CN1576942A

CN1576942A - Zoom lens system

Info

Publication number: CN1576942A
Application number: CNA2004100636831A
Authority: CN
Inventors: 泉水隆之
Original assignee: Nikon Corp
Current assignee: Nikon Corp
Priority date: 2003-07-17
Filing date: 2004-07-16
Publication date: 2005-02-09
Anticipated expiration: 2024-07-16
Also published as: CN100374897C; CN101231381A; CN101231381B

Abstract

A super-wide zoom lens system having sufficient zoom ratio and a high speed, capable of obtaining high optical performance. The system includes at least, in order from an object, a first lens group G1 having negative refractive power, and a second lens group G2 having positive refractive power. When zooming from a wide-angle end state to a telephoto end state, a distance between the first lens group G1 and the second lens group G2 varies. The first lens group G1 includes at least one negative lens element and a glass material constructing at least one negative lens element in the first group G1 satisfies given conditions.

Description

Zoom-lens system

Technical field

The present invention relates to a kind of zoom-lens system, and relate in particular to a kind of zoom-lens system that is applicable to the simple lens reflective camera, this camera has 75 ° or bigger visual angle and the zoom ratio that is not less than 3 at wide-angle end.

Background technology

There is the zoom-lens system (so-called negative leading type zoom lens) of negative lens group to be easy to make wide-angle lens in the most close thing side various imaginations have also been arranged.On the other hand, negative leading type zoom lens have a shortcoming, promptly are difficult to satisfy high zoom ratios and high-speed.Therefore, the high speed zoom lens of this shortcoming for example in Japan patented claim JP2000-241704 undetermined and 2000-221399, have been proposed to overcome.

But the zoom lens that these patent documents propose can not satisfy wide visual angle and the high zoom ratios in the wide-angle end.

Summary of the invention

Formulated the present invention in view of the above problems, and the object of the present invention is to provide and a kind ofly can obtain the when high-speed super wide zoom lens system of the enough zooms of having of good optical performance.

According to an aspect of the present invention, zoom-lens system comprises from the thing side: first lens combination and second lens combination with positive refraction focal power with negative refraction focal power.When the location status of lens combination when wide-angle end changes to telephoto end, each lens combination all moves, and the distance of winning between the lens combination and second lens combination is changed.First lens combination comprises a negative lens element at least.At least the glass material that constitutes a negative lens element at least one negative lens element in first lens combination satisfies following three conditional expressions (1), (2) and (3):

67.0＜v (1)

1.40＜N (2)

0＜N+0.0032×v-1.734 (3)

Herein, v represents that (Abbe number of λ=587.6nm) locate, N represent that glass material is in the d line (refractive index of λ=587.6nm) locate to glass material at the d line.

In a preferred embodiment of the invention, zoom-lens system also comprises from the thing side: be positioned at second lens combination as the 3rd lens combination with negative refraction focal power of side with have the 4th lens combination of positive refraction focal power.When the location status of lens combination when wide-angle end changes to telephoto end, each lens combination all moves, the distance of winning between the lens combination and second lens combination is reduced, distance between second lens combination and the 3rd lens combination increases, and the distance between the 3rd lens combination and the 4th lens combination reduces.The 4th lens combination comprises a positive element at least, and the glass material that constitutes a positive element of at least one positive element in the 4th lens combination at least satisfies following three conditional expressions (1), (2) and (3):

67.0＜v (1)

1.40＜N (2)

0＜N+0.0032×v-1.734 (3)

In a preferred embodiment of the invention, preferably satisfy following conditional expression (4):

1.5＜(-f1)/fw＜2.3 (4)

Herein, f1 represents the focal length of first lens combination in the wide-angle end, and fw represents the focal length of zoom-lens system in the wide-angle end.

In a preferred embodiment of the invention, preferably satisfy following conditional expression (5):

0.75＜f2/(fw×ft) ^1/2＜1.6 (5)

Herein, f2 represents the focal length of second lens combination, and fw represents the focal length of zoom-lens system in the wide-angle end, and ft represents the focal length of zoom-lens system in the telephoto end.

In a preferred embodiment of the invention, preferably satisfy following conditional expression (6) and (7):

0.6＜(-f3)/f2＜1.2 (6)

0.8＜f4/(fw×ft) ^1/2＜2.0 (7)

Herein, f3 represents the focal length of the 3rd lens combination, and f4 represents the focal length of the 4th lens combination.

In a preferred embodiment of the invention, at least one lens element with negative refraction focal power that concave surface faces image in first lens combination has the aspheric surface of negative refraction focal power, wherein along with the distance of this aspheric surface apart from optical axis increases, the negative refraction focal power dies down.

In a preferred embodiment of the invention, the negative lens element that satisfies all three conditional expressions in first lens combination is the concave-concave shape.

In a preferred embodiment of the invention, first lens combination comprises negative lens element and other lens element that is made of the glass material that satisfies all three conditional expressions, and this negative lens element and other lens element gummed.

In a preferred embodiment of the invention, the location status of lens combination changes to telephoto end from wide-angle end, forms between each lens element of first lens combination and all fixes along the distance of optical axis.

In a preferred embodiment of the invention, first lens combination is made up of first sub-lens group with negative refraction focal power and the second sub-lens group with negative refraction focal power from the thing side, and when the location status of lens combination when wide-angle end changes to telephoto end, the distance between the first sub-lens group and the second sub-lens group changes.

By below in conjunction with the accompanying drawing detailed description of the preferred embodiment, will be more readily understood other characteristics of the present invention and advantage.

Description of drawings

Fig. 1 is the mobile sketch of zoom-lens system lens combination when the lens of wide-angle end (W), middle parfocal attitude (M) and telephoto end (T) formation and zoom of expression example 1 according to the present invention;

Fig. 2 A, 2B and 2C are in the various aberrations of zoom-lens system when focusing on infinity of wide-angle end, middle parfocal attitude and telephoto end respectively according to example 1 with curve representation;

Fig. 3 is that the lens of the zoom-lens system of example 2 according to the present invention constitute sketch;

Fig. 4 A, 4B and 4C are with the various aberrations of the zoom-lens system that is in wide-angle end, middle parfocal attitude and telephoto end in the curve representation example 2 respectively when focusing on infinity;

Fig. 5 is that the lens of the zoom-lens system of example 3 according to the present invention constitute sketch;

Fig. 6 A, 6B and 6C are with the various aberrations of the zoom-lens system that is in wide-angle end, middle parfocal attitude and telephoto end in the curve representation example 3 respectively when focusing on infinity;

Fig. 7 is that the lens of the zoom-lens system of example 4 according to the present invention constitute sketch;

Fig. 8 A, 8B and 8C are with the various aberrations of the zoom-lens system that is in wide-angle end, middle parfocal attitude and telephoto end in the curve representation example 4 respectively when focusing on infinity;

Fig. 9 is that the lens of the zoom-lens system of example 5 according to the present invention constitute sketch;

Figure 10 A, 10B and 10C are with the various aberrations of the zoom-lens system that is in wide-angle end, middle parfocal attitude and telephoto end in the curve representation example 5 respectively when focusing on infinity;

Figure 11 is that the lens of the zoom-lens system of example 6 according to the present invention constitute sketch;

Figure 12 A, 12B and 12C are with the various aberrations of the zoom-lens system that is in wide-angle end, middle parfocal attitude and telephoto end in the curve representation example 6 respectively when focusing on infinity;

Figure 13 is that the lens of the zoom-lens system of example 7 according to the present invention constitute sketch;

Figure 14 A, 14B and 14C are with the various aberrations of the zoom-lens system that is in wide-angle end, middle parfocal attitude and telephoto end in the curve representation example 7 respectively when focusing on infinity;

Figure 15 is that the lens of the zoom-lens system of example 8 according to the present invention constitute sketch;

Figure 16 A, 16B and 16C are with the various aberrations of the zoom-lens system that is in wide-angle end, middle parfocal attitude and telephoto end in the curve representation example 8 respectively when focusing on infinity;

Figure 17 is that the lens of the zoom-lens system of example 9 according to the present invention constitute sketch;

Figure 18 A, 18B and 18C are with the various aberrations of the zoom-lens system that is in wide-angle end, middle parfocal attitude and telephoto end in the curve representation example 9 respectively when focusing on infinity;

Figure 19 is that the lens of the zoom-lens system of example 10 according to the present invention constitute sketch;

Figure 20 A, 20B and 20C are with the various aberrations of the zoom-lens system that is in wide-angle end, middle parfocal attitude and telephoto end in the curve representation example 10 respectively when focusing on infinity;

Figure 21 is that the lens of the zoom-lens system of example 11 according to the present invention constitute sketch;

Figure 22 A, 22B and 22C are with the various aberrations of the zoom-lens system that is in wide-angle end, middle parfocal attitude and telephoto end in the curve representation example 11 respectively when focusing on infinity.

Embodiment

Zoom-lens system according to the present invention comprises from the thing side: have first lens combination of negative refraction focal power, have second lens combination of positive refraction focal power, have the 3rd lens combination of negative refraction focal power and have the 4th lens combination of positive refraction focal power.When the location status of lens combination when wide-angle end changes to telephoto end, each lens combination all moves, the distance of winning between the lens combination and second lens combination is reduced, distance between second lens combination and the 3rd lens combination increases, and the distance between the 3rd lens combination and the 4th lens combination reduces.

The glass material that constitutes at least one negative lens element in first lens combination and constitute at least one positive element in the 4th lens combination satisfies following three conditional expressions (1), (2) and (3):

67.0＜v (1)

1.40＜N (2)

0＜N+0.0032×v-1.734 (3)

In zoom-lens system according to the present invention, because the bottom light in axial ray is by around the above-mentioned negative lens, so, can well proofread and correct the colored coma of bottom light by constitute at least one negative lens element in first lens combination with the glass material that satisfies above-mentioned conditional expression.Image height is timing, and bottom light is the light that is lower than chief ray, and top light is the light that is higher than chief ray.

