Kabushiki Kaisha Toshiba

Tadahiro Kojima

Masahiro Yokota

Eiji Kamohara

Takashi Murai

Yuuichi Sano

Masatsugu Inoue

Yoshiaki Ito

Tohru Takahashi

Nobuhiko Akoh

Masaru Ogawa

Shuuji Makimoto

Sadami Sekiguchi

A deflection yoke on a yoke mounting portion with a truncated pyramid shape has a pair of saddle-type horizontal deflecting coils that is located symmetrically with a central axis and has a truncated pyramid shape. A core with a truncated cone shape is coaxially located on the outer periphery of the horizontal deflecting coils. A pair of vertical deflecting coils are toroidally wound around the core. If the positions of a horizontal axis and a vertical axis are given by 0&#xb0; and 90&#xb0;, respectively, in the circumference direction around the central axis, the winding of one vertical deflecting coil has a starting point on the horizontal-axis side within the range of 5&#xb0;-30&#xb0; and is distributed from the starting point to 90&#xb0; and wound symmetrically with the vertical axis. The windings of the vertical deflecting coils are wound symmetrically with the horizontal axis.

Deflection yoke and cathode ray tube apparatus provided with the same

A deflection yoke of a cathode ray tube apparatus comprises a pair of saddle-type horizontal deflection coils located symmetrically with respect to a central axis and substantially in the shape of a truncated pyramid. A magnetic core substantially in the shape of a truncated cone is located coaxially around the horizontal deflection coils, and a pair of vertical deflection coils are wound on the magnetic core. A relation between a space vf between a large-diameter end portion of the magnetic core and each of the horizontal deflection coils and a space vr between a small-diameter end portion of the magnetic core and each of the horizontal deflection coils, with respect to the direction of a vertical axis perpendicular to the central axis, is given by vf&gE;vr.

In a semi-toroidal deflection yoke, a middle point CL(M) of an entire length along a tube axis from a large-diameter portion to a small-diameter portion of a magnetic core lies on a small-diameter portion side of a horizontal deflection coil relative to a point lying at a distance of 0.41&times;HL along the tube axis from a large-diameter portion of the horizontal deflection coil, where HL is an entire length of the horizontal deflection coil along the tube axis. The deflection yoke deflects electron beams efficiently, reducing the deflection electric power the deflection yoke requires. A cathode ray tube provided with the deflection yoke can suppress pincushion type distortion which may occur in the vertical direction of a screen, and can therefore display images of satisfactory quality.

Deflection yoke and cathode-ray tube apparatus with the same

A vacuum envelope of a cathode ray tube includes a face panel having a phosphor screen formed on the inner surface, a funnel joined to the face panel and having a yoke-mounting section, and an electron gun for emitting electron beams toward the phosphor screen. A deflection yoke mounted on the yoke-mounting section of the funnel has a first open end portion positioned on the side of the phosphor screen, and a correcting coil for correcting the positional deviation of the displayed image in a rotating direction is arranged at the first open end portion. The correcting coil is formed substantially rectangular to conform with the cross sectional shape of each of the yoke-mounting section and deflection coils of the deflection yoke.

Deflection device for a cathode ray tube having a correction coil with a non-circular shape

A cathode ray tube includes a vacuum envelope having a substantially rectangular panel, a cylindrical neck, and a funnel connecting the panel and the neck. A phosphor screen arranged on the inner surface of the panel generates luminescence upon impingement of electron beams, which are generated by an electron gun assembly disposed in the neck. In order to create a image visible through the panel, a deflection yoke is mounted on the outer surface of the funnel to generate a magnetic field in the funnel, deflect the electron beams, and thereby scan the phosphor screen. According to the present invention, the portion of the funnel over which the deflection yoke is mounted is formed such that the power required to generate a deflection field capable of scanning substantially the entire phosphor screen may be reduced. To this end, the funnel is formed over a predetermined range along a first axis coincident with the axis of symmetry of the cylindrical neck such that at least one cross section of the inner and outer funnel perpendicular to the first axis has a non-circular shape and a maximum diameter along a direction other than those of the major and minor axes of the substantially rectangular panel. Moreover, within this predetermined range, the point on the funnel's cross section that is furthest from the first axis is not located along the direction of the panel's diagonal axis.

Cathode ray tube having an envelope shaped to reduce beam deflection

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.

Cathode ray tube

This cathode ray tube includes a vacuum envelope having a substantially rectangular panel, a funnel formed contiguous to the panel, and a cylindrical neck formed contiguous to the small-diameter end portion of the funnel, an electron gun assembly disposed in the neck to generate electron beams, and a deflection yoke mounted on the outer side of the funnel near the neck side over a predetermined range to form a magnetic field in the funnel, thereby deflecting the electron beams along the major and minor axes of the panel. Of the predetermined range of the funnel, at the neck side, the funnel is formed to have an outer shape with a section which is gradually deformed, from the neck side to the panel side, from a circular shape to a non-circular shape having a maximum diameter along a direction other than the major and minor axes. The funnel of the predetermined range is formed to have an outer shape with a section that satisfies a relation:

A color cathode-ray tube comprises a mask unit arranged between a face panel and an electron gun. The mask unit comprises a shadow mask and a mask frame supporting the shadow mask with being applied with tension. The shadow mask is formed of a substantially rectangular thin plate, arranged to face a phosphor screen formed on an inner surface of the face panel, and has a number of electron beam apertures through which electron beams emitted from the electron gun pass. The mask frame comprises a substantially rectangular frame body which has a pair of first sidewalls facing each other and a pair of second sidewalls facing each other, and a pair of mask fixing sections secured to a pair of opposite side edge portions of the shadow mask and extending along the side edge portions. The pair of mask fixing sections extend substantially in parallel with the first sidewalls, respectively and have connecting sections each of which connects a middle portion of the mask fixing section to a middle portion of the corresponding first sidewall.

Growing community of inventors

Kumagaya, Japan

Tadahiro Kojima