Prism and display device

Abstract

The utility model provides a prism and a display device, the prism comprises a first surface, a second surface, a third surface and a fourth surface, the first surface, the second surface and the third surface are connected pairwise, one end of the fourth surface is connected with one end of the second surface, and the other end of the fourth surface extends in a direction far away from the third surface; wherein the image source light enters the first surface from the third surface, is totally reflected to the second surface, is finally totally reflected to the first surface and is transmitted to the eyes of a human body; the real light is transmitted into human eyes through the fourth surface, the second surface and the first surface. The prism is provided with the four surfaces, the first surface and the second surface are used for totally reflecting the light emitted by the image source and the light of the real world, and the third surface and the fourth surface are used for transmitting the light of the image source and the light of the real world, so that the light angle of the light of the image source and the light of the real world entering the prism is corrected. The image imaging effect of the prism is enhanced, so that the display device is smaller and lighter.

Description

Technical Field

[0001] The utility model relates to the field of optical systems, and particularly to a prism and a display device. Background Art

[0002] At present, traditional display devices are set in the form of off-axis reflection and standard prism structures, but this form cannot solve the contradiction between the requirements of the optical system for the field of view and the exit pupil distance and miniaturization and light weight. The traditional off-axis reflection system can achieve a relatively large field of view but makes the display device too bulky, resulting in a poor user experience. While the standard prism structure can achieve miniaturization and light weight, the field of view and the exit pupil are relatively small, and the imaging effect of the picture is poor. In order to meet the market demand, the display system needs to develop in the direction of smaller and lighter. Content of the Utility Model

[0003] An embodiment of the utility model provides a prism and a display device to improve the imaging effect of the picture of the prism and make the display device smaller and lighter.

[0004] The utility model provides a prism, which comprises:

[0005] A first surface, a second surface, a third surface and a fourth surface, wherein the first surface, the second surface and the third surface are connected to each other in pairs, one end of the fourth surface is connected to one end of the second surface, and the other end extends in a direction away from the third surface;

[0006] Wherein, image source light rays are incident from the third surface to the first surface, totally reflected to the second surface, and finally totally reflected to the first surface and transmitted to the human eye; real light rays are transmitted into the human eye through the fourth surface, the second surface and the first surface.

[0007] In the prism provided by the utility model, the prism comprises a first prism and a second prism, the first prism comprises the first surface, the second surface and the third surface, the second prism comprises the second surface and the fourth surface, and the second surface of the first prism and the second surface of the second prism are adhesively connected.

[0008] In the prism provided by the utility model, the first surface, the second surface, the third surface and the fourth surface are all free-form surfaces.

[0009] In the prism provided by the utility model, the surface type of the prism is a bi-conic free-form surface.

[0010] In the prism provided by the utility model, the radius of curvature of the first surface is between -94.29 and -104.29, and the conic coefficient is between 20.05 and 30.05.

[0011] In the prism provided by the present utility model, the radius of curvature of the second surface is between -37.30 and -47.30, and the conic coefficient is between -11.286 and -21.286.

[0012] In the prism provided by the present utility model, the radius of curvature of the third surface is between 1.39 and -9.39, and the conic coefficient is between -101.1 and -111.1.

[0013] In the prism provided by the present utility model, the radius of curvature of the fourth surface is between -46.79 and -56.79, and the conic coefficient is between -72.61 and -82.61.

[0014] In the prism provided by the present utility model, the first surface and / or the second surface is coated with a reflective film layer.

[0015] In the prism provided by the present utility model, the first surface and / or the second surface is coated with an antireflection film.

[0016] In the prism provided by the present utility model, the thickness of the prism is within 20 mm.

[0017] In the prism provided by the present utility model, the material of the prism is PMMA.

[0018] The present utility model also provides a display device, which includes:

[0019] A prism, which is the prism described in any one of the above.

