To smoothly reproduce density gradation of an image without making a step height great enough to be visually recognized between adjacent levels occur in the density gradation of the image to be reproduced, in terms of an image forming apparatus and an image forming method, wherein the amount of light emitted from a light-emitting device such as an organic EL device is controlled by using the image input signal, so that an image can be exposed and recorded.
A first light-amount control signal V1 for controlling the amount of the light emitted by the organic EL device is generated from the image input signal. An ON/OFF control signal V2 for controlling an ON/OFF state of exposure by the organic EL device, and a second light-quantity control signal V3 for controlling the amount of the emitted light for the exposure are generated from the image input signal. A light-emission control signal of the organic EL device is generated by performing signal switching among the signals V1, V2 and V3, depending on the amount of differences of image formation density between a control level of the amount of the light to be emitted by the organic EL device in accordance with the image input signal, and a control level adjacent to the above control level.
HIUGA HIROAKI
Haruko Sanwa
Hiroshi Fukushima