JPWO2019220629A1 - Zoom lens and optical equipment - Google Patents

Abstract

The zoom lens ZL includes a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a third lens group G3 having a positive refractive power arranged in order from the object side. The fourth lens group G4 having a negative refractive power and the fifth lens group G5 having a positive refractive power are provided, and the distance between adjacent lens groups changes at the time of magnification change. I am satisfied. 13.00 <f1 / (-f2) However, f1: Focal length of the first lens group f2: Focal length of the second lens group

Description

The present invention relates to a zoom lens, an optical device using the zoom lens, and a method for manufacturing the zoom lens.

Conventionally, 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 positive refractive power, and a negative refractive power. A zoom lens composed of a fourth lens group and a fifth lens group having a positive refractive power and moving each lens group to perform variable magnification has been proposed (see, for example, Patent Document 1). In the conventional zoom lens, further high magnification is required.

Japanese Unexamined Patent Publication No. 2013-164455

The first zoom lens according to the present invention includes a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a positive refractive power arranged in order from the object side. It has a lens group, a fourth lens group having a negative refractive power, and a fifth lens group having a positive refractive power, and the distance between adjacent lens groups changes at the time of magnification change. To be satisfied.

13.00 <f1 / (-f2)
However, f1: the focal length of the first lens group f2: the focal length of the second lens group

The second zoom lens according to the present invention includes a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a third lens group having a positive refractive power arranged in order from the object side. It has a lens group, a fourth lens group having a negative refractive power, and a fifth lens group having a positive refractive power, and the distance between adjacent lens groups changes at the time of magnification change. To be satisfied.

33.00 <f1 / fw <50.00
However, fw: the focal length of the entire zoom lens system in the wide-angle end state f1: the focal length of the first lens group.

The optical device according to the present invention is configured by mounting the first and second zoom lenses according to the present invention.

The first method for manufacturing a zoom lens according to the present invention is to combine a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a positive refractive power arranged in order from the object side. A third lens group having a third lens group, a fourth lens group having a negative refractive power, and a fifth lens group having a positive refractive power are arranged in a lens barrel, and the distance between adjacent lens groups is increased at the time of magnification change. It is configured to change and satisfy the following conditional expression.

13.00 <f1 / (-f2)
However, f1: the focal length of the first lens group f2: the focal length of the second lens group

The second method for manufacturing a zoom lens according to the present invention is to obtain a first lens group having a positive refractive power, a second lens group having a negative refractive power, and a positive refractive power arranged in order from the object side. A third lens group having a third lens group, a fourth lens group having a negative refractive power, and a fifth lens group having a positive refractive power are arranged in a lens barrel, and the distance between adjacent lens groups is increased at the time of magnification change. It is configured to change and satisfy the following conditional expression.

33.00 <f1 / fw <50.00
However, fw: the focal length of the entire zoom lens system in the wide-angle end state f1: the focal length of the first lens group.

It is sectional drawing which shows the lens structure of the zoom lens which concerns on 1st Example. It is sectional drawing which shows the lens structure of the zoom lens which concerns on 1st Example, (W) shows a wide-angle end state, (M) shows an intermediate focal length state, (T) shows the position of each lens group in a telephoto end state. .. 3 (A), 3 (B), and 3 (C) are aberration diagrams of the zoom lens according to the first embodiment in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively. It is sectional drawing which shows the lens structure of the zoom lens which concerns on 2nd Example. It is sectional drawing which shows the lens structure of the zoom lens which concerns on 2nd Example, (W) shows a wide-angle end state, (M) shows an intermediate focal length state, (T) shows the position of each lens group in a telephoto end state. .. 6 (A), 6 (B), and 6 (C) are aberration diagrams of the zoom lens according to the second embodiment in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively. It is sectional drawing which shows the lens structure of the zoom lens which concerns on 3rd Example. It is sectional drawing which shows the lens structure of the zoom lens which concerns on 3rd Example, (W) shows a wide-angle end state, (M) shows an intermediate focal length state, (T) shows the position of each lens group in a telephoto end state. .. 9 (A), 9 (B), and 9 (C) are aberration diagrams of the zoom lens according to the third embodiment in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively. It is sectional drawing which shows the lens structure of the zoom lens which concerns on 4th Example. It is sectional drawing which shows the lens structure of the zoom lens which concerns on 4th Example, (W) shows the position of each lens group in a wide-angle end state, (M) shows an intermediate focal length state, and (T) shows the position of each lens group in a telephoto end state. .. 12 (A), 12 (B), and 12 (C) are aberration diagrams of the zoom lens according to the fourth embodiment in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively. It is sectional drawing which shows the lens structure of the zoom lens which concerns on 5th Example. It is sectional drawing which shows the lens structure of the zoom lens which concerns on 5th Example, (W) shows a wide-angle end state, (M) shows an intermediate focal length state, (T) shows the position of each lens group in a telephoto end state. .. 15 (A), 15 (B), and 15 (C) are aberration diagrams of the zoom lens according to the fifth embodiment in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively. It is sectional drawing which shows the lens structure of the zoom lens which concerns on 6th Example. It is sectional drawing which shows the lens structure of the zoom lens which concerns on 6th Example, (W) shows a wide-angle end state, (M) shows an intermediate focal length state, (T) shows the position of each lens group in a telephoto end state. .. 18 (A), 18 (B), and 18 (C) are aberration diagrams of the zoom lens according to the sixth embodiment in the wide-angle end state, the intermediate focal length state, and the telephoto end state, respectively. It is the schematic which shows the structure of the camera provided with the zoom lens which concerns on 1st and 2nd Embodiment. It is a flowchart which shows the outline of the manufacturing method of the zoom lens which concerns on 1st and 2nd Embodiment.

Hereinafter, the first and second embodiments will be described with reference to the drawings. FIG. 19 shows a camera (optical device) provided with the zoom lens ZL according to the first and second embodiments. In addition, although the term "lens component" may be used in the present specification, in this case, the lens component is used as a term meaning "single lens or junction lens".

As shown in FIG. 19, the camera 1 is a digital camera including the zoom lens ZL according to the first and second embodiments as the photographing lens 2. In the camera 1, the light from an object (subject) (not shown) is collected by the photographing lens 2 and reaches the image sensor 3. As a result, the light from the subject is captured by the image sensor 3 and recorded as a subject image in a memory (not shown). In this way, the photographer can shoot the subject with the camera 1. This camera may be a mirrorless camera or a single-lens reflex type camera having a quick return mirror.

As shown in FIG. 1, the zoom lens ZL (1) as an example of the zoom lens ZL according to the first embodiment includes a first lens group G1 having a positive refractive power arranged in order from the object side and a negative lens group G1. A second lens group G2 having a refractive power, a third lens group G3 having a positive refractive power, a fourth lens group G4 having a negative refractive power, and a fifth lens group G5 having a positive refractive power. At the time of magnification change, the distance between adjacent lens groups changes.

The zoom lens ZL according to the first embodiment is shown in the zoom lens ZL (2) shown in FIG. 4, the zoom lens ZL (3) shown in FIG. 7, the zoom lens ZL (4) shown in FIG. 10, and FIG. The zoom lens ZL (5) or the zoom lens ZL (6) shown in FIG. 16 may be used.

The zoom lens ZL according to the first embodiment satisfies the following conditional expression (9) under the above configuration.

13.00 <f1 / (-f2) ... (1)
However, f1: focal length of the first lens group G1 f2: focal length of the second lens group G2

By configuring the zoom lens ZL according to the first embodiment as described above, high magnification can be achieved. According to the camera 1 provided with the zoom lens ZL according to the second embodiment as the photographing lens 2, it is possible to realize a camera having good optical performance while having a high magnification.

The conditional expression (1) is a conditional expression for reducing spherical aberration, astigmatism, and chromatic aberration. When the refractive power of the first lens group G1 becomes too large and falls below the lower limit of the conditional equation (1), it is advantageous for miniaturization, but it becomes difficult to correct spherical aberration and chromatic aberration of magnification in the telephoto end state. Become. Further, when the refractive power of the second lens group G2 becomes too small and falls below the lower limit of the conditional expression (1), the overall length is increased in order to secure a high magnification ratio. Here, in order to maintain the miniaturization of the optical system, the refractive power of the first lens group G1 must be increased, and the spherical aberration in the telephoto end state is deteriorated.

In order to ensure the effect of the first embodiment, it is more preferable that the lower limit of the conditional expression (1) is 13.30, and more preferably 13.60, 13.90, 14.20. In order to ensure the effect of the first embodiment, the upper limit of the conditional expression (1) is set to 25.00, and further set to 23.00, 20.00, 19.00, 18.00, 17.00. Is more preferable. By satisfying the conditional expression (1) provided with such an upper limit value, spherical aberration, astigmatism and chromatic aberration become smaller, which is preferable.

In the zoom lens ZL according to the first embodiment, it is preferable that the first lens group G1 moves toward the object when at least a part of the magnification is changed from the wide-angle end state to the telephoto end state. With this configuration, it is possible to achieve a high magnification with a small size.

In the zoom lens ZL according to the first embodiment, the distance between the first lens group G1 and the second lens group G2 is expanded when at least a part of the magnification is changed from the wide-angle end state to the telescopic end state, and the second lens group G2 It is preferable that the distance between the third lens group G3 and the third lens group G3 is reduced and the distance between the third lens group G3 and the fourth lens group G4 is increased. With this configuration, it is possible to achieve a high magnification with a small size.

In the zoom lens ZL according to the first embodiment, it is preferable that the first lens group G1, the second lens group G2, the third lens group G3, and the fourth lens group G4 move along the optical axis at the time of magnification change. With this configuration, it is possible to achieve a high magnification with a small size.

In the zoom lens ZL according to the first embodiment, it is preferable that the fifth lens group G5 moves along the optical axis at the time of scaling. With this configuration, it is possible to achieve a high magnification with a small size.

In the zoom lens ZL according to the first embodiment, it is preferable that at least one lens surface of the third lens group G3 has an aspherical surface. With this configuration, it is possible to satisfactorily correct various aberrations such as spherical aberration and coma aberration with a small size.

In the zoom lens ZL according to the first embodiment, it is preferable that the first lens group G1 is composed of four lenses. With this configuration, it is possible to satisfactorily correct various aberrations such as spherical aberration and coma aberration with a small size.

The zoom lens ZL according to the first embodiment preferably has a fourth lens group G4 composed of two or less lenses. With this configuration, it is possible to satisfactorily correct various aberrations such as spherical aberration and coma aberration with a small size.

The zoom lens ZL according to the first embodiment preferably has a fifth lens group G5 composed of two or less lenses. With this configuration, it is possible to satisfactorily correct various aberrations such as spherical aberration and coma aberration with a small size.

In the zoom lens ZL according to the first embodiment, it is preferable that at least one lens surface of the fifth lens group G5 has an aspherical surface. With this configuration, it is possible to satisfactorily correct various aberrations such as spherical aberration and coma aberration with a small size.

In the zoom lens ZL according to the first embodiment, it is preferable that the fourth lens group G4 moves along the optical axis at the time of focusing. With this configuration, fluctuations in various aberrations such as spherical aberration and coma during focusing can be reduced. At the time of focusing, at least a part of the fourth lens group G4 may move along the optical axis.

