JP5472895B2 - Liquid crystal display - Google Patents

Description

The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device in which a plurality of electrostatic protection switching elements are formed in a non-display region formed around a display region.

In general, liquid crystal display devices are characterized by thinness, light weight, and low power consumption. In particular, active matrix liquid crystal display devices using thin film transistors (TFTs) as switching elements are used in mobile phones and portable terminals for large televisions. Widely used. However, in the liquid crystal display device, when static electricity enters the display area during the manufacturing process or during use, a display defect occurs when the liquid crystal display device is completed. Especially in small and medium-sized models, static electricity defects are more likely to occur as the resolution becomes higher. Static electricity is generated only by contact with other objects in the manufacturing process and when the panel is transported. Further, when the alignment film is rubbed, static electricity is most likely to occur due to friction. Therefore, in the manufacturing technical field of liquid crystal display devices, it is required to prevent display defects due to static electricity.

In order to prevent the occurrence of such pixel defects due to static electricity, Japanese Patent Application Laid-Open No. 2004-151867 discloses that dummy pixels are formed in the periphery of the display area, and a plurality of minute dummy pixels for electrostatic protection are formed in the dummy pixels. An invention of a liquid crystal display device in which an electrode and a switching element are formed is disclosed. Here, the configuration of the dummy pixel portion of the liquid crystal display device disclosed in Patent Document 1 below will be described with reference to FIGS.

FIG. 8 is an enlarged plan view of the dummy pixel region of the array substrate disclosed in Patent Document 1 below. FIG. 9 is an enlarged plan view of a portion IX in FIG. 10 is a cross-sectional view taken along line XX of FIG.

The liquid crystal display device 50 of the conventional example is a transflective liquid crystal display device, and a plurality of scanning lines and signal lines provided in a matrix with a gate insulating film interposed therebetween are provided on a first translucent substrate 51. ing. In FIG. 8, scanning lines Xn-2, Xn-1, Xn, Xn + 1, Xn are used as scanning lines.
Only the portion of +2, and only the portions of Y1, Y2,... Ym are shown as signal lines. Among these, the area surrounded by the plurality of scanning lines X1, X2... Xn and the signal lines Y1, Y2... Ym is a display area, and the plurality of scanning lines Xn, Xn + 1, Xn + 2 and the signal lines Y1, Y2 are.・ ・
The area surrounded by Ym is a non-display area.

In this display area, a pixel electrode 52 and a reflecting plate 65 contributing to display are provided for each area surrounded by each scanning line and signal line. In the TFT 54, the source electrode S is connected to the signal lines Y1, Y2,... Ym, and the gate electrode G is connected to the scanning lines X1, X2,.
The drain electrode D is electrically connected to the pixel electrode 52 and the reflection plate 65 through a contact hole (not shown). In addition, an auxiliary capacitance electrode 53 is provided below the drain electrode D. The operation principle of the liquid crystal display device 50 having such a configuration is as follows.
Since it is already known, its detailed description is omitted.

On the other hand, a non-display area surrounded by scanning lines Xn, Xn + 1, Xn + 2 and signal lines Y1, Y2,... Ym is formed around the display area of the liquid crystal display device 50. In this non-display area, T
A plurality of dummy pixels each having an FT 66 and a dummy pixel electrode 67 that does not contribute to display are provided for each signal line Y1, Y2,. The source electrode S of the TFT 66 of the dummy pixel is connected in parallel for each signal line Y1, Y2,... Ym, the gate electrode G is connected in parallel for each scanning line Xn + 1, Xn + 2, and the drain electrode D is further connected. As shown in FIG. 10, it is connected to a dummy pixel electrode 67 provided on the interlayer film 69 through a contact hole 68. The TFT 66 of the dummy pixel is smaller than the channel width and channel length of the TFT 64 connected to the pixel electrode 52 contributing to display, and thereby the TFT 54 connected to the pixel electrode 52 contributing to display. It is designed to be preferentially destroyed by electrostatic discharge.

The area of the dummy pixel electrode 67 is the pixel electrode 5 that contributes to the display of one pixel in the display region.
2 and the area of the reflecting plate 65 are made smaller. 8 and 9, each area of the dummy pixel electrode 67 is set to 1/10 of the area of the pixel electrode 52 and the reflecting plate 65 contributing to display for one pixel in the display region, and the scanning lines Xn and Xn + 1 are used. A total of 20 units are shown, 10 units between each of Xn + 1 and Xn + 2 respectively.

