JP2007163844A - Liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device capable of elongating a display region and improving image quality. <P>SOLUTION: A liquid crystal display device A1 includes a pair of substrates 1A and 1B disposed in opposition to each other, a liquid crystal layer interposed between the pair of substrates 1A and 1B, a plurality of common electrodes 3 arrayed on a face opposite to the substrate 1B, a plurality of segment electrodes 2 which are arrayed on a face opposite to the substrate 1A and cross the plurality of common electrodes 3 at right angles, a plurality of common wires 6 conductive to the plurality of common electrodes 3, a plurality of segment wires 5 conductive to the plurality of segment electrodes 2, and an IC chip 7 which controls a deflection state of the liquid crystal layer by controlling conductive states of the plurality of common electrodes 3 and the plurality of segment electrodes 2. The IC chip 7 is disposed on the side to which the common wires 6 are extended outward from the liquid crystal layer, to the liquid crystal layer. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device having an elongated display area used for display of a portable phone or a small music player.

  FIG. 6 shows an example of a conventional liquid crystal display device. The liquid crystal display device X shown in the figure is configured to display characters and pictures in a horizontally long display area 97. The liquid crystal display device X has a pair of substrates 91A and 91B. The pair of substrates 91A and 91B are disposed to face each other. A plurality of segment electrodes 92 are arranged on the opposing surface of the substrate 91A. A plurality of common electrodes 93 are arranged on the opposing surface of the substrate 91B. The segment electrode 92 and the common electrode 93 are orthogonal to each other. A liquid crystal layer (not shown) is interposed between the plurality of segment electrodes 92 and the plurality of common electrodes 93. A plurality of segment wirings 94 are connected to the plurality of segment electrodes 92. A plurality of common wires 95 are connected to the plurality of common electrodes 93. The plurality of segment wirings 94 and the plurality of common wirings 95 extend to the flexible wiring board 96. In the liquid crystal display device X, the deflection state of the liquid crystal layer is locally switched by scanning the plurality of segment electrodes 92 and the plurality of common electrodes 93 by the passive matrix method. The local deflection state of the liquid crystal layer is switched for each pixel constituting the display area 97. As a result, the light emission state of each pixel can be controlled, and a desired character or picture is displayed in the display area 97.

  However, in recent portable telephones and small music players, it is preferred that the display area 97 is elongated as a means for realizing a characteristic aesthetic appearance, and information to be displayed is diversified. In order to deal with such a portable phone and a small music player, the liquid crystal display device X is required to be downsized and display high definition. When the definition is increased, the number of the plurality of segment wirings 94 and the plurality of common wirings 95 increases. For this reason, the dimension of the part surrounding the display area 97 in the liquid crystal display device X is increased. Moreover, a flexible wiring board 96 is provided so as to extend downward in the drawing. In order to mount the liquid crystal display device X in, for example, a small music player, a space for accommodating the flexible wiring substrate 96 is required in addition to a space for accommodating the substrate 91A. Therefore, even if the display area 97 is elongated, it is difficult to elongate the small music player.

  In addition, as the display region 97 becomes narrower, the number of the plurality of segment electrodes 92 increases. For this reason, the number of pixels that each common electrode 93 should bear increases. Since each common line 95 is provided so as to go around the display area 97, the length thereof is relatively long. Therefore, due to the increase in electrical resistance, the power supply capability for a large number of pixels from each common wiring 95 may be insufficient. In such a case, characters and pictures displayed in the display area 97 become unclear.

JP 2001-13885 A

  The present invention has been conceived under the circumstances described above, and an object of the present invention is to provide a liquid crystal display device capable of reducing the display area and improving the image quality.

