Patent ID: 8111433
Filing Date: 2012-02-07
Classification: H04N

Abstract:
1. An image reading device comprising: a reference member; a reading unit that scans an image on a document to obtain image data and that scans the reference member to obtain reference data; a first reference value setting unit that sets a first reference value based on the reference data; a detecting unit that detects a usage state of the reading unit; a second reference value setting unit that sets a second reference value in accordance with the usage state of the reading unit; a determining unit that determines whether or not the first reference value is in a predetermined condition; a pixel value setting unit that sets a pixel value, the pixel value setting unit setting the pixel value based on the image data and on the first reference value, if the determining unit determines that the first reference value is in the predetermined condition; and the pixel value setting unit setting the pixel value based on the image data and on the second reference value, if the determining unit determines that the first reference value is not in the predetermined condition; and a light source that irradiates light on the reference member, wherein the reading unit scans the reference member while the light source is turned on to irradiate light on the reference member, thereby obtaining white reference data, and scans the reference member while the light source is turned off, thereby obtaining black reference data, wherein the first reference value setting unit sets a first white reference value based on the white reference data, and sets a first black reference value based on the black reference data, wherein the second reference value setting unit sets a second white reference value and a second black reference value, wherein the determining unit determines whether or not the first white reference value is in a predetermined white condition, and determines whether or not the first black reference value is in a predetermined black condition, and wherein if the determining unit determines that the first white reference value is in the predetermined white condition and the first black reference value is in the predetermined black condition, the pixel value setting unit sets the pixel value based on the image data, on the first white reference value and on the first black reference value; if the determining unit determines that the first white reference value is not in the predetermined white condition, the pixel value setting unit sets the pixel value based on the image data, on the second white reference value and on the second black reference value; and if the determining unit determines that the first black reference value is not in the predetermined black condition, the pixel value setting unit sets the pixel value based on the image data, on the second white reference value and on the second black reference value.