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US 2002/0109461 A1Published application
Cathode ray tube device that reduces magnetic field leakage
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsYukio Uchida, Tomoaki Iwamoto, Katsuyo Iwasaki
Life of this patent
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Abstract
Two closed-loop coils are respectively set at the top or the bottom of a cathode ray tube. These two closed-loop coils serves in a pair as a cancel coil. Each closed-loop coil is positioned so as to make an interlinkage with the magnetic field leakage that escapes from the deflection yoke, a part of the closed-loop coil running almost in parallel to the top or bottom edge of an effective display region of a front panel.
Claims13
A cathode ray tube device comprising:
- a cathode ray tube that has a front panel and a funnel;
- an electron gun that is set inside a neck of the funnel and projects electron beams onto an inner surface of the front panel;
- a deflection yoke that is set on the funnel at the neck and deflects the electron beams projected by the electron gun;
- and
- a cancel coil that has at least one closed-loop coil, makes an interlinkage with a magnetic field leakage that escapes from the deflection yoke, and generates a magnetic field in a direction so as to cancel the magnetic field leakage,
- wherein each closed-loop coil is set at either a first position or a second position, the first position being at a top of the cathode ray tube with a part of the closed-loop coil running along a top edge of an effective display region of the front panel, and the second position being at a bottom of the cathode ray tube with a part of the closed-loop coil running along a bottom edge of the effective display region.
3 more elements
A cathode ray tube device comprising:
- a cathode ray tube that has a front panel and a funnel;
- an electron gun that is set inside a neck of the funnel and projects electron beams onto an inner surface of the front panel;
- a deflection yoke that includes a horizontal deflection coil, and is set on the funnel at the neck and deflects the electron beams projected by the electron gun;
- a first coil through which a current passes, the current varying in synchronization with variations in a deflection current passing through the horizontal deflection coil;
- and
- a second coil that has at least one closed-loop coil, makes an interlinkage with a magnetic field leakage escapes from the deflection yoke, and generates a magnetic field in a direction so as to cancel the magnetic field leakage,
- wherein a part of each closed-loop coil is magnetically coupled to the first coil so that an electromotive force is produced for causing a magnetic field in the same direction as the magnetic field generated through the interlinkage with the magnetic field leakage, whereby the magnetic field leakage is further canceled.
4 more elements
Dependencies are inferred from the claim text.