CN102998761B - Camera lens module - Google Patents

Abstract

A lens module, comprising a first spacer ring, a first lens, a second spacer ring, a second lens and a third lens arranged from the object side to the image side, the first spacer ring is located between the first lens and the Between the second lens, the second spacer ring is located between the second lens and the third lens, and the inner hole diameter B of the second spacer ring is smaller than the effective aperture C of the third lens and larger than the The effective aperture A of the second lens.

Description

Lens module

technical field

The invention relates to a lens module.

Background technique

Because the traditional lens module only considers the relative illuminance (Relative Uniformity, RU) specifications, in order to improve the relative illuminance of the lens module, in the optical design stage, the relative illuminance curve is designed to be relatively gentle at the 1.0-1.2 field of view.

However, the above design will reverse the relative illuminance curve due to manufacturing errors, and this relative illuminance reversal phenomenon will cause RU failure in the optical quality test, such as the warping phenomenon at a in Figure 1.

Contents of the invention

In view of this, it is necessary to provide a lens module with a gentle relative illuminance curve.

A lens module, comprising a first spacer ring, a first lens, a second spacer ring, a second lens and a third lens arranged from the object side to the image side, the first spacer ring is located between the first lens and the Between the second lens, the second spacer ring is located between the second lens and the third lens, and the inner hole diameter B of the second spacer ring is smaller than the effective aperture C of the third lens and larger than the The effective aperture A of the second lens. C, B, and A satisfy the relation: $0.098\≤\frac{C-B}{C}\≤0.128$ and $0.259\≤\frac{B-A}{A}\≤\mathrm{0.301.}$

Compared with the prior art, the diameter of the inner hole of the second spacer ring of the lens module of the embodiment of the present invention is larger than the effective aperture of the second lens and smaller than the effective aperture of the third lens, through the first lens, the second lens and the third lens. The brightness around the light of the lens is low, so that the brightness around the imaging is low, so that the relative illuminance curve declines smoothly without warping.

Description of drawings

FIG. 1 is a schematic diagram of the relative illuminance of a conventional lens module.

FIG. 2 is a schematic diagram of a lens module according to an embodiment of the present invention.

FIG. 3 is a schematic diagram of the relative illuminance of the lens module according to the embodiment of the present invention.

Description of main component symbols

Lens module 10

lens barrel 11

first lens 12

first spacer ring 13

Second lens 14

Second spacer ring 15

third lens 16

Infrared cut filter 17

Image sensor 18

mirror mount 19

The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings.

detailed description

2 and 3, the lens module 10 provided by the embodiment of the present invention includes a lens barrel 11, a first lens 12, a first spacer ring 13, a second lens 14, a second spacer ring 15, a third lens 16, Infrared cut filter 17 , image sensor 18 and mirror holder 19 . The lens barrel 11 and the lens holder 19 are screwed together so that the lens barrel 11 can move up and down in the lens holder 19 to change the distance between the red image sensor 18 and the lens barrel 11 .

The light is imaged on the image sensor 18 through the first lens 12 , the second lens 14 , the third lens 16 and the infrared cut filter 17 .

The first lens 12 , the first spacer ring 13 , the second lens 14 , the second spacer ring 15 , the third lens 16 , and the infrared cutoff filter 17 are arranged in the lens barrel 11 sequentially from the object side to the image side.

The first spacer ring 13 is located between the first lens 12 and the second lens 14 to separate the first lens 12 and the second lens 14. In addition, the first spacer ring 13 is used to control the amount of light passing through the lens module 10, with Aperture (aperture) function.

The second spacer ring 15 is located between the second lens 14 and the third lens 16 for spacing the second lens 14 and the third lens 16 , and the infrared cut filter 17 abuts against the side of the third lens 16 close to the image side.

The effective aperture of the second eyeglass 14 (effective aperture, the diameter of the light beam that can pass through the eyeglass) is denoted as A, the inner hole diameter of the second spacer ring 15 is denoted as B, and the effective aperture of the 3rd eyeglass 16 is denoted as C, wherein, A The values of , B, and C have the following relationship: C>B>A.

For example, where C is 0.876 mm and A is 0.607 mm, B may be 0.78 mm, 0.774 mm, or 0.764 mm.

Under the condition of C>B>A, C, B, A also have the following relationship: $0.259\≤\frac{B-A}{A}\≤\mathrm{0.301.}$

Because the inner hole diameter of the second spacer ring 15 is greater than the effective aperture of the second eyeglass 14 and less than the effective aperture of the third eyeglass 16, then the light rays projected by the first eyeglass 12, the second eyeglass 14 and the third eyeglass 16 are in The brightness around the light of the image sensor 18 is low, so that the brightness around the imaging is low, so that the relative illuminance curve declines gently, without warping phenomenon, point b in FIG. 3 .

It can be understood that those skilled in the art can also make other changes within the spirit of the present invention to be used in the design of the present invention, as long as they do not deviate from the technical effects of the present invention. These changes made according to the spirit of the present invention should be included in the scope of protection of the present invention.

Claims (6)

1. A lens module, comprising a first spacer ring, a first eyeglass, a second spacer ring, a second eyeglass and a third eyeglass arranged from the object side to the image side, the first spacer ring is located at the first Between the lens and the second lens, the second spacer ring is located between the second lens and the third lens, characterized in that the diameter B of the inner hole of the second spacer ring is smaller than the effective diameter of the third lens Aperture C and greater than the effective aperture A of the second lens, C, B, A satisfy the relationship and $0.259\≤\frac{B-A}{A}\≤\mathrm{0.301.}$ 2. The lens module according to claim 1, wherein the effective aperture of the second lens is 0.607 mm, the effective aperture of the third lens is 0.876 mm, and the diameter of the inner hole of the second spacer ring is 0.607 mm. 0.78mm, 0.774mm or 0.764mm. 3. The lens module according to claim 1, wherein the lens module further comprises an infrared cut-off filter, and the infrared cut-off filter abuts against an end of the third lens near the image side . 4. The lens module according to any one of claims 1 to 3, wherein the lens module further comprises a lens barrel, the first spacer ring, the first lens, the second spacer ring, the first The second lens and the third lens are located in the lens barrel. 5. The lens module according to claim 4, wherein the lens module further comprises a lens holder, and the lens barrel is accommodated in the lens holder. 6 . The lens module according to claim 5 , wherein the lens barrel is matched with the lens base through a thread.