In the zoom lens ZL according to the first embodiment, it is preferable that the third lens group G3 has at least a part of a vibration-proof lens group that can be moved so as to have a displacement component in a direction perpendicular to the optical axis. With this configuration, it is possible to reduce fluctuations in various aberrations such as coma during image stabilization. The anti-vibration lens group may be the entire third lens group G3, any lens constituting the third lens group G3, or a combination thereof. For example, the positive lens on the most object side of the third lens group G3 or the junction lens on the most image side of the third lens group G3 may form the anti-vibration lens group.

The zoom lens ZL according to the first embodiment preferably satisfies the following conditional expression (3).
10.00 <Dt12 / (-f2) ... (3)
However, Dt12: the distance on the optical axis from the image side surface of the first lens group G1 to the object side surface of the second lens group G2 in the telephoto end state.

The conditional expression (3) is a conditional expression for reducing spherical aberration, chromatic aberration of magnification, and axial chromatic aberration to ensure good optical performance. When the value is lower than the lower limit of the conditional expression (3), the distance between the first lens group G1 and the second lens group G2 in the telephoto end state becomes significantly smaller, so that the refraction of the first lens group G1 and the second lens group G2 The power becomes too great. When the refractive power of the first lens group G1 becomes large, it becomes difficult to correct spherical aberration and chromatic aberration of magnification, especially in the telephoto end state. When the refractive power of the second lens group G2 becomes large, it becomes difficult to correct the axial chromatic aberration.

In order to ensure the effect of the first embodiment, the lower limit of the conditional expression (3) is set to 10.30, and further 10.50, 10.80, 11.00, 11.30, 11.50, 11 It is more preferably .80. In order to ensure the effect of the first embodiment, it is more preferable that the upper limit of the conditional expression (3) is 20.00, and more preferably 18.00, 16.00, 14.00.

The zoom lens ZL according to the first embodiment preferably satisfies the following conditional expression (4).
33.00 <ft / (-f2) <60.00 ... (4)
However, ft: the focal length of the entire zoom lens system in the telephoto end state.

Conditional expression (4) defines an appropriate range of the ratio between the focal length of the entire zoom lens system in the telephoto end state and the focal length of the second lens group G2. Both when the upper limit value of the conditional expression (4) is exceeded and when it is lower than the lower limit value, various aberrations such as chromatic aberration of magnification, coma, and astigmatism worsen, which is not preferable.

In order to ensure the effect of the first embodiment, the lower limit of the conditional expression (4) is set to 34.00, and further set to 35.00, 36.00, 37.00, 38.00, 39.00. Is more preferable. In order to ensure the effect of the first embodiment, the upper limit of the conditional expression (4) is 59.00, and further, 58.00, 57.00, 56.00, 53.00, 51.00. Is more preferable.

The zoom lens ZL according to the first embodiment preferably satisfies the following conditional expression (5).
65.00 <(β2t ・ β3t) / (β2w ・ β3w) <120.00 ・ ・ ・ (5)
However, β2t: Magnification of the second lens group G2 in the telephoto end state β3t: Magnification of the third lens group G3 in the telephoto end state β2w: Magnification of the second lens group G2 in the wide-angle end state β3w: Third lens in the wide-angle end state Magnification of group G3

The conditional expression (5) defines an appropriate range of the product of the magnification ratios of the second lens group G2 and the third lens group G3. Both when the upper limit value of the conditional expression (5) is exceeded and when it is lower than the lower limit value, various aberrations such as spherical aberration and coma are deteriorated, which is not preferable.

In order to ensure the effect of the first embodiment, the lower limit of the conditional expression (5) is set to 66.00, and further set to 67.00, 68.00, 69.00, 70.00, 75.00. Is more preferable. In order to ensure the effect of the first embodiment, the upper limit of the conditional expression (5) is set to 118.00, further set to 116.00, 114.00, 112.00, 110.00, 107.00. Is more preferable.

The zoom lens ZL according to the first embodiment preferably satisfies the following conditional expression (6).
18.00 <ft / f3 <33.00 ... (6)
However, f3: focal length of the third lens group G3

Conditional expression (6) defines an appropriate range of the ratio between the focal length of the entire zoom lens system in the telephoto end state and the focal length of the third lens group G3. Both when the upper limit value of the conditional expression (6) is exceeded and when it is lower than the lower limit value, various aberrations such as coma are deteriorated, which is not preferable.

In order to ensure the effect of the first embodiment, the lower limit of the conditional expression (6) is set to 18.30, and further 18.60, 18.90, 19.20, 19.50, 19.80, 20. It is more preferably set to .00. In order to ensure the effect of the first embodiment, the upper limit of the conditional expression (6) is set to 32.00, and further set to 31.00, 30.00, 29.00, 28.00, 27.00. Is more preferable.

The zoom lens ZL according to the first embodiment preferably satisfies the following conditional expression (7).
10.00 <ft / X2 <20.00 ... (7)
However, X2: The distance at which the second lens group G2 moves in the image plane direction with respect to the imaging position when scaling from the wide-angle end state to the telephoto end state.

Conditional expression (7) defines an appropriate range of the ratio between the distance that the second lens group G2 moves when scaling from the wide-angle end state to the telephoto end state and the focal length of the entire zoom lens system in the telephoto end state. ing. Both when the upper limit value of the conditional expression (7) is exceeded and when it is lower than the lower limit value, various aberrations such as coma are deteriorated, which is not preferable.

In order to ensure the effect of the first embodiment, it is more preferable that the lower limit of the conditional expression (7) is 10.20, further 10.40, 10.60, 10.80, and 11.00. .. In order to ensure the effect of the first embodiment, it is more preferable that the upper limit of the conditional expression (7) is 19.00, and further preferably 18.00, 17.00, 16.50.

The zoom lens ZL according to the first embodiment preferably has an aperture diaphragm S between the second lens group G2 and the fourth lens group G4. With this configuration, it is possible to satisfactorily correct various aberrations such as spherical aberration, coma, and curvature of field with a small size.

The zoom lens ZL according to the first embodiment preferably has an aperture diaphragm S between the second lens group G2 and the third lens group G3. With this configuration, it is possible to satisfactorily correct various aberrations such as spherical aberration, coma, and curvature of field with a small size.

The zoom lens ZL according to the first embodiment preferably satisfies the following conditional expression (8).
0.10 ° <ωt <4.00 ° ・ ・ ・ (8)
However, ωt: half angle of view at the telephoto end

The conditional expression (8) is a conditional expression that defines the optimum value of the angle of view in the telephoto end state. By satisfying this conditional equation (8), various aberrations such as coma, distortion, and curvature of field can be satisfactorily corrected.

In order to ensure the effect of the first embodiment, it is more preferable that the lower limit of the conditional expression (8) is 0.20 °, further preferably 0.25 °, 0.30 °, 0.33 °. .. In order to ensure the effect of the first embodiment, it is more preferable that the upper limit of the conditional expression (8) is 3.00 °, and further preferably 2.00 ° and 1.00 °.

The zoom lens ZL according to the first embodiment preferably satisfies the following conditional expression (9).
25.00 ° <ωw <80.00 ° ・ ・ ・ (9)
However, ωw: half angle of view at the wide-angle end state

The conditional expression (9) is a conditional expression that defines the optimum value of the angle of view in the wide-angle end state. By satisfying this conditional equation (9), various aberrations such as coma, distortion, and curvature of field can be satisfactorily corrected.

In order to ensure the effect of the first embodiment, it is more preferable that the lower limit of the conditional expression (9) is 30.00 °, further 35.00 ° and 40.00 °. In order to ensure the effect of the first embodiment, it is more preferable that the upper limit of the conditional expression (9) is 70.00 °, further 60.00 ° and 50.00 °.

Subsequently, with reference to FIG. 20, the manufacturing method of the zoom lens ZL according to the first embodiment will be outlined. First, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, a third lens group G3 having a positive refractive power, and a negative refractive power. The fourth lens group G4 having a positive refractive power and the fifth lens group G5 having a positive refractive power are arranged side by side in the lens barrel (step ST1). Next, it is configured to change the distance between adjacent lens groups at the time of magnification change (step ST2). Further, it is configured so as to satisfy the above conditional expression (1) (step ST3).

According to the method for manufacturing a zoom lens ZL according to the first embodiment, it is possible to manufacture a zoom lens having good optical performance while having a high magnification.

Hereinafter, the second embodiment will be described. As shown in FIG. 1, the zoom lens ZL (1) as an example of the zoom lens ZL according to the second embodiment includes a first lens group G1 having a positive refractive power arranged in order from the object side and a negative lens group G1. A second lens group G2 having a refractive power, a third lens group G3 having a positive refractive power, a fourth lens group G4 having a negative refractive power, and a fifth lens group G5 having a positive refractive power. At the time of magnification change, the distance between adjacent lens groups changes.

The zoom lens ZL according to the second embodiment is shown in the zoom lens ZL (2) shown in FIG. 4, the zoom lens ZL (3) shown in FIG. 7, the zoom lens ZL (4) shown in FIG. 10, and FIG. The zoom lens ZL (5) or the zoom lens ZL (6) shown in FIG. 16 may be used.

The zoom lens ZL according to the second embodiment satisfies the following conditional expression (2) under the above configuration.

33.00 <f1 / fw <50.00 ... (2)
However, fw: the focal length of the entire zoom lens system in the wide-angle end state f1: the focal length of the first lens group G1.

By configuring the zoom lens ZL according to the second embodiment as described above, high magnification can be achieved. According to the camera 1 provided with the zoom lens ZL according to the second embodiment as the photographing lens 2, it is possible to realize a camera having good optical performance while having a high magnification.

The conditional expression (2) defines an appropriate range of the ratio between the focal length of the first lens group G1 and the focal length of the entire zoom lens system in the wide-angle end state. Both when the upper limit value of the conditional expression (2) is exceeded and when it is lower than the lower limit value, various aberrations such as distortion, astigmatism, and coma are deteriorated, which is not preferable.

In order to ensure the effect of the second embodiment, the lower limit of the conditional expression (2) is set to 33.50, and further set to 34.00, 34.50, 35.00, 35.50, 36.00. Is more preferable. In order to ensure the effect of the second embodiment, the upper limit of the conditional expression (2) is set to 49.00, further set to 48.00, 47.00, 46.00, 45.00, 43.00. Is more preferable.

The zoom lens ZL according to the second embodiment preferably satisfies the following conditional expression (1).
13.00 <f1 / (-f2) ... (1)
However, f2: focal length of the second lens group G2

The conditional expression (1) is a conditional expression for reducing spherical aberration, astigmatism, and chromatic aberration. When the refractive power of the first lens group G1 becomes too large and falls below the lower limit of the conditional equation (1), it is advantageous for miniaturization, but it becomes difficult to correct spherical aberration and chromatic aberration of magnification in the telephoto end state. Become. Further, when the refractive power of the second lens group G2 becomes too small and falls below the lower limit of the conditional expression (1), the overall length is increased in order to secure a high magnification ratio. Here, in order to maintain the miniaturization of the optical system, the refractive power of the first lens group G1 must be increased, and the spherical aberration in the telephoto end state is deteriorated.

In order to ensure the effect of the second embodiment, it is more preferable that the lower limit of the conditional expression (1) is 13.30, and more preferably 13.60, 13.90, 14.20. In order to ensure the effect of the second embodiment, the upper limit of the conditional expression (1) is set to 25.00, and further set to 23.00, 20.00, 19.00, 18.00, 17.00. Is more preferable. By satisfying the conditional expression (2) provided with such an upper limit value, spherical aberration, astigmatism and chromatic aberration become smaller, which is preferable.

In the zoom lens ZL according to the second embodiment, it is preferable that the first lens group G1 moves toward the object when at least a part of the magnification is changed from the wide-angle end state to the telephoto end state. With this configuration, it is possible to achieve a high magnification with a small size.

In the zoom lens ZL according to the second embodiment, the distance between the first lens group G1 and the second lens group G2 is expanded when at least a part of the magnification is changed from the wide-angle end state to the telescopic end state, and the second lens group G2 It is preferable that the distance between the third lens group G3 and the third lens group G3 is reduced and the distance between the third lens group G3 and the fourth lens group G4 is increased. With this configuration, it is possible to achieve a high magnification with a small size.

In the zoom lens ZL according to the second embodiment, it is preferable that the first lens group G1, the second lens group G2, the third lens group G3, and the fourth lens group G4 move along the optical axis at the time of magnification change. With this configuration, it is possible to achieve a high magnification with a small size.

In the zoom lens ZL according to the second embodiment, it is preferable that the fifth lens group G5 moves along the optical axis at the time of scaling. With this configuration, it is possible to achieve a high magnification with a small size.

In the zoom lens ZL according to the second embodiment, it is preferable that at least one lens surface of the third lens group G3 has an aspherical surface. With this configuration, it is possible to satisfactorily correct various aberrations such as spherical aberration and coma aberration with a small size.

In the zoom lens ZL according to the second embodiment, it is preferable that the first lens group G1 is composed of four lenses. With this configuration, it is possible to satisfactorily correct various aberrations such as spherical aberration and coma aberration with a small size.

The zoom lens ZL according to the second embodiment preferably has a fourth lens group G4 composed of two or less lenses. With this configuration, it is possible to satisfactorily correct various aberrations such as spherical aberration and coma aberration with a small size.

It is preferable that the zoom lens ZL according to the second embodiment is composed of two or less lenses in the fifth lens group G5. With this configuration, it is possible to satisfactorily correct various aberrations such as spherical aberration and coma aberration with a small size.

In the zoom lens ZL according to the second embodiment, it is preferable that at least one lens surface of the fifth lens group G5 has an aspherical surface. With this configuration, it is possible to satisfactorily correct various aberrations such as spherical aberration and coma aberration with a small size.

In the zoom lens ZL according to the second embodiment, it is preferable that the fourth lens group G4 moves along the optical axis at the time of focusing. With this configuration, fluctuations in various aberrations such as spherical aberration and coma during focusing can be reduced. At the time of focusing, at least a part of the fourth lens group G4 may move along the optical axis.

In the zoom lens ZL according to the second embodiment, it is preferable that the third lens group G3 has at least a part of a vibration-proof lens group that can be moved so as to have a displacement component in a direction perpendicular to the optical axis. With this configuration, it is possible to reduce fluctuations in various aberrations such as coma during image stabilization. The anti-vibration lens group may be the entire third lens group G3, any lens constituting the third lens group G3, or a combination thereof. For example, the positive lens on the most object side of the third lens group G3 or the junction lens on the most image side of the third lens group G3 may form the anti-vibration lens group.

The zoom lens ZL according to the second embodiment preferably satisfies the following conditional expression (3).
10.00 <Dt12 / (-f2) ... (3)
However, Dt12: the distance on the optical axis from the image side surface of the first lens group G1 to the object side surface of the second lens group G2 in the telephoto end state.

The conditional expression (3) is a conditional expression for reducing spherical aberration, chromatic aberration of magnification, and axial chromatic aberration to ensure good optical performance. When the value is lower than the lower limit of the conditional expression (3), the distance between the first lens group G1 and the second lens group G2 in the telephoto end state becomes significantly smaller, so that the refraction of the first lens group G1 and the second lens group G2 The power becomes too great. When the refractive power of the first lens group G1 becomes large, it becomes difficult to correct spherical aberration and chromatic aberration of magnification, especially in the telephoto end state. When the refractive power of the second lens group G2 becomes large, it becomes difficult to correct the axial chromatic aberration.

In order to ensure the effect of the second embodiment, the lower limit of the conditional expression (3) is set to 10.30, and further 10.50, 10.80, 11.00, 11.30, 11.50, 11 It is more preferably .80. In order to ensure the effect of the second embodiment, it is more preferable that the upper limit of the conditional expression (3) is 20.00, and more preferably 18.00, 16.00, 14.00.

The zoom lens ZL according to the second embodiment preferably satisfies the following conditional expression (4).
33.00 <ft / (-f2) <60.00 ... (4)
However, ft: the focal length of the entire zoom lens system in the telephoto end state.

Conditional expression (4) defines an appropriate range of the ratio between the focal length of the entire zoom lens system in the telephoto end state and the focal length of the second lens group G2. Both when the upper limit value of the conditional expression (4) is exceeded and when it is lower than the lower limit value, various aberrations such as chromatic aberration of magnification, coma, and astigmatism worsen, which is not preferable.

In order to ensure the effect of the second embodiment, the lower limit of the conditional expression (4) is set to 34.00, and further set to 35.00, 36.00, 37.00, 38.00, 39.00. Is more preferable. In order to ensure the effect of the second embodiment, the upper limit of the conditional expression (4) is 59.00, and further, 58.00, 57.00, 56.00, 53.00, 51.00. Is more preferable.

The zoom lens ZL according to the second embodiment preferably satisfies the following conditional expression (5).
65.00 <(β2t ・ β3t) / (β2w ・ β3w) <120.00 ・ ・ ・ (5)
However, β2t: Magnification of the second lens group G2 in the telephoto end state β3t: Magnification of the third lens group G3 in the telephoto end state β2w: Magnification of the second lens group G2 in the wide-angle end state β3w: Third lens in the wide-angle end state Magnification of group G3

The conditional expression (5) defines an appropriate range of the product of the magnification ratios of the second lens group G2 and the third lens group G3. Both when the upper limit value of the conditional expression (5) is exceeded and when it is lower than the lower limit value, various aberrations such as spherical aberration and coma are deteriorated, which is not preferable.

In order to ensure the effect of the second embodiment, the lower limit of the conditional expression (5) is set to 66.00, and further set to 67.00, 68.00, 69.00, 70.00, 75.00. Is more preferable. In order to ensure the effect of the second embodiment, the upper limit of the conditional expression (5) is set to 118.00, further set to 116.00, 114.00, 112.00, 110.00, 107.00. Is more preferable.

The zoom lens ZL according to the second embodiment preferably satisfies the following conditional expression (6).
18.00 <ft / f3 <33.00 ... (6)
However, f3: focal length of the third lens group G3

Conditional expression (6) defines an appropriate range of the ratio between the focal length of the entire zoom lens system in the telephoto end state and the focal length of the third lens group G3. Both when the upper limit value of the conditional expression (6) is exceeded and when it is lower than the lower limit value, various aberrations such as coma are deteriorated, which is not preferable.

In order to ensure the effect of the second embodiment, the lower limit of the conditional expression (6) is set to 18.30, and further 18.60, 18.90, 19.20, 19.50, 19.80, 20. It is more preferably set to .00. In order to ensure the effect of the second embodiment, the upper limit of the conditional expression (6) is set to 32.00, and further set to 31.00, 30.00, 29.00, 28.00, 27.00. Is more preferable.

The zoom lens ZL according to the second embodiment preferably satisfies the following conditional expression (7).
10.00 <ft / X2 <20.00 ... (7)
However, X2: The distance at which the second lens group G2 moves in the image plane direction with respect to the imaging position when scaling from the wide-angle end state to the telephoto end state.

Conditional expression (7) defines an appropriate range of the ratio between the distance that the second lens group G2 moves when scaling from the wide-angle end state to the telephoto end state and the focal length of the entire zoom lens system in the telephoto end state. ing. Both when the upper limit value of the conditional expression (7) is exceeded and when it is lower than the lower limit value, various aberrations such as coma are deteriorated, which is not preferable.

In order to ensure the effect of the second embodiment, it is more preferable that the lower limit of the conditional expression (7) is 10.20, further 10.40, 10.60, 10.80, and 11.00. .. In order to ensure the effect of the second embodiment, it is more preferable that the upper limit value of the conditional expression (7) is 19.00, and further preferably 18.00, 17.00, 16.50.

The zoom lens ZL according to the second embodiment preferably has an aperture diaphragm S between the second lens group G2 and the fourth lens group G4. With this configuration, it is possible to satisfactorily correct various aberrations such as spherical aberration, coma, and curvature of field with a small size.

The zoom lens ZL according to the second embodiment preferably has an aperture diaphragm S between the second lens group G2 and the third lens group G3. With this configuration, it is possible to satisfactorily correct various aberrations such as spherical aberration, coma, and curvature of field with a small size.

The zoom lens ZL according to the second embodiment preferably satisfies the following conditional expression (8).
0.10 ° <ωt <4.00 ° ・ ・ ・ (8)
However, ωt: half angle of view at the telephoto end

The conditional expression (8) is a conditional expression that defines the optimum value of the angle of view in the telephoto end state. By satisfying this conditional equation (8), various aberrations such as coma, distortion, and curvature of field can be satisfactorily corrected.

In order to ensure the effect of the second embodiment, it is more preferable that the lower limit of the conditional expression (8) is 0.20 °, further preferably 0.25 °, 0.30 °, 0.33 °. .. In order to ensure the effect of the second embodiment, it is more preferable that the upper limit of the conditional expression (8) is 3.00 °, and further preferably 2.00 ° and 1.00 °.

The zoom lens ZL according to the second embodiment preferably satisfies the following conditional expression (9).
25.00 ° <ωw <80.00 ° ・ ・ ・ (9)
However, ωw: half angle of view at the wide-angle end state

The conditional expression (9) is a conditional expression that defines the optimum value of the angle of view in the wide-angle end state. By satisfying this conditional equation (9), various aberrations such as coma, distortion, and curvature of field can be satisfactorily corrected.

In order to ensure the effect of the second embodiment, it is more preferable that the lower limit of the conditional expression (9) is 30.00 °, further 35.00 ° and 40.00 °. In order to ensure the effect of the second embodiment, it is more preferable that the upper limit of the conditional expression (9) is 70.00 °, further 60.00 ° and 50.00 °.

Subsequently, with reference to FIG. 20, the manufacturing method of the zoom lens ZL according to the second embodiment will be outlined. First, in order from the object side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, a third lens group G3 having a positive refractive power, and a negative refractive power. The fourth lens group G4 having a positive refractive power and the fifth lens group G5 having a positive refractive power are arranged side by side in the lens barrel (step ST1). Next, it is configured to change the distance between adjacent lens groups at the time of magnification change (step ST2). Further, it is configured so as to satisfy the above conditional expression (2) (step ST3).

According to the method for manufacturing the zoom lens ZL according to the second embodiment, it is possible to manufacture a zoom lens having good optical performance while having a high magnification.

