JP2004004851A - Electro-optical device and electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal device capable of keeping an opposing electrode uniformly at a constant potential and displaying pictures with high visibility by preventing flickering, and to provide an electronic apparatus equipped with the same. <P>SOLUTION: This liquid crystal display is equipped with: an opposing electrode potential line 113 formed on a TFT array substrate 1 at least along the contour of the opposing electrode and receiving a potential signal LCCOM from the outside for keeping the opposing electrode at a prescribed potential set in advance; and a vertical conduction terminal 107 for providing the potential signal LCCOM to the opposing electrode supplied by connecting the opposing electrode potential line 113 to the opposing electrode at least at four corners of the opposing electrode. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention belongs to a technical field of an electro-optical device such as a liquid crystal device of an active matrix driving method by driving a thin film transistor (hereinafter, referred to as a TFT) and an electronic device using the same. In particular, a peripheral circuit such as a sampling circuit includes a TFT array. The invention belongs to the technical field of an electro-optical device having a configuration formed on a substrate and an electronic apparatus using the same.
[0002]
[Prior art]
Conventionally, in a liquid crystal device, in order to apply a predetermined electric field to a liquid crystal layer, a common electrode is generally arranged so as to face each pixel electrode in the TFT array substrate and sandwich the liquid crystal layer. is there. Then, the counter electrode is formed in all the regions facing the region including all the pixel electrodes (hereinafter, this region is referred to as an image display region) with a liquid crystal layer interposed therebetween, and further in the image display region. In many cases, the opposing electrode is formed by one electrode layer over the entire opposing area.
[0003]
When the liquid crystal is driven, the counter electrode is kept at a constant potential, and the application / non-application of the image signal is controlled for each of the pixel electrodes facing the counter electrode to display an image.
[0004]
Here, when the counter electrode has a constant potential, a counter electrode potential line for transmitting a potential signal for applying the constant potential is provided on the TFT array substrate on which the pixel electrode is formed, The potential signal is supplied to the counter electrode by conducting the counter electrode and the counter electrode potential line at any position on the TFT array substrate. When conducting between the counter electrode and the counter electrode potential line, a configuration is generally used in which the counter electrode and the counter electrode potential line are connected at one or two positions on the counter electrode.
[0005]
[Problems to be solved by the invention]
However, according to the above-described method of conducting between the counter electrode and the counter electrode potential line, there is only one or two positions on the counter electrode, and the entire counter electrode cannot be kept at a constant potential. There was a point.
[0006]
That is, as described above, the counter electrode itself needs to be transparent in order to be disposed in the entire area facing the image display area as described above. As such a transparent electrode, a transparent electrode formed of a material called ITO (Indium-Tin Oxide) has been most commonly used, but the ITO has a feature of high sheet resistance. It has.
[0007]
Therefore, if a configuration is used in which a potential signal is supplied to the counter electrode from only the two locations described above, the resistance of each counter electrode portion increases due to the height of the sheet resistance, and as a result, the entire counter electrode becomes uniform. May not be at a high potential.
[0008]
In recent years, in recent years, the miniaturization of liquid crystal devices has progressed, and the so-called storage capacitance for keeping the pixel electrode at a predetermined potential tends to decrease even after the TFT that supplies an image signal to the pixel electrode is turned off. However, in this case, if the counter electrode does not have a uniform potential due to the above-described cause, there is a problem that flicker (so-called flicker) occurs in the entire image.
[0009]
Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to display an image with high visibility by preventing the counter electrode from being uniformly kept at a constant potential, preventing flicker. It is an object of the present invention to provide a liquid crystal device capable of performing the above and an electronic apparatus provided with the liquid crystal device.
[0010]
[Means for Solving the Problems]
In order to solve the above problems, the invention according to claim 1, wherein a plurality of data lines to which an image signal is supplied to the first substrate; a plurality of scanning lines to which a scanning signal is supplied; And an image display area including a switching element connected to a scanning line and a pixel electrode connected to the switching element; and an electro-optical device having a counter electrode on the second substrate. On one substrate, a conductive line for supplying a predetermined potential to the counter electrode is formed along the outer periphery of the image display region, and the conductive line and the counter electrode are formed outside the image display region. It is characterized by having a plurality of conducting means for conducting.
[0011]
According to the operation of the first aspect of the present invention, a predetermined potential is supplied to at least the counter electrode from the outside on the first substrate. Then, the plurality of conduction means supplies the potential supplied to the counter electrode by conducting the conductive line and the counter electrode outside the image display area. Therefore, since a predetermined potential is supplied to the counter electrode via the conductive line, even when the resistance of the counter electrode itself is high, the entire counter electrode can be set to a uniform potential by the plurality of conducting means.
[0012]
According to a second aspect of the present invention, in the electro-optical device according to the first aspect, an external input terminal such as a mounting terminal for externally supplying the potential to the conductive line is provided. , Are disposed at the start and end of the arranged conductive wires, respectively.
[0013]
According to the function of the invention described in claim 2, in addition to the function of the invention described in claim 1, the external input terminals are arranged at the start end and the end of the conductive line, respectively. A potential signal can be supplied, and a constant potential can be more uniformly set over the entire counter electrode.
[0014]
According to a third aspect of the present invention, there is provided an electro-optical device according to the first or second aspect, wherein an area surrounding the image display area on the first substrate and the second substrate is provided. A sealing means such as a sealing material for bonding the first substrate and the second substrate together, and an outline of the image display area on the second substrate in an area between the sealing means and the image display area. And a light-shielding peripheral parting formed along the line, wherein the conductive line is disposed in a region on the first substrate facing the peripheral parting.
[0015]
According to the operation of the invention described in claim 3, in addition to the operation of the invention described in claim 1 or 2, the sealing means is provided in the area surrounding the image display area on the first substrate and the second substrate. One substrate and the second substrate are attached to each other.
