JP3288260B2 - Liquid crystal display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display panel, and more particularly to a super twisted nematic liquid crystal display panel.

[0002]

2. Description of the Related Art Conventionally, a liquid crystal display device has a large capacity,
Development for high-speed response and mass production has been promoted. In recent years, development for realizing miniaturization while maintaining display capacity as a display of a portable terminal has been made.

As a liquid crystal display element generally used as a display of such a portable terminal, the arrangement direction of liquid crystal molecules having dielectric anisotropy is twisted by 180 to 300 degrees between a pair of electrode substrates, and the birefringence thereof is obtained. A super-twisted nematic type (hereinafter, referred to as "STN type") utilizing the effect is generally used.

The STN type liquid crystal display element forms a matrix of pixels by opposing a pair of substrates on which strip-shaped pixel electrodes are formed so that the respective pixel electrodes are orthogonal to each other, and forms a matrix between the two substrates. Are liquid crystal materials having dielectric anisotropy.

FIG. 2 is a diagram showing a configuration of a lead electrode portion of a conventional STN type liquid crystal display device. As shown in FIG. 2, the data input terminal 2 and the strip-shaped pixel electrode 3 have (1),
(N),... (N) are assigned line numbers, and the data input terminals 2 and the pixel electrodes 3 of the corresponding line numbers are connected to the conductor electrodes 1 similarly assigned line numbers. Connected by

The data input terminal 2 and the pixel electrode 3 are arranged so as to be symmetrical about the dashed line 5, and a point on the dashed line 5 indicated by an arrow E and a minimum line number (1) Dashed line 4a connecting the center point of the data input terminal 2 at the position in contact with the conductor electrode, the point on the dashed line 5 indicated by the arrow E and the position of the largest line number (N) in contact with the conductor electrode of the data input terminal 2. A region A sandwiched by a dashed line 4b connecting the center point of is formed.

[0007]

In the STN type liquid crystal display device, it is necessary to make the supply voltage difference between the pixel electrodes 3 constant in order to eliminate display unevenness.
Are arranged so that the resistance value of the lead wire becomes constant. That is, when the distance between the data input terminal 2 and the pixel electrode 3 is long, the width of the conductive electrode 1 is increased, and when the distance between the data input terminal 2 and the pixel electrode 3 is long, the width of the conductive electrode 1 is reduced. By doing so, the resistance value of each conductive wire electrode 1 is made constant.

For this reason, the conductor electrode 1 connected to each data input terminal 2 is parallel to the dashed line 5 and corresponds to each line number until the contact with the broken line 4a or 4b. , D (n),... D (N), after contacting the broken line 4a or 4b, that is, after exceeding the range of the region A, the center line of the conductive electrode and the pixel Angle φ from center line with electrode
, And each line width is D (1),... D
(N),... D (N).

The resistance value R (n) of the conductive wire electrode 1 configured as described above is expressed by equation (6).

[0010]

(Equation 1)

Here, n is the n-th line number, N is the maximum line number, B is the width of the conductive electrode region, and d (n) is the region A
, D (n) is the line width of the conductor electrode other than the region A, r is the sheet resistance of the conductor electrode,
P _DOT is the line pitch of the pixel, and P _TAB is the line pitch of the data input terminal. Note that d (n) and D (n) are n
Is treated as a constant value for simplicity. Less than,
The same symbols are used in the equations (7) and (1) to (5).

The conductor electrodes arranged as described above are indicated by arrows C formed on a part of the conductor electrode region on the data input terminal 2 side connecting the data input terminal 2 indicated by the arrow B and the pixel electrode 3. Is fixed in the sealing area to be sealed.

The lead electrode density S (n) in the sealing region indicated by the arrow C is expressed by the following equation (7).

[0014]

(Equation 2)

Here, C represents a sealing area, and φ represents an angle formed between the center line of the pixel electrode 3 and the center line of the conductive wire electrode. As described above, in the sealing seal region C, the ratios of the line widths d (n) and D (n) at the respective line numbers are different. The value will no longer be constant. That is, in the sealing region, the density difference ΔS _p [%] of the conductive wire electrode defined by the following equation (8) increases.

[0016] Density of _{ΔS p = (S MAX -S MIN} ) × 100 (8) the value of the density difference [Delta] S _p of the conductor electrode as defined above (8) is increased, conductor electrode in the sealing seal region C There is a problem that a gap difference is generated due to the difference and a display failure occurs. This is due to the phenomenon that the sealing resin swells in the cell gap direction due to the density difference.

The present invention solves the above-mentioned problems, and provides a liquid crystal display device having a good display quality by reducing the difference in the density of the conductive wire electrodes in the sealing region and thereby reducing the gap difference.

[0018]

The liquid crystal display element according to the present invention is characterized in that the density difference is reduced by making the density of the conducting wire electrodes formed in the sealing region uniform.

According to the present invention, it is possible to provide a liquid crystal display device having a good display quality by reducing the gap difference between the liquid crystal display devices.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a liquid crystal display device according to the present invention, a pair of substrates are opposed to each other such that strip-shaped pixel electrodes are orthogonal to each other, and a liquid crystal having dielectric anisotropy is provided between the two substrates. In the liquid crystal display element sandwiched between
The lead wire electrode formed in the sealing area where the plates are attached
To a data input terminal with a narrower pitch than the pixel electrode
Connect and pull out and arrange the plurality of pixel electrodes
A plurality of the data input terminals are arranged at the center line of the direction.
Align the center position and connect the ends of the pixel electrodes
The array is arranged on the line by a virtual line shift width from the center line.
From a first point outside the direction,
On the same side as point 1 and farthest from the center line
A first virtual line connecting the end of the data input terminal of FIG.
On the line connecting the ends of the pixel electrodes to the center line.
And the imaginary line shift width on the side opposite to the first point.
From a second point at the same distance as
On the same side as point 2 and farthest from the center line
A second virtual line connecting the end of the data input terminal of FIG.
With respect to the center line of the pixel electrodes.
The conductor extending from the pixel electrode located outside the first point.
The line electrode has a first inclination inward toward the center line.
Corners parallel to each other at a position where they touch the first imaginary line.
At the first specified width, and from the position,
Further extend to the end of the data input terminal with the second specified width.
Connected to the center line of the pixel electrodes.
Extending from the pixel electrode located outside the second point;
The conductor electrodes are mutually inwardly approaching the center line.
At a position where it is parallel to the second virtual line at a first tilt angle
Up to the first specified width up to that point and apply from that position
The second specified width is further extended to the end of the data input terminal.
And connected to the center line of the pixel electrodes.
On the other hand, the pixel electrode located inside the first point
Which of the data input terminals should be connected to this pixel electrode
The lead wire electrode for connecting to the data input terminal of
The first point relative to the center line of the elementary electrodes
The outer side away from the center line from the pixel electrode located on the inner side
The first specified width parallel to each other at a first inclination angle toward
And the end of the electrode extending from the corresponding data input terminal
At a second tilt angle outwardly away from the center line
In parallel with the electrode extended at the second specified width.
Constituting the pixel electrode with respect to the center line of the pixel electrode.
A pixel electrode located inside the second point and the data input;
Input the corresponding data to be connected to this pixel electrode
The conductive wire electrode for connecting to the power terminal is connected to the pixel electrode.
Located inside the second point with respect to the center line
From the pixel electrode to the outside away from the center line
The electrodes extending at the first specified width in parallel with each other at the first inclination angle
The end of the pole and the center line from the relevant data input terminal
Parallel to each other at a second angle of inclination toward the outside away from
And connecting the electrode extended with the second specified width,
The second specified width is narrower than the first specified width .

According to this configuration, the difference in the density of the conductive wire electrodes in the sealing region can be reduced, the gap difference between the liquid crystal display elements is reduced, and display defects are reduced.

[0022] hereinafter be described with reference to FIG. 1 for an embodiment of the present invention.

