U.S. patent application number 09/749566 was filed with the patent office on 2001-07-12 for binoculars and optical device provided with via-rotation-drawable type eye cup.
This patent application is currently assigned to NIKON CORPORATION. Invention is credited to Aikawa, Yasuyuki.
Application Number | 20010007514 09/749566 |
Document ID | / |
Family ID | 18532683 |
Filed Date | 2001-07-12 |
United States Patent
Application |
20010007514 |
Kind Code |
A1 |
Aikawa, Yasuyuki |
July 12, 2001 |
Binoculars and optical device provided with via-rotation-drawable
type eye cup
Abstract
Binoculars includes a pair of lens barrel bodies and a pair of
eyepiece portions. At least one of the pair of eyepiece portions is
provided with an eyepiece frame fixed on one of the lens barrel
bodies, a plurality of eyepiece lenses, a diopter adjusting portion
that moves all of the plurality of eyepiece lenses by the same
movement amount in an optical axis direction, and a
via-rotation-drawable type eye cup portion. The diopter adjusting
portion includes a cam pin fixed relative to the eyepiece frame and
a diopter ring that is guided by the cam pin in the optical axis
direction by rotating of the diopter ring around an optical axis to
move all of the plurality of eyepiece lenses in the optical axis
direction. The eye cup portion includes a cylindrical eye cup
member that is rotatively disposed at an outer side of the diopter
ring and is guided by the cam pin in the optical axis direction by
rotating of the cylindrical eye cup member around the optical axis
to move the eye cup portion in the optical direction.
Inventors: |
Aikawa, Yasuyuki;
(Kawasaki-shi, JP) |
Correspondence
Address: |
Oliff & Berridge PLC
P.O. Box 19928
Alexandria
VA
22320
US
|
Assignee: |
NIKON CORPORATION
|
Family ID: |
18532683 |
Appl. No.: |
09/749566 |
Filed: |
December 28, 2000 |
Current U.S.
Class: |
359/823 ;
359/819; 359/822 |
Current CPC
Class: |
G02B 23/16 20130101;
G02B 23/00 20130101 |
Class at
Publication: |
359/823 ;
359/822; 359/819 |
International
Class: |
G02B 007/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 12, 2000 |
JP |
2000-003799 |
Claims
What is claimed is:
1. Binoculars comprising: a pair of lens barrel bodies; a pair of
eyepiece portions; at least one of said pair of eyepiece portions
being provided with an eyepiece frame fixed on one of said lens
barrel bodies, a plurality of eyepiece lenses, a diopter adjusting
portion that moves all of said plurality of eyepiece lenses by the
same movement amount in an optical axis direction, and a
via-rotation-drawable type eye cup portion; said diopter adjusting
portion including a cam pin fixed relative to said eyepiece frame
and a diopter ring that is guided by said cam pin in the optical
axis direction by rotating of the diopter ring around an optical
axis to move all of said plurality of eyepiece lenses in the
optical axis direction; and said eye cup portion including a
cylindrical eye cup member that is rotatively disposed at an outer
side of said diopter ring and is guided by said cam pin in the
optical axis direction by rotating of the cylindrical eye cup
member around the optical axis to move said eye cup portion in the
optical direction.
2. Binoculars according to claim 1, wherein said at least one of
said pair of right and left eyepiece portions is further provided
with a zooming portion that moves at least one of said plurality of
eyepiece lenses in the optical axis direction for zooming.
3. Binoculars according to claim 1, wherein a second cylindrical
member is fixedly disposed, between said diopter ring and said
cylindrical eye cup member, relative to said eyepiece frame, said
diopter ring rotates while sliding along the inner surface of said
second cylindrical member, and said cylindrical eye cup member
rotates while sliding along the outer surface of said second
cylindrical member.
4. Binoculars according to claim 1, wherein said diopter ring has a
spiral slot that engages with said cam pin to be guided in the
optical axis direction, and said cylindrical eye cup member has a
spiral slot that engages with said cam pin to be guided in the
optical axis direction.
5. Binoculars according to claim 1, wherein said eye cup portion
includes an elastic member that covers said cylindrical eye cup
member.
