U.S. patent application number 13/253621 was filed with the patent office on 2012-05-10 for camera system, interchangeable lens and method of manufacturing interchangeable lens.
This patent application is currently assigned to NIKON CORPORATION. Invention is credited to Masanori Hasuda, Hideaki Hoshikawa, Noriyasu Kotani, Toshinori Take.
Application Number | 20120114325 13/253621 |
Document ID | / |
Family ID | 44785549 |
Filed Date | 2012-05-10 |
United States Patent
Application |
20120114325 |
Kind Code |
A1 |
Take; Toshinori ; et
al. |
May 10, 2012 |
CAMERA SYSTEM, INTERCHANGEABLE LENS AND METHOD OF MANUFACTURING
INTERCHANGEABLE LENS
Abstract
A camera system having a predetermined image circle, comprises:
an interchangeable lens having a lens mount portion; and a camera
body having an image sensor that is disposed within that image
circle, and a body mount portion, wherein, when a radius of
circular portion at a maximum internal diameter part of an opening
portion of the lens mount portion is termed rM, a flange back that
is a distance from the lens mount portion to a light reception
surface of an image sensor in a state that the interchangeable lens
and the camera body are mutually engaged is termed da, and the
diameter of the image circle is termed D, the following equations
are satisfied: 14.0 mm.ltoreq.2rM.ltoreq.40.0 mm Conditional
Expression #1 16.0 mm.ltoreq.da.ltoreq.20.0 mm Conditional
Expression #2 14.0 mm.ltoreq.D.ltoreq.20.0 mm Conditional
Expression #3.
Inventors: |
Take; Toshinori;
(Yokohama-shi, JP) ; Hasuda; Masanori;
(Fujisawa-shi, JP) ; Kotani; Noriyasu; (Tokyo,
JP) ; Hoshikawa; Hideaki; (Koshigaya-shi,
JP) |
Assignee: |
NIKON CORPORATION
|
Family ID: |
44785549 |
Appl. No.: |
13/253621 |
Filed: |
October 5, 2011 |
Current U.S.
Class: |
396/529 ;
29/428 |
Current CPC
Class: |
G02B 7/14 20130101; H04N
5/2254 20130101; G02B 27/646 20130101; G03B 17/14 20130101; G02B
13/00 20130101; Y10T 29/49826 20150115 |
Class at
Publication: |
396/529 ;
29/428 |
International
Class: |
G03B 17/00 20060101
G03B017/00; B23P 11/00 20060101 B23P011/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 6, 2010 |
JP |
2010-226549 |
Sep 15, 2011 |
JP |
2011-202391 |
Claims
1. A camera system having a predetermined image circle, comprising:
an interchangeable lens having a lens mount portion for attachment
to a camera body and that is capable of forming an image within
that image circle; and a camera body having an image sensor that is
disposed within that image circle, and a body mount portion for
attaching an interchangeable lens so that it is disposed at a
position separated by a predetermined distance from a light
reception surface of the image sensor, wherein, when a radius of
circular portion at a maximum internal diameter part of an opening
portion of the lens mount portion is termed rM, a flange back that
is a distance from the lens mount portion to the light reception
surface of the image sensor in a state that the interchangeable
lens and the camera body are mutually engaged is termed da, and a
diameter of the image circle is termed D, the following equations
are satisfied: 14.0 mm.ltoreq.2rM.ltoreq.40.0 mm Conditional
Expression #1 16.0 mm.ltoreq.da.ltoreq.20.0 mm Conditional
Expression #2 14.0 mm.ltoreq.D.ltoreq.20.0 mm Conditional
Expression #3.
2. The camera system according to claim 1, wherein, when a distance
upon the optical axis from the lens mount portion to the lens
surface closest to the image is termed L (in case the lens mount
portion is taken as a reference, the direction towards the image
being considered positive and the direction towards the object to
be photographed being considered negative), the following equations
are satisfied: L.ltoreq.11.0 mm Conditional Expression #4.
3. The camera system according to claim 1, wherein, when the
maximum internal diameter part of the opening portion of the lens
mount portion is termed rM, the following equation is satisfied:
18.0 mm.ltoreq.2rM.ltoreq.34.0 mm Conditional Expression #1A.
4. The camera system according to claim 1, wherein, when the
maximum internal diameter part of the opening portion of the lens
mount portion is termed rM, the flange back that is the distance
upon the optical axis from the body mount portion to the light
reception surface of the image sensor in a state that the
interchangeable lens and the camera body are mutually engaged is
termed da, and the aperture ratio of the optical system of the
interchangeable lens is termed F-number, the following equation is
satisfied: 2rM/da.gtoreq.1/F-number Conditional Expression #5.
5. The camera system according to claim 1, wherein, when the
maximum internal diameter part of the opening portion of the lens
mount portion is termed rM, the flange back that is the distance
upon the optical axis from the body mount portion to the light
reception surface of the image sensor in a state that the
interchangeable lens and the camera body are mutually engaged is
termed da, and the aperture ratio of the optical system of the
interchangeable lens is termed F-number, the following equations
are satisfied: 2rM/da.gtoreq.1/F-number Conditional Expression #5
2rM/da.gtoreq.0.7 Conditional Expression #6.
6. The camera system according to claim 1, wherein, when the
maximum internal diameter part of the opening portion of the lens
mount portion is termed rM, the flange back that is the distance
upon the optical axis from the body mount portion to the light
reception surface of the image sensor in a state that the
interchangeable lens and the camera body are mutually engaged is
termed da, and the aperture ratio of the optical system of the
interchangeable lens is termed F-number, the following equations
are satisfied: 2rM/da.gtoreq.1/F-number Conditional Expression #5
2rM/da.gtoreq.0.8 Conditional Expression #6A.
7. The camera system according to claim 1, wherein, when the
maximum internal diameter part of the opening portion of the lens
mount portion is termed rM, the flange back that is the distance
upon the optical axis from the body mount portion to the light
reception surface of the image sensor in a state that the
interchangeable lens and the camera body are mutually engaged is
termed da, and the aperture ratio of the optical of the
interchangeable lens to the camera body is termed F-number, the
following equations are satisfied: 2rM/da.gtoreq.1/F-number
Conditional Expression #5 2rM/da.gtoreq.1.0 Conditional Expression
#6B.
8. An interchangeable lens comprising: a lens mount portion for
attachment to a camera body; and an optical system for focusing an
object image on a light reception plane of an image sensor;
wherein, the interchangeable lens is capable to be attached to the
camera body that has a camera body mount portion and the image
sensor whose whole pixels generate imaging signals can fit inside
of a circle having a diameter in a range from 14.0 mm to 20.0 mm,
and, when a maximum internal diameter part of an opening portion of
the lens mount portion is termed rM and a flange back that is a
distance upon the optical axis from the body mount portion to the
light reception surface of the image sensor in a state that the
interchangeable lens and the camera body are mutually engaged is
termed da, the following equations are satisfied: 14.0
mm.ltoreq.2rM.ltoreq.40.0 mm Conditional Expression #1 16.0
mm.ltoreq.da.ltoreq.20.0 mm Conditional Expression #2.
9. The interchangeable lens according to claim 8, wherein, when a
distance upon the optical axis from the lens mount portion to the
lens surface closest to the image is termed L (in case the lens
mount portion is taken as a reference, the direction towards the
image being considered positive and the direction towards the
object to be photographed being considered negative), the following
equation is satisfied: L.ltoreq.11.0 mm Conditional Expression
#4.
10. The interchangeable lens according to claim 8, wherein, when
the maximum internal diameter part of the opening portion of the
lens mount portion is termed rM, the following equation is
satisfied: 18.0 mm.ltoreq.2rM.ltoreq.34.0 mm Conditional Expression
#1A.
11. The interchangeable lens according to claim 8, wherein, when
the maximum internal diameter part of the opening portion of the
lens mount portion is termed rM, the flange back that is the
distance upon the optical axis from the body mount portion to the
light reception surface of the image sensor in a state that the
interchangeable lens and the camera body are mutually engaged is
termed da, and the aperture ratio of the optical system of the
interchangeable lens is termed F-number, the following equation is
satisfied: 2rM/da.gtoreq.1/F-number Conditional Expression #5.
12. The interchangeable lens according to claim 8, wherein, when
the maximum internal diameter part of the opening portion of the
lens mount portion is termed rM, the flange back that is the
distance upon the optical axis from the body mount portion to the
light reception surface of the image sensor in a state that the
interchangeable lens and the camera body are mutually engaged is
termed da, and the aperture ratio of the optical system of the
interchangeable lens is termed F-number, the following equations
are satisfied: 2rM/da.gtoreq.1/F-number Conditional Expression #5
2rM/da.gtoreq.0.7 Conditional Expression #6.
13. The interchangeable lens according to claim 8, wherein, when
the maximum internal diameter part of the opening portion of the
lens mount portion is termed rM, the flange back that is the
distance upon the optical axis from the body mount portion to the
light reception surface of the image sensor in a state that the
interchangeable lens and the camera body are mutually engaged is
termed da, and the aperture ratio of the optical system of the
interchangeable lens is termed F-number, the following equations
are satisfied: 2rM/da.gtoreq.1/F-number Conditional Expression #5
2rM/da.gtoreq.0.8 Conditional Expression #6A.
14. The interchangeable lens according to claim 8, wherein, when
the maximum internal diameter part of the opening portion of the
lens mount portion is termed rM, the flange back that is the
distance upon the optical axis from the body mount portion to the
light reception surface of the image sensor in a state that the
interchangeable lens and the camera body are mutually engaged is
termed da, and the aperture ratio of the optical of the
interchangeable lens to the camera body is termed F-number, the
following equations are satisfied: 2rM/da.gtoreq.1/F-number
Conditional Expression #5 2rM/da.gtoreq.1.0 Conditional Expression
#6B.
15. An interchangeable lens comprising: a lens mount portion for
attachment to a camera body; and an optical system for focusing an
object image on a light reception plane of an image sensor;
wherein, the interchangeable lens is capable to be attached to the
camera body that has a camera body mount portion and an image
sensor whose whole pixels generate imaging signals can fit inside
of a circle having a diameter in a range from 14.0 mm to 20.0 mm,
and, when a maximum internal diameter part of an opening portion of
the lens mount portion is termed rM and a distance from the lens
mount portion to an image surface of the optical system is termed
dB, the following equations are satisfied: 14.0
mm.ltoreq.2rM.ltoreq.40.0 mm Conditional Expression #1 14.8
mm.ltoreq.dB.ltoreq.18.8 mm Conditional Expression #2-2.
16. The interchangeable lens according to claim 15, wherein, when a
distance upon the optical axis from the lens mount portion to the
lens surface closest to the image is termed L (in case the lens
mount portion is taken as a reference, the direction towards the
image being considered positive and the direction towards the
object to be photographed being considered negative), the following
equation is satisfied: L.ltoreq.11.0 mm Conditional Expression
#4.
17. The interchangeable lens according to claim 15, wherein, when
the maximum internal diameter part of the opening portion of the
lens mount portion is termed rM, the following equation is
satisfied: 18.0 mm.ltoreq.2rM.ltoreq.34.0 mm Conditional Expression
#1A.
