JP4633847B2 - Zoom lens and electronic imaging device using the same - Google Patents

Description

  The present invention relates to a zoom lens and an electronic image pickup apparatus using the same, and more particularly to an electronic image pickup apparatus such as a video camera or a digital camera that is thinned in the depth direction by devising an optical system part such as a zoom lens. Is.

  In recent years, a digital camera (electronic camera) has attracted attention as a next-generation camera that replaces a silver salt 35 mm film (135 format) camera. Furthermore, it has come to have a number of categories in a wide range from a high-function type for business use to a portable popular type.

  In the present invention, focusing on the portable popular type category, it is aimed to provide a technology for realizing a video camera and a digital camera that are thin and easy to use while ensuring high image quality.

  The biggest bottleneck in reducing the depth direction of the camera is the thickness from the most object-side surface to the imaging surface of the optical system, particularly the zoom lens system.

  The mainstream of the recent camera body thinning technology is to employ a so-called collapsible lens barrel that has an optical system that protrudes from the camera body at the time of photographing, but is housed when it is carried. Examples of optical systems that can be effectively thinned by employing a retractable lens barrel include those of Patent Document 1, Patent Document 2, and Patent Document 3. These have, in order from the object side, a first group having a negative refractive power and a second group having a positive refractive power, and both move during zooming. However, if a retractable lens barrel is used, it takes time to start from the lens storage state to the use state, which is not preferable in terms of usability. Further, if the lens group closest to the object is movable, it is not preferable in terms of waterproofing and dustproofing.

Japanese Patent Application Laid-Open No. 11-194274 Japanese Patent Laid-Open No. 11-287953 JP 2000-9997 A

  The present invention has been made in view of such problems of the prior art, and its object is to eliminate the time for starting up the camera (the lens protruding time) as seen in a retractable lens barrel. It is also preferable for waterproofing and dustproofing, and it is easy to bend the optical path (optical axis) of the optical system with a reflective optical element such as a mirror to make the camera extremely thin in the depth direction, with a high zoom ratio and wide angle of view. A zoom lens having a high optical specification performance such as a small F value and a small aberration, and an electronic image pickup apparatus using the zoom lens.

In order to achieve the above object, a zoom lens according to the present invention has a positive refractive power and moves only to the object side when zooming from the wide-angle end to the telephoto end, and the moving lens group B The zoom lens is arranged at the object side, has a negative refractive power, and is fixed at the time of zooming. A third lens group C; and a fourth lens group D having an aspheric surface disposed on the image side of the third lens group C;
The moving lens group B is composed of three lenses of a positive lens, a negative lens, and a positive lens in order from the object side.
The fourth lens group D is fixed at the time of zooming and focusing,
When zooming from the wide-angle end to the telephoto end, the lens unit B and the lens unit C move to the object side at the telephoto end rather than the wide-angle end while changing the relative distance.
The following condition (21) "'is satisfied.
(21) "'0.0 <M ₃ / M ₂ ≦ 0.97637
However, M ₂ and M ₃ are movement amounts at the telephoto end with respect to the wide-angle end when the moving lens unit B and the third lens unit C are focused on the object point at infinity, and the movement toward the image side is positive. To do.

  Below, the reason and effect | action which take the said structure in this invention are demonstrated.

  The zoom lens of the present invention has a positive refracting power and moves only to the object side when zooming from the wide-angle end to the telephoto end, and is disposed closer to the object side than the moving lens group B. The zoom lens has a variable power lens unit A that has negative refractive power and is fixed at the time of zooming.

  In particular, by adopting an optical system having the following structural features, high optical specification performance is ensured even when the first lens group is fixed.

  a. The lens group B is composed of two positive lenses and one negative lens in order from the object side.

  b. The lens group B includes a positive lens, a negative lens, and a positive lens in order from the object side.

  c. The lens group B has a lens group C adjacent to the image side of the lens group B, the lens group B includes one positive lens and one negative lens, and the lens group C includes two positive lenses and one negative lens in order from the object side. Consists of lenses.

d. It has a lens group C adjacent to the image side of the lens group B, the lens group B is one positive lens and one negative lens, and the lens group C is a positive lens, a negative lens, and a positive lens in order from the object side. What is configured.
It is.

  Another lens group may be arranged between the moving lens group B and the zooming fixed lens group A. In order to shorten the overall length, it is more preferable that the moving lens group B and the variable power fixed lens group A are configured with a variable air gap therebetween. In addition, it is more preferable that the fixed lens group A at the time of zooming is positioned closest to the object side in the zoom lens, so that enlargement of the entrance surface of the zoom lens can be suppressed.

  In each of the above zoom lenses, it is preferable that the following conditions are satisfied for the lens groups A and B.

(1) 0.9 <−f _A / √ (f _W · f _T ) <2.0
(2) 1.0 <f _B / √ (f _W · f _T ) <3.0
(3) 0.9 <log γ _B / log γ <10
Where f _A and f _B are the focal lengths of the lens groups A and B, respectively, f _W and f _T are the focal lengths at the wide-angle end and the telephoto end of the entire zoom lens system, and γ and γ _B are respectively
γ = f _T / f _W
γ _B = magnification of lens group B at the telephoto end / magnification of lens group B at the wide-angle end.

  Condition (1) indicates a range of an appropriate focal length of the lens group A. If the upper limit of 2.0 is exceeded, it is difficult to ensure a sufficient zoom ratio, and if the lower limit of 0.9 is exceeded, it is difficult to correct off-axis aberrations such as distortion.

  Condition (2) shows a range of an appropriate focal length of the lens group B. If the upper limit of 3.0 is exceeded, the total length of the optical system becomes long, and if the upper limit of 1.0 is exceeded, correction of spherical aberration and coma becomes difficult.

  Condition (3) defines the zoom ratio of the lens unit B when zooming from the wide-angle end to the telephoto end. If the upper limit of 10 is exceeded, the amount of movement of the lens group B at the time of zooming increases, and if the lower limit of 0.9 is exceeded, a group having a zooming action other than the lens group B is burdened, and the whole As a result, the number of lens components increases.

  In addition, it is better to set one or more or all of the conditions (1) to (3) as follows.

(1) ′ 1.0 <−f _A / √ (f _W · f _T ) <1.8
(2) ′ 1.2 <f _B / √ (f _W · f _T ) <2.7
(3) '1.0 <log γ _B / log γ <9
Furthermore, it is better to set one or more of the conditions (1) to (3) as follows. In particular, it is best to do everything as follows.

(1) "1.1 <-f _A / √ (f _W · f _T ) <1.6
(2) "1.4 <f _B / √ (f _W · f _T ) <2.4
(3) "1.1 <log γ _B / log γ <8
About each of said ad, what was comprised as follows among them is preferable.

  a. A negative lens of the lens group B is cemented with a positive lens adjacent to the object side to form three components.

  b. A negative lens of the lens group B is cemented with any positive lens adjacent to the negative lens to form three components.

  c. A negative lens of the lens group C is cemented with a positive lens adjacent to the object side to form three components.

  d. A negative lens of the lens group C is cemented with any positive lens adjacent to the negative lens to form three components.

  With these joints, the relative decentering sensitivity between the lens elements constituting the lens group including the joints can be reduced. Further, it is preferable that the following condition (4) (conditions regarding aberration correction and decentration sensitivity relaxation) is satisfied for the lens group B of the zoom lens a.

(4) 0.25 <R _22R / R _22F <0.95
Here, R _22F and R _22R are the curvature radii on the optical axis of the most object side surface and the most image side surface of the image side lens component of the lens group B, respectively.

  If the upper limit of 0.95 of condition (4) is exceeded, it is advantageous for correcting spherical aberration, coma aberration, and astigmatism of the entire system aberration, but the effect of alleviating decentration sensitivity by joining is small. When the lower limit of 0.25 is exceeded, correction of spherical aberration, coma aberration, and astigmatism of the total system aberration tends to be difficult.

  It is better to do the following.

(4) '0.30 <R _22R / R _22F <0.90
Furthermore, it is best to do the following.

(4) "0.33 <R _22R / R _22F <0.85
Furthermore, it is preferable to satisfy the conditions (5) and (6) relating to chromatic aberration correction.

(5) -1.0 <L / R _22C <0.8
(6) 14 <ν _22F −ν _22R
Here, R _22C is a radius of curvature on the optical axis of the cemented surface of the image side lens component of the lens group B, and L is a diagonal length (mm) of an effective imaging region of the electronic imaging device to be used. It is assumed that the electronic image sensor is used so that the wide angle end angle of view includes 55 ° or more. ν _22F and ν _22R are Abbe numbers on the d-line basis of the medium of the positive lens and negative lens of the image side lens component of the lens group B, respectively.

  Exceeding the lower limit of -1.0 of condition (5) is advantageous for correction of axial chromatic aberration and chromatic aberration of magnification, but chromatic aberration of spherical aberration is likely to occur. In particular, spherical aberration at the reference wavelength can be corrected well. However, the short wavelength spherical aberration is not preferable because it is in an overcorrected state and causes color blur in the image. Exceeding the upper limit of 0.8 tends to result in insufficient correction of axial chromatic aberration and chromatic aberration of magnification and an undercorrected state of short wavelength spherical aberration.

  If the lower limit of 14 of the condition (6) is exceeded, the axial chromatic aberration is likely to be insufficiently corrected. On the other hand, if an upper limit is given to the condition (6), the material is less expensive. It is preferable that it can be configured.

  In addition, it is better to set one or both of the conditions (5) and (6) as follows.

(5) ′ −0.8 <L / R _22C <0.6
(6) '18 <ν _22F −ν _22R
Furthermore, it is better to set one or both of the conditions (5) and (6) as follows.
In particular, it is best to do both as follows.

(5) "-0.6 <L / R _22C <0.4
(6) ”22 <ν _22F −ν _22R
Since the lens component on the image side of the lens group B is a cemented lens component, a single lens is sufficient as the object-side lens component.

  Furthermore, the following conditions (7) and (8) are preferable. These conditions (7) and (8) may be added as auxiliary conditions for the condition (4).

(7) −1.6 <(R _21F + R _21R ) / (R _21F −R _21R ) <1.2
(8) -1.2 <L / f _2R <0.1
Where R _21F and R _21R are the radius of curvature on the optical axis of the object side lens component of the moving lens group B on the optical axis, L is the diagonal length of the effective imaging area of the electronic image sensor, and f _2R Is the focal length of the image side lens component of the moving lens group B.

  In terms of aberration correction, the shape factor condition (7) in the vicinity of the optical axis of the object-side positive lens component is the upper limit because the divergent light beam enters the lens group B because the lens group A has a negative refractive power. Even if either of the above 1.2 or the lower limit of −1.6 is exceeded, it is difficult to correct spherical aberration even if a plurality of aspheric surfaces are introduced on the object side of the lens group B.

  When the lower limit of −1.2 of condition (8) is exceeded, the exit pupil position approaches the image plane and shading is likely to occur, and the eccentricity sensitivity between the two components in the lens group B tends to increase. If the upper limit of 0.1 is exceeded, it is difficult to ensure a small and high zoom ratio.

  In addition, it is better to set one or both of the conditions (7) and (8) as follows.

(7) ′ − 1.2 <(R _21F + R _21R ) / (R _21F −R _21R ) <0.8
(8) ′ − 1.0 <L / f _2R <0.0
Furthermore, it is better to set one or both of the conditions (7) and (8) as follows. In particular, it is best to do both as follows.

(7) "-0.8 <( _R21F + _R21R ) / ( _{R21F- R21R} ) <0.5
(8) ”−0.9 <L / f _2R <−0.1
Alternatively, as another solution of the zoom lens a, a portion corresponding to the condition (4) may be set as the following condition (9). In this case, as described below, the conditions (10), (11), (12), and (13) are satisfied instead of the previous conditions (5), (6), (7), and (8). It is good.

(9) 0.6 <R _21R / R _21F <1.0
However, R _21F and R _21R are radii of curvature in the vicinity of the optical axis of the object side surface and the image side surface of the object side lens component of the moving lens group B, respectively.

  If the upper limit of 1.0 of condition (9) is exceeded, it is advantageous for correcting spherical aberration, coma aberration, and astigmatism of the entire system aberration, but the effect of reducing the sensitivity of decentration by joining is small. If the lower limit of 0.6 is exceeded, it will be difficult to correct spherical aberration, coma aberration, and astigmatism of the total system aberration.

  It is better to do the following.

(9) '0.65 <R _21R / R _21F <0.9
Furthermore, it is best to do the following.

(9) ”0.7 <R _21R / R _21F <0.8
Furthermore, it is preferable to satisfy the conditions (10) and (11) regarding chromatic aberration correction.

(10) -1.6 <L / R _22C <-0.4
(11) 20 <ν _22F −ν _22R
However, R _22C is a radius of curvature on the optical axis of the cemented surface of the image side lens component of the lens group B, and L is a diagonal length of the effective imaging area of the electronic imaging device to be used. It is assumed that the electronic image sensor is used so that the wide angle end angle of view includes 55 ° or more. ν _22F and ν _22R are Abbe numbers on the d-line basis of the medium of the positive lens and negative lens of the image side lens component of the lens group B, respectively.

  Exceeding the lower limit of -1.6 of condition (10) is advantageous for correction of longitudinal chromatic aberration and lateral chromatic aberration, but chromatic aberration of spherical aberration is likely to occur, and in particular, spherical aberration at the reference wavelength can be corrected well. However, the short wavelength spherical aberration is not preferable because it is in an overcorrected state and causes color blur in the image. Exceeding the upper limit of −0.4 tends to result in insufficient correction of axial chromatic aberration and chromatic aberration of magnification and an undercorrected state of short wavelength spherical aberration.

  If the lower limit of 20 in the condition (11) is exceeded, the axial chromatic aberration tends to be insufficiently corrected. On the other hand, if an upper limit is added to the condition (11), the material is less expensive. It is preferable that it can be configured.

  In addition, it is better to set one or both of the conditions (10) and (11) as follows.

(10) ′ −1.4 <L / R _22C <−0.6
(11) '25 <ν _22F −ν _22R
Furthermore, it is better to set one or both of the conditions (10) and (11) as follows. In particular, it is best to do both as follows.

(10) "-1.2 <L / R _22C <-0.8
(11) ”30 <ν _22F −ν _22R
In the zoom lens a that satisfies the condition (9), it is preferable that the conditions (12) and (13) are satisfied instead of the conditions (7) and (8). Further, it may be added as an auxiliary condition to the condition (9).

(12) −1.5 <(R _22F + R _22R ) / (R _22F −R _22R ) <0.2
(13) 0.05 <L / f _2R <0.5
Where R _22F and R _22R are the most object-side surfaces of the image-side lens components of the lens group B, the radius of curvature on the optical axis of the most image-side surfaces, and L is the diagonal length of the effective imaging region of the electronic image sensor. f _2R is the focal length of the image side lens component of the moving lens unit B.

  Condition (12) is a rule regarding the shape factor of the image side lens component of the lens group B. If the lower limit of −1.5 is exceeded, the air gap between the two lens components of the lens group B can be easily reduced, but it is difficult to correct coma and astigmatism. If the upper limit of 0.2 is exceeded, mechanical interference between the two lens components is likely to occur, and in order to prevent this, the distance between the two is increased, which is not preferable.

  When the lower limit of 0.05 of the condition (13) is exceeded, the exit pupil position tends to cause shading close to the image plane, and the eccentricity sensitivity between the two components in the lens group B tends to increase. If the upper limit of 0.5 is exceeded, it is difficult to ensure a high zoom ratio with a small size.

  In addition, it is better to set one or both of the conditions (12) and (13) as follows.

(12) ′ − 1.2 <(R _22F + R _22R ) / (R _22F −R _22R ) <− 0.2 (13) ′ 0.1 <L / f _2R <0.4
Furthermore, it is better to set one or both of the conditions (12) and (13) as follows. In particular, it is best to do both as follows.

(12) "-1.0 <( _R22F + _R22R ) / ( _{R22F- R22R} ) <-0.6 (13)" 0.15 <L / _f2R <0.3
Although the description has been given of the case of the zoom lens a, the zoom lens c can be realized by replacing the description of the lens group B with the lens group C.

  That is, the following conditional expression (4C) is set instead of conditional expression (4).

(4C) 0.25 <R _32R / R _32F <0.75
However, R _32F and R _32R are the curvature radii on the optical axis of the most object side surface and the most image side surface of the image side lens component of the third lens group C, respectively.

  The same applies to the subordinate conditions (4) ′ and (4) ″.

  Further, the following conditional expressions (5C) and (6C) are set instead of the conditional expressions (5) and (6), respectively.

(5C) -1.0 <L / R _32C <0.6
(6C) 14 <ν _32F −ν _32R
Where R _32C is the radius of curvature of the cemented surface of the image side lens component of the third lens group C on the optical axis, L is the diagonal length of the effective imaging area of the electronic image sensor used, and ν _32F and ν _32R are respectively This is the Abbe number on the d-line basis of the medium of the positive lens and negative lens of the image side lens component of the third lens group C.

  The same applies to the subordinate conditions (5) ', (5) ", (6)', and (6)".

  Further, the following conditional expressions (7C) and (8C) are set instead of the conditional expressions (7) and (8), respectively.

(7C) −1.6 <(R _31F + R _31R ) / (R _31F −R _31R ) <0.4
(8C) −1.2 <L / f _3R <−0.1
Here, R _31F and R _31R are the radius of curvature on the optical axis of the most object side surface and the most image side surface in the object side lens component of the third lens group C, respectively, L is the diagonal length of the effective imaging region of the electronic image sensor, f _3R is the focal length of the image side lens component of the third lens group C.

  The same applies to these subordinate conditions (7) ', (7) ", (8)', and (8)".

  Further, the following conditional expression (9C) is set instead of conditional expression (9).

(9C) 0.6 <R _31R / R _31F <1.0
However, R _31F and R _32R are the radii of curvature on the optical axis of the most object side surface and the most image side surface of the object side lens component of the third lens group C, respectively.

  The same applies to the subordinate conditions (9) ′ and (9) ″.

  Further, the following conditional expressions (10C) and (11C) are set instead of the conditional expressions (10) and (11), respectively.

(10C) -1.6 <L / R _32C <-0.4
(11C) 20 <ν _32F −ν _32R
Where R _32C is the radius of curvature of the cemented surface of the image side lens component of the third lens group C on the optical axis, L is the diagonal length of the effective imaging area of the electronic image sensor used, and ν _32F and ν _32R are respectively This is the Abbe number on the d-line basis of the medium of the positive lens and negative lens of the image side lens component of the third lens group C.

  The same applies to the subordinate conditions (10) ', (10) ", (11)', and (11)".

  Further, the following conditional expressions (12C) and (13C) are set instead of the conditional expressions (12) and (13), respectively.

(12C) −1.5 <(R _32F + R _32R ) / (R _32F −R _32R ) <0.2
(13C) 0.05 <L / f _3R <0.5
Where R _32F and R _32R are the most object side surface and the radius of curvature on the optical axis of the image side lens component of the third lens group C, L is the diagonal length of the effective imaging region of the electronic image sensor, f _3R is the focal length of the image side lens component of the third lens group C.

  The same applies to the subordinate conditions (12) ′, (12) ″, (13) ′, and (13) ″.

  Next, the lens group B of the zoom lens b may satisfy the following conditions (14) to (19).

(14) 0.6 <R _21R / R _21F <1.2
Here, R _21F and R _21R are the radii of curvature on the optical axis of the most object side surface and the most image side surface in the object side lens component of the moving lens group B, respectively.

  If the upper limit of 1.2 of the condition (14) is exceeded, it is advantageous for correcting spherical aberration, coma aberration, and astigmatism of the entire system aberration, but the effect of reducing decentration sensitivity by joining is small. If the lower limit of 0.6 is exceeded, it will be difficult to correct spherical aberration, coma aberration, and astigmatism of the total system aberration.

  It is better to do the following.

(14) '0.7 <R _21R / R _21F <1.1
Furthermore, it is best to do the following.

(14) ”0.8 <R _21R / R _21F <1.0
Furthermore, it is preferable to satisfy the conditions (15) and (16) regarding chromatic aberration correction.

(15) 0.3 <L / R _21C <1.6
(16) 10 <ν _21F −ν _21R
Where R _21C is the radius of curvature on the optical axis of the cemented surface of the object side lens component of the moving lens group B, L is the diagonal length of the effective imaging area of the electronic image sensor, and ν _21F and ν _21R are the moving lens group B, respectively.
The Abbe number on the d-line basis of the medium of the positive lens and the negative lens in the object side lens component. It is assumed that the electronic image sensor is used so that the wide angle end angle of view includes 55 ° or more.

  Exceeding the lower limit of 0.3 of condition (15) is advantageous for correction of longitudinal chromatic aberration and lateral chromatic aberration, but chromatic aberration of spherical aberration is likely to occur, and even if spherical aberration at the reference wavelength can be corrected well. In addition, short wavelength spherical aberration is not preferable because it causes an overcorrected state and causes color blur in an image. Exceeding the upper limit of 1.6 tends to result in insufficient correction of axial chromatic aberration and chromatic aberration of magnification and an undercorrected state of short wavelength spherical aberration.

  If the lower limit of 10 in the condition (16) is exceeded, the axial chromatic aberration tends to be undercorrected. On the other hand, if an upper limit is given to the condition (16), the material is less expensive. It is preferable that it can be configured.

