WO2007069582A1

WO2007069582A1 - Liquid crystal display device

Info

Publication number: WO2007069582A1
Application number: PCT/JP2006/324719
Authority: WO
Inventors: Kazuyuki Hiratsuka
Original assignee: Rohm Co., Ltd.
Priority date: 2005-12-14
Filing date: 2006-12-12
Publication date: 2007-06-21
Also published as: JP2007163844A

Abstract

A liquid crystal display device (A1) includes: a pair of substrates (1A, 1B) arranged to oppose to each other; a liquid crystal layer sandwiched by the pair of substrates (1A, 1B); a plurality of common electrodes (3) arranged on an opposing surface of the substrate (1B); a plurality of segment electrodes (2) arranged on an opposing surface of the substrate (1A) and orthogonally intersecting the common electrodes (3); a plurality of common wires (6) electrically connected to the common electrodes (3); a plurality of segment wires (5) electrically connected to the segment electrodes (2); and an IC chip (7) for controlling the electrical connection of the common electrodes (3) and the segment electrodes (2) so as to control the polarized state of the liquid crystal layer. The IC chip (7) is arranged at the side where the common wires (6) extend from the liquid crystal layer.

Description

Specification

Liquid crystal display

Technical field

TECHNICAL FIELD [0001] The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device having an elongated display region used for display of a sub-display of a mobile phone, a small music player, a headset, and the like.

Background art

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 arranged 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 for each pixel can be controlled, and a desired character or picture is displayed in the display area 97.

However, in recent mobile phone sub-displays, small music players, headsets, and the like, it is preferred that the display area 97 be elongated as a means of realizing a characteristic aesthetic appearance. A variety of information is being developed. In order to cope with such a sub-display, a small music player, and a headset of a mobile phone, the liquid crystal display device X needs to be downsized and display high definition. [0004] 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 portion surrounding the display area 97 in the liquid crystal display device X becomes large. Also, the 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 board 96 is required in addition to the space for accommodating the substrate 91A. Therefore, even if the display area 97 is elongated, it is difficult to reduce the size of the small music player.

[0005] In addition, the number of the plurality of segment electrodes 92 increases as the display area 97 becomes longer in the horizontal direction in FIG. 6 and as the display becomes higher in definition. For this reason, the number of pixels that each common electrode 93 should bear increases. Since each common wiring 95 is provided so as to wrap around the display area 97, its length 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.

[0006] Patent Document 1: JP 2001-13885 A

Disclosure of the invention

[0007] The present invention has been conceived under the circumstances described above, and it is an object of the present invention to provide a liquid crystal display device capable of reducing the display area and improving the image quality. To do.

[0008] A liquid crystal display device provided by the present invention is arranged on a pair of opposed substrates, a liquid crystal layer sandwiched between the pair of substrates, and one opposed surface of the pair of substrates. A plurality of common electrodes, a plurality of segment electrodes that are arranged on the other facing surface of the pair of substrates and orthogonal to the plurality of common electrodes, and a plurality of common wirings that are electrically connected to the plurality of common electrodes. An IC chip for controlling the deflection state of the liquid crystal layer by controlling the conduction state of the plurality of segment electrodes connected to the plurality of segment electrodes and the plurality of common electrodes and the plurality of segment electrodes 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.

[0009] In a preferred embodiment of the present invention, the liquid crystal layer includes the plurality of common electrodes. The dimension in the arrangement direction of the plurality of segment electrodes is larger than the dimension in the arrangement direction.

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.

[0011] In a preferred embodiment of the present invention, the plurality of segment wirings extend on both sides of the liquid crystal layer.

Brief Description of Drawings

FIG. 1 is a plan view showing a first embodiment of a liquid crystal display device according to the present invention.

FIG. 2 is a cross-sectional view of a principal part taken along line II-II in FIG.

FIG. 3 is a plan view showing a second embodiment of the liquid crystal display device according to the present invention.

FIG. 4 is a plan view showing a third embodiment of the liquid crystal display device according to the present invention.

FIG. 5 is a plan view showing a fourth embodiment of a liquid crystal display device according to the present invention.

FIG. 6 is a plan view showing an example of a conventional liquid crystal display device.

