JPH06194572A - Variable power lens - Google Patents

Abstract

PURPOSE:To provide the variable power lens which is of high variable powers and is bright and compact with a smaller number of constituting elements by adequately setting the refracting power of first and second lens components. CONSTITUTION:This variable power lens has, successively from an object side, the first lens component having the positive refracting power, the second lens component having the negative refracting power, the third lens component having the positive refracting power and the fourth lens component having the positive refracting power and satisfies equation 0.10<=fs.phi1<=0.25 and equation 0.45<fs¦phi2¦<1.25. In the equations, fs is the focal length of the entire system at a wide angle end; phi1 is the refracting power of the first lens component; phi2 is the refracting power of the second lens component. The second lens component of this variable power lens is movable forward and backward on the optical axis for the purpose of varying the power. The third lens component is likewise movable forward and backward on the optical axis in the opposite direction of the 2nd lens component for the purpose of varying the power. The fourth lens component is movable forward and backward by drawing a U-turn-shaped locus on the optical axis in order to maintain the specified position of the image plane at the time of varying the power.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable power lens having a large variable power ratio applied to a small camera such as a video camera.

[0002]

2. Description of the Related Art In recent years, the body of a camera such as a video camera has been remarkably made compact both in weight and volume due to packaging of electronic parts and improvement in integration rate. On the other hand, the price and cost of the camera body are extremely low.

Under such circumstances, the weight, volume and cost of the lens are gradually improved in absolute value. However, the relative value to the camera body is increasing year by year. Therefore, there is a strong demand for compact lenses and cost reduction.

Further, the performance required of the lens is such that a large aperture ratio is provided to make up for the lack of illuminance due to the miniaturization of the image pickup device, and further high performance is provided to cope with higher pixel count and higher resolution. It is getting higher.

Basically, in the present invention, a variable power lens having a large aperture ratio of about 12 times and an F number of about F1.8, which is the current mainstream in the field of video cameras, is assumed in the present invention.

A zoom lens composed of four or five components satisfies such specifications.
Many proposals have been made so far, such as Japanese Patent No. 17, but most of them are composed of about 13 to 15 lenses, and it cannot be said that the present requirements can be satisfied in terms of cost and size.

Further, in a lens for a single-lens reflex camera, as proposed in Japanese Unexamined Patent Publication (Kokai) No. 2-66509, by moving multiple components, the amount of movement of each lens component is reduced to achieve compactness. Many are seen. In such a type, the first lens component is also moved during zooming, but it is much better to fix the heavy first lens component during zooming because it is important to make the drive part compact in a video camera. It is advantageous.

Therefore, in recent video cameras, a movement such as reducing the number of components by using an aspherical surface has been observed. For example, JP-A-57-272
The zoom lens disclosed in Japanese Patent Laid-Open No. 19 is a system composed of three components, positive and negative, and a first lens component as an image point position correction component (compensator) and a second lens component as a variable power component (variator) as an optical axis. By moving up and using one aspherical surface for each lens component, we have realized a 3x zoom lens of F1.6 with 12 lenses. However, it cannot be said that the zoom configuration, lens shape, arrangement, etc. are effective for this, and the number of components is not small considering the specifications.

Further, it is impossible to extend this type of lens to a high zoom ratio of 6 times or more. One of the reasons is that it has the following defects in addition to the inadequacy of the lens shape and arrangement described above. That is, since the third lens component is not moved during zooming, the first lens component inevitably moves as a compensator lens component, and at that time, in order to achieve a high zoom ratio of 6 times or more, Considering use at the edge or middle range (intermediate focal length), for a zoom lens composed of 4 and 5 components,
This is because the diameter of the first lens component (front lens) becomes considerably large and the weight becomes considerably heavy.

On the other hand, in a four-component zoom lens, the lens shape / arrangement and aspherical surface arrangement are considerably effective, and the number of constituent elements is greatly reduced, as disclosed in JP-A-61-110112 and JP-A-60. -107013 has been proposed.

The lens proposed in Japanese Unexamined Patent Publication No. 61-110112 is a four-component system of positive, negative, negative, and positive, and each lens component is simply constructed and the aspherical surface of the four surfaces is used well to make the entire system. Achieving a 6x zoom lens with only 8 lenses. However, the aberration performance is rather poor, and it is difficult to satisfy the current required performance.

Further, Japanese Patent Laid-Open No. 60-107013 discloses a schematic diagram of a structure of 8 sheets of positive, negative, positive, and positive four-component system, but because of the absence of numerical data, its performance and size cannot be judged. ,
Also, in terms of specifications, it is expected that it cannot be applied to high-magnification zooming because it is a 4x zoom of F2.

