| 摘要 |
PURPOSE:To improve accuracy in correcting and controlling image forming conditions by varying previous image forming conditions so that an initial output value corresponding to a control pattern for image forming conditions is within a previously set range. CONSTITUTION:Since exposure quantity on the face of a drum 4 greatly changes even in a combination of a constant exposure quantity (a voltage of a lamp 35 is constant) and a white reference pattern 42, a reference value (initial reference data) has to be set by device. Namely, the quantity of reflected light is not constant, and accordingly a potential of the pattern part of the photosensitive drum 4 is not constant. Therefore, since a toner attaching amount (density of a toner image of the pattern) determined by (pattern part potential) (developing bias potential) comes to be not constant, a fresh toner image is formed in response to a pattern of constant density after a developing bias being one image forming condition is increased or decreased in response to an output from the sensor. When the previously set level is obtained by performing these procedures, setting ends. A block diagram indicating these procedures is shown at the right. |