  Note that it is better to set one or both of the conditions (15) and (16) as follows.

(15) '0.35 <L / R _21C <1.5
(16) '15 <ν _21F −ν _21R
Furthermore, it is better to set one or both of the conditions (15) and (16) as follows. In particular, it is best to do both as follows.

(15) "0.4 <L / R _21C <1.4
(16) ”20 <ν _21F −ν _21R
In the zoom lens b that satisfies the condition (14), the conditions (17) and (18) may be added to the condition (14) as auxiliary conditions.

(17) −5.0 <(R _22F + R _22R ) / (R _22F −R _22R ) <0.7
(18) 0.1 <L / f _2R <1.0
Where R _22F and R _22R are the outermost object side surface and the radius of curvature on the optical axis of the image side lens component of the image side lens component of the moving lens group B, L is the diagonal length of the effective imaging region of the electronic image sensor, and f _2R Is the focal length of the image side lens component of the moving lens group B.

  Condition (17) is a rule regarding the shape factor of the image side lens component of the lens group B. If the lower limit of −5.0 is exceeded, the air gap between the two lens components of the lens group B can be easily reduced, but it is difficult to correct coma and astigmatism. If the upper limit of 0.7 is exceeded, mechanical interference between the two lens components is likely to occur, and in order to prevent this, the distance between the two is increased, which is not preferable.

  When the lower limit of 0.1 of the condition (18) is exceeded, the exit pupil position approaches the image plane and shading is likely to occur, and the eccentricity sensitivity between the two components in the lens group B tends to increase. When the upper limit of 1.0 is exceeded, it is difficult to ensure a high zoom ratio with a small size.

  Note that it is better to set one or both of the conditions (17) and (18) as follows.

(17) ′ − 3.5 <(R _22F + R _22R ) / (R _22F −R _22R ) <0.5
(18) '0.2 <L / f _2R <0.8
Furthermore, it is better to set one or both of the conditions (17) and (18) as follows. In particular, it is best to do both as follows.

(17) ”− 0.7 <(R _22F + R _22R ) / (R _22F −R _22R ) <0.3
(18) ”0.25 <L / f _2R <0.6
Although the description has been given of the case of the zoom lens b, the zoom lens d can be realized by replacing the description of the lens group B with the lens group C.

  That is, the following conditional expression (14C) is set instead of conditional expression (14).

(14C) 0.6 <R _31R / R _31F <1.2
Here, R _31F and R _31R are the radii of curvature on the optical axis of the most object side surface and the most image side surface in the object side lens component of the third lens group C, respectively.

  The same applies to the subordinate conditions (14) 'and (14) ".

  Further, the following conditional expressions (15C) and (16C) are set instead of the conditional expressions (15) and (16), respectively.

(15C) 0.3 <L / R _31C <1.6
(16C) 10 <ν _31F −ν _31R
Where R _31C is the radius of curvature on the optical axis of the cemented surface in the object side lens component of the third lens group C, L is the diagonal length of the effective imaging region of the electronic image sensor, and ν _31F and ν _31R are the third The Abbe number with respect to the d-line of the medium of the positive lens and the negative lens in the object side lens component of the lens group C.

  The same applies to the subordinate conditions (15) ', (15) ", (16)', and (16)".

  Further, the following conditional expressions (17C) and (18C) are set instead of the conditional expressions (17) and (18), respectively.

(17C) −5.0 <(R _32F + R _32R ) / (R _32F −R _32R ) <0.7
(18C) 0.1 <L / f _3R <1.0
Where R _22F and R _22R are the most object side surface and the radius of curvature on the optical axis of the image side lens component of the third lens group C, respectively, L is the diagonal length of the effective imaging region of the electronic image sensor, f _3R is the focal length of the image side lens component of the third lens group C.

  The same applies to the subordinate conditions (17) ', (17) ", (18)', and (18)".

  Note that the zoom lenses a and b also have at least one movable group on the image side of the lens group B in order to have both a zooming function and a focal position correction function. It is desirable that the lens group C is adjacent to the lens group B. On the other hand, in order to make the imaging device itself thin, it is preferable to simplify the zoom lens mechanism as much as possible. That is, it is preferable that only two groups are movable at the time of zooming and focusing.

  The conditions described below are common to all zoom lenses a to d.

Focusing is preferably performed when the lens group B is located behind the lens group B, particularly when the lens group C is provided. Furthermore, it is preferable that the on-optical-axis air distance D _FT of the lens unit B to the lens unit C when focusing on an object point at infinity at the telephoto end satisfies the following conditional expression.

(19) 0.1 <D _FT / f _T <1.0
Here, f _T is the focal length of the entire system when focusing on an object point at infinity at the telephoto end.

  If the upper limit of 1.0 of the condition (19) is exceeded, it will be difficult to secure the zoom ratio, and if the lower limit of 0.1 is exceeded, the focusable distance range cannot be taken sufficiently.

  It is better to do the following.

(19) '0.2 <D _FT / f _T <0.8
Furthermore, it is best to do the following.

(19) ”0.3 <D _FT / f _T <0.6
By the way, the third lens group C should have a positive refractive power in order to reduce the power burden on the lens group B and facilitate aberration correction. In this case, the feeding direction when focusing on an object at a closer distance is on the object side.

(20) −0.4 <L / f _C <0.8
Here, f _C is the focal length of the third lens group C, and L is the diagonal length of the effective imaging area of the electronic imaging device.

  When the lower limit of −0.4 of the condition (20) is exceeded, the amount of extension at the time of focusing becomes too large, and the lens group B tends to interfere, and the aberration fluctuation at the time of focusing tends to increase. If the upper limit of 0.8 is exceeded, the power of the lens group B is weakened, so that the amount of movement during zooming increases or the zooming ratio tends to decrease.

  It is better to do the following.

(20) '-0.3 <L / f _C <0.6
Furthermore, it is best to do the following.

(20) "-0.2 <L / f _C <0.4
Further, when zooming from the wide-angle end to the telephoto end, it is preferable to use a zoom format in which the lens unit B and the lens unit C move while changing the relative distance. This method can earn a high zoom ratio while performing focus position correction by zooming using space efficiently. In that case, the ratio of the movement amounts M ₂ and M ₃ of the lens unit B and the lens unit C when zooming from the wide-angle end to the telephoto end at the time of focusing on infinity may be set as the following condition (21). .

(21) 0.0 <M ₃ / M ₂ <1.6
However, M ₂ and M ₃ are movement amounts at the telephoto end with respect to the wide-angle end when the moving lens unit B and the third lens unit C are focused on the object point at infinity, and the movement toward the image side is positive. To do.

  If the upper limit of 1.6 of the condition (21) is exceeded, the zoom ratio and the focusable distance range cannot be taken sufficiently. If the lower limit of 0.0 is exceeded, it is also difficult to secure a zoom ratio.

  It is better to do the following.

(21) '0.2 <M ₃ / M ₂ <1.4
Furthermore, it is best to do the following.

(21) "0.4 <M ₃ / M ₂ <1.2
For the purpose of improving aberration correction and exit side telecentricity, it is preferable to dispose the lens group D closer to the image side than the lens group C. Furthermore, it is preferable that the following condition (22) is satisfied.

(22) 0.0 <L / f _D <0.7
Here, f _D is the focal length of the fourth lens group D, and L is the diagonal length of the effective imaging area of the electronic imaging device.

  If the lower limit of 0.0 in condition (22) is exceeded, the exit pupil position at the wide-angle end tends to approach the image plane, and if the upper limit of 0.7 is exceeded, the exit pupil position changes during zooming. The amount becomes too large and both are likely to cause shading.

  It is better to do the following.

(22) ′ 0.1 <L / f _D <0.5
Furthermore, it is best to do the following.

(22) "0.2 <L / f _D <0.35
In addition, it is effective to introduce an aspherical surface into the lens group D to correct aberrations that cannot be corrected by the lens group A and the lens group B. In particular, it is very effective for correcting off-axis aberrations such as distortion, astigmatism, and coma. Since this lens group D cancels a considerable amount of aberration occurring on the object side, the aberration balance is lost when the lens group D is moved by focusing or the like. Therefore, it is desirable that the lens group D is fixed at the time of focusing.

  In order to make the lens incident surface face the object side and reduce the depth, it is preferable to perform optical path bending at a position as close as possible to the object side of the photographing optical system and at a position where the light beam height is low. Further, from the viewpoint of abolishing the collapsible lens frame and waterproofing, it is preferable that the moving group is located on the image side with respect to the folding position.

  In order to make the folding space as small as possible, considering that the height of all the rays that contribute to the image formation in the vicinity of the bent portion should be low, it is possible to move from the most object side lens group where the bent portion exists at the time of zooming. It is desirable that the combined focal length of the subsystems up to immediately before the correct group is negative.

  Therefore, bending the optical path to make the depth direction thin is easy to implement in a zoom lens having a negative refractive power and having a fixed lens group A located on the most object side as in the present invention. In particular, it is preferable to insert a reflective optical element into the lens group A and bend the optical path. In this case, the lens group A is preferably composed of a sub group A1 having a negative meniscus lens having a convex surface on the object side, a reflecting optical element for bending the optical path, and a sub group A2 including at least a positive lens.

  In this case, in any type, the air-converted length d as measured along the optical axis from the most image-side surface top of the first lens group sub-group A1 to the most object-side surface top of the sub-group A2. The air equivalent length d from the refractive surface having the refractive power immediately before the reflecting surface of the reflecting optical element in the lens group A fixed at the time of zooming to the refractive surface having the refractive power immediately after the reflecting surface is set as follows. Is good.

(23) 0.8 <d / L <2.0
If the upper limit of 2.0 of this condition (23) is exceeded, the optical element on the object side including the prism tends to be large, which is disadvantageous in terms of aberration correction, and the combined magnification of the groups after the lens group B is low. Therefore, the amount of movement of the lens group B increases or it becomes difficult to ensure a high zoom ratio. If the lower limit of 0.8 is exceeded, the light beam contributing to the image formation at the periphery of the image does not reach the image plane satisfactorily, or ghosts are likely to occur.

  In addition, when the angle of view in the direction of bending the optical path is 25 ° ± 3 °, and when it is about 19 ° ± 3 °, the following ranges are preferable.

(23-1) 0.9 <d / L <1.7
(23-2) 1.0 <d / L <1.8
Furthermore, the conditions (23-1) and (23-2) are best as follows.

(23-1) '1.0 <d / L <1.5
(23-2) '1.2 <d / L <1.7
The reflective optical element is composed of a prism having a high refractive power, which is advantageous in terms of downsizing and aberration correction of the object-side optical element including the prism.

(24) 1.5 <n _pri
Here, n _pri is the refractive index of the medium with respect to the d-line of the prism.

  If the lower limit of 1.5 of the condition (24) is exceeded, the optical element on the object side including the prism tends to be large, which is disadvantageous in terms of aberration correction, and the combined magnification of the groups after the lens group B becomes low. The amount of movement of the lens group B increases or it becomes difficult to ensure a high zoom ratio. When determining the upper limit value, it is desirable that the refractive index does not exceed 1.90. If the upper limit is also exceeded, a ghost due to total reflection tends to occur. Furthermore, the upper limit value is more preferably 1.87, and even more preferably 1.84.

  It is better to do the following.

(24) '1.6 <n _pri
Furthermore, it is best to do the following.

(24) ”1.7 <n _pri
The sub group A2 of the lens group A is composed of two negative lenses and a positive lens in order from the object side in order to correct off-axis aberrations such as chromatic aberration and distortion, and satisfies the following conditions: Good.

(25) −0.5 <L / f ₁₂ <0
Here, L is the diagonal length of the effective image pickup area of the electronic image pickup device, and f ₁₂ is the focal length of the image side subgroup A2 of the fixed lens group A during zooming.

  If the upper limit of 0 in the condition (25) is exceeded, the combined magnification of the groups after the lens group B will be low, the amount of movement of the lens group B will increase, or it will be difficult to ensure a high zoom ratio. If it exceeds .5, the object-side optical element including the prism tends to be large, which is disadvantageous in terms of aberration correction.

  It is better to do the following.

(25) ′ −0.4 <L / f ₁₂ <−0.05
Furthermore, it is best to do the following.

(25) "-0.3 <L / f 12 <-0.1
In any type, the reflecting surface may be configured other than a plane in order to make the paraxial refractive power arrangement appropriate. In addition, a control system that can freely change the shape of the reflective surface is provided, so that it can be used to correct focus position and aberration fluctuations that occur during zooming, focus, and zoom. More preferably, it is a controllable variable shape mirror. Apart from this, a plano-concave lens may be cemented to the prism plane portion as a reflective optical element, or the effective light beam passage or reflection surface of the prism may be formed of a curved surface. In view of the balance between the level of distortion correction and the target size of the electronic imaging device, a positive lens with the weakest power may be added to the object side. In that case, the subgroup A2 of the lens group A may not be provided. The sub group A1 of the lens group A is fixed at the time of zooming, but the sub group A2 may be movable because it is relatively easy to move. In that case, it is preferable to move while drawing a convex locus on the image side during zooming.

  The reflective optical element is not necessarily arranged between the plurality of lenses in the fixed lens group A. The reflective optical element is arranged on the most object side or the most image side of the fixed lens group A. It does n’t matter.

  When any of the following structural limitations is added, a bent zoom lens having a higher specification performance and a simple configuration can be obtained, which contributes to further thinning of the imaging device.

  ○ Only one negative lens convex in the sub-group A1 object side of the lens group A is used.

With this arrangement, the depth of the optical system can be minimized while maintaining the angle of view. In that case, it is meaningless if the power of the negative lens is not a certain level,
(26) 0 <f ₁₁ / f ₁₂ <1.6
And Here, f ₁₁ and f ₁₂ are the focal lengths of the subgroups A1 and A2 of the lens group A, respectively.

  Even if either the upper limit of 1.6 or the lower limit of 0 of the condition (26) is exceeded, the bending optical element tends to be large.

  It is better to do the following.

(26) ′ 0.1 <f ₁₁ / f ₁₂ <1.5
Furthermore, it is best to do the following.

(26) ”0.2 <f ₁₁ / f ₁₂ <1.4
In order to reduce costs by reducing the number of components, one of the lens group B and the lens group C may be a single lens, and the other may include at least a negative lens. The lens group B and the lens group C of the present invention move in the same direction while slightly changing the relative distance at the time of zooming. In addition, there is an advantage that the chromatic aberration can be corrected mutually by the lens group B and the lens group C. Therefore, it is not necessary to complete correction of chromatic aberration of each group, and the above-described configuration is possible.

  In order to keep the change in the relative distance between the lens group B and the lens group C as small as possible, it is preferable that the magnification of the synthesis system after the lens group B is changed near -1. However, a lower absolute value of magnification is advantageous for aberration correction. Therefore, the following conditions should be satisfied at the telephoto end.

(27) 0.8 <−β _Rt <2.1
Here, β _Rt is the combined magnification after the moving lens group B at the telephoto end when focusing on an object point at infinity.

If the upper limit of 2.1 or the lower limit of 0.8 of the condition (27) is exceeded, the amount of change in the relative distance between the lens group B and the lens group C becomes large.

  It is better to do the following.

(27) ′ 0.9 <−β _Rt <1.9
Furthermore, it is best to do the following.

(27) "1.0 <-β _Rt <1.7
In the above, another lens group may be disposed between the third lens group C and the fourth lens group D. The third lens group C and the fourth lens group D are more preferable because they are arranged with a variable air gap therebetween, which is advantageous for downsizing.

  In the zoom lens described above, if the reflecting optical element for bending the optical path is a prism, the entrance pupil position can be easily made shallow, which is advantageous for downsizing the lens group A. Further, by providing a curvature on at least one of the transmission surfaces of the prism, that is, by allowing the prism to have a refractive power, the number of lens elements can be reduced, contributing to downsizing and cost reduction. In particular, in order to reduce the depth direction, the prism is preferably disposed closest to the object side, and in this case, the incident surface of the prism is preferably directed concave toward the object side. As a result, the negative meniscus lens on the object side can be omitted as compared with a prism that is necessary in the case of a flat prism, and the depth direction can be made thinner. However, when such a configuration is adopted, correction of off-axis aberrations such as distortion is disadvantageous, so that correction is possible by introducing an aspherical surface. In addition, when an aspherical surface is introduced into the prism incident surface, it is difficult to ensure the accuracy of decentering with respect to the exit surface.

  In the end, the lens group A is composed of a prism A1 for bending an optical path having a transmission surface (incident surface) with a concave surface facing the object side, and a subgroup A2 including at least a positive lens. It will be the best for conversion.

  In this configuration, in particular, when the configuration of the lens group B and the lens group C is the b type (zoom lens b), the manner of generation of coma, astigmatism, and distortion changes, so the following conditions ( 3) to (8), (21), (23), (26) should be in the numerical range (corresponding to the above conditions (3) to (8), (21), (23), (26)) Also, corresponding to those more limited conditions ((3) ′, (3) ″, etc.).)

(3) 2.0 <log γ _B / log γ <10
(3) '2.2 <log γ _B / log γ <9
(3) ”2.4 <log γ _B / log γ <8
(4) 0.45 <R _22R / R _22F <0.95
(4) '0.50 <R _22R / R _22F <0.90
(4) "0.55 <R _22R / R _22F <0.85
(5) -0.8 <L / R _22C <0.8
(5) ′ −0.6 <L / R _22C <0.6
(5) "-0.4 <L / R _22C <0.4
(6) 25 <ν _22F −ν _22R
(6) '30 <ν _22F −ν _22R
(6) ”35 <ν _22F −ν _22R
(7) −1.2 <(R _21F + R _21R ) / (R _21F −R _21R ) <1.2
(7) ′ − 0.8 <(R _21F + R _21R ) / (R _21F −R _21R ) <0.8
(7) ”− 0.5 <(R _21F + R _21R ) / (R _21F −R _21R ) <0.5
(8) -1.2 <L / f _2R <0.1
(8) ′ − 1.0 <L / f _2R <0.0
(8) ”−0.9 <L / f _2R <−0.1
(21) 0.4 <M ₃ / M ₂ <1.6
(21) '0.5 <M ₃ / M ₂ <1.4
(21) ”0.6 <M ₃ / M ₂ <1.2
(23) 0.8 <d / L <1.8
(23-1) 0.9 <d / L <1.5
(23-2) 1.0 <d / L <1.6
(23-1) ′ 1.0 <d / L <1.3
(23-2) '1.2 <d / L <1.5
(26) 0.5 <f ₁₁ / f ₁₂ <1.6
(26) '0.6 <f ₁₁ / f ₁₂ <1.5
(26) ”0.7 <f ₁₁ / f ₁₂ <1.4
In addition, the conditions (3) to (8), (21) except for the case where the configuration of the lens group B and the lens group C is the b type and the prism incident surface of the lens group A is concave on the object side. ), (23), and (26), and the following ranges may be set corresponding to the more limited conditions ((3) ′, (3) ″, etc.).

(3) 0.9 <log γ _B / log γ <4.5
(3) '1.0 <log γ _B / log γ <4.0
(3) "1.1 <log γ _B / log γ <3.8
(4) 0.25 <R _22R / R _22F <0.75
(4) '0.30 <R _22R / R _22F <0.65
(4) "0.33 <R _22R / R _22F <0.55
(5) -1.0 <L / R _22C <0.6
(5) ′ −0.8 <L / R _22C <0.4
(5) "-0.6 <L / R _22C <0.2
(6) 14 <ν _22F −ν _22R
(6) '18 <ν _22F −ν _22R
(6) ”22 <ν _22F −ν _22R
(7) −1.6 <(R _21F + R _21R ) / (R _21F −R _21R ) <0.4
(7) ′ − 1.2 <(R _21F + R _21R ) / (R _21F −R _21R ) <0.0
(7) "-0.8 <( _R21F + _R21R ) / ( _{R21F- R21R} ) <-0.4 (8) -1.2 <L / _f2R <-0.1
(8) ′ −1.0 <L / f _2R <−0.2
(8) ”−0.9 <L / f _2R <−0.3
(21) 0.0 <M ₃ / M ₂ <1.0
(21) '0.2 <M ₃ / M ₂ <0.9
(21) "0.4 <M ₃ / M ₂ <0.8
(23) 1.0 <d / L <2.0
(23-1) 1.1 <d / L <1.7
(23-2) 1.2 <d / L <1.8
(23-1) '1.2 <d / L <1.5
(23-2) ′ 1.4 <d / L <1.7
(26) 0 <f ₁₁ / f ₁₂ <1.1
(26) ′ 0.1 <f ₁₁ / f ₁₂ <1.0
(26) ”0.2 <f ₁₁ / f ₁₂ <0.9
Further, the zoom lens of the present invention is composed of a variable lens unit A, a moving lens unit B, a third lens unit C, and a fourth lens unit D in order from the object side, A small four-group zoom lens can be configured.

  As described above, a means for improving the imaging performance while reducing the retractable thickness of the zoom lens unit has been provided.

