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:
Jul. 18, 1995
Filed:
Apr. 30, 1993
Lowell Stewart, Poway, CA (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
An optical drop detect circuit for a thermal ink jet printer. The optical drop detect circuit includes an optical sensor for providing an electrical output indicative of a presence of an ink drop, a transconductance amplifier responsive to the output of said optical sensor, first and second cascaded bandpass amplifiers responsive to the transconductance amplifier, a first comparator circuit responsive to the output of the cascaded bandpass amplifiers for providing an output pursuant to optical sensing of a first minimum ink drop size, and a second comparator circuit responsive to the output of the cascaded bandpass amplifiers for providing an output pursuant to optical sensing of a second minimum ink drop size.