KR101436328B1 - Telesphoto zoon lens - Google Patents

Abstract

A telephoto zoom lens is disclosed. The disclosed telephoto zoom lens includes a front lens group which is arranged in order from the object side and which has a positive refractive power and is fixed at the time of focusing according to the object distance and a first lens group which has positive refractive power and which is moved at the time of focusing according to the object distance. ; A second lens group having a negative refracting power and being moved during magnification; A third lens group having a positive refracting power and being moved during magnification; And a fourth lens group including a group of camera shake correction lenses that correct the image blur caused by the camera shake by moving in a direction perpendicular to the optical axis.

Description

Telesphoto zoon lens [0002]

The disclosed zoom lens relates to a telephoto zoom lens capable of correcting the shaking motion.

2. Description of the Related Art Recently, digital cameras and video cameras having solid-state image pickup devices such as a CCD (Charge Coupled Device) and a CMOS (Complementary Metal-Oxide Semiconductor) have been widely used. Particularly, there is a demand for a mega pixel camera module, and in the entry-level digital camera, more than 5 million pixels and a camera having a high image quality are emerging. 2. Description of the Related Art An imaging optical device such as a digital camera or a mobile phone camera using an imaging device such as a CCD or CMOS is required to be downsized, lightweight, and low in cost.

In addition, there is a growing demand for high-aspect ratio as well as miniaturization and weight reduction. A telephoto zoom lens having a high-aspect ratio has an advantage that a subject at a long distance can be photographed in a large size. On the other hand, a telephoto zoom lens has a large focal length, The quality of the picture may be deteriorated.

Accordingly, in recent years, a zoom lens system of a telephoto type, which is released in the market, is required to have a function of correcting a change in angle of view caused by an unintentional hand movement. Various design schemes have been proposed for this purpose. In particular, it is necessary to design an optical system capable of reducing the movement amount of the lens group for the correction of the shaking motion and increasing the image stabilization effect.

According to the above-described necessity, embodiments of the present invention provide a telephoto zoom lens capable of effectively performing shaking correction.

The telephoto zoom lens according to an embodiment of the present invention is arranged in order from the object side. The telephoto zoom lens has a positive refracting power and is fixed at the time of focusing according to the object distance, and has a positive refracting power. A first lens group composed of a rear group; A second lens group having a negative refracting power and being moved during magnification; A third lens group having a positive refracting power and being moved during magnification; And a fourth lens group including a group of camera shake correction lenses for correcting image blur caused by camera shake by moving in a direction perpendicular to the optical axis, and the following conditional expression is satisfied.

<Conditional expression>

0.35 < _f4C / fT < 0.46

Here, f _4C , f _T Are the focal length of the camera shake correction lens group and the total focal length at the telephoto end, respectively.

The telephoto zoom lens according to an embodiment of the present invention is arranged in order from the object side. The telephoto zoom lens has a positive refractive power and is fixed when focusing according to the object distance, and has a positive refractive power. A first lens group composed of a rear lens group to be moved; A second lens group having a negative refracting power and being moved during magnification; A third lens group having a positive refracting power and being moved during magnification; And a fourth lens group including a group of camera shake correction lenses for correcting image blur caused by camera shake by moving in a direction perpendicular to the optical axis, and the following conditional expression is satisfied.

<Conditional expression>

1.0 < f _4C / f _W < 1.3

Here, f _4C , f _W Are the focal lengths of the camera shake correction lens group and the total focal length at the wide angle end, respectively.

In addition, the telephoto zoom lens according to an embodiment of the present invention is arranged in order from the object side. The telephoto zoom lens has a positive refractive power and is fixed when focusing according to the object distance, and has a positive refractive power. A first lens group composed of a rear lens group; A second lens group having a negative refracting power and being moved during magnification; A third lens group having a positive refracting power and being moved during magnification; And a fourth lens group including a group of camera shake correction lenses for correcting image blur caused by camera shake by moving in a direction perpendicular to the optical axis, and the following conditional expression is satisfied.

<Conditional expression>

0.25 < _f4C / L < 0.35

Here, f _4C and L are the focal length of the camera shake correction lens group and the distance from the apex of the first object side of the first lens group to the image surface.

Embodiments of the present invention can further satisfy the following conditional expression.

<Conditional expression>

20 < v _2- v ₁ < 35

Here, v ₁ and v ₂ are the Abbe numbers of the first and second lenses of the first lens group, respectively.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following drawings, like reference numerals refer to like elements, and the size of each element in the drawings may be exaggerated for clarity and convenience of explanation.

FIGS. 1, 6, 11, 16, and 21 are views showing the optical arrangement of the telephoto zoom lens according to the first to fifth embodiments of the present invention at a wide angle end, a middle end, and a telephoto end, respectively.

The telephoto zoom lens according to the embodiments of the present invention includes, in order from the object OBJ side, a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, The third lens group G3 includes a fourth lens group G4 having positive refractive power.

The first lens group G1 is a focator, and functions to position an infinite object at a finite distance. In the zoom lens of the general PNPP type, focusing is performed in a lens group which performs a function of a compensator. In contrast, in the embodiments of the present invention, the first lens group G1, which is a planar lens, . At this time, if the entire first lens group G1 is focused, the amount of movement during focusing according to the object distance increases, which increases the effective diameter of the first lens group G1. Accordingly, the first lens group G1 is divided into a front group G1-a and a rear group G1-b, and the front group G1-a of the first lens group G1 is fixed at the time of focusing, (G1-b) of the first lens group G1 are moved upon focusing. The entire first lens group G1 is fixed at the time of changing.

The second lens group G2 is a lens group that performs a function of a variator and is moved when magnified.

The third lens group G3 functions as a compensator for preventing top surface movement by the variable magnifier, and is moved in magnification.

The fourth lens group G4 is a relay lens group, and in the embodiments of the present invention, includes the camera shake correction lens group G4-1. In the case of a zoom lens of the telephoto type, the camera shake correction function is generally required because the focal length is long and the angle of view change due to the camera shake is large. The camera shake correction includes a method of moving the CCD perpendicularly to the optical axis and a method of moving the specific lens group in a direction perpendicular to the optical axis. In the embodiments of the present invention, a configuration in which a specific lens group is moved in a direction perpendicular to the optical axis . The hand shake correction lens group G4-1 is disposed immediately behind the third lens group G3. This arrangement forms an almost infinite optical system from the first lens group G1 to the third lens group G3, and accordingly, the lens group positioned immediately behind the third lens group G3 is a center of focus decenter), it is selected because it is suitable for hand-shake correction.

In the embodiments of the present invention, the entire optical system is designed so that the focal length of the camera shake correction lens group G4-1 is shorter than that in the ordinary case, so that the amount of movement for correction of the shaking motion is minimized.

Embodiments of the present invention satisfy the following conditional expression.

0.35 < _f4C / fT < 0.46

Here, f _4C , f _T Are the focal length of the camera shake correction lens group G4-1 and the total focal length at the telephoto end, respectively.

The above equation is a conditional expression defining the focal length for the camera shake correction lens group G4-1. The correction amount for the angle of view change caused by the shaking motion (hereinafter referred to as the shaking motion correction amount) becomes shorter as the focal length of the shaking motion correction lens group G4-1 becomes shorter Lt; / RTI &gt; However, if the focal length of the camera shake correction lens group G4-1 is too short, the curvature of each lens constituting the lens group becomes small, so that the performance variation due to the manufacturing error is large, which causes a manufacturing problem. On the other hand, since the correction of the shaking motion is influenced by the focal length of the telephoto end, the optical design of the camera shake correction lens group G4-1 is performed considering the focal length of the telephoto end. Therefore, when the ratio of the focal length of the camera shake correction lens group G4-1 to the focal length of the telephoto end satisfies the range of the conditional expression, stable optical performance is obtained even when the shake correction lens group G4-1 is changed &Lt; / RTI &gt;

Embodiments of the present invention satisfy the following conditional expression.

1.0 < f _4C / f _W < 1.3

Here, f _4C , f _W Are the focal lengths of the camera shake correction lens group G4-1 and the total focal lengths at the wide angle end, respectively.

Is a condition for the focal length of the esophageal image stabilization lens group G4-1. When the focal length of the wide angle end is relatively large as compared with the general optical system as in the embodiment of the present invention, the correction amount of the camera shake is also increased at the wide angle end. Therefore, apart from Equation (1), the focal length of the camera shake correction lens group G4-1 and the focal length of the wide angle end must be simultaneously considered.

Embodiments of the present invention satisfy the following conditional expression.

0.25 < _f4C / L < 0.35

Here, f _4C, L is the respective distance from the vertex of the object side of the first surface of the camera-shake correction lens group (G4-1) and the focal length of the first lens group (G1) to the upper surface.

The esophagus is also a condition for the focal length of the camera shake correction lens group G4-1. However, unlike Equations (1) and (2), it means that the total length of the optical system is included, and that the optical length should not be too long, and that the optical design should be such that the focal length of the camera shake correction lens group G4-1 is short.

The above three equations are obtained by limiting the focal length of the camera shake correction lens group G4-1 by using the focal length of the wide angle end, the focal length of the telephoto end, and the ratio of the optical system total length, It is proposed to minimize the movement amount of the correction lens group (G4-1) and to minimize the performance change due to the movement amount.

Referring to FIG. 1, the lens configuration will be described in more detail.

The first lens group G1 includes a front group G1-a having a positive refractive power and a rear group G1-b having a positive refractive power and the front group G1-a includes first, Lenses 11-1, 12-1, and 13-1, and the rear group may include fourth and fifth lenses 14-1 and 15-1. The first lens 11-1 and the second lens 12-1 may be composed of a cemented lens.

The first lens group G1 is constituted by an optical system that corrects chromatic aberration well while using a low dispersion material having Abbe number greater than 80 as much as possible. In the large-diameter telephoto zoom lens according to the embodiments of the present invention, the first lens group G1 has a large diameter and a high material cost. For example, when a low dispersion material is used as the first lens group G1 In addition, when the lens is not used on the lens surface constituting the cemented lens, the price increase factor due to defects in processing not only the material price but also the large diameter cemented lens is minimized. In the embodiments of the present invention, for example, only the third lens 13-1, which is not a cemented lens, uses a low dispersion material having Abbe's number of more than 80. Particularly, in the second lens of the first lens group G1 Abe Sue is using a small affordable material. Embodiments of the present invention can satisfy the following expressions.

20 < v _2- v ₁ < 35

Here, ν _1, ν ₂ is the Abbe number of each of the first and second lens of the first lens group (G1).

The above equation is a condition for removing the chromatic aberration occurring in the front group G1-a of the first lens group G1 and is a range of the difference between the Abbe number of the first lens of the first lens group G1 and the Abbe number of the second lens G1 And it is proposed to reduce the cost of the material itself and the factor of raising the price due to defects in the processing of the first lens group G1. If this value is smaller, the optical performance is lowered due to limitation of the intricacy and lateral chromatic aberration generated in the front group G1-a of the first lens group G1, and if it is too large, There is a difficulty in poetry.

The second lens group G2 has a negative refracting power and may be composed of four lenses. For example, the second lens group G2 includes a sixth lens 21-1 as a negative lens, a seventh lens 22-1 as a negative lens, an eighth lens 23-1 as a positive lens, And a seventh lens 22-1 and an eighth lens 23-1 may be bonded to each other.

The third lens group G3 has a positive refractive power and may be composed of, for example, the tenth to twelfth lenses 31-1, 32-1 and 33-1.

The fourth lens group G4 includes the camera shake correction lens group G4-1. In the camera shake correction lens group G4-1, for example, a thirteenth lens 41-1 as a meniscus lens and a fourteenth lens 42-1 as a biconvex lens are bonded to each other, 15 lens 43-1. The fourth lens group G4 may further include lenses further configured in addition to the hand shake correction lens group G4-1.

Embodiments of the present invention maintain a small F number even at the telephoto end so as to provide a bright telephoto zoom lens in which the F number is fixed during variable magnification. For this purpose, a lens group having a positive refractive power is constituted in front of the diaphragm.

Hereinafter, specific lens data of various embodiments of the wide-angle zoom optical system according to the present invention will be described.

In the following, f denotes the combined focal length of the entire zooming optical system, F-number denotes the F number, and 2ω denotes the angle of view. In addition, STOP means aperture. Radius is the radius of curvature, Thickness is the lens spacing or thickness, and Semi-aperture is half of the aperture, and n _d and v _d are the refractive index and the Abbe number, respectively. D2, D3, D4, D5, D6, and D7 in the wide angle end (WIDE), middle end (MIDDLE), and telephoto end (TELE). In each embodiment, the reference numerals of the respective components are shown in association with the embodiment numbers.

&Lt; Embodiment 1 >

FIG. 1 illustrates a telephoto zoom lens according to a first embodiment. The first lens group G1 includes first through third lenses 11-1, 12-1, 12-2, -1) and the fifth and sixth lenses 14-1 and 15-1 which are the rear group G1-b and the second lens group G2 is composed of the sixth, seventh, eighth, Lenses 21-1 and 22-1 and lenses 23-1 and 24-1 and the third lens group G3 is composed of lenses 10-1 and 12-2, The fourth lens group G4 is composed of the first lens group G1-1, the third lens group G2-1, the third lens group G2-1, the fourth lens group G2-1, And the 16th to 20th lenses 44-1, 45-1, 46-1, 47-1, and 48-1. An infrared filter 50 is provided on the upper side of the fourth lens group G4.

 The following is lens data of the first embodiment.

f = 72.1 to 203.7 mm, F-number = 2.9 to 2.9, 2? = 34.68 to 11.75 Surface # Radius Thickness n _d v _d Semi-Aperture OBJECT ∞ S1 112.592 2.20 1.80610 40.7 36.5 S2 68.689 9.00 1.48749 70.4 S3 150.169 0.15 S4 77.883 8.90 1.49700 81.6 S5 358.202 D1 S6 78.399 1.80 1.84666 23.8 S7 58.944 1.412 S8 68.635 8.70 1.69680 55.5 S9 595.668 D2 S10 -358.256 1.90 1.80610 33.3 S11 35.947 5.885 16.7 S12 -87.469 1.80 1.48749 70.4 S13 38.987 7.00 1.92286 20.9 S14 -607.985 2.168 S15 -70.097 1.90 1.74950 35 S16 296.53 D3 S17 -746.128 3.90 1.49700 81.6 S18 -82.386 0.15 S19 101.392 8.00 1.49700 81.6 S20 -50.586 2.00 1.74330 49.2 S21 -168.457 D4 STOP ∞ 1.00 19.1 S23 181.070 2.00 1.80518 25.5 S24 47.162 8.00 1.69680 55.5 S25 -143.139 0.15 S26 78.008 4.00 1.69680 55.5 S27 226.594 6.589 S28 -599.264 3.80 1.84666 23.8 S29 -61.576 1.50 1.74330 49.2 S30 120.968 20.183 S31 102.459 1.50 1.62041 60.3 S32 52.59 2.735 S33 174.376 7.50 1.74400 44.9 S34 -40.663 2.00 1.84666 23.8 S35 -117.638 D5 16.5 S36 ∞ 3.00 1.51872 64.2 S37 ∞ G IMAGE ∞