  The liquid crystal display device provided by the present invention includes a pair of substrates disposed opposite to each other, a liquid crystal layer sandwiched between the pair of substrates, and a plurality of substrates arranged on one facing surface of the pair of substrates. A plurality of segment electrodes orthogonal to the plurality of common electrodes, a plurality of common wires conducting to the plurality of common electrodes, and a plurality of the plurality of common wirings arranged on the other facing surface of the pair of substrates. A plurality of segment wirings that conduct to the segment electrodes, and an IC chip that controls the deflection state of the liquid crystal layer by controlling the conduction states of the plurality of common electrodes and the plurality of segment electrodes. In the display device, the IC chip is arranged on the side where the common wiring extends from the liquid crystal layer with respect to the liquid crystal layer.

  According to such a configuration, the dimension of the pair of substrates can be reduced on the side where the plurality of segment wirings extend with respect to the liquid crystal layer. Accordingly, it is possible to reduce the size of the liquid crystal display device in the direction in which the plurality of segment wirings extend, and it is suitable for downsizing of a portable telephone or a small music player on which the liquid crystal display device is mounted. ing. Further, the plurality of common wires can be shortened by arranging the IC chip on the side where the common wires extend. For this reason, it is possible to reduce a voltage drop in the plurality of common wirings, which is advantageous for high definition of the liquid crystal display device.

  In a preferred embodiment of the present invention, the liquid crystal layer has a dimension in the arrangement direction of the plurality of segment electrodes larger than a dimension in the arrangement direction of the plurality of common electrodes. According to such a configuration, the liquid crystal display device can be elongated.

  In a preferred embodiment of the present invention, the number of the plurality of segment electrodes is larger than the number of the plurality of common electrodes. According to such a configuration, it is possible to appropriately apply a voltage to these pixels via the common wiring while increasing the number of pixels in the direction in which the plurality of segment electrodes are arranged. Therefore, the liquid crystal display device having the horizontally long liquid crystal layer is suitable for achieving high definition in the longitudinal direction.

  In a preferred embodiment of the present invention, the plurality of segment wirings extend from both sides of the liquid crystal layer. According to such a configuration, it is possible to avoid that one of the portions sandwiching the liquid crystal layer in the liquid crystal display device is extremely bulky.

  Other features and advantages of the present invention will become more apparent from the detailed description given below with reference to the accompanying drawings.

  Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings.

  1 and 2 show a first embodiment of a liquid crystal display device according to the present invention. The liquid crystal display device A1 of the present embodiment includes a pair of substrates 1A and 1B, a plurality of segment electrodes 2, a plurality of common electrodes 3, a liquid crystal layer 4, a plurality of segment wirings 5, a plurality of common wirings 6, an IC chip 7, The display area 8 and the light shielding resin 71 are provided. The liquid crystal display device A1 is used for, for example, a rear display of a mobile phone or a music information display of a small music player which is slender as a whole, and displays slender information such as character information over two lines. It is supposed to be configured. In FIG. 1, the light shielding resin 71 is omitted.

  As shown in FIG. 1, the pair of substrates 1 </ b> A and 1 </ b> B has a horizontally long rectangular shape with the left-right direction in the drawing as a longitudinal direction, and is a transparent substrate made of glass, for example. As shown in FIG. 2, the pair of substrates 1A and 1B are disposed to face each other. The substrate 1A has a plurality of segment electrodes 2 formed on the opposite surface, and is called a segment substrate. The substrate 1B has a plurality of common electrodes 3 formed on the opposite surface, and is called a common substrate.

  Each of the plurality of segment electrodes 2 has a strip shape extending in the vertical direction in FIG. 1, and is arranged in the horizontal direction in FIG. 1 on the opposing surface of the substrate 1A. The segment electrode 2 is a transparent electrode that can transmit visible light, and is formed, for example, by patterning an ITO (Indium Tin Oxide) film.

  Each of the plurality of common electrodes 3 has a strip shape extending in the left-right direction in FIG. 1, and is arranged in the up-down direction in FIG. 1 on the opposing surface of the substrate 1B. The common electrode 3 is also a transparent electrode similar to the segment electrode 2. The intersection of each common electrode 3 and each segment electrode 2 constitutes a pixel.

