CN100439963C - Ultraminiature zoom lens - Google Patents

Abstract

A zoom lens of subminiature type is prepared as setting the first negative diopter lens set formed by a negative lens and a positive lens as well as the second positive diopter lens set formed by a glued group and a negative lens in sequence from object space to image space, setting position of said first lens set to imaging surface to be fixed and moving said second lens set to vary distance to the first one for realizing verifocus function.

Description

Ultraminiature zoom lens

Technical field

The present invention relates to a kind of Zoom lens system, relate to a kind of Ultraminiature zoom lens of the high zoom ratios that constitutes by two lens combination specifically.

Background technology

The zoom lens that is applied to shooting mobile phone and digital camera at present adopts three lens combination mostly, as China Patent No. be 200410078895.7 " zoom lens " be exactly a kind of have negative, negative, the zoom lens of positive three lens combination, its first lens combination stationkeeping, change the distance between second lens combination and first lens combination and make the focal length variations of whole camera lens, and the imaging surface that causes behind the change compensation zoom by the 3rd lens combination position moves, the imaging surface position is remained to immobilize, though satisfying, takes far the zoom lens of this three lens group, the demand at myopia angle, and optical zoom can reach near 2 times, but as small-sized, especially microminiature mobile phone or digital camera, volume is still bigger, and second group, two micro motors of the mobile needs of the 3rd set of shots group drive together, not only improve production cost, and waste more battery electric power; For this reason, industrial community is also designed two groups of lens combination only using a motor driven, a lens combination is fixed, another lens combination promotes to carry out zoom by motor, as disclosed China Patent No. is 95115883.X " zoom lens ", though its zoom lens has had the unexistent advantage of zoom lens of three lens combination, yet still expose many defectives in actual use, for example change to long sight angle or near-sighted angle shooting state at general shooting state, or during by the conversion of long sight angle myopia angle, the length overall of whole camera lens will the conversion along with the variation of shooting state, the zoom lens that this entire length can change is obsolete for general mobile phone, the one, because in the member of the mobile phone that is difficult to pack into, the 2nd, because be easy to make mobile lens to be worn and torn, and two required eyeglasses of lens combination of this zoom lens are more, also increased mobile phone weight virtually.

Summary of the invention

Technical matters to be solved by this invention is to overcome the defective of prior art and the Ultraminiature zoom lens that a kind of compact conformation, volume are extra small, weight is light, zoom capabilities is strong is provided.

Technical matters of the present invention is achieved through the following technical solutions:

A kind of Ultraminiature zoom lens, comprise having negative dioptric first lens combination and have second lens combination of positive diopter from the object side to the image side successively, in the zoom process, the invariant position of first lens combination and imaging surface, the distance variable of relative first lens combination of second lens combination is characterized in that:

Described first lens combination comprises from the object side to the image side successively:

A slice is bi-concave negative lens;

A slice is the positive lens of positive bent moon;

Described second lens combination comprises from the object side to the image side successively:

A slice has the gummed group of the band list convex surface of positive diopter, and this gummed group is to be formed by a slice positive lens and a slice negative lens gummed;

A slice is the negative lens of negative bent moon;

Zoom lens must satisfy following formula:

1.35＜-FG1/FG2＜1.65

0.33＜Wb/OAL＜0.4

In the formula, FG1: the focal length of negative dioptric first lens combination,

FG2: the focal length of second lens combination of positive diopter,

Wb: rear cut-off distance during wide-angle position,

OAL: whole lens play the length of imaging surface from object space first eyeglass,

Simultaneously must satisfy following formula:

(V1G1-V2G1)＞20

V1G2/V2G2＞2.35

0.33＜|F1G1|/F2G1＜0.4

15＜F3G2/FG2＜20

In the formula, V1G1: the Abbe number of the first lens combination negative lens,

V2G1: the Abbe number of the first lens combination positive lens,

V1G2: the positive lens Abbe number of the second lens combination gummed group,

V2G2: the negative lens Abbe number of the second lens combination gummed group,

F1G1: the focal length of the first lens combination negative lens,

F2G1: the focal length of the first lens combination positive lens,

F3G2: the focal length of the negative bent moon negative lens of second lens combination,

FG2: the focal length of second lens combination of positive diopter.

Two lens surfaces of described first lens combination are aspheric surface.It is aspheric surface that the negative bent moon negative lens of described second lens combination has a surface at least.

