CN1304887C - Electrostatic discharge protection circuit - Google Patents

Abstract

The invention relates to an electrostatic discharge protection circuit which is suitable for being configured on a liquid crystal display panel. The liquid crystal panel has a plurality of data wirings parallel to each other and a plurality of scanning wirings vertical to the data wirings and parallel to each other. The ESD protection circuit is mainly composed of a plurality of ESD protection units, at least one grounding line and at least one serial line. The ESD protection units are disposed on the LCD panel, and each ESD protection unit is electrically connected to one of the scan lines or the data lines. The grounding circuit is electrically connected with the electrostatic discharge protection unit. At least one serial connection circuit in the panel is electrically connected with at least two electrostatic discharge protection units.

Description

Electrostatic discharge protection circuit

technical field

The invention relates to a circuit, in particular to an electrostatic discharge protection circuit (ELECTRO-STATIC DISCHARGEPROTECTION CIRCUIT) applied to a liquid crystal display (Liquid Crystal Display, LCD).

Background technique

The rapid progress of the multimedia society is mostly due to the rapid progress of semiconductor components or man-machine display devices. As far as the display is concerned, the cathode ray tube (Cathode Ray Tube, CRT) has been monopolizing the display market in recent years because of its excellent display quality and economy. However, for the environment where individuals operate most terminals/display devices on the table, or from the perspective of environmental protection, if the trend of energy saving is predicted, cathode ray tubes still have many problems in terms of space utilization and energy consumption, and There is no effective solution to the demands of lightness, thinness, shortness, smallness and low power consumption. Therefore, liquid crystal displays with superior characteristics such as high image quality, increased space utilization efficiency, low power consumption, and no radiation have gradually become the mainstream of the market.

A general liquid crystal display is mainly composed of a liquid crystal display panel (LCD panel) and a backlight module (back light module), and the liquid crystal display panel is formed by a semiconductor process (semiconductor process) to form a lot of scan lines (scan lines) ), data wiring (data line), thin film transistor (Thin Film Transistor, TFT)... and other non-fine circuits and components. During the manufacturing process of the liquid crystal display panel, whether it is the manufacturing equipment, the operator, or the liquid crystal display panel itself, many electrostatic charges may be accumulated. Therefore, when the liquid crystal display panel is in contact with manufacturing equipment, operators or other objects during the manufacturing process, it is very likely to cause electrostatic discharge. Since the circuits and components on the liquid crystal display are very delicate, as long as there is a slight electrostatic discharge, it is easy to cause the consequence that the entire liquid crystal display panel needs to be scrapped. In order to solve the problem of the low yield rate of the liquid crystal display panel caused by the electrostatic discharge phenomenon, it is generally solved by designing an electrostatic discharge protection circuit on the liquid crystal display panel.

Please refer to FIG. 1A and FIG. 1B , which are circuit diagrams of two operating states of a conventional ESD protection unit. Please refer to FIG. 1A and FIG. 1B , the conventional electrostatic discharge protection unit 100 is mainly composed of eight diodes (diodes) D1-D8, and is electrically connected to one of the liquid crystal display panels (not shown). Data wiring DL10. When the static charge enters from the data wiring DL10 in FIG. 1A, the forward biased static charge can be transferred to a ground through four paths: diode D4→D8, diode D4→D7, diode D3→D8, and diode D3→D7. Line GND10, and use this to quickly discharge the static charge. When the static charge enters from the data line DL10 in FIG. 1B , the reverse biased static charge can be quickly released through the path of the diode D5→D2.

However, in the above-mentioned prior known ESD protection unit 100, when the charge amount of the instantaneous electrostatic discharge exceeds its load, the static charge will still enter a display element array area A10 through the data wiring DL10, and cause the display element Damage to components such as thin film transistors in the array area A10.

It can be seen that the above-mentioned existing electrostatic discharge protection circuit obviously still has inconveniences and defects in structure and use, and needs to be further improved urgently. In order to solve the problems existing in the ESD protection circuit, the relevant manufacturers have tried their best to find a solution, but no suitable design has been developed for a long time, and the general products do not have a suitable structure to solve the above problems. Obviously, it is a problem that relevant industry players are eager to solve.

In view of the defects existing in the above-mentioned existing electrostatic discharge protection circuit, the inventor actively researches and innovates based on years of rich practical experience and professional knowledge engaged in the design and manufacture of this type of product, and cooperates with the application of academic theory, in order to create a new type of structure The electrostatic discharge protection circuit can improve the general existing electrostatic discharge protection circuit and make it more practical. Through continuous research, design, and after repeated trial samples and improvements, the present invention with practical value is finally created.

