| 摘要 |
PROBLEM TO BE SOLVED: To prevent the generation of ground surface staining images without the influence of an installation environment by correcting a selection density to a reference value in a main control section when copying operations are executed continuously for a prescribed number of pieces and recording this data into a non-volatile ROM. SOLUTION: A density set changing counter is set at +1 when the selection density is not d4 or d8 in the main control section 21. This density set changing counter is cleared in the case of d4 or d8. When the density set changing counter registers >=50, this selection density data is replaced with the reference value data d4 and the display is changed over to a d4 selection as well to clear the density set changing counter and the copying operation is executed. The incident light quantity to an original density sensor 10 changes with a change in the lamp reference voltage and, therefore, the compared value VTh of the sensor output is changed to the value obtd. by adding the changed number of stages ×0.1V VTh ←VTh +0.1(n-4)} thereto. The changed reference value data and the density set changing counter data are recorded on an EEPROM 20 at the end of the copying. |
