The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 05, 1980
Filed:
Jul. 10, 1978
Kenji Kanemaru, Chiryu, JP;
Takashiroh Iwasaki, Tokyo, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
An automatic control circuit system for cameras provided with a focal-plane shutter having front and rear screens, in which a battery voltage is supplied into the automatic control circuit system via a semiconductor switching element when a first release switch of a two-step release switch of a two-step release switch is closed. When a second release switch is closed, the rear screen starts running. A potential for electrically turning on the semiconductor switching element when the first release switch is closed is applied to a control electrode of the switching element. The automatic control circuit system is provided with an electric signal holding circuit, which is triggered with an electric signal generated when the second release switch is closed, to hold at the output terminal of the control electrode an output signal whereby an electric signal for electrically turning on the semiconductor switching element is held in the control electrode and retain the supply of the battery voltage into the automatic control circuit system. The electric signal holding circuit is triggered in response to a rear screen control signal whereby the starting of running of the rear screen of the focal-plane shutter is instructed, to reverse the holding of the output signal so that the semiconductor switching element is electrically turned off with the supply of the battery voltage into the automatic control circuit system stopped.