JP2004355035A - Liquid crystal display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize an image display device which includes a polarizing plate and has a reduced leaky electric field from a display surface. <P>SOLUTION: The image display device includes: two transparent substrates with a liquid crystal layer interposed therebetween; a conductive layer of ≤2×10<SP>3</SP>Ω/square in sheet resistance on the top surface of a top-surface side transparent substrate between the two substrates; and a polarizing plate 2 in a display area on the conductive layer, wherein the conductive layer is electrically connected to a metallic frame 4 formed outside the display area by a conductive connecting material 3 and the connection resistance of the connection being ≤4×10<SP>3</SP>Ω. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image display device having a polarizing plate, and in particular, has an electrically conductive layer on the surface of a display region, and electrically connects the electrically conductive layer to a ground or a constant voltage or an electric field component radiated from the display region. The present invention relates to an image display device in which charging is prevented or leakage of an unnecessary emission field is prevented by applying an alternating voltage of a lower layer.

  In an image display device such as a liquid crystal panel, it is known that dust adheres to the surface of a polarizing plate due to static electricity charged on the surface of the polarizing plate, or that an unnecessary radiation field leaks from a display surface due to the display operation. A similar phenomenon is particularly noticeable in a cathode ray tube. This is because a cathode ray tube irradiates a phosphor layer formed on the back surface of the display surface of the cathode ray tube with a high-voltage electron beam to supply energy to the phosphor layer, cause the phosphor to emit light, and display a display image. For this reason, the surface of the tube of the cathode ray tube is charged to a high voltage, or a phenomenon that an unnecessary width radiation field leaks from the surface of the tube has occurred.

  As a countermeasure, in a cathode ray tube, a conductive layer is generally formed on a display surface. This type of technique is known, for example, from Patent Document 1 and the like. It is known from Patent Document 2 and the like that not only a conductive layer is formed on a display surface but also the effect can be further improved by electrically grounding the conductive layer.

On the other hand, in an image display device having a polarizing plate typified by a liquid crystal display device, charging on the surface of the polarizing plate has not been a problem so far. This is partly because the operating voltage of the liquid crystal display device is several orders of magnitude lower than the operating voltage of the cathode ray tube, and one is that a transparent conductive film as an electrode is formed on almost the entire surface inside the display device, This is because the film itself has the effect of the antistatic layer. However, as an exception, a so-called horizontal electric field type liquid crystal display device has a structure in which electrodes are formed in a comb-like shape because an electric field must be formed in a horizontal direction in the display mode. For this reason, since the ratio of the area where the electrode is not formed in the display area increases, the problem that the display image of the liquid crystal display device is disturbed by static electricity particularly charged on the polarizing plate surface has been clarified by the present inventors. It has been proposed in Patent Document 3 and the like to take measures against this by providing a conductive layer on the substrate surface.
JP-A-63-76247 JP-A-02-82434 JP-A-09-105918

  However, in order to achieve the target level of the leak-free emission field typified by the guidelines of the TCO (Tjanslemanns Central Organization: Swedish labor organization), even in an image display device having a polarizing plate typified by a liquid crystal display device, It has been clarified that it is necessary to realize a configuration that reduces the leakage unnecessary electric field.

  Therefore, an object of the present invention is to provide an image display device having a polarizing plate represented by a liquid crystal display device having a surface antistatic effect.

  Another object of the present invention is to reach a level that satisfies one or both of MPR-2 (Staden Match Proyrad: Swedish National Metrology and Testing Council Guideline), which is a guideline for a leakage-free radiation field. It is another object of the present invention to provide an image display device having a polarizing plate typified by a liquid crystal display device capable of realizing a reduction in the leakage unnecessary electric field.

In order to achieve the above object, the present invention provides an image display device having a polarizing plate on its surface, wherein at least one of the constituent layers of the polarizing plate has a sheet resistance of 10 ¹⁴ Ω / □ or less. Thus, a sufficient antistatic effect can be achieved in the liquid crystal display device.

Further, the present invention provides an image display device having a polarizing plate on its surface, wherein at least one of the constituent layers of the polarizing plate has a sheet resistance of 10 ¹⁴ Ω / □ or less, and an antireflection function is provided on the front surface of the conductive layer. Characterized in that an insulating layer having the following is provided.

  As a result, the conductive layer is protected, and the reliability can be improved.

  Further, in the present invention, in an image display device having a polarizing plate on a surface, the sheet resistance of at least one of the constituent layers of the polarizing plate is set to a certain value or less, and an insulation having an antireflection function is provided on the front surface of the conductive layer. Having a conductive layer, the conductive layer and a metallic frame formed outside the display region are electrically connected to each other through the insulating layer by a conductive connection material, It is characterized in that the connection resistance of the electrical connection is set to a certain value or less.

  Thereby, in the image display device having the polarizing plate on the surface, the unnecessary emission field can be reduced to a level that satisfies the values of the various guidelines.

The values to be achieved for the sheet resistance and the connection resistance of at least one of the constituent layers of the polarizing plate differ depending on the guideline. As will be described in detail in Examples, when the sheet resistance and the connection resistance of one layer are set to 2 × 10 ³ Ω / □ or less and 4 × 10 ³ Ω or less, respectively, ELEF (Extremely Low Frequency Electric Field) of the TCO guideline is used. , VLEF (Very Low Frequency Electric Field).

In addition, in the case of 2 × 10 ³ Ω / □ or less and 1 × 10 ⁶ Ω or less, or 6 × 10 ³ Ω / □ or less and 4 × 10 ³ Ω or less, respectively, the ELEF of the MPR-2 guideline, Both VLEF can be achieved.

Alternatively, in the case of 5 × 10 ⁴ Ω / □ or less and 4 × 10 ³ Ω or less, respectively, the TCO guideline ELEF can be achieved.

  Furthermore, the present invention has two transparent substrates sandwiching a liquid crystal layer, has a polarizing plate on the surface of the transparent substrate on the surface side of the two transparent substrates, A layer having a connection electrode in a region outside the effective display region on the front surface side of the transparent substrate on the back surface side, the sheet resistance of at least one of the constituent layers of the polarizing plate being not more than a certain value, and the conductive layer Has an insulating layer having an anti-reflection function on the front surface thereof, and electrically connects the conductive layer and the connection electrode via the insulating layer with a conductive connection material. The connection resistance of the electrical connection is set to a certain value or less.

  Thus, in the image display device having the polarizing plate on the surface, the unnecessary emission field can be reduced to a level that satisfies the values of the various guidelines.

The values to be achieved for the sheet resistance and the connection resistance of at least one of the constituent layers of the polarizing plate differ according to the above guidelines. As will be described in detail in Examples, when the sheet resistance and the connection resistance of one layer are respectively 2 × 10 ³ Ω / □ or less and 4 × 10 ³ Ω or less, both the ELF and the VLEF of the TCO guidelines are achieved. I can do it.

Further, the sheet resistance and the connection resistance of the one layer are set to 2 × 10 ³ Ω / □ or less and 1 × 10 ⁶ Ω or less, or 6 × 10 ³ Ω / □ or less and 4 × 10 ³ Ω or less, respectively. In such a case, both the ELF and the VLEF of the MPR guidelines can be achieved.

Alternatively, when the sheet resistance and the connection resistance of the single layer are set to 5 × 10 ⁴ Ω / □ or less and 4 × 10 ³ Ω or less, the TEF guideline ELEF can be achieved.

  Further, the present invention provides a substrate having two transparent substrates sandwiching a liquid crystal layer, having a polarizing plate on the surface of the transparent substrate on the front side of the two transparent substrates, and having an external connection terminal. The sheet resistance of at least one of the constituent layers of the polarizing plate is set to a predetermined value or less, and an insulating layer having an antireflection function is provided on the front surface of the conductive layer, and the conductive layer has the conductive property. The layer and the external connection terminal are electrically connected to each other with a conductive connection material via the insulating layer, and a connection resistance of the electrical connection is set to a certain value or less.

Thereby, in the image display device having the polarizing plate on the surface, the unnecessary emission field can be reduced to a level that satisfies the values of the various guidelines.
Here, the values to be achieved for the sheet resistance and the connection resistance of at least one of the constituent layers of the polarizing plate also differ depending on the guideline. Similarly, as will be described in detail in Examples, when the sheet resistance and the connection resistance of one layer are set to 2 × 10 ³ Ω / □ or less and 4 × 10 ³ Ω or less, respectively, the TCO guidelines ELEF and VLEF Both can be achieved.

Further, the sheet resistance and the connection resistance of the one layer are set to 2 × 10 ³ Ω / □ or less and 1 × 10 ⁶ Ω or less, or 6 × 10 ³ Ω / □ or less and 4 × 10 ³ Ω or less, respectively. In this case, both the ELF and the VLEF of the MPR-2 guideline can be achieved.

Alternatively, when the sheet resistance and the connection resistance of the single layer are set to 5 × 10 ⁴ Ω / □ or less and 4 × 10 ³ Ω or less, the TCO guideline ELEF can be achieved.

  Furthermore, the present invention has a polarizing plate on the surface, a conductive film is formed on the surface of the polarizing plate so as to cover the display area, the sheet resistance of the conductive film is set to a certain value or less, and the conductive film Has an area covering the frame formed outside the display area.

  Thus, in the image display device having the polarizing plate on the surface, the unnecessary emission field can be reduced to a level that satisfies the values of the various guidelines.

When the conductive film has a region covering the frame formed outside the display region, the connection resistance between the conductive film and the frame can be regarded as substantially zero. Therefore, when the sheet resistance of the conductive film is 2 × 10 ³ Ω / □ or less, both of the ELF and the VLEF of the TCO guidelines can be achieved.

