CN101546027B

CN101546027B - Zoom lens, imaging apparatus, and personal data assistant

Info

Publication number: CN101546027B
Application number: CN2008101863417A
Authority: CN
Inventors: 须藤芳文; 厚海广道
Original assignee: Ricoh Co Ltd
Current assignee: Ricoh Co Ltd
Priority date: 2007-12-07
Filing date: 2008-12-08
Publication date: 2011-06-01
Anticipated expiration: 2028-12-08
Also published as: CN101546027A; JP2009236973A; JP5294051B2

Abstract

A zoom lens includes a first optical system having a positive focal length, the first optical system, a second optical system having a negative focal length, a third optical system having a positive focal length, a fourth optical system having a negative focal length, and a fifth optical system having a positive focal length, which are arranged in order from an object side to an image side and anaperture stop provided at an object side of the third optical system. The following condition is satisfied: 0.5<(T23w/Y')/(ft/fw)<1.0, where T23w is an interval between the second optical system and the third optical system at the short focus end, Y' is a maximum image height of the zoom lens, ft is a focal length of the zoom lens at the long focus end, and fw is a focal length of the zoom lens at the short focus end.

Description

Zoom lens, imaging device, personal digital assistant

Technical field

The present invention relates to a kind of zoom lens of within the predetermined focal distance scope, selecting and set focal length as needs.The invention further relates to a kind of being improved to, outside high image quality and the high variable power ratio, have the large aperture, the zoom lens at wide visual angle except that small size.Also can be used to utilize the silver halide photography machine of silver film according to zoom lens of the present invention, be used to use with the imaging device of image transitions as the electronic image pickup device of numerical information but these zoom lens are preferably.Particularly, the present invention relates to a kind of digital camera that is used for, video camera, personal computer, movable computer, cell phone, removable information terminal apparatus, the zoom lens of PDA(Personal Digital Assistant) or the like.

Background technology

In recent years, for high image quality is arranged, small size, the digital camera that wide visual angle and high variable power compare or the like has the demand of increase.With the corresponding production development of these demands be essential.So, it is essential as meniscus camera lens that the zoom lens of the high variable power ratio more than 5 are arranged, and for it being used for the light receiving element that pixel count surpasses 10,000,000 pixels, needs high image quality, small size, wide visual angle and wide-aperture zoom lens.

For example, at JP2005-215165A, JP2005-352348A, among JP2007-171456A and JP2007-3598A or the like, zoom lens are disclosed, wherein begin to have settled in turn first optical system or first lens combination with positive focal length from the thing side, second optical system or second lens combination with negative focal length, the 3rd optical system or the 3rd lens combination with positive focal length, the 5th optical system or the 5th lens combination that have the 4th optical system or the 4th lens combination of negative focal length and have positive focal length, and first optical system comprises for example deflecting optical element of reflecting member or the like.

In addition, when high performance zoom lens is used to high-end (high end) digital camera, must crosses over whole zoom area and obtain approximately at least 5 hundred ten thousand to the corresponding resolution of the image pick-up device of 1,000 ten thousand pixels.

In addition, many users also need the meniscus camera lens of wide visual angle and high variable power ratio.Half angle of view in the zoom lens wide-angle side preferably should be set at more than 38 degree.When being converted to the focal length of 35mm silver halide photography machine (so-called Leica version), 38 degree half angle of view equal 28mm.On the other hand, the variable power ratio of needs more than 5.

For above requirement, JPH8-248318A and JP2005-215165A disclose a kind of traditional zoom lens, wherein by inserting thinner shape on the optical axis direction of prism acquisition at camera within the optical system.

Promptly, JPH8-248318A discloses a kind of zoom lens, it begins to settle in turn the variable power system that is made of first optical system with positive refractive power (refractive power) and second optical system with negative refractive power from the thing side, the aperture, fixing the 3rd optical system with positive refractive power, what be used for when the distance to main body changes maybe when situations such as change magnification adjusting focal position has positive refractive power and the 4th optical system movably.

First optical system of zoom lens begins to comprise in turn first concavees lens from the thing side, cross prisms, first convex lens, the cemented lens of second concavees lens and second convex lens.

In addition, JP2005-215165A discloses a kind of zoom lens, it begins to comprise in turn to have positive refractive power and fixing first lens combination when the zoom from the thing side, second lens combination with negative refractive power, the 3rd lens combination with positive refractive power, the 4th lens combination with negative refractive power has the 5th lens combination of positive refractive power, and wherein zoom is undertaken by moving the second lens combination and the 4th lens combination at least.First lens combination of zoom lens begins to comprise in turn the first single lens with negative refractive power from the thing side, with the reflecting member of crooked 90 degree of light path and second lens that at least one has positive refractive power.

Yet disclosed zoom lens are suitable for video camera most in JPH8-248318A and JP2005-215165A.In specific embodiment, the variable power ratio is to be more than 7 more than 8 and in JP2005-215165A in JP2005-215165A.But and so big variable power at about 33 degree of being of wide-angle side half angle of view, approximately is 34 degree in JP2005-215165A in JPH8-248318A, so that does not satisfy the requirement that surpasses 38 degree that puts on digital camera than paired ratio.

In JP2005-215165A, the high power that the numerical example 2 of second embodiment discloses zoom ratio 7 is amplified the example of the zoom lens of zoom.Yet in this case, aperture and the 3rd optical system (the 3rd lens combination) have integrated structure so that when the visual angle is widened, are placed in after optical system from the aperture to the thing side and become too big and revise aberration and become difficult.So, in this example, the above wide visual angle of 38 degree of being unrealized.

In JP2005-352348A, the numerical example 3 of the 3rd embodiment discloses the example of the zoom lens of a kind of high variable power and wide-angle, wherein zoom ratio approximately be 35 and wide visual angle surpass 38 degree.Yet in this case, aperture and the 3rd optical system (the 3rd lens combination) have integrated structure so that size is too big.In addition, in this case, become and realize high-performance to heavens greatly and no longer.

The zoom lens of a kind of high variable power and wide-angle are disclosed in the 3rd embodiment in JP2007-171456A, wherein zoom ratio approximately be 7 and wide visual angle surpass 38 degree.Yet same in this case, aperture and the 3rd optical system (the 3rd lens combination) are integrally settled, so that light path is had to by being bent at the short side direction as the image pick-up device of image pickup surface as the reflecting member of deflecting optical element.So it is difficult that the layout of camera becomes.Under such structure, in long limit or longitudinal bending light path, need be exaggerated so that first optical system (first lens combination) becomes big and revises the aberration difficulty that becomes as the prism of reflecting member.

In each embodiment of JP2007-3598A, disclose when holding from short Jiao to the burnt end change of length magnification, the interval between aperture and the 3rd optical system (the 3rd lens combination) is reduced.Yet, in this case, do not realize wide visual angle and 5 above high variable power ratios that 38 degree are above.In addition, under such structure,, need satisfy condition illustrated in the claim 1 of JP2007-3598A in order to realize wide visual angle and high variable power ratio.

Summary of the invention

Target of the present invention is zoom lens, imaging device, personal digital assistant, the aberration that for example amplifies wherein, the coma of color, or the like various aberrations can suitably be corrected, and while undersized body aspect the thickness of optical axis direction, high-performance, for example, the above wide half angle of view of 38 degree, for example, high variable power ratio more than 5, for example, 5 * 10 ⁶To 10 ⁷The high resolving power of pixel.

For realizing above target, zoom lens have first optical system of positive focal length according to an embodiment of the invention, this first optical system comprises deflecting optical element, second optical system with negative focal length, the 3rd optical system with positive focal length has the 4th optical system of negative focal length, has the 5th optical system of positive focal length, described first to the 5th optical system is arranged from the object side to image side in turn, and the aperture diaphragm that is provided in the thing side of described the 3rd optical system.When holding long burnt end to change the magnification of zoom lens from short Jiao, interval between first optical system and second optical system increases, interval between second optical system and the aperture diaphragm reduces, interval between aperture diaphragm and the 3rd optical system reduces, interval between the 3rd optical system and the 4th optical system increases, and the interval between the 4th optical system and the 5th optical system increases.Meet the following conditions: 0.5＜(T23w/Y ')/(ft/fw)＜1.0

Wherein T23w is the interval between short burnt end second optical system and the 3rd optical system, and Y ' is the maximum picture height of zoom lens, and ft is the focal lengths of zoom lens at long burnt end, and fw is the focal lengths of zoom lens at short burnt end.And the 4th optical system is when keeping static from short burnt end when long burnt end changes the magnification of zoom lens, at the maximum diameter of hole Dt of long burnt stomidium footpath diaphragm greater than maximum diameter of hole Dw at short burnt stomidium footpath diaphragm.

Description of drawings

Fig. 1 is that schematically diagram is according to the sectional view of the optical system in the zoom lens of the example 1 of first embodiment of the invention along the structure of the optical axis of these zoom lens.

Fig. 2 is the spherical aberration that diagram is held short Jiao according to the zoom lens of example shown in Figure 11, astigmatism, the figure of the aberration curve of distortion and coma.

Fig. 3 is diagram according to the zoom lens of example shown in Figure 11 spherical aberration in the middle focal length position, astigmatism, the figure of the aberration curve of distortion and coma.

Fig. 4 is the spherical aberration that diagram is held long Jiao according to the zoom lens of example shown in Figure 11, astigmatism, the figure of the aberration curve of distortion and coma.

Fig. 5 is that schematically diagram is according to the sectional view of the optical system in the zoom lens of the example 2 of first embodiment of the invention along the structure of the optical axis of these zoom lens.

Fig. 6 is the spherical aberration that diagram is held short Jiao according to the zoom lens of example shown in Figure 52, astigmatism, the figure of the aberration curve of distortion and coma.

Fig. 7 is diagram according to the zoom lens of example shown in Figure 52 spherical aberration in the middle focal length position, astigmatism, the figure of the aberration curve of distortion and coma.

Fig. 8 is the spherical aberration that diagram is held long Jiao according to the zoom lens of example shown in Figure 52, astigmatism, the figure of the aberration curve of distortion and coma.

Fig. 9 is that schematically diagram is according to the sectional view of the optical system in the zoom lens of the example 3 of first embodiment of the invention along the structure of the optical axis of these zoom lens.

Figure 10 is the spherical aberration that diagram is held short Jiao according to the zoom lens of example shown in Figure 93, astigmatism, the figure of the aberration curve of distortion and coma.

Figure 11 is diagram according to the zoom lens of example shown in Figure 93 spherical aberration in the middle focal length position, astigmatism, the figure of the aberration curve of distortion and coma.

Figure 12 is the spherical aberration that diagram is held long Jiao according to the zoom lens of example shown in Figure 93, astigmatism, the figure of the aberration curve of distortion and coma.

Figure 13 is that schematically diagram is according to the sectional view of the optical system in the zoom lens of the example 4 of first embodiment of the invention along the structure of the optical axis of these zoom lens.

Figure 14 is the spherical aberration that diagram is held short Jiao according to the zoom lens of example shown in Figure 13 4, astigmatism, the figure of the aberration curve of distortion and coma.

Figure 15 is diagram according to the zoom lens of example shown in Figure 13 4 spherical aberration in the middle focal length position, astigmatism, the figure of the aberration curve of distortion and coma.

Figure 16 is the spherical aberration that diagram is held long Jiao according to the zoom lens of example shown in Figure 13 4, astigmatism, the figure of the aberration curve of distortion and coma.

Figure 17 is that schematically diagram is according to the sectional view of the optical system in the zoom lens of the example 5 of first embodiment of the invention along the structure of the optical axis of these zoom lens.

Figure 18 is the spherical aberration that diagram is held short Jiao according to the zoom lens of example shown in Figure 17 5, astigmatism, the figure of the aberration curve of distortion and coma.

Figure 19 is diagram according to the zoom lens of example shown in Figure 17 5 spherical aberration in the middle focal length position, astigmatism, the figure of the aberration curve of distortion and coma.

Figure 20 is the spherical aberration that diagram is held long Jiao according to the zoom lens of example shown in Figure 17 5, astigmatism, the figure of the aberration curve of distortion and coma.

Figure 21 is the sectional view of the structure of the optical system in the zoom lens of schematically diagram embodiment according to the present invention 6.

Figure 22 is the spherical aberration that diagram is held short Jiao according to the zoom lens of example 6, astigmatism, the figure of the aberration curve of distortion and coma.

Figure 23 is diagram according to the zoom lens of example 6 spherical aberration in the middle focal length position, astigmatism, the figure of the aberration curve of distortion and coma.

Figure 24 is the spherical aberration that diagram is held long Jiao according to the zoom lens of example 6, astigmatism, the figure of the aberration curve of distortion and coma.

Figure 25 is the sectional view of the structure of the optical system in the zoom lens of schematically diagram embodiment according to the present invention 7.

Figure 26 is the spherical aberration that diagram is held short Jiao according to the zoom lens of example 7, astigmatism, the figure of the aberration curve of distortion and coma.

Figure 27 is diagram according to the zoom lens of example 7 spherical aberration in the middle focal length position, astigmatism, the figure of the aberration curve of distortion and coma.

Figure 28 is the spherical aberration that diagram is held long Jiao according to the zoom lens of example 7, astigmatism, the figure of the aberration curve of distortion and coma.

Figure 29 is the sectional view of the structure of the optical system in the zoom lens of schematically diagram embodiment according to the present invention 8.

Figure 30 is the spherical aberration that diagram is held short Jiao according to the zoom lens of example 8, astigmatism, the figure of the aberration curve of distortion and coma.

Figure 31 is diagram according to the zoom lens of example 8 spherical aberration in the middle focal length position, astigmatism, the figure of the aberration curve of distortion and coma.

Figure 32 is the spherical aberration that diagram is held long Jiao according to the zoom lens of example 8, astigmatism, the figure of the aberration curve of distortion and coma.

Figure 33 is the sectional view of the structure of the optical system in the zoom lens of schematically diagram embodiment according to the present invention 9.

Figure 34 is the spherical aberration that diagram is held short Jiao according to the zoom lens of example 9, astigmatism, the figure of the aberration curve of distortion and coma.

Figure 35 is diagram according to the zoom lens of example 9 spherical aberration in the middle focal length position, astigmatism, the figure of the aberration curve of distortion and coma.

Figure 36 is the spherical aberration that diagram is held long Jiao according to the zoom lens of example 9, astigmatism, the figure of the aberration curve of distortion and coma.

Figure 37 is the sectional view of the structure of the optical system in the zoom lens of schematically diagram embodiment according to the present invention 10.

Figure 38 is the spherical aberration that diagram is held short Jiao according to the zoom lens of example 10, astigmatism, the figure of the aberration curve of distortion and coma.

Figure 39 is diagram according to the zoom lens of example 10 spherical aberration in the middle focal length position, astigmatism, the figure of the aberration curve of distortion and coma.

Figure 40 is the spherical aberration that diagram is held long Jiao according to the zoom lens of example 10, astigmatism, the figure of the aberration curve of distortion and coma.

Figure 41 A is that the camera of a fourth embodiment in accordance with the invention is from the front side, at the stereographic map of collapse state.

Figure 41 B is according to the part of the camera of the fourth embodiment of the invention front perspective view at extended configuration.

Figure 41 C is the rear perspective view according to the camera of fourth embodiment of the invention.

Figure 42 is the block scheme of demonstration according to the system architecture of the camera of fourth embodiment of the invention.

Embodiment

Explain zoom lens of the present invention below with reference to accompanying drawing, imaging device, and the optimal case of personal digital assistant.

At first, with the zoom lens of explaining according to first embodiment of the invention.

Current, for digital camera, high image quality, small size, and the wide-angle aspect need increase, and, in order to satisfy the demand, as the imaging optical system in such digital camera, the zoom lens of negative leading type (negative-leadtype) are currently to be concerned about most.In addition, viewpoint from portability and its design, need to realize the imaging optical system of camera low thickness generally, and used the zoom lens that have on the light path that is placed in zoom lens with the reflecting surface of reflection and deflection light.In these zoom lens, light path is bent at this reflecting surface.

As an example, a kind of zoom lens have been proposed, wherein begin to arrange in turn and have first optical system of positive focal length from the thing side, second optical system with negative focal length, the 3rd optical system with positive focal length has the 4th optical system of positive focal length, has the 5th optical system of negative focal length, and the 6th optical system with positive focal length, and first optical system has deflecting optical element.In the zoom lens of such type, the influence trend that produces owing to the eccentric sensitivity of the lens combination in the 3rd optical system and the 4th optical system is bigger, and this causes and makes difficulty.

[first embodiment]

Zoom lens according to first embodiment of the invention comprise first optical system or the first lens combination G1 with positive focal length, second optical system or the second lens combination G2 with negative focal length, the 3rd optical system or the 3rd lens combination G3 with positive focal length, the 4th optical system or the 4th lens combination G4 with negative focal length, and the 5th optical system or the 5th lens combination G5 with positive focal length, they begin to arrange in turn from the thing side.These zoom lens also have the aperture diaphragm of the thing side that is arranged on the 3rd optical system, and first optical system can comprise deflecting optical element.

When holding long burnt end to change the magnification of zoom lens from short Jiao, interval between first optical system and second optical system increases, interval between second optical system and the aperture diaphragm reduces, interval between aperture diaphragm and the 3rd optical system reduces, interval between the 3rd optical system and the 4th optical system increases, and the interval variation between the 4th optical system and the 5th optical system.

If aperture diaphragm is arranged on the 3rd optical system thing side in the 3rd optical system independently, and when zoom lens are set to the burnt end of weak point, aperture diaphragm is moved to from the 3rd optical system more near second optical system, then can avoid owing to wide-angle change increase from axle light, consequently can realize the small size of zoom lens.Thereby, can realize the small size of zoom lens and the aberration of modified off-axis light easily.

In the zoom lens of such type, second optical system and the 3rd optical system are as the variable magnification optical system or the variable magnification lens group of the magnification that mainly is used to change zoom lens.In order to realize high variable power ratio, between second optical system and the 3rd optical system is important at interval.

