KR20020018261A - Driving method of an active matrix display apparatus - Google Patents

Abstract

PURPOSE: A method for driving active matrix display device is provided to accurately apply data only to a pertinent scan line by applying a selective signal to a scan line and then to a data line. CONSTITUTION: Switching elements and display devices are provided between each of a plurality of scan lines and a plurality of data lines aligned in a matrix form. A selective signal for driving the scan lines is generated by a scan line driving circuit(22) to turn on the switching elements connected with the scan lines. The selective signal is enabled to apply data corresponding to the scan lines to the data lines after delaying a predetermined time by a data driving circuit(20). These two processes are carried out to the scan lines. The delay is accomplished by a delay circuit for controlling a data latch time of the data driving circuit and for delaying an output line of the data driving circuit by the predetermined time.

Description

Driving method of an active matrix display apparatus

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving method of a display device, and more particularly, to an active matrix display device having a non-light emitting element such as a liquid crystal display element arranged in a matrix form or a light emitting element such as an EL element and sequentially driven by a switching element. It relates to a driving method of.

In the structure of a conventional active matrix display device, scan lines arranged in a horizontal direction and data lines arranged in a vertical direction are arranged in a matrix form, and a switching device and a display device are provided between each of the scan lines and the data lines. It is. The display element may be an organic EL or a liquid crystal.

The scan lines are driven by the scan line driver circuit, and the data lines are driven by the data line driver circuit. Therefore, the selection signal output from the scan line driver circuit must drive all of the switching elements connected to the scan line. Thus, the selection signal applied to the corresponding scan line is delayed for a predetermined time and has a rising edge and a falling edge.

Accordingly, there is a period in which the falling edge of the selection signal applied to the current scan line and the rising edge of the selection signal applied to the next scan line are overlapped and simultaneously turned on. Therefore, when data is applied in a section in which scan lines overlap, data is not applied only to the current scan line but also the same data is applied to the current scan line and the neighboring scan line, thereby degrading the image quality of the display apparatus. There was a problem.

The technique disclosed in US Pat. No. 5,986,632 as a method for solving the problems of the prior art as described above is such that the selection signals applied to the scan lines do not overlap each other.

In this method, the selection signal is generated using the selection signal only for a predetermined period of the selection period of the selection signal. Accordingly, since the falling edge and the rising edge of the selection signal applied to the neighboring scan lines do not overlap, the problem that the image quality of the display device is deteriorated may be eliminated because the neighboring scan lines are simultaneously selected.

However, to implement this method, there is a problem in that an additional circuit such as a frequency divider and a mask signal generation circuit is required, which makes the configuration complicated.

An object of the present invention is to provide a method of driving an active matrix display device capable of accurately applying data only to a corresponding scan line even when a section overlaps with selection signals applied to neighboring scan lines.

Another object of the present invention is to provide a method of driving an active matrix display device which is simple to implement in hardware.

According to another aspect of the present invention, there is provided a method of driving an active matrix display device, the active matrix including a switching element and a display element between each of a plurality of scan lines and a plurality of data lines arranged in a matrix form. A method of driving a display device, the method comprising: generating a selection signal for driving the scan line and turning on switching elements connected to the scan line; the plurality of data lines after a predetermined time after the selection signal is enabled And a third step of applying data corresponding to the scan line, and a third step of sequentially performing the first and second steps with respect to the plurality of scan lines.

Fig. 1 shows the structure of an embodiment of a conventional active matrix display device.

2 shows the structure of another embodiment of a conventional active matrix display device.

3 is a timing diagram for explaining a method of driving a conventional active matrix display device.

4 is a timing diagram illustrating a method of driving an active matrix display device of the present invention.

Hereinafter, a driving method of a conventional active matrix display device will be described with reference to the accompanying drawings before explaining a method of driving the active matrix display device of the present invention.

1 shows a structure of an embodiment of a conventional active matrix display device, in which a data driving circuit 10, a scan line driving circuit 12, and scan lines S1, S2, ..., arranged in a matrix form are shown in FIG. Sm) and a liquid crystal display panel 14 having an NMOS transistor N1 and a capacitor C1 between each of the data lines D1, D2, ..., Dn.

The gate of the NMOS transistor N1 is connected to the scan line, the drain of the NMOS transistor N1 is connected to the data line, and the source is connected to one side of the capacitor C1. The other side of the capacitor C1 is connected to the ground voltage.

The structure shown in FIG. 1 shows the structure of a liquid crystal display device.

Fig. 2 shows the structure of another embodiment of a conventional active matrix display device, in which a data driving circuit 20, a scan line driving circuit 22, and scan lines S1, S2, ..., Sm and data are shown. An organic EL having a switching PMOS transistor P1, a capacitor C2, a current driving PMOS transistor P2, and an organic EL (OEL) between each of the lines D1, D2, ..., Dn. It is comprised by the display panel 24.

The gate of the PMOS transistor P1 is connected to the scan line, and the source is connected to the data line. One side of the capacitor C2 is connected to the drain of the PMOS transistor P1 and the other side is connected to the voltage Vdd. The gate of the PMOS transistor P2 is connected to the drain of the PMOS transistor P1. The anode of the organic EL (OEL) is connected to the drain of the PMOS transistor P2, and the cathode is connected to the ground voltage.

FIG. 3 is a timing diagram illustrating a driving method of a general active matrix display device, in which selection signals are sequentially applied to scan lines S1, S2, ..., Sm, and data lines D1, D2, Dn) is a timing diagram when data of a corresponding scan line is applied.

In Fig. 3, the selection signal is sequentially applied from the scan line driving circuit 22 to the scan lines S1, S2, ..., Sm, and corresponding scan lines S1, S2, ..., Sm Data is applied.

As shown in FIG. 3, in the driving method of the general active matrix display device, when the selection signal is generated from the scan line driving circuit 22, the data driving circuit 20 latches data and the data lines D1, D2,. ., Dn) will output the data.

In a typical method of driving an active matrix display device, there is a section overlapping each other at the falling edge of the selection signal applied to the scan line S1 and the rising edge of the selection signal applied to the scan line S2.

Therefore, data to be applied to the scan line S2 before the scan line S1 is completely disabled is applied to the data lines D1, D2,..., Dn so that the data is transferred only to the scan line S2. As data is applied to the scan line S1 instead of being applied, the data of the scan line S1 may be changed, thereby degrading the image quality of the display apparatus.

4 is a timing diagram illustrating a method of driving an active matrix display device according to an embodiment of the present invention, in which selection voltages are sequentially applied to scan lines S1, S2, ..., Sm, as shown in FIG. A timing diagram when data of a corresponding scan line is applied to the data lines D1, D2, ..., Dn.

As shown in FIG. 4, in the driving method of the active matrix display device of the present invention, after the selection signal is generated from the scan line driving circuit 22 and the time? T, the data driving circuit 20 latches data so that the data lines Data is output to (D1, D2, ..., Dn).

However, in the driving method of the active matrix display device of the present invention, there is a section overlapping each other at the falling edge of the selection signal applied to the scan line S1 and the rising edge of the selection signal applied to the scan line S2.

However, after the selection signal applied to the scan line S1 is completely disabled, the data to be applied to the scan line S2 is applied to the data lines D1, D2,. Only the data can be applied.

In order to implement the above-described method, it is necessary to delay the data latch time of the data driving circuit 20 or delay the time Δt on the output line of the data driving circuit 20. It is possible by providing a delay circuit.

The driving method of the active matrix display device of the present invention can be implemented by a simple method, and can improve the image quality of the display device.

Although the above has been described with reference to a preferred embodiment of the present invention, those skilled in the art will be variously modified and changed within the scope of the present invention without departing from the spirit and scope of the invention described in the claims below. I can understand that you can.

In the driving method of the active matrix display device of the present invention, the data is applied only to the desired scan line by applying the data to the data lines after a select signal is applied to the scan line.

Therefore, the image quality of the display device can be improved.

Claims (2)

A driving method of an active matrix display apparatus having a switching element and a display element between each of a plurality of scan lines and a plurality of data lines arranged in a matrix form, Generating a selection signal for driving the scan line to turn on switching elements connected to the scan line; A second step of applying data corresponding to the scan line to the plurality of data lines after the selection signal is enabled; And And a third step of sequentially performing the first and second steps with respect to the plurality of scan lines. A driving method of an active matrix display apparatus having a switching element and a display element between each of a plurality of scan lines and a plurality of data lines arranged in a matrix form, Generating a selection signal for driving the scan line to turn on switching elements connected to the scan line; A second step of applying data corresponding to the scan line to the plurality of data lines before the select signal is enabled; And And a third step of sequentially performing the first and second steps with respect to the plurality of scan lines.