Dual screen optical device

Abstract

The present application relates to the technical field of optical equipment, and provides a double-screen optical device, which comprises a first image source, a second image source, a first light guide component, a second light guide component, a reflection imaging unit and an observation area for receiving image light by an observer's eye; the first image light is sequentially guided by the first light guide component, is incident to a first reflection imaging area of the reflection imaging unit, is reflected by the first reflection imaging area, enters the observation area to form a first field of view image; the second image light is sequentially guided by the second light guide component, is incident to a second reflection imaging area of the reflection imaging unit, is reflected by the second reflection imaging area, enters the observation area to form a second field of view image; and the first field of view image and the second field of view image have at least partially different field of view coverage ranges in the observer's field of view.

Description

Technical Field

[0001] This invention belongs to the technical field of optical devices, and more specifically, relates to a dual-screen optical device. Background Technology

[0002] Augmented Reality (AR) near-eye display devices typically need to provide virtual images to the human eye within a small volume while simultaneously allowing ambient light to enter, achieving a seamless blend of virtual and real worlds. BirdBath-type optical modules are widely used in consumer AR devices due to their relatively compact structure, good image quality, and mature manufacturing process. However, traditional BirdBath modules usually use a single microdisplay as the image source, and their field of view is mainly limited by the size of the microdisplay, the optical magnification, and the module's focal length. Refer to Chinese patent application CN106708264A, "Display Device and Wearable Electronic Device," which uses a single display as the image source, transmitting the image displayed on that display to the human eye through one or two lenses. Due to the limited display size, to obtain a larger field of view, it is necessary to shorten the focal length of the optical system or increase the magnification, but this can easily lead to increased aberrations, especially in the image edge areas where blurring, distortion, or image quality degradation are more likely to occur.

[0003] If the field of view is expanded by increasing the size of a single display screen, larger lenses, prisms, or semi-transparent / semi-reflective elements are required, leading to increased module size, weight, power consumption, and heat dissipation pressure. Conversely, if the field of view is increased by shortening the focal length, limitations arise due to optical path folding space, eye distance, eye box size, and manufacturing / assembly tolerances. Therefore, existing single-screen AR optical modules struggle to expand the field of view while maintaining a slim profile, low power consumption, and mass production feasibility. Summary of the Invention

[0004] The purpose of this invention is to provide a dual-screen optical device to solve the technical problem in the prior art that it is difficult to expand the display field of view or field of view angle of near-eye display devices.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is: to provide a dual-screen optical device, comprising: a first image source, a second image source, a first light guide component, a second light guide component, a reflective imaging unit, and an observation area for an observer's eye to receive image light; The first image source is used to emit first image light. The first image light is guided by the first light guide component and then incident on the first reflection imaging area of ​​the reflection imaging unit. After being reflected by the first reflection imaging area, it enters the observation area to form a first field of view image. The second image source is used to emit a second image light, which is guided by the second light guide component and then incident on the second reflection imaging area of ​​the reflection imaging unit. After being reflected by the second reflection imaging area, it enters the observation area to form a second field of view image. Both the first field-of-view image and the second field-of-view image can be received by the eyes of an observer located within the observation area, and the first field-of-view image and the second field-of-view image have at least partially different field-of-view coverage in the observer's field of vision.

[0006] Furthermore, the first field-of-view image and the second field-of-view image together form an extended display field of view in the observer's field of view; the angular coverage range of the extended display field of view in the observer's field of view is greater than the angular coverage range of the first display field of view formed by the first image light in the observer's field of view, and the angular coverage range of the extended display field of view in the observer's field of view is greater than the angular coverage range of the second display field of view formed by the second image light in the observer's field of view.

[0007] Furthermore, the first image source, the first light guide component, and the first reflective imaging area form a first display optical path, and the second image source, the second light guide component, and the second reflective imaging area form a second display optical path. The first display optical path and the second display optical path are arranged in a mirror image relative to an intermediate reference plane.

[0008] Further, the first light guide component includes a first polarization beam splitter and a first polarization conversion element, and the first reflective imaging region includes a first semi-transparent and semi-reflective surface; a first polarizing element is disposed between the first image source and the first polarization beam splitter, or the first image source is configured to output a first image light with a first predetermined polarization state, so that when the first image light first reaches the first polarization beam splitter, it has a polarization state reflected by the first polarization beam splitter; after being guided by the first light guide component, the first image light first reaches the first polarization beam splitter and is reflected by the first polarization beam splitter to the first semi-transparent and semi-reflective surface; after being reflected by the first semi-transparent and semi-reflective surface, the first image light reaches the first polarization beam splitter again, and then passes through the first polarization beam splitter into the observation area; the first polarization conversion element is disposed on the first image light propagation path between the first polarization beam splitter and the first semi-transparent and semi-reflective surface, for making the first image light reflected by the first semi-transparent and semi-reflective surface and returning to the first polarization beam splitter have a polarization state that passes through the first polarization beam splitter.

[0009] Further, the second light guide component includes a second polarization beam splitter and a second polarization conversion element, and the second reflective imaging region includes a second semi-transparent and semi-reflective surface; a second polarizing element is disposed between the second image source and the second polarization beam splitter, or the second image source is configured to output a second image light with a second predetermined polarization state, so that when the second image light first reaches the second polarization beam splitter, it has a polarization state reflected by the second polarization beam splitter; after being guided by the second light guide component, the second image light first reaches the second polarization beam splitter and is reflected by the second polarization beam splitter to the second semi-transparent and semi-reflective surface; after being reflected by the second semi-transparent and semi-reflective surface, the second image light reaches the second polarization beam splitter again, and then passes through the second polarization beam splitter into the observation area; the second polarization conversion element is disposed on the second image light propagation path between the second polarization beam splitter and the second semi-transparent and semi-reflective surface, for making the second image light reflected by the second semi-transparent and semi-reflective surface and returning to the second polarization beam splitter have a polarization state that passes through the second polarization beam splitter.

[0010] Furthermore, when the first polarizing element is disposed between the first image source and the first polarizing beam splitter, the first polarizing element includes a first linear polarizer, or a combination of a first linear polarizer and a third quarter-wave plate; when the second polarizing element is disposed between the second image source and the second polarizing beam splitter, the second polarizing element includes a second linear polarizer, or a combination of a second linear polarizer and a fourth quarter-wave plate.

