U.S. patent application number 13/089381 was filed with the patent office on 2012-05-03 for zoom lens and photographing apparatus having the same.
This patent application is currently assigned to Samsung Electronics Co., Ltd.. Invention is credited to Jin-woo Kim.
Application Number | 20120105976 13/089381 |
Document ID | / |
Family ID | 45931405 |
Filed Date | 2012-05-03 |
United States Patent
Application |
20120105976 |
Kind Code |
A1 |
Kim; Jin-woo |
May 3, 2012 |
ZOOM LENS AND PHOTOGRAPHING APPARATUS HAVING THE SAME
Abstract
A zoom lens and a photographing apparatus having the zoom lens
including a first lens group having a positive refractive power; a
second lens group having a negative refractive power; a third lens
group having a positive refractive power; and a fourth lens group
having a positive refractive power, wherein the first lens group,
the second lens group, the third lens group, and the fourth lens
group are arranged sequentially from an object side, wherein the
second lens group includes a first aspherical lens having a
negative refractive power, and a second aspherical lens having a
positive refractive power.
Inventors: |
Kim; Jin-woo; (Suwon-si,
KR) |
Assignee: |
Samsung Electronics Co.,
Ltd.
Suwon-si
KR
|
Family ID: |
45931405 |
Appl. No.: |
13/089381 |
Filed: |
April 19, 2011 |
Current U.S.
Class: |
359/687 |
Current CPC
Class: |
G02B 15/144113 20190801;
G02B 15/173 20130101 |
Class at
Publication: |
359/687 |
International
Class: |
G02B 15/14 20060101
G02B015/14 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 27, 2010 |
KR |
10-2010-0105388 |
Claims
1. A zoom lens comprising: a first lens group having a positive
refractive power; a second lens group having a negative refractive
power; a third lens group having a positive refractive power; and a
fourth lens group having a positive refractive power, wherein the
first lens group, the second lens group, the third lens group, and
the fourth lens group are arranged sequentially from an object
side, wherein the second lens group comprises a first aspherical
lens having a negative refractive power, and a second aspherical
lens having a positive refractive power, and satisfies the
inequalities 1.4.ltoreq.wfno.ltoreq.2.5 2.ltoreq.tf/wf.ltoreq.5,
where wfno is the minimum F-number (FNO) at the wide-angle
position, tf is the focal length of the zoom lens at the telephoto
position, and wf is the focal length of the zoom lens at the
wide-angle position.
2. The zoom lens of claim 1, wherein at least one of the first
aspherical lens and the second aspherical lens comprised in the
second lens group satisfies the inequality 2.0.ltoreq.nd.sub.2,
where nd.sub.2 is the refractive index of an aspherical lens
comprised in the second lens group.
3. The zoom lens of claim 2, wherein the third lens group comprises
at least four lenses.
4. The zoom lens of claim 1, wherein distances between the first,
second, third, and fourth lens groups vary during zooming.
5. The zoom lens of claim 1, wherein the third lens group comprises
at least one lens that satisfies the inequality 70.ltoreq.Vd.sub.3,
where Vd.sub.3 is an Abbe number of the at least one lens comprised
in the third lens group.
6. The zoom lens of claim 1, wherein the zoom lens satisfies the
inequality 76.degree..ltoreq.wfov.ltoreq.93.degree., where wfov is
the field of view (FOV) of the zoom lens at the wide-angle
position.
7. The zoom lens of claim 1, wherein the zoom lens satisfies the
inequality 0.ltoreq.tfno-wfno.ltoreq.1.3, where wfno is the minimum
FNO of the zoom lens at the wide-angle position, and tfno is the
minimum FNO of the zoom lens at the telephoto position.
8. The zoom lens of claim 1, wherein the first lens group comprises
at least one lens that satisfies the inequality
1.9.ltoreq.nd.sub.1, where nd.sub.1 is the refractive index of the
at least one lens comprised in the first lens group.
9. The zoom lens of claim 1, wherein the third lens group comprises
at least one aspherical lens having a positive refractive
power.
10. The zoom lens of claim 1, wherein the fourth lens group
comprises at least one aspherical lens having a positive refractive
power.
11. The zoom lens of claim 1, wherein the fourth lens group
comprises a meniscus lens having a convex surface toward the object
side.
12. The zoom lens of claim 1, wherein the first lens group
comprises at least one doublet lens consisting of a positive lens
and a negative lens.
13. The zoom lens of claim 1, wherein the third lens group
comprises at least one doublet lens consisting of a positive lens
and a negative lens.
14. The zoom lens of claim 1, wherein the third lens group moves in
a direction perpendicular to the optical axis so as to perform
hand-shaking compensation.
