JP2015004917A - Zoom lens and image capturing device having the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a zoom lens which offers a wide view angle, a high zoom ratio, superior optical performance throughout an entire zoom range, and compactness of the entire system.SOLUTION: A zoom lens comprises: in order from the object side to the image side, a first lens group which is stationary when zooming and has positive refractive power; a second lens group which moves when zooming and has negative refractive power; a third lens group which moves when zooming and has negative refractive power; a fourth lens group which moves when zooming and has positive refractive power; and a fifth lens group which is stationary when zooming and has positive refractive power. A focal length f1 of the first lens group, a focal length f2 of the second lens group, a focal length f3 of the third lens group, a focal length f4 of the fourth lens group, and an imaging magnification β4w of the fourth lens group at the wide-angle end are appropriately set.

Description

  The present invention relates to a zoom lens and an image pickup apparatus having the same, and is particularly suitable as an image pickup optical system of an image pickup apparatus such as a broadcast television camera, a movie camera, a video camera, a digital still camera, and a silver salt photographic camera. .

  In recent years, there has been a demand for an imaging optical system used in an imaging apparatus that is a zoom lens having a small size and light weight, a wide angle of view, a high zoom ratio, and high optical performance. In particular, an imaging device such as a CCD or CMOS used in a television camera or a movie camera as a professional moving image shooting system has a substantially uniform resolution in the entire imaging range. Therefore, a zoom lens used in an imaging apparatus using these imaging devices is strongly required to have a substantially uniform resolution and a high resolution from the center of the screen to the periphery of the screen. In addition, a reduction in size and weight is also required for an imaging mode that emphasizes mobility and operability.

  As a zoom lens having a wide angle of view and a high zoom ratio, a positive lead type five-unit zoom lens is known which includes a lens unit having a positive refractive power closest to the object side and is composed of five lens units as a whole. (Patent Documents 1 to 3).

  In the zoom lenses disclosed in Patent Documents 1 to 3, in order from the object side to the image side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a negative refractive power, and a positive lens The lens unit includes a fourth lens unit having a refractive power and a fifth lens unit having a positive refractive power. A zoom lens having a lens configuration in which the first lens group and the fifth lens group are fixed during zooming and the second lens group, the third lens group, and the fourth lens group move is disclosed.

JP-A-1-126614 JP-A-8-234105 JP 2011-107693 A

  In the 5-group zoom lens having the above-described configuration, in order to obtain high optical performance while maintaining a wide angle of view and a high zoom ratio, the refractive power of each lens group, movement conditions during zooming, etc. are appropriately set. It becomes important.

  In particular, it is important to appropriately set the refractive power of the first lens group, the refractive powers of the second, third, and fourth lens groups as the variable power lens group, the imaging magnification of the fourth lens group, and the like. come. In order to obtain high optical performance over the entire zoom range while reducing the size and weight of the entire system, the movement conditions of the third lens group and the fourth lens group from the wide-angle end to the intermediate zoom position are appropriately set. Setting is important. If these configurations are not set appropriately, it becomes difficult to obtain a zoom lens having a wide field angle and a high zoom ratio and high optical performance over the entire zoom range.

  In the zoom lens of Patent Document 1, the combined refractive power of the third lens group and the fourth lens group is negative, the effective diameter of the lens group on the image side of the first lens group is increased, and the entire system is reduced in size. However, it is difficult to widen the angle of view. In the zoom lens of Patent Document 2, the negative refracting power of the third lens group is too strong compared to the second lens group, the fluctuations of various aberrations accompanying zooming become large, and the effective diameter of the first lens group becomes large. It is difficult to downsize the entire system.

  An object of the present invention is to provide a zoom lens having a wide angle of view, a high zoom ratio and high optical performance over the entire zoom range, and a small zoom lens for the entire system, and an image pickup apparatus having the same.

The zoom lens according to the present invention includes, in order from the object side to the image side, a first lens group having a positive refractive power that does not move for zooming, a second lens group having a negative refractive power that moves when zooming, and a zoom lens when zooming. In a zoom lens having a third lens group having a negative refractive power that moves, a fourth lens group having a positive refractive power that moves upon zooming, and a fifth lens group having a positive refractive power that does not move for zooming,
The focal length of the first lens group is f1, the focal length of the second lens group is f2, the focal length of the third lens group is f3, the focal length of the fourth lens group is f4, and the fourth lens at the wide angle end. When the imaging magnification of the lens group is β4w,
−3.5 <f1 / f2 <−1.0
−0.40 <f4 / f3 <−0.01
−0.50 <f1 / f3 <−0.01
| 1 / β4w | <0.5
It satisfies the following conditional expression.

  According to the present invention, it is possible to obtain a zoom lens having a wide angle of view, a high zoom ratio, high optical performance over the entire zoom range, and a small overall system.

FIG. 3 is a lens cross-sectional view at the wide angle end of the zoom lens according to the first exemplary embodiment. (A), (B), (C) are aberration diagrams of Example 1 at the wide-angle end, the focal length of 29.7 mm, and the telephoto end. 6 is a lens cross-sectional view at a wide angle end of a zoom lens according to Embodiment 2. FIG. (A), (B), (C) are aberration diagrams of Example 2 at the wide-angle end, the focal length of 45.6 mm, and the telephoto end. 6 is a lens cross-sectional view at a wide angle end of a zoom lens according to Embodiment 3; FIG. (A), (B), (C) are aberration diagrams of Example 3 at the wide-angle end, the focal length 41.3 mm, and the telephoto end. 6 is a lens cross-sectional view at a wide angle end of a zoom lens according to Embodiment 4; FIG. (A), (B), (C) are aberration diagrams of Example 4 at the wide-angle end, the focal length of 47.4 mm, and the telephoto end. 6 is a lens cross-sectional view at the wide-angle end of a zoom lens according to Example 5. FIG. (A), (B), (C) are aberration diagrams of Example 5 at the wide-angle end, the focal length of 57.3 mm, and the telephoto end. 10 is a lens cross-sectional view at a wide angle end of a zoom lens according to Example 6. FIG. (A), (B), (C) are aberration diagrams of Example 6 at the wide-angle end, the focal length of 77.3 mm, and the telephoto end. It is the schematic of the paraxial refractive power arrangement | positioning of the zoom lens of this invention. It is an optical path diagram showing the change of the on-axis ray and the off-axis ray at the wide-angle end, the zoom middle, and the telephoto end in Example 4 of the present invention. It is the schematic showing the movement locus | trajectory in zooming of the zoom lens of this invention. It is a principal part schematic of the imaging device of this invention.

  Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. The zoom lens (a plurality of lens groups included in the zoom lens) of the present invention is as follows in order from the object side to the image side.

  For zooming, the first lens unit has a fixed positive refractive power, the second lens unit has a negative refractive power (moves upon zooming), and the negative lens moves (moves upon zooming). The third lens unit having a refractive power of 5 mm. Further, the fourth lens unit moves in order to correct the image plane variation accompanying zooming (moves during zooming), and the fifth lens unit has a positive refractive power that does not move for zooming. Is done.

  FIG. 1 is a lens cross-sectional view when focusing on infinity at the wide-angle end (short focal length end) of Numerical Example 1 as Embodiment 1 of the present invention. 2A, 2 </ b> B, and 2 </ b> C are the wide-angle end of Numerical Example 1 and f = 29.7 mm (the same applies hereinafter when the Numerical Example described later is expressed in mm), and telephoto. It is a longitudinal aberration diagram when focusing on infinity at the end (long focal length end). Numerical Example 1 has a zoom ratio of 2.80 and an F number of 2.80.

