A large aperture, large target surface, wide angle, high and low temperature confocal optical device

Abstract

The invention discloses a large aperture, large target surface, wide angle, high and low temperature confocal optical device. The device comprises a first glass spherical lens L1 with convex-concave negative focal power, a second glass spherical lens L2 with biconcave negative focal power, and a third glass spherical lens L3 with biconvex positive focal power, which are sequentially arranged along the incident direction of light, to form a first cemented lens J1 formed by cementing together; a fourth glass spherical lens L4 with biconvex positive focal power; a fifth plastic aspherical lens L5 with convex-concave negative focal power; a second cemented lens J2 formed by cementing together a sixth glass spherical lens L6 with convex-concave negative focal power and a seventh glass spherical lens L7 with biconvex positive focal power; a third cemented lens J3 formed by cementing together an eighth glass spherical lens L8 with biconvex positive focal power and a ninth glass spherical lens L9 with convex-concave negative focal power; and a tenth glass spherical lens L10 with biconvex positive focal power. The lens adopts a 9G1P structure, which reduces the cost.

Description

Technical Field

[0001] The present invention is mainly aimed at security monitoring and can ensure that the large aperture, large target surface, wide angle, high and low temperature confocal optical device does not defocus at -40°C to 85°C. Background Art

[0002] At present, the domestic closed-circuit surveillance industry (CCTV) is developing in the direction of miniaturization, multi-function, and strong environmental adaptability. In addition, under the situation of fierce domestic competition, fixed-focus lenses can no longer meet the needs of customers in different regions. For example, the market in Northeast my country requires a surveillance device designed to be placed outdoors and not out of focus all year round. The temperature in Northeast my country is often minus 30℃ in winter, and it can reach up to 31℃ in summer. If the circuit heating factor of the surveillance camera is considered, it becomes necessary to design an optical imaging device with a large aperture and a focal plane that does not shift within -40℃ to 85℃. According to authoritative statistics from public security agencies: Nearly 70% of crimes occur at night or in dark areas, and darkness has become a natural umbrella for criminals. In view of the lack of color, unclear details and insufficient brightness of existing cameras under infrared fill light, it is not difficult to find that the current front-end camera image quality under weak light has become a shortcoming in the development of security big data. Therefore, it is necessary to launch a large aperture wide-angle camera that can achieve a "bright, clean and colorful" picture under low illumination. Summary of the invention

[0003] The present invention is mainly aimed at security monitoring and can ensure that the large aperture, large target surface, wide angle, high and low temperature confocal optical device does not defocus at -40°C to 85°C.

[0004] In order to achieve the above design requirements, the technical solution provided by the present invention is as follows:

[0005] 1. A 9G1P glass-plastic hybrid structure high-low temperature cofocal optical device with a focal length of 7 mm, comprising a first glass spherical lens L1 with convex-concave negative focal power, a second glass spherical lens L2 with biconcave negative focal power, and a third glass spherical lens L3 with biconvex positive focal power, which are sequentially arranged along the incident direction of light, to form a first cemented lens J1, a fourth glass spherical lens L4 with biconvex positive focal power, a fifth plastic aspherical lens L5 with convex-concave negative focal power, a sixth glass spherical lens L6 with convex-concave negative focal power, and a seventh glass spherical lens L7 with biconvex positive focal power to form a second cemented lens J2, an eighth glass spherical lens L8 with biconvex positive focal power, and a ninth glass spherical lens L9 with convex-concave negative focal power to form a third cemented lens J3, and a tenth glass spherical lens L10 with biconvex positive focal power; the focal lengths, refractive indices, and curvature radii of the ten glass lenses of the optical device respectively satisfy the following conditions:

[0006] <![CDATA[f1=-11 . 3±5%]]> <![CDATA[n1=1.8±5%]]> <![CDATA[R 11 =150±5%]]> <![CDATA[R 12 =10±5%]]> <![CDATA[f2=-8.2±5%]]> <![CDATA[n2=2.0±5%]]> <![CDATA[R 21 =-11±5%]]> <![CDATA[R 22 =52±5%]]> <![CDATA[f3=15.2±5%]]> <![CDATA[n3=1.7±5%]]> <![CDATA[R 31 =52±5%]]> <![CDATA[R 32 =-14±5%]]> <![CDATA[f4=21.3±5%]]> <![CDATA[n4=1.95±5%]]> <![CDATA[R 41 =48±5%]]> <![CDATA[R 42 =-36±5%]]> <![CDATA[f5=-256.5±5%]]> <![CDATA[n5=1.6±5%]]> <![CDATA[R 51 =16±5%]]> <![CDATA[R 52 =15±5%]]> <![CDATA[f6=-25.3±5%]]> <![CDATA[n6=1.7±5%]]> <![CDATA[R 61 =30±5%]]> <![CDATA[R 62 =11.5±5%]]> <![CDATA[f7=16.6±5%]]> <![CDATA[n7=1.5±5%]]> <![CDATA[R 71 =11.5±5%]]> <![CDATA[R 72 =-25±5%]]> <![CDATA[f8=21.0±5%]]> <![CDATA[n8=1.5±5%]]> <![CDATA[R 81 =71±5%]]> <![CDATA[R 82 =-12±5%]]> <![CDATA[f9=-18.3±5%]]> <![CDATA[n9=1.8±5%]]> <![CDATA[R 91 =-12±5%]]> <![CDATA[R 92 =-54±5% <!-- 1 -->]]> <![CDATA[f 10 =22.0±5%]]> <![CDATA[n 10 =1.6±5%]]> <![CDATA[R 101 =16±5%]]> <![CDATA[R 102 =-70±5%]]>

[0007] Table 1

[0008] In the table above: f1-f 10 The focal lengths of the first glass spherical lens L1 to the tenth glass spherical lens L10 are respectively corresponding to the focal lengths of the first glass spherical lens L1 to the tenth glass spherical lens L10; 10 The refractive indices of the first glass spherical lens L1 to the tenth glass spherical lens L10 are respectively corresponding to the refractive indices of the first glass spherical lens L1 to the tenth glass spherical lens L10; 11 and R 12 Corresponding to the curvature radius of the first glass spherical lens L1, the R 21 and R 22 Corresponding to the curvature radius of the second glass spherical lens L2, the R 31 and R 32 Corresponding to the curvature radius of the third glass spherical lens L3, the R 41 and R 42 Corresponding to the curvature radius of the fourth glass spherical lens L4, the R 61 and R 62 Corresponding to the curvature radius of the sixth glass spherical lens L6, the R 71 and R 72 Corresponding to the curvature radius of the seventh glass spherical lens L7, the R 81 and R 82 Corresponding to the curvature radius of the eighth glass spherical lens L8, the R 91 and R 92 Corresponding to the curvature radius of the ninth glass spherical lens L9, the R 101 and R 102 Corresponding to the curvature radius of the tenth glass spherical lens L10, where “-” indicates the direction is the negative direction.

[0009] The aspheric equation of the plastic aspheric lens L5 satisfies:

[0010]

[0011] In the above formula, parameter c is the radius of curvature, y is the radial coordinate, and k is the coefficient of the conic quadratic curve. The fifth plastic aspheric lens L5 includes a relative R 51 Surface and R 52 The parameters of the surface are as follows:

[0012]

[0013] Table 2

[0014] The sum of the focal power of one plastic aspherical lens and the focal power of five spherical lenses on the image side through the aperture of the present invention is within the following range:

[0015]

[0016] Among them, f5, f6, f7, f8, f9, f 10 , see Table 1.

[0017] The value of FNO. of the present invention is in the following range

[0018]

[0019] Where f is the focal length of the system and D is the entrance pupil diameter.

[0020] The optical device provided by the present invention effectively ensures that the present invention can not be out of focus within the temperature change of -40℃ to 85℃. And the reasonable use of plastic aspheric surface can well improve the edge image quality and ensure high imaging quality. The large aperture enables the lens to form a clear image even in weak light. The wide-angle and large target surface enable the lens to have a large shooting range and clear imaging. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a lens assembly diagram of Embodiment 1 of the present invention.

