Pupil expansion system and display device

Abstract

A pupil expansion system and a display device, relating to the technical field of optics. Provided is a pupil expansion system, comprising a light source, a reflective grating, and a beam shaping element. First, pupil expansion of a beam is implemented by using the reflective grating, so that a user can observe image information in a wider range. In addition, compared with a function of pupil expansion by means of an optical waveguide, there is no process of coupling in and out when using the reflective grating, which reduces energy loss, improves the energy utilization rate, and improves the experience of a user when using a device comprising the pupil expansion system. Second, the beam shaping element is located on an incident light path and / or an emergent light path of the reflective grating, for beam shaping. The beam shaping element performs beam shaping and, in combination with a pupil expansion function of the reflective grating, enables a human eye to receive a circular beam, thereby improving the visual experience of the user.

Description

A pupil expansion system and display device

[0001] This application claims priority to Chinese Patent Application No. 202422514261.7, filed on October 17, 2024, entitled "A Pupil Expansion System and Display Device", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This utility model relates to the field of optical technology, and in particular to a pupil expansion system and a display device. Background Technology

[0003] Currently, the pupil-expanding function of most optical products on the market is achieved through optical waveguide technology. By setting coupling-in and coupling-out gratings on the optical waveguide lens, light enters the optical waveguide lens after being coupled in through the coupling-in grating. In the glass substrate, the light is transmitted to the coupling-out grating of the optical waveguide through the principle of total internal reflection. After being expanded by the coupling-out grating, the light exits, thus increasing the exit pupil diameter. Optical waveguide lenses have advantages such as expanding the range of eye movement and reducing system size.

[0004] However, due to the principle of optical waveguide imaging, energy loss during transmission is unavoidable for both the input and output gratings, resulting in low optical energy utilization efficiency.

[0005] Therefore, providing a new pupil dilation technology to improve energy utilization and enhance user experience is a technical problem that urgently needs to be solved by those in this field. Summary of the Invention

[0006] The purpose of this invention is to provide a pupil expansion system and display device to solve the technical problem of low energy utilization in pupil expansion systems, which affects the user experience.

[0007] To solve the above-mentioned technical problems, this utility model provides a pupil expansion system, including: a light source, a reflective grating, and a beam shaping element; the light source is used to emit a light beam;

[0008] The light beam emitted by the light source is obliquely incident on the reflective grating, and exits after being dilated by the reflective grating;

[0009] The beam shaping element is located on the incident and / or outgoing optical paths of the reflective grating and is used for beam shaping.

[0010] Exemplarily, it also includes a collimation system; the collimation system is disposed between the light source and the reflective grating, and is used to collimate the light beam to form a first parallel light;

[0011] The beam shaping element is disposed between the light source and the collimation system, and is used to shape the beam emitted by the light source and output the shaped beam to the collimation system so that the first parallel light is emitted as the second parallel light after being expanded by the reflection grating.

[0012] And / or, the beam shaping element is disposed between the collimation system and the reflection grating, for shaping the first parallel light emitted after passing through the collimation system, so as to output the shaped beam to the reflection grating; after pupil dilation by the reflection grating, it is emitted as the second parallel light;

[0013] And / or, the beam shaping element is disposed on the light output channel of the reflective grating, for shaping the second parallel light obtained after pupil expansion by the reflective grating, and outputting the shaped beam.

[0014] For example, the beam shaping element is a cylindrical lens;

[0015] The cylindrical lens is a convex cylindrical lens and / or a concave cylindrical lens;

[0016] And / or, the cylindrical lens is a cylindrical lens or a semi-cylindrical lens.

[0017] For example, the beam shaping element includes a first lens, which is disposed on the output channel of the first parallel light or the second parallel light and shapes it;

[0018] Alternatively, it may include a first lens and a second lens, which are arranged sequentially along the optical path. The first lens is placed on the output channel of the first parallel light or the second parallel light and shapes it. The second lens collimates the beam emitted from the first lens and then outputs it.

[0019] For example, the angle at which the light beam is incident on the reflective grating is less than or equal to 45°.

[0020] For example, the incident angle when the light beam is obliquely incident on the reflective grating The following condition must be met: the incident angle The tangent value is the ratio of the aperture of the beam emitted from the reflective grating to the aperture of the beam incident on the reflective grating, which is a preset value.

[0021] For example, the reflective grating is a one-dimensional reflective grating, and / or the grating constant of the reflective grating is matched with the wavelength of the light source;

[0022] And / or may also include an adjustment mechanism; the adjustment mechanism is in contact with the reflective grating and is used to change the placement angle of the reflective grating.

