JP2507554B2 - Flat panel display - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a flat panel type display device such as a liquid crystal display device, and particularly to improvement of a mounting portion of a drive integrated circuit (hereinafter referred to as a drive IC). It is a thing.

[Conventional technology]

FIG. 6 is a diagram showing the structure of a conventional liquid crystal display device disclosed in, for example, Japanese Patent Laid-Open No. 59-210419, in which 1a is a TFT having a thin film transistor (hereinafter referred to as TFT) array. The array substrate 1b is a counter substrate, and the liquid crystal cell 1 is constituted by these. 2a is gate drive
ICs 2b are source driving ICs, and their output signals are supplied to the liquid crystal cell 1 through the wirings of the flexible substrates 3a and 3b. Reference numeral 4 is a printed circuit board, which is a drive IC for driving the drain power supply voltage V _DD , the source power supply voltage V _SS , the clock, and the video signal.
Transmits control signals for a and 2b.

FIG. 7 is a cross-sectional view showing a wiring portion of a conventional liquid crystal display device disclosed in, for example, Japanese Utility Model Laid-Open No. 61-126226, in which the source driving IC 2b is directly connected to a printed circuit board 3c and a flexible substrate. It is connected to the TFT array substrate 1a via 3d. The three source driving ICs 2b shown in the figure correspond to each color [red (R), green (G), blue (B)] of the color filter, and the terminal portion of the TFT array substrate 1a is the color of each color filter. Corresponding to, the terminals are configured in multiple stages on a plane.

[Problems to be Solved by the Invention]

Since the conventional flat panel type display device is configured as described above, in the structure shown in FIG.
Since b is arranged in the same plane as the liquid crystal cell 1, the area of the non-display area around the outer side of the effective display area becomes large, and not only can the size be reduced, but the area surrounding the display section can be larger than the display screen. Has a problem that it is not preferable in terms of appearance because it occupies a large proportion of the visual field. Further, in the structure of FIG. 7, since the source drive IC 2b control signal wiring is independent for each of the three printed circuit boards 3c, it is necessary to duplicate the signal lines common to the three source drive ICs 2b. There was a problem that could not be miniaturized.

Further, when the source driving ICs 2b stacked in multiple stages as shown in FIG. 7 are mounted on the device having the structure shown in FIG. 6, there is a problem that the liquid crystal cell 1 is bulged in the thickness direction and cannot be downsized. . Further, in order to avoid the protrusion, the printed circuit board 3c on which the source driving IC 2b mounted on the flexible substrate 3d is overlapped in a plurality of stages as shown in FIG. 7 and is connected to the TFT array substrate 1a through the flexible substrate 3d. Even if it is bent and mounted in the vicinity, the flexible board for connection at the bent portion has a problem in that it is difficult to hold these in terms of strength and the reliability of the connection deteriorates.

The present invention has been made to solve the above problems, and an object of the present invention is to obtain a flat panel type display device which can be downsized even with high definition and a high number of pixels and which is preferable in appearance.

[Means for solving the problem]

A flat panel type display device according to the present invention constitutes a display cell and a bent portion of an input flexible printed circuit board which is fixedly provided on a lower surface of a substrate constituting a display cell and has an opening corresponding to the display surface of the display cell. And a flexible printed circuit board on which a column driving integrated circuit is mounted, and the column driving integrated circuits are mounted in a plurality of stages in a plane substantially orthogonal to the display cell surface.

[Action]

