CN101295070A - Zoom lens - Google Patents

Abstract

The invention relates to a zoom lens which comprises a first lens group, a second lens group, aperture stop, a third lens group and a fourth lens group which are sequentially positioned at an optical axis from an object end to an imaging end, wherein, the zoom lens meets the following conditions: (see the formula), Y is the maximum length of an opposite angle at the imaging end, L is the total length of the zoom lens, f W is the focal distance of the zoom lens at a wide-angle end, and f T is the focal distance of the zoom lens at long-range.

Description

Zoom lens

Technical field

The present invention relates to a kind of camera lens, and be particularly related to a kind of zoom lens.

Background technology

In recent years, the camera apparatus fast development, and be tending towards compact design, the optical lens design on the camera is also just got over important.General camera lens can be divided into tight shot and zoom lens, and the pancratic characteristic of zoom lens can for camera provides multiple composition, and be subjected to using widely under the design of single lens.

Though the zoom lens design has developed one period time, but the optical system cost and the image quality of whole zoom lens, many progressive spaces are still arranged, especially present various portable electronic equipments all are equiped with under the prerequisite of image capture unit, one of condition of required consideration was too huge with the volume of avoiding portable electronic equipment when the length of zoom lens also was design.

Therefore how to reduce the optical system cost and the volume of zoom lens, and good image quality is provided, make the related application device can dwindle overall volume and cost, the target of being made great efforts for each manufacturer at present.

Summary of the invention

Therefore the technical problem to be solved in the present invention is, a kind of zoom lens is provided, and in order to reducing cost and volume, and provides good image quality.

The technical scheme that the present invention is adopted for its technical matters of solution is, proposes a kind of zoom lens, includes first lens combination, second lens combination, the 3rd lens combination, the 4th lens combination and aperture diaphragm by the thing end in regular turn to the imaging end on optical axis.First lens combination is positive refractive index, has the first crescent lens and second convex lens that inadhesion is intervally installed.Second lens combination is negative refractive index.The 3rd lens combination is positive refractive index, engaged with the 6th biconcave lens by the 5th biconvex lens to form, and the 5th biconvex lens is by near the object end.The 4th lens combination is positive refractive index, and aperture diaphragm is arranged between second lens combination and the 3rd lens combination.When zoom lens carried out zoom, second lens combination and the 3rd lens combination can be carried out rightabout moving on this optical axis, and first lens combination and the aperture diaphragm position on optical axis is maintained fixed.

In zoom lens of the present invention, two lens of described first lens combination are the first crescent concavees lens and second convex lens from thing end to imaging end in regular turn, and the thing end surfaces of the described first crescent concavees lens protrudes towards described thing end.

In zoom lens of the present invention, described first lens combination is a glass material, and the described first crescent concavees lens and described second convex lens are spherical lens.

In zoom lens of the present invention, described first lens combination is a plastic material, and described first lens combination has at least one aspheric surface.

In zoom lens of the present invention, described two lens combination have the 3rd concavees lens and the 4th convex lens in regular turn from thing end to imaging end.

In zoom lens of the present invention, described the 4th convex lens are that the Abbe coefficient is made less than 30 plastic material.

In zoom lens of the present invention, described the 4th convex lens have at least one side to be aspheric surface.

In zoom lens of the present invention, the disengaged face of described the 5th biconvex lens and described the 6th biconcave lens all has the aspheric surface that the resin compounded eyeglass is constituted.

In zoom lens of the present invention, described the 5th biconvex lens and described the 6th biconcave lens are the glass moulding eyeglass, and disengaged face is all aspheric surface.

In zoom lens of the present invention, described the 4th lens combination is made up of the 7th plastic lens, and it at least simultaneously is aspheric surface that described the 7th plastic lens has.

In zoom lens of the present invention, described the 4th lens combination moves along optical axis when described zoom lens is focused.

In zoom lens of the present invention, meet following condition:

$\frac{Y\×L}{2\×f_W\×f_T}\≤1.06$

Wherein, Y is an imaging end diagonal angle maximum length, and L is described zoom lens total length, f _WBe the focal length of described zoom lens in wide-angle side, f _TBe the focal length of described zoom lens in the journey of looking in the distance.

In zoom lens of the present invention, more comprise wave filter, be arranged between described the 4th lens combination and the described imaging end.

The invention allows for a kind of zoom lens, on optical axis, include first lens combination, second lens combination, the 3rd lens combination and the 4th lens combination in regular turn to the imaging end by the thing end.First lens combination is positive refractive index, has the first crescent concavees lens and second convex lens.The first crescent concavees lens are by near the object end, and the thing end face of the first crescent concavees lens protrudes towards the thing end.In addition, the first crescent concavees lens and second convex lens predeterminable range and being provided with at interval.Second lens combination has the 3rd concavees lens and the 4th convex lens for negative refractive index, and the 3rd concavees lens are by near the object end.The 3rd lens combination is positive refractive index, engaged with the 6th biconcave lens by the 5th biconvex lens to form, and the 5th biconvex lens is by near the object end.The 4th lens combination is positive refractive index, be made up of the 7th plastic lens, and the 7th plastic lens has at least, and one side is aspheric surface.Wherein, zoom lens meet following condition:

$\frac{Y\×L}{2\×f_W\×f_T}\≤1.06$

Y is an imaging end diagonal angle maximum length, and L is the zoom lens total length, f _WBe the focal length of zoom lens in wide-angle side, f _TBe the focal length of zoom lens in the journey of looking in the distance.

In zoom lens of the present invention, when carrying out zoom, described second lens combination and described the 3rd lens combination are carried out rightabout moving on described optical axis, and described first lens combination is maintained fixed the position on described optical axis.

In zoom lens of the present invention, described first lens combination is a glass material, and the described first crescent concavees lens and described second convex lens are spherical lens.

In zoom lens of the present invention, described first lens combination is a plastic material, and described at least one face of first lens combination is an aspheric surface.

In zoom lens of the present invention, described the 4th convex lens are that the Abbe coefficient is made less than 30 plastic material.

In zoom lens of the present invention, described the 4th convex lens have at least one side to be aspheric surface.

In zoom lens of the present invention, the disengaged face of described the 5th biconvex lens and described the 6th biconcave lens has more the aspheric surface that a resin compounded eyeglass is constituted.

In zoom lens of the present invention, described the 5th biconvex lens and described the 6th biconcave lens are the glass moulding eyeglass, and disengaged is aspheric surface.

In zoom lens of the present invention, described the 4th lens combination moves along optical axis when described zoom lens is focused.

In zoom lens of the present invention, more comprise wave filter, be arranged between the 4th lens combination and the described imaging end.

In zoom lens of the present invention, more comprise aperture diaphragm, be arranged between described second lens combination and described the 3rd lens combination, and described aperture diaphragm to be when described zoom lens zoom, the position on described optical axis is maintained fixed.

The zoom lens of the embodiment of the invention adopts the framework of four group lens combination that good image quality is provided.And has a predeterminable range between each eyeglass of first lens combination, to reduce the possibility that ghost takes place.Adopt many pieces of glass lens on varifocal mirror first watch, reducing cost, and, shorten the length of optical system by suitable optical parametric design.

Description of drawings

For above and other objects of the present invention, feature, advantage and embodiment can be become apparent, being described in detail as follows of accompanying drawing:

Figure 1A is the synoptic diagram of the zoom lens of one embodiment of the invention in wide-angle side.

Figure 1B is that the zoom lens of one embodiment of the invention is in the synoptic diagram of the journey of looking in the distance.

Fig. 2 A is respectively the astigmatism figure of first embodiment of the invention under 62 degree, 41 degree, 22 degree field angle to 2C.

Fig. 3 A is respectively the distortion aberration diagram of first embodiment of the invention under 62 degree, 41 degree, 22 degree field angle to 3C.

Fig. 4 A is respectively the spherical aberration diagram of first embodiment of the invention under 62 degree, 41 degree, 22 degree field angle to 4C.

Fig. 5 A is respectively the multiplying power chromatic aberation figure of first embodiment of the invention under 62 degree, 41 degree, 22 degree field angle to 5C.

