Image display device

Abstract

To provide a image display device capable of preventing a malfunction of a drive circuit, reducing the size of an outer frame of an image display device, and achieving a sufficient EMI countermeasure. The image display device has a drive circuit mounted in a region out of a display portion on one of opposing and connected to signal lines formed in a region of the display portion, wherein a capacitor is formed in the region of the substrate where the drive circuit is mounted.

Description

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to an image display device.

[0003] 2. Description of the Related Art

[0004] An image display device such as a liquid crystal display device of active matrix type has pixel regions surrounded by two neighboring gate signal lines and two neighboring drain signal lines. The gate signal lines extend in the x-direction, and a plurality of the gate signal lines are provided in the y-direction. The drain signal lines extend in they-direction, and a plurality of the drain signal lines are provided in the x-direction. These signal lines are provided on a liquid crystal side in one of opposing transparent substrates with a liquid crystal therebetween.

[0005] In each pixel region, a switching element activated by a scanning signal from one of the neighboring gate signal lines and a pixel electrode applied with an image signal from one of the neighboring drain signal lines through the switching element are formed.

[0006] The pixel electrode is arranged to generate an electric field between the pixel electrode and a counter electrode formed on one of the opposing transparent substrates so that light transmission of the liquid crystal can be controlled by the electric field.

[0007] Scanning line drive circuits connected to the gate signal lines and image signal drive circuits connected to the drain signal lines are mounted on the transparent substrate. For example, it is well known in the art that such drive circuits are formed by semiconductor devices using face down bonding technique.

[0008] In this case, input signals to each of the semiconductor devices are fed from a wiring board (for example, a printed circuit board) arranged in the vicinity of the transparent substrate.

[0009] The wiring board is provided with a bypass capacitor mounted between a power supply line and a ground pattern formed on the wiring board so that transient current necessary to operate each drive circuit is supplied by the bypass capacitor.

SUMMARY OF THE INVENTION

[0010] However, in such configuration of the image display device, i.e. liquid crystal display device, because of a long distance between the bypass capacitor and the drive circuit, a momentary shortage of current supply is often caused by L (inductance) of the wiring, which results in a malfunction of the drive circuit.

[0011] In addition, mounting the capacitor on the wiring board sets limit to size-reduction of the wiring board and prevents so-called an outer frame (a region between outline of display portion and outline of display device) from reducing its size.

[0012] Furthermore, in recent years, a type of a configuration that adjacent drive circuits are connected by wiring each other in order to transfer data in each drive circuit is known in the art. And a countermeasure against EMI caused by the wiring is necessary for adopt very high resolution type display device.

[0013] Accordingly, it is an object of the invention to provide an image display device which can prevent the malfunctions of drive circuits.

[0014] It is another object of the invention to provide an image display device which can reduce the size of so-called an outer frame.

[0015] It is a still further object of the invention to provide an image display device which has a sufficient EMI countermeasure.

[0016] In disclosed aspects according to the invention, some typical configurations are shortly described below.

[0017] That is to say, an image display device according to the invention comprises drive circuits mounted in a region out of an image display portion in one of opposing transparent substrates with a liquid crystal therebetween, wherein the drive circuits are connected to signal lines formed in the liquid crystal display portion, a capacitor is formed in the region where the drive circuit is mounted on the transparent substrate, and one of the electrodes of the capacitor is connected to a terminal for connection to a power supply terminal and a terminal of the drive circuit, while the other electrode is connected to a connection to a ground terminal of the drive circuit respectively.

[0018] Another image display device according to the invention comprises at least one substrate forming an image display device, and the drive circuit formed on the substrate and connected to signal lines formed in a display portion of the image display device, wherein the capacitor is formed in the region of the substrate where the drive circuit is mounted.

[0019] The image display device of the configuration as described above includes a bypass capacitor formed in the region where the drive circuit is mounted, and the bypass capacitor supplies a transient current to the drive circuit when the drive circuit is operated.