[0016]
On the other hand, the light-shielding peripheral parting is formed along the contour of the image display area on the second substrate in the area between the sealing means and the image display area.
[0017]
Then, the conductive line is provided in a region on the first substrate facing the peripheral parting.
[0018]
Therefore, since the conductive lines are provided on the first substrate facing the peripheral partition which is not normally used, the utilization efficiency of the area on the first substrate can be improved.
[0019]
According to a fourth aspect of the present invention, there is provided an electro-optical device according to any one of the first to third aspects, wherein the electro-optical device is adjacent to at least one side forming an outline of the image display area. A conductive layer having a planar lattice shape formed together with the conductive lines is disposed in a region outside the image display region. According to the operation of the invention described in claim 4, in addition to the operation of the invention described in any one of claims 1 to 3, the planar conductive layer forms a part of the conductive wire, Since the conductive layer has a lattice shape, the resistance of the conductive line itself can be reduced, and even if a part of the lattice shape is lost, the conductive line is not broken.
[0020]
According to a fifth aspect of the present invention, there is provided an electro-optical device according to the fourth aspect, wherein the electro-optical device is formed on a layer different from the conductive layer on the first substrate. It further includes a sub-conductive layer to be connected.
[0021]
According to the function of the invention described in claim 5, in addition to the function of the invention described in claim 4, the sub-conductive layer that is connected to the conductive layer by interlayer is formed on a layer different from the conductive layer on the first substrate. Therefore, even if the electrical connection cannot be established due to breakage or the like of the conductive layer, the potential signal can be transmitted as a conductive line with the sub-conductive layer.
[0022]
According to a sixth aspect of the present invention, there is provided the electro-optical device according to the first aspect, wherein the conductive line is any one of the data line or the scanning line. It is formed of the same material as the material forming one of them.
[0023]
According to the operation of the invention described in claim 6, in addition to the operation of the invention described in any one of claims 1 to 5, a material in which the conductive line forms one of a data line and a scanning line Therefore, the conductive line can be formed in the same step when forming either the data line or the scan line.
[0024]
According to a seventh aspect of the present invention, there is provided an electro-optical device according to any one of the first to sixth aspects.
[0025]
According to the operation of the invention described in claim 7, since the electro-optical device according to any one of claims 1 to 6 is provided in the electronic apparatus, an image with less flicker or the like can be displayed.
[0026]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, a preferred embodiment of the present invention will be described with reference to the drawings.
[0027]
Each of the embodiments described below is an embodiment in which the present invention is applied to a projection-type liquid crystal device that transmits light from a light source and displays an image.
[0028]
First, a first embodiment according to the present invention will be described with reference to FIGS.
(I) Configuration of liquid crystal device
First, the overall configuration of the liquid crystal device according to the embodiment will be described with reference to FIGS. Here, FIG. 1 is a block diagram showing a configuration of various wirings, peripheral circuits, and the like provided on a TFT array substrate in the liquid crystal device of the embodiment, and FIG. 2 shows a TFT array substrate formed thereon. FIG. 3 is a plan view of the components as viewed from the counter substrate side, and FIG. 3 is a cross-sectional view taken along the line HH ′ of FIG. 2 including the counter substrate.
[0029]
As shown in FIG. 1, the liquid crystal device 200 includes a TFT array substrate 1 as a first substrate made of, for example, a quartz substrate, hard glass, or the like. On the TFT array substrate 1, a plurality of pixel electrodes 11 provided in a matrix and a plurality of low-resistance metals such as aluminum or a metal such as metal silicide, each of which is arranged in the X direction and each extends in the Y direction. A plurality of data lines 35 formed of an alloy film or the like; a plurality of scanning lines 31 arranged in the Y direction, each of which is formed of a conductive material such as a polysilicon film extending in the X direction; A polysilicon layer or the like that intervenes between the data line 35 and the pixel electrode 11 and controls the conduction state and the non-conduction state between the data line 35 and the pixel electrode 11 using scanning signals supplied via the scanning lines 31, respectively. Are formed. Further, on the TFT array substrate 1, a capacitance line 31 ′, which is a wiring for a storage capacitor used for holding a potential in the pixel electrode 11, is formed substantially parallel to the scanning line 31. At this time, the capacitance lines 31 'are connected to a positive power supply, a negative power supply, and the like of the scanning line driving circuit 104, which will be described later, via the constant potential lines 31 ". A negative power supply may be used, etc. In Fig. 1, the capacitance formed between the pixel electrode 11 and the capacitance line 31 'is omitted.
[0030]
Further, on the TFT array substrate 1, an inspection circuit 201 which is a circuit for inspecting the quality, defects, and the like of the liquid crystal device during manufacturing or at the time of shipment, and a plurality of data lines 35 obtained by sampling the image signal. A sampling circuit 301 for supplying data, a data line driving circuit 101, and a scanning line driving circuit 104 are formed.
[0031]
At this time, the scanning line driving circuit 104 performs the timing described later (FIG. 8) based on the power supply voltage and the reference clock supplied from the external control circuit and the start signal DY supplied from the outside via the mounting terminal 102. A scanning signal is applied to the scanning line 31 in a pulsed manner in a line-sequential manner. In parallel with this, the scanning line drive circuit 104 applies a predetermined constant voltage to each capacitance line 31 via the constant voltage line 31 ″.
[0032]
On the other hand, the data line driving circuit 101 controls the six image input signal lines VID1 to VID6 based on a power supply voltage, a reference clock, and the like supplied from the external control circuit in accordance with the timing at which the scanning line driving circuit 104 applies a scanning signal. For each of the data lines 35, a sampling circuit drive signal is supplied to the sampling circuit 301 via the sampling circuit drive signal line 306.
