CN102854611A

CN102854611A - Microminiature imaging lens

Info

Publication number: CN102854611A
Application number: CN2012100615647A
Authority: CN
Inventors: 陈俊宏
Original assignee: Asia Optical Co Inc
Current assignee: Asia Optical Co Inc
Priority date: 2011-06-29
Filing date: 2012-03-09
Publication date: 2013-01-02
Anticipated expiration: 2032-03-09
Also published as: CN102854611B

Abstract

The invention relates to a microminiature imaging lens. The microminiature imaging lens comprises a first lens, a second lens, a third lens, an aperture, a fourth lens and a fifth lens which are sequentially arranged from an object side to an image side along an optical axis, wherein the first lens is a crescent lens with negative refractive power, the convex side of the first lens faces towards the object side, at least one surface of the first lens is an aspheric surface, the second lens is a biconvex lens with positive refractive power, the third lens is a biconcave lens with the negative refractive power, the fourth lens is a biconvex lens with the positive refractive power, at least one surface of the fourth lens is the aspheric surface, and the fifth lens is a lens with the negative refractive power. By means of the lenses, the microminiature imaging lens has the advantages that the miniaturization and high optical efficiency can be achieved.

Description

The microminiature imaging lens

Technical field

The present invention is relevant with optical devices, in more detail refers to a kind of microminiature imaging lens.

Background technology

In recent years, along with the progress of science and technology, such as image capture units such as camera, video camera, microscope or scanners, for being convenient for people to carry and use, and tend to gradually miniaturization and lightweight, this will so that the volume of the used imaging lens of image capture unit also therefore significantly dwindled.In addition, except miniaturization and lightweight, also want to have higher optical performance, just can make and reach representing of high resolving power and high contrast.Therefore, miniaturization and high optical performance are indispensable two important documents of imaging lens.

Yet the imaging lens that present image capture unit adopts for reaching the purpose of high optical performance, nothing more than the mirror group who has used many groups, even has the eyeglass sum total more than ten above persons.In addition, also promisingly reach the purpose that makes the imaging lens miniaturization, and only use several pieces eyeglasses, but so that its optical performance can't effectively promote.

Comprehensive the above, known imaging lens is not detectd perfect yet, and the part that still haves much room for improvement.

Summary of the invention

The technical problem to be solved in the present invention is, can't satisfy simultaneously the defective of miniaturization and high optical performance for imaging lens of the prior art, and a kind of microminiature imaging lens is provided, and not only volume is little and have a high optical performance.

The present invention is that the technical scheme that its technical matters of solution adopts is, a kind of microminiature imaging lens is provided, include along optical axis and by the thing side to the first eyeglass, the second eyeglass, prismatic glasses, aperture, the 4th eyeglass and the 5th eyeglass sequentially arranged as side.Wherein, this first eyeglass is the meniscus eyeglass with negative refractive power, and its convex surface is towards this thing side, and one side is non-spherical surface at least; This second eyeglass is the biconvex eyeglass with positive refractive power; This prismatic glasses is the concave-concave eyeglass with negative refractive power; The 4th eyeglass is the biconvex eyeglass with positive refractive power, and one side is non-spherical surface at least; The 5th eyeglass is the eyeglass with negative refractive power.

By this, utilize the configuration of above-mentioned eyeglass and aperture and reach the purpose of miniaturization and high optical performance.

Description of drawings

Fig. 1 is the eyeglass arrangement plan of the present invention's the first preferred embodiment.

Fig. 2 is the index path of the present invention's the first preferred embodiment.

Fig. 3 A is curvature of field figure and the distortion figure of the present invention's the first preferred embodiment.

Fig. 3 B is the lateral light fan figure of the present invention's the first preferred embodiment.

Fig. 3 C is the out of focus modulation transfer function figure of the present invention's the first preferred embodiment.

Fig. 3 D is the Space Frequency Modulation transport function figure of the present invention's the first preferred embodiment.

