JP2000293143A - Liquid crystal driving driver and liquid crystal display device using the same - Google Patents

Abstract

(57) [Problem] To provide an inexpensive and compact liquid crystal driver by making the output load of the liquid crystal driver substantially uniform even when a pixel having a large pixel pitch is connected to a multi-output fine-pitch liquid crystal driver. Liquid crystal display device is provided. A liquid crystal driving driver in which the pitch of output wiring is smaller than the pixel pitch of a liquid crystal panel connected to the output wiring, wherein the gate wiring and the signal wiring have a matrix structure. Alternatively, an output circuit in which a driver output is connected to an electrode portion at the other end of each of the lead-out wiring patterns, one end of which is connected to the signal wiring, is provided. The difference is made so as to correct the inclination tendency of the wiring resistance in the arrangement direction of the lead wiring patterns.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driver for driving a liquid crystal in which the pitch of output wiring is narrower than the pixel pitch of a liquid crystal panel connected to the output wiring, and a liquid crystal display device having the driver.

[0002]

2. Description of the Related Art FIGS. 1 to 4 show a conventional liquid crystal display device. FIG. 1A is a plan view of the liquid crystal display device, and FIG. 1B is a side view of the liquid crystal display device. FIG. 2A is an equivalent circuit diagram of the liquid crystal display device, and FIG. 2B is an enlarged view of a main part of FIG. 1A.

A liquid crystal 5 is filled between a pair of glass substrates 1 on which the transparent electrodes 4 are formed to form a liquid crystal panel. In this liquid crystal panel, a gate wiring and a signal wiring have a matrix structure, and a liquid crystal driving driver 2 is connected to an electrode portion at the other end of each lead-out wiring pattern 13 to which one end of the gate wiring or the signal wiring is connected. Have been. Reference numeral 3 denotes a tape carrier on which the driver 2 is mounted.

In order to simplify the description, a driver 2 having binary output values (VH and VL) and supplying two powers from both sides of the output will be described. The liquid crystal display device makes the resistance value Rc of the wiring resistance 9 of the lead-out wiring pattern 13 of the transparent electrode 4 of the liquid crystal panel uniform as much as possible so that the resistance value does not have a slope, and the resistance value of the VH power supply wiring resistance 6 of the driver 2. Rline (VH) and driver 2 V
By lowering the resistance value Rline (VL) of the L power supply wiring resistor 7,
Furthermore, the driving capability of the driver 2 is made uniform,
Is configured to make the resistance value Ron of the output ON resistor 8 uniform.

Here, Rst is the resistance value of the resistor 10 in the linear portion of the transparent electrode 4, and C is the capacitance value of the capacitance 11 between the opposing electrodes of the liquid crystal layer. In the above description, the tape carrier 3
Although the example in which the driver 2 is mounted on the liquid crystal panel and connected to the liquid crystal panel is described above, there is a liquid crystal display device in which the driver 2 is directly mounted on the liquid crystal panel. In this case, the basic concept is the same, except that the connection pitch between the liquid crystal panel and the driver 2 is fixed. Also, the driver 2 having a binary output value has been described, but the concept is the same when the driver 2 has a multi-value output.

Hereinafter, the details of equalizing the output load of the driver 2 will be described. Leading wiring pattern 13 of transparent electrode 4
The resistance value Rc of the wiring resistance 9 is calculated by the following equation (1). Rc = (r × L) / (W × t) (1) where r is the specific resistance of the transparent electrode 4, L is the line length, W is the line width, and t is the film thickness.

As shown in the above equation (1), the resistance value Rc of the wiring resistor 9 of the lead wiring pattern 13 is
Is made thicker and shorter, and the specific resistance value is decreased, the value decreases. Therefore, in the conventional liquid crystal display device, the line width W, the line length L, and the non-resistance r of the transparent electrode 4 are adjusted to average the resistance value Rc of the wiring resistance 9 of the lead-out wiring pattern 13, or The slope of the resistance value Rc is made as small as possible.

