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:
Jan. 29, 2013
Filed:
Jun. 14, 2010
Ke-horng Chen, Taipei County, TW;
Shih-wei Wang, Hualien, TW;
Chi-lin Chen, Taipei County, TW;
Chih-chung Chen, Taichung County, TW;
Chia-lin Liu, Taichung County, TW;
Huai-an LI, Taoyuan County, TW;
Chi-neng MO, Taoyuan County, TW;
Ke-Horng Chen, Taipei County, TW;
Shih-Wei Wang, Hualien, TW;
Chi-Lin Chen, Taipei County, TW;
Chih-Chung Chen, Taichung County, TW;
Chia-Lin Liu, Taichung County, TW;
Huai-An Li, Taoyuan County, TW;
Chi-Neng Mo, Taoyuan County, TW;
Chunghwa Picture Tubes, Ltd., Bade City, Taoyuan, TW;
Abstract
A capacitance sensing circuit for a touch panel includes an analog capacitance-detecting circuit, a PWM-to-digital circuit and a self-calibration circuit. The analog capacitance-detecting circuit detects the capacitance of the touch panel based on a charging current, and converts the detected capacitance into a PWM control signal. The PWM-to-digital circuit converts the PWM control signal into a sensing count value based on a clock signal. The self-calibration circuit adjusts the value of the charging current or the frequency of the clock signal according to the difference between the range of the sensing count value and a predetermined detecting range. The predetermined detecting range can thus be adjusted for matching the range of the sensing count value.