KR100739333B1 - Organic electro luminescence display device - Google Patents

Abstract

An OELD(Organic Electro Luminescence Display) device is provided to prevent an error due to an abnormal power sequence by controlling a reference voltage to be supplied to a driving circuit, through the driving circuit rather than a timing controller. An OELD device includes a pixel unit(200), a data driver(210), a scan driver(250), a DC-DC converter(260), and a timing controller(280). The pixel unit includes plural pixels, which are connected to plural data and scan lines(DL0~DLn,SL0~SLm). The data driver supplies data signals to the data lines. The scan driver sequentially supplies scan signals to the scan lines. The DC-DC converter supplies a reference voltage to the data and scan driving circuits. The timing controller controls the data and scan driving circuits. The data driving circuit generates an enable signal for controlling the operation of the DC-DC converter and supplies the generated enable signal to the DC-DC converter.

Description

Organic electroluminescence display device

1 is a circuit block diagram of a conventional passive matrix organic electroluminescent display.

2 is a block diagram of an organic electroluminescent display device according to an embodiment of the present invention.

3 is a diagram showing the circuit configuration of the DC-DC converter shown in FIG.

<Explanation of symbols for main parts of the drawings>

200: pixel portion 210: data driving circuit

250: scan drive circuit 260: DC-DC converter

270: power supply unit 280: timing control unit

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic electroluminescent display, and more particularly, to an organic electroluminescent display for controlling a reference voltage provided to a driving circuit through a driving circuit rather than a timing controller.

At present, many display devices have been proposed as flat display devices widely used in electronic notebooks, notebook computers, monitors, etc. Among them, organic electroluminescent display devices have emerged. Organic electroluminescent display devices are attracting attention as next generation display devices because they have a wide viewing angle, excellent contrast, and fast response speed.

In addition, an organic electroluminescent display device is a self-luminous display device that electrically excites fluorescent organic compounds to emit light, and because it can be driven at low voltage, it is popular as a portable device because of low power consumption.

The organic light emitting device of the organic light emitting display device has a structure in which a positive electrode and a negative electrode are separated from each other, and an organic light emitting layer is inserted between the electrodes. Here, the organic light emitting film has a multilayer structure in which a hole transport layer, a light emitting film, and an electron transport layer are laminated to transport electrons and holes and emit light, thereby improving light emission efficiency by improving electron and hole balance. . In addition, the organic light emitting layer may include a separate electron injection layer and a hole injection layer.

In the organic light emitting device, excitons are generated by injecting and recombining holes and electrons into the organic light emitting film by applying a predetermined voltage to the positive electrode and the negative electrode, respectively, and when the excitons are deactivated, light of a specific wavelength is emitted. By using the emitted light (fluorescence and phosphorescence), a desired character or image is displayed.

Such an organic electroluminescent display is driven by a passive matrix method and an active matrix method. The organic matrix light emitting device of the passive matrix type has a data line connected to both electrodes of the organic light emitting device. By defining the data line and the negative electrode as the scan line and arranging these lines in a cross shape, the pixels of the plurality of organic light emitting diodes have a matrix structure.

1 is a circuit block diagram of a conventional passive matrix organic electroluminescent display.

Referring to FIG. 1, a conventional passive matrix type organic electroluminescent display includes a plurality of data lines DL0, DL1, DL2, DL3,... DLn 120 and a row unit in a column unit. The plurality of scan lines SL0, SL1, SL2, SL3, SL4, SL5, SL6, SL7,... SLm 140 are arranged to cross each other to have n × m matrix structures. In addition, an organic light emitting layer having a multilayer structure of the organic light emitting diode 130 is inserted at a portion where the data line 120 and the scan line 140 cross each other to emit light in the organic light emitting layer.

