Camera

Details Camera Camera

1999-09-10

2001-01-30

Perkey, W. B. (Department: 2851)

Photography

With film drive

Having significant electronic circuit detail

C318S603000

Reexamination Certificate

active

06181882

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a technique of winding, for example, photographic film by a predetermined amount that corresponds to, for example, one frame and then stopping it, and in particular to a technique of controlling the stop position of photographic film accurately. The present invention relates to an apparatus having a drive control device that can control the stopping of a moving member accurately.
2. Description of the Prior Art
In photographing with a camera, to make efficient use of photographic film, it is desirable that the film be transported with a minimum interval left between two consecutive already-exposed frames. To achieve this, it is essential to control the stopping of a motor accurately enough to allow the film, which is wound by the motor, to stop exactly in a desired position. Conventionally, the stopping of film winding is controlled by stopping the motor by applying braking or a reverse current thereto a predetermined period of time (or distance) before the position in which the film is expected to stop. This permits the motor to stop relatively quickly.
However, the amount of rotation that a motor makes while its rotation speed drops from a particular level to zero varies from motor to motor according to the inertia and other characteristics thereof, and therefore, if the time at which braking or a reverse current starts being applied is determined uniformly, the film may stop in varying positions from camera to camera, causing each camera to use a different proportion of the film per exposure. This leads to a serious problem in particular in arrangements where such a difference is accumulated every time the film is wound. In the first place, it is difficult in general to stop a motor exactly in a desired position with a simple structure, and this is true not only with cases where the stopping of film winding is controlled but also with any case where the driving of a motor is controlled in some way.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a camera having a function of stopping a motor exactly and quickly in a desired position with a simple structure.
To achieve the above object, according to one aspect of the present invention, a camera is provided with: a motor; a camera mechanism driven by rotation of the motor; a detector for detecting the rotation direction of the motor; and a controller for driving the camera mechanism by energizing the motor in such a way that the motor rotates in a forward direction. In this camera, to stop the motor, the controller energizes the motor in such a way that the motor rotates in a reverse direction and then, in response to a rotation direction inversion detecting output fed from the detector, energizes the motor in such a way that the motor rotates in the forward direction again for a predetermined period of time.


REFERENCES:
patent: 4404508 (1983-09-01), Nishida et al.
patent: 4576457 (1986-03-01), Fukuda et al.
patent: 6104880 (2000-08-01), Kamishita et al.
patent: 5-34782 (1993-02-01), None
patent: 6-124124 (1994-05-01), None

Affiliated with

Also associated with

Rating

Camera 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, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Camera will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2535076