JP5397982B2 - Liquid crystal display device and electronic device - Google Patents

Description

  The present invention relates to a liquid crystal display device and an electronic apparatus.

  As a liquid crystal display device, a vertical electric field type such as a TN (Twisted Nematic) mode, a VA (Vertical Alignment) mode, and an MVA (Multi-domain Vertical Alignment) mode is often used, but an electrode is provided only on one substrate. Also known is a horizontal electric field type liquid crystal display device equipped with an IPS mode liquid crystal display device of the horizontal electric field type liquid crystal display device with reference to FIG. 15 and FIG. 16 (for example, Patent Document 1).

  FIG. 15 is a schematic plan view of one pixel that is seen through the color filter substrate CF of the conventional IPS mode liquid crystal display device 150. 16 is a cross-sectional view taken along line XVI-XVI ′ of FIG.

  The IPS mode liquid crystal display device 150 includes an array substrate AR and a color filter substrate CF. In the array substrate AR, a plurality of scanning lines 154 and common wirings 156 are provided in parallel to the surface of the first transparent substrate 152, and a plurality of signal lines 158 are provided in a direction intersecting the scanning lines 154 and common wirings 156. ing. Further, for example, a comb-like counter electrode (also referred to as a “common electrode”) 160 is provided in the central portion of each pixel in a band shape from the common wiring 156, and the comb-like counter electrode is also sandwiched around the counter electrode 160. A pixel electrode 162 is provided. The surfaces of the counter electrode 160 and the pixel electrode 162 are covered with, for example, a protective insulating film 164 made of silicon nitride and an alignment film 166 made of polyimide or the like.

  Also, a TFT (Thin Film Transistor) as a switching element is formed in the vicinity of the intersection of the scanning line 154 and the signal line 158. In this TFT, the semiconductor layer 168 is disposed between the scanning line 154 and the signal line 158, the signal line portion on the semiconductor layer 168 constitutes the source electrode S of the TFT, and the scanning line 154 portion below the semiconductor layer 168. Constitutes a gate electrode G, and a conductive layer overlapping a part of the semiconductor layer 168 constitutes a drain electrode D. The drain electrode D is connected to the pixel electrode 162.

  The color filter substrate CF has a configuration in which a color filter layer 172, an overcoat layer 174, and an alignment film 176 are provided on the surface of the second transparent substrate 170. Then, the array substrate AR and the color filter substrate CF are opposed so that the pixel electrode 162 and the counter electrode 160 of the array substrate AR and the color filter layer 172 side of the color filter substrate CF are opposed to each other. Next, the liquid crystal LC is sealed between the array substrate AR and the color filter substrate CF, and the polarizing plates 178 and 180 are disposed on the outer sides of the two substrates so that the polarization directions intersect with each other. A mode liquid crystal display device 150 is formed.

  In the IPS mode liquid crystal display device 150, as shown in FIG. 16, when an electric field is generated between the pixel electrode 162 and the counter electrode 160, the horizontally aligned liquid crystal rotates in the horizontal direction. Thus, the amount of incident light transmitted from the backlight can be controlled.

  Next, the operation principle of the FFS mode liquid crystal display device will be described with reference to FIGS. 17 and 18 (see, for example, Patent Document 2).

  FIG. 17 is a schematic plan view of one pixel that is seen through the color filter substrate CF of the conventional FFS mode liquid crystal display device 190. 18 is a cross-sectional view taken along line XVIII-XVIII ′ of FIG.

  The FFS mode liquid crystal display device 190 includes an array substrate AR and a color filter substrate CF. In the array substrate AR, a plurality of scanning lines 194 and common wirings 196 are provided in parallel on the surface of the first transparent substrate 192, and a plurality of signal lines 198 are provided in a direction intersecting the scanning lines 194 and common wirings 196. ing. The counter is formed of a transparent material made of ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), or the like connected to the common wiring 196 so as to cover each of the regions partitioned by the scanning lines 194 and the signal lines 198. An electrode 200 is provided. A pixel electrode 206 made of a transparent material such as ITO and having a plurality of slits 204 formed in a stripe shape is provided on the surface of the counter electrode 200 via an insulating film 202. The surfaces of the pixel electrode 206 and the plurality of slits 204 are covered with an alignment film 208.

  A TFT as a switching element is formed in the vicinity of the intersection position between the scanning line 194 and the signal line 198. In this TFT, the semiconductor layer 210 is disposed on the surface of the scanning line 194, and a part of the signal line 198 is extended so as to cover a part of the surface of the semiconductor layer 210 to form the source electrode S. The lower scanning line portion constitutes the gate electrode G, and the conductive layer overlapping with a part of the semiconductor layer 210 constitutes the drain electrode D. The drain electrode D is connected to the pixel electrode 206.

  The color filter substrate CF has a configuration in which a color filter layer 214, an overcoat layer 216, and an alignment film 218 are provided on the surface of the second transparent substrate 212. Then, the array substrate AR and the color filter substrate CF are opposed so that the pixel electrode 206 and the counter electrode 200 of the array substrate AR and the color filter layer 214 of the color filter substrate CF are opposed to each other. Next, the liquid crystal LC is sealed between the array substrate AR and the color filter substrate CF, and the polarizing plates 220 and 222 are disposed on the outer sides of the two substrates so that the polarization directions thereof are orthogonal to each other. A mode liquid crystal display device 190 is formed.

  In the FFS mode liquid crystal display device 190, when an electric field is generated between the pixel electrode 206 and the counter electrode 200, the electric field is directed to the counter electrode 200 on both sides of the pixel electrode 206 as shown in FIG. Therefore, not only the liquid crystal present in the slit 204 but also the liquid crystal present on the pixel electrode 206 can move.

JP 2003-140188 A JP 2001-56476 A

  However, in the liquid crystal display device 150 in the IPS mode, the liquid crystal molecules on the electrodes are not easily twisted due to the strength of the electric field strength, which causes a decrease in display brightness. Further, in the FFS mode liquid crystal display device 190, the liquid crystal molecules between the electrodes and on the electrodes are difficult to twist due to the strength of the electric field strength, which causes a decrease in display brightness.

The present invention has been made to solve at least part of the problems described above, it can be implemented deliberately following form.