[0023] For example, the light source includes a first light source and a second light source, and the pupil dilation system further includes a light combining element;

[0024] The light combining element is located on the optical path between the light source and the reflective grating; wherein the first light source and the second light source are light sources of the same type or different types.

[0025] For example, it also includes a hologram; the hologram is located on the light-emitting side of the reflective grating; and / or the hologram is attached to the reflective grating by means of imprinting, etching, masking or exposure and development.

[0026] To solve the above-mentioned technical problems, this utility model also provides a pupil expansion system, including: a light source, a collimation system and a reflective grating;

[0027] The light source is used to emit a light beam;

[0028] The collimation system and the reflective grating are located sequentially in the transmission direction of the light beam emitted by the light source;

[0029] The collimation system is used to collimate the light beam emitted by the light source to form a first parallel light. The first parallel light is incident on the reflective grating and exits as a second parallel light after being dilated by the reflective grating. The reflective grating is placed at an angle relative to the first parallel light.

[0030] For example, the tilt angle of the reflective grating relative to the first parallel light is less than or equal to 45°;

[0031] And / or, the angle of incidence when the first parallel light is incident on the reflective grating The following condition must be met: the incident angle The tangent value is the pre-set ratio of the beam aperture of the second parallel light to the beam aperture of the first parallel light; the angle between the first parallel light and the reflecting grating is...

[0032] And / or, the reflective grating is a one-dimensional reflective grating;

[0033] And / or, the grating constant of the reflective grating is matched with the wavelength of the light source.

[0034] For example, the light source includes a first light source and a second light source, and the pupil dilation system further includes a light combining element;

[0035] The light combining element is located in the optical path between the light source and the collimation system;

[0036] The first light source and the second light source are either of the same type or different types.

[0037] For example, it also includes holograms;

[0038] The hologram is located on the light-emitting side of the reflective grating;

[0039] And / or, also includes adjusting mechanisms;

[0040] The adjustment mechanism contacts the reflective grating and is used to change the placement angle of the reflective grating;

[0041] And / or, also includes an electro-optic modulator;

[0042] The electro-optic modulator is located between the light source and the collimation system and is used to adjust the phase distribution or amplitude of the light beam.

[0043] For example, the collimation system is a single lens, a combination of lenses, or a curved mirror.

[0044] To solve the above-mentioned technical problems, this utility model also provides a display device, including the above-mentioned pupil expansion system.

[0045] The present invention provides a pupil expansion system comprising a light source, a reflective grating, and a beam shaping element. First, the pupil expansion of the beam is achieved using a reflective grating, allowing users to observe image information over a wider range. Compared to achieving pupil expansion through optical waveguides, this invention uses a reflective grating, eliminating the coupling-in and coupling-out process, reducing energy loss, improving energy utilization, and enhancing the user experience when using devices with pupil expansion systems. Furthermore, the reflective grating is tilted relative to the first parallel light beam, ensuring that the beam passing through it can enter the human eye. Second, beam shaping elements are located on the incident and / or exit light paths of the reflective grating for beam shaping. Since the beam may become elliptical after passing through the reflective grating, this pupil expansion system can pre-shape the beam using beam shaping elements on the incident light path of the reflective grating. Then, the shaped beam is shaped again after passing through the reflective grating, and / or the deformed beam is shaped again using beam shaping elements on the exit light path of the reflective grating, resulting in a circular beam. Compared to the human eye's reception of an elliptical beam of light, the pupil-expanding system provided by this invention can output a circular beam of light, meaning the human eye can receive a circular beam. Because the circular beam has uniform energy distribution in all directions, it ensures that the user can obtain a consistent and clear viewing experience from any angle.

[0046] The pupil-expanding system provided by this invention includes a collimation system and a reflective grating, which are sequentially placed along the transmission direction of the light beam emitted from the light source. The light beam emitted from the light source is collimated into parallel light by the collimation system, then incident on the reflective grating, and exits as parallel light after passing through the reflective grating. This pupil-expanding system utilizes the reflective grating to achieve pupil expansion, allowing users to observe image information over a wider range. Compared to achieving pupil expansion through optical waveguides, this invention uses a reflective grating, eliminating the coupling in and out processes, reducing energy loss, improving energy utilization, and enhancing the user experience when using a device containing a pupil-expanding system. Furthermore, the reflective grating is placed at an angle relative to the first parallel light beam, ensuring that the light beam passing through the reflective grating can enter the human eye.

[0047] In addition, this utility model also provides a display device, including the above-mentioned pupil expansion system, which has the same beneficial effects as the pupil expansion system mentioned above. Attached Figure Description

[0048] To more clearly illustrate the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0049] Figure 1 is a schematic diagram of a pupil dilation system provided in the first embodiment of this utility model;

[0050] Figure 2 is a schematic diagram of a pupil dilation system provided in the second embodiment of this utility model;

[0051] Figure 3 is a schematic diagram of a reflection grating diffraction provided in an embodiment of the present invention;

[0052] Figure 4 is a schematic diagram of another reflection grating diffraction provided in an embodiment of the present invention;

[0053] Figure 5 is a schematic diagram of a pupil dilation system provided in the third embodiment of this utility model;

[0054] Figure 6 is a schematic diagram of a pupil expansion system with beam shaping function provided in an embodiment of the present invention;

[0055] Figure 7 is a schematic diagram of the installation direction of a beam shaping element provided in an embodiment of the present invention.

[0056] The attached figures are labeled as follows:

[0057] 1-Light source; 2-Collimation system; 3-Reflection grating; 4-Human eye; 5-Holographic sheet; Curved mirror-21; 6-Beam shaping element; 6.1-First lens; 6.2-Second lens. Detailed Implementation

[0058] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0059] The core of this utility model is to provide a pupil expansion system and a display device to solve the technical problem of low energy utilization in pupil expansion systems, which affects the user experience.

[0060] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Figure 1 is a schematic diagram of a pupil expansion system provided in the first embodiment of the present invention. As shown in Figure 1, it includes: a light source 1, a collimation system 2, and a reflective grating 3;

[0061] Light source 1 is used to emit a beam of light;

[0062] The collimation system 2 and the reflection grating 3 are located sequentially in the transmission direction of the light beam emitted by the light source 1;

[0063] The collimation system 2 is used to collimate the light beam emitted by the light source 1 to form a first parallel light. The first parallel light is incident on the reflection grating 3, and after the pupil is dilated by the reflection grating 3, it exits as a second parallel light and enters the human eye 4.

[0064] There are no limitations on light source 1; it can be a single light source or multiple light sources. Specifically, light source 1 can be a laser light source, but is not limited to a laser light source. It 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 light source 1 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, light source 1 includes a first light source and a second light source. In this case, the pupil expansion system also includes a light combining element; the light combining element is located in the optical path between light source 1 and collimation system 2. The first light source and the second light source 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 can be a semi-transparent mirror.

[0065] The collimation system 2 used is not limited, as long as it can convert the light beam emitted by the light source 1 into parallel light. For example, the collimation system 2 can be a single lens, a combination of lenses, or a curved reflector 21. Figure 2 is a schematic diagram of a pupil dilation system provided in the second embodiment of this utility model. As shown in Figure 2, the pupil dilation system includes a light source 1, a curved reflector 21, and a reflective grating 3. The light source 1 emits the image light information to be displayed. After the light beam is emitted, it is collimated into parallel light by the curved reflector 21 and incident (it is worth noting that the incident angle here is an acute angle) onto the reflective grating 3. After passing through the reflective grating 3, it is incident as parallel light into the human eye 4. The reflective grating 3 can achieve the enlargement of the exit pupil diameter. After the parallel light exits, it enters the human eye 4, and the human eye 4 obtains the image information. In this embodiment, a curved reflector 21 is used instead of a lens collimation system 2. The characteristics of the reflective grating 3 are used to make the incident light exit in the form of parallel light, which further reduces the size of the system and simplifies the optical path of the system. In addition, the curved reflector 21 not only collimates the light but also corrects spherical aberration.

[0066] To achieve optimal diffraction efficiency or a specific diffraction effect, in practice, the grating constant of the reflection grating 3 is matched with the wavelength of the light source 1. That is, the reflection grating 3 satisfies the corresponding grating equation to achieve the expected diffraction effect. According to the multi-slit diffraction theory, when the light wave is incident perpendicularly on the grating, the position of the bright line in the diffraction pattern is determined by formula (1): d sinθ=mλ; (1)

[0067] When light waves are obliquely incident on a grating, the general expression for the grating equation is:

[0068] Where m is an integer, and d is the grating constant, which is the distance between two adjacent grating lines. Let θ be the incident angle, θ be the diffraction angle, and λ be the wavelength of the light source.

[0069] To ensure that the light beam passing through the reflective grating 3 can enter the human eye, in practice, the reflective grating 3 is placed at an angle relative to the first parallel light, as shown in Figure 1. Specifically, the tilt angle of the reflective grating 3 relative to the first parallel light (angle a in Figure 1) is less than or equal to 45°. Because the tilt angle of the reflective grating 3 is small, the volume occupied by the reflective grating 3 in the entire pupil dilation system is also correspondingly small, allowing it to be made exquisite and compact, thus giving the pupil dilation system a small size.

