Multibeam scanner

A multibeam scanner for scanning an image area with a plurality of laser beams and forming a plurality of scanning lines in the image area along a predetermined scan direction, the multibeam scanner comprising:

• a beam emitting means for emitting a plurality of laser beams that reach the image area with respective time lags therebetween;
• a time lag determination means for determining at least one of the time lags by generating a first time period between a reference detection time and a first detection time and a second time period between the first detection time and a second detection time and thereafter subtracting the first time period from the second time period, wherein the reference detection time is a time when a laser beam emitted by one of the plurality of the beam emitting points is detected at a predetermined beam detection position during a first scanning cycle and the first detection time is a time when the laser beam emitted by the one of the plurality of the beam emitting is detected at the predetermined beam detection position during a second scanning cycle and the second detection time is a time when the laser beam emitted by another one of the plurality of the beam emitting points is detected at the predetermined beam detection position during a third scanning cycle;
• and
• a scan control means for controlling the beam emitting means to start emitting the plurality of laser beams in the image area with the determined time lags therebetween.

A method for scanning an image area with a plurality of laser beams and forming a plurality of scanning lines in the image area along a predetermined scan direction, comprising the steps of:

• emitting a plurality of laser beams that reach the image area with respective time lags therebetween;
• determining at least one of the time lags by generating a first time period between a reference detection time and a first detection time and a second time period between the first detection time and a second detection time and thereafter subtracting the first time period from the second time period, wherein the reference detection time is a time when a laser beam emitted by one of the plurality of the beam emitting points is detected at a predetermined beam detection position during a first scanning cycle and the first detection time is a time when the laser beam emitted by the one of the plurality of the beam emitting is detected at the predetermined beam detection position during a second scanning cycle and the second detection time is a time when the laser beam emitted by another one of the plurality of the beam emitting points is detected at the predetermined beam detection position during a third scanning cycle;
• and
• controlling the plurality of laser beams to start emitting in the image area with the determined time lags therebetween.