JP2010256547A - Liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device which suppresses generation of disclination to improve display quality. <P>SOLUTION: The liquid crystal display device includes: a first substrate having a first electrode E1 which is arranged on one principle plane side of an insulating substrate, an insulating film which covers the first electrode, and a second electrode E2 on which a first slit SL1 which is arranged on the insulating film and extends in a second direction D2 different from a first direction sandwiching a straight line part EL which faces the first electrode and extend in a first direction H, and a second slit SL2 which extends in a third direction D3 different from the first and second directions are formed; a second substrate which faces the second electrode of the first substrate; and a liquid crystal layer which is held between the first and second substrates. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a liquid crystal display device, for example, to a liquid crystal display device having a structure in which one substrate constituting the liquid crystal display device includes a pair of electrodes facing each other through an insulating layer.

  In recent years, flat display devices have been actively developed, and among them, liquid crystal display devices have been applied to various fields by taking advantage of features such as light weight, thinness, and low power consumption. Such a liquid crystal display device has a configuration in which a liquid crystal layer is held between a pair of substrates, and displays an image by controlling a modulation rate for light passing through the liquid crystal layer by an electric field between a pixel electrode and a common electrode. Is.

  In recent years, in such a liquid crystal display device, a structure using a lateral electric field (including a fringe electric field) has attracted particular attention from the viewpoint of wide viewing angle. For example, a horizontal electric field mode liquid crystal display device such as an In-Plane Switching (IPS) mode or a Ringe Field Switching (FFS) mode includes a pixel electrode and a common electrode formed on an array substrate. The liquid crystal molecules are switched by forming a transverse electric field substantially parallel to the liquid crystal.

  For example, according to Patent Document 1, a liquid crystal display device having a conductive film formed on the entire surface of one surface of a substrate and a pixel electrode having a plurality of grooves on an insulating film formed on the conductive film. Is disclosed. In particular, in Patent Document 1, the grooves are slit-like and formed in parallel to each other, and the direction of the grooves is oblique to the source line, but the grooves located in the upper half of the pixel and the lower half of the pixel It is disclosed that the direction of the groove is different from each other. By adopting such a multi-domain structure, the viewing angle is improved.

  When such a multi-domain structure is formed, the alignment vector of liquid crystal molecules becomes discontinuous at the center of the pixel, and disclination that does not contribute to display occurs. For example, in white display, an area where disclination has occurred is displayed in black and is recognized as a decrease in transmittance or luminance (that is, black unevenness occurs). In addition, when stress is applied to the screen of the liquid crystal display device from the outside during white display, the disclination moves, grows in other areas, and further stabilizes, thereby increasing black unevenness. There is also a fear.

  Therefore, in the horizontal electric field method as described above, it is required to suppress the occurrence of disclination and improve the display quality.

JP 2008-116502 A

  An object of the present invention is to provide a liquid crystal display device capable of suppressing the occurrence of disclination and improving display quality.

According to the first aspect of the present invention,
a) an insulating substrate; b) a first electrode disposed on one main surface side of the insulating substrate; c) an insulating film covering the first electrode; d) a first electrode disposed on the insulating film. The first slit which faces the electrode and extends in the first direction and extends in a second direction different from the first direction across the straight portion and the first slit different from the first direction and the second direction. A first substrate provided with a second electrode formed with a second slit extending in three directions;
A second substrate facing the second electrode of the first substrate;
A liquid crystal layer held between the first substrate and the second substrate;
A liquid crystal display device is provided.

According to a second aspect of the invention,
a) an insulating substrate; b) a first electrode disposed on one main surface side of the insulating substrate and formed with a linear notch extending in the first direction; and c) an insulating film covering the first electrode. D) A first slit disposed on the insulating film and facing the first electrode and extending in a second direction different from the first direction and extending in a third direction different from the first direction and the second direction. A first substrate comprising: a second electrode, wherein the second slit is formed, and the first slit and the second slit are connected immediately above the notch portion of the first electrode;
A second substrate facing the second electrode of the first substrate;
A liquid crystal layer held between the first substrate and the second substrate;
A liquid crystal display device is provided.