15. The zoom lens of claim 1, wherein the fourth lens group
performs focusing.
16. The zoom lens of claim 1, wherein the second lens group further
comprises a third lens having a negative refractive power between
the first aspherical lens and the second aspherical lens.
17. The zoom lens of claim 1, wherein the third lens group
comprises a third lens having a positive refractive power, a fourth
lens having a positive refractive power, a fifth lens having a
negative refractive power, and a sixth lens having a positive
refractive power.
18. The zoom lens of claim 1, wherein the third lens group
comprises an aperture stop.
19. The zoom lens of claim 1, wherein the first lens group, the
second lens group, the third lens group, and the fourth lens group
respectively move during zooming.
20. A photographing apparatus comprising: a zoom lens; and an
imaging device receiving light from an image formed by the zoom
lens, wherein the zoom lens comprises: a first lens group having a
positive refractive power; a second lens group having a negative
refractive power; a third lens group having a positive refractive
power; and a fourth lens group having a positive refractive power,
wherein the first lens group, the second lens group, the third lens
group, and the fourth lens group are arranged sequentially from an
object side, wherein the second lens group comprises a first
aspherical lens having a negative refractive power, and a second
aspherical lens having a positive refractive power, and satisfies
the inequalities 1.4.ltoreq.wfno.ltoreq.2.5
2.ltoreq.tf/wf.ltoreq.5, where wfno is the minimum F-number (FNO)
at the wide-angle position, tf is the focal length of the zoom lens
at the telephoto position, and wf is the focal length of the zoom
lens at the wide-angle position.
Description
CROSS-REFERENCE TO RELATED PATENT APPLICATION
[0001] This application claims the benefit of Korean Patent
Application No. 10-2010-0105388, filed on Oct. 27, 2010, in the
Korean Intellectual Property Office, the disclosure of which is
incorporated herein in its entirety by reference.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The present disclosure relates to a wide angle zoom lens and
a photographing apparatus having the same.
[0004] 2. Description of the Related Art
[0005] With respect to optical systems including digital cameras,
interchangeable lens systems, video cameras, or similar apparatuses
which use a solid-state imaging device such as a charge coupled
device (CCD), users require not only high resolution devices but
also devices having a wide angle of view and high magnification
function. Also, nowadays, many users have become highly proficient
in using such devices. Accordingly, it is necessary to develop a
lens system having a wide angle of view, high magnification, and a
low F-number (FNO) in order to achieve high brightness. Some zoom
lenses only have a wide angle of view or high magnification, or
other zoom lenses have a low FNO and high brightness but include an
optical system with a fixed focal length or have a complicated lens
structure causing size and weight problems.
SUMMARY
[0006] Provided is a zoom lens having a wide angle of view, high
magnification, and a low F-number (FNO).
[0007] According to an embodiment of the invention, there is
provided a zoom lens including a first lens group having a positive
refractive power; a second lens group having a negative refractive
power; a third lens group having a positive refractive power; and a
fourth lens group having a positive refractive power, wherein the
first lens group, the second lens group, the third lens group, and
the fourth lens group are arranged sequentially from an object
side, wherein the second lens group includes a first aspherical
lens having a negative refractive power, and a second aspherical
lens having a positive refractive power, and satisfies the
inequalities
1.4.ltoreq.wfno.ltoreq.2.5
2.ltoreq.tf/wf.ltoreq.5,
where wfno is the minimum F-number (FNO) at the wide-angle
position, tf is the focal length of the zoom lens at the telephoto
position, and wf is the focal length of the zoom lens at the
wide-angle position.
[0008] At least one of the first aspherical lens and the second
aspherical lens included in the second lens group may satisfy the
inequality
2.0.ltoreq.nd.sub.2,
where nd.sub.2 is the refractive index of an aspherical lens
included in the second lens group.
[0009] The third lens group may include at least four lenses.
[0010] Distances between the first, second, third, and fourth lens
groups may vary during zooming.
[0011] The third lens group may include at least one lens that
satisfies the inequality
70.ltoreq.Vd.sub.3,
where Vd.sub.3 is an Abbe number of the at least one lens included
in the third lens group.
[0012] The zoom lens may satisfy the inequality
76.degree..ltoreq.wfov.ltoreq.93.degree.,
where wfov is the field of view (FOV) of the zoom lens at the
wide-angle position.
[0013] The zoom lens may satisfy the inequality
0.ltoreq.tfno-wfno.ltoreq.1.3,
where wfno is the minimum FNO of the zoom lens at the wide-angle
position, and tfno is the minimum FNO of the zoom lens at the
telephoto position.
