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:
Apr. 10, 2012
Filed:
Sep. 17, 2007
Christoph Herrmann, Aachen, DE;
Walter Ruetten, Linnich, DE;
Matthias Simon, Aachen, DE;
Bernd Menser, Neu-Moresnet, BE;
Christoph Herrmann, Aachen, DE;
Walter Ruetten, Linnich, DE;
Matthias Simon, Aachen, DE;
Bernd Menser, Neu-Moresnet, BE;
Koninklijke Philips Electronics N.V., Eindhoven, NL;
Abstract
The application describes an X-ray detector, which uses direct X-ray conversion (DiCo) combined with CMOS pixel circuits. DiCo materials have to be used with high voltage to achieve a high field strength. This makes the sensor prone to leakage currents, which falsify the measured charge result. Moreover, most direct conversion materials suffer from large residual signals that lead to temporal artifacts (ghost images) in an X-ray image sequence. A circuit is described, which senses the sensor's dark current including residual signals from previous exposures before the sensor is exposed (again) to X-ray, and freezes relevant circuit parameters at the end of the sensing phase in such way, that the dark current (leakage current and residual signal) can still be drained during exposure. Therefore, the charge pulses generated in the sensor due to X-ray exposure can be integrated without charges carried by the leakage current or residual signal, thus obtaining a more accurate estimate of the deposited X-ray energy.