In addition, although it has a low zoom ratio, it is disclosed in JP-A-63-3.
JP 04218, JP 64-44907 A, JP 1-223408 A
No. 1, one lens for the second lens component and one lens component for the first lens
It has also been proposed that the positive and negative positive three-component system with ~ 2 sheets drastically reduce the number of sheets while also borrowing the power of the aspherical surface. However, in these lens types, the second lens component, which is the main component of zooming and moves greatly on the optical axis during zooming, is composed of one negative single lens, and correction of chromatic aberration in the second lens component is possible. Since it is not done, the variation of chromatic aberration due to zooming is large, and the performance cannot be guaranteed when applied to high zooming. In fact, in these examples, the zoom ratio is as low as 2 to 3 times, and the F number is only F2 to about 4 which is dark. This variation in chromatic aberration cannot be improved even if a lot of aspherical surfaces are used, and such a lens type is expected to achieve a zoom ratio of at most 3 times in consideration of the currently required performance (including chromatic aberration). Without, it is impossible to apply to the 12 times class.

Furthermore, Japanese Patent Laid-Open No. 64-91110 and Japanese Patent Laid-Open No.
The 185608 publication also proposes a novel zoom lens. Japanese Unexamined Patent Publication No. 64-91110 has a lens shape similar to that of a three-component zoom lens, but the portion corresponding to this second lens component is a negative component consisting of two negative lenses and
By separating into a component composed of one positive lens, the substantial constitution is made into a four-component system, and the number of constituent components is as high as three components.
It achieves 3x zoom even with ~ 11 images. The scaling is performed by independently moving the negative component and the positive component described above. However, the essential weakness of this four-component zoom lens is that the high-magnification zoom is achieved because color correction is not completed within each of the second lens component and the third lens component that move independently. When applied, the variation in chromatic aberration due to zooming cannot be sufficiently suppressed. In this example, the variation of the chromatic aberration is managed by controlling the zoom solution by keeping the zoom ratio as low as 3 ×, but it is quite difficult to apply this to the 6 × zoom.

Japanese Unexamined Patent Publication (Kokai) No. 1-185608 is developed to a 6 × zoom while reducing the number of constituent lenses proposed in Japanese Unexamined Patent Publication (Kokai) No. 64-91110 by using a lot of aspherical surfaces. . This is a lens proposed in Japanese Patent Laid-Open No. 64-91110, in which the second lens component is one negative single lens, the third lens component is one positive single lens, and the fourth lens component is also simplified. . However, even in this case, since the above-mentioned variation in chromatic aberration is large, although the zoom solution is considerably devised, the residual chromatic aberration is still large and it is difficult to satisfy the current required performance. In addition, since the zoom solution puts a considerable weight on chromatic aberration correction, the amount of movement of the second lens component and the third lens component, which are moving lens components, is considerably large, and the total length is particularly long. Since the outer diameter of the front lens, which has a large effect on weight, is considerably larger than the existing standard one with the same specifications,
From the point of view of compactness, it must be said that the proposal here is getting worse. In this way, the zoom lens proposed in Japanese Patent Laid-Open No. 1-185608 has achieved the purpose of reducing the number of lenses, but it is compact and
It is concluded that chromatic aberration performance does not meet the current needs.

Further, as in Japanese Patent Laid-Open No. 1-185608, there is one disclosed in Japanese Patent Laid-Open No. 2-39011 that can suppress variation in chromatic aberration with a configuration of four components of positive, negative, positive and positive. This is achieved by using 3 aspherical surfaces and a 6x zoom of F1.4 with 8 lenses, which can be realized from the cost, performance and size aspects of the above examples. It seems to be highly effective. However, the remaining problems are that the diameter of the front lens is not small and there is no significant advantage in weight compared to the existing ones, and that the coma aberration in the sagittal direction (linen Ferrer) is very large and off-axis performance degradation is significant. The four-component zoom lens is expected to gradually improve these problems on this extension line.

In addition, the number of lenses is reduced by moving each lens component in a positive / negative positive three-component system to achieve a high zoom ratio. As a proposal for a single-lens reflex camera or a compact camera, JP-A-54-30855, JP-A-54-801
Some are disclosed in Japanese Patent Laid-Open No. 43-43116 and one disclosed in Japanese Patent Laid-Open No. 2-39116. The zoom ratio and the number of constituent lenses are 2.4 × / 10, 3/11, and 3/12, respectively, and the zoom ratio is insufficient and especially the second lens component and the third lens component The simplification is not sufficiently achieved, and the cost is not sufficient.

[0018]

The present invention has a variable power ratio of 1
It is an object of the present invention to provide a highly variable and bright variable power lens having an F number of approximately 1.8 and a high power of 1.8, which is compact and has a small number of components, and which is sufficiently satisfactory in terms of performance.

[0019]

In order to achieve the above object, in the present invention, in order from the object side, a first lens component having a positive refractive power, a second lens component having a negative refractive power, and a second lens component having a positive refractive power are arranged. In the variable power lens having the third lens component and the fourth lens component having a positive refractive power, the refractive powers of the first lens component and the second lens component are appropriately defined.

