JPH0935639A - Measuring device for shadow mask structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a measuring device for a shadow mask of simple constitution which can perform measurement of a low Q value or precise measurement by detecting the electric continuity by the contact between an electric contact ascending and descending by a piezoelectric element and a shadow mask, and measuring the Q value from the displacement of the piezoelectric element. SOLUTION: This is a measuring device for a shadow mask structure 20, which measures the interval dimension Q value between the inner face of a reference panel 7 and a shadow mask 1 by mounting the shadow mask structure 20 on the reference panel 7. A control power source 14 made of a drive power source 11 and a control circuit 13 measures the Q value from the displacement of piezoelectric elements, using electric contacts 10, which are driven to ascend and descend by the piezoelectric elements 9, being arranged on the inner face of the reference panel 7, and a circuit 12 for detecting electric continuity between the electric contacts 10 and the shadow mask 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a measuring apparatus used for assembling a color cathode ray tube, and more particularly, to a distance dimension (hereinafter referred to as Q value) between a shadow mask and a panel before mounting the shadow mask structure on the panel. The present invention relates to a measuring device used for measuring.

[0002]

2. Description of the Related Art Assembly of a panel portion of a conventional shadow mask type color cathode ray tube is disclosed in JP-A-60-221930. That is, as shown in FIG. 2, a skirt portion 1a formed by raising the peripheral portion of the shadow mask 1, a flange portion 2a having a substantially rectangular frame shape, and a side wall raised at a substantially right angle to the outer edge of the flange portion 2a. The shadow mask structure 20 assembled by welding the frame 2 composed of the portion 2b and the frame 2 is attached to the panel pin 5 planted on the inner wall of the panel 4 via the spring 3 planted on the side wall portion 2b of the frame 2. Is being done.

A space dimension 6 from the inner surface of the panel 4 to the shadow mask 1 in this assembly is generally called a Q value, and is important for forming phosphor layers of three colors and selectively transmitting an electron beam for image display. Since it has different dimensions, it must be uniform over the entire inner surface of the panel 4. Therefore, prior to this assembly, in order to check whether or not the shadow mask structure 20 is formed as designed, it is confirmed that the Q value is within a predetermined range by a measuring device using an air micrometer. As shown in FIG. 3, the device used for this measurement is composed of measuring heads 8 and 8 of an air micrometer (not shown) attached to a predetermined position of the reference panel 7, and the air micrometer is used as a reference. The distance (Q value) between the shadow mask 1 attached to the panel 7 and the surface of the panel 7 is measured.

[0004]

However, in the above-mentioned measuring device using the air micrometer, if the target predetermined Q value is different from the set value by 0.3 mm or more,
There is a problem in that the tip of the measuring head 8 of the air micrometer and the surface of the shadow mask 1 are too far apart from each other, so that calibration is necessary and a skilled worker having calibration skill is required. Further, it is difficult to measure a low Q value of 0.01 mm or less, and when multiple measurement heads 8 are used for simultaneous multi-point measurement, air supply piping is congested or the supply pressure fluctuates. There was also a problem.

In order to solve the above-mentioned problems, an object of the present invention is to detect conduction due to contact between a shadow mask and an electric contact that is moved up and down by a piezoelectric element, and measure the Q value from the amount of displacement of the piezoelectric element. Accordingly, it is an object of the present invention to provide a shadow mask structure measuring apparatus having a simple structure that can easily measure a low Q value and a precise measurement.

[0006]

SUMMARY OF THE INVENTION The present invention is a shadow mask structure measuring apparatus for mounting a shadow mask structure on a reference panel and measuring a distance dimension (Q value) between an inner surface of the panel and the shadow mask. An electric contact arranged on the inner surface of the panel and driven up and down by a piezoelectric element, means for detecting conduction between the electric contact and the shadow mask, and a control power supply for measuring the Q value from the displacement amount of the piezoelectric element. An apparatus for measuring a shadow mask structure provided is provided. Also,
It is desirable that the piezoelectric element is a laminated piezoelectric element, the electrical contacts are provided at a plurality of positions on the upper surface of the reference panel, and the displacement amount of each piezoelectric element can be individually measured.

[0007]

According to the above construction, since the piezoelectric element is accurately displaced in proportion to the applied voltage, the Q value is measured from the displacement amount conducted to the shadow mask by using the electrical contact which is vertically displaced by the piezoelectric element. As a result, low Q value measurement and precise measurement can be easily performed, and a skilled worker such as calibration is unnecessary. Further, the measuring element can be downsized, and a member such as an air tube for supplying air is not required, which facilitates simultaneous measurement at multiple points.
Furthermore, if a laminated piezoelectric element is used, the response of the displacement to the applied voltage can be improved. Therefore, by stopping the voltage rise at the same time as the contact between the electrical contact and the shadow mask, the deformation of the shadow mask due to the inertia of the displacement, etc. It is possible to prevent the application of stress and increase the amount of displacement easily due to the multistage structure.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. The same parts as those in the conventional example are denoted by the same reference numerals, and description thereof will be omitted. As shown in FIG. 1, a shadow mask structure measuring apparatus according to an embodiment of the present invention has a plurality of laminated piezoelectric elements 9 and 9 mounted at predetermined positions on a reference panel 7, and shadows of the piezoelectric elements 9 and 9 are attached. Electrical contacts 10, 10 are provided on the upper surface facing the mask 1. Then, the piezoelectric element 9,
A driving voltage is individually supplied to each of 9 from the driving power source 11, the electrical contact 10 is connected to the continuity detecting circuit 12, and the driving power source 11 is controlled by the signal from the continuity detecting circuit 12 via the control circuit 13. The control power supply 14 is configured so.

