JP2003222896A - Liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal panel and a liquid crystal display device of which the display quality is improved by reducing wiring pattern resistance at a low cost and the frame narrowing is achieved at the same time. <P>SOLUTION: In a liquid crystal panel 13, a wiring pattern 17 for connecting a common side electrode group 11 with a common transparent electrode group 4 is formed using a translucent film necessary for forming a translucent type liquid crystal panel. <P>COPYRIGHT: (C)2003,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device provided with a semi-transmissive film and used for both a reflection type and a transmission type. The present invention relates to a liquid crystal display device in which, for example, connection terminals for connecting semiconductor elements are formed along one side or two opposite sides of a display region. 2. Description of the Related Art In recent years, liquid crystal display devices have been further miniaturized,
Cost reduction has been demanded, and conventionally, according to the STN-type liquid crystal display device, two components for the segment and the common are used.
A liquid crystal display device is configured using two driver ICs, but a liquid crystal display device is configured using one driver IC having both a segment function and a common function. It is desired that the cost be reduced. FIG. 8 shows a liquid crystal panel formed by one driver IC. FIG. 1 is a plan view of a main part of a liquid crystal display device including such a liquid crystal panel. The liquid crystal panel 1 has a structure in which a small-sized glass substrate 2 and a large-sized glass substrate 3 are bonded together, and a wiring pattern and a transparent electrode group are formed on both glass substrates. In FIG. 1, the one formed on the glass substrate 2 is indicated by a solid line, and the one formed on the glass substrate 3 is indicated by a broken line. Hereinafter, the wiring structure of the liquid crystal panel 1 will be described. A transparent electrode group for common 4 made of ITO (indium tin oxide) and a wiring pattern 5 extending from the transparent electrode group for common 4 are formed on the glass substrate 2, and are formed on the other glass substrate 3. Are formed with a transparent electrode group for segment 6 made of ITO and a trapezoidal wiring pattern 7 extending from the transparent electrode group for segment 6, and a transparent electrode group for common 4 and a transparent electrode group for segment 6 are formed.
The area where .alpha. Further, a sealing resin 9 is provided around the outside of the display section 8, and the glass substrate 2 and the glass substrate 3 are bonded together with the sealing resin 9, and a liquid crystal 10 is interposed in the internal space between the two glass substrates. . A common-side electrode terminal group 11 and a segment-side electrode terminal group 12 made of ITO or the like are formed on one end side of the glass substrate 3 and connected to the wiring patterns 5 and 7, respectively. TCP (tape carrier package) and COF (chip-on-film) are thermocompression-bonded on these electrode terminal groups using an anisotropic conductive film, etc.
A liquid crystal display device is configured. Note that, in the liquid crystal panel 1 in FIG. 8, TCP and COF are not shown. Next, the common transparent electrode group 4 and the segment transparent electrode group 6 and the common side electrode terminal group 11
The connection configuration with the segment side electrode terminal group 12 will be described. First, the common transparent electrode group 4 formed on the glass substrate 2 is extended by a wiring pattern 5 made of ITO or the like toward the edge side where the common-side electrode terminal group 11 is provided. [0010] A wiring pattern 5 extending on the glass substrate 2 and a common-side electrode terminal group 1 formed on the glass substrate 3
1 is a conductive material (eg, Au-plated particles)
Is made conductive by the sealing resin 9 mixed with. On the other hand, the segment transparent electrode group 6 on the glass substrate 3 is extended by a wiring pattern 7 made of ITO or the like, and is made into a segment side electrode terminal group 12 at the end of the glass substrate 3 through the sealing resin 9. According to the liquid crystal panel 1 as described above, a liquid crystal display device can be constituted by one driver IC, and the cost of the liquid crystal display device can be reduced. However, according to the liquid crystal panel 1 having the above-described structure, the wiring pattern is formed using ITO having a higher resistivity than a metal such as aluminum. When the wiring pattern 5a is compared with the wiring pattern 5b, a difference occurs in the wiring resistance,
Even display quality cannot be obtained. To solve this problem, a wiring pattern 5
There is also a means for eliminating the difference in resistance between the wiring patterns by changing the line width of the liquid crystal panel (see Japanese Patent Application No. 2001-053186). In such a configuration, the liquid crystal panel itself is provided by providing a wiring pattern having a large line width. Frame becomes larger,
This hinders miniaturization of the liquid crystal panel. Further, when ITO is used for the wiring pattern, even if the line width is changed, the resistance difference of the wiring pattern is extremely large, and it is difficult to adjust the resistance difference only by changing the line width. Display unevenness occurs. Accordingly, it is an object of the present invention to achieve miniaturization of a liquid crystal panel at low cost and to prevent or reduce the occurrence of display unevenness, whereby the liquid crystal of a liquid crystal panel achieving a high display quality is achieved. It is to provide a display device. According to the present invention, there is provided a liquid crystal display device comprising: a semi-transmissive film made of a metal material having both light reflectivity and light transmissivity on a substrate; A liquid crystal surrounded by a seal member is formed by one member formed by forming an electrode group and an alignment film, and the other member formed by forming another transparent electrode group and an alignment film arranged in stripes on a substrate. Are bonded so that both transparent electrode groups intersect at right angles,
Further, the wiring pattern connected to the transparent electrode group on one member is made to conduct electricity to the wiring pattern on the other member, and the wiring pattern on one member is formed of a metal material of a semi-permeable film. And Further, a portable terminal or a display device according to the present invention is characterized in that the liquid crystal display device according to the present invention is provided. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a liquid crystal display device of the present invention will be described with reference to FIG.
A description will be given using a TN type simple matrix type. The device of the present invention is a semi-transmissive device using a semi-transmissive film, and uses both the light reflectivity and the light transmissivity of the semi-transmissive film when using in a reflection mode. The backlight is not turned on, and when used in the transmission mode, the backlight is turned on. (Embodiment 1) FIG. 1 is a plan view of a liquid crystal panel 13 of a liquid crystal display device of the present invention having a structure in which two glass substrates are bonded to each other, and FIG. It is sectional drawing seen from the direction of A. The same parts as those of the conventional liquid crystal panel are denoted by the same reference numerals. As shown in FIG. 1, a wiring pattern and a transparent electrode group are formed on both substrates, and those formed on a small-area glass substrate 2 are represented by solid lines and on a large-area glass substrate 3. Are indicated by broken lines. According to the wiring structure of the liquid crystal panel 13,
The liquid crystal panel 13 has a structure in which a glass substrate 2 and a glass substrate 3 are bonded together with a seal resin 9 interposed therebetween, and a liquid crystal 10 is interposed between the glass substrate 2 and the glass substrate 3. A transparent electrode group 4 for common is formed in stripes on the inner surface of the glass substrate 2 from ITO or the like, and a transparent electrode group 6 for segments formed of ITO or the like is formed on the inner surface of the glass substrate 3 in a stripe shape. Both the common transparent electrode group 4 and the segment transparent electrode group 6 are coated with an alignment film (not shown). Then, the glass substrate 2 and the glass substrate 3 are arranged such that both transparent electrode groups are orthogonal to each other.
And a region where the transparent electrode group is orthogonal to each other is defined as a display unit 8. On the glass substrate 3, a common-side electrode terminal group 11 and a segment-side electrode terminal group 12 for connecting driving elements are formed near one side edge outside the sealing resin 9. The connection configuration between these electrode terminal groups 11, 12 and the common transparent electrode group 4 and the segment transparent electrode group 6 will be described below. As shown in FIG. 2, in the transflective liquid crystal panel, a translucent film 14 made of a metal such as aluminum is formed on the inner surface of the glass substrate 2 on which the common electrode group 4 is formed. That is, the internal structure of the glass substrate 2 in the display unit 8 is such that the semi-transmissive film 14
Is formed thereon, a color filter 15 is formed thereon, an overcoat layer 16 made of a resin or an inorganic material for the purpose of insulation is formed thereon, and a common transparent electrode group forming the display unit 8 is formed thereon. 4 is formed. The transflective liquid crystal panel 13 of the present invention is a transflective film 1 formed on the inner surface of the glass substrate 2.
4, the wiring pattern 17 is formed at the same time. That is, as shown in FIG.
A semi-transmissive film is formed on one inner surface of the substrate, and the wiring pattern 17 is formed in the non-display area by patterning.
As for the semi-transmissive film 14 provided on the display section 8, a color filter 15 is formed thereon, and an overcoat layer 16 is further formed. It is desirable that the overcoat layer 16 is not formed on the wiring pattern 17 formed of a semi-transmissive film. This is because the overcoat layer 16 is electrically connected to the common transparent electrode group 4 forming the display section 8 described later. This is to achieve electrical continuity. After selectively forming the overcoat layer 16 only on the display section 8, a layer made of ITO is formed thereon to form the common transparent electrode group 4 forming the display surface 8. In forming such a common transparent electrode group 4, an ITO layer is formed not only on the display section 8 but also on a wiring pattern 17 formed of a semi-transmissive film. Thereafter, patterning is performed to form a common transparent electrode group 4 and a wiring pattern 17 formed of a semi-transmissive film.
And the continuity is established. However, in the liquid crystal panel 13 shown in FIG.
In addition to providing electrical continuity with the wiring pattern 7, an ITO layer is formed over the entire wiring pattern 17. The wiring pattern 17 made of the semi-permeable film having the ITO layer laminated as described above extends to the sealing resin 9 in the direction of the edge where the common-side electrode terminal group 11 is provided, and has a further conductive property. It is connected to the common-side electrode terminal group 11 formed on the glass substrate 3 through the sealing resin 9. The segment transparent electrode group 6 formed on the glass substrate 3 extends in the direction of the edge where the segment side electrode terminal group 12 is disposed, and passes through the seal resin 9 to form the segment side electrode terminal group. 12 is connected. A driving element is provided for the liquid crystal panel 13 having the above-described configuration to form a liquid crystal display device. For example, the liquid crystal display device 18 shown in FIG. 3 uses a TCP (tape carrier package) or COF (chip-on-film) composed of a film or the like on which a drive element (IC) 19 having both segment side and common side output functions is mounted. It is disposed at the end of the liquid crystal panel 13 and is pressure-bonded to an electrode terminal group formed near the edge of the glass substrate 3 via an anisotropic conductive film or the like. According to the liquid crystal panel 13 or the liquid crystal display device 18 having the above-described configuration, since the wiring pattern 17 is formed by the semi-transmissive film, the resistance value becomes smaller than that of the wiring pattern formed by the conventional ITO. In addition, since the resistance difference between the wiring patterns is reduced, display unevenness is eliminated and display quality is improved. Moreover, the liquid crystal panel 13 shown in FIGS.
In this case, since the ITO layer is laminated over the entire wiring pattern 17, the wiring resistance is further reduced as compared with the case where the wiring pattern is formed only by the semi-transmissive film, which is effective for improving display quality and narrowing the frame. . Also, when using means for changing the line width of the wiring pattern and eliminating display unevenness, the wiring pattern can be made thinner than in the past, so that a narrower frame can be achieved. Further, according to the present invention, when forming a wiring pattern having a small resistance, a semi-transmissive liquid crystal panel is manufactured without adding a step of forming a new metal film. The film is used for the wiring pattern. Therefore, a low-resistance wiring pattern can be formed without increasing the manufacturing cost, and as a result, a liquid crystal panel and a liquid crystal display device with high display quality can be provided. As described above, according to the present invention, a liquid crystal panel and a liquid crystal display device with low cost and high display quality can be obtained by using an existing semi-transmissive film for the wiring pattern instead of relying on the wiring pattern. Can be provided. Therefore, for example, the liquid crystal panel 1 shown in FIG.
The wiring patterns 5 provided in the two side directions are also effective for their routing. (Embodiment 2) This embodiment is shown in FIG. 4 and FIG. FIG. 4 is a plan view of the liquid crystal panel, and FIG. 5 is a sectional view of the portion b shown in FIG. Also in this liquid crystal panel 20, a wiring pattern 21 made of a semi-transmissive film is formed on the glass substrate 2. In the liquid crystal panel 13 shown in FIG. 1, the connection point between the wiring pattern 17 and the common transparent electrode group 4 is formed. Is provided near the display section 8, whereas the connection point is provided near the seal resin 9 in the liquid crystal panel 20. Hereinafter, the wiring structure of the liquid crystal panel 20 will be described. A semi-transmissive film 14 is formed on a glass substrate 2, and a color filter 15 and an overcoat layer 16 are formed thereon. However, as shown in FIG. 5, the overcoat layer is not formed at the portion c where the end of the wiring pattern is formed. An ITO layer is formed on the overcoat layer 16. At this time, an ITO layer is formed on the entire surface of the glass substrate 2 and patterned to form the common transparent electrode group 4. At a portion c in FIG. 5 where no layer is formed, conduction is established with the wiring pattern 21 formed by the semi-transmissive film. With the wiring routing and wiring structure shown in FIG. 5 as described above, it is possible to switch the scanning direction when driving the liquid crystal panel. When the driving ICs connected to the liquid crystal panel perform the same operation, the scanning directions of the common transparent electrode group 4 are opposite to each other in the liquid crystal panel 13 in FIG. 1 and the liquid crystal panel 20 in FIG. (Embodiment 3) This embodiment is shown in FIG. 6 and FIG. FIG. 6 is a plan view of the liquid crystal panel, and FIG. 7 is a cross-sectional view of part e in FIG. According to the structure of laminating the ITO layer over the entire wiring pattern 17 formed of a semi-transmissive film as shown in the first embodiment, this is a very effective means for reducing the wiring resistance. In the part d where the line width of the wiring pattern 17 is reduced, the yield in the manufacturing process may be reduced due to a short circuit between the adjacent wiring patterns, which is a concern in that respect. For example, if the resistance value is sufficiently small even if the wiring pattern is formed only with the semi-transmissive film, and there is no problem in narrowing the frame, the configuration shown in FIGS. 6 and 7 may be used. A wiring pattern 17 is formed by a semi-transmissive film, and a color filter 15 and an overcoat layer 16 are formed thereon. At this time, the overcoat layer is not formed on the wiring pattern 17. Further, an ITO layer for forming the common transparent electrode 4 is formed on the overcoat layer 16. At this time, the ITO layer is not formed in the region d of the wiring pattern 17. That is, as shown in FIG. 6 and FIG.