[0033]
Further, in the sampling circuit 301, a TFT 302 is provided for each data line 35, the image input signal lines VID1 to VID6 are connected to the source electrode of the TFT 302, and the sampling circuit drive signal line 306 is connected to the gate electrode of the TFT 302. Then, when six parallel image signals expanded into six phases are input through the image input signal lines VID1 to VID6, these image signals are sampled.
[0034]
When a sampling circuit drive signal is input from the data line drive circuit 101 via the sampling circuit drive signal line 306, the image signals sampled for each of the six image input signal lines VID1 to VID6 are sequentially sent to the data line 35. Is applied. As another driving method, for example, a sampling circuit driving signal may be simultaneously applied to the gate electrodes of the six adjacent TFTs 302 to sequentially select a plurality of data lines 35 for each group. In this case, the same display can be performed by adjusting the phase timing of the six image signals VID1 to VID6 developed by the external control circuit, for example, and supplying them to the data line 35 via the TFT 302. Further, the number of phase expansions of the image signal is not limited to six. For example, if the sampling capability of the TFT 302 included in the sampling circuit 301 is high, the number of phase expansions may be 6 or less. If the sampling capability is low, the number of phase expansions may be 6 or more. The smaller the number of phase expansions of the image signal, the lower the cost of the external control circuit. It goes without saying that image input signal lines are required at least for the number of phase expansions of image signals. Further, if the number of phase expansions of the image signal is set to a multiple of 3, such as 3, 6, 12, 18, 24,..., The image input signal line can be formed in a multiple of 3, which is advantageous for video display. . This is because the color image signal is a multiple of 3 because of the fact that the color image signal is composed of signals related to three colors (red, green, and blue) when controlling video display such as NTSC display and PAL display. This is because it is preferable for simplifying the circuit.
At this time, the inspection circuit 201 and the sampling circuit 301 are arranged in a hatched area in FIG. 1 and as shown in FIGS. 2 and 3, the TFT array at a position facing the light-shielding peripheral partition 53 formed on the counter substrate 2. It may be provided on the substrate 1. This is because, by providing the inspection circuit 201, the sampling circuit 301, and the counter electrode potential line 103 below the peripheral partition 53, which was a dead space in the past, the effective display area in the liquid crystal device 200 is not reduced, and at the same time, In particular, since the peripheral partition 53 is light-blocking, it is not necessary to provide a configuration for blocking light incident through the image display area to the TFTs 202 and 302 included in the inspection circuit 201 and the sampling circuit 301. In addition, since the inspection circuit 201 and the sampling circuit 301 are not formed in the portion of the TFT array substrate 1 facing the sealing material 52, the TFT 302 and the like constituting these circuits are destroyed by the gap material mixed in the sealing material 52. This is because there is an advantage that there is no fear of performing. In the present embodiment, the data line driving circuit 101 and the scanning line driving circuit 104 are provided on a peripheral portion of the TFT array substrate 1 not facing the liquid crystal layer 50. However, if the passivation film can protect peripheral circuits such as the data line driving circuit 101 and the scanning line driving circuit 104, they can be formed in the liquid crystal layer 50.
[0035]
2 and 3, on the TFT array substrate 1, an image display area defined by the plurality of pixel electrodes 11 (that is, an area where an image is actually displayed due to a change in the alignment state of the liquid crystal layer 50). A sealing material 52 as a sealing means made of a photocurable resin surrounding the liquid crystal layer 50 by bonding the two substrates together is provided along the image display area. The sealing material 52 is an adhesive made of, for example, a photo-curing resin or a thermosetting resin for bonding two substrates, that is, the TFT array substrate 1 and the opposing substrate 2 as a second substrate, around the two substrates. A gap material such as a spherical or cylindrical glass fiber or a glass bead for sandwiching the sealing material 52 between the two substrates to set a predetermined distance (thickness of the liquid crystal layer 50) between the two substrates. Is mixed in.
[0036]
The light-blocking peripheral partition 53 is provided between the seal member 52 and the image display area on the counter substrate 2.
[0037]
When the TFT array substrate 1 is placed in a light-shielding case that is opened corresponding to the image display area later, the peripheral parting 53 causes the image display area to open due to a manufacturing error or the like. A band-like light-shielding portion having a width of at least 500 μm or more around the image display area so as not to be hidden by the edge, that is, to allow a shift of about several hundred μm with respect to the case of the TFT array substrate 1, for example. It is formed of a material. Specifically, such a light-shielding peripheral partition 53 is formed on the counter substrate 2 by sputtering using a metal material such as Cr (chromium) or Ni (nickel), a photolithography process, an etching process, or the like. You. In addition, as another example of the peripheral parting 53, it may be formed from a material such as resin black in which carbon or Ti (titanium) is dispersed in a photoresist.
[0038]
As shown in FIG. 2, the entire area facing the image display area inside the peripheral partition 53 on the counter substrate 2 is made of ITO or the like for applying an electric field to the liquid crystal layer 50 together with the respective pixel electrodes 11. A counter electrode 23 is formed.
[0039]
Next, as shown in FIG. 2, a data line driving circuit 101 and a mounting terminal 102 are provided along a lower side of the image display area in an area outside the seal material 52, and two left and right sides of the image display area are provided. A scanning line driving circuit 104 is provided along both sides of the image display area. If the signal delay of the scanning line does not matter, it is needless to say that the scanning line may be formed on only one of them. Further, the data line driving circuits 101 may be arranged on both sides along the side of the screen display area. For example, the odd-numbered data lines supply an image signal from a data line driving circuit arranged along one side of the screen display area, and the even-numbered data lines extend along the opposite side of the screen display area. The image signal may be supplied from the provided data line driving circuit. If the data lines 35 are driven in a comb-tooth shape as described above, the area occupied by the data line driving circuit can be expanded, so that a complicated circuit can be formed. Needless to say, the above-described method of driving in a comb shape can be applied to the scanning line driving circuit 104. Further, a plurality of wirings 105 are provided on the upper side of the image display area.
