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:
May. 13, 2008
Filed:
Oct. 29, 2003
Makoto Matsushima, Hyogo, JP;
Makoto Matsushima, Hyogo, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
A PWM signal generating circuit outputs a stable PWM signal for increasing and deceasing a duty ratio at a predetermined rate within a predetermined period without requiring an improvement of a process capacity of a CPU as compared to a conventional PWM signal generating circuit. The PWM signal generating circuit consists of a plurality of circuit elements each of which outputs a digital signal. A first counter circuit periodically changes a PWM signal output therefrom into an active state. A second counter circuit changes the PWM signal, which has been changed into the active state by the first counter circuit, into an inactive state within each cycle. The second counter circuit increases and decreases an active-to-inactive time period from a time when the PWM signal is changed into the active state to a time when the PWM signal is changed into the inactive state.