CN209433109U

CN209433109U - A kind of infrared confocal camera lens of ultrashort t TL

Info

Publication number: CN209433109U
Application number: CN201822211102.4U
Authority: CN
Inventors: 罗吉祥; 肖明志
Original assignee: Union Optech Co Ltd
Current assignee: Union Optech Co Ltd
Priority date: 2018-12-26
Filing date: 2018-12-26
Publication date: 2019-09-24
Anticipated expiration: 2028-12-26

Abstract

The utility model discloses a kind of infrared confocal camera lenses of ultrashort t TL, the main points of its technical scheme are that being disposed with the first lens, diaphragm, the second lens, the third lens, the 4th lens, optical filter, protection glass, sensitive chip from object side to image side.The focal length of first lens is negative；The focal length of second lens to the 4th lens is positive；The concave, convex composite structure that each lens of the utility model use can preferably be realized infrared confocal by selecting the material of appropriate index and reasonably distribute focal power, and reduce camera lens TTL, while realize that temperature drift amount is small and without purple boundary.

Description

A kind of infrared confocal camera lens of ultrashort t TL

[technical field]

The utility model relates to a kind of infrared confocal camera lenses of ultrashort t TL.

[background technique]

It is infrared it is confocal be vehicle-mounted, security industry proposes at present lens technology specification, be the development trend of future market.So And at present most is used for vehicle-mounted, security protection infrared confocal camera lens, generally existing infrared visible defocusing amount is big, is difficult simultaneously Realize the fine definition requirement of night even on daytime, TTL length is big, be not able to satisfy many vehicle-mounted, security protection occasions for camera lens outside The requirement of shape, clarity degradation under high and low temperature environment, temperature drift is big, and camera lens purple boundary phenomenon under visible mode is tight Weight, overall volume are larger.

The utility model is namely based on what such case was made.

[utility model content]

The utility model aim is to overcome the deficiencies in the prior art, provides a kind of Low Drift Temperature, without purple boundary, small in size, red The infrared confocal camera lens of the small ultrashort t TL of outer defocusing amount.

The utility model is achieved through the following technical solutions:

A kind of infrared confocal camera lens of ultrashort t TL, it is characterised in that: the first lens 1, light are disposed with from object side to image side Late 2, second lens 3, the third lens 4, the 4th lens 5, optical filter 6, protection glass 7, sensitive chip 8；

Each lens have object side and an image side surface, respectively the first lens object side S1, the first lens image side surface S2, Second lens object side S3, the second lens image side surface S4, the third lens object side S5, the third lens image side surface S6, the 4th lens Object side S7, the 4th lens image side surface S8；

First lens object side S1 is convex surface, and the first lens image side surface S2 is concave surface, and the focal length of the first lens 1 is negative；

Second lens object side S3 is concave surface, the second lens image side surface S4 is convex surface, and the focal length of the second lens 3 is positive；

The third lens object side S5 and the third lens image side surface S6 is convex surface, and the focal length of the third lens 4 is positive；

4th lens object side S7 and the 4th lens image side surface S8 is concave surface；The focal length of 4th lens 5 is positive.

The infrared confocal camera lens of ultrashort t TL as described above, it is characterised in that the camera lens meets following relationship:

- 1.5 < f₁/ f < -0.5；

0.5 < f_2-4/ f < 1.5；

5 < f_3-4/ f < 15；

2 < TTL/f < 5；

Wherein, f is the focal length of the camera lens, f₁For the focal length of the first lens 1, f_2-4For the second lens 3 to the 4th lens 5 Combined focal length, f_3-4For the combined focal length of the third lens 4 and the 4th lens 5, TTL is the overall length of the infrared confocal camera lens.

The infrared confocal camera lens of ultrashort t TL as described above, it is characterised in that the infrared confocal camera lens of ultrashort t TL meets following Relational expression:

Nd₁≥1.7；

Nd₂≥1.6；

|Nd₂- Nd₃|≤0.3；

|Nd₃- Nd₄|≥0.12；

Wherein, Nd₁For the refractive index of the first lens 1, Nd₂For the refractive index of the second lens 3, Nd₃For the folding of the third lens 4 Penetrate rate, Nd₄For the refractive index of the 4th lens 5.

The infrared confocal camera lens of ultrashort t TL as described above, it is characterised in that: first lens 1 are non-spherical lens, institute The second lens 3, the third lens 4, the 4th lens 5 stated are spherical lens.

The infrared confocal camera lens of ultrashort t TL as described above, it is characterised in that: the spherical lens is glass spherical lens, The non-spherical lens is glass aspheric lenses.

lens₁< 50, lens₂> 50；

|lens₃- lens₄|≥25；

0.5≤lens₁/lens₂≤1；

Wherein, lens₁For the abbe number of the first lens 1, lens₂For the abbe number of the second lens 3, lens₃For third The abbe number of lens 4, lens₄For the abbe number of the 4th lens 5.

(A₁₂+A₂₃)/TTL < 0.2；

0.5 < (T₁+T₂+T₃+T₄)/TTL < 0.8；

0.1 < BF/TTL < 0.5；

Wherein, A₁₂For the airspace distance between the first lens 1 and the second lens 3, A₂₃For the second lens 3 and third Airspace distance between lens 4, airspace distance of the BF between the 4th lens 5 and sensitive chip 8, T₁Thoroughly for first The center thickness of mirror 1, T₂For the center thickness of the second lens 3, T₃For the center thickness of the third lens 4, T₄For the 4th lens 5 Center thickness, TTL are the overall length of the camera lens.

Compared with prior art, the utility model has the following advantages:

1, the concave, convex composite structure that each lens of the utility model use, by the material and the conjunction that select appropriate index Reason ground distribution focal power, can preferably realize infrared confocal, and reduce camera lens TTL, while realize that temperature drift amount is small and nothing Purple boundary.

2, the structure of the utility model selection three pieces glass spheric glass and a piece of Glass aspheric eyeglass, by rationally controlling Each lens thickness and airspace distance are made, realizes that TTL is short, it is small in size.

3, the utility model have the characteristics that infrared defocusing amount is small, TTL is short, temperature drift is small, without purple boundary, small in size, be suitble to push away Wide application.

[Detailed description of the invention]

Fig. 1 is the structural schematic diagram of the utility model；

Fig. 2 is the overfocus curve graph of the utility model embodiment visible waveband at normal temperature；

Fig. 3 is the overfocus curve graph of the utility model embodiment infrared band at normal temperature；

Fig. 4 is overfocus curve graph of the utility model embodiment in -40 DEG C of visible wavebands of low temperature；

Fig. 5 is overfocus curve graph of the utility model embodiment in+100 DEG C of visible wavebands of high temperature；

The encirclement circle energy curve that Fig. 6 is the utility model embodiment visible mode 435nm.

In figure: 1 is the first lens；2 be diaphragm；3 be the second lens；4 be the third lens；5 be the 4th lens；6 be optical filtering Piece；7 be protection glass；8 be sensitive chip；S1 is the first lens object side；S2 is the first lens image side surface, S3 is the second lens Object side, S4 are the second lens image side surface, S5 is the third lens object side, S6 is the third lens image side surface, S7 is the 4th lens Object side, S8 are the 4th lens image side surface；S9 is optical filter object side；S10 is optical filter image side surface；S11 is protection glass object Side；S12 is protection glass image side surface.

[specific embodiment]

The utility model technical characteristic is described in further detail in order to the field technology people with reference to the accompanying drawing Member it will be appreciated that.

As shown in Figures 1 to 6, the infrared confocal camera lens of a kind of ultrashort t TL, the first lens are disposed with from object side to image side 1, diaphragm 2, the second lens 3, the third lens 4, the 4th lens 5, optical filter 6, protection glass 7, sensitive chip 8；

Each lens have object side and an image side surface, respectively the first lens object side S1, the first lens image side surface S2, Second lens object side S3, the second lens image side surface S4, the third lens object side S5, the third lens image side surface S6, the 4th lens Object side S7, the 4th lens image side surface S8；The two sides of optical filter 6 is respectively optical filter object side S9 and optical filter image side surface S10； The two sides for protecting glass is respectively to protect glass object side S11 and protection glass image side surface S12.

