JP2007108702A - Imaging optical system and electronic imaging device having it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a zoom lens for miniaturizing and thinning by lessening the number of the constituents of an optical system, and to provide an electronic imaging device having it. <P>SOLUTION: The imaging optical system has a positive lens group, a negative lens group, and a diaphragm. The optical system arranges the negative lens group at an object side from the diaphragm. The negative lens group has a cemented lens cementing a plurality of lenses. When a straight line expressed by Nd=α×νd+β (where, α=-0.017) is set in an orthogonal coordinate system making Nd of a horizontal axis and making νd of a vertical axis, Nd and νd of at least one lens constituting the cemented lens are included in both a region decided by straight lines at a lower limit and upper limit of the following condition inequality (1) and a region determined by the following condition inequalities (2) and (3). 1.45<β<2.15... (1), 1.30<Nd<2.20... (2), and 3<νd<12... (3). Here, Nd denotes a refractive index and νd denotes Abbe's number respectively. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an imaging optical system used for an extremely small imaging module and an electronic imaging apparatus having the imaging optical system.

  In recent years, digital cameras have become widespread as next-generation cameras that replace silver salt 35 mm film cameras. Recently, digital cameras have become increasingly smaller and thinner. Also, camera functions (hereinafter referred to as imaging modules) have been mounted on mobile phones that are becoming popular at the same time. In order to mount this imaging module on a mobile phone, the optical system must be smaller and thinner than the optical system of a digital camera. In particular, a zoom lens is required to be small and thin. However, zoom lenses that are small enough to be installed in mobile phones are not well known.

As typical means for reducing the size and thickness of the zoom lens, the following two means can be considered. That is,
A. A retractable lens barrel is used to house the optical system in the thickness (depth) direction of the housing. The collapsible lens barrel is a lens barrel having a structure in which an optical system protrudes from the camera case during photographing and is housed in the camera case when carried.
B. A bending optical system is employed to accommodate the optical system in the width direction or height direction of the casing. This bending optical system is an optical system configured to bend the optical path (optical axis) of the optical system with a reflective optical element such as a mirror or a prism.

  A conventional example using the means A is described in, for example, the following Patent Document 1, and a conventional example using the means B is, for example, described in the following Patent Document 2. .

JP 2002-365545 A JP 2003-43354 A

  However, in the configuration using the means A described in Patent Document 1, the number of lenses constituting the optical system or the number of moving lens groups is still large, and it is difficult to reduce the size and thickness of the housing. .

  The configuration using the means B described in Patent Document 2 is easier to make the housing thinner than the case using the means A, but the amount of movement of the movable lens group at the time of zooming, The number of lenses constituting the system tends to increase. Therefore, it is not suitable for miniaturization in volume.

  The present invention has been made in view of the above-described conventional problems, and enables a compact and thin imaging optical system, and a compact, thin and wide angle, and various aberrations are corrected well. An object of the present invention is to provide an electronic imaging apparatus.

In order to achieve the above object, an imaging optical system according to the present invention is an imaging optical system having a positive lens group, a negative lens group, and a stop, wherein the negative lens group is closer to the object side than the stop. Arranged, the negative lens group has a cemented lens formed by cementing a plurality of lenses,
When a straight line represented by Nd = α × νd + β (where α = −0.017) is set in an orthogonal coordinate system in which the horizontal axis is Nd and the vertical axis is νd,
The area defined by the straight line when the lower limit value is within the range of the conditional expression (1) and the straight line when the upper limit value is satisfied, and the area determined by the following conditional expressions (2) and (3) Nd and νd of at least one lens constituting the cemented lens are included.
1.45 <β <2.15 (1)
1.30 <Nd <2.20 (2)
3 <νd <12 (3)
Here, Nd represents a refractive index and νd represents an Abbe number.

  Further, when one lens in which Nd and νd are included in both the areas is a predetermined lens, the optical axis center thickness of the predetermined lens is larger than the optical axis center thicknesses of the other lenses constituting the cemented lens. Is also preferably thin.

Moreover, it is preferable that the following conditional expression is satisfied.
0.22 <t1 <2.0
However, t1 is the optical axis center thickness of the predetermined lens.

  Further, it is desirable that the cemented lens is a compound lens in which a resin is adhered and cured on the lens surface of one lens constituting the cemented lens.

  In addition, the cemented lens is preferably a compound lens formed by closely bonding glass to the lens surface of one lens constituting the cemented lens.

  Further, it is preferable that the imaging optical system is a zoom lens whose object side is the positive group.

  Further, it is preferable that the imaging optical system is a zoom lens whose negative side is the most object side.

  The imaging optical system preferably has a bending prism.

  Further, it is preferable that the prisms are in a group closest to the object side.

The electronic imaging device of the present invention is obtained by capturing an image formed through the imaging optical system with any one of the imaging optical system of the present invention, the electronic imaging device, and the imaging electronic imaging device. Image processing means for processing the obtained image data and outputting it as image data obtained by changing the shape of the formed image, wherein the image forming optical system is a zoom lens, and the zoom lens is infinite object point alignment. It is characterized by satisfying the following conditional expression in the dark.
0.7 <y ₀₇ / (fw · tan ω _07w ) <0.96
However, y ₀₇ is y ₀₇ = 0.7y ₁₀₀ where y ₁₀ is the distance (maximum image height) from the center to the farthest point in the effective imaging plane (in the plane where imaging is possible) of the electronic imaging device. expressed. Further, ω _07w is an angle with respect to the optical axis in the object point direction corresponding to the image point connecting from the center on the imaging surface to the position of y ₀₇ at the wide angle end.

  According to the present invention, it is possible to reduce both the volume and the thickness of the imaging optical system, and in the electronic imaging device of the present invention, it is possible to correct various aberrations and widen the angle. Coexistence is possible.

Prior to the description of the embodiments, the effects of the present invention will be described.
The imaging optical system of the present invention is a imaging optical system having a positive lens group, a negative lens group, and a stop. A negative lens group is disposed on the object side of the stop, and a plurality of negative lens groups are provided. The basic configuration is to have a cemented lens formed by cementing these lenses.

  As described above, in the imaging optical system according to the present invention, the cemented lens is used for the negative lens group on the object side from the stop, so that the variation of the lateral chromatic aberration at the time of zooming in the zoom lens can be easily suppressed. In addition, it is possible to sufficiently suppress the occurrence of color bleeding over the entire zoom range with a small number of lenses. In addition, in order to reduce the size of the entire optical system, it is easy to apply refractive power without making the negative lens group (negative lens group closer to the object side from the stop) as thick as possible. Easy to achieve.

When a straight line represented by Nd = α × νd + β (where α = −0.017) is set in an orthogonal coordinate system in which the horizontal axis is Nd and the vertical axis is νd,
The area defined by the straight line when the lower limit value is within the range of the conditional expression (1) and the straight line when the upper limit value is satisfied, and the area determined by the following conditional expressions (2) and (3) It is desirable that Nd and νd of at least one lens constituting the cemented lens are included.
1.45 <β <2.15 (1)
1.30 <Nd <2.20 (2)
3 <νd <12 (3)
Here, Nd represents a refractive index and νd represents an Abbe number.

  Here, the glass material means a lens material such as glass or resin. Further, as the cemented lens, a lens in which a plurality of lenses made of these glass materials selected as appropriate is cemented is used.

  If the lower limit of conditional expression (1) is not reached, the refractive index is low, so the effect of providing an aspheric surface on the air contact surface side is small, and it becomes difficult to correct spherical aberration, coma aberration, and distortion aberration. Alternatively, since the Abbe number is low, chromatic aberration can be corrected as a very thin cemented lens. However, if the air contact surface side is made aspherical, higher-order lateral chromatic aberration and color coma are likely to occur, and the degree of freedom in correcting aberrations is reduced.

  If the upper limit value of conditional expression (1) is exceeded, the power and thickness of the cemented lens are required to some extent in order to correct chromatic aberration, so that it is easily affected by the optical characteristics due to the environment of the material.

  If the lower limit of conditional expression (2) is not reached, the effect when an aspheric surface is provided on the air contact surface side is small, and it becomes difficult to correct spherical aberration, coma aberration, and distortion aberration.

  If the upper limit of conditional expression (2) is exceeded, in the case of a material containing organic matter, if the refractive index is too high, the temperature dispersion becomes too large and the optical characteristics due to the environment tend to become unstable. Also, the reflectivity becomes too high, and ghosting is likely to occur even if the coating is optimized.

  If the lower limit of conditional expression (3) is not reached, chromatic aberration can be corrected as an extremely thin cemented lens. However, if the air contact surface is made aspherical, higher-order lateral chromatic aberration and color coma are likely to occur, and the degree of freedom in correcting aberrations. Decrease.

  If the upper limit of conditional expression (3) is exceeded, it is necessary to increase the refractive power of the cemented lens in order to correct chromatic aberration, which is advantageous for correcting the Petzval sum. It becomes easy to receive.

It is more preferable that the following conditional expression (1 ′) is satisfied.
1.48 <β <2.04 (1 ′)
Further, it is more preferable that the following conditional expression (1 ″) is satisfied.
1.50 <β <2.00 (1 ″)
It is more preferable that the following conditional expression (2 ′) is satisfied.
1.58 <Nd <2.10 (2 ′)
Furthermore, it is more preferable that the following conditional expression (2 ″) is satisfied.
1.63 <Nd <1.95 (2 ″)
It is more preferable that the following conditional expression (3 ′) is satisfied.
5 <νd <10 (3 ′)
Furthermore, it is more preferable that the following conditional expression (3 ″) is satisfied.
6 <νd <9 (3 ″)

  The cemented lens is composed of a lens having the values of Nd and νd (hereinafter referred to as a “predetermined lens”) included in both of the above-mentioned areas and another lens, and the predetermined lens has an optical axis center thickness. It is preferably thinner than the center thickness of the optical axis of the other lens. By doing in this way, the further favorable correction effect of each said aberration and the thickness reduction of a lens group are realizable.

  The cemented lens is preferably a compound lens in which a resin is adhered and cured on the lens surface (other lens surface) in order to improve manufacturing accuracy. Here, the contact-cured resin corresponds to the predetermined lens.

  Further, the cemented lens is advantageous in terms of light resistance, chemical resistance, and the like, and is preferably a compound lens in which glass is adhered and cured on the lens surface (other lens surface). Here, the glass that has been subjected to close contact hardening corresponds to the predetermined lens.

In addition, when the cemented lens is molded in a small size and stably, the optical axis center thickness t1 of a predetermined lens (Nd and νd included in both the above regions) is expressed by the following conditional expression (4). It is good to satisfy.
0.22 <t1 <2.0 (4)
It is more preferable that the following conditional expression (4 ′) is satisfied.
0.3 <t1 <1.5 (4 ′)
Furthermore, it is more preferable that the following conditional expression (4 ″) is satisfied.
0.32 <t1 <1.0 (4 ")

  Further, the imaging optical system is preferably a zoom lens in which the most object side is a positive group from the viewpoint of increasing the zoom magnification and improving the brightness of the lens.

  In addition, the image forming optical system is preferably a zoom lens having a negative group on the most object side in view of miniaturization.

  Further, the imaging optical system preferably has a prism for bending in order to reduce the size of the optical system with respect to the photographing direction.

  In order to further reduce the thickness of the imaging optical system, it is preferable that the prism is in the group closest to the object side.

By the way, when the pixel size of the electronic image sensor becomes smaller than a certain level, the component having the Nyquist frequency or higher disappears due to the influence of diffraction. Therefore, if this is used, the optical low-pass filter can be omitted. This is also preferable from the viewpoint of making the entire optical system as thin as possible.
Therefore, it is preferable that the following conditional expression (6) is satisfied.
Fw ≧ a (μm) (6)
Here, Fw is the release F value at the wide-angle end, and a is the horizontal inter-pixel distance (unit: μm) of the electronic image sensor.
When the conditional expression (6) is satisfied, the optical low-pass filter need not be arranged in the optical path.
Therefore, the optical system can be reduced in size.

  When the above condition (6) is satisfied, it is preferable that the aperture stop is only opened from the viewpoint of ensuring image quality. This means that the optical system in this case is an optical system in which the diameter of the aperture stop is always constant. Further, in the optical system in this case, a narrowing operation is not necessary, so that the narrowing mechanism can be omitted. Therefore, the size can be reduced accordingly. If the conditional expression (6) is not satisfied, an optical low-pass filter is necessary.

Moreover, it is more preferable that the conditional expression (6 ′) is satisfied.
Fw ≧ 1.2a (μm) (6 ′)
Furthermore, it is even more preferable that the conditional expression (6 ″) is satisfied.
Fw ≧ 1.4a (μm) (6 ″)

Finally, an electronic imaging device will be described. As the electronic imaging device, a device that achieves both a reduction in depth and a wide angle of view is preferable.
Here, it is assumed that an object at infinity is imaged by an optical system having no distortion. In this case, since the image formed has no distortion,
f = y / tan ω
Is established.
Where y is the height of the image point from the optical axis, f is the focal length of the imaging system, ω is the angle with respect to the optical axis in the object direction corresponding to the image point connecting from the center on the imaging surface to the y position. is there.

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

  Therefore, it is preferable to use a zoom lens as an imaging optical system in the electronic imaging apparatus. As the zoom lens, it is preferable to use an optical system that intentionally has a large barrel distortion, particularly at a focal length near the wide-angle end. In this case, it is possible to achieve a wider angle of view of the optical system as much as it is not necessary to correct distortion. However, the image of the object is formed on the electronic image pickup device in a state having barrel-shaped distortion. Therefore, in the electronic imaging device, image data obtained by the electronic imaging element is processed by image processing. In this processing, the image data (image shape) is changed so as to correct the barrel distortion. In this way, the finally obtained image data is image data having a shape substantially similar to the object. Therefore, an object image may be output to a CRT or printer based on the image data.

Here, it is preferable to adopt an imaging optical system (zoom lens) that satisfies the following conditional expression (7) when focusing on an object point at infinity.
0.7 <y ₀₇ / (fw · tan ω _07w ) <0.96 (7)
However, when y ₀₇ is the distance to the farthest point from the center in the effective image pickup plane of the electronic imaging device (imaging possible in-plane) (maximum image height) was y _10, the table as y ₀₇ = 0.7y ₁₀ Is done. Further, ω _07w is an angle with respect to the optical axis in the object point direction corresponding to the image point connecting from the center on the imaging surface at the wide angle end to the position of y ₀₇ .

  Conditional expression (7) defines the degree of barrel distortion at the zoom wide-angle end. If conditional expression (7) is satisfied, it becomes possible to capture information with a wide angle of view without enlarging the optical system. Note that an image distorted in a barrel shape is photoelectrically converted by an electronic imaging device, and becomes image data distorted in a barrel shape. However, the image data distorted into a barrel shape is electrically processed by an image processing means which is a signal processing system of the electronic imaging apparatus, corresponding to a change in the shape of the image. In this way, even if the image data finally output from the image processing means is reproduced on the display device, the distortion is corrected and an image substantially similar to the subject shape is obtained.

  Here, when the value exceeds the upper limit value of the conditional expression (7), particularly when a value close to 1 is taken, correction corresponding to the fact that the distortion aberration is optically corrected is performed by the image processing means. However, it is difficult to capture an image over a wide viewing angle while maintaining downsizing of the optical system. On the other hand, if the lower limit value of conditional expression (7) is not reached, when the image distortion due to the distortion of the optical system is corrected by the image processing means, the stretching ratio in the radial direction around the angle of view becomes too high. As a result, the sharpness degradation at the periphery of the image becomes conspicuous.

  On the other hand, when the conditional expression (7) is satisfied, it is possible to reduce the size and widen the angle of the optical system (make the vertical angle of view of distortion more than 38 °).

It is more preferable that the following conditional expression (7 ′) is satisfied.
0.75 <y ₀₇ / (fw · tan ω _07w ) <0.94 (7 ')
Furthermore, it is even more preferable that the following conditional expression (7 ″) is satisfied.
_{0.80 <y 07 / (fw ·} tanω 07w) <0.92 ... (7 ")

  The imaging optical system according to the present invention satisfies the above-described conditional expressions and structural characteristics individually or satisfies the requirements so that the volume of the imaging optical system can be reduced even when an electronic imaging device having a large number of pixels is used. This makes it possible to achieve both a reduction in thickness and thickness, and to achieve good aberration correction. In addition, the imaging optical system of the present invention can be provided with (satisfied with) the above conditional expressions and structural features in combination. In this case, further downsizing / thinning or better aberration correction can be achieved. In addition, the electronic imaging apparatus having the imaging optical system of the present invention can achieve both a reduction in volume and a reduction in volume of the imaging optical system. Can be achieved.

Next, embodiments of the present invention will be described with reference to the drawings.
As the zoom lens of the present invention, a 5-group configuration, a 4-group configuration, or a 3-group configuration can be considered. In a zoom lens having a five-group configuration, from the object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, a fourth lens group having a negative refractive power, and a positive refraction. It is preferable to arrange the lens groups in the order of the fifth lens group of the force.

  Here, the first lens group preferably includes a negative lens, a prism, and a positive lens. At this time, it is more preferable to dispose these in the order of the negative lens, the prism, and the positive lens from the object side. Note that the first lens group may be composed of only one negative lens, one prism, and one positive lens.

  The second lens group preferably includes a cemented lens and a positive lens. At this time, it is more preferable to dispose a positive lens on the image side of the cemented lens. More preferably, the cemented lens is composed of a positive lens and a negative lens, and the cemented lens is arranged so that the negative lens is positioned on the image side. Alternatively, it is more preferable that the cemented lens is constituted by a negative lens, and the cemented lens is arranged so that the negative lens having a thin central thickness (heart thickness) is positioned on the object side. Note that the second lens group may be composed of only one cemented lens and one positive lens. In this case, the cemented lens is composed of one positive lens and one negative lens, or two negative lenses.

  The third lens group preferably includes a positive lens and a negative lens. At this time, it is more preferable to form a cemented lens with a positive lens and a negative lens, and arrange the cemented lens so that the positive lens is located on the object side. Note that the third lens group may be configured by only one cemented lens. In this case, the cemented lens is composed of one positive lens and one negative lens.

  The fourth lens group preferably includes a negative lens. At this time, it is more preferable that the fourth lens group is constituted by only one negative lens.

  The fifth lens group preferably includes a positive lens. At this time, it is more preferable that the fifth lens group is constituted by only one positive lens.

  In another zoom lens having a five-group configuration, from the object side, a first lens group having a positive refractive power, 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. It is preferable to dispose each lens group in the order of the group and the fifth lens group having positive refractive power.