When the density is 2 × 10 ³ Ω / □ or less, or 6 × 10 ³ Ω / □ or less, both the ELEF and the VLEF of the MPR-2 guideline can be achieved.

Alternatively, in the case of 5 × 10 ⁴ Ω / □ or less, it is possible to achieve the TEF guideline ELEF.

  Furthermore, the present invention has two transparent substrates sandwiching a liquid crystal layer, has a polarizing plate on the surface of the transparent substrate on the surface side of the two transparent substrates, It has a connection electrode in an area outside the display area on the front side of the substrate on the back side, has a conductive film covering the display area on the surface of the polarizing plate, and has a constant sheet resistance of the conductive film. And a part of the conductive film has a region covering the connection electrode.

  When the conductive film has a region covering the connection electrode, the connection resistance between the conductive film and the connection electrode can be regarded as substantially zero, and an antistatic effect and a leakage electric field reduction effect can be obtained. Can be done.

  Furthermore, the present invention has two transparent substrates sandwiching a liquid crystal layer, has a polarizing plate on the surface of the transparent substrate on the surface side of the two transparent substrates, It has a connection electrode in an area outside the display area on the front side of the substrate on the back side, has a conductive film covering the display area on the surface of the polarizing plate, and has a constant sheet resistance of the conductive film. Value or less, and the conductive film is electrically connected to the connection electrode by a material having conductivity.

  Thereby, by appropriately setting the sheet resistance of the conductive film and the connection resistance of the connection electrode, an antistatic effect and a leakage electric field reduction effect can be obtained.

  Further, the present invention provides a substrate having two transparent substrates sandwiching a liquid crystal layer, having a polarizing plate on the surface of the transparent substrate on the front side of the two transparent substrates, and having an external connection terminal. Having a conductive film covering the display area on the surface of the polarizing plate, making the sheet resistance of the conductive film a certain value or less, and the conductive film has conductivity with the external connection terminal. It is characterized by being electrically connected by a material having the same.

  Thereby, by appropriately setting the sheet resistance of the conductive film and the connection resistance of the connection electrode, an antistatic effect and a leakage electric field reduction effect can be obtained.

  Further, the present invention has a polarizing plate on the surface, at least one of the constituent layers of the polarizing plate has conductivity, the sheet resistance of the conductive layer is less than a certain value, the conductivity of the polarizing plate An insulating layer having an anti-reflection function is formed on the entire surface except for at least a part of the display area, and the insulating layer having an anti-reflection function is not formed on the front surface of the layer having the anti-reflection function. At least a part of the region outside the display region and the metal frame formed outside the display region are electrically connected by a conductive connection material, and the connection resistance of the electric connection is set to a certain value or less. It is characterized by the following.

  Thereby, in the image display device having the polarizing plate on the surface, the unnecessary emission field can be reduced to a level that satisfies the values of the various guidelines.

As described above, the values to be achieved for the sheet resistance and the connection resistance of at least one of the constituent layers of the polarizing plate differ depending on the guideline. As will be described in detail in Examples, when the sheet resistance and the connection resistance of one layer are respectively 2 × 10 ³ Ω / □ or less and 4 × 10 ³ Ω or less, both of the ELF and the VLEF of the TCO guideline are achieved. can do.

In addition, in the case of 2 × 10 ³ Ω / □ or less and 1 × 10 ⁶ Ω or less, or 6 × 10 ³ Ω / □ or less and 4 × 10 ³ Ω or less, respectively, the ELEF of the MPR-2 guideline is used. , VLEF can be achieved.

Alternatively, in the case of 5 × 10 ⁴ Ω / □ or less and 4 × 10 ³ Ω or less, respectively, the TCO guideline ELEF can be achieved.

  Furthermore, the present invention has two transparent substrates sandwiching a liquid crystal layer, has a polarizing plate on the surface of the transparent substrate on the surface side of the two transparent substrates, A connection electrode is provided in a region other than the display region on the front surface side of the back surface side substrate, at least one of the constituent layers of the polarizing plate has conductivity, and the sheet resistance of the conductive layer is equal to or less than a certain value. On the front surface of the conductive layer of the polarizing plate, an insulating layer having an antireflection function is formed on the entire surface except at least a part of the region outside the display region, and has the antireflection function. At least a part of the region other than the display region where the insulating layer is not formed and the connection electrode are electrically connected with a conductive connection material, and the connection resistance of the electrical connection is equal to or less than a certain value. It is characterized by the following.

  Thus, in the image display device having the polarizing plate on the surface, the unnecessary emission field can be reduced to a level that satisfies the values of the various guidelines.

As described above, the values to be achieved for the sheet resistance and the connection resistance of at least one of the constituent layers of the polarizing plate differ depending on the guideline. As will be described in detail in Examples, when the sheet resistance and the connection resistance of one layer are respectively 2 × 10 ³ Ω / □ or less and 4 × 10 ³ Ω or less, both of the ELF and the VLEF of the TCO guideline are achieved. can do.

In addition, in the case of 2 × 10 ³ Ω / □ or less and 1 × 10 ⁶ Ω or less, or 6 × 10 ³ Ω / □ or less and 4 × 10 ³ Ω or less, respectively, the ELEF of the MPR-2 guideline is used. , VLEF can be achieved.

Alternatively, when each is set to 5 × 10 ⁴ Ω / □ or less and 4 × 10 ³ Ω or less, the TCO guideline ELEF can be achieved.

  Further, the present invention includes a substrate having a polarizing plate on its surface and having terminals for external connection, at least one of the constituent layers of the polarizing plate has a sheet resistance of a certain value or less, and the conductivity of the polarizing plate An insulating layer having an anti-reflection function is formed on the entire surface except for at least a part of the display region outside the display layer, and the insulating layer having an anti-reflection function is formed. At least a part of the area outside the display area and the external connection terminal are electrically connected by a conductive connection material, and the connection resistance of the electrical connection is set to a certain value or less. .

  Thereby, in the image display device having the polarizing plate on the surface, the unnecessary emission field can be reduced to a level that satisfies the values of the various guidelines.

As described above, the values to be achieved for the sheet resistance and the connection resistance of at least one of the constituent layers of the polarizing plate differ depending on the guideline. As will be described in detail in Examples, when the sheet resistance and the connection resistance of one layer are respectively 2 × 10 ³ Ω / □ or less and 4 × 10 ³ Ω or less, both of the ELF and the VLEF of the TCO guideline are achieved. can do.

In addition, in the case of 2 × 10 ³ Ω / □ or less and 1 × 10 ⁶ Ω or less, or 6 × 10 ³ Ω / □ or less and 4 × 10 ³ Ω or less, respectively, the ELEF of the MPR-2 guideline is used. , VLEF can be achieved.

Alternatively, in the case of 5 × 10 ⁴ Ω / □ or less and 4 × 10 ³ Ω or less, respectively, the TCO guideline ELEF can be achieved.

  Furthermore, the present invention has two transparent substrates sandwiching a liquid crystal layer, has a conductive layer on the surface side of the two transparent substrates, and reduces the sheet resistance of the conductive layer to a certain value or less. The display region on the conductive layer has a polarizing plate, a metal frame formed outside the conductive layer and the display region, electrically connected by a conductive connection material, The connection resistance of the connection is set to a certain value or less.

  Thus, in the image display device having the polarizing plate on the surface, the unnecessary emission field can be reduced to a level that satisfies the values of the various guidelines.

Similarly, the values to be achieved for the sheet resistance and connection resistance of the conductive layer on the surface of the transparent substrate differ depending on the guideline. As will be described in detail in Examples, when the sheet resistance and the connection resistance of the conductive layer on the surface of the transparent substrate are set to 2 × 10 ³ Ω / □ or less and 4 × 10 ³ Ω or less, respectively, the TCO guideline ELEF, VLEF Can achieve both.

In addition, in the case of 2 × 10 ³ Ω / □ or less and 1 × 10 ⁶ Ω or less, or 6 × 10 ³ Ω / □ or less and 4 × 10 ³ Ω or less, respectively, the ELEF of the MPR-2 guideline is used. , VLEF can be achieved.

Alternatively, when each is set to 5 × 10 ⁴ Ω / □ or less and 4 × 10 ³ Ω or less, the TCO guideline ELEF can be achieved.

  Furthermore, the present invention has two transparent substrates sandwiching a liquid crystal layer, has a conductive layer on the surface side of the two transparent substrates, and reduces the sheet resistance of the conductive layer to a certain value or less. A polarizing plate in a display region on the conductive layer, a connection electrode in a region outside the display region on the front surface of the back substrate of the two transparent substrates, and a connection electrode; And the connection electrode are electrically connected to each other outside the display region by a conductive connection material, and a connection resistance of the connection is set to a predetermined value or less.

  Thereby, in the image display device having the polarizing plate on the surface, the unnecessary emission field can be reduced to a level that satisfies the values of the various guidelines.

Similarly, the values to be achieved for the sheet resistance and connection resistance of the conductive layer on the surface of the transparent substrate differ depending on the guideline. As will be described in detail in Examples, when the sheet resistance and the connection resistance of the conductive layer on the surface of the transparent substrate are set to 2 × 10 ³ Ω / □ or less and 4 × 10 ³ Ω or less, respectively, the TCO guideline ELEF, VLEF Can achieve both.

In addition, in the case of 2 × 10 ³ Ω / □ or less and 1 × 10 ⁶ Ω or less, or 6 × 10 ³ Ω / □ or less and 4 × 10 ³ Ω or less, respectively, the ELEF of the MPR-2 guideline is used. , VLEF can be achieved.

Alternatively, when each is set to 5 × 10 ⁴ Ω / □ or less and 4 × 10 ³ Ω or less, the TCO guideline ELEF can be achieved.

