Photography – With exposure objective focusing means – focusing aid – or... – Mechanical mechanism for displacement of exposure objective
Reexamination Certificate
2002-04-10
2004-03-16
Adams, Russell (Department: 2851)
Photography
With exposure objective focusing means, focusing aid, or...
Mechanical mechanism for displacement of exposure objective
C396S130000
Reexamination Certificate
active
06707996
ABSTRACT:
BACKGROUND OF INVENTION
1. Field of the invention
The present invention relates to a focus retaining mechanism, and more particularly, to a focus retaining mechanism of a camera.
2. Description of the Prior Art
Please refer to FIG.
1
.
FIG. 1
is a top view of a lens driving device
10
of a camera according to the prior art. The lens driving device
10
is disclosed in U.S. Pat. No. 5,680,649 “LENS DRIVING DEVICE FOR AUTO-FOCUS CAMERA”. The lens driving device
10
comprises a base
12
having a cylindrical and vertical opening
16
, a focusing lens
14
rotatably fixed within the opening
16
, a driving ring
40
rotatably fixed on the periphery of the opening
16
of the base
12
, a shutter-driving ring
44
fixed on the base
12
by hooking the driving ring
40
, a retaining member
42
, a lens barrel
18
mounted on the base
12
by hooking the driving ring
40
and the retaining member
42
, a first bi-directional driving motor
20
and a second bi-directional driving motor
30
fixed on the base
12
, an elastic element
34
mounted on the base
12
, and an electromagnetic valve
22
disposed on the base
12
.
In addition, a cylindrical projection
46
disposed on the driving ring
40
engages with an engaging portion
19
of the lens barrel
18
. Thus, when the driving ring
40
is rotated, the lens barrel
18
and the focusing lens
14
are also rotated. The second bi-directional driving motor
30
is used to rotate the shutter-driving ring
44
for controlling a shutter. The first bi-directional driving motor
20
is used to drive the electromagnetic valve
22
for mounting the retaining member
42
in a predetermined position so as to rotate the focusing lens
14
to a corresponding position. Moreover, an idler gear
70
and a first ratchet
50
are used for the transmission between the retaining member
42
and the electromagnetic valve
22
.
As shown in
FIG. 1
, when the second bi-directional driving motor
30
rotates the a shutter-driving ring
44
toward a positive direction via a second ratchet
32
to control an opening position of the shutter, the shutter-driving ring
44
pushes the driving ring
40
to rotate the lens barrel
18
and focusing lens
14
. At the same time, the driving ring
40
also moves the retaining member
42
so that a plurality of gear portions
43
engages with a hold lever
60
one by one. The retaining member
42
rotates the first ratchet
50
by engaging the idler gear
70
.
When the second bi-directional driving motor
30
moves the shutter-driving ring
44
toward a positive direction to a predetermined position, which is an appropriate position for focusing, the first bi-directional driving motor
20
controls the electromagnetic valve
22
to stop rotating the first ratchet
50
. At this time, a pull-back action to the retaining member
42
, which is generated by the elastic element
34
, is stopped due to the stop action of the electromagnetic valve
22
. Thus, the lens barrel
18
and the shutter-driving ring
44
do not circumrotate so that the lens driving device
10
can focus and retain position. At this time, the shutter-driving ring
44
moves to a predetermined shutter position and opens the shutter, and the lens barrel
18
also drives the focusing lens
14
to rotate to a corresponding position.
The second bidirectional driving motor
30
continues to rotate in a positive direction and moves the shutter-driving ring
44
to an utmost position
45
. At the same time, the first bi-directional driving motor
20
drives the electromagnetic valve
22
to rotate the first ratchet
50
so that the first ratchet
50
and the retaining member
42
rotate to corresponding utmost positions. At this time, the second bi-directional driving motor
30
provides no power to the lens driving device
10
. That means after the second bi-directional driving motor
30
moves the shutter-driving ring
44
to utmost position
45
, only the first bidirectional driving motor
20
provides a small amount of power to move focus retaining mechanisms such as the first ratchet
50
, the retaining member
42
, the lens barrel
18
, the shutter-driving ring
44
, and the elastic element
34
back to an initial state. After the first bi-directional driving motor
20
drives the electromagnetic valve
22
and the first ratchet
50
to their utmost positions, the first ratchet
50
does not contact with the electromagnetic valve
22
, and a spring
62
disposed on the base
12
pulls the hold lever
60
back to the initial state. This is an action of closing the shutter. In addition, the elastic element
34
also pulls the retaining member
42
back to the initial state so that the shutter-driving ring
44
, lens barrel
18
, and the first ratchet
50
are also moved back to the initial states.
As described above, the prior lens driving device
10
has a complicated focus retaining mechanism, and an electromagnetic valve and a gear assembly are needed. Thus, the complexity and costs of components are increased. In addition, although the electromagnetic valve
22
acts effectively, the available space of the lens driving device
10
is decreased with the use of the electromagnetic valve
22
.
SUMMARY OF THE INVENTION
It is therefore a primary objective of the claimed invention to provide a focus retaining mechanism of a camera with a simple design to solve the above-mentioned problem.
The claimed invention provides a focus retaining mechanism of a camera. The camera comprises a base, a focusing lens, a retaining wheel, a pushing member, and a retaining hook. The base has a cylindrical and vertical opening in it. The focusing lens is rotationally fixed within the opening. The retaining wheel is rotationally fixed in the base. The horizontal sides of the retaining wheel include a ratchet side, a smooth side, a first end, and a second end positioned over the connecting portions of the ratchet side and the smooth side. The pushing member is horizontally and movably fixed in the base for moving the focusing lens and the retaining wheel. The retaining hook includes a horizontal arm and a vertical arm. The horizontal arm can move across the upper side of the retaining wheel, and the vertical arm can thus contact each of the horizontal sides of the retaining wheel.
It is an advantage of the claimed invention that a focus retaining mechanism of a camera with a simple design is used for simplifying the focus retaining mechanism. These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment, which is illustrated in the various figures and drawings.
REFERENCES:
patent: 4985724 (1991-01-01), Akimoto et al.
patent: 5680649 (1997-10-01), Akimoto et al.
Hsu Winston
Primax Electronics Ltd.
Smith Arthur A
LandOfFree
Camera with a focus retaining mechanism does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Camera with a focus retaining mechanism, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Camera with a focus retaining mechanism will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3221780