A kind of high picture element wide-angle optical lens
[technical field]
The utility model relates to a kind of optical lens, particularly relates to a kind of high picture element wide-angle optical lens.
[background technology]
The shortcoming that the mobile phone digital camera lens ubiquity of current use is such: field angle is relatively little, plastic cement lens structure, pixel improves difficulty, imaging picture taxes and profits degree is low.On market, the camera cell phone field angle of present main flow concentrates near 70 °, be difficult to breakthrough, pixel is below 1,300 ten thousand pixels, structure is the sharpness of plastic cement structure camera lens, the entirety of captured image picture element, and the aspects such as color reducibility are all not ideal enough, take in scenery scope little, in identical viewfinder range, need farther distance by scenery picked-up completely, so just could sacrifice sharpness.
The utility model, in order to overcome above shortcoming, has carried out a large amount of improvement.
[utility model content]
The utility model object overcomes the deficiencies in the prior art, and provide a kind of structure simple, field angle is 80 ° ~ 130 °, and pixel is 1,300 ten thousand ~ 1,600 ten thousand, ultra-thin, can be used for the high picture element wide-angle optical lens of digital camera and mobile phone.
The utility model is achieved through the following technical solutions:
A kind of high picture element wide-angle optical lens, is characterized in that: comprise lens barrel, includes in described lens barrel from thing side to image planes order:
First lens, the first described lens are falcate negative focal length plastic lens, its towards thing side first surface be hyperboloid aspheric surface, second towards image planes is circular aspheric;
First spacer ring;
Second lens, the second described lens are positive focal length glass lens, and two surface is glass sphere;
Second spacer ring, is provided with diaphragm at the middle through-hole place of the second described spacer ring;
3rd lens, the 3rd described lens are positive focal length plastic lens, and its first surface towards thing side is hyperbolic curve aspheric surface, and second towards image planes is oblate aspheric surface;
3rd spacer ring;
4th lens, the 4th described lens are negative focal length plastic lens, and two surface is hyperbolic curve aspheric surface;
4th spacer ring;
5th lens, the 5th described lens are positive focal length plastic lens, and its first surface towards thing side is oblate aspheric surface, and second towards image planes is hyperbola aspheric surface;
5th spacer ring;
6th lens, the 6th described lens are negative focal length plastic lens, and its first surface towards thing side is oblate aspheric surface, and second towards image planes is hyperbolic curve aspheric surface;
For fixing the pressure ring of the 6th lens.
High picture element wide-angle optical lens as above, it is characterized in that: the first described lens, second lens, 3rd lens, 4th lens, 5th lens, the element characteristic of the 6th lens meets following formula :-3.5<f1/f2<0, 0<f2/f3<3,-2<f4/f5<0,-3.5<f5/f6<3.5, vd2 >=30, vd 4≤30, vd1>40, vd3>40, vd5>40, vd6>40, vd 3-vd 4>20, vd 5-vd 4>10, vd 6-vd 4>10, wherein, f1, f2, f3, f4, f5, f6 is followed successively by the first lens, second lens, 3rd lens, 4th lens, 5th lens, the focal length of the 6th lens, vd 1 is the abbe number of the first lens, and vd 2 is the abbe number of the second lens, and vd 3 is the abbe number of the 3rd lens, and vd 4 is the abbe number of the 4th lens, and vd 5 is the abbe number of the 5th lens, and vd 6 is the abbe number of the 6th lens.
High picture element wide-angle optical lens as above, is characterized in that: be provided with for the protection of sensitive chip outside the 6th described lens and reduce the optical filter of veiling glare and hot spot.
High picture element wide-angle optical lens as above, is characterized in that: the aspheric surface configuration of the first described lens, the second described lens, the 3rd lens, the 4th lens, the 5th lens, the 6th lens meets following equation:
In formula, the curvature of parameter c corresponding to radius, y is radial coordinate (its unit is identical with length of lens unit), and k is circular cone whose conic coefficient; When k-factor is less than-1, the face shape curve of lens is hyperbolic curve, and when k-factor equals-1, the face shape curve of lens is para-curve; When k-factor is between-1 to 0, the face shape curve of lens is oval, and when k-factor equals 0, the face shape curve of lens is circular, and when k-factor is greater than 0, the face shape curve of lens is oblate; α 1 to α 8 represents the coefficient corresponding to each radial coordinate respectively.
Compared with prior art, the utility model has the following advantages:
1, the utility model is by 1 spheric glass, 5 non-spherical lenses composition, can realize the maximum wide-angle imaging to 130 degree, and pixel energy reaches more than 1,300 ten thousand.
2, the utility model is simple and compact for structure, and realize ultra-thin contour structures, thickness is less than 7.6mm.
3, the utility model have employed glass sphere and adds plastic aspherical element structure, therefore the Geometrical MTF of optical lens is greatly improved, and the sharpness of this product, transmitance, color reducibility can be made to be significantly improved.
[accompanying drawing explanation]
Fig. 1 is the utility model diagrammatic cross-section;
Fig. 2 is the utility model exploded view.