  Here, the first lens group preferably includes a positive lens and a negative lens. At this time, it is more preferable to form a cemented lens with a positive lens and a negative lens, and arrange the cemented lens so that the positive lens is located on the object side. Note that the first lens group may be composed of only one cemented lens. In this case, the cemented lens is composed of one positive lens and one negative lens.

  The second lens group preferably includes a negative lens, a prism, and a cemented lens. At this time, it is more preferable to dispose these in the order of the negative lens, the prism, and the cemented lens from the object side. More preferably, the cemented lens is composed of a positive lens and a negative lens, and the cemented lens is arranged so that the negative lens is located on the object side. Note that the second lens group may be configured by only one negative lens, one prism, and one cemented lens. In this case, the cemented lens is composed of one positive lens and one negative lens.

  The third lens group preferably includes a positive lens and a cemented lens. At this time, it is preferable to dispose a positive lens on the object side of the cemented lens. More preferably, the cemented lens is configured by a positive lens and a negative lens, and the cemented lens is disposed so that the positive lens is positioned on the object side. Note that the third lens group may be composed of only one positive lens and one cemented lens. In this case, the cemented lens is composed of one positive lens and one negative lens.

  The fourth lens group preferably includes a positive lens. At this time, it is more preferable that the fourth lens group is constituted by only one positive lens.

  The fifth lens group preferably includes a positive lens. At this time, it is more preferable that the fifth lens group is constituted by only one positive lens.

  Further, in the zoom lens having a four-group configuration, in order from the object side, a first lens group having a negative refractive power, a second lens group having a positive refractive power, a third lens group having a negative refractive power, and a fourth lens group having a positive refractive power. It is preferable to arrange the lens groups in this order.

Here, the first lens group preferably includes a prism and at least two cemented lenses. At this time, it is more preferable to dispose these in the order of one cemented lens, prism, and the other cemented lens from the object side. Further, it is preferable that one cemented lens is composed of a positive lens and a negative lens, and the one cemented lens is arranged so that the negative lens is positioned on the object side. Alternatively, one cemented lens may be constituted by only a negative lens, and one cemented lens may be arranged so that a negative lens having a thick central thickness (heart thickness) is positioned on the object side.
Further, it is preferable that the other cemented lens is composed of a positive lens and a negative lens, and the other cemented lens is arranged so that the positive lens is located on the object side.
The first lens group may be composed of only one prism and two cemented lenses. In this case, the cemented lens is composed of one positive lens and one negative lens, or two negative lenses.

  The second lens group preferably includes a positive lens and a negative lens. At this time, it is more preferable to form a cemented lens with a positive lens and a negative lens, and arrange the cemented lens so that the positive lens is located on the object side. Note that the second lens group may be constituted by only one cemented lens. In this case, the cemented lens is composed of one positive lens and one negative lens.

  The third lens group preferably includes a positive lens and a negative lens. At this time, it is more preferable to form a cemented lens with a positive lens and a negative lens, and arrange the cemented lens so that the negative lens is located on the object side. Note that the third lens group may be configured by only one cemented lens. In this case, the cemented lens is composed of one positive lens and one negative lens.

  The fourth lens group preferably includes a positive lens and a negative lens. At this time, it is more preferable to form a cemented lens with a positive lens and a negative lens, and arrange the cemented lens so that the positive lens is located on the object side. Note that the fourth lens group may be composed of only one cemented lens. In this case, the cemented lens is composed of one positive lens and one negative lens.

  In another zoom lens having a four-group configuration, in order from the object side, a first lens group having a positive refractive power, 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. It is preferable to arrange the lens groups in the order of lens groups.

  Here, the first lens group preferably includes a positive lens, a prism, and a negative lens. At this time, it is preferable to arrange the positive lens, the prism, and the negative lens in this order from the object side. Note that the first lens group may be composed of only one positive lens, one prism, and one negative lens.

  The second lens group preferably includes a cemented lens. At this time, it is more preferable to form a cemented lens with a positive lens and a negative lens, and arrange the cemented lens so that the negative lens is located on the object side. Further, a positive lens may be cemented on the image side. Note that the second lens group may be constituted by only one cemented lens. In this case, the cemented lens includes two positive lenses and one negative lens.

  The third lens group preferably includes a positive lens and a cemented lens. At this time, it is preferable to dispose a positive lens on the object side of the cemented lens. More preferably, the cemented lens is configured by a positive lens and a negative lens, and the cemented lens is disposed so that the positive lens is positioned on the object side. Note that the third lens group may be composed of only one positive lens and one cemented lens. In this case, the cemented lens is composed of one positive lens and one negative lens.

  The fourth lens group preferably includes a positive lens. At this time, it is more preferable that the fourth lens group is constituted by only one positive lens.

  Further, in another zoom lens having a four-group structure, in order from the object side, a first lens group having a negative refractive power, a second lens group having a positive refractive power, a third lens group having a positive refractive power, and a first lens group having a positive refractive power. Each lens group is preferably arranged in the order of four lens groups.

  Here, the first lens group preferably includes a positive lens, a prism, and a cemented lens. At this time, it is preferable to arrange the positive lens, the prism, and the cemented lens in this order from the object side. It is more preferable that the cemented lens is constituted by a positive lens and a negative lens, and the cemented lens is arranged so that the negative lens is located on the object side. Note that the first lens group may be composed of only one positive lens, one prism, and one cemented lens. In this case, the cemented lens is composed of one positive lens and one negative lens.

  The second lens group preferably includes a positive lens and a cemented lens. At this time, it is preferable to dispose a positive lens on the image side of the cemented lens. More preferably, the cemented lens is configured by a positive lens and a negative lens, and the cemented lens is disposed so that the positive lens is positioned on the object side. Note that the second lens group may be composed of only one positive lens and one cemented lens. In this case, the cemented lens is composed of one positive lens and two negative lenses.

  The third lens group preferably includes a positive lens. At this time, it is more preferable that the third lens group is constituted by only one negative lens.

  The fourth lens group preferably includes a positive lens. At this time, it is more preferable that the fourth lens group is constituted by only one positive lens.

  Further, in the zoom lens having a three-group configuration, the respective lens groups are arranged in order of the first lens group having a negative refractive power, the second lens group having a positive refractive power, and the third lens group having a positive refractive power in order from the object side. It is preferable to do.

  Here, the first lens group preferably includes a cemented lens and a positive lens. At this time, it is more preferable to dispose a positive lens on the image side of the cemented lens. More preferably, the cemented lens is composed of a positive lens and a negative lens, and the cemented lens is arranged so that the negative lens is located on the object side. Note that the first lens group may be composed of only one cemented lens and one positive lens. In this case, the cemented lens is composed of one positive lens and one negative lens.

  The second lens group preferably includes a cemented lens and a positive lens. At this time, it is more preferable to dispose a positive lens on the image side of the cemented lens. More preferably, the cemented lens is composed of a positive lens and a negative lens, and the cemented lens is arranged so that the positive lens is located on the object side. Note that the second lens group may be composed of only one cemented lens and one positive lens. In this case, the cemented lens is composed of one positive lens and one negative lens.

  The third lens group preferably includes a positive lens. At this time, it is more preferable to form the third lens group with only one positive lens.

  In addition, the refractive power of one lens can be distributed to two lenses. Therefore, in each lens group described above, one lens can be replaced with two lenses. However, from the viewpoint of size reduction and thickness reduction, it is preferable that the number of lenses replaced with two lenses is only one in each lens group.

  FIG. 1 is a cross-sectional view along the optical axis showing an optical configuration at the time of focusing on an object point at infinity at the wide angle end of a zoom lens according to Embodiment 1 of the present invention.

  FIG. 2 is a diagram showing spherical aberration, astigmatism, distortion, and lateral chromatic aberration when the zoom lens according to Example 1 is focused on an object point at infinity, where (a) is a wide angle end, (b) is an intermediate, (c) shows the state at the telephoto end.

  As shown in FIG. 1, the zoom lens according to the first embodiment includes, in order from the object side, a first lens group G1, a second lens group G2, an aperture stop S, a third lens group G3, and a fourth lens group. G4 and the fifth lens group G5 are included. In the figure, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

  The first lens group G1 includes a negative meniscus lens L111 having a convex surface directed toward the object side, a prism L112, and a biconvex lens L113, and has a positive refractive power as a whole.

  The second lens group G2 includes a cemented lens of a positive meniscus lens L121 having a convex surface directed toward the image side and a biconcave lens L122, and a positive meniscus lens L123 having a convex surface directed toward the object side, and has a negative refracting power as a whole. have. The positive meniscus lens L121 having a convex surface facing the image side is a lens having a thin heart thickness.

  The third lens group G3 is composed of a cemented lens made up of a biconvex lens L131 and a biconcave lens L132, and has a positive refractive power as a whole.

  The fourth lens group G4 includes a negative meniscus lens L141 having a convex surface directed toward the object side, and has a negative refracting power as a whole.

  The fifth lens group G5 includes a positive meniscus lens L142 having a convex surface directed toward the object side, and has a positive refracting power as a whole.

  When zooming from the wide-angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 is moved to the image side, the aperture stop S is fixed, and the third lens group G3 is moved to the object side. The fourth lens group G4 once moves to the image side, then moves to the object side, and moves to the image side of the fifth lens group G5.

  The aspherical surfaces are the object side surface of the biconvex lens L113 in the first lens group G1, the object side surface of the positive meniscus lens L121 with the convex surface facing the image side in the second lens group G2, and the image side of the biconcave lens L122. The object side surface of the biconvex lens L131 in the third lens group G3, the image side surface of the biconcave lens L132, and the object side of the positive meniscus lens L142 with the convex surface facing the object side in the fifth lens group G5. It is provided on the surface.

Next, numerical data of optical members constituting the zoom lens of Example 1 are shown.
In the numerical data of Example 1, r1, r2,... Are the radius of curvature of each lens surface, d1, d2,... Are the thickness or air spacing of each lens, and nd1, nd2,. Are the Abbe number of each lens, Fno. Is the F number, f is the focal length of the entire system, and D0 is the distance from the object to the first surface. FIG. 52 shows the relationship between the r and d numbers in the numerical data and the optical configuration (lens surface, thickness, air spacing).

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

Next, numerical data of this embodiment will be listed.
Numerical data 1
r1 = 25.36
d1 = 1 Nd1 = 1.8061 νd1 = 40.92
r2 = 10.004
d2 = 2.9
r3 = ∞
d3 = 12 Nd3 = 1.8061 νd3 = 40.92
r4 = ∞
d4 = 0.3
r5 = 33.927 (Aspherical surface)
d5 = 3.54 Nd5 = 1.741 νd5 = 52.64
r6 = -27.177
d6 = D6
r7 = -461.447 (Aspherical surface)
d7 = 0.1 Nd7 = 1.41244 νd7 = 12.42
r8 = -92.289
d8 = 0.7 Nd8 = 1.8044 νd8 = 39.59
r9 = 6.012 (Aspherical surface)
d9 = 0.7
r10 = 8.081
d10 = 2.2 Nd10 = 1.7552 νd10 = 27.51
r11 = 63.91
d11 = D11
r12 = aperture
d12 = D12
r13 = 7.812 (Aspherical surface)
d13 = 5.49 Nd13 = 1.6935 νd13 = 53.21
r14 = -11.451
d14 = 1 Nd14 = 1.84666 νd14 = 23.78
r15 = 33.504 (Aspherical surface)
d15 = D15
r16 = 26.9
d16 = 0.6 Nd16 = 1.48749 νd16 = 70.23
r17 = 9.047
d17 = D17
r18 = 9.921 (Aspherical surface)
d18 = 1.8 Nd18 = 1.7432 νd18 = 49.34
r19 = 236.372
d19 = D19
r20 = ∞
d20 = 1.9 Nd20 = 1.54771 νd20 = 62.84
r21 = ∞
d21 = 0.8
r22 = ∞
d22 = 0.75 Nd22 = 1.51633 νd22 = 64.14
r23 = ∞
d23 = D23

Aspherical coefficient fifth surface
k = 0
A4 = 1.21460E-05
A6 = 2.15403E-07
A8 = 0
7th page
k = 0
A4 = -6.49637E-04
A6 = 4.67785E-05
A8 = -1.11723E-06
9th page
k = 0
A4 = -7.36988E-04
A6 = 3.10428E-05
A8 = -1.20842E-06
13th page
k = 0
A4 = 1.33646E-04
A6 = 1.99909E-06
A8 = 8.19731E-08
15th page
k = 0
A4 = 7.65187E-04
A6 = 4.66680E-06
A8 = 1.27977E-06
18th page
k = 0
A4 = -7.77242E-05
A6 = 8.66914E-06
A8 = -2.36765E-07

Zoom data
When D0 (distance from the object to the first surface) is ∞
Wide-angle end Middle Telephoto end
Focal length 6.005 13.699 17.993
FNO. 2.88 4.93 6.03
D6 0.8 7.08 8.33
D11 8.92 2.64 1.38
D12 11.78 4.21 1.19
D15 1.21 12.51 14.59
D17 1.92 2.3 3.68
D19 5.08 0.96 0.51
D23 1.36 1.36 1.36

  FIG. 3 is a cross-sectional view along the optical axis showing the optical configuration at the time of focusing on an object point at infinity at the wide angle end of the zoom lens according to Example 2 of the present invention.

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

  As shown in FIG. 3, the zoom lens of Example 2 includes, in order from the object side, the first lens group G1, the second lens group G2, the aperture stop S, the third lens group G3, and the fourth lens group. G4 and the fifth lens group G5 are included. In the figure, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

  The first lens group G1 includes a negative meniscus lens L111 having a convex surface directed toward the object side, a prism L112, and a biconvex lens L113, and has a positive refractive power as a whole.

  The second lens group G2 includes a cemented lens of a positive meniscus lens L121 having a convex surface directed toward the image side and a biconcave lens L122, and a positive meniscus lens L123 having a convex surface directed toward the object side, and has a negative refracting power as a whole. have. The positive meniscus lens L121 having a convex surface facing the image side is a lens having a thin heart thickness.

  The third lens group G3 is composed of a cemented lens made up of a biconvex lens L131 and a biconcave lens L132, and has a positive refractive power as a whole.

  The fourth lens group G4 includes a negative meniscus lens L141 having a convex surface directed toward the object side, and has a negative refracting power as a whole.

  The fifth lens group G5 includes a positive meniscus lens L142 having a convex surface directed toward the object side, and has a positive refracting power as a whole.

  When zooming from the wide-angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 is moved to the image side, the aperture stop S is fixed, and the third lens group G3 is moved to the object side. The fourth lens group G4 once moves to the image side, then moves to the object side, and moves to the image side of the fifth lens group G5.

  The aspherical surfaces are the object side surface of the biconvex lens L113 in the first lens group G1, the object side surface of the positive meniscus lens L121 with the convex surface facing the image side in the second lens group G2, and the image side of the biconcave lens L122. The object side surface of the biconvex lens L131 in the third lens group G3, the image side surface of the biconcave lens L132, and the object side of the positive meniscus lens L142 with the convex surface facing the object side in the fifth lens group G5. It is provided on the surface.

Next, numerical data of this embodiment will be listed.
Numerical data 2
r1 = 24.594
d1 = 1 Nd1 = 1.8061 νd1 = 40.92
r2 = 10.001
d2 = 2.9
r3 = ∞
d3 = 12 Nd3 = 1.8061 νd3 = 40.92
r4 = ∞
d4 = 0.3
r5 = 36.646 (Aspherical surface)
d5 = 3.54 Nd5 = 1.741 νd5 = 52.64
r6 = -28.175
d6 = D6
r7 = -412.042 (aspherical surface)
d7 = 0.1 Nd7 = 1.42001 νd7 = 6.55
r8 = -82.408
d8 = 0.7 Nd8 = 1.804 νd8 = 46.57
r9 = 5.748 (aspherical surface)
d9 = 0.7
r10 = 7.508
d10 = 2.2 Nd10 = 1.762 νd10 = 40.1
r11 = 49.209
d11 = D11
r12 = aperture
d12 = D12
r13 = 7.579 (aspherical surface)
d13 = 5.88 Nd13 = 1.6935 νd13 = 53.21
r14 = -12.379
d14 = 1 Nd14 = 1.84666 νd14 = 23.78
r15 = 33.143 (Aspherical surface)
d15 = D15
r16 = 75.485
d16 = 0.6 Nd16 = 1.48749 νd16 = 70.23
r17 = 9.793
d17 = D17
r18 = 9.468 (Aspherical surface)
d18 = 1.8 Nd18 = 1.7432 νd18 = 49.34
r19 = 110.758
d19 = D19
r20 = ∞
d20 = 1.9 Nd20 = 1.54771 νd20 = 62.84
r21 = ∞
d21 = 0.8
r22 = ∞
d22 = 0.75 Nd22 = 1.51633 νd22 = 64.14
r23 = ∞
d23 = D23

Aspherical coefficient fifth surface
k = 0
A4 = 1.75267E-05
A6 = 3.00970E-07
A8 = 0
7th page
k = 0
A4 = 8.41987E-05
A6 = 2.81257E-06
A8 = -4.40220E-07
9th page
k = 0
A4 = -3.40594E-04
A6 = 1.28078E-05
A8 = -1.47015E-06
13th page
k = 0
A4 = 9.29393E-05
A6 = 2.27583E-06
A8 = 2.74322E-08
15th page
k = 0
A4 = 8.13829E-04
A6 = 7.34253E-06
A8 = 1.33131E-06
18th page
k = 0
A4 = -8.92455E-05
A6 = 6.36509E-06
A8 = -1.97541E-07

Zoom data
When D0 (distance from the object to the first surface) is ∞
Wide-angle end Middle Telephoto end
Focal length 6.004 13.7 17.996
FNO. 2.88 4.93 6.03
D6 0.8 7.2 8.34
D11 8.93 2.53 1.39
D12 11.51 4.24 1.2
D15 1.2 11.76 14.36
D17 1.55 2.58 3.35
D19 5.15 0.83 0.5
D23 1.36 1.36 1.36

  FIG. 5 is a sectional view along the optical axis showing an optical configuration at the time of focusing on an object point at infinity at the wide-angle end of the zoom lens according to Example 3 of the present invention.

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

  As shown in FIG. 5, the zoom lens of Example 3 includes, in order from the object side, the first lens group G1, the second lens group G2, the aperture stop S, the third lens group G3, and the fourth lens group. G4 and the fifth lens group G5 are included. In the figure, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

  The first lens group G1 includes a negative meniscus lens L111 having a convex surface directed toward the object side, a prism L112, and a biconvex lens L113, and has a positive refractive power as a whole.

  The second lens group G2 includes a cemented lens of a positive meniscus lens L121 having a convex surface directed toward the image side and a biconcave lens L122, and a positive meniscus lens L123 having a convex surface directed toward the object side, and has a negative refracting power as a whole. have. The positive meniscus lens L121 having a convex surface facing the image side is a lens having a thin heart thickness.