[0011] Furthermore, the first light guide component includes a first total reflection surface, wherein the first image light undergoes at least one total reflection on the first total reflection surface before being incident on the first reflective imaging area; The second light guide component includes a second total reflection surface, wherein the second image light undergoes at least one total reflection on the second total reflection surface before being incident on the second reflective imaging area.

[0012] Furthermore, the first light guide assembly includes a plurality of first prisms, and the first polarizing beam splitting surface is disposed between two adjacent first prisms; The second light guide assembly includes a plurality of second prisms, and the second polarizing beam splitter is disposed between two adjacent second prisms; The first polarization beam-splitting surface is formed by a first polarization beam-splitting film layer deposited on the surface of the corresponding first prism, or the first polarization beam-splitting surface is formed by a first reflective polarization beam-splitting film attached to the surface of the corresponding first prism. The second polarization beam-splitting surface is formed by a second polarization beam-splitting film layer deposited on the surface of the corresponding second prism, or the second polarization beam-splitting surface is formed by a second reflective polarization beam-splitting film attached to the surface of the corresponding second prism.

[0013] Furthermore, the reflective imaging unit includes an integrally formed semi-transparent and semi-reflective optical element, wherein the first reflective imaging region and the second reflective imaging region are different regions of the semi-transparent and semi-reflective optical element; Alternatively, the reflective imaging unit includes a first semi-transparent and semi-reflective optical element and a second semi-transparent and semi-reflective optical element that are separately arranged from each other, with the first reflective imaging area formed on the first semi-transparent and semi-reflective optical element and the second reflective imaging area formed on the second semi-transparent and semi-reflective optical element.

[0014] The beneficial effects of the dual-screen optical device provided by this invention are as follows: Compared with the prior art, the dual-screen optical device provided by this invention allows a first image source to emit a first image light, which, after being guided by a first light guide component, can be incident on a first reflective imaging area of ​​a reflective imaging unit. The first reflective imaging area can reflect the first image light to the observation area, enabling the observer's eye within the observation area to receive the first image light and see a first field-of-view image. A second image source can emit a second image light, which, after being guided by a second light guide component, can be incident on a second reflective imaging area of ​​a reflective imaging unit. The second reflective imaging area can reflect the second image light to the observation area, allowing the observer's eye within the observation area to receive the first image light and see a first field-of-view image. Light is reflected into the observation area, allowing the observer's eye within the observation area to also receive the second image light and see the second field of view image. Since both the first and second field of view images can enter the observation area, the observer's eye can receive the images formed by the two image lights within the observation area. Furthermore, the first and second field of view images have at least partially different field of view coverage in the observer's field of view, so that the dual-screen optical device does not need to rely on only one image light to form the entire display range. In other words, by forming first and second field of view images with different field of view coverage ranges through the first and second image sources respectively, the field of view angle is significantly expanded. Attached Figure Description

[0015] Figure 1 A schematic diagram of the dual-screen optical device provided in the embodiments of the present invention. Figure 1 ; Figure 2 A schematic diagram of the dual-screen optical device provided in the embodiments of the present invention. Figure 2 ; Figure 3 A schematic diagram of the dual-screen optical device provided in the embodiments of the present invention. Figure 3 ; Figure 4 A schematic diagram of the dual-screen optical device provided in the embodiments of the present invention. Figure 4; Figure 5 A schematic diagram of the dual-screen optical device provided in the embodiments of the present invention. Figure 5 ; Figure 6 A schematic diagram of the dual-screen optical device provided in the embodiments of the present invention. Figure 6 ; Figure 7 A schematic diagram of the dual-screen optical device provided in the embodiments of the present invention. Figure 7 ; Figure 8 Provided for embodiments of the present invention Figure 7 A schematic diagram of the optical transfer function (MTF) of a dual-screen optical device.

[0016] The following are the labeling elements in the figure: X1 - First image source; X2 - Second image source; L1 - First prism; L11 - First polarization beam splitter; L12 - First total internal reflection surface; L2 - Second prism; L21 - Second polarization beam splitter; L22 - Second total internal reflection surface; L3 - Third prism; T1 - Reflection imaging unit; T11 - First reflection imaging area; T12 - Second reflection imaging area; G - Observation area; H1 - First lens; H2 - Second lens. Detailed Implementation

[0017] It should be noted that the specific embodiments are only used to explain the present invention and are not intended to limit the present invention.

[0018] It should be noted that, in the description of the embodiments of this application, unless otherwise stated, " / " means "or". For example, A / B can mean A or B. The "and / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Here, A and B can be singular or plural, respectively.

[0019] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as "connected to" or "attached to" another component, it can be directly connected to or indirectly connected to that other component. When a component is referred to as "fixed to" or "set on" another component, it can be directly on or indirectly on that other component.

[0020] It should be noted that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present 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, they should not be construed as limitations on the present invention.

[0021] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Features specified as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0022] It should be noted that the term "multiple" means two or more, unless otherwise explicitly specified.

[0023] Please refer to the following: Figure 1 The dual-screen optical device provided by the present invention will now be described. The dual-screen optical device includes: a first image source X1, a second image source X2, a first light guide component, a second light guide component, a reflective imaging unit T1, and an observation area G for an observer's eye to receive image light; the first image source X1 is used to emit first image light, which is guided sequentially by the first light guide component and then incident on the first reflective imaging area T11 of the reflective imaging unit T1, and after being reflected by the first reflective imaging area T11, enters the observation area G to form a first field-of-view image; the second image source X2 is used to emit second image light, which is guided sequentially by the second light guide component and then incident on the second reflective imaging area T12 of the reflective imaging unit T1, and after being reflected by the second reflective imaging area T12, enters the observation area G to form a second field-of-view image; wherein, both the first field-of-view image and the second field-of-view image can be received by the observer's eye located within the observation area G, and the first field-of-view image and the second field-of-view image have at least partially different field-of-view coverage ranges in the observer's field of vision.

