JPS63115025A - Measuring method for gas pressure of cathode-ray tube - Google Patents

Abstract

PURPOSE:To measure the gas pressure in a cathode-ray tube while the cathode- ray tube is in operation and to improve the measurement sensitivity by fitting an ion collector for the in-tube gas to a funnel part. CONSTITUTION:The ion collector 33 is fitted on the internal surface of the funnel part 24 across an insulator 34 and the lead wire of the collector 33 is led out of the tube from a sealing part which connects a panel part 18 and the funnel part 24 to each other. Then an electron gun 3 is put in a neck part 2 and a vacuum is produced in the tube. Then, a specific voltage is applied to the electron gun 3 and an electron beam 27 is emitted toward the internal surface of the panel part. Then, a voltage which is lower in level than an anode voltage applied to the anode of the electron gun 3 is applied to the collector 33. Then, the electron beam 27 collides against many gas molecules remaining in the tube to ionize them. Then, + ions ionized by the electron beam 27 are collected by the collector 33 in the area between the anode of the electron gun 3 and the collector 33 and an ion current conducted through the collector 33 is displayed outside the tube.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for measuring gas pressure in a cathode ray tube.

[Prior Art] Figure 3 shows a circuit for measuring gas pressure in a conventional cathode ray tube, in which an electron gun (3) is enclosed in the neck (2) of the cathode ray tube (1). , the electron gun (3) has a cathode (5), a first grating (6), and a second grating in order from the stem part (4).
A grating (7), a third grating (8), and an anode (9) are supported by bead glass α0 at appropriate intervals. Cathode powder Q2 such as metal oxide is applied on the cathode cup (III) of the cathode (5),
A heater αJ is housed in the cathode cup qD. In addition, a cup Q4) is welded on the anode (9).
A spacer q51 and a getter spring α with a getter □ mark attached to the tip are welded to the cup (141).On the other hand, the panel part a& of the cathode ray tube (1)
The inner surface is coated with a phosphor, and on top of the phosphor (1!It), an aluminum pack ■ is deposited.
A shadow mask Ω is held at a position slightly away from the aluminum pack by mask pins embedded in the skirt of the panel. The inner surface of the funnel part C41 of the cathode ray tube (1) is coated with an internal conductive film that is electrically connected to the anode terminal, and a getter film (2) is coated on top of it.
is formed. In addition, ■ is the first grid power supply, and ■ is the second grid power supply.
Grid power supply, country is ion collector power supply.

When measuring the gas pressure inside the cathode ray tube (1),
The heater a3 shown in FIG. 4 is ignited, the first grid voltage is applied to the first grid (6), and the second grid voltage is applied to the second grid (7), thereby drawing out the electron beam opening from the cathode αB. , apply an ion collector voltage to the third grid (8). At this time, gas molecules remaining in the tube are ionized by the electron beam surface, and the generated + (plus) ions are collected in the third lattice (8). By measuring this ion current with an ammeter, the gas pressure inside the cathode ray tube (1) can be measured.

[Problems to be solved by the invention] However, in the above conventional gas pressure measurement circuit, the third grid (
3), it is not possible to measure the gas pressure in the tube in an operating state in which the electron beam α is applied to the phosphor (19) or shadow mask 0 shown in FIG. 3.

Therefore, the +ion gas molecules generated in the tube during operation are not collected in the third grid (8), resulting in a measurement error between the actual gas pressure and the measured gas pressure.

In addition, since the electron beam ionizes only the gas molecules in a narrow region between the second lattice (7) and the third lattice (8), the number of positive ions in the ionized gas molecules is small, resulting in low measurement sensitivity. There was a drawback.

This invention was made in order to solve the above-mentioned conventional problems, and it is possible to measure the gas pressure inside the cathode ray tube while the tube is in operation, and to improve the measurement sensitivity. The purpose is to provide a method.

[Means for solving problems]

The method for measuring gas pressure in a tube according to the present invention involves first attaching an ion collector to the inner surface of a funnel section via an insulator, and then connecting the lead wires of the ion collector to the outside of the tube through the sealing section that connects the panel section and the funnel section. Pull out. After evacuating the inside of the tube, a predetermined voltage is applied to the electron gun to emit an electron beam toward the inner surface of the panel section. Further, a voltage lower in level than the anode voltage applied to the anode of the electron gun is applied to the ion collector via the lead wire. The positive ions of gas molecules ionized by the electron beam in the region between the anode of the electron gun and the ion collector are collected into the ion collector, and the ion current flowing through the ion collector is displayed outside the tube.

