JP2008107559A - Zoom lens and electronic imaging apparatus using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a zoom lens which is easily made small in size when it is collapsed, and easily secures an angle of view and optical performance. <P>SOLUTION: The zoom lens has a first positive group G1, a second negative group G2 and a third positive group G3. When varying power from a wide angle end to a telephoto end, space between the first group G1 and the second group G2, and space between the second group G2 and the third group G3 are changed so that the space between the first group G1 and the second group G2 may be wider at the telephoto end than at the wide angle end and the space between the second group G2 and the third group G3 may be narrower at the telephoto end than at the wide angle end. The first group G1 includes a positive lens and comprises lenses whose total number is two or less. The second group G2 comprises three lenses, that is, an object-side negative lens, a positive lens and an image-side negative lens in order from an object side, wherein both the object-side surface and the image-side surface of the object-side negative lens are concave, and the image-side surface of the positive lens is convex to the image side, and the image-side surface of the positive lens is convex to the image-side, and the absolute value of the radius of curvature of the image-side surface of the positive lens is smaller than the absolute value of the radius of curvature of the object-side surface thereof. The object-side negative lens and the positive lens in the second group G2 are arranged while holding space on an optical axis in between. The zoom lens satisfies conditions (1) and (2). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a zoom lens and an electronic imaging device using the zoom lens, and more particularly to a zoom lens suitable for an electronic imaging device such as a video camera or a digital camera that has been downsized.

  In recent years, digital cameras that shoot subjects using electronic image pickup devices such as CCDs and CMOSs instead of silver salt film cameras have become mainstream. Furthermore, it has come to have a number of categories in a wide range from high-functional types for business use to compact popular types.

  Users of popular digital cameras have a desire to enjoy shooting in various scenes anytime and anywhere. For this reason, a digital camera of a small size, in particular, a type in which the size in the thickness direction is thin, which can be easily carried in a pocket of a clothes or a bag, is easy to carry.

  On the other hand, a zoom ratio of a compact type digital camera is generally about 3 times, but a camera with a higher zoom ratio than the conventional one is demanded.

  As a zoom lens that can easily maintain a relatively high zoom ratio, there is a zoom lens having a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a positive refractive power from the object side. Are known.

On the other hand, the size of the camera in the thickness direction is mainly determined by the size of the lens barrel, so it is effective to make the lens barrel thinner in order to achieve a thinner camera. .

  Recently, a so-called collapsible lens barrel is generally used in which the lens barrel protrudes from the camera body and is housed in the camera body when being carried. Therefore, there is a need for a zoom lens that takes into account the reduction in thickness of the lens barrel when retracted.

In the prior arts of Patent Documents 1 to 6 below, the first lens group is composed of two or three lenses, and the second lens group is symmetrical from the object side in order of a negative lens, a positive lens, and a negative lens. There has been disclosed a zoom lens in which aberration correction and miniaturization of the second lens group are performed by using a simple power arrangement.
JP-A-2005-242116 JP-A-2005-326743 JP 2006-78979 A JP 2005-32684 A JP-A-2005-148420 JP-A-2005-242116

  However, the above-described conventional techniques have the following problems.

  In the above-described conventional technology, the most object side surface of the second lens group has a convex surface facing the object side. In such a configuration, the thickness of the second lens group itself is increased, and interference is likely to occur even if the first lens group is brought closer to the second lens group, so that the size of the retracted lens can be reduced and the zoom ratio can be increased. It will be disadvantageous.

Further, since the first lens group cannot be brought close to the second lens group on the wide angle side, there is a problem that the radial direction of the first lens group becomes large in order to secure the angle of view. The first lens group having three lenses is disadvantageous for further miniaturization.
The present invention has been made in view of such problems of the prior art, and its object is to reduce the number of lenses in the first lens group and the second lens group and to reduce the thickness of the second lens group. It is an object of the present invention to provide a zoom lens that facilitates ensuring optical performance while facilitating the distance from the first lens group to be close, miniaturizing, and securing a zoom ratio.
It is another object of the present invention to provide an electronic imaging device that is easy to miniaturize by providing such a zoom lens.
Furthermore, it is an object of the present invention to provide a zoom lens and an electronic image pickup apparatus using the zoom lens that are easier to reduce in size, ensure aberration performance, and ensure a zoom ratio by devising each lens group of the zoom lens. It is.

The zoom lens of the present invention that achieves the above object has, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a positive refractive power,
During zooming from the wide-angle end to the telephoto end, the distance between the first lens group and the second lens group and the distance between the second lens group and the third lens group are changed,
The distance between the first lens group and the second lens group is wider at the telephoto end than at the wide angle end,
The distance between the second lens group and the third lens group is narrower at the telephoto end than at the wide-angle end,
The first lens group includes a positive lens, and the total number of lenses is two or less.
The second lens group is composed of three lenses in order from the object side: an object-side negative lens, a positive lens, and an image-side negative lens;
The object side surface and the image side surface of the object side negative lens are both concave surfaces,
The image side surface of the positive lens is a convex surface on the image side, and the curvature radius absolute value of the image side surface is smaller than the curvature radius absolute value of the object side surface,
The object side negative lens and the positive lens in the second lens group are arranged with an air gap on the optical axis,
The following conditional expression is satisfied.

0.0 <f ₂ / R _2n1f <0.4 (1)
−1.6 <SF _2air <−0.5 (2)
Where R _2n1f is the paraxial radius of curvature of the object side surface of the object side negative lens in the second lens group,
f ₂ is the focal length of the second lens group,
SF _2air = (R _2n1r + R _2pf ) / (R _2n1r −R _2pf )
R _2n1r is the paraxial radius of curvature of the image side surface of the object side negative lens of the second lens group,
R _2pf is the paraxial radius of curvature of the object side surface of the positive lens in the second lens group,
It is.

  Hereinafter, the reason and effect | action which took such a structure are demonstrated.

  In the present invention, in order from the object side, a first lens unit having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a positive refractive power are provided, and zooming from the wide angle end to the telephoto end is performed. Further, the distance between the first lens group and the second lens group and the distance between the second lens group and the third lens group are changed, and the distance between the first lens group and the second lens group is A configuration is adopted in which zooming is performed by widening at the telephoto end with respect to the wide-angle end and narrowing the distance between the second lens group and the third lens group at the telephoto end with respect to the wide-angle end.

  By adopting such a configuration, it is possible to efficiently share the burden of zooming between the second lens group and the third lens group, and it is easy to suppress aberration fluctuation during zooming while ensuring a zoom ratio. Become.

  By configuring the first lens group with as few as two lenses and the second lens group with as few as three lenses, it is easy to suppress the thickness of the zoom lens when retracted. In addition, the distance from the most object side surface of the first lens group to the entrance pupil at the wide-angle end can be easily reduced, and the size of the zoom lens in the radial direction can be easily reduced.

  In the present invention, two negative lenses are arranged in the second lens group to share the negative power of the second lens group so that aberration can be easily suppressed, and the negative lens, the positive lens, and the negative lens are sequentially arranged from the object side. By arranging them in a line, the symmetry of the lens configuration is improved, and the aberration can be corrected efficiently in the second lens group.

  In the present invention, the object side surface and the image side surface of the object side negative lens of the second lens group are both concave.

  By adopting such a shape, it is easy to secure the negative power of the second lens group while suppressing the occurrence of spherical aberration at the telephoto end, and it becomes easy to suppress the thickness of the second lens group on the optical axis. .

  Then, the image side surface of the positive lens of the second lens group is convex to the image side, and the absolute value of the curvature radius of the image side surface is made smaller than the absolute value of the curvature radius of the object side surface. The object-side negative lens and the positive lens were arranged on the optical axis with an air gap therebetween. With this configuration, it is advantageous to secure a zoom ratio by making the principal point of the second lens group the object, while ensuring the positive refractive power of the only positive lens in the second lens group. In addition, it becomes easy to balance aberration between the object-side biconcave negative lens and the image-side negative lens.

  Furthermore, it is preferable that the following conditional expression is satisfied.

0.0 <f ₂ / R _2n1f <0.4 (1)
−1.6 <SF _2air <−0.5 (2)
Where R _2n1f is the paraxial radius of curvature of the object side surface of the object side negative lens in the second lens group,
f ₂ is the focal length of the second lens group,
SF _2air = (R _2n1r + R _2pf ) / (R _2n1r −R _2pf )
R _2n1r is the paraxial radius of curvature of the image side surface of the object side negative lens of the second lens group,
R _2pf is the paraxial radius of curvature of the object side surface of the positive lens in the second lens group,
It is.

  In the present invention, the object side surface of the negative lens closest to the object side in the second lens group is concave on the object side. As a result, the principal point position of the second lens group becomes closer to the first lens group, and the overall length can be shortened, or the magnification of the second lens group can be increased to increase the zoom ratio. At this time, conditional expression (1) should be satisfied.

  By avoiding falling below the lower limit 0.0 of conditional expression (1), it becomes easier to obtain the effect of bringing the principal point position of the second lens group closer to the first lens group, and the overall length is reduced and the zoom ratio is increased. Is advantageous.

  By suppressing the curvature of this surface appropriately so as not to exceed the upper limit of 0.4, it becomes easy to suppress excessive correction of curvature of field, particularly at the wide angle end.

  If conditional expression (1) is satisfied, the negative power of the second lens group tends to increase. Therefore, in order to maintain the negative power of the second lens group within an appropriate range and easily maintain the aberration state, it is preferable to satisfy the conditional expression (2).

  It is preferable not to exceed the upper limit of −0.5 of conditional expression (2) so as to moderately suppress the negative power of the second lens group and suppress the occurrence of various aberrations. In particular, it becomes easy to suppress excessive correction of curvature of field.

  The curvature of the object side of the positive lens is suppressed so that it does not fall below the lower limit of −1.6, the difference in refraction angle between the upper and lower rays of off-axis rays is reduced, and coma occurs at the telephoto end. It is preferable to suppress the amount of aberration in the positive lens with respect to the amount of aberration generated in the negative lens by appropriately suppressing the amount.

  Regarding conditional expression (1), the following is more preferable.

0.005 <R _2n1f / f ₂ <0.3 (1) ′
It is more preferable that the following is satisfied.

0.01 <R _2n1f / f ₂ <0.2 (1) ''
Regarding conditional expression (2), the following is more preferable.

−1.4 <SF _2air <−0.7 (2) ′
It is more preferable that the following is satisfied.

-1.2 <SF _2air <-0.9 (2) ''
Furthermore, it is preferable that the number of lenses on the image side with respect to the third lens group of the zoom lens be three or less.

  This is advantageous in reducing the thickness of the lens when it is moved down and simplifying the configuration of the zoom lens.

  If the zoom lens is a three-group zoom lens, the mechanism for moving the lens can be simplified.

  If the zoom lens is a four-group zoom lens and the fourth lens group has a positive refractive power, it is preferable to ensure the function of moving the exit pupil away from the fourth lens group. Furthermore, if the fourth lens group is configured to move during focusing, it is easy to suppress changes in the angle of view during focusing.

  If the zoom lens is a four-group zoom lens and the fourth lens group is a single positive lens, the function of moving the exit pupil away can be secured, which is preferable for downsizing when the lens is retracted.

  If the zoom lens is a 5-group zoom lens, the fourth lens group has negative refracting power and the fifth lens group has positive refracting power, the power arrangement of the entire zoom lens group can be made symmetrical, and astigmatism during zooming can be achieved. This is preferable because it is easy to suppress fluctuations.

  In each of the above-described inventions, the following conditional expressions are satisfied on both sides of the space sandwiched between the first lens group and the second lens group, so that the miniaturization and the aberration balance are improved. It becomes easy.

0.00 <(1 / R _2n1f −1 / R _1r ) · f ₂ <0.40 (3)
Where R _1r is the paraxial radius of curvature of the image side surface of the most image side lens in the first lens group,
It is.

  This conditional expression defines the difference in curvature between the lens surfaces before and after the space between the first lens group and the second lens in order to easily balance the aberration from the wide-angle end to the telephoto end.

  By avoiding falling below the lower limit of 0.00, it becomes easier to bring the first lens unit and the second lens unit closer to the off-axis lens at the wide-angle end, ensuring a difference in curvature between both lens surfaces, and at the wide-angle end. This is advantageous for correcting curvature of field.

  By making sure that the upper limit of 0.40 is not exceeded, it is advantageous for securing the power of the first lens group, and it is advantageous for correcting spherical aberration at the telephoto end.

Furthermore, 0.03 <(1 / R _2n1 −1 / R _1r ) · f ₂ <0.30 (3) ′
Furthermore, 0.07 <(1 / R _2n1 -1 / R _1r ) · f ₂ <0.20 (3) ''
It is more preferable.

  Only the lower limit value or only the upper limit value of the conditional expression described above may be limited.

  The same applies to the following conditional expressions.

    It is preferable that conditional expressions (4) and (5) are satisfied for the positive lens in the second lens group. This is a conditional expression regarding the refractive index and the Abbe number of the positive lens of the second lens group.

1.84 <n _d2p <2.20 (4)
13.0 <ν _d2p <30.0 (5)
Where n _d2p is the refractive index of the positive lens in the second lens group with respect to the d-line,
ν _d2p is the Abbe number of the positive lens in the second lens group,
It is.

  By avoiding exceeding the upper limit of 2.20 of conditional expression (4), it is preferable to improve the mass productivity and availability of the material and reduce the cost.

  By making sure that the lower limit of 1.84 is not exceeded, the absolute value of the curvature of the lens surface can be reduced even if the power is secured, and it becomes easy to suppress the occurrence of spherical aberration and coma.

  Conditional expression (5) is a conditional expression related to chromatic aberration correction, in particular, off-axis chromatic aberration correction. In order to satisfactorily correct chromatic aberration caused by a large negative power within this group, it is preferable to use a material having a relatively large color dispersion within a proper range for the positive lens.

  It is preferable not to exceed the upper limit of 30.0 in conditional expression (4) to ensure dispersion and correct chromatic aberration generated in the negative lens.

  It is preferable not to fall below the lower limit of 13.0 so as to suppress chromatic dispersion on the short wavelength side and suppress chromatic aberration on the short wavelength side generated by the positive lens to suppress the generation of the secondary spectrum.

  It is better to do the following.

1.87 <n _d2p <2.15 (4) ′
15.0 <ν _d2p <26.0 (5) ′
It is even better to do the following:

1.90 <n _d2p <2.12 (4) ''
17.0 <ν _d2p <21.0 (5) ''
In order to reduce the occurrence of aberration in the second lens group, it is more preferable that the shape of the positive lens in the second lens group satisfies the following conditional expression.

0.45 <SF _2p <1.80 (6)
However, as defined in _{SF 2p = (R 2pf + R} 2pr) / (R 2pf -R 2pr),
R _2pf is the paraxial radius of curvature of the object side surface of the positive lens in the second lens group,
R _2pr is the paraxial radius of curvature of the image side surface of the positive lens in the second lens group,
It is.

  By forming the positive lens in a shape between the upper limit of 1.80 and the lower limit of 0.45 in conditional expression (6), it becomes easy to suppress the occurrence of spherical aberration and coma aberration in a well-balanced manner.

  It is better to do the following.

0.55 <SF _2p <1.6 (6) ′
It is even better to satisfy the following.

0.6 <SF _2p <1.3 (6) ''
The material of the negative lens closest to the object side in the second lens group preferably satisfies the following conditions.

1.78 <n _d2n1 <2.20 (7)
35 <ν _d2n1 <50 (8)
Where n _d2n1 is the refractive index of the object side negative lens in the second lens group with respect to the d-line,
ν _d2n1 is the Abbe number of the object side negative lens in the second lens group,
It is.

  It is preferable not to exceed the upper limit of 2.20 of conditional expression (7) to improve the mass productivity and availability of the material and reduce the cost. It is preferable that the absolute value of curvature of the lens surface is made small while ensuring the refractive power so as not to fall below the lower limit of 1.78 so that coma and curvature of field can be easily suppressed at the wide angle end.

  It is preferable not to exceed the upper limit of 50 in conditional expression (8) to ensure the availability of a material with a high refractive index. It is preferable not to fall below the lower limit of 35 so that chromatic dispersion is moderately suppressed and chromatic aberration is easily suppressed.

  It is better to do the following.

1.79 <n _d2n1 <1.95 (7) ′
37 <ν _d2n1 <47 (8) ′
It is even better to satisfy the following.

1.80 <n _d2n1 <1.90 (7) ''
40 <ν _d2n1 <43 (8) ''
It is preferable to set an optimum material for the negative lens closest to the image side in the second lens group. Specifically, the following conditional expression should be satisfied.

1.78 <n _d2n2 <2.00 (9)
35 < _Vd2n2 <50 (10)
Where n _d2n2 is the refractive index of the image-side negative lens in the second lens group with respect to the d-line,
V _d2n2 is the Abbe number of the image-side negative lens in the second lens group,
It is.

  It is preferable not to exceed the upper limit of 2.00 of the conditional expression (9) to improve the mass productivity and availability of the material and reduce the cost. By making it not below the lower limit of 1.78, the absolute value of the curvature of the lens surface can be reduced even if the refractive power is secured, and it becomes easy to suppress the occurrence of spherical aberration and coma.

  It is preferable to increase the availability of a material having a high refractive index so as not to exceed the upper limit of 50 in conditional expression (10). By making it not below the lower limit of 35, chromatic dispersion is suppressed, which is advantageous for correcting chromatic aberration.

  It is better to do the following.

1.79 <n _d2n2 <1.95 (9) ′
38 <V _d2n2 <48 (10) ′
It is even better to satisfy the following.

1.80 <n _d2n2 <1.90 (9) ''
40 <V _d2n2 <47 (10) ''
The shape of this negative lens should satisfy the following conditional expression.

−3.0 <SF _2n2 <−0.6 (11)
However, SF _2n2 = (R _2n2f + R _2n2r ) / (R _2n2f −R _2n2r ),
R _2n1f is the paraxial radius of curvature of the object side surface of the image-side negative lens in the second lens group,
R _2n1r is the paraxial radius of curvature of the image side surface of the image side negative lens in the second lens group,
It is.

  It is preferable not to exceed the upper limit of -0.6 of conditional expression (11) to suppress insufficient correction of field curvature. It is preferable that the absolute value of curvature of both lens surfaces is appropriately reduced so as not to fall below the lower limit of −3.0 so that the occurrence of spherical aberration and coma is easily suppressed.

  It is better to do the following.

−2.6 <SF _2n2 <−0.9 (11) ′
It is even better to satisfy the following.

-2.1 <SF _2n2 <-1.1 (11) ''

In addition, in order to satisfactorily correct aberrations, the positive lens of the second lens group should satisfy the following conditional expression.

−3.0 <f _2p / f ₂ <−1.0 (12)
Where f _2p is the focal length of the positive lens of the second lens group,
It is.

  By making the power of the positive lens moderately low so as not to exceed the upper limit of −1.0 of conditional expression (12), it becomes easy to suppress insufficient correction of field curvature. By ensuring that the power of the positive lens is appropriately secured so as not to fall below the lower limit of −3.0, it is advantageous for correcting spherical aberration and coma generated in the negative lens of the second lens group. In any case, it is advantageous to ensure good optical performance.

  It is better to do the following.

−2.8 <f _2p / f ₂ <−1.4 (12) ′
It is even better to satisfy the following.

-2.6 <f _2p / f ₂ <-1.8 (12) ''
Further, in order to further suppress the occurrence of aberrations and obtain good optical performance, it is preferable that at least one lens surface of the negative lens closest to the object side in the second lens group be an aspherical surface. Moreover, it is good also as a double-sided aspherical surface. Effective for correcting coma and curvature of field.

  At this time, it is preferable to satisfy the following conditional expression.

0.002 <(asp _2n1f + | asp _2n1r |) / f _w <0.10
... (13A)
−0.06 <(asp _2n1r −asp _2n1f ) / f _w <0.06 (13B)
Where asp _2n1f is the amount of aspherical deviation on the object-side lens surface of the object-side negative lens in the second lens group,
asp _2n1r is the amount of aspherical deviation on the image side lens surface of the object side negative lens in the second lens group,
f _w is the focal length of the entire zoom lens system at the wide-angle end,
As shown in FIG. 41, when the spherical surface having the same apex as that of the lens surface and having the paraxial radius of curvature of the lens surface as the radius of curvature is used as the reference spherical surface, as shown in FIG. The distance from the reference spherical surface to the lens surface when measured in the direction parallel to the optical axis at the position of the maximum light incident height at the wide-angle end on the surface, and the image side direction is a positive sign. When the lens surface is spherical or flat, the aspherical deviation amount is zero.

  By making sure that the lower limit of 0.002 of conditional expression (13A) is not exceeded, it becomes easy to secure the aberration correction effect due to the aspheric surface, and it becomes easy to suppress excessive barrel distortion. By not exceeding the upper limit of 0.10, the degree of aspherical shape change can be suppressed, and the influence of decentration on aberrations and excessive correction of coma can be easily suppressed.

  By making the upper limit of 0.06 of conditional expression (13B) not exceeded, it becomes easier for the field curvature to suppress overcorrection. By making it not below the lower limit of −0.06, it becomes easy to suppress insufficient correction of curvature of field. In any case, it is effective for obtaining good optical performance.

  It is better to do the following.

−0.059 <(asp _2n1r −asp _2n1f ) / fw <0.04 (13B) ′
It is even better to satisfy the following.

−0.055 <(asp _2n1r −asp _2n1f ) / fw <0.015
... (13B) ''
Furthermore, the object side surface of the object-side negative lens in the second lens group may be an aspheric surface whose refractive power increases as the distance from the optical axis increases (see Examples 1 to 10, 12, and 13).