The liquid crystal display device according to the present invention comprises first and second substrates sandwiching a liquid crystal layer, is formed on the liquid crystal layer side of the first substrate, a first electrode having a linear portion, the lines of the first electrode Jo portion and planarly case adjacent at a distance Utotomoni, a second electrode having a linear portion formed along the linear portion of the first electrode, a transparent conductive a liquid crystal layer side of the second substrate formed by gender material, linear portion and with spatially overlaps the second electrode, have a linear portion formed in the longitudinal direction along the scan lines or signal lines formed on the first substrate, the second electrode A third electrode set to a potential, an intermediate potential between the first electrode and the second electrode, a fixed potential, or at least one potential in a floating state; and a first substrate from the first electrode and the second electrode On the side, a linear portion is formed so as to overlap the linear portion of the first electrode in a plane via an insulating film. A fourth electrode electrically connected to the second electrode, and adjacent to the linear portion of the fourth electrode at a distance in a plane along the linear portion of the fourth electrode; It has a linear portion and a linear portion formed so as to overlap in plan view of the second electrode, a fifth electrode connected to the first electrode and electrically, comprising a first electrode, a second electrode during, Ru cause different directions of electric field and between the fourth electrode and the third electrode.

  According to this, the linear portions of the first electrode and the second electrode are formed adjacent to each other with a space in between, and correspond to the pixel electrode and the counter electrode of the IPS mode liquid crystal display device. The term “parallel” in the present invention does not necessarily need to be completely parallel as long as they do not intersect with each other, and is used to include a “<” shape or a zigzag shape.

The linear portion of the second electrode is formed to overlap the linear portion of the third electrode in a plan view, and an electric field is generated between the first electrode and the third electrode. Therefore, in addition to the lateral electric field between the linear part of the first electrode and the linear part of the second electrode, the liquid crystal molecules are caused by the electric field between the linear part of the first electrode and the linear part of the third electrode. It can be moved and can be displayed brightly without increasing the driving voltage. Thus, improved brightness (increase) and improved driving voltage (low driving voltage) is made possible.

Since the third electrode is formed of a transparent conductive material, light from the backlight is not blocked by the third electrode, and a bright display liquid crystal display device can be obtained . As the transparent conductive material, a known material such as ITO or IZO can be used.

In addition , by setting the potential of the third electrode to a specified potential, it is possible to prevent the linear portion of the third electrode from disturbing the alignment of the liquid crystal.

Furthermore , since the third electrode can be formed effectively even in the vicinity of the switching element, the aperture ratio can be increased without waste.

In addition , a capacitance is formed by each of two pairs of electrode pairs overlapping in plan via an insulating film, and these capacitances are connected in parallel. As a result, a larger storage capacitor is formed than in the conventional FFS mode liquid crystal display device, so that a liquid crystal display device with less flicker can be obtained. In addition, since all the electrodes can drive the liquid crystal in the FFS mode, bright display is possible, and the symmetry of the electrodes is an intermediate configuration between the IPS mode and the FFS mode, and a DC component is generated. Is reduced and the image sticking phenomenon is also improved. In this manner, an FFS mode liquid crystal display device having the characteristics of the IPS mode that is difficult to cause image sticking and flicker, has a large aperture ratio, and can display brightly is obtained.

Linear portion of the linear portion及beauty fifth electrode of the fourth electrode of the upper Symbol liquid crystal display device, is thicker than the linear portion of the linear portion及beauty second electrode of the first electrode width, respectively it It may be .

  According to this, since the characteristics of the FFS mode liquid crystal display device appear strongly, a high applied voltage is required, but since a good fringe field effect occurs in all the electrodes, a brighter display liquid crystal display device can be obtained. can get. In addition, when manufacturing the liquid crystal display device according to such an aspect, the tolerance for misalignment is increased, which makes it easier to manufacture.

Linear portion of the fourth electrode line portion及beauty fifth electrode of the upper Symbol liquid crystal display device, the width is the same as the linear portion of the linear portion及beauty second electrode of the first electrode, respectively it It may be .

  According to this, the tolerance for the positional deviation of the mask at the time of manufacture is reduced, but the applied voltage may be low, and a fringe field is generated in all the electrodes, so that a bright display liquid crystal display device can be obtained.

The electronic device may be mounted on SL liquid crystal display device on the display unit.

  According to this, by providing the liquid crystal display device in the display unit, high-quality display can be performed on the display unit.

  Hereinafter, an embodiment of a liquid crystal display device will be described with reference to the drawings. In the drawings referred to in each embodiment, each layer and each member are displayed in different scales so that each layer and each member have a size that can be recognized on the drawing.

(First embodiment)
FIG. 1 is a circuit configuration diagram of a plurality of sub-pixel regions formed in a matrix that constitutes the liquid crystal display device 2 according to the present embodiment.

  In the image display area of the liquid crystal display device 2 according to the present embodiment, a plurality of sub-pixel areas are arranged in a matrix. In each subpixel region, a first electrode 10 and a TFT 12 for controlling the switching of the first electrode 10 are formed. A signal line 16 extending from the signal line driving circuit 14 is electrically connected to the source of the TFT 12. The signal line driving circuit 14 supplies image signals S1, S2,..., Sn to the respective pixels via the signal line 16. The image signals S1 to Sn may be supplied line-sequentially in this order, or may be supplied for each of a plurality of signal lines 16 adjacent to each other.

  A scanning line 20 extending from the scanning line driving circuit 18 is electrically connected to the gate of the TFT 12. The scanning line driving circuit 18 supplies scanning signals G1, G2,..., Gm to the scanning line 20 in a pulse manner at a predetermined timing. The scanning signals G1 to Gm are applied to the gate of the TFT 12 in line order in this order. On the other hand, the first electrode 10 is electrically connected to the drain of the TFT 12. Then, when the scanning signals G1, G2,..., Gm are input and the TFT 12 as a switching element is turned on for a certain period, the image signals S1, S2,. At this timing, data is written to the first electrode 10.

  Image signals S1, S2,..., Sn written to the liquid crystal through the first electrode 10 are held for a certain period by a liquid crystal capacitor formed between the first electrode 10 and the common electrode. Here, in order to prevent the held image signal from leaking, the storage capacitor 22 is formed in parallel with the liquid crystal capacitor. The storage capacitor 22 is provided between the drain of the TFT 12 and the capacitor line 24.