In the liquid crystal display device 50 having such a configuration, when static electricity enters from the signal line input terminal 62, the TFT 661 in the dummy pixel region closest to the signal line input terminal 62 causes electrostatic breakdown to discharge the static electricity. After that, when static electricity enters from the signal line input terminal 62 again, the TFT 662 adjacent to the TFT 661 in the dummy pixel region that first caused the electrostatic breakdown discharges the static electricity. For this reason, in the manufacturing process of the liquid crystal display device 50, since the static electricity approach that destroys the thin film transistor 54 in the display region can be allowed up to 20 times, a transflective type in which display defects do not substantially occur. The liquid crystal display device 50 is obtained.
JP 2006-276590 A

However, the dummy pixels shown in the liquid crystal display device 50 disclosed in Patent Document 1 are formed in non-display areas on the upper and lower sides of the display area in plan view. Therefore, in the non-display area on the upper and lower sides of the display area in a plan view, a plurality of dummy pixels are formed in the area for one pixel, so that it is possible to cope with a plurality of static electricity ingresses from the signal line side. it can.
However, in the non-display area on the left and right sides of the display area in a plan view, it is difficult to form a plurality of dummy pixels in the area for one pixel, so that it is possible to cope with a plurality of electrostatic intrusions from the scanning line side. In order to do this, it is necessary to form a plurality of dummy pixels outward on both the left and right sides of the display area in plan view. Therefore, it is difficult to reduce the width of the non-display area on the left and right sides of the display area in plan view. In addition, the liquid crystal display device 50 disclosed in Patent Document 1 above.
The dummy pixel shown in FIG. 1 has a complicated structure because it includes the TFT 66 and the dummy pixel electrode 67.

The present invention has been made to solve the above-described problems of the prior art. That is, according to the present invention, it is possible to form a plurality of electrostatic protection elements having a simple configuration in the area corresponding to one pixel in all the non-display areas, and without increasing the width of the non-display area. An object of the present invention is to provide a liquid crystal display device that can cope with a large number of static electricity ingresses .

In order to achieve the above object, a liquid crystal display device of the present invention has a first substrate and a second substrate that are arranged to face each other with a liquid crystal layer interposed therebetween, and the liquid crystal layer side of the first substrate has a matrix shape. A plurality of scanning lines and signal lines arranged, a thin film transistor arranged in the vicinity of the intersection of each scanning line and signal line in the display area, and a pixel area surrounded by each scanning line and signal line in the display area In a liquid crystal display device in which a pixel electrode electrically arranged to each of the thin film transistors and a non-display area is formed around the display area, the liquid crystal display device is arranged in a matrix in the non-display area . wherein the area of each pixel is surrounded by the scanning lines and the signal lines, the bent portion is formed on the scanning line or the signal line, the plurality of thin film transistors along the bent portion is formed, the pixel Wherein the plurality of thin film transistors formed on the region drain electrodes of the thin film transistor is connected in parallel with each other is that is connected to a common potential.

In the liquid crystal display device of the present invention, a plurality of thin film transistors as electrostatic protection elements are formed in a non-display area around the display area. That is, the liquid crystal display device of the present invention includes a plurality of non-display areas located on both ends in the column direction of the display area in a plan view and non-display areas located on both ends in the row direction of the display area in a plan view. of the thin film transistor is formed, a thin film transistor of the multiple is connected in parallel with each other, the drain electrodes of the thin film transistor is connected to a common potential. Incidentally, may form a dummy pixel electrode in the non-display area, connecting the dummy pixel electrode, connected to the drain electrode of the thin film transistor through a contact hole formed in the insulating layer, the drain electrode of the thin film transistor to the common potential May be used to

In addition, in the liquid crystal display device of the present invention, since the scanning line or the signal line is formed with a bent portion, the length of the scanning line or the signal line positioned in the non-display area is long. Therefore, since the area occupied by the thin film transistors is smaller than the area for one pixel, many thin film transistors can be formed in the non-display region.