[0040]
In addition, at the four corners of the sealing material 52, for example, at the four corners of the counter substrate 2, upper and lower conductive terminals as conductive means for establishing electrical continuity between the TFT array substrate 1 and the counter electrode 23. 107 and an upper / lower conductive member 106 made of a conductive material contained in the upper / lower conductive terminal 107. The opposite substrate 2 having substantially the same contour as the sealing material 52 is fixed to the TFT array base 1 by the sealing material 52.
[0041]
Here, the counter electrode 23 has a constant potential V described later as described above. _LCCOM In general, the counter electrode 23 is kept at a constant potential V with respect to the four upper and lower conductive terminals 107. _LCCOM Is supplied via the counter electrode potential line 103 and the mounting terminal 102 (both are formed on the TFT array substrate 1) which are the conductive lines according to the present invention shown in FIG. . Then, the potential signal LCCOM is supplied to the counter electrode 23 via the vertical conductive terminal 107 (vertical conductive material 106), so that the counter electrode 23 has the constant potential V. _LCCOM Is kept.
[0042]
Here, the arrangement of the common electrode potential line 103 according to the present invention will be described in particular with reference to FIG. 1. The common electrode potential line 103 is connected to an external control circuit via mounting terminals 102 arranged at the start end and the end, respectively. Is connected to
[0043]
Then, on the TFT array substrate 1, the counter electrode potential lines 103 are disposed so as to bypass the data line driving circuit 101 and the image input signal lines VID1 to VID6 at first, and the two at the lower side in FIG. Connected to upper and lower conductive terminals 107.
[0044]
Next, the counter electrode potential lines 103 connected to the two upper and lower conductive terminals 107 are connected to the area on the TFT array substrate 1 facing the peripheral partition 53 between the scanning line drive circuit 104 and the image display area, respectively. 1 and reaches the conductive layer 108 at the upper part of the inspection circuit 201 in FIG. Then, it branches right and left from the conductive layer 108 and is connected to two upper and lower conductive terminals 107 located at the upper part in FIG.
[0045]
At this time, the conductive layer 108 is a layer formed of aluminum in a region of the TFT array substrate 1 corresponding to a lower portion of the sealing material 52, and serves to supply the potential signal LCCOM to the two upper and lower conductive terminals 107 in the upper portion. In addition, by being formed below the sealing material 52 containing the spacer, it also plays a role of controlling the cell gap between the TFT array substrate 1 and the opposing substrate 2.
[0046]
The conductive layer 108 itself has a lattice shape as shown in FIG. The reason why the lattice shape is used is that when the sealing material 52 is filled and then cured, external light necessary for curing to a sufficient hardness reaches the filled sealing material 52. It is.
[0047]
Here, the inspection circuit 201 and the sampling circuit 301 are basically AC driven circuits. Therefore, even if the precharge circuit 201 and the sampling circuit 301 are provided in the portion of the TFT array substrate 1 which faces the liquid crystal layer 50 surrounded by the sealing material 52 and sandwiched between the two substrates, The problem of deterioration of 50 does not occur.
[0048]
By providing the inspection circuit 201 and the sampling circuit 301 below the peripheral partition 53 in this manner, the scanning line driving circuit 104 and the data line driving circuit 101 are formed in the peripheral portion of the TFT array substrate 1 with a margin. And it becomes easier to design these peripheral circuits to meet specific specifications.
[0049]
(II) Detailed configuration of counter electrode potential lines, etc.
Next, actual detailed configurations of the counter electrode potential line 103 and the upper and lower conductive terminals 107 according to the present invention will be described with reference to FIGS.
[0050]
First, the configuration near the upper and lower conductive terminals 107 located at the lower left in FIG. 1 will be described with reference to FIGS. 4 and 5.
[0051]
As shown in FIG. 4, the counter electrode potential line 103 is connected to the external control circuit circuit by the mounting terminal 102, and the data line drive circuit 101 (the test terminal 114 for testing the data line drive circuit 101 is connected). Bypassing the image input signal lines VID1 to VID6, the extraction line 112 connecting the image input signal lines VID1 to VID6 and the sampling circuit 301, and the sampling circuit drive signal line 306 from the data line drive circuit 101. Connected to the vertical conductive material 106 in the vertical conductive terminal 107 through a region on the TFT array substrate 1 between the drive circuit drive line 112 connected to the scanning line drive circuit 104 and the image input signal lines VID1 to VID6. Have been.
[0052]
In parallel with this, the counter electrode potential line 103 is connected to the upper and lower conductive terminals 107 and is disposed substantially in parallel with the sealing region (see FIG. 4) formed by the sealing material 52. Before crossing the lead line 113 from the scanning line drive circuit 104 connected to the seal line, the seal region is straddled in parallel with the lead line 113, and the position facing the peripheral partition 53 is connected to the upper and lower conductive terminals 107 on the opposite side. It is arranged so as to straddle the scanning line 31 and the capacitance line 31 ′.
[0053]
Next, the connection relationship between the actual counter electrode potential line 103 in the upper and lower conductive terminal 107, the upper and lower conductive material 106, and the counter electrode 23 will be described with reference to FIG. FIG. 5 is a sectional view taken along line AA ′ of the upper and lower conductive terminals 107 in FIG.
[0054]
As shown in FIG. 5, the upper and lower conductive terminals 107 are, from below, the TFT array substrate 1, the first interlayer insulating layer 41, the polysilicon layer 120, the second interlayer insulating layer 42, the counter electrode potential line 103, and the third interlayer insulating layer. Each layer is formed by laminating the layer 43, the molding agent 121, the counter electrode 23, and the counter substrate 2 in this order. The vertical conductive material 106 is mixed in the molding agent 121, and the vertical conductive material 106 contacts the counter electrode potential line 103 and the counter electrode 23 to electrically connect the counter electrode potential line 103 and the counter electrode 23. And the potential signal LCCOM is supplied to the counter electrode 23. For this reason, as described above, spherical or cylindrical glass fibers or the like plated with gold or silver having high conductivity as described above are used.