  In addition, that refractive power becomes large means that negative refractive power becomes small or positive refractive power becomes large.

  Such a shape is advantageous for correcting off-axis aberrations at the wide-angle end.

  Further, the object side negative lens in the second lens group is a biconcave negative lens, and the object side surface of the biconcave negative lens is an aspheric surface whose negative refractive power decreases as the distance from the optical axis increases. Is preferably an aspheric surface in which the negative refractive power increases as the distance from the optical axis increases (see Examples 1 to 10).

  Such a shape is advantageous for correcting off-axis coma at the wide-angle end while securing negative power at the center and peripheral portions of the lens, and is advantageous for securing a field angle. Further, it is advantageous for reducing the thickness of the entire second lens group.

  It is effective in correcting aberrations if the image side surface of the negative lens closest to the image side in the second lens group is an aspherical surface. Effective for correcting spherical aberration and coma. At this time, it is preferable to satisfy the following conditional expression.

−0.09 <(asp _2n2r −asp _2n2f ) / f _w < _−0.003 (14)
Where asp _2n2f is the amount of aspherical deviation on the object-side lens surface of the image-side negative lens in the second lens group,
asp _2n2r is the amount of aspherical deviation on the image side lens surface of the image side negative lens in the second lens group,
f _w is the focal length of the entire zoom lens system at the wide-angle end,
As shown in FIG. 41, when the spherical surface having the same apex as that of the lens surface and having the paraxial radius of curvature of the lens surface as the radius of curvature is used as the reference spherical surface, as shown in FIG. This is the distance from the reference spherical surface to the lens surface when measured in the direction parallel to the optical axis at the position of the maximum light incident height at the wide-angle end on the surface, and the image side direction (right direction in the figure) is a positive sign And When the lens surface is spherical or flat, the aspherical deviation amount is zero.

  If the upper limit of -0.003 of conditional expression (14) is not exceeded, it is easy to suppress overcorrection of field curvature. If it does not fall below the lower limit of −0.09, it is advantageous for correction of spherical aberration and coma aberration. Both are advantageous for obtaining good optical performance.

  It is better to do the following.

−0.07 <(asp _2n2r −asp _2n2f ) / f _w <−0.005 (14) ′
It is even better to satisfy the following.

−0.05 <(asp _2n2r −asp _2n2f ) / f _w <−0.015 (14) ″
Further, the image side negative lens of the second lens group is a negative meniscus lens having a convex surface facing the image side, and the image side surface of the negative meniscus lens is an aspherical surface whose positive refractive power increases as the distance from the optical axis increases. It is preferable (see Examples 1 to 11 and 13).

  Such a configuration is advantageous in favorably correcting the spherical aberration and off-axis aberrations of the second lens group.

  The positive lens of the second lens group and the negative lens closest to the image may be independent single lenses that are not cemented or may be cemented lenses. When not joined, the degree of freedom of aberration correction using the air contact surface is increased. On the other hand, if it is joined, chromatic aberration correction is advantageous, and deterioration in yield due to optical performance deterioration due to relative decentration can be mitigated, leading to cost reduction.

  The first lens group preferably includes a positive lens and a negative lens in terms of correcting chromatic aberration.

  In particular, the first lens group may be an array of negative lenses and positive lenses in order from the object side. In this way, when considering the total of the first lens group and the second lens group, a configuration having good symmetry with the negative lens, the positive lens, the negative lens, the positive lens, and the negative lens in order from the object side. In particular, it is possible to efficiently cancel aberration generated in the synthesis system of the first lens group and the second lens group at the wide angle end. In addition, since the rear principal point position of the first lens group is closer to the image side, it is effective in securing a zoom ratio.

  The negative lens and the positive lens of the first lens group may be composed of independent lens components that are not joined.

  In this way, the coma aberration at the telephoto end can be particularly favorably corrected using the air lens formed between the two lenses.

  At this time, the distance between both lenses should satisfy the following conditional expression.

0.0 ≦ L _1np / L ₁ <0.2 (15)
Where L _1np is the distance between the negative lens and the positive lens in the first lens group,
L ₁ is the total thickness on the axis of the first lens group,
It is.

  If the upper limit of 0.2 in conditional expression (15) is exceeded, the height of off-axis rays passing through the lens closest to the object side becomes high, the effective lens diameter becomes large, and it becomes difficult to make the lens compact in the radial direction. The lower limit of 0.0 is not exceeded.

  It is better to do the following.

0.0 ≦ L _1np / L ₁ <0.16 (15) ′
It is even better to satisfy the following.

0.0 ≦ L _1np / L ₁ <0.12 (15) ″
Further, the negative lens and the positive lens of the first lens group may be cemented. The lateral chromatic aberration at the wide-angle end and the axial chromatic aberration at the telephoto end can be corrected well. In addition, yield deterioration due to performance deterioration due to relative eccentricity can be alleviated, leading to cost reduction.

  Further, even if the first lens group is composed of one positive lens, it is advantageous for size reduction and cost reduction.

  The configuration of the third lens group is preferably composed of three or less lenses in order to reduce the thickness of the lens barrel.

  In particular, it is preferable that the third lens group has a configuration including three lenses of a positive lens, a positive lens, and a negative lens in order from the object side. Dispersing the power of the positive lens between the two lenses and using the negative lens is advantageous for correcting spherical aberration, coma aberration, and chromatic aberration. In addition, since the principal point is closer to the object, it is advantageous for increasing the zoom ratio.

  Furthermore, it is preferable that the second positive lens and the negative lens from the object side of the third lens group are cemented on the optical axis. By joining the positive lens and the negative lens, the axial chromatic aberration can be corrected more effectively. Also, by dispersing the power of the positive lens between the two lenses and using the positive lens and the negative lens as a cemented lens, it is possible to prevent deterioration in optical performance due to the relative decentration of the lenses in the assembly process. Lead to improvement and cost reduction.

  Furthermore, arranging one or more aspheric surfaces in the third lens group is effective in correcting spherical aberration and coma. Particularly, the positive lens closest to the object side of the third lens group is a double-sided aspheric lens, which is advantageous for correcting various aberrations. If aspherical surfaces are arranged on a plurality of lenses, the optical performance deterioration due to the relative decentering of the lens tends to be large, but by making both sides of one lens aspherical in this way, the optical performance deterioration due to the lens relative decentering is reduced. While suppressing, spherical aberration and coma aberration can be corrected more favorably.

  The power of the second lens group should satisfy the following conditional expression.

0.20 <| f ₂ / f _t | <0.325 (16)
Where f _t is the focal length of the entire zoom lens system at the telephoto end,
It is.

  The upper limit of 0.325 in conditional expression (16) is not exceeded, so that power is secured and the amount of movement for zooming is suppressed, which is advantageous for making the lens barrel compact. Aberration correction is facilitated by suppressing the refractive power so as not to fall below the lower limit of 0.20.

  It is better to do the following.

_{0.25 <| f 2 / f t} | <0.320 ··· (16) '
It is even better to satisfy the following.

0.29 <| f ₂ / f _t | <0.315 (16) ''
From the viewpoint of compactness and balance of optical performance, it is desirable to set the power of the first lens group so as to satisfy the following conditional expression.

_{0.7 <f 1 / f t <} 1.8 ··· (17)
Where f ₁ is the combined focal length of the first lens group,
f _t is the focal length of the entire zoom lens system at the telephoto end,
It is.

  By securing the power of the first lens group so as not to exceed the upper limit of 1.8 of conditional expression (17), the entire length of the entire zoom lens system can be easily reduced and miniaturized. The power is moderately suppressed so as not to fall below the lower limit of 0.7, and spherical aberration and coma at the telephoto end can be easily suppressed.

  It is better to do the following.

_{1.0 <f 1 / f t <} 1.7 ··· (17) '
It is even better to satisfy the following.

_{1.3 <f 1 / f t <} 1.6 ··· (17) ''
The power of the third lens group should satisfy the following conditional expression.

0.25 <f ₃ / _ft <0.50 (18)
Where f ₃ is the focal length of the third lens group,
f _t is the focal length of the entire zoom lens system at the telephoto end,
It is.

  By securing the power so as not to exceed the upper limit of 0.50 of conditional expression (18), it is advantageous for shortening the overall length and securing the zoom ratio. By suppressing the refractive power so as not to fall below the lower limit of 0.25, it is advantageous for aberration correction.

  It is better to do the following.

0.30 <f ₃ / _ft <0.40 (18) ′
It is even better to satisfy the following.

_{0.34 <f 3 / f t <} 0.38 ··· (18) ''
Furthermore, when the fourth lens group having a positive refractive power is provided and the zoom lens is a four-group zoom lens as a whole, the power of the fourth lens group should satisfy the following conditional expression.

0.40 <f ₄ / _ft <1.0 (19)
Where f ₄ is the focal length of the fourth lens group,
f _t is the focal length of the entire zoom lens system at the telephoto end,
It is.

  It is preferable to ensure the action of refracting off-axis rays by ensuring the power of the fourth lens group so as not to exceed the upper limit of 1.0 of conditional expression (19). The angle of light incident on an electronic image sensor such as a CCD or CMOS arranged on the image plane can be reduced, and it becomes easy to suppress the occurrence of shading in the corners of the screen. By suppressing the power of the fourth lens group appropriately so as not to fall below the lower limit of 0.40, it becomes easy to suppress insufficient correction of field curvature. As described above, the focusing operation is desirably performed by moving the fourth lens group, but it is easy to suppress fluctuations in field curvature during focusing.

  It is better to do the following.

_{0.50 <f 4 / f t <} 0.80 ··· (19) '
It is even better to satisfy the following.

_{0.62 <f 4 / f t <} 0.66 ··· (19) ''
The fourth lens group may be formed of a plastic material. As a main role of the fourth lens group, it is preferable that the exit pupil position is arranged at an appropriate position so that a light beam is efficiently incident on an electronic image pickup device such as a CCD or a CMOS. For such a role, if the power is set within the range of the conditional expression (19), a relatively large power is not required, and a glass material having a low refractive index such as a plastic lens is used. It is also possible to use it. If a plastic lens is used for the fourth lens group, the cost can be reduced and a more inexpensive zoom lens can be provided.

  In order to achieve a high zoom ratio while maintaining the performance, it is preferable to efficiently apply a zooming action to each lens group and correct aberrations in a balanced manner in the entire zooming region.

  When the zoom lens of the present invention is a four-group zoom lens, the distance between the first lens group and the second lens group is widened at the time of zooming from the wide-angle end to the telephoto end, and the second lens group and the third lens group The first lens group, the second lens group, the third lens group, and the fourth lens group are configured to move so that the distance between the third lens group and the fourth lens group increases. preferable.

  By moving all the lens groups in this way, it becomes easier to perform zooming while maintaining aberration balance, which is advantageous for achieving a high zoom ratio. In addition, by moving the aperture stop, it is possible to effectively correct lateral chromatic aberration and distortion, and not only can be effective in terms of performance, but also the entrance pupil position and exit pupil position can be controlled appropriately. It becomes possible.

  Therefore, the angle of light incident on the CCD, CMOS, or the like can be maintained within an appropriate range, and the occurrence of shading in the corners of the screen can be prevented, which is suitable for an imaging apparatus using an electronic imaging device.

  Further, at the time of zooming from the wide angle end to the telephoto end, the first lens unit moves so as to be closer to the object side at the telephoto end than the wide angle end, the second lens unit moves, and the third lens unit moves toward the object side. It is preferable that the fourth lens unit move only. This is advantageous for securing a zoom ratio while reducing the overall length at the wide-angle end.

  At that time, the first lens group may be moved only to the object side, or may be moved along a locus convex toward the image side.

  The second lens group may be moved only to the image side, or may be moved along a locus convex toward the image side.

  The third lens group is preferably moved only to the object side.

  The fourth lens group may be moved only to the object side, or may be moved only to the image side. Alternatively, it may be moved along a locus convex toward the object side or convex toward the image side.

  An aperture stop and a shutter unit may be disposed between the second lens group and the third lens group, and the shutter unit may be moved together with the third lens group during zooming. The entrance pupil can be positioned close to the object side, and the exit pupil can be moved away from the image plane. In addition, since the off-axis light beam height is low, the shutter unit does not need to be enlarged, and the dead space when moving the aperture stop and the shutter unit can be reduced.

  The zoom lens according to the present invention preferably satisfies the following conditional expression.

3.8 < _ft / _fw <15.0 (21)
Where f _w is the focal length of the entire zoom lens system at the wide-angle end,
f _t is the focal length of the entire zoom lens system at the telephoto end,
It is.

  It is preferable not to exceed the upper limit of 15.0 of the conditional expression (21) so that the optical performance is easily secured. By ensuring the zoom ratio so as not to fall below the lower limit of 3.8, the zoom lens according to the present invention can sufficiently utilize the functions of downsizing and high zoom ratio.

  It is better to do the following.

4.2 <f _t / f _w <10.0 (21) ′
It is even better to satisfy the following.

4.5 < _ft / _fw <6 (21) ''
The present invention includes an electronic imaging apparatus having the above-described zoom lens and an electronic imaging device that is disposed on the image side and converts an optical image formed by the zoom lens into an electrical signal.

  In addition, such an electronic imaging device preferably satisfies the following conditional expression.

0.70 <I _m / f _w <1.00 (20)
Where _Im is the maximum image height,
f _w is the focal length of the entire zoom lens system at the wide-angle end,
It is.

  By making sure that the upper limit of 1.00 of the conditional expression (20) is not exceeded, it is advantageous to prevent the shooting angle of view from becoming too large and to reduce the occurrence of Tal distortion. It is preferable not to fall below the lower limit of 0.70 and take advantage of the small size and wide angle by adopting this configuration.

  It is better to do the following.

0.72 <I _m / f _w <0.90 (20) ′
It is even better to satisfy the following.

0.74 <I _m / f _w <0.77 (20) ''

According to the present invention, the number of lenses of the first lens group and the second lens group is reduced, the thickness of the second lens group is reduced, the distance from the first lens group is easily made closer, and the size and magnification are reduced. It is possible to provide a zoom lens that facilitates ensuring optical performance while ensuring the ratio. In addition, by providing such a zoom lens, it is possible to provide an electronic imaging device that can be easily miniaturized. Furthermore, by devising each lens group of the zoom lens and the like, it is possible to provide a zoom lens and an electronic image pickup device that are easier to miniaturize, ensure aberration performance, and ensure a zoom ratio.

  In the embodiment based on the present invention shown below, the above-described device is used to reduce the size of the camera so that it can satisfy the user's desire to expand the shooting area more than before without impairing the portability of the camera. Provides an inexpensive zoom lens optical system that is suitable for electronic image sensors such as CCDs and CMOSs that satisfy both the wide angle and the high zoom ratio at the same time, and that maintains the image quality of captured images. .

  Specifically, it is suitable for thinning when the lens barrel is retracted, and has a wide angle of view of about 39 ° and a high zoom ratio of about 5 times. An inexpensive zoom lens optical system suitable for an electronic image pickup device such as a CCD or a CMOS having good image quality is provided.

  Examples 1 to 20 of the zoom lens according to the present invention will be described below. Lens cross-sectional views at the wide-angle end (a), the intermediate state (b), and the telephoto end (c) when focusing on an object point at infinity in Examples 1 to 20 are shown in FIGS. In each figure, the first lens group is G1, the second lens group is G2, the aperture stop is S, the third lens group is G3, the fourth lens group is G4, the fifth lens group is G5, and the optical low-pass filter is F. The cover glass of the CCD, which is an electronic image sensor, is indicated by C, and the image plane of the CCD is indicated by I. As for the near-infrared sharp cut coat, for example, the optical low-pass filter F may be directly coated, or an infrared cut absorption filter may be separately arranged.

  As shown in FIG. 1, the zoom lens according to the first embodiment includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, an aperture stop S, and a third lens having a positive refractive power. The lens group G3 includes a fourth lens group G4 having a positive refractive power. When zooming from the wide-angle end to the telephoto end, the first lens group G1 moves to the object side, and the second lens group G2 Moves to the image side. The aperture stop S and the third lens group G3 move integrally toward the object side, the fourth lens group G4 moves along a convex locus toward the object side while widening the distance from the third lens group G3, and the wide-angle end at the telephoto end. It is located slightly on the object side from the position of.

  In order from the object side, the first lens group G1 includes a negative meniscus lens having a convex surface facing the object side and a positive meniscus lens having a convex surface facing the object side. The second lens group G2 includes a biconcave negative lens, The third lens group G3 includes a positive meniscus lens having a convex surface directed toward the image side and a negative meniscus lens having a convex surface directed toward the image side. The third lens group G3 includes a biconvex positive lens, a positive meniscus lens having a convex surface directed toward the object side, and an object The fourth lens group G4 is composed of a single biconvex positive lens.

  The aspheric surfaces are the double-sided negative lens of the second lens group G2, the image side surface of the negative meniscus lens, the double-sided positive lens of the third lens group G3, and the double-convex positive lens of the fourth lens group G4. It is used for 6 surfaces on the object side.

  As shown in FIG. 2, the zoom lens according to the second embodiment includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, an aperture stop S, and a third lens having a positive refractive power. The lens group G3 includes a fourth lens group G4 having a positive refractive power. When zooming from the wide-angle end to the telephoto end, the first lens group G1 moves to the object side, and the second lens group G2 Moves to the image side. The aperture stop S and the third lens group G3 move integrally toward the object side, the fourth lens group G4 moves along a convex locus toward the object side while widening the distance from the third lens group G3, and the wide-angle end at the telephoto end. It is located slightly on the object side from the position of.

  In order from the object side, the first lens group G1 includes a negative meniscus lens having a convex surface facing the object side and a positive meniscus lens having a convex surface facing the object side. The second lens group G2 includes a biconcave negative lens, The third lens group G3 includes a positive meniscus lens having a convex surface directed toward the image side and a negative meniscus lens having a convex surface directed toward the image side. The third lens group G3 includes a biconvex positive lens, a positive meniscus lens having a convex surface directed toward the object side, and an object The fourth lens group G4 is composed of a single biconvex positive lens.

  The aspheric surfaces are the double-sided negative lens of the second lens group G2, the image side surface of the negative meniscus lens, the double-sided positive lens of the third lens group G3, and the double-convex positive lens of the fourth lens group G4. It is used for 6 surfaces on the object side.

  As shown in FIG. 3, the zoom lens of Example 3 includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, an aperture stop S, and a third lens having a positive refractive power. The lens group G3 includes a fourth lens group G4 having a positive refractive power. When zooming from the wide-angle end to the telephoto end, the first lens group G1 moves to the object side, and the second lens group G2 Moves to the image side. The aperture stop S and the third lens group G3 move integrally toward the object side, the fourth lens group G4 moves along a convex locus toward the object side while widening the distance from the third lens group G3, and the wide-angle end at the telephoto end. It is located slightly on the object side from the position of.

  In order from the object side, the first lens group G1 includes a negative meniscus lens having a convex surface facing the object side and a positive meniscus lens having a convex surface facing the object side. The second lens group G2 includes a biconcave negative lens, The third lens group G3 includes a positive meniscus lens having a convex surface directed toward the image side and a negative meniscus lens having a convex surface directed toward the image side. The third lens group G3 includes a biconvex positive lens, a positive meniscus lens having a convex surface directed toward the object side, and an object The fourth lens group G4 is composed of a single biconvex positive lens.

  The aspheric surfaces are the double-sided negative lens of the second lens group G2, the image side surface of the negative meniscus lens, the double-sided positive lens of the third lens group G3, and the double-convex positive lens of the fourth lens group G4. It is used for 6 surfaces on the object side.

  As shown in FIG. 4, the zoom lens of Example 4 includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, an aperture stop S, and a third lens having a positive refractive power. The lens group G3 includes a fourth lens group G4 having a positive refractive power. When zooming from the wide-angle end to the telephoto end, the first lens group G1 moves to the object side, and the second lens group G2 Moves to the image side. The aperture stop S and the third lens group G3 move integrally toward the object side, the fourth lens group G4 moves along a convex locus toward the object side while widening the distance from the third lens group G3, and the wide-angle end at the telephoto end. It is located slightly on the object side from the position of.

  In order from the object side, the first lens group G1 includes a negative meniscus lens having a convex surface facing the object side and a positive meniscus lens having a convex surface facing the object side. The second lens group G2 includes a biconcave negative lens, The third lens group G3 is composed of a cemented lens composed of a positive meniscus lens having a convex surface directed toward the image side and a negative meniscus lens having a convex surface directed toward the image side. The third lens group G3 includes a biconvex positive lens and a positive meniscus lens having a convex surface directed toward the object side. The fourth lens group G4 is composed of one biconvex positive lens. The cemented lens is composed of a lens and a negative meniscus lens having a convex surface facing the object side.

  The aspheric surfaces are the double-sided negative lens of the second lens group G2, the most image-side surface of the cemented lens, the double-sided positive lens of the third lens group G3, and the double-convex positive lens of the fourth lens group G4. It is used for 6 surfaces on the object side.

  As shown in FIG. 5, the zoom lens of Example 5 includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, an aperture stop S, and a third lens having a positive refractive power. The lens group G3 includes a fourth lens group G4 having a positive refractive power. When zooming from the wide-angle end to the telephoto end, the first lens group G1 moves to the object side, and the second lens group G2 Moves to the image side. The aperture stop S and the third lens group G3 move integrally toward the object side, the fourth lens group G4 moves along a convex locus toward the object side while widening the distance from the third lens group G3, and the wide-angle end at the telephoto end. It is located slightly on the object side from the position of.

