JPH08211289A - Compact high variable magnifying power zoom lens - Google Patents

Abstract

PURPOSE: To obtain a high variable magnifying power zoom lens which has an included angle of view of about 76 to 18 deg. and a variable magnifying power ratio of about 3 to 4 and has the optical performance good over the entire variable power region by composing a second lens group of a front group having a negative refracting power and a rear group having a positive refracting power and satisfying specific conditions. CONSTITUTION: This high variable magnifying power zoom lens is composed of, successively from an object side, a first lens group G1 having the positive refracting power, the second lens group G2 provided with the positive refracting power as a whole by integrating the second lens group of the negative refracting power and the third lens group of the positive refracting power in a lens system of a four-group zoom system and a third lens group G3 having the negative refracting power. The power of this zoom lens is varied by changing the spacings between the respective lens groups G1 to G3 . The zoom lens described above is constituted to satisfy the conditions 0.05<ϕ1 /ϕW<0.9, 1.0<ϕ12 W/ϕW<2.0, 2.0<β3 T<5.0; where, ϕ1 is the refracting power of the first lens group G1 ; ϕ12 W is the combined refracting power of the first lens group G1 and the second lens group G2 at the wide angle end; ϕW is the refracting power of the entire system at the wide angle end; β3 T is the lateral magnification of the third lens group G3 at the telephoto end.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compact high variable power zoom lens.

[0002]

2. Description of the Related Art In recent years, full automation of cameras has progressed, and it has been common practice to expand the photographic area by incorporating a zoom lens into a compact camera which is multifunctional and has excellent portability. Therefore, a compact lens system is required because the zoom lens itself is incorporated in the camera system as a photographing optical system.

In this type of lens system, it is not necessary to consider disposing a mirror as in a so-called single-lens reflex camera, and the back focus can be shortened. Therefore, for lens systems with a wide angle of view, such as those for single-lens reflex cameras, there is no need to use a retrofocus type and place the rear main plane position behind the optical system. As a type, it is possible to adopt a refracting power arrangement in which the rear principal plane position is located somewhat toward the object side.

Basically, a multifocal switching type variable magnification optical system including a single focus lens, and Japanese Patent Laid-Open No. 57-2012 are available.
The two-group zoom as described in Japanese Patent No. 13 is also a telephoto type lens system. Further, as an advanced form of the two-group zoom lens, there are provided one in which the specific lens group is divided and an attempt is made to improve aberration correction, and a three-group zoom lens in which the magnification is shared. Furthermore, it consists of four lens groups,
A 4-group zoom lens having a movable group of 3 is disclosed in JP-A-60-57.
No. 814.

[0005]

The zoom lens described above has a variable power ratio of 1.5 to at most 2 and a small aperture ratio, which is not practical.

On the other hand, the present applicant has developed a four-group zoom lens disclosed in Japanese Patent Laid-Open No. 63-43115 in order to improve the zoom ratio and the optical performance. Further, as a simplified structure of this zoom lens, it is disclosed in Japanese Patent Laid-Open No. 63-153511.
The lens system and the like described in Japanese Patent Laid-Open Publication No. 2004-242242 are proposed. These zoom lenses are lens systems having a zoom ratio of about 3 and excellent optical performance over the entire zoom range.

The present invention intends to realize a high zoom ratio accompanied by great difficulty in optical design, and further expands the zoom range in order to further utilize the perspective change for the purpose of drawing to satisfy the practical demand. The system is intended to be further miniaturized.

Therefore, an object of the present invention is to have a comprehensive angle of view of 7
It is an object of the present invention to provide a compact, high zoom ratio zoom lens of a three-group zoom system, which has an optical performance of about 6 ° to 18 ° and a zoom ratio of about 3 to 4 over all zoom range.

[0009]

The zoom lens of the present invention basically starts from the development of the lens system of the above-mentioned Japanese Patent Laid-Open No. 63-153511, and further simplifies the lens frame structure and the focusing system. The objective was achieved as a lens system of a three-group zoom system in consideration of compactness by optimization of.

The lens structure and the behavior of the lens group during zooming are originally from the object side in terms of magnification burden and aberration correction during zooming, especially correction of image plane distortion, and from the object side for the purpose of downsizing the lens system. A lens configuration having positive, negative, positive, and negative refractive power is used as the basic refractive power distribution. When this 4-group zoom method is used as a general solution of the zoom equation,
It has been found that the lens group and the third lens group can perform substantially the same zooming movement and yet have good optical performance. That is, the third group zoom method was found as a special solution among the four group zoom methods.

The zoom lens of the present invention has the above-mentioned structure.
The second lens unit having a negative refracting power and the third lens unit having a positive refracting power in the group zoom type lens system are collectively referred to as one lens unit having a positive refracting power. is there. In this way, in order to achieve a variable power ratio of about 3 to 4 in the three-group zoom system, it is important to appropriately arrange the refractive power of each lens group in order to reduce the size of the lens system. The effect can be further enhanced by the construction of a thick lens and the use of new materials.

The zoom lens according to the present invention is based on the above idea. The first lens group having a positive refractive power, the second lens group having a positive refractive power, and the second lens group having a negative refractive power are arranged in this order from the object side. Three
It is composed of a lens group and changes the distance between the lens groups to perform zooming. In addition, the following condition (1),
It is characterized by satisfying (2) and (3).

(1) 0.05 <φ ₁ / φ _W <0.9 (2) 1.0 <φ _{12 W} / φ _W <2.0 (3) 2.0 <β _3T <5.0 φ ₁ is the refractive power of the first lens group, φ _12W is the combined refractive power of the first lens group and the second lens group at the wide-angle end, φ
_W is the refractive power of the entire system at the wide-angle end, and β _3T is the lateral magnification of the third lens group at the telephoto end.

The zoom lens according to the present invention is characterized by the above-mentioned structure. However, the overall length and outer diameter of the lens system are made small to make the structure compact, and the zoom ratio is further increased. To achieve.

As described above, the present invention analyzes the lens system of the four-group zoom system as shown in FIG. 38, and not only downsizes the lens system, but also examines the mechanism and structure. Based on the fact that there is a solution with a relatively small zoom ratio that is borne during zooming from the wide-angle end to the telephoto end of the third lens unit, and the role of this third lens unit at that time is not the zooming, but the image plane loss. It was found to be in the improvement of the optical performance such as being responsible for the correction of the song.

In this way, it becomes possible to make the second lens group and the third lens group of the four-group zoom one lens group with an appropriate interval on the optical axis.

On the other hand, the effect of correcting the image plane distortion that the third lens group has is to adjust the optical axis interval in the third lens group zoom lens, that is, to give a margin of the telephoto ratio to the lens construction on the telephoto side. Alternatively, a convex meniscus-shaped air lens is provided in a thick lens forming each lens to generate high-order aberrations.

In the three-group zoom type lens system constructed as described above, the combined refractive power of the first lens group G ₁ and the second lens group G ₂ is positive at the wide-angle end, as shown in FIG. Can be considered as one lens group. The subsequent third lens group G ₃ having a negative refractive power constitutes a so-called telephoto type.

As described above, the refractive power arrangement at the wide-angle end is
Basically, it is a telephoto type, and is optimal for constructing a wide-angle end with a short back focus. On the other hand, at the wide-angle end,
Since the focal length is short, it is possible to arrange the refractive power such that the rear principal plane position is relatively behind the lens system. That is, a paraxial arrangement that is compact and has good performance can be achieved.

The conditions (1) and (2) are provided for the above reasons.

The condition (1) defines the refractive power of the first lens group. The first lens group basically considers the influence on the telephoto ratio at the telephoto end and the aberration correction situation in the entire zoom range, as well as the focusing method, rather than the overall length of the lens system at the wide-angle end. There is a need. That is, this condition (1) is a condition that determines an important factor in obtaining a compact and good optical performance while achieving a high zoom ratio.

