JPS6366020B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an exposure table light source position measuring method and apparatus for adjusting the light source position of an exposure table used in a fluorescent surface forming process of a cathode ray tube.

In general, an exposure table used in the process of forming a fluorescent surface of a cathode ray tube includes an exposure table main body 1 consisting of a casing, a light source 2 and a lens 3 provided in the exposure table main body 1.
It consists of Usually, multiple exposure stands of this type are installed due to production volume and exposure time, and when producing high-precision fluorescent surfaces,
It is necessary to set the exposure conditions of each exposure platform to the same optimum conditions.

Conventionally, when adjusting the light source position of this exposure table, the exposure table in which the panel mounting positions of the light source 2, lens 3, and exposure table main body 1 are optimally set is used as a reference, and on this reference exposure table, A panel 5 with a shadow mask 4 attached is attached, and the position of the image of light after passing through the shadow mask 4 on the inner surface of the panel 5 is measured with a microscope 6.

Next, the panel 5 is moved to another exposure table to be adjusted, the position of the light image is measured in the same manner, and the positions of the light source and lens are adjusted so that this position coincides with the reference exposure table. In this way, since it is necessary to make adjustments so that the same image as that of the reference exposure stage is produced at all points on the panel, the adjustment is made while performing similar measurements at several points on the panel. This requires a lot of time, and it is necessary to repeat this procedure several times, including re-measurement after adjustment and re-adjustment when the amount of deviation cannot be ignored. In addition, with this optical measurement method, the measurement error on the panel surface is 10 μm or more, and as mentioned above, the measurement time is long, so thermal deformation of the shadow mask occurs during the work. Adjustment errors are likely to occur. Furthermore, since the adjustment panel and shadow mask change over time, it is necessary to manage and update the adjustment panel and shadow mask.

The present invention was made in view of the above circumstances, and
An exposure table light source position measuring method that can automatically measure the position of a light source image at several points in a short time with high precision by detecting the light source position on an exposure table using a light receiver having an optical sensor, and the method thereof. The purpose is to provide equipment.

Embodiments of the present invention will be described in detail below with reference to the drawings. Figure 2 shows the principle of this embodiment.
A light receiver 14 is mounted on a panel mounting surface on an exposure stage main body 13 in which a light source 11 and a lens 12 are built-in. The light receiver 14 is provided with a small hole 15 facing the light source 11, and an optical sensor, such as a semiconductor line sensor 16, is provided inside the light receiver 14 facing the small hole 15. The output end of this semiconductor line sensor 16 is connected to a digital display section 17. The semiconductor line sensor 16 has a diameter of 25 μm, for example.
Photodiodes are lined up at a pitch of , and the output of each element can be seen.

That is, the light emitted from the light source 11 is refracted by the lens and travels through the small hole 1 provided in the light receiver 14.
5, and forms an image of the light source 11 on the semiconductor line sensor 16 on the opposite side using the principle of a pinhole camera. Since each semiconductor element of the semiconductor line sensor 16 generates an output according to the amount of light, this output is processed by the microcomputer of the digital display section 17 to determine which semiconductor element on the semiconductor line sensor 16 the image of the light source 11 is present on. The position is calculated and displayed on the digital display section 17.

Next, see the third section on how to adjust the exposure table light source position.
This will be explained with reference to Figures a and b. That is, since the accuracy of the lens 12 is generally poor, measurements are taken at nine locations, and the position of the light source 11 is adjusted so that the measurement position is within a certain range at all of the locations. Therefore, nine light receivers 141, 142, . Thereafter, the fixed frame 15 is positioned using the stopper 16 in the same way as the panel, and mounted on the reference exposure table main body 13, and each of the light receivers 141, 142...148, 1
At 49, the position of the image of the light source 11 is measured and electrically stored on the digital display. Next, the fixed frame 15 to which the nine light receivers 141, 142...148, 149 are attached is positioned and mounted on the exposure table body to be adjusted using a stopper, and each of the light receivers 141, 1
42...148, 149 measure the position of the image of the light source and input it to the digital display section. On the digital display section, the light source 11 of the reference exposure table 13 that has been stored is displayed.
Displays the amount of forward and reverse deviation from the image position. The operator adjusts the positions of the light source and lens so that this amount of deviation becomes small.

Next, a signal processing method and an adjustment method will be explained. That is, as shown in FIG. 5, the line sensor 16 has a plurality of pixels, for example, 51 pixels.
When a line sensor 16 with 2 pixels is used, when a timing clock is applied from the timing generation circuit 31, an output as shown in FIG. 6 is obtained. In this output diagram, the mountainous portion indicates that that pixel was strongly irradiated with light.

