JP4252478B2 - Display device - Google Patents

Description

  The present invention relates to a display device, and is particularly suitable for a liquid crystal display device that drives a display element of a liquid crystal panel having a matrix electrode structure by a multiplex drive method.

As shown in FIG. 5, a liquid crystal display device having a matrix electrode structure is a signal side liquid crystal drive IC that outputs a voltage corresponding to display signal data to panel terminals formed at the two edges of the liquid crystal panel 1. A scanning side liquid crystal driving IC (hereinafter referred to as COM driver IC) 3 is connected to 2 (hereinafter referred to as SEG driver IC).
The gray-scale display / RGB color compatible SEG driver IC 2 generally has 240 output terminals, and the display data of 8 dots or 12 dots per clock is sequentially input to the input terminal from the outside of the substrate 5 side. The mainstream is that the data for one line is output to the liquid crystal panel 1 each time it is stored in the driver IC.

  For example, when driving a color liquid crystal panel 1 having 800 × RGB (H) × 480 (V) dots and a dot pitch of 0.24 × 0.24 mm, ten 240-output SEG driver ICs 2 are used. . At this time, a TCP (Tape Carrier Package) 4 is used to draw a signal line from the chip of the SEG driver IC 2 and connect it to the liquid crystal panel 1. This TCP connection method uses an expensive FPC (flexible printed circuit board), but the SEG driver on the liquid crystal panel 1 is different from the COG (Chip On Grass) connection method in which the driver IC is directly connected to the liquid crystal panel without using the FPC. Since the area R1 for connecting the IC 2 is reduced, the liquid crystal panel 1 can be reduced in size by narrowing the frame of the liquid crystal panel 1, and the cost of the liquid crystal panel 1 can be reduced. For this reason, the TCP method is generally widely used for liquid crystal display devices having medium-sized screens or more that require connection of 3 to 4 or more driver ICs on one side. The width of the wiring region R2 on the liquid crystal panel 1 side is 3 mm, and the output terminal pitch of the TCP 4 is 0.07 mm.

  When connecting the SEG driver IC 2 and the monochrome liquid crystal panel 1, it is ideal that the output terminal interval of the SEG driver IC 2 and the display dot interval of the liquid crystal panel 1 are approximate values. As described above, the fan-shaped TCP 8 is used to widen the output interval from the SEG driver IC 6 having a narrow output interval by the FPC 7, and after the output of the TCP 8 is received by the panel terminal, the wiring form of the wiring region R3 on the liquid crystal panel 1 side In addition to expanding to the dot interval. In this case, the output terminal pitch of the TCP 8 is 0.021 mm, and the width of the wiring region R3 on the liquid crystal panel 1 side is 3 mm.

In the past, when black and white liquid crystal display devices were mainstream, the size of the SEG driver IC chip itself was large, so the output pitch of TCP was inevitably wide, and the wiring area on the liquid crystal panel side was also a relatively short distance to the dot interval. I was able to wire.
However, in recent SEG driver ICs, the chip size has been reduced by the miniaturization technology of semiconductor manufacturing, and the cost has been reduced accordingly. In addition, in order to increase the added value of liquid crystal display devices, high-performance liquid crystal display devices have been developed mainly for high-definition color liquid crystal display devices having a 1/3 black / white dot interval.

By the way, when trying to develop a monochrome liquid crystal having the same screen size and the same number of pixels as the color liquid crystal using the same technology as the color liquid crystal with the current technology, the following method can be considered.
(1) As shown in FIG. 6, the output interval is widened inside the FPC in which the SEG driver IC is mounted. (The wiring area on the liquid crystal panel side is equivalent to the color liquid crystal.)
In this case, the FPC must be newly developed for black and white, resulting in an increase in cost. In addition, although FPC is expensive, a large FPC must be used in order to widen the wiring, resulting in an increase in cost. Since black and white liquid crystal is required to be significantly lower in cost than color liquid crystal, it can be said that this method, which has a large cost increase factor, deviates from commerciality.

(2) As shown in FIG. 8, the output interval is increased to the dot interval depending on the wiring configuration of the wiring region inside the liquid crystal panel 8. (The SEG driver IC FPC is the same as the color liquid crystal.)
In this case, the width of the wiring region R4 on the liquid crystal panel 9 side becomes 11 mm, and the wiring inside the color liquid crystal panel ideally connected at the shortest distance from the output terminal of the SEG driver IC shown in FIG. About four times as many wiring regions R4 are required inside the panel as compared with the region, resulting in a wider frame. As a result, the outer shape of the liquid crystal panel becomes large, which causes a problem that the outer shape of the monochrome liquid crystal panel becomes too large compared to the outer shape of the color liquid crystal panel. Moreover, since the panel external shape per liquid crystal panel becomes large, the number of panels cut out from a single mother glass is reduced, resulting in an increase in cost.

