CN218782466U

CN218782466U - Low-light-level night vision objective lens optical system for vehicle driver

Info

Publication number: CN218782466U
Application number: CN202223475348.5U
Authority: CN
Inventors: 韩鹏飞; 王振华; 凌晗; 张鹏; 马红艳; 吴秋丽
Original assignee: Beijing Beifang Changcheng Photoelectric Instrument Co ltd
Current assignee: Beijing Beifang Changcheng Photoelectric Instrument Co ltd
Priority date: 2022-12-26
Filing date: 2022-12-26
Publication date: 2023-03-31
Anticipated expiration: 2032-12-26

Abstract

The utility model relates to a vehicle driver's shimmer night vision objective optical system, 1 including diaphragm L3, shimmer image intensifier negative pole face protection glass L7 and lens, its characterized in that, diaphragm L3, shimmer image intensifier negative pole face protection glass L7 and lens are in same optical axis fixed arrangement, lens are the combination of five eight formula shimmer lenses of group, five eight formula shimmer lens combination layouts are first single lens L1, the two cemented lens L2 of second, third cemented lens L4, fourth single lens L5, fifth cemented lens L6 in proper order, compare with current objective, and this objective can satisfy the image quality requirement of achromatic aberration and high resolution in the shimmer objective 450nm ~ 950nm wide spectral range, can realize the man-machine efficiency index requirement of big relative aperture and big visual field again.

Description

Low-light-level night vision objective lens optical system for vehicle driver

Technical Field

The utility model discloses establish and relate to shimmer night vision technical field, relate to a vehicle driver shimmer night vision objective optical system.

Background

The objective lens of the low-light night vision observation mirror for the vehicle driver is a night vision imaging system which takes a low-light image intensifier as a core device, and utilizes the night light of natural world such as weak moonlight, starlight, atmospheric glow, galaxy light and the like at night as illumination, and the low-light image intensifier is used for amplifying the weak photons reflected by the target and converting the weak photons into an image which can be clearly observed by human eyes, so that the target can be observed under the condition of low illumination.

Because the normal observation view angle of two eyes of a person is 120 degrees and is limited by weight, external dimension and resolution, the observation view field of the low-light night vision observation mirror is smaller than the normal observation view field of the eyes, so that a driver can generate certain observation blind areas when using the low-light night vision observation mirror at night, the workload is increased, and the use safety is influenced; meanwhile, the low-light night vision observation mirror for the driver converts weak light into an image which can be clearly observed by human eyes through the optical lens with large relative aperture and the high-gain low-light image intensifier at night or under extremely low illumination, the relative aperture of the objective represents the light collecting capability of the system, the large relative aperture is favorable for enhancing the working energy efficiency of the system under extremely severe conditions such as rain, fog and cloudy days, and the man-machine safety during wartime is improved.

In order to improve the man-machine efficiency of the system and improve the man-machine safety, the objective lens of the low-light night vision observation mirror is required to have large relative aperture and large field of view while ensuring good optical performance and low manufacturing cost. Because optical performance, manufacturing cost, relative aperture and visual field are two sets of indexes which are mutually contradictory, the relative aperture or the visual field of the objective lens used at present is too small, and the requirements of man-machine efficacy and performance indexes cannot be simultaneously considered.

The utility model patent with application number 201720567238.1 discloses a large relative aperture micro-optical television imaging front storage lens optical system, which has a focal length of 20mm and a field of view of 50 degrees and can only be applied to a super-second generation micro-optical image intensifier with a photosensitive area of 18 mm; the focal length of the device is 20mm, and the detection distance is not far enough; the distance between the second negative meniscus lens 9 and the image intensifier 10 is only 2mm relatively close, and the distance is difficult to meet the use requirement on an engineering product, and the lens and the image intensifier are interfered by removing the thickness of a reserved structural part and the size of error adjustment mainly because the position is the interface position of the lens and the image intensifier, and a protective glass window in front of the intensifier is damaged in the use process; meanwhile, because no adjusting space is provided, the reduction of the system definition caused by the fact that the lens is moved back and forth to compensate the high and low temperature drift of the system and the reduction of the definition during imaging on different detection distances are difficult to achieve, and the actual use requirements of products caused according to patents are difficult to meet.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to design a vehicle driver shimmer night vision objective optical system thereby solves technical problem.

