| 摘要 |
<p>PURPOSE:To detect the abnormality of a touch sensor in its early stage by providing a control means which decides that the touch sensor is abnormal when the sensor is continuously on exceeding a specific time and excludes the on signal from the sensor. CONSTITUTION:Plural light emitting element arrays 1a and 1b (or light receiving element arrays 1c and 1d) are provided on the right and upper (or left and lower) sides of the touch sensor 1. On signals [X-axial signal sequence (x) and Y-axial signal sequence (y)] from the element arrays 1a and 1b are supplied to a touch sensor abnormality detection parts 5a and a touch point detection part 7. The detection part 5 part consists of a switch-on detection part 5a and a watchdog timer function part 5b and the detection part 7 consists of an abnormal touch sensor signal excluding part 7a and a and a touch point detecting function part 7b. Consequently, when the sensor 1 turns on, the on time is clocked by the detection part 5a and when this on time exceeds the specific time, the function part 5b decides that the sensor is abnormal. Then the on signal from the sensor is excluded 7 and following processing operation 13 is carried out.</p> |
