Input device
A magnetic field shielding layer that does not affect an operation of a geo-magnetic sensor in a pointing input device of a touch screen type using an electromagnetic pen is provided. A magnetic field shielding layer is composed of magnetic metal powder. The magnetic field shielding layer is formed directly on the pointing input device without a need for a separate adhesive layer.
1. An input device comprising:
a display unit for outputting a display screen;
an electromagnetic sensing unit disposed under the display unit to sense a magnetic field generated by an electromagnetic pen upon approaching or contacting a top surface of the display unit;
a magnetic field partial shielding layer disposed under the electromagnetic sensing unit, in which magnetic powder is scattered; and
a geo-magnetic sensor for sensing Earth's magnetic field passing through the magnetic field partial shielding layer.
2. The input device of claim 1 , wherein the magnetic field partial shielding layer is formed by mixing and spreading the magnetic powder and an adhesive.
3. The input device of claim 1 , wherein the magnetic field partial shielding layer has a density with a permeability of 100-200 μ0 in a Direct Current (DC) band.
4. The input device of claim 1 , wherein the magnetic field partial shielding layer has a thickness of 50 μm or more, which varies with a permeability of the magnetic field partial shielding layer.
5. The input device of claim 1 , wherein the magnetic powder is magnetic metal powder selected from a group consisting of ferrite, MolyPermalloy Powder (MPP), an Fe—Si—Al-based material, and an Ni—Fe-based material.
6. The input device of claim 5 , wherein the magnetic field partial shielding layer is formed by mixing the magnetic metal powder and amorphous metal powder with an adhesive.
7. The input device of claim 1 , wherein the magnetic field partial shielding layer is formed by being spread onto a surface of the electromagnetic sensing unit.
8. The input device of claim 1 , further comprising a Printed Circuit Board (PCB) unit disposed under the magnetic field partial shielding layer, on which the geo-magnetic sensor is disposed.
9. The input device of claim 8 , further comprising a shielding layer using an amorphous metal thin film under the magnetic field partial shielding layer and in proximity to a magnetic part when the magnetic part is disposed on or on a side of the PCB unit.
10. The input device of claim 9 , wherein the magnetic field partial shielding layer is formed by being spread onto a surface of the electromagnetic sensing unit, and the shielding layer using the amorphous metal thin film is disposed on a portion of the magnetic field partial shielding layer.
11. The input device of claim 9 , wherein the magnetic part comprises at least one of a speaker and a camera.
12. The input device of claim 1 , wherein the magnetic field partial shielding layer comprises:
a magnetic powder shielding layer on which magnetic powder for transmitting a part of the Earth's magnetic field is scattered; and
an amorphous metal shielding layer using an amorphous metal thin film for blocking the magnetic field.
13. The input device of claim 12 , wherein a position of the magnetic powder shielding layer and the shielding layer using the amorphous metal thin film differs according to a position of the geo-magnetic sensor.
14. The input device of claim 12 , wherein the magnetic powder shielding layer is disposed around the geo-magnetic sensor, and the shielding layer using the amorphous metal thin film is disposed in a region other than a region where the magnetic powder shielding layer is disposed.