  In order from the object side, the first lens group G1 includes a negative meniscus lens having a convex surface facing the object side and a biconvex positive lens, and the second lens group G2 has a biconcave negative lens and a convex surface facing the image side. The third lens group G3 includes a biconvex positive lens, a positive meniscus lens having a convex surface facing the object side, and a convex surface facing the object side. The fourth lens group G4 is composed of a single biconvex positive lens.

  The aspheric surfaces are the double-sided negative lens of the second lens group G2, the most image-side surface of the cemented lens, the double-sided positive lens of the third lens group G3, and the double-convex positive lens of the fourth lens group G4. It is used for 6 surfaces on the object side.

  As shown in FIG. 6, the zoom lens of Example 6 includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, an aperture stop S, and a third lens having a positive refractive power. The lens group G3 includes a fourth lens group G4 having a positive refractive power. When zooming from the wide-angle end to the telephoto end, the first lens group G1 moves to the object side, and the second lens group G2 Moves to the image side. The aperture stop S and the third lens group G3 move integrally toward the object side, the fourth lens group G4 moves along a convex locus toward the object side while widening the distance from the third lens group G3, and the wide-angle end at the telephoto end. It is located slightly on the object side from the position of.

  In order from the object side, the first lens group G1 includes a negative meniscus lens having a convex surface facing the object side and a positive meniscus lens having a convex surface facing the object side. The second lens group G2 includes a biconcave negative lens, The third lens group G3 includes a positive meniscus lens having a convex surface directed toward the image side and a negative meniscus lens having a convex surface directed toward the image side. The third lens group G3 includes a biconvex positive lens, a positive meniscus lens having a convex surface directed toward the object side, and an object It consists of a cemented lens with a negative meniscus lens with its side convex surface facing, and the fourth lens group G4 consists of one biconvex positive lens.

  The aspheric surfaces are the double-sided negative lens of the second lens group G2, the image side surface of the negative meniscus lens, the double-sided positive lens of the third lens group G3, and the double-convex positive lens of the fourth lens group G4. It is used for 6 surfaces on the object side.

  As shown in FIG. 7, the zoom lens according to the seventh exemplary embodiment includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, an aperture stop S, and a third lens having a positive refractive power. The lens group G3 includes a fourth lens group G4 having a positive refractive power. When zooming from the wide-angle end to the telephoto end, the first lens group G1 moves to the object side, and the second lens group G2 Moves to the image side. The aperture stop S and the third lens group G3 move integrally toward the object side, the fourth lens group G4 moves along a convex locus toward the object side while widening the distance from the third lens group G3, and the wide-angle end at the telephoto end. It is located slightly on the object side from the position of.

  In order from the object side, the first lens group G1 includes a negative meniscus lens having a convex surface facing the object side and a positive meniscus lens having a convex surface facing the object side. The second lens group G2 includes a biconcave negative lens, The third lens group G3 includes a positive meniscus lens having a convex surface directed toward the image side and a negative meniscus lens having a convex surface directed toward the image side. The third lens group G3 includes a biconvex positive lens, a positive meniscus lens having a convex surface directed toward the object side, and an object It consists of a cemented lens with a negative meniscus lens with its side convex surface facing, and the fourth lens group G4 consists of one biconvex positive lens.

  The aspheric surfaces are the double-sided negative lens of the second lens group G2, the image side surface of the negative meniscus lens, the double-sided positive lens of the third lens group G3, and the double-convex positive lens of the fourth lens group G4. It is used for 6 surfaces on the object side.

  As shown in FIG. 8, the zoom lens according to the eighth embodiment includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, an aperture stop S, and a third lens having a positive refractive power. The lens group G3 includes a fourth lens group G4 having a positive refractive power. When zooming from the wide-angle end to the telephoto end, the first lens group G1 moves to the object side, and the second lens group G2 Moves to the image side. The aperture stop S and the third lens group G3 move integrally toward the object side, the fourth lens group G4 moves along a convex locus toward the object side while widening the distance from the third lens group G3, and the wide-angle end at the telephoto end. It is located slightly on the object side from the position of.

  In order from the object side, the first lens group G1 includes a negative meniscus lens having a convex surface facing the object side and a positive meniscus lens having a convex surface facing the object side. The second lens group G2 includes a biconcave negative lens, The third lens group G3 is composed of a cemented lens composed of a positive meniscus lens having a convex surface directed toward the image side and a negative meniscus lens having a convex surface directed toward the image side. The third lens group G3 includes a biconvex positive lens and a positive meniscus lens having a convex surface directed toward the object side. The fourth lens group G4 is composed of one biconvex positive lens. The cemented lens is composed of a lens and a negative meniscus lens having a convex surface facing the object side.

  The aspheric surfaces are the double-sided negative lens of the second lens group G2, the most image-side surface of the cemented lens, the double-sided positive lens of the third lens group G3, and the double-convex positive lens of the fourth lens group G4. It is used for 6 surfaces on the object side.

  As shown in FIG. 9, the zoom lens according to the ninth embodiment includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, an aperture stop S, and a third lens having a positive refractive power. The lens group G3 includes a fourth lens group G4 having a positive refractive power. When zooming from the wide-angle end to the telephoto end, the first lens group G1 moves to the object side, and the second lens group G2 Moves to the image side. The aperture stop S and the third lens group G3 move integrally toward the object side, the fourth lens group G4 moves along a convex locus toward the object side while widening the distance from the third lens group G3, and the wide-angle end at the telephoto end. It is located slightly on the object side from the position of.

  In order from the object side, the first lens group G1 includes a negative meniscus lens having a convex surface facing the object side and a positive meniscus lens having a convex surface facing the object side. The second lens group G2 includes a biconcave negative lens, The third lens group G3 is composed of a cemented lens composed of a positive meniscus lens having a convex surface directed toward the image side and a negative meniscus lens having a convex surface directed toward the image side. The third lens group G3 includes a biconvex positive lens and a positive meniscus lens having a convex surface directed toward the object side. The fourth lens group G4 is composed of one biconvex positive lens. The cemented lens is composed of a lens and a negative meniscus lens having a convex surface facing the object side.

  The aspheric surfaces are the double-sided negative lens of the second lens group G2, the most image-side surface of the cemented lens, the double-sided positive lens of the third lens group G3, and the double-convex positive lens of the fourth lens group G4. It is used for 6 surfaces on the object side.

  As shown in FIG. 10, the zoom lens of Example 10 includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, an aperture stop S, and a third lens having a positive refractive power. The lens unit G3 includes a fourth lens unit G4 having positive refracting power. When zooming from the wide angle end to the telephoto end, the first lens unit G1 moves along a locus convex toward the image side. In the state, it is located slightly on the image side from the wide-angle end position, and on the telephoto end is located closer to the object side than the wide-angle end position. The second lens group G2 moves to the image side while increasing the distance from the first lens group G1. . The aperture stop S and the third lens group G3 integrally move toward the object side, and the fourth lens group G4 moves toward the object side while increasing the distance from the third lens group G3 from the wide-angle end to the intermediate state. From the telephoto end to the telephoto end is substantially fixed.

  In order from the object side, the first lens group G1 is composed of a cemented lens of a negative meniscus lens having a convex surface facing the object side and a positive meniscus lens having a convex surface facing the object side, and the second lens group G2 is a biconcave negative lens. The third lens group G3 includes a biconvex positive lens, a positive meniscus lens having a convex surface facing the object side, and a convex surface facing the object side. The fourth lens group G4 is composed of a single biconvex positive lens.

  The aspheric surfaces are the double-sided negative lens of the second lens group G2, the image side surface of the negative meniscus lens, the double-sided positive lens of the third lens group G3, and the double-convex positive lens of the fourth lens group G4. It is used for 6 surfaces on the object side.

  As shown in FIG. 11, the zoom lens of Example 11 includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, an aperture stop S, and a third lens having a positive refractive power. The lens group G3 includes a fourth lens group G4 having a positive refractive power. When zooming from the wide-angle end to the telephoto end, the first lens group G1 moves to the object side, and the second lens group G2 Moves to the image side. The aperture stop S and the third lens group G3 move integrally toward the object side, the fourth lens group G4 moves along a convex locus toward the object side while widening the distance from the third lens group G3, and the wide-angle end at the telephoto end. It is located slightly on the object side from the position of.

  In order from the object side, the first lens group G1 includes a negative meniscus lens having a convex surface facing the object side and a positive meniscus lens having a convex surface facing the object side. The second lens group G2 includes a biconcave negative lens, The third lens group G3 includes a positive meniscus lens having a convex surface directed toward the image side and a negative meniscus lens having a convex surface directed toward the image side. The third lens group G3 includes a biconvex positive lens, a positive meniscus lens having a convex surface directed toward the object side, and an object The fourth lens group G4 is composed of a single biconvex positive lens.

  The aspheric surfaces are the double-sided negative lens of the second lens group G2, the object side surface of the negative meniscus lens, the double-sided positive lens of the third lens group G3, and the biconvex positive lens of the fourth lens group G4. It is used for 6 surfaces on the object side.

  As shown in FIG. 12, in the zoom lens of Example 12, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, an aperture stop S, and a third lens having a positive refractive power. The lens group G3 includes a fourth lens group G4 having a positive refractive power. When zooming from the wide-angle end to the telephoto end, the first lens group G1 moves to the object side, and the second lens group G2 Moves to the image side. The aperture stop S and the third lens group G3 move integrally toward the object side, the fourth lens group G4 moves along a convex locus toward the object side while widening the distance from the third lens group G3, and the wide-angle end at the telephoto end. It is located slightly on the object side from the position of.

  In order from the object side, the first lens group G1 includes a negative meniscus lens having a convex surface facing the object side and a positive meniscus lens having a convex surface facing the object side. The second lens group G2 includes a biconcave negative lens, The third lens group G3 includes a positive meniscus lens having a convex surface directed toward the image side and a negative meniscus lens having a convex surface directed toward the image side. The third lens group G3 includes a biconvex positive lens, a positive meniscus lens having a convex surface directed toward the object side, and an object The fourth lens group G4 is composed of a single biconvex positive lens.

  The aspheric surfaces are the double-sided negative lens of the second lens group G2, both sides of the negative meniscus lens, both sides of the biconvex positive lens of the third lens group G3, and the object side of the biconvex positive lens of the fourth lens group G4. It is used for 6 surfaces.

  As shown in FIG. 13, the zoom lens according to the thirteenth embodiment includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, an aperture stop S, and a third lens having a positive refractive power. The lens group G3 includes a fourth lens group G4 having negative refracting power and a fifth lens group G5 having positive refracting power. When zooming from the wide-angle end to the telephoto end, the first lens group G1 is an object. The second lens group G2 moves to the image side. The aperture stop S and the third lens group G3 move integrally to the object side, the fourth lens group G4 moves to the object side while once widening and narrowing the distance from the third lens group G3, and the fifth lens group G5 It moves to the object side while widening the distance from the fourth lens group G4.

  In order from the object side, the first lens group G1 includes a negative meniscus lens having a convex surface facing the object side and a positive meniscus lens having a convex surface facing the object side. The second lens group G2 includes a biconcave negative lens, It consists of a cemented lens of a positive meniscus lens having a convex surface facing the image side and a negative meniscus lens having a convex surface facing the image side. The third lens group G3 is composed of one biconvex positive lens, and the fourth lens group G4 is The fifth lens group G5 is composed of a single biconvex positive lens. The cemented lens is composed of a positive meniscus lens having a convex surface facing the object side and a negative meniscus lens having a convex surface facing the object side.

  The aspheric surfaces are the double-sided negative lens of the second lens group G2, the most image side surface of the cemented lens, the double-sided positive lens of the third lens group G3, and the double-convex positive lens of the fifth lens group G5. It is used for 6 surfaces on the object side.

  As shown in FIG. 14, the zoom lens of Example 14 includes a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, an aperture stop S, and a third lens having a positive refractive power in order from the object side. The lens group G3 includes a fourth lens group G4 having negative refracting power and a fifth lens group G5 having positive refracting power. When zooming from the wide-angle end to the telephoto end, the first lens group G1 is an object. The second lens group G2 moves to the image side. The aperture stop S and the third lens group G3 move integrally to the object side, the fourth lens group G4 moves to the object side while once widening and narrowing the distance from the third lens group G3, and the fifth lens group G5 It moves along a convex locus toward the object side while increasing the distance from the fourth lens group G4, and is slightly closer to the object side at the telephoto end than at the wide-angle end.

  In order from the object side, the first lens group G1 includes a negative meniscus lens having a convex surface facing the object side and a positive meniscus lens having a convex surface facing the object side. The second lens group G2 includes a biconcave negative lens, A positive meniscus lens having a convex surface facing the image side and a negative meniscus lens having a convex surface facing the image side. The third lens group G3 includes one biconvex positive lens, and the fourth lens group G4 includes the object side. The fifth lens group G5 is composed of a single biconvex positive lens. The cemented lens is composed of a positive meniscus lens having a convex surface facing the convex surface and a negative meniscus lens having a convex surface facing the object side.

  The aspherical surfaces include both surfaces of the biconcave negative lens of the second lens group G2, the object side surface of the negative meniscus lens, both surfaces of the biconvex positive lens of the third lens group G3, and the biconvex positive lens of the fifth lens group G5. It is used for 6 surfaces on the object side.

  As shown in FIG. 15, the zoom lens according to the fifteenth embodiment includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, an aperture stop S, and a third lens having a positive refractive power. The lens group G3 includes a fourth lens group G4 having negative refracting power and a fifth lens group G5 having positive refracting power. When zooming from the wide-angle end to the telephoto end, the first lens group G1 is an object. The second lens group G2 moves along a locus convex toward the image side, and is located closer to the image side at the telephoto end than at the wide-angle end. The aperture stop S and the third lens group G3 move integrally to the object side, the fourth lens group G4 moves to the object side while once widening and narrowing the distance from the third lens group G3, and the fifth lens group G5 It moves along a convex locus toward the object side while increasing the distance from the fourth lens group G4, and is slightly closer to the object side at the telephoto end than at the wide-angle end.

  In order from the object side, the first lens group G1 includes a negative meniscus lens having a convex surface facing the object side and a biconvex positive lens, and the second lens group G2 has a biconcave negative lens and a convex surface facing the image side. A positive meniscus lens and a negative meniscus lens having a convex surface facing the image side. The third lens group G3 includes one biconvex positive lens, and the fourth lens group G4 has a convex surface on the object side. The fifth lens group G5 is composed of one biconvex positive lens. The cemented lens is composed of a positive meniscus lens directed toward the object and a negative meniscus lens having a convex surface directed toward the object side.

  The aspheric surfaces are the double-sided negative lens of the second lens group G2, the most image side surface of the cemented lens, the double-sided positive lens of the third lens group G3, and the double-convex positive lens of the fifth lens group G5. It is used for 6 surfaces on the object side.

  As shown in FIG. 16, the zoom lens of Example 16 includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, an aperture stop S, and a third lens having a positive refractive power. The first lens group G1 is composed of a lens group G3, a fourth lens group G4 having negative refractive power, and a fifth lens group G5 having positive refractive power. When changing the magnification from the wide angle end to the telephoto end, the first lens group G1 is an image. In the intermediate state, it moves slightly closer to the image side than the wide-angle end position, and at the telephoto end it is closer to the object side than the wide-angle end position. The second lens group G2 moves to the image side. The aperture stop S and the third lens group G3 integrally move along a convex locus toward the object side, are slightly on the image side at the telephoto end from the intermediate position, and are closer to the object side than the wide-angle end. The group G4 moves along a convex locus toward the object side while once increasing and narrowing the distance from the third lens group G3, and is slightly closer to the image side than the intermediate position at the telephoto end and closer to the object side than the wide-angle end position. The fifth lens group G5 moves along a locus convex toward the object side while temporarily increasing the distance from the fourth lens group G4 and then slightly narrowing it, and is positioned slightly closer to the object side than the wide-angle end position at the telephoto end.

  In order from the object side, the first lens group G1 is composed of a cemented lens of a negative meniscus lens having a convex surface facing the object side and a positive meniscus lens having a convex surface facing the object side, and the second lens group G2 is a biconcave negative lens. The lens includes a positive meniscus lens having a convex surface facing the image side, and a negative meniscus lens having a convex surface facing the image side. The third lens group G3 includes one biconvex positive lens, and the fourth lens group G4 includes The fifth lens group G5 is composed of a single biconvex positive lens. The cemented lens is composed of a positive meniscus lens having a convex surface facing the object side and a negative meniscus lens having a convex surface facing the object side.

  The aspheric surfaces are the double-sided negative lens of the second lens group G2, the image side surface of the negative meniscus lens, the double-sided positive lens of the third lens group G3, and the double-convex positive lens of the fifth lens group G5. It is used for 6 surfaces on the object side.

  As shown in FIG. 17, the zoom lens according to the seventeenth embodiment includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, an aperture stop S, and a third lens having a positive refractive power. The lens group G3 includes a fourth lens group G4 having negative refracting power and a fifth lens group G5 having positive refracting power. When zooming from the wide-angle end to the telephoto end, the first lens group G1 is an object. The second lens group G2 moves to the image side. The aperture stop S and the third lens group G3 move integrally to the object side, the fourth lens group G4 moves to the object side while temporarily widening and then narrowing the distance from the third lens group G3, and the fifth lens group G5 It moves along a convex locus toward the object side while increasing the distance from the fourth lens group G4, and is slightly closer to the object side at the telephoto end than at the wide-angle end.

  In order from the object side, the first lens group G1 includes a negative meniscus lens having a convex surface facing the object side and a positive meniscus lens having a convex surface facing the object side. The second lens group G2 includes a biconcave negative lens, A positive meniscus lens having a convex surface facing the image side and a negative meniscus lens having a convex surface facing the image side. The third lens group G3 includes one biconvex positive lens, and the fourth lens group G4 includes the object side. The fifth lens group G5 is composed of a single biconvex positive lens. The cemented lens is composed of a positive meniscus lens having a convex surface facing the convex surface and a negative meniscus lens having a convex surface facing the object side.

  The aspheric surfaces are the double-sided negative lens of the second lens group G2, the image side surface of the negative meniscus lens, the double-sided positive lens of the third lens group G3, and the double-convex positive lens of the fifth lens group G5. It is used for 6 surfaces on the object side.

  As shown in FIG. 18, in the zoom lens of Example 18, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, an aperture stop S, and a third lens having a positive refractive power. The lens group G3 includes a fourth lens group G4 having a positive refractive power. When zooming from the wide-angle end to the telephoto end, the first lens group G1 moves to the object side, and the second lens group G2 Moves to the image side. The aperture stop S and the third lens group G3 move together toward the object side, and the fourth lens group G4 moves toward the object side while increasing the distance from the third lens group G3.

  In order from the object side, the first lens group G1 includes a single positive meniscus lens having a convex surface directed toward the object side, and the second lens group G2 includes a biconcave negative lens, a biconvex positive lens, and a convex surface on the image side. The third lens group G3 is composed of a cemented lens of a biconvex positive lens, a positive meniscus lens having a convex surface directed toward the object side, and a negative meniscus lens having a convex surface directed toward the object side, The fourth lens group G4 is composed of one positive meniscus lens having a convex surface directed toward the image side.

  The aspheric surfaces are both surfaces of the positive meniscus lens of the first lens group G1, both surfaces of the biconcave negative lens of the second lens group G2, the image side surface of the negative meniscus lens, and both surfaces of the biconvex positive lens of the third lens group G3. , And are used for eight surfaces on the object side of the positive meniscus lens in the fourth lens group G4.

  As shown in FIG. 19, the zoom lens of Example 19 includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, an aperture stop S, and a third lens having a positive refractive power. The lens group G3 includes a fourth lens group G4 having a positive refractive power. When zooming from the wide-angle end to the telephoto end, the first lens group G1 moves to the object side, and the second lens group G2 Moves to the image side. The aperture stop S and the third lens group G3 move together toward the object side, and the fourth lens group G4 moves toward the object side while increasing the distance from the third lens group G3.

  In order from the object side, the first lens group G1 includes one positive meniscus lens having a convex surface directed toward the object side, and the second lens group G2 includes a biconcave negative lens, a biconvex positive lens, and a biconcave negative lens. The third lens group G3 includes a cemented lens of a biconvex positive lens, a positive meniscus lens having a convex surface facing the object side, and a negative meniscus lens having a convex surface facing the object side, and the fourth lens group G4 includes And one positive meniscus lens having a convex surface facing the image side.

  The aspheric surfaces are both surfaces of the positive meniscus lens of the first lens group G1, both surfaces of the object side biconcave negative lens of the second lens group G2, the image side surface of the image side biconcave negative lens, and the third lens group G3. Are used on both surfaces of the biconvex positive lens and on the object side surface of the positive meniscus lens in the fourth lens group G4.

  As shown in FIG. 20, in the zoom lens of Example 20, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, an aperture stop S, and a third lens having a positive refractive power. The lens group G3 includes a fourth lens group G4 having a positive refractive power. When zooming from the wide-angle end to the telephoto end, the first lens group G1 moves to the object side, and the second lens group G2 Moves to the image side. The aperture stop S moves to the object side independently of the third lens group G3, and the third lens group G3 narrows the distance from the aperture stop S from the wide-angle end to the intermediate state and widens from the intermediate state to the telephoto end. While moving to the object side. The fourth lens group G4 slightly moves toward the object side while widening the distance from the third lens group G3.

  In order from the object side, the first lens group G1 includes a negative meniscus lens having a convex surface directed toward the object side, and a biconvex positive lens. The second lens group G2 includes a biconcave negative lens, a biconvex positive lens, The third lens group G3 is composed of a cemented lens of a biconvex positive lens, a positive meniscus lens having a convex surface facing the object side, and a negative meniscus lens having a convex surface facing the object side. The fourth lens group G4 is composed of one biconvex positive lens.