In order to realize the variable power ratio more than 5, it realizes the above wide half angle of view of 38 degree, preferably meeting the following conditions:

0.5<(T23w/Y’)(ft/fw)<1.0 (1)

Wherein T23w is the interval between short burnt end second optical system and the 3rd optical system, and Y ' is the maximum image height degree of zoom lens, and ft is the focal lengths of zoom lens at long burnt end, and fw is the focal lengths of zoom lens at short burnt end.

If the lower limit of value less-than condition (1), then the interval between second optical system and the 3rd optical system is too little, so the focal power of second optical system and the 3rd optical system is required too big, it is difficult consequently running through whole zooming range modified off-axis aberration.If should be worth the upper limit of greater than condition (1), then the interval between second optical system and the 3rd optical system is too big, so passes through the higher from axle light of second optical system and the 3rd optical system at short burnt end, so that the correction of off-axis aberration becomes difficult.

So, for the further small size that realizes zoom lens and the performance of Geng Gao, preferably meeting the following conditions:

0.2<Ts3w/T2sw<1.5 (2)

Wherein Ts3w is the interval between short burnt stomidium footpath diaphragm and the 3rd optical system, and T2sw is the interval between short burnt end second optical system and aperture diaphragm.

If the lower limit of value less-than condition (2), then the aperture from second optical system too far away so that increasing through the lens combination of the thing side that is arranged in short burnt stomidium footpath diaphragm from axle light.So the off-axis aberration of revising for first optical system or second optical system becomes difficult.On the other hand, if should be worth the upper limit of greater than condition (2), then aperture diaphragm is from the 3rd optical system consequently increasing from axle light of the 3rd optical system too far away.So, revise the 3rd optical system off-axis aberration and become difficult.

Maximum diameter of hole Dt at long burnt stomidium footpath diaphragm can be greater than the maximum diameter of hole Dw at short burnt stomidium footpath diaphragm.In structure according to this embodiment of the invention, if hold the aperture of long burnt stomidium footpath diaphragm identical from short Jiao, then in the F value (F number) of the zoom lens of long burnt end greater than short burnt the end.Thereby, be set to greater than consequently obtaining little full aperture F value in short burnt maximum diameter of hole of holding in the maximum diameter of hole of length Jiao end.If the maximum diameter of hole keeps constant and be set to lessly when short Jiao holds long burnt end to change magnification in that long burnt end F is worthwhile, then become too little in short burnt end F value, therefore to revise in short burnt end spherical aberration, it is difficult that coma or the like becomes.

In this embodiment, preferably meeting the following conditions:

2.0>Dt/Dw>1.1 (3)

Wherein Dt is the maximum diameter of hole at short burnt stomidium footpath diaphragm at the maximum diameter of hole and the Dw of long burnt stomidium footpath diaphragm.

If the lower limit of value less-than condition (3) then when in long burnt end F value hour, becomes too little in the short burnt F value of holding.Thereby, revise spherical aberration at short burnt end, it is difficult that coma or the like becomes.On the other hand, if the upper limit of value greater than condition (3) then becomes too little in long burnt end F value, so revises the spherical aberration at long burnt end, it is difficult that coma or the like becomes.

In this embodiment, preferably meeting the following conditions:

-3.0<f2/Y’<-1.2 (4)

2.0<f3/Y’<4.0 (5)

Wherein f2 is that the focal length and the f3 of second optical system are the focal length of the 3rd optical system.

If the lower limit of value f2/Y ' less-than condition (4), then the too big aberration of consequently revising in second optical system of the focal power of second optical system becomes difficult.On the other hand, if the upper limit of value f2/Y ' greater than condition (4), then the focal power of second optical system is too little.When using second optical system to change magnification, the amount of movement of second optical system big so that through first optical system of short burnt end or second optical system become too big from axle light, so the size of zoom lens should increase.Thereby it is difficult that the modified off-axis aberration becomes.

If value f3/Y ' is the lower limit of less-than condition (5), then the too big aberration of consequently revising in the 3rd optical system of the focal power of the 3rd optical system becomes difficult.On the other hand, if the upper limit of the value f3/Y ' greater than condition (5) of condition (5), then the focal power of the 3rd optical system is too little, and therefore the amount of movement of the 3rd optical system can not use the 3rd optical system to change the magnification of zoom lens too greatly.Thereby, become too big so that the modified off-axis aberration difficulty that becomes from axle light what short burnt end entered the 3rd optical system.

In zoom lens according to this embodiment of the invention, when holding long burnt end to change the magnification of zoom lens from short Jiao, the 4th optical system is preferably still to be kept.If the 4th optical system is not moved and remains on the fixed position in the process of the magnification that changes zoom lens, then can be reduced at the lens drum structure that wherein is provided with zoom lens, and guarantee the eccentric precision in the middle of optical system.Though the whole optical systems in the mobile zoom lens are favourable to revising aberration effectively, the structure of lens drum is complicated so that the easy manufacturing mistake that occurs.

Because second optical system and the 3rd optical system mainly are the variable magnification optical systems that changes the zoom lens magnification, so in order to realize high-performance and high variable power ratio, preferably meeting the following conditions:

3.5>b2t/b2w>2.0 (6)

3.0>b3t/b3w>1.5 (7)

Wherein b2t is the lateral magnification in second optical system of long burnt end, b2w is the lateral magnification in second optical system of short burnt end, b3t is the lateral magnification in the 3rd optical system of long burnt end, and b3w is the lateral magnification in the 3rd optical system of short burnt end.

If the upper limit of value b2t/b2w greater than condition (6), then the variable power that produces owing to second optical system is bigger than too, and therefore the amount of movement of second optical system is too big.Thereby, need the large scale of zoom lens and by increasing so that the modified off-axis aberration difficulty that becomes in first optical system of short burnt end or second optical system from axle light.If the lower limit of value b2t/b2w less-than condition (6), then the variable power that produces owing to second optical system is smaller, therefore need since the big variable power that other optical system produces than so that run through whole zooming range correction aberration and become difficult.

If the upper limit of value b3t/b3w greater than condition (7), then the variable power that produces owing to the 3rd optical system is bigger than too, and therefore the amount of movement of the 3rd optical system is too big.Thereby, need the large scale of zoom lens and by increasing so that the modified off-axis aberration difficulty that becomes in the 3rd optical system of short burnt end from axle light.If the lower limit of value b3t/b3w less-than condition (7), then the variable power that produces owing to the 3rd optical system is smaller, therefore need since the big variable power that second optical system produces than so that the whole zooming range correction aberration that run through zoom lens become difficult.

In order to realize high-performance and high variable power ratio, preferably meeting the following conditions:

1.0>(b3t/b3w)/(b2t/b2w)>0.5 (8)

Wherein b2t is the lateral magnification in second optical system of long burnt end, b2w is the lateral magnification in second optical system of short burnt end, b3t is the lateral magnification in the 3rd optical system of long burnt end, and 3w is the lateral magnification in the 3rd optical system of short burnt end.

If the upper limit of value greater than condition (8), then owing to the variable power ratio that the 3rd optical system produces becomes too big, therefore consequently can the modified off-axis aberration by increasing of the 3rd optical system from axle light.If the lower limit of value less-than condition (8), then owing to the variable power ratio that second optical system produces becomes too big, therefore increasing so that the modified off-axis aberration becomes difficult by second optical system from axle light.

Though the basic structure according to the zoom lens of first embodiment of the invention more than has been described, will be referring to figs. 1 to 16 based on the various examples of concrete Numerical examples detailed description according to the zoom lens of this embodiment.

(example 1)

With the concrete example that describes in detail according to the zoom lens of first embodiment of the invention.Example 1,2,3 and 4 based on the concrete structure of concrete Numerical examples demonstration according to the zoom lens of this embodiment.In example 1 to 4, display structure and concrete Numerical examples.

In example 1 to 4, zoom lens further comprise optical element, and it is placed in the picture side of the 5th lens combination and forms with the parallel-plate form.For instance, this optical element is, such as the optics low pass filter, the optical filter of cutoff filter or the like perhaps such as the cover glass (seal glass) of the light receiving element of ccd sensor or the like, and is called optical filter hereinafter.

In addition, in example 1 to 4, aspheric surface be arranged on the first lens combination G1 the most close thing side (most objectside) lens the picture side surface, at the picture side surface of the lens of the most close thing side of the second lens combination G2, and in the surface of the most close thing side of the 3rd lens combination G3 and the most close picture side.Though each aspheric surface in the example 1 to 4 is so-called aspheric surface mold lens (mold lens), each aspheric surface can be placed on the spherical lens by resin molding therein and form to form aspheric so-called aspheric surface hybrid lens.

In example 1 to 4, aberration is revised fully, and can be with this zoom lens applications in having 10 ⁷The light receiving element of pixel.Because the structure of zoom lens can realize the above wide half angle of view of 38 degree according to an embodiment of the invention, the zoom lens of fully little size, and fabulous imaging performance,

The reference number of Shi Yonging is expressed as follows hereinafter:

F: total focal length of lens combination

F (F No.): F number (F value)

ω: half angle of view (degree)

R: radius-of-curvature

DA, DB, DC, DD, DE, DF:(is variable) at interval

Nd: refractive index

Vd: Abbe number (Abbe number)

K: the aspheric constant of the cone

A4: quadravalence asphericity coefficient

A6: six rank asphericity coefficients

A8: eight rank asphericity coefficients

About this point, the aspheric surface that is used for following example is limited by following equation:

x = \frac{{CH}^{2}}{1 + \sqrt{1 - (K + 1) C^{2} H^{2})}} + A_{4} \cdot H^{4} + A_{6} \cdot H^{6} + A_{8} \cdot H^{8} - - - (9)

Wherein C is the inverse (paraxial curvature) of paraxial radius-of-curvature, and H is the height that the optical axis from zoom lens begins.

Fig. 1 shows the structure of optical system of the zoom lens of embodiment according to the present invention 1.Holding from weak point is burnt, promptly wide-angle side (WIDE) is held to long Jiao by the focal position (MEAN) of centre, and the position of each lens combination as shown in Figure 1 in the process that the end (TELE) of promptly dolly-out,ing dolly-back changes.The motion track of each lens combination also schematically is presented among Fig. 1 in the zoom process.

Zoom lens shown in Figure 1 comprise the first lens L1, the second lens L2, the 3rd lens L3, the 4th lens L4, the 5th lens L5, the 6th lens L6, the 7th lens L7, the 8th lens L8, the 9th lens L9, the tenth lens L10, the 11 lens L11, the 12 lens L12, prism PR, the optical filter OF of aperture diaphragm FA and above explanation.In this case, the first lens L1, prism PR, the second lens L2, and the 3rd lens L3 constitute the first optical system G1, the 4th to the 6th lens L4 constitutes the second optical system G2 to L6, the 7th to the tenth lens L7 constitutes the 3rd optical system G3 to L10, the 11 lens L11 constitutes the 4th optical system G4 individually, and the 12 lens L12 constitutes the 5th optical system G5 individually.Each optical system is supported by suitable public underframe or the like, and each optical system is integrally operated in the zoom process to change the first optical system G1, the second optical system G2, aperture diaphragm FA, the 3rd optical system G3, the 4th optical system G4, relative distance between the 5th optical system G5 and optical filter OF or interval.In Fig. 1, show the surperficial number of optical surface in the zoom lens.

In addition, each reference number among Fig. 1 is used for each example independently to avoid owing to the reference number that increases causes burdensome in the accompanying drawings explanation.Though the identical reference number among Fig. 1 is at Fig. 5,9, with 13 in will be used for the different structure of zoom lens, structure is not restricted to it.

In Fig. 1, constitute each optical element of the optical system of zoom lens, in series settled, for example, the first lens L1, prism PR, the second lens L2, the 3rd lens L3, the 4th lens L4, the 5th lens L5, the 6th lens L6, aperture diaphragm FA, the 7th lens L7, the 8th lens L8, the 9th lens L9, the tenth lens L10, the 11 lens L11, the 12 lens L12, and optical filter OF begun to arrange from the thing side in sequential seriesly, so that picture is imaged on the back side of optical filter OF.

The first lens L1 is diverging meniscus lens (neagative meniscus lens), and it has in the aspheric surface of picture side and at the convex surface of thing side.Prism PR is used as the deflecting optical element of deflection optical path.Prism PR reflected light path and with its deflection, for example, 90 degree.The second lens L2 is a positive lens, and it all has convex surface in the thing side with as the side both sides.The 3rd lens L3 is a positive lens, and it all has convex surface in both sides.The first lens L1, prism PR, the second lens L2 and the 3rd lens L3 formation have the first optical system G1 of positive focal length, and are operated in groups in the zoom process.In this case, when zoom, it is static that the first optical system G1 keeps, that is, do not move in the fixed position.

The 4th lens L4 has concave surface and wherein is formed aspheric negative lens at the concave surface as side in both sides.The 5th lens L5 is that the negative lens and the 6th lens L6 that have concave surface in both sides are the positive lenss that has convex surface in both sides.The 5th lens L5 and the 6th lens L6 closely are attached to each other, and by integrally bonding (cement) to form the cemented lens (cemented lens) that forms by these two lens.The the 4th to the 6th lens L4 constitutes the second optical system G2 with negative focal length and operates in groups when the zoom to L6.

Aperture diaphragm FA operates individually when zoom.In this case, aperture diaphragm FA does not move in the fixed position when zoom.

The 7th lens L7 has convex surface and wherein is formed aspheric positive lens at the convex surface of thing side in both sides.The 8th lens L8 is that the positive lens and the 9th lens L9 that have convex surface in both sides are the negative lenses that has concave surface in both sides.The 8th lens L8 and the 9th lens L9 closely are attached to each other, and by integrally bonding to form the cemented lens that forms by these two lens.The tenth lens L10 has convex surface and wherein is formed aspheric positive lens at the convex surface as side in both sides.Above-mentioned the 7th to the tenth lens L7 constitutes the 3rd optical system G3 with positive focal length and operates in groups when the zoom to L10.

The 11 lens L11 has concave surface and wherein is formed aspheric negative lens at the concave surface as side in both sides.The 11 lens L11 constitutes the 4th optical system G4 with negative focal length individually and operates in groups when zoom.In this case, the 4th optical system G4 does not move in the fixed position when zoom.

The 12 lens L12 has convex surface and wherein is formed aspheric positive lens at the convex surface of thing side in both sides.The 12 lens L12 constitutes the 5th optical system G5 with positive focal length individually and operates in groups when zoom.

In the process of the magnification that between short burnt end (wide-angle side) and long burnt end (end of dolly-out,ing dolly-back (telephoto end)), changes zoom lens, the interval D A between the optical element in the zoom lens, DB, DC, DD, DE and DF are variable.Interval D A is the surface of the first optical system G1 in the most close picture side of the first optical system G1, promptly the 3rd lens L3 is on the surface (9) of picture side, with the second optical system G2 on the surface of the most close thing side, i.e. the interval of the 4th lens L4 between the surface (10) of thing side.Interval D B be the second optical system G2 on the surface of the most close picture side of the second optical system G2, i.e. the interval of the 6th lens L6 between the surface (15) of picture surface (14) of side and aperture diaphragm FA.Interval D C be surface (15) and the 3rd optical system G3 of aperture diaphragm FA on the surface of the most close thing side of the 3rd optical system G3, i.e. the interval of the 7th lens L7 between the surface (16) of thing side.Interval D D is the surface of the 3rd optical system G3 in the most close picture side of the 3rd optical system G3, promptly the tenth lens L10 is on the surface (22) of picture side, with the 4th optical system G4 on the surface of the most close thing side, i.e. the interval of the 11 lens L11 between the surface (23) of thing side.Interval D E is the surface of the 4th optical system G4 in the most close picture side of the 4th optical system G4, promptly the 11 lens L11 is on the surface (24) of picture side, with the 5th optical system G5 on the surface of the most close thing side, i.e. the interval of the 12 lens L12 between the surface (25) of thing side.Interval D F be the 5th optical system G5 on the surface of the most close picture side of the 5th optical system G5, promptly the 12 lens L12 is at the surface (26) of picture side, and the interval of optical filter OF between the surface (27) of the most close thing side.

When holding the magnification that changes zoom lens to dolly-out,ing dolly-back from wide-angle side, the second optical system G2, the 3rd optical system G3, and the 5th optical system G5 is moved so that the interval D A between the first optical system G1 and the second optical system G2 little by little increases, interval D B between the second optical system G2 and the aperture diaphragm FA little by little reduces, interval D C between aperture diaphragm FA and the 3rd optical system G3 little by little reduces, interval D D between the 3rd optical system G3 and the 4th optical system G4 little by little increases, interval D E between the 4th optical system G4 and the 5th optical system G5 little by little increases, and the interval D F between the 5th optical system G5 and the optical filter OF little by little reduces.

When from wide-angle side moving when the end of dolly-out,ing dolly-back changes the magnification of zoom lens, the second optical system G2 is roughly monotonously to the picture side shifting, the 3rd optical system G3 is roughly monotonously to the thing side shifting, and the 5th optical system G5 quilt is roughly monotonously to the picture side shifting.

In example 1, the focal distance f of zoom lens and F value F change in 5.40 scopes at f=5.20 to 34.93 and F=3.69 respectively.The optical property of each optical element is shown in following table.

[table 1]

In table 1, asterisk represents that this surface is an aspheric surface.That is, second surface, the 11 surface, the 16 surface, the 22 surface, the 24 surface, and each of the 25 surface all be aspheric surface, and as follows for the parameter in each aspheric equation (9).

