JP2010134186A - Imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging apparatus that has an optical path reflection type zoom lens composed of at least five lens groups of positive, negative, positive, positive, and positive, which can easily made compact and ensure optical performance while ensuring a variable power ratio and a field angle. <P>SOLUTION: When zooming from a wide-angle end to a tele-photo end, the imaging apparatus fixes a first lens group having a reflecting member, and a third lens group to an imaging surface. A second lens group is moved to an image side at the tele-photo end with respect to the wide angle end. A fourth lens group moves toward the object side at the tele-photo end with respect to the wide-angle end, thereby changing the intervals between the lens groups. The first lens group has a negative lens component of negative refractive power, disposed closer to the object than the reflecting member, and a positive lens component of positive refractive power, disposed closer to an image than the reflecting member, and the positive lens component is a cemented lens component in which at least two lenses having different refractive powers and Abbe's numbers are cemented. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an imaging apparatus such as a digital camera or a video camera provided with a zoom lens having a reflecting member.

  In recent years, digital cameras and video cameras that photograph subjects using an image sensor such as a CCD or CMOS have become mainstream as portable imaging devices. Among them, digital cameras are not limited to a single category, but have a number of categories in a wide range from high-end and high-functional types to compact popular types.

  Users of compact and popular digital cameras have a desire to enjoy shooting in a wide range of scenes anytime, anywhere. Therefore, a digital camera of a type that is easy to carry in a small product, especially a pocket of clothes or a bag, is easy to carry, and is thin in the thickness direction is preferred. Therefore, a zoom lens used as a photographing lens is also required to be thin.

  In order to meet such needs, a zoom lens of a type that reflects a light path using a reflecting member has been proposed. For example, in Patent Document 1, in order from the object side, a first lens unit having a positive refractive power having a reflecting member, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a fourth lens having a positive refractive power. A zoom lens having a lens group and a fifth lens group having a positive refractive power and performing zooming mainly by movement of the second lens group and the fourth lens group is disclosed.

  A zoom lens having such a reflecting member is advantageous for reducing the thickness of the imaging device in the thickness direction. Further, the second lens group and the fourth lens group are provided with a zooming function by the refractive power distribution of each lens group as described above and the moving method of the lens group during zooming. Also, by giving the third lens group positive refracting power, the effective diameter of the fourth lens group can be easily reduced. In addition, by setting the fifth lens group to have a positive refractive power, the exit pupil can be easily separated from the image plane, and the configuration is suitable for an imaging apparatus using an electronic image sensor.

  In the zoom lens described above, two single lenses having a positive refractive power are arranged on the image side of the reflecting member of the first lens group, and various aberrations are corrected so that the zoom ratio is easily secured.

JP 2007-93980 A

  However, when two single lenses are arranged on the image side of the reflecting member in the first lens group as in the zoom lens described in Patent Document 1, each single lens is axially secured to ensure the rigidity of each single lens. A sufficient thickness is required. This is disadvantageous for downsizing the zoom lens.

  In addition, in order to reduce the occurrence of decentration aberration due to the mutual decentration of the two single lenses, it is necessary to severely integrate the accuracy of the two single lenses. In order to ensure mass productivity, it is necessary to suppress the sensitivity of optical performance degradation to manufacturing errors in the assembly process.

  The present invention has been made in view of the above, and has at least five lenses, positive, negative, positive, positive, and positive, which facilitates downsizing and ensuring optical performance while ensuring a zoom ratio and angle of view. It is an object of the present invention to provide an imaging apparatus including an optical path reflection type zoom lens having a group.

  In order to solve the above-described problems and achieve the object, an imaging apparatus of the present invention includes a zoom lens having a reflecting member having a reflecting surface that bends an optical path, and an image pickup surface that is disposed on the image side of the zoom lens. And an image sensor that converts an image formed on the imaging surface by the zoom lens into an electrical signal. The zoom lens, in order from the object side, has a first lens group having a positive refractive power having a reflecting member, and a negative lens group. A second lens group having a refractive power; 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 positive refractive power; from the wide-angle end to the telephoto end. During zooming, the first lens group and the third lens group are fixed with respect to the imaging surface, the second lens group is moved to the image side at the telephoto end with respect to the wide angle end, and the fourth lens group is at the wide angle end. Move to the object side at the telephoto end to change the distance between each lens group. The first lens group includes a negative lens component having a negative refractive power disposed on the object side of the reflecting member, and a positive lens component having a positive refractive power disposed on the image side of the reflecting member, and is positive. The lens component is a cemented lens component in which at least two lenses having different refractive indexes and Abbe numbers are cemented.

  With this configuration, it is possible to reduce the thickness in the thickness direction of the imaging apparatus, which is the direction incident from the object side, by reflecting the optical path by the reflecting member of the first lens group. The first lens group, the negative second lens group, the positive third lens group, the positive fourth lens group, and the positive fifth lens group are arranged in this order from the object side. The third lens group is fixed with respect to the imaging surface, and the second lens group and the fourth lens group are moved as described above during zooming.

  Thereby, it is possible to share the variable magnification burden between the second lens group and the fourth lens group while keeping the total length constant. In addition, the presence of the fixed third lens group is advantageous in reducing the size and aberration of the fourth lens group in the radial direction. By disposing the fifth lens unit having positive refracting power, the exit pupil can be moved away from the image plane, and image quality deterioration due to the incidence of light on the imaging surface at a large incident angle can be reduced.

  Further, if a negative lens component having a negative refractive power is disposed on the object side of the reflecting member and a positive lens component having a positive refractive power is disposed on the image side of the reflecting member, it becomes easier to correct aberrations and the first lens group It functions like a wide conversion lens and is advantageous for securing the angle of view at the wide-angle end. In order to increase the zoom ratio, it is preferable to sufficiently secure the positive refracting power of the first lens group and sufficiently ensure the multiplication function by the second lens group. On the other hand, if it is attempted to secure the angle of view or the zoom ratio, the refractive power of the positive lens component tends to increase.

  Therefore, the present invention is characterized in that the positive lens component of the first lens group is a cemented lens component in which at least two lenses having different refractive indices and Abbe numbers are cemented. In the first lens group, the positive lens component positioned on the image side of the reflecting member is the above-described cemented lens component, which is advantageous for downsizing the first lens group and reducing various aberrations such as color coma. .

  Also, by joining a plurality of lenses, rigidity can be ensured even if the thickness of any one of the lenses is reduced, which is advantageous for downsizing the first lens group. Further, it becomes difficult for the lenses to be decentered by joining a plurality of lenses, which is effective in improving the efficiency during assembly.

  The lens component is a lens body having only two refracting surfaces in contact with air, that is, an object side surface and an image side surface, and means a single lens or a cemented lens.

  In addition, when the zoom lens has a focusing mechanism, the zoom lens has a configuration in which the lens is focused on the farthest distance. Similarly, in the following configurations, when the zoom lens has a focusing mechanism, it is configured in a state in which it is focused on the farthest distance.

  In the above-described invention, it is more preferable to satisfy one or more items of the configuration described below.

  In the imaging device of the present invention, the cemented lens component is a biconvex lens component, and the cemented lens component has a biconvex lens having a biconvex shape on the optical axis and a concave surface facing the biconvex lens side on the optical axis. In addition, it is preferable that the total number of lens components disposed on the image side of the reflecting member is 1 in the first lens group.

  The positive refractive power of the cemented lens component can be shared by a plurality of lens surfaces, which is advantageous for securing the positive refractive power of the cemented lens component and reducing spherical aberration. Further, by setting the total number of lens components on the image side of the reflecting member in the first lens group to 1, it is advantageous for reducing the size of the first lens group.

  In the imaging device of the present invention, the total number of lenses in the cemented lens component is preferably 2. Thereby, the number of constituent lenses can be saved, which is advantageous for downsizing and cost reduction.

  In the imaging apparatus of the present invention, it is preferable that the cemented lens component has a plurality of aspheric lenses in which aspheric surfaces are cemented together. As a result, the cemented surface can be made aspherical, which is advantageous in improving the correction function of various aberrations caused by the aspherical surface, particularly high-order coma at the telephoto end.

  Furthermore, in the imaging device of the present invention, it is preferable that the total number of reflecting surfaces in the zoom lens is 1. When the total number is 1, it is advantageous for downsizing by saving space in the zoom lens and for reducing cost by saving the number of reflecting members.

  In the image pickup apparatus of the present invention, the reflecting member in the first lens group is preferably a prism having an internal reflection surface and a refractive index exceeding 1.3. According to this configuration, the refractive index of the medium of the reflecting member can be used, and the effective diameter of the prism can be reduced, which is advantageous for downsizing the first lens group.

In the imaging apparatus of the present invention, it is preferable that the cemented lens component in the first lens group is a biconvex lens component, and satisfies the following conditional expression (1).
5.0 <(| r ₁ | + | r ₂ |) / d ₁ <24.0 (1)
However,
r ₁ is the paraxial radius of curvature of the object side surface of the cemented lens component,
r ₂ is the paraxial radius of curvature d ₁ of the image side surface of the cemented lens component, and d ₁ is the thickness of the cemented lens component on the optical axis.

  With such a configuration, the positive refractive power of the cemented lens component can be shared by a plurality of lens surfaces, which is advantageous for securing the positive refractive power of the cemented lens component and reducing spherical aberration.

