Optical lens assembly
Technical field
The utility model relates to the optical device field, relates more specifically to the optical lens assembly in a kind of camera module that is applicable to 1/4 inch specification 5,000,000 pixel in the mobile communications tool field.
Background technology
Along with the continuous progress of the development of economy and society, for people provide the more and more abundanter consumer goods, thereby enrich people's material life condition, and then promote people's living standard, and mobile communications tool is exactly a kind of in many consumer goods.
Wherein, in mobile communications tool, it is the most frequently used a kind of in the mobile communications tool that mobile phone belongs to, its life that appears as people and work bring many convenience, therefore, people are not limited only to the small and exquisite of speech communication function and outward appearance so that carry to the functional requirement of mobile phone, also require simultaneously mobile phone to possess more powerful additional function, and are first-class such as subsidiary high-pixel camera.
At present, be subject to pursuing of consumers in general with the mobile phone of camera function, simultaneously, trend towards ultra-thin mobile phone and favored by the consumer, thereby force the design of camera lens to pursue shorter optics overall length and higher pixel.And in the actual design of optical lens assembly, should consider the imaging effect of camera lens, and consider that again camera lens possesses good working ability to reduce production costs, also to consider the factors such as production in enormous quantities of camera lens.The consumer more thirsts for obtaining the mobile phone of higher price-performance ratio simultaneously, and the camera cost of high pixel is higher, the price of mobile phone is corresponding improve also, so, in order to satisfy widely consumer demand, under the prerequisite that promotes camera photograph sharpness, to reduce its production cost as purpose, need the short camera lens of the new optics overall length of development and Design to adapt to the demand in market.But the lens assembly that has now in the camera module that is applied to 1/4 inch specification 5,000,000 pixel but exists the defective that imaging effect is poor and optics is always grown up and cost is high.
Therefore, demand a kind of optical lens assembly urgently and overcome above-mentioned defective.
The utility model content
A purpose of the present utility model is to provide the optical lens assembly that a kind of imaging effect is good, the optics overall length is little and cost is low.
To achieve these goals, the utility model provides a kind of optical lens assembly, comprises mid-diaphragm, lens combination and glass filter.Described lens combination comprises first lens, the second lens and the 3rd lens that arrange with optical axis, described first lens, the second lens and the 3rd lens set gradually along object space to picture side, and the surface of described first, second and third lens is aspheric surface, and this aspheric surface formula is:
Wherein, Z represents the Z coordinate figure of each point on the lens surface, Y represents the Y-axis coordinate figure of each point on the lens surface, CURV is the inverse of the radius-of-curvature of lens surface, K is the circular cone coefficient, A, B, C, D, E, F, G and H are the high-order asphericity coefficient, and the face shape parameter of the front surface of first, second and third lens and rear surface is followed successively by shown in table 1, table 2, table 3, table 4, table 5 and the table 6:
And described mid-diaphragm is arranged between described first lens and the second lens, described glass filter along object space to the image aspect rear in described the 3rd lens, the scope of the center thickness of described first lens is 0.55-0.65mm, the scope of the center thickness of described the second lens is 0.4-0.5m, and the scope of the center thickness of described the 3rd lens is 0.6-0.7mm.
Preferably, described glass filter is one.
Preferably, the scope of the refractive index of described first lens is 1.4-1.6, and the scope of the abbe number of described first lens is 50-64.
Preferably, the scope of the refractive index of described the second lens is 1.6-1.7, and the scope of the abbe number of described the second lens is 20-30.
Preferably, the scope of the refractive index of described the 3rd lens is 1.4-1.6, and the scope of the abbe number of described the 3rd lens is 50-64.
Preferably, the front surface of described first lens is protruding convex surface to object space, and the rear surface of described first lens is recessed concave surface to picture side.
Preferably, the lower end is the plane on the front surface of described the second lens, and the center of the front surface of described the second lens is recessed to object space, and position male is to the convex surface of picture side centered by the rear surface of described the second lens.
Preferably, the front surface of described the 3rd lens is upper and lower side and rises and falls and the protruding setting to object space in center, and the rear surface of described the 3rd lens is upper and lower side and rises and falls and the recessed setting to picture side in center.
Preferably, the scope of the optics overall length of described optical lens assembly is 3.7-3.8mm.
Compared with prior art, beneficial effect after the employing technique scheme is embodied in: the lens combination in the utility model optical lens assembly has three lens, relatively there is the optical lens assembly of the lens combination of four lens to have advantage on the volume, and each lens all adopt non-spherical structure, can effectively shorten the overall length of camera lens, make this overall length less than 3.8 millimeters, field angle is greater than 66 degree; Simultaneously, adopt aspheric lens can effectively eliminate the various aberrations of light, improve image quality, improve imaging effect; In addition, the utility model optical lens assembly also has the low and high advantage of production efficiency of cost.
By following description also by reference to the accompanying drawings, it is more clear that the utility model will become, and these accompanying drawings are used for explaining embodiment of the present utility model.
Description of drawings
Fig. 1 is the structural representation of optical lens assembly of the present utility model.
Fig. 2 is the modulated optical transport function figure of optical lens assembly of the present utility model.
Fig. 3 is the curvature of field synoptic diagram of optical lens assembly of the present utility model.
Fig. 4 is the distortion synoptic diagram of optical lens assembly of the present utility model.
Embodiment
Below in conjunction with the accompanying drawing among the utility model embodiment, the technical scheme among the embodiment is clearly and completely described, obviously, described embodiment only is the utility model part embodiment, rather than whole embodiment.Based on the embodiment in the utility model, those of ordinary skills are not making the every other embodiment that obtains under the creative work prerequisite, all belong to the scope of the utility model protection.
See also Fig. 1, optical lens assembly of the present utility model 100 is more excellent to be to be applied to comprise mid-diaphragm 10, lens combination 20 and glass filter 30 in the camera module of 1/4 inch specification 5,000,000 pixel of mobile communications tool.Lens combination 20 comprises first lens 21, the second lens 22 and the 3rd lens 23 that arrange with optical axis, this first lens 21, the second lens 22 and the 3rd lens 23 are more excellent to be by the made lens of optical plastic, with the weight that alleviates camera lens, reduce manufacturing cost and enhance productivity; Specifically, the material of first lens 21 and the 3rd lens 23 is optical plastic E48R(cyclic olefin based polymer), the material of the second lens 22 is the armorphous olefin polymer of optical plastic OKP4HT(); And first lens 21, the second lens 22 and the 3rd lens 23 set gradually to picture side 40 along object space, and the surface of first lens 21, the second lens 22 and the 3rd lens 23 is aspheric surface, and this aspheric surface formula is:
Wherein, Z represents the Z coordinate figure of each point on the lens surface, Y represents the Y-axis coordinate figure of each point on the lens surface, CURV is the inverse of the radius-of-curvature of lens surface, K is the circular cone coefficient, and A, B, C, D, E, F, G and H are the high-order asphericity coefficient, the front surface 211 of first lens 21 and rear surface 212, the front surface 221 of the second lens 22 and rear surface 222, and the face shape parameter of the front surface 231 of the 3rd lens 23 and rear surface 232 is followed successively by shown in table 1, table 2, table 3, table 4, table 5 and the table 6:
Wherein, mid-diaphragm 10 is between first lens 21 and the second lens 22, and glass filter 30 is positioned at the rear (be the imaging surface of optical lens assembly 100 of the present utility model before) of the 3rd lens 23 along object space to picture side 40; And the scope of the center thickness of first lens 21 is 0.55-0.65mm, and the scope of the center thickness of the second lens 22 is 0.4-0.5mm, and the scope of the center thickness of the 3rd lens 23 is 0.6-0.7mm.More excellent is that the center thickness of first lens 21 can be 0.55,0.602 or 0.65 millimeter, is preferably 0.602 millimeter; The center thickness of the second lens 22 is 0.4,0.451 or 0.5 millimeter, is preferably 0.451 millimeter; The center thickness of the 3rd lens 23 is 0.6,0.649 or 0.7 millimeter, is preferably 0.649 millimeter.Particularly, in the present embodiment, the scope of the optics overall length of optical lens assembly 100 of the present utility model is 3.7mm-3.8mm, is applied to the optics overall length of the optical lens assembly 100 in the CCD camera assembly of 1/4 inch specification 5,000,000 pixel of mobile communications tool with reduction.More specifically, as follows:
Than the superior, glass filter 30 be one to simplify the structure of optical lens assembly 100 of the present utility model; Particularly, the material of this glass filter 30 is optical glass Xiao Te D263T.
Simultaneously, the scope of the refractive index of first lens 21 is 1.4-1.6, and the scope of the abbe number of first lens 21 is 50-64; Preferably, the refractive index of first lens 21 is 1.4,1.53 or 1.6, be preferably 1.53, and the abbe number of first lens 21 is 50,55.8 or 64, is preferably 55.8.Particularly, in the present embodiment, the front surface 211 of first lens 21 is protruding convex surface to object space, the rear surface 212 of first lens 21 be recessed to picture side 40 concave surface.
Moreover the scope of the refractive index of the second lens 22 is 1.6-1.7, and the scope of the abbe number of the second lens 22 is 20-30; Preferably, the refractive index of the second lens 22 is 1.6,1.63 or 1.7, and the abbe number that is preferably 1.63, the second lens 22 is 20,23.4 or 30, is preferably 23.4.Particularly, in the present embodiment, the lower end is the plane on the front surface 221 of the second lens 22, and the center of the front surface 221 of the second lens 22 is recessed to object space, centered by the rear surface 222 of the second lens 22 position male to picture side 40 convex surface.
At last, the scope of the refractive index of the 3rd lens 23 is 1.4-1.6, and the scope of the abbe number of the 3rd lens 23 is 50-64; Preferably, the refractive index of the 3rd lens 23 is 1.4,1.53 or 1.6, and the abbe number that is preferably 1.53, the three lens 23 is 50,55.8 or 64, is preferably 55.8.Particularly, in the present embodiment, the front surface 231 of the 3rd lens 23 is that upper and lower side rises and falls and the protruding setting to object space in center, and the rear surface 232 of the 3rd lens 23 is that upper and lower side rises and falls and recessed 40 the setting to picture side in center.
So, the effective focal length of optical lens assembly 100 of the present utility model is 3.26 millimeters, back focal length is 0.7 millimeter, the optics overall length is less than 3.8 millimeters, relative aperture F/NO(aperture numerical value) be 2.9, field angle is spent greater than 66, and various aberrations are well corrected, and obtains desirable optical property.The camera height of using optical lens assembly 100 of the present utility model can be less than 4.6 millimeters, for the exploitation of the shooting mobile phone of ultra-thin and high pixel provides solution.
Fig. 2 is modulation transfer function (ModulationTransfer Function the is called for short MTF) curve map of the utility model optical lens assembly, horizontal ordinate representation space frequency among the figure, and unit: line is to every millimeter (lp/mm); Ordinate represents the value of modulation transfer function (MTF), the value of described MTF is used for estimating the imaging clearly situation of optical lens assembly 100 of the present utility model, span is that the imaging of the higher representative shot of 0~1, MTF curve is more clear, and is stronger to the reducing power of image.As can be seen from Figure 2, the MTF curve that each visual field meridian direction (T) and arc lose direction (S) is very intensive, and it represents that this lens assembly has good consistance at whole imaging surface, can clearly imaging on whole imaging surface.
Fig. 3 and Fig. 4 are respectively the curvature of field and the distortion figure of the utility model optical lens assembly, can find out from Fig. 3 and Fig. 4, the curvature of field of this optical lens assembly is less than 0.1 millimeter, distortion is less than 1.0%, can satisfying the market on the requirement of complementary metal oxide semiconductor (CMOS) (CMOS) or Charge Coupled Device (CCD) (CCD) image sensor.
Compared with prior art, beneficial effect after the employing technique scheme is embodied in: the lens combination 20 in the utility model optical lens assembly 100 has three lens, relatively there is the optical lens assembly of the lens combination of four lens to have advantage on the volume, and each lens all adopt non-spherical structure, can effectively shorten the overall length of camera lens, make this overall length less than 3.8 millimeters, field angle is greater than 66 degree; Simultaneously, adopt aspheric lens can effectively eliminate the various aberrations of light, improve image quality, improve imaging effect; In addition, the utility model optical lens assembly 100 also has the low and high advantage of production efficiency of cost.
Abovely in conjunction with most preferred embodiment the utility model is described, but the utility model is not limited to the embodiment of above announcement, and should contains various modification, equivalent combinations of carrying out according to essence of the present utility model.