JPS6129052A - Cathode-ray tube - Google Patents

Abstract

PURPOSE:To provide sufficient gas adsorption ability without deterioration of other cathode-ray tube characteristics by connecting the final electrode on fluorescent face side of an electron gun tip to a neck getter through a thermal buffer unit. CONSTITUTION:A neck getter 20 containing nitride is connected to the tip portion of an electron gun 6. And this neck getter 20 is forther connected to the electron gun 6 through a thermal buffer unit 40. The buffer unit 40 is connected thereto by a supporting unit 41 and formed in an annular body so as to surround passing ara of electronic beam 8B, 8G, 8R, and made of such a material that can be subjected to induction heating and that is non-magnetic, e.g. stainless. Such a getter 20 can be heated to evaporate by heating with a toroidal magnetic field 31 generated from a toroidal coil 30 concentrically arranged. Thus, sufficient gas adsorption ability can be obtained and other cathode-ray tube characteristics are prevented from deterioration.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a cathode ray tube, and more particularly to a neck getter.

[Technical background of the invention and points of interest]

In general, a cathode ray tube, such as a color picture tube, has a tube body consisting of a face panel (1), a funnel-shaped funnel (2), and a neck (3), as shown in Figure 8.
) is formed with a fluorescent surface (4) in which a group of fluorescent substances emitting red, green, and blue light are regularly arranged. A shadow mask (5) with a large number of through holes is arranged close to and opposite to this fluorescent surface (4), and electron beams (8B), (8G) and ( An electron gun (6) that emits 8R) is provided. A deflection device (9) is attached to the outside of the funnel (2) in order to deflect and scan these multiple electron beams and project a luminescent image of a certain area on the fluorescent surface (4). . Such a color picture tube is provided with so-called getter devices (7a) and (7b) for absorbing residual gas inside the tube in order to maintain a high vacuum inside the tube. That is, after the tube is evacuated by a normal vacuum evacuation pump, the getter devices (7a) and (7b) are heated from outside the tube using a high-frequency induction heating method to evaporate and scatter the getter substance and adsorb the residual gas in the tube. Further, the thin film formed by the scattered getter material adhering to the inside of the tube adsorbs gas generated during tube operation.

The gas adsorption ability of such a getter device depends on the amount and area of getter scattering. In order to increase the scattering amount and area of the getter, as shown in Figure 8, conventionally a ring-shaped so-called neck getter is installed around the tip of the two-electron gun (6) so as to surround the electron beam passage area.
7a) Alternately, move the funnel (2) from the electron gun (6).
A so-called antenna getter (7b) is often used, which is extended and supported on the tube and directed into the pipe. If the getter substance 9.1 used in these getter devices, such as barium, scatters into the tube, the fluorescent surface C: If it adheres excessively, the light output will decrease and the brightness of the reproduced image will deteriorate. In addition, in a post-acceleration type color picture tube, excessive adhesion to the shadow mask causes bright spots due to field emission on the fluorescent surface, degrading the image quality. Alternatively, in a mask focusing type color picture tube in which different potentials are applied to a plurality of shadow masks, there is a problem in that the electrical insulation of the plurality of shadow masks is destroyed due to transient deposition of getter.

To solve this problem, nitrides such as iron nitride (Fe, N) are compressed and filled into the getter container together with the getter material, nitrogen gas is internalized in the tube by heating the getter container, and this nitrogen gas ( = By colliding the barium that evaporates and scatters, it is possible to prevent the barium from going straight and reduce barium adhesion to the shadow mask and fluorescent surface.However, due to its structure, the antenna getter (7b) has a neck getter ( Since it is placed closer to the shadow mask than in 7a), there is still a high probability that barium scattered by nitrogen gas will adhere to the shadow mask or fluorescent surface.

From this point of view, for example, in a 26-inch 110-degree deflection color picture tube, the neck getter (7a) can be placed farther away than the shadow mask (79a) compared to the antenna getter (7b), so the shadow mask and fluorescent surface It is possible and preferable to significantly reduce the amount of barium deposited on the surface. However, since the neck getter (7a) is arranged in a ring shape surrounding the electron beam passage area, the maximum diameter of the getter container is limited by the neck inner diameter, and the minimum diameter is limited by the maximum interval between the plurality of electron beams. In particular, in-line beam type electron guns are limited by the beam spacing in the in-line arrangement direction. For example, the outer diameter of the neck is 29.11.
At 111, the distance between adjacent beams is 6. f) When a ring-shaped neck getter is applied to a ll+ inline 3-beam color picture tube, the amount of barium that can be evaporated is 180
■It is below. Generally, the amount of evaporated barium required to sufficiently absorb the residual gas inside the tube is, for example, 2001 V or more in a large color picture tube of 20 inches or larger. Therefore, the shortage of barium in the neck getter is decisive, and antenna getters, which have problems due to barium deposition but are relatively free from restrictions on the size of the getter container, are often used.

