CN201083875Y - Micro-optical lens - Google Patents

Abstract

The utility model discloses a micro optical lens, which is suitable for mobile phones and thin typed digital cameras, etc. The lens comprises a first lens close to positive refractive power of an object space and the second lens closes to negative refractive power of an image space; the first lens is a crescentiform lens which has the structure of a concave surface facing the object space and a convex surface facing the imaging surface, and at least one surface of the two surfaces of the first lens is aspheric; the second lens is a crescentiform lens which has the structure of a convex surface facing the object space and a concave surface facing the imaging surface, and at least one surface of the two surfaces of the second lens is aspheric; a lens diaphragm is arranged at the front end of the first lens, and the lens has a symmetric structure, which can effectively correct various aberrations and have a compact structure; the forward diaphragm has relative large diameter of 1/2.2 to 1/2.4,which improves the relative brightness of image surface, and achieves more satisfactory imaging effect.

Description

Minisize optical lens

Technical field

The utility model relates to a kind of minisize optical lens, mainly is the shooting image-taking device that is applied to mobile phone, mobile PC and other use CCD or CMOS sensor devices.

Background technology

Progress along with science and technology, digital camera is taken the function of memory image, be widely used on the electronic products such as mobile phone, mobile PC, PDA, the image-taking device of these product correspondences not only has good imaging performance, also require compact, be easy to large-scale production and lower cost.The camera lens of present this type of image-taking device, basic aspheric surface glass lens or the aspheric surface modeling glass lens of adopting, minority adopts plastic aspherical element eyeglass and glass sphere or aspherical lens to constitute, this not only can obtain image quality preferably, and make that the camera lens volume size is less, as following Chinese patent literature number is CN1880997A " sampling image lens group ", " optical shooting lens " of CN2603407Y etc., disclosed minisize optical lens is by two, three or four plastics or glass moulding eyeglass constitute, volume size is all smaller, can both satisfy the use on mobile phone etc.But because the imaging performance of optical lens also has confidential relation with its relative aperture (D/f), major control enter camera lens light ray energy what, the relative brightness of decision image planes, and the relative aperture of above-mentioned these camera lenses is generally all between 1/2.8～1/3.5, be difficult to further raising, otherwise will reduce the aspect performances such as resolving power of camera lens, therefore can't satisfy the requirement high image planes brightness.

Summary of the invention

Goal of the invention of the present utility model is to overcome the defective of prior art and provides that a kind of imaging performance is better, to make assembling simpler and be easier to the minisize optical lens of large-scale production.

Goal of the invention of the present utility model realizes by following technical proposal:

A kind of minisize optical lens comprises first eyeglass near the positive light coke of object space, near second eyeglass of the negative power of picture side, and the camera lens diaphragm is located at the first eyeglass front end, and having at least simultaneously in two faces of described first eyeglass is aspheric surface; Having one side in two faces of described second eyeglass at least is aspheric surface, it is characterized in that:

The meniscus eyeglass that the convex surface that a, described first eyeglass are faced imaging surface for the concave surface in the face of object space reaches constitutes;

The meniscus eyeglass that the concave surface that b, described second eyeglass are faced imaging surface for the convex surface in the face of object space reaches constitutes;

Satisfy following relation between c, described diaphragm, first eyeglass and second eyeglass:

1＜R1/R2＜12

1＜R3/R4＜10

0.8f＜f1＜1f 2.8f＜-f2＜3.2f

0.41f＜D＜0.46f

1.5＜D/L＜4

In the formula: f is a lens focus,

F1 is the first eyeglass focal length,

F2 is the second eyeglass focal length,

R1 is the radius-of-curvature of first eyeglass towards object space,

R2 is the radius-of-curvature of first eyeglass towards picture side,

R3 is the radius-of-curvature of second eyeglass towards object space,

R4 is the radius-of-curvature of second eyeglass towards picture side,

D is the camera lens diaphragm diameter,

L is the distance of camera lens diaphragm to the first eyeglass object space concave surface summit.

