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:
Feb. 15, 1977
Filed:
Mar. 15, 1976
Peter Klaus Runge, Fair Haven, NJ (US);
Bell Telephone Laboratories, Incorporated, Murray Hill, NJ (US);
Abstract
An optical ternary pulse transmission system is disclosed in which a light emitting diode is caused to generate either one of two light intensity outputs in response to the voltage pulses presented at either one of two input terminals. The voltage pulse at each input terminal is coupled to the light emitting diode through a gain control network. Most of the light from the light emitting diode is coupled to an optical fiber, and a first photodetector is positioned close to the light emitting diode in order to capture stray light not coupled into the optical fiber. A second photodetector with an opaque coating is positioned such that its position and the position of the first photodetector are electrically symmetrical with respect to the light emitting diode. The electrical signal from the second photodetector representing parasitic coupling is subtracted from the signal developed by the first photodetector in order to develop a signal dependent only on light intensity variations. First and second comparator circuits are selectively gated by the input voltage pulses to utilize selected pulses of the light dependent signal in developing feedback voltages for the gain control networks.