Optical display system and VR device

Abstract

The invention discloses an optical display system and VR (virtual reality) equipment. The optical display system comprises an entrance pupil, a first lens, a second lens, a third lens, a fourth lens and a display which are sequentially arranged along an optical axis direction, one surface, close to the entrance pupil, of the first lens and one surface away from the entrance pupil are spherical surfaces; one surface, far away from the first lens, of the second lens, one surface, far away from the second lens, of the third lens and one surface, near the third lens, of the fourth lens are all even aspheric surfaces; the surface, close to the second lens, of the third lens is a quadric surface, and the surface, away from the third lens, of the fourth lens is a binary surface with positive focal power. Compared with the prior art, while the field angle of the optical display system is increased and distortion is reduced, the complexity of the optical display system can be effectively reduced, so that the size and the weight of the optical display system are effectively reduced, and the wearing experience of VR equipment is improved.

Description

Technical Field

[0001] The present invention relates to the field of optical technology, and in particular to an optical display system and VR equipment. Background Art

[0002] With the development of optical technology, users have higher and higher requirements for VR devices. In the design process of existing VR devices, it is necessary to improve the field of view while maintaining high resolution. However, increasing the field of view will bring complex off-axis aberrations to the optical display system and increase the distortion of the optical display system. In the existing technology, the imaging quality problem is usually solved by increasing the number of lenses, but increasing the number of lenses will increase the complexity of the optical display system, increase the volume and weight of the optical display system, and thus affect the wearing experience of the VR device.

[0003] In view of this, it is necessary to provide an optical display system and a VR device to solve the above problems. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides an optical display system and a VR device, which can effectively reduce the complexity of the optical display system while increasing the field of view angle of the optical display system and reducing distortion, thereby effectively reducing the volume and weight of the optical display system and improving the wearing experience of the VR device.

[0005] To achieve the above-mentioned purpose, the first aspect of the present invention provides an optical display system, which includes an entrance pupil, a first lens, a second lens, a third lens, a fourth lens and a display arranged in sequence along the optical axis; a side of the first lens close to the entrance pupil and a side away from the entrance pupil are both spherical surfaces; a side of the second lens close to the first lens, a side of the second lens away from the first lens, a side of the third lens away from the second lens and a side of the fourth lens close to the third lens are all even-order aspherical surfaces; a side of the third lens close to the second lens is a quadratic surface, and a side of the fourth lens away from the third lens is a binary surface with positive optical power.

[0006] In a preferred embodiment, the first lens is a convex lens made of glass, the second lens is a convex lens made of plastic, and the third lens and the fourth lens are both concave lenses made of plastic.

[0007] In a preferred embodiment, the highest order of the even-order aspheric surface is 10.

[0008] In a preferred embodiment, the Conic coefficient of the quadratic surface ranges from -1 to 0.

[0009] In a preferred embodiment, the diffraction order of the binary surface is first order.

[0010] In a preferred embodiment, the binary surface is a six-order polynomial binary surface.

[0011] In a preferred embodiment, the refractive index of the first lens is in the range of 1.80 to 1.90.

[0012] In a preferred embodiment, the aperture of the second lens is larger than the aperture of the first lens.

[0013] In a preferred embodiment, the half diagonal length of the display ranges from 2.2 inches to 2.4 inches.

[0014] A second aspect of the present invention provides a VR device, which includes the optical display system in any one of the aforementioned embodiments.

[0015] The beneficial effect of the present invention is that it can effectively reduce the complexity of the optical display system while increasing the field of view of the optical display system and reducing distortion, thereby effectively reducing the volume and weight of the optical display system and improving the wearing experience of the VR device. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of the structure of an optical display system provided by an embodiment of the present invention;

[0017] Figure 2 A spot diagram of an optical display system provided by an embodiment of the present invention;

[0018] Figure 3 An MTF diagram of an optical display system provided by an embodiment of the present invention;

[0019] Figure 4 A distortion curve diagram of the optical display system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0020] In the present invention, the terms "disposed", "provided with" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements or components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0021] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "plurality" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0022] In addition, some of the above terms may be used to express other meanings in addition to indicating orientation or positional relationship. For example, the term "on" may also be used to express a certain dependency or connection relationship in some cases. For those skilled in the art, the specific meanings of these terms in the present invention can be understood according to specific circumstances.

[0023] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0024] Specifically, the following is the content provided by the first aspect of the present invention:

[0025] Please refer to Figure 1 In this embodiment, the optical display system includes an entrance pupil 1, a first lens 2, a second lens 3, a third lens 4, a fourth lens 5 and a display 6 which are arranged in sequence along the optical axis.

[0026] The first lens 2 and the second lens 3 are both convex lenses, the third lens 4 and the fourth lens 5 are both concave lenses, and the display 6 includes but is not limited to a liquid crystal display, an organic light emitting semiconductor display or a liquid crystal on silicon display.

[0027] The center point of the entrance pupil 1, the center point of the first lens 2, the center point of the second lens 3, the center point of the third lens 4, the center point of the fourth lens 5 and the center point of the display 6 are all on the same straight line. The side of the first lens 2 close to the entrance pupil 1 and the side away from the entrance pupil 1 are both spherical surfaces; the side of the second lens 3 close to the first lens 2, the side of the second lens 3 away from the first lens 2, the side of the third lens 4 away from the second lens 3 and the side of the fourth lens 5 close to the third lens 4 are all even-order aspherical surfaces; the side of the third lens 4 close to the second lens 3 is a quadratic surface, and the side of the fourth lens 5 away from the third lens 4 is a binary surface with positive optical power.