[0070] Figure 3 is a schematic diagram of a reflection grating diffraction provided in an embodiment of this utility model. The grating equation in Figure 3 is: Figure 4 is a schematic diagram of another reflection grating diffraction provided in an embodiment of this utility model. The grating equation in Figure 4 is:

[0071] The incident angle of the first parallel light, after being collimated by collimation system 2, when it strikes the reflection grating 3 is not limited, but determined according to the actual situation. The following conditions must be met: angle of incidence The tangent value is the pre-set ratio of the beam aperture of the second parallel light to the beam aperture of the first parallel light; the angle between the first parallel light and the reflection grating 3 is... Specifically, the beam aperture can be obtained from the exit pupil diameter of the beam emitted from light source 1 after passing through collimation system 2. As shown in Figure 1, the angle between the incident ray reaching the reflecting grating 3 and the ray exiting from the reflecting grating 3 is 90°. The angle between the incident light and the reflecting grating 3 can be calculated based on the required pupil enlargement. The beam diameter is designed based on the specific collimation system 2, and is assumed to be 'a'; the required beam diameter after enlargement is 'b', then b / a is the tangent of the incident angle; the incident angle can be calculated from the arctangent. The angle between the incident light and the reflecting grating 3 is

[0072] After determining the angles of the incident and outgoing rays, a reflective grating 3 can be designed so that the rays incident at the required incident angle pass through the reflective grating 3 and exit at the required outgoing angle with maximum light intensity, thereby achieving the purpose of pupil dilation.

[0073] After passing through the reflective grating 3, the image light information to be displayed emitted by the light source 1 enters the human eye 4. In order to enable the human eye 4 to obtain an accurate image, in this implementation, the reflective grating 3 is selected as a one-dimensional reflective grating, which avoids changes in the image shape and improves the user's experience when using the pupil dilation system.

[0074] When using this pupil dilation system, the information observed by the human eye 4 will differ depending on the light source 1 used.

[0075] When the light source 1 is a single light source, this pupil-expanding system is also called a single-light-source pupil-expanding system. Taking light source 1 as the image source as an example, light source 1 emits the image light information required by the user; collimation system 2 is used to collimate the image light information emitted by light source 1 into parallel light incident on reflective grating 3; reflective grating 3 is used to receive the incident image light information and emit the image light information in the form of parallel light, while also realizing the pupil-expanding function; the human eye 4 receives the image light information after pupil expansion through reflective grating 3. In order to enable the user to see more information through the pupil-expanding system, in addition to using light source 1 as a single light source, reflective grating 3 is also placed in the white light path. That is, this pupil-expanding system is a dual-light pupil-expanding system composed of white light + single light source. When the single light source is used as the image source, the human eye 4 can see the real scene in the white light direct channel at the same time as viewing the image light information.

[0076] When multiple light sources are used (1), the pupil-expanding system is also called a multi-light source pupil-expanding system. For example, using a first light source and a second light source forms a dual-light system consisting of the first light source and the second light source. Furthermore, if a reflective grating 3 is placed in the white light path in addition to using multiple light sources (1), a multi-light pupil-expanding system consisting of white light and multiple light sources will be formed. This can also result in a three-light fusion pupil-expanding system consisting of white light, the first light source, and the second light source.

[0077] In practice, to improve the aiming accuracy of the pupil expansion system, a hologram 5 is also included in the system; the hologram 5 is located on the light-emitting side of the reflective grating 3. The hologram 5 can be placed at a distance from the reflective grating 3 (as shown in Figure 5), or it can be attached to the reflective grating 3 by imprinting, etching, masking, or exposure and development. To reduce the system size, it can be attached to the reflective grating 3 by imprinting, etching, masking, or exposure and development.

[0078] Figure 5 is a schematic diagram of a pupil expansion system provided in the third embodiment of the present invention. As shown in Figure 5, the pupil expansion system includes a light source 1, a collimation system 2, a reflective grating 3, and a hologram 5. The light beam emitted by the light source 1 is collimated into parallel light by the collimation system 2 and incident on the reflective grating 3. After passing through the reflective grating 3, the light beam is incident on the hologram 5 as parallel light, and the human eye 4 obtains the division information recorded on the hologram 5.

[0079] Specifically, when the light source 1 is a single light source, this pupil-expanding system is also called a single-source pupil-expanding system. Taking a laser light source as an example, after the laser light source emits a beam, the collimation system 2 collimates the beam into parallel light that is incident on the reflective grating 3. The reflective grating 3 receives the incident beam, and after passing through the reflective grating 3, the beam is incident on the hologram 5 as parallel light. The human eye 4 obtains the division information recorded on the hologram 5. In order to enable the user to see more information through the pupil-expanding system, in addition to using a single light source 1, the reflective grating 3 is also placed in the white light path. That is, this pupil-expanding system is a dual-light pupil-expanding system composed of white light + a single light source. When the single light source used is a laser light source, the human eye 4 can see the real scene in the white light direct passage while viewing the division information recorded on the hologram 5.

[0080] When multiple light sources are used (1), the pupil-expanding system is also called a multi-source pupil-expanding system. For example, using a first light source and a second light source creates a dual-light system consisting of the first and second light sources. Furthermore, if a reflective grating 3 is placed in the white light path in addition to using multiple light sources (1), a multi-light pupil-expanding system consisting of white light and multiple light sources will be formed. This can also create a three-light fusion pupil-expanding system consisting of white light, the first light source, and the second light source. When the first light source is a laser source and the second light source is an image source, this system allows the viewer to see holographic reticulation information and image source information without obstructing the white light direct path, allowing the viewer to see the actual scene within the white light direct path.

[0081] To improve image quality, the pupil dilation system also includes an adjustment mechanism during implementation;

[0082] The adjustment mechanism contacts the reflective grating 3 to change the placement angle of the reflective grating 3.

[0083] The adjustment mechanism is not limited, as long as it allows for adjustment of the placement angle of the reflective grating 3. By rotating or tilting the adjustment mechanism, the angle of the reflective grating 3 relative to the incident beam can be changed, thereby adjusting the direction of the diffracted light. Furthermore, once the reflective grating 3 is adjusted to the appropriate position using the adjustment mechanism, the mechanism typically has a locking mechanism to maintain the grating's fixed position and prevent displacement due to vibration or other external factors.

[0084] Furthermore, to improve image quality, the pupil dilation system also includes an electro-optic modulator in its implementation;

[0085] An electro-optic modulator is located between the light source 1 and the collimation system 2, and is used to adjust the phase distribution or amplitude of the beam.

[0086] There are no restrictions on the type of electro-optic modulator used, such as a phase modulator or an amplitude modulator. The electro-optic modulator can change the diffraction efficiency and diffraction angle of the grating by dynamically adjusting the phase distribution of the beam, or by changing the voltage applied to the electro-optic modulator to dynamically adjust the phase or amplitude of the beam, thereby changing the diffraction characteristics of the grating.

[0087] The pupil-expanding system provided in this embodiment includes a collimation system 2 and a reflective grating 3, which are sequentially placed along the transmission direction of the light beam emitted from the light source 1. The light beam emitted from the light source 1 is collimated into parallel light by the collimation system 2, incident on the reflective grating 3, and then exits as parallel light after passing through the reflective grating 3. This pupil-expanding system utilizes a reflective grating 3 to expand the pupil of the light beam, allowing users to observe image information over a wider range. Compared to achieving pupil expansion through optical waveguides, the reflective grating 3 eliminates the coupling-in and coupling-out process, reducing energy loss, improving energy utilization, and enhancing the user experience when using devices incorporating pupil-expanding systems. A curved reflector serves as the collimation system 2, and the characteristics of the reflective grating 3 ensure that the incident light exits as parallel light, further reducing the system's size and simplifying the optical path. A hologram 5 is placed between the reflective grating 3 and the user's eye 4. After passing through the reflective grating 3 and the hologram 5, the light beam expands, allowing the user to see the reticle information on the hologram 5, further improving the user experience when using the pupil-expanding system.

[0088] In addition to the pupil-expanding system provided above, considering that when the angle between the reflective grating 3 and the incident light is 45°, the emitted beam is parallel light and the light spot shape remains circular; however, when the angle between the reflective grating 3 and the incident light is not 45°, the emitted beam is parallel light, but the light spot shape becomes elliptical, affecting the user's observation. Therefore, this utility model embodiment also provides a pupil-expanding system with beam shaping function. Figure 6 is a schematic diagram of a pupil-expanding system with beam shaping function provided by this utility model embodiment. As shown in Figure 6, it includes: a light source 1, a reflective grating 3, and a beam shaping element 6; the light source 1 is used to emit a light beam;

[0089] The light beam emitted by the light source 1 is obliquely incident on the reflective grating 3, and exits after being dilated by the reflective grating 3;

[0090] The beam shaping element 6 is located on the incident light path and / or the outgoing light path of the reflective grating 3, and is used to perform beam shaping.

[0091] In some possible implementations, the pupil dilation system further includes a collimation system 2. The collimation system 2 is located between the light source 1 and the reflective grating 3, and is used to collimate the light beam to form a first parallel beam. The collimation system 2 is a single lens, a combination of lenses, or a curved mirror 21.

[0092] In some possible implementations, the tilt angle of the beam incident on the reflective grating 3 is less than or equal to 45°. When a collimation system 2 is provided between the light source 1 and the reflective grating 3, the tilt angle of the reflective grating 3 relative to the first parallel light is less than or equal to 45°.

