Patent ID: 7388690
Filing Date: 2008-06-17
Classification: H04N

Abstract:
1. A method for calibrating an imaging apparatus configured for scanning a document, said imaging apparatus including a scanner head having an illuminant and a sensor for collecting image data, and a phosphorescent material forming a phosphorescent area located opposite said scanner head, wherein said document is positioned between said scanner head and said phosphorescent area during a scanning operation, said method comprising at least one of: performing an ambient light calibration based on a background light emission intensity level of said phosphorescent area; performing an ambient light time calibration based on a decay constant of said phosphorescent material; performing a horizontal calibration to compensate for irregularities in at least one of said illuminant and said sensor across a width of said phosphorescent area; and performing a vertical calibration to compensate for changes of scanning speed of said scanner head in a lengthwise scanning direction along a length of said phosphorescent area.