Fig. 4 is the eyeglass arrangement plan of the present invention's the second preferred embodiment.

Fig. 5 is the index path of the present invention's the second preferred embodiment.

Fig. 6 A is curvature of field figure and the distortion figure of the present invention's the second preferred embodiment.

Fig. 6 B is the lateral light fan figure of the present invention's the second preferred embodiment.

Fig. 6 C is the out of focus modulation transfer function figure of the present invention's the second preferred embodiment.

Fig. 6 D is the Space Frequency Modulation transport function figure of the present invention's the second preferred embodiment.

Fig. 7 is the eyeglass arrangement plan of the present invention's the 3rd preferred embodiment.

Fig. 8 is the index path of the present invention's the 3rd preferred embodiment.

Fig. 9 A is curvature of field figure and the distortion figure of the present invention's the 3rd preferred embodiment.

Fig. 9 B is the lateral light fan figure of the present invention's the 3rd preferred embodiment.

Fig. 9 C is the out of focus modulation transfer function figure of the present invention's the 3rd preferred embodiment.

Fig. 9 D is the Space Frequency Modulation transport function figure of the present invention's the 3rd preferred embodiment.

Embodiment

For being illustrated more clearly in the present invention, hereby lifting preferred embodiment and cooperate accompanying drawing to be described in detail as follows.

See also Fig. 1, be the eyeglass arrangement plan of the microminiature imaging lens 1 of the present invention's the first preferred embodiment.Fig. 2 is index path embodiment illustrated in fig. 1.Cooperate Fig. 1 and Fig. 2, below will describe the microminiature imaging lens 1 of first embodiment of the invention in detail.

This microminiature imaging lens 1 include along optical axis Z and by the thing side to the first eyeglass L1, the second eyeglass L2, prismatic glasses L3, aperture ST, the 4th eyeglass L4 and the 5th eyeglass L5 that sequentially arrange as side.In addition, the demand according on using optionally arranges optical filter CF between the 5th eyeglass L5 and imaging plane IP (Image Plane), be sheet glass.Wherein:

L1 is made by glass material for this first eyeglass, and is a meniscus eyeglass with negative refractive power, and its convex surface is towards the thing side.In addition, convex surface S1 and the concave surface S2 of this first eyeglass L1 are all non-spherical surface.

L2 is made by glass material for this second eyeglass, and is a biconvex eyeglass with positive refractive power.This prismatic glasses L3 is made by glass material, and is a concave-concave eyeglass with negative refractive power.In addition, this second eyeglass L2 and this prismatic glasses L3 gluing form the gummed eyeglass L23 with positive refractive power.

The 4th eyeglass L4 is made by glass material, and is a biconvex eyeglass with positive refractive power.In addition, two of the 4th eyeglass L4 convex surface S8, S9 are all non-spherical surface.

The 5th eyeglass L5 is made by glass material, and is a meniscus eyeglass with negative refractive power, and its convex surface S11 is towards the picture side.

And in the configuration of the eyeglass of above-mentioned microminiature imaging lens 1, the aspheric surface design of the negative refractive power characteristic of this first eyeglass L1, the positive refractive power characteristic of the 4th eyeglass L4 and this two eyeglass L1, L4, can make this microminiature imaging lens 1 have better imaging effect, and can effectively shorten the camera lens overall length, more can make this microminiature imaging lens 1 obtain larger angle of visibility (Field of View Angle, FOV).

The optical axis Z of the focal length F of the microminiature imaging lens 1 of first embodiment of the invention (Focus Length), numerical aperture Fno (F-number), each lens surface is by radius of curvature R (radius of curvature), thickness T (thickness), the refractive index Nd (refractive index) of each eyeglass and the Abbe coefficient Vd (Abbe number) of each eyeglass of each eyeglass on optical axis Z at place, as shown in Table 1:

Table one

In each eyeglass of the present embodiment, the surface depression degree z of these non-spherical surfaces S1, S2, S8 and S9 is resulting by following formula:

z = \frac{{ch}^{2}}{1 + {[1 - (k + 1) c^{2} h^{2}]}^{\frac{1}{2}}} + {Ah}^{4} + {Bh}^{6} + {Ch}^{8} + {Dh}^{10} + {Eh}^{12} + {Fh}^{14} + {Gh}^{16}

Wherein:

Z: the depression degree of non-spherical surface;

C: the inverse of radius-of-curvature;

H: the aperture radius on surface;

K: circular cone coefficient;

A～G: each rank coefficient of the aperture radius h on surface.

