CN-121978818-A - Small-sized tele lens for portable code scanning equipment and working method thereof

CN121978818ACN 121978818 ACN121978818 ACN 121978818ACN-121978818-A

Abstract

The invention relates to a small-sized long-focus lens for portable code scanning equipment and a working method thereof, wherein the lens consists of a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens which are sequentially arranged along the incidence direction of light, a diaphragm is arranged between the third lens and the fourth lens, the second lens and the third lens are glued to form a glued lens group A, the fourth lens and the fifth lens are glued to form a glued lens group B, the invention adopts the design of 6 glass spherical lenses, and the parameters and the on-axis distance of each lens are optimized to ensure that the lens meets the optical performance of high resolution and long focal length, meanwhile, the lens has the advantages of low distortion and high illumination, the total length of the lens is smaller, and the miniaturization requirement of the portable code scanning equipment is met.

Inventors

HOU JIAXIN
LIU GUANLU
JIANG WEI
JIANG QIN
HE WENBO
HUANG DENGHUI

Assignees

福建福光天瞳光学有限公司

Dates

Publication Date: 20260505
Application Date: 20251231

Claims (10)

1. A small-sized tele lens for a portable code scanning device is characterized by comprising a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens which are sequentially arranged along the incidence direction of light rays, wherein a diaphragm is arranged between the third lens and the fourth lens.
2. The small-sized tele lens according to claim 1, wherein the second lens and the third lens are combined into a cemented lens group A, and the fourth lens and the fifth lens are combined into a cemented lens group B.
3. The small-sized tele lens according to claim 1, wherein the first lens is a meniscus lens with positive focal power, the object side surface of the first lens is a convex surface, the image side surface of the first lens is a concave surface, the second lens is a biconvex lens with positive focal power, the object side surface of the second lens is a convex surface, the image side surface of the second lens is a convex surface, the third lens is a biconvex lens with negative focal power, the object side surface of the third lens is a concave surface, the image side surface of the third lens is a concave surface, the fourth lens is a biconvex lens with positive focal power, the object side surface of the fourth lens is a convex surface, the image side surface of the fourth lens is a convex surface, the fifth lens is a biconcave lens with negative focal power, the object side surface of the fifth lens is a concave surface, the image side surface of the sixth lens is a concave surface of the fourth lens with positive focal power, and the object side surface of the sixth lens is a convex surface.
4. The small-sized tele lens of claim 1, wherein the first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens are glass spherical lenses.
5. The small-sized tele lens as set forth in claim 1, wherein the focal length of the lens is f, the focal lengths of the first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens are f 1 、f 2 、f 3 、f 4 、f 5 、f 6 , respectively, and f 1 、f 2 、f 3 、f 4 、f 5 、f 6 and f satisfy the following ratio ：0<f 1 /f<0.5,0<f 2 /f<0.5,-0.5<f 3 /f<0,0<f 4 /f<0.5,-0.5<f 5 /f<0,0<f 6 /f<0.5.
6. The small-sized tele lens according to claim 1, wherein the first lens satisfies a relation of 1.5N d ≤1.8,V d to 50, the second lens satisfies a relation of 1.4N d ≤1.6,V d to 50, the third lens satisfies a relation of 1.8N d ≤2.0,V d to 50, the fourth lens satisfies a relation of 1.5N d ≤1.8,V d to 50, the fifth lens satisfies a relation of 1.8N d ≤2.0,V d to 50, the sixth lens satisfies a relation of 1.8N d ≤2.0,V d to 50, wherein N d is refractive index and V d is Abbe's number.
7. The small-sized tele lens of claim 1, wherein the air space between the first lens and the second lens is 0-0.2 mm, the air space between the third lens and the fourth lens is 1.0-1.5 mm, and the air space between the fifth lens and the sixth lens is 3.0-3.5 mm.
8. The small-sized tele lens of claim 1, wherein the total optical length TTL of the lens and the focal length f of the lens satisfy TTL/f less than or equal to 1.0.
9. The small-sized tele lens according to claim 1, wherein H/f is more than or equal to 0.3, and the focal length f of the lens is equal to H.
10. The working method of the small-sized tele lens for the portable code scanning equipment is characterized in that when light is incident, the light path sequentially enters a first lens, a second lens, a third lens, a diaphragm, a fourth lens, a fifth lens and a sixth lens, and finally imaging is carried out on an image plane.

