CN202256848U - Wide-angle lens with non-spherical glued lens - Google Patents

Abstract

Disclosed is a wide-angle lens with non-spherical glued lenses, which comprises from an object space to an image space in order: a first lens, a second lens, a third lens, a fourth lens and a fifth lens, wherein the first and the second lens have negative focal powers; the third lens has a positive focal power; the fourth lens has a negative focal power and the fifth lens has a positive focal power; the fourth lens and the fifth lens are glued so as to form a glued lens with positive focal power; the matching plane of the glued lens is at least a non-spherical quadratic surface or more, and has a BFL/EFL (Back Focal Length/Effective Focal Length) not less than 3.0, wherein BFL is a distance from the outermost point at the image space side of the fifth lens to an imaging plane of the wide-angle lens, and EFL is the focal length of the wide-angle lens. The utility model can realize wide angle, small distortion, large relative aperture, super long total track length (TTL) and back focal length (BFL), and can ensure to keep a relatively perfect imaging sharpness within a relatively wide temperature range. The lens of the utility model is particularly applicable for outdoor monitoring and vehicle camera systems in severe environments.

Description

A kind of wide-angle lens with aspheric surface gummed eyeglass

Technical field

The utility model relates to a kind of wide-angle lens with aspheric surface gummed eyeglass, especially is fit to be applied to camera lens length overall TTL and operating distance BFL are required than monitoring camera and the installed video system of growing and have the serviceability temperature condition of broad.

Background technology

Wide-angle lens is general at present adopts 5 to 8 eyeglasses to form; It like Chinese patent number is 200910099703 wide-angle lens; Just adopt 4 sheet glass and 2 glass lens to form, but this wide-angle lens price is higher, can not satisfy customer requirement low price and high performance requirement.For this reason; Also having the wide-angle lens of Japanese enterprises exploitation to adopt the aspheric surface technology, reducing cost, like Chinese patent number is 200880106079 wide-angle lens; Just adopt 1 sheet glass eyeglass and 4 glass lens to form; But its logical optical property a little less than, the length overall TTL of camera lens and operating distance BFL are also shorter, can not satisfy client's specific (special) requirements.

The utility model content

In view of the above problems, the technical purpose of the utility model is to overcome the technological deficiency of existing wide-angle lens, provides that a kind of cost is low, in light weight, the wide-angle lens of the operating temperature range of large aperture, high-resolution and long operating distance and broad.

The related wide-angle lens of the utility model includes from object space to picture side successively: first lens and second lens with negative power; The 3rd lens with positive light coke; The 4th lens and the 5th lens with negative power with positive light coke; Said the 4th lens and the 5th lens glue together and form the balsaming lens with positive light coke, and the composition surface of said balsaming lens is at least quadratic power or above non-spherical surface, and satisfy:

BFL/EFL≥3.0

Wherein BFL be said wide-angle lens the 5th lens element picture side side outermost point to imaging surface distance here the BFL of indication be airborne distance, EFL is the focal length value of said wide-angle lens.

Said first lens are the curved month type eyeglass, and second lens are aspherical lens, and the 3rd lens are the biconvex eyeglass, and the convex surface on the composition surface of said balsaming lens is towards the object space side.

Further, also comprise diaphragm between said the 3rd lens and the 4th lens.Except first lens, have at least three to be the plastic aspherical element eyeglass in all the other four lens.

Through as above configuration, eyeglass quantity that just can enough minimums reaches gratifying optical characteristics and long operating distance.

Further, said first lens satisfy: Nd >=1.65, and Vd >=45, wherein Nd representes the d optical index of lens material, Vd representes the d light Abbe constant of lens material.First lens are through adopting refractive index Nd >=1.65, and the high-refractivity and low-dispersion material of Abbe constant Vd >=45 can effectively import the above light of 130 ° of field angle and reduce the bore of first eyeglass, and is excessive to avoid volume.

And described the 3rd lens and the 4th lens satisfy: Nd>=1.55, Vd≤30.

The 3rd lens are through adopting refractive index Nd>=1.55, and the high chromatic dispersion material of the high index of refraction of Abbe constant Vd≤30 can be assembled preceding two light that the negative power lens are come fast, and the effective value of chromatism in the compensation optical system of high chromatic dispersion material.

In addition, said camera lens also satisfies: TTL/EFL >=18, and wherein TTL is the distance of said camera lens first lens object space side outermost point to the imaging surface, EFL is the focal length value of said camera lens.

Further, the diaphragm of said camera lens satisfies: FNO≤2.2.

And satisfy on the composition surface of said balsaming lens: θ≤44 °, wherein θ is the tangent line of any point on the composition surface and the angle of optical axis.