[0020] Thus, the bypass capacitor is formed very close to the drive circuit so that influences of L factor caused by the wiring can be largely reduced.

[0021] Consequently, the momentary current can be supplied to the drive circuit in order to prevent the malfunction of the drive circuit.

[0022] Other objects and modes of the invention will become apparent from the following description of the Examples with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more fully understand the drawings used in the detailed description of the invention, a brief description of each drawing is provided.

[0024] FIG. 1 is a schematic diagram of substantial parts showing an example of an image display device according to the invention.

[0025] FIG. 2 is a whole schematic diagram showing an example of an image display device according to the invention.

[0026] FIG. 3 is a plan view showing an example of a pixel in an image display device according to the invention.

[0027] FIG. 4 is a cross-sectional view taken on line IV-IV of FIG. 3.

[0028] FIG. 5 is a cross-sectional view taken on line V-V of FIG. 2.

[0029] FIG. 6 is a schematic diagram of substantial parts showing another example of an image display device according to the invention.

[0030] FIG. 7 is a schematic diagram of substantial parts showing a still another example of an image display device according to the invention.

[0031] FIG. 8 is a schematic diagram of substantial parts showing an even another example of an image display device according to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] Preferred embodiments of present invention for image display device are explain as follows using case of liquid crystal display device.

EXAMPLE 1

[0033] (Equivalent Circuit)

[0034] FIG. 2 is an equivalent circuit diagram showing an example of a liquid crystal display device according to the invention. The circuit diagram shown in FIG. 2 is represented in accordance with actual geometry of the liquid crystal display device.

[0035] In FIG. 2, a transparent substrate SUB1 is arranged to an opposing transparent substrate SUB2 with a liquid crystal interposed therebetween.

[0036] On a liquid crystal side of the transparent substrate SUB1, gate signal lines GL each extends in the x-direction of FIG. 2 and is parallel with each other in the y-direction, and drain signal lines DL insulated from the gate signal lines GL each extends in the y-direction and is parallel with each other in the x-direction. A display part AR is arranged by a set of each pixel region which forms a rectangular like region surrounded by the respective signal lines.

[0037] A thin film transistor TFT driven by a scanning signal (voltage) fed through one of the neighboring gate signal lines GL and a pixel electrode PIX fed with an image signal (voltage) through one of the neighboring drain signal lines via the thin film transistor TFT are formed in each pixel region.

[0038] A capacitor element Cadd is formed between the pixel electrode PIX and the other gate signal line GL adjacent to the gate signal line GL which feeds the scanning signal, and the capacitor element Cadd stores the image signal fed to the pixel electrode PIX for a long period when the thin film transistor TFT is turned off.

[0039] A counter electrode CT (not shown) is formed commonly in each pixel region on a surface of a liquid crystal side in the transparent substrate SUB2, and the liquid crystal is interposed between the opposing substrates SUB1 and SUB2. An electric field is generated between the counter electrode CT and the pixel electrode PIX in each pixel region so that light transmission of the liquid crystal between the electrodes is controlled.

[0040] One end of each gate signal line GL is extended to one side of the transparent substrate SUB1 (left side in FIG. 2). Terminals GTM are formed in this extended region of the gate signal lines GL and connected to bumps of a semiconductor integrated circuit GDRC including vertical scanning circuits. The semiconductor integrated circuit GDRC is mounted on the transparent substrate SUB1. One end of each drain signal line DL is also extended to one side of the transparent substrate SUB1 (upside in FIG. 2), and terminals DTM are formed in this extended region of the drain signal lines DL and connected to bumps of a semiconductor integrated circuit DDRC including image signal drive circuits. The semiconductor integrated circuit DDRC is mounted on the transparent substrate SUB1.

[0041] Each of the semiconductor integrated circuits GDRC and DDRC itself is completely mounted on the transparent substrate SUB1, and it is so-called COG (chip on glass) technique.

