JPH0876117A - Production of liquid crystal display device - Google Patents

Abstract

PURPOSE: To obtain uniform distribution of brightness on the display surface of a liquid crystal display substrate. CONSTITUTION: This liquid crystal display device consists of a liquid crystal display substrate and a light guide plate 1 disposed on the back surface of the liquid crystal display substrate. By forming films 30 on the principal surface of the light guide plate 1 facing the liquid crystal display substrate in such a manner that the film 30 has higher refractive index than the light guide plate 1, light beams entering the side faces can be introduced to the principal surface. When the films 30 are formed on the light guide plate 1, a magnet 50 is disposed on the opposite side to the principal surface of the plate 31, and light-diffusing particles 21 including a magnetic material are mixed in the material for the films 30.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a liquid crystal display device, and more particularly to a method of manufacturing a liquid crystal display device called a backlight system.

[0002]

2. Description of the Related Art A liquid crystal display device, which is a so-called backlight system, is provided with a light emitting body made of hot and cold cathode rays, which is called a CFL, and the light emitting body is arranged on the back surface of a liquid crystal display substrate. It is positioned at one end side of the light guide plate.

This light guide plate is adapted to take in light from the light emitting body from its end side surface and to emit it from the main surface facing the liquid crystal display substrate.

Then, in order to make the emission of the light guided into the light guide plate from the main surface sufficient, a coating film having a larger light refractive index than the light guide plate is formed in a dot shape on the main surface of the light guide plate. They are arranged and formed.

As a result, a so-called backlight having a uniform light intensity distribution is provided on the back side of the liquid crystal display substrate.

Such a technique is described in, for example, “Akio Ohara,“ Backlight for Liquid Crystal Display ”, Journal of Japan Society of Illumination 73
Volume 12, No. 12, 1989).

[0007]

However, in the liquid crystal display device having such a structure, the size of the display surface tends to increase in recent years, so that the position where the luminous body is positioned on the display surface is increased. It has been pointed out that the brightness is not particularly sufficient at the far part, resulting in uneven brightness of the light.

Therefore, the present invention has been made under such circumstances, and the object of the present invention is to provide a uniform distribution of brightness on the display surface of a liquid crystal display substrate. Another object of the present invention is to provide a method for manufacturing the liquid crystal display device.

[0009]

In order to achieve such an object, the present invention comprises the following means.

Means 1. A liquid crystal display substrate and a light guide plate disposed on the back surface of the liquid crystal display substrate are provided, and the light guide plate has a coating having a higher optical refractive index than the light guide plate formed on the main surface of the liquid crystal display substrate side. In the liquid crystal display device configured to guide the light from the end side surface to the main surface side by the presence of the other surface, the other surface facing the main surface of the light guide plate when the coating film is formed on the light guide plate. It is characterized in that a magnet is arranged on the side and light-diffusing particles containing a magnetic material are mixed in the material of the coating film.

Means 2. A liquid crystal display device comprising a liquid crystal display substrate and a light guide plate disposed on the back surface of the liquid crystal display substrate, wherein the light guide plate is configured to guide light from an end side surface thereof to the main surface side. At the time of forming the light plate, the light diffusing particles containing the magnetic material are mixed in the light guide plate material in the melting stage and the magnets are arranged to face each other, and the distribution state of the light diffusing particles in the material is set to the intensity distribution of the electromagnet. It is characterized by making them correspond.

[0012]

First, according to the construction of the means 1, all of the light diffusing particles mixed in the material of the coating film formed on the main surface of the light guide plate are attracted by the magnet, and the magnetic substance contained in each of them is guided. It comes into full contact with the main surface of the light plate.

Therefore, when the light from the end side surface of the light guide plate is guided to the main surface side where the coating having a higher light refraction than that of the light guide plate is formed, the light diffusing particles mixed in this coating. Will be fully diffused by.

Therefore, it is possible to prevent the light emitted from the main surface of the light guide plate from becoming uneven, and to provide a uniform distribution of brightness on the display surface of the liquid crystal display substrate.

Further, according to the constitution of the means 2, since the distribution state of the light diffusing particles of the light from the end side surface of the light guide plate can be controlled according to the optical path difference, the light emitted to the main surface side is uneven. It can be prevented from being generated, and a uniform distribution of brightness can be provided on the display surface of the liquid crystal display substrate arranged facing the light guide plate.

[0016]

FIG. 2 is an exploded perspective view showing an embodiment of a liquid crystal display device which is a target of the manufacturing method of the present invention, and particularly shows an exploded perspective view of a liquid crystal display module.

In FIG. 1, first, there is a light guide plate 1 made of, for example, an acrylic plate. A light emitting body made of CFL 2 is arranged on one end side surface of the light guide plate 1.

The CFL 2 is attached to the light guide plate 1 through rubber bushes 3 at both ends thereof.

There is a light-shielding sheet 4 covering the CFL 2 so that the light of the CFL 2 is entirely irradiated into the light-guide plate 1. Both ends of the light-shielding sheet 4 are attached to the front and back surfaces of the light-guide plate 1, respectively. There is.

Further, above the CFL2, the CFL2
The CFL protective cover 5 arranged so as to cover the light guide plate 1 is attached to the light guide plate 1 by using, for example, a screw.

A liquid crystal display substrate 7 is arranged on the surface of the light guide plate 1 with a diffusion sheet 6 interposed therebetween. Thereby, the light from the CFL 2 is irradiated into the light guide plate 1 from the end side surface of the light guide plate 1, diffused and emitted by the diffusion sheet 6 arranged on the main surface thereof, and transmitted through the liquid crystal display substrate 7. It is like this.

Although not shown in detail in FIG. 2, the liquid crystal display substrate 7 is composed of two glass substrates with a liquid crystal interposed, and an electrode (not shown) is provided on a part of the periphery thereof.

On the other hand, a printed wiring board 8 is arranged on the back side of the light guide plate 1, and the wiring on the surface of the printed wiring board 8 is connected to the electrodes on the liquid crystal display board 7 via a connector 9. It has become so.

Further, the printed wiring board 8 also serves as a base for mounting the frame 10. This frame 10 is a metal plate having an opening provided in a portion corresponding to the display area of the liquid crystal display substrate 7, and by caulking a claw portion 10A formed on a side surface thereof on the printed wiring board 8, The liquid crystal display substrate 7, the light guide plate 1 and the printed wiring board 8 are integrated.

The liquid crystal module thus integrated has a cross section as shown in FIG. 3, which is a cross sectional view taken along line III-III in FIG.

Here, the light guide plate 1 is provided on the surface of the light guide plate 1 on the liquid crystal display substrate 7 side, that is, on the main surface in contact with the diffusion plate 6.
A film having a larger optical refractive index than that is formed in a dot shape, for example. As the material of this coating, for example, titanium oxide, styrene, or glass is used. As a result, the light guided from the light emitting body 2 into the light guide plate 1 is emitted from the main surface side where the coating is formed by this coating.

Then, in this embodiment, light diffusing particles are mixed in the coating film, and are formed as shown in FIG.

That is, the coating film 30 is formed on the main surface of the light guide plate 1 by a printing technique, and the coating material before the printing is the light diffusion particles 21 as shown in FIG. Are mixed, and this light diffusion particle 2
A magnetic material 23 is included in the magnetic recording medium 1.

Here, the light diffusion particles 21 are made of, for example, acrylic, styrene, polycarbonate, titanium oxide, or SiO ₂ , and are not limited to the shape shown in FIG. 4A, but the shape shown in FIG. 4B. May be

After the coating film 30 is formed by the printing technique as described above, the magnet 50 is arranged on the back surface of the light guide plate 1 so that the light diffusion particles 21 mixed in the coating film 30 are included therein. By attracting the magnetic body 23, the magnetic body 23 is brought into contact with the main surface of the light guide plate 1.

In this case, the light diffusion particles 21 mixed in the material of the coating film 30 formed on the main surface of the light guide plate 1 are mixed.
In all of the above, the magnetic body 23 included in each
Is sucked by and comes into complete contact with the main surface of the light guide plate 1.

Therefore, when the light from the end side surface of the light guide plate 1 is guided to the main surface side where the coating film 30 having a higher light refraction than that of the light guide plate 1 is formed, it is mixed with the coating film 30. The light-diffusing particles 21 existing therein are sufficiently diffused.

Therefore, it is possible to prevent the light emitted from the main surface of the light guide plate 1 from becoming uneven, and to provide a uniform distribution of brightness on the seven display surfaces of the liquid crystal display substrate.

