| 摘要 |
PURPOSE:To control image density automatically and to prevent the density from being overcorrected by comparing reflection factor data on a photosensitive body that a sensor inputs with correction reference data, correcting the sensor voltage and generating an alarm when a correction limit is reached. CONSTITUTION:The sensor 17 inputs reflection factor data on a no-image formation area on a photosensitive drum to an arithmetic part 23 through an output terminal 21. The arithmetic part 23 compares the input data with the sensor correction reference data and data for sensor correction corresponding to the comparison difference is converted by a converter 24 and sent to an LED 17a to correct the voltage of the sensor 17. Therefore, the voltage of the LED 17a is raised correspondingly by a decrease in reflection factor due to the contamination of the sensor 17. Further, when the correction data reaches limit data, an abnormality warning is generated and the machine is stopped. Consequently, variation in image density due to the sensor contamination is corrected automatically to prevent an element from being destroyed owing to overcorrection. |
