JP2011107188A - Image forming optical system and electronic imaging device equipped with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming optical system capable of improving the specifications centered on shortening of its whole length and achievement of high zoom ratio, improving the performance coping with increase of the number of pixels (aberration correction), and achieving thin innermost depth zooming. <P>SOLUTION: The image forming optical system includes a group of positive lenses G1, a group of negative lenses G2 movable to change variable power, and a group of rear part lenses GR having positive refractive power always on the whole and composed of three or four groups of sub-lenses having changing distance on optical axis therebetween to change variable power which are arranged in this order from an object side. The group of lenses G1 includes a group of sub-lenses G11 having a configuration constituted by a negative lens component and a prism or a configuration constituted by a prism having negative refractive power and a group of sub-lenses G12 constituted by a junction lens component including a lens LA and a lens LB and a positive lens LC having higher refractive power than that of two lenses LA and LB and having positive refractive power. A junction plane of the lenses LA and LB is aspheric and satisfies the predetermined expression. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an imaging optical system and an electronic imaging apparatus having the same.

  Digital cameras have achieved practical levels in terms of increasing the number of pixels (higher image quality) and reducing the size and thickness, replacing the silver salt 35 mm film camera both functionally and commercially. Therefore, as one of the next evolution directions, there is a strong demand for further increase in the number of pixels as the optical specifications improve. The improvement of the optical specifications means that the optical system has a high zoom ratio, a wide angle, and a large aperture ratio that are small and thin as they are.

  As an imaging optical system that has been used so far as being suitable for reducing the thickness of an optical system, for example, there are imaging optical systems described in Patent Documents 1 and 2. In these imaging optical systems, a reflective optical element (hereinafter simply referred to as a reflective optical element) for bending an optical path is used for the lens group closest to the object side. The specifications of these imaging optical systems are such that the zoom ratio is about 3 and the half angle of view at the wide angle end is about 33 degrees. On the other hand, when the reflecting optical element is moved at the time of zooming, the optical axis of the optical system moves. As a result, the zoom barrel is mechanically complicated. Therefore, in the imaging optical systems described in Patent Documents 1 and 2, the lens group closest to the object side is fixed.

  The imaging optical systems described in Patent Documents 1 and 2 are based on a zoom optical system as described in Patent Documents 3 and 4, for example, and have a configuration in which a reflective optical element is inserted into the first lens group. . Such a zoom optical system has, in order from the object side, a first lens unit that has positive refractive power and is fixed at the time of zooming, and an image that has negative refractive power when zooming from the wide-angle end to the telephoto end. A second lens group that moves to the side, a third lens group that has positive refractive power and moves to the object side when zooming from the wide-angle end to the telephoto end, and a fourth lens group that has positive refractive power Configured.

  In general, when a reflective optical element is inserted into the lens group closest to the object side, the entrance pupil position tends to be deep. Furthermore, at the same time, the total length after the second lens group is easily extended. If these are to be solved by paraxial arrangement, it will be difficult to correct off-axis aberrations such as coma and curvature of field, which is disadvantageous in terms of zoom ratio.

  Therefore, in a zoom optical system in which a reflective optical element is inserted in the lens group closest to the object side, it is difficult to obtain a zoom ratio of about 5 times while maintaining a small size. Incidentally, among the above-mentioned patent documents, the imaging optical system described in Patent document 1 does not recommend that the zoom ratio exceeds 5.5 times.

  On the other hand, as a zoom method strong against high magnification, for example, there are methods used for home video cameras as described in Patent Documents 5, 6, and 7. The optical system used in this zoom system is, in order from the object side, a first lens unit that has a positive refractive power and is fixed at the time of zooming, and has a negative refractive power when zooming from the wide angle end to the telephoto end. A second lens group that moves to the image side, a third lens group that has positive refractive power and is fixed at the time of zooming, and a positive refractive power that moves on the optical axis at the time of zooming and focusing. It is composed of a fourth lens group. Based on the optical system having this configuration, it is conceivable to configure the optical system by inserting a reflective optical element into the lens group closest to the object side. As such an example, there is an optical system described in Patent Document 8, for example.

  As described above, when a reflective optical element is inserted into the lens group closest to the object side, it becomes difficult to correct aberrations while maintaining a small size. When the zoom ratio is 5 times or more, it is difficult to correct high-order chromatic aberrations particularly on the field curvature and the telephoto side.

  In Patent Document 8 described above, the curvature of field is favorably corrected by adding a fifth lens group having a function of correcting curvature of field to the image side of the fourth lens group. Here, higher-order chromatic aberration, that is, higher-order components (color distortion aberration) relating to image height of spherical spherical aberration, color coma, and lateral chromatic aberration are higher-order with respect to a reference wavelength (for example, d-line... 587.56 nm). This is caused by a complicated entanglement between the aberration source and material dispersion. In general, correcting these results at the expense of correcting aberrations relative to the reference wavelength and correcting paraxial chromatic aberration. Moreover, the correction becomes more difficult as the overall length becomes smaller.

  Further, as the angle of view is further advanced, these aberrations at the periphery of the screen become remarkable. As technical means for solving this, there are optical systems described in Patent Documents 9 and 10.

JP 2003-302576 A JP 2004-264343 A JP-A-10-62687 Japanese Patent Laid-Open No. 11-258507 Japanese Patent Laid-Open No. 62-178717 JP-A-63-29718 Japanese Unexamined Patent Publication No. 63-123209 JP 2008-83125 A JP 2008-108712 A JP 2008-191286 A

  As described above, in the conventional optical system, it is difficult to correct aberrations satisfactorily while improving specifications centering on shortening the overall length of the optical system and increasing the zoom ratio.

  The present invention has been made in view of the above, and an imaging optical system in which aberrations are favorably corrected even when the overall length of the optical system is shortened or the zoom ratio is increased, and the imaging optical system An object of the present invention is to provide an imaging apparatus including the above.

In order to solve the above-described problems and achieve the object, the imaging optical system of the present invention, in order from the object side, a lens group G1 having a positive refractive power, a lens group G2 having a negative refractive power, An imaging optical system composed of a rear lens group GR that always has positive refractive power as a whole, and a lens group G1 is composed of a sub lens group G11 and a sub lens group G12, and the lens group G2 is The rear lens group GR is movable at the time of zooming, and the rear lens group GR is composed of three or four sub lens groups whose mutual optical axis distances change at the time of zooming, and the sub lens group G11 has a negative refractive power. A lens component and a prism for bending the optical path, or a prism having a negative refractive power and a prism for bending the optical path. The sub lens group G12 has a positive refractive power, and the lens LA Lens component and lens LB, positive lens C, the cemented surface between the lens LA and the lens LB is aspheric, and the positive lens LC has a refractive power stronger than that of the lens LA and the lens LB, and the following conditional expression (1 ) Is satisfied.
0.008 <{1 / νd (12A)} − {1 / νd (12B)} (1)
here,
νd (12A) is the Abbe number (nd (12A) −1) / (nF (12A) −nC (12A)) of the lens LA,
nd (12A), nC (12A), nF (12A), and ng (12A) are the refractive indexes of the d-line, C-line, F-line, and g-line of the lens LA, respectively.
νd (12B) is the Abbe number (nd (12B) −1) / (nF (12B) −nC (12B)) of the lens LB,
nd (12B), nC (12B), nF (12B), and ng (12B) are the refractive indices of the d-line, C-line, F-line, and g-line of the lens LB, respectively.
It is.

The electronic image pickup apparatus of the present invention includes the above-described imaging optical system and an electronic image pickup element. The optical axis direction is z, the coordinate axis is h perpendicular to the optical axis, and R is a spherical component light. The radius of curvature on the axis, K is a conic constant, A ₄ , A ₆ , A ₈ , A ₁₀ ... Are aspheric coefficients, and the shape of the aspheric surface is expressed by the following equation (8):
z = (h ² / R) / {1+ [1- (1 + K) (h / R) ² ] ^1/2 }
+ A ₄ h ⁴ + A ₆ h ⁶ + A ₈ h ⁸ + A ₁₀ h ¹⁰ (8)
When the deviation amount is expressed by the following formula (9),
Δz = z−h ² / R {1+ (1−h ² / R ² ) ^1/2 } (9)
The following conditional expression (10) is satisfied.
When R _12A ≧ 0
-5.0e-2 <P (LA) / y 10 <0 < However, h = 2.5a> ··· (10 )
here,
P (LA) is a parameter related to the shape and dispersion of the joint surface, and is represented by the following equation:
P (LA) = Δz _12A (h) ・ (1 / νd (12A) −1 / νd (12B))
z _12A is the shape of the joint surface, the shape according to formula (8),
Δz _12A (h) is the amount of deviation of the joint surface, and the amount of deviation according to equation (9),
R _12A is the paraxial radius of curvature of the joint surface,
a is an amount according to the following conditional expression (11),
a = (y ₁₀ ) ² · log ₁₀ γ / fw (11)
Both air contact surfaces may be spherical,
y ₁₀ is the distance (maximum image height) from the center to the farthest point in the effective imaging plane (in the plane where imaging is possible) of the electronic imaging device arranged in the vicinity of the imaging position of the imaging optical system;
fw is the focal length of the entire system at the wide angle end of the imaging optical system,
γ is the imaging ratio (total focal length at the telephoto end / total focal length at the wide angle end),
Also, since the top of each surface is the origin, z (0) = 0 is always set.
It is.

Another electronic imaging apparatus of the present invention processes image data obtained by capturing an image formed through the imaging optical system, the electronic imaging element, and the imaging optical system with the electronic imaging element. And image processing means for outputting the image data with the image shape changed, and the imaging optical system satisfies the following conditional expression (23) when focusing on an object point at infinity: .
0.85 <y ₀₇ / (fw · tan ω _07w ) <0.97 (23)
here,
y ₀₇ The y ₀₇ = 0.7 · y ₁₀ when the distance to the point farthest from the center (maximum image height) was y ₁₀ at effective imaging plane of the electronic imaging device (imaging possible in-plane),
ω _07w is an angle with respect to the optical axis in the object direction corresponding to the image point connecting from the center on the imaging surface at the wide angle end to the position of y ₀₇ ,
fw is the focal length of the entire imaging optical system at the wide-angle end,
It is.

  According to the present invention, it is possible to realize an imaging optical system in which aberration is favorably corrected and an imaging apparatus including the imaging optical system even when the overall length of the optical system is shortened or the zoom ratio is increased. In addition, an optical performance sufficient to withstand the increase in the number of pixels can be secured (aberration correction).

(A) of the zoom lens according to Example 1 of the present invention is a cross-sectional view along the optical axis showing an optical configuration at the time of focusing on an object point at infinity at the wide-angle end, (b) at the middle, and (c) at the telephoto end. is there. FIG. 2 is a diagram illustrating spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 1 is focused on an object point at infinity, where (a) is a wide angle end, (b) is an intermediate, and (c). Indicates the state at the telephoto end. (A) of the zoom lens according to Example 2 of the present invention is a cross-sectional view along the optical axis showing an optical configuration at the time of focusing on an object point at infinity at the wide-angle end, (b) at the middle, and (c) at the telephoto end. is there. FIG. 6 is a diagram illustrating spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 2 is focused on an object point at infinity, where (a) is a wide-angle end, (b) is a middle, and (c). Indicates the state at the telephoto end. (A) of the zoom lens according to Example 3 of the present invention is a cross-sectional view along the optical axis showing an optical configuration at the time of focusing on an object point at infinity at the wide-angle end, (b) at the middle, and (c) at the telephoto end. is there. FIG. 6 is a diagram illustrating spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 3 is focused on an object point at infinity, (a) is a wide-angle end, (b) is an intermediate, (c) Indicates the state at the telephoto end. (A) of the zoom lens according to Example 4 of the present invention is a cross-sectional view along the optical axis showing an optical configuration at the time of focusing on an object point at infinity at the wide-angle end, (b) at the middle, and (c) at the telephoto end. is there. FIG. 10 is a diagram illustrating spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 4 is focused on an object point at infinity, where (a) is a wide angle end, (b) is an intermediate, and (c). Indicates the state at the telephoto end. (A) of the zoom lens according to Example 5 of the present invention is a cross-sectional view along the optical axis showing the optical configuration at the time of focusing on an object point at infinity at the wide-angle end, (b) at the middle, and (c) at the telephoto end. is there. FIG. 10 is a diagram illustrating spherical aberration, astigmatism, distortion, and lateral chromatic aberration when the zoom lens according to Example 5 is focused on an object point at infinity, where (a) is a wide angle end, (b) is an intermediate, and (c). Indicates the state at the telephoto end. (A) of the zoom lens according to Example 6 of the present invention is a cross-sectional view along the optical axis showing an optical configuration at the time of focusing on an object point at infinity at the wide-angle end, (b) at the middle, and (c) at the telephoto end. is there. FIG. 8 is a diagram illustrating spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 6 is focused on an object point at infinity, where (a) is a wide angle end, (b) is an intermediate, and (c). Indicates the state at the telephoto end. (A) of the zoom lens according to Example 7 of the present invention is a cross-sectional view along the optical axis showing an optical configuration at the time of focusing on an object point at infinity at the wide-angle end, (b) at the middle, and (c) at the telephoto end. is there. FIG. 9 is a diagram illustrating spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 7 is focused on an object point at infinity, where (a) is a wide angle end, (b) is an intermediate, and (c). Indicates the state at the telephoto end. (A) of the zoom lens according to Example 8 of the present invention is a cross-sectional view along the optical axis showing an optical configuration at the time of focusing on an object point at infinity at the wide-angle end, (b) at the middle, and (c) at the telephoto end. is there. FIG. 10 is a diagram illustrating spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 8 is focused on an object point at infinity, where (a) is a wide angle end, (b) is an intermediate, and (c). Indicates the state at the telephoto end. (A) of the zoom lens according to Example 9 of the present invention is a cross-sectional view along the optical axis showing an optical configuration at the time of focusing on an object point at infinity at the wide-angle end, (b) at the middle, and (c) at the telephoto end. is there. FIG. 10 is a diagram illustrating spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 9 is focused on an object point at infinity, where (a) is a wide-angle end, (b) is an intermediate, and (c). Indicates the state at the telephoto end. (A) of the zoom lens according to Example 10 of the present invention is a cross-sectional view along the optical axis showing the optical configuration at the time of focusing on an object point at infinity at the wide-angle end, (b) at the middle, and (c) at the telephoto end. is there. FIG. 10 is a diagram illustrating spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 10 is focused on an object point at infinity, where (a) is a wide-angle end, (b) is an intermediate, and (c). Indicates the state at the telephoto end. It is a front perspective view which shows the external appearance of the digital camera 40 incorporating the zoom optical system by this invention. 2 is a rear perspective view of the digital camera 40. FIG. 2 is a cross-sectional view showing an optical configuration of a digital camera 40. FIG. 1 is a front perspective view of a state in which a cover of a personal computer 300 which is an example of an information processing apparatus in which a zoom optical system of the present invention is built as an objective optical system is opened. FIG. 2 is a cross-sectional view of a photographing optical system 303 of a personal computer 300. FIG. 2 is a side view of a personal computer 300. FIG. 1A and 1B are views showing a mobile phone as an example of an information processing apparatus in which the zoom optical system of the present invention is built in as a photographing optical system, where FIG. 1A is a front view of the mobile phone 400, FIG. FIG. 6 is a cross-sectional view of the photographing optical system 405.

  Hereinafter, an example in which the imaging optical system of the present embodiment is applied to a zoom optical system will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. Prior to the description of the examples, the effects of the imaging optical system of the present embodiment will be described. In the following description, a lens having a positive paraxial focal length is defined as a positive lens, and a lens having a negative paraxial focal length is defined as a negative lens.

  The imaging optical system according to the present embodiment includes, in order from the object side, a lens group G1 having a positive refractive power, a lens group G2 having a negative refractive power, and a rear lens group GR that always has a positive refractive power as a whole. The lens group G1 is composed of a sub lens group G11 and a sub lens group G12, the lens group G2 is movable during zooming, and the rear lens group GR is It consists of three or four sub-lens groups whose mutual optical axis distances change at the time of magnification, and the sub-lens group G11 is composed of a lens component having negative refractive power and a prism for bending the optical path, or negative The sub lens group G12 has a positive refractive power, and includes a cemented lens component of the lens LA and the lens LB, and a positive lens LC. The joint surface between the lens LA and the lens LB is aspheric, The positive lens LC has a refractive power stronger than those of the lens LA and the lens LB.

The zoom optical system according to the present embodiment satisfies the following condition (1).
0.008 <{1 / νd (12A)} − {1 / νd (12B)} (1)
here,
νd (12A) is the Abbe number (nd (12A) −1) / (nF (12A) −nC (12A)) of the lens LA,
nd (12A), nC (12A), nF (12A), and ng (12A) are the refractive indices of the d-line, C-line, F-line, and g-line of the lens LA, respectively.
νd (12B) is the Abbe number (nd (12B) −1) / (nF (12B) −nC (12B)) of the lens LB,
nd (12B), nC (12B), nF (12B), and ng (12B) are the refractive indexes of the d-line, C-line, F-line, and g-line of the lens LB, respectively.
It is.

The imaging optical system of the present embodiment is suitable for widening the angle at the same time as increasing the magnification (higher magnification). Here, when miniaturization is advanced, higher-order chromatic aberration, that is, color spherical aberration, color coma, higher-order component (color distortion aberration) relating to image height of chromatic aberration of magnification, and the like are likely to occur. When the sub lens group G12 is composed of the three lens elements as described above, high-order chromatic aberration can be corrected by joining the lens LA and the lens LB having a large dispersion difference via an aspherical surface. . The greater the difference between the dispersion of the lens LA and the dispersion of the lens LB, the greater the effect.
When the lower limit value of conditional expression (1) is not reached, the above-described correction effect for higher-order chromatic aberration is reduced.

It is more preferable that the following conditional expression (1 ′) is satisfied instead of conditional expression (1).
0.014 <{1 / νd (12A)} − {1 / νd (12B)} (1 ′)
Furthermore, it is more preferable that the following conditional expression (1 ″) is satisfied instead of conditional expression (1).
0.02 <{1 / νd (12A)} − {1 / νd (12B)} (1 ″)

Further, when higher-order chromatic aberration is corrected at the joint surface, each aberration with respect to the reference wavelength may be deteriorated. This is often caused by a large difference in refractive index between the lens LA and the lens LB with respect to the reference wavelength. Therefore, the imaging optical system of the present embodiment preferably satisfies the following conditional expression (2).
| Nd (12A) −nd (12B) | ≦ 0.30 (2)
here,
nd (12A) is the refractive index of the lens LA at the d-line,
nd (12B) is the refractive index of the lens LB at the d-line,
It is.

  If the upper limit of conditional expression (2) is exceeded, it will be difficult to achieve both high-order chromatic aberration correction and correction of aberrations at the reference wavelength such as the d-line.

It is more preferable that the following conditional expression (2 ′) is satisfied instead of conditional expression (2).
| Nd (12A) −nd (12B) | ≦ 0.20 (2 ′)
Furthermore, it is more preferable that the following conditional expression (2 ″) is satisfied instead of conditional expression (2).
| Nd (12A) −nd (12B) | ≦ 0.12 (2 ″)

In the imaging optical system of the present embodiment, in the orthogonal coordinate system in which the horizontal axis is νd and the vertical axis is nd,
nd (12A) = a (12A) × νd (12A) + b (12A) (however, a (12A) = − 0.0173)
When the straight line represented by the following formula (3) is set, the area defined by the straight line when the lower limit value and the straight line when the upper limit value are satisfied, and the following conditional expression (4) and It is preferable that nd (12A) and νd (12A) of the lens LA are included in both the region determined by (5).
1.64 <b (12A) <2.18 (3)
1.57 <nd (12A) <2.00 (4)
3 <νd (12A) <27 (5)
here,
nd (12A) is the refractive index of the lens LA at the d-line,
νd (12A) is the Abbe number (nd (12A) −1) / (nF (12A) −nC (12A)) of the lens LA,
nd (12A), nC (12A), nF (12A), and ng (12A) are the refractive indices of the d-line, C-line, F-line, and g-line of the lens LA, respectively.
It is.

  In order to effectively perform higher-order chromatic aberration correction, when the cemented surface is an aspherical surface, it is better that the difference in dispersion (reciprocal of Abbe number) between the lens LA and the lens LB is larger and the difference in refractive index is smaller. Here, if the medium constituting the lens LB is to be made as low dispersion as possible, the refractive index tends to be low. Therefore, it is desirable that the medium constituting the lens LA has a high refractive index and a refractive index as low as possible.

  If the upper limit value of conditional expression (3) or conditional expression (4) is exceeded, the refractive index difference between the two lenses becomes large, and higher-order chromatic aberration correction becomes difficult. On the other hand, if the lower limit value of conditional expressions (3) and (4) is not reached, the refractive index difference increases in the opposite direction, and similarly, higher-order chromatic aberration correction becomes difficult.

  If the upper limit value of conditional expression (5) is exceeded, this also makes it difficult to correct higher-order chromatic aberration. If the lower limit of conditional expression (5) is not reached, it will be difficult to lower the refractive index.

It is more preferable that the following conditional expression (3 ′) is satisfied instead of conditional expression (3).
1.70 <b (12A) <2.12 (3 ′)
Furthermore, it is more preferable that the following conditional expression (3 ″) is satisfied instead of conditional expression (11).
1.76 <b (12A) <2.06 (3 ″)

It is more preferable that the following conditional expression (4 ′) is satisfied instead of conditional expression (4).
1.59 <nd (12A) <1.90 (4 ')
Furthermore, it is more preferable that the following conditional expression (4 ″) is satisfied instead of conditional expression (4).
1.61 <nd (12A) <1.80 (4 ")

It is more preferable that the following conditional expression (5 ′) is satisfied instead of conditional expression (5).
8 <νd (12A) <26 (5 ′)
Furthermore, it is more preferable that the following conditional expression (5 ″) is satisfied instead of conditional expression (5).
13 <νd (12A) <25 (5 ″)

In the imaging optical system of the present embodiment, in the orthogonal coordinate system in which the horizontal axis is νd and the vertical axis is θgF,
θgF (12A) = α (12A) × νd (12A) + β (12A) (where α (12A) = − 0.00667)
When the straight line represented by is set, the region defined by the straight line when the range is the lower limit of the range of the following conditional expression (6) and the straight line when the upper limit is set, and the following conditional expression (5) It is preferable that θgF (12A) and νd (12A) of the lens LA are included in both the fixed region and the fixed region.
0.7840 <β (12A) <0.9000 (6)
3 <νd (12A) <27 (5)
here,
θgF (12A) is a partial dispersion ratio of the lens LA (ng (12A) −nF (12A)) / (nF (12A) −nC (12A)),
νd (12A) is the Abbe number of the lens LA, (nd (12A) −1) / (nF (12A) −nC (12A)),
nd (12A), nC (12A), nF (12A), and ng (12A) are the refractive indices of the d-line, C-line, F-line, and g-line of the lens LA, respectively.
It is.

  If the upper limit value of conditional expression (6) is exceeded, higher-order chromatic aberration due to the secondary spectrum tends to be overcorrected on the telephoto side. For this reason, it is difficult to ensure the sharpness of an image obtained by imaging on the telephoto side. On the other hand, when the lower limit value of conditional expression (6) is not reached, high-order chromatic aberration due to the secondary spectrum tends to be undercorrected on the telephoto side. For this reason, it is difficult to ensure the sharpness of an image obtained by imaging on the telephoto side.

  The high-order chromatic aberration due to the secondary spectrum here is spherical aberration, coma aberration, and distortion aberration in the g-line, and these aberrations are corrected so that the difference between the d-line and the F-line is small. In addition, this is the aberration remaining in the g-line.

  If the upper limit of conditional expression (5) is exceeded, the higher-order chromatic aberration correction effect tends to be insufficient. On the other hand, in the imaging optical system of this embodiment, the lens LA is used to correct each aberration of the reference wavelength such as d-line. Therefore, when the lower limit value of conditional expression (5) is not reached, higher-order chromatic aberration is likely to occur due to the aspheric surface on the air contact surface side of the lens LA. If this higher order chromatic aberration is to be suppressed, each aberration of the reference wavelength such as the d-line tends to be undercorrected.

It is more preferable that the following conditional expression (6 ′) is satisfied instead of conditional expression (6).
0.7920 <β (12A) <0.8800 (6 ′)
Furthermore, it is more preferable that the following conditional expression (6 ″) is satisfied instead of conditional expression (6).
0.8000 <β (12A) <0.8600 (6 ″)

Further, in the imaging optical system of the present embodiment, in the orthogonal coordinate system in which the horizontal axis is νd and the vertical axis is θhg, which is different from the orthogonal coordinates (orthogonal coordinates in which the horizontal axis is νd and the vertical axis is θgF). ,
θhg (12A) = αhg (12A) × νd (12A) + βhg (12A) (where αhg (12A) = − 0.01134)
When the straight line represented by is set, the region defined by the straight line when the range is the lower limit of the range of the following conditional expression (7) and the straight line when the upper limit is set, and the following conditional expression (5) It is desirable that θhg (12A) and νd (12A) of the lens LA are included in both the fixed region and the region.

0.8450 <βhg (12A) <0.9800 (7)
3 <νd (12A) <27 (5)
here,
θhg (12A) is the partial dispersion ratio (nh (12A) −ng (12A)) / (nF (12A) −nC (12A)) of the lens LA,
nh (12A) is the refractive index of the h-line of the lens LA,
It is.

  When the upper limit value of conditional expression (7) is exceeded, high-order chromatic aberration due to the secondary spectrum tends to be overcorrected on the telephoto side. Therefore, in an image obtained by imaging on the telephoto side, purple color flare and color blur are likely to occur over the entire screen. On the other hand, when the lower limit value of conditional expression (7) is not reached, high-order chromatic aberration due to the secondary spectrum tends to be undercorrected on the telephoto side. Therefore, in an image obtained by imaging on the telephoto side, purple color flare and color blur are likely to occur over the entire screen.

  The high-order chromatic aberration due to the secondary spectrum here is spherical aberration, coma aberration, and distortion aberration in the g-line, and these aberrations are corrected so that the difference between the d-line and the F-line is small. In addition, this is the aberration remaining in the h-line.

It is more preferable that the following conditional expression (7 ′) is satisfied instead of conditional expression (7).
0.8550 <βhg (12A) <0.9600 (7 ′)
Furthermore, it is more preferable that the following conditional expression (7 ″) is satisfied instead of conditional expression (7).
0.8650 <βhg (12A) <0.9400 (7 ″)

In the imaging optical system of this embodiment, it is preferable that the lens LA has a meniscus shape and satisfies the following condition (12).
| (R12AF−R12AR) / (R12AF + R12AR) | <0.2 (12)
here,
R12AF is the radius of curvature on the optical axis on the object side of the lens LA,
R12AR is the radius of curvature on the optical axis on the image side of the lens LA,
It is.

  The advantage of the lens LA having a meniscus shape is that the curvature of one surface can be increased without increasing the power of the lens LA, and the aberration correction capability can be easily obtained. This is particularly effective when an aspherical surface is used to correct higher-order chromatic aberration.

  However, if the conditional expression (12) is exceeded, it means that the meniscus shape becomes too strong. In this case, coma aberration of color, higher-order aberration (color distortion aberration) relating to the image height of magnification color, meridional image plane of color Any one of the curvatures becomes difficult to correct. On the other hand, if the value of conditional expression (12) is near zero, it may be difficult to perform high-order chromatic aberration correction as a whole.

Therefore, it is more preferable that the following conditional expression (12 ′) is satisfied instead of conditional expression (12).
0.005 <| (R12AF−R12AR) / (R12AF + R12AR) | <0.2 (12 ′)
Furthermore, it is more preferable that the following conditional expression (12 ″) is satisfied instead of conditional expressions (12) and (12 ′).
0.01 <| (R12AF-R12AR) / (R12AF + R12AR) | <0.1 (12 ")

  In the imaging optical system of the present embodiment, it is preferable that the air contact surfaces of the lenses LA and LB are also aspherical surfaces.

Further, when the optical total length is further shortened, the refractive power of each lens group becomes stronger. Here, it is necessary to increase the thickness of the sub-lens group G12 having a large diameter in order to secure the edge thickness. Therefore, in the imaging optical system of the present embodiment, it is preferable that the following conditional expression (13) is satisfied.
-0.2 <f12C / f12B <0.2 (13)
here,
f12B is the focal length of the lens LB,
f12C is the focal length of the positive lens LC,
It is.

  For the lens LB, it is required to increase the dispersion difference from the lens LA, to reduce the refractive index difference, and to form an aspheric surface on the cemented surface. Considering such a point, in reality, the refractive index of the lens LB cannot be increased so much. If the upper limit value of conditional expression (13) is exceeded or falls below the lower limit value, the refractive power of the lens LB increases relative to the refractive power of the positive lens LC, so that the sub lens group G12 tends to be thick.

It is more preferable that the following conditional expression (13 ′) is satisfied instead of conditional expression (13).
-0.1 <f12C / f12B <0.1 (13 ')
Furthermore, it is more preferable that the following conditional expression (13 ″) is satisfied instead of (13).
-0.05 <f12C / f12B <0.05 (13 ")

In the imaging optical system of the present embodiment, in the orthogonal coordinate system in which the horizontal axis is νd and the vertical axis is nd,
nd (12C) = a (12C) × νd (12C) + b (12C) (where a (12C) = − 0.00767)
When the straight line represented by is set, the region defined by the straight line when the range is the lower limit of the range of the following conditional expression (14) and the straight line when the upper limit is set, and the following conditional expression (15) It is preferable that nd (12C) and νd (12C) of the positive lens LC are included in the two regions including the fixed region.
2.10 <b (12C) (14)
1.70 <nd (12C) (15)
here,
νd (12C) is the Abbe number (nd (12C) −1) / (nF (12C) −nC (12C)) of the positive lens LC,
nd (12C), nC (12C), and nF (12C) are the refractive indexes of the d-line, C-line, and F-line of the positive lens LC, respectively.
It is.

  If the lower limit value of the conditional expression (14) is not reached, the curvature of the positive lens LC becomes too strong and the thickness becomes thick, high-order aberrations are likely to occur, and the total length of the optical system is shortened. One of the difficulties will occur. On the other hand, there is no problem with increasing b (12C). Note that nd (12C) may decrease as νd (12C) increases.

  If the lower limit value of conditional expression (15) is not reached, the problem described in conditional expression (14) is likely to occur even if the lower limit value of conditional expression (14) is not exceeded.

It is more preferable that the following conditional expression (14 ′) is satisfied instead of conditional expression (14).
2.15 <b (12C) (14 ')
Furthermore, it is more preferable that the following conditional expression (14 ″) is satisfied instead of conditional expression (14).
2.18 <b (12C) (14 ")

It is more preferable that the following conditional expression (15 ′) is satisfied instead of conditional expression (15).
1.75 <nd (12C) (15 ')
Furthermore, it is more preferable that the following conditional expression (15 ″) is satisfied instead of conditional expression (15).
1.80 <nd (12C) (15 ")

In the imaging optical system of the present embodiment, in the sub lens group G11, the lens component having negative refractive power or the prism having negative refractive power for bending the optical path is an element having negative refractive power. And it is preferable that the following conditional expression (16) is satisfied.
0.017 <{1 / νd (11)} − {1 / νd (12C)} <0.052 (16)
here,
νd (11) is the Abbe number (nd (11) −1) / (nF (11) −nC (11)) of the element having negative refractive power,
νd (12C) is the Abbe number (nd (12C) −1) / (nF (12C) −nC (12C)) of the positive lens LC,
nd (11), nC (11), and nF (11) are the refractive indexes of d-line, C-line, and F-line of the element having negative refractive power,
nd (12C), nC (12C), and nF (12C) are the refractive indexes of the d-line, C-line, and F-line of the positive lens LC, respectively.
It is.

  Conditional expression (16) indicates a condition for correcting primary chromatic aberration generated in the sub lens group G12 by the sub lens group G11. When the conditional expression (16) is satisfied, the primary chromatic aberration (axial chromatic aberration, lateral chromatic aberration) as a whole of the lens group G1 can be corrected. , Lateral chromatic aberration) is difficult to correct well over the entire zoom range. If the upper limit value of conditional expression (16) is exceeded, particularly the lateral chromatic aberration will be overcorrected, and it will be difficult to satisfactorily correct over the entire zoom range.

It is more preferable that the following conditional expression (16 ′) is satisfied instead of conditional expression (16).
0.020 <{1 / νd (11)} − {1 / νd (12C)} <0.045 (16 ′)
Furthermore, it is more preferable that the following conditional expression (16 ″) is satisfied instead of conditional expression (16).
0.023 <{1 / νd (11)} − {1 / νd (12C)} <0.038 (16 ″)

  The medium constituting the lens LA is highly dispersed. For this reason, in order to correct primary chromatic aberration such as axial chromatic aberration and paraxial lateral chromatic aberration, it is generally preferable that the negative refractive power is large.

Moreover, it is preferable that the imaging optical system of this embodiment satisfies the following conditional expression (17).
-0.2 <fw / f12A <0.2 (17)
here,
fw is the focal length of the entire system at the wide angle end of the imaging optical system,
f12A is the focal length of the lens LA in the air,
It is.

  In the imaging optical system of the present embodiment, the negative refracting power is largely borne by the sub-lens group G11, and the positive refracting power is not weakened for the lens LA (the negative refracting power is not borne so much). Is preferred.

  If the lower limit of conditional expression (17) is not reached, the negative refractive power increases. As a result, the axial chromatic aberration and the paraxial lateral chromatic aberration are likely to be overcorrected, or the refractive power of the sub lens group G11 is weakened. For this reason, the entrance pupil position becomes deep and it becomes difficult to reduce the size of the prism. If the upper limit of conditional expression (17) is exceeded, the positive refractive power will increase. As a result, axial chromatic aberration and paraxial lateral chromatic aberration cannot be corrected by the sub lens group G11.

It is more preferable that the following conditional expression (17 ′) is satisfied instead of conditional expression (17).
-0.1 <fw / f12A <0.1 (17 ')
Furthermore, it is more preferable that the following conditional expression (17 ″) is satisfied instead of conditional expression (17).
-0.05 <fw / f12A <0.05 (17 ")

  In the imaging optical system of the present embodiment, it is more preferable that one of the surfaces of the cemented lens component of the lens LA and the lens LB is cemented with the positive lens LC. In the following embodiments, among these three lens elements, the lens LC is disposed closest to the image side, but the positive lens LC may be disposed closest to the object side.

Moreover, it is preferable that the imaging optical system of this embodiment satisfies at least one of the following conditional expressions (18a) and (18b).
-7.0 <f11 / Dp <-1.5 (18a)
1.2 <f12 / Dp <5.0 (18b)
here,
f11 is the focal length of the sub lens group G11,
f12 is the focal length of the sub lens group G12,
Dp is the air equivalent distance along the optical axis from the entrance surface to the exit surface of the prism,
It is.

  In order to widen the imaging optical system, particularly the zoom optical system without enlarging, it is preferable to make the entrance pupil position as shallow as possible. Further, in order to bend the optical path, a prism optical path length of a certain length or more is necessary. If the focal length f11 or the focal length f12 is not sufficiently small with respect to the prism optical path length, the entire first lens group tends to be enlarged.

  If the upper limit value of conditional expressions (18a) and (18b ') is exceeded, the entire first lens group tends to be enlarged. On the other hand, if the lower limit value of conditional expressions (18a) and (18b ′) is not reached, high-order chromatic aberration is likely to occur particularly at the telephoto end.

It is more preferable that the following conditional expression (18a ′) is satisfied instead of conditional expression (18a).
−6.0 <f11 / Dp <−2.0 (18a ′)
Furthermore, it is more preferable that the following conditional expression (18a ″) is satisfied instead of conditional expression (18a).
-5.0 <f11 / Dp <-2.5 (18a ")

It is more preferable that the following conditional expression (18b ′) is satisfied instead of conditional expression (18b).
1.5 <f12 / Dp <4.0 (18b ')
Furthermore, it is more preferable that the following conditional expression (18b ″) is satisfied instead of conditional expression (18a).
1.8 <f12 / Dp <3.0 (18b ")

Moreover, it is preferable that the imaging optical system of the present embodiment satisfies the following conditional expression (19).
-2.0 <(R11F + R11R) / (R11F-R11R) <2.0 (19)
here,
R11F is the radius of curvature on the optical axis of the most object side surface of the sub lens group G11,
R11R is a radius of curvature on the optical axis of the surface closest to the image side of the sub lens group G11,
It is.

  When the conditional expression (19) is satisfied, astigmatism and coma can be corrected better over the entire zoom range. If the upper limit of conditional expression (19) is exceeded, correction of astigmatism and coma will tend to be insufficient. On the other hand, if the lower limit of conditional expression (19) is not reached, barrel distortion tends to increase.

It is more preferable that the following conditional expression (19 ′) is satisfied instead of conditional expression (19).
-1.5 <(R11F + R11R) / (R11F-R11R) <1.0 (19 ')
Furthermore, it is more preferable that the following conditional expression (19 ″) is satisfied instead of conditional expression (19).
-1.2 <(R11F + R11R) / (R11F-R11R) <0.5 (19 ")

Moreover, it is preferable that the imaging optical system of this embodiment satisfies the following conditional expression (20).
-1.0 <f2 / f1 <-0.20 (20)
here,
f1 is the focal length of the positive lens group G1,
f2 is the focal length of the negative lens group G2,
It is.