[0024] Thus, the first image source X1 can emit a first image light, which, after being guided by the first light guide component, can be incident on the first reflective imaging area T11 of the reflective imaging unit T1. The first reflective imaging area T11 can reflect the first image light to the observation area G, so that the eye of the observer located in the observation area G can receive the first image light and see the first field of view image; the second image source X2 can emit a second image light, which, after being guided by the second light guide component, can be incident on the second reflective imaging area T12 of the reflective imaging unit T1. The second reflective imaging area T12 can reflect the second image light to the observation area G, so that the eye of the observer located in the observation area G can receive the first image light and see the first field of view image. The observer's eye, located within the observation area G, can also receive the second image light and see the second field of view image. Since both the first and second field of view images can enter the observation area G, the observer's eye can receive the images formed by the two image lights within the observation area G. Furthermore, the first and second field of view images have at least partially different field of view coverage in the observer's field of view, so that the dual-screen optical device does not need to rely on only one image light to form the entire display range. In other words, by forming the first and second field of view images with different field of view coverage ranges through the first image source X1 and the second image source X2 respectively, the field of view angle is significantly expanded.

[0025] In one embodiment, the observation area G can be a space for the eye to be placed.

[0026] Further, please refer to Figure 1 As a specific embodiment of the dual-screen optical device provided by the present invention, the first field-of-view image and the second field-of-view image together form an extended display field of view in the observer's field of view; the angular coverage range of the extended display field of view in the observer's field of view is greater than the angular coverage range of the first display field of view formed by the first image light in the observer's field of view, and the angular coverage range of the extended display field of view in the observer's field of view is greater than the angular coverage range of the second display field of view formed by the second image light in the observer's field of view.

[0027] Thus, both the first and second field-of-view images can be received by the observer's eye, and the first and second field-of-view images can jointly form an extended display field of view in the observer's field of vision. The first display field of view formed solely by the first image light has an angular coverage range, and the second display field of view formed solely by the second image light also has an angular coverage range. When the first and second field-of-view images jointly form an extended display field of view, the angular coverage range of the extended display field of view in the observer's field of vision is greater than that of the first display field of view, and the angular coverage range of the extended display field of view in the observer's field of vision is also greater than that of the second display field of view. That is, the first and second field-of-view images can jointly form a display field of view with a larger angular coverage range. In this way, the display range that the observer can see can be expanded by the joint use of two image lights, reducing the problem of limited field of view when a single image source forms a display field of view.

[0028] Further, please refer to Figure 1 As a specific embodiment of the dual-screen optical device provided by the present invention, the first field-of-view image and the second field-of-view image are adjacent, partially overlapping or separated from each other in the observer's field of vision.

[0029] Thus, the first and second field-of-view images can be positioned adjacent to each other, partially overlap, or be separated from each other in the observer's field of view, allowing them to form different field-of-view positional relationships according to different display requirements. When the first and second field-of-view images are adjacent in the observer's field of view, they can each occupy different field-of-view coverage areas, facilitating the formation of continuous or near-continuous display areas in the observer's field of view. When the first and second field-of-view images partially overlap in the observer's field of view, they have both a shared coverage area and distinct coverage areas, improving the transition effect between the two field-of-view images. When the first and second field-of-view images are separated in the observer's field of view, they can still provide display content at different positions, ensuring that the observer's eyes can still receive two image information streams within the observation area G.

[0030] Further, please refer to Figure 1 As a specific embodiment of the dual-screen optical device provided by the present invention, the first image source X1, the first light guide component and the first reflective imaging area T11 form a first display optical path, and the second image source X2, the second light guide component and the second reflective imaging area T12 form a second display optical path; the first display optical path and the second display optical path are arranged in a mirror image with respect to an intermediate reference plane.

[0031] Thus, the first image source X1, the first light guide component, and the first reflective imaging area T11 can correspondingly form the first display light path; the second image source X2, the second light guide component, and the second reflective imaging area T12 can correspondingly form the second display light path; the first image light can enter the observation area G after propagating along the first display light path, and the second image light can also enter the observation area G after propagating along the second display light path; the first display light path and the second display light path are arranged in a mirror image relative to the intermediate reference plane, making the first display light path and the second display light path more corresponding and coordinated in structural arrangement.

[0032] In one embodiment, the reference plane is a horizontal plane.

[0033] In one embodiment, the reference plane is located between the first image source X1 and the second image source X2.

[0034] Further, please refer to Figure 1 As a specific embodiment of the dual-screen optical device provided by the present invention, the first light guide component includes a first polarization beam splitter L11 and a first polarization conversion element; the first reflection imaging region T11 includes a first semi-transparent and semi-reflective surface; a first polarizing element is disposed between the first image source X1 and the first polarization beam splitter L11, or the first image source X1 is configured to output a first image light with a first predetermined polarization state, so that when the first image light first reaches the first polarization beam splitter L11, it has a polarization state reflected by the first polarization beam splitter L11; the first image light passes through the first light guide component. After being guided, the first image light reaches the first polarization beam splitter L11 for the first time and is reflected by the first polarization beam splitter L11 to the first semi-transparent and semi-reflective surface. After being reflected by the first semi-transparent and semi-reflective surface, the first image light reaches the first polarization beam splitter L11 again and then enters the observation area G through the first polarization beam splitter L11. The first polarization conversion element is disposed on the first image light propagation path between the first polarization beam splitter L11 and the first semi-transparent and semi-reflective surface, and is used to make the first image light reflected by the first semi-transparent and semi-reflective surface and returning to the first polarization beam splitter L11 have a polarization state that passes through the first polarization beam splitter L11.

[0035] Thus, the first image light emitted by the first image source X1 is reflected by the first polarization beam splitter L11, passes through the first polarization conversion element, is reflected by the first semi-transparent and semi-reflective surface, passes through the first polarization conversion element again, passes through the first polarization beam splitter L11, and then reaches the observation area G. Specifically, the first image light is first reflected at the first polarization beam splitter L11 and passes through the first polarization beam splitter L11 when it reaches the first polarization beam splitter L11 again. The first polarization beam-splitting surface L11 is not an ordinary reflecting surface that can only reflect the first image light. Instead, it can reflect or transmit the first image light according to the polarization state of the first image light. When the first image light first arrives at the first polarization beam-splitting surface L11, if the first image light has a polarization state that can be reflected by the first polarization beam-splitting surface L11, then the first image light can be reflected by the first polarization beam-splitting surface L11. When the first image light is reflected by the first semi-transparent and semi-reflective surface and returns to the first polarization beam-splitting surface L11, if the polarization state of the first image light has been converted to a polarization state that can be transmitted through the first polarization beam-splitting surface L11, then the first image light can pass through the first polarization beam-splitting surface L11 and enter the observation area G. In other words, the same first polarization beam-splitting surface L11 can first reflect the first image light in the same first image light path and then allow the first image light to pass through.