6. An optical device comprising: a pair of lens barrel bodies; a
pair of eyepiece portions; at least one of said pair of eyepiece
portions being provided with an eyepiece frame fixed on one of said
lens barrel bodies, a plurality of eyepiece lenses, a diopter
adjusting portion that moves all of said plurality of eyepiece
lenses by the same movement amount in an optical axis direction,
and a via-rotation-drawable type eye cup portion; said diopter
adjusting portion including a cam pin fixed relative to said
eyepiece frame and a diopter ring that is guided by said cam pin in
the optical axis direction by rotating of the diopter ring around
an optical axis to move all of said plurality of eyepiece lenses in
the optical axis direction; and said eye cup portion including a
cylindrical eye cup member that is rotatively disposed at an outer
side of said diopter ring and is guided by said cam pin in the
optical axis direction by rotating of the cylindrical eye cup
member around the optical axis to move said eye cup portion in the
optical direction.
7. An optical device according to claim 6, wherein said at least
one of said pair of right and left eyepiece portions is further
provided with a zooming portion that moves at least one of said
plurality of eyepiece lenses in the optical axis direction for
zooming.
8. An optical device according to claim 6, wherein a second
cylindrical member is fixedly disposed, between said diopter ring
and said cylindrical eye cup member, relative to said eyepiece
frame, said diopter ring rotates while sliding along the inner
surface of said second cylindrical member, and said cylindrical eye
cup member rotates while sliding along the outer surface of said
second cylindrical member.
9. An optical device according to claim 6, wherein said diopter
ring has a spiral slot that engages with said cam pin to be guided
in the optical axis direction, and said cylindrical eye cup member
has a spiral slot that engages with said cam pin to be guided in
the optical axis direction.
10. An optical device according to claim 6, wherein said eye cup
portion includes an elastic member that covers said cylindrical eye
cup member.
Description
INCORPORATION BY REFERENCE
[0001] The disclosure of the following priority application is
herein incorporated by reference:
[0002] Japanese Patent Application No. 2000-003799, filed Jan. 12,
2000.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The present invention relates to an optical device, such as
binoculars, provided with an eye cup on the eyepiece portion.
[0005] 2. Description of the Related Art
[0006] Conventionally, on the periphery of the eyepiece portion of
binoculars is attached a cylindrical eye cup protruding from the
eyepiece lenses toward an observer. The eye cup maintains a certain
distance between the eyepiece lenses and the observer's eye by the
eye cup being applied to the face around the observer's eye. The
observer's eye is thus positioned approximately at the pupil
position of the optical system in the binoculars, and the observer
can obtain a large field of view and stable observation. For an
observer wearing glasses, the eye cup contacts to the surface of
the glasses, and the distance between the eyepiece lenses and the
observer's eye becomes too large to secure proper observation. To
remove this drawback, the eye cup is conventionally so constructed
that it can be drawn by its rotation or can be turned over.
[0007] Additionally, each of the two eyepiece portions of the
binoculars has a mechanism for independently moving its eyepiece
lenses a certain amount in the optical axis direction for diopter
adjustment.
[0008] Referring to FIG. 3, an eyepiece portion of binoculars
provided with a via-rotation-drawable type eye cup will be
specifically described. In the configuration of FIG. 3, eyepiece
frame 22 is fixed on lens barrel body 21 of the binoculars. On the
inner surface of eyepiece frame 22 is slidably disposed cylindrical
eyepiece lens barrel 301. Inside of eyepiece lens barrel 301 are
fixed intermediate lens 12 and outer lens 13 that constitute
eyepiece lenses. On the outer surface of eyepiece lens barrel 301
is fixed cam pin 23. Linear slot 302 of which major axis is
parallel to optical axis 10 is formed in eyepiece frame 22 at the
position of cam pin 23. Cam pin 23 is engaged with eyepiece frame
22 by being inserted through linear slot 302. On the other hand, at
the outer side of eyepiece frame 22 is disposed diopter ring 20.
The inner surface of diopter ring 20 is slidably contacted with the
outer surface of eyepiece frame 22. Also, spiral slot 20a spirally
formed around optical axis 10 is formed in diopter ring 20, and the
head of cam pin 23 is inserted in spiral slot 20a. Cam pin 23 is
thus engaged also with diopter ring 20. It is to be noted that
diopter ring 20 is fixed relative to eyepiece frame 22 with respect
to the direction of optical axis 10 by positioning member 303.
Accordingly, diopter ring 20 rotates around optical axis 10 but is
fixed with respect to the direction of optical axis 10.
[0009] In such a configuration as FIG. 3, because cam pin 23 is
engaged with both of spiral slot 20a of diopter ring 20 and linear
slot 302 of eyepiece frame 22, cam pin 23 is moved in the direction
of optical axis 10 within the range of linear slot 302 by being
guided by spiral slot 20a when an observer rotates knurled portion
20b of diopter ring 20 around optical axis 10. Eyepiece lens barrel
301 on which cam pin 23 is fixed thus moves in the direction of
optical axis 10, and diopter adjustment can be performed.
[0010] Further, in the configuration of the eyepiece portion of
FIG. 3, an eye cup is constructed as follows. Specifically, at the
outer side of diopter ring 20 is disposed cylindrical eyepiece
sleeve 24. Eyepiece sleeve 24 is fixed on eyepiece frame 22.
Accordingly, eyepiece sleeve 24 does not rotates even when diopter
ring 20 rotates. On the outer side of this fixed eyepiece sleeve 24
is disposed eyepiece cam barrel 25. The inner surface of eyepiece
cam barrel 25 is slidably contacted with the outer surface of
eyepiece sleeve 24. Into eyepiece sleeve 24 is fixed eye cup
drawing cam pin 304 so deep as to reach eyepiece frame 22. Spiral
slot 25a spirally formed around optical axis 10 is formed in
eyepiece cam barrel 25; the head of cam pin 304 is inserted in
spiral slot 25a; and cam pin 304 is engaged with spiral slot 25a.
Further the outer surface of eyepiece cam barrel 25 is covered with
eyepiece rubber 26 to effect soft contact with the observer.
[0011] Thus, when the observer rotates eyepiece cam barrel 25
around optical axis 10, eyepiece cam barrel 25 covered with
eyepiece rubber 26 integrally moves in the direction of optical
axis 10 by spiral slot 25a being guided by the fixed cam pin 304.
In this manner, the eye cup can be drawn and returned to the
original position.
[0012] Next, referring to FIG. 2, an eyepiece portion of binoculars
provided with a turn-over type eye cup will be described. The
eyepiece portion of FIG. 2 has a multistage zooming function. Inner
lens lever 27 and intermediate lens lever 28 are respectively
moved, by a mechanism (not shown) to predetermined positions
corresponding to a zoom magnification selected by an observer via a
zoom lever (not shown) provided between the right and left lens
barrel bodies 21. These predetermined positions are so set that at
a higher magnification, the distance between inner lens 11 and
intermediate lens 12 becomes larger and that at a lower
magnification, the distance becomes shorter. Inner lens lever 27
supports claw 16a of inner lens outer frame 16. Inside of inner
lens outer frame 16 is disposed inner lens frame 14 in which inner
lens 11 is fixed. On the inner surface of inner lens outer frame 16
is provided a female screw; on the outer surface of inner lens
frame 14 is provided a male screw; and both screws are
screw-fitted. Thus, by inner lens frame 14 being rotated around
optical axis 10, inner lens frame 14 moves, in the direction of
optical axis 10, by an amount corresponding to its angle of
rotation. Further, intermediate lens lever 28 supports claw 17a of
intermediate lens outer frame 17. On the inner surface of
intermediate lens outer frame 17 is screw-fitted intermediate lens
frame 15 to which intermediate lens 12 is fixed. Thus, by
intermediate lens frame 15 being rotated around optical axis 10,
intermediate lens frame 15 moves, in the direction of optical axis
10, by an amount corresponding to its angle of rotation.
[0013] On the other hand, in the configuration of FIG. 2, eyepiece
frame 22 is fixed on lens barrel body 21. On the inner surface of
eyepiece frame 22 is screw-fitted outer lens frame 19 in which
outer lens 13 is fixed. Thus, by outer lens frame 19 being rotated
around optical axis 10, outer lens frame 19 moves, in the direction
of optical axis 10, by an amount corresponding to its angle of
rotation. Outer lens frame 19 is fixed, by screw 201, on diopter
ring 20 rotatively disposed at the outer side of eyepiece frame 22.
Thus, by diopter ring 20 being rotated, outer lens frame 19 rotates
and moves, in the direction of optical axis 10, by an amount
corresponding to its angle of rotation.
[0014] Furthermore, outer lens frame 19 has protruding portion 19a
elongated in the direction of optical axis 10, and this protruding
portion 19a is inserted into through hole 15b formed through
intermediate lens frame 15. Consequently, rotation of intermediate
lens frame 15 accompanies the rotation of outer lens frame 19.
Also, intermediate lens frame 15 is provided with protruding
portion 15a elongated in the direction of optical axis 10, and
protruding portion 15a is inserted into through hole 14b formed
through inner lens frame 14. Thus, rotation of inner lens frame 14
accompanies the simultaneous rotation of outer lens frame 19 and
intermediate lens frame 15. Intermediate lens frame 15 and inner
lens frame 14 move, via the rotation, by the same movement amount
in the direction of optical axis 10 as that of outer lens frame 19
caused by its rotation. Accordingly, because, via the rotation of
diopter ring 20, all of outer lens frame 19, intermediate lens
frame 15, and inner lens frame 14 move in the same direction and by
the same movement amount along optical axis 10, diopter adjustment
can be performed. It is to be noted that because intermediate lens
frame 15 and inner lens frame 14 move within the length of
protruding portion 19a and protruding portion 15a, respectively,
even when the zoom lever is operated, the engagement between
intermediate lens frame 15 and protruding portion 19a and that
engagement between inner lens frame 14 and protruding portion 15a
are maintained even when zoom magnification is changed.
[0015] In the configuration of FIG. 2, the eye cup is constituted
of eyepiece rubber 26 that covers diopter ring 20. During diopter
adjustment, eyepiece rubber 26 integrally rotates with diopter ring
20. For an observer wearing glasses to observe, eye cup portion 26a
of eyepiece rubber 26 is turned over to the side of diopter ring
20.
[0016] As described above, with respect to the eye cup, there have
been a via-rotation-drawable type and a turn-over type constituted
only of eyepiece rubber. The turn-over type eye cup, however,
deteriorates, due to longtime use, in its repeatedly turned over
portion of rubber, and cracks may occur in the portion. Besides,
the via-rotation-drawable type eye cup is, in recent years,
generally preferred from the viewpoint of design. However, although
in the case of the eyepiece portion of a fixed magnification
optical system without a zooming function as illustrated in FIG. 3,
the via-rotation-drawable type eye cup has been realized in the
past, such type eye cup has not yet been realized in the case of
the eyepiece portion with a zooming function as illustrated in FIG.
2. This is because the eyepiece portion provided with a zooming
function is complicated in structure, i.e., diopter ring 20 is
disposed so as to extend to the eyepiece side end surface of outer
lens frame 19, and the via-rotation-drawable eye cup configuration
including eyepiece sleeve 24, cam pin 304, and eyepiece cam barrel
25 as illustrated in FIG. 3 could not be applied as it is. Also,
any attempt, through some ingenuities, to attach a
via-rotation-drawable eye cup to the configuration of FIG. 2 would
result in a larger diameter than that of the eye cup from eyepiece
rubber 26 by the amount required by the conceived
via-rotation-drawable mechanism, and it is difficult to realize a
compact via-rotation-drawable eye cup.
SUMMARY OF THE INVENTION
[0017] It is an object of the present invention to provide
binoculars, while being provided with a zooming function in the
eyepiece portion, having a compact via-rotation-drawable type eye
cup.
[0018] In order to attain the above object, binoculars according to
the present invention comprises: a pair of lens barrel bodies; a
pair of eyepiece portions; at least one of the pair of eyepiece
portions being provided with an eyepiece frame fixed on one of the
lens barrel bodies, a plurality of eyepiece lenses, a diopter
adjusting portion that moves all of the plurality of eyepiece
lenses by the same movement amount in an optical axis direction,
and a via-rotation-drawable type eye cup portion; the diopter
adjusting portion including a cam pin fixed relative to the
eyepiece frame and a diopter ring that is guided by the cam pin in
the optical axis direction by rotating of the diopter ring around
an optical axis to move all of the plurality of eyepiece lenses in
the optical axis direction; and the eye cup portion including a
cylindrical eye cup member that is rotatively disposed at an outer
side of the diopter ring and is guided by the cam pin in the
optical axis direction by rotating of the cylindrical eye cup
member around the optical axis to move the eye cup portion in the
optical direction.
[0019] In this binoculars, it is preferred that the at least one of
the pair of right and left eyepiece portions is further provided
with a zooming portion that moves at least one of the plurality of
eyepiece lenses in the optical axis direction for zooming.