[0042] Each of the bumps in input sides of the semiconductor integrated circuits GDRC and DDRC is also connected to terminals GTM2 and DTM2 formed on the transparent substrate SUB1, respectively, while the terminals GTM2 and DTM2 are connected to terminals GTM3 and DTM3 arranged in the closest portion to an edge of the transparent substrate SUB1 through each wiring layer.

[0043] FIG. 5 shows a cross-sectional view taken on line V-V in FIG. 2. In FIG. 5, each bump of the semiconductor integrated circuit DDRC is connected to the terminals DTM and DTM2 with an anisotropic conductive film ACF.

[0044] Such characteristics of the COG technique make it possible that the bumps in the output sides of the semiconductor integrated circuits GDRC and DDRC are formed with a very short distance to each other, and therefore, both the terminal GTMs of the gate signal lines GL and terminal DTMs of the drain signal lines DL are formed with a quite short distance to each other.

[0045] Consequently, a contact space for each terminal GTM of the gate signal lines GL and each terminal DTM of the drain signal lines DL as well as each bump in output sides of the semiconductor integrated circuits GDRC and DDRC is so small that an increase of contact resistance between the bumps and the terminals GTM and DTM cannot be neglected.

[0046] The transparent substrate SUB2 is arranged to oppose the transparent substrate SUB1 avoiding the region where the semiconductor integrated circuits are mounted, and is smaller than the transparent substrate SUB1 in space.

[0047] The transparent substrate SUB2 is fixed to the transparent substrate SUB1 by sealing material SL formed along the periphery of the transparent substrate SUB2, and the sealing material SL also has a sealing function of the liquid crystal LC between the transparent substrates SUB1 and SUB1.

[0048] (Configuration of Pixel)

[0049] FIG. 3 is a plan view showing the configuration of the pixel portion in the transparent substrate SUB1 and corresponds to a part shown by a dotted line frame A in FIG. 2.

[0050] FIG. 4 shows a cross-sectional view taken on line IV-IV in FIG. 3 and also shows across-sectional view of the transparent substrate SUB2.

[0051] In FIG. 3, the gate signal lines GL are formed on a liquid crystal side surface of the transparent substrate SUB1, each extending in the x-direction and being parallel with each other in the y-direction.

[0052] The gate signal line GL, in this example, has a double-layer structure, an upper layer of which is made of alloys of Al and Nd (such alloys are represented by Al—Nd, hereinafter), and a lower layer of which is made of alloys of Mo and Zr (such alloys are represented by Mo—Zr, hereinafter).

[0053] The double-layer structure is employed because it can largely reduce the resistance and show a cross-section of a forward tapered shape in the process for selective etching.

[0054] Furthermore, an insulating film GI made of SiN, for example, is formed on the surface of the liquid crystal side of the transparent substrate SUB1 including the gate signal lines GL.

[0055] The insulating film GI serves for the drain signal line DL described later as an interlayer insulating film from the gate signal GL, as a gate insulating film for the thin film transistor TFT described in detail below, and as a dielectric film for the capacitance element Cadd also described in detail below.

[0056] In a lower left portion of the pixel region, a semiconductor layer AS of an i-type semiconductor (an intrinsic semiconductor: a semiconductor undoped conductive impurities) made of a-Si, for example, is formed in an overlapping portion with the gate signal line GL.

[0057] A source electrode and a drain electrode are formed on the upper surface of the semiconductor layer AS so that the semiconductor layer of an MIS type of a thin film transistor TFT having a part of the gate signal line GL as a gate electrode is obtained.

[0058] The source electrode SD1 and the drain electrode SD2 in the thin film transistor TFT as well as the drain signal line DL formed on the insulating layer GI are formed at one time.