[0036] The first light guide assembly includes a first polarization beam splitter L11 and a first polarization conversion element; the first reflective imaging region T11 includes a first semi-transparent and semi-reflective surface; after the first image source X1 emits first image light, the first image light is guided by the first light guide assembly and reaches the first polarization beam splitter L11 for the first time; in order to enable the first image light to be reflected when it first reaches the first polarization beam splitter L11, a first polarizing element is disposed between the first image source X1 and the first polarization beam splitter L11, or the first image source X1 is configured to output first image light with a first predetermined polarization state; thus, the first image light reaches the first polarization beam splitter for the first time. When the first polarizing beam splitter L11 is in a polarization state that can be reflected by the first polarizing beam splitter L11, the first image light can be reflected by the first polarizing beam splitter L11 to the first semi-transparent and semi-reflective surface. For example, the first polarizing beam splitter L11 can reflect the first image light in one linear polarization state and transmit the first image light in another linear polarization state. At this time, the first predetermined polarization state output by the first polarizing element or the first image source X1 can make the first image light be in a reflectable polarization state when it first arrives at the first polarizing beam splitter L11, so that the first image light is reflected by the first polarizing beam splitter L11 to the first semi-transparent and semi-reflective surface.

[0037] After the first image light is reflected by the first polarization beam-splitting surface L11, it travels along the first image light propagation path to the first semi-transparent and semi-reflective surface, which then reflects the first image light back to the first polarization beam-splitting surface L11. A first polarization conversion element is disposed on the first image light propagation path between the first polarization beam-splitting surface L11 and the first semi-transparent and semi-reflective surface. The first polarization conversion element enables the first image light, after being reflected by the first semi-transparent and semi-reflective surface and returning to the first polarization beam-splitting surface L11, to have a polarization state that transmits through the first polarization beam-splitting surface L11. In other words, the first image light, during its propagation from the first polarization beam-splitting surface L11 to the first semi-transparent and semi-reflective surface, will pass through the first polarization beam-splitting surface L11. The first image light, after being reflected by the first semi-transparent and semi-reflective surface, will also pass through the first polarization conversion element again during its return from the first semi-transparent and semi-reflective surface to the first polarization beam splitter L11. After the first image light has traveled back and forth as described above, its polarization state is changed by the first polarization conversion element, so that the first image light is converted from a polarization state that can be reflected by the first polarization beam splitter L11 to a polarization state that can be transmitted through the first polarization beam splitter L11. Therefore, when the first image light reaches the first polarization beam splitter L11 for the second time, it is no longer reflected along the path it took when it first reached the first polarization beam splitter L11, but instead enters the observation area G through the first polarization beam splitter L11.

[0038] Further, please refer to Figure 1As a specific embodiment of the dual-screen optical device provided by the present invention, the second light guide component includes a second polarization beam splitter L21 and a second polarization conversion element; the second reflective imaging region T12 includes a second semi-transparent and semi-reflective surface; a second polarizing element is disposed between the second image source X2 and the second polarization beam splitter L21, or the second image source X2 is configured to output a second image light with a second predetermined polarization state, so that when the second image light first reaches the second polarization beam splitter L21, it has a polarization state reflected by the second polarization beam splitter L21; the second image light passes through the second light guide component. After being guided, the second image light first reaches the second polarization beam splitter L21 and is reflected by the second polarization beam splitter L21 to the second semi-transparent and semi-reflective surface. After being reflected by the second semi-transparent and semi-reflective surface, the second image light reaches the second polarization beam splitter L21 again and then enters the observation area G through the second polarization beam splitter L21. The second polarization conversion element is disposed on the second image light propagation path between the second polarization beam splitter L21 and the second semi-transparent and semi-reflective surface, and is used to make the second image light reflected by the second semi-transparent and semi-reflective surface and returning to the second polarization beam splitter L21 have a polarization state that passes through the second polarization beam splitter L21. Thus, the working principle of "the second image light emitted by the second image source X2 is reflected by the second polarization beam splitter L21, passes through the second polarization conversion element, is reflected by the second semi-transparent and semi-reflective surface, passes through the second polarization conversion element again, and reaches the observation area G after passing through the second polarization beam splitter L21" is the same as the working principle of "the first image light emitted by the first image source X1 is reflected by the first polarization beam splitter L11, passes through the first polarization conversion element, is reflected by the first semi-transparent and semi-reflective surface, passes through the first polarization conversion element again, and reaches the observation area G after passing through the first polarization beam splitter L11".

[0039] Further, please refer to Figure 1As a specific embodiment of the dual-screen optical device provided by the present invention, the first polarization conversion element includes a first quarter-wave plate, and the second polarization conversion element includes a second quarter-wave plate. Thus, when the first polarization conversion element is the first quarter-wave plate, if the first image light is S-polarized before first entering the quarter-wave plate, it can become circularly polarized after the first time it passes through the quarter-wave plate; after reaching the first semi-transparent and semi-reflective surface and being reflected by it, the first image light can become circularly polarized with the opposite polarization direction; when the first image light returns and passes through the same quarter-wave plate again, it can become P-polarized; thus, when the first image light returns to the first polarization beam-splitting surface L11, it has changed from an S-polarized state that could be reflected by the first polarization beam-splitting surface L11 to a P-polarized state that can pass through the first polarization beam-splitting surface L11; therefore, the first polarization beam-splitting surface L11 can reflect the first image light the first time it encounters it, and allows the first image light to pass through the first time it encounters it the second time. In addition, when the second polarization conversion element is a second quarter-wave plate, the working principle of the second quarter-wave plate can be referred to the working principle of the first quarter-wave plate.

[0040] Further, please refer to Figure 1 As a specific embodiment of the dual-screen optical device provided by the present invention, when a first polarizing element is disposed between the first image source X1 and the first polarizing beam splitter L11, the first polarizing element includes a first linear polarizer, or the first polarizing element includes a combination of a first linear polarizer and a third quarter-wave plate; when a second polarizing element is disposed between the second image source X2 and the second polarizing beam splitter L21, the second polarizing element includes a second linear polarizer, or the second polarizing element includes a combination of a second linear polarizer and a fourth quarter-wave plate. Thus, the light beam emitted by the first image source X1 can obtain linearly polarized light after passing through the first polarizing element, and the light beam emitted by the second image source X2 can obtain linearly polarized light after passing through the second polarizing element.