Hereinafter, the zoom lens ZL according to the first and second embodiments will be described with reference to the drawings. 1, FIG. 4, FIG. 7, FIG. 10, FIG. 13, and FIG. 16 are cross-sectional views showing the configuration and the like of the zoom lenses ZL {ZL (1) to ZL (6)} according to the first to sixth embodiments. is there. The arrows shown at the bottom of these figures indicate the moving directions of the first to fifth lens groups G1 to G5 and the aperture diaphragm S when zooming (magnifying operation) from the wide-angle end state to the telephoto end state.

In the zoom lenses ZL (1) to (6) according to the first to sixth embodiments, the entire fourth lens group G4 constitutes a focusing lens group, and the entire fourth lens group G4 is in the image plane direction. By moving to, focusing from a long-distance object to a short-distance object is performed. In each figure, the moving direction when the focusing lens group focuses on a short-distance object from infinity is indicated by an arrow together with the symbol "∞". Further, in the zoom lenses ZL (1) to (6) according to the first to sixth embodiments, the third lens group G3 constitutes a vibration-proof lens group that can move in a direction perpendicular to the optical axis, and camera shake occurs. The displacement of the imaging position (image blurring on the image plane I) due to the above is corrected.

In these figures, each lens group is represented by a combination of reference numerals G and numbers, and each lens is represented by a combination of reference numerals L and numbers. In this case, in order to prevent the types and numbers of the symbols and numbers from becoming large and complicated, the lens group and the like are represented by independently using combinations of the symbols and numbers for each embodiment. Therefore, even if the same combination of reference numerals and numbers is used between the examples, it does not mean that they have the same configuration.

Tables 1 to 6 are shown below, which are tables showing each specification data in the first to sixth embodiments.

In the [Lens Specifications] table, the surface numbers indicate the order of the optical surfaces from the object side along the direction in which the light beam travels, and R is the radius of curvature of each optical surface (the surface whose center of curvature is located on the image side). (Positive value), D is the distance on the optical axis from each optical surface to the next optical surface, nd is the refractive index of the material of the optical member with respect to the d line (wavelength 587.6 nm), and νd is optical. The Abbe number based on the d-line of the material of the member is shown. The surface number indicates the order of the lens surfaces from the object side along the traveling direction of the light beam. “∞” of the radius of curvature indicates a plane or an aperture, and (aperture S) indicates an aperture stop S. The description of the refractive index nd of air = 1.00000 is omitted. When the lens surface is aspherical, the surface number is marked with * and the radius of curvature R indicates the paraxial radius of curvature.

The [Overall specifications] table shows the specifications of the entire zoom lens, where f is the focal length of the entire lens system, Fno is the F number, and ω is the half angle of view (maximum angle of view, unit is "° (degrees)". ), Y indicates the image height. BF indicates the distance (back focus) from the final surface of the lens on the optical axis to the image plane I when focusing at infinity, and TL is the total length of the lens, from the frontmost surface of the lens to the final surface of the lens on the optical axis. The distance obtained by adding BF to the distance is shown. These values are shown for each of the wide-angle end state (Wide), the intermediate focal length (Middle), and the telephoto end state (Tele) in each variable magnification state.

In the table of [Aspherical surface data], the shape of the aspherical surface shown in [Lens specifications] is shown by the following equation (a). X (y) is the distance (zag amount) along the optical axis direction from the tangent plane at the aspherical apex to the position on the aspherical surface at the height y, and R is the radius of curvature of the reference sphere (near axis curvature radius) , Κ indicates the conical constant, and Ai indicates the i-th order aspherical coefficient. "E-n" indicates " ^{x10 -n".} For example, 1.234E-05 = 1.234 × 10 ^-5 . The second-order aspherical coefficient A2 is 0, and the description thereof is omitted.

X (y) = (y ² / R) / {1 + (1-κ × y ² / R ² ) ^1/2 } + A4 × y ⁴ + A6 × y ⁶ + A8 × y ⁸ + A10 × y ¹⁰ ... (a) )

The table of [variable spacing data] shows the plane spacing Di to the next plane at the plane number i in which the plane spacing is "variable" in the table showing [lens specifications]. For example, in the first embodiment, the surface spacings D7, D16, D24, D27, D30 at the surface numbers 7, 16, 24, 27, 30 are shown. f indicates the focal length of the entire zoom lens system.

In the table of [lens group data], the surface number of the group initial surface (the surface closest to the object) in the first to fifth lens groups G1 to G5 and the focal length of each group are shown.

The table of [Conditional expression corresponding values] shows the values corresponding to the above conditional expressions (1) to (9).

Hereinafter, in all the specification values, "mm" is generally used for the focal length f, the radius of curvature R, the surface spacing D, other lengths, etc., unless otherwise specified, but the optical system is expanded proportionally. Alternatively, it is not limited to this because the same optical performance can be obtained even if the proportional reduction is performed.

The above is a description of matters common to all the examples, and the duplicated description in each of the following examples will be omitted.

(First Example)
The first embodiment will be described with reference to FIGS. 1 to 3 and Table 1. FIG. 1 is a diagram showing a lens configuration of the zoom lens ZL (1) according to the first embodiment. The zoom lens ZL (1) has a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a positive refractive power arranged in order from the object side along the optical axis. It is composed of a third lens group G3 having a force, a fourth lens group G4 having a negative refractive power, and a fifth lens group G5 having a positive refractive power. The symbol (+) or (-) attached to each lens group symbol indicates the refractive power of each lens group. Filters FL1 and FL2 are provided near the image plane I on the image side of the fifth lens group G5. The filters FL1 and FL2 are composed of a low-pass filter, an infrared cut filter, and the like. The aperture diaphragm S is arranged on the object side of the third lens group G3. The aperture diaphragm S is configured independently of the third lens group G3, but moves in the optical axis direction together with the third lens group G3.

The first lens group G1 includes a junction lens of a negative meniscus lens L11 having a convex surface (first surface) facing the object side and a biconvex positive lens L12 arranged in order from the object side along the optical axis, and the object side. It is composed of a positive meniscus lens L13 having a convex surface facing the object and a positive meniscus lens L14 having a convex surface facing the object side.

The second lens group G2 includes a negative meniscus lens L21 having a convex surface facing the object side, a biconcave negative lens L22, and a biconvex positive lens L23 arranged in order from the object side along the optical axis. It is composed of a biconcave negative lens L24 and a junction lens of a positive meniscus lens L25 with a convex surface facing the object side.

The third lens group G3 includes a biconvex positive lens L31 arranged in order from the object side along the optical axis, a negative meniscus lens L32 having a convex surface facing the object side, and a negative meniscus lens L32 having a convex surface facing the object side. It is composed of a lens L33 and a junction lens of a biconvex positive lens L34. Both sides of the positive lens L31 are aspherical.

The fourth lens group G4 is composed of a junction lens of a biconvex positive lens L41 and a biconcave negative lens L42.

The fifth lens group G5 is composed of a biconvex positive lens L51 and a junction lens of a negative meniscus lens L52 with a concave surface facing the object side. The surface of the positive lens L51 on the object side is an aspherical surface.

In the zoom lens ZL (1), the first to fifth lens groups G1 to G5 move in the axial direction as shown by arrows in FIG. 1 when the magnification is changed from the wide-angle end state to the telephoto state. As shown in FIG. 2, the positions of the respective lens groups in the wide-angle end state (W), the intermediate focal distance state (M), and the telescopic end state (T) of the zoom lens ZL (1) are shown in the zoom lens ZL (1). When scaling from the wide-angle end state to the telescopic state, the first lens group G1 moves to the object side and the second lens group G2 moves to the image plane side, and the distance between the first lens group G1 and the second lens group G2. Expands, the third lens group G3 moves toward the object side, the distance between the second lens group G2 and the third lens group G3 decreases, and the fourth lens group G4 moves toward the object side, and the third lens group G3 The distance between the fourth lens group G4 and the fourth lens group G4 is increased, the fifth lens group G5 is moved toward the image plane side, and the distance between the fourth lens group G4 and the fifth lens group G5 is increased. In this way, in the zoom lens ZL (1), all of the first to fifth lens groups G1 to G5 move on the optical axis when the magnification is changed from the wide-angle end state to the telephoto state. Therefore, these surface spacings D7, D16, D24, D27, and D30 are variable, and their values are shown in the [Variable spacing data] table.

Table 1 below lists the values of the specifications of the optical system according to the first embodiment.

(Table 1)
[Lens data]
Surface number RD nd νd
1 1125.7508 2.900 1.80400 46.60
2 116.6970 7.800 1.43700 95.00
3 -403.2629 0.100
4 120.4777 6.300 1.49782 82.57
5 5896.3575 0.100
6 131.5232 4.700 1.49782 82.57
7 706.2992 D7 (variable)
8 101.6165 1.300 1.83481 42.72
9 14.7585 7.000
10 -37.1514 1.200 1.83481 42.72
11 67.0205 0.100
12 28.0710 3.800 1.80518 25.45
13 -55.3977 1.600
14 -23.0138 1.000 1.71300 53.96
15 34.9690 1.800 1.92286 20.88
16 101.4240 D16 (variable)
17 ∞ 1.706 (Aperture S)
18 * 13.0051 4.100 1.49710 81.49
19 * -82.2128 2.800
20 26.3046 1.200 1.91082 35.25
21 11.9450 2.000
22 14.9394 1.200 1.77250 49.62
23 11.8012 3.600 1.49782 82.57
24-37.9553 D24 (variable)
25 99.5442 1.200 1.53172 48.78
26 -33.2270 0.700 1.49700 81.61
27 16.8349 D27 (variable)
28 * 26.3305 2.000 1.58913 61.15
29 -25.7210 0.600 1.75520 27.57
30 -63.6099 D30 (variable)
31 ∞ 0.400 1.51680 63.88
32 ∞ 0.700
33 ∞ 0.500 1.51680 63.88
34 ∞ BF

[Overall specifications]
Zoom ratio 118.06
Wide Middle Tele
f 4.429 48.774 522.925
Fno 2.823 4.541 8.320
ω 43.328 4.633 0.436
Y 3.35 4.05 4.05
BF 0.539 0.535 0.545
TL 167.110 220.006 264.348

[Aspherical data]
Surface number κ A4 A6 A8 A10
18 1.0000 -3.34121E-05 -7.80290E-08 0.00000E + 00 0.00000E + 00
19 1.0000 2.89440E-05 -5.47491E-09 7.18776E-10 0.00000E + 00
28 1.0000 -3.42328E-05 0.00000E + 00 0.00000E + 00 0.00000E + 00

[Variable interval data]
Variable Interval Wide Middle Tele
D7 0.750 96.945 143.215
D16 81.280 19.078 1.024
D24 2.275 19.965 22.135
D27 14.588 17.640 34.146
D30 5.272 3.437 0.876

[Zoom lens group data]
Group number Group first surface Group focal length
G1 1 170.596
G2 8 -11.460
G3 17 23.195
G4 25 -43.614
G5 28 36.268

[Conditional expression corresponding value]
Conditional expression (1) f1 / (-f2) = 14.886
Conditional expression (2) f1 / fw = 38.515
Conditional expression (3) Dt12 / (-f2) = 12.431
Conditional expression (4) ft / (-f2) = 45.63
Conditional expression (5) (β2t ・ β3t) / (β2w ・ β3w) = 85.70
Conditional expression (6) ft / f3 = 22.544
Conditional expression (7) ft / X2 = 11.562
Conditional expression (8) ωt = 0.436 °
Conditional expression (9) ωw = 43.328 °

As shown in the table of the above [conditional expression corresponding values], the zoom lens ZL (1) according to the first embodiment shown in FIG. 1 satisfies all of the above conditional expressions (1) to (9).