Aspheric surface: second surface

K＝-2.66318E-05(＝-2.66318?x?10 ^-5)

A ₄＝-3.73542E-07

A ₆＝3.46456E-09

A ₈＝-3.54130E-11

Aspheric surface: the 11 surface

K＝-1.16008E-05

A ₄＝1.75709E-06

A ₆＝-5.13170E-08

A ₈＝2.30633E-09

Aspheric surface: the 16 surface

K＝-7.64600E-05

A ₄＝1.18832E-06

A ₆＝-7.00964E-08

A ₈＝1.35244E-09

Aspheric surface: the 22 surface

K＝-5.97807E-05

A ₄＝5.86433E-06

A ₆＝-8.40400E-07

A ₈＝2.09610E-08

Aspheric surface: the 24 surface

K＝1.51024E-04

A ₄＝9.33987E-06

A ₆＝-3.92025E-07

A ₈＝6.18211E-09

Aspheric surface: the 25 surface

K＝9.38549E-05

A ₄＝1.41070E-05

A ₆＝-6.64229E-07

A ₈＝1.20242E-08

When zoom, interval D A between the first optical system G1 and the second optical system G2, interval D B between the second optical system G2 and the aperture diaphragm FA, interval D C between aperture diaphragm FA and the 3rd optical system G3, interval D D between the 3rd optical system G3 and the 4th optical system G4, interval D E between the 4th optical system G4 and the 5th optical system G5, and the interval D F between the 5th optical system G5 and the optical filter OF changes shown in following table.

[table 2]

?	Short burnt end	The middle focal length position	Long burnt end
				f	5.20	13.49	34.93
The F number	3.69	5.50	5.40
				DA	0.50	7.06	12.87
DB	12.88	6.32	0.51
				DC	9.55	3.71	0.49
DD	1.00	6.84	10.06
				DE	1.46	4.26	8.85
DF	8.14	5.34	0.75

Value according to the condition in this example 1 is as follows:

The value that is used for the condition of example 1:

Dw＝2.40

Dt＝3.50

b2t＝-1.453

b2w＝-0.510

b3t＝-0.962

b3w＝-0.528

f2＝-9.720

f3＝14.358

The value of the condition of example 1:

(T23w/Y’)/(ft/fw)＝0.795

(Ts3w/T2sw)＝0.741

Dt/Dw＝1.458

f2/Y’＝-2.314

f3/Y’＝3.419

b2t/b2w＝2.849

b3t/b3w＝1.822

(b3t/b3w)/(b2t/b2w)＝0.640

Thereby, according to the numerical value of above-mentioned condition in the example 1 within described condition and range.

Fig. 2 to 4 shows according to the spherical aberration in the zoom lens of example shown in Figure 11, astigmatism, the aberration curve of distortion and coma.Fig. 2 is presented at the aberration curve of short burnt end (wide-angle side), and Fig. 3 is presented at the aberration curve of middle focal length position, and Fig. 4 is presented at the aberration curve of long burnt end (end of dolly-out,ing dolly-back).In the spherical aberration curve, dotted line is represented sine condition, and in the astigmatism curve, solid line is represented the sagitta of arc as the plane, and dotted line is represented meridian as the plane, and thick line is represented the d line, and fine rule is represented the g line.

Aberration curve according to shown in Fig. 2 to 4 it is found that, in the zoom lens of example shown in Figure 11, aberration is revised fully or controlled.

(example 2)

Fig. 5 shows the structure of optical system of the zoom lens of embodiment according to the present invention 2.Holding from weak point is burnt, promptly wide-angle side (WIDE) is held to long Jiao by the focal position (MEAN) of centre, and the position of each lens combination as shown in Figure 5 in the process that the end (TELE) of promptly dolly-out,ing dolly-back changes.The motion track of each lens combination also schematically is presented among Fig. 5 in the zoom process.

Zoom lens shown in Figure 5 comprise the first lens L1, the second lens L2, the 3rd lens L3, the 4th lens L4, the 5th lens L5, the 6th lens L6, the 7th lens L7, the 8th lens L8, the 9th lens L9, the tenth lens L10, the 11 lens L11, the 12 lens L12, prism PR, aperture diaphragm FA and optical filter OF.In this case, the first lens L1, prism PR, the second lens L2, and the 3rd lens L3 constitute the first optical system G1, the 4th to the 6th lens L4 constitutes the second optical system G2 to L6, the 7th to the tenth lens L7 constitutes the 3rd optical system G3 to L10, the 11 lens L11 constitutes the 4th optical system G4 individually, and the 12 lens L12 constitutes the 5th optical system G5 individually.Each optical system is supported by suitable public underframe or the like, and each optical system is integrally operated in the zoom process to change the first optical system G1, the second optical system G2, aperture diaphragm FA, the 3rd optical system G3, the 4th optical system G4, relative distance between the 5th optical system G5 and optical filter OF or interval.In Fig. 5, show the surperficial number of optical surface in the zoom lens.In addition, each reference number among Fig. 5 is used for each example independently to avoid owing to the reference number that increases causes burdensome in the accompanying drawings explanation.

In Fig. 5, constitute each optical element of the optical system of zoom lens, in series settled, for example, the first lens L1, prism PR, the second lens L2, the 3rd lens L3, the 4th lens L4, the 5th lens L5, the 6th lens L6, aperture diaphragm FA, the 7th lens L7, the 8th lens L8, the 9th lens L9, the tenth lens L10, the 11 lens L11, the 12 lens L12, and optical filter OF begun to arrange from the thing side in sequential seriesly, so that picture is imaged on the back side of optical filter OF.

The first lens L1 is a diverging meniscus lens, and it has in the aspheric surface of picture side and at the convex surface of thing side.Prism PR is used as the deflecting optical element of deflection optical path.Prism PR reflected light path and with its deflection, for example, 90 degree.The second lens L2 is a positive lens, and it all has convex surface in the thing side with as the side both sides.The 3rd lens L3 is a positive lens, and it all has convex surface in both sides.The first lens L1, prism PR, the second lens L2 and the 3rd lens L3 constitute the first optical system G1 with positive focal length, and operation in groups in the zoom process.In this case, the first optical system G1 does not move in the fixed position when zoom.

The 4th lens L4 has concave surface and wherein is formed aspheric negative lens at the concave surface as side in both sides.The 5th lens L5 is that the negative lens and the 6th lens L6 that have concave surface in both sides are the positive lenss that has convex surface in both sides.The 5th lens L5 and the 6th lens L6 closely are attached to each other, and by integrally bonding to form the cemented lens that forms by these two lens.The the 4th to the 6th lens L4 constitutes the second optical system G2 with negative focal length and operates in groups when the zoom to L6.

Aperture diaphragm FA operates individually when zoom.

In the process of the magnification that between short burnt end (wide-angle side) and long burnt end (end of dolly-out,ing dolly-back), changes zoom lens, the interval D A between the optical element in the zoom lens, DB, DC, DD, DE and DF are variable.Interval D A be the first optical system G1 on the surface of the most close picture side of the first optical system G1, promptly the 3rd lens L3 the picture side the surface

(9), with the second optical system G2 on the surface of the most close thing side, i.e. the interval of the 4th lens L4 between the surface (10) of thing side.Interval D B be the second optical system G2 on the surface of the most close picture side of the second optical system G2, i.e. the interval of the 6th lens L6 between the surface (15) of picture surface (14) of side and aperture diaphragm FA.Interval D C be surface (15) and the 3rd optical system G3 of aperture diaphragm FA on the surface of the most close thing side of the 3rd optical system G3, i.e. the interval of the 7th lens L7 between the surface (16) of thing side.Interval D D is the surface of the 3rd optical system G3 in the most close picture side of the 3rd optical system G3, promptly the tenth lens L10 is on the surface (22) of picture side, with the 4th optical system G4 on the surface of the most close thing side, i.e. the interval of the 11 lens L11 between the surface (23) of thing side.Interval D E is the surface of the 4th optical system G4 in the most close picture side of the 4th optical system G4, promptly the 11 lens L11 is on the surface (24) of picture side, with the 5th optical system G5 on the surface of the most close thing side, i.e. the interval of the 12 lens L12 between the surface (25) of thing side.Interval D F be the 5th optical system G5 on the surface of the most close picture side of the 5th optical system G5, promptly the 12 lens L12 is at the surface (26) of picture side, and the interval of optical filter OF between the surface (27) of the most close thing side.

When holding the magnification that changes zoom lens to dolly-out,ing dolly-back from wide-angle side, the second optical system G2, aperture diaphragm FA, the 3rd optical system G3, and the 5th optical system G5 be moved so that the interval D A between the first optical system G1 and the second optical system G2 little by little increases, interval D B between the second optical system G2 and the aperture diaphragm FA little by little reduces, interval D C between aperture diaphragm FA and the 3rd optical system G3 little by little reduces, interval D D between the 3rd optical system G3 and the 4th optical system G4 little by little increases, interval D E between the 4th optical system G4 and the 5th optical system G5 little by little increases, and the interval D F between the 5th optical system G5 and the optical filter OF little by little reduces.

When from wide-angle side moving when the end of dolly-out,ing dolly-back changes the magnification of zoom lens, the second optical system G2 is roughly monotonously to the picture side shifting, aperture diaphragm FA once was moved to the thing side, move on to the picture side then, the 3rd optical system G3 is to the thing side shifting, and the 5th optical system G5 is roughly monotonously to the picture side shifting.

In example 2, the focal distance f of zoom lens and F value F change in 5.71 scopes at f=5.19 to 35.05 and F=3.82 respectively.The optical property of each optical element is shown in following table.

[table 3]

In table 3, asterisk represents that this surface is an aspheric surface.That is, second surface, the 11 surface, the 16 surface, the 22 surface, the 24 surface, and each of the 25 surface all be aspheric surface, and as follows for the parameter in each aspheric equation (9).

Aspheric surface: second surface

K＝-2.95802E-05

A ₄＝-4.14571E-07

A ₆＝3.44622E-09

A ₈＝-3.41502E-11

Aspheric surface: the 11 surface

K＝-3.85674E-05

A ₄＝1.37916E-06

A ₆＝-4.03783E-08

A ₈＝4.34243E-10

Aspheric surface: the 16 surface

K＝-5.39246E-05

A ₄＝7.86322E-07

A ₆＝-4.46790E-08

A ₈＝8.13937E-10

Aspheric surface: the 22 surface

K＝2.31019E-05

A ₄＝1.42982E-06

A ₆＝-3.67689E-07

A ₈＝7.19641E-09

Aspheric surface: the 24 surface

K＝1.63010E-04

A ₄＝4.29213E-06

A ₆＝-1.93397E-08

A ₈＝1.76094E-09

Aspheric surface: the 25 surface

K＝1.15198E-04

A ₄＝7.39314E-06

A ₆＝-2.38598E-07

A ₈＝3.98643E-09

[table 4]

?	Short burnt end	The middle focal length position	Long burnt end
				f	5.19	13.53	35.05
The F number	3.82	4.92	5.71
				DA	0.55	7.95	14.91
DB	18.52	5.70	0.48
				DC	5.63	5.16	0.48
DD	1.00	6.89	9.83
				DE	1.45	5.19	9.01
DF	8.11	4.37	0.55

Value according to condition in this example 2 is as follows:

The value that is used for the condition of example 2:

Dw＝2.80

Dt＝3.50

b2t＝-1.377

b2w＝-0.482

b3t＝-0.907

b3w＝-0.497

f2＝-10.640

f3＝15.002

The value of the condition of example 2:

(T23w/Y’)/(ft/fw)＝0.852

(Ts3w/T2sw)＝0.304

Dt/Dw＝1.250

f2/Y’＝-2.533

f3/Y’＝3.572

b2t/b2w＝2.858

b3t/b3w＝1.826

(b3t/b3w)/(b2t/b2w)＝0.639

Thereby, according to the numerical value of above-mentioned condition in the example 2 within described condition and range.

Fig. 6 to 8 shows according to the spherical aberration in the zoom lens of example shown in Figure 52, astigmatism, the aberration curve of distortion and coma.Fig. 6 is presented at the aberration curve of short burnt end (wide-angle side), and Fig. 7 is presented at the aberration curve of middle focal length position, and Fig. 8 is presented at the aberration curve of long burnt end (end of dolly-out,ing dolly-back).In the spherical aberration curve, dotted line is represented sine condition, and in the astigmatism curve, solid line is represented the sagitta of arc as the plane, and dotted line is represented meridian as the plane, and thick line is represented the d line, and fine rule is represented the g line.

Aberration curve according to shown in Fig. 6 to 8 it is found that, in the zoom lens of example shown in Figure 52, aberration is revised fully or controlled.

(example 3)

Fig. 9 shows the structure of optical system of the zoom lens of embodiment according to the present invention 3.Holding from short Jiao, that is, wide-angle side (WIDE) is held to long Jiao by middle focal position (MEAN), and the position of each lens combination as shown in Figure 9 in the process that the end (TELE) of promptly dolly-out,ing dolly-back changes.The motion track of each lens combination also schematically is presented among Fig. 9 in the zoom process.

Zoom lens shown in Figure 9 comprise the first lens L1, the second lens L2, the 3rd lens L3, the 4th lens L4, the 5th lens L5, the 6th lens L6, the 7th lens L7, the 8th lens L8, the 9th lens L9, the tenth lens L10, the 11 lens L11, the 12 lens L12, prism PR, aperture diaphragm FA and optical filter OF.In this case, the first lens L1, prism PR, the second lens L2, and the 3rd lens L3 constitute the first optical system G1, the 4th to the 6th lens L4 constitutes the second optical system G2 to L6, the 7th to the tenth lens L7 constitutes the 3rd optical system G3 to L10, the 11 lens L11 constitutes the 4th optical system G4 individually, and the 12 lens L12 constitutes the 5th optical system G5 individually.Each optical system is supported by suitable public underframe or the like, and each optical system is integrally operated in the zoom process to change the first optical system G1, the second optical system G2, aperture diaphragm FA, the 3rd optical system G3, the 4th optical system G4, relative distance between the 5th optical system G5 and optical filter OF or interval.

In Fig. 9, show the surperficial number of optical surface in the zoom lens.In addition, each reference number among Fig. 9 is used for each example independently to avoid owing to the reference number that increases causes burdensome in the accompanying drawings explanation.

In Fig. 9, constitute each optical element of the optical system of zoom lens, in series settled, for example, the first lens L1, prism PR, the second lens L2, the 3rd lens L3, the 4th lens L4, the 5th lens L5, the 6th lens L6, aperture diaphragm FA, the 7th lens L7, the 8th lens L8, the 9th lens L9, the tenth lens L10, the 11 lens L11, the 12 lens L12, and optical filter OF begun to arrange from the thing side in sequential seriesly, so that picture is imaged on the back side of optical filter OF.

The first lens L1 is a diverging meniscus lens, and it has in the aspheric surface of picture side and at the convex surface of thing side.Prism PR is used as the deflecting optical element of deflection optical path.Prism PR reflected light path and with its deflection, for example, 90 degree.The second lens L2 is a positive lens, and it all has convex surface in the thing side with as the side both sides.The 3rd lens L3 is a positive meniscus lens, and it has convex surface in described thing side.The first lens L1, prism PR, the second lens L2 and the 3rd lens L3 constitute the first optical system G1 with positive focal length, and operation in groups in the zoom process.In this case, the first optical system G1 does not move in the fixed position when zoom.

The 7th lens L7 is the positive meniscus lens that has the aspheric surface convex surface in the thing side.The 8th lens L8 is that the positive lens and the 9th lens L9 that have convex surface in both sides are the negative lenses that has concave surface in both sides.The 8th lens L8 and the 9th lens L9 closely are attached to each other, and by integrally bonding to form the cemented lens that forms by these two lens.The tenth lens L10 has convex surface and wherein is formed aspheric positive lens at the convex surface as side in both sides.Above-mentioned the 7th to the tenth lens L7 constitutes the 3rd optical system G3 with positive focal length and operates in groups when the zoom to L10.

The 11 lens L11 is a diverging meniscus lens, and it has as the aspheric surface of side and be formed the shape of protruding to the thing side.The 11 lens L11 constitutes the 4th optical system G4 with negative focal length individually and operates in groups when zoom.In this case, the 4th optical system G4 does not move in the fixed position when zoom.

The 12 lens L12 has convex surface and wherein is formed aspheric positive lens at the convex surface of thing side in both sides.The 12 lens L12 constitutes the 5th optical system G5 with positive focal length individually and become operation when zoom.

In the process of the magnification that between short burnt end (wide-angle side) and long burnt end (end of dolly-out,ing dolly-back), changes zoom lens, the interval D A between the optical element in the zoom lens, DB, DC, DD, DE and DF are variable.Interval D A is the surface of the first optical system G1 in the most close picture side of the first optical system G1, promptly the 3rd lens L3 is on the surface (9) of picture side, with the second optical system G2 on the surface of the most close thing side, i.e. the interval of the 4th lens L4 between the surface (10) of thing side.Interval D B be the second optical system G2 on the surface of the most close picture side of the second optical system G2, i.e. the interval of the 6th lens L6 between the surface (15) of picture surface (14) of side and aperture diaphragm FA.Interval D C be surface (15) and the 3rd optical system G3 of aperture diaphragm FA on the surface of the most close thing side of the 3rd optical system G3, i.e. the interval of the 7th lens L7 between the surface (16) of thing side.Interval D D is the surface of the 3rd optical system G3 in the most close picture side of the 3rd optical system G3, promptly the tenth lens L10 is on the surface (22) of picture side, with the 4th optical system G4 on the surface of the most close thing side, i.e. the interval of the 11 lens L11 between the surface (23) of thing side.Interval D E is the surface of the 4th optical system G4 in the most close picture side of the 4th optical system G4, promptly the 11 lens L11 is on the surface (24) of picture side, with the 5th optical system G5 on the surface of the most close thing side, i.e. the interval of the 12 lens L12 between the surface (25) of thing side.Interval D F be the 5th optical system G5 on the surface of the most close picture side of the 5th optical system G5, promptly the 12 lens L12 is at the surface (26) of picture side, and the interval of optical filter OF between the surface (27) of the most close thing side.

When from wide-angle side moving when the end of dolly-out,ing dolly-back changes the magnification of zoom lens, the second optical system G2 is roughly monotonously to the picture side shifting, the 3rd optical system G3 is roughly monotonously to the thing side shifting, and the 5th optical system G5 is roughly monotonously to the picture side shifting.