The wiring resistance of the power supply section of the driver 2
7 is to minimize the wiring resistance Rc of the lead-out wiring pattern 13 of the transparent electrode 4 of the liquid crystal panel as much as possible, to make the output driving capability uniform, and to reduce the output load and output capability of the driver 2 as much as possible. It is based on uniformity. Here, the voltage applied to the liquid crystal layer of the n-th line from both ends is obtained by the following equations (2) and (3).

VH (n) = VH−Σ [n × Rline (VH) (VH−VL)] / [2 × (Rline (VH) + Ron + Rc + Rst)] (2) VL (n) = VL −Σ [n × Rline (VL) (VH−VL)] / [2 × (Rline (VL) + Ron + Rc + Rst)] (3) where Rline (VH) is the VH power supply wiring resistance and Rline ( VL) is the VL power supply wiring resistance, Ron is the output ON resistance, and Rst is the wiring resistance of the transparent electrode straight line portion. Equation (2) above,
As is apparent from the equation (3), the voltage applied to the liquid crystal layer 5 changes depending on the values of the power supply wiring resistances 6 and 7 of the driver 2, the output ON resistance 8 of the driver 2, and the wiring resistance 9 of the lead wiring pattern 13. .

That is, the power supply wiring resistance V of the driver 2
Due to H and VL, the voltage at the center decreases with respect to the power supply end side. Also, the higher the value of the output ON resistance 8 of the driver 2 and the value of the wiring resistance 9 of the lead wiring pattern 13, the lower the voltage applied to the liquid crystal layer.

[0011]

However, in forming the electrodes, the printed resistance is formed by etching, and the maximum and minimum values are determined by the etching ability. Whether or not the resistance value Rc of the lead-out wiring pattern 13 can be made uniform is determined by the number of outputs of the driver 2, the pixel pitch of the liquid crystal panel, and the connection pitch.

FIG. 3 shows the relationship between the number of outputs of the driver 2, the resistance value Rc of the wiring resistor 9 of the lead-out wiring pattern 13, and the pixel pitch. The connection pitch is fixed at 70 μm, and the value of 0 at the center is the center of the lead-out wiring along the line aa ′ in FIG. 2B, and the output number is symmetrical from the line aa ′. This shows how the number is increasing. As is clear from FIG. 3, if the pixel pitch is the same value, the smaller the number of outputs of the driver 2, the more the resistance value Rc of the wiring resistance 9 of the lead-out wiring pattern 13 can be averaged. In addition, the smaller the pixel pitch is, the easier the resistance value Rc of the wiring resistance 9 of the lead wiring pattern 13 is to be averaged.

That is, when a driver having a large pixel pitch is connected to the multi-output fine-pitch driver 2, it is no longer possible to equalize the resistance value. FIG. 4 shows the relationship between the number of outputs of the driver 2, the resistance value Rc of the wiring resistor 9 of the lead-out wiring pattern 13, and the connection pitch. Note that the pixel pitch is fixed at 0.3 mm, and the value of 0 at the center is shown in FIG.
At the center of the lead-out wiring along the line aa ′ of FIG.
This shows how the number of outputs increases from the -a 'line to the left and right.

As is clear from FIG. 4, when the number of outputs of the driver 2 is the same, the larger the connection pitch, the more the extraction resistance value can be averaged. Thus, driver 2
If the output load of the driver 2 is extremely inclined, the output waveform of the driver 2 becomes different between a place where the load is heavy and a place where the load is light, causing a difference such as an effective value difference, which causes a problem such as a shade difference on a display screen.

In order to drive a pixel having a large pixel pitch as a uniform load, it is conceivable to change the direction of increasing the connection pitch or reduce the number of outputs of the driver 2. However, when the connection pitch is changed, The tape carrier 3 for connection and the driver 2 itself become large in area, and a routing space on the tape carrier 3 is required, which causes disadvantages in terms of cost and compactness.

Also, when the number of outputs of the driver 2 is reduced, disadvantages are caused because the number of materials and the number of steps are increased. The present invention solves the above-mentioned problems, and even when a pixel having a large pixel pitch is connected to a multi-output fine-pitch liquid crystal driving driver, the output load of the liquid crystal driving driver is made substantially uniform, thereby reducing the cost. And to provide a compact liquid crystal display device.