Wide Middle Tele D1 15.6502 15.6502 15.6502 D2 2.5200 19.0503 35.5807 D3 34.6038 26.2024 1.9975 D4 10.4114 2.2825 9.957 D5 65.8937 65.8937 65.8937 D6 1.1722 1.0183 0.9632

FIGS. 2A to 2C show longitudinal and lateral spherical aberration, surface curvature, and distortion aberration at the wide angle end, the simple end, and the telephoto end, respectively, of the zoom lens according to the first embodiment of the present invention. The longitudinal spherical aberration is shown for light with wavelengths of 656.2725 (nm), 587.5618 (nm), and 486.1327 (nm), respectively. The surface curvature is represented by tangential field curvature (T) for light with a wavelength of 587.5618 ) As a dotted line and a sagittal field curvature as a solid line. FIG. 3A shows a ray fan when the camera shake correction lens group G4-1 is moved in the upward direction perpendicular to the optical axis by 0.8 mm at the wide angle end, FIG. 3B shows the ray fan when the shake correction lens group G4-1 FIG. 3C shows a ray fan when the camera shake correcting lens group G4-1 moves in the downward direction perpendicular to the optical axis by 0.8 mm at the wide angle end. Figs. 4A to 4C show the ray fan at the intermediate stage, and Figs. 5A to 5C show the ray fan at the telephoto end.

&Lt; Embodiment 2 >

6 shows a telephoto zoom lens according to the second embodiment. The first lens group G1 includes first through third lenses 11-2, 12-2, And the fifth and sixth lenses 14-2 and 15-2 which are the rear group G1-b and the second lens group G2 is composed of the sixth, seventh, eighth, Lenses 21-2 and 22-2 and lenses 23-2 and 24-2 and the third lens group G3 is composed of lenses 10 and 11 and lenses 32-2 and 32-2, The fourth lens group G4 is composed of the first lens group G2-1 and the second lens group G2-1, And the 16th to 21th lenses 44-2, 45-2, 46-2, 47-2, 48-2, and 49-2. An infrared filter 50 is provided on the upper side of the fourth lens group G4.

 The following is lens data of the second embodiment.

f = 72.1 to 203.7 mm, F-number = 2.9 to 2.9, 2? = 34.73 to 11.78 Surface # Radius Thickness n _d v _d Semi-Aperture OBJECT ∞ S1 117.561 2.30 1.80610 40.7 36.5 S2 63.402 9.41 1.51680 64.2 S3 134.361 0.15 S4 73.090 10.00 1.49700 81.6 S5 477.82 D1 S6 75.905 1.88 1.78472 25.7 S7 55.791 1.491 S8 63.779 10.50 1.69680 55.5 S9 546.954 D2 S10 -262.93 1.99 1.83400 37.3 S11 36.340 5.958 17.47 S12 -102.382 1.88 1.48749 70.4 S13 39.625 7.00 1.92286 20.9 S14 441.714 2.425 S15 -82.457 1.99 1.88300 40.8 S16 -1301.947 D3 S17 ∞ 4.08 1.49700 81.6 S18 -85.979 0.15 S19 83.983 8.37 1.49700 81.6 S20 -52.705 2.09 1.80610 40.7 S21 -127.242 D4 STOP ∞ 2.00 18.7 S23 269.637 2.09 1.84666 23.8 S24 47.050 8.50 1.69680 55.5 S25 -107.557 0.15 S26 55.071 3.66 1.92286 20.9 S27 77.363 8.00 S28 -142.978 3.97 1.92286 20.9 S29 -45.282 1.57 1.72342 38 S30 160.442 12.786 S31 ∞ 1.57 1.49700 81.6 S32 59.956 3.481 S33 259.791 4.18 1.48749 70.4 S34 -144.946 0.15 S35 192.531 7.30 1.72342 38 S36 -39.255 2.09 1.92286 20.9 S37 -127.556 D5 16.5 S38 ∞ 3 1.51680 64.2 S39 ∞ D6 IMAGE ∞

Wide Middle Tele D1 13.4008 13.4008 13.4008 D2 2.3700 17.9635 33.5572 D3 33.4717 25.3456 1.5571 D4 9.7189 2.2515 10.4464 D5 64.7776 64.7776 64.7776 D6 1.1590 1.0154 0.8960

FIGS. 7A to 7C show longitudinal spherical aberration, surface curvature, and distortion aberration at the wide angle end, the middle end, and the telephoto end, respectively, of the zoom lens according to the second embodiment of the present invention. The longitudinal spherical aberration is shown for light with wavelengths of 656.2725 (nm), 587.5618 (nm), and 486.1327 (nm), respectively. The surface curvature is represented by tangential field curvature (T) for light with a wavelength of 587.5618 ) As a dotted line and a sagittal field curvature as a solid line. 8A shows a ray fan when the camera shake correction lens group G4-1 is moved in the upward direction perpendicular to the optical axis by 0.8 mm at the wide angle end, and FIG. 8B shows the ray fan when the camera shake correction lens group G4-1 FIG. 8C shows a ray fan when the camera shake correction lens group G4-1 is moved by 0.8 mm in the downward direction perpendicular to the optical axis at the wide angle end. FIG. Figs. 9A to 9C show the ray fan at the intermediate stage, and Figs. 10A to 10C show the ray fan at the telephoto end.