In the present embodiment, each rank coefficient A～G of the circular cone coefficient k of each non-spherical surface (conic constant) and surface apertures radius h is as shown in Table 2:

Table two

By above-mentioned eyeglass and aperture ST configuration so that the microminiature imaging lens 1 of the present embodiment not only effectively reduced volume on image quality, also can reach requirement to meet the demand of miniaturization, this can find out from Fig. 3 A to Fig. 3 D.

Shown in Fig. 3 A, be curvature of field figure and the distortion figure of the microminiature imaging lens 1 of the present embodiment; Shown in Fig. 3 B, be the lateral light fan figure of the microminiature imaging lens 1 of the present embodiment; Shown in Fig. 3 C, be the out of focus modulation transfer function figure (Through Focus MTF) of the microminiature imaging lens 1 of the present embodiment; Shown in Fig. 3 D, be the Space Frequency Modulation transport function figure (Spatial Frequency MTF) of the microminiature imaging lens 1 of the present embodiment.

Can find out from Fig. 3 A, the maximum curvature of field of the present embodiment be no more than 0.1mm and-0.1mm, amount of distortion is no more than 0.6%.Can find out from Fig. 3 B and Fig. 3 C, the present embodiment all has good resolution in which field positions.From Fig. 3 D as can be known, the present embodiment is the time marquis of 48lp/mm, and its modulated optical transfer function values still maintains more than 60%, and the resolution of the microminiature imaging lens 1 of obvious the present embodiment is standard compliant.

Above-described, be the microminiature imaging lens 1 of first embodiment of the invention; According to technology of the present invention, below cooperate Fig. 4 and Fig. 5 that the second embodiment of the present invention is described.

With the first embodiment in the same manner, the microminiature imaging lens 2 of second embodiment of the invention includes the first eyeglass L1, the second eyeglass L2, prismatic glasses L3, aperture ST, the 4th eyeglass L4 and the 5th eyeglass L5 that extremely looks like side and arrange along optical axis Z from the thing side, and is provided with equally the optical filter CF of sheet glass between the 5th eyeglass L5 and imaging plane IP.Wherein:

L1 is made by glass material for this first eyeglass, and is a meniscus eyeglass with negative refractive power, and its convex surface S1 is towards the thing side.In addition, convex surface S1 and the concave surface S2 of this first eyeglass L1 are all non-spherical surface.

And in the configuration of above-mentioned eyeglass, the wherein aspheric surface of the positive refractive power characteristic of the negative refractive power characteristic of this first eyeglass L1, the 4th eyeglass L4 and this two eyeglass L1, L4 design, can make equally this microminiature imaging lens 2 have better imaging effect, effectively shorten the camera lens overall length and make this microminiature imaging lens 2 obtain larger angle of visibility (Field of View Angle, FOV).

The optical axis Z of the focal length F of the microminiature imaging lens 2 of second embodiment of the invention (Focus Length), numerical aperture Fno (F-number), each lens surface is by radius of curvature R (radius of curvature), thickness T (thickness), the refractive index Nd (refractive index) of each eyeglass and the Abbe coefficient Vd (Abbe number) of each eyeglass of each eyeglass on optical axis Z at place, as shown in Table 3:

Table three

z = \frac{{ch}^{2}}{1 + {[1 - (k + 1) c^{2} h^{2}]}^{\frac{1}{2}}} + {Ah}^{4} + {Bh}^{6} + {Ch}^{8} + {Dh}^{10} + {Eh}^{12} + {Fh}^{14} + {Gh}^{16}

Wherein:

Z: the depression degree of non-spherical surface;

C: the inverse of radius-of-curvature;

H: the aperture radius on surface;

K: circular cone coefficient;

A～G: each rank coefficient of the aperture radius h on surface.

In the present embodiment, each rank coefficient A～G of the circular cone coefficient k of each non-spherical surface (conic constant) and surface apertures radius h is as shown in Table 4:

Table four

By above-mentioned eyeglass and aperture ST configuration so that the microminiature imaging lens 2 of the present embodiment not only effectively reduced volume on image quality, also can reach requirement to reach the demand of miniaturization, this can find out from Fig. 6 A to Fig. 6 D.

Shown in Fig. 6 A, be curvature of field figure and the distortion figure of the microminiature imaging lens 2 of the present embodiment; Shown in Fig. 6 B, be the lateral light fan figure of the microminiature imaging lens 2 of the present embodiment; Shown in Fig. 6 C, be the out of focus modulation transfer function figure (Through Focus MTF) of the microminiature imaging lens 2 of the present embodiment; Shown in Fig. 6 D, be the Space Frequency Modulation transport function figure (Spatial Frequency MTF) of the microminiature imaging lens 2 of the present embodiment.

Can find out from Fig. 6 A, the maximum curvature of field of the present embodiment be no more than 0.1mm and-0.1mm, amount of distortion is no more than 0.6%.Can find out from Fig. 6 B and Fig. 6 C, the present embodiment all has good resolution in which field positions.From Fig. 6 D as can be known, the present embodiment is the time marquis of 48lp/mm, and its modulated optical transfer function values still maintains more than 50%, and the resolution of the microminiature imaging lens 2 of obvious the present embodiment is standard compliant.

See also Fig. 7 and Fig. 8, be eyeglass configuration and the index path of the microminiature imaging lens 3 of the present invention's the 3rd preferred embodiment.This microminiature imaging lens 3 includes the first eyeglass L1, the second eyeglass L2, prismatic glasses L3, aperture ST, the 4th eyeglass L4 and the 5th eyeglass L5 that extremely looks like side and arrange along optical axis Z from the thing side equally, and is provided with equally the optical filter CF of sheet glass between the 5th eyeglass L5 and imaging plane IP.Wherein:

L2 is made by glass material for this second eyeglass, and is a biconvex eyeglass with positive refractive power.This prismatic glasses L3 is made by glass material, and is a concave-concave eyeglass with negative refractive power.In addition, this second eyeglass L2 and this prismatic glasses L3 gluing form the gummed eyeglass L23 with negative refractive power.

The 5th eyeglass L5 is made by glass material, and is a concave-concave eyeglass with negative refractive power.

And in the configuration of above-mentioned eyeglass, the wherein aspheric surface of the positive refractive power characteristic of the negative refractive power characteristic of this first eyeglass L1, the 4th eyeglass L4 and this two eyeglass L1, L4 design, can make equally this microminiature imaging lens 3 have better imaging effect, effectively shorten the camera lens overall length and make this microminiature imaging lens 3 obtain larger angle of visibility (Field of ViewAngle, FOV).

The optical axis Z of the focal length F of the microminiature imaging lens 3 of third embodiment of the invention (Focus Length), numerical aperture Fno (F-number), each lens surface is by radius of curvature R (radius of curvature), thickness T (thickness), the refractive index Nd (refractive index) of each eyeglass and the Abbe coefficient Vd (Abbe number) of each eyeglass of each eyeglass on optical axis Z at place, as shown in Table 5:

Table five

z = \frac{{ch}^{2}}{1 + {[1 - (k + 1) c^{2} h^{2}]}^{\frac{1}{2}}} + {Ah}^{4} + {Bh}^{6} + {Ch}^{8} + {Dh}^{10} + {Eh}^{12} + {Fh}^{14} + {Gh}^{16}

Wherein:

Z: the depression degree of non-spherical surface;

C: the inverse of radius-of-curvature;

H: the aperture radius on surface;

K: circular cone coefficient;

A～G: each rank coefficient of the aperture radius h on surface.