Above-mentioned conditional expression (1), (2) and (3) are refractive index and the Abbe numbers that is used for suitably being provided with the glass material that constitutes first at least one negative lens element of lens combination.

When the glass material of at least one negative lens element did not satisfy in the above-mentioned conditional expression any one in constituting first lens combination, barrel distortion and lateral chromatic aberration became and are difficult to balance correction well in the wide-angle end.And in wide-angle end, colored coma is created in bottom light one side.

In zoom-lens system according to the present invention, because the top light in axial ray is by around the above-mentioned positive lens, so, can well proofread and correct the colored coma of top light by constitute at least one positive element in the 4th lens combination with the glass material that satisfies above-mentioned conditional expression.

Above-mentioned conditional expression (1), (2) and (3) are refractive index and the Abbe numbers that is used for suitably being provided with the glass material that constitutes the 4th at least one positive element of lens combination.

When the glass material of at least one positive element did not satisfy in the above-mentioned conditional expression any one in constituting the 4th lens combination, coaxial aberration and various aberration became and are difficult to balance correction well in the telephoto end.And in wide-angle end, colored coma is created in top light one side.

And the glass material that constitutes at least one negative lens element in first lens combination preferably satisfies following conditional expression (1a), (2) and (3a):

67.0＜v＜104.0 (1a)

1.0＜N (2)

0＜N+0.0122×v-2.5188(3a)

And the glass material that constitutes at least one positive element in the 4th lens combination preferably satisfies following conditional expression (1a), (2) and (3a):

67.0＜v＜104.0 (1a)

1.40＜N (2)

0＜N+0.0122×v-2.5188(3a)

In addition, zoom-lens system preferably according to the present invention satisfies following conditional expression (4):

1.5＜(-f1)/fw＜2.3 (4)

In addition, zoom-lens system preferably according to the present invention satisfies following conditional expression (5):

0.75＜f2/(fw×ft) ^1/2＜1.6 (5)

Conditional expression (4) is used for being provided with the proper range of the focal length of wide-angle end first lens combination.

When (f1)/and fw ratio equals or exceeds going up in limited time of conditional expression (4), and the focal length of first lens combination becomes oversize in the wide-angle end, makes to be difficult to the diameter of the front lens diameter of thing side lens element (be positioned at) is minimized.

On the other hand, when above-mentioned ratio equals or drops on the lower limit of conditional expression (4) when following, the focal length of first lens combination becomes too short in the wide-angle end, makes to be difficult to proofread and correct distortion, coma and field curvature in the wide-angle end.Therefore, be difficult to become the formula of dolly-out,ing dolly-back in the telephoto end, so that be difficult to guarantee the f number in the telephoto end according to the optical power profile of zoom-lens system of the present invention.

Conditional expression (5) is used for suitably being provided with the focal length of second lens combination.

As f2/ (fw * ft) ^1/2Ratio equals or exceeds going up in limited time of conditional expression (5), and the focal length of second lens combination becomes oversize, and is so that the amount of movement of second lens combination when zoom becomes long, very undesirable.And the diameter of aperture diaphragm becomes too big in the telephoto end, has increased the diameter of lens drum, and is also very undesirable.

On the other hand, when this ratio equals or drops on the lower limit of conditional expression (5) when following, the focal length of second lens combination becomes too short, so that be difficult to proofread and correct the spherical aberration in coma, the especially telephoto end.

In zoom-lens system according to the present invention, preferably satisfy following conditional expression (6) and (7):

0.6＜(-f3)/f2＜1.2 (6)

0.8＜f4/(fw×ft) ^1/2＜2.0 (7)

Conditional expression (6) defines the focal length of second lens combination and the proper range of the ratio of the focal length of the 3rd lens combination, is used to guarantee the back focal length and the good optical performance of zoom-lens system of the present invention.

When ratio (f3)/f2 equals or exceeds going up in limited time of conditional expression (6), the focal length of the 3rd lens combination becomes long with respect to the focal length of second lens combination, so that be difficult to guarantee the back focal length in wide-angle end.

On the other hand, when above-mentioned ratio equals or drops on the lower limit of conditional expression (6) when following, the focal length of the 3rd lens combination becomes too short with respect to the focal length of second lens combination, produces a large amount of spherical aberration, coma and distortion in the 3rd lens combination, so that be difficult to proofread and correct these aberrations well balancedly.

Conditional expression (7) is used for suitably being provided with the focal length of the 4th lens combination.

As f4/ (fw * ft) ^1/2Ratio equals or exceeds going up in limited time of conditional expression (7), and the focal length of the 4th lens combination becomes oversize, so that be difficult to guarantee the back focal length in wide-angle end and guarantee enough zoom ratios.

On the other hand, when above-mentioned ratio equals or drops on the lower limit of conditional expression (7) when following, it is too short that the focal length of the 4th lens combination becomes, and produces a large amount of aberrations during zoom and change, so that be difficult to proofread and correct aberration on the whole zooming range.

In zoom-lens system according to the present invention, what at least one had a negative refraction focal power in preferred first lens combination has aspheric surface with concave surface towards the lens element as side, and this aspheric negative refraction focal power increases along with the distance of this surface lies optical axis and dies down.

In zoom-lens system according to the present invention, in order to ensure enough back focal length and prevent that the diameter of front lens from becoming big, although make the refractive optical power of first lens combination become big effectively, also produces a large amount of barrel distortion.Therefore, in zoom-lens system of the present invention, in first lens combination aspheric surface is arranged to the concavees lens surface towards the picture side, so the curvature of lens surface can be less than the curvature of benchmark sphere.And aspheric introduction produces a spot of spherical aberration and distortion, so that can alleviate burden to the aberration correction of back lens element (being positioned at the lens element of aspheric surface) as side, thereby very undesirable.

In zoom-lens system according to the present invention, the negative lens element that satisfies all three conditional expressions (1), (2) and (3) in preferred first lens combination has the concave-concave shape.Usually, glass material is very soft, easily deformable on hardness, so that preferred concave-concave shape can reduce distortion.

And, in zoom-lens system according to the present invention, preferably when the location status of lens combination when wide-angle end changes to telephoto end, form between each lens element of first lens combination fixed distance along optical axis.In this structure, preferably this structure can be simplified, and the aberration during zoom becomes very little.

In addition, in zoom-lens system according to the present invention, preferred first lens combination is made up of first sub-lens group with negative refraction focal power and the second sub-lens group with negative refraction focal power from the thing side, and when the location status of lens combination when wide-angle end changes to telephoto end, the distance between the first sub-lens group and the second sub-lens group changes.In this structure, the variation of aberration is not subjected to too many influence and is easy to proofread and correct therefore preferred this structure during zoom.

Explain each example of the present invention below with reference to accompanying drawing.

＜example 1 〉

Fig. 1 is the mobile sketch of zoom-lens system lens combination when the lens of wide-angle end (W), middle parfocal attitude (M) and telephoto end (T) formation and zoom of expression example 1 according to the present invention.

As shown in Figure 1, the zoom-lens system according to example 1 comprises from the thing side: have the negative refraction focal power the first lens combination G1, have the second lens combination G2 of positive refraction focal power, the 4th lens combination G4 that has the 3rd lens combination G3 of negative refraction focal power and have the positive refraction focal power.When the location status of lens combination when wide-angle end changes to telephoto end, each lens combination all moves, so that the distance between the first lens combination G1 and the second lens combination G2 reduces, distance between the second lens combination G2 and the 3rd lens combination G3 increases, and the distance between the 3rd lens combination G3 and the 4th lens combination G4 reduces.

Between the second lens combination G2 and the 3rd lens combination G3, arrange aperture diaphragm S, and aperture diaphragm S moves when being configured to zoom along optical axis with the 3rd lens combination G3.

Therefore above-mentioned feature all is the same for all following examples, saves the description of repetition below in the introduction of example.

In zoom-lens system according to example 1, from the second negative lens SL1 of the first lens combination G1 thing side and from the first positive lens SL2 of the 4th lens combination G4 thing side and the 3rd positive lens SL3 by satisfying above-mentioned conditional expression (1), the glass material of (2) and (3) (being called " specific glass " herein) is made.The negative lens SL1 that makes by specific glass be the concave-concave shape and with the 3rd lens gummed from thing side number.When the location status of lens combination when wide-angle end changes to telephoto end, form between each lens element of first lens combination fixed distance along optical axis.This structure all is identical for following example 2～example 10, therefore saves identical description in the introduction of example below.

In zoom-lens system according to example 1, by carrying out from unlimited focusing as far as near object as first lens and a balsaming lens that the mobile integratedly second lens combination G2 thing side of side rises along optical axis direction, wherein said balsaming lens is formed by second lens and the 3rd lens gummed that the second lens combination G2 thing side rises.

Tabulate down every value according to the zoom-lens system of example 1 has been shown in 1.In [specification] hurdle, f represents focal length, and FNO represents the f number, and 2A represents the visual angle, and BF represents back focal length.

In [lens data] hurdle, the first from left hurdle is represented from the surperficial number of the lens surface of thing side number, the r table is the radius-of-curvature of lens, d represents between the lens surface distance along optical axis, N represents that (refractive index of λ=587.56nm) locate, v represents that medium between the lens surface is at the d line (Abbe number of λ=587.56nm) locate at the d line for medium between the lens surface.

