CN218995758U

CN218995758U - Light-weight large-target-surface low-light-level objective optical lens

Info

Publication number: CN218995758U
Application number: CN202221817715.2U
Authority: CN
Inventors: 魏春刚
Original assignee: Beijing Kaiyuanxing Optoelectronics Technology Co ltd
Current assignee: Beijing Kaiyuanxing Optoelectronics Technology Co ltd
Priority date: 2022-07-14
Filing date: 2022-07-14
Publication date: 2023-05-09
Anticipated expiration: 2032-07-14

Abstract

The utility model discloses a light-weight large-target-surface micro-light objective optical lens, which comprises a first lens, a second lens, a third lens, a fourth lens and a fifth lens which are sequentially arranged from an object space to an image space; the first lens is a plano-convex positive lens, the second lens is a convex-concave positive lens, the third lens is a biconcave negative lens, the fourth lens is a convex-concave cemented positive lens, and the fifth lens is a convex-concave positive lens. The utility model provides a light-weight large-target-surface micro-light objective optical lens which has smaller volume, lighter weight, is more convenient for focusing to realize close-range observation, is convenient for being carried and held, reduces the load of a focusing mechanism and has wider application range.

Description

Light-weight large-target-surface low-light-level objective optical lens

Technical Field

The utility model relates to an optical lens, in particular to a light-weight large-target-surface low-light-level objective optical lens, and belongs to the technical field of optical systems.

Background

With the progress of chip technology, application of new photosensitive materials, back lighting and other technological processes, the imaging chip with high sensitivity obviously improves the image quality of night vision. Night vision products are widely applied, and civil use is provided with a night and day monitoring, night vehicle-mounted auxiliary driving instrument and a forest night vision camera; military use has general sight mirror around the clock, on-vehicle, airborne auxiliary pilot, border, river course, security protection control. With the further development and popularization of night vision technology, the application of the optical objective lens universal in day and night is wider and wider, and the market prospect is huge.

The existing micro-light objective optical system mainly reports that a Zhu Biao published helmet type micro-light night vision system has a focal length of 6.7mm, can only be matched with a 1/2 cmos machine core, and has quite limited observation distance. The aperture of the low-light objective lens optical system is enlarged and the weight of the lens is heavier under the same aperture condition, so that the lens is not beneficial to portable holding, and more than 2 lenses are required to move when focusing is performed at a short distance, and the load of a focusing mechanism is increased. Therefore, a light-weight large-target-surface micro-optical objective lens is needed.

Disclosure of Invention

In order to solve the defects of the technology, the utility model provides a light-weight large-target-surface micro-light objective optical lens.

In order to solve the technical problems, the utility model adopts the following technical scheme: a light-weight large-target-surface low-light-level objective optical lens comprises a first lens, a second lens, a third lens, a fourth lens and a fifth lens which are sequentially arranged from an object space to an image space;

the first lens is a plano-convex positive lens, the second lens is a convex-concave positive lens, the third lens is a biconcave negative lens, the fourth lens is a convex-concave cemented positive lens, and the fifth lens is a convex-concave positive lens.

Preferably, the ratio of the focal length of the first lens to the focal length of the entire lens satisfies the following relationship:

1.1＜|f1/f|<2；

wherein f is the focal length of the whole lens, and f1 is the focal length of the first lens.

Preferably, the third lens is a high refractive index lens having a refractive index of greater than 1.92.

Preferably, the fifth lens is a high refractive index lens having a refractive index of greater than 1.92.

Preferably, the focal length f of the whole lens is 55-90mm, and the F number is 1.2-1.4.

Preferably, the first lens is made of K9L optical glass, and the convex surface of the first lens is provided with a diaphragm.

The utility model provides a light-weight large-target-surface micro-light objective optical lens which has smaller volume, lighter weight, is more convenient for focusing to realize close-range observation, is convenient for being carried and held, reduces the load of a focusing mechanism and has wider application range.

Drawings

Fig. 1 is a structural diagram of an optical system according to an embodiment of the present utility model.

Fig. 2 is an optical distortion diagram of an embodiment of the present utility model.

Fig. 3 is an MTF resolution graph of an embodiment of the present utility model.