  The aspheric surfaces are the double-sided negative lens of the second lens group G2, the most image-side surface of the cemented lens, the double-sided positive lens of the third lens group G3, and the double-convex positive lens of the fourth lens group G4. It is used for 6 surfaces on the object side.

The numerical data of each example is shown below. Symbols are the above, f is the total focal length, F _no is the F number, 2ω is the angle of view, WE is the wide angle end, ST is the intermediate state, and TE is telephoto. End, r ₁ , r ₂ ... Curvature radius of each lens surface, d ₁ , d ₂ ... Spacing between each lens surface, n _d1 , n _d2 ..., Refractive index of d-line of each lens, ν _d1 , ν _d2 ... is the Abbe number of each lens. The aspherical shape is represented by the following expression, where x is an optical axis with the light traveling direction being positive, and y is a direction orthogonal to the optical axis.

    x = (y²/ R) / [1+ {1- (K + 1) (y / r)²}^1/2]
                                    + A_Foury^Four+ A₆y⁶+ A₈y⁸+ A_Teny^Ten
  Where r is the paraxial radius of curvature, K is the cone coefficient, A_Four, A₆, A₈, A_TenAre the 4th, 6th, 8th and 10th order aspherical coefficients, respectively.

Example 1
r₁= 19.996 d₁= 0.80 n_d1= 1.92286 ν_d1= 18.90
r₂= 15.394 d₂= 0.26
r_Three= 17.278 d_Three= 3.11 n_d2= 1.76802 ν_d2= 49.24
r_Four= 534.344 d_Four= (Variable)
r_Five= -58.703 (Aspherical surface) d_Five= 0.82 n_d3= 1.88300 ν_d3= 40.76
r₆= 5.969 (aspherical surface) d₆= 2.65
r₇= -431.058 d₇= 1.95 n_d4= 2.00170 ν_d4= 20.64
r₈= -14.597 d₈= 0.07
r₉= -13.708 d₉= 0.67 n_d5= 1.81600 ν_d5= 46.62
r_Ten= -67.948 (aspherical surface) d_Ten= (Variable)
r₁₁= ∞ (aperture) d₁₁= 0.10
r₁₂= 5.491 (aspherical surface) d₁₂= 2.70 n_d6= 1.58913 ν_d6= 61.14
r₁₃= -11.075 (aspherical surface) d₁₃= 0.10
r₁₄= 5.503 d₁₄= 1.38 n_d7= 1.59201 ν_d7= 67.02
r₁₅= 13.913 d₁₅= 0.80 n_d8= 2.00069 ν_d8= 25.46
r₁₆= 3.463 d₁₆= (Variable)
r₁₇= 19.919 (aspherical surface) d₁₇= 2.07 n_d9= 1.74330 ν_d9= 49.33
r₁₈= -25.922 d₁₈= (Variable)
r₁₉= ∞ d₁₉= 0.40 n_d10= 1.54771 ν_d10= 62.84
r₂₀= ∞ d₂₀= 0.50
r_{twenty one}= ∞ d_{twenty one}= 0.50 n_d11= 1.51633 ν_d11= 64.14
r_{twenty two}= ∞ d_{twenty two}= 0.36
r_{twenty three}= ∞ (image plane)
Aspheric coefficient
    5th page
    K = 0.000
    A_Four= 1.99104 × 10^-Four
    A₆= -8.59909 × 10^-6
    A₈= 2.01071 × 10^-7
    A_Ten= -1.73584 × 10^-9
    6th page
    K = 0.000
    A_Four= 7.61962 × 10^-Five
    A₆= 2.30339 × 10^-Five
    A₈= -1.98717 × 10^-6
    A_Ten= 4.99512 × 10^-8
    10th page
    K = 10.849
    A_Four= -2.64668 × 10^-Four
    A₆= -1.16671 × 10^-6
    A₈= -1.29451 × 10^-7
    A_Ten= 0
    12th page
    K = -0.000
    A_Four= -9.20803 × 10^-Four
    A₆= 7.90503 × 10^-6
    A₈= -4.58612 × 10^-6
    A_Ten= 5.46733 × 10^-7
    13th page
    K = 0.000
    A_Four= 5.31169 × 10^-Four
    A₆= 2.85804 × 10^-Five
    A₈= -8.58478 × 10^-6
    A_Ten= 9.90563 × 10^-7
    17th page
    K = 0.000
    A_Four= -2.06640 × 10^-6
    A₆= 1.19043 × 10^-Five
    A₈= -4.13589 × 10^-7
    A_Ten= 6.77582 × 10^-9
Zoom data (∞)
                   WE ST TE
f (mm)      5.06 12.01 24.29
F_NO                 3.10 4.58 4.91
2ω (°)   80.14 35.47 17.64
d_Four                 0.73 4.49 13.26
d_Ten                10.82 3.67 0.68
d₁₆                 2.75 8.58 9.99
d₁₈                 2.83 3.05 2.97.

Example 2
r₁= 23.279 d₁= 0.80 n_d1= 1.92286 ν_d1= 18.90
r₂= 16.155 d₂= 0.18
r_Three= 17.729 d_Three= 3.05 n_d2= 1.85719 ν_d2= 43.01
r_Four= 577.289 d_Four= (Variable)
r_Five= -57.796 (aspherical surface) d_Five= 0.80 n_d3= 1.83481 ν_d3= 42.71
r₆= 5.963 (aspherical surface) d₆= 2.79
r₇= -136.071 d₇= 1.78 n_d4= 1.94595 ν_d4= 17.98
r₈= -16.198 d₈= 0.09
r₉= -14.697 d₉= 0.68 n_d5= 1.83481 ν_d5= 42.71
r_Ten= -44.810 (Aspherical surface) d_Ten= (Variable)
r₁₁= ∞ (aperture) d₁₁= 0.10
r₁₂= 5.548 (aspherical surface) d₁₂= 2.70 n_d6= 1.58913 ν_d6= 61.14
r₁₃= -10.984 (aspherical surface) d₁₃= 0.10
r₁₄= 5.510 d₁₄= 1.36 n_d7= 1.59201 ν_d7= 67.02
r₁₅= 13.333 d₁₅= 0.80 n_d8= 2.00069 ν_d8= 25.46
r₁₆= 3.476 d₁₆= (Variable)
r₁₇= 19.243 (aspherical surface) d₁₇= 2.07 n_d9= 1.74330 ν_d9= 49.33
r₁₈= -28.285 d₁₈= (Variable)
r₁₉= ∞ d₁₉= 0.40 n_d10= 1.54771 ν_d10= 62.84
r₂₀= ∞ d₂₀= 0.50
r_{twenty one}= ∞ d_{twenty one}= 0.50 n_d11= 1.51633 ν_d11= 64.14
r_{twenty two}= ∞ d_{twenty two}= 0.36
r_{twenty three}= ∞ (image plane)
Aspheric coefficient
    5th page
    K = 0.000
    A_Four= 1.91532 × 10^-Four
    A₆= -6.16585 × 10^-6
    A₈= 9.93129 × 10^-8
    A_Ten= -6.19551 × 10^-Ten
    6th page
    K = 0.000
    A_Four= 8.56780 × 10^-Five
    A₆= 2.37196 × 10^-Five
    A₈= -1.32112 × 10^-6
    A_Ten= 1.29769 × 10^-8
    10th page
    K = 5.360
    A_Four= -2.35672 × 10^-Four
    A₆= -2.32986 × 10^-6
    A₈= 3.46565 × 10^-8
    A_Ten= 0
    12th page
    K = -0.000
    A_Four= -9.12531 × 10^-Four
    A₆= -2.10029 × 10^-6
    A₈= -2.33162 × 10^-6
    A_Ten= 3.38870 × 10^-7
    13th page
    K = 0.000
    A_Four= 5.13813 × 10^-Four
    A₆= 9.30700 × 10^-6
    A₈= -3.76459 × 10^-6
    A_Ten= 5.20840 × 10^-7
    17th page
    K = 0.000
    A_Four= 1.55240 × 10^-Five
    A₆= 1.05486 × 10^-Five
    A₈= -3.44689 × 10^-7
    A_Ten= 5.43477 × 10^-9
Zoom data (∞)
                   WE ST TE
f (mm)      5.06 12.01 24.29
F_NO                 3.11 4.54 4.94
2ω (°)   80.14 35.40 17.62
d_Four                 0.73 4.73 13.26
d_Ten                10.87 3.73 0.66
d₁₆                 2.77 8.48 10.09
d₁₈                 2.86 3.06 2.97.

Example 3
r₁= 24.343 d₁= 0.80 n_d1= 1.92286 ν_d1= 18.90
r₂= 16.189 d₂= 0.16
r_Three= 17.639 d_Three= 3.05 n_d2= 1.88300 ν_d2= 40.76
r_Four= 598.304 d_Four= (Variable)
r_Five= -58.725 (Aspherical surface) d_Five= 0.82 n_d3= 1.88300 ν_d3= 40.76
r₆= 6.041 (Aspherical surface) d₆= 2.60
r₇= 407.018 d₇= 2.01 n_d4= 2.00170 ν_d4= 20.64
r₈= -14.787 d₈= 0.08
r₉= -13.762 d₉= 0.68 n_d5= 1.83481 ν_d5= 42.71
r_Ten= -88.096 (Aspherical surface) d_Ten= (Variable)
r₁₁= ∞ (aperture) d₁₁= 0.10
r₁₂= 5.462 (Aspherical surface) d₁₂= 2.70 n_d6= 1.58913 ν_d6= 61.14
r₁₃= -11.013 (Aspherical surface) d₁₃= 0.10
r₁₄= 5.530 d₁₄= 1.36 n_d7= 1.59201 ν_d7= 67.02
r₁₅= 13.426 d₁₅= 0.80 n_d8= 2.00069 ν_d8= 25.46
r₁₆= 3.443 d₁₆= (Variable)
r₁₇= 19.462 (Aspherical surface) d₁₇= 2.07 n_d9= 1.74330 ν_d9= 49.33
r₁₈= -27.222 d₁₈= (Variable)
r₁₉= ∞ d₁₉= 0.40 n_d10= 1.54771 ν_d10= 62.84
r₂₀= ∞ d₂₀= 0.50
r_{twenty one}= ∞ d_{twenty one}= 0.50 n_d11= 1.51633 ν_d11= 64.14
r_{twenty two}= ∞ d_{twenty two}= 0.36
r_{twenty three}= ∞ (image plane)
Aspheric coefficient
    5th page
    K = 0.000
    A_Four= 1.78466 × 10^-Four
    A₆= -8.17272 × 10^-6
    A₈= 2.01295 × 10^-7
    A_Ten= -1.77746 × 10^-9
    6th page
    K = 0.000
    A_Four= 5.13913 × 10^-Five
    A₆= 2.24397 × 10^-Five
    A₈= -1.94651 × 10^-6
    A_Ten= 5.11678 × 10^-8
    10th page
    K = 11.427
    A_Four= -2.56902 × 10^-Four
    A₆= -1.57604 × 10^-6
    A₈= -1.15551 × 10^-7
    A_Ten= 0
    12th page
    K = -0.000
    A_Four= -9.39293 × 10^-Four
    A₆= -5.83997 × 10^-6
    A₈= -2.22901 × 10^-6
    A_Ten= 3.45022 × 10^-7
    13th page
    K = 0.000
    A_Four= 5.38804 × 10^-Four
    A₆= 3.49744 × 10^-6
    A₈= -2.93189 × 10^-6
    A_Ten= 4.74550 × 10^-7
    17th page
    K = 0.000
    A_Four= 2.27544 × 10^-Five
    A₆= 1.04163 × 10^-Five
    A₈= -3.36814 × 10^-7
    A_Ten= 5.32127 × 10^-9
Zoom data (∞)
                   WE ST TE
f (mm)      5.06 12.01 24.29
F_NO                 3.11 4.62 4.92
2ω (°)   80.16 35.55 17.62
d_Four                 0.73 4.28 13.31
d_Ten                10.93 3.71 0.72
d₁₆                 2.76 8.74 9.98
d₁₈                 2.84 3.04 2.97.

Example 4
r₁= 20.367 d₁= 0.80 n_d1= 1.92286 ν_d1= 18.90
r₂= 15.608 d₂= 0.29
r_Three= 17.741 d_Three= 3.14 n_d2= 1.76802 ν_d2= 49.24
r_Four= 3497.716 d_Four= (Variable)
r_Five= -45.639 (Aspherical surface) d_Five= 0.80 n_d3= 1.83481 ν_d3= 42.71
r₆= 5.950 (aspherical surface) d₆= 2.73
r₇= -255.106 d₇= 1.84 n_d4= 1.92286 ν_d4= 18.90
r₈= -15.843 d₈= 0.68 n_d5= 1.83481 ν_d5= 42.71
r₉= -58.807 (Aspherical surface) d₉= (Variable)
r_Ten= ∞ (aperture) d_Ten= 0.10
r₁₁= 5.586 (Aspherical surface) d₁₁= 2.70 n_d6= 1.58913 ν_d6= 61.14
r₁₂= -11.262 (aspherical surface) d₁₂= 0.10
r₁₃= 5.436 d₁₃= 1.38 n_d7= 1.59201 ν_d7= 67.02
r₁₄= 13.074 d₁₄= 0.80 n_d8= 2.00069 ν_d8= 25.46
r₁₅= 3.469 d₁₅= (Variable)
r₁₆= 19.614 (Aspherical surface) d₁₆= 2.07 n_d9= 1.74330 ν_d9= 49.33
r₁₇= -26.892 d₁₇= (Variable)
r₁₈= ∞ d₁₈= 0.40 n_d10= 1.54771 ν_d10= 62.84
r₁₉= ∞ d₁₉= 0.50
r₂₀= ∞ d₂₀= 0.50 n_d11= 1.51633 ν_d11= 64.14
r_{twenty one}= ∞ d_{twenty one}= 0.36
r_{twenty two}= ∞ (image plane)
Aspheric coefficient
    5th page
    K = 0.000
    A_Four= 2.17672 × 10^-Four
    A₆= -5.32946 × 10^-6
    A₈= 7.95875 × 10^-8
    A_Ten= -5.34232 × 10^-Ten
    6th page
    K = 0.000
    A_Four= 1.20203 × 10^-Four
    A₆= 2.54566 × 10^-Five
    A₈= -1.22695 × 10^-6
    A_Ten= 2.02973 × 10^-8
    9th page
    K = 19.659
    A_Four= -2.47017 × 10^-Four
    A₆= -1.58699 × 10^-6
    A₈= -1.04315 × 10^-7
    A_Ten= 0
    11th page
    K = -0.000
    A_Four= -8.71078 × 10^-Four
    A₆= -4.22508 × 10^-7
    A₈= -1.92565 × 10^-6
    A_Ten= 3.14754 × 10^-7
    12th page
    K = 0.000
    A_Four= 5.15823 × 10^-Four
    A₆= 1.00484 × 10^-Five
    A₈= -2.82400 × 10^-6
    A_Ten= 4.47946 × 10^-7
    16th page
    K = 0.000
    A_Four= 6.80361 × 10^-6
    A₆= 1.09868 × 10^-Five
    A₈= -3.72817 × 10^-7
    A_Ten= 5.90895 × 10^-9
Zoom data (∞)
                   WE ST TE
f (mm)      5.06 12.01 24.29
F_NO                 3.10 4.44 4.93
2ω (°)   80.12 35.18 17.61
d_Four                 0.72 5.37 13.24
d₉                10.83 3.84 0.65
d₁₅                 2.75 8.06 10.08
d₁₇                 2.86 3.05 2.97.

Example 5
r₁= 25.173 d₁= 0.80 n_d1= 1.92286 ν_d1= 18.90
r₂= 16.537 d₂= 0.20
r_Three= 18.252 d_Three= 3.06 n_d2= 1.88300 ν_d2= 40.76
r_Four= -4161.584 d_Four= (Variable)
r_Five= -44.093 (aspherical surface) d_Five= 0.80 n_d3= 1.83481 ν_d3= 42.71
r₆= 6.129 (aspherical surface) d₆= 2.67
r₇= -897.611 d₇= 1.86 n_d4= 1.92286 ν_d4= 18.90
r₈= -16.194 d₈= 0.68 n_d5= 1.83481 ν_d5= 42.71
r₉= -75.584 (aspherical surface) d₉= (Variable)
r_Ten= ∞ (aperture) d_Ten= 0.10
r₁₁= 5.515 (Aspherical surface) d₁₁= 2.70 n_d6= 1.58913 ν_d6= 61.14
r₁₂= -10.975 (aspherical surface) d₁₂= 0.10
r₁₃= 5.494 d₁₃= 1.36 n_d7= 1.59201 ν_d7= 67.02
r₁₄= 12.850 d₁₄= 0.80 n_d8= 2.00069 ν_d8= 25.46
r₁₅= 3.429 d₁₅= (Variable)
r₁₆= 19.614 (Aspherical surface) d₁₆= 2.07 n_d9= 1.74330 ν_d9= 49.33
r₁₇= -27.158 d₁₇= (Variable)
r₁₈= ∞ d₁₈= 0.40 n_d10= 1.54771 ν_d10= 62.84
r₁₉= ∞ d₁₉= 0.50
r₂₀= ∞ d₂₀= 0.50 n_d11= 1.51633 ν_d11= 64.14
r_{twenty one}= ∞ d_{twenty one}= 0.36
r_{twenty two}= ∞ (image plane)
Aspheric coefficient
    5th page
    K = 0.000
    A_Four= 2.01152 × 10^-Four
    A₆= -5.53549 × 10^-6
    A₈= 1.09307 × 10^-7
    A_Ten= -9.22389 × 10^-Ten
    6th page
    K = 0.000
    A_Four= 1.24289 x10^-Four
    A₆= 2.52204 x10^-Five
    A₈= -1.55015 x10^-6
    A_Ten= 3.87174 × 10^-8
    9th page
    K = 15.880
    A_Four= -2.56363 × 10^-Four
    A₆= 3.83459 × 10^-7
    A₈= -1.74921 × 10^-7
    A_Ten= 0
    11th page
    K = -0.000
    A_Four= -9.56239 × 10^-Four
    A₆= -9.52999 × 10^-6
    A₈= -3.92591 × 10^-7
    A_Ten= 1.39818 × 10^-7
    12th page
    K = 0.000
    A_Four= 4.88481 × 10^-Four
    A₆= -6.29539 × 10^-6
    A₈= 4.03797 × 10^-7
    A_Ten= 1.15552 × 10^-7
    16th page
    K = 0.000
    A_Four= 3.74250 × 10^-Five
    A₆= 1.03247 × 10^-Five
    A₈= -3.43630 × 10^-7
    A_Ten= 5.32503 × 10^-9
Zoom data (∞)
                   WE ST TE
f (mm)      5.06 12.01 24.29
F_NO                 3.11 4.48 4.93
2ω (°)   80.15 35.27 17.62
d_Four                 0.72 5.21 13.32
d₉                11.01 3.94 0.73
d₁₅                 2.77 8.18 10.05
d₁₇                 2.83 3.00 2.97.

Example 6
r₁= 23.739 d₁= 0.81 n_d1= 1.94595 ν_d1= 17.98
r₂= 16.355 d₂= 0.21
r_Three= 18.106 d_Three= 3.01 n_d2= 1.88300 ν_d2= 40.76
r_Four= 846.562 d_Four= (Variable)
r_Five= -52.113 (Aspherical surface) d_Five= 0.82 n_d3= 1.88300 ν_d3= 40.76
r₆= 6.190 (Aspherical surface) d₆= 2.65
r₇= -235.098 d₇= 1.86 n_d4= 1.94595 ν_d4= 17.98
r₈= -15.562 d₈= 0.09
r₉= -14.315 d₉= 0.80 n_d5= 1.88300 ν_d5= 40.76
r_Ten= -41.886 (Aspherical surface) d_Ten= (Variable)
r₁₁= ∞ (aperture) d₁₁= 0.10
r₁₂= 5.555 (Aspherical surface) d₁₂= 2.70 n_d6= 1.58913 ν_d6= 61.14
r₁₃= -10.974 (aspherical surface) d₁₃= 0.10
r₁₄= 5.438 d₁₄= 1.38 n_d7= 1.59201 ν_d7= 67.02
r₁₅= 13.503 d₁₅= 0.80 n_d8= 2.00069 ν_d8= 25.46
r₁₆= 3.433 d₁₆= (Variable)
r₁₇= 18.727 (Aspherical surface) d₁₇= 2.07 n_d9= 1.74330 ν_d9= 49.33
r₁₈= -29.343 d₁₈= (Variable)
r₁₉= ∞ d₁₉= 0.40 n_d10= 1.54771 ν_d10= 62.84
r₂₀= ∞ d₂₀= 0.50
r_{twenty one}= ∞ d_{twenty one}= 0.50 n_d11= 1.51633 ν_d11= 64.14
r_{twenty two}= ∞ d_{twenty two}= 0.37
r_{twenty three}= ∞ (image plane)
Aspheric coefficient
    5th page
    K = 0.000
    A_Four= 2.02790 × 10^-Four
    A₆= -6.36728 × 10^-6
    A₈= 1.15320 × 10^-7
    A_Ten= -8.37226 × 10^-Ten
    6th page
    K = 0.000
    A_Four= 8.20642 × 10^-Five
    A₆= 2.47151 × 10^-Five
    A₈= -1.53936 × 10^-6
    A_Ten= 2.64133 × 10^-8
    10th page
    K = 6.008
    A_Four= -2.06900 × 10^-Four
    A₆= -2.13247 × 10^-6
    A₈= 1.58746 × 10^-8
    A_Ten= 0
    12th page
    K = -0.000
    A_Four= -9.21086 × 10^-Four
    A₆= -6.31048 × 10^-6
    A₈= -1.81135 × 10^-6
    A_Ten= 2.67397 × 10^-7
    13th page
    K = 0.000
    A_Four= 4.87773 × 10^-Four
    A₆= 3.10768 × 10^-6
    A₈= -2.75976 × 10^-6
    A_Ten= 3.94656 × 10^-7
    17th page
    K = 0.000
    A_Four= 2.23802 × 10^-Five
    A₆= 1.07437 × 10^-Five
    A₈= -3.48358 × 10^-7
    A_Ten= 5.42112 × 10^-9
Zoom data (∞)
                   WE ST TE
f (mm)      5.06 12.01 24.29
F_NO                 3.12 4.57 4.94
2ω (°)   80.16 35.42 17.62
d_Four                 0.72 4.78 13.23
d_Ten                10.77 3.71 0.66
d₁₆                 2.77 8.47 10.05
d₁₈                 2.85 3.06 2.96.

