JPH1031224A - Display substrate and liquid crystal display device using the same - Google Patents

Abstract

(57) [Abstract] [Problem] To prevent display quality deterioration due to variation in resistance value of a lead wire. Easier design of the transparent electrode that composes the lead wire. SOLUTION: A predetermined number of sets of a substrate 30, a plurality of transparent electrodes 34 formed in a lighting area A on one surface of the substrate, and external connection terminals 36 having a width smaller than the width of each transparent electrode are collected. A plurality of external connection terminal portions 37 spaced apart from one side of the substrate and a predetermined number of lead wires 38 inclined to connect one end of the transparent electrode 34 to the corresponding external connection terminal 36 are collected and separated. In a display substrate having a plurality of lead-out portions 39 disposed, the lead-out portion 39 is formed by forming the lead-out line 38 on a transparent electrode layer 38a and a metal layer having a lower resistance than the transparent electrode layer 38a formed thereon. 38b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device such as a liquid crystal display device using a transparent electrode as a display electrode, and more particularly to a lead wire for drawing an electrode in a lighting area to a terminal for external connection. The present invention relates to a display substrate using metal wiring and a liquid crystal display device using the same.

[0002]

2. Description of the Related Art In a simple matrix type display device, a plurality of transparent electrodes are arranged in a stripe shape in a lighting area of a display substrate, and a connection terminal portion for connecting to a driving element is provided at one end of the substrate. Provided, a plurality of the connection terminal portions are arranged apart from each other, and between the lighting region and the connection terminal portion, a lead wire portion formed of the same member as the transparent electrode for leading one end of the transparent electrode to the connection terminal portion is provided. Have been placed. And
Since the connection terminal portions are spaced apart from each other and the positions of the transparent electrode and the corresponding connection terminal are shifted, the lead wire is bent from near one end of the transparent electrode and drawn obliquely with respect to the transparent electrode. Here, since the lead wire is made of a member having a relatively high resistance value such as ITO, there is a difference in the length between the case where the lead wire is located at the center of the lead wire portion and the case where it is located at the end. And the difference in length greatly affects the resistance value. If a difference occurs in the resistance value of the lead line, the difference greatly affects the display quality. Conventionally, the width of the lead line is adjusted to make the resistance value of the lead line uniform.

However, as the display screen becomes larger,
As the number of leader lines constituting the leader part increases, it is becoming difficult to adjust the width of the leader lines. In particular, since the length of the lead wire located at the end of the lead wire portion is relatively long, adjustment is made to increase the width and reduce the resistance value, but the lead wire located at the end is provided with the lead wire. As the angle becomes acute, it is becoming difficult to make adjustments to increase the width of the leader line.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to prevent the deterioration of display quality due to the variation of the resistance value of the lead wire portion in view of the above points. One of the problems is to facilitate the design of the transparent electrode constituting the lead wire portion.
One. One of the problems is to solve a new problem caused by the improvement of the lead line portion and to improve display quality.

[0005]

A display substrate according to the present invention comprises:
A predetermined number of a substrate, a plurality of transparent electrodes formed in a lighting area on one surface of the substrate, and external connection terminals having a width smaller than the width of each of the transparent electrodes are separately arranged on one side of the substrate. A plurality of external connection terminal parts, and a plurality of lead lines inclined at predetermined intervals to connect one end of the transparent electrode to the corresponding external connection terminal, and a plurality of lead line parts spaced apart from each other. In the substrate, the lead line portion is characterized in that the lead line is formed by a transparent electrode layer and a metal layer formed thereon and having a lower resistance than the transparent electrode layer.

Further, the metal layer has a narrow region and a wide region, and the wide region is arranged along a sealing agent arrangement line. Further, a plurality of dummy electrodes having the same structure as the lead lines are arranged in a region between the lead line portions and separated from each other along the sealing agent arrangement line.

Further, the display substrate of the present invention comprises: a substrate; a plurality of transparent electrodes formed in a substantially area on one surface of the substrate; an external connection terminal provided on one side of the substrate; A transparent electrode layer and a lead line portion formed by assembling a predetermined number of lead lines formed of a metal layer provided thereon so as to connect the transparent electrode located inside and the external connection terminal provided in the external connection terminal portion. A metal layer having the same thickness as the metal layer of the lead wire is formed on the transparent electrode located at the outer peripheral portion of the lighting region, along a sealing agent arrangement line set so as to surround the lighting region. It is characterized by.

Further, the liquid crystal display device of the present invention is characterized in that the display substrate is used as at least one display substrate.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. Color according to one embodiment of the present invention
The liquid crystal display device 1 uses a sealant (not shown) to seal the outer peripheral portions of the first display substrate 2 and the second display substrate 3 as shown in FIG. Are sealed along the planned seal arrangement line L shown in FIG.
A display device of a simple matrix type in which the liquid crystal 4 is sealed so as to be twisted by 270 degrees, and a polarizing plate and a phase difference plate (neither is shown) are arranged as necessary so as to sandwich the display device. Be composed.

The first display substrate 2 is a substrate 2 made of glass or the like.
A plurality of segment line transparent electrodes 21 are formed in a stripe shape on one surface of the substrate.

The second display substrate 3 is a substrate 30 made of glass or the like.
Forming a black matrix layer 31 on one surface of
On top of this, three color elements (red, green, blue) are sequentially arranged in stripes in the same direction with the same width as the segment line transparent electrode 21 to form a color filter layer 32, and the color filter layer 32 is formed so as to cover it. A bar coat film 33 is formed, and a plurality of common line transparent electrodes 34 in a direction perpendicular to the stripe direction of the color filter layer 32 are formed thereon. The plurality of transparent electrodes 21 and 34 are made of ITO (Sn-doped In ₂
O ₃ ) It is formed of a transparent conductive metal oxide layer such as a thin film. The thickness of the transparent electrode 21 is set to about 300 nm, and the thickness of the transparent electrode 34 is set to about 100 nm. Each of the common line transparent electrodes 34 includes gold such as a Ni-Au (nickel-gold) alloy by electroless plating, and has much higher conductivity than the transparent electrodes 34 (having a resistance value of much higher). The metal wiring 35 is formed.

An alignment film can be provided on the surfaces of the first and second display substrates facing each other as needed.

The second display substrate 3 has a lighting area A at the center, an outer peripheral area B surrounding the lighting area A, and an outer peripheral area as schematically shown in a plan view of FIG. A connection terminal area C for connection to an external wiring located on one side of the substrate 3 adjacent to B is formed.

In the lighting area A, a plurality of common lines COM each having a metal wiring 35 formed on the upper surface of a transparent electrode 34 are arranged in a stripe pattern in the left-right direction, as shown in a partially enlarged view in FIG. . The metal wiring 35 is set to a width (20 to 50 μm) which is considerably narrower than the transparent electrode 34 (around 300 μm in width) in order to suppress a decrease in light transmittance. Are located.
By arranging the metal wiring 35 at the center of the transparent electrode 34, the metal wiring 35 is prevented from peeling off.

In the connection terminal area C, as shown in FIGS. 2 and 3, an external connection terminal 36 is formed by assembling a predetermined number of external connection terminals 36 having a width smaller than the common line COM at a smaller pitch than the common line COM. A plurality of the portions 37 are arranged along one end of the substrate 30.

The outer peripheral area B includes a left area B1 located between the lighting area A and the connection terminal area C and functioning as a common line drawing area, and a right area B2 located on the right side of the lighting area A.
It is formed by an upper region B3 located above and below the lighting region A and a lower region B4.

As shown in FIGS. 2 and 3, one end of the common line COM of the lighting area A is connected to the connection terminal section 3 in the left area B1.
A plurality of lead wire portions 39 formed by assembling a predetermined number of lead wires 38 for leading to 7 are formed apart from each other,
A plurality of dummy electrode regions 41 formed by assembling a predetermined number of dummy electrodes 40 are formed on both sides of the lead wire portion 39.

As shown in detail in FIG. 3, most of the lead wire 38 is connected to one end of a common line COM by a corresponding connection terminal 36.
Are bent at a predetermined angle with respect to the common line COM. Each lead line 38 is constituted by a transparent electrode layer 38a formed simultaneously with the formation of the transparent electrode 34 as shown in FIG. 4 and a metal layer 38b formed thereon simultaneously with the formation of the metal wiring 35.

By providing the metal layer 38b on the transparent electrode layer 38a, the resistance of the lead 38 can be reduced to about 1/100 as compared with the case where only the transparent electrode layer 38a is used. The variation of the resistance value according to the lead length to the portion 37 can be set small enough to be almost negligible, and the degree of freedom in designing the lead angle and width of the lead wire 38 can be extremely increased. Therefore, the transparent electrode layer 3
The lead wire 38 provided with the metal layer 38b on 8a is used not only when the metal wiring 35 is provided on the transparent electrode 34 as the wiring of the lighting area A as in this example but also when only the transparent electrode 34 is provided. This is also useful for increasing the degree of freedom in designing the extraction angle and width of the extraction line 38.

The metal layer 38b has a narrow region 38b1 and a wide region 38b2. Narrow area 38b
1 is provided on the lighting area A side and has a width of the metal wiring 35.
Is set to be as narrow as the width of. Like the metal wiring 35, the narrow region 38b1 prevents the light passing through the transparent electrode layer 38a (especially, the effective display region set at the outer peripheral portion of the lighting region A) from blocking the material (particularly, the material forming the metal layer 38b). This contributes to a reduction in the amount of expensive gold) used.

The wide region 38b2 is provided on the connection terminal region C side, and has a width of the metal wiring 35 or the narrow region 38b.
The width of the transparent electrode layer 38a is set to be equal to or slightly smaller than the width of the transparent electrode layer 38a so as to be sufficiently wide, which is about several times the width of the metal layer 38b in FIG. The wide region 38b2 contributes to the flattening of the base portion of the sealant. In other words, when the narrow region 38b1 having the same width as the common line COM is located as a base layer along the portion L where the sealant is to be arranged, the narrow metal layer 38 is formed.
b tends to make the thickness of the sealant uneven. Therefore,
In order to prevent this, a wide area 38b2 of the metal layer 38b is formed on the lead line 38 along the sealing agent arrangement line L. The portion where the width of the metal layer 38b is widened may be a region slightly larger than the width of the sealing agent planned line L.
8b can be minimized.

In the dummy electrode region 41, a plurality of dummy electrodes 40 are formed along the lead line portion 38 along the sealing agent arrangement line L.
It is configured so as to be spaced apart so as to fill the space between and around it. The dummy electrode 40 includes a transparent electrode layer 40a formed simultaneously with the formation of the transparent electrode 34 and a metal layer 40b formed simultaneously with the metal wiring 35 thereon, similarly to the lead line 38, and is the same as the lead line 38. The thickness is set. Like the metal layer 38b in the wide area 38b2 of the lead wire 38, the width of the metal layer 40b on the dummy electrode 40 is sufficiently large, about several times the width of the metal layer 38b in the metal wiring 35 or the narrow area 38b1. As described above, the width is set to be substantially the same as or slightly smaller than the width of the transparent electrode layer 40a.

As shown in FIG. 5, in the right area B2, a pseudo lead line section 42 having a similar shape to the lead line section 39 formed in the left area B1 is formed. However, the metal layer 42b of the pseudo lead line portion 42 is formed of the metal wiring 35 of the common line COM.
And the wide area 3 formed on the leader line 38
The region corresponding to the portion 8b2 is formed in the dummy electrode region 43 that is separated from the pseudo lead line portion 42. This dummy electrode region 43 is constituted by a plurality of dummy electrodes 44 spaced apart along the sealing agent arrangement line L. Like the dummy electrode 40, the dummy electrode 44 includes a transparent electrode layer 44a formed simultaneously with the formation of the transparent electrode 34, and a metal layer 44b formed thereon simultaneously with the metal wiring 35. 38 is set to the same thickness. Metal layer 44b on dummy electrode 44
The width of the metal wiring 3 is the same as that of the dummy electrode 40.
The width of the transparent electrode layer 44a is set to be substantially the same as or slightly smaller than the width of the transparent electrode layer 44a so as to be sufficiently wide, which is about several times the width of the metal layer 38b in the 5 to narrow region 38b1.

As shown in FIG. 6, the upper region B3 is provided with a dummy electrode region 46 in which a plurality of dummy electrodes 45 are formed apart from each other along the sealing agent arrangement line L. The dummy electrode 45 has the same configuration as the dummy electrodes 40 and 44 except for a point perpendicular to the common line COM. The lower region B4 is also provided with a dummy electrode region 47 along the sealing agent arrangement line L as shown in FIG. 2, and the dummy electrode region 47 is configured in the same manner as the dummy electrode region 46 shown in FIG. Is done.

In this manner, a plurality of transparent electrode layers are formed in substantially the entire outer peripheral area B surrounding the lighting area A. As a result, the second display substrate 3 has one of the transparent electrode layers formed thereon. A plurality of transparent electrodes are formed over substantially the entire surface.

In the left region B1 where the lead portion 39 is provided, the lead 38 is thicker than the other regions B2 to B4 because the lead 38 is disposed with the metal layer 38b. Although imbalance occurs and causes the thickness of the liquid crystal layer 4 to be non-uniform, the other regions B2 to B4 have dummy electrodes having the same thickness as the lead lines 38 along the sealing agent arrangement lines L. Electrode areas 43, 46, 4
Since the underlayer 7 is formed, the underlying layer portion of the sealing agent disposition line L can be entirely flattened, and the influence of the increase in the thickness of the lead wire 38 can be eliminated.

The dummy electrode region is formed not only in the regions B2 to B4 where the lead-out lines 38 are not arranged but also in the left region B1 where the lead-out lines 38 are provided so as to fill the space between the lead-out portions 39 and the peripheral portion. Accordingly, the underlying layer portion of the sealing agent disposition line L can be made flatter as a whole, and the thickness of the liquid crystal layer 4 can be made uniform by keeping the thickness of the sealing agent uniform.

Here, the metal layer 38 formed on the lead wire 38
b has a narrow region 38b1 and a wide region 38b2,
Since the wide region 38b2 is provided along the sealing agent disposition line L, the flat region of the base portion can be more widely secured. Since the narrow area 38b1 exists between the wide area 38b2 and the lighting area A, the wide area 3
8b2 can also prevent light from being blocked.

The metal layer 38b formed on the lead wire 38
Is set to be wide only in the portion corresponding to the sealing agent arrangement line L, and the width on the side connected to the lighting region A is set to be narrow, so that the use of the material forming the metal layer can be minimized. it can.

Similarly, dummy electrode regions 41, 43, 4
6 and 47, the width of the metal layer is set to be wide only in the portion corresponding to the sealing agent arrangement line L.
Use of the material forming the metal layer can be minimized. In particular, in this example in which the metal material contains gold, the amount of gold used can be reduced, which can contribute to cost reduction.

Since the dummy electrode region 41 and the other dummy electrode regions located near the lead line portion 39 are provided separately from the lighting region A, the light near the lighting region A is blocked by the metal layer. Can be prevented.

Each of the dummy electrodes in the above embodiment is
Although it has a rectangular shape, a dummy electrode 48 (formed of a transparent electrode layer 48a and a metal layer 48b) having a square shape with a side of about 300 μm as shown in FIG. 7 is used instead. Can also.

In the above-described embodiment, the case where the present invention is applied to the display substrate 3 on the side provided with the common line COM is illustrated. However, the present invention relates to the display substrate 3 on the side provided with the segment lines. 2 and can be applied to both display substrates 2 and 3 at the same time.

[0034]

As described above, according to the present invention, it is possible to reduce the resistance value of the lead wire portion, thereby increasing the degree of freedom in designing the lead wire, and to reduce the length of the lead wire portion. The display quality can be improved by eliminating display unevenness.
The metal layer provided for lowering the resistance of the lead line portion causes irregularities in the base portion of the sealant, but the metal layer having the same thickness as the metal layer is provided on the transparent electrode layer provided along the scheduled sealant arrangement line. Since the layer is provided, the base portion of the sealant can be kept flat, and the thickness of the liquid crystal layer can be kept uniform.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a liquid crystal display device according to an embodiment of the present invention.

FIG. 2 is a schematic plan view of a display substrate 3 of the display device.

FIG. 3 is an enlarged view of a main part of FIG. 2;

4 is an essential part enlarged view showing only a transparent electrode part in the enlarged view shown in FIG. 3;

FIG. 5A is an enlarged view of a main part (right region B2) of FIG. 2;
(B) is an enlarged view of a main part showing only a transparent electrode portion.

FIG. 6A is an enlarged view of a main part (upper region B3) of FIG. 2;
(B) is an enlarged view of a main part showing only a transparent electrode portion.

7A and 7B show another configuration example of the dummy electrode, FIG. 7A is an enlarged view thereof, and FIG. 7B is an enlarged view showing only a transparent electrode portion.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Liquid crystal display device 2 1st display substrate 3 2nd display substrate 4 Liquid crystal layer 21 Transparent electrode 34 Transparent electrode 35 Metal wiring 37 Connection terminal part 38 Lead wire 39 Lead wire part 40 Dummy electrode 41 Dummy electrode area 43 Dummy electrode area 44 Dummy electrode 45 Dummy electrode 46 Dummy electrode area 47 Dummy electrode area 48 Dummy electrode

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Hiroshi Inamura 3-201 Minamiyoshikata, Tottori City, Tottori Prefecture Tottori Sanyo Electric Co., Ltd.

Claims (5)

[Claims] A substrate, a plurality of transparent electrodes formed in a lighting area on one surface of the substrate, and a predetermined number of external connection terminals each having a width smaller than a width of each of the transparent electrodes; 1
A plurality of external connection terminal portions disposed on the side and a plurality of lead line portions which are separated by a predetermined number of sets of lead lines inclined to connect one end of the transparent electrode to the corresponding external connection terminal; The display substrate according to claim 1, wherein the lead line portion is formed by a transparent electrode layer and a metal layer formed on the transparent electrode layer and having a lower resistance than the transparent electrode layer. 2. The display according to claim 1, wherein the metal layer includes a narrow region and a wide region, and the wide region is arranged along a sealing agent disposition line. substrate. 3. In a region between the lead line portion and the lead line portion,
3. The display substrate according to claim 2, wherein a plurality of dummy electrodes having the same structure as the lead lines are arranged apart from each other along the sealing agent arrangement line. 4. A substrate, a plurality of transparent electrodes formed in a substantially area of one surface of the substrate, an external connection terminal provided on one side of the substrate, a transparent electrode located inside a lighting area, and A lead wire portion formed by assembling a predetermined number of lead wires made of a transparent electrode layer and a metal layer provided thereon so as to connect an external connection terminal provided in the external connection terminal portion is provided at an outer peripheral portion of the lighting region. A display substrate, wherein a metal layer having the same thickness as the metal layer of the lead wire is formed on the transparent electrode along a sealing agent arrangement line set so as to surround the lighting region. 5. The method according to claim 1, wherein at least one display substrate is provided.
A liquid crystal display device using the display substrate according to claim 4.