KR101363213B1 - Organic Light Emitting Display - Google Patents

Abstract

The present invention provides a display device comprising: a display unit including two or more subpixels arranged in a matrix form on a substrate to emit different colors; Monitoring pixels arranged to monitor the subpixels corresponding to the emission color of the subpixels on the outer substrate of the display unit; And a driving unit disposed on an outer substrate of the display unit to supply driving signals to the subpixels, wherein the ground lines of the subpixels and the monitoring pixels are patterned to be separated from each other on the substrate.

OLED display, monitoring pixel, display quality

Description

[0001] The present invention relates to an organic light emitting display,

1 is a schematic plan view of an organic light emitting display according to an embodiment of the present invention.

FIG. 2 is a circuit diagram illustrating subpixels disposed in a display unit of FIG. 1; FIG.

3 is a schematic circuit diagram illustrating a power control unit disposed on an external circuit board of FIG. 1.

FIG. 4 is a layout diagram of the ground wirings of the subpixels and the monitoring pixels of FIG. 1; FIG.

DESCRIPTION OF THE REFERENCE NUMERALS

110: substrate 120: subpixels

125: monitoring pixels 130: display unit

150a: data driver 150b: scan driver

150c: power supply unit 150d: control unit

180a: sample & hold part 180b: adjusting part

The present invention relates to an organic light emitting display.

An organic electroluminescent device used in an organic electroluminescent display device is a self-luminous device in which a light emitting layer is formed between two electrodes.

The organic electroluminescent device has a top emission mode and a bottom emission mode depending on a direction in which light is emitted and a passive matrix type and an active matrix type Active Matrix).

In the organic light emitting display device using an active matrix type of the organic light emitting display device, when a signal is supplied to a plurality of sub pixels arranged in a matrix form on the display unit, a transistor, a capacitor, and an organic light emitting diode positioned inside the sub pixel are driven. The image can be displayed.

However, in the organic light emitting display device, display quality deteriorates due to deterioration of devices such as a thin film transistor, a capacitor, and an organic light emitting diode, thereby changing driving characteristics.

Thus, in order to solve such a problem, various methods have been proposed in the related art organic light emitting display device, which includes monitoring pixels on an outer substrate of the display unit and monitors sub pixels located in the display unit to compensate for the changed characteristic.

Meanwhile, among the compensation methods using the monitoring pixels, there is a method of sampling a voltage or current supplied to the monitoring pixels and adjusting a driving voltage or current to be supplied to each subpixel based on the sampled value.

In such a method, it is important to sample the voltage or current supplied to the monitoring pixels. In the conventional structure, when sampling the monitoring pixels, interference between the monitoring pixels and the sub pixels occurs, so that the accuracy of the sampling is somewhat reduced. Occurred.

An object of the present invention for solving the above problems is to provide an organic light emitting display device that can improve the display quality and implement a stable display.

According to an aspect of the present invention, there is provided a display device including two or more subpixels arranged in a matrix form on a substrate to emit different colors; Monitoring pixels arranged to monitor the subpixels corresponding to the emission color of the subpixels on the outer substrate of the display unit; And a driving unit disposed on an outer substrate of the display unit to supply driving signals to the subpixels, wherein the ground lines of the subpixels and the monitoring pixels are patterned to be separated from each other on the substrate.

The monitoring pixels may be disposed on the left side and the right side of the substrate with respect to the display unit.

A power supply unit for supplying power to at least one of the sub-pixels, the monitoring pixels, or the driving unit, a power control unit for adjusting the power supplied to the sub-pixels according to the power supplied to the monitoring pixels; It may further include a control unit for supplying a control signal to any one or more of the power supply unit or power control unit.

The power supply unit, the power control unit and the control unit may be disposed on an external circuit board.

Ground wiring of the subpixels and the monitoring pixels may be commonly connected to an external circuit board.

The power controller may sample and hold the power supplied from the power supply and supplied to the monitoring pixels, and adjust the power supplied to the subpixels based on the sampled and held values.

