JP5293240B2 - Display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a frame area in a liquid crystal display device having a static electricity protective thin film transistor for protecting a switching thin film transistor from static electricity. <P>SOLUTION: By disposing a static electricity protective line 31 for scanning lines, first and second static electricity protective transistors 32, 33 for scanning lines, and a connection thin film transistor 34 in a driver mounting region 11 for driving scanning lines, a region exclusive for disposing these elements is made unnecessary, and accordingly, a frame area can be reduced. By providing a static electricity protective line 41 for data lines, a static electricity protective thin film transistor 42 for data lines and first and second connection thin film transistors 43, 44 in a driver mounting region 14 for driving data lines, a region exclusive for disposing these elements is made unnecessary, and accordingly the frame area can be reduced. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a display device.

  For example, in a conventional active matrix liquid crystal display device, a plurality of scanning lines and a plurality of data provided in a matrix form are used to prevent defects such as characteristic shift and dielectric breakdown caused by static electricity of a switching thin film transistor. The scanning line electrostatic protection line, the scanning line electrostatic protection line, and each scanning line are arranged outside the display area in which a pixel electrode and a switching thin film transistor connected to the pixel electrode are provided in the vicinity of each intersection with the line. An electrostatic protection thin film transistor for scanning line provided in between, an electrostatic protection line for data line, and an electrostatic protection thin film transistor for data line provided between the data line electrostatic protection line and each data line are provided There are some (see, for example, Patent Document 1).

JP 2005-93459 A

  However, in the conventional liquid crystal display device, the scanning line electrostatic protection line, the scanning line electrostatic protection thin film transistor, the data line electrostatic protection line, and the data line electrostatic protection thin film transistor are provided outside the display area. In order to secure these arrangement regions, there is a problem that the frame area becomes large.

  Therefore, an object of the present invention is to provide a display device that can reduce the frame area.

In order to achieve the above object, the present invention provides a display area in an area where the first substrate and the second substrate overlap, and the first substrate protrudes from one side of the second substrate. A pixel electrode arranged in a matrix in the display area of the first substrate, a switching thin film transistor connected to the pixel electrode, and a scan for supplying a scanning signal to the switching thin film transistor A display device provided with a line and a data line for supplying a data signal to the switching thin film transistor, wherein the scanning line driving driver is provided on the projecting portion; An area on the protruding portion where the data line driving driver is mounted and an area where the scanning line driving driver is mounted. The electrostatic protection circuit for the scanning line, one end of which is connected to the scanning line, and the electrostatic protection for the data line, which is provided in an area where the driver for driving the data line is mounted and one end of which is connected to the data line. A circuit, a common line that surrounds the periphery of the display region, and is provided in a region where the first substrate and the second substrate overlap each other along the one side of the protruding portion. A common external connection terminal provided on the end face side and electrically connected to the common line via a lead wire, and the common line is connected to an external circuit via the common external connection terminal, The other end of the scanning line electrostatic protection circuit and the other end of the data line electrostatic protection circuit are electrically connected to the common line via a diode-connected thin film transistor. The a electrostatic protection circuit for the scan line data lines for electrostatic protection circuit each have a plurality of floating gate type thin film transistor, the electrostatic protection circuit for the scanning lines are further each electrostatic protection circuit for the scanning lines A plurality of electrostatic protection thin film transistors connected so as to correspond to any of the floating gate thin film transistors, and the scan lines and the scan lines provided in a region where the scan line driving driver is mounted In the region of the scanning output terminal that is electrically connected to the driver for driving, the first metal electric layer forming the gate electrode of the electrostatic protection thin film transistor, the drain electrode of the electrostatic protection thin film transistor, and the floating gate type Thin film transistor drain A second metal layer constituting an electrode is laminated and electrically connected to each other, and the floating gate type thin film transistor of the scanning line static electricity protection circuit and the floating gate type of the data line static electricity protection circuit The thin film transistors are arranged so as to be aligned in the same row in the direction along the one side.