  FIG. 3 is a lens cross-sectional view when focusing on infinity at the wide-angle end of Numerical Embodiment 2 as Embodiment 2 of the present invention. 4A, 4 </ b> B, and 4 </ b> C are longitudinal aberration diagrams when focusing on infinity at the wide-angle end, f = 45.6 mm, and the telephoto end according to Numerical Example 2. FIG. Numerical Example 2 has a zoom ratio of 4.50 and an F number of 2.80.

  FIG. 5 is a lens cross-sectional view when focusing on an object at infinity at the wide-angle end of Numerical Embodiment 3 as Embodiment 3 of the present invention. 6A, 6B, and 6C are longitudinal aberration diagrams when focusing on an object at infinity at the wide-angle end, f = 41.3 mm, and the telephoto end according to Numerical Example 3. FIG. The third embodiment has a zoom ratio of 4.00 and an F number of 2.80.

  FIG. 7 is a lens cross-sectional view when focusing on an object at infinity at the wide angle end according to Numerical Example 4 as Embodiment 4 of the present invention. 8A, 8B, and 8C are longitudinal aberration diagrams when focusing on an object at infinity at the wide-angle end, f = 47.4 mm, and the telephoto end according to Numerical Example 4. FIG. Numerical Example 4 has a zoom ratio of 4.80 and an F number of 2.80.

  FIG. 9 is a lens cross-sectional view when focusing on an object at infinity at the wide angle end according to Numerical Example 5 as Example 5 of the present invention. FIGS. 10A, 10B, and 10C are longitudinal aberration diagrams when focusing on an object at infinity at the wide-angle end, f = 57.3 mm, and the telephoto end according to Numerical Example 5. FIGS. Numerical Example 5 has a zoom ratio of 3.30 and an F number of 2.80.

  FIG. 11 is a lens cross-sectional view when focusing on an object at infinity at the wide angle end according to Numerical Example 6 as Example 6 of the present invention. 12A, 12B, and 12C are longitudinal aberration diagrams when focusing on an object at infinity at the wide-angle end, f = 77.3 mm, and the telephoto end according to Numerical Example 6. FIG. Numerical Example 6 has a zoom ratio of 3.00 and an F number of 2.80.

  FIG. 13 is an explanatory diagram of a paraxial refractive power arrangement according to the zoom lens of the present invention. FIGS. 14A, 14B, and 14C are explanatory diagrams of the optical paths of the on-axis light beam and the off-axis light beam at the wide-angle end, the intermediate zoom position, and the telephoto end according to the fourth embodiment of the present invention. FIG. 15 is an explanatory diagram of the movement locus of each lens unit during zooming from the wide-angle end to the telephoto end of the zoom lens according to the present invention. FIG. 16 is a schematic view of the main part of the imaging apparatus of the present invention.

  In the movement locus of each lens group and the lens cross-sectional views in zooming in FIG. 15, the left is the subject (object) side (front), and the right is the image side (rear). U1 is a first lens unit having a positive refractive power that does not move for zooming. U2 is a second lens unit (variator) having a negative refractive power for zooming, and zooms from the wide-angle end to the telephoto end by linearly moving on the optical axis side on the optical axis. . U3 is a third lens unit (variator) having a negative refractive power for zooming, and moves non-linearly on the optical axis along a locus convex toward the image side from the wide-angle end to the telephoto end.

  U4 is a fourth lens unit (compensator) having a positive refractive power, and moves in a non-linear manner on the optical axis along a locus convex to the image side in order to correct image plane fluctuations accompanying zooming. SP is an aperture stop, and U5 is a fifth lens group (relay group) having a positive refractive power that has a stationary imaging function for zooming. A focal length conversion converter (extender) or the like may be mounted in the fifth lens unit U5. I is an image plane, which corresponds to the imaging plane of the solid-state imaging device.

  In each aberration diagram, the solid line and the broken line in the spherical aberration are the e line and the g line, respectively. A solid line and an alternate long and short dash line in astigmatism are a sagittal image surface and a meridional image surface in the e line, respectively, and lateral chromatic aberration is represented by the g line. ω is a half angle of view (degree) in paraxial, and Fno is an F number. In the longitudinal aberration diagram, the spherical aberration is 0.4 mm, the astigmatism is 0.4 mm, the distortion is 10%, and the chromatic aberration of magnification is 0.1 mm.

  In each of the following embodiments, the wide-angle end and the telephoto end refer to zoom positions when the zoom lens unit is positioned at both ends of a range in which the zoom lens group can move on the optical axis.

  The zoom lens of each embodiment includes, in order from the object side to the image side, a first lens unit U1 having a positive refractive power that does not move for zooming, a second lens unit U2 having a negative refractive power for zooming, A third lens unit U3 having negative refracting power for magnification is provided. Furthermore, it has a fourth lens unit U4 having a positive refractive power that moves in order to correct image plane fluctuations accompanying zooming. Further, for zooming, the fifth lens unit U5 has a fixed positive refractive power.

The focal length of the first lens unit U1 is f1, the focal length of the second lens unit U2 is f2, the focal length of the third lens unit U3 is f3, and the focal length of the fourth lens unit U4 is f4. The imaging magnification of the fourth lens unit U4 at the wide angle end is β4w. At this time,
−3.5 <f1 / f2 <−1.0 (1)
−0.40 <f4 / f3 <−0.01 (2)
−0.50 <f1 / f3 <−0.01 (3)
| 1 / β4w | <0.5 (4)
The following conditional expression is satisfied.

In each embodiment, the focal length of the entire system at the wide-angle end is fw, the zoom ratio is Z,
fm = fw × Z ^0.6 (P)
An intermediate zoom position at which the focal length fm that satisfies the above is set as a zoom position m.

In the zoom ratio Z, the focal length of the entire system at the wide-angle end is fw, and the focal length of the entire system at the telephoto end is ft. At this time,
Z = ft / fw
It is represented by In the five-group zoom lens composed of the five lens groups described above, the focal length fm at the zoom position m specified by the above-described formula (P) is the focal length fm of the first lens group and the first focal length at the zoom position m. The lateral magnification of the N lens group (N = 2 to 5) is βNm. At this time, it can be expressed by the following formula.

fm = f1 × (β2m × β3m × β4m × β5m) (X)
However, each lateral magnification and focal length are values when the object distance is infinite. In addition, since it is a zoom lens, it is necessary that the image point satisfies a certain condition regardless of zooming. Further, since the fifth lens group does not move for zooming, the lateral magnification β5m does not change during zooming.

  Therefore, in order to obtain a predetermined focal length fm, (β2m × β3m × β4m) may be constant. However, since the lens group arrangement capable of achieving this condition is not uniquely determined, it is possible to select the movement locus of each moving lens group for zooming within a predetermined zoom range. Narrowing the distance between the first lens unit U1 and the second lens unit U2 corresponds to reducing the lateral magnification | β2m |.

  Therefore, in the zoom lens of the present invention, in the zoom range including the intermediate zoom position m, the interval between the third lens unit U3 and the fourth lens unit U4 is set while the interval between the first lens unit U1 and the second lens unit U2 is reduced. It is spreading. Thus, an optical arrangement is adopted in which the image point of the entire system is kept constant and the value of the lateral magnification β3m × β4m is increased.

  When the amount of movement of the second lens unit U2 during zooming is suppressed, the absolute value of the lateral magnification β2m in the equation (X) decreases. For this reason, in order to make the focal length fm constant, it is necessary to increase the value of the lateral magnification β3m × β4m. The combined focal length fab of the two lenses having the focal lengths fa and fb and the principal point interval e ′ can be expressed by the following equation.

