Patent ID: 7433088
Filing Date: 2008-10-07
Classification: H04N

Abstract:
1. An image reading apparatus, comprising: an image sensor configured to receive light and output an image signal in accordance with image data carried in the light; an A/D converter configure to convert the image signal into a digital signal with reference to a reference voltage; a reference white plate configured to be read so as to generate density data; a correction device configured to correct the digital signal in accordance with shading data; a reference member configured to be read so as to define a readable density limit, said readable density limit correcting density data obtained by reading the reference white plate; a detection device configured to detect a ratio of density of the reference white plate to density of the reference member as density adjustment data, said density being obtained by reading the respective reference member and reference white plate in substantially a same exposure condition; and a control device configured to control the correction device to adjust a density of the digital signal in accordance with the density adjustment data.