JP2006235652A - Liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device such that the aperture ratio of a pixel region can be improved and a counter electrode and a counter voltage signal line can be connected with reliability. <P>SOLUTION: The counter voltage signal line which has its surface anodized and is made of Al or its alloy is formed below a laminate of a plurality of insulating layers, and the counter electrode made of a light-transmissive conductor is formed above the laminate of the plurality of insulating layers, covers gate signals line and drain signal lines to form a grating-shaped pattern, and is capacitively coupled with the counter voltage signal line through a through hole bored in the laminate of the plurality of insulating layers at a portion of the grating-shaped pattern. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device called a lateral electric field method.

  A liquid crystal display device called a horizontal electric field method is a counter electrode that generates an electric field between a pixel electrode and a pixel electrode in a pixel region on a liquid crystal side surface of one substrate of each substrate that is disposed to face the liquid crystal. The liquid crystal is made to behave by a component substantially parallel to the substrate in the electric field.

  In the case where such a configuration is applied to an active matrix type, first, a plurality of gate signal lines arranged in parallel on the liquid crystal side surface of the one substrate cross each of these gate signal lines. Each region surrounded by the plurality of drain signal lines arranged in parallel is used as the pixel region.

  Then, in each of these pixel regions, a thin film transistor operated by a scanning signal from a gate signal line, the pixel electrode to which a video signal from a drain signal line is supplied via the thin film transistor, and a reference to the video signal The counter electrode to which a signal is supplied is provided.

  Here, the pixel electrode and the counter electrode are each formed as a strip-like pattern extending in one direction, and these electrodes are usually formed in two or more and are alternately arranged.

  Further, in such a configuration, the counter electrode is formed on the upper surface of the insulating film formed so as to cover the drain signal line, and the central axis of the drain signal line is substantially coincident with the width of the drain signal line. A structure having a large width and formed along the drain signal line is also known.

  This is because electric lines of force from the drain signal line are easily terminated at the counter electrode above the drain signal line and are prevented from terminating at the pixel electrode. This is because if the electric lines of force terminate in the pixel electrode, it becomes noise.

  However, the liquid crystal display device having such a configuration requires a counter voltage signal line for supplying a signal to the counter electrode, which improves the so-called aperture ratio of the pixel region because it travels and is arranged in the pixel region. There was an inconvenience that it was a hindrance.

  Further, since the counter electrode and the counter voltage signal line are often arranged through an insulating layer, and their electrical connection is made through a small through hole formed in the insulating layer, further reliability of the connection is desired. It was. This is accompanied by the trend toward higher definition in recent years.

  The present invention has been made based on such circumstances, and an object thereof is to provide a liquid crystal display device in which the aperture ratio of the pixel region is improved.

  Another object of the present invention is to provide a liquid crystal display device in which a counter electrode and a counter voltage signal line are reliably connected.

Of the inventions disclosed in this application, the outline of typical ones will be briefly described as follows.
Means 1.
The liquid crystal display device according to the present invention includes, for example, a plurality of gate signal lines arranged in parallel on the liquid crystal side surface of one of the substrates opposed to each other through the liquid crystal and intersecting these gate signal lines. A region surrounded by a plurality of drain signal lines arranged in parallel is a pixel region,
In each of these pixel regions, a switching element operated by a scanning signal from a gate signal line, a pixel electrode to which a video signal from a drain signal line is supplied via the switching element, and the counter voltage signal line A counter electrode to which a reference signal is supplied with respect to the video signal is formed,
The counter electrode is formed in a lower layer of a stacked body of a plurality of insulating layers,
The counter voltage signal line is made of a non-translucent conductor, and is formed on an upper layer of the plurality of insulating layers, and forms a lattice pattern covering the gate signal line and the drain signal line, A part thereof is electrically connected to the counter electrode through a through hole formed in the laminate of the plurality of insulating layers.

Mean 2.
In the liquid crystal display device according to the present invention, for example, on the premise of the configuration of the means 1, the electrical connection between the counter voltage signal line and the counter electrode is a conduction that constitutes a pixel electrode formed between the plurality of insulating layers. It is characterized by being made through another conductive layer formed simultaneously with the layer.

Means 3.
In the liquid crystal display device according to the present invention, for example, on the premise of the configuration of the means 1, the electrical connection between the counter voltage signal line and the counter electrode constitutes a drain signal line formed between the plurality of insulating layers. It is formed through another conductive layer formed simultaneously with the conductive layer.

Means 4.
In the liquid crystal display device according to the present invention, for example, on the premise of any one of means 1 to 3, the counter voltage signal line and the counter electrode are electrically connected at two or more locations. It is characterized by.