[0020] Also, it is preferred that a second cylindrical member is
fixedly disposed, between the diopter ring and the cylindrical eye
cup member, relative to the eyepiece frame, the diopter ring
rotates while sliding along the inner surface of the second
cylindrical member, and the cylindrical eye cup member rotates
while sliding along the outer surface of the second cylindrical
member.
[0021] Also, it is preferred that the diopter ring has a spiral
slot that engages with the cam pin to be guided in the optical axis
direction, and the cylindrical eye cup member has a spiral slot
that engages with the cam pin to be guided in the optical axis
direction.
[0022] Also, it is preferred that the eye cup portion includes an
elastic member that covers the cylindrical eye cup member.
[0023] An optical device according to the present invention
comprises: a pair of lens barrel bodies; a pair of eyepiece
portions; at least one of the pair of eyepiece portions being
provided with an eyepiece frame fixed on one of the lens barrel
bodies, a plurality of eyepiece lenses, a diopter adjusting portion
that moves all of the plurality of eyepiece lenses by the same
movement amount in an optical axis direction, and a
via-rotation-drawable type eye cup portion; the diopter adjusting
portion including a cam pin fixed relative to the eyepiece frame
and a diopter ring that is guided by the cam pin in the optical
axis direction by rotating of the diopter ring around an optical
axis to move all of the plurality of eyepiece lenses in the optical
axis direction; and the eye cup portion including a cylindrical eye
cup member that is rotatively disposed at an outer side of the
diopter ring and is guided by the cam pin in the optical axis
direction by rotating of the cylindrical eye cup member around the
optical axis to move the eye cup portion in the optical
direction.
[0024] In this optical device, it is preferred that the at least
one of the pair of right and left eyepiece portions is further
provided with a zooming portion that moves at least one of the
plurality of eyepiece lenses in the optical axis direction for
zooming.
[0025] Also, it is preferred that a second cylindrical member is
fixedly disposed, between the diopter ring and the cylindrical eye
cup member, relative to the eyepiece frame, the diopter ring
rotates while sliding along the inner surface of the second
cylindrical member, and the cylindrical eye cup member rotates
while sliding along the outer surface of the second cylindrical
member.
[0026] Also, it is preferred that the diopter ring has a spiral
slot that engages with the cam pin to be guided in the optical axis
direction, and the cylindrical eye cup member has a spiral slot
that engages with the cam pin to be guided in the optical axis
direction.
[0027] Also, it is preferred that the eye cup portion includes an
elastic member that covers the cylindrical eye cup member.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1 is a cross sectional view illustrating a
configuration of an eyepiece portion of binoculars according to an
embodiment of the present invention.
[0029] FIG. 2 is a cross sectional view illustrating a
configuration of an eyepiece portion, provided with a zooming
function, of conventional binoculars.
[0030] FIG. 3 is a cross sectional view illustrating a
configuration of an eyepiece portion, provided with a fixed
magnification optical system, of conventional binoculars.
[0031] FIG. 4 is a partly broken-away cross sectional view
illustrating an overall configuration of binoculars according to an
embodiment of the present invention.
[0032] FIG. 5 shows spiral slot 20a formed in diopter ring 20
viewed from upper side in FIG. 1.
[0033] FIG. 6 shows spiral slot 25a formed in eye piece cam barrel
25 viewed from upper side in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0034] Referring to the drawings, an embodiment of the present
invention will be described.
[0035] The overall configuration of the binoculars of the
embodiment of the present invention will be described referring to
FIG. 4, and the details of the eyepiece portion will be described
referring to FIG. 1. The binoculars of the embodiment have
objective portion 401 in which a pair of right and left objective
lenses are disposed, a pair of right and left lens barrel bodies 21
in each of which a prism, etc. are disposed, and a pair of eyepiece
portions 404 provided with a zooming function. As described later,
each of eyepiece portions 404 is provided with a
via-rotation-drawable type eye cup. Further, between the pair of
right and left lens barrel bodies 21 are disposed focusing knob (or
focusing ring) 402 for focus adjustment and zoom lever 403 for an
observer to select a desired zoom magnification among a plurality
of zoom magnifications.
[0036] Eyepiece portion 404 has, as eyepiece lenses, inner lens 11,
intermediate lens 12, and outer lens 13 that are successively
disposed on optical axis 10 as viewed from objective portion 401.
