JP2009265557A - Imaging optical system and electronic imaging apparatus having the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging optical system which is made thin in depth and short in an entire length though it has a high optical specification or performance such as a high zoom ratio, a wide viewing angle, a bright F value and satisfactorily corrected chromatic aberration. <P>SOLUTION: The imaging optical system has a first lens group G1 arranged most closely to an object side and having positive refractive power. The first lens group G1 has a catoptric element, and a lens component C1p arranged on the image side of the catoptric element and having positive refractive power. The lens component C1p is obtained by joining a negative lens LA and a positive lens LB, and the joined surface is aspherical. The imaging optical system satisfies a following expression (1). (1) 0.4<E/f12<2.0, where E is an air-conversion distance along an optical axis between a surface top Ct1 and a surface top Ct2, the surface top Ct1 is the surface top of a surface having the strongest negative refractive power of a refractive surface closer to the object side than the reflection surface of the catoptric element, the surface top Ct2 is the surface top of the joined surface of the lens component C1p, and f12 is the composite focal distance of all the lenses closer to the image side than the catoptric element out of the lenses constituting the first lens group G1. However, the composite focal distance is obtained when including an emitting surface, when the catoptric element has the emitting surface, and the emitting surface has refractive power. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an imaging optical system (zoom optical system) used for an imaging module and the like, and an electronic imaging apparatus having the imaging optical system.

  Digital cameras have achieved practical levels in terms of increasing the number of pixels (higher image quality) and reducing the size and thickness, and have been replaced by silver salt 35 mm film cameras, both functionally and commercially. Therefore, as one of the next evolution directions, there is a strong demand for further increase in the number of pixels as well as a high zoom ratio and a wide angle with the small size and thinness.

  As an imaging optical system that has been used so far as being strong in reducing the thickness of an optical system, for example, there is an optical system that uses a reflective optical element for bending an optical path from the object side to the first lens group. If such an imaging optical system is used, the depth of the camera housing can be extremely reduced (Patent Document 1 and Patent Document 2).

  In the optical systems of Patent Document 1 and Patent Document 2, the path of a light beam having a certain angle of view is reliably bent in the reflective optical element of the first lens group. In this case, the air equivalent thickness along the optical axis of the first lens group G1 is inevitably increased in order to secure a reflecting surface having a width required for the angle of view. In particular, when the angle is increased, an increase in the air equivalent thickness of this portion becomes remarkable. On the other hand, the thicker the air equivalent thickness, the wider the reflection surface is required.

  Therefore, in these optical systems, a negative refracting power is provided immediately before the reflecting surface, and a positive refracting power is provided immediately after the reflecting surface to reduce the width of the reflecting surface, and the air equivalent thickness is also reduced to some extent.

JP 2003-302576 A JP 2004-264343 A

However, by adopting such a configuration, the first lens group G1 necessarily has a reduction afocal converter. This lengthens the combined focal length of the subsequent optical system. As a result, the entire optical system becomes an imaging optical system having a long overall length. In particular, this becomes remarkable when the magnification is increased.
In order to reduce the overall length and thickness in such a state, it is necessary to increase both the positive and negative refractive powers before and after the reflecting surface. As a result, the secondary spectrum and the spherical aberration of the color are remarkably generated.

  An object of the present invention is to provide an imaging optical system in which chromatic aberration is corrected well, the depth is small, and the entire length is short, and an electronic imaging apparatus equipped with the imaging optical system.

In order to achieve the above object, an imaging optical system of the present invention is an imaging optical system including a first lens group G1 disposed on the most object side and having a positive refractive power, and the first lens group G1 includes a reflective optical element and a lens component C1p that is disposed on the image side of the reflective optical element and has a positive refractive power. The lens component C1p is formed by bonding a negative lens LA and a positive lens LB to each other. Is an aspherical surface and satisfies the following conditional expression (1).
0.4 <E / f12 <2.0 (1)
here,
E is the air equivalent distance along the optical axis between the top Ct1 and the top Ct2,
The surface top Ct1 is the surface top of the surface having the strongest negative refractive power among the refractive surfaces on the object side of the reflective surface of the reflective optical element,
Surface top Ct2 is the surface top of the cemented surface of the lens component C1p,
f12 is the combined focal length of all the lenses constituting the first lens group G1 that are closer to the image side than the reflective optical element. However, when the reflective optical element has an exit surface and the exit surface has a refractive power, it is a combined focal length when the exit surface is included.

The electronic imaging device of the present invention processes image data obtained by capturing an image formed through the imaging optical system, the electronic imaging element, and the imaging optical system with the electronic imaging element. Image processing means for outputting the image data with the shape of the image changed, and the imaging optical system is a zoom lens, and the zoom lens has the following conditional expression when focusing on an object point at infinity: (26) is satisfied.
0.7 <y ₀₇ / (fw · tan ω _07w ) <0.96 (26)
here,
y ₀₇ is expressed as y ₀₇ = 0.7y ₁₀ when the effective image pickup plane of the electronic imaging device the distance to the farthest point from the center in (imageable plane) (maximum image height) was y _10,
ω _07w is an angle with respect to the optical axis in the object point direction corresponding to the image point connecting from the center on the imaging surface to the position y ₀₇ at the wide-angle end.

  According to the present invention, it is possible to provide an imaging optical system in which chromatic aberration is corrected well, the depth is small, and the entire length is short, and an electronic imaging apparatus equipped with the imaging optical system.

  Prior to the description of the examples, the effects of the imaging optical system of the present embodiment will be described. In the following description, a positive (or positive refractive power) lens and a negative (or negative refractive power) lens refer to a lens whose paraxial focal length is a positive value and a negative value, respectively.

The imaging optical system of the present embodiment is an imaging optical system that includes a first lens group G1 that is disposed closest to the object side and has a positive refractive power. The first lens group G1 includes a reflective optical element, a reflective optical element, and a reflective optical element. The lens component C1p is disposed on the image side of the optical element and has a positive refractive power. The lens component C1p is formed by cementing a negative lens LA and a positive lens LB, and its cemented surface is an aspheric surface. The expression (1) is satisfied.
0.40 <E / f12 <2.0 (1)
here,
E is the air equivalent distance along the optical axis between the top Ct1 and the top Ct2,
The surface top Ct1 is the surface top of the surface having the most negative refractive power among the refractive surfaces on the object side of the reflective surface of the reflective optical element,
Surface top Ct2 is the surface top of the cemented surface of lens component C1p
f12 is a combined focal length of all the lenses constituting the first lens group G1 on the image side with respect to the reflective optical element. However, when the reflecting optical element has an exit surface and the exit surface has a refractive power, it is the combined focal length when the exit surface is included.

  If the upper limit of conditional expression (1) is exceeded, the imaging optical system is liable to be reduced in thickness and length. If the lower limit of conditional expression (1) is not reached, a large amount of vignetting will occur in the light rays (flux) contributing to image formation, so that a sufficient amount of light cannot be obtained at the periphery of the screen.

It is more desirable to satisfy (1 ′) instead of the conditional expression (1).
0.45 <E / f12 <1.7 (1 ')
Furthermore, it is best to satisfy (1 ″) instead of the conditional expression (1).
0.50 <E / f12 <1.5 (1 ")

  In the imaging optical system of the present embodiment, the material of the negative lens LA is preferably an energy curable resin. The lens component C1p is preferably formed by directly molding the negative lens LA on the positive lens LB.

  As described above, the cemented surface is aspherical in the lens component C1p. Such a lens component C1p can be realized by bringing a resin into close contact with the surface of the positive lens LB, which is an aspherical surface, and then curing the resin. In this case, this resin corresponds to the negative lens LA. For example, an energy curable transparent resin may be used as the resin. The resin used is particularly preferably a resin having highly dispersed optical characteristics. As described above, the method of curing the resin after adhesion is extremely effective for thinning the lens element.

  An example of the energy curable transparent resin is an ultraviolet curable resin. Further, the surface of the positive lens LB may be subjected to surface treatment (for example, coating, coating, etc.) in advance. The substance used for the surface treatment is a substance different from the optical material forming the positive lens LB.

  The positive lens LB may be an inorganic material such as glass. However, since the negative lens LA is a resin, considering the stability of the optical performance against environmental changes, the positive lens LB is more preferably a resin-based material like the negative lens LA.

  As another configuration of the lens component C1p, an optical material other than a resin may be adhered to the surface of the positive lens LB and then cured. In this case, this optical material corresponds to the negative lens LA. Note that the optical material is in a state of having a temperature equal to or higher than the transition point at the time of adhesion. The optical material is preferably a material that is advantageous in terms of resistance such as light resistance and chemical resistance, such as glass. Further, as the characteristics of the negative lens LA material, the melting point and the transition point are required to be lower than those of the positive lens LB material. As described above, the method of curing the optical material after adhesion is extremely effective for thinning the lens element.

  Even in this method, the positive lens LB may be subjected to surface treatment (for example, coating, application, etc.) in advance. The substance used for the surface treatment is a substance different from the optical material forming the positive lens LB.

  In the imaging optical system of this embodiment, a mirror or a prism can be used as the reflective optical element. However, the prism is more advantageous for downsizing the optical system than the mirror. Therefore, it is preferable to use a prism as the reflective optical element. In addition, the higher the refractive index of the medium, the better the prism. In particular, the prism preferably has a refractive index of 1.8 or more.

In the imaging optical system of the present embodiment, it is preferable that the following conditional expression (2) is satisfied.
1.60 <nd (LB) <2.4 (2)
Here, nd (LB) is the refractive index of the positive lens LB with respect to the d line.

  If the lower limit of conditional expression (2) is not reached, the optical system is likely to be downsized. If the upper limit of conditional expression (2) is exceeded, it will be difficult to prevent reflection on the refractive surface.

It is more desirable to satisfy (2 ′) instead of the conditional expression (2).
1.65 <nd (LB) <2.3 (2 ′)
Furthermore, it is best to satisfy (2 ″) instead of the conditional expression (2).
1.69 <nd (LB) <2.2 (2 ")

In the imaging optical system of the present embodiment, it is preferable that the following conditional expression (3) is satisfied.
3 <νd (LA) <35 (3)
Here, νd (LA) is the Abbe number with respect to the d-line of the negative lens LA.

  If the lower limit of conditional expression (3) is not reached, the variation in chromatic aberration due to surface accuracy error and decentration cannot be ignored. In addition, manufacturing tends to be difficult. Moreover, when the upper limit of conditional expression (3) is exceeded, it becomes difficult to erase the C line and the F line.

It is more desirable to satisfy (3 ′) instead of the conditional expression (3).
6 <νd (LA) <30 (3 ′)
Furthermore, it is best to satisfy (3 ″) instead of the conditional expression (3).
10 <νd (LA) <25 (3 ″)

  In the imaging optical system of the present embodiment, the lens group closest to the object side, that is, the first lens group G1, has a positive refractive power. In order to shorten the overall length of the imaging optical system configured in this way, it is necessary to increase the refractive power of the first lens group G1, particularly the refractive power of the lens component C1p. In order to increase the refractive power of the lens component C1p, the refractive power of the positive lens LB may be increased. Therefore, it is preferable to use an optical material having a high refractive index that satisfies any of the conditional expressions (2), (2 '), and (2 ") for the positive lens LB.

  However, when the refractive power of the positive lens LB is increased, the axial chromatic aberration in the short wavelength region and the spherical aberration in the short wavelength region due to the positive lens LB tend to be insufficiently corrected. Therefore, in the lens component C1p, a high-dispersion negative lens LA that satisfies any of the conditional expressions (3), (3 ′), and (3 ″) is used. The negative lens LA is cemented to the positive lens LB. Thus, the lens component C1p is formed, and the axial chromatic aberration in the short wavelength region is corrected by the lens component C1p.

In the imaging optical system of the present embodiment, the coordinate axis is z where the optical axis direction is z and h is the direction perpendicular to the optical axis, R is the radius of curvature of the spherical component on the optical axis, k is the conic constant, and A ₄ , A ₆ , A ₈ , A ₁₀ ... As aspherical coefficients, and the shape of the aspherical surface is expressed by the following equation (4).
When the deviation amount is expressed by the following equation (5),
It is desirable that the following conditional expression (6a) or (6b) is satisfied.
When R _C ≦ 0 Δz _C (h) <(Δz _A (h) + Δz _B (h)) / 2 <where h = 2.5a> (6a)
When R _C ≧ 0 Δz _C (h)> (Δz _A (h) + Δz _B (h)) / 2 <where h = 2.5a> (6b)
here,
z _A is the shape of the air contact surface of the negative lens LA, the shape according to equation (4),
z _B is the shape of the air contact surface of the positive lens LB, and the shape according to equation (4),
z _C is the shape of the joint surface, the shape according to equation (4),
Δz _A is a deviation amount on the air contact surface of the negative lens LA, and is an amount according to the equation (5),
Δz _B is a deviation amount on the air contact surface of the positive lens LB, and is an amount according to the equation (5),
Δz _C is the amount of deviation in the joint surface, and is an amount according to equation (5),
R _C is the paraxial radius of curvature of the joint surface,
a is an amount according to the following equation (7),
a = (y ₁₀ ) ² · log ₁₀ γ / fw (7)
In the formula (7),
y ₁₀ is the maximum image height,
fw is the focal length of the entire system at the wide angle end of the imaging optical system,
γ is the zoom ratio in the imaging optical system (total focal length at the telephoto end / total focal length at the wide angle end),
Since the top of each surface is the origin, z (0) = 0 is always set.

  When the conditional expression (6a) or (6b) is not satisfied, the spherical aberration in the short wavelength region cannot be sufficiently corrected.

  Now, with regard to axial chromatic aberration and lateral chromatic aberration, it is not sufficient to simply achromatic the C line and the F line. That is, the occurrence of chromatic aberration must be suppressed for the g-line and h-line. If the chromatic aberration cannot be sufficiently corrected for the g-line and h-line, the sharpness and contrast of the image are impaired. Alternatively, in an image having a portion (edge portion) with a large difference in illuminance, color blur is likely to occur in the vicinity of this portion.

Therefore, in the imaging optical system of the present embodiment, in an orthogonal coordinate system in which the horizontal axis is νd and the vertical axis is θgF,
θgF = α × νd + β (where α = −0.00163)
When the straight line represented by is set, the region defined by the straight line when the range is the lower limit of the range of the following conditional expression (8) and the straight line when the upper limit is set, and the conditional expression (3) described above It is preferable that θgF and νd of at least one negative lens LA constituting the lens component C1p are included in both the fixed region and the region.
0.5000 <β <0.7250 (8)
Here, θgF is a partial dispersion ratio (ng−nF) / (nF−nC), νd is an Abbe number (nd−1) / (nF−nC), nd, nC, nF, and ng are d line and C line, respectively. , F-line, and g-line refractive indexes.

  If the upper limit of conditional expression (8) is exceeded, axial chromatic aberration due to the secondary spectrum, that is, correction of axial chromatic aberration of the g-line when achromaticity is applied to the F-line and C-line, will not be sufficient. Therefore, it is difficult to ensure sharpness over the entire screen, particularly in an image obtained by imaging on the telephoto side. If the lower limit value of conditional expression (8) is not reached, lateral chromatic aberration due to the secondary spectrum, that is, lateral chromatic aberration correction for the g-line when the F-line and C-line are achromatic will be insufficient. Therefore, it is difficult to ensure the sharpness of the peripheral portion of the image in the image obtained by imaging.

It is more preferable that the following conditional expression (8 ′) is satisfied instead of conditional expression (8).
0.5900 <β <0.6600 (8 ′)
Furthermore, it is more preferable that the following conditional expression (8 ″) is satisfied instead of conditional expression (8).
0.6100 <β <0.6600 (8 ″)

Further, in the imaging optical system of the present embodiment, in an orthogonal coordinate system having a horizontal axis νd and a vertical axis θhg, which is different from the orthogonal coordinate,
θhg = αhg × νd + βhg (where αhg = −0.00225)
When the straight line represented by is set, the region defined by the straight line when the range is the lower limit of the range of the following conditional expression (9) and the straight line when the upper limit is set, and the conditional expression (3) described above It is preferable that θhg and νd of at least one negative lens LA constituting the lens component C1p are included in both the fixed region and the region.
0.4000 <βhg <0.7000 (9)
Here, .theta.hg represents the partial dispersion ratio (nh-ng) / (nF-nC), and nh represents the refractive index of the h-line.

