| 摘要 |
PURPOSE:To promote the general purpose property by correcting a focus shift due to a different board quality of an information recording medium such as a board material and a board thickness. CONSTITUTION:The subject device is provide with a focus servo means for performing a focus adjustment of an optical pickup and a means for reading a focus shift correcting amt. corresponding to the kind of the board quality discriminated by a discriminating means from a storage means and injecting it into the focus servo means. Then, by discriminating the kind of the board quality of an information recording medium to be used and injecting a focus shift correcting amt. corresponding to the kind of this board quality into the focus servo means, a focus shift due to the different board quality of the information recording medium such as its board material and board thickness is corrected. By this method, the general purpose property of the optical information recording device is promoted. |
