Virtual image imaging device

Abstract

The present application relates to the technical field of virtual reality imaging device, disclose a kind of virtual image imaging device, including image generation unit, microstructure flat component and curved mirror, microstructure flat component includes first microstructure flat and second microstructure flat, the interval of first flat surface of first microstructure flat and the second flat surface of first microstructure flat is d, d>0;Image generation unit to microstructure flat component distance is L1, microstructure flat component to curved mirror distance is L2, the focal length of curved mirror is f, L1+L2<f.Because object distance is within 1 times focal length of curved mirror, so that the virtual image that human eye can see by the virtual image imaging device.By the back-to-back arrangement of second microstructure flat and first microstructure flat, the different optical path difference of light penetration first microstructure flat in different positions is compensated, thereby reducing dispersion, improve the imaging quality of virtual image imaging device.

Description

Technical Field

[0001] This invention relates to the technical field of virtual reality imaging devices, and more specifically, to a virtual image imaging device. Background Technology

[0002] Virtual image imaging technology is an important optical imaging method widely used in virtual reality (VR), augmented reality (AR), 3D displays, and immersive visual systems. Its core principle is to use lenses, curved mirrors, or other optical elements to magnify tiny images on a display device through a specific optical path, forming a clear virtual image in front of the viewer's eyes. This technology can significantly expand the field of view (FOV) of display devices, enhancing visual immersion, while avoiding the weight and space limitations of traditional large-size physical screens.

[0003] Common virtual image imaging devices include VR head-mounted displays (HMDs), which use lens systems or optical reflection systems to magnify and project images from miniature displays (such as OLEDs or LCDs), giving users the visual effect of viewing a large screen. In addition, virtual image imaging technology is also used in automotive head-up displays (HUDs), AR smart glasses, projection systems, and glasses-free 3D devices.

[0004] For example, in the prior art CN209514209U, a microdisplay imaging optical system based on an optical prism is introduced. Its optical prism design includes an incident surface, a total internal reflection surface, and an exit surface. The total internal reflection surface is used to optimize the optical path, allowing light to form a larger virtual image in front of the user. This system is mainly suitable for near-eye display devices (such as VR / AR glasses). However, many people are not comfortable with head-mounted near-eye display devices and are prone to dizziness. If the above near-eye display optical system is applied to a desktop virtual image display device, the required prism size would be very large, leading to increased manufacturing difficulty and cost, and potentially affecting the stability of optical performance. Summary of the Invention

[0005] The purpose of this invention is to provide a virtual image imaging device, which aims to solve the problem in the prior art of lacking a suitable virtual image imaging device for non-near-eye display situations.

[0006] The present invention is implemented as follows: a virtual image imaging device includes an image generation unit, a microstructure plate assembly, and a curved reflector. The microstructure plate assembly includes a first microstructure plate and a second microstructure plate. The first microstructure plate includes a first microstructure surface and a first plate surface opposite to the first microstructure. The second microstructure plate includes a second microstructure surface and a second plate surface opposite to the second microstructure. The first plate surface and the second plate surface are arranged opposite to each other and in parallel. The distance between the first plate surface and the second plate surface is d, where d>0.

[0007] The light emitted by the image generation unit is incident on the first microstructure surface, reflected by the first flat plate surface, and then incident on the curved reflector. The light reflected by the curved reflector is incident on the first microstructure surface again, and then passes through the first microstructure plate and the second microstructure plate in sequence, and exits from the second microstructure surface.

[0008] In the imaging optical path, the distance from the image generation unit to the microstructured flat panel assembly is L1, the distance from the microstructured flat panel assembly to the curved reflector is L2, and the focal length of the curved reflector is f, where L1 + L2 <f。

[0009] Furthermore, the light emitted by the image generation unit undergoes total internal reflection on the first flat surface.

[0010] Furthermore, both the first and second microstructure surfaces are provided with periodic serrated microstructures.

[0011] Furthermore, the first microstructure surface includes a plurality of horizontally arranged first horizontal planes and a plurality of vertically arranged first vertical planes, the first horizontal planes and the first vertical planes being perpendicular to each other, and the plurality of first horizontal planes and the plurality of first vertical planes being arranged alternately to form a periodic sawtooth-shaped microstructure.