Next, mention is made of thinning filters. In an electronic imaging device, an infrared absorption filter having a certain thickness is usually inserted closer to the object side than the imaging device so that infrared light does not enter the imaging surface. Consider replacing this with a thin coating. Naturally, it will be thinner, but it has a side effect. A near-infrared sharp cut coat with a transmittance (τ ₆₀₀ ) at a wavelength of 600 nm of 80% or more and a transmittance (τ ₇₀₀ ) at ₇₀₀ nm of 8% or less on the object side of the image sensor behind the zoom lens system When introduced, the transmittance in the near infrared region of 700 nm or more is lower than that of the absorption type, and the transmittance on the red side is relatively high, which is a disadvantage of a solid-state imaging device such as a CCD having a complementary color mosaic filter. The magenta tendency on the side is alleviated by gain adjustment, and color reproduction similar to that of a solid-state imaging device such as a CCD having a primary color filter can be obtained. Further, not only the primary color complementary color but also the color reproduction of those having a strong reflectance in the near infrared region such as plants and human skin.

That is,
(28) τ ₆₀₀ / τ ₅₅₀ ≧ 0.8
(29) τ ₇₀₀ / τ ₅₅₀ ≦ 0.08
It is desirable to satisfy. However, (tau) ₅₅₀ is the transmittance | permeability in wavelength 550nm.

  Note that it is better to set one or both of the conditions (28) and (29) as follows.

(28) 'τ ₆₀₀ / τ ₅₅₀ ≧ 0.85
(29) 'τ ₇₀₀ / τ ₅₅₀ ≦ 0.05
Further, it is further preferable that either or both of the conditions (28) and (29) are as follows. In particular, it is best to do both as follows.

(28) ”τ ₆₀₀ / τ ₅₅₀ ≧ 0.9
(29) ”τ ₇₀₀ / τ ₅₅₀ ≦ 0.03
Another drawback of a solid-state imaging device such as a CCD is that the sensitivity to the near-ultraviolet wavelength of 550 nm is considerably higher than that of the human eye. This also highlights the color blur at the edge of the image due to chromatic aberration in the near ultraviolet region. In particular, it is fatal to downsize the optical system. Therefore, the ratio of transmittance (τ ₄₀₀ ) at a wavelength of 400 nm to that at 550 nm (τ ₅₅₀ ) is less than 0.08, and the ratio of the transmittance at ₄₄₀ nm (τ ₄₄₀ ) to that at 550 nm (τ ₅₅₀ ). Inserting an absorber or reflector that exceeds 0.4 in the optical path will not lose the wavelength range required for color reproduction (while maintaining good color reproduction), and will significantly reduce noise such as color bleeding. Is done.

That is,
(30) τ ₄₀₀ / τ ₅₅₀ ≦ 0.08
(31) τ ₄₄₀ / τ ₅₅₀ ≧ 0.4
It is desirable to satisfy.

  Note that it is better to set one or both of the conditions (30) and (31) as follows.

(30) 'τ ₄₀₀ / τ ₅₅₀ ≦ 0.06
(31) 'τ ₄₄₀ / τ ₅₅₀ ≧ 0.5
Furthermore, it is better to set one or both of the conditions (30) and (31) as follows. In particular, it is best to do both as follows.

(30) ”τ ₄₀₀ / τ ₅₅₀ ≦ 0.04
(31) ”τ ₄₄₀ / τ ₅₅₀ ≧ 0.6
Note that these filters are preferably installed between the imaging optical system and the image sensor.

  On the other hand, in the case of a complementary color filter, because of its high transmitted light energy, it is substantially more sensitive than a CCD with a primary color filter and is advantageous in terms of resolution. It is.

In order to make the optical system short and thin, it is preferable to make the other low-pass optical filter as thin as possible. In general, the optical low-pass filter uses the birefringence action of a uniaxial crystal such as quartz, but the angle formed by the crystal axis with respect to the optical axis of the zoom lens is in the range of 35 ° to 55 °. In addition, when a plurality of or single crystal optical low-pass filters having different directions when each crystal axis is projected onto the image plane are included, the thickness t of the filter having the largest thickness along the optical axis of the zoom lens is included. _LPF (mm) should satisfy the following conditions.

(32) 0.08 <t _LPF /a<0.16 (when a <4 μm)
0.075 <t _LPF /a<0.15 (when a <3 μm)
Where t _LPF (mm) is the thickness of the optical low-pass filter having the largest thickness along the optical axis of the zoom lens and having one crystal axis in the range of 35 ° to 55 °, and a is the thickness of the electronic image sensor. The horizontal pixel pitch (unit: μm).

  The thickest optical low-pass filter composed of one or a plurality of filters is set so that its thickness is theoretically zero at the Nyquist limit frequency, and is approximately a / 5.88 ( mm). If it is thicker than this, it is effective in preventing false signals such as moire fringes, but the resolution of the electronic image pickup device cannot be sufficiently exerted, and if it is reduced, false signals such as moire fringes cannot be sufficiently removed. However, false signals such as moiré fringes are also closely related to the imaging performance of photographic lenses such as zoom lenses, and when the imaging performance is high, false signals such as moiré fringes are likely to occur. It is better to set a little thicker in the opposite case.

  On the other hand, as the pixel pitch decreases, the contrast of frequency components that exceed the Nyquist limit decreases due to the diffraction effect of the imaging lens system, so that the generation of false signals such as moire fringes is reduced. Therefore, it is preferable that the thickness is made several percent to several tens of percent less than a / 5.88 (mm) because the contrast at a spatial frequency below the frequency corresponding to the Nyquist limit is improved.

  It is better to do the following.

(32) ′ 0.075 <t _LPF /a<0.15 (when a <4 μm)
0.07 <t _LPF /a<0.14 (when a <3 μm)
Furthermore, it is best to do the following.

(32) "0.07 <t _LPF /a<0.14 (when a <4 μm)
0.065 <t _LPF /a<0.13 (when a <3 μm)
In addition, when a <4 μm, the optical low-pass filter is difficult to process if it is too thin, so it is not too thin, that is, even if the upper limit of the conditions (32), (32) ′, (32) ″ is exceeded, There is another way to increase the spatial frequency (cutoff frequency) at which the contrast becomes zero, in the range where the angle formed by the optical axis of the optical low-pass filter with respect to the optical axis of the zoom lens is in the range of 15 ° to 35 °. Alternatively, it may be set to 55 ° to 75 °, or the optical low-pass filter may be omitted depending on the case.In this angle range, the separation amount of incident light into ordinary rays and extraordinary rays is around 45 °. When the angle is 0 ° or 90 °, separation is not achieved (however, in the case of 90 °, there is a speed difference between the two and a phase difference occurs). The principle of the λ / 4 plate).

  Also, as described above, when the pixel pitch is reduced, the imaging performance at a high spatial frequency corresponding to the influence of diffraction is deteriorated, so that it is difficult to increase the F number. Therefore, the type of aperture stop used in the camera may be only two types, that is, a large aperture that is largely deteriorated due to geometric aberration and an aperture value near the diffraction limit. In that case, the optical low-pass filter described above is not necessary.

  Especially when the pixel pitch is small and the imaging performance at the time of opening is the best, as a means of regulating the incident light beam size on the imaging surface, the inner diameter is variable or a method of replacing with a different inner diameter is not used. An aperture stop having a fixed inner diameter may be used. In that case, at least one of the lens surfaces adjacent to the aperture stop has a convex surface directed toward the aperture stop, and if any of the adjacent lens surfaces penetrates the aperture stop inner diameter portion, the aperture is wasted. There is no space, which contributes to shortening the overall length of the optical system. The aperture stop is an optical element having a transmittance of 90% or less (preferably, both the entrance surface and the exit surface should be flat) in any space including the optical axis that is separated by one or more lens surfaces. Or a means for replacing with another optical element having a different transmittance.

  Alternatively, a plurality of apertures having a fixed aperture size are provided, and one of the apertures is in any optical path between the most image side lens surface of the first group and the most object side lens surface of the third group. An electronic imaging device that can be inserted and exchanged with other devices to adjust the illuminance of the image plane, and the transmittance for 550 nm is included in some of the plurality of apertures. It is preferable to adjust the amount of light so as to have a medium that is different and less than 80%. Alternatively, when adjustment is performed so that the amount of light corresponds to the F value such that a (μm) / F number <0.4, the medium having different transmittances for 550 nm and less than 80% in the aperture An electronic imaging device having For example, if the medium is not within the above range from the open value, or a dummy medium with a transmittance of 550 nm or more is set to 91% or more, and the aperture diameter is within the range, the aperture stop diameter is reduced to such an extent that the influence of diffraction occurs. It is better to adjust the amount of light with something like an ND filter.

  Also, it is possible to arrange the plurality of apertures so that their diameters are reduced in inverse proportion to the F value, and to place optical low-pass filters having different frequency characteristics in the apertures instead of the ND filters. Good. Since diffraction degradation increases as the aperture is narrowed down, it is better to set the frequency characteristics of the optical filter higher as the aperture diameter decreases.

  If F> a is satisfied in the relationship between the open F value at the wide-angle end and the pixel pitch a μm to be used, the optical low-pass filter may not be provided. That is, all the media on the optical path between the zoom lens system and the electronic image sensor may be air or an amorphous medium. This is because there is almost no frequency component that can cause aliasing distortion due to degradation of imaging characteristics due to diffraction and geometric aberration.

  It should be noted that the above limitations on the conditional expressions can naturally be applied only to the upper limit values or the lower limit values. In addition, values corresponding to these conditional expressions in each embodiment described later can be changed up to the upper limit or the lower limit of each conditional expression.

According to the present invention, a high zoom ratio, wide angle of view, While ensuring high optical specifications such as small F value and low aberration, there is no camera start-up time (lens protruding time) as seen in a retractable lens barrel, and it is waterproof and dustproof. It is also possible to provide a camera that is preferable and has a very thin depth direction.

FIG. 2 is a lens cross-sectional view at the wide-angle end (a), the intermediate state (b), and the telephoto end (c) when focusing on an object point at infinity according to the first exemplary embodiment of the zoom lens of the present invention. FIG. 6 is a lens cross-sectional view similar to FIG. 1 of a zoom lens according to Embodiment 2. FIG. 6 is a lens cross-sectional view similar to FIG. 1 of a zoom lens according to Example 3. FIG. 6 is a lens cross-sectional view similar to FIG. 1 illustrating a zoom lens according to a fourth exemplary embodiment. FIG. 6 is a lens cross-sectional view similar to FIG. 1 illustrating a zoom lens according to a fifth exemplary embodiment. FIG. 6 is a lens cross-sectional view similar to FIG. 1 illustrating a zoom lens according to Example 6; FIG. 10 is a lens cross-sectional view similar to FIG. 1 illustrating a zoom lens according to a seventh embodiment. FIG. 10 is a lens cross-sectional view similar to FIG. 1 illustrating a zoom lens according to an eighth embodiment. FIG. 10 is a lens cross-sectional view similar to FIG. 1 illustrating a zoom lens according to Example 9; FIG. 12 is a lens cross-sectional view similar to FIG. 1 illustrating a zoom lens according to Example 10; FIG. 12 is a lens cross-sectional view similar to FIG. 1 illustrating a zoom lens according to Example 11; FIG. 12 is a lens cross-sectional view similar to FIG. 1 illustrating a zoom lens according to a twelfth embodiment. FIG. 14 is a lens cross-sectional view similar to FIG. 1 illustrating a zoom lens according to Example 13; FIG. 3 is an optical path diagram when the zoom lens of Example 1 is bent at the time of focusing on an object point at infinity at the wide angle end. FIG. 6 is an aberration diagram for Example 1 upon focusing on an object point at infinity. FIG. 6 is an aberration diagram for Example 2 upon focusing on an object point at infinity. FIG. 10 is an aberration diagram for Example 3 upon focusing on an object point at infinity. FIG. 10 is an aberration diagram for Example 4 upon focusing on an object point at infinity. It is a figure for demonstrating the diagonal length of the effective imaging surface at the time of imaging | photography with an electronic image sensor. It is a figure which shows the transmittance | permeability characteristic of an example of a near-infrared sharp cut coat. It is a figure which shows the transmittance | permeability characteristic of an example of the color filter provided in the emission surface side of a low-pass filter. It is a figure which shows the color filter arrangement | positioning of a complementary color mosaic filter. It is a figure which shows an example of the wavelength characteristic of a complementary color mosaic filter. It is a perspective view which shows the detail of an example of the part of the aperture stop of each Example. It is a figure which shows the detail of another example of the part of the aperture stop of each Example. It is a front perspective view which shows the external appearance of the digital camera incorporating the optical path bending zoom optical system by this invention. FIG. 27 is a rear perspective view of the digital camera of FIG. 26. It is sectional drawing of the digital camera of FIG. It is the front perspective view which opened the cover of the personal computer incorporating the optical path bending zoom optical system by this invention as an objective optical system. It is sectional drawing of the imaging optical system of a personal computer. It is a side view of the state of FIG. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view, a side view, and a sectional view of a photographing optical system of a mobile phone incorporating an optical path bending zoom optical system according to the present invention as an objective optical system.

  Examples 1 to 13 of the zoom lens according to the present invention will be described below. Examples 1, 2, 3, 9, and 13 are reference examples. FIGS. 1 to 13 show lens cross sections at the wide-angle end (a), the intermediate state (b), and the telephoto end (c) when focusing on an object point at infinity in Examples 1 to 13, respectively. 1 to 12, the first lens group is G1, the diaphragm is S, the second lens group is G2, the third lens group is G3, the fourth lens group is G4, the optical low-pass filter is LF, and an electronic image sensor. A CCD cover glass is indicated by CG, and an image plane of the CCD is indicated by I. Further, a parallel plate in which the optical path bending prism in G1 in the first lens group is developed is indicated by P. In FIG. 13, the 1-1 lens group is G1-1, the 1-2 lens group is G1-2, the optical path bending prism is P, the second lens group is G2, the third lens group is G3, and the fourth lens group. The lens group is indicated by G4, the near-infrared cut coat surface is indicated by IC, the optical low-pass filter is indicated by LF, the cover glass of the CCD, which is an electronic image pickup device, is indicated by CG, and the image surface of the CCD is indicated by I. The near-infrared cut coat surface IC, the optical low-pass filter LF, and the cover glass CG are fixedly disposed between the final group G4 and the image surface I. Regarding these embodiments, the maximum thickness of the optical low-pass filter LF will be described later. As for the near-infrared sharp cut coat, for example, the optical low-pass filter LF may be directly coated, or an infrared cut absorption filter may be disposed separately, or the incident surface of the transparent flat plate may be disposed. A near infrared sharp cut coat may be used.

  As a representative example, the optical path bending prism P is configured as a reflecting prism that bends the optical path by 90 °, as shown in FIG. 14, for example, as shown in FIG. The Note that the aspect ratio of the effective imaging area in Examples 1 to 13 is 3: 4, and the bending direction is the horizontal direction.

  As shown in FIG. 1, the zoom lens of Example 1 includes a first lens group G1 including a negative meniscus lens convex toward the object side, an optical path bending prism P, a biconcave negative lens, and a biconvex positive lens. Aperture stop S, a biconvex positive lens, a second lens group G2 composed of a cemented lens of a biconvex positive lens and a biconcave negative lens, a third lens group G3 composed of one biconvex positive lens, and a biconvex positive lens 1 The fourth lens group G4 is composed of a single lens. When zooming from the wide-angle end to the telephoto end, the first lens group G1 and the fourth lens group G4 are fixed, and the second lens group G2 together with the aperture stop S is on the object side. The third lens group G3 moves to the object side while once widening the distance from the second lens group G2 and then shrinking it. In order to focus on a subject at a short distance, the third lens group G3 is extended to the object side.

  The aspherical surface is used for three surfaces, that is, the image surface side surface of the biconcave negative lens of the first lens group G1, the most object side surface of the second lens group G2, and the image surface side surface of the fourth lens group G4. ing.

  As shown in FIG. 2, the zoom lens of Embodiment 2 includes a negative meniscus lens convex on the object side, an optical path bending prism P, a negative meniscus lens convex on the object side, and a positive meniscus lens convex on the object side. A first lens group G1, an aperture stop S, a second lens group G2 composed of a cemented lens of a negative meniscus lens convex to the object side and a biconvex positive lens, a positive meniscus lens convex to the object side, and convex to the object side It consists of a cemented lens of a negative meniscus lens, a third lens group G3 consisting of a positive meniscus lens convex on the object side, and a fourth lens group G4 consisting of a single positive meniscus lens convex on the image side, and telephoto from the wide-angle end. When zooming to the end, the first lens group G1 and the fourth lens group G4 are fixed, the second lens group G2 moves to the object side together with the aperture stop S, and the third lens group G3 is moved to the second lens group G2. Wide distance between While moving toward the object side. In order to focus on a subject at a short distance, the third lens group G3 is extended to the object side.

  The aspherical surfaces are the image surface side surface of the negative meniscus lens immediately after the optical path bending prism P of the first lens group G1, the most object side surface of the third lens group G3, and the image surface side surface of the fourth lens group G4. Are used on the three sides.

As shown in FIG. 3, the zoom lens of Example 3 includes a negative meniscus lens convex on the object side, an optical path bending prism P, a negative meniscus lens convex on the object side, and a positive meniscus lens convex on the object side. A first lens group G1, an aperture stop S, a second lens group G2 composed of a cemented lens of a negative meniscus lens convex to the object side and a biconvex positive lens, a meniscus lens convex to the object side, and a biconvex positive lens. When zooming from the wide angle end to the telephoto end, the third lens group G3 is composed of a cemented lens of a negative meniscus lens that is convex on the image side, and the fourth lens group G4 is composed of one biconvex positive lens. The first lens group G1 and the fourth lens group G4 are fixed, the second lens group G2 moves to the object side together with the aperture stop S, and the third lens group G3 temporarily widens the distance between the second lens group G2 and then shrinks it. Move to the object side In order to focus on a subject at a short distance, the third lens group G3 is extended to the object side.

  The aspherical surfaces are the image surface side surface of the negative meniscus lens immediately after the optical path bending prism P of the first lens group G1, the most object side surface of the third lens group G3, and the image surface side surface of the fourth lens group G4. Are used on the three sides.

  As shown in FIG. 4, the zoom lens of Example 4 includes a negative meniscus lens convex on the object side, an optical path bending prism P, a negative meniscus lens convex on the object side, and a positive meniscus lens convex on the object side. A first lens group G1, an aperture stop S, a cemented lens of a positive meniscus lens convex on the object side and a negative meniscus lens convex on the object side, and a second lens group G2 consisting of a biconvex positive lens, biconvex positive The third lens group G3 includes a cemented lens of a lens and a biconcave negative lens, and the fourth lens group G4 includes one biconvex positive lens. When zooming from the wide-angle end to the telephoto end, the first lens group G1 The fourth lens group G4 is fixed, the second lens group G2 moves to the object side together with the aperture stop S, and the third lens group G3 moves to the object side while temporarily reducing the distance between the second lens group G2 and then reducing the distance. To do. In order to focus on a subject at a short distance, the third lens group G3 is extended to the object side.

  The aspherical surfaces are the image side surface of the negative meniscus lens immediately after the optical path bending prism P of the first lens group G1, the most object side surface of the second lens group G2, and the object side surface of the fourth lens group G4. Used on three sides.

  As shown in FIG. 5, the zoom lens of Example 5 includes a negative meniscus lens convex on the object side, an optical path bending prism P, a negative meniscus lens convex on the object side, and a positive meniscus lens convex on the object side. A second lens group G2 composed of a cemented lens of a positive meniscus lens convex on the object side and a negative meniscus lens convex on the object side, and a biconvex positive lens. A third lens group G3 consisting of a single convex positive meniscus lens, a fourth lens group G4 consisting of a cemented lens of a biconvex positive lens and a negative meniscus lens convex on the image side, and zooming from the wide-angle end to the telephoto end. In doing so, the first lens group G1 and the fourth lens group G4 are fixed, the second lens group G2 moves to the object side together with the aperture stop S, and the third lens group G3 is once spaced from the second lens group G2. While expanding the image side Moved, then it moves toward the object side with a decreasing distance between the second lens group G2. In order to focus on a subject at a short distance, the third lens group G3 is extended to the object side.

  The aspherical surface is the image side surface of the negative meniscus lens immediately after the optical path bending prism P of the first lens group G1, the most object side surface of the second lens group G2, the object side surface of the third lens group G3, The fourth lens group G4 is used for the four surfaces closest to the object side.

As shown in FIG. 6, the zoom lens of Embodiment 6 includes a negative meniscus lens convex on the object side, an optical path bending prism P, a negative meniscus lens convex on the object side, and a positive meniscus lens convex on the object side. A second lens group G2 composed of a cemented lens of a positive meniscus lens convex on the object side and a negative meniscus lens convex on the object side, and a biconvex positive lens. A third lens group G3 consisting of a single convex positive meniscus lens, a fourth lens group G4 consisting of a cemented lens of a biconvex positive lens and a negative meniscus lens convex on the image side, and zooming from the wide-angle end to the telephoto end. In doing so, the first lens group G1 and the fourth lens group G4 are fixed, the second lens group G2 moves to the object side together with the aperture stop S, and the third lens group G3 is once spaced from the second lens group G2. While expanding the image side Moved, then it moves toward the object side with a decreasing distance between the second lens group G2. In order to focus on a subject at a short distance, the third lens group G3 is extended to the object side.