Contents of the invention

The purpose of the present invention is to overcome the defects existing in the existing electrostatic discharge protection circuit and provide a new electrostatic discharge protection circuit. practical.

Compared with the prior art, the present invention has obvious advantages and beneficial effects. It can be seen from the above technical solutions that, in order to achieve the aforementioned object of the invention, the present invention provides an electrostatic discharge protection circuit, which is suitable for being configured on a liquid crystal display panel. The liquid crystal panel has multiple first wirings parallel to each other. The electrostatic discharge protection circuit is mainly composed of a plurality of first electrostatic discharge protection units, at least one grounding line and at least one first series connection line. The first electrostatic discharge protection units are configured on the liquid crystal display panel, and each first electrostatic discharge protection unit is electrically connected to a first wiring. The grounding line is electrically connected to the aforementioned first ESD protection unit. The first series connection is electrically connected with at least two first ESD protection units.

In this ESD protection circuit, the liquid crystal panel also has a plurality of second wires parallel to each other, and these second wires are perpendicular to the first wires, and the ESD protection circuit further includes a plurality of second ESD wires, for example. A discharge protection unit and at least one second serial connection. The second electrostatic discharge protection units are configured on the liquid crystal display panel, and each second electrostatic discharge protection unit is electrically connected to a second wire, for example. For example, the grounding line is also electrically connected to the second ESD protection units. The second series connection is, for example, electrically connected to at least two second ESD protection units.

In addition, the second series connection is, for example, electrically connected to all the second ESD protection units. Alternatively, the second series circuit includes a plurality of circuit patterns, and the liquid crystal panel also has a plurality of second driving chips, and each circuit pattern is electrically connected to a part of the second wiring controlled by a second driving chip.

In addition, each second ESD protection unit includes, for example, a plurality of diodes electrically connected to each other.

Furthermore, the first wiring is, for example, a data wiring, and the second wiring is, for example, a scanning wiring.

Certainly, the above-mentioned first wiring may also be a data wiring or a scanning wiring.

Furthermore, the first series connection is, for example, electrically connected to all the first ESD protection units. Alternatively, the first series circuit includes a plurality of circuit patterns, and the liquid crystal panel also has a plurality of first driving chips, and each circuit pattern is electrically connected to a part of the first wiring controlled by a first driving chip.

In addition, each first ESD protection unit includes, for example, a plurality of diodes electrically connected to each other.

From the above, it can be known that the present invention relates to an electrostatic discharge protection circuit, which is suitable for being configured on a liquid crystal display panel. The liquid crystal panel has a plurality of parallel data lines and a plurality of vertical data lines and a plurality of scan lines parallel to each other. This electrostatic discharge protection circuit is mainly composed of a plurality of electrostatic discharge protection units, at least one grounding line and at least one series connection line. These electrostatic discharge protection units are arranged on the liquid crystal display panel, and each electrostatic discharge protection unit is electrically connected with a scanning wiring or a data wiring. The grounding line is electrically connected to the aforementioned ESD protection unit. At least one serial connection in the panel is electrically connected to at least two electrostatic discharge protection units.

With the above technical solution, the electrostatic discharge protection circuit of the present invention has at least the following advantages:

Since the electrostatic discharge protection circuit of the present invention is electrically connected to a plurality of electrostatic discharge protection units by using at least one series connection line, it can quickly disperse the electrostatic charge to a plurality of electrostatic discharge protection units during electrostatic discharge, thereby reducing the impact of electrostatic discharge on the liquid crystal display. The damage that the panel may cause, and at the same time improve the product yield of the liquid crystal display panel.

To sum up, the electrostatic discharge protection circuit with the special structure of the present invention improves the quality rate of the liquid crystal display. It has the above-mentioned many advantages and practical value, and there is no similar structural design publicly published or used in similar products, so it is indeed innovative. It has great improvements in both structure and function. It has made great progress, and has produced easy-to-use and practical effects, and has improved multiple functions compared with the existing electrostatic discharge protection circuit, so it is more suitable for practical use, and has wide application value in the industry. It is a novel, Progressive, practical new design.

The above description is only an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention, it can be implemented according to the contents of the description, and in order to make the above and other purposes, features and advantages of the present invention more obvious and understandable , a number of preferred embodiments are enumerated below, together with the accompanying drawings, which are described in detail as follows.

Description of drawings

1A and 1B are circuit diagrams of two operating states of a conventional ESD protection unit.

FIG. 2 is a schematic diagram of the electrostatic discharge protection circuit of the present invention configured on a liquid crystal display panel.

3A and 3B are circuit diagrams of two operating states of the ESD protection circuit according to an embodiment of the present invention.

4A-4C are schematic diagrams of the connection modes of the three serial lines in the electrostatic discharge protection circuit of the present invention.

