Browse Prior Art Database

Method for Minimizing a Track Miss Count

IP.com Disclosure Number: IPCOM000104624D
Original Publication Date: 1993-May-01
Included in the Prior Art Database: 2005-Mar-19
Document File: 2 page(s) / 55K

Publishing Venue

IBM

Related People

Kagami, N: AUTHOR [+2]

Abstract

Disclosed is a method for an optical disk drive to minimize the track miss count due to the one byte mirror area of the pre-formatted disk. The disclosed method is widely applicable to any optical disk drive which has the capability of the direct track access using track error signal (TES) counting.

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Method for Minimizing a Track Miss Count

      Disclosed is a method for an optical disk drive to minimize the
track miss count due to the one byte mirror area of the pre-formatted
disk.  The disclosed method is widely applicable to any optical disk
drive which has the capability of the direct track access using track
error signal (TES) counting.

      The disclosed method will be best understood with reference to
the drawings which schematically shows optical disk grooves and a
laser beam spot movement during track access.  The standard
pre-formatted optical disk has the one byte mirror area per sector
which is called the tracking offset detection flag (ODF).  If the
laser beam spot runs across the ODF very fast to achieve faster track
access, the track crossing signal will be missed at the ODF area as
shown in Fig. 1 and a track counter will miss the one count.

      To prevent these track miss counting, the disclosed method uses
Pseudo Pulse Generator 1 located between peak pulse detector
consisting of a positive peak comparator 2 and a negative peak
comparator 3 and a track counting logic 4 as shown in Fig. 2.  Pseudo
Pulse Generator 1 is the logic circuit which generates the pseudo
peak pulse as shown in Fig. 3.  If the two same side peak pulses (for
instance Positive Peak) are detected sequentially, the logic will
generate one set of the peak pulses (Positive and Negative Peaks) by
inverting the first peak pulse for some period.  Therefore the trac...