1 / fab = 1 / fa + 1 / fb−e ′ / (fa × fb) (Y)
Here, in the case of fa <0, fb> 0, e ′> 0 and | fa |> | fb |, if the principal point interval e ′ is increased, the combined focal length fab is decreased.

  Now, let the focal lengths fa and fb in the above equation (Y) be the third lens unit U3 and the fourth lens unit U4 in the zoom lens of the present invention. Then, the combined focal length f34m of the third lens group U3 and the fourth lens group U4 becomes smaller as the distance between the third lens group U3 and the fourth lens group U4 becomes wider.

  FIG. 13 is a schematic diagram showing the relationship between the combined focal length and lateral magnification of the third lens unit U3 and the fourth lens unit U4 at a certain zoom position in the zoom lens of the present invention. The members indicated by arrows in FIG. 13 represent the composite lens group of the third lens group U3 and the fourth lens group U4, and fL and fS indicated by the arrows are a composite lens group having a long composite focal length and a short composite lens group, respectively. It is. Obj is an object point, and Img is an image point. sL and sS are distances from the object points of the combined focal lengths fL and fS, respectively, and s'L and s'S are distances from the image points of the combined focal lengths fL and fS, respectively.

  In FIG. 13, the absolute value | β | of the lateral magnification is expressed as sL / s′L and sS / s ′S, respectively, at the combined focal lengths fL and fS. As is apparent from FIG. 13, when the composite lens group is arranged so that the object point and the image point of the composite lens group are constant, the absolute value | β | of the lateral magnification increases when the focal length of the composite lens group is small. Become.

  As shown in FIG. 13, in the zoom lens according to the present invention, the combined focal length of the third lens unit U3 and the fourth lens unit U4 is reduced, so that the combined lateral of the third lens unit U3 and the fourth lens unit U4 is obtained. The magnification can be increased. That is, by increasing the distance between the third lens unit U3 and the fourth lens unit U4, the refractive power is arranged so as not to extend the second lens unit U2 to the image side while keeping the focal length of the entire lens system constant. Can do.

  As shown in FIG. 14 (Example 4), the first lens unit U1 and the second lens unit U2 at an intermediate zoom position (zoom intermediate) m at which the incident height of the off-axis ray in the first lens unit U1 is the highest. Reduce the interval. This reduces the incident height of off-axis rays and reduces the effective diameter of the first lens unit U1. The spherical aberration SAi in a certain lens unit i satisfies the following relationship (Z).

SAi∝Ii∝hi4 (Z)
Here, Ii is the spherical aberration coefficient of the lens unit i, and hi is the incident height of the axial light beam in the lens unit i. The spherical aberration of the entire system is expressed by the following equation (Z-2).

SA = ΣSAi (Z-2)
Since the incident height hi of the axial light beam to the lens changes depending on the zoom arrangement, the spherical aberration SAi changes during zooming. In general, in a zoom lens, spherical aberration is reduced by determining a spherical aberration coefficient Ii that makes the spherical aberration SAi zero at the wide-angle end and the telephoto end.

  As shown in FIG. 14, in the zoom lens according to the present invention, since the light emitted from the fourth lens unit U4 is substantially afocal, zooming is not performed in the combined lens unit of the third lens unit U3 and the fourth lens unit U4. At this time, the incident height hi does not change. The lens groups whose incident height hi greatly changes during zooming are the first lens group U1 and the second lens group U2. The incident height h1 to the first lens unit U1 increases from the wide-angle end to the telephoto end in proportion to the focal length.

  In contrast, the incident height h2 to the second lens unit U2 increases less than the incident height h1 because the distance between the first lens unit U1 and the second lens unit U2 is separated. Therefore, if the spherical aberration SAi is 0 at the wide-angle end and the telephoto end, the spherical aberration SAi does not become 0 at the zoom position m, and the spherical aberration remains excessively.

  FIG. 15 is a schematic diagram showing a movement locus during zooming in the zoom lens of the present invention. Increasing the distance between the third lens unit U3 and the fourth lens unit U4 at the zoom position m with respect to the wide-angle end reduces the incident height h3 to the third lens unit U3, and corrects the spherical aberration to be under. Thus, the remaining spherical aberration at the zoom position m is reduced.

  Conditional expression (1) relates to the ratio between the focal length f1 of the first lens unit U1 and the focal length f2 of the second lens unit U2. By satisfying conditional expression (1), the effective lens diameter of the first lens unit U1 is reduced and the total lens length is shortened while widening the angle of view.

  If the upper limit of conditional expression (1) is exceeded and the focal length of the first lens unit U1 becomes small and the refractive power of the first lens unit U1 becomes too strong, correction of aberration fluctuations during zooming becomes difficult. Further, since the negative refractive power of the second lens unit U2 is insufficient with respect to the first lens unit U1, the amount of movement (zoom stroke) of the second lens unit U2 during zooming increases. The total lens length (the value obtained by adding the back focus (air conversion distance from the final lens surface to the image plane) to the distance from the first lens surface to the final lens surface) increases.

  Conversely, when the focal length of the first lens unit U1 increases beyond the lower limit of the conditional expression (1) and the refractive power of the first lens unit U1 is insufficient, a wide angle of view and a reduction in size and weight of the entire system are caused. It becomes difficult. Conditional expression (2) relates to the ratio of the focal length f4 of the fourth lens unit U4 to the focal length f3 of the third lens unit U3. By satisfying conditional expression (2), the entire lens system is reduced in size. If the absolute value of the focal length of the third lens unit U3 increases beyond the upper limit of conditional expression (2) and the negative refractive power of the third lens unit becomes weak, various aberrations at an intermediate zoom position, particularly spherical aberration Correction becomes difficult.

  On the contrary, if the absolute value of the focal length of the third lens unit U3 becomes smaller than the lower limit of the conditional expression (2) and the negative refractive power of the third lens unit becomes too large, the third lens unit U3 The focus position fluctuates (out of focus) with respect to movement in the optical axis direction, and the optical performance deteriorates. Conditional expression (3) relates to the ratio between the focal length f1 of the first lens unit U1 and the focal length f3 of the third lens unit U3. Satisfying conditional expression (3) achieves good optical performance over the entire zoom range while reducing the size of the entire lens system.

  If the absolute value of the focal length of the third lens unit U3 is reduced beyond the lower limit of the conditional expression (3) and the negative refractive power of the third lens unit L3 is too strong, the aberration variation increases during zooming. come. Conversely, if the absolute value of the focal length of the third lens unit U3 increases beyond the upper limit of conditional expression (3) and the negative refractive power of the third lens unit U3 becomes too weak, the third lens in zooming The zoom stroke of the group U3 increases and the total lens length increases.

  Conditional expression (4) defines the reciprocal of the lateral magnification β4w of the fourth lens unit U4 at the wide-angle end when the light beam enters from infinity. By satisfying conditional expression (4), the light beam emitted from the fourth lens unit U4 becomes substantially afocal, so it is easy to reduce the number of constituent lenses of the fifth lens unit U5. To reduce weight and weight. If the upper limit of conditional expression (4) is exceeded, the fifth lens unit U5 needs to have a strong positive refractive power. Therefore, the number of constituent lenses of the fifth lens unit U5 increases, and the entire system is reduced in size and weight. It becomes difficult. More preferably, the numerical ranges of conditional expressions (1) to (4) are set as follows.

−3.3 <f1 / f2 <−1.0 (1a)
−0.38 <f4 / f3 <−0.03 (2a)
−0.40 <f1 / f3 <−0.02 (3a)
| 1 / β4w | <0.3 (4a)
In each embodiment, it is more preferable that the following conditional expression is satisfied.

