JPH1195241A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to effectively utilize the packaging rule which makes a contribution heretofore to increasing microminiaturization along with image quality improvement by connecting the electrodes of a liquid crystal panel to terminals having a pairing relation with the electrode driving output terminal groups and supporting terminal groups. SOLUTION: A scanning electrode driving IC 11 is packaged to a glass substrate. Power sources VDD, VM, VSS and signal input terminals CK, ST are connected to the wiring P31, 33, 35, 32, 34 of a glass substrate respectively on the short sides. Respective scanning electrodes C1 to C240 are connected to the scanning electrode driving output terminal T1 to T240 and the supporting terminal S1 to S240. Since the addressing function of the scanning electrode driving IC 11 is in one direction, the scanning electrodes C1 to C240 are sequentially selected from the scanning electrode C1 and erect images are displayed. The connection of the electrode wiring at a specified pitch to the electrode driving terminals is made possible in such manner and the variations of the wiring resistance are eliminated, by which the improvement in the image quality is eventually resulted. The terminals are paired and are connected to the electrodes, the degree of freedom of the electrode driving IC in the packaging direction is attained. The effective utilization of the packaging rule to make packaging finer is thus made possible.

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 device, and more particularly to a liquid crystal display device characterized by a terminal arrangement and a circuit of an electrode driving IC and a method of connecting terminals of the electrode driving IC to electrodes of a liquid crystal panel. Things.

[0002]

2. Description of the Related Art As the number of pixels of a liquid crystal panel increases, the number of electrodes driven by one electrode driving IC has also increased. For this reason, there has been a demand for a higher density connection between the electrode driving IC and the electrode of the liquid crystal panel. Glass in which the mounting substrate and the LCD screen are common as a method of responding to high-density connection in the method of making electrical connection by overlapping the connection part of the mounting substrate and the terminal surface of the electrode drive IC face to face There is a method (chip-on-glass, hereinafter referred to as COG) of mounting a connection portion of a substrate and an electrode driving IC face to face via a conductive material. This is because the electrode wiring on the glass can be finely patterned, so that an output terminal for driving the electrode is also arranged inside the connection surface of the electrode driving IC to promote the high density. In order to further reduce the size of the glass exterior of the part on which the electrode driving IC is mounted, we have a scanning electrode driving IC that inputs power and control signals from the short side.
C (Developed Japanese Patent Application Hei 5-23753, Japanese Patent Application Hei 6-52)
2977). Hereinafter, the mounting substrate will be described as a glass substrate, and the mounting method will be described as COG.

FIG. 7 is a schematic diagram showing a connection state between the above-described scan electrode drive IC 71 and a glass substrate, and is a view of the terminal surface of the scan electrode drive IC 71 from the back side of the glass substrate. The scanning electrodes C1, C2, C3,...
, T239, C240, and scanning electrode driving output terminals T1, T2, T3,.
T240 are respectively connected. Scan electrode drive IC7
1, the power supply terminals VD1, VD2, VS
2. VS1 and signal input terminals CK, ST are connected to transparent electrode (ITO) wirings P71, P72, P7 for connection to an external circuit.
5, P76, P73, and P74, respectively, and the signal input terminal RL2 is connected to the power supply terminal VS1 via a wiring P77. The scanning electrodes C1 and the like also include wirings connected to the scanning electrodes. However, since each wiring is connected to only one scanning electrode in the display screen, it is also referred to as a scanning electrode in the following description.

FIG. 7 shows a scanning electrode driving IC 71 on the left side of the screen.
Is equivalent to implementing. Output terminals T1, T2, ...
, T240 in the order of the scanning electrodes C1, C2,.
If a selected waveform is applied to 40, a normal image can be displayed. The scan electrode driving IC 71 reverses the transfer direction of the selection pulse, and scan electrodes C240, C239,..., C3, C
If the selection is made in the order of 2, C1, a vertically inverted image can be displayed.

When the scan electrode driving IC 71 of FIG. 7 is arranged on the right side of the screen, the scan electrodes C1, C2,.
9, C240 and output terminals T12, T
11,..., T230 and T229 are connected. The scanning electrode driving IC 71 has a high degree of freedom in the transfer direction of the selection pulse, and connects the signal input terminal RL2 to the power supply terminal VDD to change the output terminals T12, T11,.
T2, T1, T24, T23,..., T228,.
T218, T217, T240, T239, ..., T2
The selected waveform can be output in the order of 29. Thus, the selected waveforms are sequentially applied to the scan electrodes C1, C2,..., C240, and the normal screen display is performed. By reversing the selection order, reverse display can be performed. The scan electrode drive IC 71 has both the function of the normal display and the reverse display and the degree of freedom in the left and right mounting directions.

