Apparatus and method for demagnetizing shadow mask

• US 20070296324A1
• Filed: 06/22/2007
• Published: 12/27/2007
• Est. Priority Date: 06/22/2006
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Philips LCD Company Limited (LG Display Co., Ltd.)
• Inventors: Yoo, Choong-Keun, Lee, Kang-Ju
• Granted Patent: US 7,710,706 B2
• Time in Patent Office: Days
• US Class Current: 313/402
• CPC Class Codes: C23C 14/042 using masks
• CPC Class Codes: H01J 9/142 of shadow-masks for colour television tubes

Abstract

An apparatus for demagnetizing a shadow mask includes a shadow mask stocker, a cassette in the shadow mask stocker, wherein at least one shadow mask is disposed in the cassette, and a demagnetizing means that generates a magnetic field by an alternating current (AC), thereby removing magnetism of the at least one shadow mask.

Claims

1. An apparatus for demagnetizing a shadow mask, the apparatus comprising:

a shadow mask stocker;

a cassette in the shadow mask stocker, wherein at least one shadow mask is disposed in the cassette; and

a demagnetizing means that generates a magnetic field by an alternating current (AC), thereby removing magnetism of the at least one shadow mask.

2. The apparatus according to claim 1, wherein the demagnetizing means includes a coil and an AC power source connected to the coil.

3. The apparatus according to claim 2, wherein the coil is tubularly disposed around the at least one shadow mask and the AC power source applies the AC to the coil.

4. The apparatus according to claim 1, wherein the demagnetizing means includes two coils and an AC power source connected to the coils.

5. The apparatus according to claim 4, wherein the coils are ring-shaped and respectively disposed at opposite sides of the cassette substantially in parallel such that the at least one shadow mask is disposed between the coils.

6. The apparatus according to claim 5, wherein a distance between the coils substantially equals to a radius of the coils.

7. The apparatus according to claim 4, wherein currents through the coils flow along a same direction.

8. The apparatus according to claim 1, wherein the cassette is formed of a non-magnetized material.

9. A method of demagnetizing a shadow mask, the method comprising:

disposing at least one shadow mask in a shadow mask stocker having a demagnetizing means therein;

applying an alternating current (AC) to the demagnetizing means, thereby generating a magnetic field; and

removing magnetism of the at least one shadow mask by the magnetic field.

10. The method according to claim 9, wherein the demagnetizing means includes one of a solenoid and a Helmholtz coil.

11. The method according to claim 9, wherein applying the AC to the demagnetizing means includes decreasing the AC.

12. A method for fabricating an electronic device using a shadow mask, the method comprising:

demagnetizing the shadow mask, the demagnetizing the shadow mask step comprising disposing at least one shadow mask in a shadow mask stocker having a demagnetizing means therein, applying an alternating current (AC) to the demagnetizing means, thereby generating a magnetic field, and removing magnetism of the at least one shadow mask by the magnetic field.

13. The method according to claim 12, wherein the demagnetizing means includes one of a solenoid and a Helmholtz coil.

14. The method according to claim 12, wherein applying the AC to the demagnetizing means includes decreasing the AC.