[0041] Further, please refer to Figure 1 As a specific embodiment of the dual-screen optical device provided by the present invention, the first light guide component includes a first total reflection surface L12, and the first image light undergoes at least one total reflection on the first total reflection surface L12 before being incident on the first reflection imaging region T11; the second light guide component includes a second total reflection surface L22, and the second image light undergoes at least one total reflection on the second total reflection surface L22 before being incident on the second reflection imaging region T12.

[0042] Thus, through the setting of the first total internal reflection surface L12 and the second total internal reflection surface L22, the first image light and the second image light can change their propagation direction in the corresponding light guide components before entering the corresponding reflection imaging areas. This allows the first image light to be guided by the first light guide component and then incident on the first reflection imaging area T11, and the second image light to be guided by the second light guide component and then incident on the second reflection imaging area T12. In other words, the first image light and the second image light can be guided by total internal reflection before reaching the corresponding reflection imaging areas, which facilitates the formation of two relatively independent display paths in the dual-screen optical device. The first image source X1, the first light guide component, and the first reflection imaging area T11 can cooperate to form a first field of view image, and the second image source X2, the second light guide component, and the second reflection imaging area T12 can cooperate to form a second field of view image, so that both the first field of view image and the second field of view image can be received by the observer's eye located in the observation area G.

[0043] Further, please refer to Figure 1 As a specific embodiment of the dual-screen optical device provided by the present invention, the first light guide component includes a plurality of first prisms L1, and a first polarizing beam splitting surface L11 is disposed between two adjacent first prisms L1; the second light guide component includes a plurality of second prisms L2, and a second polarizing beam splitting surface L21 is disposed between two adjacent second prisms L2; ​​the first polarizing beam splitting surface L11 is formed by a first polarizing beam splitting film layer deposited on the surface of the corresponding first prism L1, or the first polarizing beam splitting surface L11 is formed by a first reflective polarizing beam splitting film attached to the surface of the corresponding first prism L1; the second polarizing beam splitting surface L21 is formed by a second polarizing beam splitting film layer deposited on the surface of the corresponding second prism L2, or the second polarizing beam splitting surface L21 is formed by a second reflective polarizing beam splitting film attached to the surface of the corresponding second prism L2.

[0044] Thus, the first light guide assembly includes multiple first prisms L1, with a first polarizing beam splitter L11 disposed between two adjacent first prisms L1; the second light guide assembly includes multiple second prisms L2, with a second polarizing beam splitter L21 disposed between two adjacent second prisms L2; ​​the multiple first prisms L1 can form a solid optical structure for guiding first image light, and the multiple second prisms L2 can form a solid optical structure for guiding second image light; the first polarizing beam splitter L11 is disposed between two adjacent first prisms L1 to facilitate reflection and guidance of the first image light within the first light guide assembly; the second polarizing beam splitter L21 is disposed between two adjacent second prisms L2 to facilitate reflection and guidance of the second image light within the second light guide assembly; The first polarization beam-splitting surface L11 can be formed by a first polarization beam-splitting film layer or a first reflective polarization beam-splitting film; the second polarization beam-splitting surface L21 can be formed by a second polarization beam-splitting film layer or a second reflective polarization beam-splitting film; this provides a specific structure for the formation of the first polarization beam-splitting surface L11 and the second polarization beam-splitting surface L21; the first semi-transparent and semi-reflective surface can be formed by a first semi-transparent and semi-reflective film layer or a first semi-transparent and semi-reflective film; the second semi-transparent and semi-reflective surface can be formed by a second semi-transparent and semi-reflective film layer or a second semi-transparent and semi-reflective film; this enables the first reflective imaging region T11 and the second reflective imaging region T12 to reflect the first image light and the second image light respectively through the corresponding semi-transparent and semi-reflective structures.

[0045] Further, please refer to Figure 1 As a specific embodiment of the dual-screen optical device provided by the present invention, the reflective imaging unit T1 includes an integrated semi-transparent and semi-reflective optical component, and the first reflective imaging area T11 and the second reflective imaging area T12 are different areas of the integrated semi-transparent and semi-reflective optical component; or, the reflective imaging unit T1 includes a first semi-transparent and semi-reflective optical component and a second semi-transparent and semi-reflective optical component that are separately arranged from each other, the first reflective imaging area T11 is formed on the first semi-transparent and semi-reflective optical component, and the second reflective imaging area T12 is formed on the second semi-transparent and semi-reflective optical component.

[0046] Thus, when an integrated semi-transparent and semi-reflective optical element is used, the first reflective imaging area T11 and the second reflective imaging area T12 are located in different areas of the same semi-transparent and semi-reflective optical element, which facilitates the reflective imaging unit T1 to carry the reflective imaging function of two image lights through the same structure; when a first semi-transparent and semi-reflective optical element and a second semi-transparent and semi-reflective optical element are used separately, the first reflective imaging area T11 and the second reflective imaging area T12 are formed on different semi-transparent and semi-reflective optical elements, which facilitates the first image light and the second image light to be reflected by the corresponding semi-transparent and semi-reflective optical elements respectively.

[0047] Further, please refer to Figure 1As a specific embodiment of the dual-screen optical device provided by the present invention, the vertical direction when the observer wears the dual-screen optical device is taken as the up-down direction, and the horizontal direction when the observer wears the dual-screen optical device is taken as the left-right direction; the first field of view image corresponds to the upper field of view area in the extended display field of view, and the second field of view image corresponds to the lower field of view area in the extended display field of view; or, the first field of view image corresponds to the left field of view area in the extended display field of view, and the second field of view image corresponds to the right field of view area in the extended display field of view.