  Conditional expression (1) prescribes a preferable paraxial radius of curvature and thickness on the optical axis of the object side surface and the image side surface of the biconvex cemented lens component. Avoiding falling below the lower limit of conditional expression (1) and preventing the curvature of the object side surface and the image side surface from becoming too large is advantageous for correcting off-axis aberrations and chromatic aberration. The positive refractive power of the cemented lens component is ensured by ensuring the thickness on the optical axis of the cemented lens component and the positive refractive power of both the object side surface and the image side surface without exceeding the upper limit of conditional expression (1). This is advantageous for correcting spherical aberration when the positive refractive power is secured.

In the imaging apparatus of the present invention, it is preferable that the cemented lens component in the first lens group satisfies the following conditional expression (2).
ν _dave > 28.0 (2)
However,
ν _dave is an average value of the Abbe number of each lens in the cemented lens component.

  Conditional expression (2) specifies preferable conditions for the Abbe number of each lens in the cemented lens component in the first lens group. By making sure that the lower limit of conditional expression (2) is not exceeded, lens dispersion in the cemented lens component can be reduced as a whole, and correction of chromatic aberration is facilitated.

Furthermore, in the imaging apparatus of the present invention, it is preferable that the second lens group and the third lens group satisfy the following conditional expression (3).
0.001 <| f _2g / f _3g | <0.40 (3)
However,
f _2g is the focal length of the second lens group,
f _3g is the focal length of the third lens group.

  Conditional expression (3) specifies a preferable refractive power balance of the focal lengths of the second lens group and the third lens group.

  By making sure that the lower limit of conditional expression (3) is not exceeded, the refractive power of the second lens group can be suppressed moderately, the positive refractive power of the third lens group can be secured, aberration correction, and downsizing of the fourth lens group. Is advantageous.

  By not exceeding the upper limit of conditional expression (3), the positive refractive power of the third lens group is moderately suppressed, which is advantageous for reducing the number of lenses of the third lens. Alternatively, the refractive power of the second lens group can be secured, and the amount of movement of the second lens group can be reduced, which is advantageous for downsizing.

  In the imaging apparatus of the present invention, since it is advantageous for reducing aberrations in the first lens group, the first lens group has a positive refracting power that satisfies the following conditional expression (4) to ensure a variable power ratio or a small size. It is preferable to carry out.

In the imaging device of the present invention, it is preferable that the first lens group satisfies the following conditional expression (4).
1.0 <f _1g / f _w <4.0 (4)
However,
f _1g is the focal length of the first lens group,
_fw is the focal length of the entire zoom lens system at the wide angle end.

  Conditional expression (4) specifies a preferable focal length of the first lens group.

  By making sure that the lower limit of conditional expression (4) is not exceeded, off-axis aberrations and chromatic aberration can be easily corrected. By making sure that the upper limit of conditional expression (4) is not exceeded, it is easy to secure the zooming function by the second lens group, which is advantageous for securing the zooming ratio.

  In addition, since the imaging apparatus of the present invention is advantageous for ensuring both the positive refracting power of the first lens group and reducing the size, it is preferable to use a zoom lens having an optical path length that satisfies the following conditional expression (5). .

In the image pickup apparatus of the present invention, it is preferable that the zoom lens satisfies the following conditional expression (5).
0.5 <D / _ft <3.0 (5)
However,
D is the optical path length along the optical axis from the object side refractive surface to the imaging surface of the most object side lens in the zoom lens,
f _t is the focal length of the entire zoom lens system at the telephoto end.

  By securing the optical path length so as not to fall below the lower limit of the conditional expression (5), it becomes easy to secure a moving space for zooming. By not exceeding the upper limit of conditional expression (5), it is advantageous for downsizing of the imaging device.

In the image pickup apparatus of the present invention, it is preferable that the zoom lens satisfies the following conditional expression (6).
3.8 < _ft / _fw <10.0 (6)
However,
_ft is the focal length of the entire zoom lens system at the telephoto end,
_fw is the focal length of the entire zoom lens system at the wide angle end.

  Conditional expression (6) specifies a preferable zoom ratio of the zoom lens.

  If the zoom ratio is secured so as not to fall below the lower limit of conditional expression (6), the range of expressions in wide-angle shooting and telephoto shooting is preferably increased. By making sure that the upper limit of conditional expression (6) is not exceeded, it is advantageous for miniaturization of the zoom lens.

  In the imaging device of the present invention, it is preferable that the cemented lens component has a resin lens. Use of a resin lens as any one of the cemented lens components is advantageous in reducing the thickness. In addition, when the cemented surface is an aspherical surface, manufacturing is easier than when the aspherical glass lenses are cemented together. For example, a direction in which a viscous resin material is hung on the aspherical surface of a glass lens, compressed with a mold, and solidified by cooling or ultraviolet light can be considered.

In the image pickup apparatus of the present invention, it is preferable that the cemented lens component in the first lens group satisfies the following conditional expression (7).
3.0 <ν _max −ν _min (7)
However,
ν _max is the maximum value among the Abbe numbers of each lens in the cemented lens component in the first lens group,
ν _min is the minimum value among the Abbe numbers of the lenses in the cemented lens component in the first lens group.

  By including lenses having different Abbe numbers in the cemented lens component so as not to fall below the lower limit of the conditional expression (7), it becomes more advantageous for securing the chromatic aberration correction function.

In the image pickup apparatus of the present invention, it is preferable that the cemented lens component in the first lens group satisfies the following conditional expression (8).
_{0.70 <D max / D ce <} 1.0 ··· (8)
However,
D _max is the maximum value of the thickness on the optical axis of each lens in the cemented lens component in the first lens group,
D _ce is the thickness of the cemented lens component in the first lens group on the optical axis.

  By making sure that the lower limit of conditional expression (8) is not exceeded, only one lens having a large thickness in the cemented lens component can be provided, which is more advantageous for downsizing the first lens group. By avoiding exceeding the upper limit of conditional expression (8), it becomes easy to ensure the correction function of the on-axis aberration due to the cemented lens component.

  The imaging apparatus of the present invention preferably includes a processing circuit that converts a signal formed on the imaging surface and including distortion of the zoom lens into a signal in which the distortion is corrected.

  Although distortion and astigmatism tend to be in a trade-off relationship, the distortion of the zoom lens itself can be allowed by having the processing circuit described above. This is advantageous for reducing astigmatism and reducing the size of the zoom lens.

It is more preferable that the above-described configurations and conditional expressions satisfy a plurality at the same time.
Moreover, it is more preferable to perform the following for each conditional expression.

  For conditional expression (1), it is more preferable to set the lower limit to 7.0, more preferably 9.0. More preferably, the upper limit value is 18.0, more preferably 12.0.

For conditional expression (2), it is more preferable to set the lower limit to 32.0, and more preferably 36.0. An upper limit of 80.0 may be provided.
By not exceeding the upper limit value, the refractive index of the cemented lens can be easily maintained, and the monochromatic aberration can be easily corrected. Further, the upper limit value is more preferably 70.0, and further preferably 60.0.

  For conditional expression (3), it is more preferable to set the lower limit to 0.005, more preferably 0.008. More preferably, the upper limit value is 0.30, more preferably 0.28, and even more preferably 0.25.

  For conditional expression (4), it is more preferable to set the lower limit value to 1.5, more preferably 2.0. More preferably, the upper limit value is 3.8, more preferably 3.5.

  For conditional expression (5), it is more preferable to set the lower limit value to 0.7, more preferably 0.9. The upper limit value is more preferably 2.8, and even more preferably 2.6.

  For conditional expression (6), it is more preferable to set the lower limit to 4.0, more preferably 4.5. It is more preferable that the upper limit value is 8.5, more preferably 7.0.

  For conditional expression (7), it is more preferable to set the lower limit value to 3.7, further 10.0, and further 20.0. An upper limit may be provided so that it does not exceed 70.0. This is advantageous for reducing material costs.

  For conditional expression (8), it is more preferable to set the lower limit value to 0.75, and further to 0.77. The upper limit value may be 0.990, and further 0.975.

  The present invention provides an imaging device including an optical path reflection type zoom lens composed of at least five lens groups of positive, negative, positive, positive, and positive that facilitates miniaturization and optical performance while ensuring a zoom ratio and angle of view. There exists an effect that an apparatus can be provided.

Embodiments of an 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.
In the following numerical data, the reflection surface is omitted, but a plane reflection surface that reflects the inner surface is located between the two planes of the third surface and the fourth surface, and reflects the optical axis at a right angle.

  By zooming from the wide-angle end to the telephoto end of the zoom lens, the first lens group G1, the third lens group G3, and the brightness stop are fixed with respect to the imaging surface. On the other hand, by zooming from the wide-angle end to the telephoto end, the second lens group G2 moves only to the image side, and the fourth lens group G4 moves only to the object side.

  In Examples 1, 2, and 5, the fifth lens group G5 first moves to the image side, and then the moving direction is reversed between the wide-angle end and the intermediate state. In Examples 3 and 4, first, after moving to the image side, the moving direction is reversed between the intermediate state and the telephoto end. In Example 6, it moves only to the object side. In Example 7, after moving to the object side, the moving direction is reversed between the intermediate state and the telephoto end.

  Focusing is performed by moving the fifth lens unit toward the object side.

  Examples 1 to 7 of the zoom lens according to the present invention will be described below. FIGS. 1 to 7 show lens cross-sectional views of the wide-angle end (a), the intermediate focal length state (b), and the telephoto end (c) when focusing on an object point at infinity in Examples 1 to 7, respectively. 1 to 7, the first lens group is G1, the second lens group is G2, the brightness (aperture) stop is S, the third lens group is G3, the fourth lens group is G4, and the fifth lens group is G5. The parallel flat plate constituting the low-pass filter provided with the wavelength band limiting coat for limiting the infrared light is indicated by F, the parallel flat plate of the cover glass of the electronic image pickup element is indicated by C, and the image plane (imaging plane) is indicated by I. In addition, you may give the multilayer film for wavelength range limitation to the surface of the cover glass C. FIG. Further, the cover glass C may have a low-pass filter action.

  The numerical data is data in a state where the subject is focused on an object at infinity. The unit of length of each numerical value is mm, and the unit of angle is ° (degree). In any of the embodiments, focusing is performed by moving the fifth lens group G5. Further, the zoom data are values at the wide-angle end (WE), the intermediate zoom state (ST), and the telephoto end (TE).

  As shown in FIG. 1, the zoom lens of Example 1 includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a first lens group having a positive refractive power. A three-lens group G3, a brightness (aperture) stop S, a fourth lens group G4 having a positive refractive power, and a fifth lens group G5 having a positive refractive power are arranged.

  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 moves to the image side. The third lens group G3 is fixed. The fourth lens group G4 moves to the object side. The fifth lens group G5 moves to the object side after moving to the image side. The brightness stop S is fixed.

In order from the object side, the first lens group G1 includes a planoconcave negative lens having a plane facing the object side, a prism (reflecting member), a biconvex positive lens, and a convex surface facing the image side (biconvex positive lens side). And a cemented lens with a positive meniscus lens).
The second lens group G2 includes a biconcave negative lens and a cemented lens of a positive meniscus lens having a convex surface facing the image side and a biconcave negative lens.
The third lens group G3 is composed of a positive meniscus lens having a convex surface directed toward the object side.
The fourth lens group G4 includes a biconvex positive lens, a biconvex positive lens, a biconcave negative lens, and a cemented lens including a positive meniscus lens having a convex surface directed toward the object side.
The fifth lens group G5 is composed of a biconvex positive lens.

  The aspherical surface includes three surfaces of the cemented lens of the first lens group G1, both surfaces of the object side biconcave negative lens of the second lens group G2, and the object side surface of the positive meniscus lens of the third lens group G3. It is provided on nine surfaces including both the object-side biconvex positive lens of the fourth lens group G4 and the image-side surface of the biconvex positive lens of the fifth lens group G5.

  As shown in FIG. 2, the zoom lens according to the second embodiment includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a first lens group having a positive refractive power. A three-lens group G3, a brightness (aperture) stop S, a fourth lens group G4 having a positive refractive power, and a fifth lens group G5 having a positive refractive power are arranged.

  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 moves to the image side. The third lens group G3 is fixed. The fourth lens group G4 moves to the object side. The fifth lens group G5 moves to the object side after moving to the image side. The brightness stop S is fixed.

In order from the object side, the first lens group G1 includes a planoconcave negative lens having a plane facing the object side, a prism (reflecting member), a biconvex positive lens, and a convex surface facing the image side (biconvex positive lens side). And a cemented lens with a positive meniscus lens).
The second lens group G2 includes a biconcave negative lens and a cemented lens of a positive meniscus lens having a convex surface facing the image side and a biconcave negative lens.
The third lens group G3 is composed of a positive meniscus lens having a convex surface directed toward the object side.
The fourth lens group G4 includes a biconvex positive lens, a biconvex positive lens, a biconcave negative lens, and a cemented lens including a positive meniscus lens having a convex surface directed toward the object side.
The fifth lens group G5 is composed of a biconvex positive lens.

  The aspherical surface includes three surfaces of the cemented lens of the first lens group G1, both surfaces of the object side biconcave negative lens of the second lens group G2, and the object side surface of the positive meniscus lens of the third lens group G3. It is provided on nine surfaces including both the object-side biconvex positive lens of the fourth lens group G4 and the image-side surface of the biconvex positive lens of the fifth lens group G5.

  As shown in FIG. 3, the zoom lens of Example 3 includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a first lens group having a positive refractive power. A three-lens group G3, a brightness (aperture) stop S, a fourth lens group G4 having a positive refractive power, and a fifth lens group G5 having a positive refractive power are arranged.

  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 moves to the image side. The third lens group G3 is fixed. The fourth lens group G4 moves to the object side. The fifth lens group G5 moves to the object side after moving to the image side. The brightness stop S is fixed.

In order from the object side, the first lens group G1 includes a negative meniscus lens having a convex surface directed toward the object side, a prism (reflecting member), a biconvex positive lens, and a convex surface directed toward the image side (to the biconvex positive lens side). And a cemented lens with a positive meniscus lens (with a concave surface).
The second lens group G2 includes a biconcave negative lens and a cemented lens made up of a biconvex positive lens and a biconcave negative lens.
The third lens group G3 is composed of a positive meniscus lens having a convex surface directed toward the object side.
The fourth lens group G4 includes a biconvex positive lens, a cemented lens of a biconvex positive lens and a negative meniscus lens having a convex surface facing the image side, and a cemented lens of a biconvex positive lens and a biconcave negative lens. Become.
The fifth lens group G5 is composed of a positive meniscus lens having a convex surface directed toward the image side.

  The aspherical surface includes three surfaces of the cemented lens of the first lens group G1, both surfaces of the object side biconcave negative lens of the second lens group G2, and both surfaces of the object side biconvex positive lens of the fourth lens group G4. Are provided on the seven surfaces.

  As shown in FIG. 4, the zoom lens of Example 4 includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a first lens group having a positive refractive power. A three-lens group G3, a brightness (aperture) stop S, a fourth lens group G4 having a positive refractive power, and a fifth lens group G5 having a positive refractive power are arranged.

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 moves to the image side. The third lens group G3 is fixed. The fourth lens group G4 moves to the object side. The fifth lens group G5 moves to the object side after moving to the image side. The brightness stop S is fixed.
The focusing operation from the long distance object point to the short distance object point is performed by moving the fifth lens group to the object side.

In order from the object side, the first lens group G1 has a negative meniscus lens having a convex surface directed toward the object side, a prism (reflecting member), and a convex surface directed toward the object side (a concave surface directed toward the biconvex positive lens side). It consists of a cemented lens of a negative meniscus lens and a biconvex positive lens.
The second lens group G2 includes a biconcave negative lens and a cemented lens made up of a biconvex positive lens and a biconcave negative lens.
The third lens group G3 is composed of a positive meniscus lens having a convex surface directed toward the object side.
The fourth lens group G4 includes a biconvex positive lens, a cemented lens of a biconvex positive lens and a negative meniscus lens having a convex surface facing the image side, and a cemented lens of a biconvex positive lens and a biconcave negative lens. Become.
The fifth lens group G5 is composed of a positive meniscus lens having a convex surface directed toward the image side.

  The aspherical surface includes three surfaces of the cemented lens of the first lens group G1, both surfaces of the object side biconcave negative lens of the second lens group G2, and both surfaces of the object side biconvex positive lens of the fourth lens group G4. Are provided on the seven surfaces.

  As shown in FIG. 5, the zoom lens of Example 5 includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a first lens group having a positive refractive power. A three-lens group G3, a brightness (aperture) stop S, a fourth lens group G4 having a positive refractive power, and a fifth lens group G5 having a positive refractive power are arranged.

  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 moves to the image side. The third lens group G3 is fixed. The fourth lens group G4 moves to the object side. The fifth lens group G5 moves to the object side after moving to the image side. The brightness stop S is fixed.

In order from the object side, the first lens group G1 includes a planoconcave negative lens having a plane facing the object side, a prism (reflecting member), a biconvex positive lens, and a convex surface facing the image side (biconvex positive lens side). And a cemented lens with a positive meniscus lens).
The second lens group G2 includes a biconcave negative lens and a cemented lens of a positive meniscus lens having a convex surface facing the image side and a biconcave negative lens.
The third lens group G3 is composed of a positive meniscus lens having a convex surface directed toward the object side.
The fourth lens group G4 includes a biconvex positive lens, a biconvex positive lens, a biconcave negative lens, and a cemented lens including a positive meniscus lens having a convex surface directed toward the object side.
The fifth lens group G5 is composed of a biconvex positive lens.

  The aspherical surfaces are the object-side surface of the biconvex positive lens of the first lens group G1, the image-side surface of the positive meniscus lens, both surfaces of the object-side biconcave negative lens of the second lens group G2, and the third surface. 8 of the object side surface of the positive meniscus lens of the lens group G3, both surfaces of the biconvex positive lens on the object side of the fourth lens group G4, and the image side surface of the biconvex positive lens of the fifth lens group G5. It is provided on the surface.

  As shown in FIG. 6, the zoom lens of Example 6 includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a first lens group having a positive refractive power. A three-lens group G3, a brightness (aperture) stop S, a fourth lens group G4 having a positive refractive power, and a fifth lens group G5 having a positive refractive power are arranged.

  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 moves to the image side. The third lens group G3 is fixed. The fourth lens group G4 moves to the object side. The fifth lens group G5 moves to the object side. The brightness stop S is fixed.

In order from the object side, the first lens group G1 includes a plano-concave negative lens having a plane facing the object side, a prism (reflecting member), and a convex surface facing the object side (with a concave surface facing the biconvex positive lens side). And a cemented lens of a negative meniscus lens and a biconvex positive lens.
The second lens group G2 includes a biconcave negative lens and a cemented lens of a positive meniscus lens having a convex surface facing the image side and a biconcave negative lens.
The third lens group G3 is composed of a positive meniscus lens having a convex surface directed toward the object side.
The fourth lens group G4 includes a biconvex positive lens, a biconvex positive lens, a biconcave negative lens, and a cemented lens including a positive meniscus lens having a convex surface directed toward the object side.
The fifth lens group G5 is composed of a biconvex positive lens.

  The aspherical surface includes three surfaces of the cemented lens of the first lens group G1, both surfaces of the object side biconcave negative lens of the second lens group G2, and the object side surface of the positive meniscus lens of the third lens group G3. It is provided on nine surfaces including both the object-side biconvex positive lens of the fourth lens group G4 and the image-side surface of the biconvex positive lens of the fifth lens group G5.

  As shown in FIG. 7, the zoom lens according to the seventh embodiment includes, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a first lens group having a positive refractive power. A three-lens group G3, a brightness (aperture) stop S, a fourth lens group G4 having a positive refractive power, and a fifth lens group G5 having a positive refractive power are arranged.

  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 moves to the image side. The third lens group G3 is fixed. The fourth lens group G4 moves to the object side. The fifth lens group G5 moves to the image side after moving to the object side. The brightness stop S is fixed.

In order from the object side, the first lens group G1 includes a planoconcave negative lens having a plane facing the object side, a prism (reflecting member), a biconvex positive lens, and a convex surface facing the image side (biconvex positive lens side). And a cemented lens with a positive meniscus lens).
The second lens group G2 includes a negative meniscus lens having a convex surface facing the image side, and a cemented lens formed by a positive meniscus lens having a convex surface facing the image side and a biconcave negative lens.
The third lens group G3 is composed of a positive meniscus lens having a convex surface directed toward the object side.
The fourth lens group G4 includes a biconvex positive lens, a biconvex positive lens, a biconcave negative lens, and a cemented lens including a positive meniscus lens having a convex surface directed toward the object side.
The fifth lens group G5 is composed of a biconvex positive lens.

  The aspheric surfaces are the object-side surface of the biconvex positive lens of the first lens group G1, the image-side surface of the positive meniscus lens, both surfaces of the negative meniscus lens of the second lens group G2, and the third lens group G3. It is provided on eight surfaces including the object side surface of the positive meniscus lens, both surfaces of the object side biconvex positive lens of the fourth lens group G4, and the image side surface of the biconvex positive lens of the fifth lens group G5. ing.

  Below, the numerical data of each said Example are shown. In addition to the above, R is the radius of curvature of each lens surface, D is the thickness or spacing of each lens, nd is the refractive index at the d-line of each lens, νd is the Abbe number at the d-line of each lens, and K is the cone Each coefficient is shown.

Each aspheric shape is expressed by the following formula (I) using each aspheric coefficient in each embodiment.
However, the coordinate in the optical axis direction is Z, and the coordinate in the direction perpendicular to the optical axis is Y.
Z = (Y ² / r) / [1+ {1− (1 + K) · (Y / r) ² } ^1/2 ] +
A4 × Y ⁴ + A6 × Y ⁶ + A8 × Y ⁸ + A10 × Y ¹⁰ + A12 × Y ¹² (I)
However,
r is the paraxial radius of curvature,
K is the cone coefficient,
A4, A6, A8, A10 and A12 are the fourth, sixth, eighth, tenth and twelfth aspherical 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 ∞ 0.60 2.00069 25.46
2 11.783 2.14
3 ∞ 8.60 1.90366 31.31
4 ∞ 0.30
5 * 16.190 1.98 1.69350 53.21
6 * -37.290 0.50 1.73310 48.90
7 * -13.930 variable
8 * -66.882 0.70 1.83481 42.71
9 * 16.477 1.18
10 -16.288 1.12 1.92286 20.88
11 -6.825 0.70 1.88300 40.76
12 62.039 Variable
13 * 9.980 1.03 1.69895 30.13
14 18.753 0.63
15 Aperture variable
16 * 7.425 2.90 1.49700 81.54
17 * -15.128 0.15
18 7.849 3.10 1.72000 43.69
19 -6.262 0.72 1.90366 31.31
20 3.033 1.72 1.71300 53.87
21 4.734 Variable
22 13.397 1.80 1.52542 55.78
23 * -16.108 variable
24 ∞ 0.50 1.51633 64.14
25 ∞ 0.50
26 ∞ 0.50 1.51633 64.14
27 ∞ 0.39
Image plane (imaging plane) ∞

Aspheric data 5th surface
K = -0.627
A4 = -5.02983e-05, A6 = 1.92205e-06, A8 = -1.54833e-08, A10 = -1.18380e-10
6th page
K = 0.000
A4 = 1.02277e-03, A6 = -6.55842e-05, A8 = 6.21970e-07
7th page
K = -0.423
A4 = 1.04210e-04, A6 = -1.56817e-06, A8 = 1.14249e-08
8th page
K = 0.363
A4 = 3.13661e-04, A6 = -1.56364e-05, A8 = 2.88688e-08, A10 = 4.37010e-09
9th page
K = 5.202
A4 = 2.00257e-04, A6 = -2.16823e-05, A8 = 6.82067e-08
13th page
K = 0.768
A4 = -2.30762e-04, A6 = -2.49905e-06, A8 = -2.81050e-07
16th page
K = -0.113
A4 = -1.36112e-04, A6 = 6.15340e-06, A8 = -1.15090e-06, A10 = -4.48554e-09
17th page
K = 0.595
A4 = 1.90807e-04, A6 = 2.64101e-06, A8 = -1.47655e-06, A10 = -3.87357e-09
23rd page
K = -1.766
A4 = -5.17783e-05, A6 = -2.37186e-06, A8 = -6.47319e-08, A10 = 3.14974e-09

Zoom data
Wide angle Medium telephoto
Focal length 4.46 10.56 21.10
FNO. 3.50 5.03 6.00
Angle of view 2ω 88.14 37.93 19.82

D7 0.30 4.88 8.62
D12 8.62 4.04 0.30
D15 8.16 3.89 0.30
D21 2.74 7.11 9.01
D23 1.40 1.31 3.00

fb (in air) 2.95 2.86 4.55
Total length (in air) 52.65 52.65 52.65

Group focal length
f1 = 15.03 f2 = -7.42 f3 = 29.11 f4 = 13.43 f5 = 14.22

Numerical example 2
Unit mm

Surface data surface number rd nd νd
Object ∞ ∞
1 ∞ 0.60 2.00069 25.46
2 11.749 2.14
3 ∞ 8.60 1.90366 31.31
4 ∞ 0.30
5 * 15.979 1.98 1.69350 53.21
6 * -38.441 0.50 1.73310 48.90
7 * -14.092 variable
8 * -84.227 0.70 1.83481 42.71
9 * 15.708 1.21
10 -15.336 1.13 1.92286 20.88
11 -6.709 0.70 1.88300 40.76
12 82.508 Variable
13 * 10.343 0.61 1.69895 30.13
14 20.082 0.63
15 Aperture variable
16 * 7.474 2.80 1.49700 81.54
17 * -15.044 0.15
18 7.798 3.00 1.72151 29.23
19 -6.409 0.72 1.90200 25.10
20 3.021 1.76 1.72000 43.69
21 4.638 Variable
22 13.432 1.80 1.51633 64.14
23 * -15.103 variable
24 ∞ 0.50 1.51633 64.14
25 ∞ 0.50
26 ∞ 0.50 1.51633 64.14
27 ∞ 0.39
Image plane (imaging plane) ∞

Aspheric data 5th surface
K = -0.608
A4 = -4.94266e-05, A6 = 1.73911e-06, A8 = -1.12726e-08, A10 = -2.33513e-10
6th page
K = 0.000
A4 = 1.02277e-03, A6 = -6.55842e-05, A8 = 6.21970e-07
7th page
K = -0.425
A4 = 1.04884e-04, A6 = -1.65736e-06, A8 = 9.83398e-09
8th page
K = -20.230
A4 = 3.16800e-04, A6 = -1.54192e-05, A8 = 1.34475e-07, A10 = 1.91746e-09
9th page
k = 4.967
A4 = 1.96841e-04, A6 = -2.21161e-05, A8 = 2.39775e-07
13th page
K = 0.784
A4 = -2.14610e-04, A6 = -5.31448e-06, A8 = 2.10979e-07
16th page
K = -0.091
A4 = -1.28489e-04, A6 = 6.48184e-06, A8 = -1.29329e-06, A10 = 7.59984e-09
17th page
K = 0.545
A4 = 1.93085e-04, A6 = 1.89803e-06, A8 = -1.42403e-06, A10 = 8.73513e-10
23rd page
K = -2.390
A4 = -7.30572e-05, A6 = -4.05031e-06, A8 = 3.78842e-08, A10 = 1.21263e-09


Zoom data
Wide angle Medium Telephoto focal length 4.46 10.56 21.10
FNO. 3.50 5.06 6.00
Angle of view 2ω 88.14 38.15 19.91

D7 0.31 4.84 8.66
D12 8.65 4.12 0.30
D15 8.24 3.88 0.30
D21 2.86 7.43 9.30
D23 1.50 1.29 3.00
D27 0.39 0.39 0.39

fb (in air) 3.05 2.84 4.55
Total length (in air) 52.44 52.44 52.44

Group focal length
f1 = 15.06 f2 = -7.45 f3 = 29.75 f4 = 13.67 f5 = 14.07

Numerical Example 3
Unit mm

Surface data surface number rd nd νd
Object ∞ ∞
1 21.220 0.60 2.00069 25.46
2 6.891 3.46
3 ∞ 8.00 1.84666 23.78
4 ∞ 0.20
5 * 26.019 3.30 1.67790 55.34
6 * -10.594 0.30 1.68893 31.07
7 * -10.51 0.10
8 * -12.421 0.48 1.80610 40.92
9 * 32.583 0.33
10 47.356 1.30 1.92286 18.90
11 -16.747 0.49 1.88300 40.76
12 27.921 Variable
13 33.554 0.81 1.92286 18.90
14 37.111 0.50
15 Aperture variable
16 * 7.833 3.10 1.52542 55.78
17 * -16.853 0.10
18 23.089 2.90 1.49700 81.54
19 -6.490 0.50 1.67003 47.23
20 -10.318 0.30
21 8.160 2.00 1.49700 81.54
22 -25.683 0.48 2.00069 25.46
23 4.429 Variable
24 -39.200 1.80 1.71736 29.52
25 -9.760 Variable
26 ∞ 0.50 1.51633 64.14
27 ∞ 0.50
28 ∞ 0.50 1.51633 64.14
29 ∞ 0.39
Image plane (imaging plane) ∞

Aspheric data 5th surface
K = 0.000
A4 = -4.54344e-05, A6 = 1.41004e-06, A8 = -1.83204e-08
6th page
K = 0.000
A4 = -3.70991e-04, A6 = 1.16542e-05, A8 = -1.14308e-07
7th page
K = 0.326
A4 = 1.04663e-04, A6 = 1.68313e-06, A8 = -7.20268e-09, A10 = 6.36988e-11
8th page
K = 0.000
A4 = -1.79165e-04, A6 = 9.28415e-06
9th page
K = 0.000
A4 = -4.05241e-04, A6 = 1.10797e-05
16th page
K = 0.000
A4 = -3.38399e-04, A6 = -6.20033e-06
17th page
K = 0.000
A4 = 4.30588e-04, A6 = -6.81288e-06

Zoom data
Wide angle Medium Telephoto focal length 4.46 10.56 21.10
FNO. 3.50 4.63 7.20
Angle of view 2ω 87.44 37.96 20.60

D7 0.92 6.97 8.15
D12 7.59 1.54 0.36
D15 9.07 6.44 0.30
D23 2.70 6.12 12.26
D25 2.89 2.10 2.10

fb (in air) 4.43 3.65 3.65
Total length (in air) 56.16 56.16 56.16

Group focal length
f1 = 14.33 f2 = -9.78 f3 = 341.95 f4 = 10.58 f5 = 17.66

Numerical Example 4
Unit mm

Surface data surface number rd nd νd
Object ∞ ∞
1 20.013 0.60 2.00069 25.46
2 6.703 3.55
3 ∞ 8.00 1.84666 23.78
4 ∞ 0.20
5 * 25.288 0.30 1.68893 31.16
6 * 22.124 3.30 1.67790 55.34
7 * -10.446 0.10
8 * -13.046 0.48 1.80610 40.92
9 * 22.399 0.32
10 26.655 1.35 1.92286 18.90
11 -20.501 0.49 1.88300 40.76
12 22.426 Variable
13 41.649 0.81 1.92286 18.90
14 43.941 0.50
15 Aperture variable
16 * 7.879 3.10 1.52542 55.78
17 * -16.002 0.10
18 22.361 2.90 1.49700 81.54
19 -6.680 0.50 1.67003 47.23
20 -10.628 0.30
21 8.699 2.00 1.49700 81.54
22 -24.518 0.48 2.00069 25.46
23 4.577 Variable
24 -38.905 1.80 1.71736 29.52
25 -9.782 Variable
26 ∞ 0.50 1.51633 64.14
27 ∞ 0.50
28 ∞ 0.50 1.51633 64.14
29 ∞ 0.39
Image plane (imaging plane) ∞

Aspheric data 5th surface
k = 0.000
A4 = -5.74246e-05, A6 = 1.26768e-06, A8 = -1.71241e-08
6th page
k = 0.000
A4 = 3.22248e-04, A6 = -6.97734e-06, A8 = 8.82762e-08
7th page
k = 0.335
A4 = 1.00339e-04, A6 = 1.64734e-06, A8 = -8.30208e-09, A10 = 8.52536e-11
8th page
k = 0.000
A4 = -2.52313e-04, A6 = 1.02095e-05
9th page
k = 0.000
A4 = -4.72618e-04, A6 = 1.12731e-05
16th page
k = 0.000
A4 = -3.41223e-04, A6 = -6.36227e-06
17th page
k = 0.000
A4 = 4.29084e-04, A6 = -7.00532e-06

Zoom data

Wide angle Medium Telephoto focal length 4.46 11.08 21.10
FNO. 3.50 4.72 7.20
Angle of view 2ω 88.75 36.65 20.61

D7 0.92 7.13 8.21
D12 7.66 1.46 0.38
D15 8.71 5.97 0.30
D23 2.70 6.39 12.06
D25 3.05 2.10 2.10

fb (in air) 4.60 3.65 3.65
Total length (in air) 56.16 56.16 56.16

Group focal length
f1 = 13.89 f2 = -9.66 f3 = 740.30 f4 = 10.50 f5 = 17.76

Numerical Example 5
Unit mm

Surface data surface number rd nd νd
Object ∞ ∞
1 ∞ 0.60 2.00069 25.46
2 11.701 2.22
3 ∞ 8.60 1.90366 31.31
4 ∞ 0.30
5 * 15.493 2.57 1.69350 53.21
6 -14.144 0.10 1.63387 23.38
7 * -13.730 variable
8 * -34.503 0.69 1.80610 40.92
9 * 38.923 0.80
10 -26.016 1.12 1.92286 18.90
11 -8.308 0.70 1.88300 40.76
12 15.731 Variable
13 * 7.394 0.80 1.68893 31.07
14 11.271 0.63
15 Aperture variable
16 * 7.950 2.80 1.49700 81.54
17 * -15.612 0.15
18 7.294 3.06 1.80810 22.76
19 -7.638 0.60 1.92286 18.90
20 3.228 1.01 1.76182 26.52
21 4.112 Variable
22 19.926 1.80 1.52542 55.78
23 * -10.416 variable
24 ∞ 0.50 1.58313 59.38
25 ∞ 0.50
26 ∞ 0.50 1.51633 64.14
27 ∞ 0.39
Image plane (imaging plane) ∞

Aspheric data 5th surface
k = -0.490
A4 = -4.66155e-05, A6 = 3.67375e-07, A8 = -1.71879e-09, A10-4.27952e-11
7th page
k = -0.137
A4 = 8.98779e-05, A6 = 5.54923e-07, A8 = -6.75690e-09
8th page
k = 25.911
A4 = 3.43805e-04, A6 = 4.34601e-06, A8 = -7.86960e-07, A10 = 1.25217e-08
9th page
k = 13.342
A4 = 1.67874e-04, A6 = 1.10374e-07, A8 = -6.54282e-07
13th page
k = 0.274
A4 = -3.10230e-04, A6 = -1.02527e-05, A8 = -7.47098e-08
16th page
k = -0.009
A4 = -1.15895e-04, A6 = 2.67427e-05, A8 = -1.59174e-06, A10 = 3.60365e-08
17th page
k = -1.671
A4 = 2.95243e-04, A6 = 2.43310e-05, A8 = -1.30454e-06, A10 = 1.93551e-08
23rd page
k = -1.478
A4 = -1.00341e-04, A6 = -2.84719e-06, A8 = -7.58454e-08, A10 = 4.06994e-09

Zoom data
Wide angle Medium telephoto focal length 4.46 10.56 21.09
FNO. 3.49 4.76 5.92
Angle of view 2ω 84.72 36.65 19.04

D7 0.30 5.14 8.66
D12 8.66 3.82 0.30
D15 7.99 3.89 0.30
D21 4.05 7.59 9.79
D23 1.05 1.61 3.00

fb (in air) 2.60 3.15 4.54
Total length (in air) 52.14 52.14 52.14

Group focal length
f1 = 14.72 f2 = -7.20 f3 = 28.79 f4 = 12.81 f5 = 13.29

Numerical Example 6
Unit mm

Surface data surface number rd nd νd
Object ∞ ∞
1 ∞ 0.60 2.00069 25.46
2 11.696 2.31
3 ∞ 8.60 1.90366 31.31
4 ∞ 0.30
5 * 16.276 0.30 1.63387 23.38
6 * 16.000 2.70 1.69350 53.21
7 * -13.496 variable
8 * -38.419 0.69 1.80610 40.88
9 * 26.529 0.99
10 -23.738 1.22 1.92286 20.88
11 -7.050 0.70 1.88300 40.76
12 19.462 Variable
13 * 7.239 0.62 1.72151 29.23
14 10.757 0.63
15 Aperture variable
16 * 7.700 2.93 1.49700 81.54
17 * -13.416 0.15
18 8.171 3.15 1.72151 29.23
19 -6.397 0.56 1.90 200 25.10
20 3.184 2.37 1.74320 49.34
21 4.804 Variable
22 17.517 1.80 1.52542 55.78
23 * -14.058 variable
24 ∞ 0.50 1.58313 59.38
25 ∞ 0.50
26 ∞ 0.50 1.51633 64.14
27 ∞ 0.38
Image plane (imaging plane) ∞

Aspheric data 5th surface
k = -0.165
A4 = -3.41278e-05, A6 = -7.12362e-07, A8 = 1.99337e-08, A10 = 1.03160e-10
6th page
k = -0.643
A4 = -1.84362e-05, A6 = 1.08387e-06, A8 = 4.47981e-08
7th page
k = -0.207
A4 = 9.44493e-05, A6 = -4.15823e-07, A8 = 2.31884e-08
8th page
k = 11.748
A4 = 3.05441e-04, A6 = 1.09371e-05, A8 = -3.50844e-07, A10 = 6.80876e-09
9th page
k = 7.790
A4 = 2.39247e-04, A6 = 2.84762e-06, A8 = 1.11011e-06
13th page
k = 0.338
A4 = -3.13193e-04, A6 = -1.17075e-05, A8 = 9.63383e-07
16th page
k = -0.163
A4 = -1.48892e-04, A6 = 8.53089e-07, A8 = -1.06945e-06, A10 = 1.18080e-07
17th page
k = -0.137
A4 = 2.25121e-04, A6 = 1.46390e-05, A8 = -3.87640e-06, A10 = 2.40615e-07
23rd page
k = -3.661
A4 = -3.98884e-05, A6 = -8.86578e-06, A8 = -1.20008e-07, A10 = 1.28262e-08

Zoom data
Wide angle Medium telephoto focal length 4.41 10.56 21.10
FNO. 3.50 4.63 6.50
Angle of view 2ω 88.56 37.82 19.86

D7 0.30 5.49 8.42
D12 8.41 3.22 0.30
D15 8.06 4.45 0.30
D21 3.13 5.64 8.28
D23 0.39 1.50 3.00

fb (in air) 1.94 3.03 4.52
Total length (in air) 52.44 52.44 52.44

Group focal length
f1 = 14.82 f2 = -7.21 f3 = 28.57 f4 = 11.95 f5 = 15.14

Numerical Example 7
Unit mm

Surface data surface number rd nd νd
Object ∞ ∞
1 ∞ 0.60 2.00069 25.46
2 11.596 2.25
3 ∞ 8.60 1.90366 31.32
4 ∞ 0.30
5 * 15.211 2.75 1.72476 55.03
6 -14.460 0.10 1.63387 23.38
7 * -14.373 variable
8 * -16.901 0.69 1.82283 44.78
9 * -74.705 0.54
10 -32.230 1.25 1.89562 19.69
11 -8.253 0.70 1.88300 40.76
12 12.203 Variable
13 * 8.479 1.07 1.68893 31.07
14 13.687 0.63
15 Aperture variable
16 * 7.376 2.93 1.49700 81.54
17 * -15.594 0.15
18 7.825 3.15 1.71038 25.81
19 -6.193 0.72 1.90823 24.24
20 3.019 1.58 1.69815 56.61
21 4.890 Variable
22 16.904 1.80 1.52542 55.78
23 * -12.218 variable
24 ∞ 0.50 1.58313 59.38
25 ∞ 0.50
26 ∞ 0.50 1.51633 64.14
27 ∞ 0.39
Image plane (imaging plane) ∞

Aspheric data 5th surface
k = -0.562
A4 = -4.82045e-05, A6 = -7.36616e-07, A8 = 2.02890e-08, A10 = -5.91897e-11
7th page
k = -0.150
A4 = 9.14702e-05, A6 = -8.01280e-07, A8 = 1.88756e-08
8th page
k = -4.283
A4 = 3.34717e-04, A6 = 1.19292e-05, A8 = -6.90619e-07, A10 = 9.15023e-09
9th page
k = -58.177
A4 = 1.92406e-04, A6 = 1.26860e-05, A8 = -3.55670e-07
13th page
k = 0.595
A4 = -2.74949e-04, A6 = -1.68473e-05, A8 = 1.74097e-06
16th page
k = -0.115
A4 = -1.38084e-04, A6 = -7.32845e-06, A8 = 1.38938e-07, A10 = -7.48094e-08
17th page
k = 1.120
A4 = 1.73997e-04, A6 = -6.49915e-06, A8 = -1.24516e-06, A10 = -2.44462e-08
23rd page
k = -0.327
A4 = -2.67394e-04, A6 = 7.19598e-06, A8 = -3.63742e-07, A10 = 8.20118e-09

Zoom data
Wide angle Medium telephoto focal length 4.47 13.50 27.05
FNO. 3.50 5.23 6.30
Angle of view 2ω 88.68 31.78 16.38

D7 0.30 6.11 9.56
D12 9.56 3.75 0.30
D15 8.44 2.25 0.30
D21 2.50 6.70 10.15
D23 2.50 4.50 3.00

fb (in air) 4.04 6.02 4.54
Total length (in air) 54.65 54.65 54.65

Group focal length
f1 = 13.82 f2 = -6.91 f3 = 29.85 f4 = 14.24 f5 = 13.79

  Examples 8 to 14 are examples in which the zoom lenses of Examples 1 to 7 are used, respectively, and used in an imaging apparatus that electrically corrects distortion, and the shape of the effective imaging region changes during zooming. Therefore, it is different from the embodiment corresponding to the image height and the angle of view in the zoom state.

  In Examples 8 to 14, images are recorded and displayed after electrically correcting barrel distortion generated on the wide angle side.

  In the zoom lens of this embodiment, barrel distortion occurs at the wide-angle end on the rectangular photoelectric conversion surface. On the other hand, the occurrence of distortion is suppressed near the intermediate focal length state and at the telephoto end.

  In order to electrically correct the distortion, the effective imaging area has a barrel shape at the wide angle end and a rectangular shape at the intermediate focal length state or the telephoto end. Then, the effective imaging area set in advance is image-converted by image processing and converted into rectangular image information with reduced distortion.

The maximum image height IH _w at the wide-angle end is made smaller than the maximum image height IH _{s at} the intermediate focal length state and the maximum image height IH _t at the telephoto end.
In Examples 8 to 14, the length in the short side direction of the photoelectric conversion surface at the wide angle end is the same as the length in the short side direction of the effective imaging region, and the distortion after image processing is about −3%. The effective imaging area is determined so as to remain. Of course, an image obtained by converting a smaller barrel-shaped area into a rectangular shape as an effective imaging area may be recorded and reproduced.

The zoom lens of the eighth embodiment is the same as the zoom lens of the first embodiment.
The zoom lens of the ninth embodiment is the same as the zoom lens of the second embodiment.
The zoom lens of Example 10 is the same as the zoom lens of Example 3.
The zoom lens of Example 11 is the same as the zoom lens of Example 4.
The zoom lens of Example 12 is the same as the zoom lens of Example 5.
The zoom lens of the thirteenth embodiment is the same as the zoom lens of the sixth embodiment.
The zoom lens of Example 14 is the same as the zoom lens of Example 7.

Data on the image height and the total angle of view in Example 8 are shown below.
Various data
Wide-angle intermediate telephoto height 3.61 3.8 3.8
Angle of view 2ω 85.0 37.93 19.82

Data on the image height and the total angle of view in Example 9 are shown below.
Various data
Wide-angle intermediate telephoto height 3.61 3.8 3.8
Angle of view 2ω 85.1 38.15 19.91

Data of image height and full angle of view in Example 10 are shown below.
Various data
Wide angle Medium Telephoto height 3.69 3.84 3.84
Angle of view 2ω 85.8 37.96 20.60

Data on the image height and the total angle of view in Example 11 are shown below.
Various data
Wide angle Medium Telephoto height 3.64 3.84 3.84
Angle of view 2ω 86.3 36.65 20.61

Data of the image height and the total angle of view in Example 12 are shown below.
Various data
Wide angle Medium Telephoto height 3.43 3.6 3.6
Angle of view 2ω 81.7 36.65 19.04

Data of image height and full angle of view in Example 13 are shown below.
Various data
Wide angle Medium Telephoto height 3.67 3.84 3.84
Angle of view 2ω 86.1 37.82 19.86

Data of the image height and the total angle of view in Example 14 are shown below.
Various data
Wide angle Medium Telephoto height 3.65 3.84 3.84
Angle of view 2ω 85.8 31.78 16.38

Aberration diagrams at the time of focusing on an object point at infinity in Examples 1 to 7 are shown in FIGS. In these aberration diagrams, (a) is the wide angle end, (b) is the intermediate focal length state, (c) is the spherical aberration (SA), astigmatism (AS), distortion (DT), and magnification at the telephoto end. Chromatic aberration (CC) is shown. In each figure, “ω” indicates a half angle of view.

Next, the values of conditional expressions (1) to (8) in each example will be listed.

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7
(1) (| r ₁ | + | r ₂ |) / d ₁ 12.12 12.14 10.15 9.93 10.96 9.92 10.39
(2) ν _ave 51.05 51.05 43.21 43.25 38.30 38.30 39.21
(3) f _2g / f ₃ g 0.25 0.25 0.03 0.01 0.25 0.25 0.23
(4) f _1g / f _w 3.37 3.38 3.21 3.11 3.30 3.36 3.10
(5) D / f _t 2.35 2.35 2.57 2.57 2.34 2.33 1.91
(6) f _t / f _w 4.73 4.73 4.73 4.73 4.72 4.78 6.06
(7) ν _max -ν _min 4.31 4.31 24.27 24.18 29.83 29.83 31.65
_{(8) D max / D ce} 0.799 0.798 0.917 0.917 0.963 0.900 0.965

(Correction of distortion)
By the way, when the zoom lens of the present invention is used, image distortion is digitally corrected electrically. The basic concept for digitally correcting image distortion will be described below.

  For example, as shown in FIG. 15, the magnification on the circumference (image height) of the radius R inscribed in the long side of the effective imaging surface around the intersection of the optical axis and the imaging surface is fixed, and this circumference is The standard for correction. Then, correction is performed by moving each point on the circumference (image height) of any other radius r (ω) in a substantially radial direction and concentrically so as to have the radius r ′ (ω). To do.

For example, in FIG. 15, a point P ₁ on the circumference of an arbitrary radius r ₁ (ω) located inside the circle of radius R is a radius r ₁ ′ (ω) circle to be corrected toward the center of the circle. Move to point P ₂ on the circumference. A point Q ₁ on the circumference of an arbitrary radius r ₂ (ω) located outside the circle of radius R is a radius r ₂ ′ (ω) circumference to be corrected in a direction away from the center of the circle. It is moved to the point Q ₂ of the above.

Here, r ′ (ω) can be expressed as follows.
r ′ (ω) = α · f · tan ω
However,
ω is the half angle of view of the subject,
f is the focal length of the imaging optical system (in the present invention, the zoom lens),
α is 0 or more and 1 or less.

Here, if the ideal image height corresponding to the circle (image height) of radius R is Y,
α = R / Y = R / (f · tan ω)
It becomes.

  The optical system is ideally rotationally symmetric with respect to the optical axis, that is, distortion is also generated rotationally symmetric with respect to the optical axis. Therefore, as described above, when the optically generated distortion aberration is electrically corrected, the radius inscribed in the long side of the effective imaging surface around the intersection of the optical axis and the imaging surface on the reproduced image. The magnification on the circumference of the circle of R (image height) is fixed, and the other points on the circumference of the circle (image height) of radius r (ω) are moved in a substantially radial direction to obtain a radius r ′ ( If correction can be performed by moving the concentric circles so that ω), it is considered advantageous in terms of data amount and calculation amount.

  However, the optical image is no longer a continuous amount (due to sampling) when captured by the electronic image sensor. Therefore, strictly speaking, the circle with the radius R drawn on the optical image is not an accurate circle unless the pixels on the electronic image sensor are arranged radially.

  That is, in the shape correction of the image data represented for each discrete coordinate point, there is no circle that can fix the magnification. Therefore, it is preferable to use a method of determining the coordinates (Xi ′, Yj ′) of the movement destination for each pixel (Xi, Yj). When two or more points (Xi, Yj) have moved to the coordinates (Xi ′, Yj ′), the average value of the values possessed by each pixel is taken. If there is no moving point, interpolation may be performed using the values of the coordinates (Xi ′, Yj ′) of some surrounding pixels.

  Such a method is particularly distorted with respect to the optical axis due to manufacturing errors of an optical system or an electronic image pickup device in an electronic image pickup apparatus having a zoom lens, and the circle of the radius R drawn on the optical image is asymmetric. It is effective for correction when Further, it is effective for correction when a geometric distortion or the like occurs when a signal is reproduced as an image in an image sensor or various output devices.

  In the electronic imaging apparatus of the present invention, in order to calculate the correction amount r ′ (ω) −r (ω), r (ω), that is, the relationship between the half field angle and the image height, or the real image height r and the ideal image height. The relationship between r ′ / α may be recorded on a recording medium built in the electronic imaging apparatus.

Note that the radius R should satisfy the following conditional expression in order to prevent the image after distortion correction from having an extremely short amount of light at both ends in the short side direction.
0 ≦ R ≦ 0.6Ls
However, Ls is the length of the short side of the effective imaging surface.

The radius R preferably satisfies the following conditional expression.
0.3Ls≤R≤0.6Ls
Furthermore, it is most advantageous to make the radius R coincide with the radius of the inscribed circle in the short side direction of the substantially effective imaging surface. In the case of correction in which the magnification is fixed in the vicinity of the radius R = 0, that is, in the vicinity of the axis, there is a slight disadvantage in terms of image quality, but the effect of reducing the size is ensured even if the angle of view is widened. it can.

The focal length section that needs to be corrected is divided into several focal zones. And approximately near the telephoto end in the divided focal zone,
r ′ (ω) = α · f · tan ω
You may correct | amend with the same correction amount as the case where the correction result which satisfies is obtained.

  However, in that case, some barrel distortion remains at the wide-angle end in the divided focal zone. Further, if the number of divided zones is increased, it becomes unnecessary to store extraneous data necessary for correction in the recording medium, which is not preferable. Therefore, one or several coefficients related to each focal length in the divided focal zone are calculated in advance. This coefficient may be determined on the basis of simulation or actual measurement.

And near the telephoto end in the divided zone,
r ′ (ω) = α · f · tan ω
A correction amount when a correction result satisfying the above is obtained may be calculated, and the final correction amount may be obtained by uniformly multiplying the correction amount by a coefficient for each focal length.

By the way, if there is no distortion in the image obtained by imaging an object at infinity,
f = y / tan ω
Is established.
Where y is the height of the image point from the optical axis (image height), f is the focal length of the imaging system (in the present invention, the zoom lens), and ω is the image point connected from the center on the imaging surface to the y position. It is an angle (subject half field angle) with respect to the optical axis in the corresponding object direction.

If the imaging system has barrel distortion,
f> y / tan ω
It becomes. That is, if the focal length f of the imaging system and the image height y are constant, the value of ω increases.

(Digital camera)
The zoom lens of the present invention as described above forms an object image, and the image can be received by an electronic image sensor such as a CCD. The embodiment is illustrated below.

  FIGS. 16 to 18 are conceptual diagrams of structures in which the zoom lens according to the present invention is incorporated in the photographing optical system 141 of the digital camera. 16 is a front perspective view showing the external appearance of the digital camera 140, FIG. 17 is a rear perspective view thereof, and FIG. 18 is a cross-sectional view showing the configuration of the digital camera 140. In this example, the digital camera 140 includes a photographing optical system 141 having a photographing optical path 142, a finder optical system 143 having a finder optical path 144, a shutter 145, a flash 146, a liquid crystal display monitor 147, and the like. When the shutter 145 disposed in the position is pressed, photographing is performed through the photographing optical system 141, for example, the optical path bending zoom lens according to the first embodiment in conjunction therewith. An object image formed by the photographing optical system 141 is formed on the imaging surface of the CCD 149 through a near-infrared cut filter and an optical low-pass filter F. The object image received by the CCD 149 is displayed as an electronic image on a liquid crystal display monitor 147 provided on the back of the camera via the processing means 151. Further, the processing means 151 is connected to a recording means 152 so that a photographed electronic image can be recorded. The recording unit 152 may be provided separately from the processing unit 151, or may be configured to perform recording / writing electronically using a flexible disk, a memory card, an MO, or the like.

  Further, a finder objective optical system 153 is disposed on the finder optical path 144. The object image formed by the finder objective optical system 153 is formed on the field frame 157 of the Porro prism 155 that is an image erecting member. Behind this polyprism 155, an eyepiece optical system 159 for guiding an erect image to the observer eyeball E is disposed. Cover members 150 are disposed on the incident side of the photographing optical system 141 and the finder objective optical system 153 and on the exit side of the eyepiece optical system 159, respectively.

  The digital camera 140 configured in this manner is a zoom lens having a high zoom ratio and a high optical performance of the photographing optical system 141, which is about 5 times. Can be realized.

  In addition, in the example of FIG. 18, although a parallel plane board is arrange | positioned as the cover member 150, you may omit.

(Internal circuit configuration)
FIG. 19 is a block diagram showing the internal circuitry of the main part of the digital camera 140. In the following description, the processing means includes, for example, the CDS / ADC unit 124, the temporary storage memory 117, the image processing unit 118, and the like, and the storage means includes, for example, the storage medium unit 119.

  As shown in FIG. 19, the digital camera 140 is connected to the operation unit 112, the control unit 113 connected to the operation unit 112, and the control signal output port of the control unit 113 via buses 114 and 115. An imaging drive circuit 116, a temporary storage memory 117, an image processing unit 118, a storage medium unit 119, a display unit 120, and a setting information storage memory unit 121 are provided.

  The temporary storage memory 117, the image processing unit 118, the storage medium unit 119, the display unit 120, and the setting information storage memory unit 121 are configured so that data can be input or output with each other via the bus 122. In addition, a CCD 149 and a CDS / ADC unit 124 are connected to the imaging drive circuit 116.

  The operation unit 112 includes various input buttons and switches, and is a circuit that notifies the control unit of event information input from the outside (camera user) via these input buttons and switches.

  The control unit 113 is a central processing unit composed of, for example, a CPU and the like. The control unit 113 includes a program memory (not shown) and is input from the camera user via the operation unit 112 according to a program stored in the program memory. This is a circuit that controls the entire digital camera 140 in response to an instruction command.

  The CCD 149 receives an object image formed through the photographing optical system 141 according to the present invention. The CCD 149 is an image pickup element that is driven and controlled by the image pickup drive circuit 116, converts the light amount of each pixel of the object image into an electrical signal, and outputs the electric signal to the CDS / ADC unit 124.

  The CDS / ADC unit 124 amplifies the electric signal input from the CCD 149 and performs analog / digital conversion, and temporarily stores the raw video data (Bayer data, hereinafter referred to as RAW data) that has just been subjected to the amplification and digital conversion. This is a circuit for outputting to the storage memory 117.

  The temporary storage memory 117 is a buffer made of, for example, SDRAM or the like, and is a memory device that temporarily stores the RAW data output from the CDS / ADC unit 124. The image processing unit 118 reads out the RAW data stored in the temporary storage memory 117 or the RAW data stored in the storage medium unit 119, and performs various corrections including distortion correction based on the image quality parameter designated from the control unit 113. It is a circuit that performs image processing electrically.

  The recording medium unit 119 detachably mounts a card-type or stick-type recording medium made of, for example, a flash memory, and RAW data transferred from the temporary storage memory 117 to the card-type or stick-type flash memory. This is a control circuit of an apparatus for recording and holding image data processed by the image processing unit 118.

  The display unit 120 includes a liquid crystal display monitor, and is a circuit that displays an image, an operation menu, and the like on the liquid crystal display monitor. The setting information storage memory unit 121 stores a ROM unit in which various image quality parameters are stored in advance, and an image quality parameter selected by an input operation of the operation unit 112 among the image quality parameters read from the ROM unit. RAM section is provided. The setting information storage memory unit 121 is a circuit that controls input and output to these memories.

  In the digital camera 140 configured in this way, the imaging optical system 141 has a sufficiently wide angle range and a compact configuration according to the present invention, and the imaging performance is extremely stable at a high zoom ratio and in a full zoom ratio range. Therefore, high performance, downsizing, and wide angle of view can be realized. In addition, fast focusing operation on the wide-angle side and the telephoto side is possible.

  As described above, the image pickup apparatus according to the present invention is useful for ensuring optical performance and reducing the size while having a zoom ratio and a field angle.

FIG. 2 is a lens cross-sectional view at the wide-angle end (a), the intermediate state (b), and the telephoto end (c) when focusing on an object point at infinity according to the first exemplary embodiment of the zoom lens of the present invention. It is the same figure as FIG. 1 of Example 2 of the zoom lens of this invention. It is the same figure as FIG. 1 of Example 3 of the zoom lens of this invention. It is the same figure as FIG. 1 of Example 4 of the zoom lens of this invention. It is the same figure as FIG. 1 of Example 5 of the zoom lens of this invention. It is the same figure as FIG. 1 of Example 6 of the zoom lens of this invention. It is the same figure as FIG. 1 of Example 7 of the zoom lens of this invention. FIG. 6 is an aberration diagram for Example 1 upon focusing on an object point at infinity. FIG. 6 is an aberration diagram for Example 2 upon focusing on an object point at infinity. FIG. 10 is an aberration diagram for Example 3 upon focusing on an object point at infinity. FIG. 10 is an aberration diagram for Example 4 upon focusing on an object point at infinity. FIG. 10 is an aberration diagram for Example 5 upon focusing on an object point at infinity. FIG. 10 is an aberration diagram for Example 6 upon focusing on an object point at infinity. FIG. 10 is an aberration diagram for Example 7 upon focusing on an object point at infinity. It is a figure explaining correction | amendment of a distortion aberration. It is a front perspective view which shows the external appearance of the digital camera incorporating the optical path bending zoom lens by this invention. It is a rear perspective view of the digital camera. It is sectional drawing of the said digital camera. It is a block diagram of the internal circuit of the main part of the digital camera.

Explanation of symbols

G1 ... 1st lens group G2 ... 2nd lens group G3 ... 3rd lens group G4 ... 4th lens group G5 ... 5th lens group S ... Aperture stop F ... Low pass filter C ... Cover glass P ... Prism I ... Image plane ( (Imaging surface)
DESCRIPTION OF SYMBOLS 112 ... Operation part 113 ... Control part 114 ... Bus 115 ... Bus 116 ... Imaging drive circuit 117 ... Temporary storage memory 118 ... Image processing part 119 ... Storage medium part 120 ... Display part 121 ... Setting information storage memory part 122 ... Bus 124 ... CDS / ADC section 140 ... digital camera 141 ... photographing optical system 142 ... photographing optical path 143 ... viewfinder optical system 144 ... viewfinder optical path 145 ... shutter button 146 ... flash 147 ... liquid crystal display monitor 149 ... CCD
150: cover member 151 ... processing means 152 ... recording means 153 ... finder objective optical system 155 ... erecting prism 157 ... field frame 159 ... eyepiece optical system

Claims (16)

A zoom lens having a reflecting member having a reflecting surface that bends the optical path;
An image sensor disposed on the image side of the zoom lens and having an imaging surface and converting an image formed on the imaging surface by the zoom lens into an electrical signal;
The zoom lens is in order from the object side.
A first refractive power first lens group having the reflecting member;
A second lens unit having negative refractive power;
A third lens group having positive refractive power;
A fourth lens unit having positive refractive power;
A fifth lens unit having positive refractive power;
Have
When zooming from the wide-angle end to the telephoto end,
Fixing the first lens group and the third lens group to the imaging surface;
The second lens group moves to the image side at the telephoto end with respect to the wide angle end,
The fourth lens group moves toward the object side at the telephoto end with respect to the wide angle end to change the interval between the lens groups,
Further, the first lens group includes a negative lens component having a negative refractive power disposed on the object side of the reflecting member, and a positive lens component having a positive refractive power disposed on the image side of the reflecting member. The positive lens component is a cemented lens component obtained by cementing at least two lenses having different refractive indexes and Abbe numbers.   The cemented lens component is a biconvex lens component. 2. The image pickup apparatus according to claim 1, wherein the total number of lens components arranged on the image side of the reflecting member is 1 in the first lens group.   The imaging apparatus according to claim 2, wherein the total number of lenses in the cemented lens component is two.   The imaging device according to any one of claims 1 to 3, wherein the cemented lens component includes a plurality of aspheric lenses obtained by cementing aspheric surfaces.   5. The image pickup apparatus according to claim 1, wherein the total number of reflecting surfaces in the zoom lens is one.   The imaging apparatus according to claim 5, wherein the reflection member in the first lens group is a prism having an internal reflection surface and a refractive index exceeding 1.3. 7. The cemented lens component in the first lens group is a biconvex lens component, and satisfies the following conditional expression (1). Imaging device.
5.0 <(| r ₁ | + | r ₂ |) / d ₁ <24.0 (1)
However,
r1 is the paraxial radius of curvature of the object side surface of the cemented lens component;
r2 is the paraxial radius of curvature of the image side surface of the cemented lens component;
d1 is the thickness of the cemented lens component on the optical axis. The imaging device according to any one of claims 1 to 7, wherein the cemented lens component in the first lens group satisfies the following conditional expression (2).
ν _dave > 28.0 (2)
However,
[nu _dave is the average value of Abbe numbers of each lens in the cemented lens component. 9. The imaging apparatus according to claim 1, wherein the second lens group and the third lens group satisfy the following conditional expression (3).
0.001 <| f _2g / f _3g | <0.40 (3)
However,
f _2g is the focal length of the second lens group,
f _3g is a focal length of the third lens group. The imaging device according to any one of claims 1 to 9, wherein the first lens group satisfies the following conditional expression (4).
1.0 <f _1g / f _w <4.0 (4)
However,
f _1g is a focal length of the first lens group,
_fw is a focal length of the entire zoom lens system at the wide angle end. The imaging apparatus according to claim 1, wherein the zoom lens satisfies the following conditional expression (5).
0.5 <D / _ft <3.0 (5)
However,
D is the optical path length along the optical axis from the object side refractive surface of the most object side lens in the zoom lens to the imaging surface,
f _t is the focal length of the entire zoom lens system at the telephoto end. The image pickup apparatus according to any one of claims 1 to 11, wherein the zoom lens satisfies the following conditional expression (6).
3.8 < _ft / _fw <10.0 (6)
However,
_ft is the focal length of the entire zoom lens system at the telephoto end,
and f _w is a focal length of the zoom lens system in the wide-angle end.   The imaging device according to claim 1, wherein the cemented lens component includes a resin lens. The imaging device according to any one of claims 1 to 13, wherein the cemented lens component in the first lens group satisfies the following conditional expression (7).
3.0 <ν _max −ν _min (7)
However,
ν _max is the maximum value among the Abbe numbers of each lens in the cemented lens component in the first lens group,
ν _min is the minimum value among the Abbe numbers of the lenses in the cemented lens component in the first lens group. The imaging apparatus according to any one of claims 1 to 14, wherein the cemented lens component in the first lens group satisfies the following conditional expression (8).
0.70 <D _max / D _ce <1.0 (8)
However,
D _max is the maximum value of the thickness on the optical axis of each lens in the cemented lens component in the first lens group,
D _ce is the thickness on the optical axis of the cemented lens component in the first lens group.   The imaging according to any one of claims 1 to 15, further comprising a processing circuit that converts a signal including distortion of the zoom lens formed on the imaging surface into a signal obtained by correcting the distortion. apparatus.

Images