  As shown in FIG. 2, the liquid crystal layer 4 is sandwiched between a pair of substrates 1A and 1B, and controls the transmission of light in the vertical direction in the figure by switching the local deflection state. is there. The liquid crystal layer 4 is a liquid crystal material (not shown) containing liquid crystal such as nematic liquid crystal in a space sealed by a seal material 42 in a region between a pair of substrates 1A and 1B. The opposing surfaces of the pair of substrates 1A and 1B are covered with an alignment film 41, respectively. The alignment film 41 is for defining the polarization direction of the liquid crystal material in a state where no voltage is applied to the liquid crystal layer 4, and fine grooves are formed on the surface thereof by so-called rabbing treatment. On the other hand, the non-opposing surfaces of the pair of substrates 1A and 1B are covered with a polarizing film 42, respectively.

  The display area 8 is an area where an image such as a character or a picture is displayed. As shown in FIG. 1, the display area 8 has a horizontally long shape located near the center of the substrate 1B. This shape corresponds to the outer shape of the liquid crystal layer 4 surrounded by the seal member 42. The display area 8 includes a plurality of the pixels, and the number of pixels is obtained by multiplying the number of the segment electrodes 2 and the number of the common electrodes 3. Note that the number of the plurality of segment electrodes 2 is greater than the number of the plurality of common electrodes 3 corresponding to the horizontally long display region 8.

  The plurality of segment wirings 5 are connected to the plurality of segment electrodes 2 and are used for voltage application to the liquid crystal layer 4 by the plurality of segment electrodes 2. The plurality of segment wirings 5 are formed on the opposing surface of the substrate 1A by patterning the ITO film, for example. As shown in FIG. 1, the plurality of segment wires 5 are divided into a plurality of segment electrodes 2 that extend upward in the drawing and a portion that extends downward in the drawing. As can be understood from FIG. 1, the plurality of segment wirings 5 extend to the IC chip 7 so as to wrap around the display area 8.

  The plurality of common wires 6 are connected to the plurality of common electrodes 3, and are used for voltage application to the liquid crystal layer 4 by the plurality of common electrodes 3. The plurality of common wires 6 are made of, for example, an ITO film in the same manner as the segment wires 5. As shown in FIG. 1, the plurality of common wires 6 extend from the display area 8 to the IC chip 7 through a relatively straight and short path. A portion of the common wiring 6 connected to the common electrode 3 is formed on the facing surface of the substrate 1B. On the other hand, a portion of the common wiring 6 connected to the IC chip 7 is formed on the substrate 1A. These portions are electrically connected by a conductive member (not shown) near the right end of the substrate 1B in FIG.

  The IC chip 7 is for performing drive control for displaying a desired image in the display area 8, and includes, for example, a semiconductor having an active surface in which a fine circuit is formed. The IC chip 7 is mounted on the substrate 1A. Thus, the liquid crystal display device A1 is configured as a so-called COG (chip on glass) type liquid crystal display device. A plurality of segment wirings 5 and a plurality of common wirings 6 are connected to the IC chip 7 from the left side in FIG. A plurality of terminals 11 extend on the substrate 1A from the right side of the IC chip 7 in the drawing. The plurality of terminals 11 are portions for receiving signals from a control means (not shown) outside the liquid crystal display device A1, and are used for connecting a thin cable C, for example. As shown in FIG. 2, the IC chip 7, the plurality of segment wirings 5, the plurality of common wirings 6, and the plurality of terminals 11 are connected by an anisotropic conductive adhesive film 72. The IC chip 7 is covered with a light shielding resin 71. The light shielding resin 71 is made of a resin that does not transmit visible light or the like, and is intended to prevent malfunction caused by light incident on the active surface of the IC chip 7. A light shielding film 73 is attached to the lower surface of the substrate 1A in the drawing. The light shielding film 73 is for preventing light from the lower side of the substrate 1 </ b> A from entering the active surface of the IC chip 7. A reinforcing resin 74 is provided at a connection portion between the substrate 1A and the cable C. The reinforcing resin 74 is for avoiding breakage of the easily bent portion of the cable C.