3 (A), 3 (B), and 3 (C) show infinity focusing in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens ZL (1) according to the first embodiment, respectively. It is a diagram of various aberrations of time. As can be seen from the various aberration diagrams, the zoom lens ZL (1) according to the first embodiment satisfactorily corrects various aberrations from the wide-angle end state to the telephoto end state and has excellent imaging performance. Understand. Distortion can be corrected by image processing after imaging, and optical correction is not required.

In FIG. 3, FNO indicates an F number, and A indicates a half angle of view (unit: “°”) for each image height. d indicates the aberration at the d line (λ = 587.6 nm), and g indicates the aberration at the g line (λ = 435.8 nm). In the spherical aberration diagram, the astigmatism diagram, and the coma aberration diagram, the solid line indicates the aberration of the sagittal image plane, and the broken line indicates the aberration of the meridional image plane. This description is the same for all the aberration diagrams of the following examples, and the duplicated description below will be omitted.

(Second Example)
The second embodiment will be described with reference to FIGS. 4 to 6 and Table 2. FIG. 4 is a diagram showing a lens configuration of the zoom lens ZL (2) according to the second embodiment. The zoom lens ZL (2) has a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a positive refractive power arranged in order from the object side along the optical axis. It is composed of a third lens group G3 having a force, a fourth lens group G4 having a negative refractive power, and a fifth lens group G5 having a positive refractive power. Filters FL1 and FL2 are provided near the image plane I on the image side of the fifth lens group G5. The filters FL1 and FL2 are composed of a low-pass filter, an infrared cut filter, and the like. The aperture diaphragm S is arranged on the object side of the third lens group G3. The aperture diaphragm S is configured independently of the third lens group G3, but moves in the optical axis direction together with the third lens group G3.

The first lens group G1 includes a junction lens of a negative meniscus lens L11 having a convex surface (first surface) facing the object side and a biconvex positive lens L12 arranged in order from the object side along the optical axis, and the object side. It is composed of a positive meniscus lens L13 having a convex surface facing the object and a positive meniscus lens L14 having a convex surface facing the object side.

The second lens group G2 includes a negative meniscus lens L21 having a convex surface facing the object side, a biconcave negative lens L22, and a biconvex positive lens L23 arranged in order from the object side along the optical axis. It is composed of a biconcave negative lens L24 and a biconvex positive lens L25.

The third lens group G3 includes a biconvex positive lens L31 arranged in order from the object side along the optical axis, a negative meniscus lens L32 having a convex surface facing the object side, and a negative meniscus lens L32 having a convex surface facing the object side. It is composed of a lens L33 and a junction lens of a biconvex positive lens L34. Both sides of the positive lens L31 are aspherical.

The fourth lens group G4 is composed of a junction lens of a positive meniscus lens L41 having a concave surface facing the object side and a negative lens L42 having a biconcave shape.

The fifth lens group G5 is composed of a junction lens of a negative meniscus lens L51 having a convex surface facing the object side and a biconvex positive lens L52. The surface of the positive lens L52 on the image plane side is an aspherical surface.

In the zoom lens ZL (2), the first to fifth lens groups G1 to G5 move in the axial direction as shown by arrows in FIG. 4 when the magnification is changed from the wide-angle end state to the telephoto state. As shown in FIG. 5, the positions of the respective lens groups in the wide-angle end state (W), the intermediate focal distance state (M), and the telescopic end state (T) of the zoom lens ZL (2) are shown in the zoom lens ZL (2). When scaling from the wide-angle end state to the telescopic state, the first lens group G1 moves to the object side and the second lens group G2 moves to the image plane side, and the distance between the first lens group G1 and the second lens group G2. Expands, the third lens group G3 moves toward the object side, the distance between the second lens group G2 and the third lens group G3 decreases, and the fourth lens group G4 moves toward the object side, and the third lens group G3 The distance between the fourth lens group G4 and the fourth lens group G4 is increased, the fifth lens group G5 is moved toward the image plane side, and the distance between the fourth lens group G4 and the fifth lens group G5 is increased. In this way, in the zoom lens ZL (2), all of the first to fifth lens groups G1 to G5 move on the optical axis when the magnification is changed from the wide-angle end state to the telephoto state. Therefore, these surface spacings D7, D16, D24, D27, and D30 are variable, and their values are shown in the [Variable spacing data] table.

Table 2 below lists the values of the specifications of the optical system according to the second embodiment.

(Table 2)
[Lens data]
Surface number RD nd νd
1 762.6435 2.300 1.80400 46.60
2 110.9325 7.800 1.43700 95.00
3 -702.7734 0.100
4 125.2419 6.300 1.49782 82.57
5 8413.3556 0.100
6 123.5962 5.400 1.49782 82.57
7 901.6298 D7 (variable)
8 101.5677 1.000 1.83481 42.73
9 14.2925 6.200
10 -54.9983 1.000 1.83481 42.73
11 35.1945 0.100
12 24.4888 3.100 1.80518 25.45
13 -94.2125 1.500
14 -20.6130 1.000 1.69680 55.52
15 48.3780 2.000 1.92286 20.88
16 -1754.4585 D16 (variable)
17 ∞ 0.750 (Aperture S)
18 * 12.7263 3.400 1.49710 81.49
19 * -56.2349 2.300
20 24.3889 1.000 1.91082 35.25
21 13.2913 1.850
22 17.3602 0.800 1.79500 45.31
23 10.7471 3.600 1.49700 81.61
24 -42.7734 D24 (variable)
25 -300.0000 1.900 1.53172 48.78
26 -15.0512 0.800 1.49700 81.61
27 15.6517 D27 (variable)
28 19.1974 0.800 1.75520 27.57
29 11.3922 2.700 1.58913 61.15
30 * -66.5570 D30 (variable)
31 ∞ 0.210 1.51680 63.88
32 ∞ 0.850
33 ∞ 0.500 1.51680 63.88
34 ∞ BF

[Overall specifications]
Zoom ratio 117.69
Wide Middle Tele
f 4.430 49.497 521.400
Fno 2.871 4.761 8.049
ω 43.237 4.555 0.437
Y 3.35 4.05 4.05
BF 0.397 0.441 0.400
TL 163.431 219.555 259.842

[Aspherical data]
Surface number κ A4 A6 A8 A10
18 0.1222 8.96340E-06 4.55104E-08 0.00000E + 00 0.00000E + 00
19 -19.3455 1.37509E-05 -1.49016E-08 0.00000E + 00 0.00000E + 00
30 1.0000 5.96451E-05 0.00000E + 00 0.00000E + 00 0.00000E + 00

[Variable interval data]
Variable Interval Wide Middle Tele
D7 0.744 99.860 143.560
D16 81.494 21.450 1.698
D24 3.056 17.514 27.871
D27 13.217 17.943 26.436
D30 5.161 2.987 0.518

[Zoom lens group data]
Group number Group first surface Group focal length
G1 1 171.549
G2 8 -11.391
G3 17 21.999
G4 25 -31.974
G5 28 29.995

[Conditional expression corresponding value]
Conditional expression (1) f1 / (-f2) = 15.060
Conditional expression (2) f1 / fw = 38.722
Conditional expression (3) Dt12 / (-f2) = 12.537
Conditional expression (4) ft / (-f2) = 45.77
Conditional expression (5) (β2t ・ β3t) / (β2w ・ β3w) = 88.02
Conditional expression (6) ft / f3 = 23.701
Conditional expression (7) ft / X2 = 11.236
Conditional expression (8) ωt = 0.437 °
Conditional expression (9) ωw = 43.23 °

As shown in the table of the above [conditional expression corresponding values], the zoom lens ZL (2) according to the second embodiment shown in FIG. 4 satisfies all of the above conditional expressions (1) to (9).

6 (A), 6 (B) and 6 (C) show infinity focusing in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens ZL (2) according to the second embodiment, respectively. It is a diagram of various aberrations of time. As can be seen from the various aberration diagrams, the zoom lens ZL (2) according to the second embodiment satisfactorily corrects various aberrations from the wide-angle end state to the telephoto end state and has excellent imaging performance. Understand.

(Third Example)
The third embodiment will be described with reference to FIGS. 7 to 9 and Table 3. FIG. 7 is a diagram showing a lens configuration of the zoom lens ZL (3) according to the third embodiment. The zoom lens ZL (3) has a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a positive refractive power arranged in order from the object side along the optical axis. It is composed of a third lens group G3 having a force, a fourth lens group G4 having a negative refractive power, and a fifth lens group G5 having a positive refractive power. Filters FL1 and FL2 are provided near the image plane I on the image side of the fifth lens group G5. The filters FL1 and FL2 are composed of a low-pass filter, an infrared cut filter, and the like. The aperture diaphragm S is arranged on the object side of the third lens group G3. The aperture diaphragm S is configured independently of the third lens group G3, but moves in the optical axis direction together with the third lens group G3.

The first lens group G1 includes a junction lens of a negative meniscus lens L11 having a convex surface (first surface) facing the object side and a biconvex positive lens L12 arranged in order from the object side along the optical axis, and the object side. It is composed of a positive meniscus lens L13 having a convex surface facing the object and a positive meniscus lens L14 having a convex surface facing the object side.

The second lens group G2 includes a negative meniscus lens L21 having a convex surface facing the object side, a biconcave negative lens L22, and a biconvex positive lens L23 arranged in order from the object side along the optical axis. It is composed of a biconcave negative lens L24.

The third lens group G3 includes a biconvex positive lens L31 arranged in order from the object side along the optical axis, a negative meniscus lens L32 having a convex surface facing the object side, and a negative meniscus lens L32 having a convex surface facing the object side. It is composed of a lens L33 and a junction lens of a biconvex positive lens L34. Both sides of the positive lens L31 are aspherical.

The fourth lens group G4 is composed of a junction lens of a positive meniscus lens L41 having a concave surface facing the object side and a negative lens L42 having a biconcave shape.

The fifth lens group G5 is composed of a junction lens of a negative meniscus lens L51 having a convex surface facing the object side and a biconvex positive lens L52. The surface of the positive lens L52 on the image plane side is an aspherical surface.