Here, the addressing function will be outlined. At the early stage of the development of the liquid crystal display device, the addressing function of the scan electrode driving IC was unidirectional, in which the scan electrodes were selected in order from the top to the bottom of the screen. Similarly, the addressing function of the signal electrode driving IC is a one-way function in which one line of image data is stored in the memory of each output block in order from the output block corresponding to the signal electrode at the left end of the screen. Was. After that, as liquid crystal devices became popular and electrode drive ICs became general-purpose components, the degree of freedom with respect to the mounting position and the vertical (or left / right) inversion display function were required, and both scan electrode drive ICs and signal electrode drive ICs were required. Now has a bidirectional addressing function.

FIG. 8 shows an addressing circuit using a shift register. 8A shows a one-way shift register, and FIG. 8B shows a two-way shift register.

In the one-way shift register of FIG. 8A, the same clock signal ck is applied to clock input terminals CK of 240 data type flip-flops (hereinafter referred to as D-FFs) D1, D2,. Is entered,
Except for the first and last D-FFs D1 and D240, the output terminal Q of the preceding D-FF is connected to the data input terminal D of the subsequent D-FF. A pulsed start signal st indicating the start of scanning is input to the data input terminal D of the D-FF · D1, and the D-FF · D1, D is synchronized with the clock signal ck.
The selection pulses are transferred in the order of 2,..., D240. Each of the D-FFs D1, D2, D3,.
, D239, output blocks B1, B2, B3,..., B2 for driving electrodes connected to the output terminals Q of D240.
39 and B240 are addressed.

The bidirectional shift register shown in FIG. 8B has D-FFs D1, D2, D3,..., D239, D24.
0, the selectors S1, S2, S3,..., S24
0 is arranged. Each selector S is controlled by the control signal rl.
1 to 240 select the input terminal B and output terminal Q of the preceding D-FF and input terminal D of the succeeding D-FF via the output terminal O.
Is connected, the start signal st is transferred in the forward direction as in (A). Each selector S1 is controlled by the control signal rl.
When 240 to 240 select the input terminal A and connect the output terminal Q of the succeeding D-FF and the input terminal D of the preceding D-FF via the output terminal O, the start signal st is transferred in the reverse direction to drive the electrode. Output blocks B240, B239,..., B
3, B2 and B1 are addressed in this order.

In the scan electrode driving IC 71, a greater number of selectors are added to the bidirectional register circuit of FIG. 9B to increase the degree of freedom in the transfer direction of the selection pulse. Further, a signal generated in the scan electrode driving IC 71 using the phase relationship of the signals input to the signal input terminals ST and CK,
The logic level of the signal input terminal RL2 is combined to control the selection pulse transfer direction of the shift register.

[0011]

The above-described scan electrode drive I
In C71, the output terminal group for driving the electrodes is arranged in the connection surface. Therefore, the wiring density has to be increased near the outlet of the electrode wiring from the electrode driving IC to the liquid crystal panel, and the line width has to be reduced. For this reason, there has been a problem that the wiring resistance is increased and the length of a thin wiring portion is different for each electrode, and the difference in wiring resistance is increased, thereby deteriorating the image quality.

Further, in the above-described scan electrode driving IC, the connection between the terminal group and the connection portion is secured by the conductive paste, so that the lower limit value of the pitch between the terminals is about 150 μm. However, recently, anisotropic conductive films (hereinafter, referred to as ACF, anisotropic conductive films) have been used in place of the conductive paste, and the lower limit value of the pitch between terminals has been reduced to about 40 μm. There has been a need for a connection method that can utilize the mounting rules that have been miniaturized by changing the output terminal arrangement.

Accordingly, an object of the present invention is to provide a liquid crystal display device which aims at improving the image quality and utilizing the miniaturized mounting rules.

The above-described scan electrode driving IC 71 has been increased in circuit scale in order to have versatility in the addressing direction and the mounting position. For this reason, the number of elements has increased, and the area of the electrode driving IC has increased, which has gone against the miniaturized mounting rules. On the other hand, it is necessary to maintain the functions of the current electrode drive IC.

Accordingly, claims 2, 3, 4, 5 of the present invention.
Another object of the present invention is to provide a liquid crystal display device which solves the problem of increasing the size and maintaining the function of an IC in addition to the object described in claim 1.