The distance between the third lens unit U3 and the fourth lens unit U4 at the wide angle end is L3w. The distance between the third lens unit U3 and the fourth lens unit U4 at the zoom position m represented by the formula (P) is L3m. At this time,
0.01 <L3w / L3m <1.10 (5)
It is preferable to satisfy the following conditional expression:

  Conditional expression (5) defines the ratio of the distance between the third lens unit U3 and the fourth lens unit U4 at the wide-angle end and the zoom position m. By satisfying conditional expression (5), the entire lens system is reduced in size and weight, and aberration variations during zooming are reduced. If the upper limit of conditional expression (5) is exceeded and the distance between the third lens unit U3 and the fourth lens unit U4 becomes too small at the zoom position m with respect to the wide-angle end, correction of spherical aberration becomes difficult. Further, since the second lens unit U2 moves too much to the image side at the zoom position m, it is difficult to reduce the size and weight of the first lens unit U1.

  On the other hand, if the distance between the third lens unit U3 and the fourth lens unit U4 becomes too narrow at the wide angle end beyond the lower limit of the conditional expression (5), the third lens unit U3 during zooming from the telephoto side to the wide angle end. And the fourth lens unit U4 may approach each other and collide with each other, which is not preferable. In addition, the distance between the third lens unit U3 and the fourth lens unit U4 becomes too wide at the zoom intermediate position m, and the correction of spherical aberration becomes excessive. More preferably, the numerical range of conditional expression (5) is set as follows.

0.03 <L3w / L3m <1.00 (5a)
The zoom lens of each embodiment is preferably configured as follows.

  During zooming, it is preferable to take a zoom locus where the third lens unit U3 is closest to the object side at the wide-angle end. According to this, the zoom stroke of the third lens unit U3 can be shortened, the number of constituent lenses of the first lens unit U1 and the fifth lens unit U5 can be easily reduced, and the entire lens system can be downsized. Weight reduction becomes easy.

  Furthermore, it is preferable that the third lens unit U3 having a negative refractive power has one or more negative lenses and one or more positive lenses. By using a negative lens and a positive lens for the third lens unit U3, it becomes easy to effectively correct variations in various aberrations due to zooming, particularly variations in chromatic aberration. The second lens unit U2 is preferably composed of two negative lenses, a positive lens, and a negative lens in order from the object side to the image side. The fourth lens unit U4 is preferably composed of one positive lens or two positive lenses. This makes it easy to reduce fluctuations in various aberrations during zooming.

Next, the lens configuration of the zoom lens of each embodiment will be described.
[Example 1]
Example 1 corresponds to Numerical Example 1. In Numerical Example 1, the lens configuration of each lens unit is as follows.

  The first lens unit U1 corresponds to the first to fifteenth lens surfaces, and in order from the object side to the image side, three negative lenses, two positive lenses, a cemented lens in which a negative lens and a positive lens are cemented, It consists of a positive lens. The second lens unit U2 corresponds to the fifteenth through twenty-third lens surfaces, and includes two negative lenses, a positive lens, and a negative lens in order from the object side to the image side. The third lens unit U3 corresponds to the 24th to 26th lens surfaces, and includes a cemented lens in which a negative lens and a positive lens are cemented in order from the object side to the image side.

  The fourth lens unit U4 corresponds to the 27th to 30th lens surfaces, and is composed of two positive lenses in order from the object side to the image side. The fifth lens unit U5 corresponds to the thirty-second lens surface to the forty-first lens surface, and in order from the object side to the image side, a cemented lens obtained by cementing a positive lens, a positive lens, and a negative lens, a positive lens, a positive lens, and a negative lens It is comprised from the cemented lens which joined the lens. The first negative lens counted from the object side of the first lens unit U1 has an aspherical surface, and corrects distortion aberration, field curvature and the like mainly on the wide angle side.

  Numerical Example 1 satisfies the conditional expressions (1) to (5). Numerical Example 1 achieves good optical performance while achieving a focal length of 16.00 at the wide-angle end, a zoom ratio of 2.80, a wide angle of view, a high zoom ratio, and a reduction in size and weight of the entire system. ing. Note that the cemented lens in the present embodiment may be configured as a separated lens having a minute air interval. This is within the assumption of deformation and change as the lens shape in the zoom lens of the present invention, and the same applies to all the embodiments below.

[Example 2]
Example 2 corresponds to Numerical Example 2. In Numerical Example 2, the lens configuration of each lens unit is as follows.

  The first lens unit U1 corresponds to the first lens surface to the eighteenth lens surface, and is composed of three negative lenses, two positive lenses, a negative lens, and three positive lenses in order from the object side to the image side. . The second lens unit U2 corresponds to the 19th to 26th lens surfaces. The third lens unit U3 corresponds to the 27th to 29th lens surfaces. The fourth lens unit U4 corresponds to the 30th to 33rd lens surfaces. The lens configurations of the second lens unit U2, the third lens unit U3, and the fourth lens unit U4 are the same as those in the first embodiment.

  The fifth lens unit U5 corresponds to the 35th lens surface to the 42nd lens surface, and includes, in order from the object side to the image side, a positive lens, a cemented lens in which a positive lens and a negative lens are cemented, a positive lens, and a negative lens. It consists of cemented cemented lenses. The negative lens in the first scene counted from the object side of the first lens unit U1 has an aspherical surface, and corrects distortion aberration, field curvature, and the like mainly on the wide angle side. Numerical Example 2 satisfies the conditional expressions (1) to (5). In Numerical Example 2, the focal length at the wide-angle end is 18.50 mm, the zoom ratio is 4.50, the wide angle of view is increased, the zoom ratio is increased, and the entire system is reduced in size and weight. Yes.

[Example 3]
Example 3 corresponds to Numerical Example 3. In Numerical Example 3, the lens configuration of each lens group is as follows.

  The first lens unit U1 corresponds to the first lens surface to the eighteenth lens surface, and is composed of three negative lenses, two positive lenses, a negative lens, and three positive lenses in order from the object side to the image side. . The second lens unit U2 corresponds to the 19th lens surface to the 25th lens surface, and is composed of a negative lens, a cemented lens in which a negative lens and a positive lens are cemented, and a negative lens in order from the object side to the image side. The third lens unit U3 corresponds to the 26th to 28th lens surfaces. The lens configuration of the third lens unit U3 is the same as that of the first embodiment. The fourth lens unit U4 corresponds to the 29th lens surface and the 30th lens surface and is composed of one positive lens.

  The fifth lens unit U5 corresponds to the thirty-second lens surface to the forty-first lens surface, and is arranged in order from the object side to the image side, a cemented lens in which a positive lens and a negative lens are cemented, a positive lens, a positive lens, and a negative lens. Are cemented lenses. The first negative lens counted from the object side of the first lens unit U1 has an aspherical surface, and corrects distortion aberration, field curvature and the like mainly on the wide angle side.

  Numerical Example 3 satisfies the conditional expressions (1) to (5). In Numerical Example 3, the focal length at the wide-angle end is 18.00 mm, the zoom ratio is 4.00, the wide angle of view is increased, the zoom ratio is increased, and the entire system is reduced in size and weight. Yes.

[Example 4]
Example 4 corresponds to Numerical Example 4. In Numerical Example 4, the lens configuration of each lens group is as follows.

  The first lens unit U1 corresponds to the first lens surface to the 18th lens surface, and in order from the object side to the image side, three negative lenses, a positive lens, a cemented lens in which a negative lens and a positive lens are cemented, and a negative lens And a positive lens and a cemented lens and two positive lenses. The second lens unit U2 corresponds to the 19th to 26th lens surfaces. The third lens unit U3 corresponds to the 27th to 29th lens surfaces. The fourth lens unit U4 corresponds to the 30th to 33rd lens surfaces. The lens configurations of the second lens unit U2, the third lens unit U3, and the fourth lens unit U4 are the same as those in the first embodiment.