5A and 5B are circuit diagrams of two operating states of an electrostatic discharge protection circuit according to another embodiment of the present invention.

100: Electrostatic discharge protection unit DL10: Data wiring

GND10: Grounding line A10: Display component array area

50: Liquid crystal display panel ESD, 200, 300: Electrostatic discharge protection circuit

210, 310: Electrostatic discharge protection unit 230, 330: Grounding line

240, 340: serial connection line A20: display component array area

A22: Pixel area D1～D14: Diodes

DL20: data wiring GL20: scanning wiring

Detailed ways

In order to further explain the technical means and effects that the present invention adopts to achieve the intended purpose of the invention, the specific implementation, structure, characteristics and effects of the electrostatic discharge protection circuit proposed according to the present invention will be described below in conjunction with the accompanying drawings and preferred embodiments. , as detailed below.

Please refer to FIG. 2 , which is a schematic diagram of the electrostatic discharge protection circuit of the present invention disposed on a liquid crystal display panel. Please refer to FIG. 2 , a liquid crystal display panel 50 has a plurality of data lines DL20 parallel to each other and a plurality of scan lines GL20 parallel to each other, wherein the scan lines GL20 are perpendicular to the data lines DL20 . In addition, the data wiring DL20 and the scanning wiring GL20 divide a display element array area A20 on the liquid crystal display panel 50 into a plurality of pixel regions (pixel regions) A22. An active component (not shown in the figure), such as a thin film transistor or other active components, is disposed in each pixel area A22. The electrostatic discharge protection circuit ESD of the present invention is suitable to be disposed beside the display element array area A20 , which is only briefly shown in FIG. 2 .

Please refer to FIG. 3A and FIG. 3B , which are circuit diagrams of two operating states of the electrostatic discharge protection circuit according to an embodiment of the present invention, and FIGS. 4A to 4C are three serially connected circuits in the electrostatic discharge protection circuit of the present invention. A schematic diagram of the connection method.

Please refer to FIG. 3A and FIG. 3B , the ESD protection circuit 200 of this embodiment is mainly composed of a plurality of ESD protection units 210 , a grounding line 230 and at least one serial connection 240 . Each ESD protection unit 210 is electrically connected to a data line DL20. For example, the ESD protection unit 210 is electrically connected to the data line DL20 in a one-to-one manner. The grounding line 230 is electrically connected to each ESD protection unit 210 . In addition, at least two ESD protection units 210 are electrically connected by the series connection 240 , and the ESD protection units 210 electrically connected by the series connection 240 are preferably adjacent to each other, as shown in FIG. 4A .

Of course, as shown in FIG. 4C , the series connection 240 may also be electrically connected to all the ESD protection units 210 . Alternatively, the ESD protection circuit 200 includes a plurality of serial lines 240, and each serial line 240 is electrically connected to a data wiring DL20 controlled by a data driver chip (not shown in the figure). In other words, the ESD protection unit 210 connected to each series connection line 240 corresponds to the data wiring DL20 controlled by the same data driver chip on the liquid crystal panel, as shown in FIG. 4B .

Please continue to refer to FIG. 3A , each ESD protection unit 210 is composed of, for example, eight diodes D1 - D8 . Among them, the diodes D3, D4, D7 and D8 are forward diodes for the electrostatic charges entering from the data wiring DL20 in FIG. Static charge that enters the data line DL20 and has a forward bias is a reverse diode. In other words, the electrostatic charge entering from the data line DL20 in FIG. 3A and having a forward bias can pass through the diodes D3, D4, D7 and D8.

What is important is that in this embodiment, several adjacent ESD protection units 210 have been electrically connected to each other by a serial connection 240 . Therefore, the electrostatic charges entering from any data wiring DL20 in FIG. The diodes D7 and D8 of the ESD protection unit 210 are led out, and then released to the outside through the grounding line 230 . Please refer to FIG. 3B , similarly, the static charge with reverse bias can also increase the static discharge path through the function of the series connection 240 . In other words, each time an electrostatic discharge phenomenon occurs, the electrostatic discharge protection circuit 200 of the present embodiment provides many times more static electricity discharge paths than the prior art. Thereby, a better protection effect can be provided for the liquid crystal display panel adopting the electrostatic discharge protection circuit 200 of this embodiment.

Please refer to FIG. 5A and FIG. 5B , which are circuit diagrams of two operating states of an electrostatic discharge protection circuit according to another embodiment of the present invention. Please refer to FIG. 5A, the electrostatic discharge protection circuit 300 of this embodiment is the same as the electrostatic discharge protection circuit 200 of the previous embodiment, and is composed of a plurality of electrostatic discharge protection units 310, a grounding line 330 and at least one series connection line 340 . Wherein, only the ESD protection unit 310 is different from the previous embodiment, and the rest of the components and the connection method of each component are the same as the previous embodiment, and the description thereof will be omitted here.

