阅读说明：本技术 一种双倍率的双远心镜头 (Double-telecentric lens with double multiplying power ) 是由 刘凌鸿 冯云 于 2021-08-18 设计创作，主要内容包括：本发明涉及光学装置技术领域,具体公开了一种双倍率的双远心镜头,包括光学镜片从物方到像方依次由双凸结构的第一物镜和弯月结构的第二物镜组成物镜组；5：5分光的第三透镜；依次由弯月结构的第四透镜,双凹结构的第五透镜,双凸结构的第六透镜,双凸结构的第七透镜组成后透镜组一,后透镜组一具有第一像面；依次由双凸结构的第八透镜,双凹结构的第九透镜,双凸结构的第十透镜,弯月结构的第十一透镜组成后透镜组二,后透镜组二具有第二像面。通过上述结构设置,能够使得双倍率的双远心镜头的结构设计更加合理,使用效果更好。(The invention relates to the technical field of optical devices, and particularly discloses a double-magnification double telecentric lens, which comprises an optical lens, wherein an objective lens group is formed by a first objective lens with a double-convex structure and a second objective lens with a meniscus structure from an object space to an image space; 5: a third lens for splitting light; the first rear lens group is composed of a fourth lens with a meniscus structure, a fifth lens with a biconcave structure, a sixth lens with a biconvex structure and a seventh lens with a biconvex structure in sequence and is provided with a first image surface; and the rear lens group II is composed of an eighth lens with a biconvex structure, a ninth lens with a biconcave structure, a tenth lens with a biconvex structure and an eleventh lens with a meniscus structure in sequence, and is provided with a second image surface. Through the structure setting, the structural design of the double telecentric lens with double multiplying power is more reasonable, and the using effect is better.)

1. A double telecentric lens with double magnification is characterized in that,

the optical lens comprises an objective lens group consisting of a first objective lens with a biconvex structure and a second objective lens with a meniscus structure from an object space to an image space;

5: a third lens for splitting light;

the first rear lens group is composed of a fourth lens with a meniscus structure, a fifth lens with a biconcave structure, a sixth lens with a biconvex structure and a seventh lens with a biconvex structure in sequence, and the first rear lens group is provided with a first image surface;

and the rear lens group II is composed of an eighth lens with a biconvex structure, a ninth lens with a biconcave structure, a tenth lens with a biconvex structure and an eleventh lens with a meniscus structure in sequence, and the rear lens group II is provided with a second image surface.

2. The double-magnification double telecentric lens according to claim 1,

the double-telecentric lens with double multiplying power further comprises a first objective lens barrel, a first objective lens pressing ring and a second objective lens pressing ring, wherein the first objective lens barrel is fixedly connected with the first objective lens barrel through the first objective lens pressing ring, and the second objective lens is fixedly connected with the first objective lens barrel through the second objective lens pressing ring.

3. The double-magnification double telecentric lens according to claim 2,

the double-telecentric lens with double multiplying powers further comprises a second objective lens barrel and a spectroscope base, wherein one end of the second objective lens barrel is fixedly connected with the first objective lens barrel, and the other end of the second objective lens barrel is in screwed connection with the spectroscope base.

4. The double-magnification double telecentric lens according to claim 3,

the double-telecentric lens with double multiplying powers further comprises a first rear lens barrel and a second rear lens barrel, wherein one end of the beam splitter base along the optical axis is in threaded connection with the first rear lens barrel, and one end of the beam splitter base perpendicular to the optical axis is in threaded connection with the second rear lens barrel.

5. The double-magnification double telecentric lens according to claim 4,

the double-telecentric lens with double multiplying powers further comprises a semi-transparent and semi-reflective seat, the semi-transparent and semi-reflective seat is arranged in the spectroscope seat, and the third lens is arranged on the semi-transparent and semi-reflective seat and placed in the spectroscope seat at an angle of 45 degrees with the optical axis.

6. The double-magnification double telecentric lens according to claim 5,

the fourth lens, the fifth lens, the sixth lens and the seventh lens are sequentially arranged in the first rear lens barrel;

the eighth lens, the ninth lens, the tenth lens, and the eleventh lens are mounted in the rear lens barrel two in this order.

7. The double-magnification double telecentric lens according to claim 6,

a first spacer is arranged between the fourth lens and the fifth lens, and a second spacer is arranged between the fifth lens and the sixth lens.