This signal is sent to the memory 3 using an A/D converter 32.
3 is written as numerical data.

The data on the memory 33 is calculated using the calculator 34 to find the center position "a" of the mountain (upper part of FIG. 6).
The obtained value a is displayed for each sensor.

FIG. 7 shows the difference in the trajectory of the light ray when the light source 11 is at the normal position A and when it is at the downward position B.
The figure shows when the light source 11 is at the normal position A' and when the light source 11 is at the right position.
The difference when it deviates to B′ is displayed. At this time,
The images of the light source formed on the line sensor 16 are shown as a and a' when they are normal, and b and b' when they are out of alignment. However, if it is shifted to the right B', the image position b' will be shifted to the left from a'.

Therefore, if it is known how much and in which direction the output values of the two sensors 16 deviate from the normal values, it becomes possible to match them in the vertical and horizontal directions. In reality, there is a curved lens 12 on top of the light source 11, and due to design errors, the ray trajectory at each location is affected by lens precision and differs for each exposure table. Therefore, measurements should be made at as many locations as possible. It's better to do it.

Next, the principle of an exposure table light source position measuring device used in the process of forming a fluorescent surface of a color cathode ray tube will be explained with reference to FIG. Light source 22 inside the exposure table main body 21
5mm to form a fluorescent surface in three colors: red, green, and blue.
Move to 3 positions at regular intervals. On the other hand, receiver 2
3, small holes 241, 242, and 243 are provided at three locations at intervals of 2.5 mm corresponding to the three colors. Therefore, when observing the light source 22 at a certain position, one small hole 242 is used and the other two small holes 241 and 2
43 using a light shielding plate 25. In this way, the light source 2 is placed approximately in the center of the semiconductor line sensor 26.
2 images can be formed, and measurements can be made over a considerable range without using a long semiconductor line sensor or tilting the light receiver 23. 27 is a lens, and 28 is a digital display section.

In this way, the images of the light source at several locations can be measured in a few seconds, so the adjustment time is extremely short, and since the amount of deviation is constantly displayed, the adjustment is extremely easy.

As described above, according to the present invention, the position of the image of the exposure table light source can be automatically detected at several points in a short time, and the accuracy of the light source position measuring device is ±
It has an extremely high precision of 1 μm, and does not use a cathode ray tube panel or shadow mask, which helps prevent thermal deformation and aging.

In addition, in the above embodiment, a shadow mask with rectangular holes is assumed, and an example in which a semiconductor line sensor is used as an optical sensor is explained. However, the light source position measurement of an exposure stage for a shadow mask with circular holes needs to be performed in two dimensions. In this case, it is necessary to use a so-called matrix type sensor.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view showing a conventional exposure table light source position measuring device, Fig. 2 is a cross-sectional view showing the principle of an embodiment of the present invention, and Fig. 3 a and b are plan views showing an embodiment of the present invention. FIG. 4 is a sectional view showing the principle of another embodiment of the present invention, and FIGS. 5 to 8 are explanatory diagrams for explaining an example of the signal processing method and adjustment method according to the present invention. be. 11... Light source, 12... Lens, 13... Exposure table main body, 14... Light receiver, 15... Small hole, 16...
...Semiconductor line sensor, 17...Digital display section.

Claims (1)

[Scope of Claims] 1. An exposure table main body having a cathode ray tube panel mounting section on its upper part and housing a light source and a lens therein, and a small hole attached to the cathode ray tube panel mounting section for the light source. a light receiver, a light shielding plate provided in the light receiver to block light from small holes other than the small holes corresponding to the positional movement of the light source, and an image of the light source provided in the light receiver and linked by the small hole; An exposure table light source position measuring device that has an optical sensor that detects the image of the light source, and a display unit that processes the output from the optical sensor to calculate where the image of the light source is on the optical sensor and displays the position. is used to measure the position of the image of the light source at several locations, and the positions of the light source and the lens are adjusted based on the difference from the position of the image of the light source in an ideal case determined in advance. A method for measuring the exposure table light source position. 2. An exposure stage main body having a cathode ray panel mounting section on the top and housing a light source and a lens therein, a light receiver mounted on the cathode ray tube panel mounting section and having a small hole for the light source, and this light receiver. a light-shielding plate provided in the light receiver to block light from small holes other than the small hole corresponding to the positional movement of the light source; an optical sensor provided in the light receiver to detect an image of the light source connected by the small hole; An exposure table light source position measuring device characterized by comprising a display unit that processes the output from the optical sensor, calculates where on the optical sensor the image of the light source is located, and displays the position.