Further, the second, third, and fourth positions during zooming
The movement of each lens component was properly specified.

[0021]

With the above structure, the present invention realizes a high-magnification and bright variable-magnification lens with a variable power ratio of about 12 and an F-number of about 1.8, although the present invention is compact and has a small number of components. it can.

[0022]

EXAMPLES Examples of the present invention will be described in detail below. The variable power lens of the present invention comprises, in order from the object side, a first lens component having a positive refractive power, a second lens component having a negative refractive power, a third lens component having a positive refractive power, and a fourth lens component having a positive refractive power. It has a lens component and satisfies the following conditional expressions (1) and (2).

0.10 ≦ fs · φ1 ≦ 0.25 (1) 0.45 <fs · | φ2 | <1.25 (2) where fs is the focal length of the entire system at the wide-angle end, and φ1 is the first
The refracting power of the lens component and φ2 is the refracting power of the second lens component.

Conditional expression (1) defines an appropriate range of the refractive power of the first lens component. In a four-component lens system, it is impossible to realize a zoom lens with a high zoom ratio, which has good aberration performance over the entire focal length range, unless the aberrations generated in each lens component are properly suppressed. When the upper limit of conditional expression (1) is exceeded and the refracting power of the first lens component becomes strong, the amount of aberration generated in the first lens component becomes large, so that the aberration variation of the entire system due to zooming also becomes large. Therefore, the required performance cannot be met. Compared to the telephoto end or wide-angle end, it is used less frequently near the middle, but if the performance is extremely poor,
It is unacceptable for modern lenses, which are required to have higher performance and specifications.

When the lower limit of conditional expression (1) is exceeded and the refractive power of the first lens component becomes weak, the distance between the first lens component and the second lens component, which must be taken for zooming, becomes extremely long. Therefore, the total length of the lens also becomes extremely long. Since the video camera itself has been downsized, recent lens systems are required to be more compact along with specifications and performance. For this reason, no matter how high the performance or specifications are, a lens system with a remarkably long overall length cannot be perfectly balanced with the camera.

Conditional expression (2) defines an appropriate range of the refractive power of the second lens component. Similar to the case of the first lens component, the aberration generated in the second lens component also greatly contributes to the aberration variation in the entire focal length range. When the upper limit of conditional expression (2) is exceeded and the refracting power of the second lens component becomes strong, the aberration generated in the second lens component becomes large, and the aberration fluctuation of the entire system due to zooming becomes significantly large. In addition, since the second lens component mainly performs zooming, it has a particularly strong refractive power, which greatly affects the aberration correction of the third lens component and the fourth lens component, making it difficult to realize a bright lens system. .

When the lower limit of conditional expression (2) is exceeded and the refracting power of the second lens component becomes weak, the amount of movement of the second lens component due to zooming becomes large and the total lens length becomes extremely long. Since the second lens component moves mainly for zooming, its contribution to the total length is significant.

Also, in the variable power lens of the present invention, the second lens component is movable back and forth on the optical axis for variable power, and
The lens component is also movable back and forth on the optical axis in the opposite direction to the second lens component for zooming, and the fourth lens component is the optical axis for keeping the image plane position constant during zooming. U on top
It is characterized by being able to move back and forth while drawing a turn-shaped trajectory.

As described above, by moving each lens component during zooming, it is possible to share the zooming effect with the third component as well, and it is possible to prevent the total length from increasing due to the movement of the third lens component. It

Furthermore, it is desirable that both the second lens component and the third lens component move linearly. Generally, in a zoom lens, the smaller the number of moving lens components, the simpler the mechanism and the more compact. However, if a plurality of lens components can be moved using one mechanism, a simple mechanism can be achieved even if the number of moving lens components is relatively large. By linearly moving the second lens component and the third lens component as described above,
The two moving lens components can be relatively easily moved by one mechanism via the lead or the like.

Further, it is desirable that the variable power lens of the present invention satisfies the following conditional expression (3).

0.10 <φ1 / | φ2 | <0.35 (3) Conditional expression (3) defines an appropriate balance of the refractive power distributions of the first lens component and the second lens component. The number of lenses in the entire system largely depends on the balance of the refractive powers of the first lens component and the second lens component.

When the upper limit of conditional expression (3) is exceeded and the refracting power of the first lens component becomes strong, the locus of the fourth lens component for correcting the image plane position is closer to the object side at the wide-angle end than at the telephoto end, and The position on the object side becomes closer to the third lens component.
When the distance between the third lens component and the fourth lens component decreases, the width of the light beam incident on the fourth lens component increases,
The amount of aberration that must be corrected by the lens component increases, and the number of lenses of the third lens component and the fourth lens component increases.