[0016]

According to the present invention, an electrode driving IC has an electrode driving output terminal group, a supporting terminal group, and other terminal groups. The output terminal group for electrode driving is arranged on one long side of the electrode driving IC, the terminal group for supporting is arranged on the other long side, and the other terminal group is arranged on the short side of the electrode driving IC. Side by side,
Each terminal of the electrode drive output terminal group and the support terminal group is arranged at equal pitch in the long side direction to form a pair, and the electrodes of the liquid crystal panel are paired with the electrode drive output terminal group and the support terminal group. Are connected to terminals having the relationship

According to another aspect of the present invention, in order to achieve the objects of claims 2, 3, 4 and 5, the output terminal group for driving the electrode and the terminal group for support are rotationally symmetric. The electrode driving IC has a one-way addressing function, and the electrode driving IC is rotated by 180 ° to mount a normal display and mounted on the connection portion to perform inverted display.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS When an ACF is used in a COG mounting method, pressure is applied when mounting an electrode driving IC.
For this reason, if the terminals concentrate on a part of the electrode driving IC, the pressure distribution at the time of pressurization becomes uneven. Therefore, in the case where the terminals tend to be biased in one direction, such as an electrode driving IC, a supporting terminal for making the pressure distribution uniform is required.

FIG. 1 is a schematic diagram showing a terminal arrangement of the scan electrode driving IC 11 according to the first embodiment of the present invention. Output terminals T1, T2, T
3, T4, ..., T237, T238, T239, T2
Numerals 40 are arranged in a row on the long side on the right side of the scan electrode driving IC 11. Terminals S1, S2, S3,
S4,..., S237, S238, S239, S240
Are arranged in a line on the long side on the left side of the scan electrode driving IC 11. On the short side on the upper side of the scan electrode driving IC 11, power supply terminals VDD, VM, VSS and signal input terminals CK, ST are arranged as other terminal groups. Scan electrode drive IC1
A terminal having the same name as the upper side is disposed on the lower side of the lower side of 1. Those having the same name have the same function because they are connected inside the scan electrode driving IC 11.

In FIG. 1, electrode driving terminal groups T1-2.
The terminals are arranged at a constant pitch in the terminal group 40 and the supporting terminal groups S1 to 240, and the terminals (T1 and C1
1) are paired at the same height with reference to the lower short side of the electrode driving IC 51. The electrode drive terminal groups T1 to 240 and the support terminal groups S1 to 240 are rotationally symmetric about the center of the electrode drive IC 11. Furthermore, power supply terminals VDD, VM, VSS,
The signal input terminals CK and ST are also rotationally symmetric about the center of the scan electrode driving IC 11 as an axis.

FIG. 2 is a circuit diagram of the scan electrode driving IC 11 focusing on the addressing function. FIG.
FIG. 8A is a circuit similar to FIG. 8A, and the same symbols as in FIG. 8A indicate the same terminals, signals, and blocks. Output blocks B1 to B24 for driving scan electrodes connected to a one-way shift register
In addition to the selection pulse, a signal df for controlling the polarity of the selection pulse, a power supply vdd which is the highest potential of the selection pulse,
A minimum potential vss of the selection pulse and a power supply vm which is a potential applied to the scan electrode when not selected are also input. The signal df is composed of a start signal st and a clock signal ck.
And the logic level of the power supply vm with respect to the power supplies vdd and vss. Each of the output blocks B1 to 240 has an output terminal T1 for driving a scan electrode.
To 240 to output the scan electrode drive waveform.

FIG. 3 is a schematic diagram when the scan electrode driving IC 11 of FIG. 1 is mounted on a glass substrate on the left side of the screen. The dotted line indicates the wiring of the transparent electrode on the glass substrate, and is a view of the terminal surface viewed through the glass substrate. Power supply VD
D, VM, VSS, and signal input terminals CK, ST are wirings P31, P33, P
35, P32 and P34.

In FIG. 3A, each of the scanning electrodes C1, C2, C3, C4,..., C237, C238,.
C239 and 240 are output terminals T1 for driving scan electrodes,
T2, T3, T4, ..., T237, T238, T23
9, T240 and supporting terminals S1, S2, S3, S4,
.., S237, S238, S239, and S240. Since the addressing function of the scan electrode driving IC 11 is in one direction, the scan electrodes C1 to 240 are sequentially selected from the scan electrode C1 and display a normal image.

FIG. 3B shows the configuration of the scan electrode driving IC
It is mounted on a glass substrate by being rotated by 0 °. Since the arrangement of the output terminal group for scanning electrode drive and the other terminal groups is symmetrical about the center, they are mounted on the connection portions of the wirings P31 to P35 and the connection portions of the scan electrodes C1 to 240 on the same glass substrate as in FIG. It becomes possible. Each scanning electrode C1, C
2, C3, C4, ..., C237, C238, C23
9, C240 is an output terminal T240 for driving the scan electrode,
T239, T238, T237, ..., T4, T3, T
2, T1 and supporting terminals S240, S239, S23
8, S237,..., S4, S3, S2, and S1. The addressing function of the scan electrode driving IC 11 is 1
Direction, so that the scanning electrodes C1 to 240 are
Are selected in order from, and a vertically inverted image is displayed.