According to the present invention , the frame area can be reduced.

1 is an equivalent circuit plan view of a main part of a liquid crystal display device as a first embodiment of the present invention. FIG. 2 is an equivalent circuit plan view of a scanning line electrostatic protection circuit provided in a scanning line driving driver mounting region shown in FIG. 1. FIG. 2 is an equivalent circuit plan view of a data line electrostatic protection circuit portion provided in a data line driving driver mounting region shown in FIG. 1. Sectional drawing of the part of the thin-film transistor and pixel electrode which are shown in FIG. FIG. 3 is a partial cross-sectional view of a scanning line driving driver mounting area shown in FIG. 2. FIG. 3 is a cross-sectional view of another portion in the scanning line driving driver mounting area shown in FIG. 2. FIG. 4 is a partial cross-sectional view of a data line driving driver mounting area shown in FIG. 3. Sectional drawing of the other part in the driver mounting area | region for a data line drive shown in FIG. Sectional drawing similar to FIG. 7 of the liquid crystal display device as 2nd Embodiment of this invention. Sectional drawing similar to FIG. 8 of the liquid crystal display device as the said 2nd Embodiment. The equivalent circuit top view similar to FIG. 2 of the liquid crystal display device as 3rd Embodiment of this invention. The equivalent circuit top view similar to FIG. 11 of the liquid crystal display device as 4th Embodiment of this invention.

(First embodiment)
FIG. 1 is an equivalent circuit plan view of a main part of a liquid crystal display device as a first embodiment of the present invention. In this liquid crystal display device, an active substrate 1 and a counter substrate 2 positioned above the active substrate 1 are bonded together via a substantially rectangular frame-shaped sealing material (not shown), and both substrates 1 inside the sealing material. The liquid crystal (not shown) is sealed between the two. In this case, the lower side portion of the active substrate 1 protrudes from the counter substrate 2. Hereinafter, this protruding portion is referred to as a protruding portion 1a. In FIG. 1, a rectangular area surrounded by a one-dot chain line is a display area 3.

  The display area 3 on the active substrate 1 includes a plurality of pixel electrodes 4 arranged in a matrix, an nMOS type switching thin film transistor 5 having a source electrode S connected to each pixel electrode 4, and a row direction. A scanning line 6 for supplying a scanning signal to the gate electrode G of each switching thin film transistor 5 and a data line 7 for supplying a data signal to the drain electrode D of each switching thin film transistor 5 are provided. Yes.

  Here, in FIG. 1, only 2 × 3 pixel electrodes 4 are shown for the sake of clarity of the drawing, and in actuality, several hundreds × several hundreds or more are required. It is arranged. Around the display area 3 on the active substrate 1, a rectangular frame-like common line 8 and a common connection pad 9 connected thereto are provided. The common connection pad 9 is connected to a common electrode (not shown) provided on the lower surface of the counter substrate 2 via an inter-substrate conductive material (not shown).

  The right end portion of the scanning line 6 is a scanning line driving driver mounting region indicated by a dotted line on the right side on the protruding portion 1a of the active substrate 1 via a scanning lead line 10 provided on the right side and the lower side of the display region 3. 11 is connected to a scanning output terminal 12 provided on the upper side in the frame 11. The lower end of the data line 7 is in the data line driver mounting area 14 indicated by the left dotted line on the protruding portion 1a of the active substrate 1 via the data lead line 13 provided below the display area 3. Is connected to a data output terminal 15 provided on the upper side of the.

  A scanning input terminal 16 is provided below the scanning line driver mounting area 11. The scanning input terminal 16 is connected to a scanning external connection terminal 18 provided below the scanning input terminal 16 via a scanning lead line 17 provided below the scanning input terminal 16. A data input terminal 19 is provided below the data line driving driver mounting area 14. The data input terminal 19 is provided on the lower side of the data input terminal 19 via a data routing line 20 provided on the lower side thereof, but is connected to the data external connection terminal 21. Although the common connection pad 9 is provided on the lower side of the common connection pad 9 via the common routing line 22 provided on the lower side, the common connection pad 9 is connected to the common external connection terminal 23.

  Although not shown for the sake of clarity, external electrodes corresponding to the scanning input terminal 16 and the scanning output terminal 12 are provided on the scanning line driving driver mounting region 11 of the active substrate 1. A scanning line driving chip having a scanning line driving circuit section is mounted, and the external electrode of the scanning line driving chip and the scanning input terminal 16 and the external electrode of the scanning line driving chip and the scanning output terminal 12 are COG (chips). Bonded by the on-glass method. The bonding method may be a soldering method or an anisotropic conductive adhesive.

  In addition, a data line driving chip incorporating a data line driving circuit unit is mounted on the data line driving driver mounting area 14 of the active substrate 1, and an external electrode of the data line driving chip, a data input terminal 19, and data The external electrode of the line driving chip and the data output terminal 15 are bonded by the COG (chip on glass) method. Also in this case, the bonding method may be a soldering method or an anisotropic conductive adhesive method.

  Next, FIG. 2 shows an equivalent circuit plan view of the scanning line electrostatic protection circuit 30 provided in the scanning line driver mounting area 11. A scanning line electrostatic protection line 31 is provided in the scanning line driver mounting area 11. Between the scanning line electrostatic protection line 31 and each scanning output terminal 12 (that is, the scanning lead line 10 connected to the scanning line 6 shown in FIG. 1), the first and second scanning line electrostatic protections are provided. Thin film transistors (electrostatic protection elements for scanning lines) 32 and 33 are provided in parallel.

  In this case, the first scanning line electrostatic protection thin film transistor 32 is a diode-connected nMOS type, the gate electrode G and the drain electrode D are connected to the scanning output terminal 12, and the source electrode S is the scanning line electrostatic protection. Connected to line 31. The second scanning line electrostatic protection thin film transistor 33 is of a floating gate type, the gate electrode G is not connected anywhere, is a floating gate, the drain electrode D is connected to the scanning output terminal 12, The source electrode S is connected to the scanning line electrostatic protection line 31.

  One end of the scanning line electrostatic protection line 31 is connected to the common line 8 shown in FIG. 1 via a connection thin film transistor 34 and a connection lead wire 35. In this case, the gate electrode G and the drain electrode D of the connection thin film transistor 34 are connected to the scanning line electrostatic protection line 31, and the source electrode S is connected to the common line 8 via the connection lead line 35.

  Next, FIG. 3 shows an equivalent circuit plan view of the data line electrostatic protection circuit 40 provided in the data line driving driver mounting region 14. A data line electrostatic protection line 41 is provided in the data line driver mounting area 14. Between the data line static electricity protection line 41 and each data output terminal 15 (that is, the data lead-out line 13 connected to the data line 7 shown in FIG. 1), a floating gate type data line static electricity protection thin film transistor ( Data line electrostatic protection element) 42 is provided.

  In this case, the gate electrode G of the data line static electricity protection thin film transistor 42 is not connected anywhere and is a floating gate, the drain electrode D is connected to the data output terminal 15, and the source electrode S is the data line. It is connected to the static electricity protection line 41 for use.

  One end of the data line electrostatic protection line 41 is connected to the common line shown in FIG. 1 via first and second connection thin film transistors 43 and 44 (connection elements) and connection lead lines 45 provided in parallel. 8 is connected. In this case, the gate electrode G and the drain electrode D of the first connection thin film transistor 43 are connected to the electrostatic protection line 41 for the data line, and the source electrode S is connected to the common line 8 through the connection lead line 45. . The gate electrode G and the drain electrode D of the second connection thin film transistor 44 are connected to the common line 8 via the connection lead line 45, and the source electrode S is connected to the electrostatic protection line 41 for the data line.

