Kabushiki Kaisha Toshiba

Takashi Murai

Masatsugu Inoue

Shinichiro Nakagawa

Yoshiaki Ito

Norio Shimizu

Tadahiro Kojima

Munechika Tani

Ichiro Saotome

Kumio Fukuda

Nobuhiko Akoh

Takeshi Fujiwara

Kiyoshi Tokita

Tohru Takahashi

Shinji Ohama

Takeshi Nakayama

Masaru Ogawa

Shigeru Tsuchida

Satoshi Tsunokawa

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

Color cathode ray tube having a radius of curvature ratio relationship

A shadow mask includes a substantially rectangular effective region formed having a number of electron beam passage apertures and opposed to a phosphor screen and a substantially rectangular skirt portion provided around the effective region and extending in the direction of a tube axis. The skirt portion has a pair of long sides extending substantially parallel to a major axis and a pair of short sides extending substantially parallel to a minor axis, the long and short sides being welded to the inner surface of a substantially rectangular mask frame. A distance a from an extending end of the skirt portion on each long side to the weld spot is longer than a distance b from an extending end of the skirt portion on each short side to the weld spot.

Color cathode ray tube

A color picture tube includes a panel of which substantially rectangular effective area has a flat external surface and a curved internal surface, and on the internal surface of the effective area thereof a phosphor screen is formed. The internal surface of the effective area of the panel, when an average radius of curvature in major axis direction is RH, an average radius of curvature in minor axis direction is RV, an average radius of curvature in long side direction is RL and an average radius of curvature in short side direction is RS, is formed in a curved face satisfying RH>RV and RS&gE;RV, or RH>RV and RS&gE;RV and RL&gE;RH. In this color picture tube, flatness of the effective area of the panel and visibility are improved.

Color picture tube

A skirt portion of a mask body includes cut portions. The width of the cut portions along the minor or major axis ranges from 0.10&times;L to 0.45&times;L, where L is the distance from an end of the minor or major axis to a diagonal end, and the height of the cut portions along the tube axis is equal to 5% to 40% of the height of the skirt portion along the tube axis in a region near the minor or major axis.

Color cathode ray tube having color sorting mask including cut portions

A main body of a shadow mask is opposed to a phosphor screen and is formed in a substantially rectangular shape. The main body has a main surface portion where a number of electron beam apertures are formed, and a skirt portion provided around the main surface portion with a non-aperture portion interposed between the skirt portion and the main surface portion. A plurality of rectangular openings extending in the long axis direction (or X-direction) of the mask body are formed at the skirt portion. Concave portions extending in the long axis direction (X-direction) of the mask body are formed at the non-aperture portion. The openings and concave portions are provided within a range of about &frac14; of the length W of the mask body in the long axis direction, with respect to a center of the range defined at a position distant from the short axis Y by about &frac13; of the length W of the long axis direction of the mask body.

Color cathode ray tube for reducing landing drift of electron beams on phosphor layers

A substantially rectangular shadow mask is arranged opposite to a phosphor screen formed on an inner surface of a panel. The shadow mask has a mask body and a mask frame to which a peripheral portion of the mask body is attached. The shadow mask has a rectangular form having a center through which a tube axis passes, and a long axis and a short axis passing through the center and perpendicular to each other. The mask frame has a pair of long side walls extending parallel to the long axis and a pair of short side walls extending parallel to the short axis. The height of each long side wall at a central portion along the tube axis is lower than the height of each short side wall at a central portion along the tube axis.

A shadow mask is provided in an envelope of a color cathode ray tube. The shadow mask includes a mask body having a number of electron beam apertures, and a mask frame having side walls equipped on the peripheral portion of the mask body. The side walls of the mask frame includes a pair of long side walls extending in parallel with the long axis X and a pair of short side walls extending in parallel with the short axis Y. Beads and are respectively formed on the long side walls and the short side walls. The length of each bead of the long side wall along the long axis is set in a range of 55% to 80% of the length of the long side walls along the long axis, and a width of the bead in the tube axis direction is set in a rage of 40% to 75% of the maximum width of the long side walls in the tube axis direction. The length of each bead of the short side wall along the short axis is set in a range of 55% to 80% of the length of the short side walls along the short axis, and a width of the bead in the tube axis direction is set in a rage of 40% to 75% of the maximum width of the short side walls in the tube axis direction.

Color cathode ray tube with shadow mask having mask frame balanced in mechanical strength

Color cathode ray tube having shadow mask with prescribed bridge widths

A color cathode ray tube has a substantially rectangular shadow mask in which a plurality of slit type aperture arrays are aligned in the direction of the major axis of an effective region defined by a curved surface opposing a phosphor screen formed on the inner surface, defined by a concave curved surface, of the effective region of a panel. Each slit type aperture array is obtained by arranging a plurality of slit type apertures in an array in the direction of the minor axis of the effective region of the shadow mask. In this color cathode ray tube, the difference between the array interval of the slit type aperture arrays at a peripheral portion on the long side of the shadow mask and the array interval of the slit type aperture arrays on the major axis is a maximum value within a distance range of 0.4 h to 0.9 h (h is 1/2 the length of the effective region of the shadow mask in the direction of the major axis) from the minor axis, and the array interval of the slit type aperture arrays at the end of the major axis is larger than that of the slit type aperture arrays at a corner. Thus, local doming of the shadow mask can be suppressed.

Color cathode ray tube with suppressed doming

A color-cathode ray tube having a shadow mask with improved aperture arrays. The aperture arrays are spaced at appropriate intervals and are curved to suppress local doming of the effective part of the shadow mask and to prevent electron-beam mislanding from occurring on a phosphor screen. The distance between any two adjacent apertures is expressed as: PH(N)=A+BN.sup.2 +CN.sup.4, where PH(N) is the distance between the (N-1)th and Nth arrays and A, B, and C are fourth-degree functions of a Y-coordinate. The apertures along a long side of the effective part of the shadow mask in a section extending for one-fourth of a width of the effective part of the shadow mask from a short side of the effective part of the shadow mask are inclined in an opposite direction to the apertures within the section and located one-third of a height of the effective part of the shadow mask from the long side.

Growing community of inventors

Fukaya, Japan

Takashi Murai