18. The interchangeable lens according to claim 15, wherein, when
the maximum internal diameter part of the opening portion of the
lens mount portion is termed rM, the distance from the lens mount
portion to the image surface of the optical system is termed dB,
and the aperture ratio of the optical system of the interchangeable
lens is termed F-number, the following equation is satisfied:
2rM/dB.gtoreq.1/F-number Conditional Expression #5-2.
19. The interchangeable lens according to claim 15, wherein, when
the maximum internal diameter part of the opening portion of the
lens mount portion is termed rM, the distance from the lens mount
portion to the image surface of the optical system is termed dB,
and the aperture ratio of the optical system of the interchangeable
lens is termed F-number, the following equations are satisfied:
2rM/dB.gtoreq.1/F-number Conditional Expression #5-2
2rM/dB.gtoreq.0.7 Conditional Expression #6-2.
20. The interchangeable lens according to claim 15, wherein, when
the maximum internal diameter part of the opening portion of the
lens mount portion is termed rM, the distance from the lens mount
portion to the image surface of the optical system is termed dB,
and the aperture ratio of the optical system of the interchangeable
lens is termed F-number, the following equations are satisfied:
2rM/dB.gtoreq.1/F-number Conditional Expression #5-2
2rM/dB.gtoreq.0.8 Conditional Expression #6-2A.
21. The interchangeable lens according to claim 15, wherein, when
the maximum internal diameter part of the opening portion of the
lens mount portion is termed rM, the distance from the lens mount
portion to the image surface of the optical system is termed dB,
and the aperture ratio of the optical of the interchangeable lens
to the camera body is termed F-number, the following equations are
satisfied: 2rM/dB.gtoreq.1/F-number Conditional Expression #5-2
2rM/dB.gtoreq.1.0 Conditional Expression #6-2B.
22. A method of manufacturing an interchangeable lens that is
capable to be attached to the camera body that has a camera body
mount portion and the image sensor whose whole pixels generate
imaging signals can fit inside of a circle having a diameter in a
range from 14.0 mm to 20.0 mm, comprising: when a maximum internal
diameter part of an opening portion of the lens mount portion is
termed rM and a flange back that is a distance upon the optical
axis from the body mount portion to the light reception surface of
the image sensor in a state that the interchangeable lens and the
camera body are mutually engaged is termed da, forming a lens mount
so as to be satisfied the following equations: 14.0
mm.ltoreq.2rM.ltoreq.40.0 mm Conditional Expression #1 16.0
mm.ltoreq.da.ltoreq.20.0 mm Conditional Expression #2, and
assembling the interchangeable lens by combining the lens mount
with an optical system.
23. A method of manufacturing an interchangeable lens according to
claim 22, further comprising, when a distance upon the optical axis
from the lens mount portion to the lens surface closest to the
image is termed L (in case the lens mount portion is taken as a
reference, the direction towards the image being considered
positive and the direction towards the object to be photographed
being considered negative), forming a lens mount so as to be
satisfied the following equation: L.ltoreq.11.0 mm Conditional
Expression #4.
24. A method of manufacturing an interchangeable lens according to
claim 22, further comprising, when the maximum internal diameter
part of the opening portion of the lens mount portion is termed rM,
forming a lens mount so as to be satisfied the following equation:
18.0 mm.ltoreq.2rM.ltoreq.34.0 mm Conditional Expression #1A.
25. A method of manufacturing an interchangeable lens according to
claim 22, further comprising, when the maximum internal diameter
part of the opening portion of the lens mount portion is termed rM,
the flange back that is the distance upon the optical axis from the
body mount portion to the light reception surface of the image
sensor in a state that the interchangeable lens and the camera body
are mutually engaged is termed da, and the aperture ratio of the
optical system of the interchangeable lens is termed F-number,
forming a lens mount so as to be satisfied the following equation:
2rM/da.gtoreq.1/F-number Conditional Expression #5.
26. A method of manufacturing an interchangeable lens according to
claim 22, further comprising, when the maximum internal diameter
part of the opening portion of the lens mount portion is termed rM,
the flange back that is the distance upon the optical axis from the
body mount portion to the light reception surface of the image
sensor in a state that the interchangeable lens and the camera body
are mutually engaged is termed da, and the aperture ratio of the
optical system of the interchangeable lens is termed F-number,
forming a lens mount so as to be satisfied the following equations:
2rM/da.gtoreq.1/F-number Conditional Expression #5
2rM/da.gtoreq.0.7 Conditional Expression #6.
27. A method of manufacturing an interchangeable lens according to
claim 22, further comprising, when the maximum internal diameter
part of the opening portion of the lens mount portion is termed rM,
the flange back that is the distance upon the optical axis from the
body mount portion to the light reception surface of the image
sensor in a state that the interchangeable lens and the camera body
are mutually engaged is termed da, and the aperture ratio of the
optical system of the interchangeable lens is termed F-number,
forming a lens mount so as to be satisfied the following equations:
2rM/da.gtoreq.1/F-number Conditional Expression #5
2rM/da.gtoreq.0.8 Conditional Expression #6A.
28. A method of manufacturing an interchangeable lens according to
claim 22, further comprising, when the maximum internal diameter
part of the opening portion of the lens mount portion is termed rM,
the flange back that is the distance upon the optical axis from the
body mount portion to the light reception surface of the image
sensor in a state that the interchangeable lens and the camera body
are mutually engaged is termed da, and the aperture ratio of the
optical of the interchangeable lens to the camera body is termed
F-number, forming a lens mount so as to be satisfied the following
equations: 2rM/da.gtoreq.1/F-number Conditional Expression #5
2rM/da.gtoreq.1.0 Conditional Expression #6B.
29. A method of manufacturing an interchangeable lens that is
capable to be attached to the camera body that has a camera body
mount portion and the image sensor whose whole pixels generate
imaging signals can fit inside of a circle having a diameter in a
range from 14.0 mm to 20.0 mm, comprising: when a maximum internal
diameter part of an opening portion of the lens mount portion is
termed rM and a distance from the lens mount portion to an image
surface of the optical system is termed dB, forming a lens mount so
as to be satisfied the following equations: 14.0
mm.ltoreq.2rM.ltoreq.40.0 mm Conditional Expression #1 14.8
mm.ltoreq.dB.ltoreq.18.8 mm Conditional Expression #2-2, and
assembling the interchangeable lens by combining the lens mount
with an optical system.
30. A method of manufacturing an interchangeable lens according to
claim 29, further comprising, when a distance upon the optical axis
from the lens mount portion to the lens surface closest to the
image is termed L (in case the lens mount portion is taken as a
reference, the direction towards the image being considered
positive and the direction towards the object to be photographed
being considered negative), forming a lens mount so as to be
satisfied the following equation: L.ltoreq.11.0 mm Conditional
Expression #4.
31. A method of manufacturing an interchangeable lens according to
claim 29, further comprising, when the maximum internal diameter
part of the opening portion of the lens mount portion is termed rM,
forming a lens mount so as to be satisfied the following equation:
18.0 mm.ltoreq.2rM.ltoreq.34.0 mm Conditional Expression #1A.
32. A method of manufacturing an interchangeable lens according to
claim 29, further comprising, when the maximum internal diameter
part of the opening portion of the lens mount portion is termed rM,
the distance from the lens mount portion to the image surface of
the optical system is termed dB, and the aperture ratio of the
optical system of the interchangeable lens is termed F-number,
forming a lens mount so as to be satisfied the following equation:
2rM/dB.gtoreq.1/F-number Conditional Expression #5-2.
33. A method of manufacturing an interchangeable lens according to
claim 29, further comprising, when the maximum internal diameter
part of the opening portion of the lens mount portion is termed rM,
the distance from the lens mount portion to the image surface of
the optical system is termed dB, and the aperture ratio of the
optical system of the interchangeable lens is termed F-number,
forming a lens mount so as to be satisfied the following equations:
2rM/dB.gtoreq.1/F-number Conditional Expression #5-2
2rM/dB.gtoreq.0.7 Conditional Expression #6-2.
34. A method of manufacturing an interchangeable lens according to
claim 29, further comprising, when the maximum internal diameter
part of the opening portion of the lens mount portion is termed rM,
the distance from the lens mount portion to the image surface of
the optical system is termed dB, and the aperture ratio of the
optical system of the interchangeable lens is termed F-number,
forming a lens mount so as to be satisfied the following equations:
2rM/dB.gtoreq.1/F-number Conditional Expression #5-2
2rM/dB.gtoreq.0.8 Conditional Expression #6-2A.
35. A method of manufacturing an interchangeable lens according to
claim 29, further comprising, when the maximum internal diameter
part of the opening portion of the lens mount portion is termed rM,
the distance from the lens mount portion to the image surface of
the optical system is termed dB, and the aperture ratio of the
optical of the interchangeable lens to the camera body is termed
F-number, forming a lens mount so as to be satisfied the following
equations: 2rM/dB.gtoreq.1/F-number Conditional Expression #5-2
2rM/dB.gtoreq.1.0 Conditional Expression #6-2B.
Description
INCORPORATION BY REFERENCE
[0001] The disclosure of the following priority application is
herein incorporated by reference: Japanese Patent Application No.
2010-226549 and Japanese Patent Application No. 2011-202391 filed
Sep. 15, 2011.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a camera system that
includes a camera body and an interchangeable lens, interchangeable
lens and a method of manufacturing an interchangeable lens.
[0004] 2. Description of Related Art
[0005] From the past, with digital cameras and video cameras and so
on, camera systems and interchangeable lenses have been per se
known that include mounts on the lens side and on the camera body
side, and with which the lenses can be interchanged (for example,
refer to Japanese Laid-Open Patent Publication 2005-6122).
SUMMARY OF THE INVENTION
[0006] However, with prior art camera systems and interchangeable
lens, the image circle is large, and there has been the problem
that the entire camera system cannot be made sufficiently
compact.
[0007] The present invention has been conceived in consideration of
the problem described above, and its object is to provide a camera
system and an interchangeable lens with which it is possible to
obtain the desired optical performance in a compact and thin
form.
[0008] According to the first aspect of the present invention, a
camera system having a predetermined image circle, comprises: an
interchangeable lens having a lens mount portion for attachment to
a camera body and that is capable of forming an image within that
image circle; and a camera body having an imaging element (image
sensor) that is disposed within that image circle, and a body mount
portion for attaching an interchangeable lens so that it is
disposed at a position separated by a predetermined distance from a
light reception surface of the imaging element (image sensor),
wherein, when a radius of circular portion at a maximum internal
diameter part of the opening portion of the lens mount portion is
termed rM, a flange back that is a distance from the lens mount
portion to a light reception surface of an imaging element (image
sensor) in a state that an interchangeable lens and a camera body
are mutually engaged is termed da, and the diameter of the image
circle is termed D, the following equations are satisfied:
14.0 mm.ltoreq.2rM.ltoreq.40.0 mm Conditional Expression #1
16.0 mm.ltoreq.da.ltoreq.20.0 mm Conditional Expression #2
14.0 mm.ltoreq.D.ltoreq.20.0 mm Conditional Expression #3.
[0009] According to the second aspect of the present invention, in
the camera system of the first aspect, it is preferred that, when a
distance upon the optical axis from the lens mount portion to the
lens surface closest to the image is termed L (in case the lens
mount portion is taken as a reference, the direction towards the
image being considered positive and the direction towards the
object to be photographed being considered negative), the following
equations are satisfied:
L.ltoreq.11.0 mm Conditional Expression #4.
[0010] According to the third aspect of the present invention, in
the camera system of the first or the second aspect, it is
preferred that, when the maximum internal diameter part of the
opening portion of the lens mount portion is termed rM, the
following equation is satisfied:
18.0 mm.ltoreq.2rM.ltoreq.34.0 mm Conditional Expression #1A.
[0011] According to the fourth aspect of the present invention, in
the camera system of any one of the first through the third aspect,
it is preferred that, when the maximum internal diameter part of
the opening portion of the lens mount portion is termed rM, the
flange back that is the distance upon the optical axis from the
body mount portion to the light reception surface of the imaging
element (image sensor) in a state that the interchangeable lens and
the camera body are mutually engaged is termed da, and the aperture
ratio of the optical system of the interchangeable lens is termed
F-number, the following equation is satisfied:
2rM/da.gtoreq.1/F-number Conditional Expression #5.
[0012] According to the fifth aspect of the present invention, in
the camera system of any one of the first through the third aspect,
it is preferred that, when the maximum internal diameter part of
the opening portion of the lens mount portion is termed rM, the
flange back that is the distance upon the optical axis from the
body mount portion to the light reception surface of the imaging
element (image sensor) in a state that the interchangeable lens and
the camera body are mutually engaged is termed da, and the aperture
ratio of the optical system of the interchangeable lens is termed
F-number, the following equations are satisfied:
2rM/da.gtoreq.1/F-number Conditional Expression #5
2rM/da.gtoreq.0.7 Conditional Expression #6.
[0013] According to the sixth aspect of the present invention, in
the camera system of any one of the first through the third aspect,
it is preferred that, when the maximum internal diameter part of
the opening portion of the lens mount portion is termed rM, the
flange back that is the distance upon the optical axis from the
body mount portion to the light reception surface of the imaging
element (image sensor) in a state that the interchangeable lens and
the camera body are mutually engaged is termed da, and the aperture
ratio of the optical system of the interchangeable lens is termed
F-number, the following equations are satisfied:
2rM/da.gtoreq.1/F-number Conditional Expression #5
2rM/da.gtoreq.0.8 Conditional Expression #6A.
[0014] According to the seventh aspect of the present invention, in
the camera system of any one of the first through the third aspect,
it is preferred that, when the maximum internal diameter part of
the opening portion of the lens mount portion is termed rM, the
flange back that is the distance upon the optical axis from the
body mount portion to the light reception surface of the imaging
element (image sensor) in a state that the interchangeable lens and
the camera body are mutually engaged is termed da, and the aperture
ratio of the optical of the interchangeable lens to the camera body
is termed F-number, the following equations are satisfied:
2rM/da.gtoreq.1/F-number Conditional Expression #5
2rM/da.gtoreq.1.0 Conditional Expression #6B.
[0015] According to the eighth aspect of the present invention, an
interchangeable lens comprises a lens mount portion for attachment
to a camera body; and an optical system for focusing an object
image on a light reception plane of the imaging element (image
sensor); wherein, the interchangeable lens is capable to be
attached to the camera body that has a camera body mount portion
and an imaging element (image sensor) whose whole pixels generate
imaging signals can fit inside of a circle having a diameter in a
range from 14.0 mm to 20.0 mm, and, when a maximum internal
diameter part of an opening portion of the lens mount portion is
termed rM and a flange back that is a distance upon the optical
axis from the body mount portion to the light reception surface of
the imaging element (image sensor) in a state that the
interchangeable lens and the camera body are mutually engaged is
termed da, the following equation is satisfied:
14.0 mm.ltoreq.2rM.ltoreq.40.0 mm Conditional Expression #1
16.0 mm.ltoreq.da.ltoreq.20.0 mm Conditional Expression #2.
[0016] According to the ninth aspect of the present invention, in
the interchangeable lens of the eighth aspect, it is preferred
that, when a distance upon the optical axis from the lens mount
portion to the lens surface closest to the image is termed L (in
case the lens mount portion is taken as a reference, the direction
towards the image being considered positive and the direction
towards the object to be photographed being considered negative),
the following equations are satisfied:
L.ltoreq.11.0 mm Conditional Expression #4.
[0017] According to the tenth aspect of the present invention, in
the interchangeable lens of the eighth or the ninth aspect, it is
preferred that, when the maximum internal diameter part of the
opening portion of the lens mount portion is termed rM, the
following equation is satisfied:
18.0 mm.ltoreq.2rM.ltoreq.34.0 mm Conditional Expression #1A.
[0018] According to the eleventh aspect of the present invention,
in the interchangeable lens of any one of the eighth through the
tenth aspect, it is preferred that, when the maximum internal
diameter part of the opening portion of the lens mount portion is
termed rM, the flange back that is the distance upon the optical
axis from the body mount portion to the light reception surface of
the imaging element (image sensor) in a state that the
interchangeable lens and the camera body are mutually engaged is
termed da, and the aperture ratio of the optical system of the
interchangeable lens is termed F-number, the following equation is
satisfied:
2rM/da.gtoreq.1/F-number Conditional Expression #5.
[0019] According to the twelfth aspect of the present invention, in
the interchangeable lens of any one of the eighth through the tenth
aspect, it is preferred that, when the maximum internal diameter
part of the opening portion of the lens mount portion is termed rM,
the flange back that is the distance upon the optical axis from the
body mount portion to the light reception surface of the imaging
element (image sensor) in a state that the interchangeable lens and
the camera body are mutually engaged is termed da, and the aperture
ratio of the optical system of the interchangeable lens is termed
F-number, the following equations are satisfied:
2rM/da.gtoreq.1/F-number Conditional Expression #5
2rM/da.gtoreq.0.7 Conditional Expression #6.
[0020] According to the thirteenth aspect of the present invention,
in the interchangeable lens of any one of the eighth through the
tenth aspect, it is preferred that, when the maximum internal
diameter part of the opening portion of the lens mount portion is
termed rM, the flange back that is the distance upon the optical
axis from the body mount portion to the light reception surface of
the imaging element (image sensor) in a state that the
interchangeable lens and the camera body are mutually engaged is
termed da, and the aperture ratio of the optical system of the
interchangeable lens is termed F-number, the following equations
are satisfied:
2rM/da.gtoreq.1/F-number Conditional Expression #5
2rM/da.gtoreq.0.8 Conditional Expression #6A.
[0021] According to the fourteenth aspect of the present invention,
in the interchangeable lens of any one of the eighth through the
tenth aspect, it is preferred that, when the maximum internal
diameter part of the opening portion of the lens mount portion is
termed rM, the flange back that is the distance upon the optical
axis from the body mount portion to the light reception surface of
the imaging element (image sensor) in a state that the
interchangeable lens and the camera body are mutually engaged is
termed da, and the aperture ratio of the optical of the
interchangeable lens to the camera body is termed F-number, the
following equations are satisfied:
2rM/da.gtoreq.1/F-number Conditional Expression #5
2rM/da.gtoreq.1.0 Conditional Expression #6B.
[0022] According to the fifteenth aspect of the present invention,
an interchangeable lens comprises a lens mount portion for
attachment to the camera body; and an optical system for focusing
an object image on a light reception plane of the imaging element
(image sensor); wherein, the interchangeable lens is capable to be
attached to a camera body that has a camera body mount portion and
an imaging element (image sensor) whose whole pixels generate
imaging signals can fit inside of a circle having a diameter in a
range from 14.0 mm to 20.0 mm, and, when a maximum internal
diameter part of an opening portion of the lens mount portion is
termed rM and a distance from the lens mount portion to an image
surface of the optical system is termed dB, the following equation
is satisfied:
14.0 mm.ltoreq.2rM.ltoreq.40.0 mm Conditional Expression #1
14.8 mm.ltoreq.dB.ltoreq.18.8 mm Conditional Expression #2-2.
[0023] According to the sixteenth aspect of the present invention,
in the interchangeable lens of the fifteenth aspect, it is
preferred that, when a distance upon the optical axis from the lens
mount portion to the lens surface closest to the image is termed L
(in case the lens mount portion is taken as a reference, the
direction towards the image being considered positive and the
direction towards the object to be photographed being considered
negative), the following equations are satisfied:
L.ltoreq.11.0 mm Conditional Expression #4.
[0024] According to the seventeenth aspect of the present
invention, in the interchangeable lens of the fifteenth or the
sixteenth aspect, it is preferred that, when the maximum internal
diameter part of the opening portion of the lens mount portion is
termed rM, the following equation is satisfied:
18.0 mm.ltoreq.2rM.ltoreq.34.0 mm Conditional Expression #1A.
[0025] According to the eighteenth aspect of the present invention,
in the interchangeable lens of any one of the fifteenth through the
seventeenth aspect, it is preferred that, when the maximum internal
diameter part of the opening portion of the lens mount portion is
termed rM, the distance from the lens mount portion to the image
surface of the optical system is termed dB, and the aperture ratio
of the optical system of the interchangeable lens is termed
F-number, the following equation is satisfied:
2rM/dB.gtoreq.1/F-number Conditional Expression #5-2.
[0026] According to the nineteenth aspect of the present invention,
in the interchangeable lens of any one of the fifteenth through the
seventeenth aspect, it is preferred that, when the maximum internal
diameter part of the opening portion of the lens mount portion is
termed rM, the distance from the lens mount portion to the image
surface of the optical system is termed dB, and the aperture ratio
of the optical system of the interchangeable lens is termed
F-number, the following equations are satisfied:
2rM/dB.gtoreq.1/F-number Conditional Expression #5-2
2rM/dB.gtoreq.0.7 Conditional Expression #6-2.
[0027] According to the twentieth aspect of the present invention,
in the interchangeable lens of any one of the fifteenth through the
seventeenth aspect, it is preferred that, when the maximum internal
diameter part of the opening portion of the lens mount portion is
termed rM, the distance from the lens mount portion to the image
surface of the optical system is termed dB, and the aperture ratio
of the optical system of the interchangeable lens is termed
F-number, the following equations are satisfied:
2rM/dB.gtoreq.1/F-number Conditional Expression #5-2
2rM/dB.gtoreq.0.8 Conditional Expression #6-2A.
[0028] According to the twenty-first aspect of the present
invention, in the interchangeable lens of any one of the fifteenth
through the seventeenth aspect, it is preferred that, when the
maximum internal diameter part of the opening portion of the lens
mount portion is termed rM, the distance from the lens mount
portion to the image surface of the optical system is termed dB,
and the aperture ratio of the optical of the interchangeable lens
to the camera body is termed F-number, the following equations are
satisfied:
2rM/dB.gtoreq.1/F-number Conditional Expression #5-2
2rM/dB.gtoreq.1.0 Conditional Expression #6-2B.
[0029] According to the twenty-second aspect of the present
invention, a method of manufacturing an interchangeable lens that
is capable to be attached to the camera body that has a camera body
mount portion and the image sensor whose whole pixels generate
imaging signals can fit inside of a circle having a diameter in a
range from 14.0 mm to 20.0 mm, comprises, when a maximum internal
diameter part of an opening portion of the lens mount portion is
termed rM and a flange back that is a distance upon the optical
axis from the body mount portion to the light reception surface of
the image sensor in a state that the interchangeable lens and the
camera body are mutually engaged is termed da, forming a lens mount
so as to be satisfied the following equations:
14.0 mm.ltoreq.2rM.ltoreq.40.0 mm Conditional Expression #1
16.0 mm.ltoreq.da.ltoreq.20.0 mm Conditional Expression #2, and
assembling the interchangeable lens by combining the lens mount
with an optical system.