  The third lens group G3 is composed of a cemented lens made up of a biconvex lens L131 and a biconcave lens L132, and has a positive refractive power as a whole.

  The fourth lens group G4 includes a negative meniscus lens L141 having a convex surface directed toward the object side, and has a negative refracting power as a whole.

  The fifth lens group G5 includes a biconvex lens L142, and has a positive refractive power as a whole.

  When zooming from the wide-angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 is moved to the image side, the aperture stop S is fixed, and the third lens group G3 is moved to the object side. The fourth lens group G4 once moves to the image side, then moves to the object side, and moves to the image side of the fifth lens group G5.

  The aspherical surfaces are the object side surface of the biconvex lens L113 in the first lens group G1, the object side surface of the positive meniscus lens L121 with the convex surface facing the image side in the second lens group G2, and the image side of the biconcave lens L122. On the object side surface of the biconvex lens L131 in the third lens group G3, the image side surface of the biconcave lens L132, and the object side surface of the biconvex lens L142 in the fifth lens group G5.

Next, numerical data of this embodiment will be listed.
Numerical data 3
r1 = 26.034
d1 = 1 Nd1 = 1.8061 νd1 = 40.92
r2 = 10.008
d2 = 2.9
r3 = ∞
d3 = 12 Nd3 = 1.8061 νd3 = 40.92
r4 = ∞
d4 = 0.3
r5 = 31.427 (Aspherical surface)
d5 = 3.54 Nd5 = 1.741 νd5 = 52.64
r6 = -28.242
d6 = D6
r7 = -450.644 (Aspherical surface)
d7 = 0.1 Nd7 = 1.51824 νd7 = 12.85
r8 = -90.128
d8 = 0.7 Nd8 = 1.8044 νd8 = 39.59
r9 = 6.379 (aspherical surface)
d9 = 0.7
r10 = 8.418
d10 = 2.2 Nd10 = 1.7552 νd10 = 27.51
r11 = 53.205
d11 = D11
r12 = aperture
d12 = D12
r13 = 7.744 (aspherical surface)
d13 = 5.68 Nd13 = 1.6935 νd13 = 53.21
r14 = -11.578
d14 = 1 Nd14 = 1.84666 νd14 = 23.78
r15 = 29.590 (Aspherical surface)
d15 = D15
r16 = 50.592
d16 = 0.6 Nd16 = 1.48749 νd16 = 70.23
r17 = 9.911
d17 = D17
r18 = 10.239 (aspherical surface)
d18 = 1.8 Nd18 = 1.7432 νd18 = 49.34
r19 = -99.931
d19 = D19
r20 = ∞
d20 = 1.9 Nd20 = 1.54771 νd20 = 62.84
r21 = ∞
d21 = 0.8
r22 = ∞
d22 = 0.75 Nd22 = 1.51633 νd22 = 64.14
r23 = ∞
d23 = D23

Aspherical coefficient fifth surface
k = 0
A4 = 1.17810E-05
A6 = 1.82657E-07
A8 = 0
7th page
k = 0
A4 = -4.42069E-04
A6 = 3.26119E-05
A8 = -6.84627E-07
9th page
k = 0
A4 = -6.04325E-04
A6 = 2.50939E-05
A8 = -7.15313E-07
13th page
k = 0
A4 = 1.11989E-04
A6 = 2.08910E-06
A8 = 6.26649E-08
15th page
k = 0
A4 = 7.60266E-04
A6 = 7.40588E-06
A8 = 1.27917E-06
18th page
k = 0
A4 = -1.02638E-04
A6 = 9.54050E-06
A8 = -2.57130E-07

Zoom data
When D0 (distance from the object to the first surface) is ∞
Wide-angle end Middle Telephoto end
Focal length 6.005 13.699 17.987
FNO. 2.88 4.93 6.03
D6 0.8 6.95 8.31
D11 8.88 2.73 1.37
D12 11.72 4.04 1.18
D15 1.21 12.15 14.34
D17 1.63 2.17 3.45
D19 4.93 1.12 0.52
D23 1.36 1.36 1.36

  FIG. 7 is a cross-sectional view along the optical axis showing an optical configuration at the time of focusing on an object point at infinity at the wide-angle end of a zoom lens according to Example 4 of the present invention.

  FIG. 8 is a diagram illustrating spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 4 is focused on an object point at infinity, where (a) is the wide-angle end, (b) is the middle, (c) shows the state at the telephoto end.

  As shown in FIG. 7, the zoom lens of Example 4 includes, in order from the object side, the first lens group G1, the second lens group G2, the aperture stop S, the third lens group G3, and the fourth lens group. G4 and the fifth lens group G5 are included. In the figure, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

  The first lens group G1 includes a negative meniscus lens L111 having a convex surface directed toward the object side, a prism L112, and a biconvex lens L113, and has a positive refractive power as a whole.

  The second lens group G2 includes a cemented lens of a positive meniscus lens L121 having a convex surface directed toward the image side and a biconcave lens L122, and a positive meniscus lens L123 having a convex surface directed toward the object side, and has a negative refracting power as a whole. have. The positive meniscus lens L121 having a convex surface facing the image side is a lens having a thin heart thickness.

  The third lens group G3 is composed of a cemented lens made up of a biconvex lens L131 and a biconcave lens L132, and has a positive refractive power as a whole.

  The fourth lens group G4 includes a negative meniscus lens L141 having a convex surface directed toward the object side, and has a negative refracting power as a whole.

  The fifth lens group G5 includes a biconvex lens L142, and has a positive refractive power as a whole.

  When zooming from the wide-angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 is moved to the image side, the aperture stop S is fixed, and the third lens group G3 is moved to the object side. The fourth lens group G4 once moves to the image side, then moves to the object side, and moves to the image side of the fifth lens group G5.

  The aspherical surfaces are the object side surface of the biconvex lens L113 in the first lens group G1, the object side surface of the positive meniscus lens L121 with the convex surface facing the image side in the second lens group G2, and the image side of the biconcave lens L122. On the object side surface of the biconvex lens L131 in the third lens group G3, the image side surface of the biconcave lens L132, and the object side surface of the biconvex lens L142 in the fifth lens group G5.

Next, numerical data of this embodiment will be listed.
Numerical data 4
r1 = 26.322
d1 = 1 Nd1 = 1.8061 νd1 = 40.92
r2 = 10.013
d2 = 2.9
r3 = ∞
d3 = 12 Nd3 = 1.8061 νd3 = 40.92
r4 = ∞
d4 = 0.3
r5 = 29.452 (Aspherical surface)
d5 = 3.54 Nd5 = 1.741 νd5 = 52.64
r6 = -27.694
d6 = D6
r7 = -531.522 (Aspherical surface)
d7 = 0.1 Nd7 = 1.54856 νd7 = 7.04
r8 = -106.303
d8 = 0.7 Nd8 = 1.801 νd8 = 34.97
r9 = 5.870 (aspherical surface)
d9 = 0.7
r10 = 7.8
d10 = 2.2 Nd10 = 1.7552 νd10 = 27.51
r11 = 53.964
d11 = D11
r12 = aperture
d12 = D12
r13 = 7.924 (Aspherical surface)
d13 = 5.76 Nd13 = 1.6935 νd13 = 53.21
r14 = -12.116
d14 = 1 Nd14 = 1.84666 νd14 = 23.78
r15 = 29.891 (aspherical surface)
d15 = D15
r16 = 39.978
d16 = 0.6 Nd16 = 1.48749 νd16 = 70.23
r17 = 9.323
d17 = D17
r18 = 9.450 (Aspherical surface)
d18 = 1.8 Nd18 = 1.7432 νd18 = 49.34
r19 = -189.465
d19 = D19
r20 = ∞
d20 = 1.9 Nd20 = 1.54771 νd20 = 62.84
r21 = ∞
d21 = 0.8
r22 = ∞
d22 = 0.75 Nd22 = 1.51633 νd22 = 64.14
r23 = ∞
d23 = D23

Aspherical coefficient fifth surface
k = 0
A4 = 9.75478E-06
A6 = 1.51579E-07
A8 = 0
7th page
k = 0
A4 = -1.95112E-04
A6 = 1.43936E-05
A8 = -2.98225E-07
9th page
k = 0
A4 = -5.10533E-04
A6 = 1.21310E-05
A8 = -6.59060E-07
13th page
k = 0
A4 = 1.12806E-04
A6 = 1.80736E-06
A8 = 4.78959E-08
15th page
k = 0
A4 = 7.17631E-04
A6 = 7.87011E-06
A8 = 9.76118E-07
18th page
k = 0
A4 = -9.54875E-05
A6 = 7.46371E-06
A8 = -2.00942E-07

Zoom data
When D0 (distance from the object to the first surface) is ∞
Wide-angle end Middle Telephoto end
Focal length 5.995 13.694 17.985
FNO. 2.86 4.93 6.05
D6 0.79 6.91 8.34
D11 8.92 2.81 1.37
D12 11.67 3.89 1.18
D15 1.21 12.04 14.24
D17 1.53 2.07 3.35
D19 4.89 1.29 0.52
D23 1.36 1.37 1.37

  FIG. 9 is a cross-sectional view along the optical axis showing the optical configuration when focusing on an object point at infinity at the wide-angle end of a zoom lens according to Example 5 of the present invention.

  FIG. 10 is a diagram illustrating spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 5 is focused on an object point at infinity, where (a) is a wide angle end, (b) is an intermediate position, (c) shows the state at the telephoto end.

  As shown in FIG. 9, the zoom lens of Example 5 includes, in order from the object side, a first lens group G1, a second lens group G2, an aperture stop S, a third lens group G3, and a fourth lens group. G4 and the fifth lens group G5 are included. In the figure, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

  The first lens group G1 includes a negative meniscus lens L111 having a convex surface directed toward the object side, a prism L112, and a biconvex lens L113, and has a positive refractive power as a whole.

  The second lens group G2 includes a cemented lens of a positive meniscus lens L121 having a convex surface directed toward the image side and a biconcave lens L122, and a positive meniscus lens L123 having a convex surface directed toward the object side, and has a negative refracting power as a whole. have. The positive meniscus lens L121 having a convex surface facing the image side is a lens having a thin heart thickness.

  The third lens group G3 is composed of a cemented lens made up of a biconvex lens L131 and a biconcave lens L132, and has a positive refractive power as a whole.

  The fourth lens group G4 includes a negative meniscus lens L141 having a convex surface directed toward the object side, and has a negative refracting power as a whole.

  The fifth lens group G5 includes a biconvex lens L142, and has a positive refractive power as a whole.

  When zooming from the wide-angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 is moved to the image side, the aperture stop S is fixed, and the third lens group G3 is moved to the object side. The fourth lens group G4 once moves to the image side, then moves to the object side, and moves to the image side of the fifth lens group G5.

  The aspherical surfaces are the object side surface of the biconvex lens L113 in the first lens group G1, the object side surface of the positive meniscus lens L121 with the convex surface facing the image side in the second lens group G2, and the image side of the biconcave lens L122. On the object side surface of the biconvex lens L131 in the third lens group G3, the image side surface of the biconcave lens L132, and the object side surface of the biconvex lens L142 in the fifth lens group G5.

Next, numerical data of this embodiment will be listed.
Numerical data 5
r1 = 22.26
d1 = 1 Nd1 = 1.8061 νd1 = 40.92
r2 = 8.728
d2 = 3.48
r3 = ∞
d3 = 12 Nd3 = 1.8061 νd3 = 40.92
r4 = ∞
d4 = 0.3
r5 = 30.986 (aspherical surface)
d5 = 3.54 Nd5 = 1.741 νd5 = 52.64
r6 = -27.99
d6 = D6
r7 = -115.268 (Aspherical surface)
d7 = 0.1 Nd7 = 1.65228 νd7 = 12.75
r8 = -126.689
d8 = 0.7 Nd8 = 1.8044 νd8 = 39.59
r9 = 5.968 (Aspherical surface)
d9 = 0.7
r10 = 8.311
d10 = 2.2 Nd10 = 1.7552 νd10 = 27.51
r11 = 176.709
d11 = D11
r12 = aperture d12 = D12
r13 = 7.790 (aspherical surface)
d13 = 6.26 Nd13 = 1.6935 νd13 = 53.21
r14 = -11.462
d14 = 1 Nd14 = 1.84666 νd14 = 23.78
r15 = 28.003 (Aspherical surface)
d15 = D15
r16 = 15.819
d16 = 0.6 Nd16 = 1.48749 νd16 = 70.23
r17 = 8.139
d17 = D17
r18 = 11.145 (aspherical surface)
d18 = 1.8 Nd18 = 1.7432 νd18 = 49.34
r19 = -741.85
d19 = D19
r20 = ∞
d20 = 1.9 Nd20 = 1.54771 νd20 = 62.84
r21 = ∞
d21 = 0.8
r22 = ∞
d22 = 0.75 Nd22 = 1.51633 νd22 = 64.14
r23 = ∞
d23 = D23

Aspherical coefficient fifth surface
k = 0
A4 = 2.56867E-05
A6 = 2.52676E-07
A8 = 0
7th page
k = 0
A4 = -1.22696E-04
A6 = 8.55567E-06
A8 = -7.67236E-08
9th page
k = 0
A4 = -5.12267E-04
A6 = 4.37980E-06
A8 = -3.04805E-07
13th page
k = 0
A4 = 6.62474E-05
A6 = 1.59411E-06
A8 = 2.28358E-08
15th page
k = 0
A4 = 6.81156E-04
A6 = 1.15567E-05
A8 = 8.59263E-07
18th page
k = 0
A4 = -5.99348E-05
A6 = 9.65602E-06
A8 = -1.88588E-07

Zoom data
When D0 (distance from the object to the first surface) is ∞
Wide-angle end Middle Telephoto end
Focal length 6.1 13.42 17.995
FNO. 3.27 5.28 6.49
D6 1.53 8.13 9.28
D11 11.01 2.98 0.41
D12 7.5 2.21 0.4
D15 0.9 11.71 14.54
D17 1.54 2.08 3.46
D19 4.85 1.27 0.39
D23 1.36 1.36 1.36

  FIG. 11 is a cross-sectional view along the optical axis showing an optical configuration at the time of focusing on an object point at infinity at the wide-angle end of a zoom lens according to Example 6 of the present invention.

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

  As shown in FIG. 11, the zoom lens of Example 6 includes, in order from the object side, a first lens group G1, a second lens group G2, an aperture stop S, a third lens group G3, and a fourth lens group. G4 and the fifth lens group G5 are included. In the figure, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

  The first lens group G1 includes a negative meniscus lens L111 having a convex surface directed toward the object side, a prism L112, and a biconvex lens L113, and has a positive refractive power as a whole.

  The second lens group G2 includes a cemented lens of a negative meniscus lens L121 having a convex surface directed toward the image side and a biconcave lens L122, and a biconvex lens L123, and has a negative refracting power as a whole. The negative meniscus lens L121 having a convex surface facing the image side is a lens having a thin heart thickness.

  The third lens group G3 is composed of a cemented lens made up of a biconvex lens L131 and a biconcave lens L132, and has a positive refractive power as a whole.

  The fourth lens group G4 includes a negative meniscus lens L141 having a convex surface directed toward the object side, and has a negative refracting power as a whole.

  The fifth lens group G5 includes a biconvex lens L142, and has a positive refractive power as a whole.

  When zooming from the wide-angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 is moved to the image side, the aperture stop S is fixed, and the third lens group G3 is moved to the object side. The fourth lens group G4 once moves to the image side, then moves to the object side, and moves to the image side of the fifth lens group G5.

  The aspherical surface is the object side surface of the biconvex lens L113 in the first lens group G1, the object side surface of the negative meniscus lens L121 with the convex surface facing the image side in the second lens group G2, and the image side of the biconcave lens L122. On the object side surface of the biconvex lens L131 in the third lens group G3, the image side surface of the biconcave lens L132, and the object side surface of the biconvex lens L142 in the fifth lens group G5.

Next, numerical data of this embodiment will be listed.
Numerical data 6
r1 = 22.209
d1 = 1 Nd1 = 1.8061 νd1 = 40.92
r2 = 8.697
d2 = 3.18
r3 = ∞
d3 = 12 Nd3 = 1.8061 νd3 = 40.92
r4 = ∞
d4 = 0.3
r5 = 27.453 (Aspherical surface)
d5 = 3.54 Nd5 = 1.741 νd5 = 52.64
r6 = -31.911
d6 = D6
r7 = -75.168 (Aspherical surface)
d7 = 0.1 Nd7 = 1.59885 νd7 = 6.52
r8 = -83.815
d8 = 0.7 Nd8 = 1.8044 νd8 = 39.59
r9 = 5.799 (aspherical surface)
d9 = 0.7
r10 = 8.228
d10 = 2.2 Nd10 = 1.7552 νd10 = 27.51
r11 = −407.116
d11 = D11
r12 = aperture d12 = D12
r13 = 7.739 (aspherical surface)
d13 = 6.54 Nd13 = 1.6935 νd13 = 53.21
r14 = -10.834
d14 = 1 Nd14 = 1.84666 νd14 = 23.78
r15 = 27.091 (Aspherical surface)
d15 = D15
r16 = 25.56
d16 = 0.6 Nd16 = 1.48749 νd16 = 70.23
r17 = 9.672
d17 = D17
r18 = 11.326 (Aspherical surface)
d18 = 1.8 Nd18 = 1.7432 νd18 = 49.34
r19 = -227.342
d19 = D19
r20 = ∞
d20 = 1.9 Nd20 = 1.54771 νd20 = 62.84
r21 = ∞
d21 = 0.8
r22 = ∞
d22 = 0.75 Nd22 = 1.51633 νd22 = 64.14
r23 = ∞
d23 = D23

Aspherical coefficient fifth surface
k = 0
A4 = 2.84829E-05
A6 = 2.98793E-07
A8 = 0
7th page
k = 0
A4 = -2.83811E-05
A6 = 1.81353E-06
A8 = 1.62198E-08
9th page
k = 0
A4 = -4.89938E-04
A6 = -2.91999E-06
A8 = -3.73006E-07
13th page
k = 0
A4 = 5.58218E-05
A6 = 1.85250E-06
A8 = -3.45414E-09
15th page
k = 0
A4 = 6.90896E-04
A6 = 1.56789E-05
A8 = 7.47064E-07
18th page
k = 0
A4 = -8.76384E-05
A6 = 8.91453E-06
A8 = -1.89454E-07

Zoom data
When D0 (distance from the object to the first surface) is ∞
Wide-angle end Middle Telephoto end
Focal length 6.1 13.42 17.995
FNO. 3.4 5.52 6.68
D6 0.41 7.3 8.56
D11 11.8 3.71 0.48
D12 7.08 1.49 0.4
D15 1.1 11.71 14.56
D17 1.54 2.07 3.45
D19 4.85 1.28 0.4
D23 1.36 1.36 1.36

  FIG. 13 is a cross-sectional view along the optical axis showing an optical configuration at the time of focusing on an object point at infinity at the wide-angle end of a zoom lens according to Example 7 of the present invention.