[0020] The present utility model provides a prism and a display device. The prism includes a first surface, a second surface, a third surface and a fourth surface. The first surface, the second surface and the third surface are connected to each other in pairs. One end of the fourth surface is connected to one end of the second surface, and the other end extends away from the third surface. Among them, the image source light enters the first surface from the third surface, is totally reflected to the second surface, and finally is totally reflected to the first surface and transmitted to the human eye; the real light is transmitted into the human eye through the fourth surface, the second surface and the first surface. In this application, by providing the prism with four surfaces, the first surface and the second surface are used to totally reflect the light emitted by the image source and the light in the real world, and the third surface and the fourth surface are used to transmit the image source light and the real light, so as to correct the light angles of the image source light and the real light entering the prism. Therefore, the imaging effect of the prism is enhanced, and the product size of the display device provided with the prism is reduced, and the display device is smaller and lighter. Description of the Drawings

[0021] To more clearly illustrate the technical solutions of the embodiments of the present utility model, the following will briefly introduce the accompanying drawings required for the description of the embodiments. Obviously, the accompanying drawings in the following description are some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can also be obtained based on these drawings.

[0022] Figure 1 It is the structural diagram of the prism in the embodiment of the present utility model;

[0023] Figure 2 It is the solid structural diagram of the prism in the embodiment of the present utility model;

[0024] Each reference numeral in the figure is as follows:

[0025] 100, prism; 110, first surface; 120, second surface; 130, third surface; 140, fourth surface; 150, first prism; 160, second prism. Specific embodiments

[0026] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. Now, in combination with the accompanying drawings, the preferred embodiments of the present utility model will be described in detail.

[0027] Referring to Figure 1 and Figure 2 As shown, it shows an embodiment of the prism 100 of the present utility model and a display device. The prism 100 includes a first surface 110, a second surface 120, a third surface 130, and a fourth surface 140. The first surface 110, the second surface 120, and the third surface 130 are connected to each other in pairs. One end of the fourth surface 140 is connected to one end of the second surface 120, and the other end extends in a direction away from the third surface 130; wherein, the image source light enters the first surface 110 from the third surface 130, is totally reflected to the second surface 120, and finally is totally reflected to the first surface 110 and transmitted to the human eye; the real light is transmitted into the human eye through the fourth surface 140, the second surface 120, and the first surface 110.

[0028] Specifically, the prism 100 is used in a display device in the field of AR and VR to image the human eye, and can be equipped in a wearable device, such as glasses, helmets, etc.; the prism 100 has four surfaces, including a first surface 110, a second surface 120, a third surface 130, and a fourth surface 140, wherein the first surface 110, the second surface 120, and the third surface 130 are connected to each other in pairs; the third surface 130 is arranged in a direction close to an image source, and the image source includes a display screen, a mobile phone, a computer, and other display devices, and the first surface 110 is arranged close to the human eye. direction, the second surface 120 is set in a direction close to the real light of the real world, so when the image source emits the image source light, the image source light passes through the third surface 130 and is incident on the first surface 110 via the third surface 130, the first surface 110 totally reflects the image source light and totally reflects it onto the second surface 120, the image source light is totally reflected onto the first surface 110 via the second surface 120, and is transmitted to the human eye via the first surface 110, so that the user can see the image of the image source.

[0029] At the same time, one end of the fourth surface 140 is fixedly connected to one end of the second surface 120, and the other end of the fourth surface 140 is extended in a direction away from the third surface 130, that is, one end of the fourth surface 140 is fixedly connected to one end where the second surface 120 and the third surface 130 are connected, and the extension direction of the fourth surface 140 is consistent with the extension direction of the first surface 110, the second surface 120 is located between the first surface 110 and the fourth surface 140, the image source is located above the fourth surface 140, and the real world is located on the side of the fourth surface 140 away from the second surface 120. When real light from the real world enters the fourth surface 140, it is transmitted into the interior of the prism 100 through the fourth surface 140, and is transmitted into the human eye through the second surface 120 and the first surface 110 in turn, so that the image of the real world is seen by the user.

[0030] The image of the image source and the image of the real world are superimposed so that the user can see the image of the image source and the image of the real world at the same time.

[0031] In this application, by providing the prism 100 with four surfaces, the first surface 110 and the second surface 120 are used to totally reflect the light rays emitted by the image source and the light rays of the real world, and the third surface 130 and the fourth surface 140 are used to transmit the light rays of the image source and the real light rays, thereby correcting the light angles of the light rays of the image source and the real light rays entering the prism 100. Therefore, the imaging effect of the picture of the prism 100 is enhanced, and the display device provided with the prism 100 is smaller and lighter.

