Holographic optical waveguide, sighting device and ar device

Abstract

A holographic optical waveguide, a sighting device and an AR device. By means of using a holographic waveguide plate (5) to change the propagation path of light, the optical path effect of a reflex sighting device is achieved while avoiding the problems of large volume and weight or poor target display effect of the reflex sighting device, and advantages such as small size, light weight and a good display effect are achieved; the area of a coupled-in image incident on the holographic waveguide plate (5) is consistent with that of a coupled-out image emitted from the holographic waveguide plate (5), thus making the holographic waveguide plate (5) a non-pupil-expanding holographic waveguide plate (5); the coupled-in image does not need to be replicated within the holographic optical waveguide, i.e., the area of the coupled-in image is consistent with that of the coupled-out image, thus reducing the optical efficiency loss caused by image replication; moreover, the sizes of a coupling-in region and a coupling-out region are the same and both are larger than a preset size, and thus the non-pupil-expanding holographic optical waveguide also has a large exit-pupil effect, thereby achieving a high-quality coupled-out image, low optical efficiency loss and an excellent viewing experience.

Description

A holographic waveguide, a sight, and an AR device

[0001] This application claims priority to Chinese Patent Application No. 202422514265.5, filed on October 17, 2024, entitled "A Holographic Waveguide, a Sight and an AR Device", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of optical technology, and in particular to a holographic waveguide, a sight, and an AR device. Background Technology

[0003] Reflex sight systems are widely used in outdoor applications, and the main types of reflex sights are red dot sights and holographic sights.

[0004] Red dot sights project an image by reflecting a point light source to infinity using a mirror. Their advantages include simplicity, low cost, and small size. However, they have disadvantages such as a relatively small field of view, and chromatic aberration and aiming errors that occur when the eye moves to the edge of the scope, affecting aiming accuracy. Holographic sights, on the other hand, use collimated laser light incident on a hologram to reconstruct an image of a target at infinity. Their advantages include no eye-to-scope distance requirement, high stability, and no chromatic aberration. However, they are more expensive, have a more complex structure, and are larger. Therefore, both red dot and holographic sights have certain drawbacks that affect their usability. Furthermore, waveguides with pupil-expanding functions typically replicate the emitted light to widen the field of view, resulting in lower beam energy reaching the eye and impacting the visual experience.

[0005] Therefore, providing a small-sized aiming scope with good display effect is a technical problem that urgently needs to be solved by those in the field.

[0006] Summary of the Invention

[0007] The purpose of this application is to provide a holographic waveguide, a sight, and an AR device to solve the technical problems of existing reflective sights, such as large size and poor display effect.

[0008] To address the aforementioned technical problems, this application provides a holographic waveguide, comprising a holographic waveguide sheet, wherein coupling-in region and coupling-out region are respectively provided at both ends of the holographic waveguide sheet; the size of both the coupling-in region and the coupling-out region is larger than a preset size; and the size of the coupling-in region and the coupling-out region is the same, or the size difference between the coupling-in region and the coupling-out region is less than a preset threshold.

[0009] The coupling region is used to receive the first parallel beam and cause the first parallel beam to change its transmission direction and then undergo total internal reflection transmission in the holographic waveguide; the coupling region is used to receive the beam after total internal reflection transmission and cause the beam to change its transmission direction to form a second parallel beam for emission.

[0010] The area of ​​the incident image on the holographic waveguide is the same as the area of ​​the detached image from the holographic waveguide.

[0011] For example, the dimensions of both the coupling-in region and the coupling-out region are larger than a preset size, specifically: the sum of the areas of the coupling-in region and the coupling-out region is greater than 70% of the area of ​​the holographic waveguide sheet.

[0012] For example, a hologram is provided on the light-emitting side of the coupling region, and the hologram is located on the transmission path of the second parallel beam.

[0013] For example, the hologram is attached to the holographic waveguide sheet by means of imprinting, etching, masking or exposure and development.