Means 5.
The liquid crystal display device according to the present invention includes, for example, a plurality of gate signal lines arranged side by side on the liquid crystal side surface of one of the substrates that are opposed to each other through the liquid crystal, and intersecting these gate signal lines. A region surrounded by a plurality of drain signal lines arranged in parallel is a pixel region,
In each of these pixel regions, a switching element operated by a scanning signal from a gate signal line, a pixel electrode to which a video signal from a drain signal line is supplied via this switching element, and the above-described voltage via a counter voltage signal line A counter electrode to which a reference signal is supplied with respect to the video signal is formed,
The counter electrode is formed in a lower layer of a stack of a plurality of insulating layers, and the pixel electrode is formed between two insulating layers of the plurality of insulating layers of the stack in the extending direction of the drain signal line. A plurality of electrode groups extending along the direction intersecting the direction,
The counter voltage signal line is made of a non-translucent conductor, and is formed in an upper layer of the stacked body of the plurality of insulating layers, forming a lattice pattern covering the gate signal line and the drain signal line, A part thereof is electrically connected to the counter electrode through a through hole formed in the laminate of the plurality of insulating layers.

Means 6.
The liquid crystal display device according to the present invention, for example, is arranged adjacent to the counter voltage signal line formed by covering the drain signal line when the pixel region is viewed in plan on the premise of the configuration of the means 5. The distance between the pixel electrodes is set larger than the distance between the pixel electrodes arranged adjacent to each other.

Mean 7
The liquid crystal display device according to the present invention includes, for example, the counter voltage signal line formed by covering the drain signal line when the pixel region is viewed in plan on the premise of the configuration of any one of the means 5 and 6. The distance between the pixel electrode arranged adjacent to the pixel electrode is set larger than the distance between the counter voltage signal line and the counter electrode arranged adjacent to the counter voltage signal line. is there.

Means 8.
The liquid crystal display device according to the present invention includes, for example, a plurality of gate signal lines arranged side by side on the liquid crystal side surface of one of the substrates that are opposed to each other through the liquid crystal, and intersecting these gate signal lines. A region surrounded by a plurality of drain signal lines arranged in parallel is a pixel region,
In each of these pixel regions, a switching element operated by a scanning signal from a gate signal line, a pixel electrode to which a video signal from a drain signal line is supplied via this switching element, and the above-described voltage via a counter voltage signal line A counter electrode to which a reference signal is supplied with respect to the video signal is formed,
The counter voltage signal line is composed of anodized Al or an alloy thereof and is formed in a lower layer of a laminate of a plurality of insulating layers,
The counter electrode is made of a light-transmitting conductor, and is formed in an upper layer of the stacked body of the plurality of insulating layers, and covers the gate signal line and the drain signal line to form a lattice pattern, and a part thereof The capacitor is capacitively coupled to the counter voltage signal line through through holes formed in the laminate of the plurality of insulating layers.

Means 9.
The liquid crystal display device according to the present invention includes, for example, a plurality of gate signal lines arranged side by side on the liquid crystal side surface of one of the substrates that are opposed to each other through the liquid crystal, and intersecting these gate signal lines. A region surrounded by a plurality of drain signal lines arranged in parallel is a pixel region,
In each of these pixel regions, a switching element operated by a scanning signal from a gate signal line, a pixel electrode to which a video signal from a drain signal line is supplied via this switching element, and the above-described voltage via a counter voltage signal line A counter electrode to which a reference signal is supplied with respect to the video signal is formed,
The counter voltage signal line is composed of anodized Al or an alloy thereof and is formed in a lower layer of a laminate of a plurality of insulating layers, and the counter voltage signal line is formed in at least a part of the lower layer of the counter voltage signal line. A conductive material layer exposed from the counter voltage signal line;
The counter electrode is formed in an upper layer of the stacked body of the plurality of insulating layers, covers the gate signal line and the drain signal line to form a lattice pattern, and a stacked body of the plurality of insulating layers in a part thereof It is electrically connected to the conductive material layer through a through-hole formed in.

Means 10.
The liquid crystal display device according to the present invention is characterized in that, for example, on the premise of the configuration of the means 9, the counter electrode is composed of a translucent conductive layer.

Means 11.
In the liquid crystal display device according to the present invention, for example, a drain signal line is formed between two insulating layers of the laminate of a plurality of insulating layers on the premise of any one of the means 9 and 10, and the counter electrode The same material layer as that of the drain signal line is interposed between the conductive material layer and the conductive material layer.

  In addition, this invention is not limited to the above structure, A various change is possible in the range which does not deviate from the technical idea of this invention.

  As is apparent from the above description, according to the liquid crystal display device of the present invention, the aperture ratio of the pixel region can be improved. In addition, a reliable connection between the counter electrode and the counter voltage signal line can be achieved.

Hereinafter, embodiments of a liquid crystal display device according to the present invention will be described with reference to the drawings.
Example 1.
"overall structure"
FIG. 2 is an overall configuration diagram showing an embodiment of a liquid crystal display device according to the present invention. Although this figure is an equivalent circuit diagram, it is drawn corresponding to the actual geometric arrangement.

  In the figure, there is a pair of transparent substrates SUB1 and SUB2 arranged to face each other via a liquid crystal, and the liquid crystal is sealed by a sealing material SL that also serves to fix the other transparent substrate SUB2 to one transparent substrate SUB1.

  On the liquid crystal side surface of the one transparent substrate SUB1 surrounded by the sealing material SL, the gate signal lines GL extending in the x direction and arranged in parallel in the y direction, and extending in the y direction and aligned in the x direction. A drain signal line DL is provided.

  A region surrounded by each gate signal line GL and each drain signal line DL constitutes a pixel region, and a matrix aggregate of these pixel regions constitutes a liquid crystal display unit AR.

  A common counter voltage signal line CL that runs in each pixel region is formed in each pixel region arranged in parallel in the x direction. The counter voltage signal line CL serves as a signal line for supplying a reference voltage for a video signal to a counter electrode CT (described later) in each pixel region.

  In each pixel region, a thin film transistor TFT operated by a scanning signal from one side gate signal line GL and a pixel electrode PX to which a video signal from one side drain signal line DL is supplied via the thin film transistor TFT are formed. Has been.

  The pixel electrode PX generates an electric field with the counter electrode CT connected to the counter voltage signal line CL, and the light transmittance of the liquid crystal is controlled by the electric field.

  One end of each of the gate signal lines GL extends beyond the sealing material SL, and the extending end constitutes a terminal to which the output terminal of the vertical scanning drive circuit V is connected. The input terminal of the vertical scanning drive circuit V receives a signal from a printed circuit board disposed outside the liquid crystal display panel.

  The vertical scanning drive circuit V is composed of a plurality of semiconductor devices, and a plurality of adjacent gate signal lines GL are grouped, and one semiconductor device is assigned to each group.

  Similarly, one end of each of the drain signal lines DL extends beyond the seal material SL, and the extending end constitutes a terminal to which the output terminal of the video signal driving circuit He is connected. . The input terminal of the video signal driving circuit He is adapted to receive a signal from a printed circuit board arranged outside the liquid crystal display panel.

  The video signal drive circuit He is also composed of a plurality of semiconductor devices, and a plurality of adjacent drain signal lines DL are grouped, and one semiconductor device is assigned to each group. .

  The counter voltage signal lines CL are connected in common at the end on the right side in the figure, and the connection line extends beyond the seal material SL, and constitutes a terminal CLT at the extended end. A voltage serving as a reference for the video signal is supplied from the terminal CLT.

  One of the gate signal lines GL is sequentially selected by a scanning signal from the vertical scanning circuit V.

  In addition, a video signal is supplied to each of the drain signal lines DL by the video signal driving circuit He in accordance with the selection timing of the gate signal line GL.

  In the above-described embodiment, the vertical scanning drive circuit V and the video signal drive circuit He indicate the semiconductor device mounted on the transparent substrate SUB1, but for example, straddle between the transparent substrate SUB1 and the printed circuit board. It may be a so-called tape carrier type semiconductor device to be connected. Further, when the semiconductor layer of the thin film transistor TFT is made of polycrystalline silicon (p-Si), the transparent substrate SUB1 is made of the polycrystalline silicon. A semiconductor element may be formed together with a wiring layer.

<Pixel configuration>
FIG. 1A is a plan view showing a configuration of an embodiment of the pixel region. 1B is a cross-sectional view taken along line bb in FIG. 1A, FIG. 1C is a cross-sectional view taken along line cc in FIG. 1A, and FIG. It is sectional drawing in the dd line | wire of (a).

  In each drawing, a pair of gate signal lines GL extending in the x direction and arranged in parallel in the y direction are first formed on the liquid crystal side surface of the transparent substrate SUB1.

  These gate signal lines GL surround a rectangular region together with a pair of drain signal lines DL described later, and this region is configured as a pixel region.

A counter electrode CT made of a translucent conductive material is formed on the surface of the transparent substrate SUB1 in the pixel region at the center except for a slight region around the pixel region. As the translucent conductive material, for example, ITO (Indium Tin Oxide), ITZO (Indium Tin Zinc Oxide), IZO (Indium Zinc Oxide), SnO ₂ , In ₂ O ₃ or the like is used.

  Thus, on the surface of the transparent substrate SUB1 on which the gate signal line GL and the counter electrode CT are formed, an insulating film GI made of, for example, SiN is formed so as to cover the gate signal line GL and the like.

  The insulating film GI functions as an interlayer insulating film for the gate signal line GL in a region where a drain signal line DL described later is formed, and functions as a gate insulating film in a region where a thin film transistor TFT described later is formed. It has become.

  A semiconductor layer AS made of, for example, amorphous Si is formed on the surface of the insulating film GI so as to overlap a part of the gate signal line GL.

  This semiconductor layer AS is that of the thin film transistor TFT, and by forming the drain electrode SD1 and the source electrode SD2 on the upper surface thereof, an MIS type transistor having an inverted stagger structure having a part of the gate signal line as the gate electrode is formed. be able to.

  Here, the drain electrode SD1 and the source electrode SD2 are formed simultaneously with the formation of the drain signal line DL.

  That is, a drain signal line DL extending in the y direction and juxtaposed in the x direction is formed, and a part of the drain signal line DL is extended to the upper surface of the semiconductor layer AS to form the drain electrode SD1. A source electrode SD2 is formed by being separated from the electrode SD1 by the channel length of the thin film transistor TFT.