[0030] According to the twenty-third aspect of the present
invention, in the method of manufacturing an interchangeable lens
of the twenty-second aspect, it is preferred that, when the maximum
internal diameter part of the opening portion of the lens mount
portion is termed rM, forming a lens mount so as to be satisfied
the following equation:
18.0 mm.ltoreq.2rM.ltoreq.34.0 mm Conditional Expression #1A.
[0031] According to the twenty-fourth aspect of the present
invention, in the method of manufacturing an interchangeable lens
of the twenty-second aspect, it is preferred that, when the maximum
internal diameter part of the opening portion of the lens mount
portion is termed rM, forming a lens mount so as to be satisfied
the following equation:
18.0 mm.ltoreq.2rM.ltoreq.34.0 mm Conditional Expression #1A.
[0032] According to the twenty-fifth aspect of the present
invention, in the method of manufacturing an interchangeable lens
of the twenty-second aspect, it is preferred that, when the maximum
internal diameter part of the opening portion of the lens mount
portion is termed rM, the flange back that is the distance upon the
optical axis from the body mount portion to the light reception
surface of the image sensor in a state that the interchangeable
lens and the camera body are mutually engaged is termed da, and the
aperture ratio of the optical system of the interchangeable lens is
termed F-number, forming a lens mount so as to be satisfied the
following equation:
2rM/da.gtoreq.1/F-number Conditional Expression #5.
[0033] According to the twenty-sixth aspect of the present
invention, in the method of manufacturing an interchangeable lens
of the twenty-second aspect, it is preferred that, when the maximum
internal diameter part of the opening portion of the lens mount
portion is termed rM, the flange back that is the distance upon the
optical axis from the body mount portion to the light reception
surface of the image sensor in a state that the interchangeable
lens and the camera body are mutually engaged is termed da, and the
aperture ratio of the optical system of the interchangeable lens is
termed F-number, forming a lens mount so as to be satisfied the
following equations:
2rM/da.gtoreq.1/F-number Conditional Expression #5
2rM/da.gtoreq.0.7 Conditional Expression #6.
[0034] According to the twenty-seventh aspect of the present
invention, in the method of manufacturing an interchangeable lens
of the twenty-second aspect, it is preferred that, when the maximum
internal diameter part of the opening portion of the lens mount
portion is termed rM, the flange back that is the distance upon the
optical axis from the body mount portion to the light reception
surface of the image sensor in a state that the interchangeable
lens and the camera body are mutually engaged is termed da, and the
aperture ratio of the optical system of the interchangeable lens is
termed F-number, forming a lens mount so as to be satisfied the
following equations:
2rM/da.gtoreq.1/F-number Conditional Expression #5
2rM/da.gtoreq.0.8 Conditional Expression #6A.
[0035] According to the twenty-eighth aspect of the present
invention, in the method of manufacturing an interchangeable lens
of the twenty-second aspect, it is preferred that, when the maximum
internal diameter part of the opening portion of the lens mount
portion is termed rM, the flange back that is the distance upon the
optical axis from the body mount portion to the light reception
surface of the image sensor in a state that the interchangeable
lens and the camera body are mutually engaged is termed da, and the
aperture ratio of the optical of the interchangeable lens to the
camera body is termed F-number, forming a lens mount so as to be
satisfied the following equations:
2rM/da.gtoreq.1/F-number Conditional Expression #5
2rM/da.gtoreq.1.0 Conditional Expression #6B.
[0036] According to the twenty-ninth aspect of the present
invention, a method of manufacturing an interchangeable lens that
is capable to be attached to the camera body that has a camera body
mount portion and the image sensor whose whole pixels generate
imaging signals can fit inside of a circle having a diameter in a
range from 14.0 mm to 20.0 mm, comprises, when a maximum internal
diameter part of an opening portion of the lens mount portion is
termed rM and a distance from the lens mount portion to an image
surface of the optical system is termed dB, forming a lens mount so
as to be satisfied the following equations:
14.0 mm.ltoreq.2rM.ltoreq.40.0 mm Conditional Expression #1
14.8 mm.ltoreq.dB.ltoreq.18.8 mm Conditional Expression #2-2,
and
assembling the interchangeable lens by combining the lens mount
with an optical system.
[0037] According to the thirtieth aspect of the present invention,
in the method of manufacturing an interchangeable lens of the
twenty-ninth aspect, it is preferred that, when a distance upon the
optical axis from the lens mount portion to the lens surface
closest to the image is termed L (in case the lens mount portion is
taken as a reference, the direction towards the image being
considered positive and the direction towards the object to be
photographed being considered negative), forming a lens mount so as
to be satisfied the following equation:
L.ltoreq.11.0 mm Conditional Expression #4.
[0038] According to the thirty-first aspect of the present
invention, in the method of manufacturing an interchangeable lens
of the twenty-ninth aspect, it is preferred that, when the maximum
internal diameter part of the opening portion of the lens mount
portion is termed rM, forming a lens mount so as to be satisfied
the following equation:
18.0 mm.ltoreq.2rM.ltoreq.34.0 mm Conditional Expression #1A.
[0039] According to the thirty-second aspect of the present
invention, in the method of manufacturing an interchangeable lens
of the twenty-ninth aspect, it is preferred that, when the maximum
internal diameter part of the opening portion of the lens mount
portion is termed rM, the distance from the lens mount portion to
the image surface of the optical system is termed dB, and the
aperture ratio of the optical system of the interchangeable lens is
termed F-number, forming a lens mount so as to be satisfied the
following equation:
2rM/dB.gtoreq.1/F-number Conditional Expression #5-2.
[0040] According to the thirty-third aspect of the present
invention, in the method of manufacturing an interchangeable lens
of the twenty-ninth aspect, it is preferred that, when the maximum
internal diameter part of the opening portion of the lens mount
portion is termed rM, the distance from the lens mount portion to
the image surface of the optical system is termed dB, and the
aperture ratio of the optical system of the interchangeable lens is
termed F-number, forming a lens mount so as to be satisfied the
following equations:
2rM/dB.gtoreq.1/F-number Conditional Expression #5-2
2rM/dB.gtoreq.0.7 Conditional Expression #6-2.
[0041] According to the thirty-fourth aspect of the present
invention, in the method of manufacturing an interchangeable lens
of the twenty-ninth aspect, it is preferred that, when the maximum
internal diameter part of the opening portion of the lens mount
portion is termed rM, the distance from the lens mount portion to
the image surface of the optical system is termed dB, and the
aperture ratio of the optical system of the interchangeable lens is
termed F-number, forming a lens mount so as to be satisfied the
following equations:
2rM/dB.gtoreq.1/F-number Conditional Expression #5-2
2rM/dB.gtoreq.0.8 Conditional Expression #6-2A.
[0042] According to the thirty-fifth aspect of the present
invention, in the method of manufacturing an interchangeable lens
of the twenty-ninth aspect, it is preferred that, when the maximum
internal diameter part of the opening portion of the lens mount
portion is termed rM, the distance from the lens mount portion to
the image surface of the optical system is termed dB, and the
aperture ratio of the optical of the interchangeable lens to the
camera body is termed F-number, forming a lens mount so as to be
satisfied the following equations:
2rM/dB.gtoreq.1/F-number Conditional Expression #5-2
2rM/dB.gtoreq.1.0 Conditional Expression #6-2B.
BRIEF DESCRIPTION OF THE DRAWINGS
[0043] FIG. 1 shows a schematic constructional figure showing an
interchangeable lens and a camera body incorporating the present
invention in the mutually disengaged state;
[0044] FIG. 2 shows a schematic constructional figure showing this
interchangeable lens and camera body incorporating the present
invention in the mutually engaged state;
[0045] FIG. 3 shows a sectional view showing the structure of an
interchangeable lens that incorporates a lens mount portion
according to a first embodiment;
[0046] FIG. 4 shows a sectional view showing the structure of an
interchangeable lens that incorporates a lens mount portion
according to a second embodiment;
[0047] FIG. 5 shows a sectional view showing the structure of an
interchangeable lens that incorporates a lens mount portion
according to a third embodiment;
[0048] FIG. 6 shows a sectional view showing the structure of an
interchangeable lens that incorporates a lens mount portion
according to a fourth embodiment; and
[0049] FIG. 7 shows a sectional view showing the structure of an
interchangeable lens that incorporates a lens mount portion
according to a fifth embodiment.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0050] FIG. 1 is a schematic constructional figure showing an
interchangeable lens 1 and a camera body 2 incorporating a camera
system according to the present invention in the mutually
disengaged state, and FIG. 2 shows this interchangeable lens 1 and
camera body 2 in the mutually engaged state. Referring to these
figures, the camera system according to the present invention has a
predetermined image circle, and includes the interchangeable lens 1
that has a lens mount portion for attachment to the camera body 2
and that is capable of forming an image within that image circle,
and the camera body 2 that has an imaging element (image sensor)
disposed within that image circle and a camera body mount portion
2a for attaching the interchangeable lens 1 so that it is disposed
at a position separated by a predetermined distance from the light
reception surface I of the imaging element (image sensor), wherein,
when a radius of circular portion at a maximum internal diameter
part of the opening portion of the lens mount portion is termed rM,
the "flange back" (i.e. the distance upon the optical axis from the
camera body mount portion to the light reception surface of the
imaging element (image sensor) in a state that the interchangeable
lens 1 and the camera body 2 are mutually engaged) is termed da,
and the diameter of the image circle is termed D, then, by
satisfying the following conditional expressions, it is possible to
obtain a camera system with which it is possible to obtain an
excellent imaging performance with a compact and thin
structure:
14.0 mm.ltoreq.2rM.ltoreq.40.0 mm Conditional Expression #1
16.0 mm.ltoreq.da.ltoreq.20.0 mm Conditional Expression #2
14.0 mm.ltoreq.D.ltoreq.20.0 mm Conditional Expression #3.
[0051] Furthermore, when the distance upon the optical axis from
the lens mount portion to the lens surface closest to the image is
termed L (in case the lens mount portion being taken as a
reference, the direction towards the image is considered positive
and the direction towards the object that is to be photographed is
considered negative), it is possible to obtain a camera with a
suitable size:
L.ltoreq.11.0 mm Conditional Expression #4.
[0052] Furthermore, by the camera system according to the present
invention satisfying the following conditional expressions, it is
possible to obtain a camera system with which it is possible to
implement a lens having a high aperture ratio with a sufficient
amount of peripheral light.
2rM/da.gtoreq.1/F-number Conditional Expression #5
2rM/da.gtoreq.0.7 Conditional Expression #6.
