Imaging optical system and display device

Abstract

The present invention discloses an imaging optical system and display device capable of increasing the field of view angle. The imaging optical system includes a flat lens and a reflective assembly. The reflective assembly has at least one pair of reflective surfaces, with the two reflective surfaces located on the image source side and the viewing side of the flat lens, respectively. The angles between the reflective surfaces and the flat lens are less than or equal to 90 degrees, the angles between the two reflective surfaces and the flat lens are equal, and the intersection lines between the two reflective surfaces and the flat lens are parallel and intersecting. This imaging optical system can increase the field of view angle. This increase in the field of view angle allows for a wider audience to view, thereby improving imaging quality.

Description

[0001] This application is a divisional application with the application date of "2021-06-09", application number "2021106440414", and application name "Imaging Optical System and Display Device". Technical Field

[0002] The present invention relates to the field of optical equipment manufacturing, and in particular to an imaging optical system and a display device capable of increasing the field of view angle. Background Art

[0003] A flat lens utilizes two layers of periodically distributed, orthogonal arrayed optical waveguides, causing light to undergo a total internal reflection in each of the two layers. Due to the orthogonal rectangular structure, the angle of incidence during the first total internal reflection is the same as the angle of exit during the second total internal reflection. After passing through the flat lens, all light rays within the divergence angle of the light source converge to a spatial position symmetrical to the flat surface of the light source, resulting in a 1:1 floating real image. However, this existing imaging structure has some drawbacks, such as a small viewing angle on the viewing side. If the viewer deviates from the central axis of the flat lens by a certain angle, the real image will not be visible. Flat lenses with this characteristic are not suitable for public areas for display purposes, so developing a method to increase the viewing angle of flat lenses is particularly important.

[0004] Conventional methods for increasing viewing angles in existing technologies can sometimes cause image distortion, some are difficult to deploy in public areas due to their complex structures and high costs, and some offer only limited increases in viewing angle, rendering them useless. One area of ​​research in this field is to find ways to significantly increase the viewing angle of flat lenses using simple structures. Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides an imaging optical system that increases the viewing angle of a flat lens with a simple structure.

[0006] Another object of the present invention is to provide a display device having the above-mentioned imaging optical system.

[0007] An imaging optical system according to an embodiment of the present invention includes: a flat plate lens, the flat plate lens including two groups of optical waveguide arrays, each group of the optical waveguide arrays consisting of a single column and multiple rows of sub-waveguides with rectangular cross-sections, the two groups of optical waveguide arrays including: a first optical waveguide array and a second optical waveguide array, the sub-waveguides of the first optical waveguide array extending along the X direction and forming multiple rows along the Y direction, the sub-waveguides of the second optical waveguide array extending along the Y direction and forming multiple rows along the X direction, the first optical waveguide array and the second optical waveguide array arranged along the Z direction, the X direction, the Y direction, and the Z direction being perpendicular to each other. The flat lens has a central normal, the central normal passes through the center of the flat lens and is parallel to the Z direction, and the opposite sides of the flat lens are respectively an image source side and a viewing side; a reflective component, the reflective component has at least one pair of reflective surfaces, the two reflective surfaces in the same pair are respectively located on the image source side and the viewing side, the reflective surfaces are both planes and are arranged toward the central normal, the angles between the reflective surfaces and the flat lens are less than or equal to 90 degrees, wherein the angles between the two reflective surfaces in the same pair and the flat lens are equal, and the intersection lines of the two reflective surfaces in the same pair and the flat lens are parallel to each other.

[0008] According to an embodiment of the present invention, the imaging optical system employs reflective surfaces on both the image source side and the viewing side of the flat-panel lens, with the reflective surfaces arranged in pairs. This allows the reflective surfaces to increase the field of view, with some solutions even extending the field of view to 180 degrees. This increased field of view allows for greater viewing angles when viewers view the floating image from the viewing side. This allows the imaging optical system to be used in public areas for exhibition purposes, transcending the limitations of a single flat-panel lens. Furthermore, by reflecting light from the reflective surfaces, the utilization rate of light at the edge of the light source can be increased, allowing more light to be directed toward the floating image. This enhances the brightness and clarity of the floating image, improving imaging quality.

[0009] In some embodiments, one side of the reflective surface is attached to the flat lens.

[0010] In some embodiments, the reflective component has multiple pairs of reflective surfaces, and the multiple pairs of reflective surfaces are arranged along a direction surrounding the central normal.

[0011] Specifically, the multiple pairs of reflective surfaces include two pairs located on opposite sides of the center normal; in the two pairs of reflective surfaces located on opposite sides of the center normal, the angle between each reflective surface and the flat lens is equal, and the intersection line between each reflective surface and the flat lens is parallel to each other.

[0012] In some embodiments, the two reflecting surfaces in the same pair are symmetrically arranged relative to the flat lens.

[0013] In some embodiments, the reflective assembly includes at least two reflectors, each of which is a plane mirror, and a surface of each reflector facing the center normal constitutes the reflective surface.

[0014] A display device according to an embodiment of the present invention includes: the imaging optical system according to the above embodiment of the present invention; and a display, wherein the display is located on the image source side and the display screen of the display is arranged toward the flat lens.

[0015] The display device according to an embodiment of the present invention utilizes a pair of reflective surfaces on either side of the flat lens to increase the field of view. In some implementations, the reflective surfaces can even extend the field of view to 180 degrees. This increased field of view accommodates a wider audience when viewing the floating image from the viewing side, enabling the display device to be used in public areas for exhibition purposes, thus transcending the limitations of display devices. Furthermore, utilizing the reflective surfaces to reflect light improves the utilization of light from the edge of the light source, directing more light toward the floating image, thereby enhancing image quality.

[0016] In some specific embodiments, the display screen is a straight screen, the angle between the display screen and the flat-panel lens is an acute angle, the four sides of the display screen are respectively a near side, a far side, and two inclined sides, the near side and the far side are opposite sides of the display screen, and the near side is located on the side of the display screen adjacent to the flat-panel lens; on the image source side, the reflective surfaces are respectively provided on both sides of the display screen corresponding to the two inclined sides, and / or the reflective surface is provided on the side of the display screen corresponding to the far side.

[0017] In some optional embodiments, the reflective surface corresponding to the inclined edge is a first vision-enhancing reflective surface, and the projection of the display screen formed in a direction parallel to the flat lens is completely located within the first vision-enhancing reflective surface.

[0018] Specifically, the first vision-enhancing reflective surface is triangular or trapezoidal, and a projection of the display screen along a direction parallel to the flat lens is flush with one side of the first vision-enhancing reflective surface.

[0019] Furthermore, the reflective surface corresponding to the far edge is a second vision-enhancing reflective surface, and the second vision-enhancing reflective surface is rectangular.

[0020] Optionally, the first vision-enhancing reflective surface is triangular; the projection of the display screen along a direction parallel to the flat lens is flush with one side of the first vision-enhancing reflective surface; the projection of the second vision-enhancing reflective surface along a direction parallel to the flat lens is flush with the other side of the first vision-enhancing reflective surface.

