KR20020043927A - A Driving Device For An Organic Electro-Luminescence Display Panel - Google Patents

Abstract

PURPOSE: A driving apparatus of an electro-luminescence display panel is provided to improve contrast of an electro-luminescence element by connecting a red luminant, a green luminant, and a blue luminant to different power sources, respectively. CONSTITUTION: An ITO electrode(12) a multitude of red luminants(R1,R2), a multitude of green luminants(G1,G2), and a multitude of blue luminants(B1,B2). A cathode layer(24) lies at right angles to the ITO electrode(12). The cathode layer(24) has a strip shape. The cathode layer(24) is connected with a scan drive circuit(52). A controller(50) receives a data signal and transmits output signals to the scan drive circuit(52) and a data drive circuit(54). The scan drive circuit(52) outputs a scan waveform to the cathode layer(24). The data drive circuit(54) transmits a red data signal, a green data signal, and a blue data signal according to a signal of the controller(50).

Description

A driving device for an organic electroluminescent display panel {A Driving Device For An Organic Electro-Luminescence Display Panel}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic electroluminescent display panel using an organic electroluminescent (EL) element, and more particularly, to an organic electroluminescent display panel for improving contrast of an organic electroluminescent display panel. It relates to a drive device.

In general, organic EL elements are displays that can be used as color display devices for portable terminals such as mobile phones and PDAs, vehicle-mounted display devices, and display devices for portable game machines.

1 is a schematic cross-sectional view of an organic EL display panel capable of driving a conventional passive matrix. Referring to the structure of the conventional organic EL display panel, as shown in FIG. 1, a transparent indium tin oxide (ITO) electrode (anode layer) 12 is disposed on the upper surface of the substrate 10 made of glass or film. . On the upper surface of the ITO electrode 12, a buffer layer 14 / hole injection layer 16 / hole transport layer 18 / light emitting layer 20 / electron transport layer 22 / cathode layer 24 are formed in this order.

The organic EL display panel thus formed is surrounded by a capsule (not shown) using glass or SUS, and an inert gas such as nitrogen or argon is filled at a constant pressure therein.

The operation of the conventional organic EL display panel is as follows. That is, when a voltage of "+" is applied to the ITO electrode 12 from the DC power supply 26 and a voltage of "-" is applied to the cathode layer 24, holes are injected from the ITO electrode 12 and the cathode layer ( Electrons are injected from the light source 24, and light is generated by recombination of electrons and holes in the emission layer 20. This light is emitted and displayed through the transparent ITO electrode 12 and the substrate 10.

In such a conventional organic EL display panel, the power supply side of the data signal is commonly connected to the red light emitter R, the green light emitter G, and the blue light emitter B. FIG. However, the red light emitting material R, the green light emitting material G, and the blue light emitting material B have different organic compounds for emitting light, and thus have unique characteristics (for example, electrical properties, chemical properties, etc.) for each phosphor. Their characteristics were different.

Therefore, when the same power is applied from the data signal to the light emitters having their own characteristics, there is a problem that the contrast of each light emitter is not the same, so that the coloration is inconsistent and accurate color development is impossible.

Accordingly, the present invention has been made to solve the above problems, the first object of the present invention is to apply a different power to the red light, green light, blue light emitter organic electroluminescence which can improve the overall contrast It is to provide a driving device of the display panel.

An object of the present invention as described above is to provide an organic electroluminescent display panel having an ITO electrode 12 driven by the data driving means 54 and a cathode layer 24 driven by the scan driving means 52. And scan-data synchronizing means for generating a synchronized scan signal from the data signal output from the data driving means 54 and the scan signal output from the scan driving means 52 and applying it to the cathode layer 24. It can be achieved by a driving device of an organic electroluminescent display panel.

The scan-data synchronizing means includes a power supply for the red light emitting elements R1 and R2 from the data driving means 54, a power supply for the green light emitting elements G1 and G2, and a power supply for the blue light emitting elements B1 and B2. Are separately outputted, and the voltages applied to the red light emitting elements R1 and R2, the voltages applied to the green light emitting elements G1 and G2, and the voltages applied to the blue light emitting elements B1 and B2 are different from each other. Do.

In addition, the scan-data synchronization means is connected to the output side of the data driving means 54 and the red light emitting members R1 and R2, and to the output side of the data driving means 54 and the green light emitting bodies G1 and G2. And the output side of the data driving means 54 and the blue light emitting bodies B1 and B2 are connected, and the first variable resistor 56 is connected between the output side of the data driving means 54 and the green light emitting bodies G1 and G2. The second variable resistor 58 may be connected between the output side of the data driving means 54 and the blue light emitting bodies B1 and B2.

In addition, it is appropriate that the first variable resistor 56 and / or the second variable resistor 58 have a resistance value in the range of 0 to 100 mA.

In addition, it is preferable that different power supplies are applied to the red light emitting elements R1 and R2, the green light emitting elements G1 and G2, and the blue light emitting elements B1 and B2.

Other objects, specific advantages and novel features of the present invention will become more apparent from the following detailed description and the preferred embodiments associated with the accompanying drawings.

1 is a schematic cross-sectional view of a conventional organic EL display panel,

2 is a schematic block diagram of a driving apparatus of an organic light emitting display panel according to a first embodiment of the present invention;

3 is a schematic block diagram of a driving apparatus of an organic light emitting display panel according to a second exemplary embodiment of the present invention.

<Short Description of Main Reference Signs>

10 substrate 12 ITO electrode (anode) layer,

14: buffer layer, 16: hole injection layer,

18: hole transport layer, 20: light emitting layer,

22: electron transport layer 24: cathode layer (metal layer)

50: controller, 52: scan drive circuit,

54: data driving circuit, 56: first variable resistor,

58: second variable resistor

Hereinafter, each embodiment of the present invention will be described in detail with reference to the accompanying drawings.

2 is a schematic block diagram of a driving apparatus of an organic light emitting display panel according to a first embodiment of the present invention. As shown in Fig. 2, the driving device is largely composed of a controller 50, a scan driving circuit 52 and a data driving circuit 54.

The ITO electrode 12 is composed of a plurality of red light emitters R1, R2 ..., a plurality of green light emitters G1, G2 ..., and a plurality of blue light emitters B1, B2 .... Each light emitter R.G.B. forms a strip in one direction. Although only a part of the light emitter R.G.B. is illustrated in FIG. 2 for convenience of description, the strip-shaped light emitter R.G.B.exists in a repeating manner.

The cathode layer 24 is in the shape of a strip placed in a direction orthogonal to the ITO electrode 12, and each cathode strip (aka scan metal line) is connected to the scan data driving circuit 52.

The controller 50 receives a data signal (video signal) and outputs an output signal to the scan driving circuit 52 and the data driving circuit 54, respectively.

The scan driving circuit 52 outputs a scan waveform once per frame in synchronization with the scan clock, and transmits the output scan waveform to each of the stripped cathode layers 24.

The data driving circuit 54 receives a signal from the controller 50 and outputs a red data signal, a green data signal, and a blue data signal. Each of these data signals is sent to a light emitter of a corresponding color. For example, the red data signal is sent to the red emitters R1 and R2 of the ITO electrode 12, the green data signal is sent to the green emitters G1 and G2 of the ITO electrode 12, and the blue data signal is sent to the green emitters G1 and G2. It is sent to the blue light emitting bodies B1 and B2 of the ITO electrode 12.

Accordingly, the panel receives the data signal from the data driver circuit 54 and the scan signal from the scan driver circuit 52 to generate colors by the synchronized scan signal. At this time, when the voltage of the data signal on the output side of the data driving circuit 54 is output differently in consideration of the characteristics of each light emitting device R.G.B., the contrast of each light emitting device R.G.B.

3 is a schematic block diagram of a driving apparatus of an organic light emitting display panel according to a second exemplary embodiment of the present invention. As shown in FIG. 3, the second embodiment is similar to the first embodiment, and there is a difference in the connection relationship between the data driving circuit 54 and the light emitting units R, G, and B. As shown in FIG. That is, a variable resistor is used to apply different voltages to the respective light emitters R, G, and B.

That is, only one data signal is output from the data driving circuit 54, and the data signal is sent directly to the red light emitting members R1 and R2 of the ITO electrode 24. The output side data signal of the data driving circuit 54 is branched in parallel to connect one side of the first variable resistor 56, and the other side of the first variable resistor 56 is applied to the green light emitting bodies G1 and G2. In the same manner, the output side data signal of the data driving circuit 54 is branched in parallel to connect one side of the second variable resistor 58, and the other side of the second variable resistor 58 is applied to the blue light emitting bodies B1 and B2. do.

The luminance of the green light emitting bodies G1 and G2 can be adjusted by adjusting the resistance of the first variable resistor 56 in consideration of the characteristics of each light emitter, and the blue light emitting body by adjusting the resistance of the second variable resistor 58. The luminance of (B1, B2) can be adjusted.

It is preferable that the first variable resistor 56 and / or the second variable resistor 58 have a resistance value in the range of 0 to 100 mA, but when the characteristic variation of the light emitter is larger, a wider range of variable resistor can be used. If you want to change the voltage precisely, you can replace it with a variable resistor with a small adjustable width. At this time, it is a matter of course to select the capacity of the variable resistor according to the size, capacity and power of the panel.

According to the driving device of the organic light emitting display panel of the present invention as described above, there is an effect that the overall contrast can be improved by applying different power to the red, green, and blue light emitting body.

This allows for more accurate color expression.

Although the present invention has been described in connection with the above-mentioned preferred embodiments, it is possible to make various modifications or variations without departing from the spirit and scope of the invention. Accordingly, the appended claims will cover such modifications and variations as fall within the spirit of the invention.

Claims (5)

In an organic electroluminescent display panel having an ITO electrode 12 driven by the data driving means 54 and a cathode layer 24 driven by the scan driving means 52, A scan-data synchronizing means for generating a synchronized scan signal from the data signal output from the data driving means 54 and the scan signal output from the scan driving means 52 and applying it to the cathode layer 24; An apparatus for driving an organic light emitting display panel, characterized in that. The method of claim 1, wherein the scan-data synchronization means, The power supply for the red light emitting elements R1 and R2, the power supply for the green light emitting elements G1 and G2, and the power supply for the blue light emitting elements B1 and B2 are separately output from the data driving means 54, The voltage applied to the red light emitting elements R1 and R2, the voltage applied to the green light emitting elements G1 and G2, and the voltages applied to the blue light emitting elements B1 and B2 are different from each other. Drive. The method of claim 1, wherein the scan-data synchronization means, The output side of the data driving means 54 and the red light emitting members R1 and R2 are connected, The output side of the data driving means 54 and the green light emitting bodies G1 and G2 are connected, The output side of the data driving means 54 and the blue light emitting bodies B1 and B2 are connected, A first variable resistor 56 is connected between the output side of the data driving means 54 and the green light emitting bodies G1 and G2. And a second variable resistor (58) connected between the output side of said data driving means (54) and said blue light emitting bodies (B1, B2). 4. The driving device of an organic electroluminescent display panel according to claim 3, wherein the first variable resistor (56) and / or the second variable resistor (58) have a resistance value in the range of 0 to 100 mA. The organic electric field according to claim 3 or 4, wherein different power sources are applied to the red light emitters R1 and R2, the green light emitters G1 and G2, and the blue light emitters B1 and B2. Driving device of a light emitting display panel.