  Next, a specific structure of a part of the liquid crystal display device will be described. First, FIG. 4 shows a cross-sectional view of the switching thin film transistor 5 and the pixel electrode 4. At predetermined positions on the upper surface of the active substrate 1 made of glass or the like, a gate electrode G made of chromium or the like, a scanning line 6 connected to the gate electrode G (see FIG. 1), and a scanning line connected to the scanning line 6 A lead wire 10 (see FIG. 1) is provided.

  A gate insulating film 51 made of silicon nitride is provided on the upper surface of the active substrate 1 including the gate electrode G and the scanning line 6. A semiconductor thin film 52 made of intrinsic amorphous silicon is provided at a predetermined position on the upper surface of the gate insulating film 51 on the gate electrode G. A channel protective film 53 made of silicon nitride is provided at substantially the center of the upper surface of the semiconductor thin film 52.

  Ohmic contact layers 54 and 55 made of n-type amorphous silicon are provided on both sides of the upper surface of the channel protective film 53 and on the upper surface of the semiconductor thin film 52 on both sides thereof. A source electrode S made of chromium or the like is provided at a predetermined location on the upper surface of one ohmic contact layer 54 and the upper surface of the gate insulating film 51 in the vicinity thereof. A drain electrode D made of chromium or the like, a data line 7 connected to the drain electrode D, and data connected to the data line 7 are disposed at predetermined positions on the upper surface of the other ohmic contact layer 55 and the upper surface of the gate insulating film 51. A lead wire 13 (see FIG. 1) is provided.

  Here, the switching thin film transistor 5 includes a gate electrode G, a gate insulating film 51, a semiconductor thin film 52, a channel protective film 53, ohmic contact layers 54 and 55, a source electrode S, and a drain electrode D.

  An overcoat film 56 made of silicon nitride is provided on the upper surface of the gate insulating film 51 including the switching thin film transistor 5 and the data line 7. A pixel electrode 4 made of a transparent conductive material such as ITO is provided at a predetermined position on the upper surface of the overcoat film 56. The pixel electrode 4 is connected to the source electrode S through a contact hole 57 provided at a predetermined position of the overcoat film 56.

  Next, FIG. 5 shows a cross section of the first and second scanning line electrostatic protection thin film transistors 32 and 33, the scanning output terminal 12 and the scanning line electrostatic protection line 31 in the scanning line driving driver mounting region 11. The figure is shown. The first and second scanning line electrostatic protection thin film transistors 32 and 33 have substantially the same structure as the switching thin film transistor 5 shown in FIG. 4, and include a gate electrode G, a gate insulating film 51, a semiconductor thin film 52, and a channel protective film 53. , Ohmic contact layers 54 and 55, a source electrode S and a drain electrode D.

  The scanning output terminal 12 includes a lower metal layer 12 a made of chromium or the like provided on the upper surface of the active substrate 1, an upper surface of the lower metal layer 12 a exposed through the contact hole 57 provided in the gate insulating film 51, and It has a two-layer structure with an upper metal layer 12 b made of chromium or the like provided on the upper surface of the gate insulating film 51 around the gate insulating film 51, and is exposed through an opening 58 provided in the overcoat film 56. The scanning line electrostatic protection line 31 is made of a metal layer such as chromium provided on the upper surface of the gate insulating film 51.

  The gate electrode G of the first scanning line electrostatic protection thin film transistor 32 is connected to the lower metal layer 12a of the scanning output terminal 12 via a lead wire 59 made of chromium or the like provided on the upper surface of the active substrate 1. The drain electrode D is connected to the upper metal layer 12b of the scanning output terminal 12, and the source electrode S is connected to the scanning line electrostatic protection line 31. The gate electrode G of the second scanning line electrostatic protection thin film transistor 33 is a floating gate (see FIG. 2), the drain electrode D is connected to the upper metal layer 12b of the scanning output terminal 12, and the source electrode S is The scanning line static electricity protection line 31 is connected.