FIG. 4 is a schematic diagram showing a case where the scanning electrode driving IC 11 is mounted on a glass substrate on the right side of the screen. Power supply VD
D, VM, VSS, and input signal terminals CK, ST are wirings P41, P43, P
45, P42 and P44. Each of the scanning electrodes C1, C2, C3, C4,..., C237, C23
8, C239 and 240 are output terminals T for driving the scan electrodes.
1, T2, T3, T4, ..., T237, T238, T
239, T240 and supporting terminals S1, S2, S3, S
4,..., S237, S238, S239, and S240. FIG. 3A shows scanning electrodes C1 to 240.
Direction is different. Since the addressing function of the scan electrode driving IC 11 is in one direction, it is selected in order from the scan electrode C1 and displays a normal image as in FIG.

FIG. 5 shows the scan electrode drive I of the second embodiment.
It is a schematic diagram which shows C51 and its connection situation. This scan electrode drive IC 51 is the scan electrode drive IC of the first embodiment.
The power supply terminals VDD, VM, VSS and the signal input terminals CK, ST on the short side on the lower side from 11 are removed to shorten the long side. The same symbols as those in FIG. 3 denote the same terminals and wirings as viewed from the terminal surface of the scan electrode driving IC 51 from the back side of the glass substrate. FIG. 5A shows an arrangement for displaying a normal image, in which power supply terminals VDD, VM, VSS and signal input terminals CK, ST are connected to wirings P50, 52, 54, 51, 53 on the upper part of the glass substrate, respectively. Connect with FIG. 5B shows an arrangement for displaying an image inverted upside down, in which the power supply terminals VDD, VM, VSS and the signal input terminals CK, ST are connected to the lower wirings P59, P on the glass substrate.
57, P55, P58, and P56. in this case,
Wirings P50 to P59 are prepared in advance on the glass substrate in order to ensure the function of turning upside down.

FIG. 6 is a schematic diagram showing a connection state when the scan electrode driving ICs 61 and 62 according to the third embodiment are connected in cascade.
1, 62 are viewed from the terminal surface. The same symbols as those in FIG. 3 indicate equivalent terminals, wirings, and electrodes. Power supplies vdd, vm, vss and a signal ck, which are supplied from an external circuit,
st (see FIG. 2) is the wiring P60, P6 at the top of FIG.
2, scan electrode drive IC via P64, P61, P63
Input to 61. Compared to the scan electrode driving IC 11 of FIG. 1, the terminal arrangement on the lower side of the scan electrode drive IC 61 is different, and the signal input terminal S on the lower side of the scan electrode drive IC 11 is different.
T is the scanning electrode driving IC of the next stage in the scanning electrode driving IC 61
The signal is changed to the carry signal output terminal CO for starting 62. Power supply terminal V of scan electrode drive ICs 61 and 62
DD, VM, VSS and the signal input terminal CK are connected to a wiring P65,
Since they are connected by P67, P69, and P66, the same power supply vdd, vm, vss and clock signal ck are supplied to the scan electrode driving ICs 61 and 62. Since the signal output terminal CO of the scan electrode drive IC 61 and the signal input terminal ST of the scan electrode drive IC 62 are connected by the wiring P67, the scan electrodes C241, C242, C243,. C244,... Are selected. To change the selection direction each scan electrode drive IC
Although it is sufficient to mount the components 61 and 62 by rotating them by 180 °, it is necessary to prepare wiring in advance on the lower side of the glass substrate similarly to the second embodiment of FIG.

The present invention can also be applied to a signal electrode driving IC, and the screen can be horizontally inverted. In addition to the COG mounting, a mounting method such as TAB (tape auto bonding) in which an electrode driving IC and a mounting substrate face each other and are connected to each other can be applied. In an addressing system using not only a shift register but also a counter and a decoder, the circuit can be simplified if the addressing function is made unidirectional. The output terminals for electrode drive and the terminals for support need not be at a constant pitch as long as they form a pair. The supporting terminals may be thinned out under conditions where there is no problem during pressurization.

