JP2013037145A - Zoom lens and information device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a zoom lens of an inner focus system having small size and high performance, a small travel of a focus group, a half field angle of 41 degrees or more at a wide angle end, a variable power ratio from 2.8 times to 3.5 times, and resolution corresponding to an image sensor having pixels exceeding 5 million-10 million.SOLUTION: A zoom lens is arranged with: a first positive lens group I, a second negative lens group II, a third negative lens group III, a fourth positive lens group IV and a fifth positive lens group V in an order from an object side in an optical axis, and an aperture diaphragm S between the third and the fourth lens group. When varying power from the wide angle end to the telephoto end, all lens groups are moved so as to increase an interval between the first and the second lens group and an interval between the second and the third lens group, and decrease an interval between the third and the fourth lens group and an interval between the fourth and the fifth lens group. The third lens group is constituted of one negative meniscus lens with a concave surface facing the object side, and focusing is performed by moving the third lens group in the optical axis direction thereof to satisfy conditions (1)-(3).

Description

The present invention relates to a zoom lens and an information device.
The zoom lens according to the present invention can be implemented as a zoom lens for imaging in an imaging apparatus such as a digital still camera, a silver halide photography camera, a video camera, or a digital video camera. The information device can be implemented as a digital still camera, a portable information terminal device, or the like.

In recent years, a zoom lens is generally used as a photographing optical system used for a digital still camera or the like. In particular, a “zoom lens including an angle of view of about 50 mm in terms of a 35 mm format in the focal length range” is generally known.
In these zoom lenses, there is a strong demand from users for downsizing, widening the angle, and increasing the speed of autofocus (hereinafter referred to as “AF”).

  In order from the object side to the image side, a so-called “positive lead type” zoom lens having a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a succeeding group that follows the first lens group. It is easy to enlarge the zoom ratio, and it is easy to reduce the overall length by the configuration of the front of the positive group, and various types are conventionally known (Patent Documents 1 to 5).

  The zoom lenses described in Patent Documents 1 to 5 are all of the so-called “inner focus type”, and the one described in Patent Document 1 performs focusing by moving the second lens group. In all of the described ones, focusing is performed by moving the third lens group.

In the case of the “zoom lens that performs focusing by moving the second lens group” described in Patent Document 1, since the weight of the second lens group to be moved is large during focusing, the motor and the actuator tend to be large, and the maximum diameter of the lens barrel Tends to grow.
Since the weight of the second lens group is large, there is no problem in terms of speeding up AF and “quieting during moving image shooting”.

  In the zoom lenses described in Patent Documents 2 to 5, focusing is performed by a third lens group having a negative refractive power.

However, in the zoom lenses described in Patent Documents 2 to 4, it is difficult to say that the focus group is sufficiently light.
In the zoom lens described in Patent Document 5, the third lens group that performs focusing is composed of “one negative lens”, and the focus group is reduced in weight, so that the AF speed is increased and the lens barrel diameter is small. Can be achieved. However, there is still room for improvement in the performance of the third lens group in terms of performance and zoom lens compactness.

  In view of the above, the present invention is an inner focus method, which has a small amount of movement of the focus group, is small and high performance, has a half angle of view of 41 degrees or more at the wide angle end, and a zoom ratio of 2.8 to 3. It is an object of the present invention to make it possible to realize a zoom lens having a resolving power corresponding to an imaging element of about 5 times to 5 million to 10 million pixels.

  The present invention is also the above-described inner focus method, in which the amount of movement of the focus group is small, small size and high performance, the half angle of view at the wide angle end is 41 degrees or more, and the zoom ratio is about 2.8 to 3.5 times. It is an object of the present invention to realize a zoom lens having a resolving power corresponding to an image pickup element exceeding 5 million to 10 million pixels.

  It is another object of the present invention to provide a compact, lightweight information device with a good performance equipped with such a zoom lens.

  The zoom lens according to the present invention is “a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a negative refractive power, and a positive refraction in order from the object side along the optical axis. A fourth lens group having a positive power and a fifth lens group having a positive refractive power are disposed, and a diaphragm is disposed between the third lens group and the fourth lens group, and zooming from the wide angle end to the telephoto end is performed. The distance between the first lens group and the second lens group increases, the distance between the second lens group and the third lens group increases, the distance between the third lens group and the fourth lens group decreases, and the fourth A zoom lens in which all the lens groups move so that the distance between the lens group and the fifth lens group is reduced, and is characterized by the following points.

  That is, the third lens group is composed of one negative lens, and the negative lens is a “negative meniscus lens having a concave surface facing the object side”.

  “Focusing” is performed by moving the third lens group in the optical axis direction.

The combined lateral magnification of the fourth lens group and the fifth lens group when the object distance is infinity at the wide angle end: β _{45 W} , and the fourth lens group and the fifth lens group when the object distance is infinity at the telephoto end. The combined lateral magnification of the lens group: β _45T is the condition:
(1) 2.0 <β _45T / β _45W <2.5
(2) −1.1 <β _{45 W} <−0.7
(3) -2.4 <β _45T <-1.8
Satisfied.

In the zoom lens according to claim 1, the focal length of the fourth lens group: F4, the focal length of the fifth lens group: F5, the focal length at the wide angle end: Fw, and the focal length at the telephoto end: Ft geometric mean: Fm (= √ (Fw × Ft)) is the condition:
(4) 1.0 <F4 / Fm <1.5
(5) 1.1 <F5 / Fm <1.8
Is preferably satisfied (claim 2).
The zoom lens according to claim 1 or 2, wherein at the wide angle end, when the object distance is infinity, the lateral magnification of the third lens group: β _3W , and at the telephoto end, the third lens group when the object distance is infinity. Horizontal magnification: β _3T , conditions:
(6) 0.7 <β _3T / β _3W <0.98
Is preferably satisfied (Claim 3).
The zoom lens according to any one of claims 1 to 3, wherein the Abbe number: vd of the material of the negative meniscus lens constituting the third lens group and having the concave surface facing the object side is:
(7) vd> 50
Is preferably satisfied (claim 4).

The zoom lens according to any one of claims 1 to 4, wherein the maximum image height is Y ′, the focal length at the wide angle end is Fw, the focal length at the telephoto end is Ft, and the focal length at the wide angle end is Fw. ,conditions:
(8) 0.75 <Y '/ Fw
(9) 2.8 <Ft / Fw
Is preferably satisfied (Claim 5).

  An “information device” of the present invention includes the zoom lens according to any one of claims 1 to 5 as a photographing optical system (claim 6).

  The information device according to claim 6 may be “an object image formed by a zoom lens is formed on a light receiving surface of an image sensor” (claim 7). The information device according to claim 7 can be “configured as a portable information terminal device” (claim 8).

