JP2003091265A - Scanning signal driving device and picture display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To protect a circuit inside of a gate driver from static electricity applied to the gate driver from the surface part thereof. SOLUTION: The picture display device comprises a gate driving voltage output circuit 2 and a line-sequential operation control circuit 3 for outputting scanning signals to a picture display part 12, a voltage generation circuit 23 for applying a driving voltage to the scanning signals and a control signal voltage for performing scanning control, gate driving voltage wiring 4 for transmitting the driving voltage, a gate driving voltage reference potential wiring 5 for applying a reference potential to the driving voltage, a logic voltage reference potential wiring 7 for keeping a potential lower than the reference potential of the driving voltage, and a switching element 8 arranged across the gate driving voltage reference potential wiring 5 and the logic voltage reference potential wiring 7, and brings the gate driving voltage reference potential wiring 5 into conduction with the logic voltage reference potential wiring 7 when the reference voltage of the driving voltage is not applied to the gate driving voltage reference potential wiring 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device for displaying an image such as liquid crystal.

[0002]

2. Description of the Related Art Generally, an image liquid crystal display device such as a liquid crystal device comprises a source driver for controlling display image data and a gate driver for controlling line-sequential scanning. The gate driver controls a voltage for driving the liquid crystal display device. And a logic signal low voltage system for controlling line-sequential scanning.

The above gate driver will be described below as an example of the related art with reference to the drawings.

FIG. 5 is a block diagram showing the structure of a conventional gate driver. FIG. 6 is a block diagram of a liquid crystal display device using a gate driver in a conventional example. FIG. 7 is a block diagram showing a flow of static electricity when static electricity is applied to the gate driver in the conventional example.

In FIG. 5, reference numeral 51 designates a gate driver and 5
2 is a gate drive voltage output circuit of the gate driver 51, 5
3 is a line-sequential scanning control circuit for controlling the line-sequential scanning of the gate drive voltage output circuit 52, 54 is a gate drive voltage input to the gate drive voltage output circuit 52 for driving the liquid crystal display device, and 55 is a liquid crystal display device. Gate drive voltage 51 input to the gate drive voltage output circuit 52 for driving the
Gate drive voltage reference potential, 56 is a logic voltage input to the line-sequential scanning control circuit 53, and 57 is a logic voltage 5
6 is a logic voltage reference potential, and 58 is a logic signal input to the line-sequential scanning control circuit 53.

In FIG. 6, 60 is an image display unit, and 61 is an image display unit 6 connected to a gate drive voltage output circuit 52.
0 is a gate electrode, 62 is a gate drive pulse output from the gate drive voltage output circuit 52 to the gate electrode 61, 63
Is a gate drive voltage 54, a gate drive voltage reference potential 55,
A voltage generation circuit that generates a logic voltage 56 and a logic voltage reference potential 57, 64 is a source driver that controls a display image on the image display unit 60, 65 is image data for displaying an image on the image display unit 60, and 66 is a source Driver 6
4 is a source electrode of the image display unit 60 connected to the image display device 4, 67 is an image voltage output from the source driver 64 according to the image data 65, 58 is a logic signal for controlling the gate driver 51 and the source driver 64, and 68 is a logic signal 5
8 is a control signal generating circuit, and 69 is the image display unit 6.
0, a gate driver 51, and a source driver 64. Here, the numbers of FIG. 5 are used as they are for the other components.

In FIG. 7, 70 is a gate driver 51.
3 is an arrow showing a path through which static electricity applied from the outside is discharged. Here, the other components use the numbers in FIGS. 5 and 6 as they are.

The liquid crystal display device having the above structure will be described with reference to FIG.

The image display section 60 of the liquid crystal display device 69 has a gate drive pulse 62 output from the gate driver 51.
Then, the image is displayed by the image voltage 67 output from the source driver 64. Among them, the gate driver 51
Is the gate drive voltage 5 output from the voltage generation circuit 63.
4 and the gate drive voltage reference potential 55 are output to the gate electrode 61 as a gate drive pulse 62 by the gate drive voltage output circuit 52 controlled by the line sequential scan control circuit 53, and line sequential scanning is performed.