Next, the plane and cross-sectional configuration of the liquid crystal display device 2 will be described with reference to FIGS.
FIG. 2 is a plan view of an arbitrary sub-pixel represented by seeing through the color filter substrate CF of the liquid crystal display device 2 according to the present embodiment. 3 is a partial cross-sectional configuration diagram taken along the line III-III ′ in FIG. 2, and FIG. 4 is a partial cross-sectional configuration diagram along the line IV-IV ′ in FIG. 2.

  In the sub-pixel region of the liquid crystal display device 2 according to the present embodiment, a color filter layer 26 having substantially the same planar shape as the sub-pixel region is provided. Further, a columnar spacer 28 for keeping the liquid crystal layer thickness (cell gap) constant by separating the array substrate AR and the color filter substrate CF at a predetermined interval is provided at the lower right corner of the sub-pixel region. It is installed.

  The liquid crystal display device 2 includes an array substrate (first substrate) AR and a color filter substrate (second substrate) CF. The array substrate AR crosses the surface of the display region of the first transparent substrate 30 such as a glass substrate in a state where a plurality of scanning lines 20 and signal lines 16 are insulated from each other by a gate insulating film 32 in a matrix. In addition, a common wiring 34 is formed on the peripheral edge of the display area. Each region surrounded by the scanning line 20 and the signal line 16 forms each pixel (also referred to as “sub-pixel”). In addition, on the first transparent substrate 30, for example, a TFT 12 is formed as a switching element for each pixel. In the TFT 12, a semiconductor layer 36 is disposed on the surface of the scanning line 20, and a part of the signal line 16 is extended so as to cover a part of the surface of the semiconductor layer 36 to constitute a source electrode S. The scanning line portion below the gate electrode G constitutes a gate electrode G, and the conductive layer overlapping a part of the semiconductor layer 36 constitutes a drain electrode D. The drain electrode D is connected to the first electrode 10. . The entire surface of the first transparent substrate 30 including the TFT 12 is covered with a passivation film 38 made of, for example, a silicon nitride layer or a silicon oxide layer.

  A planarizing film 40 made of an organic material is formed on the surface of the passivation film 38, and a silicon nitride layer or silicon oxide is formed on the surface of the planarizing film 40 over the entire surface of the first transparent substrate 30. An insulating film 42 made of layers is formed. In the insulating film 42, the planarizing film 40, and the passivation film 38, a first contact hole 44 is formed at a position corresponding to the drain electrode D of the TFT 12. A linear shape extending along the signal line 16 is arranged on the surface of the insulating film 42 so as to be arranged in parallel with each pixel across the first separation region 46 (adjacently spaced apart in plan view). A first electrode 10 and a second electrode 48 having portions 10a and 48a, respectively, are formed. The first electrode 10 has a plurality of linear portions 10a, and has a longitudinal direction in the Y-axis direction (signal line 16 / extending direction of wiring for supplying signals). The second electrode 48 includes a plurality of linear portions 48a and has a longitudinal direction in the Y-axis direction. The first electrode 10 and the second electrode 48 are preferably formed of a transparent conductive material such as ITO or IZO in order to increase the aperture ratio so that a bright display can be achieved. It can also be formed.

  The first electrode 10 is electrically connected to the drain electrode D of the TFT 12 via the first contact hole 44, and the second electrode 48 is connected to the common wiring 34 via the second contact hole 50 formed in the insulating film 42. Is electrically connected. Therefore, in the liquid crystal display device 2, the first electrode 10 functions as a pixel electrode, and the second electrode 48 functions as a counter electrode.

  For this reason, the pairs of the linear portions 10a of the first electrodes 10 and the linear portions 48a of the second electrodes 48 that are adjacent to each other in the same plane have an arrangement relationship of the liquid crystal display device in the IPS mode. Note that which of the first electrode 10 and the second electrode 48 is to be the pixel electrode is arbitrary. However, adjacent electrode pairs in the same plane must be a pair of a pixel electrode and a counter electrode.

  A first alignment film 52 is formed over the entire display region including the surfaces of the first electrode 10 and the second electrode 48.

  The color filter substrate CF corresponds to the scanning line 20, the signal line 16, the first contact hole 44, the second contact hole 50, and the TFT 12 of the array substrate AR on the surface of the second transparent substrate 54 such as a glass substrate. A light shielding film 56 is formed so as to cover the position. Further, a color filter layer 26 of a predetermined color is formed on the surface of the second transparent substrate 54 surrounded by the light shielding film 56. An overcoat layer 58 is formed so as to cover the surfaces of the light shielding film 56 and the color filter layer 26.

  A patterned third electrode 60 made of an ITO film is formed on each pixel on the overcoat layer 58. With such a configuration, the third electrode 60 formed on the surface of the overcoat layer 58 is flattened by unevenness due to the presence of, for example, the color filter layer 26, so that the cell gap is made uniform. Therefore, according to the liquid crystal display device 2 of the aspect, a liquid crystal display device having a good display image quality can be obtained. The third electrode 60 has a plurality of linear portions 60a and has a longitudinal direction in the Y-axis direction. Each linear portion 60a of the third electrode 60 is disposed so as to overlap with each linear portion 48a of the second electrode 48 in a plan view. The third electrode 60 is provided with slits so as to overlap each linear portion 10a of the first electrode 10 in a planar manner. With such a configuration, the third electrode 60 can be effectively formed in the vicinity of the TFT 12 and the like, so that the aperture ratio can be increased without waste.

  As the potential of the third electrode 60, at least one of the same potential as the second electrode 48, an intermediate potential between the first electrode 10 and the second electrode 48, a fixed potential, a floating state, and the like is given. With such a configuration, by setting the potential of the third electrode 60 to a predetermined potential, it is possible to prevent each linear portion 60a of the third electrode 60 from disturbing the alignment of the liquid crystal LC. Further, a pulsed potential may be applied to the third electrode 60. With such a configuration, high-speed response can be achieved.