In example 3, the focal distance f of zoom lens and F value F change in 5.79 scopes at f=5.20 to 34.98 and F=3.62 respectively.The optical property of each optical element is shown in following table.

[table 5]

In table 5, asterisk represents that this surface is an aspheric surface.That is, second surface, the 11 surface, the 16 surface, the 22 surface, the 24 surface, and each of the 25 surface all be aspheric surface, and as follows for the parameter in each aspheric equation (9).

Aspheric surface: second surface

K＝-2.73941E-05

A ₄＝-5.56990-07

A ₆＝5.77314E-09

A ₈＝-4.10151E-11

Aspheric surface: the 11 surface

K＝-5.23771E-06

A ₄＝1.27345E-06

A ₆＝6.12964E-08

A ₈＝-1.67148E-09

Aspheric surface: the 16 surface

K＝-2.76178E-05

A ₄＝1.03357E-06

A ₆＝-2.95254E-08

A ₈＝6.46288E-10

Aspheric surface: the 22 surface

K＝1.77835E-04

A ₄＝8.92306E-06

A ₆＝-8.94259E-07

A ₈＝1.85251E-08

Aspheric surface: the 24 surface

K＝6.56471E-05

A ₄＝1.60998E-05

A ₆＝-7.66122E-07

A ₈＝1.46091E-08

Aspheric surface: the 25 surface

K＝-2.32383E-05

A ₄＝2.50045E-05

A ₆＝-1.03941E-06

A ₈＝1.65508E-08

[table 6]

?	Short burnt end	The middle focal length position	Long burnt end
				f	5.20	13.50	34.98
The F number	3.62	5.48	5.79
				DA	0.50	6.86	11.59
DB	11.59	5.23	0.50
				DC	12.00	5.93	0.50
DD	1.00	7.07	12.50
				DE	1.43	3.78	7.43
DF	6.50	4.15	0.50

Value according to condition in this example 3 is as follows:

The value that is used for the condition of example 3:

Dw＝2.50

Dt＝3.80

b2t＝-1.446

b2w＝-0.554

b3t＝-1.157

b3w＝-0.568

f2＝-9.967

f3＝15.311

The value of the condition of example 3:

(T23w/Y’)/(ft/fw)＝0.835

(Ts3w/T2sw)＝1.035

Dt/Dw＝1.520

f2/Y’＝-2.373

f3/Y’＝3.645

b2t/b2w＝2.608

b3t/b3w＝2.036

(b3t/b3w)/(b2t/b2w)＝0.780[0057]

Thereby, according to the numerical value of above-mentioned condition in the example 3 within described condition and range.

Figure 10 to 12 shows according to the spherical aberration in the zoom lens of example shown in Figure 93, astigmatism, the aberration curve of distortion and coma.Figure 10 is presented at the aberration curve of short burnt end (wide-angle side), and Figure 11 is presented at the aberration curve of middle focal length position, and Figure 12 is presented at the aberration curve of long burnt end (end of dolly-out,ing dolly-back).In the spherical aberration curve, dotted line is represented sine condition, and in the astigmatism curve, solid line is represented the sagitta of arc as the plane, and dotted line is represented meridian as the plane, and thick line is represented the d line, and fine rule is represented the g line.

Aberration curve according to shown in Figure 10 to 12 it is found that, in the zoom lens of example shown in Figure 93, aberration is revised fully or controlled.

(example 4)

Figure 13 shows the structure of optical system of the zoom lens of embodiment according to the present invention 3.Holding from short Jiao, that is that wide-angle side (WIDE) is held to long Jiao by middle focal position (MEAN), and the position of each lens combination as shown in figure 13 in the process that the end (TELE) of promptly dolly-out,ing dolly-back changes.The motion track of each lens combination also schematically is presented among Figure 13 in the zoom process.

In this case, zoom lens further comprise for example the 6th optical system of the 6th lens combination.

Zoom lens shown in Figure 13 comprise the first lens L1, the second lens L2, the 3rd lens L3, the 4th lens L4, the 5th lens L5, the 6th lens L6, the 7th lens L7, the 8th lens L8, the 9th lens L9, the tenth lens L10, the 11 lens L11, the 12 lens L12, the 13 lens L13, prism PR, aperture diaphragm FA and optical filter OF.

In this case, the first lens L1, prism PR, the second lens L2, and the 3rd lens L3 constitutes the first optical system G1, the the 4th to the 6th lens L4 constitutes the second optical system G2 to L6, the the 7th to the tenth lens L7 constitutes the 3rd optical system G3 to L10, and the 11 lens L11 constitutes the 4th optical system G4 individually, the 12 lens L12 constitutes the 5th optical system G5 individually, and the 13 lens L13 constitutes the 6th optical system G6 individually.Each optical system is supported by suitable public underframe or the like, and each optical system is integrally operated in the zoom process to change the first optical system G1, the second optical system G2, aperture diaphragm FA, the 3rd optical system G3, the 4th optical system G4, the 5th optical system G5, relative distance between the 6th optical system G6 and optical filter OF or interval.

In Figure 13, show the surperficial number of optical surface in the zoom lens.In addition, each reference number among Figure 13 is used for each example independently to avoid owing to the reference number that increases causes burdensome in the accompanying drawings explanation.

In Figure 13, constitute each optical element of the optical system of zoom lens, in series settled, for example, the first lens L1, prism PR, the second lens L2, the 3rd lens L3, the 4th lens L4, the 5th lens L5, the 6th lens L6, aperture diaphragm FA, the 7th lens L7, the 8th lens L8, the 9th lens L9, the tenth lens L10, the 11 lens L11, the 12 lens L12, the 13 lens L13, and optical filter OF begun to arrange from the thing side in sequential seriesly, so that picture is imaged on the back side of optical filter OF.

The first lens L1 is a diverging meniscus lens, and it has in the aspheric surface of picture side and at the convex surface of thing side.Prism PR is used as the deflecting optical element of deflection optical path.Prism PR reflected light path and with its deflection, for example, 90 degree.The second lens L2 is a positive lens, and it all has convex surface in the thing side with as the side both sides.The 3rd lens L3 is a positive meniscus lens, and it has convex surface in the thing side.

The first lens L1, prism PR, the second lens L2 and the 3rd lens L3 constitute the first optical system G1 with positive focal length, and operation in groups in the zoom process.In this case, the first optical system G1 does not move in the fixed position when zoom.

The 11 lens L11 has concave surface and wherein is formed aspheric negative lens at the concave surface as side in both sides.The 11 lens L11 constitutes the 4th optical system G4 with negative focal length individually and operates in groups when zoom.In this case, when zoom, it is static that the 4th optical system G4 keeps, that is, do not move in the fixed position.

The 13 lens L13 is a diverging meniscus lens, and it has in the aspheric surface of thing side and forms the form of protruding to the picture side.The 12 lens L12 constitutes the 5th optical system G5 with positive focal length individually and operates in groups when zoom.The 13 lens L13 constitutes the 6th optical system and the operation in groups with negative focal length individually.In this case, the 6th optical system integrally is arranged on the optical filter OF, and in the zoom process, does not move in the fixed position.

In the process of the magnification that between short burnt end (wide-angle side) and long burnt end (end of dolly-out,ing dolly-back), changes zoom lens, the interval D A between the optical element in the zoom lens, DB, DC, DD, DE and DF are variable.Interval D A is the surface of the first optical system G1 in the most close picture side of the first optical system G1, promptly the 3rd lens L3 is on the surface (9) of picture side, with the second optical system G2 on the surface of the most close thing side, i.e. the interval of the 4th lens L4 between the surface (10) of thing side.Interval D B be the second optical system G2 on the surface of the most close picture side of the second optical system G2, i.e. the interval of the 6th lens L6 between the surface (15) of picture surface (14) of side and aperture diaphragm FA.Interval D C be surface (15) and the 3rd optical system G3 of aperture diaphragm FA on the surface of the most close thing side of the 3rd optical system G3, i.e. the interval of the 7th lens L7 between the surface (16) of thing side.Interval D D is the surface of the 3rd optical system G3 in the most close picture side of the 3rd optical system G3, promptly the tenth lens L10 is on the surface (22) of picture side, with the 4th optical system G4 on the surface of the most close thing side, i.e. the interval of the 11 lens L11 between the surface (23) of thing side.Interval D E is the surface of the 4th optical system G4 in the most close picture side of the 4th optical system G4, promptly the 11 lens L11 is on the surface (24) of picture side, with the 5th optical system G5 on the surface of the most close thing side, i.e. the interval of the 12 lens L12 between the surface (25) of thing side.Interval D F be the 5th optical system G5 on the surface of the most close picture side of the 5th optical system G5, promptly the 12 lens L12 is at the surface (26) of picture side, and the interval of the 13 lens L13 between the surface (27) of thing side.

When holding the magnification that changes zoom lens to dolly-out,ing dolly-back from wide-angle side, the second optical system G2, the 3rd optical system G3, and the 5th optical system G5 is moved so that the interval D A between the first optical system G1 and the second optical system G2 little by little increases, interval D B between the second optical system G2 and the aperture diaphragm FA little by little reduces, interval D C between aperture diaphragm FA and the 3rd optical system G3 little by little reduces, interval D D between the 3rd optical system G3 and the 4th optical system G4 little by little increases, interval D E between the 4th optical system G4 and the 5th optical system G5 little by little increases, and the interval D F between the 5th optical system G5 and the 6th optical system little by little reduces.

When moving when wide-angle side is held the magnification that changes zoom lens to dolly-out,ing dolly-back, the second optical system G2 is roughly monotonously to the picture side shifting, and the 3rd optical system G3 is roughly monotonously to the thing side shifting, and the 5th optical system G5 is roughly monotonously to the picture side shifting.

In example 4, the focal distance f of zoom lens and F value F change in 5.85 scopes at f=5.21 to 35.01 and F=3.58 respectively.The optical property of each optical element is shown in following table.

[table 7]

In table 7, asterisk represents that this surface is an aspheric surface.That is, second surface, the 11 surface, the 16 surface, the 22 surface, the 24 surface, each of the 25 surface and the 27 surface all is aspheric surface, and as follows for the parameter in each aspheric equation (9).

Aspheric surface: second surface

K＝-2.71728E-06

A ₄＝-3.58900E-07

A ₆＝1.70392E-09

A ₈＝4.11931E-13

Aspheric surface: the 11 surface

K＝-1.24369E-04

A ₄＝1.17040E-06

A ₆＝-9.36061E-08

A ₈＝-1.94537E-09

Aspheric surface: the 16 surface

K＝-5.03986E-05

A ₄＝1.88819E-07

A ₆＝-4.04258E-09

A ₈＝4.05202E-11

Aspheric surface: the 22 surface

K＝2.35721E-04

A ₄＝1.56156E-06

A ₆＝-1.45635E-07

A ₈＝2.75915E-09

Aspheric surface: the 24 surface

K＝3.77794E-04

A ₄＝1.16807E-05

A ₆＝6.58942E-07

A ₈＝-4.47280E-08

Aspheric surface: the 25 surface

K＝1.70399E-04

A ₄＝2.68367E-05

A ₆＝1.09834E-08

A ₈＝-3.07464E-08

Aspheric surface: the 27 surface

K＝3.59460E-04

A ₄＝-5.08998E-05

A ₆＝1.62131E-06

A ₈＝0.00000E+00

When zoom, interval D A between the first optical system G1 and the second optical system G2, interval D B between the second optical system G2 and the aperture diaphragm FA, interval D C between aperture diaphragm FA and the 3rd optical system G3, interval D D between the 3rd optical system G3 and the 4th optical system G4, interval D E between the 4th optical system G4 and the 5th optical system G5, and the interval D F between the 5th optical system G5 and the 6th optical system G6 changes shown in following table.

[table 8]

?	Short burnt end	The middle focal length position	Long burnt end
				f	5.21	13.50	35.01
The F number	3.58	5.69	5.85
				DA	0.89	5.00	8.83
DB	8.57	4.46	0.63
				DC	11.19	5.75	0.50
DD	5.42	10.86	16.11
				DE	1.00	3.35	3.48
DF	3.02	0.67	0.54

[0069]

Value according to condition in this example 4 is as follows:

The value that is used for the condition of example 4:

Dw＝2.50

Dt＝3.60

b2t＝-1.550

b2w＝-0.562

b3t＝-1.328

b3w＝-0.627

f2＝-7.001

f3＝13.908

The value of the condition of example 4:

(T23w/Y’)/(ft/fw)＝0.700

(Ts3w/T2sw)＝1.306

Dt/Dw＝1.440

f2/Y’＝-1.667

f3/Y’＝3.311

b2t/b2w＝2.757

b3t/b3w＝2.119

(b3t/b3w)/(b2t/b2w)＝0.768

Thereby, according to the numerical value of above-mentioned condition in the example 4 within described condition and range.

Figure 14 to 16 shows according to the spherical aberration in the zoom lens of example shown in Figure 13 4, astigmatism, the aberration curve of distortion and coma.Figure 14 is presented at the aberration curve of short burnt end (wide-angle side), and Figure 15 is presented at the aberration curve of middle focal length position, and Figure 16 is presented at the aberration curve of long burnt end (end of dolly-out,ing dolly-back).In the spherical aberration curve, dotted line is represented sine condition, and in the astigmatism curve, solid line is represented the sagitta of arc as the plane, and dotted line is represented meridian as the plane, and thick line is represented the d line, and fine rule is represented the g line.

Aberration curve according to shown in Figure 14 to 16 it is found that, in the zoom lens of example shown in Figure 13 4, aberration is revised fully or controlled.

[second embodiment]

Next, will be used as example 5 according to the zoom lens of second embodiment of the invention describes in detail with reference to the accompanying drawings to 10.

Figure 17 and 21 shows the sectional view according to the structure of the zoom lens of second embodiment.Figure 17 shows the structure of the zoom lens of example 5, and Figure 21 shows the structure of the zoom lens of example 6.

Zoom lens according to example 5 comprise five lens combination, that is, " just, negative, just, negative and just " lens combination G1 is to G5.In these zoom lens, the second lens combination G2 is as the so-called variator of the function of the magnification with main change zoom lens.The 3rd lens combination G3 and lens group thereafter also are configured to have the function of the magnification that changes zoom lens, so that the burden of second lens combination on magnification changes is reduced, even and the aberration correction also guarantees to revise the degree of freedom of aberration owing to high variable power being arranged than the difficulty that becomes.The 5th lens combination is followed the change in location of the imaging surface that changes magnification as so-called compensator with correction, and the 4th lens combination has the function that moves forward into line focusing along with object point.The first lens combination G1 and the 4th lens combination G4 are fixed when changing the magnification of zoom lens, promptly, do not move, so that can prevent the large scale of lens drum unit, even and when the number of the optical element of lens combination is relatively big, also realize extensive angle and high variable power ratio.

According to the zoom lens of second embodiment of the invention, shown in following example (example 5 and 6), can provide to have undersized body and the zoom lens revised fully of aberration wherein.So, use above zoom lens, can provide individual from all having undersized body and high performance imaging device, camera and personal digital assistant.

Because the small size of body, can dwindle and to reduce the number realization of element energy-conservation by component size.

The instance interpretation second embodiment of the present invention as follows, will be with two of zoom lens concrete.

In following example, as shown in figure 17, zoom lens can comprise optical element, and it is positioned in the picture side of the 5th lens combination G5 and forms with the parallel-plate form.For instance, optical element can be, such as the optics low pass filter, the optical filter of cutoff filter or the like, or, being equivalent to transparent parallel-plate of above element or the like such as the cover glass (seal glass) of the light receiving element of ccd sensor, it is called as parallel-plate P.

Figure 17 shows according to the structure of the zoom lens of example 5 and the zoom motion track when holding change magnification by the middle focal length position to dolly-out,ing dolly-back from wide-angle side.

In Figure 17, zoom lens comprise the first lens combination G1 with positive refractive power, have the second lens combination G2 of negative refractive power, have the 3rd lens combination G3 of positive refractive power, have the 4th lens combination G4 of negative refractive power, and the 5th lens combination G5 with positive refractive power.Zoom lens further comprise the aperture diaphragm S between second lens combination and the 3rd lens combination, and parallel-plate is positioned in the back side of the 5th lens combination G5, that is, it is as side.

When holding change zoom lens magnification to dolly-out,ing dolly-back from wide-angle side, interval (A) between the first lens combination G1 and the second lens combination G2 increases, interval (B+C) between the second lens combination G2 and the 3rd lens combination G3 reduces, interval (D) between the 3rd lens combination G3 and the 4th lens combination G4 increases, interval (E) between the 4th lens combination G4 and the 5th lens combination G5 increases, and the interval (F) between the 5th lens combination G5 and the parallel-plate P reduces.

In the second embodiment of the present invention, the first lens combination G1 and the 4th lens combination G4 keep static in the zoom process, that is, do not move at stationary state.

The first lens combination G1 begins to comprise in turn the diverging meniscus lens L1 that has at the convex surface of thing side from the thing side, prism PR, and two positive lens L2, L3.

The second lens combination G2 begins to have in turn from the thing side and has aspheric negative lens L4 in both sides, and cemented lens, the positive lens L6 that wherein has the negative lens L5 of concave surface in both sides and have convex surface in both sides closely is attached to each other to form cemented lens.

Aperture diaphragm S is positioned between the second lens combination G2 and the 3rd lens combination G3, and is configured to when changing the magnification of zoom lens to the picture side shifting.

The 3rd lens combination G3 begins to be included in turn both sides from the thing side and has aspheric positive meniscus lens L7, by the positive lens L8 that all has convex surface in both sides with all have the cemented lens that the negative lens L9 of concave surface forms in both sides, and by diverging meniscus lens L10 with have the cemented lens that aspheric positive meniscus lens L11 forms as side.In positive meniscus lens L7, has aspheric surface than another stronger convex surface towards the thing side.