  Furthermore, the present invention has two transparent substrates sandwiching a liquid crystal layer, has a conductive layer on the surface side of the two transparent substrates, and reduces the sheet resistance of the conductive layer to a certain value or less. And a substrate having an external connection terminal, a display region on the conductive layer has a polarizing plate, and the conductive layer and the external connection terminal are outside the display region by a conductive connection material. It is electrically connected, and the connection resistance of the connection is set to a certain value or less.

  Thus, in the image display device having the polarizing plate on the surface, the unnecessary emission field can be reduced to a level that satisfies the values of the various guidelines.

Similarly, the values to be achieved for the sheet resistance and connection resistance of the conductive layer on the surface of the transparent substrate differ depending on the guideline. As will be described in detail in Examples, when the sheet resistance and the connection resistance of the conductive layer on the surface of the transparent substrate are set to 2 × 10 ³ Ω / □ or less and 4 × 10 ³ Ω or less, respectively, the TCO guideline ELEF, VLEF Can achieve both.

In addition, in the case of 2 × 10 ³ Ω / □ or less and 1 × 10 ⁶ Ω or less, or 6 × 10 ³ Ω / □ or less and 4 × 10 ³ Ω or less, respectively, the ELEF of the MPR-2 guideline is used. , VLEF can be achieved.

Alternatively, when each is set to 5 × 10 ⁴ Ω / □ or less and 4 × 10 ³ Ω or less, the TCO guideline ELEF can be achieved.

  Furthermore, the present invention relating to the formation of the connection electrode described above is directed to an image display device in which a signal wiring for transmitting a signal is formed on the front surface side of the back side substrate of the two transparent substrates via the liquid crystal layer. By forming it at the terminal portion of the signal wiring, it can be realized without increasing the number of steps.

  Further, the connection electrode is electrically connected to the external connection terminal by a connection wiring formed in the same layer as the signal wiring, so that electrical connection can be realized without increasing the number of steps.

  Further, in the present invention relating to the formation of the connection electrode described above, the video signal wiring and the scanning signal wiring are formed on the front surface side of the back side substrate of the two transparent substrates with the liquid crystal layer interposed therebetween. In an image display device in which each of the pixels of the image display device is constituted by a matrix-shaped region surrounded by a scanning signal line and an external connection terminal, a terminal portion of the video signal line or the scanning signal line is formed. Therefore, it can be realized without increasing the number of steps.

  Further, the connection electrode is electrically connected to the external connection terminal by a connection wiring formed in the same layer as the video signal wiring or the scanning signal wiring, so that the electrical connection can be performed without increasing the number of processes. realizable.

  Furthermore, in the present invention, the video signal wiring, the scanning signal wiring, and the connection wiring are covered with an insulating protective film in a region other than the terminal portion, the connection electrode, and the external connection terminal. It is possible to prevent a short circuit with another electrode from occurring when the connection electrode is electrically connected.

  Further, according to the present invention, the potential on the display surface can be kept constant by applying a DC voltage to the above-mentioned external connection terminal, so that the effect of reducing the leakage electric field can be realized. The DC voltage in this case also includes the ground potential level.

  Further, the present invention applies an AC voltage having a component having a phase opposite to that of a leakage electric field radiated from the surface of the image display device to the external connection terminal, thereby reducing a leakage electric field component induced on the display surface. Since it has the effect of canceling, the effect of reducing the leakage electric field can be realized.

Further, the conductive layer can be realized by including at least one of ITO, SnO ₂ , In ₂ O ₃ , and Sb ₂ O ₃ .

Further, the conductive film can be realized by including at least one of ITO, SnO ₂ , In ₂ O ₃ , and Sb ₂ O ₃ .

Further, the conductive film can be realized by an SnO ₂ film in which beads having conductivity are dispersed. In this case, the surface can simultaneously achieve the antireflection effect.

Further, the conductive layer can be realized by including at least one of ITO, SnO ₂ , In ₂ O ₃ , and Sb ₂ O ₃ .

  Further, a conductive rubber member can be used as the conductive connection material.

  This conductive rubber member can be realized by a material having a layer of silicone rubber containing a conductive filler. Further, it can be realized by a material having a layer of a silicone rubber containing carbon. Furthermore, it can be realized by a material containing fine particles of any one of Au, Ag, Cu, Co, Ni and Sn or an alloy. Alternatively, it can be realized by rubber in which a metal foil is laminated on the surface.

  Furthermore, as the conductive connection material, a plastic member wound with a metal foil can be used.

  Further, the conductive connection material may be added to a so-called metal solder containing at least one of Au, Ag, Cu, Co, Ni, Sn, and Pb or an alloy when bonding with a glass surface. It can be realized by a so-called ultrasonic solder containing ceramics.

  Furthermore, the conductive connection material can be realized by a resin containing at least any one of Au, Ag, Cu, Co, Ni, Sn, and Pb or an alloy. As a typical example, there is a so-called silver paste, which is liquid at the time of work and solid after drying, so that both workability and conductivity can be realized.

  Further, the conductive connection material can be realized by using a metal wiring. This metal wiring can be fixed with solder containing at least one of Au, Ag, Cu, Co, Ni, Sn, and Pb. The metal wiring may be either a bare wire or a covered wire.

  Further, the conductive connection material can be realized using a metal foil tape.

  Furthermore, a polarizing plate in which an insulating layer having an anti-reflection function is formed on the entire surface except for at least a part of the region outside the display region on the front surface of the conductive layer has a polarizing layer, In addition, a sheet having a conductive layer formed on the outermost surface and a sheet having an insulating property, an anti-reflection function, and a partly perforated area are manufactured by integrating the sheet. can do.

  In addition, a sheet having a partly perforated region or an integrated polarizing plate having the above-described feature is cut so that the perforated region becomes at least a part of an end portion of the polarizing plate. Thereby, the conductive layer can be exposed at the end of the polarizing plate, and in this case, the connection resistance can be reduced.

  According to the present invention, it is possible to provide a high-quality liquid crystal display device in which the static electricity on the screen of the liquid crystal display device is prevented and the radiation of the leakage electromagnetic wave is suppressed below various guidelines.

Hereinafter, the present invention will be described in detail with reference to examples in which the embodiments are applied to a liquid crystal display device.
[Example 1]

  FIG. 1 is a sectional view of a liquid crystal display device for explaining a first embodiment of the present invention, wherein 1 is a liquid crystal display element, 2 is a polarizing plate on the surface of the liquid crystal display element, 3 is a rubber for connection, and 4 is a metal frame. Reference numeral 5 denotes a polarizing plate on the back surface of the liquid crystal display element, 6 denotes a backlight unit, and 7 denotes a printed circuit board.

  FIG. 2 is a cross-sectional view showing the structure of the polarizing plate on the surface of the liquid crystal display element. This polarizing plate has a three-layer structure, 2A is a polarizing layer, 2B is a conductive layer, and 2C is an antireflection layer. . The connection between the polarizing plate 2, the frame 4, and the rubber 3 for connection was fixed by a double-sided adhesive tape formed on both sides of the rubber 3.

The layer 2B having conductivity is an ITO film formed by a sputtering method. Further, in order to protect the conductive layer 2B and improve the reliability with respect to aging, a thin film of SiO ₂ was laminated on the surface of the ITO layer 2B by a three-layer sputtering method. The SiO ₂ film formed by this sputtering method also serves as the antireflection layer 2C at the same time, and in this embodiment, becomes an AR layer (anti-reflection layer).

The antistatic effect of the surface of the polarizing plate 2 depends on the sheet resistance of the conductive layer 2B. A liquid crystal display device has a very low possibility of high voltage charging like a cathode ray tube. For this reason, it has been confirmed that dust adhesion does not pose a problem if the sheet resistance is about 10 ¹⁴ Ω / □ or less in practical use.

Since the ITO film 2B formed by the sputtering method has a very low resistance, a sheet resistance of 1 × 10 ³ Ω / □ or less can be easily realized with a thin film having a thickness of about 100 nm. In this example, a sheet resistance of 5 × 10 ² Ω / □ was realized at a film thickness of 100 nm. Thus, in this embodiment, an antistatic effect can be realized in an image display device having a polarizing plate.
[Example 2]

  In the present embodiment, a conductive rubber was used as the connection rubber 3 of the first embodiment. Therefore, in FIG. 1, the conductive layer 2 </ b> B of the polarizing plate 2 is electrically connected to the metal frame 4 by the conductive rubber 3. As the conductive rubber, for example, SE6770U (trade name, manufactured by Toray Dow Silicone Co., Ltd.) can be used.

Thereby, the electric charge charged in the conductive layer 2 </ b> B escapes to the frame 4 via the conductive rubber 3. Therefore, the antistatic effect is larger than in the first embodiment.
[Example 3]

  One of the main objects of the present invention is to realize a reduction in leakage electric field (EMI) in an image display device having a polarizing plate. In an image display device having a polarizing plate, the leakage electric field from other than the display surface can be reduced as shown in FIG.

  FIG. 3 is a cross-sectional view for explaining a structure for reducing the leakage electric field of the liquid crystal display device, where 4 is a metallic housing (corresponding to the metal frame in FIG. 1), 8 is a display area of the image display device, 9 is a monitor circuit. Usually, in order to improve the appearance quality (appearance), the metallic housing 4 is further covered with a plastic decorative case on the outside thereof. However, the reduction of the leakage electric field from other than the display surface itself is performed by the metallic housing. It is obtained by lowering the body 4 to ground potential.

  On the other hand, in order to reduce the leakage electric field from the display surface, the method of covering the display surface with the opaque metallic housing 4 as described above cannot be adopted because the display surface must be exposed.

  Therefore, the leakage electric field from the display surface can be reduced by forming a conductive layer with a so-called transparent conductor and making this conductive layer electrically constant potential, or by applying an AC voltage with a phase that cancels the leakage electric field. Must be done by

  Thus, in the present embodiment, the same configuration as in the second embodiment is used to reduce the leakage electric field from the display surface.

