One LED head has 26 LED chips. Each chip contains 8mm light-emitting elements.

  • If a vertical line 8mm in width appears on the image parallel to the direction of paper feed, it may be caused by a broken LED chip.

LED Positioning

The LED head contacts the spacer on the drum in order to hold the correct distance (focal length) from the PCDU (it is adjustable using a slide-movement method).

  • The LED spacer contacts the drum, so the drum wears out gradually as it rotates. If a worn PCDU (out of lifetime) is used, its focus gradually becomes blurred.

Image Position Adjustment

You can adjust the printing position from each tray with [Registration] in the Menu. At this time, the machine adjusts the following:

  • Horizontal Scan: Adjusted by moving the whole image position.
  • Vertical Scan: Adjusted by changing the light-emission timing.

  • There is no mechanical adjustment, unlike LD writing.
  • Writing applies to the extent of the LED head in the horizontal direction. So, if you want to adjust the printing position outside the setting range in [Registration], adjust the paper position in the feed tray.

In paper position adjustment in the feed tray, you can adjust horizontal registration by loosening the screws on the bottom of the tray, and then moving the holder to right or left (up to 2mm).

  • When in the default (±0) position, the holder position is at the triangle marked area [A] in the picture below.

LED Light Volume Adjustment

An EEPROM on the LED head contains data which controls the light intensity of each element. There is no adjustment.

Adjustment at Replacement

Adjustment at LED head replacement is not needed due to the EEPROM on the LED board. This ROM contains light volume adjustment data.