Patent ID: 9019332
Filing Date: 2015-04-28
Classification: G03G,H05K

Abstract:
1. A cover member to be attached to a housing including a bottom portion on which a rotary polygon mirror is mounted and a side wall provided to stand on the bottom portion, the cover member comprising: a closing surface configured to close an opening surrounded by the side wall, the rotary polygon mirror being passed through the opening when the rotary polygon mirror is to be mounted on the bottom portion; at least three protruding portions protruding from the closing surface so as to be located on an inside of the housing in a state in which the cover member is attached to the housing; and a protection portion configured to protect a circuit board fixed to the side wall of the housing, the protection portion having: a first opposed portion opposed to the circuit board and provided to stand on the closing surface; a second opposed portion opposed to the circuit board and protruding with respect to the first opposed portion away from the circuit board; and a connecting portion configured to connect the first opposed portion and the second opposed portion, wherein a length S of the at least three protruding portions from the closing surface in a direction perpendicular to the closing surface and a length T of the first opposed portion in the direction perpendicular to the closing surface satisfy a relation of S>T.