KR950003272Y1 - Gap distance mesuring device - Google Patents

Abstract

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Description

Thickness measuring device

1 is a cross-sectional view showing a conventional measuring device.

2 is a cross-sectional view showing a measuring device of the present invention.

3 is a plan view thereof.

Figure 4 is a perspective view of another embodiment of the measuring block of the present invention.

* Explanation of symbols for main parts of the drawings

1: substrate 2: support pole

4: Measurement block S: (vortex type) measuring sensor

MF: mask frame M: shadow mask

The present invention relates to the manufacture of color brown tubes, and more particularly to a measuring device for measuring the distance between the inner surface of the panel (panel) and the shadow mask (shadow mask).

Most of the color CRTs currently used are shadow mask methods, which induce electron beams emitted from electron guns to corresponding phosphors by means of color apertures formed in the shadow masks. That is, the holes for each color line of the shadow mask are electron beams emitted from the corresponding R, G, and B electron guns of the electron gun assembly in the R, G, and B phosphor stripes or dots forming one pixel. It will act to induce. In addition, the shadow mask serves as the original mask of the photolithography process of forming a fluorescent surface on the inner surface of the panel.

Accordingly, the distance between the shadow mask and the inner surface of the panel has great importance in determining the quality of the CRT such as the formation of the fluorescent surface and the image quality of the display image. For example, if the spacing is too large, the electron beam passing through the dichroic holes will cause not only the corresponding stripe but also the adjacent stripe to cause color bleeding, and if the spacing is too small, overall emission luminance will be reduced. Is degraded.

Therefore, in the manufacture of color CRTs, proper control of the distance between the shadow mask and the inner surface of the panel (commonly referred to as “quench” but referred to hereinafter as “PM interval” for clarity) is very important. By the way, such a PM interval is usually less than 10mm, so very small intervals, it was very difficult to put the measurement means in between.

Accordingly, this PM interval was conventionally measured by an air flow sensor (air flow sensor or air micrometer). This measuring method is a method of measuring the gap by forming a valve that opens and closes according to the size of the gap, and flows the airflow to measure the flow rate or flow rate.

An example thereof is shown in FIG. 1, in which, the measuring plate 11 is installed between the panel P and the shadow mask M at each position to be measured, respectively. The airflow sensor S 'is used to determine the area of the pipeline of the airflow supplied from the supply pipe 1 as the probe P' at the tip is pressed by the shadow mask M and / or the panel P. It is designed to change the flow rate or the flow rate of the airflow flowing through it by increasing and decreasing it. The PM interval is measured by measuring this with a flow rate or flow meter, not shown, and converting it into a distance value using a look-up table.

However, as the CRT becomes higher, the PM interval is reduced to improve the resolution. In the case of a CDT having a PM interval of only a few millimeters, the conventional measuring plate is inserted into the panel and the mask yarn. When it is difficult to perform the measurement, forcibly performing the measurement, there is a problem that deformation is caused in the shadow mask which is a porous sheet due to the elastic force of the probe and the repulsive force of the airflow. Accordingly, in the related art, fixed customs, which must precisely maintain PM intervals, have to endure the contradiction that they cannot measure and manage them. In addition, even if the measurement can be made, it is very cumbersome and time consuming because the measuring plate must be installed in the panel and the mask frame is recombined. Therefore, the whole inspection is impossible and the extraction inspection can be performed. There was no choice but to leave inadequate post-process input, and these ineligible products were found only in screen inspection after completion of the CRT, so there was a significant problem of loss of process and cost.

In order to solve such a conventional problem, the present inventors proposed a novel PM interval measuring method that solves the conventional problem by setting a reference plane and measuring the interval between the reference plane and the shadow mask to obtain the PM interval. This measuring method is described in a patent application (subsequent revision) filed on the same date as the present application, and an object of the present invention is to provide a measuring device that implements the principle of this measuring method.

In order to achieve this object, the PM interval measuring apparatus according to the present invention includes a plurality of support poles having a substrate and stud pins extending upwardly at a plurality of positions on the substrate and having a holder of a mask frame coupled thereon. And a measurement block arranged at a plurality of measurement positions on the substrate, and an eddy current type measurement sensor provided on the measurement block to measure a distance from the mask frame. .