Eyepiece portion 404 includes inner lens lever 27 and intermediate
lens lever 28 for moving inner lens 11 and intermediate lens 12,
respectively, to predetermined positions corresponding to zoom
magnifications set at zoom lever 403. Inner lens lever 27 supports
claw 16a of inner lens outer frame 16. Inside of inner lens outer
frame 16 is disposed inner lens frame 14 in which inner lens 11 is
fixed. Further, intermediate lens lever 28 supports claw 17a of
intermediate lens outer frame 17. Inside of intermediate lens outer
frame 17 is disposed intermediate lens frame 15 in which
intermediate lens 12 is fixed. A mechanism, not shown, provided in
lens barrel bodies 21 moves inner lens lever 27 and intermediate
lens lever 28 to predetermined positions corresponding to zoom
magnifications set at zoom lever 403. Thus, inner lens 11 and
intermediate lens 12 respectively move to positions corresponding
to zoom magnifications set at zoom lever 403. The positions
corresponding to zoom magnifications are predetermined positions
that are so set that at a higher magnification, the distance
between inner lens 11 and intermediate lens 12 becomes larger and
that at a lower magnification, the distance becomes shorter for a
desired zoom magnification to be obtained.
[0037] Also, on the inner surface of inner lens outer frame 16 is
provided a female screw; on the outer surface of inner lens frame
14 is provided a male screw; and thus inner lens outer frame 16 and
inner lens frame 14 are screw-fitted. Accordingly, it is so
configured that when inner lens frame 14 rotates around optical
axis 10, inner lens frame 14 moves, in the direction of optical
axis 10, by an amount corresponding to its angle of rotation.
Similarly, intermediate lens outer frame 17 and intermediate lens
frame 15 are screw-fitted. Thus, it is so configured that when
intermediate lens frame 15 rotates around optical axis 10,
intermediate lens frame 15 moves, in the direction of optical axis
10, by an amount corresponding to its angle of rotation. The
pitches of the screws are so determined that the directions and the
movement amounts of both of inner lens frame 14 and intermediate
lens frame 15 corresponding to their angles of rotation become the
same. Thus, when inner lens frame 14 and intermediate lens frame 15
are rotated by the same angle of rotation, both of them move in the
same direction and by the same movement amount along optical axis
10. As described later, utilizing the movement, diopter adjustment
is performed.
[0038] On the other hand, on the eyepiece side end portion of lens
barrel body 21 is fixed eyepiece frame 22. On the outer surface of
eyepiece frame 22 are fixed two cam pins 23 being separated by an
angle of 180 degrees. On the outer side of eyepiece frame 22 is
slidably disposed diopter ring 20. Spiral slot 20a spirally formed
around optical axis 10 is formed in diopter ring 20, and by the
head of cam pin 23 being inserted through spiral slot 20a, cam pin
23 and diopter ring 20 are engaged. FIG. 5 shows spiral slot 20a
formed in diopter ring 20 viewed from upper side in FIG. 1. Diopter
ring 20 is screw-fixed to outer lens frame 19 disposed inside of
eyepiece frame 22. To outer lens frame 19 is fixed outer lens 13
held by outer lens inner barrel 18. Thus, when an observer rotates
knurled portion 20b of diopter ring 20 around optical axis 10,
spiral slot 20a of diopter ring 20 being guided by cam pin 23 fixed
relative to eyepiece frame 22, diopter ring 20 moves, in the
direction of optical axis 10, by an amount corresponding to its
rotation while rotating. Following this, outer lens frame 19 fixed
to diopter ring 20 also moves in the direction of optical axis 10
while rotating. The pitch of spiral slot 20a of diopter ring 20 is
determined so that the movement amount of outer lens frame 19 in
the direction of optical axis 10 corresponding to its angle of
rotation becomes the same as the above-described movement amount of
inner lens frame 14 and intermediate lens frame 15 corresponding to
their angle of rotation.
[0039] On outer lens frame 19 is formed protruding portion 19a
elongated in the direction of optical axis 10 for rotating
intermediate lens frame 15 in synchronization with the rotation of
outer lens frame 19. This protruding portion 19a is inserted into
through hole 15b formed through intermediate lens frame 15.
