Patent ID: 8786920
Filing Date: 2014-07-22
Classification: H04N

Abstract:
1. An image reading apparatus, comprising: a light source constructed to illuminate an original; a color sensor and a monochrome sensor constructed to receive light reflected from the original illuminated by the light source to output an image signal, the color sensor being a sensor constructed to output a color image signal, and the monochrome sensor being a sensor constructed to output a monochrome image signal; an AD converting portion constructed to convert the color image signal from the color sensor to a digital image signal based on a first black level and to convert the monochrome image signal from the monochrome sensor to a monochrome digital image signal based on a second black level; a reference member; and a setting portion constructed to: set the first black level based on a color digital image signal from the color sensor with the light source turned off; set a first light intensity setting value of the light source for reading an image using the color sensor based on a color digital image signal from the color sensor receiving light reflected from the reference member with the light source turned on; set the second black level based on a monochrome image digital signal from the monochrome sensor with the light source turned off; and calculate a second light intensity setting value of the light source for reading an image using the monochrome sensor from the first light intensity setting value.