KR102565967B1 - Sensing apparatus, panel driving apparatus and display device - Google Patents

Abstract

The present invention provides a technology for improving the accuracy of feature sensing for a pixel by sensing a capacitance characteristic value of a sensing line using a capacitor or a current source and reflecting the capacitance characteristic value in pixel characteristic sensing.

Description

Sensing device, panel driving device and display device {SENSING APPARATUS, PANEL DRIVING APPARATUS AND DISPLAY DEVICE}

The present invention relates to a technology for driving a display device.

A display device includes a source driver for driving pixels arranged on a panel.

The source driver controls the brightness of each pixel by determining a data voltage according to image data and supplying the data voltage to the pixels.

Meanwhile, even if the same data voltage is supplied, the brightness of each pixel may vary according to the characteristics of the pixels. For example, a pixel includes a driving transistor, and when the threshold voltage of the driving transistor changes, the brightness of the pixel changes even when the same data voltage is supplied. If the source driver does not consider the change in the characteristics of these pixels, the pixels are driven at an undesirable brightness and the image quality deteriorates.

Specifically, the characteristics of the pixels change according to time or the surrounding environment. At this time, if the source driver supplies the data voltage without considering the changed characteristics of the pixels, a problem of deterioration in image quality (for example, a problem such as screen stains) occurs.

In order to improve such a problem of deterioration in image quality, a display device may include a sensing device that senses characteristics of pixels.

The sensing device may receive a sensing signal for each pixel through a sensing line connected to each pixel. Then, the sensing device converts the sensing signal into sensing data and transmits it to the timing controller, and the timing controller grasps the characteristics of each pixel through the sensing data. Further, the timing controller can improve the problem of deterioration in image quality due to pixel deviation by compensating for image data by reflecting characteristics of each pixel.

On the other hand, if the sensing device inaccurately senses the pixel characteristics, the effectiveness of such image data compensation is also lowered. For example, when pixels without characteristic variation are sensed as having characteristic variation due to inaccurate sensing of the sensing device, erroneous image data compensation may occur and image quality may deteriorate.

The sensing device senses each pixel through a sensing line connected to each pixel. If there is a deviation in the sensing line, the sensing device may inaccurately sense the characteristics of each pixel. For example, a sensing line has a line impedance, and this line impedance affects a signal reception value in the sensing device. However, when there is a deviation in the line impedance for each sensing line, the sensing device may inaccurately sense the characteristics of each pixel. As a specific example, the magnitude of signal delay varies depending on the resistance value or capacitance included in the line impedance. If the line impedance is different for each sensing line, the sensing device can sense pixels with the same characteristic with different characteristic values. .

Against this background, an object of the present invention, in one aspect, is to provide a technique for improving the accuracy of characteristic sensing for a pixel. In another aspect, an object of the present invention is to provide a technique for sensing a characteristic of a pixel by reflecting a deviation of a sensing line. In another aspect, an object of the present invention is to provide a technique for measuring a deviation of a sensing line or a characteristic of a sensing line.

In order to achieve the above object, in one aspect, the present invention provides a sensing device for sensing characteristics of pixels in a panel in which a plurality of pixels are disposed and a plurality of sensing lines connected to the pixels are disposed.

Such a sensing device includes a sensing unit and a control unit, and the sensing unit receives a sensing signal for a pixel through a sensing line and converts the sensing signal to generate pixel sensing data. The control unit controls such that a first voltage is supplied to the sensing line at a first time point, a first current source or a first capacitor is connected to the sensing line at a second time point, and a voltage of the sensing line is measured at a third time point.

In another aspect, the present invention provides a device for driving a panel in which a plurality of pixels are disposed and a plurality of data lines and a plurality of sensing lines connected to the pixels are disposed.

The panel driving device includes a data driving circuit, a sensing circuit, and a data processing circuit. The data driving circuit converts image data into data voltage and supplies it to the data line. Further, the sensing circuit receives a sensing signal for the pixel through the sensing line, converts the sensing signal to generate pixel sensing data, supplies a first voltage to the sensing line at a first time point, and supplies a first voltage to the sensing line at a second time point. A first current source or a first capacitor is connected, and a voltage of the sensing line is measured at a third point in time to generate line sensing data. And, the data processing circuit compensates for the image data using the pixel sensing data and the line sensing data.

In another aspect, the present invention provides a display device including a panel, one first current source or one first capacitor, and a plurality of source driver integrated circuits (ICs).

In such a display device, each source driver IC converts image data into data voltage and supplies it to a data line, receives a sensing signal for a pixel through a sensing line, converts the sensing signal to generate pixel sensing data, At one point in time, a first voltage is supplied to the sensing line, and at another point in time, the one first current source or the one first capacitor is connected to the sensing line, and at another point in time, the voltage of the sensing line is measured to obtain line sensing data. generate

The display device may further include one first voltage source supplying the first voltage, and the source driver IC connects the sensing line to the one first voltage source at a point in time.