[0017]

According to the present invention, a driver for driving a liquid crystal controls a wiring resistance of a power supply wiring pattern.
The output load is configured to be substantially uniform. According to this configuration, when this liquid crystal driving driver is mounted on a liquid crystal panel to form a liquid crystal display device, an inexpensive and compact liquid crystal display device can be provided.

[0018]

According to a first aspect of the present invention, there is provided a driver for driving a liquid crystal, wherein a pitch of an output wiring is narrower than a pixel pitch of a liquid crystal panel connected to the output wiring. An output circuit in which a driver output is connected to an electrode portion at the other end of each lead-out wiring pattern, one end of which is connected to a gate wiring or a signal wiring of the liquid crystal panel having a matrix structure, and a power supply is supplied to the plurality of output circuits. The wiring resistance of the power supply wiring pattern for supplying the wiring pattern is changed so as to correct the inclination tendency of the wiring resistance in the arrangement direction of each of the lead wiring patterns.

According to a second aspect of the present invention, in the liquid crystal driving driver, the power supply wiring resistance is set by changing the wiring width of the wiring resistance of the power supply wiring pattern. According to a third aspect of the present invention, in the liquid crystal driving driver, the driving capability of the output circuit is changed so as to correct the inclination tendency of the wiring resistance in the arrangement direction of the lead wiring patterns.

The liquid crystal display device according to the fourth aspect is the first aspect.
A liquid crystal driving driver is mounted on a liquid crystal panel. Hereinafter, embodiments of the present invention will be described. (Embodiment 1) In this (Embodiment 1), a driver 2 for driving a liquid crystal in which a pitch of a power supply wiring pattern 12 which is an output wiring is narrower than a pixel pitch of a liquid crystal panel connected to the output wiring is used. When connected to a liquid crystal panel, the difference is that the output load of the liquid crystal driving driver 2 is made substantially uniform, but the other basic configuration is almost the same as the above-described conventional example.

More specifically, each lead-out wiring pattern 13 having one end connected to a gate wiring or a signal wiring of a liquid crystal panel.
An output circuit is provided in which the liquid crystal driving driver 2 is connected to the electrode portion at the other end via the power supply wiring pattern 12. In this liquid crystal display device, the voltage applied to the liquid crystal layer on the n-th line from both ends is expressed by the above formulas (2) and (3), and the resistance value Rline ( V
H), Rline (VL), the resistance value Ron of the output ON resistor 8 of the driver 2, and the resistance value Rc of the wiring resistance 9 of the lead wiring pattern 13 change the voltage applied to the liquid crystal layer.

Due to the resistance values Rline (VH) and Rline (VL) of the power supply wiring resistances 6 and 7 of the driver 2, the voltage at the central portion drops with respect to the power supply end side. Also, the output ON resistance 8 of the driver 2
The higher the resistance value Ron and the higher the resistance value Rc of the wiring resistance 9 of the lead-out wiring pattern 13, the lower the voltage applied to the liquid crystal layer. Therefore, the inclination tendency of the resistance value Rc of the wiring resistor 9 of the power supply wiring pattern 12 for supplying power to the plurality of output circuits is corrected. This correction can be easily realized by changing the wiring width of the wiring resistance 9 of the power supply wiring pattern 12. That is, with respect to the inclination of the resistance value Rc of the wiring resistance 9, the resistance values Rli of the power supply wiring resistances 6 and 7 of the driver 2 are changed.
ne (VH), Rline (VL)
The voltage applied to the liquid crystal layer can be made uniform.

A liquid crystal display device in which the driver 2 configured as described above is mounted on a liquid crystal panel is a multi-output liquid crystal driving driver with a fine pitch even when the pixel pitch is large, and can perform uniform display without any problem, and is inexpensive. A compact liquid crystal display device can be obtained. (Embodiment 2) This (Embodiment 2) is different in that the drivability of the output circuit is changed so as to correct the inclination tendency of the wiring resistance in the arrangement direction of the lead-out wiring patterns 13.

