CN211426884U

CN211426884U - Short-working-distance telecentric lens

Info

Publication number: CN211426884U
Application number: CN202020344657.0U
Authority: CN
Inventors: 洪小苗
Original assignee: Suzhou Aixian Photoelectric Technology Co ltd
Current assignee: Suzhou Aixian Photoelectric Technology Co ltd
Priority date: 2020-03-18
Filing date: 2020-03-18
Publication date: 2020-09-04
Anticipated expiration: 2030-03-18

Abstract

The utility model discloses a short working distance telecentric lens, including preceding group lens cone and back group lens cone, preceding group lens cone and back group lens cone fixed connection, the inner chamber front end of preceding group lens cone is equipped with first lens, and the inner chamber middle part of preceding group lens cone is equipped with second lens group, and the inner chamber front end of back group lens cone is equipped with the third lens, and the inner chamber middle part of back group lens cone is equipped with the fourth lens, is equipped with the diaphragm between second lens group and the third lens. The utility model discloses a working distance is less than 40mm, and is more than 1/3 than the working distance of the common low magnification telecentric lens on the market is little at present, at certain application, can shorten workspace, makes the structure compacter, and the use is more convenient.

Description

Short-working-distance telecentric lens

Technical Field

The utility model relates to an optics inspection measures technical field, specifically is a short working distance telecentric lens.

Background

The telecentric lens is mainly designed for correcting the parallax of the traditional industrial lens, the magnification of the obtained image can not be changed within a certain object distance range, which is very important for the condition that the measured object is not on the same object plane, and the telecentric lens is always favored for the machine vision application occasion with high requirement on lens distortion due to the special parallel light path design. At present, the working distance of the low-magnification telecentric lens on the market is mostly 65mm or more, and for some special application occasions, the working distance of the lens is required to be short, so that the space can be shortened. Therefore, we propose a short-working-distance telecentric lens.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a short working distance telecentric lens to solve the problem that proposes among the above-mentioned background art.

In order to achieve the above object, the utility model provides a following technical scheme: the utility model provides a short working distance telecentric lens, includes preceding group's lens cone and back group's lens cone, preceding group's lens cone and back group's lens cone fixed connection, the inner chamber front end of preceding group's lens cone is equipped with first lens, the inner chamber middle part of preceding group's lens cone is equipped with second lens group, the inner chamber front end of back group's lens cone is equipped with the third lens, the inner chamber middle part of back group's lens cone is equipped with the fourth lens, be equipped with the diaphragm between second lens group and the third lens.

Preferably, the front lens barrel group and the rear lens barrel group are connected through coaxial fine threads.

Preferably, the second lens group is formed by gluing a biconvex lens and a biconcave lens.

Preferably, the front end of the first lens is provided with a front group pressing ring, the front end of the second lens group is provided with a front group spacing ring, the rear end of the fourth lens is provided with a rear group pressing ring, and the rear end of the third lens is provided with a rear group spacing ring.

Preferably, the rear end of the rear group lens barrel is fixedly assembled with a C-interface connector through a stop screw.

Compared with the prior art, the beneficial effects of the utility model are that: the working distance of the short-working-distance telecentric lens is less than 40mm, and is smaller than that of a common low-magnification telecentric lens on the market at present by more than 1/3, so that the working space can be shortened in certain application occasions, the structure is more compact, and the use process is more convenient.

Drawings

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

Fig. 2 is an imaging schematic diagram of the present invention.

Fig. 3 is a light path diagram of the present invention.

In the figure: 1. the lens comprises a first lens, a second lens group, a third lens, a fourth lens, a front lens barrel, a front lens spacer, a front lens pressing ring, a rear lens barrel, a rear lens spacer, a rear lens pressing ring, a first lens, a second lens, a third lens, a fourth lens barrel, a fourth lens spacer, a fourth lens barrel, a fourth lens.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

Referring to fig. 1, fig. 2 and fig. 3, the present invention provides a technical solution: a short-working-distance telecentric lens comprises a front lens barrel 5 and a rear lens barrel 8, wherein the front lens barrel 5 and the rear lens barrel 8 are connected through coaxial fine threads, the rear end of the rear lens barrel 8 is fixedly provided with a C interface connecting piece 12 through a stop screw, the front end of the inner cavity of the front lens barrel 5 is provided with a first lens 1, the middle part of the inner cavity of the front lens barrel 5 is provided with a second lens group 2, the front end of the inner cavity of the rear lens barrel 8 is provided with a third lens 3, the middle part of the inner cavity of the rear lens barrel 8 is provided with a fourth lens 4, the second lens group 2 is formed by bonding a biconvex lens and a biconcave lens, the biconvex lens is positioned at the front side, the curvature radiuses of all lenses in the first lens 1, the second lens group 2, the third lens 3 and the fourth lens 4 are respectively 26.5mm, -41.9mm, -13.5mm, 12.8mm, -30mm, 10mm, -21.44mm, 10.63mm, the thickness of each lens in the first lens 1, the second lens group 2, the third lens 3, the fourth lens 4 is 3mm, 4.2mm, 1.55mm, 1.99mm, 2.03mm in proper order, the refractive index of each lens in the first lens 1, the second lens group 2, the third lens 3, the fourth lens 4 is 1.6, 1.57, 1.73, 1.6, 1.64 in proper order, thereby make the utility model discloses a working distance is less than 40mm, is equipped with diaphragm 11 between second lens group 2 and the third lens 3.

The front end of first lens 1 is equipped with preceding group clamping ring 7, first lens 1 is through preceding group clamping ring 7 pressure equipment in preceding group lens cone 5, the front end of second lens group 2 is equipped with preceding group space ring 6, guarantee through setting up preceding group space ring 6 with the air interval between first lens 1, the rear end of fourth lens 4 is equipped with back group clamping ring 10, fourth lens 4 is through back group clamping ring 10 pressure equipment in back group lens cone 5, the rear end of third lens 3 is equipped with back group space ring 9, guarantee through setting up back group space ring 9 with the air interval between fourth lens 4.

It is obvious to a person skilled in the art that the invention is not restricted to details of the above-described exemplary embodiments, but that it can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.

Claims

1. The utility model provides a short working distance telecentric lens which characterized in that: the lens barrel assembly comprises a front lens barrel (5) and a rear lens barrel (8), wherein the front lens barrel (5) and the rear lens barrel (8) are fixedly connected, a first lens (1) is arranged at the front end of an inner cavity of the front lens barrel (5), a second lens group (2) is arranged in the middle of the inner cavity of the front lens barrel (5), a third lens (3) is arranged at the front end of the inner cavity of the rear lens barrel (8), a fourth lens (4) is arranged in the middle of the inner cavity of the rear lens barrel (8), and a diaphragm (11) is arranged between the second lens group (2) and the third lens (3).

2. A short-throw telecentric lens according to claim 1, wherein: the front group lens cone (5) and the rear group lens cone (8) are connected through coaxial fine threads.

3. A short-throw telecentric lens according to claim 1, wherein: the second lens group (2) is formed by gluing a biconvex lens and a biconcave lens.

4. A short-throw telecentric lens according to claim 1, wherein: the front end of the first lens (1) is provided with a front group pressing ring (7), the front end of the second lens group (2) is provided with a front group spacing ring (6), the rear end of the fourth lens (4) is provided with a rear group pressing ring (10), and the rear end of the third lens (3) is provided with a rear group spacing ring (9).

5. A short-throw telecentric lens according to claim 1, wherein: the rear end of the rear group lens barrel (8) is fixedly provided with a C-interface connecting piece (12) through a stop screw.