Head-mounted display optical system and VR device

Abstract

The utility model discloses a head-mounted display optical system and VR equipment. The head-mounted display optical system comprises a receiving end, a first lens, a second lens, a third lens, a fourth lens and a display, the first lens, the second lens, the third lens and the fourth lens are sequentially arranged between the receiving end and the display along the direction from the receiving end to the display; the first lens and the fourth lens are meniscus lenses which are convex towards the display and have positive focal power, the second lens is a biconvex lens with positive focal power, the third lens is a biconcave lens with negative focal power, and one surface, close to the display, of the fourth lens is an even-order aspheric surface. Compared with the prior art, through the arrangement of the lens group, the compact structure of the optical system is ensured, more light rays can be introduced, a large field angle can be obtained, aberration can be effectively corrected, distortion can be reduced, the imaging quality can be improved, the weight and the size of the VR can be reduced, and the use experience of a user can be improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to optical technology field especially relates to a head-mounted display optical system and VR equipment. BACKGROUND

[0002] With the development of optical technology, the user's requirement to VR equipment is also higher and higher. In the design process of the existing VR equipment, it is required to improve the field of view while maintaining high resolution, but increasing the field of view will bring aberration to the head-mounted display optical system and increase the distortion of the head-mounted display optical system. In the prior art, the imaging quality problem is usually solved by increasing the lens amount, but increasing the lens amount will increase the complexity of the head-mounted display optical system, increase the volume and weight of the head-mounted display optical system, and thus affect the wearing experience of the VR equipment.

[0003] Therefore, it is necessary to provide a head-mounted display optical system and VR equipment to solve the above problems. SUMMARY

[0004] In view of the deficiencies in the prior art, the utility model provides a head-mounted display optical system and VR equipment, which can reduce the weight and volume of the optical system while improving the imaging quality of the optical system, so as to improve the user's experience.

[0005] To achieve the above purpose, the first aspect of the utility model provides a head-mounted display optical system, which comprises a receiving end, a first lens, a second lens, a third lens, a fourth lens and a display. The first lens, the second lens, the third lens and the fourth lens are sequentially arranged between the receiving end and the display along the direction from the receiving end to the display. The first lens and the fourth lens are both meniscus lenses convex to the display and have positive focal power, the second lens is a biconvex lens with positive focal power, the third lens is a biconcave lens with negative focal power, and the fourth lens has an even aspheric surface on the side close to the display.

[0006] In a preferred embodiment, the effective focal lengths of the first lens, the second lens, the third lens and the fourth lens are F1, F2, F3 and F4 respectively, and F1, F2 and F4 are positive, and F3 is negative.

[0007] In a preferred embodiment, the effective focal length of the head-mounted display optical system is F, and it satisfies: 1.47≤F1 / F≤1.83, 1.53≤F2 / F≤1.75, -1.71≤F3 / F≤-1.383, 0.23≤F4 / F≤0.27.

[0008] In a preferred embodiment, the refractive indexes of the first lens, the second lens, the third lens and the fourth lens at D line are N1, N2, N3 and N4 respectively, and satisfy: 1.78 ≤ N1 ≤ 1.82, 1.78 ≤ N2 ≤ 1.86, 1.75 ≤ N3 ≤ 1.85, 1.62 ≤ N4 ≤ 1.89.

[0009] In a preferred embodiment, the Abbe numbers of the first lens, the second lens, the third lens and the fourth lens at D line are V1, V2, V3 and V4 respectively, and satisfy: 35 ≤ V1 ≤ 70, 35 ≤ V2 ≤ 65, 20 ≤ V3 ≤ 28, 18 ≤ V4 ≤ 50.

[0010] In a preferred embodiment, the half field of view angle of the head-mounted display optical system is HFOV, and satisfies: 59° ≤ HFOV ≤ 60°.