  The aspherical surface is the image side surface of the negative meniscus lens immediately after the optical path bending prism P of the first lens group G1, the most object side surface of the second lens group G2, and the most object side surface of the fourth lens group G4. Are used on the three sides.

  As shown in FIG. 7, the zoom lens of Example 7 includes a negative meniscus lens convex on the object side, an optical path bending prism P, a negative meniscus lens convex on the object side, and a positive meniscus lens convex on the object side. A second lens group G2 composed of a cemented lens of a positive meniscus lens convex on the object side and a negative meniscus lens convex on the object side, and a biconvex positive lens. A third lens group G3 composed of a single convex positive meniscus lens, and a fourth lens group G4 composed of a cemented lens composed of a negative meniscus lens convex to the object side and a biconvex positive lens, and zooming from the wide angle end to the telephoto end. At this time, the first lens group G1 and the fourth lens group G4 are fixed, the second lens group G2 is moved to the object side together with the aperture stop S, and the third lens group G3 is once spaced from the second lens group G2. Image side while spreading Moved, then it moves toward the object side with a decreasing distance between the second lens group G2. In order to focus on a subject at a short distance, the third lens group G3 is extended to the object side.

  The aspherical surfaces are 3 of the image surface side surface of the negative meniscus lens closest to the object side of the first lens group G1, the surface closest to the object side of the second lens group G2, and the surface closest to the image surface side of the fourth lens group G4. Used on the surface.

  As shown in FIG. 8, the zoom lens of Example 8 includes a negative meniscus lens convex on the object side, an optical path bending prism P, a cemented lens of a biconcave negative lens and a positive meniscus lens convex on the object side. First lens group G1, aperture stop S, second lens group G2 composed of a cemented lens of a positive meniscus lens convex on the object side and a negative meniscus lens convex on the object side, and a biconvex positive lens, convex on the object side A third lens group G3 consisting of a single positive meniscus lens, a fourth lens group G4 consisting of a cemented lens of a biconvex positive lens and a negative meniscus lens convex on the image side, and zooming from the wide-angle end to the telephoto end The first lens group G1 and the fourth lens group G4 are fixed, the second lens group G2 moves to the object side together with the aperture stop S, and the third lens group G3 temporarily widens the distance from the second lens group G2. While moving to the image side Then move to the object side with a decreasing distance between the second lens group G2. In order to focus on a subject at a short distance, the third lens group G3 is extended to the object side.

  The aspheric surfaces are used for the three surfaces of the negative meniscus lens surface of the first lens group G1, the most object side surface of the second lens group G2, and the most object side surface of the fourth lens group G4. Yes.

  As shown in FIG. 9, the zoom lens of Example 9 includes a negative meniscus lens convex toward the object side, an optical path bending prism P, a negative meniscus lens convex toward the image surface side, and a positive meniscus lens convex toward the image surface side. A first lens group G1 composed of a cemented lens, an aperture stop S, a biconvex positive lens, a second lens group G2 composed of a cemented lens of a convex plano-positive lens and a plano-concave negative lens, and a first lens composed of one biconvex positive lens. The third lens group G3 is composed of a fourth lens group G4 composed of a cemented lens of a biconvex positive lens and a negative meniscus lens convex on the image side. When zooming from the wide-angle end to the telephoto end, the first lens group G1, The fourth lens group G4 is fixed, the second lens group G2 moves to the object side together with the aperture stop S, and the third lens group G3 moves to the object side while temporarily increasing the distance from the second lens group G2 and then shrinking it. . In order to focus on a subject at a short distance, the third lens group G3 is extended to the object side.

  The aspherical surfaces are the three surfaces of the first lens group G1, the most object side surface of the negative meniscus lens, the second lens group G2, the most object side surface, and the fourth lens group G4, the most object side surface. It is used for.

  As shown in FIG. 10, the zoom lens according to the tenth embodiment includes a first negative meniscus lens that is convex on the object side, an optical path bending prism P, a biconcave negative lens, and a positive meniscus lens that is convex on the object side. A second lens group G2 including a cemented lens of a lens group G1, an aperture stop S, a positive meniscus lens convex on the object side and a negative meniscus lens convex on the object side, and a biconvex positive lens; a positive meniscus convex on the object side The third lens group G3 consists of a single lens, and the fourth lens group G4 consists of a cemented lens composed of a negative meniscus lens convex on the image side and a positive meniscus lens convex on the image side, and changes from the wide-angle end to the telephoto end. When magnifying, the first lens group G1 and the fourth lens group G4 are fixed, the second lens group G2 moves to the object side together with the aperture stop S, and the third lens group G3 temporarily contacts the second lens group G2. Statue with wide spacing Move to the side, and then moves toward the object side with a decreasing distance between the second lens group G2. In order to focus on a subject at a short distance, the third lens group G3 is extended to the object side.

  The aspheric surfaces are the image side surface of the biconcave negative lens immediately after the optical path bending prism P of the first lens group G1, the most object side surface of the second lens group G2, and the object side surface of the third lens group G3. The fourth lens group G4 is used for the four surfaces closest to the image plane.

  As shown in FIG. 11, the zoom lens according to the eleventh embodiment includes a first meniscus lens including a negative meniscus lens convex on the object side, an optical path bending prism P, a biconcave negative lens, and a positive meniscus lens convex on the object side. A second lens group G2 including a cemented lens of a lens group G1, an aperture stop S, a positive meniscus lens convex on the object side and a negative meniscus lens convex on the object side, and a biconvex positive lens; a positive meniscus convex on the object side The third lens group G3 consists of a single lens, and the fourth lens group G4 consists of a cemented lens composed of a negative meniscus lens convex on the image side and a positive meniscus lens convex on the image side, and changes from the wide-angle end to the telephoto end. When magnifying, the first lens group G1 and the fourth lens group G4 are fixed, the second lens group G2 moves to the object side together with the aperture stop S, and the third lens group G3 temporarily contacts the second lens group G2. Statue with wide spacing Move to the side, and then moves toward the object side with a decreasing distance between the second lens group G2. In order to focus on a subject at a short distance, the third lens group G3 is extended to the object side.

  The aspherical surfaces are four surfaces of the double-concave negative lens immediately after the optical path bending prism P of the first lens group G1, the most object-side surface of the second lens group G2, and the most image-side surface of the fourth lens group G4. Used on the surface.

  As shown in FIG. 12, the zoom lens according to the twelfth embodiment includes a negative meniscus lens convex toward the object side, an optical path bending prism P, a biconcave negative lens, and a positive meniscus lens convex toward the object side. A second lens group G2 including a cemented lens of a lens group G1, an aperture stop S, a positive meniscus lens convex on the object side and a negative meniscus lens convex on the object side, and a biconvex positive lens; a positive meniscus convex on the object side A third lens group G3 consisting of a single lens, and a fourth lens group G4 consisting of a cemented lens of a negative meniscus lens convex to the object side and a biconvex positive lens. When zooming from the wide angle end to the telephoto end, The first lens group G1 and the fourth lens group G4 are fixed, the second lens group G2 moves to the object side together with the aperture stop S, and the third lens group G3 temporarily increases the distance between the second lens group G2 and the image plane. Move to the side and its It moves toward the object side with a decreasing distance between the second lens group G2. In order to focus on a subject at a short distance, the third lens group G3 is extended to the object side.

The aspheric surfaces are used for the three surfaces of the negative meniscus lens surface of the first lens group G1, the most object side surface of the second lens group G2, and the most image surface side of the fourth lens group G4. ing.

  The first lens group G1 of Examples 1 to 12 above constitutes the lens group A of the present invention, and the second lens group G2 constitutes the lens group B of the present invention.

  As shown in FIG. 13, the zoom lens according to the thirteenth embodiment includes a first lens group G1-1 including an optical path bending prism P equivalent to a concave flat negative lens, a negative meniscus lens concave on the object side, and an object side. First-second lens unit G1-2 including a cemented lens of a concave positive meniscus lens, a cemented lens of an aperture stop, a biconvex positive lens, a positive meniscus lens convex on the object side, and a negative meniscus lens convex on the object side A second lens group G2 consisting of: a third lens group G3 consisting of a biconvex positive lens, and a fourth lens group G4 consisting of a positive meniscus lens convex on the image plane side, and when zooming from the wide angle end to the telephoto end The second lens group G2 and the third lens group G3 move to the object side while narrowing the distance between them once widened.

  The aspherical surfaces are the object side surface of the optical path bending prism P of the 1-1st lens group G1-1, the most object side surface of the 2nd lens group G2, and the image surface side of the positive meniscus lens of the 4th lens group G4. It is used for three surfaces.

  In Example 13, the first-first lens group G1-1 and the first-second lens group G1-2 constitute the lens group A of the present invention, and the second lens group G2 constitutes the lens group B of the present invention. is doing.

Hereinafter, numerical data of each embodiment described above, but the symbols are outside the above, f is the focal length, 2 [omega angle of view, F _NO is the F-number, WE wide-angle end, ST intermediate state, TE is The telephoto end, r ₁ , r ₂ ... Is the radius of curvature of each lens surface, d ₁ , d ₂ ... _Are the distances between the lens surfaces, n _d1 , n _d2 are the refractive index of the d-line of each lens, ν _d1 , ν _d2 ... is the Abbe number of each lens. The aspherical shape is represented by the following formula, where x is an optical axis with the light traveling direction being positive, and y is a direction orthogonal to the optical axis.

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

Example 1
r ₁ = 14.8444 d ₁ = 1.2000 n _d1 = 1.80610 ν _d1 = 40.92
r ₂ = 7.9462 d ₂ = 2.9000
r ₃ = ∞ d ₃ = 12.5000 n _d2 = 1.78590 ν _d2 = 44.20
r ₄ = ∞ d ₄ = 0.4100
r ₅ = -29.2456 d ₅ = 1.0000 n _d3 = 1.80610 ν _d3 = 40.92
r ₆ = 9.2661 (aspherical surface) d ₆ = 1.0000
r ₇ = 15.5357 d ₇ = 1.8200 n _d4 = 1.71736 ν _d4 = 29.52
r ₈ = -23.5495 d ₈ = (variable)
r ₉ = ∞ (aperture) d ₉ = 1.0000
r ₁₀ = 8.5761 (aspherical surface) d ₁₀ = 2.3000 n _d5 = 1.80610 ν _d5 = 40.92
r ₁₁ = -36.3441 d ₁₁ = 0.1500
r ₁₂ = 15.2953 d ₁₂ = 2.7000 n _d6 = 1.69350 ν _d6 = 53.21
r ₁₃ = -15.0000 d ₁₃ = 0.8000 n _d7 = 1.80518 ν _d7 = 25.42
r ₁₄ = 5.3453 d ₁₄ = (variable)
r ₁₅ = 16.7201 d ₁₅ = 1.6000 n _d8 = 1.48749 ν _d8 = 70.23
r ₁₆ = -486.1483 d ₁₆ = (variable)
r ₁₇ = 28.4526 d ₁₇ = 1.7000 n _d9 = 1.58313 ν _d9 = 59.38
r ₁₈ = -34.4702 (aspherical surface) d ₁₈ = 0.6600
r ₁₉ = ∞ d ₁₉ = 1.4400 n _d10 = 1.54771 ν _d10 = 62.84
r ₂₀ = ∞ d ₂₀ = 0.8000
r ₂₁ = ∞ d ₂₁ = 0.6000 n _d11 = 1.51633 ν _d11 = 64.14
r ₂₂ = ∞ d ₂₂ = 1.3598
r ₂₃ = ∞ (image plane)
Aspheric coefficient 6th surface K = 0
A ₄ = -3.5636 × 10 ^-4
A ₆ = 5.2749 × 10 ^-6
A ₈ = -2.9541 × 10 ^-7
A ₁₀ = 5.5683 × 10 ^-9
10th surface K = 0
A ₄ = -2.3319 × 10 ^-4
A ₆ = -9.0916 × 10 ^-7
A ₈ = -3.8758 × 10 ^-8
A ₁₀ = 0.0000
18th face K = 0
A ₄ = 4.8568 × 10 ^-4
A ₆ = -3.3258 × 10 ^-5
A ₈ = 1.7328 × 10 ^-6
A ₁₀ = -3.3044 × 10 ^-8
Zoom data (∞)
WE ST TE
f (mm) 6.00491 9.33131 14.49908
F _NO 2.8494 3.6391 4.5331
2ω (°) 32.7 21.4 13.9
d ₈ 14.59760 7.77126 1.49983
d ₁₄ 1.99990 7.34104 5.91654
d ₁₆ 5.46534 6.96338 14.64643.

Example 2
r ₁ = 18.3518 d ₁ = 1.2000 n _d1 = 1.78590 ν _d1 = 44.20
r ₂ = 8.4466 d ₂ = 2.9000
r ₃ = ∞ d ₃ = 12.5000 n _d2 = 1.78590 ν _d2 = 44.20
r ₄ = ∞ d ₄ = 0.5000
r ₅ = 1113.2775 d ₅ = 1.0000 n _d3 = 1.74320 ν _d3 = 49.34
r ₆ = 8.4738 (aspherical surface) d ₆ = 0.8000
r ₇ = 10.8733 d ₇ = 2.0000 n _d4 = 1.72825 ν _d4 = 28.46
r ₈ = 156.2997 d ₈ = (variable)
r ₉ = ∞ (aperture) d ₉ = 1.0000
r ₁₀ = 17.7870 d ₁₀ = 0.7000 n _d5 = 1.84666 ν _d5 = 23.78
r ₁₁ = 9.5000 d ₁₁ = 2.0000 n _d6 = 1.53172 ν _d6 = 48.84
r ₁₂ = -16.0207 d ₁₂ = (variable)
r ₁₃ = 4.2286 (aspherical surface) d ₁₃ = 2.5000 n _d7 = 1.69350 ν _d7 = 53.21
r ₁₄ = 5.4000 d ₁₄ = 0.7000 n _d8 = 1.84666 ν _d8 = 23.78
r ₁₅ = 3.0911 d ₁₅ = 0.9300
r ₁₆ = 7.7824 d ₁₆ = 1.5000 n _d9 = 1.51633 ν _d9 = 64.14
r ₁₇ = 15.1208 d ₁₇ = (variable)
r ₁₈ = -12.0255 d ₁₈ = 1.8000 n _d10 = 1.51633 ν _d10 = 64.14
r ₁₉ = -6.7836 (aspherical surface) d ₁₉ = 0.6600
r ₂₀ = ∞ d ₂₀ = 1.4400 n _d11 = 1.54771 ν _d11 = 62.84
r ₂₁ = ∞ d ₂₁ = 0.8000
r ₂₂ = ∞ d ₂₂ = 0.6000 n _d12 = 1.51633 ν _d12 = 64.14
r ₂₃ = ∞ d ₂₃ = 1.3603
r ₂₄ = ∞ (image plane)
Aspheric coefficient 6th surface K = 0
A ₄ = -1.2289 × 10 ^-4
A ₆ = -5.3381 × 10 ^-6
A ₈ = 8.7422 × 10 ^-8
A ₁₀ = -3.3652 × 10 ^-11
13th surface K = 0
A ₄ = -1.9805 × 10 ^-4
A ₆ = -2.8934 × 10 ^-5
A ₈ = 1.9147 × 10 ^-6
A ₁₀ = -1.9986 × 10 ^-7
19th face K = 0
A ₄ = 8.1993 × 10 ^-4
A ₆ = -1.1656 × 10 ^-5
A ₈ = -3.0739 × 10 ^-7
A ₁₀ = 0.0000
Zoom data (∞)
WE ST TE
f (mm) 6.00484 9.32900 14.49815
F _NO 2.8586 3.5391 4.4656
2ω (°) 32.7 21.2 14.0
d ₈ 14.82338 7.17554 1.49960
d ₁₂ 1.39943 6.88233 7.06951
d ₁₇ 4.89357 7.02815 12.54751.

Example 3
r ₁ = 18.4212 d ₁ = 1.2000 n _d1 = 1.78590 ν _d1 = 44.20
r ₂ = 8.6018 d ₂ = 2.9000
r ₃ = ∞ d ₃ = 12.5000 n _d2 = 1.78590 ν _d2 = 44.20
r ₄ = ∞ d ₄ = 0.5000
r ₅ = 62.7612 d ₅ = 1.0000 n _d3 = 1.74320 ν _d3 = 49.34
r ₆ = 6.4831 (aspherical surface) d ₆ = 0.8000
r ₇ = 9.0709 d ₇ = 2.0000 n _d4 = 1.72825 ν _d4 = 28.46
r ₈ = 107.5707 d ₈ = (variable)
r ₉ = ∞ (aperture) d ₉ = 1.0000
r ₁₀ = 12.3123 d ₁₀ = 0.7000 n _d5 = 1.84666 ν _d5 = 23.78
r ₁₁ = 7.0000 d ₁₁ = 2.0000 n _d6 = 1.58313 ν _d6 = 59.38
r ₁₂ = -25.6683 d ₁₂ = (variable)
r ₁₃ = 4.7382 (aspherical surface) d ₁₃ = 2.5000 n _d7 = 1.80610 ν _d7 = 40.92
r ₁₄ = 3.4603 d ₁₄ = 0.9300
r ₁₅ = 7.8166 d ₁₅ = 2.0000 n _d8 = 1.48749 ν _d8 = 70.23
r ₁₆ = -7.2953 d ₁₆ = 0.7000 n _d9 = 1.83400 ν _d9 = 37.16
r ₁₇ = -69.1622 d ₁₇ = (variable)
r ₁₈ = 220.1623 d ₁₈ = 1.8000 n _d10 = 1.51633 ν _d10 = 64.14
r ₁₉ = -14.8379 (aspherical surface) d ₁₉ = 0.6600
r ₂₀ = ∞ d ₂₀ = 1.4400 n _d11 = 1.54771 ν _d11 = 62.84
r ₂₁ = ∞ d ₂₁ = 0.8000
r ₂₂ = ∞ d ₂₂ = 0.6000 n _d12 = 1.51633 ν _d12 = 64.14
r ₂₃ = ∞ d ₂₃ = 1.3610
r ₂₄ = ∞ (image plane)
Aspheric coefficient 6th surface K = 0
A ₄ = -3.8689 × 10 ^-4
A ₆ = -4.0903 × 10 ^-7
A ₈ = -3.1388 × 10 ^-7
A ₁₀ = 4.2432 × 10 ^-9
13th surface K = 0
A ₄ = -1.1413 × 10 ^-5
A ₆ = 1.9818 × 10 ^-6
A ₈ = -3.1231 × 10 ^-7
A ₁₀ = 0.0000
19th face K = 0
A ₄ = 4.8219 × 10 ^-4
A ₆ = -1.8188 × 10 ^-5
A ₈ = 2.6094 × 10 ^-7
A ₁₀ = 0.0000
Zoom data (∞)
WE ST TE
f (mm) 6.00765 9.33160 14.49720
F _NO 2.8190 3.5028 4.4438
2ω (°) 32.7 21.2 13.9
d ₈ 14.09558 6.85361 1.49984
d ₁₂ 1.40013 6.67003 5.54950
d ₁₇ 5.11617 7.07754 13.56271.

Example 4
r ₁ = 20.3735 d ₁ = 1.2000 n _d1 = 1.78590 ν _d1 = 44.20
r ₂ = 8.8056 d ₂ = 2.9000
r ₃ = ∞ d ₃ = 12.5000 n _d2 = 1.78590 ν _d2 = 44.20
r ₄ = ∞ d ₄ = 0.3000
r ₅ = 91.5080 d ₅ = 0.9000 n _d3 = 1.80610 ν _d3 = 40.92
r ₆ = 6.4940 (aspherical surface) d ₆ = 0.1400
r ₇ = 7.2843 d ₇ = 2.2000 n _d4 = 1.74000 ν _d4 = 28.30
r ₈ = 146.5397 d ₈ = (variable)
r ₉ = ∞ (aperture) d ₉ = 1.0000
r ₁₀ = 5.1758 (aspherical surface) d ₁₀ = 2.5000 n _d5 = 1.74320 ν _d5 = 49.34
r ₁₁ = 9.0000 d ₁₁ = 0.7000 n _d6 = 1.84666 ν _d6 = 23.78
r ₁₂ = 4.6154 d ₁₂ = 0.9300
r ₁₃ = 17.8685 d ₁₃ = 1.5000 n _d7 = 1.72916 ν _d7 = 54.68
r ₁₄ = -34.0913 d ₁₄ = (variable)
r ₁₅ = 10.1880 d ₁₅ = 1.9600 n _d8 = 1.77250 ν _d8 = 49.60
r ₁₆ = -50.0000 d ₁₆ = 0.7000 n _d9 = 1.67270 ν _d9 = 32.10
r ₁₇ = 10.2079 d ₁₇ = (variable)
r ₁₈ = 23.9392 (aspherical surface) d ₁₈ = 1.8000 n _d10 = 1.58313 ν _d10 = 59.38
r ₁₉ = -44.7453 d ₁₉ = 0.6600
r ₂₀ = ∞ d ₂₀ = 1.4400 n _d11 = 1.54771 ν _d11 = 62.84
r ₂₁ = ∞ d ₂₁ = 0.8000
r ₂₂ = ∞ d ₂₂ = 0.6000 n _d12 = 1.51633 ν _d12 = 64.14
r ₂₃ = ∞ d ₂₃ = 1.3599
r ₂₄ = ∞ (image plane) Aspheric coefficient 6th surface K = 0
A ₄ = -2.8088 × 10 ^-4
A ₆ = 2.6396 × 10 ^-6
A ₈ = -4.8363 × 10 ^-7
A ₁₀ = 9.0705 × 10 ^-9
10th surface K = 0
A ₄ = -3.1977 × 10 ^-4
A ₆ = -2.1006 × 10 ^-6
A ₈ = -7.1881 × 10 ^-7
A ₁₀ = 0.0000
18th face K = 0
A ₄ = -2.6755 × 10 ^-4
A ₆ = 3.6472 × 10 ^-6
A ₈ = -2.1043 × 10 ^-7
A ₁₀ = 0.0000
Zoom data (∞)
WE ST TE
f (mm) 6.01024 9.33049 14.49490
F _NO 2.8184 3.5212 4.3375
2ω (°) 32.6 21.6 13.9
d ₈ 14.61596 7.52861 1.49916
d ₁₄ 1.39873 7.91160 7.03236
d ₁₇ 5.91073 6.48903 13.39408.