  In the zoom lens according to the present invention, all of the first to fifth lens units move during zooming. In this way, all the lens groups contribute to zooming, so that the burden on zooming of each lens group can be reduced, which is not only advantageous for aberration correction and lens workability, but also for zooming. Accordingly, the amount of movement of the first lens group can be efficiently reduced, and the zoom lens can be easily downsized.

In the zoom lens of the present invention, the fourth lens group and the fifth lens group (hereinafter collectively referred to as the “successor group”) are provided in order to increase the degree of freedom in lens design and to further reduce the size and increase the performance. The “contribution to zooming” is increased.
When increasing the “contribution to zooming” of the succeeding group, if the degree of contribution is not appropriate, the balance with “contribution to zooming of the second lens group or the third lens group” is lost, and as a side effect, the zoom lens Increase in size, “increase in manufacturing error sensitivity”, and insufficient correction of various aberrations.
The condition (1) of claim 1 defines an appropriate range of “contribution to zooming” of the succeeding group.

Parameter (1): β _45T / β _45W represents the “degree of change in lateral magnification of the succeeding group” upon zooming from the wide-angle end to the telephoto end. The larger the value of this parameter, the larger the value of the succeeding group. “Contribution to zooming” increases, and the contribution of the second and third lens units to zooming decreases.

  If the “contribution to zooming” of the second and third lens groups decreases, the amount of movement accompanying zooming of the second lens group decreases, which is advantageous for downsizing the zoom lens.

  However, if the upper limit of the condition (1): 2.5 is exceeded, the contribution of the subsequent group to the zooming becomes excessive, the contribution of the second and third lens groups becomes excessively small, The “correction of various aberrations” tends to be insufficient due to the rise in the balance and the balance of contribution.

If the parameter of condition (1): β _45T / β _45W decreases, contrary to the above, the “contribution to zooming” of the subsequent group decreases, and the eccentric sensitivity of the subsequent group decreases. The burden for zooming of the three lens groups increases.

  If the lower limit of the condition (1) is less than 2.0, the “movement amount associated with zooming” of the second lens group becomes excessive, and it is difficult to reduce the size of the zoom lens.

  That is, the zoom lens can be reduced in size by satisfying the condition (1) that defines the optimum range of contribution to the zooming of the subsequent group.

  In the zoom lens according to the present invention, the third lens group having negative refractive power is used as the focus group, so that the focus group can be reduced in weight and the amount of movement can be reduced, and the AF is speeded up and silenced. doing.

In the configuration of the zoom lens according to claim 1, the lateral magnification of the focus group: β _F, and the combined lateral magnification of the subsequent group (fourth and fifth lens groups) disposed on the image side of the focus group: β ₄₅ , The relationship with the focus sensitivity: FS (the ratio of the focus movement amount to the movement amount of the focus group) is as follows:
FS = (1−β _F ² ) × (β ₄₅ ) ²
It is represented by

Therefore, as the combined lateral magnification β _{45 of} the fourth and fifth lens groups that are the succeeding group of the focus group (third lens group) becomes “larger in absolute value”, the focus sensitivity: FS increases. It can be seen that the desired focus sensitivity can be achieved even if the amount of movement of a certain third lens group is reduced.

In the parameters (2) and (3) of the conditions (2) and β _45W and β _45T , the absolute value decreases toward the upper limit side, and the absolute value increases toward the lower limit side.

  If the upper limit of conditions (2) and (3) is exceeded, the focus sensitivity: FS will be too small at both the wide-angle end and the telephoto end, and the amount of movement of the focus group (third lens group) should be reduced. Not only makes it difficult to increase the speed of AF, but also makes it difficult to reduce the size of the zoom lens, particularly at the telephoto end.

  On the other hand, if the lower limit value of the conditions (2) and (3) is not reached, the focus sensitivity: FS becomes excessive at both the wide-angle end and the telephoto end.

  An increase in focus sensitivity means a decrease in the amount of movement of the focus group, which is advantageous for increasing the AF speed at the wide-angle end, and increasing the AF speed and zoom lens size at the telephoto end. However, “excessive focus sensitivity” tends to increase the manufacturing error sensitivity, and tends to cause “decrease in focusing accuracy” particularly at the telephoto end.

  By simultaneously satisfying the above conditions (1) to (3), it becomes possible to satisfactorily balance “the amount of movement of the second lens unit due to zooming and the amount of movement of the third lens unit for focusing”. It is possible to realize a zoom lens that is small in size, has low manufacturing error sensitivity, and can correct various aberrations in a balanced manner.

The parameters of the conditions (1) to (3) are more preferably the following conditions slightly narrower than those of the conditions (1) to (3):
(1A) 2.07 <β _45T / β _45W <2.35
(2A) −0.95 <β _45W <−0.85
(3A) −2.2 <β _45T <−1.85
Good to be satisfied.

  By satisfying the conditions (4) and (5) of claim 2 in addition to the above conditions, further high performance can be realized.

Conditions (4) and (5) are conditions that define appropriate ranges of the focal lengths of the fourth lens group and the fifth lens group, respectively.
In both conditions (4) and (5), if the lower limit is not reached, the power of each group increases, which is advantageous for downsizing. Increase in various aberrations due to an unbalanced balance of power distribution.
If the upper limit of the conditions (4) and (5) is exceeded, the eccentricity sensitivity and the like are lowered, but it is difficult to reduce the size.

  By satisfying the conditional expressions (1) to (5) at the same time, that is, by making the power distribution of the fourth and fifth lens groups and the combined lateral magnification appropriate, it is small in size, low in decentration sensitivity, and various aberrations. It becomes possible to obtain a zoom lens in which the increase is suppressed more favorably.

The parameters of the conditions (4) and (5) are more preferably slightly narrower than the conditions (4) and (5), and the following conditions:
(4A) 1.0 <F4 / Fm <1.4
(5A) 1.1 <F5 / Fm <1.6
It is good to satisfy.

  When the condition (6) of claim 3 is satisfied together with the above conditions (1) to (5), the zoom lens can be further reduced in size.

  As described above, in the zoom lens according to the present invention, the third lens group that performs focusing also contributes to zooming.

  Condition (6) defines an appropriate range of contribution of the third lens group to zooming.

Parameter: β _3T / β _3W is the “ratio of the lateral magnification at the telephoto end to the lateral magnification at the wide-angle end” of the third lens group, so that the larger this parameter is, the more variable the magnification of the third lens group is. Will contribute more.

  Outside the range of condition (6), the contribution of the third lens group to zooming is “under or over”, and the balance between the contribution of the second lens group and the fourth and fifth lens groups to zooming is balanced. This tends to cause collapse, an increase in manufacturing error sensitivity, an enlargement of the zoom lens, and an increase in various aberrations.

The parameter of condition (6): β _3T / β _3W is more preferably slightly narrower than that of condition (6).
(6A) 0.70 <β _3T / β _3W <0.96
It is good to satisfy.

  Since the third lens group is composed of “one negative lens”, by forming this third lens group with “a relatively low dispersion glass material” that satisfies the condition (7), various chromatic aberrations can be obtained. Occurrence can be effectively suppressed, and the burden on the other lens group for suppressing chromatic aberration is reduced, which is advantageous in terms of aberration correction.

  The condition (8) is a condition for restricting the angle of view of the zoom lens. By satisfying the condition (8), the half angle of view at the wide angle end is 36.8 degrees as shown in an example described later. Thus, a high-performance and compact zoom lens can be obtained.

  The condition (9) regulates the zoom ratio, and a zoom lens satisfying the condition (9) has a zoom ratio of 2.8 times or more.

The parameters of the conditions (8) and (9) are more preferably slightly narrower than the conditions (8) and (9):
(8A) 0.87 <Y ′ / Fw
(9A) 3 <Ft / Fw <5
Good to be satisfied.

Although it may be simpler in terms of mechanism that the aperture diameter of the aperture is “constant regardless of zooming”, the change in the F number can be reduced by changing the aperture diameter at the telephoto end compared to the wide-angle end. You can also.
If it is necessary to reduce the amount of light that reaches the image plane, the aperture may be made smaller. However, reducing the amount of light by inserting an ND filter or the like without greatly changing the aperture diameter lowers the resolving power due to the diffraction phenomenon. Is preferable.

  To add a little about the group configuration of the zoom lens according to the present invention, the magnification of the first to third lens groups is increased by increasing the number of lens groups on the image side relative to the third lens group, which is the focus group, and moving it during zooming. The lens design can be reduced, the degree of freedom in lens design can be increased, and aberration correction and processability can be improved. However, increasing the number of lens groups on the image side relative to the third lens group increases the length of the zoom lens.・ This leads to an increase in size.

  Conversely, if the fourth lens group is the only lens group on the image side of the third lens group, it is advantageous for downsizing the zoom lens, but the degree of freedom in design is reduced and aberration correction is difficult. Increase.

  The “5 lens group configuration” of the zoom lens according to the present invention can be said to be an appropriate number of lens groups in order to achieve both a reduction in size and performance of the zoom lens.

  In the information apparatus according to the seventh and eighth aspects, “an object image by the zoom lens is formed on the light receiving surface of the image sensor”. When an object image is read and converted into image data by an image sensor (CCD area sensor or CMOS), the image data is electronic information, and this can be electronically processed.

  In particular, distortion can be corrected electronically, and a method for correcting distortion by an “electronic processing” of an image formed on an image sensor is already known.

  Accordingly, among various aberrations of the zoom lens, distortion aberration can be “corrected electronically”, and if the distortion aberration can be allowed within the allowable range that can be corrected electronically, other aberrations can be improved. It can be corrected well.

  As described above, according to the present invention, a novel zoom lens and information device can be realized. In the zoom lens according to the present invention, the focusing group (third lens group) for performing focusing is sufficiently compact, the amount of movement during focusing is small, can be realized in a small size, and high-speed AF is possible.

  And, as in the embodiments described later, the half angle of view at the wide-angle end is 36.8 degrees or more, the zoom ratio is about 2.8 to 3.3 times, the aberration is sufficiently corrected, the size is small, and 500 It can be realized as a zoom lens having a resolving power corresponding to a high-resolution image sensor exceeding 10,000 to 10,000,000 pixels.

  By mounting such a zoom lens, a small and high-performance information device can be realized.

FIG. 3 is a diagram for explaining a zoom lens of Example 1; FIG. 3 is an aberration diagram at a wide angle end of the zoom lens according to Example 1; FIG. 4 is an aberration diagram for the zoom lens of Example 1 at an intermediate focal length. FIG. 4 is an aberration diagram at a telephoto end of the zoom lens in Example 1; 6 is a diagram for explaining a zoom lens according to Example 2. FIG. FIG. 6 is an aberration diagram at a wide-angle end of the zoom lens according to Example 2; 6 is an aberration diagram at an intermediate focal length of the zoom lens of Example 2. FIG. 6 is an aberration diagram at a telephoto end of a zoom lens in Example 2. FIG. 6 is a diagram for explaining a zoom lens according to Example 3. FIG. FIG. 10 is an aberration diagram at a wide-angle end of the zoom lens according to Example 3; FIG. 10 is an aberration diagram at an intermediate focal length of the zoom lens according to Example 3; 6 is an aberration diagram at a telephoto end of a zoom lens in Example 3; FIG. FIG. 10 is a diagram for explaining a zoom lens according to Example 4; FIG. 10 is an aberration diagram at a wide-angle end of the zoom lens according to Example 4; FIG. 10 is an aberration diagram at an intermediate focal length of the zoom lens according to Example 4; FIG. 10 is an aberration diagram at a telephoto end of a zoom lens in Example 4; FIG. 10 is a diagram for explaining a zoom lens according to Example 5; FIG. 10 is an aberration diagram at a wide-angle end of the zoom lens according to Example 5; FIG. 10 is an aberration diagram at an intermediate focal length of the zoom lens according to Example 5; 10 is an aberration diagram at a telephoto end of a zoom lens in Example 5. FIG. FIG. 10 is a diagram for explaining a zoom lens according to Example 6; FIG. 10 is an aberration diagram at a wide-angle end of the zoom lens according to Example 6; FIG. 10 is an aberration diagram at an intermediate focal length of the zoom lens according to Example 6; 10 is an aberration diagram at a telephoto end of a zoom lens in Example 6; FIG. FIG. 10 is a diagram for explaining a zoom lens according to Example 7; 10 is an aberration diagram at a wide-angle end of a zoom lens according to Example 7. FIG. 10 is an aberration diagram at an intermediate focal length of the zoom lens in Example 7. FIG. 10 is an aberration diagram at a telephoto end of a zoom lens in Example 7. FIG. FIG. 10 is a diagram for explaining a zoom lens according to Example 8; 10 is an aberration diagram at a wide-angle end of the zoom lens according to Example 8; FIG. FIG. 10 is an aberration diagram at an intermediate focal length of the zoom lens according to Example 8; 10 is an aberration diagram at a telephoto end of a zoom lens in Example 8. FIG. FIG. 10 is a diagram for explaining a zoom lens according to Example 9; 10 is an aberration diagram at a wide-angle end of the zoom lens according to Example 9; FIG. FIG. 10 is an aberration diagram at an intermediate focal length of the zoom lens according to Example 9; 10 is an aberration diagram at a telephoto end of a zoom lens in Example 9. FIG. It is a figure for demonstrating one Embodiment of a portable information terminal device. It is a figure for demonstrating the system configuration | structure of the apparatus of FIG.

  Hereinafter, embodiments will be described.

  9, 9, 13, 17, 21, 21, 25, 29, and 33 sequentially show nine examples of zoom lens embodiments. These embodiments correspond to Examples 1 to 9 described later in the above order.

