JP2003035910A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal display device wherein static electricity is prevented from flowing into the internal part of a liquid crystal panel from the end part of a signal line exposed to the external part and thus the fluctation of threshold voltage (Vth) is prevented. SOLUTION: The liquid crystal display device has a first substrate, a second substrate and a liquid crystal layer interposed between the two substrates and the surface opposite to the surface on the side opposed to the liquid crystal layer of the first substrate or the second substrate is used as the display surface of the liquid crystal display device. The first substrate has a plurality of the signal lines on the surface opposed to the liquid crystal layer thereof and a protective film is provided at at least one side face where the signal lines are exposed of the side faces directed along the direction crossing the display surface of the first substrate or the second substrate.

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 device, and more particularly to a technique effective when applied to a small liquid crystal display device used in a mobile device such as a mobile phone.

[0002]

BACKGROUND ART STN (S uper T wisted N ematic ) method or a liquid crystal display module of TFT (T hin F ilm T ransistor ) scheme, the number of pixels, for example, 800 × 480 × 3 or more color display The liquid crystal display module having the large-sized liquid crystal display panel is widely used as a display device for notebook personal computers and the like. The number of pixels is, for example, 100 × 150 × in color display.
A liquid crystal display module having a small liquid crystal display panel of about 3 is widely used as a display unit of a mobile device such as a mobile phone. In the liquid crystal display module used in this mobile phone, an STN type liquid crystal display panel is used, but in recent years, a TFT type liquid crystal display panel is also being used. Such a technique is described in, for example, Japanese Patent Laid-Open No. 5-257142.

[0003]

In a liquid crystal display panel, a first transparent substrate (for example, a glass substrate) and a second transparent substrate are bonded together via a sealant, and the first and second substrates are bonded together. It is configured by injecting and sealing a liquid crystal in between. Generally, in a TFT type liquid crystal display panel, for example, pixels having thin film transistors (TFTs) that are switching elements and pixel electrodes are provided in a matrix on a first transparent substrate, and each thin film transistor (TF) is provided.
A plurality of gate signal lines for supplying a control voltage for turning on and off a thin film transistor (TFT), and a video signal voltage for displaying an image on a liquid crystal display panel,
A plurality of drain signal lines for supplying each pixel electrode are provided. One end of each drain signal line is connected to a drain driver that supplies a video signal voltage to each drain signal line, and one end of each gate signal line supplies a control voltage to each gate signal line. Connected to the gate driver.

The conventional liquid crystal display panel has a structure in which the other end of at least one of the drain signal lines and the gate signal lines is exposed to the outside on the side surface of the liquid crystal display panel. Therefore, in the conventional liquid crystal display panel, static electricity flows into the liquid crystal display panel from the other end of the signal line exposed to the outside during the manufacturing process, and the thin film transistor (TFT) is destroyed, or the thin film transistor (TFT) is destroyed. There is a problem that the threshold voltage (Vth) of () changes. The present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide static electricity into the liquid crystal display panel from the end of the signal line exposed to the outside in the liquid crystal display device. It is to provide a technology capable of preventing such a situation. The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[0005]

Among the inventions disclosed in the present application, a brief description will be given to the outline of typical ones.
It is as follows. That is, the present invention includes a first substrate and a second substrate.
A liquid crystal display device having a liquid crystal layer sandwiched between the first substrate and the second substrate, wherein static electricity flows into at least one of the side surfaces along the direction intersecting the display surfaces of the first and second substrates. It is characterized in that a protective film for preventing the above is provided. The protective film is formed on the sealing material and is provided on the side surfaces of the first substrate and the second substrate on the side where the injection port closed by the sealing material is provided. In this case, the protective film is preferably made of the same material as the sealing material. The first substrate has terminal portions provided on respective peripheral portions along two sides intersecting with each other, and the protective film is formed on the other two side sides facing the two sides on which the terminal portions are formed. Is provided on one or both sides of the.