[0014] To solve the above-mentioned technical problems, this application provides a sight, including: a light source, a collimating element, and the above-mentioned holographic waveguide;

[0015] The light source is located on one side of the coupling region of the holographic waveguide and is used to emit a light beam;

[0016] The collimating element is disposed between the light source and the holographic waveguide, and is used to collimate the light beam emitted by the light source to form the first parallel light beam and transmit it to the holographic waveguide.

[0017] The holographic waveguide is used to change the transmission direction of the first parallel beam and transmit it through total internal reflection, forming the second parallel beam that is emitted to the human eye.

[0018] For example, when the light source includes a laser light source, the wavelength of the laser light source is the same as the wavelength of the reference light used to prepare the hologram.

[0019] For example, the light source is a single light source, and the coupling region is also disposed in the white light path. The white light and the single light source are emitted to the human eye after being diffracted by the coupling region.

[0020] For example, the coupling region is also disposed in the white light path, and the transmission direction of the second parallel beam is consistent with the transmission direction of the white light after entering the scope. After being diffracted by the coupling region, the white light and the second parallel beam formed based on the light source are emitted together to the human eye.

[0021] For example, the coupling region and the hologram are also arranged in the white light path, and the transmission direction of the second parallel beam is consistent with the transmission direction of the white light after entering the scope. After being diffracted by the coupling region, the white light is transmitted to the hologram together with the second parallel beam formed based on the light source, and finally exits to the human eye.

[0022] For example, the light source is a single light source; or, the light source includes a first light source and a second light source, and a beam combining element is provided in the optical path between the light source and the collimating element, so that the beam emitted by the first light source and the beam emitted by the second light source are combined by the beam combining element and transmitted to the collimating element.

[0023] For example, the first light source and the second light source are light sources of the same type or different types; wherein, the light source type includes at least point light source type, image source type and laser light source type.

[0024] For example, the light combining element is a semi-transparent and semi-reflective mirror; the first light source and the second light source are respectively located on both sides of the semi-transparent and semi-reflective mirror, and the semi-transparent and semi-reflective mirror is placed at 45° relative to the center line of the light beam emitted by the first light source, and the semi-transparent and semi-reflective mirror is placed at 45° relative to the center line of the light beam emitted by the second light source.

[0025] To address the aforementioned technical problems, this application also provides an AR device, including the aforementioned holographic waveguide or sight.

[0026] The holographic waveguide provided in this application includes a holographic waveguide sheet. The two ends of the holographic waveguide sheet are respectively provided with a coupling-in region and a coupling-out region. The coupling-in region is used to receive a first parallel beam and cause the first parallel beam to change its transmission direction and then undergo total internal reflection transmission in the holographic waveguide sheet. The coupling-out region is used to receive the beam after total internal reflection transmission and cause the beam to change its transmission direction to form a second parallel beam that is emitted. By utilizing a holographic waveguide to alter the propagation path of light, the optical path effect of a reflective sight is achieved, while avoiding the problems of large size and weight or poor target display in reflective sights. It boasts advantages such as small size, light weight, and excellent display quality. Furthermore, the area of ​​the incident image on the holographic waveguide is the same as the area of ​​the image ejected from it, making this a non-pupil-expanding holographic waveguide. The incident image does not need to be replicated within the holographic waveguide; that is, the area of ​​the incident image is the same as the area of ​​the ejected image, reducing the light efficiency loss caused by image replication. Simultaneously, the size of the incident and ejected areas are the same and both larger than a preset size, giving this non-pupil-expanding holographic waveguide a large exit pupil effect, high-quality ejected image, minimal light efficiency loss, and a superior observation experience. Moreover, the beam undergoes total internal reflection within the holographic waveguide, avoiding transmission and further reducing light loss, increasing the amount of light entering the eye, and greatly enhancing the user experience.

[0027] In addition, this application also provides a sight that includes the aforementioned holographic waveguide, which has the same or corresponding technical features as the aforementioned holographic waveguide and has the same effect.