  When the conditional expression (20) is satisfied, astigmatism and coma can be corrected better over the entire zoom range.

It is more preferable that the following conditional expression (20 ′) is satisfied instead of conditional expression (20).
-0.8 <f2 / f1 <-0.25 (20 ')
Furthermore, it is more preferable that the following conditional expression (20 ″) is satisfied instead of conditional expression (20).
-0.6 <f2 / f1 <-0.35 (20 ")

  In the imaging optical system of the present embodiment, the lens group G2 is preferably arranged in order from the object side, a negative lens component, a negative lens component, and a positive lens component. In particular, the first negative lens component is preferably a single lens having a refractive index of 1.85 or more. Furthermore, it is better if the refractive index of the first negative lens component is 1.90 or more.

  In the lens group G2, it is preferable that any air contact surface of the second negative lens component is aspheric. In the second negative lens component, it is further preferable that the cemented surface is an aspheric surface. The positive lens component is preferably a single lens having an Abbe number of 24 or less. Furthermore, it is even better if the Abbe number of the positive lens component is 21 or less.

  The rear lens group GR may be composed of a lens group G3 having a positive refractive power, a lens group G4 having a positive refractive power, and a final lens group G6 having a positive refractive power in order from the object side. preferable. Here, the lens group G3 is preferably fixed at the time of zooming in the vicinity of the aperture stop. The lens group G4 is preferably movable on the optical axis at the time of zooming. The final lens group G6 is preferably movable on the optical axis during zooming.

  The lens group G5 may be arranged between the lens group G4 and the lens group G6. In this case, it is preferable that the relative distance between the lens group G5 and the lens group G4 or the lens group G6 changes during zooming. When the lens group G5 is arranged, it is preferable that the final lens group G6 is fixed at the time of zooming.

  The lens group G3 is preferably composed of a single lens. The lens group G4 is preferably composed of two positive lenses and one or two negative lenses. The lens group G5 is preferably composed of one negative lens. The final lens group G6 may have a configuration in which one positive lens or one negative lens is added thereto. Focusing may be performed using the entire lens group G4 or a part thereof (lens component closest to the image side) or the lens group G5.

  Here, a manufacturing method of the sub lens group G12 will be described. First, a liquid resin to be the lens LA is brought into contact with one optical surface of the lens LB or the positive lens LC. When the sub-lens group G12 is a three-lens cemented lens consisting of the lens LB, the lens LA, and the positive lens LC, then a liquid resin is sandwiched between the optical surfaces of the other lens. Then, for example, by applying energy such as ultraviolet rays, the liquid resin that becomes the lens LA is cured. The sub lens group G12 can be manufactured by such a process.

  By this manufacturing method, it is possible to improve manufacturing accuracy such as surface shape, thickness, and eccentricity. This method is extremely effective for thinning the lens element and making the cemented surface aspherical. The lens LB or the positive lens LC may be subjected to a surface treatment such as coating in advance.

  Further, glass may be adhered and cured as the lens LA on the surface of the lens LB or the positive lens LC. If any of the lens LA, the lens LB, and the positive lens LC is glass, the quality is easily stabilized with little thermal distortion due to the difference in expansion coefficient. In this case, the characteristics of the material for the lens LA need to have a lower melting point and transition point than the materials constituting the lens LB and the positive lens LC.

The electronic imaging apparatus of the present embodiment includes the above-described imaging optical system and an electronic imaging device, and the coordinate axis is z with the optical axis direction z and the direction perpendicular to the optical axis h, and R is a spherical component. The radius of curvature on the optical axis, K is a conic constant, A ₄ , A ₆ , A ₈ , A ₁₀ ... Are aspheric coefficients, and the shape of the aspheric surface is expressed by the following equation (8):
z = (h ² / R) / {1+ [1- (1 + K) (h / R) ² ] ^1/2 }
+ A ₄ h ⁴ + A ₆ h ⁶ + A ₈ h ⁸ + A ₁₀ h ¹⁰ (8)
When the deviation amount is expressed by the following formula (9),
Δz = z−h ² / R {1+ (1−h ² / R ² ) ^1/2 } (9)
It is preferable that the following conditional expression (10) is satisfied.

When R _12A ≧ 0
-5.0e-2 <P (LA) / y 10 <0 < However, h = 2.5a> ··· (10 )
here,
P (LA) is a parameter related to the shape and dispersion of the joint surface, and is represented by the following equation:
P (LA) = Δz _12A (h) ・ (1 / νd (12A) −1 / νd (12B))
z _12A is the shape of the joint surface, the shape according to equation (8),
Δz _12A (h) is the amount of deviation of the joint surface, and the amount of deviation according to equation (9),
R _12A is the paraxial radius of curvature of the joint surface,
a is an amount according to the following conditional expression (11),
a = (y ₁₀ ) ² · log ₁₀ γ / fw (11)
Both air contact surfaces may be spherical,
y ₁₀ is the distance (maximum image height) from the center to the farthest point in the effective imaging plane (within the imaging plane) of the electronic imaging device arranged in the vicinity of the imaging position of the imaging optical system;
fw is the focal length of the entire system at the wide angle end of the imaging optical system,
γ is the imaging ratio (total focal length at the telephoto end / total focal length at the wide angle end),
Also, since the top of each surface is the origin, z (0) = 0 is always set.
It is.

  If the upper limit of conditional expression (10) is exceeded, especially on the telephoto side, higher-order components relating to the image height of higher-order chromatic aberrations, that is, color spherical aberration, color coma, and lateral chromatic aberration, while correcting spherical aberration and coma aberration ( It becomes difficult to correct color distortion. On the other hand, if the lower limit of the condition (10) is not reached, correction of these higher-order chromatic aberrations becomes excessive, or aberrations with respect to a reference wavelength such as d-line are likely to deteriorate.

It is more preferable that the following conditional expression (10 ′) is satisfied instead of conditional expression (10).
-2.0e-2 <P (LA) / y ₁₀ <0 (where h = 2.5a) (10 ')
Furthermore, it is more preferable that the following conditional expression (10 ″) is satisfied instead of conditional expression (10).
-1.0e-2 <P (LA) / y ₁₀ <0 (where h = 2.5a) (10 ")

  Further, when coma and astigmatism are corrected over a wide field angle, strong barrel distortion occurs on the wide angle side. On the other hand, when barrel distortion is corrected, coma and astigmatism worsen in a portion with a large angle of view. Therefore, a method for realizing a wider angle of view by actively utilizing the occurrence of barrel distortion will be described below. If this is used, it will become easy to satisfy each conditional expression (1)-(20) described so far.

First, suppose that an object at infinity is imaged by an optical system without distortion. In this case, since the image formed has no distortion,
f = y / tan ω (21)
Is established.
here,
y is the height of the image point from the optical axis,
f is the focal length of the imaging system,
ω is an angle with respect to the optical axis in the object direction corresponding to the image point connected from the center on the imaging surface to the position y.

On the other hand, if the optical system has barrel distortion,
f> y / tan ω (22)
It becomes.
That is, if f and y are constant values, ω is a large value.
Therefore, it is preferable to use an optical system that intentionally has a large barrel distortion, particularly at a focal length near the wide-angle end, for the electronic imaging device. In this case, it is possible to achieve a wider angle of view of the optical system as much as it is not necessary to correct distortion.

  However, the image of the object is formed on the electronic image pickup device in a state having barrel-shaped distortion. Therefore, in the electronic imaging device, image data obtained by the electronic imaging element is processed by image processing. In this processing, the image data (image shape) is changed so as to correct the barrel distortion. In this way, the finally obtained image data is image data having a shape substantially similar to the object. Therefore, an object image may be output to a CRT or printer based on the image data.

  Therefore, the electronic imaging apparatus of the present embodiment processes the image data obtained by capturing an image formed through the imaging optical system, the electronic imaging element, and the imaging optical system with the electronic imaging element. And image processing means for outputting as image data with the image shape changed, and the imaging optical system satisfies the following conditional expression (23) when focusing on an object point at infinity.

0.85 <y ₀₇ / (fw · tan ω _07w ) <0.97 (23)
here,
y ₀₇ is expressed as y07 = 0.7 · y10 when the y10 distance (maximum image height) to a point farthest from the center in the effective image pickup plane of the electronic imaging device (imaging possible in-plane),
ω _07w is an angle with respect to the optical axis in the object direction corresponding to the image point connecting from the center on the imaging surface at the wide angle end to the position of y ₀₇ ,
fw is the focal length of the entire system at the wide-angle end of the imaging optical system,
It is.

  Conditional expression (23) defines the degree of barrel distortion at the zoom wide-angle end. If the conditional expression (23) is satisfied, it becomes possible to capture information with a wide angle of view without enlarging the optical system. Note that an image distorted in a barrel shape is photoelectrically converted by an image sensor to become image data distorted in a barrel shape.

  The image data distorted into a barrel shape is electrically processed by an image processing means, which is a signal processing system of an electronic imaging device, corresponding to a change in the shape of the image. In this way, when the image data finally output from the image processing means is reproduced on the display device, the distortion is corrected and an image substantially similar to the subject shape is obtained.

  Here, when the upper limit value of conditional expression (23) is exceeded, and particularly when the upper limit value is close to 1, an image in which distortion is optically corrected is obtained. Therefore, the correction performed by the image processing means can be small. In this case, it is difficult to widen the angle of view of the optical system while maintaining the miniaturization of the optical system.

  On the other hand, below the lower limit value of the conditional expression (23), when image distortion due to distortion of the optical system is corrected by the image processing means, the stretching ratio in the radial direction around the angle of view becomes too high. As a result, in the image obtained by imaging, the sharpness degradation at the periphery of the image becomes conspicuous.

  Thus, by satisfying conditional expression (23), it is possible to reduce the size and widen the angle of the optical system (make the vertical angle of view of distortion more than 38 °).

It is more preferable that the following conditional expression (23 ′) is satisfied instead of conditional expression (23).
0.88 <y ₀₇ / (fw · tan ω _07w ) <0.96 (23 ′)
Furthermore, it is more preferable that the following conditional expression (23 ″) is satisfied instead of conditional expression (23).
0.90 <y ₀₇ / (fw · tan ω _07w ) <0.95 (23 ″)

  As described above, in the present embodiment, a zoom lens having high optical specifications such as a high zoom ratio and a wide angle of view is mounted, but the depth direction is extremely thin, and there is little distortion and high-quality shooting is possible. An electronic imaging device can be provided.

  Next, a zoom lens according to embodiment 1 of the present invention will be described. FIGS. 1A and 1B are cross-sectional views along the optical axis showing the optical configuration of the zoom lens according to the first embodiment of the present invention when focusing on an object point at infinity. FIG. 1A is a wide-angle end, and FIG. (C) is a sectional view at the telephoto end.

  FIG. 2 is a diagram illustrating spherical aberration (SA), astigmatism (AS), distortion (DT), and lateral chromatic aberration (CC) when the zoom lens according to Example 1 is focused on an object point at infinity. a) shows the wide-angle end, (b) shows the intermediate focal length state, and (c) shows the state at the telephoto end. FIY represents the image height. The symbols in the aberration diagrams are the same in the examples described later.

  As shown in FIG. 1, the zoom lens of Example 1 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, and a positive refractive power. A third lens group G3 having an aperture stop S, a fourth lens group G4 having a positive refractive power, a fifth lens group G5 having a negative refractive power, and a sixth lens group having a positive refractive power. G6. In all the following examples, in the lens cross-sectional views, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

  The first lens group G1 includes, in order from the object side, a negative meniscus lens L1 having a convex surface directed toward the image surface side, a prism L2, a meniscus lens L3 having a paraxial radius of curvature and a convex surface facing the object side, and an object surface. It is composed of a cemented lens of a positive meniscus lens L4 having a convex surface on the side and a biconvex positive lens L5, and has a positive refractive power as a whole.

  The meniscus lens L3 corresponds to the lens LB, the positive meniscus lens L4 corresponds to the lens LA, and the biconvex positive lens L5 corresponds to the lens LC.

  The second lens group G2 includes, in order from the object side, a negative meniscus lens L6 having a convex surface directed toward the object side, a biconcave negative lens L7, and a biconvex positive lens L8. Have power.

  The third lens group G3 includes a positive meniscus lens L9 having a convex surface directed toward the object side, and has a positive refracting power as a whole.

  The fourth lens group G4 includes, in order from the object side, a cemented lens of a biconvex positive lens L10, a negative meniscus lens L11 having a convex surface facing the image surface, and a positive meniscus lens L12 having a convex surface facing the image surface. And has a positive refractive power as a whole.

  The fifth lens group G5 includes a negative meniscus lens L13 having a convex surface directed toward the object side, and has a negative refracting power as a whole.

  The sixth lens group G6 includes, in order from the object side, a biconvex positive lens L14 and a negative meniscus lens L15 having a convex surface directed toward the image surface side. The sixth lens group G6 has a positive refractive power as a whole.

  When zooming from the wide-angle end to the telephoto end, the first lens group G1 is fixed. The second lens group G2 moves to the image plane side. The third lens group G3 is fixed. The fourth lens group G4 moves to the object side. The fifth lens group moves to the object side. The sixth lens group is fixed.

  The aspheric surfaces are both the object-side both surfaces of the negative meniscus lens L1 of the first lens group G1, both surfaces of the meniscus lens L3, both surfaces of the biconcave negative lens L7 of the second lens group G2, and both of the fourth lens group G4. It is provided on nine surfaces including the object-side surface of the convex positive lens L10, the image-side surface of the positive meniscus lens L12, and the negative-side meniscus lens L15 of the sixth lens group G6.

  Next, a zoom lens according to embodiment 2 of the present invention will be described. FIGS. 3A and 3B are cross-sectional views along the optical axis showing the optical configuration of the zoom lens according to the second embodiment of the present invention when focusing on an object point at infinity, where FIG. 3A is a wide-angle end, and FIG. (C) is a sectional view at the telephoto end.

  FIG. 4 is a diagram illustrating spherical aberration (SA), astigmatism (AS), distortion (DT), and lateral chromatic aberration (CC) when the zoom lens according to Example 2 is focused on an object point at infinity. a) shows the wide-angle end, (b) shows the intermediate focal length state, and (c) shows the state at the telephoto end.

  As shown in FIG. 3, the zoom lens of Example 2 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, and a positive refractive power. A third lens group G3 having an aperture stop S, a fourth lens group G4 having a positive refractive power, a fifth lens group G5 having a negative refractive power, and a sixth lens group having a positive refractive power. G6.

  The first lens group G1 includes, in order from the object side, a negative meniscus lens L1 having a convex surface directed toward the image surface side, a prism L2, a meniscus lens L3 having a paraxial radius of curvature and a convex surface facing the object side, and an object surface. It is composed of a cemented lens of a positive meniscus lens L4 having a convex surface on the side and a biconvex positive lens L5, and has a positive refractive power as a whole.

  The meniscus lens L3 corresponds to the lens LB, the positive meniscus lens L4 corresponds to the lens LA, and the biconvex positive lens L5 corresponds to the lens LC.

  The second lens group G2 includes, in order from the object side, a negative meniscus lens L6 having a convex surface directed toward the object side, a biconcave negative lens L7, and a biconvex positive lens L8. Have power.

  The third lens group G3 includes a positive meniscus lens L9 having a convex surface directed toward the object side, and has a positive refracting power as a whole.

  The fourth lens group G4 includes a cemented lens which includes a biconvex positive lens L10, a negative meniscus lens L11 having a convex surface directed toward the image surface, and a positive meniscus lens L12 having a convex surface directed toward the image surface. Has positive refractive power.

  The fifth lens group G5 includes a negative meniscus lens L13 having a convex surface directed toward the object side, and has a negative refracting power as a whole.

  The sixth lens group G6 includes a biconvex positive lens L14 and a negative meniscus lens L15 having a convex surface directed toward the image surface side, and has a positive refractive power as a whole.

  When zooming from the wide-angle end to the telephoto end, the first lens group G1 is fixed. The second lens group G2 moves to the image plane side. The third lens group G3 is fixed. The fourth lens group G4 moves to the object side. The fifth lens group moves to the object side. The sixth lens group is fixed.

  The aspheric surfaces are both the object-side both surfaces of the negative meniscus lens L1 of the first lens group G1, both surfaces of the meniscus lens L3, both surfaces of the biconcave negative lens L7 of the second lens group G2, and both of the fourth lens group G4. It is provided on nine surfaces including the object-side surface of the convex positive lens L10, the image-side surface of the positive meniscus lens L12, and the negative-side meniscus lens L15 of the sixth lens group G6.

  Next, a zoom lens according to embodiment 3 of the present invention will be described. FIGS. 5A and 5B are cross-sectional views along the optical axis showing an optical configuration when focusing on an object point at infinity of a zoom lens according to Example 3 of the present invention, where FIG. 5A is a wide-angle end, and FIG. (C) is a sectional view at the telephoto end.

  FIG. 6 is a diagram illustrating spherical aberration (SA), astigmatism (AS), distortion (DT), and lateral chromatic aberration (CC) when the zoom lens according to Example 3 is focused on an object point at infinity. a) shows the wide-angle end, (b) shows the intermediate focal length state, and (c) shows the state at the telephoto end.

  As shown in FIG. 5, 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, and a positive refractive power. A third lens group G3 having an aperture stop S, a fourth lens group G4 having a positive refractive power, and a fifth lens group G5 having a positive refractive power.

  The first lens group G1 includes, in order from the object side, a negative meniscus lens L1 having a convex surface directed toward the image surface side, a prism L2, a meniscus lens L3 having a paraxial radius of curvature and a convex surface facing the object side, and an object surface. It is composed of a cemented lens of a negative meniscus lens L4 having a convex surface on the side and a biconvex positive lens L5, and has a positive refractive power as a whole.

  The meniscus lens L3 corresponds to the lens LB, the negative meniscus lens L4 corresponds to the lens LA, and the biconvex positive lens L5 corresponds to the lens LC.

  The second lens group G2 includes, in order from the object side, a negative meniscus lens L6 having a convex surface directed toward the object side, a biconcave negative lens L7, and a biconvex positive lens L8. Have power.

  The third lens group G3 includes a positive meniscus lens L9 having a convex surface directed toward the object side, and has a positive refracting power as a whole.

  The fourth lens group G4 includes a cemented lens of a positive meniscus lens L10 having a convex surface directed toward the object side, a negative meniscus lens L11 having a convex surface directed toward the object side, and a biconvex positive lens L12, and a negative lens having a convex surface directed toward the object side. It is composed of a meniscus lens L13 and has a positive refractive power as a whole.

  The fifth lens group G5 includes a positive meniscus lens L14 having a convex surface directed toward the image surface side, and has a positive refracting power as a whole.

