Reading device setting reading start position by reading reference hole having L-shape

A reading device comprising:

• a light transmissive plate having a front surface on which an original is placed, and a back surface;
• a peripheral frame located adjacent to the light transmissive plate, the peripheral frame including a hack surface in which a reference hole is formed, the reference hole having first and second segment, the first segment including first inside edge and the second segment including a second inside edge intersecting with the first inside edge at an angle to define an inside part of the reference hole;
• a reading sensor provided to face the back surface of the light transmissive plate and the back surface of the peripheral frame, the reading sensor being configured to read an image while moving over a range including the light transmissive plate and the peripheral frame;
• and
• a controller configured to perform:
• controlling the reading sensor to read a reading range including the reference hole to obtain a read image;
• determining a reference position in the reading range based on the read image obtained in the controlling, the reference position being determined to an intersection between the first inside edge and the second inside edge;
• and
• setting a reading start position based on the reference position in the reading range, the reading start position being a position from which the reading sensor starts moving when the reading sensor reads the original.