JP2008102398A - Variable power optical system and imaging apparatus using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high variable power optical system where the effective diameter of a front lens is comparatively small, and to provide an imaging apparatus that uses the same. <P>SOLUTION: The variable power optical system has a first positive lens group G1, a second negative lens group G2 having the largest variable power effect, when varying power, a third positive lens group G3 having a shutter and an aperture stop S and fixed, when varying power, a fourth positive lens group G4 and a fifth negative lens group G5 in order from the object side, and satisfies the conditional Expression (1): -10<f<SB>t</SB>/f<SB>2</SB><-7 concerning the focal length of the second lens group G2, and the conditional Expression (2): -1.8≤f<SB>t</SB>/f<SB>tg12</SB>≤-0.92 concerning the synthetic focal length of the first lens group G1 and the second lens group G2 at a telephoto end. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a variable magnification optical system and an imaging apparatus using the same, and more particularly to a high variable magnification optical system having a relatively small front lens effective diameter and an imaging apparatus using the same.

  In recent years, imaging apparatuses using an electronic imaging element such as a digital still camera have been widely used. With the development and popularization of digital still cameras, high-magnification and compact optical systems are required.

  In the high variable magnification optical system, in order from the object side, there are a positive first lens group, a negative second lens group, a positive third lens group, a positive fourth lens group, and a negative fifth lens group. Many optical systems having an aperture stop near the third lens group have been proposed. In the case of this configuration, most of the zooming is performed by the second lens group moving on the optical axis.

  In the one described in Patent Document 1, it is composed of a positive first lens group, a negative second lens group, a positive third lens group, a positive fourth lens group, and a negative fifth lens group. The second lens unit and the third lens unit that move during zooming do not move during zooming.

  In addition, the device described in Patent Document 2 includes a positive first lens group, a negative second lens group, a positive third lens group, a positive fourth lens group, and a negative fifth lens group. The one lens group, the third lens group, and the fifth lens group are fixed at the time of zooming, and the aperture stop is configured integrally with the third lens group.

Patent Document 3 discloses a positive first lens group, a negative second lens group, a positive third lens group, a positive fourth lens group, a negative fifth lens group, and a positive sixth lens group. The first lens group, the fourth lens group, and the sixth lens group are fixed during zooming. The aperture stop is integrated with the third lens group and moves during zooming.
Japanese Patent Laid-Open No. 5-113538 JP-A-8-327904 JP 2001-750008 A JP 11-64714 A

  In any of the above patent documents, the magnification change of the second lens group accounts for most of the entire magnification change to achieve high zooming, and the aperture stop is disposed on the imaging surface side of the second lens group. ing.

  When the second lens group bears most of the magnification change, in order to increase the zoom ratio, it is necessary to increase the amount of movement of the second lens group or increase the refractive power of the second lens group.

  However, as the amount of movement of the second lens group increases, the lens frame mechanism becomes complicated or large, and when the refractive power is increased, aberration fluctuations due to zooming increase, and it becomes difficult to ensure optical performance. In addition, since the entrance pupil position is in the back of the optical system and the effective diameter of the first lens group is increased, it is difficult to achieve both high zooming and small size, and the weight increases as the effective diameter increases. It is necessary to increase the strength of the drive mechanism itself, leading to an increase in size and complexity.

  However, increasing the magnification burden on the imaging surface side of the aperture stop increases the variation of the exit pupil position, so the light receiving efficiency of the electronic image sensor deteriorates. Therefore, the magnification burden behind the aperture stop is increased. That is not preferable.

  The present invention has been made in view of such a situation in the prior art, and an object thereof is to provide a high-magnification optical system having a relatively small front lens effective diameter and an imaging apparatus using the same.

  The variable magnification optical system of the present invention that achieves the above object, in order from the object side, includes a first lens group having a positive refractive power and a second lens having a negative refractive power and having the largest variable magnification effect at the time of zooming. A third lens group having a positive positive refractive power at the time of zooming, a fourth lens group having a positive refractive power, and a fifth lens group having a negative refractive power; And satisfying the following conditional expression.

−10 < _ft / f ₂ <−7 (1)
_{-1.8 ≦ f t / f tg12 ≦} -0.92 ··· (2)
Where f _t is the focal length of the entire system at the telephoto end,
f ₂ is the focal length of the second lens group
f _tg12 is the combined focal length of the first lens group and the second lens group at the telephoto end,
It is.

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

  As in the above variable magnification optical system, in order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power and having the largest variable power effect at the time of variable power, A third lens group having a positive refracting power at the time of zooming having a shutter and an aperture stop, a fourth lens group having a positive refracting power, and a fifth lens group having a negative refracting power. Thus, it is possible to obtain a high variable magnification optical system having a relatively small front lens effective diameter.

  Conditional expression (1) is a conditional expression related to the focal length of the second lens group having the largest zooming effect. If the upper limit of −7 is exceeded, the amount of movement of the second lens group becomes large. Becomes larger or complicated and falls below the lower limit of −10, the zooming burden of the second lens group increases, and the tilt of the image plane on the telephoto side due to the eccentricity of the second lens group increases.

  Conditional expression (2) is a conditional expression related to the combined focal length of the first lens group and the second lens group at the telephoto end, and if the upper limit of −0.92 is exceeded, the variable magnification burden of the second lens group is large. Since it becomes difficult to achieve both the spherical aberration on the telephoto side and the off-axis aberration on the wide angle side, and the front lens diameter is large and heavy, the burden on the drive mechanism for zooming increases. On the other hand, if the lower limit of −1.8 is not reached, the total length on the telephoto side becomes long, and it becomes difficult to reduce the size.

  In this case, it is desirable to have a reflecting member that bends the optical axis at a substantially right angle on the imaging surface side of the third lens group having positive refractive power.

  By configuring in this way, the optical axis is bent on the imaging surface side of the third lens group, so that the lens barrel feeding mechanism can be simplified, and the thickness when retracted can be suppressed. .

  Further, it is desirable that the reflecting member is a surface reflecting mirror.

  That is, by using a surface reflecting mirror as the reflecting member, it is possible to reduce the weight and simplify the holding mechanism.

  The present invention includes an imaging apparatus including the above-described variable-power optical system and an image sensor that is disposed on the image side of the variable-power optical system and converts an optical image into an electrical signal.

  In this case, it is desirable to arrange a low-pass filter between the zoom optical system and the image sensor.

  According to the present invention described above, it is possible to obtain a high variable magnification optical system having a relatively small front lens effective diameter and an imaging device using the same. The variable power optical system of the present invention is particularly suitable for a bending variable power optical system that is thin and can be accommodated in a small size.

  Examples 1 to 6 of the variable magnification optical system of the present invention will be described below. Lens cross-sectional views at the wide-angle end (a), the intermediate state (b), and the telephoto end (c) at the time of focusing on an object point at infinity, where the optical path of the variable magnification optical system of Examples 1 to 6 is developed, are shown in FIGS. As shown in FIG. In each figure, the first lens group is G1, the second lens group is G2, the aperture stop is S, the third lens group is G3, the fourth lens group is G4, the fifth lens group is G5, and the sixth lens group is G6. An optical low-pass filter is indicated by F, a cover glass of a CCD which is an electronic image pickup element is indicated by C, and an image surface of the CCD is indicated by I. As for the near-infrared sharp cut coat, for example, the optical low-pass filter F may be directly coated, or an infrared cut absorption filter may be provided separately, or the transparent flat plate incident surface may be provided. A near infrared sharp cut coat may be used.