  The fifth lens unit U5 corresponds to the 35th lens surface to the 42nd lens surface, and cementes a positive lens, a cemented lens composed of a positive lens and a negative lens, and a positive lens and a negative lens in order from the object side to the image side. It consists of a cemented lens. The first negative lens and the tenth positive lens counted from the object side of the first lens unit U1 have aspheric surfaces. The first lens mainly corrects distortion and field curvature on the wide-angle side, and the tenth lens mainly corrects distortion and field curvature from the zoom position m to the telephoto side.

  Numerical Example 4 satisfies the conditional expressions (1) to (5). In Numerical Example 4, the focal length at the wide-angle end is 18.50 mm, the zoom ratio is 4.80, a wide angle of view, a high zoom ratio, and the entire system is reduced in size and weight while obtaining good optical performance. .

[Example 5]
Example 5 corresponds to Numerical Example 5. In Numerical Example 5, the lens configuration of each lens unit is as follows.

  The first lens unit U1 corresponds to the first lens surface to the sixteenth lens surface, and in order from the object side to the image side, three negative lenses, a positive lens, a cemented lens in which a negative lens and a positive lens are cemented, and a negative lens And a positive lens and a positive lens. The second lens unit U2 corresponds to the 17th to 24th lens surfaces. The lens configuration of the second lens unit U2 is the same as that of the first embodiment. The third lens unit U3 corresponds to the 25th lens surface to the 26th lens surface and is composed of one negative lens.

  The fourth lens unit U4 corresponds to the 27th to 30th lens surfaces. The lens configuration of the fourth lens unit U4 is the same as that of the first embodiment. The fifth lens unit U5 corresponds to the thirty-second lens surface to the forty-first lens surface, and includes a positive lens, a negative lens, and three positive lenses in order from the object side to the image side.

  Numerical Example 5 satisfies the conditional expressions (1) to (5). This embodiment does not use an aspheric lens. Numerical Example 5 achieves good optical performance while achieving a focal length of 28.00 mm at the wide-angle end, a zoom ratio of 3.30, a wide angle of view, a high zoom ratio, and a reduction in size and weight of the entire system. Yes.

[Example 6]
Example 6 corresponds to Numerical Example 6. In Numerical Example 6, the lens configuration of each lens unit is as follows.

  The first lens unit U1 corresponds to the first to ninth lens surfaces, and is composed of a negative lens, two positive lenses, and a cemented lens in which a negative lens and a positive lens are cemented in order from the object side to the image side. ing. The second lens unit U2 corresponds to the tenth to seventeenth lens surfaces. The third lens unit U3 corresponds to the 18th to 20th lens surfaces. The fourth lens unit U4 corresponds to the 21st lens surface to the 24th lens surface. The lens configurations of the second lens unit U2, the third lens unit U3, and the fourth lens unit U4 are the same as those in the first embodiment.

  The fifth lens unit U5 corresponds to the 26th lens surface to the 35th lens surface, and includes a positive lens, a negative lens, a positive lens, a negative lens, and a positive lens in order from the object side to the image side. Numerical Example 6 satisfies the conditional expressions (1) to (5). Numerical Example 6 does not use an aspheric lens. Numerical Example 6 achieves good optical performance while achieving a high zoom ratio with a focal length of 40.00 mm at the wide-angle end and a zoom ratio of 3.00, and a reduction in size and weight of the entire system.

  FIG. 16 is a schematic diagram of a main part of an image pickup apparatus (television camera system) using the zoom lenses according to the first to sixth embodiments of the present invention as a photographing optical system. In FIG. 16, reference numeral 101 denotes a zoom lens according to any one of Examples 1 to 6. Reference numeral 124 denotes a camera. The zoom lens 101 can be attached to and detached from the camera 124. An imaging apparatus 125 is configured by attaching the zoom lens 101 to the camera 124. The zoom lens 101 includes a first group F, a zoom unit LZ, and a fifth lens group R for image formation. The first lens group F includes a focusing lens group.

  The zooming unit LZ includes a second lens group and a third lens group that move on the optical axis for zooming, and a fourth lens group that moves on the optical axis to correct image plane variation accompanying zooming. include. SP is an aperture stop. The fifth lens group R includes lens units IE ′ and IE that can be inserted and removed from the optical path. By switching the lens units IE and IE ′, the focal length range of the entire zoom lens 101 is displaced. Reference numerals 114 and 115 denote driving mechanisms such as helicoids and cams for driving the first lens unit F and the zooming portion LZ in the optical axis direction. Reference numerals 116 to 118 denote motors (drive means) that electrically drive the drive mechanisms 114 and 115 and the aperture stop SP.

  Reference numerals 119 to 121 denote detectors such as an encoder, a potentiometer, or a photosensor for detecting the positions of the first lens group F and the zooming unit LZ on the optical axis and the aperture diameter of the aperture stop SP. In the camera 124, 109 is a glass block corresponding to an optical filter or color separation optical system in the camera 124, and 110 is a solid-state imaging device (photoelectric conversion) such as a CCD sensor or a CMOS sensor that receives an object image formed by the zoom lens 101. Element). Reference numerals 111 and 122 denote CPUs that control various types of driving of the camera 124 and the zoom lens 101.

  Thus, by applying the zoom lens of the present invention to a television camera, an imaging device having high optical performance is realized.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

  Next, numerical examples 1 to 6 corresponding to the first to sixth embodiments of the present invention will be described. In each numerical example, i indicates the order of the surfaces from the object side, ri is the radius of curvature of the i-th surface from the object side, di is the i-th distance from the i-th surface from the object side, and ndi and νdi are The refractive index and Abbe number of the i-th optical member. The focal length, the F number, and the angle of view represent values when focusing on infinity. BF is the back focus, which is the distance from the final lens surface to the image plane.

The aspherical shape is expressed by the following formula, where x is the coordinate in the optical axis direction, y is the coordinate in the direction perpendicular to the optical axis, R is the reference radius of curvature, K is the conic constant, and An is the nth-order aspherical coefficient. It is represented by However, “ex” means “× 10 ^−x ”. A lens surface having an aspherical surface is marked with * on the left side of the surface number in each table.

x = (y ² / r) / {1+ (1−K · y ² / r ² ) ^0.5 } + A4 · y ⁴ + A6 · y ⁶ + A8 · y ⁸
Table 1 shows the correspondence between each embodiment and each conditional expression described above.

