JP2008209792A - Liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device of COG type of which the frame is made narrower than heretofore. <P>SOLUTION: The liquid crystal display device relating to the first embodiment of this invention comprises: a first electrode 106 formed on a first transparent substrate 101; a second electrode 107 which is formed on a second transparent substrate 102 and is arranged so as to intersect the first electrode 106; a driving semiconductor element 105 mounted on the second transparent substrate 102; a first connection line which connects the first electrode 106 with the driving semiconductor element 105; and a second connection line 108 which connects the second electrode 107 with the driving semiconductor element 105. A part or all of the first connection line is arranged outside the first and second transparent substrates 101, 102. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a liquid crystal display device, and more particularly to a COG (Chip On Glass) liquid crystal display device in which a driver IC is directly mounted on a transparent substrate.

  In recent years, the importance of display devices has been increasing with the advancement of an advanced video and information society and the spread of multimedia systems. A liquid crystal display device is widely used as a display device because it has advantages of being thin, lightweight, and low power consumption.

  In particular, in a liquid crystal display device for a mobile communication terminal or the like that is strongly demanded for weight reduction, size reduction, and narrow frame, a COG (Chip On Glass) method in which a driver IC is directly mounted on a glass substrate is adopted. Thereby, compared with the conventional TAB (Tape Automated Bonding) system, it can implement | achieve significantly reduction in thickness and weight (for example, refer patent document 1).

FIG. 5 shows the configuration of a conventional liquid crystal panel. The liquid crystal panel 10 has a configuration in which liquid crystal is sandwiched between inner surfaces of a transparent substrate 1 having a scanning electrode 6 formed on the inner surface and a transparent substrate 2 having a signal electrode 7 formed on the inner surface. In the liquid crystal panel 10, routing wirings connected to the electrodes of the transparent substrates 1 and 2 are concentrated on one transparent substrate 2 in order to simplify the configuration and narrow the frame. In the frame region on the transparent substrate 1, a lead-out wiring 3 from the scanning electrode 6 is formed, and is electrically connected to the auxiliary wiring 4 formed on the other transparent substrate 2 through the transfer 9. . On the transparent substrate 2 on which the auxiliary wiring 4 is formed, a routing wiring 8 from the signal electrode 7 is also formed. The auxiliary wiring 4 and the routing wiring 8 are connected to the driver IC 5. The driver IC 5 is directly mounted on the transparent substrate 2, that is, COG (Chip On Glass).
JP 2002-72233 A

  As described above, the COG method can be made thinner and lighter than the conventional TAB method, but is required to have a narrower frame.

  The present invention has been made against the background of the above circumstances, and an object of the present invention is to provide a COG liquid crystal display device with a narrower frame than ever before.

  A liquid crystal display device according to a first aspect of the present invention includes a first electrode formed on a first transparent substrate, a second electrode formed on a second transparent substrate, and arranged to intersect the first electrode. Two electrodes, a driving semiconductor element mounted on a second transparent substrate, a first connection wiring connecting the first electrode and the driving semiconductor element, the second electrode, and the driving semiconductor element And a second connection wiring for connecting the first connection wiring and a part or the whole of the first connection wiring is disposed outside the first and second transparent substrates. As a result, a COG liquid crystal display device with a narrower frame than before can be provided.

  In the liquid crystal display device according to a second aspect of the present invention, in the above liquid crystal display device, the first connection wiring disposed outside the first and second transparent substrates is formed on a flexible printed circuit board. It is characterized by this. Thereby, a narrow frame can be surely achieved.

  The liquid crystal display device according to a third aspect of the present invention is characterized in that, in the above liquid crystal display device, the flexible printed circuit board is a double-sided wiring flexible printed circuit board. This eliminates the need for a transfer in the frame area and allows a narrower frame.

  According to the present invention, it is possible to provide a COG-type liquid crystal display device with a narrower frame than ever before.

  Embodiments of the present invention will be described below. However, the present invention is not limited to the following embodiment. In addition, for clarity of explanation, the following description and drawings are simplified as appropriate.

Embodiment 1
A liquid crystal display device according to Embodiment 1 of the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view showing a configuration of an example of a liquid crystal display device according to the present embodiment. FIG. 2 is a plan view showing the configuration of the liquid crystal panel 100 used in the liquid crystal display device. In this embodiment, an STN passive matrix liquid crystal panel will be described as an example of the liquid crystal panel 100.

  As shown in FIG. 1, the liquid crystal display device includes a liquid crystal panel 100 and a backlight unit 200. The liquid crystal panel 100 displays an image based on the input display signal. The backlight unit 200 is disposed on the non-viewing side of the liquid crystal panel 100 and emits light from the back side of the liquid crystal panel 100.

  As shown in FIGS. 1 and 2, the liquid crystal panel 100 includes a first substrate 101, a second substrate 102, a first routing wiring 103, an auxiliary wiring 104, a driver IC 105, a first electrode 106, a second electrode 107, A two-route wiring 108, an FPC (Flexible Printed Circuit) 110 that is a flexible printed circuit board, a sealing material 130, a liquid crystal 131, a spacer 132, an alignment film 133, and a polarizing plate 134 are provided. As shown in FIG. 1, the liquid crystal panel 100 includes a liquid crystal 131 in a space between a first substrate 101, a second substrate 102 disposed opposite to the first substrate 101, and a sealing material 130 that bonds the two substrates. It has an enclosed configuration. The two substrates are held at a predetermined interval by a spacer 132. As the 1st board | substrate 101 and the 2nd board | substrate 102, insulating boards, such as glass, polycarbonate, an acrylic resin, etc. which have a light transmittance, are used, for example.

  As shown in FIG. 2, a plurality of first electrodes 106 are formed on the first substrate 101 in the horizontal direction. On the other hand, a plurality of second electrodes 107 are formed on the second substrate 102 in a direction perpendicular to the first electrodes 106. The first electrode 106 and the second electrode 107 are made of a transparent conductive film such as ITO (Indium Tin Oxide), for example. A position where the first electrode 106 and the second electrode 107 intersect is a pixel. That is, the display area is composed of a plurality of pixels arranged in a matrix.

  Of the first substrate 101 and the second substrate 102 constituting the liquid crystal panel 100, the second substrate 102 has a larger planar dimension than the first substrate 101 in order to mount the driver IC 105 that is a driving semiconductor element. Is formed. Accordingly, the second substrate 102 is disposed so as to protrude from the first substrate 101.

  In the region where the second substrate 102 protrudes from the first substrate 101, the auxiliary wiring 104 for transmitting a display signal or the like to the first electrode 106 formed on the first substrate 101 and the display signal or the like to the second electrode 107. The second routing wiring 108 for transmitting the signal is formed. In addition, IC connection terminals (not shown) are formed at the ends of the auxiliary wiring 104 and the second routing wiring 108. The driver IC 105 is connected to the IC connection terminal via an anisotropic conductive adhesive. That is, the driver IC 105 is directly mounted on the second substrate 102 by a COG (Chip On Glass) method.

  The driver IC 105 outputs various control signals, scan voltages, display voltages, and the like necessary for image display based on display signals input from the outside via the external connection wiring 112.

  As shown in FIG. 1, in the first substrate 101, an alignment film 133 is formed on each of the electrodes and wirings described above. On the other hand, the second electrode 107 and the alignment film 133 are sequentially stacked on the surface of the second substrate 102 facing the first substrate 101. In addition, polarizing plates 134 are attached to the outer surfaces of the first substrate 101 and the second substrate 102, respectively.

  A backlight unit 200 is provided on the back surface of the liquid crystal panel 100. The backlight unit 200 irradiates the liquid crystal panel 100 with light from the non-viewing side of the liquid crystal panel 100. As the backlight unit 200, for example, a unit having a general configuration including a light source, a light guide plate, a reflection sheet, a diffusion sheet, a prism sheet, a reflection polarizing sheet, and the like can be used.

  Next, the operation of the above-described liquid crystal display device will be described. A scanning voltage is supplied from the driver IC 105 to each first electrode 106. On the other hand, a display voltage lower than the scanning voltage is supplied from the driver IC 105 to each second electrode 107. In accordance with the potential difference between the first electrode 106 and the second electrode 107, the alignment of the liquid crystal between the first electrode 106 and the second electrode 107 constituting each pixel changes. Thereby, the transmittance | permeability of the light from the backlight unit 200 changes and it can display.

