JPH0219888A - Planar display device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Summary] Regarding the improvement of the electromagnetic shielding effect of flat display devices such as plasma display devices, EMI
In order to provide a flat display device with improved countermeasures, an unconnected cable such as a flexible printed board that connects the terminal part of the drive electrode led out to the edge of the display panel to the drive circuit is inserted through a holding plate. In a display device that is pressed and connected to the display panel by a spring clip, a ground electrode consisting of a ground pad connected to the holding plate and a ground terminal portion connected to the connection cable is provided on the display panel, and the ground The holding plate and the ground lead-out pattern of the flexible printed board are connected via electrodes, and the spring clip and the holding plate are connected to the ground of the drive circuit.

[Industrial application field]

The present invention relates to improving the electromagnetic shielding effect of flat display devices such as plasma display devices.

With the spread of digital electronic devices in recent years, there are many opportunities for electromagnetic waves emitted from electronic devices to adversely affect the operation of other electronic devices, and electronic devices are subject to EMI (EIelectro-M).
It is important to take measures against agnetic interference (electromagnetic environment compatibility).

Since flat display devices such as plasma displays and liquid crystal displays are thin and lightweight, they are increasingly being used as display devices useful for portable electronic devices, and there is increasing demand for the integrity of their electromagnetic shielding.

[Conventional technology]

Figure 3 is a diagram showing the main parts of a conventional flat display device, showing the state of connection of the connection cable to the display panel, where (a) is a cross-sectional view, and (b) is a view from the side opposite to the display surface. This is a back view.

A flat display device such as a plasma display or a liquid crystal display device usually has a large number of column electrodes 11/ and row electrodes 11.
A display panel 1 has a pair of glass substrates with drive electrodes such as /' formed on their inner surfaces facing each other across a gap, and a drive circuit 2 for driving the display panel 1 is mounted on the back surface thereof. It consists of an attached printed board.

Then, when a driving voltage is applied between a specific row electrode and a specific column electrode, a predetermined intersection point emits light or blocks light by gas discharge or liquid crystal display to perform display.

The drive electrodes 111 of the display panel 1 and the drive circuit 2 are connected to the terminal portions 111a of the plurality of electrodes 111 led out over almost the entire length of the periphery of the display panel 1, parallel to one side of the connection cable 3 made of a flexible printed board. A contact connection is made in a separable manner by pressing the conductor pattern 31 formed on the surface.

That is, the flexible printed board 3 on which the conductor patterns 31 are formed at the same pitch as the terminal portions 111a of the drive electrodes is
The conductor pattern 31 is positioned on the glass substrate 11 so as to face the terminal portion of the display panel, and a presser plate 42 made of a metal material and having high bending rigidity is mounted via a flexible member 41 such as rubber. , the conductor pattern 31 is held between spring clips 5 made of a spring plate material bent into a substantially U-shape.
is pressed against the terminal portion 111a of the drive electrode 111.

[Problem to be solved by the invention]

Since high-speed, high-voltage pulses of 50 to several tens of MH2 are constantly transmitted to the drive circuit and connection cables, if there is a conductor with a large surface area that is not grounded near the transmission path of these pulses, Electromagnetic waves are radiated due to the noise potential induced in the conductor, which may have an adverse effect on other devices and deteriorate the shielding effect against noise electromagnetic waves from the outside.

However, in the conventional flat display device with the above configuration,
It is difficult to electrically connect the spring clips and metal holding plates that sandwich the flexible printed board and the board to generate contact force to the ground potential of the drive circuit via the connection cable, and these relatively Since the conductive member having a large surface area is electrically floating from the ground, there is a problem in that the electromagnetic shielding effect is small.

The problem was that it was large.

The present invention was created in view of the above-mentioned problems, and an object of the present invention is to provide a flat display device with improved EMI countermeasures by connecting the spring clip and presser plate for generating contact force to the ground. .

[Means to solve the problem]

The above problem is that the connection cable made of a flexible printed board that connects the terminal portion of the drive electrode led out to the edge of the display panel to the drive circuit is pressed against the display panel by the spring clip through the holding plate and connected. In the display device, a ground electrode consisting of a ground pad connected to the holding plate and a ground terminal part connected to a connection cable is provided on the display panel, and the holding plate and the flexible printed board are connected via the ground electrode. This problem is solved by the flat display device of the present invention, characterized in that the spring clip and the holding plate are connected to a ground lead-out pattern to lead out the spring clip and the holding plate to the ground of the drive circuit.