In the above embodiment, the magnet 50 is used.
In the region facing the light guide plate 1, the magnetic force is uniform, but the magnetic force is not limited to this, and the magnetic force may be nonuniform.

That is, the light diffusing particles 21 in the respective coatings 30 formed on the light guide plate 1 are brought into complete contact with the surface of the light guide plate 1 depending on the distance from the light emitting body 2, or to some extent from the surface. This is because the light diffusion state according to the region can be optimized by arranging it in a floating manner.

FIG. 5 is a constitutional view showing another embodiment of the method for manufacturing a liquid crystal display device according to the present invention.

In the figure, there is a light guide plate 1, and this light guide plate 1 is in a melting stage which has not been solidified yet. The light diffusing particles 21 as shown in FIG. 4A or FIG. 4B are dispersed in the light guide plate 1, and the magnet 50 is disposed so as to face the light guide plate 1, thereby The distribution state of the diffusing particles 21 is controlled.

For example, in FIG. 5, when the end side of the light guide plate 1 on which the light emitting body 2 is arranged is A, the light diffusion particles are extended to the other side B opposite to the end on the A side. 21
The dispersion density of is gradually increasing.

By doing so, the diffusion of light is relatively increased in accordance with the region of the light guide plate 1 that is farther from the light emitting body 2, and unevenness of the light amount is prevented.

Here, the magnet 50 is formed of an assembly of a plurality of electromagnets 50A as shown in FIG. 6 so that the magnetic force can be set to an arbitrary value in each region facing the light guide plate 1. At the same time, an arbitrary current can be passed through each electromagnet.

In this case, since the light guide plate 1 in which the distribution state of the light diffusing particles can be controlled according to the optical path difference of the light from the end side surface, the light emitted to the main surface side is uneven. It can be prevented from being generated, and a uniform distribution of brightness can be provided on the display surface of the liquid crystal display substrate.

[0042]

As is apparent from the above description,
According to the method of manufacturing a liquid crystal display device of the present invention, it is possible to provide the liquid crystal display substrate with a uniform brightness distribution on the display surface.

[Brief description of drawings]

FIG. 1 is a main part configuration diagram showing an embodiment of a method for manufacturing a liquid crystal display device according to the present invention.

FIG. 2 is an exploded perspective view showing an embodiment of a liquid crystal display device to which the present invention is applied.

FIG. 3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a configuration diagram showing an example of light diffusing particles used for carrying out the present invention.

FIG. 5 is a main part configuration diagram showing another embodiment of a method for manufacturing a liquid crystal display device according to the present invention.

FIG. 6 is a configuration diagram showing an example of a magnet used for implementing the present invention.

[Explanation of symbols]

 1 ……………… Light guide plate 2 ……………… Light-emitting body 21 ……………… Light-diffusing particles 23 ……………… Magnetic material 30 ……………… Coating film 50 ……………… Magnet 50A …………electromagnet

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hirotsugu Muramatsu 3350 Hayano, Mobara-shi, Chiba Hitachi Electric Devices, Inc. (72) Inventor Kazuya Tanaka 3350 Hayano, Mobara, Chiba Hitachi Electric Device Within Shizu Corporation

Claims (2)

[Claims] 1. A liquid crystal display substrate, and a light guide plate disposed on the back surface of the liquid crystal display substrate, the light guide plate having a higher light refractive index than the light guide plate on the main surface of the liquid crystal display substrate side. In a liquid crystal display device in which light from an end side surface of the liquid crystal display device is guided to the main surface side by forming the film, when forming the film on the light guide plate, A method of manufacturing a liquid crystal display device, wherein a magnet is arranged on the other surface side facing each other, and light diffusing particles containing a magnetic material are mixed in the material of the coating film. 2. A liquid crystal display comprising a liquid crystal display substrate and a light guide plate arranged on the back surface of the liquid crystal display substrate, the light guide plate being configured to guide light from an end side surface thereof to the main surface side. In the device, when the light guide plate is formed, light diffusing particles containing a magnetic material are mixed in the light guide plate material in the melting stage and magnets are arranged to face each other, and the distribution state of the light diffusing particles in the material is described above. A method of manufacturing a liquid crystal display device, which is adapted to the intensity distribution of an electromagnet.