  The third electrode 60 may be applied with a predetermined potential in addition to a floating state in terms of potential. In applying a predetermined potential to the third electrode 60, the third electrode 60 formed on the liquid crystal LC side of the color filter substrate CF and the wiring (not shown) formed on the array substrate AR are electrically connected. On the other hand, when the third electrode 60 is in a floating state, the conduction between the substrates is omitted. The third electrode 60 is preferably formed of a transparent conductive material such as ITO or IZO in order to increase the aperture ratio and enable bright display, but is formed of a metal material such as aluminum. You can also.

  A second alignment film 64 is formed on the surfaces of the overcoat layer 58 and the third electrode 60.

  The array substrate AR and the color filter substrate CF are opposed so that the linear portions 48a of the second electrode 48 of the array substrate AR and the linear portions 60a of the third electrode 60 of the color filter substrate CF are opposed to each other. In the meantime, liquid crystal LC is sealed. As a material for the liquid crystal LC, either a liquid crystal material having a negative dielectric anisotropy or a positive liquid crystal material may be used, but a liquid crystal material having a negative dielectric anisotropy is preferably used. This is because when a liquid crystal material having a negative dielectric anisotropy is used, the viewing angle when a selection voltage is applied (voltage on) can be widened so that the display characteristics of the display device are not impaired. Further, by using a liquid crystal having a negative dielectric anisotropy of the liquid crystal, it is possible to reduce the influence of the vertical electric field due to the misalignment, and to improve the tolerance for the misalignment. Furthermore, in each linear part 60a of the third electrode 60, in order to minimize the influence of the misalignment, an electrode that applies a potential by the misalignment may be selected. Further, the influence of the misalignment may be minimized by arbitrarily shifting the interval between the linear portions 60a of the third electrode 60 within one pixel.

  Then, the first polarizing plate 66 and the backlight device (not shown) are arranged outside the array substrate AR, and the second polarizing plate 68 is arranged outside the color filter substrate CF to complete the liquid crystal display device 2. A retardation plate may be disposed between the substrates AR and CF and the polarizing plates 66 and 68 as necessary.

Next, the operation of the liquid crystal display device 2 will be described.
In the liquid crystal display device 2, the first electrode 10 functions as a pixel electrode, and the second electrode 48 and the third electrode 60 operate as counter electrodes. Then, the linear portions 48 a of the second electrode 48 and the linear portions 60 a of the third electrode 60 overlap each other in a plane via the first alignment film 52, the liquid crystal LC, and the second alignment film 64. Therefore, when the liquid crystal display device 2 is activated, an electric field E1 is generated between each linear portion 10a of the first electrode 10 and each linear portion 48a of the second electrode 48, as shown in FIG. An electric field E <b> 2 is applied between each linear portion 10 a of the first electrode 10 and each linear portion 60 a of the third electrode 60.

  Liquid crystal molecules can be moved by an electric field E2 applied between each linear portion 10a of the first electrode 10 and each linear portion 60a of the third electrode 60. The operation by the electric field E1 applied between each linear portion 10a of the first electrode 10 and each linear portion 48a of the second electrode 48 is the IPS mode liquid crystal display of the conventional example shown in FIGS. This is the same as the case of the device 150. Therefore, the liquid crystal display device 2 operates as an IPS mode liquid crystal display device between each linear portion 10 a of the first electrode 10 and each linear portion 48 a of the second electrode 48.

(Transparency vs. drive voltage characteristics)
FIG. 5 is a graph of transmittance T-driving voltage V characteristics between the liquid crystal display device 2 according to the present embodiment and a conventional liquid crystal display device having an IPS structure. The graph L1 is the transmittance T-drive voltage V characteristic of the liquid crystal display device 2, and the graph L2 is the transmittance T-drive voltage V characteristic of the conventional IPS mode liquid crystal display device.

  When the graphs L1 and L2 of the transmittance T-driving voltage V characteristics are compared, the light transmittance when the selection voltage Vs is applied is higher in the liquid crystal display device 2 than in the conventional IPS mode liquid crystal display device. ing.

  According to this embodiment, in addition to the transverse electric field E1 between each linear portion 10a of the first electrode 10 and each linear portion 48a of the second electrode 48, each linear portion 10a of the first electrode 10 and the third electrode 60 are provided. The liquid crystal molecules can be moved by the electric field E2 between the linear portions 60a, and bright display can be achieved without increasing the drive voltage. As a result, the transmittance can be improved without making the first separation region 46 on the array substrate AR side too small. In this way, the liquid crystal display device 2 that can improve (improve) the brightness and improve the driving voltage (low driving voltage) is provided.

(Second Embodiment)
Next, the liquid crystal display device 4 according to the second embodiment will be described with reference to FIGS.
FIG. 6 is a plan view of an arbitrary sub-pixel represented by seeing through the color filter substrate CF of the liquid crystal display device 4 according to the present embodiment. 7 is a partial cross-sectional configuration diagram taken along line VII-VII ′ in FIG. 6, and FIG. 8 is a partial cross-sectional configuration diagram along line VIII-VIII ′ in FIG. 6. 6 to 8, the same components as those of the liquid crystal display device 2 of the first embodiment shown in FIGS. 2 to 4 are denoted by the same reference numerals, and detailed description thereof is omitted. .

  The liquid crystal display device 4 according to the present embodiment differs in configuration from the liquid crystal display device 2 of the first embodiment through the insulating film 42 in addition to the first and second electrodes 10 and 48 on the array substrate AR side. The fourth and fifth electrodes 70 and 72 of the lower electrode are formed.

  The liquid crystal display device 4 includes first and second linear portions 70 a and 72 a extending along the signal line 16 so as to be arranged in parallel with each pixel with the second separation region 74 interposed therebetween on the surface of the planarization film 40. Four electrodes 70 and a fifth electrode 72 are formed. The fourth electrode 70 has a plurality of linear portions 70a and has a longitudinal direction in the Y-axis direction. The fifth electrode 72 has a plurality of linear portions 72a and has a longitudinal direction in the Y-axis direction. One of the pair of fourth electrode 70 and fifth electrode 72 may be made of a metal material such as aluminum, but at least one of them is transparent such as ITO or IZO in order to increase the aperture ratio. It is preferable to be made of a conductive material.

