| 摘要 |
PURPOSE:To ensure the assured recording and reading with a simple constitution, by shifting a head with the rotary driving power of a disk recording medium and at the same time setting an optical reflecting surface and a nonreflecting surface to a driving power transmission member to set them opposite to the head position. CONSTITUTION:The rotary driving power of a driving motor which turns a direct-coupled disk is transmitted via a gear 39, a gear 40 unified with the gear 39, a gear 41, a gear 42 unified with the gear 41 and having a noninterference part 52, a fan-shaped gear 43, etc. Thus a head arm 45 rocks to move a head 44 to the radius direction of the disk. When the disk has a turn, the engagement between the gears 42 and 43 is released by the part 52. Then the arm 45 is reset to its home position by the elastic force of a spring. At the same time, both an optical reflecting part and a nonreflecting part are formed to a sheet 65 unified with the gear 41 to be opposite to the position of the head 44. Thus the arrival of the head 44 to both the home position and to the reading end position is detected sufficiently by a photoelectric transducer 64. In such way, both the recording and reading can be performed assuredly with a simple constitution. |