Numerical example 1
Unit mm

Surface data
i ri di ndi νdi effective diameter
1 * 98.922 3.00 1.77250 49.6 71.07
2 34.520 16.19 56.30
3 622.697 2.00 1.77250 49.6 54.29
4 47.162 15.60 49.88
5 -93.891 2.00 1.58913 61.1 49.92
6 -335.217 3.43 50.84
7 103.483 6.93 1.84666 23.8 54.14
8 -21659.162 5.08 54.25
9 197.856 8.61 1.49700 81.5 54.91
10 -92.408 12.03 54.87
11 178.972 2.00 1.80518 25.4 49.36
12 46.089 13.75 1.49700 81.5 47.48
13 -73.628 0.20 47.21
14 50.705 6.17 1.58913 61.1 43.01
15 376.351 (variable) 41.78
16 -285.631 1.20 1.69680 55.5 24.00
17 29.768 4.71 21.68
18 -42.443 1.20 1.49700 81.5 20.99
19 133.554 1.55 21.66
20 42.295 5.13 1.80518 25.4 22.82
21 -69.416 0.44 22.75
22 -51.981 1.20 1.88300 40.8 22.71
23 73.039 (variable) 22.86
24 164.776 1.40 1.83400 37.2 23.65
25 33.333 3.68 1.49700 81.5 24.09
26 -130.827 (variable) 24.39
27 -767.536 3.00 1.51742 52.4 25.15
28 -99.027 0.20 25.83
29 53.091 3.28 1.78800 47.4 26.70
30 146.465 (variable) 26.58
31 (Aperture) ∞ 4.81 26.71
32 71.591 8.94 1.49700 81.5 26.96
33 -49.073 6.52 26.38
34 -50.635 4.61 1.80809 22.8 23.24
35 -29.140 1.20 1.90366 31.3 23.16
36 -73.297 17.89 23.72
37 769.851 4.24 1.49700 81.5 27.01
38 -53.620 0.20 27.26
39 70.780 8.07 1.49700 81.5 26.91
40 -30.776 1.20 2.00100 29.1 26.14
41 -272.653 39.04 26.49
Image plane ∞

Aspheric data 1st surface
K = 0.00000e + 000 A 4 = 8.88027e-007 A 6 = 7.65623e-013 A 8 = 2.73179e-014

Various data Zoom ratio 2.80
Wide angle Medium Telephoto focal length 16.00 29.68 44.80
F number 2.80 2.80 2.80
Half angle of view (degrees) 43.15 26.81 18.51
Image height 15.00 15.00 15.00
Total lens length 263.54 263.54 263.54
BF 39.04 39.04 39.04

d15 2.00 24.82 34.17
d23 21.62 12.07 2.59
d26 1.10 1.68 1.10
d30 18.11 4.26 4.97

Entrance pupil position 38.27 48.82 56.46
Exit pupil position -51.86 -51.86 -51.86
Front principal point position 51.45 68.81 79.18
Rear principal point position 23.04 9.36 -5.76

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 33.95 97.00 51.95 45.56
2 16 -23.40 15.44 3.67 -7.00
3 24 -800.00 5.08 -3.64 -6.91
4 27 70.00 6.48 1.50 -2.47
5 31 67.77 57.68 13.90 -34.38

Single lens Data lens Start surface Focal length
1 1 -69.73
2 3 -65.84
3 5 -221.20
4 7 120.47
5 9 127.63
6 11 -76.90
7 12 59.13
8 14 98.39
9 16 -38.46
10 18 -64.47
11 20 33.02
12 22 -34.04
13 24 -50.03
14 25 53.69
15 27 218.41
16 29 103.54
17 32 59.89
18 34 76.69
19 35 -53.82
20 37 100.74
21 39 44.20
22 40 -34.46

Numerical example 2
Unit mm

Surface data
i ri di ndi νdi effective diameter
1 * 124.234 3.00 1.77250 49.6 76.58
2 40.427 14.06 62.55
3 252.185 2.00 1.77250 49.6 61.87
4 99.919 10.43 59.84
5 -106.522 2.00 1.72916 54.7 59.36
6 -365.973 2.81 59.79
7 87.994 4.73 1.84666 23.8 62.89
8 173.386 6.01 62.70
9 1289.383 6.92 1.49700 81.5 63.18
10 -112.937 15.65 63.34
11 188.659 2.00 1.84666 23.8 60.79
12 67.883 0.72 59.59
13 73.108 10.93 1.49700 81.5 59.70
14 -219.377 0.20 59.78
15 106.411 10.44 1.49700 81.5 59.81
16 -114.967 0.20 59.76
17 59.611 6.35 1.64000 60.1 56.30
18 147.908 (variable) 55.19
19 134.806 1.20 1.80 400 46.6 24.42
20 25.785 4.85 22.84
21 -44.380 1.20 1.72916 54.7 22.77
22 163.669 0.49 23.31
23 62.976 3.59 1.95906 17.5 23.80
24 -149.120 1.67 23.82
25 -37.280 1.20 1.80 400 46.6 23.80
26 426.445 (variable) 24.54
27 389.122 1.40 1.83400 37.2 25.71
28 44.946 4.12 1.43875 94.9 26.39
29 -84.649 (variable) 26.89
30 162.480 3.70 1.51742 52.4 28.55
31 -111.390 0.20 29.15
32 76.753 3.06 1.72916 54.7 29.91
33 401.117 (variable) 29.90
34 (Aperture) ∞ 1.29 29.95
35 30.711 5.62 1.49700 81.5 30.20
36 -534.412 13.01 29.71
37 54.500 5.55 1.80809 22.8 23.29
38 -45.153 1.20 1.90366 31.3 22.54
39 21.216 2.79 21.33
40 25.390 9.25 1.49700 81.5 23.40
41 -19.033 1.20 2.00330 28.3 23.58
42 -34.297 46.93 24.87
Image plane ∞

Aspheric data 1st surface
K = 0.00000e + 000 A 4 = 2.39488e-007 A 6 = 5.58641e-011 A 8 = -1.39473e-014

Various data Zoom ratio 4.50
Wide angle Medium Telephoto focal length 18.50 45.61 83.25
F number 2.80 2.80 2.80
Half angle of view (degrees) 39.04 18.20 10.21
Image height 15.00 15.00 15.00
Total lens length 263.78 263.78 263.78
BF 46.93 46.93 46.93

d18 1.18 33.33 43.78
d26 24.59 14.48 2.49
d29 1.10 2.07 1.09
d33 24.91 1.90 4.41

Entrance pupil position 47.55 78.59 104.52
Exit pupil position -32.39 -32.39 -32.39
Front principal point position 61.73 97.97 100.40
Rear principal point position 28.43 1.32 -36.32

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 43.70 98.45 58.77 35.91
2 19 -19.00 14.21 4.29 -5.70
3 27 -700.00 5.52 -8.52 -12.31
4 30 64.40 6.96 1.84 -2.57
5 34 73.48 39.92 -1.41 -33.77

Single lens Data lens Start surface Focal length
1 1 -78.43
2 3 -214.43
3 5 -205.85
4 7 203.76
5 9 208.67
6 11 -124.97
7 13 111.39
8 15 112.63
9 17 151.15
10 19 -39.65
11 21 -47.56
12 23 45.94
13 25 -42.37
14 27 -60.66
15 28 67.40
16 30 127.73
17 32 129.09
18 35 58.46
19 37 31.02
20 38 -15.72
21 40 23.45
22 41 -44.01

Numerical Example 3
Unit mm

Surface data
i ri di ndi νdi effective diameter
1 * 85.749 3.00 1.77250 49.6 74.65
2 36.462 14.75 60.37
3 171.789 2.00 1.77250 49.6 59.39
4 64.540 13.53 56.09
5 -71.013 2.00 1.72916 54.7 55.70
6 -140.086 1.88 56.68
7 84.787 4.55 1.84666 23.8 58.85
8 179.793 5.53 58.59
9 1137.212 6.54 1.49700 81.5 58.74
10 -113.122 15.78 58.85
11 290.054 2.00 1.84666 23.8 55.83
12 72.021 0.80 54.97
13 78.809 9.39 1.49700 81.5 55.13
14 -203.488 0.20 55.27
15 191.082 8.53 1.49700 81.5 55.10
16 -89.148 0.20 54.99
17 56.118 6.68 1.64000 60.1 53.22
18 175.966 (variable) 52.25
19 101.901 1.20 1.77250 49.6 24.65
20 29.847 5.18 23.35
21 -44.919 1.20 1.75500 52.3 23.12
22 145.527 3.36 1.95906 17.5 23.55
23 -75.550 1.25 23.74
24 -35.941 1.20 1.77250 49.6 23.72
25 -701.073 (variable) 24.47
26 222.397 1.40 1.83400 37.2 25.72
27 30.023 4.44 1.48749 70.2 26.39
28 -355.457 (variable) 26.92
29 57.085 4.35 1.59522 67.7 29.76
30 -83.397 (variable) 29.95
31 (Aperture) ∞ 1.50 30.22
32 32.211 6.51 1.49700 81.5 30.63
33 -183.588 10.02 30.02
34 38.575 4.35 1.80809 22.8 23.67
35 -439.645 1.20 1.90366 31.3 22.84
36 30.718 8.73 21.72
37 107.476 2.38 1.48749 70.2 21.99
38 -105.290 0.20 21.94
39 150.356 5.07 1.49700 81.5 21.74
40 -18.210 1.20 2.00330 28.3 21.56
41 -73.254 39.02 22.53
Image plane ∞

