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:
Jul. 18, 1995
Filed:
Dec. 15, 1993
Applicant:
Inventors:
Masahiro Kawashima, Takatsuki, JP;
Yutaka Tsutsumi, Neyagawa, JP;
Assignee:
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01J / ;
U.S. Cl.
CPC ...
3153821 ; 315411 ; 363 21 ;
Abstract
In a focus circuit for cathode-ray tube (40) of electromagnetic focusing type, a DC voltage (B4) which is made by dividing CRT anode voltage (B3) by a voltage dividing circuit (27) is compared with a reference voltage (B6) by an anode voltage variation component detection circuit (29), thereby to output therefrom a signal (Ve) of anode voltage variation component. This signal (Ve) and static focus adjusting DC voltage (B7) are summed and amplified by an output amplifier 30, which issues a current for correcting focus to electromagnetic focusing coil (31).