The common transparent electrode group 4 made of O and the wiring pattern 17 made of a semi-transmissive film are connected at the end of the wiring pattern 17 on the display unit side. As described above, since the wiring pattern 17 made of a semi-transmissive film and the ITO film are not laminated at the narrow pitch d in FIG. 6, a liquid crystal panel with a high yield can be produced. The present invention is not limited to the above embodiment, and various changes and improvements may be made without departing from the gist of the present invention. For example, according to the embodiment of the present invention, an STN-type liquid crystal display device using one driver IC having both a function for a segment and a function for a common is used. It may be provided or an active type such as a TFT. As described above, according to the semi-transmissive liquid crystal display device of the present invention, aluminum can be formed without adding a step of forming a new metal film in order to form a wiring pattern with low resistance. A semi-transmissive film made of such a metal is used for the wiring pattern, whereby a low-resistance wiring pattern can be formed without increasing the manufacturing cost. Further, according to the present invention, the wiring pattern made of the semi-transmissive film has a lower resistance than the conventionally used wiring pattern made of ITO, so that the display quality of the liquid crystal panel can be improved, and A narrower frame could be achieved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of a liquid crystal panel of the present invention. FIG. 2 is a cross-sectional view of a portion a in FIG. FIG. 3 is a plan view of the liquid crystal display device of the present invention. FIG. 4 is a plan view of another liquid crystal panel of the present invention. FIG. 5 is a cross-sectional view of part b in FIG. 4 as viewed from the direction of arrow A. FIG. 6 is a plan view of still another liquid crystal panel of the present invention. FIG. 7 is a cross-sectional view of part e in FIG. 6 as seen from the direction of arrow A. FIG. 8 is a plan view of a conventional liquid crystal panel. [Description of Signs] 1, 13, 20, 22 ... Liquid crystal panel 2 ... Glass substrate 3 ... Glass substrate 4 ... Common transparent electrode group 5, 5a, 5b, 7 ... Wiring pattern 6 ... Segment transparent electrode group 8 ... Display Part 9 Seal resin 10 Liquid crystal 11 Common electrode terminal group 12 Segment electrode terminal group 14 Semi-transmissive film 15 Color filter 16 Overcoat 17, 21 Wiring pattern 18 with semi-transmissive film Liquid crystal display 19… Driving element (IC)

Continuation of front page    F-term (reference) 2H092 GA05 GA17 GA25 GA28 GA32                       GA34 GA39 GA42 GA51 GA55                       HA05 HA06 HA12 HA18 JA24                       NA25 NA28 NA29 QA06 QA10                 5C094 AA42 AA43 AA44 BA45 CA19                       CA20 DB02 EA05 EA07 EB02

Claims (1)

Claims: 1. A semi-transmissive film made of a metal material having both light reflectivity and light transmissivity, a transparent electrode group arranged in stripes, and an alignment film are formed on a substrate. The other member formed by forming an alignment film and another transparent electrode group arranged in a stripe shape on the substrate and the other member formed by a liquid crystal surrounded by a seal member are arranged so that both transparent electrode groups are orthogonal to each other. A wiring pattern connected to the transparent electrode group on one member and a current flowing through the wiring pattern on the other member, wherein the wiring pattern on the one member is A liquid crystal display device comprising a permeable film made of a metal material.