JP2807116B2 - Electron gun inspection equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron gun inspection apparatus used for inspecting an electron gun contained in a cathode ray tube, for example.

[0002]

2. Description of the Related Art FIG. 5 is a schematic view of a conventional electron gun inspection apparatus, in which 1 is a cathode, 3 is a first electrode, 4 is a second electrode, 5 and 6 are third electrodes, With the electrodes, the cathode 1 is positioned on the bead glass 7 via the cathode support 2,
Further, the other electrodes 3 to 6 are directly positioned and held on the bead glass 7 so that the electron gun assembly 17 is held.
Is composed. An air micrometer 16 is connected to the measurement nozzle 8. The fixed holding portion 9 of the electron gun assembly is integrated with the measurement nozzle 8.

Next, the operation of the above configuration will be described with reference to FIG. The measurement nozzle 8 (fixed holding part 9) is inserted into the electron gun assembly 17. As shown in FIG. 6, the electron gun assembly 17 is held on the third electrode 5 side of the second electrode 4, and the measurement value of the air micrometer 16, that is, the distance from the tip 8 a of the measurement nozzle 8 to the cathode 1 is measured. Measure and inspect the distance (LK). This is the distance (L4) from the second electrode 4 to the cathode 1.
Means almost the same as measuring and inspecting.

[0004]

The cut-off voltage is negative.
An important characteristic of a cathode ray tube is that the cathode
Can not be measured without the activation step of the cathode
At the stage of the electron gun alone before being incorporated into the tube, cut
Measuring the off-electrode itself is currently available
Absent. To improve the production yield of cathode ray tubes,
Cut-off at the stage of the electron gun alone before being incorporated into the tube
Widespread inspection of dimensions that affect voltage
Have been. The conventional method is described in the above paragraph 0002,0003.
It is simple because it is called the G2-K method described above.
But there were many problems. Cuts described in paragraph 0021 below
When off regression predicted voltage value of the formula _{CoEc 2 = K * t / KφD} 3 * a (L1 + A) * (L3 -t + B) + C is partially differentiated by each electrode interval _{variable, 2CoEc 2 / 2L1 = K *} t / φD 3 * ( L3-t + B) 2CoEc ₂ / 2L3 = K * t / φD ³ * (L1 + A) Therefore, L3-t + B and L1 + A must be significantly different.
2CoEc ₂ / 2L1 and 2CoEc ₂ / 2L3
Conventional method of measuring L4 (LK) because there is no significant difference
The thickness and hole diameter of the first electrode and the thickness of the second electrode are constant
If this is the case, it is enough to inspect the interval L4 (LK)
Met. However, in recent years, the drive characteristics of the cathode have been improved.
In order to achieve this, 2CoEc ₂ / 2L
1: ₂ CoEc ₂ / 2L3 = 1: 2 to 1: 3
Is common. Therefore, L4 (LK) is constant.
But in other words, in the conventional inspection, it was OK
Also, if the distance between the first electrode and the second electrode is larger than the setting,
If so, problems such as cut-off failure in the cathode ray tube
there were. In practice, the thickness and hole diameter of the first electrode and the second electrode
Electrode thickness is not constant and varies with parts lot
In some cases, causing trouble. Again
Years, to improve the focus characteristics of the cathode ray tube
Contrivance is made to reduce the pore diameter of the first electrode on the one
That means is adopted. Air micrometer
Range of measurement is proportional to the square of the open end of the measurement nozzle.
High-definition type used for display devices such as personal computers
Measurement noise used in electron guns incorporated in cathode ray tubes
In air, the practical measurement of the air micrometer
The linear range is about 20 μm, and L4 (LK) should be set.
Smaller value, and relatively large deviation
If the measurement nozzle touches the cathode during inspection,
This is an extremely problematic situation (paragraph 0022).
In practice, there is a problem.
And consequently the cathode
There was a problem that the yield of the tube was low.

The present invention has been made to solve these problems.
The distance between the first electrode and the second cathode is a problem.
At least, the interval between the first electrode and the second electrode is larger than the set interval.
If it is misaligned, it may not be detected as defective.
To provide an electron gun inspection device capable of
The device is a high-definition type that cannot be inspected by conventional methods.
Can also be applied to inspection of electron guns incorporated in cathode ray tubes
It is a device and can be used for lot fluctuation of the thickness and hole diameter of the first electrode.
Provide a device that can prevent problems due to
The purpose is to do so.

[0006]

Means for Solving the Problems To achieve the above object,
In the electron gun inspection apparatus according to the present invention, the cathode, the first
The electrode, the second electrode and other electrodes are positioned
Means for fixing and holding the electron gun assembly, and the electron gun assembly
The electron beam passage holes of the first electrode and the second electrode of the
Nozzle that can move in and out, and this measurement nozzle
And a driving device for moving the electron gun assembly.
Means for measuring the distance between the first electrode and the second electrode, and the electron gun
Means for measuring the distance between the cathode and the first electrode of the assembly;
Measurements obtained by these measurement means, hole diameter and plate thickness of the first electrode
Using the lot representative values of
And a means for calculating.

[0007]

According to the electron gun inspection apparatus of the present invention,
The distance between the first electrode and the second electrode and the distance between the cathode and the
Measure the distance between one electrode and the distance between those measurements and the first electrode
Of the first electrode, the plate thickness and the hole diameter of the first electrode.
Cutoff regression expected voltage value using lot representative values
And perform the test using the expected cut-off regression voltage value.
Therefore, the inspection accuracy is improved.

[0008]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of an electron gun inspection apparatus according to one embodiment of the present invention, and FIG. 2 is a sectional view of an electron gun assembly.

In FIG. 1, 1 is a cathode, 3 is a first electrode,
4 is a second electrode; 5, 6 are third and fourth electrodes;
Is positioned on the bead glass 7 via the cathode support 2 and the other electrodes 3 to 6 are directly positioned and held on the bead glass 7 as shown in FIG. doing.

Reference numeral 9 denotes a fixed holding section for holding the electron gun assembly, and a cylindrical positioning shaft 9A for positioning the electron gun assembly 17 shown in FIG.
0 mounting flange 9B. Numeral 8 denotes a measurement nozzle, which is located in the cylindrical positioning shaft 9A, and whose tip is the electron beam passage hole 3 of the first electrode 3 and the second electrode 4 shown in FIG.
1 and 4a are configured to be movable in the direction of the arrow (X-Y) via the driving device 12 shown in FIG. An air micrometer 16 is connected to the measurement nozzle 8.

Reference numeral 10 denotes a micrometer, which is mounted on the mounting flange 9B of the fixed holding section 9 and to which an arithmetic unit 11 is connected. Reference numeral 13 denotes a light source, which is arranged on one side between the first electrode 3 and the second electrode 4.

Reference numeral 14 denotes an imaging device, which is arranged on one side opposite to the light source 13, and 15 denotes a monitor as an image display unit connected to the imaging device 14.

Next, the operation of the above configuration will be described. The positioning shaft 9 of the fixed holding part 9 is attached to the electron gun assembly 17.
By inserting A, the electron gun assembly 17 is positioned and fixedly held by the fixed holding portion 9.

In this state, the measurement noise is
The chisel 8 is moved in the direction of the arrow X, and the tip of the measuring nozzle 8 is moved.
8a into the electron beam passage hole 4a of the second electrode 4 shown in FIG.
insert.

Next, the measuring nozzle 8 is moved in the directions of arrows XY.
The light from the light source 13 is moved to the second position on the monitor 15.
The silhouette 17 of the tip 8a of the measurement nozzle 8 is made slightly visible from an image 19 of the electron beam passage hole 4a formed by reflection on the surface of the electrode 4 as shown in FIG.

Next, the measuring nozzle 8 is moved in the direction of arrow X, and the distance (L0) between the tip 17a of the silhouette 17 of the measuring nozzle 8 and the silhouette 18 of the first electrode 3 becomes zero, ie, FIG. As specified in 3, the distance (L1) between the opposing surfaces of the first electrode 3 and the second electrode 4 is measured by the micrometer 10, and the measurement data is applied to the arithmetic unit 11.

