Patent ID: 6992279

Claim:
A method for adjusting a multi-beam source unit including a multi-beam laser diode including a stem having a pair of cutout portions configured to define a virtual straight line and a plurality of light emitting points positioned substantially in a straight line with respect to each other and configured to radiate laser beams, and a collimator lens configured to collimate the laser beams, the multi-beam source unit configured to be set to a scanning optical system assuming that when the position of the plurality of light emitting points coincides with the virtual straight line, the position of the plurality of light emitting points coincides with a predetermined standard design line, the method comprising: measuring a state of the position of the plurality of light emitting points with respect to the predetermined standard design line based on beam spots corresponding to the plurality of light emitting points on an image recording surface; and rotating the multi-beam laser diode about an optical axis of the scanning optical system to align the position of the plurality of light emitting points with the predetermined standard design line.