JPH1010565A - Liquid crystal display and electronic equipment - Google Patents

Abstract

An object of the present invention is to prevent electromagnetic interference (EMI) from being caused by mutual interference between a liquid crystal display device and other electronic circuits. In order to isolate an output terminal of a liquid crystal driving IC to a liquid crystal display from other electronic circuits, wirings at both ends of electrical connection means are set to a ground potential. Further, the periphery of the display section is set to the ground potential using the wiring of the transparent electrode of the liquid crystal display. The wiring of the terminals at both ends of the terminal section 5 is connected to the liquid crystal driving I / O from the CPU.
The input signal to C2 and the output signal to the liquid crystal display 4 are arranged so as to sandwich them. The terminals at both ends of the terminal portion 5 are fixed to the ground potential on the main body side circuit board. The shielding effect of preventing electromagnetic interference with other electronic circuits can be obtained by setting the wiring at both ends of the circuit board and the electrical connection means and the liquid crystal display to the ground potential.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display and an electronic apparatus, and more particularly, to an electromagnetic interference (hereinafter referred to as "EM")
The present invention relates to a liquid crystal display device and an electronic device which sufficiently take measures.

[0002]

2. Description of the Related Art FIG. 2 shows an example of a conventional liquid crystal display device.
Reference numeral 1 denotes a tape carrier package, which is an IC for driving a liquid crystal.
2 is mounted with TAB (tape automated bonding). Between the liquid crystal display 4 and the tape carrier package 1, a flexible connector as an electrical connection means is provided. Here, a thermocompression bonding type heat seal will be described as an example of the flexible connector. The heat seal 3 connects the output terminal of the tape carrier package 1 and the terminal formed by the transparent electrode of the liquid crystal display 4, so that the electrical conduction of the liquid crystal display device is maintained. Further, when the present liquid crystal display device is incorporated in the main body of an electronic device, the liquid crystal display 4 is mounted on an exterior panel, and the tape carrier package 1 is mounted on a substrate on which other ICs such as a CPU and a RAM are mounted by soldering or the like. . Since the heat seal 3 has flexibility, it bends flexibly to facilitate the attachment of the two.

[0003]

In recent years, with the miniaturization of electronic equipment, electronic components such as an antenna and an oscillator have been arranged closer to the periphery of a liquid crystal display device. Therefore, the influence of mutual interference between the liquid crystal display device and other electronic circuits has become a problem as EMI.

An object of the present invention is to provide a liquid crystal display device and an electronic apparatus which can prevent EMI interference between the liquid crystal display device and other electronic circuits, which is the above problem.

[0005]

According to an aspect of the present invention, there is provided a liquid crystal display device, comprising: a liquid crystal display; a circuit board on which a driving IC is mounted; A liquid crystal display device having an electrical connection means for electrically connecting the wirings, wherein wirings located at both ends of wirings provided in the electrical connection means are wirings for a ground potential. I do. With such a configuration, a shielding effect can be provided at both ends of the electrical connection means of the liquid crystal display device. That is, the liquid crystal driving I
The signal terminal between C and the liquid crystal display can be isolated from other electronic circuits, and measures against electromagnetic interference can be taken. Preferably, the circuit board uses a tape carrier package.

[0006] The liquid crystal display device according to claim 3 is
In addition to any one of the above structures, the invention is characterized in that the periphery of the liquid crystal display is set to the ground potential by using a wiring pattern formed inside the liquid crystal display. By adopting such a configuration, a shielding effect is also obtained around the liquid crystal display, and it is possible to further take measures against electromagnetic interference as the liquid crystal display device.

[0007] The liquid crystal display device according to claim 4 is
In addition to the configuration of the third aspect, the wiring pattern uses a transparent conductive film. With such a configuration, since the electrodes for the liquid crystal display are used, the number of steps can be provided with the same number of steps as before without increasing the number of components. Also, the manufacturing cost can be maintained at the conventional level.

[0008] The liquid crystal display device according to claim 5 is
In addition to any one of the above configurations, the electrical connection unit is characterized by using a flexible connector. If a flexible connector is used as the electrical connection means, the degree of freedom in assembling into an electronic device or the like increases, which is effective.

In the above-mentioned structure, or as in the liquid crystal display device according to the sixth aspect, the electric connection means includes:
It is characterized by using an anisotropic conductive film. With such a configuration, the pitch between terminals can be made finer, and the size of the entire device can be reduced, or more terminals can be increased within a certain range.

As another method of the electric connection means,
As in the liquid crystal display device according to the seventh aspect, it is preferable that an elastic rubber connector be used for the electric connection means.

Further, as another means of the device, as in the liquid crystal display device according to claim 8, a first glass substrate and a second glass substrate disposed thereon and having a smaller area than the first glass substrate are provided. A liquid crystal display comprising a glass substrate; a driving IC mounted on the first glass substrate and connected to wiring formed on the surface of the first glass substrate; The liquid crystal display is provided at an installation potential using a transparent conductive film disposed between the first glass substrate and the first glass substrate. In which the outermost wiring is provided at the ground potential.

An electronic device incorporating the above-described liquid crystal display device includes a liquid crystal display, a tape carrier package having a driving IC mounted thereon, the liquid crystal display and the liquid crystal display. A liquid crystal display device having wiring for electrically connecting to a tape carrier package, and wiring located at both ends of the wiring, and electrical connection means serving as wiring for ground potential; and It is characterized by having an exterior panel to be fixed and a circuit board electrically connected to the tape carrier package.

According to another aspect of the present invention, a liquid crystal display, a mounting board on which at least a driving IC is mounted, and an electrical connection between the liquid crystal display and the mounting board are provided. A liquid crystal display device having a wiring, and wiring located at both ends of the wiring having electrical connection means serving as a wiring for ground potential, and an exterior panel to which the liquid crystal display is fixed. I do.

A liquid crystal display comprising a first glass substrate and a second glass substrate disposed on the first glass substrate and having a smaller area than the first glass substrate, as in the electronic device according to claim 11. A driving IC mounted on the first glass substrate and connected to wiring formed on the surface of the first glass substrate; and a driving IC disposed between the first glass substrate and the second glass substrate. A liquid crystal display device in which the periphery of the liquid crystal display body is set to an installation potential using a transparent conductive film and the outermost wiring of the wirings connected to the driving IC is provided at a ground potential; And an exterior panel to which the liquid crystal display is fixed.

In each of the above electronic devices, measures are taken to prevent electromagnetic interference of the liquid crystal display device itself, so that there is no problem of electromagnetic interference with other circuits.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) FIG. 1 shows an embodiment of a liquid crystal display device according to the present invention. As shown in FIG. 1, reference numeral 1 denotes a tape carrier package. The base material is a flexible member, for example, a tape-shaped resin made of polyimide, and a wiring pattern made of copper foil is provided at a desired position thereon, and a terminal formed on the wiring pattern is provided. The liquid crystal drive IC 2 is connected to the electrode of the liquid crystal drive IC 2
AB mounted. The wiring pattern of the tape carrier package 1 is formed by etching a copper foil.
The terminal portion of the tape carrier package 1 on the liquid crystal display side (ie, the output terminal side) and the terminal portion on the substrate side (ie, the input terminal side) of the electronic device main body are plated with tin to improve conductivity. Reference numeral 3 denotes a flexible connector as an electrical connection means, and here, a thermocompression bonding type heat seal is taken as an example. The heat seal 3 connects an output terminal of the tape carrier package 1 to a transparent electrode which is a terminal of the liquid crystal display 4. In the heat seal 3, a wiring layer is formed of silver carbon or graphite on a polyester base film, and an adhesive layer is formed thereon. On one glass of the liquid crystal display 4, a terminal portion is provided by a transparent electrode made of an ITO film (an example of a transparent conductive film). The bonding between the output terminal of the liquid crystal driving IC 2 and the heat seal 3 and the bonding between the terminal portion of the liquid crystal display 4 and the heat seal 3 are performed by thermosetting an adhesive in a thermocompression bonding step, and at the same time, the wiring layer is formed. And each terminal are electrically connected. The interface signal between the CPU and the liquid crystal driving IC and the power are supplied from a circuit board (not shown) of the electronic device body. In particular, the input terminal 5 of the tape carrier package 1 is mounted on a circuit board of the electronic device body by soldering or the like. The wiring patterns at both ends of the terminal portion 5 are connected and fixed to the ground potential of the electronic device main body side circuit board. Here, the tape carrier package 1
The wiring patterns at both ends of the terminal section 5 are arranged so that an input signal from the CPU to the liquid crystal driving IC 2 and an output signal to the liquid crystal display 4 are interposed therebetween, and are fixed to the ground potential by the above structure. In this example, the ground potential wiring is one at each end, but a plurality of wirings may be arranged to further enhance the shielding effect. In this case, it is preferable to use the wiring for setting the potential from the outer wiring. Further, the wiring having the ground potential at both ends may be made wider than other wirings.

As an electronic apparatus incorporating the above-described liquid crystal display device, a liquid crystal display 4 is mounted on an exterior panel, and a terminal portion on the input side of the tape carrier package 1 is mounted with other ICs such as a CPU and a RAM. It has a structure mounted on a substrate by soldering or the like.

Embodiment 2 FIG. 3 shows another embodiment of the liquid crystal display device according to the present invention. Since most of them are the same as the first embodiment, only the parts different from the first embodiment will be described in detail. The terminals at both ends of the liquid crystal display 4 are fixed to the ground potential of the main body side circuit board (not shown) via the heat seal 3 and the tape carrier package 1 on which the liquid crystal driving IC 2 is TAB mounted.

In this embodiment, wiring is routed from terminals at both ends in the liquid crystal display 4 so as to surround the periphery of the liquid crystal display 4.
The periphery of the liquid crystal display 4 is set to the ground potential by establishing conduction with the wiring patterns at both ends of the heat seal described in the first embodiment, that is, by establishing conduction with the ground potential. Thereby, it is possible to obtain a shielding effect also for each control signal (common signal and segment signal) of the display unit by the ITO film of the liquid crystal display 4. As an electronic device incorporating the above-described liquid crystal display device, the liquid crystal display 4 is attached to an exterior panel as in the first embodiment, and the input terminal of the tape carrier package 1 is connected to a CPU or RA.
It has a structure mounted on a substrate on which other ICs such as M are mounted by soldering or the like.

(Embodiment 3) FIG. 4 shows a third embodiment of the liquid crystal display device according to the present invention. As shown, a liquid crystal driving IC 2 is mounted on a tape carrier package 1 made of polyimide.
AB mounted. The wiring pattern of the tape carrier package 1 is formed by etching a copper foil. Each terminal portion of the output terminal located on the liquid crystal display side and the input terminal located on the side of the main body circuit board (not shown) is plated with tin, thereby improving the conductivity. The feature of this example is that an anisotropic conductive film is used for the electrical connection means. The specific structure will be described below. On one glass of the liquid crystal display 4, there is a terminal portion made of a transparent electrode made of an ITO film. The tape-shaped anisotropic conductive film 6 is arranged on the terminal portion. The tape carrier package 1 on which the liquid crystal driving IC 2 is mounted is placed thereon, and thermocompression-bonded. At that time, the liquid crystal driving IC on the tape carrier package 1
After the output terminal 2 is aligned with the transparent electrode made of the ITO film of the liquid crystal display 4, thermocompression bonding is performed. In the anisotropic conductive film 6, a ball-shaped conductive material (resin particles plated with Au) is uniformly mixed in the adhesive layer. Where there is a terminal portion above and below, a ball-shaped conductive material comes into contact with the terminal portion by the thermocompression bonding step, and electrical conduction is performed.

The input terminal 5 of the tape carrier package 1 is mounted on a circuit board on the main body side by soldering. The terminals at both ends of the terminal portion 5 are fixed to the ground potential on the main body side circuit board.

Here, the wiring of the terminals at both ends of the terminal portion 5 is C
The input signal from the PU to the liquid crystal driving IC 2 and the output signal to the liquid crystal display 4 are interposed therebetween, and are fixed to the ground potential by the above structure. As an electronic device incorporating the above-described liquid crystal display device, the liquid crystal display 4 is attached to an exterior panel as in the first and second embodiments, and the input side terminal of the tape carrier package 1 has a CPU or R
The structure is such that it is mounted by soldering or the like on a substrate on which another IC such as an AM is mounted.

(Embodiment 4) FIG. 5 shows a fourth embodiment of the liquid crystal display device according to the present invention. In the drawings, (a) is a diagram viewed from the front, and (b) is a cross-sectional diagram along AA ′. The liquid crystal driving IC 2 is mounted on the circuit board 8 by COB. Each input / output terminal of the liquid crystal drive IC 2 is wire-bonded to a corresponding Au-plated pattern on the circuit board 8 by an Au wire. The main feature of this example is that a rubber connector is used for the electrical connection means. The specific structure will be described below. The output signal of the liquid crystal driving IC 2 and the wiring of the ground potential are connected to the liquid crystal display 4 through an elastic rubber connector 7. In the structure of the rubber connector 7, a striped conductor is embedded in an elastic rubber. The distance between the conductors is shorter than the distance between the terminals of the circuit board 8 and the distance between the terminals of the transparent electrodes of the liquid crystal display 4 made of ITO, and is designed so that two or three conductors are inserted per terminal distance. Here, the outermost wiring pattern of the circuit board 8 is set to the ground potential, and the elastic rubber connector 7 has a structure in which the both ends thereof are set to the ground potential. ing. Further, the wirings at both ends of the liquid crystal display 4 are also set to the ground potential, so that interference between the liquid crystal display and the surroundings due to EMI is prevented.

(Embodiment 5) FIG. 6 shows a fifth embodiment of the liquid crystal display device according to the present invention. In the drawings, (a) is a diagram viewed from the front, and (b) is a cross-sectional diagram along AA ′. Reference numeral 4 denotes a liquid crystal display, which includes a first glass substrate (lower glass substrate) and a second glass substrate (upper glass substrate) disposed thereon and having a smaller area than the lower glass substrate. A transparent conductive film is disposed between the upper glass substrate and the lower glass substrate. Utilizing the transparent conductive film, the periphery of the liquid crystal display 4 is provided at the set potential. Reference numeral 2 denotes a driving IC mounted on the lower glass substrate and connected to wiring formed on the surface of the lower glass substrate. That is, the liquid crystal driving IC 2 is COG mounted on the lower glass substrate of the liquid crystal display 4. Of the wiring connected to the driving IC 2, the wiring at the outermost position on the lower glass substrate is also provided so as to be at the ground potential. The lower glass of the liquid crystal display 4 has a terminal portion formed of a transparent electrode made of ITO. The anisotropic conductive film 6 is patterned thereon. Further, the liquid crystal driving IC 2 is flip-chip mounted thereon with the active surface facing down, whereby the mounting of the IC on glass (COG mounting) is completed.

Here, among the wirings formed by the transparent electrodes on the glass, the wirings at both ends reaching the display pattern portion are set to the ground potential. The wiring around the display pattern portion is also set to the ground potential. This makes it possible to isolate the liquid crystal driving IC and the liquid crystal display from interference with other surrounding circuits due to EMI.

As described above, in the embodiment, the case where the number of the liquid crystal driving ICs is one has been described. However, the embodiment can be similarly carried out when a plurality of ICs are mounted. The liquid crystal driving I
The same can be applied to the case where the mounting location of C is not limited to one direction of the glass on one side of the liquid crystal display body, but is mounted on both the glass and the positions in two or more directions.