Semiconductor chips for driving the respective pixels are mounted on the peripheral portions of the two sides of the first substrate where the terminal portions are provided, and one of the semiconductor chips displays an image on the respective pixels. The protective film is a semiconductor chip that supplies a video signal voltage, and the protective film is provided on another side facing one side on which the semiconductor chip that supplies the video signal voltage is mounted on each pixel.
It is provided on the side surface on the side. Further, the present invention is a liquid crystal display device having a liquid crystal layer sandwiched between a first substrate and a second substrate, wherein the first substrate is provided on a surface facing the liquid crystal layer. A plurality of signal lines, the first and second
Among the side surfaces of the substrate along the direction intersecting the display surface, a protective film is provided on at least one of the side surfaces where the signal line is exposed. In addition, this protective film is
Composed of UV curable resin.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In all the drawings for explaining the embodiments, the same reference numerals are given to those having the same function, and the repeated description thereof will be omitted. [Embodiment 1] <Basic configuration of an example of a liquid crystal display module of a TFT system to which the present invention is applied> FIG. 1 is a TFT to which the present invention is applied.
It is an exploded perspective view showing a schematic structure of an example of a liquid crystal display module (LCM) of a system. The liquid crystal display module shown in FIG. 1 is a small liquid crystal display module used in a mobile phone. In the figure, the liquid crystal display panel 5 is provided with a pixel electrode, a thin film transistor (TFT), etc.
An FT substrate and a filter substrate on which a counter electrode, a color filter, etc. are formed are superposed with a predetermined gap therebetween, and a sealing material provided in a frame shape in the vicinity of a peripheral portion between the two substrates,
Both substrates are bonded together, liquid crystal is sealed and sealed inside the sealing material between both substrates from the liquid crystal sealing port provided in a part of the sealing material, and a polarizing plate is bonded on the outside of both substrates. To be done. The number of pixels of the liquid crystal display panel 5 is 128 × 160 × 3 in color display.

Here, on the glass substrate of the TFT substrate,
A drain driver (ICd) including a semiconductor chip (IC) and a gate driver (ICg) are mounted. Driving power, display data, and control signals are supplied to the drain driver (ICd) from the flexible printed wiring board 30, and the gate driver (ICg) is
Driving power and control signals are supplied from the flexible printed wiring board 30. A backlight unit is arranged on the rear side (or the side opposite to the display surface) of the liquid crystal display panel 5. A light blocking tape 31 is arranged between the backlight unit and the liquid crystal display panel 5. The backlight unit includes an upper prism sheet 32, a lower prism sheet 33, a diffusion sheet 34, an LED reflection tape 3
5, light guide plate 36, white light emitting diode (LED) 37,
The reflection sheet 38 and the flexible printed wiring board 30 are configured by being fitted in a frame-shaped mold 44 having side walls in the order shown in FIG. A plurality of light emitting diodes 37 are arranged on the side surface of the light guide plate 36, and the light shielding tape 31 and the LED reflecting tape 35 are arranged such that the light emitted from the light emitting diodes 37 is an effective display area of the liquid crystal display panel 5 (one point in FIG. 1). It is provided in order to prevent leakage from areas other than the rectangular area indicated by the chain line).

FIG. 2 shows the T of the liquid crystal display panel 5 shown in FIG.
It is a conceptual diagram for explaining the drain signal line (D) and the gate signal line (G) formed on the FT substrate. Generally, in manufacturing the TFT type liquid crystal display panel 5,
If the size is small, in order to improve the throughput, a plurality of devices are processed at the same time on one glass substrate and then divided, and the TFT substrate and the color filter substrate are pasted with a sealing material, and then a predetermined size is obtained. The glass substrate is cut. FIG. 2 shows only the drain signal line (D) and the gate signal line (G) formed on the glass substrate (TFT substrate) before cutting, and other configurations (for example, a gate insulating film). , A protective film, a pixel electrode, a thin film transistor (TFT), an alignment film, etc.) are not shown. In FIG. 2, 50 is a glass substrate before cutting, 5
Reference numeral 1 denotes a drain driver (ICd) mounting position, 52 denotes a gate driver (ICg) mounting position, and 53.
Represents a sealing material forming position, and 54 represents a sealing port forming position.