[0053] Furthermore, the interchangeable lens according to the
present invention has a lens mount portion for attachment to the
camera body, and optical system that is capable of forming an image
on a light reception surface of the imaging element (image sensor),
and is capable to be attached to the camera body that has a camera
body mount portion and an imaging element (image sensor) whose
whole pixels generating imaging signals can fit inside of a circle
whose diameter is in a range from 14.0 mm to 20.0 mm, and when a
radius of circular portion at a maximum internal diameter part of
the opening portion of the lens mount portion is termed rM, the
flange back that is the distance upon the optical axis from the
camera body mount portion to the light reception surface of the
imaging element (image sensor) in a state that the interchangeable
lens and the camera body are mutually engaged is termed da, it is
possible to obtain a camera system with which it is possible to
obtain an excellent imaging performance with a compact and thin
structure:
14.0 mm.ltoreq.2rM.ltoreq.40.0 mm Conditional Expression #1
16.0 mm.ltoreq.da.ltoreq.20.0 mm Conditional Expression #2.
[0054] Furthermore, the interchangeable lens according to the
present invention has a lens mount portion for attachment to the
camera body and optical system that is capable of forming an image
on a light reception surface of the imaging element (image sensor),
and is capable to be attached to the camera body that has a camera
body mount portion and an imaging element (image sensor) whose
whole pixels generating imaging signals can fit inside of a circle
whose diameter is in a range from 14.0 mm to 20.0 mm, and when a
radius of circular portion at a maximum internal diameter part of
the opening portion of the lens mount portion is termed rM, a
distance from the lens mount portion to an image surface of the
optical system is termed dB, it is possible to obtain a camera
system with which it is possible to obtain an excellent imaging
performance with a compact and thin structure:
14.0 mm.ltoreq.2rM.ltoreq.40.0 mm Conditional Expression #1
14.8 mm.ltoreq.dB.ltoreq.18.8 mm Conditional Expression #2-2.
[0055] Furthermore, by the interchangeable lens according to the
present invention satisfying the following conditional expressions,
it is possible to obtain a interchangeable lens having a high
aperture ratio with a sufficient amount of peripheral light.
2rM/dB.gtoreq.1/F-number Conditional Expression #5-2
2rM/dB.gtoreq.0.7 Conditional Expression #6-2.
[0056] Conditional Expression #1 is a conditional expression for
prescribing an optimum range for a radius of circular portion at a
maximum internal diameter part of the opening portion of the lens
mount portion rM of this camera system.
[0057] If the upper limit value in Conditional Expression #1 is
exceeded, then the internal diameter of the lens mount portion is
undesirably increased in size, and as a result this leads to
undesirable increase in size of the camera body.
[0058] If the lower limit value in Conditional Expression #1 is not
attained, then the lens mount portion internal diameter becomes
small with respect to the image circle, and this is undesirable,
and it becomes difficult to fit a lens that has a high aperture
ratio. Moreover, this is not desirable because it becomes
impossible to obtain a sufficient amount of peripheral light.
[0059] Furthermore, it is desirable for the radius of circular
portion at a maximum internal diameter part of the opening portion
of the lens mount portion rM to satisfy the condition 18.0
mm.ltoreq.2rM.ltoreq.34.0 mm.
[0060] Conditional Expression #2 is a conditional expression for
prescribing an optimum range for the flange back da, in order to
attain an overall balance between compactness and performance of
this camera system.
[0061] If the upper limit value in Conditional Expression #2 is
exceeded, then it is necessary to design a lens having a long back
focus, and as a result the total length of the lens is increased,
that is undesirable. Moreover, the body becomes thicker, and this
is also undesirable.
[0062] If the lower limit value in Conditional Expression #2 is not
attained, then it is necessary to shorten the back focus, and as a
result the exit pupil becomes short, and this is not desirable.
Moreover, undesirable constraints arise with regard to ensuring the
strength of the mounting members and arranging the members and so
on.
[0063] It should be understood that, in order to ensure the
benefits of the present invention, it is desirable to make the
upper limit value in Conditional Expression #2 be 19.5. Moreover,
in order further to ensure the benefits of the present invention,
it is desirable to make the upper limit value in Conditional
Expression #2 be 19.0. Yet further, in order even further to ensure
the benefits of the present invention, it is desirable to make the
upper limit value in Conditional Expression #2 be 18.5.
Furthermore, in order to ensure the benefits of the present
invention, it is desirable to make the lower limit value in
Conditional Expression #2 be 16.5. Moreover, in order further to
ensure the benefits of the present invention, it is desirable to
make the lower limit value in Conditional Expression #2 be 17.0.
Yet further, in order even further to ensure the benefits of the
present invention, it is desirable to make the lower limit value in
Conditional Expression #2 be 17.5.
[0064] Conditional Expression #2-2 is a conditional expression for
prescribing an optimum range for the dB that is the distance from
the lens mount portion to the image surface of the optical system,
in order to attain an overall balance between compactness and
performance of this interchangeable lens.
If the upper limit value in Conditional Expression #2-2 is
exceeded, then it is necessary to design a lens having a long back
focus, and as a result the total length of the lens is increased,
that is undesirable.
[0065] If the lower limit value in Conditional Expression #2-2 is
not attained, then it is necessary to shorten the back focus, and
as a result the exit pupil becomes short, and this is not
desirable. Moreover, undesirable constraints arise with regard to
ensuring the strength of the mounting members and arranging the
members and so on.
[0066] It should be understood that, in order to ensure the
benefits of the present invention, it is desirable to make the
upper limit value in Conditional Expression #2-2 be 18.3. Moreover,
in order further to ensure the benefits of the present invention,
it is desirable to make the upper limit value in Conditional
Expression #2-2 be 17.8. Yet further, in order even further to
ensure the benefits of the present invention, it is desirable to
make the upper limit value in Conditional Expression #2-2 be 17.3.
Furthermore, in order to ensure the benefits of the present
invention, it is desirable to make the lower limit value in
Conditional Expression #2-2 be 15.3. Moreover, in order further to
ensure the benefits of the present invention, it is desirable to
make the lower limit value in Conditional Expression #2-2 be 15.8.
Yet further, in order even further to ensure the benefits of the
present invention, it is desirable to make the lower limit value in
Conditional Expression #2-2 be 16.3.
[0067] It should be understood that, the distance dB from the lens
mount portion to the image surface of the optical system, the air
conversion length Bf, and the distance L upon the optical axis from
the lens mount portion to the lens surface closest to the image (in
case the lens mount portion 1a being taken as a reference, the
direction towards the image is considered positive and the
direction towards the object that is to be photographed is
considered negative) have a relationship of dB=Bf+L.
[0068] Conditional Expression #3 is a conditional expression for
prescribing an optimum range for the image circle D, in order to
attain an overall balance between compactness and performance of
this camera system.
[0069] If the upper limit value in Conditional Expression #3 is
exceeded, then designing an optical system that ensures a
sufficiently long exit pupil becomes difficult, and this is
undesirable. Moreover, as a result, the external diameter of the
lens barrel is undesirably increased.
[0070] If the lower limit value in Conditional Expression #3 is not
attained, then, while there is an advantage in terms of making the
system more compact, the refractive power of each of the lens
components included in the optical system becomes stronger, and
this is not desirable. When the refractive power becomes stronger,
the accuracy demanded for each of the lens components and for their
assembly becomes more severe, and as a result it becomes impossible
to provide satisfactory imaging performance, and this is very
undesirable.
[0071] It should be understood that, in order to ensure the
benefits of the present invention, it is desirable to make the
upper limit value in Conditional Expression #3 be 19.5. Moreover,
in order further to ensure the benefits of the present invention,
it is desirable to make the upper limit value in Conditional
Expression #3 be 19.0. Yet further, in order even further to ensure
the benefits of the present invention, it is desirable to make the
upper limit value in Conditional Expression #3 be 18.5. Still
further, in order yet further to ensure the benefits of the present
invention, it is desirable to make the upper limit value in
Conditional Expression #3 be 18.0. Moreover, in order even further
to ensure the benefits of the present invention, it is desirable to
make the upper limit value in Conditional Expression #3 be
17.5.
[0072] Furthermore, in order to ensure the benefits of the present
invention, it is desirable to make the lower limit value in
Conditional Expression #3 be 14.5. Moreover, in order further to
ensure the benefits of the present invention, it is desirable to
make the lower limit value in Conditional Expression #3 be 15.0.
Yet further, in order even further to ensure the benefits of the
present invention, it is desirable to make the lower limit value in
Conditional Expression #3 be 15.5.
[0073] Conditional Expression #4 is a conditional expression for
prescribing an appropriate range for the mechanical projection
amount L on the image side of the optical system included in the
interchangeable lens of this camera system.
[0074] If the upper limit value in Conditional Expression #4 is
exceeded, then the lens or a member that supports the lens or the
like may undesirably interfere with the camera body, and this is
difficult to correct.
[0075] It should be understood that, in order to ensure the
benefits of the present invention, it is desirable to make the
upper limit value in Conditional Expression #4 be 7.00. Moreover,
in order further to ensure the benefits of the present invention,
it is desirable to make the upper limit value in Conditional
Expression #4 be 4.50.
[0076] Furthermore, it is desirable for the distance L upon the
optical axis from the lens mount portion to the lens surface
closest to the image to satisfy the condition -140.0
mm.ltoreq.L.ltoreq.11.0 mm. By satisfying the lower limit value
condition, it is not necessary to provide an optical system which
has unnecessarily long exit pupil, and as a result the total length
of the optical system does not become long and becomes possible to
implement a lend in a compact.
[0077] Conditional Expressions #5 and #6 are conditional
expressions for ensuring that the flange back da and the radius of
circular portion at a maximum internal diameter part of the opening
portion of the lens mount portion rM are appropriate.
[0078] By satisfying these conditions, it becomes possible to
implement a lens of a high aperture ratio, and it also becomes
possible to implement a lens that can obtain a sufficient amount of
peripheral light.
[0079] It should be understood that, in order to ensure the
benefits of the present invention, it is desirable to make the
lower limit value in Conditional Expression #6 be 0.8. Moreover, in
order further to ensure the benefits of the present invention, it
is desirable to make the lower limit value in Conditional
Expression #6 be 1.0.
[0080] Conditional Expressions #5-2 and #6-2 are conditional
expressions for ensuring that the distance from the lens mount
portion to the image surface of the optical system dB and the
radius of circular portion at a maximum internal diameter part of
the opening portion of the lens mount portion rM are
appropriate.
[0081] By satisfying these conditions, it becomes possible to
implement a lens of a high aperture ratio, and it also becomes
possible to implement a lens that can obtain a sufficient amount of
peripheral light.
[0082] It should be understood that, in order to ensure the
benefits of the present invention, it is desirable to make the
lower limit value in Conditional Expression #6-2 be 0.8. Moreover,
in order further to ensure the benefits of the present invention,
it is desirable to make the lower limit value in Conditional
Expression #6-2 be 1.0.
[0083] Furthermore, with the present invention, in order to prevent
failure of photography due to image shaking originating in hand
shaking or the like, by combining a shake detection system that
detects shaking of the lens system and a drive means with the lens
system, and by driving all or a part of a single lens group among
the lens groups that make up the optical system off from the center
line so that it functions as a shift lens group, it is possible to
correct for image shaking by shifting the image by driving the
shift lens group with the drive means, so as to correct for image
shaking (fluctuation of the image surface position) originating in
shaking of the lens system detected by this shake detection system.
As described above, the image capturing lens of the present
invention can function as a so called anti-vibration optical
system.
