JP2015084017A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal display device capable of preventing generation of display irregularity that degrades display qualities, caused by application or accumulation of electrostatic charges, without increasing the number of manufacturing processes.SOLUTION: The liquid crystal display device includes a first substrate and a second substrate disposed opposing to each other via a liquid crystal layer, a second polarizing plate disposed on a surface on an image display side of the second substrate, and a first polarizing plate disposed on a surface side of the first substrate, in which a step-like shape is formed by each end of the second polarizing plate, a conductive film, the first substrate, and the first polarizing plate. The liquid crystal display device includes a conductive tape disposed to follow the step-like shape and electrically connecting the first polarizing plate and the conductive film to the ground. One end of the conductive tape is electrically connected to an exposed surface of the conductive film, while the other end is electrically connected to a counter surface side of the first polarizing plate exposed from the end of the first substrate. The first polarizing plate is formed of a conductive material having conductivity. Potentials of the conductive film and of the first polarizing plate are held at the ground potential.

Description

  The present invention relates to a liquid crystal display device, and more particularly, to a structure for suppressing static electricity applied to a pair of transparent substrates disposed to face each other via a liquid crystal layer.

  In the horizontal electric field type liquid crystal display device, since the pixel electrode and the common electrode are formed on the transparent substrate (TFT substrate, first substrate) on the side where the thin film transistor is formed, the transparent side on which the pixel electrode and the common electrode are not formed is formed. It is known that static electricity tends to accumulate on a substrate (color filter (CF) substrate, second substrate). Furthermore, it is known that it is easily affected by external static electricity. As methods for reducing the influence of static electricity, there are methods described in Patent Documents 1 to 3. In the light modulation device described in Patent Document 1 and a projector including the light modulation device, a conductive film is formed on the surface side of the CF substrate and the TFT substrate, and the conductive film and the flexible wiring substrate are electrically connected via a conductive tape. Connected to each other.

  In addition, in the electro-optical device described in Patent Document 2, the manufacturing method thereof, and the electronic device, a conductive film is formed on a CF substrate, and the conductive film and the flexible wiring substrate are electrically connected via a conductive tape. It has become.

  Furthermore, in the liquid crystal display device described in Patent Document 3, a conductive film is formed so as to enclose the CF substrate and the TFT substrate, and the conductive film is in contact with the frame.

JP 20042333501 A JP 2008-203590 A JP 2008-185934 A

  On the other hand, in the manufacture of a liquid crystal display device, each liquid crystal display panel cut out from the mother substrate is individually subjected to a display inspection and then combined with a backlight device or an optical sheet to form a liquid crystal display device. In the display inspection of this liquid crystal display device, in order to inspect for disconnection or short circuit of signal lines formed in the substrate, and for malfunction of the thin film transistor, it is common to perform lighting inspection for each display pixel. However, when static electricity is applied to the liquid crystal display panel, or when static electricity is accumulated, display irregularity occurs particularly during black display, which makes it impossible to perform a predetermined inspection. In particular, when static electricity is applied to the liquid crystal display panel, it takes about 4 hours to eliminate display unevenness caused by static electricity, which is a very big problem that the production efficiency is greatly reduced. A solution is eagerly desired.

  In particular, in the configuration described in Patent Document 1, it is necessary to form a conductive film on the surface side of the TFT substrate, and a conductive tape is disposed on the surface side of the conductive film. There was a problem that the panel became thick.

  In addition, in the configuration described in Patent Document 2, if static electricity is applied to the TFT substrate side, that is, the substrate on which the backlight device is disposed, it is not possible to obtain a sufficient suppression effect against static electricity. There was a problem.

  Furthermore, the configuration described in Patent Document 3 has a problem in that the manufacturing efficiency is reduced because a process is required to apply the conductive layer after cutting and dividing the mother substrate into individual liquid crystal display devices. .

  The present invention has been made in view of these problems, and an object of the present invention is to prevent the occurrence of display unevenness due to the application or accumulation of static electricity that degrades display quality without increasing the number of steps. An object of the present invention is to provide a liquid crystal display device capable of performing

In order to solve the above problems, a liquid crystal display device according to the present invention includes a first substrate on which a thin film transistor or the like is formed, a second substrate disposed opposite to the first substrate via a liquid crystal layer, and the second substrate. A second polarizing plate disposed on the side surface of the image display and a first polarizing plate disposed on the surface side of the first substrate, and electrically connected to a side portion on the opposite surface side of the first substrate. A liquid crystal display device to which a control signal for image display is input through a flexible wiring board,
A conductive film is formed in a region between the second substrate and the second polarizing plate;
At least in the side to which the flexible wiring substrate is connected, the conductive film is exposed from an end of the second polarizing plate, the first substrate is exposed from an end of the second substrate, and the first substrate A polarizing plate is exposed from an end portion of the first substrate, and each end portion of the second polarizing plate, the conductive film, the first substrate, and the first polarizing plate is formed stepwise.
A conductive tape disposed along the stepped shape, electrically connecting the first polarizing plate and the conductive film to a ground;
One end of the conductive tape is electrically connected to the exposed surface of the conductive film, and the other end is exposed from the end of the first substrate. Electrically connected to the
The first polarizing plate is formed of a conductive material having conductivity;
In the liquid crystal display device, a potential between the conductive film and the first polarizing plate is maintained at the ground potential.