In the zoom-lens system of each example according to the present invention, aspheric surface is represented by following expression formula:

x＝cy ²/[1+(1-kc ²y ²) ^1/2]+C4·y ⁴+C6·y ⁶+C8·y ⁸+C10·y ¹⁰+C12·y ¹²

Herein, y represents the height apart from optical axis, and x represents amount of recess, and c represents the radius-of-curvature (paraxial radius-of-curvature) of benchmark sphere, and k represents conical surface coefficient, and C4, C6, C8, C10 and C12 represent the 4th, the 6th, the 8th, the 10th and the 12nd rank asphericity coefficient respectively.

Aspheric surface by be connected in surperficial number " ^*" be illustrated in [lens data] hurdle, paraxial radius-of-curvature is listed in the radius-of-curvature row " r ".In [aspherical surface data], show conical surface coefficient " k " and each asphericity coefficient.In [aspherical surface data], " E-n " expression " 10 ^-n".For example, " 1.234E-05 " expression " 1.234 * 10 ^-5".

In " magnification of each block of lense ", β represents the imaging magnification between thing and the picture." 1-POS " expression system focuses on infinity in wide-angle end, in " 2-POS " expression in the parfocal attitude system focus on infinity, " 3-POS " expression system focuses on infinity in telephoto end, " 4-POS " expression system focuses on β=-0.02500 in wide-angle end, " 5-POS " expression system focuses on β=-0.02500 in middle parfocal attitude, " 6-POS " expression system focuses on β=-0.02500 in telephoto end, " 7-POS " expression system focuses near object in wide-angle end, in " 8-POS " expression in the parfocal attitude system focus near object, " 9-POS " expression system focuses near object in telephoto end.The block of lense that " B (m-n) " expression is formed by the lens element between m lens surface and n lens surface.

In the table of every value, " mm " is generally as the unit at the interval between length such as focal length, radius-of-curvature and the optical surface etc.But,, can adopt any other suitable unit so unit needn't be defined as " mm " because the optical system of proportional amplification or minification can obtain same optical property.

The explanation of label is all identical in other example.

Table 1

[specification]

Wide-angle is medium dolly-out,s dolly-back

f＝16.5 30.67 49.5

2A＝86.8 51.1 33.1°

FNO＝2.89

[lens data]

Surface number r d N v

1) 76.2729 2.5000 1.744429 49.52

^*2) 23.2876 22.7082

3) -64.3264 1.3000 1.592400 68.33?SL1

4) 94.5578 2.9406 1.805180 25.43

5) 2047.8525 D5

^*6) 212.8974 3.1597 1.677900 55.34

7) -110.2891 0.1000

8) 122.3160 1.0000 1.846660 23.78

9) 34.9545 5.0514 1.618000 63.38

10) -171.3120 0.9881

^*11) 50.7936 5.3000 1.739929 49.25

12) -290.3704 D12

13＞1.2000 aperture diaphragm S

14) 185.3843 3.7000 1.846660 23.78

15) -28.5773 1.0000 1.804000 46.58

16) 110.0860 1.9000

17) -41.1906 1.0000 1.804000 46.58

18) 84.5433 D18

19) -115.2418 5.0000 1.569070 71.31?SL2

20) -34.7029 0.1000

21) -1329.5201 4.0000 1.618000 63.38

22) -42.2832 0.1000

23) 48.4541 5.3788 1.497820 82.52?SL3

24) -32.1426 1.0000 1.846660 23.78

25)-732.5906

[aspherical surface data]

Surface several 2

κ＝0.0000

C4＝4.05250E-06

C6＝6.11040E-10

C8＝8.18800E-12

C10＝-1.46560E-14

C12＝0.11470E-16

Surface several 6

κ＝1.0000

C4＝-2.09280E-06

C6＝1.24370E-09

C8＝1.65820E-12

C10＝0.00000E+00

Surface several 11

κ＝1.0000

C4＝1.82870E-06

C6＝-7.99320E-10

C8＝5.20040E-13

C10＝-1.71450E-15

[variable interval]

Wide-angle is medium dolly-out,s dolly-back

D5 43.77360 14.31030 2.37600

D12 1.35000 14.04720 25.98790

D18 18.19420 11.45430 3.46290

[magnification of each block of lense]

1-POS 2-POS 3-POS

B(1-5) 0.00000 0.00000 0.00000

B(6-10) -4.23522 6.58245 3.23525

B(11-12) 0.13138 -0.15738 -0.49191

B(13-18) -4.41877 -2.81762 -1.70363

B(19-25) -0.21883 -0.34259 -0.59534

4-POS 5-POS 6-POS

β -0.02500 -0.02500 -0.02500

B(1-5) 0.04712 0.02509 0.01550

B(6-10) -4.21836 6.59060 3.24195

B(11-12) 0.13131 -0.15745 -0.49197

B(13-18) -4.41638 -2.81665 -1.70331

B(19-25) -0.21893 -0.34269 -0.59544

7-POS 8-POS 9-POS

β -0.062 -0.1100 -0.180

B(1-5) 0.11999 0.11168 0.11218

B(6-10) -4.20477 6.58519 3.27364

B(11-12) 0.13094 -0.15875 -0.49523

B(13-18) -4.40373 -2.79858 -1.68681

B(19-25) -0.21949 -0.34464 -0.60085

Fig. 2 A, 2B and 2C are with the various aberrations of the zoom-lens system that is in wide-angle end, middle parfocal attitude and telephoto end in the curve representation example 1 when focusing on infinity.

In each curve, FNO represents the f number, and A represents half angle of view (unit: °).In the curve of expression astigmatism and distortion, show the maximal value A of half angle of view.And " d " and " g " is illustrated respectively in d line (λ=587.6nm) and the g line (aberration of λ=435.8nm).

In the curve of expression spherical aberration, FNO represents maximum aperture value.In the curve of expression astigmatism, solid line is represented picture arrow face, and dotted line is represented as meridional plane.

In the curve of expression coma, show half angle of view A.Above-mentioned explanation about each aberration curve also is the same for other example.

Obvious from each bar curve, as result, show fabulous optical property according to the zoom-lens system of example 1 to the well-corrected of aberration in every kind of focal length attitude (wide-angle end, middle parfocal attitude and telephoto end).

＜example 2 〉

Fig. 3 is that the lens of the zoom-lens system of example 2 according to the present invention constitute sketch.By the way, the accompanying drawing of the lens arrangement of following each example of expression has only been represented the situation of wide-angle end (W).

In zoom-lens system, make by specific glass from the 3rd negative lens SL1 of the first lens combination G1 thing side with from the second positive lens SL2 and the 3rd positive lens SL3 of the 4th lens combination G4 thing side according to example 2.The negative lens SL1 that is made by specific glass is the concave-concave shape.

In zoom-lens system according to example 2, by carrying out from unlimited focusing as far as near object as first lens and a balsaming lens that the mobile integratedly second lens combination G2 thing side of side rises along optical axis direction, wherein said balsaming lens is formed by second lens and the 3rd lens gummed that the second lens combination G2 thing side rises.

Tabulate down every value according to the zoom-lens system of example 2 has been shown in 2.

Table 2

[specification]

Wide-angle is medium dolly-out,s dolly-back

f＝17.55 - 30.81 - 53.4

2A＝83.38 51.18 30.96°

FNO＝2.89

[lens data]

Surface number r d N v

1) 43.0102 2.0000 1.620410 60.29

2) 21.3899 11.2854

3) 59.7338 2.0000 1.744429 49.55

^*4) 32.3245 8.1026

5) -65.6686 1.3000 1.569070 71.31?SL1

6) 96.9021 0.2000

7) 69.0297 3.3904 1.805180 25.43

8) 426.3566 D8

^*9) 92.4945 3.4356 1.677900 55.34

10) -186.1620 0.1000

11) -1876.6557 1.0000 1.805180 25.43

12) 38.6412 6.0000 1.640000 59.69

13) -79.2843 1.0018

^*14) 49.2354 5.9545 1.637055 58.25

15) -123.3871 D15

16＞1.2000 aperture diaphragm S

17) 121.9585 3.6731 1.846660 23.78

18) -31.0894 1.0000 1.804000 46.58

19) 35.1118 3.2174

20) -26.8809 1.0000 1.804000 46.58

21) -65.7049 D21

22) -197.0467 4.6157 1.618000 63.38

23) -32.6618 0.1000

24) 173.9124 2.3568 1.497820 82.52 SL2

25) -118.9824 0.1000

26) 89.9876 5.0362 1.497820 82.52 SL3

27) -27.9105 1.0000 1.846660 23.78

28) -77.7117

[aspherical surface data]

Surface several 4

κ＝0.0000

C4＝-2.80900E-06

C6＝-7.05870E-09

C8＝1.85210E-11

C10＝-7.69200E-14

C12＝0.54670E-16

Surface several 9

κ＝1.0000

C4＝-3.21370E-06

C6＝3.94540E-09

C8＝-7.52750E-13

C10＝0.00000E+00

Surface several 14

κ＝1.0000

C4＝1.20020E-06

C6＝-2.72780E-09

C8＝2.23320E-12

C10＝-3.44650E-15

[variable interval]

Wide-angle is medium dolly-out,s dolly-back

D8 43.73070 16.11230 1.75000

D15 1.35000 12.50760 25.54550

D21 18.86450 14.53890 5.68120

[magnification of each block of lense]

1-POS 2-POS 3-POS

B(1-8) 0.00000 0.00000 0.00000

B(9-13) -3.50130 9.83804 3.30002

B(14-15) 0.15216 -0.09599 -0.47835

B(16-21) -4.93806 -3.44613 -1.79102

B(22-28) -0.21648 -0.30726 -0.61284

4-POS 5-POS 6-POS

β -0.02500 -0.02500 -0.02500

B(1-8) 0.04455 0.02510 0.01444

B(9-13) -3.48253 9.84378 3.30667

B(14-15) 0.15210 -0.09605 -0.47840

B(16-21) -4.93546 -3.44484 -1.79070

B(22-28) -0.21658 -0.30736 -0.61294

7-POS 8-POS 9-POS

β -0.066 -0.111 -0.195

B(1-8) 0.12046 0.11279 0.11330

B(9-13) -3.46019 9.78411 3.34074

B(14-15) 0.15174 -0.09720 -0.48185

B(16-21) -4.91969 -3.42048 -1.77110

B(22-28) -0.21720 -0.30930 -0.61916

Fig. 4 A, 4B and 4C are with the various aberrations of the zoom-lens system that is in wide-angle end, middle parfocal attitude and telephoto end in the curve representation example 2 respectively when focusing on infinity.