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

  As shown in FIG. 13, the zoom lens according to the seventh exemplary embodiment includes, in order from the object side, the first lens group G1, the second lens group G2, the aperture stop S, the third lens group G3, and the fourth lens group. G4 and the fifth lens group G5 are included. In the figure, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

  The first lens group G1 includes a negative meniscus lens L111 having a convex surface directed toward the object side, a prism L112, and a biconvex lens L113, and has a positive refractive power as a whole.

  The second lens group G2 includes a cemented lens of a negative meniscus lens L121 having a convex surface directed toward the image side and a biconcave lens L122, and a biconvex lens L123, and has a negative refracting power as a whole. The negative meniscus lens L121 having a convex surface facing the image side is a lens having a thin heart thickness.

  The third lens group G3 is composed of a cemented lens made up of a biconvex lens L131 and a biconcave lens L132, and has a positive refractive power as a whole.

  The fourth lens group G4 includes a negative meniscus lens L141 having a convex surface directed toward the object side, and has a negative refracting power as a whole.

  The fifth lens group G5 includes a biconvex lens L142, and has a positive refractive power as a whole.

  When zooming from the wide-angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 is moved to the image side, the aperture stop S is fixed, and the third lens group G3 is moved to the object side. The fourth lens group G4 once moves to the image side, then moves to the object side, and moves to the image side of the fifth lens group G5.

  The aspherical surface is the object side surface of the biconvex lens L113 in the first lens group G1, the object side surface of the negative meniscus lens L121 with the convex surface facing the image side in the second lens group G2, and the image side of the biconcave lens L122. On the object side surface of the biconvex lens L131 in the third lens group G3, the image side surface of the biconcave lens L132, and the object side surface of the biconvex lens L142 in the fifth lens group G5.

  Next, numerical data of this embodiment will be listed.

Numerical data 7
r1 = 22.655
d1 = 1 Nd1 = 1.8061 νd1 = 40.92
r2 = 8.785
d2 = 3.24
r3 = ∞
d3 = 12 Nd3 = 1.8061 νd3 = 40.92
r4 = ∞
d4 = 0.3
r5 = 28.098 (Aspherical surface)
d5 = 3.54 Nd5 = 1.741 νd5 = 52.64
r6 = -33.03
d6 = D6
r7 = -73.397 (aspherical surface)
d7 = 0.1 Nd7 = 1.79525 νd7 = 9.95
r8 = -88.456
d8 = 0.7 Nd8 = 1.8044 νd8 = 39.59
r9 = 5.854 (aspherical surface)
d9 = 0.7
r10 = 8.306
d10 = 2.2 Nd10 = 1.7552 νd10 = 27.51
r11 = -244.362
d11 = D11
r12 = aperture d12 = D12
r13 = 7.717 (aspherical surface)
d13 = 6.62 Nd13 = 1.6935 νd13 = 53.21
r14 = -10.82
d14 = 1 Nd14 = 1.84666 νd14 = 23.78
r15 = 26.804 (aspherical surface)
d15 = D15
r16 = 38.158
d16 = 0.6 Nd16 = 1.48749 νd16 = 70.23
r17 = 10.759
d17 = D17
r18 = 11.628 (Aspherical surface)
d18 = 1.8 Nd18 = 1.7432 νd18 = 49.34
r19 = -136.914
d19 = D19
r20 = ∞
d20 = 1.9 Nd20 = 1.54771 νd20 = 62.84
r21 = ∞
d21 = 0.8
r22 = ∞
d22 = 0.75 Nd22 = 1.51633 νd22 = 64.14
r23 = ∞
d23 = D23

Aspherical coefficient fifth surface
k = 0
A4 = 2.99107E-05
A6 = 2.84593E-07
A8 = 0
7th page
k = 0
A4 = -1.93689E-05
A6 = 1.33119E-06
A8 = 2.74251E-08
9th page
k = 0
A4 = -4.76470E-04
A6 = -3.16782E-06
A8 = -3.04345E-07
13th page
k = 0
A4 = 5.07612E-05
A6 = 1.80052E-06
A8 = -5.82045E-09
15th page
k = 0
A4 = 6.95232E-04
A6 = 1.61806E-05
A8 = 7.52248E-07
18th page
k = 0
A4 = -9.66932E-05
A6 = 8.24751E-06
A8 = -1.78280E-07

Zoom data
When D0 (distance from the object to the first surface) is ∞
Wide-angle end Middle Telephoto end
Focal length 6.1 13.414 17.987
FNO. 3.46 5.61 6.76
D6 0.64 7.62 8.96
D11 12.56 3.88 0.5
D12 6.75 1.31 0.4
D15 1.16 11.69 14.54
D17 1.54 2.07 3.45
D19 4.85 1.28 0.4
D23 1.36 1.36 1.36

  FIG. 15 is a cross-sectional view along the optical axis showing an optical configuration at the time of focusing on an object point at infinity at the wide-angle end of a zoom lens according to Example 8 of the present invention.

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

  As shown in FIG. 15, the zoom lens of Example 8 includes, in order from the object side, the first lens group G1, the second lens group G2, the aperture stop S, the third lens group G3, and the fourth lens group. G4 and the fifth lens group G5 are included. In the figure, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

  The first lens group G1 includes a negative meniscus lens L111 having a convex surface directed toward the object side, a prism L112, and a biconvex lens L113, and has a positive refractive power as a whole.

  The second lens group G2 includes a cemented lens of a negative meniscus lens L121 having a convex surface directed toward the image side and a biconcave lens L122, and a biconvex lens L123, and has a negative refracting power as a whole. The negative meniscus lens L121 having a convex surface facing the image side is a lens having a thin heart thickness.

  The third lens group G3 is composed of a cemented lens made up of a biconvex lens L131 and a biconcave lens L132, and has a positive refractive power as a whole.

  The fourth lens group G4 includes a negative meniscus lens L141 having a convex surface directed toward the object side, and has a negative refracting power as a whole.

  The fifth lens group G5 includes a positive biconvex lens L142, and has a positive refractive power as a whole.

  When zooming from the wide-angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 is moved to the image side, the aperture stop S is fixed, and the third lens group G3 is moved to the object side. The fourth lens group G4 once moves to the image side, then moves to the object side, and moves to the image side of the fifth lens group G5.

  The aspherical surface is the object side surface of the biconvex lens L113 in the first lens group G1, the object side surface of the negative meniscus lens L121 with the convex surface facing the image side in the second lens group G2, and the image side of the biconcave lens L122. On the object side surface of the biconvex lens L131 in the third lens group G3, the image side surface of the biconcave lens L132, and the object side surface of the biconvex lens L142 in the fifth lens group G5.

Next, numerical data of this embodiment will be listed.
Numerical data 8
r1 = 22.918
d1 = 1 Nd1 = 1.8061 νd1 = 40.92
r2 = 8.816
d2 = 3.29
r3 = ∞
d3 = 12 Nd3 = 1.8061 νd3 = 40.92
r4 = ∞
d4 = 0.3
r5 = 28.613 (Aspherical surface)
d5 = 3.54 Nd5 = 1.741 νd5 = 52.64
r6 = -32.117
d6 = D6
r7 = -65.160 (Aspherical surface)
d7 = 0.1 Nd7 = 1.9712 νd7 = 12.88
r8 = -81.741
d8 = 0.7 Nd8 = 1.8044 νd8 = 39.59
r9 = 5.883 (aspherical surface)
d9 = 0.7
r10 = 8.372
d10 = 2.2 Nd10 = 1.7552 νd10 = 27.51
r11 = -174.482
d11 = D11
r12 = aperture d12 = D12
r13 = 7.706 (aspherical surface)
d13 = 6.66 Nd13 = 1.6935 νd13 = 53.21
r14 = -10.835
d14 = 1 Nd14 = 1.84666 νd14 = 23.78
r15 = 26.735 (Aspherical surface)
d15 = D15
r16 = 45.204
d16 = 0.6 Nd16 = 1.48749 νd16 = 70.23
r17 = 11.103
d17 = D17
r18 = 11.758 (aspherical surface)
d18 = 1.8 Nd18 = 1.7432 νd18 = 49.34
r19 = -117.417
d19 = D19
r20 = ∞
d20 = 1.9 Nd20 = 1.54771 νd20 = 62.84
r21 = ∞
d21 = 0.8
r22 = ∞
d22 = 0.75 Nd22 = 1.51633 νd22 = 64.14
r23 = ∞
d23 = D23

Aspherical coefficient fifth surface
k = 0
A4 = 2.87784E-05
A6 = 2.66348E-07
A8 = 0
7th page
k = 0
A4 = -1.38102E-05
A6 = 1.38465E-06
A8 = 2.55312E-08
9th page
k = 0
A4 = -4.75969E-04
A6 = -3.07587E-06
A8 = -2.61770E-07
13th page
k = 0
A4 = 4.93597E-05
A6 = 1.70693E-06
A8 = -4.25329E-09
15th page
k = 0
A4 = 7.00683E-04
A6 = 1.60807E-05
A8 = 7.69068E-07
18th page
k = 0
A4 = -9.75190E-05
A6 = 7.97130E-06
A8 = -1.72283E-07

Zoom data
When D0 (distance from the object to the first surface) is ∞
Wide-angle end Middle Telephoto end
Focal length 6.1 13.42 17.995
FNO. 3.5 5.64 6.81
D6 1.05 7.71 9.02
D11 13.1 3.96 0.63
D12 6.34 1.25 0.33
D15 1.21 11.71 14.56
D17 1.54 2.07 3.45
D19 4.85 1.28 0.4
D23 1.36 1.36 1.36

  FIG. 17 is a cross-sectional view along the optical axis showing an optical configuration at the time of focusing on an object point at infinity at the wide-angle end of a zoom lens according to Example 9 of the present invention.

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

  As shown in FIG. 17, the zoom lens according to the ninth embodiment includes, in order from the object side, the first lens group G1, the second lens group G2, the aperture stop S, the third lens group G3, and the fourth lens group. G4 and the fifth lens group G5 are included. In the figure, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

  The first lens group G1 includes a negative meniscus lens L111 having a convex surface directed toward the object side, a prism L112, and a biconvex lens L113, and has a positive refractive power as a whole.

  The second lens group G2 includes a cemented lens of a negative meniscus lens L121 having a convex surface directed toward the image side and a biconcave lens L122, and a biconvex lens L123, and has a negative refracting power as a whole. The negative meniscus lens L121 having a convex surface facing the image side is a lens having a thin heart thickness.

  The third lens group G3 is composed of a cemented lens made up of a biconvex lens L131 and a biconcave lens L132, and has a positive refractive power as a whole.

  The fourth lens group G4 includes a negative meniscus lens L141 having a convex surface directed toward the object side, and has a negative refracting power as a whole.

  The fifth lens group G5 includes a biconvex lens L142, and has a positive refractive power as a whole.

  When zooming from the wide-angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 is moved to the image side, the aperture stop S is fixed, and the third lens group G3 is moved to the object side. The fourth lens group G4 once moves to the image side, then moves to the object side, and moves to the image side of the fifth lens group G5.

  The aspherical surface is the object side surface of the biconvex lens L113 in the first lens group G1, the object side surface of the negative meniscus lens L121 with the convex surface facing the image side in the second lens group G2, and the image side of the biconcave lens L122. On the object side surface of the biconvex lens L131 in the third lens group G3, the image side surface of the biconcave lens L132, and the object side surface of the biconvex lens L142 in the fifth lens group G5.

Next, numerical data of this embodiment will be listed.
Numerical data 9
r1 = 22.569
d1 = 1 Nd1 = 1.8061 νd1 = 40.92
r2 = 8.775
d2 = 3.24
r3 = ∞
d3 = 12 Nd3 = 1.8061 νd3 = 40.92
r4 = ∞
d4 = 0.3
r5 = 28.397 (Aspherical surface)
d5 = 3.54 Nd5 = 1.741 νd5 = 52.64
r6 = -30.066
d6 = D6
r7 = -68.946 (aspherical surface)
d7 = 0.1 Nd7 = 2.0512 νd7 = 6.28
r8 = -72.063
d8 = 0.7 Nd8 = 1.8044 νd8 = 39.59
r9 = 5.835 (aspherical surface)
d9 = 0.7
r10 = 8.288
d10 = 2.2 Nd10 = 1.7552 νd10 = 27.51
r11 = -350.22
d11 = D11
r12 = aperture d12 = D12
r13 = 7.762 (aspherical surface)
d13 = 6.44 Nd13 = 1.6935 νd13 = 53.21
r14 = -10.924
d14 = 1 Nd14 = 1.84666 νd14 = 23.78
r15 = 27.463 (aspherical surface)
d15 = D15
r16 = 18.162
d16 = 0.6 Nd16 = 1.48749 νd16 = 70.23
r17 = 8.571
d17 = D17
r18 = 11.048 (aspherical surface)
d18 = 1.8 Nd18 = 1.7432 νd18 = 49.34
r19 = -683.995
d19 = D19
r20 = ∞
d20 = 1.9 Nd20 = 1.54771 νd20 = 62.84
r21 = ∞
d21 = 0.8
r22 = ∞
d22 = 0.75 Nd22 = 1.51633 νd22 = 64.14
r23 = ∞
d23 = D23

Aspherical coefficient fifth surface
k = 0
A4 = 2.65390E-05
A6 = 2.574957E-07
A8 = 0
7th page
k = 0
A4 = -3.03094E-05
A6 = 2.50533E-06
A8 = -2.39841E-08
9th page
k = 0
A4 = -5.10845E-04
A6 = 1.79630E-07
A8 = -4.24947E-07
13th page
k = 0
A4 = 6.06181E-05
A6 = 1.82150E-06
A8 = 5.55091E-09
15th page
k = 0
A4 = 6.87453E-04
A6 = 1.41002E-05
A8 = 7.95382E-07
18th page
k = 0
A4 = -7.29457E-05
A6 = 9.71422E-06
A8 = -2.00168E-07

Zoom data
When D0 (distance from the object to the first surface) is ∞
Wide-angle end Middle Telephoto end
Focal length 6.1 13.42 17.997
FNO. 3.33 5.43 6.58
D6 0.81 7.75 9.07
D11 10.99 3.5 0.4
D12 7.32 1.62 0.4
D15 0.99 11.73 14.54
D17 1.54 2.07 3.45
D19 4.85 1.28 0.4
D23 1.36 1.36 1.36

  FIG. 19 is a cross-sectional view along the optical axis showing an optical configuration at the time of focusing on an object point at infinity at the wide-angle end of the zoom lens according to Example 10 of the present invention.

  FIG. 20 is a diagram illustrating spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 10 is focused on an object point at infinity, where (a) is a wide-angle end, (b) is an intermediate position, (c) shows the state at the telephoto end.

  As shown in FIG. 19, the zoom lens according to the tenth embodiment includes, in order from the object side, the first lens group G1, the second lens group G2, the aperture stop S, the third lens group G3, and the fourth lens group. G4. In the figure, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

  The first lens group G1 is a cemented lens of a negative meniscus lens L211 having a convex surface facing the object side and a positive meniscus lens L212 having a convex surface facing the object side, and a cemented lens of a prism L213, a biconvex lens L214, and a biconcave lens L215. It has a negative refractive power as a whole.

  The second lens group G2 includes a cemented lens which is formed by a biconvex lens L221 and a negative meniscus lens L222 having a convex surface directed toward the image side, and has a positive refractive power as a whole.

  The third lens group G3 includes a cemented lens which is formed by a biconcave lens L231 and a positive meniscus lens L232 having a convex surface directed toward the object side, and has a negative refracting power as a whole.

  The fourth lens group G4 includes a cemented lens which is formed by a biconvex lens L241 and a negative meniscus lens L242 having a concave surface directed toward the object side, and has a positive refracting power as a whole.

  When zooming from the wide-angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 is moved to the object side, the aperture stop S is fixed, and the third lens group G3 is moved to the image side. Then, the fourth lens group G4 moves to the image side.

  The aspheric surfaces are the image side surface of the positive meniscus lens L212 having a convex surface facing the object side in the first lens group G1, the object side surface of the biconvex lens L214, and the object side of the biconvex lens L221 in the second lens group G2. On the object side surface of the biconvex lens L241 in the fourth lens group G4.

Next, numerical data of this embodiment will be listed.
Numerical data 10
r1 = 47.465
d1 = 1.1 Nd1 = 1.7432 νd1 = 49.34
r2 = 10.5
d2 = 0.35 Nd2 = 1.41244 νd2 = 12.42
r3 = 10.870 (Aspherical surface)
d3 = 3
r4 = ∞
d4 = 12.5 Nd4 = 1.8061 νd4 = 40.92
r5 = ∞
d5 = 0.4
r6 = 37.541 (Aspherical surface)
d6 = 2.2 Nd6 = 1.8061 νd6 = 40.92
r7 = -15.157
d7 = 0.7 Nd7 = 1.51742 νd7 = 52.43
r8 = 14.284
d8 = D8
r9 = 15.765 (Aspherical surface)
d9 = 3.5 Nd9 = 1.7432 νd9 = 49.34
r10 = -13
d10 = 0.7 Nd10 = 1.84666 νd10 = 23.78
r11 = -49.098
d11 = D11
r12 = aperture
d12 = D12
r13 = -12.613
d13 = 0.7 Nd13 = 1.51823 νd13 = 58.9
r14 = 8.154
d14 = 1.6 Nd14 = 1.8061 νd14 = 40.92
r15 = 23.649
d15 = D15
r16 = 12.829 (aspherical surface)
d16 = 3.5 Nd16 = 1.7432 νd16 = 49.34
r17 = -6
d17 = 0.7 Nd17 = 1.84666 νd17 = 23.78
r18 = -15.292
d18 = D18
r19 = ∞
d19 = 1.44 Nd19 = 1.54771 νd19 = 62.84
r20 = ∞
d20 = 0.8
r21 = ∞
d21 = 0.6 Nd21 = 1.51633 νd21 = 64.14
r22 = ∞
d22 = D22

Aspheric coefficient third surface
k = 0
A4 = 3.50409E-05
A6 = -6.55294E-07
A8 = 0
6th page
k = 0
A4 = 2.65545E-05
A6 = -4.67758E-08
A8 = 0.000E + 00
9th page
k = 0
A4 = -1.42649E-05
A6 = 8.45141E-10
A8 = 0.000E + 00
16th page
k = 0
A4 = -1.91950E-04
A6 = 6.33278E-09
A8 = 0.000E + 00

Zoom data
When D0 (distance from the object to the first surface) is ∞
Wide-angle end Middle Telephoto end
Focal length 6.003 13.7 17.998
FNO. 2.86 3.43 3.76
D8 14.55 4.16 0.8
D11 1.6 11.99 15.35
D12 1.4 6.55 9.17
D15 6.27 4.39 3
D18 5.7 2.43 1.2
D22 1.36 1.36 1.36

  FIG. 21 is a cross-sectional view along the optical axis showing an optical configuration at the time of focusing on an object point at infinity at the wide-angle end of a zoom lens according to Example 11 of the present invention.