A plurality of guidelines are indicated as levels required for the reduction of the leakage electric field. In particular, as typical examples, MPR-2 (Staten Match Provrad: Swedish National Metrology and Testing Council Guideline) and TCO (Tjanslemennens Central Organization: Swedish Labor Organization Guideline) are known. Therefore, it is necessary to achieve these guidelines particularly from the viewpoint of health and safety of the user of the image display device.
Table 1 shows MPR-2 and TCO guidelines.

  In Table 1, BAND-1 is called ELEF (Extremely Low Frequency Electric Field) and is a guideline at 5 Hz to 2 kHz. BAND-2 is referred to as VLEF (very low frequency electric field) and is a guideline at 2 kHz to 400 kHz. Although the measurement position is slightly different between MPR-2 and TCO, considering that the leakage electromagnetic field strength decreases with distance, it is desirable that any of the guidelines satisfies the measurement position at 30 cm.

  Next, in order to satisfy these guidelines, it is essential to clarify the configuration and specifications that can achieve them.

  Therefore, the present inventors conducted the following experiment to clarify the specifications.

FIG. 4 is a configuration diagram of an experimental system for measuring the intensity of a leaked electromagnetic field, where 100 is a liquid crystal display device, 101 is an electric field measuring device, and 102 is a signal generator.
An electric field measuring device 101 was installed at a position 30 cm in front of the liquid crystal display device 100, and a driving signal was input to the liquid crystal display device 100 from a signal generator 102. Normally, the liquid crystal display device 100 obtains a display image by transmitting light from a backlight. For this reason, an inverter circuit for supplying power to the backlight is built in, and the leakage electric field from this inverter circuit poses a serious problem. However, since this inverter circuit is arranged separately from the display surface, it is possible to take measures against the leakage electric field by means such as shielding by the metal plate (metal frame) described in FIG. Therefore, it can be considered separately from the countermeasures against the leakage electric field from the display surface.

  Since the object of the present invention is to suppress the leakage electric field from the display surface, a series of experiments were performed with the inverter turned off.

FIG. 5 is a sectional view of the liquid crystal display device used in the experimental system shown in FIG. The conductive layer 104 was formed directly on the liquid crystal display element 1. As the conductive layer 104, an ITO film was formed by a sputtering method. An SiO ₂ film 105 having a thickness of 500 nm was formed thereon except for a 1 cm square region. The conductive layer 104 and the metal frame 4 were electrically connected via the resistance element 107. The mechanical connection between the frame 4 and the liquid crystal display element 1 was made with a double-sided adhesive tape formed on both sides of the insulating spacer 106. The sheet resistance of the conductive layer was evaluated for its dependency by preparing a sample in which the thickness of the ITO film was changed.

  In addition, the influence of the connection resistance between the conductive layer and the constant potential surface was evaluated by changing the resistance value of the resistance element 107. As the liquid crystal display element 1, a so-called horizontal electric field type liquid crystal display element was used. This is for the following reason.

  That is, as disclosed by the present inventors in the already filed application, a so-called in-plane switching type liquid crystal display element is the only exceptional image display device using a polarizing plate, and a display image is generated by external static electricity. It has the property of being easily affected. Conversely, this means that the electric field generated by the operation inside the liquid crystal display element easily leaks to the outside. Therefore, in an image display device using a polarizing plate, it is considered that the device is most likely to generate a leakage electric field.

  In a so-called vertical electric field type liquid crystal display element, a transparent conductor film is formed as a stripe-shaped or solid film-forming electrode on the liquid crystal layer side of a transparent substrate on the display surface side as an electrode involved in display. Therefore, in a vertical electric field type liquid crystal display device, in a liquid crystal display device in which a transparent conductive film is formed in a stripe shape, voltages of opposite polarities are applied to adjacent transparent conductor films, and a transparent conductive film is applied to a solid film. In a liquid crystal display device having a film formed thereon, a stray electric field can be canceled or eliminated by applying a constant voltage, preferably a voltage of 0 V, if possible.

  Therefore, in a so-called vertical electric field type liquid crystal display element, there is room for reduction of a leakage electric field due to driving contrivance. However, in a horizontal electric field type liquid crystal display element, an electrode or a transparent conductor cannot be formed on the entire surface in the liquid crystal layer due to its operation principle as described above. Therefore, compared to a so-called vertical electric field type liquid crystal display element, the area that cannot be electrically shielded in the pixel is increased, that is, the room for reducing the leakage electric field by contriving the driving is limited.

  From this point of view, the so-called in-plane switching mode liquid crystal display element can be regarded as a sample for assuming the worst case with respect to the leakage electric field from the display surface of the image display device using the polarizing plate. It is.

In this experiment, a liquid crystal display element having the same configuration as a liquid crystal display element 1 having a nominal diagonal size of 13.3 inches and a resolution of 13.3 ”super TFT liquid crystal of XGA (product name, product code: TX34D11VC0FAAA) was used. No polarizing plate was attached to the surface, and a transparent substrate having an ITO layer and a SiO ₂ layer sequentially laminated as described above was used as the substrate on the front side. Display was performed using blue, black, dot checkerboard, horizontal line stripes (white and black), and vertical line stripes (white and black), and the maximum observed leakage electric field value was used as the observed leakage electric field value of the sample.

  6, 7 and 8 show the evaluation results.

FIG. 6 is a characteristic diagram showing the connection resistance dependence of VLEF and ELEF in a sample in which the sheet resistance of the conductive layer is 2 × 10 ³ Ω / □.

From the figure, it is clear that when the sheet resistance is 2 × 10 ³ Ω / □ or less, the MPR-2 guideline can be satisfied if the connection resistance is 1 × 10 ⁶ Ω or less.

  FIG. 7 is a characteristic diagram showing an enlarged evaluation result in a region where the connection resistance is low in FIG.

It is clear from the figure that when the sheet resistance is 2 × 10 ³ Ω / □ or less, the TCO guidelines can be satisfied if the connection resistance is 4 × 10 ³ Ω or less.

FIG. 8 is a characteristic diagram showing the sheet resistance dependence of VLEF and ELEF in a sample having a connection resistance of 4 × 10 ³ Ω.

When the sheet resistance of the conductive layer was 6 × 10 ³ Ω / □ or less, it was found that the MPR-2 guidelines could be satisfied. It was also found that when the sheet resistance of the conductive layer was 5 × 10 ⁴ Ω / □ or less, at least ELEF of the TCO guidelines could be satisfied.

  As described above, in a liquid crystal display device having a polarizing plate, in the case of a liquid crystal display element of a lateral electric field type, it is considered that the leakage electric field amount leaked from the display surface after taking various measures is maximized. There has been no report on systematic investigation of the relationship between the amount of leakage electric field and the sheet resistance and connection resistance using a so-called in-plane switching type liquid crystal display device. Accordingly, the conditions described with reference to FIGS. 6 to 8 are indispensable for reducing the leakage electric field from the display surface to a level satisfying the MPR-2 guidelines or the TCO guidelines in the image display device having the polarizing plate. It is thought that it was the level that became clear for the first time.

Therefore, in the present invention, a measure against the leakage electric field was taken by optimizing the sheet resistance of the conductive layer and the connection resistance between the conductive layer and the frame based on the above results.
That is, in Example 3, as in Example 1, a polarizing plate having a three-layer structure was used as the polarizing plate 2 as in Example 1. In FIG. 2, 2A is a polarizing layer, 2B is a layer having conductivity, and 2C is an antireflection layer. Then, an ITO film having a thickness of 100 nm was formed as the conductive layer 2B by a sputtering method, and a sheet resistance of 1 × 10 ³ Ω / □ or less was realized. Also, a 10 nm SiO ₂ thin film was formed as the antireflection layer 2C.

  Electrical connection with the metallic housing (frame 4) was made by the conductive rubber 3 as in the second embodiment.

FIG. 9 is a cross-sectional view illustrating an example of the structure of a conductive rubber, in which 10 is a rubber layer, and 11 is a conductive filler. Rubber 10 containing conductive filler 11 was used as conductive rubber 3. Thus, the electrical connection resistance between the conductive layer 2B and the metallic housing 4 (corresponding to the frame 4 in FIG. 1) was reduced to 4 × 10 ³ Ω or less. As a result, both the TCO and MPR-2 guidelines could be achieved.
[Example 4]

FIG. 10 is a cross-sectional view illustrating another example of the structure of the conductive rubber, in which 10 is a rubber layer, and 11A is carbon particles as a conductive filler. In the present embodiment, a rubber containing carbon particles 11A was used as the conductive rubber 3 of the third embodiment. Thereby, the same effect as that of the third embodiment can be realized.
[Example 5]

  FIG. 11 is a cross-sectional view illustrating another example of the structure of the conductive rubber, in which 10 is a rubber layer, and 11B is fine particles of Cu.

In the present embodiment, a rubber layer 10 mixed with Cu fine particles 11B was used as the conductive rubber 3 of the third embodiment. Thereby, the resistance value of the conductive rubber could be further reduced. The same effect can be obtained by mixing fine particles of any one of Au, Au, Cu, Co, Ni, and Sn or alloys instead of the fine particles of Cu.
[Example 6]

  FIG. 12 is a cross-sectional view illustrating still another example of the structure of the conductive rubber, in which 10 is a rubber layer, 11C is a metal foil, and 11D is a double-sided tape.

In this embodiment, a rubber 10 having a metal foil 11C laminated on the surface thereof is used as the conductive rubber 3 of the third embodiment, and a double-sided tape 11D is attached to both surfaces thereof. Thereby, the same effect as that of the third embodiment can be realized.
[Example 7]

  FIG. 13 is a cross-sectional view illustrating still another example of the structure of the conductive rubber, in which 10 is a rubber, 11A is a carbon particle, 11C is a metal foil, and 11D is a double-sided tape.

