CN209297022U

CN209297022U - A kind of big visual field object lens of large relative aperture LONG WAVE INFRARED optical system

Info

Publication number: CN209297022U
Application number: CN201821861591.1U
Authority: CN
Inventors: 张溪
Original assignee: Hebei Hanguang Heavy Industry Ltd
Current assignee: Hebei Hanguang Heavy Industry Ltd
Priority date: 2018-11-13
Filing date: 2018-11-13
Publication date: 2019-08-23
Anticipated expiration: 2028-11-13

Abstract

The utility model relates to a kind of big visual field object lens of large relative aperture LONG WAVE INFRARED optical systems, belong to optical technical field.The system comprises the first lens with positive light coke, the second lens with negative power, the third lens with positive light coke, focal plane protection glass and focal planes；Collimated light beam pass sequentially through the first lens, the second lens, the third lens and focal plane protection glass after reach focal plane on be imaged；Wherein, the first lens are chalcogenide glass material or germanium material, and the second lens are germanium material, and the third lens are chalcogenide glass material or germanium material, and it is germanium material that glass is protected in focal plane.The system effectively increases the transmitance of optical system under the premise of increasing optical system relative aperture, greatly strengthens the illuminance of image plane of system, improves image quality.

Description

A kind of big visual field object lens of large relative aperture LONG WAVE INFRARED optical system

Technical field

The utility model relates to LONG WAVE INFRARED optical systems, in particular to a kind of to have object lens of large relative aperture, the non-system of big visual field Cold mould fixed-focus LONG WAVE INFRARED optical system, belongs to optical technical field.

Background technique

Since LWIR Uncooled focus planar detector has simple structure, high reliablity, stability strong, at low cost Honest and clean, many advantages, such as weight is light, small volume, it is widely used in military products and civilian goods.Glasses for infrared use material Transmitance is generally relatively low, the corresponding sensitivity of uncooled detector spectrum is relatively low, so infrared band optical system requires to the greatest extent Possible big relative aperture.With the introducing use and the increasingly raising of processing technology of domestic diamond single-point vehicle, diffraction light Element is learned to be widely used in infrared optical system.

Publication No. be CN105487193A " F19mm object lens of large relative aperture machinery passive type without thermalization camera lens and compensation adjust Burnt method " only disclose in patent application a kind of focal length be 19mm, F/# (light by infinity incidence be formed by effective focal length F with The ratio of Entry pupil diameters # corresponding to paraxial rays) count the LONG WAVE INFRARED tight shot for being 1；Publication No. is CN105467549A " F5mm object lens of large relative aperture machinery passive type is without thermalization camera lens and its compensation adjustment method " patent application in disclose a kind of coke The LONG WAVE INFRARED camera lens of 384 × 288,17 μm away from the matching for being 1 for 5mm, F/# number face battle arrays, and its optical system is by four lens Composition；" a kind of object lens of large relative aperture long-focus uncooled ir without thermalization optical system " patent that publication No. is CN106990517A It is the LONG WAVE INFRARED tight shot that 500mm, F/# number are 1 that a kind of focal length is disclosed in application, but its optical system takes and turns back The structure of formula system, and it is other than using aluminum material as mirror lens, it is another to use 5 lens composition optical systems System；One is disclosed in " a kind of folding spread out mix object lens of large relative aperture without thermalization infrared objective " patent that publication No. is CN206960766U Kind focal length is the LONG WAVE INFRARED tight shot that 70mm, F/# number are 1, and which employs the forms of four Infrared Lens to complete；It announces Number to be announced in " a kind of low distortion wide-angle of object lens of large relative aperture grows infrared refractive and reflective optical system " patent of CN105116527A A kind of focal length is the long wave wide-angle fixed-focus infrared lens that 4.18mm, F/# number is 0.86, and which employs several bent moon negative lenses Form building with catoptric micro objective group completes optical system.

Above in the prior art, F/# number is largely F/1, and only one can achieve F/0.86.And at present in optical system Four or more lens numbers are generallyd use in system build process, although having reached object lens of large relative aperture in clear aperature Advantage, but its excessive lens numbers but reduces the transmitance of optical system, reduce infrared lens integral into image quality Amount.

Utility model content

In view of this, the purpose of this utility model is to provide a kind of big visual field object lens of large relative aperture LONG WAVE INFRARED optical systems System, the system effectively increase the transmitance of optical system, increase under the premise of increasing optical system relative aperture The strong illuminance of image plane of system, improves image quality；And with small in size, light-weight, structure is simple and high reliablity it is excellent Point.

To achieve the above object, the technical solution of the utility model is as follows.

