KR102645963B1 - Sub-pixel, gate driver and organic light emitting display device - Google Patents

Abstract

The present embodiments relate to an organic light emitting display device and a driving method that improve video response time and picture quality while maintaining a constant video frame frequency, and are related to a sense sensor before applying a scan signal for driving subpixels in the video frame section. By applying a signal, the non-light-emitting section can be maintained before the light-emitting section. By allowing a non-emission section and an emitted section to exist within one video frame section, it provides the same effect as if a video frame due to the non-emission section is inserted between video frames, providing an effect such as high-speed driving without increasing the frame frequency. It improves the video response time and image quality of organic light emitting display devices.

Description

Subpixel, gate driver and organic light emitting display device {SUB-PIXEL, GATE DRIVER AND ORGANIC LIGHT EMITTING DISPLAY DEVICE}

These embodiments relate to an organic light emitting display device, a driving method thereof, and a gate driver and subpixel included in the organic light emitting display device.

Organic light emitting displays, which have recently been in the spotlight as display devices, use organic light emitting diodes (OLEDs: Organic Light Emitting Diodes) that emit light on their own, and have advantages in terms of fast response speed, luminous efficiency, brightness, and viewing angle.

This organic light emitting display device includes an organic light emitting display panel in which a plurality of gate lines and a plurality of data lines are arranged and a plurality of subpixels defined by the gate lines and data lines are arranged, and a plurality of gate lines are sequentially driven. It may include a gate driver, a data driver that drives a plurality of data lines, and a controller that controls the operation of the gate driver and data driver.

Organic light emitting diodes are disposed in multiple subpixels, and images are displayed by controlling the brightness of subpixels selected by a scan signal according to the gradation of data.

These organic light emitting display devices have the advantage of fast response speed, but as the demand for higher response speed is increasing, the need for high-speed driving to improve response speed is increasing.

However, for high-speed operation, data input must be performed at high speed, which is difficult because it requires high performance of the data driver. In particular, because the load on the data line is large in large areas and high resolutions, there are limitations in applying high-speed driving to current organic light emitting display devices.

The purpose of the present embodiments is to provide a method of driving an organic light emitting display device that can improve video response time and image quality while using the same frame frequency of the organic light emitting display device.

The purpose of the present embodiments is to provide a gate driver and method for driving subpixels to improve video response time and image quality at the same frame frequency.

In one aspect, the present embodiments include an organic light emitting display panel in which a plurality of gate lines and a plurality of data lines are arranged and a plurality of subpixels defined in an area where the gate lines and data lines intersect, and an organic light emitting display panel. Provided is an organic light emitting display device including a gate driver that drives a plurality of gate lines arranged in.

Each subpixel disposed in such an organic light emitting display device includes an organic light emitting diode, a driving transistor that drives the organic light emitting diode, a first transistor connected between the first node of the driving transistor and the data line, and a first transistor of the driving transistor. It includes a second transistor connected between two nodes and a reference voltage line, and a storage capacitor connected between the first node and the second node of the driving transistor.

In this subpixel structure, the second transistor is turned on before the first transistor is turned on in the video frame section and is turned off when the first transistor is turned off.

Here, the video frame section includes a first section in which the second transistor is turned on while the first transistor is off, a second section in which the first transistor is turned on while the second transistor is on, and a first section in which the first transistor is turned on. It is divided into a third section in which the transistor and the second transistor are turned off.

The organic light emitting diode included in the subpixel does not emit light in the first and second sections of the image frame section and emits light in the third section, and the sum of the lengths of the first section and the second section is the length of the third section and It may be equal to or shorter than the length of the third section.

The gate driver of such an organic light emitting display device sequentially outputs a second scan signal that turns on the second transistors included in a plurality of subpixels during the image frame section, and starts with the second transistor turned on. When the set time elapses, the first scan signal that turns on the first transistor included in the plurality of subpixels is sequentially output.

This gate driver may output the second scan signal so that sections in which the second scan signal sequentially output to the second transistor included in the different subpixels are at a high level overlap with each other.

Additionally, the gate driver may output the first scan signal so that the first scan signal changes from high level to low level when the second scan signal changes from high level to low level.

Additionally, the gate driver may increase the output speed of the first scan signal in proportion to the ratio that the preset time occupies in the video frame section.