  As shown in FIG. 1, the bending variable magnification optical system according to the first embodiment includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, an aperture stop S, and a positive refractive power. The third lens group G3, the fourth lens group G4 having a positive refractive power, the fifth lens group G5 having a negative refractive power, and the sixth lens group G6 having a positive refractive power, and changing from the wide-angle end to the telephoto end. When doubling, the first lens group G1 moves toward the object side, and the second lens group G2 moves monotonously toward the image side. The aperture stop S and the third lens group G3 are fixed, the fourth lens group G4 moves to the object side, and the fifth lens group G5 has a convex locus on the object side while increasing the distance from the fourth lens group G4. It is drawn and moved, and at the telephoto end, it is located slightly closer to the object side than the wide-angle end. The sixth lens group G6 moves along a locus convex toward the object side while increasing the distance from the fifth lens group G5, and is located closer to the image side than the wide-angle end position at the telephoto end.

  In order from the object side, the first lens group G1 is composed of a negative meniscus lens having a convex surface facing the object side, a cemented lens of a biconvex positive lens, and a biconvex positive lens, and the second lens group G2 is a biconcave negative lens. And a cemented lens of a negative meniscus lens having a convex surface facing the image side and a positive meniscus lens having a convex surface facing the image side. The third lens group G3 includes one biconvex positive lens, and a fourth lens. The group G4 includes a biconvex positive lens, and a cemented lens of a biconcave negative lens and a biconvex positive lens. The fifth lens group G5 includes a cemented lens of a biconvex positive lens and a biconcave negative lens. The lens group G6 includes one biconvex positive lens.

  The aspherical surfaces are the double-convex positive lenses of the single lens of the first lens group G1, the image-side surfaces of the double-concave negative lens of the second lens group G2, and the double-convex positive lenses of the single lens of the fourth lens group G4. The double-sided lens is used for six surfaces on the image side of the biconvex positive lens of the sixth lens group G6.

The fourteenth surface r ₁₄ in the numerical data given later is a virtual surface provided on designed to prevent interference between the reflecting surface and the fourth lens unit G4, not any member exists. A reflective surface that bends the optical axis at a substantially right angle (for example, 90 °) is provided between the third lens group G3 and the virtual surface r ₁₄ at an angle of 45 ° with respect to the optical axis. The position is fixed integrally with the third lens group G3 during photographing.

  As shown in FIG. 2, the bending variable power optical system of Example 2 includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, an aperture stop S, and a positive refractive power. The third lens group G3, the fourth lens group G4 having a positive refractive power, the fifth lens group G5 having a negative refractive power, and the sixth lens group G6 having a positive refractive power, and changing from the wide-angle end to the telephoto end. When doubling, the first lens group G1 moves toward the object side, and the second lens group G2 moves monotonously toward the image side. The aperture stop S and the third lens group G3 are fixed, the fourth lens group G4 moves to the object side, and the fifth lens group G5 has a convex locus on the object side while increasing the distance from the fourth lens group G4. It is drawn and moved, and at the telephoto end, it is located slightly closer to the object side than the wide-angle end. The sixth lens group G6 moves along a locus convex toward the object side while increasing the distance from the fifth lens group G5, and is located closer to the image side than the wide-angle end position at the telephoto end.

  In order from the object side, the first lens group G1 is composed of a negative meniscus lens having a convex surface facing the object side, a cemented lens of a biconvex positive lens, and a biconvex positive lens, and the second lens group G2 is a biconcave negative lens. The third lens group G3 is composed of a single positive meniscus lens having a convex surface facing the image side, and the fourth lens group G4 is a biconvex lens. The fifth lens group G5 includes a cemented lens of a biconvex positive lens and a biconcave negative lens, and the sixth lens group G6 includes both a cemented lens of a positive lens and a biconcave negative lens, and a biconvex positive lens. Consists of a single convex positive lens.

  The aspherical surfaces are the double-sided positive-convex lens of the single lens of the first lens group G1, the image-side surface of the double-concave negative lens of the single lens of the second lens group G2, and the most object of the cemented lens of the fourth lens group G4. This is used for the seven surfaces of the side surface, the image side surface of the biconvex positive lens of the single lens, and both surfaces of the biconvex positive lens of the sixth lens group G6.

The fourteenth surface r ₁₄ in the numerical data given later is a virtual surface provided on designed to prevent interference between the reflecting surface and the fourth lens unit G4, not any member exists. A reflective surface that bends the optical axis at a substantially right angle (for example, 90 °) is provided between the third lens group G3 and the virtual surface r ₁₄ at an angle of 45 ° with respect to the optical axis. The position is fixed integrally with the third lens group G3 during photographing.

  As shown in FIG. 3, the bending variable magnification optical system of Example 3 includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, an aperture stop S, and a positive refractive power. The third lens group G3, the fourth lens group G4 having a positive refractive power, the fifth lens group G5 having a negative refractive power, and the sixth lens group G6 having a positive refractive power, and changing from the wide-angle end to the telephoto end. When doubling, the first lens group G1 moves along a locus convex toward the image side, and is located closer to the object side at the telephoto end than at the wide-angle end. The second lens group G2 moves monotonously to the image side. The aperture stop S and the third lens group G3 are fixed, the fourth lens group G4 moves along a locus convex toward the object side, and is located closer to the object side at the telephoto end than at the wide-angle end. The fifth lens group G5 moves along a locus convex toward the object side while increasing the distance from the fourth lens group G4, and is located slightly closer to the image side than the wide-angle end position at the telephoto end. The sixth lens group G6 moves along a locus convex toward the object side while increasing the distance from the fifth lens group G5, and is located closer to the image side than the wide-angle end position at the telephoto end.

  In order from the object side, the first lens group G1 is composed of a negative meniscus lens having a convex surface facing the object side, a cemented lens of a biconvex positive lens, and a positive meniscus lens having a convex surface facing the object side. G2 includes a biconcave negative lens, and a cemented lens of a biconcave negative lens and a positive meniscus lens having a convex surface facing the object side. The third lens group G3 includes one biconvex positive lens, and a fourth lens. The group G4 includes a biconvex positive lens, and a cemented lens of a biconcave negative lens and a biconvex positive lens. The fifth lens group G5 includes a cemented lens of a biconvex positive lens and a biconcave negative lens. The lens group G6 includes one biconvex positive lens.

  The aspheric surfaces are both surfaces of the positive meniscus lens of the first lens group G1, the image side surface of the biconcave negative lens of the single lens of the second lens group G2, and both surfaces of the biconvex positive lens of the single lens of the fourth lens group G4. And 7 surfaces on both sides of the biconvex positive lens of the sixth lens group G6.

The fourteenth surface r ₁₄ in the numerical data given later is a virtual surface provided on designed to prevent interference between the reflecting surface and the fourth lens unit G4, not any member exists. A reflective surface that bends the optical axis at a substantially right angle (for example, 90 °) is provided between the third lens group G3 and the virtual surface r ₁₄ at an angle of 45 ° with respect to the optical axis. The position is fixed integrally with the third lens group G3 during photographing.

  As shown in FIG. 4, the bending variable magnification optical system 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, a positive refractive power. The third lens group G3, the fourth lens group G4 having a positive refractive power, the fifth lens group G5 having a negative refractive power, and the sixth lens group G6 having a positive refractive power, and changing from the wide-angle end to the telephoto end. When doubling, the first lens group G1 moves along a locus convex toward the image side, and is located closer to the object side at the telephoto end than at the wide-angle end. The second lens group G2 moves monotonously to the image side. The aperture stop S and the third lens group G3 are fixed, the fourth lens group G4 moves to the object side, and the fifth lens group G5 has a convex locus on the object side while increasing the distance from the fourth lens group G4. It moves by drawing, and at the telephoto end, it is located closer to the object side than the wide-angle end. The sixth lens group G6 moves along a locus convex toward the object side while increasing the distance from the fifth lens group G5, and is located closer to the image side than the wide-angle end position at the telephoto end.