[0021] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

[0023] Figure 1 It is a structural schematic diagram of an imaging optical system according to an embodiment of the present application.

[0024] Figure 2 This is a general structural diagram of a flat lens according to an embodiment of the present application.

[0025] Figure 3 yes Figure 2 A partial enlarged view of K in the side view.

[0026] Figure 4 1 is an exploded view of a flat lens according to an embodiment of the present application.

[0027] Figure 5 1 is a schematic structural diagram of a two-layer orthogonal optical waveguide array along the Z direction according to an embodiment of the present application.

[0028] Figure 6 Schematic diagram of imaging of a two-layer orthogonal optical waveguide array according to an embodiment of the present application.

[0029] Figure 7 FIG. 1 is a schematic diagram of imaging in the X direction when a light source image passes through a single-layer optical waveguide array according to an embodiment of the present application.

[0030] Figure 8 yes Figure 7 The diagram shows the imaging of a light source image in a three-dimensional direction when the light source image passes through a single-layer optical waveguide array.

[0031] Figure 9 This is a principle diagram of the imaging optical path when a light source image passes through two layers of orthogonal optical waveguide arrays according to an embodiment of the present application.

[0032] Figure 10 is a schematic structural diagram of the first display device in Example 1 of the present application;

[0033] Figure 11 This is a schematic diagram of the principle of expanding the horizontal field of view of the first display device in Example 1 of the present application;

[0034] Figure 12 is a schematic structural diagram of the second display device in Example 2 of the present application;

[0035] Figure 13 2 is a schematic diagram showing the principle of expanding the horizontal field of view of the second display device in Example 2 of the present application;

[0036] Figure 14 is a schematic structural diagram of the third display device in Example 3 of the present application;

[0037] Figure 15 2 is a schematic diagram of the principle of expanding the vertical field of view of the third display device in Example 3 of the present application;

[0038] Figure 16 is a schematic structural diagram of the fourth display device in Example 4 of the present application;

[0039] Figure 17 2 is a schematic diagram showing the principle of expanding the vertical field of view of the fourth display device in Example 4 of the present application;

[0040] Figure 18 2 is a schematic diagram showing the principle of expanding the vertical field of view of the fourth display device in Example 4 of the present application when γ=90°;

[0041] Figure 19 2 is a schematic diagram showing the principle of expanding the vertical field of view of the fourth display device in Example 4 of the present application when γ>90°;

[0042] Figure 20 is a schematic structural diagram of the fifth display device in Example 5 of the present application;

[0043] Figure 21 is a side view of the fifth display device in Example 5 of the present application;

[0044] Figure 22 It is a structural schematic diagram of a display device according to another embodiment of the present application.

[0045] Reference numerals:

[0046] 1000. Display device;

[0047] 1000A, a first display device; 1000B, a second display device; 1000C, a third display device; 1000D, a fourth display device; 1000E, a fifth display device;

[0048] 100. Imaging optical system;

[0049] 1. Flat lens;

[0050] 10. Optical waveguide array; 11. First optical waveguide array; 12. Second optical waveguide array;

[0051] 101, sub-waveguide;

[0052] 30. Protective cover; 31. First cover; 32. Second cover;

[0053] L1, center normal;

[0054] 5. Reflection component;

[0055] 50. Reflector; 51. Plane mirror; 52. Prism;

[0056] 5s, reflecting surface; 5s-1, first vision-enhancing reflecting surface; 5s-2, second vision-enhancing reflecting surface;

[0057] 200, display;

[0058] 210, display screen; 211, near edge; 212, far edge; 213, tilted edge;

[0059] P1, image; P2, floating real image. DETAILED DESCRIPTION

[0060] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0061] The following describes an imaging optical system 100 according to an embodiment of the present invention with reference to the drawings.

[0062] According to the imaging optical system 100 of the embodiment of the present invention, Figure 1 As shown, it includes: a flat lens 1 and a reflection component 5.

[0063] The two opposite sides of the flat lens 1 are the image source side and the viewing side, that is, the light source of the image P1 is located on the image source side. The image P1 passes through the flat lens 1 and can form a floating real image P2 on the viewing side. The floating real image P2 is a real image suspended in the air. Figure 2-Figure 4 As shown, the flat lens 1 is an optical structure that utilizes two periodically distributed, orthogonal optical waveguide arrays 10, causing light to undergo a total internal reflection (TIR) ​​in each of the two layers. Because the two layers of optical waveguide arrays 10 are orthogonal rectangular structures, the angle of incidence during the first TIR and the angle of exit during the second TIR are identical. After passing through the flat lens 1, light within the divergent angle of the light source converges toward the viewing side, resulting in a floating real image P2 with a 1:1 ratio to the image P1.

[0064] It's understandable that the light divergence angle of the floating real image P2 can be considered the field of view angle of the floating real image P2 from the viewing side. Given the symmetry of image P1 and floating real image P2 relative to flat lens 1, the angle of light from image P1's light source incident on flat lens 1 is roughly equal to the light divergence angle of the floating real image P2. Therefore, the larger the area of ​​flat lens 1, the greater the field of view angle of the floating real image P2.

[0065] In practical applications, the area of ​​the flat lens 1 cannot be excessively large. Therefore, the image produced by a conventional flat lens 1 exhibits a narrow field of view. For example, the horizontal field of view of some flat lenses 1 is approximately ±30 degrees. When the human eye's position deviates from this field of view, the resulting real image cannot be seen. This is particularly true in public areas, where only a small area of ​​the audience facing the flat lens 1 can see a clear real image. Viewers slightly off-center will find it difficult to see a clear real image.

[0066] To solve this problem, the imaging optical system 100 in the present application is provided with a reflection component 5 , and the reflection surface 5 s of the reflection component 5 is used in conjunction with the flat lens 1 to form an image.

[0067] Reference Figure 1 The reflective assembly 5 has at least one pair of reflective surfaces 5s, with the two reflective surfaces 5s in the same pair located on the image source side and the viewing side, respectively. In the drawings of this application, the two reflective surfaces 5s in the same pair located on the image source side and the viewing side are labeled 5P.

[0068] The reflective surface 5s is a plane and is disposed toward the center normal L1 of the flat lens 1. The angle α between the reflective surface 5s and the flat lens 1 is less than or equal to 90 degrees. It should be noted that the flat lens 1 has a center normal L1, which is a reference line introduced in this application to describe the structure of the imaging optical system 100. The center normal L1 passes through the center of the flat lens 1 and is parallel to the thickness direction of the flat lens 1. The center of the flat lens 1 refers to the centroid of the flat lens 1.