[0055]
In addition, the molding agent 121 itself also has conductivity, so that the counter electrode 23 and the counter electrode potential line 103 are also electrically connected. More specifically, as the molding agent 121, a material obtained by mixing silver in a paste form and mixing the upper and lower conductive members 106 is used.
[0056]
Note that the molding agent 121 is filled only in a pentagonal area (shown by a diagonal lattice pattern in FIG. 4) in the upper and lower conductive terminals 107 shown in FIG. The input terminals VID1 to VID6 are insulated.
[0057]
On the other hand, the first interlayer insulating layer 41 to the third interlayer insulating layer 43 are formed up to a region such as the TFT 302 included in the sampling circuit 301 and the like, and become a part of the TFT 302 and the like. Are NSG, PSG (P ₂ O ₅ SiO containing ₂ ), BSG (B ₂ O ₃ SiO containing ₂ ), BPSG (P ₂ O ₅ And B ₂ O ₃ SiO containing ₂ ), A silicate glass film, a silicon nitride film, a silicon oxide film, or the like. Here, the first interlayer insulating layer 41 is subjected to an annealing treatment at about 900 ° C. at the time of its manufacture, thereby preventing contamination and flattening the surface.
[0058]
Further, the polysilicon layer 120 is a layer formed to adjust the distance between the counter substrate 2 and the TFT array substrate 1 in accordance with the TFT 30 and the like formed in the image display area. It is electrically insulated.
[0059]
Next, the configuration near the two upper and lower conductive terminals 107 and the conductive layer 108 located on the upper side in FIG. 1 will be described with reference to FIGS. 6 and 7.
[0060]
As shown in FIG. 6, the counter electrode potential line 103 disposed at a position facing the peripheral partition 53 through the upper and lower conductive terminals 107 on the lower side in FIG. 1 is different from the scanning line 31 and the capacitance line 31 ′. It passes through different layers and reaches the conductive layer 108 so as to surround the image display area.
[0061]
The two upper and lower conductive terminals 107 are connected to electrode layers branched from both ends of the upper part of the conductive layer 108, respectively.
[0062]
At this time, the conductive layer 108 has a lattice shape in which rectangular holes are formed at predetermined intervals. With this structure, the resistance to the potential signal LCCOM is reduced, and the conductive layer 108 Even if a part is damaged, the redundancy is enhanced by transmitting the potential signal LCCOM through another part. Furthermore, as described above, also in the curing step of the seal material 52, light for curing from the outside can be sufficiently transmitted to cure the seal material 52.
[0063]
Next, a specific detailed configuration of the conductive layer 108 will be described with reference to FIG. FIG. 7 is an enlarged view of a portion of the conductive layer 108 in FIG. 6 that includes a branch to the upper and lower conductive terminals 107 and a sealing region.
[0064]
As shown in FIG. 7, in an actual liquid crystal device 200, a conductive layer 108 (shown by a dashed line in FIG. 7) and a grid-like conductive layer 108 connecting the counter electrode potential line 103 and the upper and lower conductive terminals 107 are provided. A sub-conductive layer 108 ′ (shown by a solid line in FIG. 7) in a ribbon shape and parallel to each other is formed on different layers in the same region. The conductive layer 108 and the sub-conductive layer 108 ′ are interconnected by a plurality of contact holes 38. The sub-conductive layer 108 'is formed such that a plurality of rows of ribbon-shaped electrodes are arranged in parallel over the entire region where the conductive layer 108 is formed.
[0065]
Further, as a material for forming each of them, the conductive layer 108 is formed of an aluminum film, and the sub-conductive layer 108 'is formed of a polysilicon film.
(III) Operation of liquid crystal device
Next, the operation of the liquid crystal device 200 configured as described above will be described with reference to FIGS.
[0066]
First, the scanning line drive circuit 104 applies a scanning signal to the scanning line 31 in a pulsed line-sequential manner at a predetermined timing.
[0067]
In parallel with this, when receiving six parallel image signals developed in six phases from the six image input signal lines VID1 to VID6, the sampling circuit 301 samples these image signals.
[0068]
On the other hand, the data line driving circuit 101 supplies a sampling circuit driving signal for each of the six image input signal lines VID1 to VID6 for each data line in accordance with the timing at which the scanning line driving circuit 104 applies the gate voltage. The TFT 302 of the sampling circuit 301 is turned on. Thus, the image signals sampled by the sampling circuit 301 are sequentially applied to the six adjacent data lines 35. That is, the data line driving circuit 101 and the sampling circuit 301 supply the data lines 35 with six parallel image signals expanded from the six input phases input from the image input signal lines VID1 to VID6.
[0069]
Then, in the TFT 30 to which both the scanning signal and the image signal are applied, a voltage is applied to the pixel electrode 11 via the source region, the channel forming region, and the drain region. Thereafter, the voltage of the pixel electrode 11 is maintained by the storage capacitor for a time that is, for example, three orders of magnitude longer than the time during which the source voltage is applied.
[0070]
During the above operation, the counter electrode 23 is kept at a constant potential V by applying the potential signal LCCOM. _LCCOM Is kept.
[0071]
Here, the constant potential V _LCCOM The above operation, including the setting method described above, will be specifically described with reference to a timing chart shown in FIG. FIG. 8 shows the waveform of each signal applied to the pixel electrode 11. In FIG. _G Represents the waveform of the scanning signal output from the scanning line driving circuit 104 based on the start signal DY, reference numeral VID1 represents a change in the image signal among the image signals developed in six phases, and reference numeral V _LCCOM Indicates a change in the potential signal LCCOM, and _P Indicates a potential change in the corresponding pixel electrode 11.