[embodiment]
Below in conjunction with accompanying drawing, the utility model is further described:
A kind of high picture element wide-angle optical lens, may be used for relatively cheap high pixel CMOS sensitive film, comprises lens barrel 1, include in described lens barrel 1 from thing side to image planes order:
First lens 2, the first described lens 2 are falcate negative focal length plastic lens, and its first surface towards thing side is hyperboloid aspheric surface, and second towards image planes is circular aspheric;
First spacer ring 8;
Second lens 3, the second described lens 3 are positive focal length glass lens, and two surface is glass sphere;
Second spacer ring 9, be provided with diaphragm 10 at the middle through-hole place of the second described spacer ring 9, diaphragm 10 is located at centre, can fully field angle be done greatly;
3rd lens 4, the 3rd described lens 4 are positive focal length plastic lens, and its first surface towards thing side is hyperbolic curve aspheric surface, and second towards image planes is oblate aspheric surface;
3rd spacer ring 11;
4th lens 5, the 4th described lens 5 are negative focal length plastic lens, and two surface is hyperbolic curve aspheric surface;
4th spacer ring 12;
5th lens 6, the 5th described lens 6 are positive focal length plastic lens, and its first surface towards thing side is oblate aspheric surface, and second towards image planes is hyperbola aspheric surface;
5th spacer ring 13;
6th lens 7, the 6th described lens 7 are negative focal length plastic lens, and its first surface towards thing side is oblate aspheric surface, and second towards image planes is hyperbolic curve aspheric surface, and the 6th lens 7 can improve curvature of field aberration well;
For fixing the pressure ring 14 of the 6th lens 7.
In order to reduce the change in refraction angle of light between each lens, be controlled to image distortion, the distance in structure as far as possible between reduction first lens 2 and the second lens 3.First lens 2 are negative focal length plastic lens, it can press little object height, the field angle of system is made to become large, diaphragm 10 is between the second lens 3 and the 3rd lens 4, second lens 3 and the 3rd lens 4 are positive focal length lens, so just effectively can correct distortion, ensure image quality, thus ensure that field angle can reach 130 °.Described second lens 3 adopt the glass sphere of high index of refraction (refractive index is greater than 1.8), can strengthen the refraction of light, and it can make the length of whole camera lens be as short as 7.5mm most.
The first described lens 2, second lens 3, 3rd lens 4, 4th lens 5, 5th lens 6, the element characteristic of the 6th lens 7 meets following formula :-3.5<f1/f2<0, 0<f2/f3<3,-2<f4/f5<0,-3.5<f5/f6<3.5, vd2 >=30, vd 4≤30, vd1>40, vd3>40, vd5>40, vd6>40, vd 3-vd 4>20, vd 5-vd 4>10, vd 6-vd 4>10, wherein, f1, f2, f3, f4, f5, f6 is followed successively by the first lens 2, second lens 3, 3rd lens 4, 4th lens 5, 5th lens 6, the focal length of the 6th lens 7, vd 1 is the abbe number of the first lens 2, and vd 2 is the abbe number of the second lens 3, and vd 3 is the abbe number of the 3rd lens 4, and vd 4 is the abbe number of the 4th lens 5, and vd 5 is the abbe number of the 5th lens 6, and vd 6 is the abbe number of the 6th lens 7.In optical texture, the focal length of the first lens 2 and the second lens 3 meets formula-3.5<f1/f2<0,0<f2/f3<3, during-2<f4/f5<0, focal length assignment problem and the tolerance distributing equilibrium sex chromosome mosaicism of the utility model structure can be solved, can effectively realize system wide-angle, length is ultra-thin and reduce structural tolerance tender subject.
The 4th described lens 5 and the 5th lens 6 adopt the positive focal length lens combination of the negative focal length lens of little abbe number and large abbe number, effectively can correct aberration, improve image quality, can have more clear perfect imaging effect under same pixel.
Be provided with for the protection of sensitive chip 15 outside the 6th described lens 7 and reduce the optical filter 16 of veiling glare and hot spot.Light enters from optical filter 16, and optical filter 16 pairs of sensitive chips 15 have certain protective effect, simultaneously also filters a part of light, reduces veiling glare and hot spot etc., make image color beautiful and sharp keen while there is good color reducibility.
The aspheric surface configuration of the first described lens 2, the second described lens 3, the 3rd lens 4, the 4th lens 5, the 5th lens 6, the 6th lens 7 meets following equation:
In formula, the curvature of parameter c corresponding to radius, y is radial coordinate (its unit is identical with length of lens unit), and k is circular cone whose conic coefficient; When k-factor is less than-1, the face shape curve of lens is hyperbolic curve, and when k-factor equals-1, the face shape curve of lens is para-curve; When k-factor is between-1 to 0, the face shape curve of lens is oval, and when k-factor equals 0, the face shape curve of lens is circular, and when k-factor is greater than 0, the face shape curve of lens is oblate; α 1 to α 8 represents the coefficient corresponding to each radial coordinate respectively.The utility model adopts glass sphere to add plastic aspherical element structure, the Geometrical MTF of optical lens is greatly improved, and the sharpness of this product, transmitance, color reducibility can be made to be significantly improved, and field angle can reach 130 °, pixel reaches 1,600 ten thousand, and thickness is less than 7.6mm.