JPH08271790A - Zoom lens - Google Patents

Abstract

PURPOSE: To obtain a high-performance compact zoom lens constituted of 1st to 4th lens groups, each aberration of which is satisfactorily compensated by providing the 4th lens group with an aspherical surface which satisfies a specified condition and effectively using the aspherical surface. CONSTITUTION: The zoom lens is constituted of the positive 1st lens group, the negative 2nd lens group, the positive 3rd lens group, a diaphragm, the positive 4th lens group in this order from an object side, and at zooming from a wide angle side to a telephoto side, a distance between the 1st lens group and the 2nd lens group is increased, a distance between the 2nd lens group and the 3rd lens group is decreased, a distance between the 3rd lens group and the 4th lens group is decreased. Then, the 4th lens group is provided with at least one aspherical surface and which satisfies the following condituon; 0.1×10<-4> <|C4 |<0.1×10<-3> . Provided that (x) denotes the coordinate in an optical axis direction from the area of the aspherical surface, (y) denotes the coordinate in the normal direction to the (x) axis, R denotes the paraxial radius of curvature, each of (a2 ), (a4 ) and (a6 ) denotes an aspherical coefficient and (c4 ) denotes the (a4 ) of the aspherical coefficient in the case the expression of the aspherical surface is x=cy<2> (1+1-C<2> y<2> )<1/2> )<-1> +a2 Y<2> +a4 Y<4> +a6 Y<6> +..., c=1/R.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a zoom lens, and more particularly to a compact zoom lens including a wide angle of view of 63 ° and composed of three or more lens groups.

[0002]

2. Description of the Related Art Conventionally, as this type of lens, a positive first lens group, a negative second lens group, a positive third lens group, and a positive fourth lens group are arranged in this order from the object side.
Japanese Patent Laid-Open No. 59-5 is a group consisting of a group of which the first, third, and fourth groups are moved to perform zooming, and in particular, the second group is made stronger to increase the power.
It is known from 7213, JP-A-59-57214, and the like.

The aspherical surface is composed of a positive first lens group, a negative second lens group, a positive third lens group, and a fourth lens group, that is, a third lens group for compactness. Japanese Patent Application Laid-Open No. 60-178421 discloses that the spherical aberration and astigmatism generated at that time are corrected by an aspherical surface.

[0004]

However, in the former case, the telephoto ratio at the wide-angle end is about 3.6, which is already the second.
Since the power of the group is particularly strong, if the power is increased to make it more compact, various aberrations will deteriorate. Further, the latter one has a configuration in which various aberrations such as spherical aberration and astigmatism are simultaneously corrected by one aspherical surface.
However, in the third lens group in which the aspherical surface is arranged,
Since the height of the off-axis rays incident on the aspherical surface is not high, the correction ability originally possessed by the aspherical surface cannot be fully exerted.

For this reason, the problem that off-axis aberrations such as astigmatism cannot be corrected sufficiently, and when the power of each group is increased in order to make it more compact, it becomes impossible to correct various aberrations. There is a problem that it will end up. The present invention has been made in view of these problems, and by effectively using an aspherical surface, it is possible to obtain a high-performance zoom lens in which aberrations are well corrected and sufficiently compact. The purpose is to provide.

[0006]

In order to achieve the above object, in a zoom lens according to the present invention, a positive first lens group, a negative second lens group, and a positive third lens group are arranged in order from the object side. It consists of an aperture stop and a positive fourth lens group, and when zooming from the wide-angle side to the telephoto side, the first lens group and the second lens group are used.
A zoom lens in which the distance between the lens groups increases, the distance between the second lens group and the third lens group decreases, and the distance between the third lens group and the fourth lens group decreases, at least the fourth lens group It is characterized by having one aspherical surface and satisfying the following conditions.

0.1 × 10 ⁻⁴ <| C ₄ | <0.1 × 10 ⁻³ (1) However, the aspherical expression is expressed as x = cy ² (1+ (1-c ² y ² ) ^1/2 ) ^-1 ＋ a ₂ y ² ＋
a ₄ y ⁴ ＋ a ₆ y ⁶ ＋ ………… If c = 1 / R, then x is the coordinate in the direction of the optical axis from the apex of the aspheric surface y is the coordinate in the direction of the optical axis R is the paraxial curvature Radius a ₂ , a ₄ , a ₆ ... Aspherical coefficient C ₄ ; Aspherical coefficient a _{4 Further} , in another zoom lens according to the present invention, when the zoom lens is composed of three groups, Three groups, in order, a positive first lens group, a negative second lens group, at least one biconcave single lens, and an imaging lens group having a positive meniscus lens convex on the object side, which is arranged closest to the image plane side. At least one surface of the positive meniscus lens is an aspherical surface, and the shape of the aspherical surface is such that the positive action weakens as the distance from the optical axis increases, and the following conditions are satisfied.

0.1 × 10 ⁻⁴ <| D ₄ | <0.1 × 10 ⁻³ (2) However, the aspherical expression is x = cy ² (1+ (1-c ² y ² ) ^1/2 ) ^-1 ＋ a ₂ y ² ＋
a ₄ y ⁴ ＋ a ₆ y ⁶ ＋ ………… If c = 1 / R, then x is the coordinate in the direction of the optical axis from the apex of the aspheric surface y is the coordinate in the direction of the optical axis R is the paraxial curvature radius _{a 2, a 4, a 6} .........; aspherical coefficients D _4; action reason for adopting the above-described arrangements in the present invention in the following aspheric coefficients a _4, also for the more preferred construction will be described.

In the zoom lens, in order to shorten the overall lens length and make it compact, it is necessary to increase the power of each lens group, but in order to maintain good correction of each aberration, appropriate power distribution should be performed. is important. Therefore, in order to obtain a particularly compact lens system in the zoom lens according to the present invention, it is preferable to satisfy the following conditions.

0.4 <f _RW / f _W <0.8 (3) 0.15 <e _2T / f _W <0.75 (4) where f _W is the focal length at the wide angle end of the entire system and f _RW is The focal length at the wide-angle end of the imaging lens group (the composite group of the third group and the fourth group in the case of the 4-group zoom lens corresponds to the third group in the case of the 3-group zoom lens), e _2T is at the telephoto end. It is the distance between the rear principal point of the second group and the front principal point of the imaging lens group.

Further, the first group is composed of a negative meniscus lens having a convex surface on the object side and a biconvex lens or a cemented lens thereof, and a positive meniscus lens having a convex surface on the object side,
When focusing is performed with the first lens group, it is preferable that the following condition is satisfied, where R is the radius of curvature of the most image-side surface of the first lens group. 1.5 <R / f _W <3.5 (5) Further, by making the most object side surface of the second group convex toward the object side and the most image side surface also convex toward the object side, the second group of off-axis rays can be obtained. It is possible to reduce the variation of off-axis aberrations due to zooming by reducing the angle of incidence and the angle of emergence on. At this time, in the case of a four-group structure, this second lens group is composed of a negative meniscus lens, a biconcave lens, and a cemented positive lens, which are convex toward the object side in order from the object side, or two positive lenses are included. It is more preferable to configure.

Further, by including both a positive lens and a negative lens in each lens group, it is possible to excellently correct chromatic aberration. At this time, since the second group has a strong negative power, it is preferable to use a plurality of negative lenses. Further, due to the lens barrel structure, if the second group having a strong power is fixed during zooming, stable performance can be easily obtained. Also, the first group and the fourth group
If the groups are integrated and zoomed, the lens barrel structure becomes simple.

