CN209765151U

CN209765151U - Double telecentric lens with double vision fields

Info

Publication number: CN209765151U
Application number: CN201920741211.9U
Authority: CN
Inventors: 叶文炜; 林峰; 王敏
Original assignee: Fujian Normal University
Current assignee: Fujian Normal University
Priority date: 2019-05-22
Filing date: 2019-05-22
Publication date: 2019-12-10
Anticipated expiration: 2029-05-22

Abstract

The utility model relates to a two telecentric mirror heads with two fields of vision, include protection glass, front group S1, rear group S2 and rear group S3 along thing side to image side in proper order among the optical system of camera lens, the system is on same working plane, images in the visual field of equidimension not, makes it have two different magnification simultaneously to system' S compact structure has characteristics that the degree of telecentricity is high, the distortion becomes low, imaging resolution is high.

Description

Double telecentric lens with double vision fields

Technical Field

The utility model relates to a two telecentric mirror heads with two fields of vision belongs to machine vision photoelectric imaging technical field.

Background

Compared with manual detection, machine vision has stronger adaptability and higher stability, and can well make up the defects of human eyes in the aspects of resolution capability, photosensitive range, response speed and the like. In a machine vision system, the imaging lens part directly determines the performance of the system to a large extent, and the imaging quality directly influences the processing speed and the identification precision of the subsequent software processing part. Compared with a common lens, the double-telecentric lens has the advantages of low distortion, large depth of field, parallax elimination and the like, so that the double-telecentric lens is widely applied to the field of machine vision precision measurement. However, the conventional detection instrument can only be equipped with one optical lens, can only realize magnification of one multiple, and when different multiples are required for measurement, the optical lens of another multiple needs to be replaced and re-corrected, the process of replacing the lens is very complicated, the working time is prolonged, the repeated positioning precision after replacing the lens cannot be completely guaranteed, and the detection data cannot be integrated with the data before replacing the lens for analysis. Aiming at the existing defects, the double-telecentric design scheme of double visual fields is provided, so that the double-telecentric design scheme can have two different magnification factors on the same lens, and the applicability of a telecentric system is improved.

SUMMERY OF THE UTILITY MODEL

In view of the not enough of prior art, the utility model aims to solve the technical problem that a two telecentric mirror heads with two fields of vision are provided, not only simple structure, convenient high efficiency moreover.

in order to solve the technical problem, the technical scheme of the utility model is that: a double telecentric lens with double fields of view is characterized in that: the optical system of the lens comprises a protective glass, a front group S1, a rear group S2 and a rear group S3 in sequence from the object side to the image side;

The front group S1 includes, in order from the object side to the image side: protective glass having no optical power, a first lens G1 having positive bending power, a second lens G2 having negative bending power, a third lens G3 having positive bending power, a fourth lens G4 having positive bending power, a fifth lens G5 having negative bending power, and a sixth lens G6 having positive bending power;

The rear group S2 includes, in order from the object side to the image side: a double cemented lens in which the seventh lens G7 having a positive bending force is in close contact with the eighth lens G8 having a negative bending force; a ninth lens G9 having a positive refracting power, a tenth lens G10 having a positive refracting power, an eleventh lens G11 having a negative refracting power;

The rear group S3 includes, in order from the object side to the image side: a double cemented lens in which the seventh lens G7 'having a positive bending force is closely attached to the eighth lens G8' having a negative bending force; a ninth lens G9 ' having a positive refracting power, a tenth lens G10 ' having a positive refracting power, and an eleventh lens G11 ' having a negative refracting power;

The front group S1 and the rear group S2 are coaxial in light path, and the rear group S3 and the rear group S2 are perpendicular in light path.

preferably, the front group S1, the rear group S2 and the rear group S3 are connected together through a cube prism formed by combining two triangular prisms, and both binding surfaces of the triangular prisms are required to be plated with semi-transparent and semi-reflective films.

Preferably, the lens can simultaneously image two different line fields of view on the same working plane, and the magnification is different, and the object space line fields of view are respectively 80mm and 40 mm.

Preferably, the maximum clear aperture of the lens satisfies FNO <10, where FNO is the maximum clear aperture F number.

Preferably, the back intercept of the lens is BFL, the total length of the system is TOR, and both structures meet BFL/TOR > 0.05.

Preferably, the thickness D of the cube prism is 15, and the distance D from the last lens of the front group S1 to the cube prism is D, D >10 mm.

Preferably, the lens clear aperture is a circular aperture, which reaches the rear group S2 and rear group S3 by a distance T, T >1 mm.

preferably, all lenses of the lens are spherical lenses.

Compared with the prior art, the utility model discloses following beneficial effect has: the double-telecentric lens with the double fields of view has a simple structure, and images two different fields of view on the same working plane on the basis of keeping the double telecentricity of the system, so that the system has two different magnification ratios, and the applicability of the telecentric system is improved. The whole system has the characteristics of compact structure, high resolution, small distortion and the like.

The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

drawings

Fig. 1 is a schematic view of an optical system according to an embodiment of the present invention.

Fig. 2 is a graph of MTF at-0.1375X according to an embodiment of the present invention.

fig. 3 is a graph of MTF at-0.275X for an embodiment of the present invention.

Fig. 4 is a system distortion diagram at-0.1375X according to the embodiment of the present invention.

Fig. 5 is a diagram of system distortion at-0.275X according to an embodiment of the present invention.

Fig. 6 is a system diagram at-0.1375X according to an embodiment of the present invention.

fig. 7 is a system diagram at-0.275X according to an embodiment of the present invention.

In the figure: 1-protective glass, 2-cube prism, S1-front group S1, S2-rear group S2, S3-rear group S3, G1-first lens G1, G2-second lens G2, G3-third lens G3, G4-fourth lens G4, G5-fifth lens G5, G6-sixth lens G6, G7-seventh lens G7, G8-eighth lens G8, G9-ninth lens G9, G10-tenth lens G10, G11-eleventh lens G11.

Detailed Description

In order to make the aforementioned and other features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.

As shown in fig. 1 ~ 7, a double telecentric lens with double fields of view is characterized in that the optical system of the lens comprises a protective glass 1, a front group S1, a rear group S2 and a rear group S3 in sequence from the object side to the image side;

In the embodiment of the present invention, the front set S1 is connected to the rear set S2 and the rear set S3 through a cube prism 2 combined by two triangular prisms, and two binding surfaces of the triangular prisms are all plated with semi-transparent and semi-reflective films.

The embodiment of the utility model provides an in, the camera lens can be to two different line visual fields simultaneous imaging on same working plane, and magnification is different, and its object space line visual field is 80mm and 40mm respectively.

In the embodiment of the utility model, the biggest clear aperture of camera lens satisfies FNO <10, and wherein FNO is the biggest clear aperture F number.

In the embodiment of the utility model, the back intercept of camera lens is BFL, and the total length of system is TOR, and BFL/TOR >0.05 is all satisfied to two structures.

in the embodiment of the utility model provides an in, the thickness D of square prism is 15, and the last lens of front group S1 is D to the distance of square prism, and D >10 mm.

in the embodiment of the utility model, the clear aperture of camera lens is circular aperture, and its distance that reachs back group S2 and back group S3 is T, and T >1 mm.

In the embodiment of the present invention, all the lenses of the lens are spherical lenses.

The present invention is not limited to the above preferred embodiments, and any person can obtain other various forms of double telecentric lens with double vision fields under the teaching of the present invention. All the equivalent changes and modifications made according to the claims of the present invention shall fall within the scope of the present invention.

Claims

1. A double telecentric lens with double fields of view is characterized in that: the optical system of the lens comprises a protective glass, a front group S1, a rear group S2 and a rear group S3 in sequence from the object side to the image side;

2. Double telecentric lens with double field of view according to claim 1, characterized in that: the front group S1, the rear group S2 and the rear group S3 are connected together through a cube prism combined by two triangular prisms, and two binding surfaces of the triangular prisms are both plated with semi-transparent and semi-reflective films.

3. Double telecentric lens with double field of view according to claim 1, characterized in that: the lens can simultaneously image two different line view fields on the same working plane, the magnification is different, and the object space line view fields are respectively 80mm and 40 mm.

4. Double telecentric lens with double field of view according to claim 1, characterized in that: the maximum clear aperture of the lens satisfies FNO <10, wherein FNO is the maximum clear aperture F number.

5. Double telecentric lens with double field of view according to claim 1, characterized in that: the back intercept of the lens is BFL, the total length of the system is TOR, and the two structures both meet BFL/TOR > 0.05.

6. Double telecentric lens with double field of view according to claim 1, characterized in that: the thickness D of the cube prism is 15, and the distance from the last lens of the front group S1 to the cube prism is D, D >10 mm.

7. double telecentric lens with double field of view according to claim 1, characterized in that: the lens clear aperture is a circular aperture that reaches rear group S2 and rear group S3 a distance T, T >1 mm.

8. Double telecentric lens with double field of view according to claim 1, characterized in that: all lenses of the lens are spherical lenses.