  According to the present invention, it is possible to prevent the occurrence of display unevenness due to the application or accumulation of static electricity that degrades display quality without increasing the number of steps.

  Other effects of the present invention will become apparent from the description of the entire specification.

It is a sectional side view for demonstrating the whole structure of the liquid crystal display panel in the liquid crystal display device which is embodiment of this invention. It is a figure for demonstrating the manufacturing process of the liquid crystal display panel in the liquid crystal display device which is embodiment of this invention. It is a figure for demonstrating schematic structure of the liquid crystal display panel of Example 1 of this invention. It is a figure for demonstrating schematic structure of the liquid crystal display panel of Example 2 of this invention. It is a figure for demonstrating schematic structure of the liquid crystal display device of Example 3 of this invention.

  Embodiments to which the present invention is applied will be described below with reference to the drawings. However, in the following description, the same components are denoted by the same reference numerals, and repeated description is omitted. Further, X, Y, and Z shown in the figure indicate an X axis, a Y axis, and a Z axis, respectively.

  FIG. 1 is a side sectional view for explaining an entire configuration of a liquid crystal display panel in a liquid crystal display device according to an embodiment of the present invention. Hereinafter, the entire liquid crystal display device according to an embodiment of the present invention will be described with reference to FIG. The configuration will be described. However, in the following description, the case where the present invention is applied to a liquid crystal display device of a horizontal electric field method (IPS (In-Plane Switching) method) will be described. However, a TN (Twisted Nematic) method, a VA (Vertical Alignment) method, etc. The present invention can also be applied to other types of liquid crystal display devices.

  As shown in FIG. 1, the liquid crystal display panel 1 in the liquid crystal display device of the present embodiment includes a first substrate (TFT (thin film transistor) substrate) 11 on which pixel electrodes, thin film transistors and the like (not shown) are formed, and the first substrate 11. A second substrate (CF (color filter) substrate) 12 that is disposed opposite to the substrate and is formed with a color filter (not shown), and a liquid crystal (liquid crystal layer) 21 that is sandwiched between the first substrate 11 and the second substrate 12. Have In addition, the first substrate 11 and the second substrate 12 are fixed and the liquid crystal 21 is sealed by the sealing material 13 applied in an annular shape around the second substrate 12, and the liquid crystal 21 is also sealed. It has become. However, in the liquid crystal display panel 1 of the present embodiment, a region in which display pixels (hereinafter abbreviated as pixels) are formed in a region in which liquid crystal is sealed becomes a display region. Therefore, even in the region where the liquid crystal is sealed, a region where pixels are not formed and which is not involved in display is not a display region.

  The second substrate 12 has a smaller area than the first substrate 11, the right side of the first substrate 11 in the drawing protrudes from the second substrate 12, and the opposing surface of the first substrate 11 is the second surface. It is exposed from the substrate 12 side. A drive circuit (not shown) constituted by a semiconductor chip is mounted on the side portion of the first substrate 11 on the opposite surface side (upper side in the drawing). This drive circuit is a known drive circuit that drives each pixel arranged in the display area. As the first substrate 11 and the second substrate 12, for example, a known glass substrate is generally used as a base material, but a resinous transparent insulating substrate may be used.

  In the liquid crystal display panel 1 according to the present embodiment, the liquid crystal side surface (opposing surface) of the first substrate 11, which extends in the Y direction in FIG. A scanning signal line (gate line) (not shown) to which a scanning signal is supplied is formed. Further, a video signal line (drain line) (not shown) that extends in the X direction in FIG. 1 and is juxtaposed in the Y direction and is supplied with a video signal (gradation signal) from the drive circuit is formed. A region surrounded by two adjacent drain lines and two adjacent gate lines constitutes a pixel, and a plurality of pixels are arranged in a matrix in the display region along the drain line and the gate line. Yes.

  Each pixel includes, for example, a thin film transistor (not shown) that is turned on / off by a scanning signal from a gate line, a pixel electrode (not shown) to which a video signal from a drain line is supplied via the turned on thin film transistor, and not shown. And a common electrode to which a common signal having a reference potential with respect to the potential of the video signal is supplied via the common line.