  Here, the structure of the 1st board | substrate 101 and the 2nd board | substrate 102 which comprise the liquid crystal panel 100 is demonstrated in detail.

  On the first substrate 101, a plurality of first electrodes 106 are extended in the horizontal direction in parallel to each other at a predetermined interval. A first lead wiring 103 connected to the first electrode 106 is formed at the right end or the left end of the display area. In FIG. 2, six first routing wirings 103 connected to each of the six first electrodes 106 are formed. The number of the first electrodes 106 and the first routing wirings 103 is not limited to this.

  The first routing wiring 103 is formed of the same transparent conductive film such as ITO as the first electrode 106. That is, the first routing wiring 103 is extended from the first electrode 106. A connection terminal (not shown) formed at the end of the first routing wiring 103 is connected to one connection terminal (not shown) of the FPC wiring 111 formed on the FPC 110 via an anisotropic conductive adhesive. Has been. The other connection terminal (not shown) of the FPC wiring 111 formed on the FPC 110 is connected to the connection terminal (not shown) formed at the end of the auxiliary wiring 104 on the second substrate 102 via an anisotropic conductive adhesive. (Not shown).

  On the other hand, on the second substrate 102, a plurality of second electrodes 107 are extended in the vertical direction in parallel to each other at a predetermined interval. A second lead wiring 108 connected to the second electrode 107 is formed at the lower end of the display area. In FIG. 2, eight second routing wires 108 connected to each of the eight second electrodes 107 are formed. Note that the number of the second electrodes 107 and the second routing wirings 108 is not limited to this.

  Here, assuming that the wiring connecting the first electrode 106 and the driver IC 105 is the first connection wiring, the first connection wiring includes the first lead wiring 103, the FPC wiring 111, and the auxiliary wiring 104. That is, the FPC wiring 111 that is a part of the first connection wiring is formed outside the first substrate 101 and the second substrate 102. On the other hand, when the wiring that connects the second electrode 107 and the driver IC 105 is the second connection wiring, the second connection wiring is constituted only by the second lead wiring 108.

  The FPC 110 is a so-called double-sided wiring FPC having connection terminals on both outer side surfaces. Here, the FPC 110 is connected to the auxiliary wiring 104 on the surface opposite to the surface connected to the first routing wiring 103. That is, the double-sided FPC 110 also has the function of the transfer 9 in FIG. In the present embodiment, the FPC 110 is used instead of routing the first routing wiring 103 from the first electrode 106 in the frame region of the first substrate 101 and the second substrate 102. Since the FPC 110 can be bent toward the backlight unit 200, the frame can be narrowed.

Embodiment 2
Next, an embodiment different from the liquid crystal display device of the first embodiment will be described. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted as appropriate.

  FIG. 3 is a plan view showing the configuration of the liquid crystal panel 100 used in the liquid crystal display device according to the second embodiment. In the liquid crystal panel 100 used in the liquid crystal display device according to the second embodiment, in order to move the first routing wiring 103 extending from the first electrode 106 on the first substrate 101 onto the second substrate 102, The difference from the first embodiment is that a transfer 109 is formed. Therefore, the point that the auxiliary wiring 113 for connecting the FPC 110 to the second substrate is formed is also different.

  The first routing wiring 103 on the first substrate 101 is connected to the auxiliary wiring 113 on the second substrate via the transfer 109. A connection terminal (not shown) formed at the end of the auxiliary wiring 113 is connected to one connection terminal (not shown) of the FPC wiring 111 formed on the FPC 110 through an anisotropic conductive adhesive. . The other connection terminal (not shown) of the FPC wiring 111 formed on the FPC 110 is connected to the connection terminal (not shown) formed at the end of the auxiliary wiring 104 on the second substrate 102 via an anisotropic conductive adhesive. (Not shown).