  When zooming from the wide-angle end to the telephoto end, the first lens group G1 is fixed. The second lens group G2 moves to the image plane side. The third lens group G3 is fixed. The fourth lens group G4 moves to the object side. The fifth lens group moves to the image plane side.

  The aspheric surfaces include both surfaces of the meniscus lens L3 of the first lens group G1, both surfaces of the biconcave negative lens L7 of the second lens group G2, the object side surface of the positive meniscus lens L10 of the fourth lens group G4, and both. The convex positive lens L12 is provided on six surfaces with the image side surface.

  Next, a zoom lens according to embodiment 4 of the present invention will be described. FIGS. 7A and 7B are cross-sectional views along the optical axis showing the optical configuration when focusing on an object point at infinity of a zoom lens according to Example 4 of the present invention, where FIG. 7A is a wide angle end, and FIG. (C) is a sectional view at the telephoto end.

  FIG. 8 is a diagram illustrating spherical aberration (SA), astigmatism (AS), distortion (DT), and lateral chromatic aberration (CC) when the zoom lens according to Example 4 is focused on an object point at infinity. a) shows the wide-angle end, (b) shows the intermediate focal length state, and (c) shows the state at the telephoto end.

  As shown in FIG. 7, 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, and a positive refractive power. A third lens group G3 having an aperture stop S, a fourth lens group G4 having a positive refractive power, and a fifth lens group G5 having a positive refractive power.

  The first lens group G1 includes, in order from the object side, a biconcave negative lens L1, a prism L2, a meniscus lens L3 having a paraxial radius of curvature with the same convex surface facing the object side, and a positive surface facing the convex side toward the object side. It is composed of a cemented lens of a meniscus lens L4 and a biconvex positive lens L5, and has a positive refractive power as a whole.

  The meniscus lens L3 corresponds to the lens LB, the positive meniscus lens L4 corresponds to the lens LA, and the biconvex positive lens L5 corresponds to the lens LC.

  The second lens group G2 includes, in order from the object side, a negative meniscus lens L6 having a convex surface directed toward the object side, a cemented lens of a positive meniscus lens L7 having a convex surface directed toward the image side and a biconcave negative lens L8, It consists of a convex positive lens L9 and has a negative refractive power as a whole.

  The third lens group G3 includes a positive meniscus lens L10 having a convex surface directed toward the object side, and has a positive refracting power as a whole.

  The fourth lens group G4 includes a cemented lens of a positive meniscus lens L11 having a convex surface directed toward the object side, a negative meniscus lens L12 having a convex surface directed toward the object side, and a biconvex positive lens L13, and a negative lens having a convex surface directed toward the object side. It is composed of a meniscus lens L14 and has a positive refractive power as a whole.

  The fifth lens group G5 includes a positive meniscus lens L15 having a convex surface directed toward the image side, and has a positive refracting power as a whole.

  When zooming from the wide-angle end to the telephoto end, the first lens group G1 is fixed. The second lens group G2 moves to the image plane side. The third lens group G3 is fixed. The fourth lens group G4 moves to the object side. The fifth lens group moves to the image plane side.

  The aspheric surfaces include both surfaces of the meniscus lens L3 of the first lens group G1, both surfaces of the positive meniscus lens L7 of the second lens group G2, the image side surface of the biconcave negative lens L8, and the fourth lens group G4. It is provided on seven surfaces, that is, the object-side surface of the positive meniscus lens L11 and the image-side surface of the biconvex positive lens L13.

  Next, a zoom lens according to embodiment 5 of the present invention will be described. 9A and 9B are cross-sectional views along the optical axis showing the optical configuration of the zoom lens according to Example 5 of the present invention when focusing on an object point at infinity, where FIG. 9A is a wide-angle end, and FIG. (C) is a sectional view at the telephoto end.

  FIG. 10 is a diagram illustrating spherical aberration (SA), astigmatism (AS), distortion (DT), and lateral chromatic aberration (CC) when the zoom lens according to Example 5 is focused on an object point at infinity. a) shows the wide-angle end, (b) shows the intermediate focal length state, and (c) shows the state at the telephoto end.

  As shown in FIG. 9, 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, and a positive refractive power. A third lens group G3 having an aperture stop S, a fourth lens group G4 having a positive refractive power, and a fifth lens group G5 having a positive refractive power.

  The first lens group G1 includes, in order from the object side, a biconcave negative lens L1, a prism L2, a meniscus lens L3 having a paraxial radius of curvature with the same convex surface facing the object side, and a negative surface facing the convex side toward the object side. It is composed of a cemented lens of a meniscus lens L4 and a biconvex positive lens L5, and has a positive refractive power as a whole.

  The meniscus lens L3 corresponds to the lens LB, the negative meniscus lens L4 corresponds to the lens LA, and the biconvex positive lens L5 corresponds to the lens LC.

  The second lens group G2 includes, in order from the object side, a negative meniscus lens L6 having a convex surface directed toward the object side, a cemented lens of a positive meniscus lens L7 having a convex surface directed toward the image side and a biconcave negative lens L8, It consists of a convex positive lens L9 and has a negative refractive power as a whole.

  The third lens group G3 includes a positive meniscus lens L10 having a convex surface directed toward the object side, and has a positive refracting power as a whole.

  The fourth lens group G4 includes a cemented lens of a positive meniscus lens L11 having a convex surface directed toward the object side, a negative meniscus lens L12 having a convex surface directed toward the object side, and a biconvex positive lens L13, and a negative lens having a convex surface directed toward the object side. It is composed of a meniscus lens L14 and has a positive refractive power as a whole.

  The fifth lens group G5 includes a positive meniscus lens L15 having a convex surface directed toward the image side, and has a positive refracting power as a whole.

  When zooming from the wide-angle end to the telephoto end, the first lens group G1 is fixed. The second lens group G2 moves to the image plane side. The third lens group G3 is fixed. The fourth lens group G4 moves to the object side. The fifth lens group moves to the image plane side.

  The aspheric surfaces include both surfaces of the meniscus lens L3 of the first lens group G1, both surfaces of the positive meniscus lens L7 of the second lens group G2, the image side surface of the biconcave negative lens L8, and the fourth lens group G4. It is provided on seven surfaces, that is, the object-side surface of the positive meniscus lens L11 and the image-side surface of the biconvex positive lens L13.

  Next, a zoom lens according to embodiment 6 of the present invention will be described. 11A and 11B are cross-sectional views along the optical axis showing the optical configuration of the zoom lens according to Example 6 of the present invention when focusing on an object point at infinity. FIG. 11A is a wide-angle end, and FIG. (C) is a sectional view at the telephoto end.

  FIG. 12 is a diagram illustrating spherical aberration (SA), astigmatism (AS), distortion (DT), and lateral chromatic aberration (CC) when the zoom lens according to Example 6 is focused on an object point at infinity. a) shows the wide-angle end, (b) shows the intermediate focal length state, and (c) shows the state at the telephoto end.

  As shown in FIG. 11, 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, and a positive refractive power. A third lens group G3 having an aperture stop S, a fourth lens group G4 having a positive refractive power, and a fifth lens group G5 having a positive refractive power.

  The first lens group G1 includes, in order from the object side, a biconcave negative lens L1, a prism L2, a meniscus lens L3 having a paraxial radius of curvature with the same convex surface facing the object side, and a negative surface facing the convex side toward the object side. It is composed of a cemented lens of a meniscus lens L4 and a biconvex positive lens L5, and has a positive refractive power as a whole.

  The meniscus lens L3 corresponds to the lens LB, the negative meniscus lens L4 corresponds to the lens LA, and the biconvex positive lens L5 corresponds to the lens LC.

  The second lens group G2 includes, in order from the object side, a negative meniscus lens L6 having a convex surface directed toward the object side, a cemented lens of a positive meniscus lens L7 having a convex surface directed toward the image side and a biconcave negative lens L8, It consists of a convex positive lens L9 and has a negative refractive power as a whole.

  The third lens group G3 includes a positive meniscus lens L10 having a convex surface directed toward the object side, and has a positive refracting power as a whole.

  The fourth lens group G4 includes a cemented lens of a positive meniscus lens L11 having a convex surface directed toward the object side, a negative meniscus lens L12 having a convex surface directed toward the object side, and a biconvex positive lens L13, and a negative lens having a convex surface directed toward the object side. It is composed of a meniscus lens L14 and has a positive refractive power as a whole.

  The fifth lens group G5 includes a positive meniscus lens L15 having a convex surface directed toward the image side, and has a positive refracting power as a whole.

  When zooming from the wide-angle end to the telephoto end, the first lens group G1 is fixed. The second lens group G2 moves to the image plane side. The third lens group G3 is fixed. The fourth lens group G4 moves to the object side. The fifth lens group moves to the image plane side.

  The aspheric surfaces include both surfaces of the meniscus lens L3 of the first lens group G1, both surfaces of the positive meniscus lens L7 of the second lens group G2, the image side surface of the biconcave negative lens L8, and the fourth lens group G4. It is provided on seven surfaces, that is, the object-side surface of the positive meniscus lens L11 and the image-side surface of the biconvex positive lens L13.

  Next, a zoom lens according to embodiment 7 of the present invention will be described. FIGS. 13A and 13B are cross-sectional views along the optical axis showing the optical configuration when focusing on an object point at infinity of a zoom lens according to Example 7 of the present invention. FIG. 13A is a wide-angle end, and FIG. 13B is an intermediate focal length state. (C) is a sectional view at the telephoto end.

  FIG. 14 is a diagram showing spherical aberration (SA), astigmatism (AS), distortion (DT), and lateral chromatic aberration (CC) when the zoom lens according to Example 7 is focused on an object point at infinity. a) shows the wide-angle end, (b) shows the intermediate focal length state, and (c) shows the state at the telephoto end.

  As shown in FIG. 13, the zoom lens according to the seventh 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, and a positive refractive power. A third lens group G3 having an aperture stop S, a fourth lens group G4 having a positive refractive power, and a fifth lens group G5 having a positive refractive power.

  The first lens group G1 has, in order from the object side, a biconcave negative lens L1, a prism L2, a negative meniscus lens L3 with a convex surface facing the object side, and a paraxial radius of curvature that is equal on both surfaces with the convex surface facing the object side. It is composed of a cemented lens of a meniscus lens L4 and a biconvex positive lens L5, and has a positive refractive power as a whole.

  The negative meniscus lens L3 corresponds to the lens LA, the meniscus lens L4 corresponds to the lens LB, and the biconvex positive lens L5 corresponds to the lens LC.

  The second lens group G2 includes, in order from the object side, a negative meniscus lens L6 having a convex surface directed toward the object side, a cemented lens of a positive meniscus lens L7 having a convex surface directed toward the image side and a biconcave negative lens L8, It consists of a convex positive lens L9 and has a negative refractive power as a whole.

  The third lens group G3 includes a positive meniscus lens L10 having a convex surface directed toward the object side, and has a positive refracting power as a whole.

  The fourth lens group G4 includes a cemented lens of a positive meniscus lens L11 having a convex surface directed toward the object side, a negative meniscus lens L12 having a convex surface directed toward the object side, and a biconvex positive lens L13, and a negative lens having a convex surface directed toward the object side. It is composed of a meniscus lens L14 and has a positive refractive power as a whole.

  The fifth lens group G5 includes a positive meniscus lens L15 having a convex surface directed toward the image side, and has a positive refracting power as a whole.

  When zooming from the wide-angle end to the telephoto end, the first lens group G1 is fixed. The second lens group G2 moves to the image plane side. The third lens group G3 is fixed. The fourth lens group G4 moves to the object side. The fifth lens group moves to the image plane side.

  The aspheric surfaces include both surfaces of the negative meniscus lens L3 of the first lens group G1, both surfaces of the positive meniscus lens L7 of the second lens group G2, the image side surface of the biconcave negative lens L8, and the fourth lens group G4. Of the positive meniscus lens L11 on the object side and the image side surface of the biconvex positive lens L13.

  Next, a zoom lens according to embodiment 8 of the present invention will be described. 15A and 15B are cross-sectional views along the optical axis showing the optical configuration of the zoom lens according to Example 8 of the present invention when focusing on an object point at infinity, where FIG. 15A is a wide angle end, and FIG. 15B is an intermediate focal length state. (C) is a sectional view at the telephoto end.

  FIG. 16 is a diagram illustrating spherical aberration (SA), astigmatism (AS), distortion (DT), and lateral chromatic aberration (CC) when the zoom lens according to Example 8 is focused on an object point at infinity. a) shows the wide-angle end, (b) shows the intermediate focal length state, and (c) shows the state at the telephoto end.

  As shown in FIG. 15, the zoom lens of Example 8 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, and a positive refractive power. A third lens group G3 having an aperture stop S, a fourth lens group G4 having a positive refractive power, and a fifth lens group G5 having a positive refractive power.

  The first lens group G1 has, in order from the object side, a biconcave negative lens L1, a prism L2, a negative meniscus lens L3 with a convex surface facing the object side, and a paraxial radius of curvature that is equal on both surfaces with the convex surface facing the object side. It is composed of a cemented lens of a meniscus lens L4 and a biconvex positive lens L5, and has a positive refractive power as a whole.

  The negative meniscus lens L3 corresponds to the lens LA, the meniscus lens L4 corresponds to the lens LB, and the biconvex positive lens L5 corresponds to the lens LC.

  The second lens group G2 includes, in order from the object side, a negative meniscus lens L6 having a convex surface directed toward the object side, a cemented lens of a positive meniscus lens L7 having a convex surface directed toward the image side and a biconcave negative lens L8, It consists of a convex positive lens L9 and has a negative refractive power as a whole.

  The third lens group G3 includes a positive meniscus lens L10 having a convex surface directed toward the object side, and has a positive refracting power as a whole.

  The fourth lens group G4 includes a cemented lens of a positive meniscus lens L11 having a convex surface directed toward the object side, a negative meniscus lens L12 having a convex surface directed toward the object side, and a biconvex positive lens L13, and a negative lens having a convex surface directed toward the object side. It is composed of a meniscus lens L14 and has a positive refractive power as a whole.

  The fifth lens group G5 includes a positive meniscus lens L15 having a convex surface directed toward the image side, and has a positive refracting power as a whole.

  When zooming from the wide-angle end to the telephoto end, the first lens group G1 is fixed. The second lens group G2 moves to the image plane side. The third lens group G3 is fixed. The fourth lens group G4 moves to the object side. The fifth lens group moves to the image plane side.

  The aspheric surfaces include both surfaces of the negative meniscus lens L3 of the first lens group G1, both surfaces of the positive meniscus lens L7 of the second lens group G2, the image side surface of the biconcave negative lens L8, and the fourth lens group G4. Of the positive meniscus lens L11 on the object side and the image side surface of the biconvex positive lens L13.

  Next, a zoom lens according to embodiment 9 of the present invention will be described. FIGS. 17A and 17B are cross-sectional views along the optical axis showing the optical configuration of the zoom lens according to Example 9 of the present invention when focusing on an object point at infinity, where FIG. 17A is a wide-angle end, and FIG. (C) is a sectional view at the telephoto end.

  FIG. 18 is a diagram illustrating spherical aberration (SA), astigmatism (AS), distortion (DT), and lateral chromatic aberration (CC) when the zoom lens according to Example 9 is focused on an object point at infinity. a) shows the wide-angle end, (b) shows the intermediate focal length state, and (c) shows the state at the telephoto end.

  As shown in FIG. 17, the zoom lens of Example 9 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, and a positive refractive power. A third lens group G3 having an aperture stop S, a fourth lens group G4 having a positive refractive power, and a fifth lens group G5 having a positive refractive power.

  The first lens group G1 includes, in order from the object side, a plano-concave negative lens L1 having a concave surface directed toward the object side, a meniscus lens L2 having a paraxial radius of curvature and a convex surface facing the object side, and a convex surface facing the object side. This is composed of a cemented lens of a negative meniscus lens L3 and a biconvex positive lens L4, and has a positive refractive power as a whole.

  The meniscus lens L2 corresponds to the lens LB, the negative meniscus lens L3 corresponds to the lens LA, and the biconvex positive lens L4 corresponds to the lens LC.

  The second lens group G2, in order from the object side, includes a negative meniscus lens L5 having a convex surface facing the object side, a cemented lens of a positive meniscus lens L6 having a convex surface facing the image surface side, and a biconcave negative lens L7, It consists of a convex positive lens L8 and has a negative refractive power as a whole.

  The third lens group G3 includes a positive meniscus lens L9 having a convex surface directed toward the object side, and has a positive refracting power as a whole.

  The fourth lens group G4 includes a cemented lens of a positive meniscus lens L10 having a convex surface directed toward the object side, a negative meniscus lens L11 having a convex surface directed toward the object side, and a biconvex positive lens L12, and a negative lens having a convex surface directed toward the object side. It is composed of a meniscus lens L13 and has a positive refractive power as a whole.

  The fifth lens group G5 includes a positive meniscus lens L14 having a convex surface directed toward the image surface side, and has a positive refracting power as a whole.

  When zooming from the wide-angle end to the telephoto end, the first lens group G1 is fixed. The second lens group G2 moves to the image plane side. The third lens group G3 is fixed. The fourth lens group G4 moves to the object side. The fifth lens group moves to the image plane side.

  The aspheric surfaces include both surfaces of the meniscus lens L2 of the first lens group G1, both surfaces of the positive meniscus lens L6 of the second lens group G2, the image side surface of the biconcave negative lens L7, and the fourth lens group G4. It is provided on seven surfaces including the object side surface of the positive meniscus lens L10 and the image surface side surface of the biconvex positive lens L12.

  Next, a zoom lens according to embodiment 10 of the present invention will be described. 19A and 19B are cross-sectional views along the optical axis showing the optical configuration of the zoom lens according to Example 10 of the present invention when focusing on an object point at infinity. FIG. 19A is a wide-angle end, and FIG. 19B is an intermediate focal length state. (C) is a sectional view at the telephoto end.

  FIG. 20 is a diagram illustrating spherical aberration (SA), astigmatism (AS), distortion (DT), and lateral chromatic aberration (CC) when the zoom lens according to Example 10 is focused on an object point at infinity. a) shows the wide-angle end, (b) shows the intermediate focal length state, and (c) shows the state at the telephoto end.

  As shown in FIG. 19, 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, and a positive refractive power. A third lens group G3 having an aperture stop S, a fourth lens group G4 having a positive refractive power, and a fifth lens group G5 having a positive refractive power.

  The first lens group G1 includes, in order from the object side, a plano-concave negative lens L1 having a concave surface directed toward the object side, a meniscus lens L2 having a paraxial radius of curvature and a convex surface facing the object side, and a convex surface facing the object side. It is composed of a cemented lens of a directed positive meniscus lens L3 and a biconvex positive lens L4, and has a positive refractive power as a whole.