[0028] Specifically, in this embodiment, the total length of the optical display system is 70 mm, the field of view angle is 120°, the incident light is in the visible light band, the maximum order of the even-order aspheric surface is 10, the Con ic coefficient of the quadratic surface ranges from -1 to 0, the binary surface is a polynomial binary surface, and the half-diagonal length of the display 6 ranges from 2.2 inches to 2.4 inches.

[0029] It is easy to understand that the surface of the fourth lens 5 away from the third lens 4 is a binary surface with positive optical power, which plays the role of a negative lens in the optical display system. When the optical power meets the requirements, the chromatic aberration of the optical display system can be effectively corrected, and the monochromatic aberration of the system can be reduced to a certain extent.

[0030] In a preferred embodiment, the diffraction order of the binary surface is 1st order, and the binary surface is a six-order polynomial binary surface. Specifically, the binary surface adopts a six-order polynomial binary surface, and its order coefficients are A1=-9.614E+005, A2=1.7130E+006, A3=-1.961E+006, A4=-2.055E+005, A5=2.787E+006, and A6=-1.798E+006.

[0031] It can be understood that by adopting a four-piece lens group structure, by setting even-order aspheric surfaces, quadratic surfaces and binary surfaces, the complexity of the optical display system can be effectively reduced while increasing the field of view angle of the optical display system and reducing distortion, thereby effectively reducing the volume and weight of the optical display system and improving the wearing experience of VR equipment.

[0032] Furthermore, in one embodiment, the first lens 2 is a convex lens made of glass, the second lens 3 is a convex lens made of plastic, and the third lens 4 and the fourth lens 5 are both concave lenses made of plastic.

[0033] It can be understood that the first lens 2 is made of glass, which can effectively improve the light transmittance of the optical display system. The second lens 3, the third lens 4 and the fourth lens 5 are all made of plastic, which can effectively reduce the structural weight of the optical display system while meeting the imaging quality.

[0034] Furthermore, in one embodiment, the refractive index of the first lens 2 is in a range of 1.80 to 1.90, and the aperture of the second lens 3 is larger than that of the first lens 2 .

[0035] It is understandable that the first lens 2 uses a higher refractive index to meet the light propagation of a large deflection angle, which is more conducive to the design of a larger field of view. The aperture of the second lens 3 is larger than the aperture of the first lens 2, and can significantly refract the incident light.

[0036] To better explain the optical display system, some parameter design values ​​of each lens in the optical display system are now described by way of example. Specifically, please refer to Table 1, wherein the larger the serial number value corresponding to the surface type is, the closer the surface type is to the display 6.

[0037]

[0038] Table 1

[0039] Further, based on the aforementioned optical display system and lens design parameters, Figure 2 It can be seen that the minimum and maximum RMS radius of the diffuse spot of the optical system are both within one pixel, which can meet the design requirements. Figure 3It can be seen that when the system transfer function is 20l p / mm, the minimum value of the full field of view is 0.26. For the visual imaging system, the image quality has met the imaging requirements. Figure 4 It can be seen that the distortion value within the full field of view does not exceed 10.2%, which also meets the requirement of low distortion in a large field of view.

[0040] In summary, the optical display system provided in the present application can effectively reduce the complexity of the optical display system while increasing the field of view angle of the optical display system and reducing distortion, thereby effectively reducing the volume and weight of the optical display system and improving the wearing experience of the VR device.

[0041] The following is the content of the second aspect of the present invention:

[0042] The present invention provides a VR device, which includes the aforementioned optical display system. The VR device can effectively reduce the complexity of the optical display system while increasing the field of view angle of the optical display system and reducing distortion, thereby effectively reducing the volume and weight of the optical display system and improving the wearing experience of the VR device.

[0043] The above is only a specific implementation method of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. An optical display system, characterized in that: It includes an entrance pupil, a first lens, a second lens, a third lens, a fourth lens and a display arranged in sequence along the optical axis; a surface of the first lens close to the entrance pupil and a surface away from the entrance pupil are both spherical surfaces; a surface of the second lens close to the first lens, a surface of the second lens away from the first lens, a surface of the third lens away from the second lens and a surface of the fourth lens close to the third lens are all even-order aspherical surfaces; a surface of the third lens close to the second lens is a quadratic surface, and a surface of the fourth lens away from the third lens is a binary surface with positive optical power.

2. The optical display system according to claim 1, characterized in that: The first lens is a convex lens made of glass, the second lens is a convex lens made of plastic, and the third lens and the fourth lens are both concave lenses made of plastic.

3. The optical display system according to claim 1, characterized in that: The highest order of the even-order aspheric surface is 10.

4. The optical display system according to claim 1, characterized in that: The Conic coefficient of the quadratic surface ranges from -1 to 0.

5. The optical display system according to claim 1, characterized in that: The diffraction order of the binary surface is first order.

6. The optical display system according to claim 1, characterized in that: The binary surface is a six-order polynomial binary surface.

7. The optical display system according to claim 1, characterized in that: The refractive index of the first lens is in the range of 1.80 to 1.

90.

8. The optical display system according to claim 1, characterized in that: The aperture of the second lens is larger than that of the first lens.

9. The optical display system according to claim 1, characterized in that: The display has a half diagonal length ranging from 2.2 inches to 2.4 inches.

10. A VR device, characterized in that: An optical display system comprising any one of claims 1 to 9.

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