JP2006171055A - Zoom lens and imaging apparatus using same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-variable-power zoom lens made small in collapsing thickness and having high performance. <P>SOLUTION: The zoom lens constituted of four groups is equipped with a 1st group G1 having positive refractive power, a 2nd group G2 having negative refractive power, a 3rd group G3 having positive refractive power, and a 4th lens group G4 having positive refractive power. In the case of variable power from a wide angle end to a telephoto end, the 1st group G1 to the 4th group G4 are each moved so that a space between the 1st group G1 and the 2nd group G2 may be increased, a space between the 2nd group G2 and the 3rd group G3 may be decreased, and a space between the 3rd group G3 and the 4th group G4 may be increased. The 1st group G1 comprises one negative lens and one positive lens in order from an object side, the 2nd group G2 comprises two negative lenses and one positive lens in order from the object side, and the 3rd group G3 comprises four or less lenses. The zoom lens satisfies a conditional expression; 0.3<f<SB>3</SB>/f<SB>4</SB><1.4, wherein f<SB>3</SB>and f<SB>4</SB>are the focal distances of the 3rd group and the 4th group respectively. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a zoom lens and an image pickup apparatus using the same, and more particularly to a high-magnification zoom lens corresponding to an electronic image pickup element such as a CCD or C-MOS and an image pickup apparatus using the same.

As a zoom lens system having a large zoom ratio, good imaging performance, and shortening the total lens length, in order from the object side, a positive first lens group, a negative second lens group, a positive third lens group, For example, Patent Document 1 proposes a lens having a fourth lens group and moving all the lens groups to change the magnification.
JP 2004-12439 A

  The present invention has been made in view of such a situation in the prior art, and an object of the present invention is to provide a high-performance zoom lens having a high retractable thickness and a high-magnification zoom lens and an imaging apparatus using the zoom lens.

The first zoom lens of the present invention that achieves the above object, in order from the object side, is 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, A zoom lens having a four-group configuration including a fourth lens group having positive refractive power,
When zooming from the wide-angle end to the telephoto end,
An air gap between the first lens group and the second lens group is increased;
An air gap between the second lens group and the third lens group is reduced;
In order to increase the air gap between the third lens group and the fourth lens group,
Each of the first lens group, the second lens group, the third lens group, and the fourth lens group moves,
The first lens group includes one negative lens and one positive lens in order from the object side.
The second lens group includes two negative lenses and one positive lens in order from the object side.
The third lens group includes four or less lenses.
The following conditional expression is satisfied.

0.3 <f ₃ / f ₄ <1.4 (1)
Where f _{3 is} the focal length of the third lens group,
f ₄ : focal length of the fourth lens group,
It is.

  Hereinafter, the reason and action of the above-described configuration in the first zoom lens of the present invention will be described.

  In the negative leading type in which the first lens unit has negative refractive power, the zoom ratio can be up to about 4 times.

  In the first zoom lens, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a fourth lens having a positive refractive power. As a zoom lens having a four-group structure composed of a group, the zoom ratio is about 8 times or more.

  When zooming from the wide-angle end to the telephoto end, the air gap between the first lens group and the second lens group increases, the air gap between the second lens group and the third lens group decreases, and the third lens Each lens group is moved so that the air space between the group and the fourth lens group is increased, so that the burden of zooming is shared by both the second lens group and the third lens group.

  When such a lens group power arrangement and movement method is adopted, the diameter of the first lens group becomes large. Therefore, if the first lens group is composed of three or more lenses, the thickness of the group can be reduced. Can not. Therefore, the first lens group is composed of one negative lens and one positive lens.

  In addition, in order to obtain a zoom ratio with the second lens group, it is necessary to secure a space for zooming by reducing the thickness of the group while having power. For this reason, the second lens group includes two negative lenses and one positive lens.

  The third lens group is composed of four or less lenses in order to reduce the thickness of the group while providing an imaging function and satisfactorily suppressing aberrations.

  The third lens group and the fourth lens group satisfy the following conditional expressions.

0.3 <f ₃ / f ₄ <1.4 (1)
Where f _{3 is} the focal length of the third lens group,
f ₄ : focal length of the fourth lens group,
It is.

  If the lower limit of 0.3 of the conditional expression (1) is exceeded, the power of the fourth lens group becomes too weak, and the amount of movement in image plane correction or focusing becomes large, which is disadvantageous for making the lens frame compact. Become. On the other hand, if the upper limit of 1.4 is exceeded, the power of the third lens group becomes weak, making it difficult to obtain a zooming effect, which is disadvantageous for high zooming.

The second zoom lens of the present invention includes, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a first lens group having a positive refractive power. A zoom lens having a four-group structure including four lens groups,
When zooming from the wide-angle end to the telephoto end,
An air gap between the first lens group and the second lens group is increased;
An air gap between the second lens group and the third lens group is reduced;
In order to increase the air gap between the third lens group and the fourth lens group,
Each of the first lens group, the second lens group, the third lens group, and the fourth lens group moves,
The first lens group includes two or less lenses,
The second lens group includes two negative lenses and one positive lens in order from the object side.
The third lens group includes four or less lenses.
The following conditional expression is satisfied.

−23 <dt _0.5dw <−6.0 (2)
However, dt _0.5dw is the distortion of the maximum image height at the wide-angle end, and the unit is%.

  Hereinafter, the reason and action of the second zoom lens according to the present invention will be described.

  In the negative leading type in which the first lens unit has negative refractive power, the zoom ratio can be up to about 4 times.

  In the first zoom lens, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a fourth lens having a positive refractive power. As a zoom lens having a four-group structure composed of a group, the zoom ratio is about 8 times or more.

  When zooming from the wide-angle end to the telephoto end, the air gap between the first lens group and the second lens group increases, the air gap between the second lens group and the third lens group decreases, and the third lens Each lens group is moved so that the air space between the group and the fourth lens group is increased, so that the burden of zooming is shared by both the second lens group and the third lens group.

  When such a lens group power arrangement and movement method is adopted, the diameter of the first lens group becomes large. Therefore, if the first lens group is composed of three or more lenses, the thickness of the group can be reduced. Can not. Therefore, the first lens group is composed of two or less lenses.

  In addition, in order to obtain a zoom ratio with the second lens group, it is necessary to secure a space for zooming by reducing the thickness of the group while having power. For this reason, the second lens group includes two negative lenses and one positive lens.

  The third lens group is composed of four or less lenses in order to reduce the thickness of the group while providing an imaging function and satisfactorily suppressing aberrations.

  The following conditional expression is satisfied regarding the distortion of the maximum image height at the wide-angle end.

−23 <dt _0.5dw <−6.0 (2)
However, dt _0.5dw is the distortion of the maximum image height at the wide-angle end, and the unit is%.

  If the lower limit of the conditional expression (2) is −23, the aberration balance is lost and the performance is degraded. In addition, correction in image processing also increases processing time and makes correction difficult. If it is larger than the upper limit of −6.0, the amount of chromatic aberration generated in the first lens group increases, and the performance deteriorates.

  Furthermore, it is more preferable that the lower limit value of conditional expression (2) is -13.0.

  Or it is more preferable when the upper limit of conditional expression (2) is -9.0.

The third zoom lens of the present invention includes, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a first lens group having a positive refractive power. A zoom lens having a four-group structure including four lens groups,
When zooming from the wide-angle end to the telephoto end,
An air gap between the first lens group and the second lens group is increased;
An air gap between the second lens group and the third lens group is reduced;
In order to increase the air gap between the third lens group and the fourth lens group,
Each of the first lens group, the second lens group, the third lens group, and the fourth lens group moves,
The first lens group includes two or less lenses,
The second lens group is composed of a biconcave lens, a negative lens, and a positive lens in order from the object side with an air gap in between.
The third lens group is composed of four or less lenses.

  Hereinafter, the reason and action of the third zoom lens according to the present invention will be described.

  In the negative leading type in which the first lens unit has negative refractive power, the zoom ratio can be up to about 4 times.

  In the first zoom lens, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a fourth lens having a positive refractive power. As a zoom lens having a four-group structure composed of a group, the zoom ratio is about 8 times or more.

  When zooming from the wide-angle end to the telephoto end, the air gap between the first lens group and the second lens group increases, the air gap between the second lens group and the third lens group decreases, and the third lens Each lens group is moved so that the air space between the group and the fourth lens group is increased, so that the burden of zooming is shared by both the second lens group and the third lens group.

  When such a lens group power arrangement and movement method is adopted, the diameter of the first lens group becomes large. Therefore, if the first lens group is composed of three or more lenses, the thickness of the group can be reduced. Can not. Therefore, the first lens group is composed of two or less lenses.

  In addition, in order to obtain a zoom ratio with the second lens group, it is necessary to secure a space for zooming by reducing the thickness of the group while having power. Furthermore, by disposing two air gaps in the second lens group, on-axis and off-axis aberration correction is effectively performed, and the burden on the first lens group and the third lens group can be reduced. The thickness of the group can also be reduced. For this reason, the second lens group is composed of a biconcave lens, a negative lens, and a positive lens in order from the object side, with an air gap therebetween.

  The third lens group is composed of four or less lenses in order to reduce the thickness of the group while providing an imaging function and satisfactorily suppressing aberrations.

  According to a fourth zoom lens of the present invention, in the third zoom lens, the second lens group includes an air gap in order from the object side, the biconcave lens, and a biconcave lens as the negative lens, It consists of the said positive lens.

  Hereinafter, the reason and operation of the fourth zoom lens according to the present invention will be described. By using two biconcave lenses in the second lens group, including an air lens between them, aberration correction is further facilitated. Become.

The fifth zoom lens according to the present invention includes, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a first lens group having a positive refractive power. A zoom lens having a four-group structure including four lens groups,
When zooming from the wide-angle end to the telephoto end,
An air gap between the first lens group and the second lens group is increased;
An air gap between the second lens group and the third lens group is reduced;
In order to increase the air gap between the third lens group and the fourth lens group,
Each of the first lens group, the second lens group, the third lens group, and the fourth lens group moves,
The first lens group includes two or less lenses,
The second lens group includes two negative lenses and one positive lens in order from the object side.
The third lens group includes four or less lenses.
The following conditional expression is satisfied.

2.4 <(β _2t / β _2w ) <5.7 (3)
Where β _2t : lateral magnification of the second lens group at the telephoto end,
β _2w : lateral magnification of the second lens group at the wide-angle end,
It is.

  Hereinafter, the reason and operation of the fifth zoom lens according to the present invention will be described.

  In the negative leading type in which the first lens unit has negative refractive power, the zoom ratio can be up to about 4 times.

  In the first zoom lens, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a fourth lens having a positive refractive power. As a zoom lens having a four-group structure composed of a group, the zoom ratio is about 8 times or more.

  When zooming from the wide-angle end to the telephoto end, the air gap between the first lens group and the second lens group increases, the air gap between the second lens group and the third lens group decreases, and the third lens Each lens group is moved so that the air space between the group and the fourth lens group is increased, so that the burden of zooming is shared by both the second lens group and the third lens group.

  When such a lens group power arrangement and movement method is adopted, the diameter of the first lens group becomes large. Therefore, if the first lens group is composed of three or more lenses, the thickness of the group can be reduced. Can not. Therefore, the first lens group is composed of two or less lenses.

