CN103744165A

CN103744165A - Special underwater imaging wide-angle lens

Info

Publication number: CN103744165A
Application number: CN201410040571.8A
Authority: CN
Inventors: 刘西站; 何俊华; 薛艳博; 王维
Original assignee: XiAn Institute of Optics and Precision Mechanics of CAS
Current assignee: XiAn Institute of Optics and Precision Mechanics of CAS
Priority date: 2014-01-27
Filing date: 2014-01-27
Publication date: 2014-04-23
Anticipated expiration: 2034-01-27
Also published as: CN103744165B

Abstract

The invention provides a special underwater imaging wide-angle lens. The special underwater imaging wide-angle lens comprises a front negative group lens and a rear positive group lens positioned at the same optical path with the front negative group lens. Each of the front negative group lens and the rear positive group lens comprises at least four spherical mirrors positioned on the same optical path. The special underwater imaging wide-angle lens realizes the real-time monitoring and shooting of underwater shooting with a horizontal view field angel being larger than or equal to 75 degrees, a vertical view field angle being larger than or equal to 60 degrees and a diagonal view field angel being larger than or equal to 85.3 degrees.

Description

Special imaging wide-angle lens under water

Technical field

The present invention relates to optical field, relate in particular to the special wide-angle optical imaging system using in a kind of rugged surroundings under water.

Background technology

Along with the development of undersea detection technology, in the urgent need to the process of multiple target transmittings is carried out to multi-angle, large visual field, monitor, thereby understand further the motion conditions in moving target emission process, understand moving target surrounding environment change situation.

Conventionally the Underwater Imaging camera lens adopting can only be monitored in real time the moving target within the scope of small field of view or carry out low-angle shooting, applicable occasion is limited, and for the transmitting motion state of Real-Time Monitoring underwater high-speed moving target, need to possess is the special image-forming objective lens under water of a large visual field, object lens of large relative aperture.

Summary of the invention

In order to solve existing technical matters in background technology, the present invention proposes one special imaging wide-angle lens under water, realized underwater photograph technical horizontal field of view angle >=75 °, vertical field of view >=60 °, Real-Time Monitoring and the shooting of diagonal line field angle >=85.3 °.

Technical solution of the present invention is: special imaging wide-angle lens under water, comprise front negative group of lens and be positioned at the rear lens of just organizing of same light path with front negative group of lens, it is characterized in that: described front negative group of lens and the rear lens of just organizing include at least four spherical mirrors that are positioned at same light path.

Above-mentioned front negative group of lens comprise the optical window, the first negative lens, the second negative lens, the first positive lens, the 3rd negative lens that are positioned at successively same light path; The described rear lens of just organizing comprise the second positive lens, the 4th negative lens, the 3rd positive lens, the 4th positive lens, the 5th positive lens that are positioned at successively same light path.

The maximum effective aperture 130mm of above-mentioned camera lens, F number 1.6, camera lens overall length is 198mm;

Above-mentioned optical window is the concentric circles window of adopting quartz glass.

Advantage of the present invention is: the leeway that automaticity is high, focusing speed is fast, imaging good, aperture is large, camera lens group is many, select is large etc.By such topology layout, not only can realize the effective control to off-axis aberration but also can meet and under the prerequisite of little focal length, still have larger rear cut-off distance.In addition, adopted the glass of more high index of refraction, low dispersion for proofreading and correct the spherical aberration causing due to large aperture.Camera lens of the present invention has been realized underwater photograph technical horizontal field of view angle >=75 °, vertical field of view >=60 °, Real-Time Monitoring and the shooting of diagonal line field angle >=85.3 °.

Accompanying drawing explanation

Fig. 1 is principle schematic of the present invention;

Fig. 2 is structural representation of the present invention;

Fig. 3 is the optical transfer function figure of optical system of the present invention;

Fig. 4 is 5 meters of optical transfer function figure of infinite object distance;

Fig. 5 is 0.5 meter of optical transfer function figure of infinite object distance;

Embodiment

As shown in Figure 1, the present invention under water special imaging wide-angle lens has adopted the reflective structure far away of taking the photograph, this structure is comprised of front negative group of lens 1 and the rear lens 2 of just organizing, the concentric circles window that optical window 3 adopting quartz glass are material, this class window is less than the loss of plane window visual field, dependable performance, anti-pressure ability is strong.Its weak point is higher to the technological requirement of processing and assembling, and maintenance cost is higher, being widely used in relevant item in the past.Through practice, show that this sealed window is reasonable.

Fig. 2 is the structural drawing of optical system, adopts 10 spherical mirrors to be positioned at same light path; Front negative group lens 1 comprise optical window 3, the first negative lens 4, the second negative lens 5, the first positive lens 6, the 3rd negative lens 7; After just organizing lens 2 and comprising the second positive lens 8, the 4th negative lens 9, the 3rd positive lens 10, the 4th positive lens 11, the 5th positive lens 12 that are positioned at successively same light path; The maximum effective aperture 130mm of camera lens, F number is 1.6; Camera lens overall length is 198mm.

Fig. 3 is the MTF figure of optical system, and MTF has represented the transmission capacity of optical system to target contrast, and its value is higher shows that aberration control is better.Because the minimum pixel of CCD is 22 μ m, its corresponding spatial frequency is 23lp/mm, for optical system is mated with CCD, must carry out actual investigation with the spatial frequency of 23lp/mm.Shown in Fig. 3, the MTF of 0.707 visual field under this spatial frequency, higher than 0.3 minimum process required value, can meet actual work requirements.

Optical system designs by infinite distance, and is limited distance during actual use.For the imaging definition camera lens that meets limited distance must be focused.Owing to having adopted spherical shell window himself to have a focal power, this window is irremovable in actual use, cannot be by mobile whole mirror group while therefore focusing.On this lens construction, adopted front and rear mirror group structure, front group of focal length be for negative, and rear group of focal length is for just.By the distance changing between rear group and front group, can realize lens focusing.Optical transfer function figure when Fig. 4,5 is respectively 5 meters of infinite object distances and 0.5 meter, now the amount of movement of group is respectively 0.092mm and 0.25mm afterwards.

In actual use, only need special imaging wide-angle lens to be under water sealed in seal casinghousing, then system is placed on to target area to be measured, can complete Real-Time Monitoring and shooting.Optical system is simple and practical, easy to operate, and can complete in real time wide-angle monitoring under water and take.

Claims

1. special imaging wide-angle lens under water, comprises front negative group of lens and is positioned at the rear lens of just organizing of same light path with front negative group of lens, it is characterized in that: described front negative group of lens and the rear lens of just organizing include at least four spherical mirrors that are positioned at same light path.

2. special imaging wide-angle lens under water according to claim 1, is characterized in that: described front negative group of lens comprise the optical window, the first negative lens, the second negative lens, the first positive lens, the 3rd negative lens that are positioned at successively same light path; The described rear lens of just organizing comprise the second positive lens, the 4th negative lens, the 3rd positive lens, the 4th positive lens, the 5th positive lens that are positioned at successively same light path.

3. special imaging wide-angle lens under water according to claim 2, is characterized in that: the maximum effective aperture 130mm of described camera lens, and F number 1.6, camera lens overall length is 198mm.

4. special imaging wide-angle lens under water according to claim 3, is characterized in that: described optical window is the concentric circles window of adopting quartz glass.