(Embodiment) FIG. 1 is substantially the same as FIG. 2 showing a configuration diagram of a conductor electrode portion of a conventional STN type liquid crystal display element. Are shifted from the dashed line 5 by the width y as indicated by arrows.

In the configuration of the conductor electrode portion in which the broken lines 4a and 4b are shifted by the width y as described above, the region A is surrounded by the broken lines 4a and 4b around the dashed line 5 and the other region. .

The conductive line electrodes 1 having the line numbers corresponding to the pixel electrodes 3 existing between the alternate long and short dash line 5 and the broken lines 4a or 4b are arranged from the pixel electrode 3 side to the center line of each pixel electrode 3 and the conductive line electrode 1 Are arranged so as to be parallel to the direction away from the center line 5, and from the data input terminal 2 side, the center line of each data input terminal 2 and the conductor electrode The angle γ with the center line of 1
, And are arranged so as to be parallel to each other in a direction away from the center line 5, and come into contact with each other at positions indicated by broken lines 6a and 6b.

Pixel electrode 3 having other line numbers
In the area A, the conductor electrode 1 derived from the data input terminal 2 side is located at the center of the data input terminal 2 and the center of the conductor electrode 1 from the data input terminal 2 side. The lines are arranged so as to have an angle γ and to be parallel to the direction away from the alternate long and short dash line 5. After coming into contact with the broken line 4a or 4b, that is, after leaving the area A, the center line of each pixel electrode 3 and the center line of the conductive line electrode 1 form an angle φ, and each of the directions is away from the dashed line 5. Are arranged so as to be parallel to.

That is, the arrangement of the conductive wire electrode 1 in a place other than the region A is the same as that of the conventional example shown in FIG.
In the region A, the arrangement of the conductive electrodes 1 of the number of the pixel electrodes 3 between the alternate long and short dash line 5 corresponding to the virtual line shift amount V and the broken line 4a or 4b is different.

The resistance value R (n) of the conductive wire electrode 1 when the virtual line shift is performed as described above is expressed by equation (1).

[0029]

(Equation 3)

Here, V represents a virtual line shift amount.
Further, among the resistance values of the respective lead wire electrodes obtained from the above equation (1), those having the maximum resistance values are represented by R _MAX ,
Assuming that the minimum value is R _MIN , ΔR representing the ratio of the resistance difference ΔR of the conductor electrode and the resistance difference ΔR of the conductor electrode
_p is represented by the following equations (2) and (3), respectively.

ΔR = R _MAX −R _MIN (2) ΔR _p = (ΔR / R _MAX ) × 100 (3) With the above configuration, the supply voltage for each pixel electrode 3 in order to eliminate display unevenness When making the difference constant, the length of each conductive wire electrode becomes substantially uniform, so that the width of the conductive wire electrode 1 can be made substantially constant, and the value of ΔR _p representing the ratio of the resistance value difference ΔR of the conductive wire electrode Can be reduced.

Further, the density S (n) of the conductive wire electrode in the sealing area where the virtual line shift has been performed as described above is (4)
It is expressed by an equation.

[0033]

(Equation 4)

Note that γ represents an angle formed between the center line of each data input terminal 2 and the center line of the conductive wire electrode 1. In the present invention, the difference between the conductor electrode densities ΔS _p in the sealing region is expressed by the following equation using the maximum value S _MAX and the minimum value S _MIN of the conductor electrode density obtained by the equation (2) in the same manner as the equation (8). Defined by

ΔS _p = (S _MAX −S _MIN ) × 100 (5) In the liquid crystal display element configured as described above, the resistance of each conductive wire electrode 1 is adjusted so that the supply voltage difference of each pixel electrode 3 becomes constant. Even if they are arranged so that the values are equal, the length of the conductive wire electrode 1 is substantially uniform, so that the width of the conductive wire electrode 1 is also substantially uniform. Also, by making the center line of each data input terminal 2 and the center line of the conductive wire electrode 1 have a slope of γ, 1 / cos γ as the first item of the above equation (4) becomes 1 or more, it is possible to further increase the value of S _{M iN.} Therefore, it is possible to reduce the value of [Delta] S _p in equation (5). That is, since the wire electrode density difference [Delta] S _p of the conductor electrode 1 in the sealing seal region C becomes smaller, the gap of the liquid crystal display device is reduced, it is possible to obtain satisfactory display quality.