[0093] Angle of incidence when the light beam is obliquely incident on the reflection grating 3 The following conditions must be met: angle of incidence The tangent value is the ratio of the aperture of the beam emitted from the reflection grating 3 to the aperture of the beam incident on the reflection grating 3, as preset. Taking the aforementioned pupil expansion system including the collimation system 2 as an example, it represents the incident angle when the first parallel light is incident on the reflection grating 3. The following conditions must be met: angle of incidence The tangent value is the pre-set ratio of the beam aperture of the second parallel light to the beam aperture of the first parallel light; the angle between the first parallel light and the reflection grating 3 is...

[0094] In some possible implementations, the reflective grating 3 is a one-dimensional reflective grating, and / or the grating constant of the reflective grating 3 is matched with the wavelength of the light source 1. The pupil dilation system also includes an adjustment mechanism; the adjustment mechanism contacts the reflective grating 3 and is used to change the placement angle of the reflective grating 3.

[0095] In some possible implementations, light source 1 includes a first light source and a second light source, and the pupil dilation system also includes a light combining element;

[0096] The light combining element is located in the optical path between the light source 1 and the reflective grating 3. Specifically, the light combining element can be located in the optical path between the light source 1 and the collimation system 2.

[0097] The first light source and the second light source are of the same type or different types; among them, the light source type includes at least point light source type and image source type.

[0098] The pupil expansion system also includes a hologram 5; the hologram 5 is located on the light-emitting side of the reflective grating 3; and / or the hologram 5 is attached to the reflective grating 3 by means of imprinting, etching, masking or exposure and development.

[0099] The pupil expansion system with beam shaping function provided in this embodiment has the same technical features as the pupil expansion system described above. Please refer to the description above for details, which will not be repeated here. Only the relevant content for realizing beam shaping will be explained here.

[0100] When the angle between the reflective grating 3 and the incident light is not 45°, or when there are other situations that cause the light beam to deform, the light beam may be deformed after passing through the reflective grating 3, and the shape of the light spot becomes elliptical. Therefore, in the pupil expansion system provided by this utility model, the beam shaping element 6 is set in the incident light path and / or the outgoing light path of the reflective grating 3 for beam shaping.

[0101] The collimation system 2 and the reflection grating 3 are sequentially located in the transmission direction of the light beam emitted by the light source 1. The collimation system 2 is used to collimate the light beam to form the first parallel light. Specifically, the beam shaping element 6 can be located between the light source 1 and the collimation system 2. In this case, the beam shaping element 6 is used to shape the light beam emitted by the light source 1 and output the shaped light beam to the collimation system 2 so that the first parallel light is reflected by the reflection grating 3 and emitted as the second parallel light.

[0102] And / or, the beam shaping element 6 may be located between the collimation system 2 and the reflection grating 3, for shaping the first parallel light obtained after the beam emitted from the light source 1 passes through the collimation system 2, so as to output the shaped beam to the reflection grating 3; after being reflected by the reflection grating 3, it is emitted as the second parallel light. Specifically, in this process, the beam shaping element 6 transforms the circular first parallel light into an elliptical beam, outputs it to the reflection grating 3, and after being dilated by the reflection grating 3, it becomes a circular beam, and finally exits as a circular second parallel light.

[0103] And / or, the beam shaping element 6 may be located in the outgoing light path of the reflective grating 3, for shaping the second parallel light obtained after reflection by the reflective grating 3, and then outgoing the shaped beam. Specifically, in this process, the beam shaping element 6 shapes the elliptical second parallel light obtained after pupil dilation by the reflective grating 3 into a circular beam, and then outgoing it.

[0104] In implementation, the beam shaping element 6 is a cylindrical lens. And / or, the cylindrical lens is a circular cylindrical lens or a semi-cylindrical cylindrical lens. A cylindrical lens is a lens with different radii on the X and Y axes. A cylindrical lens has image magnification only on a single optical axis, which can magnify the short axis of the light spot or reduce the long axis of the light spot. And / or, the cylindrical lens is a convex cylindrical lens and / or a concave cylindrical lens. A convex cylindrical lens can shorten the long side of the light spot; a concave cylindrical lens can lengthen the short side of the light spot. In practice, when the beam shaping element 6 is simultaneously located in multiple positions mentioned above, a convex cylindrical lens and / or a concave cylindrical lens can be selected based on the deformation of the beam by the reflective grating 3, to ensure that the human eye 4 receives a circular light spot as much as possible, thereby improving the user's visual experience. Figure 7 is a schematic diagram of the installation direction of a beam shaping element provided in an embodiment of the present invention. As shown in Figure 7, the beam shaping element 6 includes a first lens 6.1 and a second lens 6.2. In actual use, the first lens 6.1 can be set alone and placed on the output channel of the first parallel light or the second parallel light to shape it; or it can include both the first lens 6.1 and the second lens 6.2. The first lens 6.1 and the second lens 6.2 are arranged sequentially along the optical path. The first lens 6.1 is placed on the output channel of the first parallel light or the second parallel light to shape it, and the second lens 6.2 collimates the beam emitted from the first lens 6.1 before outputting it. The first lens 6.1 with a focal length of f1 shapes the incident beam (the diameter of the input beam spot is h1), and the second lens 6.2 with a focal length of f2 collimates the beam before outputting the beam (the diameter of the output beam spot is h2).