&Lt; Third Embodiment >

11 shows a telephoto zoom lens according to the third embodiment. The first lens group G1 includes first through third lenses 11-3, 12-3, And the fifth and sixth lenses 14-3 and 15-3 as the rear group G1-b and the second lens group G2 is composed of the sixth, seventh, eighth, Lenses 21-3, 22-3, 23-3, and 24-3, and the third lens group G3 is composed of the tenth, eleventh, and twelfth lenses 31-3, The fourth lens group G4 is composed of the third lens group G3-1, the third lens group G3 is the third lens group G3-1, the fourth lens group G4 is the third lens group G3-1, The 16th to 21st lenses 44-3, 45-3, 46-3, 47-3, 48-3, and 49-3. An infrared filter 50 is provided on the upper side of the fourth lens group G4.

 The following is lens data of the third embodiment.

f = 66.9 to 194.0 mm, F-number = 2.85 to 2.90, 2? = 37.22 to 12.37 Surface # Radius Thickness n _d v _d Semi-Aperture OBJECT ∞ S1 254.707 2.20 1.83400 37.3 36.5 S2 107.756 9.00 1.48749 70.4 S3 1313.637 0.15 S4 79.816 8.90 1.49700 81.6 S5 278.169 D1 S6 82.02 1.80 1.84666 23.8 S7 56.175 1.011 S8 62.006 9.00 1.80420 46.5 S9 394.779 D2 S10 -946.157 1.90 1.90366 31.3 S11 35.708 5.982 16.7 S12 -80.222 1.80 1.48749 70.4 S13 39.150 7.00 1.92286 20.9 S14 -351.341 1.988 S15 -66.238 1.90 1.88300 40.8 S16 479.528 D3 S17 -788.337 3.90 1.49700 81.6 S18 -80.676 0.15 S19 108.034 8.00 1.49700 81.6 S20 -46.970 2.00 1.74100 52.6 S21 -122.675 D4 STOP ∞ 1.70 18.75 S23 301.282 2.00 1.80518 25.5 S24 47.567 8.00 1.69680 55.5 S25 -109.842 0.15 S26 69.845 3.50 1.88300 40.8 S27 133.965 9.223 S28 -200.232 3.80 1.84666 23.8 S29 -49.990 1.50 1.74100 52.6 S30 121.975 15.261 S31 162.265 1.50 1.74100 52.6 S32 71.720 4.026 S33 ∞ 4.00 1.49700 81.6 S34 -78.878 0.15 S35 159.396 6.50 1.74100 52.6 S36 -63.512 2.00 1.84666 23.8 S37 -418.031 D5 16.5 S38 ∞ 3.00 1.51680 64.2 S39 ∞ D6 IMAGE ∞

Wide Middle Tele D1 12.5082 12.5082 12.5082 D2 2.0000 18.4365 34.873 D3 30.1198 23.0015 2.0052 D4 12.7221 3.4039 7.9637 D5 69.5589 69.5589 69.5589 D6 1.1732 1.0160 0.9621

FIGS. 12A to 12C show longitudinal spherical aberration, field curvature, and distortion aberration at the wide angle end, the middle end, and the telephoto end, respectively, of the zoom lens according to the third embodiment of the present invention. The longitudinal spherical aberration is shown for light with wavelengths of 656.2725 (nm), 587.5618 (nm), and 486.1327 (nm), respectively. The surface curvature is represented by tangential field curvature (T) for light with a wavelength of 587.5618 ) As a dotted line and a sagittal field curvature as a solid line. 13A shows a ray fan when the camera shake correcting lens group G4-1 is moved in the upward direction perpendicular to the optical axis by 0.8 mm at the wide angle end, and FIG. 13B shows the ray fan when the shake blur correcting lens group G4-1 FIG. 13C shows the ray fan when the camera shake correction lens group G4-1 moves in the downward direction perpendicular to the optical axis by 0.8 mm at the wide angle end. Figs. 14A to 14C show the ray fan at the intermediate stage, and Figs. 15A to 15C show the ray fan at the telephoto end.

<Fourth Embodiment>

FIG. 16 illustrates a telephoto zoom lens according to a fourth embodiment. The first lens group G1 includes first through third lenses 11-4, 12-4, And the fifth and sixth lenses 14-4 and 15-4 which are the rear group G1-b and the second lens group G2 is composed of the sixth, seventh, eighth, Lenses 21-4, 22-4, 23-4, and 24-4, and the third lens group G3 is composed of tenth, eleventh, and twelfth lenses 31-4, The fourth lens group G4 is composed of the first lens group G4-1, the third lens group G4-1, the fourth lens group G4-1, the fourth lens group G4-1, the fourth lens group G4-1, And the 16th to 21th lenses 44-4, 45-4, 46-4, 47-4, 48-4, and 49-4. An infrared filter 50 is provided on the upper side of the fourth lens group G4.

 The following is lens data of the fourth embodiment.

f = 67.0 to 194.0 mm, F-number = 2.9 to 2.9, 2ω = 37.20 DEG to 12.39 DEG Surface # Radius Thickness n _d v _d Semi-Aperture OBJECT ∞ S1 162.964 2.20 1.834 37.3 36.5 S2 89.313 9.00 1.48749 70.4 S3 351.989 0.15 S4 80.254 8.90 1.497 81.6 S5 291.370 D1 S6 85.887 1.80 1.84666 23.8 S7 58.56 1.047 S8 65.325 9.00 1.8042 46.5 S9 423.515 D2 S10 -1250.485 1.90 1.90366 31.3 S11 35.813 6.035 16.7 S12 -77.844 1.80 1.48749 70.4 S13 39.700 7.00 1.92286 20.9 S14 -325.463 2.061 S15 -62.744 1.90 1.883 40.8 S16 983.542 D3 S17 -361.35 3.90 1.497 81.6 S18 -73.767 0.15 S19 87.670 8.00 1.497 81.6 S20 -52.379 2.00 1.741 52.6 S21 -173.758 D4 STOP ∞ 1.70 18.8 S23 257.443 2.00 1.80518 25.5 S24 45.725 8.00 1.6968 55.5 S25 -112.429 0.15 S26 75.692 3.50 1.883 40.8 S27 174.426 10.687 S28 -141.489 3.80 1.84666 23.8 S29 -44.946 1.50 1.741 52.6 S30 106.479 D5 S31 111.754 1.50 1.741 52.6 S32 69.805 2.03 S33 ∞ 4.00 1.497 81.6 S34 -82.846 0.15 S35 163.588 6.50 1.741 52.6 S36 -61.677 2.00 1.84666 23.8 S37 -324.519 D6 16.5 S38 ∞ 3.00 1.5168 64.2 S39 ∞ D7 IMAGE ∞

Wide Middle Tele D1 13.8237 13.8237 13.8237 D2 2.0000 18.1405 34.2797 D3 31.9922 22.6321 1.9943 D4 9.0359 2.2555 6.7542 D5 20.0263 15.8406 14.2563 D6 65.6648 69.8506 71.4349 D7 1.1391 1.0479 0.9568

FIGS. 17A to 17C show the longitudinal spherical aberration, the surface curvature, and the distortion aberration at the wide angle end, the middle end, and the telephoto end, respectively, of the zoom lens according to the fourth embodiment of the present invention. The longitudinal spherical aberration is shown for light with wavelengths of 656.2725 (nm), 587.5618 (nm), and 486.1327 (nm), respectively. The surface curvature is represented by tangential field curvature (T) for light with a wavelength of 587.5618 ) As a dotted line and a sagittal field curvature as a solid line. 18A shows a ray fan when the camera shake correction lens group G4-1 is moved in the upward direction perpendicular to the optical axis by 0.8 mm at the wide angle end, and FIG. 18B shows the ray fan when the camera shake correction lens group G4-1 FIG. 18C shows a ray fan when the camera shake correcting lens group G4-1 is moved in the downward direction perpendicular to the optical axis by 0.8 mm. FIG. 18C shows the ray fan when it is placed on the optical axis. Figs. 19A to 19C show a rail fan at an intermediate stage, and Figs. 20A to 20C show a rail fan at a telephoto end.

<Fifth Embodiment>

FIG. 21 illustrates a telephoto zoom lens according to a fifth embodiment. The first lens group G1 includes first through third lenses 11-5, 12-5, 5 and the fifth and sixth lenses 14-5 and 15-5 which are the rear group G1-b and the second lens group G2 is composed of the sixth, seventh, eighth, Lenses 22-5 and 23-5 and 24-5 and the third lens group G3 is composed of the tenth, eleventh and twelfth lenses 31-5 and 32-5, The fourth lens group G4 is composed of the first lens group G4-1, the third lens group G4-1, the fourth lens group G4-1, the fourth lens group G5-1, The 16th to 21st lenses 44-5, 45-5, 46-5, 47-5, 48-5, and 49-5. An infrared filter 50 is provided on the upper side of the fourth lens group G4.

 The following is lens data of the fifth embodiment.