Next, the operation of the conditions (1) to (5) will be described. Considering correction of off-axis aberrations such as astigmatism using an aspherical surface, it is desirable to dispose the aspherical surface as close to the image plane as possible than the diaphragm. Considering this point is the condition (1). This is because when the zoom lens is composed of four groups, the aspherical surface is appropriately used to make the overall length short and compact by at least one aspherical surface. It is a condition for satisfactorily correcting each aberration.
This condition is that when an aspherical surface is used on the surface close to the image surface of the fourth lens group, the light flux at each image height tends to be separated, the incident angle to the aspherical surface becomes large, and the axial ray height is increased. By utilizing the lowering, it is possible to favorably correct coma and astigmatism while reducing the influence on spherical aberration. If the upper limit of this condition is exceeded, coma and astigmatism will be overcorrected, and axial rays will also be affected, resulting in deterioration of spherical aberration. When the value goes below the lower limit, the effect of the aspherical surface becomes too weak, and it becomes difficult to correct the aberration.

Condition (2) is a conditional expression regarding the shape of the aspherical surface provided on the image side when the zoom lens has a three-group configuration. The conditional expression itself is the same as the condition (1),
Moreover, the tendency of exceeding the lower limit is the same. However, since the imaging lens group is composed of one group, spherical aberration and coma flare cannot be completely corrected if the correction of the field curvature generated in this imaging lens group is corrected by this aspherical surface. The correction is made by providing a biconcave lens in the imaging lens group.

The conditions (3) and (4) are conditions for determining an appropriate power distribution as described above, and if both of them exceed the upper limit, the total lens length becomes long and compactness cannot be achieved. Beyond the lower limit, the power of each group becomes too strong,
Even if the above-mentioned aspherical surface is used, it becomes difficult to correct each aberration. The condition (5) is a condition for obtaining better performance in consideration of focusing as described above. When the value exceeds the upper limit, the fluctuation of distortion due to zooming becomes large. When the value goes below the lower limit, the spherical aberration fluctuates greatly during focusing, and it becomes difficult to match the good image positions of the center and the periphery.

As described above, if the structure of the present invention is adopted, good performance and compactness of the lens system can be achieved by using one aspherical surface. Next, by adopting the above-mentioned structure and further using a single aspherical surface in the vicinity of the diaphragm, further high performance can be achieved. This will be described in detail below. In particular, spherical aberration and astigmatism are problems when a zoom lens of the type according to the present invention is made compact. Therefore, for high performance,
It is desirable to correct the spherical aberration and the astigmatism with independent aspherical surfaces.

Although both spherical aberration and astigmatism produce different amounts of aberration depending on the angle of incidence, in the case of spherical aberration, the ray height of the axial marginal ray is the same as that of the off-axis principal ray in the case of astigmatism. However, the amount of generation is largely controlled. Therefore, if there are independent surfaces in which the axial marginal ray and the off-axis chief ray are completely separated in the lens system, it is possible to individually correct aberrations by making the surfaces aspherical. However, in reality, such an ideal surface does not exist.As a surface close to this, the degree of separation between the on-axis marginal ray and the off-axis chief ray is high, so that the vicinity of the image plane described above is a basic aspherical surface. Selected as the placement position.

In the vicinity of this image plane, since the ray height of the off-axis chief ray is higher than that of the axial marginal ray, the contribution of the aspherical surface to the astigmatism is larger than that to the spherical aberration. As a result, spherical aberration tends to be undercorrected. Therefore, in order to improve the performance of the zoom lens according to the present invention, first, the first aspherical surface arranged near the image plane is sufficiently corrected for astigmatism after recognizing insufficient correction of spherical aberration. A second aspherical surface is arranged in the vicinity of the diaphragm, and the second aspherical surface is configured to sufficiently correct the spherical aberration that is insufficiently corrected in the first aspherical surface. The position of the second aspherical surface is selected near the stop because the height of the axial marginal ray is high at the position of the stop and the off-axis principal line intersects the optical axis, which affects astigmatism. This is because the spherical aberration can be corrected without affecting.

As a result, the astigmatism is sufficiently corrected by the aspheric surface arranged near the image plane, and the spherical aberration is corrected while the influence on the astigmatism corrected by the aspheric surface arranged near the diaphragm is minimized. Can be satisfactorily corrected. When two aspherical surfaces are used, it is more preferable that the aspherical surface on the image side of the two aspherical surfaces satisfies the following condition, astigmatism is favorably corrected.

0.1 × 10 ⁻⁵ <| B ₄ | <0.1 × 10 ⁻³ (6) Furthermore, as the action of the aspherical surface on the image side, there are many surfaces common to the explanation of the above condition (1). Therefore, by satisfying the condition (6), astigmatism can be better corrected. If the upper limit of this condition is exceeded, astigmatism and spherical aberration will be overcorrected. If the lower limits are exceeded, both will be undercorrected.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Each embodiment of the zoom lens of the present invention will be described below. Examples 1, 2, and 4 are positive / negative as shown in the sectional views of the wide-angle end in FIG. 1 and the telephoto end in FIG.
This is a zoom lens that has four groups of negative, positive, and positive lenses and uses two aspherical surfaces. As shown in the sectional view at the wide-angle end in FIG. 3, Embodiments 3 and 5 are zoom lenses using the same positive, negative, positive, and positive four-group structure as described above and two aspherical surfaces. In Examples 1 to 5, the aspherical surfaces are provided on the image side surface of the third lens group closest to the image and on the object side surface of the fourth lens group closest to the image in the vicinity of the diaphragm.

The sixth embodiment has a positive / negative / positive three-group structure as shown in the wide-angle end in FIG. 4 and the telephoto end in FIG.
It is a zoom lens using two aspherical surfaces. Example 7 is a zoom lens using two aspherical surfaces, which has a positive / negative / positive three-group configuration as in Example 6, as shown in the sectional view at the wide-angle end in FIG. In Examples 6 and 7, the aspherical surfaces are provided on the lens object side surface of the third lens group closest to the object and on the image side surface of the third lens group most image side in the vicinity of the diaphragm.

Embodiments 8 and 10 are zoom lenses each having a positive, negative, positive, and positive four-group construction as shown in the sectional views at the wide-angle end in FIGS. In Examples 8 and 10, the aspherical surface is provided on the object side surface of the fourth lens group closest to the image side. Example 9 is the same as Examples 8 and 10 as shown in the sectional view at the wide-angle end in FIG.
This zoom lens has a positive four-group configuration and uses one aspherical surface. Here, the aspherical surface is provided on the image side surface of the fourth lens group closest to the image.

The eleventh and twelfth embodiments have a positive / negative / positive three-group construction similar to the tenth embodiment as shown in the sectional view at the wide-angle end in FIG.
It is a zoom lens using one aspherical surface. Here, the aspherical surface is provided on the image side surface of the positive meniscus lens, which is the most image side lens in the third lens group. The numerical data of each example are shown below.

[0025]

Example 1 f = 35.9 mm to 101.0 mm, F / 3.57 to 4.85, 2ω = 62.0 ° to 24.2 ° r ₁ = 291.8679 d ₁ = 2.5000 n ₁ = 1.80518 ν ₁ = 25.43 r ₂ = 67.6668 d ₂ = 6.8000 _{n 2 = 1.65160 ν 2 = 58.52} r 3 = -173.7374 d 3 = 0.2000 r 4 = 39.1397 d 4 = 4.3000 n 3 = 1.65160 ν 3 = 58.52 r 5 = 94.3469 d 5 = ( variable) r ₆ = 361.1701 d ₆ = 1.7293 n ₄ = 1.77250 ν ₄ ＝ 49.66 r ₇ ＝ 22.8024 d ₇ ＝ 4.8000 r ₈ ＝ -32.6627 d ₈ ＝ 1.7000 n ₅ ＝ 1.74100 ν ₅ ＝ 52.68 r ₉ ＝ 27.9925 d ₉ ＝ 0.5000 r ₁₀ ＝ 28.1629 d ₁₀ ＝ 4.2000 n ₆ = 1.80518 ν ₆ ＝ 25.43 r ₁₁ ＝ -46.7666 d ₁₁ = 1.4000 n ₇ = 1.80400 ν ₇ ＝ 46.57 r ₁₂ ＝ 145.0476 d ₁₂ ＝ (variable) r ₁₃ ＝ 45.6029 d ₁₃ ＝ 2.4509 n ₈ ＝ 1.56873 ν ₈ ＝ 63.16 r ₁₄ = -99.9305 d ₁₄ = 0.4200 r ₁₅ = 38.9381 d ₁₅ = 4.3500 n ₉ = 1.48749 ν ₉ = 70.20 r ₁₆ = -20.6778 d ₁₆ = 1.2000 n ₁₀ = 1.67270 ν ₁₀ = 32.10 r ₁₇ = -162.4476 (non Sphere d ₁₇ = 1.0000 r _18; throttle d ₁₈ = _{(Variable) r 19 = 42.3383 d 19 =} 2.2400 n 11 = 1.61272 ν 11 = 58.75 r 20 = -7900.6178 d 20 = 0.2000 r 21 = 35.8796 d 21 = 3.4000 n 12 = 1.60311 ν ₁₂ = 60.70 r ₂₂ = -67.9577 d ₂₂ = 2.5000 r ₂₃ = -117.6327 d ₂₃ = 1.8537 n ₁₃ = 1.59551 ν ₁₃ = 39.21 r ₂₄ = 24.7948 d ₂₄ = 3.0000 r ₂₅ = -117.2207 (aspherical surface) d ₂₅ = 2.5000 n ₁₄ = 1.72825 ν ₁₄ = 28.46 r ₂₆ = -126.3532

[0026]

[Table 1]

Aspherical lens data (aspherical coefficient) r ₁₇ ; a ₂ = 0, a ₄ = 0.10492 × 10 ^-5 , a ₆ = 0.56608 × 10 ^-8 , a ₈ = -0.12893 × 10 ^-10 , a ₁₀ = -0.21888 x 10 ^-12 r ₂₅ ; a ₂ = 0, a ₄ = -0.23442 x 10 ^-4 , a ₆ = -0.46934 x 10 ^-7 , a ₈ = -0.32520 x 10 ^-9 , a ₁₀ = 0.18599 x 10 ^-12 | B ₄ | / | A ₄ | = 22.3, | B ₄ | = 0.23442 × 10 ^-4 , f _RW / f _W = 0.73, e _2T / f _W = 0.21, R / f _W = 2.63

[0028]

Example 2 f = 35.9 mm to 101.0 mm, F / 3.58 to 4.85, 2ω = 62.0 ° to 24.2 ° r ₁ = 312.2405 d ₁ = 2.5000 n ₁ = 1.80518 ν ₁ = 25.43 r ₂ = 68.8465 d ₂ = 6.8000 _{n 2 = 1.65160 ν 2 = 58.52} r 3 = -174.8560 d 3 = 0.2000 r 4 = 39.7352 d 4 = 4.4500 n 3 = 1.65830 ν 3 = 57.33 r 5 = 98.8411 d 5 = ( variable) r ₆ = 383.5690 d ₆ = _{1.7300 n 4 = 1.77250 ν 4 =} 49.66 r 7 = 23.2093 d 7 = 4.8000 r 8 = -34.7608 d 8 = 1.6000 n 5 = 1.74100 ν 5 = 52.68 r 9 = 31.2002 d 9 = 0.9600 r 10 = 31.0006 d 10 = 4.3500 n ₆ = 1.80518 ν ₆ ＝ 25.43 r ₁₁ ＝ -42.9177 d ₁₁ ＝ 1.2500 n ₇ ＝ 1.80400 ν ₇ ＝ 46.57 r ₁₂ ＝ 102.9517 d ₁₂ ＝ (variable) r ₁₃ ＝ 38.9895 d ₁₃ ＝ 2.6000 n ₈ ＝ 1.56873 ν ₈ ＝ 63.16 r ₁₄ = -102.4423 d ₁₄ = 0.2000 r ₁₅ = 41.0031 d ₁₅ = 4.4500 n ₉ = 1.48749 ν ₉ = 70.20 r ₁₆ = -21.8964 d ₁₆ = 1.2000 n ₁₀ = 1.67270 ν ₁₀ = 32.10 r ₁₇ = -223.1431 (Non Sphere d ₁₇ = 1.0000 r _18; throttle d ₁₈ = _{(Variable) r 19 = 37.8825 d 19 =} 2.5500 n 11 = 1.61272 ν 11 = 58.75 r 20 = 1311.3558 d 20 = 0.2000 r 21 = 34.0968 d 21 = 3.3000 n 12 = 1.60311 v ₁₂ = 60.70 r ₂₂ = -74.9584 d ₂₂ = 1.6800 r ₂₃ = -183.6979 d ₂₃ = 1.8537 n ₁₃ = 1.59551 v ₁₃ = 39.21 r ₂₄ = 22.3495 d ₂₄ = 3.0000 r ₂₅ = -100.2426 (aspheric surface) d ₂₅ = 2.4000 n ₁₄ = 1.72825 ν ₁₄ = 28.46 r ₂₆ = -126.3532

[0029]

[Table 2]

Aspherical lens data (aspherical coefficient) r ₁₇ ; a ₂ = 0, a ₄ = 0.26934 × 10 ^-5 , a ₆ = 0.64609 × 10 ^-8 , a ₈ = -0.44736 × 10 ^-10 , a ₁₀ = -0.22335 x 10 ^-12 r ₂₅ ; a ₂ = 0, a ₄ = -0.24366 x 10 ^-4 , a ₆ = -0.52701 x 10 ^-7 , a ₈ = -0.52501 x 10 ^-9 , a ₁₀ = 0.14229 x 10 ^-11 | B ₄ | / | A ₄ | = 9.0, | B ₄ | = 0.24366 × 10 ^-4 , f _RW / f _W = 0.72, e _2T / f _W = 0.21, R / f _W = 2.75

[0031]

Example 3 f = 35.9 mm to 101.0 mm, F / 3.56 to 4.85, 2ω = 62.0 ° to 24.2 ° r ₁ = 295.3209 d ₁ = 2.5000 n ₁ = 1.80518 ν ₁ = 25.43 r ₂ = 68.0618 d ₂ = 7.0000 _{n 2 = 1.65160 ν 2 = 58.52} r 3 = -178.5938 d 3 = 0.2000 r 4 = 38.9905 d 4 = 4.5000 n 3 = 1.65160 ν 3 = 58.52 r 5 = 94.5204 d 5 = ( variable) r ₆ = 363.5847 d ₆ = 1.7293 n ₄ = 1.77250 ν ₄ ＝ 49.66 r ₇ ＝ 22.6581 d ₇ ＝ 4.8000 r ₈ ＝ -33.2807 d ₈ ＝ 1.7000 n ₅ ＝ 1.74100 ν ₅ ＝ 52.68 r ₉ ＝ 34.5108 d ₉ ＝ 0.5000 r ₁₀ ＝ 32.7693 d ₁₀ ＝ 4.2000 _{n 6 = 1.80518 ν 6 = 25.43} r 11 = -36.6247 d 11 = 1.4000 n 7 = 1.80400 ν 7 = 46.57 r 12 = 125.9131 d 12 = ( _{variable) r 13 = 47.6517 d 13 =} 2.4509 n 8 = 1.56873 ν 8 = 63.16 r ₁₄ = -96.5400 d ₁₄ = 0.4213 r ₁₅ = 36.4698 d ₁₅ = 4.3082 n ₉ = 1.48749 ν ₉ = 70.20 r ₁₆ = -21.1809 d ₁₆ = 0.1000 r ₁₇ = -20.5037 d ₁₇ = 1.2000 n ₁₀ = 1.67270 ν ₁₀ = 32.1 0 r ₁₈ = -193.0274 (aspherical surface) d ₁₈ = 1.0000 r ₁₉ ; aperture d ₁₉ = (variable) r ₂₀ = 40.9151 d ₂₀ = 2.6729 n ₁₁ = 1.61272 ν ₁₁ = 58.75 r ₂₁ = -538.9577 d ₂₁ = 0.2000 r _{22 = 31.3769 d 22 = 2.9680 n} 12 = 1.60311 ν 12 = 60.70 r 23 = -65.9045 d 23 = 2.5000 r 24 = -77.8686 d 24 = 1.8537 n 13 = 1.66998 ν 13 = 39.27 r 25 = 24.8812 d 25 = 3.0000 r ₂₆ = -183.3897 (aspherical surface) d ₂₆ = 2.5000 n ₁₄ = 1.72825 ν ₁₄ = 28.46 r ₂₇ = -126.3532

[0032]

[Table 3]

Aspherical lens data (aspherical coefficient) r ₁₈ ; a ₂ = 0, a ₄ = -0.66216 × 10 ^-6 , a ₆ = 0.43521 × 10 ^-9 , a ₈ = -0.96779 × 10 ^-11 , a ₁₀ = -0.11208 × 10 ^-11 , r ₂₆ ; a ₂ = 0, a ₄ = -0.25648 × 10 ^-4 , a ₆ = -0.47710 × 10 ^-7 , a ₈ = -0.19456 × 10 ^-9 , a ₁₀ = -0.30097 × 10 ^-12 ｜ B ₄ ｜ / ｜ A ₄ ｜ ＝ 3.87, ｜ B ₄ ｜ ＝ 0.25648 × 10 ^-4 , f _RW / f _W = 0.72, e _2T / f _W = 0.20, R / f _W ＝ 2.63

[0034]

Example 4 f = 36.0 mm to 101.0 mm, F / 3.62 to 4.85, 2ω = 62.0 ° to 24.2 ° r ₁ = 306.6968 d ₁ = 2.5000 n ₁ = 1.80518 ν ₁ = 25.43 r ₂ = 68.8581 d ₂ = 6.7000 n ₂ = 1.65160 ν ₂ ＝ 58.52 r ₃ ＝ -176.6059 d ₃ ＝ 0.2000 r ₄ ＝ 39.8074 d ₄ ＝ 4.6200 n ₃ ＝ 1.65830 ν ₃ ＝ 57.33 r ₅ ＝ 98.9843 d ₅ ＝ (variable) r ₆ ＝ 385.2105 d ₆ ＝ 1.7300 n ₄ = 1.77250 ν ₄ ＝ 49.66 r ₇ ＝ 23.0232 d ₇ ＝ 4.8000 r ₈ ＝ -33.9586 d ₈ ＝ 1.6000 n ₅ ＝ 1.74100 ν ₅ ＝ 52.68 r ₉ ＝ 30.8857 d ₉ ＝ 0.9600 r ₁₀ ＝ 30.8824 d ₁₀ ＝ 4.3500 n ₆ = 1.80518 ν ₆ ＝ 25.43 r ₁₁ ＝ -42.2395 d ₁₁ ＝ 1.2500 n ₇ ＝ 1.80400 ν ₇ ＝ 46.57 r ₁₂ ＝ 106.4430 d ₁₂ ＝ (variable) r ₁₃ ＝ 38.1326 d ₁₃ ＝ 2.6000 n ₈ ＝ 1.56873 ν ₈ ＝ 63.16 r ₁₄ = -95.1425 d ₁₄ = 0.2000 r ₁₅ = 42.9543 d ₁₅ = 4.4500 n ₉ = 1.48749 ν ₉ = 70.20 r ₁₆ = -21.5600 d ₁₆ = 1.2000 n ₁₀ = 1.67270 ν ₁₀ = 32.10 r ₁₇ = -223.1585 (Non Sphere d ₁₇ = 1.0000 r _18; throttle d ₁₈ = _{(Variable) r 19 = 39.1054 d 19 =} 2.5500 n 11 = 1.61272 ν 11 = 58.75 r 20 = 2166.2549 d 20 = 0.2000 r 21 = 35.0493 d 21 = 3.3000 n 12 = 1.60311 v ₁₂ = 60.70 r ₂₂ = -69.0344 d ₂₂ = 1.6800 r ₂₃ = -174.3032 d ₂₃ = 1.8537 n ₁₃ = 1.59551 v ₁₃ = 39.21 r ₂₄ = 23.1442 d ₂₄ = 3.0000 r ₂₅ = -100.0752 (aspherical surface) d ₂₅ = 2.4000 n ₁₄ = 1.72825 ν ₁₄ = 28.46 r ₂₆ = -126.3532

[0035]

[Table 4]

Aspherical lens data (aspherical coefficient) r ₁₇ ; a ₂ = 0, a ₄ = 0.29092 × 10 ^-5 , a ₆ = 0.70878 × 10 ^-8 , a ₈ = -0.36492 × 10 ^-10 , a ₁₀ = -0.29267 x 10 ^-12 r ₂₅ ; a ₂ = 0, a ₄ = -0.23987 x 10 ^-4 , a ₆ = -0.52191 x 10 ^-7 , a ₈ = -0.46119 x 10 ^-9 , a ₁₀ = 0.11852 x 10 ^-11 | B ₄ | / | A ₄ | = 8.25, | B ₄ | = 0.23987 × 10 ^-4 , f _RW / f _W = 0.72, e _2T / f _W = 0.22, R / f _W = 2.76

[0037]

Example 5 f = 36.0 mm to 101.0 mm, F / 3.58 to 4.85, 2ω = 62.0 ° to 24.2 ° r ₁ = 252.0551 d ₁ = 2.5000 n ₁ = 1.80518 ν ₁ = 25.43 r ₂ = 65.1512 d ₂ = 7.0000 _{n 2 = 1.65160 ν 2 = 58.52} r 3 = -161.9672 d 3 = 0.2000 r 4 = 37.5457 d 4 = 4.5000 n 3 = 1.65160 ν 3 = 58.52 r 5 = 78.9480 d 5 = ( variable) r ₆ = 532.5586 d ₆ = 1.7293 n ₄ = 1.77250 ν ₄ ＝ 49.66 r ₇ ＝ 22.4685 d ₇ ＝ 4.8000 r ₈ ＝ -29.7002 d ₈ ＝ 1.7000 n ₅ ＝ 1.74100 ν ₅ ＝ 52.68 r ₉ ＝ 45.4110 d ₉ ＝ 0.5000 r ₁₀ ＝ 40.6119 d ₁₀ ＝ 4.2000 _{n 6 = 1.80518 ν 6 = 25.43} r 11 = -29.9067 d 11 = 1.4000 n 7 = 1.80400 ν 7 = 46.57 r 12 = 192.4248 d 12 = ( _{variable) r 13 = 40.9001 d 13 =} 2.4509 n 8 = 1.56873 ν 8 = 63.16 r ₁₄ = -51.4228 d ₁₄ = 0.4213 r ₁₅ = 46.2648 d ₁₅ = 4.3082 n ₉ = 1.48749 ν ₉ = 70.20 r ₁₆ = -22.4313 d ₁₆ = 0.5000 r ₁₇ = -19.8955 d ₁₇ = 1.2000 n ₁₀ = 1.67270 ν ₁₀ = 32.1 0 r ₁₈ = -382.3099 (aspherical surface) d ₁₈ = 1.0000 r ₁₉ ; aperture d ₁₉ = (variable) r ₂₀ = 65.3181 d ₂₀ = 2.6729 n ₁₁ = 1.61272 ν ₁₁ = 58.75 r ₂₁ = -113.4383 d ₂₁ = 0.2000 r _{22 = 33.7189 d 22 = 2.9680 n} 12 = 1.60311 ν 12 = 60.70 r 23 = -71.5852 d 23 = 2.5000 r 24 = -114.3990 d 24 = 1.8537 n 13 = 1.66998 ν 13 = 39.27 r 25 = 25.0369 d 25 = 3.0000 r ₂₆ = -313.9246 (aspherical surface) d ₂₆ = 2.5000 n ₁₄ = 1.72825 ν ₁₄ = 28.46 r ₂₇ = -126.3532