In addition, since the plurality of thin film transistors are connected to the scanning lines or signal lines, they are formed side by side along the scanning lines or signal lines. Moreover, since the drain electrodes of the plurality of thin film transistors are connected to a common potential, when static electricity to the scan line or signal line enters, the electrostatic breakdown from TFT near the entry point of the static electricity in order, the static electricity is common Since the electric potential is discharged to discharge, the display area of the liquid crystal display device can be effectively protected. In addition, since the entrance of static electricity is allowed until all of the plurality of thin film transistors are electrostatically destroyed, a liquid crystal display device can be obtained in which display defects are not substantially caused by increasing the number of thin film transistors .

The present invention is not limited to a vertical electric field liquid crystal display device such as a TN (Twisted Nematic) mode, a VA (Vertical Alignment) mode, and an ECB (Electrically Controlled Birefringence) mode, but also an IPS (In-Plane Switching) mode, The present invention can also be applied to a horizontal electric field type liquid crystal display device such as an FFS (Fringe Field Switching) mode. Further, as a switching element which can be used in the present invention, a thin film transistor (TFT: Thin Film Transistor) Besides, the thin-film diode (Thin Film Diode), may be used a MIM (Metal Insulator Metal) element or the like.

In the liquid crystal display device of the present invention, it is preferable that the thin film transistor formed in the non-display region has substantially the same size as the thin film transistor formed in the pixel region.

If the thin film transistor formed in the non-display region is approximately the same size as the thin film transistor formed in the pixel region, it is not particularly necessary to cause a mask for forming the thin film transistor in the non-display region, and the thin film transistor of the liquid crystal display device It can be formed at the same time as forming. Therefore, the liquid crystal display device of the present invention can be easily manufactured even though it includes a plurality of thin film transistors in the non-display area. The “substantially the same size” in the present invention is not necessarily the same size, but is used in the sense that the same size is preferable.

In the liquid crystal display device of the present invention, a bent portion is formed in the scanning line in the non-display region, and a branch signal line extending along an outer periphery of the bent portion of the scanning line is formed in the signal line. It is preferable that

In the liquid crystal display device of the present invention, since the length of the scanning line in the non-display area can be increased, a plurality of thin film transistors can be easily formed in the non-display area regardless of the width in the row direction of the non-display area. Can be formed. Therefore, according to the liquid crystal display device of the present invention, a plurality of thin film transistors can be formed along the scanning line without widening the width of the non-display area on the left and right sides of the display area in plan view. Even if the width of the non-display area on the left and right sides of the display area is narrow, the display area of the liquid crystal display device can be effectively protected. As a scanning line bending mode, the shape of the pixel in the display area is usually formed in a rectangular shape with a short side on the scanning line side, so that it is convex or concave in the non-display area on the left and right sides of the display area in plan view. Are preferably bent. If a rectangular shape is oblong pixels in the display area, scan lines are preferably bent in zigzag in the "U" shape in the non-display area of the left and right side of the display region in plan view. In any case, when the scanning line is bent, the signal line may be formed as a branched signal line extending along the outer periphery of the bent portion of the scanning line.

In the liquid crystal display device of the present invention, a bent portion is formed in the signal line in the non-display region, and a branch scanning line is formed so that the scanning line extends to intersect the bent portion of the signal line. It is preferable.

Since the liquid crystal display device of the present invention can increase the length of the signal line in the non-display area, the distance between the scanning lines of the non-display area on the upper and lower sides of the display area is reduced in plan view as in the conventional example. Even if not, a plurality of thin film transistors can be formed along the signal line. Therefore, according to the liquid crystal display device of the present invention, a large number of thin film transistors can be formed without increasing the width of the non-display region on the upper and lower sides of the display region in plan view. To be able to protect. Note that the signal line is bent in a non-display area on the upper and lower sides of the display area in a plan view since the pixel shape of the display area is usually formed in a rectangular shape with a long side on the signal line side. It is preferable to bend in a zigzag shape. When the shape of the pixel in the display area is a horizontally long rectangular shape, it is desirable that the signal line bends in a convex or concave shape in a non-display area on the upper and lower sides of the display area in plan view. In any case, the scanning line may extend in a branch shape so as to intersect the bent portion of the signal line.

In the liquid crystal display device of the present invention, TFT that is formed before Symbol non-display region is connected to the source electrode, each said signal line is connected with the gate electrode to the scanning line, the drain electrode and the common It is preferably connected to a potential.