As shown in FIG. 2, the drain signal line (D)
One end of the gate signal line (G) and one end of the gate signal line (G) are cut off with the common wiring (S) formed on the glass substrate.
H). The common line (SH) may have a thin film transistor (TFT) breakdown or a threshold voltage (Vth) of the thin film transistor (TFT) that is destroyed by static electricity generated during the manufacturing process of the TFT substrate, for example, rubbing treatment of the alignment film. It is provided to prevent fluctuation. As described above, after the predetermined manufacturing process is completed, the glass substrate 50 shown in FIG. 2 and the glass substrate (not shown) on the color filter substrate side are formed at the position 53 in FIG. And then cut along the wavy lines (AA ', BB', CC ', DD') shown in FIG.

FIG. 3 is a top plan view of the completed liquid crystal display panel. In FIG. 3, 61 indicates a sealing material,
Reference numeral 62 denotes a sealing port formed in the sealing material 61, and
Reference numeral 63 indicates a sealant that covers the sealing port 62. 4 is a cross-sectional view of an essential part showing a cross-sectional structure of the liquid crystal display panel 5 shown in FIG. 3 on the side where the sealing opening 62 is formed, and FIG. 5 shows the liquid crystal display panel 5 shown in FIG. It is the figure seen from the arrow (A1) shown. In FIG. 4, the glass substrate (SUB
1, SUB2), the sealing material 61, and the drain signal line (D) are illustrated, and other configurations (for example, a gate signal line (G), a gate insulating film, a protective film, a pixel electrode, a thin film transistor (TFT), Illustration of an alignment film etc. is omitted. Although only four drain signal lines (D) are shown in FIG. 5, a predetermined number of drain signal lines (D) are actually formed. As shown in FIGS. 4 and 5, in the conventional liquid crystal display panel 5, the injection port 62 of the liquid crystal display panel 5 is used.
Of the drain signal line (D) on the side where
In the drain signal line (D), the drain driver (I
The end portion on the side not connected to Cd) is extended to the outside of the sealing material 61 and is exposed to the outside. Therefore, in the conventional liquid crystal display panel 5, static electricity flows into the inside of the liquid crystal display panel 5 from the end of the drain signal line (D) on the side where the injection port 62 is formed via the drain signal line (D). The threshold voltage (V
th) fluctuates or a thin film transistor (TF
There was a problem that T) was destroyed.

<Characteristics of the TFT type liquid crystal display module of the present invention> FIG. 6 is a top plan view of the liquid crystal display panel of the embodiment of the present invention, and FIG. 7 is a filling port in the liquid crystal display panel 5 shown in FIG. It is a principal part sectional view which shows the sectional structure of the side in which 62 is formed. Note that, also in FIG. 6, the glass substrate (S
UB1, SUB2), the sealing material 61, and the drain signal line (D) only are shown, and other configurations (for example, a gate signal line (G), a gate insulating film, a protective film, a pixel electrode,
Illustration of thin film transistors (TFTs), alignment films, etc. is omitted. As shown in FIGS. 6 and 7, in the liquid crystal display panel 5 of the present embodiment, the side surface where the sealing port 62 is formed is covered with the protective film 65. Therefore, in the liquid crystal display panel 5 of the present embodiment, the injection port 62 of the liquid crystal display panel 5 is used.
Since the end portion of the drain signal line (D) on the side where is formed is covered with the protective film 65, it is not exposed to the outside. Therefore, in the liquid crystal display panel 5 of the present embodiment, the injection port 6
From the end of the drain signal line (D) on the side where 2 is formed,
Since the static electricity does not flow into the liquid crystal display panel 5, the threshold voltage (Vth) of the thin film transistor (TFT) changes as in the conventional liquid crystal display panel 5.
Alternatively, the thin film transistor (TFT) is not destroyed.