[0012] Furthermore, the incident angle of the light emitted by the image generation unit onto the first horizontal plane is θ, where 0 < θ < 45°.

[0013] Furthermore, the curved reflector is a concave mirror, and the reflecting surface of the concave mirror is spherical, aspherical, or freeform.

[0014] Furthermore, the first flat surface is arranged at an angle of 45°.

[0015] Furthermore, the image generation unit is an LCD display or an OLED display.

[0016] Furthermore, the materials of the first microstructure plate and the second microstructure plate are optical glass or plastic.

[0017] Furthermore, the reflective surface of the curved mirror is coated with a metal film layer or a multilayer dielectric film.

[0018] Compared with existing technologies, the virtual image imaging device provided by this invention allows the human eye to see a virtual image because the distance from the image generation unit to the microstructure plate assembly plus the distance from the microstructure plate assembly to the curved mirror is less than one focal length of the curved mirror. Furthermore, by arranging the second microstructure plate back-to-back with the first microstructure plate, the different optical path differences at different positions of the first microstructure plate are compensated for, thereby reducing chromatic aberration and improving the imaging quality of the virtual image imaging device.

[0019] In addition, compared with existing technologies that use optical prisms for virtual image imaging (such as CN209514209U), the microstructure flat panel assembly is relatively small in size and has a higher stability in manufacturing process; due to the use of total internal reflection technology, large-area film application process is avoided, reducing manufacturing costs and technical difficulties.

[0020] Compared to existing virtual image imaging schemes that utilize polarization beam splitting, this method can reduce light loss, improve image clarity, brightness, and contrast, and make the final imaging effect more natural. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the optical path of a virtual image imaging device provided by the present invention;

[0022] Figure 2 This is a schematic diagram of a microstructure flat panel assembly of a virtual image imaging device provided by the present invention.

[0023] Explanation of reference numerals in the attached figures:

[0024] 100 - Image generation unit, 200 - Microstructure plate assembly, 210 - First microstructure plate, 211 - First plate surface, 212 - First horizontal plane, 213 - First vertical plane, 220 - Second microstructure plate, 221 - Second plate surface, 300 - Curved reflector, 400 - Human eye. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0026] The implementation of the present invention will be described in detail below with reference to specific embodiments.

[0027] In the accompanying drawings of this embodiment, the same or similar reference numerals correspond to the same or similar components. In the description of this invention, it should be understood that if terms such as "upper," "lower," "left," and "right" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this invention. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0028] Reference Figure 1-2 The image shown is a preferred embodiment of the present invention.

[0029] A virtual image imaging device includes an image generation unit 100, a microstructure plate assembly 200, and a curved reflector 300. The microstructure plate assembly 200 includes a first microstructure plate 210 and a second microstructure plate 220. The first microstructure plate 210 includes a first microstructure surface and a first plate surface 211 opposite to the first microstructure. The second microstructure plate 220 includes a second microstructure surface and a second plate surface 221 opposite to the second microstructure. The first plate surface 211 and the second plate surface 221 are arranged opposite to each other and in parallel. The distance between the first plate surface 211 and the second plate surface 221 is d, where d>0.

[0030] The light emitted by the image generation unit 100 is incident on the first microstructure surface, reflected by the first flat plate surface 211, and then incident on the curved reflector 300. The light reflected by the curved reflector 300 is incident on the first microstructure surface again, and then passes through the first microstructure plate 210 and the second microstructure plate 220 in sequence before exiting from the second microstructure surface.

[0031] In the imaging optical path, the distance from the image generation unit 100 to the microstructure plate assembly 200 is L1, the distance from the microstructure plate assembly 200 to the curved mirror 300 is L2, and the focal length of the curved mirror 300 is f, where L1 + L2 <f。

[0032] This embodiment provides a virtual image imaging device where the distance from the image generation unit 100 to the microstructure plate assembly 200 plus the distance from the microstructure plate assembly 200 to the curved reflector 300 is less than one focal length of the curved reflector 300. This allows the human eye 400 to see a virtual image through the virtual image imaging device. By arranging the second microstructure plate 220 back-to-back with the first microstructure plate 210, the different optical path differences at different positions of the first microstructure plate 210 are compensated for, thereby reducing chromatic aberration and improving the imaging quality of the virtual image imaging device.