Example 7
r₁= 23.679 d₁= 0.81 n_d1= 1.94595 ν_d1= 17.98
r₂= 16.309 d₂= 0.20
r_Three= 17.975 d_Three= 3.03 n_d2= 1.88300 ν_d2= 40.76
r_Four= 652.312 d_Four= (Variable)
r_Five= -57.513 (Aspherical surface) d_Five= 0.82 n_d3= 1.88300 ν_d3= 40.76
r₆= 6.169 (aspherical surface) d₆= 2.64
r₇= -172.005 d₇= 1.92 n_d4= 2.10227 ν_d4= 17.10
r₈= -18.412 d₈= 0.11
r₉= -15.586 d₉= 0.80 n_d5= 1.88300 ν_d5= 40.76
r_Ten= -47.805 (aspherical surface) d_Ten= (Variable)
r₁₁= ∞ (aperture) d₁₁= 0.10
r₁₂= 5.447 (Aspherical surface) d₁₂= 2.70 n_d6= 1.58913 ν_d6= 61.14
r₁₃= -10.900 (aspherical surface) d₁₃= 0.10
r₁₄= 5.577 d₁₄= 1.35 n_d7= 1.59201 ν_d7= 67.02
r₁₅= 13.324 d₁₅= 0.80 n_d8= 2.00069 ν_d8= 25.46
r₁₆= 3.452 d₁₆= (Variable)
r₁₇= 19.617 (aspherical surface) d₁₇= 2.07 n_d9= 1.74330 ν_d9= 49.33
r₁₈= -26.823 d₁₈= (Variable)
r₁₉= ∞ d₁₉= 0.40 n_d10= 1.54771 ν_d10= 62.84
r₂₀= ∞ d₂₀= 0.50
r_{twenty one}= ∞ d_{twenty one}= 0.50 n_d11= 1.51633 ν_d11= 64.14
r_{twenty two}= ∞ d_{twenty two}= 0.36
r_{twenty three}= ∞ (image plane)
Aspheric coefficient
    5th page
    K = 0.000
    A_Four= 2.08796 × 10^-Four
    A₆= -7.65961 × 10^-6
    A₈= 1.42959 × 10^-7
    A_Ten= -1.03287 × 10^-9
    6th page
    K = 0.000
    A_Four= 9.25739 × 10^-Five
    A₆= 2.37928 × 10^-Five
    A₈= -1.56581 × 10^-6
    A_Ten= 2.33770 × 10^-8
    10th page
    K = 13.662
    A_Four= -2.04807 × 10^-Four
    A₆= -2.93679 × 10^-6
    A₈= 7.51268 × 10^-8
    A_Ten=
    12th page
    K = -0.000
    A_Four= -9.47047 × 10^-Four
    A₆= -9.73137 × 10^-6
    A₈= -9.44664 × 10^-7
    A_Ten= 2.30496 × 10^-7
    13th page
    K = 0.000
    A_Four= 5.55221 × 10^-Four
    A₆= -3.16660 × 10^-6
    A₈= -3.51784 × 10^-7
    A_Ten= 2.04855 × 10^-7
    17th page
    K = 0.000
    A_Four= 2.11262 × 10^-Five
    A₆= 1.08100 × 10^-Five
    A₈= -3.55468 × 10^-7
    A_Ten= 5.58942 × 10^-9
Zoom data (∞)
                   WE ST TE
f (mm)      5.06 12.01 24.29
F_NO                 3.11 4.57 4.91
2ω (°)   80.18 35.47 17.61
d_Four                 0.72 4.59 13.25
d_Ten                10.75 3.70 0.68
d₁₆                 2.76 8.58 9.98
d₁₈                 2.86 3.06 2.97.

Example 8
r₁= 23.572 d₁= 0.81 n_d1= 1.94595 ν_d1= 17.98
r₂= 16.325 d₂= 0.19
r_Three= 17.924 d_Three= 3.08 n_d2= 1.88300 ν_d2= 40.76
r_Four= 481.040 d_Four= (Variable)
r_Five= -63.672 (Aspherical surface) d_Five= 0.82 n_d3= 1.88300 ν_d3= 40.76
r₆= 6.059 (Aspherical surface) d₆= 2.72
r₇= -238.294 d₇= 1.87 n_d4= 2.10227 ν_d4= 17.10
r₈= -19.462 d₈= 0.80 n_d5= 1.88300 ν_d5= 40.76
r₉= -90.854 (Aspherical surface) d₉= (Variable)
r_Ten= ∞ (aperture) d_Ten= 0.10
r₁₁= 5.548 (aspherical surface) d₁₁= 2.70 n_d6= 1.58913 ν_d6= 61.14
r₁₂= -11.217 (Aspherical surface) d₁₂= 0.10
r₁₃= 5.502 d₁₃= 1.39 n_d7= 1.59201 ν_d7= 67.02
r₁₄= 13.285 d₁₄= 0.80 n_d8= 2.00069 ν_d8= 25.46
r₁₅= 3.476 d₁₅= (Variable)
r₁₆= 19.903 (aspherical surface) d₁₆= 2.07 n_d9= 1.74330 ν_d9= 49.33
r₁₇= -26.017 d₁₇= (Variable)
r₁₈= ∞ d₁₈= 0.40 n_d10= 1.54771 ν_d10= 62.84
r₁₉= ∞ d₁₉= 0.50
r₂₀= ∞ d₂₀= 0.50 n_d11= 1.51633 ν_d11= 64.14
r_{twenty one}= ∞ d_{twenty one}= 0.36
r_{twenty two}= ∞ (image plane)
Aspheric coefficient
    5th page
    K = 0.000
    A_Four= 2.11173 × 10^-Four
    A₆= -8.21005 × 10^-6
    A₈= 1.62208 × 10^-7
    A_Ten= -1.25817 × 10^-9
    6th page
    K = 0.000
    A_Four= 1.55260 × 10^-Four
    A₆= 2.35459 × 10^-Five
    A₈= -1.47843 × 10^-6
    A_Ten= 2.40340 × 10^-8
    9th page
    K = 13.988
    A_Four= -2.46764 × 10^-Four
    A₆= -3.00682 × 10^-6
    A₈= 1.43307 × 10^-8
    A_Ten= 0
    11th page
    K = -0.000
    A_Four= -8.70152 × 10^-Four
    A₆= 2.07452 × 10^-6
    A₈= -2.51898 × 10^-6
    A_Ten= 3.52050 × 10^-7
    12th page
    K = 0.000
    A_Four= 5.43211 × 10^-Four
    A₆= 1.77046 × 10^-Five
    A₈= -4.53251 × 10^-6
    A_Ten= 5.84184 × 10^-7
    16th page
    K = 0.000
    A_Four= 1.55829 × 10^-Five
    A₆= 1.00684 × 10^-Five
    A₈= -3.25292 × 10^-7
    A_Ten= 5.11814 × 10^-9
Zoom data (∞)
                   WE ST TE
f (mm)      5.06 12.01 24.29
F_NO                 3.11 4.51 4.90
2ω (°)   80.16 35.27 17.59
d_Four                 0.72 5.02 13.27
d₉                 10.82 3.84 0.72
d₁₅                 2.75 8.31 9.95
d₁₇                 2.86 3.04 2.97.

Example 9
r₁= 21.524 d₁= 0.80 n_d1= 1.92286 ν_d1= 18.90
r₂= 15.990 d₂= 0.25
r_Three= 18.038 d_Three= 3.04 n_d2= 1.80400 ν_d2= 46.57
r_Four= 1821.002 d_Four= (Variable)
r_Five= -46.956 (Aspherical surface) d_Five= 0.79 n_d3= 1.80610 ν_d3= 40.92
r₆= 5.863 (aspherical surface) d₆= 2.76
r₇= -178.037 d₇= 1.90 n_d4= 1.92286 ν_d4= 18.90
r₈= -14.340 d₈= 0.67 n_d5= 1.80610 ν_d5= 40.92
r₉= -72.767 (aspherical surface) d₉= (Variable)
r_Ten= ∞ (aperture) d_Ten= 0.10
r₁₁= 5.470 (aspherical surface) d₁₁= 2.70 n_d6= 1.58913 ν_d6= 61.14
r₁₂= -11.162 (aspherical surface) d₁₂= 0.10
r₁₃= 5.576 d₁₃= 1.36 n_d7= 1.59201 ν_d7= 67.02
r₁₄= 13.756 d₁₄= 0.80 n_d8= 2.00069 ν_d8= 25.46
r₁₅= 3.493 d₁₅= (Variable)
r₁₆= 19.520 (Aspherical surface) d₁₆= 2.07 n_d9= 1.74330 ν_d9= 49.33
r₁₇= -27.248 d₁₇= (Variable)
r₁₈= ∞ d₁₈= 0.40 n_d10= 1.54771 ν_d10= 62.84
r₁₉= ∞ d₁₉= 0.50
r₂₀= ∞ d₂₀= 0.50 n_d11= 1.51633 ν_d11= 64.14
r_{twenty one}= ∞ d_{twenty one}= 0.36
r_{twenty two}= ∞ (image plane)
Aspheric coefficient
    5th page
    K = 0.000
    A_Four= 2.34682 × 10^-Four
    A₆= -7.08038 × 10^-6
    A₈= 1.25390 × 10^-7
    A_Ten= -9.36786 × 10^-Ten
    6th page
    K = 0.000
    A_Four= 1.52904 × 10^-Four
    A₆= 2.55798 × 10^-Five
    A₈= -1.41637 × 10^-6
    A_Ten= 2.87416 × 10^-8
    9th page
    K = 0.000
    A_Four= -2.74195 × 10^-Four
    A₆= -1.46147 × 10^-6
    A₈= -1.44866 × 10^-7
    A_Ten= 0
    12th page
    K = -0.000
    A_Four= -9.07011 × 10^-Four
    A₆= 6.10900 × 10^-6
    A₈= -3.38866 × 10^-6
    A_Ten= 4.78449 × 10^-7
    13th page
    K = 0.000
    A_Four= 5.63212 × 10^-Four
    A₆= 2.36073 × 10^-Five
    A₈= -6.03623 × 10^-6
    A_Ten= 8.08280 × 10^-7
    17th page
    K = 0.000
    A_Four= 1.27541 × 10^-Five
    A₆= 1.11474 × 10^-Five
    A₈= -3.87618 × 10^-7
    A_Ten= 6.24145 × 10^-9
Zoom data (∞)
                   WE ST TE
f (mm)      5.06 12.01 24.29
F_NO                 3.11 4.45 4.93
2ω (°)   80.13 35.19 17.61
d_Four                 0.72 5.33 13.27
d₉                10.94 3.89 0.69
d₁₅                 2.76 8.08 10.07
d₁₇                 2.86 3.05 2.97.

Example 10
r₁= 21.929 d₁= 0.81 n_d1= 1.94595 ν_d1= 17.98
r₂= 15.886 d₂= 3.02 n_d2= 1.83481 ν_d2= 42.71
r_Three= 87.110 d_Three= (Variable)
r_Four= -603.712 (aspherical surface) d_Four= 0.82 n_d3= 1.88300 ν_d3= 40.76
r_Five= 5.962 (aspherical surface) d_Five= 2.72
r₆= 108.526 d₆= 1.76 n_d4= 2.10227 ν_d4= 17.10
r₇= -23.243 d₇= 0.16
r₈= -17.863 d₈= 0.80 n_d5= 1.88300 ν_d5= 40.76
r₉= -201.302 (Aspherical surface) d₉= (Variable)
r_Ten= Aperture d_Ten= 0.10
r₁₁= 5.737 (aspherical surface) d₁₁= 2.70 n_d6= 1.58913 ν_d6= 61.14
r₁₂= -10.526 (Aspherical surface) d₁₂= 0.10
r₁₃= 5.184 d₁₃= 1.42 n_d7= 1.59201 ν_d7= 67.02
r₁₄= 12.685 d₁₄= 0.80 n_d8= 2.00069 ν_d8= 25.46
r₁₅= 3.389 d₁₅= (Variable)
r₁₆= 28.421 (aspherical surface) d₁₆= 2.07 n_d9= 1.74330 ν_d9= 49.33
r₁₇= -19.743 d₁₇= (Variable)
r₁₈= ∞ d₁₈= 0.40 n_d10= 1.54771 ν_d10= 62.84
r₁₉= ∞ d₁₉= 0.50
r₂₀= ∞ d₂₀= 0.50 n_d11= 1.51633 ν_d11= 64.14
r_{twenty one}= ∞ d_{twenty one}= 0.35
r_{twenty two}= ∞ (image plane)
Aspheric coefficient
    4th page
    K = 0.000
    A_Four= 1.17638 × 10^-Four
    A₆= -1.87398 × 10^-6
    A₈= -1.21415 × 10^-8
    A_Ten= 3.25687 × 10^-Ten
    5th page
    K = 0.000
    A_Four= 9.74365 × 10^-Five
    A₆= 1.86507 × 10^-Five
    A₈= -6.27883 × 10^-7
    A_Ten= -6.71787 × 10^-9
    9th page
    K = 300.320
    A_Four= -2.68737 × 10^-Four
    A₆= -2.18216 × 10^-8
    A₈= -4.79877 × 10^-8
    A_Ten= 0
    11th page
    K = -0.000
    A_Four= -9.41932 × 10^-Four
    A₆= -1.82332 × 10^-Five
    A₈= -9.47875 × 10^-7
    A_Ten= 1.96272 × 10^-7
    12th page
    K = 0.000
    A_Four= 4.34113 × 10^-Four
    A₆= -1.86904 × 10^-Five
    A₈= -3.97394 × 10^-7
    A_Ten= 1.70317 × 10^-7
    16th page
    K = 0.000
    A_Four= 2.98825 × 10^-Five
    A₆= 7.00636 × 10^-6
    A₈= -2.06857 × 10^-7
    A_Ten= 3.08660 × 10^-9
Zoom data (∞)
                   WE ST TE
f (mm)      5.06 12.01 24.29
F_NO                 3.03 4.93 4.99
2ω (°)   80.21 36.18 17.76
d_Three                 0.74 0.99 13.31
d₉                11.18 3.27 0.89
d₁₅                 2.71 9.95 10.21
d₁₇                 2.64 2.99 2.99.

Example 11
r₁= 19.964 d₁= 0.80 n_d1= 1.92286 ν_d1= 18.90
r₂= 15.354 d₂= 0.22
r_Three= 16.981 d_Three= 3.10 n_d2= 1.76802 ν_d2= 49.24
r_Four= 321.532 d_Four= (Variable)
r_Five= -79.400 (aspherical surface) d_Five= 0.82 n_d3= 1.88300 ν_d3= 40.76
r₆= 6.026 (Aspherical surface) d₆= 2.65
r₇= -512.296 d₇= 2.00 n_d4= 2.00170 ν_d4= 20.64
r₈= -14.190 d₈= 0.13
r₉= -10.837 (Aspherical surface) d₉= 0.67 n_d5= 1.81600 ν_d5= 46.62
r_Ten= -38.820 d_Ten= (Variable)
r₁₁= ∞ (aperture) d₁₁= 0.10
r₁₂= 5.567 (aspherical surface) d₁₂= 2.70 n_d6= 1.58913 ν_d6= 61.14
r₁₃= -10.835 (aspherical surface) d₁₃= 0.10
r₁₄= 5.426 d₁₄= 1.39 n_d7= 1.59201 ν_d7= 67.02
r₁₅= 13.374 d₁₅= 0.80 n_d8= 2.00069 ν_d8= 25.46
r₁₆= 3.434 d₁₆= (Variable)
r₁₇= 21.181 (aspherical surface) d₁₇= 2.07 n_d9= 1.74330 ν_d9= 49.33
r₁₈= -23.592 d₁₈= (Variable)
r₁₉= ∞ d₁₉= 0.40 n_d10= 1.54771 ν_d10= 62.84
r₂₀= ∞ d₂₀= 0.50
r_{twenty one}= ∞ d_{twenty one}= 0.50 n_d11= 1.51633 ν_d11= 64.14
r_{twenty two}= ∞ d_{twenty two}= 0.36
r_{twenty three}= ∞ (image plane)
Aspheric coefficient
    5th page
    K = 0.000
    A_Four= 1.81913 × 10^-Four
    A₆= -7.45514 × 10^-6
    A₈= 1.16696 × 10^-7
    A_Ten= -6.24258 × 10^-Ten
    6th page
    K = 0.000
    A_Four= 3.02384 × 10^-Five
    A₆= 2.11070 × 10^-Five
    A₈= -1.27196 × 10^-6
    A_Ten= 4.98377 × 10^-9
    9th page
    K = -0.063
    A_Four= 2.66985 × 10^-Four
    A₆= 5.08873 × 10^-6
    A₈= -1.46937 × 10^-7
    A_Ten= 0
    12th page
    K = -0.000
    A_Four= -9.20807 × 10^-Four
    A₆= -4.91248 × 10^-6
    A₈= -3.02284 × 10^-6
    A_Ten= 3.84485 × 10^-7
    13th page
    K = 0.000
    A_Four= 5.02906 × 10^-Four
    A₆= 7.33058 × 10^-6
    A₈= -5.38763 × 10^-6
    A_Ten= 6.41876 × 10^-7
    17th page
    K = 0.000
    A_Four= 2.80646 × 10^-6
    A₆= 1.03678 × 10^-Five
    A₈= -3.21345 × 10^-7
    A_Ten= 4.86255 × 10^-9
Zoom data (∞)
                   WE ST TE
f (mm)      5.06 12.01 24.29
F_NO                 3.09 4.69 4.91
2ω (°)   80.15 35.68 17.65
d_Four                 0.73 3.65 13.26
d_Ten                10.76 3.56 0.77
d₁₆                 2.74 9.08 10.01
d₁₈                 2.81 3.04 2.97.

Example 12
r₁= 20.035 d₁= 0.80 n_d1= 1.92286 ν_d1= 18.90
r₂= 15.388 d₂= 0.21
r_Three= 16.987 d_Three= 3.10 n_d2= 1.76802 ν_d2= 49.24
r_Four= 322.739 d_Four= (Variable)
r_Five= -67.042 (Aspherical surface) d_Five= 0.82 n_d3= 1.88300 ν_d3= 40.76
r₆= 6.104 (Aspherical surface) d₆= 2.63
r₇= -553.055 d₇= 2.02 n_d4= 2.00170 ν_d4= 20.64
r₈= -14.110 d₈= 0.17
r₉= -11.468 (Aspherical surface) d₉= 0.67 n_d5= 1.81600 ν_d5= 46.62
r_Ten= -48.428 (Aspherical surface) d_Ten= (Variable)
r₁₁= ∞ (aperture) d₁₁= 0.10
r₁₂= 5.592 (aspherical surface) d₁₂= 2.70 n_d6= 1.58913 ν_d6= 61.14
r₁₃= -10.777 (aspherical surface) d₁₃= 0.10
r₁₄= 5.381 d₁₄= 1.39 n_d7= 1.59201 ν_d7= 67.02
r₁₅= 13.633 d₁₅= 0.80 n_d8= 2.00069 ν_d8= 25.46
r₁₆= 3.428 d₁₆= (Variable)
r₁₇= 21.377 (aspherical surface) d₁₇= 2.07 n_d9= 1.74330 ν_d9= 49.33
r₁₈= -23.467 d₁₈= (Variable)
r₁₉= ∞ d₁₉= 0.40 n_d10= 1.54771 ν_d10= 62.84
r₂₀= ∞ d₂₀= 0.50
r_{twenty one}= ∞ d_{twenty one}= 0.50 n_d11= 1.51633 ν_d11= 64.14
r_{twenty two}= ∞ d_{twenty two}= 0.36
r_{twenty three}= ∞ (image plane)
Aspheric coefficient
    5th page
    K = 0.000
    A_Four= 2.02227 × 10^-Four
    A₆= -8.03922 × 10^-6
    A₈= 1.51641 × 10^-7
    A_Ten= -1.06462 × 10^-9
    6th page
    K = 0.000
    A_Four= 3.98938 × 10^-Five
    A₆= 1.96692 × 10^-Five
    A₈= -1.68354 × 10^-6
    A_Ten= 2.76679 × 10^-8
    9th page
    K = -0.063
    A_Four= 2.07247 × 10^-Five
    A₆= -3.77371 × 10^-6
    A₈= 2.63786 × 10^-7
    A_Ten= 0
    10th page
    K = -0.897
    A_Four= -2.19314 × 10^-Four
    A₆= -5.31018 × 10^-6
    A₈= 3.15789 × 10^-7
    A_Ten= 0
    12th page
    K = -0.000
    A_Four= -9.35871 × 10^-Four
    A₆= -1.13973 × 10^-Five
    A₈= -7.24228 × 10^-7
    A_Ten= 1.19444 × 10^-7
    13th page
    K = 0.000
    A_Four= 4.83658 × 10^-Four
    A₆= -9.01954 × 10^-6
    A₈= 1.55326 × 10^-7
    A_Ten= 4.11169 × 10^-8
    17th page
    K = 0.000
    A_Four= 8.51281 × 10^-6
    A₆= 9.83773 × 10^-6
    A₈= -3.17684 × 10^-7
    A_Ten= 5.22025 × 10^-9
Zoom data (∞)
                   WE ST TE
f (mm)      5.06 12.01 24.29
F_NO                 3.09 4.69 4.92
2ω (°)   80.14 35.67 17.64
d_Four                 0.73 3.64 13.26
d_Ten                10.77 3.56 0.77
d₁₆                 2.74 9.08 10.02
d₁₈                 2.80 3.03 2.97.

Example 13
r₁= 24.847 d₁= 0.80 n_d1= 1.94595 ν_d1= 17.98
r₂= 16.542 d₂= 0.29
r_Three= 18.208 d_Three= 3.02 n_d2= 1.88300 ν_d2= 40.76
r_Four= 3582.698 d_Four= (Variable)
r_Five= -43.179 (aspherical surface) d_Five= 0.79 n_d3= 1.80610 ν_d3= 40.92
r₆= 5.891 (aspherical surface) d₆= 2.64
r₇= -157590.062 d₇= 1.91 n_d4= 1.94595 ν_d4= 17.98
r₈= -15.395 d₈= 0.67 n_d5= 1.80610 ν_d5= 40.92
r₉= -175.340 (aspherical surface) d₉= (Variable)
r_Ten= ∞ (aperture) d_Ten= 0.10
r₁₁= 5.417 (aspherical surface) d₁₁= 2.70 n_d6= 1.58913 ν_d6= 61.14
r₁₂= -10.144 (aspherical surface) d₁₂= (Variable)
r₁₃= 5.942 d₁₃= 1.42 n_d7= 1.59201 ν_d7= 67.02
r₁₄= 24.078 d₁₄= 0.80 n_d8= 2.00069 ν_d8= 25.46
r₁₅= 3.618 d₁₅= (Variable)
r₁₆= 17.723 (aspherical surface) d₁₆= 2.07 n_d9= 1.74330 ν_d9= 49.33
r₁₇= -30.024 d₁₇= (Variable)
r₁₈= ∞ d₁₈= 0.40 n_d10= 1.54771 ν_d10= 62.84
r₁₉= ∞ d₁₉= 0.50
r₂₀= ∞ d₂₀= 0.50 n_d11= 1.51633 ν_d11= 64.14
r_{twenty one}= ∞ d_{twenty one}= 0.36
r_{twenty two}= ∞ (image plane)
Aspheric coefficient
    5th page
    K = 0.000
    A_Four= 2.41650 × 10^-Four
    A₆= -7.80486 × 10^-6
    A₈= 1.53963 × 10^-7
    A_Ten= -1.21087 × 10^-9
    6th page
    K = 0.000
    A_Four= 1.85981 × 10^-Four
    A₆= 2.55754 × 10^-Five
    A₈= -1.92596 × 10^-6
    A_Ten= 3.81224 × 10^-8
    9th page
    K = -4.077
    A_Four= -3.33609 × 10^-Four
    A₆= 6.19746 × 10^-6
    A₈= -2.40693 × 10^-7
    A_Ten= 4.21649 × 10^-Ten
    11th page
    K = -0.000
    A_Four= -1.00640 × 10^-3
    A₆= 2.89626 × 10^-Five
    A₈= -5.10096 × 10^-6
    A_Ten= 7.01287 × 10^-7
    12th page
    K = 0.000
    A_Four= 6.92460 × 10^-Four
    A₆= 4.80286 × 10^-Five
    A₈= -9.42465 × 10^-6
    A_Ten= 1.22823 × 10^-6
    16th page
    K = 0.000
    A_Four= 3.67077 × 10^-Five
    A₆= 1.07760 × 10^-Five
    A₈= -3.84914 × 10^-7
    A_Ten= 6.38037 × 10^-9
Zoom data (∞)
                   WE ST TE
f (mm)      5.06 12.00 24.28
F_NO                 3.23 4.54 5.07
2ω (°)   80.19 35.07 17.60
d_Four                 0.71 5.09 13.51
d₉                10.96 3.46 0.85
d₁₂                 0.20 0.57 0.40
d₁₅                 2.75 7.12 9.46
d₁₇                 2.80 2.94 2.96.

Example 14
r₁= 19.959 d₁= 0.80 n_d1= 1.92286 ν_d1= 18.90
r₂= 15.153 d₂= 0.19
r_Three= 16.567 d_Three= 3.19 n_d2= 1.76802 ν_d2= 49.24
r_Four= 328.834 d_Four= (Variable)
r_Five= -66.705 (Aspherical surface) d_Five= 0.82 n_d3= 1.88300 ν_d3= 40.76
r₆= 6.014 (Aspherical surface) d₆= 2.67
r₇= -97.974 d₇= 1.95 n_d4= 2.00170 ν_d4= 20.64
r₈= -12.905 d₈= 0.12
r₉= -10.476 (aspherical surface) d₉= 0.67 n_d5= 1.81600 ν_d5= 46.62
r_Ten= -36.471 d_Ten= (Variable)
r₁₁= ∞ (aperture) d₁₁= 0.10
r₁₂= 5.598 (Aspherical surface) d₁₂= 2.70 n_d6= 1.58913 ν_d6= 61.14
r₁₃= -10.200 (aspherical surface) d₁₃= (Variable)
r₁₄= 5.893 d₁₄= 1.42 n_d7= 1.59201 ν_d7= 67.02
r₁₅= 20.687 d₁₅= 0.80 n_d8= 2.00069 ν_d8= 25.46
r₁₆= 3.680 d₁₆= (Variable)
r₁₇= 18.589 (Aspherical surface) d₁₇= 2.07 n_d9= 1.74330 ν_d9= 49.33
r₁₈= -26.724 d₁₈= (Variable)
r₁₉= ∞ d₁₉= 0.40 n_d10= 1.54771 ν_d10= 62.84
r₂₀= ∞ d₂₀= 0.50
r_{twenty one}= ∞ d_{twenty one}= 0.50 n_d11= 1.51633 ν_d11= 64.14
r_{twenty two}= ∞ d_{twenty two}= 0.36
r_{twenty three}= ∞ (image plane)
Aspheric coefficient
    5th page
    K = 0.000
    A_Four= 1.92323 × 10^-Four
    A₆= -4.86162 × 10^-6
    A₈= 5.55922 × 10^-8
    A_Ten= -2.22548 × 10^-Ten
    6th page
    K = 0.000
    A_Four= 9.52228 × 10^-Five
    A₆= 2.45561 × 10^-Five
    A₈= -1.19859 × 10^-6
    A_Ten= 6.02161 × 10^-9
    9th page
    K = 0.020
    A_Four= 3.06753 × 10^-Four
    A₆= -6.37184 × 10^-7
    A₈= 2.66117 × 10^-8
    A_Ten= 0
    12th page
    K = -0.000
    A_Four= -9.26843 × 10^-Four
    A₆= 3.04592 × 10^-Five
    A₈= -6.90151 × 10^-6
    A_Ten= 7.46676 × 10^-7
    13th page
    K = 0.000
    A_Four= 6.28294 × 10^-Four
    A₆= 5.21648 × 10^-Five
    A₈= -1.31953 × 10^-Five
    A_Ten= 1.46113 × 10^-6
    17th page
    K = 0.000
    A_Four= -6.81284 × 10^-6
    A₆= 1.02822 × 10^-Five
    A₈= -3.09403 × 10^-7
    A_Ten= 4.47496 × 10^-9
Zoom data (∞)
                   WE ST TE
f (mm)      5.06 12.01 24.29
F_NO                 3.13 4.50 4.92
2ω (°)   80.23 35.24 17.60
d_Four                 0.72 4.62 13.21
d_Ten                10.56 3.30 0.78
d₁₃                 0.23 0.57 0.43
d₁₆                 2.76 7.67 9.68
d₁₈                 2.86 3.00 2.96.

Example 15
r₁= 25.601 d₁= 0.80 n_d1= 1.92286 ν_d1= 18.90
r₂= 16.493 d₂= 0.20
r_Three= 18.075 d_Three= 3.23 n_d2= 1.88300 ν_d2= 40.76
r_Four= -1234.242 d_Four= (Variable)
r_Five= -40.268 (aspherical surface) d_Five= 0.80 n_d3= 1.83481 ν_d3= 42.71
r₆= 6.022 (Aspherical surface) d₆= 2.62
r₇= -407.214 d₇= 1.83 n_d4= 1.92286 ν_d4= 18.90
r₈= -15.866 d₈= 0.68 n_d5= 1.83481 ν_d5= 42.71
r₉= -66.674 (Aspherical surface) d₉= (Variable)
r_Ten= ∞ (aperture) d_Ten= 0.10
r₁₁= 5.520 (aspherical surface) d₁₁= 2.70 n_d6= 1.58913 ν_d6= 61.14
r₁₂= -9.949 (aspherical surface) d₁₂= (Variable)
r₁₃= 6.163 d₁₃= 1.35 n_d7= 1.59201 ν_d7= 67.02
r₁₄= 18.256 d₁₄= 0.80 n_d8= 2.00069 ν_d8= 25.46
r₁₅= 3.675 d₁₅= (Variable)
r₁₆= 15.963 (aspherical surface) d₁₆= 2.07 n_d9= 1.74330 ν_d9= 49.33
r₁₇= -38.145 d₁₇= (Variable)
r₁₈= ∞ d₁₈= 0.40 n_d10= 1.54771 ν_d10= 62.84
r₁₉= ∞ d₁₉= 0.50
r₂₀= ∞ d₂₀= 0.50 n_d11= 1.51633 ν_d11= 64.14
r_{twenty one}= ∞ d_{twenty one}= 0.37
r_{twenty two}= ∞ (image plane)
Aspheric coefficient
    5th page
    K = 0.000
    A_Four= 2.05163 × 10^-Four
    A₆= -3.37326 × 10^-6
    A₈= 4.45283 × 10^-8
    A_Ten= -3.62203 × 10^-Ten
    6th page
    K = 0.000
    A_Four= 1.47479 × 10^-Four
    A₆= 2.72737 × 10^-Five
    A₈= -1.43607 × 10^-6
    A_Ten= 3.29097 × 10^-8
    9th page
    K = 17.341
    A_Four= -2.82382 × 10^-Four
    A₆= 3.16842 × 10^-6
    A₈= -2.28861 × 10^-7
    A_Ten= 0
    11th page
    K = -0.000
    A_Four= -1.03741 × 10^-3
    A₆= 2.15062 × 10^-Five
    A₈= -6.81878 × 10^-6
    A_Ten= 7.72131 × 10^-7
    12th page
    K = 0.000
    A_Four= 5.90361 × 10^-Four
    A₆= 4.12917 × 10^-Five
    A₈= -1.28212 × 10^-Five
    A_Ten= 1.50309 × 10^-6
    16th page
    K = 0.000
    A_Four= 2.50156 × 10^-Five
    A₆= 1.12904 × 10^-Five
    A₈= -3.91013 × 10^-7
    A_Ten= 6.07074 × 10^-9
Zoom data (∞)
                   WE ST TE
f (mm)      5.06 12.00 24.29
F_NO                 3.13 4.24 4.94
2ω (°)   80.27 34.68 17.58
d_Four                 0.71 6.26 13.33
d₉                10.81 3.63 0.72
d₁₂                 0.27 0.57 0.42
d₁₅                 2.76 6.65 9.78
d₁₇                 2.83 3.00 2.96.

Example 16
r₁= 21.193 d₁= 0.81 n_d1= 1.94595 ν_d1= 17.98
r₂= 15.192 d₂= 3.09 n_d2= 1.83481 ν_d2= 42.71
r_Three= 81.748 d_Three= (Variable)
r_Four= -603.712 (aspherical surface) d_Four= 0.82 n_d3= 1.88300 ν_d3= 40.76
r_Five= 5.982 (aspherical surface) d_Five= 2.78
r₆= -237.176 d₆= 1.71 n_d4= 2.10227 ν_d4= 17.10
r₇= -18.101 d₇= 0.09
r₈= -15.997 d₈= 0.80 n_d5= 1.88300 ν_d5= 40.76
r₉= -168.381 (aspherical surface) d₉= (Variable)
r_Ten= ∞ (aperture) d_Ten= 0.10
r₁₁= 5.812 (Aspherical surface) d₁₁= 2.70 n_d6= 1.58913 ν_d6= 61.14
r₁₂= -10.295 (Aspherical surface) d₁₂= (Variable)
r₁₃= 5.387 d₁₃= 1.54 n_d7= 1.59201 ν_d7= 67.02
r₁₄= 19.283 d₁₄= 0.80 n_d8= 2.00069 ν_d8= 25.46
r₁₅= 3.554 d₁₅= (Variable)
r₁₆= 24.991 (aspherical surface) d₁₆= 2.07 n_d9= 1.74330 ν_d9= 49.33
r₁₇= -19.483 d₁₇= (Variable)
r₁₈= ∞ d₁₈= 0.40 n_d10= 1.54771 ν_d10= 62.84
r₁₉= ∞ d₁₉= 0.50
r₂₀= ∞ d₂₀= 0.50 n_d11= 1.51633 ν_d11= 64.14
r_{twenty one}= ∞ d_{twenty one}= 0.35
r_{twenty two}= ∞ (image plane)
Aspheric coefficient
    4th page
    K = 0.000
    A_Four= 1.21970 × 10^-Four
    A₆= -1.08084 × 10^-6
    A₈= -1.14600 × 10^-8
    A_Ten= 1.97222 × 10^-Ten
    5th page
    K = 0.000
    A_Four= 1.75555 × 10^-Four
    A₆= 2.16172 × 10^-Five
    A₈= -8.70023 × 10^-7
    A_Ten= 1.24313 × 10^-8
    9th page
    K = 410.383
    A_Four= -2.79644 × 10^-Four
    A₆= 4.80703 × 10^-6
    A₈= -2.06609 × 10^-7
    A_Ten= 0
    11th page
    K = -0.000
    A_Four= -8.72572 × 10^-Four
    A₆= 1.99478 × 10^-Five
    A₈= -4.51334 × 10^-6
    A_Ten= 5.24324 × 10^-7
    12th page
    K = 0.000
    A_Four= 5.50797 × 10^-Four
    A₆= 2.74834 × 10^-Five
    A₈= -6.52190 × 10^-6
    A_Ten= 7.69571 × 10^-7
    16th page
    K = 0.000
    A_Four= 1.78974 × 10^-Five
    A₆= 7.85039 × 10^-6
    A₈= -2.65852 × 10^-7
    A_Ten= 4.28825 × 10^-9
Zoom data (∞)
                   WE ST TE
f (mm)      5.06 12.01 24.29
F_NO                 3.08 4.93 4.91
2ω (°)   80.33 36.11 17.66
d_Three                 0.74 1.00 13.34
d₉                10.94 3.05 0.89
d₁₂                 0.16 0.57 0.55
d₁₅                 2.75 9.30 9.26
d₁₇                 2.70 3.00 2.99.

Example 17
r₁= 24.005 d₁= 0.80 n_d1= 1.92286 ν_d1= 18.90
r₂= 15.730 d₂= 0.18
r_Three= 16.798 d_Three= 3.12 n_d2= 1.88300 ν_d2= 40.76
r_Four= 320.063 d_Four= (Variable)
r_Five= -63.961 (Aspherical surface) d_Five= 0.80 n_d3= 1.83481 ν_d3= 42.71
r₆= 5.769 (aspherical surface) d₆= 2.79
r₇= -110.876 d₇= 1.74 n_d4= 1.94595 ν_d4= 17.98
r₈= -15.935 d₈= 0.08
r₉= -14.478 d₉= 0.68 n_d5= 1.83481 ν_d5= 42.71
r_Ten= -43.168 (Aspherical surface) d_Ten= (Variable)
r₁₁= ∞ (aperture) d₁₁= 0.10
r₁₂= 5.627 (Aspherical surface) d₁₂= 2.70 n_d6= 1.58913 ν_d6= 61.14
r₁₃= -9.958 (Aspherical surface) d₁₃= (Variable)
r₁₄= 6.057 d₁₄= 1.36 n_d7= 1.59201 ν_d7= 67.02
r₁₅= 18.994 d₁₅= 0.80 n_d8= 2.00069 ν_d8= 25.46
r₁₆= 3.702 d₁₆= (Variable)
r₁₇= 16.931 (aspherical surface) d₁₇= 2.07 n_d9= 1.74330 ν_d9= 49.33
r₁₈= -33.088 d₁₈= (Variable)
r₁₉= ∞ d₁₉= 0.40 n_d10= 1.54771 ν_d10= 62.84
r₂₀= ∞ d₂₀= 0.50
r_{twenty one}= ∞ d_{twenty one}= 0.50 n_d11= 1.51633 ν_d11= 64.14
r_{twenty two}= ∞ d_{twenty two}= 0.37
r_{twenty three}= ∞ (image plane)
Aspheric coefficient
    5th page
    K = 0.000
    A_Four= 2.20322 × 10^-Four
    A₆= -8.05410 × 10^-6
    A₈= 1.50663 × 10^-7
    A_Ten= -1.08544 × 10^-9
    6th page
    K = 0.000
    A_Four= 1.19766 × 10^-Four
    A₆= 2.71353 × 10^-Five
    A₈= -1.79261 × 10^-6
    A_Ten= 2.50985 × 10^-8
    10th page
    K = 4.763
    A_Four= -2.60503 × 10^-Four
    A₆= -1.23050 × 10^-6
    A₈= 2.35967 × 10^-8
    A_Ten= 0
    12th page
    K = -0.000
    A_Four= -9.80569 × 10^-Four
    A₆= 1.94848 × 10^-Five
    A₈= -5.98539 × 10^-6
    A_Ten= 6.24092 × 10^-7
    13th page
    K = 0.000
    A_Four= 5.74317 × 10^-Four
    A₆= 3.99276 × 10^-Five
    A₈= -1.14945 × 10^-Five
    A_Ten= 1.22736 × 10^-6
    17th page
    K = 0.000
    A_Four= 8.72792 × 10^-7
    A₆= 1.10477 × 10^-Five
    A₈= -3.58880 × 10^-7
    A_Ten= 5.71191 × 10^-9
Zoom data (∞)
                   WE ST TE
f (mm)      5.06 12.01 24.29
F_NO                 3.14 4.56 4.90
2ω (°)   80.18 35.40 17.59
d_Four                 0.73 4.26 13.29
d_Ten                10.70 3.25 0.68
d₁₃                 0.29 0.58 0.46
d₁₆                 2.76 7.98 9.63
d₁₈                 2.86 3.05 2.96.

Example 18
r₁= 17.636 (Aspherical surface) d₁= 3.46 n_d1= 1.49700 ν_d1= 81.54
r₂= 1651.373 (aspherical surface) d₂= (Variable)
r_Three= -89.845 (Aspherical surface) d_Three= 0.82 n_d2= 1.88300 ν_d2= 40.76
r_Four= 6.252 (Aspherical surface) d_Four= 2.41
r_Five= 36.538 d_Five= 2.14 n_d3= 1.94595 ν_d3= 17.98
r₆= -20.686 d₆= 0.20
r₇= -15.473 d₇= 0.70 n_d4= 1.88300 ν_d4= 40.76
r₈= -705.490 (aspherical surface) d₈= (Variable)
r₉= ∞ (aperture) d₉= 0.10
r_Ten= 5.371 (aspherical surface) d_Ten= 2.70 n_d5= 1.58913 ν_d5= 61.14
r₁₁= -12.630 (aspherical surface) d₁₁= 0.10
r₁₂= 4.840 d₁₂= 1.30 n_d6= 1.59201 ν_d6= 67.02
r₁₃= 8.993 d₁₃= 0.80 n_d7= 2.00170 ν_d7= 20.64
r₁₄= 3.169 d₁₄= (Variable)
r₁₅= -175.389 (Aspherical surface) d₁₅= 2.05 n_d8= 2.00170 ν_d8= 20.64
r₁₆= -15.339 d₁₆= (Variable)
r₁₇= ∞ d₁₇= 0.40 n_d9= 1.54771 ν_d9= 62.84
r₁₈= ∞ d₁₈= 0.50
r₁₉= ∞ d₁₉= 0.50 n_d10= 1.51633 ν_d10= 64.14
r₂₀= ∞ d₂₀= 0.36
r_{twenty one}= ∞ (image plane)
Aspheric coefficient
    First side
    K = -0.000
    A_Four= -9.36696 × 10^{-twenty one}
    A₆= -3.07965 × 10^-7
    A₈= 1.40121 × 10^-9
    A_Ten= 8.27669 × 10^-11
    Second side
    K = -0.000
    A_Four= 1.06767 × 10^-Five
    A₆= -7.16715 × 10^-7
    A₈= 1.70324 × 10^-8
    A_Ten= -3.34505 × 10^-11
    Third side
    K = 0.000
    A_Four= 4.52338 × 10^-Five
    A₆= 1.74362 × 10^-6
    A₈= -8.20880 × 10^-8
    A_Ten= 1.09382 × 10^-9
    4th page
    K = 0.000
    A_Four= -5.26435 × 10^-Five
    A₆= 9.38403 × 10^-6
    A₈= -4.26308 × 10^-7
    A_Ten= 1.16873 × 10^-8
    8th page
    K = -3.680
    A_Four= -2.58689 × 10^-Four
    A₆= 7.09681 × 10^-6
    A₈= -7.55479 × 10^-7
    A_Ten= 1.66474 × 10^-8
    10th page
    K = -0.000
    A_Four= -8.26225 × 10^-Four
    A₆= 2.42650 × 10^-Five
    A₈= -2.03186 × 10^-6
    A_Ten= 2.44772 × 10^-7
    11th page
    K = 0.000
    A_Four= 6.51537 × 10^-Four
    A₆= 4.56976 × 10^-Five
    A₈= -3.58200 × 10^-6
    A_Ten= 4.02796 × 10^-7
    15th page
    K = 0.000
    A_Four= 8.11366 × 10^-Five
    A₆= 1.01901 × 10^-Five
    A₈= -3.84282 × 10^-7
    A_Ten= 5.33610 × 10^-9
Zoom data (∞)
                   WE ST TE
f (mm)      5.06 11.98 24.29
F_NO                 3.03 4.41 5.05
2ω (°)   81.54 36.13 18.37
d₂                 0.72 4.69 12.81
d₈                11.55 4.15 0.93
d₁₄                 2.78 7.77 10.07
d₁₆                 2.78 2.99 3.33.

