JPH1125880A - Color cathode-ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of unwanted electron beams from barium oxide attached to a control electrode or an accelerating electrode. SOLUTION: A cathode structure body comprising a plurality of cylindrical cathodes 7 for radiating a plurality of electron beams, arranged laterally in a single row, a control electrode 32 having a plurality of electron beam-passing through-holes 32R, 32G, 32B facing the cylindrical cathodes 7 so as to correspond to the cylindrical cathodes 7 at least laterally in one row, and a plurality of electrodes containing an accelerating electrode 33, a focusing electrode, and an anode arranged in order on a fluorescent screen side from the control electrode 32 side are embedded in an insulating supporting rod, and fixed at the constant intervals in the tube axial direction to obtain an electron gun. At least the control electrode 32 and the accelerating electrode 33 are formed with a Ni-Fe alloy, which contains a very small amount of Ti.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color cathode ray tube such as a color picture tube or a color display tube, and more particularly to an electrode assembly having improved electron emission rising characteristics and static convergence characteristics at the initial stage of power-on. The present invention relates to a color cathode ray tube having an electron gun.

[0002]

2. Description of the Related Art A color cathode ray tube such as a color picture tube or a display tube is widely used as a monitor for television broadcast reception or information processing equipment because of its fine image reproducibility.

A color cathode ray tube of this type contains a funnel having a face plate having a phosphor screen formed on an inner surface thereof, and an electron gun assembly connected to the funnel and emitting an electron beam toward the phosphor screen. A vacuum envelope having at least a neck.

FIG. 3 is a schematic cross-sectional view illustrating the configuration of a shadow mask type color cathode ray tube as an example of a color cathode ray tube to which the present invention is applied. Reference numeral 20 denotes a face plate, 21 denotes a neck, and 22 denotes a face plate. A funnel 23 connected to the neck; a phosphor screen 23 formed on the inner surface of the face plate to form a video display surface;
4 is a shadow mask as a color selection electrode, 25 is a mask frame that holds the shadow mask and forms a shadow mask structure, 26 is an inner shield that shields external magnetism, and 27 is the shadow mask structure planted on the inner wall of the face plate. A suspension spring mechanism for suspending and supporting a standing stud, 28 is housed in a neck and accommodates three electron beams Bs
(× 2), an electron gun that emits Bc horizontally (inline), 29 is a deflecting device that deflects the electron beam horizontally and vertically, and 30 is a magnetic device that performs color purity and centering correction.

In the configuration shown in FIG.
0, a neck 21 and a funnel 22 constitute a vacuum envelope, and deflect the two electron beams Bc and Bs (× 2) emitted from the electron gun 28 in a horizontal line (inline).
The phosphor screen 23 is two-dimensionally scanned by being deflected in two directions, horizontal and vertical, by the deflection magnetic field formed in 9. Note that Bc indicates a center beam and Bs indicates a side beam.

The three electron beams Bs and Bc (× 2) are red (side beam Bs) and green (center beam Bs), respectively.
c) modulated by color signals of blue (side beam Bs), red, green, and red constituting the phosphor screen 23 by receiving a color selection through a beam passage hole of a shadow mask 24 disposed immediately before the phosphor screen 23; A desired color image is reproduced by projecting on each of the three blue phosphor mosaics.

FIG. 4 is a side view of an essential part for explaining an example of a structure of an electron gun structure used for a color cathode ray tube. Reference numeral 31 denotes a cathode structure arranged in line, 32 denotes a first electrode serving as a control electrode, 33 is a second electrode which is an accelerating electrode, 34 is a third electrode
Electrode, 35 is a fourth electrode, 36 is split electrodes 361 and 362
A fifth electrode (focusing electrode), 37 is an anode, 38 is a shield cup fixed to the anode, 39 is an insulating support (also referred to as multi-form glass or beading glass), and 40 is an electron gun surrounding the vacuum. Reference numeral 41 denotes a stem pin for supplying a required signal and voltage to each electrode of the electron gun.