[0059] That is, the drain signal lines DL each extending in the y-direction and provided parallel with each other in the x-direction of FIG. 3 are formed, and a part of the drain signal line DL is extended up to the surface of the semiconductor layer AS in order to make the extended part to form the drain electrode SD2 of the thin film transistor TFT.

[0060] At the same time, the electrode formed apart from the drain electrode SD2 becomes the source electrode SD1. The source electrode SD1 is connected to the pixel electrode PIX described in detail below, and a pattern of the source electrode SD1 has a slightly extended portion to the center side of the pixel region in order to obtain a connecting area.

[0061] In an interface among the drain electrode SD2, the source electrode SD1 and the semiconductor layer AS, a semiconductor layer doped with impurities is formed to serve as a contact layer.

[0062] The thin semiconductor layer doped with impurities near the surface of the semiconductor layer AS is formed after the formation of the semiconductor layer AS, and the drain electrode SD2 and the source electrode SD1 are formed, then an exposed region of the semiconductor layer doped with impurities is etched by using the electrodes as a mask in order to obtain a configuration described above.

[0063] Then, a protecting film PSV made of SiN, for example, is formed over the surface of the transparent substrate SUB1 including the drain signal lines DL (the drain electrode SD2, the source electrode SD1).

[0064] The protecting film PSV is arranged to avoid direct contact between the thin film transistor TFT and the liquid crystal LC, and a contact hole CH is formed to expose a part of the extended portion of the source electrode SD1 in the thin film transistor TFT.

[0065] The transparent pixel electrode PIX made of ITO (Indium-Tin-Oxide), for example, is formed on an upper surface of the protecting film PSV, covering substantially all the pixel regions.

[0066] Since the pixel electrode PIX is formed covering the contact hole CH of the protecting film PSV, the pixel electrode PIX is connected to the source electrode SD1 in the thin film transistor TFT. In addition, an alignment film ORI1 is formed to cover the surface of the transparent substrate SUB1 on which the pixel electrode PIX is thus formed. The alignment film ORI1 is made of a resin, for example, and surface alignment of the alignment film ORI1 is created by rubbing in a specific direction. The alignment film ORI1 is arranged to contact with the liquid crystal LC so that the direction of initial alignment of liquid crystal molecule in the liquid crystal LC is determined by the alignment film ORI1.

[0067] A polarizing plate POL1 is clad on an opposite surface of the transparent substrate SUB1.

[0068] On the other hand, a black matrix BM dividing each pixel region is formed on the liquid crystal side surface of the transparent substrate SUB2.

[0069] The black matrix BM is arranged to prevent external light from irradiating the thin film transistor TFT and improve the contrast of the display.

[0070] Furthermore, a color filter FIL having a color corresponding to each pixel region is formed in an aperture (a region where light transmits and a substantial pixel region) of the black matrix BM.

[0071] In respective with the color filter FIL, a filter of the same color is adopted for each pixel region provided in the y-direction, and a red filter (R), a green filter (G) and a blue filter (B) are arrayed in turn for each pixel region in the x-direction.

[0072] A planarization film OC made of a resin is applied to the surface of the transparent substrate SUB2 on which the black matrix BM and the color filters FIL are formed as described, covering the black matrix BM and others. The planarization film OC prevents the steps otherwise created by the black matrix BM and the color filters FIL on the surface of the transparent substrate SUB2.

[0073] A counter electrode CT made of an ITO film, for example, is commonly formed in each pixel region on the surface of the planerization film OC.

[0074] An electric field corresponding to the image signal (voltage) is generated between the counter electrode CT and the pixel electrode PIX in each pixel region in order to control the direction of alignment of the liquid crystal LC interposed between these electrodes, and an appropriate combination of the polarizing plate POL1 described above and a polarizing plate POL2 described later permits the light transmission of the liquid crystal LC to control.