From another aspect, the present embodiments include a scan signal output unit that controls the driving of a first transistor that controls the application of a data voltage to the first node of the driving transistor included in the subpixel in the image frame section, and a second node of the driving transistor. 2 Controls the driving of the second transistor, which controls the application of the reference voltage to the node, and sends a second scan signal for driving the second transistor before the first scan signal for driving the first transistor is output by the scan signal output unit. A gate driver including a sense signal output unit that outputs is provided.

In another aspect, the present embodiments include an organic light-emitting diode, a driving transistor for driving the organic light-emitting diode, a first transistor connected between the first node of the driving transistor and the data line, and a first node of the driving transistor and a first transistor. It is connected between the storage capacitor connected between the two nodes and the second node of the driving transistor and the reference voltage line, and is turned on before the first transistor is turned on in the video frame section, and the point at which the first transistor is turned off. A subpixel including a second transistor that is turned off is provided.

According to the present embodiments, by applying a sense signal before applying a scan signal for driving a subpixel in an image frame section, a non-emission section is included before an emission section in the image frame section, so that there are no frames between image frames. Provides the same effect as inserted.

According to the present embodiments, a high-speed driving effect as if a frame is inserted between video frames is provided without increasing the frame frequency, thereby improving video response time and image quality at the same frame frequency.

1 is a diagram showing a schematic configuration of an organic light emitting display device according to the present embodiments.
Figure 2 is a diagram showing an example of a subpixel structure included in an organic light emitting display device according to the present embodiments.
Figure 3 is a diagram showing the timing of signals applied to drive subpixels of the organic light emitting display device according to the present embodiments.
Figure 4 is a diagram for explaining the general driving and high-speed driving methods of the organic light emitting display device according to the present embodiments.
Figure 5 is a diagram showing signal waveforms of data voltages or scan signals according to normal driving and high-speed driving of the organic light emitting display device according to the present embodiments.
FIG. 6 is a diagram illustrating an example of the timing of a signal applied to a subpixel in order to provide the effect of high-speed driving at the same frame frequency in the organic light emitting display device according to the present embodiments.
7 to 9 are diagrams to explain how subpixels of an organic light emitting display device according to the present embodiments operate in each section of an image frame.
Figure 10 is a diagram showing an example of a section in which a subpixel of an organic light emitting display device according to the present embodiments emits light and a section in which it does not emit light in an image frame section.
Figure 11 is a diagram showing the schematic configuration of a gate driver in the organic light emitting display device according to the present embodiments.
FIG. 12 is a diagram illustrating a process of a method of driving an organic light emitting display device according to the present embodiments.

Hereinafter, some embodiments of the present invention will be described in detail with reference to the exemplary drawings. In adding reference numerals to components in each drawing, identical components may have the same reference numerals as much as possible even if they are shown in different drawings. Additionally, when describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description may be omitted.

Additionally, when describing the components of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are only used to distinguish the component from other components, and the essence, sequence, order, or number of the components are not limited by the term. When a component is described as being “connected,” “coupled,” or “connected” to another component, that component may be directly connected or connected to that other component, but there are no other components between each component. It should be understood that may be “interposed” or that each component may be “connected,” “combined,” or “connected” through other components.

Figure 1 is a diagram showing the schematic configuration of an organic light emitting display device 100 according to the present embodiments.

Referring to FIG. 1, the organic light emitting display device 100 according to the present embodiments has a plurality of gate lines (GL) and a plurality of data lines (DL) arranged, and the gate lines (GL) and data lines (DL) An organic light emitting display panel 110 on which a plurality of subpixels defined by , a gate driver 120 driving a plurality of gate lines GL, and a data driver driving a plurality of data lines DL ( 130) and a controller 140 that controls the operation of the gate driver 120 and the data driver 130.

The gate driver 120 sequentially drives a plurality of gate lines GL by sequentially supplying a scan signal Scan to the plurality of gate lines GL. Here, the gate driver 120 is also called a “scan driver.”

This gate driver 120 may include at least one gate driver integrated circuit (GDIC: Gate Driver Integrated Circuit).

Each gate driver integrated circuit (GDIC) may include a shift register, a level shifter, etc.

The gate driver 120 sequentially supplies scan signals Scan of the ON voltage or OFF voltage to the plurality of gate lines GL under the control of the controller 140.

The data driver 130 drives multiple data lines DL by supplying data voltages to the multiple data lines DL. Here, the data driver 130 is also called a “source driver.”