  In order from the object side, the first lens group G1 is composed of a negative meniscus lens having a convex surface facing the object side, a cemented lens of a biconvex positive lens, and a biconvex positive lens, and the second lens group G2 is a biconcave negative lens. Lens, a biconcave negative lens, and a cemented lens of a positive meniscus lens having a convex surface facing the object side. The third lens group G3 is composed of one biconvex positive lens, and the fourth lens group G4 is biconvex. The fifth lens group G5 includes a cemented lens of a biconvex positive lens and a biconcave negative lens, and the sixth lens group G6 includes a cemented lens of a positive lens, a biconcave negative lens, and a biconvex positive lens. Consists of a single convex positive lens.

  The aspherical surfaces are the surfaces of the biconvex positive lens of the first lens group G1, the image side surface of the biconcave negative lens of the single lens of the second lens group G2, and the biconvex positive lens of the single lens of the fourth lens group G4. It is used on both sides of the double-sided and double-sided positive lens of the sixth lens group G6.

The fourteenth surface r ₁₄ in the numerical data given later is a virtual surface provided on designed to prevent interference between the reflecting surface and the fourth lens unit G4, not any member exists. A reflective surface that bends the optical axis at a substantially right angle (for example, 90 °) is provided between the third lens group G3 and the virtual surface r ₁₄ at an angle of 45 ° with respect to the optical axis. The position is fixed integrally with the third lens group G3 during photographing.

  As shown in FIG. 5, the bending variable magnification optical system of Example 5 includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, an aperture stop S, and a positive refractive power. The third lens group G3, the fourth lens group G4 having a positive refractive power, the fifth lens group G5 having a negative refractive power, and the sixth lens group G6 having a positive refractive power, and changing from the wide-angle end to the telephoto end. When doubling, the first lens group G1 moves along a locus convex toward the image side, and is located closer to the object side at the telephoto end than at the wide-angle end. The second lens group G2 moves monotonously to the image side. The aperture stop S and the third lens group G3 are fixed, the fourth lens group G4 moves to the object side, and the fifth lens group G5 has a convex locus on the object side while increasing the distance from the fourth lens group G4. It is drawn and moved, and at the telephoto end, it is positioned closer to the image side than at the wide-angle end. The sixth lens group G6 moves along a locus convex toward the object side while increasing the distance from the fifth lens group G5, and is located closer to the image side than the wide-angle end position at the telephoto end.

  In order from the object side, the first lens group G1 is composed of a negative meniscus lens having a convex surface facing the object side, a cemented lens of a biconvex positive lens, and a biconvex positive lens, and the second lens group G2 is a biconcave negative lens. The third lens group G3 is composed of a positive meniscus lens having a convex surface facing the image side, and a negative meniscus lens having a convex surface facing the image side and a positive meniscus lens having a convex surface facing the image side. The fourth lens group G4 includes a biconvex positive lens, a biconcave negative lens, and a cemented lens of a positive meniscus lens having a convex surface facing the object side. The fifth lens group G5 includes a biconvex positive lens. The sixth lens group G6 is composed of a single biconvex positive lens.

  The aspherical surfaces are both surfaces of the biconvex positive lens of the first lens group G1, the image side surface of the biconcave negative lens of the second lens group G2, both surfaces of the biconvex positive lens of the fourth lens group G4, and the sixth lens group. It is used for six surfaces on the image side of the G6 biconvex positive lens.

The fourteenth surface r ₁₄ in the numerical data given later is a virtual surface provided on designed to prevent interference between the reflecting surface and the fourth lens unit G4, not any member exists. A reflective surface that bends the optical axis at a substantially right angle (for example, 90 °) is provided between the third lens group G3 and the virtual surface r ₁₄ at an angle of 45 ° with respect to the optical axis. The position is fixed integrally with the third lens group G3 during photographing.

  As shown in FIG. 6, the bending variable magnification optical system of Example 6 includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, an aperture stop S, and a positive refractive power. The third lens group G3, the fourth lens group G4 having a positive refractive power, the fifth lens group G5 having a negative refractive power, and the sixth lens group G6 having a positive refractive power, and changing from the wide-angle end to the telephoto end. When doubling, the first lens group G1 moves along a locus convex toward the image side, and is located closer to the object side at the telephoto end than at the wide-angle end. The second lens group G2 moves monotonously to the image side. The aperture stop S and the third lens group G3 are fixed, the fourth lens group G4 moves to the object side, and the fifth lens group G5 has a convex locus on the object side while increasing the distance from the fourth lens group G4. It is drawn and moved, and at the telephoto end, it is positioned closer to the image side than at the wide-angle end. The sixth lens group G6 moves along a locus convex toward the object side while increasing the distance from the fifth lens group G5, and is located closer to the image side than the wide-angle end position at the telephoto end.

  In order from the object side, the first lens group G1 is composed of a negative meniscus lens having a convex surface facing the object side, a cemented lens of a biconvex positive lens, and a biconvex positive lens, and the second lens group G2 is a biconcave negative lens. The third lens group G3 is composed of one biconvex positive lens, and the fourth lens group G4 is composed of a biconvex positive lens and a biconcave lens. The fifth lens group G5 is composed of a cemented lens of a biconvex positive lens and a biconcave negative lens, and the sixth lens group G6 is composed of one biconvex positive lens. Become.

  The aspheric surfaces are the surfaces of the biconvex positive lens of the single lens of the first lens group G1, the image side surface of the biconcave negative lens of the single lens of the second lens group G2, and the biconvex positive lens of the fourth lens group G4. It is used on both sides of the double-sided and double-sided positive lens of the sixth lens group G6.

The fourteenth surface r ₁₄ in the numerical data given later is a virtual surface provided on designed to prevent interference between the reflecting surface and the fourth lens unit G4, not any member exists. A reflective surface that bends the optical axis at a substantially right angle (for example, 90 °) is provided between the third lens group G3 and the virtual surface r ₁₄ at an angle of 45 ° with respect to the optical axis. The position is fixed integrally with the third lens group G3 during photographing.

