Magnetic material detecting device

An image reading device which detects a magnetic material by applying a magnetic field to the magnetic material and detecting a magnetic field generated from the magnetic material by the applied magnetic field, comprising:

• a magnetizing coil which emits a magnetic field that excites the magnetic material, and
• a dummy coil which generates a magnetic field that excites the magnetic material by electromagnetic induction caused by the magnetic field emitted from the magnetizing coil, and
• a platen cover, wherein:
• the magnetizing coil or the dummy coil is disposed on the platen cover, and
• the dummy coil is disposed at a position where the electromagnetic induction is generated.

An image reading device which detects a magnetic material by applying a magnetic field to the magnetic material and detecting a magnetic field generated from the magnetic material by the applied magnetic field, comprising;

• a magnetizing coil which emits a magnetic field that excites the magnetic material,
• a dummy coil which generates a magnetic field that excites the magnetic material by electromagnetic induction caused by a magnetic field emitted from the magnetizing coil, and
• a platen glass, wherein:
• the magnetizing coil or the dummy coil is disposed below the platen glass, and
• the dummy coil is disposed at a position where the electromagnetic induction is generated.