[0105] This invention provides a pupil expansion system comprising a light source 1, a reflective grating 3, and a beam shaping element 6. First, the reflective grating 3 is used to expand the pupil of the beam, allowing users to observe image information over a wider range. Compared to achieving pupil expansion through optical waveguides, the reflective grating 3 eliminates the coupling-in and coupling-out process, reducing energy loss, improving energy utilization, and enhancing the user experience when using devices with pupil expansion systems. Furthermore, the reflective grating 3 is tilted relative to the first parallel light beam, ensuring that the beam passing through it can enter the human eye. Second, the beam shaping element 6 is located on the incident and / or exit optical paths of the reflective grating 3 for beam shaping. Since the beam spot shape becomes elliptical after passing through the reflective grating 3, this pupil expansion system can pre-shape the beam using the beam shaping element 6 on the incident optical path of the reflective grating 3. Then, the shaped beam is shaped again after passing through the reflective grating 3, and / or the beam deformed after passing through the reflective grating 3 is shaped again using the beam shaping element 6 on the exit optical path of the reflective grating 3, resulting in a circular beam. Compared to the human eye receiving an elliptical beam of light, the pupil-expanding system provided by this invention can output a circular beam of light, meaning the human eye can receive a circular beam of light. Because the circular beam has a uniform energy distribution in all directions, it ensures that the user can obtain a consistent and clear viewing experience from any angle.

[0106] The foregoing description describes a pupil-expanding system. This embodiment also provides a display device that includes the aforementioned pupil-expanding system. The display device including the pupil-expanding system can be augmented reality (AR) glasses, a scope, or the like.

[0107] The display device provided in this embodiment includes the pupil expansion system described above. The embodiments of the pupil expansion system have been described in detail above, and the embodiments of the pupil expansion system included in the display device will not be repeated here.

[0108] The display device provided in this embodiment of the present invention includes a pupil expansion system. The pupil expansion system includes a collimation system 2 and a reflective grating 3, which are sequentially placed along the transmission direction of the light beam emitted from the light source 1. The light beam emitted from the light source 1 is collimated into parallel light by the collimation system 2 and incident on the reflective grating 3, then exits as parallel light after passing through the reflective grating 3. This pupil-expanding system utilizes a reflective grating 3 to expand the pupil of the light beam, allowing users to observe image information over a wider range. Compared to achieving pupil expansion through optical waveguides, the reflective grating 3 eliminates the coupling-in and coupling-out process, reducing energy loss, improving energy utilization, and enhancing the user experience when using a device with a pupil-expanding system. A curved reflector serves as the collimation system, and the characteristics of the reflective grating 3 ensure that the incident light exits as parallel light, further reducing the system's size and simplifying the optical path. A hologram 5 is placed between the reflective grating 3 and the user's eye 4. After passing through the reflective grating 3 and the hologram 5, the light beam expands, allowing the user to see the reticle information on the hologram. A display device incorporating this pupil-expanding system effectively increases the range of virtual images visible to the user, making it closer to the natural field of view of the human eye and improving the user experience when using the display device.

[0109] The foregoing has provided a detailed description of the pupil expansion system and display device provided by this utility model. 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 utility model without departing from its principles, and these improvements and modifications also fall within the protection scope of this utility model.

[0110] 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 mydriasis system characterized by, include: A light source (1), a reflective grating (3), and a beam shaping element (6); the light source (1) is used to emit a light beam; The light beam emitted by the light source (1) is obliquely incident on the reflective grating (3), and exits after being dilated by the reflective grating (3); The beam shaping element (6) is located on the incident light path and / or the outgoing light path of the reflective grating (3) and is used for beam shaping.

