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. 12, 1989
Filed:
Jan. 19, 1988
Applicant:
Inventors:
Arata Obayashi, Hino, JP;
Ryohei Oba, Hino, JP;
Assignee:
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G08B / ;
U.S. Cl.
CPC ...
3403 / ; 3403 / ;
Abstract
A tone signal is formed by repeatedly reading out digital data stored in a memory device. Thus a predetermined tone wavefrom signal is stored in the memory device as data corresponding to the amplitude value at a plurality of sampling points and the data are repeatedly read out at a predetermined speed. A quasi sine wave signal is formed based on the read out signal. Harmonic components are eliminated from the quasi sine wave signal with a lowpass filter, thereby forming a desired tone signal.