Image reading device, and control method for image reading device correction control

A control method for an image reading device including a first transport roller pair configured to transport a medium along a transport path for transporting the medium, a second transport roller pair located in a first direction with respect to the first transport roller pair on the transport path and configured to transport the medium, a reading sensor located between the first transport roller pair and the second transport roller pair on the transport path and configured to read an image of the medium, the reading sensor being configured to be displaced toward and away from the transport path and being pressed toward the transport path, and a medium detector configured to detect a medium in the second direction with respect to the first transport roller pair in the transport path, the medium detector is an optical sensor including a light emitter and a light receiver, the method comprising:

• a first reading operation of reading the medium while transporting the medium in the first direction,
• a second reading operation of reading the medium while transporting the medium in a second direction opposite to the first direction,
• a combination process of combining a first area that is a part of image data acquired through the first reading operation with a second area that is a part of image data acquired through the second reading operation, to acquire image data of one page,
• a first detection process of detecting a light reception intensity in the light receiver when a light emission intensity of the detection light in the light emitter is set as a first intensity;
• a second detection process of detecting a light reception intensity in the light receiver when the light emission intensity of the detection light in the light emitter is set to a second intensity higher than the first intensity,
• acquiring a difference R between a light reception intensity in the light receiver in the first detection process and a light reception intensity in the light receiver in the second detection process, and
• executing the image correction control when a difference between a maximum value and a minimum value of the difference R exceeds a threshold value.

An image reading device comprising:

• a first transport roller pair configured to transport a medium along a transport path for transporting the medium;
• a second transport roller pair located in a first direction with respect to the first transport roller pair on the transport path and configured to transport the medium;
• a reading sensor located between the first transport roller pair and the second transport roller pair on the transport path and configured to read an image of the medium;
• and
• a controller configured to control the first transport roller pair, the second transport roller pair, and the reading sensor;
• and
• a background plate serving as a portion read by the reading sensor at a position facing the reading sensor and being used for shading correction, wherein
• the reading sensor is configured to be displaced toward and away from the transport path and is pressed toward the transport path,
• the controller is configured to execute image correction control after performing a first reading operation of reading the medium while transporting the medium in the first direction, and
• the image correction control includes a second reading operation of reading the medium while transporting the medium in a second direction opposite to the first direction,
• a combination process of combining a first area that is a part of image data acquired through the first reading operation with a second area that is a part of image data acquired through the second reading operation, to acquire image data of one page,
• the reading sensor and the background plate extend further outside than a medium having a maximum size in a width direction intersecting a transport direction of the medium, and
• the controller reads the background plate during execution of the first reading operation, and executes the image correction control when an amount of change in luminance exceeds a threshold value.

An image reading device comprising:

• a first transport roller pair configured to transport a medium along a transport path for transporting the medium;
• a second transport roller pair located in a first direction with respect to the first transport roller pair on the transport path and configured to transport the medium;
• a reading sensor located between the first transport roller pair and the second transport roller pair on the transport path and configured to read an image of the medium;
• and
• a controller configured to control the first transport roller pair, the second transport roller pair, and the reading sensor, wherein
• the reading sensor is configured to be displaced toward and away from the transport path and is pressed toward the transport path,
• the controller is configured to execute image correction control after performing a first reading operation of reading the medium while transporting the medium in the first direction, the first reading operation acquiring first image data including a first image disturbance area caused by a movement of the reading sensor, and
• the image correction control includes a second reading operation of reading the medium while transporting the medium in a second direction opposite to the first direction, the second reading operation acquiring second image data including a second image disturbance area caused by a movement of the reading sensor, and
• a combination process of combining a first area that is a part of the first image data acquired through the first reading operation with a second area that is a part of the second image data acquired through the second reading operation, to acquire image data of one page, the combination process removing the first and second image disturbance areas from the image data of the one page.