Fig. 6 A is respectively the comet aberration diagram of first embodiment of the invention under 62 degree, 41 degree, 22 degree field angle to 6C.

Embodiment

Zoom lens embodiment of the present invention has the four group lens combination, improves image quality, and partly lens use plastic material, to reduce whole cost.Those skilled in the art, without departing from the spirit and scope of the present invention, the material of variable optical parametric wherein and part lens is with the situation of realistic application.

Please refer to Figure 1A.This figure is that the zoom lens 100 of embodiment is in the synoptic diagram of wide-angle side (Wide-Angle).When zoom lens 100 was arranged on the camera, imaging end 170 was photosensory assembly.Zoom lens 100 in regular turn includes first lens combination 110, second lens combination 120, three lens combination 130 and four lens combination 140 to imaging end 170 in optical axis on 180 by thing end 190.First lens combination 110 is positive refractive index, and has the first crescent concavees lens 112 and second convex lens 114.The first crescent concavees lens 112 lean near the object end 190 than second convex lens 114, and the first crescent concavees lens 112 and 114 on second convex lens are separated with a predeterminable range and are provided with, that is first crescent concavees lens 112 and second convex lens, 114 inadhesions and be intervally installed, to reduce the possibility that ghost takes place.

Second lens combination 120 has the 3rd concavees lens 122 and the 4th convex lens 124 for negative refractive index.The 3rd concavees lens 112 lean near the object end 190 than the 4th convex lens 124.

The 3rd lens combination 130 is positive refractive index, engaged with the 6th biconcave lens 134 by the 5th biconvex lens 132 to form, and the 5th biconvex lens 132 leans near the object end 190 than the 6th biconcave lens 134.The 4th lens combination 140 is positive refractive index, has the 7th plastic lens 142, and the 7th plastic lens has at least one side to be aspheric surface.In addition, zoom lens 100 has more aperture diaphragm 150 and is arranged between second lens combination 120 and the 3rd lens combination 130.

Then please be simultaneously with reference to Figure 1B, this is that zoom lens 100 is in the synoptic diagram of the journey of looking in the distance (Telephoto).When zoom lens 100 carried out zoom, second lens combination 120 and the 3rd lens combination 130 can be carried out rightabout moving on optical axis 180.When zoom lens 100 is become when looking in the distance journey by wide-angle side, second lens combination 120 moves toward the direction of imaging ends 170, and 130 directions to thing end 190 of the 3rd lens combination move.And in the whole zoom process, first lens combination 110 is maintained fixed with the position of aperture diaphragm 150 on optical axis 180.

The first crescent concavees lens 122 curved surface thing end surfaces in first lens combination 110 protrude towards thing end 190.In whole zoom process, the position of first lens combination 110 remains unchanged, and first lens combination 110 is glass material, and the first crescent concavees lens 112 and second convex lens 124 are spherical lens.In other embodiment, first lens combination 110 also can be plastic material, and first lens combination 110 has at least one side to be aspheric surface.

The 4th convex lens 124 in second lens combination 120 are made less than 30 plastic material by Abbe coefficient (Vd), and have at least one side to be aspheric surface.

On disengaged of the 5th biconvex lens 132 of the 3rd lens combination 130 and the 6th biconcave lens 134, has the aspheric surface that resin compounded eyeglass 136 is constituted.In other embodiment, the 5th biconvex lens 132 and the 6th biconcave lens 134 also can be the glass moulding eyeglass, and disengaged face all is an aspheric surface.

The 7th plastic lens 142 of the 4th lens combination 140 moves along optical axis 180 when zoom lens 100 is focused.When zoom lens 100 when closely finding a view, the 4th lens combination 140 moves to the direction of the 3rd lens combination 130.In addition, the 4th lens combination 140 also can move along optical axis 180 when zoom lens 100 carries out zoom, perhaps moves along optical axis 180 behind zoom, with the usefulness as the revisal of zoom system, pancreatic system.

And the zoom lens 100 of embodiment more meets following condition:

$\frac{Y\×L}{2\×f_W\×f_T}\≤1.06$

Wherein, Y is an imaging end diagonal angle maximum length, and L is zoom lens 100 total lengths, f _WBe the focal length of zoom lens in wide-angle side, f _TBe the focal length of zoom lens in the journey of looking in the distance.