A kind of big visual field object lens of large relative aperture LONG WAVE INFRARED optical system, the system comprises first with positive light coke thoroughly Mirror, the second lens with negative power, the third lens with positive light coke, focal plane protection glass and focal plane；In parallel Light beam passes sequentially through the first lens, the second lens, the third lens, focal plane protection glass, reaches and is imaged on focal plane；Wherein, First lens are chalcogenide glass material or germanium material, and the second lens are germanium material, and the third lens are chalcogenide glass material or germanium material Material, it is germanium material that glass is protected in focal plane.

Further, first lens first surface is spherical surface, and the first lens second surface is aspherical；Described second Lens first surface be it is aspherical, the second lens second surface be spherical surface；The third lens first surface is spherical surface, and third is saturating Mirror second surface is aspherical/diffraction surfaces；Aperture diaphragm is located on the first lens first surface.

Further, the focal length f1 of first lens, the total focal length f23 of the second lens and the third lens meet formula: 0.2<f1/f23<1.0.When relation above obtains meeting, optical system can get big visual field, and image quality can obtain significantly It improves.

Further, the focal length f1 of first lens, the focal length f2 of the second lens, meet formula: 0.02 < f1/f2 < 0.56.When relation above obtains meeting, the first lens of optical system and the distribution of the second power of lens are more suitable for, and are had Large visual field optical system conducive to acquisition and the aberration to system have good rectification effect.

Further, the focal length f2 of second lens, the focal length f3 of the third lens, meet formula: 0.25 < f2/f3 < 2.2.When relation above obtains meeting, the focal power distribution of the second lens and the third lens (3) of optical system is more suitable for, The large visual field optical system that help to obtain and there is good rectification effect to the aberration of system.

Further, the focal length f1 of first lens, the focal length f3 of the third lens, meet formula: 0.05 < f1/f3 < 1.0.When relation above obtains meeting, the first lens with positive light coke can reach maximally efficient allocation proportion, be Play the role of during system correction off-axis aberration good.

Further, the total focal length f12 of first lens and the second lens, the focal length f3 of the third lens, meets formula: 0.02<f12/f3<1.0.When relation above obtains meeting, the resolving power of optical system will be remarkably enhanced.

Further, the center thickness thic1 of first lens, along the first lens of optical axis direction and the second lens Optical interval d1 meets formula: 1.2 < thic1/d1 < 3.6.When relation above obtains meeting, is conducive to the assembly of lens, has Effect improves production efficiency.

Further, the center thickness thic2 of second lens, along the first lens of optical axis direction and the second lens Optical interval d1 meets formula: 0.2 < d1/thic2 < 1.3.When relation above obtains meeting, be conducive to being processed into for lens Type effectively raises production efficiency.

Further, saturating along the optical interval d1 of the first lens of optical axis direction and the second lens, the second lens and third The optical interval d2 of mirror, meets formula: 5.9 < d1/d2 < 9.0.Interval when relation above obtains meeting, between each lens It is more reasonable, be conducive to the assembly of camera lens, effectively improve yield rate.

Beneficial effect

A kind of big visual field object lens of large relative aperture LONG WAVE INFRARED optical system described in the utility model, 37 ° of < field angles (FOV) 74 ° of <, 0.8≤F/# (Fno)≤1, F/# maximum can achieve F/0.8, and field angle maximum can achieve 74 °, and use Lens number is less than 4, under the premise of increasing optical system relative aperture, effectively increases the transmitance of optical system, The illuminance of image plane for greatly strengthening system, improves image quality.

Detailed description of the invention

Fig. 1 is the structural schematic diagram of system described in the utility model.

Fig. 2 is the image-forming principle schematic diagram of system described in the utility model.

Specific embodiment

The present invention will be further described in detail below with reference to specific embodiments.

A kind of big visual field object lens of large relative aperture LONG WAVE INFRARED optical system, including with positive light coke the first lens 1, The second lens 2 with negative power, the third lens 3 with positive light coke, focal plane protection glass 4 and focal plane 5, come from The collimated light beam of infinity passes sequentially through the first lens 1, the second lens 2, the third lens 3, focal plane protection glass 4, reaches burnt It is imaged in plane 5.Wherein, chalcogenide glass material can be used in the first lens 1 or germanium material, the second lens 2 use germanium material, third It is germanium material that chalcogenide glass material or germanium material, focal plane protection glass 4, which can be used, in lens 3.

First lens first surface 101 is spherical surface, and the first lens second surface 102 is aspherical；Second lens One surface 201 be it is aspherical, the second lens second surface 202 be spherical surface；The third lens first surface 301 is spherical surface, the Three lens second surfaces 302 are aspherical/diffraction surfaces, this surface texture is general knowledge known in this field, i.e. face type is processed into aspheric After face, process on aspherical one by one diffraction ring band to reach diffracting effect, it is aspherical with diffraction surfaces simultaneously In the presence of aspherical to be used to correct spherical aberration, diffraction surfaces are used to correct color difference.

