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. 28, 1989
Filed:
May. 31, 1988
Miklos J Kollanyi, Albuquerque, NM (US);
Frankie P Buchanan, Albuquerque, NM (US);
GTE Communication Systems Corporation, Phoenix, AZ (US);
Abstract
A laser driver circuit is disclosed for operating an electrical current driven light emitting device or laser. The laser driver circuit is driven from external equipment by a modulated electrical signal and includes a laser biasing network arranged to provide a threshold current to the laser. The current is sufficient to bias the laser to an operating point just below the laser's turn on threshold. First and second transistors connected to the laser form a differential switching amplifier. The differential switching amplifier is disposed to switch drive current provided by a constant current source to the laser. The drive current is sufficient to drive the laser over the threshold set by the laser biasing network. On the application of the modulated electrical signal to the first transistor of the differential switching amplifier the drive current is switched from one side of the differential switching amplifier to the other effectively turning the laser on and off.