In addition, the passive matrix organic electroluminescent display device may include a data driving circuit 110 for supplying a predetermined voltage to the plurality of data lines DL0, DL1, DL2, DL3,..., DLn; The scan driving circuit 150 for supplying a predetermined voltage to the plurality of scan lines SL0, SL1, SL2, SL3, SL4, SL5, SL6, SL7, ... SLm 140 is connected, and the data Controlling the DC-DC converter 160 which provides a reference voltage to the driving circuit and the scan driving circuit, the power supply unit 170 supplying power to the DC-DC converter 160 and the data driving circuit and the scan driving circuit The timing controller 180 is configured to be included.

The timing controller 180 generates a data driving control signal and a scan driving control signal in response to the synchronization signals supplied from the outside, which are provided to the data driving circuit and the scan driving circuit, respectively, and supplied from the outside. ) Is supplied to the data driving circuit.

In addition, the timing controller 180 provides an enable signal to the DC-DC converter 160, and the DC-DC converter 160 operates the reference voltage generated by applying the enable signal. Provided to the data driving circuit and the scan driving circuit.

That is, in the related art, the reference voltage generation of the DC-DC converter 160 supplied to the data driving circuit 110 and the scan driving circuit 150 is controlled by the timing controller 180.

However, when the generation and supply of the reference voltage are controlled by the timing controller 180, the supply timing of the reference voltage is not exactly synchronized with the operation timing of the data driving circuit and the scan driving circuit. The disadvantage is that there is a possibility of failure due to errors.

In addition, since the timing controller 180 must provide an enable signal to the DC-DC converter 160 as well as the control of the data driving circuit and the scan driving circuit, the control signal is increased by one and the FPCB pattern is increased accordingly. There is also a problem in that noise generation and patterning space is narrowed.

The present invention provides an enable signal applied to a DC-DC converter in an organic electroluminescent display device so that a reference voltage provided to the driving circuit is controlled through a driving circuit rather than a timing controller, thereby controlling the reference voltage. It is an object of the present invention to provide an organic light emitting display device in which a supply time point is synchronized with an operation time point of a data driving circuit and a scan driving circuit so as to prevent a possibility of a defect due to a power sequence error in advance.

In order to achieve the above object, an organic electroluminescent display device according to an embodiment of the present invention comprises: a pixel portion including a plurality of pixels connected to a plurality of data lines and scan lines; A data driver circuit for supplying data signals to the plurality of data lines, respectively; A scan driving circuit which sequentially supplies a scan signal to the plurality of scan lines; A DC-DC converter providing a reference voltage to the data driving circuit and the scan driving circuit; And a timing controller for controlling the data driving circuit and the scan driving circuit, wherein the data driving circuit generates an enable signal for controlling an operation of the DC-DC converter and provides the enable signal to the DC-DC converter.

Here, the enable signal may be provided in synchronization with a time when a standby mode of the data driving circuit is completed.

The apparatus may further include a power supply unit supplying an input voltage to the DC-DC converter, wherein the DC-DC converter comprises: an input power supply unit transferring an input voltage; A power supply voltage booster for boosting the input voltage; A voltage divider for distributing the boosted input voltage and returning the divided voltage to a feedback terminal of a controller; An output terminal for outputting the boosted voltage; And a control unit configured to receive an enable signal provided from the input voltage and the driving circuit to control a boost of the input voltage.

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

2 is a block diagram of an organic light emitting display device according to an exemplary embodiment of the present invention.

However, this is an organic electroluminescent display of a passive matrix type, but it is only one embodiment, but the present invention is not limited thereto.

Referring to FIG. 2, an organic electroluminescent display according to an exemplary embodiment of the present invention includes a plurality of data lines DL0, DL1, DL2, DL3,... DLn 220 and a row in a column unit. A plurality of scan lines SL0, SL1, SL2, SL3, SL4, SL5, SL6, SL7,... SLm 240 are disposed to cross each other and have n × m matrix structures. A multi-layered organic light emitting layer of the organic light emitting diode 230 is formed at a portion where the data line 220 and the scan line 240 cross each other to form pixels, and the plurality of pixels are formed in the display area, that is, the pixel portion ( 200).