[0014] The first lens group may include at least one lens that
satisfies the inequality
1.9.ltoreq.nd.sub.1,
where nd.sub.1 is the refractive index of the at least one lens
included in the first lens group.
[0015] The third lens group may include at least one aspherical
lens having a positive refractive power.
[0016] The fourth lens group may include at least one aspherical
lens having a positive refractive power.
[0017] The fourth lens group may include a meniscus lens having a
convex surface toward the object side.
[0018] The first lens group may include at least one doublet lens
consisting of a positive lens and a negative lens.
[0019] The third lens group may include at least one doublet lens
consisting of a positive lens and a negative lens.
[0020] The third lens group may move in a direction perpendicular
to an optical axis so as to perform hand-shaking compensation.
[0021] The fourth lens group may perform focusing.
[0022] The second lens group may further include a third lens
having a negative refractive power between the first aspherical
lens and the second aspherical lens.
[0023] The third lens group may include a third lens having a
positive refractive power, a fourth lens having a positive
refractive power, a fifth lens having a negative refractive power,
and a sixth lens having a positive refractive power.
[0024] The third lens group may include an aperture stop.
[0025] The first lens group, the second lens group, the third lens
group, and the fourth lens groups may independently move during
zooming.
[0026] According to another embodiment of the invention, there is
provided a photographing apparatus including a zoom lens; and an
imaging device receiving light from an image formed by the zoom
lens, wherein the zoom lens includes a first lens group having a
positive refractive power; a second lens group having a negative
refractive power; a third lens group having a positive refractive
power; and a fourth lens group having a positive refractive power,
wherein the first lens group, the second lens group, the third lens
group, and the fourth lens group are arranged sequentially from an
object side, wherein the second lens group includes a first
aspherical lens having a negative refractive power, and a second
aspherical lens having a positive refractive power, and satisfies
the inequalities
1.4.ltoreq.wfno.ltoreq.2.5
2.ltoreq.tf/wf.ltoreq.5,
where wfno is the minimum F-number (FNO) at the wide-angle
position, tf is the focal length of the zoom lens at the telephoto
position, and wf is the focal length of the zoom lens at the
wide-angle position.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The above and other features and advantages will become more
apparent by describing in detail exemplary embodiments thereof with
reference to the attached drawings in which:
[0028] FIG. 1 illustrates a zoom lens according to a first
embodiment of the invention;
[0029] FIG. 2A illustrates longitudinal spherical aberration,
astigmatic field curves, and distortion of the zoom lens of FIG. 1
at the wide-angle position;
[0030] FIG. 2B illustrates longitudinal spherical aberration,
astigmatic field curves, and distortion of the zoom lens of FIG. 1
at the telephoto position;
[0031] FIG. 3 illustrates a zoom lens according to a second
embodiment of the invention;
[0032] FIG. 4A illustrates longitudinal spherical aberration,
astigmatic field curves, and distortion of the zoom lens of FIG. 3
at the wide-angle position;
[0033] FIG. 4B illustrates longitudinal spherical aberration,
astigmatic field curves, and distortion of the zoom lens of FIG. 3
at the telephoto position;
[0034] FIG. 5 illustrates a zoom lens according to a third
embodiment of the invention;
[0035] FIG. 6A illustrates longitudinal spherical aberration,
astigmatic field curves, and distortion of the zoom lens of FIG. 5
at the wide-angle position;
[0036] FIG. 6B illustrates longitudinal spherical aberration,
astigmatic field curves, and distortion of the zoom lens of FIG. 5
at the telephoto position;
[0037] FIG. 7 illustrates a zoom lens according to a fourth
embodiment of the invention;
[0038] FIG. 8A illustrates longitudinal spherical aberration,
astigmatic field curves, and distortion of the zoom lens of FIG. 7
at the wide-angle position;
[0039] FIG. 8B illustrates longitudinal spherical aberration,
astigmatic field curves, and distortion of the zoom lens of FIG. 7
at the telephoto position; and
[0040] FIG. 9 is a diagram of a photographing apparatus according
to another embodiment of the invention.
DETAILED DESCRIPTION
[0041] Reference will now be made in detail to embodiments of a
zoom lens and a photographing apparatus having the same, examples
of which are illustrated in the accompanying drawings, wherein like
reference numerals refer to the like elements throughout, and the
size of each component may be exaggerated for clarity. In this
regard, the present embodiments may have different forms and should
not be construed as being limited to the descriptions set forth
herein.
