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:
Sep. 24, 1991
Filed:
Apr. 10, 1989
Toru Ogawa, Tokyo, JP;
Seijchi Sato, Tokyo, JP;
Namco Ltd., Tokyo, JP;
Abstract
An analog signal synthesizing apparatus includes a waveform memory for storing a plurality of analog signals as PCM data sampled with different sampling frequencies, the amount of PCM data corresponding to plural channels being read from the waveform memory and used to synthesize the analog signals. The analog signal synthesizing apparatus includes an oversampling device for shifting the sampling frequency of the PCM data read from the waveform memory for each channel toward the side of high frequency; a summing device for summing the oversampled PCM data for the respective channel; a D/A converter for converting the summed data into an analog signal; and a low-pass filter for setting a cut-off frequency based on the sampling frequency shifted to the side of high frequency and for eliminating aliasing noises included in the PCM data from the synthesized analog signal. The elimination of the aliasing noises included in the PCM data for each channel is carried out at the common low-pass filter.