The third lens object side S5 and the third lens image side surface S6 is convex surface, and the focal length of the third lens 4 is positive.

4th lens object side S7 and the 4th lens image side surface S8 is concave surface, and the focal length of the 4th lens 5 is negative.

Each lens of the utility model are using concave, convex composite structure and the composite structure of positive and minus focal, by reasonably distributing Focal power can preferably reduce infrared visible defocusing amount, thus realize it is infrared confocal, while realize reduce temperature drift amount, The clarity for guaranteeing that camera lens is imaged in high and low temperature environment is unaffected.

As shown in Figure 1, in the present embodiment, the ultrashort t TL is infrared, and confocal camera lens camera lens meets following relationship:

- 1.5 < f₁/ f < -0.5；

0.5 < f_2-4/ f < 1.5；

5 < f_3-4/ f < 15；

2 < TTL/f < 5；

The utility model meets the lens combination structure of above-mentioned each focal length of lens relationship, can each lens of reasonable distribution Focal power improves imaging definition, while realizing confocal outside visible red, reduces temperature drift amount, and can be shortened optical path length Degree reduces camera lens TTL.

The infrared confocal camera lens of ultrashort t TL as described above, ultrashort t TL is infrared, and confocal camera lens meets following relationship:

Nd₁≥1.7；

Nd₂≥1.6；

|Nd₂- Nd₃|≤0.3；

|Nd₃- Nd₄|≥0.12；

The utility model meets the lens combination structure of above-mentioned each index of refraction in lens relationship, can relatively easily realize The aberrations such as focal power reasonable distribution, preferably spherical aberration corrector, the curvature of field, coma, to improve visible and infrared band imaging clearly Degree, meets infrared confocal requirement, while each index of refraction in lens varies with temperature relationship, preferable temperature-compensating function may be implemented Can, to reduce temperature drift amount, in addition, improving the refractive index of the first lens, is conducive to the angle of compression light beam and optical axis, subtracts Tiny lens bore is realized and reduces camera lens volume.

The infrared confocal camera lens of ultrashort t TL as described above, first lens 1 are non-spherical lens, and described second thoroughly Mirror 3, the third lens 4, the 4th lens 5 are spherical lens.

The utility model is reduced eyeglass and is used number using a piece of aspherical mirror and the fit system of three pieces spherical mirror Amount, by optimization lens curvature and face type, the aberrations such as energy preferable spherical aberration corrector, the curvature of field, astigmatism, to reduce the TTL of camera lens And volume.

The infrared confocal camera lens of ultrashort t TL as described above, the spherical lens is glass spherical lens, described aspherical Mirror is glass aspheric lenses.

The utility model uses the non-spherical lens and spherical mirror of glass material, and thermal refractive index coefficient is small, and high/low temperature Lower thermal expansion coefficient is small, can easily realize the small requirement of temperature drift amount, in addition, using the spherical lens of glass material, optical lens Rate height is crossed, and hardness is higher than common plastic lens, is more suitable for eyeglass and needs exposed environment, be able to satisfy vehicle-mounted industry to mirror The high request of head property patience.

lens₁< 50, lens₂> 50；

|lens₃- lens₄|≥25；

0.5≤lens₁/lens₂≤1；

The utility model meets the lens combination structure of above-mentioned each lens achromatic Relationship of Coefficients, and preferable color may be implemented Poor calibration capability realizes infrared confocal requirement to improve visible and infrared band imaging definition, in addition, being closed by selection The glass material of suitable abbe number, emphasis optimize the color difference and disc of confusion of short wavelength, realize camera lens without purple boundary.

(A₁₂+A₂₃)/TTL < 0.2；

0.5 < (T₁+T₂+T₃+T₄)/TTL < 0.8；

0.1 < BF/TTL < 0.5；

The utility model meets the lens combination structure of above-mentioned size relationship, under the premise of guaranteeing lens optical performance, The TTL that can be shortened camera lens reduces the overall volume of camera lens.

The focal length f=3.93mm, relative aperture FN0=of the infrared confocal camera lens of ultrashort t TL in one of the embodiments, 2.4, FOV=76 ° of field angle, camera lens overall length is only TTL=10.78mm, and each eyeglass maximum effective aperture is 3.58mm in camera lens, Entire finished product camera lens small volume, visible waveband used are 435~656nm, and infrared band is 900~980nm, and each lens are every Design parameter is as shown in the table:

Face number	Radius R	Thickness	Refractive index Nd	Abbe number Vd	Bore
						Object side	Infinity	500			782.69
*S1	2.696	0.519	1.834	37.285	2.48
						*S2	1.483	0.551			1.87
Diaphragm	Infinity	0.072			1.67
						S3	-29.041	3.042	1.729	54.669	1.72
S4	-2.494	0.085			3.11
						S5	5.201	1.801	1.593	68.525	3.38
S6、S7	-3.097	1.214	1.755	27.547	3.38
						S8	13.174	1			3.58
S9	Infinity	0.3	1.517	64.212	3.94
						S10	Infinity	1.694			4.02
S11	Infinity	0.40	1.517	64.212	4.73
						S12	Infinity	0.1			4.84
Image side	Infinity				4.89

In upper table, the unit of radius R and thickness is millimeter；Marking the face of " * " indicates aspherical, aspherical lens Face type meet following relationship:

In formula, parameter c is curvature corresponding to lens radius, and y is radial coordinate, the unit and length of lens of radial coordinate Unit is identical, and k is circular cone whose conic coefficient；When k-factor is less than -1, the face shape curve of lens is hyperbola, when k-factor etc. When -1, the face shape curve of lens is parabola；When k-factor is between -1 to 0, the face shape curve of lens is ellipse, works as k When coefficient is equal to 0, the face shape curve of lens is circle, and when k-factor is greater than 0, the face shape curve of lens is oblateness；a₁To a₈ Respectively indicate coefficient corresponding to each radial coordinate.Detailed aspherical relevant parameter is as shown in the table:

	k	a₁	a₂	a₃	a₄	a₅	a₆	a₇	a₈
										*S1	0	0	-0.02052125	-0.0063673363	0.00065892072	0	0	0	0
*S2	0	0	-0.019709338	-0.016820616	0.0016206433	0	0	0	0

The optical property of the utility model camera lens is as shown in Figures 2 to 6, and wherein Fig. 2 to Fig. 5 is ultrashort in this programme The overfocus curve graph of the infrared confocal camera lens of TTL, for evaluating the solution of optical system different location before and after optimum image plane position As capacity variation situation.

Fig. 2 curve indicates the design result of visible waveband under room temperature, and Fig. 3 curve indicates the design knot of infrared band under room temperature Fruit, comparison diagram 2 and Fig. 3 curve, the corresponding abscissa offset of the two peak value is only 13um, and mtf value is very high at optimum image plane, Illustrate that infrared visible confocal degree is preferable, defocusing amount is small, infrared optical mode is switched to from visible mode, without re-starting pair Coke can be obtained extraordinary image quality.

Fig. 4 is the overfocus curve graph of -40 DEG C of visible wavebands of low temperature, and Fig. 5 is the overfocus of+100 DEG C of visible wavebands of high temperature Curve graph, comparison diagram 2, Fig. 4 and Fig. 5, it can be seen that under high/low temperature condition, back focus offset amount is very small, low with normal temperature phase ratio Warm drift value is only that -4um, high temperature drift amount only+5um hardly cause imaging effect at this point, mtf value is still very high It influences, therefore under high and low temperature environment, is still able to maintain extraordinary imaging effect.

Energy curve is justified in the encirclement that Fig. 6 is visible mode 435nm, and the ratio of energy is surrounded in the circle for evaluating designated diameter Example, it can be seen from the figure that the 435nm light centrality of the infrared confocal camera lens of ultrashort t TL in this programme is very good, 0.76 view The energy of light 70% concentrates within 3um in, for the sensitive chip of common 3um pixel, can preferably guarantee Imaging effect is not in purple boundary phenomenon.

