Patent ID: 7804919
Filing Date: 2010-09-28
Classification: H04L

Abstract:
1. A run length limiting apparatus, comprising: an input section configured to input, a digital data string including a predetermined number of symbols which have the same number of bits; a search section configured to search for a specific symbol having a pattern that does not match any of the symbols included in the digital data string input to the input section; a calculation section configured to perform an exclusive OR operation between the specific symbol searched for by the search section and each of the symbols included in the digital data input to the input section; an output section configured to output the digital data string calculated by the calculation section together with the specific symbol searched for by the search section; the search section previously has a list of sufficient number of candidates of the specific symbol, and wherein, for the case where predetermined-position bits of each symbol included in the digital data string input to the input section matches a pattern that has previously been set, the search section excludes the matched pattern without change for the candidate list, while in the case were predetermined-position bits of each symbol included in the digital data string input to the input section does not match a pattern that has previously been set, the search section inverts all bits of the symbol and excludes matched patterns, if this pattern matches a pattern that has previously been set, from the candidate list so as to find a specific symbol that does not match any of symbols and any of inverted symbols after a predetermined number of symbols have been input.