Centering magnet for deflection yokes and process for producing same

• US 6,545,578 B2
• Filed: 08/29/2001
• Issued: 04/08/2003
• Est. Priority Date: 09/01/2000
• Status: Expired due to Fees

• Current Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation), Sanyo Electronic Components Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation), Sanyo Electronic Components Company Limited (Panasonic Holdings Corporation)
• Inventors: Yoshiyama, Shinji
• Primary Examiner(s): Barrera, Ramon M.
• Application Number:
  US09/940,458
• Publication Number:
  US 20020030571A1
• Time in Patent Office: 587 Days
• Field of Search: 335/210-214, 335/284, 335/302-306, 264/429, 264/478, 264/108, 264/328.1, 264/328.2, 264/328.3, 264/328.8
• US Class Current: 335/212
• CPC Class Codes: B82Y 15/00 Nanotechnology for interacting, sensing or actuating, e.g. quantum dots as markers in protein assays or molecular motors
• CPC Class Codes: H01F 7/0278 for generating uniform fields, focusing, deflecting electrically charged particles for magnetic separation by Lorentz force B03C1/023; specially adapted for NMR applications G01R33/383
• CPC Class Codes: H01J 29/701 Systems for correcting deviation or convergence of a plurality of beams by means of magnetic fields at least

Abstract

The invention provides a deflection yoke having two centering magnets mounted thereon for the adjustment of centering. Each of the centering magnets is molded in an annular form from a resin material containing a finely divided magnetic material, the centering magnet having two portions opposed to each other as displaced from each other by 180 degrees about a center axis of the annular form thereof and magnetized to an N pole and an S pole respectively, the content of the magnetic material varying circumferentially of the annular form, the distribution of the content being symmetrical about a straight line orthogonal to a straight line through a center point of the N pole and a center point of the S pole. The magnetic force for the adjustment of centering can be eliminated by the two magnets mounted in combination.

Claims

1. A centering magnet mountable on a deflection yoke for the adjustment of centering and molded in an annular form from a resin material containing a finely divided magnetic material, the centering magnet having two portions opposed to each other as displaced from each other by 180 degrees about a center axis of the annular form thereof and magnetized to an N pole and an S pole respectively, the content of the magnetic material varying circumferentially of the annular form, the distribution of the content being symmetrical about a straight line orthogonal to a straight line through a center point of the N pole and a center point of the S pole.

2. A deflection yoke provided with a pair of centering magnets for the adjustment of centering, each of the centering magnets being molded in an annular form from a resin material containing a finely divided magnetic material, the centering magnet having two portions opposed to each other as displaced from each other by 180 degrees about a center axis of the annular form thereof and magnetized to an N pole and an S pole respectively, the content of the magnetic material varying circumferentially of the annular form, the distribution of the content being symmetrical about a straight line orthogonal to a straight line through a center point of the N pole and a center point of the S pole.

3. A centering magnet mountable on a deflection yoke for the adjustment of centering, the centering magnet being molded in an annular form from a resin material containing a finely divided magnetic material, with a plurality of positions arranged symmetrical about a diametrical line of the annular form and each serving as the most upstream position for a flow of the resin material for molding, the centering magnet being magnetized to an N pole and an S pole respectively at two portions intersecting the diametrical line or at two portions 90 degrees out of phase with said two portions respectively.

4. A centering magnet according to claim 3 wherein the finely divided magnetic material contains an alnico magnetic material.

5. A deflection yoke provided with a pair of centering magnets for the adjustment of centering, each of the centering magnets being molded in an annular form from a resin material containing a finely divided magnetic material, with a plurality of positions arranged symmetrical about a diametrical line of the annular form and each serving as the most upstream position for a flow of the resin material for molding, the centering magnet being magnetized to an N pole and an S pole respectively at two portions intersecting the diametrical line or at two portions 90 degrees out of phase with said two portions respectively.

6. A process for producing a centering magnet mountable on a deflection yoke for the adjustment of centering, the process having the resin molding step of molding an annular magnetic body from a resin material containing a resin powder, and the magnetizing step of magnetizing the magnetic body molded by said step, the resin molding step comprising preparing a mold having a plurality of resin gate openings in corresponding relation with a plurality of positions symmetrical about a diametrical line of the annular form of the magnetic body to be molded, and pouring the resin material containing a finely divided magnetic material into the mold through the resin gate openings, the magnetizing step comprising magnetizing the magnetic body molded by the resin molding step to an N pole and an S pole respectively at two portions thereof intersecting the diametrical line or at two portions thereof 90 degrees out of phase with said two portions respectively.