[0027]

According to the present invention, electromagnetic interference with other electronic circuits is prevented by setting the wiring at both ends of the circuit board and the electrical connection means such as a heat seal, a conductive adhesive or a rubber connector to the ground potential. It is possible to obtain a shielding effect to prevent.

Further, by setting the periphery of the liquid crystal display to the ground potential by the transparent conductive film inside the liquid crystal display, it is possible to further enhance the shielding effect.

[Brief description of the drawings]

FIG. 1 is a diagram showing one embodiment of the present invention.

FIG. 2 is a diagram showing a conventional example.

FIG. 3 is a diagram showing a second embodiment of the present invention.

FIG. 4 is a diagram showing a third embodiment of the present invention.

FIG. 5 is a diagram showing a fourth embodiment of the present invention.

FIG. 6 is a diagram showing a fifth embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 tape carrier package 2 drive IC 3 heat seal 4 liquid crystal display 5 input side terminal of tape carrier package 6 anisotropic conductive film 7 rubber connector 8 circuit board

Claims (11)

[Claims] 1. A liquid crystal display device comprising: a liquid crystal display; a circuit board on which a driving IC is mounted; and electrical connection means for electrically connecting the liquid crystal display and the circuit board. A liquid crystal display device, wherein wirings located at both ends among wirings provided in the electrical connection means are wirings for ground potential. 2. The liquid crystal display device according to claim 1, wherein the circuit board is a tape carrier package. 3. The liquid crystal display device according to claim 1, wherein the periphery of the liquid crystal display is set to a ground potential using a wiring pattern formed inside the liquid crystal display. 4. The liquid crystal display device according to claim 3, wherein said wiring pattern uses a transparent conductive film. 5. The electrical connection means according to claim 1, wherein a flexible connector is used.
The liquid crystal display device as described in the above. 6. The liquid crystal display device according to claim 1, wherein said electrical connection means comprises an anisotropic conductive film. 7. The electric connection means, wherein an elastic rubber connector is used.
The liquid crystal display device as described in the above. 8. A liquid crystal display comprising a first glass substrate and a second glass substrate disposed thereon and having a smaller area than the first glass substrate; and a liquid crystal display mounted on the first glass substrate; The liquid crystal display using a driving IC connected to wiring formed on the surface of the first glass substrate and a transparent conductive film disposed between the first glass substrate and the second glass substrate. The present invention is characterized in that the periphery of the body is provided at an installation potential and the wiring at the outermost position on the first glass substrate among the wirings connected to the driving IC is provided at a ground potential. Liquid crystal display device. 9. A liquid crystal display, a tape carrier package on which a driving IC is mounted, and wiring for electrically connecting the liquid crystal display to the tape carrier package, the wiring being located at both ends of the wiring. The wiring to be provided includes a liquid crystal display device having electrical connection means serving as a wiring for a ground potential, an exterior panel to which the liquid crystal display is fixed, and a circuit board electrically connected to the tape carrier package. Electronic equipment characterized by the above. 10. A liquid crystal display and at least a driving IC
And a wiring board for electrically connecting the liquid crystal display body and the mounting board, wherein the wiring located at both ends of the wiring is an electrical connection means serving as a wiring for a ground potential. An electronic apparatus, comprising: a liquid crystal display device having: and an exterior panel to which the liquid crystal display is fixed. 11. A liquid crystal display comprising a first glass substrate and a second glass substrate disposed thereon and having a smaller area than the first glass substrate; and a liquid crystal display mounted on the first glass substrate and The liquid crystal display body is formed using a driving IC connected to wiring formed on the surface of the first glass substrate and a transparent conductive film disposed between the first glass substrate and the second glass substrate. A liquid crystal display device in which the periphery is provided with an installation potential and the outermost wiring of the wirings connected to the driving IC is provided at a ground potential, and an exterior panel to which the liquid crystal display is fixed, An electronic device comprising: