JPS6321724A - Crt landing measuring instrument - Google Patents

Abstract

PURPOSE:To make it possible to correctly find an area of the luminous part of a phosphor and a landing position as well by converting an optical image from a microscope into an electric signal by a camera followed by image processing of said signal. CONSTITUTION:Firstly, a green television signal is generated in the signal generation part to make a phosphor luminescent; a microscope 1 is focused; a current is made to flow through a forced magnetic field impression coil 2 by the magnetic field control part 7; an electron beam is swung to the left at first for obtaining a luminous part 10 for the phosphor 9. Said optical image is converted into an electric signal by a camera 3 to be received by the image processing part 4 and the operation part 5 computes an area of the calculation object part 12 inside an area caluculation frame 11, whose width is larger than that of the phosphor, when the area is divided by the londitudinal length the mean transverse length is found in which the formal irregularity of the luminous part 10 is dissolved. Next, the current is made to flow in the opposite direction to that of before to swing the electron beam to the right and the areal calculation of the caluculation object part 14 inside the area calculation frame 11 is performed to find the mean transverse length. From the half of the difference between the two results inlength, a state of the electron beam landing can be found.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a CRT landing measuring instrument that can be used to measure CRT landing in a CRT manufacturing process or in a color television manufacturing process. Technology A conventional CRT landing measuring device had a structure as shown in FIG. That is, a forced magnetic field applying coil 22 is attached to the microscope 21, and the forced magnetic field applying coil 22 is connected to a DC power source 24 through a polarity changeover switch 23.

At the time of measurement, as shown in FIG. 4, first place the microscope 21 on the point to be measured on the tube surface 31 of the CRT to be measured, focus it, and push the polarity changeover switch 23 shown in FIG. 1 in the downward direction. A forced magnetic field is applied downwardly from above to the CRT tube surface 31 shown in FIG. 4, and the electron beam is intentionally swung to the left to obtain the light emission @11 of the phosphor 33 shown in FIG. 5. Next, the magnetic selector switch 23 shown in FIG. 3 is pushed in one direction, a forced magnetic field is applied from below to the top of the CRT tube surface 31 shown in FIG. 4, and the electron beam is intentionally swung to the right. Obtain phosphor 330 luminous chant g2 like this.

Half of this difference is due to the landing state of the Reiko beam on the phosphor 33 as shown in FIG. 5C. Using the formula, landing (l rd, 12-((1+-1
2) It is determined by X1/2, and if the landing l is positive, then the landing is to the right, and if it is negative, the landing is to the left.

Problems to be Solved by the Invention However, the light emission of the phosphor is actually very uneven, like the light emitting part 41 in Figure 6&, especially the part 42 that should be the shadow of the Yado mask, and it is difficult to read where it is. Or it was difficult. Also, as shown in Figure 6, the boundary 43 is not clear, but a portion 44 that gradually becomes brighter.
There is a width metal from the part 46 that does not emit light.

Furthermore, there was a problem that the possible reading accuracy was limited by the magnification of the microscope 21.

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the present invention seeks to provide a complete CRT landing measuring device that can accurately determine the area of the light-emitting portion of the phosphor and, by extension, the landing position.

Means for Solving the Problems The CRT landing measuring instrument according to the present invention converts an optical image of a light emitting part of a phosphor based on electron beams polarized in opposite directions into an electrical signal using a camera equipped with a microscope, and Means for inputting a signal and averaging the uneven portions of the light emitting part to obtain the average lateral dimension, the lateral dimension of the light emitting part obtained when the electron beam is deflected in one direction, and the Kameko beam. The present invention is characterized in that it is completely equipped with means for determining the landing from the difference in the lateral dimension of the light emitting part obtained when the light emitting part is deflected in the other direction.

action The effect of this technical means is as follows.

In other words, the optical image from the microscope is converted into an electrical signal by a camera, and the signal is image-processed to extract the boundary and average the areas with severe irregularities to obtain the emission width.
This allows the area of the light-emitting portion to be determined accurately.

Embodiment Hereinafter, one embodiment of the present invention will be described based on all the attached drawings.

In FIG. 1, reference numeral 1 denotes a microscope, to which a forced magnetic field applying coil 2 is attached.

The focus of the microscope 2 can be adjusted by looking at the display section 6.

An appropriate optical image of the CRT tube surface obtained through the microscope 2 is converted into an electrical signal by a camera 3. The image processing unit 4 receives the signal and performs a cooperative operation with the calculation unit 5. Reference numeral 7 denotes a magnetic field control unit that can control the generation of a magnetic field in order to obtain landing.

8 is a signal generating section that generates red, blue, and green television signals. 9 is a phosphor on the surface of the CRT tube.