According to a third aspect of the invention,
a) an insulating substrate; b) a first electrode disposed on one main surface side of the insulating substrate; c) an insulating film covering the first electrode; d) a first electrode disposed on the insulating film. The first slit and the second slit that face each other and extend in different directions are connected to form a V-shaped slit, and the V-shaped slit is formed side by side in the first direction. A first substrate comprising: a second electrode in which substantially triangular protrusions protruding toward the corners are formed side by side in the first direction;
A second substrate facing the second electrode of the first substrate;
A liquid crystal layer held between the first substrate and the second substrate;
A liquid crystal display device is provided.

  According to the present invention, it is possible to provide a liquid crystal display device capable of suppressing the occurrence of disclination and improving the display quality.

FIG. 1 is a diagram schematically showing a configuration of a liquid crystal mode liquid crystal display device using a lateral electric field according to an embodiment of the present invention. FIG. 2 is a diagram schematically showing a cross-sectional structure in the active area of the liquid crystal display device shown in FIG. FIG. 3 is a schematic plan view of the structure of one pixel in the array substrate of the first embodiment viewed from the counter substrate side. FIG. 4 is a diagram schematically showing the alignment vector of the liquid crystal molecules in the vicinity of the straight line portion of the second electrode shown in FIG. FIG. 5 is a schematic plan view of the structure of one pixel in the array substrate of the second embodiment viewed from the counter substrate side. FIG. 6 is a schematic plan view of the structure of one pixel in the array substrate of the third embodiment as viewed from the counter substrate side. FIG. 7 is a diagram schematically showing alignment vectors of liquid crystal molecules in the vicinity of the corners of the V-shaped slit formed in the second electrode. FIG. 8 is a diagram schematically showing an alignment vector of liquid crystal molecules in the vicinity of the corner of the V-shaped slit formed in the second electrode in the third embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  Here, as an example of a liquid crystal display device, one substrate is provided with a first electrode and a second electrode, and a lateral electric field formed between these first electrode and second electrode (that is, on the main surface of the substrate). As an example of a liquid crystal mode for switching liquid crystal molecules mainly using a substantially parallel electric field), an FFS mode liquid crystal display device will be described.

  FIG. 1 is a diagram schematically showing a configuration of a liquid crystal display device according to the present embodiment. That is, this liquid crystal display device is an active matrix type liquid crystal display device and includes a liquid crystal display panel LPN. The liquid crystal display panel LPN includes, for example, an array substrate AR as a first substrate, a counter substrate CT as a second substrate disposed to face the array substrate AR, and between the array substrate AR and the counter substrate CT. And a held liquid crystal layer LQ. Such a liquid crystal display panel LPN includes an active area DSP which is a display area for displaying an image. This active area DSP is composed of a plurality of pixels PX arranged in an m × n matrix (where m and n are positive integers).

  In the active area DSP, the array substrate AR has n gate lines Y (Y1 to Yn) extending in the first direction or the row direction H, and the second direction or column so as to intersect the gate lines Y. M × n switching elements arranged in a region including an intersection of the gate line Y and the source line X in each pixel PX, m source lines X (X1 to Xm) extending along the direction V W, first electrode (that is, common electrode) E1 having a common potential, m × n second electrodes (that is, pixel electrodes) E2 that are disposed in each pixel PX and face the first electrode E1 via an insulating film, etc. It has.

  The switching element W is configured by, for example, a thin film transistor (TFT). The gate electrode WG of the switching element W is electrically connected to the gate line Y. Alternatively, the gate electrode WG is formed integrally with the gate line Y. The source electrode WS of the switching element W is electrically connected to the source line X. Alternatively, the source electrode WS is formed integrally with the source line X. The drain electrode WD of the switching element W is electrically connected to the second electrode E2.

  Each gate line Y is drawn outside the active area DSP and connected to a gate driver YD controlled by the controller CNT. Each source line X is drawn outside the active area DSP and connected to a source driver XD controlled by the controller CNT.