[0011] In a preferred embodiment, the curvature radius of the first lens near the receiving end surface is R1, and the curvature radius of the first lens away from the receiving end surface is R2; the curvature radius of the second lens near the receiving end surface is R3, and the curvature radius of the second lens away from the receiving end surface is R4; the curvature radius of the third lens near the receiving end surface is R5, and the curvature radius of the third lens away from the receiving end surface is R6; the curvature radius of the fourth lens near the receiving end surface is R7, and satisfy: -62.5mm ≤ R1 ≤ -51.7mm, -32.5mm ≤ R2 ≤ -29mm, 78mm ≤ R3 ≤ 95mm, -143.32mm ≤ R4 ≤ -115.8mm, -118.4mm ≤ R5 ≤ -88mm, 95.27mm ≤ R6 ≤ 135.4mm, -55mm ≤ R7 ≤ -37.6mm.

[0012] In a preferred embodiment, the even-order aspheric surface of the fourth lens is a 10th-order aspheric surface.

[0013] In a preferred embodiment, the first lens, the second lens, the third lens and the fourth lens are all glass lenses.

[0014] The second aspect of the utility model provides a kind of VR equipment, it includes the head-mounted display optical system in any one of preceding embodiments.

[0015] The utility model has the advantages that: by the setting of the first lens, the second lens, the third lens and the fourth lens, the light trend of the head-mounted display optical system is gentle, more light can be introduced to increase the field of view range, and the aberration of the system is effectively corrected, the distortion is reduced, and the imaging quality is improved. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 A structure schematic diagram of the head-mounted display optical system provided by the embodiment of the present application is shown in the figure;

[0017] Figure 2 A point list diagram of the head-mounted display optical system provided by the embodiment of the present application is shown in the figure;

[0018] Figure 3 A field curvature distortion curve diagram of the head-mounted display optical system provided by the embodiment of the present application is shown in the figure;

[0019] Figure 4 A transfer function curve diagram of the head-mounted display optical system provided by the embodiment of the present application is shown in the figure. DETAILED DESCRIPTION

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

[0021] The terms "first" and "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first" and "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise specifically limited.

[0022] In addition, in addition to being used to represent the orientation or positional relationship, the above-mentioned terms can also be used to represent other meanings, for example, the term "upper" can also be used to represent a certain dependent relationship or connection relationship in some cases. For those skilled in the art, the specific meaning of these terms in the present application can be understood according to the specific circumstances.

[0023] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application will be further described in detail below with reference to the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application, and are not used to limit the present application.

[0024] Specifically, the following provides the content of the first aspect of the present application:

[0025] Please refer to Figure 1In the embodiment, the head-mounted display optical system comprises a receiving end 1, a first lens 2, a second lens 3, a third lens 4, a fourth lens 5 and a display 6.

[0026] The display 6 is an organic electroluminescence device or a transmissive liquid crystal display 6 for emitting imaging light. The first lens 2, the second lens 3, the third lens 4 and the fourth lens 5 are all glass lenses. Specifically, the first lens 2, the second lens 3, the third lens 4 and the fourth lens 5 are sequentially arranged between the receiving end 1 and the display 6 along the direction from the receiving end 1 to the display 6; the first lens 2 and the fourth lens 5 are both meniscus lenses convex to the display 6 and have positive focal power, the second lens 3 is a biconvex lens with positive focal power, the third lens 4 is a biconcave lens with negative focal power, and the fourth lens 5 has an even aspheric surface on the side close to the display 6.

[0027] By arranging the first lens 2 with positive focal power, the light collection of the head-mounted display optical system is facilitated, and the field of view can be effectively increased. By arranging the second lens 3 with positive light angle and the third lens 4 with negative focal power, the axial chromatic aberration and the positional chromatic aberration of the head-mounted display optical system can be corrected. By arranging the fourth lens 5 with positive focal power, the fourth lens 5 bears a large focal power of the head-mounted display optical system, can change the propagation direction of the light beam, correct the aberration of the off-axis field of view, and is more conducive to the imaging of the light beam.

