JP2007003600A - Zoom lens and imaging apparatus having the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a zoom lens having good optical performance by satisfactorily correcting chromatic aberration.
A first lens group having a positive refractive power, a second lens group having a negative refractive power, and a rear group including one or more lens groups in order from the object side to the image side. In a zoom lens in which the distance between the first lens group and the second lens group changes,
The first lens group as a whole includes one or more negative lenses and one or more negative lenses and a positive lens, or a lens element in which the negative lens and the positive lens are arranged adjacent to each other with an air gap therebetween. Have a positive lens,
The Abbe number of the material of the bonded lens or the negative lens constituting the lens element is νd1n, and the difference of the partial dispersion ratio θgd of the material from the θgd standard line is Δθgd1n,
When the Abbe number of the material of the positive lens in the first lens group is νd1p,
νd1n <40
Δθgd1n <0.005
νd1p <75
Satisfy the following conditions.
[Selection] Figure 1

Description

  The present invention relates to a zoom lens and an image pickup apparatus having the same, and is suitable for an image pickup apparatus such as a digital camera, a video camera, and a silver salt film camera.

  In recent years, with the downsizing of an imaging apparatus, it is required that the entire system be downsized while maintaining high optical performance in an imaging optical system mounted thereon.

  In order to cope with a wider range of photographing conditions, it is desired that the photographing optical system is a zoom lens having a high zoom ratio (high zoom ratio).

  Among them, a so-called telephoto zoom lens including a long focal length that has a focal length at the telephoto end of about 200 to 300 mm in terms of 35 mm film size is in great demand because it can easily shoot in the telephoto range.

  For this reason, various telephoto zoom lenses have been proposed (Patent Documents 1 and 2).

  Patent Document 1 proposes a telephoto zoom lens having a large aperture ratio that is composed of four lens groups of positive, negative, positive, and positive refractive power in order from the object side to the image side and has a zoom ratio of about 3 times.

  Further, in Patent Document 2, a telephoto zoom lens having a high zoom ratio having a zoom ratio of about 4 is composed of six lens groups of positive, negative, positive, negative, positive, and negative refractive power in order from the object side to the image side. Has proposed.

  In such a telephoto zoom lens having a long focal length at the telephoto end, many axial chromatic aberrations and lateral chromatic aberrations are likely to occur particularly at the telephoto end. For this reason, in such a telephoto zoom lens, a lens element having a strong achromatic effect is arranged in a lens group in which the axial beam diameter at the telephoto end is increased and the height of the off-axis beam is also increased.

  In a general telephoto zoom lens having a telephoto type refractive power arrangement at the telephoto end, a lens element that performs strong achromaticity is arranged in a first lens group having a positive refractive power. In the first lens group, it is a general technique to perform achromaticity by combining a positive lens made of a glass material having a large Abbe number (small dispersion) and a negative lens made of a glass material having a small Abbe number (large dispersion). The greater the difference in Abbe number between the positive and negative lens materials in the first lens group, the higher the effect of correcting chromatic aberration.

  However, a material with a large Abbe number used for the material of the positive lens here becomes difficult to process the lens, especially when the Abbe number exceeds 80. In particular, the mechanical difficulty increases the processing difficulty and makes the manufacturing difficult.

  In addition, such a glass material has a relatively high glass material cost, and the cost of the optical system increases overall in addition to the high degree of processing difficulty.

Further, the axial light beam having the highest height from the optical axis passes through the first lens group in the telephoto zoom lens. For this reason, since each lens in the first lens group has the largest diameter in the optical system, it tends to be heavy.
JP-A-6-51202 Japanese Patent Laid-Open No. 7-261079

  Patent Document 1 is a zoom lens having a four-group configuration. Has a large aperture of about 2.8 and realizes good optical performance. However, since a glass material having an Abbe number exceeding 80 is frequently used as the material of the positive lens of the first lens group having the largest effective diameter in the optical system, the manufacturing tends to be very difficult.

  In Patent Document 2, a glass material having a large Abbe number is not used as the material of the positive lens in the first lens group. For this reason, there is still room for study on correction of chromatic aberration at the telephoto end.

  The present invention has a high optical performance with good correction of chromatic aberration by appropriately setting the lens configuration of the first lens group in a telephoto zoom lens having a telephoto type refractive power arrangement at the telephoto end. The purpose is to provide a zoom lens.

The zoom lens of the present invention is
In order from the object side to the image side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a rear group including one or more lens groups, and for zooming, the first lens group and In the zoom lens in which the interval of the second lens group changes,
The first lens group includes, as a whole, one or more negative lenses and one or more negative lenses and a positive lens, or a lens element in which the negative lens and the positive lens are arranged adjacent to each other with an air gap therebetween. Have a positive lens,
The Abbe number of the material of the bonded lens or the negative lens constituting the lens element is νd1n, and the difference of the partial dispersion ratio θgd of the material from the θgd standard line is Δθgd1n,
When the Abbe number of the material of the positive lens in the first lens group is νd1p,
νd1n <40 (1)
Δθgd1n <0.005 (2)
νd1p <75 (3)
It is characterized by satisfying the following conditions.