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

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

Example 1
r ₁ = 10000.000 d ₁ = 1.22 n _d1 = 1.84666 ν _d1 = 23.78
r ₂ = 54.315 d ₂ = 2.28 n _d2 = 1.48749 ν _d2 = 70.23
r ₃ = -168.262 d ₃ = 0.15
r ₄ = 17.458 (aspherical surface) d ₄ = 3.92 n _d3 = 1.51633 ν _d3 = 64.14
r ₅ = -80.401 (aspherical surface) d ₅ = (variable)
r ₆ = -41.373 d ₆ = 0.85 n _d4 = 1.74320 ν _d4 = 49.34
r ₇ = 5.913 (aspherical surface) d ₇ = 2.74
r ₈ = -18.988 d ₈ = 0.63 n _d5 = 1.69680 ν _d5 = 55.53
r ₉ = -2001.711 d ₉ = 1.44 n _d6 = 1.92286 ν _d6 = 20.88
r ₁₀ = -32.133 d ₁₀ = (variable)
r ₁₁ = ∞ (aperture) d ₁₁ = 0.98
r ₁₂ = 119.255 d ₁₂ = 1.27 n _d7 = 1.66680 ν _d7 = 33.05
r ₁₃ = -37.684 d ₁₃ = 11.00
r ₁₄ = ∞ (virtual surface) d ₁₄ = (variable)
r ₁₅ = 11.075 (aspherical surface) d ₁₅ = 4.48 n _d8 = 1.49700 ν _d8 = 81.61
r ₁₆ = -12.821 (aspherical surface) d ₁₆ = 0.15
r ₁₇ = -48.898 d ₁₇ = 0.75 n _d9 = 1.88300 ν _d9 = 40.76
r ₁₈ = 22.800 d ₁₈ = 1.79 n _d10 = 1.67270 ν _d10 = 32.10
r ₁₉ = -1864.706 d ₁₉ = (variable)
r ₂₀ = 14.504 d ₂₀ = 3.12 n _d11 = 1.49700 ν _d11 = 81.61
r ₂₁ = -24.900 d ₂₁ = 0.70 n _d12 = 1.90366 ν _d12 = 31.31
r ₂₂ = 12.079 d ₂₂ = (variable)
r ₂₃ = 20.827 d ₂₃ = 2.71 n _d13 = 1.58313 ν _d13 = 59.46
r ₂₄ = -21.022 (aspherical surface) d ₂₄ = (variable)
r ₂₅ = ∞ d ₂₅ = 0.85 n _d14 = 1.54771 ν _d14 = 62.84
r ₂₆ = ∞ d ₂₆ = 0.50
r ₂₇ = ∞ d ₂₇ = 0.50 n _d15 = 1.51633 ν _d15 = 64.14
r ₂₈ = ∞ d ₂₈ = 0.60
r ₂₉ = ∞ (image plane)
Aspheric coefficient 4th surface K = 0.000
A ₄ = -1.76939 × 10 ^-5
A ₆ = 1.02257 × 10 ^-7
A ₈ = -4.28415 × 10 ^-10
A ₁₀ = -2.96963 × 10 ^-11
Fifth side K = 0.000
A ₄ = 3.87596 × 10 ^-6
A ₆ = 3.06743 × 10 ^-7
A ₈ = -5.34413 × 10 ^-9
A ₁₀ = 5.29943 × 10 ^-12
Surface 7 K = 0.000
A ₄ = -6.92555 × 10 ^-4
A ₆ = -3.29478 × 10 ^-6
A ₈ = -2.53249 × 10 ^-9
A ₁₀ = -2.34006 × 10 ^-8
15th face K = 0.000
A ₄ = -1.30651 × 10 ^-4
A ₆ = 1.26048 × 10 ^-6
A ₈ = -2.17108 × 10 ^-8
A ₁₀ = -8.42116 × 10 ^-13
16th surface K = 0.000
A ₄ = 1.23948 × 10 ^-4
A ₆ = 1.55067 × 10 ^-6
A ₈ = -1.91419 × 10 ^-8
A ₁₀ = 2.70402 × 10 ^-12
24th face K = 0.000
A ₄ = 1.03984 × 10 ^-4
A ₆ = -5.60430 × 10 ^-7
A ₈ = -1.90947 × 10 ^-8
A ₁₀ = 4.68567 × 10 ^-10
Zoom data (∞)
WE ST TE
f (mm) 5.93 18.63 58.25
F _NO 3.33 3.78 5.18
2ω (°) 64.05 21.38 7.07
d ₅ 0.52 10.75 17.93
d ₁₀ 13.77 3.68 0.51
d ₁₄ 8.65 1.17 0.99
d ₁₉ 0.61 4.10 7.05
d ₂₂ 3.80 5.21 11.91
d ₂₄ 8.71 11.28 1.80.

Example 2
r ₁ = 653.204 d ₁ = 1.26 n _d1 = 1.84666 ν _d1 = 23.78
r ₂ = 43.561 d ₂ = 3.37 n _d2 = 1.48749 ν _d2 = 70.23
r ₃ = -210.296 d ₃ = 0.15
r ₄ = 18.151 (aspherical surface) d ₄ = 4.62 n _d3 = 1.62299 ν _d3 = 58.12
r ₅ = -145.174 (aspherical surface) d ₅ = (variable)
r ₆ = -92.644 d ₆ = 0.90 n _d4 = 1.80610 ν _d4 = 40.92
r ₇ = 5.852 (aspherical surface) d ₇ = 2.86
r ₈ = -24.154 d ₈ = 0.60 n _d5 = 1.88300 ν _d5 = 40.76
r ₉ = 16.994 d ₉ = 1.95 n _d6 = 1.92286 ν _d6 = 20.88
r ₁₀ = -712.410 d ₁₀ = (variable)
r ₁₁ = ∞ (aperture) d ₁₁ = 1.00
r ₁₂ = -601.720 d ₁₂ = 1.19 n _d7 = 1.80518 ν _d7 = 25.42
r ₁₃ = -33.661 d ₁₃ = 10.30
r ₁₄ = ∞ (virtual surface) d ₁₄ = (variable)
r ₁₅ = 13.760 (aspherical surface) d ₁₅ = 7.78 n _d8 = 1.61881 ν _d8 = 63.85
r ₁₆ = -12.950 d ₁₆ = 0.70 n _d9 = 1.90366 ν _d9 = 31.31
r ₁₇ = 86.120 d ₁₇ = 0.15
r ₁₈ = 16.484 d ₁₈ = 2.85 n _d10 = 1.58423 ν _d10 = 30.49
r ₁₉ = -28.611 (aspherical surface) d ₁₉ = (variable)
r ₂₀ = 19.360 d ₂₀ = 2.96 n _d11 = 1.48749 ν _d11 = 70.44
r ₂₁ = -21.122 d ₂₁ = 0.73 n _d12 = 2.00069 ν _d12 = 25.46
r ₂₂ = 18.596 d ₂₂ = (variable)
r ₂₃ = 27.717 (aspherical surface) d ₂₃ = 2.87 n _d13 = 1.52542 ν _d13 = 55.78
r ₂₄ = -14.958 (aspherical surface) d ₂₄ = (variable)
r ₂₅ = ∞ d ₂₅ = 0.85 n _d14 = 1.54771 ν _d14 = 62.84
r ₂₆ = ∞ d ₂₆ = 0.50
r ₂₇ = ∞ d ₂₇ = 0.50 n _d15 = 1.51633 ν _d15 = 64.14
r ₂₈ = ∞ d ₂₈ = 0.60
r ₂₉ = ∞ (image plane)
Aspheric coefficient 4th surface K = 0.000
A ₄ = 5.07069 × 10 ^-7
A ₆ = -1.07496 × 10 ^-7
A ₈ = -2.84760 × 10 ^-10
A ₁₀ = 1.57752 × 10 ^-12
Fifth side K = 0.000
A ₄ = 2.50503 × 10 ^-5
A ₆ = -2.66972 × 10 ^-7
A ₈ = 1.18662 × 10 ^-9
A ₁₀ = -1.69886 × 10 ^-12
Surface 7 K = 0.000
A ₄ = -4.89796 × 10 ^-4
A ₆ = -5.38468 × 10 ^-6
A ₈ = -2.51002 × 10 ^-9
A ₁₀ = -1.67791 × 10 ^-8
15th face K = 0.000
A ₄ = 3.28920 × 10 ^-5
A ₆ = 1.13870 × 10 ^-6
A ₈ = -1.30908 × 10 ^-8
A ₁₀ = 1.67483 × 10 ^-10
19th face K = 0.000
A ₄ = 1.74075 × 10 ^-4
A ₆ = 2.01408 × 10 ^-6
A ₈ = -3.08884 × 10 ^-8
A ₁₀ = 4.92822 × 10 ^-10
Surface 23 K = 0.000
A ₄ = -4.08561 × 10 ^-4
A ₆ = 1.38541 × 10 ^-6
A ₈ = -1.40860 × 10 ^-7
A ₁₀ = -3.27813 × 10 ^-10
24th face K = 0.000
A ₄ = -2.49782 × 10 ^-4
A ₆ = 8.61175 × 10 ^-7
A ₈ = -1.05973 × 10 ^-7
A ₁₀ = -2.81721 × 10 ^-11
Zoom data (∞)
WE ST TE
f (mm) 4.75 14.68 46.38
F _NO 3.46 3.99 4.99
2ω (°) 79.46 27.08 8.95
d ₅ 0.51 9.56 16.39
d ₁₀ 13.48 4.67 0.98
d ₁₄ 9.18 1.25 0.95
d ₁₉ 1.39 5.16 9.55
d ₂₂ 4.63 6.67 9.63
d ₂₄ 6.17 8.29 1.25.