As described above, according to the present invention, the deviation of the sensing line or the characteristic of the sensing line can be measured. Further, according to the present invention, it is possible to sense the characteristic of a pixel by reflecting the deviation of the sensing line. In addition, according to the present invention, it is possible to increase the accuracy of feature sensing for pixels and improve the image quality of a display device.

1 is a configuration diagram of a display device according to an exemplary embodiment.
FIG. 2 is a diagram illustrating a pixel structure of each pixel of FIG. 1 and voltages input and output from a data driving circuit and a sensing circuit to a pixel.
3 is a diagram illustrating a difference in measured values of a sensing signal according to a difference in capacitance of a sensing line.
4 is a diagram illustrating a configuration of a sensing circuit and an example of a peripheral circuit thereof according to an exemplary embodiment.
5 is a flowchart of a control method of a sensing circuit according to an exemplary embodiment.
6 is a diagram illustrating a configuration of a sensing circuit and an example of a peripheral circuit thereof according to another embodiment.
7 is a flowchart of a control method of a sensing circuit according to another embodiment.
8 is a diagram for explaining contents related to characteristic values of pixels.
9 is a first exemplary diagram illustrating an embodiment in which a data driving circuit and a sensing circuit are implemented with a plurality of source driver ICs.
10 is a second exemplary diagram illustrating an embodiment in which a data driving circuit and a sensing circuit are implemented with a plurality of source driver ICs.

Hereinafter, some embodiments of the present invention will be described in detail through exemplary drawings. In adding reference numerals to components of each drawing, it should be noted that the same components have the same numerals as much as possible even if they are displayed on different drawings. In addition, in 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 will be omitted.

Also, terms such as first, second, A, B, (a), and (b) may be used in describing the components of the present invention. These terms are only used to distinguish the component from other components, and the nature, order, or order of the corresponding component is not limited by the term. When an element is described as being “connected,” “coupled to,” or “connected” to another element, that element is directly connected or connectable to the other element, but there is another element between the elements. It will be understood that elements may be “connected”, “coupled” or “connected”.

1 is a configuration diagram of a display device according to an exemplary embodiment.

Referring to FIG. 1 , a display device 100 may include a panel 110 and devices 120 , 130 , 140 , and 150 that drive the panel 110 .

A plurality of data lines DL, a plurality of gate lines GL, and a plurality of sensing lines SL may be disposed on the panel 110, and a plurality of pixels P may be disposed.

The panel driving device may include a data driving circuit 120, a sensing circuit 130, a gate driving circuit 140, and a data processing circuit 150.

In the panel driving device, the gate driving circuit 140 may supply a scan signal of a turn-on voltage or a turn-off voltage to the gate line GL. When the scan signal of the turn-on voltage is supplied to the pixel P, the corresponding pixel P is connected to the data line DL, and when the scan signal of the turn-off voltage is supplied to the pixel P, the corresponding pixel P and the data line ( DL) is disconnected.

In the panel driving device, the data driving circuit 120 supplies the data voltage to the data line DL. The data voltage supplied to the data line DL is transferred to the pixel P connected to the data line DL according to the scan signal.

In the panel driving device, the sensing circuit 130 receives a sensing signal (eg, voltage, current, etc.) formed in each pixel P. The sensing circuit 130 may be connected to each pixel P according to a scan signal or may be connected to each pixel P according to a separate sensing signal. At this time, the sensing signal may be generated by the gate driving circuit 140 .

In the panel driving device, the data processing circuit 150 may supply various control signals to the gate driving circuit 140 and the data driving circuit 120 . The data processing circuit 150 may generate a gate control signal GCS for starting a scan according to timing implemented in each frame and transmit it to the gate driving circuit 140 . In addition, the data processing circuit 150 may output image data RGB obtained by converting image data input from the outside to suit the data signal format used by the data driving circuit 120 to the data driving circuit 120 . Also, the data processing circuit 150 may transmit a data control signal DCS for controlling the data driving circuit 120 to supply data voltages to each pixel P according to each timing.

The data processing circuit 150 may compensate and transmit the image data RGB according to the characteristics of the pixel P. At this time, the data processing circuit 150 may receive the sensing data SENSE_DATA from the sensing circuit 130 . The sensing data SENSE_DATA may include measurement values for characteristics of the pixel P. In addition, the sensing data SENSE_DATA may include a measurement value of the sensing line SL.

Meanwhile, the data driving circuit 120 may be called a source driver. Also, the gate driving circuit 140 may be called a gate driver. Also, the data processing circuit 150 may be called a timing controller. The data driving circuit 120 and the sensing circuit 130 are included in one integrated circuit and may be called a source driver IC (Integrated Circuit). In addition, the data driving circuit 120, the sensing circuit 130, and the data processing circuit 150 are included in one integrated circuit and may be called an integrated IC. Although the present embodiment is not limited to these names, descriptions of some commonly known components such as a source driver, a gate driver, a timing controller, and the like are omitted in the description of the following embodiments. Therefore, it should be considered that some of these configurations are omitted in the understanding of the embodiment.