  An electric field having a component parallel to the main surface of the first substrate 11 is generated between the pixel electrode and the common electrode, and the liquid crystal molecules are driven by this electric field. -Plane Switching) type liquid crystal display panel 1 (liquid crystal display device) is formed.

  Also, each drain line and each gate line extend beyond the sealing material 13 at the end, and based on an input signal input from an external system through a flexible printed circuit (FPC) 52, a video signal or It is connected to a drive circuit (not shown) that generates a drive signal such as a scanning signal. However, in the liquid crystal display panel 1 of the present embodiment, the drive circuit is formed of a semiconductor chip and mounted on the first substrate 11. However, the drive circuit is mounted on the flexible printed circuit board 52 using a tape carrier method or COF (Chip On Film). ) Method and may be connected to the first substrate 11. Further, the video signal driving circuit for outputting the video signal and the scanning signal driving circuit for outputting the scanning signal may be separately formed and mounted on the first substrate 11. In addition, one or both of the video signal driving circuit and the scanning signal driving circuit are mounted on the flexible printed circuit board 52 by a tape carrier system or a COF (Chip On Film) system and connected to the first substrate 11. It may be a configuration.

Furthermore, in the liquid crystal display panel 1 of the present embodiment, a first polarizing plate (lower polarizing plate) 31 is disposed on the outer surface (back surface) side that is the lower surface side in FIG. . On the other hand, a conductive layer 41 is formed on the outer surface (back surface) which is the upper surface side in FIG. 1 of the second substrate 12, and a second polarizing plate 32 is disposed on the conductive layer 41. At this time, the first polarizing plate 31 of the present embodiment is a conductive polarizing plate, and the sheet resistance is preferably 10 ² Ω / □ to 10 ¹⁰ Ω / □.

  In addition, a liquid crystal display device is configured by combining the liquid crystal display panel 1 and a backlight unit (backlight device) (not shown) serving as a light source. In the following description, the liquid crystal display panel 1 may also be described as a liquid crystal display device.

  In the liquid crystal display panel 1 of the present embodiment, the first polarizing plate 31 also has conductivity, and the first polarizing plate 31 having conductivity is electrically connected to the conductive tape 51. The first polarizing plate 31 is also configured to be held at the potential of the ground GND such as 0 V (zero volt). In particular, in the configuration of the liquid crystal display panel 1 of the present embodiment, the first polarizing plate 31 is formed so as to protrude from the side portion of the first substrate 11 in the X direction on the right side in FIG. Further, in the projected region, the conductive tape 51 and the first tape are formed on the first substrate 11 side that is the opposite surface side of the first polarizing plate 31, that is, the adhesive surface side of the first polarizing plate 31. Since the polarizing plate 31 is electrically connected, an increase in the thickness of the liquid crystal display panel 1 associated with the formation of the conductive tape 51 can be prevented. That is, the liquid crystal display panel 1 of the present invention prevents the influence of static electricity from the back side with the same thickness as a conventional liquid crystal display panel in which a conductive thin film layer is provided only on the second substrate on which the color filter is formed. It becomes possible to do.

  However, the electrical connection between the first polarizing plate 31 and the conductive tape 51 is either a configuration in which an adhesive layer (not shown) has conductivity or a configuration in which the polarizing plate body has conductivity together with the adhesive layer. There may be. Further, the conductive tape 51 is connected to a region where only the polarizing plate main body is conductive and the non-conductive adhesive layer is not applied by the conductive adhesive layer (not shown) of the conductive tape 51. May be.

  Furthermore, in the liquid crystal display panel 1 of the present embodiment, the conductive layer 41 is also electrically connected to the conductive tape 51. At this time, the conductive tape 51 is configured to reach the upper surface of the first polarizing plate 31 through the side surface portion of the second substrate 12, the opposing surface side of the first substrate 11, and the side surface thereof. At this time, in the configuration of the present embodiment, a ground GND signal line (not shown) is formed on the opposing surface of the first substrate 11, and the conductive tape 51 is also electrically connected to this signal line. Furthermore, the ground GND is supplied to the signal line via the flexible wiring board 52. As a result, in the configuration of the present embodiment, the conductive layer 41 protects against static electricity from the viewer side of the liquid crystal display panel 1, and against static electricity from the back side of the display panel. Is configured to be protected by the first polarizing plate 31.

  In the inspection process, for example, the ground GND is directly supplied to the conductive tape 51, or the potential of the ground GND is supplied to a signal line (not shown) to which the ground GND is input via the flexible wiring board 52. With this configuration, even when static electricity is applied during inspection, the applied static electricity flows from the conductive layer 41 or the first polarizing plate 31 to a power supply (not shown) that supplies the ground GND via the conductive tape 51. Therefore, it is possible to prevent display unevenness from occurring in the liquid crystal display panel 1.

