Photography – With exposure objective focusing means – focusing aid – or... – Manually actuated power focus
Reexamination Certificate
2000-02-14
2002-09-24
Mathews, Alan A. (Department: 2851)
Photography
With exposure objective focusing means, focusing aid, or...
Manually actuated power focus
C396S137000, C396S133000
Reexamination Certificate
active
06456796
ABSTRACT:
BACKGROUND OF THE INVENTION
This application claims the priority of Japanese Patent Applications Nos. 11-54295,11-54296, 11-54297, filed on Mar. 2. 1999, No. 11-60993 filed on Mar. 9, 1999, which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to a manual and electric motor operated apparatus for lens barrels, and more particularly to an apparatus permitting both manual and electric operations without deliberate switching in driving the zooming and focusing functions of the lens unit.
2. Description of the Prior Art
According to the prior art, a lens barrel for use in photographic cameras or television cameras is provided with a focusing lens for focusing and/or a zoom lens for varying the rate of magnification, and permits switching between manual and electric (automatic) operation modes (e.g. Japanese Patent No. 2773230).
FIGS.
13
(A) and
13
(B) illustrate an example of configuration concerning zoom driving in a conventional lens barrel. In FIG.
13
(B), the left side of a barrel
1
in the drawing is its front side, and the barrel
1
is provided with a zooming ring
3
which is rotatable relative to a body ring
2
. This zooming ring
3
is configured to be movable a zoom lens in the direction of the optical axis by its internal mechanism. Also, on the circumference of this zooming ring
3
are formed external gear
4
, and to the body ring
2
are fitted a switching gear
6
and a shaft
6
A via a bearing member
5
, the shaft
6
A being separately formed from the switching gear
6
, which pivots on the shaft
6
A movably in the axial direction and rotatably.
The above mentioned switching gear
6
has, as illustrated, a first toothed wheel
6
B engaging with the shaft gear
8
of a zoom motor
7
, and a second tooth wheel
6
C moving forward to engage with the external gear
4
of the above mentioned zooming ring
3
. Furthermore, a switching knob
10
is provided to switch between manual and electric operating modes by a rotational action, and a drive pin
11
, fitted to the underside disk of this switching knob
10
, is arranged in a concave portion between the above mentioned first toothed wheel
6
B and second toothed wheel
6
C.
In the above mentioned configuration, when the switching knob
10
is turned into the position of FIG.
13
(A), the mechanism is set for manual operation, and the switching gear
6
moves backward to disengage from the external gear
4
of the zooming ring
3
. In this state, therefore, the zooming ring
3
can be manually turned, and this turning drives the,zoom lens to a desired rate of magnification.
On the other hand, as the switching knob
10
is turned clockwise from the state of FIG.
13
(A), the mechanism is switched to electric (automatic) operation. This switching knob
10
, by the turning of its drive pin
11
to the position of the chain line in the drawing, moves the switching gear
6
forward, and engages the second toothed wheel
6
C with the above mentioned external gear
4
. At this time, the other first toothed wheel
6
B does not disengage from the shaft gear
8
of the zoom motor
7
. Therefore, when in electric operation, pressing a zooming switch (not shown) turns the zoom motor
7
, and this in turn causes the zooming ring
3
to be rotated via the switching gear
6
, with the result that the zoom lens is enabled to be driven in a prescribed direction.
However, the above mentioned lens barrel, which can be switched between manual and automatic operation modes, requires a manual switching action to turn the switching knob
10
as stated above, and this action is troublesome. Moreover, this switching action may prevent, for instance, quick focusing on the object to deprive the photographer of a good shooting opportunity.
Also, since the optimal level of heaviness (operation torque) of manipulating the zooming ring
3
as described above may vary with the manual power or preference of the photographer, making it variable as desired would improve the handling case of the camera.
There is the further problem that the level of heaviness (operation torque) of manipulating the zooming ring
3
may vary with the type of the lens and/or other conditions. Thus in such an apparatus, which allows replacement of one type of lens barrel with another, or where various lens barrels are to be fabricated with different lenses built into them, lens barrels even of the same type may vary from one another in fine details, and if they do, the lens driving torque will vary from barrel to barrel. Moreover, the torque may subtly vary with a number of conditions including the ambient temperature and how grease is applied. Such fluctuations in driving torque would pose little problem in electric operation, but in manual operation they would be sensed as differences in actual operation torque.
Furthermore, in an apparatus having a conventional zooming function, a so-called pumping phenomenon, i.e. a change in the angle of field, theretofore occurs when the focusing lens is moved. Thus, in this phenomenon which is more conspicuous at the wide angle end, focusing may invite, for instance, narrowing of the angle of field, therefore resulting in a slightly expanded image.
BRIEF SUMMARY OF THE INVENTION
Object of the Invention
The present invention has been attempted in view of the problems noted above, and its first object is to provide a manual and electric motor operated apparatus for lens barrels which can dispense with deliberate switching between manual and automatic modes and allow quick adjustment of conditions regarding a given object.
A second object is to enable the torque of manual operation to be freely set for the apparatus which requires no deliberate switching between and manual and automatic modes, and a third object is to prevent the operating torque from being varied by the type of lens and/or other conditions.
A fourth object is to enable the apparatus which requires no deliberate switching between and manual and automatic modes to correct any pumping phenomenon that may arise during a focusing action.
SUMMARY OF THE INVENTION
In order to attain the above mentioned first object, a manual and electric motor operated apparatus for lens barrels comprising: a lens barrel for holding lenses movably; an electric motor for automatically moving the lenses; a lens operating ring (manually operating ring), arranged rotatably on the circumference of these lenses for manually moving the lenses, having external gear formed thereon to engage with a transmission gear for transmitting the revolutions of the electric motor; a clutch mechanism for connecting and disconnecting the external gear of this lens operating ring and the electric motor to and from one another; and a clutch operating motor for connecting and disconnecting this clutch mechanism.
The clutch mechanism may have a gear moving plate (clutch disk) which is moved by the above mentioned clutch operating motor in the axial direction and has a gearing function and a gear fixing plate (clutch disk) which is connected to the gear moving plate and has a gearing function, wherein one of these gears is connected to the electric motor side and the other is connected to the external gear of the lens operating ring; and a revolving-while-declutched mechanism for enabling the gear (clutch disk) connected to the external gear of the lens operating ring to rotate when the clutch mechanism is disconnected.
Further, it is preferable to execute an action to connect the clutch mechanism when an operation control signal is supplied from an electric operation switch And to execute an action to disconnect the clutch mechanism when the operation control signal is no longer supplied.
The above mentioned configuration, in which the clutch mechanism is disconnected during manually operation, can drive the zoom lens and the focusing lens by turning the lens operating ring. In that state, the gear moving (or fixing) plate connected to the external gear of the lens operating ring is allowed by the revolving-while-declutched mechanism to turn freely, and accordingly
Kaneko Keiji
Tanaka Minoru
Tateno Hidetomo
Fuji Photo Optical Co., Ltd.
Mathews Alan A.
Smith Arthur A
Snider Ronald R.
Snider & Associates
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