  The first electrode E1 extends over substantially the entire active area DSP. The first electrode E1 is electrically connected to a common wiring COM having a common potential supplied from a controller CNT or the like.

  The gate driver YD sequentially supplies scanning signals (drive signals) to the n gate lines Y based on control by the controller CNT. Further, the source driver XD supplies video signals (drive signals) to the m source lines X at the timing when the switching elements W in each row are turned on by the scanning signal based on the control by the controller CNT. The second electrode E2 in each row is set to a pixel potential corresponding to the video signal supplied via the corresponding switching element W with respect to the potential of the first electrode E1.

  The structure of the liquid crystal display panel LPN will be described in detail below.

  FIG. 2 is a schematic cross-sectional view of the liquid crystal display panel LPN shown in FIG.

  That is, the array substrate AR is formed by using an insulating substrate 20 having a light transmission property such as a glass plate. In the array substrate AR, the gate electrode WG of the switching element W is disposed on one main surface of the insulating substrate 20 (that is, the surface facing the liquid crystal layer LQ). The gate electrode WG is formed integrally with the gate line Y disposed on the insulating substrate 20. Similarly, the common wiring COM is also disposed on the insulating substrate 20. Such a gate line Y, gate electrode WG, and common wiring COM can be formed of the same material in the same process, and are formed of a conductive material such as molybdenum, aluminum, tungsten, or titanium.

  The gate line Y, the gate electrode WG, and the common wiring COM are covered with the first insulating film 22. The first insulating film 22 is also disposed on the insulating substrate 20. The first insulating film 22 is formed of an inorganic material such as silicon nitride (SiN).

  The semiconductor layer SC is disposed on the first insulating film 22 and is located immediately above the gate electrode WG. That is, the semiconductor layer SC is disposed above the gate line Y and the gate electrode WG. The semiconductor layer SC can be formed of, for example, polysilicon or amorphous silicon. Here, the semiconductor layer SC is formed of amorphous silicon and constitutes a bottom-gate transistor.

  The source electrode WS of the switching element W is disposed on the first insulating film 22. The source electrode WS is formed integrally with the source line X disposed on the first insulating film 22. Further, the drain electrode WD of the switching element W is disposed on the first insulating film 22. That is, the source line X, the source electrode WS, and the drain electrode WD are disposed in the same layer as the semiconductor layer SC, and are disposed in an upper layer than the gate line Y and the gate electrode WG.

  The source electrode WS and the drain electrode WD are in contact with the semiconductor layer SC, respectively. The source line X, the source electrode WS, and the drain electrode WD can be formed of the same material and in the same process, and are formed of a conductive material such as molybdenum, aluminum, tungsten, or titanium.

  These source line X, source electrode WS, and drain electrode WD are covered with a second insulating film 24. The second insulating film 24 is also disposed on the first insulating film 22. The second insulating film 24 is formed of an inorganic material such as silicon nitride (SiN) or an organic material such as a resin layer.

  The first electrode E1 is disposed on the second insulating film 24. The first electrode E1 is electrically connected to the common wiring line COM through a contact hole CH1 that penetrates the first insulating film 22 and the second insulating film 24. That is, the potential of the first electrode E1 is a common potential. The first electrode E1 is formed with an opening AP for ensuring conduction between the switching element W and the second electrode E2. The first electrode E1 is formed of a light-transmitting conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO).

  The first electrode E1 is covered with a third insulating film 26. The third insulating film 26 is also disposed on the second insulating film 24 exposed by the opening AP. The third insulating film 26 is formed of an inorganic material such as silicon nitride (SiN) or an organic material such as a resin layer.

  The second electrode E <b> 2 is disposed on the third insulating film 26. That is, the second electrode E2 is arranged in an upper layer than the first electrode E1 and the like. The second electrode E2 faces the first electrode E1 across the third insulating film 26 in each pixel PX. That is, the third insulating film 26 functions as an interlayer insulating film interposed between the first electrode E1 and the second electrode E2.