A control electrode 32 having a built-in cathode structure 31;
The accelerating electrode 33 and the other electrodes 34 to 37 are buried and fixed to the insulating support 39 at predetermined intervals. Each electrode is supplied with a required signal and voltage from an external circuit via a stem pin 41. The highest voltage is applied to the anode 37 from an anode terminal (not shown) provided on the wall surface of the funnel through an internal conductive film (not shown).

In this type of electron gun, the control electrode 32 is a cup-shaped electrode, in which the cathode structure 31 is housed and fixed. In addition, the control electrode is formed of a plate-shaped electrode.
There is also an electron gun of a type in which the cathode structure is also independently embedded and fixed in the insulating support 39. The present invention is applicable to any of the above types of electron guns.

In the cathode assembly 31, an oxide cathode generally uses an oxide of barium Ba, strontium Sr, and calcium Ca as an electron source, and an impregnated cathode in which tungsten W is used as a base metal. An oxide is used.

FIG. 5 is a cross-sectional view in the in-line direction illustrating an example of the structure of the cathode structure of the above-mentioned electron gun, wherein 1 is an electron emission surface, 2 is a cap-shaped base metal, 3 is a sleeve, and 4 is a sleeve. A metal sleeve support supporting the lower end, 5 is a metal cathode support having the lower end of the sleeve fixed inside, 6 is a side opposite to the portion where the cylindrical cathode is fixed by penetrating the cathode support. An insulating substrate, which is held at a predetermined interval at one end, is a cylindrical cathode.

A heater is housed inside each cylindrical cathode, but is not shown in the figure.

In FIG. 1, a cylindrical cathode 7 is constituted by an electron emission surface 1, a base metal 2, a sleeve 3, and a sleeve support 4, and the cylindrical cathode 7 is inserted into a cylindrical cathode support 5. And welded to the cathode support in the vicinity of the lower end of the sleeve support, penetrated this through an insulating substrate 6 made of a glass-based material so that the cylindrical cathodes 7 were arranged at predetermined intervals, and fixed by welding. Is configured.

The cathode assembly is fixed together with other electrodes constituting the electron gun to the insulating support rod 39 (see FIG. 4) in a predetermined relationship to assemble an in-line type electron gun.

Japanese Patent Application Laid-Open (JP-A) No. 63-294842 can disclose a prior art relating to this kind of cathode structure.

[0016]

In the manufacturing process of a color cathode ray tube, an activation process is performed at a temperature higher than a normal operating temperature of a cathode ray tube in order to stabilize an electron beam emitted from a cathode assembly in a short time. It is carried out. At this time, since the electron emission surface, which is an electron source, is in a high temperature state, the heat evaporates Ba oxide and adheres to a control electrode and an acceleration electrode which are located near the cathode and opposed to each other.

After the real sphere is completed, Ba oxide adhering to the control electrode and the accelerating electrode becomes an electron source, and an electron beam is extracted regardless of a signal input from the stem pin, causing a problem that the phosphor screen emits light. there were.

An object of the present invention is to solve the above-mentioned problems of the prior art and to provide a color cathode ray tube which prevents generation of unnecessary electron beams from Ba oxide adhered to a control electrode and an acceleration electrode.

[0019]

In order to achieve the above object, according to the present invention, a constituent material of a control electrode or an acceleration electrode close to a cathode contains titanium Ti for preventing a decrease in the work function of Ba.

That is, the present invention provides a cathode structure comprising a plurality of cylindrical cathodes which emit a plurality of electron beams arranged in a horizontal line, and a structure in which the cylindrical cathodes are opposed to the cylindrical cathodes in at least one horizontal line. A control electrode having a plurality of corresponding electron beam passage holes, and a plurality of electrodes including an accelerating electrode, a focusing electrode, and an anode sequentially arranged from the control electrode side to the phosphor screen side are embedded in an insulating support rod to form a tube shaft. In a color cathode-ray tube provided with an electron gun fixed at regular intervals in the direction, at least the control electrode and the accelerating electrode are made of N containing a small amount of Ti.
It is characterized by comprising an i-Fe alloy material.

The Ni-Fe alloy material contains 42% N
i-Fe, and the content of Ti is 0.30 to 0.5.
0%.

Further, the present invention provides a cathode structure comprising a plurality of cylindrical cathodes for emitting a plurality of electron beams arranged in a horizontal row, and at least one horizontal row of the cathode structures opposed to the cylindrical cathode. A control electrode having a plurality of corresponding electron beam passage holes, and a plurality of electrodes including an accelerating electrode, a focusing electrode, and an anode sequentially arranged from the control electrode side to the phosphor screen side are embedded in an insulating support rod to form a tube shaft. In a color cathode ray tube provided with an electron gun fixed at a constant interval in a direction, at least the control electrode and the accelerating electrode are made of Ni—
It is characterized by comprising a Co-Fe alloy material.

The Ni—Co—Fe alloy material is 2
9% Ni-18% Co-Fe, and the Ti content is 0.30 to 0.50%.

Electrodes close to the cathode (control electrode, acceleration electrode, etc.)
The titanium Ti contained in the constituent material of Example 1
Prevent the work function of a from lowering. As a result, generation of an electron beam from the acid Ba attached to the control electrode and the acceleration electrode is suppressed.

The present invention is applicable not only to a color cathode ray tube electron gun having an in-line type electron gun, but also to a monochrome cathode ray tube or a projection type cathode ray tube having a single electron gun for emitting a single electron beam, or to other types. Can be similarly applied to the cathode ray tube.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As described above, in order to prevent the generation of unnecessary electron beams from electrodes near the cathode, such as the first electrode (control electrode) and the second electrode (acceleration electrode), the electrode must It is necessary to prevent the work function of the attached Ba oxide from lowering.

According to the present invention, as a means for increasing the work function of Ba oxide, an oxide of Ti is formed on the surface of a metal material constituting a control electrode or an acceleration electrode, and Ba oxide is deposited thereon. did. Hereinafter, embodiments of the present invention will be described in detail with reference to examples.

FIG. 1 is a sectional view in the in-line direction for explaining an example of the structure of a cathode structure, a control electrode and an acceleration electrode to which the present invention is applied. FIG. 2 is a cross-sectional view taken along the central beam passage hole of FIG. 1 and cut at right angles to the in-line direction.

The control electrode 32 is a cup-shaped electrode having three electron beam passage holes 32B, 32G, and 32R at the bottom, and has three cylindrical cathodes 7 arranged in-line therein.
Are housed to form an integrated structure.

The three cylindrical cathodes 7 are supported by an insulating substrate 6 and a metal fixing member 7a is fixed around the insulating member 6. The fixing member 7a is integrated by welding to the cup-shaped inner wall of the control electrode 32. ing.

The control electrode 32 is fixed by embedding a pair of fixing pieces 32a attached to its outer wall into an insulating support rod 39 of the electron gun.

An accelerating electrode 33 is provided near the fluorescent screen side of the control electrode 32. The accelerating electrode 33 is a plate-like electrode, and the electron beam passage holes 32B formed by the control electrode 32,
Three electron beam passage holes 33 coaxial with 32G and 32R
B, 33G and 33R are formed.

The accelerating electrode 33 is provided with fixing portions 33a protruding at both ends in a direction perpendicular to the in-line direction.
9 and embedded and fixed.

The cathode structure 7 has three cylindrical cathodes 7 arranged and fixed in-line on an insulating substrate 6 and fixed inside a cup-shaped control electrode 32 via a fixing member 7a.

The control electrode 32 and the acceleration electrode 33 shown in FIGS. 1 and 2 are formed by using a Ni--Fe alloy material containing a small amount of Ti.

Specifically, the Ni-Fe alloy material is 42% N
i-Fe, and the content of Ti is 0.30 to 0.50%
It has been experimentally verified that by setting the range, the unnecessary electron beam can be suppressed without deteriorating the static convergence characteristics due to thermal expansion.

Further, as a constituent material of the control electrode and the acceleration electrode, a Ni—Co—Fe alloy material containing a small amount of Ti can be used.

Specifically, 29% Ni-18% Co-Fe is used as the Ni-Co-Fe alloy material, and the content of Ti is set in the range of 0.30 to 0.50%. Similarly, it was experimentally verified that the unnecessary electron beam can be suppressed without deteriorating the static convergence characteristic due to thermal expansion.