[0038]

[Table 5]

Aspherical lens data (aspherical coefficient) r ₁₈ ; a ₂ = 0, a ₄ = -0.27217 × 10 ^-5 , a ₆ = 0.50299 × 10 ^-8 , a ₈ = -0.18210 × 10 ^-9 , a ₁₀ = -0.50016 x 10 ^-12 r ₂₆ ; a ₂ = 0, a ₄ = -0.18698 x 10 ^-4 , a ₆ = 0.12978 x 10 ^-7 , a ₈ = -0.90959 x 10 ^-9 , a ₁₀ = 0.32874 x 10 ^-11 | B ₄ | / | A ₄ | = 6.87, | B ₄ | = 0.18698 × 10 ^-4 , f _RW / f _W = 0.73, e _2T / f _W = 0.22, R / f _W = 2.20

[0040]

Example 6 f = 36.3 mm to 102.0 mm, F / 3.50 to 4.84, 2ω = 61.6 ° to 24.0 ° r ₁ = 393.7230 d ₁ = 2.5500 n ₁ = 1.80518 ν ₁ = 25.43 r ₂ = 77.2250 d ₂ = 7.0100 n ₂ = 1.60311 ν ₂ ＝ 60.70 r ₃ ＝ -118.4586 d ₃ = 0.1000 r ₄ ＝ 40.5790 d ₄ ＝ 4.2500 n ₃ ＝ 1.69680 ν ₃ ＝ 55.52 r ₅ ＝ 78.3661 d ₅ ＝ (variable) r ₆ ＝ 174.9416 d ₆ ＝ 1.3000 n ₄ = 1.80610 ν ₄ ＝ 40.95 r ₇ ＝ 20.1043 d ₇ ＝ 4.8000 r ₈ ＝ -61.2914 d ₈ = 1.1000 n ₅ ＝ 1.83481 ν ₅ ＝ 42.72 r ₉ ＝ 66.7247 d ₉ ＝ 0.3600 r ₁₀ ＝ 32.6794 d ₁₀ ＝ 3.7900 _{n 6 = 1.80518 ν 6 = 25.43} r 11 = -38.1815 d 11 = 1.5700 r 12 = -24.4385 d 12 = 1.0000 n 7 = 1.80400 ν 7 = 46.57 r 13 = -231.5781 d 13 = ( variable) r _14; stop d ₁₄ = 1.1000 r ₁₅ = 25.0368 _{(aspherical) d 15 = 2.4100 n 8 =} 1.65016 ν 8 = 39.39 r 16 = -908.3515 d 16 = 0.1000 r 17 = 19.9465 d 17 = 2.7600 n 9 = 1.65830 ν 9 = 57.33 r 18 = -264.0 968 d ₁₈ = 0.1200 r ₁₉ = 724.5317 d ₁₉ = 6.7000 n ₁₀ = 1.80518 ν ₁₀ = 25.43 r ₂₀ = 13.5026 d ₂₀ = 2.1000 r ₂₁ = -63.3761 d ₂₁ = 2.2800 n ₁₁ = 1.60311 ν ₁₁ = 60.70 r ₂₂ =- _{35.4653 d 22 = 0.8600 r 23 =} 24.2857 d 23 = 3.2900 n 12 = 1.53172 ν 12 = 48.90 r 24 = 63.0831 ( aspherical)

[0041]

[Table 6]

Spherical lens data (aspherical coefficient) r ₁₅ ; a ₂ = 0, a ₄ = -0.88864 × 10 ⁻⁵ , a ₆ = −0.20553 × 10 ⁻⁷ , a ₈ = −0.16039 × 10 ⁻¹⁰ , a ₁₀ = 0.36641 x 10 ^-12 r ₂₄ ; a ₂ = 0, a ₄ = 0.11255 x 10 ^-4 , a ₆ = -0.103 49 x 10 ^-7 , a ₈ = -0.46647 x 10 ^-10 , a ₁₀ = -0.31622 x _{^{10 -11 | B 4 | / |}} A 4 | = 1.27, | B 4 | = 0.11255 × 10 -4, f RW / f W = 0.77, e 2T / f W = 0.18, R / f W = 2.16

[0043]

Example 7 f = 36.3 mm to 102.0 mm, F / 3.50 to 4.85, 2ω = 61.6 ° to 24.0 ° r ₁ = -351.1978 d ₁ = 2.5500 n ₁ = 1.80518 ν ₁ = 25.43 r ₂ = 77.2250 d ₂ = 7.0100 n ₂ = 1.60311 ν ₂ ＝ 60.70 r ₃ ＝ -155.4196 d ₃ ＝ 0.1000 r ₄ ＝ 49.8532 d ₄ ＝ 4.2500 n ₃ ＝ 1.69680 ν ₃ ＝ 55.52 r ₅ ＝ 272.3135 d ₅ ＝ (variable) r ₆ ＝ 202.5582 d ₆ = 1.3000 n ₄ = 1.80610 ν ₄ ＝ 40.95 r ₇ = 18.6630 d ₇ ＝ 4.8000 r ₈ ＝ -123.1804 d ₈ = 1.1000 n ₅ ＝ 1.83481 ν ₅ ＝ 42.72 r ₉ ＝ 65.1293 d ₉ ＝ 0.3600 r ₁₀ ＝ 28.4356 d ₁₀ ＝ 5.6000 n ₆ = 1.80518 ν ₆ ＝ 25.43 r ₁₁ ＝ -40.4334 d ₁₁ ＝ 1.5700 r ₁₂ ＝ -27.4208 d ₁₂ ＝ 1.0000 n ₇ ＝ 1.80400 ν ₇ ＝ 46.57 r ₁₃ ＝ 1198.1331 d ₁₃ ＝ (variable) r ₁₄ ; Aperture d ₁₄ = 1.1000 r ₁₅ = 15.5915 _{(aspherical) d 15 = 4.1000 n 8 =} 1.65016 ν 8 = 39.39 r 16 = -81.3885 d 16 = 0.1000 r 17 = 37.3048 d 17 = 3.4000 n 9 = 1.65830 ν 9 = 57.33 r 18 = -68. 3920 d ₁₈ = 0.1200 r ₁₉ = -76.1286 d ₁₉ = 4.5000 n ₁₀ = 1.80518 ν ₁₀ = 25.43 r ₂₀ = 11.4644 d ₂₀ = 2.1000 r ₂₁ = 15.7645 d ₂₁ = 3.2900 n ₁₁ = 1.53172 ν ₁₁ = 48.90 r ₂₂ = 51.3460 (Aspherical surface)

[0044]

[Table 7]

Aspherical lens data (aspherical coefficient) r ₁₅ ; a ₂ = 0, a ₄ = -0.25760 × 10 ^-4 , a ₆ = -0.10071 × 10 ^-6 , a ₈ = -0.24203 × 10 ^-9 , a ₁₀ = 0.21849 × 10 ^-12 r ₂₂ ; a ₂ = 0, a ₄ = 0.39273 × 10 ^-4 , a ₆ = 0.11228 × 10 ^-6 , a ₈ = -0.54087 × 10 ^-9 , a ₁₀ = -0.31204 × 10 ^-11 | B ₄ | / | A ₄ | = 15.2, | B ₄ | = 0.39273 x 10 ^-4 , f _RW / f _W = 0.76, e _2T / f _W = 0.11

[0046]