In addition, the organic electroluminescent display includes a data driving circuit 210 for supplying a predetermined voltage as a data signal to a plurality of data lines DL0, DL1, DL2, DL3,..., DLn 220, and The scan driving circuit 250 for sequentially supplying a predetermined voltage as a scan signal to the plurality of scan lines SL0, SL1, SL2, SL3, SL4, SL5, SL6, SL7,. And a DC-DC converter 260 for providing a reference voltage to the data driving circuit and the scan driving circuit, a power supply unit 270 for supplying power to the DC-DC converter 260, and the data driving circuit and the scan driving circuit. The timing controller 280 is configured to control the furnace.

The timing controller 280 generates a data driving control signal and a scan driving control signal in response to the synchronization signals supplied from the outside, which are provided to the data driving circuit and the scan driving circuit, respectively, and the data supplied from the outside ( Data) is supplied to the data driving circuit.

However, in the related art, as described above, the timing controller provides an enable signal to the DC-DC converter, and the DC-DC converter operates the reference voltage generated by applying the enable signal to the data driving circuit. Although provided to the furnace and scan driving circuits, this has a disadvantage in that a defect may occur due to a power sequence error because the supply timing of the reference voltage is not exactly synchronized with the operation timings of the data driving circuit and the scan driving circuit.

In addition, since the timing controller must provide an enable signal to the DC-DC converter as well as the control of the data driving circuit and the scan driving circuit, the control signal is increased by one and the FPCB pattern is increased accordingly, thereby generating noise and patterning space. There is also this narrowing problem.

Accordingly, the present invention is characterized in that the enable signal of the DC-DC converter 260 is provided in the driving circuit, not the timing controller 280, for example, the data driving circuit 210 as shown in FIG. 2. As a result, the supply timing of the reference voltage is accurately synchronized with the operation timings of the data driving circuit 210 and the scan driving circuit 250, thereby preventing the possibility of failure due to a power sequence error in advance.

To this end, the enable signal output from the data driver circuit 210 is provided to the DC-DC converter 260 in synchronization with the time when the standby mode of the data driver circuit 210 is completed.

In addition, the CPU load may be reduced by removing one control signal of the conventional timing controller 280, and the noise generation and patterning space may be overcome by reducing the FPCB pattern.

The operation of the organic electroluminescent device as described above will be briefly described as follows. When the power output from the power supply unit 270 and the enable signal from the driving circuit 210 are provided to the DC-DC converter 260, the DC-DC converter 260 boosts the power output from the power supply unit. The DC reference voltage is generated, and the DC reference voltage is provided to the data driving circuit 210 and the scan driving circuit 250.

In this case, the time point at which the enable signal is provided is provided in synchronization with the time point when the standby mode of the data driving circuit 210 is completed, that is, the time point at which the data driving circuit 210 operates as described above. As a result, the supply timing of the reference voltage is accurately synchronized with the operation timings of the data driving circuit 210 and the scan driving circuit 250, thereby preventing the possibility of failure due to a power sequence error in advance. Will be.

Accordingly, the data driving circuit 210 simultaneously supplies a predetermined voltage to an arbitrary data line 220 at a specific time, and the scan line driving circuit 250 supplies the first scan line SL0 to the last scan line (eg SLm). Supply constant voltage sequentially. Accordingly, the excitons are generated and inactivated in the organic light emitting layer of the organic light emitting element 230 of each pixel by the voltage difference supplied from the data line 220 and the voltage supplied from the scan line 250. It emits light such as green (G) or blue (B).

3 is a diagram illustrating a circuit configuration of the DC-DC converter shown in FIG. 2.

Referring to FIG. 3, the DC-DC converter 260 includes: an input power supply unit 310 for transmitting an input voltage; A power supply voltage boosting unit 320 for boosting the input voltage; A voltage divider 330 for distributing the boosted input voltage and returning the divided voltage to a feedback terminal of a controller; An output terminal 340 for outputting the boosted voltage; A control unit 360 is provided to receive the enable signal provided from the input voltage and the driving circuit to control the step-up of the input voltage.