f = 72.1 to 203.7 mm, F-number = 2.9 to 2.9, 2? = 34.46 to 11.80 Surface # Radius Thickness n _d v _d Semi-Aperture OBJECT ∞ S1 121.952 3.00 1.80610 40.7 36.5 S2 61.343 10.08 1.48749 70.4 S3 178.732 0.15 S4 67.894 10.00 1.49700 81.6 S5 243.429 D1 S6 67.289 3.00 1.80518 25.5 S7 51.676 2.052 S8 61.201 11.50 1.71300 53.9 S9 627.687 D2 S10 ∞ 1.70 1.90366 31.3 S11 30.914 7.937 16.5 S12 -52.126 1.70 1.48749 70.4 S13 39.336 8.00 1.92286 20.9 S14 -126.109 1.60 S15 -61.576 1.70 1.90366 31.3 S16 526.709 D3 S17 ∞ 3.90 1.90366 31.3 S18 -95.223 0.15 S19 93.923 8.00 1.49700 81.6 S20 -54.058 2.00 1.80518 25.5 S21 -163.378 D4 STOP ∞ 2.00 18.5 S23 83.334 2.00 1.80518 25.5 S24 40.355 8.00 1.56883 56 S25 -124.582 0.15 S26 62.954 4.00 1.80610 33.3 S27 96.238 5.935 S28 -246.434 4.20 1.84666 23.8 S29 -42.156 1.50 1.74950 35 S30 86.235 4.00 S31 179.073 3.00 1.71300 53.9 S32 66.323 11.084 S33 ∞ 4.00 1.49700 81.6 S34 -84.111 0.15 S35 179.088 6.00 1.58144 40.9 S36 -51.686 1.70 1.92286 20.9 S37 -110.188 D5 16.5 S38 ∞ 3.00 1.51680 64.2 S39 ∞ D6 IMAGE ∞

Wide Middle Tele D1 11.3724 11.3724 11.3724 D2 2.5200 16.9287 31.3374 D3 28.1817 21.5595 2.0020 D4 10.7115 2.9250 8.0738 D5 67.0264 67.0264 67.0264 D6 1.1052 0.9707 0.9264

FIGS. 22A to 22C show longitudinal spherical aberration, field curvature, and distortion aberration at the wide-angle end, the middle end, and the telephoto end, respectively, of the zoom lens according to the fourth embodiment of the present invention. The longitudinal spherical aberration is shown for light with wavelengths of 656.2725 (nm), 587.5618 (nm), and 486.1327 (nm), respectively. The surface curvature is represented by tangential field curvature (T) for light with a wavelength of 587.5618 ) As a dotted line and a sagittal field curvature as a solid line. 23A shows a ray fan when the camera shake correction lens group G4-1 is moved in the upward direction perpendicular to the optical axis by 0.8 mm at the wide angle end, and FIG. 23B shows the ray fan when the camera shake correction lens group G4-1 FIG. 23C shows a ray fan when the camera shake correction lens group G4-1 is moved in the downward direction perpendicular to the optical axis by 0.8 mm. FIG. 23C shows the ray fan when it is placed on the optical axis. Figs. 24A to 24C show a rail fan at an intermediate stage, and Figs. 25A to 25C show a rail fan at a telephoto end.

The following shows that the first to fifth embodiments satisfy the above-mentioned conditions (1) to (4), respectively.

First Embodiment Second Embodiment Third Embodiment Fourth Embodiment Fifth Embodiment Equation 1 0.38 0.42 0.4 0.38 0.38 Equation 2 1.08 1.18 1.15 1.09 1.07 Equation 3 0.30 0.34 0.30 0.28 0.30 Equation 4 29.7 23.5 33.1 33.1 29.7

The telephoto zoom lens according to the embodiments of the present invention is capable of correcting the shaking motion through the above-described lens configuration, keeping the F number from the wide-angle end to the telephoto end small, thereby obtaining bright pictures regardless of the angle of view, I have.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. . Accordingly, the true scope of the present invention should be determined by the appended claims.

1 is a diagram showing optical arrangements at a wide angle end, a middle end, and a telephoto end of a telephoto zoom lens according to a first embodiment of the present invention.

FIGS. 2A, 2B, and 2C are aberration diagrams showing spherical aberration, surface curvature, and distortion at the wide-angle end, the middle end, and the telephoto end, respectively, of the zoom optical system according to the first embodiment of the present invention.

FIGS. 3A to 3C are views showing a ray fan according to the first embodiment of the telephoto zoom lens according to the second embodiment of the present invention. FIG.

Figs. 4A to 4C show the ray fan by the camera shake correction lens group at the middle end of the zoom lens according to the first embodiment. Fig.

Figs. 5A to 5C show a ray fan by the camera shake correction lens group at the telephoto end of the zoom lens according to the first embodiment.

FIG. 6 is a diagram showing the optical arrangement of the telephoto zoom lens according to the second embodiment of the present invention at a wide angle end, a middle end, and a telephoto end.

7A, 7B and 7C are aberration diagrams showing spherical aberration, field curvature and distortion at the wide-angle end, the middle end, and the telephoto end of the zoom optical system according to the second embodiment of the present invention.

Figs. 8A to 8C show a ray fan by the camera shake correction lens group at the wide-angle end of the telephoto zoom lens according to the second embodiment.

9A to 9C show a ray fan by the camera shake correction lens group at the middle end of the zoom lens according to the second embodiment.

Figs. 10A to 10C show a ray fan by the camera shake correction lens group at the telephoto end of the zoom lens according to the second embodiment.

11 is a diagram showing optical arrangements at a wide angle end, a middle end, and a telephoto end of a telephoto zoom lens according to a third embodiment of the present invention.

12A, 12B, and 12C are aberration diagrams showing spherical aberration, field curvature, and distortion at the wide-angle end, the middle end, and the telephoto end, respectively, of the zoom optical system according to the third embodiment of the present invention.