The protective film 65 can be made of the same material as the encapsulant 63, and the protective film 65 can be made of synthetic resin such as ultraviolet curable resin or epoxy resin. Further, in FIG. 6, the drain signal line (D)
In the embodiment in which the present invention is applied to the liquid crystal display panel 5 having a structure in which only the end portion on the side not connected to the drain driver (ICd) is extended to the outside of the sealing material 61, the rain signal line ( D), the end not connected to the drain driver (ICd), and the gate driver (I) in the gate signal line (G).
Both of the ends on the side not connected to Cg) have the sealing material 61.
If the liquid crystal display panel 5 is extended to the outside of FIG.
As shown in, the drain driver (ICd) in the drain signal line (D) in the side surface of the liquid crystal display panel 5.
End not connected to the gate and the gate signal line (G)
In the above, the two side surfaces on the side where the end portion on the side not connected to the gate driver (ICg) is exposed may be covered with the protective film 65.

In the above description, the case where the present invention is applied to the small liquid crystal display panel 5 has been described, but the present invention can also be applied to the large liquid crystal display panel 5 as shown in FIG. Is possible. FIG. 9 is an exploded perspective view showing a schematic configuration of another example of a TFT type liquid crystal display module (LCM) to which the present invention is applied. The liquid crystal display module shown in FIG. 9 includes a frame-shaped frame (upper case) 4 made of a metal plate, a liquid crystal display panel 5, and a backlight unit. The liquid crystal display panel 5 is similar to FIG.
A TFT substrate on which pixel electrodes, thin film transistors (TFTs) and the like are formed, and a filter substrate on which counter electrodes and color filters and the like are formed are superposed with a predetermined gap therebetween.
A sealing material provided in the shape of a frame in the vicinity of the peripheral portion between the two substrates bonds the two substrates together, and liquid crystal is sealed inside the sealing material between the two substrates from a liquid crystal sealing port provided in a part of the sealing material. It is configured by sealing and then attaching a polarizing plate to the outside of both substrates.

A plurality of drain drivers and gate drivers composed of semiconductor integrated circuit devices (ICs) are mounted on the glass substrate of the TFT substrate. The drain driver is supplied with drive power, display data and control signals via the flexible printed wiring board 1, and the gate driver is supplied with drive power and control signals via the flexible printed wiring board 2. .
These flexible printed wiring boards (1, 2) are connected to a drive circuit board 3 provided behind the backlight unit. Further, the liquid crystal display panel 5 equipped with a plurality of drain drivers and gate drivers is
It is configured to be housed between a frame 4 having a display window and a backlight unit. The backlight unit is
The cold cathode fluorescent lamp 16, the wedge-shaped (sideways trapezoidal) light guide 9, the diffusion sheet (6, 8), the prism sheet 7, and the reflection sheet 10 have side walls in the order shown in FIG. It is configured by being fitted in a mold 14 formed in a shape of a circle. In FIG. 9, 11 is a rubber bush, 12 is a connector, and 18 and 19 are cables. Although the invention made by the present inventor has been specifically described based on the above-described embodiment, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. Of course,

[0016]

The effects obtained by the typical ones of the inventions disclosed in the present application will be briefly described as follows. According to the liquid crystal display device of the present invention, it becomes possible to prevent static electricity from flowing into the inside of the liquid crystal display panel from the end portion of the signal line exposed to the outside.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a schematic configuration of an example of a TFT type liquid crystal display module (LCM) to which the present invention is applied.

FIG. 2 is a conceptual diagram for explaining a drain signal line (D) and a gate signal line (G) formed on the TFT substrate of the liquid crystal display panel shown in FIG.

FIG. 3 is a top plan view of a completed liquid crystal display panel.

4 is a cross-sectional view of an essential part showing the cross-sectional structure of the liquid crystal display panel shown in FIG. 3 on the side where a sealing port is formed.

5 is a view of the liquid crystal display panel shown in FIG. 3 viewed from an arrow (A1) 1 shown in FIG.