As is common to the examples of FIGS. 6 and 8, when four 240-output SEG driver ICs are used in a monochrome liquid crystal panel of 800 (H) × 480 (V) dots, the total number of driver outputs is 960. Become. Japanese Patent Application Laid-Open No. 7-301820 proposes a method of connecting a flexible substrate by providing a dummy terminal on the substrate of the liquid crystal panel when the number of output terminals and panel terminals of the flexible substrate does not match. Yes.
When the technique of the above publication is applied to a monochrome liquid crystal panel of 800 (H) × 480 (V) dots, since the output of three SEG driver ICs is 240 outputs × 3 = 720 outputs, the last fourth SEG driver The number of outputs connected from the IC to the liquid crystal panel is 80. However, if the number of outputs per driver is made non-uniform as in the above publication, the load per driver IC is different by one, which causes a problem of display unevenness in each driver IC. It is not possible to use a technique such as that of 7-301820.

(3) Next, when considering the case where the same number of SEG driver ICs as the color liquid crystal shown in FIG. 5 are connected to the liquid crystal panel, the outer shape of the black and white liquid crystal panel is the same as the color, as shown in FIG. The SEG driver IC output is connected to the panel terminal of the liquid crystal panel by repeating one connection and two non-connections (dummy).
The standard interface for the external data input interface of the SEG driver IC is generally a method of “sequentially inputting display data of 8 dots or 12 dots per clock from the outside” due to restrictions on the specifications of the SEG driver IC.

In this method, the SEG driver IC is set and used in a mode in which display data of 12 dots is sequentially input. However, when the driver output is repeated with one connected and two not connected (dummy), only 1/3 of the liquid crystal is used. Since it is not connected to the panel, the specification is “sequentially input display data of 4 dots per clock from the outside”. This is different from the method of “sequentially inputting display data of 8 dots or 12 dots per clock from the outside” which is the specification of the color liquid crystal SEG driver IC, so the number of signals of the input interface is different, and black and white and color are different. The commonality of the interface signal is lost, and the disadvantage is that it is difficult for the user to accept.
JP-A-7-301820

  The present invention has been made in view of the above-described problems. The signal side driver IC is shared, the display panel is prevented from being widened, and the signal side driver IC is shared with a standard external data input interface. The issue is to secure the sex.

In order to solve the above problems, the present invention provides a display device in which a panel terminal of a display panel and an output terminal of a signal side driving IC are connected.
The output terminal group of the signal side driver IC provides a display device characterized in that two effective electrodes and one dummy electrode are alternately and periodically arranged.
The display panel is preferably a liquid crystal panel, and the signal side driving IC is preferably a signal side liquid crystal driving IC.

  With the above configuration, since the dummy electrode is provided at the output terminal on the signal side drive IC side, the signal side drive IC designed for high-definition display is used as it is, and the number of display pixels and the display pixel density are low. The display panel can be shared. Furthermore, since the interval between the output terminals from the signal side driving IC is increased by 3/2 times by setting the output terminal of the signal side driving IC to be periodically connected between two connections and one non-connection (dummy), An increase in the width of the wiring area on the display panel side can be suppressed to achieve a narrow panel frame, and a reduction in the number of panels that can be cut out from one mother glass can be prevented.

  In addition, when the signal side drive IC is set to a mode in which 12-dot display data is sequentially input per clock, the effective electrode is 2/3 of all the output electrodes of the signal side drive IC. Can be matched with the standard interface of “sequentially input display data of 8 dots per clock from the outside” and contribute to the generalization of parts.

  A plurality of the signal side driving ICs are mounted, and the number of effective electrodes per one of the signal side driving ICs is all the same.

  With the above configuration, the number of effective outputs per signal side driving IC is uniform for all the signal side driving ICs, so that it is possible to prevent the occurrence of display unevenness in signal side driving IC units.

The signal side driver IC is TAB mounted on a flexible printed circuit board to form a TCP, and the output terminal of the TCP is preferably connected to the panel terminal of the display panel.
That is, the use of TCP mounting is preferable because the display panel can be narrowed compared to COG mounting or the like.