[0075] On the surface of the transparent substrate SUB2 on which the counter electrode CT is thus formed, an alignment film ORI2 is formed covering the counter electrode CT as well. The alignment film ORI2 is made of a resin, for example, and has a surface rubbed in a specific direction. The alignment film ORI2 is arranged to contact with the liquid crystal LC so that the direction of the initial alignment of the liquid crystal molecule in the liquid crystal LC is determined by the alignment film ORI2.

[0076] A polarizing plate POL2 is cladded on an opposite side surface of the transparent substrate SUB2.

[0077] Above explanation for pixel region is changeable in type of image display device and other structure of pixel is also included in this invention.

[0078] (Configuration in Region Where Semiconductor Integrated Circuit DDRC is Mounted)

[0079] FIG. 1 is a schematic diagram showing in detail a region where the semiconductor integrated circuit DDRC including the image signal drive circuit is mounted, in which FIG. 1A is a plan view, and FIG. 1B is a cross-sectional view taken on line b-b in FIG. 1A.

[0080] As shown in FIG. 1A, in the region where the semiconductor integrated circuit DDRC is mounted, the terminals DTM2 are formed on one side of the region to be connected to input bumps of the semiconductor integrated circuit DDRC, and the terminals DTM are formed on other sides of the region to be connected to output bumps of the semiconductor integrated circuit DDRC.

[0081] In FIG. 1A, the number of the terminals DTM2 is smaller than that of the terminals DTM, and accordingly, an area of the terminal DTM2 is larger than that of the terminal DTM.

[0082] The terminal DTM is formed as an edge of an extended portion of the drain signal line DL and made of the same material as the drain signal line DL.

[0083] And, a bypass capacitor BC is formed in the region where the semiconductor integrated circuit DDRC is mounted, more correctly, in a region surrounded by the terminals DTM2 and the terminals DTM.

[0084] One of the electrodes, CTM1, of the bypass capacitor BC is made of the same material as the drain signal line DL (CTM1 and the drain signal line DL are formed at one time in this example). The insulating film GI and the protecting film PSV in the liquid crystal display portion AR extend to the region where the semiconductor integrated circuit DDRC is mounted, and the protecting film PSV (a dielectric film) is interposed between the electrodes of the bypass capacitor BC. And, the other electrode CTM2 of the bypass capacitor BC is made of the same material as the pixel electrode PIX (CTM2 and the pixel electrode PIX are formed at one time in this example).

[0085] The electrode CTM1 of the bypass capacitor is formed by extending a selected terminal as a ground terminal in the terminals DTM2, while a part of the other electrode CTM2 is formed by overlapping a selected terminal as a power supply terminal in the terminals DTM2.

[0086] The protecting film PSV covering each terminal DTM2 made of the same material as the drain signal line DL is opened through a hole in order to expose each terminal DTM2, and each exposed surface of the terminals DTM2 is arranged to be covered with the same material (ITO) as the pixel electrode PIX.

[0087] Coating each of the terminals DTM2 and the terminals DTM with ITO, creation of electrolytic corrosion is avoided.

[0088] In the image display device having a configuration described in this example, because the bypass capacitor BC is close to the image signal drive circuit including the semiconductor integrated circuit DDRC (because the bypass capacitor BC is just below the image signal drive circuit), the L (inductance) of the wiring of the bypass capacitor BC becomes small, which allows momentary supply of the current to the image signal drive circuit. Consequently, the malfunction of the image signal drive circuit can be prevented.

[0089] Furthermore, by the configuration described above, it is not necessary to mount the bypass capacitor BC on the wiring board, so that the wiring board can be formed small, and therefor, a so-called outer frame in the liquid crystal display device can be reduced in size.

[0090] The configuration of the region on which one of the image signal drive circuits is mounted is shown in the above-mentioned example, however, other regions provided with other image signal drive circuits are of the same configuration as the region shown in FIG. 1.

[0091] Needless to say, the configuration is not limited to the image signal drive circuits, but the same configuration can be also applied to the scanning signal drive circuits.

[0092] It is noted that the formation of the bypass capacitor BC in the regions of the image signal drive circuit and/or the scanning signal drive circuit is also applied to other examples described below.

EXAMPLE 2

[0093] FIG. 6 is a schematic diagram of another example of a image display device according to the invention, showing an electrode pattern of the bypass capacitor BC shown in FIG. 1.

[0094] For example, when a pin hole created in a dielectric film between the electrode CTM1 in the lower layer and the electrode CTM2 in the upper layer causes them to short circuit, the short circuit portion is cut off from the remaining electrode pattern by using a laser beam, for instance, in order to recover from the short circuit as shown in FIG. 6.

[0095] It is desirable for this intention that the pattern of the bypass capacitor BC is arranged to have a terminal portion (the terminal connected to the bump of the semiconductor integrated circuit including the image signal drive circuit) as a trunk and a plurality of branch portions extended from the trunk portion (the example in FIG. 6 also has the pattern described above).

EXAMPLE 3

[0096] FIG. 7 is a schematic diagram of a still another example of a image display device according to the invention.

[0097] FIG. 7 shows one of a plurality of regions where the semiconductor integrated circuit DDRC including the image signal drive circuit is mounted.

[0098] Each semiconductor integrated circuit DDRC is connected to adjacent semiconductor integrated circuits DDRC on the transparent substrate SUB1 through a plurality of wiring layers WIL. Each wiring layer WIL is arranged to transmit data from one semiconductor integrated circuit DDRC to other semiconductor integrated circuit DDRC.

[0099] Among a plurality of terminals DTM2 connected to the input bump of the semiconductor integrated circuit DDRC, an extended portion of a ground (GND) terminal is formed to reach both the terminals of the wiring layer WIL and an area where the wiring layer WIL is formed.

[0100] In this example, the extended portion from the ground (GND) terminal is formed in a different layer from the wiring layer WIL and may be formed on an upper or lower layer with respect to the each wiring layer WIL when a dielectric film such as the insulating film GI, the protecting film PSV or a laminated material made of these films exists between the layer of the extended portion from the ground (GND) terminal and the wiring layer WIL.

[0101] Consequently, an EMI countermeasure against an electromagnetic wave generated from the wiring layer WIL can be realized without securing a specific space for an EMI countermeasure.

EXAMPLE 4

[0102] FIG. 8 is a schematic diagram of an even another example of a image display device according to the invention and corresponding to FIG. 7.

[0103] A different arrangement compared to FIG. 7 is that an extended portion from the ground (GND) terminal connected to the input bump of the semiconductor integrated circuit DDRC is formed in relatively small area of a region where the semiconductor integrated circuit DDRC is mounted and has only a role of a simple leader line to the extended portion formed on the wiring layer WIL portion.

[0104] However, even in the case, an EMI countermeasure against an electromagnetic wave generated from the wiring layer WIL can be performed well.

[0105] In the above examples according to the invention, it is explained that the liquid crystal display device has a liquid crystal drive system, in which the pixel electrode on one transparent substrate and the counter electrode on the other transparent substrate are arranged to generate the electric field therebetween, and the liquid crystal is driven by the electric field substantially perpendicular to the transparent substrates.

[0106] However, the above examples according to the invention are also applicable to the liquid crystal display device having the liquid crystal drive system, in which the pixel electrode and the counter electrode are arranged on one transparent substrate, and the liquid crystal is driven by substantially the parallel electric field to the transparent substrates among those generated between the electrodes.

[0107] The same problem has been created in both types of the liquid crystal display device because the image signal drive circuit and the scanning signal drive circuit in the both types of the liquid crystal display device have completely the same configuration.

[0108] The configuration according to the invention can be applied to various types of image display device including the liquid crystal display device, an organic electro-luminescent display, a plasma display, an electric paper and other image display devices.

[0109] As explained above, the invention provides a image display device capable of preventing a malfunction of a drive circuit, reducing an area of an outer frame in an image display device, and achieving a sufficient EMI countermeasure.