  The second electrode E2 is electrically connected to the drain electrode WD through a contact hole CH2 penetrating the second insulating film 24 and the third insulating film 26 at a position corresponding to the opening AP formed in the first electrode E1. It is connected to the. Similar to the first electrode E1, the second electrode E2 is formed of a light-transmitting conductive material such as ITO or IZO. The second electrode E2 has a slit SL that faces the first electrode E1.

  The surface in contact with the liquid crystal layer LQ of the array substrate AR having such a configuration is covered with the alignment film AL1.

  On the other hand, the counter substrate CT is formed using an insulating substrate 30 having optical transparency such as a glass plate. The counter substrate CT includes a black matrix BM that partitions each pixel PX on one main surface of the insulating substrate 30 (that is, a surface facing the liquid crystal layer LQ).

  The black matrix BM is formed in a lattice shape on the insulating substrate 30 so as to face the gate lines Y and source lines X provided on the array substrate AR, and further to the wiring portions such as the switching elements W. The black matrix BM is formed of a light shielding metal material such as a resin material colored black or chromium (Cr), for example.

  In particular, in a color display type liquid crystal display device, the counter substrate CT includes a color filter layer CF in a region surrounded by the black matrix BM. The color filter layer CF is disposed on the insulating substrate 30 and a part thereof is disposed on the black matrix BM. Such a color filter layer CF is formed of a plurality of different colors, for example, colored resins colored in three primary colors such as red, blue, and green. The red colored resin, the blue colored resin, and the green colored resin are disposed corresponding to the red pixel, the blue pixel, and the green pixel, respectively.

  In the liquid crystal mode using the lateral electric field as described above, it is desirable that the surface of the counter substrate CT that is in contact with the liquid crystal layer LQ is flat. It is desirable to provide an overcoat layer or the like that is disposed with a relatively thick film thickness so as to flatten the unevenness of the surface.

  The surface in contact with the liquid crystal layer LQ of the counter substrate CT is covered with the alignment film AL2. The alignment films AL1 and AL2 are made of, for example, polyimide (PI).

  The array substrate AR and the counter substrate CT as described above are arranged so that the alignment films AL1 and AL2 face each other. At this time, a spacer (not shown) (for example, a columnar spacer integrally formed on one substrate with a resin material) is disposed between the array substrate AR and the counter substrate CT, thereby forming a predetermined gap. Is done. The array substrate AR and the counter substrate CT are bonded together by a sealing material (not shown) in a state where a predetermined gap is formed.

  The liquid crystal layer LQ is composed of a liquid crystal composition including liquid crystal molecules LM sealed in a gap formed between the alignment film AL1 of the array substrate AR and the alignment film AL2 of the counter substrate CT.

  The alignment film AL1 and the alignment film AL2 are rubbed so as to regulate the alignment of the liquid crystal molecules LM contained in the liquid crystal layer LQ. That is, each of the liquid crystal molecules LM is aligned by the regulation force by the alignment film AL1 and the alignment film AL2. The rubbing directions of the alignment film AL1 and the alignment film AL2 are non-parallel and non-perpendicular to the major axis of the slit SL formed in the second electrode E2, for example.

  The liquid crystal display device including the transmissive liquid crystal display panel LPN further includes an illumination unit, that is, a backlight unit BL disposed on the array substrate AR side of the liquid crystal display panel LPN. The backlight unit BL illuminates the liquid crystal display panel LPN from the array substrate AR side. As such a backlight, various forms are applicable, and any of those using a light emitting diode (LED) or a cold cathode tube (CCFL) as a light source can be applied. A description of the detailed structure is omitted.

  This liquid crystal display device includes an optical element OD1 provided on one outer surface of the liquid crystal display panel LPN (that is, the surface opposite to the surface in contact with the liquid crystal layer LQ of the array substrate AR), and the liquid crystal display panel LPN. The optical element OD2 is provided on the other outer surface (that is, the surface opposite to the surface in contact with the liquid crystal layer LQ of the counter substrate CT). That is, the optical element OD1 is attached to the insulating substrate 20, and the optical element OD2 is attached to the insulating substrate 30.

  Each of these optical elements OD1 and OD2 includes a polarizing plate, for example, no potential difference is formed between the first electrode E1 and the second electrode E2 (that is, the first electrode E1 and the second electrode E2 A normally black mode is realized in which the transmittance of the liquid crystal display panel LPN is lowest (that is, a black screen is displayed) when there is no electric field between which no electric field is formed.

  That is, in such a liquid crystal display device, when no electric field is applied, the liquid crystal molecules LM are aligned such that the major axis D is oriented in a direction parallel to the rubbing direction of the alignment films AL1 and AL2. In such a state, the backlight light from the backlight unit BL passes through the optical element OD1, passes through the liquid crystal display panel LPN, and is absorbed by the optical element OD2 (black screen display).

  When a potential difference is formed between the first electrode E1 and the second electrode E2 (that is, when a voltage having a potential different from the common potential is applied to the second electrode E2), the first electrode E1 A lateral electric field (fringe electric field) is formed between the first electrode E2 and the second electrode E2. This transverse electric field is formed mainly in the direction perpendicular to the major axis of the slit SL via the slit SL.

  At this time, the alignment state of the liquid crystal molecules LM changes, for example, so that the major axis D of the liquid crystal molecules LM is directed from the rubbing direction to the direction parallel to the lateral electric field. As described above, when the orientation of the major axis D of the liquid crystal molecules LM changes from the rubbing direction, the modulation factor for the light transmitted through the liquid crystal layer LQ changes. Therefore, part of the backlight light emitted from the backlight unit BL and transmitted through the liquid crystal display panel LPN is transmitted through the second optical element OD2 (white screen display). That is, the transmittance of the liquid crystal display panel LPN changes depending on the magnitude of the electric field. In the liquid crystal mode using the horizontal electric field, the backlight is selectively transmitted in this way, and an image is displayed.

  Next, a first embodiment of an array substrate AR applicable to the above-described liquid crystal display panel LPN will be described.

  FIG. 3 is a schematic plan view of the structure of one pixel PX in the array substrate AR of the first embodiment as viewed from the counter substrate CT side.

  Each gate line Y extends along the first direction H. The gate line Y is formed integrally with the gate electrode WG of the switching element W. The semiconductor layer SC of the switching element W is disposed immediately above the gate electrode WG. The common wiring COM is formed substantially parallel to the gate line Y and extends along the first direction H.

  Each source line X is bent in a V shape at a position adjacent to the second electrode E2. That is, the source line X has a bent portion XB extending along the second direction D2 and the third direction D3 different from the first direction H. Each source line X extends along a fourth direction V orthogonal to the first direction H across the bent portion XB, and intersects each gate line Y.

  The second direction D2 and the third direction D3 are both directions different from the first direction H and the fourth direction V, and are slightly inclined with respect to the fourth direction V. That is, the second direction D2 and the third direction D3 are angles smaller than 45 degrees and larger than 0 degrees with the fourth direction V. In other words, the angles formed with the first direction H are 45 degrees. The angle is larger than 90 degrees and smaller than 90 degrees. The second direction D2 is also a direction that is line-symmetric with respect to the third direction D3 and the first direction H. That is, the second direction D2 and the third direction D3 are substantially equal to each other in the angle formed with the first direction H and the angle formed with the fourth direction V. However, the directions of the second direction D2 and the third direction D3 are different from each other.

  The source line X is formed integrally with the source electrode WS of the switching element W. The source electrode WS is branched from the source line X and is in contact with the semiconductor layer SC. The drain electrode WD of the switching element W is separated from the source electrode WS and is in contact with the semiconductor layer SC.

  The first electrode E1 extends over substantially the entire area including each pixel PX. The first electrode E1 is electrically connected to the common wiring COM through a contact hole (not shown).

  The second electrode E2 is formed in an island shape corresponding to the pixel shape in each pixel PX. That is, the second electrode E2 disposed between the two source lines X each having the bent portion XB has a bent shape. The second electrode E2 is arranged in an upper layer than the first electrode E1, and faces the first electrode E1. The second electrode E2 is electrically connected to the drain electrode WD of the switching element W through the contact hole CH2.

  The second electrode E2 has a slit SL that faces the first electrode E1. The slit SL of the second electrode E2 has a first slit SL1 extending in the second direction D2 and a second slit SL2 extending in the third direction D3.

  That is, the first slit SL1 is formed in substantially the upper half of the pixel PX in FIG. 3, and the long axis L1 is formed substantially parallel to the second direction D2. A plurality of first slits SL1 are formed, and each of the first slits SL1 is formed in parallel in the first direction H. Further, both ends of each first slit SL1 are inclined opposite to each other with respect to the long axis L1, and each first slit SL1 is formed in a substantially S shape. The angle formed by the long axis L1 and the straight line LN parallel to the first direction H drawn at the approximate center of the pixel PX is an acute angle greater than 45 degrees.

  The second slit SL2 is formed in substantially the lower half of the pixel PX in FIG. 3, and its long axis L2 is formed substantially parallel to the third direction D3. A plurality of second slits SL <b> 2 are formed, and each of the second slits SL <b> 2 is formed in parallel in the first direction H. The number of second slits SL2 is the same as the number of first slits SL1. Further, both ends of each second slit SL2 are inclined opposite to each other with respect to the long axis L2, and each second slit SL2 is formed in a substantially S shape. The angle formed by the major axis L2 and the straight line LN is an acute angle greater than 45 degrees. Further, the first slit SL1 and the second slit SL2 are formed substantially symmetrical with respect to the straight line LN. That is, the angle formed between the long axis L1 and the straight line LN is substantially the same as the angle formed between the long axis L2 and the straight line LN.

  The second electrode E2 has a straight line portion EL extending in the first direction H. The straight line portion EL is formed at the approximate center of the pixel PX. The first slit SL1 and the second slit SL2 are each formed with the straight line portion EL interposed therebetween. That is, each slit SL is divided into the first slit SL1 and the second slit SL2 by the straight line portion EL.

  When a potential difference is formed between the second electrode E2 and the first electrode E1 having such a shape, an electric field is formed between the first electrode E1 and the second electrode E2 via the slit SL. The The electric field formed at this time is substantially orthogonal to the edge of the second electrode E2 that defines the first slit SL1 and the second slit SL2. The electric field EF1 formed through the first slit SL1 is substantially uniform. Further, the electric field EF2 formed through the second slit SL2 is also substantially uniform, but is not parallel to the electric field EF1.

  FIG. 4 is a diagram schematically showing an alignment vector of liquid crystal molecules in the vicinity of the straight line portion EL of the second electrode E2 shown in FIG.

  The alignment vector V1 indicates the direction of liquid crystal molecules aligned by the electric field EF1 formed through the first slit SL1 shown in FIG. An alignment vector V2 indicates the direction of liquid crystal molecules aligned by the electric field EF2 formed through the second slit SL2 shown in FIG. In the vicinity of the straight line portion EL, the orientation vector V1 and the orientation vector V2 are in different directions, but the region provided with the straight line portion EL serves as a buffer zone and eliminates the discontinuity of the orientation.

  Thereby, the occurrence of disclination is suppressed. Therefore, the occurrence and growth of black unevenness is suppressed, and the decrease in luminance or transmittance is suppressed. For this reason, display quality can be improved.

  Next, a second embodiment of the array substrate AR applicable to the above-described liquid crystal display panel LPN will be described.

  FIG. 5 is a schematic plan view of the structure of one pixel PX in the array substrate AR of the second embodiment as viewed from the counter substrate CT side. In addition, about the same structure as 1st Embodiment, the same referential mark is attached | subjected and detailed description is abbreviate | omitted.

  In the second embodiment, compared to the first embodiment described above, the first electrode E1 is formed with a linear notch NT extending in the first direction H and formed in the second electrode E2. The difference is that the first slit SL1 and the second slit SL2 are connected immediately above the cutout portion NT.

