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:
Nov. 04, 2003
Filed:
Jun. 13, 2002
Ravi K. Kummaraguntla, Jamestown, NC (US);
Zhiliang Julian Chen, Plano, TX (US);
John G. Harris, Gainesville, FL (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
A photodiode sensor ( ) has a photodiode ( ) with an associated capacitance ( ), which may be a parasitic capacitance of the photodiode ( ). A switch ( ) is provided for charging the capacitance ( ) to a predetermined reset voltage (V ), such that when light impinges upon the photodiode ( ), the voltage on the capacitance ( ) discharges in a time proportional to an intensity of the light. A circuit ( ) is also provided for measuring the time for the capacitance ( ) to discharge to a predetermined threshold value ( ), which may be a function of time. The voltage on the output ( ) of the comparator ( ) may be sampled, with the sampling period also being variable as a function of time. The image may be reconstructed from time data indicating the relative times that discharge voltage of the pixels in an array cross the reference voltage ( ).