[0022] Figure 2 This is a schematic diagram of a light path in accordance with a first embodiment of the present invention;

[0023] Figure 3 This is the MTF diagram of the present invention in a low temperature environment of 20°C;

[0024] Figure 4 This is the MTF diagram of the present invention at a normal temperature of -40°C;

[0025] Figure 5 This is the MTF diagram of the present invention under a high temperature environment of 85°C. DETAILED DESCRIPTION

[0026] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and through specific implementation methods. It is understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It is also necessary to explain that, for the convenience of description, only the parts related to the present invention are shown in the accompanying drawings, rather than all the contents.

[0027] See also Figure 1 and Figure 2The present invention comprises a first cemented lens J1 formed by cementing a first glass spherical lens L1 with convex-concave negative focal power, a second glass spherical lens L2 with biconcave negative focal power and a third glass spherical lens L3 with biconvex positive focal power, which are sequentially arranged along the incident direction of light, a fourth glass spherical lens L4 with biconvex positive focal power, a fifth plastic aspherical lens L5 with convex-concave negative focal power, a second cemented lens J2 formed by cementing a sixth glass spherical lens L6 with convex-concave negative focal power and a seventh glass spherical lens L7 with biconvex positive focal power, a third cemented lens J3 formed by cementing an eighth glass spherical lens L8 with biconvex positive focal power and a ninth glass spherical lens L9 with convex-concave negative focal power, and a tenth glass spherical lens L10 with biconvex positive focal power; wherein the lens L1 comprises a relative R 11 Surface and R 12 The lens L2 includes an R 21 Surface and R 22 The lens L3 includes an R 31 Surface and R 32 The lens L4 includes an R 41 Surface and R 42 The lens L5 includes a relative R 51 Surface and R 52 The lens L6 includes an R 61 Surface and R 62 The lens L7 includes an R 71 Surface and R 72 The lens L8 includes an R 81 Surface and R 82 The lens L9 includes an R 91 Surface and R 92 The lens L10 includes an R 101 Surface and R 102 Among them, numbers 1-7 correspond to the mirror surfaces of lenses L1-L4, 8 represents the stop STOP, 9-20 correspond to the mirror surfaces of lenses L5-L10, and 21 represents the image plane.

[0028] When the focal lengths, refractive indices of the ten lenses of the invention and the curvature radii of the nine glass lenses respectively meet the following conditions:

[0029] <![CDATA[f1=-11.3±5%]]> <![CDATA[n1=1.8±5%]]> <![CDATA[R 11 =150±5%]]> <![CDATA[R 12 =10±5%]]> <![CDATA[f2=-8.2±5%]]> <![CDATA[n2=2.0±5%]]> <![CDATA[R 21 =-11±5%]]> <![CDATA[R 22 =52±5%]]> <![CDATA[f3=15.2±5%]]> <![CDATA[n3=1.7±5%]]> <![CDATA[R 31 =52±5%]]> <![CDATA[R 32 =-14±5%]]> <![CDATA[f4=21.3±5%]]> <![CDATA[n4=1.95±5%]]> <![CDATA[R 41 =48±5%]]> <![CDATA[R 42 =-34±5%]]> <![CDATA[f5=-256.5±5%]]> <![CDATA[n5=1.6±5%]]> <![CDATA[R 51 =16±5%]]> <![CDATA[R 52 =15±5%]]> <![CDATA[f6=-25.3±5%]]> <![CDATA[n6=1.7±5%]]> <![CDATA[R 61 =30±5%]]> <![CDATA[R 62 =11.5±5%]]> <![CDATA[f7=16.6±5%]]> <![CDATA[n7=1.5±5%]]> <![CDATA[R 71 =11.5±5%]]> <![CDATA[R 72 =-25±5%]]> <![CDATA[f8=21.0±5%]]> <![CDATA[n8=1.5±5%]]> <![CDATA[R 81 =71±5%]]> <![CDATA[R 82 =-12±5%]]> <![CDATA[f9=-18.3±5%]]> <![CDATA[n9=1.8±5%]]> <![CDATA[R 91 =-12±5%]]> <![CDATA[R 92 =-54±5%]]> <![CDATA[f 10 =22.0±5%]]> <![CDATA[n 10 =1.6±5%]]> <![CDATA[R 101 =16±5%]]> <![CDATA[R 102 =-70±5%]]>

[0030] Table 1

[0031] The aspheric equation of the aspheric lens L5 satisfies:

[0032]

[0033] In the above formula, parameter c is the radius of curvature, y is the radial coordinate, and k is the coefficient of the conic quadratic curve. The aspheric lens L5 includes a relative surface: R 51 Surface, R 52 The parameters of the surface are:

[0034]

[0035] Table 2

[0036] When the focal lengths, refractive indices of the ten lenses of the invention and the curvature radii and thicknesses of the nine glass lenses respectively meet the conditions in Table 1 above, Figure 3 , Figure 4 , Figure 5 It can be seen that the MTF curve of this device does not show serious defocusing phenomenon under extreme conditions such as normal temperature of 20 degrees Celsius, low temperature of -40 degrees Celsius, and high temperature of 85 degrees Celsius.

[0037] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A large aperture, large target surface, wide angle, high and low temperature confocal optical device, characterized in that: The device comprises a first cemented lens J1 formed by cementing a first glass spherical lens L1 with convex-concave negative focal power, a second glass spherical lens L2 with biconcave negative focal power and a third glass spherical lens L3 with biconvex positive focal power, which are sequentially arranged along the incident direction of light, a fourth glass spherical lens L4 with biconvex positive focal power, a fifth plastic aspherical lens L5 with convex-concave negative focal power, a second cemented lens J2 formed by cementing a sixth glass spherical lens L6 with convex-concave negative focal power and a seventh glass spherical lens L7 with biconvex positive focal power, a third cemented lens J3 formed by cementing an eighth glass spherical lens L8 with biconvex positive focal power and a ninth glass spherical lens L9 with convex-concave negative focal power, and a tenth glass spherical lens L10 with biconvex positive focal power; the focal lengths and refractive indices of the ten lenses of the optical device and the curvature radii of the nine glass lenses respectively meet the following conditions: ； In the above table: f1-f10 correspond to the focal lengths of the first glass spherical lens L1 to the tenth glass spherical lens L10 respectively; n1-n10 correspond to the refractive indices of the first glass spherical lens L1 to the tenth glass spherical lens L10 respectively; R11 and R12 correspond to the curvature radius of the first glass spherical lens L1, R21 and R22 correspond to the curvature radius of the second glass spherical lens L2, R31 and R32 correspond to the curvature radius of the third glass spherical lens L3, R41 and R42 correspond to the curvature radius of the fourth glass spherical lens L4. R51 and R52 correspond to the curvature radius of the fifth plastic aspherical lens L5, R61 and R62 correspond to the curvature radius of the sixth glass spherical lens L6, R71 and R72 correspond to the curvature radius of the seventh glass spherical lens L7, R81 and R82 correspond to the curvature radius of the eighth glass spherical lens L8, R91 and R92 correspond to the curvature radius of the ninth glass spherical lens L9, and R101 and R102 correspond to the curvature radius of the tenth glass spherical lens L10, wherein "-" indicates that the direction is the negative direction; The aspheric surface equation of the fifth plastic aspheric lens L5 with convex-concave negative optical power satisfies: ； In the above formula, parameter c is the radius of curvature, y is the radial coordinate, and k is the coefficient of the conic quadratic curve. The fifth plastic aspheric lens L5 includes opposite surfaces R51 and R52, and the parameters are as follows: ； The sum of the focal power of one plastic aspherical lens and five spherical lenses on the image side of the aperture is in the following range: 。 2. A large aperture, large target surface, wide angle, high and low temperature confocal optical device as claimed in claim 1, characterized in that: Also meets the following conditions: The value of FNO. is in the following range: ； Where f is the focal length of the system and D is the entrance pupil diameter.

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