Wide-angle optical lens assembly
Technical field
The present invention relates to optical lens technical field, particularly relate to wide-angle optical lens assembly.
Background technology
In recent years, along with the continuous progress of science and technology, mobile phone becomes smaller and more exquisite, frivolous, portable, and therefore we need the overall length of control both optical camera lens as much as possible when designing camera lens; Simultaneously the becoming stronger day by day of cell-phone function, make people also become more and more higher to the requirement of mobile phone camera, this just requires that the design of camera lens can be reasonably combined with the imaging apparatus of high pixel in the market.For requiring that optical designers propose various structure above, being found by comparative studies, the lens construction be made up of three aspheric mirrors, various aberration can not only be corrected well, being also applicable to miniaturization, therefore adopt by a lot of camera system.But current three-chip type camera lens is little due to volume, and angle lens and overall length all do not reach the requirement of present cell-phone camera, needs wide-angle more, the lens assembly that lens length is less, sharpness is higher.
Summary of the invention
For solving the problem, the invention provides a kind of wide-angle optical lens assembly, wherein the shape of each lens, radius-of-curvature and THICKNESS CONTROL are in certain scope, and camera lens height is short, volume is little; Visual angle is wide, and image quality is high.
The technical solution adopted in the present invention is: a kind of wide-angle optical lens assembly, comprise from object side to the first lens becoming image side to be arranged in order, the second lens, the 3rd lens, optical filter and be located at the first lens and lean on into diaphragm in the face sequence of image side, described first lens have positive refracting power, its thing side surface dipped beam axle place is towards the convex surface of thing side, and its dipped beam axle place, surface, image side is towards the convex surface of image side; Described second lens have positive refracting power, and its thing side surface dipped beam axle place is towards the concave surface of thing side, and its dipped beam axle place, surface, image side is towards the convex surface of image side; Described 3rd lens have negative refracting power, and its thing side surface dipped beam axle place is towards the convex surface of thing side, and dipped beam axle place, surface, its image side is towards the concave surface of image side, and in its thing side and face, image side, at least one surface is provided with at least one point of inflexion; Imaging side sequence two radius of curvature R 2 of described first lens and the ratio of the total focal distance f of camera lens | R2/f|=2 ~ 3, the focal distance f 2 of described second lens and ratio f2/f=1 ~ 2 of the total focal distance f of camera lens, the ratio TTL/f<2.2 of described camera lens overall length TTL and the total focal distance f of camera lens, the overall length TTL<2.8mm of optical lens; The aspherical formula of described first lens, the second lens, the 3rd lens is:
Wherein, z represents the z coordinate value of lens surface each point, and r represents the Y-axis coordinate figure of each point on lens surface, and c is the inverse of the radius of curvature R of lens surface, and k is circular cone coefficient, a
1, a
2, a
3, a
4, a
5, a
6, a
7, a
8for asphericity coefficient.
Preferably, the radius of curvature R 1 of face sequence by thing side of described first lens meets following relation with the radius of curvature R 2 leaning on into the face sequence of image side of the first lens :-1< (R1+R2) (R1-R2) <0.
Preferably, the radius of curvature R 3 of face sequence by thing side of described second lens meets following relation with the radius of curvature R 4 leaning on into the face sequence of image side of the second lens: 12< (R3+R4) (R3-R4) <15.
Preferably, the abbe number V2>50 of described second lens.
Preferably, the refractive index n3>1.5 of described 3rd lens.
Preferably, the field angle of described optical lens is 80 ° ~ 90 °.
Preferably, the center thickness of described first lens is 0.32-0.335mm, and the center thickness of the second lens is 0.305-0.325mm, the center thickness of the 3rd lens is 0.315-0.325mm.
