| CPC B65H 7/12 (2013.01) [B65H 7/20 (2013.01); H04N 1/6016 (2013.01)] | 11 Claims |
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1. An image reading apparatus comprising:
a transport section configured to transport a carrier sheet in a predetermined transport direction, the carrier sheet having a junction at which peripheries of two sheets are partly joined together, the sheets having respective transparent areas between which an original sheet is to be interposed;
a reader configured to read a target object being transported by the transport section; and
a controller that acquires image data, the image data being generated as a result of reading the target object with the reader,
the junction having a window that transmits light,
the controller being configured to perform a window height detection process and a window width detection process, based on binary image data generated as a result of a binarization process, in the window height detection process a window height indicating a length of the window in the transport direction being detected, in the window width detection process a window width indicating a length of the window in a width direction being detected, the width direction intersecting the transport direction, in the binarization process a predetermined color generated as a result of reading the window being converted into a first color, and a color other than the predetermined color being converted into a second color,
wherein when a total height of a first area and a plurality of second areas falls within a range from a predetermined window height lower limit to a predetermined window height upper limit in the window height detection process, the controller determines that detection of the window height is successful, in the first area a plurality of pixels in the second color being sequentially arrayed in the transport direction, in the second areas a plurality of pixels in the first color being sequentially arrayed in the transport direction, the second areas being arranged with the first area therebetween in the transport direction,
when a first color width falls within a range from a predetermined window width lower limit to a predetermined window width upper limit in the window width detection process, the controller determines detection of the window width is successful, the first color width indicating a length of an area in which a plurality of pixels in the first color are sequentially arrayed in the width direction,
when the detection of both the window height and the window width is successful, the controller determines that the target object is the carrier sheet, and
when the detection of at least one of the window height and the window width is unsuccessful, the controller determines that the target object is not the carrier sheet.
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