Next, as a specific arrangement of effective and dummy output electrodes of the signal side driving IC,
For the output terminal group of the signal side driving IC, two effective electrodes are arranged on the outermost electrode on the data input start side, and thereafter, one dummy electrode and two effective electrodes are alternately arranged. It is good to arrange in.

Alternatively, with respect to the output terminal group of the signal side driving IC, one effective electrode is arranged at the outermost electrode on the side where data input is started, and thereafter, one dummy electrode and two effective electrodes are sequentially arranged. May be arranged alternately.
Alternatively, with respect to the output terminal group of the signal side driving IC, one dummy electrode is arranged at the outermost electrode on the side where data input is started, and thereafter, two effective electrodes and one dummy electrode are sequentially arranged. May be arranged alternately.

  As is clear from the above description, according to the present invention, since the dummy electrode (non-connection) is periodically provided at the output terminal of the signal side driver IC, the SEG driver IC designed for high-definition display is used. Can be used in common for different display panels having a low number of display pixels and a low display pixel density. Further, since the interval between the output terminals from the signal side driving IC is widened, the width of the wiring region on the liquid crystal panel side is suppressed to be narrowed, and the panel can be narrowed to be cut out from a single mother glass. It is possible to prevent the number of panels from decreasing. Furthermore, by making the number of effective outputs per one of the plurality of signal-side drive ICs the same, the load on each signal-side drive IC becomes uniform, and the problem of display unevenness in the signal-side drive IC unit can be prevented. it can.

Embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a state in which TCP (Tape Carrier Package) 12 and 16 connected to substrates 15 and 16 are connected to two sides of a liquid crystal panel 11 constituting a liquid crystal display device.

  The liquid crystal panel 11 has a large number of dots (pixels) arranged in a matrix by enclosing a liquid crystal between glass substrates 21 and 22 arranged opposite to each other, and a backlight (see FIG. A polarizing film (not shown) for aligning the directions of the polarization planes of incident light and outgoing light from (not shown) is provided. Specifically, the liquid crystal panel 11 has a black and white of 800 (H) × 480 (V) dots and a dot pitch of 0.24 × 0.24 mm.

The signal side TCP 12 is sealed by mounting a signal side liquid crystal drive IC (hereinafter referred to as SEG driver IC) 13 on an FPC (flexible printed circuit board) 14 by a TAB (Tape Automated Bonding) method. The substrate 15 and the input terminal are connected.
The TCP 16 on the scanning side is sealed by mounting a scanning side liquid crystal driving IC (hereinafter referred to as a COM driver IC) 17 on the FPC 18 by the TAB method, and the gate side substrate 19 and the input terminal are connected.

  The output terminals of the TCPs 12 and 16 are connected to the panel terminal regions 21a and 22a of the liquid crystal panel 11 by thermocompression bonding via an anisotropic conductive film (ACF). This anisotropic conductive film is obtained by dispersing thousands to tens of thousands of conductive particles and insulating particles in an insulating synthetic resin (adhesive). The synthetic resin (adhesive) is a liquid crystal panel 11. The conductive particles serve to connect the panel terminals and the output terminals of the TCPs 12 and 16, and the insulating particles are short-circuited between the adjacent terminals by the conductive particles. Plays a role to prevent.

  The output terminal pitch of the TCP 12 on the signal side is 0.07 mm, and when applied to the monochrome liquid crystal panel 11, five SEG driver ICs 13 having 240 outputs are used as shown in FIG.

  The output terminal group of the SEG driver IC 13 of the TCP 12 has a configuration in which two effective electrodes and one dummy electrode are alternately and periodically arranged, and the number of outputs per one TCP 12 is the same. In detail, as shown in FIG. 2, two effective electrodes are arranged at the driver outputs 1 and 2 on the end side where data input of the output terminal group of the SEG driver IC 13 is started, and one dummy is sequentially arranged thereafter. Electrodes and two effective electrodes are alternately arranged. This is the same for all five SEG driver ICs 13.

In this case, the number of outputs per SEG driver IC 13 is 160 for all of the five SEG driver ICs 13, and the load on each SEG driver IC can be made uniform.
Further, the width of the wiring region R5 up to the display region 20 on the liquid crystal panel 11 side is 6 mm. When the output interval is extended to the dot interval according to the wiring configuration of the wiring region inside the liquid crystal panel 8 shown in FIG. 8, the width of the wiring region R4 on the liquid crystal panel 9 side is as large as 11 mm. The width can be reduced to almost half of the width, which contributes to a narrow frame of the liquid crystal panel 11. Therefore, it is possible to suppress a decrease in the number of panels taken from the mother glass due to the increase in size of the liquid crystal panel 11.
Furthermore, compared to FIG. 5 showing a color liquid crystal panel ideally connected at the shortest distance from the TCP output, the number of TCP12 (SEG driver IC13) used can be reduced by half and a monochrome liquid crystal display device can be realized. ing.