This data driver 130 may include at least one source driver integrated circuit (SDIC) and drive multiple data lines DL.

Each source driver integrated circuit (SDIC) may include a shift register, a latch circuit, a digital to analog converter (DAC), an output buffer, and the like. A digital converter (ADC: Analog to Digital Converter) may be further included.

When a specific gate line GL is opened by the gate driver 120, the data driver 130 converts the image data received from the controller 140 into an analog data voltage and supplies it to a plurality of data lines DL. do.

The controller 140 controls the gate driver 120 and the data driver 130 by supplying various control signals to the gate driver 120 and the data driver 130.

This controller 140 starts scanning according to the timing implemented in each frame, converts the input image data input from the outside to fit the data signal format used by the data driver 130, and outputs the converted image data. , Control data drive at an appropriate time according to the scan.

This controller 140 may be a timing controller used in typical display technology, or may be a control device that performs other control functions, including a timing controller.

The controller 140 provides various timing signals including a vertical synchronization signal (Vsync), a horizontal synchronization signal (Hsync), an input data enable (DE) signal, a clock signal (CLK), etc., along with input image data. Receive data from external sources (e.g. host system).

The controller 140 receives timing signals such as a vertical synchronization signal (Vsync), a horizontal synchronization signal (Hsync), an input DE signal, and a clock signal in order to control the gate driver 120 and the data driver 130, Various control signals are generated and output to the gate driver 120 and data driver 130.

For example, in order to control the gate driver 120, the controller 140 generates a gate start pulse (GSP), a gate shift clock (GSC), and a gate output enable signal (GOE: Outputs various gate control signals (GCS: Gate Control Signal) including Gate Output Enable.

Here, the gate start pulse (GSP) controls the operation start timing of one or more gate driver integrated circuits constituting the gate driver 120. The gate shift clock (GSC) is a clock signal commonly input to one or more gate driver integrated circuits, and controls the shift timing of a scan signal (Scan, gate pulse). The gate output enable signal (GOE) specifies timing information of one or more gate driver integrated circuits.

In addition, the controller 140 uses a source start pulse (SSP), a source sampling clock (SSC), and a source output enable signal (SOE) to control the data driver 130. Outputs various data control signals (DCS: Data Control Signal) including Enable).

Here, the source start pulse (SSP) controls the data sampling start timing of one or more source driver integrated circuits constituting the data driver 130. The source sampling clock (SSC) is a clock signal that controls the sampling timing of data in each source driver integrated circuit. The source output enable signal (SOE) controls the output timing of the data driver 130.

Each subpixel arranged in the organic light emitting display panel 110 includes an organic light emitting diode (OLED), which is a self-light emitting device, and a driving transistor (DRT: Driving Transistor) for driving the organic light emitting diode (OLED). It is composed of circuit elements.

The type and number of circuit elements constituting each subpixel may be determined in various ways depending on the provided function and design method.

Figure 2 shows an example of the subpixel structure of the organic light emitting display device 100 according to the present embodiments.

Referring to FIG. 2, in the organic light emitting display device 100 according to the present embodiments, each subpixel includes an organic light emitting diode (OLED), a driving transistor (DRT) that drives the organic light emitting diode (OLED), and A first transistor (TR1) electrically connected to the first node (N1) corresponding to the gate node of the driving transistor (DRT), and a data voltage corresponding to the image signal voltage or a voltage corresponding thereto are applied for a set period of time (e.g., 1 frame). A storage capacitor (Cst: Storage Capacitor) maintained for (time or 1/2 frame time, etc.), and a second transistor (TR2) connected between the second node (N2) of the driving transistor (DRT) and the reference voltage line (RVL) may further include.

The organic light emitting diode (OLED) may be composed of a first electrode (eg, an anode electrode or cathode electrode), an organic layer, and a second electrode (eg, a cathode electrode or anode electrode), and the second electrode of the organic light emitting diode (OLED) A ground voltage (EVSS) may be applied to the electrode.

The driving transistor (DRT) drives the organic light emitting diode (OLED) by supplying driving current to the organic light emitting diode (OLED).

The driving transistor DRT has a first node N1, a second node N2, and a third node N3.

The first node N1 of the driving transistor DRT is a node corresponding to the gate node and may be electrically connected to the source node or drain node of the first transistor TR1.