In the zoom lens ZL (3), the first to fifth lens groups G1 to G5 move in the axial direction as shown by arrows in FIG. 7 when the magnification is changed from the wide-angle end state to the telephoto state. As shown in FIG. 8, the positions of the respective lens groups in the wide-angle end state (W), the intermediate focal distance state (M), and the telescopic end state (T) of the zoom lens ZL (3) are shown in the zoom lens ZL (3). When scaling from the wide-angle end state to the telescopic state, the first lens group G1 moves to the object side and the second lens group G2 moves to the image plane side, and the distance between the first lens group G1 and the second lens group G2. Expands, the third lens group G3 moves toward the object side, the distance between the second lens group G2 and the third lens group G3 decreases, and the fourth lens group G4 moves toward the object side, and the third lens group G3 The distance between the fourth lens group G4 and the fourth lens group G4 is increased, the fifth lens group G5 is moved toward the image plane side, and the distance between the fourth lens group G4 and the fifth lens group G5 is increased. In this way, in the zoom lens ZL (3), all of the first to fifth lens groups G1 to G5 move on the optical axis when the magnification is changed from the wide-angle end state to the telephoto state. Therefore, these surface spacings D7, D15, D23, D26, and D29 are variable, and their values are shown in the [Variable spacing data] table.

Table 3 below lists the values of the specifications of the optical system according to the third embodiment.

(Table 3)
[Lens data]
Surface number RD nd νd
1 825.7960 2.300 1.79500 45.31
2 98.3187 6.400 1.49700 81.61
3 -700.6704 0.100
4 108.1709 5.300 1.49700 81.61
5 10000.0000 0.100
6 119.8529 4.200 1.49700 81.61
7 438.9962 D7 (variable)
8 120.0000 1.000 1.83481 42.73
9 12.6841 6.200
10 -27.7888 1.000 1.83481 42.73
11 68.4955 0.100
12 28.8219 3.200 1.92286 20.88
13 -60.7186 1.300
14 -22.0032 1.000 1.60300 65.44
15 432.8493 D15 (variable)
16 ∞ 0.750 (Aperture S)
17 * 12.5898 3.300 1.49710 81.49
18 * -55.5281 2.600
19 27.7261 1.000 1.91082 35.25
20 12.6137 1.650
21 16.3250 0.800 1.79500 45.31
22 12.0000 3.600 1.49700 81.61
23 -27.7139 D23 (variable)
24 -170.4623 1.900 1.53172 48.78
25 -12.9096 0.800 1.49700 81.61
26 16.8533 D26 (variable)
27 17.3060 0.800 1.84666 23.80
28 10.8145 2.500 1.58913 61.15
29 * -68.7620 D29 (variable)
30 ∞ 0.210 1.51680 63.88
31 ∞ 0.850
32 ∞ 0.500 1.51680 63.88
33 ∞ BF

[Overall specifications]
Zoom ratio 94.17
Wide Middle Tele
f 4.429 42.877 417.100
Fno 2.828 4.815 7.736
ω 43.275 5.234 0.544
Y 3.35 4.05 4.05
BF 0.397 0.408 0.400
TL 142.450 192.358 240.824

[Aspherical data]
Surface number κ A4 A6 A8 A10
17 0.1145 9.29785E-06 1.52178E-07 5.00000E-10 0.00000E + 00
18 -20.0000 2.20597E-05 8.60894E-08 0.00000E + 00 0.00000E + 00
29 1.0000 8.84720E-05 2.00000E-07 0.00000E + 00 0.00000E + 00

[Variable interval data]
Variable Interval Wide Middle Tele
D7 0.750 83.314 132.108
D15 68.015 16.620 1.700
D23 3.473 19.505 28.160
D26 11.594 16.242 24.205
D29 4.760 2.810 0.792

[Zoom lens group data]
Group number Group first surface Group focal length
G1 1 159.844
G2 8 -10.650
G3 16 20.841
G4 24 -33.300
G5 27 29.713

[Conditional expression corresponding value]
Conditional expression (1) f1 / (-f2) = 15.09
Conditional expression (2) f1 / fw = 36.090
Conditional expression (3) Dt12 / (-f2) = 12.334
Conditional expression (4) ft / (-f2) = 39.16
Conditional expression (5) (β2t ・ β3t) / (β2w ・ β3w) = 71.67
Conditional expression (6) ft / f3 = 20.104
Conditional expression (7) ft / X2 = 12.646
Conditional expression (8) ωt = 0.544 °
Conditional expression (9) ωw = 43.275 °

As shown in the table of the above [conditional expression corresponding values], the zoom lens ZL (3) according to the third embodiment shown in FIG. 7 satisfies all of the above conditional expressions (1) to (9).

9 (A), 9 (B), and 9 (C) show infinity focusing in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens ZL (3) according to the third embodiment, respectively. It is a diagram of various aberrations of time. As can be seen from the various aberration diagrams, the zoom lens ZL (3) according to the third embodiment satisfactorily corrects various aberrations from the wide-angle end state to the telephoto end state and has excellent imaging performance. Understand.

(Fourth Example)
A fourth embodiment will be described with reference to FIGS. 10 to 12 and Table 4. FIG. 10 is a diagram showing a lens configuration of the zoom lens ZL (4) according to the fourth embodiment. The zoom lens ZL (4) has a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a positive refractive power arranged in order from the object side along the optical axis. It is composed of a third lens group G3 having a force, a fourth lens group G4 having a negative refractive power, and a fifth lens group G5 having a positive refractive power. Filters FL1 and FL2 are provided near the image plane I on the image side of the fifth lens group G5. The filters FL1 and FL2 are composed of a low-pass filter, an infrared cut filter, and the like. The aperture diaphragm S is arranged on the object side of the third lens group G3. The aperture diaphragm S is configured independently of the third lens group G3, but moves in the optical axis direction together with the third lens group G3.

The first lens group G1 includes a junction lens of a negative meniscus lens L11 having a convex surface (first surface) facing the object side and a biconvex positive lens L12 arranged in order from the object side along the optical axis, and the object side. It is composed of a positive meniscus lens L13 having a convex surface facing the object and a positive meniscus lens L14 having a convex surface facing the object side.

The second lens group G2 includes a negative meniscus lens L21 having a convex surface facing the object side, a biconcave negative lens L22, and a biconvex positive lens L23 arranged in order from the object side along the optical axis. It is composed of a biconcave negative lens L24.

The third lens group G3 includes a biconvex positive lens L31 arranged in order from the object side along the optical axis, a negative meniscus lens L32 having a convex surface facing the object side, and a negative meniscus lens L32 having a convex surface facing the object side. It is composed of a lens L33 and a junction lens of a biconvex positive lens L34. Both sides of the positive lens L31 are aspherical.

The fourth lens group G4 is composed of a junction lens of a positive meniscus lens L41 having a concave surface facing the object side and a negative lens L42 having a biconcave shape.

The fifth lens group G5 is composed of a junction lens of a negative meniscus lens L51 having a convex surface facing the object side and a biconvex positive lens L52. The surface of the positive lens L52 on the image plane side is an aspherical surface.

In the zoom lens ZL (4), the first to fifth lens groups G1 to G5 move in the axial direction as shown by arrows in FIG. 10 when the magnification is changed from the wide-angle end state to the telephoto state. As shown in FIG. 11, the positions of the respective lens groups in the wide-angle end state (W), the intermediate focal distance state (M), and the telescopic end state (T) of the zoom lens ZL (4) are shown in the zoom lens ZL (4). When scaling from the wide-angle end state to the telescopic state, the first lens group G1 moves to the object side and the second lens group G2 moves to the image plane side, and the distance between the first lens group G1 and the second lens group G2. Expands, the third lens group G3 moves toward the object side, the distance between the second lens group G2 and the third lens group G3 decreases, and the fourth lens group G4 moves toward the object side, and the third lens group G3 The distance between the fourth lens group G4 and the fourth lens group G4 is increased, the fifth lens group G5 is moved toward the image plane side, and the distance between the fourth lens group G4 and the fifth lens group G5 is increased. In this way, in the zoom lens ZL (4), all of the first to fifth lens groups G1 to G5 move on the optical axis when the magnification is changed from the wide-angle end state to the telephoto state. Therefore, these surface spacings D7, D15, D23, D26, and D29 are variable, and their values are shown in the [Variable spacing data] table.

Table 4 below lists the values of the specifications of the optical system according to the fourth embodiment.

(Table 4)
[Lens data]
Surface number RD nd νd
1 670.6555 2.300 1.80400 46.60
2 104.1867 8.000 1.43700 95.00
3-583.2028 0.100
4 111.9338 6.500 1.49782 82.57
5 10000.0000 0.100
6 123.1395 5.000 1.49782 82.57
7 619.6537 D7 (variable)
8 100.0000 1.000 1.83481 42.73
9 12.5036 5.700
10 -25.7930 1.000 1.83481 42.73
11 140.7749 0.100
12 27.5761 3.200 1.92286 20.88
13 -54.7257 1.200
14 -22.7615 1.000 1.69680 55.52
15 121.4627 D15 (variable)
16 ∞ 0.750 (Aperture S)
17 * 12.6618 3.300 1.49710 81.49
18 * -47.4135 2.600
19 28.9431 1.000 1.91082 35.25
20 13.4878 1.650
21 16.9434 0.800 1.79500 45.31
22 11.1253 3.600 1.49700 81.61
23 -29.0967 D23 (variable)
24 -158.4748 1.900 1.53172 48.78
25 -12.6410 0.800 1.49700 81.61
26 16.6596 D26 (variable)
27 18.2350 0.800 1.84666 23.80
28 11.9152 2.500 1.58913 61.15
29 * -60.8073 D29 (variable)
30 ∞ 0.210 1.51680 63.88
31 ∞ 0.850
32 ∞ 0.500 1.51680 63.88
33 ∞ BF

[Overall specifications]
Zoom ratio 117.72
Wide Middle Tele
f 4.429 48.781 521.400
Fno 2.882 4.795 8.000
ω 43.280 4.604 0.435
Y 3.35 4.05 4.05
BF 0.399 0.411 0.399
TL 146.032 208.143 248.472

[Aspherical data]
Surface number κ A4 A6 A8 A10
17 0.5728 -2.22053E-05 3.07926E-08 0.00000E + 00 0.00000E + 00
18 -20.0000 1.33553E-05 6.68554E-08 -3.00000E-10 0.00000E + 00
29 1.0000 9.15167E-05 2.00000E-07 0.00000E + 00 0.00000E + 00

[Variable interval data]
Variable Interval Wide Middle Tele
D7 0.750 96.046 137.411
D15 68.897 18.921 1.700
D23 3.275 17.429 21.030
D26 11.494 16.462 30.683
D29 4.757 2.415 0.789

[Zoom lens group data]
Group number Group first surface Group focal length
G1 1 162.824
G2 8 -10.669
G3 16 20.757
G4 24 -32.719
G5 27 29.103

[Conditional expression corresponding value]
Conditional expression (1) f1 / (-f2) = 15.261
Conditional expression (2) f1 / fw = 36.763
Conditional expression (3) Dt12 / (-f2) = 12.809
Conditional expression (4) ft / (-f2) = 48.87
Conditional expression (5) (β2t ・ β3t) / (β2w ・ β3w) = 80.65
Conditional expression (6) ft / f3 = 25.120
Conditional expression (7) ft / X2 = 15.236
Conditional expression (8) ωt = 0.435 °
Conditional expression (9) ωw = 43.280 °

As shown in the table of the above [conditional expression corresponding values], the zoom lens ZL (4) according to the fourth embodiment shown in FIG. 10 satisfies all of the above conditional expressions (1) to (9).