  According to the present invention, it is possible to obtain a zoom lens having excellent optical performance by satisfactorily correcting chromatic aberration.

  Embodiments of the zoom lens of the present invention and an image pickup apparatus having the same will be described below.

  FIG. 1 is a lens cross-sectional view at the wide-angle end (short focal length) of the zoom lens according to Embodiment 1 of the present invention, and FIGS. 2 and 3 are respectively at the wide-angle end and telephoto end (long focal length) of the zoom lens according to Embodiment 1. It is an aberration diagram.

  4 is a lens cross-sectional view at the wide-angle end of the zoom lens according to Embodiment 2 of the present invention. FIGS. 5 and 6 are aberration diagrams at the wide-angle end and telephoto end of the zoom lens according to Embodiment 2, respectively.

  FIG. 7 is a lens cross-sectional view at the wide-angle end of the zoom lens according to Embodiment 3 of the present invention. FIGS. 8 and 9 are aberration diagrams at the wide-angle end and telephoto end of the zoom lens according to Embodiment 3, respectively.

  FIG. 10 is a lens cross-sectional view at the wide-angle end of the zoom lens according to Embodiment 4 of the present invention, and FIGS. 11 and 12 are aberration diagrams at the wide-angle end and telephoto end of the zoom lens according to Embodiment 4, respectively.

  FIG. 13 is a schematic diagram of a main part of a camera (imaging device) including the zoom lens of the present invention. The zoom lens according to each embodiment is a photographing lens system used in an imaging device such as a video camera, a digital camera, and a silver salt film camera. (Rear). In the lens cross-sectional view, i indicates the order of the lens groups from the object side, and Li is the i-th lens group. SP is an aperture stop.

  IP is an image plane, and when used as a photographing optical system for a video camera or a digital still camera, on the imaging surface of a solid-state imaging device (photoelectric conversion device) such as a CCD sensor or a CMOS sensor, Corresponds to the film surface.

  In the aberration diagrams, d, g, C, and F are d-line, g-line, C-line, and F-line, respectively. dM and dS are the meridional image plane and sagittal image plane at the d line, and gM and gS are the meridional image plane and sagittal image plane at the g line, and the chromatic aberration of magnification is represented by the g line.

  Fno is the F number, and Y is the image height.

  In the following embodiments, the wide-angle end and the telephoto end refer to zoom positions when the zoom lens unit is positioned at both ends of a range in which the mechanism can move on the optical axis.

  In each embodiment, each lens group is moved as indicated by an arrow during zooming from the wide-angle end to the telephoto end.

  Next, the configuration of each embodiment will be specifically described.

  The zoom lens according to the first exemplary embodiment illustrated in FIG. 1 includes, in order from the object side to the image side, a first lens unit L1 having a positive refractive power, a second lens unit L2 having a negative refractive power, and a third lens unit L3 having a positive refractive power. The zoom lens includes an aperture stop SP that moves integrally with the third lens unit L3 during zooming, a fourth lens unit L4 having negative refractive power, a fifth lens unit L5 having positive refractive power, and a sixth lens unit L6 having negative refractive power. is doing.

  When zooming from the wide-angle end to the telephoto end, the distance between the first lens unit L1 and the second lens unit L2 is increased at the telephoto end compared to the wide-angle end, and the interval between the second lens L2 and the third lens unit L3 is decreased. The interval between the third lens unit L3 and the fourth lens unit L4 increases, the interval between the fourth lens unit L4 and the fifth lens unit L5 changes, and the interval between the fifth lens unit L5 and the sixth lens unit L6 decreases. The first lens unit L1, the third lens unit L3, and the sixth lens unit L6 move on the optical axis toward the object side, and the fifth lens unit L5 moves along a locus that draws a convex locus on the object side. Yes.

  During zooming, the second lens unit L2 and the fourth lens unit L4 do not move on the optical axis.

  At the wide-angle end, the combined focal length of the first lens unit L1 and the second lens unit L2 that are close to each other is negative, the combined focal length of the subsequent lens units is positive, and the entire lens system is close to a retrofocus type. It becomes refractive power arrangement.

  On the other hand, at the telephoto end, the combined focal length of the second lens unit L2 and the third lens unit L3 that are close to each other is negative, and the entire lens system has a substantially telephoto refractive power arrangement. Further, by moving the fifth lens unit L5 and the sixth lens unit L6 non-linearly during zooming, the image plane variation and the focal position variation at the time of zooming are corrected.

  Further, the sixth lens unit L6 disposed closest to the image plane is a lens unit having a negative refractive power, so that asymmetrical aberrations such as coma are corrected well.

  Further, the first lens unit L1 moves toward the object side from the wide-angle end toward the telephoto end, so that the wide-angle end side is in a retracted state, so that the total lens length is reduced when stored.

