Image reading device, image correction method of image reading device, and stopping method of medium transportation for image reading device

An image correction method of an image reading device, the image reading device including:

• a motor,
• a reading section configured to read an image on a medium,
• a first transporting roller that transports the medium in a transport direction by driving force of the motor and that is provided upstream of the reading section in the transport direction,
• a second transporting roller that transports the medium in the transport direction by driving force of the motor and that is provided downstream of the reading section in the transport direction, and
• a measuring section configured to measure, using an encoder sensor, the rotational position of an encoder scale, wherein
• the encoder scale
• is mounted on a rotation shaft of the second transporting roller and
• has a medium detection section provided upstream of the reading section,
• the image correction method of the image reading device comprising:
• measuring, using the measuring section, a current distance of after the medium passes through the medium detection section,
• calculating a differential distance between the current distance and a target distance stored in advance;
• specifying a position where a difference distance exists in the image data read by the reading section;
• and
• executing an image correction on the specified position.

A stopping method of medium transportation for an image reading device, the image reading device including

• a motor,
• a reading section that reads an image on a medium,
• a first transporting roller that transports the medium in a transport direction by driving force of the motor and that is provided upstream of the reading section in the transport direction,
• a second transporting roller that transports the medium in the transport direction by driving force of the motor and that is provided downstream of the reading section in the transport direction,
• a measuring section configured to measure, using an encoder sensor, the rotational position of an encoder scale,
• a third transporting roller that transports the medium in a transporting direction and that is provided downstream of the second transporting roller in the transporting direction,
• a first transporting path through which the medium is transported, the first transporting path including a portion from a nip position of the first transporting roller to a nip position of the second transporting roller, and
• a second transporting path through which the medium is transported, the second transporting path including a portion from the nip position of the second transporting roller to a nip position of the third transporting roller, wherein
• the motor includes a DC motor,
• the encoder scale is provided on a rotation shaft of the second transporting roller,
• the first transporting path includes a straight path, and
• the second transporting path includes a curved path,
• the stopping method of medium transportation for the image reading device comprising:
• stopping transportation of the medium when a load of the DC motor exceeds a threshold value, and
• executing a threshold value in a case where the medium is transported on the second transporting path is set to be larger than a threshold value in a case where the medium is transported on the first transporting path.