  Further, the source electrode SD2 is slightly extended to the pixel region side to form a contact portion COT for electrical connection with a pixel electrode PX described later.

  A protective film PSV1 is formed on the surface of the transparent substrate SUB1 so as to cover the drain signal line DL, the drain electrode SD1, and the source electrode SD2. This protective film PSV1 is made of an inorganic material layer such as a SiN film, for example, and avoids direct contact with the liquid crystal of the thin film transistor TFT together with the protective film PSV2 described later. This is to prevent the characteristics from changing due to the contact of the thin film transistor TFT with the liquid crystal.

On the surface of the protective film PSV1, pixel electrodes PX made of, for example, a translucent conductive material are formed. As the translucent conductive material, for example, ITO (Indium Tin Oxide), ITZO (Indium Tin Zinc Oxide), IZO (Indium Zinc Oxide), SnO ₂ , In ₂ O ₃ or the like is used.

  Here, the pixel electrode PX is composed of a number of strip-shaped electrode groups extending in the x direction and arranged in parallel in the y direction in the figure, but each electrode is in a substantially central portion in the extending direction. It is formed with a mountain-shaped pattern having a bent portion.

  Such a pixel electrode PX generates an electric field between the pixel electrode PX and the counter electrode CT, particularly at its edge (edge). By adopting the above-mentioned pattern, a so-called multi-domain method is adopted. It has become the composition.

  In other words, even when the molecular arrangement of the liquid crystal is the same, the polarization state of the transmitted light changes depending on the incident direction of the light incident on the liquid crystal display panel, so that the light transmittance varies depending on the incident direction.

  The viewing angle dependency of such a liquid crystal display panel has a display characteristic that when the viewpoint is tilted with respect to the viewing angle direction, a luminance reversal phenomenon is caused, and an image is colored in the case of color display.

  Therefore, the pixel electrode PX has a pattern in which at least one bent portion is formed in the extending direction, and the counter electrode CT is formed in a shape in which this pattern is shifted in parallel, and the bent points of these electrodes are connected. The direction of the electric field acting between the electrodes is made different between one region and the other region with the virtual line as a boundary, thereby compensating for the coloring of the image depending on the viewing angle.

  In this embodiment, the counter electrode CT is formed over almost the entire pixel region, but the portion that actually functions as the counter electrode is a portion obtained by shifting the pixel electrode PX in parallel as described above. .

  The electrode groups of the pixel electrodes PX are integrally formed of the same material in the periphery so that they are electrically connected to each other. Therefore, the pixel electrode PX as a whole is a multiplicity of slits (mountain-shaped slits) extending in the x direction and juxtaposed in the y direction on a conductive layer formed in the central portion excluding a small area around the pixel area. Is formed as a pattern.

  A part of the pixel electrode PX having such a pattern is electrically connected to the contact portion COT of the source electrode SD2 of the thin film transistor TFT through a through hole previously formed in the protective film PSV1.

  Further, a protective film PSV2 is formed on the surface of the transparent substrate SUB1 so as to cover the pixel electrode PX. This protective film PSV2 is made of an organic material made of resin, for example.

  As described above, this protective film PSV2 functions as a protective film PSV that avoids direct contact with the liquid crystal of the thin film transistor TFT together with the protective film PSV1, but the surface is flattened by using an organic material as the material. In addition, the rubbing property of the alignment film formed on the upper surface can be improved.

  Further, a counter voltage signal line CL for supplying a signal to the counter electrode CT is formed on the surface of the protective film PSV2.

  For the counter voltage signal line CL, a material having a small electric resistance is selected, and therefore metal or the like is used.

  Further, the counter voltage signal line CL has a lattice pattern that covers the drain signal line DL and the gate signal line GL, and the opening is a central portion excluding a slight portion around the pixel region, that is, substantially It is formed so that a typical pixel region is exposed.

  The counter voltage signal line CL formed in such a pattern can supply a counter voltage signal from any location and a plurality of locations around the liquid crystal display AR. For this reason, the waveform distortion of the counter voltage signal in the counter voltage signal line CL can be eliminated, and the occurrence of smear and luminance gradient can be reduced.

  Further, since the electrical resistance and the feeding resistance can be reduced as a whole of the counter voltage signal line CL, the lateral smear can be reduced to 1/3 or less in so-called common inversion driving.

  The counter voltage signal line CL that covers the drain signal line DL along the longitudinal direction thereof is formed to have a width larger than that of the drain signal line DL so that the central axes thereof are substantially aligned. Thus, the electric field that causes noise from the drain signal line DL is terminated on the counter voltage signal line CL side, and is difficult to terminate on the pixel electrode PX.

  In this case, the parasitic capacitance between the drain signal line DL and the counter voltage signal line CL is greatly reduced by the protective film PSV2 made of an organic material interposed therebetween. This is because such a protective film PSV2 has a small dielectric constant.

  Similarly, the counter voltage signal line CL covering the drain signal line DL along the longitudinal direction thereof is formed to have a width larger than that of the drain signal line DL so that the central axes thereof are substantially aligned.

