KR102660242B1 - Display device and its driving method - Google Patents

Abstract

An example of the present invention relates to a display device and a method of driving the same that can eliminate floating sensing voltage switching lines and S multiplexers and reduce the volume and manufacturing cost of a data driver. The data driver of the present invention uses the signals of the data voltage switching line that supplies the data voltage to generate an X signal that controls the connection of the sensing line to receive the sensing voltage. The display device and its driving method according to an example of the present invention can control the sensing section with a signal created by passing the control signals of two existing data line switching multiplexers through a negated logical product (NAND) gate. Accordingly, the number of pins can be reduced by eliminating all three pins (PINs) for conventional sensing control. Accordingly, there is a chip integration (CI) effect and a chip size reduction effect.

Description

Display device and driving method thereof {DISPLAY DEVICE AND ITS DRIVING METHOD}

One example of the present invention relates to a display device and a method of driving the same.

In the information society, many related technologies are being developed in the field of display devices for displaying visual information in images or images. A display device includes a display panel having a display area provided with pixels that display images, a non-display area disposed outside the display area that does not display images, a gate driver that inputs gate signals to the pixels, and a data voltage to the pixels. It includes a plurality of source drive integrated circuits (hereinafter referred to as “ICs”), and a timing controller that inputs signals to control the gate driver and the plurality of source drive ICs.

Source drive ICs are included in a data driver, and data voltage switching lines including switching elements are provided in the data driver to input data voltages from the source drive IC to pixels during a display period. During the display period, a display multiplexer (hereinafter referred to as “D multiplexer”) supplies signals to switching elements to supply data voltages to pixels.

Among display devices, the physical characteristics of each pixel are different, and there is a display device that senses the physical characteristics of the pixels using a sensing section between display sections. A representative example of such a display device is an Organic Light Emitting Diode (OLED) display device. The data driver generates sensing data using the sensing voltage sensed from the pixels in the sensing section and supplies the generated sensing data to the timing controller.

In a conventional data driver, sensing voltage switching lines including switching elements for each color of the pixel are provided to receive sensing voltage from the pixels during the sensing period. During the sensing period, a sensing multiplexer (hereinafter referred to as "S multiplexer") connected to each sensing voltage switching line supplies a signal to the switching elements associated with the pixels of the color to be sensed, thereby performing sensing from the pixels. It receives voltage, but does not supply signals to the switching elements for pixels of other colors. Accordingly, in the case of a general display device with RGB color pixels, the sensing voltage was supplied from the pixels during the sensing period using three S multiplexers and three sensing voltage switching lines.

However, in order to sense by color, separate sensing voltage switching lines are provided for each color of the pixel, and while sensing pixels of a specific color, the sensing voltage switching lines connected to pixels of other colors and the sensing voltage of the other color are used. S multiplexers connected to switching lines have a problem of being in a floating state. In addition, there is a problem that the volume and manufacturing cost of the data driver increase by providing a plurality of S multiplexers and sensing voltage switching lines in the data driver.

An example of the present invention is to provide a display device and a method of driving the same that can eliminate floating sensing voltage switching lines and S multiplexers and reduce the volume and manufacturing cost of a data driver.

A display device according to an example of the present invention includes a display panel provided with pixels that display images, a data driver that supplies data voltage to the pixels and receives a sensing voltage from the pixels, and a data driver control signal that is supplied to the data driver. , and includes a timing controller that receives sensing data based on the sensing voltage from the data driver. The data driver of the present invention uses the signals of the data voltage switching line that supplies the data voltage to generate an X signal that controls the connection of the sensing line to receive the sensing voltage.

A method of driving a display device according to an example of the present invention includes the steps of a data driver receiving a sensing voltage from pixels that display an image, a timing controller receiving sensing data based on the sensing voltage from the data driver, and providing data to the data driver. It includes supplying a driver control signal, and supplying a data voltage to the pixels by the data driver. The step in which the data driver of the present invention receives the sensing voltage from the pixels that display the image uses the signals of the data voltage switching line that supplies the data voltage, and uses the It includes the step of generating.

The display device and its driving method according to an example of the present invention reduce the number of lines by integrating the sensing control of pixels for each color into one signal from the existing three. The present invention can eliminate floating sensing voltage switching lines and S multiplexers, and reduce the volume and manufacturing cost of the data driver. In addition, there is an effect of reducing the size of the bezel by reducing the number of sensing control lines. Specifically, by reducing two lines, the width of the bezel can be reduced by about 0.3mm.

In addition, the display device and its driving method according to an example of the present invention can control the sensing section with a signal created by passing the control signals of two existing data line switching multiplexers through a negated logical product (NAND) gate. Accordingly, the number of pins can be reduced by eliminating all three pins (PINs) for conventional sensing control. Accordingly, there is a chip integration (CI) effect and a chip size reduction effect.

1 is a circuit diagram showing a conventional data driver.
Figure 2 is a block diagram of a display device according to an example of the present invention.
3 is a circuit diagram of a pixel according to an example of the present invention.
Figure 4 is a circuit diagram showing a data driver according to an example of the present invention.
Figure 5 is a circuit diagram showing a data driver and a pixel according to an example of the present invention.
Figure 6 is a waveform diagram showing signals within one sensing frame according to a method of driving a display device according to an example of the present invention.