  That is, the first electrode E1 extends over substantially the entire area including each pixel PX, as in the first embodiment. In the first electrode E1, a notch NT is formed in the approximate center of each pixel PX. The notch NT is provided at one location of each pixel PX, for example, and is formed in a straight line extending in the first direction H. Note that the notch NT may further extend in the first direction H and be provided across a plurality of pixels PX adjacent in the first direction H.

  A slit SL facing the first electrode E1 is formed in the second electrode E2. The slit SL of the second electrode E2 has a first slit SL1 extending in the second direction D2 and a second slit SL2 extending in the third direction D3.

  The first slit SL1 formed in the substantially upper half of the pixel PX has a long axis L1 formed substantially parallel to the second direction D2. A plurality of first slits SL1 are formed, and each of the first slits SL1 is formed in parallel in the first direction H.

  The second slit SL2 formed in the substantially lower half of the pixel PX has a major axis L2 formed substantially parallel to the third direction D3. The same number of second slits SL2 as the first slits SL1 are formed, and each of the second slits SL2 is formed in parallel in the first direction H.

  The first slit SL1 and the second slit SL2 are connected at the approximate center of the pixel PX, which is directly above the notch NT formed in the first electrode E1. That is, the combination of one first slit SL1 and one second slit SL2 forms a V-shaped slit SL. In each pixel PX, the second electrode E2 has a plurality of V-shaped slits SL arranged in parallel in the first direction H. The corner of each V-shaped slit SL is located immediately above the notch NT.

  When a potential difference is formed between the second electrode E2 and the first electrode E1 having such a shape, an electric field is generated between the first electrode E1 and the second electrode E2 via the V-shaped slit SL. Is formed. At this time, in the vicinity of the notch portion NT, as in the vicinity of the straight line portion EL shown in FIG.

  Thereby, the occurrence of disclination is suppressed as in the first embodiment. Therefore, the same effect as the first embodiment can be obtained.

  Next, a third embodiment of the array substrate AR applicable to the above-described liquid crystal display panel LPN will be described.

  FIG. 6 is a schematic plan view of the structure of one pixel PX in the array substrate AR of the third embodiment as viewed from the counter substrate CT side. In addition, about the same structure as 1st Embodiment, the same referential mark is attached | subjected and detailed description is abbreviate | omitted.

  In the third embodiment, compared to the first embodiment described above, the first slit SL1 and the second slit SL2 formed in the second electrode E2 are connected to form a V-shaped slit SL. The V-shaped slit SL is formed side by side in the first direction H, and the second electrode E2 has a substantially triangular projection EC protruding toward the corner of the V-shaped slit SL. Is different.

  That is, the first electrode E1 extends over substantially the entire area including each pixel PX, as in the first embodiment.

  A V-shaped slit SL facing the first electrode E1 is formed in the second electrode E2. The V-shaped slit SL is formed by a first slit SL1 extending in the second direction D2 and a second slit SL2 extending in the third direction D3.

  The first slit SL1 formed in the substantially upper half of the pixel PX has a long axis L1 formed substantially parallel to the second direction D2. A plurality of first slits SL1 are formed, and each of the first slits SL1 is formed in parallel in the first direction H.

  The second slit SL2 formed in the substantially lower half of the pixel PX has a major axis L2 formed substantially parallel to the third direction D3. The same number of second slits SL2 as the first slits SL1 are formed, and each of the second slits SL2 is formed in parallel in the first direction H.

  As in the second embodiment, each of the first slit SL1 and the second slit SL2 is connected at the approximate center thereof. In each pixel PX, the second electrode E2 has a plurality of V-shaped slits SL arranged in parallel in the first direction H. A corner SLC of each V-shaped slit SL faces the same direction and is positioned on a straight line LN parallel to the first direction H drawn at the approximate center of the pixel PX.