[0084] Moreover, with the present invention, in order to prevent
failure of photography due to image shaking originating in hand
shaking or the like, by combining a shake detection system that
detects shaking of the camera and the lens and a drive means with
the imaging element (image sensor), and by driving all or a part of
a member included in the imaging element (image sensor) and
shifting it off from the center line, it is possible to correct for
image shaking by shifting the image by driving the member included
in the imaging element (image sensor) with the drive means, so as
to correct for image shaking (fluctuation of the image surface
position) originating in shaking of the camera and the lens
detected by this shake detection system. As described above, the
camera system of the present invention can function as a so called
anti-vibration system.
[0085] Furthermore, in the various embodiments of the present
invention, it would also be possible to add other lens groups
between the lens groups, or to add other lens groups to the lens
system proximate to the image side or to the side of the object to
be photographed.
[0086] It should be understood that the following details may be
employed appropriately, within the range in which the optical
performance is not deteriorated.
First, it would also be acceptable to employ aspherical surfaces
for the lens surfaces. In this case any type of aspherical surface
may be used, such as for example an aspherical surface formed by a
grinding process, a molded glass aspherical surface that is formed
into an aspherical surface shape by glass molding, or a compound
type aspherical surface that is made by forming resin into an
aspherical surface upon a glass surface.
[0087] Moreover, it would also be possible to make the lens surface
as a diffraction surface, or to make the lens as a gradient index
lens (i.e. a GRIN lens) or as a plastic lens.
[0088] Yet further, by implementing an antireflection coating
having high transmittance over a wide wavelength region upon each
of the lens surfaces, it is possible to attain a high optical
performance with high contrast while alleviating flaring and
ghosting.
[0089] The image capture lens systems according to the embodiments
of the present invention include, in order from the object to be
photographed, lens components that constitute an interchangeable
lens, a filter group FL disposed within the camera body including a
low pass filter and/or an infra-red cutout filter and so on, and a
light reception surface of an imaging element (image sensor) I.
[0090] Furthermore, during change of the focal state from a focused
state at infinity to a focused state at close range (in other
words, focusing), focusing is performed by shifting some lens
component along the direction of the optical axis.
[0091] In the embodiments, if the height in the direction
perpendicular to the optical axis is termed y, the distance along
the optical axis (i.e. the sag amount) from the contact plane of
the vertex of aspherical surface at the height y to aspherical
surface is termed S(y), the radius of curvature of a reference
spherical surface (i.e. the paraxial radius of curvature) is termed
r, the conical constant is termed x, and the n-th order aspherical
surface coefficient is termed An, then the aspherical surfaces are
given by the following Equation:
S(y)=(y.sup.2/r)/{1+(1-.kappa..times.y.sup.2/r.sup.2).sup.1/2}+A4.times.-
y.sup.4+A6.times.y.sup.6+A8.times.y.sup.8+A10.times.y.sup.10
Equation (a).
[0092] It should be understood that, in these embodiments, the
secondary aspherical surface coefficient A2 is 0. In the tables for
the various embodiments, an asterisk is prefixed to the surface
numbers of aspherical surfaces.
The First Embodiment
[0093] FIG. 3 is a figure showing the structure of an image capture
lens system according to a first embodiment of the present
invention. The optical system of this interchangeable lens 1 of
FIG. 3 is a zoom lens of a two-group structure incorporating a
first lens group G1 and a second lens group G2, and furthermore the
second lens group G2 incorporates a 2a-th lens group G2a and a
2b-th lens group G2b.
[0094] The first lens group G1 includes a first lens component L1
that is a negative meniscus lens whose convex surface faces towards
the object to be photographed, a second lens component L2 that is a
negative meniscus lens whose convex surface faces towards the
object to be photographed, and a third lens component L3 that is a
positive meniscus lens whose convex surface faces towards the
object to be photographed.
[0095] The 2a-th lens group G2a is made as a cemented lens in which
a fourth lens L4 that is a negative meniscus lens whose convex
surface faces the object to be photographed and a fifth lens L5
that is a biconvex lens are glued together.
[0096] And the 2b-th lens group G2b includes a sixth lens component
L6 that is a positive meniscus lens whose convex surface faces
towards the object to be photographed, a cemented lens in which a
seventh lens component L7 that is a biconcave lens and an eighth
lens component L8 that is a biconvex lens are glued together, a
cemented lens in which a ninth lens component L9 that is a biconvex
lens and a tenth lens component L10 that is a biconcave lens are
cemented together, and an eleventh lens component L11 that is a
biconvex lens.
[0097] Furthermore, a filter group FL includes a low pass filter
and an infra-red cutoff filter and so on.
[0098] A light reception surface of an imaging element (image
sensor) not shown in the figures constitutes an image surface I,
with this imaging element (image sensor) being a solid imaging
element (image sensor) such as a CCD or a CMOS or the like (and the
same holds for the subsequent embodiments).
[0099] Moreover, an aperture stop S is disposed within the second
lens group G2, and is fixed with respect to the image surface
during focusing from the infinity state to the close-up state.
[0100] The values specified in this first embodiment of the present
invention are displayed in the following Table 1. In Table 1, f is
the focal length, F-number is the F number, and 2.omega. is the
field angle. Moreover, the surface number is the number in order of
the lens surface from the object to be photographed along the
direction of travelling of the light rays, while the refractive
index and the Abbe number are the values for d line (.lamda.=587.6
nm). Here, while the units used in the specification values below
for focal length f, radius of curvature r, and surface gap d are in
general "mm", this is not to be considered as being limitative,
since the optical system will provide the same optical performance
even if its overall size is proportionally increased or decreased.
It should be understood that a radius of curvature of 0.0000
denotes a plane, and that the refractive index of air is omitted
since it is 1.00000.
TABLE-US-00001 TABLE 1 wide angle intermediate telephoto end focal
length end f = 10.30 ~ 18.75 ~ 29.10 F-number = 3.64 ~ 4.58 ~ 5.85
2.omega. = 78.99 ~ 46.54 ~ 30.69 image height = 7.96 ~ 7.96 ~ 7.96
lens total length = 75.01 ~ 68.45 ~ 73.01 air conversion length Bf
= 20.01 ~ 29.36 ~ 40.81 surface surface number radius of curvature
gap refractive index Abbe number 1 25.1496 1.80 1.77377 47.17 *2
8.2125 5.45 3 196.3246 0.80 1.75500 52.32 4 27.6871 1.30 5 16.4584
2.40 1.84666 23.78 6 32.8415 (d6) 7 48.1525 0.80 1.80810 22.76 8
29.9255 1.90 1.65160 58.55 9 -48.2103 (d9) 10 9.6852 1.95 1.60300
65.44 11 25.9987 1.00 12 0.0000 1.30 (aperture stop S) 13
-2813.1247 0.80 1.82080 42.71 *14 16.7458 0.60 15 0.0000 1.15 16
20.3251 1.75 1.49700 81.54 17 -90.6835 0.80 1.83400 37.16 18
17.5678 0.45 19 12.4017 2.15 1.66910 55.42 *20 -71.9576 (d20) 21
0.0000 1.00 1.51680 64.10 22 0.0000 2.13 23 0.0000 1.87 1.51680
64.10 24 0.0000 0.30 25 0.0000 0.70 1.51680 64.10 26 0.0000 0.50
focal length of each lens group group first surface focal length 1
1 -18.1260 2 7 20.0528
[0101] In this first embodiment of the present invention, the lens
surfaces for the second surface, the fourteenth surface, and the
twentieth surface are formed as aspherical surfaces. The data for
these aspherical surfaces, in other words the values of their
vertex radiuses of curvature R, their conic constants .kappa., and
their aspherical surface constants A4 through A10 are shown in the
following Table 2.
TABLE-US-00002 TABLE 2 R .kappa. A4 A6 A8 A10 The second surface
8.2125 +0.6130 +1.9235 .times. 10.sup.-5 +1.4500 .times. 10.sup.-7
+1.3915 .times. 10.sup.-9 +1.5970 .times. 10.sup.-12 The fourteenth
surface 16.7458 +0.1364 -3.4025 .times. 10.sup.-5 +1.6024 .times.
10.sup.-6 -2.106210 .times. 10.sup.-7 +7.1555 .times. 10.sup.-9 The
twentieth surface -71.9576 -8.5090 +2.4560 .times. 10.sup.-4
+2.7700 .times. 10.sup.-6 -3.1700 .times. 10.sup.-8 +4.6515 .times.
10.sup.-10
[0102] In this first embodiment of the present invention, the air
gap d6 on the optical axis between the first lens group G1 and the
second lens group G2, the air gap d9 on the optical axis between
the 2a-th lens group G2a and the 2b-th lens group G2b, and the air
gap d20 on the optical axis between the second lens group G2 and
the filter group FL are changed during zooming. The variable gaps
during focusing at infinity when the focal length is set to the
wide angle end state, the intermediate focal length state, and the
telephoto end state are shown in the following Table 3.
TABLE-US-00003 TABLE 3 wide angle end intermediate focal length
telephoto end f 10.3000 18.7500 29.1000 d6 23.8068 7.9033 1.0085 d9
3.5766 3.5766 3.5766 d20 14.7252 24.0734 35.5235
[0103] The values corresponding to each of the conditional
expressions in this first embodiment of the present invention are
shown in the next Table (4).
TABLE-US-00004 TABLE 4 da = 18.0000 TLw = 75.0086 .SIGMA.dw =
53.7834 Ymax = 7.9600 F-number w = 3.6380 F-number m = 4.5812
F-number t = 5.8528 Conditional Expression #1 2rM = 27.0
Conditional Expression #2 da = 18.0000 Conditional Expression #2-2
dB = 16.7836 Conditional Expression #3 D = 15.9200 Conditional
Expression #4 L = -3.2252 (wide angle end) Conditional Expression
#5 (2 rM/da = 1.50) 1.50 .gtoreq. 1/3.638, 1/4.5812, 1/5.8528
Conditional Expression #5-2 (2 rM/dB = 1.6087) 1.6087 .gtoreq.
1/3.638, 1/4.5812, 1/5.8528
The Second Embodiment
[0104] FIG. 4 is a figure showing the structure of an image capture
lens system according to a second embodiment of the present
invention. The optical system of this interchangeable lens 1 of
FIG. 4 is a zoom lens of a three-group structure incorporating a
first lens group G1, a second lens group G2, and a third lens group
G3, and furthermore the first lens group G1 incorporates a 1a-th
lens group G1a and a 1b-th lens group G1b. The 1a-th lens group G1a
is made as a cemented lens in which a first lens L1 that is a
negative meniscus lens whose convex surface faces the object to be
photographed and a second lens L2 that is a biconvex lens are glued
together.
[0105] And the 1b-th lens group G1b includes a third lens component
L3 that is a positive meniscus lens whose convex surface faces
towards the object to be photographed.
[0106] And the second lens group G2 includes a fourth lens
component L4 that is a biconcave lens, a cemented lens in which a
fifth lens component L5 that is a biconcave lens and a sixth lens
component L6 that is a positive meniscus lens whose convex surface
faces towards the object to be photographed are glued together, and
a seventh lens component L7 that is a biconcave lens.
