| 摘要 |
PURPOSE:To obtain copied and printed matter with always a good photoconductive plate by providing functions of counting the number of sheets of the copied and printed matter that can be obtained from the same photoconductive plate and exchanging the photoconductive plate when the preset number of sheets is attained. CONSTITUTION:If photographic fogs are produced in nonimage parts when, for example, 500 sheets of copies are taken in electrostatic printing using a printing master provided with toner images secured onto photosensitive paper, the number of sheets of copies is counted and the printing master of the degraded characteristics is removed after about 400 sheets. A printing master is again made, and the copies of the number of sheets above this are obtained. If a large quantity of sheets are taken in an ordinary electrophotographic copying mode, the chargeability, residual potential, etc. of the photosensitive paper will degrade after about 200 sheets. Therefore, the number of copies is counted and when about 150 sheets are attained, the photosensitive paper is exchanged. |
