JP3221160B2 - 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 inspection apparatus for an electron gun used in a cathode ray tube.

[0002]

2. Description of the Related Art In a color cathode ray tube, three electron beams emitted from, for example, a unipotential type electron gun 10 as shown in FIG. Thus, a predetermined color is displayed. Since the phosphor screens of the three primary colors are very finely divided, the colors become abnormal unless each electron beam is irradiated to an accurate position. Therefore, it is necessary to accurately emit three electron beams from prescribed positions of the electron gun 10, respectively.

On the other hand, the electron gun 10 generates electrons for generating electrons.
A cathode arranged in one grid, and the generated electrons are combined into a flow bundle to form an electron beam, which is accelerated to a high speed, and a plurality of grids 11 to 17 and a plurality of electron beams for converging on a phosphor screen. It is composed of a plurality of components such as a conver (deflection plate) 18 for deflecting.

As described above, in order to accurately emit an electron beam from a prescribed position of the electron gun 10, the relative positional relationship between the grids 11 to 17 must be assembled particularly accurately. Therefore, after assembling, all the grids 11 to 17 are inserted into reference pins (not shown) and aligned,
The glass beading 19 is bonded over all the parts 11 to 18 so as to increase the assembly accuracy. The same applies to a bipotential type electron gun other than the unipotential type electron gun 10, for example.

[0005]

By the way, conventionally, the electron gun 10 is incorporated in a cathode ray tube without inspecting the characteristics of the electron gun 10 alone.
The performance test of the electron gun 10 is actually performed by projecting a test pattern or the like. However, in this case, there is a problem that the electron gun 10, which ultimately fails, must be once incorporated into the cathode ray tube, which wastes time and effort. Therefore, if a defective product can be detected before assembling the electron gun 10 into a cathode ray tube, it is not necessary to use unnecessary labor as in the related art.

As an inspection before assembling the electron gun 10 into a cathode ray tube, a method of detecting a relative positional relationship between the grids 11 to 17 can be considered. In other words, each grid 11-
If the mutual shift amounts of the electron guns 17 are within the allowable range, it can be estimated that the characteristics of the electron gun 10 are also good.

As a method of detecting the mutual positional relationship between the grids 11 to 17 as described above, a method of comparing the entire shape of the electron gun 10 with a reference shape can be considered. As a simple method of comparing the entire shape with the reference shape, for example, a method of inserting the electron gun 10 into a fitting jig (not shown) having a concave shape having the same shape as the contour of the electron gun 10 can be considered. In this method, the electron gun 10 that could not be inserted into the fitting jig is determined to be defective.

However, in this inspection method, each grid 11
It is not possible to numerically detect the relative positional relationships of No. to No. 17. In addition, since the fitting jig and the electron gun 10 come into contact with each other, in some cases, the electron gun 10 is forcibly inserted into the fitting jig, and an object that originally fails the test passes. Problems arise.

As a countermeasure against this, there is an inspection method in which the contour of the electron gun 10 is projected by a projector, and this is superimposed on a reference contour to detect a deviation between the two. However, this inspection method has poor measurement accuracy and There is a problem that it takes a long time to inspect one electron gun 10.

In view of the above, the present invention has been made to solve the above-mentioned problem, and proposes an electron gun inspection apparatus capable of accurately detecting the relative positional relationship of each part of the electron gun in a short time. Things.

[0011]

In order to solve the above-mentioned problems, according to the present invention, an image pickup means for picking up an image of an outer shape of an electron gun and an output of the image pickup means are analyzed to determine a relative positional relationship between respective parts of the electron gun. It is characterized by comprising analysis means for detecting and display means for displaying the analysis result of the analysis means.

[0012]

As shown in FIG. 1, when the electron gun 10 is inspected by the electron gun inspection apparatus 1, the electron gun 10 is placed on the measuring table 2.
Is mounted and an image is taken by the camera 3. The output of the camera 3 is supplied to a monitor 5 and a data analyzer 6. In the data analysis unit 6, the G1 grid 11 to the G5 grid 17 of the electron gun 10 are used.
Of each grid 11 to 17
Is calculated.

Then, as shown in FIG. 2, the external axes of all the grids 11 to 17 are displayed by aligning the central axis of the G3B grid 15 serving as the main lens with the reference axis 21. The shift amount 22 of the central axis of each of the grids 11 to 17 and the inclination 2
3 is displayed numerically. This makes it possible to accurately and easily detect a defective portion.