  Next, FIG. 6 shows a cross-sectional view of the connection thin film transistor 34, the scanning line electrostatic protection line 31, and the common lead-out line 35 in the scanning line driver mounting area 11. The connection thin film transistor 34 has substantially the same structure as the switching thin film transistor 5 shown in FIG. 4, and includes a gate electrode G, a gate insulating film 51, a semiconductor thin film 52, a channel protective film 53, ohmic contact layers 54 and 55, a source electrode S, and It consists of a drain electrode D. The common routing line 35 is made of a metal layer such as chromium provided on the upper surface of the active substrate 1.

  One end of the scanning line electrostatic protection line 31 provided on the upper surface of the gate insulating film 51 is connected to the gate electrode G on the upper surface of the active substrate 1 through a contact hole 60 provided in the gate insulating film 51. The lead wire 61 is made of chromium or the like and is connected to the drain electrode D of the connection thin film transistor 34. The source electrode S of the connecting thin film transistor 34 is connected to the common lead line 35 through a contact hole 62 provided in the gate insulating film 51.

  Next, FIG. 7 shows a cross-sectional view of the data line static electricity protection thin film transistor 42, the data output terminal 15, and the data line static electricity protection line 41 in the data line driving driver mounting region 14. The data line electrostatic protection thin film transistor 42 has substantially the same structure as the switching thin film transistor 5 shown in FIG. 4, and includes a gate electrode G, a gate insulating film 51, a semiconductor thin film 52, a channel protective film 53, ohmic contact layers 54, 55, It consists of a source electrode S and a drain electrode D.

  The data output terminal 15 is made of a metal layer such as chromium provided on the upper surface of the gate insulating film 51. The data line static electricity protection line 41 is made of a metal layer such as chromium provided on the upper surface of the active substrate 1. The gate electrode G of the data line electrostatic protection thin film transistor 42 is a floating gate (see FIG. 3), the drain electrode D is connected to the data output terminal 15, and the source electrode S is provided on the gate insulating film 51. The data line static electricity protection line 41 is connected through the contact hole 63.

  Next, FIG. 8 is a cross-sectional view of the first and second connection thin film transistors 43 and 44, the data line static electricity protection line 41, and the common routing line 45 in the data line driving driver mounting region. The first and second connection thin film transistors 43 and 44 have substantially the same structure as the switching thin film transistor 5 shown in FIG. 4, and include a gate electrode G, a gate insulating film 51, a semiconductor thin film 52, a channel protective film 53, and an ohmic contact layer. 54, 55, a source electrode S and a drain electrode D. The common lead line 45 is made of a metal layer such as chromium provided on the upper surface of the active substrate 1.

  The gate electrode G of the first connection thin film transistor 43 is connected to the data line static electricity protection line 41. The gate electrode G of the second connection thin film transistor 44 is connected to the common lead line 45. The source electrode S of the first connection thin film transistor 43 and the drain electrode D of the second connection thin film transistor 44 are connected to a common lead line 45 through a contact hole 64 provided in the gate insulating film 51. The drain electrode D of the first connection thin film transistor 43 and the source electrode S of the second connection thin film transistor 44 are provided in the same contact hole 65 provided in the gate insulating film 51 (for convenience of illustration in FIG. 8). To the static electricity protection line 41 for data lines.

  By the way, in this liquid crystal display device, as shown in FIG. 1, in the scanning line driving driver mounting region 11 on the protruding portion 1a outside the display region 3 on the active substrate 1, the electrostatic protection line 31 for scanning line, Since the first and second scanning line electrostatic protection thin film transistors 32 and 33 and the connection thin film transistor 34 are provided, a dedicated arrangement region for arranging these is not required, and the frame area is reduced accordingly. be able to.