  In addition, in order to obtain a zoom ratio with the second lens group, it is necessary to secure a space for zooming by reducing the thickness of the group while having power. For this reason, the second lens group includes two negative lenses and one positive lens.

  The third lens group is composed of four or less lenses in order to reduce the thickness of the group while providing an imaging function and satisfactorily suppressing aberrations.

  The following conditional expression is satisfied for the lateral magnification at the telephoto end and the wide-angle end of the second lens group.

2.4 <(β _2t / β _2w ) <5.7 (3)
Where β _2t : lateral magnification of the second lens group at the telephoto end,
β _2w : lateral magnification of the second lens group at the wide-angle end,
It is.

  If the lower limit of the conditional expression (3) is less than 2.4, the variable magnification burden of the third lens group increases, the amount of movement of the third lens group increases, and the lens unit becomes large. In addition, when the zooming load of the fourth lens group is increased, the aberration in the fourth lens group is increased and the performance is deteriorated. If the upper limit of 5.7 in conditional expression (3) is exceeded, the power of the second lens group will increase, the aberration will increase, and the performance will deteriorate. Alternatively, the amount of movement of the second lens group is increased, and the height of incident light at the wide-angle end is increased, leading to an increase in the lens diameter of the first lens group.

  Furthermore, it is more preferable that the upper limit value of conditional expression (3) is 3.5.

The sixth zoom lens of the present invention includes, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a first lens group having a positive refractive power. A zoom lens having a four-group structure including four lens groups,
When zooming from the wide-angle end to the telephoto end,
An air gap between the first lens group and the second lens group is increased;
An air gap between the second lens group and the third lens group is reduced;
In order to increase the air gap between the third lens group and the fourth lens group,
Each of the first lens group, the second lens group, the third lens group, and the fourth lens group moves,
The first lens group includes two or less lenses,
The second lens group includes two negative lenses and one positive lens in order from the object side.
The third lens group includes four or less lenses.
The following conditional expression is satisfied.

_{0.01 <f 1 / f t <} 1.00 ··· (4)
Where f _{1 is} the focal length of the first lens group,
f _t : focal length of the entire zoom lens system at the telephoto end,
It is.

  Hereinafter, the reason and operation of the sixth zoom lens according to the present invention will be described.

  In the negative leading type in which the first lens unit has negative refractive power, the zoom ratio can be up to about 4 times.

  In the first zoom lens, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a fourth lens having a positive refractive power. As a zoom lens having a four-group structure composed of a group, the zoom ratio is about 8 times or more.

  When zooming from the wide-angle end to the telephoto end, the air gap between the first lens group and the second lens group increases, the air gap between the second lens group and the third lens group decreases, and the third lens Each lens group is moved so that the air space between the group and the fourth lens group is increased, so that the burden of zooming is shared by both the second lens group and the third lens group.

  When such a lens group power arrangement and movement method is adopted, the diameter of the first lens group becomes large. Therefore, if the first lens group is composed of three or more lenses, the thickness of the group can be reduced. Can not. Therefore, the first lens group is composed of two or less lenses.

  In addition, in order to obtain a zoom ratio with the second lens group, it is necessary to secure a space for zooming by reducing the thickness of the group while having power. For this reason, the second lens group includes two negative lenses and one positive lens.

  The third lens group is composed of four or less lenses in order to reduce the thickness of the group while providing an imaging function and satisfactorily suppressing aberrations.

  The following conditional expression is satisfied with respect to the focal length of the first lens group.

_{0.01 <f 1 / f t <} 1.00 ··· (4)
Where f _{1 is} the focal length of the first lens group,
f _t : focal length of the entire zoom lens system at the telephoto end,
It is.

  When the lower limit of 0.01 of conditional expression (4) is not reached, the amount of aberration generated in the first lens group increases, making it difficult to obtain good imaging performance. When the upper limit of the conditional expression (4) is larger than 1.00, it is difficult to perform zooming in a later group while maintaining a reduction in size.

  Furthermore, it is more preferable that the lower limit value of conditional expression (4) is 0.2, further 0.7.

  Or it is more preferable when the upper limit of conditional expression (4) is 0.9.

The seventh zoom lens according to the present invention includes, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a first lens group having a positive refractive power. A zoom lens having a four-group structure including four lens groups,
When zooming from the wide-angle end to the telephoto end,
An air gap between the first lens group and the second lens group is increased;
An air gap between the second lens group and the third lens group is reduced;
In order to increase the air gap between the third lens group and the fourth lens group,
Each of the first lens group, the second lens group, the third lens group, and the fourth lens group moves,
The first lens group includes one negative lens and one positive lens in order from the object side.
The second lens group includes a biconcave lens, a negative lens, and a positive lens in order from the object side and sequentially from the object side, with an air gap therebetween.
The third lens group includes four or less lenses.
The following conditional expression is satisfied.

0.3 <f ₃ / f ₄ <1.4 (1)
−23 <dt _0.5dw <−6.0 (2)
2.4 <(β _2t / β _2w ) <5.7 (3)
_{0.01 <f 1 / f t <} 1.00 ··· (4)
Where f _{1 is} the focal length of the first lens group,
f ₃ : focal length of the third lens group,
f ₄ : focal length of the fourth lens group,
f _t : focal length of the entire zoom lens system at the telephoto end,
dt _0.5dw : Maximum image height distortion at the wide-angle end. The unit is%.
β _2t : lateral magnification of the second lens group at the telephoto end,
β _2w : lateral magnification of the second lens group at the wide-angle end,
It is.

  Hereinafter, the reason and operation of the seventh zoom lens according to the present invention will be described.

  It is more preferable that the above-described first to third and fifth to sixth zoom lenses have a plurality of configurations at the same time.

  For example, the configuration of the first zoom lens and the configuration of the second zoom lens may be provided.

  The configuration of the first zoom lens and the configuration of the third zoom lens may be provided.

  The first zoom lens configuration and the fifth zoom lens configuration may be provided.

  The configuration of the first zoom lens and the configuration of the sixth zoom lens may be provided.

  The configuration of the second zoom lens and the configuration of the third zoom lens may be provided.

  The second zoom lens configuration and the fifth zoom lens configuration may be provided.

  The configuration of the second zoom lens and the configuration of the sixth zoom lens may be provided.

  A configuration of a third zoom lens and a configuration of a fifth zoom lens may be provided.

  A configuration of a third zoom lens and a configuration of a sixth zoom lens may be provided.

  A fifth zoom lens configuration and a sixth zoom lens configuration may be provided.

  In particular, the seventh zoom lens is more preferably a four-group zoom lens including all the configurations of the first to third and fifth to sixth zoom lenses.

  The eighth zoom lens of the present invention is characterized in that, in the first to seventh zoom lenses, the following conditional expression is satisfied.

0.01 <| f ₂ / f _t | <0.2 (5)
Where f _{2 is} the focal length of the second lens group,
f _t : focal length of the entire zoom lens system at the telephoto end,
It is.

  Hereinafter, the reason and action of the above-described configuration in the eighth zoom lens of the present invention will be described. When the lower limit of conditional expression (5) is less than 0.01, the amount of aberration generated in the second lens group increases. It is difficult to obtain good imaging performance. If the upper limit of 0.2 is exceeded, the amount of movement increases to perform zooming, and the overall length increases.

  Furthermore, it is more preferable that the lower limit value of conditional expression (5) is 0.1 or 0.15.

  The ninth zoom lens of the present invention is characterized in that, in the first to eighth zoom lenses, the following conditional expression is satisfied.

0.01 <f ₃ / _ft <0.3 (6)
Where f _{3 is} the focal length of the third lens group,
f _t : focal length of the entire zoom lens system at the telephoto end,
It is.

  Hereinafter, the reason and action of the ninth zoom lens according to the present invention will be described. When the lower limit of 0.01 in the conditional expression (6) is reduced, the amount of aberration generated in the third lens group increases. Therefore, it becomes difficult to obtain good imaging performance, and sufficient back focus cannot be obtained. When the upper limit of 0.3 is exceeded, the zooming action in the third lens group becomes weak, and the total length during zooming on the telephoto side becomes long. Furthermore, since the variation amount of the exit pupil position becomes large, the fluctuation of the incident angle of the imaging element, for example, the CCD at the off-axis image plane position becomes large, which adversely affects shading.

  Furthermore, it is more preferable that the lower limit value of conditional expression (6) is 0.1 or 0.2.

  The tenth zoom lens of the present invention is characterized in that, in the first to ninth zoom lenses, the following conditional expression is satisfied.

0.01 <f ₄ / _ft <0.55 (7)
Where f _{4 is} the focal length of the fourth lens group,
f _t : focal length of the entire zoom lens system at the telephoto end,
It is.

  Hereinafter, the reason and action of the above-described configuration in the tenth zoom lens of the present invention will be described. If the lower limit of conditional expression (7) is less than 0.01, the amount of aberration generated in the fourth lens group increases. Thus, it is difficult to obtain good imaging performance. When the focal length of the fourth lens group becomes larger than the upper limit of 0.55, it becomes difficult to perform zooming in the subsequent group while maintaining a reduction in size.

  Furthermore, it is more preferable that the lower limit value of conditional expression (7) is 0.1 or 0.25.

  Or it is more preferable when the upper limit of conditional expression (7) is 0.4.

  The eleventh zoom lens of the present invention is characterized in that, in the first to tenth zoom lenses, the following conditional expression is satisfied.

0.5 <L _t / f _t <1.5 (8)
Where L _t is the total length on the optical axis from the entrance surface of the zoom lens to the image surface at the telephoto end,
f _t : focal length of the entire zoom lens system at the telephoto end,
It is.

  Hereinafter, the reason and operation of the eleventh zoom lens according to the present invention will be described. If the lower limit of 0.5 of the conditional expression (8) is not satisfied, the first lens group and the second lens group are not satisfied. Since the distance between the lens group and the third lens group and the fourth lens group becomes narrow, it becomes impossible to secure a space necessary for zooming. If the upper limit of 1.5 is exceeded, the total length at the telephoto end becomes long, leading to an increase in the size of the lens unit.

  The twelfth zoom lens of the present invention is characterized in that, in the first to eleventh zoom lenses, the following conditional expression is satisfied.

2.20 <Δ _t1g / f _w <5.0 (9)
Where Δ _t1g is the difference between the position of the first lens group at the wide-angle end and the position at the telephoto end,
f _w : focal length of the entire zoom lens system at the wide angle end,
It is.

  Hereinafter, the reason and action of the twelfth zoom lens according to the present invention will be described. When the lower limit of 2.20 of the conditional expression (9) is exceeded, the incident light height at the wide angle end increases. The lens diameter of the first lens group increases, or the space necessary for zooming cannot be secured. If the upper limit of 5.0 is exceeded, the total length at the telephoto end becomes large, and as a result, the lens unit becomes large.

  The thirteenth zoom lens of the present invention is characterized in that, in the first to twelfth zoom lenses, the following conditional expression is satisfied.