When the lower limit of conditional expression (3) is exceeded and the refractive power of the second lens component becomes strong, the locus of the fourth lens component shifts toward the image side at the wide-angle end rather than at the telephoto end, and the lens back becomes shorter. The total lens length may become longer. Video lenses require longer lens backs than single-lens reflex cameras. This is because a thick flat plate such as a low-pass filter or a face plate is inserted on the image side of the lens. Recently, the screen size (CCD size) has tended to become smaller, but the thickness of the face plate covering the CCD has hardly changed, so the ratio of the lens back to the total length of the lens is becoming larger and larger. That is, if the lens back becomes extremely short, the lens system itself may not be realized. Of course, it is possible to lengthen the lens back to some extent by changing the number of lens components, but for that purpose, the number of lenses must be significantly increased.

Further, the first lens component is composed of two or more lenses including at least one negative lens of high dispersion material, and the second lens component is composed of two or more lenses including at least one positive lens of high dispersion material. It is preferable that the fourth lens component is composed of two or more lenses including at least one negative lens made of a high dispersion material.

Further, it is desirable that the variable power lens of the present invention satisfy the following conditional expressions (4) to (6).

Ν1N <30 (4) ν2P <30 (5) ν3N <30 (6) where ν1N is the Abbe number of the negative high-dispersion lens in the first lens component, and ν2P is positive in the second lens component. Is the Abbe number of the high-dispersion lens, and ν3N is the Abbe number of the negative high-dispersion lens in the third lens component.

Conditional expressions (4) to (6) relate to correction of chromatic aberration of each lens component. In a zoom lens, chromatic aberration must be corrected within each lens component regardless of the lens type. This is because the relative position of each lens component changes greatly with zooming.If chromatic aberration in each lens component is not corrected or is insufficient, chromatic aberration varies greatly due to zooming. As a result, the required performance cannot be met. This tendency becomes more remarkable as the zoom ratio increases, and chromatic aberration correction must be properly performed when the zoom becomes 8 times or more. If the Abbe's number exceeds the upper limits of conditional expressions (4) to (6), the ability to correct chromatic aberration in each lens component becomes insufficient, and variation in chromatic aberration due to zooming exceeds an allowable amount.

It is desirable that the first lens component is composed of a total of two lenses, a negative meniscus lens and a positive lens, in order from the object side. When the first lens component is composed of the smallest number of lenses, at least two lenses are necessary because it is necessary to correct the chromatic aberration within each lens component as described above. However, if the shape and arrangement of the lenses are not appropriate, it will be difficult to correct aberrations other than chromatic aberration with a small number of lenses. Therefore, the most suitable lens configuration is as described above. More specifically,
It is desirable that the negative meniscus lens has a surface having a strong curvature toward the image plane side, and the positive lens has a surface having a strong curvature toward the object side.

The second lens component is preferably composed of a total of two lenses, a negative lens and a positive lens, in order from the object side. In order to configure the second lens component with the smallest number of lenses, it is necessary to take the chromatic aberration correction into consideration and make the lens configuration of at least two lenses. At this time, in order to correct the aberration generated in the second lens component as much as possible, it is necessary to have the above-mentioned configuration. More specifically, it is desirable that the negative lens has a surface having a strong refractive power toward the image plane side and the positive lens has a surface having a strong refractive power toward the object side.

Alternatively, it is desirable that the first lens component is composed of a total of three lenses including a negative meniscus lens, a positive lens and a positive meniscus lens in order from the object side. In a high-performance zoom lens with a high zoom ratio, it is necessary to more strictly perform aberration correction on each lens component. This is because if the aberration generated in each lens component is not corrected, the fluctuation of the aberration during zooming becomes large, and the required performance cannot be obtained in the entire focal length range. One way to keep the aberration of each lens component as small as possible is to weaken the refractive power of each lens component. However, in this method, the amount of movement of each lens component during zooming naturally increases and the lens system also increases. The other method is to increase the number of lenses for each lens component. If this method is adopted, the lens system can be made compact and the outer diameter of the lens can be made small, so that there is also an advantage that the cost is reduced rather than the one having a small number of lenses. In particular,
It is best to have a three-sheet structure as described above. 3 like this
The single-lens configuration has a considerable effect of correcting aberrations, and is sufficiently applicable to a 12 × zoom lens.

It is desirable that the second lens component is composed of a total of three lenses including a negative lens, a biconcave lens and a positive lens in order from the object side. In a zoom lens having a high zoom ratio, the aberration variation due to zooming can be considerably reduced by making the second lens component also have the above-described three-lens configuration.

Further, it is desirable that the variable power lens of the present invention satisfies the following conditional expression (7).

0.01 <| t2 | / | t3 | <0.35 (7) where t2 is the total movement amount of the second lens component and t3 is the total movement amount of the third lens component.

Conditional expression (7) defines the ratio of the moving amounts of the second lens component and the third lens component. It is the second lens component that mainly performs zooming, and the third lens component performs auxiliary zooming, which reduces the amount of movement of the second lens component and helps shorten the overall lens length. When the amount of movement of the second lens component exceeds the amount of movement of the third lens component beyond the upper limit of the conditional expression (7), the amount of the third lens component that assists zooming becomes small and practically almost no effect is obtained. There is no. In other words, the only disadvantage remains that many lens components must be moved.