  If the upper limit value of conditional expression (9) is exceeded, axial chromatic aberration due to the secondary spectrum, that is, correction of axial chromatic aberration of the h-line when achromatization is performed with the F-line and C-line will not be sufficient. Therefore, particularly in an image obtained by imaging on the telephoto side, purple color flare and color blur tend to occur over the entire screen. If the lower limit value of conditional expression (9) is not reached, the lateral chromatic aberration due to the secondary spectrum, that is, the lateral chromatic aberration correction for the h-line when the F-line and C-line are achromatic will be insufficient. Therefore, in the captured image, purple color flare and color blur are likely to occur in the periphery of the image.

It is more preferable that the following conditional expression (9 ′) is satisfied instead of conditional expression (9).
0.4500 <βhg <0.6400 (9 ′)
Furthermore, it is more preferable that the following conditional expression (9 ″) is satisfied instead of conditional expression (9).
0.5200 <βhg <0.5850 (9 ″)

In the imaging optical system of the present embodiment, in the orthogonal coordinate system in which the horizontal axis is νd and the vertical axis is θgF,
θgF = α × νd + β ′ (where α = −0.00163)
When the straight line represented by is set, the area defined by the straight line when it is the lower limit value and the straight line when it is the upper limit value of the range of the following conditional expression (10), and the following conditional expression (11) It is preferable that θgF and νd of a predetermined lens are included in both of the fixed region and the fixed region.
0.6100 <β ′ <0.9000 (10)
27 <νd <65 (11)
Here, the predetermined lens is at least one positive lens LB constituting the lens component C1p, or another positive lens element of the lens group G1, and θgF is a partial dispersion ratio (ng−nF) / (nF−nC). ), .Nu.d is the Abbe number (nd-1) / (nF-nC), and nd, nC, nF, and ng are the refractive indexes of the d-line, C-line, F-line, and g-line, respectively.

  If the upper limit value of conditional expression (10) is exceeded, lateral chromatic aberration due to the secondary spectrum, that is, g-line lateral chromatic aberration correction when the F-line and C-line are achromatic will be insufficient. Therefore, it is difficult to ensure the sharpness of the peripheral portion of the image in the image obtained by imaging. If the lower limit value of conditional expression (10) is not reached, axial chromatic aberration due to the secondary spectrum, that is, g-axis axial chromatic aberration correction when achromatic with the F-line and C-line will be insufficient. Therefore, it is difficult to ensure sharpness over the entire screen, particularly in an image obtained by imaging on the telephoto side.

  If the upper limit of conditional expression (11) is exceeded, the correction effect for Seidel's five aberrations will be reduced even if the F-line and C-line can be achromatic. If the lower limit of conditional expression (11) is not reached, it will be difficult to erase the F line and the C line.

It is more preferable that the following conditional expression (10 ′) is satisfied instead of conditional expression (10).
0.6200 <β <0.8500 (10 ′)
Furthermore, it is more preferable that the following conditional expression (10 ″) is satisfied instead of conditional expression (10).
0.6250 <β <0.8000 (10 ″)

It is more preferable that the following conditional expression (11 ′) is satisfied instead of conditional expression (11).
30 <νd <60 (11 ′)
Furthermore, it is more preferable that the following conditional expression (11 ″) is satisfied instead of conditional expression (11).
35 <νd <55 (11 ″)

In the imaging optical system of the present embodiment, in the orthogonal coordinate system in which the horizontal axis is νd and the vertical axis is θhg,
θhg = αhg × νd + βhg ′ (where αhg = −0.00225)
When the straight line represented by is set, the area defined by the straight line when the range is the lower limit of the range of the following conditional expression (12) and the straight line when the upper limit is set, and the following conditional expression (11) It is preferable that θhg and νd of a predetermined lens are included in both of the fixed region and the fixed region.
0.5000 <βhg ′ <0.9000 (12)
27 <νd <65 (11)
Here, the predetermined lens is at least one positive lens LB constituting the lens component C1p, or another positive lens element of the lens group G1, and θhg is a partial dispersion ratio (nh−ng) / (nF−nC). Nh represents the refractive index of the h-line.

  If the upper limit value of conditional expression (12) is exceeded, lateral chromatic aberration due to the secondary spectrum, that is, lateral chromatic aberration correction for the h-line when achromaticity is applied to the F-line and C-line will not be sufficient. Therefore, in an image obtained by imaging, purple color flare and color blur are likely to occur in the periphery of the image. If the lower limit value of conditional expression (12) is not reached, axial chromatic aberration due to the secondary spectrum, that is, correction of axial chromatic aberration of the h-line when achromatization is performed with the F-line and C-line will not be sufficient. Therefore, particularly in an image obtained by imaging on the telephoto side, purple color flare and color blur tend to occur over the entire screen.

It is more preferable that the following conditional expression (12 ′) is satisfied instead of conditional expression (12).
0.5500 <βhg <0.8700 (12 ′)
Furthermore, it is more preferable that the following conditional expression (12 ″) is satisfied instead of conditional expression (12).
0.5600 <βhg <0.8500 (12 ″)

Moreover, it is preferable that the imaging optical system of this embodiment satisfies the following conditional expression (13).
−0.06 ≦ θgF (LA) −θgF (LB) ≦ 0.18 (13)
Here, θgF (LA) is the partial dispersion ratio (ng−nF) / (nF−nC) of the negative lens LA, and θgF (LB) is the partial dispersion ratio (ng−nF) / (nF−nC) of the positive lens LB. It is.

  In this case, since a negative lens (negative lens LA) and a positive lens (positive lens LB) are combined, chromatic aberration can be corrected satisfactorily. In particular, when the above condition is satisfied with this combination, the correction effect on the secondary spectrum (chromatic aberration) increases. As a result, sharpness increases in an image obtained by imaging.

It is more desirable to satisfy (13 ′) instead of the conditional expression (13).
−0.03 ≦ θgF (LA) −θgF (LB) ≦ 0.14 (13 ′)
Furthermore, it is best to satisfy (13 ″) instead of the conditional expression (13).
0.00 ≦ θgF (LA) −θgF (LB) ≦ 0.10 (13 ″)

Moreover, it is preferable that the imaging optical system of this embodiment satisfies the following conditional expression (14).
−0.10 ≦ θhg (LA) −θhg (LB) ≦ 0.24 (14)
Where θhg (LA) is the partial dispersion ratio (nh-ng) / (nF-nC) of the negative lens LA, and θhg (LB) is the partial dispersion ratio (nh-ng) / (nF-nC) of the positive lens LB. It is.

  In this case, since it is a combination of a negative lens (negative lens LA) and a positive lens (positive lens LB), chromatic aberration can be corrected satisfactorily. In particular, when the above conditions are satisfied with this combination, color flare and color blur can be reduced in an image obtained by imaging.

It is more desirable to satisfy (14 ′) instead of the conditional expression (14).
−0.05 ≦ θhg (LA) −θhg (LB) ≦ 0.19 (14 ′)
Further, it is best to satisfy (14 ″) instead of the conditional expression (14).
0.00 ≦ θhg (LA) −θhg (LB) ≦ 0.14 (14 ″)

Moreover, it is preferable that the imaging optical system of this embodiment satisfies the following conditional expression (15).
νd (LA) −νd (LB) ≦ −5 (15)
Here, νd (LA) is the Abbe number (nd−1) / (nF−nC) of the negative lens LA, and νd (LB) is the Abbe number (nd−1) / (nF−nC) of the positive lens LB.

  In this case, since it is a combination of a negative lens (negative lens LA) and a positive lens (positive lens LB), chromatic aberration can be corrected satisfactorily. In particular, when the above condition is satisfied with this combination, the C-line and F-line among the longitudinal chromatic aberration and the lateral chromatic aberration are easily erased.

It is more desirable to satisfy (15 ′) instead of the conditional expression (15).
νd (LA) −νd (LB) ≦ −10 (15 ′)
Further, it is best to satisfy (15 ″) instead of the conditional expression (15).
νd (LA) −νd (LB) ≦ −15 (15 ″)

  When the lens component C1p is composed of three or more lenses, the negative lens having the smallest θgF value among negative lenses is denoted by LA, and the positive lens having the largest θgF value among positive lenses is denoted by LB. To do.

  Here, the glass material means a lens material such as glass or resin. For the cemented lens (including the lens component C1p), a lens appropriately selected from these glass materials is used.

Next, the imaging optical system of this embodiment will be described.
The imaging optical system of the present embodiment has a 5-group configuration or a 6-group configuration. Further, there are the following three refractive power arrangements in the imaging optical system having the 5-group configuration or the 6-group configuration in which the most object side lens group G1 has a positive refractive power.
Positive, negative, (positive), positive, negative, positive positive, negative, (positive), positive, positive, positive positive, negative, (positive), positive, positive, negative When there is a (positive) lens group Is a 6-group configuration, and when there is no 5-group configuration. The aperture stop is disposed in any space from the image side of the second lens group from the object side to the object side of the fourth lens group. The aperture stop may or may not be independent of the lens group.

  It can be said that the imaging optical system of the present embodiment has a basic configuration of positive / negative / positive / positive refractive power arrangement or positive / negative / positive / negative refractive power arrangement. For example, a five-group imaging optical system can be regarded as a modified optical system of a positive, negative, positive, positive, or positive, negative, positive, negative four-group imaging optical system. That is, a positive or negative lens group on the image side of a positive, negative, positive, positive four-group imaging optical system, or an image side of a positive, negative, positive, negative four-group imaging optical system It can also be considered that a positive lens group is arranged in the. Further, in the case of the 6-group configuration, it can be considered that a positive lens group is arranged between the first negative lens group and the second positive lens group from the object side in the 5-group configuration.

  When the positive, negative, positive, and positive refractive power arrangement is the basic configuration, the first lens group G1 having the positive refractive power closest to the object side is arranged. In this configuration, the lens component C1p is disposed in the first lens group G1. Furthermore, the conditional expression (1) or (1 ′) or (1 ″) is satisfied.

  A negative lens LA is used for the lens component C1p. The negative lens LA has both a region defined by a straight line when the lower limit value of the range of the conditional expression (8) and a straight line when the upper limit value are satisfied, and a region determined by the conditional expression (3). The lens includes θgF and νd. The negative lens LA is a lens in which θgF and νd are included in a region defined by the conditional expression (3 ′) and the conditional expression (8 ′) or the conditional expression (3 ″) and the conditional expression (8 ″). Also good.

  Further, a positive lens LB is cemented to the negative lens LA in the lens component C1p. The positive lens LB is a lens that satisfies the conditional expression (2) or (2 ') or (2 ").

  The lens component C1p should have a positive refractive power. Moreover, it is preferable that each surface (air contact surface, cemented surface) of the lens component C1p satisfies the conditional expression (6a) or (6b).

  Further, on the object side of the lens component C1p, a reflective optical element is disposed along the optical path of the imaging optical system. The reflective optical element is preferably a prism having an incident surface, a reflective surface, and an exit surface in order from the object side. It should be noted that a surface having negative refractive power is preferably present immediately on the object side of the incident surface of the prism. Alternatively, the incident surface of the prism itself may have a negative refractive power. In that case, there may be no surface having negative refractive power on the object side of the incident surface of the prism. Further, it is desirable that at least one of the incident surface and the exit surface of the prism is a flat surface.

In addition, it is preferable that the imaging optical system of the present embodiment includes the second lens group G2 that has negative refractive power and is movable during zooming, and satisfies the following conditional expression (16). The second lens group G2 is the second lens group from the object side.
−1.2 <β _2w <−0.3 (16)
However, β _2w is the imaging magnification at the wide-angle end of the second lens group G2, and is at any object point where the absolute value of the imaging magnification of the entire imaging optical system at the wide-angle end is 0.01 or less. This is the imaging magnification when focused.

  If the lower limit of conditional expression (16) is not reached, it will be difficult to increase the zooming efficiency even if the lens group other than the second lens group G2 shares the zooming. As a result, it is difficult to reduce the size of the optical system. If the upper limit of conditional expression (16) is exceeded, the zooming efficiency due to the movement of the second lens group G2 itself deteriorates. Also in this case, it is difficult to reduce the size of the optical system. The zooming efficiency is represented by the ratio between the moving amount of the lens unit and the zooming amount. For example, when the moving amount of the lens group is small and the zooming is large, the zooming efficiency is high.

It is more desirable to satisfy (16 ′) instead of the conditional expression (16).
−1.1 <β _2w <−0.4 (16 ′)
Further, it is best to satisfy (16 ″) instead of the conditional expression (16).
−1.0 <β _2w <−0.5 (16 ″)

Further, the imaging optical system of the present embodiment has a third lens group G3 having a positive refractive power and a fourth lens group G4 having a positive refractive power following the second lens group G2, and the following conditions It is preferable to satisfy Expression (17).
−1.8 <β _34w <−0.3 (17)
Here, β _34w is the imaging magnification of the composite system at the wide-angle end of the third lens group G3 and the fourth lens group G4, and the absolute value of the imaging magnification of the entire imaging optical system at the wide-angle end is 0. This is the imaging magnification when focusing on any object point of 01 or less.

  In the imaging optical system having a five-group configuration, the third lens group G3 is the third lens group from the object side. The third lens group G3 is the second lens group from the object side as a positive lens group. On the other hand, the fourth lens group G4 is the fourth lens group from the object side. The fourth lens group G4 is the third positive lens group from the object side.

  If the lower limit of conditional expression (17) is not reached, it is difficult to increase the zooming efficiency even if the zooming function is shared by the lens group G2. As a result, it is difficult to reduce the size of the optical system. If the upper limit of conditional expression (17) is exceeded, the zooming efficiency due to the movement of the third lens group G3 and the fourth lens group G4 itself deteriorates. Also in this case, it is difficult to reduce the size of the optical system.

It is more desirable to satisfy (17 ′) instead of the conditional expression (17).
−1.8 <β _34w <−0.4 (17 ′)
Further, it is best to satisfy (17 ″) instead of the conditional expression (17).
−1.8 <β _34w <−0.5 (17 ″)

Note that another lens group G31 having a positive refractive power may be disposed between the second lens group G2 and the third lens group G3. By doing in this way, it can be set as the imaging optical system of 6 groups composition. In such a configuration, it is preferable that the imaging optical system of the present embodiment satisfies the following conditional expression (17-1).
−1.8 <β _34w ′ <−0.3 (17-1)
Here, β _34w ′ is the imaging magnification of the combined system at the wide-angle end of another lens group G31, the third lens group G3, and the fourth lens group G4, and the imaging of the entire imaging optical system at the wide-angle end This is the imaging magnification when focusing on any object point where the absolute value of the magnification is 0.01 or less.

It is more desirable to satisfy (17′-1) instead of the conditional expression (17-1).
−1.8 <β _34w ′ <−0.4 ( _17′− 1)
Furthermore, it is best to satisfy (17 ″ −2) instead of the conditional expression (17).
-1.8 <β _34w '<-0.5 (17 "-2)

Further, the imaging optical system of the present embodiment has the fifth lens group G5 on the most image side. The fifth lens group G5 is composed of only lens components having a substantially constant distance from the image plane at the time of zooming. At the time of zooming, the relative distance between the fifth lens group G5 and the lens group adjacent to the fifth lens group G5 changes. In such a configuration, it is preferable that the imaging optical system of the present embodiment satisfies the following conditional expression (18).
0.95 <β _5W <2.5 (18)
However, β _5W is the image forming magnification of the fifth lens group G5, and the image is formed when focusing on any object point where the absolute value of the image forming magnification of the entire system at the wide angle end is 0.01 or less. Magnification.

  If the fifth lens group G5 has negative refractive power (the magnification of the lens group itself is large), it is easy to reduce the size of the optical system. On the other hand, if the fifth lens group G5 has a positive refractive power (the magnification of the lens group itself is reduced), aberration correction is easy. Therefore, the refractive power of the fifth lens group G5 may be positive or negative.

  Below the lower limit of conditional expression (18), it is difficult to achieve both high magnification, wide angle, large aperture ratio, and shortening of the overall length. If the upper limit of conditional expression (18) is exceeded, the Petzval sum becomes a large negative value, so that the curvature of the image plane remarkably occurs.

It is more desirable to satisfy (18 ′) instead of the conditional expression (18).
1.00 <β _5w <2.2 (18 ′)
Further, it is best to satisfy (18 ″) instead of the conditional expression (18).
1.05 <β _5w <2.0 (18 ″)

In the imaging optical system of the present embodiment, the fifth lens group G5 may have one convex lens and one concave lens. In such a configuration, the imaging optical system of the present embodiment should satisfy the following conditional expression (19).
0.35 <N _5n −N _5p <0.95 (19)
Here, N _5p and N _5n are refractive indexes with respect to the d-line of the medium forming the convex lens and the concave lens of the fifth lens group G5, respectively.

  If the lower limit of conditional expression (19) is not reached, the Petzval sum tends to be a large negative value. As a result, correction of field curvature or astigmatism is insufficient. If the upper limit of conditional expression (19) is exceeded, internal coma tends to occur.

It is more desirable to satisfy (19 ′) instead of the conditional expression (19).
0.40 <N _5n −N _5p <0.85 (19 ′)
Furthermore, it is best to satisfy (19 ″) instead of the conditional expression (19).
0.45 <N _5n −N _5p <0.75 (19 ″)

Moreover, it is preferable that the imaging optical system of this embodiment satisfies the following conditional expression (20).
0 <ν _5n −ν _5p <80 (20)
Here, ν _Rp and ν _Rn are Abbe numbers for the d-line of the medium forming the convex lens and the concave lens of the fifth lens group G5, respectively.

  In particular, when a reflective optical element for bending the optical path is inserted into the first lens group G1, lateral chromatic aberration is likely to occur. Conditional expression (20) is a condition for correcting lateral chromatic aberration. If the upper limit of conditional expression (20) is exceeded or below the lower limit, it will be difficult to correct lateral chromatic aberration.

It is more desirable to satisfy (20 ′) instead of the conditional expression (20).
5 <ν _5n −ν _5p <70 (20 ′)
Further, it is best to satisfy (20 ″) instead of the conditional expression (20).
10 <ν _5n −ν _5p <60 (20 ″)

In the imaging optical system of the present embodiment, the convex lens and the concave lens of the fifth lens group G5 are cemented with each other. In such a configuration, it is preferable that the imaging optical system of the present embodiment satisfies the following conditional expressions (21) and (22).
1 / R _G5F > 1 / R _G5R (21)
0 <(R _G5F −R _G5R ) / (R _G5F + R _G5R ) <5.00 (22)
Here, R _G5F and R _G5R are the paraxial radius of curvature of the most object side surface and the paraxial radius of curvature of the most image side surface of the fifth lens group G5, respectively.

  If the conditional expression (21) is not satisfied, coma and astigmatism are likely to occur. Conditional expression (22) represents the reciprocal of a so-called shape factor. If the upper limit of conditional expression (22) is exceeded, the dead space that cannot be used for movement at the time of zooming increases, which makes it easy to increase the overall length. If the lower limit of conditional expression (22) is not reached, coma and barrel distortion are likely to occur.

It is more desirable to satisfy (21 ′) and (22 ′) instead of the conditional expressions (21) and (22).
1 / R _G5F > 1 / R _G5R (21 ')
0 <(R _G5F −R _G5R ) / (R _G5F + R _G5R ) <1.50 (22 ′)
Furthermore, it is best to satisfy (21 ″) and (22 ″) instead of the conditional expressions (21) and (22).
1 / R _G5F > 1 / R _G5R (21 ")
0 <(R _G5F −R _G5R ) / (R _G5F + R _G5R ) <1.00 (22 ”)

  The imaging optical system of the embodiment includes a five-group imaging optical system and a six-group imaging optical system. The imaging optical system having a five-group configuration includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, an aperture stop, and a third lens having a positive refractive power. The lens group G3 includes five lens groups, a fourth lens group G4 having a positive refractive power and a fifth lens group G5 having a positive or negative refractive power.

  Further, the imaging optical system having a six-group configuration includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a third lens having a positive refractive power. It consists of six lens groups: a group G31, a fourth lens group G3 having a positive refractive power, a fifth lens group G4 having a positive refractive power, and a sixth lens group G5 having a positive or negative refractive power. Note that the third lens group G31 can be configured integrally with an aperture stop.

  The first lens group G1 includes two to four lens components and a reflective optical element as components. These components are preferably arranged in order of at most one lens component, reflective optical element, or one or two positive lens components from the object side. One or two positive lens components include a lens component C1p. Particularly, from the object side, the negative lens component having a concave surface on the image side, the reflective optical element, and one or two positive lens components may be arranged in this order. The reflective optical element is preferably a prism.

The details of the configuration of the first lens group G1 are as follows.
(A) From the object side, a negative lens component having a concave surface on the image side, a reflective optical element, and one or two positive lens components. Here, the reflecting optical element is a prism having a flat incident surface, reflecting surface, and exit surface.
(B) From the object side, the order of the reflective optical element and one or two positive lens components. Here, the reflective optical element is a prism having a concave incident surface and a reflective surface and an exit surface. Both the reflection surface and the exit surface are flat.
(C) From the object side, the negative lens component having a concave surface on the image side, the reflective optical element, and the two positive lens components. Here, the reflective optical element is a prism having a concave incident surface and a reflective surface and an exit surface. Both the reflection surface and the exit surface are flat.
(D) From the object side, the negative lens component having a concave surface on the image side, the reflective optical element, and the positive lens component alone. Here, the reflective optical element is a prism having an incident surface and a reflective surface and a convex exit surface. Both the incident surface and the reflecting surface are flat.

  As described above, in the first lens group G1, the arrangement of the constituent elements may be any one of the above arrangements. The prism is a reflective optical element for bending the optical path. Further, it is preferable that the refractive index of the medium of the prism (reflection optical element) is 1.8 or more because the conditional expression (1) is easily satisfied.

  One of the positive lens components is the lens component C1p. A negative lens LA is used for the lens component C1p. The negative lens LA has both a region defined by a straight line when the lower limit value of the range of the conditional expression (8) and a straight line when the upper limit value are satisfied, and a region determined by the conditional expression (3). The lens includes θgF and νd. The negative lens LA is a lens in which θgF and νd are included in a region defined by the conditional expression (3 ′) and the conditional expression (8 ′) or the conditional expression (3 ″) and the conditional expression (8 ″). Also good.

  In the lens component C1p, the negative lens LA is joined to the positive lens LB. The positive lens LB has both a region defined by a straight line when the lower limit value of the range of the conditional expression (10) and a straight line when the upper limit value are satisfied, and a region determined by the conditional expression (11). The lens includes θgF and νd. The positive lens LB is a lens in which θgF and νd are included in a region defined by the conditional expression (10 ′) and the conditional expression (11 ′) or the conditional expression (10 ″) and the conditional expression (11 ″). Also good.

  The second lens group G2 has two or more lens components. Any one of the lens components is a cemented lens component including a positive lens and a negative lens. The second lens group G2 may include one or more negative lens components in addition to the cemented lens component. It is desirable that the negative lens component, the cemented lens component, and other lens components are arranged in this order from the object side.

  When the imaging optical system has a five-group configuration, the third lens group G3 has a cemented lens. The third lens group G3 may include a positive lens component in addition to the cemented lens component. In the third lens group G3, it is preferable that the most image side lens is a negative lens. Further, this negative lens has a stronger curvature on the image side surface. When the imaging optical system has a six-group configuration, the third lens group G3 becomes the fourth lens group G3.

  The fourth lens group G4 has one lens component. The fourth lens group G4 is a lens group following the third lens group G3. The refractive power of the fourth lens group G4 may be positive or negative. The lens component may be a single lens. The fourth lens group G4 has a negative refractive power and is more easily miniaturized, and a positive refractive power is easier to correct aberrations. When the imaging optical system has a six-group configuration, the fourth lens group G4 becomes the fifth lens group G4.

  The fifth lens group G5 has one lens component. This lens component may be a single lens. The fifth lens group G4 may have a positive or negative refractive power. Note that the fifth lens group G5 has a negative refractive power and is more easily miniaturized, and a positive refractive power makes it easier to correct aberrations. When the imaging optical system has a six-group configuration, the fifth lens group G4 becomes the sixth lens group G5.

  When the imaging optical system has a six-group configuration, another lens group G31 having a positive refractive power is disposed between the second lens group G2 and the third lens group G3. Another lens group G31 is composed of a single lens, and may be composed integrally with an aperture stop. When the imaging optical system has a six-group configuration, another lens group G31 is the third lens group G31.

  Further, if the distortion generated in the imaging optical system is corrected by the image processing function of the electronic imaging apparatus, other aberrations can be corrected satisfactorily, and at the same time, a wider angle can be obtained.

  When the negative lens LA is used for the lens component C1p, the negative lens LA is cemented with the positive lens LB. At this time, the center thickness of the optical axis of the negative lens LA is preferably thinner than that of the positive lens LB.

In the imaging optical system of the present embodiment, it is preferable that the optical axis center thickness t1 of the negative lens LA satisfies the following conditional expression (23).
0.01 <t1 <0.6 (23)

It is more preferable that the following conditional expression (23 ′) is satisfied instead of conditional expression (23).
0.01 <t1 <0.4 (23 ′)
Furthermore, it is more preferable that the following conditional expression (23 ″) is satisfied instead of conditional expression (23).
0.01 <t1 <0.2 (23 ")

By the way, suppose that an object at infinity is imaged by an optical system without distortion. In this case, since the image formed has no distortion,
f = y / tan ω (24)
Is established.

  Here, y is the height of the image point from the optical axis, f is the focal length of the imaging system, and ω is the angle with respect to the optical axis in the object direction corresponding to the image point connected from the center on the imaging surface to the y position. It is.

On the other hand, if the optical system has barrel distortion,
f> y / tan ω (25)
It becomes. That is, if f and y are constant values, ω is a large value.

  Therefore, it is preferable to use an optical system that intentionally has a large barrel distortion, particularly at a focal length near the wide-angle end, for the electronic imaging device. In this case, it is possible to achieve a wider angle of view of the optical system as much as it is not necessary to correct distortion.

  However, the image of the object is formed on the electronic image pickup device in a state having barrel-shaped distortion. Therefore, in the electronic imaging device, image data obtained by the electronic imaging element is processed by image processing. In this processing, the image data (image shape) is changed so as to correct the barrel distortion.

  In this way, the finally obtained image data is image data having a shape substantially similar to the object. Therefore, an object image may be output to a CRT or printer based on the image data.

Therefore, in the electronic imaging apparatus of the present embodiment, the image shape obtained by processing the electronic imaging device and the image formed by imaging the image formed through the imaging optical system is processed to change the shape of the image. Preferably, the image forming optical system is a zoom lens, and the zoom lens satisfies the following conditional expression (26) when focusing on an object point at almost infinity.
0.70 <y ₀₇ / (fw · tan ω _07w ) <0.96 (26)
Here, y ₀₇ is expressed as y ₀₇ = 0.7y ₁₀ when the maximum image height is y _10, and ω _07w is an object corresponding to the image point connecting from the center on the imaging surface at the wide angle end to the position of y ₀₇ . This is the angle with respect to the optical axis in the point direction. Note that when the present embodiment is an electronic imaging device, the maximum image height is the distance from the center to the farthest point in the effective imaging plane of the electronic imaging device (within the imageable plane). Accordingly, y ₁₀ becomes the distance to the point farthest from the center in the effective image pickup plane of the electronic imaging device (imaging possible in-plane).

  Conditional expression (26) defines the degree of barrel distortion at the zoom wide-angle end. If conditional expression (26) is satisfied, it becomes possible to capture information with a wide angle of view without enlarging the optical system. Note that an image distorted in a barrel shape is photoelectrically converted by an image sensor to become image data distorted in a barrel shape.

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

  Here, when the value exceeds the upper limit value of conditional expression (26), and particularly when the value is close to 1, an image in which distortion is optically corrected is obtained. Therefore, the correction performed by the image processing means can be small. However, it becomes difficult to widen the angle of view of the optical system while maintaining the miniaturization of the optical system.

  On the other hand, below the lower limit value of conditional expression (26), when image distortion due to distortion of the optical system is corrected by the image processing means, the stretching ratio in the radial direction around the angle of view becomes too high. As a result, in the image obtained by imaging, the sharpness degradation at the periphery of the image becomes conspicuous.

  Thus, by satisfying conditional expression (26), it is possible to reduce the size and widen the angle of the optical system (make the vertical angle of view of distortion more than 38 °).

It is more preferable that the following conditional expression (26 ′) is satisfied instead of conditional expression (26).
0.75 <y ₀₇ / (fw · tan ω _07w ) <0.955 (26 ′)
Furthermore, it is more preferable that the following conditional expression (29 ″) is satisfied instead of conditional expression (26).
0.80 <y ₀₇ / (fw · tan ω _07w ) <0.95 (26 ”)

In the imaging optical system of the present embodiment, it is preferable that the negative lens LA satisfies the following conditional expression (27).
1.58 <nd <1.95 (27)
Here, nd is the refractive index of the medium of the negative lens LA.

  When the conditional expression (27) is satisfied, the spherical aberration and the astigmatism can be corrected satisfactorily.

It is more preferable that the following conditional expression (27 ′) is satisfied.
1.60 <nd <1.90 (27 ')
Further, it is more preferable that the following conditional expression (27 ″) is satisfied.
1.62 <nd <1.85 (27 ")

  The imaging optical system of the present invention can achieve both downsizing and thinning of the imaging optical system by satisfying or having the conditional expressions and structural features described above individually. Good aberration correction can be realized. In addition, the imaging optical system of the present invention can be provided with (satisfied with) the above conditional expressions and structural features in combination. In this case, the image-forming optical system can be further reduced in size and thickness, or better aberration correction can be achieved.

  In addition, the electronic imaging apparatus having the imaging optical system of the present invention is provided with such an imaging optical system, so that it is possible to sharpen the image and prevent color blur in the captured image.

  Embodiments of an imaging optical system (hereinafter referred to as “zoom lens” as appropriate) and an electronic imaging apparatus according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

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

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

  As shown in FIG. 1, the zoom lens of Example 1 includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, an aperture stop S, and a positive A third lens group G3 having a negative refractive power, a fourth lens group G4 having a positive refractive power, and a fifth lens group G5 having a negative refractive power. In all the following examples, in the lens cross-sectional views, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

  The first lens group G1 includes a negative meniscus lens L1 having a convex surface directed toward the object side, a prism L2 having both an object-side surface and an image-side surface planar, and a biconvex positive lens L3 and a convex surface directed toward the image side. It is composed of a cemented lens (lens component C1p) of the negative meniscus lens L4, and has a positive refractive power as a whole.

  In this embodiment, f12 is the combined focal length of the lens L3 and the lens L4. Further, the surface top Ct1 is the surface top of the image side surface of the lens L1, and the surface top Ct2 is the surface top of the cemented surface of the cemented lens (lens L3 and lens L4).

  The second lens group G2 includes a negative meniscus lens L5 having a convex surface directed toward the object side, and a cemented lens of a biconcave negative lens L6 and a biconvex positive lens L7, and has a negative refracting power as a whole. Yes.