Obvious from each bar curve, as result, show fabulous optical property according to the zoom-lens system of example 2 to the well-corrected of aberration in every kind of focal length attitude (wide-angle end, middle parfocal attitude and telephoto end).

＜example 3 〉

Fig. 5 is that the lens of the zoom-lens system of example 3 according to the present invention constitute sketch.

In zoom-lens system, make by specific glass from the 3rd negative lens SL1 of the first lens combination G1 thing side with from the first positive lens SL2 and the 3rd positive lens SL3 of the 4th lens combination G4 thing side according to example 3.The negative lens SL1 that is made by specific glass is the concave-concave shape, and with from the 4th lens of thing side number gummed.

In zoom-lens system, by moving the balsaming lens that first lens that risen by the second lens combination G2 thing side and second lens gummed form along optical axis direction as side integratedly and gluing together a balsaming lens that forms by the 3rd lens that the second lens combination G2 thing side rises with the 4th lens and carry out from unlimited focusing as far as near object according to example 3.

Tabulate down every value according to the zoom-lens system of example 3 has been shown in 3.

Table 3

[specification]

Wide-angle is medium dolly-out,s dolly-back

f＝17.55 - 29.61 - 53.4

2A＝83.36 - 53.34 - 31.1°

FNO＝2.89

[lens data]

Surface number r d N v

1) 41.7490 2.0000 1.799520 42.24

2) 22.5226 14.4873

3) 74.2071 2.0000 1.796681 45.37

^*4) 38.7933 8.0658

5) -92.4063 1.3000 1.569070 71.31?SL1

6) 58.4359 3.7360 1.846660 23.78

7) 289.3259 D7

8) 180.6275 4.2583 1.696800 55.52

9) -50.6496 1.0000 1.846660 23.78

10) -80.4575 0.1000

11) 41.9083 1.0000 1.846660 23.78

12) 25.4611 6.0000 1.487490 70.24

13) 157.3587 1.0024

^*14) 43.2622 5.7575 1.713000 53.85

15) -259.6633 D15

16＞1.2000 aperture diaphragm S

17) 128.9726 4.3615 1.846660 23.78

18) -24.3308 1.0000 1.804000 46.58

19) 49.4407 2.5995

20) -31.3713 1.0000 1.804000 46.58

21) 115.9859 D21

22) 368.8076 5.0000 1.497820 82.52?SL2

23) -28.1873 0.1000

24) 159.2657 2.7000 1.618000 63.38

25) -123.3241 0.1000

26) 65.0663 5.7301 1.497820 82.52?SL3

27) -28.1289 1.0000 1.846660 23.78

28) -106.6177

[aspherical surface data]

Surface several 4

κ＝0.0000

C4＝-3.19380E-06

C6＝-4.94320E-09

C8＝7.51060E-13

C10＝-1.32410E-14

C12＝-0.44693E-17

Surface several 14

κ＝1.0000

C4＝1.00000E-08

C6＝3.75250E-10

C8＝1.08920E-12

C10＝0.00000E+00

[variable interval]

Wide-angle is medium dolly-out,s dolly-back

D7 39.33590 16.23690 1.75000

D15 1.35000 10.85920 22.23130

D21 17.07340 12.51060 5.52610

[magnification of each block of lense]

1-POS 2-POS 3-POS

B(1-7) 0.00000 0.00000 0.00000

B(8-13) -3.80389 12.59026 3.40003

B(14-15) 0.14366 -0.07072 -0.43257

B(16-21) -2.78220 -2.33000 -1.35946

B(22-28) -0.38982 -0.48203 -0.90196

4-POS 5-POS 6-POS

β -0.02500 -0.02500 -0.02500

B(1-7) 0.04277 0.02511 0.01387

B(8-13) -3.78623 12.59237 3.40648

B(14-15) 0.14360 -0.07077 -0.43262

B(16-21) -2.78119 -2.32934 -1.35927

B(22-28) -0.38994 -0.48215 -0.90208

7-POS 8-POS 9-POS

β -0.066 -0.107 -0.197

B(1-7) 0.11503 0.10862 0.10999

B(8-13) -3.76723 12.47409 3.43905

B(14-15) 0.14323 -0.07178 -0.43562

B(16-21) -2.77512 -2.31783 -1.34763

B(22-28) -0.39065 -0.48422 -0.90944

Fig. 6 A, 6B and 6C are with the various aberrations of the zoom-lens system that is in wide-angle end, middle parfocal attitude and telephoto end in the curve representation example 3 respectively when focusing on infinity.

Obvious from each bar curve, as result, show fabulous optical property according to the zoom-lens system of example 3 to the well-corrected of aberration in every kind of focal length attitude (wide-angle end, middle parfocal attitude and telephoto end).

＜example 4 〉

Fig. 7 is that the lens of the zoom-lens system of example 4 according to the present invention constitute sketch.

In zoom-lens system, make by specific glass from the 3rd negative lens SL1 of the first lens combination G1 thing side with from the first positive lens SL2 and the 3rd positive lens SL3 of the 4th lens combination G4 thing side according to example 4.The negative lens SL1 that is made by specific glass is the concave-concave shape, and with from the 4th lens of thing side number gummed.

In the zoom-lens system according to example 4, balsaming lens by moving integratedly as side along optical axis direction that first lens that risen by the second lens combination G2 thing side and second lens gummed form and the 3rd lens that risen by the second lens combination G2 thing side and the 4th lens glue together and form a balsaming lens and carry out from unlimited focusing as far as near object.

Tabulate down every value according to the zoom-lens system of example 4 has been shown in 4.

Table 4

[specification]

Wide-angle is medium dolly-out,s dolly-back

f＝17.55 - 30.79 - 53.4

2A＝83.34 - 51.24 - 30.98°

FNO＝2.89

[lens data]

Surface number r d N v

1) 40.9179 2.0000 1.806100 40.94

2) 21.9529 14.9387

3) 85.5860 2.0000 1.796681 45.37

^*4) 41.8649 6.6331

5) -88.8627 1.3000 1.569070 71.31?SL1

6) 79.4414 3.4131 1.846660 23.78

7) 4482.0238 D7

8) 265.6240 4.1124 1.696800 55.52

9) -53.0226 1.0000 1.805180 25.43

10) -85.4782 0.1000

11) 48.4579 1.0000 1.846660 23.78

12) 28.3332 6.0000 1.487490 70.24

13) 609.7882 1.0047

14) 44.0030 5.8155 1.696800 55.52

15) -207.9680 D15

16＞1.2000 aperture diaphragm S

17) 132.9964 4.2981 1.846660 23.78

18) -24.6683 1.0000 1.804000 46.58

19) 52.5868 2.6051

20) -31.0252 1.0000 1.804000 46.58

21) 108.4429 D21

22) 1202.2229 5.0000 1.49780 82.52?SL2

23) -26.9875 0.1000

24) 152.4677 2.7000 1.618000 63.38

25) -129.6517 0.1000

26) 54.2036 6.0000 1.497820 82.52?SL3

27) -30.0273 1.0000 1.846660 23.78

28) -162.9006

[aspherical surface data]

Surface several 4

κ＝0.0000

C4＝-4.05780E-06

C6＝-3.17270E-09

C8＝-1.99470E-11

C10＝5.77110E-14

C12＝-0.94474E-16

[variable interval]

Wide-angle is medium dolly-out,s dolly-back

D7 40.95880 15.53650 1.75000

D15 1.35000 12.25530 23.90170

D21 17.41550 13.09280 6.05810

[magnification of each block of lense]

1-POS 2-POS 3-POS

B(1-7) 0.00000 0.00000 0.00000

B(8-13) -3.82942 10.11327 3.40001

B(14-15) 0.13758 -0.08740 -0.41103

B(16-21) -2.61985 -2.38465 -1.57100

B(22-28) -0.41289 -0.47443 -0.78981

4-POS 5-POS 6-POS

β -0.02500 -O.02500 -0.02500

B(1-7) 0.04449 0.025?10 0.01443

B(8-13) -3.81121 10.11878 3.40667

B(14-15) 0.13752 -0.08746 -0.41108

B(16-21) -2.61895 -2.38397 -1.57075

B(22-28) -0.41301 -0.47455 -0.78993

7-POS 8-POS 9-POS

β -0.066 -0.111 -0.195

B(1-7) 0.12027 0.11285 0.11327

B(8-13) -3.79169 10.05288 3.44006

B(14-15) 0.13714 -0.08853 -0.41394

B(16-21) -2.61348 -2.37106 -1.55587

B(22-28) -0.41373 -0.47678 -0.79712

Fig. 8 A, 8B and 8C are with the various aberrations of the zoom-lens system that is in wide-angle end, middle parfocal attitude and telephoto end in the curve representation example 4 respectively when focusing on infinity.