In addition, zoom lens 100 comprises wave filter 160, is arranged between the 4th lens combination 140 and the imaging end 170.

For practicality and the advantage that shows zoom lens 100, will be according to above-mentioned condition design implementation example, and openly go out optical parametric and optical characteristics icon among the embodiment.

First embodiment

Table 1 is enumerated the parameters of each lens combination of zoom lens in regular turn, and first bit digital in the wherein surperficial sequence number is represented the lens numbering from the thing end to the imaging end, and second-order digit is represented the numbering of lens surface, by that analogy.STO. be aperture diaphragm, FS1 and FS2 are the two sides of wave filter.

Zoom lens is when zoom, and D1, D2, D3 and D4 change to some extent apart from meeting, and table 2 item is listed zoom lens in wide-angle side, the journey of looking in the distance and distance parameter (D1, D2, D3 and D4) between the two:

Can learn that by table 1 and table 2 zoom lens total length L is about 5 millimeters (mm), imaging end diagonal angle maximum length Y is about 1.25 millimeters (mm), the focal distance f of wide-angle side _WBe 1.0 millimeters (mm), the focal distance f of the journey of looking in the distance _TBe 3.0 millimeters (mm), so present embodiment meet above-mentioned conditional.

In addition, the zoom lens of embodiment has a plurality of aspheric surfaces, and non-spherical lens coefficient equation is as follows:

$z=\frac{{\mathrm{ch}}^2}{1+{[1-(k+1)c^2{h}^2]}^{1/2}}+{\mathrm{Ah}}^4+{\mathrm{Bh}}^6+{\mathrm{Ch}}^8+{\mathrm{<figure-callout\; id="10"\; label="Dh"\; filenames="A20071010298100191.png,A20071010298100201.png"\; state="\{\{state\}\}">Dh</figure-callout>}}^{10}$

Wherein, z is the sag value of lens, that is the depression degree of lens face, and c is the inverse of radius-of-curvature, and h is that lens face arrives distance between optical axes, and k is circular cone coefficient (Conic Coefficient), and A then is respectively the high-order asphericity coefficient to D.Circular cone coefficient and each aspheric high-order asphericity coefficient are listed in table 3 and the table 4 in regular turn:

Then please refer to Fig. 2 A to 2C, this is the astigmatism figure of present embodiment under different field angle (Field Angle).Wherein Fig. 2 A is 62 degree, and Fig. 2 B is 41 degree, and Fig. 2 C is 22 degree.M among each figure represents the meridional ray (Meridian Ray) of incident light, and S represents the sagittal ray (Sagittal Ray) of incident light.Horizontal ordinate is expressed as the distance of picture point to desirable image planes, and ordinate is desirable image height or incident angle.As shown in the figure, the astigmatism of zoom lens in wide-angle side to the journey of looking in the distance is all in 0.05 millimeter.

Fig. 3 A is the distortion aberration of present embodiment under different field angle to 3C.Wherein Fig. 3 A is 62 degree, and Fig. 3 B is 41 degree, and Fig. 3 C is 22 degree.Horizontal ordinate is expressed as the percent difference of picture point to ideal point among each figure, and ordinate is desirable image height or incident angle.By among the figure as can be known the distortion aberration of zoom lens in wide-angle side to the journey of looking in the distance all in 5%.

Please refer to Fig. 4 A to 4C, this is the spherical aberration diagram of zoom lens under different field angle of embodiment.Wherein Fig. 4 A is 62 degree, and Fig. 4 B is 41 degree, and Fig. 4 C is 22 degree.As shown in the figure, the astigmatism of zoom lens in wide-angle side to the journey of looking in the distance is all in 0.05 millimeter.

Fig. 5 A is the multiplying power chromatic aberation figure of zoom lens under different field angle of embodiment to 5C.Wherein Fig. 5 A is 62 degree, and Fig. 5 B is 41 degree, and Fig. 5 C is 22 degree.Shown in figure, the multiplying power chromatic aberation of zoom lens in wide-angle side to the journey of looking in the distance is all in 0.005 millimeter.

Please refer to Fig. 6 A to 6C, this is the comet aberration diagram of zoom lens under different field angle of embodiment.Wherein Fig. 6 A is under 62 degree, and image height is respectively at the comet aberration diagram of 0Y, 0.5Y and 0.7Y.Fig. 6 B is under 41 degree, and image height is respectively at the comet aberration diagram of 0Y, 0.5Y and 0.7Y.Fig. 6 C is under 22 degree, and image height is respectively at the comet aberration diagram of 0Y, 0.5Y and 0.7Y.By among the figure as can be known, all not serious under the situation of comet aberration in the overwhelming majority of zoom lens in wide-angle side to the journey of looking in the distance.

The zoom lens of the embodiment of the invention adopts the framework of four group lens combination to improve image quality, and has a predeterminable range between each eyeglass of first lens combination, can reduce the possibility that ghost takes place.In addition, partly eyeglass uses plastic material, can reduce cost, and by suitable optical parametric design, shorten the length of whole optical system.

Though the present invention with embodiment openly as above; but it is not in order to qualification the present invention, those skilled in the art, without departing from the spirit and scope of the present invention; can do various changes and retouching, thus protection scope of the present invention should with claim the person of being defined be as the criterion.

Claims (12)

1, a kind of zoom lens is characterized in that, is comprised at least in regular turn on optical axis by thing end to imaging end:

First lens combination is positive refractive index, two lens that have inadhesion and be intervally installed;

Second lens combination is negative refractive index;

The 3rd lens combination is positive refractive index, is engaged with the 6th biconcave lens by the 5th biconvex lens to form, and described the 5th biconvex lens is near described thing end;

The 4th lens combination is positive refractive index; And

Aperture diaphragm is arranged between second lens combination and the 3rd lens combination;

Wherein, when described zoom lens carried out zoom, described second lens combination and described the 3rd lens combination were carried out rightabout move on described optical axis, and described first lens combination and described aperture diaphragm are maintained fixed the position on described optical axis.

2, zoom lens as claimed in claim 1 is characterized in that, two lens of described first lens combination are the first crescent concavees lens and second convex lens from thing end to imaging end in regular turn, and the thing end surfaces of the described first crescent concavees lens protrudes towards described thing end.

3, zoom lens as claimed in claim 2 is characterized in that, described first lens combination is a glass material, and the described first crescent concavees lens and described second convex lens are spherical lens.

4, zoom lens as claimed in claim 2 is characterized in that, described first lens combination is a plastic material, and described first lens combination has at least one aspheric surface.

5, zoom lens as claimed in claim 1 is characterized in that, described two lens combination have the 3rd concavees lens and the 4th convex lens in regular turn from thing end to imaging end.

6, zoom lens as claimed in claim 5 is characterized in that, described the 4th convex lens are that the Abbe coefficient is made less than 30 plastic material.

7, zoom lens as claimed in claim 6 is characterized in that, described the 4th convex lens have at least one side to be aspheric surface.

8, zoom lens as claimed in claim 1 is characterized in that, the disengaged face of described the 5th biconvex lens and described the 6th biconcave lens all has the aspheric surface that the resin compounded eyeglass is constituted.

9, zoom lens as claimed in claim 1 is characterized in that, described the 5th biconvex lens and described the 6th biconcave lens are the glass moulding eyeglass, and disengaged face is all aspheric surface.

10, zoom lens as claimed in claim 1 is characterized in that, described the 4th lens combination is made up of the 7th plastic lens, and it at least simultaneously is aspheric surface that described the 7th plastic lens has.

11, zoom lens as claimed in claim 1 is characterized in that, described the 4th lens combination moves along optical axis when described zoom lens is focused.

12, zoom lens as claimed in claim 1 is characterized in that, described zoom lens meets following condition:

$\frac{Y\&times;L}{2\&times;f_W\&times;f_T}\&le;1.06$

Wherein, Y is an imaging end diagonal angle maximum length, and L is described zoom lens total length, f _WBe the focal length of described zoom lens in wide-angle side, f _TBe the focal length of described zoom lens in the journey of looking in the distance.

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