Touch panel device

Abstract

A touch panel device includes an abnormal state determining part that determines if there is an abnormal state based on second difference information extracted by a second difference information extracting part and a second baseline stored in a second baseline storage, and a controller that, if the abnormal state determining part determines that there is an abnormal state, controls to update a first baseline stored in a first baseline storage and the second baseline stored in the second baseline storage.

What is claimed is: 
     
         1 . A touch panel device, comprising:
 a touch panel having a plurality of sensors that measure a capacitance;   a first difference information extracting part that extracts, as first difference information, a difference in capacitance between adjacent ones of said plurality of sensors;   a first baseline storage that stores, as a first base line, said first difference information extracted by said first difference information extracting part when a detection target is not in proximity to or does not contact said touch panel;   a detecting part that detects proximity to or contact with said touch panel by said detection target based on said first difference information extracted by said first difference information extracting part and said first baseline stored in said first baseline storage;   a second difference information extracting part that extracts, as second difference information, a difference in capacitance between a reference sensor being a predetermined sensor among said plurality of sensors and a sensor among said plurality of sensors and different from said reference sensor;   a second baseline storage that stores, as a second baseline, said second difference information extracted by said second difference information extracting part when said detection target is not in proximity to or does not contact said touch panel;   an abnormal state determining part that determines if there is an abnormal state based on said second difference information extracted by said second difference information extracting part and said second baseline stored in said second baseline storage; and   a controller that, if said abnormal state determining part determines that there is an abnormal state, controls to update said first and second baselines stored in said first and second baseline storages respectively.   
     
     
         2 . The touch panel device according to  claim 1 , wherein
 said plurality of sensors include a sensor arranged outside a detection region where a sensor to be used by said detecting part is arranged, and   said second difference information extracting part uses said sensor arranged outside said detection region as said reference sensor.   
     
     
         3 . The touch panel device according to  claim 1 , further comprising a reference sensor contact determining part that determines if said detection target contacts said reference sensor,
 wherein, if said sensor contact determining part determines that said detection target does not contact said reference sensor, said abnormal state determining part determines if there is an abnormal state.   
     
     
         4 . The touch panel device according to  claim 3 , wherein
 a sensor among said plurality of sensors and including at least a sensor adjacent to said reference sensor is defined as a calibrating sensor, and   based on a difference in capacitance between said calibrating sensor and said reference sensor, said reference sensor contact determining part determines if said detection target contacts said reference sensor.   
     
     
         5 . The touch panel device according to  claim 3 , wherein if a difference between said second difference information extracted by said second difference information extracting part and said second baseline stored in said second baseline storage falls within a certain range, and if the number of such differences is the same as or larger than a predetermined number of sensors, said reference sensor contact determining part determines that said detection target contacts said reference sensor. 
     
     
         6 . The touch panel device according to  claim 1 , wherein
 said reference sensor used for extraction of said second difference information by said second difference information extracting part is different between a group of sensors among said plurality of sensors and arranged in a horizontal direction of said touch panel, and a group of sensors among said plurality of sensors and arranged in a vertical direction of said touch panel, and   said abnormal state determining part determines if there is an abnormal state about each of said groups of sensors.   
     
     
         7 . The touch panel device according to  claim 1 , wherein
 said controller determines if said touch panel device is in a normal operating state, and   if said controller determines that said touch panel device is in said normal operating state, said abnormal state determining part does not determines if there is an abnormal state.   
     
     
         8 . The touch panel device according to  claim 1 , wherein said second difference information extracting part selects, as candidate sensors for said reference sensor, at least two or more sensors from said plurality of sensors, obtains a difference in capacitance between each of these candidate sensors and a sensor among said plurality of sensors and different from this candidate sensor, and based on the resultant differences, determines which of said candidate sensors is to become said reference sensor.