Each ESD protection unit 310 is composed of, for example, six diodes D9 - D14 . Among them, the diodes D12 and D14 are forward diodes for the electrostatic charge entering from the data wiring DL20 in FIG. For static charges that enter and have a forward bias, it is a reverse diode. In other words, the electrostatic charges entering from the data line DL20 in FIG. 5A and having a forward bias can pass through the diodes D12 and D14.

In this embodiment, the adjacent ESD protection units 310 are electrically connected to each other by a serial connection 340 . Therefore, after passing through the diode D12 of an ESD protection unit 310, the static charge entering from any data line DL20 in FIG. The diode D14 of the protection unit 310 is led out, and then released to the outside through the grounding line 330 . Please refer to FIG. 5B , similarly, the electrostatic charge with reverse bias can also increase the electrostatic discharge path through the function of the series connection 340 . In other words, every time an electrostatic discharge occurs, the electrostatic discharge protection circuit 300 of this embodiment is the same as the previous embodiment, and it provides many times more electrostatic discharge paths than the conventional technology.

It is worth noting that although the ESD protection unit is electrically connected to the data wiring in the above two embodiments as an example, the ESD protection circuit of the present invention can also electrically connect the ESD protection unit to the scanning wiring. The purpose of strengthening the electrostatic discharge protection of the liquid crystal display panel is achieved by electrically connecting the serial lines of the electrostatic discharge protection units. At the same time, the electrostatic discharge protection circuit of the present invention can of course also electrically connect its electrostatic discharge protection unit to the scanning wiring and the data wiring, and discharge static electricity through the grounding line. In addition, in the electrostatic discharge protection circuit of the present invention, the form of the electrostatic discharge protection unit is not limited to the above two embodiments. The main spirit of the present invention is to connect the ESD protection units with serial lines, thereby enhancing the protection ability of the ESD protection circuit against static electricity.

The above description is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. Anyone familiar with this field Those skilled in the art, without departing from the scope of the technical solution of the present invention, can use the technical content disclosed above to make some changes or modify equivalent embodiments with equivalent changes, but all the content that does not depart from the technical solution of the present invention, according to the present invention Any simple modifications, equivalent changes and modifications made to the above embodiments by the technical essence still belong to the scope of the technical solution of the present invention.

Claims (10)

1. An electrostatic discharge protection circuit, which is suitable for being configured on a liquid crystal display panel, wherein the liquid crystal panel has a plurality of first wirings parallel to each other, and is characterized in that the electrostatic discharge protection circuit comprises: A plurality of first electrostatic discharge protection units are disposed on the liquid crystal display panel, wherein each of the first electrostatic discharge protection units is electrically connected to one of the first wirings; At least one grounding line is electrically connected to the first ESD protection units; and At least one first serial connection is electrically connected to at least two of the first ESD protection units. 2. The electrostatic discharge protection circuit according to claim 1, wherein the liquid crystal panel has a plurality of second wirings parallel to each other, and the second wirings are perpendicular to the first wirings, The ESD protection circuit further includes: A plurality of second electrostatic discharge protection units are arranged on the liquid crystal display panel, wherein each of the second electrostatic discharge protection units is electrically connected to one of the second wirings, and the grounding line is connected to the the second ESD protection unit is electrically connected; and At least one second series connection is electrically connected to at least two of the second ESD protection units. 3. The ESD protection circuit according to claim 2, wherein the second series connection is electrically connected to all the second ESD protection units. 4. The electrostatic discharge protection circuit according to claim 2, wherein the second series circuit includes a plurality of circuit patterns, and the liquid crystal panel has a plurality of second driving chips, and each of the circuit patterns It is electrically connected with the part of the second wires controlled by one of the second driving chips. 5. The ESD protection circuit according to claim 2, wherein each of the second ESD protection units comprises a plurality of diodes electrically connected to each other. 6. The electrostatic discharge protection circuit according to claim 2, wherein the first wirings include data wirings, and the second wirings include scanning wirings. 7. The ESD protection circuit according to claim 1, wherein the first wirings include data wirings or scanning wirings. 8. The ESD protection circuit according to claim 1, wherein the first series connection is electrically connected to all the first ESD protection units. 9. The electrostatic discharge protection circuit according to claim 1, wherein the first series circuit includes a plurality of circuit patterns, and the liquid crystal panel has a plurality of first driving chips, and each of the circuit patterns It is electrically connected with the first wires controlled by one of the first driving chips. 10. The ESD protection circuit according to claim 1, wherein each of the first ESD protection units comprises a plurality of diodes electrically connected to each other.

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