In the flat panel display device according to the present invention, the column driving integrated circuit is mounted in a plurality of stages in a plane substantially orthogonal to the display cell surface without mounting it on the front surface of the panel, so that the effective display area becomes larger than the non-display area The appearance is favorable and the size can be reduced. In addition, an input flexible printed circuit board that has an opening corresponding to the display surface of the display cell and has an IC input bus line is formed on the lower surface of the substrate that constitutes the display cell in the peripheral area excluding the display portion of the display cell substrate. Because it was fixed,
It serves to mechanically hold the display cells and column drive integrated circuits.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an assembly diagram showing a mounting structure of a flat panel type display device according to an embodiment of the present invention, and FIG.
FIG. 3 is a partial cross-sectional view when viewed laterally from FIG. 1, and FIG. 3 is a partial cross-sectional view when viewed laterally from an arrow B orthogonal to the arrow A in FIG. 1 to 3, 11a is a TFT array substrate in which a TFT and a transparent pixel electrode connected to the drain electrode of the pixel and a row and column wiring are formed for each pixel, and 11b is a color filter and a counter electrode. The well-known liquid crystal cell 11 is constructed by further forming an alignment film on the TFT array substrate 11a and the counter substrate 11b, and by sandwiching a liquid crystal layer between them. Reference numeral 12a is a gate drive IC connected to the gate electrode of the TFT of the TFT array substrate 11a, and is connected by gang bonding or wire bonding to each film carrier 13a connected to a pair of opposite sides of the TFT array substrate 11a. There is. 12b is a source drive IC connected to the source electrode of the TFT of the TFT array substrate 11a,
12bR, 12bG, and 12bB drive pixels of R (red), G (green), and B (blue), respectively. 13b has T at each end
The source drive IC 12b is a flexible printed circuit board connected to the other pair of adjacent sides of the FT array substrate 11a.
Each is equipped with 3 layers. 14 is a flexible printed circuit board for IC input in which an IC input bus line is formed, and its opening is aligned corresponding to the display surface of the liquid crystal cell 11,
The liquid crystal cell 11 is mounted on the lower surface of the TFT array substrate 11a of the liquid crystal cell 11 by the resin body 17, and the vicinity of the connection portion with the source driving IC 12b is located in the liquid crystal cell 11
It has a bent portion 14a that is bent in a substantially right-angled direction. The other end of the flexible printed board 13b is connected to the bent portion 14a. With the above configuration, I
The flexible printed circuit board 14 for C input is integrated with the liquid crystal cell 11, and the flexible circuit board 13b on which the source driving IC 12b is mounted is directly connected to the TFT array substrate 11a and the bent portion 14a.
By being connected to, the reliability at the connection portion is secured.
Further, by this, the source driving IC 12b is connected to the IC input bus line of the IC input flexible printed board 14. Three
Flexible printed circuit board 13b configured in a stack
As the connecting portion at each end of the TFT array substrate 11a becomes closer to the outer peripheral edge portion of the TFT array substrate 11a, the connecting portion at each other end is located above the bent portion 14a, and the source driving IC 12b is stacked in three steps with the liquid crystal cell 11. It is mounted in a substantially orthogonal plane. Also, the film carrier 13a
Is also connected to the IC input flexible printed circuit board 14, the gate drive IC 12a is also connected to the IC input bus line, and is mounted in the same plane around the liquid crystal cell 11. 15 is IC
A backlight for illuminating the liquid crystal cell 11 from the side of the input flexible printed board 14, 16 is arranged behind the backlight 15, and the IC of the flexible printed board 14 for input of the IC
It is a control signal board connected to an input bus line. A polarizing plate (not shown) is provided so as to sandwich the liquid crystal cell 11 if necessary.

FIG. 4 is an explanatory view showing the color arrangement of pixels in a matrix and the terminal lead lines of the liquid crystal cell in this embodiment, and FIG. 5 is a plan view showing the terminal shape. In FIGS. 4 and 5, 18a is a gate wiring electrode terminal connected to the gate driving IC 12a, 18b is a source wiring electrode terminal connected to the source driving IC 12b, and is red (R), green (G), blue. Corresponding to (B), respective terminals 18bR, 18bg, 18bB connected to the source drive ICs 12bR, 12bG, 12bB are provided. Dummy terminals 18c and 18d are provided on the opposite side of the gate wiring electrode terminal 18a and the source wiring electrode terminal 18b. 19 is a pixel,
R, G, and B are alternately arranged in columns, and R, G, and B are alternately arranged in each row. The source wirings forming the signal column lines (column wirings) are drawn out in a zigzag pattern with the pixel 19 sandwiched between every three wirings, and are connected to the source wiring electrode terminals 18b. The gate wirings forming the scanning signal row lines (row wirings) are arranged with the pixel 19 in between.
Each book is drawn in a zigzag pattern and connected to the gate wiring electrode terminal 18a. The source wiring electrode terminal 18b is connected to the pixel 19
Are arranged in three stages corresponding to the three primary colors. Since the source wiring and the gate wiring are staggered, the pitch of the electrode terminals when connecting to the film carrier 13a or the flexible printed circuit board 13b can be increased, and the connection reliability and yield are improved. The dummy terminals 18c and 18d are used as probing pads for defect inspection (disconnection inspection, etc.) of the gate wiring and the source wiring. In addition, the gate wiring or the source wiring is used in the liquid crystal cell 11. When the wire is broken, a drive signal is input from the side opposite to the electrode terminal to be used as a redundant terminal pad for avoiding inability to drive due to a line defect.

