JPH0221538A - Eccentricity measuring device of electron gun - Google Patents

Abstract

PURPOSE:To make it possible to measure the eccentricity at a high accuracy and a high reliability by measuring the distance from a specific position to the outer peripheral surface of an electrode with no contact, and displaying the value related to the eccentricity of an electron gun from the output of the measuring device. CONSTITUTION:A measuring device having a sensor 20 such as a magnetic sensor, for example, to measure the distance l from a specific position 19 to the outer peripheral surface of an electrode 5 at the top with no contact is provided. The sensor 20 is installed to a rack 21, making the sensor 20 movable freely in the horizontal direction by a horizontal movement mechanism 22, and making the rack 21 movable in the vertical direction freely by a vertical movement mechanism 23. The sensor 20 is arranged closely adequately opposing to the outer peripheral surface of the electrode 5 to measure, the distance lis measured, and the resultant measurement is output. A display device 24 inputs the output of the sensor 20, and displays the value related to the eccentricity of the electron gun 9. Consequently, the eccentricity of the electron gun 9 can be measured at the accuracy of 1/100mm level with no contact, and the measuring time is also reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a device for measuring the eccentricity of the central axis of an electron gun.

[Conventional technology]

To explain an electron gun for a cathode ray tube as an example, as shown in FIG. Insulating supports 6# are held at predetermined intervals, and these are connected to the stem 8# via stem leads 7, forming an electron gun assembly 9 as a whole.

The electron gun assembly 9 having such a cloudy structure has an exhaust pipe 11, for example, so that the central axis 10 of the electron gun is always perpendicular to the bottom surface of the stem 8. The assembly must be such that eccentricity (hereinafter referred to as electron gun eccentricity) 12 does not occur, and in the above case, this eccentricity 12 is required to be suppressed to within 0.2 wm. This requirement is particularly strict for electron guns used in high-definition color cathode ray tubes, and if the eccentricity increases, the color purity characteristics of the color cathode ray tube will deteriorate, image quality will deteriorate, and the number of adjustments will increase. , there is a problem of reducing productivity.

Therefore, conventionally, as shown in FIG. 4, the exhaust pipe 11 of the electron gun assembly 9 is inserted into the base 13, and the upper surface of the base 13 is perpendicular to the reference plane while rotating the electron gun assembly 9 as appropriate. The distance between the electron gun 14 and the electrode 5 is measured visually or using a dial gauge, etc., and the eccentricity is adjusted using the flexible part of the electron gun structure 9, that is, the stem lead 7 part. .

[Problems that the invention attempts to solve]

However, according to this conventional measurement method,
Since many manual operations are required, it is difficult to obtain desired measurement accuracy. Generally, the tip of the electron gun η)
If we use a large cathode ray tube with a long distance to the phosphor surface, even if the eccentricity 12 of the central axis 10 increases by only 711), the positional deviation of the electron beam projected onto the phosphor surface will be large. Become,
This results in a decrease in color purity. For this reason, it is necessary to strictly suppress the eccentricity 12 within a range within which the positional deviation of the electron beam can be adjusted using other adjustment means, and a highly reliable measurement technique is required. It was requested to be implemented.

In addition, the conventional measurement method requires not only skill but also a lot of time, which reduces productivity.

SUMMARY OF THE INVENTION In view of the above-mentioned conventional problems, it is an object of the present invention to provide a measuring device that can efficiently measure the eccentricity of an electron gun with high precision and reliability.

[Means to solve the problem]

The above purpose is to provide an apparatus for measuring the eccentricity of an electron gun of an electron gun assembly having a plurality of electrodes, in which one end of the electron gun assembly is rotatably mounted and held on a lower base, which faces the electrode outer circumference. An electron gun eccentricity measuring device is provided, which has a measuring device that measures the distance from the measuring device in a non-contact manner, and a display device that displays numerical values related to the eccentricity of the electron gun from the output cuff 1) of the measuring device. This is achieved by providing

[Effect]

By using the above method, the numerical values related to the eccentricity of the electron gun can be measured and displayed automatically without contact, so that the measurement can be carried out quickly and with high accuracy and reliability. It becomes possible to measure a high degree of

〔Example〕

Hereinafter, one embodiment of the present invention will be explained starting from the first part. Components that are the same as those in FIG. 4 are given the same reference numerals and their explanations will be omitted.

In the figure, reference numeral 15 denotes a base, and the exhaust pipe 11 is arranged so that the stem 8 of the electron gun assembly 9 to be measured is brought into close contact with its base 16.
The holding portion 17f is rotatably mounted and held.

In addition, 18 is a sensor (hereinafter referred to as sensor 5) that measures the distance l from a predetermined position 19) to the outer peripheral surface of the electrode 5 at the tip in a non-contact manner. The measuring device includes a sensor 20 as shown in FIG.
8 frame 21#r:, SFC is attached, and this is moved to the horizontal movement mechanism 2
2G in the horizontal direction (Also, the vertical movement mechanism 23 allows the mount 21 to be freely moved in the vertical direction, so that the sensor 2° is appropriately approached and opposed to the outer peripheral surface of the electrode 5 to be measured. and measure the distance l,
It is configured to output the '61 setting.

Reference numeral 24 denotes a display device which inputs the output of the sensor 20 and displays numerical values related to the eccentricity of the electron gun.

Using the measuring device configured in this manner, first, the sensor 20 is placed facing the outer circumferential surface of the electrode 5, and the distance between the two is placed close to each other by about 0.1 to 0.5 W. Measuring the distance l while rotating the structure 9,
The output current is input to the display device 24f and displayed.

If the electron gun has an eccentricity 12 as shown in FIG. The degree of eccentricity of the electron gun can be checked, and from this, the stem lead 78 of the flexible portion of the electron gun structure 9 is adjusted to prevent eccentricity from occurring. Alternatively, the eccentricity of the electron gun may be calculated and displayed on the display device 24 from the output force of the sensor 20.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to measure the eccentricity of an electron gun with an accuracy of about 1/100 W without contacting the electrodes of the electron gun. Since the measurement time can be reduced by about 1 compared to the conventional method, the reliability of the electron gun characteristics is increased and the productivity of the electron gun assembly is improved.

[Brief explanation of the drawing]

FIG. 1 is a side view of a main part which is an embodiment of an electron gun eccentricity measuring device according to the present invention, FIG. 2 is a side view of a main part which is an embodiment of a measurement device according to the present invention, and FIG. FIG. 4, which is an explanatory diagram of the structure, is a side view of a main part of a conventional device for measuring the eccentricity of an electron gun. 8... Stem, 9... Electron gun structure, 10...
・Central axis, 11...Exhaust pipe, 12...
Eccentricity, 15... Base, 17... Holding part, 18...
Measuring bag fEffi, 20...Sensor 21...
- Frame, 22... Horizontal movement mechanism, 23... Vertical movement mechanism, 24... Display device. Diagram

Claims (1)

[Claims] 1. An apparatus for measuring the eccentricity of an electron gun of an electron gun assembly having a plurality of electrodes, comprising: a base on which one end of the electron gun assembly is rotatably mounted and held; An electron gun characterized by having a measuring device arranged to face each other and measuring the distance thereto without contact, and a display device displaying a numerical value related to the eccentricity of the electron gun from the output of the measuring device. Eccentricity measuring device. 2. The electron gun eccentricity measuring device according to claim 1, wherein the display device calculates and determines the eccentricity of the electron gun assembly from the output of the measuring device and displays the calculated value.