[0042] Referring to FIG. 1, a zoom lens 111 may include a first
lens group G1 having a positive refractive power, a second lens
group G2 having a negative refractive power, a third lens group G3
having a positive refractive power, and a fourth lens group G4
having a positive refractive power, which are arranged sequentially
from an object side O. Distances between the aforementioned lens
groups of the zoom lens 111 may vary during zooming. When the zoom
lens 111 is zoomed, zoom magnification and the angle of view may
vary. The first lens group G1 includes a first lens 1 having a
negative refractive power, and a second lens 2 having a positive
refractive power, and may control chromatic aberration. The first
lens group G1 may include at least one doublet lens consisting of a
positive lens and a negative lens. For example, the first lens 1
and the second lens 2 may be cemented together. Accordingly, the
first lens group G1 may easily control the chromatic aberration,
and also may have a simple manufacturing structure.
[0043] The second lens group G2 includes an aspherical lens having
a negative refractive power, and an aspherical lens having a
positive refractive power, and may control chromatic aberration
along an off-axis. For example, the second lens group G2 may
include a third lens 3 having a negative refractive power, a fourth
lens 4 having a negative refractive power, and a fifth lens 5
having a positive refractive power. For example, the third lens 3
and the fifth lens 5 may be aspherical lenses.
[0044] The zoom lens 111 may satisfy Inequalities 1 and 2
below.
1.4.ltoreq.wfno.ltoreq.2.5 <Inequality 1>
2.ltoreq.tf/wf.ltoreq.5 <Inequality 2>
where wfno is the minimum FNO at the wide-angle position, tf is the
focal length of the zoom lens at the telephoto position, and wf is
the focal length of the zoom lens at the wide-angle position. The
zoom lens 111 having a low FNO, high brightness, and high zoom
magnification may satisfy various customers' requirements.
[0045] At least one of the aspherical lenses included in the second
lens group G2 may satisfy Inequality 3 below.
2.0.ltoreq.nd.sub.2 <Inequality 3>
where nd.sub.2 is the refractive index of the one of the aspherical
lenses included in the second lens group G2.
[0046] Since the second lens group G2 employs a high refraction
aspherical lens having a refractive index equal to or greater than
2.0, the second lens group G2 may appropriately control the
chromatic aberration along the off-axis.
[0047] The third lens group G3 may include at least 4 lenses. For
example, the third lens group G3 may include a sixth lens 6, a
seventh lens 7, an eighth lens 8, and a ninth lens 9. The sixth
lens 6 may have a positive refractive power, the seventh lens 7 may
have a positive refractive power, the eighth lens 8 may have a
negative refractive power, and the ninth lens 9 may have a positive
refractive power. The third lens group G3 may include an aspherical
lens having a positive refractive power. For example, the sixth
lens 6 may be an aspherical lens. Since the third lens group G3
includes 4 lenses, the third lens group G3 may control the
spherical aberration and chromatic aberration due to a large
aperture. The third lens group G3 may correct the chromatic
aberration by including a doublet lens consisting of a positive
lens and a negative lens. The third lens group G3 may have an
aperture stop ST adjacent to the object side O of the third lens
group G3. By allowing the third lens group G3 to have 4 lenses
respectively having positive, positive, negative, and positive
refractive powers, it is possible to realize a wide angle of view
and high magnification. Also, since the stop ST of the third lens
group G3 is adjacent to the object side O of the third lens group
G3, it is possible to control the spherical aberration due to the
large aperture. In the third lens group G3, a lens adjacent to the
stop ST, e.g., the sixth lens 6, may be an aspherical lens, and
thus, the spherical aberration may be easily corrected. Also, since
the third lens group G3 and the stop ST have the same locus during
zooming, a change of an FNO may be minimized although the zoom lens
111 is zoomed from the wide-angle position to the telephoto
position.
[0048] The third lens group G3 may move in a direction
perpendicular to the optical axis so as to perform hand-shaking
compensation. For a good image, the third lens group G3 corrects
the spherical aberration and Petzval sum during a lens shift for
hand-shaking compensation. Thus, occurrence of eccentric coma at
the center of a screen when the spherical aberration and a shift
lens group move in a direction perpendicular to the optical axis
may be avoided. Also, by correcting the Petzval sum, occurrence of
a field curvature at the periphery of the screen when the shift
lens group moves in the direction perpendicular to the optical axis
may be avoided.
[0049] The fourth lens group G4 may include a tenth lens 10. For
example, the fourth lens group G4 may include only one lens.
