DEVICE FOR CONTROLLING IMAGE

摘要

PURPOSE:To enable toner concn. to be adjusted without providing a standard target on an original platen or near it by rendering developing bias at the time of developing a prescribed region different from that to be given to the region except said region, and detecting development characteristics. CONSTITUTION:A detector 8 for detecting the density of the pattern for detection is provided at the circumference of a photosensitive drum 1 between a developing device 5 and a cleaning device 9. The detector 8 detects the density of the detection pattern and its background formed on a part of the drum 1 on the outside of a latent image area. The reflection density expressed by voltage of the detection pattern region P2 detected with the detector 8 is compared with the preset standard density expressed by voltage. When it is judged that the reflected density of the region P2 is lower than the standard value, the toner is replenished from a toner replenishing section 51 in the developing device 5 or toner replenishing rate is increased to raise toner concn. in the developer.