Method for correcting the effect of terrestrial magnetism on electron beam tracking
AssigneeSony Corporation
InventorMasaru Nagashima
Life of this patent
Estimating the term…
Abstract
A method and apparatus for correcting the tracking of an electron beam which includes the steps of generating a supplemental magnetic field, generating a reverse magnetic field and removing the correcting magnetic field. The direction of the supplemental magnetic field is substantially the same as the direction of a terrestrial magnetism. The reverse magnetic field substantially offsets the terrestrial magnetism.
Claims12
A method for correcting the tracking of an electron beam comprising the steps of:
- generating a supplemental magnetic field having a direction which is substantially the same as the direction of a terrestrial magnetism;
- generating a reverse magnetic field, which has a magnitude and direction which is sufficient to substantially offset said terrestrial magnetism;
- removing said supplemental magnetic field;
- and
- generating an electron beam for illuminating a desired target on a CRT display.
A method for correcting the tracking of an electron beam to offset the effect of terrestrial magnetism in a cathode ray tube comprising the steps of:
- generating a supplemental magnetic field by flowing a certain DC electric current to a supplemental coil, a direction of said supplemental magnetic field being substantially the same as the direction of a terrestrial magnetism;
- generating an alternating attenuated magnetic field by flowing an alternating attenuated electric current to a demagnetization coil;
- generating a reverse magnetic field relating said terrestrial magnetism and said supplemental magnetic field, said reverse magnetic field magnetizing a magnetic material part on said cathode ray tube and substantially offsetting said terrestrial magnetism;
- and
- removing said correcting magnetic field.
A method of correcting the tracking of an electron beam in a cathode ray tube, so as to substantially offset the effects of terrestrial magnetism, said method comprising the steps of:
- generating a supplemental magnetic field which has a direction which is substantially equal to the direction of the terrestrial magnetism;
- generating a reverse magnetic field which has a magnitude and a direction substantially opposite to the magnitude and direction of said terrestrial magnetism;
- removing said correcting magnetic field;
- and
- generating an electron beam for illuminating a desired target on a CRT display.
An apparatus for correcting the affect of terrestrial magnetism on the tracking of an electron beam in a cathode ray tube comprising:
- a supplemental coil for generating a supplemental magnetic field;
- said supplemental magnetic field having a direction which is substantially equal to the direction of said terrestrial magnetism;
- a demagnetization coil for generating an alternating attenuated magnetic field;
- a magnetic assembly mounted on said cathode ray tube for generating a reverse magnetic field having magnitude and direction which is substantially equal and opposite to said terrestrial magnetism;
- said magnetic assembly is magnetized by said reverse magnetic field;
- and
- means for generating an electron beam for illuminating a desired target on said cathode ray tube.
An apparatus for correcting the affect of terrestrial magnetism on the tracking of an electron beam in a cathode ray tube comprising:
- a supplemental coil for generating a supplemental magnetic field;
- said supplemental magnetic field having a direction which is substantially equal to the direction of a terrestrial magnetism;
- a demagnetization coil for generating an alternating attenuated magnetic field;
- a magnetic assembly mounted on said cathode ray tube for generating a reverse magnetic field having substantially equal and opposite magnitude and direction of said terrestrial magnetism;
- said magnetic assembly is magnetized by said reverse magnetic field;
- means for generating an electron beam for illuminating a desired target on said cathode ray tube;
- and
- said supplemental magnetic field is perpendicular to the direction of said alternating attenuated magnetic field.
Dependencies are inferred from the claim text.