the outward side of the optical combiner of the augmented reality display device to prevent the light emitted outward from the optical combiner from being seen by people.

[0092] In the description of the present invention, it should be understood that 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. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0093] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0094] In the present invention, unless otherwise clearly specified and limited, when a first feature is “on” or “below” a second feature, it may be that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, when a first feature is “above”, “above” or “above” a second feature, it may be that the first feature is directly above or obliquely above the second feature, or it may simply mean that the first feature is higher in level than the second feature. When a first feature is “below”, “below” or “below” a second feature, it may be that the first feature is directly below or obliquely below the second feature, or it may simply mean that the first feature is lower in level than the second feature.

[0095] In the description of this specification, the description of the terms "one embodiment", "some embodiments", "embodiment", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0096] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may alter, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. An augmented reality display device, characterized in that: A selectively absorbing and transmittance-adjustable optical device is provided on an outward side of a light combiner of the augmented reality display device; The optical device with selective absorption and adjustable transmittance comprises: a first light sheet assembly; At least one first type polarizing sheet (24) is arranged on the front side of the first optical sheet assembly; The first type of polarizer (24) is a polarizer that can rotate relative to the first optical sheet assembly; At least one second optical sheet assembly is selectively disposed on the reverse side of the first optical sheet assembly; The first optical sheet assembly comprises: a first polarizing sheet (23), a first wave plate (22), and a second polarizing sheet (21) which are arranged sequentially and in parallel; In the first optical sheet assembly, the angle between the light transmission axis of the second polarizing sheet (21) and the optical axis of the first wave plate (22) is 45°; The light transmission axis of the first polarizer (23) and the light transmission axis of the second polarizer (22) are at 90° or 180°; The first wave plate (22) realizes rotating the vibration direction of the light of the first specified wavelength corresponding to the first wave plate by 90° after the light enters the first wave plate; Each of the second optical sheet assemblies comprises a second wave plate (42) and a third polarizing plate (41) which are sequentially arranged in parallel; The optical axis of the second wave plate (42) in each second optical plate assembly is 45° to the light transmission axis of the third polarizing plate (41); and the light transmission axis of the second polarizing plate (21) adjacent to the first side surface of each second wave plate (42) is 90° or 180° to the light transmission axis of the third polarizing plate (41) adjacent to the second side surface of the second wave plate (42); The second wave plate (42) is used to rotate the vibration direction of the light with a wavelength corresponding to the second wave plate after the light enters the second wave plate; Each of the first wave plate (22) and the second wave plate (42) is made of different materials; or, The materials of each wave plate in the first wave plate (22) and the second wave plate (42) are the same and the thicknesses are different.

2. The augmented reality display device according to claim 1, characterized in that: Each wave plate in the first wave plate (22) and the second wave plate (42) corresponds to light of different wavelengths one by one.

3. The augmented reality display device according to claim 2, characterized in that: The first wave plate (22) and the second wave plate (42) are both multi-order wave plates; The material of the wave plate can be selected from crystal wave plates, polymer wave plates, and liquid crystal wave plates.

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