More specifically, as shown in FIGS. 3 and 4, for example, the resistance value Rc of the wiring resistor 9 increases as the distance from the central portion A in the directions of arrows B and B 'increases. In the above-mentioned conventional example, the drive capability of the output circuit is the same at both the central portion A and the location away from the central portion A in the directions of arrows B and B ', that is, the resistance value Ron of the output ON resistor 8 of the driver.
Is used uniformly.

However, in this (Embodiment 2),
At a location distant from the central portion A in the directions of arrows B and B ', the driver 2 having the same input but having a larger output capability than the central portion A
Use As described above, the resistance value Ron of the output ON resistance 8 of the driver 2 is changed to the resistance value Ro of the output ON resistance 8 of the central portion A.
By making the resistance value Ron of the output ON resistance 8 of the driver larger than n and having a reverse slope so as to offset the wiring resistance slope of the routing part of the transparent electrode 4, the voltage applied to the liquid crystal layer can be uniform. You can do it.

[0026]

As described above, according to the liquid crystal driving driver of the present invention, the pitch of the output wiring is narrower than the pixel pitch of the liquid crystal panel connected to the output wiring. An output circuit in which a driver output is connected to an electrode portion at the other end of each lead-out wiring pattern, one end of which is connected to the gate wiring or the signal wiring of the liquid crystal panel having a matrix structure in which a gate wiring and a signal wiring are provided; This liquid crystal driving driver is mounted on a liquid crystal panel by changing the wiring resistance of the power supply wiring pattern for supplying power to the circuit so as to correct the inclination tendency of the wiring resistance in the arrangement direction of the respective lead wiring patterns. When a liquid crystal display device is used, even if the pixel pitch is large, a multi-output liquid crystal drive driver with a fine pitch enables uniform display without any problem. Ri, it can be an inexpensive and compact liquid crystal display device.

[Brief description of the drawings]

FIG. 1 is a plan view and a side view of a liquid crystal display device.

FIG. 2 is an equivalent circuit diagram of a liquid crystal display device and an enlarged view of a main part of a liquid crystal display element.

FIG. 3 is a diagram showing a relationship between the number of outputs of a liquid crystal driving driver, the resistance value of wiring resistance of a lead wiring pattern, and a pixel pitch.

FIG. 4 is a diagram showing a relationship between the number of outputs of a driver for driving a liquid crystal, the resistance value of wiring resistance of a lead wiring pattern, and a connection pitch.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 glass substrate 2 liquid crystal driving driver 3 tape carrier 4 transparent electrode 5 liquid crystal 6 VH power supply wiring resistance 7 VL power supply wiring resistance 8 output ON resistance 9 wiring resistance of lead wiring pattern 10 resistance of linear part of transparent electrode 11 between opposing electrodes Capacity 12 Power supply wiring pattern 13 Leader wiring pattern

Continued on the front page F-term (Reference) 2H092 GA41 GA44 GA45 GA50 NA01 PA06 2H093 NC10 NC12 ND05 ND09 NE03 NH06 5C006 BB11 BC02 BC21 FA37 5C080 AA10 BB05 DD05 DD22 DD27 JJ03 JJ05 JJ06 5G435 AA00 AA18 BB12 EE33 EE33H

Claims (4)

[Claims] 1. A liquid crystal driving driver wherein the pitch of output wiring is narrower than the pixel pitch of a liquid crystal panel connected to the output wiring, wherein the gate wiring and the signal wiring have a matrix structure. An output circuit in which a driver output is connected to an electrode portion at the other end of each lead-out wiring pattern having one end connected to a wiring or a signal wiring is provided, and the wiring resistance of a power supply wiring pattern for supplying power to the plurality of output circuits is set as described above. A liquid crystal driving driver that is different so as to correct the inclination tendency of the wiring resistance in the arrangement direction of each lead wiring pattern. 2. A liquid crystal driving driver wherein a power supply wiring resistance is set by changing a wiring width of a wiring resistance of a power supply wiring pattern. 3. A liquid crystal driving driver in which the driving capability of an output circuit is changed so as to correct the inclination tendency of the wiring resistance in the arrangement direction of the lead wiring patterns. 4. A liquid crystal display device comprising the liquid crystal driving driver according to claim 1 mounted on a liquid crystal panel.