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
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