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:
Jan. 17, 1995
Filed:
Apr. 06, 1993
Applicant:
Inventor:
Ralph E Lovelace, Los Gatos, CA (US);
Assignee:
Hewlett-Packard Company, Palo Alto, CA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01J / ;
U.S. Cl.
CPC ...
2502 / ; 330308 ;
Abstract
A photodetector circuit provides a highly accurate digital signal output in response to incoming optical pulses from an LED having an inherent optical output fall time. The LED is optically coupled to a photodiode which produces an input current in response to the optical output. The input current is amplified by an amplifier having two stages to produce an output voltage signal for switching an output transistor. An RC circuit is coupled between the first and second stage amplifiers for introducing a transient into the output voltage signal for reducing propagation delay and increasing the noise margin of the circuit.