When the amount of movement of the third lens component is increased beyond the lower limit of the conditional expression (7), the third lens component and the fourth lens component are extremely close to each other at the wide-angle end from near the middle, and the fourth lens component
The width of the light beam incident on the lens component becomes large. Therefore, it becomes difficult to correct aberrations in the fourth lens component, and it becomes difficult to realize a bright lens.

Focusing is preferably performed by the fourth lens component. When focusing with the front lens as in the past, the diameter of the front lens becomes very large. In order to prevent this, recently, the inner focus and rear focus, which focus on other than the front lens, have become the mainstream. In the lens type of the present invention, focusing is best performed by the fourth lens component. In addition to the fact that the diameter of the front lens does not increase, the advantage of focusing other than the front lens is
At the wide-angle end, it is possible to focus almost to the lens tip. The inner focus and the rear focus have the inconvenience that the amount of extension of the focusing lens component with respect to an object at the same distance varies depending on the focal length, but the merit is far greater.

Specific numerical examples of the variable power lens according to the present invention will be shown below. Here, in each embodiment, r
i (i = 1,2,3, ...) is the radius of curvature of the i-th surface counted from the object side, and di (i = 1,2,3, ...) is the radius counted from the object side. i-th axial upper surface spacing, ni (i = 1, 2, 3, ...), νi (i =
1, 2, 3 ... Shows the refractive index and the Abbe number for the d-line (λ = 587.6 nm) of the i-th lens counted from the object side. Further, f indicates the focal length of the entire system.

In the examples, the surface with a radius of curvature marked with * indicates that it is a surface formed of an aspherical surface, and is defined by the following expression representing the surface shape of the aspherical surface.

[0050]

[Equation 1]

Here, X: amount of deviation from the reference surface in the optical axis direction, r: paraxial radius of curvature, h: height in the direction perpendicular to the optical axis, An: aspherical coefficient of order n ε: quadric surface parameter Is.

The following examples all have a four-component construction, but between the lens components or on the image side or object side of the entire system,
It is easy to dispose a fixed or movable lens component having a relatively weak refractive power with a simple structure, and this is included in the gist of the present invention.

<Example 1> f = 65.0 to 10.0 to 5.8 Curvature radius Axial upper surface spacing Refractive index (Nd) Abbe number (νd) r1 45.676 d1 1.300 N1 1.83350 ν1 21.00 r2 27.898 d2 4.900 N2 1.69680 ν2 56.47 r3 -1209.614 d3 0.150 r4 23.117 d4 2.400 N3 1.69680 ν3 56.47 r5 34.926 d5 24.467 ~ 8.443 ~ 1.000 r6 75.390 d6 0.800 N4 1.77250 ν4 49.77 r7 6.939 d7 3.700 r8 -2810 9.5 2 r11 61.279 d11 2.000 ~ 18.023 ~ 25.467 r12 ∞ d12 2.500 ~ 3.795 ~ 4.393 r13 * 14.918 d13 3.200 N7 1.58913 ν7 61.11 r14 142.908 d14 7.500 ~ 2.910 ~ 3.958 r15 96.674 1.967 N9 1.82666916. -82.162 d17 0.100 r18 48.748 d18 2.800 N10 1.58913 ν10 61.11 r19 * -19.386 d19 3.000 to 6.294 to 4.649 r20 ∞ d20 4.840 N11 1.51680 ν11 64.20 r21 ∞ [aspherical coefficient] r13 ε = 1.0 A4 = -0.72177 x 10 ^-4 A6 = -0.72868 x 10 ^-7 r19 ε = 1.0 A4 = 0.45621 x 10 ^-4 A6 = 0.65836 x 10 ^-6 A8 = -0.11464 x 10 ^-7 .

<Example 2> f = 65.0 to 10.0 to 5.8 Curvature radius Axial upper surface spacing Refractive index (Nd) Abbe number (νd) r1 44.403 d1 1.300 N1 1.84666 ν1 23.82 r2 25.645 d2 5.900 N2 1.67000 ν2 57.07 r3 -787.042 d3 0.150 r4 21.452 d4 2.100 N3 1.67000 ν3 57.07 r5 32.063 d5 25.341 ~ 8.775 ~ 1.000 r6 37.766 d6 0.800 N4 1.77250 ν4 49.77 r7 6.585 d7 3.900 r8 -283 200.962 r11 60.533 d11 2.000〜18.566〜26.341 r12 ∞ d12 2.500〜3.795〜4.393 r13 * 22.823 d13 3.200 N7 1.58913 ν7 61.11 r14 -53.028 d14 7.500〜2.931〜3.940 r15 79.836 d15 0.900 N8 1.9161616 8.23 r17 -27.783 d17 1.000 r18 82.700 d18 2.400 N10 1.51680 ν10 64.20 r19 -25.998 d19 3.000 ~ 6.274 ~ 4.667 r20 ∞ d20 4.840 N11 1.51680 ν11 64.20 r21 ∞ [aspheric coefficient] r13 ε = 1.0 A4 = -0 .68914 × 10 ^-4 A6 = -0.39999 × 10 ^-7 .

Example 3 f = 65.0 to 10.0 to 5.8 Curvature radius Axial upper surface spacing Refractive index (Nd) Abbe number (νd) r1 37.983 d1 1.300 N1 1.83350 ν1 21.00 r2 24.242 d2 5.500 N2 1.67000 ν2 57.07 r3 -2615.405 d3 0.150 r4 23.712 d4 2.200 N3 1.60311 ν3 60.74 r5 42.796 d5 22.250 to 7.696 to 1.000 r6 106.934 d6 0.800 N4 1.71300 ν4 53.93 r7 6.755 d7 3.700 r8 -26.06 r11 46.901 d11 2.000 ~ 16.554 ~ 23.250 r12 ∞ d12 2.500 ~ 3.795 ~ 4.393 r13 * 14.744 d13 3.200 N7 1.64000 ν7 58.61 r14 280.502 d14 1.000 r15 -20.215 d15 0.917 N8 1.80518 ν8 25.341 r16 * 14.2918. 0.900 N9 1.84666 ν9 23.82 r18 14.176 d18 3.100 N10 1.69680 ν10 56.47 r19 -242.844 d19 0.100 r20 86.229 d20 2.800 N11 1.58913 ν11 61.11 r21 * -18.417 d21 3.000〜6.915〜5.322 r22 ∞d 0 N12 1.51680 ν12 64.20 r23 ∞ [aspherical coefficient] r13 ε = 1.0 A4 = -0.49003 × 10 ^-4 A6 = 0.21064 × 10 ^-6 r21 ε = 1.0 A4 = 0.79885 × 10 ^-4 A6 = 0.11328 × 10 ^-5 A8 = -0.15926 × 10 ^-7 .

<Example 4> f = 65.0 to 10.0 to 5.8 Radius of curvature Axial upper surface distance Refractive index (Nd) Abbe number (νd) r1 37.983 d1 1.300 N1 1.83350 ν1 21.00 r2 24.242 d2 5.500 N2 1.67000 ν2 57.07 r3 -2957.967 d3 0.150 r4 23.706 d4 2.200 N3 1.60311 ν3 60.74 r5 42.873 d5 22.222 to 7.693 to 1.000 r6 107.044 d6 0.800 N4 1.71300 ν4 53.93 r7 6.755 d7 3.700 r8 -2 370 r11 46.912 d11 2.000 ~ 16.529 ~ 23.222 r12 ∞ d12 2.500 ~ 3.795 ~ 4.393 r13 * 14.676 d13 3.200 N7 1.62041 ν7 60.29 r14 353.499 d14 1.000 r15 28.077 d15 0.917 1.989017. 1.84666 ν9 23.82 r18 14.186 d18 3.100 N10 1.69680 ν10 56.47 r19 -236.624 d19 0.100 r20 86.147 d20 2.800 N11 1.58913 ν11 61.11 r21 * -18.476 d21 3.000 ~ 6.897 ~ 5.317 r22 ∞ d22 4.840 12 1.51680 ν12 64.20 r23 ∞ [aspherical coefficients] r13 ε = 1.0 A4 = -0.70889 × 10 -4 A6 = -0.50264 × 10 -7 r21 ε = 1.0 A4 = 0.62913 × 10 -4 A6 = 0.88209 × 10 -6 A8 = -0.15916 x 10 ^-7 .

<Example 5> f = 37.9 to 18.0 to 6.7 Curvature radius Axial upper surface distance Refractive index (Nd) Abbe number (νd) r1 20.340 d1 1.100 N1 1.83350 ν1 21.00 r2 15.420 d2 1.200 r3 17.018 d3 4.650 N2 1.69680 ν2 56.47 r4 500.706 d4 19.417-12.776-1.150 r5 -40.819 d5 0.600 N3 1.75450 ν3 51.57 r6 7.006 d6 2.400 r7 * 19.466 d7 2.300 N4 1.84506 ν4 23.66 r8 39.586 d8 1.650 〜8.291 〜19.917 9.79 r9 39100586 ∞ 2.700 N5 1.76683 r11 32.597 d11 4.500 to 1.803 to 2.349 r12 44.528 d12 1.300 N6 1.80518 ν5 25.43 r13 8.405 d13 3.600 N7 1.76683 r14 * -22.463 d14 2.211 to 4.327 to 2.762 r15 ∞ d15 4.840 ν6 1.520 840 N6 1.58 r7 ε = 1.0 A4 = 0.20592 × 10 ^-3 A6 = -0.48934 × 10 ^-6 A8 = 0.21295 × 10 ^-6 A10 = -0.44687 × 10 ^-8 r10 ε = 1.0 A4 = -0.44636 × 10 ^-4 A6 = -0.80443 × 10 ^-6 A8 = 0.40863 × 10 ^-7 A10 = -0.72788 × 10 ^-9 r14 ε = 1.0 A4 = 0.11166 x 10 ^-3 A6 = -0.45960 x 10 ^-5 A8 = 0.25463 x 10 ^-6 A10 = -0.51255 x 10 ^-8 .

<Example 6> f = 70.0 to 36.0 to 6.2 Radius of curvature Axial upper surface spacing Refractive index (Nd) Abbe number (νd) r1 30.682 d1 1.100 N1 1.83350 ν1 21.00 r2 20.799 d2 4.200 N2 1.58913 ν2 61.11 r3 343.739 d3 0.100 r4 20.902 d4 2.700 N3 1.58913 ν3 61.11 r5 46.220 d5 19.776 to 16.288 to 1.100 r6 44.854 d6 1.100 N4 1.69680 ν4 56.47 r7 5.850 d7 3.000 yr 8 20.456 d11 2.000 ~ 5.488 ~ 20.676 r12 ∞ d12 1.700 ~ 2.746 ~ 7.303 r13 16.429 d13 3.000 N7 1.58913 ν7 61.11 r14 * 52.853 d14 13.000 ~ 4.503 ~ 0.782 r15 29.905 d15 16.17 d17 4.617 d17 4.171617 16.665 d16 4.617 rd16 4.617 rd16 4.17 ν9 61.11 r18 * -14.972 d18 1.500〜8.950〜8.116 r19 ∞ d19 4.840 N10 1.51680 ν10 64.20 r20 ∞ [aspherical coefficient] r14 ε = 0.66708 × 10 A4 = -0.14598 × 10 ^-3 A6 = 0.22461 × 10 ^-5 A8 = 0.34191 × 10 ^-7 A10 = -0.47697 × 10 ^-9 r18 ε = -0.30872 A4 = 0.47860 × 10 ^-4 A6 = 0.14001 × 10 ^-5 A8 = 0.56602 × 10 ^-7 A10 = -0.13320 × 10 ^-8 .

<Example 7> f = 70.0 to 36.0 to 6.2 Radius of curvature Axial upper surface spacing Refractive index (Nd) Abbe number (νd) r1 35.679 d1 1.100 N1 1.83350 ν1 21.00 r2 23.809 d2 4.200 N2 1.58913 ν2 61.11 r3 -291.279 d3 0.100 r4 22.567 d4 2.700 N3 1.58913 ν3 61.11 r5 49.220 d5 20.393 to 16.605 to 1.100 r6 97.975 d6 0.800 N4 1.69680 ν4 56.47 r7 5.961 rd 400.000 r9 0.38 r6 0.300 r6 0.300 r5 .47 r11 21.368 d11 2.000 ~ 5.788 ~ 21.293 r12 ∞ d12 1.700 ~ 2.647 ~ 6.523 r13 14.036 d13 2.400 N7 1.58913 ν7 61.11 r14 -47.783 d14 0.800 r15 -30.522 d15 0.617 rd17 23.17 rd17 23.50 rd17. 0.750 N9 1.83350 ν9 21.00 r18 17.108 d18 0.400 r19 12.830 d19 4.600 N10 1.58913 ν10 61.11 r20 * -27.086 d20 1.500 to 9.168 to 7.227 r21 ∞ d21 4.840 N11 1.51680 ν11 64.20 r22 ∞ [aspherical coefficient] ] R16 ε = 1.0 r20 ε = −0.91873 × 10 A4 = 0.11455 × 10 ⁻³ A6 = 0.11126 × 10 ⁻⁵ A8 = 0.12889 × 10 ⁻⁷ A10 = −0.67695 × 10 ⁻⁹ .

<Example 8> f = 66.0 to 35.0 to 5.7 Radius of curvature Axial upper surface spacing Refractive index (Nd) Abbe number (νd) r1 41.873 d1 1.100 N1 1.84666 ν1 23.82 r2 23.085 d2 5.700 N2 1.51680 ν2 64.20 r3 -86.708 d3 0.100 r4 19.106 d4 2.700 N3 1.51680 ν3 64.20 r5 78.181 d5 18.458〜14.850〜0.570 r6 -217.994 d6 0.650 N4 1.77250 ν4 49.77 r7 8.760 d7 3.300 r8 -10.58 d10 2.000 ~ 5.608 ~ 19.888 r11 ∞ d11 1.500 ~ 1.861 ~ 3.289 r12 13.840 d12 2.800 N7 1.59844 r13 * -346.342 d13 9.453 ~ 3.853 ~ 10.186 r14 18.017 d14 0.650 N8 1.84666 ν7 23.82 r15 8.630 d16 -26.44 1.54 ~ 9.239 ~ 1.478 r17 ∞ d17 4.840 N10 1.51680 ν8 64.20 r18 ∞ [aspheric coefficient] r13 ε = 1.0 A4 = 0.82831 × 10 ^-4 A6 = -0.49893 × 10 ^-7 A8 = 0.11039 × 10 ^-8 r16 ε = 1.0 A4 = 0.54030 x 10 ^-4 A6 = 0.16398 x 10 ^-6 A8 = -0.31394 x 10 ^-8 .