  The meniscus lens L2 corresponds to the lens LB, the positive meniscus lens L3 corresponds to the lens LA, and the biconvex positive lens L4 corresponds to the lens LC.

  The second lens group G2, in order from the object side, includes a negative meniscus lens L5 having a convex surface facing the object side, a cemented lens of a positive meniscus lens L6 having a convex surface facing the image surface side, and a biconcave negative lens L7, It consists of a convex positive lens L8 and has a negative refractive power as a whole.

  The third lens group G3 includes a positive meniscus lens L9 having a convex surface directed toward the object side, and has a positive refracting power as a whole.

  The fourth lens group G4 includes, in order from the object side, a cemented lens of a positive meniscus lens L10 having a convex surface directed toward the object side, a negative meniscus lens L11 having a convex surface directed toward the object side, and a biconvex positive lens L12; The lens is composed of a negative meniscus lens L13 having a convex surface and has a positive refractive power as a whole.

  The fifth lens group G5 includes a positive meniscus lens L14 having a convex surface directed toward the image surface side, and has a positive refracting power as a whole.

  When zooming from the wide-angle end to the telephoto end, the first lens group G1 is fixed. The second lens group G2 moves to the image plane side. The third lens group G3 is fixed. The fourth lens group G4 moves to the object side. The fifth lens group moves to the image plane side.

  The aspheric surfaces are the object side surface of the plano-concave lens L1 of the first lens group G1, the both surfaces of the meniscus lens L2, the both surfaces of the positive meniscus lens L6 of the second lens group G2, and the image surface side of the biconcave negative lens L7. , The object side surface of the positive meniscus lens L10 of the fourth lens group G4, and the image surface side surface of the biconvex positive lens L12.

  Next, numerical data of optical members constituting the zoom lens of each of the above embodiments will be listed. In the numerical data of each embodiment, r1, r2,... Are the curvature radii of the lens surfaces, d1, d2,... Are the thickness or air spacing of each lens, and nd1, nd2,. Are the Abbe number of each lens, Fno. Is the F number, f is the focal length of the entire system, and D0 is the distance from the object to the first surface. * Indicates an aspherical surface.

The aspherical shape is expressed by the following equation (I) where z is the optical axis direction, y is the direction perpendicular to the optical axis, K is the conic coefficient, and A4, A6, A8, and A10 are the aspheric coefficients. expressed.
z = (y ² / r) / [1+ {1− (1 + K) (y / r) ² } ^1/2 ]
+ A4y ⁴ + A6y ⁶ + A8y ⁸ + A10y ¹⁰ (I)
E represents a power of 10. The symbols of these specification values are common to the numerical data of the examples described later.

Numerical example 1 unit mm

Surface data surface number rd nd νd ER
Object ∞ ∞
1 * -23.1017 1.0000 2.00170 20.60 7.060
2 * 26.0696 0.2000 1. 6.839
3 ∞ 9.0000 1.90366 31.32 6.821
4 ∞ 0.2000 1. 5.972
5 * 8.6455 0.7000 1.62263 58.16 5.657
6 * 8.6455 0.1000 1.63387 23.38 5.437
7 9.8255 3.6000 1.80400 46.57 5.407
8 -35.3936 Variable 1. 5.800
9 105.1397 0.5000 1.88300 40.76 4.055
10 4.6866 2.2000 1. 3.314
11 * -37.5922 0.6000 1.53071 55.69 3.331
12 * 10.3668 0.1500 1. 3.325
13 16.2868 1.4000 1.92286 20.88 3.332
14 -27.3863 Variable 1. 3.300
15 10.7387 1.1000 1.58313 59.38 2.110
16 74.7889 0.7000 1. 1.983
17 (Aperture) ∞ Variable 1.1.836
18 * 17.3631 1.3000 1.51633 64.14 2.500
19 -7.6843 0.5000 1.92286 20.88 2.607
20 -20.5309 3.0000 1.51633 64.14 2.753
21 * -4.6271 Variable 1. 3.171
22 20.7946 0.6000 1.77250 49.60 2.766
23 5.1201 Variable 1. 2.648
24 18.5961 3.5000 1.58313 59.38 4.500
25 -7.6484 0.1500 1. 3.461
26 * -8.7703 0.5000 1.94595 17.98 3.429
27 -40.8400 Variable 1.3.544
28 ∞ 0.8000 1.51633 64.14 3.712
29 ∞ 0.4183 1. 3.790
Image plane ∞

Aspheric data

First side
K = 3.4754, A2 = 0.0000E + 00, A4 = -5.9279E-04, A6 = 2.0632E-05, A8 = -2.9000E-07,
A10 = 1.6426E-09

Second side
K = -38.0304, A2 = 0.0000E + 00, A4 = -8.1404E-04, A6 = 2.3408E-05, A8 = -3.2523E-07,
A10 = 1.8870E-09

5th page
K = 0., A2 = 0.0000E + 00, A4 = -5.7522E-04, A6 = 6.5608E-07, A8 = 9.5316E-09, A10 = -6.2795E-10

6th page
K = 0., A2 = 0.0000E + 00, A4 = -3.2034E-04, A6 = -1.1273E-06, A8 = 0.0000E + 00, A10 = 0.0000E + 00

11th page
K = 7.6678, A2 = 0.0000E + 00, A4 = -1.5985E-03, A6 = 3.1052E-04, A8 = -1.2776E-05,
A10 = 1.7129E-07

12th page
K = -7.7645, A2 = 0.0000E + 00, A4 = -1.7938E-03, A6 = 2.9956E-04, A8 = -1.6778E-05,
A10 = 2.3416E-07

18th page
K = 1.1999, A2 = 0.0000E + 00, A4 = -1.7312E-03, A6 = 2.6534E-05, A8 = -1.3626E-05,
A10 = 6.1110E-07

21st page
K = 0., A2 = 0.0000E + 00, A4 = 1.0770E-03, A6 = 2.3738E-05, A8 = -3.2983E-06, A10 = 1.9693E-07

26th page
K = 0., A2 = 0.0000E + 00, A4 = 7.2771E-04, A6 = -1.0901E-05, A8 = 0.0000E + 00, A10 = 0.0000E + 00


[Glass Material Refractive Index Table] ... Refractive index list by wavelength of medium used in this example
GLA 587.56 656.27 486.13 435.84 404.66
L8, L11 1.922860 1.910380 1.954570 1.982810 2.009190
L7 1.530710 1.527870 1.537400 1.542740 1.547272
L15 1.945950 1.931230 1.983830 2.018254 2.051060
L1 2.001700 1.988000 2.036520 2.067256 2.095660
L3 1.622630 1.619350 1.630050 1.635825 1.640600
L4 1.633870 1.626381 1.653490 1.671610 1.688826
L9, L14 1.583126 1.580139 1.589960 1.595296 1.599721
L10, L12 1.516330 1.513855 1.521905 1.526213 1.529768
CG 1.516330 1.513855 1.521905 1.526213 1.529768
L6 1.882997 1.876560 1.898221 1.910495 1.920919
L5 1.804000 1.798815 1.816080 1.825698 1.833800
L13 1.772499 1.767798 1.783374 1.791971 1.799174
L2 1.903660 1.895260 1.924120 1.941280 1.956430

Various data zoom ratios
Wide angle Medium telephoto focal length 5.34386 11.21979 24.97954
F number 3.9331 4.5025 4.9000
Angle of view (ω) 39.3 ° 18.6 ° 8.8 °
Statue height 3.84
Total lens length 53.6484 53.6425 53.6461
BF 0.41833 0.42177 0.42393

d8 0.48471 4.95994 8.87147
d14 9.00633 4.56928 0.61356
d17 5.10335 3.04547 0.99799
d21 3.86501 3.06904 0.88130
d23 1.99942 4.80580 9.08665
d27 0.97120 0.97120 0.97120

Zoom lens group data

Group Start surface Focal length
1 1 12.72559
2 9 -7.50268
3 15 21.36822
4 18 9.30253
5 22 -8.94217
6 24 40.37491

Numerical example 2
Unit mm

Surface data surface number rd nd νd ER
Object ∞ ∞
1 * -39.2317 0.9000 2.14352 17.77 6.871
2 * 24.0979 0.3000 1. 6.781
3 ∞ 9.0000 1.90366 31.32 6.755
4 ∞ 0.2000 1. 5.880
5 * 10.8957 0.7000 1.62263 58.16 5.618
6 * 10.8957 0.1000 1.63387 23.38 5.441
7 11.6532 3.3000 2.04300 39.00 5.389
8 -66.8690 Variable 1. 5.800
9 57.1700 0.5000 1.88300 40.76 4.132
10 4.6302 2.2000 1. 3.356
11 * -50.1165 0.6000 1.53071 55.69 3.367
12 * 9.3682 0.1500 1. 3.345
13 14.7763 1.4000 1.92286 20.88 3.349
14 -39.2602 Variable 1. 3.300
15 9.1823 1.1000 1.58313 59.38 2.076
16 42.5604 0.7000 1. 1.942
17 (Aperture) ∞ Variable 1. 1.806
18 * 14.0594 2.3000 1.51633 64.14 2.500
19 -6.5863 0.5000 1.92286 20.88 2.700
20 -13.9631 2.0000 1.51633 64.14 2.851
21 * -4.6097 Variable 1.3.081
22 22.1884 0.6000 1.77250 49.60 2.689
23 4.8260 Variable 1. 2.566
24 13.5579 3.5000 1.58313 59.38 4.500
25 -7.5087 0.1500 1. 3.361
26 * -8.1618 0.5000 1.94595 17.98 3.328
27 -43.1062 Variable 1. 3.449
28 ∞ 0.8000 1.51633 64.14 3.716
29 ∞ 0.3955 1. 3.800
Image plane ∞

Aspheric data

First side
K = 3.4846, A2 = 0.0000E + 00, A4 = -3.9038E-04, A6 = 4.6235E-06, A8 = -7.5045E-09,
A10 = -2.5553E-10

Second side
K = -38.3983, A2 = 0.0000E + 00, A4 = -3.5255E-04, A6 = 2.2842E-06, A8 = 3.6081E-08,
A10 = -5.6451E-10

5th page
K = 0., A2 = 0.0000E + 00, A4 = -3.8508E-04C, A6 = 1.4302E-06C, A8 = -2.4767E-08C,
A10 = 1.3250E-10C

6th page
K = 0., A2 = 0.0000E + 00, A4 = -2.8022E-04, A6 = 0.0000E + 00, A8 = 0.0000E + 00, A10 = 0.0000E + 00

11th page
K = 7.1019, A2 = 0.0000E + 00, A4 = -1.5985E-03, A6 = 3.1052E-04, A8-1.2776E-05,
A10 = 1.7129E-07

12th page
K = -5.7696, A2 = 0.0000E + 00, A4 = -1.7938E-03, A6 = 2.9956E-04, A8 = -1.6778E-05,
A10 = 2.3416E-07

18th page
K = 1.7967, A2 = 0.0000E + 00, A4 = -1.7312E-03, A6 = 2.6534E-05, A8 = -1.3626E-05,
A10 = 6.1110E-07

21st page
K = 0., A2 = 0.0000E + 00, A4 = 1.0770E-03, A6 = 2.3738E-05, A8 = -3.2983E-06, A10 = 1.9693E-07

26th page
K = 0., A2 = 0.0000E + 00, A4 = 7.2771E-04, A6 = -1.0901E-05, A8 = 0.0000E + 00, A10 = 0.0000E + 00


[Glass Material Refractive Index Table] ... Refractive index list by wavelength of medium used in this example
GLA 587.56 656.27 486.13 435.84 404.66
L5 2.042998 2.035064 2.061804 2.076930 2.089691
L8, L11 1.922860 1.910380 1.954570 1.982810 2.009190
L7 1.530710 1.527870 1.537400 1.542740 1.547272
L15 1.945950 1.931230 1.983830 2.018254 2.051060
L1 2.143520 2.125601 2.189954 2.232324 2.273184
L3 1.622630 1.619350 1.630050 1.635825 1.640600
L4 1.633870 1.626381 1.653490 1.671610 1.688826
L9, L14 1.583126 1.580139 1.589960 1.595296 1.599721
L10, L12 1.516330 1.513855 1.521905 1.526213 1.529768
CG 1.516330 1.513855 1.521905 1.526213 1.529768
L6 1.882997 1.876560 1.898221 1.910495 1.920919
L13 1.772499 1.767798 1.783374 1.791971 1.799174
L2 1.903660 1.895260 1.924120 1.941280 1.956430

Various data zoom ratios
Wide angle Medium telephoto focal length 5.29892 11.03507 24.94713
F number 4.0311 4.5921 4.9000
Angle of view (ω) 39.7 ° 18.9 ° 8.8 °
Statue height 3.84
Total lens length 52.9651 52.9670 52.9672
BF 0.39546 0.39965 0.40153

d8 0.45099 4.99087 9.12474

d14 9.11621 4.58000 0.44259
d17 5.07142 2.92911 0.96911
d21 3.03853 2.57253 0.79003
d23 1.88362 4.48595 8.23032
d27 1.50888 1.50888 1.50888

Zoom lens group data

Group Start surface Focal length
1 1 13.24761
2 9 -7.14663
3 15 19.83766
4 18 8.96115
5 22 -8.10578
6 24 33.55409

Numerical Example 3
Unit mm

Surface data surface number rd nd νd ER
Object ∞ ∞
1 -24.1340 0.9000 2.14352 17.77 7.190
2 -2376.1293 0.3000 1. 6.981
3 ∞ 9.0000 1.90366 31.32 6.909
4 ∞ 0.2000 1. 5.828
5 * 22.7484 0.7000 1.62263 58.16 5.637
6 * 22.7484 0.1000 1.63387 23.38 5.496
7 19.5587 2.8000 2.04300 39.00 5.431
8 -30.8633 Variable 1. 6.000
9 27.4572 0.5000 1.88300 40.76 4.076
10 4.7842 2.2000 1. 3.336
11 * -24.7275 0.6000 1.53071 55.69 3.286
12 * 8.2465 0.1500 1. 3.323
13 14.9711 1.4000 1.92286 20.88 3.340
14 -48.9274 Variable 1. 3.300
15 9.8959 1.1000 1.58313 59.38 2.387
16 54.1188 0.7000 1. 2.274
17 (Aperture) ∞ Variable 1. 2.152
18 * 6.2036 2.3000 1.51633 64.14 2.500
19 41.7714 0.5000 1.92286 20.88 2.481
20 15.4280 2.0000 1.51633 64.14 2.468
21 * -8.5392 2.0000 1. 2.500
22 7.6059 0.6000 1.92286 20.88 2.231
23 3.3325 Variable 1.2.041
24 -17.7275 2.0000 1.51633 64.14 2.674
25 -6.1460 Variable 1.3.095
26 ∞ 0.8000 1.51633 64.14 3.690
27 ∞ 0.3582 1. 3.783
Image plane ∞

Aspheric data

5th page
K = 0., A2 = 0.0000E + 00, A4 = -8.3256E-05C, A6 = -1.9253E-07C, A8 = 4.1689E-09C,
A10 = -6.5280E-11C

6th page
K = 0., A2 = 0.0000E + 00, A4 = -1.6762E-04, A6 = 1.4206E-06, A8 = 9.7071E-09, A10 = 0.0000E + 00

11th page
K = 11.1840, A2 = 0.0000E + 00, A4 = -5.1423E-03, A6 = 5.3508E-04, A8 = -2.4137E-05,
A10 = 3.2978E-07

12th page
K = -7.0810, A2 = 0.0000E + 00, A4 = -4.4078E-03, A6 = 5.4122E-04, A8 = -3.0268E-05,
A10 = 5.9254E-07

18th page
K = 1.3089, A2 = 0.0000E + 00, A4 = -1.5976E-03, A6 = -1.2896E-05, A8 = -3.7016E-06,
A10 = -2.3647E-07

21st page
K = 0., A2 = 0.0000E + 00, A4 = 9.4448E-04, A6 = -3.1513E-05, A8 = 7.4093E-07,
A10 = -3.1342E-07


[Glass Material Refractive Index Table] ... Refractive index list by wavelength of medium used in this example
GLA 587.56 656.27 486.13 435.84 404.66
L5 2.042998 2.035064 2.061804 2.076930 2.089691
L8, L11, L13 1.922860 1.910380 1.954570 1.982810 2.009190
L7 1.530710 1.527870 1.537400 1.542740 1.547272
L1 2.143520 2.125601 2.189954 2.232324 2.273184
L3 1.622630 1.619350 1.630050 1.635825 1.640600
L4 1.633870 1.626381 1.653490 1.671610 1.688826
L9 1.583126 1.580139 1.589960 1.595296 1.599721
L10, L12, L14 1.516330 1.513855 1.521905 1.526213 1.529768
CG 1.516330 1.513855 1.521905 1.526213 1.529768
L6 1.882997 1.876560 1.898221 1.910495 1.920919
L2 1.903660 1.895260 1.924120 1.941280 1.956430

Various data zoom ratios
Wide angle Medium telephoto focal length 5.08242 10.97327 24.94649
F number 3.5080 4.5933 4.9000
Angle of view (ω) 40.7 ° 19.4 ° 8.6 °
Statue height 3.84
Total lens length 51.5086 51.5146 51.5082
BF 0.35823 0.35780 0.35743

d8 0.37488 4.86329 10.09749
d14 10.12325 5.64334 0.40065
d17 4.81397 1.87960 0.98099
d23 2.50181 6.72046 7.69320
d25 2.48644 1.20007 1.12842

Zoom lens group data

Group Start surface Focal length
1 1 17.47975
2 9 -6.62251
3 15 20.57948
4 18 20.60626
5 24 17.20794

Numerical Example 4
Unit mm

Surface data surface number rd nd νd ER
Object ∞ ∞
1 -25.2776 0.9000 2.14352 17.77 7.172
2 140.8599 0.3000 1. 6.926
3 ∞ 9.0000 1.90366 31.32 6.901
4 ∞ 0.2000 1. 5.989
5 * 19.7018 0.1000 1.63387 23.38 5.802
6 * 19.7018 0.1000 1.52540 51.81 5.769
7 19.9306 2.8000 2.04300 39.00 5.743
8 -31.7706 Variable 1. 6.000
9 16.1350 0.5000 2.00330 28.27 4.152
10 5.1646 2.2000 1. 3.464
11 * -24.9572 0.5000 1.63387 23.38 3.385
12 * -9.7161 0.6000 1.53071 55.69 3.390
13 * 7.3900 0.1500 1. 3.356
14 16.9324 1.4000 1.94595 17.98 3.358
15 -75.5631 Variable 1. 3.300
16 10.6370 1.1000 1.58313 59.38 2.410
17 78.5572 0.7000 1. 2.300
18 (Aperture) ∞ Variable 1. 2.177
19 * 5.9963 1.7000 1.51633 64.14 2.500
20 37.5781 0.5000 1.92286 20.88 2.478
21 16.4862 1.7000 1.51633 64.14 2.471
22 * -7.4804 2.0000 1. 2.500
23 9.1028 0.6000 1.92286 20.88 2.148
24 3.2845 Variable 1. 1.964
25 -21.6106 2.0000 1.51633 64.14 2.646
26 -6.4581 Variable 1.3.060
27 ∞ 0.8000 1.51633 64.14 3.676
28 ∞ 0.4127 1. 3.772
Image plane ∞