[0033] In addition, compared with the virtual image imaging scheme using optical prisms in the prior art, the microstructure flat panel component 200 is relatively small in size and has higher stability in manufacturing process; since total internal reflection technology is used in this embodiment, large-area film application process is avoided, reducing manufacturing cost and technical difficulty.

[0034] Virtual image imaging schemes using optical prisms may lead to unstable image quality due to coating inconsistencies on the optical surface. However, this embodiment employs a total internal reflection technique, which eliminates the need for coating the total internal reflection surface, reducing coating inconsistency issues and providing a more stable optical path, thereby improving image quality.

[0035] Compared to existing virtual image imaging schemes that utilize polarization beam splitting, this method can reduce light loss, improve image clarity, brightness, and contrast, and make the final imaging effect more natural.

[0036] Specifically, the light emitted by the image generation unit 100 undergoes total internal reflection on the first plate surface 211, so that when the light emitted by the image generation unit 100 is first incident on the first plate surface 211, it will not be transmitted from the first plate surface 211, thereby reducing energy loss and stray light noise, and ensuring the brightness and clarity of the image.

[0037] Specifically, both the first and second microstructure surfaces are provided with periodic sawtooth-shaped microstructures to modulate the light passing through the first and second microstructure surfaces respectively.

[0038] The first microstructure surface includes multiple horizontally arranged first horizontal surfaces 212 and multiple vertically arranged first vertical surfaces 213. The first horizontal surfaces 212 and the first vertical surfaces 213 are perpendicular to each other, and the multiple first horizontal surfaces 212 and the multiple first vertical surfaces 213 are arranged alternately to form a periodic sawtooth-shaped microstructure. The incident angle of the light emitted by the image generation unit 100 onto the first horizontal surface 212 is θ, where 0 < θ < 45°. The first flat plate surface 211 is inclined at an angle of 45°. The light emitted by the image generation unit 100 with a small angle of inclination is incident on the microstructure flat plate assembly 200, that is, on the first horizontal surface 212 at a small angle. Due to the small incident angle, most of the light will be transmitted into the first microstructure flat plate 210 and undergo total internal reflection at the first flat plate surface 211. The light after total internal reflection is basically perpendicular to the first vertical surface 213, and transmission is the main process. The light transmitted from the first vertical surface 213 is incident on the curved reflector 300. After being changed in direction by the curved reflector 300, it is incident on the first microstructure plate 210 again. Because the angle of the light has changed, total internal reflection will not occur at the first plate surface 211. Instead, it will be transmitted out of the first plate surface 211, pass through the second microstructure plate 220, and enter the human eye 400.

[0039] Specifically, when the light reflected by the curved reflector 300 is incident on the first flat plate surface 211, the incident angle is smaller than the total reflection angle, so that the light reflected by the curved reflector 300 transmits through the first flat plate surface 211 without total reflection, which is beneficial to the formation of a virtual image and the improvement of imaging quality.

[0040] The curved reflector 300 is a concave mirror. When L1+L2 < f, that is, when the object distance is within one focal length of the concave mirror, an upright and magnified virtual image is formed. The reflecting surface profile of the concave mirror is spherical, aspheric or free-form. Spherical mirrors are the easiest to process and have low cost. Aspheric concave mirrors minimize the edge aberration and provide a wider field of view. A free-form concave mirror can minimize its aberration and improve imaging quality.

[0041] In one embodiment, an adjustment device is further included for adjusting the distance between the microstructured flat plate assembly 200 and the curved reflector 300. A guide rod translation structure can be adopted. The guide rod translation structure comprises a fixed seat, guide rods arranged in parallel and a screw rod. The guide rods are penetrated on the fixed seat, the screw rod is in threaded connection with the fixed seat, the microstructured flat plate assembly 200 is arranged on the fixed seat, and the screw rod can be driven to rotate manually or by a motor. When the screw rod rotates, it drives the fixed seat to translate on the guide rods, thereby translating the microstructured flat plate assembly 200, adjusting the distance between the microstructured flat plate assembly 200 and the curved reflector 300, and adjusting the size, definition and the like of the virtual image.

[0042] The image generating unit 100 can be an LCD display, an OLED display, a projection device, etc. The light emitted by the image generating unit 100 carries image information.

[0043] The materials of the first microstructured flat plate 210 and the second microstructured flat plate 220 are optical glass or plastic. Optical glass can generally provide better clarity and reduce the loss of light energy during transmission. Plastic is not easy to damage and is impact-resistant. Optical resin materials are generally used, which are suitable for light transmission. Optical resin material is a transparent material made of high-molecular organic compounds by molding, casting or injection molding, and is mainly used for manufacturing optical elements such as spectacle lenses and optical lenses.

[0044] A metal film layer or a multi-layer dielectric film is plated on the reflecting surface of the curved reflector 300 to improve the reflectivity of the curved reflector. The metal film layer is usually processed by silver plating, and the multi-layer dielectric film is usually a high-reflection film layer.

[0045] In one embodiment, the light emitted by the image generating unit 100 can be incident on the collimating lens group first, and then incident on the microstructured flat plate assembly 200. This enables the light carrying image information to be modulated by the microstructured flat plate assembly 200 as much as possible, and then form a clear virtual image through the curved reflector 300; reducing the influence of multi-angle stray light on imaging quality.

[0046] The collimating lens group may include a first collimating lens and a second collimating lens arranged confocally, that is, the back focal point of the first collimating lens coincides with the front focal point of the second collimating lens, and the optical axes of the first collimating lens and the second collimating lens coincide.

[0047] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A virtual image imaging device, characterized in that, The system includes an image generation unit, a microstructure plate assembly, and a curved reflector. The microstructure plate assembly includes a first microstructure plate and a second microstructure plate. The first microstructure plate includes a first microstructure surface and a first plate surface opposite to the first microstructure. The second microstructure plate includes a second microstructure surface and a second plate surface opposite to the second microstructure. The first plate surface and the second plate surface are arranged opposite to each other and in parallel. The distance between the first plate surface and the second plate surface is d, where d>0. The light emitted by the image generation unit is incident on the first microstructure surface, reflected by the first flat plate surface, and then incident on the curved reflector. The light reflected by the curved reflector is incident on the first microstructure surface again, and then passes through the first microstructure plate and the second microstructure plate in sequence, and exits from the second microstructure surface. In the imaging optical path, the distance from the image generation unit to the microstructured flat panel assembly is L1, the distance from the microstructured flat panel assembly to the curved reflector is L2, and the focal length of the curved reflector is f, where L1 + L2 <f。 2. The virtual image imaging device as described in claim 1, characterized in that, The light emitted by the image generation unit undergoes total internal reflection on the first flat surface.

3. The virtual image imaging device as described in claim 2, characterized in that, Both the first and second microstructure surfaces are provided with periodic sawtooth-shaped microstructures.

4. The virtual image imaging device as described in claim 3, characterized in that, The first microstructure surface includes multiple horizontally arranged first horizontal planes and multiple vertically arranged first vertical planes. The first horizontal planes and the first vertical planes are perpendicular to each other, and the multiple first horizontal planes and the multiple first vertical planes are arranged alternately to form a periodic sawtooth-shaped microstructure.

5. The virtual image imaging device as described in claim 4, characterized in that, The incident angle of the light emitted by the image generation unit onto the first horizontal plane is θ, where 0 < θ < 45°.

6. A virtual image imaging device as described in any one of claims 1-5, characterized in that, The curved reflector is a concave mirror, and the reflecting surface of the concave mirror is spherical or aspherical.

7. A virtual image imaging device as described in any one of claims 1-5, characterized in that, The first flat plate is arranged at an angle of 45°.

8. A virtual image imaging device as described in any one of claims 1-5, characterized in that, The image generation unit is an LCD display or an OLED display.

9. A virtual image imaging device as described in any one of claims 1-5, characterized in that, The first microstructure plate and the second microstructure plate are made of optical glass or plastic.

10. A virtual image imaging device according to any one of claims 1-5, characterized in that, The reflective surface of the curved mirror is coated with a metal film or a multilayer dielectric film.

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