In contrast to this problem of insufficient barium in the neck getter (2), for example, in Japanese Utility Model Publication No. 12187/1987,
As shown, a plurality of arcuate getters (10a).

(10b) with an electron beam (8B), (8GL (8R)
It has been proposed to avoid the passing position of the neck (3) C2 as a whole and to bridge both ends of the arc-shaped getter with a metal material a. However, the neck getter as shown in FIG. 4 also has other important problems.

A general C di-evaporable getter is made by adding barium-aluminum alloy powder (= nickel, iron, cobalt, etc.) to cause a Tilmit reaction during heating and raise the temperature to a high temperature. When magnetic powder is added to the getter material ζ and connected to the tip of the electron gun, it disturbs the deflection magnetic field distribution on the neck side of the deflection device and seriously affects the convergence characteristics of the color picture tube.

That is, in the case of the neck getter shown in Fig. 4, Fig. 5(a)
And as shown in (b), I: For the horizontal deflection magnetic field o4, the side beams (8B) and (8R) are concentrated to be more deflected, while for the vertical deflection magnetic field 0 (to), the so-called balance is / side beam (8B) which forms a magnetic field.

It acts to further deflect (8R). In FIG. 5, the same elements as in FIG. 4 are designated by the same numbers. Therefore, as shown in Figure 5, the deflection magnetic field is disturbed, and as a result, the convergence pattern of the electron beam on the fluorescent surface is such that the pattern due to the side beam 0 barrel is larger than the pattern due to the center beam a, as shown in Figure 6. This results in the problem of deflection and loss of convergence characteristics.

Such a conventional neck getter (as shown in FIG. At least the outer periphery of each getter on the side opposite to the straight line OI is arranged symmetrically with respect to the straight line (IF
The getter outer local part (17a) is arranged substantially parallel to the straight line 01 and is also opposite to the straight line 01 and is substantially parallel to the straight line (1, 1).

The length e) of (17b) is the maximum distance between electron beams (28
A neck getter configured to be approximately equal to ) has been proposed.

When such neck getters (2oa) and (2ob) are connected to the tip of the electron gun (6), even if magnetic powder such as nickel is added to the getter material, there will be approximately uniform deflection in the electron beam passing region. It can be a magnetic field. That is, as shown in FIGS. 8(,) and (b), the outer periphery (17 m) of the getter facing across the electron beam passage area, (
17b) is approximately parallel to the array line Ql of the electron beam, and its length is approximately equal to the maximum spacing (2s) of the electron beams, so there is no local disturbance in the horizontal deflection magnetic field and the vertical deflection magnetic field. The area of the region that can be filled with barium is dramatically increased compared to the conventional neck getter, and the evaporation of the conventional ring-shaped getter as shown in FIG. Possible amount of barium is 18
If it is 0, the amount of barium in the neck getter shown in Figure 7 can be evaporated, for example, about 2 (30 m9), and it can exhibit sufficient gas adsorption capacity even when applied to large cathode ray tubes of 20 inch or larger. can.

However, neck getters having such good properties are generally heated and evaporated by high-frequency induction heating as shown in FIG. That is, the toroidal coil 00 is
The neck getter (located concentrically with the force) is heated by induction by a toroidal magnetic field Oυ generated by a current supplied from a high-frequency AC power source (not shown). During this induction heating, the toroidal magnetic field is generated by the electron gun (6). The electron gun (6
) The final electrode may be thermally deformed, adversely affecting the passage of the electron beam, and there is also the possibility that gas release from the electrode member may become large. Furthermore, as shown in Japanese Patent Publication No. 51-44046, in order to improve convergence characteristics by controlling the leakage magnetic field of the deflection magnetic field, the magnetic properties of magnetic parts disposed on the electrodes are changed by high-temperature heating. On the contrary, there is a possibility that the convergence characteristics may be deteriorated.

