Appeal No. 1998-0601 Application 08/225,322 reading and use by the reference power generator, which is recited in claims 4 and 11. The reference power data PREF is applied to a drive signal generator 103 where it is converted into a read or write driving signal DR and then applied to a light source element. In this conventional apparatus, the light source element is operated at constant power irrespective of pickup position. Consequently, if a tracking error occurs during writing, the previously recorded data is lost by overwriting additional data. The APA does not disclose "operating the optical pickup at a power level suitable for reading data, when an abnormal tracking error occurs" as recited in claim 1 and in similar limitations in claims 4 and 11. Claims 1, 2, 4-6, 11, 12, and 15 over APA and one of Yoshimoto, Ishida, Horie, or Maeda Yoshimoto (col. 14, lines 63-68), Ishida (col. 5, lines 41-59), Horie (col. 3, lines 11-16), and Maeda (col. 4, lines 45-53; col. 7, lines 54-58) disclose that it was known to interrupt the recording operation when the tracking error exceeds either a positive or negative threshold value to avoid the problem of erroneously recording over already recorded - 5 -Page: Previous 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 NextLast modified: November 3, 2007