Here, in a three-group zoom lens as shown in FIG. 4, the refracting power at the wide-angle end is φ _W , and the total length of the lens system is L _W.
Then, the following equation holds. φ _W = φ ₁ (1-e _2W・ φ ₃ ) + (1-e _1W・ φ ₁ ) (φ ₂ + φ ₃ -e ' _2W φ ₂ φ ₃ ) (a) L _W = e _1W + e _2W +1' _W (b) l' _W = {-φ ₁ e _2W ＋ (1-e _1W・ φ ₁ ) (1-e _2W・ φ ₂ )} / φ _W (c) where φ ₁ , φ ₂ , φ ₃ Is the refracting power of the first lens group G ₁ , the second lens group G ₂ , and the third lens group G ₃ , respectively, e _1W is the distance between the principal points of the first lens group G ₁ and the second lens group G _{2 at} the wide-angle end, e _1T is the first lens group G ₁ and the second lens group at the telephoto end.
The main point interval of the lens group G _2, e _2W second lens group G ₂ and the main point interval of the third lens group G _3, e _2T and the second lens group G ₂ at the telephoto end the third lens group at the wide-angle end the main point interval of G _3, l _'W back at the wide-angle end focus, l'
_T is the back focus at the telephoto end.

As can be seen from these paraxial relational expressions, when it is clear that the total length of the lens system is shortest at the wide-angle end as in the present invention, only the wide-angle end should be focused on.
Therefore, for the total length at the telephoto end, a thick-walled structure is assigned in consideration of the zooming movement locus and the movement amount based on the refractive power arrangement.

When the upper limit of the condition (1) is exceeded, the focal length at the wide-angle end, which is determined by the specifications, is constant, so that the refracting power of the first lens group becomes strong and the movement amount during zooming becomes small, so that the entire lens system is reduced. It is preferable because it becomes smaller. However, since the present invention is mainly aimed at increasing the zoom ratio, the telephoto side inevitably enters the telephoto area where the angle of view exceeds about 24 °, so that chromatic aberration occurs and the flatness of the image surface cannot be maintained. . Therefore, it is possible to achieve the object of the present invention by paying attention to the configuration of the thick lens of the first lens group, but in that case, the number of lenses increases and the thickness of the lens becomes large, which is not preferable.

When the value goes below the lower limit of the condition (1), the refractive power of the first lens unit becomes weak, so that the amount of zooming movement from the wide-angle end to the telephoto end becomes large and the total length of the lens system becomes large.
Therefore, it is advantageous in terms of aberration correction, but it is against the object of the present invention, compactness.

As described above, under the condition (1), the zoom ratio is 3 to 4
This is an important condition for determining the refractive power arrangement that balances the optical performance and the total length of the lens system in the zoom lens of the present invention.

The condition (2) defines the combined refractive power of the first lens group G ₁ and the second lens group G ₂ at the wide-angle end. The positive compound system and the negative third lens group constitute a so-called telephoto type, whereby the compactness of the entire system is achieved.

When the paraxial back focus of the third lens group is set and the lateral magnification thereof is set, the refractive power of the third lens group is determined. That is, when the magnification is given, the arrangement of the refractive power is almost determined by the condition (2), and the paraxial arrangement of the entire system can be set.

When the value exceeds the upper limit of the condition (2), it is effective in shortening the total length of the lens system at the wide-angle end, and the amount of movement during zooming to the telephoto end is relatively small. However, the refracting powers of the first lens group G ₁ and the second lens group G ₂ both tend to become strong, making it difficult to balance each aberration, including the correction of image plane distortion, and finally, shooting. This is not desirable because the sensitivity due to decentering in terms of lens performance and quality will increase.

When the value goes below the lower limit of the condition (2), it is advantageous for aberration correction, but it is difficult to shorten the total length of the lens system at the wide-angle end, and the refraction of the third lens group G ₃ that follows is difficult. Since the power becomes weaker, it is necessary to balance aberration correction, and the back side principal plane position enters into the thick lens system of the third lens group, so that the back focus of the lens system becomes short. Therefore, the lens diameter also becomes large, which is contrary to the object of the present invention.

When the conditions (1) and (2) described above are satisfied, the refractive power arrangements of the first lens group and the second lens group, which form the basic framework of the lens system of the present invention, are set.

Further, if the distribution of the refractive power of the third lens group is determined, the paraxial layout of the lens system of the present invention is determined.

In order to determine the distribution of the refractive power of this third lens group, it is important to bear the magnification load during zooming from the wide-angle end to the telephoto end. The refractive power arrangement of the entire system can be determined by the balance between this and the paraxial back focus.

Here, when considering compactness and high magnification at the wide-angle end, the paraxial lateral magnification that the third lens group bears has an important meaning, and also has a great meaning in obtaining good performance. . That is, the condition (3) defines the paraxial lateral magnification (hereinafter referred to as magnification) that the third lens group bears.

The magnification of the third lens unit is directly linked to the magnification change from the wide-angle end to the telephoto end, and is also related to the movement amount itself of the third lens unit during zooming. Therefore, when trying to obtain the same magnification, the magnification of the second lens group changes depending on how the magnification of the third lens group is given, the movement locus during zooming also changes, and the state of aberration correction also changes. .

That is, the basic refractive power arrangement is determined by the conditions (1) and (2), and the basic near power is obtained by giving the magnification of the third lens group at the telephoto end for which the magnification change is to be set under the condition (3). The axial layout is almost determined. Further, by allocating a thick structure to each lens group, the objective is realized by repeatedly reviewing the paraxial structure so as to achieve good imaging performance, desired zoom ratio, and downsizing of the lens system.

When the value exceeds the upper limit of the condition (3), the magnification of the third lens group becomes high, which is preferable for obtaining a high zoom ratio, but the movement amount of the third lens group during zooming becomes large. Further, from the viewpoint of achieving a thick lens configuration with a small number of lenses and increasing the amount of movement of the lens group to obtain a telephoto ratio from the viewpoint of performance, it is not preferable to exceed the upper limit of the condition (3). Further, the lens barrel and the driving mechanism are complicated, resulting in high cost. If the value goes below the lower limit, in order to obtain a high variable magnification, the magnification that the second lens group bears becomes high, and there is relatively little change in the total length of the lens system from the wide-angle end to the telephoto end, which can be made compact. Correction becomes difficult. Therefore, in order to satisfactorily correct aberrations, a gradient index lens must be used together. As described above, since it is difficult to correct aberrations, it is actually difficult to obtain a high zoom ratio, and the zoom ratio becomes about 2 and becomes more difficult.

In the high magnification zoom lens of the present invention,
In particular, in order to further increase the scaling factor, it is desirable to limit the condition (1) to the range of the following condition (1 ′).

(1 ′) 0.05 <φ ₁ / φ _W <0.6 These conditions define the refracting power of the first lens group, and in order to achieve a high zoom ratio, the first lens group It is preferable that each of the group, the second lens group, and the third lens group has a large degree of freedom for independently moving during zooming from the wide-angle end to the telephoto end. In order to provide a large degree of freedom, it is preferable to limit the range to the above condition (1 ′).

If the lower limit of this condition (1 ') is satisfied, the overall length of the lens system will have a margin at the telephoto end, and in terms of optical performance, it is recommended to use the first lens group as a focusing group. If you don't think about it, you can do very well and you can get a high-performance zoom lens with high magnification. If the upper limit is not exceeded, the lens system can be downsized, and in particular, the refractive power can be distributed so that the total length can be shortened on the telephoto side. Then, a compact high-magnification zoom lens can be obtained in combination with the distribution of the refractive power of the second lens group.

Regarding the condition (3), the following condition (3 ')
If it is limited as described above, the scaling factor can be about 3 to 4.

(3 ') 2.5 <β _3T <5.0 In order to obtain a high zoom ratio, it is important to properly select the lateral magnification of the third lens group in terms of optical performance and manufacturing. Condition (3 ')
If the lower limit of is exceeded, it becomes difficult to increase the magnification as described above.

The basic distribution of the refractive power of each lens group can be determined based on the above conditions.

Next, the structure of an actual thick lens will be described.

The refractive power of the first lens group is given by the above-mentioned conditions, but the lens structure is basically composed of a cemented lens of a positive lens and a negative lens.
However, a positive lens may be added to this. Further, the aberration correction effect can be increased by separating the cemented lens and forming a meniscus-shaped air lens between them.

The second lens group is considered to consist of two groups because of its role, and is composed of a negative front group G _2F and a positive rear group G _2R .

The front lens group G _2F in the second lens group is for correcting the distortion aberration and the field curvature of the off-axis aberrations generated in the first lens group, which are difficult to correct only by the rear lens group G _2R. First
Aberrations having the opposite signs to those of the lens groups are generated. Further, with respect to correction of spherical aberration, it has an important role in correction of spherical aberration of color particularly in the telephoto range where the marginal beam diameter becomes large.

The lens structure of the front lens group G _2F is basically arranged by arranging a positive lens and a negative lens from the object side, and a positive lens or a negative lens is further arranged according to the required imaging performance. May be. Or an air lens therebetween by dividing the positive lens or a negative lens of the front group G _2F, it is possible to improve further the performance by using an aspherical lens in the front group G _2F.

The rear group G _2R of the second lens group is the front group G _2F.
Is arranged with an interval D on the optical axis, and basically consists of one negative lens and two positive lenses like a triplet or tesser type. Here, since the first lens group and the second lens group together form an image forming system as a whole, it can be considered that the rear group G _2R constitutes a so-called relay system.

The rear lens group G _2R is located at a position where the marginal luminous flux diameter becomes large in the telephoto range, and it is necessary to make a large contribution to the correction of spherical aberration. In addition, decentering sensitivity and other manufacturing difficulties are involved. It is necessary to make sure that the incident angle or the output angle on each surface does not become large so that

In the zoom lens of the present invention, in order to realize further downsizing, the front lens group G _{2F of} the second lens group G ₂ is used.
It is necessary to reduce the dead space by setting the value of the principal point distance e ′ ₂ of the rear lens group G _2R within a certain range and assigning a thick lens so as to satisfy this paraxial configuration.

In addition, the size of the lens system can be reduced to a second value.
The refracting power of either the front group G _2F or the rear group G _2R of the lens group G ₂ becomes strong, which may lead to performance deterioration. In that case, it is effective to use an aspherical surface or a gradient index lens.

The second lens group of the zoom lens of the present invention comprises
It is composed of a front lens group G _2F having a negative refractive power and a rear lens group G _2R having a positive refractive power. For example, as in Examples 1 to 7 described later, the axial air gaps before and after the aperture stop are provided and the entire length of the lens system. If there is no margin, and a high image quality is aimed at, or a beam splitter or the like is provided to branch the optical path to a light receiving element or a finder optical system, a smaller lens system can be obtained. That is, this makes it possible to further reduce the size as in Examples 8 to 11 described later.

[0054] In order to realize this way miniaturization of the two lens groups of the optical power phi _2F front group G _2F and the rear group G _2R of the front group G _2F in the second lens group G ₂ main The point interval e ′ ₂ etc. may be selected appropriately. Here, the refracting power φ ₂ of the second lens group G ₂ is defined within a certain range by the above condition (2).

The refractive power φ of the rear group G _2R of the second lens group G _2
2R is defined based on the following formula.

Φ _2R = (φ ₂ −φ _2F ) / (1−φ _2F · e ′ ₂ ) The refractive power arrangement of the second lens group G ₂ itself can be regarded as a so-called retrofocus type. That is, by arranging the front lens group G _2F having a negative refractive power in front of the rear lens group G _2R having a positive refractive power, the position of the image forming point from the second lens group G ₂ is lengthened. The position of the object point with respect to the third lens group is lengthened, and the arrangement is advantageous for aberration correction.

Here, the principal point distance e ′ between the front group G _2F and the rear group G _2R
By strengthening the refractive power phi ₂₁ of the front group G _2F with a shorter _2, results in a substantial aperture ratio of the front group G _2F becomes large, somewhat disadvantageous mainly correct spherical aberration at the telephoto end However, it is not so disadvantageous in correcting the off-axis aberration.

Further, since the total length of the lens system is shortened, the outer diameter is generally apt to be large, but the entrance pupil distance of the first lens group is shortened, so that miniaturization can be achieved and the overall size is reduced.

[0059] To achieve further miniaturization From the above, it is desirable to select within a range showing a principal point interval e _'2 the following conditions (4).

(4) 5 <e ' ₂ <20 This condition (4) achieves downsizing of the entire lens system by reducing the overall length at the wide-angle end and the lens outer diameter.

Exceeding the upper limit of this condition is preferable for optical performance, but the total length is somewhat longer. If the value goes below the lower limit, the front group G _2F and the rear group G _2R interfere with each other, which is not preferable.

The third lens group has a negative refracting power, and can be regarded as the rear group of the negative refracting power in a so-called telephoto type lens system. At the wide-angle end, the position of the rear main plane is relatively close to the image plane, and therefore the main plane position does not come to be located in front of the lens system as in the original telephoto type as the entire optical system. However, the characteristics of the telephoto type become more prominent as it approaches the telephoto end. As described in the explanation of the condition (3), when it is considered that the third lens group has a function as a rear conversion lens having a large lateral magnification on the telephoto side, it is effective in the vertical direction at the image plane position. Since it acts as a vertical magnification, it is important to utilize it and at the same time sufficiently control it.

In the lens system of the present invention, since the back focus at the wide-angle end can be shortened by the third lens group, on the contrary, the back focus can become extremely short. Therefore, it is necessary to take care so that the rear principal plane position of the third lens group does not come too close to the object side. Therefore, the third lens group is basically composed of a positive lens and a negative lens. It is possible to configure this with only one negative lens, but unless the refractive power is weakened, the imaging performance cannot be sufficiently improved. However, weakening the refracting power undesirably increases the amount of movement during zooming.

With the above construction, a compact zoom lens with a high zoom ratio, which is the object of the present invention, can be constructed.

[0065]

Embodiments Next, respective embodiments of a compact high variable power zoom lens according to the present invention will be described. Example 1 f = 36.0~102.51, F / 4.5 ~F / 6.9, 2ω = 62 ° ~23.83 ° r 1 = -166.4075 d 1 = 1.8500 n 1 = 1.85026 ν 1 = 32.28 r 2 = 62.2552 d 2 = 1.6845 r _{3 = 55.0491 d 3 = 3.9500 n} 2 = 1.49700 ν 2 = 81.61 r 4 = -220.3122 d 4 = 0.2000 r 5 = 45.8646 d 5 = 4.2500 n 3 = 1.61700 ν 3 = 62.79 r 6 = 164.3370 d 6 = D 1 ( Variable) r ₇ = -104.0826 d ₇ = 1.6200 n ₄ = 1.83481 ν ₄ = 42.72 r ₈ = 18.9433 d ₈ = 1.380 r ₉ = 21.7916 d ₉ = 3.6500 n ₅ = 1.80518 ν ₅ = 25.43 r ₁₀ = -56.3446 d ₁₀ = 1.5000 r ₁₁ = -26.4587 _{(aspherical) d 11 = 1.8500 n 6 =} 1.74400 ν 6 = 44.73 r 12 = -45.7190 d 12 = 4.8500 r 13 = ∞ ( _{stop) d 13 = 2.1500 r 14 =} 115.6110 d 14 = _{2.7500 n 7 = 1.77250 ν 7 =} 49.66 r 15 = -35.8400 d 15 = 0.3000 r 16 = -103.9152 d 16 = 3.3000 n 8 = 1.49700 ν 8 = 81.61 r 17 = -19.6769 d 17 = 0.7500 r 18 = -16.9975 ( non-spherical) d _{18 1.7500 n 9 = 1.80518 ν 9 =} 25.43 r 19 = 163.2352 d 19 = 0.8500 r 20 = 557.4189 d 20 = 4.0000 n 10 = 1.67790 ν 10 = 55.33 r 21 = -19.4399 d 21 = D 2 ( variable) r ₂₂ = 85.7977 _{d 22 = 3.4000 n 11 = 1.78472} ν 11 = 25.68 r 23 = -74.6440 ( _{aspherical) d 23 = 0.2000 r 24 =} -350.7649 d 24 = 1.1000 n 12 = 1.80400 ν 12 = 46.57 r 25 = 39.5546 d 25 = 7.9800 _{r 26 = -16.4027 d 26 = 1.3000} n 13 = 1.80400 ν 13 = 46.57 r 27 = -44.4413 aspherical coefficients (surface No. ^{_{11) A 11 = -0.56568 × 10 -5}} , B 11 = 0.23101 × 10 -7 C 11 = -0.20694 x 10 ^-9 , D ₁₁ = 0.12871 x 10 ^-11 (18th surface) A ₁₈ = -0.12126 x 10 ^-4 , B ₁₈ = 0.44951 x 10 ^-8 C ₁₈ = -0.10654 x 10 ^-9 , D ₁₈ = 0.12613 x 10 ^-11 (23rd surface) A ₂₃ = -0.109 924 x 10 ^-4 , B ₂₃ = 0.20316 x 10 ^-7 C ₂₃ = -0.89838 x 10 ^-10 , D ₂₃ = -0.1919 19 x 10 ^-13 f 36.0 62.50 102.51 D ₁ 2.283 16.780 20.850 D ₂ 18.000 7.500 1.450 φ ₁ / φ _W = 0.1 _{19, φ 12W / φ W =} 1.186, β 3T = 3.186, e '2 = 26.919

Example 2 f = 36 to 102.51, F / 4.5 to F / 6.9, 2ω = 62 ° to 23.83 ° r ₁ = 502.5293 d ₁ = 1.8500 n ₁ = 1.83400 ν ₁ = 37.16 r ₂ = 37.9948 d ₂ = 1.0000 r ₃ = 36.4586 d ₃ = 3.9500 n ₂ = 1.48749 ν ₂ ＝ 70.20 r ₄ ＝ 505.2364 d ₄ ＝ 0.2000 r ₅ ＝ 34.7995 d ₅ ＝ 4.2500 n ₃ = 1.61700 ν ₃ ＝ 62.79 r ₆ ＝ 81.7654 d ₆ ＝ D _{1 (variable) r 7 = -108.8354 d 7 =} 1.6200 n 4 = 1.83481 ν 4 = 42.72 r 8 = 18.9756 d 8 = 1.3080 r 9 = 21.0831 d 9 = 3.6500 n 5 = 1.80518 ν 5 = 25.43 r 10 = -123.0270 d ₁₀ = 1.5000 r ₁₁ = -24.7536 _{(aspherical) d 11 = 1.8500 n 6 =} 1.74400 ν 6 = 44.73 r 12 = -38.2169 d 12 = 4.8500 r 13 = ∞ ( _{stop) d 13 = 2.1500 r 14 =} 76.6588 d 14 _{= 2.7500 n 7 = 1.77250 ν 7} = 49.66 r 15 = -36.4149 d 15 = 0.3000 r 16 = -137.5101 d 16 = 3.3000 n 8 = 1.48749 ν 8 = 70.20 r 17 = -21.0700 d 17 = 0.7500 r 18 = -18.1883 (Non-sphere _{) D 18 = 1.7500 n 9 =} 1.80518 ν 9 = 25.43 r 19 = 180.9686 d 19 = 0.8500 r 20 = 458.6435 d 20 = 4.0000 n 10 = 1.69100 ν 10 = 54.84 r 21 = -20.7155 d 21 = D 2 ( variable) r ₂₂ = 80.7565 d ₂₂ = 3.4000 n ₁₁ = 1.78470 v ₁₁ = 26.30 r ₂₃ = -68.6262 (aspherical surface) d ₂₃ = 0.2000 r ₂₄ = -189.9115 d ₂₄ = 1.1000 n ₁₂ = 1.80300 v ₁₂ = 46.66 r ₂₅ = 35.7987 _{d 25 = 7.9800 r 26 = -16.6678} d 26 = 1.3000 n 13 = 1.80300 ν 13 = 46.66 r 27 = -38.9529 aspherical coefficients (surface No. ^{_{11) A 11 = -0.79645 × 10 -5}} , B 11 = 0.24914 × 10 ^-8 C ₁₁ = -0.88961 x 10 ^-10 , D ₁₁ = 0.16372 x 10 ^-11 (18th surface) A ₁₈ = -0.13873 x 10 ^-4 , B ₁₈ = -0.48202 x 10 ^-8 C ₁₈ = -0.12835 x 10 ^-10 , D ₁₈ = 0.75290 × 10 ^-12 (23rd surface) A ₂₃ = -0.84212 × 10 ^-5 , B ₂₃ = -0.13374 × 10 ^-7 C ₂₃ = 0.34160 × 10 ^-9 , D ₂₃ = -0.12614 ^{× 10 -11 f 36 62.50 102.51 D} 1 2.283 16.780 20.850 D 2 18.000 7.500 1.450 φ 1 _{φ W = 0.113, φ 12W /} φ W = 1.204, β 3T = 3.23511 e '2 = 22.483

Example 3 f = 39.3 to 132.6, F / 4.6 to F / 7.75, 2ω = 57.66 ° to 18.53 ° r ₁ = 1111.6796 d ₁ = 1.7300 n ₁ = 1.83400 ν ₁ = 37.16 r ₂ = 45.9404 d ₂ = _{1.7000 r 3 = 70.0465 d 3 =} 3.6800 n 2 = 1.62041 ν 2 = 60.27 r 4 = 493.3583 d 4 = 0.2100 r 5 = 34.3218 d 5 = 5.8500 n 3 = 1.49700 ν 3 = 81.61 r 6 = -102.1033 d 6 = D _{1 (variable) r 7 = -36.1920 d 7 =} 1.6200 n 4 = 1.83481 ν 4 = 42.72 r 8 = 22.2827 d 8 = 1.3229 r 9 = 28.5155 ( _{aspherical) d 9 = 2.7200 n 5 =} 1.78472 ν 5 = 25.68 r ₁₀ = -45.3406 d ₁₀ = 2.2978 r ₁₁ = -23.7783 d ₁₁ = 1.5300 n ₆ = 1.70000 ν ₆ = 48.08 r ₁₂ = -30.8734 d ₁₂ = 5.9500 r ₁₃ = ∞ (aperture) d ₁₃ = 1.9961 r ₁₄ = -102.2083 _{d 14 = 2.7500 n 7 = 1.61700} ν 7 = 62.79 r 15 = -33.5731 d 15 = 0.3800 r 16 = 66.3498 d 16 = 3.2400 n 8 = 1.61272 ν 8 = 58.75 r 17 = -27.2123 d 17 = 0.5700 r 18 = - 23.5275 _{18 = 1.7500 n 9 = 1.78470 ν} 9 = 26.22 r 19 = 76.9210 d 19 = 0.4800 r 20 = 85.0000 d 20 = 4.6500 n 10 = 1.61720 ν 10 = 54.04 r 21 = -23.2593 ( aspherical) d ₂₁ = D ₂ ( _{variable) r 22 = 488.0762 d 22 =} 3.3500 n 11 = 1.78472 ν 11 = 25.68 r 23 = -37.3997 d 23 = 1.5157 r 24 = -35.7145 d 24 = 1.4500 n 12 = 1.77250 ν 12 = 49.66 r 25 = 44.5594 d 25 _{= 5.2500 r 26 = -25.2038 d 26} = 1.2620 n 13 = 1.73520 ν 13 = 41.08 r 27 = -59.6041 aspherical coefficients (surface No. _{9) A 9 = -0.89555 × 10} -6, B 9 = -0.95694 × 10 - ⁸ C ₉ = 0.37493 × 10 ^-9 , D ₉ = -0.304 414 × 10 ^-11 (21st surface) A ₂₁ = 0.82922 × 10 ^-5 , B ₂₁ = 0.16310 × 10 ^-7 C ₂₁ = -0.20748 × 10 ^-9 , D ₂₁ = 0.90282 × 10 ^-12 f 39.3 89.1 132.6 D ₁ 1.950 14.722 18.077 D ₂ 18.485 5.442 1.450 φ ₁ / φ _W = 0.4166, φ _12W / φ _W = 1.336, β _3T = 3.8, e ' ₂ = 26.288