FIG. 6 is a top plan view of the liquid crystal display panel according to the embodiment of the present invention.

7 is a cross-sectional view of an essential part showing the cross-sectional structure of the liquid crystal display panel shown in FIG. 6 on the side where a sealing port is formed.

FIG. 8 is a top plan view of a modification of the liquid crystal display panel according to the embodiment of the present invention.

FIG. 9 is an exploded perspective view showing a schematic configuration of another example of a TFT type liquid crystal display module (LCM) to which the present invention is applied.

[Explanation of symbols]

1, 2, 30 ... Flexible printed wiring board, 3 ... Drive circuit board, 4 ... Frame, 5 ... Liquid crystal display panel, 6,
8, 34 ... Diffusion sheet, 7, 32, 33 ... Prism sheet, 9, 36 ... Light guide member, 10, 38 ... Reflection sheet, 11
... rubber bush, 12 ... connector, 14,44 ... mold, 16 ... cold cathode fluorescent lamp, 18,19 ... cable, 35
… LED reflective tape, 37… White light emitting diode (LE
D), 51 ... Mounting position of drain driver (ICd),
52 ... Gate driver (ICg) mounting position, 53 ... Sealing material forming position, 54 ... Enclosing port forming position, 61 ... Sealing material, 62 ... Enclosing port, 63 ... Sealing agent, 65 ... Protective film,
SUB1, SUB2 ... Glass substrate, D ... Drain signal line, G ... Gate signal line, ICd, ICg ... Semiconductor chip, SH ... Common wiring.

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2H089 KA17 LA41 NA37 NA44 QA10                       QA16 TA02 TA07                 2H092 GA40 GA50 GA60 JA24 JB22                       JB31 NA25 PA04 PA13

Claims (7)

[Claims] 1. A first substrate, a second substrate, and a liquid crystal layer sandwiched between the first substrate and the second substrate, wherein the first substrate or the first substrate is provided. A liquid crystal display device in which a display surface is a surface opposite to a surface of the second substrate facing the liquid crystal layer, the liquid crystal display device being along a direction intersecting the display surfaces of the first and second substrates. A liquid crystal display device comprising a protective film on at least one of its side surfaces. 2. A sealing material, which is provided between the peripheral portions of the first and second substrates and forms a space in which a liquid crystal is sealed, the sealing material comprising the first substrate and the first substrate. 2 has an injection port for injecting liquid crystal between main surfaces of the substrate, the injection port is closed with a sealing material, and the protective film is at least the first side on the side where the sealing material is provided. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is provided on side surfaces of the first substrate and the second substrate. 3. The liquid crystal display device according to claim 2, wherein the protective film is made of the same material as the sealing material. 4. The first substrate has terminal portions provided on respective peripheral portions along two sides intersecting with each other on a surface facing the liquid crystal layer, and the protective film has the terminal portion. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is provided on at least one of the side surfaces on the side of the other two sides facing the two sides on which the two are formed. 5. A semiconductor chip for driving each of the pixels is mounted on a peripheral portion of two sides of the first substrate where the terminal portion is provided, and one of the semiconductor chips displays an image on each of the pixels. It is a semiconductor chip that supplies a video signal voltage to be displayed, and the protective film is provided on a side surface on another side facing one side on which the semiconductor chip that supplies the video signal voltage to each pixel is mounted. The liquid crystal display device according to claim 4, wherein the liquid crystal display device is a liquid crystal display device. 6. A first substrate, a second substrate, and a liquid crystal layer sandwiched between the first substrate and the second substrate, wherein the first substrate or the first substrate is provided. A liquid crystal display device, wherein a display surface is a surface opposite to a surface of the second substrate facing the liquid crystal layer, wherein the first substrate has a plurality of signal lines on a surface facing the liquid crystal layer. A protective film is provided on at least one of the side surfaces of the first and second substrates along the direction intersecting the display surface, the side surface exposing the signal line. Liquid crystal display device. 7. The liquid crystal display device according to claim 1, wherein the protective film is made of an ultraviolet curable resin.