The line-sequential scanning control circuit 53 is controlled by the logic signal 58 output from the control signal generator 68, and operates by the voltage of the logic voltage 56 and the logic voltage reference potential 57. Generally, the logic voltage reference potential 57
Is used at the ground level, which serves as the reference potential of the liquid crystal display device.

The conventional gate driver 51 operates as described above. In general, the surface portion of the gate driver 51 is electrically connected to the voltage generation circuit 63 at the connection point 59, and has a gate drive voltage reference potential 55 for manufacturing reasons.

[0012]

However, in the gate driver having such a structure, when static electricity is applied to the surface portion of the gate driver 51, the static electricity is transmitted from the surface portion of the gate driver 51 via the connection point 59. The gate driver 51 enters the gate driver 51 and outputs the gate drive voltage output circuit 52.
And the line-sequential scanning control circuit 52 and the like are discharged to a logic voltage reference potential (liquid crystal display reference potential) which is generally connected to the ground. At this time, the gate drive voltage output circuit 52 and the line-sequential scanning control circuit 5 are caused by static electricity.
2 is likely to be destroyed.

The present invention solves the above-mentioned conventional problems. An element for discharging static electricity is provided inside or outside the gate driver so that the static electricity applied to the gate driver does not pass through the circuit in the gate driver. The purpose is to discharge and protect the circuits in the gate driver.

[0014]

In order to achieve the above-mentioned object, a first aspect of the present invention (corresponding to claim 1) is an image display device for displaying an image on an image display section by a scanning signal and an image signal. In the scanning signal drive device for supplying the scanning signal, a scanning signal output unit for outputting the scanning signal to the image display unit, a housing unit for housing the scanning signal output unit, and the scanning signal output unit. And a voltage supply means for providing a drive voltage of the scan signal and a voltage of a control signal for performing scan control, and transmitting the drive voltage provided between the voltage supply means and the scan signal output means. A drive voltage wiring, a drive voltage reference potential wiring that gives a reference potential of the drive voltage, a low potential wiring that maintains a potential lower than the drive voltage reference potential, the drive voltage reference potential wiring, and the low potential wiring And a switch means provided between the drive voltage wiring and the low potential wiring to control conduction between the low potential wiring and the casing, and the casing section is electrically connected to the drive voltage reference potential wiring to provide a reference potential of the drive voltage. Is kept at the same potential,
The switch means is a scanning signal driving device and a scanning signal driving device for electrically connecting the driving voltage reference potential wiring and the low potential wiring when a reference voltage of the driving voltage is not applied to the driving voltage reference potential wiring. is there.

A second aspect of the present invention (corresponding to claim 2)
The scanning signal output means has a voltage output circuit that outputs a voltage that becomes a scanning signal to the image display unit, and a scanning control circuit that receives the control signal from the outside and controls the voltage output circuit. 2. The scanning signal drive device according to claim 1, wherein the drive voltage wiring and the drive voltage reference potential are connected to the drive voltage output circuit, and the low potential wiring is connected to the scan control circuit. Is a scanning signal driving device of the present invention.

In the third aspect of the present invention, the low potential wiring keeps the potential at a reference potential of the image display device.
Is a scanning signal driving device of the present invention.

A fourth invention (corresponding to claim 4)
Is the scanning signal drive device according to the first aspect of the present invention, in which the low potential wiring keeps the potential at the ground level.

The fifth invention (corresponding to claim 5)
Is the scanning signal drive device according to the first or second aspect of the present invention, wherein the switch means is provided inside or inside the casing.

A sixth aspect of the present invention (corresponding to claim 6)
Receives the scanning signal input from the scanning signal driving device of the first aspect of the present invention, the image signal driving device that gives an image signal, the scanning signal driving device, and the image signal input from the image signal driving device. An image display device that includes an image display unit that receives and displays an image.

The seventh invention (corresponding to claim 7)
Is the image display device according to the fifth aspect of the present invention, wherein the image display unit has a liquid crystal display panel.

In the present invention as described above, for example, a switching element is provided inside or outside the gate driver,
By discharging static electricity to a logic voltage reference potential (liquid crystal display reference potential) through a switching element, the purpose is to protect the gate drive voltage output circuit and line-sequential scanning control circuit inside the gate driver, and to improve resistance to static electricity. To do.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the structure of a gate driver according to an embodiment of the present invention.

FIG. 2 is a block diagram of a liquid crystal display device using the gate driver according to the embodiment of the present invention.

FIG. 3 is a block diagram showing a flow of static electricity when static electricity is applied to the gate driver according to the embodiment of the present invention.

In FIG. 1, 1 is a gate driver, 2 is a gate drive voltage output circuit of the gate driver 1, 3 is a line sequential scanning control circuit for controlling line sequential scanning of the gate drive voltage output circuit 2, and 4 is a liquid crystal display device. The gate drive voltage wiring 5 for supplying the gate drive voltage input to the gate drive voltage output circuit 2 to drive the liquid crystal display device is input to the gate drive voltage output circuit 2 to drive the liquid crystal display device, and the surface of the gate driver 1 is driven. A substrate 1 for housing a gate voltage drive output circuit 2 and a line sequential operation control circuit 3
a gate drive voltage reference potential wiring for providing a gate drive voltage reference potential of the gate drive voltage 4 which is electrically the same potential as a
6 is a logic voltage wiring for supplying a logic voltage to be input to the control circuit 3, 7 is a logic voltage reference potential wiring for supplying a logic voltage reference potential of the logic voltage, 8 is a gate drive voltage reference potential wiring 5 and a logic voltage reference potential wiring 7. A switching element provided between and is a logic signal wiring 9 for giving a logic signal input to the line-sequential scanning control circuit 3.

In FIG. 2, 20 is an image display unit having a liquid crystal display panel, 21 is a gate electrode of the image display unit 20 connected to the gate drive voltage output circuit 2, 22 is a gate electrode 21 from the gate drive voltage output circuit 2. The output gate drive pulse, 23 is applied to the gate drive voltage wiring 4, the gate drive voltage reference potential wiring 5, the logic voltage wiring 6, and the logic voltage reference potential wiring 7, respectively, the gate drive voltage, the gate drive voltage reference potential, the logic voltage, A voltage generation circuit that supplies a logic voltage reference potential, 24 is a source driver that controls a display image of the image display unit 20, 25 is image data for displaying an image on the image display unit 20, and 26 is connected to the source driver 24. The source electrode of the image display unit 20, 27 is a source driver 24 according to the image data 25.
The image voltage output from the device, 8 is a logic signal that controls the gate driver 1 and the source driver 24, 28 is a control signal generation circuit that generates the logic signal 9, 29 is an image display unit 20, the gate driver 1, and the source driver 24 It is a liquid crystal display device.

Further, the gate drive voltage reference potential wiring 5 for connecting the voltage generation circuit 23 and the gate drive voltage output circuit 2 to each other.
By electrically connecting at a connection point 59 on the substrate 1a, the gate drive voltage reference potential of the substrate 1a is maintained.

Here, the numbers in FIG. 1 are used as they are for the other components.

Reference numeral 30 in FIG. 3 is an arrow showing a path through which static electricity externally applied to the gate driver 1 is discharged. Here, for the other components, the numbers in FIGS. 1 and 2 are used as they are.

The liquid crystal display device according to the present embodiment having the above structure will be described with reference to FIG.

The image display section 20 of the liquid crystal display device 29 has a gate drive pulse 22 output from the gate driver 1.
And an image voltage 27 output from the source driver 24 displays an image. Among them, the gate driver 1
The gate drive voltage output from the voltage generation circuit 23 through the gate drive voltage wiring 4 and the gate drive voltage reference potential output through the gate drive voltage reference potential wiring 5 are controlled by the line-sequential scan control circuit 3. The drive voltage output circuit 2 outputs the gate drive pulse 22 to the gate electrode 21 to perform line-sequential scanning.