FIGS. 13A to 13C show a ray fan by a group of camera shake correction lenses at the wide-angle end of the telephoto zoom lens according to the third embodiment.

Figs. 14A to 14C show a ray fan by the camera shake correction lens group at the intermediate stage of the zoom lens according to the third embodiment.

Figs. 15A to 15C show a ray fan by the camera shake correction lens group at the telephoto end of the zoom lens according to the third embodiment.

16 is a diagram showing the optical arrangement of the telephoto zoom lens according to the fourth embodiment of the present invention at the wide-angle end, the middle end, and the telephoto end.

17A, 17B and 17C are aberration diagrams showing spherical aberration, field curvature and distortion at the wide-angle end, the middle end, and the telephoto end of the zoom optical system according to the fourth embodiment of the present invention.

18A to 18C are diagrams showing a ray fan by the camera shake correction lens group at the wide angle end of the telephoto zoom lens according to the fourth embodiment.

Figs. 19A to 19C show the ray fan by the camera shake correction lens group at the middle end of the zoom lens according to the fourth embodiment.

20A to 20C are diagrams showing a ray fan by the camera shake correction lens group at the telephoto end of the zoom lens according to the fourth embodiment.

FIG. 21 is a diagram showing the optical arrangement of the telephoto zoom lens according to the fifth embodiment of the present invention at the wide-angle end, the middle end, and the telephoto end.

FIGS. 22A, 22B, and 22C are aberration diagrams showing spherical aberration, field curvature, and distortion at the wide-angle end, the middle end, and the telephoto end, respectively, of the zoom optical system according to the fifth embodiment of the present invention.

FIGS. 23A to 23C show a ray fan by the camera shake correction lens group at the wide angle end of the telephoto zoom lens according to the fifth embodiment.

24A to 24C show a ray fan by the camera shake correction lens group at the middle end of the zoom lens according to the fifth embodiment.

25A to 25C are diagrams showing a ray fan by the camera shake correction lens group at the telephoto end of the zoom lens according to the fifth embodiment.

Description of the Related Art

G1 ... first lens group G2 ... second lens group

G3 ... First lens group G4 ... Second lens group

G1-a &lt; / RTI &gt; &lt; RTI ID = 0.0 &gt;

G4-1 ... Camera shake correction lens group

Claims (7)

Arranged in this order from the object side, A first lens group having a positive refractive power, a front lens group fixed when focusing according to an object distance, and a rear lens group having positive refractive power and moved upon focusing according to an object distance; A second lens group having a negative refracting power and being moved during magnification; A third lens group having a positive refracting power and being moved during magnification; And a fourth lens group including a group of camera shake correction lenses that correct the image blur due to camera shake by moving in a direction perpendicular to the optical axis, A telephoto zoom lens satisfying the following conditional expression. <Conditional expression> 0.35 < _f4C / fT < 0.46 Here, f _4C , f _T Are the focal length of the camera shake correction lens group and the total focal length at the telephoto end, respectively. Arranged in this order from the object side, A first lens group having a positive refractive power, a front lens group fixed when focusing according to an object distance, and a rear lens group having positive refractive power and moved upon focusing according to an object distance; A second lens group having a negative refracting power and being moved during magnification; A third lens group having a positive refracting power and being moved during magnification; And a fourth lens group including a group of camera shake correction lenses that correct the image blur due to camera shake by moving in a direction perpendicular to the optical axis, A telephoto zoom lens satisfying the following conditional expression. <Conditional expression> 1.0 < f _4C / f _W < 1.3 Here, f _4C , f _W Are the focal lengths of the camera shake correction lens group and the total focal length at the wide angle end, respectively. Arranged in this order from the object side, A first lens group having a positive refractive power, a front lens group fixed when focusing according to an object distance, and a rear lens group having positive refractive power and moved upon focusing according to an object distance; A second lens group having a negative refracting power and being moved during magnification; A third lens group having a positive refracting power and being moved during magnification; And a fourth lens group including a group of camera shake correction lenses that correct the image blur due to camera shake by moving in a direction perpendicular to the optical axis, A telephoto zoom lens satisfying the following conditional expression. <Conditional expression> 0.25 < _f4C / L < 0.35 Here, f _4C and L are the focal length of the camera shake correction lens group and the distance from the apex of the first object side of the first lens group to the image surface. 4. The method according to any one of claims 1 to 3, A telephoto zoom lens satisfying the following conditional expression. <Conditional expression> 20 < v _2- v ₁ < 35 Here, v ₁ and v ₂ are the Abbe numbers of the first and second lenses of the first lens group, respectively. 5. The method of claim 4, Wherein the first and second lenses of the first lens group form a cemented lens, and the Abbe number of the second lens is smaller than 80. The telephoto zoom lens of claim 1, 4. The method according to any one of claims 1 to 3, A telephoto zoom lens in which the F number is fixed at the time of magnification. 4. The method according to any one of claims 1 to 3, Wherein the camera shake correction lens group is composed of a single lens of a meniscus lens, a single lens of a biconvex lens, and a single meniscus lens.

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