| 摘要 |
PROBLEM TO BE SOLVED: To cope with the change of optical sensitivity by variably setting light quantity radiated from a density sensor and an output voltage shift level being the photoelectric conversion result of the density sensor and correcting the sensitivity of the density sensor so that the sensitivity of the density sensor may be in tolerance. SOLUTION: The measurement of an image carrier is performed based on specified reference light quantity, and the measured output voltage is transmitted to a CPU 50 and compared by a data comparison means 4 concerning whether it is within an error range with respect to a reference voltage value. When the compared result is NG and the transmitted data is not within the prescribed output voltage range (output voltage range of the density sensor 113 and the input voltage range of the CPU 50), the output voltage is shifted by an output shift level means 12, which is repeated until the output voltage is within the prescribed output range. Then, the correction values of the previously set reference voltage value of the image carrier and the measured output voltage data are calculated and introduced, and an LED light quantity setting means 5 is set so that the emitted light quantity may be corrected. |