Obvious from each bar curve, as result, show fabulous optical property according to the zoom-lens system of example 4 to the well-corrected of aberration in every kind of focal length attitude (wide-angle end, middle parfocal attitude and telephoto end).

＜example 5 〉

Fig. 9 is that the lens of the zoom-lens system of example 5 according to the present invention constitute sketch.

In zoom-lens system, make by specific glass from the second negative lens SL1 of the first lens combination G1 thing side with from the first positive lens SL2 and the 3rd positive lens SL3 of the 4th lens combination G4 thing side according to example 5.The negative lens SL1 that is made by specific glass is the concave-concave shape, and with the 3rd lens gummed of thing side number.

In zoom-lens system according to example 5, by carrying out from unlimited focusing as far as near object as first lens and a balsaming lens that the mobile integratedly second lens combination G2 thing side of side rises along optical axis direction, wherein said balsaming lens is formed by second lens and the 3rd lens gummed that the second lens combination G2 thing side rises.

Tabulate down every value according to the zoom-lens system of example 5 has been shown in 5.

Table 5

[specification]

Wide-angle is medium dolly-out,s dolly-back

f＝17.55 - 31.43 - 52.7

2A＝83.30 - 50.04 - 31.16°

FNO＝2.89

[lens data]

Surface number r d N v

1) 68.8329 2.5000 1.744429 49.55

^*2) 23.7109 22.4287

3) -58.4517 1.3000 1.518601 69.98?SL1

4) 70.0469 2.9936 1.805180 25.43

5) 243.9094 D5

^*6) 140.0441 3.4072 1.677900 55.34

7) -118.9794 0.1000

8) 124.6930 1.0000 1.846660 23.78

9) 34.2030 5.1696 1.618000 63.38

10) -189.4107 4.8624

^*11) 53.9597 5.3000 1.739929 49.25

12) -211.8800 D12

13＞1.2000 aperture diaphragm S

14) 172.5088 4.0000 1.846660 23.78

15) -28.2347 1.0000 1.804000 46.58

16) 89.6343 1.9000

17) -39.5906 1.0000 1.804000 46.58

18) 99.5109 D18

19) -134.6632 2.9801 1.497820 82.52?SL2

20) -28.2015 0.1000

21) 217.9857 4.0048 1.618000 63.38

22) -73.2014 0.1000

23) 52.8039 5.0164 1.497820 82.52?SL3

24) -32.8433 1.0000 1.846660 23.78

25) -316.9872

[aspherical surface data]

Surface several 2

κ＝0.0000

C4＝4.40610E-06

C6＝-5.89290E-11

C8＝1.12530E-11

C10＝-1.85420E-14

C12＝0.13297E-16

Surface several 6

κ＝1.0000

C4＝-1.92900E-06

C6＝2.71180E-10

C8＝2.50890E-12

C10＝0.00000E+00

Surface several 11

κ＝1.0000

C4＝1.56610E-06

C6＝-1.53820E-10

C8＝-4.17120E-13

C10＝-6.25410E-16

[variable interval]

Wide-angle is medium dolly-out,s dolly-back

D5 42.31750 14.64730 1.75000

D12 1.35000 13.25580 26.88160

D18 19.82980 14.04550 5.77250

[magnification of each block of lense]

1-POS 2-POS 3-POS

B(1-5) 0.00000 0.00000 0.00000

B(6-10) -3.85705 8.28143 3.35704

B(11-12) 0.14552 -0.12187 -0.47878

B(13-18) -4.46382 -2.94501 -1.77544

B(19-25) -0.22289 -0.33643 -0.58761

4-POS 5-POS 6-POS

β -0.02500 -0.02500 -0.02500

B(1-5) 0.04541 0.02509 0.01492

B(6-10) -3.83872 8.28878 3.36388

B(11-12) 0.14545 -0.12194 -0.47884

B(13-18) -4.46147 -2.94398 -1.77511

B(19-25) -0.22299 -0.33654 -0.58772

7-POS 8-POS 9-POS

β -0.065 -0.112 -0.191

B(1-5) 0.12144 0.11379 0.11446

B(6-10) -3.81947 8.25780 3.39767

B(11-12) 0.14506 -0.12322 -0.48232

B(13-18) -4.44756 -2.92411 -1.75562

B(19-25) -0.22361 -0.33856 -0.59379

Figure 10 A, 10B and 10C are with the various aberrations of the zoom-lens system that is in wide-angle end, middle parfocal attitude and telephoto end in the curve representation example 5 respectively when focusing on infinity.

Obvious from each bar curve, as result, show fabulous optical property according to the zoom-lens system of example 5 to the well-corrected of aberration in every kind of focal length attitude (wide-angle end, middle parfocal attitude and telephoto end).

＜example 6 〉

Figure 11 is that the lens of the zoom-lens system of example 6 according to the present invention constitute sketch.

In zoom-lens system, make by specific glass from the second negative lens SL1 of the first lens combination G1 thing side with from the first positive lens SL2 and the second positive lens SL3 of the 4th lens combination G4 thing side according to example 6.The negative lens SL1 that is made by specific glass is the concave-concave shape, and with the 3rd lens gummed of thing side number.

In zoom-lens system according to example 6, by carrying out from unlimited focusing as far as near object as first lens and a balsaming lens that the mobile integratedly second lens combination G2 thing side of side rises along optical axis direction, wherein said balsaming lens is formed by second lens and the 3rd lens gummed that the second lens combination G2 thing side rises.

Tabulate down every value according to the zoom-lens system of example 6 has been shown in 6.

Table 6

[specification]

Wide-angle is medium dolly-out,s dolly-back

f＝17.55 - 33.28 - 52.70

2A＝83.28 - 47.68 - 31.22°

FNO＝2.89

[lens data]

Surface number r d N v

1) 77.9118 2.5000 1.744429 49.55

^*2) 23.9592 22.1602

3) -70.9994 1.3000 1.497820 82.52?SL1

4) 70.5855 4.0000 1.805180 25.43

5) 237.2767 D5

^*6) 120.3497 5.0000 1.677900 55.34

7) -95.2433 0.1000

8) 75.8?194 1.0000 1.846660 23.78

9) 28.7700 5.3700 1.618000 63.38

10) 219.8396 5.3096

^*11) 49.5255 5.2968 1.744429 49.55

12) -452.9605 D12

13＞1.2000 aperture diaphragm S

14) 271.7867 3.9927 1.846660 23.78

15) -24.9597 1.0000 1.804000 46.58

16) 121.7054 1.9000

17) -34.9526 1.0000 1.804000 46.58

18) 90.3510 D18

19) -334.0058 5.0000 1.569070 71.31?SL2

20) -29.0821 0.1000

21) 105.5941 3.3136 1.569070 71.31?SL3

22) -70.6726 0.1000

23) 53.5984 4.8476 1.487490 70.24

24) -33.5783 1.0000 1.846660 23.78

25) 910.5357

[aspherical surface data]

Surface several 2

κ＝0.0000

C4＝4.14260E-06

C6＝-6.81570E-10

C8＝1.45320E-11

C10＝-2.66210E-14

C12＝0.19986E-16

Surface several 6

κ＝1.0000

C4＝-1.80810E-06

C6＝6.19130E-10

C8＝1.37760E-12

C?10＝0.00000E+00

Surface several 11

κ＝1.0000

C4＝1.89370E-06

C6＝-1.46580E-10

C8＝6.81130E-13

C10＝-1.80850E-15

[variable interval]

Wide-angle is medium dolly-out,s dolly-back

D5 42.29410 13.06960 1.75000

D12 1.35000 15.18390 26.05090

D18 15.70330 9.66630 3.42910

[magnification of each block of lense]

1-POS 2-POS 3-POS

B(1-5) 0.00000 0.00000 0.00000

B(6-10) -3.97099 7.28027 3.47100

B(11-12) 0.14288 -0.14234 -0.43910

B(13-18) -2.58318 -2.00212 -1.36104

B(19-25) -0.35980 -0.48200 -0.76335

4-POS 5-POS 6-POS

β -0.02500 -0.02500 -0.02500

B(1-5) 0.04810 0.02508 0.01580

B(6-10) -3.95130 7.28886 3.47837

B(11-12) 0.14280 -0.14240 -0.43915

B(13-18) -2.58219 -2.00157 -1.36083

B(19-25) -0.35991 -0.48211 -0.76346

7-POS 8-POS 9-POS

β -0.065 -0.119 -0.191

B(1-5) 0.12828 0.12023 0.12138

B(6-10) -3.93153 7.27265 3.51392

B(11-12) 0.14237 -0.14389 -0.44258

B(13-18) -2.57638 -1.98963 -1.34811

B(19-25) -0.36059 -0.48462 -0.77018

Figure 12 A, 12B and 12C are with the various aberrations of the zoom-lens system that is in wide-angle end, middle parfocal attitude and telephoto end in the curve representation example 6 respectively when focusing on infinity.

Obvious from each bar curve, as result, show fabulous optical property according to the zoom-lens system of example 6 to the well-corrected of aberration in every kind of focal length attitude (wide-angle end, middle parfocal attitude and telephoto end).

＜example 7 〉

Figure 13 is that the lens of the zoom-lens system of example 7 according to the present invention constitute sketch.

In zoom-lens system, make by specific glass from the second negative lens SL1 of the first lens combination G1 thing side with from the 3rd positive lens SL2 of the 4th lens combination G4 thing side according to example 7.The negative lens SL1 that is made by specific glass is the concave-concave shape, and with the 3rd lens gummed of thing side number.

