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:
Apr. 29, 1980
Filed:
Apr. 24, 1978
Hideto Iwama, Kawasaki, JP;
Masamichi Toyama, Machida, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
In the disclosed automatic exposure control device for a motion picture camera and so on, a diaphragm driving arrangement drives a diaphragm arrangement. An exposure control arrangement having a light sensing element for sensing scene light and producing an electrical output corresponding to the scene brightness, controls the diaphragm driving arrangement on the basis of the output of the light sensing element, the sensitivity information of the film to be used and so on, so that a proper exposure can be obtained. A diaphragm presetting arrangement electrically controls the diaphragm driving arrangement independently of the exposure control arrangement to set the diaphragm arrangement at an intermediate opening position. A selector normally disables the control of the diaphragm driving arrangement by means of the exposure control arrangement and enables the control of the diaphragm driving arrangement by arrangement of the diaphragm presetting means. However, in response to the operation of the camera release, enables control of the diaphragm driving arrangement by the diaphragm presetting arrangement, and enables the control of the diaphragm driving arrangement by means of the exposure control arrangement. In consequence, before the camera as been released the diaphragm arrangement is always preset at the intermediate open position by means of the diaphragm presetting arrangement. Hence even when the brightness of the object to be photographed is very low, the response delay of the light sensing element is improved in and at the time of camera release and the diaphragm arrangement is quickly adjusted to a position for producing giving a proper exposure with the exposure control means.