JPH0688963A - Liquid crystal display panel - Google Patents

Abstract

PURPOSE:To contrive thickness reduction and easy assembly by sticking polarizing plates to a frame. CONSTITUTION:A lower polarizing plate 3 is stuck by an adhesive to the rear surface of a liquid crystal display part 2 and a light transmission plate 4 is pressed to the rear surface of the lower polarizing plate 3. A double coated adhesive tape 13 is then stuck to both side parts of this light transmission plate 4 to integrate the polarizing plate and the light transmission plate. The integrated module is then housed from below the frame 6 into the frame and the adhesive tape 15 is stuck from the rear surface of the light transmission plate 4 and the rear surface of a light source 5 to the flanks of the frame 6, by which the module and the frame 6 are integrated. Finally, the upper polarizing plate 7 is stuck by the adhesive to the frame 6 and the front surface of a glass substrate 9a. The polarizing plate 7 is formed to a size to cover the aperture of the frame 6. The liquid crystal display panel is finished thin and flawing and denting are prevented. Further, the durability of the polarizing plate 7 is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display panel. More specifically, the present invention relates to a liquid crystal display panel which can be easily assembled and whose quality is improved by attaching the polarizing plate to a frame.

[0002]

2. Description of the Related Art Liquid crystal display panels have become lighter and thinner due to recent technological innovation. However, as a result, assembly becomes difficult, and further improvement is desired in order to maintain or improve the quality of the panel itself.

As an example of a conventional liquid crystal display panel, one shown in FIG. 3 is known. The liquid crystal display panel 31 includes polarizing plates 34a, 34 on both the front and back sides inside a box-shaped frame 33 having a display opening 32 formed in the center.
The liquid crystal display unit 35 to which "b" is attached is housed.
Further, a backlight light guide plate 36 is disposed below the liquid crystal display unit 35 so that the liquid crystal display unit 35 can be irradiated with light from light sources 37 provided on both sides of the light guide plate 36. .

The liquid crystal display unit 35 has a liquid crystal material enclosed between two glass substrates 38a and 38b, and peripheral drive circuit substrates 39 are connected on both sides.

When the liquid crystal display panel 31 is assembled, first, the polarizing plates 34 are formed on both sides of the liquid crystal display unit 35.
a, 34b are attached, and this is inserted into the frame 33 at the opening 32
The upper polarizing plate 34a is housed so as to be exposed. Next, the light guide plate 36 and the light source 37 are housed below the liquid crystal display unit 35, and the inner peripheral portion of the frame 33 is caulked. That is, as is clear from FIG. 3, the frame 33 has a U-shaped cross-section that opens inward, and the glass substrates 38a and 38b of the liquid crystal display unit 35 are placed in the U-shaped open portions. The peripheral portion and the peripheral portion of the light guide plate 36 are inserted. And
With the packing 40 interposed, the U-shaped end of the frame 33 is bent to hold the inserted portion.

Next, in the liquid crystal display panel 41 of FIG. 4, the frame 43 has an L-shaped cross section, and the substrate 53 is housed in the lowermost portion. Then, after the liquid crystal display unit 45, the polarizing plates 44a and 44b, the light guide plate 46 and the light source 47 are housed in the frame 43 in the same procedure as in the panel 31, the substrate 53 is inserted at the bottom. LCD display
Similarly to the above-mentioned example, the liquid crystal material 45 is sealed between the glass substrates 48a and 48b, and the peripheral drive circuit board 49 is connected to both sides. Then, as shown in FIG. 5, a locking tongue piece 55 at the lower end of the frame 43 is inserted into an elongated locking hole 54 formed in the peripheral portion of the substrate 53 and then bent and fixed. And the upper side of the frame 43 is similar to the panel 31,
A packing 50 is interposed between the liquid crystal display unit 45 and the upper surface of the glass substrate 48a, and the inner peripheral edge of the frame 43 is bent and crimped (see FIG. 4).

As another example, the peripheral drive circuit board 49 is omitted by using the board 53 in FIG. 4 as a printed circuit board for a drive circuit, and the electrode terminals of the glass board are directly connected by conductive rubber. There is also an example in which an IC or the like is mounted on the printed circuit board.

[0008]

In each of the conventional liquid crystal display panels 31, 41, etc., the peripheral edge of the frame is caulked to the glass substrate and / or the light guide plate, so that scratches and dents are likely to occur. The thickness of the entire absolutely panel for caulking portion and the packing unit is present is increased. This is all the more true in the case of using the tongue piece 55 for locking like the panel 41 of FIGS. Moreover, since the periphery of the upper polarizing plate can be seen in the display from the opening of the frame, the display image is damaged and the cut portion (side) of the polarizing plate is exposed near the display, so that the display is caused by moisture absorption. The polarizing plate in some parts is likely to deteriorate, resulting in a shorter life.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a liquid crystal display panel which has a small thickness, is easy to assemble, and has a long life.