In zoom-lens system according to example 7, by carrying out from unlimited focusing as far as near object as first lens and a balsaming lens that the mobile integratedly second lens combination G2 thing side of side rises along optical axis direction, wherein said balsaming lens is formed by second lens and the 3rd lens gummed that the second lens combination G2 thing side rises.

Tabulate down every value according to the zoom-lens system of example 7 has been shown in 7.

Table 7

[specification]

Wide-angle is medium dolly-out,s dolly-back

f＝17.55 - 33.69 - 52.7

2A＝83.28 - 47.06 - 31.18°

FNO＝2.89

[lens data]

Surface number r d N v

1) 75.2416 2.5000 1.744429 49.52

^*2) 24.4203 22.9869

3) -73.2333 1.3000 1.497820 82.52?SL1

4) 67.4284 3.8020 1.805180 25.43

5) 191.7932 D5

^*6) 124.3238 5.0000 1.677900 55.34

7) -96.4073 0.1000

8) 73.8388 1.0000 1.846660 23.78

9) 28.7333 5.2894 1.618000 63.38

10) 214.2545 1.0047

^*11) 50.1522 5.3179 1.744429 49.52

12) -423.1456 D12

13＞1.2000 aperture diaphragm S

14) 386.2371 3.9848 1.846660 23.78

15) -24.4665 1.0000 1.804000 46.58

16) 135.0147 1.9000

17) -33.8942 1.0000 1.804000 46.58

18) 102.3985 D18

19) -295.8454 5.0000 1.618000 63.38

20) -29.5940 0.1000

21) 251.4924 3.0000 1.618000 63.38

22) -69.5799 0.1000

23) 48.1915 5.0395 1.497820 82.52?SL2

24) -33.1614 1.0000 1.846660 23.78

25) 1010.0399

[aspherical surface data]

Surface several 2

κ＝0.0000

C4＝4.05150E-06

C6＝1.80730E-10

C8＝8.75620E-12

C10＝-1.35570E-14

C12＝0.97404E-17

Surface several 6

κ＝1.0000

C4＝-1.73030E-06

C6＝6.55440E-10

C8＝9.44940E-13

C10＝0.00000E+00

Surface several 11

κ＝1.0000

C4＝1.84010E-06

C6＝-2.16860E-10

C8＝1.05490E-12

C10＝-2.04800E-15

[variable interval]

Wide-angle is medium dolly-out,s dolly-back

D5 42.29670 12.65500 1.75000

D12 1.35000 15.88280 26.97720

D18 14.97470 9.12920 2.99450

[magnification of each block of lense]

1-POS 2-POS 3-POS

B(1-5) 0.00000 0.00000 0.00000

B(6-10) -3.98332 7.02463 3.48327

B(11-12) 0.14271 -0.14931 -0.43696

B(13-18) -2.49542 -1.97558 1.39242

B(19-25) -0.36723 -0.48260 -0.73812

4-POS 5-POS 6-POS

β -0.02500 -0.02500 -0.02500

B(1-5) 0.04869 0.02507 0.01599

B(6-10) -3.96324 7.03353 3.49079

B(11-12) 0.14264 -0.14938 -0.43702

B(13-18) -2.49447 -1.97503 -1.39219

B(19-25) -0.36735 -0.48272 -0.73824

7-POS 8-POS 9-POS

β -0.065 -0.120 -0.190

B(1-5) 0.12923 0.12124 0.12231

B(6-10) -3.94326 7.02137 3.52682

B(11-12) 0.14220 -0.15092 -0.44048

B(13-18) -2.48896 -1.96289 -1.37870

B(19-25) -0.36803 -0.48530 -0.74498

Figure 14 A, 14B and 14C are with the various aberrations of the zoom-lens system that is in wide-angle end, middle parfocal attitude and telephoto end in the curve representation example 7 respectively when focusing on infinity.

Obvious from each bar curve, as result, show fabulous optical property according to the zoom-lens system of example 7 to the well-corrected of aberration in every kind of focal length attitude (wide-angle end, middle parfocal attitude and telephoto end).

＜example 8 〉

Figure 15 is that the lens of the zoom-lens system of example 8 according to the present invention constitute sketch.

In zoom-lens system, make by specific glass from the first negative lens SL1 of the first lens combination G1 thing side with from the second positive lens SL2 and the 3rd positive lens SL3 of the 4th lens combination G4 thing side according to example 8.

In zoom-lens system according to example 8, by carrying out from unlimited focusing as far as near object as first lens and a balsaming lens that the mobile integratedly second lens combination G2 thing side of side rises along optical axis direction, wherein said balsaming lens is formed by second lens and the 3rd lens gummed that the second lens combination G2 thing side rises.

Tabulate down every value according to the zoom-lens system of example 7 has been shown in 8.

Table 8

[specification]

Wide-angle is medium dolly-out,s dolly-back

f＝17.55 - 33.80 - 53.4

2A＝83.36 - 46.86 - 30.78°

FNO＝2.89

[lens data]

Surface number r d N v

1) 88.4857 2.0000 1.569070 71.31?SL1

2) 23.1237 12.5909

3) 1676.3197 2.0000 1.796681 45.37

^*4) 37.3077 5.6615

5) 79.7028 3.3257 1.805180 25.43

6) 1620.6953 D6

^*7) 134.8418 5.0000 1.677900 55.34

8) -102.4648 0.1000

9) 125.7885 1.0000 1.805180 25.43

10) 33.4567 7.0000 1.618000 63.38

11) -2913.5812 5.5422

^*12) 53.4429 6.0000 1.589130 61.18

13) -123.9664 D13

14＞1.2000 aperture diaphragm S

15) 152.1655 4.0000 1.846660 23.78

16) -31.2559 1.0000 1.804000 46.58

17) 104.9708 1.8127

18) -39.8203 1.0000 1.804000 46.58

19) 91.7813 D19

20) -530.1722 4.9750 1.618000 63.38

21) -31.9506 1.7123

22) 193.3336 3.0000 1.518601 69.98?SL2

23) -83.1397 0.1000 1.000000

24) 58.3456 5.0292 1.518601 69.98?SL3

25) -31.3537 1.0000 1.846660 23.78

26) -447.5858

[aspherical surface data]

Surface several 4

κ＝0.0000

C4＝-5.36480E-06

C6＝-1.71290E-09

C8＝4.22100E-12

C10＝-2.13050E-14

C12＝0.16581E-16

Surface several 7

κ＝1.0000

C4＝-2.14990E-06

C6＝2.70180E-09

C8＝-1.00150E-12

C10＝0.00000E+00

Surface several 12

κ＝1.0000

C4＝1.65360E-06

C6＝-2.67510E-09

C8＝2.47720E-12

C10＝-3.01900E-15

[variable interval]

Wide-angle is medium dolly-out,s dolly-back

D6 44.20260 13.46390 1.75000

D13 1.35000 19.48370 33.777?10

D19 18.02270 11.52620 2.63440

[magnification of each block of lense]

1-POS 2-POS 3-POS

B(1-6) 0.00000 0.00000 0.00000

B(7-11) -4.30819 6.45890 3.30819

B(12-13) 0.13576 -0.16783 -0.48561

B(14-19) -3.17928 -2.82367 -1.87713

B(20-26) -0.27919 -0.32670 -0.52381

4-POS 5-POS 6-POS

β -0.02500 -0.02500 -0.02500

B(1-6) 0.04882 0.02507 0.01584

B(7-11) -4.28973 6.46779 3.31537

B(12-13) 0.13568 -0.16790 -0.48567

B(14-19) -3.17785 -2.82263 -1.87673

B(20-26) -0.27930 -0.32680 -0.52392

7-POS 8-POS 9-POS

β -0.067 -0.123 -0.196

B(1-6) 0.13309 0.12456 0.12490

B(7-11) -4.27360 6.46338 3.35220

B(12-13) 0.13521 -0.16954 -0.48946

B(14-19) -3.16900 -2.79827 -1.85197

B(20-26) -0.27996 -0.32931 -0.53049

Figure 16 A, 16B and 16C are with the various aberrations of the zoom-lens system that is in wide-angle end, middle parfocal attitude and telephoto end in the curve representation example 8 respectively when focusing on infinity.

Obvious from each bar curve, as result, show fabulous optical property according to the zoom-lens system of example 8 to the well-corrected of aberration in every kind of focal length attitude (wide-angle end, middle parfocal attitude and telephoto end).

＜example 9 〉

Figure 17 is that the lens of the zoom-lens system of example 9 according to the present invention constitute sketch.

In zoom-lens system, make by specific glass from the second negative lens SL1 of the first lens combination G1 thing side with from the first positive lens SL2 and the 3rd positive lens SL3 of the 4th lens combination G4 thing side according to example 9.The negative lens SL1 that is made by specific glass is the concave-concave shape, and with the 3rd lens gummed of thing side number.

In zoom-lens system, carry out from unlimited focusing as far as near object by move the first lens combination G1 thing side second lens that rise and the balsaming lens that the 3rd lens gummed forms integratedly along optical axis direction thing side according to example 9.

Tabulate down every value according to the zoom-lens system of example 9 has been shown in 9.

Table 9

[specification]

Wide-angle is medium dolly-out,s dolly-back

f＝17.55 - 33.28 - 53.4

2A＝83.28 - 47.46 - 30.76°

FNO＝2.89

[lens data]

Surface number r d N v

1) 70.0050 2.5000 1.796681 45.37

^*2) 23.6632 22.6015

3) -53.0877 1.3000 1.569070 71.31?SL1

4) 147.3487 3.1049 1.805180 25.43

5) -247.1033 D5

^*6) 101.4149 4.3103 1.677900 55.34

7) -109.1898 0.1000

8) 140.9023 1.0000 1.846660 23.78

9) 35.0192 6.0000 1.618000 63.38

10) 0.0000 1.0000

11) 46.8922 4.7772 1.804000 46.58

12) 1488.0121 D12

13＞1.4911 aperture diaphragm S

14) 1187.0445 4.0000 1.846660 23.78

15) -24.5906 1.0000 1.804000 46.58

16) 193.7074 1.7281

17) -35.6829 2.0000 1.804000 46.58

18) 101.5499 D18

19) -183.6244 5.0000 1.497820 82.52?SL2

20) -27.0329 0.1?000

21) 164.3441 3.9943 1.618000 63.38

22) -88.5316 0.1000

23) 50.7138 5.3451 1.497820 82.52?SL3

24) -33.3941 1.0000 1.846660 23.78

25) -315.0653

[aspherical surface data]

Surface several 2

κ＝0.0000

C4＝4.38410E-06

C6＝-1.46960E-09

C8＝1.74830E-11

C10＝-3.14280E-14

C12＝0.22738E-16

Surface several 6

κ＝1.0000

C4＝-1.05100E-08

C6＝-4.11860E-10

C8＝1.21380E-12

C10＝0.00000E+00

[variable interval]

Wide-angle is medium dolly-out,s dolly-back

D5 42.50360 13.07170 1.75760

D12 3.37700 17.29450 29.77550

D18 16.52710 10.37550 3.17040

[magnification of each block of lense]

1-POS 2-POS 3-POS

B(1-2) 0.00000 0.00000 0.00000

B(3-5) 0.72388 0.72388 0.72388

B(6-12) -0.57030 -1.06260 -1.59034

B(13-18) -2.92876 -2.13575 -1.46409

B(19-25) -0.31577 -0.44064 -0.68922

4-POS 5-POS 6-POS

β -0.02500 -0.02500 -0.02500

B(1-2) 0.06429 0.03421 0.02139

B(3-5) 0.74365 0.73414 0.73023

B(6-12) -0.57042 -1.06272 -1.59044

B(13-18) -2.92752 -2.13512 -1.46383

B(19-25) -0.31588 -0.44075 -0.68933

7-POS 8-POS 9-POS

β -0.069 -0.123 -0.199

B(1-2) 0.17179 0.16130 0.16270

B(3-5) 0.78256 0.77835 0.77890

B(6-12) -0.57126 -1.06552 -1.59700

B(13-18) -2.91913 -2.12028 -1.44754

B(19-25) -0.31664 -0.44337 -0.69641

Figure 18 A, 18B and 18C are with the various aberrations of the zoom-lens system that is in wide-angle end, middle parfocal attitude and telephoto end in the curve representation example 9 respectively when focusing on infinity.

Obvious from each bar curve, as result, show fabulous optical property according to the zoom-lens system of example 9 to the well-corrected of aberration in every kind of focal length attitude (wide-angle end, middle parfocal attitude and telephoto end).

＜example 10 〉

Figure 19 is that the lens of the zoom-lens system of example 10 according to the present invention constitute sketch.

In zoom-lens system, make by specific glass from the second negative lens SL1 of the first lens combination G1 thing side with from the first positive lens SL2 and the 3rd positive lens SL3 of the 4th lens combination G4 thing side according to example 10.The negative lens SL1 that is made by specific glass is the concave-concave shape, and with the 3rd lens gummed of thing side number.

In zoom-lens system, by moving first lens of the second lens combination G2 thing side along optical axis direction integratedly as side and carrying out from unlimited focusing with the balsaming lens that the 3rd lens gummed forms from second lens of thing side as far as near object by the second lens combination G2 according to example 10.

Tabulate down every value according to the zoom-lens system of example 10 has been shown in 10.

Table 10

[specification]

Wide-angle is medium dolly-out,s dolly-back

f＝17.50 - 31.433 - 53.4

2A＝83.44 - 49.96 - 30.78°

FNO＝2.88

[lens data]

Surface number r d N v

1) 61.1778 2.5000 1.796681 45.37

^*2) 23.8595 22.2571

3) -53.4452 1.3000 1.497820 82.52?SL1

4) 74.5711 2.8345 1.805?180 25.43

5) 251.1650 D5

^*6) 144.7881 3.2432 1.669100 55.39

7) -101.9877 0.1000

8) 115.7173 1.0000 1.846660 23.78

9) 33.8371 5.6799 1.618000 63.38

10) -316.7089 1.0036

^*11) 54.0448 4.9363 1.744429 49.52

12) -201.4533 D12

13＞1.2000 aperture diaphragm S

14) 195.2821 3.6562 1.846660 23.78

15) -28.8371 1.0000 1.804000 46.58

16) 92.5612 1.9195

17) -39.0662 1.0000 1.804000 46.58

18) 115.0637 D18

19) -89.5048 3.2808 1.497820 82.52?SL2

20) -27.7764 0.1000

21) 335.0242 2.6731 1.618000 63.38

22) -64.1525 0.1077

23) 49.9637 6.1661 1.497820 82.52?SL3

24) -32.4974 1.0000 1.846660 23.78

25) -283.4287

[aspherical surface data]

Surface several 2

κ＝0.0000

C4＝4.59450E-06

C6＝6.67330E-10

C8＝7.66470E-12

C10＝-9.79900E-15

C12＝0.59536E-17

Surface several 6

κ＝1.0000

C4＝-1.84030E-06

C6＝-3.89750E-12

C8＝2.85600E-12

C10＝0.00000E+00

Surface several 11

κ＝1.0000

C4＝1.39700E-06

C6＝-3.54520E-11

C8＝-6.71070E-13

C10＝-4.17940E-16

[variable interval]

Wide-angle is medium dolly-out,s dolly-back

D5 42.84360 14.89650 1.75000

D12 1.35000 13.32930 27.30380

D18 19.73850 14.04300 5.54860

[magnification of each block of lense]

1-POS 2-POS 3-POS

B(1-5) 0.00000 0.00000 0.00000

B(6-10) -4.15384 7.21257 3.15345

B(11-12) 0.13506 -0.14079 -0.52025

B(13-18) -4.57979 -2.96156 -1.73145

B(19-25) -0.21668 -0.33252 -0.59806

4-POS 5-POS 6-POS

β -0.02500 -0.02500 -0.02500

B(1-5) 0.04513 0.02496 0.01468

B(6-10) -4.13339 7.22343 3.16041

B(11-12) 0.13506 -0.14079 -0.52025

B(13-18) -4.57979 -2.96157 -1.73145

B(19-25) -0.21668 -0.33252 -0.59806

7-POS 8-POS 9-POS

β -0.065 -0.112 -0.194

B(1-5) 0.11855 0.11125 0.11209

B(6-10) -4.10010 7.26096 3.20652

B(11-12) 0.13506 -0.14079 -0.52025

B(13-18) -4.57979 -2.96156 -1.73145

B(19-25) -0.21668 -0.33252 -0.59806

Figure 20 A, 20B and 20C are with the various aberrations of the zoom-lens system that is in wide-angle end, middle parfocal attitude and telephoto end in the curve representation example 10 respectively when focusing on infinity.

Obvious from each bar curve, as result, show fabulous optical property according to the zoom-lens system of example 10 to the well-corrected of aberration in every kind of focal length attitude (wide-angle end, middle parfocal attitude and telephoto end).

＜example 11 〉

Figure 21 is that the lens of the zoom-lens system of example 11 according to the present invention constitute sketch.

In zoom-lens system, make by specific glass from the second negative lens SL1 of the first lens combination G1 thing side with from the first positive lens SL2 and the 3rd positive lens SL3 of the 4th lens combination G4 thing side according to example 11.The negative lens SL1 that is made by specific glass is the concave-concave shape, and with the 3rd lens gummed of thing side number.

And in zoom-lens system according to the present invention, first lens combination is made up of first sub-lens group with negative refraction focal power and the second sub-lens group with negative refraction focal power from the thing side, and when the location status of lens combination when wide-angle end changes to telephoto end, the distance between the first sub-lens group and the second sub-lens group changes.

In zoom-lens system, by moving first lens of the second lens combination G2 thing side along optical axis direction integratedly as side and carrying out from unlimited focusing with the balsaming lens that the 3rd lens gummed forms from second lens of thing side as far as near object by the second lens combination G2 according to example 11.

Tabulate down every value according to the zoom-lens system of example 11 has been shown in 11.