Description

Small-sized tele lens for portable code scanning equipment and working method thereof Technical Field The invention relates to a small-sized tele lens for portable code scanning equipment and a working method thereof. Background With the automation and the chemical development of retail, logistics and warehouse industries, bar code scanning equipment has become an indispensable tool. Conventional code scanning guns typically employ a short-focus or standard focus segment lens with a short optimum working distance (typically between a few centimeters and tens of centimeters). However, in automated stereoscopic warehouses, large conveyor sorting systems, and in applications where a safe distance (e.g., a hazardous materials warehouse) needs to be maintained, there is an urgent need for code scanning devices that can quickly and accurately read barcodes over longer distances. Long-focus lens is usually needed for realizing long-distance code scanning, and the long-focus lens can provide a narrow field of view, so that limited pixel resources are concentrated on a remote bar code target, and the recognition capability is improved. However, applying a tele lens in a portable or handheld code-scanning robber faces serious miniaturization challenges. The traditional long-focus lens has long optical total length, is unfavorable for long-time handheld operation, and is difficult to integrate into embedded equipment with strict limitation on space. In the prior art, some remote code scanning schemes are modified by adopting universal photographic lenses, but the lenses are not specially optimized for code scanning application, and the problems that firstly, the lenses are usually designed for a large image sensor, so that the diameter of the lenses is overlarge, secondly, the optical design is focused on the visual impression of photography, certain distortion and aberration exist, the accuracy of bar code identification is affected, and thirdly, the cost and the volume are difficult to control. Thus, there is a strong need in the art for a tele lens that is optimized for code scanning applications. The lens needs to ensure that the optical system is extremely miniaturized (for example, TTL is smaller than 20 mm) under the premise of enough working distance and depth of field range, and strictly controls optical distortion and field curvature, so that a bar code image with high contrast and low geometric deformation can be provided for a decoding algorithm on the whole image surface. Disclosure of Invention In view of the defects of the prior art, the invention provides a small-sized long-focus lens for portable code scanning equipment and a working method thereof, and the design of 6 glass lenses is adopted, so that the small-sized long-focus lens has the advantages of miniaturization, high illumination, high image quality, good thermal stability and the like on the premise of meeting the specific working distance and depth of field range. The technical problem is solved by adopting the scheme that the small-sized tele lens for the portable code scanning equipment comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens which are sequentially arranged along the incidence direction of light rays, and a diaphragm is arranged between the third lens and the fourth lens. Further, the second lens and the third lens are glued to form a glued lens group A, and the fourth lens and the fifth lens are glued to form a glued lens group B. The first lens is a meniscus lens with positive focal power, the object side surface of the first lens is a convex surface, the image side surface of the first lens is a concave surface, the second lens is a biconvex lens with positive focal power, the object side surface of the second lens is a convex surface, the image side surface of the second lens is a convex surface, the third lens is a biconcave lens with negative focal power, the object side surface of the third lens is a concave surface, the image side surface of the third lens is a concave surface, the fourth lens is a biconvex lens with positive focal power, the object side surface of the fourth lens is a convex surface, the image side surface of the fourth lens is a convex surface, the fifth lens is a biconcave lens with negative focal power, the object side surface of the fifth lens is a concave surface, the image side surface of the sixth lens is a meniscus lens with positive focal power, and the object side surface of the sixth lens is a concave surface. Further, the first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens are all glass spherical lenses. Further, the focal length of the lens is f, and the focal lengths of the first lens, the second lens, the third lens, the fourth lens, the fifth lens and the sixth lens are respectively f 1、f2、f3、f4、f5、f6, wherein f 1、f2、f3、f4、f5、f6 and f satisfy the following ratio ：0<f1/f<0.5,0<f2/f<0.5,-0.5<f3/f<0,