  Next, FIG. 2 is a view for explaining a manufacturing process of the liquid crystal display panel in the liquid crystal display device according to the embodiment of the present invention. Hereinafter, based on FIG. A method will be described. However, the formation of the first substrate 11 and the second substrate 12 on the mother substrate and the sealing of the liquid crystal 21 are the same as in the prior art. Therefore, in the following description, it will be described in detail after the mother substrate is divided.

1) Formation of conductive layer On the surface of the mother substrate, on the front side surface of the second substrate 12 where the color filter or the like is formed, that is, on the surface of the surface of the second substrate 12 where the liquid crystal layer 21 is not formed, A conductive layer 41 is formed so as to cover the front side surface of the second substrate 12. At this time, since the conductive layer 41 is formed so as to cover the entire surface of the second substrate 12 on the observer side, the transparent layer having a high transmittance formed of a known transparent conductive film material such as ITO (Indium Tin Oxide) is used. It is a conductive film.

2) Cutting The mother substrate on which the conductive layer 41 is formed on the surface side of the second substrate 12 is cut along the straight lines (cutting lines) extending in the X direction and the Y direction shown in FIG. And divided for each liquid crystal display panel. Further, the corresponding side portion of the second substrate 12 is removed to expose the mounting area of the driving circuit. As a result, as shown in FIG. 2B, the drive circuit mounting region is exposed from the second substrate 12 within the right side of the first substrate 11 in the drawing, that is, the opposing surface of the first substrate 11, and the second substrate 12 is exposed. The two substrates 12 have a smaller area than the first substrate 11.

3) Attaching the second polarizing plate As shown in FIG. 2C, a second polarizing plate 32 made of a well-known polarizing material is attached to the surface side of the second substrate 12, that is, the upper layer of the conductive layer 41. . At this time, the second polarizing plate 32 of the present embodiment is configured to cover at least the display area related to image display, and in order to expose the conductive layer 41 at the side part on the side of the mounting area of the drive circuit, The size of the two polarizing plates 32 in the X direction is smaller than that of the first substrate 11.

4) Attaching the first polarizing plate As shown in FIG. 2D, the front side surface of the first substrate 11, that is, the back side of the liquid crystal display panel 1 (the upper side surface in FIG. 2D) has conductivity. A first polarizing plate 31 is attached. However, FIG. 2 (d) is opposite in cross section to the other FIG.

  As is apparent from FIG. 2D, the first polarizing plate 31 of the present embodiment is configured to cover at least the display area related to image display, and at the side on the side of the mounting area of the drive circuit. The first polarizing plate 31 is exposed from the opposing surface side from the first substrate 11, that is, the arrangement side of the second substrate 12. For this reason, for example, when viewed from the center position of the first substrate 11, at least the size from the center position to the end of the first substrate 11 in the X direction is larger than the size to the end of the first polarizing plate 31. Is formed large. Further, at least the size of the first polarizing plate 31 in the X direction is larger than the size of the second polarizing plate 32 in the X direction.

5) Conductive tape affixing As shown in FIG. 2 (e), a conductive tape 51 is affixed to the side where the drive circuit mounting area is formed. At this time, in the configuration of the present embodiment, the conductive tape 51 electrically connects at least the conductive layer 41 and the signal line of the ground GND (not shown) formed on the first substrate 11 and the first polarizing plate 31. That is, as shown in FIG. 2 (e), one end of the conductive tape 51 is attached to the surface of the edge of the conductive layer 41 exposed from the end of the second polarizing plate 32, and the conductive tape 51 and the conductive layer 41 is electrically connected. In addition, one end of the conductive tape 51 is attached to the surface of the edge portion of the first polarizing plate 31 exposed from the end portion of the first substrate 11, and the conductive tape 51 and the first polarizing plate 31 are electrically connected. Connected to. Further, the intermediate portion of the conductive tape 51 is also attached to the surface (opposing surface) of the edge portion of the first substrate 11 exposed from the end portion of the second substrate 12. By attaching the conductive tape 51 to the first substrate 11, the conductive tape 51 is electrically connected to the connection terminal of the signal line to which the ground signal GND for grounding formed on the front side of the first substrate 11 is supplied. .

  Further, by the steps shown in 1) to 4), at least the drive circuit mounting region (the right end region in FIG. 2E) of the first substrate 11 has its end portion shaped like a staircase. That is, the edge portion of the conductive layer 41 is exposed from the end portion of the second polarizing plate 32, and the opposing surface of the first substrate 11 to which the ground GND is supplied from the end portion of the first substrate 11 (the mounting region of the driving circuit). ) Is exposed, and the edge of the first polarizing plate 31 is exposed from the end of the first substrate 11. Therefore, in Embodiment 1, after the conductive tape 51 having one end affixed to the surface of the edge of the conductive layer 41 is affixed to the conductive layer 41 and the side wall surface portion of the second substrate 12 and the seal material 13 portion. The first substrate 11 is attached to the front side and the side wall portion, and the other end is attached to the surface of the first polarizing plate 31. However, the conductive tape 51 only needs to be electrically connected by a connection method such as a well-known conductive adhesive material at least in the conductive portion, and does not require an electrical connection such as the side wall surface portion of the second substrate 12. The portion may be configured to use a conductive tape 51 to which a conductive adhesive material is not applied.

  In this case, one end of the conductive tape 51 is affixed to the viewer side of the conductive layer 41, but the second polarizing plate 32 is also affixed to the side of the conductive layer 41 on the viewer side. Become. Therefore, by using the conductive tape 51 thinner than the thickness of the second polarizing plate 32, an increase in the thickness of the liquid crystal display panel 1 accompanying the attachment of the conductive tape 51 to the surface side of the conductive layer 41 is prevented. be able to. In the configuration of the present embodiment, the other end of the conductive tape 51 is attached to the opposite surface side of the first polarizing plate 31, so that the conductive tape 51 is attached to the first polarizing plate 31. Accordingly, an increase in the thickness of the liquid crystal display panel 1 can be prevented. Furthermore, in the configuration of this embodiment, since the first polarizing plate 31 having conductivity is used, a conductive film is formed on the back side of the liquid crystal display panel 1, that is, on the front side surface of the first substrate 11. Since no process is required, it is possible to prevent a decrease in production efficiency.

6) Crimping of driving circuit and flexible wiring board As shown in FIG. 2 (f), the driving circuit is mounted on the terminal portion (not shown) of the first substrate 11, and the flexible wiring board 52 is crimped on the connecting terminal portion (not shown). And connect. With the arrangement of the flexible wiring board 52, a ground signal line (not shown) provided on the flexible wiring board 52 and a ground signal line (not shown) formed on the first substrate 11 are electrically connected, and the conductive tape 51 is attached. The conductive layer 41 and the first polarizing plate 31 are also electrically connected to the ground GND.

  Thus, as is clear from the steps described in (1) to (6), in the same process as the conventional liquid crystal display panel in which the conductive thin film layer is provided only on the second substrate on which the color filter is formed. The liquid crystal display panel 1 of the present invention can be formed.

  As described above, in the liquid crystal display device of the present embodiment, the first substrate 11 on which a thin film transistor and the like are formed, the second substrate 12 disposed to face the first substrate 11 with the liquid crystal layer interposed therebetween, and the second It has the 2nd polarizing plate 32 arrange | positioned at the image display side surface of a board | substrate, and the 1st polarizing plate 31 arrange | positioned at the surface side of the 1st board | substrate 11, and it exists in the edge part by the side of the opposing surface of the 1st board | substrate 11. An image display control signal is input via a flexible wiring board 52 that is electrically connected.

At this time, a conductive film 41 is formed in a region between the second substrate 12 and the second polarizing plate 32, and the first polarizing plate 31 is formed of a conductive material having conductivity, and at least flexible wiring. In the side to which the substrate 52 is connected, the conductive film 41 is exposed from the end of the second polarizing plate 32, the first substrate 11 is exposed from the end of the second substrate 12, and the first polarizing plate 31 is The second polarizing plate 32, the conductive film 41, the first substrate 11, and the first polarizing plate 31 are exposed in the end portions of the first substrate 11, and the respective end portions are formed stepwise in this order. . Moreover,
A conductive tape 51 that electrically connects the first polarizing plate 31 and the conductive film 41 is disposed along a stepped shape, and one end of the conductive tape 51 is electrically connected to the exposed surface of the conductive film 41. And the other end is electrically connected to the opposing surface side of the first polarizing plate 31 exposed from the end of the first substrate 11. Further, the middle of the conductive tape 51 is electrically connected to the flexible wiring substrate 52 on the opposite surface side of the first substrate 11, and the ground GND is supplied to the conductive tape 51 via the flexible wiring substrate 52, and at least The potential of the conductive film 41 and the first polarizing plate 31 is held at the potential of the ground GND.

  As a result, even when static electricity is applied from the back surface side of the liquid crystal display panel 1 of the present embodiment, the applied static electricity is disposed on the back surface side of the liquid crystal display panel 1, that is, on the front side surface of the first substrate 11. Then, it flows to the ground GND through the first polarizing plate 31 and the conductive tape 51. As a result, it is possible to prevent static electricity from being applied to the thin film transistor, the pixel electrode, and the liquid crystal layer 21 formed on the opposite surface side of the first substrate 11, and to prevent display unevenness that lowers the display quality. it can. In the inspection process, display unevenness due to the application of static electricity can be prevented, so that production efficiency can be improved.

  In particular, the effect on static electricity in the liquid crystal display device of the present embodiment is effective not only at the time of manufacture but also after the product is manufactured. For example, even when static electricity generated due to rubbing of optical sheets due to vibration or the like is applied from the back surface side of the liquid crystal display panel 1, the applied static electricity can be flowed to the ground GND (released). Furthermore, it is possible to prevent electric charges from being accumulated on the back side of the liquid crystal display panel 1 due to static electricity such as an optical sheet. As a result, display unevenness due to static electricity can be reduced, and display quality can be improved.

  FIG. 3 is a diagram for explaining a schematic configuration of the liquid crystal display panel according to the first embodiment of the present invention. In particular, FIG. 3A is a top view of the display panel according to the first embodiment, and FIG. FIG. 4 is a cross-sectional view taken along line AA ′ shown in FIG.

  As shown in FIG. 3A, in the liquid crystal display panel of the first embodiment, one of the two sides on the short side of the liquid crystal display panel formed in a rectangle is on one side on the short side on the right side in the drawing. A driving circuit 53 in which a video signal driving circuit and a scanning signal driving circuit are formed in one chip is mounted. In the liquid crystal display panel having this configuration, the side portion on which the drive circuit 53 is mounted among the four sides is the widest region in a region (frame region) formed so as to surround the display region 54. Therefore, in the liquid crystal display panel according to the first embodiment, the conductive tape 51 is arranged in the widest frame area together with the drive circuit 53 and the flexible wiring board 52. At this time, the drive circuit 53 and the flexible wiring board 52 are arranged in the center portion in the Y direction, and the conductive tape 51 is attached to an end portion in the Y direction, that is, a region near the longitudinal side.

  In the configuration of the liquid crystal display panel according to the first embodiment, the width of the first polarizing plate 31 in the Y direction, that is, the short direction, is the same as the width of the first substrate 11. The side portions of the first polarizing plate 31 formed in (1) have the same width and extend in the X direction (right side in the drawing) from the end portion of the first substrate 11. With this configuration, when viewed from the observer side, the opposite side surface of the first polarizing plate 31 is exposed from the first substrate 11 with the same width as the Y-direction width of the first substrate 11, and a part of the exposed region. The conductive tape 51 is attached to the surface. At this time, since it is possible to reduce the alignment accuracy in the Y direction when the conductive tape 51 is applied, the work efficiency when the conductive tape 51 is applied can be improved. As a result, the liquid crystal display panel The special effect of improving the production efficiency can be obtained. In particular, it is necessary to reduce the exposure amount (protrusion amount) of the conductive tape 51 from the first substrate 11. For example, the structure is more suitable for a relatively small liquid crystal display device mounted on a portable information terminal or the like.

  By applying the conductive tape 51 described above, as shown in FIG. 3B, the conductive layer 41 and the liquid crystal display panel disposed on the front surface side of the liquid crystal display panel via the conductive tape 51 and the flexible wiring substrate 52 are provided. The first polarizing plate 31 disposed on the back surface side can be electrically connected to the ground GND, that is, grounded.

  In the configuration of the first embodiment, the width of the first polarizing plate 31 in the Y direction, that is, the short direction, is the same as the width of the first substrate 11. The width in the Y direction with the substrate 11 is not limited to the same width. For example, similarly to the Y-direction width of the second polarizing plate 32, the Y-direction width of the first substrate 11 and the second substrate 12 may be smaller. However, the width of the second polarizing plate 32 in the Y direction is at least larger than the width in the Y direction of the irradiation range of the planar light from the backlight device (not shown).

  FIG. 4 is a diagram for explaining a schematic configuration of the liquid crystal display panel according to the second embodiment of the present invention. In particular, FIG. 4A is a top view of the display panel according to the second embodiment, and FIG. These are sectional drawings in the BB 'line shown in Drawing 4 (a). However, the liquid crystal display panel of Example 2 is different from that of Example 1 only in the shape of the first polarizing plate 31, and the other configuration is the same as that of Example 1. Therefore, in the following description, the first polarizing plate 31 will be described in detail.

  As shown in FIG. 4A, the liquid crystal display panel according to the second embodiment also has a configuration in which the conductive tape 51 is arranged together with the drive circuit 53 and the flexible wiring board 52 in the widest frame region on the right side in the drawing. In addition, the drive circuit 53 and the flexible wiring board 52 are disposed in the central portion in the Y direction, and the conductive tape 51 is attached to an end portion in the Y direction, that is, a region near the side portion on the long side.

