Casing for optical scanning device, including positioning mechanism that positions main body on upper side with respect to main body on lower side, in horizontal and height directions, and optical scanning device having such casing

A casing for an optical scanning device, configured to accommodate therein a scanning optical system, the casing comprising:

• a main body including an opening formed in an upper face;
• a lid that closes the opening of the main body;
• a first positioning mechanism that positions, when a plurality of the main bodies are stacked in a plurality of stages without the lid attached, a main body on an upper stage in a horizontal direction and a height direction, with respect to a main body on a lower stage;
• and
• a second positioning mechanism that positions, when a plurality of casings each having the lid attached to the main body are stacked in a plurality of stages, a casing on an upper stage in the horizontal direction and the height direction, with respect to a casing on a lower stage,
• wherein the first positioning mechanism includes:
• a plurality of first engaging portions formed on a lower end portion of the main body;
• and
• a plurality of first engaging counterparts formed on an upper end portion of the main body, to be opposed to the respective first engaging portions,
• the second positioning mechanism includes:
• a plurality of second engaging portions formed on the lower end portion of the main body;
• and
• a plurality of second engaging counterparts formed on an upper end portion of the lid, to be opposed to the respective second engaging portions,
• when the main bodies are stacked in a plurality of stages without the lid attached, the main body on the upper stage is positioned with respect to the main body on the lower stage in the horizontal direction and the height direction, through engagement between a first engaging portion and a first engaging counterpart, and
• when the casings each having the lid attached to the main body are stacked in a plurality of stages, the casing on the upper stage is positioned with respect to the casing on the lower stage in the horizontal direction and the height direction, through engagement between a second engaging portion and a second engaging counterpart.