Example 8 f = 36.0 mm to 101.0 mm, F / 3.55 to 4.85, 2ω = 62.0 ° to 24.2 ° r ₁ = 302.6384 d ₁ = 2.1578 n ₁ = 1.76182 ν ₁ = 26.52 r ₂ = 49.5172 d ₂ = 0.0019 _{r 3 = 48.3934 d 3 = 7.4999} n 2 = 1.66672 ν 2 = 48.32 r 4 = -178.2271 d 4 = 0.2028 r 5 = 37.1977 d 5 = 4.4000 n 3 = 1.65160 ν 3 = 58.52 r 6 = 83.5369 d 6 = ( variable _{) r 7 = 287.6988 d 7 =} 1.1680 n 4 = 1.6400 ν 4 = 60.09 r 8 = 21.8080 d 8 = 5.0029 r 9 = -38.0524 d 9 = 2.4000 n 5 = 1.80518 ν 5 = 25.43 r 10 = -18.4836 d 10 = 1.1707 n ₆ = 1.72916 ν ₆ ＝ 54.68 r ₁₁ ＝ 39.0369 d ₁₁ ＝ 1.9989 r ₁₂ ＝ 26.1346 d ₁₂ ＝ 2.4000 n ₇ ＝ 1.80518 ν ₇ ＝ 25.43 r ₁₃ ＝ 29.7372 d ₁₃ ＝ (variable) r ₁₄ ＝ 98.4706 d ₁₄ ＝ _{2.4509 n 8 = 1.56873 ν 8 =} 63.16 r 15 = -64.5651 d 15 = 0.2870 r 16 = 21.7173 d 16 = 4.5000 n 9 = 1.48749 ν 9 = 70.20 r 17 = -24.0000 d 17 = 1.3000 n 10 = 1.72000 ν 10 = 43.70 r _{1 8} = 236.2274 d ₁₈ = 1.0000 r ₁₉ ; Aperture d ₁₉ = (variable) r ₂₀ = 28.6431 d ₂₀ = 2.9200 n ₁₁ = 1.56873 ν ₁₁ = 63.16 r ₂₁ = 1066.5050 d ₂₁ = 0.2000 r ₂₂ = 49.1304 d ₂₂ = 3.2097 n ₁₂ = 1.62041 ν ₁₂ = 60.27 r ₂₃ = -101.4396 d ₂₃ = 2.5000 r ₂₄ = -594.4244 d ₂₄ = 1.8476 n ₁₃ = 1.66446 ν ₁₃ = 35.81 r ₂₅ = 28.3779 d ₂₅ = 1.6246 r ₂₆ = 457.2996 (aspherical surface) d ₂₆ = 2.5000 n ₁₄ = 1.72825 ν ₁₄ = 28.46 r ₂₇ = 1713.8581

[0047]

[Table 8]

Aspherical lens data (aspherical coefficient) r ₂₆ ; a ₂ = 0, a ₂ = -0.33217 × 10 ^-4 , a ₆ = -0.10545 × 10 ^-6 , a ₈ = -0.25371 × 10 ^-9 , a ₁₀ = -0.12635 x 10 ^-11 | C ₄ | = 0.33217 x 10 ^-4 , f _RW / f _W = 0.70, e _2T / f _W = 0.20, R / f _W = 2.33

[0049]

Example 9 f = 36.0 mm to 102.0 mm, F / 3.68 to 4.82, 2ω = 62.0 ° to 24.0 ° r ₁ = 181.7590 d ₁ = 2.0000 n ₁ = 1.78470 ν ₁ = 26.22 r ₂ = 45.9183 d ₂ = 7.0000 n ₂ = 1.72600 ν ₂ = 53.56 r ₃ = -627.4269 d ₃ = 0.2000 r ₄ = 37.9932 d ₄ = 4.0000 n ₃ = 1.72000 ν ₂ = 50.25 r ₅ = 87.8571 d ₅ = (variable) r ₆ = 1261.1377 d ₆ = 1.2000 n ₄ = 1.78590 ν ₄ = 44.18 r ₇ = 18.0110 d ₇ = 5.0000 r ₈ = -33.4090 d ₈ = 2.0000 n ₅ = 1.80518 ν ₅ = 25.43 r ₉ = -20.9855 d ₉ = 1.2000 r ₁₀ = -20.4225 d ₁₀ = 1.2000 n ₆ = 1.77250 ν ₆ ＝ 49.66 r ₁₁ ＝ 24.5290 d ₁₁ ＝ 2.5000 n ₇ ＝ 1.80518 ν ₇ ＝ 25.43 r ₁₂ ＝ 76.8874 d ₁₂ ＝ 1.5000 r ₁₃ ＝ 38.0892 d ₁₃ ＝ 2.0000 n ₈ ＝ 1.69895 ν ₈ ＝ 30. r ₁₄ = 85.9796 d ₁₄ = (variable) r ₁₅ = 42.7340 d ₁₅ = 2.5000 n ₉ = 1.51633 ν ₉ = 64.15 r ₁₆ = -63.4158 d ₁₆ = 0.2000 r ₁₇ = 23.5434 d ₁₇ = 4.5000 n ₁₀ = 1.51633 ν ₁₀ = 64.15 r _{18 = -19.6426 d 18 = 1.3000 n} 11 = 1.68250 ν 11 = 44.65 r 19 = 206.3415 d 19 = 0.5000 r 20 = stop d ₂₀ = _{(Variable) r 21 = 112.0861 d 21 =} 3.0000 n 12 = 1.52249 ν 12 = 59.79 r ₂₂ = -32.4239 d ₂₂ = 0.2000 r ₂₃ = 27.6866 d ₂₃ = 7.0000 n ₁₃ = 1.51633 v ₁₃ = 64.15 r ₂₄ = -22.8333 d ₂₄ = 2.0000 n ₁₄ = 1.80440 v ₁₄ = 39.58 r ₂₅ = 33.6584 (aspherical surface)

[0050]

[Table 9]

Aspherical lens data (aspherical coefficient) r ₂₅ ; a ₂ = 0, a ₄ = 0.27831 × 10 ^-4 , a ₆ = 0.29941 × 10 ^-7 , a ₈ = -0.38690 × 10 ^-10 , a ¹⁰ = -0.13006 × 10 ^-12 ｜ C ₄ ｜ ＝ 0.27831 × 10 ^-4 , f _RW / f _W = 0.64, e _2T / f _W = 0.22, R / f _W = 2.43

[0052]

Example 10 f = 36.0 mm to 101.0 mm, F / 3.68 to 4.83, 2ω = 62.0 ° to 24.2 ° r ₁ = 278.0571 d ₁ = 2.2109 n ₁ = 1.80518 ν ₁ = 25.43 r ₂ = 64.2523 d ₂ = 7.3000 n ₂ = 1.61405 ν ₂ ＝ 54.95 r ₃ ＝ -145.3627 d ₃ ＝ 0.2028 r ₄ ＝ 33.9610 d ₄ ＝ 4.4000 n ₃ ＝ 1.65160 ν ₃ ＝ 58.52 r ₅ ＝ 73.4447 d ₅ ＝ (variable) r ₆ ＝ 227.2921 d ₆ ＝ 1.1680 n ₄ = 1.64000 ν ₄ = 60.09 r ₇ = 16.8484 d ₇ = 4.9951 r ₈ = -36.9833 d ₈ = 2.4551 n ₅ = 1.84666 ν ₅ = 23.78 r ₉ = -24.1831 d ₉ = 1.0000 r ₁₀ = -21.2347 d ₁₀ ＝ 1.1707 n ₆ = 1.72916 ν ₆ ＝ 54.68 r ₁₁ ＝ 48.3081 d ₁₁ ＝ 0.4884 r ₁₂ ＝ 29.8490 d ₁₂ ＝ 3.0000 n ₇ ＝ 1.84666 ν ₇ ＝ 23.78 r ₁₃ ＝ 54.3309 d ₁₃ ＝ (variable) r ₁₄ ＝ 69.6586 d ₁₄ = 2.5000 n ₈ = 1.51728 v ₈ = 69.56 r ₁₅ = -40.4085 d ₁₅ = 0.2000 r ₁₆ = 23.5987 d ₁₆ = 4.5000 n ₉ = 1.51728 v ₉ = 69.56 r ₁₇ = -26.5000 d ₁₇ = 1.3000 n ₁₀ = 1.70154 v ₁₀ = 41.24 r ₁₈ = 118.1083 d ₁₈ = 1.0000 r ₁₉ = Aperture d ₁₉ = (variable) r ₂₀ = 32.4240 d ₂₀ = 3.0000 n ₁₁ = 1.60311 ν ₁₁ = 60.70 r ₂₁ = -96.6813 d ₂₁ = 0.2000 r ₂₂ = 48.7873 d ₂₂ = 3.0000 n _{12 = 1.56873 ν 12 = 63.16 r} 23 = 968.9901 d 23 = 2.0000 r 24 = -41.9955 d 24 = 1.9097 n 13 = 1.72047 ν 13 = 34.72 r 25 = 27.4776 d 25 = 2.6164 r 26 = -1709.3440 ( aspherical) d ₂₆ = 2.6000 n ₁₄ = 1.61293 ν ₁₄ = 37.00 r ₂₇ = -36.5500

