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.

Date of Patent:
Feb. 01, 1977

Filed:

May. 27, 1975
Applicant:
Inventors:

Akio Yamanishi, Tondabayashi, JA;

Mashio Kitaura, Osaka, JA;

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G03B / ; G01J / ;
U.S. Cl.
CPC ...
354 53 ; 250205 ; 354 / ; 354 / ;
Abstract

An automatically light adjusted luminous indicator observable through a camera view finder includes a photoconductor exposed to the camera incident light and either constitutes or controls the resistance component of a frequency controlling RC network of a relaxation oscillator. The output of the relaxation oscillator controls a bi-stable multivibrator whose output is coupled through a switching transistor to the primary of a transformer whose secondary is connected to a light emitting member such as an electroluminescent device or a light emitting diode. The parameters of the network are adjusted so that the luminosity of the indicator and viewed image are about equal or within any desired ratio range. The photoconductor may also control an exposure control network.


Find Patent Forward Citations

Yamanishi, Akio. (1977). Luminance controlled indicator in camera view finder (U.S. Patent No. 4006485). U.S. Patent and Trademark Office. https://idiyas.com/patent/badge/4006485

Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile

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