Further, said camera lens also satisfies: FOV >=130, wherein FOV representes the total field angle of described optical lens.

In the wide-angle lens that the utility model relates to, first lens element adopts glass mirror, can effectively protect the in use scratch resistant scrape along opposing of optical lens rugged environment variable effect.Four eyeglasses of second lens to the, five lens; Through rational distribution focal power; Reaching preferably, temperature characterisitic requires (guaranteeing that promptly the temperature range at-40 ℃ to+85 ℃ has imaging definition preferably); Simultaneously, in order further to improve the temperature characterisitic effect, also can change the material of the 3rd lens element into glass material (because of the temperature characterisitic of glass material is better than plastic resin material) by plastic resin.

Said balsaming lens can effectively improve the aberration of optical system; And the generation that senior aberration ° can effectively be controlled in θ≤44 is satisfied on the composition surface; Conciliate as ability thereby be beneficial to the logical luminous energy power (aperture FNO≤2.2) that improves whole optical system, and effectively reduce the processing and the gluing technique requirement on composition surface.

The utility model is burnt BFL after keeping camera lens that long length overall TTL and camera lens are arranged; In the time of imageing sensor periphery electronic devices and components are bigger when satisfying camera design dimensional requirement; Also farther because of the long distance that makes lens element and optical filter leave imageing sensor of BFL; Can effectively reduce surface cleanliness requirement, more easily the assembling production of camera to each lens element and optical filter.

Description of drawings

Through the description of its exemplary embodiment being carried out below in conjunction with accompanying drawing, the above-mentioned feature and advantage of the utility model will become apparent and understand easily.

Fig. 1 is the structural representation that the utility model relates to the embodiment of the wide-angle lens with aspheric surface gummed eyeglass;

Fig. 2 is the axial chromatic aberration curve map of the utility model embodiment;

Fig. 3 is the chromatic longitudiinal aberration curve map of the utility model embodiment;

Fig. 4 is the astigmatism curve map of the utility model embodiment;

Fig. 5 is the distortion curve figure of the utility model embodiment;

Fig. 6 is the MTF curve map of the utility model embodiment.

Embodiment

Below in conjunction with accompanying drawing the utility model is described in further detail.

It is as shown in Figure 1 that the utility model relates to the structural representation of embodiment of the wide-angle lens with aspheric surface gummed eyeglass, said camera lens by the thing side to being followed successively by balsaming lens group, color filter GF, the imaging surface IMA that the first lens element L1, the second lens element L2, the 3rd lens element L3, diaphragm r7, the 4th lens element L4 and the 5th lens element L5 form as side.It is applied to visual angle >=130 ° in-vehicle camera system approximately especially.

The first lens element L1, it has negative focal power, is that the two sides all is the glass lens element of sphere; The second lens element L2 has negative focal power, is that the two sides all is the plastic lens elements of aspheric surface; The 3rd lens element L 3 has positive focal power, is that the two sides all is the aspherical plastic lens element of convex surface; The 4th lens element L4 has negative focal power, is that the two sides all is the plastic lens elements of aspheric surface; The 5th lens element L5 has positive focal power, is that the two sides all is the aspherical plastic lens element of convex surface.And the 4th lens element and the 5th passes through element and carries out the bonding balsaming lens group that forms through convex surface towards the aspheric surface joint of object space side.

Fig. 2 to Fig. 6 is the optical performance curve figure corresponding to case study on implementation; Wherein Fig. 2 is axial chromatic aberration curve map (also can be the spherical aberration curve map), by F, d, C (F=0.486um, d=0.588um commonly used; C=0.656um) wavelength of three coloured light is represented, unit is millimeter mm.Fig. 3 is the chromatic longitudiinal aberration curve, is represented by the wavelength of F commonly used, d, C three coloured light, and unit is micron um.Fig. 4 is the astigmatism curve map, representes that by the wavelength of F commonly used, d, C three coloured light unit is mm.Fig. 5 is distortion curve figure, representes the distortion sizes values under the different field angle situation, and unit is %.Fig. 6 is the MTF curve map, has represented the picture level of comprehensively separating of an optical system.Can know that by figure this optical lens is with various aberration corrections to a level preferably.

In this case study on implementation, the whole focal length value of this optical lens is EFL, and f-number is FNO, and field angle is FOV; Camera lens length overall TTL, and begin by the object space side, with each minute surface number consecutively, the minute surface of the first eyeglass L1 is r1, r2; The minute surface of the second eyeglass L2 is r3, r4, and the minute surface of prismatic glasses L3 is r5, r6, and the diaphragm face is r7; The minute surface of the 4th eyeglass L4 is r8, r9, and the minute surface of color filter GF is r10, r11, and the formula of aspherical mirror is:

$Z\left(h\right)=\frac{{\mathrm{ch}}^2}{1+\sqrt{1-(1+k)c^2{h}^2}}+{\mathrm{Ah}}^4+{\mathrm{Bh}}^6+{\mathrm{Ch}}^8+{\mathrm{Dh}}^{10}+{\mathrm{Eh}}^{12}$

In the formula: Z is an aspheric surface along optical axis direction highly for the position of h the time, apart from the aspheric surface summit apart from rise sag.

