Projection device having rotation lock mechanism and projection lens having rotation lock mechanism

A projection device comprising:

• an electro-optical element;
• a drive housing that stores the electro-optical element and includes a central portion and a protruding portion protruding from the central portion;
• a recessed portion;
• a projection lens that is disposed in the recessed portion, projects light applied from the electro-optical element onto a projection target, and includes a first rotation mechanism;
• a first lock unit that is provided on the projection lens and switches a state of the first rotation mechanism between rotatable and not rotatable;
• and
• fans that are disposed in the drive housing and draw in or discharge gas, wherein
• the recessed portion and the protruding portion are adjacent to each other in a first direction,
• the projection lens is provided so as to extend to the recessed portion from the drive housing in a second direction crossing the first direction,
• the central portion includes a first A side surface that is provided in a first A direction corresponding to one side in the first direction and a second A side surface that is provided in a first B direction corresponding to the other side in the first direction,
• the protruding portion includes a first B side surface in the first A direction and includes a second B side surface, which faces the projection lens, in the first B direction,
• the fans face the second A side surface and the second B side surface, and
• at least one of the fans, the projection lens and the second B side surface overlap along an x axis, the x axis being normal to the second B side surface.