[0048] Thus, the first and second field-of-view images not only jointly form an extended display field of view, but also have a clear regional correspondence within the extended display field of view. When the first field-of-view image corresponds to the upper field-of-view region and the second field-of-view image corresponds to the lower field-of-view region, the extended display field of view can be provided by the first and second field-of-view images in the vertical direction. When the first field-of-view image corresponds to the left field-of-view region and the second field-of-view image corresponds to the right field-of-view region, the extended display field of view can be provided by the first and second field-of-view images in the horizontal direction. Since the angular coverage of the extended display field of view in the observer's field of view is greater than that of the first and second display fields of view, the setting of the upper, lower, left, and right field-of-view regions makes the distribution direction of the first and second field-of-view images in the extended display field of view clearer, facilitating the implementation of the extended display field of view through the configuration of field-of-view regions in different directions.

[0049] Further, please refer to Figure 4 As a specific embodiment of the dual-screen optical device provided by the present invention, the first total reflection surface L12 and the first polarization beam splitting surface L11 form a first included angle θ1, the second total reflection surface L22 and the second polarization beam splitting surface L21 form a second included angle θ2, and the first total reflection surface L12 and the second total reflection surface L22 form a third included angle θ3; wherein, 30°≤θ1≤70°, 30°≤θ2≤70°, and 130°≤θ3≤180°.

[0050] Thus, limiting θ3 to 130°≤θ3≤180° ensures that the image light emitted from the first image source X1 and the second image source X2 has a large incident angle when it first incident on the first total internal reflection surface L12 and the second total internal reflection surface L22. This facilitates meeting the total internal reflection condition and reduces the risk of light leakage, energy loss, or stray light due to the light not reaching the critical angle of total internal reflection. This ensures that the first and second image lights can be stably guided to their respective polarization beam splitters. Limiting θ1 and θ2 to 30°≤θ1≤70° and 30°≤θ2≤70° ensures that the incident angle of the image light on the first polarization beam splitter L11 and the second polarization beam splitter L21 is within a relatively reasonable range, avoiding a significant decrease in the beam splitting efficiency of the polarization beam splitting film due to an excessively large incident angle.

[0051] Further, please refer to Figure 4 As a specific embodiment of the dual-screen optical device provided by the present invention, it further includes: a prism assembly, a first lens H1, and a second lens H2 arranged sequentially along the direction away from the observation area G; the prism assembly includes a first prism L1, a second prism L2, and a third prism L3, a first polarizing beam-splitting surface L11 disposed between the first prism L1 and the third prism L3, a second polarizing beam-splitting surface L21 disposed between the third prism L3 and the second prism L2, a first semi-transparent and semi-reflective surface and a second semi-transparent and semi-reflective surface formed on the side of the first lens H1 away from the prism assembly, and the second lens H2 disposed on the side of the first lens H1 away from the observation area G. In one embodiment, taking the vertical direction when the observer wears the dual-screen optical device as the up-down direction, the aperture D1 of the side of the third prism L3 near the observation area G in the up-down direction is 16mm to 25mm, and the aperture D2 of the side of the second lens H2 away from the observation area G in the up-down direction is 18mm to 30mm. In one embodiment, the distance TTL between the surface of the third prism L3 near the observation area G and the surface of the second lens H2 away from the observation area G is 8 mm to 13 mm. In one embodiment, the diagonal length of the display area of ​​the first image source X1 and the second image source X2 is 0.4 inches to 0.7 inches. In one embodiment, the sag SAG of the surface of the first lens H1 away from the observation area G in the vertical direction is 0.5 mm to 1.5 mm.

[0052] Thus, by limiting the aperture D1 of the surface of the third prism L3 closest to the observation area G in the vertical direction to 16mm-25mm, and the aperture D2 of the surface of the second lens H2 furthest from the observation area G in the vertical direction to 18mm-30mm, it is possible to meet the required effective aperture for the large field-of-view image beam to pass through, while avoiding excessively large apertures of the prism and lens assemblies that would increase the module's size, weight, and assembly space, thereby balancing large field-of-view display with a slim and lightweight structure. By limiting the TTL between the surface of the third prism L3 closest to the observation area G and the surface of the second lens H2 furthest from the observation area G to 8mm-13mm, the overall length of the module along the optical axis can be controlled, allowing the module to maintain a short overall length while achieving a large field-of-view display, which is beneficial for slim and lightweight design. By limiting the diagonal length of the display areas of the first image source X1 and the second image source X2 to 0.4 inches-0.7 inches, it is possible to avoid increasing power consumption, heat generation, and module size due to the use of excessively large displays. By limiting the vertical sag SAG of the surface of the first lens H1 away from the observation area G to 0.5mm to 1.5mm, the curvature of the surface related to the reflection imaging of the first lens H1 can be limited, so that the surface has appropriate optical power to meet the requirements of image light reflection imaging and aberration correction; at the same time, excessive surface curvature is avoided to prevent lens processing difficulties.

[0053] In one embodiment, the unit of optical power in this application is mm⁻¹.

[0054] Further, please refer to Figure 4 As a specific embodiment of the dual-screen optical device provided by the present invention, the optical surface of the first prism L1 near the first image source X1 is a curved surface with an optical power of 0.018 to 0.022; the optical surface of the second prism L2 near the second image source X2 is a curved surface with an optical power of 0.018 to 0.022.

[0055] Thus, by limiting the optical power of the curved surface to 0.018 to 0.022, the light can be appropriately bent and pre-corrected in the initial stage when the image light enters the prism assembly. This optical power range can retain a certain refractive power while avoiding excessive curvature of the curved surface, which would make prism processing difficult.

[0056] Further, please refer to Figure 4As a specific embodiment of the dual-screen optical device provided by the present invention, a first correction lens or a first adjustment lens group is disposed between the first image source X1 and the first prism L1, and a second correction lens or a second adjustment lens group is disposed between the second image source X2 and the second prism L2. In one embodiment, the combined optical power of the first correction lens or the first adjustment lens group is 0.01 to 0.03. In one embodiment, the combined optical power of the second correction lens or the second adjustment lens group is 0.01 to 0.03. In one embodiment, the third prism L3 has a light-emitting optical surface facing the observation area G, the light-emitting optical surface is curved, and the optical power of the light-emitting optical surface is 0.005 to 0.02.

[0057] Thus, by limiting the combined optical power of a single lens or lens group to 0.01–0.03, pre-shaping, collimating, or converging adjustments can be made to the image light emitted from the image source, allowing the image light to enter the prism assembly with a more suitable divergence angle and incident position. By limiting the optical power of the curved surface of the third prism L3 to 0.005–0.02, the propagation direction of the light can be corrected before the image light exits to the observation area G, improving aberrations, field curvature, or distortion in the edge region of a large field of view. This makes it easier for the first and second image lights entering the observation area G to form clear and stable first and second field-of-view images. At the same time, this optical power range can avoid excessive curvature of the optical surface on the light-emitting side, thereby reducing the difficulty of prism manufacturing.