[0069] A reflective surface 5s is provided on the image source side, allowing light from the image P1 light source directed toward this reflective surface 5s to be reflected toward the flat lens 1. A corresponding reflective surface 5s is provided on the viewing side, allowing light emitted from the flat lens 1 to be reflected by this reflective surface 5s toward the floating real image P2. This arrangement of the same pair of reflective surfaces 5s allows light from the image P1 light source, which would otherwise be unable to reach the flat lens 1, to be directed toward the flat lens 1 via the reflective surfaces 5s. This increases the angle of the light from the image P1 light source toward the flat lens 1, thereby increasing the divergence angle of the light from the floating real image P2. Therefore, the provision of the reflective component 5 can increase the field of view of the imaging optical system 100 compared to a solution without the reflective component 5.

[0070] Here, the reflective surface 5s is a plane, which can prevent deformation of the floating real image P2. The included angle α between the two reflective surfaces 5s in the same pair and the flat lens 1 is equal, and the intersection lines of the two reflective surfaces 5s in the same pair and the flat lens 1 are parallel to each other. This makes the light reflection path of the two reflective surfaces 5s in the same pair symmetrical relative to the flat lens 1, thereby further preventing deformation of the floating real image P2. It should be noted that when the reflective surface 5s is in contact with the flat lens 1, the intersection line between the reflective surface 5s and the flat lens 1 is the contact line between the reflective surface 5s and the flat lens 1. When the reflective surface 5s is not in contact with the flat lens 1, the intersection line between the reflective surface 5s and the flat lens 1 refers to the intersection line of the reflective surface 5s with the flat lens 1 in the extension direction.

[0071] The included angle α between the reflective surface 5s and the flat lens 1 is less than or equal to 90 degrees, which helps to control the size of the imaging optical system 100 within a reasonable range. It is also understandable that if the included angle α between the reflective surface 5s and the flat lens 1 is greater than 90 degrees, the reflective surface 5s is in an open state compared to the solution in which the reflective surface 5s is perpendicular to the flat lens 1. The open reflective surface 5s will reflect some light away from the flat lens 1, and this light will become ineffective light. Therefore, to improve the effective utilization rate of light, the solution of this application sets the included angle α between the reflective surface 5s and the flat lens 1 to be less than or equal to 90 degrees.

[0072] It can also be seen here that by controlling the included angle α between the reflective surface 5s and the flat lens 1, the purpose of adjusting the imaging field angle can be achieved.

[0073] According to the imaging optical system 100 of an embodiment of the present invention, by providing reflective surfaces 5s on the image source side and the viewing side of the flat lens 1, respectively, and by providing the reflective surfaces 5s in pairs, the reflective surfaces 5s can be utilized to increase the field of view. In some embodiments, the reflective surfaces 5s can even expand the field of view to 180 degrees. This allows for greater viewing angles when viewers view the floating real image P2 on the viewing side. This increased field of view accommodates a greater number of viewers, enabling the imaging optical system 100 to be used in public areas for display purposes, thus transcending the limitations of a single flat lens 1. Furthermore, by utilizing the reflective surfaces 5s to reflect light, the utilization rate of light at the edge of the light source can be increased, allowing more light to be directed toward the floating real image P2. This helps enhance the brightness and clarity of the floating real image P2, thereby improving imaging quality.

[0074] In order to deepen the understanding of the technical solution of this application, the following Figure 2-Figure 9 The basic structure and imaging principle of the flat lens 1 are described.

[0075] See Figure 2-Figure 4The flat lens 1 includes two optical waveguide arrays 10. Each optical waveguide array 10 is composed of multiple rows of sub-waveguides 101 arranged in a single column. Each sub-waveguide 101 has a rectangular cross-section. The cross-section of a sub-waveguide 101 refers to a cross-section perpendicular to its length.

[0076] See Figure 3-Figure 5 The two groups of optical waveguide arrays 10 include: a first optical waveguide array 11 and a second optical waveguide array 12. The sub-waveguides 101 of the first optical waveguide array 11 extend along the X direction and form multiple rows along the Y direction. The sub-waveguides 101 of the second optical waveguide array 12 extend along the Y direction and form multiple rows along the X direction. The first optical waveguide array 11 and the second optical waveguide array 12 are arranged along the Z direction, and the X direction, Y direction, and Z direction are perpendicular to each other. Here, the extension direction of the sub-waveguide 101 is the length direction of the sub-waveguide 101. The length direction of a single sub-waveguide 101 in the first optical waveguide array 11 is the X direction. The multiple sub-waveguides 101 in the first optical waveguide array 11 are arranged closely together and superimposed along the Y direction, and the width direction of a single sub-waveguide 101 is the Y direction. The length direction of a single sub-waveguide 101 in the second optical waveguide array 12 is the Y direction. The multiple sub-waveguides 101 in the second optical waveguide array 12 are arranged closely together and superimposed along the X direction, and the width direction of a single sub-waveguide 101 is the X direction. The two sets of optical waveguide arrays 10 are respectively flat-plate-shaped. The arrangement direction from the first optical waveguide array 11 to the second optical waveguide array 12 is the Z direction, which is also the thickness direction of the flat lens 1. It should be noted that in the first optical waveguide array 11 and the second optical waveguide array 12, the first optical waveguide array 11 can be closer to the image source side, or the second optical waveguide array 12 can be closer to the image source side, without limitation. The length directions of the two layers of sub-waveguides 101 are perpendicular to each other, so the two layers of optical waveguide array 10 are said to be orthogonal to each other.

[0077] Optionally, each sub-waveguide 101 is provided with a reflective film on both sides in the width direction for total reflection of light. For example, a sub-waveguide 101 of the first optical waveguide array 11 is provided with a reflective film on both sides in the Y direction. Since the first optical waveguide array 11 includes multiple sub-waveguides 101, the first optical waveguide array 11 will have multiple reflective films arranged along the Y direction. A sub-waveguide 101 of the second optical waveguide array 12 is provided with a reflective film on both sides in the X direction. Since the second optical waveguide array 12 includes multiple sub-waveguides 101, the second optical waveguide array 12 will have multiple reflective films arranged along the X direction.

[0078] In some embodiments, such as Figure 2 and Figure 4As shown, the flat lens 1 may further include a protective cover 30, which is used to support and protect the optical waveguide array 10. The protective cover 30 may be provided on only one side of the flat lens 1, or on both sides of the flat lens 1. Specifically, the protective cover 30 is a transparent cover, and optionally, the protective cover 30 is a glass plate.

[0079] Figure 2-Figure 4 The figure is a schematic diagram of the structure of a flat lens 1 in one embodiment. The flat lens 1 includes a pair of protective covers 30, namely a first cover 31 and a second cover 32. The flat lens 1 also includes two optical waveguide arrays 10, namely a first optical waveguide array 11 and a second optical waveguide array 12, located between the two protective covers 30. The X direction is the extension direction of the sub-waveguides 101 in the first optical waveguide array 11, the Y direction is the extension direction of the sub-waveguides 101 in the second optical waveguide array 12, and the Z direction is the thickness direction of the flat lens 1. Of course, in some solutions, the protective covers 30 can be eliminated, and other methods can be used to protect the optical waveguide arrays 10.

[0080] Alternatively, as Figure 5 As shown, the outer contour of the formed optical waveguide array 10 is rectangular, and the angle θ between the extension direction of each sub-waveguide 101 and at least two sides of the outer contour of the optical waveguide array 10 is further optionally satisfied: 30°≤θ≤60°, preferably θ=45°. At this angle, the floating real image P2 is clear and the afterimage is not obvious.

[0081] Here, the core imaging components of the flat lens 1 are the first optical waveguide array 11 and the second optical waveguide array 12. The first optical waveguide array 11 and the second optical waveguide array 12 include mutually orthogonal single-row and multi-row sub-waveguides 101. The flat lens 1 is flat as a whole. Figure 6 As shown, it can achieve point-to-point aberration-free imaging of image P1.

[0082] The specific imaging principle is as follows: Here, the two optical waveguide arrays 10 are split. Figure 7 and Figure 8 As shown, taking the first optical waveguide array 11 as an example, in a single-layer optical waveguide array 10, a single point light from the image source side passes through the single-sided optical waveguide array 10, is split and mirror-modulated by each row of sub-waveguides 101, and then reconverges on a straight line P1' parallel to the X-direction, forming a point-to-line one-dimensional imaging effect. Figure 7 As shown in FIG, the incident angle of a single point light on the image source side passing through a certain sub-waveguide 101 is δ, and the exit angle after reflection from the sub-waveguide 101 is δ'. The incident angle δ is equal to the exit angle δ'.

[0083] like Figure 9As shown, to achieve a point-intersection in both directions (X and Y), two optical waveguide arrays 10 are used in conjunction, with the sub-waveguides 101 arranged perpendicularly on the two layers. This allows for point-to-point modulation of the target light source image P1. Therefore, light rays from any direction passing through this mutually orthogonal double-layer optical waveguide array 10 can be reconverged at symmetrical locations on the optical waveguide array 10 to form a floating real image P2. The imaging distance m2 of the floating real image P2 is the same as the distance m1 to the original image, achieving equidistant imaging. Furthermore, the floating real image P2 is located in mid-air, eliminating the need for a projection screen or other support, and can be directly displayed in mid-air.

[0084] Therefore, this flat lens 1 can make a two-dimensional or three-dimensional light source directly form a real image in the air and realize a true holographic image. While achieving a large field of view, large aperture, high resolution, no distortion, and no dispersion, it also realizes naked-eye three-dimensional stereoscopic display characteristics.

[0085] In the drawings of the present application, the flat lens 1 is rectangular. However, in other embodiments of the present application, the shape of the flat lens 1 can also be adjusted as needed, for example, it can be circular, trapezoidal, etc., which is not limited here.

[0086] In some embodiments, as Figure 1 As shown, the two reflecting surfaces 5s in the same pair are symmetrical with respect to the flat lens 1, and thus the two reflecting surfaces 5s in the same pair have the same shape and area, which can fully utilize the area of ​​the reflecting surfaces 5s and reduce light loss.

[0087] Specifically, the two reflecting surfaces 5s in the same pair respectively form intersection lines with the flat lens 1. The two intersection lines are not only parallel, but also the plane formed by the two intersection lines is perpendicular to the flat lens 1. This can avoid image stitching misalignment.

[0088] In some embodiments, one side of the reflective surface 5s is bonded to the flat lens 1. It will be appreciated that when a gap exists between the reflective surface 5s and the flat lens 1, the portion of the floating real image P2 corresponding to the line connecting the human eye and the gap will be missing when viewed from within a certain expanded viewing angle. In other words, the floating real image P2 cannot be seen within this viewing angle. However, when one side of the reflective surface 5s is bonded to the flat lens 1, the gap is filled, effectively expanding the viewing angle.

[0089] Specifically, one side of each of the reflecting surfaces 5s is attached to the flat lens 1. This fills the gaps at all of the reflecting surfaces 5s, thereby further effectively expanding the viewing angle range.

[0090] In the solution of the present application, the reflective surfaces 5s of the reflective assembly 5 can be one pair, two pairs, or three pairs, or even more pairs according to the needs of the flat lens 1 and the display 200, which is not limited here.

[0091] When the reflective assembly 5 includes multiple pairs of reflective surfaces 5s, the multiple pairs of reflective surfaces 5s are arranged in a direction surrounding the central normal L1. That is, the multiple reflective surfaces 5s on the image source side surround the central normal L1, and the multiple reflective surfaces 5s on the viewing side also surround the central normal L1. This arrangement leaves the area directly opposite the center of the flat-panel lens 1 free for placement of the light source image P1. For example, the display screen 210 of the monitor 200 can be aligned directly with the center of the flat-panel lens 1.

[0092] In some embodiments, such as Figure 10-13 As shown, there are two pairs of reflective surfaces 5s located on opposite sides of the center normal L1. Each pair of reflective surfaces 5s on opposite sides of the center normal L1 forms an equal angle α with the flat lens 1, and the intersection lines of each reflective surface 5s with the flat lens 1 are parallel to each other. This helps broaden the field of view of the imaging optical system 100 in the direction of the two pairs of reflective surfaces 5s. Furthermore, the two pairs of reflective surfaces 5s complement each other, allowing light to be continuously reflected between the two pairs of reflective surfaces 5s, thus expanding the field of view of the imaging optical system 100 in this direction to nearly 180 degrees.

[0093] Such an imaging optical system 100, when two pairs of reflecting surfaces 5s are placed on both horizontal sides of the flat lens 1, can expand the horizontal field angle of the imaging optical system 100, and can accommodate more viewers to watch at the same time when used in a public area.

[0094] In some embodiments, such as Figures 14-19 As shown, the imaging optical system 100 includes a pair of reflective surfaces 5s, which are located on one side of the flat lens 1. In this way, the viewing angle of the viewer on the other side of the flat lens 1 can be expanded by utilizing the reflection of the reflective surfaces 5s.

[0095] In other embodiments, Figure 20 As shown, the imaging optical system 100 includes three pairs of reflection surfaces 5 s , which are located on three sides of the flat lens 1 .

[0096] Even the imaging optical system 100 includes four pairs of reflecting surfaces 5s, which are located on four sides of the flat lens 1. Even when the flat lens 1 is a polygon (having at least five sides), the imaging optical system 100 may include more pairs of reflecting surfaces 5s.

[0097] In the solution of this application, if Figure 10-11 As shown, the reflective assembly 5 includes a reflector 50, and a reflective surface 5s is provided on the surface of the reflector 50. The shape of the reflector 50 can be set as needed. In some solutions, the reflector 50 is a plane mirror 51, such as Figure 11 As shown, in some solutions, the reflector 50 is of other shapes, such as Figure 22 The middle reflector 50 is a prism 52 , and two prism faces of the reflector 50 constitute a reflective surface 5s.