Claims

1. A liquid crystal display device comprising a drive circuit mounted in a region out of a liquid crystal display portion on one of opposing substrates with a liquid crystal therebetween and connected to signal lines formed in the liquid crystal display portion, wherein a capacitor is formed in the region of the substrate where the drive circuit is mounted.

2. A liquid crystal display device comprising a drive circuit mounted in a region out of a liquid crystal display portion on one of opposing substrates with a liquid crystal therebetween and connected to signal lines formed in the liquid crystal display portion, wherein a capacitor is formed in the region of the substrate where the drive circuit is mounted, and one of electrodes of the capacitor is connected to a terminal for connection to a power supply terminal of the drive circuit and the other electrode is connected to a terminal for connection to a ground terminal of the drive circuit, respectively.

3. A liquid crystal display device comprising a drive circuit mounted in a region out of a liquid crystal display portion on one of opposing substrates with a liquid crystal therebetween and connected to signal lines formed in the liquid crystal display portion, wherein a capacitor is formed in the region of the substrate where the drive circuit is mounted, one of electrodes of the capacitor is connected to a terminal for connection to a power supply terminal of the drive circuit, and the other electrode is connected to a terminal for connection to a ground terminal of the drive circuit, respectively, and each electrode of the capacitor takes a pattern having a trunk portion connected to the power supply terminal or the ground terminal, and a plurality of branch portions extended from the trunk portion.

4. A liquid crystal display device comprising a plurality of drive circuits mounted in a region out of a liquid crystal display portion on one of opposing substrates with a liquid crystal therebetween and connected to signal lines formed in the liquid crystal display portion, wherein the signal lines each extends in one direction and is parallel with each other in a direction crossing the direction in which the signal lines extend, and one drive circuit is allocated to a plurality of the signal lines adjacent each other, each adjacent drive circuit is connected through a wiring layer formed on the substrate, the wiring layer is formed via an insulating film in a region where a conductive layer is formed, and the conductive layer is connected to a terminal for connection to a ground terminal of the drive circuit.

5. An image display device comprising: at least one substrate forming the image display device; and a drive circuit mounted on the substrate and connected to signal lines formed in a display portion of the image display device, wherein a capacitor is formed in a region of the substrate where the drive circuit is mounted.

6. An image display device comprising: at least one substrate forming the image display device; and a drive circuit mounted on the substrate and connected to signal lines formed in a display portion of the image display device, wherein a capacitor is formed in a region of the substrate where the drive circuit is mounted, and one of electrodes of the capacitor is connected to a terminal for connection to a power supply terminal of the drive circuit, and the other electrode is connected to a terminal for connection to a ground terminal of the drive circuit, respectively.

7. An image display device comprising: at least one substrate forming the image display device; and a drive circuit mounted on the substrate and connected to signal lines formed in a display portion of the image display device, wherein a capacitor is formed in a region of the substrate where the drive circuit is mounted, one of electrodes of the capacitor is connected to a terminal for connection to a power supply terminal of the drive circuit, and the other electrode is connected to a terminal for connection to a ground terminal of the drive circuit, respectively, and each electrode of the capacitor takes a pattern having a trunk portion connected to the power supply terminal or the ground terminal, and a plurality of branch portions extended from the trunk portion.

8. An image display device comprising: at least one substrate forming the image display device; and a plurality of drive circuits mounted on the substrate and connected to signal lines formed in a display section of the image display device, wherein the signal lines each extends in one direction and is parallel with each other in a direction crossing the direction in which the signal lines extend, and one drive circuit is allocated to a plurality of the signal lines adjacent each other, each adjacent drive circuit is connected through a wiring layer formed on the substrate, and the wiring layer is formed via an insulating film in a region where a conductive layer is formed, and the conductive layer is connected to a terminal for connection to a ground terminal of the drive circuit.