JPS63241845A - Cathode-ray tube - Google Patents

Abstract

PURPOSE:To prevent the electrification of a getterring by scattered electron beams or the like and prevent the occurrence of the image distortion by electrically insulating the getterring from a high-resistance inner conductive film with a heat-resistant insulating connector. CONSTITUTION:A guide groove 14a is coupled and fixed to a cross bar 8a stored in the recess 8c at the center of a getter ring 8 and welded and fixed at the center of the getterring 8, then the window hole 15b of a holder 15 is fitted to a connector contact point 14b, next the holder 15 made of nonmagnetic alloy is welded and fixed to the ring 8 to assemble an insulating connector 14. Accordingly, even if the high-frequency current is applied to a heating device coil 13 to heat the ring 8, the thermal conductivity of the connector 14 is low, thus no thermal shock is applied to a high resistance inner conductive film 10, and the resistance value of the contact point 14b is not increased. In addition, the ring 8 is invariably connected to an anode 4 electrically with a getter spring 7, and the electrification by scattered electron beams or the like does not occur.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a soft flash type cathode tube.

[Conventional technology]

FIG. 7 is a partially cutaway side view of a conventional soft flash type cathode ray tube, and FIG. 8 is a sectional view of the main parts thereof. In the figure, an electron gun 3 is enclosed in a neck portion 2 of a cathode ray tube envelope 1 . A pulse spacer 5 is attached to the anode 4 of the electron gun 3.
and r-cutter 6 are installed. The r-cutter 6 has an r-cutter spring 7 and a getter ring 8 with an insulator 9 inserted between them. One end of the r-shaped spring 7 is welded to a KP twine ring 8, and the other end is welded to the anode 4. The insulator 9 is provided to prevent current from flowing through the tube 7 when discharging inside the tube.

Reference numeral 10 denotes a high resistance internal conductive film formed on the inner wall of the funnel la of the cathode ray tube envelope l, and this high resistance internal conductive film 10 and the getter spring 7 are electrically connected via a connector 11. There is. On the other hand, the spacer 5 is in contact with the low resistance internal conductive film 12 on the inner wall of the neck portion 2 . The high resistance internal conductive film 10 generally has a specific resistance of 1Ω−Ω
Compared to the low-resistance internal conductive film 12 below, which has a specific resistance of 1 Ω, a large amount of metal oxide such as titanium oxide is mixed in.

[Problem that the invention seeks to solve]

During the manufacturing process of such a cathode ray tube, an induced current is caused to flow from the outside of the cathode ray tube by the high frequency heating device coil 13.
Getter ring is heated for 8t and getter flash is performed. At this time, Gettering 8 is heated to 800℃~1000℃.
℃ or higher, the temperature of the high-resistance internal conductive film lO in contact with the connector 11 rises to 400℃ to 800''C.The time required for this getter flash is about 30 seconds to 1 minute, so The internal conductive film 10 of the resistor was subjected to a sudden thermal shock, and phenomena such as cracks occurred at the contact part with the connector 11, and the resistance decreased to 50%.
It may exceed MΩ. For this purpose, since the insulator 9 is interposed between the getter ring 8 and the anode 4, the getter ring 8 is electrically floating from the high-resistance internal conductive film 10. When the cathode ray tube is operated in this state, electrons from the electron gun 3 collide with the fluorescent surface of the cathode ray tube (not shown), and some of the scattered electrons are captured by the getter ring 8. , gradually becomes negatively charged (voltage).

Due to this charge, the electron beam passing near the getter ring 8 is bent and deviates from its normal trajectory, resulting in distortion of the image displayed on the screen of the cathode ray tube.

It is not clearly understood why the portion of the high-resistance internal conductive film 10 in contact with the connector 11 has a high resistance of 50 MΩ or more. Since the graphite, water glass, and metal oxide that make up this conductive film 10 have different coefficients of thermal expansion, the rapid temperature change during the getter flash causes this conductivity inside the pattern 10. It is assumed that cracks have formed and the conductivity has been lost.

This invention was made to solve the above-mentioned problems, and it is a cathode wire that does not cause any undesirable symptoms even if the resistance of the high-resistance internal conductive film in contact with the getter connector increases during getter flash. The aim is to obtain a tube.

[Means for solving problems]

In the cathode ray tube according to the present invention, the getter ring and the high-resistance internal conductive film on the inner surface of the funnel portion are electrically insulated by an insulating connector made of a heat-resistant insulator.

[Effect]

In this invention, a heat-resistant insulator is used as the insulating connector, so the resistance of the high-resistance internal conductive film at the contact point of this connector does not increase, or even if it increases, the getter ring is always in electrical contact with the anode. Therefore, charging due to scattered electron beams, etc. does not occur, and image distortion does not occur.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure is a sectional view of a main part of a cathode ray tube, and 14 is a heat-resistant insulated connector electrically insulated from a high-resistance internal conductive film 10 provided in a gutter ring 8. Therefore, the insulator 9 at the center of the conventional gettersgel ring 7 is no longer necessary. Note that the other parts are the same as those in the conventional example shown in FIG. 8, are given the same reference numerals, and description thereof will be omitted.

2 and 3 show the structure of how the insulated connector 14 is attached to the getter ring 8, and FIGS. 4 to 6 show the getter ring 8 and its structure. ! 2 shows an exploded perspective view of the edge connector 14. FIG. That is, while the insulated connector 14 is housed in the recess 8C at the center of the getter ring 8, the guide groove 1ja is fitted into the cross bar 8a fixed by welding to the center of the getter ring 8, and then the contact 14b of the insulated connector 14 is fixed.
It is assembled by inserting it into the window hole 15b' of the holder 15, and then welding and fixing it to the getter ring 8 made of a non-magnetic alloy.

In the cathode ray tube of the present invention configured as described above, even if a high frequency current is applied to the high frequency heating device coil 13 and the getter ring 8 is heated to 800°C to 1000°C, the insulated connector 14 has low thermal conductivity. Therefore, the high resistance internal conductive film 10 is not subjected to thermal shock, and the resistance value does not become large at the contact point 14b. Even if the resistance value increases by 7%, because the getter ring 8 is always electrically connected to the anode 4 and the getter spring 7, charging due to scattered electron beams will not occur, and the cathode ray tube will not be charged. It does not distort the image displayed on the screen.

Generally, the total weight of the getter ring 8 and its attached parts is light because the spring force of the getter ring 7 is used to press it against the cathode ray tube envelope. 14 should be as small as possible. With the above structure, the small insulating connector 14 can be stably fixed to the getter ring 8. 1f
In order to prevent discharge from occurring between the cf stumbling ring 8 and the optical surface of the high-resistance internal conductive film IO, the holder 15 must be placed as far away from the high-resistance internal conductive film IO as possible. It has excellent characteristics in several respects.

Conventionally, when gettingtering 8's getter flash,
Since the ring 8 reaches a high temperature, the cathode ray tube envelope may be damaged by the heat radiation. As a countermeasure against this, for example, US Pat. No. 3,590,758 and US Pat.
An annular ceramic base as described in Japanese Utility Model Publication No. 05, Japanese Utility Model Publication No. 58-13575, etc. is placed between the getter ring and the envelope. This ceramic base is placed in a position opposite to the channel 5b (4' groove filled with barium particles) of the getter ring 8.
It blocks high temperatures from b. On the other hand, in the present invention, the K insulated connector 14 (which does not easily become hot during getter flashing) is disposed in the recess 8c in the center of the getter ring 8, so that the purpose and structure are different.

〔Effect of the invention〕

As explained above, according to this invention, getter + IJ
By electrically insulating the song's high-resistance internal conductive film with a heat-resistant insulating connector, it is possible to block the current flowing through the getter ring during internal discharge of the cathode ray tube, and the getter ring is always Since it is electrically connected to the anode, it is possible to prevent the getter ring from being charged by scattered electron beams, etc., resulting in a cathode ray tube without image distortion.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of the main parts around the getter of a cathode IJ tube according to an embodiment of the present invention, and FIGS. 2 and 3 are bottom views of the getter ring and insulated connector, and cross-sectional views along the , FIGS. 4 to 6 are exploded perspective views of the getter ring and insulated connector, FIG. 7 is a broken cross-sectional view of a conventional cathode ray tube, and FIG.
The figures are the same (cross-sectional view around the getter. la... Funnel part, 4... Anode, 7... Getter ring, 8... Getter ring, 8a...
Cross bar, 8c... recess, IO... high resistance internal conductive film, 14... insulated connector, 14a... guide groove,
14b...Contact, 15...Holder. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (3)

[Claims] (1) The resistance value between two points 1 cm apart of the internal conductive film provided on the inner surface of the funnel part of the cathode ray tube is 100Ω to 100Ω.
In a cathode ray tube that is formed at least in part by a high-resistance internal conductive film with an electrical resistance of 0KΩ, a heat-resistant insulated connector is provided on the getter ring of the antenna getter provided at the tip of the electron gun, and the contacts of this connector are A cathode ray tube characterized in that the getter ring and the high-resistance conductive film are electrically insulated by contacting the high-resistance conductive film. (2) The insulated connector has a guide groove into which a welded crossbar is fitted near the center line of the getter ring, and is formed so as to be in contact with the recess in the center of the getter ring partially or over the entire circumference. A cathode ray tube according to claim 1. (3) The cathode ray tube according to claim 1, wherein the insulating connector is fixed to the high-resistance conductive coating side of the getter ring with a holder made of a material made of a non-magnetic alloy.