Multi-beam source unit, adjusting method for same, positioning jig for same, assembling method for same, and image forming apparatus having same

摘要

A multi-beam source unit is disclosed wherein an arranged direction of light emitting points of a multi-beam laser diode relative to a horizontal scanning direction of a scanning optical system can be aligned with a predetermined standard design line. In this multi-beam source unit, a base member (30) is formed with a pressing plate mounting portion (41) which has a fitting hole (42) and which supports a multi-beam laser diode (31) rotatably, a cutout portion (47) for aligning the direction of a virtual straight line with the direction of a standard design line is formed in a stem (31B), a positioning groove (41A) which cooperates with the cutout portion (47) to align the direction of the virtual straight line with the direction of the standard design line is formed in the pressing plate mounting portion (41) as a mounting seat portion, a tip of jig (70) inserted through the positioning groove (41A) is brought into engagement with the cutout portion (47), and in this aligned state of the cutout portion (47) with the positioning groove (41A) the multi-beam diode (31) is pressed and fixed to the base member (30) by means of a pressing plate (40) which presses a back side of the stem 31B.