[0036]

Next, specific examples of the present invention will be described. (Embodiment 1) In FIG. 1, the conductor electrode area indicated by the arrow B is 2.2145 mm, the maximum line number of the data input terminal 2 is 240, and the line pitch P of the data input terminal 2 is
_TAB is 0.065 mm, and the line pitch P _{DOT of} pixels is 0.
088 mm, 1.5 times the sealing area indicated by arrow C.
00 mm, the wire electrode width d (n) of the line number n is 0.0
40 mm, the wire electrode width D (n) of the line number n is 0.0
It was 40 mm.

The virtual line shift was set to 45, and the virtual line shift width indicated by y was set to 1.035 mm.
The sheet resistance value r of the conductive wire electrode 1 was 4.5Ω, the angle φ was 0.893, and the angle γ was 0.479.

The difference ΔR between the resistance values of the conductor electrodes obtained from the above values and the equations (1) and (2) was 121Ω. Also, the resistance difference ΔR of the conductive wire electrode obtained by the equation (3)
ΔR _p representing the ratio of was 30.5%.

Further, the difference ΔS _{p in the} lead wire electrode density obtained by the equation (5) was 4.54%. Thus (Example 1), was able to reduce the value of the wire electrode density difference [Delta] S _p, which has been a 15% or more in the conventional configuration. As a result, the difference in the lead electrode density ΔS in the sealing region C
_The gap difference caused by _p became small, and the display failure could be improved. Here, the ratio ΔR _p of the resistance value difference between the conductor electrodes is the maximum difference between the electric resistance values between the lines. If this value is too large, a voltage difference due to the electric resistance value causes display failure. If this ΔR _p is 50% or less, good quality can be realized, and the smaller the value, the better.

(Example 2) In the above (Example 1),
The value of the virtual line shift was set to 60, and the virtual line shift width indicated by y was set to 1.380 mm. The angle φ was 0.893 and the angle γ was 0.557.

As a result, ΔR _p representing the ratio of the resistance difference ΔR of the conductive wire electrode obtained by the equation (3) is 25.86%
It became. In addition, the difference in density of the conductive wire electrode ΔS _p obtained by the equation (5) was 0.06%.

In this (Embodiment 2), the above (Embodiment 1)
Since the value of the line shift was further increased, display defects could be further improved. (Comparative Example 1) In the above (Example 1), the line number n
Was set to 0.035 mm, and the electrode width D (n) of the line number n was set to 0.033 mm. No virtual line shift was performed.

In this (Comparative Example 1), ΔR _p representing the ratio of the resistance value difference ΔR of the conductor electrode was 0.17%, and the conductor electrode density difference ΔS _p was 5.92%. As a result, ΔR _p was 0.17%, and a voltage difference occurring as an electric resistance value could be suppressed. However, a gap difference in a sealing region in this liquid crystal display element was increased, and display defects could be improved. could not.

[0044] As described above, in the case of not performing the line shift wire electrode density difference [Delta] S _p becomes 5% or more, display quality gap difference is large in the sealing seal region is lowered. Although the value of the line shift in the present invention is not limited, ΔR _p representing the ratio of the resistance value difference ΔR of the conductor electrode and the conductor electrode density difference ΔS _p
In consideration of the above, it is preferable to adjust the line electrode density difference ΔS _p to 5% or less to perform the line shift.

[0045]

As described above, according to the liquid crystal display device of the present invention, the density difference between the conductive electrodes formed in the sealing region is reduced by reducing the density difference between the conductive electrodes. It is possible to provide a liquid crystal display element having a small gap and good display quality.

In other words, even when the line electrodes are arranged so that the supply voltage difference between the pixels becomes constant and the resistance values of the respective lead electrodes become equal, the length of the lead electrodes becomes substantially uniform. Therefore, the width of the conductive wire electrode is also substantially uniform. Accordingly, the wire densities inevitably become substantially uniform, and particularly, in the sealing and sealing region, the wire density difference is reduced to 5% or less, and the gap difference between the liquid crystal display elements can be reduced, so that good display quality can be obtained. Can be.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a conductive wire electrode unit according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a conductive wire electrode portion of a conventional liquid crystal display element.

[Explanation of symbols]

 1 lead wire electrode 2 data input terminal 3 pixel

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G02F 1/1345 G02F 1/1339

Claims (1)

(57) [Claims] 1. A are opposed to the pair of substrates as strip-shaped pixel electrodes formed in each of mutually orthogonal, between both substrates in a liquid crystal display device in which a liquid crystal having a dielectric anisotropy is sandwiched, wherein Formed in the sealing area (C) where both substrates are attached
The pixel electrode (3) via the conducting wire electrode (1).
When connected to the narrow pitch data input terminal (2) and pulled out
Both are located at the center line (5) in the arrangement direction of the plurality of pixel electrodes (3).
Center position in the arrangement direction of the plurality of data input terminals (2)
And the center line on a line connecting the ends of the pixel electrode (3).
From (5), the arrangement direction by the virtual line shift width (y)
From a first point outside of the center line (5)
On the same side as the first point and furthest from said center line (5)
The second end connecting the end of the data input terminal (2)
Assuming one virtual line (4a), the center line is drawn on a line connecting the ends of the pixel electrode (3).
The virtual line is located on the opposite side of (5) from the first point.
From a second point at the same distance as the shift width (y).
On the same side of the line (5) as the second point,
The data input terminal located farthest from the center line (5);
Assuming a second virtual line (4b) connecting the end of (2), with respect to the center line (5) of the pixel electrode (3)
From the pixel electrode (3) located outside the first point
The extending conductor electrode (1) approaches the center line (5).
Inward at a first inclination angle (φ)
The first rule up to the position where it contacts the first virtual line (4a)
Extend the width (D) and enter the relevant data from that position.
Further extended to the end of the force terminal (2) by the second specified width (d).
To the center line (5) of the pixel electrodes (3).
From the pixel electrode (3) located outside the second point
The extending conductor electrode (1) approaches the center line (5).
At the first inclination angle (φ) parallel to each other
The first position is brought to a position where it contacts the second virtual line (4b).
Extended with defined width (D), to the person from the position the data
To the end of the data input terminal (2).
(D) is extended and connected to the center line (5) of the pixel electrode (3).
A pixel electrode (3) located inside the first point and
The pixel electrode (3) is connected to the data input terminal (2).
The wire connection to the corresponding data input terminal to be connected.
The pole (1) is connected to the center line of the pixel electrode (3).
Pixels located inside the first point with respect to (5)
From the electrode (3) outward away from the center line (5)
The first specified width parallel to each other at a first inclination angle (φ).
An end of the electrode extending at (D) and the corresponding data input end;
From the child (2) outward away from the center line (5)
The second specified width parallel to each other at a second tilt angle (γ).
(D) is connected to the electrode extended, and the center line (5) of the pixel electrode (3) is
The pixel electrode (3) located inside the second point and
The pixel electrode (3) is connected to the data input terminal (2).
The wire connection to the corresponding data input terminal to be connected.
The pole (1) is connected to the center line of the pixel electrode (3).
Pixel located inside the second point with respect to (5)
From the electrode (3) outward away from the center line (5)
The first specified width parallel to each other at a first inclination angle (φ).
An end of the electrode extending at (D) and the corresponding data input end;
From the child (2) outward away from the center line (5)
The second specified width parallel to each other at a second tilt angle (γ).
(D) is connected to the extended electrode, and the second specified width is larger than the first specified width (D).
(D) A liquid crystal display element having a reduced size .