  The fifth electrode 72 is electrically connected to the drain electrode D of the TFT 12 through the first contact hole 44, and the fourth electrode 70 is electrically connected to the common wiring 34. Accordingly, the fifth electrode 72 functions as a pixel electrode, and the fourth electrode 70 functions as a counter electrode.

  An insulating film 42 made of a silicon nitride layer or a silicon oxide layer is formed over the entire surface of the first transparent substrate 30 on which the fourth electrode 70 and the fifth electrode 72 are formed. On the surface of the insulating film 42, the first electrode 10 and the second electrode 10 each have linear portions 10 a and 48 a extending along the signal line 16 so as to be arranged in parallel with each pixel across the first separation region 46. An electrode 48 is formed. Each linear portion 10a of the first electrode 10 and each linear portion 48a of the second electrode 48 are formed so as to overlap each linear portion 72a of the fifth electrode 72 and each linear portion 70a of the fourth electrode 70 in a plane. Has been.

  Here, the widths of the linear portions 70 a of the fourth electrode 70 and the linear portions 72 a of the fifth electrode 72 are larger than the widths of the linear portions 10 a of the first electrode 10 and the linear portions 48 a of the second electrode 48. It is formed as follows. With such a configuration, the tolerance for the positional deviation of the mask when the first electrode 10 and the second electrode 48 are formed on the surface of the insulating film 42 by the photolithography method is increased, which facilitates the manufacture. The widths of the linear portions 70 a of the fourth electrode 70 and the linear portions 72 a of the fifth electrode 72 are the same as the widths of the linear portions 10 a of the first electrode 10 and the linear portions 48 a of the second electrode 48. It may be formed. With such a configuration, the tolerance for the positional deviation of the mask at the time of manufacture is reduced, but the applied voltage may be low, and a fringe field is generated in all the electrodes. Is obtained. In particular, the widths of the linear portions 70a of the fourth electrode 70 and the linear portions 72a of the fifth electrode 72 are changed, and the widths of the linear portions 10a of the first electrode 10 and the linear portions 48a of the second electrode 48 are changed. There is no advantage to changing each other. Therefore, the widths of the linear portions 70a of the fourth electrode 70 and the linear portions 72a of the fifth electrode 72 are made substantially the same, and the linear portions 10a of the first electrode 10 and the lines of the second electrode 48 are arranged. The widths of the shaped portions 48a may be formed so as to be substantially the same.

  The fifth electrode 72 is electrically connected to the drain electrode D of the TFT 12 through the first contact hole 44 and is also electrically connected to the first electrode 10. The fourth electrode 70 is electrically connected to the second electrode 48 through the second contact hole 50.

  Therefore, a pair consisting of the linear portions 10a of the first electrode 10 and the linear portions 70a of the fourth electrode 70 that overlap in plan view, and the linear portions 48a of the second electrode 48 and the linear portions 72a of the fifth electrode 72, The pair consisting of is in the same arrangement relationship as in the case of the conventional FFS mode liquid crystal display device 190 shown in FIGS. Further, a pair consisting of each linear portion 10a of the first electrode 10 and each linear portion 48a of the second electrode 48 which are adjacent on the same plane, and each linear portion 70a of the fourth electrode 70 and each linear portion 72a of the fifth electrode 72. Are in the same positional relationship as the conventional IPS mode liquid crystal display device 150 shown in FIGS.

  On the color filter substrate CF, a third electrode 60 made of an ITO film is formed on the light shielding film 56 and the color filter layer 26.

Next, the operation of the liquid crystal display device 4 will be described.
In the liquid crystal display device 4, the first electrode 10 and the fifth electrode 72 function as pixel electrodes, and the second electrode 48, the fourth electrode 70, and the third electrode 60 operate as counter electrodes. The linear portions 10a of the first electrode 10 and the linear portions 70a of the fourth electrode 70 are planarly overlapped via the insulating film 42, and the linear portions 48a of the second electrode 48 and the fifth electrode 72 are overlapped. The linear portions 72a of the second electrode 48 and the linear portions 60a of the third electrode 60 are planarly overlapped with each other through the insulating film 42 in a plane. The liquid crystal LC and the second alignment film 64 are overlapped with each other. Therefore, when the liquid crystal display device 4 is activated, an electric field E1 is generated between each linear portion 10a of the first electrode 10 and each linear portion 48a of the second electrode 48, as shown in FIG. There is an electric field E2 between each linear portion 10a of one electrode 10 and each linear portion 60a of the third electrode 60, and between each linear portion 10a of the first electrode 10 and each linear portion 70a of the fourth electrode 70. Is applied with an electric field E3. Further, an electric field E4 in a direction opposite to the electric field E3 is applied between each linear portion 72a of the fifth electrode 72 and each linear portion 48a of the second electrode 48.

  Liquid crystal molecules can be moved by an electric field E2 applied between each linear portion 10a of the first electrode 10 and each linear portion 60a of the third electrode 60. The operation by the electric field E1 applied between each linear portion 10a of the first electrode 10 and each linear portion 48a of the second electrode 48 is the IPS mode liquid crystal display of the conventional example shown in FIGS. The same as in the case of the apparatus. Accordingly, the liquid crystal display device 4 operates as an IPS mode liquid crystal display device between each linear portion 10 a of the first electrode 10 and each linear portion 48 a of the second electrode 48. Further, the operation by the electric field E3 applied between each linear portion 10a of the first electrode 10 and each linear portion 70a of the fourth electrode 70 and each linear shape of each linear portion 72a of the fifth electrode 72 and each second electrode 48. The operation by the electric field E4 applied to the part 48a is the same as that of the conventional FFS mode liquid crystal display device shown in FIGS. Accordingly, the FFS mode is established between each linear portion 10a of the first electrode 10 and each linear portion 70a of the fourth electrode 70 and between each linear portion 48a of the second electrode 48 and each linear portion 72a of the fifth electrode 72. It will operate as a liquid crystal display device.

(Transparency vs. drive voltage characteristics)
FIG. 9 is a graph of transmittance T-driving voltage V characteristics between the liquid crystal display device 4 according to the present embodiment and a conventional FFS structure liquid crystal display device. The graph L3 is the transmittance T-drive voltage V characteristic of the liquid crystal display device 4, and the graph L4 is the transmittance T-drive voltage V characteristic of the conventional FFS mode liquid crystal display device.