In this embodiment, as the conductive rubber 3 of the third embodiment, a rubber 10 having a metal foil 11C laminated on the surface and containing carbon particles 11A was used. Thereby, the same effect as that of the third embodiment can be realized.
Example 8

  FIG. 14 is a cross-sectional view of a main part of the liquid crystal display device of the present embodiment, and FIG. 15 is a schematic plan view thereof.

  In this embodiment, the conductive layer 2B and the metallic housing 4 (corresponding to the frame 4 in FIG. 1) are electrically connected by solder 14 instead of the conductive rubber of the third embodiment.

  That is, a part of the metallic housing 4 was bent toward the polarizing plate 2, and the housing 4 and the polarizing plate 2 were connected by the solder 14. Thereby, the connection resistance can be further reduced as compared with the case where the conductive rubber is used, and the level of the leakage electric field can be further reduced.

Further, as the solder material used in the present embodiment, any material containing any of Au, Ag, Cu, Co, Ni, Sn, and Pb may be used, and an ultrasonic solder (Cerasolzer) may be used. Good.
[Example 9]

  FIG. 16 is a cross-sectional view of a main part of the liquid crystal display device of the present embodiment. In this embodiment, the conductive layer 2B and the metallic housing 4 are formed by silver paste 15 instead of the solder 14 of the eighth embodiment. Electrical connection resistance. The silver paste 15 becomes liquid at the time of work and solid at the time of completion, so that workability can be improved.

In this embodiment, any of Au, Ag, Cu, Co, Ni, Sn, and Pb is contained in the resin, and any material may be used as long as it is a solid when completed.
[Example 10]

FIG. 17 is a cross-sectional view of a main part of the liquid crystal display device of the present embodiment. In the present embodiment, connection is made by metal wiring 16 as shown in FIG. After the polarizing plate 2 is stretched over the liquid crystal display element 1, one end of the metal wiring 16 is fixed to the surface of the polarizing plate 2 with solder 14. Next, the frame (metallic housing) 4 and the liquid crystal display element 1 are integrated using the spacer 106. Finally, a part of the side surface of the frame 4 was bent inward, and the other end of the metal wiring 16 and the bent portion were soldered with solder 14. Thereby, an effect equivalent to that of the third embodiment can be realized.
[Example 11]

  FIG. 18 is a cross-sectional view of a main part of the liquid crystal display device of the present embodiment. In this embodiment, connection is made by a metal foil tape 17 as shown in FIG. . After the polarizing plate 2 and the polarizing plate 5 (the polarizing plate on the back side) are bonded to the liquid crystal display element 1, a part of the metal foil tape 17 is attached to the surface of the polarizing plate 2 with a double-sided adhesive tape.

  Next, the liquid crystal display element 1 and the frame 4 on which the spacer 106 has been previously stretched are integrated. At this time, one end of the metal foil tape 17 is pressed against the polarizing plate 2 by the spacer 106.

Next, the backlight unit 6 in which the spacers 18 have been formed in advance is combined with the frame 4 and the liquid crystal display element 1. At this time, the other end of the metal foil tape 17 is pressed against the frame 4 by the spacer 18. Thus, the polarizing plate 2, the frame 4, and the metal foil tape 17 are fixed, and the same effect as that of the third embodiment can be realized.
[Example 12]

  FIG. 19 is a cross-sectional view illustrating an example of a connecting member interposed between the frame and the liquid crystal display element. In this embodiment, instead of the conductive rubber of the third embodiment, a plastic 21A is used as shown in FIG. A plastic member 21 having a metal foil 21B laminated on the surface thereof was used. 21C is a double-sided tape.

  FIG. 20 is a perspective plan view showing a method of fixing the frame 4 and the polarizing plate in the liquid crystal display device of this embodiment.

  The double-sided adhesive tape formed on the surface of the rubber spacer 22 plays a role of fixing. The plastic members 21 with the metal foil laminated on the surface were arranged at four corners of the polarizing plate 2. At this time, it is desirable that the thickness of the plastic member 21 in which the metal foil is laminated on the surface is the same as or thinner than the rubber spacer 22.

FIG. 21 is a plan perspective view showing a modification of the fixing method of the frame 4 and the polarizing plate in the liquid crystal display device of this embodiment.
As shown in the figure, the plastic member 21 having a metal foil laminated on its surface can also serve to fix the frame 4 and the polarizing plate 2, and in this case, the contact resistance can be further reduced. Further, foamable plastic may be used as the plastic member 21A of the plastic member 21 in which the metal foil as shown in FIG. 19 is laminated on the surface. When this foamed plastic is used, the plastic member 21 itself having the metal foil laminated on the surface has elasticity, and can follow the deformation of the frame 4 well and maintain the electrical connection. The effect can be achieved.
[Example 13]
FIG. 22 is a cross-sectional view showing a method of fixing the frame 4 and the polarizing plate in the liquid crystal display device of this embodiment, wherein 1 is a liquid crystal display element, 1A is an upper substrate, 1B is a liquid crystal layer, 1C is a sealing material, 1D is a lower substrate, and 1E is a connection electrode. Reference numeral 2 denotes a polarizing plate (front side), 4 denotes a frame, 5 denotes a polarizing plate (back side), 14 denotes solder, and 22 denotes a rubber spacer.
As shown in FIG. 2, the polarizing plate 2 has a three-layer structure, 2A is a polarizing layer, 2B is a conductive layer, and 2C is an antireflection layer. The conductive layer 2B of the polarizing plate 2 is electrically connected to the connection electrode 1E formed on the lower substrate 1D by the solder 14 as shown in FIG.
FIG. 23 is a plan view showing the configuration of the lower substrate in the liquid crystal display device of this embodiment, in which video signal lines 40 and scanning signal lines 41 are formed in a matrix, and each of the matrix regions is an image display device. Are formed. The video signal line 40 and the scanning signal line 41 are electrically separated by an insulating layer 42.
The video signal line 40 and the scanning signal line 41 are connected to a video signal driving circuit and a scanning signal driving circuit (not shown) at a video signal line terminal 40B and a scanning signal line terminal 41B, respectively.
The connection electrode 1 </ b> E is formed in the same layer as the video signal line 40, and the connection wiring 44 also formed in the same layer as the video signal line 40 makes the external electrode formed close to the outside of the video signal line terminal portion 40 </ b> B. It is electrically connected to the connection terminal 43. The external connection terminal 43 is connected to the ground potential at the same time as the connection between the video signal line terminal portion and the video signal drive circuit. Thereby, the same effect as in the third embodiment can be obtained.
[Example 14]
This embodiment is different from the thirteenth embodiment in that the connection electrode 1E, the connection wiring 44, and the external connection terminal 43 are formed in the same layer as the scanning signal line 41. Thereby, the same effect as that of the thirteenth embodiment can be obtained.
[Example 15]
FIG. 24 is a cross-sectional view for explaining the main structure of the connection electrode portion of this embodiment. The difference between the present embodiment and the thirteenth embodiment is that, in the present embodiment, a protective film 45 is formed of SiN to cover the video signal line 40 and the scanning signal line 41, and the opposite side of the lower substrate 1D from the video signal line terminal portion. The point lies in that the protective film is removed on the connection electrode 1E formed in the region.
Thereby, in this embodiment, it is possible to prevent a short circuit from occurring between the video signal line or the scanning signal line when the connection electrode is connected to the conductive layer.
[Example 16]
FIG. 25 is a cross-sectional view for explaining the main structure of the connection electrode portion of this embodiment. In the present embodiment, the exposed region of the connection electrode 1E of Embodiment 15 was formed of ITO46. Thereby, the reliability of the connection electrode 1E can be improved.
[Example 17]
FIG. 26 is a schematic plan view illustrating the structure of the connection electrode portion of the present example. The difference between this embodiment and the thirteenth embodiment is that the connection electrode 1E is formed in any one of the four corners of the lower substrate 1D, and the connection electrode 1E is formed integrally with the external connection terminal 43. That is the point.
With this configuration, no connection wiring is required, and there is no intersection area with the video signal line 40 or the scanning signal line 41. Therefore, a defect due to a short circuit in this area can be eliminated.
[Example 18]
FIG. 27 is a cross-sectional view for explaining the configuration of the liquid crystal display device of this embodiment, wherein 1 is a liquid crystal display element, 2 is a polarizing plate (front side), 4 is a frame, and 22 is a rubber spacer. Reference numeral 47 denotes a conductive film, which is formed so as to cover at least the entire display region. When the conductive film 47 overlaps the frame 4, the conductive film 47 also serves as both the conductive layer 2B in the polarizing plate 2 and the conductive connection material in the first embodiment.
In the manufacture of the liquid crystal display device of the present embodiment, a conductive solution is coated on the polarizing plate 2 and the frame 4 and then left at 70 ° C. for 24 hours, so that SiO 2 is formed by a sol-gel reaction. _Two A thin film was formed.
Usually complete SiO _Two Although a higher temperature is used to form SiO, the use of a low temperature of about 70 ° C. _Two Since a large amount of unreacted alkoxyl groups remain in the thin film, ^Ten A conductivity of about Ω / mouth is realized, and an antistatic effect can be obtained.
In addition, ITO, SnO _Two , In _Two O _Three , Sb _Two O _Three When any of the fine particles is mixed, the resistance value of the conductive film 47 to be formed can be further reduced, so that the antistatic effect can be further improved.
Furthermore, the mixed solution serving as a raw material contains SiO 2. _Two When the fine particles are mixed, the formed conductive film 47 is made of SiO. _Two Fine particles are SiO _Two It is fixed in the membrane. In this case, SiO _Two Since the fine particles work as a scatterer, a so-called anti-glare effect can be obtained.
[Example 19]
In this embodiment, the conductive film 47 of the eighteenth embodiment is made of SiO. _Two An ITO film in which fine particles were dispersed was formed by a sol-gel method. Thus, the sheet resistance can be further reduced as compared with the eighteenth embodiment, and an effect on EMI countermeasures can be obtained.
Also, instead of the ITO film, SnO _Two Film and In _Two O _Three The same effect can be obtained by forming a film.
[Example 20]
FIG. 28 is a cross-sectional view of a main part of the configuration of the liquid crystal display device according to the present embodiment, where 1 is a liquid crystal display element, 1A is an upper substrate, 1B is a liquid crystal layer, 1C is a sealing material, 1D is a lower substrate, 1E is a connection electrode.
The configuration of the connection electrode 1E is the same as that of the thirteenth embodiment. Reference numeral 2 denotes a polarizing plate, 22 denotes a rubber spacer, 4 denotes a frame, and 47 denotes a conductive film similar to that of the eighteenth embodiment.
In the present embodiment, unlike the eighteenth embodiment, the conductive film 47 is formed to cover the connection electrode 1E formed on the lower substrate 1D. This eliminates the need to form the conductive film 47 on the frame 4 as in the eighteenth embodiment, so that the appearance quality can be improved as compared with the eighteenth embodiment.
[Example 21]
In the present embodiment, in order to protect the conductive layer 2B of the polarizing plate having a three-layer structure shown in FIG. _Two A film is formed. Therefore, the electrical connection between the conductive layer 2B and the metal frame 4 is made by the insulator SiO2. _Two Since the connection is performed through the film, there is a disadvantage that the value of the connection resistance increases.
As described in the third embodiment, it is desirable to reduce the connection resistance as much as possible in order to reduce EMI. Therefore, in the present embodiment, a polarizing plate having a structure in which the antireflection layer 2C is removed in a part of the region for making electrical connection is used.
FIG. 29 is a conceptual diagram of the polarizing plate used in this example as viewed obliquely, where 2A is a polarizing layer, and 2B is a conductive layer, which is formed on the entire surface. On the other hand, the antireflection layer 2C is not formed in some regions.
FIG. 30 is a cross-sectional view showing a mounting state of the polarizing plate in the present embodiment, where 1 is a liquid crystal display element, 2 is a polarizing plate (front side), 5 is a polarizing plate (back side), 4 is a metal frame, 48 is a conductive connecting material.
In this embodiment, the metal frame 4 and the conductive layer 2B are electrically connected to each other by the conductive connecting material 48 in a region where the conductive layer 2B in the polarizing plate 2 is exposed.
FIG. 31 is a plan view showing a mounting state of the polarizing plate in the present embodiment, in which electrical connection is achieved by a conductive connection material 48 outside the display area, and a double-sided adhesive tape formed on both surfaces of the cushion rubber 49. Adheres the polarizing plate 2 and the frame 4 to achieve mechanical connection strength. Thereby, the EMI reduction effect can be improved as compared with the case of the first embodiment.
FIG. 32 is an explanatory diagram of an example of a procedure for manufacturing a polarizing plate having a structure used in this example.
That is, first, (a) a layer 2C having conductivity is formed on the polarizing layer 2A. This can be formed, for example, by sputtering an ITO film, but a transparent conductor film may be formed by a coating method.
Next, (b) an AG process is performed on a sheet to be the antireflection layer 2C, for example, a TAG film, and holes are formed in at least one portion.
(C) The sheets prepared in the above (a) and (b) are laminated to form a polarizing plate sheet. As a result, a conductive layer is exposed in a region where a hole is formed in the antireflection layer 2C.
(D) The polarizing plate sheet of (c) is cut so as to cover the region with the hole, thereby completing the polarizing plate. (D) shows the completed polarizing plate.
By using the polarizing plate configured as described above, a liquid crystal display device having the structure of this embodiment can be realized. In FIG. 32, after a conductive layer is formed on the polarizing layer, SiO 2 is formed by mask sputtering. _Two By sputtering the film, the SiO _Two You may comprise the polarizing plate which has the area | region where a film is not formed.
Examples of the conductive conductive connecting material 48 include a rubber containing a conductive filler described in the third embodiment, a rubber containing carbon as in the fourth embodiment, and Au, Ag, and Cu as in the fifth embodiment. , Co, Ni, or Sn, a rubber in which fine particles of a single substance or an alloy are mixed, a rubber in which a metal foil is laminated on the surface in the same manner as in the sixth embodiment, and a metal foil in the same manner as in the seventh embodiment. Rubber containing carbon can also be used.
Also, as in the case of the eighth embodiment, a solder containing any of Au, Ag, Cu, Co, Ni, Sn, and Pb, an ultrasonic solder (Cerasolzer), and a silver paste as in the ninth embodiment can be used. good. Instead of the silver paste, a material that contains any of Au, Ag, Cu, Co, Ni, Sn, and Pb in the resin and becomes solid when completed may be used.
Further, a metal wiring 16 may be used as in the tenth embodiment, a metal foil tape 17 may be used as in the eleventh embodiment, and a plastic member 21 having a metal foil laminated on the surface may be used as in the thirteenth embodiment.
[Example 22]
The difference between the present embodiment and the twenty-first embodiment is that an electrical connection is made between the conductive layer 2b and the connection electrode 1E shown in the thirteenth embodiment. Thus, the same effect as that of the twenty-first embodiment can be obtained.
[Example 23]
FIG. 33 is a cross-sectional view of an essential part for explaining an electrical connection state of a polarizing plate in the liquid crystal display device of the present embodiment, and FIG. 34 is a plan view thereof. Is that electrical connection is made to the layer 2B having
34 and 35, an external connection terminal 43 is formed on a PCB (printed circuit board) 7 for supplying a control signal to the liquid crystal display element 1, and is provided between the conductive layer 2 B and the external connection terminal 43. The electrical connection is made by the coated metal wiring 16 as a connection material.
That is, both ends of the metal wiring 16 were connected to the conductive layer 2B and the external connection terminal 43 by using the solder. The external connection terminal 43 was connected to the ground (GND) potential of the printed circuit board 7. Thus, when the printed circuit board 7 was fixed to the frame 4 with solder, the printed circuit board 7 was connected to the frame potential through the ground potential. Thus, the same effect as that of the twenty-first embodiment can be obtained.
[Example 24]
FIG. 35 is a cross-sectional view for explaining the liquid crystal display device of this embodiment, wherein 1 is a liquid crystal display element, 1A is an upper substrate, 1B is a liquid crystal layer, 1C is a sealing material, and 1D is a lower substrate. Reference numeral 2 denotes a polarizing plate (front side), 4 denotes a frame, 5 denotes a polarizing plate (back side), 22 denotes a rubber spacer, and 47 denotes a conductive film. The conductive film 47 is formed directly on the upper substrate 1A so as to cover at least the entire display region.
In this embodiment, an ITO film having a thickness of 50 nm is formed as the conductive film 47 by a sputtering method. It is desirable that the upper substrate 1A be a color filter substrate (CF substrate). ITO is formed on the TFT substrate side as a pixel electrode or a terminal electrode. Therefore, since the etching process of the ITO film is included in the manufacturing process of the TFT substrate, in order to use the TFT substrate as the upper substrate, it is necessary to sputter the ITO film as the conductive film 47 after the completion of the TFT substrate manufacturing process. .
In general, a sputtering apparatus has a structure in which a substrate is placed on a stage and a film is formed on the substrate. Therefore, when the ITO film as the conductive film 47 is sputtered after the completion of the manufacturing process of the TFT substrate, it is necessary to place the TFT element side on the stage surface. There is a risk that the element will be destroyed, resulting in a decrease in yield.
On the other hand, in the TN type TFT liquid crystal panel, an ITO film is provided as a common electrode on the liquid crystal layer side of the CF substrate, but since the ITO film can be entirely covered, an etching step is not required. On the other hand, in the lateral electric field type TFT liquid crystal panel, an ITO film is not required on the liquid crystal layer side of the CF substrate due to its operation principle. Therefore, in any case, since the ITO etching step is not required, the ITO film as the conductive film 47 can be formed before the CF is formed on the CF substrate. Therefore, the ITO film as the conductive film 47 can be formed directly on a glass substrate on which nothing is formed by a sputtering method.
Therefore, there is no effect on the yield due to the formation of the conductive film 47. The conductive film 47 was electrically connected to the metal frame 4 by using the plastic member 21 in which the metal foil shown in FIG. 19 was laminated on the surface.
