| 摘要 |
PURPOSE:To reduce the number of light receiving sensors to make a device small-sized and low-cost by selectively supplying a tracking error signal and the inverted tracking error signal to an irradiation position adjusting means to selectively switch the irradiation position of one light beam to a control track and a recording track on an optical disk. CONSTITUTION:A light receiving sensor 17 is provided in a position B3'' where the light beam (a reflected beam B3) whose irradiation position is controlled to the control track by a tracking error signal St is received. In this case, an inverted tracking error signal St' is supplied to an irradiation position adjusting means 11 instead of the tracking error signal St only at the time of reproducing of recorded information based on switching of a tracking changeover switch means 23 to switch the irradiation position of the light beam B3 from the control track to the recording track. Thus, one light receiving sensor 17 is used for generation of focus and tracking error signals and reproducing of positions information and recorded information. |