The TFT is generally used as a switching element of a liquid crystal display device.
Therefore, according to the liquid crystal display device of the present invention, the switching elements in the display area and the switching elements in the non-display area are made of TFTs, so that these switching elements can be manufactured simultaneously and easily. .

Furthermore, in the liquid crystal display device of the present invention, the TFT formed in the non-display area is
It is preferable that the channel width and channel length of the TFT formed in the display region are smaller.

If the channel width and channel length of the TFT formed in the non-display area are smaller than those of the TFT formed in the display area, electrostatic breakdown is more likely to occur. Therefore, according to the liquid crystal display device of the present invention, even if static electricity enters from the outside, the TFT formed in the non-display area surely breaks down first, so that static electricity does not easily enter the display area. Thus, the display area of the liquid crystal display device can be effectively protected.

Hereinafter, the best mode for carrying out the present invention will be described with reference to the embodiment and the drawings.
The embodiments described below are not intended to limit the present invention to those described herein, and the present invention has been variously modified without departing from the technical idea shown in the claims. It can be applied equally. In each drawing used for the description in this specification, each layer and each member are displayed in different scales so that each layer and each member can be recognized on the drawing. However, it is not necessarily displayed in proportion to the actual dimensions.

FIG. 1 is a schematic plan view showing an array substrate of the liquid crystal panel of the embodiment. FIG. 2 is an enlarged plan view of a portion II in FIG. FIG. 3 is an enlarged plan view of one sub pixel in the display area of FIG. FIG.
FIG. 4 is a sectional view taken along line IV-IV in FIG. 3. FIG. 5 is an enlarged plan view of an area corresponding to one pixel in the non-display area on the left and right sides of the display area in FIG. 6 is a sectional view taken along line VI-VI in FIG. FIG. 7 is an enlarged plan view of an area corresponding to one pixel of the non-display area on the left and right sides of the display area of the modification.

[Embodiment]
A liquid crystal panel 10 according to an embodiment will be described with reference to FIGS. In the liquid crystal panel 10 according to the embodiment, as shown in FIG. 4, the liquid crystal layer LC is sandwiched between the array substrate AR and the color filter substrate CF. The thickness of the liquid crystal layer LC is uniformly maintained by columnar spacers (not shown). Further, polarizing plates (not shown) are respectively formed on the back surface of the array substrate AR and the front surface of the color filter substrate CF. Light is irradiated from the back side of the array substrate AR by a backlight (not shown).

As shown in FIG. 1, the array substrate AR includes a display area DA on which various images are displayed and a non-display area ND that is a periphery of the display area DA, and one end side of the non-display area ND. A first terminal portion Dr for mounting the driver IC and a second terminal portion Tp for external connection are formed. In the non-display area ND, the scanning line routing wiring GL for routing the scanning line of the display area DA to the first terminal portion Dr and the signal line routing wiring S for routing the signal line to the first terminal portion Dr.
L is provided. In the non-display area ND, a common wiring line COM for routing the auxiliary capacitance line 13 (see FIGS. 3 and 4) to the first terminal portion Dr is also formed.

Among these, electrostatic protection means against static electricity that has entered from the signal line routing wiring SL side is formed in the non-display areas on the upper and lower sides of the display area, and the scanning line routing wiring GL is formed in the non-display areas on the left and right sides of the display area. An electrostatic protection means against static electricity entering from the side is formed. In addition, the corners between the upper and lower non-display areas and the left and right non-display areas of the display area are provided with electrostatic protection means against static electricity that has entered from both sides of the signal line routing line SL and the scanning line routing line GL. Is formed. Although the detailed configuration of these electrostatic protection means will be described later, in the present invention, the configuration of the electrostatic protection means in all the areas for one pixel can be made the same. The electrostatic protection means in one pixel area will be described.

First, the configuration of the array substrate AR will be described in the order of the manufacturing process. The array substrate AR is shown in FIG.
As shown in FIG. 4, the liquid crystal LC of the first substrate 11 made of glass, quartz, plastic, or the like.
On the side, a plurality of scanning lines 12 made of an opaque metal such as an aluminum metal, an aluminum alloy, and molybdenum, and an auxiliary capacitance line formed in parallel between the scanning lines 12 (acting as an auxiliary capacitance electrode having a wide width) 13) and a common wiring line COM formed in the non-display area ND. Among these, the scanning line 12 and the auxiliary capacitance line (including a portion acting as an auxiliary capacitance electrode having a wide width) 13 are formed not only in the display area DA but also in the non-display area ND.