[0028] It can be understood that, by arranging the first lens 2, the second lens 3, the third lens 4 and the fourth lens 5, the light trend of the head-mounted display optical system can be gentle, more light can be introduced to increase the field of view, the aberration of the system can be effectively corrected, the distortion can be reduced, and the imaging quality can be improved. At the same time, by arranging the shape of the lens group, the weight and the volume of the head-mounted display optical system can be effectively reduced, the compactness of the optical system can be improved, and the user experience can be improved.

[0029] Further, in an embodiment, the effective focal lengths of the first lens 2, the second lens 3, the third lens 4 and the fourth lens 5 are F1, F2, F3 and F4 respectively, and F1, F2 and F4 are positive, and F3 is negative.

[0030] Specifically, the effective focal length of the head-mounted display optical system is F, and satisfies: 1.47≤F1 / F≤1.83, 1.53≤F2 / F≤1.75, -1.71≤F3 / F≤-1.383, 0.23≤F4 / F≤0.27.

[0031] Further, the refractive indexes of the first lens 2, the second lens 3, the third lens 4 and the fourth lens 5 on the D line are N1, N2, N3 and N4 respectively, and satisfy: 1.78≤N1≤1.82, 1.78≤N2≤1.86, 1.75≤N3≤1.85, 1.62≤N4≤1.89.

[0032] The Abbe numbers of the first lens 2, the second lens 3, the third lens 4 and the fourth lens 5 at the D line are V1, V2, V3 and V4 respectively, and satisfy: 35≤V1≤70, 35≤V2≤65, 20≤V3≤28, 18≤V4≤50.

[0033] The curvature radius of the first lens 2 close to the receiving end 1 is R1, and the curvature radius of the first lens 2 away from the receiving end 1 is R2; the curvature radius of the second lens 3 close to the receiving end 1 is R3, and the curvature radius of the second lens 3 away from the receiving end 1 is R4; the curvature radius of the third lens 4 close to the receiving end 1 is R5, and the curvature radius of the third lens 4 away from the receiving end 1 is R6; the curvature radius of the fourth lens 5 close to the receiving end 1 is R7, and satisfy: -62.5mm≤R1≤-51.7mm, -32.5mm≤R2≤-29mm, 78mm≤R3≤95mm, -143.32mm≤R4≤-115.8mm, -118.4mm≤R5≤-88mm, 95.27mm≤R6≤135.4mm, -55mm≤R7≤-37.6mm.

[0034] The even-order aspheric surface of the fourth lens 5 is a 10th-order aspheric surface. Specifically, the aspheric surface coefficients of the even-order aspheric surface of the fourth lens 5 include a quadratic surface coefficient a1, a fourth-order aspheric surface coefficient a2, a sixth-order aspheric surface coefficient a3, an eighth-order aspheric surface coefficient a4, and a tenth-order aspheric surface coefficient a5. In a preferred embodiment, a1 is -200.05, a2 is 9.551E-007, a3 is -3.16E-009, a4 is 1.2853E-012, and a5 is -2.347E-016.

[0035] Further, the half field of view angle of the head-mounted display optical system is HFOV, and satisfies: 59°≤HFOV≤60°.

[0036] It can be understood that by setting the parameters of the first lens 2, the second lens 3, the third lens 4 and the fourth lens 5, the aberration of the system can be effectively corrected, the distortion can be reduced, the imaging quality can be improved, the weight and volume of the head-mounted display optical system can be reduced, and the compactness of the optical system can be improved.

[0037] Specifically, please refer to Figure 2 , the Figure 2 is a spot diagram of the head-mounted display optical system, which is obtained by Figure 2From the information in the figure, the root mean square radius of the 12 fields of view is 30.880um, 31.800um, 31.332um, 27.243um, 26.910um, 30.160um, 31.920um, 31.585um, 29.241um, 28.004um, 26.912um, 25.414um, all of which are smaller than the size of two pixels and can be accepted by the human eye.

[0038] Referring to Figure 3 , the Figure 3 is a field curvature and distortion curve diagram of the head-mounted display optical system, from Figure 3 , it can be seen that the field curvature of the head-mounted display optical system is less than 1.2mm, and the distortion value within the full field of view does not exceed 22%, which meets the design requirements.

[0039] Referring to Figure 4 , the Figure 4 is a transfer function curve diagram of the head-mounted display optical system, from Figure 4 , it can be seen that the overall imaging quality of the head-mounted display optical system is good, and under the full field of view, the transfer function value of the head-mounted display optical system is 0.2 at 15lp / mm, which meets the image quality requirements.

[0040] In summary, the head-mounted display optical system provided by the present application can make the light trend of the head-mounted display optical system gentle, introduce more light to increase the field of view, effectively correct the aberration of the system, reduce the distortion, and improve the imaging quality, and at the same time, through the setting of the shape of the lens group, the weight and volume of the head-mounted display optical system can be effectively reduced, the compactness of the optical system is improved, and the user's use experience is improved.

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

[0042] The present application provides a VR device, which comprises the aforementioned head-mounted display optical system, and the VR device has good processability, can effectively reduce the weight and volume of the VR device while obtaining relatively good imaging quality, and can effectively improve the user's use experience.

[0043] The above is only a specific embodiment of the present application, and it should be noted that for ordinary skilled persons in the technical field, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements should also be considered as the protection range of the present application.

Claims

1. A head-mounted display optical system, characterized by, The head-mounted display optical system comprises a receiving end, a first lens, a second lens, a third lens, a fourth lens and a display.

2. The head-mounted display optical system of claim 1, wherein The effective focal lengths of the first lens, the second lens, the third lens and the fourth lens are F1, F2, F3 and F4 respectively, and F1, F2 and F4 are positive values, and F3 is a negative value.

3. The head-mounted display optical system of claim 2, wherein, The effective focal length of the head-mounted display optical system is F, and 1.47≤F1 / F≤1.83, 1.53≤F2 / F≤1.75, -1.71≤F3 / F≤-1.383 and 0.23≤F4 / F≤0.27 are satisfied.

4. The head-mounted display optical system of claim 1, wherein, The refractive indexes of the first lens, the second lens, the third lens and the fourth lens at D line are N1, N2, N3 and N4 respectively, and 1.78≤N1≤1.82, 1.78≤N2≤1.86, 1.75≤N3≤1.85 and 1.62≤N4≤1.89 are satisfied.

5. The head-mounted display optical system of claim 1, wherein, The Abbe numbers of the first lens, the second lens, the third lens and the fourth lens at D line are V1, V2, V3 and V4 respectively, and 35≤V1≤70, 35≤V2≤65, 20≤V3≤28 and 18≤V4≤50 are satisfied.

6. The head-mounted display optical system of claim 1, wherein, The half field of view of the head-mounted display optical system is HFOV, and 59°≤HFOV≤60° is satisfied.

7. The head-mounted display optical system of Claim 1, wherein, The curvature radius of the surface of the first lens close to the receiving end is R1, and the curvature radius of the surface of the first lens away from the receiving end is R2; the curvature radius of the surface of the second lens close to the receiving end is R3, and the curvature radius of the surface of the second lens away from the receiving end is R4; the curvature radius of the surface of the third lens close to the receiving end is R5, and the curvature radius of the surface of the third lens away from the receiving end is R6; the curvature radius of the surface of the fourth lens close to the receiving end is R7, and -62.5mm≤R1≤-51.7mm, -32.5mm≤R2≤-29mm, 78mm≤R3≤95mm, -143.32mm≤R4≤-115.8mm, -118.4mm≤R5≤-88mm, 95.27mm≤R6≤135.4mm and -55mm≤R7≤-37.6mm are satisfied.

8. The head-mounted display optical system of claim 1, wherein, The even aspheric surface of the fourth lens is a 10th order aspheric surface.

9. The head-mounted display optical system of claim 1, wherein, The first lens, the second lens, the third lens and the fourth lens are glass lenses.

10. A VR device, comprising: The head-mounted display optical system comprises the head-mounted display optical system according to any one of the preceding claims 1 to 9.

Images