Consequently, when outer lens frame 19 rotates, intermediate lens
frame 15, being drawn by protruding portion 19a, also synchronously
rotates. Also, on intermediate lens frame 15 is provided with
protruding portion 15a elongated in the direction of optical axis
10 for rotating inner lens frame 14 in synchronization with the
rotation of intermediate lens frame 15. Protruding portion 15a is
inserted into through hole 14b formed through inner lens frame 14.
Thus, when diopter ring 20 moves in the direction of optical axis
10 while rotating, outer lens frame 19, intermediate lens frame 15,
and inner lens frame 14 move in the direction of optical axis 10 by
the same movement amount while rotating by the same angle of
rotation. By this, via the rotation of diopter ring 20, diopter
adjustment can be performed.
[0040] It is to be noted that the sizes of protruding portions 19a
and 15a and the aperture sizes of through holes 15b and 14b are so
determined that the movements of intermediate lens frame 15 and
inner lens frame 14 in the direction of optical axis 10 via the
operation of zoom lever 403 are not prevented and that play does
not occur during the rotation for diopter adjustment. Also, the
lengths of protruding portions 19a and 15a are set to be equal to
or longer than the movement amounts of intermediate lens frame 15
and inner lens frame 14 via the operation of zoom lever 403.
Accordingly, the movements of intermediate lens frame 15 and inner
lens frame 14 in the direction of optical axis 10 via the operation
of zoom lever 403 are not prevented by protruding portions 19a and
15a, and the movement amount is within the lengths of protruding
portion 19a and protruding portion 15a. Thus, diopter adjustment
can be performed at any zoom magnification.
[0041] Next, the configuration of a via-rotation-drawable type eye
cup will be described. The eye cup portion includes cylindrical
eyepiece sleeve 24 disposed at the outer side of diopter ring 20,
eyepiece cam barrel 25 disposed at the still outer side of eyepiece
sleeve 24, and eyepiece rubber 26 covering the outer side of
eyepiece cam barrel 25. In eyepiece sleeve 24, at the positions of
cam pins 23, are formed through holes 24a of circular aperture
form, and cam pins 23 are inserted through these through holes 24a.
Further, eyepiece sleeve 24 has protruding portions 24b at the side
of lens barrel body 21, and these protruding portions 24b are
disposed through apertures 101 formed in knurled portion 20b of
diopter ring 20 and are fitted into hollow portions 102 of eyepiece
frame 22. The circumferential length of aperture 101 is set to be
equal to or longer than that of spiral slot 20a. Accordingly,
eyepiece sleeve 24 does not rotates even when diopter ring 20
rotates, and moreover, eyepiece sleeve 24 does not prevent the
rotation of diopter ring 20. It is to be noted that protruding
portions 24b and through holes 24a define the position of eyepiece
sleeve 24 relative to eyepiece frame 22.
[0042] Eyepiece cam barrel 25 has a spiral slot 25a spirally formed
around optical axis 10. FIG. 6 shows spiral slot 25a formed in eye
piece cam barrel 25 viewed from upper side in FIG. 1. Into this
spiral slot 25a is inserted the head of cam pin 23. By this, when
an observer rotates cam barrel 25, spiral slot 25a rotates while
being guided by cam pin 23. Accordingly, cam barrel 25 moves, in
the direction of optical axis 10, by an amount corresponding to the
angle of rotation. Thus, eyepiece cam barrel 25 covered with
eyepiece rubber 26 can be drawn forth and back, and the
via-rotation-drawable type eye cup can be realized.
[0043] Additionally, to provide, e.g., a click-mechanism, on a
portion of the outer surface of eyepiece sleeve 24 is provided a
resilient protruding portion (not shown), and on the inner surface
of eyepiece cam barrel 25 are provided two hollow portions. The
resilient protruding portion and the two hollow portions are
arranged in a positional relationship such that the resilient
protruding portion fits into one of the two hollow portions when
eyepiece cam barrel 25 is drawn forth to the outermost position and
when drawn back to the innermost position, respectively. By this,
the eye cup is so-called-click-stopped at the positions where the
eye cup is drawn forth to the outermost position and when drawn
back to the innermost position. Thus, the eye cup cannot be easily
moved from the states where it is drawn forth to the outermost
position and where drawn back to the innermost position because to
perform the drawing forth and back operation of the eye cup, it is
necessary to rotate eyepiece sleeve 24 applying force to overcome
the resilient force of the protruding portion. The eye cup can be
thus held in stabilized positions during observation.
