JPS6041416B2 - Processing method of data for deflection yoke magnetic field distribution inspection - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a data processing method suitable for inspecting horizontal coils and vertical coils, which are the main components of a TV deflection yoke.

Inspection of deflection yokes for color VTs was performed using an image inspection method on the completed product by combining the main components, horizontal coils, and as a result, there was no evaluation method for the coils alone, and coil manufacturing technology was lagging behind.

Therefore, as a method to evaluate the quality of a single coil, we developed a ``single coil inspection method'' that applies the measurement of magnetic field distribution, but it is still in its infancy and requires a large amount of time to process data using experimental equipment. Analog data processing is first done by calibrating the sensor or by making hardware corrections in the input circuit, but when there are a large number of sensors, the mounting position and angle greatly affect the output, especially when it comes to magnetic field measurement sensors. There is no calibration method for the sensor alone.

In other words, in a device equipped with a large number of magnetic field measurement sensors, it is difficult to calibrate each sensor individually or to correct it using the input circuit. Corrections on the circuit are due to component variations and measurement conditions (including environment)
etc. are accumulated, and it becomes a problem as to what should be used as the correction standard. Conventionally, there is a method of measuring the magnetic field distribution while moving one sensor in parallel, but it takes time and is inefficient when the number of measurement points increases.

Additionally, high accuracy is required for the sensor's travel mechanism. SUMMARY OF THE INVENTION An object of the present invention is to provide a method for processing data for testing deflection yoke magnetic field distribution, which improves testing accuracy by accurately measuring the magnetic field distribution of a deflection yoke coil.

The gist of the present invention is based on the relative relationship between the magnetic field distribution determined by moving a single sensor relative to the standard deflection yoke and the magnetic field distribution determined by the plurality of magnetic field measurement sensors relative to the standard deflection yoke. - Correction coefficients are set for all of the plurality of magnetic field distribution measuring sensors, and the measured values are digitally processed in accordance with the correction coefficients.

Hereinafter, the present invention will be explained in detail with reference to the drawings. The differences in the inspection of horizontal coils for deflection yokes are the direction of the magnetic field and the value of the current flowing through the coils, and there are no other differences.Here, a vertical coil was taken up as an example.

As shown in FIG. 1, the vertical coil of the deflection yoke is composed of two coils 1 and IA wound around ferrite cores 2 and 2A.

As shown in Figures 2 and 3, the measurement points 3 for magnetic field distribution are 12 points A, ~A, 2, B~B2, C, and 12 points on cross sections A, B, C, and D perpendicular to the central axis of the coil, respectively. ~C,2,D,
~D2, and the intervals were set at 30 degrees on the circumference along the inner surface of the coil like a clock face. In addition, the detection direction of the sensor was all set to one direction. FIG. 4 shows a measurement jig in which magnetic field sensors are installed at the measurement points. FIG. 5 shows a coil unit inspection device used in an embodiment of the present invention. In FIG. 4, the magnetic field measurement vulgar 4 has 12 sensors 5, 6, 7, and 8 attached to each of the cross sections A, B, C, and D.

It is positioned and fixed in each sensor embedding hole 10 to obtain correct detection accuracy. Lead wires 9 of each sensor are led out through lead wire holes. The coil unit inspection device shown in FIG. 5 includes a base 12, a main body 13, a vertical shaft 14, a positioning hole 15, a positioning pin, a plate 17,
Holding pins 18, 18A, positioning pin 19, stopper 20, clamp cam 21, handle 22, bolt 23,
It consists of a lead wire 24, a terminal box 25, a cable 26, a control section 27 that automatically processes measurement data, a power source 28 that supplies electricity to the coil 1 and IA, and the measurement jig 4 shown in FIG.

The measuring coil is positioned by the handle 22 and the positioning knife 19 and placed on the clamp cam 21.

During measurement, the vertical shaft 14 moves downward to position the measuring jig 4 on the measuring coil, and the coil 1 and IA are supplied with electricity from the power source 28 to measure the magnetic field distribution. The problem with the above configuration is that the quality of the 48 magnetic field sensors is greatly affected by the mechanical positional accuracy of the 48 magnetic field sensors attached to the harness, especially by the angle inclination with respect to the detection direction.

Therefore, using a standard vertical coil, the data measured while mechanically moving the measurement points in parallel with one magnetic field sensor, and the data of 4 milk solids measured using the same coil and a single coil inspection device. The data were compared and 48 correction coefficients were determined. Furthermore, while looking at the symmetry on the cross section, 4
In order to be able to three-dimensionally process the data of the three cross sections A, B, C, and D, one point on each cross section was determined as a reference point, and this correction coefficient was set to "1". In this embodiment, the arrangement is the same as that of a clock face, and A, B, C, and D among the four cross sections are used as reference points. Next, how to obtain the correction coefficient will be explained.