  In addition, the first polarizing plate 31 of Example 2 is formed so that the width of the first polarizing plate 31 in the Y direction, that is, the short direction, is the same as the width of the first substrate 11. An end portion in the X direction of the first polarizing plate 31 formed in the direction width is configured to coincide with an end portion of the first substrate 11. Further, the first polarizing plate 31 has a configuration in which a portion (extending portion) extending from the end portion in the X direction is formed. With this configuration, when viewed from the observer side, the opposite side surface of the extending portion of the first polarizing plate 31 is exposed from the first substrate 11, and the conductive tape 51 is attached to the exposed extending portion. It becomes the composition to be done.

  By applying the conductive tape 51 described above, as shown in FIG. 4B, the conductive layer 41 and the liquid crystal display panel disposed on the front side of the liquid crystal display panel via the conductive tape 51 and the flexible wiring substrate 52 are provided. The first polarizing plate 31 arranged on the back side is electrically connected to the ground GND. As a result, the same effect as in the first embodiment can be obtained. At this time, in the configuration of the second embodiment, the area of the first polarizing plate 31 exposed (projected) from the first substrate 11 can be reduced. Can significantly reduce the possibility of adhesion. Therefore, in the configuration of the second embodiment, it is possible to form the protrusion amount in the X direction and the size in the Y direction of the portion exposed (protrusion) from the first substrate 11 larger than that of the small liquid crystal display panel. The configuration is more suitable for a medium-sized or large-sized liquid crystal display panel 1.

  In addition, the 1st polarizing plate 31 of Example 2 is formed smaller than the X direction width and the Y direction width of the 1st board | substrate 11 and the 2nd board | substrate 12 similarly to the 2nd polarizing plate 32, and is not shown in figure. A portion that is formed to be larger than the X-direction width and the Y-direction width of the planar light from the backlight device, and polarizes the planar light (polarization portion), and a portion that extends in the X direction from the polarization portion (extension) And the end of the extended portion is exposed from the first substrate 11 and electrically connected to the conductive tape 51.

  FIG. 5 is a diagram for explaining a schematic configuration of a liquid crystal display device according to a third embodiment of the present invention. In particular, FIG. 5A is a top view of a liquid crystal display device using the display panel according to the third embodiment. FIG. 5B is a side sectional view taken along the line CC ′ shown in FIG. However, the liquid crystal display panel of Example 3 is different from that of Example 1 only in the configuration for connecting the conductive tape 51 and the conductive tape 51 to the ground GND, and the other configuration is the same as that of Example 1. Therefore, in the following description, the conductive tape 51 will be described in detail.

  As shown in FIG. 5B, a box in which one surface is opened along the side wall and a backlight device including a light source 63 and a light guide plate (including an optical film) 62 is disposed on the other surface (bottom surface). The liquid crystal display panel is held on the body-like lower frame 61. At this time, a concave portion that communicates from one surface to the other surface is formed on the side wall of the lower frame 61 of the third embodiment, and the other end of the flexible wiring board 52 is an outer surface on the bottom surface side of the lower frame 61 along the concave portion. It is the structure wired to. A control circuit including a well-known power supply circuit (not shown) is disposed on the outer surface, and the other end of the flexible wiring board 52 is electrically connected to the control circuit.

  In the configuration of the third embodiment, the lower frame 61 is formed of a conductive member such as metal, and the ground GND and the lower frame 61 are electrically connected to each other at the attachment portion of the control circuit. 61 is held at the ground potential.

  On the other hand, as shown in FIG. 5B, the conductive tape 51 disposed at the end of the liquid crystal display panel has a configuration in which one end is electrically connected to the conductive layer 41 and the other end. The end portion is electrically connected to the inner wall surface of the lower frame 61, and a ground potential is supplied (grounded) via the lower frame 61. At this time, also in the configuration of Example 3, the conductive tape 51 is formed from the exposed surface of the conductive layer 41 to the conductive layer 41, the second substrate 12, the side surfaces of the sealing material 13, the surface and side surfaces of the first substrate 11, It is electrically connected to the lower frame 61 through the surface and side surfaces of the polarizing plate 31. Therefore, also in the configuration of the third embodiment, the ground potential is supplied to the conductive layer 41 and the first polarizing plate 31, that is, the conductive layer 41 and the first polarizing plate 31 are grounded. As in the case of 1 and 2, even when static electricity is applied, display unevenness can be prevented and display quality can be improved.

  In particular, in the configuration of the third embodiment, since it is possible to connect to the ground GND via the lower frame 61, for example, the ground potential is supplied to the flexible wiring board 52 by being supplied via the lower frame 61. It is also possible to obtain an effect that signal lines can be reduced. However, as in the first embodiment, the conductive tape 51 is connected to the ground GND on the surface of the first substrate 11 via the flexible wiring board 52, and the other end side of the conductive tape 51 is electrically connected to the ground GND. It may be configured to be electrically connected to the ground GND via the lower frame 61.

