Image reading device, and control method for image reading device correction control
A control unit of an image reading device is configured to execute image correction control after performing a first reading operation of reading a medium while transporting the medium in a 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, and a combination process for combining a first area serving as a part of image data acquired through the first reading operation with a second area serving as a part of image data acquired through the second reading operation to acquire image data of one page.
1 . 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;
a controller configured to control the first transport roller pair, the second transport roller pair, and the reading sensor; 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, 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 medium detector is an optical sensor including a light emitter and a light receiver,
the controller is configured to execute
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; and
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, and
the controller further acquires 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
executes the image correction control when a difference between a maximum value and a minimum value of the difference R exceeds a threshold value.
2 . The image reading device according to claim 1 , wherein
the two rollers constituting the first transport roller pair are both driven by a drive source, and
the two rollers constituting the second transport roller pair are both driven by the drive source.
3 . The image reading device according to claim 1 , wherein
one of the two rollers constituting the first transport roller pair that is on the same side as the reading sensor with respect to the transport path is a displacement roller configured to move toward and away from the other roller,
the displacement roller is provided with an engagement portion, the engagement portion being a portion displaced integrally with the displacement roller and being configured to engage with the reading sensor, and
when the displacement roller is separated from the other roller, the engaging portion displaces the reading sensor together with the displacement roller.
4 . The image reading device according to claim 1 , further comprising:
a guide portion in the second direction with respect to the reading sensor on the transport path, the guide portion being configured to guide the medium transported in the first direction to a position facing the reading sensor, wherein
the guide portion is configured to be displaced toward and away from the transport path, and is provided integrally with the reading sensor.
5 . 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.
6 . 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.
7 . The image reading device according to claim 6 , wherein
the two rollers constituting the first transport roller pair are both driven by a drive source, and
the two rollers constituting the second transport roller pair are both driven by the drive source.
8 . The image reading device according to claim 6 , wherein
one of the two rollers constituting the first transport roller pair that is on the same side as the reading sensor with respect to the transport path is a displacement roller configured to move toward and away from the other roller,
the displacement roller is provided with an engagement portion, the engagement portion being a portion displaced integrally with the displacement roller and being configured to engage with the reading sensor, and
when the displacement roller is separated from the other roller, the engaging portion displaces the reading sensor together with the displacement roller.
9 . The image reading device according to claim 6 , further comprising:
a guide portion in the second direction with respect to the reading sensor on the transport path, the guide portion being configured to guide the medium transported in the first direction to a position facing the reading sensor, wherein
the guide portion is configured to be displaced toward and away from the transport path, and is provided integrally with the reading sensor.
10 . 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.
11 . The image reading device according to claim 10 , further comprising:
a DC motor that is a driving source of the first transport roller pair and the second transport roller pair, wherein
the controller executes the image correction control when a load value indicating a load of the DC motor exceeds a threshold value during execution of the first reading operation.
12 . The image reading device according to claim 11 , wherein the controller determines the first area and the second area based on a timing at which the load value exceeds a threshold value.
13 . The image reading device according to claim 10 , further comprising:
a medium detector configured to detect a medium in the second direction with respect to the first transport roller pair in the transport path, wherein
the medium detector is an optical sensor including a light emitter and a light receiver,
the controller is configured to execute
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; and
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, and
the controller further acquires 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
executes the image correction control when a difference between a maximum value and a minimum value of the difference R exceeds a threshold value.
14 . The image reading device according to claim 10 , wherein
one of the two rollers constituting the first transport roller pair is a displacement roller configured to move toward and away from the other roller,
the image reading device comprises a displacement detector configured to detect a displacement of the displacement roller, and
the controller executes the image correction control when a displacement amount of the displacement roller exceeds a threshold value based on detection information of the displacement detector.
15 . The image reading device according to claim 10 , further comprising:
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 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.
16 . The image reading device according to claim 10 , wherein
the controller is configured to acquire information on a type of medium,
types of the medium include a booklet, and
the controller executes the image correction control when the type of the medium is a booklet.
17 . The image reading device according to claim 10 , further comprising:
a display panel configured to display an image, wherein
the controller is configured to execute a preview mode in which transport of the medium is temporarily stopped and an image of the medium read through the first reading operation is displayed on the display panel after execution of the first reading operation, and
the controller, in the preview mode, further causes the display panel to display a user interface allowing a user to select whether to discharge the medium or to perform the image correction control.
18 . The image reading device according to claim 10 , wherein
the two rollers constituting the first transport roller pair are both driven by a drive source, and
the two rollers constituting the second transport roller pair are both driven by the drive source.
19 . The image reading device according to claim 10 , wherein
one of the two rollers constituting the first transport roller pair that is on the same side as the reading sensor with respect to the transport path is a displacement roller configured to move toward and away from the other roller,
the displacement roller is provided with an engagement portion, the engagement portion being a portion displaced integrally with the displacement roller and being configured to engage with the reading sensor, and
when the displacement roller is separated from the other roller, the engaging portion displaces the reading sensor together with the displacement roller.
20 . The image reading device according to claim 10 , further comprising:
a guide portion in the second direction with respect to the reading sensor on the transport path, the guide portion being configured to guide the medium transported in the first direction to a position facing the reading sensor, wherein
the guide portion is configured to be displaced toward and away from the transport path, and is provided integrally with the reading sensor.