[0032] Specifically, the first surface 110 and the second surface 120 are total reflection surfaces, so that the light rays of the image source and the real light rays can form total reflection inside the prism 100. Compared with the off-axis reflection system that penetrates, it is possible to make the display device with a light ray system smaller and lighter.

[0033] In an embodiment, referring to Figure 1 As shown, the prism 100 includes a first prism 150 and a second prism 160. The first prism 150 includes the first surface 110, the second surface 120 and the third surface 130. The second prism 160 includes the second surface 120 and the fourth surface 140. The second surface 120 of the first prism 150 and the second surface 120 of the second prism 160 are adhesively connected. Specifically, the prism 100 is formed by gluing the first prism 150 and the second prism 160. The first prism 150 includes the first surface 110, the second surface 120 and the third surface 130, and the first surface 110, the second surface 120 and the third surface 130 are connected to each other pairwise; the second prism 160 includes the second surface 120 and the fourth surface 140. One end of the fourth surface 140 is connected to one end of the second surface 120, and the second surface 120 of the second prism 160 is adhesively connected and fixed to the second surface 120 of the first prism 150, so that the first prism 150 and the second prism 160 are glued to form the prism 100. In this application, the prism 100 is formed by gluing the first prism 150 and the second prism 160 together, which is convenient for structural assembly design; at the same time, positive and negative aberrations are generated between the first prism 150 and the second prism 160, so that the second prism 160 can correct the aberration generated by the first prism 150, so that the prism 100 will not generate large distortion and form a better imaging effect of the picture. Specifically, the aberration is within 5%.

[0034] In a specific embodiment, referring to Figure 1As shown, the first surface 110, the second surface 120, the third surface 130, and the fourth surface 140 are all free-form surfaces. Specifically, the four surfaces of the prism 100 all adopt free-form surface profiles, so that the surface profile degrees of freedom of the first surface 110, the second surface 120, the third surface 130, and the fourth surface 140 are high. The free-form surface can adjust the surface profile curvature of different light positions to optimize the aberration, thus facilitating the surface profile optimization of the prism 100 to obtain a better picture imaging effect.

[0035] In one embodiment, as shown in Figure 1 As shown, the surface profile of the prism 100 is a bi-conic free-form surface. Specifically, the first surface 110, the second surface 120, and the third surface 130 are connected to each other in pairs. One end of the fourth surface 140 is connected to one end of the second surface 120, and the other end of the fourth surface 140 extends away from the third surface 130. Therefore, the cross-section formed by enclosing the four surfaces of the prism 100 is a bi-conic structure. By setting the surface profile of the prism 100 as a bi-conic free-form surface, the conic coefficients and basic radii of the bi-conic free-form surface in the X and Y directions can be different. This surface profile has many parameters available for optimization and high surface profile editability. Therefore, the prism 100 has more parameters available for optimization, making the surface profile degrees of freedom of the four surfaces of the prism 100 higher.

[0036] This application uses two free-form surface prisms 100 glued together, combining the off-axis system and the prism 100 structure, effectively reducing the system structure size, and at the same time achieving better imaging quality, solving the contradiction between the field of view angle, exit pupil distance, and miniaturization and lightweight.

[0037] In a specific embodiment, the radius of curvature of the first surface 110 is between -94.29 and -104.29, and the conic coefficient is between 20.05 and 30.05. Specifically, setting the radius of curvature of the first surface 110 of the prism 100 between -94.29 and -104.29 and the conic coefficient between 20.05 and 30.05 can better improve the picture imaging effect generated by the prism 100. In particular, in this embodiment, the radius of curvature of the first surface is set to -99.29, and the conic coefficient is set to 25.05.

[0038] In one embodiment, the radius of curvature of the second surface 120 is between -37.30 and -47.30, and the conic coefficient is between -11.286 and -21.286. Specifically, the radius of curvature of the second surface 120 of the prism 100 is between -37.30 and -47.30, and the conic coefficient is between -11.286 and -21.286, so as to better improve the imaging effect of the image generated by the prism 100. In particular, in this embodiment, the radius of curvature of the second surface is set to -42.30, and the conic coefficient is set to -16.286.

[0039] In a specific embodiment, the radius of curvature of the third surface 130 is between 1.39 and -9.39, and the conic coefficient is between -101.1 and -111.1. Specifically, the radius of curvature of the third surface 130 of the prism 100 is between 1.39 and -9.39, and the conic coefficient is between -101.1 and -111.1, so as to better improve the imaging effect of the image generated by the prism 100. In particular, in this embodiment, the radius of curvature of the third surface is -4.39, and the conic coefficient is -106.1.

[0040] In one embodiment, the radius of curvature of the fourth surface 140 is between -46.79 and -56.79, and the conic coefficient is between -72.61 and -82.61. Specifically, the radius of curvature of the fourth surface 140 of the prism 100 is between -46.79 and -56.79, and the conic coefficient is between -72.61 and -82.61, so as to better improve the imaging effect of the image generated by the prism 100. In particular, in this embodiment, the radius of curvature of the fourth surface is -51.79, and the conic coefficient is -77.61.

[0041] In one embodiment, the first surface 110 and / or the second surface 120 is coated with a reflective film layer (not shown in the figure). Specifically, the outer side of the first surface 110 and / or the second surface 120 is coated with a reflective film layer. The outer side refers to the surface of the first surface 110 and / or the second surface 120 in contact with air. That is, the outer side of the first surface 110 refers to the side of the first surface 110 close to the human eye, and the outer side of the second surface 120 refers to the side of the second surface 120 close to the fourth surface 140, so as to adjust the brightness of the image source and the image of the real world entering the human eye.

[0042] When the second surface 120 is coated with a total reflection film, the image source light rays enter the first surface 110 from the third surface 130, are reflected to the second surface 120, and finally are reflected by the second surface 120 to the first surface 110 and then transmitted to the human eye. At the same time, the real light rays in the real world are blocked, so that the images in the real world do not enter the human eye. At this time, the user can only see the images of the image source, and this optical system can be used as a VR system. When neither the second surface 120 nor the first surface 110 is coated, the images in the real world and the images of the image source can both be imaged on the human eye, and this optical system can be used as an AR system.

[0043] Therefore, the prism 100 in this embodiment can realize the switching between AR and VR systems by means of coating.

[0044] In a specific embodiment, the first surface 110 and / or the second surface 120 is coated with an anti-reflection film (not shown in the figure). Specifically, the anti-reflection film is used to enhance the transmission ability of the first surface 110 and / or the second surface 120. The anti-reflection film is disposed on the outer side of the first surface 110 and / or the second surface 120. That is, the outer side of the first surface 110 refers to the side of the first surface 110 close to the human eye, and the outer side of the second surface 120 refers to the side of the second surface 120 close to the fourth surface 140, so as to improve the transmittance of the first surface 110 and / or the second surface 120 to the image source light rays and the real light rays.

[0045] In one embodiment, referring to Figure 2 As shown, the thickness of the prism 100 is within 20 mm. Specifically, the prism 100 includes four surfaces. The first surface 110, the second surface 120, and the third surface 130 are connected to each other in pairs to enclose the first internal space of the prism 100, and the image source light rays are totally reflected in the first internal space to the human eye. One end of the second surface 120 is connected to the fourth surface 140, and a second internal space of the prism 100 is formed between the second surface 120 and the fourth surface 140. The real light rays are respectively transmitted through the second internal space and the first internal space to the human eye. The thickness of the prism 100 refers to the distance between the vertical plane where the end of the prism 100 closest to the human eye is located and the vertical plane where the end of the prism 100 closest to the emission of the real light rays is located. The thickness of the prism 100 is set within 20 mm, so as to ensure that the image source light rays and the real light rays are reflected and transmitted inside the prism 100 to the human eye, producing a better picture imaging effect, and ensuring the small size and light weight of the prism 100.

[0046] In a specific embodiment, the material of the prism 100 is PMMA. Specifically, the PMMA material is commonly known as plexiglass, which has excellent light transmission performance, can transmit more than 92% of sunlight, and 73.5% of ultraviolet light; and has relatively high mechanical strength, certain heat and cold resistance, corrosion resistance, good insulation performance, stable dimensions, and is easy to mold. Therefore, the material of the prism 100 in this embodiment uses the PMMA material, and the prism 100 is manufactured by an injection molding process, making the processing of the prism 100 easy and the cost low.