In the liquid crystal display device 10 of this embodiment, in order to increase the aperture ratio, the auxiliary capacitance line 13 is
It is formed along the scanning line 12 side. In addition, when the scanning lines 12 and the like are formed, a plurality of gate wirings extending toward the first terminal portion Dr are formed in the scanning line routing wiring GL portion of the non-display area ND, and the signal line routing wiring is also the first. A plurality of gate wirings extending toward the terminal portion Dr are formed (not shown).

In the non-display area ND, as shown in FIGS. 2 and 5, the shape of the area for one pixel is the short side on the scanning line 12 side as in the case of the area for one pixel of the display area DA. Therefore, the scanning line 12 is bent into a convex bent shape. These scanning lines 12, auxiliary capacitance lines 13, gate lines and common lines COM are formed by forming an opaque metal layer such as aluminum metal, aluminum alloy, molybdenum over the entire surface of the first substrate 11, and then applying the spin coating method. The resist is applied by, and after performing exposure and development processing so as to form a predetermined pattern, the unnecessary portion is etched. The auxiliary capacitance line 13 in the area corresponding to one pixel of the non-display area ND is formed in a solid shape at the center,
The scanning line 12 in the area corresponding to one pixel in the non-display area ND bypasses the surface of the scanning line 12 via a separate insulating film, and is electrically connected to the storage capacitor line 13 in the display area DA. Thereafter, a gate insulating film 14 made of an inorganic insulating film such as silicon oxide or silicon nitride is formed so as to cover the scanning lines 12, gate wirings, auxiliary capacitance lines 13, and exposed surfaces of the first substrate 11.

Next, a semiconductor layer 15 made of, for example, amorphous silicon is formed on the gate insulating film 14. This semiconductor layer 15 is also unnecessary after an amorphous silicon layer is formed over the entire surface of the gate insulating film 14, a resist is applied by a spin coating method, and exposure and development processes are performed to form a predetermined pattern. It is produced by etching a part. The semiconductor layer 15 is formed not only in the display area DA but also in a switching element formation scheduled portion in the non-display area ND.

Next, a first contact hole 19 ′ is formed in the gate insulating film 14 in a portion where the drain electrode formation scheduled portion of the TFT in the non-display region ND and the auxiliary capacitance line 13 are opposed to each other. after that,
A source electrode S and a drain electrode D are formed so as to partially run over the semiconductor layer 15. In the liquid crystal display device 10 of this embodiment, in the display area DA, the semiconductor layer 15 is disposed to face a portion where the width of the scanning line 12 is partially widened via the gate insulating film 14. The portion overlapping with 12 in plan view constitutes the gate electrode G of the TFT. The source electrode S is a portion branched from the signal line 16. The signal line 16 and the drain electrode D are
Each is formed of an opaque metal such as an aluminum metal, an aluminum alloy, or molybdenum, and is formed not only in the display area DA but also in the non-display area ND. Therefore, the non-display area ND
The portion of the drain electrode D formed in the region corresponding to one pixel is electrically connected to the auxiliary capacitance line 13 through the contact hole 19 ′.

Further, a branched signal line 16 ′ partially branched from the signal line 16 is formed, and this branched signal line 16 ′ extends along the periphery of the bent scanning line 12. Further, when the signal line 16 and the drain electrode D are formed, a plurality of source wirings extending toward the first terminal portion Dr are formed in the scanning line routing wiring GL in the non-display region ND, and the signal line routing wiring SL is formed. Similarly, a source wiring extending toward the first terminal portion Dr is formed (not shown).
. Note that the gate wiring and the source wiring in the present invention are not necessarily the scanning lines 12 of the liquid crystal panel.
It does not mean a wiring connected to the signal line 16, a wiring formed simultaneously with the scanning line 12 is called a gate wiring, and a wiring formed simultaneously with the signal line 16 is called a source wiring. Therefore, in the liquid crystal display device 10 of the above embodiment, the wiring portion under the gate insulating film 14 becomes the gate wiring, the wiring portion above the gate insulating film 14 becomes the source wiring,
There is no distinction between the two in plan view.