In the figure: 1. a diaphragm; 2. a first lens; 3. a second lens; 4. a third lens; 5. a fourth lens; 6. and a fifth lens.

Detailed Description

The utility model will be described in further detail with reference to the drawings and the detailed description.

The embodiment provides a light-weighted large-target-surface micro-light objective optical lens, the focal length f of the whole lens is 76mm, the F number is 1.4, the lens comprises a first lens 2, a second lens 3, a third lens 4, a fourth lens 5 and a fifth lens 6 which are sequentially arranged from the object space to the image space, and the specific structure is shown in figure 1.

Wherein the first lens 2 is a plano-convex positive lens, the second lens 3 is a convex-concave positive lens, the third lens 4 is a biconcave negative lens, the fourth lens 5 is a convex-concave cemented positive lens, and the fifth lens 6 is a convex-concave positive lens. Wherein the fifth lens 6 is used for focusing.

Preferably, the ratio of the focal length of the first lens 2 to the focal length of the entire lens satisfies the following relationship:

1.1＜|f1/f|<2；

wherein f is the focal length of the whole lens, and f1 is the focal length of the first lens. Preferably, f=76 mm, f1=101.9.

Preferably, the first lens 2 is made of K9L optical glass, and the diaphragm 1 is provided on the convex surface thereof.

The light-weighted large-target-surface micro-optical objective optical lens of the embodiment is provided with 5 lenses, wherein the total number of the lenses comprises eleven surfaces including a cemented lens, the lenses are numbered according to the sequence from the first lens to the fifth lens, and the curvature radius, the center thickness of the lenses, the center distance of the lenses and the refractive index of the lenses meet the following conditions:

as shown in fig. 2, the optical distortion chart of the present embodiment is shown, and the maximum distortion is only 3.6% as shown in fig. 2. As shown in fig. 3, an MTF resolution graph of the present embodiment is shown, in which the abscissa represents the spatial frequency of line pairs/mm and the ordinate represents the MTF value. As can be seen from fig. 3, the present embodiment exhibits a better contrast and a higher integrated resolution in a spatial frequency of 40 lp/mm.

In summary, the light-weight large-target-surface micro-light objective optical lens disclosed by the utility model has the following beneficial effects:

first, the diaphragm is arranged on the first surface, and the volume is minimum and the weight is light under the condition of the same focal length F number.

Second, the first lens of the utility model is made of common environment-friendly glass K9L material, and is lighter than other glass under the same size condition, and the cost is low.

Thirdly, the utility model fully exerts the characteristic of easy processing of the glass lens, adopts glass materials, and the last lens is the smallest, thus the whole system is more compact and light in weight as a focusing lens.

Fourth, the imaging target surface of the optical lens can reach 1 inch.

The above embodiments are not intended to limit the present utility model, and the present utility model is not limited to the above examples, but is also intended to be limited to the following claims.

Claims

1. The utility model provides a big target surface shimmer objective optical lens of lightweight, which characterized in that: the lens comprises a first lens (2), a second lens (3), a third lens (4), a fourth lens (5) and a fifth lens (6) which are sequentially arranged from an object side to an image side;

the first lens (2) is a plano-convex positive lens, the second lens (3) is a convex-concave positive lens, the third lens (4) is a biconcave negative lens, the fourth lens (5) is a convex-concave cemented positive lens, and the fifth lens (6) is a convex-concave positive lens.

2. The light-weight large-target-surface micro-optical objective lens according to claim 1, wherein: the ratio of the focal length of the first lens (2) to the focal length of the whole lens satisfies the following relationship:

1.1＜|f1/f|<2；

3. The lightweight large target surface micro-optic objective lens of claim 2, wherein: the third lens (4) is a high refractive index lens with a refractive index greater than 1.92.

4. A lightweight large target surface micro-optic objective optical lens as claimed in claim 3, wherein: the fifth lens (6) is a high refractive index lens having a refractive index of more than 1.92.

5. The light-weight large-target-surface micro-optical objective lens according to claim 4, wherein: the focal length f of the whole lens is 55-90mm, and the F number is 1.2-1.4.

6. The light-weight large-target-surface micro-optical objective lens according to claim 5, wherein: the first lens (2) is made of K9L optical glass, and the convex surface of the first lens is provided with a diaphragm (1).