| 摘要 |
<p>[Problem] To resolve the problems that come with increasing playback speed and to resolve the problems with phase difference between signals (A) and (B) and signals (C) and (D) generated reliant on pit depth while ensuring that tracking errors can be stably detected from reception signals that deteriorate along with increased recording density of the optical recording medium. [Solution] When the same divided areas (A) to (D) as with the DPD method are defined for a four way receiver and when binarized signals of the received signals of the areas (A) to (D) are designated as signals (A) to (D) the exclusive OR is calculated for: <1> an undelayed signal (A) and a delayed signal (C) <2> a delayed signal (A) and an undelayed signal (C) <3> an undelayed signal (B) and a delayed signal (D) and <4> a delayed signal (B) and an undelayed signal (D); and a tracking error signal is obtained based on the calculation (<1>+<3>) (<2>+<4>). The above described problems are thereby resolved.</p> |
