| 摘要 |
PURPOSE:To monitor accurately toner consumption conditions by using fundamental clocks of a prescribed cycle to integrate the black level period of a picture signal. CONSTITUTION:Main scanning by a VDO signal 302 is repeated plural times to obtain an image in the main scanning direction, and the toner is consumed in parts where the VDO signal 302 is in the high level. The VDO signal 302, a fundamental clock 303, an HENV signal 406, and a VENV signal 407 are inputted to an AND gate circuit 401, and an integral clock 304 as the output of the circuit 401 is inputted to an electric counter 402. A cycle T of the funda mental clock 303 is selected to satisfy relations T=KX1/v (K is a constant and (v) is the scanning speed). Each time the electric counter 402 reaches a prescribed counted value, the counter 402 supplied a pulse motor driving pulse 408 to a pulse motor driving circuit 403, and a mechanical counter 405 is counted up by one step with a pulse motor 404. |