C=1/r, r represent the radius-of-curvature of minute surface, and k is circular cone coefficient conic, A, and B, C, D, E is the high order aspheric surface coefficient, and the e in the coefficient represents scientific notation, middle e-05 representes 10 ^-5

EFL＝1.27mm，FNO＝2.0，FOV＝164°，TTL＝25mm

The face sequence number	Radius-of-curvature r	Center thickness d	Refractive index Nd	Abbe constant Vd	Effective aperture D
						1	19	?0.99	1.729	54.7	14.36
2	4.149	?3.13			7.92
						*3	-8.237	?1.45	1.535	56.1	7.88
*4	3.137	?1.97			6.02

*5	10.534	4.96	1.585	29.9	6.07
						*6	-6.548	2.72			5.5
7	infinity	0.79			2.4
						*8	6.959	1	1.585	29.9	3.2
*9	1.444	3.45	1.535	56.1	4.16
						*10	-2.706	0.1			4.74
11	infinity	1	1.5168	64.16	4.7
						IMA	infinity	3.444			4.5

The minute surface of beating " * " number in the last table is an aspheric surface, and its correlation parameter is following:

That following table is listed is aspheric surface COEFFICIENT K, A, B, C, D, E:

According to above-mentioned case study on implementation data, the numerical value that calculates condition formula involved in claims is following:

Though described the principle and the embodiment of the utility model above to wide-angle lens with aspheric surface gummed eyeglass; But under the above-mentioned instruction of the utility model; Those skilled in the art can carry out various improvement and distortion on the basis of the foregoing description, and these improve or distortion all drops in the protection domain of the utility model.It will be understood by those skilled in the art that top specific descriptions just in order to explain the purpose of the utility model, and be not to be used to limit the utility model that the protection domain of the utility model is limited claim and equivalent thereof.

Claims (10)

1. one kind has the wide-angle lens that aspheric surface is glued together eyeglass; It is characterized in that; Include successively from object space to picture side: have first lens and second lens of negative power, have the 3rd lens of positive light coke, have the 4th lens and the 5th lens of negative power with positive light coke; Said the 4th lens and the 5th lens glue together and form the balsaming lens with positive light coke, and the composition surface of said balsaming lens is at least quadratic power or above non-spherical surface;

And, also satisfy:

BFL/EFL≥3.0

Wherein BFL is the distance of the 5th lens picture side side outermost point to imaging surface of said wide-angle lens, and the BFL of indication is airborne distance here, and EFL is the focal length value of said wide-angle lens.

2. wide-angle lens according to claim 1; It is characterized in that: said first lens are the curved month type eyeglass, and convex surface is towards object space, and second lens are aspherical lens; The 3rd lens are the biconvex eyeglass, and the convex surface on the composition surface of said balsaming lens is towards the object space side.

3. wide-angle lens according to claim 1 is characterized in that: be provided with diaphragm between said the 3rd lens and the 4th lens.

4. wide-angle lens according to claim 1 is characterized in that: said first lens satisfy:

Nd≥1.65，Vd≥45

Wherein Nd representes the d optical index of lens material, and Vd representes the d light Abbe constant of lens material.

5. wide-angle lens according to claim 1 is characterized in that: described the 3rd lens and the 4th lens satisfy:

Nd≥1.55，Vd≤30。

6. wide-angle lens according to claim 1 is characterized in that: said camera lens also satisfies:

TTL/EFL≥18

Wherein TTL is the distance of said camera lens first lens object space side outermost point to the imaging surface, and EFL is the focal length value of said camera lens.

7. wide-angle lens according to claim 1 is characterized in that: the diaphragm of said camera lens satisfies FNO≤2.2.

8. wide-angle lens according to claim 1 is characterized in that: satisfy on the composition surface of said balsaming lens:

θ≤44°

Wherein θ is the tangent line of any point on the composition surface and the angle of optical axis.

9. wide-angle lens according to claim 1 is characterized in that: said camera lens also satisfies:

FOV≥130

Wherein FOV representes the total field angle of described optical lens.

10. wide-angle lens according to claim 1 is characterized in that: have at least three to be the plastic aspherical element eyeglass in four lens of second lens to the, five lens.

Images