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 and 3, the measuring device of the present invention has a stud pin (3) of the support pole (2) provided with a stud pin (3) at the tip of the flat substrate (1) ) Is coupled to the holder (H) of the mask frame (MF) to support the mask frame (MF) is arranged in the number and position corresponding to the holder (H) position. In the combined state, each measuring point position of the shadow mask M to be measured is provided with a measuring block 4 having a measuring sensor S, respectively. In the illustrated embodiment, the measurement position is such that the vertical, horizontal axial outward and diagonal outward and 9 positions of the center point of the shadow mask M are measured.

It is preferable that the height of each measuring block 4 is such that the measuring sensor S installed thereon has a zero point coinciding with the inner surface position of the panel at each measuring position. That is, as shown in FIG. 2, the zero points of the respective measuring sensors S are positioned on a virtual reference curve (indicated by a dashed line in the drawing) corresponding to the inner surface of the panel. In this case, the height of each measuring block 4 is equalized or the measuring sensors S are installed on the substrate 1 to subtract the corresponding value of the distance from each measuring position to the inner surface of the panel from the measured distance value. You can also make measurements in this way. In this case, however, the measurement process is cumbersome because the measurement process is cumbersome, and the measurement process is involved in the measurement error. Therefore, the measurement process is cumbersome and the measurement error may be generated due to the operation error. Would be desirable.

The measuring line S may be a sensor capable of measuring a small distance, for example, a pyroelectric sensor or a reflective sensor, but since the shadow mask M is a conductor, It is preferable that it is an eddy current sensor which detects the change of the eddy current according to a relative distance movement.

On the other hand, the measuring sensor (S) may be installed on a flat measuring block 4 having only a height difference as shown in FIGS. 2 and 3, but on the measuring block 4 'as shown in FIG. It can also be installed in. The measurement block 4 ′ shown in FIG. 4 protrudes a reference land 6 on at least one side of the measurement sensor S so that the extended surface of the upper surface corresponds to the inner surface of the panel. In the case of configuring the measuring block 4 'in this manner, a virtual curved surface extending the upper surface of the reference plane land 6 of each measuring block 4' corresponds to the inner surface of the panel to be used for setting the reference of the measurement. Can be.

The present invention of this configuration the measuring device is operated as follows.

When the holder H of the mask frame MF is coupled to the stud pin 3 of the support pole 2, the mask frame MF is supported on the measuring device of the present invention.

Next, when a driving voltage is applied to each of the measuring sensors S, each measuring sensor S outputs a potential value corresponding to a distance from the shadow mask M, and the potential value is applied to a display device (not shown) and measured. The interval is displayed numerically. This value is a numerical representation of the interval measured in accordance with the present principles. This value becomes the PM interval according to the present invention principle.

The measurement of the measurement sensor is applied to a microprocessor and compared with the set allowance to determine whether it is OK or to give an alarm when it is inadequate to be easily understood by those skilled in the art. It will be omitted.

As can be seen from the above, according to the present invention, it is not necessary to install the measuring device in a narrow space of the shadow mask and the panel company, so that it is not necessary to limit the thickness of the measuring device. Accordingly, the measuring means also does not need to be limited to the air flow sensor, and the process of converting the complicated air flow supply pipe or the flow rate into a thickness is unnecessary, thereby improving the measurement accuracy. In addition, since the measurement can be carried out continuously on a general-purpose measuring device, it is possible to guarantee the quality of the CRT by performing a full inspection as necessary.

In this way, the present invention has a great effect on improving the quality of color CRT, and in particular, it has the effect of remarkably improving the image display reliability of fixed customs such as CDT.

Claims (1)

Stud pins (3) to which the substrate (1) and the holder (H) of the mask frame (MF), which extends upward at a plurality of positions on the substrate (1) and is installed thereon and support the shadow mask (M), are coupled thereto. A plurality of support poles (2), a measurement block (4) arranged at a plurality of measurement positions on the substrate (1), and a mask frame (MF) provided on the measurement block (4). And an eddy current type measuring sensor (S) for measuring a distance between the inner surface of the panel and the shadow mask.