Next, the operation of the configuration of this embodiment will be explained. First, a green television signal is generated from the signal generator 8, causing the green phosphor to emit light. Therefore, the microscope 1 is attached to the part of the CRT to be measured that is to be measured, and the display unit 6 is focused.

A current Rk is applied from the magnetic field side (end) part 7 to the forced magnetic field applying coil 2, and the electron beam is first swung to the left, so that the light emitting part 1o shown in FIG. The optical image is converted into an electrical signal by the camera 3 and received by the image processing section 4. The calculation section 6 exchanges signals and data with the image processing section 4, and calculates the area of the calculation target section 12 within the area calculation frame 11 whose horizontal corners are wider than those of the phosphor 9. In this case, the width of the area calculation frame 11 is set to approximately the center of the black stripe portion. Since the length of the area calculation frame 11 in the vertical direction is constant, by dividing the area calculated earlier by the length in the vertical direction, the average horizontal length that eliminates the irregular shape of the light emitting part 1o can be found. .

Similarly, a current is passed from the magnetic field suppressor 7 to the forced magnetic field applying coil 2 in the opposite direction to the previous direction to swing the electron beam to the right. At that time, the light emitting part 13 becomes as shown in Figure 2, and the area calculation frame 11
The area of the calculation target section 140 within the area is calculated in the same manner as above, and the average horizontal length is determined.

Half of the difference between these two determined lengths determines the landing state of the electron beam, that is, the landing. When the difference is calculated, it will be a positive or negative value, and the sign of the difference will depend on the direction in which the landing deviates from the left and right with respect to the center of the phosphor 9.

As a result of the above, for example, by displaying the landing direction and number 1 on the entire display section 6, the landing can be easily measured.

Furthermore, as can be seen from the above description, in the conventional example, it is difficult to delicately align the microscope 1 in order to obtain the calculation target part of the enlarged optical image.

Therefore, in this configuration, the electric signal of the enlarged optical image is used, and a search function is provided to set the optimum part as the calculation target part 12 at the stage of image processing, and the area calculation frame 11 is set to the optimum part. Conventionally, landing has been evaluated only for green images, but in this configuration, a signal generation section 8 is built in, and a level control means is provided in the image processing section 4 to suit image processing. Landing can also be easily measured on video.

In this embodiment, the display unit 6 displays the processed optical image, the landing direction, and numerical values.

Effects of the Invention The present invention measures landing fully automatically, with high accuracy (0.1 micron resolution), and measures the top and bottom of landing,
Measurements can be made in the left and right directions.

Moreover, the following effects are also produced.

That is, the present invention is easy to operate because it has a function of automatically determining the necessary portion without having to delicately attach the microscope to the portion to be measured.

Furthermore, it has become possible to measure red and blue images, which was previously impossible due to the inconvenience of visual measurement using a microscope.

In addition, as an applied method, it has the advantage of being able to be measured repeatedly, making it easy to grasp all temporal changes in landing.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a CRT landing measuring instrument according to an embodiment of the present invention, Fig. 2 a and b are diagrams for explaining the operation of the measuring instrument, and Fig. 3 is a configuration of a conventional CRT landing measuring instrument. Figure 4 is a perspective view showing how the microscope is used, and Figures 5a and 5b. C is a diagram for explaining the function of the conventional example, and FIG. 6a. b is a diagram for explaining the problems of the conventional example. 1...Microscope, 2...Forced magnetic field application coil, 3...Camera, 4...Image processing unit, 6...Computation unit , 6...display section, 7
. . . Magnetic field sub-section, 8 . . . Signal generation section. Name of agent: Patent attorney Toshio Nakao and 1 other person/-
--Grudge to Tsubasa) Men 2--1 Forced surface Liaokai attack Locoil 3- Camera 4- Image processing unit 5- Calculation section 6- Display section 7-1 leakage control wholesale B-, main part of the main part Fig. 1 (cL) c'b) 9-Firefly 23--Unipolar 7, Masakiri scissors/Tute 2□ 24-'i Figure 6

Claims (2)

[Claims] (1) A means for converting an optical image of a light-emitting part of a phosphor based on electron beams polarized in opposite directions into an electrical signal, and a means for inputting this electrical signal to average out the uneven portions of the light-emitting part. A means for determining the average lateral dimension, a lateral dimension of the light emitting section obtained when the electron beam is deflected in one direction, and a lateral dimension of the light emitting section obtained when the electron beam is deflected in the other direction. A CRT landing measuring device comprising means for determining the landing from the difference with the lateral dimension. (2) The CRT landing measuring device according to claim 1, which is capable of measuring landings for each of green, red, and blue beams.