[0028] In addition, this application also provides an AR device, including the aforementioned holographic waveguide or aiming scope, which has the same or corresponding technical features as the aforementioned holographic waveguide or aiming scope, and has the same effect. Attached Figure Description

[0029] To more clearly illustrate the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 is a schematic diagram of a holographic optical waveguide provided in an embodiment of this application;

[0031] Figure 2 is a schematic diagram of a holographic waveguide sheet provided in an embodiment of this application;

[0032] Figure 3 is a schematic diagram of a sight provided in the first embodiment of this application;

[0033] Figure 4 is a schematic diagram of a sight provided in the second embodiment of this application;

[0034] Figure 5 is a schematic diagram of a sight provided in the third embodiment of this application.

[0035] The attached figures are labeled as follows:

[0036] 1-First light source; 2-Second light source; 3-Synthesizing element; 4-Collimating element; 5-Holographic waveguide sheet; 6-Human eye; 7-Holographic photograph. Detailed Implementation

[0037] 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 of ordinary skill in the art without creative effort are within the protection scope of this application.

[0038] The core of this application is to provide a holographic waveguide, a sight, and an AR device to solve the technical problems of existing reflective sights, such as large size and poor display effect.

[0039] To enable those skilled in the art to better understand the present application, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments. Figure 1 is a schematic diagram of a holographic optical waveguide provided in an embodiment of the present application. As shown in Figure 1, it includes a holographic waveguide sheet 5, and coupling-in region and coupling-out region are respectively provided at both ends of the holographic waveguide sheet 5; the size of the coupling-in region and the coupling-out region are both larger than a preset size; and the size of the coupling-in region and the coupling-out region are the same, or the size difference between the coupling-in region and the coupling-out region is less than a preset threshold.

[0040] The coupling region is used to receive the first parallel beam and cause the first parallel beam to change its transmission direction and then undergo total internal reflection transmission in the holographic waveguide 5; the coupling region is used to receive the beam after total internal reflection transmission and cause the beam to change its transmission direction to form a second parallel beam for emission.

[0041] The area of ​​the incident image on the holographic waveguide 5 is the same as the area of ​​the image that is detached from the holographic waveguide 5.

[0042] To ensure the amount of light received by the human eye 6 after passing through the waveguide sheet, the holographic waveguide provided in this application has the same area of ​​the coupled-in image incident on the holographic waveguide sheet 5 and the area of ​​the coupled-out image from the holographic waveguide sheet 5, thus having the function of not dilating the pupil. Figure 2 is a schematic diagram of a holographic waveguide sheet provided in an embodiment of this application. As shown in Figure 2, a coupled-in region and a coupled-out region are set in the holographic waveguide sheet 5. The holographic gratings in the coupled-in region and the coupled-out region have the advantages of being lightweight and thin, and having high diffraction efficiency. According to the grating equation mλ=d(sinα±sinβ), the diffraction angle β is the direction of light propagation after passing through the grating, where the diffraction wavelength (λ) is a constant. By adjusting the grating order (m), the incident angle (α), and the grating constant (d), the beam can be modulated, that is, the beam after passing through the grating can be made to propagate in a specified direction. The dimensions of the insertion and extraction regions are not limited; they can be the same, or the difference between them can be less than a preset threshold. It is worth noting that the preset threshold is a value close to 0. Preferably, the size of the insertion region is equal to the size of the extraction region. By setting the area of ​​the inserted image incident on the holographic waveguide to be consistent with the area of ​​the extracted image exiting the holographic waveguide, i.e., the areas of the inserted and extracted images are equal or similar, this makes the holographic waveguide a non-pupil-expanding holographic waveguide. Simultaneously, setting the dimensions of the insertion and extraction regions to be the same ensures high image quality and minimal light loss for both insertion and extraction via this non-pupil-expanding holographic waveguide. Furthermore, setting the dimensions of both the insertion and extraction regions to be larger than a preset size, i.e., the sum of the areas of the insertion and extraction regions is greater than 70% of the area of ​​the holographic waveguide, gives this holographic waveguide a large exit pupil effect. As can be seen, the holographic waveguide provided in this embodiment is a non-pupil holographic waveguide. The coupled image does not need to be copied within the holographic waveguide, that is, the area of ​​the coupled image is the same as the area of ​​the coupled image, which reduces the light effect loss caused by image copying. At the same time, the coupled and coupled regions are the same size and both are larger than the preset size, so that this non-pupil holographic waveguide has a large exit pupil effect, high quality of coupled image, small light effect loss, and good observation experience.