Subsequently, the measurement nozzle 8 is moved in the direction of the arrow X via the driving device 12, and the distance until the measured value of the air micrometer 16 reaches a predetermined value (n), ie, FIG. 3, the distance between the facing surfaces of the cathode 1 and the first electrode 3 (L2)
The value (L) obtained by adding the plate thickness (t) and subtracting the constant value (m)
3) is measured by the micrometer 10 and the measured data is applied to the arithmetic unit 11.

The constant value (m) means the tip 8a of the measurement nozzle when the value of the air micrometer 16 becomes (n).
And the distance between the cathode 1 and the end face 1a of the cathode 1, which may be measured once.

An expected cutoff regression voltage value (CoEc2) is calculated by the arithmetic unit 11 from the above two measurement data, the plate thickness (t) of the first electrode 3 and the hole diameter (φD),
Inspect cut-off characteristics.

The thickness (t) of the first electrode 3 and the hole diameter (φ
Since it is difficult to measure D) individually, in practice, sampling is performed for each production lot of the first electrode 3, an average value is obtained, and the electron gun assembly 17 using that lot is inspected. , Use that average. The expected cut-off regression voltage value is represented by the following equation.

CoEc ₂ = K * t / φD ＾ 3 * (L1 + A) * (L3-t + B) + CK K, A, B, and C are constants that vary depending on the structure of the electron gun.
Determined by experiment or numerical calculation (simulation)
You.

When the diameter of the electron beam passage holes 3a, 4a of the first electrode 3 or the second electrode 4 is reduced, the diameter of the measurement nozzle 8 is also reduced, so that the sensitivity range (measurement range) of the air micrometer 16 is reduced. The conventional inspection method has a disadvantage that it is not practical for the electron gun assembly 17 in which the diameter of the electron beam passage holes 3a and 4a of the first electrode 3 or the second electrode 4 is small. In this inspection method, since the measurement nozzle 8 can be moved in the direction of the arrow (XY) in FIG. 1, even if the diameter of the electron beam passage holes 3a, 4a of the first electrode 3 or the second electrode 4 is small, sufficient inspection can be performed. It is possible.

[0023]

As described above, according to the present invention, the electronic
The distance between the first electrode and the second electrode of the gun assembly and the distance between the cathode and the first electrode.
Measure the distance between the electrodes, and compare these measurements with the plate of the first electrode.
With lots representative value of the thickness and pore size, cutoff regression predicted
Calculate the voltage value and use this voltage value for inspection.
, So that the cathode ray tube is
Inspection at the stage before installation, expected cut-off
Can be detected with high accuracy and can be removed,
The yield of the cathode ray tube can be increased. Also high definition
The diameter of the hole of the first electrode used in the
There is an effect that the inspection can be sufficiently performed even with a sub gun.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an electron gun inspection apparatus according to an embodiment of the present invention.

FIG. 2 is a sectional view of an electron gun assembly.

FIG. 3 is an enlarged sectional view of a main part for explaining an inspection operation.

FIG. 4 is a video diagram on a monitor.

FIG. 5 is a schematic view of a conventional electron gun inspection device.

FIG. 6 is an enlarged sectional view of a main part for describing a conventional inspection operation.

[Explanation of symbols]

1 cathode, 3 first electrode, 4 second electrode, 8 measuring nozzle, 9 fixed holder, 10 micrometer, 11 arithmetic unit, 16 air micrometer.

Claims (1)

(57) [Claims] 1. A means for fixing and holding an electron gun assembly in which a cathode, a first electrode, a second electrode and other electrodes are positioned, and respective electrons of a first electrode and a second electrode of the electron gun assembly. A measuring nozzle whose tip is movable in and out of the beam passage hole, a driving device for moving the measuring nozzle, and means for measuring a distance between the first electrode and the second electrode of the electron gun assembly; Means for measuring the distance between the cathode and the first electrode of the electron gun assembly, and expected cut-off regression voltage values using the measured values obtained by those measuring means and representative values of the hole diameter and plate thickness of the first electrode An electron gun inspection apparatus comprising: means for calculating