The aspheric surface of two lens of described first lens combination and the negative bent moon negative lens of second lens combination must satisfy following formula:

$Z\left(h\right)=\frac{{\mathrm{<figure-callout\; id="2"\; label="ch"\; filenames="C20061015528800101.png"\; state="\{\{state\}\}">ch</figure-callout>}}^2}{1+\sqrt{1-(1+k)c^2{\mathrm{<figure-callout\; id="2"\; label="h"\; filenames="C20061015528800101.png"\; state="\{\{state\}\}">h</figure-callout>}}^2}}+{\mathrm{<figure-callout\; id="4"\; label="Ah"\; filenames="C20061015528800101.png"\; state="\{\{state\}\}">Ah</figure-callout>}}^4+{\mathrm{<figure-callout\; id="6"\; label="Bh"\; filenames="C20061015528800101.png"\; state="\{\{state\}\}">Bh</figure-callout>}}^6+{\mathrm{Ch}}^8+{\mathrm{Dh}}^{10}+E{h}^{12}$

In the formula: Z is an aspheric surface along optical axis direction highly for the position of h the time, apart from the aspheric surface summit apart from rise sag

C=1/r, r represents radius-of-curvature, k is circular cone coefficient conic, A, B, C, D, E are the high order aspheric surface coefficient.

Be provided with the eliminate stray light spacer ring between described first lens combination and second lens combination.

Object space one side of described second lens combination is provided with the diaphragm spacer ring.

The surface location of described second lens combination is provided with zero diopter glass sheet or infrared fileter.

Compared with prior art, the present invention comprises having negative dioptric first lens combination and have second lens combination of positive diopter from the object side to the image side successively, first lens combination is made up of negative lens and positive lens, second lens combination is made up of gummed group and negative lens, the stationkeeping of first lens combination and imaging surface, change in location by second lens combination and first lens combination is carried out optical zoom and automatic focusing, and automatic focusing can compensate the imaging surface that causes behind the zoom and move, it is constant that the imaging surface position is remained, the zoom lens of this structure adopts aspheric eyeglass effectively to correct aberration and guarantee that the quality of image is good, have good optical property and powerful zoom capabilities, and compact conformation, weight is lighter, zoom capabilities is strong, realized the subminiaturization of camera lens, having looks in the distance takes and the wide angle shot function, is specially adapted to fields such as camera mobile phone or miniature digital camera.

Description of drawings

Fig. 1 is the structural representation of lens combination of the present invention.(object space is in left-most position, is in right-most position as the side)

The sectional view of Fig. 2 during for the system wide-angle of zoom lens of the present invention.

The chromaticity difference diagram of Fig. 3 during for the system wide-angle of zoom lens of the present invention.

The astigmatism figure of Fig. 4 during for the system wide-angle of zoom lens of the present invention

The distortion figure of Fig. 5 during for the system wide-angle of zoom lens of the present invention.

The ratio chromatism, figure of Fig. 6 during for the system wide-angle of zoom lens of the present invention.

Chromaticity difference diagram when Fig. 7 looks in the distance for the system of zoom lens of the present invention.

Astigmatism figure when Fig. 8 looks in the distance for the system of zoom lens of the present invention.

Distortion figure when Fig. 9 looks in the distance for the system of zoom lens of the present invention.

Ratio chromatism, figure when Figure 10 looks in the distance for the system of zoom lens of the present invention.

Embodiment

To elaborate again to the embodiment of the invention by above-mentioned accompanying drawing below.

As Fig. 1～shown in Figure 10, Ultraminiature zoom lens, its object space is in the left-most position of whole camera lens, picture side is in the right-most position of whole camera lens, comprise successively from the object side to the image side and have negative dioptric first lens combination and have second lens combination of positive diopter, described first lens combination comprises successively that from the object side to the image side a slice is the positive lens 2 that bi-concave negative lens 1 and a slice are positive bent moon, two eyeglasses adopt the plastics mould model, its surface is aspheric surface, and be fixed on camera lens foremost, play the effect of receiving light, make whole zoom lens angle of visibility when the wide-angle state reach 63.5 ° by this lens combination; Described second lens combination comprises the gummed group of a slice band list convex surface and the negative lens 5 that a slice is negative bent moon from the object side to the image side successively, the gummed group has positive diopter, be to form by a slice positive lens 3 and a slice negative lens 4 gummeds, single convex surface of gummed group is towards object space one side, it is aspheric surface that the negative lens 5 that is negative bent moon has a surface at least, and adopting plastics to make, second lens combination is mainly used in the focal length that changes camera lens.

This zoom lens must satisfy following formula:

1.35＜-FG1/FG2＜1.65

0.33＜Wb/OAL＜0.4

In the formula, FG1: the focal length of negative dioptric first lens combination,

FG2: the focal length of second lens combination of positive diopter,

Wb: rear cut-off distance during wide-angle position,

OAL: whole lens play the length of imaging surface from thing side first eyeglass,

Simultaneously, also must satisfy following formula:

(V1G1-V2G1)＞20

V1G2/V2G2＞2.35

0.33＜|F1G1|/F2G1＜0.4

15＜F3G2/FG2＜20

In the formula, V1G1: the Abbe number of the first lens combination negative lens,

V2G1: the Abbe number of the first lens combination positive lens,

V1G2: the positive lens Abbe number of the second lens combination gummed group,

V2G2: the negative lens Abbe number of the second lens combination gummed group,

F1G1: the focal length of the first lens combination negative lens,

F2G1: the focal length of the first lens combination positive lens,

F3G2: the focal length of the negative bent moon negative lens of second lens combination,

FG2: the focal length of second lens combination of positive diopter.