[0010]

A liquid crystal display panel of the present invention includes a liquid crystal display section, polarizing plates provided on both front and back surfaces of the liquid crystal display section, and a lower surface of the polarizing plate on the back side. A liquid crystal display panel comprising a backlight and a frame for accommodating and fixing the liquid crystal display unit, a polarizing plate and a backlight, the polarizing plate on the front surface side having a size that completely covers the opening of the frame. Further, the polarizing plate is provided so as to extend over both the liquid crystal display section and the frame.

Further, it is preferable that the lower surface of the backlight and the side surface of the frame are bonded by a sheet member to which an adhesive is applied.

[0012]

In the liquid crystal display panel of the present invention, it is not necessary to crimp the peripheral edge of the frame, and no locking tongue is required. Therefore, the thickness of the panel is much thinner than the conventional one. In addition, it does not require any troublesome work such as caulking and bending of the tongue, and there is no fear of scratches or dents caused by those works. Furthermore, since the cut part of the polarizing plate is farther from the display part, it stays outside the display part even if the polarizing plate absorbs moisture, and the moisture resistance in the display part is improved to shorten the life of the polarizing plate.
As a result, the life of the entire liquid crystal display panel is extended.

Also, after attaching the module (the liquid crystal display unit including the peripheral drive circuit board, the light guide plate and the light source, etc.) to the frame, the upper polarizing plate, which is apt to generate static electricity due to friction or the like, is attached. Since it can be performed, the electrostatic breakdown is drastically reduced. Moreover, since the periphery of the polarizing plate does not exist in the display portion when used, the displayed image looks beautiful.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a liquid crystal display panel of the present invention will be described with reference to the attached drawings. 1 is a perspective view of a liquid crystal display panel according to an embodiment of the present invention before assembly, and FIG. 2 is a sectional view of the panel of FIG. 1 after assembly.

In these drawings, in order to facilitate understanding, the thickness is drawn larger than the actual ratio with respect to the vertical and horizontal dimensions of the panel, and the thickness of each part is not constant. I haven't.

1 and 2, reference numeral 1 denotes a liquid crystal display panel, which is configured so that a liquid crystal display unit 2, a lower polarizing plate 3, a light guide plate 4 serving as a backlight, and a light source 5 are housed in a frame 6. Finally, the upper polarizing plate 7 is the frame 6
It is attached so as to close the upper surface opening 8. As shown, the frame 6 has an L-shaped cross section.

The above parts may be known ones. That is, in the liquid crystal display unit 2, two glass substrates 9a and 9b are attached with a sealant (not shown) so as to enclose a liquid crystal material (not shown) between them.

The upper glass substrate 9a needs to be sized so that it can be fitted into the opening 8 of the frame 6. This is because when the upper polarizing plate 7 is attached, the gap between the upper polarizing plate 7 and the upper glass substrate 9a is eliminated and the flatness of the display surface of the panel 1 is maintained. And both glass substrates 9
A frame-shaped peripheral drive circuit board 10 is provided around the TABs a and 9b.
And a flexible printed circuit (substrate) such as a flexible resin film are connected to electrodes (not shown) of the glass substrates 9a and 9b by wiring 11 (only the wiring portion is schematically shown in the figure). There is. Peripheral drive circuit board
An IC or the like is mounted on the 10 and can be driven for each pixel. In order to facilitate the connection of the wiring 11, the lower glass substrate 9b is made wider than the upper glass substrate 9a, and each electrode terminal is led out to this portion to form an electrode portion.
Forming twelve. As the upper polarizing plate 7 and the lower polarizing plate 3, a polyvinyl alcohol film in which iodine is absorbed, a polyvinyl propylal film in which iodine is absorbed, or a dichroic dye is adsorbed in polyvinyl alcohol is used. Various types are selected.

On the other hand, the light guide plate 4 is for guiding the light of the light source arranged on the lateral side to the liquid crystal display portion, and is made of, for example, a transparent plastic surface on which printing for light dispersion is applied. . If a uniform light source can be arranged directly under the liquid crystal display unit, this light guide plate is unnecessary.

As the light source 5, a fluorescent lamp, a light bulb, an EL or a cold cathode tube is usually used.

Next, the procedure for assembling the liquid crystal display panel 1 of this embodiment will be described.

