US 4,397,534 A · Device for displaying bulb photographing operation time in a photographic camera

Abstract

A display device for displaying the time of a bulb photographing operation is arranged so that a counter for counting the clock pulses starts to operate when the bulb photographing mode is set in the camera and the release operation of the camera is started. A decoder incorporated in the camera decodes the content of the counter and a display instrument displays the output of the decoder in such a manner that the photographer can visually recognize the bulb photographing operation time. Several embodiments of the circuitry for controlling the nature of the display, including timing charts therefor, are set forth.

Claims4

Dependent claims

A display device for a photographic camera, comprising:

(a) means for producing a release signal in response to a release operation of the camera;
(b) means for producing a bulb phtographing setting signal in response to setting of a bulb photographing mode of camera operation;
(c) a counter for counting a number of input pulses and providing a counter output;
(d) a decoder for decoding the output of the counter;
(e) display means for displaying the output of the counter;
and
(f) control means for enabling the display means to display the output of the counter the content of which varies successively, when both of the release signal and the bulb photographing setting signal are applied to input terminals of the control means.

4 more elements

Dependencies are inferred from the claim text.

Device for displaying bulb photographing operation time in a photographic camera

Life of this patent

Device for displaying bulb photographing operation time in a photographic camera

Life of this patent

Abstract

Claims4