The line-sequential scanning control circuit 3 is controlled by the logic signal output from the control signal generator 28 via the logic signal wiring 9, and is determined by the logic voltage and the logic voltage group forward potential wiring 7. It operates with the voltage of the reference potential. However, in general, the logic voltage reference potential is at the ground level and becomes the reference potential of the entire liquid crystal display device.

On the other hand, the switching element 8 is provided between the gate drive voltage reference potential wiring 5 and the logic voltage reference potential wiring 7, and is turned on when the gate drive voltage is not applied to the gate drive voltage wiring 4. The gate drive voltage reference potential wiring 5 and the logic voltage reference potential wiring 7 are connected with low resistance. Also, when the gate drive voltage 4 is applied, the switching element 8 is turned off, and the gate drive voltage reference potential 5 wiring and the logic voltage reference potential wiring 7 are opened.

In the gate driver 1 having such a structure,
When static electricity 30 is applied to the vicinity of the gate driver 1 while the gate driver 1 is not operating, the static electricity 30 is transferred from the substrate 1 a of the gate driver 1 to the connection point 10
Through the gate driver reference potential wiring 5.
At this time, since the gate drive voltage is not applied to the gate drive voltage wiring 4, the switching element 8 is turned on, and the static electricity 30 passes through the logic voltage reference potential wiring 7 via the turned on switching element 8. Discharged to ground.

On the other hand, since the switching element 8 is turned off while the gate driver 1 is operating, the voltage generating circuit 23 applies the gate drive voltage from the gate drive voltage wiring 4 to the gate drive voltage output circuit. .

As described above, in the present embodiment, the static electricity applied to the substrate 1a of the gate driver 1 is discharged from the logic voltage reference potential to the ground via the switching element 8, so that the gate drive voltage is reduced. It does not go through the output circuit 2 or the line-sequential scanning control circuit 3.
Therefore, the gate drive voltage output circuit 2 and the line sequential scanning control circuit 3 can be protected from static electricity.

Next, FIG. 4 shows another configuration example of the liquid crystal display device of the present embodiment. As shown in the figure, in the liquid crystal display device of this example, the switching element 8 for discharging is not disposed inside the substrate 1a of the gate driver 1 but in the display panel 2
Since it is provided on the display device 9, the same operation and effect as the embodiment shown in FIG. 1 can be basically obtained.

In the above embodiment, the gate driver 1 corresponds to the scanning signal drive device of the present invention, and the gate drive electrode output circuit 2 and the line sequential operation control circuit 3 are provided.
Corresponds to the scanning signal output means of the present invention, the substrate 1a corresponds to the casing of the present invention, the signal generating circuit 28 corresponds to the control signal supplying means of the present invention, and the voltage generating circuit 23.
Corresponds to the voltage supply means of the present invention, the gate drive voltage wiring 4 corresponds to the drive voltage wiring of the present invention, the logic voltage reference potential wiring 7 corresponds to the low potential wiring of the present invention, and the switching element 8 Corresponds to the switch means of the present invention, the source driver 24 corresponds to the image signal driving device of the present invention, and the image display section 20 corresponds to the image display section of the present invention.

The gate drive voltage output circuit 2 corresponds to the drive voltage output circuit of the present invention, and the line sequential operation control circuit 3 corresponds to the operation control circuit of the present invention.

The gate drive voltage corresponds to the drive voltage of the scanning signal of the present invention, the logic voltage corresponds to the voltage of the control signal of the present invention, and the logic signal corresponds to the control signal of the present invention.

However, the present invention is not limited to the above embodiment, and the switching means of the present invention may be a switch using FET as the switching element 8 or an analog switch using a thin film transistor or the like. Good. A mechanical switch may be used instead of the switching element. Further, the operation control circuit of the present invention,
Instead of line-sequential scanning, dot-sequential scanning may be performed. Although the logic voltage reference potential has been described as being at the ground level, the potential maintained by the low potential wiring of the present invention may be a voltage value lower than the gate drive voltage reference potential. Therefore, it does not have to be the ground level, does not have to be the reference potential of the image display device, and may have any size.