8. The double-magnification double telecentric lens according to claim 7,

the double-telecentric lens with double multiplying powers further comprises a first pressing ring, a second pressing ring, a first lens seat and a second lens seat, wherein the first lens seat and the second lens seat are arranged in the first rear lens barrel, the fourth lens, the fifth lens and the sixth lens are arranged in the first lens seat and fixed through the first pressing ring, and the seventh lens is arranged in the second lens seat and fixed through the second pressing ring.

9. The double-magnification double telecentric lens according to claim 8,

a third spacer is disposed between the eighth lens element and the ninth lens element, and a fourth spacer is disposed between the ninth lens element and the tenth lens element.

10. The double-magnification double telecentric lens according to claim 9,

the double-telecentric lens with double multiplying powers further comprises a third pressing ring, a third lens seat and a fourth lens seat, wherein the third lens seat and the fourth lens seat are arranged in the second rear lens barrel, the eighth lens, the ninth lens and the tenth lens are placed in the third lens seat and fixed through the third pressing ring, and the eleventh lens is placed in the fourth lens seat and fixed through the third pressing ring.

Technical Field

The invention relates to the technical field of optical devices, in particular to a double-telecentric lens with double magnification.

Background

In a machine vision precision measurement system, the problems of different magnification ratios, aberration, large distortion and the like caused by the change of object distance exist in a common industrial lens, and in order to meet the requirement of high-precision detection, the telecentric lens can be in a certain object distance range, so that the image magnification ratio is basically kept unchanged. In the detection, capture, tracking and measurement of targets in the detection field, a zoom optical system is required to meet the requirements of testing in a large-view-field range of the targets and the capability of distinguishing details of small views of the targets, different views are required to be shot simultaneously, and a common zoom lens and a telecentric lens cannot meet the detection requirements simultaneously, so that a double-magnification double-telecentric lens is produced.

However, the existing double-magnification double-telecentric lens has unreasonable structural design and poor use effect.

Disclosure of Invention

The invention aims to provide a double-magnification double-telecentric lens, and aims to solve the technical problems that the structural design of the double-magnification double-telecentric lens in the prior art is unreasonable and the use effect is poor.

In order to achieve the purpose, the double-magnification double-telecentric lens adopted by the invention comprises an optical lens, wherein an objective lens group is formed by a first objective lens with a double-convex structure and a second objective lens with a meniscus structure from an object space to an image space;

5: a third lens for splitting light;

the first rear lens group is composed of a fourth lens with a meniscus structure, a fifth lens with a biconcave structure, a sixth lens with a biconvex structure and a seventh lens with a biconvex structure in sequence, and the first rear lens group is provided with a first image surface;

and the rear lens group II is composed of an eighth lens with a biconvex structure, a ninth lens with a biconcave structure, a tenth lens with a biconvex structure and an eleventh lens with a meniscus structure in sequence, and the rear lens group II is provided with a second image surface.

The double-telecentric lens with double multiplying power further comprises a first objective lens barrel, a first objective lens pressing ring and a second objective lens pressing ring, wherein the first objective lens barrel is fixedly connected with the first objective lens barrel through the first objective lens pressing ring, and the second objective lens is fixedly connected with the first objective lens barrel through the second objective lens pressing ring.

The double-telecentric lens with double multiplying powers further comprises a second objective lens barrel and a light splitting lens base, one end of the second objective lens barrel is fixedly connected with the first objective lens barrel, and the other end of the second objective lens barrel is in screwed connection with the light splitting lens base.

The double-telecentric lens with double multiplying powers further comprises a first rear lens barrel and a second rear lens barrel, one end of the beam splitter base along the optical axis is in threaded connection with the first rear lens barrel, and one end of the beam splitter base perpendicular to the optical axis is in threaded connection with the second rear lens barrel.

The double-telecentric lens with double multiplying powers further comprises a semi-transparent and semi-reflective seat, the semi-transparent and semi-reflective seat is arranged in the spectroscope seat, and the third lens is arranged on the semi-transparent and semi-reflective seat and placed in the spectroscope seat at an angle of 45 degrees with the optical axis.

The fourth lens, the fifth lens, the sixth lens and the seventh lens are sequentially arranged in the first rear lens barrel;

the eighth lens, the ninth lens, the tenth lens, and the eleventh lens are mounted in the rear lens barrel two in this order.

And a first spacer is arranged between the fourth lens and the fifth lens, and a second spacer is arranged between the fifth lens and the sixth lens.

The double-telecentric lens with double magnifications further comprises a first pressing ring, a second pressing ring, a first lens seat and a second lens seat, wherein the first lens seat and the second lens seat are arranged in the first rear lens barrel, the fourth lens, the fifth lens and the sixth lens are placed in the first lens seat and fixed through the first pressing ring, and the seventh lens is placed in the second lens seat and fixed through the second pressing ring.

A third spacer is disposed between the eighth lens and the ninth lens, and a fourth spacer is disposed between the ninth lens and the tenth lens.

The double-telecentric lens with double magnifications further comprises a third pressing ring, a third lens seat and a fourth lens seat, wherein the third lens seat and the fourth lens seat are arranged in the second rear lens barrel, the eighth lens, the ninth lens and the tenth lens are placed in the third lens seat and fixed through the third pressing ring, and the eleventh lens is placed in the fourth lens seat and fixed through the third pressing ring.

The double-magnification double-telecentric lens has the following beneficial effects: the structure is simple, the volume is small, only two objective lenses are used, the loss of optical energy is reduced, and the manufacturing cost is reduced; and the third lens is used for dividing the light beam into two directions in an average way, two beams of light respectively pass through two groups of rear lens groups and respectively correspond to two multiplying powers, the low multiplying power meets the requirement of large-view-field detection, and the high multiplying power meets the requirement of small-view-field high-precision detection. In addition, when the lens is at the working distance of 100mm and in the temperature range of 0-100 ℃, and the MTF of 2 multiplying powers is larger than 0.5 at the position of 100 lp/mm; the distortion of the first multiplying power in the whole field range is less than 0.05%, the distortion of the second multiplying power is less than 0.03%, the magnification of the field depth within 10mm is kept unchanged, and the influence of temperature difference change on imaging is small. The double-telecentric lens with double multiplying power has more reasonable structural design and better use effect.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is an assembly view of a double-magnification double telecentric lens of the present invention.

Fig. 2 is a schematic view of the structure of each group of lenses of the invention.

FIG. 3 is a graph of MTF at 20 ℃ magnification according to the present invention.

FIG. 4 is a graph of MTF at 0 ℃ magnification according to the present invention.

FIG. 5 is a graph of MTF at 50 ℃ magnification according to the present invention.

FIG. 6 is a graph of MTF at 100 ℃ magnification according to the present invention.

FIG. 7 is a plot of field curvature versus distortion at 20 ℃ magnification in accordance with the present invention.

FIG. 8 is a graph of field curvature and distortion at 0 ℃ magnification in accordance with the present invention.

FIG. 9 is a plot of field curvature versus distortion at 50 ℃ magnification in accordance with the present invention.

FIG. 10 is a plot of field curvature versus distortion at 100 ℃ magnification in accordance with the present invention.

FIG. 11 is a graph showing MTF at 20 ℃ magnification according to the present invention.

FIG. 12 is a graph showing MTF at 0 ℃ magnification according to the present invention.

FIG. 13 is a graph showing MTF at magnification of two 50 ℃ according to the present invention.

FIG. 14 is a graph showing MTF at 100 ℃ magnification according to the present invention.

FIG. 15 is a graph of field curvature and distortion at 20 ℃ magnification in accordance with the present invention.

FIG. 16 is a graph showing the field curvature and distortion curve at magnification of two 0 ℃ in accordance with the present invention.

FIG. 17 is a graph showing the field curvature and distortion curve at a magnification of two 50 ℃ according to the present invention.

FIG. 18 is a graph showing the field curvature and distortion curve at a magnification of two 100 ℃ according to the present invention.

1. The lens comprises an objective lens barrel I, an objective lens barrel II, an objective lens pressing ring II, an objective lens pressing ring I, an objective lens barrel II, a semi-transparent and semi-reflective seat 7, a third lens 8, a beam splitter seat 9, a rear lens barrel I11, a lens seat I, a fourth lens 12, a spacer ring I13, a spacer ring I, a fifth lens 14, a spacer ring II 15, a sixth lens 16, a spacer ring I, a lens seat II, a seventh lens 19, a spacer ring II, a focusing ring 21, a standard C joint 23, a rear lens barrel II, a rear lens barrel III, a lens seat III, an eighth lens 25, a spacer ring III, a ninth lens 27, a spacer ring IV, a tenth lens 29, a pressing ring III, a pressing ring 31, a lens seat IV and an eleventh lens 32.