First, the lower polarizing plate 3 is attached to the lower surface of the liquid crystal display unit 2 with an adhesive. Next, the light guide plate 4 is applied to the lower surface side of the lower polarizing plate 3 and attached by a double-sided adhesive tape 13 (see FIG. 2) or the like to be integrated. Then light source 5
Is also attached to both sides of the light guide plate 4 by double-sided adhesive tape 13 (see FIG. 2) to be integrated. Although the double-sided adhesive tape 13 is stopped in the middle of the light source 5 in FIG. 2, it can be more completely fixed by enclosing the light source 5 and winding it up to the back surface of the light guide plate 4, and can also be adhered to the frame 6 described later. Those integrated in this way (hereinafter referred to as modules)
The frame 14 is housed inside the frame 6 from below. At this time, it is preferable that the upper surface of the upper glass substrate 9 a of the liquid crystal display unit 2 has a thickness that matches the upper surface of the frame 6. After that, the adhesive tape 15 extends from the lower surface of the light guide plate 4 and / or the lower surface of the light source 5 to the side surface of the frame 6.
And the module 14 and the frame 6 are integrated.
When the module 14 and the frame 6 are integrated, the light source 5 and the light guide plate 4 may be integrated at the same time as described above. Finally, the upper polarizing plate 7 is attached to the periphery of the upper surface of the frame 6 and the upper surface of the upper glass substrate 9a with an adhesive to complete the process. The upper polarizing plate 7 can be adhered by using the same adhesive as that usually attached to the glass substrate 9a.

The liquid crystal display panel and the driver IC are connected to peripheral circuits such as a crosstalk prevention circuit, a noise prevention circuit, a power supply circuit, or a signal circuit thereof.

Therefore, if the upper polarizing plate 7 is attached after the module 14 is attached to the frame 6 as described above, it is difficult for the static electricity when the polarizing plate is attached to be directly applied to the liquid crystal display panel or IC, and the resistance to static electricity is high. Is improved. Moreover, since the cut portion (side edge) of the upper polarizing plate 7 extends outward from the display portion, even if the polarizing plate absorbs moisture, the alteration remains outside the display portion and does not affect the display characteristics. As a result, the life is extended.

In the present embodiment, the adhesive tape 15 is used to connect the lower surface of the module 14 to the frame 6, but the present invention is not limited to the adhesive tape and may be, for example, a resin mold or a resin mold. A reflective film or the like may be used.

In the above embodiment, the peripheral drive circuit board of the liquid crystal display section is arranged around the glass substrate, but the peripheral drive circuit board may be arranged in two directions, or may be bent or arranged at the bottom. However, the present invention can be applied.

Further, in this embodiment, the backlight is constituted by the light guide plate and the light source to illuminate the liquid crystal display portion. However, it is not always necessary to adopt this constitution as described above, and the direct type light or EL is used. Any light source capable of irradiating uniform light such as those mentioned above is referred to as a backlight including them.

[0028]

The liquid crystal panel of the present invention has an extremely thin and light finish, is prevented from scratches and dents, and has improved durability of the polarizing plate. Moreover, since the upper polarizing plate is attached last, electrostatic breakdown can be prevented, and since the periphery of the upper polarizing plate does not exist in the display surface (corresponding to the opening of the frame), the image quality of the display image is improved.

As a result, it is possible to obtain a small-sized and high-performance liquid crystal display device which matches the recent trend of light, thin, short and small electronic devices.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an embodiment of a liquid crystal display panel of the present invention.

2 is a cross-sectional explanatory view after assembly of the liquid crystal display panel of FIG.

FIG. 3 is a cross-sectional explanatory view showing an example of a conventional liquid crystal display panel.

FIG. 4 is a cross-sectional explanatory view showing another example of a conventional liquid crystal display panel.

5 is a partial perspective view showing a connection portion on the lower surface of the liquid crystal display panel of FIG.

[Explanation of symbols]

 1 liquid crystal display panel 2 liquid crystal display section 3 lower polarizing plate 4 light guide plate 5 light source 6 frame 7 upper polarizing plate 9a glass substrate 9b glass substrate 13 double-sided adhesive tape 15 adhesive tape

Claims (2)

[Claims] 1. A liquid crystal display unit, polarizing plates provided on both front and back surfaces of the liquid crystal display unit, a backlight provided on the lower surface of the polarizing plate on the back side, the liquid crystal display unit, and a polarizing plate. And a frame for accommodating and fixing a backlight, wherein the polarizing plate on the front surface side is sized to completely cover the opening of the frame, and the polarizing plate has the liquid crystal display. A liquid crystal display panel that is arranged so as to extend over both the unit and the frame. 2. The liquid crystal display panel according to claim 1, wherein the lower surface of the backlight and the side surface of the frame are bonded by a sheet member to which an adhesive is applied.