The aspheric surface of two lens of first lens combination and the negative bent moon negative lens of second lens combination must satisfy following formula:

$Z\left(h\right)=\frac{{\mathrm{<figure-callout\; id="2"\; label="ch"\; filenames="C20061015528800101.png"\; state="\{\{state\}\}">ch</figure-callout>}}^2}{1+\sqrt{1-(1+k)c^2{\mathrm{<figure-callout\; id="2"\; label="h"\; filenames="C20061015528800101.png"\; state="\{\{state\}\}">h</figure-callout>}}^2}}+{\mathrm{<figure-callout\; id="4"\; label="Ah"\; filenames="C20061015528800101.png"\; state="\{\{state\}\}">Ah</figure-callout>}}^4+{\mathrm{<figure-callout\; id="6"\; label="Bh"\; filenames="C20061015528800101.png"\; state="\{\{state\}\}">Bh</figure-callout>}}^6+{\mathrm{Ch}}^8+{\mathrm{Dh}}^{10}+E{h}^{12}$

In the formula: Z is an aspheric surface along optical axis direction highly for the position of h the time, apart from the aspheric surface summit apart from rise sag

C=1/r, r represents radius-of-curvature, k is circular cone coefficient conic, A, B, C, D, E are the high order aspheric surface coefficient.

Between first lens combination and second lens combination, also be provided with eliminate stray light spacer ring (not shown) in order to eliminate the veiling glare of eyeglass inner reflection, object space one side in second lens combination is provided with diaphragm spacer ring (not shown), in order to guaranteeing that light injects from the effective aperture of eyeglass, and be provided with zero diopter glass sheet or infrared fileter 6 at the surface location of second lens combination.

During this Ultraminiature zoom lens zoom, the stationkeeping of first lens combination and imaging surface 7 is constant, move by motor driven second lens combination, change distance with first lens combination, reach zoom function and automatic focusing function, move and automatic focusing can compensate the imaging surface that causes behind the zoom, make the position of imaging surface remain constant.

Ultraminiature zoom lens has different design datas under different situations:

What following table was listed is the relevant model of all lens, the radius-of-curvature and the diameter of lens face, also has the center thickness, airspace of each lens, the refractive index and the Abbe number of the optical material of order successively from the object side to the image side:

The face sequence number	Surface type	Radius-of-curvature	Center thickness	Nd/Vd	Logical light diameter
						OBJ	STANDARD	Infinity	Infinity	AIR	Infinity
*1	EVENASPH	-4.139515	0.61	1.5434/56.04	5.3
						*2	EVENASPH	5.492069	0.5353669	AIR	3.8
*3	EVENASPH	2.993252	0.84	1.58547/29.9	4
						*4	EVENASPH	4.861913	Variable	AIR		4
STO	STANDARD	Infinity	-0.4	AIR	2.85
						6	STANDARD	2.615	1.94	1.640495/60.09	3.8
7	STANDARD	-6.102	0.41	1.84666/23.83	3.8
						8	STANDARD	132.99	0.3781529	AIR	3
*9	EVENASPH	3.232402	0.65	1.5434/56.04	2.9
						*10	EVENASPH	2.783366	Variable	AIR	2.9
11	STANDARD	Infinity	0.9	1.5168/64.17	3.368221
						12	STANDARD	Infinity	1.5	AIR	3.716686
IMA	STANDARD	Infinity		0	AIR							5.847144

That following table is listed is aspheric surface COEFFICIENT K, A, B, C, D, E:

The face sequence number	K	A	B	C	D	E
							1	-21.1592262	0.014512886	-0.001254167	-6.87712E-05	1.89964E-05	-1.17007E-06
2	4.73629386	0.019814881	-6.35807E-05	0.000465156	0.000184009	-6.46484E-05
							3	-4.33735526	-0.020564676	0.005031358	0.000504641	-0.000171941	-9.45112E-06
4	-10.9465579	-0.014431306	0.000829334	0.001218009	-0.000490966	4.36882E-05

9	0.180780819	-0.016948861	-0.020682114	0.007709464	-0.003630827	0.000377549
							10	0.62920264	-0.002456423	-0.011381134	-0.001875958	0.001441617	-0.000205616

Following table is listed be camera lens respectively at wide-angle with the specification coefficient when looking in the distance state:

	Wide-angle	Look in the distance
			Focal length (EFL)	4.85	9.6
Relative aperture (FNO)	2.8	4.2
			Field angle (FOV)	66.8°	34.6°
Center thickness 4	3.6674	0.607
			Center thickness 10	2.899	5.959

The present invention has shooting of looking in the distance and wide angle shot function, two lens combination only adopt five lens to constitute, make structure compact more, size can be reduced to 7.5mm, and optical zoom still can reach 2 times, effectively save production cost, in the mobile phone part of can packing into very easily simultaneously, realize the subminiaturization of camera lens.