  In this case, the counter voltage signal line CL is formed to cover the thin film transistor TFT. This is because the counter voltage signal line CL is formed of a non-translucent metal and can shield extraneous light applied to the thin film transistor TFT, thereby preventing characteristic deterioration of the thin film transistor TFT.

  The counter electrode signal line CL has a region overlapping with a part of the pixel electrode PX in the pixel region. In this region, the capacitor element Cstg having the protective film PSV2 as a dielectric film is formed. ing.

  The capacitive element Cstg has a function of, for example, accumulating a video signal supplied to the pixel electrode PX for a relatively long time.

  An alignment film (not shown) is formed on the upper surface of the transparent substrate SUB1 on which the counter electrode CT is formed in such a manner so as to cover the counter electrode CT. This alignment film is in direct contact with the liquid crystal, and the initial alignment direction of the molecules of the liquid crystal is determined by rubbing formed on the surface thereof.

  A color filter is formed on the liquid crystal side surface of the transparent substrate SUB1 and the transparent substrate SUB2 disposed via the liquid crystal. This color filter is made up of, for example, red (R), green (G), and blue (B) filters. For example, a red filter is commonly formed in each pixel region group arranged in the y direction. It is formed in an arrangement such as red (R) color, green (G) color, blue (B) color, red (R) color,... Common to pixel region groups that are sequentially adjacent to the region group in the x direction. Yes.

  A flattening film is formed on the surface of the transparent substrate on which the color filters are formed so as to cover these color filters. This flattening film is made of a resin film that can be formed by coating, and is provided to eliminate a step that becomes obvious due to the formation of the color filter.

  An alignment film is formed on the surface of the flattening film, and the alignment film is a film in direct contact with the liquid crystal, and the initial alignment direction of the molecules of the liquid crystal is determined by rubbing formed on the surface. ing.

  In this embodiment, the black matrix is not formed on the liquid crystal side surface of the transparent substrate SUB2. This is because the counter voltage signal line CL formed on the surface of the transparent substrate SUB1 on the liquid crystal side has the same function as the black matrix. Thereby, the precision of alignment of the transparent substrate SUB2 with respect to the transparent substrate SUB1 can be improved.

Example 2
FIG. 3 is a block diagram showing another embodiment of the liquid crystal display device according to the present invention and corresponds to FIG.

  1B is different from the case of FIG. 1B in that the counter electrode CT and the counter voltage signal line CL are connected through the through hole TH, and the same conductive layer CNL as the material layer forming the pixel electrode PX is interposed. It is in letting it be.

  That is, when the pixel electrode PX is formed on the upper surface of the protective film PSV1, a conductive layer connected to the counter electrode CT is simultaneously formed through the through hole TH1 formed in the protective film PSV1, and then the upper surface of the protective film PSV2 is formed. The counter voltage signal line CL formed in (1) is connected to the conductive layer through a through hole TH2 formed in the protective film PSV2.

  In this case, the contact area of the connection portion between the counter electrode CT and the counter voltage signal line CL can be increased, and the connection can be made reliable.

Example 3
FIG. 4 is a block diagram showing another embodiment of the liquid crystal display device according to the present invention and corresponds to FIG.

  3 differs from the case of FIG. 3 in that the conductive layer CNL, which is the same as the material layer constituting the drain signal line DL, is interposed in the connection between the counter electrode CT and the counter voltage signal line CL through the through hole TH. There is to be.

  When a translucent conductive material is used as the counter electrode CT and, for example, Al or an alloy thereof is used as the counter voltage signal line CL, their connection resistance increases. Therefore, as the drain signal line DL, for example, Cr, By using Mo, W, another refractory metal, an alloy containing these, or the like, and having the above-described configuration, it is possible to reduce the connection resistance between the counter electrode CT and the counter voltage signal line CL. .

Example 4
FIG. 5 is a block diagram showing another embodiment of the liquid crystal display device according to the present invention and corresponds to FIG.

  3 differs from the case of FIG. 3 in that the through hole TH1 formed in the protective film PSV1 and the insulating film GI and the through hole TH2 formed in the insulating film PSV2 are different from each other without matching their central axes. There is in forming.

  In such a case, the surface of the protective film PSV2 made of an organic material is flattened even at the positions where the protective film PSV1 and the through hole TH1 of the insulating film GI are formed.

  This is because the concave portion formed in the protective film PSV2 is only the through hole TH2, but the depth is relatively shallow, so that the rubbing property of the alignment film formed on the surface of the protective film PSV2 is improved. be able to.

Example 5 FIG.
FIG. 6 is a block diagram showing another embodiment of the liquid crystal display device according to the present invention and corresponds to FIG.

  A configuration different from the case of FIG. 1A is that not only one part but also two parts are provided to connect the counter electrode CT and the counter voltage signal line CL.

  As is clear from the above-described configuration, the connection between the counter electrode CT and the counter voltage signal line CL must be made through a through hole TH formed in a laminate having a relatively multilayer structure of the protective films PSV2, PSV1, and the insulating film GI. Therefore, a redundant configuration is provided to avoid the occurrence of connection failure.

  One through hole is formed close to one gate signal line GL surrounding the pixel region, and the other through hole is formed close to the other gate signal line GL.