The second node N2 of the driving transistor DRT may be electrically connected to the first electrode of the organic light emitting diode (OLED) and may be a source node or a drain node.

The third node N3 of the driving transistor DRT is a node to which the driving voltage EVDD is applied, and may be electrically connected to a driving voltage line that supplies the driving voltage EVDD, and may be a drain node or a source node. .

The first transistor TR1 is electrically connected between the data line DL and the first node N1 of the driving transistor DRT, and applies a scan signal Scan to the gate node through the gate line GL. can be received and controlled.

This first transistor (TR1) is turned on by the scan signal (Scan) and can transmit the data voltage (Vdata) supplied from the data line (DL) to the first node (N1) of the driving transistor (DRT). there is.

The storage capacitor Cst may be electrically connected between the first node N1 and the second node N2 of the driving transistor DRT.

The second transistor (TR2) is electrically connected between the second node (N2) of the driving transistor (DRT) and the reference voltage line (RVL) that supplies a reference voltage (Vref: Reference Voltage), and a scan signal ( It can be controlled by receiving a sense signal, a type of scan.

This second transistor TR2 is turned on by the sense signal Sense and applies the reference voltage Vref supplied through the reference voltage line RVL to the second node N2 of the driving transistor DRT. .

As shown in FIG. 2, the switching operations of the first transistor TR1 and the second transistor TR2 may be controlled independently.

In this case, the scan signal Scan applied to the gate node of the first transistor TR1 and the sense signal applied to the gate node of the second transistor TR2 may be different gate signals.

That is, the first transistor TR1 receives the scan signal Scan to the gate node through the first gate line GL1, and the second transistor TR2 receives the sense signal Sense through the second gate line GL2. ) is authorized as a gate node.

In this case, two gate lines (GL1 and GL2) for gate driving must be arranged in the organic light emitting display panel 110.

Through the driving of the first transistor TR1 and the second transistor TR2, the organic light emitting diode (OLED) included in the subpixel is controlled to emit light to display an image.

Figure 3 shows the timing of signals applied to the first transistor TR1 and the second transistor TR2 in the image frame section in which these subpixels are driven.

Referring to FIG. 3, a scan signal (Scan) and a sense signal (Sense) are applied at the same timing through the gate line (GL) disposed in the first row of the organic light emitting display panel 110 in the image frame section.

When the scan signal Scan is applied, the first transistor TR1 is turned on and the data voltage Vdata supplied through the data line DL is applied to the first node N1 of the driving transistor DRT.

When the sense signal (Sense) is applied, the second transistor (TR2) is turned on and the reference voltage (Vref) supplied through the reference voltage line (RVL) is applied to the second node (N2) of the driving transistor (DRT). .

When the scan signal (Scan) and the sense signal (Sense) become low level at the same time, the first transistor (TR1) and the second transistor (TR2) are turned off, and the voltage of the second node (N2) of the driving transistor (DRT) This rises.

When the voltage of the second node (N2) of the driving transistor (DRT) increases and exceeds the threshold voltage of the organic light-emitting diode (OLED), the organic light-emitting diode (OLED) emits light to display brightness according to the gradation of the data voltage (Vdata). I do it.

These scan signals (Scan) and sense signals (Sense) are sequentially applied to the gate lines (GL) disposed on the organic light emitting display panel 110 and drive subpixels to display images.

The organic light emitting display device 100 driven in this manner must apply scan signals and sense signals applied to subpixels as quickly as the increased frame frequency in order to improve video response time and image quality.

FIG. 4 shows a case in which the organic light emitting display device 100 according to the present embodiments is driven in a normal operation and a case in which a high-speed operation is performed. The general operation is an example of a frame frequency of 120 Hz, and the high-speed operation is an example of a normal operation. The example is 240Hz, which is twice the frame frequency, but is not limited to this.

Referring to FIG. 4, in the case of general driving at a frame frequency corresponding to 120Hz, subpixel rows are sequentially driven one by one during one frame section.

In the case of high-speed driving at a frame frequency equivalent to 240Hz, subpixel rows are sequentially driven two at a time during one frame section.

Therefore, in the case of high-speed driving at a frame frequency corresponding to 240Hz, gate driving and data driving must be performed at twice the speed compared to general driving at 120Hz. In other words, the supply (input) of the scan signal (Scan) and data voltage (Vdata) must be done twice as fast.

Therefore, in order to reduce video response time and drive at high speeds to improve picture quality, high-performance gate drivers 120 and data drivers 130 are required.

However, when the organic light emitting display panel 110 is designed with a large area and high resolution, the RC load of the gate line (GL) and data line (DL) is large, so a frame frequency faster than 120Hz (e.g. There are limitations that make it difficult to drive at high speeds (240Hz).

FIG. 5 shows the waveforms of a scan signal (Scan) or a data voltage (Vdata) applied when the organic light emitting display device 100 according to the present embodiments is driven in normal operation and high speed operation.

Looking at the signal waveform shown in FIG. 5 as the signal waveform of a scan signal, when driving at high speed with a frame frequency faster than 120Hz (e.g., 240Hz), the voltage of the gate line GL does not change quickly. can not do it.

Accordingly, at the time of driving, the voltage of the gate line GL may be lower than the desired voltage value by a certain voltage value (ΔV).

Due to this voltage error, the gate line GL cannot be turned on and off at normal timing, which may cause screen abnormalities.

Looking at the signal waveform shown in FIG. 5 as the signal waveform of the data voltage (Vdata), when driving at high speed with a frame frequency (e.g., 240Hz) faster than 120Hz, data charging cannot be performed quickly.

Accordingly, the voltage charged in the storage capacitor Cst at the time of driving may be lower than the desired voltage value by a certain voltage ΔV.

Due to this data charging error, screen abnormalities such as screen dragging and image overlapping may occur.

Accordingly, the demand for high-speed driving is increasing to improve the video response time and image quality of the organic light emitting display device 100, but high-speed driving is not possible due to limitations in the performance of the gate driver 120 and data driver 130. There are problems that are difficult to implement.

The organic light emitting display device 100 according to the present embodiments does not increase the frame frequency of the organic light emitting display device 100 and provides the effect of high-speed driving through timing control of signals applied to subpixels during normal driving. An organic light emitting display device (100) and a method of driving the same are provided.

Figure 6 shows an example of the timing of a signal applied during an image frame section to a subpixel in the organic light emitting display device 100 according to the present embodiments.

Referring to FIG. 6, a sense signal (Sense) is applied to the second transistor (TR2) before the scan signal (Scan) is applied to the first transistor (TR1) disposed in the subpixel in the image frame section.

A sense signal (Sense) is applied to the second transistor (TR2), and after a certain period of time, a scan signal (Scan) is applied to the first transistor (TR1).

After the scan signal Scan is applied to the first transistor TR1, the scan signal Scan and the sense signal Sense change to low level at the same timing.

That is, one video frame section includes a first section in which the second transistor (TR2) is turned on before the first transistor (TR1) is turned on, and a state in which the second transistor (TR2) is turned on. It is divided into a second section in which the first transistor TR1 is turned on, and a third section in which the first transistor TR1 and the second transistor TR2 are turned off.

In the first section of the video frame section, since the scan signal (Scan) is not applied to the first transistor (TR1), the first transistor (TR1) is in an off state, and the first node (N1) of the driving transistor (DRT) The data voltage (Vdata) is not applied.

And, since the sense signal (Sense) is applied to the second transistor (TR2), the second transistor (TR2) is in the on state, and the reference voltage (Vref) is applied to the second node (N2) of the driving transistor (DRT). It will happen.

Therefore, since the organic light emitting diode (OLED) included in the subpixel does not emit light in the first section, the subpixel driven by the corresponding scan signal (Scan) and sense signal (Sense) is in a non-emission state.

In the second section of the video frame section, the scan signal (Scan) is applied to the first transistor (TR1), so the first transistor (TR1) is turned on, and data is transmitted to the first node (N1) of the driving transistor (DRT). Voltage (Vdata) is applied.

Since the sense signal Sense is at a high level, the second transistor TR2 is turned on, and the reference voltage Vref is applied to the second node N2 of the driving transistor DRT.

Since the voltage of the second node (N2) of the driving transistor (DRT) is the reference voltage (Vref), the organic light emitting diode (OLED) maintains a non-emitting state in the second section of the image frame section.

In the third section of the video frame section, as the scan signal (Scan) and the sense signal (Sense) change to low level, the first transistor (TR1) and the second transistor (TR2) are turned off, and the driving transistor (DRT) ) The voltage of the second node (N2) increases.