  The third lens group G3 includes a biconvex positive lens L8 on the object side, and a cemented lens of a biconvex positive lens L9 and a biconcave negative lens L10, and has a positive refracting power as a whole.

  The fourth lens group G4 is a positive meniscus lens L11 having a convex surface directed toward the object side, and has a positive refractive power.

  The fifth lens group G5 includes a cemented lens which is a biconcave negative lens L12 and a biconvex positive lens L13, and has a negative refracting power as a whole.

  During zooming from the wide angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 moves to the image side, the third lens group G3 moves to the object side, and the fourth lens group G4. Is substantially fixed to the intermediate position, moved from the intermediate position to the image side, and the fifth lens group G5 is fixed. The position of the aperture stop S is fixed. The light amount is adjusted by changing the aperture size of the aperture stop S.

  The aspherical surfaces have the convex surfaces facing both surfaces of the biconvex positive lens L3 of the first lens group G1, the image side surface of the negative meniscus lens L4 with the convex surface facing the image side, and the object side of the second lens group G2. The image side surface of the negative meniscus lens L5, both surfaces of the biconvex positive lens L8 on the object side of the third lens group G3, and the object side of the positive meniscus lens L11 with the convex surface facing the object side of the fourth lens group G4. A total of eight surfaces including the surface and the object side surface of the biconcave negative lens L12 of the fifth lens group G5 are provided.

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

  4A and 4B are diagrams showing spherical aberration, astigmatism, distortion aberration, and chromatic aberration of magnification when the zoom lens according to Example 2 is focused on an object point at infinity, where FIG. 4A is a wide angle end, and FIG. 4B is an intermediate focus. The distance state, (c) shows the state at the telephoto end.

  As shown in FIG. 3, the zoom lens of Example 2 includes, in order from the object side, a first lens unit G1 having a positive refractive power, a second lens unit G2 having a negative refractive power, an aperture stop S, and a positive lens unit. A third lens group G3 having a refractive power of 4, a fourth lens group G4 having a positive refractive power, and a fifth lens group G5 having a positive refractive power.

  The first lens group G1 includes a negative meniscus lens L1 having a convex surface directed toward the object side, a prism L2 having both an object-side surface and an image-side surface planar, and a biconvex positive lens L3 and a convex surface directed toward the image side. It is composed of a cemented lens (lens component C1p) of the negative meniscus lens L4 and a biconvex positive lens L5, and has a positive refractive power as a whole.

  In this embodiment, f12 is the combined focal length of the lens L3 and the lens L4. Further, the surface top Ct1 is the surface top of the image side surface of the lens L1, and the surface top Ct2 is the surface top of the cemented surface of the cemented lens (lens L3 and lens L4).

  The second lens group G2 includes a cemented lens of a biconcave negative lens L6, a biconcave negative lens L7, and a positive meniscus lens L8 having a convex surface directed toward the object side, and has a negative refracting power as a whole. .

  The third lens group G3 includes a biconvex positive lens L9, and a cemented lens of a biconvex positive lens L10 and a biconcave negative lens L11, and has a positive refractive power as a whole.

  The fourth lens group G4 is a biconvex positive lens L12 and has positive refractive power.

  The fifth lens group G5 includes a cemented lens which is a biconcave negative lens L13 and a biconvex positive lens L14, and has a positive refracting power as a whole.

  During zooming from the wide angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 moves to the image side, the third lens group G3 moves to the object side, and the fourth lens group G4. Is substantially fixed to an intermediate position, moved from the intermediate position to the image side, and the fifth lens group G5 is fixed. The position of the aperture stop S is fixed. The light amount is adjusted by changing the opening size.

  The aspherical surface includes both surfaces of the biconvex positive lens L3 of the first lens group G1, the image side surface of the negative meniscus lens L4 with the convex surface facing the image side, and the biconcave negative lens L6 on the object side of the second lens group G2. Are provided on a total of seven surfaces: the image-side surface, the both surfaces of the object-side biconvex positive lens L9 of the third lens group G3, and the object-side surface of the biconvex positive lens L12 of the fourth lens group G4. .

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

  6A and 6B are diagrams illustrating spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 3 is focused on an object point at infinity, in which FIG. 6A is a wide-angle end, and FIG. 6B is an intermediate focus. The distance state, (c) shows the state at the telephoto end.

  As shown in FIG. 5, the zoom lens according to the third exemplary embodiment includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, an aperture stop S, and a positive lens. A third lens group G3 having a refractive power of 4, a fourth lens group G4 having a positive refractive power, and a fifth lens group G5 having a positive refractive power.

  The first lens group G1 includes a negative meniscus lens L1 having a convex surface facing the object side, a prism L2 having a flat object side surface and a convex image surface, a negative meniscus lens L3 having a convex surface facing the object side, and a biconvex lens. It is composed of a cemented lens (lens component C1p) of the positive lens L4, and has a positive refractive power as a whole.

  In this embodiment, f12 is the combined focal length of the lens L2 (the image side surface of the lens L2), the lens L3, and the lens L4. Further, the surface top Ct1 is the surface top of the image side surface of the lens L1, and the surface top Ct2 is the surface top of the cemented surface of the cemented lens (lens L3 and lens L4).

  The second lens group G2 includes a negative meniscus lens L5 having a convex surface facing the object side, a cemented lens of a biconcave negative lens L6 and a positive meniscus lens L7 having a convex surface facing the object side, and is negatively refracted as a whole. Have power.

  The third lens group G3 includes a biconvex positive lens L8, and a cemented lens of a biconvex positive lens L9 and a biconcave negative lens L10, and has a positive refractive power as a whole.

  The fourth lens group G4 is a positive meniscus lens L11 having a convex surface directed toward the object side, and has a positive refractive power.

  The fifth lens group G5 includes a cemented lens which is a biconcave negative lens L12 and a biconvex positive lens L13, and has a positive refracting power as a whole.

  During zooming from the wide angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 moves to the image side, the third lens group G3 moves to the object side, and the fourth lens group G4. Moves slightly toward the object side to the intermediate position, moves from the intermediate position to the image side, and the fifth lens group G5 is fixed. The position of the aperture stop S is fixed. The light amount is adjusted by changing the aperture size of the aperture stop S.

  The aspherical surfaces are a negative meniscus having a convex surface facing the object side of the first lens group G1 and a negative meniscus lens L3 having a convex surface facing the object side, an image side surface of the biconvex positive lens L4, and an object side of the second lens group G2. The image-side surface of the lens L5, both surfaces of the biconvex positive lens L8 of the third lens group G3, the object-side surface of the positive meniscus lens L11 with the convex surface facing the object side of the fourth lens group G4, and a fifth A total of eight surfaces on the image side of the biconvex positive lens L13 of the lens group G5 are provided.

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

  8A and 8B are diagrams showing spherical aberration, astigmatism, distortion aberration, and chromatic aberration of magnification when the zoom lens according to Example 4 is focused on an object point at infinity, in which FIG. 8A is a wide-angle end, and FIG. The distance state, (c) shows the state at the telephoto end.

  As shown in FIG. 5, the zoom lens of Example 4 includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, an aperture stop S, and a positive A third lens group G3 having a refractive power of 4, a fourth lens group G4 having a positive refractive power, and a fifth lens group G5 having a positive refractive power.

  The first lens group G1 includes a negative meniscus lens L1 having a convex surface directed toward the object side, a prism L2 having a concave surface on the object side and a flat image surface, a biconvex positive lens L3, a biconvex positive lens L4, and both It is composed of a cemented lens (lens component C1p) of the concave negative lens L5, and has a positive refractive power as a whole.

  In this embodiment, f12 is the combined focal length of the lens L3, the lens L4, and the lens L5. Further, the surface top Ct1 is the surface top of the image side surface of the lens L1, and the surface top Ct2 is the surface top of the cemented surface of the cemented lens (lens L4 and lens L5).

  The second lens group G2 includes a cemented lens of a biconcave negative lens L6, a biconcave negative lens L7, and a positive meniscus lens L8 having a convex surface directed toward the object side, and has a negative refracting power as a whole. Yes.

  The third lens group G3 includes a biconvex positive lens L9, and a cemented lens of a biconvex positive lens L10 and a biconcave negative lens L11, and has a positive refractive power as a whole.

  The fourth lens group G4 is a positive meniscus lens L12 having a convex surface directed toward the object side, and has a positive refractive power.

  The fifth lens group G5 includes a cemented lens which is formed by a negative meniscus lens L13 having a convex surface directed toward the object side and a biconvex positive lens L14, and has a positive refracting power as a whole.

  During zooming from the wide angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 moves to the image side, the third lens group G3 moves to the object side, and the fourth lens group G4. Moves slightly toward the object side to the intermediate position, moves from the intermediate position to the image side, and the fifth lens group G5 is fixed. The position of the aperture stop S is fixed. The light amount is adjusted by changing the opening size.

  The aspherical surface includes an image side surface of the negative meniscus lens L1, a double convex positive lens L4, an image side surface of the biconcave negative lens L5, and a second lens. An image side surface of the object side biconcave negative lens L6 of the group G2, a double surface of the object side biconvex positive lens L9 of the third lens group G3, and a positive surface with the convex surface facing the object side of the fourth lens group G4 A total of nine surfaces including the object side surface of the meniscus lens L12 and the image side surface of the biconvex positive lens L14 of the fifth lens group G5 are provided.

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

  10A and 10B are diagrams showing spherical aberration, astigmatism, distortion aberration, and chromatic aberration of magnification when the zoom lens according to Example 5 is focused on an object point at infinity, where FIG. 10A is a wide-angle end, and FIG. 10B is an intermediate focus. The distance state, (c) shows the state at the telephoto end.

  As shown in FIG. 5, the zoom lens of Example 5 includes, in order from the object side, a first lens unit G1 having a positive refractive power, a second lens unit G2 having a negative refractive power, an aperture stop S, and a positive lens unit. A third lens group G3 having a refractive power of 4, a fourth lens group G4 having a positive refractive power, and a fifth lens group G5 having a positive refractive power.

  The first lens group G1 includes a prism L1 having a concave object side surface and a flat image surface, a cemented lens (lens component C1p) of a biconvex positive lens L2 and a biconcave negative lens L3, and a convex surface facing the object side. The positive meniscus lens L4 has a positive refractive power as a whole.

  In this embodiment, f12 is the combined focal length of the lens L2, the lens L3, and the lens L4. Further, the surface apex Ct1 is the surface apex of the object side surface of the prism L1, and the surface apex Ct2 is the apex of the cemented surface of the cemented lens (lens L2 and lens L3).

  The second lens group G2 includes a cemented lens of a biconcave negative lens L5, a biconcave negative lens L6, and a positive meniscus lens L7 having a convex surface directed toward the object side, and has a negative refracting power as a whole. .

  The third lens group G3 includes a biconvex positive lens L8, and a cemented lens of a biconvex positive lens L9 and a biconcave negative lens L10, and has a positive refractive power as a whole.

  The fourth lens group G4 is a positive meniscus lens L11 having a convex surface directed toward the object side, and has a positive refractive power.

  The fifth lens group G5 includes a cemented lens which is formed by a negative meniscus lens L12 having a convex surface directed toward the object side and a biconvex positive lens L13, and has a positive refracting power as a whole.

  During zooming from the wide angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 moves to the image side, the third lens group G3 moves to the object side, and the fourth lens group G4. Moves to the image side, and the fifth lens group G5 is fixed. The position of the aperture stop S is fixed. The light amount is adjusted by changing the aperture size of the aperture stop S.

  The aspherical surfaces are a convex surface on the object side of the prism L1 having a concave surface on the object side of the first lens group G1 and a flat image surface, both surfaces of the biconvex positive lens L2, and a biconvex surface on the object side of the third lens group G3. It is provided on a total of six surfaces including both surfaces of the positive lens L8 and the object side surface of the positive meniscus lens L11 having a convex surface facing the object side of the fourth lens group G4.

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

  12A and 12B are diagrams showing spherical aberration, astigmatism, distortion aberration, and chromatic aberration of magnification when the zoom lens according to Example 6 is focused on an object point at infinity, where FIG. 12A is a wide angle end, and FIG. 12B is an intermediate focus. The distance state, (c) shows the state at the telephoto end.

  As shown in FIG. 11, the zoom lens of Example 6 includes, in order from the object side, a first lens unit G1 having a positive refractive power, a second lens unit G2 having a negative refractive power, an aperture stop S, and a positive lens unit. A third lens group G3 having a negative refractive power, a fourth lens group G4 having a positive refractive power, a fifth lens group G5 having a positive refractive power, and a sixth lens group G6 having a negative refractive power. .

  The first lens group G1 includes a negative meniscus lens L1 having a convex surface facing the object side, a prism L2 having both the object side surface and the image side surface being flat, and a negative meniscus lens L3 having a convex surface facing the object side. It consists of a cemented lens (lens component C1p) of the convex positive lens L4 and a biconvex positive lens L5, and has a positive refractive power as a whole.

  In this embodiment, f12 is the combined focal length of the lens L3, the lens L4, and the lens L5. Further, the surface top Ct1 is the surface top of the image side surface of the lens L1, and the surface top Ct2 is the surface top of the cemented surface of the cemented lens (lens L3 and lens L4).

  The second lens group G2 includes a cemented lens of a biconcave negative lens L6, a biconcave negative lens L7, and a positive meniscus lens L8 having a convex surface directed toward the object side, and has a negative refracting power as a whole. .

  The third lens group G3 includes a biconvex positive lens L9, and has positive refractive power.

  The fourth lens group G4 includes a biconvex positive lens L10, and a cemented lens of a biconvex positive lens L11 and a biconcave negative lens L12, and has a positive refractive power.

The fifth lens group G5 includes a biconvex positive lens L13, and has positive refractive power.
The sixth lens group G6 includes a cemented lens including a negative meniscus lens L14 having a convex surface directed toward the image side and a positive meniscus lens L15 having a convex surface directed toward the image side, and has a negative refractive power.

  At the time of zooming from the wide-angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 is moved to the image side, the third lens group G3 is fixed, and the fourth lens group G4 is an object. The fifth lens group G5 moves to the object side, then moves to the image side, and the sixth lens group G6 is fixed. The position of the aperture stop S is fixed. The light amount is adjusted by changing the opening size.

  The aspherical surface includes an object side surface of a negative meniscus lens L3 having a convex surface facing the object side of the first lens group G1, both surfaces of a biconvex positive lens L4, and a biconcave negative lens L7 on the image side of the second lens group G2. , The image side surface of the positive meniscus lens L8 with the convex surface facing the object side, both surfaces of the object side biconvex positive lens L10 of the fourth lens group G4, and the biconvex positive lens L13 of the fifth lens group G5. Are provided on a total of nine surfaces on the object side.

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

  14A and 14B are diagrams showing spherical aberration, astigmatism, distortion aberration, and chromatic aberration of magnification when the zoom lens according to Example 7 is focused on an object point at infinity, where FIG. 14A is a wide angle end, and FIG. 14B is an intermediate focus. The distance state, (c) shows the state at the telephoto end.

  As shown in FIG. 14, the zoom lens according to the seventh embodiment includes, in order from the object side, a first lens unit G1 having a positive refractive power, a second lens unit G2 having a negative refractive power, an aperture stop S, and a positive lens unit. A third lens group G3 having a negative refractive power, a fourth lens group G4 having a positive refractive power, and a fifth lens group G5 having a negative refractive power.

  The first lens group G1 includes a negative meniscus lens L1 having a convex surface directed toward the object side, a prism L2 having both an object-side surface and an image-side surface planar, and a biconvex positive lens L3 and a convex surface directed toward the image side. It is composed of a cemented lens (lens component C1p) of the negative meniscus lens L4, and has a positive refractive power as a whole.

  In this embodiment, f12 is the combined focal length of the lens L3 and the lens L4. Further, the surface top Ct1 is the surface top of the image side surface of the lens L1, and the surface top Ct2 is the surface top of the cemented surface of the cemented lens (lens L3 and lens L4).

