Patent attributes
A chuck portion provided to keep a fixed positional relation with respect to a housing, holds a light source unit detachably. This chuck portion is displaced from an advanced position to a retracted position to displace the light source unit which is in a provisional position with respect to the housing, in a direction being away from the housing along a reference axis and the light source unit is retracted from the housing. In a state where the light source unit which is in this position is held by the chuck portion, the light source unit is slid and displaced in a direction crossing the reference axis with respect to the housing, angularly displaced about the reference axis and an axis crossing the reference axis, and then fixed to the housing.
