CN2824074Y - Photographing lens - Google Patents

Abstract

A photographing lens comprises a diaphragm and a lens group from the object side to the image side of the photographing lens, wherein the diaphragm positions on the light entrance surface of the first lens, which is a convex surface and provided with positive refractive power; the light entrance surface of the second lens provided with an aspheric surface is formed by that the part of refractive power contracts gradually which approaches to the direction of the optical axis; the light entrance surface of the third lens is a convex surface and an aspheric surface provided with negative refractive power; the fourth lens is a vitreous filter. The second and the third lens can be made from the resin material. The adoption of the photographing lens of the structure makes the overall length of the lens acquire very fair imaging quality, because the second lens is provided with negative refractive power which makes the center thickness thinner; this structure also makes color-collecting difference smaller and the color saturation after imaging better.

Description

A kind of taking lens

Technical field

This novel a kind of optical lens, particularly a kind of optical lens that is suitable for taking use of relating to.

Background technology

Along with the development of the fast development of modern science and technology, particularly computing machine, communication apparatus, mathematical technique, greatly changed the world of today.The instrument that people are used to make a video recording no longer is traditional optical device, the price of all small and exquisite, convenient with it, light book such as mobile phone, Digital Video, digital camera, PDA and material benefit is more and more liked by people, people also have higher requirement to camera lens, particularly under the requirement of high pixel, high density imaging apparatus, slim camera lens more people is attracted attention.As a Chinese patent application number be: 200310123973.6 case, though satisfied people's request for utilization to a certain extent, it is when satisfying certain quality of optical imaging, and people also wish to make its volume littler, and structure is compact more.

The utility model content

The purpose of this utility model is to design a kind of when satisfying certain quality of optical imaging, shortens taking lens length, makes the taking lens that one-piece construction is compacter, volume is littler.

The utility model adopts structure as follows: extremely include diaphragm, eyeglass as the side from the thing side of taking lens, wherein the plane of light incidence of the 1st eyeglass is convex surface and has positive refractive power, the plane of light incidence of the 3rd eyeglass is a convex surface and for to have the aspheric surface of negative refractive power, the 4th eyeglass is a glass filter.The plane of light incidence of the 2nd eyeglass has aspheric surface and is tending towards the diminishing mode of optical axis direction part refractive power and forms; Diaphragm is positioned on the plane of light incidence of the 1st eyeglass.The 2nd eyeglass and the 3rd eyeglass are that resin material forms; The Abbe number V2 of the 2nd eyeglass and the Abbe number V3 of the 3rd eyeglass satisfy following formula: 20.5＜V2＜35.3 or 45.3＜V3＜56.3,

45.3＜V3＜56.3 or 20.5＜V2＜35.3

Thickness on the optical axis direction of the 2nd eyeglass is D3, and the thickness beyond the optical axis is d3, and following formula is set up: 0.4＜| D3/d3|＜1

The radius-of-curvature of the object side of the 2nd eyeglass is R21, is R22 as the radius-of-curvature of side, satisfies following formula: 0.2＜| R21|/| R22|＜0.7

Adopt the taking lens of said structure, because the 2nd eyeglass has then center thickness book relatively of negative refractive power, make the total length of camera lens, can obtain good image quality, it is less that this structure also makes Dry Sack receive difference, and color saturation is better after the imaging.

When satisfied 20.5＜V2＜35.3 or 45.3＜V3＜56.3,45.3＜V3＜56.3 or 20.5＜V2＜35.3 o'clock, can well eliminate spool a last aberration and a lateral chromatic aberration.

When satisfy 0.2＜| R4|/| during R5|＜0.7, can obtain the short and small lens design group of light book, make lens construction more stable,, have the image quality of high-quality especially for CCD more than 1,300,000 pixels or CMOS.

Description of drawings

Fig. 1 is this novel embodiment structural drawing.