[0044] Next, the operations of various portions of the binoculars
according to the embodiment of the invention, when used by an
observer, will be described. For an observer not wearing glasses,
by drawing forth eyepiece cam barrel 25 covered with eyepiece
rubber 26 via its rotation, the binoculars can be used in the state
where the eye cup is drawn forth as shown FIG. 1. While the
observer looking into the eyepiece lenses applying the eye cup, by
rotating knurled portion 20b of diopter ring 20 as necessary, the
eyepiece lenses are moved in the direction of optical axis 10, and
diopter adjustment can be performed. During this diopter adjustment
operation, because the rotative operation of diopter ring 20 is
independent of the rotative operation of eyepiece cam barrel 25,
the position of the eye cup does not change. When the observer
operates zoom lever 403 to change the zoom magnification, inner
lens 11 and intermediate lens 12 of the eyepiece lenses move. Even
during the zoom magnification change operation, the position of the
eye cup does not change, and diopter adjustment can be performed by
diopter ring 20. Further, for an observer wearing glasses, by
rotating eyepiece cam barrel 25, eyepiece cam barrel 25 covered
with eyepiece rubber 26 can be easily drawn back.
[0045] As has been described above, in the binoculars according to
the embodiment of the invention, it is so configured that the
movement of outer lens frame 19 in the direction of optical axis 10
for the diopter adjustment of eyepiece portion 404 is realized by
spiral slot 20a being guided by cam pin 23 and that this cam pin 23
is also utilized to guide spiral slot 25a for the drawing operation
of eyepiece cam barrel 25 of the eye cup. Through this
configuration, a via-rotation-drawable eye cup can be incorporated
in eyepiece portion 404 provided with a zooming function.
Furthermore, in this configuration, because the diameter of the
via-rotation-drawable eye cup is approximately equal to that of
knurled portion 20b of diopter ring 20, a compact eye cup, while
being via-rotation-drawable, can be realized as is the case with a
turn-over type eye cup.
[0046] Further, in the embodiment of the invention, between diopter
ring 20 and eyepiece cam barrel 25 is disposed eyepiece sleeve 24
so configured that eyepiece sleeve 24 itself does not rotate and,
at the same time, it does not prevent the rotations of diopter ring
20 and eyepiece cam barrel 25. By this, diopter ring 20 and
eyepiece cam barrel 25 can independently rotate without being
affected by each other's rotative operation. Thus, in eyepiece
portion 404 of the embodiment of the invention, the diopter
adjustment and the drawing operation of the eye cup can be
independently performed.
[0047] Also, there is an effect that in the case of the
via-rotation-drawable type eye cup, because eyepiece rubber 26 need
not to be turned over, eyepiece rubber 26 less deteriorates
compared with the eyepiece rubber of a turn-over type eye cup.
[0048] It is to be noted that although, in the above-described
embodiment, it is so configured that in diopter ring 20 is provided
spiral slot 20a, and by spiral slot 20a being guided by cam pin 23,
outer lens frame 19 moves in the direction of optical axis 10 while
rotating, it can alternatively be so configured that diopter ring
20 does not move in the direction of optical axis 10. For example,
it may be so configured that in place of spiral slot 20a, a slot is
circumferentially formed in diopter ring 20, and diopter ring 20
simply rotates around optical axis 10 and does not move in the
direction of optical axis 10. Further, outer lens frame 19 and
eyepiece frame 22 are mutually screw-fitted as illustrated in FIG.
2 of conventional art; a protruding portion like protruding portion
19a is provided on diopter ring 20; and, the protruding portion,
being engaged with outer lens frame 19, is rotated following the
rotation of diopter ring 20. Thus, it can be so configured that,
without the use of spiral slot 20a, outer lens frame 19 moves in
the direction of optical axis 10 following the rotation of diopter
ring 20.
[0049] Although, in the above-described embodiment, it is explained
as an example that each of mechanisms for diopter adjustment is
independently provided on each of the two eyepiece portions, one
mechanism for diopter adjustment may be provided on either one of
the two eyepiece portions.
[0050] Although, in the above-described embodiment, the
configuration in which a via-rotation-drawable type eye cup is
realized in an eyepiece portion of binoculars provided with a
zooming function, also with respect to an optical device, such as a
stereomicroscope, provided with a zooming function, by making the
configuration of its eyepiece portion as illustrated in FIG. 1, a
via-rotation-drawable type eye cup can be realized.
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