[0050] The distances between the first through fourth lens groups
G1 through G4 of the zoom lens 111 may vary during zooming. For
example, when the zoom lens 111 is zoomed from the wide-angle
position to the telephoto position, the distance between the first
lens group G1 and the second lens group G2 may increase, the
distance between the second lens group G2 and the third lens group
G3 may decrease, and the distance between the third lens group G3
and the fourth lens group G4 may increase. During zooming, each of
the first through fourth lens groups G1 through G4 may move. The
fourth lens group G4 may perform focusing by adjusting a position
of an image plane during zooming. Also, since the tenth lens 10 of
the fourth lens group G4 may be an aspherical lens, the fourth lens
group G4 may control aberration along on an off-axis. The tenth
lens 10 may have a positive refractive power. Also, the tenth lens
10 may be a meniscus lens having a convex surface toward the object
side O. Thus, the fourth lens group G4 may easily correct field
curvature and may reduce an aberration change according to an
object distance during focusing.
[0051] Meanwhile, in order to achieve an ultra wide angle of view,
large aperture, and high magnification, it is necessary to
appropriately control aberration. In this regard, aberration along
on the off-axis may be appropriately controlled by using in the
second lens group G2 to employ the high refraction aspherical lens
having a refractive index equal to or greater than 2.0, so that a
good optical feature may be realized. The zoom lens 111 may be
embodied as a high functional zoom lens having an ultra wide angle
of view, large aperture, and high magnification.
[0052] At least one of lenses included in the third lens group G3
may satisfy Inequality 4 below.
70.ltoreq.Vd.sub.3 <Inequality 4>
where Vd.sub.3 is an Abbe number of at least one lens included in
the third lens group G3. Since the third lens group G3 includes at
least one lens formed of a material having an Abbe number equal to
or greater than 70, chromatic aberration due to short-wavelength
light may be easily controlled.
[0053] The zoom lens 111 may satisfy Inequality 5 below.
76.degree..ltoreq.wfov.ltoreq.93.degree. <Inequality 5>
where wfov is the field of view (FOV) of the zoom lens 111 at the
wide-angle position.
[0054] Since the zoom lens 111 has a wide angle of view equal to or
greater than 76 degrees, it is possible to photograph indoors the
entire shape of a target object or to photograph a broad outdoor
landscape.
[0055] The zoom lens 111 may satisfy Inequality 6 below.
0.ltoreq.tfno-wfno.ltoreq.1.3 <Inequality 6>
where wfno is the minimum FNO of the zoom lens 111 at the
wide-angle position, and tfno is the minimum FNO of the zoom lens
111 at the telephoto position. If the difference between the
minimum FNO at the telephoto position and the minimum FNO at the
wide-angle position is small, the difference between lens
brightness values due to zooming is small, and thus, a shutter
speed may not significantly vary. That is, since the zoom lens 111
may have a low FNO and high brightness even at the telephoto
position, it is not necessary to increase the shutter speed at the
telephoto position, and out-focusing at the telephoto position may
be further easily performed.
[0056] At least one of the lenses included in the first lens group
G1 may satisfy Inequality 7 below.
1.9.ltoreq.nd.sub.1 <Inequality 7>
where nd.sub.1 is the refractive index of at least one lens
included in the first lens group G1. For example, a positive lens
of the first lens group G1 may have a refractive index equal to or
greater than 1.9, and thus, a wide angle of view may be realized
with a high refractive power. If Inequality 7 is not satisfied, low
marginal illumination and distortion may occur, and a radius of
curvature of the at least one lens of the first lens group G1 may
be reduced or a thickness of the at least one lens of the first
lens group G1 may be increased.
[0057] An aspherical surface used in the zoom lens 111 according to
the present embodiment may be defined below.
[0058] When an X-axis is the optical axis direction, and a Y-axis
is a direction perpendicular to the optical axis direction, an
aspherical shape may be expressed by Equation 8 below, and a travel
direction of rays may be regarded as being positive. Here, x is the
distance from the lens apex in the optical axis direction, y is the
distance in the direction perpendicular to the optical axis
direction, K is a conic constant, A, B, C, and D are aspherical
coefficients, and c is the reciprocal (1/R) of the radius of
curvature at the lens apex.
x = cy 2 1 + 1 - ( K + 1 ) c 2 y 2 + Ay 4 + By 6 + Cy 8 + Dy 10 .
< Equation 8 > ##EQU00001##
[0059] According to one or more embodiments of the invention, the
zoom lens 111 may vary according to various design changes.
Hereinafter, f in the unit of mm is the total focal length, Fno is
an F-number, and 2.omega. is the field of view (FOV) and is
expressed by using the unit of degree. In respective drawings
illustrating respective embodiments, at least one filter 11 may be
arranged at a side that is the closest to an image I. Also, in the
drawings, IMG is an image plane.
