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:
Oct. 20, 1987
Filed:
Oct. 04, 1985
Mitsumi Katoh, Hamamatsu, JP;
Nippon Gakki Seizo Kabushiki Kaisha, Hamamatsu, JP;
Abstract
A digital filter is provided between a tone signal generation circuit which supplies a digital tone signal in accordance with a first sampling frequency and a sampling circuit which resamples this digital tone signal in accordance with a second sampling frequency which is lower than the first sampling frequency. This digital filter filters the input digital tone signal with such amplitude-frequency characteristics as to be able to substantially remove an aliasing noise produced due to the second sampling frequency (e.g., with low-pass filter characteristics having a cut-off frequency which is 1/2 the second sampling frequency). This removes high frequency components producing an aliasing noise from the digital tone signal before it is applied to the resampling circuit whereby generation of the aliasing noise in resampling is prevented. The resampling is performed for adapting the digital tone signal to an operation clock frequency of an effect imparting circuit provided in a posterior stage for imparting, in digital, a tone effect such as a modulation effect to the digital tone signal.