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:
Mar. 11, 1980
Filed:
Jan. 23, 1978
Ikuo Kawaguchi, Yokohama, JP;
Hitachi, Ltd., , JP;
Abstract
A pattern signal for sequentially displaying crisscross patterns of three primary colors of red, green and blue is supplied to a color picture tube. Two television cameras pick up the pattern images displayed on the color picture tube through a 1:1 half mirror. The line scanning directions of the first and second television cameras are horizontal and vertical respectively with respect to the CRT display screen. The aspect ratio of the first television camera is selected to be equal to that of the CRT display screen, and the aspect ratio of the second television camera is selected to be equal to the reciprocal of that of the CRT display screen. The image output signals of these two television cameras are selectively supplied to an image processing circuit by a change-over unit. In this image processing circuit, a counter counts the time-related positions of peak values appearing within a specified line scanning period in the image signals supplied through the change-over unit. The degree of convergence is detected by detecting the differences between the time-related peak value positions in the red, green and blue patterns.