KR100648672B1 - Light emitting display and test method thereof - Google Patents

Abstract

The present invention relates to a light emitting display device and an inspection method thereof.

In the light emitting display device according to the present invention, an operation state inspection portion is formed between the data driver and the display panel for supplying a data signal corresponding to the image to a display panel for displaying an image. If the data signal from the data driver is not supplied to the display panel, the operation state inspecting unit is selectively operated to supply the test signal to the display panel. The display panel operating according to the inspection signal is checked to determine whether a defect occurs. The data signal and the test signal are supplied to the data line of the display panel.

According to the present invention, since the operation state inspection unit is formed between the display panel and the data driver, the operation state of the display panel can be easily inspected through the operation state inspection unit built in the light emitting display device without any additional inspection equipment. have.

Light emitting display, inspection, switching element,

Description

LIGHT EMITTING DISPLAY AND TEST METHOD THEREOF

1 is a view showing a light emission principle of a general organic EL display device.

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

3 is a diagram illustrating a pixel circuit according to an exemplary embodiment of the present invention.

4 is a detailed structural diagram of the operation state inspecting unit illustrated in FIG. 2.

The present invention relates to a display device, and more particularly, to an organic electroluminescent (EL) display device and a test method thereof.

1 is a diagram showing a driving principle of an organic EL display device.

In general, an organic EL display device is a display device for electrically exciting a fluorescent organic compound to emit light, and is capable of representing an image by voltage or current writing NxM organic light emitting cells. The organic light emitting cell has a structure of an anode, an organic thin film, and a cathode layer. The organic thin film has a light emitting layer (EML), an electron transport layer (ETL), and a hole transport layer as shown in FIG. 1 to improve the light emission efficiency by improving the balance between electrons and holes. And a multi-layer structure including an HTL, and further include an electron injecting layer (EIL) and a hole injecting layer (HIL).

The organic light emitting cell may be driven using a simple matrix method and an active matrix method using a thin film transistor (TFT) or a MOSFET. In the simple matrix method, the anode and the cathode are orthogonal and the line is selected and driven, whereas the active driving method connects the thin film transistor and the capacitor to each indium tin oxide (ITO) pixel electrode to maintain the voltage by the capacitor capacitance. It is a driving method. In this case, the active driving method is divided into a voltage programming method and a current programming method according to the type of signal applied to maintain the voltage on the capacitor.

The organic EL display device driven in various ways as described above includes a display panel, a plurality of drive integrated circuits (for example, a data driver, a scan driver, etc.) for driving the display panel, and an image to be displayed by each drive integrated circuit. It includes a controller that provides signals and control signals. The data driver and the scan driver are driven in accordance with a control signal applied from the controller to supply a data signal to the display panel, thereby displaying an image corresponding to the data signal supplied to the display panel.

However, an abnormality may occur in a predetermined pixel circuit on the display panel, or defects such as shorting of signal lines such as data lines or scan lines may occur.

Among the conventional techniques, a technique for inspecting defects generated on a panel in an organic EL display device is disclosed in Korean Patent Application Publication No. 2004-2266 (published on 2004,1,7) and the "organic electroluminescent panel and its Defect inspection methods ". According to the related art, a color-specific test pad is formed at an end of a predetermined signal line (for example, a scan line or a data line) formed in a display panel, and an external current meter or voltmeter is connected to the test pad from the outside to operate the panel. Check the condition.

As described above, inconveniences such as a separate inspection device are always required when inspecting whether a light emitting display device has a defect occur.

Therefore, an object of the present invention is to easily detect defects on a display panel of a light emitting display device.

In order to achieve the above object, a light emitting display device according to an aspect of the present invention transmits a data signal, a plurality of data lines formed in one direction, a plurality of scan lines that transmit a selection signal and cross the data line, A display panel each formed in a region where the data line intersects the scan line and including a plurality of pixel circuits for displaying an image corresponding to an applied data signal; A data driver supplying a data signal to the data line; A scan driver supplying a selection signal to the scan line; An operation state inspection unit which supplies an inspection signal to the data line according to an inspection control signal applied to inspect the operation state of the display panel; And a controller configured to generate the test control signal and supply the test control signal to the operation state test unit. Here, an operation state inspection unit is formed between the display panel and the data driver, and selectively supplies the inspection signal to the data line when a data signal from the data driver is not applied to the data line.

The operation state inspecting unit may include a plurality of switching elements that operate in accordance with the inspection control signal and output the inspection signal to corresponding data lines. Here, an inspection control signal applied from the controller is input to the control electrode of each switching element, an inspection signal is input to the first main electrode, and a data signal of the data driver is input to the second main electrode. And second electrodes of the respective switching elements are respectively connected to the corresponding data lines.

According to another aspect of the present invention, a method of inspecting a light emitting display device includes: a scan driver supplying a scan signal, a data driver supplying a data signal, and a plurality of images driven by the scan signal to display an image corresponding to the data signal In the inspection method of a light emitting display device including a display panel including a pixel circuit and a controller for supplying a plurality of signals for performing a corresponding operation to the driving unit, a) an operation state inspection unit between the data driver and the display panel Forming; b) determining whether a data signal from the data driver is supplied to the display panel; c) when the data signal is not supplied to the display panel, operating the operation state inspecting unit and supplying a test signal for inspecting the operation state to the display panel; d) operating a pixel circuit on the display panel according to the inspection signal; And e) determining occurrence of a defect on the display panel based on an operating state of the pixel circuit.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention. Like parts are designated by like reference numerals throughout the specification. When a part is connected to another part, this includes not only a directly connected part but also an electrically connected part with another element in between.

A light emitting display device according to an embodiment of the present invention will now be described in detail with reference to the accompanying drawings. In the embodiment of the present invention, an organic EL display device using electroluminescence of an organic material is described as an example of a light emitting display device.

2 schematically illustrates a light emitting display device according to an exemplary embodiment of the present invention.

As illustrated in FIG. 2, a light emitting display device according to an exemplary embodiment of the present invention includes a display panel 100, a data driver 200, a scan driver 300, a controller 400, and an operation state inspection unit 400. do.

The display panel 100 includes a plurality of data lines Y1-Yn extending in a column direction, a plurality of scanning lines X1-Xm extending in a row direction, and a plurality of pixel circuits 110. The data lines Y1-Yn transfer a data voltage representing an image to the pixel circuit 110, and the scan lines X1-Xm transfer a selection signal to the pixel circuit 110. The pixel circuit 110 is formed in a pixel area defined by two neighboring data lines Y1 -Yn and two neighboring scan lines X1 -Xm.

The scan driver 300 sequentially applies a selection signal to the scan lines X1-Xm, and the data driver 200 simultaneously applies a data voltage to the data lines Y1-Yn. The controller 400 provides a plurality of control signals for displaying data signals and data signals to be displayed by the driving units 200 and 300.

The operation state inspecting unit 500 is formed between the data driver 200 and the display panel 100 and operates according to an applied test control signal Test to display a test voltage, which is a test signal input thereto, on the display panel 100. By supplying a line, the operation state of the display panel 100 is checked. To this end, in the exemplary embodiment of the present invention, the controller 400 provides the test control signal Test and the test voltage to test the operating state of the display panel 100 to the operating state inspecting unit 500. When the operation state inspecting unit 500 does not operate, the data voltage from the data driving unit 200 is supplied to the data line on the display panel 100.

Meanwhile, the scan driver 300 and / or the data driver 200 and / or the operation state inspector 500 may be electrically connected to the display panel 100 or adhered to and electrically connected to the display panel 100. The tape carrier package (TCP) may be mounted in the form of a chip or the like. Alternatively, a flexible printed circuit (FPC) or a film (film) attached to the display panel 100 and electrically connected to each other may be mounted in the form of a chip, such as a chip on flexible board (chip on film) method. This is called. Alternatively, the scan driver 300 and / or the data driver 200 and / or the operation state inspector 500 may be directly mounted on the glass substrate of the display panel, which is called a chip on glass (COG) method. It may also be replaced with a drive circuit formed on the glass substrate in the same layers as the scan line, data line and thin film transistor.

3 illustrates an example of a pixel circuit according to an exemplary embodiment of the present invention. The pixel circuit shown in FIG. 3 is illustrated to explain the pixel circuit according to the exemplary embodiment of the present invention and is a pixel circuit of a voltage driving method. However, the pixel circuit according to the embodiment of the present invention is not limited thereto, and for example, a current driving type pixel circuit may also be used.

As shown in Fig. 3, the pixel circuit is driven according to an organic EL element OLED, a switching transistor M2 which is driven in accordance with a selection signal applied through a scanning line, and a capacitor Cst which charges a data voltage. ) And a driving transistor M1 for supplying and driving a current corresponding to the voltage charged in the capacitor Cst to the organic EL element OLED.

In the pixel circuit having such a structure, when the switching transistor M2 is turned on according to the selection signal applied from the scanning line, the data voltage from the data line is applied to the gate of the transistor M1, and the capacitor C1 is connected between the gate and the source. The voltage V _GS across is charged. The current I _IOLED flows through the transistor M1 in response to the voltage V _GS , and the organic EL element OLED emits light in response to the current I _OLED .

At this time, the current flowing through the organic EL element OLED is represented by Equation 1 below.

Where I _OLED is the current flowing through the organic EL element OLED, V _GS is the voltage between the gate and the source of the transistor M1, V _TH is the threshold voltage of the transistor M1, V _DATA is the data voltage, and β is a constant. Indicates a value.

Hereinafter, a method of inspecting an operating state of a display panel in a light emitting display device according to an exemplary embodiment of the present invention will be described in detail with reference to FIG. 4.

4 is a detailed structural diagram of an operation state inspection unit according to an embodiment of the present invention.