Example 19
r₁= 15.057 (aspherical surface) d₁= 3.36 n_d1= 1.43875 ν_d1= 94.93
r₂= 16740.605 (aspherical surface) d₂= (Variable)
r_Three= -109.482 (aspherical surface) d_Three= 0.82 n_d2= 1.88300 ν_d2= 40.76
r_Four= 5.865 (aspherical surface) d_Four= 2.48
r_Five= 29.434 d_Five= 2.25 n_d3= 1.94595 ν_d3= 17.98
r₆= -21.699 d₆= 0.26
r₇= -15.455 d₇= 0.70 n_d4= 1.88300 ν_d4= 40.76
r₈= 61494.611 (Aspherical surface) d₈= (Variable)
r₉= ∞ (aperture) d₉= 0.10
r_Ten= 5.519 (Aspherical surface) d_Ten= 2.70 n_d5= 1.58913 ν_d5= 61.14
r₁₁= -12.178 (Aspherical surface) d₁₁= 0.10
r₁₂= 4.874 d₁₂= 1.36 n_d6= 1.59201 ν_d6= 67.02
r₁₃= 9.784 d₁₃= 0.80 n_d7= 2.00170 ν_d7= 20.64
r₁₄= 3.227 d₁₄= (Variable)
r₁₅= -455.052 (aspherical surface) d₁₅= 2.04 n_d8= 2.00170 ν_d8= 20.64
r₁₆= -15.796 d₁₆= (Variable)
r₁₇= ∞ d₁₇= 0.40 n_d9= 1.54771 ν_d9= 62.84
r₁₈= ∞ d₁₈= 0.50
r₁₉= ∞ d₁₉= 0.50 n_d10= 1.51633 ν_d10= 64.14
r₂₀= ∞ d₂₀= 0.36
r_{twenty one}= ∞ (image plane)
Aspheric coefficient
    First side
    K = -0.000
    A_Four= -9.36696 × 10^{-twenty one}
    A₆= -2.82322 × 10^-7
    A₈= -3.32314 × 10^-9
    A_Ten= 9.80939 × 10^-11
    Second side
    K = -0.000
    A_Four= 2.03046 × 10^-Five
    A₆= -8.63339 × 10^-7
    A₈= 1.39119 × 10^-8
    A_Ten= -2.72606 × 10^-11
    Third side
    K = 0.000
    A_Four= 1.45879 × 10^-Four
    A₆= -7.06884 × 10^-6
    A₈= 1.23121 × 10^-7
    A_Ten= -5.62979 × 10^-Ten
    4th page
    K = 0.000
    A_Four= -5.29316 × 10^-Five
    A₆= 3.56817 × 10^-6
    A₈= -1.11723 × 10^-6
    A_Ten= 1.49013 × 10^-8
    8th page
    K = -3.680
    A_Four= -2.43119 × 10^-Four
    A₆= 1.50423 × 10^-6
    A₈= -8.73464 × 10^-8
    A_Ten= 2.80319 × 10^-9
    10th page
    K = -0.000
    A_Four= -7.77230 × 10^-Four
    A₆= 1.47499 × 10^-Five
    A₈= -1.23145 × 10^-6
    A_Ten= 1.55776 × 10^-7
    11th page
    K = 0.000
    A_Four= 6.35918 × 10^-Four
    A₆= 3.49158 × 10^-Five
    A₈= -2.91520 × 10^-6
    A_Ten= 2.80196 × 10^-7
    15th page
    K = 0.000
    A_Four= 4.02871 × 10^-Five
    A₆= 1.18379 × 10^-Five
    A₈= -4.08960 × 10^-7
    A_Ten= 5.70846 × 10^-9
Zoom data (∞)
                   WE ST TE
f (mm)      5.06 11.98 24.29
F_NO                 3.11 4.53 5.05
2ω (°)   81.61 36.13 18.35
d₂                 0.72 4.72 12.77
d₈                11.25 4.14 0.96
d₁₄                 2.79 7.94 9.79
d₁₆                 2.84 2.99 3.34.

Example 20
r₁= 24.617 d₁= 0.80 n_d1= 1.94595 ν_d1= 17.98
r₂= 16.485 d₂= 0.34
r_Three= 18.513 d_Three= 3.03 n_d2= 1.88300 ν_d2= 40.76
r_Four= -1350.827 d_Four= (Variable)
r_Five= -39.777 (aspherical surface) d_Five= 0.79 n_d3= 1.80610 ν_d3= 40.92
r₆= 5.736 (aspherical surface) d₆= 2.50
r₇= 46.539 d₇= 1.93 n_d4= 1.94595 ν_d4= 17.98
r₈= -22.674 d₈= 0.64 n_d5= 1.80610 ν_d5= 40.92
r₉= 177.436 (aspherical surface) d₉= (Variable)
r_Ten= ∞ (aperture) d_Ten= (Variable)
r₁₁= 5.325 (aspherical surface) d₁₁= 2.70 n_d6= 1.58913 ν_d6= 61.14
r₁₂= -9.884 (aspherical surface) d₁₂= 0.10
r₁₃= 6.305 d₁₃= 1.41 n_d7= 1.59201 ν_d7= 67.02
r₁₄= 18.239 d₁₄= 0.80 n_d8= 2.00069 ν_d8= 25.46
r₁₅= 3.616 d₁₅= (Variable)
r₁₆= 17.024 (aspherical surface) d₁₆= 2.07 n_d9= 1.74330 ν_d9= 49.33
r₁₇= 34.757 d₁₇= (Variable)
r₁₈= ∞ d₁₈= 0.40 n_d10= 1.54771 ν_d10= 62.84
r₁₉= ∞ d₁₉= 0.50
r₂₀= ∞ d₂₀= 0.50 n_d11= 1.51633 ν_d11= 64.14
r_{twenty one}= ∞ d_{twenty one}= 0.37
r_{twenty two}= ∞ (image plane)
Aspheric coefficient
    5th page
    K = 0.000
    A_Four= 2.65294 × 10^-Four
    A₆= -4.86067 × 10^-6
    A₈= -4.95916 × 10^-8
    A_Ten= 1.45582 × 10^-9
    6th page
    K = 0.000
    A_Four= 1.22290 × 10^-Four
    A₆= 3.07865 × 10^-Five
    A₈= -1.23246 × 10^-6
    A_Ten= -2.75048 × 10^-8
    9th page
    K = -4.077
    A_Four= -3.44903 × 10^-Four
    A₆= 4.47305 × 10^-6
    A₈= -7.49149 × 10^-7
    A_Ten= 2.89043 × 10^-8
    11th page
    K = -0.000
    A_Four= -1.06943 × 10^-3
    A₆= 1.88431 × 10^-Five
    A₈= -3.97910 × 10^-6
    A_Ten= 3.05632 × 10^-7
    12th page
    K = 0.000
    A_Four= 7.51908 × 10^-Four
    A₆= 1.59771 × 10^-Five
    A₈= -2.43151 × 10^-6
    A_Ten= 2.99982 × 10^-7
    16th page
    K = 0.000
    A_Four= 2.22601 × 10^-Five
    A₆= 1.31566 × 10^-Five
    A₈= -4.73811 × 10^-7
    A_Ten= 7.81341 × 10^-9
Zoom data (∞)
                   WE ST TE
f (mm)      5.06 12.01 24.28
F_NO                 3.07 4.72 5.05
2ω (°)   80.13 35.38 17.61
d_Four                 0.71 4.88 13.53
d₉                 9.86 4.07 0.85
d_Ten                 1.54 0.22 0.28
d₁₅                 2.73 8.32 9.66
d₁₇                 2.75 2.95 2.96.

  FIGS. 21 to 40 show aberration diagrams of Examples 1 to 20 when focusing on an object point at infinity, respectively. In these aberration diagrams, (a) is a wide-angle end, (b) is an intermediate state, and (c) is spherical aberration, astigmatism, distortion, and lateral chromatic aberration at a telephoto end. In each figure, “FIY” indicates the maximum image height.

Next, the values of conditional expressions (1) to (21) in the above-described embodiments will be shown.
Example 1 2 3 4 5 6 7
(1) 0.128 0.131 0.129 0.165 0.173 0.144 0.130
(2) -0.973 -0.916 -1.030 -0.954 -0.986 -0.949 -0.931
(3) 0.142 0.144 0.142 0.168 0.171 0.153 0.142
(4) 2.0017 1.94595 2.0017 1.92286 1.92286 1.94595 2.10226
(5) 20.6 18.0 20.6 18.9 18.9 18.0 17.1
(6) 1.142 1.270 0.930 1.132 1.037 1.070 1.240
(7) 1.8830 1.8348 1.8830 1.8348 1.8348 1.8830 1.8830
(8) 40.8 42.7 40.8 42.7 42.7 40.8 40.8
(9) 1.8160 1.8348 1.8348 1.8348 1.8348 1.8830 1.8830
(10) 46.6 42.7 42.7 42.7 42.7 40.8 40.8
(11) -1.505 -1.976 -1.370 -1.738 -1.545 -2.038 -1.967
(12) 2.001 2.553 1.885 2.416 2.341 2.334 2.477
(13A) 0.029 0.030 0.027 0.036 0.054 0.052 0.028
(13B) -0.007 -0.008 -0.006 -0.004 -0.001 -0.008 -0.008
(14) -0.025 -0.021 -0.025 -0.025 -0.025 -0.019 -0.019
(15) 0.008 0.005 0.005 0.009 0.006 0.006 0.006
(16) 0.310 0.311 0.312 0.311 0.314 0.309 0.309
(17) 1.383 1.383 1.380 1.385 1.385 1.367 1.367
(18) 0.370 0.372 0.371 0.371 0.371 0.371 0.370
(19) 0.636 0.646 0.641 0.640 0.643 0.645 0.640
(20) 0.759 0.759 0.759 0.759 0.759 0.759 0.759
(21) 4.800 4.800 4.800 4.799 4.800 4.801 4.800
.
Example 8 9 10 11 12 13 14
(1) 0.118 0.162 0.013 0.094 0.111 0.172 0.108
(2) -0.950 -0.936 -1.116 -0.977 -0.978 -1.000 -0.884
(3) 0.134 0.166 0.100 0.117 0.134 0.174 0.130
(4) 2.10226 1.92286 2.10226 2.0017 2.0017 1.94595 2.0017
(5) 17.1 18.9 17.1 20.6 20.6 17.98 20.64
(6) 1.178 1.175 0.647 1.057 1.052 1.000 1.303
(7) 1.8830 1.8061 1.8830 1.8830 1.8830 1.8061 1.883
(8) 40.8 40.9 40.8 40.8 40.8 40.92 40.76
(9) 1.8830 1.8061 1.8830 1.8160 1.8160 1.8061 1.816
(10) 40.8 40.9 40.8 46.6 46.6 40.92 46.62
(11) -1.545 -1.491 -1.195 -1.775 -1.621 -1.193 -1.806
(12) 2.548 2.215 2.307 1.953 1.936 2.195 2.038
(13A) 0.035 0.053 0.027 0.013 0.020 0.047 0.033
(13B) 0.001 -0.001 -0.001 -0.013 -0.020 -0.010 -0.008
(14) -0.022 -0.028 -0.022 -0.026 -0.019 -0.021 -0.022
(15) 0.006 0.008 0.000 0.006 0.006 0.008 0.006
(16) 0.309 0.312 0.312 0.306 0.307 0.305 0.296
(17) 1.371 1.386 1.501 1.393 1.396 1.394 1.376
(18) 0.370 0.372 0.356 0.366 0.366 0.264 0.270
(19) 0.637 0.642 0.657 0.631 0.632--
(20) 0.759 0.759 0.759 0.759 0.759 0.759 0.759
(21) 4.799 4.799 4.798 4.800 4.800 4.800 4.800
.
Example 15 16 17 18 19 20
(1) 0.185 0.012 0.115 0.084 0.067 0.192
(2) -0.971 -0.951 -0.901 -1.413 -1.498 -1.281
(3) 0.179 0.100 0.138 0.089 0.068 0.186
(4) 1.92286 2.10226 1.94595 1.94595 1.94595 1.94595
(5) 18.90 17.10 17.98 17.98 17.98 17.98
(6) 1.081 1.165 1.336 0.277 0.151 0.345
(7) 1.83481 1.883 1.83481 1.883 1.883 1.8061
(8) 42.71 40.76 42.71 40.76 40.76 40.92
(9) 1.83481 1.883 1.83481 1.8830 1.8830 1.8061
(10) 42.71 40.76 42.71 40.76 40.76 40.92
(11) -1.625 -1.210 -2.009 -1.045 -0.999 -0.773
(12) 2.400 2.458 2.657 1.874 1.831 2.140
(13A) 0.061 0.050 0.031 0.025 0.051 0.034
(13B) -0.004 0.008 -0.008 -0.010 -0.051 -0.034
(14) -0.022 -0.018 -0.020 -0.022 -0.017 -0.025
(15) 0.006 0.000 0.005--0.010
(16) 0.306 0.297 0.302 0.313 0.303 0.314
(17) 1.376 1.467 1.370 1.476 1.414 1.382
(18) 0.265 0.277 0.269 0.349 0.351 0.370
(19)---0.687 0.671 0.644
(20) 0.758 0.759 0.759 0.759 0.760 0.759
(21) 4.797 4.800 4.800 4.802 4.804 4.798
.

  In each embodiment, the following configuration may be adopted.

  In order to cut off unnecessary light such as ghost and flare, a flare stop other than the brightness stop S may be arranged. The object side of the first lens group G1, between the first lens group G1 and the second lens group G2, between the second lens group G2 and the third lens group G3, between the third lens group G3 and the fourth lens group G4, and fourth. It may be arranged at any location between the lens group G4 and the image plane I, between the fourth lens group G4 and the fifth lens group G5, and between the fifth lens group G5 and the image plane I. Moreover, you may comprise so that a flare ray may be cut with a frame member, and you may comprise another member. Also, it may be printed directly on the surface of the lens, painted, or adhered with a seal or the like. Further, the shape may be any shape such as a circle, an ellipse, a rectangle, a polygon, or a range surrounded by a function curve. Further, not only the harmful light flux but also the light flux such as coma flare around the screen may be cut.

  Each lens may be provided with an antireflection coating to reduce ghosts and flares. A multi-coat is desirable because it can effectively reduce ghost and flare. Moreover, you may give an infrared cut coat to a lens surface, a cover glass, etc.

  Further, focusing for adjusting the focus is preferably performed by the fourth lens group G4 or the fifth lens group G5. When focusing is performed by the fourth lens group G4 or the fifth lens group G5, the weight of the lens is light, so that a load applied to a drive system such as a motor is small. Furthermore, the total length does not change during focusing, and the drive motor can be arranged inside the lens frame, which is advantageous for making the lens frame compact. As described above, the fourth lens group G4 focusing and the fifth lens group G5 focusing are desirable, but the first lens group G1, the second lens group G2, and the third lens group G3 may perform focusing. Further, focusing may be performed by moving a plurality of lens groups. Further, focusing may be performed by extending the entire lens system, or a part of the lenses in the group may be extended or focused by focusing.

  Further, the shading of the brightness at the periphery of the image may be reduced by shifting the micro lens of the CCD. For example, the design of the CCD microlens may be changed according to the incident angle of the light beam at each image height. Further, the amount of decrease in the peripheral portion of the image may be corrected by image processing.

  Alternatively, the distortion may be intentionally generated by the optical system, and the distortion may be corrected by electrically performing image processing after shooting. A basic concept for digitally correcting image distortion in that case will be described.

For example, as shown in FIG. 42, the magnification on the circumference (image height) of the radius R inscribed in the long side of the effective imaging surface around the intersection of the optical axis and the imaging surface is fixed, and this circumference is Use as a reference for correction. Then, correction is performed by moving each point on the circumference (image height) of any other radius r (ω) in a substantially radial direction and concentrically so as to have the radius r ′ (ω). To do. For example, in FIG. 42, a point P ₁ on the circumference of an arbitrary radius r ₁ (ω) located inside the circle of radius R is a radius r ₁ ′ (ω) circle to be corrected toward the center of the circle. Move to point P ₂ on the circumference. A point Q ₁ on the circumference of an arbitrary radius r ₂ (ω) located outside the circle of radius R is on the radius r ₂ ′ (ω) circumference to be corrected in a direction away from the center of the circle. To point Q ₂ . Here, r ′ (ω) can be expressed as follows.

r ′ (ω) = αf tan ω (0 ≦ α ≦ 1)
Here, ω is the subject half angle of view, and f is the focal length of the imaging optical system (in the present invention, the zoom lens).

Here, if the ideal image height corresponding to the circle (image height) of the radius r is Y,
α = R / Y = R / ftanω
It becomes.

  The optical system is ideally rotationally symmetric with respect to the optical axis, that is, distortion is also generated rotationally symmetric with respect to the optical axis. Therefore, as described above, when the optically generated distortion aberration is electrically corrected, the radius inscribed in the long side of the effective imaging surface around the intersection of the optical axis and the imaging surface on the reproduced image. The magnification on the circumference of the circle of R (image height) is fixed, and the other points on the circumference of the circle (image height) of radius r (ω) are moved in a substantially radial direction to obtain a radius r ′ ( If correction can be performed by moving the concentric circles so that ω), it is considered advantageous in terms of data amount and calculation amount.

However, the optical image is no longer a continuous amount (due to sampling) when captured by the electronic image sensor. Therefore, strictly speaking, the circle with the radius R drawn on the optical image is not an accurate circle unless the pixels on the electronic image sensor are arranged radially. That is, in the shape correction of the image data represented for each discrete coordinate point, there is no circle that can fix the magnification. Therefore, it is preferable to use a method of determining the coordinates (X ′ _i , Y ′ _j ) of the movement destination for each pixel (X _i , Y _j ). When two or more points (X _i , Y _j ) have moved to the coordinates (X ′ _i , Y ′ _j ), the average value of the values of each pixel is taken. If there is no moving point, interpolation may be performed using the values of the coordinates (X ′ _i , Y ′ _j ) of some surrounding pixels.

  Such a method is particularly distorted with respect to the optical axis due to a manufacturing error of an optical system or an electronic imaging element in an electronic imaging device included in a zoom lens, and the circle with the radius R drawn on the optical image is It is effective for correction when it becomes asymmetric. Further, it is effective for correction when a geometric distortion or the like occurs when a signal is reproduced as an image in an image sensor or various output devices.

  In the electronic imaging apparatus of the present invention, in order to calculate the correction amount r ′ (ω) −r (ω), r (ω), that is, the relationship between the half field angle and the image height, or the real image height r and the ideal image height. The relationship between r ′ / α may be recorded on a recording medium built in the electronic imaging apparatus.

  Note that the radius R preferably satisfies the following conditional expression so that the image after distortion correction does not have an extremely short amount of light at both ends in the short side direction.

0 ≦ R ≦ 0.6L _s
Note that L _s is the length of the short side of the effective imaging surface.

  Preferably, the radius R satisfies the following conditional expression.

0 ≦ R ≦ 0.6L _s
Furthermore, it is most advantageous that the radius R is substantially equal to the radius of the inscribed circle in the short side direction of the effective imaging surface. In the case of correction in which the magnification is fixed in the vicinity of the radius R = 0, that is, in the vicinity of the axis, there is a slight disadvantage in terms of the actual number of pixels, but the effect of reducing the size is ensured even if the angle is widened. it can.

The focal length section that needs to be corrected is divided into several focal zones. Then, in the vicinity of the telephoto end in the divided focal zone, approximately r ′ (ω) = αf tan ω
You may correct | amend with the same correction amount as the case where the correction result which satisfies is obtained. However, in that case, some barrel distortion remains at the wide-angle end in the divided focal zone. Further, if the number of divided zones is increased, it becomes unnecessary to store extraneous data necessary for correction on the recording medium, which is not preferable. Therefore, one or several coefficients related to each focal length in the divided focal zone are calculated in advance. This coefficient may be determined on the basis of simulation or actual measurement. Then, in the vicinity of the telescope in the divided zone, approximately r ′ (ω) = αf tan ω
It is also possible to calculate a correction amount when a correction result satisfying the above is obtained, and uniformly multiply the correction amount for each focal distance to obtain a final correction amount.

By the way, if there is no distortion in the image obtained by imaging an object at infinity,
f = y / tan ω
Is established. Where y is the height (image height) of the image point from the optical axis, f is the focal length of the imaging system (in the present invention, the zoom lens), and ω is the image point connecting from the center on the imaging surface to the y position. It is an angle (subject half field angle) with respect to the optical axis in the corresponding object direction.

If the imaging system has barrel distortion,
f> y / tan ω
It becomes. That is, if the focal length f of the imaging system and the image height y are constant, the value of ω increases.

  43 to 45 are conceptual diagrams of the configuration of a digital camera according to the present invention in which the zoom lens as described above is incorporated in the photographing optical system 41. FIG. 43 is a front perspective view showing the appearance of the digital camera 40, FIG. 44 is a rear front view thereof, and FIG. 45 is a schematic cross-sectional view showing the configuration of the digital camera 40. However, in FIGS. 43 and 45, the photographing optical system 41 is not retracted. In this example, the digital camera 40 includes a photographing optical system 41 located on the photographing optical path 42, a finder optical system 43 located on the finder optical path 44, a shutter button 45, a flash 46, a liquid crystal display monitor 47, a focal length. When the photographic optical system 41 is retracted, the photographic optical system 41, the finder optical system 43, and the flash 46 are covered with the cover 60, including the change button 61, the setting change switch 62, and the like. Then, when the cover 60 is opened and the camera 40 is set to the photographing state, the photographing optical system 41 enters the non-collapsed state of FIG. 45, and when the shutter button 45 disposed on the upper part of the camera 40 is pressed, the photographing is performed in conjunction therewith. Photographing is performed through the optical system 41, for example, the zoom lens of the first embodiment. An object image formed by the photographic optical system 41 is formed on the imaging surface (photoelectric conversion surface) of the CCD 49 via a low-pass filter F and a cover glass C that are provided with a wavelength band limiting coat. The object image received by the CCD 49 is displayed as an electronic image on the liquid crystal display monitor 47 provided on the back of the camera via the processing means 51. In addition, a recording means 52 is connected to the processing means 51 so that a photographed electronic image can be recorded. The recording means 52 may be provided separately from the processing means 51, or may be a floppy disk or the like. The recording and writing may be performed electronically using a memory card, MO, or the like. Further, it may be configured as a silver salt camera in which a silver salt film is arranged in place of the CCD 49.

  Further, a finder objective optical system 53 is disposed on the finder optical path 44. The finder objective optical system 53 includes a plurality of lens groups (three groups in the figure) and an erecting prism system 55 including erecting prisms 55a, 55b, and 55c, and is linked to the zoom lens of the photographing optical system 41. The object image formed by the finder objective optical system 53 is formed on a field frame 57 of an erecting prism system 55 that is an image erecting member. Behind the erecting prism system 55, an eyepiece optical system 59 for guiding the erect image to the observer eyeball E is disposed. A cover member 50 is disposed on the exit side of the eyepiece optical system 59.

  FIG. 46 is a block diagram showing the internal circuitry of the main part of the digital camera 40. In the following description, the processing unit 51 includes, for example, the CDS / ADC unit 24, the primary storage memory 17, the image processing unit 18, and the storage unit 52 includes the storage medium unit 19, for example.

  As shown in FIG. 46, the digital camera 40 is connected to the operation unit 12, the control unit 13 connected to the operation unit 12, and the control signal output port of the control unit 13 via buses 14 and 15. An imaging drive circuit 16, a primary storage memory 17, an image processing unit 18, a storage medium unit 19, a display unit 20, and a setting information storage memory unit 21 are provided.

  The primary storage memory 17, the image processing unit 18, the storage medium unit 19, the display unit 20, and the setting information storage memory unit 21 are configured so that data can be input or output with each other via the bus 22. The imaging drive circuit 16 is connected with a CCD 49 and a CDS / ADC unit 24.

The operation unit 12 includes various input buttons and switches, and is a circuit that notifies the control unit of event information input from the outside (camera user) via these input buttons and switches.
The control unit 13 is a central processing unit composed of, for example, a CPU, and has a built-in program memory (not shown). The control unit 13 is input by a camera user via the operation unit 12 according to a program stored in the program memory. This circuit controls the entire digital camera 40 in response to the instruction command.

  The CCD 49 receives an object image formed via the photographing optical system 41 according to the present invention. The CCD 49 is an image pickup element that is driven and controlled by the photographing drive circuit 16 and converts the light amount of each pixel of the object image into an electrical signal and outputs it to the CDS / ADC unit 24.

  The CDS / ADC unit 24 amplifies the electric signal input from the CCD 49 and performs analog / digital conversion, and temporarily generates the raw video data (Bayer data, hereinafter referred to as RAW data) that has just been subjected to the amplification and digital conversion. It is a circuit that outputs to the memory 17.

  The primary storage memory 17 is a buffer made of, for example, SDRAM, and is a memory device that temporarily stores the RAW data output from the CDS / ADC unit 24. The image processing unit 18 reads out the RAW data stored in the primary storage memory 17 or the RAW data stored in the storage medium unit 19, and performs various corrections including distortion correction based on the image quality parameter designated by the control unit 13. It is a circuit that performs image processing electrically.

  The storage medium unit 19 detachably mounts a card-type or stick-type recording medium made of, for example, a flash memory, and the RAW data transferred from the primary storage memory 17 to the card-type or stick-type flash memory It is a control circuit of an apparatus that records and holds image data processed by the image processing unit 18.

  The display unit 20 includes a liquid crystal display monitor 47 and is a circuit that displays an image, an operation menu, and the like on the liquid crystal display monitor 47. The setting information storage memory unit 21 stores a ROM unit in which various image quality parameters are stored in advance, and an image quality parameter selected by an input operation of the operation unit 12 among the image quality parameters read from the ROM unit. RAM section is provided. The setting information storage memory unit 21 is a circuit for controlling input / output to / from these memories.

  In the digital camera 40 configured in this manner, the imaging optical system 41 has a sufficiently wide angle range according to the present invention, and a compact configuration, while the imaging performance is extremely stable at a high zoom ratio and in a full zoom ratio range. Therefore, high performance, downsizing, and wide angle can be realized. In addition, fast focusing operation on the wide-angle side and the telephoto side is possible.

  The present invention may be applied not only to a so-called compact digital camera that captures a general subject as described above, but also to a surveillance camera that requires a wide angle of view and an interchangeable lens camera.

FIG. 2 is a lens cross-sectional view at the wide-angle end (a), the intermediate state (b), and the telephoto end (c) when focusing on an object point at infinity according to the first exemplary embodiment of the zoom lens of the present invention. It is the same figure as FIG. 1 of Example 2 of the zoom lens of this invention. It is the same figure as FIG. 1 of Example 3 of the zoom lens of this invention. It is the same figure as FIG. 1 of Example 4 of the zoom lens of this invention. It is the same figure as FIG. 1 of Example 5 of the zoom lens of this invention. It is the same figure as FIG. 1 of Example 6 of the zoom lens of this invention. It is the same figure as FIG. 1 of Example 7 of the zoom lens of this invention. It is a figure similar to FIG. 1 of Example 8 of the zoom lens of this invention. It is the same figure as FIG. 1 of Example 9 of the zoom lens of this invention. It is a figure similar to FIG. 1 of Example 10 of the zoom lens of this invention. It is the same figure as FIG. 1 of Example 11 of the zoom lens of this invention. It is the same figure as FIG. 1 of Example 12 of the zoom lens of this invention. It is the same figure as FIG. 1 of Example 13 of the zoom lens of this invention. It is the same figure as FIG. 1 of Example 14 of the zoom lens of this invention. It is the same figure as FIG. 1 of Example 15 of the zoom lens of this invention. It is the same figure as FIG. 1 of Example 16 of the zoom lens of this invention. It is a figure similar to FIG. 1 of Example 17 of the zoom lens of this invention. It is the same figure as FIG. 1 of Example 18 of the zoom lens of this invention. It is the same figure as FIG. 1 of Example 19 of the zoom lens of this invention. It is the same figure as FIG. 1 of Example 20 of the zoom lens of this invention. FIG. 6 is an aberration diagram for Example 1 upon focusing on an object point at infinity. FIG. 6 is an aberration diagram for Example 2 upon focusing on an object point at infinity. FIG. 10 is an aberration diagram for Example 3 upon focusing on an object point at infinity. FIG. 10 is an aberration diagram for Example 4 upon focusing on an object point at infinity. FIG. 10 is an aberration diagram for Example 5 upon focusing on an object point at infinity. FIG. 10 is an aberration diagram for Example 6 upon focusing on an object point at infinity. FIG. 10 is an aberration diagram for Example 7 upon focusing on an object point at infinity. FIG. 10 is an aberration diagram for Example 8 upon focusing on an object point at infinity. FIG. 10 is an aberration diagram for Example 9 upon focusing on an object point at infinity. FIG. 10 is an aberration diagram for Example 10 upon focusing on an object point at infinity. FIG. 10 is an aberration diagram for Example 11 upon focusing on an object point at infinity. FIG. 14 is an aberration diagram for Example 12 upon focusing on an object point at infinity. FIG. 14 is an aberration diagram for Example 13 upon focusing on an object point at infinity. FIG. 16 is an aberration diagram for Example 14 upon focusing on an object point at infinity. FIG. 18 is an aberration diagram for Example 15 upon focusing on an object point at infinity. FIG. 16 is an aberration diagram for Example 16 upon focusing on an object point at infinity. FIG. 18 is an aberration diagram for Example 17 upon focusing on an object point at infinity. FIG. 20 is an aberration diagram for Example 18 upon focusing on an object point at infinity. FIG. 27 is an aberration diagram for Example 19 upon focusing on an object point at infinity. FIG. 20 is an aberration diagram for Example 20 upon focusing on an object point at infinity. It is a figure for demonstrating the definition of the amount of aspherical deviation. It is a figure for demonstrating the basic concept for carrying out the digital correction of the distortion of an image. It is a front perspective view which shows the external appearance of the digital camera by this invention. FIG. 44 is a rear perspective view of the digital camera of FIG. 43. It is sectional drawing of the digital camera of FIG. FIG. 44 is a configuration block diagram of an internal circuit of a main part of the digital camera of FIG. 43.

Explanation of symbols

G1 ... 1st lens group G2 ... 2nd lens group G3 ... 3rd lens group G4 ... 4th lens group G5 ... 5th lens group S ... Aperture stop F ... Optical low-pass filter C ... Cover glass I ... Image plane E ... Observer eyeball 12 ... operation section 13 ... control sections 14 and 15 ... bus 16 ... imaging drive circuit 17 ... primary storage memory 18 ... image processing section 19 ... storage medium section 20 ... display section 21 ... setting information storage memory section 22 ... bus 24 ... CDS / ADC section 40 ... digital camera 41 ... photographing optical system 42 ... photographing optical path 43 ... finder optical system 44 ... finder optical path 45 ... shutter button 46 ... flash 47 ... liquid crystal display monitor 49 ... CCD
DESCRIPTION OF SYMBOLS 50 ... Cover member 51 ... Processing means 52 ... Recording means 53 ... Finder objective optical system 55 ... Erect prism system 55a, 55b, 55c, ... Erect prism 57 ... Field frame 59 ... Eyepiece optical system 60 ... Cover 61 ... Focus Distance change button 62 ... Setting change switch

Claims (36)

In order from the object side, it has a first lens group with positive refractive power, a second lens group with negative refractive power, and a third lens group with positive refractive power,
During zooming from the wide-angle end to the telephoto end, the distance between the first lens group and the second lens group and the distance between the second lens group and the third lens group are changed,
The distance between the first lens group and the second lens group is wider at the telephoto end than at the wide angle end,
The distance between the second lens group and the third lens group is narrower at the telephoto end than at the wide-angle end,
The first lens group includes a positive lens, and the total number of lenses is two or less.
The second lens group is composed of three lenses in order from the object side: an object-side negative lens, a positive lens, and an image-side negative lens;
The object side surface and the image side surface of the object side negative lens are both concave surfaces,
The image side surface of the positive lens is a convex surface on the image side, and the curvature radius absolute value of the image side surface is smaller than the curvature radius absolute value of the object side surface,
The object side negative lens and the positive lens in the second lens group are arranged with an air gap on the optical axis,
A zoom lens satisfying the following conditional expression:
0.0 <f ₂ / R _2n1f <0.4 (1)
−1.6 <SF _2air <−0.5 (2)
Where R _2n1f is the paraxial radius of curvature of the object side surface of the object side negative lens in the second lens group,
f ₂ is the focal length of the second lens group,
SF _2air = (R _2n1r + R _2pf ) / (R _2n1r −R _2pf )
R _2n1r is the paraxial radius of curvature of the image side surface of the object side negative lens of the second lens group,
R _2pf is the paraxial radius of curvature of the object side surface of the positive lens in the second lens group,
It is.   2. The zoom lens according to claim 1, wherein the number of lenses on the image side of the third lens group of the zoom lens is three or less.   3. The zoom lens according to claim 1, wherein the zoom lens is a four-group zoom lens having a fourth lens group having a positive refractive power.   The zoom lens according to claim 1, wherein the zoom lens is a four-group zoom lens having a fourth lens group composed of one positive lens.   3. The zoom lens according to claim 2, wherein the zoom lens is a five-group zoom lens having a fourth lens group having a negative refractive power and a fifth lens group having a positive refractive power. The zoom lens according to claim 1, wherein the following conditional expression is satisfied.
0.00 <(1 / R _2n1f −1 / R _1r ) · f ₂ <0.40 (3)
Where R _1r is the paraxial radius of curvature of the image side surface of the most image side lens in the first lens group,
It is. The zoom lens according to claim 1, wherein the following conditional expression is satisfied.
1.84 <n _d2p <2.20 (4)
13.0 <ν _d2p <30.0 (5)
Where n _d2p is the refractive index of the positive lens in the second lens group with respect to the d-line,
ν _d2p is the Abbe number of the positive lens in the second lens group,
It is. The zoom lens according to claim 1, wherein the following conditional expression is satisfied.
0.45 <SF _2p <1.80 (6)
However, as defined in _{SF 2p = (R 2pf + R} 2pr) / (R 2pf -R 2pr),
R _2pf is the paraxial radius of curvature of the object side surface of the positive lens in the second lens group,
R _2pr is the paraxial radius of curvature of the image side surface of the positive lens in the second lens group,
It is. The zoom lens according to claim 1, wherein the following conditional expression is satisfied.
1.78 <n _d2n1 <2.20 (7)
35 <ν _d2n1 <50 (8)
Where n _d2n1 is the refractive index of the object side negative lens in the second lens group with respect to the d-line,
ν _d2n1 is the Abbe number of the object side negative lens in the second lens group,
It is. The zoom lens according to any one of claims 1 to 9, wherein the following conditional expression is satisfied.
1.78 <n _d2n2 <2.00 (9)
35 <ν _d2n2 <50 (10)
Where n _d2n2 is the refractive index of the image-side negative lens in the second lens group with respect to the d-line,
ν _d2n2 is the Abbe number of the image-side negative lens in the second lens group,
It is. The zoom lens according to claim 1, wherein the following conditional expression is satisfied.
−3.0 <SF _2n2 <−0.6 (11)
However, SF _2n2 = (R _2n2f + R _2n2r ) / (R _2n2f −R _2n2r ),
R _2n1f is the paraxial radius of curvature of the object side surface of the image side negative lens in the second lens group,
R _2n1r is the paraxial radius of curvature of the image side surface of the image side negative lens in the second lens group,
It is. The zoom lens according to claim 1, wherein the following conditional expression is satisfied.
−3.0 <f _2p / f ₂ <−1.0 (12)
Where f _2p is the focal length of the positive lens in the second lens group,
It is. 13. The zoom lens according to claim 1, wherein at least one lens surface of the object-side negative lens of the second lens group is an aspherical surface, and satisfies the following conditional expression.
0.002 <(asp _2n1f + | asp _2n1r |) / f _w <0.10
... (13A)
−0.06 <(asp _2n1r −asp _2n1f ) / f _w <0.06 (13B)
Where asp _2n1f is the amount of aspherical deviation on the object-side lens surface of the object-side negative lens in the second lens group,
asp _2n1r is the amount of aspherical deviation on the image side lens surface of the object side negative lens in the second lens group,
f _w is the focal length of the entire zoom lens system at the wide-angle end,
The aspherical deviation amount is the same as the surface top of the lens surface, and when a spherical surface having the paraxial curvature radius of the lens surface as the radius of curvature is defined as a reference spherical surface, This is the distance from the reference spherical surface to the lens surface when measured in the direction parallel to the optical axis at the position of maximum light incident height, the image side direction is a positive sign, and the non-surface when the lens surface is spherical or flat. The amount of spherical deviation is zero.   14. The zoom lens according to claim 13, wherein an object side surface of the object-side negative lens in the second lens group is an aspheric surface whose refractive power increases as the distance from the optical axis increases.   The object-side negative lens in the second lens group is a biconcave negative lens, and the object side surface of the biconcave negative lens is an aspheric surface whose negative refractive power decreases as the distance from the optical axis increases. The zoom lens according to claim 14, wherein the image side surface of the lens is an aspherical surface in which negative refractive power increases as the distance from the optical axis increases. The zoom lens according to claim 1, wherein an image-side lens surface of the image-side negative lens in the second lens group is an aspherical surface, and satisfies the following conditional expression: .
−0.09 <(asp _2n2r −asp _2n2f ) / f _w < _−0.003 (14)
Where asp _2n2f is the amount of aspherical deviation on the object-side lens surface of the image-side negative lens in the second lens group,
asp _2n2r is the amount of aspherical deviation on the image side lens surface of the image side negative lens in the second lens group,
f _w is the focal length of the entire zoom lens system at the wide-angle end,
The aspherical deviation amount is the same as the surface top of the lens surface, and the spherical surface having the paraxial radius of curvature of the lens surface as a reference spherical surface is a reference spherical surface. This is the distance from the reference spherical surface to the lens surface when measured in the direction parallel to the optical axis at the position where the maximum light incident height is reached. The amount of spherical deviation is zero.   The image-side negative lens of the second lens group is a negative meniscus lens having a convex surface facing the image side, and the image-side surface of the negative meniscus lens has an aspheric surface whose positive refractive power increases as the distance from the optical axis increases. The zoom lens according to claim 16, wherein:   18. The zoom lens according to claim 1, wherein each of the positive lens and the image-side negative lens of the second lens group is a single lens.   The zoom lens according to claim 1, wherein the positive lens and the image-side negative lens of the second lens group are cemented.   The zoom lens according to any one of claims 1 to 19, wherein the first lens group includes a positive lens and a negative lens. 21. The zoom lens according to claim 20, wherein the first lens group includes two lenses of the negative lens and the positive lens in order from the object side.
  The zoom lens according to claim 21, wherein the negative lens and the positive lens of the first lens group are each a single lens. 23. The zoom lens according to claim 22, wherein an interval between the negative lens and the positive lens in the first lens group satisfies the following conditional expression.
0.0 ≦ L _1np / L ₁ <0.2 (15)
Where L _1np is the distance between the negative lens and the positive lens in the first lens group,
L ₁ is the total thickness on the axis of the first lens group.   The zoom lens according to claim 21, wherein the negative lens and the positive lens of the first lens group are cemented.   The zoom lens according to claim 1, wherein the first lens group includes one positive lens.   The zoom lens according to any one of claims 1 to 25, wherein the third lens group includes three or less lenses.   27. The zoom lens according to claim 26, wherein the third lens group includes three lenses of a positive lens, a positive lens, and a negative lens in order from the object side. 28. The zoom lens according to claim 1, wherein the following conditional expression is satisfied.
0.20 <| f ₂ / f _t | <0.325 (16)
Where f ₂ is the focal length of the second lens group,
f _t is the focal length of the entire zoom lens system at the telephoto end,
It is. The zoom lens according to claim 1, wherein the following conditional expression is satisfied.
_{0.7 <f 1 / f t <} 1.8 ··· (17)
Where f ₁ is the focal length of the first lens group,
f _t is the focal length of the entire zoom lens system at the telephoto end,
It is. The zoom lens according to any one of claims 1 to 29, wherein the following conditional expression is satisfied.
0.25 <f ₃ / _ft <0.50 (18)
Where f ₃ is the focal length of the third lens group,
f _t is the focal length of the entire zoom lens system at the telephoto end,
It is. The zoom lens according to claim 3, wherein the following conditional expression is satisfied.
0.40 <f ₄ / _ft <1.0 (19)
Where f ₄ is the focal length of the fourth lens group,
f _t is the focal length of the entire zoom lens system at the telephoto end,
It is.   At the time of zooming from the wide-angle end to the telephoto end, the distance between the first lens group and the second lens group increases, the distance between the second lens group and the third lens group decreases, and the third lens group The first lens group, the second lens group, the third lens group, and the fourth lens group move so that a distance between the first lens group and the fourth lens group is increased. The zoom lens according to any one of 4 and 31.   At the time of zooming from the wide angle end to the telephoto end, the first lens group moves so that it is closer to the object side at the telephoto end than the wide angle end, the second lens group moves, and the third lens group moves toward the object side. 33. The zoom lens according to claim 32, wherein the zoom lens moves only to, and the fourth lens group moves. The zoom lens according to any one of claims 1 to 33, wherein the following conditional expression is satisfied.
3.8 < _ft / _fw <15.0 (21)
Where f _w is the focal length of the entire zoom lens system at the wide-angle end,
f _t is the focal length of the entire zoom lens system at the telephoto end,
It is.   35. A zoom lens according to any one of claims 1 to 34, and an electronic imaging device that is disposed on an image side of the zoom lens and converts an optical image formed by the zoom lens into an electric signal. An electronic imaging device. 36. The electronic imaging apparatus according to claim 35, wherein the following conditional expression is satisfied.
0.70 <I _m / f _w <1.00 (20)
Where _Im is the maximum image height,
f _w is the focal length of the entire zoom lens system at the wide-angle end,
It is.

Images