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:
Dec. 25, 1979
Filed:
Sep. 11, 1978
Osamu Hamada, Tokyo, JP;
Sony Corporation, Tokyo, JP;
Abstract
In a tone generating apparatus for an electrical music instrument having an array of switches corresponding to respective keys of a keyboard and which are selectively actuable by manipulation of the respective keys, a timing signal generator, preferably including a shift register, has a repetitive operating cycle and is connected with the switches for providing timing signals in response to actuation of the latter, with each of the timing signals occurring at a time during the operating cycle which corresponds to the position of the respective actuated switch in the switch array, an exponential signal generator provides an exponential signal in synchronism with the operating cycle of the timing signal generator, a sample and hold circuit receives the exponential signal and is operative to sample and hold a value of the exponential signal in dependence on the time of occurrence of a timing signal in the operating cycle, and variable frequency oscillator controlled in accordance with the value of the exponential signal which is sampled and held for providing an output oscillation having a frequency determined by a selectively actuated one of the switches.