Patent ID: 8310736
Filing Date: 2012-11-13
Classification: H04N

Abstract:
1. An image reading device comprising: a platen configured to allow a document to be placed thereon; a reading device including a light source for emitting light toward the document placed on the platen, the reading device being configured to read the document on a basis of the light emitted from the light source and reflected by the document; a reference member configured to reflect the light emitted from the light source; a selecting device configured to select one of a plurality of reading modes that are different from each other in brightness of the light source when reading the document; a light-source adjusting device configured to adjust brightness of the light source to a brightness corresponding to the one of the plurality of reading modes selected by the selecting device, wherein the light-source adjusting device causes the reading device to read the reference member and adjusts a light-source adjusting value based on a result of the reading; a storage configured to store a reference adjusting value and converting information, the reference adjusting value being the light-source adjusting value adjusted in a state where external light is not incident on the platen in a reference mode of the plurality of reading modes, the converting information being for converting the reference adjusting value of the reference mode into the reference adjusting value of another one of the plurality of reading modes; a first converting device configured to refer to the converting information and convert the reference adjusting value of the reference mode into the reference adjusting value of the selected reading mode; and a determining device configured to determine a presence or an absence of external light incident on the platen, wherein the determining device compares the reference adjusting value with the light-source adjusting value, the reference adjusting value of the selected reading mode being converted by the first converting device, the light-source adjusting value being adjusted by the light-source adjusting device.