[0058] In the first embodiment, please refer to Figure 2 The first image source X1 (i.e., image source 1) and the second image source X2 (i.e., image source 2) are located at the top and bottom ends, respectively. The light emitted from the first image source X1 undergoes total internal reflection at surface S001 and then reflects again at surface S002. Surface S002 can be coated with a polarizing beam splitter layer, or a reflective polarizing beam splitter film can be attached, or other methods can be used to achieve the function of transmitting and reflecting light. The light reflected by S002 is reflected again by S003. S003 can be coated with a semi-transparent and semi-reflective film layer to achieve the function of reflection and transmission. The light reflected by S003 re-enters S002, and then enters the human eye after passing through S002, where it appears as an image magnified by the module. A quarter-wave plate is also needed to achieve the above optical path between S002 and S003.

[0059] The second image source X2 is placed as a mirror image of the first image source X1, and its optical path is also consistent with that of the first image source X1. The entire optical module structure is also a symmetrical structure. At this time, the image of the second image source X2 is magnified by the module and enters the human eye.

[0060] The first image source X1 is magnified by the module to form the image of the upper half of the field of view, and the second image source X2 is magnified by the module to form the image of the lower half of the field of view. The upper and lower halves of the field of view are stitched together to form a single image, thereby doubling the field of view.

[0061] Where θ1 and θ2 ≤ 90°, θ3 ≥ 90°, and the angle between the optical axis of surface S003 and surface S002 ≥ 90°.

[0062] In one embodiment, such as Figure 3 As shown, the dual-screen optical device also needs to see the external scene clearly. In order to prevent the external scene from being distorted after passing through the module, a compensation lens needs to be added.

[0063] In the first embodiment, the optical module of the dual-screen optical device can be divided into, as follows: Figure 4 The system comprises five components. To achieve the given optical effect, a polarizing beam-splitting layer needs to be sandwiched between the first prism L1 and the third prism L3, and also between the third prism L3 and the second prism L2. As mentioned above, the polarizing beam-splitting layer can be achieved by depositing a film or attaching a polarizing beam-splitting plate. A certain air gap is required between the first prism L1, the third prism L3, and the first lens H1 to achieve total internal reflection. The curved surface of the first lens H1 needs to achieve a semi-transparent, semi-reflective effect, which can be achieved by depositing a semi-transparent, semi-reflective film or attaching a film; the method is not limited. A quarter-wave plate is required between the polarizing beam-splitting film and the semi-transparent, semi-reflective film to allow light to pass through the polarizing beam-splitting layer and enter the human eye after reflection by the semi-transparent, semi-reflective film. An air gap can be left between the first lens H1 and the second lens H2, or they can be glued together using adhesive bonding or optical bonding processes.

[0064] In the second embodiment, the second embodiment is a variation of the first embodiment, such as... Figure 5 As shown, to improve the optical performance of the module, S101, S103, and S104 can be curved surfaces (unrestricted by concavity or convexity, spherical or aspherical surfaces, etc.), increasing design variables and improving optical performance. Because S103 is curved, to prevent distortion of the external scene, the S108 surface in the compensating mirror needs to be curved accordingly, ensuring that the optical power directly transmitted through the module is 0. Furthermore, for ease of processing and bonding, the first prism L1 and the second prism L2 can have S102 and S105 parallel to each other, or an additional S106 surface can be added for easier processing. Because S102 and S105 are parallel, S107 also needs to be parallel.

[0065] In the third embodiment, as Figure 6 As shown, to improve optical performance, lenses 11, 12, and 13 can be added. Because lens 12 is added, the S201 surface in the compensating mirror needs to be curved to ensure a distortion-free view of the external scene, making the optical power directly transmitted through the module zero. Additionally, for manufacturing considerations, the original... Figure 4In this embodiment, lens 1 is disassembled into prism 14 and lens 15. Prism 14 and lens 15 can be glued together or have an air gap. Furthermore, this position also satisfies the above-mentioned polarizing beam splitting film and semi-transparent and semi-reflective film. Therefore, a quarter-wave plate can also be added between prism 14 and lens 15.

[0066] It should be noted that the deformation methods such as adding lenses and curved surfaces in the second and third embodiments to improve performance and facilitate processing can be used in combination and superimposed.

[0067] In the fourth embodiment, Figure 7 and Figure 8 As a practical design example, the field of view is ≥70°. While achieving a large field of view, the optical effect is also very good, with MTF ≥0.5@40lp / mm.

[0068] To achieve the desired optical path effect, the film design can be varied, as explained below. Surface S305 needs to be coated with a semi-transparent, semi-reflective film to achieve both reflection and transmission. Polarization and beam splitting are required at S302, which can be achieved by coating or attaching a film. It should be noted that S302 consists of two adjacent surfaces, the first prism L1 and the third prism L3, bonded together or with an air gap; therefore, coating or attaching a film can be done on either of these two adjacent surfaces. S303 is treated similarly to S302. To allow light reflected from S305 to pass through S302 and enter the eye, a quarter-wave plate needs to be attached between S302 and S305. Figure 7 There are two possible locations for the solution: Location 1: Place it at S302, sandwiched between the polarizing beam splitter and the semi-transparent, semi-reflective film; Location 2: Place it at S304, and to avoid affecting total internal reflection, it should be placed on the lens side of S304. Additionally, to achieve the desired optical path effect, polarization is required between the screen and the polarizing beam splitter, for example, by attaching a polarizing film to the screen. It should be noted that if the quarter-wave plate is attached at location 1, the light reaching location 1 needs to be circularly polarized to achieve the desired effect; therefore, a polarizing film plus a quarter-wave plate is needed between the screen and the polarizing beam splitter. If the quarter-wave plate is attached at location 2, the light reaching location 2 needs to be linearly polarized to achieve the desired effect; therefore, a linearly polarizing film is sufficient between the screen and the polarizing beam splitter. S303 is treated similarly to S302.