Aspheric data

5th page
K = 0., A2 = 0.0000E + 00, A4 = -1.1398E-04, A6 = 1.0286E-06, A8 = -1.6852E-08, A10 = -5.3734E-11

6th page
K = 0., A2 = 0.0000E + 00, A4 = -1.3394E-04, A6 = 6.8098E-06, A8 = -1.1926E-07, A10 = 0.0000E + 00

11th page
K = 11.1871, A2 = 0.0000E + 00, A4 = -4.4314E-03, A6 = 3.2325E-04, A8 = -1.2760E-05,
A10 = 1.7849E-07

12th page
K = 0., A2 = 0.0000E + 00, A4 = -1.5918E-03, A6 = 0.0000E + 00, A8 = 0.0000E + 00, A10 = 0.0000E + 00

13th page
K = -7.1276, A2 = 0.0000E + 00, A4 = -3.4501E-03, A6 = 3.5835E-04, A8 = -1.7460E-05,
A10 = 3.2167E-07

19th page
K = 1.2581, A2 = 0.0000E + 00, A4 = -2.0146E-03, A6 = -3.7410E-05, A8 = -4.6237E-06,
A10 = -4.2009E-07

22nd page
K = 0., A2 = 0.0000E + 00, A4 = 6.8047E-04, A6 = -3.7821E-05, A8 = -4.4646E-06, A10 = -4.1274E-10


[Glass Material Refractive Index Table] ... Refractive index list by wavelength of medium used in this example
GLA 587.56 656.27 486.13 435.84 404.66
L5 2.042998 2.035064 2.061804 2.076930 2.089691
L12, L14 1.922860 1.910380 1.954570 1.982810 2.009190
L8 1.530710 1.527870 1.537400 1.542740 1.547272
L9 1.945950 1.931230 1.983830 2.018254 2.051060
L1 2.143520 2.125601 2.189954 2.232324 2.273184
L3, L7 1.633870 1.626381 1.653490 1.671610 1.688826
L4 1.525400 1.522390 1.532540 1.538280 1.543119
L10 1.583126 1.580139 1.589960 1.595296 1.599721
L11, L13, L15 1.516330 1.513855 1.521905 1.526213 1.529768
CG 1.516330 1.513855 1.521905 1.526213 1.529768
L6 2.003300 1.993011 2.028497 2.049714 2.068441
L2 1.903660 1.895260 1.924120 1.941280 1.956430

Various data zoom ratios
Wide angle Medium telephoto focal length 5.05214 11.04644 24.92867
F number 3.4279 4.5499 4.9000
Angle of view (ω) 40.9 ° 19.3 ° 8.6 °
Statue height 3.84
Total lens length 50.9043 50.9099 50.9040
BF 0.41274 0.41531 0.41260

d8 0.38354 4.92101 10.13134
d15 10.15777 5.62913 0.40953
d18 4.97638 1.92237 0.97818
d24 2.53447 6.97103 8.11146
d26 2.58940 1.20108 1.01091

Zoom lens group data

Group Start surface Focal length
1 1 17.56599
2 9 -6.75771
3 16 20.97306
4 19 20.51238
5 25 17.07118

Numerical Example 5
Unit mm

Surface data surface number rd nd νd ER
Object ∞ ∞
1 -24.0161 0.9000 1.92286 20.88 7.367
2 71.8718 0.4000 1. 7.002
3 ∞ 9.0000 1.90366 31.32 6.990
4 ∞ 0.2000 1. 6.043
5 * 18.2267 0.1000 1.52540 51.81 5.833
6 * 18.2267 0.1000 1.63387 23.38 5.796
7 17.3785 2.8000 1.95000 45.00 5.756
8 -30.2272 Variable 1. 6.000
9 15.2624 0.5000 2.00330 28.27 4.126
10 4.8034 2.2000 1. 3.396
11 * -27.1895 0.4000 1.63387 23.38 3.338
12 * -10.5757 0.6000 1.53071 55.69 3.344
13 * 7.5166 0.1500 1. 3.348
14 16.1243 1.4000 1.94595 17.98 3.355
15 -66.9992 Variable 1. 3.300
16 10.6258 1.1000 1.58313 59.38 2.416
17 73.4652 0.7000 1. 2.306
18 (Aperture) ∞ Variable 1. 2.183
19 * 5.8985 1.7000 1.51633 64.14 2.500
20 57.8696 0.5000 1.92286 20.88 2.485
21 18.9994 1.7000 1.51633 64.14 2.477
22 * -8.0235 2.0000 1. 2.500
23 8.3424 0.6000 1.92286 20.88 2.171
24 3.2785 Variable 1.1.983
25 -21.2563 2.0000 1.51633 64.14 2.642
26 -6.5589 Variable 1.3.057
27 ∞ 0.8000 1.51633 64.14 3.680
28 ∞ 0.3960 1. 3.776
Image plane ∞

Aspheric data

5th page
K = 0., A2 = 0.0000E + 00, A4 = -1.1810E-04, A6 = 7.7125E-07, A8 = -1.4451E-08, A10 = -6.9315E-11

6th page
K = 0., A2 = 0.0000E + 00, A4 = 1.5645E-05, A6 = -4.7693E-06, A8 = 9.1402E-08, A10 = 0.0000E + 00

11th page
K = 11.1830, A2 = 0.0000E + 00, A4 = -4.3378E-03, A6 = 3.1719E-04, A8 = -1.2327E-05,
A10 = 1.4663E-07

12th page
K = 0., A2 = 0.0000E + 00, A4 = -1.3412E-03, A6 = 0.0000E + 00, A8 = 0.0000E + 00, A10 = 0.0000E + 00

13th page
K = -7.1916, A2 = 0.0000E + 00, A4 = -3.5856E-03, A6 = 3.5939E-04, A8 = -1.7998E-05,
A10 = 3.3293E-07

19th page
K = 1.2242, A2 = 0.0000E + 00, A4 = -1.8726E-03, A6 = -4.5068E-05, A8 = -2.8538E-06,
A10 = -4.6905E-07

22nd page
K = 0., A2 = 0.0000E + 00, A4 = 7.4097E-04, A6 = -3.6817E-05, A8 = -3.2193E-06, A10 = -6.8353E-08


[Glass Material Refractive Index Table] ... Refractive index list by wavelength of medium used in this example
GLA 587.56 656.27 486.13 435.84 404.66
L5 1.949998 1.943644 1.964752 1.976299 1.985797
L1, L12, L14 1.922860 1.910380 1.954570 1.982810 2.009190
L8 1.530710 1.527870 1.537400 1.542740 1.547272
L9 1.945950 1.931230 1.983830 2.018254 2.051060
L4, L7 1.633870 1.626381 1.653490 1.671610 1.688826
L3 1.525400 1.522390 1.532540 1.538280 1.543119
L10 1.583126 1.580139 1.589960 1.595296 1.599721
L11, L13, L15 1.516330 1.513855 1.521905 1.526213 1.529768
CG 1.516330 1.513855 1.521905 1.526213 1.529768
L6 2.003300 1.993011 2.028497 2.049714 2.068441
L2 1.903660 1.895260 1.924120 1.941280 1.956430

Various data zoom ratios
Wide angle Medium telephoto focal length 4.97629 11.00758 24.94226
F number 3.4028 4.5237 4.9000
Angle of view (ω) 41.3 ° 19.2 ° 8.6 °
Statue height 3.84
Total lens length 50.9963 51.0005 50.9961
BF 0.39602 0.39843 0.39577

d8 0.37342 4.98707 10.15120
d15 10.16274 5.55427 0.38477
d18 5.03273 1.96300 0.96631
d24 2.52931 7.04670 8.29133
d26 2.65204 1.20105 0.95674

Zoom lens group data

Group Start surface Focal length
1 1 17.58175
2 9 -6.70047
3 16 21.16699
4 19 19.98144
5 25 17.55831

Numerical Example 6
Unit mm

Surface data surface number rd nd νd ER
Object ∞ ∞
1 -23.3757 0.9000 1.94595 17.98 7.285
2 84.8547 0.4000 1. 6.954
3 ∞ 9.0000 1.90366 31.32 6.932
4 ∞ 0.2000 1. 6.014
5 * 17.0728 0.1000 1.52540 51.81 5.803
6 * 17.0728 0.1000 1.71003 14.57 5.756
7 16.8871 2.8000 1.88300 40.76 5.730
8 -27.2755 Variable 1. 6.000
9 14.6645 0.5000 2.00330 28.27 4.094
10 4.7985 2.2000 1. 3.380
11 * -25.3874 0.4000 1.63387 23.38 3.321
12 * -9.7409 0.6000 1.53071 55.69 3.328
13 * 7.3518 0.1500 1. 3.343
14 16.2128 1.4000 1.94595 17.98 3.350
15 -58.6514 Variable 1. 3.300
16 10.8161 1.1000 1.58313 59.38 2.434
17 95.6995 0.7000 1. 2.326
18 (Aperture) ∞ Variable 1. 2.200
19 * 5.9101 1.7000 1.51633 64.14 2.500
20 65.8927 0.5000 1.92286 20.88 2.483
21 18.7160 1.7000 1.51633 64.14 2.476
22 * -7.8879 2.0000 1. 2.500
23 8.5878 0.6000 1.92286 20.88 2.163
24 3.2787 Variable 1. 1.976
25 -22.9858 2.0000 1.51633 64.14 2.641
26 -6.6530 Variable 1.3.053
27 ∞ 0.8000 1.51633 64.14 3.679
28 ∞ 0.3836 1. 3.775
Image plane ∞

Aspheric data

5th page
K = 0., A2 = 0.0000E + 00, A4 = -1.4695E-04, A6 = 1.3098E-06, A8 = -2.1927E-08, A10 = -2.1494E-11

6th page
K = 0., A2 = 0.0000E + 00, A4 = 5.8394E-05, A6 = -4.1736E-06, A8 = 6.5023E-08, A10 = 0.0000E + 00

11th page
K = 11.1734, A2 = 0.0000E + 00, A4 = -4.4898E-03, A6 = 3.2889E-04, A8 = -1.2870E-05,
A10 = 1.4449E-07

12th page
K = 0., A2 = 0.0000E + 00, A4 = -1.2337E-03, A6 = 0.0000E + 00, A8 = 0.0000E + 00, A10 = 0.0000E + 00

13th page
K = -7.2230, A2 = 0.0000E + 00, A4 = -3.6734E-03, A6 = 3.7115E-04, A8 = -1.8987E-05,
A10 = 3.6281E-07

19th page
K = 1.2117, A2 = 0.0000E + 00, A4 = -1.8647E-03, A6 = -4.9542E-05, A8 = -2.6821E-06,
A10 = -4.7015E-07

22nd page
K = 0., A2 = 0.0000E + 00, A4 = 7.0905E-04, A6 = -3.3360E-05, A8 = -4.6162E-06, A10 = 2.4628E-08


[Glass Material Refractive Index Table] ... Refractive index list by wavelength of medium used in this example
GLA 587.56 656.27 486.13 435.84 404.66
L4 1.710030 1.696030 1.744770 1.779970 1.816000
L12, L14 1.922860 1.910380 1.954570 1.982810 2.009190
L8 1.530710 1.527870 1.537400 1.542740 1.547272
L1, L9 1.945950 1.931230 1.983830 2.018254 2.051060
L7 1.633870 1.626381 1.653490 1.671610 1.688826
L3 1.525400 1.522390 1.532540 1.538280 1.543119
L10 1.583126 1.580139 1.589960 1.595296 1.599721
L11, L13, L15 1.516330 1.513855 1.521905 1.526213 1.529768
CG 1.516330 1.513855 1.521905 1.526213 1.529768
L5 1.882997 1.876560 1.898221 1.910495 1.920919
L6 2.003300 1.993011 2.028497 2.049714 2.068441
L2 1.903660 1.895260 1.924120 1.941280 1.956430

Various data zoom ratios
Wide angle Medium telephoto focal length 5.04661 11.08155 24.94347
F number 3.4041 4.5179 4.9000
Angle of view (ω) 40.9 ° 19.1 ° 8.6 °
Statue height 3.84
Total lens length 51.0136 51.0166 51.0136
BF 0.38359 0.38523 0.38331

d8 0.36579 4.97423 10.15721
d15 10.17915 5.57352 0.38765
d18 5.06895 1.97756 0.96059
d24 2.51521 7.05534 8.34028
d26 2.65094 1.20072 0.93452

Zoom lens group data

Group Start surface Focal length
1 1 17.69730
2 9 -6.797627
3 16 20.81258
4 19 21.02805
5 25 17.40799

Numerical Example 7
Unit mm

Surface data surface number rd nd νd ER
Object ∞ ∞
1 -23.4377 0.9000 1.94595 17.98 7.322
2 81.4672 0.4000 1. 6.988
3 ∞ 9.0000 1.90366 31.32 6.969
4 ∞ 0.2000 1. 6.067
5 * 17.2749 0.1000 1.63296 24.01 5.859
6 * 16.7231 0.1000 1.52540 51.81 5.827
7 16.7231 2.8000 1.88300 40.76 5.783
8 -27.0000 Variable 1. 6.000
9 13.9441 0.5000 2.00330 28.27 4.104
10 4.7752 2.2000 1. 3.385
11 * -24.5090 0.4000 1.63387 23.38 3.329
12 * -9.3321 0.6000 1.53071 55.69 3.335
13 * 7.2604 0.1500 1. 3.345
14 16.4205 1.4000 1.94595 17.98 3.351
15 -58.9161 Variable 1. 3.300
16 10.7440 1.1000 1.58313 59.38 2.435
17 84.9118 0.7000 1. 2.326
18 (Aperture) ∞ Variable 1. 2.201
19 * 5.9190 1.7000 1.51633 64.14 2.500
20 66.5374 0.5000 1.92286 20.88 2.479
21 18.8377 1.7000 1.51633 64.14 2.473
22 * -7.7451 2.0000 1. 2.500
23 8.5763 0.6000 1.92286 20.88 2.163
24 3.2792 Variable 1. 1.976
25 -22.3385 2.0000 1.51633 64.14 2.636
26 -6.6348 Variable 1.3.050
27 ∞ 0.8000 1.51633 64.14 3.679
28 ∞ 0.3817 1. 3.775
Image plane ∞

Aspheric data

5th page
K = 0., A2 = 0.0000E + 00, A4 = -1.5870E-04, A6 = 2.0905E-06, A8 = -3.4245E-08, A10 = -9.9027E-12

6th page
K = 0., A2 = 0.0000E + 00, A4 = -3.1458E-04, A6 = 1.2980E-05, A8 = -2.0246E-07, A10 = 0.0000E + 00

11th page
K = 11.1779, A2 = 0.0000E + 00, A4 = -4.6473E-03, A6 = 3.4226E-04, A8 = -1.3589E-05,
A10 = 1.6103E-07

12th page
K = 0., A2 = 0.0000E + 00, A4 = -1.2575E-03, A6 = 0.0000E + 00, A8 = 0.0000E + 00, A10 = 0.0000E + 00

13th page
K = -7.2520, A2 = 0.0000E + 00, A4 = -3.7894E-03, A6 = 3.8502E-04, A8 = -1.9746E-05,
A10 = 3.8046E-07

19th page
K = 1.2011, A2 = 0.0000E + 00, A4 = -1.8891E-03, A6 = -4.8956E-05, A8 = -2.8297E-06,
A10 = -4.5909E-07

22nd page
K = 0., A2 = 0.0000E + 00, A4 = 7.1796E-04, A6 = -3.5605E-05, A8 = -4.5559E-06, A10 = 3.2112E-08

[Glass Material Refractive Index Table] ... Refractive index list by wavelength of medium used in this example
GLA 587.56 656.27 486.13 435.84 404.66
L3 1.632960 1.625570 1.651930 1.668330 1.683330
L12, L14 1.922860 1.910380 1.954570 1.982810 2.009190
L8 1.530710 1.527870 1.537400 1.542740 1.547272
L1, L9 1.945950 1.931230 1.983830 2.018254 2.051060
L7 1.633870 1.626381 1.653490 1.671610 1.688826
L4 1.525400 1.522390 1.532540 1.538280 1.543119
L10 1.583126 1.580139 1.589960 1.595296 1.599721
L11, L13, L15 1.516330 1.513855 1.521905 1.526213 1.529768
CG 1.516330 1.513855 1.521905 1.526213 1.529768
L5 1.882997 1.876560 1.898221 1.910495 1.920919
L6 2.003300 1.993011 2.028497 2.049714 2.068441
L2 1.903660 1.895260 1.924120 1.941280 1.956430

Various data zoom ratios
Wide angle Medium telephoto focal length 5.02062 11.07651 24.94716
F number 3.3829 4.4928 4.9000
Angle of view (ω) 41.1 ° 19.1 ° 8.6 °
Statue height 3.84
Total lens length 51.0287 51.0329 51.0287
BF 0.38168 0.38428 0.38145

d8 0.36779 5.01068 10.15732
d15 10.17813 5.54058 0.38850
d18 5.09964 2.01938 0.95327
d24 2.50462 7.02681 8.38674
d26 2.64689 1.20112 0.91145

Zoom lens group data

Group Start surface Focal length
1 1 17.71096
2 9 -6.78996
3 16 20.97935
4 19 20.44512
5 25 17.51942

Numerical Example 8
Unit mm

Surface data surface number rd nd νd ER
Object ∞ ∞
1 -23.4667 0.9000 1.94595 17.98 7.321
2 80.6971 0.3500 1. 6.986
3 ∞ 9.0000 1.90366 31.32 6.977
4 ∞ 0.2000 1. 6.076
5 * 17.1339 0.1500 1.63387 23.38 5.866
6 * 16.7103 0.0500 1.58000 35.00 5.838
7 16.7103 2.8000 1.88300 40.76 5.790
8 -27.1458 Variable 1. 6.000
9 13.9226 0.5000 2.00330 28.27 4.106
10 4.7618 2.2000 1. 3.383
11 * -24.2645 0.4000 1.63387 23.38 3.328
12 * -9.2821 0.6000 1.53071 55.69 3.334
13 * 7.2557 0.1500 1. 3.345
14 16.3270 1.4000 1.94595 17.98 3.351
15 -58.6532 Variable 1. 3.300
16 10.6582 1.1000 1.58313 59.38 2.431
17 80.2581 0.7000 1. 2.322
16 (Aperture) ∞ Variable 1. 2.197
19 * 5.9249 1.7000 1.51633 64.14 2.500
20 68.6920 0.5000 1.92286 20.88 2.478
21 18.8540 1.7000 1.51633 64.14 2.472
22 * -7.7898 2.0000 1. 2.500
23 8.5085 0.6000 1.92286 20.88 2.168
24 3.2902 Variable 1.1.981
25 -22.1529 2.0000 1.51633 64.14 2.638
26 -6.6495 Variable 1.3.052
27 ∞ 0.8000 1.51633 64.14 3.678
28 ∞ 0.3868 1. 3.774
Image plane ∞