The power control unit includes a switch unit including first and second switches, and an element unit including one or more capacitors, a comparator, and a first transistor, wherein the first switch includes a current or voltage source and a monitoring pixel included in the power supply unit. The second switch is connected between the current or voltage source included in the power supply and the first node of the comparator, the capacitor is connected between the first node of the comparator and the ground voltage, and the first transistor is connected to the comparator. A gate is connected to a third node of the gate, a first electrode is connected to a power terminal included in the power supply unit, a second electrode is connected to power lines of subpixels included in the second node of the comparator and the display unit, And the second switch may receive a control signal from the controller to perform a switching operation.

The subpixels and the monitoring pixels can include organic light emitting diodes emitting red, green and blue, respectively.

The sub pixels can include one or more capacitors and transistors.

<Example 1>

1 is a schematic plan view of an organic light emitting display according to an embodiment of the present invention.

Referring to FIG. 1, the organic light emitting display device includes a display unit 130 including two or more subpixels 120 disposed on a substrate in a matrix form and emitting different colors. Two or more subpixels 120 may be formed in three, four or more according to the purpose. In the present invention, three subpixels, that is, red, green, and blue subpixels 120R, 120G, and 120B may be formed. ) Will be described as an example.

The red, green, and blue subpixels 120R, 120G, and 120B may each include one or more transistors, capacitors, and organic light emitting diodes. Hereinafter, a circuit configuration of the subpixels 120 will be described with reference to FIG. 2. An example will be described.

FIG. 2 is a circuit diagram illustrating subpixels disposed in the display unit of FIG. 1.

However, the circuit configuration diagram of the subpixels shown in FIG. 2 is a general circuit configuration diagram for easy understanding of the description, and the organic light emitting display device according to the present invention is not limited thereto.

As illustrated in FIG. 2, the sub pixel circuit configuration of the display unit of FIG. 1 includes a switching transistor TFT1 having a gate connected to the scan line SCAN and a first electrode connected to the data line DATA in common. do. In addition, the driving transistor TFT2 includes a gate connected to the second electrode of the switching transistor TFT1 and a first electrode connected to the first power line VDD. In addition, a capacitor C is connected between the gate of the driving transistor TFT2 and the first power line VDD. The light emitting diode D further includes a light emitting diode D connected between the second electrode of the driving transistor TFT2 and the second power line GND.

Here, the light emitting diode D may be an organic light emitting diode in which the light emitting layer is formed of an organic material layer, but may also be an inorganic light emitting diode in which the light emitting layer is formed of an inorganic material layer.

In addition to the description of the structure of the organic light emitting diode, the organic light emitting diode is formed between the organic light emitting layer (HIL), the hole transport layer (HTL), the electron transport layer (ETL) and the electron injection layer (EIL). EML) is included.

In general, the common film is selectively formed between the first electrode (pixel electrode) and the cathode of the driving transistor TFT2 serving as the anode electrode.

Each of the sub-pixels having a circuit configuration as shown in FIG. 2 emits red (R), green (G), and blue (B), which is red as shown in FIG. Note that the sub-pixels 120R, 120G, and 120B, which emit green and blue light, are also defined by one pixel unit.

Meanwhile, the transistors TFT1 and TFT2 included in each subpixel may be driven in a linear region or a saturation region by driving signals supplied from the driving units 150a and 150b shown in FIG. 1. . However, the organic light emitting display device according to the present invention advantageously adopts a digital driving method for driving the transistors TFT1 and TFT2 included in the subpixel in a linear region. Here, the digital driving method refers to a method of driving the light emitting diode D by simply turning on or off a transistor.

Referring back to FIG. 1, on the outer substrate 110 of the display unit 130, the monitoring pixels 125 arranged to monitor the subpixels 120 correspond to the emission color of the subpixels 120. Included. In the present invention, since three sub-pixels are described as an example, the monitoring pixels 125 also describe three monitoring pixels, that is, red, green, and blue monitoring pixels 125R, 125G, and 125B as an example.

Such red, green, and blue monitoring pixels 125R, 125G, and 125B may include, but are not limited to, one or more transistors and organic light emitting diodes. In addition, the red, green, and blue monitoring pixels 125R, 125G, and 125B disposed on the outer substrate 110 of the display unit 130 are disposed for each scan line S1..Sn of the display unit 130, or the scan line S1. May be placed only in an optional section of ..Sn).

Meanwhile, the monitoring pixels 125 sample and hold the power output from the power supply unit 150c and adjust the power supplied to the subpixels 120 disposed in the display unit 130 based on this. While interlocked with 180a and 180b, an example of a circuit configuration of the power regulators 180a and 180b will be described with reference to FIG. 3.

3 is a schematic circuit diagram illustrating a power control unit disposed on the external circuit board of FIG. 1. However, the circuit configuration diagrams of the power regulators 180a and 180b shown in FIG. 3 are provided only for better understanding of the description, and the organic light emitting display device according to the present invention is not limited thereto.

3 illustrates the subpixels 120 disposed in the display unit 130 of FIG. 1, the monitoring pixels 125 disposed on the outer substrate 110 of the display unit 130, and the external circuit board 170. The arranged power supply unit 150c and the power adjusting unit 180a and 180b are illustrated.

For convenience of description, the subpixels 120 and the monitoring pixels 125 disposed in the display unit 130 of FIG. 1 are shown as one light emitting diode AP and MP. In addition, the power controllers 180a and 180b are divided into a sample & hold unit 180a and a controller 180b that sample & hold power supplied to the power line of the monitoring pixels 125.

The sample & hold unit 180a includes a first switch SW1 that switches the power generated by the voltage or current source included in the power supply unit 150c to the monitoring pixels 125. In addition, the second switch SW2 switches to sample the power supplied to the monitoring pixels 125 when the power generated from the voltage or current source is supplied to the monitoring pixels 125. It also includes a capacitor C1 that holds the sampled power supply.

The first and second switches SW1 and SW2 may operate by receiving a control signal from the controller 150d disposed on the external circuit board 170. The controller 150d may be designed and arranged separately so as to control only the first and second switches SW1 and SW2, but may be switched by a register signal included in the power supply unit 150c. However, the role or position of the controller 150d described herein is not limited thereto.

The adjusting unit 180b is output from the power terminal of the power supply unit 150c based on a comparison result of the comparator OP and the comparator OP comparing the sampled and held values from the monitoring pixels 125. And a first transistor TFT1 which is an active element that controls power supplied to each subpixel 120.

By such a circuit configuration, the sample & hold unit 180a can sample and hold the power supplied to the monitoring pixels 125, and the controller 180b that has received the sampled & hold value is based on this. The power supplied to each subpixel 120 can be adjusted.

In FIG. 3, the adjusting unit 180b, which interlocks with the sample and hold unit 180a, is located on the external circuit board 170, but is divided into the outer substrate 110 and the circuit board 170 of the display unit 130. It may be located as possible.

Meanwhile, each of the sub-pixels 120 and the ground lines 120_GND and 125_GND of the monitoring pixels 125 positioned on the substrate 110 of FIG. 1 has a display area (Active Pixel) and a monitoring area (Monitor pixel). Patterned to be separated from each other. For reference, it is assumed that the ground wires 180a_GND of the sample & hold unit 180a are disposed on the external circuit board 170, and the ground wires disposed on the external circuit board 170 are partially connected in common. Hereinafter, this will be described in more detail with reference to FIG.

FIG. 4 is a layout diagram of the ground wirings of the subpixels and the monitoring pixels of FIG. 1.

FIG. 4 is not limited to this, but is to help understand how the ground wiring of the sub pixels and the monitoring pixels are routed on the substrate.

Referring to FIG. 4, the subpixels 120 disposed on the display unit 130 and the monitoring pixels 125 disposed on the outer substrate 110 of the display unit 130 are separated from each other and patterned to form a ground line ( 120_GND, 125_GND) structure.

With this structure, the ground line 120_GND of the subpixels 120 disposed in the display unit 130 and the ground line 125_GNS of the monitoring pixels 125 disposed on the outer substrate 110 of the display unit 130. Are separated from each other on the substrate 110.

However, the ground line 120_GND of the subpixels 120 and the ground line 125_GND of the monitoring pixels 125 have a structure in which they are commonly connected on an external circuit board 170 located outside. For reference, each of the ground wires 120_GND and 125_GND may be commonly connected to the ground wires 180a_GND of the sample & hold unit 180a shown in FIG. 3 on the external circuit board 170.

As such, when the sub-pixels 120 and the ground lines 120_GND and 125_GND of the monitoring pixels 125 are separated on the substrate 110, monitoring is performed in the process of sampling the voltage or current supplied to the monitoring pixels 125. The interference between the pixels 125 and the subpixels 120 may be prevented.

