| 摘要 |
PURPOSE:To avoid the soil of a touch panel switch by covering this switch with a soil preventing sheet over a CRT display and then replacing the dirty sheet with new one. CONSTITUTION:When an exchange command for a coil preventing sheet 3 is given, a step motor 9 is driven to take up a dirty sheet 3 by a take-up roller 4. At the same time, a new sheet 3 is supplied by length l enough to cover a CRT display 1. Then it is discriminated whether an optical sensor 6 detected the termination of the dirty sheet 3 or not. If the sensor 6 detects the end of the sheet 3, the dirty sheet 3 is replaced with a new sheet 3. In the same way, the motor 9 is driven also in case the transaction frequency exceeds N. Thus a new sheet 3 is supplied from the roller 5 by the length l in place of the dirty sheet 3. |