Compared with prior art, the utility model adopts two aspherical lens of positive negative power, first eyeglass is recessed meniscus positive lens to object space, second eyeglass is recessed meniscus negative lens to picture side, and two lens structures are arranged in opposite directions, again eyeglass aspheric surface function in addition, can effectively correct the various aberrations of camera lens, reduce the susceptibility of camera lens tolerance, make camera lens have bigger relative aperture, improved the relative brightness of image planes; The camera lens aperture of the diaphragm is preposition, help to reduce the size of system's chief ray emergence angle, be easy to the sensitive chip coupling, help to reduce the length of camera lens light path, and two eyeglasses all adopt plastic material, help to eliminate aberration and reduce camera lens weight, it is little not only can to satisfy the camera lens small product size, lightweight development trend requirement, and have higher resolving power and bigger relative aperture, relative aperture can reach 1/2.2～1/2.4, has improved the relative brightness of image planes, obtains more gratifying imaging effect, make the manufacturing assembling simpler, be easier to large-scale production, improved the range of application of minisize optical lens.

Description of drawings

Fig. 1 is the utility model optical texture synoptic diagram.

Fig. 2 is the light path synoptic diagram of the utility model first embodiment.

Fig. 3 is the MTF synoptic diagram of the utility model first embodiment.

Fig. 4 is the light path synoptic diagram of the utility model second embodiment.

Fig. 5 is the MTF synoptic diagram of the utility model second embodiment.

Embodiment

Embodiment is described in detail the utility model again below with reference to accompanying drawing.

Please refer to shown in Figure 1ly, minisize optical lens of the present utility model promptly is fixed with camera lens diaphragm 5, first eyeglass 1, second eyeglass 2, color filter 3 and sensitive chip 4 by lens barrel and spacer ring successively in lens barrel.Light by behind first eyeglass 1 and second eyeglass 2, images on the sensitive chip 4 by color filter 3 successively through camera lens diaphragm 5 apertures of the first eyeglass front end again, obtains good imaging.Wherein, first eyeglass 1 is by in the face of the concave surface of object space and in the face of the meniscus eyeglass of the convex surface structure of imaging surface, and to have one side at least in two faces be aspheric surface; Second eyeglass 2 is by in the face of the convex surface of object space and in the face of the meniscus eyeglass of the concave configuration of imaging surface, and to have a face at least in two faces be aspheric surface, and camera lens diaphragm 5 is located at the first eyeglass front end.Satisfy following relational expression between described camera lens diaphragm and two eyeglasses:

1＜R1/R2＜12

1＜R3/R4＜10

0.8f＜f1＜1f 2.8f＜-f2＜3.2f

0.41f＜D＜0.46f

1.5＜D/L＜4

Wherein f is a lens focus, f1 is the focal length of first eyeglass, f2 is the focal length of second eyeglass, R1 is the radius-of-curvature of first eyeglass towards object space, R2 is the radius-of-curvature of first eyeglass towards picture side, and R3 is the radius-of-curvature of second eyeglass towards object space, and R4 is the radius-of-curvature of second eyeglass towards picture side, D is camera lens diaphragm diameter (also being camera lens entrance pupil diameter), and L is the distance of camera lens diaphragm to the first eyeglass object space concave surface summit.

When minisize optical lens of the present utility model satisfies relational expression:

1＜R1/R2＜12

1＜R3/R4＜10

0.8f＜f1＜1f 2.8f＜-f2＜3.2f

The time, the lens construction symmetric offset spread, lens length and lens focus are approaching, satisfy the compact requirement of camera lens.

When minisize optical lens of the present utility model satisfies relational expression:

0.41f＜D＜0.46f

1.5＜D/L＜4

The time, the camera lens diaphragm is positioned at the first eyeglass front end, can make the exit pupil position of optical system elongated, and the relative aperture of system is bigger, can reach 1/2.2～1/2.4.When D/L＜1.5, the aperture of the diaphragm is far away from first eyeglass distance, be unfavorable for correcting off-axis aberration, and when 4＜D/L, the aperture of the diaphragm is that concave surface is too near from first face of first eyeglass, owing to the influence of the first eyeglass concave, actual can't process and assemble.