As the voltage of the second node N2 of the driving transistor DRT increases, voltage is applied to the first electrode of the organic light emitting diode (OLED), so the brightness according to the gradation of the data voltage applied through the data line DL It is in a state of emitting light.

Therefore, according to the present embodiments, by applying the sense signal (Sense) to the second transistor (TR2) before the scan signal (Scan) is applied to the first transistor (TR1) in the image frame section, It is possible to maintain a non-luminous state during the first section.

In addition, by outputting the sense signal (Sense) so that the section in which the sense signal (Sense) applied to the subpixel driven by another gate line (GL) disposed on the organic light emitting display panel 110 is at a high level overlaps, sufficient Make sure to create a non-luminous section.

Since the non-emission state is maintained in the video frame section, there is a non-emission section between the light emitting sections, providing the same effect as if a video frame (e.g., a black video frame) is inserted between frames.

In other words, by allowing a non-light emitting section to exist for a certain period of time between light emitting sections, it provides the same effect as expressing an image frame by increasing the frame frequency without increasing the frame frequency.

Through this, video response time and image quality can be improved without being limited by the performance of the gate driver 120 and data driver 130 or the load within the organic light emitting display panel 110.

7 to 9 specifically show how the organic light emitting display device 100 according to the present embodiments operates in each section of the video frame section.

Referring to FIG. 7, it shows the first section of the video frame section, and before the scan signal (Scan) is applied to the first transistor (TR1) in the first section of the video frame, a sense signal is applied to the second transistor (TR2). (Sense) is authorized.

That is, a high-level sense signal (Sense) is applied in a section where the scan signal (Scan) is at a low level, so that only the second transistor (TR2) is turned on while the first transistor (TR1) is in an off state.

Since the first transistor TR1 is in the off state, the data voltage Vdata is not applied to the first node N1 of the driving transistor DRT, and the reference voltage is applied to the second node N2 of the driving transistor DRT. Vref) is approved.

Accordingly, the organic light emitting diode (OLED) maintains a non-emitting state in a section where the sense signal (Sense) is at a high level before the high level scan signal (Scan) is applied.

Rather than applying the scan signal (Scan) and the sense signal (Sense) at the same time, the video frame section includes a first section in which the sense signal (Sense) is applied before the scan signal (Scan) is applied, thereby reducing the ratio within the video frame section. Ensure that a light emitting section exists.

By ensuring that this non-emission section exists between the light-emitting section and the light-emitting section, the effect of high-speed driving is provided as if an image frame due to the non-emission section is inserted between image frames.

Referring to FIG. 8, which shows the second section of the video frame section, the scan signal (Scan) applied to the first transistor (TR1) while the sense signal (Sense) applied to the second transistor (TR2) is at high level. ) changes to high level.

As the high level scan signal Scan is applied, the first transistor TR1 is turned on and the data voltage Vdata is applied to the first node N1 of the driving transistor DRT.

Since the second transistor TR2 remains turned on in the second section of the video frame section, the organic light emitting diode (OLED) included in the corresponding subpixel maintains a non-light emitting state.

Accordingly, the subpixel is in a non-emission state during the first and second sections of the video frame section, and by adjusting the length of the first section, the non-emission section and the light-emitting section within the image frame can be adjusted.

Referring to FIG. 9, the third section of the image frame is shown, where the high level scan signal (Scan) and sense signal (Sense) are simultaneously changed to low level.

As the scan signal (Scan) and the sense signal (Sense) change to low level, the first transistor (TR1) and the second transistor (TR2) are turned off, and the voltage of the second node (N2) of the driving transistor (DRT) This rises.

When the voltage of the second node (N2) of the driving transistor (DRT), that is, the voltage applied to the first electrode of the organic light-emitting diode (OLED), is higher than the threshold voltage of the organic light-emitting diode (OLED), the organic light-emitting diode (OLED) emits light and displays brightness according to the gradation of the data voltage (Vdata).

Accordingly, the third section of the video frame section becomes a light-emitting section, and a non-light-emitting section and a light-emitting section exist depending on the timing at which the sense signal (Sense) is applied within the video frame section.

At this time, the driving speed of the scan signal (Scan) output in the third section of the video frame section is increased according to the ratio that the non-emission section occupies within the video frame section.

For example, when the non-emission section within the video frame section is 10%, the third section of the video frame is driven at 10% high speed.