[Effect]

According to this invention, since the ion collector is enclosed in the funnel part, the emission of an electron beam by the electron gun and the collection of positive ions by the ion collector can be performed simultaneously. This makes it possible to measure gas pressure while the cathode ray tube is in operation. In addition, since the ion collection area is between the anode of the electron gun and the ion collector, the distance between the areas is wider compared to when the electron gun is used as an ion gauge, and the number of collected + ions is increased. increase

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic diagram of a cathode ray tube equipped with a gas pressure measuring circuit, which is an embodiment of the present invention. In the figure, field is +
It is an ion collector for collecting ions, and the funnel part □
It is attached on the internal conductive film ■ of □□ via an insulator. The mounting position of this ion collector field is set, for example, near the sealing part with the mark α on the panel part. (to) is a lead wire such as a dumet wire,
One end is connected to the ion collector, and the other end is drawn out of the tube through the enclosure and connected to one pole of the ion collector power supply port. The voltage of the ion collector power supply q is at a level lower than the anode voltage applied to the anode terminal ω of the funnel part, for example, several volts.
The voltage level is set to a negative voltage level of ~ several hundred volts. Thereby, + ions of gas molecules ionized in the region between the cup circle of the anode (3) in the electron gun (3) and the ion collector ω can be collected at the ion collector port.

In addition, the ten poles of the ion collector power supply port above are connected to the display circuit (
) is connected to the connection point +411 between the anode power supply ■ and the anode terminal ■. The display circuit (to) includes, for example, an amplifier and an ammeter (not shown), and serves to amplify the ion current flowing through the ion collector port, measure and display the amplified current.

In the above configuration, in order to measure the gas pressure inside the cathode ray tube (1), first, before sealing the panel part a& and the funnel part, an insulating material is inserted into the inner surface of the funnel part (2). The ion collector (2) is attached, and the panel part G81 and the funnel part example are sealed with frit glass while the lead wire (to) thereof is drawn out to the outside. After enclosing the electron gun (3) in the neck portion (2), the inside of the tube is evacuated to create a vacuum. After that, a voltage of a predetermined level is applied to the first to third grids (6) to (8) and the anode (9) of the electron gun (3) by the first to third grid power supplies ■ to ■ and the anode power supply ■. Along with the ion collector■
A negative voltage lower than the anode voltage is applied to the anode. Here, to prevent the electron beam gradient from impacting the ion collector port,
Adjust the current flowing through the deflection coil I. Electron gun (3)
The electron beam from the cathode (5) is accelerated by the first to third grid voltages and the anode voltage, is deflected by the deflection yoke I, and impacts the shadow mask circle and the fluorescent light beam. During this time, the electron beam collides with many gas molecules remaining in the tube, ionizing them. Further, the electron beam collides with the shadow mask 0 and the phosphor αS, releases gas molecules adsorbed on the surfaces thereof, and at the same time ionizes these gas molecules. The positive ions of the ionized gas molecules are collected at the ion collector port, and the ion current is amplified and displayed by the display circuit (2).

Therefore, + ions in the tube gas generated during the operation of the cathode ray tube (1) are effectively collected, and compared to the conventional case where the electron gun (3) is used as an ion gauge, the actual gas pressure is Measurement errors can be kept small.

In addition, in order to ionize the gas in the ion collection region between the cup (141) of the anode (9) and the shadow mask C11, the gas remains in the narrow region between the second grating (6) and the third grating (7) as in the conventional case. Compared to ionizing only the gas molecules that are present, the number of + ions collected increases and the sensitivity of measuring the gas pressure inside the tube becomes extremely high.This significantly improves the reliability of the measurement results.

As another embodiment of the present invention, as shown in FIG. (451), and this display device e451 may be used to measure the gas pressure during operation within the tube. In this case, safety is ensured because no anode voltage is applied to the amplifier (42).

[Effects of the Invention] As described above, according to the present invention, since the ion collector for the tube gas is attached to the funnel part, the tube gas pressure can be measured while the cathode ray tube is in operation. Therefore, + ions generated within the tube during operation of the cathode ray tube can be effectively collected, and measurement errors can be eliminated.

Furthermore, since the number of + ions collected is increased compared to the conventional method, there is an effect that measurement can be performed with high sensitivity.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing one embodiment of the present invention, FIG. 2 is a schematic diagram showing another embodiment of the invention, and FIG. 3 is a diagram of a cathode ray tube equipped with a conventional tube gas pressure measuring circuit. A schematic configuration diagram, FIG. 4 is an enlarged view of the vicinity of the cathode in FIG. 3. (1)...Cathode ray tube, (2)...Neck part, (3)
...electron gun, α&...panel section, (foundation)...funnel section, of course...electron beam, can...ion collector, (to)...absolute totality, (to)... ·Lead. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Claims] (1) In a gas pressure measurement method for a cathode ray tube, in which the gas pressure inside the cathode ray tube is determined by measuring the gas pressure inside the cathode ray tube in which the panel portion is sealed against the funnel portion and the electron gun is included in the neck portion, the degree of vacuum is determined. An ion collector is attached to the inner surface of the funnel section via an insulator, the lead wire of the ion collector is pulled out of the tube from the sealing section that connects the panel section and the funnel section, and after the inside of the tube is evacuated, it is connected to the electron gun. Applying a predetermined voltage to emit an electron beam toward the inner surface of the panel part, and applying a voltage at a lower level than the anode voltage applied to the anode of the electron gun to the ion collector via the lead wire, Gas pressure of a cathode ray tube characterized in that positive ions of gas molecules ionized by an electron beam in the region between the anode and the ion collector are collected in the ion collector, and the ion current flowing through the ion collector is displayed outside the tube. Measuring method.