  With this configuration, the zoom lens according to the first exemplary embodiment realizes a telephoto zoom lens having a high zoom ratio of about 4 times and a compact lens system.

  In the configuration as described above, in the zoom lens of Example 1, the first lens unit L1 is further composed of one negative lens and two positive lenses, of which one negative lens and one positive lens. A cemented lens is configured.

  In order to correct chromatic aberration particularly at the telephoto end, particularly axial chromatic aberration, this cemented lens has a relatively small Abbe number (a large dispersion) material and a positive lens material. Using a material having a relatively large Abbe number (small dispersion), the first lens unit L1 having the highest axial luminous flux at the telephoto end is used for achromatization.

Further, in Example 1, the Abbe number of the material of the negative lens constituting the cemented lens is νd1n, the partial dispersion ratio θgd of the material is θgd, the difference in the partial dispersion ratio direction from the standard line is Δθgd1n, the first When the Abbe number of all the positive lens materials in the lens unit L1 is νd1p,
νd1n <40 (1)
Δθgd1n <0.005 (2)
νd1p <75 (3)
A material that satisfies the following conditions is used. This realizes an optical system having high optical performance while sufficiently correcting chromatic aberration.

Here, when the refractive indexes of the materials for the Fraunhofer g-line, d-line, F-line, and C-line are Ng, Nd, NF, and NC, respectively, the Abbe number νd and the partial dispersion ratio θgd are νd = (Nd− 1) / (NF-NC)
θgF = (Ng−Nd) / (NF−NC)
It is represented by

  Here, the difference in the value of the partial dispersion ratio θgd from the θgd standard line in the direction of the partial dispersion ratio (vertical axis) means that the Abbe number of the d-line of the material is νd and the partial dispersion ratio θgd as shown in FIG. When the vertical axis is θgd and the horizontal axis is νd, a line connecting the product name K7 (νd = 60.41, θgd = 1.238) and the product name F2 (νd = 36.37, θgd = 1.289) made by Schott Corporation with a straight line. This is the difference in the values in the vertical axis direction (partial dispersion ratio direction θgd) from the standard line SL when the standard line SL is used.

  Next, the technical meaning of the conditional expressions (1) to (3) will be described.

  Conditional expression (1) relates to the basic achromatic ability of the bonded lens. When the Abbe number of the negative lens material increases beyond the upper limit of conditional expression (1), the difference in Abbe number (difference difference) from the material of the positive lens to be achromatic with the combination lens becomes smaller and becomes the reference wavelength. Correction of chromatic aberration between two colors (for example, d line-g line or d line-F line) becomes difficult, which is not desirable.

  Conditional expression (2) relates to the achromatic ability other than between the two reference colors. If the partial dispersion ratio θgd of the negative lens material increases beyond the upper limit of conditional expression (2), it is not desirable because sufficient chromatic aberration correction over the entire visible range becomes difficult.

  Conditional expression (3) is a condition for facilitating the manufacture of the first lens unit L1. If at least one glass material with a large Abbe number exceeding the upper limit of conditional expression (3) is used as the material of the positive lens constituting the first lens unit L1, chromatic aberration is combined with conditional expressions (1) and (2). Although the correction capability is improved to the utmost limit, processing of the material becomes difficult, which is not desirable.

In the zoom lens of Example 1, the effective diameter of the first lens unit L1 is the largest, and it becomes difficult to process each lens constituting the first lens unit L1 with high accuracy.
Furthermore, glass materials having a large Abbe number exceeding the upper limit of (3) tend to have a relatively high specific gravity. For this reason, the deviation from the condition (3) leads to an increase in the weight of the first lens unit L1, and a large load is applied to a mechanical mechanism for holding and driving the first lens unit L1.
Further, a glass material having a large Abbe number exceeding the upper limit of (3) tends to be high in cost, and using such a glass material for the first lens group having a large effective diameter increases the cost and is not desirable.

  As described above, the zoom lens according to Example 1 is configured as described above, thereby realizing a telephoto zoom lens having sufficient optical performance by sufficiently correcting chromatic aberration.

  In Example 1, it is preferable that the following conditions are further satisfied. According to this, better optical performance can be obtained.

When the focal length of the first lens unit L1 is f1, and the focal length of the negative lens constituting the cemented lens in the first lens unit L1 is f1n,
0.6 <| f1n | / f1 <1.4 (4)
To satisfy the following conditions.

  Conditional expression (4) is a condition for performing a correction of chromatic aberration and other aberrations in a balanced manner. When the refractive power of the negative lens constituting the cemented lens becomes too strong exceeding the lower limit of conditional expression (4), various aberrations other than chromatic aberration such as spherical aberration increase, making it difficult to correct this. Further, if the refractive power of the negative lens becomes too weak beyond the upper limit, the chromatic aberration correction capability becomes weak, which is not good.

