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:
Nov. 02, 1999
Filed:
Apr. 24, 1997
Akira Shishido, Shiga, JP;
NEC Corporation, Tokyo, JP;
Abstract
A CRT system is provided, preventing the resolution on a phosphor screen from degrading due to the characteristic or performance variation and/or deviation of an electron gun. The electron gun has cathodes for emitting R, G, and B electron beams. First and second focusing electrodes focus the electron beams onto a phosphor screen. A drive unit has a power supply for supplying first and second focusing voltages to the first and second focusing electrodes, respectively. The second focusing voltage is an ac voltage with a parabolic waveform. The first focusing voltage is a dc voltage generated by dividing the second focusing voltage with the use of a resistor. A difference between the first and second focusing voltages generates an electrostatic quadruple lens in a space between the first and second focusing electrodes. The difference between the first and second focusing voltages is adjusted by changing the parabolic waveform of the second focusing voltage, thereby controlling the action of the electrostatic quadruple lens to compensate defocusing of the electrostatic quadruple lens.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile