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. 03, 1992
Filed:
Dec. 23, 1991
Toshio Kanai, Takatsuki, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A power supply circuit for a CRT display device includes a low-voltage power supply switching circuit for supplying power to a horizontal oscillation circuit of the CRT display device, and a high-voltage power supply switching circuit for supplying power to high-voltage circuits of the CRT display device. The low-voltage power supply switching circuit includes an oscillator and a switching transistor. The oscillator is triggered by an output of the horizontal oscillation circuit, and the conductive state of the switching transistor is controlled according to an output of the oscillator. The high-voltage power supply switching circuit includes a switching transistor. The conductive state of the switching transistor of the high-voltage power supply switching circuit is controlled according to an output of the low-voltage power supply switching circuit. As such, the switching operations of the low-voltage and high-voltage power supply switching circuits is carried out at a same frequency and in synchronism with the output of the horizontal oscillation circuit.