The 4th lens combination G4 is included in the thing side to have convex surface and has aspheric diverging meniscus lens L12 as side.

The 5th lens combination G5 is included in both sides and has aspheric positive meniscus lens L13.

According to the structure of the zoom lens among this embodiment, though when the high variable power of having used 10.1 than the time, also can revise other aberration of aberration and magnification effectively.

In a second embodiment, shown in example 5 and 6 in Figure 17 and 21, parallel-plate P is positioned between the 5th lens combination G5 and the imaging surface I.Here; parallel-plate P is corresponding to optical element; for example; optical filter; for example be configured to the low pass filter of the corresponding spatial frequency of excess of limiting resolution of solid state image sensing device that amputation for example is placed in the CCD or the like of imaging surface I, perhaps be configured to protect the cover glass of image sensering device.

[the 3rd embodiment]

Next, will be with reference to Figure 25,29,33 and 37 explain the third embodiment of the present invention.

At Figure 25, in 29,33 and 37, though basic structure is common, some elements in the imaging optical system are different, and respectively at example 7,8, show with sectional view in 9 and 10.

Following here example 7 of inciting somebody to action is as shown in figure 25 explained the zoom lens according to the 3rd embodiment particularly.

According to third embodiment of the invention zoom lens comprise six lens combination, that is, " just, negative, just negative, just and plus or minus " lens combination G1 is to G6.In these zoom lens, the second lens combination G2 is as the so-called variator of the function of the magnification with main change zoom lens.The 3rd lens combination G3 and thereafter lens group also be configured to have the function of the magnification that changes zoom lens, so that the burden of second lens combination on magnification changes is reduced, even and the aberration correction also guarantees to revise the degree of freedom of aberration owing to high variable power being arranged than the difficulty that becomes.The 5th lens combination being modified to the change in location of image surface along with changing magnification, and has the function that moves forward into line focusing along with object point as so-called compensator.The first lens combination G1, aperture diaphragm S, the 4th lens combination G4, be fixed when changing the magnification of zoom lens with the 6th lens combination, promptly, do not move, so that can prevent the large scale of lens drum unit, even and when the number of the optical element of lens combination is relatively big, also realize high variable power ratio.

Figure 25 be show the third embodiment of the present invention example 7 structure and from the sectional view of wide-angle side by the zoom motion track of a certain middle focal length position to the process of the end zoom of dolly-out,ing dolly-back.

According to the zoom lens of the 3rd embodiment optical axis along zoom lens, begin to comprise in turn the first lens combination G1 with positive refractive power from the thing side, the second lens combination G2 with negative refractive power, the 3rd lens combination G3 with positive refractive power, the 4th lens combination G4 with negative refractive power, the 5th lens combination G5 with positive refractive power has the 6th lens combination G6 of negative refractive power, and is placed in the aperture diaphragm S between the second lens combination G2 and the 3rd lens combination G3.

When holding change zoom lens magnification to dolly-out,ing dolly-back from wide-angle side, interval (A) between the first lens combination G1 and the second lens combination G2 increases, interval (B+C) between the second lens combination G2 and the 3rd lens combination G3 reduces, interval (D) between the 3rd lens combination G3 and the 4th lens combination G4 increases, interval (E) between the 4th lens combination G4 and the 5th lens combination G5 increases, and the interval (F) between the 5th lens combination G5 and the 6th lens combination G6 reduces.

In the third embodiment of the present invention, the first lens combination G1, aperture diaphragm S, each of the 4th lens combination G4 and the 6th lens combination G6 all do not move at stationary state in the zoom process.The first lens combination G1 begins to comprise in turn to have at the convex surface of thing side with at the aspheric diverging meniscus lens L1 as side, prism PR, and two positive lens L2, L3 from the thing side.

The second lens combination G2 begins to have in turn from the thing side and has concave surface in both sides and wherein be formed aspheric negative lens L4 at the concave surface as side, and cemented lens, the positive lens L6 that wherein has the negative lens L5 of concave surface in both sides and have convex surface in both sides closely is attached to each other to form cemented lens.

Aperture diaphragm S is positioned between the second lens combination G2 and the 3rd lens combination G3.

The 3rd lens combination G3 is included in that the thing side has aspheric surface and wherein than the positive meniscus lens L7 of another stronger convex surface towards the thing side, by the positive lens L8 that all has convex surface in both sides with all have the cemented lens that the negative lens L9 of concave surface forms in both sides, and the positive lens L10 that has convex surface in both sides.

The 4th lens combination G4 is included in the thing side to have convex surface and has aspheric diverging meniscus lens L11 as side.

The 5th lens combination G5 is included in both sides all to have convex surface and wherein is formed aspheric positive meniscus lens L12 at the convex surface of thing side.

The 6th lens combination G6 comprises diverging meniscus lens L13, and it has in the aspheric surface of thing side and at the convex surface as side.

In the 3rd embodiment, as by shown in example 7 and 10, parallel-plate P is positioned between the 6th lens combination G6 and the imaging surface I.Here; parallel-plate P is corresponding to optical element; for example; optical filter; for example be configured to the low pass filter of the corresponding spatial frequency of excess of limiting resolution of solid state image sensing device that amputation for example is placed in the CCD or the like of imaging surface I, perhaps be configured to protect the cover glass of image sensering device.

Zoom lens according to a second embodiment of the present invention comprise first lens combination with positive refractive power, first lens combination does not move when changing the magnification of zoom lens, second lens combination with negative refractive power, the 3rd lens combination with positive refractive power, the 4th lens combination with negative refractive power, the 4th lens combination G4 does not move when changing the magnification of zoom lens, and the 5th lens combination G5 with positive refractive power, first to the 5th lens combination begins to arrange in turn along the optical axis of zoom lens from the thing side.When holding the magnification that changes zoom lens to dolly-out,ing dolly-back from wide-angle side, at least the second lens combination G2, the 3rd lens combination G3, and the 5th lens combination G5 is moved to carry out the magnification change.The 3rd lens combination G3 has at least two adhesive surfaces.Thereby,, then can realize thin body and the undersized body on the optical axis direction if these zoom lens are used in digital camera or the like.The 3rd lens combination G3 has at least two adhesive surfaces so that can be revised effectively as the aberration of the magnification of the problem that produces in the traditional zoom lens with high variable power ratio.Here, the first lens combination G1 reflective optical devices that can have crooked light path.

According to the zoom lens of second embodiment, preferably meeting the following conditions:

Wherein f1 is the focal length of first lens combination, and fw is the focal lengths of zoom lens in wide-angle side, and ft is that zoom lens are at the focal length of end of dolly-out,ing dolly-back.By satisfying above condition (10), can suitably set the focal length of the first lens combination G1.If the lower limit of value greater than condition (10), the refractive power that then can prevent first lens combination are too big and can prevent the appearance of aberration.If the upper limit of value less-than condition (10) can guarantee suitably that then the positive refractive power of first lens combination consequently can shorten total length of zoom lens.

In zoom lens according to a second embodiment of the present invention, preferably meeting the following conditions:

Wherein f2 is the focal length of second lens combination, and fw is the focal lengths of zoom lens in wide-angle side, and ft is that zoom lens are at the focal length of end of dolly-out,ing dolly-back.

By satisfying above condition (11), can suitably set the focal length of second lens combination.If the lower limit of value greater than condition (11), the amount of movement that then can suitably keep the negative refractive power of second lens combination and can reduce by second lens combination is with the zoom ratio that obtains expectation so that total length that can shorten zoom lens.If the upper limit of value less-than condition (11) then can prevent the too big refractive power of second lens combination so that can control the appearance of the aberration of second lens combination.

Zoom lens according to a second embodiment of the present invention can comprise be configured to the aperture diaphragm that moves when changing the magnification of zoom lens.In this case, can suitably revise look coma (chromatic comaaberration).

In the zoom lens according to second embodiment of the invention, preferable is at least the second lens combination and thereafter towards all having at least one aspheric surface as each of side.In this case, can suitably revise the variation of the aberration of following the magnification change.

In zoom lens, can utilize the 4th lens combination that in the process of the magnification that changes zoom lens, does not move to focus on according to second embodiment.

In zoom lens, might realize the magnification ratio more than 5 according to second embodiment.

Can be used to the imaging device that combines with image pick-up device according to the zoom lens of second embodiment of the invention.The imaging device of the favourable effect with above zoom lens can be provided in this case.

By using these zoom lens, can realize having the camera of above favourable effect as the imaging optical system in the camera.

By using zoom lens according to second embodiment as the imaging optical system in the personal digital assistant, can provide personal digital assistant with above favourable effect.

Next, the operation of the 3rd embodiment will be explained.

Be configured to light is comprised from the object guiding imaging surface of relative long limit and relative minor face according to the zoom lens of the 3rd embodiment, and comprise first lens combination with positive refractive power, it is static that first lens combination keeps when changing the magnification of zoom lens, second lens combination with negative refractive power, the 3rd lens combination with positive refractive power, the 4th lens combination with negative refractive power, the 4th lens combination keeps static when changing the magnification of zoom lens, the 6th lens combination that has the 5th lens combination of positive refractive power and have the plus or minus refractive power, first to the 6th lens combination begins to arrange in turn along the optical axis of zoom lens from the thing side.When holding the magnification that changes zoom lens to dolly-out,ing dolly-back from wide-angle side, at least the second lens combination, the 3rd lens combination, and the 5th lens combination is moved to carry out the magnification change.First lens combination has the reflective optical devices of crooked light path.Light path is by reflective optical devices vertically being bent along imaging surface.

Thereby, be used at zoom lens under the situation of digital camera or the like, can reduce the thickness of camera at the camera optical axis direction.Imaging surface can be the image pickup surface or the optical receiving surface of for example image pick-up device of the imaging device of camera.In using the zoom lens of reflective optical devices, because first lens combination fixes with respect to imaging surface, so, need the big overall length of optical system in order to realize high variable power ratio.Yet if along the crooked light path of the short side direction of imaging surface, the camera that uses zoom lens is to form so that be difficult to dwindle zoom lens, the size of camera or the like with vertically long form.On the other hand, in zoom lens,, be placed in the horizontal of camera so that might dwindle the camera size so wherein be provided with the lens drum unit of zoom lens because light path is longitudinally crooked according to third embodiment of the invention.

In zoom lens according to this embodiment, preferably meeting the following conditions:

0.5<fw/Y’<1.4 (12)

Wherein fw is the focal lengths of zoom lens in wide-angle side, and Y ' is the maximum image height degree of zoom lens.

By satisfying above condition (12), can realize wide visual angle by zoom lens.

In zoom lens, preferably meeting the following conditions:

0.15<Lr1/Lr2<0.22 (13)

Wherein Lr1 is on the optical axis of zoom lens, distance between the surface of the most close thing side of the lens combination in the zoom lens and the reflecting surface of reflective optical devices, Lr2 is in the distance between reflecting surface and imaging surface or the image pickup surface on the optical axis of zoom lens.By satisfying above condition (13), the balance that might optimize camera size and aberration correction is to realize extensive angle.If the lower limit of value less-than condition (13), then the overall length of camera becomes greatly, and therefore becoming is difficult to reduce the horizontal camera size of camera.If the upper limit of value greater than condition (13), then the size of first lens combination becomes big, therefore dwindles the camera size and become difficult aspect thickness.

3<Lg1/fw<7 (14)

Wherein Lg1 is the thickness of first lens combination at the optical axis direction of zoom lens, and fw is the thickness of zoom lens in wide-angle side.In this case, might optimize the balance of camera size and aberration correction to realize wide visual angle.If the lower limit of value less-than condition (14), then the focal power of each optical element is too big, therefore revises aberration and becomes difficult.If the upper limit of value greater than condition (14), then the increase of the size of first lens combination consequently is difficult to dwindle the camera size aspect thickness.

1<Lr2/ft<3 (15)

Wherein ft is zoom lens at the focal length of the end of dolly-out,ing dolly-back and Lr2 is the reflecting surface of reflective optical devices on the optical axis at zoom lens and the distance between the imaging surface.In this case, might optimize the camera size of the zoom lens that high variable power ratio is arranged and the balance of aberration correction.If the lower limit of value less-than condition (15), then the focal power of each optical element is too big, consequently revises aberration and becomes difficult.If the upper limit of value greater than condition (15), then the size of zoom lens increases so that can not realize that the size of thickness aspect camera dwindles.

2<|fL1/fw|<5 (16)

Wherein fL1 is that synthetic focal length and the fw that is placed at least one optical element on the thing side of reflective optical devices is the focal lengths of zoom lens in wide-angle side.In this case, might optimize the balance of camera size and aberration correction to realize wide visual angle.If the lower limit of value less-than condition (16), then the focal power of each optical element is too big, consequently revises aberration and becomes difficult.If the upper limit of value greater than condition (15), then the size of zoom lens increases so that can not realize that the size of thickness aspect camera dwindles.

The zoom lens that meet this embodiment can comprise aperture diaphragm, and preferably meeting the following conditions:

0.3<Tap/T<0.7 (17)

Wherein Tap is the surface of the most close thing side of zoom lens on the optical axis of zoom lens and the distance between the aperture diaphragm, and T is the overall length of zoom lens along the optical axis of zoom lens, for example, and the surface of the most close thing side and the distance between the imaging surface.In this case, might set the condition that relates to the aperture diaphragm position.If the lower limit of value less-than condition (16), then the focal power of each optical element of aperture diaphragm back becomes too big, consequently revises aberration and becomes difficult.If the upper limit of value greater than condition (15), then the size of first lens combination increases so that can not realize that the size of camera dwindles.

Comprise under image pick-up device and the situation at imaging device, the imaging device of the favourable effect with above zoom lens can be provided according to the zoom lens of this embodiment.

Under camera comprises the situation of zoom lens as imaging optical system according to this embodiment, can provide the camera of favourable effect with above zoom lens.

Comprise that at personal digital assistant the imaging optical system of camera-enabled and this imaging optical system are under the situation according to the zoom lens of this embodiment, the personal digital assistant with above favourable effect can be provided.

With reference to Figure 17 and 21 of 5 and 6 as an example, describe various examples in detail with respectively according to the zoom lens of second embodiment of the invention based on concrete Numerical examples.Figure 17 and 21 is presented at the structure of zoom lens in the magnification process that changes zoom lens and the motion track of lens combination with sectional view.

As described below, the aberration in the zoom lens of following example is revised fully.Since according to the structure of the zoom lens of this embodiment, can realize the wide half angle of view of 38 degree, the variable power ratio more than 5, undersized body, and for 5 * 10 ⁶To 10 ⁷The corresponding high-resolution fabulous performance of pixel, in the example below.

The reference number of Shi Yonging is expressed as follows hereinafter:

F: total focal length of lens combination

F (F number): F number (F value)

ω: half angle of view (degree)

R: radius-of-curvature

A, B, C, D, E, F: variable interval

Nd: refractive index

Vd: Abbe number

K: the aspheric constant of the cone

A4: quadravalence asphericity coefficient

A6: six rank asphericity coefficients

A8: eight rank asphericity coefficients

A10: ten rank asphericity coefficients

x = \frac{{CH}^{2}}{1 + \sqrt{1 - (K + 1) C^{2} H^{2}}} + A_{4} \cdot H^{4} + A_{6} \cdot H^{6} + A_{8} \cdot H^{8} + A_{10} \cdot H^{10} - - - (18)

In the following drawings, show spherical aberration, astigmatism, distortion, and the aberration curve of coma.In the spherical aberration curve, dotted line is represented sine condition, and in the astigmatism curve, solid line is represented the sagitta of arc as the plane, and dotted line is represented meridian as the plane, and thick line is represented d line (587.56nm), and fine rule is represented g line (435.83nm).

In following example, use identical reference number.Though usually use for example focal length, radius-of-curvature, spaced surface, or the like long measure " mm ", optical system is not restricted to it, and because identical optical property, can be amplified pari passu or dwindle.

(example 5)

Figure 17 is the sectional view that shows the zoom lens structure of example 5 according to a second embodiment of the present invention.

The zoom lens of example 5 are in wide-angle side, in the middle focal length position, and are presented at the upside of Figure 17, centre, and downside respectively in the structure of the end of dolly-out,ing dolly-back.

Because lens arrangement has been described above, those are omitted in the following description.

When from wide-angle side (short burnt end) during to the magnification of the end of dolly-out,ing dolly-back (long burnt end) change zoom lens, interval (A) between the first lens combination G1 and the second lens combination G2 increases, interval (B+C) between the second lens combination G2 and the 3rd lens combination G3 reduces, interval (D) between the 3rd lens combination G3 and the 4th lens combination G4 increases, and the interval (E) of the 4th lens combination G4 and the 5th lens combination G5 increases.

In wide-angle side with in the process of the magnification that changes zoom lens between the end of dolly-out,ing dolly-back, the interval A in the zoom lens between the optical element, B, C, D, E and F are variable.At interval A be the first optical system G1 on the surface of the most close picture side of the first optical system G1, promptly the 3rd lens L3 is on the surface (9) of picture side, and the interval of the second optical system G2 between the surface (10) of the most close thing side.At interval B be the second optical system G2 on the surface of the most close picture side of the second optical system G2, promptly the 6th lens L6 is at the surface (14) of picture side and the interval between the aperture diaphragm S.C is aperture diaphragm S and the interval of the 3rd optical system G3 between the surface (16) of the most close thing side of the 3rd optical system G3 at interval.Interval D is the surface of the 3rd optical system G3 in the most close picture side of the 3rd optical system G3, promptly the 11 lens L11 is on the surface (24) of picture side, with the 4th optical system G4 on the surface of the most close thing side, i.e. the interval of the 12 lens L12 between the surface (25) of thing side.E is the surface of the 4th optical system G4 in the most close picture side of the 4th optical system G4 at interval, promptly the 12 lens L12 is on the surface (26) of picture side, with the 5th optical system G5 at the most close thing side surface, promptly the 13 lens L13 between the surface (27) of thing side at interval.At interval F be the 5th optical system G5 on the surface of the most close picture side of the 5th optical system G5, i.e. surface (28), and the interval of optical filter between the surface of thing side.

