Patent ID: 8305652
Filing Date: 2012-11-06
Classification: H04N

Abstract:
1. An image reading apparatus comprising: a carriage having a linear light source operable to emit light onto a surface of a document sheet placed on a platen glass; an image sensor operable to receive part of the emission light reflected from the surface of the document sheet; a carriage drive mechanism operable to move the carriage in a first direction and a second direction, the first direction being orthogonal to a longitudinal direction of the linear light source, and the second direction being reverse to the first direction; a reference pattern member having a reference pattern and disposed at a position within a travel path of the carriage, such that the reference pattern is detectable by the image sensor; a nonvolatile storage unit; a data-write controller operable to (i) judge whether the carriage is currently located in a first area or a second area that are divided by a boundary defined in advance for acquiring information indicating the current location of the carriage and (ii) write an update of the current location information into the nonvolatile storage unit each time the carriage is moved across the boundary between the first and second areas, the boundary coinciding with the position of the reference pattern member or with a position shifted toward the first direction from the reference pattern member, the first area being located toward the first direction, and the second area being located toward the second direction; and a carriage controller operable to, immediately upon power supply to the image reading apparatus, (i) control the carriage drive mechanism to move the carriage toward the reference pattern member based on the current location information held in the storage unit, and (ii) control, when the image sensor detects the reference pattern, the carriage drive mechanism to move the carriage in the second direction to a home position that is located a predetermined distance away from the reference pattern member.