[0107] Moreover, the third lens group G3 includes an eighth lens
component L8 that is a biconvex lens, a cemented lens in which a
ninth lens component L9 that is a biconvex lens and a tenth lens
component L10 that is a biconcave lens are glued together, an
eleventh lens component L11 that is a biconvex lens, a cemented
lens in which a twelfth lens component L12 that is a biconcave lens
and a thirteenth lens component L13 that is a biconvex lens are
glued together, and a fourteenth lens component L14 that is a
negative meniscus lens whose concave surface faces towards the
image.
[0108] Furthermore, a filter group FL includes a low pass filter
and an infra-red cutoff filter and so on.
[0109] Moreover, an aperture stop S is disposed between the second
lens group G2 and the third lens group G3, and is fixed with
respect to the image surface of the second lens group G2 or the
third lens group G3 during focusing from the infinity state to the
close-up state.
[0110] The values specified in this second embodiment of the
present invention are displayed in the following Table 5. In Table
5, f is the focal length, F-number is the F number, and 2.omega. is
the field angle. Moreover, the surface number is the number in
order of the lens surface from the object to be photographed along
the direction of travelling of the light rays, while the refractive
index and the Abbe number are the values for d line (.lamda.=587.6
nm). Here, while the units used in the specification values below
for focal length f, radius of curvature r, and surface gap d are in
general "mm", this is not to be considered as being limitative,
since the optical system will provide the same optical performance
even if its overall size is proportionally increased or decreased.
It should be understood that a radius of curvature of 0.0000
denotes a plane, and that the refractive index of air is omitted
since it is 1.00000.
TABLE-US-00005 TABLE 5 tele- wide intermediate photo angle end
focal length end f = 30.00 ~ 65.50 ~ 107.09 F-number = 4.14 ~ 4.85
~ 5.75 2.omega. = 31.89 ~ 14.24 ~ 8.79 image height = 8.50 ~ 8.50 ~
8.50 lens total length = 76.00 ~ 95.28 ~ 105.00 air conversion
length Bf = 21.57 ~ 26.99 ~ 34.74 surface radius number of
curvature surface gap refractive index Abbe number 1 346.7451 0.95
1.83400 37.16 2 54.0425 3.00 1.49782 82.52 3 -63.5775 (d3) 4
36.4849 2.35 1.49782 82.52 5 474.1283 (d5) 6 -81.0984 0.80 1.69680
55.53 7 35.2884 0.85 8 -45.4861 0.80 1.69680 55.53 9 15.4621 2.20
1.84666 23.78 10 242.8730 0.95 11 -19.8007 0.80 1.72916 54.68 12
405.4435 (d12) 13 0.0000 0.50 (aperture stop S) 14 348.1094 2.15
1.60311 60.64 15 -21.6711 0.10 16 18.4392 3.30 1.49782 82.52 17
-15.2984 0.80 1.80384 33.89 18 95.0246 0.10 19 14.4846 2.70 1.60300
65.44 20 -68.6868 8.55 21 -28.4844 0.80 1.74399 44.79 22 6.8364
3.75 1.61293 37.00 23 -14.9063 0.84 24 -8.3732 1.15 1.78800 47.37
25 -15.0720 (d25) 26 0.0000 1.00 1.51680 64.12 27 0.0000 1.50 28
0.0000 1.87 1.51680 64.12 29 0.0000 0.40 30 0.0000 0.70 1.51680
64.12 31 0.0000 0.50 focal length of each lens group group first
surface focal length 1 1 60.3701 2 6 -12.2950 3 14 14.4853
[0111] In this second embodiment of the present invention, the air
gap d3 on the optical axis between the 1a-th lens group G1a and the
1b-th lens group G1b, the air gap d5 on the optical axis between
the first lens group G1 and the second lens group G2, the air gap
d12 on the optical axis between the second lens group G2 and the
third lens group G3, and the air gap d25 on the optical axis
between the third lens group G3 and the filter group FL are changed
during zooming. The variable gaps during focusing at infinity when
the focal length is set to the wide angle end state, the
intermediate focal length state, and the telephoto end state are
shown in the following Table 6.
TABLE-US-00006 TABLE 6 wide angle end intermediate focal length
telephoto end f 30.0001 65.5002 107.0905 d3 4.1293 4.1293 4.1293 d5
2.0000 20.3065 25.6415 d12 9.6402 5.2156 1.8304 d25 16.8184 22.2346
29.9867
[0112] The values corresponding to each of the conditional
expressions in this second embodiment of the present invention are
shown in the next Table (7).
TABLE-US-00007 TABLE 7 da = 17.0000 TLw = 76.0001 .SIGMA.dw =
53.2116 Ymax = 8.5000 F-number w = 4.1735 F-number m = 4.8232
F-number t = 5.7441 Conditional Expression #1 2rM = 33.0
Conditional Expression #2 da = 17.0 Conditional Expression #2-2 dB
= 15.7836 Conditional Expression #3 D = 17.0 Conditional Expression
#4 L = -5.7885 (wide angle end) Conditional Expression #5 (2 rM/da
= 1.9412) 1.9412 .gtoreq. 1/4.1735, 1/4.8232, 1/5.7441 Conditional
Expression #5-2 (2 rM/dB = 2.0908) 2.0908 .gtoreq. 1/4.1735,
1/4.8232, 1/5.7441
The Third Embodiment
[0113] FIG. 5 is a figure showing the structure of an image capture
lens system according to a third embodiment of the present
invention. The optical system of this interchangeable lens 1 of
FIG. 5 is a single focus lens incorporating a first lens group G1
and a second lens group G2.
[0114] The first lens group G1 includes a first lens component L1
that is a negative meniscus lens whose convex surface faces towards
the object to be photographed, a second lens component L2 that is a
negative meniscus lens whose convex surface faces towards the
object to be photographed, and a third lens component L3 that is a
biconvex lens.
[0115] And the second lens group G2 includes a cemented lens in
which a fourth lens component L4 that is a biconcave lens and an
fifth lens component L5 that is a biconvex lens are glued together,
and a sixth lens component L6 that is a biconvex lens.
[0116] Furthermore, a filter group FL includes a low pass filter
and an infra-red cutoff filter and so on.
[0117] Moreover, an aperture stop S is disposed between the first
lens group G1 and the second lens group G2, and is fixed with
respect to the image surface during focusing from the infinity
state to the close-up state.
[0118] The values specified in this third embodiment of the present
invention are displayed in the following Table 8. In Table 8, f is
the focal length, F-number is the F number, and 2.omega. is the
field angle. Moreover, the surface number is the number in order of
the lens surface from the object to be photographed along the
direction of travelling of the light rays, while the refractive
index and the Abbe number are the values for d line (.lamda.=587.6
nm). Here, while the units used in the specification values below
for focal length f, radius of curvature r, and surface gap d are in
general "mm", this is not to be considered as being limitative,
since the optical system will provide the same optical performance
even if its overall size is proportionally increased or decreased.
It should be understood that a radius of curvature of 0.0000
denotes a plane, and that the refractive index of air is omitted
since it is 1.00000.
TABLE-US-00008 TABLE 8 f = 10.60 F-number = 2.87 2.omega. = 76.93
image height = 8.19 total length = 35.98 air conversion length Bf =
14.71 surface radius of number curvature surface gap refractive
index Abbe number 1 11.6151 1.10 1.69350 53.20 *2 5.8232 2.50 3
39.6894 1.20 1.67790 55.34 4 19.5461 1.20 5 13.5252 2.75 1.90366
31.31 6 -336.4314 0.25 7 0.0000 1.55 8 0.0000 (d8) (aperture stop
S) 9 0.0000 1.25 10 -6.0487 0.95 1.80518 25.42 11 1661.0055 2.80
1.75500 52.32 12 -7.1834 0.20 13 23.0502 2.75 1.59201 67.02 *14
-17.3125 (d14) 15 0.0000 1.00 1.51633 64.14 16 0.0000 5.73 17
0.0000 1.87 1.51633 64.14 18 0.0000 0.30 19 0.0000 0.70 1.51633
64.14 20 0.0000 0.48 focal length of each lens group group first
surface focal length 1 1 106.9661 2 10 13.0930
[0119] In this third embodiment of the present invention, the lens
surfaces for the second surface and the fourteenth surface are
formed as aspherical surfaces. The data for these aspherical
surfaces, in other words the values of their vertex radiuses of
curvature R, their conic constants .kappa., and their aspherical
surface constants A4 through A10 are shown in the following Table
9.
TABLE-US-00009 TABLE 9 R .kappa. A4 A6 A8 A10 The second surface
5.8232 +0.2484 +2.8541 .times. 10.sup.-4 +5.1153 .times. 10.sup.-6
+6.0420 .times. 10.sup.-9 +2.4456 .times. 10.sup.-9 The fourteenth
surface -17.3125 -19.0000 -2.8224 .times. 10.sup.-4 +9.8015 .times.
10.sup.-6 -1.4878 .times. 10.sup.-7 +1.1010 .times. 10.sup.-9
[0120] In this third embodiment of the present invention, the air
gap d8 on the optical axis between the aperture stop S and the
second lens group G2 and the air gap d14 on the optical axis
between the second lens group G2 and the filter group FL are
changed during focusing. These variable gaps during the infinity
focused state and the close-up focused state are shown in the
following Table 10. It should be understood that the close-up
distance is a photographic distance of 0.5 m.
TABLE-US-00010 TABLE 10 infinity focused state close-up focused
state d2 1.5591 1.3171 d14 5.8409 6.0829
[0121] The values corresponding to each of the conditional
expressions in this third embodiment of the present invention are
shown in the following Table (11).
TABLE-US-00011 TABLE 11 da = 18.5000 TLw = 35.9826 .SIGMA.dw =
20.0591 Ymax = 8.1900 F-number = 2.8685 Conditional Expression #1
2rM = 18.0 Conditional Expression #2 da = 18.5 Conditional
Expression #2-2 dB = 17.2836 Conditional Expression #3 D = 16.38
Conditional Expression #4 L = 2.5765 Conditional Expression #5 (2
rM/da = 0.9730) 0.9730 .gtoreq. 1/2.8685 Conditional Expression
#5-2 (2 rM/dB = 1.0414) 1.0414 .gtoreq. 1/2.8685
The Fourth Embodiment
[0122] FIG. 6 is a figure showing the structure of an image capture
lens system according to a fourth embodiment of the present
invention. The optical system of this interchangeable lens 1 of
FIG. 6 is a single focus lens incorporating a first lens group G1
and a second lens group G2.
[0123] The first lens group G1 includes a first lens component L1
that is a positive meniscus lens whose convex surface faces the
object to be photographed, a second lens component L2 that is a
positive meniscus lens whose convex surface faces the object to be
photographed, a third lens component L3 that is a positive meniscus
lens whose convex surface faces the object to be photographed, a
fourth lens component L4 that is a negative meniscus lens whose
convex surface faces the object to be photographed, a cemented lens
in which a fifth lens component L5 that is a biconcave lens and a
sixth lens component L6 that is a biconvex lens are glued together,
and a seventh lens component L7 that is a biconvex lens.
[0124] And the second lens group G2 includes a cemented lens in
which an eighth lens component L8 that is a biconvex lens and a
ninth lens component L9 that is a biconcave lens are glued
together.
[0125] Furthermore, a filter group FL includes a low pass filter
and an infra-red cutoff filter and so on.
[0126] Moreover, an aperture stop S is provided within the first
lens group G1, and is movable together with the first lens group G1
during focusing from the infinity state to the close-up state.
