JPH0736346U - Cathode support structure - Google Patents

Abstract

(57) [Summary] (Corrected) [Purpose] In a color CRT, it is possible to prevent the white balance from breaking down until it stabilizes after ignition of the electron gun.
A cathode support structure for a cathode ray tube, which can prevent deterioration of insulation between the first grid and the cathode and between the cathodes even after long-term use. A ceramic substrate 1 is provided with a cathode support cylinder 3 corresponding to an electron gun axis, two trapezoidal grooves 13 having two holes 14 intersecting with the longitudinal direction are formed in the ceramic substrate, and another tongue is formed. Forming a substrate support 2 in which two supporting plates 21 each having a strip 24 are connected in a U shape by a bridge portion, and the supporting plates are housed in the grooves and the tongues are housed in the holes. It was provided, and each of the above-mentioned housing portions was fixed with an insulating adhesive 52 such as glass.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a cathode supporting structure used in a cathode ray tube, and more particularly to a cathode supporting structure of a color cathode ray tube in which a plurality of cathodes are linearly arranged on a single ceramic substrate.

[0002]

[Prior art]

 Conventionally, as a condition necessary for a three-electron gun for a color cathode ray tube, the temperature is sequentially increased from the one closer to the heat source such as the heater, cathode, and the first grid together with the heater ignition, and the change and deformation of the parts due to thermal expansion occur. , This changes with time, resulting in a change in size between the grid and the cathode. If this causes a difference between the axes of the three electron guns, the white balance adjusted in the stable state will collapse from immediately after the heater is ignited until it reaches the stable state.

Also, as another problem, the cathode is generally an oxide cathode such as (Ba Sr Ca) o as an electron emission source, which evaporates Bao and Ba during operation. The cathode base metal also contains a reducing agent such as Mg in Ni, and this is gradually evaporated. If this evaporated substance adheres to the ceramic substrate or glass surface, the surface resistance value of the insulator is lowered. Since the insulation failure between the first grid and the cathode and the cathode and the cathode is a fatal defect in the cathode ray tube, such an accident must be completely prevented.

Therefore, it is necessary to take measures to prevent the vapor deposition film on the surface of the insulator, and conventionally, a circular groove has been provided on the ceramic substrate centering on the cathode. However, in the electron gun structure in which the cathodes are arranged in a line on the substrate like the electron gun arrangement of the in-line type color cathode ray tube, it is useful to cut the circular groove for each cathode in terms of size and to maintain insulation between the cathodes. The standing structure is difficult.

[0005]

The present invention has been made to solve the above-mentioned various problems, and its purpose is to break the white balance before the heater is ignited and the stable state is reached. It is an object of the present invention to provide a cathode supporting structure used for a color cathode ray tube.

Another object of the present invention is to provide a cathode support structure for a cathode ray tube, which can prevent a decrease in insulation resistance between the first grid and the cathode and between the cathode and the cathode, which is caused by the use of the cathode ray tube. Is.

[0007]

[Means for Solving the Problems]

 This invention for achieving the above-mentioned object is described as follows: a cathode supporting cylinder 3 provided on a ceramic substrate 1 in correspondence with an electron gun axis; a direction intersecting the ceramic substrate 1 with a longitudinal direction of the ceramic substrate 1. Two grooves 13 each having a substantially trapezoidal cross section; holes 14 respectively formed in the two grooves 13; two support plates 21 connected by a bridge portion 23 in a substantially U-shape Substrate support 2; Tongue-shaped pieces 24 respectively formed on both the support plates 21; The tongue-shaped pieces 24 are accommodated in the holes 14, the support plate 21 is accommodated in the grooves 13, and the accommodating portions are fixed. The cathode support structure is characterized by comprising an insulating adhesive 52 such as glass provided on the substrate.

[0008]

[Action]

 This invention is constructed as described above, and the support plate 21 and the tongue piece 24 of the substrate support 2 are housed in the grooves 13 and the holes 14 of the ceramic substrate 1, respectively, and these housing parts are made of an insulating material such as glass. By fixing with the adhesive 52, the supporting plate 21 and the tongue-shaped piece 24 are fixed as they are without any processing such as caulking. Since it does not have it, it does not undergo a biased deformation with respect to the heater ignition and the subsequent temperature rise. Therefore, it is possible to prevent the white balance from being disturbed from the ignition of the color CRT until the stable state is reached.

