The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 29, 1999
Filed:
Dec. 11, 1996
Shin-ichi Tanaka, Kyoto, JP;
Toshiyuki Shimada, Hyogo, JP;
Tadashi Kojima, Kanagawa, JP;
Koichi Hirayama, Kanagawa, JP;
Yoshiaki Moriyama, Saitama, JP;
Fumihiko Yokogawa, Saitama, JP;
Takao Arai, Kanagawa, JP;
Toshifumi Takeuchi, Kanagawa, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Kabushiki Kaisha Toshiba, Kanagawa, JP;
Pioneer Electronic Corporation, Tokyo, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A digital modulation apparatus applies a method for converting data words to runlength-limited code words using plural conversion tables. The data words are converted to code words that significantly suppress the low frequency component of the final nonreturn-to-zero inverted signal. This digital modulation apparatus includes ROM tables for storing plural conversion tables containing the runlength-limited code words corresponding to the data words; end-runlength memories and evaluators for determining whether the runlength-limit constraints are satisfied in the interconnection between two consecutive code words when the data words to be converted are supplied; and a DSV controller for storing each of the code words that can be selected from two conversion tables to buffer memories when the runlength-limit constraints are satisfied, and selecting the code words wit the greatest effect suppressing the low frequency component in the obtained signal when the code words are NRZI converted.