Embodiment described in the utility model is only the description carried out to preferred embodiments of the present invention, not Utility model conception and scope is defined, under the premise of not departing from the design concept of the utility model, engineering in this field The all variations and modifications that technical staff makes the technical solution of the utility model should all fall into the protection model of the utility model It encloses.

Claims

1. a kind of infrared confocal camera lens of ultrashort t TL, it is characterised in that: be disposed with the first lens (1), light from object side to image side Late (2), the second lens (3), the third lens (4), the 4th lens (5), optical filter (6), protection glass (7), sensitive chip (8)；

Each lens have object side and an image side surface, respectively the first lens object side (S1), the first lens image side surface (S2), Second lens object side (S3), the second lens image side surface (S4), the third lens object side (S5), the third lens image side surface (S6), 4th lens object side (S7), the 4th lens image side surface (S8)；

First lens object side (S1) is convex surface, and the first lens image side surface (S2) is concave surface, and the focal length of the first lens (1) is negative；

Second lens object side (S3) is concave surface, the second lens image side surface (S4) is convex surface, and the focal length of the second lens (3) is positive；

The third lens object side (S5) and the third lens image side surface (S6) are convex surface, and the focal length of the third lens (4) is positive；

4th lens object side (S7) and the 4th lens image side surface (S8) are concave surface；The focal length of 4th lens 5 is positive.

2. the infrared confocal camera lens of ultrashort t TL according to claim 1, it is characterised in that the camera lens meets following relationship:

- 1.5 < f₁/ f < -0.5；

0.5 < f_2-4/ f < 1.5；

5 < f_3-4/ f < 15；

2 < TTL/f < 5；

Wherein, f is the focal length of the camera lens, f₁For the focal length of the first lens (1), f_2-4For the second lens (3) to the 4th lens (5) Combined focal length, f_3-4For the combined focal length of the third lens (4) and the 4th lens (5), TTL is the overall length of the infrared confocal camera lens.

3. the infrared confocal camera lens of ultrashort t TL according to claim 1, it is characterised in that the infrared confocal camera lens of ultrashort t TL Meet following relationship:

Nd₁≥1.7；

Nd₂≥1.6；

|Nd₂- Nd₃|≤0.3；

|Nd₃- Nd₄|≥0.12；

Wherein, Nd₁For the refractive index of the first lens (1), Nd₂For the refractive index of the second lens (3), Nd₃For the third lens (4) Refractive index, Nd₄For the refractive index of the 4th lens (5).

4. the infrared confocal camera lens of ultrashort t TL according to claim 1, it is characterised in that: first lens (1) are aspheric Face lens, second lens (3), the third lens (4), the 4th lens (5) are spherical lens.

5. the infrared confocal camera lens of ultrashort t TL according to claim 4, it is characterised in that: the spherical lens is glass marble Face lens, the non-spherical lens are glass aspheric lenses.

6. the infrared confocal camera lens of ultrashort t TL according to claim 1, it is characterised in that the infrared confocal camera lens of ultrashort t TL Meet following relationship:

lens₁< 50, lens₂> 50；

|lens₃- lens₄|≥25；

0.5≤lens₁/lens₂≤1；

Wherein, lens₁For the abbe number of the first lens (1), lens₂For the abbe number of the second lens (3), lens₃For third The abbe number of lens (4), lens₄For the abbe number of the 4th lens (5).

7. the infrared confocal camera lens of ultrashort t TL according to claim 1, it is characterised in that the infrared confocal camera lens of ultrashort t TL Meet following relationship:

(A₁₂+A₂₃)/TTL < 0.2；

0.5 < (T₁+T₂+T₃+T₄)/TTL < 0.8；

0.1 < BF/TTL < 0.5；

Wherein, A₁₂For the airspace distance between the first lens (1) and the second lens (3), A₂₃For the second lens (3) and third Airspace distance between lens (4), airspace distance of the BF between the 4th lens (5) and sensitive chip (8), T₁For The center thickness of first lens (1), T₂For the center thickness of the second lens (3), T₃For the center thickness of the third lens (4), T₄For The center thickness of 4th lens (5), TTL are the overall length of the camera lens.