Aspheric data

5th page
K = 0., A2 = 0.0000E + 00, A4 = -1.4251E-04, A6 = 1.3104E-06, A8 = -2.0887E-08, A10 = -3.5286E-11

6th page
K = 0., A2 = 0.0000E + 00, A4 = -4.4141E-04, A6 = 1.7378E-05, A8 = -2.7015E-07, A10 = 0.0000E + 00

11th page
K = 11.1762, A2 = 0.0000E + 00, A4 = -4.6082E-03, A6 = 3.4239E-04, A8 = -1.3648E-05,
A10 = 1.5952E-07

12th page
K = 0., A2 = 0.0000E + 0, A4 = -1.1857E-03, A6 = 0.0000E + 00, A8 = 0.0000E + 00, A10 = 0.0000E + 00

13th page
K = -7.2564, A2 = 0.0000E + 00, A4 = -3.7624E-03, A6 = 3.8534E-04, A8 = -1.9964E-05,
A10 = 3.8809E-07

19th page
K = 1.1998, A2 = 0.0000E + 00, A4 = -1.8770E-03, A6 = -4.9644E-05, A8 = -2.5314E-06,
A10 = -4.7091E-07

22nd page
K = 0., A2 = 0.0000E + 00, A4 = 7.2029E-04, A6 = -3.8256E-05, A8 = -3.8962E-06, A10 = -8.2870E-09

[Glass Material Refractive Index Table] ... Refractive index list by wavelength of medium used in this example
GLA 587.56 656.27 486.13 435.84 404.66
L4 1.579998 1.575173 1.591743 1.601549 1.610112
L12, L14 1.922860 1.910380 1.954570 1.982810 2.009190
L8 1.530710 1.527870 1.537400 1.542740 1.547272
L1, L9 1.945950 1.931230 1.983830 2.018254 2.051060
L3, L7 1.633870 1.626381 1.653490 1.671610 1.688826
L10 1.583126 1.580139 1.589960 1.595296 1.599721
L11, L13, L15 1.516330 1.513855 1.521905 1.526213 1.529768
CG 1.516330 1.513855 1.521905 1.526213 1.529768
L5 1.882997 1.876560 1.898221 1.910495 1.920919
L6 2.003300 1.993011 2.028497 2.049714 2.068441
L2 1.903660 1.895260 1.924120 1.941280 1.956430

Various data zoom ratios
Wide angle Medium Telephoto focal length 5.01884 11.08327 24.94868
F number 3.3852 4.4910 4.9000
Angle of view (ω) 41.1 ° 19.1 ° 8.6 °
Statue height 3.84
Total lens length 50.9920 50.9954 50.9920
BF 0.38683 0.38895 0.38662

d8 0.36665 5.02402 10.15860
d15 10.18122 5.52736 0.38918
d18 5.10507 2.02817 0.95258
d24 2.50682 7.02601 8.39691
d26 2.64545 1.20094 0.90812

Zoom lens group data

Group Start surface Focal length
1 1 17.74685
2 9 -6.78050
3 16 20.95456
4 19 20.38098
5 25 17.62771

Numerical Example 9
Unit mm

Surface data surface number rd nd νd ER
Object ∞ ∞
1 -20.7092 9.0000 1.92286 20.88 7.671
2 ∞ 0.2000 1. 6.593
3 * 17.9221 0.8000 1.69400 56.29 6.349
4 * 17.9221 0.0800 1.71003 14.57 6.158
5 16.9240 2.8000 1.88300 40.76 6.113
6 -27.9800 Variable 1. 6.000
7 14.6389 0.5000 2.00330 28.27 4.297
8 4.3931 2.4000 1. 3.430
9 * -35.1107 0.4000 1.63387 23.38 3.397
10 * -13.8276 0.6000 1.53071 55.69 3.404
11 * 8.8432 0.1500 1. 3.437
12 16.1136 1.2000 1.94595 17.98 3.448
13 -81.1831 Variable 1. 3.400
14 10.2369 1.1000 1.58313 59.38 2.354
15 55.7367 0.7000 1. 2.237
16 (Aperture) ∞ Variable 1. 2.111
17 * 5.9628 1.7000 1.51633 64.14 2.700
18 116.4435 0.5000 1.92286 20.88 2.685
19 21.7359 1.7000 1.51633 64.14 2.678
20 * -9.2709 2.0000 1. 2.700
21 6.8485 0.6000 1.92286 20.88 2.350
22 3.2762 Variable 1. 2.121
23 -24.4406 2.0000 1.51633 64.14 2.715
24 -6.8903 Variable 1. 3.109
25 ∞ 0.8000 1.51633 64.14 3.695
26 ∞ 0.3860 1. 3.784
Image plane ∞

Aspheric data

Third side
K = 0., A2 = 0.0000E + 00, A4 = -8.5221E-05, A6 = -2.0140E-07, A8 = 3.1539E-09, A10 = -4.6336E-11

4th page
K = 0., A2 = 0.0000E + 00, A4 = -5.0509E-05, A6 = -6.7452E-08, A8 = 9.4814E-09, A10 = 0.0000E + 00

9th page
K = 11.1750, A2 = 0.0000E + 00, A4 = -2.5516E-03, A6 = 1.7765E-04, A8 = -5.3872E-06,
A10 = 3.6485E-09

10th page
K = 0., A2 = 0.0000E + 00, A4 = -1.2073E-03, A6 = 0.0000E + 00, A8 = 0.0000E + 00, A10 = 0.0000E + 00

11th page
K = -7.2615, A2 = 0.0000E + 00, A4 = -2.3804E-03, A6 = 1.9213E-04, A8 = -9.2092E-06,
A10 = 1.0294E-07

17th page
K = 1.1912, A2 = 0.0000E + 00, A4 = -1.7017E-03, A6 = -3.1240E-05, A8 = -4.4849E-06,
A10 = -3.2694E-07

20th page
K = 0., A2 = 0.0000E + 00, A4 = 4.5207E-04, A6 = 9.1159E-06, A8 = -8.6314E-06, A10 = 1.6114E-07

[Glass Material Refractive Index Table] ... Refractive index list by wavelength of medium used in this example
GLA 587.56 656.27 486.13 435.84 404.66
L3 1.710030 1.696030 1.744770 1.779970 1.816000
L1, L11, L13 1.922860 1.910380 1.954570 1.982810 2.009190
L7 1.530710 1.527870 1.537400 1.542740 1.547272
L8 1.945950 1.931230 1.983830 2.018254 2.051060
L2 1.694000 1.690240 1.702570 1.709300 1.714890
L6 1.633870 1.626381 1.653490 1.671610 1.688826
L9 1.583126 1.580139 1.589960 1.595296 1.599721
L10, L12, L14 1.516330 1.513855 1.521905 1.526213 1.529768
CG 1.516330 1.513855 1.521905 1.526213 1.529768
L4 1.882997 1.876560 1.898221 1.910495 1.920919
L5 2.003300 1.993011 2.028497 2.049714 2.068441

Various data zoom ratios
Wide angle intermediate telephoto focal length 4.97593 11.06734 24.96023
F number 3.4104 4.4910 4.9000
Angle of view (ω) 41.3 ° 19.1 ° 8.6 °
Statue height 3.84
Total lens length 50.4897 50.4917 50.4896
BF 0.38603 0.38786 0.38581

d6 0.37129 5.12147 10.17372
d13 10.19280 5.44303 0.39024
d16 5.07082 2.06238 0.96234
d22 2.52631 7.04611 8.44334
d24 2.71243 1.20084 0.90415

Zoom lens group data

Group Start surface Focal length
1 1 18.61461
2 7 -6.62863
3 14 21.31509
4 17 19.18332
5 23 17.88992

Numerical Example 10
Unit mm

Surface data surface number rd nd νd ER
Object ∞ ∞
1 * -16.1754 8.3000 2.00170 20.60 7.105
2 ∞ 0.2000 1. 6.328
3 * 13.9396 0.1000 1.52540 51.81 6.117
4 * 13.9396 0.1000 1.63387 23.38 6.085
5 15.0306 2.8000 1.88300 40.76 6.042
6 -27.7536 Variable 1. 6.000
7 13.4386 0.5000 2.00330 28.27 4.252
8 4.3351 2.2000 1. 3.399
9 * -30.9908 0.4000 1.63387 23.38 3.385
10 * -12.1774 0.6000 1.53071 55.69 3.394
11 * 8.2943 0.1500 1. 3.444
12 15.2698 1.4000 1.94595 17.98 3.459
13 -89.7401 Variable 1. 3.400
14 10.8205 1.1000 1.58313 59.38 2.396
15 83.3768 0.7000 1. 2.285
16 (Aperture) ∞ Variable 1. 2.158
17 * 5.6897 1.7000 1.51633 64.14 2.700
18 215.4615 0.5000 1.92286 20.88 2.671
19 23.1532 1.7000 1.51633 64.14 2.656
20 * -10.9886 2.0000 1. 2.700
21 6.9464 0.6000 1.92286 20.88 2.356
22 3.3641 Variable 1. 2.138
23 -23.5756 2.0000 1.51633 64.14 2.740
24 -6.9022 Variable 1. 3.128
25 ∞ 0.8000 1.51633 64.14 3.702
26 ∞ 0.3961 1. 3.787
Image plane ∞

First side
K = 0., A2 = 0.0000E + 00, A4 = 1.0724E-04, A6 = -9.3315E-07, A8 = 2.3779E-09, A10 = 2.6778E-11

Third side
K = 0., A2 = 0.0000E + 00, A4 = -2.3898E-04, A6 = 1.1874E-06, A8 = -1.1149E-08, A10 = -9.9118E-11

4th page
K = 0., A2 = 0.0000E + 00, A4 = -1.7842E-04, A6 = -1.8721E-06, A8 = 5.7740E-08, A10 = 0.0000E + 00

9th page
K = 11.1826, A2 = 0.0000E + 00, A4 = -3.4223E-03, A6 = 2.5437E-04, A8 = -7.7472E-06,
A10 = -6.4844E-09

10th page
K = 0., A2 = 0.0000E + 00, A4 = -1.1875E-03, A6 = 0.0000E + 00, A8 = 0.0000E + 00, A10 = 0.0000E + 00

11th page
K = -7.2589, A2 = 0.0000E + 00, A4 = -3.1286E-03, A6 = 2.8894E-04, A8 = -1.4054E-05,
A10 = 1.8299E-07

17th page
K = 1.1562, A2 = 0.0000E + 00, A4 = -1.5559E-03, A6 = -1.7830E-05, A8 = -4.2795E-06,
A10 = -3.1002E-07

20th page
K = 0., A2 = 0.0000E + 00, A4 = 7.7365E-04, A6 = 2.4786E-05, A8 = -6.1740E-06, A10 = 5.6251E-08

[Glass Material Refractive Index Table] ... Refractive index list by wavelength of medium used in this example
GLA 587.56 656.27 486.13 435.84 404.66
L11, L13 1.922860 1.910380 1.954570 1.982810 2.009190
L7 1.530710 1.527870 1.537400 1.542740 1.547272
L8 1.945950 1.931230 1.983830 2.018254 2.051060
L1 2.001700 1.988000 2.036520 2.067256 2.095660
L3, L6 1.633870 1.626381 1.653490 1.671610 1.688826
L2 1.525400 1.522390 1.532540 1.538280 1.543119
L9 1.583126 1.580139 1.589960 1.595296 1.599721
L10, L12, L14 1.516330 1.513855 1.521905 1.526213 1.529768
CG 1.516330 1.513855 1.521905 1.526213 1.529768
L4 1.882997 1.876560 1.898221 1.910495 1.920919
L5 2.003300 1.993011 2.028497 2.049714 2.068441

Various data zoom ratios
Wide angle Medium telephoto focal length 4.88482 11.09271 24.93563
F number 3.3987 4.5262 4.9000
Angle of view (ω) 41.9 ° 19.1 ° 8.6 °
Statue height 3.84
Total lens length 49.2684 49.2713 49.2684
BF 0.39612 0.39728 0.39599

d6 0.37488 5.16073 10.18976
d13 10.19313 5.40950 0.37815
d16 5.09429 1.91960 0.99138
d22 2.58678 7.33366 8.63562
d24 2.77318 1.20049 0.82747

Zoom lens group data

Group Start surface Focal length
1 1 17.70933
2 7 -6.59440
3 14 21.20498
4 17 19.57743
5 23 18.15999

Next, the values of the conditional expressions in each example are listed.

Example 1 Example 2 Example 3
fw 5.344 5.299 5.082
y10 3.84 3.84 3.84
γ 4.674 4.708 4.909
(1) {1 / νd (12A)} − {1 / νd (12B)} 0.02558 0.02558 0.02558
(2) nd (12A) − nd (12B) 0.01124 0.01124 0.01124
(3) b (12A) 2.03834 2.03834 2.03834
(4) nd (12A) 1.63387 1.63387 1.63387
(5) νd (12A) 23.38 23.38 23.38
θgF (12A) 0.6684 0.6684 0.6684
(6) β (12A) 0.8243 0.8243 0.8243
(7) θhg (12A) 0.6351 0.6351 0.6351
βhg (12A) 0.9002 0.9002 0.9002
nd (12B) 1.62263 1.62263 1.62263
a 1.8479 1.8723 2.0049
h (= 2.5a) 4.6198 4.6807 5.0123
R12A 8.6455 10.8957 22.7484
Δz12A (h) -0.15687 -0.13450 -0.07940
P (LA) -4.0127e-3 -3.4405e-3 -2.0311e-3
(12) (R12AF + R12AR) / (R12AF−R12AR) -0.06388 -0.03359 0.07539
(13) f12C / f12B 0.02219 0.01370 3.818e-3
(14) b (12C) 2.16119 2.34213 2.34213
(15) nd (12C) 1.80400 2.04300 2.04300
νd (12C) 46.57 39.00 39.00
(16) {1 / νd (11)} − {1 / νd (12C)} 0.02707 0.03063 0.03063
(17) fw / f12A 0.04860 0.02106 -0.02281
Dp 4.7277 4.7277 4.7277
(18a) f11 / Dp -2.5603 -2.7406 -4.5108
(18b) f12 / Dp 1.9620 2.0125 2.6578
(19) (R11F + R11R) / (R11F-R11R) -0.06036 0.23897 -1.0205
(20) f2 / f1 -0.58957 -0.53947 -0.37887
y07 2.688 2.688 2.688
tanω ₀₇ 0.52814 0.53168 0.57255
(23) y ₀₇ / (fw · _{tanω 07w} ) 0.9524 0.9541 0.9238


Example 4 Example 5 Example 6
fw 5.052 4.976 5.047
y10 3.84 3.84 3.84
γ 4.934 5.012 4.942
(1) {1 / νd (12A)} − {1 / νd (12B)} 0.02347 0.02347 0.04933
(2) nd (12A) − nd (12B) 0.10847 0.10847 0.18463
(3) b (12A) 2.03834 2.03834 1.96209
(4) nd (12A) 1.63387 1.63387 1.71003
(5) νd (12A) 23.38 23.38 14.57
θgF (12A) 0.6684 0.6684 0.7222
(6) β (12A) 0.8243 0.8243 0.8194
(7) θhg (12A) 0.6351 0.6351 0.7392
βhg (12A) 0.9002 0.9002 0.9044
nd (12B) 1.52540 1.52540 1.52540
a 2.0233 2.0744 2.0273
h (= 2.5a) 5.0583 5.1860 5.0683
R12A 19.7018 18.2267 17.0728
Δz12A (h) -0.02473 -0.03364 -0.00390
P (LA) -0.5804e-3 -0.7895e-3 -0.1924e-3
(12) (R12AF + R12AR) / (R12AF-R12AR) 0.00000 0.02382 0.00547
(13) f12C / f12B 4.254e-3 6.514e-4 7.558e-4
(14) b (12C) 2.34213 2.29515 2.19563
(15) nd (12C) 2.04300 1.95000 1.88300
νd (12C) 39.00 45.00 40.76
(16) {1 / νd (11)} − {1 / νd (12C)} 0.03063 0.02567 0.03108
(17) fw / f12A 0.00032 -0.00806 -0.00179
Dp 4.7277 4.7277 4.7277
(18a) f11 / Dp -3.9528 -4.1073 -4.0182
(18b) f12 / Dp 2.5517 2.5858 2.5953
(19) (R11F + R11R) / (R11F−R11R) -0.69570 -0.49908 -0.56804
f2 / f1 -0.38470 -0.38110 -0.38410
(20) y ₀₇ 2.688 2.688 2.688
tanω ₀₇ 0.57574 0.58410 0.57615
(23) y ₀₇ / (fw · _{tanω 07w} ) 0.9241 0.9248 0.9244

Example 7 Example 8 Example 9 Example 10
fw 5.021 5.019 4.976 4.885
y10 3.84 3.84 3.84 3.84
γ 4.969 4.971 5.016 5.105
(1) {1 / νd (12A)}-{1 / νd (12B)}
0.02235 0.01420 0.05087 0.02347
(2) nd (12A) − nd (12B) 0.10756 0.05387 0.01603 0.10847
(3) b (12A) 2.04833 2.03834 1.96209 2.03834
(4) nd (12A) 1.63296 1.63387 1.71003 1.63387
(5) νd (12A) 24.01 23.38 14.57 23.38
θgF (12A) 0.6222 0.6684 0.7222 0.6684
(6) β (12A) 0.7823 0.8243 0.8194 0.8243
(7) θhg (12A) 0.5690 0.6351 0.7392 0.6351
βhg (12A) 0.8413 0.9002 0.9044 0.9002
nd (12B) 1.52540 1.58000 1.69400 1.52540
a 2.0448 2.0461 2.0754 2.1371
h (= 2.5a) 5.1120 5.1153 5.1885 5.3428
R12A 16.7231 16.7103 17.9221 13.9396
Δz12A (h) -0.07761 -0.11754 -0.03294 -0.15059
P (LA) -1.7346e-3 -1.6691e-3 -1.6757e-3 -3.5343e-3
(12) (R12AF + R12AR) / (R12AF-R12AR)
0.01623 0.01252 0.02864 -0.03766

(13) f12C / f12B 7.802e-4 4.604e-4 8.712e-3 1.061e-3
(14) b (12C) 2.19563 2.19563 2.19563 2.19563
(15) nd (12C) 1.88300 1.88300 1.88300 1.88300
νd (12C) 40.76 40.76 40.76 40.76
(16) {1 / νd (11)}-{1 / νd (12C)}
0.03108 0.03108 0.02336 0.02401
(17) fw / f12A -0.00564 -0.00406 -0.01124 0.01670
Dp 4.7277 4.7277 4.6805 4.1465
(18a) f11 / Dp -4.0530 -4.0481 -4.7944 -3.8944
(18b) f12 / Dp 2.5929 2.5887 2.7318 2.6602
(19) (R11F + R11R) / (R11F-R11R)
-0.55316 -0.54943 *********
(20) f2 / f1 -0.38338 -0.38207 -0.35610 -0.37237
y ₀₇ 2.688 2.688 2.688 2.688
tanω ₀₇ 0.57926 0.57944 0.58562 0.59175
(23) y ₀₇ / (fw · _{tanω 07w} ) 0.9242 0.9243 0.9224 0.9299

  The imaging optical system of the present invention as described above is a photographing apparatus for photographing an image of an object with an electronic image sensor such as a CCD or a CMOS, especially a digital camera, a video camera, a personal computer or an example of an information processing apparatus, a telephone. It can be used for portable terminals, especially mobile phones that are convenient to carry. The embodiment is illustrated below.

