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:
May. 08, 1984
Filed:
Dec. 31, 1981
Frank F Fang, Yorktown Heights, NY (US);
James C McGroddy, Briarcliff Manor, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A digital photodetector circuit having a photosensing stage connected to a depletion mode field effect transistor forming an inverter stage, increased sensitivity is achieved by then coupling the output of the photo inverter to a second photo inverter whose photosensitive element serves as the active load of an enhancement mode field effect transistor in the inverter stage. The circuit is readily fabricated in integrated structures. The circuit performance may be adjusted for responsiveness to light sensitivity and to provide selectable electrical output signal level and impedance matching including bistable performance.