JPS5836814B2 - cathode ray tube - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cathode ray tube, particularly a mechanism for preventing leakage of X-rays generated from an electron gun.

In general, a cathode ray tube, particularly a color picture tube, has a panel section 1 having a fluorescent surface and a shadow mask, as shown in FIG.
, a funnel-shaped funnel part 2 , and a neck part 4 having an electron gun 3 .

In the case of a pi-potential type electron gun 3, the electron gun 3 includes a heater, a cathode, and first to fourth grid electrodes 01 to G.
A potential difference of about 22 to 30 kV is applied between the third grid electrode G3 and the fourth grid electrode G4, and the electron beam can be focused with this.

FIG. 2 shows the third and fourth grid electrodes G3 of the electron gun 3.
, shows the vicinity of G4.

In the figure, the third and fourth grid electrodes G3, 0
4 are fixed by glass rods 5 and are insulated from each other.

6 is a ball piece gauge fixed to the fourth grid G4, and this is in contact with the internal conductive coating 7 of the funnel portion 2 by a conductive spring attached to its head.

Reference numeral 8 denotes a cylindrical shield plate having one end fixed to the ball piece gauge 6 and extending in the direction of the cathode K, which is located near a portion facing the gap between the third grid electrode G3 and the fourth grid electrode G4. This serves to prevent charges from being accumulated in the electron beam, thereby preventing changes in the direction of the electron beam due to the charges.

In FIG. 1, reference numeral 9 denotes a magnet assembly, which consists of a holder 91 made of an insulating material placed around the outer periphery of the neck portion 4 and a purity magnet 92 attached to the outer periphery of the holder 91.
, a 4-pole magnet 93, a 6-pole magnet 94, a spacer 95, and a lock link 96. This magnet assembly 9 enables purity adjustment or compersence adjustment.

10 is a cylindrical lead material attached and fixed to the outer periphery of the neck part, and this is the third grid electrode G3 and the fourth grid electrode G4.
It functions to shield X-rays generated by sparks between the

According to the conventional structure described above, the lead material 10 is directly fixed to the neck portion 4 and is separate from the magnet assembly.

However, according to the above structure, when attaching the magnet assembly 9 and the lead material 10, it is necessary to perform two operations: winding the lead material 10 and then attaching the magnet assembly 9 thereon. This method has the drawback that the mass productivity of the tube itself cannot be improved, and furthermore, the function of the magnet assembly 9 is impaired due to variations in the mounting position of the lead material 10.

Therefore, an object of the present invention is to eliminate the need for separately attaching the lead material 10 when attaching the magnet assembly 9, and will be described in detail below using examples.

FIG. 3 is a sectional view showing the cathode ray tube according to the present invention, in particular the vicinity of the third and fourth grid electrodes Q3 and Q4;
The same reference numerals are used for the same parts as in the figure.

11 is a cylindrical lead material attached to the outer periphery of the shield plate 8.

According to this structure, the lead material 11 is the shield plate 8.
, and sufficiently surrounds the gap between the third grid electrode G3 and the fourth grid electrode G4, so that both electrodes Q3
, G4 can be reliably shielded from the X-rays generated from the gap.

In this case, since the lead material 10 is not required, the work of attaching the magnet assembly 9 becomes simple.

Here, the lead material 11 may be attached to the inner periphery of the shield plate 8, or may be mixed into the shield plate 8.

Furthermore, the shield plate 8 itself may be formed from the lead material 11.

Further, as a method for attaching the lead material 11 to the inner and outer peripheries of the shield plate 8, it is also possible to integrate a cylindrical lead material with the shield plate 8, but it is also possible to apply lead material powder to the shield plate 8. Alternatively, it may be vapor deposited.

Further, the present invention can also be applied to a cathode ray tube having a unipotential type electron gun.

As explained above, according to the present invention, lead material is installed and mixed on the outer periphery, inner periphery, or inside of the shield plate and integrated;
Alternatively, since the shield plate eye is made of lead material, there is no need to attach a separate lead material when attaching the magnet assembly, improving mass productivity. , G4, the effect of suppressing X-rays becomes greater.

[Brief explanation of the drawing]

1 and 2 are simplified structural diagrams showing an example of a conventional cathode ray tube, and FIG. 3 is a simplified structural diagram showing an example of a cathode ray tube according to the present invention. 1... Hannel part, 2... Funnel part, 3... Electron gun, 4... Neck part, 5
...Glass rod, 6...Pole piece gauge, 7...Internal conductive coating, 8...
Shield plate, 9... Magnet assembly, 10,
11...Lead material.

Claims (1)

[Claims] 1 A panel part, a funnel part, and a neck part, an electron gun housed in the neck part and equipped with a ball piece gauge on the panel part side, and a shield plate connected to the ball piece gauge and covering the gap between the grid electrodes. A cathode ray tube comprising at least the above, wherein a lead material is integrated into the outer periphery, inner periphery or inside of the shield plate, or the shield plate is formed from a lead material.