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. 17, 1980
Filed:
Feb. 22, 1977
Anthony C Ippolito, North Tonawanda, NY (US);
William R Hoskinson, Williamsville, NY (US);
The Wurlitzer Company, DeKalb, IL (US);
Abstract
A portamento system is disclosed for use with an electronic musical instrument, and particularly with a monotonic keyboard instrument which utilizes master oscillator/divider elements for tone generation. The portamento system utilizes a voltage controlled oscillator, and an oscillator control circuit comprising a unique combination of a phase/frequency detector and a circuit for varying and controlling lock up rate and expanding the frequency range of the system which may be either a ramp and hold circuit or a frequency tachometer circuit. The voltage controlled oscillator is thus locked on to the input frequency from the electronic musical instrument with substantially zero phase and frequency error. The system is capable of reaching the input frequency as slowly or as rapidly as desired and will operate over a wide frequency range. A unique system control and interfacing system is also provided whereby the portamento system may be utilized with a plurality of voices of the electronic musical instrument and several modes of operation may be selectively utilized.