  The second electrode E2 is provided with a plurality of substantially triangular projections EC that protrude toward the corners SLC of the V-shaped slits SL. These protrusions EC are formed side by side in the first direction H. In addition, the apex angle of the protrusion EC faces the same direction and is positioned on the straight line LN. That is, the corner SLC of the V-shaped slit SL and the protrusion EC are located on the same straight line.

  When a potential difference is formed between the second electrode E2 and the first electrode E1 having such a shape, an electric field is formed between the first electrode E1 and the second electrode E2 via the V-shaped slit SL. Is formed. At this time, as shown in FIG. 7, when no projection is provided, the alignment vector V1 and the alignment vector V2 are mixed in the vicinity of the corner SLC of the V-shaped slit SL, and the alignment of the liquid crystal molecules LM is performed. It becomes discontinuous. For this reason, disclination occurs.

  On the other hand, as shown in FIG. 8, when the protrusion EC as in the third embodiment is provided, the alignment continuity of the liquid crystal molecules LM is near the corner SLC of the V-shaped slit SL. Therefore, the occurrence of disclination is suppressed.

  Therefore, also in such 3rd Embodiment, the effect similar to 1st Embodiment is acquired.

  As described above, according to the present embodiment, it is possible to provide a liquid crystal display device capable of suppressing the occurrence of disclination and improving the display quality.

  In addition, this invention is not limited to the said embodiment itself, In the stage of implementation, it can change and implement a component within the range which does not deviate from the summary. Further, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine suitably the component covering different embodiment.

  In the above-described embodiment, the FFS mode has been described as an example. However, the present embodiment can also be applied to an IPS mode using a lateral electric field.

LPN ... Liquid crystal display panel DSP ... Active area PX ... Pixel AR ... Array substrate CT ... Counter substrate LQ ... Liquid crystal layer Y ... Gate line X ... Source line W ... Switching element E1 ... First electrode NT ... Notch E2 ... Second electrode EL ... Linear part EC ... Protrusion SL ... Slit SL1 ... First slit SL2 ... Second slit

Claims (7)

An insulating substrate, a first electrode disposed on one main surface side of the insulating substrate, an insulating film covering the first electrode, an insulating film disposed on the insulating film, facing the first electrode, and in a first direction A first slit extending in a second direction different from the first direction, and a second slit extending in a third direction different from the first direction and the second direction. A first substrate comprising: a second electrode formed with:
A second substrate facing the second electrode of the first substrate;
A liquid crystal layer held between the first substrate and the second substrate;
A liquid crystal display device comprising: An insulating substrate; a first electrode disposed on one main surface side of the insulating substrate and formed with a linear notch extending in a first direction; an insulating film covering the first electrode; and an upper surface of the insulating film A first slit extending in a second direction different from the first direction and a second slit extending in a third direction different from the first direction and the second direction are formed. A first substrate comprising: a second electrode in which the first slit and the second slit are connected immediately above the notch of the first electrode;
A second substrate facing the second electrode of the first substrate;
A liquid crystal layer held between the first substrate and the second substrate;
A liquid crystal display device comprising: An insulating substrate, a first electrode disposed on one main surface side of the insulating substrate, an insulating film covering the first electrode, and disposed on the insulating film so as to face the first electrode and in directions different from each other The first slit and the second slit extending to each other are connected to form a V-shaped slit, the V-shaped slit is formed side by side in the first direction, and protrudes toward the corner of each V-shaped slit. A first substrate comprising: a second electrode having triangular protrusions arranged in the first direction; and
A second substrate facing the second electrode of the first substrate;
A liquid crystal layer held between the first substrate and the second substrate;
A liquid crystal display device comprising:   4. The liquid crystal display device according to claim 1, wherein each of the first slit and the second slit is formed substantially in parallel along the first direction. 5. The first substrate further includes a switching element,
The liquid crystal display device according to claim 1, wherein the second electrode is electrically connected to the switching element. The first substrate further includes a bent source line connected to the switching element,
The liquid crystal display device according to claim 1, wherein the source line is formed substantially parallel to the first slit and the second slit.   The liquid crystal display device according to claim 1, wherein the first electrode is electrically connected to a common wiring having a common potential.

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