Further, when the SEG driver IC 13 is set to a mode in which 12-dot display data is sequentially input per clock, as shown in FIG. 2, the effective electrodes are 2/3 of all output electrodes of the SEG driver IC 13. It can be matched with the standard interface of LCD panel 11 "sequentially input display data of 8 dots per clock from the outside", and the common interface signal with color liquid crystal display device can be obtained. It becomes possible to contribute to the generalization of.
Further, the TCP 12 of the color SEG driver IC 13 has a high mass production quantity and is designed to minimize the FPC 14, so that the cost performance is good. In the monochrome liquid crystal of this embodiment, the TCP 12 of the SEG driver IC 13 for the color It is shared with.

  The above embodiment describes an 800 (H) × 480 (V) dot panel, but it can also be applied to other resolution liquid crystal panels such as 640 (H) × 480 (V). Needless to say.

FIG. 3 shows a first modification.
As shown in FIG. 3, the output terminal group of the SEG driver IC 13 of the TCP 12 has one effective electrode arranged at the output 1 at the extreme end on the side where data input of the output terminal group of the SEG driver IC 13 is started, and thereafter One dummy electrode and two effective electrodes are alternately arranged in this order.

FIG. 4 shows a second modification.
As shown in FIG. 4, in the output terminal group of the SEG driver IC 13 of the TCP 12, one dummy electrode is arranged at the output 1 at the extreme end on the data input side of the output terminal group of the SEG driver IC 13, and thereafter Two effective electrodes and one dummy electrode are alternately arranged in this order.

The present invention is a main part plan view of a liquid crystal display device of an embodiment. It is drawing which shows the correspondence of a driver output and a panel terminal. It is drawing which shows the correspondence of the driver output of 1st modification, and a panel terminal. It is drawing which shows the correspondence of the driver output of 2nd modification, and a panel terminal. It is a principal part top view of the liquid crystal display device of a prior art example. It is a principal part top view of the liquid crystal display device of another prior art example. It is drawing which shows the correspondence of the driver output and panel terminal of a prior art example. It is a principal part top view of the liquid crystal display device of another prior art example. It is drawing which shows the correspondence of a driver output and a panel terminal.

Explanation of symbols

11 Liquid crystal panel 12, 16 TCP
13 SEG driver IC (Signal side LCD driver IC)
14, 18 FPC (Flexible Printed Circuit Board)
15, 19 Substrate 17 COM driver IC (scanning side liquid crystal drive IC)
20 Display area 21, 22 Glass substrate 21a, 22a Panel terminal area R5 Wiring area

Claims (7)

In the display device in which the panel terminal of the display panel and the output terminal of the signal side driving IC are connected,
The output terminal group of the signal side driving IC has two effective electrodes and one dummy electrode alternately and periodically arranged.   The display device according to claim 1, wherein a plurality of the signal side driving ICs are mounted, and the number of effective electrodes per one of the signal side driving ICs is the same.   The display device according to claim 1, wherein the signal side driver IC is a TAB mounted on a flexible printed circuit board to form a TCP, and an output terminal of the TCP is connected to a panel terminal of the display panel.   For the output terminal group of the signal side driving IC, two effective electrodes are arranged on the outermost electrode on the data input start side, and thereafter, one dummy electrode and two effective electrodes are alternately arranged. The display device according to any one of claims 1 to 3, wherein the display device is disposed on the screen.   For the output terminal group of the signal side driver IC, one effective electrode is arranged at the outermost electrode on the data input start side, and thereafter one dummy electrode and two effective electrodes are alternately arranged. The display device according to any one of claims 1 to 3, wherein the display device is disposed on the screen.   For each output terminal group of the signal side drive IC, one dummy electrode is arranged at the end electrode on the data input start side, and thereafter, two effective electrodes and one dummy electrode are alternately arranged. The display device according to any one of claims 1 to 3, wherein the display device is disposed on the screen.   The display device according to any one of claims 1 to 6, wherein the display panel is a liquid crystal panel, and the signal side driver IC is a signal electrode side liquid crystal driver IC.

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