As illustrated in FIG. 4, the operation state inspecting unit 500 according to an exemplary embodiment of the present invention operates according to an inspection control signal Test applied from the controller 400 to display the inspection voltage applied to the data of the display panel 100. It includes a plurality of switching elements (T1-Tn) output to the line. Each switching element T1-Tn has two main electrodes (drain electrode and source electrode) and one control electrode (gate electrode). Here, each switching element is made of a transistor of a P channel, but is not necessarily limited thereto.

The test control signal Test applied from the controller 400 is input to the gate electrodes of the respective switching elements T1 -Tn, and a test voltage is applied to one main electrode (for example, a source electrode). The other main electrode (eg, the drain electrode) is connected to the output terminal of the data driver 200, and a data voltage applied from the data driver 200 is applied thereto. The drain electrode of each switching element T1 -Tn is connected to the data line on the display panel 100 so that the test voltage or the data voltage is changed to the data line on the display panel 100 according to the operating state of the switching elements T1 -Tn. It is supplied to (Y1-Yn).

Based on the structure, a method of inspecting whether a defect occurs on the display panel is as follows.

In order to check whether the display panel has a defect, when the low level test control signal Test is output from the controller 400, the low level level is supplied to the gate electrodes of the switching elements T1 -Tn of the operation state inspecting unit 500. A signal is input to turn on each switching element T1 -Tn.

When each switching element T1 -Tn is turned on, a test voltage input to the source electrode of each switching element T1 -Tn is supplied to each data line of the display panel 100 through the connection portion. In this case, the selection signal from the scan driver 300 may be supplied to the scan lines X1-Xm of the display panel 100 so that all the scan lines are selected. In contrast, only a predetermined region of the display panel 100 is inspected. In this case, only scan lines positioned in the region may be selected.

As described above, as the test voltage is applied to each data line Y1-Yn of the display panel 100 through the operation state inspecting unit 500, each pixel circuit 110 is driven to emit light. In this case, the pixel circuit 110 in which the defect occurs does not emit light, and the user may determine whether the defect occurs by checking the light emission state of each pixel circuit 110.

On the other hand, when a predetermined image is to be displayed in the light emitting display device, the controller 400 stops outputting the test control signal Test so that the operation state inspecting unit 500 is not driven. That is, the controller 400 outputs a high level inspection control signal Test so that each switching element T1 -Tn of the operation state inspecting unit 500 is turned off so that a current corresponding to the inspection voltage passes through the switching element. Do not flow.

Accordingly, a voltage output from the data driver 200, that is, a data voltage, is applied to the data line of the display panel 100, so that the display panel 100 displays an image corresponding to the data voltage.

In the above, the light emitting display device according to the exemplary embodiment of the present invention has been described. The embodiment described above is an embodiment to which the concept of the present invention is applied, and the scope of the present invention is not limited to the above embodiment, and various modifications may be made by using the concept of the present invention as it is.

According to the present invention, in the light emitting display device, the operation state of the display panel may be changed through an operation state inspection unit formed between the display panel and the data driving without using a separate equipment or performing a cumbersome process such as disassembling the display panel. It can be easily inspected.

Claims (5)

A plurality of data lines that transmit a data signal and are formed in one direction, a plurality of scan lines that transmit a selection signal and intersect the data lines, and are formed in regions where the data lines and the scan lines intersect, respectively A display panel including a plurality of pixel circuits for displaying an image corresponding to the plurality of pixel circuits; A data driver supplying a data signal to the data line; A scan driver supplying a selection signal to the scan line; An operation state inspection unit which supplies an inspection signal to the data line according to an inspection control signal applied to inspect the operation state of the display panel; And A controller configured to generate the test control signal and supply the test control signal to the operation state test unit Including; The operation state inspection unit is formed between the display panel and the data driver, and when the data signal from the data driver is not applied to the data line, a light emitting display for selectively supplying the inspection signal to the data line. Device. The method of claim 1, The operation state inspection unit And a plurality of switching elements respectively operating in response to the inspection control signal and outputting the inspection signal to corresponding data lines. The method of claim 2, An inspection control signal applied from the controller is input to the control electrode of each switching element, an inspection signal is input to the first main electrode, and a data signal of the data driver is input to the second main electrode. And a second electrode of each of the switching elements is connected to the corresponding data line, respectively. The method of claim 3, The switching element is turned on according to a first level inspection control signal to supply the inspection signal to the data line; The switching element is turned off according to a second level inspection control signal to supply a data signal from the data driver to the data line. A display panel including a scan driver for supplying a scan signal, a data driver for supplying a data signal, and a plurality of pixel circuits driven according to the scan signal to display an image corresponding to the data signal; In the inspection method of a light emitting display device including a controller for supplying a plurality of signals for performing the a) forming an operation state inspection unit between the data driver and the display panel; b) determining whether a data signal from the data driver is supplied to the display panel; c) when the data signal is not supplied to the display panel, operating the operation state inspecting unit and supplying a test signal for inspecting the operation state to the display panel; d) operating a pixel circuit on the display panel according to the inspection signal; And e) determining occurrence of a defect on the display panel based on an operating state of the pixel circuit; Inspection method of a light emitting display device comprising a.

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