  FIG. 21 to FIG. 23 show conceptual diagrams of a configuration in which the imaging optical system according to the present invention is incorporated in a photographing optical system 41 of a digital camera. 21 is a front perspective view showing the appearance of the digital camera 40, FIG. 22 is a rear perspective view thereof, and FIG. 23 is a cross-sectional view showing an optical configuration of the digital camera 40.

  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 45, a flash 46, a liquid crystal display monitor 47, and the like. Then, when the photographer presses the shutter 45 disposed on the upper part of the camera 40, photographing is performed through the photographing optical system 41, for example, the zoom lens 48 of the first embodiment in conjunction therewith.

  The object image formed by the photographing optical system 41 is formed on the image pickup surface of the CCD 49. 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 image processing means 51. Further, the image processing means 51 is provided with a memory or the like, and can record a captured electronic image. This memory may be provided separately from the image processing means 51, or may be configured to perform recording and writing electronically using a flexible disk, memory card, MO, or the like.

  Further, a finder objective optical system 53 is disposed on the finder optical path 44. The finder objective optical system 53 includes a cover lens 54, a first prism 10, an aperture stop 2, a second prism 20, and a focusing lens 66. An object image is formed on the imaging surface 67 by the finder objective optical system 53. This object image is formed on the field frame 57 of the Porro prism 55 which is an image erecting member. Behind the Porro prism 55, an eyepiece optical system 59 for guiding the image formed into an erect image to the observer eyeball E is disposed.

  According to the digital camera 40 configured as described above, an electronic imaging device having a compact and thin zoom lens in which the number of components of the photographing optical system 41 is reduced can be realized. The present invention is not limited to the above-described retractable digital camera, but can also be applied to a folding digital camera that employs a bending optical system.

  Next, a personal computer which is an example of an information processing apparatus in which the imaging optical system of the present invention is incorporated as an objective optical system is shown in FIGS. 24 is a front perspective view of the personal computer 300 with the cover open, FIG. 15 is a sectional view of the photographing optical system 303 of the personal computer 300, and FIG. 26 is a side view of FIG. As shown in FIGS. 24 to 26, the personal computer 300 includes a keyboard 301, information processing means and recording means, a monitor 302, and a photographing optical system 303.

  Here, the keyboard 301 is for an operator to input information from the outside. The information processing means and recording means are not shown. The monitor 302 is for displaying information to the operator. The photographing optical system 303 is for photographing an image of the operator himself or a surrounding area. The monitor 302 may be a liquid crystal display element, a CRT display, or the like. Examples of the liquid crystal display element include a transmissive liquid crystal display element that illuminates from the back with a backlight (not shown), and a reflective liquid crystal display element that reflects and displays light from the front. Further, in the drawing, the photographing optical system 303 is built in the upper right of the monitor 302. However, the imaging optical system 303 is not limited to the place, and may be anywhere around the monitor 302 or the keyboard 301.

  The photographing optical system 303 includes, on the photographing optical path 304, the objective optical system 100 including, for example, the zoom lens according to the first embodiment, and the electronic imaging element chip 162 that receives an image. These are built in the personal computer 300.

A cover glass 102 for protecting the objective optical system 100 is disposed at the tip of the mirror frame.
The object image received by the electronic image sensor chip 162 is input to the processing means of the personal computer 300 via the terminal 166. Finally, the object image is displayed on the monitor 302 as an electronic image. FIG. 24 shows an image 305 taken by the operator as an example. The image 305 can also be displayed on a communication partner's personal computer from a remote location via the processing means. The Internet and telephone are used for image transmission to remote places.

  Next, FIG. 27 shows a telephone which is an example of an information processing apparatus in which the imaging optical system of the present invention is incorporated as a photographing optical system, particularly a portable telephone which is convenient to carry. 27A is a front view of the mobile phone 400, FIG. 27B is a side view, and FIG. 27C is a cross-sectional view of the photographing optical system 405. As shown in FIGS. 27A to 27C, the mobile phone 400 includes a microphone unit 401, a speaker unit 402, an input dial 403, a monitor 404, a photographing optical system 405, an antenna 406, and processing. Means.

  Here, the microphone unit 401 is for inputting an operator's voice as information. The speaker unit 402 is for outputting the voice of the other party. An input dial 403 is used by an operator to input information. The monitor 404 is for displaying information such as a photographed image of the operator himself or the other party, a telephone number, and the like. The antenna 406 is for transmitting and receiving communication radio waves. The processing means (not shown) is for processing image information, communication information, input signals, and the like.

  Here, the monitor 404 is a liquid crystal display element. In the drawing, the arrangement positions of the respective components are not particularly limited to these. The photographing optical system 405 includes the objective optical system 100 disposed on the photographing optical path 407 and an electronic image sensor chip 162 that receives an object image. As the objective optical system 100, for example, the zoom lens of Example 1 is used. These are built in the mobile phone 400.

A cover glass 102 for protecting the objective optical system 100 is disposed at the tip of the mirror frame.
The object image received by the electronic imaging element chip 162 is input to an image processing unit (not shown) via the terminal 166. Finally, the object image is displayed as an electronic image on the monitor 404, the monitor of the communication partner, or both. The processing means includes a signal processing function. When transmitting an image to a communication partner, this function converts information on the object image received by the electronic image sensor chip 162 into a signal that can be transmitted.

  The present invention can take various modifications without departing from the spirit of the present invention.

  As described above, the imaging optical system and the electronic imaging apparatus having the imaging optical system according to the present invention are capable of increasing the magnification ratio, reducing the thickness, improving the performance of the imaging optical system, and reducing the thickness of the electronic imaging apparatus. Useful.

G1 1st lens group G2 2nd lens group G3 3rd lens group G4 4th lens group G5 5th lens group L1 to L15 Each lens LPF Low pass filter CG Cover glass I Imaging surface E Observer's eye 40 Digital camera 41 Shooting optics System 42 Optical path for photographing 43 Viewfinder optical system 44 Optical path for viewfinder 45 Shutter 46 Flash 47 LCD monitor 48 Zoom lens 49 CCD
DESCRIPTION OF SYMBOLS 50 Imaging surface 51 Processing means 53 Finder objective optical system 55 Porro prism 57 Field frame 59 Eyepiece optical system 66 Focusing lens 67 Imaging surface 100 Objective optical system 102 Cover glass 162 Electronic imaging device chip 166 Terminal 300 Personal computer 301 Keyboard 302 Monitor 303 Imaging Optical System 304 Imaging Optical Path 305 Image 400 Mobile Phone 401 Microphone Unit 402 Speaker Unit 403 Input Dial 404 Monitor 405 Imaging Optical System 406 Antenna 407 Imaging Optical Path

Claims (15)

An imaging optical system including, in order from the object side, a lens group G1 having a positive refractive power, a lens group G2 having a negative refractive power, and a rear lens group GR having a positive refractive power as a whole as a whole. Because
The lens group G1 includes a sub lens group G11 and a sub lens group G12.
The lens group G2 is movable at the time of zooming,
The rear lens group GR is composed of three or four sub lens groups whose mutual optical axis distances change upon zooming,
The sub-lens group G11 is composed of a lens component having negative refracting power and a prism for bending the optical path, or composed of prisms having negative refracting power and bending the optical path,
The sub lens group G12 has a positive refractive power, and includes a cemented lens component of the lens LA and the lens LB, and a positive lens LC.
The joint surface between the lens LA and the lens LB is aspheric,
The positive lens LC has a stronger refractive power than the lens LA and the lens LB,
An imaging optical system characterized by satisfying the following conditional expression (1):
0.008 <{1 / νd (12A)} − {1 / νd (12B)} (1)
here,
νd (12A) is the Abbe number (nd (12A) −1) / (nF (12A) −nC (12A)) of the lens LA,
nd (12A), nC (12A), nF (12A), and ng (12A) are the refractive indexes of the d-line, C-line, F-line, and g-line of the lens LA, respectively.
νd (12B) is the Abbe number (nd (12B) −1) / (nF (12B) −nC (12B)) of the lens LB,
nd (12B), nC (12B), nF (12B), and ng (12B) are the refractive indices of the d-line, C-line, F-line, and g-line of the lens LB, respectively.
It is. The imaging optical system according to claim 1, wherein the following condition is satisfied.
| Nd (12A) −nd (12B) | ≦ 0.30 (2)
here,
nd (12A) is the refractive index of the lens LA at the d-line,
nd (12B) is the refractive index of the lens LB at the d-line,
It is. In an orthogonal coordinate system with the horizontal axis νd and the vertical axis nd,
nd (12A) = a (12A) × νd (12A) + b (12A) (however, a (12A) = − 0.0173)
When the straight line represented by the following formula (3) is set, the area defined by the straight line when the lower limit value and the straight line when the upper limit value are satisfied, and the following conditional expression (4) and 3. The imaging optical system according to claim 1, wherein nd (12A) and νd (12A) of the lens LA are included in both of the regions determined by (5).
1.64 <b (12A) <2.18 (3)
1.57 <nd (12A) <2.00 (4)
3 <νd (12A) <27 (5)
here,
nd (12A) is the refractive index of the lens LA at the d-line,
νd (12A) is the Abbe number (nd (12A) −1) / (nF (12A) −nC (12A)) of the lens LA,
nd (12A), nC (12A), nF (12A), and ng (12A) are the refractive indexes of the d-line, C-line, F-line, and g-line of the lens LA, respectively.
It is. In an orthogonal coordinate system in which the horizontal axis is νd and the vertical axis is θgF,
θgF (12A) = α (12A) × νd (12A) + β (12A) (where α (12A) = − 0.00667)
When the straight line represented by is set, the region defined by the straight line when the range is the lower limit of the range of the following conditional expression (6) and the straight line when the upper limit is set, and the following conditional expression (5) The imaging optical system according to claim 3, wherein θgF (12A) and νd (12A) of the lens LA are included in both the fixed region and the region.
0.7840 <β (12A) <0.9000 (6)
3 <νd (12A) <27 (5)
here,
θgF (12A) is the partial dispersion ratio (ng (12A) −nF (12A)) / (nF (12A) −nC (12A)) of the lens LA,
νd (12A) is the Abbe number of the lens LA, (nd (12A) −1) / (nF (12A) −nC (12A)),
nd (12A), nC (12A), nF (12A), and ng (12A) are the refractive indexes of the d-line, C-line, F-line, and g-line of the lens LA, respectively.
It is. Different from the orthogonal coordinates (orthogonal coordinates where the horizontal axis is νd and the vertical axis is θgF), the orthogonal coordinate system where the horizontal axis is νd and the vertical axis is θhg,
θhg (12A) = αhg (12A) × νd (12A) + βhg (12A) (where αhg (12A) = − 0.01134)
When the straight line represented by is set, the region defined by the straight line when the range is the lower limit of the range of the following conditional expression (7) and the straight line when the upper limit is set, and the following conditional expression (5) The imaging optical system according to claim 4, wherein θhg (12A) and νd (12A) of the lens LA are included in both the fixed region and the region.
0.8450 <βhg (12A) <0.9800 (7)
3 <νd (12A) <27 (5)
here,
θhg (12A) is a partial dispersion ratio (nh (12A) −ng (12A)) / (nF (12A) −nC (12A)) of the lens LA,
nh (12A) is the refractive index of h-line of the lens LA,
It is. The lens LA has a meniscus shape,
The imaging optical system according to claim 1, wherein the following condition (12) is satisfied.
| (R12AF−R12AR) / (R12AF + R12AR) | <0.2 (12)
here,
R12AF is the radius of curvature on the optical axis on the object side of the lens LA,
R12AR is the radius of curvature on the optical axis on the image side of the lens LA,
It is. The imaging optical system according to claim 1, wherein the following condition is satisfied.
-0.2 <f12C / f12B <0.2 (13)
here,
f12B is the focal length of the lens LB;
f12C is the focal length of the positive lens LC,
It is. In an orthogonal coordinate system with the horizontal axis νd and the vertical axis nd,
nd (12C) = a (12C) × νd (12C) + b (12C) (where a (12C) = − 0.00767)
When the straight line represented by is set, the region defined by the straight line when the range is the lower limit of the range of the following conditional expression (14) and the straight line when the upper limit is set, and the following conditional expression (15) The imaging optical system according to claim 7, wherein nd (12C) and νd (12C) of the positive lens LC are included in two regions including a fixed region.
2.10 <b (12C) (14)
1.70 <nd (12C) (15)
here,
νd (12C) is the Abbe number (nd (12C) −1) / (nF (12C) −nC (12C)) of the positive lens LC,
nd (12C), nC (12C), and nF (12C) are refractive indexes of the d-line, C-line, and F-line of the positive lens LC, respectively.
It is. In the sub lens group G11, the lens component having the negative refractive power or the prism for bending the optical path having the negative refractive power is an element having a negative refractive power,
The imaging optical system according to claim 7, wherein the following conditional expression (16) is satisfied.
0.017 <{1 / νd (11)} − {1 / νd (12C)} <0.052 (16)
here,
νd (11) is the Abbe number (nd (11) −1) / (nF (11) −nC (11)) of the element having the refractive power,
νd (12C) is the Abbe number (nd (12C) −1) / (nF (12C) −nC (12C)) of the positive lens LC,
nd (11), nC (11), and nF (11) are the refractive indices of the d-line, C-line, and F-line of the element having negative refractive power,
nd (12C), nC (12C), and nF (12C) are refractive indexes of the d-line, C-line, and F-line of the positive lens LC, respectively.
It is. The imaging optical system according to claim 1, wherein the following conditional expression (17) is satisfied.
-0.2 <fw / f12A <0.2 (17)
here,
fw is the focal length of the entire system at the wide angle end of the imaging optical system,
f12A is the focal length of the lens LA in the air,
It is. The imaging optical system according to claim 1, wherein at least one of the following conditional expression (18a) and conditional expression (18b) is satisfied.
-7.0 <f11 / Dp <-1.5 (18a)
1.2 <f12 / Dp <5.0 (18b)
here,
f11 is the focal length of the sub lens group G11,
f12 is the focal length of the sub lens group G12,
Dp is the air equivalent distance along the optical axis from the entrance surface to the exit surface of the prism,
It is. The imaging optical system according to claim 1, wherein the following condition is satisfied.
-2.0 <(R11F + R11R) / (R11F-R11R) <2.0 (19)
here,
R11F is a radius of curvature on the optical axis of the surface closest to the object side of the sub lens group G11,
R11R is a radius of curvature on the optical axis of the surface closest to the image side of the sub lens group G11,
It is. The imaging optical system according to claim 1, wherein the following condition is satisfied.
-1.0 <f2 / f1 <-0.20 (20)
here,
f1 is the focal length of the positive lens group G1,
f2 is the focal length of the negative lens group G2,
It is. The imaging optical system according to any one of claims 1 to 13 and an electronic imaging device,
An optical axis direction is z, a coordinate axis with h being a direction perpendicular to the optical axis, R is a radius of curvature of the spherical component on the optical axis, K is a conic constant, A ₄ , A ₆ , A ₈ , A _10. As the aspheric coefficient, the shape of the aspheric surface is expressed by the following equation (8), and
z = (h ² / R) / {1+ [1- (1 + K) (h / R) ² ] ^1/2 }
+ A ₄ h ⁴ + A ₆ h ⁶ + A ₈ h ⁸ + A ₁₀ h ¹⁰ (8)
When the deviation amount is expressed by the following formula (9),
Δz = z−h ² / R {1+ (1−h ² / R ² ) ^1/2 } (9)
An electronic imaging device characterized by satisfying the following conditional expression (10):
When R _12A ≧ 0
-5.0e-2 <P (LA) / y 10 <0 < However, h = 2.5a> ··· (10 )
here,
P (LA) is a parameter related to the shape and dispersion of the joint surface, and is represented by the following equation:
P (LA) = Δz _12A (h) ・ (1 / νd (12A) −1 / νd (12B))
z _12A is the shape of the joint surface, the shape according to formula (8),
Δz _12A (h) is the amount of deviation of the joint surface, and the amount of deviation according to equation (9),
R _12A is the paraxial radius of curvature of the joint surface,
a is an amount according to the following conditional expression (11),
a = (y ₁₀ ) ² · log ₁₀ γ / fw (11)
Both air contact surfaces may be spherical,
y ₁₀ is the distance (maximum image height) from the center to the farthest point in the effective imaging plane (in the plane where imaging is possible) of the electronic imaging device arranged in the vicinity of the imaging position of the imaging optical system;
fw is the focal length of the entire system at the wide angle end of the imaging optical system,
γ is the imaging ratio (total focal length at the telephoto end / total focal length at the wide angle end),
Also, since the top of each surface is the origin, z (0) = 0 is always set.
It is. The imaging optical system according to any one of claims 1 to 14, an electronic imaging device, and image data obtained by imaging an image formed through the imaging optical system with the electronic imaging device. And image processing means for outputting image data obtained by processing and changing the shape of the image, and the imaging optical system satisfies the following conditional expression (23) when focusing on an object point at infinity: An electronic imaging device.
0.85 <y ₀₇ / (fw · tan ω _07w ) <0.97 (23)
here,
y ₀₇ The y ₀₇ = 0.7 · y ₁₀ when the effective image pickup plane of the electronic imaging device the distance to the farthest point from the center in (imageable plane) (maximum image height) was y _10,
ω _07w is an angle with respect to the optical axis in the object direction corresponding to the image point connecting from the center on the imaging surface at the wide angle end to the position of y ₀₇ ,
fw is the focal length of the entire system of the imaging optical system at the wide-angle end,
It is.

Images