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. 01, 1990
Filed:
May. 18, 1989
Kazuya Maeshima, Nagasaki, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
The present invention relates to a scanning line converter which converts the number of scanning lines into a multiple thereof. Write-clock-pulses and read-clock-pulses for controlling read/write accesses to a video memory, are produced on a basis of signals obtained by differentiating both a horizontal synchronizing signal and a double-speed horizontal synchronizing signal with respect to stable master clock pulses. The double-speed horizontal synchronizing signal is stabilized by a method, wherein double-speed horizontal oscillation pulses with a multiple frequency of the horizontal synchronizing signal, are delayed and further converted to a saw-tooth-wave signal, and the phase errors between the saw-tooth-wave signal and the horizontal synchronizing signal are fed back to the double-speed horizontal pulse oscillator.