[0043] The coupling region is used to receive the first parallel beam and cause the first parallel beam to change its transmission direction and then undergo total internal reflection transmission in the holographic waveguide 5; the coupling region is used to receive the beam after total internal reflection transmission and cause the beam to change its transmission direction to form a second parallel beam for emission.

[0044] In implementation, a hologram 7 is disposed on the light-emitting side of the coupling region of the holographic waveguide; the hologram 7 is located on the transmission path of the second parallel beam. The hologram 7 can be placed at a distance from the holographic waveguide 5, or it can be attached to the holographic waveguide 5 by imprinting, etching, masking, or exposure and development. To reduce the system size, it can be attached to the holographic waveguide 5 by imprinting, etching, masking, or exposure and development.

[0045] The holographic waveguide provided in this application includes a holographic waveguide sheet 5. The two ends of the holographic waveguide sheet 5 are respectively provided with a coupling-in region and a coupling-out region. The coupling-in region is used to receive a first parallel beam and to make the first parallel beam change its transmission direction and then undergo total internal reflection transmission in the holographic waveguide sheet 5. The coupling-out region is used to receive the beam after total internal reflection transmission and to make the beam change its transmission direction to form a second parallel beam that is emitted. By using the holographic waveguide 5 to change the propagation path of light, the optical path effect of a reflective sight is achieved, while avoiding the problems of large size and weight or poor target display of reflective sights. It has the advantages of small size, light weight and good display effect. Moreover, the area of ​​the incident image on the holographic waveguide 5 is the same as the area of ​​the image ejected from the holographic waveguide 5, and the size of both the incident and ejected areas is larger than the preset size. The size of the incident and ejected areas is the same, or the size difference between the incident and ejected areas is less than the preset threshold, achieving the effect of no pupil dilation and a large exit pupil, reducing light loss and increasing the amount of light entering the human eye. Furthermore, the beam is transmitted by total internal reflection in the holographic waveguide 5, avoiding transmission, further reducing light loss and increasing the amount of light entering the human eye 6, greatly improving the user experience.

[0046] The above describes a holographic waveguide. This embodiment also provides a sight, including: a light source, a collimating element 4, and the above-described holographic waveguide;

[0047] The light source is located on one side of the coupling region of the holographic waveguide 5 to emit a light beam;

[0048] The collimating element 4 is disposed between the light source and the holographic waveguide 5, and is used to collimate the light beam emitted by the light source to form a first parallel light beam and transmit it to the holographic waveguide 5.

[0049] The holographic waveguide 5 is used to change the transmission direction of the first parallel beam and transmit it through total internal reflection, forming a second parallel beam that is emitted to the human eye 6.

[0050] There are no limitations on the light source; it can be a single light source or multiple light sources. Specifically, the light source can be a laser light source, but is not limited to a laser light source, and can also be a light-emitting diode (LED) light source, a display screen light source, a light source with a reticle pattern, or a display screen light source with digital images. When the light source is a microdisplay, the microdisplay can carry long-infrared thermal imaging information, mid-wave infrared information, short-wave infrared information, near-infrared night vision imaging information, or various other electronic imaging information. When multiple light sources are used, there are no limitations on the number of light sources. For example, the light source includes a first light source 1 and a second light source 2. In this case, the pupil expansion system also includes a light combining element 3; the light combining element 3 is located in the optical path between the light source and the collimating element 4. The first light source 1 and the second light source 2 are light sources of the same type or different types; among them, the light source type includes at least a point light source type and an image source type. The light combining element 3 can be a semi-transparent and semi-reflective mirror. The first light source 1 and the second light source 2 are located on opposite sides of the semi-transparent mirror, and the semi-transparent mirror is placed at a 45° angle relative to the center line of the beam emitted by the first light source 1, and the semi-transparent mirror is placed at a 45° angle relative to the center line of the beam emitted by the second light source 2.

[0051] The collimating element 4 used is not limited, as long as it can convert the light beam emitted by the light source into parallel light. For example, the collimating element 4 can be a single lens, a combination of lenses, or a curved mirror.

[0052] The position of the holographic waveguide 5 relative to the first parallel beam is not limited. The holographic waveguide 5 can be placed vertically or tilted relative to the first parallel beam.

[0053] Taking a multi-source light source (including a first source 1 and a second source 2) as an example, the aiming scope provided in the embodiments of this application will be described. Figure 3 is a schematic diagram of an aiming scope provided in the first embodiment of this application. As shown in Figure 3, the aiming scope includes: a beam combining element 3, a collimating element 4, and a holographic waveguide 5, which are placed sequentially along the transmission direction of the light beam emitted by the light source; the light source includes a first source 1 and a second source 2; wherein, the first source 1 is an image source;

[0054] The light combining element 3 is used to combine the light of the first light source 1 and the second light source 2.

[0055] Collimating element 4 is used to collimate the light beam after passing through beam combining element 3;

[0056] The coupling region in the holographic waveguide 5 is used to receive the first parallel beam after it has been collimated by the collimating element 4, and to change the transmission direction of the first parallel beam so that the beam after passing through the coupling region can be transmitted by total internal reflection inside the holographic waveguide 5.

[0057] The coupling region in the holographic waveguide 5 is used to receive the light beam after total internal reflection and change the transmission direction of the light beam after total internal reflection to form a second parallel light, which is then introduced into the human eye 6; wherein, the coupling region is a semi-transparent medium.

[0058] In the schematic diagram of the aiming scope provided in Figure 3, the first light source 1 is an image source, such as a miniature display screen, used to display images formed by different channels or other information that needs to be displayed; the second light source 2 is a point light source used to form a red dot target at infinity; the light combining element 3 is a semi-transparent and semi-reflective mirror, which is at 45° to the optical axis of the principal rays emitted from the miniature display screen and the point light source, used to deflect the light emitted from the miniature display screen so that it merges with the beam emitted from the point light source. Collimating element 4 receives the light beams emitted from the point light source and the microdisplay, corrects their internal aberrations, and emits parallel light into the holographic waveguide 5. The holographic waveguide 5 is placed perpendicular to the centerline of the beam collimated by collimating element 4. The coupling region of the holographic waveguide 5 receives the collimated light, and the holographic grating in this region changes the propagation direction of the incident collimated light, causing it to propagate towards the interior of the waveguide through total internal reflection. After reaching the coupling region, the light is again redirected by the holographic light in the coupling region, propagating towards the human eye 6. Since the coupling region is a semi-transparent medium, light from the external scene can directly pass through it. The human eye 6 receives the combined light from the red dot light source, the microdisplay, and the external scene.

[0059] In Figure 3, the holographic waveguide 5 is placed perpendicular to the first parallel beam. Figure 4 is a schematic diagram of a sight provided in the second embodiment of this application. Comparing the schematic diagrams of the sights provided in Figure 3 and Figure 4, it can be seen that the difference between Figure 3 and Figure 4 is that the holographic waveguide 5 in Figure 4 is placed at an angle relative to the first parallel beam. According to the grating equation, when the holographic waveguide 5 is placed at an angle, the energy of the diffracted light rays in the diffraction angle β is more concentrated, which is beneficial to increasing the light energy utilization rate.