Example 3
r ₁ = 633.665 d ₁ = 1.22 n _d1 = 1.84666 ν _d1 = 23.78
r ₂ = 50.330 d ₂ = 2.80 n _d2 = 1.48749 ν _d2 = 70.23
r ₃ = -80.739 d ₃ = 0.15
r ₄ = 19.524 (aspherical surface) d ₄ = 3.17 n _d3 = 1.58913 ν _d3 = 61.28
r ₅ = 14313.525 (aspherical surface) d ₅ = (variable)
r ₆ = -229.738 d ₆ = 0.84 n _d4 = 1.74320 ν _d4 = 49.34
r ₇ = 7.215 (aspherical surface) d ₇ = 2.69
r ₈ = -16.087 d ₈ = 0.78 n _d5 = 1.72916 ν _d5 = 54.68
r ₉ = 23.566 d ₉ = 1.56 n _d6 = 1.92286 ν _d6 = 20.88
r ₁₀ = 365.979 d ₁₀ = (variable)
r ₁₁ = ∞ (aperture) d ₁₁ = 1.00
r ₁₂ = 98.169 d ₁₂ = 1.22 n _d7 = 1.83481 ν _d7 = 42.71
r ₁₃ = -58.012 d ₁₃ = 10.30
r ₁₄ = ∞ (virtual surface) d ₁₄ = (variable)
r ₁₅ = 10.954 (aspherical surface) d ₁₅ = 4.87 n _d8 = 1.49700 ν _d8 = 81.61
r ₁₆ = -10.658 (aspherical surface) d ₁₆ = 0.15
r ₁₇ = -24.588 d ₁₇ = 0.75 n _d9 = 1.88300 ν _d9 = 40.76
r ₁₈ = 31.642 d ₁₈ = 1.97 n _d10 = 1.67270 ν _d10 = 32.10
r ₁₉ = -45.379 d ₁₉ = (variable)
r ₂₀ = 29.701 d ₂₀ = 3.06 n _d11 = 1.49700 ν _d11 = 81.61
r ₂₁ = -14.406 d ₂₁ = 0.70 n _d12 = 1.90366 ν _d12 = 31.31
r ₂₂ = 20.241 d ₂₂ = (variable)
r ₂₃ = 88.742 (aspherical surface) d ₂₃ = 2.54 n _d13 = 1.58313 ν _d13 = 59.46
r ₂₄ = -13.428 (aspherical surface) d ₂₄ = (variable)
r ₂₅ = ∞ d ₂₅ = 0.85 n _d14 = 1.54771 ν _d14 = 62.84
r ₂₆ = ∞ d ₂₆ = 0.50
r ₂₇ = ∞ d ₂₇ = 0.50 n _d15 = 1.51633 ν _d15 = 64.14
r ₂₈ = ∞ d ₂₈ = 0.60
r ₂₉ = ∞ (image plane)
Aspheric coefficient 4th surface K = 0.000
A ₄ = -3.72162 × 10 ^-6
A ₆ = -8.21416 × 10 ^-8
A ₈ = -7.59290 × 10 ^-10
A ₁₀ = -3.86636 × 10 ^-12
Fifth side K = 0.000
A ₄ = 6.32385 × 10 ^-6
A ₆ = -1.23106 × 10 ^-7
A ₈ = -7.39925 × 10 ^-10
A ₁₀ = 9.42069 × 10 ^-13
Surface 7 K = 0.000
A ₄ = -1.94793 × 10 ^-4
A ₆ = 2.03756 × 10 ^-6
A ₈ = -4.21904 × 10 ^-8
A ₁₀ = -2.05749 × 10 ^-9
15th face K = 0.148
A ₄ = -1.53405 × 10 ^-4
A ₆ = 1.14566 × 10 ^-6
A ₈ = -2.68332 × 10 ^-8
A ₁₀ = -6.55570 × 10 ^-10
16th surface K = 0.000
A ₄ = 1.88758 × 10 ^-4
A ₆ = 2.90402 × 10 ^-6
A ₈ = -8.02417 × 10 ^-8
A ₁₀ = 2.85326 × 10 ^-10
Surface 23 K = 0.000
A ₄ = -2.31264 × 10 ^-4
A ₆ = 8.09133 × 10 ^-6
A ₈ = -4.77171 × 10 ^-7
A ₁₀ = 1.29270 × 10 ^-8
24th face K = 0.000
A ₄ = -1.02238 × 10 ^-4
A ₆ = 4.65634 × 10 ^-6
A ₈ = -3.32015 × 10 ^-7
A ₁₀ = 9.70259 × 10 ^-9
Zoom data (∞)
WE ST TE
f (mm) 5.92 17.67 57.19
F _NO 3.50 3.95 5.14
2ω (°) 67.35 22.80 7.28
d ₅ 0.56 10.49 18.34
d ₁₀ 15.49 5.33 1.03
d ₁₄ 8.02 0.83 0.94
d ₁₉ 1.40 4.31 8.92
d ₂₂ 3.94 4.89 10.61
d ₂₄ 8.80 12.12 1.69.

Example 4
r ₁ = 673.793 d ₁ = 1.30 n _d1 = 1.84666 ν _d1 = 23.78
r ₂ = 52.632 d ₂ = 2.77 n _d2 = 1.48749 ν _d2 = 70.23
r ₃ = -106.741 d ₃ = 0.15
r ₄ = 20.563 (aspherical surface) d ₄ = 3.26 n _d3 = 1.58913 ν _d3 = 61.28
r ₅ = -393.064 (aspherical surface) d ₅ = (variable)
r ₆ = -165.505 d ₆ = 0.90 n _d4 = 1.74320 ν _d4 = 49.34
r ₇ = 7.887 (aspherical surface) d ₇ = 2.98
r ₈ = -19.686 d ₈ = 0.83 n _d5 = 1.77250 ν _d5 = 49.60
r ₉ = 19.904 d ₉ = 1.71 n _d6 = 1.92286 ν _d6 = 20.88
r ₁₀ = 212.774 d ₁₀ = (variable)
r ₁₁ = ∞ (aperture) d ₁₁ = 1.00
r ₁₂ = 142.798 d ₁₂ = 1.33 n _d7 = 1.60311 ν _d7 = 60.64
r ₁₃ = -30.008 d ₁₃ = 11.00
r ₁₄ = ∞ (virtual surface) d ₁₄ = (variable)
r ₁₅ = 13.668 (aspherical surface) d ₁₅ = 4.51 n _d8 = 1.49700 ν _d8 = 81.61
r ₁₆ = -14.634 (aspherical surface) d ₁₆ = 0.15
r ₁₇ = -68.494 d ₁₇ = 0.85 n _d9 = 1.83481 ν _d9 = 42.71
r ₁₈ = 33.935 d ₁₈ = 1.70 n _d10 = 1.67270 ν _d10 = 32.10
r ₁₉ = -201.057 d ₁₉ = (variable)
r ₂₀ = 27.102 d ₂₀ = 3.57 n _d11 = 1.49700 ν _d11 = 81.61
r ₂₁ = -13.854 d ₂₁ = 0.78 n _d12 = 1.90366 ν _d12 = 31.31
r ₂₂ = 25.010 d ₂₂ = (variable)
r ₂₃ = 154.360 (aspherical surface) d ₂₃ = 2.67 n _d13 = 1.58913 ν _d13 = 61.28
r ₂₄ = -13.456 (aspherical surface) d ₂₄ = (variable)
r ₂₅ = ∞ d ₂₅ = 0.85 n _d14 = 1.54771 ν _d14 = 62.84
r ₂₆ = ∞ d ₂₆ = 0.50
r ₂₇ = ∞ d ₂₇ = 0.50 n _d15 = 1.51633 ν _d15 = 64.14
r ₂₈ = ∞ d ₂₈ = 0.60
r ₂₉ = ∞ (image plane)
Aspheric coefficient 4th surface K = 0.000
A ₄ = 1.31074 × 10 ^-6
A ₆ = -7.65863 × 10 ^-8
A ₈ = -2.61029 × 10 ^-10
A ₁₀ = 1.36136 × 10 ^-12
Fifth side K = 0.000
A ₄ = 1.31905 × 10 ^-5
A ₆ = -1.45275 × 10 ^-7
A ₈ = 4.13701 × 10 ^-10
A ₁₀ = -9.48730 × 10 ^-14
Surface 7 K = 0.000
A ₄ = -1.79208 × 10 ^-4
A ₆ = 4.85330 × 10 ^-6
A ₈ = -2.03327 × 10 ^-7
A ₁₀ = 2.13211 × 10 ^-9
15th surface K = -0.054
A ₄ = -1.06426 × 10 ^-4
A ₆ = 1.35813 × 10 ^-6
A ₈ = -2.53397 × 10 ^-8
A ₁₀ = -2.47379 × 10 ^-10
16th surface K = 0.000
A ₄ = 4.18820 × 10 ^-5
A ₆ = 1.96264 × 10 ^-6
A ₈ = -4.33068 × 10 ^-8
A ₁₀ = 0
Surface 23 K = 0.000
A ₄ = -1.83225 × 10 ^-4
A ₆ = 7.52358 × 10 ^-6
A ₈ = -1.22202 × 10 ^-7
A ₁₀ = 3.29718 × 10 ^-9
24th face K = 0.000
A ₄ = -5.69683 × 10 ^-5
A ₆ = 5.02624 × 10 ^-6
A ₈ = -8.57219 × 10 ^-8
A ₁₀ = 3.13423 × 10 ^-9
Zoom data (∞)
WE ST TE
f (mm) 6.32 18.30 60.99
F _NO 3.56 3.99 5.50
2ω (°) 67.21 23.37 7.33
d ₅ 0.59 10.85 19.15
d ₁₀ 15.45 5.17 1.10
d ₁₄ 9.32 1.43 1.00
d ₁₉ 1.39 4.54 8.82
d ₂₂ 3.84 5.62 12.13
d ₂₄ 9.25 12.22 1.85.

Example 5
r ₁ = 633.665 d ₁ = 1.22 n _d1 = 1.84666 ν _d1 = 23.78
r ₂ = 50.904 d ₂ = 2.71 n _d2 = 1.48749 ν _d2 = 70.23
r ₃ = -97.884 d ₃ = 0.15
r ₄ = 20.036 (aspherical surface) d ₄ = 3.27 n _d3 = 1.58913 ν _d3 = 61.28
r ₅ = -424.570 (aspherical surface) d ₅ = (variable)
r ₆ = -154.607 d ₆ = 0.85 n _d4 = 1.74320 ν _d4 = 49.34
r ₇ = 7.037 (aspherical surface) d ₇ = 3.13
r ₈ = -13.249 d ₈ = 0.65 n _d5 = 1.72916 ν _d5 = 54.68
r ₉ = -400.246 d ₉ = 1.44 n _d6 = 1.92286 ν _d6 = 20.88
r ₁₀ = -31.893 d ₁₀ = (variable)
r ₁₁ = ∞ (aperture) d ₁₁ = 0.99
r ₁₂ = -2601.620 d ₁₂ = 1.14 n _d7 = 1.90366 ν _d7 = 31.31
r ₁₃ = -48.956 d ₁₃ = 11.00
r ₁₄ = ∞ (virtual surface) d ₁₄ = (variable)
r ₁₅ = 11.696 (aspherical surface) d ₁₅ = 4.30 n _d8 = 1.49700 ν _d8 = 81.61
r ₁₆ = -13.542 (aspherical surface) d ₁₆ = 0.15
r ₁₇ = -186.492 d ₁₇ = 0.75 n _d9 = 1.88300 ν _d9 = 40.76
r ₁₈ = 18.191 d ₁₈ = 1.76 n _d10 = 1.67270 ν _d10 = 32.10
r ₁₉ = 88.947 d ₁₉ = (variable)
r ₂₀ = 13.139 d ₂₀ = 3.44 n _d11 = 1.49700 ν _d11 = 81.61
r ₂₁ = -22.439 d ₂₁ = 0.70 n _d12 = 1.90366 ν _d12 = 31.31
r ₂₂ = 12.447 d ₂₂ = (variable)
r ₂₃ = 37.219 d ₂₃ = 2.40 n _d13 = 1.58913 ν _d13 = 61.28
r ₂₄ = -15.857 (aspherical surface) d ₂₄ = (variable)
r ₂₅ = ∞ d ₂₅ = 0.85 n _d14 = 1.54771 ν _d14 = 62.84
r ₂₆ = ∞ d ₂₆ = 0.50
r ₂₇ = ∞ d ₂₇ = 0.50 n _d15 = 1.51633 ν _d15 = 64.14
r ₂₈ = ∞ d ₂₈ = 0.60
r ₂₉ = ∞ (image plane)
Aspheric coefficient 4th surface K = 0.000
A ₄ = -5.42983 × 10 ^-6
A ₆ = 1.38492 × 10 ^-8
A ₈ = -1.14651 × 10 ^-10
A ₁₀ = -1.84230 × 10 ^-11
Fifth side K = 0.000
A ₄ = 4.72650 × 10 ^-6
A ₆ = 8.65089 × 10 ^-8
A ₈ = -2.41488 × 10 ^-9
A ₁₀ = -1.57422 × 10 ^-12
Surface 7 K = 0.000
A ₄ = -2.92122 × 10 ^-4
A ₆ = 4.31976 × 10 ^-6
A ₈ = -2.28965 × 10 ^-7
A ₁₀ = 3.36891 × 10 ^-10
Surface 15 K = 0.597
A ₄ = -1.90173 × 10 ^-4
A ₆ = 1.68973 × 10 ^-6
A ₈ = -4.82919 × 10 ^-8
A ₁₀ = -2.13859 × 10 ^-11
16th surface K = 0.000
A ₄ = 9.02659 × 10 ^-5
A ₆ = 2.98286 × 10 ^-6
A ₈ = -7.15741 × 10 ^-8
A ₁₀ = 4.04396 × 10 ^-10
24th face K = 0.000
A ₄ = 1.14189 × 10 ^-4
A ₆ = -4.67268 × 10 ^-6
A ₈ = 1.49193 × 10 ^-7
A ₁₀ = -1.97043 × 10 ^-9
Zoom data (∞)
WE ST TE
f (mm) 5.93 17.72 57.17
F _NO 3.29 3.74 5.12
2ω (°) 66.47 22.63 7.27
d ₅ 0.53 10.81 18.72
d ₁₀ 15.11 4.51 0.49
d ₁₄ 8.16 1.50 1.00
d ₁₉ 0.71 4.07 8.96
d ₂₂ 4.36 4.96 10.54
d ₂₄ 8.85 11.58 1.57.

Example 6
r ₁ = 653.204 d ₁ = 1.22 n _d1 = 1.84666 ν _d1 = 23.78
r ₂ = 45.090 d ₂ = 2.75 n _d2 = 1.48749 ν _d2 = 70.23
r ₃ = -1318.530 d ₃ = 0.15
r ₄ = 17.489 (aspherical surface) d ₄ = 3.89 n _d3 = 1.58913 ν _d3 = 61.28
r ₅ = -89.343 (aspherical surface) d ₅ = (variable)
r ₆ = -69.566 d ₆ = 0.85 n _d4 = 1.74320 ν _d4 = 49.34
r ₇ = 5.831 (aspherical surface) d ₇ = 3.24
r ₈ = -17.167 d ₈ = 0.65 n _d5 = 1.72916 ν _d5 = 54.68
r ₉ = 36.171 d ₉ = 1.67 n _d6 = 1.92286 ν _d6 = 20.88
r ₁₀ = -70.564 d ₁₀ = (variable)
r ₁₁ = ∞ (aperture) d ₁₁ = 0.99
r ₁₂ = 270.431 d ₁₂ = 1.22 n _d7 = 1.80610 ν _d7 = 40.92
r ₁₃ = -40.685 d ₁₃ = 10.30
r ₁₄ = ∞ (virtual surface) d ₁₄ = (variable)
r ₁₅ = 10.699 (aspherical surface) d ₁₅ = 5.20 n _d8 = 1.49700 ν _d8 = 81.61
r ₁₆ = -9.876 (aspherical surface) d ₁₆ = 0.30
r ₁₇ = -17.644 d ₁₇ = 0.75 n _d9 = 1.88300 ν _d9 = 40.76
r ₁₈ = 43.893 d ₁₈ = 1.92 n _d10 = 1.67270 ν _d10 = 32.10
r ₁₉ = -34.846 d ₁₉ = (variable)
r ₂₀ = 24.139 d ₂₀ = 3.18 n _d11 = 1.49700 ν _d11 = 81.61
r ₂₁ = -14.346 d ₂₁ = 0.70 n _d12 = 1.90366 ν _d12 = 31.31
r ₂₂ = 20.703 d ₂₂ = (variable)
r ₂₃ = 78.738 (aspherical surface) d ₂₃ = 2.44 n _d13 = 1.58313 ν _d13 = 59.46
r ₂₄ = -13.952 (aspherical surface) d ₂₄ = (variable)
r ₂₅ = ∞ d ₂₅ = 0.85 n _d14 = 1.54771 ν _d14 = 62.84
r ₂₆ = ∞ d ₂₆ = 0.50
r ₂₇ = ∞ d ₂₇ = 0.50 n _d15 = 1.51633 ν _d15 = 64.14
r ₂₈ = ∞ d ₂₈ = 0.60
r ₂₉ = ∞ (image plane)
Aspheric coefficient 4th surface K = 0.000
A ₄ = -1.16015 × 10 ^-5
A ₆ = -4.58545 × 10 ^-8
A ₈ = -3.84761 × 10 ^-10
A ₁₀ = -3.35581 × 10 ^-12
Fifth side K = 0.000
A ₄ = 1.33373 × 10 ^-5
A ₆ = -4.99311 × 10 ^-8
A ₈ = -5.87507 × 10 ^-10
A ₁₀ = 1.02292 × 10 ^-12
Surface 7 K = 0.000
A ₄ = -5.20765 × 10 ^-4
A ₆ = -2.71776 × 10 ^-6
A ₈ = -1.24289 × 10 ^-7
A ₁₀ = -1.36863 × 10 ^-8
Surface 15 K = -0.134
A ₄ = -1.02927 × 10 ^-4
A ₆ = 1.88604 × 10 ^-6
A ₈ = -3.12601 × 10 ^-8
A ₁₀ = -5.20707 × 10 ^-10
16th surface K = 0.000
A ₄ = 2.18544 × 10 ^-4
A ₆ = 4.30526 × 10 ^-6
A ₈ = -1.07154 × 10 ^-7
A ₁₀ = 6.47450 × 10 ^-10
Surface 23 K = 0.000
A ₄ = -4.32618 × 10 ^-4
A ₆ = 2.38110 × 10 ^-5
A ₈ = -1.34005 × 10 ^-6
A ₁₀ = 2.83017 × 10 ^-8
24th face K = 0.000
A ₄ = -2.89557 × 10 ^-4
A ₆ = 1.99791 × 10 ^-5
A ₈ = -1.10217 × 10 ^-6
A ₁₀ = 2.24820 × 10 ^-8
Zoom data (∞)
WE ST TE
f (mm) 5.45 16.62 52.65
F _NO 3.45 3.90 4.99
2ω (°) 71.40 24.07 7.92
d ₅ 0.51 9.94 16.76
d ₁₀ 14.78 5.07 1.03
d ₁₄ 8.04 1.00 0.94
d ₁₉ 1.38 4.23 8.75
d ₂₂ 3.93 4.95 9.98
d ₂₄ 8.25 11.41 1.93.

  Aberration diagrams at the time of focusing on an object point at infinity in Examples 1 to 6 are shown in FIGS. In these aberration diagrams, (a) is the wide angle end, (b) is the intermediate state, (c) is the spherical aberration (SA), astigmatism (AS), distortion (DT), and lateral chromatic aberration (CC) at the telephoto end. ). In each figure, “ω” indicates a half angle of view.

  The values of conditional expressions (1) to (2) in Examples 1 to 6 are as follows.

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6
(1) f _t / f ₂ -8.72 -8.97 -9.00 -8.90 -8.03 -8.96
(2) f _t / f _tg12 -1.19 -1.42 -1.39 -1.34 -1.15 -1.32
.

  In FIG. 13, in the variable magnification optical system of Example 3, the surface reflection mirror R that bends the optical axis at a substantially right angle (for example, 90 °) between the third lens group G3 and the fourth lens group G4. Sectional drawing in the wide-angle end (a) and telephoto end (c) at the time of arrange | positioning at an angle of 45 degrees with respect to is shown. The same applies to the variable magnification optical systems of the other embodiments.

  Next, FIG. 14 shows an example of a mechanical configuration for housing the variable magnification optical system of the present invention in which the surface reflection mirror R as described above is arranged. FIG. 14A is a cross-sectional view when the optical system is photographed, and FIG. 14B is a cross-sectional view when the optical system is housed.

  The first lens frame 11, the first cam frame 14, the second lens frame 12, the second cam frame 15, and the third lens frame 13 are concentrically fitted from the outer side to the inner side around the optical axis. The first lens group G1, the second lens group G2, and the third lens group G3 are held by the first lens frame 11, the second lens frame 12, and the third lens frame 13, respectively. The aperture stop S is held by the third lens frame 13. Each of the first lens group G1, the second lens group G2, and the third lens group G3 includes a key that guides movement in the optical axis direction.

  Each of the first cam frame 14 and the second cam frame 15 is in a state in which a part of the outer peripheral surface of the lower end is fitted to a part of the inner peripheral surface of the outer frame 16, and the cam pin disposed on the outer peripheral surface of each lower end A cam groove provided on the inner peripheral surface of the frame 16 is engaged.

  Further, a retaining piece 32 is adhered to the upper surface of the outer frame 16 with an ultraviolet curable adhesive or the like. A protrusion 31 is provided at the lower part of the first lens frame 11.

  The first lens frame 11 is configured to move in the optical axis direction following the movement of the first cam frame 14 in the optical axis direction.

  Further, a cam groove provided on the inner peripheral surface of the first cam frame 14 and a cam pin disposed on the outer peripheral surface of the second lens frame 12 are engaged.

  The cam groove provided on the inner peripheral surface of the second cam frame 15 and the cam pin disposed on the outer peripheral surface of the third lens frame 13 are engaged.