FIG. 36 is a plan view for explaining the liquid crystal display device of this embodiment. The mechanical connection between the liquid crystal display element 1 and the frame 4 was made with a double-sided adhesive tape formed on both sides of the rubber spacer 22. The polarizing plate 2 is larger than the display area and smaller than the frame boundary. One of the reasons is that when the polarizing plate is damaged, it is peeled off and a new polarizing plate is pasted, so that the so-called polarizing plate regeneration work is facilitated and the yield is improved. This is because the connection resistance is reduced by electrically connecting the conductive film 47 and the frame 4 in the region where the film 47 is exposed.
The number of the plastic members 21 with the metal foil laminated on the surface can satisfy the connection resistance value required for the EMI countermeasure even if only one, but is two or more in consideration of long-term reliability and redundancy. It is desirable.
Further, it is desirable that the resistance value between the frame 4 and the conductive film 47 including the connection resistance by the plastic member 21 having the metal foil laminated on the surface thereof is made as equal as possible in the plane of the conductive film 47. Also, from the viewpoint of the reliability of the mechanical connection strength between the frame 4 and the liquid crystal display element 1, it is desirable that the plastic members 21 having the metal foil laminated on the surface are symmetrically arranged.
Therefore, in the present embodiment, two plastic members 21 each having a metal foil laminated on the surface are arranged on the short stitch side of the screen, that is, four in total. As a result, the same EMI reduction effect as in the fourth embodiment was realized.
In this embodiment, an ITO film is used as the conductive film 47. However, ITO, SnO _Two , In _Two O _Three , Sb _Two O _Three May be used.
The number of the plastic members 21 with the metal foil laminated on the surface may be one or more. For the electrical connection between the conductive film 70 and the frame 4, instead of the plastic member 21 having a metal foil laminated on the surface, a rubber containing a conductive filler as in the third embodiment may be used. A rubber containing carbon may be used in the same manner as in the fourth embodiment, and fine particles of any one of Au, Ag, Cu, Co, Ni, and Sn or alloys are mixed as in the fifth embodiment. Rubber may be used.
Further, a rubber in which a metal foil is laminated on the surface in the same manner as in the sixth embodiment, a rubber in which a metal foil is laminated on the surface in the same manner as in the seventh embodiment, and a carbon-containing rubber, and Au and Ag in the same manner as in the eighth embodiment , Cu, Co, Ni, Sn, or Pb may be used, or an ultrasonic solder (Cerasolzer) or a silver paste similar to that of the ninth embodiment may be used. It should be noted that a material that contains any of Au, Ag, Cu, Co, Ni, Sn, and Pb in the resin instead of the silver paste and becomes solid when completed may be used. Furthermore, the connection may be made using the same metal wiring 17 as in the tenth embodiment or the same metal foil tape 19 as in the eleventh embodiment.
[Example 25]
FIG. 37 is a plan view corresponding to FIG. 36 for explaining the liquid crystal display device of this embodiment. In this embodiment, a plastic member 21 in which a rubber spacer 22 is formed all around and a metal foil is laminated on the surface is shown. By forming the liquid crystal display element 1 so as not to intersect with the rubber spacer 22, the mechanical connection strength between the liquid crystal display element 1 and the frame 4 can be increased.
[Example 26]
FIG. 38 is a plan view corresponding to FIG. 36 for explaining the liquid crystal display device of this embodiment. In this embodiment, the plastic member 21 in which metal foil is laminated on the surface serves as the rubber spacer 22. Further, the contact resistance can be further reduced.
[Example 27]
FIG. 39 is a plan view corresponding to FIG. 14 for explaining the eighth embodiment for explaining the liquid crystal display device of the present embodiment, and FIG. 16 for explaining the ninth embodiment. The difference from the ninth embodiment is that the frame 4 and the conductive film 47 are electrically connected. In this embodiment, the contact resistance can be further reduced as compared with the eighth and ninth embodiments.
(Example 28)
FIG. 40 is a sectional view of a principal part corresponding to FIG. 17 of the tenth embodiment for explaining the liquid crystal display device of the present embodiment. The difference between this embodiment and the tenth embodiment is that one end of the metal wiring 16 is electrically conductive. That is, it is electrically connected to the film 47. Thereby, the contact resistance can be further reduced as compared with the tenth embodiment.
[Example 29]
FIG. 41 is a sectional view of a principal part corresponding to FIG. 18 of the eleventh embodiment for explaining the liquid crystal display device of the present embodiment. The difference between the present embodiment and the eleventh embodiment is that one end of the metal foil tape 17 is electrically conductive. That is, it is electrically connected to the conductive film 47. Thereby, the contact resistance can be further reduced as compared with the eleventh embodiment.
[Example 30]
FIG. 42 is a cross-sectional view of main parts for explaining the liquid crystal display device of this embodiment. The difference between this embodiment and the above-described embodiment 24 is that the conductive film 47 and the connection electrode 1E shown in the above-described embodiment 13 are different. That is, an electrical connection was made between them.
In this embodiment, the conductive film 47 and the connection electrode 1E were directly connected by the ultrasonic solder 19. Since both the conductive film 47 and the connection electrode 1E are formed on the glass substrate, the connection by the ultrasonic soldering (cera solder) for attaching the glass solder has high connection reliability and simplifies the operation. This is because production costs can be reduced.
At the time of this soldering operation, there is a risk that other signal wirings on the lower substrate 1D may be erroneously short-circuited, but this can be prevented by using the same configuration as in the fifteenth embodiment. Thereby, the same effect as in the twenty-fourth embodiment can be obtained.
[Example 31]
FIG. 43 is a sectional view of a principal part showing a method of electrical connection of the liquid crystal display device of the present embodiment, and FIG. 44 is a plan view thereof.
In this embodiment, the external connection terminals 43 are formed on the printed circuit board 7 that supplies a control signal to the video signal drive circuit 201 (described later with reference to FIG. 45), and the connection between the conductive film 47 and the external connection terminals 43 is performed. Electrical connection was made between them using a connection material.
As the connection material, a coated metal wiring 16 was used, one end of which was connected to the conductive film 47 by the ultrasonic solder 19, and the other end was soldered to the external connection terminal 43 by the metal solder 14. The external connection terminal 43 was connected to the ground potential of the printed circuit board 7.
Accordingly, when the printed circuit board 7 is fixed to the frame 4 by soldering, the printed circuit board 7 is connected to the frame potential through the ground potential of the printed circuit board 7, and the same effect as in the twenty-fifth embodiment can be obtained.
[Example 32]
FIG. 45 is a schematic explanatory diagram of a signal system for driving a liquid crystal display element.
In FIG. 1, a liquid crystal display element 1 includes a transparent substrate 1A and a transparent substrate 1B as an envelope, and a liquid crystal layer is interposed between them. On the surface of the transparent substrate 1B, which is a so-called lower substrate, on the liquid crystal layer side, scanning signal lines 41 extending in the x direction in the figure and arranged in parallel in the y direction are formed. A video signal line 40 extending in the y direction and in parallel with the x direction is formed insulated from the MATA and scanning signal lines 41.
An ITO film is formed as a reference electrode 53 on the liquid crystal layer side of the transparent substrate 1A serving as the upper substrate, and an ITO film is formed on the surface on the display surface side as the conductive film 47 similarly to the twenty-fourth embodiment. ing.
An external connection terminal 43 is formed on a printed circuit board 300 that supplies a control signal to the video signal drive circuit 201, and is connected between the conductive film 47 and the external connection terminal 43 in the same manner as in the twenty-third embodiment. The electrical connection is made by the material.
A voltage is supplied to the external connection terminal 43 from the liquid crystal drive power supply circuit 203. A rectangular area surrounded by the scanning signal lines 41 and the video signal lines 40 is a pixel area, and these pixel areas are arranged in a matrix to constitute a display unit.
The liquid crystal display element 1 includes a vertical scanning circuit 200 and a video signal driving circuit 201 as external circuits, and the vertical scanning circuit 200 sequentially supplies a scanning signal (voltage) to each of the scanning signal lines 41. The video signal drive circuit 201 supplies a video signal (voltage) to the video signal line 40 in accordance with the timing.
Power is supplied to the vertical scanning circuit 200 and the video signal driving circuit 201 from the liquid crystal driving power supply circuit 203, and image information from the CPU 204 is divided into display data and control signals by the controller 205 and input. It has become.
The voltage applied to the reference electrode 53 is also supplied from the liquid crystal drive power supply circuit 203. An AC waveform may be applied to the voltage waveform applied to the reference electrode 53. Such driving is referred to as common AC driving. In this case, an AC electric field component is radiated from the reference electrode 53.
At this time, a DC voltage is supplied to the conductive film 47 to make it a constant potential, so that the effect of reducing EMI can be obtained.
Further, by applying an AC waveform having a phase opposite to that of the AC waveform applied to the reference electrode 53 to the conductive film 47, the reduction effect can be further increased.
FIG. 46 is a waveform diagram showing an AC waveform applied to the conductive film and applied to the reference electrode and an AC wave having the opposite phase.
In the figure, reference numeral 400 denotes an AC waveform applied to the reference electrode 53, and reference numeral 401 denotes an AC waveform having a phase opposite to that of the AC waveform applied to the conductive electrode 47. The voltages in the figures are relative values.
The emitted leakage electric field is proportional to the sum of the voltage proportional to the AC waveform 400 and the voltage proportional to the AC waveform 401 having the opposite phase. Therefore, by applying the AC waveform 401, which is an AC voltage having an opposite phase to the AC waveform 400, to the conductive film 47, the effect of further reducing the leakage electric field is exhibited as compared with the case where a DC voltage is applied to the conductive film 47. be able to.
It is desirable that the amplitude of the AC waveform 401 is smaller than the AC waveform 400. This is because when the amplitude of the AC waveform 401 is large, the AC waveform 401 itself becomes a source of a new leakage electric field.
The purpose of the present invention is to minimize the leakage electric field due to the total sum of the AC waveform 400 and the AC waveform 401. For this purpose, the amplitude of the AC waveform 401 is practically 4 times smaller than the amplitude of the AC waveform 400. Desirably, it is 1/4 to 3/4.
Since the AC waveform applied to the reference electrode is a monotonous AC waveform created by the liquid crystal drive power supply circuit 203, the AC waveform 401 of the inversion layer applied to the conductive film 70 is generated by the liquid crystal drive power supply circuit 203 itself. It can be easily formed. Therefore, the amount of the leakage electric field can be further reduced without significantly increasing the cost.
FIG. 47 is an exploded perspective view illustrating a specific example of the overall configuration of the liquid crystal display device according to the present invention.
In the figure, MDL is a liquid crystal display device, SHD is a metal shield case which is a metal upper frame, WD is a display window defining an effective screen of a liquid crystal display module, PNL is a liquid crystal panel, and PL is a polarizing plate (surface). The side polarizing plate, the back side polarizing plate is not shown), PCB1 is a drain side circuit board, PCB2 is a gate side circuit board, PCB3 is an interface circuit board, PRS is a prism sheet, SPS is a diffusion sheet, and GLB is light guide. Body, RFS is a reflection sheet, BL is a backlight, LP is a cold cathode fluorescent lamp that constitutes a lamp of the backlight BL, LS is a reflection sheet, GC is a rubber bush, LPC is a lamp cable, and MCA is a light guide GLB. Lower frames JN1, 2, and 3 are joiners for connecting circuit boards, and TCP1 and TCP2 are frames. Flop carrier package, INS1,2,3 insulating sheet, GC rubber cushion, BAT is double-sided adhesive tape, ILS is shading spacer.
The above-mentioned components are stacked and fixed between the upper frame SHD and the lower frame MCA made of metal to constitute the liquid crystal display device MDL.
On the upper surface of the liquid crystal panel PNL, the conductive polarizer described in each of the above embodiments is laminated and connected to the ground potential via a frame, or a constant level DC voltage, or an AC waveform applied to the reference electrode. And an AC waveform having the opposite phase to the above.
Further, on the back surface of the liquid crystal panel PNL, a backlight BL formed by laminating various optical sheets on a back side polarizing plate and a light guide GLB is installed, and a display window is provided by illuminating an image formed on the liquid crystal display panel PNL. Display on WD.
FIG. 48 is a perspective view of a laptop personal computer as an example of an electronic device on which the liquid crystal display device according to the present invention is mounted.
In the figure, a host computer section having a CPU is mounted on a main body having a keyboard section, and a liquid crystal display device MDL having the liquid crystal panel PNL is mounted on a display section connected to the main body via a hinge. ing.
In this example, since the drain driver peripheral circuit (PCB1) mounted on one side can be arranged above the display section above the hinge, compact mounting is possible.
First, a signal from the information device goes to a display control integrated circuit element (TCON) from a connector located substantially at the center of the interface board PCB3 on the left side of the figure, and the converted display data is transmitted to the periphery of the drain driver. Flow to the circuit.
Although the present invention has been described in detail with reference to various embodiments, the present invention is not limited to the above-described embodiments, and it is needless to say that various modifications can be made without departing from the gist of the present invention.
The embodiments described above can be applied not only to various types of liquid crystal display devices but also to various polarizing plates requiring conductivity.
Further, the case where any one of the first to thirty-second embodiments is combined is also included in the technical scope of the present invention.
Regarding the configuration of the electrical connection, in this specification, the conductive layer in the polarizing plate, the conductive film on the polarizing plate on the display surface side, the conductive film directly formed on the substrate on the display surface side The connection method described in any one of the above, a conductive layer in the polarizing plate, a conductive film on the polarizing plate on the display surface side, a conductive film formed directly on the substrate on the display surface side , All fall within the technical category of the present invention.

FIG. 1 is a cross-sectional view of a liquid crystal display device for explaining a first embodiment of the present invention. FIG. 3 is a cross-sectional view illustrating a structure of a polarizing plate on a surface of a liquid crystal display element. FIG. 10 is a cross-sectional view illustrating a structure for reducing a leakage electric field, which describes a third embodiment of the liquid crystal display device. FIG. 3 is a configuration diagram of an experimental system for measuring a leakage electromagnetic field intensity. FIG. 5 is a cross-sectional view of the liquid crystal display device used in the experimental system shown in FIG. FIG. 4 is a characteristic diagram showing the connection resistance dependence of VLEF and ELEF in a sample in which the sheet resistance of the conductive layer is 2 × 10 3 Ω / □. FIG. 7 is a characteristic diagram showing an enlarged evaluation result in a region where the connection resistance is low in FIG. 6. FIG. 4 is a characteristic diagram showing the sheet resistance dependence of VLEF and ELEF in a sample having a connection resistance of 4 × 10 3 Ω. It is sectional drawing explaining the structural example of a conductive rubber. It is sectional drawing explaining other structural examples of a conductive rubber. It is sectional drawing explaining other structural examples of a conductive rubber. It is sectional drawing explaining further another structural example of a conductive rubber. It is sectional drawing explaining further another structural example of a conductive rubber. FIG. 16 is a sectional view of a main part of a liquid crystal display device according to an eighth embodiment of the present invention. FIG. 15 is a schematic plan view of FIG. FIG. 14 is a sectional view of a main part of a liquid crystal display device according to a ninth embodiment of the present invention. It is principal part sectional drawing of the liquid crystal display device of 10th Example of this invention. It is principal part sectional drawing of the liquid crystal display device of the 11th Example of this invention. FIG. 21 is a cross-sectional view illustrating an example of a connection member interposed between a frame and a liquid crystal display element according to a twelfth embodiment of the present invention. FIG. 21 is a perspective plan view showing a method of fixing a frame 4 and a polarizing plate in a liquid crystal display device according to a twelfth embodiment of the present invention. FIG. 33 is a perspective plan view showing a modification of the fixing method of the frame 4 and the polarizing plate in the liquid crystal display device according to the twelfth embodiment of the present invention. FIG. 21 is a cross-sectional view illustrating a method for fixing a frame 4 and a polarizing plate in a liquid crystal display device according to a thirteenth embodiment of the present invention. FIG. 33 is a plan view illustrating a configuration of a lower substrate in a liquid crystal display device according to a thirteenth embodiment of the present invention. It is a sectional view explaining an important section structure of a connection electrode part in a liquid crystal display of a 15th example of the present invention. It is a sectional view explaining the important section structure of the connection electrode part in the liquid crystal display of a 16th example of the present invention. FIG. 37 is a schematic plan view illustrating a structure of a connection electrode portion in a liquid crystal display device according to a seventeenth embodiment of the present invention. It is a sectional view for explaining the structure of the liquid crystal display device of the eighteenth embodiment of the present invention. FIG. 33 is a cross-sectional view of a principal part explaining the configuration of a liquid crystal display of a twentieth embodiment of the present invention. It is the conceptual diagram which looked at the polarizing plate used for the liquid crystal display device of the 21st Example of this invention from diagonal direction. It is a top view showing the mounting state of the polarizing plate used for the liquid crystal display of a 21st example of the present invention. It is a top view showing the mounting state of the polarizing plate used for the liquid crystal display of a 21st example of the present invention. It is explanatory drawing of an example of the manufacturing procedure of the polarizing plate used for the liquid crystal display device of the 21st Example of this invention. FIG. 39 is a cross-sectional view of a principal part explaining an electrical connection state of a polarizing plate in a liquid crystal display device according to a 23rd embodiment of the present invention. FIG. 33 is a plan view illustrating an electrical connection state of a polarizing plate in a liquid crystal display device according to a twenty-third embodiment of the present invention. FIG. 24 is a cross-sectional view illustrating a liquid crystal display device according to a twenty-fourth embodiment of the present invention. FIG. 35 is a plan view illustrating a liquid crystal display device according to a twenty-fourth embodiment of the present invention. FIG. 37 is a plan view corresponding to FIG. 36 and illustrating a liquid crystal display device according to a twenty-fifth embodiment of the present invention. FIG. 37 is a plan view corresponding to FIG. 36 for illustrating a liquid crystal display device according to a twenty-sixth embodiment of the present invention. FIG. 18 is a plan view corresponding to FIG. 14 illustrating the eighth embodiment illustrating the liquid crystal display device according to the twenty-seventh embodiment of the present invention and FIG. 16 illustrating the ninth embodiment. FIG. 18 is a sectional view of a principal part corresponding to FIG. 17 of the tenth embodiment for explaining the liquid crystal display device of the twenty-eighth embodiment of the present invention. FIG. 19 is a cross-sectional view of a principal part corresponding to FIG. 18 of the eleventh embodiment for explaining the liquid crystal display device of the twenty-ninth embodiment of the present invention. It is a principal part sectional view explaining the liquid crystal display of a 30th example of the present invention. FIG. 39 is a cross-sectional view of a principal part showing a method of electrical connection of the liquid crystal display device according to the thirty-first embodiment of the present invention. FIG. 37 is a plan view showing a method of electrically connecting a liquid crystal display device according to a thirty-first embodiment of the present invention. FIG. 3 is a schematic explanatory diagram of a signal system for driving a liquid crystal display element. FIG. 5 is a waveform diagram showing an AC waveform applied to a reference electrode on a conductive film and an AC wave having an opposite phase to the AC waveform. FIG. 2 is an exploded perspective view illustrating a specific configuration example of the liquid crystal display device according to the present invention. 1 is an external view of a laptop personal computer as a specific example of a device using a liquid crystal display device according to the present invention.

Explanation of reference numerals

Reference Signs List 1 liquid crystal display element 2 polarizing plate on liquid crystal display element surface 3 rubber for connection 4 metal frame 5 polarizing plate on back surface of liquid crystal display element 6 backlight unit 7 printed circuit board.

Claims (4)

In a liquid crystal display device having a liquid crystal display element, a metal frame disposed above the liquid crystal display element, and a conductive layer formed on an upper surface of the liquid crystal display element,
A first spacer disposed on a side of the liquid crystal display element; a second spacer disposed on the liquid crystal display element; and a conductive member for electrically connecting the metallic frame and the conductive layer. And
The liquid crystal display device according to claim 1, wherein one end of the conductive member is pressed against the metallic frame by the first spacer, and the other end of the conductive member is pressed against the conductive layer by the second spacer.   The liquid crystal display device according to claim 1, wherein the conductive layer is formed on a polarizing plate laminated on the liquid crystal display element.   The liquid crystal display device according to claim 1, wherein the conductive layer is formed on a surface of the liquid crystal display element. The liquid crystal display device according to claim 1, wherein the conductive member is a metal foil tape.

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