Next, the operation will be described with reference to FIGS. 1 to 3. The drive IC control signal generated by the control signal board 16 is transmitted to the IC input bus line of the IC input flexible printed board 14. The gate drive IC control signal therein is transmitted to the gate drive IC 12a via the film carrier 13a. The gate drive signal as the scan drive signal output from the gate drive IC 12a is passed through the film carrier 13a and the liquid crystal cell 1
Supplied to 1. Further, the source drive IC control signal is transmitted to the source drive I via the flexible printed circuit board 13b via the IC input bus line of the IC input flexible printed circuit board 14.
Transmitted to C12b. The source drive signal as the display drive signal output from the source drive IC 12b is supplied to each pixel of the liquid crystal cell 11 via the flexible printed board 13b. The gate drive signal and the source drive signal are supplied to the TFTs in the liquid crystal cell 11 to control the energization / de-energization of these TFTs, and the dots corresponding to the energization / de-energization by the illumination from the backlight 15. Matrix display. In addition, when the source driving IC 12b drives the TFT through the source wiring, the source wiring is used in three columns on each side of the pixel 19 and a total of six columns on both sides as shown in FIGS. 4 and 5. Source drive IC
The clock required by 12b can be reduced to 1/6 of the clock frequency conventionally required. Even if a high-frequency clock having a large number of pixels and a clock frequency of, for example, 30 MHz is conventionally required, the source drive IC 12 according to this embodiment
The clock frequency of b becomes a low frequency of 5MHz, and the range of selection of the drive IC that can be used expands.

Although the bent portion 14a is bent on the side opposite to the liquid crystal cell 11 in the above embodiment, it may be bent on the liquid crystal cell 11 side.

Further, in the above embodiment, the active matrix type liquid crystal display device of the TFT drive is described as the display device.
2 such as MIM (metal insulator metal) method
A liquid crystal display device driven by a terminal element or a passive matrix type (dot matrix type) liquid crystal display device without a built-in active element may be used, and the same effect as that of the above-described embodiment is obtained.

The display device does not have to be a liquid crystal, and may be another flat display (thin display device) such as a plasma display or an electroluminescence display.

〔The invention's effect〕

As described above, according to the present invention, since the column driving integrated circuits are configured in a plurality of stages and are mounted in a plane substantially orthogonal to the display cell surface, a device having a large number of pixels and a large number of terminals can be mounted at high density. Therefore, there is an effect that the size can be reduced, and the area occupied by the display area on the front surface of the panel can be increased to obtain a preferable appearance. Furthermore, an input flexible printed circuit board having an opening corresponding to the display portion of the display cell and having the IC input bus line formed collectively is fixed to the lower surface of the substrate forming the display cell to provide a bent portion. , Flexible printed circuit board with column drive integrated circuit and TF
Since the T-array substrate and the bent part of the input flexible printed circuit board are connected, the common input bus line is
There is an effect that it can be integrated into one printed circuit board, the input flexible printed circuit board can mechanically hold the display cell and the column drive integrated circuit, and the reliability at the connection portion can be secured.

[Brief description of drawings]

FIG. 1 is an assembly drawing of an apparatus according to an embodiment of the present invention, and FIG.
FIGS. 3 and 4 are partial cross-sectional views of FIG. 1 viewed from the respective sides, FIG. 4 is an explanatory view showing the relationship between color wiring of pixels and terminal lead lines, and FIG. 5 is the terminal of FIG. FIG. 6 is a plan view showing the shape, FIG. 6 is a structural view showing a mounting structure of a conventional device, and FIG. 7 is a sectional view showing a mounting structure of another conventional device. In the figure, 11 ... Liquid crystal cell, 11a ... TFT array substrate, 11b ...
… Counter substrate, 12a …… Gate drive IC, 12b …… Source drive
IC, 13a …… Film carrier, 13b …… Flexible printed circuit board, 14 …… Flexible printed circuit board for IC input, 14a …… Bend, 15 …… Backlight, 16 ……
Control signal board. The same reference numerals in the drawings indicate the same or corresponding parts.

Claims (1)

(57) [Claims] 1. A row wiring terminal having a plurality of columns and a column wiring terminal having a plurality of columns are provided on a substrate forming a display cell, and a scanning drive signal is supplied to the row wiring terminal, In a display device for supplying a display drive signal from each column drive integrated circuit to each column wiring terminal to display a dot matrix, a substrate having an opening corresponding to the display surface of the display cell and constituting the display cell. A printed circuit board fixed to the lower surface of the column, an input bus line for transmitting a control signal for the integrated circuit is formed, and the display cell surface is provided near the wiring connection portion with the column driving integrated circuit. An input flexible printed circuit board having bent portions bent at substantially right angles and each of the column drive integrated circuits are mounted, and the drive integrated circuits are connected to the column wiring by connecting between the substrate and the bent portions. Edge And a plurality of three-dimensionally stacked flexible printed circuit boards connected to the input bus line, and the column drive integrated circuits are mounted in a plurality of stages in a plane substantially orthogonal to the display cell surface. A characteristic flat panel display device.