[0014]

Next, an embodiment of an inspection apparatus for an electron gun according to the present invention will be described in detail with reference to the drawings.

FIG. 1 shows the configuration of an electron gun inspection apparatus 1 according to the present invention. The inspection apparatus 1 for an electron gun includes an electron gun 10 on a measurement table 2 on which the electron gun 10 as shown in FIG.
Is arranged. The camera 3 can be moved laterally by the movable base 4, and thereby, it is possible to capture an image of the entire long electron gun 10.
The output of the camera 3 can be displayed on the monitor 5 as it is.

The output of the camera 3 is supplied to a data analyzer 6, where various analyzes are performed as described later. This analysis result is displayed on the monitor 7. Electron gun 10
Various data such as a measurement program and data analysis items are input from the keyboard 8. The components 2 to 8 described above are stably mounted on the base 9.

The data analyzer 6 performs edge detection on the grids 11 to 17 by performing fine line processing on the image supplied from the camera 3. Next, the central axis of each of the grids 11 to 17 is calculated from the detected edge, and the shift amount and the inclination with respect to the reference axis are calculated. The analysis result thus calculated is displayed on the monitor 7.

FIG. 2 shows a display example of the analysis result. In this example, the figures of the grids 11 to 17 are displayed on the reference axis 21 as shown in FIG. Here, the central axis of the G3B grid 15 serving as the main lens is aligned with the reference axis 21. This makes it possible to measure the correlation between the displacement of the other grids 11 to 13 and 16 to 17 with respect to the G3B grid 15 and the beam spot diameter. Also,
By utilizing this correlation, defective products can be easily detected.

Below the figure, the shift amount 22 of the central axis of each of the grids 11 to 17 with respect to the reference axis 21, that is, the shift amount and the inclination 23 are displayed numerically. The unit is μm. If the value of the shift amount 22 is negative, the reference axis 21
The position is shifted upward, and a positive value indicates that the position is shifted downward. Further, when the numerical value of the inclination 23 is minus, it indicates that it is inclined to the left, and when it is plus, it indicates that it is inclined to the right. Each grid 1
Outer diameters 24 and grid numbers 25 of 1 to 17 are displayed.
In addition, necessary items such as a tilt magnification 26 and a shift magnification 27 are displayed.

Furthermore, for example, if a figure or a numerical value of a portion deviated by more than an allowable value is displayed in a color different from that of another portion, it is possible to find a defective portion immediately. It is also possible to print out the displayed contents.

In the inspection apparatus 1 for an electron gun, since the content of the defect is displayed by a numerical value, it is easy to readjust the portion, thereby making it possible to reduce defective products.

In the above-described embodiment, the case where the unipotential type electron gun 10 is inspected has been described. However, the inspection apparatus 1 can inspect other types of electron guns such as the bipotential type in the same manner. It is.

[0023]

As described above, the present invention provides imaging means for imaging the outer shape of an electron gun, analysis means for analyzing the output of the imaging means to detect the relative positional relationship between the parts of the electron gun, and analysis means. And a display means for displaying the analysis result.

Therefore, according to the present invention, since it is possible to detect and display the relative positional relationship between the grids of the electron gun, it is possible to accurately and easily detect a defective portion. This can be determined at a glance. In addition, the inspection can be performed in a very short time because it is only necessary to image the electron gun.
Furthermore, displaying the analysis result as a numerical value has the effect that it is easy to readjust the defective part and obtain a satisfactory product.

[Brief description of the drawings]

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

FIG. 2 is a diagram illustrating a display example of an analysis result.

FIG. 3 is a configuration diagram of a unipotential type electron gun 10.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Inspection apparatus of electron gun 2 Measurement stand 3 Camera 4 Moving stand 5 Monitor for camera 6 Analysis part 7 Monitor for display of analysis result 8 Keyboard 9 Base 10 Electron gun 11 G1 grid 12 G2 grid 13 G3A grid 15 G3B grid 16 G4 grid 17 G5 Grid 18 Conver 19 Beading

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01J 9/42

Claims (2)

(57) [Claims] An imaging unit configured to image an outer shape of the electron gun; an analysis unit configured to analyze an output of the imaging unit to detect a relative positional relationship between components of the electron gun; and to display an analysis result of the analysis unit. An inspection apparatus for an electron gun, comprising: a display unit. 2. The inspection apparatus for an electron gun according to claim 1, wherein said analysis means numerically detects a relative positional relationship of each part of said electron gun.