  In order to avoid complications, the same reference numerals are used in the above drawings.

  That is, in FIGS. 1, 5, 9, 13, 17, 17, 21, 25, 29, and 33, the left side of the figure is the object side and the right side is the image plane side.

  The zoom lens includes, in order from the object side along the optical axis, a first lens group I having a positive refractive power, a second lens group II having a negative refractive power, a third lens group III having a negative refractive power, and a positive refraction. A fourth lens group IV having a positive power and a fifth lens group V having a positive refractive power are disposed, and an aperture stop S is disposed between the third lens group III and the fourth lens group IV.

  In each of the above drawings, the upper diagram shows the lens arrangement at the “wide-angle end”, the middle diagram shows the lens arrangement at the “intermediate focal length”, and the lower diagram shows the lens arrangement at the “telephoto end”. The “arrow” indicates the movement of each lens group accompanying zooming from the wide-angle end to the telephoto end.

As is clear from the above figures, in the zoom lens of the present invention, all the lens groups move during zooming from the wide-angle end to the telephoto end.
That is, the distance between the first lens group I and the second lens group II is increased, the distance between the second lens group II and the third lens group III is increased, and the third lens group III and the fourth lens group IV are increased. The interval decreases, and the interval between the fourth lens group IV and the fifth lens group V decreases. The aperture stop S moves integrally with the fourth lens group during zooming.

  The third lens group III is composed of “one negative lens”, and this negative lens is a “negative meniscus lens having a concave surface facing the object side”. Then, focusing is performed by the movement of the third lens group III in the optical axis direction.

  In each of the above drawings, the symbol F drawn on the right side of the drawing is two transparent parallel plates.

  In a “camera apparatus using a solid-state image pickup device such as a CCD or CMOS” such as a digital still camera, a low-pass filter, an infrared cut glass, etc. are provided close to the light receiving surface of the solid-state image pickup device. The light receiving surface of the element is protected by a “cover glass”.

  The above-mentioned “transparent parallel plate” is obtained by virtually replacing various filters such as a low-pass filter and a cover glass with “two transparent parallel plates optically equivalent to these”.

The configuration of each lens group of the zoom lens according to the embodiment shown in the above drawings is as follows.
The first lens group I includes, in order from the object side, a cemented lens of a negative meniscus lens having a convex surface facing the object side and a positive meniscus lens having a convex surface facing the object side.

The second lens group II includes, in order from the object side, a negative meniscus lens having a convex surface directed toward the object side, a biconcave lens, and a biconvex lens.
The third lens group III includes one negative meniscus lens having a strong concave surface facing the object side.

  The fourth lens group IV includes, in order from the object side, a biconvex lens and a cemented lens of the biconvex lens and the biconcave lens.

  The fifth lens group V includes, in order from the object side, a biconvex lens and a negative meniscus lens having a convex surface directed toward the object side.

With reference to FIGS. 37 and 38, an embodiment of a portable information terminal device will be described.
FIG. 37 shows the appearance of the camera device (camera function unit of the portable information terminal device), and FIG. 38 shows the system configuration of the portable information terminal device.
As shown in FIG. 38, the portable information terminal device 30 includes a photographic lens 31 and a light receiving element (a solid-state imaging device in which 5 to 10 million pixels are two-dimensionally arranged) 45, and is formed by the photographic lens 31. The “photographing object image” is read by the light receiving element 45.

  As the photographic lens 31, the “zoom lens” according to any one of claims 1 to 5, more specifically, a zoom lens of Examples 1 to 9 described later is used. Zooming is performed by adjustment by the zooming adjustment unit 34. At this time, the finder 33 also zooms in conjunction.

  The output from the light receiving element 45 is processed by the signal processing device 42 under the control of the central processing unit 40, converted into digital information, and the digitized image information is received by the image processing device 41 under the control of the central processing unit 40. After being subjected to predetermined image processing, it is recorded in the semiconductor memory 44.

  The liquid crystal monitor 38 can display an image being image-processed by the image processing device 41 and a zooming state thereof, and can also display an image recorded in the semiconductor memory 44. The image recorded in the semiconductor memory 44 can be transmitted to the outside using a communication card 43 or the like.

  The image processing apparatus 41 also has a function of performing “electrical shading correction”, “trimming of the image center”, and the like.

  As shown in FIG. 37, when the photographing lens 31 is carried, it is in a retracted state as shown in FIG. 37 (a). When the user operates the power switch 36 to turn on the power, the mirror 31 as shown in FIG. 37 (b). The torso is paid out.

  At this time, each group of zoom lenses in the lens barrel is “arranged at an infinite object distance”, and “focusing to a finite object distance” is performed by half-pressing the shutter button 35. The focusing operation is performed by “moving the third lens group” as described above.

  When an image recorded in the semiconductor memory 44 is displayed on the liquid crystal monitor 38 or transmitted to the outside using a communication card or the like, the operation button 37 shown in FIG. 37C is used. A semiconductor memory, a communication card, and the like are used by being inserted into dedicated or general-purpose slots 39A and 39B, respectively.

  When the photographic lens 31 is in the retracted state, the lens groups do not necessarily have to be aligned on the optical axis. For example, the first lens group and the second lens group are retracted from the optical axis, If the mechanism is such that it is housed in parallel with the lens group, the portable information terminal device can be made thinner.

  In the “portable information terminal apparatus having a camera device as a photographing unit” as described above, the imaging lens of Examples 1 to 9 can be used as the photographing lens 31, and light reception of 5 to 10 million pixels is possible. A portable information terminal device having a high image quality and a small camera function using the element 45 can be realized.

  Hereinafter, nine specific examples will be given.

The meanings of the symbols in the examples are as follows.
f: Focal length of the entire system
F: F number
ω: Half angle of view (deg)
Surface number: Number of the surface (including the aperture, filter, and light receiving surface of the image sensor) counted from the object side R: Radius of curvature (Paraxial radius of curvature for aspheric surfaces)
D: Surface spacing Nd: Refractive index νd: Abbe number K: Aspherical conical constant A4: Fourth-order aspherical constant A6: Sixth-order aspherical constant A8: Eighth-order aspherical constant A10: Tenth-order aspherical surface Constant A12: 12th-order aspheric constant.

The aspherical shape is a reciprocal of the paraxial radius of curvature (paraxial curvature): C, height from the optical axis: H, conic constant: K, and the non-spherical coefficients of the above orders, where X is the non-axis in the optical axis direction. As a spherical quantity, the well-known formula X = CH ² / [1 + √ {1− (1 + K) C ² H ² }]
+ A4 · H ⁴ + A6 · H ⁶ + A8 · H ⁸ + A10 · H ¹⁰ + A12 · H ¹² + ··
The shape is specified by giving a paraxial radius of curvature, a conic constant, and an aspherical coefficient.

"Example 1"
Example 1 is the zoom lens shown in FIG.
f = 16.146-53.852 F = 3.59-5.93 ω = 41.53-14.87
Surface number R D Nd νd
1 35.22784 1.30000 1.84666 23.7800
2 25.43981 5.58108 1.69680 55.5300
3 161.95730 Variable A
4 66.68463 0.97007 2.00100 29.1300
5 10.93000 6.31830
6 -29.18377 0.80000 1.69350 53.1800
7 26.19043 0.09955
8 25.80601 4.24896 1.84666 23.7800
9 -27.63060 Variable B
10 -20.24167 0.80000 1.60300 65.4400 (S-PHM53)
11 -50.23484 Variable C
12 ∞ (Aperture) 1.45001
13 15.31467 3.43574 1.51633 64.0600
14 -38.17926 0.10000
15 21.44923 3.93180 1.53172 48.8400
16 -17.87906 1.45000 1.83400 37.1600
17 19.58694 Variable D
18 19.29863 4.94809 1.58913 61.1500
19 -19.58674 0.23493
20 48.01352 0.80173 1.90366 31.3200
21 16.49362 Variable E
22 ∞ 0.70000 1.53770 66.6000
23 ∞ 1.50000
24 ∞ 0.70000 1.50000 64.0000
25 ∞.

"Aspherical data"
The aspherical data are listed below.
6th page
K = 0
A4 = -1.12571E-05
A6 = 1.21899E-07
A8 = 2.76874E-09
A10 = -4.5160E-11
A12 = 1.38009E-13
7th page
K = 0
A4 = -4.98762E-05
A6 = 3.02710E-07
A8 = -1.83352E-09
A10 = -4.9553E-12
Side 13
K = 0
A4 = -2.23034E-05
A6 = -3.30061E-08
A8 = 1.96596E-09
A10 = -4.33079E-11
14th page
K = 0
A4 = -6.86789E-06
A6 = 1.59127E-07
A8 = -8.05125E-10
A10 = -2.46291E-11
18th page
K = -4.76959
A4 = -2.06414E-06
A6 = -1.71695E-07
A8 = -2.33143E-09
A10 = 6.08643E-12
19th page
K = 0.25043
A4 = 3.72591E-05
A6 = -4.11291E-08
A8 = -2.02648E-09
A10 = 3.86766E-12
In the display of the aspheric data, for example, “3.86766E-12” represents “3.86766 × 10 ⁻¹² ”. The same applies to the following embodiments.

  The glass material of the lens of the third lens group is assumed to be “S-PHM53” manufactured by OHARA.

  Νd and θg, F of S-PHM53 are as follows from the published catalog.

νd = 65.44
θg, F = 0.5401
"Variable amount"
Variable amounts of data are shown in Table 1.

  FIG. 2 to FIG. 4 sequentially show aberration diagrams of the first embodiment at the wide angle end, the intermediate focal length, and the telephoto end. The broken line in the spherical aberration diagram represents “sine condition”, the solid line in the astigmatism diagram represents “sagittal”, and the broken line represents “meridional”. “G” and “d” represent g-line and d-line, respectively. The same applies to the aberration diagrams of the other examples.

"Example 2"
Example 2 is the zoom lens shown in FIG.

f = 16.146-53.851 F = 3.6-5.77 ω = 41.53-14.87
Surface number R D Nd νd
1 43.11718 1.29999 1.84666 23.78
2 31.73933 5.57706 1.69680 55.53
3 190.09719 Variable A
4 55.24695 0.97008 2.00100 29.13
5 10.53158 7.00758
6 -37.69153 0.80000 1.69350 53.18
7 39.79764 0.12000
8 35.75261 4.22772 1.84666 23.78
9 -27.02142 Variable B
10 -22.16816 0.80000 1.60300 65.44 (S-PHM53)
11 -68.86241 Variable C
12 ∞ (Aperture) 1.45020
13 17.70983 4.99510 1.51633 64.06
14 -25.76032 0.10000
15 24.82196 3.73181 1.53172 48.84
16 -18.83887 1.44999 1.83400 37.16
17 19.93203 Variable D
18 18.95445 5.30000 1.58913 61.15
19 -22.79198 0.10000
20 46.10650 0.80000 1.90366 31.32
21 16.80062 Variable E
22 ∞ 0.70000 1.53770 66.60
23 ∞ 1.50000
24 ∞ 0.70000 1.50000 64.00
25 ∞.

"Aspherical data"
Aspherical data are shown below.
6th page
K = 0
A4 = -6.13912E-05
A6 = 6.02764E-07
A8 = -3.68927E-09
A10 = -5.86282E-12
7th page
K = 0
A4 = -9.55771E-05
A6 = 6.67024E-07
A8 = -5.78157E-09
A10 = 3.44512E-12
Side 13
K = 0
A4 = -2.21195E-05
A6 = -1.07672E-06
A8 = 1.98544E-08
A10 = -3.47093E-10
14th page
K = 0
A4 = 5.12674E-06
A6 = -9.94310E-07
A8 = 1.53589E-08
A10 = -2.78900E-10
18th page
K = -1.2879
A4 = -1.57778E-05
A6 = -7.80973E-08
A8 = -8.69905E-10
A10 = 3.89552E-12
19th page
K = 0.98584
A4 = 4.43195E-05
A6 = 5.66872E-08
A8 = -2.64609E-09
A10 = 1.33387E-11
The glass material of the lens of the third lens group is assumed to be “S-PHM53” manufactured by OHARA.

  Νd and θg, F of S-PHM53 are as follows from the published catalog.

νd = 65.44
θg, F = 0.5401.

"Variable amount"
Variable amounts of data are shown in Table 2.

  FIGS. 6 to 8 sequentially show aberration diagrams of the second embodiment at the wide-angle end, the intermediate focal length, and the telephoto end.

"Example 3"
Example 3 is the zoom lens shown in FIG.

f = 16.146 to 53.85 F = 3.62 to 5.67 ω = 41.53 to 14.87
Surface number R D Nd νd
1 44.83622 1.30000 1.84666 23.78
2 30.32788 5.80250 1.77250 49.60
3 152.20233 Variable A
4 55.56877 0.97009 2.00100 29.13
5 10.85110 6.67902
6 -40.92454 0.80000
7 36.32245 0.65885
8 30.89732 4.44422 1.84666 23.78
9 -26.99833 Variable B
10 -24.45877 0.80000 1.64850 53.02 (S-BSM71)
11 -103.58339 Variable C
12 ∞ (Aperture) 1.45008
13 16.52481 5.35383 1.51633 64.06
14 -25.99633 0.10000
15 23.78029 3.61747 1.51742 52.43
16 -22.01894 1.45000 1.83400 37.16
17 17.55937 Variable D
18 19.88520 5.30000 1.58913 61.15
19 -22.74438 0.10000
20 53.58387 0.80000 1.90366 31.32
21 18.67841 Variable E
22 ∞ 0.70000 1.53770 66.60
23 ∞ 1.50000
24 ∞ 0.70000 1.50000 64.00
25 ∞.