[0072]
FIG. 8 illustrates a case where a so-called NTSC video signal including two interlaced fields (a first field and a second field) is input as an image signal. Here, in general, when video display is performed using the liquid crystal device 200, a 30 Hz image signal that is AC-reversed every one field period (1/60 second) is converted into a non-interlace method (an odd-numbered image signal and an even-numbered image signal). An image signal is applied to the liquid crystal device 200 in a manner of being written on the same line).
[0073]
T between selected machines shown in FIG. ₁ In one horizontal scanning period, when the TFT 30 is turned on as a result of the input of the scanning signal, the potential V of the pixel electrode 11 is increased. _P Becomes equal to the potential VID1 of the image signal. On the other hand, the non-selection period T ₂ Then, the TFT 30 is turned off, and the signal written by the liquid crystal capacitance and the storage capacitance is held.
[0074]
Then, the next selection period T ₁ When the scanning signal is applied again and the TFT 30 is turned on, this means that the negative image signal is being applied. _P Changes in the negative direction as shown in FIG. ₂ Gradually rises at
[0075]
Hereinafter, the above operation is repeated in response to the application of the scanning signal and the image signal.
[0076]
Here, as shown in FIG. 8, the non-selection period T ₂ At the moment, when the TFT 30 is turned off, the potential V _P Shifts by a predetermined voltage ΔV (generally called a push-down voltage).
[0077]
This is due to the parasitic capacitance C between the gate and drain of the TFT 30. _GD And liquid crystal capacitance C _LC And holding capacity C _ST Due to the capacitive coupling between
[0078]
(Equation 1)
ΔV = (ΔV _G × C _GD ) / (C _GD + C _LC + C _ST )
Indicated by Where ΔV _G Is the amount of change in the potential of the scanning signal.
[0079]
The push-down voltage ΔV is always the potential V of the pixel electrode 11 regardless of the polarity of the image signal (inversion of the signal phase of the image signal). _P Will be lowered.
[0080]
Therefore, the potential V of the counter electrode 23 _LCCOM As the central potential V of the image signal. _C Is set lower by the pushdown voltage ΔV. As a result, the voltage applied to the liquid crystal layer 50 becomes a region shown by oblique lines in FIG.
[0081]
With the above operation, the voltage V is applied to the pixel electrode 11. _P Is applied, the alignment state of the liquid crystal in a portion of the liquid crystal layer 50 sandwiched between the pixel electrode 11 and the counter electrode 23 changes, and in a normally white mode, incident light is changed according to the applied voltage. The liquid crystal portion cannot pass through the liquid crystal portion, and in a normally black mode, incident light can pass through the liquid crystal portion in accordance with the applied voltage. Is emitted.
[0082]
As described above, according to the liquid crystal device 200 of the first embodiment, since the potential signal LCCOM is supplied to the counter electrode 23 from the four corners of the counter electrode 23, even when the sheet resistance of the counter electrode 23 itself is high, the potential signal LCCOM is not changed. The entire counter electrode 23 can be set to a uniform potential.
[0083]
Further, since the mounting terminals 102 for supplying the potential signal LCCOM are arranged at the start and end of the counter electrode potential line 103, respectively, the potential signal LCCOM can be supplied without delay over the entire counter electrode potential line 103. In addition, the potential of the entire counter electrode 23 can be more uniformly set to a constant potential.
[0084]
Further, since the counter electrode potential line 103 is provided on the TFT array substrate 1 facing the peripheral partition 53 which is not usually used, the utilization efficiency of the area on the TFT array substrate 1 can be improved.
[0085]
Furthermore, since the planar conductive layer 108 forms a part of the counter electrode potential line 103 and the conductive layer 108 has a lattice shape, the resistance of the counter electrode potential line 103 itself can be reduced. However, even if a part of the lattice is lost, the counter electrode potential line 103 is not broken.
[0086]
In addition, since the sub-conductive layer 108 ′ connected to the conductive layer 108 between layers is formed on a different layer from the conductive layer 108 on the TFT array substrate 1, the conductive layer 108 is damaged and the like, so that electrical connection can be established. Even if it disappears, the sub-conductive layer 108 ′ can transmit the potential signal LCCOM as the counter electrode potential line 103 instead of the conductive layer 108.
[0087]
Further, since the counter electrode potential line 103 is formed of the same material as the material forming either the data line 35 or the scanning line 31, the counter electrode potential line 103 is formed when forming either the data line 35 or the scanning line 31. The counter electrode potential line 103 can be formed in the same step.
[0088]
In the above-described first embodiment, the inspection circuit 201 and the sampling circuit 301 are provided. However, instead of or in addition to these, the pixel electrode is provided under the peripheral parting 53 prior to the application of the image signal. 11 potential V _P May be provided for supplying a precharge signal to the data line 35 for setting the potential of the data line to a predetermined potential. If this precharge circuit is provided below the peripheral parting line 53, the scanning line driving circuit 104 and the data line driving circuit 101 can be formed with a margin in the peripheral portion of the TFT array substrate 1, and the effective display in the liquid crystal device can be realized. There is no reduction in area.
[0089]
Since the above-described liquid crystal device 200 is applied to a liquid crystal projector, three liquid crystal devices 200 are respectively used as light valves for RGB, and each panel is separated through a dichroic mirror for RGB color separation. The light of each color is incident as incident light. Therefore, in each embodiment, no color filter is provided on the opposing substrate 2.
[0090]
However, in the liquid crystal device 200 as well, an RGB color filter may be formed on the opposing substrate 2 in a predetermined region facing the pixel electrode 11 together with its protective film. In this way, the liquid crystal device 200 of the embodiment can be applied to a color liquid crystal device such as a direct-view or reflection type color liquid crystal television other than the liquid crystal projector.
