Abstract: A color image formation system in which transfer means for sequentially receiving plural color images is idled if raster image data for a color has not yet been converted from a page description language into the raster image. A page description language or other code data for a first color is converted into a raster image of the first color and an electrophotographic process is commenced whereby a laser beam is modulated in accordance with the raster image of the first color and the image formed by the modulated laser beam is transferred to rotatable transfer means. After image formation in the first color is complete, code data for the second color is converted into raster image data. If conversion of the second color is not yet complete but the transfer means has rotated to a position where it is ready to receive the second color, the transfer means is idled by continued rotation thereof and forcibly restricting laser beam illumination whereby the transfer means is fed blank to a predetermined position.

Abstract: In an image printing operation, advance sheet feeding is performed if the size of a recording medium is known upon feeding at least one sheet of the recording medium. To the contrary, advance sheet feeding is not performed if the size of a recording medium is not known, for example, immediately after a power supply has been turned on or after a new supply of recording medium has been placed in a sheet feeding unit.

Abstract: The present invention has an object to provide an image forming apparatus and method which enables an operator to easily adjust to the desired printing density. A paper feeding roller is driven in timing along with a registration roller. The irradiation of a modulated laser beam is started, a developing high-voltage is changed from "0" V to a predetermined voltage V1, and the voltage is changed to V2 at other timings. By sequentially changing the voltage in this manner, the printing densities from laser modulating data d1 to d10 are adjusted and printing in different densities can be performed.

Abstract: The present invention has an object to provide an image forming apparatus and method which enables an operator to easily adjust to the desired printing density. A paper feeding roller is driven in timing along with a registration roller. The irradiation of a modulated laser beam is started, a developing high-voltage is changed from "0" V to a predetermined voltage V1, and the voltage is changed to V2 at other timings. By sequentially changing the voltage in this manner, the printing densities from laser modulating data d1 to d10 are adjusted and printing in different densities can be performed.

Abstract: An image signal processing device is arranged to convert an analog image signal into a digital image signal after the analog image signal is clamped, to separate, in the form of a digital signal, a synchronizing signal from the digital image signal and to control a clamping action on the analog image signal according to a state of the separated digital synchronizing signal. The arrangement enables the device to always stably perform the clamping action.