  Furthermore, in order to obtain good optical performance over the entire zoom range, when the focal length at the wide angle end of the entire lens system is fw and the focal length at the telephoto end is ft,

 It is good to satisfy the condition.

  Conditional expression (5) is a condition for improving the balance between the size of the entire optical system and the optical performance. If the refractive power of the first lens unit L1 exceeds the lower limit and becomes too strong, the occurrence of various aberrations such as spherical aberration at the telephoto end becomes large, and it is difficult to correct them. Further, if the refractive power of the first lens unit L1 becomes too weak beyond the upper limit, the zooming capability between the first lens unit L1 and the second lens unit L2 will be weakened. Is not good because it grows.

  Further, it is more preferable to set the numerical ranges of the conditional expressions (1) to (5) as follows.

νd1n <38 (1a)
Δθgd1n <0.003 (2a)
νd1p <72 (3a)
0.7 <| f1n | / f1 <1.2 (4a)

   In the zoom lens of Example 1, the image position is displaced by moving all or part of the second lens unit L2 so as to have a component perpendicular to the optical axis. For example, blurring of a captured image when the optical system vibrates is corrected.

  In general, when correcting image blur by correcting a part of the correction lens group of the optical system to be decentered parallel or rotationally so as to have a component perpendicular to the optical axis, the correction lens group is appropriately set from the optical system. If not set, the drive mechanism becomes large and the optical performance deteriorates. Further, if the image blur correction effect with respect to the eccentric movement of the correction lens group is small, it is necessary to increase the amount of movement of the correction lens group in order to obtain a sufficient image blur correction effect. As a result, the mechanical mechanism for correcting image blur becomes larger.

  On the other hand, if the image blur correction effect on the eccentric movement of the correction lens group is too strong, it is difficult to perform accurate lens movement control when correcting a certain image blur, or the eccentricity during image blur correction. This is not good because aberrations increase and optical performance deteriorates.

  In the zoom lens of Example 1, the second lens unit L2 is moved so as to have a component perpendicular to the optical axis by appropriately providing the refractive power arrangement of the second lens unit L2 and the third lens unit L3. Thus, the blur of the captured image when the optical system vibrates is corrected. In Example 1, when the focal length of the second lens unit L2 is f2, and the focal length of the third lens unit is f3,

 The conditions are satisfied.

  In the first embodiment, by satisfying these conditions (6) and (7), since the eccentric sensitivity is low, an excessive amount of eccentric movement is required at the time of image blur correction, or conversely, the eccentric sensitivity is too high. Control is not difficult.

This corrects image blur well.
Similarly to conditional expression (5), (6) and (7) are conditions for improving the balance between the overall size of the optical system and the optical performance. By satisfying (6) and (7), the refracting power of the first lens group, the second lens group, and the third lens group, which is responsible for most of the zooming action, is made to have a more suitable balance and a high zooming ratio. It achieves good optical performance with a compact optical system.

  The zoom lens of Example 2 shown in FIG. 4 has the first lens unit L1 having positive refractive power, the second lens unit L2 having negative refractive power, and the positive refractive power in order from the object side to the image side in the same manner as Example 1. The third lens unit L3, the aperture stop SP that moves integrally with the third lens unit, the fourth lens unit L4 with negative refractive power, the fifth lens unit L5 with positive refractive power, and the sixth lens unit with negative refractive power. L6.

  In the zoom lens of Example 2, the first lens unit L1 includes one negative lens and two positive lenses. Among them, one negative lens and one positive lens are arranged adjacent to each other with a minute air gap to constitute a lens element L1a. This lens element L1a constitutes an achromatic lens system.

  The negative lens constituting the lens element L1a corresponds to the negative lens of the cemented lens in the first lens unit L1 of Example 1.

  This achromatic lens system L1a has a relatively small Abbe number (a large dispersion) material for a negative lens and a relatively small material for a positive lens in order to satisfactorily correct chromatic aberration at the telephoto end, particularly axial chromatic aberration. A material with a large Abbe number (small dispersion) is used. Then, the achromatic lens system L1a is provided in the first lens unit L1 in which the axial light beam at the telephoto end is the highest, so that the achromaticity is favorably performed.

  Other movements of the lens units during zooming, conditions relating to conditional expressions (1) to (7), and all or part of the second lens unit L2 are moved so as to have a component perpendicular to the optical axis. The correction of the blurring of the captured image when the vibration is applied to the optical system is the same as in the first embodiment.

  This realizes a telephoto zoom lens that can sufficiently correct chromatic aberration and obtain good optical performance.

  The zoom lens according to the third exemplary embodiment illustrated in FIG. 7 includes, in order from the object side to the image side, a first lens unit L1 having a positive refractive power, a second lens unit L2 having a negative refractive power, and a third lens unit L3 having a positive refractive power. The aperture stop SP moves integrally with the third lens unit, the fourth lens unit L4 with positive refractive power, and the fifth lens unit L5 with negative refractive power.

  During zooming from the wide-angle end to the telephoto end, the interval between the first lens unit L1 and the second lens unit L2 increases, the interval between the second lens unit L2 and the third lens unit L3 decreases, and the third lens unit L3 and the fourth lens unit. The first lens unit L1, the third lens unit L3, and the fifth lens unit L5 are on the optical axis as shown by arrows so that the interval between the group L4 increases and the interval between the fourth lens unit L4 and the fifth lens unit L5 decreases. Is moving to the object side.

  At the wide-angle end, the combined focal length of the first lens unit L1 and the second lens unit L2 that are close to each other is negative, the combined focal length of the subsequent lens units is positive, and the entire lens system is close to a retrofocus type. It becomes refractive power arrangement.

  On the other hand, at the telephoto end, the combined focal length of the second lens unit L2 and the third lens unit L3 that are close to each other is negative, and the entire lens system has a substantially telephoto refractive power arrangement. Further, the fifth lens unit L5 arranged closest to the image surface side has a negative refractive power, so that asymmetrical aberrations such as coma are corrected well.

  Further, the first lens unit L1 moves toward the object side during zooming from the wide-angle end to the telephoto end, so that the entire lens length becomes compact when retracted with the wide-angle end side retracted.

  By adopting such a configuration, in the third embodiment, a compact telephoto zoom lens having a zoom ratio of about 3.3 times is realized.

  In the configuration as described above, in the zoom lens of Example 3, the first lens unit L1 is configured by one negative lens and two positive lenses.

  Of these, one negative lens and one positive lens constitute a bonded lens. In order to correct chromatic aberration particularly at the telephoto end, particularly axial chromatic aberration, this cemented lens has a relatively small Abbe number (large dispersion) material for a negative lens and a relatively large Abbe number for a positive lens. A material with a large (low dispersion) is used. In Example 3, good achromaticity is performed by the first lens unit L1 in which the axial light beam at the telephoto end is the highest.

  Other conditions relating to the conditional expressions (1) to (7) are the same as those in the first embodiment, thereby realizing a telephoto zoom lens capable of sufficiently correcting chromatic aberration and obtaining good optical performance.

  The zoom lens according to the fourth exemplary embodiment illustrated in FIG. 10 includes, in order from the object side to the image side, a first lens unit L1 having a positive refractive power, a second lens unit L2 having a negative refractive power, and a third lens unit L3 having a positive refractive power. And an aperture stop SP and a fourth lens unit L4 having a positive refractive power.

  During zooming from the wide-angle end to the telephoto end, the interval between the first lens unit L1 and the second lens unit L2 increases, the interval between the second lens unit L2 and the third lens unit L3 decreases, and the third lens unit L3 and the fourth lens unit. The first lens unit L1 and the third lens unit L3 are moved to the object side on the optical axis, and the second lens unit L2 is moved to the image plane side on the optical axis so that the interval between the groups L4 is increased. .

  At the wide-angle end, the combined focal length of the first lens unit L1 and the second lens unit L2 that are close to each other is negative, the combined focal length of the subsequent lens units is positive, and the entire lens system is close to a retrofocus type. It becomes refractive power arrangement.

  On the other hand, at the telephoto end, the combined focal length of the second lens unit L2 and the third lens unit L3 that are close to each other is negative, and the entire lens system has a substantially telephoto refractive power arrangement. Further, by zooming from the wide angle end to the telephoto end, the first lens unit L1 moves toward the object side, so that the wide angle end side is in the retracted state, and the total length of the lens is reduced when stored.

  By adopting such a configuration, the zoom lens of Embodiment 4 realizes a compact telephoto zoom lens having a zoom ratio of about 3 times.

  In the above-described configuration, in the zoom lens according to the fourth exemplary embodiment, the first lens L1 group is further configured by one negative lens and two positive lenses. Of these, one negative lens and one positive lens constitute a bonded lens. In order to correct chromatic aberration particularly at the telephoto end, particularly axial chromatic aberration, this cemented lens has a relatively small Abbe number (large dispersion) material for a negative lens and a relatively large Abbe number for a positive lens. A material with a large (low dispersion) is used.

  In Example 4, the first lens unit L1 in which the axial light beam at the telephoto end is the highest is achromatic.

  Other conditions relating to the conditional expressions (1) to (7) are the same as those in the first embodiment, thereby realizing a telephoto zoom lens capable of sufficiently correcting chromatic aberration and obtaining good optical performance.

  Numerical examples 1 to 4 corresponding to the first to fourth examples are shown below. In each numerical example, i indicates the order of the surfaces from the object side, ri is the radius of curvature of each surface, di is the member thickness or air spacing between the i-th surface and the i + 1-th surface, and ni and νi are Refractive index and Abbe number based on d line are shown.

  f represents a focal length, Fno represents an F number, and ω represents a half angle of view. Table 1 shows the relationship between the above-described conditional expressions and numerical values in the numerical examples.

Numerical example 1

f = 72.4 ~ 290.0 FNo = 1: 4.1 ~ 5.9 2ω = 33.3 ° ~ 8.5 °

r 1 = 275.795 d 1 = 2.60 n 1 = 1.74950 ν 1 = 35.3
r 2 = 67.272 d 2 = 6.85 n 2 = 1.48749 ν 2 = 70.2
r 3 = -602.521 d 3 = 0.20
r 4 = 84.363 d 4 = 6.15 n 3 = 1.51633 ν 3 = 64.1
r 5 = -263.696 d 5 = variable
r 6 = -137.771 d 6 = 1.40 n 4 = 1.71300 ν 4 = 53.9
r 7 = 64.798 d 7 = 3.64
r 8 = -41.270 d 8 = 1.10 n 5 = 1.60311 ν 5 = 60.6
r 9 = 61.128 d 9 = 2.90 n 6 = 1.84666 ν 6 = 23.9
r10 = -366.719 d10 = variable
r11 = 60.128 d11 = 4.60 n 7 = 1.49700 ν 7 = 81.5
r12 = -73.825 d12 = 0.20
r13 = 59.578 d13 = 4.70 n 8 = 1.48749 ν 8 = 70.2
r14 = -59.578 d14 = 1.50 n 9 = 1.83400 ν 9 = 37.2
r15 = 0.000 d15 = 4.40
r16 = 0.000 (aperture) d16 = variable
r17 = -55.580 d17 = 2.80 n10 = 1.51633 ν10 = 64.1
r18 = -122.975 d18 = variable
r19 = 155.000 d19 = 4.40 n11 = 1.60311 ν11 = 60.6
r20 = -39.321 d20 = 1.80 n12 = 1.80518 ν12 = 25.4
r21 = -76.835 d21 = 0.20
r22 = 63.185 d22 = 2.80 n13 = 1.58913 ν13 = 61.1
r23 = 0.000 d23 = variable
r24 = -47.006 d24 = 1.50 n14 = 1.77250 ν14 = 49.6
r25 = 43.075 d25 = 2.90 n15 = 1.80518 ν15 = 25.4
r26 = 180.000 d26 = variable

Focal length 72.40 134.99 290.00
Variable interval
d 5 5.14 35.87 59.54
d 10 30.37 20.07 2.86
d 16 4.31 14.62 31.82
d 18 23.91 17.65 16.93
d 23 19.91 14.64 3.38


Numerical example 2

f = 72.4 ~ 290.0 FNo = 1: 4.1 ~ 5.9 2ω = 33.3 ° ~ 8.5 °

r 1 = 364.109 d 1 = 2.60 n 1 = 1.74950 ν 1 = 35.3
r 2 = 65.920 d 2 = 0.30
r 3 = 66.511 d 3 = 6.83 n 2 = 1.51633 ν 2 = 64.1
r 4 = -515.378 d 4 = 0.20
r 5 = 83.489 d 5 = 6.55 n 3 = 1.51633 ν 3 = 64.1
r 6 = -255.230 d 6 = variable
r 7 = -105.609 d 7 = 1.40 n 4 = 1.77250 ν 4 = 49.6
r 8 = 72.088 d 8 = 3.17
r 9 = -46.157 d 9 = 1.10 n 5 = 1.60311 ν 5 = 60.6
r10 = 65.363 d10 = 3.17 n 6 = 1.84666 ν 6 = 23.9
r11 = -276.995 d11 = variable
r12 = 59.654 d12 = 4.59 n 7 = 1.48749 ν 7 = 70.2
r13 = -70.940 d13 = 0.20
r14 = 61.369 d14 = 4.68 n 8 = 1.48749 ν 8 = 70.2
r15 = -61.369 d15 = 1.50 n 9 = 1.83400 ν 9 = 37.2
r16 = -611138.495 d16 = 4.40
r17 = 0.000 (aperture) d17 = variable
r18 = -55.662 d18 = 2.80 n10 = 1.60311 ν10 = 60.6
r19 = -109.294 d19 = variable
r20 = 148.960 d20 = 5.22 n11 = 1.60311 ν11 = 60.6
r21 = -35.509 d21 = 1.80 n12 = 1.80518 ν12 = 25.4
r22 = -72.804 d22 = 0.20
r23 = 57.580 d23 = 3.71 n13 = 1.60311 ν13 = 60.6
r24 = 634.684 d24 = variable
r25 = -51.703 d25 = 1.50 n14 = 1.77250 ν14 = 49.6
r26 = 32.936 d26 = 3.22 n15 = 1.80518 ν15 = 25.4
r27 = 103.784 d27 = variable

Focal length 72.40 135.00 290.00
Variable interval
d 6 4.60 35.16 59.56
d 11 28.53 18.74 2.63
d 17 4.02 13.80 29.92
d 19 27.34 20.59 20.63
d 24 20.54 15.15 3.75


Numerical Example 3

f = 92.7 ~ 291.0 FNo = 1: 4.7 ~ 5.9 2ω = 26.3 ° ~ 8.5 °

r 1 = 82.393 d 1 = 5.72 n 1 = 1.48749 ν 1 = 70.2
r 2 = 638.263 d 2 = 0.15
r 3 = 79.489 d 3 = 2.40 n 2 = 1.74950 ν 2 = 35.3
r 4 = 44.991 d 4 = 8.26 n 3 = 1.48749 ν 3 = 70.2
r 5 = 580.665 d 5 = variable
r 6 = -116.792 d 6 = 1.30 n 4 = 1.80610 ν 4 = 40.9
r 7 = 24.209 d 7 = 1.70
r 8 = 27.331 d 8 = 4.34 n 5 = 1.80518 ν 5 = 25.4
r 9 = 143.045 d 9 = variable
r10 = 0.000 (aperture) d10 = 12.76
r11 = 224.007 d11 = 1.30 n 6 = 1.80518 ν 6 = 25.4
r12 = 53.164 d12 = 4.24 n 7 = 1.48749 ν 7 = 70.2
r13 = -35.991 d13 = variable
r14 = -69.865 d14 = 3.78 n 8 = 1.51633 ν 8 = 64.1
r15 = -22.408 d15 = 1.30 n 9 = 1.80 100 ν 9 = 35.0
r16 = -48.518 d16 = 0.15
r17 = 44.607 d17 = 3.01 n10 = 1.58267 ν10 = 46.4
r18 = -101.880 d18 = variable
r19 = -240.384 d19 = 1.20 n11 = 1.72916 ν11 = 54.7
r20 = 33.006 d20 = 1.79
r21 = -207.584 d21 = 1.20 n12 = 1.69680 ν12 = 55.5
r22 = 32.601 d22 = 2.77 n13 = 1.78472 ν13 = 25.7
r23 = 424.104 d23 = variable

Focal length 92.72 134.90 290.99
Variable interval
d 5 11.59 30.16 58.60
d 9 29.01 19.89 5.00
d 13 0.60 9.72 24.61
d 18 23.05 18.23 0.70


Numerical Example 4

f = 102.0 to 291.0 FNo = 1: 5.8 to 5.8 2ω = 23.9 ° to 8.5 °

r 1 = 0.000 d 1 = 0.00
r 2 = 184.271 d 2 = 2.90 n 1 = 1.74950 ν 1 = 35.3
r 3 = 64.422 d 3 = 6.13 n 2 = 1.51633 ν 2 = 64.1
r 4 = 753.995 d 4 = 0.20
r 5 = 88.607 d 5 = 6.78 n 3 = 1.51633 ν 3 = 64.1
r 6 = -358.550 d 6 = variable
r 7 = -147.867 d 7 = 1.50 n 4 = 1.71300 ν 4 = 53.9
r 8 = 65.540 d 8 = 2.73
r 9 = -73.654 d 9 = 1.52 n 5 = 1.69680 ν 5 = 55.5
r10 = 39.689 d10 = 3.72 n 6 = 1.80518 ν 6 = 25.4
r11 = 356.812 d11 = variable
r12 = 105.917 d12 = 5.86 n 7 = 1.51742 ν 7 = 52.4
r13 = -30.387 d13 = 2.10 n 8 = 1.80518 ν 8 = 25.4
r14 = -56.123 d14 = variable
r15 = 0.000 (aperture) d15 = 1.90
r16 = 24.798 d16 = 8.79 n 9 = 1.61800 ν 9 = 63.3
r17 = -86.499 d17 = 1.52 n10 = 1.80400 ν10 = 46.6
r18 = 50.399 d18 = 4.97
r19 = 45.126 d19 = 1.94 n11 = 1.83400 ν11 = 37.2
r20 = 19.821 d20 = 6.15 n12 = 1.57099 ν12 = 50.8
r21 = 86.452 d21 = 3.07
r22 = 98.479 d22 = 4.15 n13 = 1.67270 ν13 = 32.1
r23 = -43.697 d23 = 5.25
r24 = -21.346 d24 = 1.68 n14 = 1.71300 ν14 = 53.9
r25 = 25.633 d25 = 4.93 n15 = 1.60311 ν15 = 60.6
r26 = -130.999 d26 = variable

Focal length 102.01 140.76 291.00
Variable interval
d 6 11.18 34.89 67.19
d 11 34.96 28.05 1.20
d 14 5.88 3.08 11.64

  Next, an embodiment in which the zoom lens shown in Embodiments 1 to 4 is applied to an imaging apparatus will be described with reference to FIG.

  FIG. 13 is a schematic view of the main part of a single-lens reflex camera. In FIG. 13, reference numeral 10 denotes a photographing lens having the zoom lens 1 according to the first to fourth embodiments.

