Magnetic material detecting device
View Patent ↗A magnetic material detecting 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, and which includes 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, in which the dummy coil is disposed at a position where the electromagnetic induction is generated.
1. A magnetic material detecting 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,
wherein the dummy coil is disposed at a position where the electromagnetic induction is generated, and
the dummy coil has no electrically conductive connection to a driving circuit.
2. The magnetic material detecting device according to claim 1 , wherein the magnetizing coil and the dummy coil are wound in the same direction.
3. The magnetic material detecting device according to claim 1 , wherein plural magnetizing coils are provided, and the dummy coil is disposed between the plural magnetizing coils.
4. The magnetic material detecting device according to claim 1 , wherein the magnetizing coil or the dummy coil is disposed on a cover which covers a medium having the magnetic material.
5. The magnetic material detecting device according to claim 4 , wherein a detection control part is provided which detects the magnetic material in association with an opening and closing operation of the cover.
6. The magnetic material detecting device according to claim 1 , wherein the magnetizing coil or the dummy coil is disposed below a support which supports a medium having the magnetic material.
7. The magnetic material detecting device according to claim 1 , wherein the magnetizing coil or the dummy coil is disposed on a passage through which a medium having the magnetic material moves.
8. The magnetic material detecting device according to claim 1 , further comprising:
an image information reading part which reads image information of a medium having the magnetic material, and
a control part which controls an image information reading operation according to a result of the detection of the magnetic material.
9. The magnetic material detecting device according to claim 1 , further comprising:
an image information reading part which reads and outputs image information of a medium having the magnetic material, and
a control part which controls an image information output operation according to a result of the detection of the magnetic material.
10. The magnetic material detecting device according to claim 1 , further comprising:
an image information reading part which reads image information of a medium having the magnetic material,
an image forming part which forms an image on a medium according to the read image information, and
a control part which controls an image forming operation according to a result of the detection of the magnetic material.
11. The magnetic material detecting device according to claim 1 , further comprising:
an image information reading part which reads image information of a medium having the magnetic material, wherein:
the image information reading part does not read the image information when the magnetic material is detected.
12. The magnetic material detecting device according to claim 1 , further comprising:
an image information reading part which reads and outputs image information of a medium having the magnetic material, wherein:
the image information reading part does not output the read image information when the magnetic material is detected.
13. The magnetic material detecting device according to claim 1 , further comprising:
an image information reading part which reads image information of a medium having the magnetic material, and
an image forming part which forms an image on a medium according to the read image information, wherein: the image forming part does not form an image when the magnetic material is detected.
14. The magnetic material detecting device according to claim 1 , wherein the dummy coil is disposed at a position substantially opposed to the magnetizing coil.
15. The magnetic material detecting device according to claim 14 , wherein an induced current which is generated by a magnetic field generated by the magnetizing coil flows in a direction opposite to that of an electric current flowing through the magnetizing coil at a portion opposed to the dummy coil.
16. 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 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,
the dummy coil is disposed at a position where the electromagnetic induction is generated, and
the dummy coil has no electrically conductive connection to a driving circuit.
17. A platen cover of 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,
the dummy coil is disposed at a position where the electromagnetic induction is generated, and
the dummy coil has no electrically conductive connection to a driving circuit.
18. 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,
the dummy coil is disposed at a position where the electromagnetic induction is generated, and
the dummy coil has no electrically conductive connection to a driving circuit.