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US 5,929,559 AGranted
Cathode ray tube
AssigneeKabushiki Kaisha Toshiba
InventorsYuuichi Sano, Masahiro Yokota, Tadahiro Kojima, Eiji Kamohara
Life of this patent
Estimating the term…
Abstract
A funnel of a cathode ray tube includes a yoke attachment portion on which a deflection yoke is mounted so as to deflect the electron beam emitted from an electron gun along horizontal and vertical axis. At least one cross section of the yoke attachment portion, perpendicular to the tube axis, has an inner contour which is substantially rectangular with four sides. The sides are defined by convexities curved toward the tube axis and each having a peak on the horizontal or vertical axis. The inner contour of the cross section faces the electron beam passage region with a substantially constant gap.
Claims6
A cathode ray tube comprising:
- a vacuum envelope having a face panel including a substantially rectangular effective portion having horizontal and vertical axes which cross at right angles and pass a tube axis, a funnel connected to the face panel, a cylindrical neck connected to a smaller-diameter end of the funnel, and a phosphor screen formed on an inner surface of the effective portion of the face panel, the funnel including a yoke attachment portion extending from the smaller-diameter end connected to the neck toward the face panel;
- an electron gun arranged within the neck, for emitting an electron beam to the phosphor screen;
- and
- a deflection yoke mounted on outer surfaces of the neck and the yoke attachment portion of the funnel, for deflecting the electron beam emitted from the electron gun along the horizontal and vertical axes so to cause the electron beam to scan the phosphor screen;
- at least one cross section of the yoke attachment portion, perpendicular to the tube axis, having a non-circular outer contour which has four line segments divided by the horizontal and vertical axes and, in each of the four line segments, a distance between the tube axis and the outer contour is maximal at a point between a first intersection of the horizontal axis and the outer contour and a second intersection of the vertical axis and the outer contour;
- and
- on the at least one cross section, assuming that an intersection of the inner contour of the cross section and a line passing through the tube axis and forming an angle (.theta.) with the horizontal axis is represented by Pi(.theta.), as shortest distance between Pi(.theta.) and the horizontal axis is represented by Piv(.theta.) and a shortest distance between Pi(.theta.) and the vertical axis is represented by Pih(.theta.), the inner contour of the cross section has a shape such that Pih(.theta.) is expressed by a function which has a minimal value substantially at an angle .theta.=0.degree.,when the angle (.theta.) is varied in a range of -90.degree.<0<90.degree., or Piv(.theta.) is expressed by a function which has a minimal value substantially at an angle .theta.=90.degree.. when the angle (.theta.) is varied in a range of 0.degree.<.theta.<180.degree..
4 more elements
A cathode ray tube comprising:
- a vacuum envelope having a face panel including a substantially rectangular effective portion having horizontal and vertical axes which cross at right angles and pass a tube axis, a funnel connected to the face panel, a cylindrical neck connected to a smaller-diameter end of the funnel, and a phosphor screen formed on an inner surface of the effective portion of the face panel, the funnel including a yoke attachment portion extending from the smaller-diameter end connected to the neck toward the face panel;
- an electron gun arranged within the neck, for emitting an electron beam to the phosphor screen;
- and
- a deflection yoke mounted on outer surfaces of the neck and the yoke attachment portion of the funnel, for deflecting the electron beam emitted from the electron gun along the horizontal and vertical axes so as cause the electron bean to scan the phosphor screen;
- at least one cross section of the yoke attachment portion, perpendicular to the tube axis, having a substantially rectangular outer contour which includes a pair of first opposed sides that traverse the horizontal axis, and a pair of second opposed sides that traverse the vertical axis, and a substantially rectangular inner contour which includes a pair of third opposed sides that traverse the horizontal axis, and a pair of fourth opposed sides that traverse the vertical axis;
- and
- at least a part of each of the third and fourth sides of the inner contour being defined by a convexity curved toward the tube axis.
4 more elements
Dependencies are inferred from the claim text.