Described wide-angle optical lens assembly, beneficial effect is compared to existing technology:
First lens have positive refracting power, its front surface radius-of-curvature is just, namely towards the convex surface of thing side, thereafter surface curvature radius is negative, and rear surface is towards the convex surface of image side, and this type is conducive to still maintaining its miniaturization while increase field angle, this optical lens overall length is made to be less than 2.8mm, field angle 80 ° ~ 90 °, has wide-angle, ultra-thin, large aperture, highly short feature, caters to the demand of the preposition shooting mobile phone of current light and thin type; This face type also can make the variations in refractive index of light after lens comparatively relax.
3rd lens have negative refracting power, and the second lens have positive refracting power, can distribute the refracting power of the first lens, avoid refracting power concentrations on the first lens to reduce the susceptibility of optical lens assembly
The front surface radius-of-curvature of the second lens is negative, and be towards the concave surface of thing side, rear surface radius-of-curvature is similarly negative, and this face type contributes to revising astigmatism.The dipped beam axle place of the front surface of the 3rd lens is towards the convex surface of thing side, rear surface radius-of-curvature is just also, the distribution in massif shape from center to both sides, the design of this face type can suppress the angle of light on image photo-sensitive cell from axle visual field effectively, the response efficiency of photo-sensitive cell is promoted, and then increase image quality, and can the aberration of modified off-axis visual field further.
The optical distortion of this lens assembly is less than 1.5%, and the curvature of field is less than 0.1mm, and lateral chromatic aberration is less than 5um, and within Airy disk (diffraction spot) range of size, imaging distortion is little, and sharpness is high.
Accompanying drawing explanation
Fig. 1 is the structural representation of embodiment of the present invention wide-angle optical lens assembly;
Fig. 2 is the curvature of field, the distortion curve figure of embodiment of the present invention wide-angle optical lens assembly;
Fig. 3 is the spherical aberration curve map of embodiment of the present invention wide-angle optical lens assembly;
Fig. 4 is the chromatic curve figure of embodiment of the present invention wide-angle optical lens assembly.
Embodiment
Below in conjunction with accompanying drawing, the present invention is further illustrated.
Embodiment:
With reference to Fig. 1, optical lens assembly of the present invention, it is a kind of aspheric mobile lens, it comprises from object side to the first lens 1, second lens 2 becoming image side to be arranged in order, the 3rd lens 3, optical filter 4 and the diaphragm 5 be located between thing side and the second lens 2, and diaphragm 5 can adopt preposition and mid-mode (being that diaphragm is mid-in figure).
First lens 1 have positive refracting power, and face sequence 11 radius-of-curvature of its thing side is just and is the convex surface towards thing side, and face sequence 12 radius-of-curvature of one-tenth image side is negative and dipped beam axle place is towards the convex surface of image side; Second lens 2 have positive refracting power, and the face sequence radius-of-curvature of its thing side 21 is negative, and dipped beam axle place is the concave surface of opening towards thing side, and face sequence 22 radius-of-curvature of one-tenth image side is negative and dipped beam axle place is towards the convex surface becoming image side; 3rd lens 3 have negative refracting power, the face sequence 31 dipped beam axle place of its thing side is towards the convex surface of thing side, the face sequence 32 dipped beam axle place of image side is become to be that opening is towards the concave surface becoming image side, in its thing side and face, image side, at least one surface is provided with at least one point of inflexion, and in the present embodiment, the thing side of the 3rd lens 3 and surface, image side are all provided with the point of inflexion.
The aspherical formula of the first lens, the second lens, the 3rd lens is:
Wherein, z represents the z coordinate value of lens surface each point, and r represents the Y-axis coordinate figure of each point on lens surface, and c is the inverse of the radius of curvature R of lens surface, and k is circular cone coefficient, a
1, a
2, a
3, a
4, a
5, a
6, a
7, a
8for asphericity coefficient.