First Embodiment
[0060] FIG. 1 illustrates a zoom lens according to a first
embodiment of the invention, and Table 1 shows design data related
to the first embodiment. Although reference numerals of lens
surfaces in each lens are indicated in FIG. 1, reference numerals
of lens surfaces will be omitted in other drawings related to other
embodiments.
TABLE-US-00001 TABLE 1 Lens Radius of Refractive Abbe surface
curvature Thickness index (nd) number (vd) S1 31.343 0.90 1.946
17.98 S2 23.646 4.14 1.789 45.61 S3 160.170 D1 S4* 719.821 1.00
1.805 40.90 S5* 9.466 4.04 S6 -75.100 0.55 1.586 58.65 S7 19.358
0.20 S8* 15.988 1.92 2.003 19.32 S9* 39.523 D2 ST infinity 0.60
S11* 8.088 2.60 1.740 48.50 S12* -39.767 0.20 S13 6.900 1.62 1.497
81.61 S14 -63.726 0.45 1.750 28.56 S15 4.671 0.61 S16 5.892 1.21
1.497 81.61 S17 6.644 D3 S18* 9.904 1.80 1.805 40.90 S19* 23.507 D4
S20 infinity 0.30 1.517 64.17 S21 infinity 0.80 S22 infinity 0.50
1.517 64.17 S23 infinity D5 S24 infinity D6 f; 6~17.22~30 Fno;
2.28~2.72~3.05 2.omega.; 85.79~29.88~17.15
In Table 1, the mark * indicates an aspherical surface. Table 2
below shows aspherical coefficients in the first embodiment.
TABLE-US-00002 TABLE 2 Lens surface K A B C D S4 1.000000
1.664444E-04 -2.371357E-06 1.603213E-08 -4.680978E-11 S5 -0.166484
2.291352E-04 2.753647E-06 -5.747884E-08 4.466989E-10 S8 -1.859206
-4.630884E-05 8.171250E-07 -5.878735E-08 0.000000E+00 S9 -47.086037
-3.510542E -05 -7.585544E-07 -4.034663E-08 0.000000E+00 S11
-0.086866 -1.401896E-04 -1.224639E-06 -6.108613E-08 0.000000E+00 12
23.413263 1.161945E-04 -1.742791E-06 7.239738E-09 0.000000E+00 18
-0.479564 -1.480732E-04 2.808527E-06 1.075303E-07 0.000000E+00 19
-8.093263 -3.068999E-05 6.520253E-07 1.700179E-07 0.000000E+00
[0061] Table 3 below shows variable distances of the first
embodiment during zooming.
TABLE-US-00003 TABLE 3 Wide-angle Middle Telephoto position
position position D1 0.50 15.10 21.46 D2 20.98 5.68 0.50 D3 4.50
5.95 8.61 D4 2.47 4.46 4.52 D5 0.60 0.60 0.60 D6 0.00 0.01 0.01
[0062] FIGS. 2A and 2B illustrate longitudinal spherical
aberration, astigmatic field curves, and distortion of the zoom
lens according to the first embodiment at the wide-angle position
and the telephoto position. The tangential field curvature T and
sagittal field curvature S are shown as the astigmatic field
becomes curved.
Second Embodiment
[0063] FIG. 3 illustrates a zoom lens according to a second
embodiment of the invention, and Table 4 shows design data related
to the second embodiment.
TABLE-US-00004 TABLE 4 Lens Radius of Thick- Refractive Abbe
surface curvature ness index (nd) number (vd) S1 32.578 0.90 1.946
17.98 S2 23.714 4.89 1.836 37.77 S3 109.519 D1 S4* 200.000 1.00
1.805 40.90 S5* 7.212 5.26 S6 -10.889 0.71 1.772 49.66 S7 -44.569
0.20 S8* 343.756 1.64 2.003 19.32 S9* -23.248 D2 ST infinity 0.30
S11* 7.913 3.83 1.740 48.50 S12* -101.570 0.51 S13 11.865 1.26
1.497 81.61 S14 22.377 0.50 1.926 21.15 S15 6.054 0.84 S16 11.742
2.04 1.601 60.92 S17 -57.346 D3 S18* 12.586 1.79 1.805 40.90 S19
26.009 D4 S20 infinity 0.30 1.517 64.17 S21 infinity 0.30 S22
infinity 0.50 1.517 64.17 S23 infinity D5 S24 infinity D6 f;
5.36~10.99~18.19 Fno; 1.43~1.83~2.00 2.omega.;
89.41~46.38~28.16
[0064] Table 5 below shows aspherical coefficients in the second
embodiment.
