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:
Jan. 01, 1991
Filed:
Jan. 23, 1989
Applicant:
Inventors:
Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04N / ; H04N / ;
U.S. Cl.
CPC ...
358 60 ; 358 10 ;
Abstract
A focus adjustment changeover circuit for a projection display television receiver having red, green and blue-emission CRTs includes a changeover switch for selecting an operating mode in which a level of current is supplied to the static focus coil of the blue-emission CRT such as to precisely focus the electron beam of that CRT, so that projection lens focus adjustment for that CRT can be easily performed with a test pattern signal being projected, and an operating mode in which the current supplied to that static focus coil causes the electron beam of the blue CRT to be slightly defocused, so that white balance adjustment of the television receiver can be executed while a television picture is projected.