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 or similar 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 illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

In the description of the present invention, it is to be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on the orientations or positional relationships illustrated in the drawings, and are used merely for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, are not to be construed as limiting the present invention. Further, in the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

Referring to fig. 1 to 18, the present invention provides a double-magnification double telecentric lens, which comprises an optical lens, an objective lens group consisting of a first objective lens 4 with a biconvex structure and a second objective lens 2 with a meniscus structure, in sequence from an object side to an image side;

5: a third lens 8 for splitting 5 light;

the first rear lens group is composed of a fourth lens 12 of a meniscus structure, a fifth lens 14 of a biconcave structure, a sixth lens 16 of a biconvex structure and a seventh lens 19 of a biconvex structure in sequence, and the first rear lens group has a first image surface;

and the rear lens group II is composed of an eighth lens 25 with a biconvex structure, a ninth lens 27 with a biconcave structure, a tenth lens 29 with a biconvex structure and an eleventh lens 32 with a meniscus structure in sequence, and the rear lens group II is provided with a second image surface.

The double-telecentric lens with double multiplying power further comprises an objective lens barrel I1, an objective lens pressing ring I5 and an objective lens pressing ring II 3, wherein the objective lens barrel I1 is fixedly connected with the first objective lens 4 through the objective lens pressing ring I5, and the second objective lens 2 is fixedly connected with the objective lens barrel I1 through the objective lens pressing ring II 3.

The double-telecentric lens with double magnification further comprises an objective lens barrel II 6 and a beam splitter base 9, one end of the objective lens barrel II 6 is fixedly connected with the objective lens barrel I1, and the other end of the objective lens barrel II 6 is in screw connection with the beam splitter base 9.

The double-telecentric lens with double multiplying powers further comprises a first rear lens barrel 10 and a second rear lens barrel 23, one end of the beam splitter base 9 along the optical axis is in threaded connection with the first rear lens barrel 10, and one end of the beam splitter base 9 perpendicular to the optical axis is in threaded connection with the second rear lens barrel 23.

The double-telecentric lens with double multiplying powers further comprises a semi-transparent and semi-reflective seat 7, the semi-transparent and semi-reflective seat 7 is arranged in the spectroscope seat 9, and the third lens 8 is arranged on the semi-transparent and semi-reflective seat 7 and is arranged in the spectroscope seat 9 at an angle of 45 degrees with the optical axis.

The fourth lens 12, the fifth lens 14, the sixth lens 16, and the seventh lens 19 are sequentially mounted in the rear lens barrel one 10;

the eighth lens 25, the ninth lens 27, the tenth lens 29, and the eleventh lens 32 are mounted in the rear lens barrel two 23 in this order.

A spacer first 13 is disposed between the fourth lens 12 and the fifth lens 14, and a spacer second 15 is disposed between the fifth lens 14 and the sixth lens 16.

The double-magnification double-telecentric lens further comprises a first pressing ring 17, a second pressing ring 20, a first lens seat 11 and a second lens seat 18, wherein the first lens seat 11 and the second lens seat 18 are arranged in the first rear lens barrel 10, the fourth lens 12, the fifth lens 14 and the sixth lens 16 are arranged in the first lens seat 11 and fixed through the first pressing ring 17, and the seventh lens 19 is arranged in the second lens seat 18 and fixed through the second pressing ring 20.

A third spacer 26 is disposed between the eighth lens 25 and the ninth lens 27, and a fourth spacer 28 is disposed between the ninth lens 27 and the tenth lens 29.

The double-magnification double-telecentric lens further comprises a pressing ring three 30, a lens holder three 24 and a lens holder four 31, the lens holder three 24 and the lens holder four 31 are all arranged in the rear lens barrel two 23, the eighth lens 25, the ninth lens 27 and the tenth lens 29 are placed in the lens holder three 24 and fixed through the pressing ring three 30, and the eleventh lens 32 is placed in the lens holder four 31 and fixed through the pressing ring three 30.