  The zoom lens 1 is held by a lens barrel 2 that is a holding member. Reference numeral 20 denotes a camera body, which includes a quick return mirror 3 that reflects the light beam from the photographing lens 10 upward, a focusing plate 4 that is disposed at an image forming position of the photographing lens 10, and an inverted image formed on the focusing plate 4. It is composed of a penta roof prism 5 for converting to an eyepiece, an eyepiece 6 for observing the erect image, and the like.

  Reference numeral 7 denotes a photosensitive surface, on which a solid-state imaging device (photoelectric conversion device) such as a CCD sensor or a CMOS sensor, or a silver salt film is disposed.

  At the time of photographing, the quick return mirror 3 is retracted from the optical path, and an image is formed on the photosensitive surface 7 by the photographing lens 10.

  The benefits described in the first to fourth embodiments are effectively enjoyed in the optical apparatus disclosed in the present embodiment.

Lens cross-sectional view at the wide-angle end of the zoom lens of Example 1 Various aberration diagrams at the wide-angle end of the zoom lens of Example 1 Various aberration diagrams at the telephoto end of the zoom lens of Example 1 Lens sectional view at the wide-angle end of the zoom lens according to Embodiment 2 Various aberration diagrams at the wide-angle end of the zoom lens of Example 2 Various aberration diagrams at the telephoto end of the zoom lens of Example 2 Lens sectional view at the wide-angle end of the zoom lens according to Embodiment 3 Various aberration diagrams at the wide-angle end of the zoom lens of Example 3 Various aberration diagrams at the telephoto end of the zoom lens of Example 3 Lens sectional view at the wide-angle end of the zoom lens according to Embodiment 4 Various aberration diagrams at the wide-angle end of the zoom lens of Example 4 Various aberration diagrams at the telephoto end of the zoom lens of Example 4 Schematic diagram of main parts of an imaging apparatus of the present invention Illustration of standard line of partial dispersion ratio θgd

Explanation of symbols

L1 1st lens group L2 2nd lens group L3 3rd lens group L4 4th lens group L5 5th lens group L6 6th lens group LR Rear group SP Aperture IP Image plane d d line g g line dM d line meridional image Surface dS Sagittal image plane of d-line gM Meridional image plane of g-line gS Sagittal image plane of g-line Fno F number 1 Zoom lens 2 Lens barrel 10 Shooting lens 20 Camera body

Claims (11)

In order from the object side to the image side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a rear group including one or more lens groups, and for zooming, the first lens group and In the zoom lens in which the interval of the second lens group changes,
The first lens group includes, as a whole, one or more negative lenses and one or more negative lenses and a positive lens, or a lens element in which the negative lens and the positive lens are arranged adjacent to each other with an air gap therebetween. Have a positive lens,
The Abbe number of the material of the bonded lens or the negative lens constituting the lens element is νd1n, and the difference of the partial dispersion ratio θgd of the material from the θgd standard line is Δθgd1n,
When the Abbe number of the material of the positive lens in the first lens group is νd1p,
νd1n <40
Δθgd1n <0.005
νd1p <75
A zoom lens characterized by satisfying the following conditions: When the focal length of the first lens group is f1, and the focal length of the bonded lens in the first lens group or the negative lens constituting the lens element is f1n,
0.6 <| f1n | / f1 <1.4
The zoom lens according to claim 1, wherein the following condition is satisfied. When the focal length of the first lens group is f1, and the focal lengths at the wide-angle end and the telephoto end of the entire system are fw and ft, respectively.
The zoom lens according to claim 1, wherein the following condition is satisfied.   4. The zoom lens according to claim 1, wherein the first lens unit is moved so that a distance between the first lens unit and the second lens unit at a telephoto end is larger than that at a wide angle end during zooming. Zoom lens.   In order from the object side to the image side, the rear group includes a third lens group having a positive refractive power, a fourth lens group having a negative refractive power, a fifth lens group having a positive refractive power, and a sixth lens having a negative refractive power. The zoom lens according to claim 1, comprising a group.   5. The rear lens group includes a third lens group having a positive refractive power and a fourth lens group having a positive refractive power in order from the object side to the image side. 6. Zoom lens.   The rear group includes, in order from the object side to the image side, a third lens group having a positive refractive power, a fourth lens group having a positive refractive power, and a fifth lens group having a negative refractive power. 5. The zoom lens according to any one of 1 to 4. When the focal lengths of the second and third lens groups are f2 and f3, respectively, and the focal lengths at the wide-angle end and the telephoto end of the entire system are fw and ft, respectively.
The zoom lens according to claim 5, 6 or 7, wherein the following condition is satisfied.   The imaging position is corrected by moving the entire second lens group or a part of the second lens group so as to have a component in a direction substantially perpendicular to the optical axis. 9. The zoom lens according to any one of 8 above.   The zoom lens according to claim 1, wherein an image is formed on a solid-state image sensor.   11. An image pickup apparatus comprising: the zoom lens according to claim 1; and a solid-state image pickup device that receives an image formed by the zoom lens.