JPH035728A - Scattering method for extremely small body - Google Patents

Abstract

PURPOSE:To prevent the display picture quality of a high-density or large-area liquid crystal panel from deteriorating and to improve the manufacture yield by scattering extremely small bodies in a scattering container through a filter which has passing holes whose diameter is larger than the grain size of the extremely fine bodies. CONSTITUTION:Gas of dry air, nitrogen, etc., is blown from a blowing pipe 18 from above a receiving dish 17 to float a spacer 10 in the sealed container 19. The container 19 is sealed, so the floated spacer 10 is sent in the scattering container 15 through a communication pipe or hose 20 as a discharge port together with the gas of dry air, nitrogen, etc., to strike on a reflecting plate 21, so that the spacer is scattered in the scattering container 15. The scattered spacer 10 falls naturally with time over a glass substrate 2 or 3, so a lump spacer 10 is removed by installing the filter 22 on the way of the communication pipe 20. Consequently, the display picture quality is prevented from deteriorating.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for dispersing minute objects such as spacers used to regulate the gap of a liquid crystal panel having the function of displaying images or characters.

Conventional technology Due to recent advances in microfabrication technology, liquid crystal materials, and mounting technology, it has become possible to obtain television images on a commercial basis with small LCD panels of approximately 2 to 6 inches in size but without any problems in practical use. (ix) RGB on one of the two translucent insulating substrates that constitute the liquid crystal panel, such as a glass substrate.
Color display was easily realized by forming a colored layer, and each picture element had a built-in switching element.
A so-called active type liquid crystal panel guarantees an image with little crosstalk and a high contrast ratio.

Such liquid crystal panels (Table 1) In many cases, an alignment film is selectively applied by printing on a transparent scratched surface formed on a glass substrate.Alignment treatment is performed by a method such as rubbing, in which the alignment film is rubbed with a dry cloth. A pair of glass substrates with a thickness of several micrometers
It is constructed by forming a closed space by facing each other with a gap of m, and filling the closed space with liquid crystal. Depending on the characteristics of the liquid crystal used, one or two polarizing plates are attached to a glass substrate.

FIG. 2 is a perspective view showing an exploded state of a simple matrix type liquid crystal panel j. A pattern group of scanning lines 4 made of a transparent conductive film is formed on the whole surface of one glass substrate 2, and a pattern group of signal lines 5 made of a transparent conductive film is formed on the whole surface of the other glass substrate 3. A pattern group is formed.

The pair of glass substrates 2 and 3 are bonded together so that the scanning line 4 and the signal line 5 are approximately perpendicular to each other. A seal 6 obtained by solidifying the adhesive forms a space that confines the liquid crystal, and at the same time bonds and integrates the pair of glass substrates 2 and 3. The notch 7 formed in the pattern of the seal 6 is a passage into which liquid crystal is injected, and after being injected, it is filled with a sealing material also made of adhesive. In the area where images or text are displayed (
In order to orient the liquid crystal molecules, an organic resin thin film such as a polyimide thin film is formed as the alignment film 8.

FIG. 3 shows a cross-sectional view of the colored liquid crystal panel 1 taken parallel to the scanning line 4. As shown in FIG. The above-mentioned alignment film 8 is in contact with the liquid crystal 9, and the closed space formed by the pair of glass substrates 2 and 3 and the seal 6 is filled with the liquid crystal 9.
The spacer IO is a translucent insulating material placed between the pair of glass substrates 2 and 3 to maintain the thickness (gap) of this closed space at a predetermined thickness, and as shown in the figure, the spacer IO is made of glass fibers with the same diameter. Alternatively, plastic balls (beads) of uniform particle size are used.

A transparent wire 11 is used to prevent the scanning line 4 and the signal line 5 from being short-circuited due to conductive foreign matter mixed in therein, and to prevent direct current from flowing through the liquid crystal 9 and deteriorating the characteristics of the liquid crystal panel. For example, a silica (SiO2) film is used. Reference numeral 12 denotes a colored layer formed by coloring an organic thin film such as gelatin with a dye, and three primary color layers of R, G, and B given predetermined spectral characteristics are arranged according to the optical design of the color filter. A region adjacent to the colored layer 12 is a thin film layer 1 that is opaque to the light source light.
Filling with 3 is advantageous because an image with a high contrast ratio can be obtained. A so-called black matrix treatment (for making the thin film layer 13 opaque, a metal thin film such as chromium (Cr) may be used), or the three primary color layers of R, G, and B may be overlaid as appropriate, or a new black matrix may be used. A colored layer may be added, and there is considerable freedom in designing and manufacturing the color filter. As mentioned earlier, 14 is a polarizing plate, and the liquid crystal 9
When using TN (twisted nematic) material, two upper and lower sheets are required.
If a material of the same type is used, one sheet is required. Supplying electrical signals to the scanning line 4 and signal line 5 ζ A large number of conductive thin film patterns are provided on the glass substrates 2 and 3 at the outer periphery from the seal 6. This is accomplished by means (mounting) such as pressing the film onto the terminal group of the scanning line or signal line using an adhesive.

Now, the strength of the spacer IO which determines the cell thickness of a liquid crystal panel is generally carried out using a spraying device as shown in FIG. 4 at present. First, a spraying container 15 that is nearly sealed is prepared, and one of the glass substrates 2 (or 3) is placed at the bottom of the spraying container 15 through the loading/unloading port 16. Next, a predetermined amount of spacers 10 made of glass fiber, for example, are placed in the tray 17 in the upper receptacle in the distribution container 15.