Example 5
r ₁ = 17.9860 d ₁ = 1.2000 n _d1 = 1.78590 ν _d1 = 44.20
r ₂ = 8.3182 d ₂ = 2.9000
r ₃ = ∞ d ₃ = 12.5000 n _d2 = 1.78590 ν _d2 = 44.20
r ₄ = ∞ d ₄ = 0.3000
r ₅ = 72.7266 d ₅ = 0.9000 n _d3 = 1.58313 ν _d3 = 59.38
r ₆ = 5.2266 (aspherical surface) d ₆ = 0.4400
r ₇ = 7.1726 d ₇ = 1.9000 n _d4 = 1.83400 ν _d4 = 37.16
r ₈ = 22.4388 d ₈ = (variable)
r ₉ = ∞ (aperture) d ₉ = 1.0000
r ₁₀ = 5.2528 (aspherical surface) d ₁₀ = 2.5000 n _d5 = 1.74320 ν _d5 = 49.34
r ₁₁ = 10.0000 d ₁₁ = 0.7000 n _d6 = 1.84666 ν _d6 = 23.78
r ₁₂ = 4.6454 d ₁₂ = 0.8000
r ₁₃ = 13.3752 d ₁₃ = 1.5000 n _d7 = 1.72916 ν _d7 = 54.68
r ₁₄ = -37.9999 d ₁₄ = (variable)
r ₁₅ = 10.5633 (aspherical surface) d ₁₅ = 1.4000 n _d8 = 1.48749 ν _d8 = 70.23
r ₁₆ = 15.0339 d ₁₆ = (variable)
r ₁₇ = 38.6419 (aspherical surface) d ₁₇ = 2.1000 n _d9 = 1.74320 ν _d9 = 49.34
r ₁₈ = -11.0000 d ₁₈ = 0.8000 n _d10 = 1.84666 ν _d10 = 23.78
r ₁₉ = -30.5080 d ₁₉ = 0.6600
r ₂₀ = ∞ d ₂₀ = 1.4400 n _d11 = 1.54771 ν _d11 = 62.84
r ₂₁ = ∞ d ₂₁ = 0.8000
r ₂₂ = ∞ d ₂₂ = 0.6000 n _d12 = 1.51633 ν _d12 = 64.14
r ₂₃ = ∞ d ₂₃ = 1.3598
r ₂₄ = ∞ (image plane) Aspheric coefficient 6th surface K = 0
A ₄ = -6.0228 × 10 ^-4
A ₆ = -1.9006 × 10 ^-5
A ₈ = 4.0887 × 10 ^-7
A ₁₀ = -4.9789 × 10 ^-8
10th surface K = 0
A ₄ = -2.8288 × 10 ^-4
A ₆ = -4.3087 × 10 ^-6
A ₈ = -4.8342 × 10 ^-7
A ₁₀ = 0.0000
15th surface K = 0
A ₄ = 1.4603 × 10 ^-5
A ₆ = -9.3569 × 10 ^-8
A ₈ = 2.0899 × 10 ^-7
A ₁₀ = 0.0000
Surface 17 K = 0
A ₄ = -1.8274 × 10 ^-4
A ₆ = 1.4781 × 10 ^-6
A ₈ = -1.2650 × 10 ^-7
A ₁₀ = 0.0000
Zoom data (∞)
WE ST TE
f (mm) 6.00754 9.32975 14.49731
F _NO 2.8495 3.5727 4.3700
2ω (°) 32.6 21.6 13.9
d ₈ 14.07403 7.43206 1.49953
d ₁₄ 1.39969 9.03177 6.40046
d ₁₆ 6.73599 5.75394 14.30980.

Example 6
r ₁ = 17.8001 d ₁ = 1.2000 n _d1 = 1.78590 ν _d1 = 44.20
r ₂ = 8.2437 d ₂ = 2.9000
r ₃ = ∞ d ₃ = 12.5000 n _d2 = 1.78590 ν _d2 = 44.20
r ₄ = ∞ d ₄ = 0.3000
r ₅ = 46.5308 d ₅ = 0.9000 n _d3 = 1.58313 ν _d3 = 59.38
r ₆ = 5.1472 (aspherical surface) d ₆ = 0.4400
r ₇ = 7.0137 d ₇ = 1.9000 n _d4 = 1.83400 ν _d4 = 37.16
r ₈ = 19.5923 d ₈ = (variable)
r ₉ = ∞ (aperture) d ₉ = 1.0000
r ₁₀ = 5.4144 (aspherical surface) d ₁₀ = 2.5000 n _d5 = 1.74320 ν _d5 = 49.34
r ₁₁ = 11.0000 d ₁₁ = 0.7000 n _d6 = 1.84666 ν _d6 = 23.78
r ₁₂ = 4.9373 d ₁₂ = 0.8000
r ₁₃ = 16.3823 d ₁₃ = 1.5000 n _d7 = 1.72916 ν _d7 = 54.68
r ₁₄ = -27.0398 d ₁₄ = (variable)
r ₁₅ = 9.6711 d ₁₅ = 1.4000 n _d8 = 1.48749 ν _d8 = 70.23
r ₁₆ = 12.8264 d ₁₆ = (variable)
r ₁₇ = 40.2313 (aspherical surface) d ₁₇ = 2.1000 n _d9 = 1.74320 ν _d9 = 49.34
r ₁₈ = -11.0000 d ₁₈ = 0.8000 n _d10 = 1.84666 ν _d10 = 23.78
r ₁₉ = -29.7083 d ₁₉ = 0.6600
r ₂₀ = ∞ d ₂₀ = 1.4400 n _d11 = 1.54771 ν _d11 = 62.84
r ₂₁ = ∞ d ₂₁ = 0.8000
r ₂₂ = ∞ d ₂₂ = 0.6000 n _d12 = 1.51633 ν _d12 = 64.14
r ₂₃ = ∞ d ₂₃ = 1.3602
r ₂₄ = ∞ (image plane) Aspheric coefficient 6th surface K = 0
A ₄ = -6.1045 × 10 ^-4
A ₆ = -2.1149 × 10 ^-5
A ₈ = 6.3248 × 10 ^-7
A ₁₀ = -6.3667 × 10 ^-8
10th surface K = 0
A ₄ = -2.8497 × 10 ^-4
A ₆ = -3.9160 × 10 ^-6
A ₈ = -4.1489 × 10 ^-7
A ₁₀ = 0.0000
Surface 17 K = 0
A ₄ = -1.5883 × 10 ^-4
A ₆ = -2.4464 × 10 ^-6
A ₈ = 4.8112 × 10 ^-8
A ₁₀ = 0.0000
Zoom data (∞)
WE ST TE
f (mm) 6.01250 9.32862 14.49489
F _NO 2.8398 3.5522 4.3431
2ω (°) 32.6 21.6 13.9
d ₈ 13.97559 7.36589 1.49906
d ₁₄ 1.39898 9.08823 6.32194
d ₁₆ 6.84047 5.77938 14.39408.

Example 7
r ₁ = 21.2933 d ₁ = 1.2000 n _d1 = 1.78590 ν _d1 = 44.20
r ₂ = 9.1188 (aspherical surface) d ₂ = 2.9000
r ₃ = ∞ d ₃ = 12.5000 n _d2 = 1.78590 ν _d2 = 44.20
r ₄ = ∞ d ₄ = 0.3000
r ₅ = 580.7411 d ₅ = 0.9000 n _d3 = 1.58267 ν _d3 = 46.42
r ₆ = 7.7517 d ₆ = 0.4400
r ₇ = 8.2515 d ₇ = 1.9000 n _d4 = 1.84666 ν _d4 = 23.78
r ₈ = 15.6144 d ₈ = (variable)
r ₉ = ∞ (aperture) d ₉ = 1.0000
r ₁₀ = 5.7808 (aspherical surface) d ₁₀ = 2.5000 n _d5 = 1.74320 ν _d5 = 49.34
r ₁₁ = 13.0000 d ₁₁ = 0.7000 n _d6 = 1.84666 ν _d6 = 23.78
r ₁₂ = 5.2982 d ₁₂ = 0.8000
r ₁₃ = 14.1056 d ₁₃ = 1.5000 n _d7 = 1.72916 ν _d7 = 54.68
r ₁₄ = -27.2119 d ₁₄ = (variable)
r ₁₅ = 13.7890 d ₁₅ = 1.4000 n _d8 = 1.48749 ν _d8 = 70.23
r ₁₆ = 20.8162 d ₁₆ = (variable)
r ₁₇ = 100.9793 d ₁₇ = 0.8000 n _d9 = 1.84666 ν _d9 = 23.78
r ₁₈ = 13.5000 d ₁₈ = 2.1000 n _d10 = 1.80610 ν _d10 = 40.92
r ₁₉ = -25.2224 (aspherical surface) d ₁₉ = 0.6600
r ₂₀ = ∞ d ₂₀ = 1.4400 n _d11 = 1.54771 ν _d11 = 62.84
r ₂₁ = ∞ d ₂₁ = 0.8000
r ₂₂ = ∞ d ₂₂ = 0.6000 n _d12 = 1.51633 ν _d12 = 64.14
r ₂₃ = ∞ d ₂₃ = 1.3601
r ₂₄ = ∞ (image plane) aspherical coefficient second surface K = 0
A ₄ = -1.4911 × 10 ^-5
A ₆ = -1.1650 × 10 ^-6
A ₈ = 4.2491 × 10 ^-9
A ₁₀ = 0.0000
10th surface K = 0
A ₄ = -2.3339 × 10 ^-4
A ₆ = -2.6427 × 10 ^-6
A ₈ = -2.6924 × 10 ^-7
A ₁₀ = 0.0000
19th face K = 0
A ₄ = 1.8090 × 10 ^-4
A ₆ = 4.1230 × 10 ^-6
A ₈ = -1.2807 × 10 ^-7
A ₁₀ = 0.0000
Zoom data (∞)
WE ST TE
f (mm) 6.00574 9.32712 14.49692
F _NO 2.8248 3.5310 4.2987
2ω (°) 32.7 21.5 13.9
d ₈ 13.57761 7.20846 1.49942
d ₁₄ 1.39965 9.63810 5.81790
d ₁₆ 7.23336 5.38063 14.89331.

Example 8
r ₁ = 19.1761 d ₁ = 1.2000 n _d1 = 1.78590 ν _d1 = 44.20
r ₂ = 8.5695 (aspherical surface) d ₂ = 2.9000
r ₃ = ∞ d ₃ = 12.5000 n _d2 = 1.78590 ν _d2 = 44.20
r ₄ = ∞ d ₄ = 0.3000
r ₅ = -46.5888 d ₅ = 0.9000 n _d3 = 1.58267 ν _d3 = 46.42
r ₆ = 10.3343 d ₆ = 1.9000 n _d4 = 1.84666 ν _d4 = 23.78
r ₇ = 26.0699 d ₇ = (variable)
r ₈ = ∞ (aperture) d ₈ = 1.0000
r ₉ = 6.0465 (aspherical surface) d ₉ = 2.5000 n _d5 = 1.74320 ν _d5 = 49.34
r ₁₀ = 13.0000 d ₁₀ = 0.7000 n _d6 = 1.84666 ν _d6 = 23.78
r ₁₁ = 5.6300 d ₁₁ = 0.8000
r ₁₂ = 15.1088 d ₁₂ = 1.5000 n _d7 = 1.72916 ν _d7 = 54.68
r ₁₃ = -28.7654 d ₁₃ = (variable)
r ₁₄ = 12.4863 d ₁₄ = 1.4000 n _d8 = 1.48749 ν _d8 = 70.23
r ₁₅ = 17.7361 d ₁₅ = (variable)
r ₁₆ = 24.3278 (aspherical surface) d ₁₆ = 2.1000 n _d9 = 1.74320 ν _d9 = 49.34
r ₁₇ = -12.0000 d ₁₇ = 0.8000 n _d10 = 1.78472 ν _d10 = 25.68
r ₁₈ = -75.9792 d ₁₈ = 0.6600
r ₁₉ = ∞ d ₁₉ = 1.4400 n _d11 = 1.54771 ν _d11 = 62.84
r ₂₀ = ∞ d ₂₀ = 0.8000
r ₂₁ = ∞ d ₂₁ = 0.6000 n _d12 = 1.51633 ν _d12 = 64.14
r ₂₂ = ∞ d ₂₂ = 1.3600
r ₂₃ = ∞ (image plane) aspherical coefficient second surface K = 0
A ₄ = -4.7160 × 10 ^-5
A ₆ = -7.1255 × 10 ^-7
A ₈ = -6.5873 × 10 ^-9
A ₁₀ = 0.0000
9th surface K = 0
A ₄ = -2.1357 × 10 ^-4
A ₆ = -2.1714 × 10 ^-6
A ₈ = -1.6484 × 10 ^-7
A ₁₀ = 0.0000
16th surface K = 0
A ₄ = -1.4451 × 10 ^-4
A ₆ = 1.3508 × 10 ^-6
A ₈ = -6.3819 × 10 ^-8
A ₁₀ = 0.0000
Zoom data (∞)
WE ST TE
f (mm) 6.00723 9.32846 14.49784
F _NO 2.8379 3.5413 4.3096
2ω (°) 32.7 21.5 13.9
d ₇ 13.98735 7.36539 1.49963
d ₁₃ 1.39974 9.60703 5.93291
d ₁₅ 7.26137 5.69110 15.21593.

Example 9
r ₁ = 246.0095 d ₁ = 1.2000 n _d1 = 1.80610 ν _d1 = 40.92
r ₂ = 20.1760 (aspherical surface) d ₂ = 1.5000
r ₃ = ∞ d ₃ = 12.5000 n _d2 = 1.78590 ν _d2 = 44.20
r ₄ = ∞ d ₄ = 1.5000
r ₅ = -7.3867 d ₅ = 1.0000 n _d3 = 1.80100 ν _d3 = 34.97
r ₆ = -50.0000 d ₆ = 1.8200 n _d4 = 1.84666 ν _d4 = 23.78
r ₇ = -12.2328 d ₇ = (variable)
r ₈ = ∞ (aperture) d ₈ = 1.0000
r ₉ = 10.6609 (aspherical surface) d ₉ = 2.3000 n _d5 = 1.80610 ν _d5 = 40.92
r ₁₀ = -67.8827 d ₁₀ = 0.1500
r ₁₁ = 13.1203 d ₁₁ = 2.7000 n _d6 = 1.75700 ν _d6 = 47.82
r ₁₂ = ∞ d ₁₂ = 0.8000 n _d7 = 1.84666 ν _d7 = 23.78
r ₁₃ = 6.4827 d ₁₃ = (variable)
r ₁₄ = 17.6756 d ₁₄ = 1.6000 n _d8 = 1.48749 ν _d8 = 70.23
r ₁₅ = -50.5413 d ₁₅ = (variable)
r ₁₆ = 15.9493 (aspherical surface) d ₁₆ = 1.7000 n _d9 = 1.58313 ν _d9 = 59.38
r ₁₇ = -15.0000 d ₁₇ = 0.8000 n _d10 = 1.84666 ν _d10 = 23.78
r ₁₈ = -46.4329 d ₁₈ = 0.6600
r ₁₉ = ∞ d ₁₉ = 1.4400 n _d11 = 1.54771 ν _d11 = 62.84
r ₂₀ = ∞ d ₂₀ = 0.8000
r ₂₁ = ∞ d ₂₁ = 0.6000 n _d12 = 1.51633 ν _d12 = 64.14
r ₂₂ = ∞ d ₂₂ = 1.3601
r ₂₃ = ∞ (image plane) aspherical coefficient second surface K = 0
A ₄ = -1.0773 × 10 ^-4
A ₆ = -3.3089 × 10 ^-7
A ₈ = -1.5283 × 10 ^-9
A ₁₀ = 0.0000
9th surface K = 0
A ₄ = -1.2210 × 10 ^-4
A ₆ = -1.3984 × 10 ^-8
A ₈ = -1.6300 × 10 ^-8
A ₁₀ = 0.0000
16th surface K = 0
A ₄ = -2.6736 × 10 ^-4
A ₆ = 1.3631 × 10 ^-5
A ₈ = -4.5357 × 10 ^-7
A ₁₀ = 0.0000
Zoom data (∞)
WE ST TE
f (mm) 5.99832 9.32950 14.50084
F _NO 2.6479 3.3092 4.0475
2ω (°) 32.6 21.4 13.9
d ₇ 15.07816 7.55691 1.00023
d ₁₃ 1.40041 6.49779 5.90725
d ₁₅ 6.09306 8.53155 15.66403.

Example 10
r ₁ = 16.8630 d ₁ = 1.1000 n _d1 = 1.77250 ν _d1 = 49.60
r ₂ = 8.7727 d ₂ = 3.0000
r ₃ = ∞ d ₃ = 12.5000 n _d2 = 1.83481 ν _d2 = 42.72
r ₄ = ∞ d ₄ = 0.3000
r ₅ = -43.7867 d ₅ = 0.9000 n _d3 = 1.58313 ν _d3 = 59.38
r ₆ = 5.4937 (aspherical surface) d ₆ = 0.5200
r ₇ = 7.8835 d ₇ = 1.9000 n _d4 = 1.80610 ν _d4 = 40.92
r ₈ = 41.6500 d ₈ = (variable)
r ₉ = ∞ (aperture) d ₉ = 1.0000
r ₁₀ = 5.6352 (aspherical surface) d ₁₀ = 2.5000 n _d5 = 1.74320 ν _d5 = 49.34
r ₁₁ = 10.5000 d ₁₁ = 0.7000 n _d6 = 1.84666 ν _d6 = 23.78
r ₁₂ = 5.2717 d ₁₂ = 0.8000
r ₁₃ = 27.0282 d ₁₃ = 1.5000 n _d7 = 1.72916 ν _d7 = 54.68
r ₁₄ = -19.3196 d ₁₄ = (variable)
r ₁₅ = 17.7925 (aspherical surface) d ₁₅ = 1.4000 n _d8 = 1.48749 ν _d8 = 70.23
r ₁₆ = 121.8190 d ₁₆ = (variable)
r ₁₇ = -6.1686 d ₁₇ = 0.8000 n _d9 = 1.84666 ν _d9 = 23.78
r ₁₈ = -12.5000 d ₁₈ = 2.1000 n _d10 = 1.74320 ν _d10 = 49.34
r ₁₉ = -5.4525 (aspherical surface) d ₁₉ = 0.6600
r ₂₀ = ∞ d ₂₀ = 1.4400 n _d11 = 1.54771 ν _d11 = 62.84
r ₂₁ = ∞ d ₂₁ = 0.8000
r ₂₂ = ∞ d ₂₂ = 0.6000 n _d12 = 1.51633 ν _d12 = 64.14
r ₂₃ = ∞ d ₂₃ = 1.3600
r ₂₄ = ∞ (image plane) Aspheric coefficient 6th surface K = 0
A ₄ = -6.5162 × 10 ^-4
A ₆ = -9.3748 × 10 ^-6
A ₈ = 2.0963 × 10 ^-7
A ₁₀ = -3.4547 × 10 ^-8
10th surface K = 0
A ₄ = -2.9965 × 10 ^-4
A ₆ = -3.4364 × 10 ^-9
A ₈ = -4.7103 × 10 ^-7
A ₁₀ = 0.0000
15th surface K = 0
A ₄ = -9.8531 × 10 ^-7
A ₆ = 2.0729 × 10 ^-6
A ₈ = -3.4211 × 10 ^-8
A ₁₀ = 0.0000
19th face K = 0
A ₄ = 1.0008 × 10 ^-3
A ₆ = -1.7464 × 10 ^-5
A ₈ = 1.1785 × 10 ^-6
A ₁₀ = 0.0000
Zoom data (∞)
WE ST TE
f (mm) 6.01706 10.39915 17.99747
F _NO 2.8430 3.7925 4.6965
2ω (°) 32.6 19.3 11.3
d ₈ 18.39512 9.82836 1.49931
d ₁₄ 1.39990 11.66800 9.86995
d ₁₆ 8.11544 6.41342 16.54158.

