Patent ID: 6639696
Filing Date: 2003-10-28
Classification: H04N

Abstract:
An image reading apparatus comprising:a light source for illuminating an original object to be read; focussing means provided with a diaphragm capable of altering the width of the luminous flux of a light beam projected through the diaphragm, and for focussing an image recorded on said original document to be read; an image sensor for separating said image recorded on said original document to be read, reading said image, and outputting said image as image data when a light which has passed through said focussing means is projected onto said image sensor; and control means for controlling the state of said diaphragm for adjusting the width of said luminous flux in accordance with the reading determining conditions of said original object to be read, wherein one of said reading determining conditions is a focusing magnification of said focusing means and said control means controls the state of said diaphragm so that the higher said focusing magnification, the smaller the width of said luminous flux.