  The second lens group G2 includes a biconcave negative lens L5, and a cemented lens of a biconcave negative lens L6 and a biconvex positive lens L7, and has a negative refracting power as a whole.

  The third lens group G3 includes a biconvex positive lens L8, and has positive refractive power.

  The fourth lens group G4 includes a cemented lens which is formed by a biconvex positive lens L9 and a negative meniscus lens L10 having a convex surface directed toward the image side, and has a positive refractive power.

  The fifth lens group G5 includes a biconcave negative lens L11 and a positive meniscus lens L12 having a convex surface directed toward the object side, and has negative refracting power.

  At the time of zooming from the wide-angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 is moved to the image side, the third lens group G3 is fixed, and the fourth lens group G4 is an object. The fifth lens group G5 is fixed. The position of the aperture stop S is fixed. The light amount is adjusted by changing the aperture size of the aperture stop S.

  The aspheric surfaces are both surfaces of the biconvex positive lens L3 of the first lens group G1, the object side surface of the convex positive lens L8 of the third lens group G3, and the object side of the biconvex positive lens L9 of the fourth lens group G4. And a surface on the object side of the negative negative lens L11 of the fifth lens group G5 and a surface on the object side of the positive meniscus lens L12 having a convex surface facing the object side.

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

  FIG. 16 is a diagram illustrating spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 8 is focused on an object point at infinity, where (a) is a wide angle end and (b) is an intermediate focus. The distance state, (c) shows the state at the telephoto end.

  As shown in FIG. 16, the zoom lens according to the eighth embodiment includes, in order from the object side, a first lens unit G1 having a positive refractive power, a second lens unit G2 having a negative refractive power, an aperture stop S, and a positive lens unit. A third lens group G3 having a refractive power of 4, a fourth lens group G4 having a positive refractive power, and a fifth lens group G5 having a positive refractive power.

  The first lens group G1 includes a negative meniscus lens L1 having a convex surface facing the object side, a prism L2 having both the object side surface and the image side surface being flat, and a negative meniscus lens L3 having a convex surface facing the object side. It is composed of a cemented lens (lens component C1p) of a convex positive lens L4, and has a positive refractive power as a whole.

  In this embodiment, f12 is the combined focal length of the lens L3 and the lens L4. Further, the surface top Ct1 is the surface top of the image side surface of the lens L1, and the surface top Ct2 is the surface top of the cemented surface of the cemented lens (lens L3 and lens L4).

  The second lens group G2 includes a cemented lens of a biconcave negative lens L5, a biconcave negative lens L6, a biconcave negative lens L7, and a positive meniscus lens L8 having a convex surface facing the object side. Has refractive power.

  The third lens group G3 includes a biconvex positive lens L9, and has positive refractive power.

  The fourth lens group G4 includes a cemented lens which is formed by a biconvex positive lens L10 and a negative meniscus lens L11 having a convex surface directed toward the image side, and has a positive refractive power.

  The fifth lens group G5 includes a biconcave negative lens L12 and a biconvex positive lens L13, and has positive refracting power.

  At the time of zooming from the wide-angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 is moved to the image side, the third lens group G3 is fixed, and the fourth lens group G4 is an object. The fifth lens group G5 is fixed. The position of the aperture stop S is fixed. The light amount is adjusted by changing the aperture size of the aperture stop S.

  The aspherical surfaces are the object side surface of the negative meniscus lens L3 with the convex surface facing the object side of the first lens group G1, both surfaces of the biconvex positive lens L4, and the object side of the convex positive lens L9 of the third lens group G3. A total of six surfaces are provided, that is, the object side surface of the biconvex positive lens L10 of the fourth lens group G4 and the object side surface of the biconvex positive lens L13 of the fifth lens group G5.

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

  18A and 18B are diagrams illustrating spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 9 is focused on an object point at infinity, in which FIG. 18A is a wide angle end, and FIG. 18B is an intermediate focus. The distance state, (c) shows the state at the telephoto end.

  As shown in FIG. 17, the zoom lens according to the ninth embodiment includes, in order from the object side, a first lens unit G1 having a positive refractive power, a second lens unit G2 having a negative refractive power, an aperture stop S, and a positive lens unit. A third lens group G3 having a negative refractive power, a fourth lens group G4 having a positive refractive power, and a fifth lens group G5 having a negative refractive power.

  The first lens group G1 includes a negative meniscus lens L1 having a convex surface facing the object side, a prism L2 having both the object side surface and the image side surface being flat, and a negative meniscus lens L3 having a convex surface facing the object side. It is composed of a cemented lens (lens component C1p) of a convex positive lens L4, and has a positive refractive power as a whole.

  In this embodiment, f12 is the combined focal length of the lens L3 and the lens L4. Further, the surface top Ct1 is the surface top of the image side surface of the lens L1, and the surface top Ct2 is the surface top of the cemented surface of the cemented lens (lens L3 and lens L4).

  The second lens group G2 includes a biconcave negative lens L5, a cemented lens of a biconcave negative lens L6, a positive meniscus lens L7 having a convex surface directed toward the object side, and a biconcave negative lens L8. Has refractive power.

  The third lens group G3 includes a biconvex positive lens L9, and has positive refractive power.

  The fourth lens group G4 includes a cemented lens which is formed by a biconvex positive lens L10 and a negative meniscus lens L11 having a convex surface directed toward the image side, and has a positive refractive power.

  The fifth lens group G5 includes a biconcave negative lens L12 and a positive meniscus lens L13 having a convex surface directed toward the object side, and has negative refracting power.

  At the time of zooming from the wide-angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 is moved to the image side, the third lens group G3 is fixed, and the fourth lens group G4 is an object. The fifth lens group G5 is fixed. The position of the aperture stop S is fixed. The light amount is adjusted by changing the aperture size of the aperture stop S.

  The aspherical surfaces are the object side surface of the negative meniscus lens L3 with the convex surface facing the object side of the first lens group G1, both surfaces of the biconvex positive lens L4, and the object side of the convex positive lens L9 of the third lens group G3. A total of six surfaces are provided, that is, the object side surface of the biconvex positive lens L10 of the fourth lens group G4 and the object side surface of the biconvex positive lens L13 of the fifth lens group G5.

Below, the numerical data of each said Example are shown. Symbol is outside the above, f is the focal length of the entire system, BF is the back focus, f is the focal length of each lens group, IH is the image height, _FNO is the F number, ω is the half field angle, WE is the wide angle end, ST Is the intermediate focal length state, TE is the telephoto end, r is the radius of curvature of each lens surface, d is the distance between the lens surfaces, nd is the refractive index of the d-line of each lens, and νd is the Abbe number of each lens. The total lens length described later is obtained by adding back focus to the distance from the lens front surface to the lens final surface. BF (back focus) represents the distance from the last lens surface to the paraxial image plane in terms of air.

  The aspherical shape is expressed by the following formula, where z is an optical axis with the light traveling direction being positive, and y is a direction orthogonal to the optical axis.

z = h ² / R [1+ {1− (K + 1) h ² / R ² } ^1/2 ]
+ A ₄ h ⁴ + A ₆ h ⁶ + A ₈ h ⁸ + A ₁₀ h ¹⁰ + A ₁₂ h ¹²
Where r is the paraxial radius of curvature, K is the conic coefficient, and A ₄ , A ₆ , A ₈ , A ₁₀ , and A ₁₂ are the fourth, sixth, eighth, tenth, and twelfth aspheric coefficients, respectively. . In the aspheric coefficient, “e−n” (n is an integer) indicates “10 ⁻ⁿ ”.

Numerical example 1
Unit mm

Surface data surface number rd nd νd
Object ∞ ∞
1 35.6078 1.0000 2.14352 17.77
2 13.3707 2.8000
3 ∞ 10.8000 1.80610 40.92
4 ∞ 0.2000
5 * 18.8067 2.8000 1.88300 40.76
6 * -17.6140 0.1000 1.63494 23.22
7 * -36.1413 Variable
8 85.6702 0.5000 1.83481 42.71
9 * 10.5788 1.5000
10 -13.5398 0.5000 1.80610 40.92
11 14.0475 1.4000 1.94595 17.98
12 -98.7614 Variable
13 (STO) ∞ Variable
14 * 8.0967 2.5000 1.83481 42.71
15 * -33.6397 0.1500
16 9.2703 1.6000 1.69680 55.53
17 -180.4104 0.5000 2.00069 25.46
18 5.4518 Variable
19 * 9.3913 1.6000 1.52540 56.25
20 36.3345 Variable
21 * -15.8203 0.6000 2.14352 17.77
22 26.9859 2.2000 1.48749 70.23
23 -7.5455 0.6000
24 ∞ 0.8000 1.51633 64.14
25 ∞ 0.7999
Image plane ∞

Aspheric data 5th surface
K = 0.0656,
A2 = 0.0000E + 00, A4 = -2.0793E-05, A6 = -2.2718E-07, A8 = -1.4970E-08, A10 = 0.0000E + 00
6th page
K = 0.0281,
A2 = 0.0000E + 00, A4 = -1.6543E-05, A6 = -1.9504E-06, A8 = 4.1524E-08, A10 = 0.0000E + 00
7th page
K = -0.0404,
A2 = 0.0000E + 00, A4 = 3.7765E-05, A6 = 2.1488E-07, A8 = -3.4001E-08, A10 = 0.0000E + 00
9th page
K = -0.9588,
A2 = 0.0000E + 00, A4 = 1.4918E-04, A6 = 3.3691E-06, A8 = 2.7367E-07, A10 = 0.0000E + 00
14th page
K = -0.6078,
A2 = 0.0000E + 00, A4 = -7.2844E-05, A6 = 4.9099E-06, A8 = 5.9322E-08, A10 = 0.0000E + 00
15th page
K = -0.1929,
A2 = 0.0000E + 00, A4 = 7.6881E-05, A6 = 7.5157E-06, A8 = -1.3516E-08, A10 = 0.0000E + 00
19th page
K = 0.0285,
A2 = 0.0000E + 00, A4 = -2.5544E-04, A6 = 1.4559E-05, A8 = -6.7788E-07, A10 = 0.0000E + 00
21st page
K = 0.2758,
A2 = 0.0000E + 00, A4 = 1.6010E-04, A6 = -2.5583E-05, A8 = 9.6944E-07, A10 = 0.0000E + 00

Various data zoom ratio 4.95
Wide angle Medium telephoto focal length 6.05071 13.53489 29.95978
F number 3.0985 4.1877 5.9000
Angle of view 36.8 ° 16.0 ° 7.2 °
Image height 3.84 3.84 3.84
Total lens length 61.0001 61.0005 61.0000
BF 0.79995 0.79995 0.79995

d7 0.59941 5.39336 9.12734
d12 9.92807 5.13508 1.40013
d13 9.23970 5.05720 1.19996
d18 3.05832 7.23901 14.82278
d20 5.22463 5.22595 1.49990

Zoom lens group data group Start surface Focal length
1 1 16.31490
2 8 -8.97530
3 14 13.65900
4 19 23.62172
5 21 -45.67590

[Glass Material Refractive Index Table] ... Refractive index list by wavelength of medium used in this example
GLA 587.56 656.27 486.13 435.84 404.66
L4 1.634937 1.627308 1.654649 1.671136 1.685842 (LA)
L7 1.945950 1.931230 1.983830 2.018254 2.051060
L1, L12 2.143520 2.125601 2.189954 2.232324 2.273184
L14 1.516330 1.513855 1.521905 1.526213 1.529768
L13 1.487490 1.485344 1.492285 1.495963 1.498983
L2, L6 1.806098 1.800248 1.819945 1.831173 1.840781
L5, L8 1.834807 1.828975 1.848520 1.859547 1.868911
L3 1.882997 1.876560 1.898221 1.910495 1.920919 (LB)
L9 1.696797 1.692974 1.705522 1.712339 1.718005
L10 2.000690 1.989410 2.028720 2.052834 2.074600
L11 1.525400 1.522460 1.531800 1.537220 1.543548

Numerical example 2
Unit mm

Surface number rd nd νd
Object ∞ ∞
1 157.7080 1.0000 2.00330 28.27
2 13.4226 1.7000
3 ∞ 9.8000 2.14352 17.7
4 ∞ 0.2000
5 * 35.3820 2.5000 1.74320 49.34
6 * -13.8568 0.1000 1.63494 23.22
7 * -24.8919 0.1500
8 18.7117 1.8000 1.81600 46.62
9 -989.9236 Variable
10 -35.1124 0.5000 1.83481 42.71
11 * 11.2710 1.1000
12 -16.1577 0.5000 1.80610 40.92
13 9.1476 1.3000 1.94595 17.98
14 137.0310 Variable
15 (STO) ∞ Variable
16 * 6.0346 2.5000 1.83481 42.71
17 * -20.8366 0.1500
18 13.2227 1.6000 1.69680 55.53
19 -21.0493 0.5000 2.00069 25.46
20 4.2655 Variable
21 * 10.9804 1.6000 1.52540 56.25
22 -232.4414 Variable
23 -362.5642 0.6000 2.04300 39.00
24 14.2643 3.0000 1.51742 52.43
25 -10.6048 0.6000
26 ∞ 0.8000 1.51633 64.14
27 ∞ 0.7993
Image plane ∞

Aspheric data 5th surface
K = -0.3278,
A2 = 0.0000E + 00, A4 = 2.9173E-06, A6 = -2.0925E-06, A8 = 4.2530E-08, A10 = 0.0000E + 00
6th page
K = 0.0479,
A2 = 0.0000E + 00, A4 = 4.8113E-05, A6 = -1.1149E-05, A8 = 3.7818E-07, A10- = 0.0000E + 00
7th page
K = -0.0187,
A2 = 0.0000E + 00, A4 = -7.3529E-06, A6 = -6.6541E-07, A8 = -1.3661E-08, A10 = 0.0000E + 00
11th page
K = -0.8871,
A2 = 0.0000E + 00, A4 = 5.3951E-05, A6 = 5.7536E-06, A8 = 6.4825E-09, A10 = 0.0000E + 00
16th page
K = -0.5942,
A2 = 0.0000E + 00, A4 = -6.8115E-05, A6 = 1.0907E-07, A8 = 7.4120E-08, A10 = 0.0000E + 00
17th page
K = -0.7628,
A2 = 0.0000E + 00, A4 = 4.5611E-04, A6 = -1.0355E-05, A8 = 3.5572E-07, A10 = 0.0000E + 00
21st page
K = -0.7169,
A2 = 0.0000E + 00, A4 = 2.7279E-05, A6 = -5.1868E-06, A8 = 1.8491E-08, A10 = 0.0000E + 00

Various data zoom ratio 4.94
Wide angle Medium telephoto focal length 6.06124 13.53624 29.95741
F number 3.6364 3.9517 5.9000
Angle of view 36.7 ° 15.5 ° 7.2 °
Image height 3.84 3.84 3.84
Total lens length 58.0640 58.0714 58.0645
BF 0.79928 0.79928 0.79928

d9 0.59769 5.73203 8.08721
d14 8.88866 3.77014 1.39890
d15 6.82073 5.76455 1.19484
d20 3.98911 4.58771 13.08294
d22 4.96853 5.41533 1.50088

Zoom lens group data group Start surface Focal length
1 1 12.81116
2 10 -6.90346
3 16 12.76421
4 21 20.00160
5 23 77.44170

[Glass Material Refractive Index Table] ... Refractive index list by wavelength of medium used in this example
GLA 587.56 656.27 486.13 435.84 404.66
L4 1.634937 1.627308 1.654649 1.672358 1.688773 (LA)
L13 2.042998 2.035064 2.061804 2.076930 2.089693
L8 1.945950 1.931230 1.983830 2.018254 2.051063
L2 2.143520 2.125601 2.189954 2.232324 2.273190
L15 1.516330 1.513855 1.521905 1.526213 1.529768
L7 1.806098 1.800248 1.819945 1.831173 1.840781
L6, L9 1.834807 1.828975 1.848520 1.859547 1.868911
L5 1.816000 1.810749 1.828252 1.837996 1.846185
L1 2.003300 1.993011 2.028497 2.049714 2.068441
L10 1.696797 1.692974 1.705522 1.712339 1.718005
L3 1.743198 1.738653 1.753716 1.762046 1.769040 (LB)
L14 1.517417 1.514444 1.524313 1.529804 1.534439
L11 2.000690 1.989410 2.028720 2.052834 2.074603
L12 1.525400 1.522460 1.531800 1.537220 1.543549