8.0 <(D _1t + D _2w ) / f _w <10.0 (10)
Where D _1t is the air space between the first lens group and the second lens group at the telephoto end,
D _2w : the air space between the second lens group and the third lens group at the wide-angle end,
f _w : focal length of the entire zoom lens system at the wide angle end,
It is.

  The reason and action of the above-described configuration in the thirteenth zoom lens of the present invention will be described below. If the lower limit of the conditional expression (10) is less than 8.0, the space necessary for zooming cannot be secured. When the upper limit of 10.0 is exceeded, the total length at the telephoto end becomes large, and as a result, the lens unit becomes large.

  The fourteenth zoom lens of the present invention is characterized in that, in the first to thirteenth zoom lenses, the following conditional expression is satisfied.

1.05 <(β _2t / β _2w ) / (β _3t / β _3w ) <5.7 (11)
Where β _2t : lateral magnification of the second lens group at the telephoto end,
β _2w : lateral magnification of the second lens group at the wide-angle end,
β _3t : Lateral magnification of the third lens group at the telephoto end,
β _3w : lateral magnification of the third lens unit at the wide-angle end,
It is.

  Hereinafter, the reason and action of the above-described configuration in the fourteenth zoom lens of the present invention will be described. If the lower limit of conditional expression (11) is less than 1.05, the variable magnification burden of the third lens group increases. The amount of movement of the third lens group increases and the lens unit becomes large. In addition, when the zooming load of the fourth lens group is increased, the aberration in the fourth lens group is increased and the performance is deteriorated. When the upper limit of 5.7 is exceeded, the power of the second lens group increases, the aberration increases, and the performance decreases. Alternatively, the amount of movement increases, and the incident light height at the wide-angle end increases, so that the lens diameter of the first lens group increases.

  Furthermore, it is more preferable that the upper limit value of conditional expression (11) is 3.5.

  A fifteenth zoom lens according to the present invention is characterized in that, in the first to fourteenth zoom lenses, the following conditional expression is satisfied.

0.82 <Σd _1g / f _w <1.5 (12)
Where Σd _1g is the thickness of the first lens group on the optical axis,
f _w : focal length of the entire zoom lens system at the wide angle end,
It is.

  Hereinafter, the reason and operation of the fifteenth zoom lens according to the present invention will be described. The thickness of the first lens unit on the optical axis is smaller than 0.82 which is the lower limit of the conditional expression (12). Then, it becomes difficult to perform zooming in a later group while maintaining miniaturization. Or, it becomes difficult to secure the edge of the lens. When the thickness of the first lens unit on the optical axis becomes larger than the upper limit of 1.5, the retractable thickness increases.

  Furthermore, it is more preferable that the lower limit value of conditional expression (12) is 0.85.

  Or it is more preferable when the upper limit of conditional expression (12) is 1.1.

  The sixteenth zoom lens of the present invention is characterized in that, in the first to fifteenth zoom lenses, the following conditional expression is satisfied.

_{0.05 <Σd 2g / f t <} 0.15 ··· (13)
Where Σd _2g : thickness of the second lens group on the optical axis,
f _t : focal length of the entire zoom lens system at the telephoto end,
It is.

  Hereinafter, the reason and action of the above-described configuration in the sixteenth zoom lens of the present invention will be described. The thickness of the second lens unit on the optical axis is smaller than 0.05, the lower limit of conditional expression (13). Then, it becomes difficult to perform zooming while maintaining the performance. Or, it becomes difficult to secure the edge of the lens. When the thickness of the second lens unit on the optical axis becomes larger than the upper limit of 0.15, the retractable thickness increases.

  Furthermore, it is more preferable that the lower limit value of conditional expression (13) is 0.1.

  The seventeenth zoom lens according to the present invention is characterized in that, in the first to sixteenth zoom lenses, the following conditional expression is satisfied.

_{0.05 <Σd 3g / f t <} 0.12 ··· (14)
Where Σd _3g is the thickness of the third lens group on the optical axis,
f _t : focal length of the entire zoom lens system at the telephoto end,
It is.

  Hereinafter, the reason and action of the above-described configuration in the seventeenth zoom lens of the present invention will be described. The thickness of the third lens unit on the optical axis is smaller than 0.05, which is the lower limit of conditional expression (14). Then, it becomes difficult to perform zooming while maintaining the performance. Or, it becomes difficult to secure the edge of the lens. When the thickness of the third lens unit on the optical axis becomes larger than the upper limit of 0.12, the retractable thickness increases.

  Furthermore, it is more preferable that the lower limit value of conditional expression (14) is 0.1.

  The eighteenth zoom lens according to the present invention is characterized in that, in the first to seventeenth zoom lenses, the following conditional expression is satisfied.

_{0.1 <Σd / f t <0.43} ··· (15)
Where Σd: the sum of the thickness on the optical axis of each of the first lens group, the second lens group, the third lens group, and the fourth lens group,
f _t : focal length of the entire zoom lens system at the telephoto end,
It is.

  Hereinafter, the reason and action of the above-described configuration in the eighteenth zoom lens of the present invention will be described. When Σd becomes smaller than the lower limit of 0.1 of the conditional expression (15), zooming is performed while maintaining performance. Harder to do. Or, it becomes difficult to secure the edge of the lens. When Σd becomes larger than the upper limit of 0.43, the collapsed thickness becomes thick.

  Furthermore, it is more preferable that the lower limit value of conditional expression (15) is 0.2 or 0.3.

  Or it is more preferable when the upper limit of conditional expression (15) is 0.4.

  According to a nineteenth zoom lens of the present invention, in the first to eighteenth zoom lenses, only one negative lens is included in the first lens group, and the negative lens satisfies the following conditional expression: It is characterized by this.

n _d ≧ 1.90 (16)
Where n _d is the refractive index of the negative lens material of the first lens group at the d-line,
It is.

  The reason and action of the above-described configuration in the nineteenth zoom lens of the present invention will be described below. When the lower limit of 1.90 to conditional expression (16) is exceeded, chromatic aberration correction becomes difficult.

  A twentieth image pickup apparatus of the present invention is characterized by including first to nineteenth zoom lenses and an image pickup element that is disposed on the image side and converts an optical image into an electric signal.

  Hereinafter, the reason and action of the above configuration in the twentieth imaging apparatus of the present invention will be described. The zoom lens of the present invention described above is advantageous for increasing the zoom ratio while keeping the exit pupil far from the image plane. Zoom lens. Therefore, when the zoom lens of the present invention is used in an image pickup apparatus using an image pickup element that converts an optical image such as a CCD or C-MOS into an electric signal, an image pickup apparatus that hardly causes color shading can be configured.

  Further, the zoom lens described above has a high zoom ratio with a small retractable thickness and high performance. Therefore, if such a zoom lens is mounted on an imaging apparatus as an imaging optical system, it is possible to reduce the size and increase the functionality. In addition to the digital camera, the imaging device includes a video camera, a digital video unit, and the like.

  The zoom lenses according to the above inventions can be more effectively combined with any combination. In addition, in common with each of the above conditional expressions, only the upper limit value of the lower conditional expression that limits the range of each conditional expression or only the lower limit value is limited as the upper limit value or lower limit value of the upper conditional expression. It may be.

  Moreover, the effect of this invention can be heightened more by combining the above conditional expressions arbitrarily.

  According to the present invention, a zoom lens having a very small thickness when retracted (when retracted) and an extremely stable image forming performance in a high zooming range and an imaging device equipped with such a zoom lens are obtained. Can do.

  Examples 1 to 12 of the zoom lens according to the present invention will be described below. FIGS. 1 to 11 show lens cross-sectional views of 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 11, respectively. In the 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, a parallel plate constituting a low-pass filter with IR cut coating, and the like. Is indicated by F, the parallel plate of the cover glass of the electronic image sensor is indicated by C, and the image plane is indicated by I. In addition, you may give the multilayer film for a wavelength range restriction | limiting to the surface of the cover glass C. FIG. Further, the cover glass C may have a low-pass filter action.

  As shown in FIG. 1, the zoom lens according to the first 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 positive refractive power. The third lens group G3 and a fourth lens group G4 having positive refractive power, and the first lens group G1 has a convex locus on the image side when zooming from the wide-angle end to the telephoto end. The telephoto end is located closer to the object side than the wide-angle end position, the second lens group G2 is moved to the image side, the aperture stop S and the third lens group G3 are integrally moved to the object side, The fourth lens group G4 moves along a locus convex toward the object side, and is positioned 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 cemented lens of a negative meniscus lens having a convex surface facing the object side and a biconvex positive lens, and the second lens group G2 includes two biconcave negative lenses and a biconvex lens. The third lens group G3 includes a biconvex positive lens, a cemented lens 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 group G4 includes one positive meniscus lens having a convex surface directed toward the object side.

  The aspheric surfaces are used for the three surfaces of the object side surface of the biconvex positive lens of the third lens group G3 and the both surfaces of the positive meniscus lens of the fourth lens group G4.

  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 positive refractive power. The third lens group G3 and a fourth lens group G4 having positive refractive power, and the first lens group G1 has a convex locus on the image side when zooming from the wide-angle end to the telephoto end. The telephoto end is positioned closer to the object side than the wide-angle end position, and the second lens group G2 moves while drawing a convex locus on the image side while increasing the distance from the first lens group G1. The telephoto end is located closer to the image side than the wide-angle end position, the aperture stop S and the third lens group G3 move together toward the object side, and the fourth lens group G4 moves along a locus convex toward the object side. The telephoto end is located closer to the object side than the wide-angle end.

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

  The aspheric surfaces are used for the three surfaces of the object side surface of the biconvex positive lens of the third lens group G3 and the both surfaces of the biconvex positive lens of the fourth lens group G4.

  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 positive refractive power. The third lens group G3 and a fourth lens group G4 having positive refractive power, and when zooming from the wide angle end to the telephoto end, the first lens group G1 moves to the object side, The second lens group G2 moves along a locus locus convex toward the image side while widening the distance from the first lens group G1, and is located on the image side from the wide-angle end position at the telephoto end. The third lens group G3 moves integrally toward the object side, and the fourth lens group G4 moves along a locus convex toward the object side, and is located 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 cemented lens of a negative meniscus lens having a convex surface facing the object side and a biconvex positive lens, and the second lens group G2 includes two biconcave negative lenses and a biconvex lens. The third lens group G3 includes a biconvex positive lens, a cemented lens 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 group G4 is composed of one biconvex positive lens.

  The aspheric surfaces are used on both surfaces of the biconvex positive lens of the third lens group G3 and on both surfaces of the biconvex positive lens of the fourth lens group G4.

  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 positive refractive power. The third lens group G3 and a fourth lens group G4 having positive refractive power, and when zooming from the wide angle end to the telephoto end, the first lens group G1 moves to the object side, The second lens group G2 moves along a locus locus convex toward the image side while widening the distance from the first lens group G1, and is located on the image side from the wide-angle end position at the telephoto end. The third lens group G3 moves integrally to the object side, the fourth lens group G4 moves along a locus convex toward the object side, and is located slightly on the image side at the telephoto end from the wide-angle end position.

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

  The aspheric surfaces are used on both surfaces of the biconvex positive lens of the third lens group G3 and on both surfaces of the biconvex positive lens of the fourth lens group G4.