Meanwhile, the panel 110 may be an organic light emitting display panel. In this case, the pixels P disposed on the panel 110 may include organic light emitting diodes (OLEDs) and one or more transistors. The characteristics of organic light emitting diodes (OLEDs) and transistors included in each pixel P may change according to time or surrounding environment. The sensing circuit 130 according to an embodiment may sense the characteristics of these components included in each pixel P and transmit the sensed characteristics to the data processing circuit 150 .

FIG. 2 is a diagram illustrating a pixel structure of each pixel of FIG. 1 and voltages input and output from a data driving circuit and a sensing circuit to a pixel.

Referring to FIG. 2 , the pixel P may include an organic light emitting diode (OLED), a driving transistor (DRT), a switching transistor (SWT), a sensing transistor (SENT), and a storage capacitor (Cstg).

An organic light emitting diode (OLED) may include an anode electrode, an organic layer, and a cathode electrode. Under the control of the driving transistor DRT, the anode electrode is connected to the driving voltage EVDD and the cathode electrode is connected to the ground voltage EVSS to emit light.

The driving transistor DRT may control brightness of the organic light emitting diode OLED by controlling a driving current supplied to the organic light emitting diode OLED.

The first node N1 of the driving transistor DRT may be electrically connected to the anode electrode of the organic light emitting diode OLED, and may be a source node or a drain node. The second node N2 of the driving transistor DRT may be electrically connected to a source node or a drain node of the switching transistor SWT and may be a gate node. The third node N3 of the driving transistor DRT may be electrically connected to the driving voltage line DVL supplying the driving voltage EVDD, and may be a drain node or a source node.

The switching transistor SWT may be electrically connected between the data line DL and the second node N2 of the driving transistor DRT, and may be turned on by receiving a scan signal through the gate line GL.

When the switching transistor SWT is turned on, the data voltage Vdata supplied from the data driving circuit 120 through the data line DL is transferred to the second node N2 of the driving transistor DRT.

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

The storage capacitor Cstg may be a parasitic capacitor existing between the first node N1 and the second node N2 of the driving transistor DRT, or an external capacitor intentionally designed outside the driving transistor DRT. can

The sensing transistor SENT connects the first node N1 of the driving transistor DRT to the sensing line S, and the sensing line SL transmits a characteristic value of the first node N1 - for example, voltage. It can be transmitted to the sensing circuit 130.

Also, the sensing circuit 130 measures the characteristics of the pixel P using the sensing signal Vsense transmitted through the sensing line SL.

When the voltage of the first node N1 is measured, the threshold voltage and mobility of the driving transistor DRT can be determined. In addition, when the voltage of the first node N1 is measured, the degree of deterioration of the organic light emitting diode (OLED), such as the parasitic capacitance of the organic light emitting diode (OLED), can be grasped.

The sensing circuit 130 may measure the voltage of the first node N1 and transmit the measured value to the data processing circuit (see 150 in FIG. 1 ). In addition, the data processing circuit (see 150 in FIG. 1 ) can determine the characteristics of each pixel P by analyzing the voltage of the first node N1 .

Meanwhile, the sensing signal Vsense transmitted from the pixel P is transmitted to the sensing circuit 130 through the sensing line SL. At this time, the sensing signal Vsense received by the sensing circuit 130 is the sensing line ( SL) can be affected by the capacitance (CSL).

3 is a diagram illustrating a difference in measured values of a sensing signal according to a difference in capacitance of a sensing line.

The signal delay of the sensing signal varies according to the capacitance of the sensing line. When the sensing circuit measures the sensing signal at the same time point (T1) for the sensing lines having different capacitances (CSLa, CSLb), the difference in signal delay Therefore, even if the characteristics of the pixels connected to the two sensing lines are the same, values of the sensing signals (Vsense_a and Vsense_b) measured may be different as shown in FIG. 3 .

Vpixel is the voltage formed in the pixel, and R is the line resistance from the pixel to the sensing circuit.

The sensing signal Vsense measured by the sensing circuit follows Equation 1. When the voltage (Vpixel) formed in the pixel is the same and only the capacitance of the sensing line is different between CSLa and CSLb as shown in FIG. 3, the difference in the measured sensing signal (Vsense) is calculated as in Equation 2

Since two pixels having the same characteristics as shown in Equation 2 can be sensed at different values according to the capacitance of the sensing line, the display device according to an exemplary embodiment measures the capacitance of the sensing line and determines the capacitance of the sensing line. Sensing signals for pixels may be compensated.

The display device may measure or calculate a value corresponding to the capacitance of the sensing line without directly measuring the capacitance of the sensing line. Hereinafter, for convenience of description, a value corresponding to capacitance is referred to as a capacitance characteristic value. The capacitance characteristic value may be a function value corresponding one-to-one to the capacitance of the sensing line. For example, the capacitance characteristic value may be the capacitance value itself, may be a value obtained by multiplying the capacitance by a constant proportional constant, or may be a value in inverse proportion to the capacitance.

4 is a diagram illustrating a configuration of a sensing circuit and an example of a peripheral circuit thereof according to an exemplary embodiment.

Referring to FIG. 4 , the sensing circuit 130 may include a sensing unit 410 and a control unit 420 .

The sensing unit 410 may generate digital data by converting signals received from the sensing lines SL1, SL2, ..., SLn.

The sensing unit 410 may receive sensing signals corresponding to characteristics of pixels from the sensing lines SL1 , SL2 , ..., SLn. Also, the sensing unit 410 may generate pixel sensing data by converting the sensing signal.

The sensing unit 410 may include a sample and hold (S/H) to receive a sensing signal that is an analog signal. Also, the sensing unit 410 may further include an analog digital converter (ADC) that converts the sampled analog signal into a digital signal.

Although not shown in the drawings, the sensing circuit 130 may further include a memory for storing the converted digital data, and transfer the stored digital data to an external device (for example, a data processing circuit (see 150 in FIG. 1)). It may further include a communication unit for transmission.

The sensing unit 410 may include a plurality of channels to sense the plurality of sensing lines SL1, SL2, ..., SLn in a short time or simultaneously. In addition, each channel may include a sample-and-hold (S/H) and/or an analog-to-digital converter (ADC).

The sensing unit 410 receives sensing signals from the sensing lines SL1, SL2, ..., SLn using such a sample-and-hold (S/H), analog-to-digital converter (ADC), and converts the sensing signals to Pixel sensing data may be generated.

On the other hand, the sensing unit 410 uses circuits (eg, sample and hold (S/H), analog-to-digital converter (ADC), etc.) used to generate pixel-sensed data to sense lines SL1, SL2, ..., line sensing data corresponding to the capacitance characteristic values of SLn) may also be generated.

A first voltage V1 may be supplied to the sensing circuit 130 . Also, a first capacitor CCAL may be connected to the sensing circuit 130 . The control unit 420 applies the first voltage V1 and the first capacitor CCAL to the capacitances CSL1, CSL2, ..., CSLn of the sensing lines SL1, SL2, ..., SLn. The corresponding capacitance characteristic value may be controlled to be measured by the sensing unit 410 .

The controller 420 first supplies the first voltage V1 to a selected sensing line among the plurality of sensing lines SL1 , SL2 , ..., SLn at a first point in time. Through this process, the corresponding sensing line is charged with the first voltage V1.

Also, the controller 420 connects the first capacitor CCAL to the corresponding sensing line at a second time point. Through this process, the charge charged in the corresponding sensing line is shared with the first capacitor CCAL.

Then, the controller 420 measures the capacitance characteristic value of the corresponding sensing line by measuring the voltage of the corresponding sensing line at a third time point.

On the other hand, the control unit 420 supplies the second voltage V2 to reset the charge of the first capacitor CCAL to a constant value at a fourth time point corresponding to before the second time point, and supplies the second voltage V2 before the second time point. The supply of voltage V2 can be stopped.

Vx is the voltage of the sensing line measured through the sensing unit 410 at the third point in time, and CSL is the capacitance of the sensing line to be measured.

Referring to Equation 3, the voltage (Vx) of the sensing line measured at the third point is the first voltage (V1), the second voltage (V2), the first capacitor (CCAL) and the capacitance (CSL) of the sensing line Since it is a function of Vx, V1, V2 and CCAL values, solving Equation 3 again can calculate the capacitance (CSL) of the sensing line.

Equation 4 calculates the capacitance CSL of the sensing line with the sensing line voltage Vx measured at the third point, the capacitance of the first capacitor CCAL, the first voltage V1 and the second voltage V2. represents counting.

The sensing circuit 130 converts the sensing line voltage (Vx) measured at the third point into digital data to generate line sensing data, and the display device calculates the capacitance (CSL) of the sensing line using the line sensing data. It can be calculated or the capacitance characteristic value of the sensing line can be calculated.

Meanwhile, referring to FIG. 4 , a plurality of switch circuits (SW11 to SW1n, SW21 to SW2n, and SW3) are disposed in the sensing circuit 130, and the sensing circuit 130 includes a plurality of switch circuits (SW11 to SW1n, SW21). Capacitance characteristic values for each of the sensing lines SL1, SL2, ..., SLn may be sensed using ~ SW2n and SW3.

Referring to FIG. 4 , the terminal to which the first voltage V1 is supplied and the sensing lines SL1, SL2, ..., SLn may be connected by first switch circuits SW11 to SW1n. The controller 420 connects the terminal to which the first voltage V1 is supplied and the sensing lines SL1, SL2, ..., SLn using the first switch circuits SW11 to SW1n at a first time point.

The first voltage V1 may be supplied to one sensing line as one of the plurality of first switch circuits SW11 to SW1n is turned on and the remaining first switch circuits are turned off. there is. Depending on embodiments, one first switch circuit may connect a plurality of sensing lines to the first voltage source.