Example 11
r ₁ = 18.1242 d ₁ = 1.1000 n _d1 = 1.77250 ν _d1 = 49.60
r ₂ = 11.0917 d ₂ = 3.0000
r ₃ = ∞ d ₃ = 12.5000 n _d2 = 1.80610 ν _d2 = 40.92
r ₄ = ∞ d ₄ = 0.3000
r ₅ = -189.0024 (aspherical surface) d ₅ = 0.9000 n _d3 = 1.80610 ν _d3 = 40.92
r ₆ = 7.0839 (aspherical surface) d ₆ = 0.8000
r ₇ = 8.8339 d ₇ = 1.9000 n _d4 = 1.76182 ν _d4 = 26.52
r ₈ = 33.9090 d ₈ = (variable)
r ₉ = ∞ (aperture) d ₉ = 1.0000
r ₁₀ = 6.5543 (aspherical surface) d ₁₀ = 2.5000 n _d5 = 1.74320 ν _d5 = 49.34
r ₁₁ = 16.5000 d ₁₁ = 0.7000 n _d6 = 1.84666 ν _d6 = 23.78
r ₁₂ = 6.8813 d ₁₂ = 0.8000
r ₁₃ = 110.5063 d ₁₃ = 1.5000 n _d7 = 1.72916 ν _d7 = 54.68
r ₁₄ = -13.4784 d ₁₄ = (variable)
r ₁₅ = 17.0895 d ₁₅ = 1.4000 n _d8 = 1.48749 ν _d8 = 70.23
r ₁₆ = 214.7721 d ₁₆ = (variable)
r ₁₇ = -8.1890 d ₁₇ = 0.8000 n _d9 = 1.84666 ν _d9 = 23.78
r ₁₈ = -20.0000 d ₁₈ = 2.1000 n _d10 = 1.74320 ν _d10 = 49.34
r ₁₉ = -7.6979 (aspherical surface) d ₁₉ = 0.6600
r ₂₀ = ∞ d ₂₀ = 1.4400 n _d11 = 1.54771 ν _d11 = 62.84
r ₂₁ = ∞ d ₂₁ = 0.8000
r ₂₂ = ∞ d ₂₂ = 0.6000 n _d12 = 1.51633 ν _d12 = 64.14
r ₂₃ = ∞ d ₂₃ = 1.3601
r ₂₄ = ∞ (image plane) Aspheric coefficient Fifth surface K = 0
A ₄ = 3.1801 × 10 ^-4
A ₆ = -7.4933 × 10 ^-6
A ₈ = 1.3268 × 10 ^-7
A ₁₀ = 0.0000
6th surface K = 0
A ₄ = 1.0755 × 10 ^-4
A ₆ = -2.2069 × 10 ^-6
A ₈ = -4.2215 × 10 ^-8
A ₁₀ = 1.2946 × 10 ^-9
10th surface K = 0
A ₄ = -2.8130 × 10 ^-4
A ₆ = -7.1076 × 10 ^-7
A ₈ = -1.7424 × 10 ^-7
A ₁₀ = 0.0000
19th face K = 0
A ₄ = 5.5956 × 10 ^-4
A ₆ = -1.7107 × 10 ^-5
A ₈ = 5.6651 × 10 ^-7
A ₁₀ = 0.0000
Zoom data (∞)
WE ST TE
f (mm) 6.00227 10.39870 17.99964
F _NO 2.8302 3.7274 4.5463
2ω (°) 32.7 19.3 11.3
d ₈ 17.74229 9.38185 1.50012
d ₁₄ 1.39992 10.71211 9.41560
d ₁₆ 7.69801 6.74827 15.92451.

Example 12
r ₁ = 11.6487 d ₁ = 0.7000 n _d1 = 1.77250 ν _d1 = 49.60
r ₂ = 4.8810 (aspherical surface) d ₂ = 1.5500
r ₃ = ∞ d ₃ = 6.8000 n _d2 = 1.77250 ν _d2 = 49.60
r ₄ = ∞ d ₄ = 0.1500
r ₅ = -170.6138 d ₅ = 0.7000 n _d3 = 1.77250 ν _d3 = 49.60
r ₆ = 6.6934 d ₆ = 0.5000
r ₇ = 6.6793 d ₇ = 1.2500 n _d4 = 1.84666 ν _d4 = 23.78
r ₈ = 13.3262 d ₈ = (variable)
r ₉ = ∞ (aperture) d ₉ = 0.0000
r ₁₀ = 3.9559 (aspherical surface) d ₁₀ = 1.8000 n _d5 = 1.74320 ν _d5 = 49.34
r ₁₁ = 9.5000 d ₁₁ = 0.7000 n _d6 = 1.84666 ν _d6 = 23.78
r ₁₂ = 3.5668 d ₁₂ = 0.5000
r ₁₃ = 7.5793 d ₁₃ = 1.6500 n _d7 = 1.72916 ν _d7 = 54.68
r ₁₄ = -14.4945 d ₁₄ = (variable)
r ₁₅ = 9.1093 d ₁₅ = 1.0000 n _d8 = 1.48749 ν _d8 = 70.23
r ₁₆ = 13.6404 d ₁₆ = (variable)
r ₁₇ = 146.0359 d ₁₇ = 0.7000 n _d9 = 1.84666 ν _d9 = 23.78
r ₁₈ = 9.0000 d ₁₈ = 1.4500 n _d10 = 1.74320 ν _d10 = 49.34
r ₁₉ = -22.2698 (aspherical surface) d ₁₉ = 0.7000
r ₂₀ = ∞ d ₂₀ = 0.6000 n _d11 = 1.51633 ν _d11 = 64.14
r ₂₁ = ∞ d ₂₁ = 1.0000
r ₂₂ = ∞ (image plane)
Aspherical coefficient second surface K = 0
A ₄ = -7.6360 × 10 ^-5
A ₆ = -3.2706 × 10 ^-5
A ₈ = 4.2217 × 10 ^-7
A ₁₀ = 0.0000
10th surface K = 0
A ₄ = -9.5407 × 10 ^-4
A ₆ = -1.7864 × 10 ^-5
A ₈ = -3.9103 × 10 ^-6
A ₁₀ = 0.0000
19th face K = 0
A ₄ = 2.5017 × 10 ^-5
A ₆ = 5.7463 × 10 ^-4
A ₈ = -6.4941 × 10 ^-5
A ₁₀ = 0.0000
Zoom data (∞)
WE ST TE
f (mm) 3.25717 5.63806 9.74723
F _NO 2.5244 3.3633 4.2965
2ω (°) 32.7 19.4 11.3
d ₈ 9.37157 4.85881 0.89899
d ₁₄ 1.10006 8.11201 1.30017
d ₁₆ 3.67578 1.18818 11.94819.

Example 13 r ₁ = -14.2761 (aspherical surface) d ₁ = 5.1000 n _d1 = 1.50913 ν _d1 = 56.20
r ₂ = ∞ (reflecting surface) d ₂ = 5.7941 n _d2 = 1.50913 ν _d2 = 56.20
r ₃ = ∞ d ₃ = 2.1000
r ₄ = -6.4892 d ₄ = 0.8000 n _d3 = 1.64000 ν _d3 = 60.07
r ₅ = -84.1654 d ₅ = 1.1935 n _d4 = 1.84666 ν _d4 = 23.78
r ₆ = -16.8306 d ₆ = (variable)
r ₇ = ∞ (aperture) d ₇ = 0.4000
r ₈ = 34.9225 (aspherical surface) d ₈ = 1.4006 n _d5 = 1.74330 ν _d5 = 49.33
r ₉ = -15.2934 d ₉ = 0.1500
r ₁₀ = 6.1210 d ₁₀ = 3.3481 n _d6 = 1.61800 ν _d6 = 63.33
r ₁₁ = 27.4556 d ₁₁ = 0.8000 n _d7 = 1.84666 ν _d7 = 23.78
r ₁₂ = 4.9467 d ₁₂ = (variable)
r ₁₃ = 13.6380 d ₁₃ = 1.4415 n _d8 = 1.51633 ν _d8 = 64.14
r ₁₄ = -143.7586 d ₁₄ = (variable)
r ₁₅ = -19.5436 d ₁₅ = 1.3641 n _d9 = 1.58913 ν _d9 = 61.25
r ₁₆ = -7.1346 (aspherical surface) d ₁₆ = 0.8000
r ₁₇ = ∞ d ₁₇ = 1.0500 n _d10 = 1.54771 ν _d10 = 62.84
r ₁₈ = ∞ d ₁₈ = 0.8000
r ₁₉ = ∞ d ₁₉ = 0.8000 n _d11 = 1.51633 ν _d11 = 64.14
r ₂₀ = ∞ d ₂₀ = 0.9669
r ₂₁ = ∞ (image plane)
Aspheric coefficient 1st surface K = 0
A ₄ = 3.2165 × 10 ^-4
A ₆ = -9.1756 × 10 ^-7
A ₈ = 4.1788 × 10 ^-9
A ₁₀ = 0.0000
8th surface K = 0
A ₄ = -1.2083 × 10 ^-4
A ₆ = 1.1516 × 10 ^-7
A ₈ = -2.9381 × 10 ^-8
A ₁₀ = 0.0000
16th surface K = 0
A ₄ = 1.3137 × 10 ^-3
A ₆ = -2.0878 × 10 ^-5
A ₈ = 4.9397 × 10 ^-7
A ₁₀ = 0.0000
Zoom data (∞)
WE ST TE
f (mm) 5.02898 8.69474 14.52092
F _NO 2.6544 3.5217 4.5079
2ω (°) 64.0 40.8 24.2
d ₆ 14.61860 7.39251 1.80000
d ₁₂ 3.75585 8.20107 4.39975
d ₁₄ 3.16733 5.96897 15.38987.

Aberration diagrams at the time of focusing on an object point at infinity in Examples 1 to 4 are shown in FIGS. In these aberration diagrams, (a) shows the wide-angle end, (b) the intermediate state, and (c) spherical aberration SA, astigmatism AS, distortion DT, and lateral chromatic aberration CC at the telephoto end. In the figure, “FIY” represents the image height.

Next, the distinction between the zoom types a to d in the above-described embodiments and the values of a, t _LPF and L relating to the values of the conditions (1) to (31 and the condition (32) are shown.

Example 1 Example 2 Example 3 Example 4 Example 5
Zoom type a d c b b
(1) 1.38822 1.41072 1.37082 1.45054 1.37212
(2) 1.66024 2.28107 2.01027 1.74028 1.58543
(3) 1.67612 1.52529 1.29028 1.28997 1.18812
(4), (4C) 0.34947 *** *** *** ***
(5), (5C), -0.48666 *** -1.00064 *** ***
(10), (10C) (6), (6C), 27.79 *** 33.07 *** ***
(11), (11C) (7), (7C) -0.61816 *** *** *** ***
(8), (8C), -0.72084 0.25142 0.21762 0.44850 0.53142
(13), (13C), (18), (18C) (9), (9C),
*** 0.73100 0.73030 0.89173 0.88437
(14), (14C) (12), (12C), *** -3.12101 -0.79692 -0.31222 -0.47931
(17), (17C)
(15), (15C) *** 1.35184 *** 0.81112 0.73000
(16), (16C) *** 29.43 *** 25.56 25.56
(19) 0.40806 0.48761 0.38280 0.40516 0.44149
(20) 0.21992 0.15218 0.10734 0.14176 -0.11046
(21) 0.70097 0.57446 0.67059 0.57052 0.60231
(22) 0.27038 0.27052 0.27044 0.27032 0.27034
(23) 1.41223 1.42456 1.42456 1.39716 1.39716
(24) 1.78590 1.78590 1.78590 1.78590 1.78592
(25) -0.19814 -0.14934 -0.16882 -0.12548 -0.14612
(26) 0.62425 0.43029 0.50182 0.35540 0.41694
(27) 1.11933 1.10145 1.13322 1.07061 1.13215
(28) 1.0 1.0 1.0 1.0 1.0
(29) 0.04 0.04 0.04 0.04 0.04
(30) 0.0 0.0 0.0 0.0 0.0
(31) 1.06 1.06 1.06 1.06 1.06
a 3.5 3.9 3.7 2.9 2.5
t _LPF 0.55 0.58 0.52 0.38 0.30
L 7.30 7.30 7.30 7.30 7.30
.

Example 6 Example 7 Example 8 Example 9 Example 10
Zoom type b b b a b
(1) 1.36326 1.30842 1.37622 1.49634 1.15970
(2) 1.57780 1.51202 1.57269 1.88643 1.47797
(3) 1.16490 1.13951 1.14667 3.68738 1.41403
(4), (4C) *** *** *** 0.49409 ***
(5), (5C), *** *** *** 0.00000 ***
(10), (10C) (6), (6C), *** *** *** 24.04 ***
(11), (11C) (7), (7C) *** *** *** -0.72854 ***
(8), (8C), 0.51417 0.56419 0.52960 -0.42385 0.46600
(13), (13C), (18), (18C) (9), (9C),
0.91188 0.91652 0.93112 *** 0.93549
(14), (14C) (12), (12C), -0.24544 -0.31721 -0.31127 *** 0.16632
(17), (17C)
(15), (15C) 0.66364 0.56154 0.56154 *** 0.69524
(16), (16C) 25.56 25.56 25.56 *** 25.56
(19) 0.43615 0.40132 0.40923 0.40737 0.54841
(20) 0.10368 0.09281 0.09173 0.26966 0.17155
(21) 0.60543 0.63420 0.63699 0.67986 0.49871
(22) 0.27030 0.27035 0.27038 0.27043 0.27026
(23) 1.39716 1.39716 1.39716 1.36976 1.385301
(24) 1.78590 1.78590 1.78590 1.78590 1.83481
(25) -0.14430 -0.16362 -0.13904 -0.20851 -0.23197
(26) 0.40879 0.47549 0.39515 0.78065 0.79956
(27) 1.13895 1.18742 1.12882 1.03909 1.49131
(28) 1.0 1.0 1.0 1.0 1.0
(29) 0.04 0.04 0.04 0.04 0.04
(30) 0.0 0.0 0.0 0.0 0.0
(31) 1.06 1.06 1.06 1.06 1.06
a 2.8 2.7 2.6 3.3 3.1
t _LPF 0.25 0.25 0.26 0.24 0.25
L 7.30 7.30 7.30 7.30 7.30
.

Example 11 Example 12 Example 13
Zoom type b b a
(1) 1.12846 1.06460 1.24661
(2) 1.43635 1.43051 1.49969
(3) 1.50110 1.23503 5.68083
(4), (4C) *** *** 0.80815
(5), (5C), *** *** 0.21853
(10), (10C) (6), (6C), *** *** 39.55
(11), (11C) (7), (7C) *** *** 0.39089
(8), (8C), 0.44082 0.56189 0.11923
(13), (13C), (18), (18C) (9), (9C), 1.04989 0.90164 ***
(14), (14C) (12), (12C), 0.78258 -0.31328 ***
(17), (17C)
(15), (15C) 0.44242 0.41684 ***
(16), (16C) 25.56 25.56 ***
(19) 0.52310 0.13339 0.30301
(20) 0.19211 0.07549 0.24793
(21) 0.50649 0.97637 0.95350
(22) 0.10425 0.11002 0.32739
(23) 1.40014 1.39808 1.20313
(24) 1.80610 1.7725 1.50913
(25) -0.35720 -0.20746 0.27111
(26) 1.94314 0.59664 1.26698 *
(27) 1.53460 1.62493 1.36309
(28) 1.0 1.0 1.0
(29) 0.04 0.04 0.04
(30) 0.0 0.0 0.0
(31) 1.06 1.06 1.06
a 2.8 1.85 2.5
t _LPF 0.25 0 1.20
L 7.30 3.96 6.0
*: F ₁₁ when the incident surface of the prism has refractive power is the focal length from the most object-side surface to the exit surface of the prism.

In addition, since the optical low-pass filter in the numerical data of Examples 1 to 13 has a structure of a plurality of sheets and further includes the thickness of an infrared cut filter or the like, the maximum thickness is not the value of t _LPF but in the above table. The value of t _LPF is used.

  Here, the diagonal length L and the pixel interval a of the effective imaging surface of the electronic imaging device will be described. FIG. 19 is a diagram illustrating an example of a pixel array of an electronic imaging device, and R (red), G (green), and B (blue) pixels or cyan, magenta, yellow, and green (green) at a pixel interval a. The four color pixels (FIG. 22) are arranged in a mosaic pattern. The effective image pickup surface means a region in the photoelectric conversion surface on the image pickup element used for reproduction (display on a personal computer, printing by a printer, etc.) of a taken image. The effective image pickup surface shown in the figure is set to a region narrower than the entire photoelectric conversion surface of the image pickup device in accordance with the performance of the optical system (image circle that can ensure the performance of the optical system). The diagonal length L of the effective imaging surface is the diagonal length of this effective imaging surface. Note that the imaging range used for video reproduction may be variously changed. However, when the zoom lens of the present invention is used in an imaging apparatus having such a function, the diagonal length L of the effective imaging surface changes. In such a case, the diagonal length L of the effective imaging surface in the present invention is the maximum value in the range that L can take.

  In each of the above embodiments, the image side of the final lens group has an optical low-pass filter LF having a near-infrared cut filter or a near-infrared cut coat surface on the incident surface side. The near-infrared cut filter and near-infrared cut coat surface are configured such that the transmittance at a wavelength of 600 nm is 80% or more and the transmittance at a wavelength of 700 nm is 10% or less. Specifically, it is a multilayer film composed of the following 27 layers, for example. However, the design wavelength is 780 nm.

Substrate material Physical film thickness (nm) λ / 4
───────────────────────────────
First layer Al ₂ O ₃ 58.96 0.50
Second layer TiO ₂ 84.19 1.00
Third layer SiO ₂ 134.14 1.00
Fourth layer TiO ₂ 84.19 1.00
5th layer SiO ₂ 134.14 1.00
Sixth layer TiO ₂ 84.19 1.00
Seventh layer SiO ₂ 134.14 1.00
Eighth layer TiO ₂ 84.19 1.00
Ninth layer SiO ₂ 134.14 1.00
10th layer TiO ₂ 84.19 1.00
11th layer SiO ₂ 134.14 1.00
12th layer TiO ₂ 84.19 1.00
13th layer SiO ₂ 134.14 1.00
14th layer TiO ₂ 84.19 1.00
15th layer SiO ₂ 178.41 1.33
16th layer TiO ₂ 101.03 1.21
17th layer SiO ₂ 167.67 1.25
18th layer TiO ₂ 96.82 1.15
19th layer SiO ₂ 147.55 1.05
20th layer TiO ₂ 84.19 1.00
21st layer SiO ₂ 160.97 1.20
22nd layer TiO ₂ 84.19 1.00
23rd layer SiO ₂ 154.26 1.15
24th layer TiO ₂ 95.13 1.13
25th layer SiO ₂ 160.97 1.20
26th layer TiO ₂ 99.34 1.18
27th layer SiO ₂ 87.19 0.65
───────────────────────────────
Air.

  The transmittance characteristics of the near infrared sharp cut coat are as shown in FIG. Further, the color reproducibility of the electronic image is further improved by providing or coating a color filter that reduces the transmission of colors in the short wavelength region as shown in FIG. 21 on the emission surface side of the low-pass filter LF. ing.

  Specifically, with this filter or coating, the ratio of the transmittance of the wavelength of 420 nm to the transmittance of the wavelength having the highest transmittance at a wavelength of 400 nm to 700 nm is 15% or more, and 400 nm to the transmittance of the highest wavelength. It is preferable that the ratio of the transmittances of the wavelengths is 6% or less.

  Thereby, it is possible to reduce the difference between the recognition of the color of the human eye and the color of the image to be captured and reproduced. In other words, it is possible to prevent deterioration of the image due to the human eye easily recognizing a short wavelength color that is difficult to be recognized by human vision.

  If the ratio of the transmittance at the wavelength of 400 nm exceeds 6%, the single wavelength castle which is difficult to be recognized by the human eye is regenerated to a recognizable wavelength. If the ratio is less than 15%, the reproduction of wavelength castles that can be recognized by humans becomes low, and the color balance becomes poor.

  Such means for limiting the wavelength is more effective in an imaging system using a complementary color mosaic filter.

  In each of the above embodiments, as shown in FIG. 21, the coating has a transmittance of 0% at a wavelength of 400 nm, a transmittance of 90% at 420 nm, and a transmittance peak of 100% at 440 nm.

  By multiplying the action with the above-mentioned near infrared sharp cut coat, the transmittance at 400 nm is peaked at 99%, the transmittance at 400 nm is 0%, the transmittance at 420 nm is 80%, and the transmittance at 600 nm is 82%. The transmittance at 700 nm is 2%. As a result, more faithful color reproduction is performed.

  In addition, the low-pass filter LF uses three types of filters having crystal axes in the horizontal (= 0 °) and ± 45 ° directions when projected on the image plane in the optical axis direction, respectively. In this case, moire suppression is performed by shifting by SQRT (1/2) × a horizontally in the direction of a μm and ± 45 °. Here, SQRT is a square route and means a square root as described above.

  Further, as shown in FIG. 22, a complementary color mosaic filter in which four color filters of cyan, magenta, yellow and green (green) are provided in a mosaic pattern corresponding to the imaging pixels is provided on the imaging surface I of the CCD. ing. These four types of color filters are arranged in a mosaic so that each of them has approximately the same number and adjacent pixels do not correspond to the same type of color filter. Thereby, more faithful color reproduction becomes possible.