[Purpose of the invention]

The present invention has been made in view of the above points, and an object of the present invention is to provide a cathode ray tube having a neck getter that has sufficient gas adsorption ability and does not deteriorate other cathode ray tube characteristics.

[Summary of the invention]

The present invention utilizes a cathode ray tube (-) in which a neck getter is disposed at the tip of the electron gun, and connects the neck getter to the final electrode on the phosphor side at the tip of the electron gun via a thermal buffer. This is to suppress the heating of the electron gun electrode due to the heating at the time so as not to cause any practical problems.

[Embodiments of the invention]

Hereinafter, two embodiments of the present invention will be described in detail.

FIG. 1 shows a schematic configuration of an in-line beam type color picture tube to which the present invention is applied. In Figure 1, the tube body of a color picture tube consists of a face panel (1), a funnel (2), and a neck 13), and the inner surface of the panel (1) has fluorescent lights that emit red, green, and blue colors. The fluorophores are arranged in a repeating manner in stripes, and light absorbing stripes are formed between each phosphor (2) to form a fluorescing surface (4).
Two opposing shadow masks (5) each having slit-like holes corresponding to a set of red, green, and blue phosphors are arranged at a predetermined interval. Inside the neck (3) are 8 electron beams (8B), (8G) arranged in-line in a direction perpendicular to the phosphor stripes.

An electron gun (6) that emits (8R) is installed inside the funnel (2), and an electron gun (6) is installed outside the funnel (2) to deflect and scan the electron beam and project it within a certain scanning area using a fluorescent surface. Deflection device (
9) is installed. Further, a neck getter blade containing nitride is connected to the tip of the electron gun (6). Furthermore, this neck getter includes an electron gun (6) and a thermal buffer (
41. As shown in FIG. The neck getter consists of an annular body made of a material that can be heated by induction and is made of a non-magnetic material, such as stainless steel.Such a neck getter consists of an iroidal coil arranged concentrically as shown in Fig. 2. It is heated and evaporated by heating with a toroidal magnetic field 01) generated by 01). Here, when a conventional neck getter (7) as shown in FIG. Due to heat conduction through the electron gun (not shown), the final electrode at the tip of the electron gun (6) is simultaneously heated and becomes red hot, rising to a temperature of about 800C. On the other hand, in the case of the embodiment of the present invention shown in FIG. 2, the final electrode at the tip of the electron gun (6) was not observed to become red hot even when the neck getter wire was heated and the getter material was evaporated and scattered. . That is, the leakage of the toroidal magnetic field Gυ consumes its energy by heating the thermal buffer section placed between the neck getter blade and the electron gun (6). 6) Since the energy to heat the
) (41), the heat conducted from the neck getter (a) is absorbed by the thermal buffer section (4G), which also has the effect of reducing heat conduction to the electron gun (6). The thermal buffer section (40) is preferably formed in a ring shape that surrounds the electron beam passage area from the viewpoint of component manufacturing and assembly; Needless to say, other shapes may be used as long as they do not obstruct the passage of the thermal buffer (40).One preferable example is a thermal buffer (40) having a ring shape, and the maximum diameter of which is the same as that of the electron gun (6). It is preferable that the diameter is substantially larger than the maximum diameter of the final electrode.

By doing so, it is possible to further increase the shielding of the toroidal magnetic field toward the electron gun, that is, the consumption of heating energy.

Next, a specific embodiment in which the present invention is applied to a 26-inch in-line beam color picture tube will be described. The neck getter envelope made of stainless steel has in-line electron beams (8B), (8G), and
Two pieces are arranged with line symmetry about the center line connecting (8R). The length 1 of the straight long diameter part of the envelope of the neck getter (20a), (20b) is 11.0 m, the width W of the short circuit part is fi,
5++m, radius of curvature γ of part of corner is 3.251111
1 Height in axial direction of tube 4. Qm, the material thickness is 0.21m.

This getter container is filled with about 280 cm of getter material mainly consisting of barium containing iron dinitride. On the other hand, the substantial final electrode at the tip of the fluorescent surface side of the electron gun is made of stainless steel, and is cup-shaped with a maximum diameter of 2o, a height in the o#i axis direction of 12.7mm, and a material thickness of 0.25mm. Fluorescent side approximately 14
The thickness is 0.2511111 and the width is 3 so that the lower ends of the neck getters (20a) and (20b) are located at the point of sin.
．． It is fixed by a support body (41) made of QMR and ribbon-shaped stainless steel with a length of 20 mm. Furthermore, the thermal buffer section (4
1, the maximum diameter is 23.0ya, the height in the pipe axis direction is 4 (goods)
A V ring made of stainless steel with a thickness of 1.0 mm is fixed via the support (41) so that the lower end of the ring is located at a point 5 fl 1 g away from the final electrode on the side of the fluorescent surface. A toroidal coil is arranged concentrically around the neck of a 26-inch color picture tube with an outer diameter of 29.1 m, which has a neck getter and an electron gun, and the getter container is heated. Conditions were set so that evaporation of the getter started 12 seconds after the start of evaporation, and the current supply was stopped 18 seconds after the start of evaporation.The maximum temperature of the neck getter container at this time was about 1100C, but at the same time a thermal buffer The maximum temperature of the cup-shaped electrode, which is the final electrode of the electron gun, was approximately 600 C.If the electron gun electrode temperature was approximately 600 C, thermal deformation of the electrode would occur. Virtually no problems were observed in terms of gas release or the magnetic properties of the magnetic member for convergence control.Incidentally, with the same configuration and conditions without a thermal buffer, the final electrode It was confirmed that as the temperature reached a maximum temperature of 850C, it became red hot, causing thermal deformation (= serious trouble in gas release and convergence characteristics).

In the above explanation, an example has been explained in which the present invention is applied to an in-line beam type color picture tube, but it goes without saying that the present invention is not limited to this and can be applied to other types of color picture tubes or single beam type cathode ray tubes. stomach.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to obtain a cathode ray tube having a neck getter that has a sufficient gas adsorption function and suppresses deterioration of other characteristics to a practically acceptable level, and is particularly useful for large cathode ray tubes. suitable for

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram showing an inline beam type color picture tube to which the present invention is applied, Fig. 2 is a schematic sectional view to explain the heating action of the neck getter in Fig. 1, and Fig. 3 is a conventional inline beam type color picture tube. A schematic configuration diagram showing a beam-type color picture tube, FIG. 4 is a schematic plan view of a neck showing an example of a conventional neck getter, and FIGS. A schematic diagram to explain the influence of the magnetic field, Figure 6 is a schematic diagram to explain the convergence characteristics on the screen due to the influence of the magnetic field in Figure 5, and Figure 7 is a diagram of the neck showing an example of the neck getter. Schematic plan view, No. 8
8(a) and 8(b) are schematic diagrams for explaining the influence of the magnetic field on the neck getter of FIG. 7, FIG. 9 is a schematic plan view of the neck showing an example of a conventional neck getter, FIG. 10 is a schematic sectional view for explaining the heating action of the neck getter of FIG. 9. (1)... Hanel (21... Funnel (3)...
・Neck (4)...Fluorescent surface (5)...Shadow mask (6)...Fluorescent surface...Neck getter (4fl...Thermal buffer part (Fluorescent surface)...Support Representative Patent Attorney Yu Nori Chika (and 1 other person) 1st
Fig. 2 Fig. 3 Fig. 4 Fig. Q Fig. 7 Fig. 8 (OL) Cb) ~ /7c /2 +-120tz l l 20°R8 (i ・1 □4 1 l aR =
1゜-1111 θ Figure 10') Ql', -

Claims (1)

[Scope of Claims] 1) A tube body consisting of a panel, a funnel, and a neck, a fluorescent surface consisting of a phosphor of at least one luminescent color formed on the inner surface of the panel, and at least one phosphor disposed within the neck. A cathode ray tube comprising at least an electron gun that emits a regular electron beam, a neck getter connected to the tip of the electron gun, and a deflection device that is attached to the outside of the funnel and deflects the electron beam emitted from the electron gun. In,
The cathode ray tube, wherein the neck getter is connected to the electron gun via a thermal buffer. 2) The cathode ray tube according to claim 1, wherein the thermal buffer section is made of a member that can be heated by induction. 3) Claim 2, wherein the thermal buffer section is formed in a substantially annular shape surrounding the electron beam.
Cathode ray tube as described in section. 4) The thermal buffer section is connected via a support piece between the final electrode at the tip end on the fluorescent surface side of the electrodes constituting the electron gun and the neck getter, and the thermal buffer section 4. The cathode ray tube according to claim 3, wherein the maximum annular diameter is larger than the maximum outer diameter of the final electrode.