Embodiment

As shown in Figure 1, diaphragm 5 is positioned on the plane of light incidence 11 of eyeglass 1,12 is the 1st eyeglass light outgoing plane, and 21 is the 2nd eyeglass plane of light incidence, and 22 is the 2nd eyeglass light outgoing plane, 31 is the 3rd eyeglass plane of light incidence, 32 is the 3rd eyeglass light outgoing plane, and 41 is the 4th eyeglass plane of light incidence, and 42 is the 4th eyeglass beam projecting face, V1, V2, V3, V4 be the refractive index of the 1st, 2,3,4 eyeglasses respectively, the 2nd eyeglass and the 3rd eyeglass aspheric surface formula that satisfies condition:

$Z=\frac{\left(\mathrm{CURV}\right)Y^2}{1+{(1-(1+K){\left(\mathrm{CURV}\right)}^2{Y}^2)}^{1/2}}+\left(A2\right)Y^2+\left(A4\right)Y^4+\left(A6\right)Y^6+\left(A8\right)Y^8+\left(A10\right)Y^{10}$

$+\left(A12\right)Y^{12}+\left(A14\right)Y^{14}+\left(A16\right)Y^{16}$

Wherein: Z be from the tangent plane on the aspheric summit to the distance from the height of the optical axis L point to the aspheric surface of Y, Y is the height from optical axis L, C is the curvature (1/R) on the aspheric surface summit, A is an asphericity coefficient.

D3 is the thickness on the optical axis direction of the 2nd eyeglass, and d3 is the thickness beyond the 2nd lens light axis, and R21 is the radius-of-curvature of the 2nd eyeglass plane of light incidence, and R22 is the radius-of-curvature of the 2nd eyeglass light outgoing plane.And satisfy relational expression:

0.4＜|D3/d3|＜1 0.2＜|R21|/|R22|＜0.7

Embodiment one:

Enumerated concrete numerical value among the embodiment one based on the embodiment of said structure form.

Table 1

Focal length value (EFL): 4.5227
	Coke number behind the optics (BFL): 1.4956
F value: 2.83

Field angle: 64 degree
	Optical system length overall (containing glass filter): 5.87

Table 2

The surface sequence number	Radius-of-curvature (mm)	One-tenth-value thickness 1/10 D (mm)	Peripheral thickness d (mm)	Refractive index	Abbe number
						Object plane	Infinitely great	Infinitely great
Diaphragm
	11	2.039037	0.910000	0.762263	N1 1.497	V1 81.60
12							87.095946	0.880000	0.496429
	21	-1.021193	0.530000	0.619902						N2 1.5854	V2 29.90
22					-1.525744	0.330000	0.987485
	31	2.098245	1.070000	0.663702				N3 1.5347	V3 56.22(V3)
32					2.826104	0.250000	0.347546
	41	Infinitely great	0.420000	0.40						N4 1.5168	V4 64.16
42					Infinitely great	1.495687	1.465687
	Image planes	Infinitely great		0

Wherein 21 aspheric surface parameters of the 2nd eyeglass are:

K＝-0.178546

A＝0

B＝0.2876358

C＝-0.250395

D＝0.619472

E＝-1.4312667

F＝1.9225658

G＝-1.3604689

H＝0.40149893

Wherein 22 aspheric surface parameters of the 2nd mirror are:

K＝-0.3988513

A＝0

B＝0.062014856

C＝0.021952798

D＝-0.10766524

E＝0.23005983

F＝-0.16402605

G＝0.008

H＝-0.0086744717

Wherein 31 aspheric surface parameters of the 3rd mirror are:

K＝-6.0483956

A＝0

B＝0.0089276837

C＝-0.04032201

D＝0.015584217

E＝-0.0032543965

F＝0.0005692607

G＝-0.00001

H＝-0.00000080024186

Wherein 33 aspheric surface parameters of the 3rd mirror are:

K＝-1.0389857

A＝0

B＝-0.062012244

C＝-0.0022513091

D＝0.0024690739

E＝0.0006636716

F＝0.000085963019

G＝-0.000004

H＝0.00000000079354962

Wherein, satisfy the value of bar formula:

V2＝29.20 20.5＜V2＜35.3

V3＝56.22 45.3＜V3＜56.3

D3/d3＝0.84 0.4＜|D3/d3|＜1

|R21|/|R22|＝0.67 0.2＜|R21|/|R22|＜0.7

Embodiment two:

Enumerated concrete numerical value among the embodiment two based on the embodiment of said structure form.