  Hereinafter, a specific configuration of the transfer 109 will be described. A transfer pad formed at one end of the first routing wiring 103 on the first substrate 101 and a transfer pad formed at one end of the auxiliary wiring 113 on the second substrate 102 are arranged to face each other. The pair of transfer pads are electrically connected by a conductive material. Therefore, the first routing wiring 103 is formed on the first substrate 101 from the end of the first electrode 106 to the transfer pad, and the auxiliary wiring 113 is formed on the second substrate 102 from the transfer pad to the end of the second substrate 102. Has been.

  Here, assuming that the wiring connecting the first electrode 106 and the driver IC 105 is the first connection wiring, in the second embodiment, the first connection wiring is the first extraction wiring 103, the transfer 109, the auxiliary wiring 113, and the FPC wiring. 111 and auxiliary wiring 104. That is, the FPC wiring 111 that is a part of the first connection wiring is formed outside the first substrate 101 and the second substrate 102. On the other hand, if the wiring connecting the second electrode 107 and the driver IC 105 is the second connection wiring, the second connection wiring is configured only by the second lead wiring 108 in the second embodiment as well.

  By providing the transfer 109, a single-sided FPC in which wiring is formed only on one side can be used as the FPC 110. Further, as in the first embodiment, the FPC 110 is used instead of routing the first routing wiring 103 from the first electrode 106 in the frame regions of the first substrate 101 and the second substrate 102. Since the FPC 110 can be bent toward the backlight unit 200, the frame can be narrowed.

  Further, instead of the two FPCs 110, one printed board 113 shown in FIG. 4 may be used. In this case, the printed circuit board 113 is disposed on the back side of the backlight unit 200, that is, on the non-viewing side. Also in this case, the auxiliary wiring 104 on the second substrate and the auxiliary wiring 113 on the second substrate are connected via the FPC wiring 111 formed on the printed circuit board 113.

  The printed circuit board 113 may be either an FPC or a hard printed circuit board. When the printed circuit board 113 is an FPC, an anisotropic conductive adhesive is used for the connection between the connection terminal (not shown) of the FPC wiring 111 and the connection terminal (not shown) of the auxiliary wiring 104 and the auxiliary wiring 113 as described above. Can be used. Further, when the printed circuit board 113 is a hard printed circuit board, it is particularly preferable to press-contact using zebra rubber which is a kind of anisotropic conductive material. Even when the printed circuit board 113 is used, the first routing wiring 103 from the first electrode 106 is not routed in the frame regions of the first substrate 101 and the second substrate 102 as in the first embodiment. And since this printed circuit board 113 is arrange | positioned in the back surface of the backlight unit 200, it can narrow a frame.

1 is a cross-sectional view illustrating a configuration of a liquid crystal display device according to Embodiment 1. FIG. 4 is a plan view showing a configuration of a liquid crystal panel according to Embodiment 1. FIG. 6 is a plan view showing a configuration of a liquid crystal panel according to Embodiment 2. FIG. 6 is a plan view showing a configuration of a printed circuit board used in a liquid crystal panel according to Embodiment 3. FIG. It is a top view which shows the structure of the conventional liquid crystal panel.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,101 1st board | substrate 2,102 2nd board | substrate 3,103 1st routing wiring 4,104,113 Auxiliary wiring 5,105 Driver IC
6, 106 First electrode 7, 107 Second electrode 8, 108 Second routing wiring 9, 109 Transfer 10, 100 Liquid crystal panel 110 FPC
111 FPC wiring 112 External connection wiring 113 Printed circuit board 130 Sealing material 131 Liquid crystal 132 Spacer 133 Alignment film 134 Polarizing plate 200 Backlight unit

Claims (3)

A first electrode formed on the first transparent substrate;
A second electrode formed on the second transparent substrate and disposed to intersect the first electrode;
A driving semiconductor element mounted on the second transparent substrate;
A first connection wiring connecting the first electrode and the driving semiconductor element;
A liquid crystal display device comprising a second connection wiring for connecting the second electrode and the driving semiconductor element,
A liquid crystal display device in which part or all of the first connection wiring is disposed outside the first and second transparent substrates.   The liquid crystal display device according to claim 1, wherein the first connection wiring disposed outside the first and second transparent substrates is formed on a flexible printed circuit board.   The liquid crystal display device according to claim 2, wherein the flexible printed circuit board is a double-sided wiring flexible printed circuit board.

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