"Aspherical data"
The aspheric data is shown below.
6th page
K = 0
A4 = -8.18151E-06
A6 = -2.01833E-07
A8 = 2.53333E-09
A10 = -1.29107E-11
7th page
K = 0
A4 = -3.23283E-05
A6 = -1.88341E-07
A8 = 1.96755E-09
A10 = -1.43273E-11
Side 13
K = 0
A4 = -3.22004E-05
A6 = -9.60992E-07
A8 = 1.55589E-08
A10 = -2.82657E-10
14th page
K = 0
A4 = 3.53815E-06
A6 = -8.66214E-07
A8 = 1.17377E-08
A10 = -2.24402E-10
18th page
K = -1.27337
A4 = -1.58768E-05
A6 = -1.86624E-07
A8 = 6.94712E-10
A10 = -5.97184E-12
19th page
K = 0
A4 = 3.31640E-05
A6 = -1.06067E-07
A8 = -6.29723E-10
A10 = 0
The glass material of the lens of the third lens group is assumed to be “S-BSM71” manufactured by OHARA.

  Νd and θg, F of S-BSM71 are as follows from the published catalog.

νd = 53.02
θg, F = 0.5547.

"Variable amount"
Variable amounts of data are shown in Table 3.

  10 to 12 sequentially show aberration diagrams of the third embodiment at the wide angle end, the intermediate focal length, and the telephoto end.

"Example 4"
Example 4 is the zoom lens shown in FIG.

f = 16.146 to 53.852 F = 3.68 to 5.55 ω = 41.53 to 14.87
Surface number R D Nd νd
1 34.95704 1.30001 1.84666 23.78
2 23.60593 5.86984 1.741 52.64
3 151.1807 Variable A
4 299.95707 0.97009 2.001 29.13
5 11.13285 4.29663
6 -70.40818 0.8 1.8086 40.42
7 36.93918 0.99318
8 25.74916 3.66798 1.84666 23.78
9 -25.74916 Variable B
10 -18.53351 0.8 1.58913 61.14
11 -393.50471 Variable C
12 ∞ 1.44993
13 15.66887 4.15645 1.48749 70.23
14 -27.94159 0.1
15 13.07805 3.77258 1.53172 48.84
16 -26.8818 2.00933 1.834 37.16
17 12.0058 Variable D
18 24.19269 5.29997 1.58913 61.15
19 -13.20634 0.37853
20 -19.02546 0.79998 1.90366 31.32
21 -138.0287 Variable E
22 ∞ 0.7 1.5 168 64.2
23 ∞ 1.5
24 ∞ 0.7 1.5168 64.2.

"Aspherical data"
The aspheric data is shown below.
6th page
K = 0.0
A4 = -3.843970E-05
A6 = 1.211950E-07
A8 = -5.466700E-09
A10 = 3.589930E-11
A12 = 5.576910E-13
7th page
K = 0.0
A4 = -6.229330E-05
A6 = 1.289240E-07
A8 = -9.269550E-09
A10 = 1.049680E-10
Side 13
K = 0.0
A4 = 4.838910E-06
A6 = -2.840070E-07
A8 = 8.697220E-09
A10 = -1.836370E-11
14th page
K = 0.0
A4 = 4.698360E-05
A6 = -1.627670E-07
A8 = 5.742440E-09
A10 = 2.564070E-11
18th page
K = -1.373112
A4 = 1.668360E-05
A6 = 1.266830E-07
A8 = -5.146740E-09
A10 = 1.518190E-10
19th page
K = -2.895300E-02
A4 = 7.250660E-05
A6 = 6.967700E-07
A8 = -1.676340E-08
A10 = 2.591100E-10
The glass material of the lens of the third lens group is assumed to be “S-BAL35” manufactured by OHARA.

  Νd and θg, F of S-PHM53 are as follows from the published catalog.

νd = 61.14
θg, F = 0.5407.

"Variable amount"
Variable amounts of data are shown in Table 4.

  FIGS. 14 to 16 sequentially show aberration diagrams of the fourth embodiment at the wide angle end, the intermediate focal length, and the telephoto end. In Example 4, the maximum image height: Y ′ at the wide-angle end is 12.25 and distortion is greatly generated. However, the distortion at the wide-angle end is obtained by using electronic data of an image obtained from the image sensor. The maximum image height can be set to 14.3 mm by correcting with a known “distortion aberration correction” algorithm.

"Example 5"
Example 5 is the zoom lens shown in FIG.

f = 16.146-53.84 F = 3.63-5.74 ω = 41.5-14.87
Surface number R D Nd νd
1 46.03179 1.30005 1.84666 23.78
2 31.22940 5.51888 1.77250 49.60
3 152.04501 Variable A
4 51.07120 0.97002 2.00100 29.13
5 10.77721 6.63709
6 -42.16678 0.79999 1.77030 47.40
7 38.75553 0.96368
8 30.38725 4.33203 1.84666 23.78
9 -29.02408 Variable B
10 -21.91807 0.80000 1.64850 53.02 (S-BSM71)
11 -79.56447 Variable C
12 ∞ (Aperture) 1.44994
13 18.62497 4.02774 1.51633 64.06
14 -25.81393 0.09995
15 20.81187 4.01271 1.51742 52.43
16 -19.74213 1.44999 1.83400 37.16
17 19.22015 Variable D
18 20.95766 5.30002 1.58913 61.15
19 -22.01066 0.10001
20 42.36060 0.79999 1.90366 31.32
21 16.44550 Variable E
22 ∞ 0.70000 1.53770 66.60
23 ∞ 1.50000
24 ∞ 0.70000 1.50000 64.00
25 ∞.

"Aspherical data"
Aspherical data are shown below.
6th page
K = 0
A4 = 5.52979E-05
A6 = -1.46723E-06
A8 = 1.40955E-08
A10 = -5.75258E-11
7th page
K = 0
A4 = 3.02092E-05
A6 = -1.53901E-06
A8 = 1.44769E-08
A10 = -6.26901E-11
Side 13
K = 0
A4 = -8.40542E-06
A6 = -4.37152E-07
A8 = 1.03740E-08
A10 = -2.45238E-10
14th page
K = 0
A4 = 2.47361E-05
A6 = -6.21729E-07
A8 = 1.37690E-08
A10 = -2.72842E-10
18th page
K = -0.92674
A4 = -1.83059E-05
A6 = -3.30349E-08
A8 = -2.28321E-09
A10 = -6.15846E-13
19th page
K = 0
A4 = 3.19375E-05
A6 = 3.31577E-08
A8 = -2.88956E-09
A10 = 0
The glass material of the lens of the third lens group is assumed to be “S-BSM71” manufactured by OHARA.

  Νd and θg, F of S-BSM71 are as follows from the published catalog.

νd = 53.02
θg, F = 0.5547.

"Variable amount"
Variable amounts of data are shown in Table 5.

    FIG. 18 to FIG. 20 sequentially show aberration diagrams of the fifth embodiment at the wide angle end, the intermediate focal length, and the telephoto end.

"Example 6"
Example 6 is the zoom lens shown in FIG.

f = 16.15 to 53.852 F = 3.62 to 5.77 ω = 41.53 to 14.87
Surface number R D Nd νd
1 52.97005 1.31000 1.84666 23.78
2 35.71101 5.48584 1.77250 49.60
3 189.65170 Variable A
4 57.34337 0.95497 2.00100 29.13
5 11.09490 6.36289
6 -52.53144 0.80001 1.77030 47.40
7 36.40322 1.16039
8 30.42534 4.23829 1.84666 23.78
9 -30.42507 Variable B
10 -22.85191 0.80000 1.64850 53.02 (S-BSM71)
11 -92.38759 Variable C
12 ∞ (Aperture) 1.40001
13 19.49107 3.32058 1.51633 64.06
14 -25.78639 0.11538
15 18.99577 4.01733 1.51742 52.43
16 -18.99577 1.40000 1.83400 37.16
17 18.99577 Variable D
18 19.38104 5.59999 1.58913 61.15
19 -23.21203 0.10000
20 34.69037 0.80000 1.90366 31.32
21 14.67162 Variable E
22 ∞ 0.70000 1.53770 66.60
23 ∞ 1.50000
24 ∞ 0.70000 1.50000 64.00
25 ∞.

"Aspherical data"
How to show aspheric data.
6th page
K = 0
A4 = 2.63554E-05
A6 = -1.09237E-06
A8 = 9.8447E-09
A10 = -3.41409E-11
7th page
K = 0
A4 = 2.93738E-06
A6 = -1.13624E-06
A8 = 1.01043E-08
A10 = -3.88306E-11
Side 13
K = 0
A4 = 3.21402E-07
A6 = -1.03872E-07
A8 = 6.34622E-09
A10 = -1.99948E-10
14th page
K = 0
A4 = 2.47699E-05
A6 = -2.4115E-07
A8 = 9.50458E-09
A10 = -2.36136E-10
18th page
K = -0.57855
A4 = -1.83484E-05
A6 = -2.90044E-08
A8 = -1.90061E-09
A10 = -5.50054E-12
19th page
K = -0.09961
A4 = 3.54974E-05
A6 = 3.43435E-08
A8 = -3.14805E-09
The glass material of the lens of the third lens group is assumed to be “S-BSM71” manufactured by OHARA.

  Νd and θg, F of S-BSM71 are as follows from the published catalog.

νd = 53.02
θg, F = 0.5547.

"Variable amount"
The variable amount of data is shown in Table 6.

  FIG. 22 to FIG. 24 sequentially show aberration diagrams of Example 6 at the wide-angle end, the intermediate focal length, and the telephoto end.

"Example 7"
Example 7 is the zoom lens shown in FIG.

f = 16.146-53.852 F = 3.61-5.76 ω = 41.53-14.87
Surface number R D Nd νd
1 53.02258 1.31000 1.84666 23.78
2 35.94362 5.46329 1.77250 49.60
3 188.67998 Variable A
4 54.87412 0.95512 2.00100 29.13
5 10.79646 6.44587
6 -51.91885 0.80000 1.74320 49.29
7 40.63394 1.06371
8 31.38598 4.08243 1.84666 23.78
9 -31.38598 Variable B
10 -23.00149 0.80000 1.65160 58.55 (S-LAL7)
11 -97.40089 Variable C
12 ∞ (Aperture) 1.39999
13 19.57334 3.29549 1.51633 64.06
14 -25.26589 0.10000
15 19.46405 3.89071 1.51742 52.43
16 -19.46405 1.40519 1.83400 37.16
17 19.46405 Variable D
18 19.69818 5.60000 1.58913 61.15
19 -22.10614 0.10000
20 38.97349 0.80019 1.90366 31.32
21 15.14672 Optional
22 ∞ 0.70000 1.53770 66.60
23 ∞ 1.50000
24 ∞ 0.70000 1.50000 64.00
25 ∞.
"Aspherical data"
How to show aspheric data.
6th page
K = 0
A4 = 3.46877E-05
A6 = -1.27443E-06
A8 = 1.11921E-08
A10 = -4.40045E-11
7th page
K = 0
A4 = 6.8617E-06
A6 = -1.34447E-06
A8 = 1.13537E-08
A10 = -4.81564E-11
Side 13
K = 0
A4 = -1.2513E-06
A6 = -4.84014E-08
A8 = 5.40686E-09
A10 = -2.0620E-10
14th page
K = 0
A4 = 2.71708E-05
A6 = -2.3373E-07
A8 = 9.93932E-09
A10 = -2.54318E-10
18th page
K = -0.65075
A4 = -1.90482E-05
A6 = -3.34777E-08
A8 = -1.71693E-09
A10 = -5.56274E-12
19th page
K = -0.20854
A4 = 3.63343E-05
A6 = 2.45318E-08
A8 = -2.95008E-09.

  The glass material of the lens of the third lens group is assumed to be “S-LAL7” manufactured by OHARA.

  Νd and θg, F of S-LAL7 are as follows from the published catalog.

νd = 58.55
θg, F = 0.5425.

"Variable amount"
Variable amounts of data are shown in Table 7.

  FIGS. 26 to 28 sequentially show aberration diagrams of the seventh embodiment at the wide-angle end, the intermediate focal length, and the telephoto end.

"Example 8"
Example 8 is the zoom lens shown in FIG.

f = 16.145 to 53.86 F = 3.64 to 5.75 ω = 41.53 to 14.87
Surface number R D Nd νd
1 51.57017 1.35033 1.84666 23.78
2 35.08789 5.69112 1.7725 49.6
3 182.91872 Variable A
4 44.57654 0.98972 2.001 29.13
5 10.55643 6.75921
6 -44.69477 0.80002 1.7432 49.29
7 47.5051 1.35366
8 32.75877 3.82977 1.84666 23.78
9 -32.75877 Variable B
10 -24.76086 0.8 1.6516 58.55 (S-LAL7)
11 -153.4119 Variable C
12 ∞ 1.40078
13 18.96748 3.75245 1.51633 64.06
14 -24.25341 0.09999
15 18.77954 4.04255 1.51742 52.43
16 -18.77954 1.3999 1.834 37.16
17 18.77954 Variable D
18 22.71409 5.00033 1.58913 61.15
19 -20.0266 0.10002
20 56.47649 0.79994 1.90366 31.32
21 17.45296 Variable E
22 ∞ 0.70000 1.53770 66.60
23 ∞ 1.50000
24 ∞ 0.70000 1.50000 64.00
25 ∞.

"Aspherical data"
Aspherical data are shown below.

  The glass material for the third lens group is assumed to be “S-LAL7” manufactured by OHARA.

  Νd and θg, F of S-LAL7 are as follows from the published catalog.

νd = 58.55
θg, F = 0.5425.

"Variable amount"
Variable amounts of data are shown in Table 8.

  FIGS. 30 to 32 sequentially show aberration diagrams of Example 8 at the wide-angle end, the intermediate focal length, and the telephoto end.

"Example 9"
Example 9 is the zoom lens shown in FIG.

f = 16.19 to 45.75 F = 3.63 to 5.86 ω = 41.45 to 17.36
Surface number R D Nd νd
1 33.04630 1.30000 1.84666 23.78
2 24.61909 5.03061 1.69680 55.53
3 136.08670 Variable A
4 66.82379 0.97000 2.00100 29.13
5 10.13620 6.58248
6 -27.08140 0.80000 1.69350 53.18
7 42.28382 0.10000
8 36.12687 4.06747 1.84666 23.78
9 -23.91703 Variable B
10 -19.22723 0.80000 1.60300 65.44 (S-PHM53)
11 -40.79376 Variable C
12 ∞ (Aperture) 1.45000
13 15.53437 3.73586 1.51633 64.06
14 -28.31772 0.10000
15 26.51545 3.96987 1.53172 48.84
16 -16.08335 1.45000 1.83400 37.16
17 21.49926 Variable D
18 18.61811 5.28649 1.58913 61.15
19 -19.32644 0.10000
20 50.34422 0.82401 1.90366 31.32
21 15.67976 Variable E
22 ∞ 0.70000 1.53770 66.60
23 ∞ 1.50000
24 ∞ 0.70000 1.50000 64.00
25 ∞.

"Aspherical data"
The aspherical data is shown below.
6th page
K = 0
A4 = -2.62797E-05
A6 = 2.15039E-07
A8 = 1.25881E-09
A10 = -3.37339E-11
A12 = -5.96466E-14
7th page
K = 0
A4 = -6.94415E-05
A6 = 2.98647E-07
A8 = -1.81245E-09
A10 = -2.26671E-11
Side 13
K = 0
A4 = -1.84404E-05
A6 = -9.86481E-08
A8 = 1.21421E-09
A10 = -2.38227E-11
14th page
K = 0
A4 = 9.50545E-06
A6 = 8.22895E-08
A8 = -9.41319E-10
A10 = -1.57178E-11
A12 = 0
18th page
K = -4.00213
A4 = 5.35275E-06
A6 = -6.14576E-08
A8 = -3.35757E-09
A10 = 3.63892E-11
19th page
K = -0.0203
A4 = 4.11207E-05
A6 = 6.45731E-08
A8 = -4.12993E-09
A10 = 4.1149E-11
The glass material of the third lens group is assumed to be “S-PHM53” manufactured by OHARA.

  Νd and θg, F of S-PHM53 are as follows from the published catalog.

νd = 65.44
θg, F = 0.5401 <−1.2 × 10 ⁻³ · 65.44 + 0.62 = 0.5415.

"Variable amount"
Variable amounts of data are shown in Table 9.

  FIG. 34 to FIG. 36 sequentially show aberration diagrams of Example 9 at the wide-angle end, the intermediate focal length, and the telephoto end.

  Table 10 shows parameter values of the conditions (1) to (9) in each of the above Examples 1 to 9.

As shown in Table 10, the zoom lenses of Examples 1 to 9 also satisfy the conditions (1) to (8). Moreover, as is clear from each aberration diagram, the zoom lenses of Examples 1 to 9 are all
A wide-angle half-field angle of 41 degrees or more, a zoom ratio of about 2.8 to 3.3 times, sufficiently small aberration correction, a small size, and a high resolution image sensor exceeding 5 to 10 million pixels Has the resolution corresponding to

I First lens group
II Second lens group
III Third lens group
IV Fourth lens group
V 5th lens group
S Aperture stop

JP-A-3-228008 Japanese Patent No. 3716418 Japanese Patent No. 3397686 Japanese Patent No. 4401451 JP 2010-175594 A

Claims (8)

In order from the object side along the optical axis, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a negative refractive power, a fourth lens group having a positive refractive power, A fifth lens group having a positive refractive power, and a diaphragm disposed between the third lens group and the fourth lens group;
During zooming from the wide-angle end to the telephoto end, the distance between the first lens group and the second lens group is increased, the distance between the second lens group and the third lens group is increased, and the third lens group and the fourth lens are increased. All lens groups move so that the distance between the groups decreases and the distance between the fourth lens group and the fifth lens group decreases.
The third lens group is composed of one negative lens, and the negative lens is a negative meniscus lens having a concave surface facing the object side,
Focusing is performed by moving the third lens group in the optical axis direction.
The combined lateral magnification of the fourth lens group and the fifth lens group when the object distance is infinity at the wide angle end: β _{45 W} , and the fourth lens group and the fifth lens group when the object distance is infinity at the telephoto end. The combined lateral magnification of the lens group: β _45T is the condition:
(1) 2.0 <β _45T / β _45W <2.5
(2) −1.1 <β _{45 W} <−0.7
(3) -2.4 <β _45T <-1.8
A zoom lens characterized by satisfying The zoom lens according to claim 1.
Focal length of the fourth lens group: F4, focal length of the fifth lens group: F5, focal length at the wide angle end: Fw and focal length at the telephoto end: Ft geometric mean: Fm (= √ (Fw × Ft) ) But the condition:
(4) 1.0 <F4 / Fm <1.5
(5) 1.1 <F5 / Fm <1.8
A zoom lens characterized by satisfying The zoom lens according to claim 1 or 2,
When the object distance is infinity at the wide angle end, the lateral magnification of the third lens group: β _3W when the object distance is infinity, and when the object distance is infinity at the telephoto end, the lateral magnification: β _3T of the third lens group is:
(6) 0.7 <β _3T / β _3W <0.98
A zoom lens characterized by satisfying The zoom lens according to any one of claims 1 to 3,
The Abbe number vd of the material of the negative meniscus lens constituting the third lens group with the concave surface facing the object side is:
(7) vd> 50
A zoom lens characterized by satisfying The zoom lens according to any one of claims 1 to 4,
Maximum image height: Y ′, focal length at wide-angle end: Fw, focal length at telephoto end: Ft, focal length at wide-angle end: Fw
(8) 0.75 <Y '/ Fw
(9) 2.8 <Ft / Fw
A zoom lens characterized by satisfying   An information device having a photographing function, comprising the zoom lens according to any one of claims 1 to 5 as a photographing optical system. The information device according to claim 6.
An information device having a photographing function, wherein an object image formed by a zoom lens is formed on a light receiving surface of an image sensor. The information device according to claim 7, wherein
An information device having a photographing function, characterized by being configured as a portable information terminal device.

Images