Patent ID: 7533959

Claim:
A medium position determining device, comprising: a sensor that is configured to detect at least a first side edge of the recording medium; a scanning carriage that is configured to move in a reciprocating manner in a scanning direction, wherein the sensor is mounted to the scanning carriage; and a controller that is configured to move the scanning carriage and to determine a position of the scanning carriage with respect to the recording medium when the scanning carriage moves in the scanning direction, wherein when the sensor detects at least the first side edge of the recording medium, the controller is configured, when the scanning carriage performs scanning for determining the medium position, to: move the scanning carriage from a particular position outside the recording medium to a first position within the recording medium via a further position corresponding to the first side edge of the recording medium at a first speed in the scanning direction; determine that the scanning carriage is in first position; and move the scanning carriage in the scanning direction at a second speed that is greater than the first speed after the controller determines that the scanning carriage is in the first position.