[0091]
Further, in the liquid crystal device 200, the liquid crystal layer 50 is composed of a nematic liquid crystal as an example. However, if a polymer dispersed liquid crystal in which the liquid crystal is dispersed as fine particles in a polymer is used, the alignment films 12 and 22 and the aforementioned This eliminates the need for a polarizing film, a polarizing plate, and the like, and provides advantages of higher brightness and lower power consumption of the liquid crystal device due to an increase in light use efficiency.
[0092]
Furthermore, if the pixel electrode 11 is made of a metal film having a high reflectance such as Al, when the liquid crystal device 200 is applied to a reflection type liquid crystal device, SH ( Super homeotropic) type liquid crystal can be used.
[0093]
Further, a micro lens may be formed on the counter substrate 20 so as to correspond to each pixel. By doing so, the light collection efficiency of incident light is improved, and a brighter liquid crystal device can be realized.
[0094]
Furthermore, in the liquid crystal device 200, the common electrode 21 is provided on the side of the counter substrate 2 so as to apply a vertical electric field (vertical electric field) to the liquid crystal layer 50. Each of the pixel electrodes 11 is composed of a pair of electrodes for generating a horizontal electric field so as to apply an electric field (that is, without providing an electrode for generating a vertical electric field on the side of the counter substrate 2, the side of the TFT array substrate 1). It is also possible to provide an electrode for generating a lateral electric field at the same time. The use of the horizontal electric field is more advantageous in widening the viewing angle than the case of using the vertical electric field.
[0095]
In the above-described embodiment, the upper and lower conductive terminals 107 are arranged at the four corners of the counter electrode 23. However, when the image display area is particularly large, the position of one pixel at the center of the image display area may be used. The upper and lower conductive terminals may be formed at the same time.
[0096]
Furthermore, when the image display area is, for example, circular, the same effects as those of the present invention can be obtained even if the upper and lower conductive terminals are evenly arranged on the periphery of the circular shape.
(IV) Embodiment of electronic device
Next, embodiments of various electronic apparatuses using the liquid crystal device 200 of the above-described embodiment will be described with reference to FIGS.
[0097]
An electronic device including the above-described liquid crystal device 200 includes a display information output source 1000, a display information processing circuit 1002, a display driving circuit 1004, a liquid crystal panel 1006, a clock generation circuit 1008, and a power supply circuit 1010 illustrated in FIG. It consists of.
[0098]
The display information output source 1000 includes a memory such as a ROM (Read Only Memory) and a RAM (Random Access Memory), a tuning circuit for tuning and outputting a television signal, and the like. Display information such as a video signal is output based on the clock signal.
[0099]
The display information processing circuit 1002 processes and outputs display information based on the clock signal from the clock generation circuit 1008. The display information processing circuit 1002 can include, for example, an amplification / polarity inversion circuit, a phase expansion circuit, a rotation circuit, a gamma correction circuit, a clamp circuit, and the like.
[0100]
Next, the display driving circuit 1004 includes a scanning line driving circuit and a data line driving circuit, and drives the liquid crystal device 1006 for display.
[0101]
Then, the power supply circuit 1010 supplies power to each of the above-described circuits.
[0102]
As the electronic apparatus having the above-described configuration, a liquid crystal projector shown in FIG. 10, a personal computer (PC) and an engineering workstation (EWS) for multimedia shown in FIG. 11, a pager shown in FIG. And a viewfinder-type or monitor-directed video tape recorder, an electronic organizer, an electronic desk calculator, a car navigation device, a POS terminal, and a device having a touch panel.
[0103]
FIG. 10 is a schematic configuration diagram illustrating a main part of the projection display device. In the figure, 1100 is a light source, 1106 and 1108 are dichroic mirrors, 1110, 1112 and 1114 are reflection mirrors, 1116, 1118 and 1120 are relay lenses, 1124, 1126 and 1158 are liquid crystal light bulbs including the liquid crystal device according to the present invention, and 1130. Denotes a cross dichroic prism, 1132 denotes a projection lens.
[0104]
The light source 1100 includes a lamp 1102 such as a metal halide and a reflector 1104 for reflecting light from the lamp.
[0105]
The dichroic mirror 1106 that reflects blue light and green light transmits red light of the self-color light flux from the light source 1100 and reflects blue light and green light. The transmitted red light is reflected by the reflection mirror 1114 and is incident on the liquid crystal light valve 1124 for red light.
[0106]
On the other hand, green light of the color light reflected by the dichroic mirror 1106 is reflected by the green light reflecting dichroic mirror 1108 and is incident on the green light liquid crystal light valve 1126.
[0107]
Further, the blue light also passes through the second dichroic mirror 1108. For blue light, a light guide 1122 composed of a relay lens system including an incident lens 1116, a relay lens 1118, and an emission lens 1120 is provided to prevent light loss due to a long optical path. The light enters the liquid crystal light valve for light 1128.
[0108]
The three color lights modulated by the respective light valves enter the cross dichroic prism 1130. This prism is formed by bonding four right-angle prisms, and a dielectric multilayer film that reflects red light and a dielectric multilayer film that reflects blue light are formed in a cross shape on the inner surface. The three color lights are combined by these dielectric multilayer films to form light representing a color image. The combined light is projected on a screen 1134 by a projection lens 1132 which is a projection optical system, and an image is enlarged and displayed.
[0109]
A personal computer 1200 shown in FIG. 11 includes a main body 1204 having a keyboard 1202, and a liquid crystal display module 1206 including the liquid crystal device of the present invention.
[0110]
In the pager 1300 shown in FIG. 12, two elastic conductors 1314 and 1316 and a film carrier table 1318 connect the liquid crystal device substrate 1304 and the circuit substrate 1308. Here, the liquid crystal device substrate 1304 is a device in which liquid crystal is sealed between two transparent substrates 1304a and 1304b, thereby forming at least a dot matrix type liquid crystal device. The drive circuit 1004 illustrated in FIG. 9 or the display information processing circuit 1002 can be formed over one of the transparent substrates. Circuits not mounted on the liquid crystal device substrate 1304 are external circuits of the liquid crystal device substrate, and can be mounted on the circuit substrate 1308 in the case of FIG.