[0047] This application also provides a display device (not shown in the figure), the display device includes a prism 100, and the prism 100 is the prism 100 described in any of the above items. Since the prism 100 is described in detail in the above embodiments, it will not be repeated here.

[0048] Since the display device uses the prism 100 in this embodiment, the imaging effect of the picture of the prism 100 is better, the prism 100 is lighter in weight and has a simple structure, making the display device smaller and lighter.

[0049] Specifically, the working wavelength band of the prism 100 is 587nm - 656nm, the exit pupil diameter is 6mm, the exit pupil distance is 18mm, and the field of view angle is 30°. Specifically, when a normal human eye observes external things without turning the neck, generally only a field of view angle of 20 to 30° is required; of course, if it is too small, the neck needs to be turned to make up for the lack of the field of view, which will cause damage to the user's neck over time. Generally, if only digital characters are displayed, the required field of view angle can be between 4° - 15°. Therefore, the AR display system does not have to pursue too large a field of view angle. The AR display system uses a half field of view angle of 20° (H) × 15° (V), which is suitable for a 0.47in OLED-XLTM display screen; in this embodiment, the working wavelength band of the prism 100 is set at 587nm - 656nm, the exit pupil diameter is 6mm, the exit pupil distance is 18mm, and the field of view angle is 30°, so as to form a better imaging effect of the picture; at the same time, the exit pupil diameter of the human eye is generally 3mm, and the movement range of the eye within the field of view is generally 5mm, but for users wearing glasses, the exit pupil distance can even reach 20mm. In order to facilitate the use of the display device by glasses wearers, the prism 100 uses an exit pupil distance of 18mm.

[0050] The above is only the specific implementation manner of the present utility model, but the protection scope of the present utility model is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present utility model can easily think of various equivalent modifications or substitutions, and these modifications or substitutions should all be covered within the protection scope of the present utility model. Therefore, the protection scope of the present utility model should be subject to the protection scope of the claims.

Claims

1. A prism, characterized in that: include: a first surface, a second surface, a third surface and a fourth surface, wherein the first surface, the second surface and the third surface are connected in pairs, one end of the fourth surface is connected to one end of the second surface, and the other end extends in a direction away from the third surface; The image source light is incident from the third surface to the first surface, and is totally reflected to the second surface, and finally totally reflected to the first surface and transmitted to the human eye; The actual light is transmitted into the human eye through the fourth surface, the second surface and the first surface.

2. The prism according to claim 1, characterized in that The prism includes a first prism and a second prism, the first prism includes the first surface, the second surface and the third surface, the second prism includes the second surface and the fourth surface, and the second surface of the first prism and the second surface of the second prism are glued together.

3. The prism according to any one of claims 1 to 2, characterized in that: The first surface, the second surface, the third surface and the fourth surface are all free-form surfaces.

4. The prism according to claim 3, characterized in that The surface shape of the prism is a double-conical free-form surface.

5. The prism according to claim 4, characterized in that The curvature radius of the first surface is between -94.29 and -104.29, and the cone coefficient is between 20.05 and 30.

05.

6. The prism according to claim 4, characterized in that The curvature radius of the second surface is between -37.30 and -47.30, and the cone coefficient is between -11.286 and -21.

286.

7. The prism according to claim 4, characterized in that The radius of curvature of the third surface is between 1.39 and -9.39, and the cone coefficient is between -101.1 and -111.

1.

8. The prism according to claim 4, characterized in that The radius of curvature of the fourth surface is between -46.79 and -56.79, and the cone coefficient is between -72.61 and -82.

61.

9. The prism according to claim 1, characterized in that The first surface and / or the second surface is coated with a reflective film layer.

10. The prism according to claim 1, characterized in that The first surface and / or the second surface is coated with an anti-reflection film.

11. The prism according to claim 1, characterized in that The thickness of the prism is within 20 mm.

12. The prism according to claim 1, characterized in that The material of the prism is PMMA.

13. A display device, characterized in that: include: A prism, wherein the prism is the prism described in any one of claims 1 to 12.

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