Be listed as for two example two below, concrete implementation is as follows:

First embodiment

Please refer to Fig. 2, shown in Figure 3, be respectively optical beam path figure, the MTF synoptic diagram of present embodiment; About

Each lens parameters of the minisize optical lens of present embodiment, enumerate as follows:

	Radius-of-curvature	Thickness	Material refractive index Abbe number
				Object object	∞	∞
Diaphragm stop		0.1
				First on R1 first eyeglass	-5.63	0.74	Nd＝1.543402 Vd＝56.004
Second on R2 first eyeglass	-0.72	0.06
				First on R3 second eyeglass	1.0861	0.4	Nd＝1.543402 Vd＝56.004
Second on R4 second eyeglass	0.661	0.35
				First of color filter	∞	0.4	BK7
Second of color filter	∞	0
				Image planes image	∞	0

Asphericity coefficient such as following table:

	R1	R2	R3	R4
					K	64.335	-0.428434	-18.82572	-0.697954
A	-1.161814	-0.619597	0.326744	-0.636034
					B	10.606909	2.893493	-0.982031	0.107026
C	-93.891016	-8.503237	2.0030058	3.545725
					D	116.97175	6.650302	-2.166829	-10.324019
E	762.959795	2.456694	1.87544	10.475179

The aspheric surface formulate is:

$Z=\frac{{\mathrm{<figure-callout\; id="2"\; label="cr"\; filenames="S200720114353XE00011.png,S200720114353XE00021.png"\; state="\{\{state\}\}">cr</figure-callout>}}^2}{1+{[1-(k+1)c^2{r}^2]}^{1/2}}+{\mathrm{<figure-callout\; id="4"\; label="Br"\; filenames="S200720114353XE00011.png,S200720114353XE00021.png"\; state="\{\{state\}\}">Br</figure-callout>}}^4+{\mathrm{<figure-callout\; id="6"\; label="Cr"\; filenames="S200720114353XE00021.png"\; state="\{\{state\}\}">Cr</figure-callout>}}^6+{\mathrm{Dr}}^8+{\mathrm{Er}}^{10}+{\mathrm{Fr}}^{12}$

Wherein, z highly is being the position of the r shift value with surface vertices optical axis for referencial use along optical axis direction, and k is the constant of the cone, and c is the inverse of radius-of-curvature, and B, C, D, E, F are respectively 4,6,8,10 and 12 rank asphericity coefficients.

First and second lens materials in the present embodiment all is APEL5014 plastic material (cycloolefin copolymerization).

R1/R2=7.82 satisfies 1＜R1/R2＜12;

R3/R4=1.64 satisfies 1＜R3/R4＜10;

F1=1.4427, f=1.6, f2=-4.648, satisfy 0.8f＜f1＜1f 2.8f＜-f2＜3.2f;

D=0.67 satisfies 0.4 1 f＜D＜0.46f;

D/L=3.3 satisfies 1.5＜D/L＜4.

Second embodiment

Please refer to Fig. 4, shown in Figure 5, be respectively optical beam path figure, the MTF synoptic diagram of present embodiment.About each lens parameters of the minisize optical lens of present embodiment, enumerate as follows:

	Radius-of-curvature	Thickness	Material refractive index Abbe number
				Object object	∞	∞
Diaphragm stop		0.11
				First on R1 first eyeglass	-4.5314	0.75	Nd＝1.543402 Vd＝56.004
Second on R2 first eyeglass	-0.7118	0.06
				First on R3 second eyeglass	1.1058	0.42	Nd＝1.58547 Vd＝29.9
Second on R4 second eyeglass	0.6723	0.86
				First of color filter	∞	0.4	BK7
Second of color filter	∞	0
				Image planes image	∞	0