  When the graphs L3 and L4 of the transmittance T-driving voltage V characteristics are compared, the light transmittance when the selection voltage Vs is applied is higher in the liquid crystal display device 4 than in the conventional FFS mode liquid crystal display device. ing.

  According to this embodiment, each linear part 10a of the first electrode 10 is each linear part 70a of the fourth electrode 70, each linear part 48a of the second electrode 48 is each linear part 72a of the fifth electrode 72, respectively. In addition, the fourth electrode 70 is electrically connected to the second electrode 48, and the fifth electrode 72 is electrically connected to the first electrode 10. Therefore, two sets of electrode pairs that overlap in a plane via the insulating film 42 have the same arrangement relationship as in the case of the FFS mode liquid crystal display device, and adjacent electrode pairs in the same plane are the same in the IPS mode liquid crystal display device. The arrangement relationship is the same as in the case.

  As a result, a capacitance is formed by each of the two electrode pairs that overlap in plan via the insulating film 42, and these capacitances are connected in parallel. Therefore, as a result, a larger storage capacitor is formed than in the conventional FFS mode liquid crystal display device, so that the liquid crystal display device 4 with less flicker can be obtained. In addition, since all the electrodes can drive the liquid crystal in the FFS mode, bright display is possible, and the symmetry of the electrodes is an intermediate configuration between the IPS mode and the FFS mode, and a DC component is generated. Is reduced and the image sticking phenomenon is also improved. In this manner, the FFS mode liquid crystal display device 4 having the characteristics of the IPS mode that is difficult to cause image sticking and flicker, has a large aperture ratio, and can display brightly is obtained.

(Third embodiment)
Next, a liquid crystal display device 6 according to a third embodiment will be described with reference to FIG.
FIG. 10 is a plan view of an arbitrary sub-pixel represented by seeing through the color filter substrate CF of the liquid crystal display device 6 according to the present embodiment. In FIG. 10, the same components as those of the liquid crystal display device 4 of the second embodiment shown in FIG. 6 are denoted by the same reference numerals, and detailed description thereof is omitted. 10 are the same as those in FIGS. 7 and 8, respectively, and the illustration and detailed description thereof are omitted.

  The liquid crystal display device 6 according to this embodiment is different from the liquid crystal display device 4 according to the second embodiment in that the liquid crystal display device 4 according to the second embodiment has each linear portion 10a of the first electrode 10 and Each linear portion 48 a of the second electrode 48 extends straight along the signal line 16. However, in the liquid crystal display device 6 of the present embodiment, each linear portion 10 a of the first electrode 10 and each linear shape of the second electrode 48. The center of each linear part 70a of the part 48a, the fourth electrode 70, and each linear part 72a of the fifth electrode 72 is bent. Further, each linear portion 60a of the third electrode 60 arranged so as to overlap with each linear portion 48a of the second electrode 48 in a plan view is also formed so that the center is bent.

  In the liquid crystal display device 6, the linear portions 10 a, 48 a, 60 a, 70 a, 72 a of the first to fifth electrodes 10, 48, 60, 70, 72 are formed in a “character shape” with the center of the pixel as a boundary. The so-called dual domain is arranged, and the rotation direction of the liquid crystal molecules is the rotation direction of the liquid crystal molecules in the upper half region as viewed from the front side of the paper with the center of the pixel as the boundary, and from the front side of the paper surface. Thus, the rotation directions of the liquid crystal molecules in the lower half region are opposite to each other.

  According to this embodiment, by providing a dual-domain electrode structure, it is possible to suppress a color shift such as yellowishness or blueness depending on the viewing angle.

(Fourth embodiment)
Next, a liquid crystal display device 8 according to a fourth embodiment will be described with reference to FIGS.
FIG. 11 is a plan view of an arbitrary sub-pixel represented by seeing through the color filter substrate CF of the liquid crystal display device 8 according to the present embodiment. FIG. 12 is a partial cross-sectional configuration diagram taken along line XII-XII ′ in FIG. 11, and FIG. 13 is a partial cross-sectional configuration diagram taken along line XIII-XIII ′ in FIG. In FIG. 11 to FIG. 13, the same components as those of the liquid crystal display device 6 of the third embodiment shown in FIG. 10, FIG. 7, and FIG. Description is omitted.

  The configuration of the liquid crystal display device 8 according to the present embodiment is different from the configuration of the liquid crystal display device 6 of the third embodiment in that the liquid crystal display device 8 on the color filter substrate CF side in addition to the configuration of the liquid crystal display device 6 of the third embodiment. The sixth electrode 78 is provided with a potential different from that of the three electrodes 60.

  In the liquid crystal display device 8, a patterned sixth electrode 78 made of an ITO film is formed on each pixel on the overcoat layer 58. The sixth electrode 78 has a plurality of linear portions 78a and has a longitudinal direction in the Y-axis direction. Each linear portion 78 a of the sixth electrode 78 extends along the signal line 16 so as to be arranged in parallel with each linear portion 60 a of the third electrode 60 and the third separation region 80 interposed therebetween. Each linear portion 78a of the sixth electrode 78 is disposed so as to overlap with each linear portion 10a of the first electrode 10 in a plan view. The sixth electrode 78 is provided with slits so as to overlap each linear portion 48 a of the second electrode 48 in a planar manner.

  As the potential of the sixth electrode 78, at least one of the same potential as the first electrode 10, an intermediate potential between the first electrode 10 and the second electrode 48, a fixed potential, a floating state, and the like is given. With such a configuration, by setting the potential of the sixth electrode 78 to a predetermined potential, it is possible to prevent each linear portion 78a of the sixth electrode 78 from disturbing the alignment of the liquid crystal LC. Further, a pulsed potential may be applied to the sixth electrode 78. With such a configuration, high-speed response can be achieved.