The distance between the first objective lens 4 and the object plane is 100mm, the air interval between the second objective lens 2 and the first objective lens 4 is 43mm, the third lens 8 is placed at an angle of 45 degrees with respect to the optical axis, the air interval between the center of the third lens 8 and the second objective lens 2 is 105mm, the air interval between the fourth lens 12 and the third lens 8 in the light transmission direction is 15mm, the air interval between the fifth lens 14 and the fourth lens 12 is 6mm, the air interval between the sixth lens 16 and the fifth lens 14 is 1.4mm, the air interval between the seventh lens 19 and the sixth lens 16 is 17mm, and the air interval between the first image plane and the seventh lens 19 is 20 mm;

in the reflection direction of light, the rear lens group two forms 90 ° with the optical axis of the objective lens group, the air interval between the eighth lens 25 and the third lens 8 is 15mm, the air interval between the ninth lens 27 and the eighth lens 25 is 9.5mm, the air interval between the tenth lens 29 and the ninth lens 27 is 5mm, the air interval between the eleventh lens 32 and the tenth lens 29 is 22mm, the air interval between the second image plane and the eleventh lens 32 is 20mm, and diaphragms are disposed on the fourth lens 12 and the eighth lens 25.

Extinction threads are arranged inside the object lens barrel I1 and the object lens barrel II 6.

The rear end of the second rear lens barrel 23 is provided with a focusing ring 21 and a standard C joint 22.

In this embodiment, a double-magnification telecentric lens includes an optical lens, from an object side to an image side, a first objective lens 4 with a double convex structure, a second objective lens 2 with a meniscus structure, and an objective lens group consisting of the first objective lens 4 and the second objective lens 2; 5: the optical lens system comprises a 5-beam-splitting third lens 8, a lens with a large visual field and low magnification along the optical axis direction, a fourth lens 12 with a meniscus structure, a fifth lens 14 with a biconcave structure, a sixth lens 16 with a biconvex structure and a seventh lens 19 with a biconvex structure which form a first rear lens group, wherein a first image plane is I1; the lens with small visual field and high magnification is formed by 90-degree directions of light rays and an optical axis, and sequentially comprises an eighth lens 25 with a double convex structure, a ninth lens 27 with a double concave structure, a tenth lens 29 with a double convex structure and an eleventh lens 32 with a meniscus structure to form a second rear lens group, wherein the second image plane is I2.

The distance from the first objective lens 4 to the object plane is 100mm, the air interval from the second objective lens 2 to the first objective lens 4 is 43mm, the third lens 8 is placed at 45 degrees to the optical axis, the air interval from the center of the third lens 8 to the second objective lens 2 is 105mm, the air interval from the fourth lens 12 to the third lens 8 in the light transmission direction is 15mm, the air interval from the fifth lens 14 to the fourth lens 12 is 6mm, the air interval from the sixth lens 16 to the fifth lens 14 is 1.4mm, the air interval from the seventh lens 19 to the sixth lens 16 is 17mm, and the air interval from the first image plane to the seventh lens 19 is 20 mm; in the reflection direction of light, the second rear lens group is arranged at 90 degrees to the optical axis of the objective lens group, the air interval between the eighth lens 25 and the third lens 8 is 15mm, the air interval between the ninth lens 27 and the eighth lens 25 is 9.5mm, the air interval between the tenth lens 29 and the ninth lens 27 is 5mm, the air interval between the eleventh lens 32 and the tenth lens 29 is 22mm, and the air interval between the second image plane and the eleventh lens 32 is 20 mm. The two diaphragms are respectively arranged on the fourth lens 12 and the eighth lens 25, namely an object focal plane of the objective lens group and image focal planes of the first rear lens group and the second rear lens group.

The first objective lens 4 and the second objective lens 2 are arranged on the objective lens barrel I1 and are fixed by an objective lens clamping ring I5 and an objective lens clamping ring II 3 respectively; the second objective lens barrel 6 is a connecting device, one end of the second objective lens barrel is connected with the first objective lens barrel 1 through threads, and the other end of the second objective lens barrel is fixed with the spectroscope base 9 through four screws; extinction threads are arranged inside the objective lens barrel I1 and the objective lens barrel II 6; the third lens 8 is placed on the semi-transparent semi-reflecting seat 7 and placed in the spectroscope seat 9 at an angle of 45 degrees with the optical axis, one end of the spectroscope seat 9 along the optical axis is connected with the first rear lens barrel 10 through threads, one end perpendicular to the optical axis is connected with the second rear lens barrel 23 through threads, and the fourth lens 12, the fifth lens 14, the sixth lens 16 and the seventh lens 19 are sequentially installed in the first rear lens barrel 10; the eighth lens 25, the ninth lens 27, the tenth lens 29, and the eleventh lens 32 are mounted in this order in the rear barrel two 23.

A first spacer 13 is arranged between the fourth lens 12 and the fifth lens 14, a second spacer 15 is arranged between the fifth lens 14 and the sixth lens 16, and the fourth lens 12, the fifth lens 14 and the sixth lens 16 are arranged in the first lens seat 11 and fixed by a first pressing ring 17; the seventh lens 19 is placed in the second lens seat 18 and fixed by the second pressing ring 20, the first lens seat 11 and the second lens seat 18 are installed in the first rear lens barrel 10 by threads, and the tail part of the first rear lens barrel 10 is connected with the focusing ring 21 and the standard C-joint 22.

A third spacer 26 is arranged between the eighth lens 25 and the ninth lens 27, a fourth spacer 28 is arranged between the ninth lens 27 and the tenth lens 29, and the eighth lens 25, the ninth lens 27 and the tenth lens 29 are arranged in the lens holder third 24 and fixed by a third pressing ring 30; the eleventh lens 32 is placed in the lens holder four 31 and fixed by the pressing ring three 30, the lens holder three 24 and the lens holder four 31 are installed in the rear lens barrel two 23 by screw threads, and the rear lens barrel tail is connected with the focusing ring 21 and the standard C-joint 22.

The above lens parameters are shown in the following table:

lens numbering	Left radius/right radius (mm)	Thickness (mm)	Nd	Vd
					First objective/biconvex	233/-1500	18	1.62032	60.34
Second objective/meniscus type	91/141	19	1.62032	60.34
					Third lens/half-transmitting half-reflecting	infinity	1	1.51680	64.2
Fourth lens/meniscus type	7.1/4.2	3	1.80491	25.46
					Fifth lens/biconcave type	-39/22.5	1.5	1.76158	26.61
Sixth lens/biconvex type	54.2/-9	3.5	1.62032	60.34
					Seventh lens/biconvex type	30.5/-80.5	2.5	1.61300	60.58
Eighth lens/biconvex lens	18/-255	4	1.62032	60.34
					Ninth lens/biconcave type	-12.5/12.5	1.5	1.75496	27.53
Tenth lens/biconvex type	113/-11.5	5	1.58904	61.25
					Eleventh lens/meniscus type	25/63	5	1.72803	28.32

The technical indexes that the lens can realize are as follows:

multiplying power of one

1. Object distance: 100mm

2. Image distance: 20mm

3. Object space view field: phi 100mm

4. Magnification: 0.11X

5. Image plane size: 2/3"

6. Effective pore diameter: f6

7. Optical distortion: < 0.05%

8. 100lp/mm:>0.5

9. Working temperature: 0-80 DEG C

10. Depth of field: 10mm

Multiplying power of two

1. Object distance: 100mm

2. Image distance of 20mm

3. Object space view field: phi 25mm

4. Magnification: 0.24X

5. Image plane size: 1/3"

6. Effective pore diameter: f6

7. Optical distortion: < 0.03%

8. 100lp/mm:>0.5

7. Working temperature: 0-80 DEG C

8. Depth of field: 6 mm.

Because the double-magnification telecentric lens on the market at present generally shares an objective lens group, the double-magnification telecentric lens passes through a spectroscope and then divides a light path into 2 parts, and the double-magnification telecentric lens passes through 2 rear lens groups respectively to achieve the purpose of double-magnification, wherein the magnification is generally below 0.5 times, and generally a low-magnification large-view-field lens and a high-magnification small-view-field lens are combined. In order to satisfy the resolution of 2 groups of lenses, the number of lenses used in a common objective lens group is generally more, and is between 3 and 5 lenses; the increase of the number of objective lenses can not only reduce the transmittance of light and increase the design difficulty, but also improve the tolerance sensitivity, and the volume of the lens is correspondingly larger, so that the cost of the lens can be increased and the assembly difficulty is increased; the lens usually works at a relatively stable temperature, and the temperature difference change has a large influence on the imaging result.

The double-telecentric lens with double multiplying power can effectively solve the problems of more used objective lenses, high tolerance sensitivity, high assembly difficulty, high manufacturing cost and overlarge lens volume, and simultaneously, only one lens is used for simultaneously observing two visual fields, so that the problem that the traditional lens cannot flexibly switch different visual fields is solved; in addition, the magnification ratio is not changed and the distortion is small within a certain working range, the magnification ratio is controlled within 0.05 percent, the measurement precision is high, and the 100lp/mm is more than 0.5. Meanwhile, the problem that the telecentric lens is easily influenced by temperature change is solved, and high imaging precision and low distortion rate can be kept within the temperature of 0-100 ℃. The double-telecentric lens with double multiplying power has more reasonable structural design and better use effect.

While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.