Therefore, even if the light-emitting section is shortened due to the non-light-emitting section within the video frame section, the data you want to display can be displayed through the video frame, and the video response time and image quality can be improved by inserting the non-light-emitting section. do.

Figure 10 shows an example in which this video frame section is divided into a non-emission section and an emission section.

Referring to FIG. 10, as shown at 1010 in FIG. 10, by setting a long section in which only the sense signal (Sense) is at a high level before the scan signal (Scan) becomes high level, a non-emission section within the video frame section is created. The length of the and emission sections can be set to be the same.

In this case, since the non-emission section and the emitted section within the video frame are displayed with the same length, the same effect as displaying two video frames in one video frame section can be provided.

Since it provides the same effect as displaying two video frames in one video frame section, it can provide the same effect as driving by doubling the frame frequency.

At this time, as the light-emitting section becomes shorter, high-speed driving in the light-emitting section is required, so the length of the non-light-emitting section can be set to be shorter than the length of the light-emitting section.

As shown at 1020 in FIG. 10, the length of the non-emitting section within the video frame section can be set to be shorter than the length of the emitting section, and the length of the non-emitting section is 10% of the video frame section as in the example above. It may be a corresponding section.

By allowing a non-emission section and an emitted section to exist in one video frame section, the effect of driving with an increased frame frequency is provided, and by setting the length of the non-emission section to be short, the burden of high-speed driving in the emitted section is reduced. .

FIG. 11 shows a schematic configuration of a gate driver 120 that controls the output of a scan signal (Scan) and a sense signal (Sense) to subpixels in the organic light emitting display device 100 according to the present embodiments.

Referring to FIG. 11, the gate driver 120 according to the present embodiments may include a scan signal output unit 121 and a sense signal output unit 122.

The scan signal output unit 121 outputs a scan signal (Scan) that controls driving of the first transistor (TR1) to subpixels disposed on the organic light emitting display panel (110).

The scan signal output unit 121 may sequentially output a scan signal Scan according to the gate line GL disposed on the organic light emitting display panel 110.

The sense signal output unit 122 controls the output of a sense signal (Sense) that controls the driving of the second transistor (TR2) included in the subpixel.

The sense signal output unit 122 can sequentially output the sense signal (Sense) according to the timing at which the scan signal (Scan) is applied to the subpixel, and the scan signal (Scan) is applied to the subpixel in the image frame section. A sense signal (Sense) is output before being activated.

In addition, the scan signal output unit 121 sequentially outputs the scan signal (Scan) after the sense signal (Sense) is output in the image frame section, thereby generating the sense signal (Sense) before the scan signal (Scan) is output. ) allows the applied subpixel to remain in a non-emitting state.

In other words, by adjusting the output timing of the scan signal (Scan) and the sense signal (Sense) applied to the subpixels in the image frame section, a non-emission section and an emitted section can exist within one image frame section.

By adjusting the output timing of the scan signal (Scan) and the sense signal (Sense) without increasing the driving frequency of the gate driver 120 to ensure that the non-emission section exists between the light emitting sections, it is possible to achieve high-speed driving in the same frequency frame. to provide effectiveness.

FIG. 12 shows the process of a method of driving the organic light emitting display device 100 according to the present embodiments.

Referring to FIG. 12, the organic light emitting display device 100 according to the present embodiments turns on the second transistor TR2 before the first transistor TR1 disposed in the subpixel turns on in the image frame section. -Turn it on (S1200).

The second transistor TR2 is turned on and the first transistor TR1 remains turned off for a certain period of time, allowing a non-emission section to exist within the image frame section.

After a certain period of time has elapsed, the first transistor TR1 is turned on while the second transistor TR2 is turned on (S1210).

As the first transistor TR1 is turned on, the data voltage is applied to the first node N1 of the driving transistor DRT.

Then, the first transistor TR1 and the second transistor TR2 are turned off (S1220) so that the organic light emitting diode (OLED) emits light according to the gradation of the applied data voltage (Vdata).

According to the present embodiments, a sense signal (Sense) is applied before the scan signal (Scan) is applied in one image frame section, so that a non-emission section can be created before the light emission section of the image frame section.

At this time, the sense signals (Sense) applied to each gate line (GL) are overlapped and output, so that a sufficient non-emission section can be created.