Then, both the display area DA and the non-display area ND are covered with silicon oxide or silicon nitride so as to cover the semiconductor layer 15, the source electrode S, the drain electrode D, the signal line 16, the source wiring, etc. and the exposed portion of the gate insulating film 14. A passivation film 17 made of an inorganic insulating film is formed.
Further, in the display area DA, an interlayer film 18 made of a resin material is formed so as to cover the passivation film 17. As the interlayer film 18, a photosensitive resist material having good transparency and excellent electrical insulation can be appropriately selected and used. The interlayer film 18 is manufactured by applying a resist to the surface of the passivation film 17 by spin coating, performing exposure and development processes so as to form a predetermined pattern, and then etching unnecessary portions.

Next, a second contact hole 19 is formed so as to penetrate the passivation film 17 and the interlayer film 18 and reach the drain electrode D. Further, a pixel electrode 20 made of a transparent conductive material such as ITO or IZO is formed for each pixel area of the display area DA so as to cover the interlayer film 18. The pixel electrode 20 is electrically connected to the drain electrode D through the second contact hole 19. Furthermore, an alignment film (not shown) is formed so as to cover the surface of the pixel electrode 20, and the array substrate AR in the liquid crystal display device 10 of the embodiment is obtained.

Next, the color filter substrate CF will be described. The color filter substrate CF has a second substrate 21 made of glass, quartz, plastic or the like. On the second substrate 21, a color filter layer 22 and a light shielding layer 23 that transmit different colors of light (R, G, B, or colorless) for each subpixel are formed. A top coat layer 24 is formed so as to cover the color filter layer 22 and the light shielding layer 23, and ITO or IZ is covered so as to cover the top coat layer 24.
A common electrode 25 made of O is formed. An alignment film (not shown) is formed on the surface of the common electrode 25, and the color filter substrate of the liquid crystal display device 10 of the embodiment is completed.

Then, the array substrate AR and the color filter substrate CF formed as described above are arranged to face each other, the peripheral portion is sealed with a sealing material (not shown), and the liquid crystal LC is interposed between the array substrate AR and the color filter substrate CF. By sealing in the formed sealing area, the liquid crystal panel 10 of the embodiment is obtained.

Next, the configuration of an area for one pixel of the non-display area ND formed around the display area DA will be described. In the liquid crystal display device 10 of the present embodiment, the non-display area ND is formed at the upper and lower sides of the display area DA, the left and right sides of the display area DA, and the upper and lower sides and the left and right corners of the display area DA. All areas for one pixel have the same size and shape.

Then, in the liquid crystal display device 10 of the embodiment, in the non-display area of one pixel region ND, the scanning line 12 is bent so as to be elongated convex along the scanning line 12 adjacent. A branch signal line 16 ′ extends from the signal line 16 along the periphery of the bent scanning line 12 so as to occupy the adjacent signal line 16. A plurality of, in this case, twelve semiconductor layers 15 are formed on the bent scanning lines 12 via the gate insulating film 14, and the signal lines 16 and branches are partially overlapped with the semiconductor layers 15. A source electrode S is formed on the signal line 16 'side, and a drain electrode D is formed on the center side. The auxiliary capacitance line 13 in the region corresponding to one pixel of the non-display region ND is formed in a solid shape at the center, and the drain electrode D passes through the first contact hole 19 ′ formed in the gate insulating film 14. The storage capacitor line 13 is electrically connected. Note that the storage capacitor line 13 in the one-pixel region of the non-display region ND is bypassed from the surface of the scanning line 12 via an insulating film separately from the scanning line 12 bent so as to be convex, The storage capacitor line 13 in the display area DA is electrically connected.

That is, in the liquid crystal display device 10 according to the embodiment, a plurality of (herein, 6 × 2 = 12) TFTs as electrostatic protection elements (hereinafter referred to as “protection TF”) are formed in one pixel area of the non-display area ND.
T ". ) 30 is formed. These protective TFTs 30 are substantially the same in size as the TFTs formed in the display area DA in order to facilitate the formation simultaneously with the TFTs formed in the display area DA. Is smaller than that of the TFT formed in the display area DA. For this reason, the protective TFT 30 is electrostatically weaker than the TFT formed in the display area DA, so that it is electrostatically destroyed before the TFT formed in the display area DA.