Meanwhile, the driving units 150a and 150b disposed on the outer substrate 110 of the display unit 130 supply the driving signals to the sub pixels 120 through the plurality of wires 140.

As shown in the drawing, the driving units 150a and 150b may be separated from the data driving unit 150a and the scan driving unit 150b and disposed on one side and the other side of the substrate 110, as well as on an external circuit board. The driving units 150a and 150b may be disposed at 170 and electrically connected to the substrate 110.

The power supply unit 150c, the controller 150d, and the power controllers 180a and 180b are disposed on the external circuit board 170.

Herein, the power supply unit 150c supplies power to at least one of the subpixels 120, the monitoring pixels 125, and the drivers 150a and 150b. When the power is supplied, the power supply unit 150c supplies one or more same or different powers to each of the red, green, and blue subpixels 120R, 120G, and 120B. The reason for this is to balance the powers of the light emitting diodes of the light emitting diodes included in each of the subpixels 120R, 120G, and 120B.

For reference, the electrical connection between the substrate 110 and the external circuit board 170 may be electrically connected by a flexible cable (eg, FPC) 165, and the like. The driving signal is applied to the sub-pixels 120 and the monitoring pixels 125 through the plurality of wires 140 and the driving units 150a and 150b disposed on the substrate 110 by being attached to the pad unit 155 disposed on the substrate 110. And power supply.

For reference, the driving units 150a and 150b are disposed on the substrate 110 and are called a chip on glass (COG) method. In addition, the driving units 150a and 150b are disposed on the flexible cable 165. The connection to the substrate 110, the driving units 150a and 150b, and the circuit board 170 may be flexibly changed according to a design method such as an on film method.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the technical configuration of the present invention described above may be modified in other specific forms by those skilled in the art to which the present invention pertains without changing its technical spirit or essential features. It will be appreciated that it may be practiced. Therefore, the embodiments described above are to be understood as illustrative and not restrictive in all aspects. In addition, the scope of the present invention is indicated by the following claims rather than the detailed description. Also, all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included within the scope of the present invention.

As described above, the present invention has an effect of providing an organic light emitting display device capable of improving display quality and implementing a stable display.

Claims (8)

A display unit including two or more subpixels arranged in a matrix on a substrate to emit different colors; Monitoring pixels arranged to monitor the sub-pixels corresponding to emission colors of the sub-pixels on an outer substrate of the display unit; A driving unit disposed on an outer substrate of the display unit to supply driving signals to the sub-pixels; A power supply unit supplying power to at least one of the sub-pixels, the monitoring pixels, and the driving line; A power controller configured to adjust power supplied to the subpixels according to power supplied to the monitoring pixels; And A control unit for supplying a control signal to any one or more of the driving unit, the power supply unit or the power control unit, Ground lines of the subpixels and the monitoring pixels are patterned to be separated from each other on the substrate, The power control unit includes a sample & hold unit and the control unit, The sample and hold unit supplies power generated from a voltage or current source to the monitoring pixels in response to a control signal supplied from the controller, and samples and holds the monitoring pixels. And the control unit compares the values sampled and held from the monitoring pixels and adjusts the power output from the power supply terminal to the sub pixels based on the result. The method of claim 1, The monitoring pixels, An organic light emitting display device disposed on left and right sides of the substrate with respect to the display unit. delete The method of claim 1, The power supply unit, the power control unit and the control unit, An organic light emitting display device disposed on an external circuit board. 5. The method of claim 4, Ground wiring of the subpixels and the monitoring pixels, An organic light emitting display device connected in common on the external circuit board. delete The method of claim 1, The power control unit, A switch unit including first and second switches, and an element unit including at least one capacitor, a comparator, and a first transistor, The first switch is connected between the current or voltage source included in the power supply and the monitoring pixels, The second switch is connected between the current or voltage source included in the power supply and the first node of the comparator, The capacitor is connected between the first node of the comparator and the ground voltage, The first transistor has a gate connected to a third node of the comparator, a first electrode connected to a power terminal included in the power supply, and a power supply of the second node of the comparator and the subpixels included in the display. The second electrode is connected to the wiring, And the first and second switches receive a control signal from the controller to perform a switching operation. The method of claim 1, wherein the subpixels are: An organic light emitting display device comprising at least one capacitor and a transistor.

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