Wherein, the center thickness of the first lens is 0.32-0.335mm, and the center thickness of the second lens is 0.305-0.325mm, the center thickness of the 3rd lens is 0.315-0.325mm; Imaging side sequence two radius of curvature R 2 of the first lens and the ratio of the total focal distance f of camera lens | R2/f|=2 ~ 3, the focal distance f 2 of the second lens and ratio f2/f=1 ~ 2 of the total focal distance f of camera lens, the ratio TTL/f<2.2 of camera lens overall length TTL and the total focal distance f of camera lens, the overall length of optical lens is less than 2.8mm.
The radius of curvature R 1 of face sequence 11 by thing side of the first lens 1 meets following relation with the radius of curvature R 2 leaning on into the face sequence 12 of image side of the first lens 1 :-1< (R1+R2) (R1-R2) <0.
The radius of curvature R 3 of face sequence 21 by thing side of the second lens 2 meets following relation with the radius of curvature R 4 leaning on into the face sequence 22 of image side of the second lens 2: 12< (R3+R4) (R3-R4) <15.
The abbe number V2>50 of the second lens 2.
The refractive index n3>1.5 of the 3rd lens 3.
The field angle of this optical lens is 80 ° ~ 90 °.
Concrete data, as table one, specifically can arrange lens combination according to these data:
The each lens data table of table one mobile phone lens assembly
This programme adopts the non-spherical lens of three resin materials, special lens shape and comparatively reasonably optical parameter design, make that Jiao after this lens assembly machinery is longer, the total length of optics, image quality is high and tolerance sensitivities is lower, can ensure higher production yield.
First lens have positive refracting power, its front surface radius-of-curvature is just, namely towards the convex surface of thing side, thereafter surface curvature radius is negative, rear surface is towards the convex surface of image side, this type is conducive to still maintaining its miniaturization when increasing field angle, and the variations in refractive index of light after lens also can be made comparatively to relax.
3rd lens have negative refracting power, and the second lens have positive refracting power, can distribute the refracting power of the first lens, avoid refracting power concentrations on the first lens to reduce the susceptibility of optical lens assembly.The front surface radius-of-curvature of the second lens is negative, is towards the concave surface of thing side; Rear surface radius-of-curvature is similarly negative, and namely towards the convex surface of image side, this face type contributes to revising astigmatism.There is negative refracting power, its front surface radius-of-curvature is just, and centered by the dipped beam axle place of the front surface of described 3rd lens position towards the convex surface of thing side, rear surface radius-of-curvature is just also, the distribution in massif shape from center to both sides, the design of this face type can suppress the angle of light on image photo-sensitive cell from axle visual field effectively, and the response efficiency of photo-sensitive cell is promoted, and then increase image quality, and can the aberration of modified off-axis visual field further.
This optical lens overall length is less than 2.8mm, field angle 80 ° ~ 90 °, has the feature of wide-angle, ultra-thin, large aperture, ultra-wide angle large aperture mobile lens, and shooting viewfinder range is comparatively large, and picture is limpid in sight, caters to the demand of the preposition shooting mobile phone of current light and thin type; Compared with two panels aspheric lens, adopt the structure of three aspherical lens, can effectively correct all kinds of aberrations such as the curvature of field, astigmatism, ratio chromatism.Use resins for universal use material on the market to replace glass, easy-formation and manufacturing process is ripe simultaneously, solve the low problem higher with cost of product yield that glass mirror causes because of processing difficulties;
With reference to Fig. 2, the optical distortion of this optical lens assembly is less than 1.5%, and the curvature of field is less than 0.1mm; With reference to Fig. 3,4, lateral chromatic aberration is less than 5um, and within Airy disk (diffraction spot) range of size, imaging distortion is little, and sharpness is high.
The above embodiment only have expressed several embodiment of the present invention, and it describes comparatively concrete and detailed, but therefore can not be interpreted as the restriction to the scope of the claims of the present invention.It should be pointed out that for the person of ordinary skill of the art, without departing from the inventive concept of the premise, can also make some distortion and improvement, these all belong to protection scope of the present invention.Therefore, the protection domain of patent of the present invention should be as the criterion with claims.