A terminal to which the first capacitor CCAL is connected and the sensing lines SL1, SL2, ..., SLn may be connected by second switch circuits SW21, SW22, ..., SW2n. The control unit 420 connects the first capacitor CCAL and the sensing lines SL1, SL2, ..., SLn using the second switch circuits SW21, SW22, ..., SW2n at the second time point. . Prior to the second point in time, the supply of the first voltage V1 to the sensing line is released.

As one of the plurality of second switch circuits SW21 to SW2n is turned on and the other second switch circuits are turned off, one sensing line and the first capacitor CCAL may be connected. . Depending on embodiments, one second switch circuit may connect a plurality of sensing lines to the first capacitor CCAL.

The third switch circuit SW3 may connect a terminal to which the second voltage V2 is supplied and the first capacitor CCAL. The control unit 420 may supply the second voltage V2 to the first capacitor CCAL by using the third switch circuit SW3 at a fourth time point prior to the second time point.

5 is a flowchart of a control method of a sensing circuit according to an exemplary embodiment.

Referring to FIG. 5 , the sensing circuit supplies a first voltage to a sensing line to be measured and supplies a second voltage to a first capacitor (S502). At this time, the sensing line and the first capacitor are separated from each other.

Then, the sensing circuit releases the supply of the first voltage to the sensing line and the supply of the second voltage to the first capacitor (S504). At this time, the sensing line is charged with the first voltage, and the first capacitor is charged with the second voltage.

Then, the sensing circuit connects the sensing line and the first capacitor (S506). Through this connection, the charge charged in the capacitance of the sensing line and the charge charged in the first capacitor are shared with each other.

Then, the sensing circuit measures the voltage of the sensing line (S508), converts the measured voltage of the sensing line to generate line sensing data (S510), and transmits the pixel sensing data and/or the line sensing data to the data processing circuit. Do (S512). Such pixel sensing data and line sensing data are used to calculate characteristic values of pixels in a data processing circuit.

6 is a diagram illustrating a configuration of a sensing circuit and an example of a peripheral circuit thereof according to another embodiment.

Referring to FIG. 6 , the sensing circuit 630 may include a sensing unit 410, a control unit 420, and a plurality of switch circuits SW11 to SW1n and SW21 to SW2n.

A first voltage V1 may be supplied to the sensing circuit 630 . Also, the first current source ICAL may be connected to the sensing circuit 630 . The controller 420 applies the first voltage V1 and the first current source ICAL to the capacitances CSL1, CSL2, ..., CSLn of the sensing lines SL1, SL2, ..., SLn. The corresponding capacitance characteristic value may be controlled to be measured by the sensing unit 410 .

The controller 420 first supplies the first voltage V1 to a selected sensing line among the plurality of sensing lines SL1 , SL2 , ..., SLn at a first point in time. Through this process, the corresponding sensing line is charged with the first voltage V1.

Also, the controller 420 connects the first current source ICAL to the corresponding sensing line at a second time point. Through this process, the charge charged in the corresponding sensing line is discharged by the first current source ICAL. At this time, the controller 420 may connect the first current source ICAL to the sensing line only for a preset time.

Then, the controller 420 measures the capacitance characteristic value of the corresponding sensing line by measuring the voltage of the corresponding sensing line at a third time point.

Vx is the voltage of the sensing line measured through the sensing unit 410 at the third point in time, and CSL is the capacitance of the sensing line to be measured. Also, I1 is the amount of current discharged by the first current source ICAL, and ΔT is the time during which the sensing line is discharged with the current of I1.

Referring to Equation 5, the voltage (Vx) of the sensing line measured at the third point is a function of the first voltage (V1), the discharge current (I1), the discharge time (ΔT), and the capacitance (CSL) of the sensing line. Since the values of Vx, V1, I1 and ΔT can be known, the capacitance CSL of the sensing line can be calculated by solving Equation 5 again.

Equation 6 shows that the capacitance (CSL) of the sensing line is calculated with the sensing line voltage (Vx), the first voltage (V1), the discharge current (I1), and the discharge time (ΔT) measured at the third point in time.

The sensing circuit 630 converts the sensing line voltage Vx measured at the third point into digital data to generate line sensing data, and the display device calculates the capacitance CSL of the sensing line using the line sensing data. It can be calculated or the capacitance characteristic value of the sensing line can be calculated.

On the other hand, referring to FIG. 6, a plurality of switch circuits (SW11 to SW1n, SW21 to SW2n) are disposed in the sensing circuit 630, and the sensing circuit 630 includes a plurality of switch circuits (SW11 to SW1n, SW21 to SW2n). ) may be used to sense capacitance characteristic values for each of the sensing lines SL1, SL2, ..., SLn.

Referring to FIG. 6 , the terminal to which the first voltage V1 is supplied and the sensing lines SL1, SL2, ..., SLn may be connected by first switch circuits SW11 to SW1n. The controller 420 connects the terminal to which the first voltage V1 is supplied and the sensing lines SL1, SL2, ..., SLn using the first switch circuits SW11 to SW1n at a first time point.