  Specifically, the complementary color mosaic filter is composed of at least four types of color filters as shown in FIG. 22, and the characteristics of the four types of color filters are preferably as follows.

The green color filter G has a spectral intensity peak at the wavelength _GP ,
Yellow filter element Y _e has a spectral strength peak at a wavelength Y _P,
Each cyan filter element C has a spectral strength peak at a wavelength C _P,
The magenta color filter M has peaks at wavelengths M _P1 and M _P2 and satisfies the following conditions.

510 nm <G _P <540 nm
5 nm <Y _P −G _P <35 nm
−100 nm <C _P −G _P <−5 nm
430 nm <M _P1 <480 nm
580 nm <M _P2 <640 nm
Further, the green, yellow, and cyan color filters have an intensity of 80% or more at a wavelength of 530 nm with respect to each spectral intensity peak, and the magenta color filter has an intensity of 10% at a wavelength of 530 nm. From the viewpoint of improving the color reproducibility, it is more preferable that the strength is 50% to 50%.

An example of each wavelength characteristic in each of the above embodiments is shown in FIG. The green color filter G has a spectral intensity beak at 525 nm. The yellow color filter Y _e has a spectral intensity peak at 555 nm. The cyan color filter C has a spectral intensity peak at 510 nm. The magenta color filter M has peaks at 445 nm and 620 nm. In each color filter at 530 nm, G is 99%, _Ye is 95%, C is 97%, and M is 38% with respect to the respective spectral intensity peaks.

In the case of such a complementary color filter, the following signal processing is performed electrically with a controller (not shown) (or a controller used in a digital camera),
Luminance signal Y = | G + M + Y _e + C | × 1/4
Color signal R−Y = | (M + Y _e ) − (G + C) |
B−Y = | (M + C) − (G + Y _e ) |
The signal is converted into R (red), G (green), and B (blue) signals.

  By the way, the arrangement position of the above-mentioned near infrared sharp cut coat may be any position on the optical path. Further, the number of low-pass filters LF may be two or one as described above.

  FIG. 24 shows details of the aperture stop portion of each embodiment. However, this figure shows a case of a four-group configuration, and the optical path bending prism P in the first group G1 is omitted. Brightness can be adjusted in 0, −1, −2, −3, and −4 steps at the stop position on the optical axis between the first group G1 and the second group G2 of the imaging optical system. A turret 10 is arranged. The turret 10 has an opening 1A having a circular shape with a diameter of about 4 mm and a fixed space (the transmittance for a wavelength of 550 nm is 100%), and the opening of the opening 1A for −1 correction. An opening 1B made of a transparent parallel plate having a fixed opening shape having an opening area that is about half the area (the transmittance for the wavelength of 550 nm is 99%), a circular opening having the same area as the opening 1B, and −2 steps In order to correct to -3 and -4 stages, apertures 1C, 1D, and 1E provided with ND filters having transmittances of 50%, 25%, and 13% for a wavelength of 550 nm, respectively, are provided.

  The amount of light is adjusted by arranging one of the openings at the aperture position by turning the turret 10 around the rotation shaft 11.

Further, when the effective F number F _no ′ satisfies F _no ′> a / 0.4 μm, an ND filter having a transmittance of less than 80% for a wavelength of 550 nm is arranged in the opening. Specifically, in the first embodiment, the effective F value at the telephoto end satisfies the above equation when the effective F value, which is -2 steps with respect to the full aperture (0 steps), is 9.0. There is a corresponding opening of 1C. This suppresses image degradation due to the diffraction phenomenon of the stop.

  An example in which the turret 10 'shown in FIG. 25A is used instead of the turret 10 shown in FIG. Adjust the brightness of the 0th, -1st, -2nd, -3rd, and -4th steps to the aperture stop position on the optical axis between the first group G1 and the second group G2 of the imaging optical system. The possible turret 10 'is arranged. The turret 10 'has an opening shape with an opening of about 4 mm in diameter, which is adjusted in zero steps, and a fixed opening 1A' having a diameter of about 4 mm, and an opening area which is about half of the opening area of the opening 1A 'in order to correct -1 step. The aperture 1B ′ having a fixed shape and the aperture area are further reduced in order, and the apertures 1C ′, 1D ′, and 1E ′ having fixed shapes for correcting to −2, 3 and 4 steps are provided. is doing. The amount of light is adjusted by arranging one of the openings at the stop position by turning the turret 10 ′ around the rotation shaft 11.

  Further, optical low-pass filters having different spatial frequency characteristics are arranged from 1A ′ to 1D ′ in the plurality of openings. Then, as shown in FIG. 25B, the spatial frequency characteristic of the optical filter is set higher as the aperture diameter becomes smaller, thereby suppressing image deterioration due to diffraction phenomenon due to narrowing down. Each curve in FIG. 25B shows the spatial frequency characteristics of only the low-pass filter, and the characteristics including diffraction of each diaphragm are set to be equal.

  The electronic image pickup apparatus of the present invention as described above is an image pickup apparatus that forms an object image with an imaging optical system such as a zoom lens and receives the image on an image pickup device such as a CCD or a silver salt film, and performs shooting. It can be used for a digital camera, a video camera, a personal computer which is an example of an information processing apparatus, a telephone, particularly a mobile phone which is convenient to carry. The embodiment is illustrated below.

  FIG. 26 to FIG. 28 are conceptual diagrams of structures in which the imaging optical system according to the present invention is incorporated in the photographing optical system 41 of the digital camera. 26 is a front perspective view showing the appearance of the digital camera 40, FIG. 27 is a rear perspective view thereof, and FIG. 28 is a cross-sectional view showing the 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. When the shutter 45 disposed in the position is pressed, photographing is performed through the photographing optical system 41, for example, the optical path bending zoom lens of the first embodiment in conjunction therewith. An object image formed by the photographing optical system 41 is formed on the imaging surface of the CCD 49 via a near-infrared cut filter and an optical low-pass filter LF. The object image received by the CCD 49 is displayed as an electronic image on the liquid crystal display monitor 47 provided on the back of the camera via the processing means 51. Further, the processing means 51 is connected to a recording means 52 so that a photographed electronic image can be recorded. The recording means 52 may be provided separately from the processing means 51, or may be configured to perform recording / writing electronically using a floppy disk, memory card, MO, or the like. Further, it may be configured as a silver salt camera in which a silver salt film is arranged in place of the CCD 49.

  Further, a finder objective optical system 53 is disposed on the finder optical path 44. The object image formed by the finder objective optical system 53 is formed on the field frame 57 of the Porro prism 55 which is an image erecting member. Behind this polyprism 55 is an eyepiece optical system 59 that guides the erect image to the observer eyeball E. Note that cover members 50 are disposed on the incident side of the photographing optical system 41 and the finder objective optical system 53 and on the exit side of the eyepiece optical system 59, respectively.

  The digital camera 40 configured in this manner is a zoom lens with a large back focus, a photographing optical system 41 having a wide angle of view and a high zoom ratio, good aberration, bright, and a filter that can be arranged with a high back focus. Performance and cost reduction can be realized.

  In the example of FIG. 28, a parallel plane plate is disposed as the cover member 50, but a lens having power may be used.

  Next, a personal computer which is an example of an information processing apparatus in which the imaging optical system of the present invention is built as an objective optical system is shown in FIGS. 29 is a front perspective view with the cover of the personal computer 300 opened, FIG. 30 is a sectional view of the photographing optical system 303 of the personal computer 300, and FIG. 31 is a side view of the state of FIG. As shown in FIGS. 29 to 31, the personal computer 300 includes a keyboard 301 for a writer to input information from the outside, information processing means and recording means (not shown), and a monitor for displaying information to the operator. 302 and a photographing optical system 303 for photographing the operator himself and surrounding images. Here, the monitor 302 may be a transmissive liquid crystal display element that is illuminated from the back by a backlight (not shown), a reflective liquid crystal display element that reflects and displays light from the front, a CRT display, or the like. 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 has an objective lens 112 made up of, for example, an optical path bending zoom lens according to the first embodiment of the present invention and an image sensor chip 162 that receives an image on a photographing optical path 304. These are built in the personal computer 300.

Here, an optical low-pass filter LF is additionally attached on the image pickup device chip 162 to be integrally formed as an image pickup unit 160, and can be fitted and attached to the rear end of the lens frame 113 of the objective lens 112 with one touch. Therefore, the center alignment of the objective lens 112 and the image sensor chip 162 and the adjustment of the surface interval are unnecessary, and the assembly is simple.
Further, a cover glass 114 for protecting the objective lens 112 is disposed at the tip (not shown) of the lens frame 113. The zoom lens driving mechanism and the like in the lens frame 113 are not shown.

  The object image received by the image sensor chip 162 is input to the processing means of the personal computer 300 via the terminal 166 and is displayed on the monitor 302 as an electronic image. FIG. A rendered image 305 is shown. The image 305 can also be displayed on the personal computer of the communication partner from a remote location via the processing means, the Internet, or the telephone.

  Next, FIG. 32 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 that is convenient to carry. 32A is a front view of the mobile phone 400, FIG. 32B is a side view, and FIG. 32C is a sectional view of the photographing optical system 405. As shown in FIGS. 32A to 32C, the mobile phone 400 includes a microphone unit 401 that inputs an operator's voice as information, a speaker unit 402 that outputs the voice of the other party, and an operator who receives information. An input dial 403 for inputting information, a monitor 404 for displaying information such as a photographed image and a telephone number of the operator and the other party, a photographing optical system 405, an antenna 406 for transmitting and receiving communication radio waves, and an image And processing means (not shown) for processing 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 photographic optical system 405 includes an objective lens 112 including, for example, an optical path bending zoom lens according to the first embodiment of the present invention disposed on a photographic optical path 407, and an image sensor chip 162 that receives an object image. These are built in the mobile phone 400.

  Here, an optical low-pass filter LF is additionally attached on the image sensor chip 162 to be integrally formed as an image pickup unit 160, and can be fitted and attached to the rear end of the lens frame 113 of the objective lens 112 with one touch. Therefore, the center alignment of the objective lens 112 and the image sensor chip 162 and the adjustment of the surface interval are unnecessary, and the assembly is simple. Further, a cover glass 114 for protecting the objective lens 112 is disposed at the tip (not shown) of the lens frame 113. The zoom lens driving mechanism and the like in the lens frame 113 are not shown.

  The object image received by the imaging element chip 162 is input to the processing means (not shown) via the terminal 166 and displayed as an electronic image on the monitor 404, the monitor of the communication partner, or both. . Further, when transmitting an image to a communication partner, the processing means includes a signal processing function for converting information of an object image received by the image sensor chip 162 into a signal that can be transmitted.

  The zoom lens of the present invention and the electronic image pickup apparatus using the zoom lens can be configured as follows, for example.

[1] A moving lens group B that has a positive refractive power and moves only to the object side when zooming from the wide-angle end to the telephoto end, and is disposed closer to the object side than the moving lens group B, and has a negative refraction. A variable power lens unit A that is fixed at the time of zooming,
The moving lens group B is composed of three lenses of a positive lens, a positive lens, and a negative lens in order from the object side.

    [2] The zoom lens according to [1], wherein the negative lens in the moving lens group B is cemented with the positive lens adjacent to the object side.

[3] A moving lens group B that has a positive refractive power and moves only to the object side when zooming from the wide-angle end to the telephoto end; A variable power lens unit A that is fixed at the time of zooming,
The moving lens group B is composed of three lenses of a positive lens, a negative lens, and a positive lens in order from the object side.

    [4] The zoom lens according to [3], wherein the negative lens in the moving lens group B is cemented with the positive lens adjacent to the object side or the image side.

    [5] The zoom lens according to any one of 1 to 4, further comprising a third lens group C on the image side of the moving lens group B with a variable air gap.

[6] A moving lens group B that has a positive refractive power and moves only to the object side when zooming from the wide-angle end to the telephoto end, and is disposed closer to the object side than the moving lens group B, and has a negative refraction. A variable power lens group A that is fixed at the time of zooming,
A third lens group C is disposed on the image side of the moving lens group B via a variable air gap, and the moving lens group B includes two lenses, a positive lens and a negative lens, The third lens group C is composed of three lenses in order from the object side: a positive lens, a positive lens, and a negative lens.

    [7] The zoom lens according to [6], wherein the negative lens of the third lens group C is cemented with the positive lens adjacent to the object side.

[8] A moving lens group B that has a positive refractive power and moves only to the object side when zooming from the wide-angle end to the telephoto end, and is disposed closer to the object side than the moving lens group B, and has a negative refraction. A variable power lens group A that is fixed at the time of zooming,
A third lens group C is disposed on the image side of the moving lens group B via a variable air gap, and the moving lens group B includes two lenses, a positive lens and a negative lens, The third lens group C is composed of three lenses in order from the object side: a positive lens, a negative lens, and a positive lens.

    [9] The zoom lens according to [8], wherein the negative lens in the moving lens group B is cemented with the positive lens adjacent to the object side or the image side.

    [10] Any one of 5 to 9 above, wherein the lens group that moves at the time of zooming or focusing is only two lens groups including the moving lens group B in the entire zoom lens. The zoom lens according to item 1.

    [11] The zoom lens according to any one of [5] to [10], wherein the third lens group C moves during a focusing operation.

    [12] The zoom lens according to any one of 5 to 11, wherein the third lens group C has a positive refractive power.

    [13] The zoom lens as described in any one of 5 to 12 above, further comprising a fourth lens group D having an aspheric surface on the image side with respect to the third lens group C.

    [14] The zoom lens according to [13], wherein the fourth lens group D is fixed at the time of zooming and focusing.

    [15] The zoom lens as described in any one of [1] to [14], wherein the zooming fixed lens group A includes a reflective optical element that bends the optical path.

    [16] The zoom lens as described in 15 above, wherein the reflecting optical element for bending the optical path is a prism.

    [17] The zoom lens as described in 16 above, wherein at least one of the transmission surfaces of the prism has a curvature.

    [18] The zoom lens according to [16] or [17], wherein the prism is disposed closest to the object side.

    [19] The zoom lens according to any one of [16] to [18], wherein the prism has an incident surface facing a concave surface toward the object side.

    [20] The zoom lens according to any one of [16] to [19], wherein an incident surface of the prism is an aspherical surface.

    [21] The zoom lens as described in any one of [16] to [20], wherein an exit surface of the prism is a flat surface.

    [22] The variable-power fixed lens group A includes, in order from the object side, an object-side subgroup A1 having a negative meniscus lens having a convex surface facing the object side, the image-side subgroup A2 including the reflective optical element, and a positive lens. 16. The zoom lens as described in 15 above, wherein

    [23] The fifteenth aspect, wherein the variable lens unit A during zooming includes a prism A1 that bends an optical path having a transmission surface with a concave surface facing the object side, and a subgroup A2 that includes at least a positive lens. Zoom lens.

    [24] The zoom lens according to any one of 1 to 23, wherein the following conditional expressions (1) and (2) are satisfied.

(1) 0.9 <−f _A / √ (f _W · f _T ) <2.0
(2) 1.0 <f _B / √ (f _W · f _T ) <3.0
Here, f _A and f _B are the focal lengths of the lens groups A and B, respectively, and f _W and f _T are the focal lengths of the wide-angle end and the telephoto end of the entire zoom lens system, respectively.

    [25] The zoom lens as described in 24 above, wherein the following conditional expression (3) is satisfied.

(3) 0.9 <log γ _B / log γ <10
Where γ and γ _B are
γ = f _T / f _W
γ _B = magnification of lens group B at the telephoto end / magnification of lens group B at the wide-angle end.

    [26] The zoom according to [2], wherein the moving lens group B includes, in order from the object side, an object side lens component that is the positive lens and an image side lens component that is the cemented cemented lens. lens.

[27] The zoom lens as described in 26 above, wherein the following conditional expression (4) is satisfied.

(4) 0.25 <R _22R / R _22F <0.95
Here, R _22F and R _22R are the curvature radii on the optical axis of the most object side surface and the most image side surface of the image side lens component of the lens group B, respectively.

    [28] An electronic imaging apparatus comprising the zoom lens according to 27 and an electronic imaging device disposed on an image side thereof, wherein the following conditional expressions (5) and (6) are satisfied:

(5) -1.0 <L / R _22C <0.8
(6) 14 <ν _22F −ν _22R
Where R _22C is the radius of curvature of the cemented surface of the image side lens component of the lens group B on the optical axis, L is the diagonal length of the effective imaging area of the electronic image sensor used, and ν _22F and ν _22R are the lens group B, respectively. The Abbe number with respect to the d-line of the medium of the positive lens and negative lens of the image side lens component.

    [29] The electronic imaging device as described in 28 above, wherein the wide-angle end field angle is 55 ° or more.

    [30] An electronic imaging apparatus comprising the zoom lens according to 27 and an electronic imaging device disposed on an image side thereof, wherein the following conditional expressions (7) and (8) are satisfied:

(7) −1.6 <(R _21F + R _21R ) / (R _21F −R _21R ) <1.2
(8) -1.2 <L / f _2R <0.1
Where R _21F and R _21R are the radius of curvature on the optical axis of the object side lens component of the moving lens group B on the optical axis, L is the diagonal length of the effective imaging area of the electronic image sensor, and f _2R Is the focal length of the image side lens component of the moving lens group B.

    [31] The zoom lens as described in 26 above, wherein the following conditional expression (9) is satisfied.

(9) 0.6 <R _21R / R _21F <1.0
However, R _21F and R _21R are radii of curvature in the vicinity of the optical axis of the object side surface and the image side surface of the object side lens component of the moving lens group B, respectively.

    [32] An electronic imaging apparatus comprising the zoom lens according to 31 and an electronic imaging device disposed on an image side thereof, wherein the following conditional expressions (10) and (11) are satisfied:

(10) -1.6 <L / R _22C <-0.4
(11) 20 <ν _22F −ν _22R
Where R _22C is the radius of curvature of the cemented surface of the image side lens component of the lens group B on the optical axis, L is the diagonal length of the effective imaging area of the electronic image sensor used, and ν _22F and ν _22R are the lens group B, respectively. The Abbe number with respect to the d-line of the medium of the positive lens and negative lens of the image side lens component.

    [33] The electronic imaging apparatus as described in 32 above, wherein the wide-angle end field angle is 55 ° or more.

    [34] An electronic imaging apparatus comprising the zoom lens according to 31 and an electronic imaging device disposed on an image side thereof, wherein the following conditional expressions (12) and (13) are satisfied:

(12) −1.5 <(R _22F + R _22R ) / (R _22F −R _22R ) <0.2
(13) 0.05 <L / f _2R <0.5
Where R _22F and R _22R are the most object-side surfaces of the image-side lens components of the lens group B, the radius of curvature on the optical axis of the most image-side surfaces, and L is the diagonal length of the effective imaging region of the electronic image sensor. f _2R is the focal length of the image side lens component of the moving lens unit B.

    [35] The zoom according to [7], wherein the third lens unit C includes, from the object side, an object side lens component that is the positive lens and an image side lens component that is the cemented cemented lens. lens.

    [36] The zoom lens as described in 35 above, wherein the following conditional expression (4C) is satisfied.

(4C) 0.25 <R _32R / R _32F <0.75
However, R _32F and R _32R are the curvature radii on the optical axis of the most object side surface and the most image side surface of the image side lens component of the third lens group C, respectively.

    [37] An electronic imaging apparatus comprising the zoom lens according to 36 and an electronic imaging device disposed on an image side thereof, wherein the following conditional expressions (5C) and (6C) are satisfied:

(5C) -1.0 <L / R _32C <0.6
(6C) 14 <ν _32F −ν _32R
Where R _32C is the radius of curvature of the cemented surface of the image side lens component of the third lens group C on the optical axis, L is the diagonal length of the effective imaging area of the electronic image sensor used, and ν _32F and ν _32R are respectively This is the Abbe number on the d-line basis of the medium of the positive lens and negative lens of the image side lens component of the third lens group C.

    [38] The electronic imaging device as described in 37 above, wherein the wide-angle end angle of view is 55 ° or more.

    [39] An electronic imaging apparatus comprising the zoom lens according to 36 and an electronic imaging device disposed on an image side thereof, wherein the following conditional expressions (7C) and (8C) are satisfied:

(7C) −1.6 <(R _31F + R _31R ) / (R _31F −R _31R ) <0.4
(8C) −1.2 <L / f _3R <−0.1
Here, R _31F and R _31R are the radius of curvature on the optical axis of the most object side surface and the most image side surface in the object side lens component of the third lens group C, respectively, L is the diagonal length of the effective imaging region of the electronic image sensor, f _3R is the focal length of the image side lens component of the third lens group C.

    [40] The zoom lens as described in 35 above, wherein the following conditional expression (9C) is satisfied.

(9C) 0.6 <R _31R / R _31F <1.0
However, R _31F and R _32R are the radii of curvature on the optical axis of the most object side surface and the most image side surface of the object side lens component of the third lens group C, respectively.

    [41] An electronic imaging apparatus comprising the zoom lens according to 40 and an electronic imaging device disposed on an image side thereof, wherein the following conditional expressions (10C) and (11C) are satisfied:

(10C) -1.6 <L / R _32C <-0.4
(11C) 20 <ν _32F −ν _32R
Where R _32C is the radius of curvature of the cemented surface of the image side lens component of the third lens group C on the optical axis, L is the diagonal length of the effective imaging area of the electronic image sensor used, and ν _32F and ν _32R are respectively This is the Abbe number on the d-line basis of the medium of the positive lens and negative lens of the image side lens component of the third lens group C.

