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:
Sep. 14, 1999
Filed:
Dec. 03, 1997
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
A salient integration mode active pixel sensor. The active pixel sensor includes an amplify/compare transistor which has a threshold voltage. The amplify/compare transistor couples an input of the amplify/compare transistor to an output of the amplify/compare transistor when the input of the amplify/compare transistor exceeds the threshold voltage. A photo-diode generates a signal voltage which has a voltage level dependent upon the intensity of light received by the photo-diode. The signal voltage is coupled to the input of the amplify/compare transistor. A reset element couples a reset line to the photo-diode and discharges the photo-diode when the reset line is active. A coupling capacitor for couples a select line to the input of the amplify/compare transistor. The select line causes the input to the amplify/compare transistor to exceed the threshold voltage and thereby couple the signal voltage to the output of the amplify/compare transistor. The amplify/compare transistor can be an N-type MOSFET and the reset transistor can be an N-type MOSFET. Further, a back gate of the amplify/compare transistor is generally connected to a circuit ground.