The first voltage V1 may be supplied to one sensing line as one of the plurality of first switch circuits SW11 to SW1n is turned on and the remaining first switch circuits are turned off. there is. Depending on embodiments, one first switch circuit may connect a plurality of sensing lines to the first voltage source.

A terminal to which the first current source ICAL is connected and the sensing lines SL1, SL2, ..., SLn may be connected by second switch circuits SW21, SW22, ..., SW2n. The controller 420 connects the first current source ICAL and the sensing lines SL1, SL2, ..., SLn using the second switch circuits SW21, SW22, ..., SW2n at the second time point. . Prior to the second point in time, the supply of the first voltage V1 to the sensing line is released.

As one of the plurality of second switch circuits SW21 to SW2n is turned on and the other second switch circuits are turned off, one sensing line and the first current source ICAL may be connected. . Depending on embodiments, one second switch circuit may connect a plurality of sensing lines to the first current source ICAL.

7 is a flowchart of a control method of a sensing circuit according to another embodiment.

Referring to FIG. 7 , the sensing circuit supplies a first voltage to a sensing line to be measured (S702). At this time, the sensing line and the first current source are separated from each other.

Then, the sensing circuit releases the supply of the first voltage to the sensing line (S704). At this time, the sensing line is charged with the first voltage.

And, the sensing circuit connects the sensing line and the first current source (S706). Through this connection, the charge charged in the capacitance of the sensing line is discharged by the first current source.

Then, the sensing circuit measures the voltage of the sensing line (S708), converts the measured voltage of the sensing line to generate line sensing data (S710), and transmits the pixel sensing data and/or the line sensing data to the data processing circuit. Do (S712). Such pixel sensing data and line sensing data are used to calculate characteristic values of pixels in a data processing circuit.

Meanwhile, the data processing circuit may calculate characteristic values of pixels according to pixel sensing data and line sensing data received from the sensing circuit.

8 is a diagram for explaining contents related to characteristic values of pixels.

When the pixel P is connected to the sensing line SL and the driving voltage Vin is input to the pixel P, the pixel current Ipixel flows from the pixel P to the sensing line SL.

k is a mobility value of a driving transistor positioned in the pixel P, and Vth is a threshold voltage of the driving transistor.

When the pixel current Ipixel flows for a certain period of time T1, the capacitance CSL of the sensing line SL is charged with the pixel current Ipixel, and a voltage Vsense is formed in the sensing line SL. .

The sensing circuit senses the voltage Vsense formed on the sensing line SL, converts it into pixel sensing data, and transmits it to the data processing circuit. And, the data processing circuit calculates the characteristic value of the pixel P using the pixel sensing data and the line sensing data.

In Equation 9, Vsense is obtained through pixel sensing data, and CSL is obtained through line sensing data. And, Vin and T1 are variables to be controlled, and Vth is a known value or a value calculated by another method. The data processing circuit can accurately calculate the mobility (an example of a characteristic value) of the pixel P by combining the pixel sensing data and the line sensing data in this way.

When the sensing circuit uses the first capacitor-when configured as in the embodiment described with reference to FIG. 4, the data processing circuit stores the capacitance of the first capacitor or a value associated with the capacitance in advance, and A value corresponding to the capacitance (CSL) of each sensing line may be calculated according to a calculation formula (Equation 4) according to a charge sharing phenomenon that occurs when a capacitor is connected to a sensing line.

When the sensing circuit uses the first current source-when configured as in the embodiment described with reference to FIG. 6, the data processing circuit outputs a value associated with the amount of charge discharged by the first current source (e.g., discharge current and discharge time). ) is stored in advance, and a value corresponding to the capacitance (CSL) of each sensing line can be calculated according to a calculation formula (Equation 6) according to a discharge phenomenon that occurs when the first current source is connected to the sensing line.

Also, the data processing circuit may compensate image data using the characteristic values of the pixels P.

In Equation 10, the driving voltage Vin is a value corresponding to image data. The data processing circuit may compensate image data by calculating characteristic values (eg, mobility and threshold voltage) of the pixel P as in Equation 10 and reflecting them.

9 is a first exemplary diagram illustrating an embodiment in which a data driving circuit and a sensing circuit are implemented with a plurality of source driver ICs.

Referring to FIG. 9 , the data driving circuit and the sensing circuit may be implemented with a plurality of source driver ICs 920a, 920b, ..., 920n.

Each of the source driver ICs 920a, 920b, ..., 920n may drive and sense the pixels in the panel 110 by dividing them into blocks or groups. When the number of pixels is large or the panel 110 is formed wide, the plurality of source drivers 920a, 920b, ..., 920n may be divided into blocks or groups to drive or sense pixels.