  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 positive refractive power. The third lens group G3 and a fourth lens group G4 having positive refractive power, and when zooming from the wide angle end to the telephoto end, the first lens group G1 moves to the object side, The second lens group G2 moves along a locus locus convex toward the image side while widening the distance from the first lens group G1, and is located on the image side from the wide-angle end position at the telephoto end. The third lens group G3 moves integrally toward the object side, and the fourth lens group G4 moves along a locus convex toward the object side, and is located 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 cemented lens of a negative meniscus lens having a convex surface facing the object side and a biconvex positive lens, and the second lens group G2 includes two biconcave negative lenses and a biconvex lens. The third lens group G3 is composed of a biconvex positive lens, and a cemented lens of a biconvex positive lens and a biconcave negative lens. The fourth lens group G4 is a positive lens having a convex surface facing the object side. Consists of a single meniscus lens.

  The aspheric surfaces are used on both surfaces of the biconvex positive lens of the third lens group G3 and on both surfaces of the positive meniscus lens of the fourth lens group G4.

  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 positive refractive power. The third lens group G3 and a fourth lens group G4 having positive refractive power, and when zooming from the wide angle end to the telephoto end, the first lens group G1 moves to the object side, The second lens group G2 moves along a locus locus convex toward the image side while widening the distance from the first lens group G1, and is located on the image side from the wide-angle end position at the telephoto end. The third lens group G3 moves integrally toward the object side, and the fourth lens group G4 moves along a locus convex toward the object side, 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 cemented lens of a negative meniscus lens having a convex surface facing the object side and a biconvex positive lens, and the second lens group G2 includes two biconcave negative lenses and a biconvex lens. The third lens group G3 includes a biconvex positive lens, a cemented lens 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 group G4 is composed of one biconvex positive lens.

  The aspheric surfaces are used on both surfaces of the biconvex positive lens of the third lens group G3 and on both surfaces of the biconvex positive lens of the fourth lens group G4.

  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 positive refractive power. The third lens group G3 and a fourth lens group G4 having positive refractive power, and when zooming from the wide angle end to the telephoto end, the first lens group G1 moves to the object side, The second lens group G2 moves along a locus locus convex toward the image side while widening the distance from the first lens group G1, and is located on the image side from the wide-angle end position at the telephoto end. The third lens group G3 moves integrally toward the object side, and the fourth lens group G4 moves along a locus convex toward the object side, and is located 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 cemented lens of a negative meniscus lens having a convex surface facing the object side and a biconvex positive lens, and the second lens group G2 includes two biconcave negative lenses and a biconvex lens. The third lens group G3 includes a biconvex positive lens, a cemented lens 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 group G4 is composed of one biconvex positive lens.

  The aspheric surfaces are used on both surfaces of the biconvex positive lens of the third lens group G3 and on both surfaces of the biconvex positive lens of the fourth lens group G4.

  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 positive refractive power. The third lens group G3 and a fourth lens group G4 having positive refractive power, and when zooming from the wide angle end to the telephoto end, the first lens group G1 moves to the object side, The second lens group G2 moves along a locus locus convex toward the image side while widening the distance from the first lens group G1, and is located on the image side from the wide-angle end position at the telephoto end. The third lens group G3 moves integrally to the object side, the fourth lens group G4 moves along a locus convex toward the object side, and is located slightly on the image side at the telephoto end from the wide-angle end position.

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

  The aspheric surfaces are used on both surfaces of the biconvex positive lens of the third lens group G3 and on both surfaces of the positive meniscus lens of the fourth lens group G4.

  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 positive refractive power. The third lens group G3 and a fourth lens group G4 having positive refractive power, and when zooming from the wide angle end to the telephoto end, the first lens group G1 moves to the object side, The second lens group G2 moves along a locus locus convex toward the image side while widening the distance from the first lens group G1, and is located on the image side from the wide-angle end position at the telephoto end. The third lens group G3 moves integrally to the object side, and the fourth lens group G4 moves along a locus convex toward the object side, and is located closer to the image side than the wide-angle end position at the telephoto end.

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

  The aspheric surfaces are used on both surfaces of the biconvex positive lens of the third lens group G3 and on both surfaces of the positive meniscus lens of the fourth lens group G4.

  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 positive refractive power. The third lens group G3 and a fourth lens group G4 having positive refractive power, and when zooming from the wide angle end to the telephoto end, the first lens group G1 moves to the object side, The second lens group G2 moves along a locus locus convex toward the image side while widening the distance from the first lens group G1, and is located on the image side from the wide-angle end position at the telephoto end. The third lens group G3 moves integrally to the object side, the fourth lens group G4 moves along a locus convex toward the object side, and is located slightly on the image side at the telephoto end from the wide-angle end position.

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

  The aspheric surfaces are used on both surfaces of the biconvex positive lens of the third lens group G3 and on both surfaces of the positive meniscus lens of the fourth lens group G4.

  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 positive refractive power. The third lens group G3 and the fourth lens group G4 having positive refractive power, and when zooming from the wide-angle end to the telephoto end, the first lens group G1 moves to the object side, The second lens group G2 moves along a locus convex toward the image side while widening the distance from the first lens group G1, and is positioned closer to the image side than the wide-angle end position at the telephoto end. The third lens group G3 moves integrally to the object side, and the fourth lens group G4 moves along a locus convex toward the object side, and is slightly closer to the image side than the wide-angle end position at the telephoto end.

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

  The aspheric surfaces are used on both surfaces of the biconvex positive lens of the third lens group G3 and on both surfaces of the positive meniscus lens of the fourth lens group G4.

In the following, numerical data of each of the above embodiments is shown. Symbols are the above, IH is the image height, f is the total focal length, _FNO is the F number, WE is the wide angle end, ST is the intermediate state, and TE is The telephoto end, r ₁ , r ₂ ... Is the radius of curvature of each lens surface, d ₁ , d ₂ ... _Are the distances between the lens surfaces, n _d1 , n _d2 are the refractive index of the d-line of each lens, ν _d1 , ν _d2 ... is the Abbe number of each lens. The aspherical shape is represented by the following formula, where x is an optical axis with the light traveling direction being positive, and y is a direction orthogonal to the optical axis.

x = (y ² / r) / [1+ {1- (K + 1) (y / r) ² } ^1/2 ]
+ A ₄ y ⁴ + A ₆ y ⁶ + A ₈ y ⁸ + A ₁₀ y ¹⁰
Here, r is a paraxial radius of curvature, K is a conical coefficient, and A ₄ , A ₆ , A ₈ , and A ₁₀ are fourth-order, sixth-order, eighth-order, and tenth-order aspherical coefficients, respectively.

Example 1
IH = 3.6mm
r ₁ = 29.61 d ₁ = 1.0 n _d1 = 1.90366 ν _d1 = 31.31
r ₂ = 19.42 d ₂ = 4.8 n _d2 = 1.58913 ν _d2 = 61.14
r ₃ = -162.69 d ₃ = (variable)
r ₄ = -158.26 d ₄ = 0.9 n _d3 = 1.883 ν _d3 = 40.76
r ₅ = 15.23 d ₅ = 3.1
r ₆ = -19.30 d ₆ = 0.9 n _d4 = 1.883 ν _d4 = 40.76
r ₇ = 22.55 d ₇ = 0.6
r ₈ = 27.02 d ₈ = 2.7 n _d5 = 1.92286 ν _d5 = 20.88
r ₉ = -37.27 d ₉ = (variable)
r ₁₀ = ∞ (aperture) d ₁₀ = 0.1
r ₁₁ = 13.51 (aspherical surface) d ₁₁ = 2.1 n _d6 = 1.6935 ν _d6 = 53.21
r ₁₂ = -37.16 d ₁₂ = 0.3
r ₁₃ = 6.88 d ₁₃ = 1.9 n _d7 = 1.497 ν _d7 = 81.54
r ₁₄ = 15.52 d ₁₄ = 0.8 n _d8 = 1.84666 ν _d8 = 23.78
r ₁₅ = 6.28 d ₁₅ = (variable)
r ₁₆ = 14.33 (aspheric surface) d ₁₆ = 1.4 n _d9 = 1.6935 ν _d9 = 53.21
r ₁₇ = 26.77 (aspherical surface) d ₁₇ = (variable)
r ₁₈ = ∞ d ₁₈ = 0.9 n _d10 = 1.54771 ν _d10 = 62.84
r ₁₉ = ∞ d ₁₉ = 0.5
r ₂₀ = ∞ d ₂₀ = 0.5 n _d11 = 1.51633 ν _d11 = 64.14
r ₂₁ = ∞ d ₂₁ = 0.6
r ₂₂ = ∞ (image plane)
Aspheric coefficient 11th surface K = 0.519
A ₄ = -1.14 × 10 ^-4
A ₆ = 4.21 × 10 ^-7
A ₈ = -4.73 × 10 ^-8
A ₁₀ = 8.80 × 10 ^-10
16th surface K = 0
A ₄ = -1.08 × 10 ^-3
A ₆ = -3.68 × 10 ^-5
A ₈ = 8.89 × 10 ^-7
A ₁₀ = -7.24 × 10 ^-8
Surface 17 K = 0
A ₄ = -1.22 × 10 ^-3
A ₆ = -2.94 × 10 ^-5
A ₈ = 4.32 × 10 ^-7
A ₁₀ = -2.89 × 10 ^-8
Zoom data (∞)
WE ST TE
f (mm) 6.5 20.1 62.6
F _NO 2.8 3.5 4.4
d ₃ 1.1 15.4 27.9
d ₉ 35.9 12.6 1.5
d ₁₅ 12.8 14.8 25.1
d ₁₇ 2.0 6.7 4.7.

Example 2
IH = 3.6mm
r ₁ = 24.41 d ₁ = 1.0 n _d1 = 1.90366 ν _d1 = 31.31
r ₂ = 16.58 d ₂ = 4.6 n _d2 = 1.58313 ν _d2 = 59.38
r ₃ = -195.75 d ₃ = (variable)
r ₄ = -75.95 d ₄ = 0.9 n _d3 = 1.883 ν _d3 = 40.76
r ₅ = 15.49 d ₅ = 2.7
r ₆ = -17.31 d ₆ = 0.9 n _d4 = 1.883 ν _d4 = 40.76
r ₇ = 20.77 d ₇ = 0.7
r ₈ = 24.96 d ₈ = 2.4 n _d5 = 1.92286 ν _d5 = 20.88
r ₉ = -39.40 d ₉ = (variable)
r ₁₀ = ∞ (aperture) d ₁₀ = 0.8
r ₁₁ = 15.77 (aspherical surface) d ₁₁ = 2.4 n _d6 = 1.6935 ν _d6 = 53.21
r ₁₂ = -28.03 d ₁₂ = 0.3
r ₁₃ = 6.46 d ₁₃ = 2.8 n _d7 = 1.497 ν _d7 = 81.54
r ₁₄ = 19.27 d ₁₄ = 0.8 n _d8 = 1.78472 ν _d8 = 25.68
r ₁₅ = 5.47 d ₁₅ = (variable)
r ₁₆ = 40.61 (aspherical surface) d ₁₆ = 1.9 n _d9 = 1.6935 ν _d9 = 53.21
r ₁₇ = -29.25 (aspherical surface) d ₁₇ = (variable)
r ₁₈ = ∞ d ₁₈ = 0.9 n _d10 = 1.54771 ν _d10 = 62.84
r ₁₉ = ∞ d ₁₉ = 0.5
r ₂₀ = ∞ d ₂₀ = 0.5 n _d11 = 1.51633 ν _d11 = 64.14
r ₂₁ = ∞ d ₂₁ = 0.6
r ₂₂ = ∞ (image plane)
Aspheric coefficient 11th surface K = 0.519
A ₄ = -9.82 × 10 ^-5
A ₆ = -4.32 × 10 ^-7
A ₈ = 1.54 × 10 ^-8
A ₁₀ = -3.64 × 10 ^-10
16th surface K = 0
A ₄ = -6.23 × 10 ^-4
A ₆ = -2.49 × 10 ^-6
A ₈ = -5.88 × 10 ^-7
A ₁₀ = -1.52 × 10 ^-8
Surface 17 K = 0
A ₄ = -6.63 × 10 ^-4
A ₆ = 3.78 × 10 ^-6
A ₈ = -8.83 × 10 ^-7
A ₁₀ = 4.50 × 10 ^-9
Zoom data (∞)
WE ST TE
f (mm) 6.5 20.1 62.6
F _NO 2.8 3.3 4.4
d ₃ 0.8 13.6 23.2
d ₉ 29.6 8.9 1.5
d ₁₅ 10.2 11.1 28.1
d ₁₇ 3.4 9.4 6.1.