Then, the receiver blows dry air or a gas such as nitrogen from above the plate 17 for a short time from the pipe 18, causing the spacer 10 to fly up inside the container 15. The spacers 1O that have flown up naturally fall down as time progresses and are scattered on the glass substrate 2.

Therefore, the amount of spacers 10 sprinkled on the glass substrate 2 is proportional to the amount placed in the tray 17, and in order to uniformly distribute the spacers 10, the shape of the tray 17, the amount and speed of the gas to be sent, etc. This may be because it is a control element, but such a spacer has a diameter of several micrometers and a diameter of several tens of micrometers.
Glass fibers with a length of m and plastic beads with a particle size of a few μm are used. In order to improve the accuracy of the cell (gap) thickness of a liquid crystal panel (Table 1), the greater the number of spacers, the better the strength.The more diffusely reflected light from the spacers increases, the contrast ratio decreases, so there is a natural restriction.

From the viewpoint of improving display image quality, plastic beads are more desirable as spacers for the reasons mentioned above.Problems to be Solved by the InventionHowever, since spacers are small in shape, they are strongly influenced by the surface area that is easily activated. Very easy to absorb moisture. This tendency is especially noticeable with plastic beads, and humidity control is important when preserving them.

Therefore, when moisture is adsorbed, in the conventional example described above, no matter how strongly the dry gas is sprayed, the plastic beads will not completely break up, and there is a probability that several to several dozen condensed lumps will be dispersed. The problem is that it gets expensive. The lumped plastic beads strongly scatter the light from the light source, so they appear to be constantly lit on, for example, a liquid crystal panel display screen, and in extreme cases, they can become point defects and lose their marketability.

Particularly when displaying an image by magnifying it with an optical component such as a lens rather than viewing it directly, for example when used as a monitor for a television camera or as a projection television (the presence of clumpy plastic beads can significantly affect the image quality). In particular, when the display mode is normally black, the white spot defect that always lights up on a dark screen when there is no signal is very noticeable. Means for Solving the Problems The present invention involves dispersing minute objects in a dispersion container.
The micro objects are passed through a filter having a passage port with a diameter larger than the particle size of the micro objects, and then scattered into a scattering container.

Effects of the Invention The above-described configuration makes it possible to filter out large clusters of microscopic objects, thereby making it possible to avoid deterioration in display image quality in the manufacture of liquid crystal panels, for example.

Embodiment FIG. 1 is a perspective view showing the structure of a spacer dispersing device made of plastic beads in an embodiment of the present invention. Method for preparing an airtight container 19 separate from the scattering container 15 for spreading the spacers 10. In this airtight container 19, a receiving plate 1 is placed.
7, and the receiver is inserted into the plate I through an appropriate opening/closing opening (not shown).
A predetermined amount of spacer 10 is inserted into 7, and the receiver is plate 17.
Dry air or a gas such as nitrogen is blown from above from the vibrator 18, causing the spacer 10 to fly up inside the closed container 19. Since the airtight container 19 is sealed, the spacer 10 that flies up is sent into the spraying container 15 along with dry air or gas such as nitrogen through the communication vibrator or hose 20 that is the exhaust port, hits the reflector plate 21, and returns to the spraying container I5. Soar within. The spacers 10 that have flown up naturally fall down as time progresses and are scattered onto the glass substrate 2 or 3-J:.

Therefore, it will be understood that if the filter 22 is installed in the middle of the communication vibrator 21, the lump-like spacer 10 can be eliminated. The optimal size of the passage hole of the filter 22 is about 2 to 3 times the particle size of the spacer 10 made of plastic beads; if the passage hole is smaller than that, the filter 22 will quickly become clogged, making it impractical. Moreover, if the passage opening is larger than that, a few dozen lumps will easily pass through, and the intended purpose will not be achieved (- In order to speed up the sedimentation rate of the spacer IO, a spray container is used. Even in known examples such as Japanese Patent Application Laid-Open No. 63-077026 in which the inside of the apparatus is under reduced pressure, the usefulness of the present invention is not impaired and is still effective.

In the above explanation, the glass substrate 2 or 3 constituting the liquid crystal panel is an example, but it goes without saying that there is no problem with the use of a jig such as a tray on which a plurality of glass substrates are stacked. As explained above, in the present invention, microscopic objects broken up by gas spraying are passed through a filter and then scattered onto the substrate. For example, in high-density or large-area liquid crystal panels, deterioration in display image quality can be prevented and manufacturing yields can be improved, which is an excellent effect.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing the configuration of a device used for dispersing minute objects in an embodiment of the present invention; Fig. 2 is an exploded perspective view of a liquid crystal panel; Fig. 3 is a detailed cross-sectional view of the same panel;
The figure is a perspective view showing the configuration of a device used for dispersing minute objects in a conventional example. Glass substrate, 10. ,,spacer, 1
51. , spray container 18. ,,pipe for spraying, 22
．． ,,filter.

Claims (2)

[Claims] (1) A predetermined amount of micro objects is scattered in a spraying container by blowing gas onto the micro objects, and after a certain period of time, the particles of the micro objects are dispersed onto the substrate placed at the bottom of the scattering container. A method for dispersing minute objects, characterized in that the minute objects are dispersed into the scattering container after passing through a filter having a passage port having a diameter larger than the diameter of the filter. (2) The method for dispersing minute objects according to claim 1, wherein the inside of the dispersion container is in a reduced pressure state when the minute objects are scattered.