Example 4 f = 39.3 to 132.6, F / 4.5 to F / 7.71, 2ω = 57.66 ° to 18.53 ° r ₁ = 5475.5289 d ₁ = 1.7200 n ₁ = 1.83400 ν ₁ = 37.16 r ₂ = 50.6199 d ₂ = _{1.2000 r 3 = 79.7805 d 3 =} 3.6500 n 2 = 1.64000 ν 2 = 60.09 r 4 = 413.2292 d 4 = 0.2000 r 5 = 33.4990 d 5 = 5.2500 n 3 = 1.49700 ν 3 = 81.61 r 6 = -110.0606 d 6 = D _{1 (variable) r 7 = -32.0020 d 7 =} 1.6200 n 4 = 1.84100 ν 4 = 43.23 r 8 = 21.9789 d 8 = 1.3080 r 9 = 27.9975 ( _{aspherical) d 9 = 2.7200 n 5 =} 1.78472 ν 5 = 25.68 r _{10 = -41.0641 d 10 = 2.0000 r} 11 = -23.2209 d 11 = 1.8500 n 6 = 1.70000 ν 6 = 48.08 r 12 = -30.0726 d 12 = 3.8500 r 13 = ∞ ( _{stop) d 13 = 2.1500 r 14 =} -232.0353 _{d 14 = 2.7500 n 7 = 1.61800} ν 7 = 63.38 r 15 = -36.8408 d 15 = 0.3500 r 16 = 65.9953 d 16 = 3.2400 n 8 = 1.60881 ν 8 = 58.94 r 17 = -28.2241 d 17 = 0.5850 r 18 = - 24.1104 _{18 = 1.7500 n 9 = 1.78470 ν} 9 = 26.22 r 19 = 52.7043 d 19 = 0.8550 r 20 = 61.9805 d 20 = 4.0000 n 10 = 1.61720 ν 10 = 54.04 r 21 = -22.1366 ( aspherical) d ₂₁ = D ₂ ( Variable) r ₂₂ = 193.4725 d ₂₂ = 3.3500 n ₁₁ = 1.78470 v ₁₁ = 26.22 r ₂₃ = -36.7360 (aspherical surface) d ₂₃ = 0.9500 r ₂₄ = -36.4680 d ₂₄ = 1.4500 n ₁₂ = 1.77250 v ₁₂ = 49.66 r ₂₅ = 40.3314 d ₂₅ = 5.4500 r ₂₆ = -26.1119 d ₂₆ = 1.7500 n ₁₃ = 1.73520 ν ₁₃ = 41.08 r ₂₇ = -69.2496 Aspherical coefficient (9th surface) A ₉ = -0.16572 × 10 ^-5 , B ₉ =- 0.10996 × 10 ^-7 C ₉ = 0.44878 × 10 ^-9 , D ₉ = -0.34885 × 10 ^-11 (21st surface) A ₂₁ = 0.97261 × 10 ^-5 , B ₂₁ = 0.19926 × 10 ^-7 C ₂₁ = -0.36802 × 10 ^-9 , D ₂₁ = 0.20193 × 10 ^-11 (23rd surface) A ₂₃ = -0.68780 × 10 ^-6 , B ₂₃ = 0.99067 × 10 ^-8 C ₂₃ = 0.69513 × 10 ^-10 , D ₂₃ = -0.49493 ^{× 10 -12 f 39.3 89.1 132.6 D} 1 2.090 14.802 18.166 D 2 18.625 5.522 1.539 φ 1 / _{W = 0.4055, φ 12W / φ} W = 1.346, β 3T = 3.8513, e '2 = 21.863

Example 5 f = 39.3 to 131.6, F / 4.6 to F / 7.75, 2ω = 57.66 ° to 18.67 ° r ₁ = 80.7343 d ₁ = 1.9000 n ₁ = 1.83400 ν ₁ = 37.16 r ₂ = 38.4838 d ₂ = 3.2000 r ₃ = -75.7956 d ₃ = 2.8000 n ₂ = 1.64000 v ₂ = 60.09 r ₄ = -90.7971 d ₄ = 0.2000 r ₅ = 32.6398 d ₅ = 5.5000 n ₃ = 1.49700 v ₃ = 81.61 r ₆ = -114.9080 d ₆ = D _{1 (variable) r 7 = -28.6342 d 7 =} 1.7000 n 4 = 1.83481 ν 4 = 42.72 r 8 = 22.4483 d 8 = 1.3200 r 9 = 31.3921 ( _{aspherical) d 9 = 2.8500 n 5 =} 1.78472 ν 5 = 25.68 r ₁₀ = -87.2017 d ₁₀ = 2.3000 r ₁₁ = -105.4924 d ₁₁ = 2.4000 n ₆ = 1.70000 ν ₆ = 48.08 r ₁₂ = -28.8013 d ₁₂ = 5.9800 r ₁₃ = ∞ (diaphragm) d ₁₃ = 2.0000 r ₁₄ = -313.1522 d ₁₄ = 2.7500 n ₇ = 1.61700 v ₇ = 62.79 r ₁₅ = -50.4776 d ₁₅ = 0.3000 r ₁₆ = 109.0157 d ₁₆ = 3.2500 n ₈ = 1.61272 v ₈ = 58.75 r ₁₇ = -49.2713 d ₁₇ = 0.7000 r ₁₈ = -36.6175 d ₁₈ = 1.7500 n ₉ = 1.78472 ν ₉ = 25.71 r ₁₉ = 46.0377 d ₁₉ = 1.0000 r ₂₀ = 82.1062 d ₂₀ = 4.6500 n ₁₀ = 1.61720 ν ₁₀ = 54.04 r ₂₁ = -21.9383 (aspherical surface) d ₂₁ = D _{2 (variable) r 22 = -2777.0227 d 22 =} 3.3500 n 11 = 1.78472 ν 11 = 25.68 r 23 = -41.0373 d 23 = 1.5157 r 24 = -36.7693 d 24 = 1.4500 n 12 = 1.77250 ν 12 = 49.66 r 25 = 45.9942 d ₂₅ = 4.6000 r ₂₆ = -46.8725 d ₂₆ = 1.6000 n ₁₃ = 1.73520 ν ₁₃ = 41.08 r ₂₇ = -110.6815 Aspheric coefficient (9th surface) A ₉ = -0.52873 × 10 ^-5 , B ₉ = -0.68602 × 10 ⁻⁷ C ₉ = 0.18557 × 10 ⁻⁸ , D ₉ = −0.11923 × 10 ⁻¹⁰ (21st surface) A ₂₁ = 0.76464 × 10 ⁻⁵ , B ₂₁ = −0.81476 × 10 ⁻⁷ C ₂₁ = 0.14387 × 10 ^-8 , D ₂₁ = -0.83446 x 10 ^-11 f 39.3 89.1 131.6 D ₁ 1.700 17.965 21.673 D ₂ 20.964 5.793 1.242 φ ₁ / φ _W = 0.33, φ _12W / φ _W = 1.3074, β _3T = 3.7085, e ' ₂ = 69.746

Example 6 f = 39.3 to 131.6, F / 4.6 to F / 7.75, 2ω = 57.66 ° to 18.67 ° r ₁ = 201.3566 d ₁ = 1.7500 n ₁ = 1.83400 ν ₁ = 37.16 r ₂ = 43.2604 d ₂ = 1.7000 r ₃ = 134.5966 d ₃ = 3.7000 n ₂ = 1.60300 ν ₂ = 65.48 r ₄ = -852.0851 d ₄ = 0.2100 r ₅ = 29.1194 d ₅ = 5.8000 n ₃ = 1.49700 ν ₃ = 81.61 r ₆ = -117.0703 d ₆ = D _{1 (variable) r 7 = -27.5859 d 7 =} 1.7000 n 4 = 1.83481 ν 4 = 42.72 r 8 = 18.8682 d 8 = 1.3200 r 9 = 28.8176 ( _{aspherical) d 9 = 2.8500 n 5 =} 1.78472 ν 5 = 25.68 r ₁₀ = -53.7701 d ₁₀ = 2.3000 r ₁₁ = -31.2775 d ₁₁ = 1.8500 n ₆ = 1.70000 ν ₆ = 48.08 r ₁₂ = -21.1532 d ₁₂ = 5.9800 r ₁₃ = ∞ (diaphragm) d ₁₃ = 2.0000 r ₁₄ =- 117.0197 d ₁₄ = 2.7500 n ₇ = 1.61700 ν ₇ = 62.79 r ₁₅ = -40.5176 d ₁₅ = 0.3000 r ₁₆ = 98.8887 d ₁₆ = 3.2500 n ₈ = 1.61272 ν ₈ = 58.75 r ₁₇ = -44.5790 d ₁₇ = 0.5700 r ₁₈ = -24.5454 _{d 18 = 1.7500 n 9 = 1.78472} ν 9 = 25.71 r 19 = 90.1223 d 19 = 0.4000 r 20 = 136.5959 d 20 = 4.6500 n 10 = 1.61720 ν 10 = 54.04 r 21 = -18.1746 ( aspherical) d ₂₁ = D ₂ (Variable) r ₂₂ = -861.0376 d ₂₂ = 3.3500 n ₁₁ = 1.78472 v ₁₁ = 25.68 r ₂₃ = -38.8664 d ₂₃ = 1.5157 r ₂₄ = -35.5994 d ₂₄ = 1.4500 n ₁₂ = 1.77250 v ₁₂ = 49.66 r ₂₅ = 45.9952 d ₂₅ = 5.2500 r ₂₆ = -34.6923 d ₂₆ = 1.2620 n ₁₃ = 1.73520 ν ₁₃ = 41.08 r ₂₇ = -64.4792 Aspheric coefficient (9th surface) A ₉ = 0.16261 × 10 ^-5 , B ₉ = -0.28806 × 10 ^{_{-7 C 9 = 0.13717 × 10 -8}} , D 9 = -0.62948 × 10 -11 ( 21 ^{_{surface) A 21 = 0.11850 × 10 -4}} , B 21 = -0.40165 × 10 -7 C 21 = 0.93423 × 10 - ⁹ , D ₂₁ = -0.41105 × 10 ^-11 f 39.3 89.1 131.6 D ₁ 1.900 14.411 17.110 D ₂ 20.826 5.864 1.270 φ ₁ / φ _W = 0.49, φ _12W / φ _W = 1.307, β _3T = 3.6617, e ' ₂ = 43.331

