CN215264200U

CN215264200U - Line scanning lens

Info

Publication number: CN215264200U
Application number: CN202121034423.7U
Authority: CN
Inventors: 陈健兵; 周琪; 徐勇; 徐梦颖; 詹林敏
Original assignee: Jiangxi Gaorui Photoelectric Co ltd
Current assignee: Jiangxi Gaorui Photoelectric Co ltd
Priority date: 2021-05-14
Filing date: 2021-05-14
Publication date: 2021-12-21
Anticipated expiration: 2031-05-14

Abstract

The utility model provides a line scanning lens, optical system is by the object space to the image space in proper order including the first lens G1 that has negative focal power and biconcave surface structure, the second lens G2 that has positive focal power and biconvex surface structure, the third lens G3 that has positive focal power and falcate structure, the fourth lens G4 that has positive focal power and falcate structure, the fifth lens G5 that has negative focal power and falcate structure, the sixth lens G6 that has negative focal power and falcate structure, the seventh lens G7 that has positive focal power and falcate structure, fourth lens G4 with the combination of fifth lens G5 forms the battery of lens group U1 that has positive focal power, the utility model discloses a line scanning lens and whole group focus mode have high resolution, big target surface, the application needs of low distortion, satisfy high-end product demand, but its clear aperture is nimble to be adjusted simultaneously.

Description

Line scanning lens

Technical Field

The utility model belongs to the technical field of the camera lens technique and specifically relates to indicate a camera lens is swept to line.

Background

Machine vision is to use a machine to replace human eyes for measurement and judgment. Currently, line scan lenses are an important component of many machine vision systems. In precision detection applications such as electronic manufacturing, liquid crystal display size measurement, circuit board pin detection and the like, a line scanning lens is often adopted to match with a line scan camera to obtain images, and clear and accurate acquisition of real images through the lens is the basis of subsequent image analysis processing. The linear scanning lens in the current market has poor expression in the aspects of imaging definition and distortion rate, and cannot meet the application requirements of high resolution, large rake face, low distortion and the like in the time of day and night.

SUMMERY OF THE UTILITY MODEL

Technical problem to be solved

An object of the utility model is to provide a camera lens is swept to line adopts the line to sweep camera lens and whole group's mode of focusing, has the performance of high resolution, big target surface, low distortion, satisfies high-end product demand. In order to achieve the above purpose, the utility model adopts the following technical scheme:

(II) technical scheme

A line-scanning lens comprises an optical system, wherein the optical system sequentially comprises a first lens G1 with negative focal power and a biconcave surface structure, a second lens G2 with positive focal power and a biconvex surface structure, a third lens G3 with positive focal power and a meniscus structure, a fourth lens G4 with positive focal power and a meniscus structure, a fifth lens G5 with negative focal power and a meniscus structure, a sixth lens G6 with negative focal power and a meniscus structure, and a seventh lens G7 with positive focal power and a meniscus structure from an object side to an image side, the fourth lens G4 and the fifth lens G5 are combined to form a cemented lens group U1 with positive focal power, the focal length of the optical system is f, and the focal length f of the optical system is equal to the focal length f of the cemented lens group U1_U1Satisfies the relationship: 0.5<|f_U1/f|<1.5。

Further, a distance L from a vertex of a front surface of the first lens G1 to a vertex of a rear surface of the seventh lens G7 and a focal length f of the optical system satisfy the relation: 0.8 < | L/f | < 2.

Further, the optical back intercept BFL of the optical system and the focal length f of the optical system satisfy the relation: 0.5 < | BFL/f | < 1.

Further, the half-image height y' of the optical system and the focal length f of the optical system satisfy the relation: i y'/f I is less than 1.

Further, the refractive index of the first lens G1 is n₁Refractive index n of₁Satisfy the relation: n is more than 1.5₁＜1.7。

Further, the refractive index of the second lens G2 is n₂Having a focal length f_G2，Its refractive index n₂Satisfy the relation: 1.75 < n₂Less than 1.85; its focal length f_G2The ratio of f to f satisfies the relation: 0.5 < | f_G2/f|＜2。

Further, the third lens G3 has a focal length f_G3The focal length of the fourth lens G4 is f_G4Focal length f thereof_G3And f_U1Ratio of (a) to (b), f_G4And f_U1The ratio of (A) and (B) simultaneously satisfies the relation: 2 < | f_G3/f_U1|＜3、 0.15＜|f_G4/f_U1|＜0.5。

Further, the refractive index of the fifth lens G5 is n₅Refractive index n of₅Satisfy the relation: 1.4 < n₅＜1.9。

The diaphragm is arranged between the third lens G3 and the fourth lens G4, the hole of the diaphragm is a round hole, and the aperture of the diaphragm is adjustable within the range of F4-F16.

(III) advantageous effects

Compared with the prior art, the utility model have obvious advantage and beneficial effect, particularly, the utility model discloses above-mentioned structure has realized that the focus is 40 mm's line and has swept the optical system of machine vision camera lens, and image space F number is 4.0, and the biggest imaging surface is phi 62.7mm, has the performance of high resolution, big target surface, low distortion, satisfies high-end product demand, adopts the whole group mode of focusing, and its clear aperture is also nimble to be adjusted.

Drawings

Fig. 1 is a schematic structural diagram of the present invention.

Fig. 2 is a light path diagram of an optical system according to an embodiment of the present invention.

Fig. 3 is a distortion curve diagram of an optical system in an embodiment of the present invention.

The reference numbers illustrate:

0-optical system G1-first lens G2-second lens G3-third lens

G4-fourth lens G5-fifth lens G6-sixth lens G7-seventh lens

8-diaphragm U1-first cemented lens

L-distance from vertex of front surface of first lens to vertex of rear surface of eighth lens

Optical back intercept of BFL-optical system

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary and intended to be used for explaining the present invention, and should not be construed as limiting the present invention.

The present invention will be further described with reference to the accompanying drawings and the detailed description.

Referring to fig. 1, a line-scanning lens includes an optical system, where the optical system 0 includes, in order from an object side to an image side, a first lens G1 having a negative focal power and a biconcave surface structure, a second lens G2 having a positive focal power and a biconvex surface structure, a third lens G3 having a positive focal power and a meniscus structure, a fourth lens G4 having a positive focal power and a meniscus structure, a fifth lens G5 having a negative focal power and a meniscus structure, a sixth lens G6 having a negative focal power and a meniscus structure, and a seventh lens G7 having a positive focal power and a meniscus structure, the fourth lens G4 and the fifth lens G5 form a cemented lens group U1 having a positive focal power, a focal length of the optical system 0 is f, and a focal length f of the cemented lens group U1_U1Satisfies the relationship: 0.5<|f_U1/f|<1.5。

Preferably, a distance L from a vertex of a front surface of the first lens G1 to a vertex of a rear surface of the seventh lens G7 and a focal length f of the optical system satisfy the following relation: 0.8 < | L/f | < 2.

Preferably, the optical back intercept BFL of the optical system and the focal length f of the optical system satisfy the relation: 0.5 < | BFL/f | < 1.

Preferably, the half-image height y' of the optical system and the focal length f of the optical system satisfy the relation: i y'/f I is less than 1.

Preferably, the refractive index of the first lens G1 is n₁Refractive index n of₁Satisfy the relation: n is more than 1.5₁＜1.7。

Preferably, the refractive index of the second lens G2 is n₂Having a focal length f_G2，Its refractive index n₂Satisfy the relation: 1.75 < n₂Less than 1.85; its focal length f_G2The ratio of f to f satisfies the relation: 0.5 < | f_G2/f|＜2。

Preferably, the third lens G3 has a focal length f_G3The focal length of the fourth lens G4 is f_G4Focal length f thereof_G3And f_U1Ratio of (a) to (b), f_G4And f_U1The ratio of (A) and (B) simultaneously satisfies the relation: 2 < | f_G3/f_U1|＜3、 0.15＜|f_G4/f_U1|＜0.5。

Preferably, the refractive index of the fifth lens G5 is n₅Refractive index n of₅Satisfy the relation: 1.4 < n₅＜1.9。

Preferably, the optical disc further comprises a diaphragm 8, the diaphragm 8 is arranged between the third lens G3 and the fourth lens G4, the hole of the diaphragm 8 is a circular hole, and the aperture of the diaphragm 8 is adjustable in the range of F4.0-F16.

In this example, optical system 0 data is as follows:

in this example, the focal length F of the optical system 0 is 40mm, the maximum aperture is F # -4.0, and the focal length F of the first cemented lens group U1_U135.81mm, the distance L from the front surface vertex of the first lens G1 to the rear surface vertex of the seventh lens G7 is 54.51mm, the optical back intercept BFL is 31.12mm, the half-image height y' is 31.35mm, and the focal length f of the third lens G3_G383.87mm, focal length f of fourth lens G4_G413.93mm, focal length f of fifth lens G5_G5-24.59mm, focal length f of sixth lens G6_G6-22.57mm, focal length f of seventh lens G7_G7＝47.71mm。

Will the embodiment of the present invention obtains fig. 2 and fig. 3 through the test, fig. 2 is the embodiment of the present invention provides an optical path diagram of an optical system and an optical distortion curve diagram of the embodiment shown in fig. 3, and it can be seen from fig. 3 that the maximum optical distortion in the full view field range is lower than 1%.

The utility model discloses above-mentioned structure has realized that the focus is 40 mm's optical system that machine vision camera lens was swept to line, and image space F number is 4.0, and the biggest image plane is phi 62.7mm, has the performance of high resolution, big target surface, low distortion, satisfies high-end product demand, adopts whole group's mode of focusing, and its clear aperture also can be adjusted in a flexible way.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the technical scope of the present invention, so that any slight modifications, equivalent changes and modifications made by the technical spirit of the present invention to the above embodiments are all within the scope of the technical solution of the present invention.

Claims

1. A line scanning lens comprises an optical system, and is characterized in that: the optical system comprises a first lens G1 with negative focal power and a biconcave surface structure, a second lens G2 with positive focal power and a biconvex surface structure, and a lens with positive focal power and a meniscus junction in sequence from an object side to an image sideThe third lens G3 of the structure, the fourth lens G4 with positive focal power and a meniscus structure, the fifth lens G5 with negative focal power and a meniscus structure, the sixth lens G6 with negative focal power and a meniscus structure, the seventh lens G7 with positive focal power and a meniscus structure, the fourth lens G4 and the fifth lens G5 are combined to form a cemented lens group U1 with positive focal power, the focal length of the optical system is f, and the focal length f of the optical system and the focal length f of the cemented lens group U1_U1Satisfies the relationship: 0.5<|f_U1/f|<1.5。

2. The linear scanning lens according to claim 1, wherein: the distance L from the vertex of the front surface of the first lens G1 to the vertex of the rear surface of the seventh lens G7 and the focal length f of the optical system satisfy the following relation: 0.8 < | L/f | < 2.

3. A line-scanning lens according to claim 1 or 2, wherein: the optical back intercept BFL of the optical system and the focal length f of the optical system satisfy the relation: 0.5 < | BFL/f | < 1.

4. A line-scanning lens according to claim 1 or 2, wherein: the half-image height y' of the optical system and the focal length f of the optical system satisfy the relation: i y'/f I is less than 1.

5. The linear scanning lens according to claim 1, wherein: the refractive index of the first lens G1 is n₁Refractive index n of₁Satisfy the relation: n is more than 1.5₁＜1.7。

6. A line scanning lens according to claim 1 or 5, wherein: the refractive index of the second lens G2 is n₂Having a focal length f_G2，Its refractive index n₂Satisfy the relation: 1.75 < n₂Less than 1.85; its focal length f_G2The ratio of f to f satisfies the relation: 0.5 < | f_G2/f|＜2。

7. A line scanning lens according to claim 1 or 5, wherein: the focal length of the third lens G3 is f_G3The focal length of the fourth lens G4 is f_G4Focal length f thereof_G3And f_U1Ratio of (a) to (b), f_G4And f_U1The ratio of (A) and (B) simultaneously satisfies the relation: 2 < | f_G3/f_U1|＜3、0.15＜|f_G4/f_U1|＜0.5。

8. The linear scanning lens according to claim 1, wherein: the refractive index of the fifth lens G5 is n₅Refractive index n of₅Satisfy the relation: 1.4 < n₅＜1.9。

9. The linear scanning lens according to claim 1, wherein: the diaphragm is arranged between the third lens G3 and the fourth lens G4, the hole of the diaphragm is a round hole, and the aperture of the diaphragm is adjustable within the range of F4.0-F16.