| 摘要 |
<p>PURPOSE:To remove a defect of the decrease of the printing density by mounting a temperature sensor to an LED head, and changing a bias voltage of a bias developing device by an output of the sensor. CONSTITUTION:A bias voltage is impressed to a developing roll 16 of a developing device 6 through a bias voltage controlling circuit 14. Moreover, a correction signal of a temperature correcting circuit 13 is fed to the bias voltage controlling circuit 14. Therefore, a bias voltage is automatically changed in accordance with the correction signal. The bias voltage impressed to the developing roll 16 is set higher than a potential of an exposed part of a photoreceptor 1 and therefore, an electric field is generated from the developing roll 16 towards the photoreceptor 1. As the bias voltage is set higher, the intensity of the electric field is increased, making it easier for the toners to adhere to the photoreceptor 1. Accordingly, the printing density is increased.</p> |