Example 7 f = 39.37 to 102.69, F / 3.38 to F / 6.4, 2ω = 57.58 ° to 23.79 ° r ₁ = 229.9769 d ₁ = 1.7300 n ₁ = 1.83400 ν ₁ = 37.16 r ₂ = 28.1914 d ₂ = 1.3500 r ₃ = 44.7599 d ₃ = 3.6800 n ₂ = 1.62041 ν ₂ = 60.27 r ₄ = 224.2787 d ₄ = 0.2100 r ₅ = 25.8699 d ₅ = 5.8500 n ₃ = 1.55671 ν ₃ = 58.68 r ₆ = -95.5121 d ₆ = D _{1 (variable) r 7 = -34.8103 d 7 =} 1.6200 n 4 = 1.79500 ν 4 = 45.29 r 8 = 27.5584 d 8 = 1.0200 r 9 = 33.2775 d 9 = 2.7200 n 5 = 1.78472 ν 5 = 25.68 r 10 = -104.1054 d ₁₀ = 1.9200 r ₁₁ = -157.1266 d ₁₁ = 1.5300 n ₆ = 1.69100 ν ₆ = 54.84 r ₁₂ = -40271.8331 d ₁₂ = 5.2660 r ₁₃ = ∞ (diaphragm) d ₁₃ = 3.4720 r ₁₄ = 147.1875 d ₁₄ = 2.7500 n ₇ = 1.63636 ν ₇ = 35.37 r ₁₅ = -30.9280 d ₁₅ = 0.3800 r ₁₆ = 72.4462 d ₁₆ = 3.2400 n ₈ = 1.62230 ν ₈ = 53.20 r ₁₇ = -45.1421 d ₁₇ = 0.8500 r ₁₈ = -18.4663 d ₁₈ = 1 . 7500 n ₉ = 1.74000 ν ₉ = 28.29 r ₁₉ = 28.0593 d ₁₉ = 4.6500 n ₁₀ = 1.62299 ν ₁₀ = 58.14 r ₂₀ = -18.5239 d ₂₀ = D ₂ (variable) r ₂₁ = -45.2119 d ₂₁ = 2.9500 n ₁₁ = 1.78470 v ₁₁ = 26.30 r ₂₂ = -20.9146 d ₂₂ = 1.5500 r ₂₃ = -19.7591 d ₂₃ = 1.4500 n ₁₂ = 1.72916 v ₁₂ = 54.68 r ₂₄ = -102.3405 d ₂₄ = 2.7200 r ₂₅ = -31.4912 d ₂₅ = 1.3000 n ₁₃ = 1.72916 ν ₁₃ = 54.68 r ₂₆ = ∞ f 39.37 62.9 102.69 D ₁ 2.550 12.560 17.590 D ₂ 18.570 9.830 2.820 φ ₁ / φ _W = 0.563, φ _12W / φ _W = 1.321, β _3T = 2.781, e ' ₂ = 21.525

Example 8 f = 39.5 to 102.7, F / 4.65 to F / 6.55, 2ω = 57.4 ° to 23.8 ° r ₁ = 115.2670 d ₁ = 1.4000 n ₁ = 1.83400 ν ₁ = 37.16 r ₂ = 28.8331 d ₂ = 0.7100 r ₃ = 28.2651 d ₃ = 3.4000 n ₂ = 1.60300 ν ₂ ＝ 65.48 r ₄ ＝ 102.8707 d ₄ ＝ 0.2000 r ₅ ＝ 29.0721 d ₅ ＝ 3.8000 n ₃ ＝ 1.55671 ν ₃ ＝ 58.68 r ₆ ＝ -339.3697 d ₆ ＝ D _{1 (variable) r 7 = -19.5695 d 7 =} 1.4000 n 4 = 1.79500 ν 4 = 45.29 r 8 = 33.4856 d 8 = 0.5500 r 9 = 32.5005 d 9 = 2.5000 n 5 = 1.78472 ν 5 = 25.68 r 10 = -70.3092 d ₁₀ = 0.5000 r ₁₁ = -97.0891 d ₁₁ = 1.4000 n ₆ = 1.69100 ν ₆ = 54.84 r ₁₂ = -1305.1334 d ₁₂ = 1.0000 r ₁₃ = ∞ (diaphragm) d ₁₃ = 1.0000 r ₁₄ = -133.7972 d ₁₄ = 2.2500 _{n 7 = 1.63636 ν 7 = 35.37} r 15 = -18.7647 d 15 = 0.2000 r 16 = 38.5688 d 16 = 2.5000 n 8 = 1.62230 ν 8 = 53.20 r 17 = -44.5886 d 17 = 0.8500 r 18 = -16.5161 d 18 = 1.2500 _{9 = 1.74000 ν 9 = 28.29 r} 19 = 33.1126 d 19 = 0.2400 r 20 = 39.7549 d 20 = 3.2500 n 10 = 1.62299 ν 10 = 58.14 r 21 = -16.5460 d 21 = D 2 ( variable) r ₂₂ = -23.9539 d ₂₂ = 2.9500 n ₁₁ = 1.78470 v ₁₁ = 26.30 r ₂₃ = -17.3716 d ₂₃ = 0.8600 r ₂₄ = -24.3055 d ₂₄ = 1.3000 n ₁₂ = 1.72916 v ₁₂ = 54.68 r ₂₅ = -33.1828 d ₂₅ = 2.1000 r ₂₆ =- 18.2661 d ₂₆ = 1.3000 n ₁₃ = 1.72916 ν ₁₃ = 54.68 r ₂₇ = -304.9233 f 39.5 63.2 102.7 D ₁ 2.550 12.560 17.590 D ₂ 18.850 9.830 2.820 φ ₁ / φ _W = 0.596, φ _12W / φ _W = 1.332, β _3T = 2.824, e _'2 = 10.852

Example 9 f = 29.36 to 75.1, F / 4.62 to F / 6.55, 2ω = 72.8 ° to 32.1 ° r ₁ = 85.9422 d ₁ = 1.4000 n ₁ = 1.83400 ν ₁ = 37.16 r ₂ = 27.5784 d ₂ = 0.6500 r ₃ = 27.5225 d ₃ = 4.1000 n ₂ = 1.60300 ν ₂ ＝ 65.48 r ₄ ＝ 107.2895 d ₄ ＝ 0.2000 r ₅ ＝ 32.6753 d ₅ ＝ 4.2000 n ₃ ＝ 1.55963 ν ₃ ＝ 61.17 r ₆ ＝ -352.2657 d ₆ ＝ D _{1 (variable) r 7 = -18.2062 d 7 =} 1.4000 n 4 = 1.79500 ν 4 = 45.29 r 8 = 28.7159 d 8 = 0.5500 r 9 = 43.3677 d 9 = 2.5000 n 5 = 1.80518 ν 5 = 25.43 r 10 = -54.1439 d ₁₀ = 0.5000 r ₁₁ = -61.6568 d ₁₁ = 1.4000 n ₆ = 1.69100 ν ₆ = 54.84 r ₁₂ = -73.5293 d ₁₂ = 1.0000 r ₁₃ = ∞ (diaphragm) d ₁₃ = 1.0000 r ₁₄ = -138.0629 d ₁₄ = 2.2500 _{n 7 = 1.59270 ν 7 = 35.29} r 15 = -17.0525 d 15 = 0.2000 r 16 = 43.9725 d 16 = 2.5000 n 8 = 1.71285 ν 8 = 43.19 r 17 = -33.7692 d 17 = 0.8500 r 18 = -13.9493 d 18 = 1.2500 n ₉ ＝ 1.74000 ν ₉ ＝ 28.29 r ₁₉ ＝ 33.0554 d ₁₉ ＝ 0.3500 r ₂₀ ＝ 36.6402 d ₂₀ ＝ 3.2500 n ₁₀ ＝ 1.60300 ν ₁₀ ＝ 65.48 r ₂₁ ＝ -13.5900 d ₂₁ ＝ D ₂ (variable) r ₂₂ ＝ -32.9569 d ₂₂ ＝ 2.3500 n ₁₁ = 1.80518 ν ₁₁ ＝ 25.43 r ₂₃ ＝ -21.3235 d ₂₃ ＝ 0.1500 r ₂₄ ＝ -47.5616 d ₂₄ = 1.1000 n ₁₂ ＝ 1.74100 ν ₁₂ ＝ 52.68 r ₂₅ ＝ -137.5488 d ₂₅ ＝ 5.0000 r ₂₆ ＝ -16.6330 _{d 26 = 1.1000 n 13 = 1.72916} ν 13 = 54.68 r 27 = -209.0778 f 29.36 48.3 75.1 D 1 1.699 9.028 20.082 D 2 13.962 5.716 0.250 φ 1 / φ W = 0.435, φ 12W / φ W = 1.23, β 3T = 2.376, e _'2 = 12.03

Example 10 f = 36.22 to 102.0, F / 4.65 to F / 6.55, 2ω = 61.7 ° to 23.95 ° r ₁ = 100.2088 d ₁ = 1.4000 n ₁ = 1.83400 ν ₁ = 37.16 r ₂ = 28.3094 d ₂ = _{0.6500 r 3 = 27.7669 d 3 =} 3.4000 n 2 = 1.60300 ν 2 = 65.48 r 4 = 89.0092 d 4 = 0.2000 r 5 = 28.3930 d 5 = 3.8000 n 3 = 1.55963 ν 3 = 61.17 r 6 = -426.2746 d 6 = D _{1 (variable) r 7 = -19.8065 d 7 =} 1.4000 n 4 = 1.79500 ν 4 = 45.29 r 8 = 30.7191 d 8 = 0.5500 r 9 = 32.0073 d 9 = 2.5000 n 5 = 1.80518 ν 5 = 25.43 r 10 = -76.3193 d ₁₀ = 0.5000 r ₁₁ = -106.8207 d ₁₁ = 1.4000 n ₆ = 1.69100 ν ₆ = 54.84 r ₁₂ = -302.6502 d ₁₂ = 1.0000 r ₁₃ = ∞ (diaphragm) d ₁₃ = 1.0000 r ₁₄ = -88.6629 d ₁₄ = 2.2500 _{n 7 = 1.59270 ν 7 = 35.29} r 15 = -17.5588 d 15 = 0.2000 r 16 = 43.3709 d 16 = 2.5000 n 8 = 1.71285 ν 8 = 43.19 r 17 = -39.4877 d 17 = 0.8500 r 18 = -14.7456 d 18 = 1.25 00 n ₉ = 1.74000 ν ₉ = 28.29 r ₁₉ = 34.6451 d ₁₉ = 0.3500 r ₂₀ = 40.2667 d ₂₀ = 3.2500 n ₁₀ = 1.60300 ν ₁₀ = 65.48 r ₂₁ = -14.7039 d ₂₁ = D ₂ (variable) r ₂₂ =- _{25.6419 d 22 = 2.9500 n 11 =} 1.80518 ν 11 = 25.43 r 23 = -18.3466 d 23 = 0.3000 r 24 = -28.5968 d 24 = 1.5000 n 12 = 1.73400 ν 12 = 51.49 r 25 = -38.0285 d 25 = 3.1000 r 26 = -18.0602 d ₂₆ = 1.3000 n ₁₃ = 1.72916 ν ₁₃ = 54.68 r ₂₇ = -11866.4764 f 36.22 60.6 102.0 D ₁ 2.607 13.399 18.440 D ₂ 16.792 7.507 0.472 φ ₁ / φ _W = 0.5506, φ _{12 W} / φ _W = 1.303, _{β 3T = 2.92, e '2} = 11.642

Example 11 f = 30.28 to 77.8, F / 4.65 to F / 6.4, 2ω = 71.1 ° to 31.1 ° r ₁ = 213.8660 d ₁ = 1.4000 n ₁ = 1.83400 ν ₁ = 37.16 r ₂ = 23.8020 d ₂ = _{0.6440 r 3 = 24.3680 d 3 =} 4.9250 n 2 = 1.60300 ν 2 = 65.48 r 4 = 138.7480 d 4 = 0.2020 r 5 = 33.2500 d 5 = 4.8000 n 3 = 1.56013 ν 3 = 46.99 r 6 = -97.1720 d 6 = D ₁ (Variable) r ₇ = -18.4410 d ₇ = 1.4000 n ₄ = 1.79500 ν ₄ ＝ 45.29 r ₈ ＝ 29.9330 d ₈ ＝ 0.5500 r ₉ ＝ 27.8420 d ₉ ＝ 2.5000 n ₅ ＝ 1.80518 ν ₅ ＝ 25.43 r ₁₀ ＝ -74.0800 _{d 10 = 0.4970 r 11 = -71.0280} d 11 = 1.4000 n 6 = 1.69680 ν 6 = 56.49 r 12 = -75.0820 d 12 = 1.0000 r 13 = ∞ ( _{stop) d 13 = 1.0000 r 14 =} -89.7660 ( aspherical) _{d 14 = 2.2500 n 7 = 1.59270} ν 7 = 35.29 r 15 = -18.5670 d 15 = 0.2000 r 16 = 48.1400 d 16 = 2.5000 n 8 = 1.71285 ν 8 = 43.19 r 17 = -28.8620 d 17 = 0.8830 r 18 = - 12.9000 d _{18 = 1.2500 n 9 = 1.74077 ν 9} = 27.79 r 19 = 30.6950 d 19 = 0.3540 r 20 = 34.4110 d 20 = 3.2500 n 10 = 1.60300 ν 10 = 65.48 r 21 = -13.2500 d 21 = D 2 ( variable) r ₂₂ = _{-31.7310 d 22 = 2.3500 n 11 =} 1.80518 ν 11 = 25.43 r 23 = -20.0930 d 23 = 0.1500 r 24 = -35.3150 d 24 = 1.1400 n 12 = 1.73500 ν 12 = 49.82 r 25 = -40.9110 d 25 = 4.0600 r ₂₆ = -15.1790 (aspherical surface) d ₂₆ = 1.1000 n ₁₃ = 1.72916 ν ₁₃ = 54.68 r ₂₇ = 641.4940 Aspherical surface coefficient (14th surface) A ₁₄ = -0.41714 × 10 ^-5 , B ₁₄ = 0.42167 × 10 ^-7 C ₁₄ = 0.92130 × 10 ^-9 , D ₁₄ = 0.17517 × 10 ^-10 (26th surface) A ₂₆ = 0.83684 × 10 ^-5 , B ₂₆ = 0.74530 × 10 ^-7 C ₂₆ = -0.41430 × 10 ^-9 , D ₂₆ = 0.32416 × 10 ^-11 f 30.28 49.1 77.8 D ₁ 1.830 9.310 18.850 D ₂ 14.060 5.850 0.250 φ ₁ / φ _W = 0.392, φ _12W / φ _W = 1.257, β _3T = 2.61, e ' ₂ = 13.197 However r ₁ , r _2, ··· curvature of the lens surfaces Diameter, d
₁ , d ₂ , ... Is the thickness of each lens and the lens interval, n
₁ , n ₂ , ... Is the refractive index of each lens, ν ₁ , ν ₂ ,.
Is the Abbe number of each lens.

Example 1 and Example 2 are the lens configurations shown in FIG. 1, in which the wide-angle end includes an angle of view of about 62 °.

Aberrations at the wide-angle end, the intermediate focal length, and the telephoto end of the first embodiment are as shown in FIGS. 5, 6, and 7, respectively, and aberrations at the wide-angle end, the intermediate focal length, and the telephoto end of the second embodiment are as follows. The situation is as shown in FIGS. 8, 9 and 10, respectively. As is clear from these aberration curve diagrams, it has extremely good optical performance. Further, the diameter of the image point distribution also becomes smaller for each wavelength.

In Embodiments 3 to 6 as well, in the lens configuration shown in FIG. 1, the angle of view at the wide-angle end is about 58 ° to the angle of view at the telephoto end of 18 °.
It is included to the extent. In these embodiments, not only the overall length is short, but the lens outer diameter is small, which is convenient for carrying.

Aberrations at the wide-angle end, the intermediate focal length, and the telephoto end in the third embodiment are shown in FIGS. 11, 12, and 13, respectively, and aberrations at the wide-angle end, the intermediate focal length, and the telephoto end in the fourth embodiment are shown in FIG. 14, FIG. 15, and FIG. 16 show the aberration states at the wide-angle end, the intermediate focal length, and the telephoto end of the fifth embodiment, respectively.
7, FIG. 18, and FIG. 19, the aberration conditions at the wide-angle end, the intermediate focal length, and the telephoto end of the sixth embodiment are as shown in FIGS. 20, 21, and 22, respectively.

The seventh embodiment has a lens configuration shown in FIG. 2 in which the angle of view at the wide-angle end is about 58 °, the aperture ratio is large, and a wide-angle side bright lens system is constructed. In this embodiment, the diameter of the aperture stop is kept constant and the stop mechanism is simplified, while the optical performance is improved.

The aberrations at the wide-angle end, the intermediate focal length, and the telephoto end in this embodiment are as shown in FIGS. 23, 24, and 25, respectively.

Each of the above embodiments is characterized by a high zoom ratio and good imaging performance. Third condition (3)
The lateral magnification of the lens group is high, and the contribution of the vertical magnification to the image plane is also large, which is important in manufacturing. Further, the effect of decentering sensitivity of the third lens group is relatively small, which is also a great advantage. Further, although the refractive power of the first lens group shown in the condition (1) is weak and the magnification is 3 to 4, the imaging performance is extremely good and the telephoto ratio at the telephoto end is reasonable. That is also one of the features.

The eighth embodiment has a lens configuration shown in FIG. 3 and is very small and has good image forming performance.

Aberration conditions at the wide-angle end, the intermediate focal length, and the telephoto end of this embodiment are as shown in FIGS. 26, 27, and 28, respectively.

The ninth and eleventh embodiments also have the lens configuration shown in FIG. 3, and the angle of view at the wide-angle end is about 73 °, which is the widest angle for this type of zoom lens. The aberrations at the wide-angle end, the intermediate focal length, and the telephoto end of the ninth embodiment are shown in FIG.
30 and 31, and the aberrations at the wide-angle end, the intermediate focal length, and the telephoto end of the eleventh embodiment are as shown in FIGS. 35, 36, and 37, respectively.

The tenth embodiment is a high-magnification zoom lens which has a lens configuration shown in FIG. 3 and has an angle of view at the wide-angle end of about 62 ° and a magnification of about 3 and is characterized by miniaturization and imaging performance. .
The aberrations at the wide-angle end, the intermediate focal length, and the telephoto end in this embodiment are as shown in FIGS. 32, 33, and 34, respectively.

In all of the ninth to eleventh embodiments, the axial spacing is reduced even at the wide-angle end, the overall length of the entire system is shortened, the outer diameter of the lens is reduced, and the lens system is greatly downsized.

In each of the above embodiments, an air lens having a strong action is provided in each of the first lens group, the second lens group, and the third lens group, and a high-order aberration generating surface is provided from the viewpoint of aberration correction. Next, we try to achieve a delicate aberration balance while giving a lot of freedom.

In the lens system of the present invention, it is effective to provide an aspherical surface in order to increase the zoom ratio and further improve the performance. That is, by adopting an aspherical surface for the first lens group G ₁ or the second lens group G ₂ , it is possible to reduce the burden on the lens component and weaken the refractive power, so that it is possible to design with a margin and improve the optical performance. You can

As the shape of the aspherical surface, the optical axis direction is taken as the x-axis and the direction perpendicular to the optical axis is taken as the y-axis, and the radius of curvature (radius of the reference spherical surface) of the surface near the optical axis is r _k . Then, it is expressed by the following equation.

However, A _k , B _k , C _k , and D _k are aspherical surface coefficients, and k indicates that the aspherical surface is the k-th surface.

[0092]

The present invention has a positive, positive, and negative three-group structure, in which each lens group moves during zooming, thereby enabling downsizing and high zoom ratio, and an optimal thick lens structure. Thus, a zoom lens having excellent optical performance from the wide-angle end to the telephoto end can be realized. In addition, the second lens group has a feature to make it even smaller, and has a lens system with a wide-angle end angle of view of about 76 °, or conversely with a telephoto end angle of view of 1
It is possible to realize a lens system of about 8 °.

[Brief description of drawings]

FIG. 1 is a sectional view of Embodiments 1 to 6 of the present invention.

FIG. 2 is a sectional view of a seventh embodiment of the present invention.

FIG. 3 is a sectional view of Embodiments 8 to 11 of the present invention.

FIG. 4 is a diagram showing the basic configuration of the present invention and the movement status of each group.

FIG. 5 is an aberration curve diagram at the wide-angle end in Example 1.

FIG. 6 is an aberration curve diagram at the intermediate focal length of Example 1.

7 is an aberration curve diagram of Example 1 at the telephoto end. FIG.

FIG. 8 is an aberration curve diagram at the wide-angle end in Example 2.

FIG. 9 is an aberration curve diagram at the intermediate focal length of Example 2.

FIG. 10 is an aberration curve diagram for Example 2 at the telephoto end.

FIG. 11 is an aberration curve diagram of Example 3 at the wide-angle end.

FIG. 12 is an aberration curve diagram for Example 3 at the intermediate focal length.

FIG. 13 is an aberration curve diagram for Example 3 at the telephoto end.

FIG. 14 is an aberration curve diagram of Example 4 at the wide-angle end.

FIG. 15 is an aberration curve diagram for Example 4 at the intermediate focal length.

FIG. 16 is an aberration curve diagram for Example 4 at the telephoto end.

FIG. 17 is an aberration curve diagram of Example 5 at the wide-angle end.

FIG. 18 is an aberration curve diagram for Example 5 at the intermediate focal length.

FIG. 19 is an aberration curve diagram for Example 5 at the telephoto end.

FIG. 20 is an aberration curve diagram for Example 6 at the wide-angle end.

FIG. 21 is an aberration curve diagram for Example 6 at the intermediate focal length.

22 is an aberration curve diagram for Example 6 at the telephoto end. FIG.

FIG. 23 is an aberration curve diagram for Example 7 at the wide-angle end.

FIG. 24 is an aberration curve diagram for Example 7 at the intermediate focal length.

FIG. 25 is an aberration curve diagram for Example 7 at the telephoto end.

FIG. 26 is an aberration curve diagram for Example 8 at the wide-angle end.

FIG. 27 is an aberration curve diagram for Example 8 at the intermediate focal length.

FIG. 28 is an aberration curve diagram for Example 8 at the telephoto end.

FIG. 29 is an aberration curve diagram for Example 9 at the wide-angle end.

FIG. 30 is an aberration curve diagram for Example 9 at the intermediate focal length.

FIG. 31 is an aberration curve diagram for Example 9 at the telephoto end.

FIG. 32 is an aberration curve diagram for Example 10 at the wide-angle end.

FIG. 33 is an aberration curve diagram for Example 10 at the intermediate focal length.

FIG. 34 is an aberration curve diagram for Example 10 at the telephoto end.

FIG. 35 is an aberration curve diagram for Example 11 at the wide-angle end.

FIG. 36 is an aberration curve diagram for Example 11 at the intermediate focal length.

FIG. 37 is an aberration curve diagram for Example 11 at the telephoto end.

FIG. 38 is a diagram showing the configuration of a conventional four-group zoom lens and the movement of each group.

Claims (1)

[Claims] 1. A first lens group having a positive refracting power, a second lens group having a positive refracting power, and a third lens group having a negative refracting power, which are arranged in this order from the object side. The second lens group is composed of a front group having a negative refracting power and a rear group having a positive refracting power, and the following conditions are satisfied. Compact high-magnification zoom lens characterized by satisfying. (1) 0.05 <φ ₁ / φ _W <0.9 (2) 1.0 <φ _{12 W} / φ _W <2.0 (3) 2.0 <β _3T <5.0 (4) 5 < e ′ ₂ <20 where φ ₁ is the refractive power of the first lens group, φ _12W is the combined refractive power of the first lens group and the second lens group at the wide-angle end,
φ _W is the refractive power of the entire system at the wide-angle end, β _3T is the lateral magnification of the third lens unit at the telephoto end, and e ′ ₂ is the distance between the principal points of the front and rear groups.