[0069] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

Claims

1. A dual-screen optical device, characterized in that, include: A first image source, a second image source, a first light guide assembly, a second light guide assembly, a reflective imaging unit, and an observation area for the observer's eye to receive image light; The first image source is used to emit first image light. The first image light is guided by the first light guide component and then incident on the first reflection imaging area of ​​the reflection imaging unit. After being reflected by the first reflection imaging area, it enters the observation area to form a first field of view image. The second image source is used to emit a second image light, which is guided by the second light guide component and then incident on the second reflection imaging area of ​​the reflection imaging unit. After being reflected by the second reflection imaging area, it enters the observation area to form a second field of view image. Both the first field-of-view image and the second field-of-view image can be received by the eyes of an observer located within the observation area, and the first field-of-view image and the second field-of-view image have at least partially different field-of-view coverage in the observer's field of vision.

2. The dual-screen optical device as described in claim 1, characterized in that, The first field-of-view image and the second field-of-view image together form an extended display field of view in the observer's field of view; the angular coverage range of the extended display field of view in the observer's field of view is greater than the angular coverage range of the first display field of view formed by the light of the first image in the observer's field of view, and the angular coverage range of the extended display field of view in the observer's field of view is greater than the angular coverage range of the second display field of view formed by the light of the second image in the observer's field of view.

3. The dual-screen optical device as described in claim 1, characterized in that, The first image source, the first light guide component, and the first reflective imaging area form a first display optical path, and the second image source, the second light guide component, and the second reflective imaging area form a second display optical path. The first display optical path and the second display optical path are arranged in a mirror image relative to an intermediate reference plane.

4. The dual-screen optical device as described in any one of claims 1 to 3, characterized in that, The first light guide component includes a first polarization beam splitter and a first polarization conversion element; the first reflective imaging region includes a first semi-transparent and semi-reflective surface; a first polarizing element is disposed between the first image source and the first polarization beam splitter, or the first image source is configured to output a first image light with a first predetermined polarization state, so that when the first image light first reaches the first polarization beam splitter, it has a polarization state reflected by the first polarization beam splitter; after being guided by the first light guide component, the first image light first reaches the first polarization beam splitter and is reflected by the first polarization beam splitter to the first semi-transparent and semi-reflective surface; after being reflected by the first semi-transparent and semi-reflective surface, the first image light reaches the first polarization beam splitter again, and then passes through the first polarization beam splitter into the observation area; the first polarization conversion element is disposed on the first image light propagation path between the first polarization beam splitter and the first semi-transparent and semi-reflective surface, and the first polarization conversion element is used to make the first image light reflected by the first semi-transparent and semi-reflective surface and returning to the first polarization beam splitter have a polarization state that passes through the first polarization beam splitter.

5. The dual-screen optical device as described in claim 4, characterized in that, The second light guide component includes a second polarization beam splitter and a second polarization conversion element; the second reflective imaging region includes a second semi-transparent and semi-reflective surface; a second polarizing element is disposed between the second image source and the second polarization beam splitter, or the second image source is configured to output a second image light with a second predetermined polarization state, so that when the second image light first reaches the second polarization beam splitter, it has a polarization state reflected by the second polarization beam splitter; after being guided by the second light guide component, the second image light first reaches the second polarization beam splitter and is reflected by the second polarization beam splitter to the second semi-transparent and semi-reflective surface; after being reflected by the second semi-transparent and semi-reflective surface, the second image light reaches the second polarization beam splitter again, and then passes through the second polarization beam splitter into the observation area; the second polarization conversion element is disposed on the second image light propagation path between the second polarization beam splitter and the second semi-transparent and semi-reflective surface, and the second polarization conversion element is used to make the second image light reflected by the second semi-transparent and semi-reflective surface and returning to the second polarization beam splitter have a polarization state that passes through the second polarization beam splitter.

6. The dual-screen optical device as described in claim 5, characterized in that, When the first polarizing element is disposed between the first image source and the first polarizing beam splitter, the first polarizing element includes a first linear polarizer, or the first polarizing element includes a combination of a first linear polarizer and a third quarter-wave plate; when the second polarizing element is disposed between the second image source and the second polarizing beam splitter, the second polarizing element includes a second linear polarizer, or the second polarizing element includes a combination of a second linear polarizer and a fourth quarter-wave plate.

7. The dual-screen optical device as described in claim 5, characterized in that, The first light guide component includes a first total reflection surface, wherein the first image light undergoes at least one total reflection on the first total reflection surface before being incident on the first reflective imaging area; The second light guide component includes a second total reflection surface, wherein the second image light undergoes at least one total reflection on the second total reflection surface before being incident on the second reflective imaging area.

8. The dual-screen optical device as described in claim 1, characterized in that, The reflective imaging unit includes an integrated semi-transparent and semi-reflective optical element, and the first reflective imaging area and the second reflective imaging area are different areas of the integrated semi-transparent and semi-reflective optical element. Alternatively, the reflective imaging unit includes a first semi-transparent and semi-reflective optical element and a second semi-transparent and semi-reflective optical element that are separately arranged from each other, with the first reflective imaging area formed on the first semi-transparent and semi-reflective optical element and the second reflective imaging area formed on the second semi-transparent and semi-reflective optical element.

9. The dual-screen optical device as described in claim 7, characterized in that, The first total internal reflection surface forms a first angle θ1 with the first polarization beam splitter, the second total internal reflection surface forms a second angle θ2 with the second polarization beam splitter, and the first total internal reflection surface forms a third angle θ3 with the second total internal reflection surface. Among them, 30°≤θ1≤70°, 30°≤θ2≤70°, and 130°≤θ3≤180°.

10. The dual-screen optical device as described in claim 5, characterized in that, Also includes: A prism assembly, a first lens, and a second lens are arranged sequentially along a direction away from the observation area; The prism assembly includes a first prism, a second prism, and a third prism. The first polarizing beam-splitting surface is disposed between the first prism and the third prism, and the second polarizing beam-splitting surface is disposed between the third prism and the second prism. The surface of the first lens away from the prism assembly forms a first semi-transparent and semi-reflective surface and a second semi-transparent and semi-reflective surface. The second lens is disposed on the side of the first lens away from the observation area. The optical surface of the first prism near the first image source is a curved surface with an optical power of 0.018 to 0.

022. The optical surface of the second prism near the second image source is a curved surface with an optical power of 0.018 to 0.022.

Images