[0111]
In addition, a circuit board 1308 is required in addition to the liquid crystal device substrate 1304. In the case where a liquid crystal device is used as one component for an electronic device and a display driving circuit or the like is mounted on a transparent substrate, The minimum unit of the liquid crystal device is a liquid crystal device substrate 1304. Alternatively, a structure in which the liquid crystal device substrate 1304 is fixed to a metal frame 1302 serving as a housing can be used as a liquid crystal device which is one component of an electronic device. Further, in the case of the backlight type, a liquid crystal device can be configured by incorporating a liquid crystal device substrate 1304 and a light guide 1306 having a backlight 1306a in a metal frame 1302.
[0112]
Instead, as shown in FIG. 13, an IC chip 1324 is mounted on a polyimide tape 1322 having a metal conductive film formed on one of two transparent substrates 1304a and 1304b constituting a liquid crystal device substrate 1304. By connecting a TCP (Tape Carrier Package) 1320, the liquid crystal device can be used as a liquid crystal device which is a component of an electronic device.
[0113]
The present invention is not limited to the above embodiments, and various modifications can be made within the scope of the present invention. For example, the present invention is not limited to being applied to driving the above-described various liquid crystal devices, but is also applicable to an electroluminescent display device or a plasma display device.
[0114]
【The invention's effect】
As described above, according to the present invention, a potential is supplied to the counter electrode from a plurality of, for example, four corners of the counter electrode. Therefore, even when the resistance of the counter electrode itself is high, the entire counter electrode is set to a uniform potential. can do. Therefore, an image with less flicker or the like can be displayed.
[Brief description of the drawings]
FIG. 1 is a block diagram of various wirings, peripheral circuits, and the like formed on a TFT array substrate.
FIG. 2 is a plan view illustrating an overall configuration of a liquid crystal device.
FIG. 3 is a cross-sectional view illustrating an entire configuration of a liquid crystal device.
FIG. 4 is an enlarged view showing a configuration of a counter electrode potential line and upper and lower conductive terminals on a TFT array substrate.
FIG. 5 is a cross-sectional view of a vertical conduction terminal.
FIG. 6 is an enlarged view showing the configuration of upper and lower conductive terminals and conductive layers on a TFT array substrate.
FIG. 7 is an enlarged view of a conductive layer.
FIG. 8 is a timing chart illustrating an operation of the liquid crystal device.
FIG. 9 is a block diagram illustrating a schematic configuration of an electronic device.
FIG. 10 is a cross-sectional view illustrating a configuration of a liquid crystal projector as an example of an electronic apparatus.
FIG. 11 is a front view illustrating an appearance of a personal computer as an example of an electronic apparatus.
FIG. 12 is an exploded perspective view illustrating a configuration of a pager as an example of an electronic apparatus.
FIG. 13 is a perspective view illustrating an appearance of a liquid crystal device using TCP as an example of an electronic apparatus.
[Explanation of symbols]
1: TFT array substrate
2: Counter substrate
11: Pixel electrode
23 ... Counter electrode
30 ... TFT
31 ... Scanning line
31 '... Capacitance line
31 "... constant potential line
35 ... data line
38 ... Contact hole
41: first interlayer insulating layer
42 ... second interlayer insulating layer
43 ... third interlayer insulating layer
50 ... Liquid crystal layer
52 ... Seal material
53 ... Close-up
101: Data line drive circuit
102 mounting terminals
103: Counter electrode potential line
104 ... scanning line drive circuit
105 ... wiring
106 ... vertical conductive material
107 ... vertical conduction terminal
108 ... conductive layer
108 '... sub-conductive layer
110, 113 ... Leader
112 ... Drive circuit drive line
120: polysilicon layer
121 ... molding agent
200 ... Liquid crystal device
201… Inspection circuit
301 ... Sampling circuit
302 ... TFT
306 ... Sampling circuit drive signal line

Claims (7)

The first substrate includes a plurality of data lines to which an image signal is supplied, a plurality of scanning lines to which a scanning signal is supplied, a switching element connected to the data line and the scanning line, and a switching element connected to the switching element. An electro-optical device having an image display area including a pixel electrode and a counter electrode on the second substrate;
On the first substrate, a conductive line for supplying a predetermined potential to the counter electrode is formed along an outer periphery of the image display area, and the conductive line is opposed to the conductive line outside the image display area. An electro-optical device comprising a plurality of conducting means for conducting with an electrode. The electro-optical device according to claim 1,
An electro-optical device, wherein an external input terminal for supplying the potential from the outside to the conductive line is disposed at a start end and an end of the provided conductive line, respectively. The electro-optical device according to claim 1, wherein
Sealing means for bonding the first substrate and the second substrate in an area surrounding the image display area on the first substrate and the second substrate;
In a region between the sealing means and the image display region, a light-shielding peripheral parting formed on the first or second substrate along an outline of the image display region,
The electro-optical device according to claim 1, wherein the conductive line is provided in a region on the first substrate facing the peripheral partition. The electro-optical device according to any one of claims 1 to 3,
A conductive layer having a planar lattice shape formed together with the conductive lines is arranged in a region outside the image display region adjacent to at least one side forming an outline of the image display region. Electro-optical device. The electro-optical device according to claim 4,
The electro-optical device according to claim 1, further comprising a sub-conductive layer formed on the first substrate in a layer different from the conductive layer and connected to the conductive layer. The electro-optical device according to any one of claims 1 to 5,
An electro-optical device, wherein the conductive line is formed of the same material as one of the data line and the scanning line. An electronic apparatus comprising the electro-optical device according to claim 1.

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