12 (A), 12 (B), and 12 (C) show infinity focusing in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens ZL (4) according to the fourth embodiment, respectively. It is a diagram of various aberrations of time. As can be seen from the various aberration diagrams, the zoom lens ZL (4) according to the fourth embodiment satisfactorily corrects various aberrations from the wide-angle end state to the telephoto end state and has excellent imaging performance. Understand.

(Fifth Example)
A fifth embodiment will be described with reference to FIGS. 13 to 15 and Table 5. FIG. 13 is a diagram showing a lens configuration of the zoom lens ZL (5) according to the fifth embodiment. The zoom lens ZL (5) has a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a positive refractive power arranged in order from the object side along the optical axis. It is composed of a third lens group G3 having a force, a fourth lens group G4 having a negative refractive power, and a fifth lens group G5 having a positive refractive power. Filters FL1 and FL2 are provided near the image plane I on the image side of the fifth lens group G5. The filters FL1 and FL2 are composed of a low-pass filter, an infrared cut filter, and the like. The aperture diaphragm S is arranged on the object side of the third lens group G3. The aperture diaphragm S is configured independently of the third lens group G3, but moves in the optical axis direction together with the third lens group G3.

The first lens group G1 includes a junction lens of a negative meniscus lens L11 having a convex surface (first surface) facing the object side and a biconvex positive lens L12 arranged in order from the object side along the optical axis, and the object side. It is composed of a positive meniscus lens L13 having a convex surface facing the object and a positive meniscus lens L14 having a convex surface facing the object side.

The second lens group G2 includes a negative meniscus lens L21 having a convex surface facing the object side, a biconcave negative lens L22, and a biconvex positive lens L23 arranged in order from the object side along the optical axis. It is composed of a biconcave negative lens L24 and a junction lens of a positive meniscus lens L25 with a convex surface facing the object side.

The third lens group G3 includes a biconvex positive lens L31 arranged in order from the object side along the optical axis, a negative meniscus lens L32 having a convex surface facing the object side, and a negative meniscus lens L32 having a convex surface facing the object side. It is composed of a lens L33 and a junction lens of a biconvex positive lens L34. Both sides of the positive lens L31 are aspherical.

The fourth lens group G4 is composed of a junction lens of a positive meniscus lens L41 having a concave surface facing the object side and a negative lens L42 having a biconcave shape.

The fifth lens group G5 is composed of a junction lens of a negative meniscus lens L51 having a convex surface facing the object side and a biconvex positive lens L52. The surface of the positive lens L52 on the image plane side is an aspherical surface.

In the zoom lens ZL (5), the first to fifth lens groups G1 to G5 move in the axial direction as shown by arrows in FIG. 13 when the magnification is changed from the wide-angle end state to the telephoto state. As shown in FIG. 14, the positions of the respective lens groups in the wide-angle end state (W), the intermediate focal distance state (M), and the telescopic end state (T) of the zoom lens ZL (5) are shown in the zoom lens ZL (5). When scaling from the wide-angle end state to the telescopic state, the first lens group G1 moves to the object side and the second lens group G2 moves to the image plane side, and the distance between the first lens group G1 and the second lens group G2. Expands, the third lens group G3 moves toward the object side, the distance between the second lens group G2 and the third lens group G3 decreases, and the fourth lens group G4 moves toward the object side, and the third lens group G3 The distance between the fourth lens group G4 and the fourth lens group G4 is increased, the fifth lens group G5 is moved toward the image plane side, and the distance between the fourth lens group G4 and the fifth lens group G5 is increased. In this way, in the zoom lens ZL (5), all of the first to fifth lens groups G1 to G5 move on the optical axis when the magnification is changed from the wide-angle end state to the telephoto state. Therefore, these surface spacings D7, D16, D24, D27, and D30 are variable, and their values are shown in the [Variable spacing data] table.

Table 5 below lists the values of the specifications of the optical system according to the fifth embodiment.

(Table 5)
[Lens data]
Surface number RD nd νd
1 1755.7589 2.300 1.80400 46.60
2 128.4835 7.800 1.43700 95.00
3 -428.3359 0.100
4 137.3981 6.300 1.49782 82.57
5 8413.3556 0.100
6 129.8677 5.400 1.49782 82.57
7 810.4701 D7 (variable)
8 101.5677 1.000 1.83481 42.73
9 14.6453 6.200
10 -44.4343 1.000 1.83481 42.73
11 53.3734 0.100
12 29.0766 3.100 1.80518 25.45
13 -94.2125 1.500
14 -22.5108 1.000 1.69680 55.52
15 36.1975 2.000 1.92286 20.88
16 236.8685 D16 (variable)
17 ∞ 0.750 (Aperture S)
18 * 12.4947 3.400 1.49710 81.49
19 * -71.6510 2.300
20 22.6205 1.000 1.91082 35.25
21 11.9319 1.850
22 15.6310 0.800 1.79500 45.31
23 11.2452 3.600 1.49700 81.61
24 -43.9104 D24 (variable)
25 -300.0000 1.900 1.53172 48.78
26 -14.5782 0.800 1.49700 81.61
27 15.1307 D27 (variable)
28 17.9653 0.800 1.75520 27.57
29 10.8468 2.700 1.58913 61.15
30 * -64.5874 D30 (variable)
31 ∞ 0.210 1.51680 63.88
32 ∞ 0.850
33 ∞ 0.500 1.51680 63.88
34 ∞ BF

[Overall specifications]
Zoom ratio 124.51
Wide Middle Tele
f 4.429 48.530 551.400
Fno 2.837 4.688 7.982
ω 43.258 4.639 0.413
Y 3.35 4.05 4.05
BF 0.400 0.400 0.400
TL 162.470 226.839 270.824

[Aspherical data]
Surface number κ A4 A6 A8 A10
18 0.1863 1.31660E-05 2.77665E-08 0.00000E + 00 0.00000E + 00
19 -10.0000 2.59102E-05 -8.17364E-08 0.00000E + 00 0.00000E + 00
30 1.0000 5.47520E-05 0.00000E + 00 0.00000E + 00 0.00000E + 00

[Variable interval data]
Variable Interval Wide Middle Tele
D7 0.747 106.517 154.353
D16 79.997 21.447 1.695
D24 3.232 17.690 28.047
D27 13.230 17.955 26.448
D30 5.505 3.470 0.522

[Zoom lens group data]
Group number Group first surface Group focal length
G1 1 182.265
G2 8 -11.421
G3 17 22.002
G4 25 -30.965
G5 28 28.131

[Conditional expression corresponding value]
Conditional expression (1) f1 / (-f2) = 15.959
Conditional expression (2) f1 / fw = 41.156
Conditional expression (3) Dt12 / (-f2) = 11.966
Conditional expression (4) ft / (-f2) = 48.28
Conditional expression (5) (β2t ・ β3t) / (β2w ・ β3w) = 91.42
Conditional expression (6) ft / f3 = 25.062
Conditional expression (7) ft / X2 = 16.113
Conditional expression (8) ωt = 0.413 °
Conditional expression (9) ωw = 43.258 °

As shown in the table of the above [conditional expression corresponding values], the zoom lens ZL (5) according to the fifth embodiment shown in FIG. 13 satisfies all of the above conditional expressions (1) to (9).

15 (A), 15 (B) and 15 (C) show infinity focusing in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens ZL (5) according to the fifth embodiment, respectively. It is a diagram of various aberrations of time. As can be seen from the various aberration diagrams, the zoom lens ZL (5) according to the fifth embodiment satisfactorily corrects various aberrations from the wide-angle end state to the telephoto end state and has excellent imaging performance. Understand.

(6th Example)
The sixth embodiment will be described with reference to FIGS. 16 to 18 and Table 6. FIG. 16 is a diagram showing a lens configuration of the zoom lens ZL (6) according to the sixth embodiment. The zoom lens ZL (6) has a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, and a positive refractive power arranged in order from the object side along the optical axis. It is composed of a third lens group G3 having a force, a fourth lens group G4 having a negative refractive power, and a fifth lens group G5 having a positive refractive power. Filters FL1 and FL2 are provided near the image plane I on the image side of the fifth lens group G5. The filters FL1 and FL2 are composed of a low-pass filter, an infrared cut filter, and the like. The aperture diaphragm S is arranged on the object side of the third lens group G3. The aperture diaphragm S is configured independently of the third lens group G3, but moves in the optical axis direction together with the third lens group G3.

The first lens group G1 includes a junction lens of a negative meniscus lens L11 having a convex surface (first surface) facing the object side and a biconvex positive lens L12 arranged in order from the object side along the optical axis, and the object side. It is composed of a positive meniscus lens L13 having a convex surface facing the object and a positive meniscus lens L14 having a convex surface facing the object side.

The second lens group G2 includes a negative meniscus lens L21 having a convex surface facing the object side, a biconcave negative lens L22, and a biconvex positive lens L23 arranged in order from the object side along the optical axis. It is composed of a biconcave negative lens L24 and a junction lens of a positive meniscus lens L25 with a convex surface facing the object side.

The third lens group G3 includes a biconvex positive lens L31 arranged in order from the object side along the optical axis, a negative meniscus lens L32 having a convex surface facing the object side, and a negative meniscus lens L32 having a convex surface facing the object side. It is composed of a lens L33 and a junction lens of a biconvex positive lens L34. Both sides of the positive lens L31 are aspherical.

The fourth lens group G4 is composed of a junction lens of a positive meniscus lens L41 having a concave surface facing the object side and a negative lens L42 having a biconcave shape.

The fifth lens group G5 is composed of a junction lens of a negative meniscus lens L51 having a convex surface facing the object side and a biconvex positive lens L52. The surface of the positive lens L52 on the image plane side is an aspherical surface.

In the zoom lens ZL (6), the first to fifth lens groups G1 to G5 move in the axial direction as shown by arrows in FIG. 16 when the magnification is changed from the wide-angle end state to the telephoto state. As shown in FIG. 17, the positions of the respective lens groups in the wide-angle end state (W), the intermediate focal distance state (M), and the telescopic end state (T) of the zoom lens ZL (6) are shown in the zoom lens ZL (6). When scaling from the wide-angle end state to the telescopic state, the first lens group G1 moves to the object side and the second lens group G2 moves to the image plane side, and the distance between the first lens group G1 and the second lens group G2. Expands, the third lens group G3 moves toward the object side, the distance between the second lens group G2 and the third lens group G3 decreases, and the fourth lens group G4 moves toward the object side, and the third lens group G3 The distance between the fourth lens group G4 and the fourth lens group G4 is increased, the fifth lens group G5 is moved toward the image plane side, and the distance between the fourth lens group G4 and the fifth lens group G5 is increased. As described above, in the zoom lens ZL (6), all of the first to fifth lens groups G1 to G5 move on the optical axis when the magnification is changed from the wide-angle end state to the telephoto state. Therefore, these surface spacings D7, D16, D24, D27, and D30 are variable, and their values are shown in the [Variable spacing data] table.

Table 6 below lists the values of the specifications of the optical system according to the sixth embodiment.

(Table 6)
[Lens data]
Surface number RD nd νd
1 1983.8745 2.300 1.80400 46.60
2 140.4647 9.000 1.43700 95.00
3-418.7198 0.100
4 142.7297 6.300 1.49782 82.57
5 8413.3556 0.100
6 146.0517 5.400 1.49782 82.57
7 664.6345 D7 (variable)
8 101.5677 1.000 1.83481 42.73
9 13.6150 6.200
10 -44.4525 1.000 1.83481 42.73
11 50.6633 0.100
12 26.7472 3.100 1.80518 25.45
13 -94.2125 1.500
14 -22.6062 1.000 1.69680 55.52
15 40.1525 2.000 1.92286 20.88
16 380.6148 D16 (variable)
17 ∞ 0.750 (Aperture S)
18 * 12.5818 3.400 1.49710 81.49
19 * -62.1926 2.300
20 22.6772 1.000 1.91082 35.25
21 12.5702 1.850
22 15.7691 0.800 1.79500 45.31
23 10.1908 3.600 1.49700 81.61
24 -51.5490 D24 (variable)
25 -300.0000 1.900 1.53172 48.78
26 -14.6434 0.800 1.49700 81.61
27 15.3423 D27 (variable)
28 20.2943 0.800 1.75520 27.57
29 12.2152 2.700 1.58913 61.15
30 * -64.7065 D30 (variable)
31 ∞ 0.210 1.51680 63.88
32 ∞ 0.850
33 ∞ 0.500 1.51680 63.88
34 ∞ BF

[Overall specifications]
Zoom ratio 141.11
Wide Middle Tele
f 4.429 50.222 625.000
Fno 2.920 4.826 8.210
ω 43.299 4.482 0.365
Y 3.35 4.05 4.05
BF 0.400 0.400 0.400
TL 163.436 241.817 289.934

[Aspherical data]
Surface number κ A4 A6 A8 A10
18 0.1498 1.06103E-05 7.37832E-08 0.00000E + 00 0.00000E + 00
19 -10.0000 2.06381E-05 -1.53504E-08 0.00000E + 00 0.00000E + 00
30 1.0000 5.90152E-05 0.00000E + 00 0.00000E + 00 0.00000E + 00

[Variable interval data]
Variable Interval Wide Middle Tele
D7 0.750 120.124 172.500
D16 79.993 21.443 1.691
D24 3.006 17.464 27.821
D27 13.214 17.939 26.432
D30 5.513 3.886 0.530

[Zoom lens group data]
Group number Group first surface Group focal length
G1 1 199.598
G2 8 -11.253
G3 17 21.949
G4 25 -31.396
G5 28 30.837

[Conditional expression corresponding value]
Conditional expression (1) f1 / (-f2) = 17.737
Conditional expression (2) f1 / fw = 45.564
Conditional expression (3) Dt12 / (-f2) = 15.263
Conditional expression (4) ft / (-f2) = 55.54
Conditional expression (5) (β2t ・ β3t) / (β2w ・ β3w) = 105.53
Conditional expression (6) ft / f3 = 28.475
Conditional expression (7) ft / X2 = 13.812
Conditional expression (8) ωt = 0.365 °
Conditional expression (9) ωw = 43.299 °

As shown in the table of the above [conditional expression corresponding values], the zoom lens ZL (6) according to the sixth embodiment shown in FIG. 16 satisfies all of the above conditional expressions (1) to (9).

18 (A), 18 (B), and 18 (C) show infinity focusing in the wide-angle end state, the intermediate focal length state, and the telephoto end state of the zoom lens ZL (6) according to the sixth embodiment, respectively. It is a diagram of various aberrations of time. As can be seen from the various aberration diagrams, the zoom lens ZL (6) according to the sixth embodiment satisfactorily corrects various aberrations from the wide-angle end state to the telephoto end state and has excellent imaging performance. Understand.

Each of the above examples shows a specific example of the present invention, and the present invention is not limited thereto.

The following contents can be appropriately adopted as long as the optical performance of the zoom lenses of the first and second embodiments is not impaired.

As an example of the zoom lens of the first and second embodiments, the one having a five-group configuration is shown, but the present application is not limited to this, and a zoom lens having another group configuration (for example, six groups, etc.) may be configured. it can. Specifically, a lens or a lens group may be added to the most object side or the most image plane side of the zoom lenses of the first and second embodiments. The lens group refers to a portion having at least one lens separated by an air interval that changes at the time of magnification change.

A single lens group, a plurality of lens groups, or a partial lens group may be moved in the optical axis direction to form a focusing lens group for focusing from an infinity object to a short-distance object. The focusing lens group can also be applied to autofocus, and is also suitable for driving a motor for autofocus (using an ultrasonic motor or the like).

The lens group or partial lens group is moved so as to have a component in the direction perpendicular to the optical axis, or is rotationally moved (swinged) in the in-plane direction including the optical axis to correct image blur caused by camera shake. It may be used as an anti-vibration lens group.

The lens surface may be formed on a spherical surface or a flat surface, or may be formed on an aspherical surface. When the lens surface is spherical or flat, lens processing and assembly adjustment are facilitated, and deterioration of optical performance due to processing and assembly adjustment errors can be prevented, which is preferable. Further, even if the image plane is deviated, the depiction performance is less deteriorated, which is preferable.

When the lens surface is aspherical, the aspherical surface is an aspherical surface formed by grinding, a glass mold aspherical surface formed by forming glass into an aspherical shape, or a composite aspherical surface formed by forming resin on the glass surface into an aspherical shape. It doesn't matter which one. Further, the lens surface may be a diffraction surface, and the lens may be a refractive index distribution type lens (GRIN lens) or a plastic lens.

The aperture diaphragm is preferably arranged near or in the third lens group, but the role may be substituted by the frame of the lens without providing the member as the aperture diaphragm.

An antireflection film having a high transmittance in a wide wavelength range may be applied to each lens surface in order to reduce flare and ghost and achieve high contrast optical performance.

G1 1st lens group G2 2nd lens group G3 3rd lens group G4 4th lens group G5 5th lens group FL1, FL2 Filter I Image plane S Aperture aperture

Claims (26)

A first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a third lens group having a negative refractive power arranged in order from the object side. It has 4 lens groups and a 5th lens group having a positive refractive power, and the distance between adjacent lens groups changes at the time of magnification change.
A zoom lens that satisfies the following conditional expression.
13.00 <f1 / (-f2)
However, f1: the focal length of the first lens group f2: the focal length of the second lens group A first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a third lens group having a negative refractive power arranged in order from the object side. It has 4 lens groups and a 5th lens group having a positive refractive power, and the distance between adjacent lens groups changes at the time of magnification change.
A zoom lens that satisfies the following conditional expression.
33.00 <f1 / fw <50.00
However, fw: the focal length of the entire zoom lens system in the wide-angle end state f1: the focal length of the first lens group. The zoom lens according to claim 2, which satisfies the following conditional expression.
13.00 <f1 / (-f2)
However, f2: the focal length of the second lens group The zoom lens according to any one of claims 1 to 3, wherein the first lens group moves toward an object when the magnification is changed from a wide-angle state to a telephoto state. When the magnification is changed from the wide-angle state to the telephoto state, the distance between the first lens group and the second lens group is widened, the distance between the second lens group and the third lens group is reduced, and the third lens group is reduced. The zoom lens according to any one of claims 1 to 4, wherein the distance between the fourth lens group and the fourth lens group is increased. The zoom lens according to any one of claims 1 to 5, wherein the first lens group, the second lens group, the third lens group, and the fourth lens group move along the optical axis at the time of scaling. The zoom lens according to any one of claims 1 to 6, wherein the fifth lens group moves along the optical axis when the magnification is changed. The zoom lens according to any one of claims 1 to 7, wherein at least one lens surface of the third lens group has an aspherical surface. The zoom lens according to any one of claims 1 to 8, wherein the first lens group is composed of four lenses. The zoom lens according to any one of claims 1 to 9, wherein the fourth lens group is composed of two or less lenses. The zoom lens according to any one of claims 1 to 10, wherein the fifth lens group is composed of two or less lenses. The zoom lens according to any one of claims 1 to 11, wherein at least one lens surface of the fifth lens group has an aspherical surface. The zoom lens according to any one of claims 1 to 12, wherein at least a part of the fourth lens group moves along the optical axis when the lens is in focus. The zoom lens according to any one of claims 1 to 13, wherein the third lens group includes at least a part of an anti-vibration lens group that can be moved so as to have a displacement component in a direction perpendicular to the optical axis. The zoom lens according to any one of claims 1 to 14, which satisfies the following conditional expression.
10.00 <Dt12 / (-f2)
However, Dt12: the distance on the optical axis from the image side surface of the first lens group to the object side surface of the second lens group in the telephoto end state. The zoom lens according to any one of claims 1 to 15, which satisfies the following conditional expression.
33.00 <ft / (-f2) <60.00
However, ft: the focal length of the entire zoom lens system in the telephoto end state f2: the focal length of the second lens group. The zoom lens according to any one of claims 1 to 16, which satisfies the following conditional expression.
65.00 <(β2t ・ β3t) / (β2w ・ β3w) <120.00
However, β2t: the magnification of the second lens group in the telephoto end state β3t: the magnification of the third lens group in the telephoto end state β2w: the magnification of the second lens group in the wide-angle end state β3w: the third in the wide-angle end state. Lens group magnification The zoom lens according to any one of claims 1 to 17, which satisfies the following conditional expression.
18.00 <ft / f3 <33.00
However, ft: the focal length of the entire zoom lens system in the telephoto end state f3: the focal length of the third lens group. The zoom lens according to any one of claims 1 to 18, which satisfies the following conditional expression.
10.00 <ft / X2 <20.00
However, ft: the focal length of the entire zoom lens system in the telephoto end state X2: the distance at which the second lens group moves in the image plane direction with respect to the image formation position when scaling from the wide-angle end state to the telephoto end state. The zoom lens according to any one of claims 1 to 19, which has an aperture diaphragm between the second lens group and the fourth lens group. The zoom lens according to any one of claims 1 to 20, which has an aperture diaphragm between the second lens group and the third lens group. The zoom lens according to any one of claims 1 to 21, which satisfies the following conditional expression.
0.10 ° <ωt <4.00 °
However, ωt: half angle of view at the telephoto end The zoom lens according to any one of claims 1 to 22, which satisfies the following conditional expression.
25.00 ° <ωw <80.00 °
However, ωw: half angle of view at the wide-angle end state An optical device including the zoom lens according to any one of claims 1 to 23. A first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a third lens group having a negative refractive power arranged in order from the object side. It is a method for manufacturing a zoom lens having four lens groups and a fifth lens group having a positive refractive power, and changing the distance between adjacent lens groups at the time of magnification change.
A method for manufacturing a zoom lens in which the first to fifth lens groups are arranged in a lens barrel so as to satisfy the following conditional expression.
13.00 <f1 / (-f2)
However, f1: the focal length of the first lens group f2: the focal length of the second lens group A first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, and a third lens group having a negative refractive power arranged in order from the object side. It is a method for manufacturing a zoom lens having four lens groups and a fifth lens group having a positive refractive power, and changing the distance between adjacent lens groups at the time of magnification change.
A method for manufacturing a zoom lens in which the first to fifth lens groups are arranged in a lens barrel so as to satisfy the following conditional expression.
33.00 <f1 / fw <50.00
However, fw: the focal length of the entire zoom lens system in the wide-angle end state f1: the focal length of the first lens group.

Images