Claims (8)

1, a kind of Ultraminiature zoom lens, comprise successively from the object side to the image side and have negative dioptric first lens combination and have second lens combination of positive diopter, in the zoom process, the invariant position of first lens combination and imaging surface (7), the distance variable of relative first lens combination of second lens combination is characterized in that:

Described first lens combination comprises from the object side to the image side successively:

A slice is bi-concave negative lens (1);

A slice is the positive lens (2) of positive bent moon;

Described second lens combination comprises from the object side to the image side successively:

A slice has the gummed group of the band list convex surface of positive diopter, and this gummed group is to be formed by a slice positive lens (3) and a slice negative lens (4) gummed;

A slice is the negative lens (5) of negative bent moon;

Zoom lens must satisfy following formula:

1.35＜-FG1/FG2＜1.65

0.33＜Wb/OAL＜0.4

In the formula, FG1: the focal length of negative dioptric first lens combination,

FG2: the focal length of second lens combination of positive diopter,

Wb: rear cut-off distance during wide-angle position,

OAL: whole lens play the length of imaging surface from object space first eyeglass,

Simultaneously must satisfy following formula:

(V1G1-V2G1)＞20

V1G2/V2G2＞2.35

0.33＜|F1G1|/F2G1＜0.4

15＜F3G2/FG2＜20

In the formula, V1G1: the Abbe number of the first lens combination negative lens,

V2G1: the Abbe number of the first lens combination positive lens,

V1G2: the positive lens Abbe number of the second lens combination gummed group,

V2G2: the negative lens Abbe number of the second lens combination gummed group,

F1G1: the focal length of the first lens combination negative lens,

F2G1: the focal length of the first lens combination positive lens,

F3G2: the focal length of the negative bent moon negative lens of second lens combination,

FG2: the focal length of second lens combination of positive diopter.

2, Ultraminiature zoom lens according to claim 1 is characterized in that two lens surfaces of described first lens combination are aspheric surface.

3, Ultraminiature zoom lens according to claim 1, it is aspheric surface that the negative bent moon negative lens (5) that it is characterized in that described second lens combination has a surface at least.

4, Ultraminiature zoom lens according to claim 2 is characterized in that the aspheric surface of two lens of described first lens combination must satisfy following formula:

$Z\left(h\right)=\frac{{\mathrm{ch}}^2}{1+\sqrt{1-(1+k)c^2{h}^2}}+{\mathrm{Ah}}^4+{\mathrm{Bh}}^6+{\mathrm{Ch}}^8+{\mathrm{Dh}}^{10}+{\mathrm{Eh}}^{12}$

In the formula: Z is an aspheric surface along optical axis direction highly for the position of h the time, apart from the aspheric surface summit apart from rise sag

C=1/r, r represents radius-of-curvature, k is circular cone coefficient conic, A, B, C, D, E are the high order aspheric surface coefficient.

5, Ultraminiature zoom lens according to claim 3 is characterized in that the aspheric surface of the negative bent moon negative lens of described second lens combination must satisfy following formula:

$Z\left(h\right)=\frac{{\mathrm{ch}}^2}{1+\sqrt{1-(1+k)c^2{h}^2}}+{\mathrm{Ah}}^4+{\mathrm{Bh}}^6+{\mathrm{Ch}}^8+{\mathrm{Dh}}^{10}+{\mathrm{Eh}}^{12}$

In the formula: Z is an aspheric surface along optical axis direction highly for the position of h the time, apart from the aspheric surface summit apart from rise sag

C=1/r, r represents radius-of-curvature, k is circular cone coefficient conic, A, B, C, D, E are the high order aspheric surface coefficient.

6, Ultraminiature zoom lens according to claim 1 is characterized in that being provided with the eliminate stray light spacer ring between described first lens combination and second lens combination.

7, Ultraminiature zoom lens according to claim 1 is characterized in that object space one side of described second lens combination is provided with the diaphragm spacer ring.

8, Ultraminiature zoom lens according to claim 1 is characterized in that the surface location of described second lens combination is provided with zero diopter glass sheet or infrared fileter (6).

Images