The input power supply unit 310 includes a first capacitor C1 and is connected to the power supply voltage booster 320 to transmit an input voltage Vin, and the power supply voltage booster 320 is the input power supply 310. The input power delivered from) is boosted to a DC reference voltage of a predetermined level and transferred to the voltage divider 330.

In this case, the power voltage boosting unit 320 includes an inductor L, a diode D, and a second capacitor C2.

The first electrode of the inductor (L) is connected to the input power supply unit 310 and the input power terminal (VIN) of the control unit 360, the second electrode is connected to the input terminal (LX) of the control unit 360 is closed circuit Therefore, the current by the input power is stored in the inductor (L).

In addition, the first electrode of the diode D, that is, the anode electrode of the diode as shown, is connected to the second electrode of the inductor L, and the second electrode of the diode, that is, the cathode electrode is connected to the output terminal. It is connected to the first node N1.

In this case, the diode D serves to rectify the voltage boosted by the inductor L. The voltage of the first node N1 connected to the cathode of the diode is a preset DC boost voltage, That is, the DC reference voltage is applied.

In addition, a second capacitor C2 is provided between the second node N2 and the second node N2 connected to the feedback terminal FB of the controller 600.

In addition, the voltage divider 330 is connected on the first resistor R1, the second node N2, and the ground terminal GND connected between the first node N1 and the second node N2. It consists of the second resistor R2.

The boosted voltage is partially distributed by the voltage divider to be fed back to the feedback terminal FB of the controller 360. The controller 360 checks whether the feedback voltage is changed to change the input voltage. By controlling the size of the DC reference voltage serves to maintain a constant size.

In addition, as described above, the enable signal provided from the data driving circuit 210 is applied to the controller 360 through the enable terminal EN, and the enable signal is applied to the controller 360. The operation is controlled.

That is, when the enable signal is applied, the operation of the DC-DC converter described above is performed.

In addition, the enable signal is provided in synchronization with the time when the standby mode (Standby mode) of the data driving circuit is completed, that is, the time when the data driving circuit is operated, so that the time when the reference voltage is output through the data driving circuit and the scan By precisely synchronizing with the operation time of the driving circuit, it is possible to prevent the possibility of failure due to the power sequence error in advance.

In addition, a third capacitor C3 may be connected to the output terminal and the ground terminal GND to the output terminal 340 to which the reference voltage is output, as shown to stabilize the output voltage.

According to the present invention, by providing the enable signal applied to the DC-DC converter in the drive circuit, the reference voltage provided to the drive circuit is controlled through the drive circuit, not the timing controller, thereby supplying the reference voltage It is precisely synchronized with the operation timings of the data driving circuit and the scan driving circuit, so that the possibility of a failure due to a power sequence error can be prevented in advance.

In addition, it is possible to overcome the problem of reducing the CPU load by eliminating one control signal of the conventional timing controller and reducing the generation of noise and patterning space by the FPCB pattern reduction.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (4)

A pixel portion including a plurality of pixels connected to the plurality of data lines and the scan lines; A data driver circuit for supplying data signals to the plurality of data lines, respectively; A scan driving circuit which sequentially supplies a scan signal to the plurality of scan lines; A DC-DC converter providing a reference voltage to the data driving circuit and the scan driving circuit; A timing controller for controlling the data driving circuit and the scan driving circuit; And the data driving circuit generates an enable signal for controlling the operation of the DC-DC converter and provides the enable signal to the DC-DC converter. The method of claim 1, And the enable signal is provided in synchronization with a point in time when a standby mode of the data driving circuit is completed. The method of claim 1, And a power supply unit for supplying an input voltage to the DC-DC converter. The method of claim 1, The DC-DC converter includes: an input power supply unit transferring an input voltage; A power supply voltage booster for boosting the input voltage; A voltage divider for distributing the boosted input voltage and returning the divided voltage to a feedback terminal of a controller; An output terminal for outputting the boosted voltage; And a controller configured to receive an enable signal provided from the input voltage and a driving circuit to control a boost of the input voltage.

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