PURPOSE: To obtain a record with high quality without being influenced by character styles by controlling the formation condition of an electrostatic latent image formed on an image carrier and the image forming process of a developing condition, etc., in response to the variety of recorded characters.
CONSTITUTION: The developing bias power source 13a of a bias voltage A and the developing bias power source 13b of a bias voltage B are prepared in a developing device and selected by switching a switch 12. When a definite character style like Ming style is preferable, the power source 13a of the developing bias A is selected and a DC component -400V is set. When reverse development is performed, a potential contrastive with the potential of a bright part is 300V and lines become thinner. When a character of thick lines like a Gothic type is preferable, a developing bias B13b is selected and impressed on a sleeve 2. A DC component -600V is set and the potential contrastive with the one of the bright part is 500V so that the thick lines are developed.
HASEGAWA HIROTO
TANIGAWA KOICHI
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