[0098] exist Figure 10-Figure 21 In the illustrated embodiment, the reflective assembly 5 includes at least two reflectors 50, each of which is a plane mirror 51. The surface of each reflector 50 facing the center normal L1 constitutes a reflective surface 5s. Using plane mirrors 51 to construct the reflective surface 5s not only simplifies the structure, but also substantially aligns the shape of the plane mirrors 51 with the reflective surface 5s. Furthermore, the plane mirrors 51 can be relatively thin, which helps reduce weight.

[0099] In summary, the imaging optical system 100 according to the embodiment of the present invention, by providing a pair of reflective surfaces 5s, has the most direct effect of expanding the field of view of the floating real image P2 in at least one direction, and in some solutions it can even be expanded to 180°.

[0100] The setting of the reflecting surface 5s can make full use of light, and reflect the light that originally cannot reach the flat lens 1 and illuminate it onto the flat lens 1, so that it can be focused by the flat lens 1 to form an image, thereby improving the utilization rate of light and increasing the brightness of the floating real image P2.

[0101] The present invention's solution utilizing the reflective surface 5s makes it very simple to set up the reflective surface 5s. Furthermore, by optimizing the size, shape, and angle α between the reflective surface 5s and the flat lens 1, the volume of the imaging optical system 100 can be substantially reduced. The reflective surface 5s is also relatively inexpensive to set up and can be manufactured on a large scale.

[0102] The structure of a display device 1000 according to an embodiment of the present invention will be described below with reference to the accompanying drawings.

[0103] The display device 1000 according to an embodiment of the present invention is as follows: Figure 22 As shown, it comprises: an imaging optical system 100 according to the above embodiment of the present invention and a display 200 (such as Figure 22 As shown in FIG, the imaging optical system 100 can adopt the structure of the imaging optical system 100 described in the above embodiment, and some repeated details are omitted here. The display 200 is located on the image source side, with the display screen 210 of the display 200 facing the flat lens 1. Thus, when an image is formed on the display screen 210, the light emitted by the display screen 210 passes through the flat lens 1, and a floating real image P2 with a 1:1 ratio to the image P1 is presented on the viewing side.

[0104] It should be noted that this application Figure 10-Figure 21 The structure diagram and principle diagram of the display device 1000 in multiple embodiments are shown. In the principle diagram of some embodiments, since the light overlaps with the image P1 and the floating real image P2 of the display screen 210, only part of the image P1 and the corresponding part of the floating real image P2 are intercepted in the diagram. Figure 11 and Figure 13shown.

[0105] By providing a pair of reflective surfaces 5s on either side of the flat lens 1, the reflective surfaces 5s can increase the field of view. In some implementations, the reflective surfaces 5s can even extend the field of view to 180 degrees. This increased field of view accommodates more viewers when viewing the floating real image P2 from the viewing side. This allows the display device 1000 to be used in public areas for exhibition purposes, thus overcoming the limitations of the display device 1000. Furthermore, by reflecting light from the reflective surfaces 5s, the utilization rate of light from the light source's edges can be increased, allowing more light to be directed toward the floating real image P2, thereby improving image quality.

[0106] In some specific embodiments, the display screen 210 is a candy bar screen, and the angle λ between the display screen 210 and the flat lens 1 is acute. It will be appreciated that when light enters along the thickness of the flat lens 1, it tends to pass directly through the flat lens 1, significantly reducing the amount of light that undergoes total internal reflection. Forming an angle λ between the display screen 210 and the flat lens 1 facilitates the formation of a certain angle between the majority of light emitted by the display screen 210 and the reflective portions (e.g., reflective portions formed by reflective films) on either side of the width of the sub-waveguide 101 when the majority of light is directed toward the flat lens 1. This allows the majority of light to be reflected toward the viewing side, thereby improving light utilization.

[0107] Specifically, the four sides of the display screen 210 are a near side 211 , a far side 212 and two inclined sides 213 . The near side 211 and the far side 212 are opposite sides of the display screen 210 . The near side 211 is located on the side of the display screen 210 adjacent to the flat lens 1 .

[0108] In this case, reflective surfaces 5s can be provided on one, two, or three sides of the display screen 210. Specifically, on the image source side, reflective surfaces 5s can be provided on each of the two inclined edges 213 of the display screen 210, or on the side corresponding to the distal edge 212 of the display screen 210, or on both sides of the two inclined edges 213 and on the side corresponding to the distal edge 212 of the display screen 210. Utilizing these reflective surfaces 5s can increase the viewing angle of the display screen 210 in one or two directions.

[0109] Just as in the embodiment of the imaging optical system 100 described above, the reflective surface 5s can be arranged in a variety of forms, similarly, the reflective surface 5s in the display device 1000 can also be arranged in a variety of forms.

[0110] For example, in some optional embodiments, Figure 10-13As shown, the reflective surface 5s corresponding to the inclined edge 213 is a first view-enhancing reflective surface 5s-1. When the display device 1000 includes a first view-enhancing reflective surface 5s-1, two first view-enhancing reflective surfaces 5s-1 are typically provided, with the two first view-enhancing reflective surfaces 5s-1 being provided corresponding to the inclined edge 213 of the flat lens 1. In this way, the two first view-enhancing reflective surfaces 5s-1 and the flat lens 1 do not interfere with each other, and instead cooperate with each other to increase the field of view angle in the direction of the two first view-enhancing reflective surfaces 5s-1.

[0111] Specifically, the projection formed by the display screen 210 along a direction parallel to the flat lens 1 lies entirely within the first vision-enhancing reflective surface 5s-1. It should be noted that the mathematical term "projection" is used herein to more clearly describe the shape of the reflective surface 5s. Here, "the projection formed by the display screen 210 along a direction parallel to the flat lens 1" refers to the pattern formed on the first vision-enhancing reflective surface 5s-1 when a projection line parallel to the flat lens 1 is projected onto the first vision-enhancing reflective surface 5s-1 through the display screen 210. All projection patterns mentioned below are also obtained using this definition.

[0112] By positioning the projection of the display screen 210 parallel to the flat-panel lens 1 completely within the first vision-enhancing reflective surface 5s-1, when the light source divergence angle of the display screen 210 approaches 180 degrees, the majority of light within a 180-degree range in the direction of the two first vision-enhancing reflective surfaces 5s-1 is directed toward the flat-panel lens 1 and the two first vision-enhancing reflective surfaces 5s-1. This allows the light of the viewing-side floating real image P2 to diverge within a 180-degree range, resulting in a roughly 180-degree field of view in the direction of the two first vision-enhancing reflective surfaces 5s-1. This reduces light waste and improves the brightness of the floating real image P2.

[0113] Specifically, the first vision-enhancing reflective surface 5s-1 is triangular or trapezoidal, and the projection of the display screen 210 along a direction parallel to the flat lens 1 is flush with one side of the first vision-enhancing reflective surface 5s-1. Optionally, when the first vision-enhancing reflective surface 5s-1 is trapezoidal, a right-angled trapezoid may be used.