In the present embodiment, each rank coefficient A～G of the circular cone coefficient k of each non-spherical surface (conic constant) and surface apertures radius h is as shown in Table 6:

Table six

By above-mentioned eyeglass and aperture ST configuration so that the microminiature imaging lens 3 of the present embodiment not only effectively reduced volume on image quality, also can reach requirement to reach the demand of miniaturization, this can find out from Fig. 9 A to Fig. 9 D.

Shown in Fig. 9 A, be curvature of field figure and the distortion figure of the microminiature imaging lens 3 of the present embodiment; Shown in Fig. 9 B, be the lateral light fan figure of the microminiature imaging lens 3 of the present embodiment; Shown in Fig. 9 C, be the out of focus modulation transfer function figure (Through Focus MTF) of the microminiature imaging lens 3 of the present embodiment; Shown in Fig. 9 D, be the Space Frequency Modulation transport function figure (Spatial Frequency MTF) of the microminiature imaging lens 3 of the present embodiment.

Can find out from Fig. 9 A, the maximum curvature of field of the present embodiment be no more than 0.1mm and-0.1mm, amount of distortion is no more than 0.6%.Can find out from Fig. 9 B and Fig. 9 C, the present embodiment all has good resolution in which field positions.From Fig. 9 D as can be known, the present embodiment is the time marquis of 48lp/mm, and its modulated optical transfer function values still maintains more than 50%, and the resolution of the microminiature imaging lens of obvious the present embodiment is standard compliant.

Not only reduced volume and while can have high optical performance effectively for comprehensive above can learning, microminiature imaging lens of the present invention.

The above only is the better possible embodiments of the present invention, and the equivalent structure that all application instructions of the present invention and claim are done and method for making change, and ought to be included in the claim of the present invention.

Claims

1. a microminiature imaging lens is characterized in that, include along optical axis and by the thing side to sequentially arranging as side:

The first eyeglass, for having the meniscus eyeglass of negative refractive power, its convex surface is towards this thing side, and one side is non-spherical surface at least;

The second eyeglass is for having the biconvex eyeglass of positive refractive power;

Prismatic glasses is for having the concave-concave eyeglass of negative refractive power;

Aperture;

The 4th eyeglass, for having the biconvex eyeglass of positive refractive power, and one side is non-spherical surface at least;

The 5th eyeglass is for having the eyeglass of negative refractive power.

2. microminiature imaging lens as claimed in claim 1 is characterized in that, this first eyeglass, this second eyeglass, this prismatic glasses, the 4th eyeglass and the 5th eyeglass are all made by glass material.

3. microminiature imaging lens as claimed in claim 1 is characterized in that, concave surface and the convex surface of this first eyeglass are all non-spherical surface.

4. microminiature imaging lens as claimed in claim 1 is characterized in that, two convex surfaces of the 4th eyeglass are all non-spherical surface.

5. microminiature imaging lens as claimed in claim 1 is characterized in that, this second eyeglass and this prismatic glasses gluing form the gummed eyeglass, and this gummed eyeglass has positive refractive power.

6. microminiature imaging lens as claimed in claim 1 is characterized in that, this second eyeglass and this prismatic glasses gluing form the gummed eyeglass, and this gummed eyeglass has negative refractive power.

7. microminiature imaging lens as claimed in claim 1 is characterized in that, more comprises optical filter, between the 5th eyeglass and this are as side, and is sheet glass.

8. microminiature imaging lens as claimed in claim 1 is characterized in that, the 5th eyeglass is crescent eyeglass, and its convex surface towards this as side.

9. microminiature imaging lens as claimed in claim 1 is characterized in that, the 5th eyeglass is the concave-concave eyeglass.