[0060] It is worth noting that the information observed by the human eye 6 will differ depending on the light source used when using this scope. When a single light source is used, the scope is a single-source, non-pupil-expanding system. Taking a red dot light source as an example, after the red dot light source emits a beam, the collimating element collimates the beam to form a first parallel beam, which is then transmitted to the holographic waveguide 5. The holographic waveguide 5 changes the transmission direction of the first parallel beam, causing it to undergo total internal reflection and form a second parallel beam that exits to the human eye 6. At this point, the human eye 6 obtains the red dot information.

[0061] In order to enable users to see more information through the scope, the coupling area is also set in the white light path, and the transmission direction of the second parallel beam is consistent with the transmission direction of the white light after entering the scope. After the white light is diffracted by the coupling area, it is emitted to the human eye together with the second parallel beam formed based on the light source.

[0062] Specifically, in addition to using a single light source, the coupling area is also set in the white light path. The white light and the single light source are diffracted by the coupling area and then emitted to the human eye 6. That is, the scope is a dual-light non-pupil system composed of white light and a single light source. When the single light source used is a red dot light source, the human eye 6 can see the real scene in the white light direct path at the same time as seeing the red dot information.

[0063] When multiple light sources are used, this pupil-expanding system is also called a multi-source non-pupil-expanding system. For example, if the light sources include a first light source 1 and a second light source 2, a dual-source non-pupil-expanding system consisting of the first light source 1 and the second light source 2 is formed. Furthermore, based on the use of multiple light sources, the coupling region can also be placed in the white light path, thus forming a multi-light non-pupil-expanding system consisting of white light and multiple light sources. For example, if white light and the first light source 1 and the second light source 2 are diffracted through the coupling region and then emitted to the human eye 6, a three-light fusion non-pupil-expanding system consisting of white light, the first light source 1, and the second light source 2 is formed.

[0064] In practice, the scope includes a hologram 7, which is located on the transmission path of the second parallel beam. It is noteworthy that when the light source includes a laser source, the wavelength of the laser source is the same as the wavelength of the reference light used to prepare the hologram 7, ensuring that the reticle information on the hologram 7 can be seen.

[0065] To allow users to see more information through the sight, the coupling region and hologram 7 are also positioned in the white light path, and the transmission direction of the second parallel beam is consistent with the transmission direction of the white light after entering the sight. After diffraction in the coupling region, the white light is transmitted together with the second parallel beam formed based on the light source to the hologram 7, and finally exits to the human eye 6. Figure 5 is a schematic diagram of a sight provided in the third embodiment of this application. As can be seen from Figure 4, a hologram 7 is added to the coupling region in Figure 5. When the hologram 7 is used in conjunction with the holographic waveguide 5, various preset target patterns can be generated when laser light shines into the hologram 7. The green or red film in the hologram 7 can make the target display different colors, improving the user experience.

[0066] In the schematic diagram of the aiming scope provided in Figure 5, the first light source 1 is an image source, such as a miniature display screen, used to display images formed by different channels or other information that needs to be displayed; the second light source 2 is a laser light source used to illuminate the hologram 7 to form a target at infinity; the light combining element 3 is a semi-transparent and semi-reflective mirror, which is at 45° to the principal ray optical axis of the laser light source and the miniature display screen, used to deflect the light emitted by the miniature display screen so that it merges with the light emitted by the laser light source; the collimating element 4 is used to receive the light emitted by the laser light source and the miniature display screen, correct their internal aberrations, and emit parallel light into the holographic waveguide 5; the coupling area of ​​the holographic waveguide 5... The collimated light beam is received, and the holographic grating in this area changes the propagation direction of the incident collimated light beam, causing the light to propagate towards the interior of the waveguide sheet through total internal reflection. After the light beam reaches the coupling area, its propagation direction is changed again by the holographic light in the coupling area, causing it to propagate towards the human eye 6. Since the coupling area is a semi-transparent medium, light from the external scene can directly pass through the coupling area to propagate. After the laser light source illuminates the hologram 7 through the coupling area, it forms a preset target at infinity. The red or green film on the hologram 7 can make the target display different colors, allowing the user to customize the shape and color of the target. The human eye 6 is used to receive the fused light from the target, the micro-display, and the external scene.