Asphericity coefficient such as following table:

	R1	R2	R3	R4
					K	36.6897	-0.45069	-19.06196	-0.66941
A	-1.077426	-0.59623	0.400529	-0.609623
					B	9.45945	2.928971	-1.106661	-0.080733
C	-95.613352	-8.514069	2.09642	4.109813
					D	241.730395	6.593564	-1.180489	-9.132213
E	164.69351	2.576673	-0.148272	6.4352

The aspheric surface formulate is:

$Z=\frac{{\mathrm{<figure-callout\; id="2"\; label="cr"\; filenames="S200720114353XE00011.png,S200720114353XE00021.png"\; state="\{\{state\}\}">cr</figure-callout>}}^2}{1+{[1-(k+1)c^2{r}^2]}^{1/2}}+{\mathrm{<figure-callout\; id="4"\; label="Br"\; filenames="S200720114353XE00011.png,S200720114353XE00021.png"\; state="\{\{state\}\}">Br</figure-callout>}}^4+{\mathrm{<figure-callout\; id="6"\; label="Cr"\; filenames="S200720114353XE00021.png"\; state="\{\{state\}\}">Cr</figure-callout>}}^6+{\mathrm{Dr}}^8+{\mathrm{Er}}^{10}+{\mathrm{Fr}}^{12}$

Wherein, z highly is being the position of the r shift value with surface vertices optical axis for referencial use along optical axis direction, and k is the constant of the cone, and c is the inverse of radius-of-curvature, and B, C, D, E, F are respectively 4,6,8,10 and 12 rank asphericity coefficients.

First lens materials in the present embodiment is the APEL5014 plastic material, second lens materials is PC (polycarbonate) plastic material, because the Abbe number of PC material is smaller, refractive index is relatively big, the material that in plastic injection-moulded material, belongs to high-refractivity and low-dispersion, and APEL5014 is the material of the high chromatic dispersion of low-refraction, therefore, these two kinds of different materials arranging schemes more help correcting various aberrations, and the camera lens resolving power relatively can be higher.

R1/R2=6.37 satisfies 1＜R1/R2＜12;

R3/R4=1.645 satisfies 1＜R3/R4＜10;

F1=1.4536, f=1.6, f2=-4.576, satisfy 0.8f＜f1＜1f 2.8f＜-f2＜3.2f;

D=0.67 satisfies 0.41f＜D＜0.46f;

D/L=3 satisfies 1.5＜D/L＜4.

Claims (1)

1. minisize optical lens, second eyeglass (2) that comprises the negative power of first eyeglass (1) near the positive light coke of object space, close picture side, camera lens diaphragm (5) is located at the first eyeglass front end, and having one side in two faces of described first eyeglass at least is aspheric surface; Having one side in two faces of described second eyeglass at least is aspheric surface, it is characterized in that:

The meniscus eyeglass that the convex surface that a, described first eyeglass (1) are faced imaging surface for the concave surface in the face of object space reaches constitutes;

The meniscus eyeglass that the concave surface that b, described second eyeglass (2) are faced imaging surface for the convex surface in the face of object space reaches constitutes;

Satisfy following relation between c, described camera lens diaphragm (5), first eyeglass (1) and second eyeglass (2):

1＜R1/R2＜12

1＜R3/R4＜10

0.8f＜f1＜1f 2.8f＜-f2＜3.2f

0.41f＜D＜0.46f

1.5＜D/L＜4

In the formula: f is a lens focus,

F1 is the first eyeglass focal length,

F2 is the second eyeglass focal length,

R1 is the radius-of-curvature of first eyeglass towards object space,

R2 is the radius-of-curvature of first eyeglass towards picture side,

R3 is the radius-of-curvature of second eyeglass towards object space,

R4 is the radius-of-curvature of second eyeglass towards picture side,

D is the camera lens diaphragm diameter,

L is the distance of camera lens diaphragm to the first eyeglass object space concave surface summit.

Images