  The sixth electrode 78 may be applied with a predetermined potential in addition to being in a floating state in terms of potential. In applying a predetermined potential to the sixth electrode 78, the sixth electrode 78 formed on the liquid crystal LC side of the color filter substrate CF and the wiring (not shown) formed on the array substrate AR are electrically connected. On the other hand, when the sixth electrode 78 is in a floating state, the conduction between the substrates is omitted. The sixth electrode 78 is preferably formed of a transparent conductive material such as ITO or IZO in order to increase the aperture ratio and enable bright display, but is formed of a metal material such as aluminum. You can also. In addition, in each linear portion 78a of the sixth electrode 78, in order to minimize the influence of misalignment, an electrode that applies a potential by misalignment may be selected. Further, the influence of the misalignment may be minimized by arbitrarily shifting the interval between the linear portions 78a of the sixth electrode 78 within one pixel.

  A second alignment film 64 is formed on the surfaces of the overcoat layer 58, the third electrode 60, and the sixth electrode 78.

  Then, each linear portion 10a of the first electrode 10 and each linear portion 48a of the second electrode 48 of the array substrate AR, and each linear portion 78a of the sixth electrode 78 and each linear portion of the third electrode 60 of the color filter substrate CF. The array substrate AR and the color filter substrate CF are opposed to each other so that 60a is opposed to each other, and the liquid crystal LC is sealed therebetween.

Next, the operation of the liquid crystal display device 8 will be described.
In the liquid crystal display device 8, the first electrode 10, the fifth electrode 72, and the sixth electrode 78 function as pixel electrodes, and the second electrode 48, the fourth electrode 70, and the third electrode 60 operate as counter electrodes. . The linear portions 10a of the first electrode 10 and the linear portions 70a of the fourth electrode 70 are planarly overlapped via the insulating film 42, and the linear portions 48a of the second electrode 48 and the fifth electrode 72 are overlapped. The linear portions 72a of the first electrode 10 and the linear portions 78a of the sixth electrode 78 are planarly overlapped with each other through the insulating film 42 in a plane. The liquid crystal LC and the second alignment film 64 are overlapped with each other, and each linear portion 48a of the second electrode 48 and each linear portion 60a of the third electrode 60 are planarly arranged with the first alignment film 52, the liquid crystal LC, and It overlaps with the second alignment film 64 interposed therebetween. Therefore, when the liquid crystal display device 8 is activated, an electric field E1 is generated between each linear portion 10a of the first electrode 10 and each linear portion 48a of the second electrode 48, as shown in FIG. There is an electric field E2 between each linear portion 10a of the first electrode 10 and each linear portion 60a of the third electrode 60, and between each linear portion 10a of the first electrode 10 and each linear portion 70a of the fourth electrode 70. The electric field E3 is applied between the linear portions 72a of the fifth electrode 72 and the linear portions 48a of the second electrode 48. The electric field E4 in the direction opposite to the electric field E3 is applied to the linear portions 60a of the third electrode 60. And an electric field E <b> 5 is applied between the linear portions 78 a of the sixth electrode 78. Further, an electric field E6 in a direction opposite to the electric field E2 is applied between each linear portion 78a of the sixth electrode 78 and each linear portion 48a of the second electrode 48.

  Liquid crystal molecules can be moved by an electric field E2 applied between each linear portion 10a of the first electrode 10 and each linear portion 60a of the third electrode 60. Further, the liquid crystal molecules can be moved by the electric field E6 applied between the linear portions 78a of the sixth electrode 78 and the linear portions 48a of the second electrode 48. Further, the operation by the electric field E1 applied between each linear portion 10a of the first electrode 10 and each linear portion 48a of the second electrode 48, and each linear shape of each linear portion 78a of the sixth electrode 78 and the third electrode 60. The operation by the electric field E5 applied to the unit 60a is the same as that of the conventional IPS mode liquid crystal display device shown in FIGS. Therefore, the liquid crystal display device 8 includes the linear portions 10 a of the first electrode 10 and the linear portions 48 a of the second electrode 48 and the linear portions 78 a of the sixth electrode 78 and the linear portions 60 a of the third electrode 60. And operate as an IPS mode liquid crystal display device. Further, the operation by the electric field E3 applied between each linear portion 10a of the first electrode 10 and each linear portion 70a of the fourth electrode 70 and each linear shape of each linear portion 72a of the fifth electrode 72 and each second electrode 48. The operation by the electric field E4 applied to the part 48a is the same as that of the conventional FFS mode liquid crystal display device shown in FIGS. Accordingly, the FFS mode is established between each linear portion 10a of the first electrode 10 and each linear portion 70a of the fourth electrode 70 and between each linear portion 48a of the second electrode 48 and each linear portion 72a of the fifth electrode 72. It will operate as a liquid crystal display device.

  According to the present embodiment, the electric field E5 between each linear portion 60a of the third electrode 60 on the color filter substrate CF side and each linear portion 78a of the sixth electrode 78 and each linear portion 78a of the sixth electrode 78 and the The liquid crystal molecules can be moved by the electric field E6 between the linear portions 48a of the two electrodes 48, and bright display can be achieved without increasing the driving voltage.

(Electronics)
Next, an electronic device including the above-described liquid crystal display device will be described.
FIG. 14 is a perspective view of a mobile phone 100 which is an example of an electronic apparatus in which the liquid crystal display device according to this embodiment is mounted on a display unit.

  A cellular phone 100 according to the present embodiment includes the liquid crystal display device of the above-described embodiment as a small-sized display unit 102, and includes a plurality of operation buttons 104, an earpiece 106, and a mouthpiece 108. Since the mobile phone 100 includes the liquid crystal display device of the above-described embodiment, it is possible to provide an electronic device with excellent display quality.

  The liquid crystal display device of the above embodiment is not limited to the mobile phone, but is an electronic book, personal computer, digital still camera, liquid crystal television, viewfinder type or monitor direct view type video tape recorder, car navigation device, pager, electronic It can be suitably used as image display means for devices such as notebooks, calculators, word processors, workstations, videophones, POS terminals, touch panels, etc., and any electronic device can provide electronic devices with excellent display quality. .

  The embodiment has been described above. As a modification, for example, the following can be considered.

(Modification 1)
In the liquid crystal display device of the above embodiment, the example in which each linear portion 60a of the third electrode 60 and each linear portion 78a of the sixth electrode 78 have the longitudinal direction along the signal line 16 is shown. Even if it has the longitudinal direction, the same effect is obtained.

(Modification 2)
In the liquid crystal display device of the above embodiment, an example in which there is no shield electrode normally used on the color filter substrate side is shown, but a shield electrode may be provided on the color filter substrate side. For example, in a normal horizontal electric field type liquid crystal display device, since there is no conductor on the color filter substrate side, it is necessary to provide a shield electrode as a countermeasure against static electricity. Therefore, a shield electrode is unnecessary. Even when a shield electrode for preventing electrostatic charging from being formed on the color filter substrate CF is formed, each linear portion 60a of the patterned third electrode 60 is formed. It is difficult to be charged due to, and even if charged, the orientation of the liquid crystal is not disturbed. Further, since each linear portion 60a of the patterned third electrode 60 is formed on the liquid crystal LC side of the color filter substrate CF, the patterned electrode can be formed in the state of the substrate before the liquid crystal panel is assembled. it can.

(Modification 3)
The liquid crystal display device of the above embodiment is a transmissive liquid crystal display device, but is not limited to this, and may be, for example, a reflective or transflective liquid crystal display device.

FIG. 3 is a circuit configuration diagram of a plurality of sub-pixel regions formed in a matrix that constitutes the liquid crystal display device according to the first embodiment. FIG. 3 is a plan view of an arbitrary one sub-pixel that is seen through a color filter substrate of the liquid crystal display device according to the first embodiment. FIG. 3 is a partial cross-sectional configuration diagram along line III-III ′ in FIG. 2. FIG. 4 is a partial cross-sectional configuration diagram taken along line IV-IV ′ in FIG. 2. The graph of the TV characteristic of the liquid crystal display device which concerns on 1st Embodiment, and the conventional IPS structure. FIG. 5 is a plan view of an arbitrary sub-pixel that is seen through a color filter substrate of a liquid crystal display device according to a second embodiment. FIG. 7 is a partial cross-sectional configuration diagram taken along line VII-VII ′ in FIG. 6. FIG. 7 is a partial cross-sectional configuration diagram taken along line VIII-VIII ′ in FIG. 6. The graph of the TV characteristic of the liquid crystal display device which concerns on 2nd Embodiment, and the conventional FFS structure. FIG. 10 is a plan view of an arbitrary sub-pixel that is seen through a color filter substrate of a liquid crystal display device according to a third embodiment. FIG. 10 is a plan view of an arbitrary sub-pixel represented by seeing through a color filter substrate of a liquid crystal display device according to a fourth embodiment. FIG. 12 is a partial cross-sectional configuration diagram taken along line XII-XII ′ in FIG. 11. FIG. 12 is a partial cross-sectional configuration diagram taken along line XIII-XIII ′ in FIG. 11. The perspective view of the mobile telephone which is an example of the electronic device which mounted the liquid crystal display device which concerns on this embodiment in the display part. FIG. 10 is a schematic plan view of one pixel that is seen through a color filter substrate of a conventional IPS mode liquid crystal display device. FIG. 16 is a cross-sectional view taken along line XVI-XVI ′ of FIG. FIG. 10 is a schematic plan view of one pixel that is seen through a color filter substrate of a conventional FFS mode liquid crystal display device. Sectional drawing along the XVIII-XVIII 'line | wire of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 2, 4, 6, 8 ... Liquid crystal display device 10 ... 1st electrode 10a ... Linear part 12 ... TFT 14 ... Signal line drive circuit 16 ... Signal line 18 ... Scan line drive circuit 20 ... Scan line 22 ... Storage capacity 24 ... Capacitor line 26 ... Color filter layer 28 ... Columnar spacer 30 ... First transparent substrate 32 ... Gate insulating film 34 ... Common wiring 36 ... Semiconductor layer 38 ... Passivation film 40 ... Flattening film 42 ... Insulating film 44 ... First contact hole 46 ... first separation region (separation region) 48 ... second electrode 48a ... linear portion 50 ... second contact hole 52 ... first alignment film 54 ... second transparent substrate 56 ... light-shielding film 58 ... overcoat layer 60 ... third Electrode 60a ... linear part 64 ... second alignment film 66 ... first polarizing plate 68 ... second polarizing plate 70 ... fourth electrode 70a ... linear part 72 ... fifth electrode 72a ... Jo portion 74 ... second separating area 78 ... sixth electrodes 78a ... linear portion 80 ... third spaced region 100 ... mobile phone 102 ... display unit 104 ... operation buttons 106 ... earpiece 108 ... mouthpiece.

Claims (4)

First and second substrates sandwiching a liquid crystal layer;
A first electrode formed on the liquid crystal layer side of the first substrate and having a linear portion;
A second electrode having a linear portion formed along the linear portion of the case Utotomoni, said first electrode adjacent at a plane spaced a linear portion of the first electrode,
It is formed of a transparent conductive material on the liquid crystal layer side of the second substrate, and overlaps the linear portion of the second electrode in a plan view, and is elongated along a scanning line or a signal line formed on the first substrate. have a linear portion forming the direction, the potential of the second electrode, an intermediate potential between the first electrode and the second electrode is set to a fixed potential, or the potential to at least one of the potential of the floating state a third electrode that,
A linear portion formed on the first substrate side of the first electrode and the second electrode so as to overlap the linear portion of the first electrode in a plane via an insulating film; A fourth electrode electrically connected to the electrode;
In the same layer as the linear portion of the fourth electrode, adjacent to the linear portion of the fourth electrode with a space in between, and overlaps the linear portion of the second electrode in a planar manner. A fifth electrode having a linear portion to be formed and electrically connected to the first electrode;
With
The first electrode between said second electrode, generates an electric field in the different directions between and between the fourth electrode of the previous SL third electrode,
Liquid crystal display device. The linear part of the fourth electrode and the linear part of the fifth electrode are wider than the linear part of the first electrode and the linear part of the second electrode, respectively.
The liquid crystal display device according to claim 1. The linear portion of the fourth electrode and the linear portion of the fifth electrode have the same width as the linear portion of the first electrode and the linear portion of the second electrode, respectively.
The liquid crystal display device according to claim 1. The liquid crystal display device according to any one of claims 1 to 3 is mounted on a display unit.
Electronics.

Images