[0067] It is worth noting that the information observed by the human eye 6 will differ depending on the light source used when using the scope containing the hologram 7. When a single light source is used, the scope is a single-source, non-pupil-expanding system. Taking a laser light source as an example, after the laser light source emits a beam, the collimating element 4 collimates the beam into parallel light that is incident on the coupling region. The coupling region receives the incident beam and then incident it as parallel light onto the hologram 7, allowing the human eye 6 to obtain the reticle information recorded on the hologram 7. To allow the user to see more information through the scope, in addition to using a single light source, the coupling region is also placed in the white light path. That is, the scope is a dual-light, non-pupil-expanding system composed of white light and a single light source. When a laser light source is used, the human eye 6 can see the reticle information recorded on the hologram 7 while also seeing the real scene in the white light direct path.

[0068] When multiple light sources are used, this sight is also called a multi-source non-pupil system. For example, using a first light source 1 and a second light source 2 forms a dual-light non-pupil system composed of the first light source 1 and the second light source 2. Furthermore, by using multiple light sources and placing the coupling area in the white light path, a multi-light non-pupil system composed of white light and multiple light sources is formed. For instance, a three-light fusion non-pupil system composed of white light, the first light source 1, and the second light source 2 is formed. When the first light source 1 is a laser source and the second light source 2 is an image source, this sight allows the user to see holographic reticle information and image source information without obstructing the white light direct path, allowing them to see the actual scene within the white light direct path. In other words, this sight ensures sufficient light intake for the user's eye 6, enabling accurate observation of multi-channel images.

[0069] The aiming scope provided in this application embodiment achieves the optical path effect of a reflective aiming scope by changing the propagation path of the light beam using a holographic waveguide 5. This avoids the problems of large size and weight or poor target display in reflective aiming scopes, offering advantages such as small size, light weight, and good display effect. Furthermore, the area of ​​the incident image on the holographic waveguide 5 is the same as the area of ​​the image ejected from the holographic waveguide 5, making this a non-pupil-expanding holographic waveguide 5. The incident image does not need to be replicated within the holographic waveguide, meaning the area of ​​the incident image is the same as the area of ​​the ejected image, reducing the light effect loss caused by image replication. Simultaneously, the size of the incident and ejected areas are the same and both larger than a preset size, giving this non-pupil-expanding holographic waveguide a large exit pupil effect, high-quality ejected image, low light effect loss, and a superior observation experience. Moreover, the light beam is transmitted via total internal reflection in the holographic waveguide 5, avoiding transmission and further reducing light loss, increasing the amount of light entering the human eye 6, and greatly enhancing the user experience. This system combines the advantages of a red dot sight (small size and light weight) with the advantages of a holographic sight (clear target with no color difference and high stability), greatly enhancing the user experience.

[0070] The foregoing description includes a holographic waveguide and a sight. This application also provides an augmented reality (AR) device, including the aforementioned holographic waveguide or sight. The AR device provided in this embodiment has the same or corresponding technical features as the holographic waveguide or sight described above. The embodiments of the holographic waveguide and sight have been described in detail above; therefore, the embodiments of the AR device will not be repeated here, as the effects are the same.

[0071] The foregoing has provided a detailed description of a holographic waveguide, a sight, and an AR device provided in this application. The various embodiments in the specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. It should be noted that those skilled in the art can make various improvements and modifications to this application without departing from its principles, and these improvements and modifications also fall within the protection scope of this application.

[0072] It should also be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

Claims

1. A holographic optical waveguide, characterized in that, The holographic waveguide (5) includes a coupling-in region and a coupling-out region at both ends of the holographic waveguide (5); the size of the coupling-in region and the coupling-out region are both larger than a preset size; and the size of the coupling-in region and the coupling-out region are the same, or the size difference between the coupling-in region and the coupling-out region is less than a preset threshold. The coupling region is used to receive the first parallel beam and to make the first parallel beam change its transmission direction and then undergo total internal reflection transmission in the holographic waveguide (5); the coupling region is used to receive the beam after total internal reflection transmission and to make the beam change its transmission direction to form a second parallel beam for emission. The area of ​​the incident image on the holographic waveguide (5) is the same as the area of ​​the image detached from the holographic waveguide (5).

2. A holographic optical waveguide according to claim 1, characterized in that, The dimensions of both the coupling-in region and the coupling-out region are larger than the preset dimensions, specifically: the sum of the areas of the coupling-in region and the coupling-out region is greater than 70% of the area of ​​the holographic waveguide (5).

3. A holographic optical waveguide according to claim 1, characterized in that, A hologram (7) is provided on the light-emitting side of the coupling region, and the hologram (7) is located on the transmission path of the second parallel beam.

4. A holographic optical waveguide according to claim 3, characterized in that, The holographic photograph (7) is attached to the holographic waveguide sheet (5) by means of imprinting, etching, masking or exposure and development.

5. A sight, characterized in that, include: A light source, a collimating element (4), and a holographic waveguide as described in any one of claims 1 to 4; The light source is located on one side of the coupling region of the holographic waveguide and is used to emit a light beam; The collimating element (4) is disposed between the light source and the holographic waveguide, and is used to collimate the light beam emitted by the light source to form the first parallel light beam and transmit it to the holographic waveguide. The holographic waveguide is used to change the transmission direction of the first parallel beam and transmit it through total internal reflection, and to form the second parallel beam that is emitted to the human eye (6).

6. The aiming scope according to claim 5, characterized in that, When the light source includes a laser light source, the wavelength of the laser light source is the same as the wavelength of the reference light used to prepare the hologram (7).

7. The aiming scope according to claim 5, characterized in that, The coupling region is also set in the white light path, and the transmission direction of the second parallel beam is consistent with the transmission direction of the white light after entering the aiming scope. After the white light is diffracted by the coupling region, it is emitted to the human eye together with the second parallel beam formed based on the light source (6).

8. The aiming scope according to claim 5, characterized in that, The coupling region and the hologram (7) are also set in the white light path, and the transmission direction of the second parallel beam is consistent with the transmission direction of the white light after entering the scope. After the white light is diffracted by the coupling region, it is transmitted to the hologram (7) together with the second parallel beam formed based on the light source, and finally exits to the human eye (6).

9. The sight according to any one of claims 5 to 8, characterized in that, The light source is a single light source; or, the light source includes a first light source (1) and a second light source (2), and a beam combining element (3) is provided in the optical path between the light source and the collimating element (4). The beam emitted by the first light source (1) and the beam emitted by the second light source (2) are combined by the beam combining element (3) and then transmitted to the collimating element (4).

10. The sight according to claim 9, characterized in that, The first light source (1) and the second light source (2) are light sources of the same type or different types; wherein, the light source type includes at least point light source type, image source type and laser light source type.

11. The aiming scope according to claim 9, characterized in that, The light combining element (3) is a semi-transparent and semi-reflective mirror; the first light source (1) and the second light source (2) are located on both sides of the semi-transparent and semi-reflective mirror, and the semi-transparent and semi-reflective mirror is placed at 45° relative to the center line of the light beam emitted by the first light source (1), and the semi-transparent and semi-reflective mirror is placed at 45° relative to the center line of the light beam emitted by the second light source (2).

12. An AR device, characterized in that, It includes the holographic waveguide as described in any one of claims 1 to 4, or the aiming scope as described in any one of claims 5 to 11.

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