<p>An optical disk drive of the type having a fixed optical unit (13) having a light transmitting hole (19) from which a laser beam is emitted, and a movable head (14) having a light receiving hole (20) from which the laser beam is received, wherein the respective outer edges of the light emitting and receiving holes (19, 20) are surrounded by a pair of annular projections (21). The annular projections (21) are engageable with each other to provide a seal therebetween when the head (14) is displaced toward the fixed optical unit (13). The annular projections (21) are preferably made of a cushioning material in which instance they also serve as a cushioning or shock-absorbing member. <IMAGE></p>