As apparent from the description of FIGS. 2, 5, and 6, the gate electrode G of the protective TFT 30 is formed on the same scanning line 12 in the region corresponding to one pixel of each non-display region ND, and the source electrode S is electrically connected to the same signal line 16 or branch signal line 16 ′, and the drain electrode D is also electrically connected to the auxiliary capacitance line 13 formed in one pixel area of the same non-display area ND. It is connected to the. In other words, the plurality of protection TFTs 30 are connected in parallel to each other in the area corresponding to one pixel of each non-display area ND.

According to the protective TFT 30 having such a configuration, for example, when static electricity enters along the signal line 16 from the first terminal portion Dr or the second terminal portion Tp through the signal line routing wiring SL (see FIG. 1), The protective TFT 30 connected to the signal line 16 or the branch signal line 16 ′ closest to the first terminal portion Dr or the second terminal portion Tp is electrostatically destroyed, and the static electricity is generated in the first contact hole 19 ′, It flows through the auxiliary capacitance line 13 to the common potential and is discharged.

Similarly, even when static electricity enters along the scanning line 12 from the first terminal portion Dr to the second terminal portion Tp through the scanning line lead-out wiring GL, the first terminal portion Dr to the second terminal portion first.
The protective TFT 30 connected to the scanning line 12 at a position close to the terminal portion Tp is electrostatically broken, and the static electricity flows to the common potential through the first contact hole 19 ′ and the auxiliary capacitance line 13 and is discharged.

Therefore, according to the liquid crystal display device 10 of the present invention, even if static electricity enters from the signal line 16 side or the scanning line 12 side, the protective TFT closest to the side where static electricity has entered is electrostatically destroyed, The other protection TFT 30 and the TFT in the display area DA are protected. Such a protective operation can be continued until the protective TFT 30 closest to the display area DA is electrostatically destroyed. Therefore, by increasing the number of protective TFTs 30 connected per scanning line or per signal line, It will be able to withstand more static ingress.

[Example of change]
In the liquid crystal display device 10 of the above-described embodiment, the scanning line 1 in the region for one pixel of the non-display region ND
Although an example in which the scanning line 12 is bent to increase the length of 2 is shown, the signal line 16 can also be bent to increase the length of the signal line 16. A modified example in which the signal line 16 in the region corresponding to one pixel of the non-display region ND is bent will be described with reference to FIG.

In the region corresponding to one pixel of the non-display region ND of the modification shown in FIG. 7, the signal line 16 is bent in a “U” shape in a zigzag manner. A branch scanning line 12 ′ branched from the scanning line 12 is disposed so as to cross the signal line 16 bent in a zigzag shape in a “U” shape. Then, a protective TF having the branch scanning line 12 ′ as the gate electrode G on the branch scanning line 12 ′.
A plurality of T30s, here, eight are formed. Although the auxiliary capacitance line in the region of one pixel of the non-display area ND is not shown, it is disposed below each drain electrode D, and an insulating film is separately provided over the branch scanning line 12 ′. Through the storage capacitor line 13 of the display area DA. Note that, in the region of one pixel of the non-display region ND of this modification, the width of the branch scanning line 12 ′ branched from the scanning line 12 reduces the impedance so that all the protective TFTs 30 are effectively operated. Therefore, it is recommended to make it as thick as possible.

In addition, in the region corresponding to one pixel of the non-display region ND of this modification, the auxiliary capacitance line cannot be arranged in a solid shape so as not to increase the number of manufacturing steps. What is necessary is just to electrically connect the drain electrode D of each protection TFT 30 to the auxiliary capacitance line using a gate wiring and a source wiring as appropriate. Further, as in the case of the pixel electrode 20 in the display area DA, an interlayer film 18 and a dummy pixel electrode are formed in the area for one pixel in the non-display area ND, and this dummy pixel electrode is connected to the common wiring outside the display area. In addition to connecting to COM, a protective pixel is formed through a contact hole in which a dummy pixel electrode is formed in the interlayer film 18 and the passivation film 17.
You may electrically connect with the drain electrode D of FT30. With such a configuration, it is not necessary to form a storage capacitor line in the area corresponding to one pixel in the non-display area ND.

In the above-described embodiment, since the shape of each pixel in the display area DA is vertically long, the case where the shape of the area for one pixel in the non-display area ND is also vertically long has been described. However, when the shape of the pixel in the display area DA is a horizontally long rectangular shape, in the area corresponding to one pixel in the non-display area ND, when the scanning line is bent, it is bent in a zigzag shape. If the signal line is bent, it may be bent in a convex shape or a concave shape. In the above-described embodiment, an example in which the configuration of the electrostatic protection means in the region for all the pixels is the same has been described. However, in the left and right non-display regions ND and the upper and lower display regions ND of the display region DA. Each may have a different configuration.

In the above-described embodiment, the TN mode vertical electric field type transmissive liquid crystal display device has been described as an example. However, the present invention is not limited to this, and other modes of vertical electric field type liquid crystal display devices are also described. Alternatively, the present invention can be equally applied to a liquid crystal display device of a horizontal electric field type and also to a liquid crystal display device having a reflection portion. In particular, in the FFS mode liquid crystal display device having a lower electrode and an upper electrode having a slit on the interlayer film, the upper electrode or the lower electrode is connected to a common potential, so the configuration of the above modification is adopted. However, the drain electrode D of the protection TFT 30 can be easily connected to the common potential without increasing the number of manufacturing steps.

It is a schematic plan view which shows the array board | substrate of the liquid crystal panel of embodiment. It is an enlarged plan view of the II part of FIG. FIG. 3 is an enlarged plan view of one sub pixel in the display area of FIG. 2. It is sectional drawing of the IV-IV line of FIG. FIG. 3 is an enlarged plan view of an area corresponding to one pixel in a left and right non-display area of the display area in FIG. 2. It is sectional drawing of the VI-VI line of FIG. It is an enlarged plan view of the area | region for 1 pixel of the non-display area | region of the right and left of the display area of a modification. It is an enlarged plan view of a dummy pixel region of an array substrate in a liquid crystal display device of a conventional example. It is an enlarged plan view of the IX part of FIG. It is sectional drawing of the XX line of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Liquid crystal display device 11 ... 1st board | substrate 12 ... Scanning line 12 '... Branch scanning line 13 ... Auxiliary capacitance line 14 ... Gate insulating film 15 ... Semiconductor layer 16 ... Signal line 16' ... Branching signal line 1
DESCRIPTION OF SYMBOLS 7 ... Passivation film 18 ... Interlayer film 19, 19 '... Contact hole 20 ... Pixel electrode 21 ... 2nd board | substrate 22 ... Color filter layer 23 ... Light-shielding layer 24 ... Topcoat layer 25 ... Common electrode 30 ... Protection TFT AR ... Array substrate CF: Color filter substrate
DA: display area ND: non-display area COM: common wiring GL: scanning line routing wiring S
L ... Signal line routing

Claims (6)

A first substrate and a second substrate are disposed opposite to each other with a liquid crystal layer interposed therebetween. On the liquid crystal layer side of the first substrate, a plurality of scanning lines and signal lines arranged in a matrix, and a display region A thin film transistor disposed near the intersection of each scanning line and signal line and a pixel area surrounded by each scanning line and signal line in the display area and electrically connected to the thin film transistor In the liquid crystal display device in which a non-display area is formed around the pixel electrode and the display area,
In the non-display area , a bent portion is formed in the scanning line or the signal line in an area surrounded by a line obtained by virtually extending the scanning line provided in the display area and the signal line. along said bent portion a plurality of thin film transistors are formed, the drain electrode of the plurality of thin film transistors formed before Symbol territory region are connected in parallel to each other said thin film transistor liquid crystal display device which is connected to the common potential.   2. The liquid crystal display device according to claim 1, wherein the thin film transistor formed in the non-display region has substantially the same size as the thin film transistor formed in the pixel region.   2. The non-display area according to claim 1, wherein the bent portion is formed on the scanning line, and the signal line is formed with a branch signal line extending along an outer periphery of the bent portion of the scanning line. Liquid crystal display device.   2. The liquid crystal according to claim 1, wherein the bent portion is formed in the signal line in the non-display region, and the scanning line is formed with a branch scanning line extending so as to intersect the bent portion of the signal line. Display device.   The thin film transistor formed in the non-display region has a source electrode connected to the signal line, a gate electrode connected to the scanning line, and a drain electrode connected to the common potential. The liquid crystal display device according to any one of the above.   The liquid crystal display device according to claim 5, wherein the thin film transistor formed in the non-display region is smaller than a channel width and a channel length of the thin film transistor formed in the display region.

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