Hitachi, Ltd.

Hitachi Mizusawa Electronics Co.

Masaki Nakahara

Nobutaka Okuyama

Michitaka Ohsawa

Soichi Sakurai

Takahisa Mizuta

Ichiro Niitsu

Souichi Sakurai

Hiroki Oguro

Ichiri Niitsu

A deflection system for a cathode-ray tube including a horizontal deflection core, a magnetic coil, and a vertical deflection coil toroidally wound on the magnetic core. The vertical deflection coil has a plurality of superimposed winding layers arranged with respect to a vertical axis of the deflection system with at least one of the layers of the vertical deflection coil being disposed asymmetrically with respect to the vertical axis or disposed symmetrically with respect to the vertical axis and having winding portions delimiting at least one gap along an extent thereof at a position other than the vertical axis. In this manner, an induced voltage in the at least one of the layers is substantially equal to an induced voltage in each of another of the layers at least in the region of the vertical axis, whereby ringing is substantially prevented.

Deflection system

A system for generating magnetic fields to converge a plurality of electron beams in a cathode-ray tube including at least one convergence yoke having a core with a ring-shaped outer periphery and a plurality of magnetic poles on an inner periphery thereof extending toward a neck part of the cathode-ray tube for forming magnetic paths therewith. A lateral line comma aberration correcting coil arrangement is provided with at least a first coil wound on at least one of the plurality of magnetic poles of the at least one convergence yoke and a first driving circuit connected to the first coil for enabling generation of a magnetic field to correct misconvergence in a lateral line direction on a fluorescent face of the cathode-ray tube, and a longitudinal line correction coil arrangement is provided with at least a second coil wound on the at least one of the plurality of magnetic poles of the at least one convergence yoke and a second driving circuit connected to the at least second coil for enabling generation of a magnetic field to correct misconvergence in a longitudinal line direction on the fluorescent face of the cathode-ray tube.

Convergence system

A convergence system for a cathode-ray tube having three detection magnetic pole pieces are disposed opposing to each other on both sides of a center beam for forming magnetic paths inside the neck part of a cathode-ray tube. A first convergence yoke is disposed outside the neck part of the cathode-ray tube for forming magnetic paths together with the magnetic pole pieces. A first coil is wound on a first convergence yoke to generate a magnetic field for correcting horizontal misconvergence between the center beam and a side beam on a side of the center beam. A second coil is wound on the first convergence yoke to generate a magnetic field for correcting horizontal misconvergence between the center beam and a side beam on the other side of the center beam. A third coil is wound on the first convergence yoke to generate a magnetic field for correcting vertical misconvergence between the center beam and both side beams. Furthermore, a second convergence yoke is disposed on the neck part of the cathode-ray tube at a different position from the first convergence yoke. A fourth coil is wound on the second convergence yoke to generate a magnetic field for correcting vertical misconvergence between both side beams.

System for converging a plurality of electron beams in cathode ray tube

The disclosed relates to a convergence apparatus to be used for a single electron gun type cathode-ray tube, and relates to a convergence yoke to be used for the convergence apparatus. Each of two magnetic poles for generating a bipolar magnetic field is constituted by a first one of a plurality of core protrusions located on a horizontal or vertical axis and at least one pair of second ones of the plurality of core protrusions located at positions equiangularly and symmetrically deviated from the horizontal or vertical axis, and a ratio of an ampere turn of the coil wound on each of at least one pair of second core protrusions to an ampere turn of the coil wound on the first core protrusion is suitably changed. A firt magnetic auxiliary plate and a second magnetic auxiliary plate are provided on a first core protrusion constituting each of a first pair of magnetic poles and on a second core protrusion constituting each of a second pair of magnetic poles respectively. Each of the first and second magnetic auxiliary plates has a fork end projected along an axis perpendicular to a horizontal axis as well as a vertical axis. The first and second magnetic auxiliary plates have respective widths existing within an angular range symmetrically deviated by 45.degree. from the horizontal axis and within an angular range symmetrically deviated by 45.degree. from the vertical axis respectively. Each of the first and second magnetic auxiliary plates has a substantially Y-shaped and axisymmetrical form.

Growing community of inventors

Chigasaki, Japan

Masaki Nakahara