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:
Jun. 07, 1994
Filed:
Mar. 26, 1992
Jun Mochizuki, Fujisawa, JP;
Atsushi Yoshida, Yokohama, JP;
Toshio Asano, Yokohama, JP;
Kinuyo Hagimae, Yokohama, JP;
Daisuke Katsuta, Yokohama, JP;
Teruo Matsuo, Mobara, JP;
Kazuo Majima, Mobara, JP;
Masao Taniguchi, Mobara, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
An apparatus for identifying positions of pixel defects on a display screen, such as a cathode-ray tube or a liquid crystal display, operates to pick up an image signal of a display screen representing a predetermined image with an imaging camera, shift the image signal of the imaging camera by one pixel in one and another directions with respect to the display screen, and obtain a difference of a signal level between a defective portion and a normal portion on the screen, based on the signals obtained when the image signal of the imaging camera is shifted in one and another directions. The apparatus also serves to calculate a relative inclination between the imaging camera and the display screen for obtaining a difference of a signal level between a defective portion and a normal portion of each pixel. The results make it possible to clearly identify the difference of the signal level between the defective portion and the normal portion.