[0127] The values specified in this fourth embodiment of the
present invention are displayed in the following Table 12. In Table
12, f is the focal length, F-number is the F number, and 2.omega.
is the field angle. Moreover, the surface number is the number in
order of the lens surface from the object to be photographed along
the direction of travelling of the light rays, while the refractive
index and the Abbe number are the values for d line (.lamda.=587.6
nm). Here, while the units used in the specification values below
for focal length f, radius of curvature r, and surface gap d are in
general "mm", this is not to be considered as being limitative,
since the optical system will provide the same optical performance
even if its overall size is proportionally increased or decreased.
It should be understood that a radius of curvature of 0.0000
denotes a plane, and that the refractive index of air is omitted
since it is 1.00000.
TABLE-US-00012 TABLE 12 f = 32.00 F-number = 1.23 2.omega. = 29.36
image height = 8.35 total length = 56.12 air conversion length Bf =
12.63 surface radius number of curvature surface gap refractive
index Abbe number 1 35.1646 5.50 1.59319 67.87 2 329.7297 0.30 3
22.4968 4.30 1.59319 67.87 4 61.9156 0.20 5 21.5844 5.10 1.81600
46.62 6 21.8900 1.30 7 57.6030 1.30 1.67270 32.10 8 10.5222 4.90 9
0.0000 4.00 (aperture stop S) 10 -11.2286 1.30 1.69895 30.13 11
56.3405 4.35 1.88300 40.76 12 -19.0163 0.15 13 583.7537 2.85
1.75500 52.32 14 -32.8762 (d14) 15 40.5457 4.30 1.88300 40.76 16
-30.1051 1.40 1.76182 26.52 17 881.0656 (d17) 18 0.0000 0.50
1.51680 64.10 19 0.0000 4.60 20 0.0000 1.87 1.51680 64.10 21 0.0000
0.30 22 0.0000 0.70 1.51680 64.10 23 0.0000 0.50 focal length of
each lens group group first surface focal length 1 1 51.8852 2 15
40.3248
[0128] In this fourth embodiment of the present invention, the air
gap d14 on the optical axis between the first lens group G1 and the
second lens group G2 and the air gap d17 on the optical axis
between the second lens group G2 and the filter group FL are
changed during focusing. These variable gaps during the infinity
focused state and the close-up focused state are shown in the
following Table 13. It should be understood that the close-up
distance is a photographic distance of 0.5 m.
TABLE-US-00013 TABLE 13 infinity focused state close-up focused
state d14 1.2000 3.2351 d17 5.2048 6.8141
[0129] The values corresponding to each of the conditional
expressions in this fourth embodiment of the present invention are
shown in the following Table (14).
TABLE-US-00014 TABLE 14 da = 18.0000 TLw = 56.1248 .SIGMA.dw =
42.4500 Ymax = 8.3500 F-number = 1.2344 Conditional Expression #1
2rM = 30.0 Conditional Expression #2 da = 18.0 Conditional
Expression #2-2 dB = 16.9540 Conditional Expression #3 D = 16.7000
Conditional Expression #4 L = 4.3252 Conditional Expression #5 (2
rM/da = 1.6667) 1.6667 .gtoreq. 1/1.2344 Conditional Expression
#5-2 (2 rM/dB = 1.7695) 1.7695 .gtoreq. 1/1.2344
The Fifth Embodiment
[0130] FIG. 7 is a figure showing the structure of an image capture
lens system according to a fifth embodiment of the present
invention. The optical system of this interchangeable lens 1 of
FIG. 7 is a zoom lens of a two-group structure incorporating a
first lens group G1 and a second lens group G2, and furthermore the
second lens group G2 incorporates a 2a-th lens group G2a and a
2b-th lens group G2b.
[0131] The first lens group G1 includes a first lens component L1
that is a negative meniscus lens whose convex surface faces towards
the object to be photographed, a second lens component L2 that is a
biconcave lens, and a third lens component L3 that is a positive
meniscus lens whose convex surface faces towards the object to be
photographed. The 2a-th lens group G2a is a fourth lens component
that is a convex meniscus lens.
[0132] And the 2b-th lens group G2b includes a cemented lens in
which a fifth lens component L5 that is a biconvex lens and a sixth
lens component L6 that is a negative meniscus lens whose convex
surface faces towards the image are glued together, a cemented lens
in which a seventh lens component L7 that is a negative meniscus
lens whose convex surface faces towards the object to be
photographed and an eighth lens component L8 that is a biconvex
lens are glued together, a ninth lens component L9 that is a
positive meniscus lens whose convex surface faces the image, and a
tenth lens component L10 that is a negative meniscus lens whose
convex surface faces the image.
[0133] Furthermore, a filter group FL includes a low pass filter
and an infra-red cutoff filter and so on.
[0134] Moreover, an aperture stop S is disposed between the 2a-th
lens group G2a and the 2b-th lens group G2b, and is fixed with
respect to the image surface of the 2a-th lens group G2a or the
2b-th lens group G2b during focusing from the infinity state to the
close-up state.
[0135] The values specified in this fifth embodiment of the present
invention are displayed in the following Table 15. In Table 15, f
is the focal length, F-number is the F number, and 2.omega. is the
field angle. Moreover, the surface number is the number in order of
the lens surface from the object to be photographed along the
direction of travelling of the light rays, while the refractive
index and the Abbe number are the values for d line (.lamda.=587.6
nm). Here, while the units used in the specification values below
for focal length f, radius of curvature r, and surface gap d are in
general "mm", this is not to be considered as being limitative,
since the optical system will provide the same optical performance
even if its overall size is proportionally increased or decreased.
It should be understood that a radius of curvature of 0.0000
denotes a plane, and that the refractive index of air is omitted
since it is 1.00000.
TABLE-US-00015 TABLE 15 tele- wide angle intermediate photo end
focal length end f = 6.90 ~ 9.50 ~ 12.61 F-number = 3.63 ~ 4.53 ~
5.77 2.omega. = 98.32 ~ 78.98 ~ 63.34 image height = 7.85 ~ 7.85 ~
7.85 lens total length = 71.57 ~ 69.91 ~ 71.31 air conversion
length Bf = 14.66 ~ 19.25 ~ 24.74 surface radius number of
curvature surface gap refractive index Abbe number *1 66.1237 1.90
1.76802 49.23 *2 11.2811 10.60 3 -42.1432 3.20 1.76802 49.23 *4
17.4513 3.80 5 14.5546 2.40 1.92286 20.88 6 23.1839 (d6) 7 13.2265
1.50 1.75500 52.32 8 37.9949 (d8) 9 0.0000 1.50 (aperture stop S)
10 21.7513 6.50 1.49782 82.56 11 -9.3721 1.00 1.88300 40.77 12
-49.7827 1.66 13 11.8579 1.20 1.90366 31.31 14 7.9982 2.50 1.49782
82.56 15 -992.9794 1.21 16 -5546.2137 1.80 1.49782 82.56 17
-17.2843 0.40 1.00000 18 -13.7933 1.20 1.76802 49.23 *19 -21.3660
(d19) 20 0.0000 0.50 1.51633 64.14 21 0.0000 4.60 22 0.0000 1.87
1.51633 64.14 23 0.0000 0.30 24 0.0000 0.70 1.51633 64.14 25 0.0000
0.50 focal length of each lens group group first surface focal
length 1 1 -9.4458 2 7 16.6813
[0136] In this fifth embodiment of the present invention, the lens
surfaces for the first surface, the second surface, the fourth
surface, and the nineteenth surface are formed as aspherical
surfaces. The data for these aspherical surfaces, in other words
the values of their vertex radiuses of curvature R, their conic
constants x, and their aspherical surface constants A4 through A10
are shown in the following Table 16.
TABLE-US-00016 TABLE 16 R .kappa. A4 A6 A8 A10 The first surface
66.1237 +11.2700 +6.5215 .times. 10.sup.-6 +4.5152 .times.
10.sup.-9 +0.0000 +0.0000 The second surface 11.2811 -0.6593
+0.0000 +0.0000 +0.0000 +0.0000 The fourth surface 17.4513 +2.7400
+1.5435 .times. 10.sup.-4 +3.8190 .times. 10.sup.-7 +0.0000 +0.0000
The nineteenth surface -21.3661 -21.6872 -1.3545 .times. 10.sup.-4
+5.0740 .times. 10.sup.-6 -6.2302 .times. 10.sup.-8 +0.0000
[0137] In this fifth embodiment of the present invention, the air
gap d6 on the optical axis between the first lens group G1 and the
second lens group G2, the air gap d8 on the optical axis between
the 2a-th lens group G1a and the aperture stop S, and the air gap
d19 on the optical axis between the second lens group G2 and the
filter group FL are changed during zooming. The variable gaps
during focusing at infinity when the focal length is set to the
wide angle end state, the intermediate focal length state, and the
telephoto end state are shown in the following Table 17.
TABLE-US-00017 TABLE 17 wide angle end intermediate focal length
telephoto end f 6.9000 9.5000 12.6100 d6 12.1174 5.8676 1.7770 d8
1.3806 1.3806 1.3806 d19 7.2339 11.8255 17.3178
[0138] The values corresponding to each of the conditional
expressions in this fifth embodiment of the present invention are
shown in the following Table 18.
TABLE-US-00018 TABLE 18 da = 17.5000 TLw = 71.5698 .SIGMA.dw =
55.8659 Ymax = 7.8500 F-number w = 3.6257 F-number m = 4.5272
F-number t = 5.7719 Conditional Expression #1 2rM = 21.8
Conditional Expression #2 da = 17.50 Conditional Expression #2-2 dB
= 16.4540 Conditional Expression #3 D = 15.7000 Conditional
Expression #4 L = 1.7961 (wide angle end) Conditional Expression #5
(2 rM/da = 1.2457) 1.2457 .gtoreq. 1/3.6257, 1/4.5272, 1/5.7719
Conditional Expression #5-2 (2 rM/dB = 1.3249) 1.3249 .gtoreq.
1/3.6257, 1/4.5272, 1/5.7719
[0139] In the following, for the above first through fifth
embodiments, the values of Conditional Expression #1 through
Conditional Expression #6 are shown all together. Here, the symbol
".smallcircle." is shown when Conditional Expression #5 is
satisfied.
TABLE-US-00019 Conditional Expressions #5 #1 #2 #3 #4 2rM/da
.gtoreq. 1/ #6 2rM da D L F-number 2rM/da first 27.0 18.0 15.92
-3.2252 .largecircle. 1.50 embodiment second 33.0 17.0 17.00
-5.7885 .largecircle. 1.9412 embodiment third 18.0 18.5 16.38
2.5765 .largecircle. 0.9730 embodiment fourth 30.0 18.0 16.70
4.3252 .largecircle. 1.6667 embodiment fifth 21.8 17.5 15.70 1.7961
.largecircle. 1.2457 embodiment
[0140] It is preferable that the lens mount forming in the present
invention is done by various process, e.g. machining as lathe
turning or other cutting process, die-casting, injection molding
and the like.
[0141] It should be understood that the present invention is not to
be considered as being limited in any way by the structures
described above with respect to the disclosed embodiments, provided
that the essential technical functions of the present invention are
not lost. Moreover, it would also be acceptable to arrange to
combine the above described embodiments and variant embodiments
thereof.
* * * * *