Further, the two support plates 21 of the substrate support 2 are formed into a substantially U shape by the bridge portion 23, and the support plates 21 are housed in the groove having the substantially trapezoidal cross section. Naturally, both sides of the support plate 21 become slopes of a substantially trapezoidal groove, and the slopes form a blind spot of the cathode vapor, so that the attachment of the cathode vapor to the slope is in the other part. In comparison, it is extremely small and does not cause any problem. Further, the support plate 21 planted in the trapezoidal groove 13 forms a so-called partition with respect to the vaporized material, and therefore, the vaporized material can be prevented from adhering to the adjacent slope on the electron gun side. Therefore, the insulation between the three electron guns can be maintained. Therefore, it is possible to prevent a decrease in insulation between the first grid and the cathode and between the cathodes due to long-term use.

[0010]

【Example】

 FIG. 1 is a schematic perspective view of an indirectly heated cathode supporting groove body according to the present invention. Reference numeral 1 is a ceramic substrate common to three electron guns, which is formed of ceramics, and commonly uses a plurality of cathodes described later. keeping.

Reference numeral 2 denotes a substantially U-shaped cross section including two support plates 21 for connecting the ceramic substrate 1 to a bead glass (not shown) of the electron gun assembly and a bridge portion 23 for bridging the support plates 21. The formed substrate support is designed to be incorporated into the electron gun assembly after being bonded to the ceramic substrate 1.

Reference numeral 3 denotes three cathode supporting cylinders corresponding to the electron gun shaft, which are fixed to the ceramic substrate 1 and to the through holes 11 thereof with an adhesive 51 such as glass as shown in FIG. .

Numeral 4 is a commonly used cathode as shown in FIG. 2, which is formed by embedding the cathode supporting structure in a bead glass together with other electron gun parts (first grid to sixth grid) not shown, and then using an air micrometer or the like. While measuring the distance between the first grid and the cathode, insert it into the cathode support tube 3 and weld it to the cathode support tube 3 at an appropriate position, then put a heater (not shown) in the cathode 4 and complete the electron gun assembly. To do.

The features of the present invention will be described with reference to the exploded perspective view of the cathode support structure shown in FIG. In the figure, reference numeral 1 is a ceramic substrate provided with through holes 11 for fixing the three cathode supporting cylinders 3 and grooves 12 (FIG. 5) for filling the vitreous adhesive 51 at positions corresponding to the electron gun axis. Reference numeral 2 is a substrate support, which has a substantially U-shaped cross section formed by two support plates 21 each having a notch 22 for embedding in the bead glass and a bridge portion 23 connecting these. is there.

The ceramic substrate 1 and the substrate support 2 are joined to each other by two pieces on one side provided on the support plate 21, and a total of four tongue pieces 24 on both support plates 21 and two strips provided on the ceramic substrate 1. A groove 13 and a total of four holes 14 for fixing the tongue strips 24 provided at two places in each groove 13 are provided, and the tongue-shaped pieces 24 are inserted into the holes 14 to melt the vitreous fixing adhesive 52. Stick to it.

The structure of the tongue piece 24 of the substrate support 2 and the groove 13 provided in the ceramic substrate 1 will be described with reference to a partially enlarged view shown in FIG. The groove 13 is cut into a trapezoidal shape with respect to the surface of the ceramic substrate 1, and the groove bottom is formed into a right angle. At this bottom, the tongue piece 24 and the hole 14 for fixing are connected.

Next, an outline of the assembly of this cathode support structure will be described. At the time of assembly, the exploded perspective view shown in FIG. 3 is turned upside down, but the ceramic substrate 1 is overlaid on the substrate support 2. At this time, the groove 13 provided on the ceramic substrate 1 has a trapezoidal cross section, and the fitting irregularity caused by the dimensional tolerance between the ceramic substrate 1 and the substrate support 2 is absorbed by the trapezoidal groove, which is an incompatible product. Can be eliminated.

Next, as shown in FIG. 5, the cathode support tube 3 is put into the through hole 11 of the ceramic substrate 1, and the glass adhesive 51 is put into the groove 12 on the outside of the cathode support tube 3. Next, as shown in FIG. 4, the vitreous adhesive 52 is put into the hole 14 for fixing the tongue 24, and the vitreous adhesives 51 and 52 are melted and fixed in an inert gas stream.

Next, FIG. 4 will be described. In this invention, as described above, regarding the insulation between the cathodes, the trapezoidal groove 13 and the supporting portion 21 do not come into contact with each other near the surface of the ceramic substrate 1 as shown in FIG. , It was devised to maintain insulation in this space. The slopes of the trapezoidal groove 13 are provided on both sides of the support plate 21, and the evaporations of any of the three electron guns are always formed as blind spots. Further, the bridging portion 23 of the substrate support 2 covers the periphery of the central electron gun and has an insulating effect on the evaporated material. The bridging portion 23 also serves to make the support plate 21 stand at a right angle to the ceramic substrate 1.

[0020]

[Effect of device]

 This invention is constructed as described above, and the substrate support 2 and the ceramic substrate 1 are combined and fixed in a natural form and have no unnecessary distortion. Since the conventional processing such as caulking and tightening has large distortion, it causes irregular changes due to the thermal expansion that occurs with the heater ignition, and because this is not uniform, it stabilizes immediately after the heater ignition (about 30 minutes). ) Until the color CRT color shift occurs. Since the present invention has no unnecessary distortion, the effect of the thermal expansion of the three-electron gun is uniform and the color shift does not occur in the cathode ray tube.

Another effect is that the trapezoidal groove 13 and the support plate 21 are not in contact with each other on the surface of the ceramic substrate 1 but leave an acute triangular space, and insulation can be maintained in this space. The trapezoidal groove 13 has slopes on both sides of the support plate 21, and is configured so that the vaporized substances of the three electron guns will always be blind spots. Therefore, it is possible to greatly suppress the insulation deterioration caused by the evaporated material. Further, the support plate 21 planted in the trapezoidal groove 13 serves as a so-called partition for the vaporized substances, and therefore, the vaporized substances can be prevented from adhering to the adjacent slope on the electron gun side. Therefore, the insulation between the electron guns can be maintained.

Next, the difference between this device and the known example will be described. As a known example, Japanese Utility Model Publication No. 58-14514 discloses an example in which two supporting pieces are provided on a ceramic substrate. In this example, the supporting piece is on the back side of the ceramic substrate (the side opposite to the electron emission surface) and does not serve as protection from evaporation to lower the insulation. Further, it is difficult to vertically set the support pieces to the ceramic substrate by inserting the support pieces into two pieces and inserting them into the trapezoidal groove as in the present invention.

In this respect, according to the present invention, the two support plates 21 and the bridging portion 23 are provided and integrated, and the support plate 21 is planted at right angles to the ceramic substrate 1 without any special work during assembly.

[Brief description of drawings]

FIG. 1 is a perspective view showing an outline of a cathode supporting structure according to an embodiment of the present invention.

FIG. 2 is a perspective view of the cathode shown in FIG.

3 is an exploded view of the cathode support structure shown in FIG. 1. FIG.

FIG. 4 is a sectional view taken along the line A-A ′ in FIG.

5 is a cross-sectional view taken along the line B-B ′ of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ceramic substrate 2 Substrate support 3 Cathode support cylinder 4 Cathode 13 Groove 14 Hole 21 Support plate 24 Tongue piece 52 Insulating adhesive such as glass

Claims (1)

[Scope of utility model registration request] 1. A cathode support cylinder 3 provided on a ceramic substrate 1 so as to correspond to an electron gun axis; two cross-sections formed on the ceramic substrate 1 in a direction intersecting the longitudinal direction of the ceramic substrate 1. Trapezoidal groove 13; holes 14 formed in the two grooves 13 respectively;
Substrate support 2 formed by connecting in substantially U-shape by 3; Tongue pieces 2 formed on both support plates 21
4; the tongue-shaped piece 24 is housed in the hole 14, the support plate 21 is housed in the groove 13, and the insulating parts 52 made of glass or the like are provided by fixing the housing parts. A cathode support structure characterized by: