| 摘要 |
PURPOSE:To decrease the ratio of the areas occupied by clock tracks on a recording medium and to improve the recording density by providing an information recording area having plural recording tracks and a guide track and a clock signal recording area having a clock signal recording area having >=one clock track corresponding to the recording tracks of the recording area separately. CONSTITUTION:An optical information recording medium 1 consists of an information recording area 2 where a recording track 6 and a guide tack 4 are alternately arranged and of a clock signal recording area 3 having at least >=one clock track 5 with respect to the recording rack 6 of the area 2 separately. Light beams B1, B2, B3 from an optical head are radiated onto the area 2 of the medium 1 in case of recording/reproduction and the tracking direction of an optical head is corrected while two guide tracks 4 clipping the recording track 6 are traced by the beams B1, B2, B3 and recording/reproduction to/from the track 6 is applied by using the beam B2 to apply the focusing of the head at the same time. |
