Image reading device having measuring section with encoder

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.

An image reading device comprising:

• 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 medium detection section provided upstream of the reading section;
• and
• a control section, wherein
• the control section
• measures, using the measuring section, a current distance of after the medium passes through the medium detection section,
• calculates a differential distance between the current distance and a target distance stored in advance,
• specifies a position where the difference distance exists in the image data read by the reading section, and
• performs image correction on the specified position, and
• wherein the encoder scale is provided on a rotation shaft of the second transporting roller.

An image reading device comprising:

• 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,
• 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, and
• a control section that controls transport of the medium, wherein
• the encoder scale is provided on a rotation shaft of the second transporting roller,
• the motor includes a DC motor,
• the first transporting path includes a straight path,
• the second transporting path includes a curved path,
• the control section stops transportation of the medium when a load of the DC motor exceeds a threshold value, and
• the threshold value when the medium is transported along the second transporting path is larger than the threshold value when the medium is transported along the first transporting path.