Example 3
IH = 3.6mm
r ₁ = 26.07 d ₁ = 1.0 n _d1 = 1.90366 ν _d1 = 31.31
r ₂ = 17.64 d ₂ = 5.4 n _d2 = 1.58313 ν _d2 = 59.38
r ₃ = -234.53 d ₃ = (variable)
r ₄ = -131.56 d ₄ = 0.9 n _d3 = 1.883 ν _d3 = 40.76
r ₅ = 13.77 d ₅ = 2.2
r ₆ = -36.80 d ₆ = 0.9 n _d4 = 1.883 ν _d4 = 40.76
r ₇ = 14.36 d ₇ = 1.1
r ₈ = 17.74 d ₈ = 2.2 n _d5 = 1.92286 ν _d5 = 20.88
r ₉ = -219.11 d ₉ = (variable)
r ₁₀ = ∞ (aperture) d ₁₀ = 0.8
r ₁₁ = 17.26 (aspherical surface) d ₁₁ = 2.4 n _d6 = 1.6935 ν _d6 = 53.21
r ₁₂ = -23.49 (aspherical surface) d ₁₂ = 0.3
r ₁₃ = 6.09 d ₁₃ = 2.9 n _d7 = 1.497 ν _d7 = 81.54
r ₁₄ = 16.54 d ₁₄ = 0.8 n _d8 = 1.78472 ν _d8 = 25.68
r ₁₅ = 5.07 d ₁₅ = (variable)
r ₁₆ = 19.94 (aspherical surface) d ₁₆ = 2.7 n _d9 = 1.6935 ν _d9 = 53.21
r ₁₇ = -67.41 (aspherical surface) d ₁₇ = (variable)
r ₁₈ = ∞ d ₁₈ = 0.9 n _d10 = 1.54771 ν _d10 = 62.84
r ₁₉ = ∞ d ₁₉ = 0.5
r ₂₀ = ∞ d ₂₀ = 0.5 n _d11 = 1.51633 ν _d11 = 64.14
r ₂₁ = ∞ d ₂₁ = 0.6
r ₂₂ = ∞ (image plane)
Aspheric coefficient 11th surface K = 0.519
A ₄ = -1.09 × 10 ^-4
A ₆ = -2.60 × 10 ^-6
A ₈ = -6.22 × 10 ^-8
A ₁₀ = 3.79 × 10 ^-9
12th surface K = 0
A ₄ = 4.04 × 10 ^-8
A ₆ = -3.45 × 10 ^-6
A ₈ = -2.25 × 10 ^-9
A ₁₀ = 2.87 × 10 ^-9
16th surface K = 0
A ₄ = -4.28 × 10 ^-4
A ₆ = 3.80 × 10 ^-6
A ₈ = -6.83 × 10 ^-7
A ₁₀ = 6.53 × 10 ^-9
Surface 17 K = 0
A ₄ = -5.04 × 10 ^-4
A ₆ = 3.47 × 10 ^-6
A ₈ = -6.12 × 10 ^-7
A ₁₀ = 9.23 × 10 ^-9
Zoom data (∞)
WE ST TE
f (mm) 6.5 20.1 62.6
F _NO 2.8 3.4 4.0
d ₃ 0.8 15.9 26.2
d ₉ 27.2 9.5 1.5
d ₁₅ 9.4 12.5 26.2
d ₁₇ 2.6 6.3 3.9.

Example 4
IH = 3.6mm
r ₁ = 25.58 d ₁ = 1.0 n _d1 = 1.90366 ν _d1 = 31.31
r ₂ = 17.47 d ₂ = 5.1 n _d2 = 1.58313 ν _d2 = 59.38
r ₃ = -342.91 d ₃ = (variable)
r ₄ = -576.31 d ₄ = 0.9 n _d3 = 1.883 ν _d3 = 40.76
r ₅ = 9.13 d ₅ = 2.9
r ₆ = -21.14 d ₆ = 0.9 n _d4 = 1.883 ν _d4 = 40.76
r ₇ = 115.83 d ₇ = 0.6
r ₈ = 25.49 d ₈ = 2.0 n _d5 = 1.92286 ν _d5 = 20.88
r ₉ = -67.34 d ₉ = (variable)
r ₁₀ = ∞ (aperture) d ₁₀ = 0.8
r ₁₁ = 17.57 (aspherical surface) d ₁₁ = 2.4 n _d6 = 1.6935 ν _d6 = 53.21
r ₁₂ = -26.57 (aspherical surface) d ₁₂ = 0.3
r ₁₃ = 5.81 d ₁₃ = 3.2 n _d7 = 1.497 ν _d7 = 81.54
r ₁₄ = 14.50 d ₁₄ = 0.8 n _d8 = 1.78472 ν _d8 = 25.68
r ₁₅ = 4.67 d ₁₅ = (variable)
r ₁₆ = 15.68 (aspherical surface) d ₁₆ = 2.3 n _d9 = 1.6935 ν _d9 = 53.21
r ₁₇ = -653.44 (aspherical surface) d ₁₇ = (variable)
r ₁₈ = ∞ d ₁₈ = 0.9 n _d10 = 1.54771 ν _d10 = 62.84
r ₁₉ = ∞ d ₁₉ = 0.5
r ₂₀ = ∞ d ₂₀ = 0.5 n _d11 = 1.51633 ν _d11 = 64.14
r ₂₁ = ∞ d ₂₁ = 0.6
r ₂₂ = ∞ (image plane)
Aspheric coefficient 11th surface K = 0.519
A ₄ = -9.24 × 10 ^-5
A ₆ = -4.28 × 10 ^-6
A ₈ = 2.11 × 10 ^-7
A ₁₀ = 1.85 × 10 ^-9
12th surface K = 0
A ₄ = 5.00 × 10 ^-6
A ₆ = -3.16 × 10 ^-6
A ₈ = 1.45 × 10 ^-7
A ₁₀ = 3.96 × 10 ^-9
16th surface K = 0
A ₄ = -2.65 × 10 ^-4
A ₆ = 2.63 × 10 ^-6
A ₈ = -4.45 × 10 ^-7
A ₁₀ = 8.52 × 10 ^-10
Surface 17 K = 0
A ₄ = -3.73 × 10 ^-4
A ₆ = 1.05 × 10 ^-5
A ₈ = -9.45 × 10 ^-7
A ₁₀ = 1.30 × 10 ^-8
Zoom data (∞)
WE ST TE
f (mm) 6.5 20.1 62.6
F _NO 2.8 3.4 4.0
d ₃ 0.8 16.9 26.7
d ₉ 26.7 9.2 1.5
d ₁₅ 7.5 10.1 26.4
d ₁₇ 4.0 7.3 3.6.

Example 5
IH = 3.6mm
r ₁ = 28.41 d ₁ = 1.0 n _d1 = 1.92286 ν _d1 = 20.88
r ₂ = 19.57 d ₂ = 4.6 n _d2 = 1.6393 ν _d2 = 44.87
r ₃ = -2730.27 d ₃ = (variable)
r ₄ = -130.63 d ₄ = 0.9 n _d3 = 1.883 ν _d3 = 40.76
r ₅ = 13.93 d ₅ = 2.4
r ₆ = -18.16 d ₆ = 0.9 n _d4 = 1.883 ν _d4 = 40.76
r ₇ = 19.90 d ₇ = 1.0
r ₈ = 26.52 d ₈ = 2.2 n _d5 = 1.92286 ν _d5 = 20.88
r ₉ = -36.36 d ₉ = (variable)
r ₁₀ = ∞ (aperture) d ₁₀ = 0.8
r ₁₁ = 11.21 (aspherical surface) d ₁₁ = 2.8 n _d6 = 1.58913 ν _d6 = 61.14
r ₁₂ = -24.26 (aspherical surface) d ₁₂ = 0.2
r ₁₃ = 7.79 d ₁₃ = 3.3 n _d7 = 1.497 ν _d7 = 81.54
r ₁₄ = -20.65 d ₁₄ = 0.8 n _d8 = 1.64769 ν _d8 = 33.79
r ₁₅ = 5.75 d ₁₅ = (variable)
r ₁₆ = 13.49 (aspherical surface) d ₁₆ = 2.4 n _d9 = 1.58913 ν _d9 = 61.14
r ₁₇ = 469.95 (aspherical surface) d ₁₇ = (variable)
r ₁₈ = ∞ d ₁₈ = 0.9 n _d10 = 1.54771 ν _d10 = 62.84
r ₁₉ = ∞ d ₁₉ = 0.5
r ₂₀ = ∞ d ₂₀ = 0.5 n _d11 = 1.51633 ν _d11 = 64.14
r ₂₁ = ∞ d ₂₁ = 0.6
r ₂₂ = ∞ (image plane)
Aspheric coefficient 11th surface K = 0.519
A ₄ = -5.31 × 10 ^-5
A ₆ = -5.00 × 10 ^-6
A ₈ = 1.33 × 10 ^-7
A ₁₀ = 2.70 × 10 ^-10
12th surface K = 0
A ₄ = 1.26 × 10 ^-4
A ₆ = -5.15 × 10 ^-6
A ₈ = 1.64 × 10 ^-7
A ₁₀ = 2.51 × 10 ^-10
16th surface K = 0
A ₄ = -4.42 × 10 ^-4
A ₆ = 3.82 × 10 ^-6
A ₈ = -7.84 × 10 ^-7
A ₁₀ = -1.75 × 10 ^-9
Surface 17 K = 0
A ₄ = -5.82 × 10 ^-4
A ₆ = 1.50 × 10 ^-5
A ₈ = -1.56 × 10 ^-6
A ₁₀ = 2.12 × 10 ^-8
Zoom data (∞)
WE ST TE
f (mm) 6.5 20.1 62.6
F _NO 2.8 3.4 4.0
d ₃ 0.8 17.3 27.5
d ₉ 25.8 8.5 1.5
d ₁₅ 9.0 10.9 26.6
d ₁₇ 2.3 6.6 2.8.

Example 6
IH = 3.6mm
r ₁ = 28.32 d ₁ = 1.0 n _d1 = 1.84666 ν _d1 = 23.78
r ₂ = 18.21 d ₂ = 5.1 n _d2 = 1.58267 ν _d2 = 46.42
r ₃ = -170.41 d ₃ = (variable)
r ₄ = -45.40 d ₄ = 0.9 n _d3 = 1.883 ν _d3 = 40.76
r ₅ = 11.39 d ₅ = 3.0
r ₆ = -16.65 d ₆ = 0.9 n _d4 = 1.883 ν _d4 = 40.76
r ₇ = 237.30 d ₇ = 0.3
r ₈ = 37.64 d ₈ = 2.1 n _d5 = 1.92286 ν _d5 = 20.88
r ₉ = -30.87 d ₉ = (variable)
r ₁₀ = ∞ (aperture) d ₁₀ = 0.8
r ₁₁ = 16.54 (aspherical surface) d ₁₁ = 2.2 n _d6 = 1.6935 ν _d6 = 53.21
r ₁₂ = -25.07 (aspherical surface) d ₁₂ = 0.2
r ₁₃ = 6.16 d ₁₃ = 3.2 n _d7 = 1.497 ν _d7 = 81.54
r ₁₄ = 16.22 d ₁₄ = 0.8 n _d8 = 1.80518 ν _d8 = 25.42
r ₁₅ = 4.91 d ₁₅ = (variable)
r ₁₆ = 25.09 (aspherical surface) d ₁₆ = 2.1 n _d9 = 1.58913 ν _d9 = 61.14
r ₁₇ = -26.13 (aspherical surface) d ₁₇ = (variable)
r ₁₈ = ∞ d ₁₈ = 0.9 n _d10 = 1.54771 ν _d10 = 62.84
r ₁₉ = ∞ d ₁₉ = 0.5
r ₂₀ = ∞ d ₂₀ = 0.5 n _d11 = 1.51633 ν _d11 = 64.14
r ₂₁ = ∞ d ₂₁ = 0.6
r ₂₂ = ∞ (image plane)
Aspheric coefficient 11th surface K = 0.519
A ₄ = -1.80 × 10 ^-4
A ₆ = -3.29 × 10 ^-6
A ₈ = 1.90 × 10 ^-7
A ₁₀ = -8.64 × 10 ^-9
12th surface K = 0
A ₄ = -8.27 × 10 ^-5
A ₆ = -2.10 × 10 ^-6
A ₈ = 1.13 × 10 ^-7
A ₁₀ = -6.56 × 10 ^-9
16th surface K = 0
A ₄ = -9.20 × 10 ^-4
A ₆ = 2.48 × 10 ^-6
A ₈ = -2.85 × 10 ^-7
A ₁₀ = -4.99 × 10 ^-8
Surface 17 K = 0
A ₄ = -1.08 × 10 ^-3
A ₆ = 2.08 × 10 ^-5
A ₈ = -1.40 × 10 ^-6
A ₁₀ = 7.26 × 10 ^-10
Zoom data (∞)
WE ST TE
f (mm) 6.5 20.1 62.6
F _NO 2.8 3.4 4.0
d ₃ 0.8 17.2 26.9
d ₉ 26.4 9.1 1.5
d ₁₅ 8.0 10.8 26.7
d ₁₇ 3.7 7.3 3.9.

Example 7
IH = 3.6mm
r ₁ = 27.28 d ₁ = 1.0 n _d1 = 1.90366 ν _d1 = 31.31
r ₂ = 18.07 d ₂ = 5.4 n _d2 = 1.58313 ν _d2 = 59.38
r ₃ = -155.43 d ₃ = (variable)
r ₄ = -68.18 d ₄ = 0.9 n _d3 = 1.883 ν _d3 = 40.76
r ₅ = 14.19 d ₅ = 2.1
r ₆ = -21.23 d ₆ = 0.9 n _d4 = 1.883 ν _d4 = 40.76
r ₇ = 22.35 d ₇ = 1.2
r ₈ = 27.68 d ₈ = 2.0 n _d5 = 1.92286 ν _d5 = 20.88
r ₉ = -44.07 d ₉ = (variable)
r ₁₀ = ∞ (aperture) d ₁₀ = 0.8
r ₁₁ = 18.31 (aspherical surface) d ₁₁ = 2.4 n _d6 = 1.6935 ν _d6 = 53.21
r ₁₂ = -23.97 (aspherical surface) d ₁₂ = 0.2
r ₁₃ = 6.11 d ₁₃ = 3.4 n _d7 = 1.497 ν _d7 = 81.54
r ₁₄ = 19.17 d ₁₄ = 0.8 n _d8 = 1.78472 ν _d8 = 25.68
r ₁₅ = 4.99 d ₁₅ = (variable)
r ₁₆ = 16.47 (aspherical surface) d ₁₆ = 1.9 n _d9 = 1.6935 ν _d9 = 53.21
r ₁₇ = -241.03 (aspherical surface) d ₁₇ = (variable)
r ₁₈ = ∞ d ₁₈ = 0.9 n _d10 = 1.54771 ν _d10 = 62.84
r ₁₉ = ∞ d ₁₉ = 0.5
r ₂₀ = ∞ d ₂₀ = 0.5 n _d11 = 1.51633 ν _d11 = 64.14
r ₂₁ = ∞ d ₂₁ = 0.6
r ₂₂ = ∞ (image plane)
Aspheric coefficient 11th surface K = 0.519
A ₄ = -8.04 × 10 ^-5
A ₆ = -4.78 × 10 ^-6
A ₈ = 1.84 × 10 ^-7
A ₁₀ = 1.76 × 10 ^-11
12th surface K = 0
A ₄ = 2.15 × 10 ^-5
A ₆ = -5.10 × 10 ^-6
A ₈ = 2.05 × 10 ^-7
A ₁₀ = -1.06 × 10 ^-10
16th surface K = 0
A ₄ = -4.43 × 10 ^-4
A ₆ = -1.95 × 10 ^-5
A ₈ = 8.33 × 10 ^-7
A ₁₀ = -4.74 × 10 ^-8
Surface 17 K = 0
A ₄ = -5.76 × 10 ^-4
A ₆ = -6.53 × 10 ^-6
A ₈ = -2.10 × 10 ^-7
A ₁₀ = -1.10 × 10 ^-8
Zoom data (∞)
WE ST TE
f (mm) 6.5 20.1 62.6
F _NO 2.8 3.4 4.0
d ₃ 0.8 16.4 26.5
d ₉ 26.8 9.1 1.5
d ₁₅ 8.6 11.1 26.2
d ₁₇ 3.4 7.3 4.2.

Example 8
IH = 3.6mm
r ₁ = 25.93 d ₁ = 1.0 n _d1 = 1.90366 ν _d1 = 31.31
r ₂ = 17.69 d ₂ = 5.7 n _d2 = 1.58313 ν _d2 = 59.38
r ₃ = -312.64 d ₃ = (variable)
r ₄ = -235.08 d ₄ = 0.9 n _d3 = 1.883 ν _d3 = 40.76
r ₅ = 9.25 d ₅ = 3.0
r ₆ = -21.51 d ₆ = 0.9 n _d4 = 1.883 ν _d4 = 40.76
r ₇ = 94.67 d ₇ = 0.5
r ₈ = 25.18 d ₈ = 2.0 n _d5 = 1.92286 ν _d5 = 20.88
r ₉ = -61.09 d ₉ = (variable)
r ₁₀ = ∞ (aperture) d ₁₀ = 0.8
r ₁₁ = 16.74 (aspherical surface) d ₁₁ = 2.3 n _d6 = 1.6935 ν _d6 = 53.21
r ₁₂ = -27.26 (aspherical surface) d ₁₂ = 0.2
r ₁₃ = 5.85 d ₁₃ = 3.1 n _d7 = 1.497 ν _d7 = 81.54
r ₁₄ = 15.30 d ₁₄ = 0.8 n _d8 = 1.78472 ν _d8 = 25.68
r ₁₅ = 4.70 d ₁₅ = (variable)
r ₁₆ = 13.75 (aspherical surface) d ₁₆ = 1.8 n _d9 = 1.6935 ν _d9 = 53.21
r ₁₇ = 127.03 (aspherical surface) d ₁₇ = (variable)
r ₁₈ = ∞ d ₁₈ = 0.9 n _d10 = 1.54771 ν _d10 = 62.84
r ₁₉ = ∞ d ₁₉ = 0.5
r ₂₀ = ∞ d ₂₀ = 0.5 n _d11 = 1.51633 ν _d11 = 64.14
r ₂₁ = ∞ d ₂₁ = 0.6
r ₂₂ = ∞ (image plane)
Aspheric coefficient 11th surface K = 0.519
A ₄ = -8.55 × 10 ^-5
A ₆ = -6.39 × 10 ^-6
A ₈ = 4.07 × 10 ^-7
A ₁₀ = -2.94 × 10 ^-9
12th surface K = 0
A ₄ = 2.03 × 10 ^-5
A ₆ = -6.27 × 10 ^-6
A ₈ = 4.08 × 10 ^-7
A ₁₀ = -2.32 × 10 ^-9
16th surface K = 0
A ₄ = 6.58 × 10 ^-5
A ₆ = -2.74 × 10 ^-5
A ₈ = 1.36 × 10 ^-6
A ₁₀ = -3.53 × 10 ^-8
Surface 17 K = 0
A ₄ = 6.45 × 10 ^-5
A ₆ = -2.94 × 10 ^-5
A ₈ = 1.35 × 10 ^-6
A ₁₀ = -3.35 × 10 ^-8
Zoom data (∞)
WE ST TE
f (mm) 6.5 20.1 62.6
F _NO 2.8 3.4 4.4
d ₃ 0.9 17.0 26.3
d ₉ 27.0 9.1 1.5
d ₁₅ 8.0 10.3 27.2
d ₁₇ 3.8 7.3 3.6.

Example 9
IH = 3.6mm
r ₁ = 27.04 d ₁ = 1.0 n _d1 = 1.90366 ν _d1 = 31.31
r ₂ = 17.99 d ₂ = 5.7 n _d2 = 1.58313 ν _d2 = 59.38
r ₃ = -176.53 d ₃ = (variable)
r ₄ = -82.52 d ₄ = 0.9 n _d3 = 1.883 ν _d3 = 40.76
r ₅ = 9.80 d ₅ = 3.0
r ₆ = -19.43 d ₆ = 0.9 n _d4 = 1.883 ν _d4 = 40.76
r ₇ = 153.20 d ₇ = 0.3
r ₈ = 26.91 d ₈ = 2.3 n _d5 = 1.92286 ν _d5 = 20.88
r ₉ = -46.89 d ₉ = (variable)
r ₁₀ = ∞ (aperture) d ₁₀ = 0.8
r ₁₁ = 16.72 (aspherical surface) d ₁₁ = 2.0 n _d6 = 1.6935 ν _d6 = 53.21
r ₁₂ = -27.19 (aspherical surface) d ₁₂ = 0.2
r ₁₃ = 5.77 d ₁₃ = 3.2 n _d7 = 1.497 ν _d7 = 81.54
r ₁₄ = 14.61 d ₁₄ = 0.8 n _d8 = 1.78472 ν _d8 = 25.68
r ₁₅ = 4.56 d ₁₅ = (variable)
r ₁₆ = 13.75 (aspherical surface) d ₁₆ = 2.4 n _d9 = 1.6935 ν _d9 = 53.21
r ₁₇ = 125.60 (aspherical surface) d ₁₇ = (variable)
r ₁₈ = ∞ d ₁₈ = 0.9 n _d10 = 1.54771 ν _d10 = 62.84
r ₁₉ = ∞ d ₁₉ = 0.5
r ₂₀ = ∞ d ₂₀ = 0.5 n _d11 = 1.51633 ν _d11 = 64.14
r ₂₁ = ∞ d ₂₁ = 0.6
r ₂₂ = ∞ (image plane)
Aspheric coefficient 11th surface K = 0.318
A ₄ = -2.18 × 10 ^-5
A ₆ = -1.54 × 10 ^-5
A ₈ = 6.86 × 10 ^-7
A ₁₀ = -9.56 × 10 ^-9
Surface 12 K = 3.8779
A ₄ = 1.07 × 10 ^-4
A ₆ = -1.61 × 10 ^-5
A ₈ = 7.49 × 10 ^-7
A ₁₀ = -1.06 × 10 ^-8
16th surface K = 0.2738
A ₄ = -1.22 × 10 ^-4
A ₆ = 6.37 × 10 ^-6
A ₈ = -8.03 × 10 ^-7
A ₁₀ = 1.81 × 10 ^-8
Surface 17 K = -39.6532
A ₄ = -1.43 × 10 ^-4
A ₆ = 8.49 × 10 ^-6
A ₈ = -1.08 × 10 ^-6
A ₁₀ = 2.65 × 10 ^-8
Zoom data (∞)
WE ST TE
f (mm) 6.5 20.1 62.6
F _NO 2.9 3.5 4.4
d ₃ 1.1 16.6 26.4
d ₉ 26.5 8.8 1.5
d ₁₅ 7.5 10.3 26.9
d ₁₇ 3.8 7.2 3.4.

Example 10
IH = 3.6mm
r ₁ = 26.18 d ₁ = 1.0 n _d1 = 1.90366 ν _d1 = 31.31
r ₂ = 17.80 d ₂ = 5.4 n _d2 = 1.58313 ν _d2 = 59.38
r ₃ = -249.10 d ₃ = (variable)
r ₄ = -105.86 d ₄ = 0.9 n _d3 = 1.883 ν _d3 = 40.76
r ₅ = 9.81 d ₅ = 3.2
r ₆ = -19.11 d ₆ = 0.9 n _d4 = 1.883 ν _d4 = 40.76
r ₇ = 203.24 d ₇ = 0.3
r ₈ = 29.48 d ₈ = 2.1 n _d5 = 1.92286 ν _d5 = 20.88
r ₉ = -46.62 d ₉ = (variable)
r ₁₀ = ∞ (aperture) d ₁₀ = 0.8
r ₁₁ = 16.60 (aspherical surface) d ₁₁ = 2.3 n _d6 = 1.6935 ν _d6 = 53.21
r ₁₂ = -29.03 (aspherical surface) d ₁₂ = 0.2
r ₁₃ = 5.99 d ₁₃ = 3.2 n _d7 = 1.497 ν _d7 = 81.54
r ₁₄ = 15.62 d ₁₄ = 0.8 n _d8 = 1.78472 ν _d8 = 25.68
r ₁₅ = 4.89 d ₁₅ = (variable)
r ₁₆ = 14.08 (aspherical surface) d ₁₆ = 2.1 n _d9 = 1.6935 ν _d9 = 53.21
r ₁₇ = 138.82 (aspherical surface) d ₁₇ = (variable)
r ₁₈ = ∞ d ₁₈ = 0.9 n _d10 = 1.54771 ν _d10 = 62.84
r ₁₉ = ∞ d ₁₉ = 0.5
r ₂₀ = ∞ d ₂₀ = 0.5 n _d11 = 1.51633 ν _d11 = 64.14
r ₂₁ = ∞ d ₂₁ = 0.6
r ₂₂ = ∞ (image plane)
Aspheric coefficient 11th surface K = 0.519
A ₄ = -7.45 × 10 ^-6
A ₆ = -8.82 × 10 ^-6
A ₈ = 5.88 × 10 ^-7
A ₁₀ = -4.76 × 10 ^-9
12th surface K = 0
A ₄ = 1.02 × 10 ^-4
A ₆ = -8.89 × 10 ^-6
A ₈ = 5.92 × 10 ^-7
A ₁₀ = -3.59 × 10 ^-9
16th surface K = 0
A ₄ = -1.80 × 10 ^-4
A ₆ = -8.60 × 10 ^-6
A ₈ = 2.70 × 10 ^-7
A ₁₀ = -1.54 × 10 ^-8
Surface 17 K = 0
A ₄ = -2.56 × 10 ^-4
A ₆ = -3.77 × 10 ^-6
A ₈ = -7.30 × 10 ^-8
A ₁₀ = -6.62 × 10 ^-9
Zoom data (∞)
WE ST TE
f (mm) 6.5 20.1 62.6
F _NO 2.8 3.4 4.4
d ₃ 1.0 16.5 26.1
d ₉ 27.2 8.9 1.5
d ₁₅ 8.3 10.7 27.4
d ₁₇ 3.6 7.3 3.4.

Example 11
IH = 3.6mm
r ₁ = 27.05 d ₁ = 1.0 n _d1 = 1.90366 ν _d1 = 31.31
r ₂ = 18.00 d ₂ = 5.7 n _d2 = 1.58313 ν _d2 = 59.38
r ₃ = -176.56 d ₃ = (variable)
r ₄ = -81.93 d ₄ = 0.9 n _d3 = 1.883 ν _d3 = 40.76
r ₅ = 9.81 d ₅ = 3.0
r ₆ = -19.38 d ₆ = 0.9 n _d4 = 1.883 ν _d4 = 40.76
r ₇ = 153.31 d ₇ = 0.3
r ₈ = 26.90 d ₈ = 2.4 n _d5 = 1.92286 ν _d5 = 20.88
r ₉ = -46.81 d ₉ = (variable)
r ₁₀ = ∞ (aperture) d ₁₀ = 0.8
r ₁₁ = 16.77 (aspherical surface) d ₁₁ = 2.0 n _d6 = 1.6935 ν _d6 = 53.21
r ₁₂ = -27.11 (aspherical surface) d ₁₂ = 0.2
r ₁₃ = 5.75 d ₁₃ = 3.2 n _d7 = 1.497 ν _d7 = 81.54
r ₁₄ = 14.61 d ₁₄ = 0.8 n _d8 = 1.78472 ν _d8 = 25.68
r ₁₅ = 4.55 d ₁₅ = (variable)
r ₁₆ = 13.67 (aspherical surface) d ₁₆ = 2.4 n _d9 = 1.6935 ν _d9 = 53.21
r ₁₇ = 118.93 (aspherical surface) d ₁₇ = (variable)
r ₁₈ = ∞ d ₁₈ = 0.9 n _d10 = 1.54771 ν _d10 = 62.84
r ₁₉ = ∞ d ₁₉ = 0.5
r ₂₀ = ∞ d ₂₀ = 0.5 n _d11 = 1.51633 ν _d11 = 64.14
r ₂₁ = ∞ d ₂₁ = 0.6
r ₂₂ = ∞ (image plane)
Aspheric coefficient 11th surface K = 0.318
A ₄ = -2.19 × 10 ^-5
A ₆ = -1.54 × 10 ^-5
A ₈ = 6.85 × 10 ^-7
A ₁₀ = -9.65 × 10 ^-9
Surface 12 K = 3.8779
A ₄ = 1.08 × 10 ^-4
A ₆ = -1.61 × 10 ^-5
A ₈ = 7.49 × 10 ^-7
A ₁₀ = -1.07 × 10 ^-8
16th surface K = 0.2738
A ₄ = -1.22 × 10 ^-4
A ₆ = 6.35 × 10 ^-6
A ₈ = -8.03 × 10 ^-7
A ₁₀ = 1.79 × 10 ^-8
Surface 17 K = -39.6532
A ₄ = -1.43 × 10 ^-4
A ₆ = 8.51 × 10 ^-6
A ₈ = -1.08 × 10 ^-6
A ₁₀ = 2.63 × 10 ^-8
Zoom data (∞)
WE ST TE
f (mm) 6.4 20.1 62.6
F _NO 2.9 3.5 4.4
d ₃ 1.1 16.6 26.4
d ₉ 26.5 8.8 1.5
d ₁₅ 7.5 10.3 26.9
d ₁₇ 3.8 7.2 3.4.

  Aberration diagrams at the time of focusing on an object point at infinity in Examples 1 to 11 are shown in FIGS. In these aberration diagrams, (a) is the wide angle end, (b) is the intermediate state, (c) is the spherical aberration (SA), astigmatism (AS), distortion (DT), and lateral chromatic aberration (CC) at the telephoto end. ). In each figure, “FIY” indicates the maximum image height.

  Next, the angle of view and the values of conditional expressions (1) to (27) in each of the above embodiments are shown.

Example conditional expression 1 2 3 4 5 6
(1) 0.39 0.65 0.68 0.72 0.64 0.70
(2) -14.02 -20.12 -14.09 -10.33 -17.21 -17.47
(3) 3.19 3.09 3.31 3.30 3.14 3.21
(4) 0.89 0.77 0.84 0.85 0.87 0.85
(5) -0.19 -0.17 -0.17 -0.18 -0.17 -0.18
(6) 0.26 0.26 0.25 0.25 0.24 0.25
(7) 0.68 0.40 0.36 0.35 0.38 0.35
(8) 1.31 1.33 1.33 1.33 1.33 1.33
(9) 1.16 2.31 2.78 2.96 3.16 3.10
(10) 9.91 8.32 8.40 8.40 8.39 8.39
(11) 0.99 0.85 1.03 1.14 1.00 1.05
(12) 0.89 0.87 1.00 0.94 0.87 0.95
(13) 0.13 0.12 0.12 0.12 0.12 0.11
(14) 0.08 0.10 0.10 0.11 0.11 0.10
(15) 0.33 0.34 0.37 0.36 0.36 0.35
(16) 1.90 1.90 1.90 1.90 1.92 1.85
.

Example conditional expression 7 8 9 10 11
(1) 0.70 0.72 0.72 0.71 0.72
(2) -16.29 -10.71 -12.47 -12.73 -12.51
(3) 3.34 3.20 3.16 3.20 3.16
(4) 0.83 0.85 0.84 0.84 0.84
(5) -0.17 -0.18 -0.18 -0.18 -0.18
(6) 0.25 0.25 0.25 0.25 0.25
(7) 0.36 0.35 0.35 0.36 0.35
(8) 1.33 1.33 1.33 1.33 1.33
(9) 2.92 2.93 2.99 2.86 2.99
(10) 8.39 8.39 8.34 8.39 8.34
(11) 1.08 1.05 1.08 1.05 1.08
(12) 1.00 1.04 1.03 1.00 1.04
(13) 0.11 0.12 0.12 0.12 0.12
(14) 0.11 0.10 0.10 0.10 0.10
(15) 0.36 0.35 0.36 0.36 0.36
(16) 1.90 1.90 1.90 1.90 1.90
.

  23 to 25 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. FIG. 23 is a front perspective view showing the appearance of the digital camera 40, FIG. 24 is a rear front view thereof, and FIG. 25 is a schematic perspective plan view showing the configuration of the digital camera 40. However, in FIGS. 23 and 25, the photographing optical system 41 is not retracted. In this example, the digital camera 40 includes a photographing optical system 41 having a photographing optical path 42, a finder optical system 43 having a finder optical path 44, a shutter button 45, a flash 46, a liquid crystal display monitor 47, a focal length change button 61, When the photographing optical system 41 is retracted, including the setting change switch 62, the photographing optical system 41, the finder optical system 43, and the flash 46 are covered with the cover 60 by sliding the cover 60. 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. 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 of the CCD 49 via the low-pass filter F and the cover glass C subjected to IR cut coating. 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. Further, the processing means 51 is connected to a recording means 52 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 configured to perform recording / writing electronically using a floppy disk, 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 two prisms, and includes a zoom optical system whose focal length changes in conjunction with the zoom lens of the photographing optical system 41. The object image formed by the finder objective optical system 53 is formed on the field frame 57 of the erecting prism 55 that is an image erecting member. Behind the erecting prism 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.

  The digital camera 40 configured in this manner has a high performance because the imaging optical system 41 is extremely thin when retracted and the imaging performance is extremely stable in the entire zoom range with high zoom ratio. -Miniaturization can be realized.

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. 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. It is a front perspective view which shows the external appearance of the digital camera by this invention. FIG. 24 is a rear perspective view of the digital camera of FIG. 23. It is sectional drawing of the digital camera of FIG.

Explanation of symbols

G1 ... 1st lens group G2 ... 2nd lens group G3 ... 3rd lens group G4 ... 4th lens group S ... Aperture stop F ... Low pass filter C ... Cover glass I ... Image plane E ... Observer eyeball 40 ... Digital camera 41 ... Optical optical system 42 ... Optical optical path 43 ... finder optical system 44 ... optical path for finder 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 ... Viewfinder objective optical system 55 ... Erect prism 57 ... Field frame 59 ... Eyepiece optical system 60 ... Cover 61 ... Focal length change button 62 ... Setting change switch

Claims (20)

In order from the object side, a four-group configuration comprising a first lens unit having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a fourth lens group having a positive refractive power. A zoom lens,
When zooming from the wide-angle end to the telephoto end,
An air gap between the first lens group and the second lens group is increased;
An air gap between the second lens group and the third lens group is reduced;
In order to increase the air gap between the third lens group and the fourth lens group,
Each of the first lens group, the second lens group, the third lens group, and the fourth lens group moves,
The first lens group includes one negative lens and one positive lens in order from the object side.
The second lens group includes two negative lenses and one positive lens in order from the object side.
The third lens group includes four or less lenses.
A zoom lens satisfying the following conditional expression:
0.3 <f ₃ / f ₄ <1.4 (1)
Where f _{3 is} the focal length of the third lens group,
f ₄ : focal length of the fourth lens group,
It is. In order from the object side, a four-group configuration comprising a first lens unit having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a fourth lens group having a positive refractive power. A zoom lens,
When zooming from the wide-angle end to the telephoto end,
An air gap between the first lens group and the second lens group is increased;
An air gap between the second lens group and the third lens group is reduced;
In order to increase the air gap between the third lens group and the fourth lens group,
Each of the first lens group, the second lens group, the third lens group, and the fourth lens group moves,
The first lens group includes two or less lenses,
The second lens group includes two negative lenses and one positive lens in order from the object side.
The third lens group includes four or less lenses.
A zoom lens satisfying the following conditional expression:
−23 <dt _0.5dw <−6.0 (2)
However, dt _0.5dw is the distortion of the maximum image height at the wide-angle end, and the unit is%. In order from the object side, a four-group configuration comprising a first lens unit having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a fourth lens group having a positive refractive power. A zoom lens,
When zooming from the wide-angle end to the telephoto end,
An air gap between the first lens group and the second lens group is increased;
An air gap between the second lens group and the third lens group is reduced;
In order to increase the air gap between the third lens group and the fourth lens group,
Each of the first lens group, the second lens group, the third lens group, and the fourth lens group moves,
The first lens group includes two or less lenses,
The second lens group is composed of a biconcave lens, a negative lens, and a positive lens in order from the object side with an air gap in between.
The zoom lens according to claim 3, wherein the third lens group includes four or less lenses. 4. The zoom according to claim 3, wherein the second lens group includes the biconcave lens, the biconcave lens as the negative lens, and the positive lens in order from the object side with an air gap therebetween. lens. In order from the object side, a four-group configuration comprising a first lens unit having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a fourth lens group having a positive refractive power. A zoom lens,
When zooming from the wide-angle end to the telephoto end,
An air gap between the first lens group and the second lens group is increased;
An air gap between the second lens group and the third lens group is reduced;
In order to increase the air gap between the third lens group and the fourth lens group,
Each of the first lens group, the second lens group, the third lens group, and the fourth lens group moves,
The first lens group includes two or less lenses,
The second lens group includes two negative lenses and one positive lens in order from the object side.
The third lens group includes four or less lenses.
A zoom lens satisfying the following conditional expression:
2.4 <(β _2t / β _2w ) <5.7 (3)
Where β _2t : lateral magnification of the second lens group at the telephoto end,
β _2w : lateral magnification of the second lens group at the wide-angle end,
It is. In order from the object side, a four-group configuration comprising a first lens unit having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a fourth lens group having a positive refractive power. A zoom lens,
When zooming from the wide-angle end to the telephoto end,
An air gap between the first lens group and the second lens group is increased;
An air gap between the second lens group and the third lens group is reduced;
In order to increase the air gap between the third lens group and the fourth lens group,
Each of the first lens group, the second lens group, the third lens group, and the fourth lens group moves,
The first lens group includes two or less lenses,
The second lens group includes two negative lenses and one positive lens in order from the object side.
The third lens group includes four or less lenses.
A zoom lens satisfying the following conditional expression:
_{0.01 <f 1 / f t <} 1.00 ··· (4)
Where f _{1 is} the focal length of the first lens group,
f _t : focal length of the entire zoom lens system at the telephoto end,
It is. In order from the object side, a four-group configuration comprising a first lens unit having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a fourth lens group having a positive refractive power. A zoom lens,
When zooming from the wide-angle end to the telephoto end,
An air gap between the first lens group and the second lens group is increased;
An air gap between the second lens group and the third lens group is reduced;
In order to increase the air gap between the third lens group and the fourth lens group,
Each of the first lens group, the second lens group, the third lens group, and the fourth lens group moves,
The first lens group includes one negative lens and one positive lens in order from the object side.
The second lens group includes a biconcave lens, a negative lens, and a positive lens in order from the object side and sequentially from the object side, with an air gap therebetween.
The third lens group includes four or less lenses.
A zoom lens satisfying the following conditional expression:
0.3 <f ₃ / f ₄ <1.4 (1)
−23 <dt _0.5dw <−6.0 (2)
2.4 <(β _2t / β _2w ) <5.7 (3)
_{0.01 <f 1 / f t <} 1.00 ··· (4)
Where f _{1 is} the focal length of the first lens group,
f ₃ : focal length of the third lens group,
f ₄ : focal length of the fourth lens group,
f _t : focal length of the entire zoom lens system at the telephoto end,
dt _0.5dw : Maximum image height distortion at the wide-angle end. The unit is%.
β _2t : lateral magnification of the second lens group at the telephoto end,
β _2w : lateral magnification of the second lens group at the wide-angle end,
It is. The zoom lens according to claim 1, wherein the following conditional expression is satisfied.
0.01 <| f ₂ / f _t | <0.2 (5)
Where f _{2 is} the focal length of the second lens group,
f _t : 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.
0.01 <f ₃ / _ft <0.3 (6)
Where f _{3 is} the focal length of the third lens group,
f _t : 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 9, wherein the following conditional expression is satisfied.
0.01 <f ₄ / _ft <0.55 (7)
Where f _{4 is} the focal length of the fourth lens group,
f _t : 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.
0.5 <L _t / f _t <1.5 (8)
Where L _t is the total length on the optical axis from the entrance surface of the zoom lens to the image surface at the telephoto end,
f _t : 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.
2.20 <Δ _t1g / f _w <5.0 (9)
Where Δ _t1g is the difference between the position of the first lens group at the wide-angle end and the position at the telephoto end,
f _w : focal length of the entire zoom lens system at the wide angle end,
It is. The zoom lens according to claim 1, wherein the following conditional expression is satisfied.
8.0 <(D _1t + D _2w ) / f _w <10.0 (10)
Where D _1t is the air space between the first lens group and the second lens group at the telephoto end,
D _2w : the air space between the second lens group and the third lens group at the wide-angle end,
f _w : focal length of the entire zoom lens system at the wide angle end,
It is. The zoom lens according to claim 1, wherein the following conditional expression is satisfied.
1.05 <(β _2t / β _2w ) / (β _3t / β _3w ) <5.7 (11)
Where β _2t : lateral magnification of the second lens group at the telephoto end,
β _2w : lateral magnification of the second lens group at the wide-angle end,
β _3t : Lateral magnification of the third lens group at the telephoto end,
β _3w : lateral magnification of the third lens unit at the wide-angle end,
It is. The zoom lens according to claim 1, wherein the following conditional expression is satisfied.
0.82 <Σd _1g / f _w <1.5 (12)
Where Σd _1g is the thickness of the first lens group on the optical axis,
f _w : focal length of the entire zoom lens system at the wide angle end,
It is. The zoom lens according to claim 1, wherein the following conditional expression is satisfied.
_{0.05 <Σd 2g / f t <} 0.15 ··· (13)
Where Σd _2g : thickness of the second lens group on the optical axis,
f _t : 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.
_{0.05 <Σd 3g / f t <} 0.12 ··· (14)
Where Σd _3g is the thickness of the third lens group on the optical axis,
f _t : 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.
_{0.1 <Σd / f t <0.43} ··· (15)
Where Σd: the sum of the thickness on the optical axis of each of the first lens group, the second lens group, the third lens group, and the fourth lens group,
f _t : focal length of the entire zoom lens system at the telephoto end,
It is. 19. The zoom lens according to claim 1, wherein only one negative lens is included in the first lens group, and the negative lens satisfies the following conditional expression. 19.
n _d ≧ 1.90 (16)
Where n _d is the refractive index of the negative lens material of the first lens group at the d-line,
It is. An image pickup apparatus comprising: the zoom lens according to claim 1; and an image pickup element that is disposed on an image side of the zoom lens and converts an optical image into an electric signal.

Images