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. 14, 2011
Filed:
Jun. 29, 2007
Byung-hun Kim, Suwon-si, KR;
Byung-Hun Kim, Suwon-si, KR;
Samsung Electro-Mechanics Co., Ltd., Suwon-si, KR;
Abstract
A method and apparatus to detect a print location error using print dots. The method includes transforming values of pixels of a first image into frequency domains, where a plurality of print dots are arranged at predetermined intervals in the first image; transforming values of pixels of a second image, where the second image is obtained by actually printing the first image using an inkjet head; detecting 2D (2-dimensional) cross power spectral densities of the frequency-domain values of the first and second images; calculating 2D cross correlation values by transforming the 2D cross power spectral densities into time domain; and detecting error coordinates representing the distances between the print dots of the second image and the first image from the time-domain cross correlation values. Accordingly, it is possible to perform coordinates compensation by detecting errors between ideal print dots and actually printed print dots so that an image sensor can move exactly to print dots in order to sense print dots sprayed from an inkjet head that is newly exchanged in an image forming apparatus.