BEST MODE FOR CARRYING OUT THE INVENTION

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

FIG. 1 and FIG. 2 show a first embodiment of a liquid crystal display device according to the present invention. The liquid crystal display device A1 of this 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, and an IC chip 7. The display area 8 and the light shielding / protecting resin 71 are provided. The liquid crystal display device A1 is used for, for example, a sub-display of a mobile phone or a music information display of a small music player whose entire length is narrowed. For example, information arranged in a slender shape such as character information extending over two lines. Is displayed. In FIG. 1, the light shielding and protective resin 71 is omitted.

[0015] As shown in FIG. 1, the pair of substrates 1A and 1B have a horizontally-long rectangular shape with the left-right direction in the drawing as the longitudinal direction, and are, for example, transparent substrates having glass power. As shown in FIG. 2, the pair of substrates 1A and 1B are arranged to face each other. The substrate 1A has a plurality of segment electrodes 2 formed on its opposite surface, and is called a segment substrate. The substrate 1B has a plurality of common electrodes 3 formed on its opposite surface, and is called a common substrate. [0016] 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 left-right direction in FIG. 1 on the opposing surface of the substrate 1A. The segment electrode 2 is a transparent electrode capable of transmitting visible light, and is formed, for example, by forming a pattern on 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 the drawing in FIG. 1, and is arranged in the up-down direction in the drawing in FIG. 1 on the opposing surface of the base plate 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.

[0018] As shown in FIG. 2, the liquid crystal layer 4 is sandwiched between a pair of substrates 1A and 1B, and controls transmission of light in the vertical direction in the figure by locally switching the deflection state. belongs to. 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 member 43 in a region between a pair of substrates 1A and 1B. The facing 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 deflection direction of the liquid crystal material in a state in which no voltage is applied to the liquid crystal layer 4, and fine grooves are formed on the surface by so-called rubbing treatment. . On the other hand, the non-facing surfaces of the pair of substrates 1A and 1B are covered with the polarizing film 42, respectively.

[0019] The display area 8 is an area in which 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 43. The display area 8 includes a plurality of the above-mentioned pixels, and the number of pixels is obtained by multiplying the number of the plurality of segment electrodes 2 and the number of the plurality of common electrodes 3. It should be noted that the number of the plurality of segment electrodes 2 is greater than the number of the plurality of common electrodes 3 in accordance with the horizontally long shape of the 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, for example, by patterning the ITO film. As shown in FIG. 1, the plurality of segment wirings 5 are arranged above the plurality of segment electrodes 2 in the figure. And those extending downward in the figure. 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 wirings 6 are made of, for example, an ITO film like the segment wirings 5. As shown in FIG. 1, the plurality of common wirings 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 opposing surface of the substrate 1B. On the other hand, the portion of the common wiring 6 connected to the IC chip 7 is formed on the substrate 1A. These parts 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. IC chip 7 is mounted on substrate 1A. Accordingly, 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 control means (not shown) outside the liquid crystal display device A1, and are used, for example, for connecting a thin cable C.

[0023] As shown in FIG. 2, the IC chip 7, the plurality of segment wirings 5 (not shown in FIG. 2), the plurality of common wirings 6, and the plurality of terminals 11 are anisotropic. They are connected by a conductive adhesive film 72. The IC chip 7 is covered with a light-shielding 'protective resin 71. The light shielding / protective resin 71 is made of a resin that does not transmit visible light, etc., and is intended to prevent malfunction caused by light incident on the active surface of the IC chip 7 and protects the transparent electrode. Is. A light shielding film 73 is affixed to the lower portion of the lower surface of the substrate 1A in the figure of the IC chip 7. The light shielding film 73 is for preventing light from below in the figure of the substrate 1A from entering the active surface of the IC chip 7. A reinforcing grease 74 is provided at the connection between the board 1A and the cable. Reinforced resin 74 is bent in cable C This is to avoid damaging a portion that is easily bent.

[0024] To perform image display by the liquid crystal display device A1, a passive matrix scanning is performed by the IC chip 7. By the IC chip 7, the plurality of common electrodes 3 are sequentially brought into conduction through the plurality of common wires 6. This conduction is performed in synchronization with the scanning frequency determined by the so-called frame frequency. When a certain common electrode 3 becomes conductive, the conductive states of the plurality of segment electrodes 2 for turning on or off the pixels on the common electrode 3 are individually set. The conduction state is set in synchronization with the scanning frequency by the IC chip 7 via the plurality of segment wirings 5. In this way, when the image is displayed 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, since the IC chip 7 and the cable C are arranged on the side of the display area 8 in the figure, the upper and lower sides of the display area 8 in the figure. Needs to have a space for providing a plurality of segment wirings 5. Therefore, it is possible to reduce the vertical dimension of the liquid crystal display device A 1 in the drawing. Accordingly, it is possible to reduce the size of the sub-display, the small music player, the headset, and the like of the mobile phone equipped with the liquid crystal display device A1. In particular, it is suitable for elongating a small music player or headset. Furthermore, by taking out the plurality of segment wirings 5 in the display area 8 in the figure on both the upper and lower sides in the figure, the upper and lower one side parts in the figure with respect to the display area 8 of the liquid crystal display device A1 will not become unduly large.

As shown in FIG. 1, a plurality of segment wirings 5 and a plurality of common wirings 6 are not connected to the upper side and the lower side of the IC chip 7 in the figure, and a connection part to the terminal 11 is also provided. Absent. For this reason, the long side dimension of the IC chip 7 can be made equal to the vertical width dimension in the drawing of the substrate 1A, for example. When the long side dimension of the IC chip 7 is increased, the number of the segment wirings 5 and the plurality of common wirings 6 can be increased. Therefore, it is suitable for increasing the definition of the image displayed in the display area 8. However, even when a plurality of segment wirings 5 and a plurality of common wirings 6 are connected to the upper side and the lower side of the IC chip 7 in the drawing, there is an effect of reducing the vertical dimension of the liquid crystal display device A1 in the drawing. It is not affected by the wiring of the IC and can be reduced (not shown).

[0028] By making the common wiring 6 relatively short, the electric resistance of the common wiring 6 can be reduced. As a result, voltage can be efficiently applied to a large number of pixels by one common wiring 6. That is, when a voltage is applied to a large number of pixels at the same time, the voltage drop in the common wiring 6 is too large. 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 the plurality of segment electrodes 2 increases corresponding to the horizontally long display region 8. However, according to the common wiring 6 having a small voltage drop, an appropriate voltage can be simultaneously applied to such a large number of segment electrodes 2. This is advantageous for high definition of the image displayed in the display area 8.

[0030] Figures 3-5 illustrate 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. In the liquid crystal display device A2 of this embodiment, the arrangement of the terminals 11 with respect to the IC chip 7 is different from the above-described embodiment. As shown in the figure, the terminal 11 also extends the lower side force 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 arranged on the upper side of the substrate 1A in the drawing.

[0032] According to such an embodiment, it is possible to reduce the horizontal dimension corresponding to the longitudinal direction of the liquid crystal display device A2 as well as the vertical dimension. Thereby, further miniaturization of the sub-display of the portable telephone or the small music player and the headset can be achieved. The cable C connected to such a liquid crystal display device A2 preferably has a shape bent at a right angle to the connection force with the terminal 11.

FIG. 4 shows a third embodiment of the liquid crystal display device according to the present invention. In the liquid crystal display device A3 of the present embodiment, the mounting form of the IC chip 7 is different from any of the above-described embodiments. 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 A part of the segment wiring 5 and the plurality of common wirings 6 are formed. As will be understood, the liquid crystal display device according to the present invention is not limited to the COG format described above, 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 this embodiment is in the COG format and has the same force as the liquid crystal display devices Al and A2 described above. Connection positions of the plurality of segment wirings 5 and the plurality of common wirings 6 to the IC chip 7 Is different from these embodiments. As shown in FIG. 5, a plurality of segment wirings 5 are provided in 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 in the vertical direction of the IC chip 7 in the drawing. And a portion extending obliquely upward. On the other hand, the plurality of common wirings 6 extend to the upper part of the lower right side IC chip 7 in the right side of the display area 8 in the figure and the upper side component IC chip of the right side of the display area 8 in the figure. It is divided into those that pass through 7 and extend to the lower part of the IC chip 7. As a result, the IC chip 7 of the present embodiment is configured such that a plurality of segment wirings 5 are connected near the center of the left long side, and a plurality of common wirings 6 are connected near both ends of the left long side. . Also in such an embodiment, the vertical dimension in the figure 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.

Claims

The scope of the claims

[1] a pair of substrates placed opposite each other,

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 conducting to the plurality of common electrodes;

A plurality of segment wirings conducting 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.

[2] 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. .

[3] 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.

[4] The liquid crystal display device according to any one of claims 1 to 3, wherein the plurality of segment wirings extend from both sides of the liquid crystal layer! /.