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. 20, 1989
Filed:
Jun. 11, 1987
Takeshi Adachi, Hamamatsu, JP;
Kazuo Masaki, Hamamatsu, JP;
Yamaha Corporation, Hamamatsu, JP;
Abstract
In storing digital tone waveshape data in a waveshape memory, sampled tone waveshape data is stored in the memory by previously elevating the level of frequency components in a predetermined high frequency region. This predetermined high frequency region corresponds to a frequency region to which quantization noise components belong. The tone waveshape data stored in the waveshape memory in this manner has the signal level of the component of the region including the quantization noise components reinforced as compared with the original tone waveshape. The tone waveshape data read out from the waveshape memory is applied to a filter of a characteristic which restrains the level of the component in the predetermined high frequency region. The level of the quantization noise components belonging to the predetermined high frequency region contained in the tone waveshape data thereby is restrained. On the other hand, the level of the signal components of the predetermined high frequency region is restored to the original level by this restraining of the level. Thus, the quantization noise can be eliminated without impairing the level of the signal component.