Each of the source driver ICs 920a, 920b, ..., 920n may perform functions of a data driving circuit and a sensing circuit. As an example, each of the source driver ICs 920a, 920b, ..., 920n may convert image data into a data voltage and supply the converted data voltage to the data line DL. In addition, each of the source driver ICs 920a, 920b, ..., 920n may receive a sensing signal for the pixel P through the sensing line SL and convert the sensing signal to generate pixel sensing data. there is. In addition, each of the source driver ICs 920a, 920b, ..., 920n supplies a first voltage to the sensing line SL at one point in time and a first capacitor CCAL to the sensing line SL at another point in time. can be connected. In addition, each of the source driver ICs 920a, 920b, ..., 920n may generate line sensing data by measuring the voltage of the sensing line SL at another point in time.

Each source driver IC (920a, 920b, ..., 920n) can transmit and receive data to and from the data processing circuit 950, respectively. For example, each source driver IC (920a, 920b, ..., 920n) may transmit the generated pixel sensing data and line sensing data to the data processing circuit as sensing data SENSE_DATA. Also, each of the source driver ICs 920a, 920b, ..., 920n may receive the data driving control signal DCS and the image data RGB from the data processing circuit 950.

Each of the source driver ICs 920a, 920b, ..., 920n may measure the capacitance characteristic value of each sensing line SL by using charge sharing with the first capacitor CCAL. In this case, each of the source driver ICs 920a, 920b, ..., 920n may share one first capacitor CCAL. The capacitance characteristic value of each sensing line SL can be calculated according to the charge sharing relational expression with the first capacitor CCAL as shown in Equation 4. At this time, when there is an error in the capacitance of the first capacitor CCAL , there may be an error in the measured capacitance characteristic value.

On the other hand, when each source driver IC (920a, 920b, ..., 920n) shares one first capacitor (CCAL), even if there is an error in the first capacitor (CCAL), each sensing line (SL) Although there may be an error in the absolute value of the capacitance characteristic value, no deviation occurs in the relative value. Therefore, in the structure shown in FIG. 9, the display device 900, even if each of the source driver ICs 920a, 920b, ..., 920n divides blocks or groups to drive or sense pixels, the same as block dim. the problem won't happen.

Each of the source driver ICs 920a, 920b, ..., 920n may also share a first voltage source V1S supplying a first voltage and a second voltage source V2S supplying a second voltage. Through this, the display device 900 can also remove a sensing error for each block that occurs due to a difference in supply voltage.

10 is a second exemplary diagram illustrating an embodiment in which a data driving circuit and a sensing circuit are implemented with a plurality of source driver ICs.

Referring to FIG. 10 , the data driving circuit and the sensing circuit may be implemented with a plurality of source driver ICs 1020a, 1020b, ..., 1020n.

Each of the source driver ICs 1020a, 1020b, ..., 1020n may drive and sense the pixels in the panel 110 by dividing them into blocks or groups. When the number of pixels is large or the panel 110 is formed wide, the plurality of source drivers 1020a, 1020b, ..., 1020n may be divided into blocks or groups to drive or sense pixels.

Each source driver IC (1020a, 1020b, ..., 1020n) can send and receive data to and from the data processing circuit 1050, respectively. For example, each source driver IC (1020a, 1020b, ..., 1020n) may transmit the generated pixel sensing data and line sensing data to the data processing circuit as sensing data SENSE_DATA. Also, each of the source driver ICs 1020a, 1020b, ..., 1020n may receive the data driving control signal DCS and the image data RGB from the data processing circuit 1050.

Each of the source driver ICs 1020a, 1020b, ..., 1020n may measure a capacitance characteristic value of each sensing line SL according to a discharge phenomenon using the first current source ICAL. In this case, each of the source driver ICs 1020a, 1020b, ..., 1020n may share one first current source ICAL. The capacitance characteristic value of each sensing line SL can be calculated according to the discharge relational expression with the first current source ICAL as shown in Equation 6. At this time, when there is an error in the discharge current of the first current source ICAL , there may be an error in the measured capacitance characteristic value.

Meanwhile, when each source driver IC (1020a, 1020b, ..., 1020n) shares one first current source (ICAL), even if there is an error in the first current source (ICAL), each sensing line (SL) Although there may be an error in the absolute value of the capacitance characteristic value, no deviation occurs in the relative value. Therefore, in the structure shown in FIG. 10, the display device 1000 has the same block dim even if each of the source driver ICs 1020a, 1020b, ..., 1020n drives or senses pixels by dividing them into blocks or groups. the problem won't happen.

Each of the source driver ICs 1020a, 1020b, ..., 1020n may also share a first voltage source V1S supplying a first voltage. Through this, the display device 1000 can also remove a sensing error for each block that occurs due to a difference in supply voltage.

According to the embodiment described above, the deviation of the sensing line or the characteristic of the sensing line can be measured. And, according to this embodiment, it is possible to calculate a characteristic value for a pixel by reflecting the deviation of the sensing line. In addition, according to this embodiment, it is possible to increase the accuracy of feature sensing for pixels and improve the image quality of the display device.

Terms such as "comprise", "comprise" or "have" described above mean that the corresponding component may be inherent unless otherwise stated, and therefore do not exclude other components. It should be construed that it may further include other components. All terms, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs, unless defined otherwise. Commonly used terms, such as terms defined in a dictionary, should be interpreted as consistent with the meaning in the context of the related art, and unless explicitly defined in the present invention, they are not interpreted in an ideal or excessively formal meaning.

The above description is merely an example of the technical idea of the present invention, and various modifications and variations can be made to those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention, but to explain, and the scope of the technical spirit of the present invention is not limited by these embodiments. The protection scope of the present invention should be construed according to the following claims, and all technical ideas within the equivalent range should be construed as being included in the scope of the present invention.

Claims (14)

A sensing device for sensing characteristics of the pixels in a panel on which a plurality of pixels are disposed and a plurality of sensing lines connected to the pixels, respectively, are disposed,
a sensing unit configured to receive a sensing signal for the pixel through each of the sensing lines and convert the sensing signal to generate pixel sensing data for the pixel; and
A first voltage is supplied to the sensing line at a first time point, a first current source or a first capacitor is connected to the sensing line at a second time point, and a control unit for controlling the voltage of the sensing line to be measured at a third time point. ,
The sensing unit converts the voltage of the sensing line measured at the third point in time to generate line sensing data corresponding to a capacitance characteristic value of the sensing line. According to claim 1,
The control unit,
A sensing device that connects a first voltage source to the sensing line at the first time point, and disconnects the connection to the first voltage source before the second time point. According to claim 2,
The control unit,
A sensing device for controlling a connection between the first voltage source and the sensing line using a first switch circuit and controlling a connection between the first current source or the first capacitor and the sensing line using a second switch circuit. According to claim 1,
The control unit,
A sensing device for measuring the voltage of the sensing line using the sensing unit at the third time point. According to claim 4,
The sensing device wherein the pixel sensing data and the line sensing data are transmitted to a data processing device and used to calculate a characteristic value of each pixel. According to claim 1,
The control unit,
A sensing device that connects the first current source to the sensing line only for a preset time. According to claim 1,
The control unit,
The sensing device controls supply of the second voltage to the first capacitor at a fourth time point before the second time point, and controls supply of the second voltage to be stopped before the second time point. An apparatus for driving a panel in which a plurality of pixels are disposed and a plurality of data lines and a plurality of sensing lines respectively connected to the pixels are disposed,
a data driving circuit that converts image data into data voltages and supplies them to the data lines;
Receiving a sensing signal for the pixel through each sensing line, converting the sensing signal to generate pixel sensing data for the pixel, supplying a first voltage to the sensing line at a first point in time, and supplying a second voltage to the sensing line. a sensing circuit connecting a first current source or a first capacitor to the sensing line at a point in time and measuring a voltage of the sensing line at a third point in time to generate line sensing data corresponding to a capacitance characteristic value of the sensing line; and
A data processing circuit for compensating the image data using the pixel sensing data and the line sensing data.
Panel driving device including a. According to claim 8,
The data processing circuit,
A value associated with the capacitance of the first capacitor is stored in advance, and the capacitance of each sensing line is corresponded to according to a calculation formula based on a charge sharing phenomenon that occurs when the first capacitor is connected to the sensing line. Panel drive device that calculates the value to be According to claim 9,
The calculation formula according to the charge sharing phenomenon is a panel driving device according to the following formula.

CSL: capacitance of the sensing line, CCAL: capacitance of the first capacitor, Vx: voltage of the sensing line measured at the third point, V1: first voltage, V2: second voltage According to claim 8,
The data processing circuit,
A value associated with the amount of charge discharged by the first current source is stored in advance, and the capacitance of each sensing line is corresponded to according to a calculation formula according to a discharge phenomenon that occurs when the first current source is connected to the sensing line. Panel drive device that calculates the value to be According to claim 11,
The calculation formula according to the discharge phenomenon is a panel drive device according to the following formula.

CSL: capacitance of the sensing line, I1: discharge current of the first current source, ΔT: discharge time of the first current source, Vx: sensing line voltage measured at the third point, V1: first voltage a panel on which a plurality of pixels are disposed and a plurality of data lines and a plurality of sensing lines respectively connected to the pixels are disposed;
one first current source or one first capacitor; and
Converting image data into data voltages and supplying them to the data lines, receiving sensing signals for the pixels through the respective sensing lines, converting the sensing signals to generate pixel sensing data for the pixels, At one point in time, a first voltage is supplied to the sensing line, and at another point in time, the one first current source or the one first capacitor is connected to the sensing line, and at another point in time, the voltage of the sensing line is measured. Multiple source driver ICs (Integrated Circuit) that generate line sensing data corresponding to the capacitance characteristic value of the sensing line
A display device including a. According to claim 13,
Further comprising a first voltage source supplying the first voltage,
The source driver IC,
A display device connecting the sensing line and the one first voltage source at the point of time.

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