Numerical Example 3
Unit mm

Surface data surface number rd nd νd
Object ∞ ∞
1 42.7993 1.0000 2.14352 17.77
2 14.3967 3.0000
3 ∞ 11.5000 1.80610 40.92
4 -33.4852 0.2000
5 * 41.1895 0.1000 1.63494 23.22
6 * 14.8052 2.8000 2.04300 39.00
7 * -77.3252 Variable
8 28.7788 0.5000 1.83481 42.71
9 * 11.1439 1.5000
10 -13.1774 0.5000 1.80610 40.92
11 7.5542 1.7000 1.94595 17.98
12 29.7930 Variable
13 (STO) ∞ Variable
14 * 7.0815 2.5000 1.83481 42.71
15 * -26.0758 0.1500
16 9.8333 1.6000 1.69680 55.53
17 -52.8726 0.5000 2.00069 25.46
18 4.7458 Variable
19 * 8.0689 1.6000 1.52540 56.25
20 19.5088 Variable
21 -21.4768 0.6000 2.14352 17.77
22 29.6499 2.5000 1.48749 70.23
23 * -6.3895 0.6000
24 ∞ 0.8000 1.51633 64.14
25 ∞ 0.7998
Image plane ∞

Aspheric data 5th surface
K = -0.1513,
A2 = 0.0000E + 00, A4 = -3.7050E-05, A6 = 1.0839E-07, A8 = 1.1477E-08, A10 = 0.0000E + 00
6th page
K = 0.0263,
A2 = 0.0000E + 00, A4 = 8.6520E-05, A6 = 4.5524E-07, A8 = -1.3742E-08, A10 = 0.0000E + 00
7th page
K = -0.0789,
A2 = 0.0000E + 00, A4 = 1.3315E-05, A6 = 1.7773E-07, A8 = 1.4417E-09, A10 = 0.0000E + 00
9th page
K = -0.9593,
A2 = 0.0000E + 00, A4 = 1.3958E-04, A6 = 3.2451E-06, A8 = 2.3083E-07, A10 = 0.0000E + 00
14th page
K = -0.6063,
A2 = 0.0000E + 00, A4 = -1.1098E-04, A6 = 3.2759E-06, A8 = -2.4822E-07, A10 = 0.0000E + 00
15th page
K = -0.2754,
A2 = 0.0000E + 00, A4- = 1.4957E-04, A6 = 1.3647E-06, A8 = -2.3821E-07, A10 = 0.0000E + 00
19th page
K = 0.1053,
A2 = 0.0000E + 00, A4 = -3.5906E-04, A6 = 7.5775E-06, A8 = -7.2931E-07, A10 = 0.0000E + 00
23rd page
K = -0.0104,
A2 = 0.0000E + 00, A4 = 8.9487E-04, A6 = -2.2954E-05, A8 = 4.3482E-08, A10 = 0.0000E + 00

Various data zoom ratio 5.00
Wide angle Medium telephoto focal length 6.20326 13.89999 30.99937
F number 3.2355 3.8924 5.9000
Angle of view 36.1 ° 15.4 ° 7.0 °
Image height 3.84 3.84 3.84
Total lens length 60.6722 60.6724 60.6722
BF 0.79981 0.79981 0.79981

d7 0.59924 5.69519 8.45116
d12 9.25207 4.15538 1.40014
d13 8.59216 6.20722 1.19945
d18 2.57430 4.59337 13.17083
d20 5.20465 5.56496 2.00091

Zoom lens group data group Start surface Focal length
1 1 15.12158
2 8 -7.86841
3 14 12.90647
4 19 24.98639
5 21 87.42192

[Glass Material Refractive Index Table] ... Refractive index list by wavelength of medium used in this example
GLA 587.56 656.27 486.13 435.84 404.66
L4 2.042998 2.035064 2.061804 2.076930 2.089691 (LB)
L3 1.634937 1.627308 1.654649 1.670616 1.684505 (LA)
L7 1.945950 1.931230 1.983830 2.018254 2.051060
L1, L12 2.143520 2.125601 2.189954 2.232324 2.273184
L14 1.516330 1.513855 1.521905 1.526213 1.529768
L13 1.487490 1.485344 1.492285 1.495963 1.498983
L2, L6 1.806098 1.800248 1.819945 1.831173 1.840781
L5, L8 1.834807 1.828975 1.848520 1.859547 1.868911
L9 1.696797 1.692974 1.705522 1.712339 1.718005
L10 2.000690 1.989410 2.028720 2.052834 2.074600
L11 1.525400 1.522460 1.531800 1.537220 1.543548

Numerical Example 4
Unit mm

Surface number rd nd νd
Object ∞ ∞
1 48.8438 1.0000 2.14352 17.77
2 * 11.8544 2.8000
3 -29.7268 9.8000 2.14352 17.77
4 ∞ 0.2000
5 17.3005 2.7000 1.75520 27.51
6 -47.1388 0.1500
7 * 13.0396 3.0000 1.80610 40.92
8 * -36.7988 0.1000 1.67000 19.30
9 * 91.5078 variable
10 -78.7741 0.5000 1.83481 42.71
11 * 10.2672 1.1000
12 -14.0949 0.5000 1.72916 54.68
13 8.2918 1.3000 1.94595 17.98
14 27.2540 Variable
15 (STO) ∞ Variable
16 * 7.6801 3.9828 1.83481 42.71
17 * -64.2740 0.1500
18 8.2756 2.1000 1.69680 55.53
19 -14.4365 0.5000 2.00069 25.46
20 5.9078 Variable
21 * 8.7416 1.5000 1.52540 56.25
22 24.6527 Variable
23 81.0820 0.6000 2.14352 17.77
24 10.8703 3.1000 1.48749 70.23
25 * -8.3023 0.6000
26 ∞ 0.8000 1.51633 64.14
27 ∞ 0.4999
Image plane ∞

Aspheric data 2nd surface
K = 0.0498,
A2 = 0.0000E + 00, A4 = -1.3925E-04, A6 = 2.8042E-07, A8 = -1.1379E-08, A10 = 0.0000E + 00
7th page
K = 0.0272,
A2 = 0.0000E + 00, A4 = -5.4638E-05, A6 = 1.9698E-06, A8 = -1.6771E-08, A10 = 0.0000E + 00
8th page
K = 0.0936,
A2 = 0.0000E + 00, A4 = -1.1220E-04, A6 = 1.6578E-06, A8 = 8.9828E-08, A10 = 0.0000E + 00
9th page
K = 0.5504,
A2 = 0.0000E + 00, A4 = 1.1911E-04, A6 = 4.6910E-06, A8 = -9.1582E-08, A10 = 0.0000E + 00
11th page
K = -0.8331,
A2 = 0.0000E + 00, A4 = 2.2507E-04, A6 = -7.1701E-07, A8 = 1.4359E-06, A10 = 0.0000E + 00
16th page
K = -0.5705,
A2 = 0.0000E + 00, A4 = 2.6285E-04, A6 = 1.6592E-05, A8 = -1.1215E-07, A10 = 0.0000E + 00
17th page
K = -0.7197,
A2 = 0.0000E + 00, A4 = 6.4343E-04, A6 = 2.1920E-05, A8 = 8.2869E-07, A10 = 0.0000E + 00
21st page
K = -0.7247,
A2 = 0.0000E + 00, A4 = -3.4170E-04, A6 = 1.6958E-05, A8 = -1.9597E-06, A10 = 0.0000E + 00
25th page
K = 0.0433,
A2 = 0.0000E + 00, A4 = -9.4693E-04, A6 = 9.5646E-05, A8 = -4.1316E-06, A10 = 0.0000E + 00

Various data zoom ratio 4.99
Wide angle Medium telephoto focal length 5.00516 11.17413 24.99304
F number 3.6331 3.9510 5.9000
Angle of view 43.4 ° 19.0 ° 8.6 °
Image height 3.84 3.84 3.84
Total lens length 59.9108 59.9147 59.9110
BF 0.49986 0.49986 0.49986

d9 0.79553 5.59358 7.88345
d14 8.47749 3.69199 1.38960
d15 6.09817 5.31356 1.19254
d20 3.18290 2.98040 10.95933
d22 4.37407 5.31520 1.50350

Zoom lens group data group Start surface Focal length
1 1 10.60778
2 10 -6.17835
3 16 11.19498
4 21 24.96809
5 23 55.22906

[Glass Material Refractive Index Table] ... Refractive index list by wavelength of medium used in this example
GLA 587.56 656.27 486.13 435.84 404.66
L5 1.669997 1.660518 1.695229 1.714216 1.732297 (LA)
L8 1.945950 1.931230 1.983830 2.018254 2.051063
L1, L2, L13 2.143520 2.125601 2.189954 2.232324 2.273190
L15 1.516330 1.513855 1.521905 1.526213 1.529768
L14 1.487490 1.485344 1.492285 1.495963 1.498983
L4 1.806098 1.800248 1.819945 1.831173 1.840781 (LB)
L6, L9 1.834807 1.828975 1.848520 1.859547 1.868911
L10 1.696797 1.692974 1.705522 1.712339 1.718005
L7 1.729157 1.725101 1.738436 1.745696 1.751731
L3 1.755199 1.747295 1.774745 1.791495 1.806556
L11 2.000690 1.989410 2.028720 2.052834 2.074603
L12 1.525400 1.522460 1.531800 1.537220 1.543549

Numerical Example 5
Unit mm

Surface number rd nd νd
Object ∞ ∞
1 * -17.1748 10.3000 2.14352 17.77
2 ∞ 0.200
3 * 16.7286 2.3000 1.80610 40.92
4 * -53.6680 0.1000 1.63494 23.22
5 3204.9577 0.1500
6 14.7128 1.6000 1.90366 31.32
7 82.2131 Variable
8 -1.984E + 04 0.5000 1.83481 42.71
9 11.0784 1.6000
10 -9.1210 0.5000 1.72916 54.68
11 13.2632 1.2000 1.94595 17.98
12 281.7281 Variable
13 (STO) ∞ Variable
14 * 5.7953 2.5000 1.83481 42.71
15 * -18.0769 0.1500
16 11.1053 1.7000 1.69680 55.53
17 -16.6710 0.5000 2.00069 25.46
18 3.7744 Variable
19 * 9.8539 1.6000 1.52540 56.25
20 37.3912 Variable
21 16.0798 0.6000 2.00330 28.27
22 5.6360 3.0000 1.51633 64.14
23 -10.5926 0.6000
24 ∞ 0.8000 1.51633 64.14
25 ∞ 0.5016
Image plane ∞

Aspheric data 1st surface
K = -0.0366,
A2 = 0.0000E + 00, A4 = 2.3100E-04, A6 = -2.3544E-06, A8 = 2.5544E-08, A10 = -1.1763E-10
Third side
K = -0.0300,
A2 = 0.0000E + 00, A4 = -2.7534E-04, A6 = 3.1374E-06, A8 = -8.4181E-09, A10 = 0.0000E + 00
4th page
K = 0.0011,
A2 = 0.0000E + 00, A4 = -4.5516E-04, A6 = 9.8020E-06, A8 = -8.5631E-09, A10 = 0.0000E + 00
14th page
K = -0.5838,
A2 = 0.0000E + 00, A4 = -1.2310E-04, A6 = -1.3763E-06, A8 = 2.1745E-07, A10 = 0.0000E + 00
15th page
K = -0.7838,
A2 = 0.0000E + 00, A4 = 5.7429E-04, A6 = -1.3882E-05, A8 = 4.2336E-07, A10 = 0.0000E + 00
19th page
K = -1.0645,
A2 = 0.0000E + 00, A4 = 5.9099E-04, A6 = -1.7414E-05, A8 = 3.6786E-07, A10 = 0.0000E + 00

Various data zoom ratio 4.93
Wide angle Medium telephoto focal length 6.07178 13.52809 29.95461
F number 3.3875 4.0537 5.9000
Angle of view 37.7 ° 15.5 ° 7.4 °
Image height 3.84 3.84 3.84
Total lens length 52.9041 52.9251 52.9047
BF 0.50159 0.50159 0.50159

d7 0.69477 5.06088 7.57328
d12 8.26624 3.90348 1.38895
d13 7.25378 5.35083 1.19238
d18 2.21643 3.17585 10.84933
d20 4.07132 5.06226 1.49915

Zoom lens group data group Start surface Focal length
1 1 14.32686
2 8 -6.66166
3 14 11.14998
4 19 24.96668
5 21 36.23308

[Glass Material Refractive Index Table] ... Refractive index list by wavelength of medium used in this example
GLA 587.56 656.27 486.13 435.84 404.66
L3 1.634937 1.627308 1.654649 1.670616 1.684505 (LA)
L7 1.945950 1.931230 1.983830 2.018254 2.051063
L1 2.143520 2.125601 2.189954 2.232324 2.273190
L13, L14 1.516330 1.513855 1.521905 1.526213 1.529768
L2 1.806098 1.800248 1.819945 1.831173 1.840781 (LB)
L5, L8 1.834807 1.828975 1.848520 1.859547 1.868911
L12 2.003300 1.993011 2.028497 2.049714 2.068441
L9 1.696797 1.692974 1.705522 1.712339 1.718005
L6 1.729157 1.725101 1.738436 1.745696 1.751731
L4 1.903660 1.895260 1.924120 1.941280 1.956428
L10 2.000690 1.989410 2.028720 2.052834 2.074603
L11 1.525400 1.522460 1.531800 1.537220 1.543549

Numerical Example 6
Unit mm

Surface data surface number rd nd νd
Object ∞ ∞
1 26.8861 1.0000 2.14352 17.77
2 10.4019 2.0000
3 ∞ 9.8000 2.14352 17.77
4 ∞ 0.2000
5 * 43.1266 0.1000 1.63494 23.22
6 * 23.3838 2.4000 1.80610 40.92
7 * -29.3975 0.1500
8 19.1461 1.8000 1.80610 40.92
9 -118.3339 Variable
10 -33.0995 0.5000 1.81600 46.62
11 11.0007 0.9000
12 * -14.1728 0.6000 1.69350 53.21
13 * 8.6979 0.5000 1.73000 16.50
14 * 41.5907 Variable
15 (STO) ∞ 0.7000
16 23.2704 1.0000 1.58913 61.14
17 -39.5668 Variable
18 * 9.3228 2.5000 1.83481 42.71
19 * -35.2849 0.1500
20 16.5137 1.6000 1.69680 55.53
21 -18.9795 0.5000 2.00069 25.46
22 7.8715 Variable
23 * 11.9382 1.6000 1.52540 56.25
24 -81.9589 Variable
25 -7.8192 0.6000 2.14352 17.77
26 -15.1015 2.0000 1.51633 64.14
27 -7.1048 0.6000
28 ∞ 0.8000 1.51633 64.14
29 ∞ 0.8002
Image plane ∞

Aspheric data 5th surface
K = -0.3198,
A2 = 0.0000E + 00, A4 = 7.0812E-05, A6 = -3.7266E-06, A8 = 5.5289E-08, A10 = 0.0000E + 00
6th page
K = 0.0895,
A2 = 0.0000E + 00, A4 = -1.2037E-04, A6 = 9.9952E-06, A8 = -2.5704E-07, A10 = 0.0000E + 00
7th page
K = -0.0600, A2 = 0.0000E + 00, A4 = 9.3083E-06, A6 = -8.5596E-07, A8 = -1.1449E-08, A10 = 0.0000E + 00
12th page
K = -0.3180,
A2 = 0.0000E + 00, A4 = 1.0698E-03, A6 = -1.4595E-04, A8 = 7.0190E-06, A10 = 0.0000E + 00
Side 13
K = -1.0000,
A2 = 0.0000E + 00, A4 = 2.0000E-04, A6 = 0.0000E + 00, A8 = 0.0000E + 00, A10 = 0.0000E + 00
14th page
K = 2.4959,
A2 = 0.0000E + 00, A4 = 7.8292E-04, A6 = -1.1366E-04, A8 = 6.5409E-06, A10 = 0.0000E + 00
18th page
K = -0.5894,
A2 = 0.0000E + 00, A4 = 7.7905E-05, A6 = 1.1782E-05, A8 = -2.0278E-07, A10 = 0.0000E + 00
19th page
K = -0.7348,
A2 = 0.0000E + 00, A4 = 2.8188E-04, A6 = 9.8333E-06, A8 = -1.0652E-07, A10 = 0.0000E + 00
23rd page
K = -0.6984,
A2 = 0.0000E + 00, A4 = -1.3174E-05, A6 = 9.8051E-06, A8 = -2.7387E-07, A10 = 0.0000E + 00

Various data zoom ratio 4.95
Wide angle Medium telephoto focal length 6.05277 13.53390 29.95828
F number 4.0425 4.5176 6.0291
Angle of view 38.4 ° 16.0 ° 7.2 °
Image height 3.84 3.84 3.84
Total lens length 58.2782 58.2843 58.2778
BF 0.80017 0.80017 0.80017

d9 0.59649 5.36101 8.15085
d14 8.84912 4.09680 1.29474
d17 7.14286 4.64410 0.69974
d22 3.54736 4.87106 13.83328
d24 5.34215 6.51258 1.49937

Zoom lens group data group Start surface Focal length
1 1 12.85253
2 10 -5.91408
3 15 25.01936
4 18 21.07605
5 23 19.95023
6 25 -57.17262

[Glass Material Refractive Index Table] ... Refractive index list by wavelength of medium used in this example
GLA 587.56 656.27 486.13 435.84 404.66
L3 1.634937 1.627308 1.654649 1.672358 1.688773 (LA)
L8 1.729996 1.718099 1.762336 1.793147 1.822977
L1, L2, L14 2.143520 2.125601 2.189954 2.232324 2.273190
L9 1.589130 1.586188 1.595824 1.601033 1.605348
L15, L16 1.516330 1.513855 1.521905 1.526213 1.529768
L4, L5 1.806098 1.800248 1.819945 1.831173 1.840781 (LB)
L10 1.834807 1.828975 1.848520 1.859547 1.868911
L6 1.816000 1.810749 1.828252 1.837996 1.846185
L7 1.693501 1.689548 1.702582 1.709715 1.715662
L11 1.696797 1.692974 1.705522 1.712339 1.718005
L12 2.000690 1.989410 2.028720 2.052834 2.074603
L13 1.525400 1.522460 1.531800 1.537220 1.543549

Numerical Example 7
Unit mm

Surface number rd nd νd
Object ∞ ∞
1 26.3279 1.0000 2.14352 17.77
2 14.5172 1.8000
3 ∞ 9.5000 2.14352 17.77
4 ∞ 0.2000
5 * 11.2902 3.1000 1.74320 49.34
6 * -40.1582 0.1000 1.63494 23.22
7 -55.9920 Variable
8 -53.2497 0.5000 1.83481 42.71
9 6.4066 1.0000
10 -8.9690 0.5000 1.80610 40.92
11 5.7354 1.4000 1.80810 22.76
12 -89.8331 Variable
13 (STO) ∞ 0.8000
14 * 9.6873 1.5000 1.51633 64.14
15 -40.2680 Variable
16 * 22.9449 1.8000 1.74320 49.34
17 -8.4669 0.5000 1.80810 22.76
18 -12.3980 Variable
19 * -11.2318 0.6000 2.14352 17.77
20 89.5111 5.7315
21 * 5.3980 2.2000 1.48749 70.23
22 8.2670 Variable
23 ∞ 0.8000 1.51633 64.14
24 ∞ 0.7994
Image plane ∞

Aspheric data 5th surface
K = 0.0562,
A2 = 0.0000E + 00, A4 = -1.0635E-04, A6 = -3.3073E-07, A8 = -3.5038E-09, A10 = 0.0000E + 00
6th page
K = 0.6015,
A2 = 0.0000E + 00, A4 = -3.1085E-04, A6 = 3.6175E-06, A8 = -1.5913E-08, A10 = 0.0000E + 00
14th page
K = 0.0653,
A2 = 0.0000E + 00, A4 = -2.9532E-04, A6 = -3.6675E-06, A8 = 2.7757E-07, A10 = 0.0000E + 00
16th page
K = -0.0724,
A2 = 0.0000E + 00, A4 = -3.3421E-04, A6 = 5.5697E-06, A8 = -4.4877E-07, A10 = 0.0000E + 00
19th page
K = 0.0658,
A2 = 0.0000E + 00, A4 = 5.3557E-04, A6 = -1.9173E-05, A8 = 1.3380E-06, A10 = 0.0000E + 00
21st page
K = -0.0668,
A2 = 0.0000E + 00, A4 = -7.2957E-04, A6 = -1.1862E-05, A8 = -1.0182E-06, A10 = 0.0000E + 00

Various data zoom ratio 4.95
Wide angle Medium telephoto focal length 6.04854 13.53462 29.95479
F number 3.9500 4.2520 4.6745
Angle of view 36.8 ° 16.1 ° 7.2 °
Image height 3.84 3.84 3.84
Total lens length 56.0119 55.9997 56.0110
BF 0.79942 0.79942 0.79942

d7 0.60676 5.42276 8.83870
d12 9.63307 4.79110 1.40123
d15 5.10636 3.03570 1.28066
d18 4.37904 6.46010 8.20476
d22 2.45578 2.45578 2.45578

Zoom lens group data group Start surface Focal length
1 1 16.48040
2 8 -4.22240
3 13 15.27984
4 16 11.42447
5 19 -17.00590

[Glass Material Refractive Index Table] ... Refractive index list by wavelength of medium used in this example
GLA 587.56 656.27 486.13 435.84 404.66
L4 1.634937 1.627308 1.654649 1.670903 1.685230 (LA)
L1, L2, L11 2.143520 2.125601 2.189954 2.232324 2.273184
L8, L13 1.516330 1.513855 1.521905 1.526213 1.529768
L12 1.487490 1.485344 1.492285 1.495963 1.498983
L6 1.806098 1.800248 1.819945 1.831173 1.840781
L5 1.834807 1.828975 1.848520 1.859547 1.868911
L3, L9 1.743198 1.738653 1.753716 1.762046 1.769040 (LB)
L7, L10 1.808095 1.798009 1.833513 1.855902 1.876580

Numerical Example 8
Unit mm

Surface data surface number rd nd νd
Object ∞ ∞
1 31.5550 1.0000 2.00069 25.46
2 14.3812 1.9000
3 ∞ 9.5000 2.14352 17.77
4 ∞ 0.2000
5 * 13.3840 0.1000 1.63494 23.22
6 * 9.5949 2.8000 1.74320 49.34
7 * -33.9738 variable
8 -110.3976 0.5000 1.80400 46.57
9 13.9738 0.4000
10 -42.2586 0.5000 1.78800 47.37
11 21.6286 0.4000
12 -14.6928 0.5000 1.77250 49.60
13 4.6945 1.0000 1.80810 22.76
14 16.5493 Variable
15 (STO) ∞ 0.8000
16 * 11.7378 1.5000 1.51633 64.14
17 -40.2680 Variable
18 * 14.7240 2.2000 1.74320 49.34
19 -6.4219 0.5000 1.80810 22.76
20 -12.4275 Variable
21 -86.9726 0.6000 2.09500 29.40
22 8.1530 6.9787
23 * 7.8706 3.0000 1.52540 56.25
24 -31.6596 Variable
25 ∞ 0.8000 1.51633 64.14
26 ∞ 0.7994
Image plane ∞

Aspheric data 5th surface
K = 0.0342,
A2 = 0.0000E + 00, A4 = -5.1096E-05, A6 = 3.9696E-08, A8 = -1.1548E-08, A10 = 0.0000E + 00
6th page
K = 0.2138,
A2 = 0.0000E + 00, A4 = -8.0734E-05, A6 = -1.9246E-06, A8 = 0.0000E + 00, A10 = 0.0000E + 00
7th page
K = 0.0411,
A2 = 0.0000E + 00, A4 = 2.5206E-05, A6 = -3.6405E-07, A8 = 0.0000E + 00, A10 = 0.0000E + 00
16th page
K = 0.1251,
A2 = 0.0000E + 00, A4 = -2.2276E-04, A6 = -4.1935E-06, A8 = 1.3656E-07, A10 = 0.0000E + 00
18th page
K = -0.0925,
A2 = 0.0000E + 00, A4 = -3.2272E-04, A6 = 4.4236E-06, A8 = -2.4013E-07, A10 = 0.0000E + 00
23rd page
K = -0.1594,
A2 = 0.0000E + 00, A4 = 8.6051E-06, A6 = -5.3997E-06, A8 = 2.9886E-08, A10 = 0.0000E + 00

Various data zoom ratio 4.95
Wide angle Medium telephoto focal length 6.04738 13.53474 29.95923
F number 3.9288 4.2410 4.8167
Angle of view 36.8 ° 16.0 ° 7.2 °
Image height 3.84 3.84 3.84
Total lens length 58.0060 58.0110 58.0044
BF 0.79940 0.79940 0.79940

d7 0.60051 5.39340 8.67990
d14 9.46571 4.67549 1.38634
d17 5.22371 3.31714 1.36251
d20 4.17404 6.08801 8.03548
d24 2.56393 2.56393 2.56393

Zoom lens group data group Start surface Focal length
1 1 16.49250
2 8 -4.30301
3 15 17.77685
4 18 9.88546
5 21 44.68218

[Glass Material Refractive Index Table] ... Refractive index list by wavelength of medium used in this example
GLA 587.56 656.27 486.13 435.84 404.66
L13 1.525399 1.522577 1.531916 1.537043 1.541302
L12 2.094997 2.084179 2.121419 2.143451 2.162626
L3 1.634937 1.627308 1.654649 1.670838 1.685096 (LA)
L2 2.143520 2.125601 2.189954 2.232324 2.273184
L9, L14 1.516330 1.513855 1.521905 1.526213 1.529768
L6 1.788001 1.782998 1.799634 1.808881 1.816664
L5 1.804000 1.798815 1.816080 1.825698 1.833800
L7 1.772499 1.767798 1.783374 1.791971 1.799174
L4, L10 1.743198 1.738653 1.753716 1.762046 1.769040 (LB)
L8, L11 1.808095 1.798009 1.833513 1.855902 1.876580
L1 2.000690 1.989410 2.028720 2.052834 2.074600

Numerical Example 9
Unit mm

Surface data surface number rd nd νd
Object ∞ ∞
1 27.6145 1.0000 2.00069 25.46
2 13.0239 2.1000
3 ∞ 9.5000 2.14352 17.77
4 ∞ 0.2000
5 * 13.1656 0.1000 1.63494 23.22
6 * 9.5250 2.8000 1.74320 49.34
7 * -32.7902 variable
8 -32.8022 0.5000 1.80400 46.57
9 11.6063 0.6000
10 -31.9837 0.5000 1.77250 49.60
11 4.9153 1.0000 1.80810 22.76
12 18.1580 0.4000
13 -25.1963 0.5000 1.78800 47.37
14 36.1464 Variable
15 (STO) ∞ 0.8000
16 * 12.5130 1.5000 1.51633 64.14
17 -43.0156 Variable
18 * 15.0982 2.2000 1.74320 49.34
19 -6.5686 0.5000 1.80810 22.76
20 -12.4845 Variable
21 -60.8709 0.6000 2.09500 29.40
22 10.3767 7.3472
23 * 7.4713 2.3000 1.52540 56.25
24 40.1581 Variable
25 ∞ 0.8000 1.51633 64.14
26 ∞ 0.8001
Image plane ∞

Aspheric data 5th surface
K = 0.0291,
A2 = 0.0000E + 00, A4 = -4.4047E-05, A6 = 1.3091E-07, A8 = -1.1089E-08, A10 = 0.0000E + 00
6th page
K = 0.1497,
A2 = 0.0000E + 00, A4 = -1.2063E-04, A6 = -2.7557E-06, A8 = 0.0000E + 00, A10 = 0.0000E + 00
7th page
K = 0.0325,
A2 = 0.0000E + 00, A4 = 2.2798E-05, A6 = -3.3627E-07, A8 = 0.0000E + 00, A10 = 0.0000E + 00
16th page
K = 0.1348,
A2 = 0.0000E + 00, A4 = -1.8990E-04, A6 = -6.2525E-06, A8 = 3.0401E-07, A10 = 0.0000E + 00
18th page
K = -0.1035,
A2 = 0.0000E + 00, A4 = -3.0165E-04, A6 = 4.9551E-06, A8 = -2.7005E-07, A10 = 0.0000E + 00
23rd page
K = -0.1697,
A2 = 0.0000E + 00, A4 = 1.7420E-05, A6 = -6.7687E-06, A8 = 7.0760E-08, A10 = 0.0000E + 00

Various data zoom ratio 4.96
Wide angle Medium telephoto focal length 6.04558 13.53353 29.95661
F number 3.9288 4.2737 4.8656
Angle of view 36.8 ° 16.0 ° 7.2 °
Image height 3.84 3.84 3.84
Total lens length 58.0136 58.0246 58.0135
BF 0.80009 0.80009 0.80009

d7 0.60348 5.37422 8.66850
d14 9.44247 4.67824 1.37750
d17 5.11648 3.19734 1.25573
d20 4.13795 6.06764 7.99887
d24 2.66593 2.66593 2.66593

Zoom lens group data group Start surface Focal length
1 1 16.14071
2 8 -4.35163
3 15 18.94768
4 18 10.00503
5 21 -70.71964

[Glass Material Refractive Index Table] ... Refractive index list by wavelength of medium used in this example
GLA 587.56 656.27 486.13 435.84 404.66
L13 1.525399 1.522577 1.531916 1.537043 1.541302
L12 2.094997 2.084179 2.121419 2.143451 2.162626
L3 1.634937 1.627308 1.654649 1.670838 1.685096 (LA)
L2 2.143520 2.125601 2.189954 2.232324 2.273184
L9, L14 1.516330 1.513855 1.521905 1.526213 1.529768
L8 1.788001 1.782998 1.799634 1.808881 1.816664
L5 1.804000 1.798815 1.816080 1.825698 1.833800
L6 1.772499 1.767798 1.783374 1.791971 1.799174
L4, L10 1.743198 1.738653 1.753716 1.762046 1.769040 (LB)
L7, L11 1.808095 1.798009 1.833513 1.855902 1.876580
L1 2.000690 1.989410 2.028720 2.052834 2.074600

Next, parameter values and conditional expression values in each embodiment will be listed. *** indicates that the condition is not satisfied.
Example 1 Example 2 Example 3 Example 4 Example 5
fw (wide-angle end) 6.051 6.061 6.203 5.005 6.072
ft (telephoto end) 29.960 29.957 30.999 24.993 29.955
γ 4.951 4.943 4.997 4.994 4.933
y ₁₀ 3.84 3.84 3.84 3.84 3.84
E 10.466 7.906 9.628 10.921 6.278
f12 13.101 10.432 12.669 8.840 10.123
E / f12 0.799 0.758 0.760 1.235 0.620
nd (LB) 1.88300 1.74320 2.04300 1.80610 1.80610
νd (LA) 23.22 23.22 23.22 19.30 23.22
R _C −17.614 −13.857 14.805 −36.799 −53.668
Δ _zA (h) 0.00988 −0.00742 −0.00952 0.12547 0
_{Δ zB (h) -0.00910 -0.00692 0.00500} -0.00871 -0.07001
_{{Δ zA (h) + Δ} zB (h)} / 2 0.00039 -0.00717 -0.00226 0.05838 -0.03501
Δ _zC (h) −0.01246 −0.01047 0.02716 −0.00397 −0.08914
h 4.232 4.221 4.152 5.144 4.208
a 1.693 1.688 1.661 2.058 1.683
θgF (LA) 0.6030 0.6477 0.5840 0.5840 0.5840
β (LA) 0.6408 0.6855 0.6218 0.6155 0.6155
θhg (LA) 0.5379 0.6003 0.5080 0.5080 0.5080
βhg (LA) 0.5901 0.6525 0.5602 0.5514 0.5514
νd (LB) 40.76 49.34 39.00 40.92 40.92
θgF (LB) 0.5669 0.5528 0.5657 0.5703 0.5703
β (LB) 0.6333 0.6332 0.6293 0.6370 0.6370
θhg (LB) 0.4811 0.4638 0.4772 0.4881 0.4881
βhg (LB) 0.5728 0.5748 0.5650 0.5802 0.5802
θgF (LA) −θgF (LB) 0.0361 0.0949 0.0183 0.0137 0.0137
θhg (LA) −θhg (LB) 0.0568 0.1365 0.0308 0.0199 0.0199
νd (LA) −νd (LB) −17.54 −26.12 −15.78 −21.62 −17.70
β _2w −0.691 −0.685 −0.692 −0.640 −0.680
β _34w −0.445 −0.655 −0.529 −0.694 −0.636
β _5w 1.206 1.055 1.120 1.062 0.981
N _5n -N _5p 0.65603 0.52558 0.65603 0.65603 0.48697
ν _5p −ν _5n 52.46 13.43 52.46 52.46 35.87
R _G5F −15.820 −362.564 −21.477 81.082 16.080
R _G5R −7.546 −10.605 −6.390 −8.302 −10.593
(R _G5F + R _G5R ) / (R _G5F -R _G5R ) 0.3541 0.9434 0.5414 1.229 4.854
t1 0.1 0.1 0.1 0.1 0.1
y ₀₇ 2.688 2.688 2.688 2.688 2.688
_tanω 07w 0.4814 0.4803 0.4632 0.5851 0.4960
y ₀₇ / (fw ・_{tanω 07w} ) 0.9228 0.9234 0.9355 0.9181 0.8925
nd (LA) 1.63494 1.63494 1.63494 1.67000 1.63494

Example 6 Example 7 Example 8 Example 9
fw (wide-angle end) 6.053 6.049 6.047 6.046
ft (telephoto end) 29.958 29.955 29.959 29.957
γ 4.949 4.952 4.954 4.955
y ₁₀ 3.84 3.84 3.84 3.84
E 6.835 8.210 6.593 6.793
f12 10.515 12.792 12.749 12.502
E / f12 0.650 0.642 0.517 0.543
nd (LB) 1.80610 1.74320 1.74320 1.74320
νd (LA) 23.22 23.22 23.22 23.22
R _C 23.384 −40.158 9.595 9.525
Δ _zA (h) 0.00683 0 −0.01681 −0.01403
_{Δ zB (h) -0.00300 -0.03462 0.00598} 0.00537
_{{Δ zA (h) + Δ} zB (h)} / 2 0.00192 -0.01731 -0.00542 -0.00433
Δ _zC (h) −0.00734 −0.08108 −0.02479 −0.04604
h 4.230 4.234 4.238 4.238
a 1.692 1.694 1.695 1.695
θgF (LA) 0.6477 0.5945 0.5921 0.5921
β (LA) 0.6855 0.6323 0.6299 0.6299
θhg (LA) 0.6003 0.5240 0.5215 0.5215
βhg (LA) 0.6525 0.5762 0.5737 0.5737
νd (LB) 40.92 49.34 49.34 49.34
θgF (LB) 0.5703 0.5528 0.5528 0.5528
β (LB) 0.6370 0.6332 0.6332 0.6332
θhg (LB) 0.4881 0.4638 0.4638 0.4638
βhg (LB) 0.5802 0.5748 0.5748 0.5748
θgF (LA) −θgF (LB) 0.0774 0.0417 0.0393 0.0393
θhg (LA) −θhg (LB) 0.1122 0.0602 0.0577 0.0577
νd (LA) −νd (LB) −17.70 −26.12 −26.12 −26.12
β _2w −0.544 −0.325 −0.323 −0.330
β _34w −0.715 −0.608 −0.576 −0.581
β _5w 1.211 1.854 1.968 1.957
N _5n -N _5p 0.62720 0.65603 0.56960 0.56960
ν _5p −ν _5n 46.37 52.46 26.85 26.85
R _G5F -7.819 *** *** *** ***
R _G5R −7.105 *** *** *** ***
(R _G5F + R _G5R ) / (R _G5F -R _G5R ) 0.04784 _* * _* * _* * _{* *} *
t1 0.1 0.1 0.1 0.1
y ₀₇ 2.688 2.688 2.688 2.688
_tanω 07w 0.4702 0.4882 0.4861 0.4851
y ₀₇ / (fw ・_{tanω 07w} ) 0.9444 0.9102 0.9145 0.9165
nd (LA) 1.63494 1.63494 1.63494 1.63494

(Example 10)
The imaging optical system of the present invention as described above is a photographing apparatus for photographing an image of an object with an electronic image sensor such as a CCD or CMOS, in particular, a digital camera, a video camera, a personal computer or an example of an information processing apparatus, a telephone. It can be used for portable terminals, especially mobile phones that are convenient to carry. The embodiment is illustrated below.

  FIGS. 19 to 21 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 a digital camera. 19 is a front perspective view showing the appearance of the digital camera 40, FIG. 20 is a rear perspective view thereof, and FIG. 21 is a cross-sectional view showing an optical configuration of the digital camera 40.

  In this example, the digital camera 40 includes a photographing optical system 41 having a photographing optical path 42, a finder optical system 43 having a finder optical path 44, a shutter 45, a flash 46, a liquid crystal display monitor 47, and the like. Then, when the photographer presses the shutter 45 disposed on the upper part of the camera 40, photographing is performed through the photographing optical system 41, for example, the zoom lens 48 of the first embodiment in conjunction therewith.

  The object image formed by the photographing optical system 41 is formed on the image pickup surface of the CCD 49. The object image received by the CCD 49 is displayed as an electronic image on the liquid crystal display monitor 47 provided on the back of the camera via the image processing means 51. Further, the image processing means 51 is provided with a memory or the like, and can record a captured electronic image. This memory may be provided separately from the image processing means 51, or may be configured to perform recording and writing electronically using a flexible disk, memory card, MO, or the like.

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

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

  Next, a personal computer which is an example of an information processing apparatus in which the imaging optical system of the present invention is incorporated as an objective optical system is shown in FIGS. 22 is a front perspective view of the personal computer 300 with the cover open, FIG. 23 is a sectional view of the photographing optical system 303 of the personal computer 300, and FIG. 24 is a side view of FIG. As shown in FIGS. 22 to 24, the personal computer 300 includes a keyboard 301, information processing means and recording means, a monitor 302, and a photographing optical system 303.

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

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

A cover glass 102 for protecting the objective optical system 100 is disposed at the tip of the mirror frame.
The object image received by the electronic image sensor chip 162 is input to the processing means of the personal computer 300 via the terminal 166. Finally, the object image is displayed on the monitor 302 as an electronic image. FIG. 22 shows an image 305 taken by the operator as an example. The image 305 can also be displayed on a communication partner's personal computer from a remote location via the processing means. The Internet and telephone are used for image transmission to remote places.

  Next, FIG. 25 shows a telephone which is an example of an information processing apparatus in which the imaging optical system of the present invention is incorporated as a photographing optical system, particularly a portable telephone which is convenient to carry. 25A is a front view of the mobile phone 400, FIG. 25B is a side view, and FIG. 25C is a cross-sectional view of the photographing optical system 405. As shown in FIGS. 25A to 25C, the mobile phone 400 includes a microphone unit 401, a speaker unit 402, an input dial 403, a monitor 404, a photographing optical system 405, an antenna 406, and processing. Means.

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

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

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

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

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

Explanation of symbols

G1 1st lens group G2 2nd lens group G3 3rd lens group G4 4th lens group G5 5th lens group L1-L13 Each lens LPF Low pass filter CG Cover glass I Imaging surface E Observer's eye 40 Digital camera 41 Shooting optics System 42 Optical path for photographing 43 Viewfinder optical system 44 Optical path for viewfinder 45 Shutter 46 Flash 47 LCD monitor 48 Zoom lens 49 CCD
DESCRIPTION OF SYMBOLS 50 Image pick-up surface 51 Processing means 53 Finder objective optical system 55 Porro prism 57 Field frame 59 Eyepiece optical system 66 Focusing lens 67 Imaging surface 100 Objective optical system 102 Cover glass 162 Electronic image pick-up element chip | tip 166 Terminal 300 Personal computer 301 Keyboard 302 Monitor 303 Imaging Optical System 304 Imaging Optical Path 305 Image 400 Mobile Phone 401 Microphone Unit 402 Speaker Unit 403 Input Dial 404 Monitor 405 Imaging Optical System 406 Antenna 407 Imaging Optical Path

Claims (11)

An imaging optical system including a first lens group G1 disposed on the most object side and having a positive refractive power,
The first lens group G1 includes a reflective optical element and a lens component C1p disposed on the image side of the reflective optical element and having a positive refractive power,
In the lens component C1p, a negative lens LA and a positive lens LB are cemented, and the cemented surface is an aspheric surface.
An imaging optical system characterized by satisfying the following conditional expression (1):
0.4 <E / f12 <2.0 (1)
here,
E is the air equivalent distance along the optical axis between the top Ct1 and the top Ct2,
The surface top Ct1 is the surface top of the surface having the strongest negative refractive power among the refractive surfaces on the object side of the reflective surface of the reflective optical element,
Surface top Ct2 is the surface top of the cemented surface of the lens component C1p,
f12 is the combined focal length of all the lenses constituting the first lens group G1 that are closer to the image side than the reflective optical element. However, when the reflective optical element has an exit surface and the exit surface has a refractive power, it is a combined focal length when the exit surface is included.   2. The imaging optical system according to claim 1, wherein the material of the negative lens LA is an energy curable resin, and the lens component C1p is formed by a direct molding method on the positive lens LB.   The imaging optical system according to claim 1, wherein the reflective optical element is a prism, and a refractive index of the medium is 1.8 or more. The imaging optical system according to claim 1, wherein the following conditional expression (2) is satisfied.
1.60 <nd (LB) <2.4 (2)
Here, nd (LB) is a refractive index with respect to the d line of the positive lens LB. The imaging optical system according to claim 1, wherein the conditional expression (3) is satisfied.
3 <νd (LA) <35 (3)
Here, νd (LA) is the Abbe number of the negative lens LA with respect to the d-line. The optical axis z, a direction perpendicular to the optical axis is a coordinate axis is h, the radius of curvature on the optical axis of the spherical R component, k a conic _{constant, A 4, A 6, A} 8, A 10 ··· As the aspheric coefficient, the shape of the aspheric surface is expressed by the following formula (4),
^{z = h 2 / R [1+} {1- (1 + K) h 2 / R 2} 1/2]
+ A ₄ h ⁴ + A ₆ h ⁶ + A ₈ h ⁸ + A ₁₀ h ¹⁰ +... (4)
When the deviation amount is expressed by the following equation (5),
Δz = z−h ² / R [1+ {1−h ² / R ² } ^1/2 ] (5)
The imaging optical system according to claim 1, wherein the following conditional expression (6a) or (6b) is satisfied.
When R _C ≦ 0
Δz _C (h) ≦ (Δz _A (h) + Δz _B (h)) / 2 <where h = 2.5a> (6a)
When R _C ≧ 0
Δz _C (h) ≧ (Δz _A (h) + Δz _B (h)) / 2 <where h = 2.5a> (6b)
here,
z _A is the shape of the air contact surface of the negative lens LA, and the shape according to equation (4),
z _B is the shape of the air contact surface of the positive lens LB, and the shape according to equation (4),
z _C is the shape of the joint surface, the shape according to formula (4),
Δz _A is a deviation amount on the air contact surface of the negative lens LA, and is an amount according to the equation (5),
Δz _B is a deviation amount on the air contact surface of the positive lens LB, and is an amount according to the equation (5),
Δz _C is a deviation amount in the joint surface, and is an amount according to the equation (5),
R _C is the paraxial radius of curvature of the joint surface,
a is an amount according to the following equation (7),
a = (y ₁₀ ) ² · log ₁₀ γ / fw (7)
In the formula (7),
y ₁₀ is the maximum image height,
fw is the focal length γ of the entire system at the wide-angle end of the imaging optical system is the zoom ratio (total focal length at the telephoto end / total focal length at the wide-angle end) of the imaging optical system,
Since the top of each surface is the origin, z (0) = 0 is always set. Furthermore, it has a second lens group G2 having negative refractive power and movable at the time of zooming,
The imaging optical system according to claim 1, wherein the following condition is satisfied.
−1.2 <β _2w <−0.3 (16)
Here, β2w is the imaging magnification at the wide-angle end of the second lens group G2, and the absolute value of the imaging magnification of the entire imaging optical system at the wide-angle end is 0.01 or less. This is the imaging magnification when focused on a point. Following the second lens group G2, a third lens group G3 having a positive refractive power and a fourth lens group G4 having a positive refractive power,
The imaging optical system according to claim 7, wherein the following conditional expression (17) is satisfied.
−1.8 <β _34w <−0.3 (17)
Here, β _34w is the imaging magnification of the composite system at the wide angle end of the third lens group G3 and the fourth lens group G4, and is the absolute value of the imaging magnification of the entire imaging optical system at the wide angle end Is the imaging magnification when focusing on any object point with a value of 0.01 or less. Having another lens group G31 having a positive refractive power between the second lens group G2 and the third lens group G3,
The imaging optical system according to claim 8, wherein the following conditional expression (17-1) is satisfied.
−1.8 <β _34w ′ <−0.3 (17-1)
Here, β _34w ′ is the imaging magnification of the composite system at the wide-angle end of the other lens group G31, the third lens group G3, and the fourth lens group G4, and is the entire imaging optical system at the wide-angle end. This is the imaging magnification when focusing on any object point where the absolute value of the imaging magnification of the system is 0.01 or less. It has the fifth lens group G5 on the most image side,
The fifth lens group G5 consists only of lens components whose distance from the image plane is substantially constant at the time of zooming,
At the time of zooming, the relative distance between the fifth lens group G5 and the lens group adjacent to the fifth lens group G5 changes.
The imaging optical system according to claim 1, wherein the following conditional expression (18) is satisfied.
0.95 <β _5W <2.5 (18)
Here, β _5W is the imaging magnification of the fifth lens group G5, and is an object point at which the absolute value of the imaging magnification of the entire imaging optical system at the wide angle end is 0.01 or less. This is the imaging magnification when focused. The imaging optical system according to any one of claims 1 to 10, an electronic imaging device, and image data obtained by imaging an image formed through the imaging optical system with the electronic imaging device. Image processing means for processing and outputting as image data in which the shape of the image is changed,
The imaging optical system is a zoom lens;
An electronic imaging apparatus characterized in that the zoom lens satisfies the following conditional expression (26) when focusing on an object point at infinity.
0.7 <y ₀₇ / (fw · tan ω _07w ) <0.96 (26)
here,
y ₀₇ is expressed as y ₀₇ = 0.7y ₁₀ when the effective image pickup plane of the electronic imaging device the distance to the farthest point from the center in (imageable plane) (maximum image height) was y _10,
ω _07w is an angle with respect to the optical axis in the object point direction corresponding to the image point connecting from the center on the imaging surface to the position y ₀₇ at the wide-angle end.

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