[0114] It is understandable that the divergence angle of the light source of the display screen 210 is unlikely to exceed 180 degrees, so that substantially no light is incident on the portion of the first vision-enhancing reflective surface 5s-1 beyond the display screen 210.

[0115] Moreover, even if the divergence angle of the display screen 210 exceeds 180 degrees, when the light exceeding 180 degrees is reflected by the reflective surface 5s, part of it is reflected in the direction away from the flat lens 1, and part of it will be blocked by the back of the display screen 210. This part of the light is actually invalid, and the part of the first vision-enhancing reflective surface 5s-1 that exceeds the display screen 210 is still wasted.

[0116] Therefore, the projection of the display screen 210 in a direction parallel to the flat lens 1 is aligned with one side of the first vision-enhancing reflective surface 5s-1, thereby reducing the useless area of ​​the first vision-enhancing reflective surface 5s-1.

[0117] In some optional embodiments, such as Figures 14-19 As shown, the reflective surface 5s corresponding to the distal edge 212 is the second view-enhancing reflective surface 5s-2. When the display device 1000 includes a second view-enhancing reflective surface 5s-2, only one second view-enhancing reflective surface 5s-2 is typically provided, and is positioned corresponding to the distal edge 212 of the flat-panel lens 1. Because the near edge 211 of the display screen 210 is relatively close to the flat-panel lens 1, the space available for the reflective surface 5s is limited. Therefore, the second view-enhancing reflective surface 5s-2 is only suitably positioned corresponding to the distal edge 212 of the display screen 210.

[0118] When a second vision-enhancing reflective surface 5s-2 is provided, it is rectangular. Because the second vision-enhancing reflective surface 5s-2 is substantially opposite the display screen 210, the entire surface of the second vision-enhancing reflective surface 5s-2 effectively reflects light when there are no other obstructions and the light source divergence angle of the display screen 210 is close to 180 degrees. In this case, the rectangular shape of the second vision-enhancing reflective surface 5s-2 reduces light leakage. Furthermore, the rectangular shape of the second vision-enhancing reflective surface 5s-2 is not only easy to manufacture but also very convenient to install and secure.

[0119] In some optional embodiments, such as Figure 20-21 As shown, the two inclined edges 213 of the display screen 210 are respectively provided with a first vision-enhancing reflective surface 5s-1, and the far edge 212 of the display screen 210 is correspondingly provided with a second vision-enhancing reflective surface 5s-2. The first vision-enhancing reflective surface 5s-1 is triangular, and the projection of the display screen 210 along a direction parallel to the flat lens 1 is flush with one side of the first vision-enhancing reflective surface 5s-1. The projection of the second vision-enhancing reflective surface 5s-2 along a direction parallel to the flat lens 1 is flush with the other side of the first vision-enhancing reflective surface 5s-1. In this way, the two first vision-enhancing reflective surfaces 5s-1 and the one second vision-enhancing reflective surface 5s-2 can surround three sides of the inclined display screen 210, thereby reflecting as much light as possible to the flat lens 1. This not only increases the field of view in two directions, but also maximizes the utilization of light and improves the brightness of the floating real image P2.

[0120] The following describes possible configurations of the reflective surface 5s when the display screen 210 is a straight screen, in conjunction with the accompanying drawings of specific embodiments.

[0121] Example 1:

[0122] Figure 10-11Shown is a simplified structural diagram of a display device 1000 in Example 1 and a schematic diagram of the principle of expanding the horizontal field of view angle. The display device 1000 is a first display device 1000A.

[0123] The first display device 1000A includes a display 200 , four reflective mirrors 50 , and a flat lens 1 .

[0124] The display 200 is a flat-panel display with a light source divergence angle close to 180 degrees. In order to improve the imaging quality of the floating real image P2, the angle λ between the display screen 210 of the display 200 and the flat-panel lens 1 is selected to be 45°. The four reflectors 50 are divided into two pairs, and the two reflectors 50 in the same pair are respectively located on the image source side and the viewing side. The surface of each reflector 50 facing the center normal L1 of the flat-panel lens 1 forms its reflective surface 5s. In Example 1, the four reflective surfaces 5s are all first vision-enhancing reflective surfaces 5s-1. On the image source side, the two first vision-enhancing reflective surfaces 5s-1 are located on the left and right sides of the flat-panel lens 1, and on the viewing side, the two first vision-enhancing reflective surfaces 5s-1 are located on the left and right sides of the flat-panel lens 1.

[0125] The two reflectors 50 in the same pair are equal in size and symmetrical about the flat lens 1. The two reflectors 50 on the image source side are symmetrical about the central normal L1, and the two reflectors 50 on the viewing side are symmetrical about the central normal L1 to avoid image misalignment. Assuming the flat lens 1 is positioned horizontally, both sets of reflectors 50 are positioned vertically.

[0126] As mentioned above, the shape of the first vision-enhancing reflective surface 5s-1 can be a right-angled trapezoid or a triangle. The first vision-enhancing reflective surface 5s-1 in the first display device 1000A is triangular in shape, which can minimize the volume of consumables and the entire device.

[0127] The first side of each pair of two triangular reflectors 50 fits tightly against the flat lens 1. The second side of the reflector 50 on the image source side coincides with the object plane (i.e., the plane where the image P1 or display screen 210 is located), and the second side of the reflector 50 on the viewing side coincides with the image plane (i.e., the plane where the floating real image P2 is located). The height of the reflector 50 on the image source side is equal to the height of the display screen 210, and the height of the reflector 50 on the viewing side is equal to the height of the floating real image P2. The third side of the reflector 50 on the image source side is formed by a line connecting the edge of the flat lens 1 to a position at the same height as the display screen 210, and the third side of the reflector 50 on the viewing side is formed by a line connecting the edge of the flat lens 1 to a position at the same height as the floating real image P2.

[0128] In Example 1, the principle of expanding the field of view is as follows Figure 11As shown. On the image source side, the first vision-enhancing reflective surfaces 5s-1 located on the left and right sides of the flat lens 1 reflect the marginal viewing angle light that was originally unable to enter the flat lens 1 and reuse it to allow it to enter the flat lens 1. After exiting, it is reflected by the first vision-enhancing reflective surfaces 5s-1 located on the left and right sides of the flat lens 1 on the viewing side, and finally appears on the image plane. The two sets of reflectors 50 are placed vertically so that the angle α between the first vision-enhancing reflective surfaces 5s-1 and the flat lens 1 is 90 degrees, η is the viewing angle without the reflectors 50, β is the increased field of view angle range on the left side, and the increased field of view angle range on the right side is similar. The actual increased field of view angle is approximately equal to 180°-η. The increase in the horizontal field of view angle is affected by the divergence angle of the light source of the display 200, but is not affected by parameters such as the size of the flat lens 1, the display 200, and the distance between the display 200 and the flat lens 1.

[0129] In the solution of Example 1, through the above configuration, the horizontal viewing angle of the floating real image P2 is equal to the horizontal viewing angle of the display 200. When the light source divergence angle of the display screen 210 is 180 degrees, the horizontal viewing angle of the floating real image P2 is also approximately 180 degrees.

[0130] Example 2:

[0131] Figure 12-13 Shown is a simplified structural diagram of a display device 1000 in Example 2 and a schematic diagram of the principle of expanding the horizontal field of view. The display device 1000 is a second display device 1000B.

[0132] The second display device 1000B includes: a display 200, four reflective mirrors 50 and a flat lens 1. Figure 12 As shown, the structural layout of the second display device 1000B in Example 2 is substantially the same as that of the first display device 1000A in Example 1, and the same parts are not repeated here.

[0133] α is the angle between the first vision-enhancing reflective surface 5s-1 and the flat lens 1. Unlike Example 1, in Example 2, the angle α between the first vision-enhancing reflective surface 5s-1 and the flat lens 1 is an acute angle, that is, greater than 0 degrees and less than 90 degrees. η is the viewing angle without the reflector 50, β is the increased field of view angle range on the left side, and the increased field of view angle range on the right side is similar. The actual increased field of view angle is approximately equal to 180°-η. The increase in the horizontal field of view angle is affected by the divergence angle of the light source of the display 200. In the solution of Example 2, through the above-mentioned setting, the horizontal field of view angle of the floating real image P2 is equal to the horizontal field of view angle of the display 200. When the divergence angle of the light source of the display screen 210 is 180 degrees, the horizontal field of view angle of the floating real image P2 is also approximately 180 degrees.

[0134] To summarize Examples 1 and 2, both the first display device 1000A and the second display device 1000B can increase the horizontal viewing angle to 180 degrees, achieving substantially the same field of view increase effect, and neither device causes distortion of the floating real image P2. Both display devices 1000 limit the size of the display 200. In the second display device 1000B, the inwardly tilted reflector 50 imposes a greater size restriction on the display 200. The size of the display 200 should not exceed the vertical angular distance between the left and right reflectors 50.

[0135] In addition, in Example 2, all reflectors 50 are tilted, which can easily lead to errors in the tilt angles of the reflectors 50. Furthermore, if the tilt angles of two reflectors 50 in a pair are unequal, image misalignment is likely to occur. Relatively speaking, when the reflectors 50 are placed vertically, the angle α is easier to control. Therefore, Example 1 is easier to implement and can better ensure image quality.

[0136] Example 3:

[0137] Figure 14-15 Shown is a simplified structural diagram of a display device 1000 in Example 3 and a schematic diagram of the principle of expanding the vertical viewing angle. The display device 1000 is a third display device 1000C.

[0138] The third display device 1000C includes a display 200 , two reflecting mirrors 50 , and a flat lens 1 .

[0139] The display 200 is a flat panel display with a light source divergence angle close to 180 degrees. In order to improve the imaging quality of the floating real image P2, the included angle λ between the display screen 210 of the display 200 and the flat panel lens 1 is selected to be 45°.

[0140] Assuming that the near side 211 of the display screen 210 is adjacent to the front side of the flat lens 1 , the two reflective mirrors 50 are disposed on the rear side of the flat lens 1 , and are located on the image source side and the viewing side, respectively.

[0141] The reflector 50 is rectangular in shape, with one side of it close to the flat lens 1. The two reflectors 50 are placed vertically and symmetrically about the flat lens 1. The front surfaces of the two reflectors 50 constitute the second vision-enhancing reflective surface 5s-2. The height of the two reflectors 50 is the same as the height of the display 200 and the floating real image P2.

[0142] The principle of expanding the vertical field of view is as follows: Figure 15As shown in the figure, α is the angle between the reflector 50 and the flat lens 1, which is 90 degrees. η is the viewing angle without the reflector 50. β is the actual increased field of view of the third display device 1000C. The vertical field of view of the floating real image P2 is determined by the height of the reflector 50 and the size of the flat lens 1. Since the angle λ between the display 200 and the flat lens 1 is preferably 45 degrees, the sum of η and β is always less than 135 degrees. Only when the size of the flat lens 1 is infinitely large does the sum of η and β approach 135 degrees.

[0143] Example 4:

[0144] Figure 16-Figure 19 Shown is a simplified structural diagram of a display device 1000 in Example 4 and a schematic diagram of the principle of expanding the vertical viewing angle. The display device 1000 is a fourth display device 1000D.

[0145] The fourth display device 1000D includes a display 200 , two reflecting mirrors 50 , and a flat lens 1 .

[0146] The angle between the reflector 50 and the flat lens 1 is α, and one side of the reflector 50 is close to the flat lens 1. The height of the reflector 50 is slightly higher than the height of the display 200 and the floating real image P2. The principle of expanding the field of view in the vertical direction is as follows: Figure 17 The fourth display device 1000D in Example 4 has a substantially similar structure to the third display device 1000C in Example 3, except that in Example 4 the included angle α between the reflector 50 and the flat lens 1 is less than 90 degrees and is an acute angle.

[0147] like Figure 17 As shown, light from the edge of the display 200 is reflected by the second vision-enhancing reflective surface 5s-2 on the image source side before re-entering the flat lens 1. The outgoing light is then reflected by the second vision-enhancing reflective surface 5s-2 on the viewing side, thereby increasing the field of view. Here, η is the viewing angle without the reflector 50, β is the actual increased field of view of the fourth display device 1000D, and γ is the angle between the reflector 50 and the display 200 or the floating real image P2.

[0148] Figure 17-Figure 19 It shows that when other parameters remain unchanged and the included angle α between the reflector 50 and the flat lens 1 gradually decreases, the included angle between the reflector 50 and the floating real image P2 gradually increases. At this time, the increased range β of the field angle will have a certain change.

[0149] It can be seen that only when γ≥90°, the light from the edge viewing angle is reflected by the second vision-enhancing reflective surface 5s-2 on the image source side, and then enters the flat lens 1 close to the display screen 210. The outgoing light is then reflected by the second vision-enhancing reflective surface 5s-2 on the viewing side, thereby expanding the viewing angle range. When γ=90°, the principle is as follows Figure 18 As shown, when γ>90°, the principle is as follows Figure 19 When γ=90°, the sum of η and β is infinitely close to 180 degrees, and when γ>90°, the entire device requires a larger size of the flat lens 1, but the field of view in the vertical direction can no longer be increased.

[0150] In summary, when γ=90° and the included angle α between the reflector 50 and the flat lens 1 is 45°, the volume of the imaging device is the smallest and the vertical field angle is close to 180°.

[0151] Example 5:

[0152] Figure 20-21 Shown is a simplified structural diagram of a display device 1000 in Example 5 and a schematic diagram of the principle of expanding the vertical viewing angle. The display device 1000 is a fifth display device 1000E.

[0153] The fifth display device 1000E includes: a display 200 , four reflectors 50 for increasing the horizontal viewing angle, two reflectors 50 for increasing the vertical viewing angle, and a flat lens 1 .

[0154] The solution of Example 5 is equivalent to combining the solution of Example 1 with the solution of Example 4.

[0155] The display 200 is a flat panel display with a light source divergence angle close to 180 degrees. In order to improve the imaging quality of the floating real image P2, the angle λ between the display 200 and the flat panel lens 1 is selected to be 45 degrees.

[0156] Assume that the near edge 211 of the display screen 210 is adjacent to the front side of the flat lens 1, there are three reflectors 20 located on the image source side, and are respectively located on the left, right and rear sides of the flat lens 1, and there are three reflectors 20 located on the viewing side, and are respectively located on the left, right and rear sides of the flat lens 1.

[0157] The left and right reflectors 50 are equal in size and symmetrical about the flat lens 1. The two reflectors 50 on the same side are symmetrical about the center normal L1 of the flat lens 1. The left and right reflectors 50 are both vertically positioned and have a triangular shape, minimizing the size of consumables and the entire device.

[0158] The first side of the reflectors 50 on the left and right sides is tightly fitted with the flat lens 1, the second side coincides with the object plane or the image plane, the height of the reflectors 50 is equal to the height of the display screen 210 and the floating real image P2, and the third side is formed by the line connecting the edge of the flat lens 1 to the position at the same height as the display screen 210 and the floating real image P2.

[0159] The reflectors 50 added to the upper and lower surfaces of the rear side of the flat lens 1 are rectangular in shape. The angle α between the reflector 50 and the flat lens 1 is 45 degrees. One side of the reflector 50 is in close contact with the flat lens 1. The height of the reflector 50 is substantially the same as that of the display screen 210 and the floating real image P2. The side view of the structure is shown in FIG. Figure 21 shown.

[0160] The fifth display device 1000E can fully reduce the size of the device by optimizing the size of the reflector 50 and the angle α between the reflector 50 and the flat lens 1, and can observe the floating real image P2 within a viewing angle range of 180 degrees in the horizontal and vertical directions.

[0161] In summary, when display device 1000 is used in public settings, the horizontal field of view of display device 1000 can be increased by adding a reflector 50 to each left and right side of display 200 and floating real image P2. The reflectors 50 in the same pair are symmetrical about flat lens 1, and the reflectors 50 on the same side are symmetrical about the center normal L1 of flat lens 1. The reflectors 50 can be tilted inward or placed vertically, with vertical placement being preferred to maximize utilization of flat lens 1 and allow for a larger display 200. The reflector surface of the reflector 50 can be a right-angled trapezoid or a triangle, with a triangle being preferred to minimize consumables and the overall device size. The first side of each pair of two triangular reflectors 50 is tightly fitted with the flat lens 1, and the second side coincides with the object plane or the image plane (depending on whether the reflector 50 is on the image source side or the viewing side). The height of the reflector 50 is equal to the height of the display 200 and the floating real image P2. The third side is formed by the line connecting the edge of the flat lens 1 to the position at the same height as the display 200 and the floating real image P2.

[0162] The display device 1000 increases the field of view in the vertical direction by adding a reflector 50 to the upper and lower surfaces of the side of the flat lens 1 away from the observer. The reflector 50 is rectangular in shape, with one side of the reflector in close contact with the flat lens 1. It can be placed vertically or tilted inward. It is preferably tilted inward, which increases the field of view and reduces the device size.

[0163] In the display device 1000 with increased horizontal viewing angle, the horizontal viewing angle of the floating real image P2 is only related to the horizontal viewing angle of the display 200, and is not related to the sizes of the flat lens 1 and the display 200, or the distance between the display 200 and the flat lens 1.

[0164] In the display device 1000 with increased vertical viewing angle, the vertical viewing angle of the floating real image P2 is related to the included angle between the reflector 50 and the flat lens 1 , the height of the reflector 50 , and the size of the flat lens 1 .

[0165] In the description of the present invention, it should be understood that the terms "center", "length", "width", "height", "thickness", "up", "down", "left", "right", "vertical", "horizontal", "top", "bottom", etc., indicating the orientation or positional relationship, are 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, be constructed and operate in a specific orientation. Therefore, they cannot be understood as limiting the present invention. In addition, features defined as "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0166] Throughout this specification, reference to terms such as "embodiment" or "example" indicates that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0167] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the claims and their equivalents.

Claims

1. An imaging optical system, characterized in that: include: a flat plate lens having a central normal that passes through the center of the flat plate lens and is parallel to the thickness direction of the flat plate lens; opposite sides of the flat plate lens are an image source side and a viewing side, respectively; the light source of the image is located on the image source side, and the image passes through the flat plate lens to form a floating real image on the viewing side that is suspended in the air; A reflective component having at least one pair of reflective surfaces, wherein the two reflective surfaces in the same pair are respectively located on the image source side and the viewing side, wherein the reflective surfaces are both plane and arranged toward the central normal, and the angle between the reflective surface and the flat lens is less than or equal to 90 degrees, wherein: The included angles between the two reflecting surfaces in the same pair and the flat lens are equal, and the intersection lines between the two reflecting surfaces in the same pair and the flat lens are parallel to each other; The flat lens includes a pair of protective cover plates, namely a first cover plate and a second cover plate; The flat lens further includes two groups of optical waveguide arrays located between the two protective cover plates, each group of optical waveguide arrays consisting of a single column and multiple rows of sub-waveguides; and they are respectively a first optical waveguide array and a second optical waveguide array; The outer contour of the optical waveguide array is rectangular, and the included angle between the extension direction of each sub-waveguide and at least two sides of the outer contour of the optical waveguide array is θ, and θ satisfies: 30°≤θ≤60°.

2. The imaging optical system according to claim 1, wherein: One side of the reflecting surface is attached to the flat lens.

3. The imaging optical system according to any one of claims 1 to 2, characterized in that: The two reflecting surfaces in the same pair are symmetrically arranged relative to the flat lens.

4. A display device, characterized in that: include: The imaging optical system according to any one of claims 1 to 3; A display is located on the image source side, with a display screen of the display facing the flat lens, and the display screen is used to present the image.

5. The display device according to claim 4, wherein: The display screen includes a near side and a far side opposite to each other, the near side being a side of the display screen adjacent to the flat lens; On the image source side, the reflective surface includes a second vision-enhancing reflective surface corresponding to the far edge, wherein one side of the second vision-enhancing reflective surface is close to the flat lens and the other side is close to the far edge.

6. The display device according to claim 5, wherein: The display screen is a straight screen, and the angle between the display screen and the flat-panel lens is an acute angle.

7. The display device according to claim 4, wherein: The reflective assembly includes at least two reflectors, each of which is a plane mirror, and a surface of each reflector facing the center normal constitutes the reflective surface.

8. The display device according to claim 4, wherein: The reflective component includes a prism, and two facets of the prism constitute the two reflective surfaces in the same pair.

9. The display device according to claim 7, wherein: The height of the reflector relative to the flat lens is equal to the height of the display screen relative to the flat lens.

10. The display device according to claim 5, wherein The second vision-enhancing reflective surface is rectangular.

Images