Abstract: A color image-forming apparatus including two drums, two scanners for forming latent images on the two drums, four developing devices for developing the latent images on the drums into toner images with four colors, an intermediate transfer belt successively passing the drums so that the toner images are successively transferred onto the belt, a transfer unit for transferring the toner image on the belt onto a recording medium, and a control unit controlling the two scanners to form patterns of first, second, third, and fourth colors and controlling timing at which the two scanners write on the drums such that the patterns approach one another.

Abstract: A color image-forming apparatus including two drums, two scanners for forming latent images on the two drums, four developing devices for developing the latent images on the drums into toner images with four colors, an intermediate transfer belt successively passing the drums so that the toner images are successively transferred onto the belt, a transfer unit for transferring the toner image on the belt onto a recording medium, and a control unit controlling the two scanners to form patterns of first, second, third, and fourth colors and controlling timing at which the two scanners write on the drums such that the patterns approach one another.

Abstract: An ink-jet printer includes a rotary drum 10, having a dielectric peripheral surface 11, for rotating at a constant speed, a sheet loader 90 for loading a sheet to the rotary drum 10, a sheet holding system for causing the sheet to be held on the peripheral surface 11 of the rotary drum 10, and a print head section 200 for printing an image on the sheet held on the peripheral surface 11 of the rotary drum 10 by jetting ink to the sheet while the rotary drum 10 makes a predetermined number of rotations. Particularly, the sheet holding system includes a charging section 20 and a supplementary charger section 26. The charging section 20 is charges the peripheral surface 11 of the rotary drum 10 on an upstream side of the loading point where the leading end of the sheet loaded by the sheet loader 90 contacts the peripheral surface 11 of the rotary drum 10. The supplementary charger section 26 charges the sheet to supplement the electrostatic attraction force attenuated during the rotation of the rotary drum 10.

Abstract: An image forming method and apparatus uses an image forming unit including an image carrier and a write unit that forms an image on the image carrier. A moving member moves to transfer, at a transfer position, the image formed on the image carrier and a driving unit rotates and drives the image carrier. A control circuit controls rotation driving of the driving unit on the basis of a rotation state of the image carrier obtained during a predetermined time interval centered on the same rotation position of a preceding rotation as that of a current rotation.

Abstract: An image forming apparatus includes an image forming unit including an image carrier and a write means for forming an image on the image carrier, a moving member which moves to transfer, at a transfer position, the image formed on the image carrier, a driving unit for rotating and driving the image carrier, a control circuit for controlling rotation driving of the driving unit on the basis of a rotation state of the image carrier in a predetermined interval centered on the same rotation position of a preceding rotation as that of a current rotation.

Abstract: An ink-jet printer includes a rotary drum 10, having a dielectric peripheral surface 11, for rotating at a constant speed, a sheet loader 90 for loading a sheet to the rotary drum 10, a sheet holding system for causing the sheet to be held on the peripheral surface 11 of the rotary drum 10, and a print head section 200 for printing an image on the sheet held on the peripheral surface 11 of the rotary drum 10 by jetting ink to the sheet while the rotary drum 10 makes a predetermined number of rotations. Particularly, the sheet holding system includes a charging section 20 and a supplementary charger section 26. The charging section 20 is charges the peripheral surface 11 of the rotary drum 10 on an upstream side of the loading point where the leading end of the sheet loaded by the sheet loader 90 contacts the peripheral surface 11 of the rotary drum 10. The supplementary charger section 26 charges the sheet to supplement the electrostatic attraction force attenuated during the rotation of the rotary drum 10.

Abstract: An ink-jet printer includes a rotary drum 10, having a dielectric peripheral surface 11, for rotating at a constant speed, a sheet loader 90 for loading a sheet to the rotary drum 10, a sheet holding system for causing the sheet to be held on the peripheral surface 11 of the rotary drum 10, and a print head section 200 for printing an image on the sheet held on the peripheral surface 11 of the rotary drum 10 by jetting ink to the sheet while the rotary drum 10 makes a predetermined number of rotations. Particularly, the sheet holding system includes a charging section 20 and a supplementary charger section 26. The charging section 20 charges the peripheral surface 11 of the rotary drum 10 on an upstream side of the loading point where the leading end of the sheet loaded by the sheet loader 90 contacts the peripheral surface 11 of the rotary drum 10. The supplementary charger section 26 charges the sheet to supplement the electrostatic attraction force attenuated during the rotation of the rotary drum 10.

Abstract: An ink-jet printer includes a rotary drum for rotating at a constant speed and holding a paper sheet on its peripheral surface, a print head having ink-jet nozzles aligned in the axial direction of the rotary drum to perform printing by spitting ink from these ink-jet nozzles on the paper sheet rotating together with the rotary drum, and a sheet feed-in mechanism for feeding a paper sheet from a cassette and a manual feed tray to the rotary drum. Particularly, the sheet feed-in mechanism has a loading roller unit for loading the paper sheet to the rotary drum, a pickup section for picking up a paper sheet from one of the cassette and the manual feed tray to strike the leading end of the paper sheet against the loading roller unit, and a control section for controlling the loading roller unit to feed, to the rotary drum, the paper sheet whose posture has been corrected upon strike by the pickup section.

Abstract: A printing medium discharge apparatus used for discharging a printing medium from a rotary drum in an ink jet printer for printing a desired image onto the printing medium by an ink jet while holding the printing medium on the rotary drum, includes a printing medium carry and discharge device and a printing medium press device. The printing medium carry and discharge device carries thereon the printing medium from the rotary drum, on the printing medium an image having been printed, to make a non-image formation surface of the printing medium including no image formation region contact the printing medium carry and discharge device, and discharges the printing medium carried thereon to be moved apart from the rotary drum.

Abstract: A driving device for driving an end-luminescent line head provided with an array of end-luminescent EL elements includes a power supply, a high-voltage unit having an input side connected to the output side of the power supply and capable of generating a positive voltage and a negative voltage, a driver for driving the end-luminescent line head, connected to the output side of the high-voltage unit, voltage detecting device for detecting the drop of the output voltage of the power supply, and discharge device having one side connected to the output side of the high-voltage unit and the other side connected to the ground. The discharge devices closed to discharge the high-voltage unit immediately after the power supply has been turned off, to protect the driver and the end-luminescent line head from destruction.

Abstract: A power supply control apparatus, in which a high voltage generated by a switching transistor is prevented from being deviated from a nominal value, includes an arithmetic operator for controlling a duty ratio of switching operation of the switching transistor in response to a feedback value. The arithmetic operator includes a comparator for comparing a reference value with a digitized monitor voltage corresponding to the high voltage, and an adder for adding a minimum unit to the feedback value when the digitized monitor voltage is smaller than the reference value and for subtracting the minimum unit to the feedback value when the digitized monitor voltage is larger than the reference value. The result of addition from the adder is used for controlling the duty ratio of switching operation of the switching transistor.

Abstract: A high-voltage power source control device comprises a pulse generating section for holding duration data and periodically generating a switching pulse of a duration corresponding to the duration data, a monitor circuit for generating a monitor voltage corresponding to an output voltage of a high voltage power source, an A/D converter for outputting monitor voltage data based on a monitor voltage from the monitor circuit, and a processing section for deriving as adjustment data a difference between the monitor voltage data from the A/D converter and the reference voltage data, adding the adjustment data to the duration data, and setting the result of addition into the pulse generating section as new duration data to change the duty ratio of the switching pulse, thereby maintaining the output voltage of the high voltage power source at or near the reference voltage. The processing section in the control device has a shift register for decreasing the adjustment data at a preset rate.

Abstract: A laser power control apparatus which comprises an exciting section for supplying a drive current to a laser oscillation device, a laser power controller for generating current designating data which is incremented and decremented in a binary order, first and second digital/analog converters respectively assigned to lower digits and higher digits of the current designating data, for performing digital-to-analog conversion on the lower-digit data and the higher-digit data, a current setting section for setting a level for the drive current in accordance with the sum of output voltages of the first and second digital/analog converters. In the apparatus, the current setting section has circuit constants which cause the ranges of the drive current for sequential two values of the higher-digit data to be overlapped with each other by a predetermined amount, and the laser power controller has a circuit for limiting the range of the lower-digit data to compensate the overlap of the drive current ranges.

Abstract: A high voltage power supply controller includes a plurality of high voltage transformers, and causes the high voltage transformers to generate high voltages upon switching operations of corresponding switching transistors, to there by apply the high voltages to loads.