Example 6
FIG. 7A is a plan view showing another embodiment of the liquid crystal display device according to the present invention and corresponds to FIG. Moreover, FIG.7 (b) has shown sectional drawing in the bb line of Fig.7 (a).

  The pixel electrode PX has a different configuration compared to the case of FIG. 1A, and the pixel electrode PX is composed of an electrode group extending substantially linearly in the y direction and arranged in parallel in the x direction. It is in.

  Also in this case, the pixel electrodes PX formed of the electrode group are connected to each other at the upper and lower ends.

  A protective film PSV2 is formed so as to cover the pixel electrodes PX, and a counter voltage signal line CL formed so as to cover the drain signal line DL and the gate signal line GL is formed on the upper surface of the protective film PSV2.

  When configured in this manner, the pixel region adjacent to the drain signal line DL among the pixel electrodes PX formed in the region of the opening of the counter voltage signal line CL is disposed closer to the counter voltage signal line CL. In addition, the counter voltage signal line CL can have the function of the counter electrode CT to generate an electric field therebetween.

  Therefore, a pixel region can be formed without forming a useless region in the region of the opening of the counter voltage signal line CL, and the aperture ratio can be improved.

  That is, the electric field from the drain signal line DL is terminated almost intensively on the side of the counter voltage signal line DL formed on the upper side, and the amount of radial expansion on both sides of the counter voltage signal line CL is reduced. Become. For this reason, it can be configured as a pixel region that can contribute to display even in the vicinity of the counter voltage signal line CL.

  Further, by adopting the above-described configuration, as shown in FIG. 8 corresponding to FIG. 7B, the distance W1 between the counter voltage signal line CL and the pixel electrode PX adjacent thereto is set to each pixel electrode PX. It becomes possible to set different values for the distance W2. This is because, for example, when the number of pixel electrodes PX is already determined and the distance between the pixel regions is set to be variable, the distance between the counter voltage signal line CL and the pixel electrode PX adjacent thereto is set. By adjusting W1, an optimal pixel configuration can be easily realized.

  Further, since the counter voltage signal line CL is formed on the upper surface of the protective film PSV2 having a small dielectric constant, the electric field strength between the counter voltage signal line CL and the pixel electrode PX adjacent thereto is equal to the counter electrode CT and the pixel. It becomes larger than the intensity of the electric field between the electrodes PX. For this reason, W1> W2 is desirable in order to make the luminance uniform in the pixel, and when the film thickness of the protective film PSV2 is d, it is preferable to satisfy W1> W2 + d.

  Further, in order to further reduce the noise from the drain signal line DL, it is desirable to set W1> W3 as shown in FIG. Here, W3 is a separation distance from the counter electrode CT arranged close to the counter voltage signal line CL. With this configuration, the noise electric field from the drain signal line DL is confined to the equipotential surface formed by the counter voltage signal line CL and the counter electrode CT having the same potential, and leakage of the noise electric field to the outside is suppressed. This is because that.

  Here, the counter voltage signal line CL is preferably formed so that the sides parallel to the running direction with respect to the drain signal line DL protrude beyond 1/3 × W1.

  In the above-described embodiment, it is needless to say that the multi-domain method may be adopted by providing each pixel electrode PX with one or a plurality of bent portions in the longitudinal direction. In this case, if the drain signal line DL and the counter voltage signal line CL are also formed into a pattern having a bent portion such that the pixel electrode PX is shifted in the x direction, the above-described effects can be obtained.

Example 7
FIG. 9A is a plan view showing another embodiment of the liquid crystal display device according to the present invention and corresponds to FIG. 7A. FIG. 9B is a cross-sectional view taken along the line bb in FIG. 9A.

  In the configuration different from that in FIG. 7A, first, the pixel electrode PX is formed in the same layer as the drain signal line DL on the insulating film GI.

  Then, a protective film PSV1 and a protective film PSV2 are sequentially formed so as to cover the pixel electrode PX and the drain signal line DL, and a lattice pattern is formed so as to cover the drain signal line DL and the gate signal line GL on the upper surface of the protective film PSV2. Counter electrode CT is formed.

  Further, the counter electrode CT is electrically connected to a counter voltage signal line CL formed as a lower layer of the insulating film GI through a through hole TH formed through the protective film PSV2, the protective film PSV1, and the insulating film GI. ing.

  Note that the pixel electrode PX and the counter electrode CT (drain signal line DL) are formed with a plurality of bent portions along the traveling direction, and a multi-domain method is adopted.

  In this case, the counter voltage signal line CL is formed at the same time when the gate signal line GL is formed. The counter voltage signal line CL is made of, for example, Al or an alloy layer thereof, and an anodized oxide film AO is formed on the surface thereof. Conceivable.

  In this embodiment, a through hole TH is formed in the protective film PSV2, the protective film PSV1, and the insulating film GI so as to expose a part of the anodized counter voltage signal line CL, and this through hole TH is covered. Thus, the counter electrode CT is formed.

  That is, the electrical connection between the counter electrode CT and the counter voltage signal line CL is made by capacitive coupling through the oxide film AO, whereby the oxide film AO is not particularly removed from the connection portion. .

  Since the counter electrode CT has a grid pattern, power can be supplied from the counter electrode CT, and the counter voltage signal line CL has a role of stabilizing a so-called common potential without direct power supply. Have.

  Therefore, in another embodiment, as shown in FIG. 10, the same conductive layer CNL as the drain signal line DL is further provided between the anodized counter voltage signal line CL and the counter electrode CT. Of course, it may be made to intervene.

  When such a capacitive coupling configuration is performed, the counter voltage signal line CL and the counter electrode CT may be made of different materials. This is because a direct electrical connection can be achieved even if a stress is generated between them and a crack occurs at the joint.

Example 8 FIG.
FIG. 11A is a plan view showing another embodiment of the liquid crystal display device according to the present invention and corresponds to FIG. 9A. Moreover, FIG.11 (b) has shown sectional drawing in the bb line of Fig.11 (a).

  Compared to the case of FIG. 9A, the counter voltage signal line CL is made of Al (or Mo, Ti, Ta, W, Zr, Si, or an alloy of one or more of these), and on the surface thereof The oxide film AO is formed by anodization in the same manner, but other conductive layers (for example, Cr, Mo, W, Ti, Zr or one or more of them) other than Al or an alloy thereof are partially formed in the lower layer. A plurality of alloys) CNL is formed and extended to a region other than the region where the counter voltage signal line CL is formed.

  The extending portion of the conductive layer CNL functions as a contact portion with the counter electrode CT. This is because even if the counter voltage signal line CL is anodized, the metal layer is not anodized, and a terminal portion that can be sufficiently electrically connected to the counter voltage signal line CL can be formed.

  Needless to say, the conductive layer CNL may be formed in the entire region where the counter voltage signal line CL is formed, except for the extended portion. In other words, the conductive layer CNL may be formed as a pattern having the same pattern as the counter voltage signal line CL and a part of which is extended.

  FIG. 12 is a sectional view showing another embodiment of the liquid crystal display device according to the present invention and corresponds to FIG.

  The conductive layer CNL and the counter electrode CT are connected via the same conductive layer CNL2 as the material layer of the drain signal line DL.

  In this case, the contact area between the metal layer and the counter electrode CT can be increased, and the connection reliability can be improved.

Example 9
As another example of the configuration shown in Example 8, the metal layer may be replaced with a light-transmitting conductive layer such as ITO or IZO.

  In this case, since the counter electrode CT is also a light-transmitting conductive layer, the aperture ratio of the pixel region is not reduced even if the area is increased in the connection portion. Play.

Example 10
FIG. 13A is a sectional view showing another embodiment of the liquid crystal display device according to the present invention and corresponds to FIG. 11A. FIG.13 (b) is sectional drawing in the bb line of Fig.13 (a).

  11A is different from the case of FIG. 11A in that an oxide film AO formed on the surface of the counter voltage signal line CL is formed at the electrical connection portion between the counter electrode CT and the counter voltage signal line CL. It is configured such that it is not partially formed during anodization.

  That is, the transparent substrate SUB1 on which the counter voltage signal line CL is formed is immersed in the electric field solution, the counter voltage signal line CL is set as one electrode, and another electrode plate immersed in the electric field solution is set as the other electrode plate. By applying a voltage as an electrode (anodization), an anodic oxide film is formed on the surface of the counter voltage signal line CL.

  In this case, anodization is performed in a state where the resist film is selectively formed at the connection portion of the counter voltage signal line CL with the counter electrode CT. By removing the resist film at the stage where the anodization is completed, it is possible to obtain the counter voltage signal line CL in which the surface of Al or its alloy is exposed.

  The resist is formed by a normal exposure process in which a photoresist is formed on the entire surface, then exposed by mask exposure, and unnecessary resist is removed.

  In this case, it is desirable that the counter electrode CT be formed not only on the oxide film AO removal portion on the counter voltage signal line CL but also on the oxide film AO formation region around it.

  Otherwise, unformed Al or an alloy thereof is directly opposed to the insulating film GI, and so-called hillock may be generated.

Example 11
FIG. 14 is a sectional view showing another embodiment of the liquid crystal display device according to the present invention and corresponds to FIG.

  The configuration different from the case of FIG. 13B is the same conductive layer CNL as the material of the drain signal line DL formed on the insulating film GI in the connection between the counter electrode CT and the counter voltage signal line CL. This is because of interposing.

  In this case, direct connection between Al of the counter voltage signal line CL or an alloy thereof and a light-transmitting conductive layer such as ITO can be avoided, and an increase in connection resistance can be suppressed. This is because, since the light-transmitting conductive layer is an oxide, when it is brought into direct contact with Al or an alloy thereof, the Al or the alloy thereof is oxidized, resulting in an increase in connection resistance.

Example 12
FIGS. 15A to 15C are explanatory views showing another embodiment of the liquid crystal display device according to the present invention.

  Each figure shows the connection between the counter voltage signal line CL and the counter electrode CT, for example, for each pixel in FIG. 15A, and for each pixel in a plurality of adjacent pixels in FIG. In (c), three pixels for color display are provided for each pixel.

  As described above, the counter voltage signal line CL or the counter electrode CT has a lattice pattern that defines each pixel region. Therefore, the connection is arbitrary in terms of location and number. Can be set as things.

  However, by positioning the connection between the counter voltage signal line CL and the counter electrode CT in a pixel having a relatively high luminance, the influence on the luminance can be prevented.

  In the case where a so-called columnar spacer formed on one of the substrates is provided between the transparent substrate SUB1 and the transparent substrate SUB2, the pixel region in which the spacer is formed, the counter voltage signal line CL, and the counter electrode CT The pixel region to be connected may be separated.

  In this case, the three-dimensional structure of the elementary region can be suppressed from becoming relatively complicated compared to other pixels, and the anxiety that an unexpected defect due to the difference in the three-dimensional structure occurs only in the specific pixel can be avoided in advance. .

It is a block diagram which shows one Example of the pixel of the liquid crystal display device by this invention. It is a block diagram which shows one Example of the liquid crystal display device by this invention. It is sectional drawing which shows the other Example of the pixel of the liquid crystal display device by this invention. It is sectional drawing which shows the other Example of the pixel of the liquid crystal display device by this invention. It is sectional drawing which shows the other Example of the pixel of the liquid crystal display device by this invention. It is a top view which shows the other Example of the pixel of the liquid crystal display device by this invention. It is a block diagram which shows the other Example of the pixel of the liquid crystal display device by this invention. It is sectional drawing which shows the other Example of the pixel of the liquid crystal display device by this invention. It is a block diagram which shows the other Example of the pixel of the liquid crystal display device by this invention. It is sectional drawing which shows the other Example of the pixel of the liquid crystal display device by this invention. It is a block diagram which shows the other Example of the pixel of the liquid crystal display device by this invention. It is sectional drawing which shows the other Example of the pixel of the liquid crystal display device by this invention. It is a block diagram which shows the other Example of the pixel of the liquid crystal display device by this invention. It is sectional drawing which shows the other Example of the pixel of the liquid crystal display device by this invention. It is explanatory drawing which shows the other Example of the pixel of the liquid crystal display device by this invention.

Explanation of symbols

SUB1 ... transparent substrate, GL ... gate signal line, DL ... drain signal line, CL ... counter voltage signal line, TFT ... thin film transistor, Cstg ... capacitor element, PX ... pixel electrode, CT ... counter electrode, CNL ... conductive layer, GI ... Insulating film (gate insulating film), PSV1 ... protective film (inorganic material), PSV2 ... protective film (organic material).

Claims (4)

A plurality of gate signal lines juxtaposed on the liquid crystal side surface of one of the substrates opposed to each other through the liquid crystal, and a plurality of drain signal lines juxtaposed across the gate signal lines The area surrounded by
In each of these pixel regions, a switching element operated by a scanning signal from a gate signal line, a pixel electrode to which a video signal from a drain signal line is supplied via this switching element, and the above-described voltage via a counter voltage signal line A counter electrode to which a reference signal is supplied with respect to the video signal is formed,
The counter voltage signal line is composed of anodized Al or an alloy thereof and is formed in a lower layer of a laminate of a plurality of insulating layers,
The counter electrode is made of a light-transmitting conductor, and is formed in an upper layer of the stacked body of the plurality of insulating layers, and covers the gate signal line and the drain signal line to form a lattice pattern, and a part thereof A liquid crystal display device, wherein the liquid crystal display device is capacitively coupled to the counter voltage signal line through a through-hole formed in the laminate of the plurality of insulating layers. A plurality of gate signal lines juxtaposed on the liquid crystal side surface of one of the substrates opposed to each other through the liquid crystal, and a plurality of drain signal lines juxtaposed across the gate signal lines The area surrounded by
In each of these pixel regions, a switching element operated by a scanning signal from a gate signal line, a pixel electrode to which a video signal from a drain signal line is supplied via this switching element, and the above-described voltage via a counter voltage signal line A counter electrode to which a reference signal is supplied with respect to the video signal is formed,
The counter voltage signal line is composed of anodized Al or an alloy thereof and is formed in a lower layer of a laminate of a plurality of insulating layers, and the counter voltage signal line is formed in at least a part of the lower layer of the counter voltage signal line. A conductive material layer exposed from the counter voltage signal line;
The counter electrode is formed in an upper layer of the stacked body of the plurality of insulating layers, covers the gate signal line and the drain signal line to form a lattice pattern, and a stacked body of the plurality of insulating layers in a part thereof A liquid crystal display device, wherein the liquid crystal display device is electrically connected to the conductive material layer through a through-hole formed in the substrate. The liquid crystal display device according to claim 2, wherein the counter electrode is formed of a light-transmitting conductive layer. A drain signal line is formed between two insulating layers of the laminate of a plurality of insulating layers, and the same material layer as the material of the drain signal line is interposed between the counter electrode and the conductive material layer. The liquid crystal display device according to claim 2, wherein the liquid crystal display device is a liquid crystal display device.

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