Abstract: On the side surface of an optical guide plate (104), an engaging protrusion (105) is formed for fixing the optical guide plate (104) on to a frame (101) by fitting the optical guide plate in a recessed portion formed on the frame. The light emitted from an LED (107) enters the optical guide plate (104) from a light-incident end surface and travels in the optical guide plate (104) while spreading in a fan-shape. The engaging protrusion (105) is formed outside the outgoing-angle range of the beam (109) spreading in the fan-shape, thereby preventing occurrence of bright line caused by reflection of light at the corner portion of the base of the engaging protrusion (105).

Abstract: On the side surface of an optical guide plate (104), an engaging protrusion (105) is formed for fixing the optical guide plate (104) on to a frame (101) by fitting the optical guide plate in a recessed portion formed on the frame. The light emitted from an LED (107) enters the optical guide plate (104) from a light-incident end surface and travels in the optical guide plate (104) while spreading in a fan-shape. The engaging protrusion (105) is formed outside the outgoing-angle range of the beam (109) spreading in the fan-shape, thereby preventing occurrence of bright line caused by reflection of light at the corner portion of the base of the engaging protrusion (105).

Abstract: A disk apparatus includes a head, a motor for moving the head to a track position on a disk in response to a motor driving signal, a driving-signal generating section for issuing the motor driving signal to the motor in response to each of an external drive instruction from a host, a first drive instruction and a second drive instruction, each of which includes data indicative of the number of tracks for the head to be moved and data indicative of a direction for the head to be moved to, a detector for detecting that the disk is inserted, a first instruction generating section for issuing the first drive instruction such that the head is positioned on a track 0 position of the disk when the detector detects that the disk is inserted, a first counter for summing the number of tracks of each of the external, first and second drive instructions in consideration of the direction, and a second counter for summing the number of tracks of the external drive instruction in consideration of the direction, a second ins