  Further, in this liquid crystal display device, as shown in FIG. 1, in the data line driving driver mounting region 14 on the protruding portion 1a outside the display region 3 on the active substrate 1, the data line electrostatic protection line 41, Since the data line electrostatic protection thin film transistor 42 and the first and second connection thin film transistors 43 and 44 are provided, a dedicated arrangement region for arranging these is not required, and the frame area is accordingly reduced. be able to.

  Next, the electrostatic protection operation of the liquid crystal display device having the above configuration will be described. In this case, since the failure due to static electricity of the switching thin film transistor 5 is only when positive static electricity enters, the case where the static electricity is positive will be described.

  It is assumed that positive static electricity enters a certain scanning line 6 from the outside for some reason. Then, the scanning line electrostatic protection thin film transistor 32 connected to the scanning line 6 via the scanning lead-out line 10 and the scanning output terminal 12 is turned on, and the scanning line 6 has a current connected thereto. It flows to the scanning line electrostatic protection line 31 through the electrostatic protection thin film transistor 32, and the scanning line electrostatic protection line 31 becomes a high potential.

  When the scanning line electrostatic protection line 31 becomes a high potential, the second scanning line electrostatic protection thin film transistor 33 connected to the remaining scanning lines 6 becomes conductive, and a current is supplied from the scanning line electrostatic protection line 31 to the second state. The other scanning lines 6 flow through the scanning line electrostatic protection thin film transistors 33, and all the scanning lines 6 have the same potential.

  When the scanning line electrostatic protection line 31 is at a high potential, the connection thin film transistor 34 is turned on, and a current flows from the scanning line electrostatic protection line 31 to the common line 8 via the connection thin film transistor 34. It flows to the counter electrode of the counter substrate 2 through the connection pad 9 and the inter-substrate conductive material. Thus, positive static electricity that has entered the scanning line 6 from the outside for some reason is discharged, and defects such as characteristic shift and dielectric breakdown due to static electricity of the switching thin film transistor 5 are prevented.

  In this case, since the diode-connected thin film transistor for connection 34 can conduct in only one direction from the drain electrode D to the source electrode S, the potential of the scanning line electrostatic protection element line 31 is higher than the potential of the common line 8. In this case, the current flows from the scanning line electrostatic protection element line 31 to the common line 8 via the connection thin film transistor 34, but does not flow in the opposite direction, so that the power consumption can be prevented from increasing.

  On the other hand, it is assumed that positive static electricity enters a certain data line 7 from the outside for some reason. Then, the data line static electricity protection thin film transistor 42 connected to the data line 7 becomes conductive, and the current from the data line 7 passes through the data line static electricity protection thin film transistor 42 connected thereto. The static electricity protection line 41 for data lines becomes high potential.

  When the data line static electricity protection line 41 becomes high potential, the data line static electricity protection thin film transistor 42 connected to the remaining data lines 7 becomes conductive, and the current is supplied from the data line static electricity protection line 41 to the data line static electricity protection. The remaining data lines 7 flow through the thin film transistors 42 and all the data lines 7 are at the same potential.

  Further, when the data line static electricity protection line 41 becomes a high potential, the first connection thin film transistor 43 is turned on, and current flows from the data line static electricity protection line 41 to the first connection thin film transistor 43 and the common lead line 45. To the common line 8 and further to the counter electrode of the counter substrate 2 through the common connection pad 9 and the inter-substrate conductive material. Thus, the positive static electricity that has entered the data line 7 for some reason from the outside is discharged, and defects such as characteristic shift and dielectric breakdown due to static electricity of the switching thin film transistor 5 are prevented.

  By the way, when the potential of the electrostatic protection line 41 for data lines is higher than the potential of the common line 8, the first connection thin film transistor 43 is turned on, and current flows from the electrostatic protection line 41 for data lines to the common line 8. Flowing. On the other hand, when the potential of the common line 8 is higher than the potential of the electrostatic protection line 41 for the data line, the second connection thin film transistor 44 is turned on, and current flows from the common line 8 to the electrostatic protection line 41 for the data line. Flowing. When the potential difference between the data line static electricity protection line 41 and the common line 8 is small, it is difficult for current to flow in either direction and power consumption is unlikely to increase.

