| 摘要 |
<p>PURPOSE:To detect overload of a paper feed motor and to prevent burning of the paper feed motor by stopping the paper feed motor if the paper feed roller does not return to home position upon elapse of a specific time after start of rotation. CONSTITUTION:A timer 30 is constituted with resistors 31, 32, 33 and a comparator 35, and when a power source is turned ON and when the collector voltage of a transistor 36 goes from low level to high level, charging of a capacitor 34 is started so as to start a timer 30. If the optical path of a roller position sensor 19 is not blocked by a barrier board fixed to the gear of a paper feed roller even upon elapse of a specific time after start of rotation of the paper feed roller, a transistor 37 is turned ON so as to stop the motor 2. Consequently, overload of the paper feed motor 2 can be detected accurately through a timer 30 and the paper feed motor 2 can be protected from burning.</p> |