Further, in the gate driver 1, the gate drive voltage output means 2 and the line-sequential scanning control means 3 operate by receiving voltage and signal inputs from the signal generating circuit 23 and the signal generating circuit 28, respectively. However, in the scanning signal output means of the present invention, the drive voltage output circuit and the operation control circuit are
It may have an integrated configuration.

Although the image display section 20 has a liquid crystal display panel, it may have a display panel such as a plasma display or an EL display.

[0045]

As described above, according to the present invention, the circuit in the scanning signal driving device can be protected from static electricity.

[Brief description of drawings]

FIG. 1 is a block diagram of a gate driver according to an embodiment of the present invention.

FIG. 2 is a block diagram of a liquid crystal display device using a gate driver according to an embodiment of the present invention.

FIG. 3 is a diagram showing a discharge path of static electricity when static electricity is applied to the gate driver in the embodiment of the present invention.

FIG. 4 is a block diagram showing another configuration example of the gate driver in the embodiment of the present invention.

FIG. 5 is a block diagram of a conventional gate driver.

FIG. 6 is a block diagram of a liquid crystal display device using a conventional gate driver.

FIG. 7 is a diagram showing a discharge path of static electricity when static electricity is applied to a conventional gate driver.

[Explanation of symbols]

1 gate driver 1a Substrate 2 Gate drive voltage output circuit 3-line sequential scanning control circuit 5 Gate drive voltage reference potential wiring 7 Logic voltage reference potential wiring 8 switching elements

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H04N 5/66 102 H04N 5/66 102B F term (reference) 2H093 NA16 NC03 NC34 NC58 NC59 ND40 NE07 5C006 AC02 BB12 BC03 BC11 BC22 BC23 BF42 FA31 FA33 5C058 AA06 BA01 BA30 BA33 5C080 AA10 BB05 DD19 FF12 JJ02

Claims (7)

[Claims] 1. An image display device for displaying an image on an image display unit by a scanning signal and an image signal, wherein the scanning signal drive unit applies the scanning signal, and the scanning unit outputs the scanning signal to the image display unit. A signal output unit, a housing unit accommodating the scanning signal output unit, a voltage supply unit for supplying the scanning signal output unit with a driving voltage of the scanning signal and a voltage of a control signal for performing scanning control, Lower than the drive voltage wiring for transmitting the drive voltage, the drive voltage reference potential wiring for giving the reference potential of the drive voltage, and the drive voltage reference potential wiring provided between the voltage supply means and the scanning signal output means. A low-potential wiring that maintains a potential, and a switch that is provided between the drive-voltage reference potential wiring and the low-potential wiring and controls conduction between the drive-voltage wiring and the low-potential wiring. And a stage, the casing is in conduction with the drive voltage reference potential wiring,
The switch means is kept at the same potential as the reference potential of the drive voltage, and the switch means is configured to connect the drive voltage reference potential wiring and the low voltage when the reference voltage of the drive voltage is not applied to the drive voltage reference potential wiring. A scanning signal driving device for electrically connecting to a potential wiring. 2. The scanning signal output means includes a voltage output circuit for outputting a voltage as a scanning signal to the image display unit, and a scanning control circuit for receiving the control signal from the outside and controlling the voltage output circuit. The scan signal drive according to claim 1, wherein the drive voltage line and the drive voltage reference potential are connected to the drive voltage output circuit, and the low potential line is connected to the scan control circuit. apparatus. 3. The scanning signal driving device according to claim 1, wherein the low potential wiring keeps the potential at a reference potential of the image display device. 4. The scanning signal drive device according to claim 1, wherein the low potential wiring keeps the potential at a ground level. 5. The scanning signal drive device according to claim 1, wherein the switch means is provided inside or inside the housing portion. 6. A scanning signal driving device according to claim 1, an image signal driving device for giving an image signal, and a receiving of the scanning signal from the scanning signal driving device,
An image display device comprising: an image display unit that receives an image signal from the image signal driving device and displays an image. 7. The image display device according to claim 4, wherein the image display unit has a liquid crystal display panel.