Table 11

[specification]

Wide-angle is medium dolly-out,s dolly-back

f＝17.55 - 31.40 - 53.40

2A＝83.28 - 50.18 - 30.78°

FNO＝2.89

[lens data]

Surface number r d N v

1) 67.6513 2.5000 1.743200 49.32

^*2) 23.6527 D2

3) -49.9444 1.3000 1.569070 71.31?SL1

4) 113.1596 2.9289 1.805180 25.43

5) -830.9597 D5

^*6) 104.5105 3.7346 1.677900 55.34

7) -114.5393 0.1000

8) 189.2979 1.0000 1.846660 23.78

9) 35.3862 5.0695 1.618000 63.38

10) -176.5596 4.9882

^*11) 56.6910 5.0020 1.785900 44.20

12) -234.1086 D12

13＞1.2000 aperture diaphragm S

14) 172.3609 3.7322 1.846660 23.78

15) -28.5367 1.0000 1.804000 46.58

16) 86.6859 1.9000

17) -39.2371 1.0000 1.804000 46.58

18) 112.6098 D18

19) -133.1178 3.3252 1.497820 82.52?SL2

20) -28.5516 0.1567

21) 211.5776 2.3737 1.618000 63.38

22) -75.1409 0.1000

23) 51.6235 4.8972 1.497820 82.52?SL3

24) -34.3849 1.0000 1.846660 23.78

25) -427.3116

[aspherical surface data]

Surface several 2

κ＝0.0000

C4＝4.28380E-06

C6＝-7.56490E-10

C8＝1.15870E-11

C10＝-1.77280E-14

C12＝0.95593E-17

Surface several 6

κ＝1.0000

C4＝-1.89010E-06

C6＝-8.18450E-10

C8＝3.98740E-12

C10＝0.00000E+00

Surface several 11

κ＝1.0000

C4＝1.23850E-06

C6＝5.67630E-10

C8＝-1.08830E-12

C10＝-7.59160E-16

[variable interval]

Wide-angle is medium dolly-out,s dolly-back

D2 25.08120 23.14950 20.08280

D5 39.35450 13.13730 1.75000

D12 1.35000 12.95820 27.64810

D18 20.54690 14.98470 6.93990

[magnification of each block of lense]

1-POS 2-POS 3-POS

B(1-2) 0.00000 0.00000 0.00000

B(3-5) 0.61981 0.62603 0.63616

B(6-10) -4.25028 7.42456 3.25023

B(11-12) 0.13561 -0.13949 -0.50784

B(13-18) -4.26776 -2.70169 -1.73070

B(19-25) -0.22953 -0.35739 -0.58593

4-POS 5-POS 6-POS

β -0.02500 -0.02500 -0.02500

B(1-2) 0.07047 0.03947 0.02328

B(3-5) 0.63128 0.63253 0.64011

B(6-10) -4.23109 7.43551 3.25743

B(11-12) 0.13561 -0.13949 -0.50784

B(13-18) -4.26776 -2.70169 -1.73070

B(19-25) -0.22953 -0.35739 -0.58593

7-POS 8-POS 9-POS

β -0.06515 -0.11155 -0.19221

B(1-2) 0.17978 0.16922 0.16956

B(3-5) 0.64994 0.65489 0.66605

B(6-10） -4.19750 7.47317 3.30474

B(11-12） 0.13561 -0.13949 -0.50784

B(13-18) -4.26776 -2.70169 -1.73070

B(19-25) -0.22953 -0.35739 -0.58593

Obvious from each bar curve, as result, show fabulous optical property according to the zoom-lens system of example 11 to the well-corrected of aberration in every kind of focal length attitude (wide-angle end, middle parfocal attitude and telephoto end).

Value according to each conditional expression of each example has been shown herein, in table 12.In table 12, SL1 represents to constitute the specific glass of negative lens SL1 among the first lens combination G1 of each example.SL2 and SL3 represent to constitute the specific glass of positive lens among the 4th lens combination G4 of each example.

Table 12

[value of conditional expression]

Conditional expression EX.1 EX.2 EX.3 EX.4 EX.5

(3)SL1 0.077 0.063 0.063 0.063 0.009

(3)SL2 0.063 0.028 0.028 0.028 0.028

(3)SL3 0.028 0.028 0.028 0.028 0.028

(4) 1.86 1.76 1.69 1.75 1.79

(5） 1.24 1.10 1.18 1.16 1.15

(6) 0.94 0.92 0.69 0.70 0.93

(7) 1.27 1.22 1.05 1.06 1.20

EX.6 EX.7 EX.8 EX.9 EX.10 EX.11

(3)SL1 0.028 0.028 0.063 0.063 0.028 0.063

(3)SL2 0.063 0.028 0.009 0.028 0.028 0.028

(3)SL3 0.063 0.009 0.028 0.028 0.028

(4） 1.90 1.92 1.93 1.93 1.80 1.771

(5） 1.20 1.21 1.28 1.28 1.15 1.145

(6) 0.81 0.81 0.88 0.88 0.94 0.94

(7) 1.09 1.08 1.92 1.17 1.20 1.20

As mentioned above, the invention enables and to be implemented in the wide-angle end visual angle and to be not less than 75 °, zoom ratio and to be not less than 3 the zoom-lens system that can obtain fabulous optical property.

The present invention can provide a kind of can obtain the when high-speed super wide zoom lens system of the enough zooms of having of good optical performance.

Other advantage and remodeling are easy to realize very much for a person skilled in the art.Therefore, the invention is not restricted to detail described herein, shown in representative example.Under the prerequisite that does not break away from essence that the present invention limits by claim and equivalent thereof and scope, can do various remodeling to the present invention.

Claims

1. zoom-lens system comprises at least from the thing side:

First lens combination with negative refraction focal power; With

Second lens combination with positive refraction focal power,

When the location status of lens combination when wide-angle end changes to telephoto end, each lens combination all is moved, and makes:

Distance between first lens combination and second lens combination changes;

First lens combination comprises a negative lens element at least;

The glass material that wherein constitutes a negative lens element at least one negative lens element in first lens combination at least satisfies following all three conditional expressions:

67.0＜v

1.40＜N

0＜N+0.0032×v-1.734

2. zoom-lens system as claimed in claim 1 also comprises from the thing side:

Be positioned at three lens combination with negative refraction focal power of second lens combination as side; With

The 4th lens combination with positive refraction focal power,

When the location status of lens combination when wide-angle end changes to telephoto end;

Each lens combination all is moved;

The distance of winning between the lens combination and second lens combination is reduced,

Distance between second lens combination and the 3rd lens combination increases; With

Distance between the 3rd lens combination and the 4th lens combination reduces;

Wherein the 4th lens combination comprises a positive element at least; With

At least the glass material that constitutes a positive element of at least one positive element in the 4th lens combination satisfies following all three conditional expressions:

67.0＜v

1.40＜N

0＜N+0.0032×v-1.734

3. zoom-lens system as claimed in claim 2, wherein satisfy following conditional expression:

1.5＜(-f1)/fw＜2.3

4. zoom-lens system as claimed in claim 3, wherein satisfy following conditional expression:

0.75＜f2/(fw×ft) ^1/2＜1.6

5. zoom-lens system as claimed in claim 4, wherein satisfy following conditional expression:

0.6＜(-f3)/f2＜1.2

0.8＜f4/(fw×ft) ^1/2＜2.0

6. zoom-lens system as claimed in claim 2, wherein satisfy following conditional expression:

0.75＜f2/(fw×ft) ^1/2＜1.6

7. zoom-lens system as claimed in claim 2, wherein satisfy following conditional expression:

0.6＜(-f3)/f2＜1.2

0.8＜f4/(fw×ft) ^1/2＜2.0

Herein, f2 represents the focal length of second lens combination, and f3 represents the focal length of the 3rd lens combination, and f4 represents the focal length of the 4th lens combination, and fw represents the focal length of zoom-lens system in the wide-angle end and the focal length that ft represents zoom-lens system in the telephoto end.

8. zoom-lens system as claimed in claim 2, wherein at least one lens element with negative refraction focal power that concave surface faces image in first lens combination has the aspheric surface of negative refraction focal power, wherein along with the distance of this aspheric surface apart from optical axis increases, the negative refraction focal power dies down.

9. zoom-lens system as claimed in claim 2, the negative lens element that wherein satisfies all three conditional expressions in first lens combination is the concave-concave shape.

10. zoom-lens system as claimed in claim 2, wherein first lens combination comprises negative lens element and other lens element that is made of the glass material that satisfies all three conditional expressions, and this negative lens element and this other lens element gummed.

11. zoom-lens system as claimed in claim 2, wherein the location status of lens combination is formed between each lens element of first lens combination and is all fixed along the distance of optical axis when wide-angle end changes to telephoto end.

12. zoom-lens system as claimed in claim 2, wherein first lens combination is made up of first sub-lens group with negative refraction focal power and the second sub-lens group with negative refraction focal power from the thing side; With

When the location status of lens combination when wide-angle end changes to telephoto end, the distance between the first sub-lens group and the second sub-lens group changes.

13. zoom-lens system as claimed in claim 1 wherein satisfies following conditional expression:

1.5＜(-f1)/fw＜2.3

14. zoom-lens system as claimed in claim 13 wherein satisfies following conditional expression:

0.75＜f2/(fw×ft) ^1/2＜1.6

15. zoom-lens system as claimed in claim 13 wherein satisfies following conditional expression:

0.6＜(-f3)/f2＜1.2

0.8＜f4/(fw×ft) ^1/2＜2.0

Herein, f2 represents the focal length of second lens combination, and f3 represents the focal length of the 3rd lens combination, and f4 represents the focal length of the 4th lens combination and the focal length that ft represents zoom-lens system in the telephoto end.

16. zoom-lens system as claimed in claim 1 wherein satisfies following conditional expression:

0.75＜f2/(fw×ft) ^1/2＜1.6

17. zoom-lens system as claimed in claim 16 wherein satisfies following conditional expression:

0.6＜(-f3)/f2＜1.2

0.8＜f4/(fw×ft) ^1/2＜2.0

18. zoom-lens system as claimed in claim 1, wherein at least one lens element with negative refraction focal power that concave surface faces image in first lens combination has the aspheric surface of negative refraction focal power, wherein along with the distance of this aspheric surface apart from optical axis increases, the negative refraction focal power dies down.

19. zoom-lens system as claimed in claim 1, the negative lens element that wherein satisfies all three conditional expressions in first lens combination is the concave-concave shape.

20. zoom-lens system as claimed in claim 1, wherein first lens combination comprises negative lens element and other lens element that is made of the glass material that satisfies all three conditional expressions, and this negative lens element and this other lens element gummed.

21. zoom-lens system as claimed in claim 1, wherein when the location status of lens combination when wide-angle end changes to telephoto end, form between each lens element of first lens combination and all fix along the distance of optical axis.

22. zoom-lens system as claimed in claim 1, wherein first lens combination is made up of first sub-lens group with negative refraction focal power and the second sub-lens group with negative refraction focal power from the thing side; With