  In order to perform image display by the liquid crystal display device A1, passive matrix scanning is performed by the IC chip 7. The plurality of common electrodes 3 are sequentially rendered conductive by the IC chip 7 via the plurality of common wires 6. This conduction is performed in synchronization with a scanning frequency determined by a so-called frame frequency. When a certain common electrode 3 becomes conductive, the conductive states of the plurality of segment electrodes 2 are individually set so that the pixels on the common electrode 3 are turned on or off. This conduction state is set in synchronization with the scanning frequency by the IC chip 7 via the plurality of segment wirings 5. As described above, in the display of an image by the liquid crystal display device A1, voltage application by the common electrode 3 is simultaneously performed on a plurality of pixels arranged in the horizontal direction in FIG.

  Next, the operation of the liquid crystal display device A1 will be described.

  According to the present embodiment, as shown in FIG. 1, the IC chip 7 and the cable C are arranged on the side of the display area 8 in the figure, so that It is sufficient if there is a space for providing a plurality of segment wirings 5. Therefore, the vertical dimension of the liquid crystal display device A1 in the drawing can be reduced. Therefore, it is possible to reduce the size of a mobile phone or a small music player on which the liquid crystal display device A1 is mounted. In particular, it is suitable for making a small music player slender. Further, by taking out the plurality of segment wirings 5 from both sides of the display area 8, one side portion of the liquid crystal display device A1 with respect to the display area 8 is not unduly enlarged.

  As shown in FIG. 1, a plurality of segment wirings 5 and a plurality of common wirings 6 are not inserted into the upper side and the lower side of the IC chip 7 in the drawing, and a connection portion with the terminal 11 is not provided. For this reason, the long side dimension of the IC chip 7 can be made equal to, for example, the width dimension of the substrate 1A. When the long side dimension of the IC chip 7 is increased, the number of the plurality of segment wirings 5 and the plurality of common wirings 6 can be increased. Therefore, it is suitable for reducing the size of the liquid crystal display device A1 and increasing the definition of the image displayed in the display area 8.

  By making the common wiring 6 relatively short, the electric resistance of the common wiring 6 can be reduced. Thereby, it is possible to efficiently apply a voltage to a large number of pixels by one common wiring 6. That is, it is possible to avoid a problem that the voltage application is insufficient due to the voltage drop in the common wiring 6 being excessively large as compared with the case where the voltage is simultaneously applied to a large number of pixels. Therefore, it is suitable for improving the image quality of the liquid crystal display device A1.

  In particular, in the present embodiment, the number of segment electrodes 2 is increased corresponding to the horizontally long display area 8. However, according to the common wiring 6 having a small voltage drop, it is possible to simultaneously apply an appropriate voltage to such a large number of segment electrodes 2. This is advantageous for high definition of the image displayed in the display area 8.

  3 to 5 show other embodiments of the present invention. In these drawings, the same or similar elements as those in the above embodiment are denoted by the same reference numerals as those in the above embodiment.

  FIG. 3 shows a second embodiment of the liquid crystal display device according to the present invention. The liquid crystal display device A2 of this embodiment is different from the above-described embodiment in the arrangement of the terminals 11 with respect to the IC chip 7. As shown in the figure, the terminal 11 extends from the lower side of the IC chip 7 in the figure. Further, in order to secure the space for arranging the terminals 11, the IC chip 7 is disposed closer to the upper side of the substrate 1 </ b> A in the figure.

  According to such an embodiment, not only the vertical dimension of the liquid crystal display device A2, but also the horizontal dimension corresponding to the longitudinal direction can be reduced. Thereby, further miniaturization of a mobile phone or a small music player can be achieved. As the cable C connected to such a liquid crystal display device A2, a cable that is bent at a right angle from the connection portion with the terminal 11 is preferable.

  FIG. 4 shows a third embodiment of the liquid crystal display device according to the present invention. The liquid crystal display device A3 of the present embodiment is different from any of the above-described embodiments in the mounting format of the IC chip 7. In the present embodiment, the IC chip 7 is mounted on the flexible wiring board 12. The flexible wiring board 12 is bonded to the end of the board 1A, and a plurality of segment wirings 5 and a part of the plurality of common wirings 6 are formed. As understood from the present embodiment, the liquid crystal display device according to the present invention is not limited to the above-described COG format, but may be configured as a COF (chip on film) format as in the present embodiment.

  FIG. 5 shows a fourth embodiment of the liquid crystal display device according to the present invention. The liquid crystal display device A4 of the present embodiment is common to the liquid crystal display devices A1 and A2 described above in that it is in the COG format, but the plurality of segment wirings 5 and the plurality of common wirings 6 are connected to the IC chip 7. The position is different from these embodiments. As shown in FIG. 5, the plurality of segment wirings 5 are provided at a portion extending below the display area 8, a portion extending rightward in the drawing from this portion, and a portion closer to the center of the IC chip 7 in the vertical direction in the drawing. And a portion extending obliquely upward. On the other hand, the plurality of common lines 6 extend from the lower part of the display area 8 to the upper part of the IC chip 7 and the lower part of the IC chip 7 passes through the IC chip 7 from the upper part of the display area 8. It is divided into what extends to. As a result, the IC chip 7 of the present embodiment is configured such that a plurality of segment wirings 5 enter near the center of the left long side, and a plurality of common wirings 6 enter near both ends of the left long side. Also in such an embodiment, the vertical dimension in the drawing of the liquid crystal display device A4 can be reduced.

  The liquid crystal display device according to the present invention is not limited to the above-described embodiment. The specific configuration of each part of the liquid crystal display device according to the present invention can be varied in design in various ways.

1 is a plan view showing a first embodiment of a liquid crystal display device according to the present invention. It is principal part sectional drawing in alignment with the II-II line of FIG. It is a top view which shows 2nd Embodiment of the liquid crystal display device which concerns on this invention. It is a top view which shows 3rd Embodiment of the liquid crystal display device which concerns on this invention. It is a top view which shows 4th Embodiment of the liquid crystal display device which concerns on this invention. It is a top view which shows an example of the conventional liquid crystal display device.

Explanation of symbols

A1, A2, A3, A4 Liquid crystal display devices 1A, 1B Substrate 2 Segment electrode 3 Common electrode 4 Liquid crystal layer 5 Segment wiring 6 Common wiring 7 IC chip 8 Display area 11 Terminal 12 Flexible wiring board

Claims (4)

A pair of opposed substrates;
A liquid crystal layer sandwiched between the pair of substrates,
A plurality of common electrodes arranged on one opposing surface of the pair of substrates;
A plurality of segment electrodes arranged on the other facing surface of the pair of substrates and orthogonal to the plurality of common electrodes;
A plurality of common wires connected to the plurality of common electrodes;
A plurality of segment wires connected to the plurality of segment electrodes;
An IC chip for controlling a deflection state of the liquid crystal layer by controlling a conduction state of the plurality of common electrodes and the plurality of segment electrodes, and a liquid crystal display device comprising:
The liquid crystal display device, wherein the IC chip is disposed on a side where the common wiring extends from the liquid crystal layer with respect to the liquid crystal layer.   The liquid crystal display device according to claim 1, wherein the liquid crystal layer has a dimension in the arrangement direction of the plurality of segment electrodes larger than a dimension in the arrangement direction of the plurality of common electrodes.   The liquid crystal display device according to claim 1, wherein the number of the plurality of segment electrodes is larger than the number of the plurality of common electrodes.   The liquid crystal display device according to claim 1, wherein the plurality of segment wirings extend from both sides of the liquid crystal layer.

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