In example 5, change focal length along with holding to dolly-out,ing dolly-back from wide-angle side, the focal distance f of zoom lens, F counts FNo, changes as follows respectively with half angle of view ω.

The focal distance f of zoom lens: 5.2-52.46

FNo (F number): 3.50-5.30

Half angle of view ω: 38.9-4.58

The character of each optical surface is shown in following table (table 9).

[table 9]

Surface number	R	D	Nd	vd
						1	44.95792	1.40000	2.00330	28.27
2	18.19123	5.55487	?	?
					3	∞	11.14295	1.92286	18.90
4	∞	11.14295	1.92286	18.90
					5	∞	0.10000	?	?
6	42.90852	4.64526	1.49700	81.54
					7	-35.50750	0.10000	?	?
8	40.99892	2.48547	1.60300	65.44
					9G	-306.68404	Variable (A)	?	?
10	-49.71461	0.80000	1.49700	81.54

11	11.26080	3.41169	?	?
					12	-9.34227	0.80000	1.49700	81.54
13	147.19076	1.23588	1.92286	18.90
					14G	-45.10958	Variable (B)	?	?
15G	∞ (aperture diaphragm)	Variable (C)	?	?
					16	8.79196	5.37097	1.48749	70.24
17	143.92676	0.85963	?	?
					18	14.53706	4.04747	1.49700	81.54
19	-6.95171	0.80000	1.78590	44.20
					20	17.97317	0.00000	?	?
21	17.97317	0.10194	?	?
					22	8.23791	0.80076	1.80400	46.57
23	5.79925	3.12722	1.58913	61.15
					24G	642.44812	Variable (D)	?	?
25	31.31937	1.76501	1.74320	49.29
					26G	11.95705	Variable (E)	?	?
27	-12.08678	3.50000	1.49700	81.54
					28G	-7.25904	Variable (F)	?	?
29	∞	0.30000	1.52300	58.00
					30	∞	0.10000	?	?
31	∞	0.50000	1.50000	64.00
					32	∞	?	?	?

In table 9, the tenth surface, the 11 surface, the 16 surface, the 17 surface, the 24 surface, the 26 surface, the 27 surface, and each of the 28 surface all be aspheric surface, and as follows for the parameter in each aspheric equation (18).

Aspheric surface: the tenth surface

K＝0.000000

A ₄＝1.449910E-04

A ₆＝1.720900E-06

A ₈＝-2.943860E-08A ₁₀＝3.977810E-10

Aspheric surface: the 11 surface

K＝0.000000

A ₄＝2.864370E-05

A ₆＝3.837370E-06

A ₈＝-1.006410E-07

A ₁₀＝3.355980E-09

Aspheric surface: the 16 surface

K＝0.000000

A ₄＝-5.069080E-06

A ₆＝1.438890E-08

A ₈＝-1.007550E-08

A ₁₀＝2.118830E-10

Aspheric surface: the 17 surface

K＝0.000000

A ₄＝-1.510860E-05

A ₆＝-1.211030E-06

A ₈＝-1.655590E-08

A ₁₀＝-1.507840E-10

Aspheric surface: the 24 surface

K＝0.000000

A ₄＝5.407590E-04

A ₆＝3.325480E-06

A ₈＝3.846210E-08

A ₁₀＝-9.465650E-10

Aspheric surface: the 26 surface

K＝0.000000

A ₄＝-6.584630E-05

A ₆＝5.465910E-06

A ₈＝4.646620E-08

A ₁₀＝6.650220E-09

Aspheric surface: the 27 surface

K＝0.000000

A ₄＝-3.624090E-04

A ₆＝3.250060E-05

A ₈＝6.245630E-07

A ₁₀＝-2.931100E-08

Aspheric surface: the 28 surface

K＝0.000000

A ₄＝3.902200E-04

A ₆＝1.416010E-05

A ₈＝6.486340E-07

A ₁₀＝-1.940390E-08

Variable interval A between the first lens combination G1 and the second lens combination G2, variable interval B between the second lens combination G2 and the aperture diaphragm S, variable interval C between aperture diaphragm S and the 3rd lens combination G3, variable interval D between the 3rd lens combination G3 and the 4th lens combination G4, variable interval E between the 4th lens combination G4 and the 5th lens combination G5, the variable interval F between the 5th lens combination G5 and the parallel-plate P is changing shown in following table (table 10) in the zoom process.

[table 10]

?	Wide-angle side	The middle focal length position	The end of dolly-out,ing dolly-back
				A?	0.70000?	14.37866?	19.74336?
B	23.13449	13.72404	0.70000
				C	11.75905	3.43101	0.55000
D	0.80663	4.86646	15.40681

E	2.81618	6.42695	8.06503
				F	3.99341	1.72324	0.70770

Value according to the parameter of the condition in the example 5 is as follows.

(the corresponding value of condition)

f1＝29.27

f2＝-11.50

fw＝5.2

ft＝52.46

Condition (10):

Condition (11):

Thereby, according to the numerical value of the above-mentioned condition (10) in the example 5 and (11) within described condition and range.

Figure 18 to 20 shows according to the spherical aberration in the zoom lens of example shown in Figure 17 5, astigmatism, the aberration curve of distortion and coma.Figure 18 is presented at the aberration curve of wide-angle side, and Figure 19 is presented at the aberration curve of middle focal length position, and Figure 20 is presented at the aberration curve of the end of dolly-out,ing dolly-back.In the spherical aberration curve, dotted line is represented sine condition, and in the astigmatism curve, solid line is represented the sagitta of arc as the plane, and dotted line represents that meridian is as the plane.

Aberration curve according to shown in Figure 18 to 20 it is found that, in the zoom lens of example shown in Figure 17 5, aberration is revised fully or controlled.

Because above structure, in the zoom lens of five lens combination, might suitably revise various aberrations and provide and have enough small sizes and high-performance and realize wide half angle of view that 38 degree are above and the zoom lens of counting FNo at the F of short burnt end below 3.5 simultaneously with Negative-Positive-Negative-negative-positive lens groups.

(example 6)

Figure 21 shows the structure of example 6 and from the sectional view of wide-angle side by a certain middle focal length position motion track of zoom to the process of the end zoom of dolly-out,ing dolly-back.

In Figure 17, zoom lens comprise the first lens combination G1 with positive refractive power, have the second lens combination G2 of negative refractive power, have the 3rd lens combination G3 of positive refractive power, have the 4th lens combination G4 of negative refractive power, and the 5th lens combination G5 with positive refractive power.Zoom lens further comprise the aperture diaphragm S between second lens combination and the 3rd lens combination.

In example 6, the first lens combination G1 and the 4th lens combination G4 do not move with stationary state in the zoom process.

Aperture diaphragm S is placed between the second lens combination G2 and the 3rd lens combination G3, and is configured to when changing the magnification of zoom lens towards the picture side shifting.

The 3rd lens combination G3 begins to be included in turn both sides from the thing side and has aspheric positive meniscus lens L7, by the positive lens L8 that all has convex surface in both sides with all have the cemented lens that the negative lens L9 of concave surface forms in both sides, and by diverging meniscus lens L10 with have the cemented lens that aspheric positive meniscus lens L11 forms as side.

In example 6, change focal length along with holding to dolly-out,ing dolly-back from wide-angle side, the focal distance f of zoom lens, F counts FNo, changes as follows respectively with half angle of view ω.

The focal distance f of zoom lens: 5.2-52.46mm

FNo (F number): 3.50-5.28

Half angle of view ω: 38.9-4.58

The character of each optical surface is shown in following table (table 11).

[table 11]

Surface number	R	D	Nd	vd
						1	45.44447	1.40000	2.00330	28.27
2	18.52295	5.58515	?	?
					3	∞	11.26822	1.92286	18.90
4	∞	11.26822	1.92286	18.90
					5	∞	0.10000	?	?
6	42.39953	4.73728	1.49700	81.54
					7	-35.60337	0.10000	?	?
8	38.18565	2.45785	1.60300	65.44
					9G	-2519.99255	Variable (A)	?	?
10	-50.86147	0.80000	1.49700	81.54
					11	10.98019	3.46346	?	?
12	-9.11946	0.80000	1.49700	81.54
					13	263.17588	1.22924	1.92286	18.90
14G	-40.13952	Variable (B)	?	?
					15G	0.00000	Variable (C)	?	?
16	8.80095	5.35627	1.48749	70.24
					17	188.97641	0.80757	?	?
18	14.99886	4.04394	1.49700	81.54
					19	-6.91983	0.80000	1.78590	44.20
20	18.21225	0.00000	?	?
					21	18.21225	0.19013	?	?
22	8.19502	0.80000	1.80400	46.57

23	5.82912	3.14711	1.58913	61.15
					24G	1294.77163	Variable (D)	?	?
25	34.63553	1.63261	1.74320	49.29
					26G	12.18727	Variable (E)	?	?
27	-13.24964	3.44828	1.49700	81.54
					28G	-7.54523	Variable (F)	?	?
29	∞	0.30000	1.52300	58.00
					30	∞	0.10000	?	?
31	∞	0.50000	1.50000	64.00
					32	∞	?	?	?

In table 11, the tenth surface, the 11 surface, the 16 surface, the 17 surface, the 24 surface, the 26 surface, the 27 surface, and each of the 28 surface all be aspheric surface, and as follows for the parameter in each aspheric equation (18).

Aspheric surface: the tenth surface

K＝0.00000E+00

₄＝1.439630E-04

A ₆＝1.538730E-06

A ₈＝-2.395260E-08

A ₁₀＝3.838090E-10

Aspheric surface: the 11 surface

K＝0.00000E+00

A ₄＝1.712430E-05

A ₆＝3.725930E-06

A ₈＝-1.083730E-07

A ₁₀＝3.775690E-09[0106]

Aspheric surface: the 16 surface

K＝0.00000E+00

A ₄＝-2.680710E-06

A ₆＝6.003040E-08

A ₈＝-1.010940E-08

A ₁₀＝1.992350E-10

Aspheric surface: the 17 surface

K＝0.00000E+00

₄-1.276190E-05

A ₆＝-1.201450E-06

A ₈＝-1.590580E-08

₁₀＝-2.483700E-10

Aspheric surface: the 24 surface

K＝0.00000E+00

A ₄＝5.412620E-04

A ₆＝3.506740E-06

A ₈＝3.839610E-08

A ₁₀＝-5.639540E-10

Aspheric surface: the 26 surface

K＝0.00000E+00

A ₄＝-6.846690E-05

A ₆＝5.731070E-06

A ₈＝-4.983040E-08

₁₀＝8.913470E-09

Aspheric surface: the 27 surface

K＝0.00000E+00

A ₄＝-3.541520E-04

A ₆＝3.170650E-05

A ₈＝5.801420E-07

A ₁₀＝-2.597480E-08

Aspheric surface: the 28 surface

K＝0.00000E+00

A ₄＝3.922150E-04

A ₆＝1.290590E-05

A ₈＝7.421130E-07

A ₁₀＝-2.059480E-08

Variable interval A between the first lens combination G1 and the second lens combination G2, variable interval B between the second lens combination G2 and the aperture diaphragm S, variable interval C between aperture diaphragm S and the 3rd lens combination G3, variable interval D between the 3rd lens combination G3 and the 4th lens combination G4, variable interval E between the 4th lens combination G4 and the 5th lens combination G5, the variable interval F between the 5th lens combination G5 and the parallel-plate P is changing shown in following table (table 12) in the zoom process.

[table 12]

?	Wide-angle side	The middle focal length position	The end of dolly-out,ing dolly-back
				A	0.70000	14.51205	19.90799
B	23.06270	13.65072	0.70000
				C	11.83274	3.41268	0.55000
D	0.89104	4.91104	15.32850
				E	3.19236	6.68222	8.37879
F	3.99544	1.72530	0.70975

As follows according to condition (10) in the example 6 to the value of the parameter of (11).

(the corresponding value of condition)

f1＝29.63

f2＝-11.4

fw＝5.2

ft＝52.46

Condition (10):

\frac{f 1}{\sqrt{fw \times ft}} = 1.79

Condition (11):

\frac{f 2}{\sqrt{fw \times ft}} = - 0.69

Thereby, according to the numerical value of the above-mentioned condition (10) in the example 6 and (11) within described condition and range.

Figure 22 to 24 shows according to the spherical aberration in the zoom lens of example shown in Figure 21 6, astigmatism, the aberration curve of distortion and coma.Figure 22 is presented at the aberration curve of wide-angle side, and Figure 23 is presented at the aberration curve of middle focal length position, and Figure 24 is presented at the aberration curve of the end of dolly-out,ing dolly-back.In the spherical aberration curve, dotted line is represented sine condition, and in the astigmatism curve, solid line is represented the sagitta of arc as the plane, and dotted line represents that meridian is as the plane.

Aberration curve according to shown in Figure 22 to 24 it is found that, in the zoom lens of example shown in Figure 21 6, aberration is revised fully or controlled.

Even realized 10.1 high variable power ratio, also can suitably revise aberration or the like.

About the third embodiment of the present invention, will be with reference to Figure 25,29,33 and 37 explain the concrete example according to the zoom lens of the 3rd embodiment.

In following example, shown in the example among Figure 25 7, zoom lens can comprise optical element, and it is placed in the picture side of the 6th lens combination G6 and forms with the parallel-plate form.For instance, optical element can be, such as the optics low pass filter, the optical filter of cutoff filter or the like, or the cover glass of the light receiving element of ccd sensor (seal glass) for example, being equivalent to transparent parallel-plate of above element or the like, it is called parallel-plate P.

(example 7)

Zoom lens comprise the first lens combination G1 with positive refractive power, the second lens combination G2 with negative refractive power has the 3rd lens combination G3 of positive refractive power, has the 4th lens combination G4 of negative refractive power, have the 5th lens combination G5 of positive refractive power, and the 6th lens combination G6 with negative refractive power.Zoom lens further comprise the aperture diaphragm S between second lens combination and the 3rd lens combination.

In example 7, the first lens combination G1, aperture diaphragm S, the 4th lens combination G4 and the 6th lens combination G6 do not move with stationary state in the zoom process.

The first lens combination G1 begins to comprise in turn to have at the convex surface of thing side with at the aspheric diverging meniscus lens L1 as side, prism PR, and two positive lens L2, L3 from the thing side.

The 3rd lens combination G3 begins to be included in turn that the thing side has aspheric surface and wherein than the positive meniscus lens L7 of another stronger convex surface towards the thing side from the thing side, by the positive lens L8 that all has convex surface in both sides with all have the cemented lens that the negative lens L9 of concave surface forms in both sides, and the positive lens L10 that all has convex surface in both sides.

The 6th lens combination G6 comprises positive meniscus lens L13, and it has in the aspheric surface of thing side and at the convex surface as side.

Shown in example 7, parallel-plate P is placed between the 6th lens combination G6 and the imaging surface I.Here; parallel-plate P is corresponding to optical element; for example; optical filter; for example be configured to the low pass filter of the corresponding spatial frequency of excess of limiting resolution of solid state image sensing device that amputation for example is placed in the CCD or the like of imaging surface I, perhaps be configured to protect the cover glass of image sensering device.

In example 7, change focal length along with holding to dolly-out,ing dolly-back from wide-angle side, the focal distance f of zoom lens, F counts FNo, changes as follows respectively with half angle of view ω.

The focal distance f of zoom lens: 5.2-35.0mm

FNo (F number): 3.41-5.91

Half angle of view ω: 38.9-6.8

The character of each optical surface is shown in following table (table 13).

[table 13]

Surface number	R	D	Nd	vd
						1	28.71520	0.70000	1.92286	18.90
2	10.60780	4.30000	?	?
					3	∞	8.00000	1.88300	40.76
4	∞	8.00000	1.88300	40.76
					5	∞	0.10000	?	?
6	71.87173	2.64346	1.51633	64.14
					7	-16.44232	0.10000	?	?
8	16.69061	1.85042	1.64000	60.08
					9	70.74017	Variable (A)	?	?
10	-18.06772	0.80000	2.00330	28.27
					11	13.70265	1.34310	?	?
12	-8.40441	0.80000	1.58913	61.15
					13	35.84699	1.37144	1.92286	18.90
14	-14.82566	Variable (B)	?	?
					15	∞ (aperture diaphragm)	Variable (C)	?	?
16	10.40018	2.55979	1.71700	47.93
					17	695.19360	4.38175	?	?

18	10.62658	3.03220	1.61800	63.33
					19	-8.68306	0.80000	1.90366	31.32
20	7.41539	0.47196	?	?
					21	7.95016	2.41954	1.48749	70.24
22	-28.32715	Variable (D)	?	?
					23	21.13305	0.80000	1.92286	18.90
24	10.38558	Variable (E)	?	?
					25	20.33524	3.00000	1.48749	70.24
26	-11.38514	Variable (F)	?	?
					27	-12.24222	0.80000	1.77250	49.60
28	-20.52607	0.37154	?	?
					29	∞	0.30000	1.52300	58.00
30	∞	0.10000	?	?
					31	∞	0.50000	1.50000	64.00
32	∞	?	?	?

In table 13, second surface, the 11 surface, the 16 surface, the 22 surface, the 24 surface, the 25 surface, and each of the 27 surface all be aspheric surface, and as follows for the parameter in each aspheric equation (18).

Aspheric surface: second surface

K＝0.00000E+00

A ₄＝-3.94417E-05

A ₆＝-4.97773E-07

A ₈＝4.02699E-09

A ₁₀＝-5.50352E-11

Aspheric surface: the 11 surface

K＝0.00000E+00

A ₄＝-9.62647E-05

A ₆＝5.51477E-07

A ₈＝-7.04684E-08

A ₁₀＝1.55863E-09

Aspheric surface: the 16 surface

K＝0.00000E+00

A ₄＝-4.74120E-05

A ₆＝1.07836E-07

A ₈＝-5.65417E-09

A ₁₀＝6.42398E-11

Aspheric surface: the 22 surface

K＝0.00000E+00

A ₄＝1.93283E-04

A ₆＝1.97214E-06

A ₈＝-2.90612E-07

A ₁₀＝5.81603E-09

Aspheric surface: the 24 surface

K＝0.00000E+00

A ₄＝3.10126E-04

A ₆＝3.13472E-06

A ₈＝8.92131E-07

A ₁₀＝-3.31098E-08

Aspheric surface: the 25 surface

K＝0.00000E+00

A ₄＝1.54388E-04

A ₆＝1.44637E-05

A ₈＝4.02382E-08

A ₁₀＝-9.54432E-09

Aspheric surface: the 27 surface

K＝0.00000E+00

A ₄＝5.46346E-04

A ₆＝-2.99878E-05

A ₈＝6.59274E-07

Variable interval A between the first lens combination G1 and the second lens combination G2, variable interval B between the second lens combination G2 and the aperture diaphragm S, variable interval C between aperture diaphragm S and the 3rd lens combination G3, variable interval D between the 3rd lens combination G3 and the 4th lens combination G4, variable interval E between the 4th lens combination G4 and the 5th lens combination G5, the variable interval F between the 5th lens combination G5 and the 6th lens combination G6 is changing shown in following table (table 14) in the zoom process.

[table 14]

?	Wide-angle side	The middle focal length position	The end of dolly-out,ing dolly-back
				A	1.174	6.241	10.769
B?	10.164?	5.098?	0.569?
				C	12.128	6.705	0.500
D	2.688	8.111	14.316
				E	2.410	5.032	5.150
F	3.228	0.606	0.488

As follows according to condition (12) in the example 7 to the value of the parameter of (17).

(the corresponding value of condition)

fw＝5.2

fT＝35

Y′＝4.2

Lr1＝13

Lr2＝69

Lg1＝25.7

fL1＝-18.57

T＝82

Tap＝41.3

Condition (12): fw/Y '=1.24

Condition (13): Lr1/Lr2=0.19

Condition (14): Lg1/fw=4.94

Condition (15): Lr2/ft=1.97

Condition (16): | fL1/fw|=3.57

Condition (17): Tap/T=0.5

Thereby, according to the numerical value of 7 above-mentioned condition (12) shown in Figure 25 and (17) as an example within described condition and range.

Figure 26 to 28 shows according to the spherical aberration in the zoom lens of example shown in Figure 25 7, astigmatism, the aberration curve of distortion and coma.Figure 26 is presented at the aberration curve of wide-angle side, and Figure 27 is presented at the aberration curve of middle focal length position, and Figure 28 is presented at the aberration curve of the end of dolly-out,ing dolly-back.In the spherical aberration curve, dotted line is represented sine condition, and in the astigmatism curve, solid line is represented the sagitta of arc as the plane, and dotted line represents that meridian is as the plane.

Aberration curve according to shown in Figure 26 to 28 it is found that, in the zoom lens of example shown in Figure 25 7, aberration is revised fully or controlled.

Because above structure, in the zoom lens of six lens combination, might suitably revise various aberrations and provide and have enough small sizes and high-performance and realize wide half angle of view that 38 degree are above and the zoom lens of counting FNo at the F of short burnt end below 3.5 simultaneously with Negative-Positive-Negative-negative-just-negative lens group.

According to example 7, described zoom lens can suitably be applied to have undersized body and high performance digital camera, therefore can provide to have the above wide half angle of view of 38 degree, and the high variable power ratio more than 5, and be used to have 5 * 10 ⁶To 10 ⁷The corresponding high performance zoom lens of the high resolving power of the image pick-up device of pixel.

(example 8)

Next, will explain zoom lens with reference to Figure 29 according to example 8.

Figure 29 be show the third embodiment of the present invention example 8 structure and from the sectional view of wide-angle side by the zoom motion track of a certain middle focal length position to the process of the end zoom of dolly-out,ing dolly-back.

Zoom lens comprise the first lens combination G1 with positive refractive power, the second lens combination G2 with negative refractive power has the 3rd lens combination G3 of positive refractive power, has the 4th lens combination G4 of negative refractive power, the 5th lens combination G5 with positive refractive power, and the 6th lens combination G6.Zoom lens further comprise the aperture diaphragm S between second lens combination and the 3rd lens combination.

In example 8, the first lens combination G1, aperture diaphragm S, the 4th lens combination G4 and the 6th lens combination G6 do not move with stationary state in the zoom process.

The 3rd lens combination G3 from the thing side begin to be included in turn both sides all have convex surface and wherein than another stronger convex surface towards the thing side and form aspheric positive meniscus lens L7, by the positive lens L8 that all has convex surface in both sides with all have the cemented lens that the negative lens L9 of concave surface forms in both sides, and the positive lens L10 that all has convex surface in both sides.

The 4th lens combination G4 is included in the thing side to have concave surface and is formed aspheric diverging meniscus lens L11 at the concave surface as side.

The 5th lens combination G5 is included in both sides all to have convex surface and wherein is formed aspheric positive lens L12 at the convex surface of thing side.

Shown in example 8, parallel-plate P is placed between the 6th lens combination G6 and the imaging surface I.Here; parallel-plate P is corresponding to optical element; for example; optical filter; for example be configured to the low pass filter of the corresponding spatial frequency of excess of limiting resolution of solid state image sensing device that amputation for example is placed in the CCD or the like of imaging surface I, perhaps be configured to protect the cover glass of image sensering device.

In example 8, change focal length along with holding to dolly-out,ing dolly-back from wide-angle side, the focal distance f of zoom lens, F counts FNo, changes as follows respectively with half angle of view ω.

The focal distance f of zoom lens: 5.23-35.0mm

FNo (F number): 3.33-5.99

Half angle of view ω: 38.9-6.8

The character of each optical surface is shown in following table (table 15).

[table 15]

Surface number	R	D	Nd	vd
						1	24.29547	0.70000	1.92286	18.90
2	9.75657	4.29950	?	?
					3	∞	8.00000	1.88300	40.76
4	∞	8.00000	1.88300	40.76
					5	∞	0.10000	?	?
6	200.55230	2.42139	1.51633	64.14
					7	-14.69376	0.10000	?	?
8	15.42392	2.12568	1.64000	60.08
					9	496.30189	Variable (A)	?	?
10	-20.83647	0.80000	2.00330	28.27
					11	11.05282	2.25137	?	?
12	-7.66956	0.80022	1.58913	61.15
					13	41.04884	1.22166	1.92286	18.90
14	-14.90628	Variable (B)	?	?
					15	∞ (aperture diaphragm)	Variable (C)	?	?
16	10.68546	2.65245	1.71700	47.93
					17	-926.63252	4.14070	?	?

18	11.96583	3.20000	1.61800	63.33
					19	-8.48903	0.80000	1.90366	31.32
20	8.29429	0.42399	?	?
					21	8.50827	2.57944	1.48749	70.24
22	-22.42544	Variable (D)	?	?
					23	-32.79524	0.80000	1.92286	18.90
24	36.06477	Variable (E)	?	?
					25	20.95609	3.00000	1.48749	70.24
26	-10.32363	Variable (F)	?	?
					27	-14.44984	0.80000	1.77250	49.60
28	-22.23806	0.11068	?	?
					29	∞	0.30000	1.52300	58.00
30	∞	0.10000	?	?
					31	∞	0.50000	1.50000	64.00
32	∞	?	?	?

In table 15, second surface, the 11 surface, the 16 surface, the 22 surface, the 24 surface, the 25 surface, and each of the 27 surface all be aspheric surface, and as follows for the parameter in each aspheric equation (18).

Aspheric surface: second surface

K＝0.00000E+00

A ₄＝-2.35463E-05

A ₆＝-7.98971E-07

A ₈＝8.43797E-09

A ₁₀＝-1.02004E-10

Aspheric surface: the 11 surface

K＝0.00000E+00

A ₄＝-1.22211E-04

A ₆＝-6.95451E-08

A ₈＝-2.75080E-08

A ₁₀＝-7.03527E-10

Aspheric surface: the 16 surface

K＝0.00000E+00

A ₄＝-4.53961E-05

A ₆＝1.71251E-07

A ₈＝-4.14722E-09

A ₁₀＝4.77677E-11

Aspheric surface: the 22 surface

K＝0.00000E+00

A ₄＝2.10011E-04

A ₆＝2.54274E-06

A ₈＝-1.70205E-07

A ₁₀＝2.68822E-09

Aspheric surface: the 24 surface

K＝0.00000E+00

A ₄＝3.15812E-04

A ₆＝2.37810E-06

A ₈＝6.93382E-07

A ₁₀＝-2.86333E-08

Aspheric surface: the 25 surface

K＝0.00000E+00

A ₄＝1.47734E-04

A ₆＝1.57338E-05

A ₈＝-1.57764E-07

A ₁₀＝-8.67412E-09

Aspheric surface: the 27 surface

K＝0.00000E+00

A ₄＝3.25997E-04

A ₆＝-5.01278E-05

A ₈＝1.45864E-06

Variable interval A between the first lens combination G1 and the second lens combination G2, variable interval B between the second lens combination G2 and the aperture diaphragm S, variable interval C between aperture diaphragm S and the 3rd lens combination G3, variable interval D between the 3rd lens combination G3 and the 4th lens combination G4, variable interval E between the 4th lens combination G4 and the 5th lens combination G5, the variable interval F between the 5th lens combination G5 and the 6th lens combination G6 is changing shown in following table (table 16) in the zoom process.

[table 16]

?	Wide-angle side	The middle focal length position	The end of dolly-out,ing dolly-back
				A	0.968	4.567	8.035
B	7.573	3.973	0.506
				C	12.508	6.489	0.500
D	5.119	11.138	17.127
				E	1.000	3.848	4.653
F	3.982	1.133	0.329

As follows according to condition (12) in the example 8 to the value of the parameter of (17).

(the corresponding value of condition)

fw＝5.2

fT＝35

Y′＝4.2

Lr1＝13

Lr2＝68.5

Lg1＝25.75

fL1＝-18.08

T＝81.5

Tap＝39.4

Condition (12): fw/Y '=1.24

Condition (13): Lr1/Lr2=0.19

Condition (14): Lg1/fw=4.95

Condition (15): Lr2/ft=1.96

Condition (16): | fL1/fw|=3.48

Condition (17): Tap/T=0.48

Correspondingly, according to the numerical value of 8 above-mentioned condition (12) shown in Figure 25 and (17) as an example within described condition and range.

Figure 30 to 32 shows according to the spherical aberration in the zoom lens of example shown in Figure 29 8, astigmatism, the aberration curve of distortion and coma.Figure 30 is presented at the aberration curve of wide-angle side, and Figure 31 is presented at the aberration curve of middle focal length position, and Figure 32 is presented at the aberration curve of the end of dolly-out,ing dolly-back.In the spherical aberration curve, dotted line is represented sine condition, and in the astigmatism curve, solid line is represented the sagitta of arc as the plane, and dotted line represents that meridian is as the plane.

Aberration curve according to shown in Figure 30 to 32 it is found that, in the zoom lens of example shown in Figure 29 8, aberration is revised fully or controlled.

According to above example 8, described zoom lens can suitably be applied to have undersized body and high performance digital camera, therefore can provide to have the above wide half angle of view of 38 degree, and the high variable power ratio more than 5, and be used to have 5 * 10 ⁶To 10 ⁷The corresponding high performance zoom lens of the high resolving power of the image pick-up device of pixel.

(example 9)

Next, will explain zoom lens with reference to Figure 33 according to example 9.

Figure 33 be show the third embodiment of the present invention example 9 structure and from the sectional view of wide-angle side by the zoom motion track of a certain middle focal length position to the process of the end zoom of dolly-out,ing dolly-back.

In example 9, the first lens combination G1, aperture diaphragm S, the 4th lens combination G4 and the 6th lens combination G6 do not move with stationary state in the zoom process.

The second lens combination G2 begins to have in turn from the thing side and has concave surface in both sides and wherein be formed aspheric negative lens L4 at the concave surface as side, and cemented lens, the negative lens L6 that wherein has the negative lens L5 of concave surface in both sides and have convex surface in both sides closely is attached to each other to form cemented lens.

The 3rd lens combination G3 from the thing side begin to be included in turn both sides all have convex surface and wherein than another stronger convex surface towards the thing side and form aspheric positive meniscus lens L7, by the positive lens L8 that all has convex surface in both sides with all have the cemented lens that the negative lens L9 of concave surface forms in both sides, and the positive lens L10 that has convex surface in both sides.

Shown in example 9, parallel-plate P is placed between the 6th lens combination G6 and the imaging surface I.Here; parallel-plate P is corresponding to optical element; for example; optical filter; for example be configured to the low pass filter of the corresponding spatial frequency of excess of limiting resolution of solid state image sensing device that amputation for example is placed in the CCD or the like of imaging surface I, perhaps be configured to protect the cover glass of image sensering device.

In example 9, change focal length along with holding to dolly-out,ing dolly-back from wide-angle side, the focal distance f of zoom lens, F counts FNo, changes as follows respectively with half angle of view ω.

The focal distance f of zoom lens: 5.2-35.0mm

FNo (F number): 3.39-5.80

Half angle of view ω: 38.9-6.8

The character of each optical surface is shown in following table (table 17).

[table 17]

Surface number	R	D	Nd	vd
						1	32.03396	0.69892	1.92286	18.90
2	10.76472	4.30259	?	?
					3	∞	8.00000	1.88300	40.76
4	∞	8.00000	1.88300	40.76
					5	∞	1.75841	?	?
6	115.94523	2.93171	1.51633	64.14
					7	-16.97664	0.09982	?	?
8	18.09178	1.82222	1.64000	60.08
					9	47.88622	Variable (A)	?	?
10	-18.80287	0.80040	2.00330	28.27
					11	17.51536	1.31481	?	?
12	-10.84426	0.80000	1.58913	61.15
					13	30.97094	2.75616	1.92286	18.90
14	-19.18998	Variable (B)	?	?
					15	∞ (aperture diaphragm)	Variable (C)	?	?
16	10.41903	2.52085	1.71700	47.93
					17	464.64637	4.42532	?	?
18	9.76213	2.75103	1.61800	63.33
					19	-9.30396	0.80000	1.90366	31.32

20	6.70577	0.55354	?	?
					21	7.65800	2.14226	1.48749	70.24
22	-40.70216	Variable (D)	?	?
					23	20.37002	0.79978	1.92286	18.90
24	9.00942	Variable (E)	?	?
					25	30.29651	2.99986	1.48749	70.24
26	-9.79500	Variable (F)	?	?
					27	-12.24779	0.80451	1.77250	49.60
28	-16.18715	0.10004	?	?
					29	∞	0.30000	1.52300	58.00
30	∞	0.10000	?	?
					31	∞	0.50000	1.50000	64.00
32	∞	?	?	?

In table 17, second surface, the 11 surface, the 16 surface, the 22 surface, the 24 surface, the 25 surface, and each of the 27 surface all be aspheric surface, and as follows for the parameter in each aspheric equation (18).

Aspheric surface: second surface

K＝0.00000E+00

A ₄＝-4.00372E-05

A ₆＝-5.29555E-07

A ₈＝5.09620E-09

A ₁₀＝-6.84250E-11

Aspheric surface: the 11 surface

K＝0.00000E+00

A ₄＝-4.18732E-05

A ₆＝8.80211E-07

A ₈＝-8.86591E-08

A ₁₀＝2.43942E-09

Aspheric surface: the 16 surface

K＝0.00000E+00

A ₄＝-4.08532E-05

A ₆＝5.83588E-08

A ₈＝-6.04882E-09

A ₁₀＝6.61854E-11

Aspheric surface: the 22 surface

K＝0.00000E+00

A ₄＝1.02687E-04

A ₆＝-5.99383E-07

A ₈＝-3.0147E-07

A ₁₀＝4.04148E-09

Aspheric surface: the 24 surface

K＝0.00000E+00

A ₄＝3.91184E-04

A ₆＝6.74675E-06

A ₈＝1.26729E-06

A1 ₀＝-5.59803E-08

Aspheric surface: the 25 surface

K＝0.00000E+00

A ₄＝1.84460E-04

A ₆＝1.50591E-05

A ₈＝2.64295E-07

A ₁₀＝-1.77378E-08

Aspheric surface: the 27 surface

K＝0.00000E+00

A ₄＝7.14836E-04

A ₆＝-5.38187E-05

A ₈＝1.24153E-06

Variable interval A between the first lens combination G1 and the second lens combination G2, variable interval B between the second lens combination G2 and the aperture diaphragm S, variable interval C between aperture diaphragm S and the 3rd lens combination G3, variable interval D between the 3rd lens combination G3 and the 4th lens combination G4, variable interval E between the 4th lens combination G4 and the 5th lens combination G5, the variable interval F between the 5th lens combination G5 and the 6th lens combination G6 is changing shown in following table (table 18) in the zoom process.

[table 18]

?	Wide-angle side	The middle focal length position	The end of dolly-out,ing dolly-back
				A	1.30888	8.95756	14.52007
B	13.77021	6.12143	0.55838
				C	11.76575	7.50884	0.50038
D	3.57353	7.83025	14.83876
				E	2.67224	5.71149	5.82142
F	3.55702	0.51762	0.40777

As follows according to condition (12) in the example 9 to the value of the parameter of (17).

(the corresponding value of condition)

fw＝5.2

fT＝35

Y′＝4.2

Lr1＝13

Lr2＝75.7

Lg1＝27.61

fL1＝-17.85

T＝88.7

Tap＝48.4

Condition (12): fw/Y '=1.24

Condition (13): Lr1/Lr2=0.17

Condition (14): Lg1/fw=5.31

Condition (15): Lr2/ft=2.16

Condition (16): | fL1/fw|=3.43

Condition (17): Tap/T=0.55

Thereby, according to the numerical value of 9 above-mentioned condition (12) shown in Figure 33 and (17) as an example within described condition and range.

Figure 34 to 36 shows according to the spherical aberration in the zoom lens of example shown in Figure 33 8, astigmatism, the aberration curve of distortion and coma.Figure 34 is presented at the aberration curve of wide-angle side, and Figure 35 is presented at the aberration curve of middle focal length position, and Figure 36 is presented at the aberration curve of the end of dolly-out,ing dolly-back.In the spherical aberration curve, dotted line is represented sine condition, and in the astigmatism curve, solid line is represented the sagitta of arc as the plane, and dotted line represents that meridian is as the plane.

Aberration curve according to shown in Figure 34 to 36 it is found that, in the zoom lens of example shown in Figure 33 9, aberration is revised fully or controlled.

Because above structure, in the zoom lens of six lens combination, might suitably revise various aberrations and provide and have enough small sizes and high-performance and realize wide half angle of view that 38 degree are above and the zoom lens of counting FNo at the F of short burnt end below 3.4 simultaneously with Negative-Positive-Negative-negative-just-negative lens group.

(example 10)

Next, will explain zoom lens with reference to Figure 37 according to the example 10 of second embodiment.

Figure 37 is that demonstration is according to the structure of the zoom lens of the example 10 of second embodiment and the sectional view of the zoom motion track when holding the magnification that change zoom lens by the middle focal length position to dolly-out,ing dolly-back from wide-angle side.

Zoom lens begin to comprise in turn the first lens combination G1 with positive refractive power from the thing side, the second lens combination G2 with negative refractive power, the 3rd lens combination G3 with positive refractive power, the 4th lens combination G4 with negative refractive power, have the 5th lens combination G5 of positive refractive power, and the 6th lens combination G6 with negative refractive power.Zoom lens further comprise the aperture diaphragm S between second lens combination and the 3rd lens combination.

In example 10, the first lens combination G1, aperture diaphragm S, the 4th lens combination G4 and the 6th lens combination G6 do not move with stationary state in the zoom process.

The second lens combination G2 begins to have in turn from the thing side and has concave surface in both sides and wherein be formed aspheric negative lens L4 at the concave surface as side, and cemented lens, the negative lens 15L6 that wherein has the negative lens L5 of concave surface in both sides and have convex surface in both sides closely is attached to each other to form cemented lens.

The 4th lens combination G4 is included in both sides all to have concave surface and is formed aspheric diverging meniscus lens L11 at the concave surface as side.

Shown in example 10, parallel-plate P is placed between the 6th lens combination G6 and the imaging surface I.Here; parallel-plate P is corresponding to optical element; for example; optical filter; for example be configured to the low pass filter of the corresponding spatial frequency of excess of resolution limiting of solid state image sensing device that amputation for example is placed in the CCD or the like of imaging surface I, perhaps be configured to protect the cover glass of image sensering device.

In example 10, change focal length along with holding to dolly-out,ing dolly-back from wide-angle side, the focal distance f of zoom lens, F counts FNo, changes as follows respectively with half angle of view ω.

The focal distance f of zoom lens: 5.2-35.0mm

FNo (F number): 3.57-5.85

Half angle of view ω: 38.9-6.8

The character of each optical surface is shown in following table (table 19).

[table 19]

Surface number	R	D	Nd	vd
						1	28.31032	0.70000	1.92286	18.90
2	11.25635	4.30000	?	?
					3	∞	8.00000	1.88300	40.76
4	∞	8.00000	1.88300	40.76
					5	∞	0.10000	?	?
6	85.85108	2.71603	1.51633	64.14
					7	-17.03452	0.10000	?	?
8	16.20458	2.25308	1.64000	60.08
					9	910.38236	Variable (A)	?	?
10	-31.86938	0.80000	2.00330	28.27
					11	9.20213	2.94713	?	?
12	-7.46158	1.06977	1.58913	61.15
					13	35.36813	1.23606	1.92286	18.90
14	-16.73301	Variable (B)	?	?
					15	∞ (aperture diaphragm)	Variable (C)	?	?
16	10.71389	2.84516	1.71700	47.93
					17	-3109.41267	4.32612	?	?
18	11.54987	3.02339	1.61800	63.33
					19	-8.68996	0.80000	1.90366	31.32

20	8.58883	0.44713	?	?
					21	8.82218	2.40401	1.48749	70.24
22	-19.30681	Variable (D)	?	?
					23	-104.23069	0.80000	1.92286	18.90
24	16.11154	Variable (E)	?	?
					25	21.61061	3.00000	1.48749	70.24
26	-10.11978	Variable (F)	?	?
					27	-10.32054	0.80000	1.77250	49.60
28	-12.64506	0.10000	?	?
					29	∞	0.30000	1.52300	58.00
30	∞	0.10000	?	?
					31	∞	0.50000	1.50000	64.00
32	∞	?	?	?

In table 19, second surface, the 11 surface, the 16 surface, the 22 surface, the 24 surface, the 25 surface, and each of the 27 surface all be aspheric surface, and as follows for the parameter in each aspheric equation (18).

Aspheric surface: second surface

K＝0.00000E+00

A ₄＝-2.71728E-06

A ₆＝-3.58900E-07

A ₈＝1.70392E-09

A ₁₀＝4.11931E-13

Aspheric surface: the 11 surface

K＝0.00000E+00

A ₄＝-1.24369E-04

A ₆＝1.17040E-06

A ₈＝-9.36061E-08

A ₁₀＝-1.94537E-09

Aspheric surface: the 16 surface

K＝0.00000E+00

A ₄＝-5.03986E-05

A ₆＝1.88819E-07

A ₈＝-4.04258E-09

A ₁₀＝4.05202E-11

Aspheric surface: the 22 surface

K＝0.00000E+00

A ₄＝2.35721E-04

A ₆＝1.56156E-06

A ₈＝-1.45635E-07

A ₁₀＝2.75915E-09

Aspheric surface: the 24 surface

K＝0.00000E+00

A ₄＝3.77794E-04

A ₆＝1.16807E-05

A ₈＝6.58942E-07

A ₁₀＝-4.47280E-08

Aspheric surface: the 25 surface

K＝0.00000E+00

A ₄＝1.70399E-04

A ₆＝2.68367E-05

A ₈＝1.09834E-08

A ₁₀＝-3.07464E-08

Aspheric surface: the 27 surface

K＝0.00000E+00

A ₄＝3.59460E-04

A ₆＝-5.08998E-05

A ₈＝1.62131E-06

Variable interval A between the first lens combination G1 and the second lens combination G2, variable interval B between the second lens combination G2 and the aperture diaphragm S, variable interval C between aperture diaphragm S and the 3rd lens combination G3, variable interval D between the 3rd lens combination G3 and the 4th lens combination G4, variable interval E between the 4th lens combination G4 and the 5th lens combination G5, the variable interval F between the 5th lens combination G5 and the 6th lens combination G6 is changing shown in following table (table 20) in the zoom process.

[table 20]

?	Wide-angle side	The middle focal length position	The end of dolly-out,ing dolly-back
				A	0.889	5.001	8.828
B	8.566	4.454	0.628
				C	11.188	5.755	0.500
D	5.424	10.858	16.113
				E	1.000	3.351	3.485
F	3.167	0.816	0.682

As follows according to condition (12) in the example 10 to the value of the parameter of (17).

(the corresponding value of condition)

fw＝5.2

fT＝35

Y′＝4.2

Lr1＝13

Lr2＝69.5

Lg1＝26.17

fL1＝-20.65

T＝82.5

Tap＝41.7

Condition (12): fw/Y '=1.24

Condition (13): Lr1/Lr2=0.19

Condition (14): Lg1/fw=5.03

Condition (15): Lr2/ft=1.99

Condition (16): | fL1/fw|=3.97

Condition (17): Tap/T=0.51

Thereby, according to the numerical value of 10 above-mentioned condition (12) shown in Figure 37 and (17) as an example within described condition and range.

Figure 38 to 40 shows according to the spherical aberration in the zoom lens of example shown in Figure 37 10, astigmatism, the aberration curve of distortion and coma.Figure 38 is presented at the aberration curve of wide-angle side, and Figure 39 is presented at the aberration curve of middle focal length position, and Figure 40 is presented at the aberration curve of the end of dolly-out,ing dolly-back.In the spherical aberration curve, dotted line is represented sine condition, and in the astigmatism curve, solid line is represented the sagitta of arc as the plane, and dotted line represents that meridian is as the plane.

Aberration curve according to shown in Figure 38 to 40 it is found that, in the zoom lens of example shown in Figure 37 10, aberration is revised fully or controlled.

Because above structure, in the zoom lens of six lens combination, might suitably revise various aberrations and provide and have enough small sizes and high-performance and realize above wide half angle of view of 38 degree and the zoom lens of counting FNo at the F of short burnt end below 35 simultaneously with Negative-Positive-Negative-negative-just-negative lens group.

According to this example, described zoom lens can suitably be applied to have undersized body and high performance digital camera, therefore can provide to have the above wide half angle of view of 38 degree, and the high variable power ratio more than 5, and be used to have 5 * 10 ⁶To 10 ⁷The corresponding high performance zoom lens of the high resolving power of the image pick-up device of pixel.

[the 4th embodiment]

Next, for example use according to an embodiment of the invention zoom lens as the camera of imaging optical system with describing in detail with reference to the accompanying drawings, the imaging device of personal digital assistant or the like.

Figure 41 A is to the stereographic map of the external structure of the 41C camera that to be diagram constitute by the imaging optical system that adopts according to any one zoom lens of above-mentioned example 1 to 10 of the present invention.Within these, Figure 41 A is from front side (object side with frame form's diagram, that is to say, the side of the luminous main body) stereographic map of the outward appearance of collapse (collapse) state (that is to say that wherein the meniscus camera lens unit is by the state of collapse) of the camera of watching.Figure 41 B is that diagram is watched from the front side, the stereographic map of the part outward appearance of state in the use of camera (that is to say, wherein the state of meniscus camera lens unit stretching, extension).Figure 41 C is the stereographic map with the outward appearance of frame form's diagram camera that (cameraman's side) watches from the back side.In addition, Figure 42 is the block scheme of the functional configuration of graphic camera among diagram Figure 41.

Figure 41 A, graphic camera 120 comprises meniscus camera lens 121 among 41B and the 41C, view finder 122, flashlamp 123, shutter release button 124, zoom lever 125, liquid crystal display (LCD) monitor 126, action button unit 127, power switch 130, accumulator groove 129 and communication draw-in groove 128 or the like.

In addition, as graphic in Figure 42, the functional block of camera 120 comprises CPU (central processing unit) (CPU) 131, image processor 132, signal processor 133, semiconductor memory 134, LCD monitor 126, communication card 135 or the like, and light receiving element 136.

At first, general structure at Figure 41 A graphic camera in 41C and Figure 42 is described.

Comprise meniscus camera lens 121 and not graphic light receiving element (area transducer at Figure 41 A graphic camera in the 41C, that is to say, Shuo Ming light receiving element 136 subsequently), the image by the photograph target that wherein forms by meniscus camera lens 121 is constituted as by light receiving element 136 and reads.

In Figure 42, handle (signal processor 133 is by CPU (central processing unit) 131 controls) and change numerical information into by signal processor 133 from the output of light receiving element 136 (area transducer).By signal processor 133 digitized image informations in image processor 132 by Flame Image Process (image processor 132 by central processing unit 131 control).Image information is recorded in 134 li of semiconductor memories then.Image in the photograph process or the image that is recorded in 134 li of semiconductor memories may be displayed in the LCD monitor 126.In addition, the image that is recorded in 134 li of semiconductor memories can use communication card 135 or the like to send to the outside.

When camera is carried in pocket or the like, meniscus camera lens 121 be as in Figure 41 A graphic collapse state.When the user passed through operating power switch 130 power-on, lens drum was as graphic stretching, extension the in Figure 41 B.This moment, each lens combination of the zoom lens in the lens drum all by, for example, be placed in wide-angle side.The layout of each lens combination of zoom lens is changed by operation zoom lever 125, and can carry out changing to the magnification of the end of dolly-out,ing dolly-back.This moment, view finder 122 also changes by the visual angle of being coupled to meniscus camera lens 121, changes magnification.

By press shutter release button 124 half, focus on.Can the scioptics element move or light receiving element 136 focuses on respect to the relative motion of meniscus camera lens optical system.When shutter release button 124 is further pressed, take a picture and carry out above-mentioned processing thereafter.

Action button 127 is used for being displayed on LCD monitor 126 or using communication card 135 or the like the operation when send the outside when the image that is recorded in 134 li of semiconductor memories.Semiconductor memory 134 and communication card 135 or the like are inserted in groove special use or general (at this, the memory card slot 129 and the draw-in groove 128 of communicating by letter) that is used to use respectively.

In addition, in above-mentioned camera, described zoom lens can be used as the meniscus camera lens optical system.So, can realize using the camera of undersized and high image quality of light receiving element 136 of the grade of 500 ten thousand to 1,000 ten thousand pixels.

Next, illustrate and adopt imaging device of the present invention, at the more detailed structure of Figure 41 A graphic camera in 41C and Figure 42.Yet though following explanation is to make for camera, issue in recent years finishes the removable information terminal device of the group photo so-called PDA (personal digital assistant) of camera function or cell phone or the like.Removable information terminal device although it is so has slightly different outward appearance, but they can in conjunction with in fact with the function and the structure that are equal at Figure 41 A graphic camera in 41C and Figure 42, and in so removable information terminal device, can adopt imaging optical system according to imaging device of the present invention.

Camera according to the present invention comprises meniscus camera lens 121 as the meniscus camera lens optical system, and comprises the area transducer of light receiving element 136 (Figure 42) as CCD (charge-coupled device (CCD)) image pick-up device or the like.The image of the luminous main body that is formed by meniscus camera lens 121 (imaging optical system) is configured to be read by light receiving element 136.The imaging optical system according to imaging device of the present invention of explanation is used as meniscus camera lens 121 among Figure 17 or the like.Particularly, as mentioned above, be used to constitute lens unit as the lens of the optical element that constitutes meniscus camera lens optical system (zoom lens).This lens unit have mechanism of each lens of clamping or the like so that at least each lens combination all pass through to operate removable.The meniscus camera lens of incorporating into according to camera of the present invention 121 is merged in the form of this lens unit usually.

According to embodiments of the invention, can provide wherein can obtain fully little body and high variable power than and realize the zoom lens at high-performance and wide visual angle simultaneously, imaging device, and personal digital assistant.

Though according to one exemplary embodiment the present invention has been described, it is not restricted to this.It should be understood that if do not break away from the scope of the present invention that limits as following claim, can in the embodiment of explanation, make variation by the person skilled in the art.

Claims

1. zoom lens is characterized in that, comprising:

First optical system with positive focal length, described first optical system comprises deflecting optical element;

Second optical system with negative focal length;

The 3rd optical system with positive focal length;

The 4th optical system with negative focal length;

The 5th optical system with positive focal length, described first to the 5th optical system is arranged successively by order from the object side to image side; And

Be arranged on the aperture diaphragm of the thing side of described the 3rd optical system,

Wherein when holding long burnt end to change the magnification of described zoom lens from short Jiao, interval between described first optical system and described second optical system increases, interval between described second optical system and the described aperture diaphragm reduces, interval between described aperture diaphragm and described the 3rd optical system reduces, interval between described the 3rd optical system and described the 4th optical system increases, and the interval between described the 4th optical system and described the 5th optical system increases; And

Wherein meet the following conditions:

0.5＜(T23w/Y’)/(ft/fw)＜1.0

Wherein T23w is the interval between described short burnt described second optical system of end and described the 3rd optical system, Y ' is the maximum image height degree of described zoom lens, ft is the focal lengths of described zoom lens at described long burnt end, and fw is the focal lengths of described zoom lens at described short burnt end, and

Described the 4th optical system is when keeping static from described short burnt end when described long burnt end changes the described magnification of described zoom lens,

The maximum diameter of hole Dt that holds described aperture diaphragm described long Jiao is greater than the maximum diameter of hole Dw at the described aperture diaphragm of described short burnt end.

2. zoom lens as claimed in claim 1 is characterized in that, meet the following conditions:

0.2＜Ts3w/T2sw＜1.5

Wherein Ts3w is the interval between described short burnt described aperture diaphragm of end and described the 3rd optical system, and T2sw is the interval between described short burnt described second optical system of end and described aperture diaphragm.

3. zoom lens as claimed in claim 1 is characterized in that, meet the following conditions:

2.0＞Dt/Dw＞1.1

Wherein Dt is in the maximum diameter of hole of the described aperture diaphragm of described long burnt end, and Dw is the maximum diameter of hole at the described aperture diaphragm of described short burnt end.

4. zoom lens as claimed in claim 1 is characterized in that, meet the following conditions:

-3.0＜f2/Y’＜-1.2

2.0＜f3/Y’＜4.0

Wherein f2 is that the focal length and the described f3 of described second optical system are the focal length of the 3rd optical system.

5. zoom lens as claimed in claim 1 is characterized in that, meet the following conditions:

3.5＞b2t/b2w＞2.0

3.0＞b3t/b3w＞1.5

Wherein b2t is the lateral magnification in described second optical system of described long burnt end, b2w is the lateral magnification in described second optical system of described short burnt end, b3t is the lateral magnification in described the 3rd optical system of described long burnt end, and b3w is the lateral magnification in described the 3rd optical system of described short burnt end.

6. zoom lens as claimed in claim 1 is characterized in that, meet the following conditions:

1.0＞(b3t/b3w)/(b2t/b2w)＞0.5

7. an imaging device is characterized in that, described imaging device comprises zoom lens as claimed in claim 1.

8. imaging device as claimed in claim 7 is characterized in that, comprises that further being used for the image transitions by described zoom lens imaging is the device of numerical information.

9. a personal digital assistant is characterized in that, described personal digital assistant comprises zoom lens as claimed in claim 1.