  Therefore, the first lens frame 11 and the second lens frame 12 are moved in the optical axis direction along a predetermined locus with the rotation of the first cam frame 14, and the third lens frame 13 is moved with the rotation of the second cam frame 15. It is moved to a predetermined position in the optical axis direction. In order to maintain the state shown in FIG. 14A, the protrusion 31 of the first lens frame 11 is formed so that the first lens frame 11 does not protrude from the first cam frame 14 and the outer frame 16. The movement is restricted by abutting against the 16 retaining pieces 32.

  The first cam frame 14 and the second cam frame 15 are connected to a motor (not shown).

  A rotation lever 17 having a rotation fulcrum axis P, which includes a torsion spring and a support shaft provided on the outer frame 16, is disposed immediately below the third lens frame 13. The reflection mirror R is joined.

  The optical axis incident from the object side is bent by about 90 ° by the reflecting mirror R on the image sensor side of the third lens group G3, and enters the fourth lens group G4. On the side surface of the outer frame 16, an opening is provided perpendicular to the optical axis of the fourth lens group G4. Furthermore, a fifth lens group G5 and a sixth lens group G6 that move independently in the optical axis direction are arranged between the fourth lens group G4 and the image sensor D.

  The rotation of the rotation shaft of the motor is transmitted to the engaging portion via a screw, and the first lens frame 11, the second lens frame 12, and the third lens frame 13 move along the key shaft. A driving motor for moving the first lens frame 11 and the second lens frame 12 along the key axis, and a driving motor for moving the third lens frame 13 to a predetermined position along the key axis. The motor can also be provided separately.

  At this time, the fourth lens group G4, the fifth lens group G5, and the sixth lens group G6 are moved from the opening of the outer frame 16 to the image sensor D side from the time of storage to the time of shooting or from the time of shooting to the time of storage. The first cam frame 14 and the second cam frame 15 are lowered. Further, in the state at the time of photographing, the fourth lens group G4, the fifth lens group G5, and the sixth lens group G6 may be arranged on the imaging element D side with respect to the opening. Further, a part of the inner side of the second cam frame 15 abuts on the rotation lever 17, the second cam frame 15 is further lowered, and the urging force is applied to the rotation fulcrum shaft P of the rotation lever 17. Stops.

  The above is the operation of the zoom lens (variable magnification optical system) from photographing to storage. In addition, from the time of storage to the time of shooting, the motor drive shaft is reversely rotated to start the movement of the first cam frame 14 and the second cam frame 15, and the first lens frame 11, the second lens frame 12, and the second The three-lens frame 13 is moved from the housed state to the photographing state. The fourth lens group G4, the fifth lens group G5, and the sixth lens group G6 are moved to predetermined positions at the time of photographing in synchronization with a state where they are raised from the upper surface of the opening of the outer frame 16. When the first lens group G1, the second lens group G2, and the third lens group G3 are stopped at desired positions at the time of photographing, a state at the time of photographing is obtained. A technique similar to this configuration is described in FIG.

  Next, the relationship between the fourth lens group G4 and the fourth lens frame 18, the fifth lens group G4 and the fifth lens frame 19, and the sixth lens group G6 and the sixth lens frame 20 will be described.

  The fourth lens frame 18 is supported by an insertion hole through which one of the guide shafts 21 is inserted and supported, and a screw shaft 22 that is a rotation shaft of the motor M1. Thereby, when the motor M1 rotates, the fourth lens frame 18 moves in a direction along the optical axis.

  The fifth lens frame 19 and the sixth lens frame 20 are supported by insertion holes through which one of the guide shafts 21 is inserted and supported, and screw shafts 23 and 24 which are rotation axes of the motors M2 and M3, respectively. Thereby, when the motors M2 and M3 rotate, the fifth lens frame 19 and the sixth lens frame 20 move in the direction along the optical axis.

  Next, the operation from the shooting state to the storage state will be described. The fourth lens frame 18 that supports the fourth lens group G4, the fifth lens frame 19 that supports the fifth lens group G5, and the sixth lens frame 20 that supports the sixth lens group G6 move to the image sensor D side. Stop after. At this time, at the start of movement, after the fourth lens frame 18 moves to the left side from the outer frame 16, the first lens frame 11, the first cam frame 14 and the like are lowered so as not to collide with these frames.

FIG. 2 is a lens cross-sectional view at a wide-angle end (a), an intermediate state (b), and a telephoto end (c) when focusing on an object point at infinity, where the optical path of a variable magnification optical system according to Example 1 of the present invention is developed. FIG. 6 is a lens cross-sectional view similar to FIG. 1 of the variable magnification optical system according to Example 2 of the present invention. FIG. 5 is a lens cross-sectional view similar to FIG. 1 of the variable magnification optical system according to Example 3 of the present invention. FIG. 6 is a lens cross-sectional view similar to FIG. 1 of the variable magnification optical system according to Example 4 of the present invention. FIG. 6 is a lens cross-sectional view similar to FIG. 1 of a variable magnification optical system according to Example 5 of the present invention. FIG. 6 is a lens cross-sectional view similar to FIG. 1 of a variable magnification optical system according to Example 6 of the present invention. FIG. 6 is an aberration diagram at the wide-angle end (a), the intermediate state (b), and the telephoto end (c) when focusing on an object point at infinity according to Example 1. FIG. 10 is an aberration diagram similar to FIG. 7 of Example 2. FIG. 10 is an aberration diagram similar to FIG. 7 of Example 3. FIG. 10 is an aberration diagram similar to FIG. 7 of Example 4. FIG. 10 is an aberration diagram similar to FIG. 7 of Example 5. FIG. 10 is an aberration diagram similar to FIG. 7 of Example 6. It is sectional drawing in the wide-angle end (a) and telephoto end (c) in case the optical axis of the variable magnification optical system of Example 3 bends 90 degrees. It is a figure which shows an example of the mechanical structure for accommodation of the variable magnification optical system of this invention.

Explanation of symbols

G1 ... 1st lens group G2 ... 2nd lens group G3 ... 3rd lens group G4 ... 4th lens group G5 ... 5th lens group G6 ... 6th lens group S ... Aperture stop F ... Optical low pass filter C ... CCD Cover glass I ... CCD image plane R ... Reflection mirror P ... Rotating fulcrum axis D ... Imaging element M1, M2, M3 ... Motor 11 ... First lens frame 12 ... Second lens frame 13 ... Third lens frame 14 ... First 1 cam frame 15 ... second cam frame 16 ... outer frame 17 ... rotating lever 18 ... fourth lens frame 19 ... fifth lens frame 20 ... sixth lens frame 21 ... guide shafts 22, 23, 24 ... screw shafts 31 ... Protrusion 32 ... Retaining piece

Claims (5)

In order from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power and the largest zooming effect at the time of zooming, and fixed at the time of zooming having a shutter and an aperture stop. A third lens group having a positive refractive power, a fourth lens group having a positive refractive power, and a fifth lens group having a negative refractive power, and satisfying the following conditional expression: Variable magnification optical system.
−10 < _ft / f ₂ <−7 (1)
_{-1.8 ≦ f t / f tg12 ≦} -0.92 ··· (2)
Where f _t is the focal length of the entire system at the telephoto end,
f ₂ is the focal length of the second lens group
f _tg12 is the combined focal length of the first lens group and the second lens group at the telephoto end,
It is. 2. The variable magnification optical system according to claim 1, further comprising a reflecting member that bends the optical axis at a substantially right angle on the imaging surface side of the third lens group having a positive refractive power. The variable power optical system according to claim 2, wherein the reflecting member is a surface reflecting mirror. An imaging device comprising: the variable magnification optical system according to any one of claims 1 to 3; and an image pickup device that is disposed on an image side of the variable magnification optical system and converts an optical image into an electric signal. apparatus. The imaging apparatus according to claim 4, wherein a low-pass filter is disposed between the variable magnification optical system and the imaging element.

Images