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:
Aug. 31, 1976
Filed:
Jun. 30, 1975
James L Broderick, San Jose, CA (US);
William R Fowler, Sunnyvale, CA (US);
National Semiconductor Corporation, Santa Clara, CA (US);
Abstract
In a common package, a light emitter, which is responsive to an input signal, produces an output optical signal which is coupled through an optically transmissive electrical insulator to a principal photodetector disposed in stray capacitive coupled relation to the light emitter for detecting the optical signal to produce an output signal in response thereto. A dummy photodetector, which has similar electrical characteristics to that of the principal photodetector except that it is rendered nonresponsive to the output optical signal is similarly coupled in stray capacitive relation to the light emitter to derive a dummy output signal. The dummy signal together with the principal output signal are fed to the differential input terminals of a differential amplifier which takes the difference of the two signals, thereby cancelling common mode signal components capacitively coupled to said photodetector and producing an amplified output signal.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile