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:
Aug. 15, 1995
Filed:
Mar. 24, 1994
Masatada Wachi, Hamamatsu, JP;
Masahiro Shimizu, Hamamatsu, JP;
Yamaha Corporation, , JP;
Abstract
A memory stores waveform sample data for plural sample points forming a given tone waveform, and one of the stored waveform sample data stored for every two adjacent sample points is expressed in PCM representation while the other is in difference value representation that is based on the PCM values stored for two sample points on both sides of the sample point of the other sample data. The number of bits in each address of the memory is greater than the number of bits in each of the PCM data, and each of the PCM data is stored at some bit positions of one address, while the difference value data is stored at the remaining bit positions of one or more addresses. The waveform sample data stored in the memory are read out at a readout rate corresponding to a designated pitch and in the order of the sample points, but when at least the waveform sample data expressed in the difference value is read out, the PCM data stored for two sample points adjacent thereto are also read out along with the difference value data. The read-out difference data is reproductively demodulated into PCM representation, using the PCM data read out along with the difference data.