Patent Document ID: 4728929
Application ID: 06782304

Base Claim:
1. An apparatus for encoding binary data comprising: a converting means for converting binary data words each containing N data bits (wherein N is an integer larger than (1) to binary channel words each containing M data bits (wherein M is an integer larger than N); and an NRZI modulating means for modulating said channel words into NRZI coded channel codes, wherein said converting means holds a specific data word which satisfies at least one of a condition that the specific data word has a specific bit pattern and a condition that the specific data word has a specific relationship to adjacent data words; converts said held specific data word to an established channel word so that absolute value of digital sum variation of previously encoded binary data is reduced when another specific data word which satisfies at least one of said conditions has been inputted; and outputs said established channel word after at least a delay time required to convert said held specific data word to said established channel word, and wherein, if a predetermined number of data words which are convertible to channel words in real time have been inputted before said another specific data word is inputted, said converting means converts said held specific data to said established channel word so that absolute value of digital sum variation of previously encoded binary data is reduced when said predetermined number of data words have been inputted.

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Claim 7:
7. An apparatus according to claim 1, wherein said converting means comprises: a data word storage memory for storing said data words and their attributes; a means for converting said data words stored in said memory to said channel words with reference to said attributes; a pointer register for storing an address in which said specific data word and its attribute are stored in said memory; and a means for changing said attribute of said specific data word stored in said address stored in said pointer register so that said specific data word can be converted to said established channel word.