By dividing the video frame section into a non-light-emitting section and a light-emitting section for a certain period of time, it is possible to provide the same effect as if video frames according to the non-light-emitting section are inserted into one video frame section.

By providing an effect like inserting a video frame within one video frame section, it provides an effect like high-speed operation without increasing the frame frequency, improving video response time and image quality.

The above description is merely an illustrative explanation of the technical idea of the present invention, and various modifications and variations will be possible to those skilled in the art without departing from the essential characteristics of the present invention. In addition, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but rather to explain it, and therefore the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted in accordance with the claims below, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of rights of the present invention.

100: Organic light emitting display device 110: Organic light emitting display panel
120: Gate driver 121: Scan signal output unit
122: sense signal output unit 130: data driver
140: controller

Claims (14)

An organic light emitting display panel having a plurality of gate lines and a plurality of data lines and a plurality of subpixels defined in an area where the gate lines and the data lines intersect; and
A gate driver driving the plurality of gate lines disposed on the organic light emitting display panel,
Each of the plurality of subpixels is,
organic light emitting diode;
A driving transistor that drives the organic light emitting diode;
a first transistor connected between the first node of the driving transistor and the data line;
a second transistor connected between a second node of the driving transistor and a reference voltage line; and
Includes a storage capacitor connected between the first node and the second node of the driving transistor,
The second transistor is turned on before the first transistor is turned on in the video frame section and is turned off when the first transistor is turned off.
According to paragraph 1,
The video frame section is,
A first section in which the second transistor is turned on when the first transistor is off, a second section in which the first transistor is turned on while the second transistor is on, and the first transistor and An organic light emitting display device comprising a third section in which the second transistor is turned off.
According to paragraph 2,
The organic light emitting diode,
An organic light emitting display device that does not emit light in the first section and the second section and emits light in the third section.
According to paragraph 2,
The organic light emitting display device wherein the sum of the lengths of the first section and the second section is less than or equal to the length of the third section.
According to paragraph 1,
The gate driver is,
In the video frame section, a second scan signal that turns on the second transistor included in the plurality of subpixels is sequentially output, and when a preset time elapses while the second transistor is turned on, the An organic light emitting display device that sequentially outputs a first scan signal that turns on the first transistor included in a plurality of subpixels.
According to clause 5,
The gate driver is,
An organic light emitting display device that outputs the second scan signals so that sections in which the second scan signals sequentially output to the second transistors included in different subpixels overlap each other.
According to clause 5,
The gate driver is,
An organic light emitting display device that outputs the first scan signal so that the first scan signal changes from high level to low level when the second scan signal changes from high level to low level.
According to clause 5,
The gate driver is,
An organic light emitting display device that increases the output speed of the first scan signal in proportion to the ratio that the preset time occupies in the image frame section.
a scan signal output unit that controls driving of a first transistor that controls application of a data voltage to a first node of a driving transistor included in a subpixel in an image frame section; and
A sense signal output unit for controlling the driving of a second transistor that controls application of a reference voltage to a second node of the driving transistor,
The sense signal output unit,
A gate driver that outputs a second scan signal for driving the second transistor before the first scan signal for driving the first transistor is output by the scan signal output unit.
According to clause 9,
The sense signal output unit,
A gate driver that outputs the second scan signal so that sections in which the second scan signal output to the second transistor included in different subpixels are high level overlap each other.
According to clause 9,
The scan signal output unit,
When the second scan signal is output and a preset time elapses, the first scan signal is output, and when the second scan signal changes from high level to low level, the first scan signal changes from high level to low level. A gate driver that outputs the first scan signal to be changed.
organic light emitting diode;
A driving transistor that drives the organic light emitting diode;
a first transistor connected between a first node of the driving transistor and a data line;
a storage capacitor connected between the first node and the second node of the driving transistor; and
It is connected between the second node of the driving transistor and the reference voltage line, and is turned on before the first transistor is turned on in the video frame section and turned off when the first transistor is turned off. second transistor
A subpixel containing .
According to clause 12,
The video frame section is,
A first section in which the second transistor is turned on when the first transistor is off, a second section in which the first transistor is turned on while the second transistor is on, and the first transistor and A subpixel including a third section in which the second transistor is turned off.
According to clause 13,
The organic light emitting diode,
A subpixel that does not emit light in the first section and the second section and emits light in the third section.

Images