In each of the above embodiments, Ni containing Ti is used.
Although the control electrode and the accelerating electrode are composed of an electrode made of a Ni-Co-Fe alloy material containing Ti or a Ti-containing alloy material, the present invention is not limited to these. The above-mentioned alloy materials can also be used.

[0040]

According to the present invention, Ti is easily oxidized as compared with Fe, Ni and the like, and the work function in the attachment of Ba oxide is maintained at a high level. Therefore, when Ti is contained in the first electrode (control electrode) or the second electrode (acceleration electrode) near the cathode, or in the constituent materials of other electrodes, unnecessary electron beams from Ba oxide adhering to the electrodes are reduced. Generation is prevented and Ti
The generation of the unnecessary electron beam can be suppressed by setting the content of γ to the percentage of the deterioration of the static convergence characteristics due to thermal expansion.

As described above, according to the present invention, it is possible to provide a color cathode ray tube having improved electron emission rising characteristics and static convergence characteristics at the initial stage of power-on.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view in an in-line direction illustrating a configuration example of a cathode structure, a control electrode, and an acceleration electrode to which the present invention is applied.

FIG. 2 is a cross-sectional view taken along a central beam passage hole of FIG. 1 and cut at right angles to an in-line direction.

FIG. 3 is a schematic cross-sectional view illustrating a configuration of a shadow mask type color cathode ray tube as an example of a color cathode ray tube to which the present invention is applied.

FIG. 4 is a main part side view for explaining a configuration example of an electron gun structure used for a color cathode ray tube.

FIG. 5 is an in-line direction cross-sectional view illustrating a configuration example of a cathode structure of an electron gun.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electron emission surface 2 Cap-shaped base metal 3 Sleeve 4 Sleeve support 5 Cathode support 6 Insulating substrate 7 Cylindrical cathode 31 Cathode assembly 32 1st electrode (control electrode) 33 2nd electrode (acceleration electrode).

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Yasuhisa Shiraishi 3350 Hayano, Mobara-shi, Chiba Prefecture Within Hitachi Electronics Devices Corporation (72) Ryuichi Kumamoto 3300 Hayano, Mobara-shi, Chiba Electronic Device Hitachi, Ltd. Within the business division

Claims (4)

[Claims] 1. A cathode structure comprising a plurality of cylindrical cathodes for emitting a plurality of electron beams arranged in a horizontal line, and a plurality of cathode structures corresponding to the cylindrical cathodes at least in a horizontal line facing the cylindrical cathode. A control electrode having an electron beam passage hole, and a plurality of electrodes including an accelerating electrode, a focusing electrode, and an anode sequentially arranged from the control electrode side to the fluorescent screen side are embedded in an insulating support rod to maintain a constant in the tube axis direction. A color cathode ray tube having an electron gun fixed at intervals, wherein at least the control electrode and the acceleration electrode are made of a Ni-Fe alloy material containing a small amount of Ti. 2. The method according to claim 1, wherein the Ni—Fe alloy material is 42% Ni—Fe.
The color cathode ray tube according to claim 1, wherein the content of Ti is 0.30 to 0.50%. 3. A cathode structure comprising a plurality of cylindrical cathodes for emitting a plurality of electron beams arranged in a horizontal line, and a plurality of cathode structures corresponding to said cylindrical cathodes at least in a horizontal line facing said cylindrical cathode. A control electrode having an electron beam passage hole, and a plurality of electrodes including an accelerating electrode, a focusing electrode, and an anode sequentially arranged from the control electrode side to the fluorescent screen side are embedded in an insulating support rod to maintain a constant in the tube axis direction. A color cathode ray tube having an electron gun fixed at intervals, wherein at least the control electrode and the acceleration electrode are made of a Ni-Co-Fe alloy material containing a small amount of Ti. 4. The method according to claim 1, wherein the Ni—Co—Fe alloy material is 29% Ni.
-18% Co-Fe, and the content of Ti is 0.3%.
The color cathode ray tube according to claim 3, wherein the content is 0 to 0.50%.