    [42] The electronic imaging device as described in 41 above, wherein the wide angle end angle of view is 55 ° or more.

    [43] An electronic imaging apparatus comprising the zoom lens described in 40 above and an electronic imaging device disposed on the image side thereof, wherein the following conditional expressions (12C) and (13C) are satisfied:

(12C) −1.5 <(R _32F + R _32R ) / (R _32F −R _32R ) <0.2
(13C) 0.05 <L / f _3R <0.5
Where R _32F and R _32R are the most object side surface and the radius of curvature on the optical axis of the image side lens component of the third lens group C, L is the diagonal length of the effective imaging region of the electronic image sensor, f _3R is the focal length of the image side lens component of the third lens group C.

    [44] The moving lens group B includes, in order from the object side, an object side lens component that is the positive lens and an image side lens component that is the cemented cemented lens, or the cemented lens in order from the object side. 5. The zoom lens according to claim 4, comprising an object side lens component which is a cemented lens and an image side lens component which is the positive lens.

    [45] The zoom lens as described in 44 above, wherein the following conditional expression (14) is satisfied.

(14) 0.6 <R _21R / R _21F <1.2
Here, R _21F and R _21R are the radii of curvature on the optical axis of the most object side surface and the most image side surface in the object side lens component of the moving lens group B, respectively.

    [46] A zoom lens having the zoom lens according to 45 described above and an electronic image pickup device disposed on the image side thereof, wherein the object side lens component is the cemented lens, and the following conditional expressions (15), ( An electronic imaging device characterized by satisfying 16).

(15) 0.3 <L / R _21C <1.6
(16) 10 <ν _21F −ν _21R
Where R _21C is the radius of curvature on the optical axis of the cemented surface of the object side lens component of the moving lens group B, L is the diagonal length of the effective imaging area of the electronic image sensor, and ν _21F and ν _21R are the moving lens group B, respectively. The Abbe number on the d-line basis of the medium of the positive lens and the negative lens in the object side lens component.

    [47] The electronic imaging device as described in 46 above, wherein the wide angle end angle of view is 55 ° or more.

    [48] An electronic imaging apparatus comprising the zoom lens according to 45 and an electronic imaging device disposed on an image side thereof, wherein the following conditional expressions (17) and (18) are satisfied:

(17) −5.0 <(R _22F + R _22R ) / (R _22F −R _22R ) <0.7
(18) 0.1 <L / f _2R <1.0
Where R _22F and R _22R are the outermost object side surface and the radius of curvature on the optical axis of the image side lens component of the image side lens component of the moving lens group B, L is the diagonal length of the effective imaging region of the electronic image sensor, and f _2R Is the focal length of the image side lens component of the moving lens group B.

    [49] The third lens group C includes, in order from the object side, an object side lens component that is the positive lens and an image side lens component that is the cemented cemented lens, or sequentially from the object side. 10. The zoom lens according to claim 9, comprising an object side lens component that is the cemented cemented lens and an image side lens component that is the positive lens.

    [50] The zoom lens as described in 49 above, wherein the following conditional expression (14C) is satisfied.

(14C) 0.6 <R _31R / R _31F <1.2
Here, R _31F and R _31R are the radii of curvature on the optical axis of the most object side surface and the most image side surface in the object side lens component of the third lens group C, respectively.

    [51] A zoom lens having the zoom lens according to 49 described above and an electronic imaging device disposed on an image side thereof, wherein the object side lens component is the cemented lens, and the following conditional expressions (15C), ( 16C) is satisfied.

(15C) 0.3 <L / R _31C <1.6
(16C) 10 <ν _31F −ν _31R
Where R _31C is the radius of curvature on the optical axis of the cemented surface in the object side lens component of the third lens group C, L is the diagonal length of the effective imaging region of the electronic image sensor, and ν _31F and ν _31R are the third The Abbe number with respect to the d-line of the medium of the positive lens and the negative lens in the object side lens component of the lens group C.

    [52] The electronic imaging apparatus as described in 51 above, wherein the wide-angle end field angle is 55 ° or more.

    [53] An electronic imaging apparatus comprising the zoom lens according to 50, and an electronic imaging device disposed on an image side thereof, wherein the following conditional expressions (17C) and (18C) are satisfied:

(17C) −5.0 <(R _32F + R _32R ) / (R _32F −R _32R ) <0.7
(18C) 0.1 <L / f _3R <1.0
Where R _22F and R _22R are the most object side surface and the radius of curvature on the optical axis of the image side lens component of the third lens group C, respectively, L is the diagonal length of the effective imaging region of the electronic image sensor, f _3R is the focal length of the image side lens component of the third lens group C.

    [54] The zoom lens according to any one of [1] to [10], further including a lens group that performs a focusing operation by movement closer to the image side than the moving lens group B.

    [55] The zoom lens as described in 11 above, wherein the following condition (19) is satisfied.

(19) 0.1 <D _FT / f _T <1.0
Where D _FT is the air space on the optical axis from the moving lens group B to the third lens group C when focusing on an object point at infinity at the telephoto end, and f _T is when focusing on an object point at infinity at the telephoto end. This is the focal length of the entire zoom lens system.

    [56] An electronic imaging apparatus comprising: the zoom lens according to any one of 5 to 12 above; and an electronic imaging device disposed on an image side thereof, wherein the following conditional expression (20) is satisfied: .

(20) −0.4 <L / f _C <0.8
Here, f _C is the focal length of the third lens group C, and L is the diagonal length of the effective imaging area of the electronic imaging device.

    [57] The zoom lens as described in any one of 5 to 12 above, wherein the following condition (21) is satisfied.

(21) 0.0 <M ₃ / M ₂ <1.6
However, M ₂ and M ₃ are movement amounts at the telephoto end with respect to the wide-angle end when the moving lens unit B and the third lens unit C are focused on the object point at infinity, and the movement toward the image side is positive. To do.

    [58] An electronic imaging apparatus comprising the zoom lens described in item 13 or 14, and an electronic imaging element disposed on the image side thereof, wherein the following conditional expression (22) is satisfied.

(22) 0.0 <L / f _D <0.7
Here, f _D is the focal length of the fourth lens group D, and L is the diagonal length of the effective imaging area of the electronic imaging device.

    [59] A fourth lens group comprising the zoom lens according to any one of 5 to 12 above and an electronic image pickup device disposed on the image side, wherein the zoom lens satisfies the following conditional expression (22): An electronic imaging apparatus characterized in that D is arranged closer to the image side than the third lens group C.

(22) 0.0 <L / f _D <0.7
Here, f _D is the focal length of the fourth lens group D, and L is the diagonal length of the effective imaging area of the electronic imaging device.

    [60] The reflection optical element for reflecting, which bends the optical path on the object side, is disposed on all the lens groups that move during zooming or focusing operation. Zoom lens.

    [61] The zoom lens according to any one of [1] to [15], wherein the lens group A fixed at the time of zooming is positioned closest to the object side in the zoom lens.

    [62] The fifteenth or sixty-first aspect described above, wherein the zooming fixed lens group A includes, in order from the object side, an object side sub group A1, the reflective optical element, and an image side sub group A2. Zoom lens.

    [63] An electronic imaging apparatus comprising the zoom lens according to any one of the above 22 or 62 and an electronic imaging device disposed on an image side thereof, wherein the following conditional expression (23) is satisfied: .

(23) 0.8 <d / L <2.0
Where d is the air-converted length from the refractive surface having the refractive power immediately before the reflecting surface of the reflecting optical element in the lens group A fixed at the time of zooming to the refractive surface having the refractive power immediately after the reflecting surface, and L is the electronic imaging. It is the diagonal length of the effective imaging area of the element.

    [64] The angle of view in the direction of the plane including the incident optical axis incident on the reflective surface of the reflective optical element and the reflected optical axis after reflection is 22 ° to 28 °, and the following condition (23-1) 64. The electronic imaging device as described in 63 above, wherein:

(23-1) 1.1 <d / L <1.7
[65] The angle of view in the direction of the plane including the incident optical axis incident on the reflective surface of the reflective optical element and the reflected optical axis after reflection is 16 ° to 22 °, and the following condition (23-2) 64. The electronic imaging device as described in 63 above, wherein:

(23-2) 1.2 <d / L <1.8
[66] The zoom lens as described in any one of [15], [22], [60] and [62], wherein the reflective optical element is constituted by a prism which satisfies the following condition (24).

(24) 1.5 <n _pri
Here, n _pri is the refractive index of the medium with respect to the d-line of the prism.

    [67] The electronic imaging apparatus as described in any one of [63], [64], [65], wherein the reflective optical element is constituted by a prism that satisfies the following condition (24).

(24) 1.5 <n _pri
Here, n _pri is the refractive index of the medium with respect to the d-line of the prism.

    [68] Any one of the above 22 or 62, wherein the image side subgroup A2 in the zooming fixed lens group A is composed of two lenses of a negative lens and a positive lens in order from the object side. The described zoom lens.

    [69] The zoom lens according to any one of the above items 22, 62, and 68 and an electronic imaging device disposed on an image side thereof, wherein the zoom lens satisfies the following conditional expression (25): An electronic imaging device.

(25) −0.5 <L / f ₁₂ <0
Here, L is the diagonal length of the effective image pickup area of the electronic image pickup device, and f ₁₂ is the focal length of the image side subgroup A2 of the fixed lens group A during zooming.

    [70] The zoom lens according to [22] or [62], wherein the object side sub group A1 of the zooming fixed lens group includes only one negative lens having a convex surface directed toward the object side.

    [71] The zoom lens according to [70], wherein the following conditional expression (26) is satisfied.

(26) 0 <f ₁₁ / f ₁₂ <1.6
Here, f ₁₁ and f ₁₂ are the focal lengths of the object side sub group A1 and the image side sub group A2 of the fixed lens group A during zooming, respectively.

    [72] The zoom lens as described in [5] above, wherein the third lens group C comprises one single lens.

    [73] The zoom lens according to any one of [1] to [22], wherein the third lens unit C moves toward the image side at a telephoto end rather than at a wide angle end.

    [74] The zoom lens as described in 73 above, wherein the following conditional expression (27) is satisfied.

(27) 0.8 <−β _Rt <2.1
Here, β _Rt is the combined magnification after the moving lens group B at the telephoto end when focusing on an object point at infinity.

    [75] The zoom lens according to any one of 1 to 27, 31, 35, 36, 40, 44, 48, 49, 50, 54, 55, 57, 60 to 62, 66, 68, 70 to 74 And an electronic imaging device provided on the image side.

  As described above, according to the present invention, it is possible to insert a reflective optical element such as a mirror on the object side as much as possible to bend the optical path (optical axis) of the optical system, particularly the zoom lens system, and to make various zooms. While ensuring high optical performance such as ratio, wide angle of view, small F-number, and low aberration, there is no startup time (lens protruding time) to use the camera as seen in a retractable lens barrel. Also, it is preferable in terms of waterproofing and dustproofing, and it becomes possible to make the camera in a very thin depth direction.

G1-1 ... G1-1 lens group G1-2 ... G1-2 lens group G1 ... first lens group G2 ... second lens group G3 ... third lens group G4 ... fourth lens group P ... optical path bending prism S ... opening Aperture IC ... Near-infrared cut coat surface LF ... Optical low-pass filter CG ... Cover glass I ... Image plane E ... Observer eye 1A, 1B, 1C, 1D, 1E ... Aperture 1A ', 1B', 1C ', 1D' 1E '... aperture 10 ... turret 10' ... turret 11 ... rotating shaft 40 ... digital camera 41 ... photographic optical system 42 ... photographic optical path 43 ... finder optical system 44 ... finder optical path 45 ... shutter 46 ... flash 47 ... liquid crystal display Monitor 49 ... CCD
DESCRIPTION OF SYMBOLS 50 ... Cover member 51 ... Processing means 52 ... Recording means 53 ... Finder objective optical system 55 ... Porro prism 57 ... Field frame 59 ... Eyepiece optical system 112 ... Objective lens 113 ... Lens frame 114 ... Cover glass 160 ... Imaging unit 162 ... Image sensor chip 166 ... Terminal 300 ... Personal computer 301 ... Keyboard 302 ... Monitor 303 ... Shooting optical system 304 ... Shooting optical path 305 ... Image 400 ... Mobile phone 401 ... Microphone unit 402 ... Speaker unit 403 ... Input dial 404 ... Monitor 405 ... Shooting optics System 406 ... Antenna 407 ... Imaging optical path

Claims (31)

Moving lens group B that has a positive refractive power and moves only to the object side when zooming from the wide-angle end to the telephoto end, and is disposed closer to the object side than the moving lens group B, and has a negative refractive power. The zooming-fixed lens group A that is fixed when zooming, the third lens group C that is arranged on the image side of the moving lens group B via a variable air gap, and the third lens group A fourth lens unit D having an aspheric surface disposed on the image side of C,
The moving lens group B is composed of three lenses of a positive lens, a negative lens, and a positive lens in order from the object side.
The fourth lens group D is fixed at the time of zooming and focusing,
When zooming from the wide-angle end to the telephoto end, the lens unit B and the lens unit C move to the object side at the telephoto end rather than the wide-angle end while changing the relative distance.
A zoom lens characterized by satisfying the following condition (21) "' .
(21) "'0.0 <M ₃ / M ₂ ≦ 0.97637
However, M ₂ and M ₃ are movement amounts at the telephoto end with respect to the wide-angle end when the moving lens unit B and the third lens unit C are focused on the object point at infinity, and the movement toward the image side is positive. To do. The zoom lens according to claim 1, wherein the negative lens in the moving lens group B is cemented with the positive lens adjacent to the object side or the image side. The zoom lens according to claim 1, wherein the third lens group C moves during a focusing operation. The zoom lens according to any one of claims 1 to 3, wherein the third lens group C has a positive refractive power. 5. The zoom lens according to claim 1, wherein the zooming fixed lens group A includes a reflective optical element that bends the optical path. 6. 6. The zoom lens according to claim 5, wherein the reflecting optical element that bends the optical path is a prism. The zoom lens according to claim 6, wherein an exit surface of the prism is a flat surface. The zooming fixed lens group A includes, in order from the object side, an object side subgroup A1 having a negative meniscus lens having a convex surface facing the object side, and an image side subgroup A2 including the reflective optical element and a positive lens. The zoom lens according to claim 5. The zoom lens according to any one of claims 1 to 8, wherein the following conditional expressions (1) and (2) are satisfied.
(1) 0.9 <−f _A / √ (f _W · f _T ) <2.0
(2) 1.0 <f _B / √ (f _W · f _T ) <3.0
Here, f _A and f _B are the focal lengths of the lens groups A and B, respectively, and f _W and f _T are the focal lengths of the wide-angle end and the telephoto end of the entire zoom lens system, respectively. The zoom lens according to claim 9, wherein the following conditional expression (3) is satisfied.
(3) 0.9 <log γ _B / log γ <10
Where γ and γ _B are
γ = f _T / f _W
γ _B = magnification of lens group B at the telephoto end / magnification of lens group B at the wide-angle end. The moving lens group B includes, in order from the object side, an object side lens component that is the positive lens and an image side lens component that is the cemented cemented lens, or the cemented junction in order from the object side. 3. The zoom lens according to claim 2, comprising an object side lens component which is a lens and an image side lens component which is the positive lens. The zoom lens according to claim 11, wherein the following conditional expression (14) is satisfied.
(14) 0.6 <R _21R / R _21F <1.2
Here, R _21F and R _21R are the radii of curvature on the optical axis of the most object side surface and the most image side surface in the object side lens component of the moving lens group B, respectively. A zoom lens according to claim 12, and an electronic imaging device disposed on the image side thereof, wherein the object side lens component is the cemented lens, and the following conditional expressions (15) and (16): An electronic imaging device characterized by satisfying
(15) 0.3 <L / R _21C <1.6
(16) 10 <ν _21F −ν _21R
Where R _21C is the radius of curvature on the optical axis of the cemented surface of the object side lens component of the moving lens group B, L is the diagonal length of the effective imaging area of the electronic image sensor, and ν _21F and ν _21R are the moving lens group B, respectively. The Abbe number on the d-line basis of the medium of the positive lens and the negative lens in the object side lens component. The electronic imaging apparatus according to claim 13, wherein the wide-angle end angle of view is 55 ° or more. 13. An electronic imaging apparatus comprising: the zoom lens according to claim 12; and an electronic imaging device disposed on an image side thereof, wherein the following conditional expressions (17) and (18) are satisfied.
(17) −5.0 <(R _22F + R _22R ) / (R _22F −R _22R ) <0.7
(18) 0.1 <L / f _2R <1.0
Where R _22F and R _22R are the outermost object side surface and the radius of curvature on the optical axis of the image side lens component of the image side lens component of the moving lens group B, L is the diagonal length of the effective imaging region of the electronic image sensor, and f _2R Is the focal length of the image side lens component of the moving lens group B. 4. The zoom lens according to claim 3, wherein the following condition (19) is satisfied.
(19) 0.1 <D _FT / f _T <1.0
Where D _FT is the air space on the optical axis from the moving lens group B to the third lens group C when focusing on an object point at infinity at the telephoto end, and f _T is when focusing on an object point at infinity at the telephoto end. This is the focal length of the entire zoom lens system. An electronic imaging apparatus comprising: the zoom lens according to claim 1; and an electronic imaging device disposed on an image side thereof, wherein the following conditional expression (20) is satisfied.
(20) −0.4 <L / f _C <0.8
Here, f _C is the focal length of the third lens group C, and L is the diagonal length of the effective imaging area of the electronic imaging device. An electronic imaging apparatus comprising: the zoom lens according to any one of claims 1 to 17; and an electronic imaging device arranged on an image side thereof, wherein the following conditional expression (22) is satisfied.
(22) 0.0 <L / f _D <0.7
Here, f _D is the focal length of the fourth lens group D, and L is the diagonal length of the effective imaging area of the electronic imaging device. 6. The zoom lens according to claim 5, wherein the zooming fixed lens group A includes, in order from the object side, an object side sub group A1, the reflective optical element, and an image side sub group A2. An electronic imaging apparatus comprising the zoom lens according to claim 8 and an electronic imaging device disposed on an image side thereof, wherein the following conditional expression (23) is satisfied:
(23) 0.8 <d / L <2.0
Where d is the air-converted length from the refractive surface having the refractive power immediately before the reflecting surface of the reflecting optical element in the lens group A fixed at the time of zooming to the refractive surface having the refractive power immediately after the reflecting surface, and L is the electronic imaging. It is the diagonal length of the effective imaging area of the element. The angle of view in the direction of the plane including the incident optical axis incident on the reflective surface of the reflective optical element and the reflected optical axis after reflection is 22 ° to 28 °, and satisfies the following condition (23-1) 21. The electronic imaging apparatus according to claim 20, wherein:
(23-1) 1.1 <d / L <1.7 The angle of view in the direction of the plane including the incident optical axis incident on the reflective surface of the reflective optical element and the reflected optical axis after reflection is 16 ° to 22 °, and satisfies the following condition (23-2) 21. The electronic imaging apparatus according to claim 20, wherein:
(23-2) 1.2 <d / L <1.8 20. The zoom lens according to claim 5, wherein the reflective optical element is constituted by a prism that satisfies the following condition (24).
(24) 1.5 <n _pri
Here, n _pri is the refractive index of the medium with respect to the d-line of the prism. The electronic imaging apparatus according to any one of claims 20, 21, and 22, wherein the reflective optical element is constituted by a prism that satisfies the following condition (24).
(24) 1.5 <n _pri
Here, n _pri is the refractive index of the medium with respect to the d-line of the prism. The zoom lens according to claim 8 or 19, wherein the image side subgroup A2 in the zooming fixed lens group A is composed of two lenses of a negative lens and a positive lens in order from the object side. A zoom lens according to any one of claims 8, 19 and 25, and an electronic imaging device arranged on the image side thereof, wherein the zoom lens satisfies the following conditional expression (25): Electronic imaging device.
(25) −0.5 <L / f ₁₂ <0
Here, L is the diagonal length of the effective image pickup area of the electronic image pickup device, and f ₁₂ is the focal length of the image side subgroup A2 of the fixed lens group A during zooming. The zoom lens according to claim 8 or 19, wherein the object side subgroup A1 of the zooming fixed lens group includes only one negative lens having a convex surface directed toward the object side. 28. The zoom lens according to claim 27, wherein the following conditional expression (26) is satisfied.
(26) 0 <f ₁₁ / f ₁₂ <1.6
Here, f ₁₁ and f ₁₂ are the focal lengths of the object side sub group A1 and the image side sub group A2 of the fixed lens group A during zooming, respectively. The zoom lens according to any one of claims 1 to 28, wherein the third lens group C includes one single lens. 30. A zoom lens according to claim 1, wherein the following conditional expression (27) is satisfied.
(27) 0.8 <−β _Rt <2.1
Here, β _Rt is the combined magnification after the moving lens group B at the telephoto end when focusing on an object point at infinity. An electronic imaging apparatus comprising: the zoom lens according to any one of claims 1 to 12, 16, 19, 23, 25, 27 to 30; and an electronic imaging device disposed on an image side thereof.

Images