First, a magnetic field distribution is determined at each of 48 points using one magnetic field sensor for a standard vertical coil. The results are shown in Table 1 below. Table 1 On the other hand, measurements were taken at 48 points on the standard vertical coil using a 4-needle sensor using the measurement positions shown in FIG.

The results are shown in Table 2. Table 2 Next, using Table 1, calculate the in Table 2. Ru.

This Sameshomanho uses the Samesho value for each cross section as ZAi, Sakazukii, Z
When Ci, ZDj (where i=1, 2...12), it is calculated using the following calculation formula. Table 3 shows the shark positive values determined by this calculation formula.

Table 3 Next, based on the shark positive values obtained in Table 3, determine the correction coefficient of the measuring device.

This correction coefficient is calculated for each cross section by RAJ, RBi, RCi, R
Assuming Di, the correction coefficient is calculated using the following calculation formula. Table 4 shows the correction coefficient values obtained by this calculation formula.

Table 4 The units in Tables 1 to 4 above are mV.

In addition, since the reference points are A,, B, C,, D, RA
, =RB, =RC, =RD, =1. By using the correction coefficients shown in Table 4, data A,...
B,C,,D. It is possible to obtain data in which the variations of the 48 sensors are corrected using the reference value. Figure 6 shows an example of the magnetic field distribution of a vertical coil measured by a coil unit inspection device.

In the figure, the X-axis and Y-axis represent the magnetic flux density, and the scale increases toward the center, and cross sections A and B move from the outside to the center.
, C, and D are shown. A block diagram for automatically processing these data is shown in FIG. In the figure, 48 pieces of data enter the analog multiplexer 29 and are processed by the timing controller 30 as data A,, A2..., D.
, 2 are sequentially sent to the amplifier 31 and the A/D converter 32, and then processed by the correction calculator 34 in association with correction coefficients stored in the ROM 33 in advance. The corrected data is sent via the video RAM 35 to the image display 36 (
(CRT display). At the same time, the unbalance amount of the magnetic field distribution can be calculated through the calculator 37 and printed out. Note that the blocks with diagonal lines are processed by a microcomputer. The data processing circuit consists of one amplifier 31 and one A/○ converter 32 so that the variations in circuit parts are accumulated in the data, and processes the data of four needles under the same conditions, improving the data processing accuracy. Improvements were made and the circuit was simplified. In the above embodiment, the correction coefficients are stored in the ROM 33 in advance, but it is also possible to store them through online processing.

Further, although the reference points are A, B, C, D, other reference points may be set. It is difficult to handle and calibrate a sensor, such as a magnetic field sensor, whose output changes significantly depending on the detection position and angle in the magnetic field.

When measuring using multiple sensors as in the present invention,
The amount of variation in the sensor output must be corrected or adjusted individually using a circuit, which poses problems in how to set standards and in reproducibility. The present invention aims to solve these problems and improve inspection accuracy and reliability. Automation also speeds up inspection and allows for application to mass production sites.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a vertical coil for a deflection yoke, which is the subject of an embodiment of the present invention, Fig. 2 is a side view showing an example of the magnetic field distribution measurement points of the vertical coil, and Fig. 3 is a magnetic field distribution of the vertical coil. A plan view showing an example of a measurement point, FIG. 4 is a cross-sectional view of a measuring device in which a magnetic field sensor of an embodiment is embedded, FIG. 5 is a perspective view of a single coil inspection device of an embodiment, and FIG. 6 is an embodiment. FIG. 7 is a block diagram of the data processing circuit of the embodiment. 1, IA... Coil, 2, 2A... Core, 5, 6, 7,
8...Sensor, 33...Correction coefficient ROM, 34...
...Correction calculator. Oh Madara O 2 Madara Boogie 3 Figure O 4 Figure O S Figure Oru Kaede Sai Figure 7

Claims (1)

[Claims] 1. Measuring the magnetic field distribution of the deflection yoke coil Deflection yoke coil magnetic field distribution inspection data obtained by measuring the magnetic field distribution of the deflection yoke coil using a plurality of magnetic field measurement sensors arranged around each other, and digitally processing the measured values. In the processing method, the relative relationship between the magnetic field distribution obtained by moving a single sensor relative to the standard deflection yoke and the magnetic field distribution obtained by the plurality of magnetic field measurement sensors relative to the standard deflection yoke is also determined. First, set a unique correction coefficient for each of the plurality of magnetic field measurement sensors mentioned above,
A method of processing data for a deflection yoke magnetic field distribution inspection, comprising: correcting measured values from the plurality of magnetic field measurement sensors using the correction coefficient during digital processing.