<Example 9> f = 66.0 to 15.0 to 5.7 Radius of curvature Axial upper surface spacing Refractive index (Nd) Abbe number (νd) r1 36.192 d1 1.100 N1 1.84666 ν1 23.82 r2 22.258 d2 6.000 N2 1.51680 ν2 64.20 r3 -80.549 d3 0.100 r4 19.560 d4 2.500 N3 1.51680 ν3 64.20 r5 47.684 d5 18.800 ~ 9.673 ~ 0.572 r6 24.332 d6 0.700 N4 1.77250 ν4 49.77 r7 8.591 d7 3.200 r8 -11.40 740.6450.9450.974506. 〜 10.827〜19.928 r11 ∞ d11 2.000〜2.913〜3.823 r12 11.558 d12 3.300 N7 1.58913 ν7 61.11 r13 -20.417 d13 1.200 r14 -11.008 d14 0.800 N8 1.58913 ν8 61.11 r15 * -68.19 9.8193.923 ν9 21.00 r17 9.750 d17 0.500 r18 10.996 d18 3.800 N10 1.58913 ν10 61.11 r19 * -13.722 d19 1.000 ~ 6.669 ~ 3.759 r20 ∞ d20 4.840 N11 1.51680 ν11 64.20 r21 ∞ [aspherical coefficient] r15 A = 0.26051 ^{-0.10940 × 10 -4 A6 = 0.32705 ×} 10 -5 A8 = -0.19181 × 10 -6 A10 = 0.19709 × 10 -8 r19 ε = -0.35363 × 10 A4 = -0.37759 × 10 -4 A6 = -0.19674 × 10 - ⁵ A8 = 0.11961 x 10 ^-6 A10 = -0.12711 x 10 ^-8 .

The value of each conditional expression in each example is as follows.

[0063]

As described above, according to the present invention,
It is possible to provide a highly variable and bright variable power lens having a variable power ratio of about 12 times and an F number of about 1.8, which is compact and has a small number of constituent elements, and which is sufficiently satisfactory in terms of performance.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a lens corresponding to Example 1 of the present invention.

FIG. 2 is a configuration diagram of a lens corresponding to Example 2 of the present invention.

FIG. 3 is a configuration diagram of a lens corresponding to Example 3 of the present invention.

FIG. 4 is a configuration diagram of a lens corresponding to Example 4 of the present invention.

FIG. 5 is a configuration diagram of a lens corresponding to Example 5 of the present invention.

FIG. 6 is a configuration diagram of a lens corresponding to Example 6 of the present invention.

FIG. 7 is a configuration diagram of a lens corresponding to Example 7 of the present invention.

FIG. 8 is a configuration diagram of a lens corresponding to Example 8 of the present invention.

FIG. 9 is a configuration diagram of a lens corresponding to Example 9 of the present invention.

FIG. 10 is an aberration diagram of a lens corresponding to Example 1 of the present invention.

FIG. 11 is an aberration diagram of a lens corresponding to Example 2 of the present invention.

FIG. 12 is an aberration diagram of a lens corresponding to Example 3 of the present invention.

FIG. 13 is an aberration diagram of a lens corresponding to Example 4 of the present invention.

FIG. 14 is an aberration diagram of a lens corresponding to Example 5 of the present invention.

FIG. 15 is an aberration diagram of a lens corresponding to Example 6 of the present invention.

FIG. 16 is an aberration diagram of a lens corresponding to Example 7 of the present invention.

FIG. 17 is an aberration diagram of a lens corresponding to Example 8 of the present invention.

FIG. 18 is an aberration diagram of a lens corresponding to Example 9 of the present invention.

Claims (2)

[Claims] 1. A first lens component having a positive refractive power, a second lens component having a negative refractive power, and a third lens component having a positive refractive power in order from the object side.
A variable power lens having a lens component and a fourth lens component having a positive refractive power and satisfying the following conditional expression: 0.10 ≤ fs ・ φ1 ≤ 0.25 0.45 <fs ・ | φ2 | <1.25 where fs is the focal length of the entire system at the wide-angle end, φ1 is the refractive power of the first lens component, and φ2 is the refractive power of the second lens component. 2. The second lens component is movable back and forth on the optical axis for zooming, and the third lens component is also on the optical axis in the opposite direction to the second lens component for zooming. Is movable back and forth, and the fourth lens component is movable back and forth in a U-turn-shaped locus along the optical axis in order to make the position of the image plane constant during zooming. The variable power lens according to item 1.