[0053]

[Table 10]

Aspherical lens data (aspherical coefficient) r ₂₆ ; a ₂ = 0, a ₄ = -0.14953 × 10 ^-4 , a ₆ = -0.65576 × 10 ^-7 , a ₈ = -0.15217 × 10 ^-9 , a ₁₀ = 0.36986 × 10 ^-12 ｜ C ₄ ｜ ＝ 0.14953 × 10 ^-4 , f _RW / f _W = 0.72, e _2T / f _W = 0.23, R / f _W = 2.04

[0055]

[Embodiment 11] f = 36.3 mm to 102.0 mm, F / 3.56 to 4.87, 2 ω = 61.6 ° to 24.0 ° r ₁ = 2157.3510 d ₁ = 2.5500 n ₁ = 1.80518 ν ₁ = 25.43 r ₂ = 77.2250 d ₂ = 7.0100 n ₂ = 1.60311 ν ₂ ＝ 60.70 r ₃ ＝ -97.6780 d ₃ ＝ 0.1000 r ₄ ＝ 42.1265 d ₄ ＝ 4.2500 n ₃ ＝ 1.69680 ν ₃ ＝ 55.52 r ₅ ＝ 84.5493 d ₅ ＝ (variable) r ₆ ＝ 227.9828 d _{6 = 1.3000 n 4 = 1.80610 ν 4} = 40.95 r 7 = 19.0366 d 7 = 4.8000 r 8 = -59.0564 d 8 = 1.1000 n 5 = 1.83481 ν 5 = 42.72 r 9 = 52.1969 d 9 = 0.3600 r 10 = 31.3963 d 10 = 3.7900 n ₆ = 1.80518 ν ₆ ＝ 25.43 r ₁₁ ＝ -45.6222 d ₁₁ ＝ 1.5700 r ₁₂ ＝ -23.1717 d ₁₂ = 1.0000 n ₇ ＝ 1.80400 ν ₇ ＝ 46.57 r ₁₃ ＝ -76.2904 d ₁₃ ＝ (variable) r ₁₄ ＝ diaphragm _{d 14 = 1.1000 r 15 = 39.8324} d 15 = 2.4100 n 8 = 1.65016 ν 8 = 39.39 r 16 = -251.3243 d 16 = 0.1000 r 17 = 27.1172 d 17 = 2.7600 n 9 = 1.65830 ν 9 = 57.33 r 18 = 171.5496 d ₁₈ = 0.1200 _{19 = 34.7864 d 19 = 3.8300 n} 10 = 1.60311 ν 10 = 60.70 r 20 = 1489.2406 d 20 = 2.0400 r 21 = -70.2050 d 21 = 6.7000 n 11 = 1.80518 ν 11 = 25.43 r 22 = 18.3645 d 22 = 2.1000 r 23 _{= -156.1180 d 23 = 2.2800 n 12} = 1.60311 ν 12 = 60.70 r 24 = -34.1925 d 24 = 0.8600 r 25 = 23.2912 d 25 = 3.2900 n 13 = 1.53172 ν 13 = 48.90 r 26 = 63.3541 ( aspherical)

[0056]

[Table 11]

Aspherical lens data (aspherical coefficient) r ₂₆ ; a ₂ = 0, a ₄ = 0.15029 × 10 ^-4 , a ₆ = 0.17717 × 10 ^-7 , a ₈ = 0.26414 × 10 ^-9 , a ₁₀ = -0.30585 × 10 ^-11 ｜ D ₄ ｜ ＝ 0.15029 × 10 ^-4 , f _RW / f _W = 0.75, e _2T / f _W = 0.24, R / f _W ＝ 2.33

[0058]

Example 12 f = 36.3 mm to 102.0 mm, F / 3.68 to 4.87, 2ω = 61.6 ° to 24.0 ° r ₁ = -3951.1688 d ₁ = 2.5500 n ₁ = 1.80518 ν ₁ = 25.43 r ₂ = 77.2250 d ₂ = 7.0100 n ₂ = 1.60311 ν ₂ ＝ 60.70 r ₃ ＝ -99.3398 d ₃ ＝ 0.1000 r ₄ ＝ 43.5530 d ₄ ＝ 4.2500 n ₃ ＝ 1.69680 ν ₃ ＝ 55.52 r ₅ ＝ 107.1875 d ₅ ＝ (variable) r ₆ ＝ 171.2378 d _{6 = 1.3000 n 4 = 1.80610 ν 4} = 40.95 r 7 = 19.6682 d 7 = 4.8000 r 8 = -58.5154 d 8 = 1.1000 n 5 = 1.83481 ν 5 = 42.72 r 9 = 49.4487 d 9 = 0.3600 r 10 = 31.4924 d 10 = _{3.7900 n 6 = 1.80518 ν 6 =} 25.43 r 11 = -39.8707 d 11 = 1.5700 r 12 = -22.9601 d 12 = 1.0000 n 7 = 1.80400 ν 7 = 46.57 r 13 = -103.9685 d 13 = ( variable) r _14; stop _{d 14 = 1.1000 r 15 = 39.7399} d 15 = 2.4100 n 8 = 1.65016 ν 8 = 39.39 r 16 = -220.6437 d 16 = 0.1000 r 17 = 25.3782 d 17 = 2.7600 n 9 = 1.65830 ν 9 = 57.33 r 18 = 237.5652 d ₁₈ = 0.120 _{0 r 19 = 35.4197 d 19 =} 3.8300 n 10 = 1.60311 ν 10 = 60.70 r 20 = 961.7115 d 20 = 2.0400 r 21 = -63.3939 d 21 = 6.7000 n 11 = 1.80518 ν 11 = 25.43 r 22 = 16.9825 d 22 = 2.1000 _{r 23 = -58.9277 d 23 = 2.2800} n 12 = 1.60311 ν 12 = 60.70 r 24 = -31.0354 d 24 = 0.8600 r 25 = 24.8572 d 25 = 3.2900 n 13 = 1.53172 ν 13 = 48.90 r 26 = 183.9976 ( aspherical)

[0059]

[Table 12]

Aspherical lens data (aspherical coefficient) r ₂₆ ; a ₂ = 0, a ₄ = 0.12308 × 10 ⁻⁴ , a ₆ = 0.13270 × 10 ⁻⁷ , a ₈ = 0.37489 × 10 ⁻⁹ , a ₁₀ = -0.29362 × 10 ^-11 | D ₄ | = 0.12308 × 10 ^-4 , f _RW / f _W = 0.75, e _2T / f _W = 0.22, R / f _W = 2.96 However, f; focal length of the entire system F; F number 2ω; angle of view r _i ; radius of curvature of each surface sequentially from the object side d _i ; thickness of each lens and air spacing n _i from the object side sequentially; d-line of each lens sequentially from the object side Refractive index ν _i ; Abbe number f _W of each lens sequentially from the object side; focal length of the entire system at wide-angle end f _RW ; focal length of imaging lens group at wide-angle end e _2T ; after second group at telephoto end The distance R between the side principal point and the front principal point of the imaging lens group R; the radius of curvature of the most image-side surface of the first lens group. Further, the aspherical surface used in the above embodiment is x on the optical axis direction, and the optical axis. Of the normal direction y, when the paraxial curvature radius and the ^{R, x = cy 2 (1+} (1-c 2 y 2) 1/2) -1 + a 2 y 2 +
a ₄ y ⁴ + a ₆ y ⁶ + ... It is represented by c = 1 / R. _{However, a 2, a 4, a} 6, ......... are aspherical coefficients.

A ₄ is the aspherical surface coefficient a ₄ B ₄ in the first aspherical surface; aspherical surface coefficients a ₄ C ₄ and D ₄ in the second aspherical surface; aspherical surface coefficient a ₄ .

[0062]

As is clear from the aberration curve diagrams of the respective embodiments, the present invention provides a zoom lens in which each aberration is satisfactorily corrected and high performance and compactness are sufficiently achieved. It

[Brief description of drawings]

FIG. 1 is a sectional view of a lens configuration at a wide-angle end according to Examples 1, 2, and 4 of the present invention.

FIG. 2 is a sectional view of a lens configuration at a telephoto end according to Examples 1, 2, and 4 of the present invention.

FIG. 3 is a cross-sectional view of lens configurations at wide-angle ends according to Examples 3 and 5 of the present invention.

FIG. 4 is a sectional view of a lens configuration at a wide-angle end according to Example 6 of the present invention.

FIG. 5 is a sectional view of a lens configuration at a telephoto limit according to a sixth embodiment of the present invention.

FIG. 6 is a sectional view of a lens configuration at a wide-angle end according to Example 7 of the present invention.

FIG. 7 is a sectional view of a lens structure at a wide-angle end according to Example 8 of the present invention.

FIG. 8 is a sectional view of a lens structure at a wide-angle end according to Example 9 of the present invention.

FIG. 9 is a sectional view of a lens structure at a wide-angle end according to Example 10 of the present invention.

FIG. 10 is a sectional view of a lens structure at a wide-angle end according to Examples 11 and 12 of the present invention.

FIG. 11 is an aberration curve diagram for Example 1 of the present invention at the wide-angle end.

FIG. 12 is an aberration curve diagram at an intermediate magnification of Example 1 of the present invention.

FIG. 13 is an aberration diagram for Example 1 of the present invention at the telephoto end.

FIG. 14 is an aberration curve diagram for Example 2 of the present invention at the wide-angle end.

FIG. 15 is an aberration curve diagram at an intermediate magnification of Example 2 of the present invention.

FIG. 16 is an aberration diagram at a telephoto end according to a second embodiment of the present invention.

FIG. 17 is an aberration curve diagram for Example 3 of the present invention at the wide-angle end.

FIG. 18 is an aberration curve diagram at an intermediate magnification of Example 3 of the present invention.

FIG. 19 is an aberration diagram at a telephoto end according to a third embodiment of the present invention.

FIG. 20 is an aberration curve diagram for Example 4 of the present invention at the wide-angle end.

FIG. 21 is an aberration curve diagram at an intermediate magnification of Example 4 of the present invention.

FIG. 22 is an aberration diagram at a telephoto end according to a fourth embodiment of the present invention.

FIG. 23 is an aberration curve diagram for Example 5 of the present invention at the wide-angle end.

FIG. 24 is an aberration curve diagram at an intermediate magnification of Example 5 of the present invention.

FIG. 25 is an aberration diagram for Example 5 of the present invention at the telephoto end.

FIG. 26 is an aberration curve diagram for Example 6 of the present invention at the wide-angle end.

FIG. 27 is an aberration curve diagram at an intermediate magnification of Example 6 of the present invention.

FIG. 28 is an aberration diagram at a telephoto end according to a sixth embodiment of the present invention.

FIG. 29 is an aberration curve diagram for Example 7 of the present invention at the wide-angle end.

FIG. 30 is an aberration curve diagram at an intermediate magnification of Example 7 of the present invention.

FIG. 31 is an aberration diagram at a telephoto end according to a seventh embodiment of the present invention.

FIG. 32 is an aberration curve diagram for Example 8 of the present invention at the wide-angle end.

FIG. 33 is an aberration curve diagram at an intermediate magnification of Example 8 of the present invention.

FIG. 34 is an aberration diagram of Example 8 of the present invention at the telephoto end.

FIG. 35 is an aberration curve diagram for Example 9 of the present invention at the wide-angle end.

FIG. 36 is an aberration curve diagram at an intermediate magnification of Example 9 of the present invention.

FIG. 37 is an aberration diagram at a telephoto end according to a ninth embodiment of the present invention.

FIG. 38 is an aberration curve diagram for Example 10 of the present invention at the wide-angle end.

FIG. 39 is an aberration curve diagram at an intermediate magnification of Example 10 of the present invention.

FIG. 40 is an aberration diagram at a telephoto end of Example 10 of the present invention.

FIG. 41 is an aberration curve diagram for Example 11 of the present invention at the wide-angle end.

FIG. 42 is an aberration curve diagram at an intermediate magnification of Example 11 of the present invention.

FIG. 43 is an aberration diagram at a telephoto end of Example 11 of the present invention.

FIG. 44 is an aberration curve diagram for Example 12 of the present invention at the wide-angle end.

FIG. 45 is an aberration curve diagram at an intermediate magnification of Example 12 of the present invention.

FIG. 46 is an aberration diagram of Example 12 of the present invention at the telephoto end.

[Explanation of symbols]

Claims (2)

[Claims] 1. A zoom lens system comprising a positive first lens group, a negative second lens group, a positive third lens group, a diaphragm, and a positive fourth lens group in order from the object side, and zooms from the wide-angle side to the telephoto side. At this time, the distance between the first lens group and the second lens group increases, the distance between the second lens group and the third lens group decreases, and the distance between the third lens group and the fourth lens group decreases. A zoom lens, wherein the fourth lens group has at least one aspherical surface and satisfies the following conditions. 0.1 × 10 ^-4 <| C ₄ | <0.1 × 10 ^-3 (1) However, the aspherical expression is expressed as x = cy ² (1+ (1-c ² y ² ) ^1/2 ) ^-1 ＋ a ₂ y ² ＋
a ₄ y ⁴ ＋ a ₆ y ⁶ ＋ ………… If c = 1 / R, then x is the coordinate in the direction of the optical axis from the apex of the aspheric surface y is the coordinate in the direction of the optical axis R is the paraxial curvature Radius a ₂ , a ₄ , a ₆ ... Aspherical coefficient C ₄ ; aspherical coefficient a ₄ . 2. A positive first lens group, a negative second lens group, at least one biconcave single lens in order from the object side, and a positive meniscus lens convex on the object side disposed closest to the image side. At least one surface of the positive meniscus lens is an aspherical surface, and the shape of the aspherical surface is such that the positive action is weakened as the distance from the optical axis is satisfied, and the following conditions are satisfied. Zoom lens. 0.1 × 10 ^-4 <| D ₄ | <0.1 × 10 ^-3 (2) However, the aspherical expression is expressed as x = cy ² (1+ (1-c ² y ² ) ^1/2 ) ^-1 ＋ a ₂ y ² ＋
a ₄ y ⁴ ＋ a ₆ y ⁶ ＋ ………… If c = 1 / R, then x is the coordinate in the direction of the optical axis from the apex of the aspheric surface y is the coordinate in the direction of the optical axis R is the paraxial curvature Radius a ₂ , a ₄ , a ₆ ......... Aspherical surface coefficient D ₄ ; Aspherical surface coefficient a ₄ .