[0029]

As described above, according to the first aspect of the present invention, since the electrode wiring can be connected to the electrode driving terminal at a constant pitch, the variation in wiring resistance can be eliminated, thereby improving the image quality. Connect. While using an ACF and arranging output terminals for electrode driving in a line on one side, the output terminal for pole driving and the terminal for support are paired and connected to the electrode of the liquid crystal panel, and the electrode driving IC can be freely mounted in the mounting direction. The increased degree of use enabled the use of miniaturized mounting rules.

According to a second aspect of the present invention, in addition to the effects of the first aspect of the present invention, the addressing function is limited to one direction, the circuit is simplified, and the number of elements is reduced.
Of the electrode drive ICs due to the effect that the area of the electrode drive IC can be reduced, the arrangement of the electrode drive ICs on the short side of the terminal group other than the electrode drive, and the rotationally symmetric arrangement of the electrode drive output terminal group.
This has the added effect of being able to perform the reverse display function when mounted with rotation by 0 °.

According to the third aspect of the present invention, since the terminal group arranged on the short side also has rotational symmetry in the effect of the second aspect of the present invention, even if the terminal group is rotated by 180 ° and mounted. This has the added effect that terminals on the short side can be connected while the wiring pattern on the board is shared.

The invention according to claim 4 is obtained by adding the effect of shortening the long side of the electrode driving IC to the effect of the invention according to claim 2.

According to the fifth aspect of the invention, the effect of the invention of the second aspect is added to the effect that a large number of electrodes can be driven by cascade connection.

[Brief description of the drawings]

FIG. 1 is a scanning electrode driving IC according to a first embodiment of the present invention;
FIG. 11 is a schematic diagram showing an arrangement of terminals 11;

FIG. 2 is a scan electrode drive IC according to the first embodiment of the present invention;
11 is a circuit diagram mainly illustrating an addressing function of the eleventh embodiment.

FIG. 3 is a scan electrode drive IC according to the first embodiment of the present invention;
11A and 11B are schematic diagrams illustrating a connection state when 11 is mounted on the left side of the screen, in which (A) a normal image is displayed and (B) a vertically inverted image is displayed.

FIG. 4 is a scan electrode driving IC according to the first embodiment of the present invention;
FIG. 11 is a schematic diagram showing a connection state when 11 is mounted on the right side of the screen.

FIG. 5 is a scan electrode drive IC according to a second embodiment of the present invention;
5A is a schematic diagram showing a connection state of 51, (A) when displaying a normal image, and (B) when displaying a vertically inverted image.

FIG. 6 is a scan electrode drive IC according to a third embodiment of the present invention;
The schematic diagram which shows the connection situation at the time of connecting 61 and 62 in tandem.

FIG. 7 is a schematic diagram showing a conventional scanning electrode driving IC 71 and a connection state thereof.

FIG. 8 is a circuit diagram of a conventional example having an addressing function,
(A) is a one-way shift register, and (B) is a two-way shift register.

[Explanation of symbols]

11, 51, 61, 62, 71 Scanning electrode driving IC VDD power supply terminal VM power supply terminal VSS power supply terminal CK signal input terminal ST signal input terminal CO signal output terminal T1 to T240 Scan electrode drive output terminals S1 to S240 Terminals C1 to C244 Scanning electrodes and wiring P31 to P77 Wiring

Claims (5)

[Claims] 1. A liquid crystal display device in which a connection portion of a mounting board and a terminal surface of an electrode driving IC are superposed face-to-face and electrically connected to each other, wherein the electrode driving IC includes an electrode driving output terminal group. It has a terminal group for support and another terminal group,
The output terminal group for driving the electrode is arranged on one long side of the electrode driving IC, the supporting terminal group is arranged on the other long side, and the other terminal group is the other terminal group. Electrode drive I
Arranged on the short side of C, the output terminal group for driving the electrodes and the terminals of the supporting terminal group form a pair in the long side direction,
A liquid crystal display device wherein electrodes of a liquid crystal panel are connected to a pair of terminals of the output terminal group for driving electrodes and the terminal group for support. 2. The electrode drive output terminal group and the support terminal group are rotationally symmetric, the electrode drive IC has a one-way addressing function, 2. The liquid crystal display device according to claim 1, wherein said electrode driving IC is rotated by 180 [deg.] And mounted on said connection portion to perform inverted display. 3. The liquid crystal display device according to claim 2, wherein the other terminal groups of the electrode driving IC also have rotational symmetry about a common axis with the output terminal group for driving the electrodes. 4. The liquid crystal display device according to claim 2, wherein the other terminal groups of the electrode driving IC are arranged only on one short side. 5. A first electrode driving IC and a second electrode driving IC
3. The liquid crystal display according to claim 2, wherein terminals facing each other across the short side of C are connected via wiring on a mounting board, and the first and second electrode driving ICs are connected in tandem. apparatus.