  FIG. 22 is a diagram illustrating spherical aberration, astigmatism, distortion, and lateral chromatic aberration when the zoom lens according to Example 11 is focused on an object point at infinity, where (a) is a wide angle end, (b) is an intermediate position, (c) shows the state at the telephoto end.

  As shown in FIG. 21, the zoom lens of Example 11 includes, in order from the object side, a first lens group G1, a second lens group G2, an aperture stop S, a third lens group G3, and a fourth lens group. G4. In the figure, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

  The first lens group G1 is a cemented lens of a negative meniscus lens L211 having a convex surface facing the object side and a negative meniscus lens L212 having a convex surface facing the object side, and a cemented lens of a prism L213, a biconvex lens L214, and a biconcave lens L215. It has a negative refractive power as a whole.

  The second lens group G2 includes a cemented lens which is formed by a biconvex lens L221 and a negative meniscus lens L222 having a convex surface directed toward the image side, and has a positive refractive power as a whole.

  The third lens group G3 includes a cemented lens which is formed by a biconcave lens L231 and a positive meniscus lens L232 having a convex surface directed toward the object side, and has a negative refracting power as a whole.

  The fourth lens group G4 includes a cemented lens which is formed by a biconvex lens L241 and a negative meniscus lens L242 having a concave surface directed toward the object side, and has a positive refracting power as a whole.

  When zooming from the wide-angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 is moved to the object side, the aperture stop S is fixed, and the third lens group G3 is moved to the image side. Then, the fourth lens group G4 moves to the image side.

  The aspherical surfaces are the image side surface of the negative meniscus lens L212 having a convex surface facing the object side in the first lens group G1, the object side surface of the biconvex lens L214, and the object side of the biconvex lens L221 in the second lens group G2. On the object side surface of the biconvex lens L241 in the fourth lens group G4.

Next, numerical data of this embodiment will be listed.
Numerical data 11
r1 = 40.805
d1 = 1.1 Nd1 = 1.741 νd1 = 52.64
r2 = 10.5
d2 = 0.35 Nd2 = 1.42001 νd2 = 6.55
r3 = 9.747 (Aspherical surface)
d3 = 3.1
r4 = ∞
d4 = 12.5 Nd4 = 1.8061 νd4 = 40.92
r5 = ∞
d5 = 0.4
r6 = 36.922 (aspherical surface)
d6 = 2.5 Nd6 = 1.8044 νd6 = 39.59
r7 = -17
d7 = 0.7 Nd7 = 1.51742 νd7 = 52.43
r8 = 15.572
d8 = D8
r9 = 17.084 (aspherical surface)
d9 = 3.5 Nd9 = 1.744 νd9 = 44.78
r10 = -13
d10 = 0.7 Nd10 = 1.84666 νd10 = 23.78
r11 = -43.272
d11 = D11
r12 = aperture
d12 = D12
r13 = -14.083
d13 = 0.7 Nd13 = 1.51633 νd13 = 64.14
r14 = 7.851
d14 = 1.6 Nd14 = 1.8061 νd14 = 40.92
r15 = 20.05
d15 = D15
r16 = 11.795 (Aspherical surface)
d16 = 3.5 Nd16 = 1.741 νd16 = 52.64
r17 = -6
d17 = 0.7 Nd17 = 1.84666 νd17 = 23.78
r18 = -17.498
d18 = D18
r19 = ∞
d19 = 1.44 Nd19 = 1.54771 νd19 = 62.84
r20 = ∞
d20 = 0.8
r21 = ∞
d21 = 0.6 Nd21 = 1.51633 νd21 = 64.14
r22 = ∞
d22 = D22

Aspheric coefficient third surface
k = 0
A4 = -2.71091E-06
A6 = -1.15364E-06
A8 = 0
6th page
k = 0
A4 = 2.35221E-05
A6 = 6.05500E-08
A8 = 0.000E + 00
9th page
k = 0
A4 = -9.17809E-06
A6 = -1.04149E-07
A8 = 0.000E + 00
16th page
k = 0
A4 = -1.87144E-04
A6 = 1.47652E-06
A8 = 0.000E + 00

Zoom data
When D0 (distance from the object to the first surface) is ∞
Wide-angle end Middle Telephoto end
Focal length 5.996 13.701 18.006
FNO. 2.86 3.43 3.76
D8 15.07 3.93 0.8
D11 1.61 12.75 15.88
D12 1.41 6.07 9.49
D15 6.44 4.89 3
D18 5.89 2.77 1.25
D22 1.36 1.36 1.36

  FIG. 23 is a cross-sectional view along the optical axis showing an optical configuration at the time of focusing on an object point at infinity at the wide-angle end of a zoom lens according to Example 12 of the present invention.

  FIG. 24 is a diagram illustrating spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 12 is focused on an object point at infinity, where (a) is a wide angle end, (b) is an intermediate view, (c) shows the state at the telephoto end.

  As shown in FIG. 23, in the zoom lens of Example 12, the first lens group G1, the second lens group G2, the aperture stop S, the third lens group G3, and the fourth lens group are sequentially arranged from the object side. G4. In the figure, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

  The first lens group G1 is a cemented lens of a negative meniscus lens L211 having a convex surface facing the object side and a negative meniscus lens L212 having a convex surface facing the object side, and a cemented lens of a prism L213, a biconvex lens L214, and a biconcave lens L215. It has a negative refractive power as a whole.

  The second lens group G2 includes a cemented lens which is formed by a biconvex lens L221 and a negative meniscus lens L222 having a convex surface directed toward the image side, and has a positive refractive power as a whole.

  The third lens group G3 includes a cemented lens which is formed by a biconcave lens L231 and a positive meniscus lens L232 having a convex surface directed toward the object side, and has a negative refracting power as a whole.

  The fourth lens group G4 includes a cemented lens which is formed by a biconvex lens L241 and a negative meniscus lens L242 having a concave surface directed toward the object side, and has a positive refracting power as a whole.

  When zooming from the wide-angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 is moved to the object side, the aperture stop S is fixed, and the third lens group G3 is moved to the image side. Then, the fourth lens group G4 moves to the image side.

  The aspherical surfaces are the image side surface of the negative meniscus lens L212 having a convex surface facing the object side in the first lens group G1, the object side surface of the biconvex lens L214, and the object side of the biconvex lens L221 in the second lens group G2. On the object side surface of the biconvex lens L241 in the fourth lens group G4.

Next, numerical data of this embodiment will be listed.
Numerical data 12
r1 = 35.33
d1 = 1.1 Nd1 = 1.741 νd1 = 52.64
r2 = 10.5
d2 = 0.35 Nd2 = 1.5184 νd2 = 12.85
r3 = 10.179 (aspherical surface)
d3 = 3
r4 = ∞
d4 = 12.5 Nd4 = 1.8061 νd4 = 40.92
r5 = ∞
d5 = 0.4
r6 = 83.310 (Aspherical surface)
d6 = 2.2 Nd6 = 1.8044 νd6 = 39.59
r7 = -15.779
d7 = 0.7 Nd7 = 1.51742 νd7 = 52.43
r8 = 17.653
d8 = D8
r9 = 15.957 (Aspherical surface)
d9 = 3.5 Nd9 = 1.7432 νd9 = 49.34
r10 = -13
d10 = 0.7 Nd10 = 1.84666 νd10 = 23.78
r11 = −38.464
d11 = D11
r12 = aperture
d12 = D12
r13 = -13.171
d13 = 0.7 Nd13 = 1.51633 νd13 = 64.14
r14 = 8.317
d14 = 1.6 Nd14 = 1.8061 νd14 = 40.92
r15 = 22.704
d15 = D15
r16 = 11.950 (aspherical surface)
d16 = 3.5 Nd16 = 1.7432 νd16 = 49.34
r17 = -6
d17 = 0.7 Nd17 = 1.84666 νd17 = 23.78
r18 = -17.693
d18 = D18
r19 = ∞
d19 = 1.44 Nd19 = 1.54771 νd19 = 62.84
r20 = ∞
d20 = 0.8
r21 = ∞
d21 = 0.6 Nd21 = 1.51633 νd21 = 64.14
r22 = ∞
d22 = D22

Aspheric coefficient third surface
k = 0
A4 = -3.96738E-06
A6 = -5.13102E-07
A8 = 0
6th page
k = 0
A4 = 2.05601E-05
A6 = 1.880893E-07
A8 = 0.000E + 00
9th page
k = 0
A4 = -1.68018E-05
A6 = -1.63553E-07
A8 = 0.000E + 00
16th page
k = 0
A4 = -1.70700E-04
A6 = 9.68010E-07
A8 = 0.000E + 00

Zoom data
When D0 (distance from the object to the first surface) is ∞
Wide-angle end Middle Telephoto end
Focal length 6.003 13.7 17.999
FNO. 2.86 3.43 3.76
D8 14.15 3.94 0.8
D11 1.6 11.81 14.95
D12 1.4 5.91 9.56
D15 6.85 5.36 3
D18 5.53 2.51 1.23
D22 1.36 1.36 1.36

  FIG. 25 is a cross-sectional view along the optical axis showing an optical configuration at the time of focusing on an object point at infinity at the wide-angle end of a zoom lens according to Example 13 of the present invention.

  FIG. 26 is a diagram illustrating spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 13 is focused on an object point at infinity, in which (a) is a wide angle end, (b) is an intermediate position, (c) shows the state at the telephoto end.

  As shown in FIG. 25, the zoom lens of Example 13 includes, in order from the object side, the first lens group G1, the second lens group G2, the aperture stop S, the third lens group G3, and the fourth lens group. G4. In the figure, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

  The first lens group G1 is a cemented lens of a negative meniscus lens L211 having a convex surface facing the object side and a positive meniscus lens L212 having a convex surface facing the object side, and a cemented lens of a prism L213, a biconvex lens L214, and a biconcave lens L215. It has a negative refractive power as a whole.

  The second lens group G2 includes a cemented lens which is formed by a biconvex lens L221 and a negative meniscus lens L222 having a convex surface directed toward the image side, and has a positive refractive power as a whole.

  The third lens group G3 includes a cemented lens which is formed by a biconcave lens L231 and a positive meniscus lens L232 having a convex surface directed toward the object side, and has a negative refracting power as a whole.

  The fourth lens group G4 includes a cemented lens which is formed by a biconvex lens L241 and a negative meniscus lens L242 having a concave surface directed toward the object side, and has a positive refracting power as a whole.

  When zooming from the wide-angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 is moved to the object side, the aperture stop S is fixed, and the third lens group G3 is moved to the image side. Then, the fourth lens group G4 moves to the image side.

  The aspheric surfaces are the image side surface of the positive meniscus lens L212 having a convex surface facing the object side in the first lens group G1, the object side surface of the biconvex lens L214, and the object side of the biconvex lens L221 in the second lens group G2. On the object side surface of the biconvex lens L241 in the fourth lens group G4.

Next, numerical data of this embodiment will be listed.
Numerical data 13
r1 = 34.024
d1 = 1.1 Nd1 = 1.8061 νd1 = 40.92
r2 = 10.5
d2 = 0.35 Nd2 = 1.54856 νd2 = 7.04
r3 = 10.855 (Aspherical surface)
d3 = 3
r4 = ∞
d4 = 12.5 Nd4 = 1.8061 νd4 = 40.92
r5 = ∞
d5 = 0.4
r6 = 42.711 (aspherical surface)
d6 = 2.2 Nd6 = 1.8061 νd6 = 40.92
r7 = -18.562
d7 = 0.7 Nd7 = 1.51742 νd7 = 52.43
r8 = 14.066
d8 = D8
r9 = 15.115 (Aspherical surface)
d9 = 3.5 Nd9 = 1.7432 νd9 = 49.34
r10 = -13
d10 = 0.7 Nd10 = 1.84666 νd10 = 23.78
r11 = -38.815
d11 = D11
r12 = aperture
d12 = D12
r13 = -12.644
d13 = 0.7 Nd13 = 1.51823 νd13 = 58.9
r14 = 8.31
d14 = 1.6 Nd14 = 1.8061 νd14 = 40.92
r15 = 24.052
d15 = D15
r16 = 13.981 (Aspherical surface)
d16 = 3.5 Nd16 = 1.7432 νd16 = 49.34
r17 = -6
d17 = 0.7 Nd17 = 1.84666 νd17 = 23.78
r18 = -14.538
d18 = D18
r19 = ∞
d19 = 1.44 Nd19 = 1.54771 νd19 = 62.84
r20 = ∞
d20 = 0.8
r21 = ∞
d21 = 0.6 Nd21 = 1.51633 νd21 = 64.14
r22 = ∞
d22 = D22

Aspheric coefficient third surface
k = 0
A4 = 4.16028E-05
A6 = -5.41690E-07
A8 = 0.000E + 00
6th page
k = 0
A4 = 4.63265E-05
A6 = -1.97237E-09
A8 = -4.21441E-07
9th page
k = 0
A4 = -2.78841E-05
A6 = -7.95828E-08
A8 = -1.28129E-06
16th page
k = 0
A4 = -1.82008E-04
A6 = -7.79912E-07
A8 = 5.27383E-08

Zoom data
When D0 (distance from the object to the first surface) is ∞
Wide-angle end Middle Telephoto end
Focal length 6.002 13.702 17.994
FNO. 2.87 3.43 3.76
D8 13.83 4.04 0.8
D11 1.6 11.39 14.64
D12 1.4 5.72 8.81
D15 6.18 5.01 3
D18 5.42 2.26 1.19
D22 1.36 1.36 1.36

  FIG. 27 is a cross-sectional view along the optical axis showing an optical configuration at the time of focusing on an object point at infinity at the wide-angle end of a zoom lens according to Example 14 of the present invention.

  FIG. 28 is a diagram showing spherical aberration, astigmatism, distortion, and lateral chromatic aberration when the zoom lens according to Example 14 is focused on an object point at infinity, where (a) is a wide angle end, (b) is an intermediate view, (c) shows the state at the telephoto end.

  As shown in FIG. 27, the zoom lens of Example 14 includes, in order from the object side, the first lens group G1, the second lens group G2, the aperture stop S, the third lens group G3, and the fourth lens group. G4. In the figure, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

  The first lens group G1 is a cemented lens of a negative meniscus lens L211 having a convex surface facing the object side and a negative meniscus lens L212 having a convex surface facing the object side, and a cemented lens of a prism L213, a biconvex lens L214, and a biconcave lens L215. It has a negative refractive power as a whole.

  The second lens group G2 includes a cemented lens which is formed by a biconvex lens L221 and a negative meniscus lens L222 having a convex surface directed toward the image side, and has a positive refractive power as a whole.

  The third lens group G3 includes a cemented lens which is formed by a biconcave lens L231 and a positive meniscus lens L232 having a convex surface directed toward the object side, and has a negative refracting power as a whole.

  The fourth lens group G4 includes a cemented lens which is formed by a biconvex lens L241 and a negative meniscus lens L242 having a concave surface directed toward the object side, and has a positive refracting power as a whole.

  When zooming from the wide-angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 is moved to the object side, the aperture stop S is fixed, and the third lens group G3 is moved to the image side. Then, the fourth lens group G4 moves to the image side.

  The aspherical surfaces are the image side surface of the negative meniscus lens L212 having a convex surface facing the object side in the first lens group G1, the object side surface of the biconvex lens L214, and the object side of the biconvex lens L221 in the second lens group G2. On the object side surface of the biconvex lens L241 in the fourth lens group G4.

Next, numerical data of this embodiment will be listed.
Numerical data 14
r1 = 35.627
d1 = 1.1 Nd1 = 1.7432 νd1 = 49.34
r2 = 10.5
d2 = 0.35 Nd2 = 1.65228 νd2 = 12.75
r3 = 10.257 (aspherical surface)
d3 = 3.39
r4 = ∞
d4 = 12.5 Nd4 = 1.8061 νd4 = 40.92
r5 = ∞
d5 = 0.4
r6 = 189.603 (Aspherical surface)
d6 = 2.53 Nd6 = 1.8061 νd6 = 40.92
r7 = -14.57
d7 = 5.4 Nd7 = 1.51742 νd7 = 52.43
r8 = 18.292
d8 = D8
r9 = 17.196 (aspherical surface)
d9 = 4.28 Nd9 = 1.7432 νd9 = 49.34
r10 = -13
d10 = 2.17 Nd10 = 1.84666 νd10 = 23.78
r11 = −32.13
d11 = D11
r12 = aperture
d12 = D12
r13 = -16.531
d13 = 0.9 Nd13 = 1.51823 νd13 = 58.9
r14 = 7.005
d14 = 1.57 Nd14 = 1.8061 νd14 = 40.92
r15 = 21.588
d15 = D15
r16 = 14.073 (Aspherical surface)
d16 = 3.44 Nd16 = 1.7432 νd16 = 49.34
r17 = -6
d17 = 1.56 Nd17 = 1.84666 νd17 = 23.78
r18 = -20.07
d18 = D18
r19 = ∞
d19 = 1.44 Nd19 = 1.54771 νd19 = 62.84
r20 = ∞
d20 = 0.8
r21 = ∞
d21 = 0.6 Nd21 = 1.51633 νd21 = 64.14
r22 = ∞
d22 = D22

Aspheric coefficient third surface
k = 0
A4 = 4.66886E-05
A6 = -3.68390E-07
A8 = 0
6th page
k = 0
A4 = 4.41308E-05
A6 = -1.09516E-08
A8 = 0.000E + 00
9th page
k = 0
A4 = -3.06648E-05
A6 = -2.07782E-08
A8 = 0.000E + 00
16th page
k = 0
A4 = -1.41284E-04
A6 = -9.64511E-07
A8 = 0.000E + 00

Zoom data
When D0 (distance from the object to the first surface) is ∞
Wide-angle end Middle Telephoto end
Focal length 6.099 13.417 17.991
FNO. 3.26 3.52 4.58
D8 13.95 3.68 0.4
D11 0.4 12.53 12.79
D12 1.57 4.97 12.55
D15 6.19 5.04 3.12
D18 5.41 2.24 1.07
D22 1.36 1.36 1.36

  FIG. 29 is a cross-sectional view along the optical axis showing the optical configuration at the time of focusing on an object point at infinity at the wide-angle end of the zoom lens according to Example 15 of the present invention.

  FIG. 30 is a diagram illustrating spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 15 is focused on an object point at infinity, where (a) is a wide angle end, (b) is an intermediate view, (c) shows the state at the telephoto end.

  As shown in FIG. 29, in the zoom lens of Example 15, the first lens group G1, the second lens group G2, the aperture stop S, the third lens group G3, and the fourth lens group are sequentially arranged from the object side. G4. In the figure, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

  The first lens group G1 is a cemented lens of a negative meniscus lens L211 having a convex surface facing the object side and a positive meniscus lens L212 having a convex surface facing the object side, and a cemented lens of a prism L213, a biconvex lens L214, and a biconcave lens L215. It has a negative refractive power as a whole.

  The second lens group G2 includes a cemented lens which is formed by a biconvex lens L221 and a negative meniscus lens L222 having a convex surface directed toward the image side, and has a positive refractive power as a whole.

  The third lens group G3 includes a cemented lens which is formed by a biconcave lens L231 and a positive meniscus lens L232 having a convex surface directed toward the object side, and has a negative refracting power as a whole.

  The fourth lens group G4 includes a cemented lens which is formed by a biconvex lens L241 and a negative meniscus lens L242 having a concave surface directed toward the object side, and has a positive refracting power as a whole.

  When zooming from the wide-angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 is moved to the object side, the aperture stop S is fixed, and the third lens group G3 is moved to the image side. Then, the fourth lens group G4 moves to the image side.

  The aspheric surfaces are the image side surface of the positive meniscus lens L212 having a convex surface facing the object side in the first lens group G1, the object side surface of the biconvex lens L214, and the object side of the biconvex lens L221 in the second lens group G2. On the object side surface of the biconvex lens L241 in the fourth lens group G4.

Next, numerical data of this embodiment will be listed.
Numerical data 15
r1 = 30.82
d1 = 1.1 Nd1 = 1.81884 νd1 = 39.35
r2 = 10.5
d2 = 0.35 Nd2 = 1.59885 νd2 = 6.52
r3 = 10.648 (aspherical surface)
d3 = 4.65
r4 = ∞
d4 = 12.5 Nd4 = 1.8061 νd4 = 40.92
r5 = ∞
d5 = 0.4
r6 = 134.153 (Aspherical surface)
d6 = 3.23 Nd6 = 1.82682 νd6 = 41.39
r7 = -12.852
d7 = 0.7 Nd7 = 1.54352 νd7 = 51.79
r8 = 17.506
d8 = D8
r9 = 19.026 (Aspherical surface)
d9 = 3.5 Nd9 = 1.7432 νd9 = 49.34
r10 = -13
d10 = 0.7 Nd10 = 1.84666 νd10 = 23.78
r11 = −34.264
d11 = D11
r12 = aperture
d12 = D12
r13 = -18.881
d13 = 0.7 Nd13 = 1.51823 νd13 = 58.9
r14 = 6.389
d14 = 1.6 Nd14 = 1.8061 νd14 = 40.92
r15 = 20.689
d15 = D15
r16 = 13.519 (aspherical surface)
d16 = 3.5 Nd16 = 1.7432 νd16 = 49.34
r17 = -6
d17 = 0.7 Nd17 = 1.84666 νd17 = 23.78
r18 = -33.096
d18 = D18
r19 = ∞
d19 = 1.44 Nd19 = 1.54771 νd19 = 62.84
r20 = ∞
d20 = 0.8
r21 = ∞
d21 = 0.6 Nd21 = 1.51633 νd21 = 64.14
r22 = ∞
d22 = D22

Aspheric coefficient third surface
k = 0
A4 = 6.29124E-05
A6 = -9.94304E-08
A8 = 0
6th page
k = 0
A4 = 3.57536E-05
A6 = -2.19825E-07
A8 = 0.000E + 00
9th page
k = 0
A4 = -2.33627E-05
A6 = 1.44142E-07
A8 = 0.000E + 00
16th page
k = 0
A4 = -1.46902E-04
A6 = -2.18220E-06
A8 = 0.000E + 00

Zoom data
When D0 (distance from the object to the first surface) is ∞
Wide-angle end Middle Telephoto end
Focal length 6.1 13.421 17.996
FNO. 3.36 3.86 4.73
D8 23.43 6.51 1.75
D11 1.47 10 10.6
D12 0.53 6.33 13.1
D15 6.2 5.15 3.36
D18 5.4 2.12 0.82
D22 1.36 1.36 1.36

  FIG. 31 is a cross-sectional view along the optical axis showing the optical configuration at the time of focusing on an object point at infinity at the wide-angle end of the zoom lens according to Example 16 of the present invention.

  FIG. 32 is a diagram illustrating spherical aberration, astigmatism, distortion, and lateral chromatic aberration when the zoom lens according to Example 16 is focused on an object point at infinity, where (a) is a wide-angle end, (b) is an intermediate view, (c) shows the state at the telephoto end.

  As shown in FIG. 31, the zoom lens of Example 16 includes, in order from the object side, a first lens group G1, a second lens group G2, an aperture stop S, a third lens group G3, and a fourth lens group. G4. In the figure, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

  The first lens group G1 is a cemented lens of a negative meniscus lens L211 having a convex surface facing the object side and a positive meniscus lens L212 having a convex surface facing the object side, and a cemented lens of a prism L213, a biconvex lens L214, and a biconcave lens L215. It has a negative refractive power as a whole.

  The second lens group G2 includes a cemented lens which is formed by a biconvex lens L221 and a negative meniscus lens L222 having a convex surface directed toward the image side, and has a positive refractive power as a whole.

  The third lens group G3 includes a cemented lens which is formed by a biconcave lens L231 and a positive meniscus lens L232 having a convex surface directed toward the object side, and has a negative refracting power as a whole.

  The fourth lens group G4 includes a cemented lens which is formed by a biconvex lens L241 and a negative meniscus lens L242 having a concave surface directed toward the object side, and has a positive refracting power as a whole.

  When zooming from the wide-angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 is moved to the object side, the aperture stop S is fixed, and the third lens group G3 is moved to the image side. Then, the fourth lens group G4 moves to the image side.

  The aspheric surfaces are the image side surface of the positive meniscus lens L212 having a convex surface facing the object side in the first lens group G1, the object side surface of the biconvex lens L214, and the object side of the biconvex lens L221 in the second lens group G2. On the object side surface of the biconvex lens L241 in the fourth lens group G4.

Next, numerical data of this embodiment will be listed.
Numerical data 16
r1 = 31.869
d1 = 1.1 Nd1 = 1.68455 νd1 = 38.62
r2 = 10.5
d2 = 0.35 Nd2 = 1.79525 νd2 = 9.95
r3 = 10.719 (Aspherical surface)
d3 = 4.19
r4 = ∞
d4 = 12.5 Nd4 = 1.8061 νd4 = 40.92
r5 = ∞
d5 = 0.4
r6 = 99.427 (aspherical surface)
d6 = 3.24 Nd6 = 1.82739 νd6 = 42.49
r7 = -13.299
d7 = 0.7 Nd7 = 1.54227 νd7 = 52.3
r8 = 16.692
d8 = D8
r9 = 19.193 (aspherical surface)
d9 = 3.5 Nd9 = 1.7432 νd9 = 49.34
r10 = -13
d10 = 0.7 Nd10 = 1.84666 νd10 = 23.78
r11 = -33.527
d11 = D11
r12 = aperture
d12 = D12
r13 = -18.855
d13 = 0.7 Nd13 = 1.51823 νd13 = 58.9
r14 = 6.427
d14 = 1.6 Nd14 = 1.8061 νd14 = 40.92
r15 = 21.117
d15 = D15
r16 = 14.070 (Aspherical surface)
d16 = 3.5 Nd16 = 1.7432 νd16 = 49.34
r17 = -6
d17 = 0.7 Nd17 = 1.84666 νd17 = 23.78
r18 = -30.061
d18 = D18
r19 = ∞
d19 = 1.44 Nd19 = 1.54771 νd19 = 62.84
r20 = ∞
d20 = 0.8
r21 = ∞
d21 = 0.6 Nd21 = 1.51633 νd21 = 64.14
r22 = ∞
d22 = D22

Aspheric coefficient third surface
k = 0
A4 = 5.65707E-05
A6 = -8.35153E-09
A8 = 0
6th page
k = 0
A4 = 4.41416E-05
A6 = -2.42655E-07
A8 = 0.000E + 00
9th page
k = 0
A4 = -2.48396E-05
A6 = 1.43316E-07
A8 = 0.000E + 00
16th page
k = 0
A4 = -1.47665E-04
A6 = -2.52326E-06
A8 = 0.000E + 00

Zoom data
When D0 (distance from the object to the first surface) is ∞
Wide-angle end Middle Telephoto end
Focal length 6.1 13.42 17.995
FNO. 3.35 3.84 4.67
D8 23.69 6.89 2.16
D11 1.33 9.95 10.69
D12 0.53 6.23 12.79
D15 6.2 5.15 3.38
D18 5.4 2.12 0.81
D22 1.36 1.36 1.36

  FIG. 33 is a cross-sectional view along the optical axis showing an optical configuration at the time of focusing on an object point at infinity at the wide-angle end of a zoom lens according to Example 17 of the present invention.

  FIG. 34 is a diagram showing spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 17 is focused on an object point at infinity, where (a) is the wide-angle end, (b) is the middle, (c) shows the state at the telephoto end.

  As shown in FIG. 33, the zoom lens of Example 17 includes a first lens group G1, a second lens group G2, an aperture stop S, a third lens group G3, and a fourth lens group in order from the object side. G4. In the figure, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

  The first lens group G1 is a cemented lens of a negative meniscus lens L211 having a convex surface facing the object side and a positive meniscus lens L212 having a convex surface facing the object side, and a cemented lens of a prism L213, a biconvex lens L214, and a biconcave lens L215. It has a negative refractive power as a whole.

  The second lens group G2 includes a cemented lens which is formed by a biconvex lens L221 and a negative meniscus lens L222 having a convex surface directed toward the image side, and has a positive refractive power as a whole.

  The third lens group G3 includes a cemented lens which is formed by a biconcave lens L231 and a positive meniscus lens L232 having a convex surface directed toward the object side, and has a negative refracting power as a whole.

  The fourth lens group G4 includes a cemented lens which is formed by a biconvex lens L241 and a negative meniscus lens L242 having a concave surface directed toward the object side, and has a positive refracting power as a whole.

  When zooming from the wide-angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 is moved to the object side, the aperture stop S is fixed, and the third lens group G3 is moved to the image side. Then, the fourth lens group G4 moves to the image side.

  The aspheric surfaces are the image side surface of the positive meniscus lens L212 having a convex surface facing the object side in the first lens group G1, the object side surface of the biconvex lens L214, and the object side of the biconvex lens L221 in the second lens group G2. On the object side surface of the biconvex lens L241 in the fourth lens group G4.

Next, numerical data of this embodiment will be listed.
Numerical data 17
r1 = 36.23
d1 = 1.1 Nd1 = 1.69029 νd1 = 36.36
r2 = 10.5
d2 = 0.35 Nd2 = 1.9712 νd2 = 12.88
r3 = 11.000 (Aspherical surface)
d3 = 3.93
r4 = ∞
d4 = 12.5 Nd4 = 1.8061 νd4 = 40.92
r5 = ∞
d5 = 0.4
r6 = 88.421 (Aspherical surface)
d6 = 2.2 Nd6 = 1.82354 νd6 = 44.73
r7 = -14.187
d7 = 0.7 Nd7 = 1.53704 νd7 = 54.58
r8 = 16.455
d8 = D8
r9 = 18.958 (Aspherical surface)
d9 = 3.5 Nd9 = 1.7432 νd9 = 49.34
r10 = -13
d10 = 0.7 Nd10 = 1.84666 νd10 = 23.78
r11 = −32.852
d11 = D11
r12 = aperture
d12 = D12
r13 = -18.113
d13 = 0.7 Nd13 = 1.51823 νd13 = 58.9
r14 = 6.38
d14 = 1.6 Nd14 = 1.8061 νd14 = 40.92
r15 = 20.833
d15 = D15
r16 = 13.828 (Aspherical surface)
d16 = 3.5 Nd16 = 1.7432 νd16 = 49.34
r17 = -6
d17 = 0.7 Nd17 = 1.84666 νd17 = 23.78
r18 = -29.055
d18 = D18
r19 = ∞
d19 = 1.44 Nd19 = 1.54771 νd19 = 62.84
r20 = ∞
d20 = 0.8
r21 = ∞
d21 = 0.6 Nd21 = 1.51633 νd21 = 64.14
r22 = ∞
d22 = D22

Aspheric coefficient third surface
k = 0
A4 = 5.07303E-05
A6 = -6.94190E-08
A8 = 0
6th page
k = 0
A4 = 4.89135E-05
A6 = -2.70777E-07
A8 = 0.000E + 00
9th page
k = 0
A4 = -2.69831E-05
A6 = 1.67783E-07
A8 = 0.000E + 00
16th page
k = 0
A4 = -1.51906E-04
A6 = -2.58667E-06
A8 = 0.000E + 00

Zoom data
When D0 (distance from the object to the first surface) is ∞
Wide-angle end Middle Telephoto end
Focal length 6.106 13.462 18.001
FNO. 3.32 3.76 4.59
D8 22.99 6.9 2.3
D11 1.19 10.06 10.8
D12 0.53 5.88 12.39
D15 6.19 5.13 3.33
D18 5.4 2.14 0.85
D22 1.36 1.36 1.36

  FIG. 35 is a sectional view taken along the optical axis showing the optical configuration at the time of focusing on an object point at infinity at the wide-angle end of the zoom lens according to Example 18 of the present invention.

  FIG. 36 is a diagram showing spherical aberration, astigmatism, distortion, and lateral chromatic aberration when the zoom lens according to Example 18 is focused on an object point at infinity, where (a) is the wide-angle end, (b) is the middle, (c) shows the state at the telephoto end.

  As shown in FIG. 35, the zoom lens of Example 18 includes, in order from the object side, the first lens group G1, the second lens group G2, the aperture stop S, the third lens group G3, and the fourth lens group. G4. In the figure, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

  The first lens group G1 is a cemented lens of a negative meniscus lens L211 having a convex surface facing the object side and a positive meniscus lens L212 having a convex surface facing the object side, and a cemented lens of a prism L213, a biconvex lens L214, and a biconcave lens L215. It has a negative refractive power as a whole.

  The second lens group G2 includes a cemented lens which is formed by a biconvex lens L221 and a negative meniscus lens L222 having a convex surface directed toward the image side, and has a positive refractive power as a whole.

  The third lens group G3 includes a cemented lens which is formed by a biconcave lens L231 and a positive meniscus lens L232 having a convex surface directed toward the object side, and has a negative refracting power as a whole.

  The fourth lens group G4 includes a cemented lens which is formed by a biconvex lens L241 and a negative meniscus lens L242 having a concave surface directed toward the object side, and has a positive refracting power as a whole.

  When zooming from the wide-angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 is moved to the object side, the aperture stop S is fixed, and the third lens group G3 is moved to the image side. Then, the fourth lens group G4 moves to the image side.

  The aspheric surfaces are the image side surface of the positive meniscus lens L212 having a convex surface facing the object side in the first lens group G1, the object side surface of the biconvex lens L214, and the object side of the biconvex lens L221 in the second lens group G2. On the object side surface of the biconvex lens L241 in the fourth lens group G4.

Next, numerical data of this embodiment will be listed.
Numerical data 18
r1 = 31.999
d1 = 1.1 Nd1 = 1.71082 νd1 = 36.25
r2 = 10.5
d2 = 0.35 Nd2 = 2.0512 νd2 = 6.28
r3 = 10.544 (Aspherical surface)
d3 = 4.21
r4 = ∞
d4 = 12.5 Nd4 = 1.8061 νd4 = 40.92
r5 = ∞
d5 = 0.4
r6 = 81.783 (Aspherical surface)
d6 = 2.2 Nd6 = 1.81694 νd6 = 45.25
r7 = -15.2
d7 = 0.7 Nd7 = 1.53247 νd7 = 56.77
r8 = 16.515
d8 = D8
r9 = 18.404 (Aspherical surface)
d9 = 3.5 Nd9 = 1.7432 νd9 = 49.34
r10 = -13
d10 = 0.7 Nd10 = 1.84666 νd10 = 23.78
r11 = -33.096
d11 = D11
r12 = aperture
d12 = D12
r13 = -16.544
d13 = 0.7 Nd13 = 1.51823 νd13 = 58.9
r14 = 6.208
d14 = 1.6 Nd14 = 1.8061 νd14 = 40.92
r15 = 20.648
d15 = D15
r16 = 12.668 (aspherical surface)
d16 = 3.5 Nd16 = 1.7432 νd16 = 49.34
r17 = -6
d17 = 0.7 Nd17 = 1.84666 νd17 = 23.78
r18 = -34.221
d18 = D18
r19 = ∞
d19 = 1.44 Nd19 = 1.54771 νd19 = 62.84
r20 = ∞
d20 = 0.8
r21 = ∞
d21 = 0.6 Nd21 = 1.51633 νd21 = 64.14
r22 = ∞
d22 = D22

Aspheric coefficient third surface
k = 0
A4 = 3.63151E-05
A6 = -1.62265E-07
A8 = 0
6th page
k = 0
A4 = 4.72473E-05
A6 = -1.61277E-07
A8 = 0.000E + 00
9th page
k = 0
A4 = -2.67300E-05
A6 = 1.00083E-07
A8 = 0.000E + 00
16th page
k = 0
A4 = -1.61823E-04
A6 = -2.44296E-06
A8 = 0.000E + 00

Zoom data
When D0 (distance from the object to the first surface) is ∞
Wide-angle end Middle Telephoto end
Focal length 6.1 13.42 17.995
FNO. 3.3 3.75 4.63
D8 21.27 6.21 1.88
D11 1.45 10.47 11.12
D12 0.54 5.9 12.67
D15 6.19 5.11 3.29
D18 5.4 2.16 0.9
D22 1.36 1.36 1.36

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

  FIG. 37 to FIG. 39 are conceptual diagrams of a configuration in which the imaging optical system according to the present invention is incorporated in a photographing optical system 41 of a digital camera. 37 is a front perspective view showing the appearance of the digital camera 40, FIG. 38 is a rear perspective view thereof, and FIG. 39 is a cross-sectional view showing an optical configuration of the digital camera 40.