The measurement of the shadow mask structure by this measuring device is performed as follows. That is, the shadow mask structure 20 is attached to the reference panel 7, and the panel pin 5 is attached.
Attached to the shadow mask structure 2 via the spring 3
0 and the continuity detection circuit 12. And the piezoelectric element 9
A drive voltage is supplied from the drive power source 11 for each electric contact 10
When the electric contact 10 comes into contact with the shadow mask 1, conduction is detected by the conduction detection circuit 12, and the drive voltage to the piezoelectric element 9 is released via the control circuit 13, and the displacement amount is changed from the voltage value. Is measured. In this way, the Q values at a plurality of predetermined positions are measured, and if the Q values are within the predetermined range, the shadow mask structure 20
Is used as a good product, and if it is out of a predetermined range, it is removed as a defect and repaired. According to this embodiment, the piezoelectric element 9 is accurately displaced in proportion to the applied voltage. Therefore, by measuring the Q value from the displacement amount of the piezoelectric element 9 which is electrically connected to the shadow mask 1, it is possible to measure a low Q value or to perform precise measurement. The measurement can be done easily, and skilled operators such as calibration are not required. Further, the measuring element can be downsized, and a member such as an air tube for supplying air is not required, which facilitates simultaneous measurement at multiple points.

Further, since the laminated piezoelectric element is used, the responsiveness of the displacement to the applied voltage can be improved, and by stopping the rise of the voltage at the same time as the contact between the electric contact 10 and the shadow mask 1, the inertia of the displacement can be improved. It is possible to prevent the application of stress such as deformation of the shadow mask 1 due to the above, and it is also possible to easily increase the displacement amount due to the multi-stage. Although the Q value measuring device for the shadow mask structure using the laminated piezoelectric element has been described above, the present invention is not limited to the above-mentioned example. For example, if a bimorph type piezoelectric element is used, the responsiveness is slightly lowered. However, since the displacement amount can be increased, it is suitable for measuring a shadow mask structure having a relatively large Q value.

[0011]

According to the present invention, since the piezoelectric element is accurately displaced in proportion to the applied voltage, the Q value can be calculated from the displacement amount conducted to the shadow mask by using the electric contact which is vertically displaced by the piezoelectric element. By performing the measurement, low Q value measurement and precise measurement can be easily performed, and a skilled worker for calibration or the like becomes unnecessary. Further, the measuring element can be downsized, and a member such as an air tube for supplying air is not required, which facilitates simultaneous measurement at multiple points. Furthermore, if a laminated piezoelectric element is used, the response of the displacement to the applied voltage can be improved. Therefore, by stopping the voltage rise at the same time as the contact between the electrical contact and the shadow mask, the deformation of the shadow mask due to the inertia of the displacement, etc. It is possible to prevent the application of stress and increase the amount of displacement easily due to the multistage structure.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a shadow mask structure measuring apparatus according to an embodiment of the present invention.

FIG. 2 is a sectional view of an essential part showing assembly of a shadow mask structure into a panel.

FIG. 3 is a sectional view of a conventional shadow mask structure measuring apparatus.

[Explanation of symbols]

 1 Shadow Mask 3 Spring 5 Panel Pin 7 Reference Panel 9 Piezoelectric Element 10 Electrical Contact 11 Drive Power Supply 12 Continuity Detection Circuit (Means for Detecting Continuity) 13 Control Circuit 14 Control Power Supply 20 Shadow Mask Structure

Claims (3)

[Claims] 1. A shadow mask structure measuring device for mounting a shadow mask structure on a reference panel to measure a distance between an inner surface of the panel and the shadow mask. Measurement of a shadow mask structure comprising: an electric contact to be driven; a means for detecting conduction between the electric contact and the shadow mask; and a control power supply for measuring the distance dimension from the displacement amount of the piezoelectric element. apparatus. 2. The shadow mask structure measuring apparatus according to claim 1, wherein the piezoelectric element is a laminated piezoelectric element. 3. The shadow according to claim 1, wherein the electrical contacts are provided at a plurality of locations on the inner surface of the reference panel, and a control power source is provided which can individually measure the displacement amount of each piezoelectric element. Measuring device for mask structure.