  Further, in the configuration of Example 3, since the conductive tape 51 is adhered to the side surface portion of the first polarizing plate 31, the exposure amount (projection amount) of the first polarizing plate 31 in the X direction. ) Can be made smaller. Furthermore, since the work for connecting the conductive tape 51 to the ground GND is only adhesion to the lower frame 61 of the conductive tape 51, it is possible to obtain a special effect that the work efficiency can be improved.

  In addition, in the liquid crystal display panel of Examples 1-3 of this invention, although the structure which arrange | positions one conductive tape 51 was demonstrated, it is not limited to this, The structure which arrange | positions two or more conductive tapes 51 It may be. Furthermore, when not connected to the drive circuit 53, the flexible wiring board 52, other signal lines (not shown) or the like formed on the opposing surface of the first substrate 11, a conductive tape 51 having a tape width wider in the Y direction is used. It may be. Thus, by using two or more conductive tapes 51 and a wide conductive tape 51, it is possible to improve the efficiency for releasing static electricity to the ground GND, and further improve the display quality improvement effect. Can do.

  As mentioned above, although the invention made by the present inventor has been specifically described based on the embodiment of the invention and Examples 1-3, the invention is limited to the embodiment of the invention and Examples 1-3. However, various modifications can be made without departing from the scope of the invention.

DESCRIPTION OF SYMBOLS 1 ... Liquid crystal display panel, 11 ... 1st board | substrate, 12 ... 2nd board | substrate, 13 ... Sealing material 21 ... Liquid crystal (liquid crystal layer), 31 ... 1st polarizing plate, 32 ... 2nd Polarizing plate 41 ... conductive layer, 51 ... conductive tape, 52 ... flexible wiring board, 63 ... light source 53 ... drive circuit, 54 ... display area, 61 ... lower frame, 62 ... light guide plate

Claims (7)

A first substrate on which a thin film transistor or the like is formed; a second substrate disposed opposite to the first substrate through a liquid crystal layer; a second polarizing plate disposed on an image display side surface of the second substrate; A control signal for image display is input via a flexible wiring board having a first polarizing plate disposed on the surface side of the first substrate and electrically connected to a side portion on the opposite surface side of the first substrate. A liquid crystal display device,
A conductive film is formed in a region between the second substrate and the second polarizing plate;
At least in the side to which the flexible wiring substrate is connected, the conductive film is exposed from an end of the second polarizing plate, the first substrate is exposed from an end of the second substrate, and the first substrate A polarizing plate is exposed from an end portion of the first substrate, and each end portion of the second polarizing plate, the conductive film, the first substrate, and the first polarizing plate is formed stepwise.
A conductive tape disposed along the stepped shape, electrically connecting the first polarizing plate and the conductive film to a ground;
One end of the conductive tape is electrically connected to the exposed surface of the conductive film, and the other end is exposed from the end of the first substrate. Electrically connected to the
The first polarizing plate is formed of a conductive material having conductivity;
A liquid crystal display device, wherein a potential between the conductive film and the first polarizing plate is held at the ground potential.   The liquid crystal display device according to claim 1, wherein the conductive tape has a thickness smaller than that of the second polarizing plate.   The liquid crystal display device according to claim 1, wherein the conductive tape is disposed near an end portion of the side formed in the stepped shape.   Of the side portions of the first polarizing plate, the side portion on which the conductive tape is disposed has the same width as the region overlapping the first substrate and exceeds the end portion of the first substrate. 4. The liquid crystal display device according to claim 1, wherein the plate extends to the outer peripheral side.   Of the sides of the first polarizing plate, the side on which the conductive tape is disposed is only one portion of the first polarizing plate, with the portion connected to the conductive tape exceeding the end of the first substrate. The liquid crystal display device according to claim 1, wherein the liquid crystal display device has a connection portion that extends to the outer peripheral side. A liquid crystal display panel comprising the first substrate, the second substrate, the first polarizing plate, and the second polarizing plate, and a light source disposed on the back side of the liquid crystal display panel are formed to cover the liquid crystal display panel. And a frame (frame member) in which an opening corresponding to the display area of the liquid crystal display panel is formed,
The frame (frame member) is formed of a conductive member having conductivity,
The other side of the conductive tape is connected to the upper surface of the first polarizing plate and extends to the frame (frame member) through the upper surface of the first polarizing plate. Electrically connected to the member)
The liquid crystal display device according to claim 1, wherein the conductive film, the first polarizing plate, and the frame (frame member) are held at the ground potential.   The conductive film is formed so as to cover the entire surface of the second substrate on the display surface side, and an edge of the conductive film is exposed in an annular shape from the periphery of the second polarizing plate. The liquid crystal display device according to any one of 1 to 6.

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