[Effect]

Since the spring clip and presser plate, which used to be floating from the ground, are grounded, their potential is always at the ground level.
Noise potential is induced from high-speed, high-level pulse circuits in the vicinity of these circuits, and the magnetic shielding effect of the device is improved.

〔Example〕

The present invention will be explained in detail below with reference to the accompanying drawings.

FIG. 1 is an exploded perspective view showing the main parts of the flat display device of the present invention, and FIG. 2 is a sectional view showing the connecting portion.

In FIG. 1, reference numeral 6 denotes a display panel such as a plasma display panel or a liquid crystal panel similar to the conventional example, and a pair of glass substrates 61 and 62 each having a large number of drive electrodes 611 and 612 perpendicular to the inner surface formed thereon. It is placed opposite to.

These drive electrodes 611, 621 are led out to the outer peripheral edge of the opposing region to form a terminal portion 611a.

On both sides of the arrangement area of the terminal portion 611a, a ground electrode 612 is formed independently of the drive electrode 611, in which the ground terminal portion 612a adjacent to the terminal portion 611a and the outermost ground pad 612b having a large area are connected. ing.

7 is a connection cable, which connects to the terminal section 611 on the glass substrate 61.
A plurality of conductor patterns 71, 71 . . . . Earth lead-out patterns 72, 72 are formed in the outermost row, and one upper end is connected to a drive circuit mounted on a printed board (not shown).

Reference numeral 8 denotes a holding plate made of a metal with high bending strength, and has a length that is approximately equal to the entire width of the glass substrate 611 and covers the ground pads 612b at both ends, and is made of an elastic material such as rubber and has a length that is equal to the width W of the connection cable 30. It serves to uniformly press the connection cable 7 against the glass substrate 61 via the lower pressing member 82 having a lower pressing member 82 having

Reference numeral 5 denotes a spring clip, which is made of a spring plate material bent into a substantially U-shape, and is connected to a glass substrate 61, a connecting cable 7, and a presser clamp 8.
1 and then apply a pressing force.

Reference numeral 9 denotes a connecting member having a width equal to the width of the earth pad 612b, which is formed by bending a spring plate material into a U-shape, for example, and is interposed between both ends of the holding plate 81 and the earth pad 612b, and contacts both with a predetermined contact force. It looks like this.

The connection to the display panel in the flat display device constructed of the above-mentioned members is the same as in the conventional example with regard to drive electrodes. As shown in FIG. 2, the spring clip 5 and the holding plate 81 are connected to the glass substrate 6 via the contact member 9.
The ground electrode 812 is once connected to the ground pad 612b of the ground electrode 612 on the ground electrode 1, and the ground electrode 812 is further connected to the ground lead-out pattern 72 of the connection cable 7 at the position of the ground terminal portion 612a in the same way as the other drive electrodes. It is led out to the printed board of the drive circuit.

In place of the contact member 9 of the 0-shaped spring in this embodiment, an elastic rod wrapped in conductive foil may be interposed, or after being held between spring clips, both ends of the presser plate and the earth band are connected. It goes without saying that the same effect can be obtained even if the two are bonded with a conductive adhesive.

〔Effect of the invention〕

According to the present invention, a conductor such as a spring clip necessary for connecting a drive electrode of a display panel to a drive circuit can be connected to ground by a simple means, and an electromagnetic shield for a flat display device such as a plasma display can be connected to the ground. It has the effect of improving the effect.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view showing the main parts of the flat display device of the present invention, FIG. 2 is a sectional view showing the connecting portion, and FIG. 3 is a diagram showing the main parts of the conventional flat display device. In the figure, 1. 6-4-sided display panel, 5--spring clip, 61. 62-m-glass substrate, 61L621--drive electrode, 611a--one terminal section, 612-ground electrode, 6L2a--ground Pad, 612b-
Earth terminal section, 7-connection cable, 71-conductor pattern, 72-earth drawer pattern, 81-pressing plate, 82-...pressing member, 9-
A contact member. (Mu) The 1st punishment of Den Futoshi and Suiku Futou Otsu) 2nd picture of the bottle showing the general rule of Sumi's youngest concubine Whistle Kaf'r. haze

Claims (1)

[Claims] Drive electrodes (611
A connection cable (7) made of a flexible printed board that connects the terminal part (611a) of ) to the drive circuit is pressed and connected to the display panel (6) by the spring clip (5) via the holding plate (81). In the display device, a ground pad (612a) connected to the holding plate (81) is provided.
) and the ground terminal section (
A ground electrode (61) consisting of a A flat display device characterized in that the spring clip (5) and the presser plate (81) are connected to the ground of a drive circuit.