TABLE-US-00005 TABLE 5 Lens surface K A B C D S4 1.000000
1.479285E-04 -1.970853E-06 2.044097E-08 -9.124265E-11 S5 0.181270
-3.869616E-05 3.430784E-07 -4.665099E-08 3.553906E-10 S8
-3797.713978 1.177174E-05 -8.816590E-08 0.000000E+00 0.000000E+00
S9 0.134778 -6.340815E-06 -3.513681E-07 0.000000E+00 0.000000E+00
S11 -0.202883 -1.556795E-04 1.844260E-07 -3.388733E-08 0.000000E+00
S12 12.413680 7.877404E-05 7.257034E-08 -1.450599E-08 0.000000E+00
S18 -0.687104 -7.195686E-05 2.816108E-06 -1.862266E-08
0.000000E+00
[0065] Table 6 below shows variable distances of the second
embodiment during zooming.
TABLE-US-00006 TABLE 6 Variable Wide-angle Middle Telephoto
distances position position position D1 0.70 7.95 19.08 D2 14.58
3.92 1.55 D3 4.71 6.27 8.26 D4 3.00 5.33 5.09 D5 0.60 0.60 0.60 D6
0.00 0.01 0.03
[0066] FIGS. 4A and 4B illustrate longitudinal spherical
aberration, astigmatic field curves, and distortion of the zoom
lens according to the second embodiment at the wide-angle position
and the telephoto position.
Third Embodiment
[0067] FIG. 5 illustrates a zoom lens according to a third
embodiment of the invention, and Table 7 shows design data related
to the second embodiment.
TABLE-US-00007 TABLE 7 Lens Radius of Thick- Refractive Abbe
surface curvature ness index (nd) number (vd) S1 24.643 0.90 1.946
17.98 S2 18.794 4.18 1.786 44.30 S3 117.085 D1 S4* 90.927 1.10
1.805 40.90 S5* 6.165 4.99 S6 -20.837 0.60 1.727 51.90 S7 38.592
0.30 S8 21.163 2.30 2.003 19.32 S9* 69300.333 D2 ST infinity 0.60
S11* 8.660 2.22 1.761 50.15 S12* -20.436 0.83 S13 15.410 1.66 1.487
70.40 S14 -30.421 0.50 84.051 24.06 S15 7.320 1.13 S16 -15.150 1.61
1.487 70.40 S17 -7.005 D3 S18* 9.167 2.60 1.621 59.93 S19 21.063 D4
S20 infinity 0.30 1.517 64.17 S21 infinity 0.30 S22 infinity 0.50
1.517 64.17 S23 infinity D5 S24 infinity D6 f; 6.00~10.33~16.18
Fno; 1.90~2.14~2.4 2.omega.; 79.48~48.83~31.75
[0068] Table 8 below shows aspherical coefficients in the third
embodiment.
TABLE-US-00008 TABLE 8 Lens surface K A B C D S4 1.000000
7.569433E-05 -2.032430E-06 1.835288E-08 -5.102322E-11 S5 -0.148922
2.037117E-05 1.000353E-06 -1.302579E-07 -1.267899E-09 S9
-59045089400675.200000 -3.419725E-06 -3.299992E-07 0.000000E+00
0.000000E+00 S11 -0.171411 -1.634029E-04 1.951675E-06 -1.220379E-08
0.000000E+00 S12 -0.521917 3.014300E-04 -5.728816E-07 1.878143E-08
0.000000E+00 S18 -0.284298 -4.374945E-05 1.126015E-06 0.000000E+00
0.000000E+00
[0069] Table 9 below shows variable distances of the third
embodiment during zooming.
TABLE-US-00009 TABLE 9 Variable Wide-angle Middle Telephoto
distances position position position D1 1.69 6.20 11.44 D2 10.43
3.80 1.05 D3 4.70 5.73 8.07 D4 2.50 4.34 4.71 D5 0.60 0.60 0.60 D6
0.00 0.01 0.03
[0070] FIGS. 6A and 6B illustrate longitudinal spherical
aberration, astigmatic field curves, and distortion of the zoom
lens according to the third embodiment at the wide-angle position
and the telephoto position.
Fourth Embodiment
[0071] FIG. 7 illustrates a zoom lens according to a fourth
embodiment of the invention, and Table 10 shows design data related
to the second embodiment.
TABLE-US-00010 TABLE 10 Lens Radius of Thick- Refractive Abbe
surface curvature ness index (nd) number (vd) S1 32.320 0.90 1.946
17.98 S2 23.017 4.06 1.883 40.81 S3 130.576 D1 S4* 191.465 1.00
1.805 40.90 S5* 7.035 4.43 S6 -27.034 0.55 1.713 53.94 S7 88.521
0.30 S8* 22.066 1.66 2.099 16.80 S9* 82.712 D2 ST infinity 0.60
S11* 7.614 2.28 1.740 48.50 S12* -28.070 0.20 S13 8.773 1.58 1.497
81.61 S14 70.708 0.48 1.847 23.78 S15 5.481 1.29 S16 -12.863 1.37
1.497 81.61 S17 -7.563 D3 S18* 11.157 1.55 1.805 40.90 S19* 20.780
D4 S20 infinity 0.30 1.517 64.17 S21 infinity 0.80 S22 infinity
0.50 1.517 64.17 S23 infinity D5 S24 infinity D6 f;
5.36~12.12~20.38 Fno; 1.87~2.19~2.46 2.omega.;
90.62~41.52~25.22
[0072] Table 11 below shows aspherical coefficients in the fourth
embodiment.
TABLE-US-00011 TABLE 11 Lens surface K A B C D S4 1.000000
1.426570E-04 -2.713131E-06 2.042777E-08 -6.056474E-11 S5 -0.384287
2.285077E-04 3.673567E-06 -6.905222E-08 6.441177E-11 S8 -0.837898
-2.702945E-05 7.213373E-07 -2.039381E-08 0.000000E+00 S9
-316.605354 1.109202E-05 -6.048329E-07 -1.068820E-08 0.000000E+00
S11 -0.202241 -1.913120E-04 2.923898E-06 -6.703731E-08 0.000000E+00
S12 -0.285975 2.736822E-04 7.561435E-07 -4.203271E-08 0.000000E+00
S18 -0.400227 -1.255146E-04 2.120101E-06 -6.323708E-10 0.000000E+00
S19 -0.433684 -1.521260E-04 1.545545E-06 1.759923E-09
0.000000E+00
[0073] Table 12 below shows variable distances of the fourth
embodiment during zooming.
TABLE-US-00012 TABLE 12 Variable Wide-angle Middle Telephoto
distances position position position D1 0.65 10.38 16.78 D2 16.22
5.18 1.30 D3 4.59 5.81 8.36 D4 2.50 4.47 4.64 D5 0.60 0.60 0.60 D6
0.00 0.01 0.02
[0074] FIGS. 8A and 8B illustrate longitudinal spherical
aberration, astigmatic field curves, and distortion of the zoom
lens according to the fourth embodiment at the wide-angle position
and the telephoto position.
[0075] Table 13 below shows that each of the first through fourth
embodiments satisfies the aforementioned Inequalities 1 through
7.
TABLE-US-00013 TABLE 13 First Second Third Fourth embodi- embodi-
embodi- embodi- Inequality ment ment ment ment 1 1.4 .ltoreq. wfno
.ltoreq. 2.5 2.28 1.43 1.90 1.87 2 2 .ltoreq. ft/fw .ltoreq. 5 5.00
3.39 2.70 3.80 3 2.0 .ltoreq. Nd.sub.2 2.003 2.003 2.003 2.099 4 70
.ltoreq. Vd.sub.3 81.60 81.60 70.40 81.60 5 76.degree. .ltoreq.
wfov .ltoreq. 93.degree. 85.79 89.41 79.48 90.62 6 0 < ffno-wfno
.ltoreq. 1.3 0.77 0.57 0.5 0.59 7 1.9 .ltoreq. Nd.sub.1 1.946 1.946
1.946 1.946
[0076] FIG. 9 is a diagram of a photographing apparatus including
the zoom lens 111 according to another embodiment of the invention.
The photographing apparatus includes the zoom lens 111 according to
one of the aforementioned embodiments, and an imaging device 112
receiving light from an image formed by the zoom lens 111. The
photographing apparatus may further include a recording unit 113
recording information about an image of a subject, which is
photoelectrically converted by the imaging device 112, and a
viewfinder 114 for observing the subject. The photographing
apparatus may include a display unit 115 displaying the image of
the subject. Referring to FIG. 9, the viewfinder 114 and the
display unit 115 are separately arranged. However, only the display
unit 115 may be used. The photographing apparatus of FIG. 9 is just
an exemplary embodiment of the invention. Thus, the invention may
be applied to other pieces of various optical equipment other than
a photographing apparatus. Accordingly, optical equipment having a
wide angle of view, high brightness, and high magnification may be
realized.
[0077] While the invention has been particularly shown and
described with reference to exemplary embodiments thereof, it will
be understood by those of ordinary skill in the art that various
changes in form and details may be made therein without departing
from the spirit and scope of the invention as defined by the
following claims.
* * * * *