The utility model discloses specific technical scheme as follows: the utility model provides a vehicle driver shimmer night vision objective optical system, includes diaphragm L3, shimmer image intensifier negative pole face protection glass L7 and lens, its characterized in that, diaphragm L3, shimmer image intensifier negative pole face protection glass L7 and lens are fixed arrangement on same optical axis, lens are the combination of five eight formula shimmer lenses of group, five eight formula shimmer lens combination layouts of group are first single lens L1, the two cemented lens L2 of second, third cemented lens L4, fourth single lens L5, fifth cemented lens L6 in proper order.

As an improvement, the first single lens L1 is a meniscus lens, the second cemented lens L2 has one surface that is a convex surface and the other surface that is a concave surface, the third cemented lens L4 has one surface that is a concave surface and the other surface that is a convex surface, the fourth single lens L5 is a biconvex lens, the fifth cemented lens L6 has one surface that is a convex surface and the other surface that is a concave surface, and the cathode surface protection glass L7 of the low-light-level image intensifier is plate glass.

As a further improvement, the first single lens L1 bends toward the image and is adjacent to the convex surface of the second cemented lens L2, the stop L3 is disposed on the concave surface of the second cemented lens L2, the concave surface of the third cemented lens L4 is adjacent to the stop, the convex surface of the third cemented lens L4 is adjacent to a convex surface of the fourth single lens L5, the other convex surface of the fourth single lens L5 is adjacent to the convex surface of the fifth cemented lens L6, and the concave surface of the fifth cemented lens L6 is adjacent to the low-light-level image intensifier cathode-side protective glass L7.

As a further improvement, the lens is a spherical glass lens.

As a further improvement, the thickness of the low-light-level image intensifier cathode surface protective glass L7 is 5.5mm.

As a further improvement, the focal length of the lens is 30mm.

As a further development, the field angle FOV of the objective is 48 °.

As a further improvement, it is characterized in that the relative aperture of the objective lens is 1/1.2.

The utility model relates to a vehicle driver shimmer night vision objective optical system, through the preparation of above-mentioned scheme, structural layout is reasonable, effectively balances the senior aberration that the wide light beam of off-axis introduced through first single positive lens L1, improves the diffusion angle of light beam; the chromatic aberration and distortion of the broad spectrum can be effectively eliminated by introducing the second double cemented lens L2 and the third cemented lens L3, and clear imaging under the broad spectrum is realized; the anomalous cemented surface introduced by the fifth double cemented lens is beneficial to the correction of high-grade negative spherical aberration and high-grade negative astigmatism on the shaft, improves the off-axis spherical aberration and realizes a large relative aperture under a large field of view; the fourth single lens L5 can effectively share the focal power of the system, balance spherical aberration, coma aberration and curvature of field in the front system, and mutually match various materials on each surface of the lens in the system to restrict various aberrations in the balance system, thereby well optimizing the whole image quality. The utility model adopts spherical glass lens under the condition of ensuring good image quality, and has simple structure and easy processing; compared with the existing objective lens, the objective lens can meet the requirements of achromatic aberration and high resolution image quality in a wide spectral range of 450-950 nm of the low-light-level night vision objective lens, and can meet the requirements of human-computer efficacy indexes of large relative aperture and large visual field.

Drawings

Fig. 1 is a schematic view of the overall structure of a low-light night vision objective optical system for a vehicle driver according to the present invention;

fig. 2 is a schematic diagram of an optical path structure of a low-light night vision objective optical system for a vehicle driver according to the present invention;

fig. 3 is a schematic diagram of the transfer function curve of the on-axis and 3/4 view field of the objective optical system of the low-light-level night vision objective optical system for the vehicle driver.

Detailed Description

The following describes embodiments of the present invention in detail with reference to the accompanying drawings and examples.

Referring to fig. 1, a low-light night vision objective optical system for a vehicle driver includes a diaphragm L3, a low-light image intensifier cathode surface protection glass L7 and a lens, wherein the lens is a spherical glass lens, the focal length of the lens is 30mm, the lens is a combination of five groups of eight low-light lenses, and the combination layout of the five groups of eight low-light lenses is sequentially a first single lens L1, a second double cemented lens L2, a third cemented lens L4, a fourth single lens L5, and a fifth cemented lens L6. The diaphragm L3, the low-light-level image intensifier cathode surface protective glass L7 and the lens are fixedly arranged on the same optical axis. First single lens L1 is convex concave type meniscus lens, and second cemented lens L2 one side is the concave surface in addition for the convex surface, and third cemented lens L4 one side is the convex surface in addition for the concave surface, and fourth single lens L5 is biconvex lens, and fifth cemented lens L6 one side is the concave surface in addition for the convex surface, and shimmer image intensifier negative pole face protection glass L7 is the sheet glass that thickness is 5.5mm. The first single lens L1 bends to the image space and is adjacent to the convex surface of the second cemented lens L2, the diaphragm L3 is arranged on the concave surface of the second cemented lens L2, the concave surface of the third cemented lens L4 is adjacent to the diaphragm, the convex surface of the third cemented lens L4 is adjacent to one convex surface of the fourth single lens L5, the other convex surface of the fourth single lens L5 is adjacent to the convex surface of the fifth cemented lens L6, and the concave surface of the fifth cemented lens L6 is adjacent to the low-light image intensifier cathode surface protection glass L7.

Referring to fig. 2 and 3, the field angle FOV of the objective lens is 48 °, the relative aperture of the objective lens is 1/1.2, and the optical transfer function (MTF) of the objective lens is equal to or greater than 0.59 for 3/4 field (± 18 °) at a spatial frequency of 20lp/mm, and is equal to or greater than 0.86 on the axis.

The utility model relates to a vehicle driver shimmer night vision objective optical system, make through the above-mentioned scheme, structural layout is reasonable, effectively balances the senior aberration that wide light beam introduces outside the axle through first single positive lens L1, improves the diffusion angle of light beam; the chromatic aberration and distortion of the broad spectrum can be effectively eliminated by introducing the second double cemented lens L2 and the third cemented lens L3, and clear imaging under the broad spectrum is realized; the anomalous cemented surface introduced by the fifth double cemented lens is beneficial to the correction of high-grade negative spherical aberration and high-grade negative astigmatism on the shaft, improves the off-axis spherical aberration and realizes a large relative aperture under a large field of view; the focal power of the system can be effectively shared through the introduced fourth single lens L5, the spherical aberration, the coma aberration and the curvature of field in the front system are balanced, all surfaces of the lens in the system are matched with each other by all materials, various aberrations in the balanced system are restricted, and the whole image quality is well optimized. The utility model adopts spherical glass lens under the condition of ensuring good image quality, and has simple structure and easy processing; compared with the existing objective lens, the objective lens can meet the image quality requirements of achromatic aberration and high resolution in a 450-950 nm wide spectral range of the low-light-level night vision objective lens, and can meet the human-computer efficacy index requirements of large relative aperture and large visual field.

The above-mentioned embodiments are only preferred embodiments of the present invention, and are not intended to limit the scope of the present invention, and various modifications and improvements made by those skilled in the art without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. The utility model provides a vehicle driver low-light-level night vision objective optical system, includes diaphragm L3, low-light-level image intensifier negative pole face protection glass L7 and lens, its characterized in that, diaphragm L3, low-light-level image intensifier negative pole face protection glass L7 and lens are fixed arrangement on same optical axis, lens are the combination of five eight formula low-light-level lenses of group, five eight formula low-light-level lens of group combination layouts are first single lens L1, the two cemented lens L2 of second, third cemented lens L4, fourth single lens L5, fifth cemented lens L6 in proper order.

2. The system as claimed in claim 1, wherein the first single lens L1 is a meniscus lens, the second cemented lens L2 has a convex surface and a concave surface, the third cemented lens L4 has a concave surface and a convex surface, the fourth single lens L5 is a biconvex lens, the fifth cemented lens L6 has a convex surface and a concave surface, and the low-light image intensifier cathode surface protection glass L7 is a plate glass.

3. The vehicle driver low-light night vision objective optical system as claimed in claim 2, wherein the first single lens L1 is curved to the image side and adjacent to the convex surface of the second cemented lens L2, the stop L3 is disposed on the concave surface of the second cemented lens L2, the concave surface of the third cemented lens L4 is adjacent to the stop, the convex surface of the third cemented lens L4 is adjacent to one convex surface of the fourth single lens L5, the other convex surface of the fourth single lens L5 is adjacent to the convex surface of the fifth cemented lens L6, and the concave surface of the fifth cemented lens L6 is adjacent to the low-light image intensifier cathode surface protection glass L7.

4. A vehicle driver low-light night vision objective optical system as claimed in claim 1, wherein the lens is a spherical glass lens.

5. The vehicle driver low-light night vision objective optical system as claimed in claim 3, wherein the low-light image intensifier cathode plane protective glass L7 has a thickness of 5.5mm.

6. A vehicle driver low-light night vision objective optical system as claimed in claim 1, wherein the focal length of the lens is 30mm.

7. A vehicle driver low-light night vision objective optical system as claimed in claim 1, characterized in that the field angle FOV of the objective is 48 °.

8. A vehicle driver low-light night vision objective optical system as claimed in claim 1, wherein the relative aperture of the objective is 1/1.2.