  By the way, as shown in FIG. 7, the electrostatic protection line 41 for data lines is formed on the upper surface of the active substrate 1. For this reason, as shown in FIG. 7, the source electrode S of the data line static electricity protection thin film transistor 42 is connected to the data line static electricity protection line 41 through the contact hole 63 of the gate insulating film 51. Therefore, the contact hole 63 is required. In the second embodiment to be described next, the contact hole 63 is unnecessary.

(Second Embodiment)
FIG. 9 is a sectional view similar to FIG. 7 of a liquid crystal display device as a second embodiment of the present invention. In this liquid crystal display device, the source electrode S of the data line static electricity protection thin film transistor 42 is connected to the data line static electricity protection line 41 provided on the upper surface of the gate insulating film 51. Therefore, the contact hole 63 as shown in FIG. 7 becomes unnecessary.

  In the liquid crystal display device according to the second embodiment, as shown in FIG. 10 which is a cross-sectional view similar to FIG. 8, the first electrostatic protection line 41 for data lines may be provided on the upper surface of the gate insulating film 51. A contact hole 64 for connecting the source electrode S of the connection thin film transistor 43 and the drain electrode D of the second connection thin film transistor 44 to the common lead line 45 and the electrostatic protection line 41 for the data line are connected to the first connection thin film transistor 43. The contact hole 65 for connecting to the gate electrode G is necessary.

(Third embodiment)
FIG. 11 is an equivalent circuit plan view similar to FIG. 2 of a liquid crystal display device as a third embodiment of the present invention. In this liquid crystal display device, the difference from the case shown in FIG. 2 is that the second scan line electrostatic thin film transistor 33 is omitted, and the source electrode S of the connection thin film transistor 34 is placed in the scan line driving driver mounting region 11. This is a point connected to the Vgl terminal 71 provided in the circuit.

  In this case, a negative voltage (for example, Vgl = −20 to −15 V) applied to the non-selected scanning line 6 is supplied to the Vgl terminal 71. The potential Vgl (−20 to −15 V) of the scanning line 6 in the non-selected state is lower than the potential of the common line 8 (for example, Vcom = −5 to +5 V). Therefore, a current may flow from the scanning line electrostatic protection line 31 to the Vgl terminal 71 via the connection thin film transistor 34.

(Fourth embodiment)
FIG. 12 is an equivalent circuit plan view similar to FIG. 11 of a liquid crystal display device as a fourth embodiment of the present invention. In this liquid crystal display device, the difference from the case shown in FIG. 11 is that the connection thin film transistor 34 is omitted and one end of the scanning line electrostatic protection line 31 is connected to the Vgl terminal 71. In this way, the current may flow directly from the scanning line electrostatic protection line 31 to the Vgl terminal 71.

(Other embodiments)
In the case shown in FIG. 3, the source electrode S of the first connection thin film transistor 43 and the gate electrode G and drain electrode D of the second connection thin film transistor 44 are connected to the Vgl terminal 71 as in the case shown in FIG. You may make it do. Further, in the case shown in FIG. 3, the first and second connection thin film transistors 43 and 44 are omitted, and one end of the data line electrostatic protection line 41 is connected to the Vgl terminal 71 as in the case shown in FIG. You may make it do.

  In the above embodiment, the scanning line driving driver mounting area 11 and the data line driving driver mounting area 14 are separated, but the scanning line driving driver and the data line driving driver are integrated into one chip. When such a one-chip driver is used, a scanning line driving driver mounting area and a data line driving driver mounting area are formed continuously in the scanning line electrostatic protection circuit for the scanning line. The data line static electricity protection circuit may be formed continuously or separately.