Aspheric data 1st surface
K = 0.00000e + 000 A 4 = 3.64518e-007 A 6 = 6.02272e-011 A 8 = 9.19409e-015

Various data Zoom ratio 4.00
Wide angle Medium Telephoto focal length 18.00 41.35 72.00
F number 2.80 2.80 2.80
Half angle of view (degrees) 39.81 19.94 11.77
Image height 15.00 15.00 15.00
Total lens length 255.00 255.00 255.00
BF 39.02 39.02 39.02

d18 1.76 33.28 44.57
d25 28.40 16.57 2.50
d28 1.09 1.96 1.69
d30 22.62 2.06 5.12

Entrance pupil position 46.47 69.88 87.73
Exit pupil position -26.51 -26.51 -26.51
Front principal point position 59.53 85.14 80.62
Rear principal point position 21.02 -2.33 -32.98

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 43.60 97.36 60.00 42.89
2 19 -22.50 13.39 4.46 -5.17
3 26 -155.00 5.84 0.57 -3.18
4 29 57.40 4.35 1.12 -1.64
5 31 67.99 41.17 -16.34 -39.69

Single lens Data lens Start surface Focal length
1 1 -83.96
2 3 -134.28
3 5 -199.10
4 7 183.61
5 9 206.77
6 11 -112.53
7 13 115.24
8 15 123.20
9 17 125.49
10 19 -54.78
11 21 -45.13
12 22 51.56
13 24 -48.84
14 26 -41.49
15 27 56.81
16 29 57.40
17 32 55.53
18 34 43.62
19 35 -31.50
20 37 109.13
21 39 32.92
22 40 -24.22

Numerical Example 4
Unit mm

Surface data
i ri di ndi νdi effective diameter
1 * 91.219 3.00 1.77250 49.6 75.04
2 40.073 10.89 62.27
3 97.159 3.00 1.77250 49.6 61.44
4 65.617 12.76 57.91
5 -88.968 2.00 1.72916 54.7 57.16
6 656.554 2.86 57.40
7 96.508 4.09 1.84666 23.8 60.20
8 181.393 4.68 60.14
9 336.602 2.00 1.80518 25.4 61.05
10 85.503 12.37 1.61800 63.3 61.51
11 -106.628 13.63 61.89
12 239.107 2.00 1.84666 23.8 61.52
13 118.043 5.96 1.49700 81.5 61.82
14 681.912 0.20 62.39
15 85.814 12.76 1.49700 81.5 64.63
16 -124.631 0.20 64.57
17 * 69.581 7.87 1.64000 60.1 61.06
18 693.184 (variable) 60.06
19 134.806 1.20 1.80 400 46.6 24.81
20 24.445 5.08 23.01
21 -44.154 1.20 1.72916 54.7 22.94
22 80.974 0.48 23.54
23 70.454 3.67 1.95906 17.5 23.88
24 -108.602 1.94 24.05
25 -31.037 1.20 1.80 400 46.6 24.04
26 -144.191 (variable) 25.10
27 198.207 1.40 1.83400 37.2 26.77
28 40.121 4.60 1.43875 94.9 27.42
29 -89.285 (variable) 27.94
30 68.382 4.20 1.51742 52.4 30.47
31 -204.192 0.20 30.82
32 -802.712 2.58 1.72916 54.7 30.95
33 -120.872 (variable) 31.18
34 (Aperture) ∞ 1.29 31.26
35 26.113 6.71 1.49700 81.5 31.52
36 217.023 12.57 30.63
37 45.182 5.95 1.80809 22.8 23.35
38 -68.908 1.20 1.90366 31.3 22.13
39 22.304 1.99 20.68
40 24.893 10.05 1.49700 81.5 21.36
41 -15.414 1.20 2.00330 28.3 21.05
42 -38.974 41.78 22.48
Image plane ∞

Aspheric data 1st surface
K = 0.00000e + 000 A 4 = 3.24352e-007 A 6 = 1.73505e-011 A 8 = 4.90876e-016

17th page
K = 0.00000e + 000 A 4 = -3.99704e-007 A 6 = -7.64184e-011 A 8 = -1.16245e-013

Various data Zoom ratio 4.80
Wide angle Medium telephoto focal length 18.50 47.42 88.80
F number 2.80 2.80 2.80
Half angle of view (degrees) 39.04 17.55 9.59
Image height 15.00 15.00 15.00
Total lens length 263.32 263.32 263.32
BF 41.78 41.78 41.78

d18 1.16 33.58 43.63
d26 25.37 15.25 2.48
d29 1.07 2.06 1.45
d33 24.92 1.64 4.97

Entrance pupil position 48.78 82.98 113.02
Exit pupil position -25.62 -25.62 -25.62
Front principal point 62.20 97.04 84.82
Rear principal point position 23.28 -5.64 -47.02

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 43.00 100.29 59.43 34.16
2 19 -18.10 14.77 3.99 -6.56
3 27 -1450.00 6.00 -17.47 -21.71
4 30 66.50 6.99 2.08 -2.44
5 34 76.80 40.96 -19.36 -41.08

Single lens Data lens Start surface Focal length
1 1 -94.50
2 3 -271.68
3 5 -106.87
4 7 235.96
5 9 -141.55
6 10 78.43
7 12 -274.76
8 13 285.39
9 15 104.06
10 17 119.78
11 19 -37.13
12 21 -38.86
13 23 44.42
14 25 -49.18
15 27 -60.18
16 28 63.63
17 30 99.08
18 32 194.00
19 35 58.86
20 37 34.23
21 38 -18.39
22 40 20.82
23 41 -25.87

Numerical Example 5
Unit mm

Surface data
i ri di ndi νdi effective diameter
1 192.136 2.50 1.77250 49.6 70.28
2 59.369 9.09 63.79
3 234.880 3.00 1.77250 49.6 63.02
4 143.510 10.28 61.59
5 -113.412 2.30 1.58913 61.1 61.00
6 -833.413 0.20 61.65
7 103.436 3.75 1.95906 17.5 62.68
8 159.639 3.59 62.27
9 329.778 2.40 1.80518 25.4 62.24
10 109.050 13.64 1.58913 61.1 61.90
11 -109.484 17.77 62.08
12 87.728 2.30 1.80518 25.4 55.61
13 59.793 10.86 1.43875 94.9 53.91
14 -155.207 0.20 53.37
15 59.764 5.98 1.64000 60.1 49.23
16 183.548 (variable) 47.75
17 41.233 1.30 1.77250 49.6 28.35
18 23.321 7.83 25.62
19 -58.724 1.20 1.58913 61.1 23.23
20 54.343 1.00 22.74
21 34.867 3.21 1.84666 23.8 23.36
22 223.126 2.06 23.14
23 -43.679 1.30 1.69680 55.5 23.10
24 83.687 (variable) 23.52
25 57.718 2.00 2.00330 28.3 25.03
26 49.633 (variable) 24.95
27 659.667 3.60 1.43875 94.9 26.11
28 -61.618 0.20 26.77
29 93.503 2.87 1.58913 61.1 27.50
30 -272.339 (variable) 27.59
31 (Aperture) ∞ 1.80 27.66
32 38.472 3.84 1.59201 67.0 27.80
33 305.682 14.00 27.39
34 87.462 1.94 1.72825 28.5 22.06
35 24.874 1.82 20.92
36 24.150 2.00 1.65412 39.7 22.35
37 25.531 3.44 22.27
38 48.055 5.00 1.43875 94.9 23.77
39 -198.239 7.13 24.56
40 70.368 4.00 1.43875 94.9 27.29
41 -154.395 49.81 27.47
Image plane ∞

Various data Zoom ratio 3.30
Wide angle Medium Tele focal length 28.00 57.32 92.40
F number 2.80 2.80 2.80
Half angle of view (degrees) 28.18 14.67 9.22
Image height 15.00 15.00 15.00
Total lens length 259.88 259.88 259.88
BF 49.81 49.81 49.81

d16 0.98 30.88 42.20
d24 25.10 12.75 1.00
d26 2.62 4.97 5.39
d30 21.96 2.05 2.07

Entrance pupil position 63.52 106.36 136.70
Exit pupil position -57.87 -57.87 -57.87
Front principal point position 84.24 133.17 149.81
Rear principal point position 21.81 -7.51 -42.59

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 66.30 87.86 62.71 26.31
2 17 -23.40 17.89 8.45 -5.14
3 25 -400.00 2.00 8.11 6.97
4 27 61.70 6.68 2.75 -1.77
5 31 72.72 44.98 21.42 -27.50

Single lens Data lens Start surface Focal length
1 1 -111.61
2 3 -482.20
3 5 -222.23
4 7 292.67
5 9 -201.47
6 10 94.57
7 12 -239.92
8 13 99.67
9 15 135.36
10 17 -71.43
11 19 -47.53
12 21 47.95
13 23 -40.84
14 25 -400.00
15 27 128.32
16 29 118.04
17 32 73.68
18 34 -47.97
19 36 430.85
20 38 88.49
21 40 110.49

Numerical Example 6
Unit mm

Surface data
i ri di ndi νdi effective diameter
1 -143.213 2.50 1.77250 49.6 52.95
2 186.153 6.00 52.70
3 -205.371 6.50 1.48749 70.2 53.10
4 -66.506 11.36 53.63
5 90.339 7.00 1.58913 61.1 52.29
6 -300.617 0.50 51.73
7 52.217 2.80 1.84666 23.8 47.63
8 40.377 7.16 1.48749 70.2 45.25
9 145.645 (variable) 44.41
10 2461.812 1.40 1.77250 49.6 24.50
11 32.489 4.86 23.51
12 -43.283 1.40 1.58913 61.1 23.62
13 88.312 3.00 24.69
14 78.426 2.79 1.95906 17.5 26.78
15 2336.903 2.32 26.99
16 -44.980 1.40 1.77250 49.6 27.05
17 -59.321 (variable) 27.82
18 -122.036 2.00 1.88300 40.8 28.86
19 82.387 4.52 1.48749 70.2 30.19
20 -57.901 (variable) 30.72
21 512.777 3.38 1.43875 94.9 32.51
22 -84.839 0.20 32.99
23 118.502 3.00 1.58913 61.1 33.85
24 32581.268 (variable) 33.98
25 (Aperture) ∞ 4.00 34.18
26 40.739 5.39 1.59201 67.0 35.06
27 194.526 23.32 34.45
28 45.667 2.00 1.65412 39.7 28.51
29 30.415 6.89 27.74
30 61.827 5.43 1.43875 94.9 29.09
31 -76.005 5.69 29.14
32 -27.687 1.20 1.78472 25.7 28.72
33 -43.923 0.20 29.88
34 -69.759 5.89 1.58913 61.1 30.15
35 -38.592 56.51 31.44
Image plane ∞

Various data Zoom ratio 3.00
Wide angle Medium Telephoto focal length 40.00 77.33 120.00
F number 2.80 2.79 2.80
Half angle of view (degrees) 20.56 10.98 7.13
Image height 15.00 15.00 15.00
Total lens length 237.52 237.52 237.52
BF 56.51 56.51 56.51

d 9 1.49 29.85 41.93
d17 24.84 12.53 1.93
d20 0.10 2.30 1.00
d24 20.47 2.22 2.05

Entrance pupil position 56.76 118.76 165.03
Exit pupil position -73.31 -73.31 -73.31
Front principal point position 84.44 150.03 174.11
Rear principal point position 16.51 -20.82 -63.49

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 89.60 43.82 31.59 3.26
2 10 -27.50 17.17 1.83 -12.29
3 18 -300.00 6.52 -8.88 -13.38
4 21 91.00 6.58 2.26 -2.18
5 25 78.62 60.01 21.71 -43.31

Single lens Data lens Start surface Focal length
1 1 -103.93
2 3 198.04
3 5 118.24
4 7 -233.76
5 8 111.71
6 10 -42.43
7 12 -48.92
8 14 83.45
9 16 -250.39
10 18 -55.12
11 19 70.26
12 21 165.78
13 23 201.09
14 26 85.62
15 28 -145.99
16 30 78.46
17 32 -97.77
18 34 136.46

U1: First lens group U2: Second lens group U3: Third lens group U4: Fourth lens group U5: Fifth lens group

Claims (8)

For zooming, in order from the object side to the image side, a first lens unit having a fixed positive refractive power, a second lens unit having a negative refractive power that moves upon zooming, and a negative lens power that moves upon zooming. In a zoom lens having a third lens group, a fourth lens group with positive refractive power that moves upon zooming, and a fifth lens group with positive refractive power that does not move for zooming,
The focal length of the first lens group is f1, the focal length of the second lens group is f2, the focal length of the third lens group is f3, the focal length of the fourth lens group is f4, and the fourth lens at the wide angle end. When the imaging magnification of the lens group is β4w,
−3.5 <f1 / f2 <−1.0
−0.40 <f4 / f3 <−0.01
−0.50 <f1 / f3 <−0.01
| 1 / β4w | <0.5
A zoom lens satisfying the following conditional expression: The distance between the third lens group and the fourth lens group at the wide angle end is L3w, the focal length of the entire system at the wide angle end is fw, and the zoom ratio is Z.
fm = fw × Z ^0.6
When the distance between the third lens group and the fourth lens group at the zoom position where the focal length fm satisfies is L3m,
0.01 <L3w / L3m <1.10
The zoom lens according to claim 1, wherein the following conditional expression is satisfied.   3. The zoom lens according to claim 1, wherein the third lens group takes a zoom locus located closest to the object side at a wide-angle end during zooming.   4. The zoom lens according to claim 1, wherein the third lens group includes one or more negative lenses and one or more positive lenses. 5.   In zooming from the wide-angle end to the telephoto end, the second lens group moves toward the image side, and the third lens group and the fourth lens group move along a convex locus toward the image side. Item 5. The zoom lens according to any one of Items 1 to 4.   The zoom lens according to claim 1, wherein the second lens group includes two negative lenses, a positive lens, and a negative lens in order from the object side to the image side.   The zoom lens according to any one of claims 1 to 6, wherein the fourth lens group includes one positive lens or two positive lenses.   An imaging apparatus comprising: the zoom lens according to claim 1; and a solid-state imaging device that receives an image formed by the zoom lens.