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

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

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

  According to the digital camera 40 configured as described above, an electronic imaging device having a compact and thin zoom lens in which the number of components of the photographing optical system 41 is reduced can be realized.

  Next, a personal computer which is an example of an information processing apparatus in which the imaging optical system of the present invention is incorporated as an objective optical system is shown in FIGS. 40 is a front perspective view of the personal computer 300 with the cover open, FIG. 41 is a sectional view of the photographing optical system 303 of the personal computer 300, and FIG. 42 is a side view of FIG. As shown in FIGS. 40 to 42, the personal computer 300 includes a keyboard 301, information processing means and recording means, a monitor 302, and a photographing optical system 303.

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

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

A cover glass 102 for protecting the objective optical system 100 is disposed at the tip of the mirror frame.
The object image received by the electronic image sensor chip 162 is input to the processing means of the personal computer 300 via the terminal 166. Finally, the object image is displayed on the monitor 302 as an electronic image. FIG. 40 shows an image 305 taken by the operator as an example. The image 305 can also be displayed on a communication partner's personal computer from a remote location via the processing means. The Internet and telephone are used for image transmission to remote places.

  Next, FIG. 43 shows a telephone which is an example of an information processing apparatus in which the imaging optical system of the present invention is incorporated as a photographing optical system, particularly a portable telephone which is convenient to carry. 43 (a) is a front view of the mobile phone 400, FIG. 43 (b) is a side view, and FIG. 43 (c) is a cross-sectional view of the photographing optical system 405. 43A to 43C, the mobile phone 400 includes a microphone unit 401, a speaker unit 402, an input dial 403, a monitor 404, a photographing optical system 405, an antenna 406, and processing. Means.

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

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

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

  FIG. 44 is a cross-sectional view along the optical axis showing the optical configuration at the time of focusing on an object point at infinity at the wide angle end of the zoom lens according to Example 20 of the present invention.

  FIG. 45 is a diagram illustrating spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 20 is focused on an object point at infinity. (c) shows the state at the telephoto end. Hereinafter, the number of wavelengths and the types of lines are different from those in the above embodiments.

  As shown in FIG. 44, in the zoom lens of Example 20, the first lens group G1, the second lens group G2, the aperture stop S, the third lens group G3, and the fourth lens group are sequentially arranged from the object side. G4. In the figure, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

  The first lens group G1 includes a negative meniscus lens L311 having a convex surface directed toward the object side, a prism L312 and a biconvex lens L313, and has a positive refractive power as a whole.

  The second lens group G2 includes a cemented lens of a biconcave lens L321, a positive meniscus lens L322 having a convex surface facing the object side, and a positive meniscus lens L323 having a convex surface facing the object side, and has a negative refractive power as a whole. Have.

  The third lens group G3 includes a biconvex lens L331, a cemented lens of a positive meniscus lens L332 having a convex surface directed toward the object side, and a negative meniscus lens L333 having a convex surface directed toward the object side, and has a positive refracting power as a whole. have.

  The fourth lens group G4 includes a positive meniscus lens L341 having a convex surface directed toward the object side, and has a positive refracting power as a whole.

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

  The aspheric surfaces are the image side surface of the negative meniscus lens L311 having a convex surface facing the object side in the first lens group G1, the object side surface of the biconvex lens L313, and the object side of the biconcave lens L322 in the second lens group G2. , The object side surface of the biconvex lens L331 in the third lens group G3, and the object side surface of the positive meniscus lens L341 with the convex surface facing the object side in the fourth lens group G4.

Next, numerical data of this embodiment will be listed.
Numerical data 20
r1 = 23.0649
d1 = 1.0000 Nd1 = 1.84666 νd1 = 23.78
r2 = 9.6457 (Aspherical surface)
d2 = 2.8000
r3 = ∞
d3 = 12.0000 Nd3 = 1.80610 νd3 = 40.92
r4 = ∞
d4 = 0.3000
r5 = 88.9829 (Aspherical surface)
d5 = 3.0000 Nd5 = 1.74320 νd5 = 49.34
r6 = -15.0945
d6 = D6
r7 = -26.3757 (Aspherical surface)
d7 = 0.6000 Nd7 = 1.843481 νd7 = 42.71
r8 = 10.6045
d8 = 0.3000 Nd8 = 1.74999 νd8 = 11.50
r9 = 14.0788
d9 = 1.000 Nd9 = 1.75520 νd9 = 27.51
r10 = 29.0310
d10 = D10
r11 = aperture d11 = D11
r12 = 9.6401 (Aspherical surface)
d12 = 2.7000 Nd12 = 1.69350 νd12 = 53.21
r13 = −35.9013
d13 = 0.1500
r14 = 8.2914
d14 = 2.000 Nd14 = 1.74320 νd14 = 49.34
r15 = 36.0667
d15 = 0.5000 Nd15 = 1.80810 νd15 = 22.26
r16 = 5.3017
d16 = D16
r17 = 12.5524 (Aspherical surface)
d17 = 2.000 Nd17 = 1.48749 νd17 = 70.23
r18 = 52.7375
d18 = D18
r19 = ∞
d19 = 1.5000 Nd19 = 1.54771 νd19 = 62.84
r20 = ∞
d20 = 0.8000
r21 = ∞
d21 = 0.7500 Nd21 = 1.51633 νd21 = 64.14
r22 = ∞
d22 = D22

Aspheric coefficient second surface
K = 0.3393
A4 = -8.7164E-07
A6 = 8.3326E-07
A8 = 0.000E + 00
5th page
K = 0
A4 = -2.2823E-07
A6 = 2.4147E-07
A8 = 0.000E + 00
7th page
K = 0.1921
A4 = 4.0591E-05
A6 = -1.3101E-06
A8 = 0.000E + 00
12th page
K = 0
A4 = -1.6766E-04
A6 = -7.9664E-07
A8 = 0.000E + 00
17th page
K = -1.6449
A4 = -3.9922E-05
A6 = 7.0322E-06
A8 = 0.000E + 00

When zoom data D0 (distance from object to first surface) is ∞
Wide-angle end Middle Telephoto end
Focal length 5.99758 10.39879 18.00658
FNO. 2.8002 3.4404 4.4810
D6 1.00015 6.58975 10.89566
D10 11.30546 5.71784 1.40994
D11 7.69942 4.70147 1.20551
D16 1.49934 5.57484 10.94680
D18 4.95094 3.87286 1.99749
D22 1.35924 1.35924 1.35924

Refractive index table lens 587.56 656.27 486.13 435.84
L322 1.749993 1.733361 1.798570 1.848538
LPF 1.547710 1.545046 1.553762 1.558427
CG 1.516330 1.513855 1.521905 1.526213
L341 1.487490 1.485344 1.492285 1.495963
L312 1.806098 1.800248 1.819945 1.831173
L321 1.834807 1.828975 1.848520 1.859547
L331 1.693501 1.689548 1.702582 1.709715
L313, L332 1.743198 1.738653 1.753716 1.762046
L333 1.808095 1.798009 1.833513 1.855902
L323 1.755199 1.747295 1.774745 1.791495
L311 1.846660 1.836488 1.872096 1.894186

  FIG. 46 is a cross-sectional view along the optical axis showing an optical configuration at the time of focusing on an object point at infinity at the wide angle end of the zoom lens according to Example 21 of the present invention.

  47 is a diagram showing spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 21 is focused on an object point at infinity, where (a) is the wide-angle end, (b) is the middle, (c) shows the state at the telephoto end.

  As shown in FIG. 46, in the zoom lens of Example 23, the first lens group G1, the second lens group G2, the aperture stop S, the third lens group G3, and the fourth lens group are sequentially arranged from the object side. G4 and the fifth lens group G5 are included. In the figure, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

  The first lens group G1 includes a cemented lens which includes a biconvex lens L411 and a negative meniscus lens 412 having a convex surface directed toward the image side, and has a positive refractive power as a whole.

  The second lens group G2 includes a negative meniscus lens L421 having a convex surface directed toward the object side, a prism L422, a negative meniscus lens L423 having a convex surface directed toward the object side, and a positive meniscus lens L424 having a convex surface directed toward the object side. It has a negative refractive power as a whole.

  The third lens group G3 includes a biconvex lens L431, a cemented lens of a positive meniscus lens L432 having a convex surface directed toward the object side, and a negative meniscus lens L433 having a convex surface directed toward the object side, and has a positive refracting power as a whole. is doing.

  The fourth lens group G4 includes a positive meniscus lens L441 having a convex surface directed toward the object side, and has a positive refracting power as a whole.

  The fifth lens group G5 includes a positive meniscus lens L451 having a convex surface directed toward the object side, and has a positive refracting power as a whole.

  When zooming from the wide-angle end to the telephoto end, the first lens group G1 moves to the object side, the second lens group G2 is fixed, the third lens group G3 moves to the object side, and the fourth lens group G4 moves to the object side, and the fifth lens group G5 is fixed. The aperture stop S moves together with the third lens group G3.

  The aspherical surface is an image side surface of the negative meniscus lens L412 having a convex surface facing the image side in the first lens group G1, and an image side surface of the negative meniscus lens L421 having a convex surface facing the object side in the second lens group G2. A positive meniscus lens L424 with the convex surface facing the surface and the object side, an image side surface, an object side surface of the biconvex lens L431 in the third lens group G3, and a positive surface with the convex surface facing the object side in the fifth lens group G5 It is provided on the image side surface of the meniscus lens L451.

Next, numerical data of this embodiment will be listed.
Numerical data 21
r1 = 64.3891
d1 = 4.5000 Nd1 = 1.61800 νd1 = 63.33
r2 = −104.4876
d2 = 0.7000 Nd2 = 1.80810 νd2 = 22.26
r3 = -146.6930 (Aspherical surface)
d3 = D3
r4 = 2271.4163
d4 = 0.8000 Nd4 = 1.69350 νd4 = 53.21
r5 = 11.1791 (aspherical surface)
d5 = 3.1000
r6 = ∞
d6 = 13.600 Nd6 = 1.77250 νd6 = 49.60
r7 = ∞
d7 = 0.3000
r8 = 72.0573
d8 = 0.8000 Nd8 = 1.69350 νd8 = 53.21
r9 = 20.9227
d9 = 0.4500 Nd9 = 1.74909 νd9 = 10.50
r10 = 27.6198 (Aspherical surface)
d10 = D10
r11 = aperture d11 = 0.5000
r12 = 14.6307 (Aspherical surface)
d12 = 2.7000 Nd12 = 1.48348 νd12 = 42.71
r13 = −1200.7221
d13 = 0.1500
r14 = 8.1755
d14 = 2.7000 Nd14 = 1.75500 νd14 = 52.32
r15 = 21.1215
d15 = 0.5000 Nd15 = 1.80810 νd15 = 22.26
r16 = 5.8402
d16 = D16
r17 = 15.3672
d17 = 2.000 Nd17 = 1.69680 vd17 = 55.53
r18 = 41.0165
d18 = D18
r19 = 15.4298
d19 = 2.000 Nd19 = 1.69350 νd19 = 53.21
r20 = 31.1733 (Aspherical surface)
d20 = 1.4000
r21 = ∞
d21 = 1.2000 Nd21 = 1.51633 νd21 = 64.14
r22 = ∞
d22 = D22

Aspheric coefficient third surface
K = 2.5562
A4 = 3.4802E-06
A6 = -1.3562E-08
A8 = 0.000E + 00
5th page
K = -0.0548
A4 = -1.5146E-05
A6 = 1.0588E-06
A8 = 0.000E + 00
10th page
K = 0.1065
A4 = -4.5682E-05
A6 = -1.7394E-07
A8 = 0.000E + 00
12th page
K = 0
A4 = -3.7183E-05
A6 = 2.8983E-07
A8 = -9.4565E-09
20th page
K = -0.1906
A4 = 1.9490E-05
A6 = 7.7662E-06
A8 = 0.000E + 00

When zoom data D0 (distance from object to first surface) is ∞
Wide-angle end Middle Telephoto end
Focal length 6.21259 13.87446 31.00241
FNO. 2.8000 3.7877 4.9732
D3 0.79997 13.61025 21.10787
D10 23.87351 12.91604 1.80057
D16 4.05498 13.70025 10.01866
D18 6.73467 8.05281 22.84411
D22 1.49707 1.50569 1.49693

Refractive index table lens 587.56 656.27 486.13 435.83
L424 1.749093 1.731156 1.802489 1.858477
CG 1.516330 1.513855 1.521905 1.526214
L431 1.834807 1.828975 1.848520 1.859548
L422 1.772499 1.767798 1.783374 1.791972
L421, L423, L451 1.693501 1.689548 1.702582 1.709715
L441 1.696797 1.692974 1.705522 1.712340
L412, L433 1.808095 1.798009 1.833513 1.855904
L411 1.618000 1.615036 1.624794 1.630103
L432 1.754999 1.750624 1.765055 1.772956

  FIG. 48 is a cross-sectional view along the optical axis showing the optical configuration at the time of focusing on an object point at infinity at the wide-angle end of the zoom lens according to Example 22 of the present invention.

  49 is a diagram showing spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 22 is focused on an object point at infinity, where (a) is the wide-angle end, (b) is the middle, (c) shows the state at the telephoto end.

  As shown in FIG. 48, the zoom lens of Example 22 includes, in order from the object side, a first lens group G1, an aperture stop S, a second lens group G2, and a third lens group G3. . In the figure, IRF is an infrared (IR) cut filter, LPF is a low-pass filter, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

  The first lens group G1 includes a cemented lens of a negative meniscus lens L511 having a convex surface facing the object side and a positive meniscus lens L512 having a convex surface facing the object side, and a positive meniscus lens L513 having a convex surface facing the object side. And has a negative refractive power as a whole.

  The second lens group G2 includes a cemented lens of a positive meniscus lens L521 having a convex surface facing the object side, a negative meniscus lens L522 having a convex surface facing the object side, and a biconvex lens L523, and has a positive refractive power as a whole. is doing.

  The third lens group G3 includes a biconvex lens L531, and has a positive refractive power as a whole.

  When zooming from the wide angle end to the telephoto end, the first lens group G1 once moves to the image side and then moves to the object side, the second lens group G2 moves to the object side, and the third lens group G3. Moves to the object side after moving to the object side. The aperture stop S moves together with the second lens group G2.

  The aspherical surface is an image side surface of the negative meniscus lens L512 having a convex surface facing the object side in the first lens group G1, and an object side surface of the positive meniscus lens L521 having a convex surface facing the object side in the second lens group G2. It is provided on the surface.

Next, numerical data of this embodiment will be listed.
Numerical data 22
r1 = 67.6889
d1 = 0.7000 Nd1 = 1.88300 νd1 = 40.76
r2 = 7.0750
d2 = 0.3000 Nd2 = 1.74999 νd2 = 9.00
r3 = 7.4234 (aspherical surface)
d3 = 1.2000
r4 = 13.8463
d4 = 1.3000 Nd3 = 2.00330 νd4 = 28.27
r5 = 23.6727
d5 = D5
r6 = aperture d6 = 1.2000
r7 = 3.7926 (aspherical surface)
d7 = 2.000 Nd7 = 1.88300 νd7 = 40.76
r8 = 10.0010
d8 = 0.5000 Nd8 = 2.00069 νd8 = 25.46
r9 = 3.2669
d9 = 0.6000
r10 = 12.3525
d10 = 1.3000 Nd10 = 1.77250 νd10 = 49.60
r11 = -17.2188
d11 = D11
r12 = 26.0282
d12 = 1.8000 Nd12 = 1.61800 νd12 = 63.33
r13 = -15.7776
d13 = D13
r14 = ∞
d14 = 0.8000 Nd14 = 1.51633 νd14 = 64.14
r15 = ∞
d15 = 1.5000 Nd15 = 1.54771 νd15 = 62.84
r16 = ∞
d16 = 0.8000
r17 = ∞
d17 = 0.7500 Nd17 = 1.51633 νd17 = 64.14
r18 = ∞
d18 = D18

Aspheric coefficient third surface
K = 0
A4 = -3.7270E-04
A6 = 6.5877E-06
A8 = -2.7556E-07
7th page
K = 0
A4 = -6.9841E-04
A6 = -6.9229E-05
A8 = 1.5435E-06

When zoom data D0 (distance from object to first surface) is ∞
Wide-angle end Middle Telephoto end
Focal length 4.54728 8.69224 12.90268
FNO. 2.8000 3.4384 4.4734
D5 14.60292 3.85947 1.50000
D11 2.53628 5.34005 11.64372
D13 0.92173 2.07507 0.99003
D18 1.20425 1.20425 1.20425

Refractive index table lens 587.56 656.27 486.13 435.84
L512 1.749991 1.729523 1.812845 1.880694
LPF 1.547710 1.545046 1.553762 1.558427
IRF, CG 1.516330 1.513855 1.521905 1.526213
L511, L521 1.882997 1.876560 1.898221 1.910495
L523 1.772499 1.767798 1.783374 1.791971
L513 2.003300 1.993011 2.028497 2.049714
L531 1.618000 1.615036 1.624794 1.630103
L522 2.000694 1.989412 2.028719 2.052834

  FIG. 50 is a cross-sectional view along the optical axis showing the optical configuration at the time of focusing on an object point at infinity at the wide-angle end of the zoom lens according to Example 23 of the present invention.

  FIG. 51 is a diagram illustrating spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 23 is focused on an object point at infinity, where (a) is a wide-angle end, (b) is an intermediate view, (c) shows the state at the telephoto end.

  As shown in FIG. 50, the zoom lens of Example 23 includes, in order from the object side, the first lens group G1, the aperture stop S, the second lens group G2, the third lens group G3, and the fourth lens group. G4. In the figure, CG is a cover glass, and I is an image pickup surface of an electronic image pickup element.

  The first lens group G1 includes a negative meniscus lens L611 having a convex surface facing the object, a prism L612, a negative meniscus lens L613 having a convex surface facing the image side, and a positive meniscus lens L614 having a convex surface facing the image side. It has a negative refractive power as a whole.

  The second lens group G2 includes a cemented lens of a positive meniscus lens L621 having a convex surface directed toward the object side, a negative meniscus lens L622 having a convex surface directed toward the object side, and a biconvex lens L623, and is positively refracted as a whole. Have power.

  The third lens group G3 includes a biconvex lens L631 and has a positive refractive power as a whole.

  The fourth lens group G4 includes a biconvex lens L641, and has a positive refractive power as a whole.

  When zooming from the wide-angle end to the telephoto end, the first lens group G1 is fixed, the second lens group G2 moves to the object side, the third lens group G3 moves to the object side, and the fourth lens group G4 is fixed. The aperture stop S moves together with the second lens group G2.

  The aspherical surface is an image side surface of a negative meniscus lens L611 having a convex surface facing the object side in the first lens group G1, and an object side surface of the positive meniscus lens L621 having a convex surface facing the object side in the second lens group G2. And the image side surface of the biconvex lens L641 in the fourth lens group G4.

Next, numerical data of this embodiment will be listed.
Numerical data 23
r1 = 14.6157
d1 = 0.7000 Nd1 = 1.77250 νd1 = 49.60
r2 = 5.8309 (Aspherical surface)
d2 = 1.2000
r3 = ∞
d3 = 6.8000 Nd3 = 1.77250 νd3 = 49.60
r4 = ∞
d4 = 0.6000
r5 = −6.3287
d5 = 0.5000 Nd5 = 1.77250 νd5 = 49.60
r6 = -34.8010
d6 = 0.000 Nd6 = 1.74999 νd6 = 10.50
r7 = -14.3351
d7 = D7
r8 = aperture d8 = 0.
r9 = 3.6833 (Aspherical surface)
d9 = 1.8000 Nd9 = 1.81600 νd9 = 46.62
r10 = 14.6826
d10 = 0.5000 Nd10 = 1.80810 νd10 = 22.76
r11 = 3.2340
d11 = 0.7000
r12 = 13.1671
d12 = 1.6500 Nd12 = 1.72916 νd12 = 54.68
r13 = -19.1557
d13 = D13
r14 = 7.8455
d14 = 1.000 Nd14 = 1.48749 νd14 = 70.23
r15 = -91.5527
d15 = D15
r16 = 41.6383
d16 = 1.2000 Nd16 = 1.69350 νd16 = 53.21
r17 = -4778.3934 (Aspherical surface)
d17 = 0.7000
r18 = ∞
d18 = 0.6000 Nd18 = 1.51633 νd18 = 64.14
r19 = ∞
d19 = D19

Aspheric coefficient second surface
K = 0
A4 = -1.6369E-04
A6 = -4.2195E-05
A8 = 6.5104E-07

9th page
K = 0
A4 = -1.1364E-03
A6 = -2.4892E-05
A8 = -6.4515E-06

17th page
K = 0
A4 = 7.0720E-04
A6 = 4.3851E-04
A8 = -4.4293E-05

When zoom data D0 (distance from object to first surface) is ∞
Wide-angle end Middle Telephoto end
Focal length 3.25205 5.64151 9.74919
FNO. 2.5244 3.1906 4.0990
D7 9.36505 4.34860 0.90094
D13 1.09929 3.55635 1.09927
D15 4.30822 6.87699 12.77228
D19 0.99993 0.99993 0.99993

Refractive index table lens 587.56 656.27 486.13 435.83
L614 1.749993 1.732032 1.803451 1.859494
CG 1.516330 1.513855 1.521905 1.526214
L631 1.487490 1.485344 1.492285 1.495964
L621 1.816000 1.810749 1.828252 1.837997
L611, L612, L613 1.772499 1.767798 1.783374 1.791972
L641 1.693501 1.689548 1.702582 1.709715
L623 1.729157 1.725101 1.738436 1.745696
L622 1.808095 1.798009 1.833513 1.855904

  As described above, the imaging optical system of the present invention and the electronic imaging device using the same have the following features in addition to the invention described in the claims.

(1) The imaging optical system according to claim 1, wherein the following conditional expression is satisfied.
1.48 <β <2.04
Here, Nd represents the refractive index of the glass material used for the cemented lens, and νd represents the Abbe number of the glass material used for the cemented lens, and satisfies the relationship Nd = α × νd + β.

(2) The imaging optical system according to claim 1, wherein the following conditional expression is satisfied.
1.50 <β <2.00
Here, Nd represents the refractive index of the glass material used for the cemented lens, and νd represents the Abbe number of the glass material used for the cemented lens, and satisfies the relationship Nd = α × νd + β.

(3) The imaging optical system according to claim 1, wherein the following conditional expression is satisfied.
1.58 <Nd <2.10
Nd is the refractive index of the glass material used for the cemented lens.

(4) The imaging optical system according to claim 1, wherein the following conditional expression is satisfied.
1.63 <Nd <1.95
Nd is the refractive index of the glass material used for the cemented lens.

(5) The imaging optical system according to claim 1, wherein the following conditional expression is satisfied.
5 <νd <10
Where νd is the Abbe number of the glass material used for the cemented lens.

(6) The imaging optical system according to claim 1, wherein the following conditional expression is satisfied.
6 <νd <9
Where νd is the Abbe number of the glass material used for the cemented lens.

(7) The electronic imaging apparatus according to (10), wherein the zoom lens satisfies the following conditional expression when focusing on an object point at infinity.
0.75 <y ₀₇ / (fw · tan ω _07w ) <0.94
However, y ₀₇ is y ₀₇ = 0.7y ₁₀ , where y ₁₀ is the distance (maximum image height) from the center to the farthest point in the effective imaging plane (in the plane where imaging is possible) of the electronic imaging device. expressed. Further, ω _07w is an angle with respect to the optical axis in the object point direction corresponding to the image point connecting from the center on the imaging surface to the position of y ₀₇ at the wide angle end.

(8) The electronic imaging apparatus according to (10), wherein the zoom lens satisfies the following conditional expression when focusing on an object point at infinity.
0.80 <y ₀₇ / (fw · tan ω _07w ) <0.92
However, y ₀₇ is y ₀₇ = 0.7y ₁₀ , where y ₁₀ is the distance (maximum image height) from the center to the farthest point in the effective imaging plane (in the plane where imaging is possible) of the electronic imaging device. expressed. Further, ω _07w is an angle with respect to the optical axis in the object point direction corresponding to the image point connecting from the center on the imaging surface to the position of y ₀₇ at the wide angle end.

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

It is sectional drawing which follows the optical axis which shows the optical structure at the time of infinity object point focusing in the wide angle end of the zoom lens concerning Example 1 of this invention. FIG. 3 is a diagram illustrating spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 1 is focused on an object point at infinity, where (a) is the wide-angle end, (b) is the middle, (c) Indicates the state at the telephoto end. It is sectional drawing which follows the optical axis which shows the optical structure at the time of infinity object point focusing in the wide angle end of the zoom lens concerning Example 2 of this invention. FIG. 7 is a diagram illustrating spherical aberration, astigmatism, distortion, and lateral chromatic aberration when the zoom lens according to Example 2 is focused on an object point at infinity, where (a) is a wide-angle end, (b) is an intermediate, (c) Indicates the state at the telephoto end. It is sectional drawing which follows the optical axis which shows the optical structure at the time of infinity object point focusing in the wide angle end of the zoom lens concerning Example 3 of this invention. FIG. 10 is a diagram illustrating spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 3 is focused on an object point at infinity, where (a) is a wide-angle end, (b) is a middle, (c) Indicates the state at the telephoto end. It is sectional drawing which follows the optical axis which shows the optical structure at the time of infinity object point focusing in the wide angle end of the zoom lens concerning Example 4 of this invention. FIG. 10 is a diagram illustrating spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 4 is focused on an object point at infinity, where (a) is a wide-angle end, (b) is a middle, (c) Indicates the state at the telephoto end. FIG. 10 is a cross-sectional view along an optical axis showing an optical configuration at the time of focusing on an object point at infinity at the wide angle end of a zoom lens according to Example 5 of the present invention; FIG. 10 is a diagram illustrating spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 5 is focused on an object point at infinity, where (a) is a wide-angle end, (b) is a middle, (c) Indicates the state at the telephoto end. It is sectional drawing which follows the optical axis which shows the optical structure at the time of infinity object point focusing in the wide angle end of the zoom lens concerning Example 6 of this invention. FIG. 10 is a diagram illustrating spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 6 is focused on an object point at infinity, where (a) is a wide-angle end, (b) is a middle, (c) Indicates the state at the telephoto end. It is sectional drawing which follows the optical axis which shows the optical structure at the time of infinity object point focusing in the wide angle end of the zoom lens concerning Example 7 of this invention. FIG. 10 is a diagram illustrating spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 7 is focused on an object point at infinity, where (a) is a wide-angle end, (b) is a middle, (c) Indicates the state at the telephoto end. It is sectional drawing which follows the optical axis which shows the optical structure at the time of infinity object point focusing in the wide angle end of the zoom lens concerning Example 8 of this invention. FIG. 10 is a diagram illustrating spherical aberration, astigmatism, distortion aberration, and chromatic aberration of magnification when the zoom lens according to Example 8 is focused on an object point at infinity, where (a) is a wide-angle end, (b) is an intermediate position, (c) Indicates the state at the telephoto end. It is sectional drawing which follows the optical axis which shows the optical structure at the time of an infinite object point focusing in the wide angle end of the zoom lens concerning Example 9 of this invention. FIG. 10 is a diagram illustrating spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 9 is focused on an object point at infinity, where (a) is a wide-angle end, (b) is an intermediate, and (c). Indicates the state at the telephoto end. It is sectional drawing which follows the optical axis which shows the optical structure at the time of infinity object point focusing in the wide angle end of the zoom lens concerning Example 10 of this invention. FIG. 11 is a diagram illustrating spherical aberration, astigmatism, distortion, and lateral chromatic aberration when the zoom lens according to Example 10 is focused on an object point at infinity, where (a) is a wide-angle end, (b) is an intermediate, (c) Indicates the state at the telephoto end. It is sectional drawing which follows the optical axis which shows the optical structure at the time of infinity object point focusing in the wide angle end of the zoom lens concerning Example 11 of this invention. FIG. 10 is a diagram illustrating spherical aberration, astigmatism, distortion, and lateral chromatic aberration when the zoom lens according to Example 11 is focused on an object point at infinity, where (a) is a wide-angle end, (b) is an intermediate, (c) Indicates the state at the telephoto end. It is sectional drawing which follows the optical axis which shows the optical structure at the time of infinity object point focusing in the wide angle end of the zoom lens concerning Example 12 of this invention. FIG. 14 is a diagram showing spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 12 is focused on an object point at infinity, where (a) is a wide-angle end, (b) is an intermediate, (c) Indicates the state at the telephoto end. It is sectional drawing which follows the optical axis which shows the optical structure at the time of infinity object point focusing in the wide angle end of the zoom lens concerning Example 13 of this invention. FIG. 14 is a diagram illustrating spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 13 is focused on an object point at infinity, where (a) is a wide-angle end, (b) is a middle, (c) Indicates the state at the telephoto end. It is sectional drawing which follows the optical axis which shows the optical structure at the time of infinity object point focusing in the wide angle end of the zoom lens concerning Example 14 of this invention. FIG. 14 is a diagram showing spherical aberration, astigmatism, distortion aberration, and chromatic aberration of magnification when the zoom lens according to Example 14 is focused on an object point at infinity, where (a) is a wide angle end, (b) is an intermediate position, (c) Indicates the state at the telephoto end. It is sectional drawing which follows the optical axis which shows the optical structure at the time of infinity object point focusing in the wide angle end of the zoom lens concerning Example 15 of this invention. FIG. 18 is a diagram illustrating spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 15 is focused on an object point at infinity, where (a) is a wide-angle end, (b) is an intermediate position, and (c) Indicates the state at the telephoto end. It is sectional drawing which follows the optical axis which shows the optical structure at the time of infinity object point focusing in the wide angle end of the zoom lens concerning Example 16 of this invention. FIG. 18 is a diagram illustrating spherical aberration, astigmatism, distortion, and lateral chromatic aberration when the zoom lens according to Example 16 is focused on an object point at infinity, where (a) is a wide-angle end, (b) is an intermediate, (c) Indicates the state at the telephoto end. It is sectional drawing which follows the optical axis which shows the optical structure at the time of infinity object point focusing in the wide angle end of the zoom lens concerning Example 17 of this invention. FIG. 18 is a diagram illustrating spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 17 is focused on an object point at infinity, where (a) is a wide-angle end, (b) is a middle, (c) Indicates the state at the telephoto end. It is sectional drawing which follows the optical axis which shows the optical structure at the time of infinity object point focusing in the wide angle end of the zoom lens concerning Example 18 of this invention. FIG. 19 is a diagram illustrating spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 18 is focused on an object point at infinity, where (a) is a wide-angle end, (b) is an intermediate, and (c) Indicates the state at the telephoto end. It is a front perspective view which shows the external appearance of the digital camera 40 incorporating the zoom optical system by this invention. 2 is a rear perspective view of the digital camera 40. FIG. 2 is a cross-sectional view showing an optical configuration of a digital camera 40. FIG. 1 is a front perspective view of a state in which a cover of a personal computer 300 which is an example of an information processing apparatus in which a zoom optical system of the present invention is built as an objective optical system is opened. FIG. 2 is a cross-sectional view of a photographing optical system 303 of a personal computer 300. FIG. 2 is a side view of a personal computer 300. FIG. 1A and 1B are diagrams showing a mobile phone as an example of an information processing apparatus in which a zoom optical system of the present invention is incorporated as a photographing optical system, in which FIG. 1A is a front view of the mobile phone 400, FIG. FIG. 6 is a cross-sectional view of the photographing optical system 405. It is sectional drawing which follows the optical axis which shows the optical structure at the time of infinity object point focusing in the wide angle end of the zoom lens concerning Example 20 of this invention. FIG. 20 is a diagram illustrating spherical aberration, astigmatism, distortion, and chromatic aberration of magnification when the zoom lens according to Example 20 is focused on an object point at infinity, in which (a) is a wide angle end, (b) is an intermediate, (c) Indicates the state at the telephoto end. It is sectional drawing which follows the optical axis which shows the optical structure at the time of infinity object point focusing in the wide angle end of the zoom lens concerning Example 21 of this invention. FIG. 22 is a diagram illustrating spherical aberration, astigmatism, distortion, and lateral chromatic aberration when the zoom lens according to Example 21 is focused on an object point at infinity, where (a) is a wide-angle end, (b) is a middle, (c) Indicates the state at the telephoto end. It is sectional drawing which follows the optical axis which shows the optical structure at the time of infinity object point focusing in the wide angle end of the zoom lens concerning Example 22 of this invention. FIG. 22 is a diagram illustrating spherical aberration, astigmatism, distortion, and lateral chromatic aberration when the zoom lens according to Example 22 is focused on an object point at infinity, where (a) is a wide-angle end, (b) is a middle, (c) Indicates the state at the telephoto end. It is sectional drawing which follows the optical axis which shows the optical structure at the time of infinity object point focusing in the wide angle end of the zoom lens concerning Example 23 of this invention. FIG. 22 is a diagram illustrating spherical aberration, astigmatism, distortion, and lateral chromatic aberration when the zoom lens according to Example 23 is focused on an object point at infinity, where (a) is a wide-angle end, (b) is an intermediate, (c) Indicates the state at the telephoto end. It is a figure which shows the relationship between the number of r and d in the numerical data of each Example, and an optical structure (a lens surface, thickness, an air space | interval).

Explanation of symbols

G1 1st lens group G2 2nd lens group G3 3rd lens group G4 4th lens group G5 5th lens group L111-L242 Each lens CG Cover glass I Imaging surface E Eyeball of observer 40 Digital camera 41 Shooting optical system 42 Shooting Optical path 43 Viewfinder optical system 44 Optical path for viewfinder 45 Shutter 46 Flash 47 LCD monitor 49 CCD
DESCRIPTION OF SYMBOLS 50 Image pick-up surface 51 Processing means 53 Finder objective optical system 55 Porro prism 57 Field frame 59 Eyepiece optical system 66 Focusing lens 67 Imaging surface 100 Objective optical system 102 Cover glass 162 Electronic image pick-up element chip | tip 166 Terminal 300 Personal computer 301 Keyboard 302 Monitor 303 Imaging Optical System 304 Imaging Optical Path 305 Image 400 Mobile Phone 401 Microphone Unit 402 Speaker Unit 403 Input Dial 404 Monitor 405 Imaging Optical System 406 Antenna 407 Imaging Optical Path

Claims (10)

In an imaging optical system having a positive lens group, a negative lens group, and a diaphragm,
The negative lens group is disposed closer to the object side than the diaphragm,
The negative lens group has a cemented lens formed by cementing a plurality of lenses,
When a straight line represented by Nd = α × νd + β (where α = −0.017) is set in an orthogonal coordinate system in which the horizontal axis is Nd and the vertical axis is νd,
The area defined by the straight line when the lower limit value is within the range of the conditional expression (1) and the straight line when the upper limit value is satisfied, and the area determined by the following conditional expressions (2) and (3) An imaging optical system including Nd and νd of at least one lens constituting the cemented lens.
1.45 <β <2.15 (1)
1.30 <Nd <2.20 (2)
3 <νd <12 (3)
Here, Nd represents a refractive index and νd represents an Abbe number.   When one lens in which both Nd and νd are included in both the areas is a predetermined lens, the optical axis center thickness of the predetermined lens is thinner than the optical axis center thickness of the other lenses constituting the cemented lens The imaging optical system according to claim 1. The imaging optical system according to claim 2, wherein the following conditional expression is satisfied.
0.22 <t1 <2.0
However, t1 is the optical axis center thickness of the predetermined lens.   The image forming optical system according to claim 1, wherein the cemented lens is a compound lens obtained by bonding and curing a resin on a lens surface of one lens constituting the cemented lens.   The imaging optical system according to claim 1, wherein the cemented lens is a compound lens formed by closely bonding and curing glass on a lens surface of one lens constituting the cemented lens.   The imaging optical system according to claim 1, wherein the imaging optical system is a zoom lens whose object side is a positive group.   The imaging optical system according to claim 1, wherein the imaging optical system is a zoom lens having a negative group closest to the object side.   The imaging optical system according to claim 1, wherein the imaging optical system includes a prism for bending.   9. The imaging optical system according to claim 8, wherein the prism is in a group closest to the object side. The imaging optical system according to any one of claims 1 to 9, an electronic imaging device, and image data obtained by imaging an image formed through the imaging optical system with the electronic imaging device. Image processing means for processing and outputting as image data in which the shape of the image is changed, and the imaging optical system is a zoom lens, and when the zoom lens is focused on an object point at infinity, the following conditions are satisfied: An electronic imaging apparatus characterized by satisfying the formula:
0.7 <y ₀₇ / (fw · tan ω _07w ) <0.96
However, the table as y ₀₇ = 0.7y ₁₀ when y ₀₇ is obtained by the y ₁₀ distance (maximum image height) to a point farthest from the center in the effective image pickup plane (imaging possible in-plane) of the electronic image pickup device Is done. Further, ω _07w is an angle with respect to the optical axis in the object point direction corresponding to the image point connecting from the center on the imaging surface to the position of y ₀₇ at the wide angle end.

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