  In the above embodiment, the scanning line driving driver mounting area 11 and the data line driving driver mounting area 14 are formed on the protruding portion 1a which is one side of the active substrate 1, but a plurality of sides of the active substrate are used. , And a scanning line driving driver mounting region and a data line driving driver mounting region may be formed in each protruding portion, and an electrostatic protection circuit may be provided for each.

  In each of the above-described embodiments, the entire electrostatic protection circuit does not need to be formed in the driver mounting area, and a part of the electrostatic protection circuit may protrude from the driver mounting area.

  In each of the above embodiments, the liquid crystal display device has been described as the display device. However, the present invention can also be applied to a display device having another display element such as an organic EL or a field emission device.

DESCRIPTION OF SYMBOLS 1 Active substrate 2 Opposite substrate 3 Display area 4 Pixel electrode 5 Switching thin film transistor 6 Scan line 7 Data line 8 Common line 9 Common connection pad 10 Scanning lead line 11 Scan line driving driver mounting area 12 Scan output terminal 13 Data Lead line 14 Data line driving driver mounting area 15 Data output terminal 30 Scanning line electrostatic protection circuit 31 Scanning line electrostatic protection line 32 First scanning line electrostatic protection thin film transistor 33 Second scanning line electrostatic protection Thin film transistor 34 Thin film transistor for connection 35 Common lead line 40 Static protection circuit for data line 41 Static protection line for data line 42 Thin film transistor for electrostatic protection for data line 43, 44 Thin film transistor for connection 45 Common lead The line

Claims (3)

A display region is provided in a region where the first substrate and the second substrate overlap, and the first substrate has a protrusion protruding from one side of the second substrate;
A pixel electrode arranged in a matrix in the display area of the first substrate; a switching thin film transistor connected to the pixel electrode; a scanning line for supplying a scanning signal to the switching thin film transistor; A display device provided with a data line for supplying a data signal to the switching thin film transistor,
A region provided on the protruding portion, on which a driver for driving a scanning line is mounted;
A region provided on the protruding portion, on which a data line driving driver is mounted;
An electrostatic protection circuit for a scanning line provided in an area where the scanning line driving driver is mounted, and having one end connected to the scanning line;
An electrostatic protection circuit for data lines provided in a region where the driver for driving the data lines is mounted, and one end connected to the data line;
A common line that surrounds the periphery of the display region and is provided in a region of the first substrate where the first substrate and the second substrate overlap;
A common external connection terminal provided on an end surface side along one side of the projecting portion and electrically connected to the common line via a lead wire;
With
The common line is connected to an external circuit via the common external connection terminal;
The other end of the scanning line electrostatic protection circuit and the other end of the data line electrostatic protection circuit are electrically connected to the common line via a diode-connected thin film transistor,
The scanning line electrostatic protection circuit and the data line electrostatic protection circuit each have a plurality of floating gate type thin film transistors,
The scanning line electrostatic protection circuit further includes a plurality of electrostatic protection thin film transistors each connected to correspond to one of the floating gate thin film transistors in the scanning line electrostatic protection circuit,
In the region of the scanning output terminal that electrically connects the scanning line and the scanning line driving driver provided in the region where the scanning line driving driver is mounted, the gate electrode of the electrostatic protection thin film transistor is provided. A first metal electric layer formed and a second metal layer forming a drain electrode of the electrostatic protection thin film transistor and a drain electrode of the floating gate type thin film transistor are stacked and electrically connected to each other;
The floating gate type thin film transistors of the scanning line static electricity protection circuit and the floating gate type thin film transistors of the data line static electricity protection circuit are arranged in a line along the same side in the same row. A display device.   2. The display device according to claim 1, wherein the scanning line driving driver and the data line driving driver are one-chip drivers in which each of them is made into one chip. The display device according to claim 1 or 2, wherein the direction perpendicular to the side is a stretching direction of the data line.

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