Aperture diaphragm is located on the first lens first surface 101.

In the present embodiment: (1) service band: 8 μm~12 μm；(2) detector: LWIR Uncooled focal plane detection 640 × 512,17 μm of device；(3) optical system overall length :≤30mm.

When the radius of curvature of each lens and thickness take different value, as shown in table 1, it can be achieved that the focal length f ' of system is minimum 9mm is up to 20mm；Minimum 37.5 ° of 2 ω of field angle, it is up to 74.1 °；Relative aperture D/f minimum 1/1, is up to 1/ 0.8；

Table 1

The MTF of system the result shows that optical system each visual field 0.5@30lp/mm of MTF >.

The point range figure of system the result shows that optical system in the disc of confusion of each visual field, respectively less than single detector surface picture First size.

In conclusion utility model includes but is not limited to above embodiments, it is all in the spirit and principles of the utility model Under any equivalent replacement or local improvement that carry out, all will be regarded as being within the protection scope of the utility model.

Claims

1. a kind of big visual field object lens of large relative aperture LONG WAVE INFRARED optical system, it is characterised in that: the system comprises with positive light focus The first lens (1) of degree, the second lens (2) with negative power, the third lens (3) with positive light coke, focal plane are protected It protects glass (4) and focal plane (5)；Collimated light beam passes sequentially through the first lens (1), the second lens (2), the third lens (3), Jiao Ping Glass (4) are protected in face, are reached and are imaged on focal plane (5)；Wherein, the first lens (1) be chalcogenide glass material or germanium material, second Lens (2) are germanium material, and the third lens (3) are chalcogenide glass material or germanium material, and it is germanium material that glass (4) are protected in focal plane.

2. a kind of big visual field object lens of large relative aperture LONG WAVE INFRARED optical system as described in claim 1, it is characterised in that: described the One lens first surface (101) is spherical surface, and the first lens second surface (102) is aspherical；Second lens first surface (201) to be aspherical, the second lens second surface (202) is spherical surface；The third lens first surface (301) is spherical surface, the Three lens second surfaces (302) are aspherical/diffraction surfaces；Aperture diaphragm is located on the first lens first surface (101).

3. a kind of big visual field object lens of large relative aperture LONG WAVE INFRARED optical system as claimed in claim 1 or 2, it is characterised in that: institute The focal length f1 of the first lens (1) is stated, the total focal length f23 of the second lens (2) and the third lens (3) meets formula: 0.2 < f1/f23 <1.0。

4. a kind of big visual field object lens of large relative aperture LONG WAVE INFRARED optical system as claimed in claim 1 or 2, it is characterised in that: institute The focal length f1 of the first lens (1) is stated, the focal length f2 of the second lens (2) meets formula: 0.02 < f1/f2 < 0.56.

5. a kind of big visual field object lens of large relative aperture LONG WAVE INFRARED optical system as claimed in claim 1 or 2, it is characterised in that: institute The focal length f2 of the second lens (2) is stated, the focal length f3 of the third lens (3) meets formula: 0.25 < f2/f3 < 2.2.

6. a kind of big visual field object lens of large relative aperture LONG WAVE INFRARED optical system as claimed in claim 1 or 2, it is characterised in that: institute The focal length f1 of the first lens (1) is stated, the focal length f3 of the third lens (3) meets formula: 0.05 < f1/f3 < 1.0.

7. a kind of big visual field object lens of large relative aperture LONG WAVE INFRARED optical system as claimed in claim 1 or 2, it is characterised in that: institute The total focal length f12 of the first lens (1) and the second lens (2) is stated, the focal length f3 of the third lens (3) meets formula: 0.02 < f12/ f3<1.0。

8. a kind of big visual field object lens of large relative aperture LONG WAVE INFRARED optical system as claimed in claim 1 or 2, it is characterised in that: institute State the center thickness thic1 of the first lens (1), along the optical interval of the first lens of optical axis direction (1) and the second lens (2) D1 meets formula: 1.2 < thic1/d1 < 3.6.

9. a kind of big visual field object lens of large relative aperture LONG WAVE INFRARED optical system as claimed in claim 1 or 2, it is characterised in that: institute State the center thickness thic2 of the second lens (2), along the optical interval of the first lens of optical axis direction (1) and the second lens (2) D1 meets formula: 0.2 < d1/thic2 < 1.3.

10. a kind of big visual field object lens of large relative aperture LONG WAVE INFRARED optical system as claimed in claim 1 or 2, it is characterised in that: edge The optical interval d1 of the first lens of optical axis direction (1) and the second lens (2), the second lens (2) and the third lens (3) optics It is spaced d2, meets formula: 5.9 < d1/d2 < 9.0.