2. The mydriasis system according to claim 1, characterized by It also includes a collimation system (2); the collimation system (2) is disposed between the light source (1) and the reflective grating (3) and is used to collimate the light beam to form a first parallel light; The beam shaping element (6) is disposed between the light source (1) and the collimation system (2) for shaping the beam emitted by the light source (1) and outputting the shaped beam to the collimation system (2) so that the first parallel light is emitted as the second parallel light after being dilated by the reflection grating (3). And / or, the beam shaping element (6) is disposed between the collimation system (2) and the reflection grating (3) for shaping the first parallel light emitted after passing through the collimation system (2) to output the shaped beam to the reflection grating (3); after pupil dilation by the reflection grating (3), the second parallel light is emitted; And / or, the beam shaping element (6) is disposed on the light output channel of the reflective grating (3) for shaping the second parallel light obtained after pupil expansion by the reflective grating (3) and outputting the shaped beam.

3. The mydriasis system according to claim 2, characterized by The beam shaping element (6) is a cylindrical lens; The cylindrical lens is a convex cylindrical lens and / or a concave cylindrical lens; And / or, the cylindrical lens is a cylindrical lens or a semi-cylindrical lens.

4. The mydriatic system of claim 2, wherein, The beam shaping element (6) includes a first lens (6.1), which is disposed on the output channel of the first parallel light or the second parallel light and shapes it; Alternatively, it may include the first lens (6.1) and the second lens (6.2), which are arranged sequentially along the optical path. The first lens (6.1) is disposed on the output channel of the first parallel light or the second parallel light and shapes it. The second lens (6.2) collimates the beam emitted from the first lens (6.1) and outputs it.

5. The mydriasis system according to claim 1, wherein The tilt angle of the beam incident on the reflective grating (3) is less than or equal to 45°.

6. The mydriasis system according to claim 1, wherein When the light beam is obliquely incident on the reflective grating (3), the incident angle φ satisfies the following condition: the tangent of the incident angle φ is the ratio of the aperture of the light beam emitted from the reflective grating (3) to the aperture of the light beam incident on the reflective grating (3).

7. The mydriatic system according to any one of claims 1 to 6, wherein The reflective grating (3) is a one-dimensional reflective grating, and / or the grating constant of the reflective grating (3) is matched with the wavelength of the light source (1); And / or may also include an adjustment mechanism; the adjustment mechanism contacts the reflective grating (3) and is used to change the placement angle of the reflective grating (3).

8. The mydriasis system according to claim 1, wherein The light source (1) includes a first light source and a second light source, and the pupil dilation system further includes: a light combining element; The light combining element is located in the optical path between the light source (1) and the reflective grating (3); wherein the first light source and the second light source are light sources of the same type or different types.

9. The mydriasis system according to claim 1, wherein It also includes a hologram (5); the hologram (5) is located on the light-emitting side of the reflective grating (3); and / or the hologram (5) is attached to the reflective grating (3) by means of imprinting, etching, masking or exposure and development.

10. A mydriasis system characterized by, include: Light source (1), collimation system (2), and reflection grating (3); The light source (1) is used to emit a light beam; The collimation system (2) and the reflection grating (3) are located sequentially in the transmission direction of the light beam emitted by the light source (1); The collimation system (2) is used to collimate the light beam emitted by the light source (1) to form a first parallel light. The first parallel light is incident on the reflective grating (3) and emitted as a second parallel light after the pupil is expanded by the reflective grating (3). The reflective grating (3) is placed at an angle relative to the first parallel light.

11. The mydriasis system according to claim 10, characterized by The tilt angle of the reflective grating (3) relative to the first parallel light is less than or equal to 45°; And / or, the incident angle φ when the first parallel light is incident on the reflective grating (3) satisfies the following conditions: the tangent of the incident angle φ is the ratio of the pre-set beam aperture of the second parallel light to the beam aperture of the first parallel light; the angle between the first parallel light and the reflective grating (3) is 90°-φ. And / or, the reflective grating (3) is a one-dimensional reflective grating; And / or, the grating constant of the reflective grating (3) is matched with the wavelength of the light source (1).

12. The mydriasis system according to claim 10, wherein The light source (1) includes a first light source and a second light source, and the pupil dilation system further includes: a light combining element; The light combining element is located in the optical path between the light source (1) and the collimation system (2); The first light source and the second light source are either of the same type or different types.

13. The mydriasis system of claim 10, wherein, It also includes holograms (5); The hologram (5) is located on the light-emitting side of the reflective grating (3); And / or, also includes adjusting mechanisms; The adjustment mechanism contacts the reflective grating (3) to change the placement angle of the reflective grating (3); And / or, also includes an electro-optic modulator; The electro-optic modulator is located between the light source (1) and the collimation system (2) and is used to adjust the phase distribution or amplitude of the light beam.

14. The mydriatic system according to any one of claims 10 to 13, wherein, The collimation system (2) is a single lens, a combination of lenses, or a curved mirror (21).

15. A display device, characterized by Includes the pupil dilation system according to any one of claims 1 to 14.

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