Table 1

Focal length value (EFL): 4.5127
	Coke number behind the optics (BFL): 1.4756
F value: 2.83
	Field angle: 64 degree
Optical system length overall (containing glass filter): 5.86

Table 2

The surface sequence number	Radius-of-curvature (mm)	One-tenth-value thickness 1/10 D (mm)	Peripheral thickness d (mm)	Refractive index	Abbe number
						Object plane	Infinitely great	Infinitely great

Diaphragm 11	2.059037	0.920000	0.742263	N1 1.497	V1 81.60
						12	87.095946	0.870000	0.496429
21	-1.031193	0.550000	0.653702							N2 1.5247	V2 56.22
				22	-1.515744	0.340000	0.977485
31	2.088245	1.060000	0.619902					N3 1.5854	V3 29.90
				32	2.816104	0.240000	0.337546
41	Infinitely great	0.410000	0.41							N4 1.5168	V4 64.16
				42	Infinitely great	1.475687	1.475687
Image planes	Infinitely great		0

Wherein 21 aspheric surface parameters of the 2nd eyeglass are:

K＝-0.178546

A＝0

B＝0.2676358

C＝-0.230395

D＝0.609472

E＝-1.4312667

F＝1.9125658

G＝-1.3404689

H＝0.41149893

Wherein 22 aspheric surface parameters of the 2nd mirror are:

K＝-0.3988513

A＝0

B＝0.072014856

C＝0.031952798

D＝-0.12766524

E＝0.21005983

F＝-0.15402605

G＝0.008

H＝-0.0056744717

Wherein 31 aspheric surface parameters of the 3rd mirror are:

K＝-6.0683956

A＝0

B＝0.0089276837

C＝-0.03032201

D＝0.025584217

E＝-0.0042543965

F＝0.0005792607

G＝-0.00001

H＝-0.00000080024186

Wherein 32 aspheric surface parameters of the 3rd mirror are:

K＝-1.0689857

A＝0

B＝-0.052012244

C＝-0.0022513091

D＝0.0024690739

E＝0.0006636716

F＝0.000085963019

G＝-0.000004

H＝0.00000000079354962

Wherein, satisfy the value of bar formula:

V2＝56.22 20.5＜V2＜35.3 or 45.3＜V2＜56.3

V3＝29.90 20.5＜V3＜35.3 or 45.3＜V3＜56.3

D3/d3＝0.84 0.4＜|D3/d3|＜1

|R21|/|R22|＝0.68 0.2＜|R21|/|R22|＜0.7

Claims (6)

1, a kind of taking lens, extremely include diaphragm, eyeglass from the thing side of taking lens as the side, wherein the plane of light incidence of the 1st eyeglass is convex surface and has positive refractive power, the plane of light incidence of the 3rd eyeglass is convex surface and is to have the aspheric surface of negative refractive power, the 4th eyeglass is a glass filter, it is characterized in that: the 2nd eyeglass is that plane of light incidence has aspheric surface and is tending towards the diminishing mode of optical axis direction part refractive power and form.

2, according to the described taking lens of claim 1, it is characterized in that: diaphragm is positioned on the plane of light incidence of the 1st eyeglass.

3, the described taking lens of claim 1 is characterized in that: the 2nd eyeglass and the 3rd eyeglass are that resin material forms.

4, according to claim 1,2 or 3 described taking lenss, it is characterized in that: the Abbe number V2 of the 2nd eyeglass and the Abbe number V3 of the 3rd eyeglass satisfy following formula:

20.5＜V2＜35.3 or 45.3＜V3＜56.3,

45.3＜V3＜56.3 or 20.5＜V2＜35.3.

5, according to claim 1,2 or 3 described taking lenss, it is characterized in that: the thickness on the optical axis direction of the 2nd eyeglass is D3, and the thickness beyond the optical axis is d3, and following formula is set up:

0.4＜|D3/d3|＜1。

6, according to claim 1,2 or 3 described taking lenss, it is characterized in that: the radius-of-curvature of the object side of the 2nd eyeglass is R21, is R22 as the radius-of-curvature of side, satisfies following formula:

0.2＜|R21|/|R22|＜0.7。

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