The advantages and features of the present invention and methods for achieving them will become clear by referring to the embodiments described in detail below along with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and will be implemented in various different forms. The present embodiments only serve to ensure that the disclosure of the present invention is complete and that common knowledge in the technical field to which the present invention pertains is not limited. It is provided to fully inform those who have the scope of the invention, and the present invention is only defined by the scope of the claims.

The shapes, sizes, proportions, angles, numbers, etc. disclosed in the drawings for explaining embodiments of the present invention are illustrative, and the present invention is not limited to the matters shown. Like reference numerals refer to like elements throughout the specification. Additionally, in describing the present invention, if it is determined that a detailed description of related known technologies may unnecessarily obscure the gist of the present invention, the detailed description will be omitted.

When 'includes', 'has', 'consists of', etc. mentioned in this specification are used, other parts may be added unless 'only' is used. When a component is expressed in the singular, the plural is included unless specifically stated otherwise.

When interpreting a component, it is interpreted to include the margin of error even if there is no separate explicit description.

In the case of a description of a positional relationship, for example, if the positional relationship of two parts is described as 'on top', 'on the top', 'on the bottom', 'next to', etc., 'immediately' Alternatively, there may be one or more other parts placed between the two parts, unless 'directly' is used.

In the case of a description of a temporal relationship, for example, if a temporal relationship is described as 'after', 'successfully after', 'after', 'before', etc., 'immediately' or 'directly' Unless used, non-consecutive cases may also be included.

Although first, second, etc. are used to describe various components, these components are not limited by these terms. These terms are merely used to distinguish one component from another. Accordingly, the first component mentioned below may also be the second component within the technical spirit of the present invention.

“X-axis direction,” “Y-axis direction,” and “Z-axis direction” should not be interpreted as only geometrical relationships in which the relationship between each other is vertical, and should not be interpreted as a wider range within which the configuration of the present invention can function functionally. It can mean having direction.

The term “at least one” should be understood to include all possible combinations from one or more related items. For example, “at least one of the first, second, and third items” means each of the first, second, or third items, as well as two of the first, second, and third items. It can mean a combination of all items that can be presented from more than one.

Each feature of the various embodiments of the present invention can be combined or combined with each other partially or entirely, and various technical interconnections and operations are possible, and each embodiment can be implemented independently of each other or together in a related relationship. It may be possible.

Among display devices, the present invention includes a display device in which the physical characteristics of each pixel are different and the physical characteristics of the pixels are sensed using a sensing section between display sections. A representative example of such a display device is an Organic Light Emitting Diode (OLED) display device. Therefore, the following description will focus on the case where the display device according to an embodiment of the present invention is an organic light emitting display device.

Before explaining the embodiment of the present invention, the conventional data driver will be described, and the embodiment of the present invention will be described in detail focusing on the differences from the conventional data driver. 1 is a circuit diagram showing a conventional data driver.

A conventional data driver includes a plurality of channels (Ch_1 to Ch_4), a reference voltage line (Ref), reference voltage switching lines (REF_SW1, REF_SW2), sensing voltage switching lines (SMUX1 to SMUX3), and data voltage switching lines. Includes (D_SW1, D_SW2).

A plurality of channels (Ch_1 to Ch_4) are output terminals of a plurality of source drive integrated circuits (hereinafter referred to as “IC”) included in the data driver. Figure 1 shows only four channels among a plurality of channels (Ch_1 to Ch_4). Each channel (Ch_1 to Ch_4) outputs data voltages generated by the source drive IC.

The reference voltage line Ref is connected to sensing lines connected to each pixel. The reference voltage line (Ref) supplies the reference voltage (REF) to each sensing line in the display section. The reference voltage (REF) is a voltage that serves as a reference for size comparison with the sensing voltage sensed by the pixel. The reference voltage (REF) is supplied to all pixels at the same level. In the sensing section, the data driver receives sensing voltage from the sensing lines. Accordingly, the reference voltage line Ref is disconnected from the sensing lines in the sensing section.

The reference voltage switching lines (REF_SW1, REF_SW2) connect the reference voltage line (Ref) to each sensing line in the display section. Additionally, the reference voltage switching lines (REF_SW1, REF_SW2) block the connection between the reference voltage line (Ref) and the sensing lines in the sensing section. To this end, the reference voltage switching lines (REF_SW1, REF_SW2) are connected to the reference voltage line (Ref) and each of the sensing lines through a switching element. Switching elements may be implemented as transistors (for example, MOSFETs may be used). In this case, the reference voltage switching lines (REF_SW1 and REF_SW2) may be connected to the gate terminals of each switching element. Additionally, the reference voltage line Ref may be connected to the drain terminal of each switching element, and each sensing line may extend from the source terminal of each switching element.

Figure 1 illustrates the case of using two reference voltage switching lines (REF_SW1, REF_SW2). In this case, if the switching element of the first reference voltage switching line (REF_SW1) is turned on in a certain display section, the switching element of the second reference voltage switching line (REF_SW2) is turned on in the next display section. -You can turn it on. Accordingly, deterioration of the switching element can be prevented.

The sensing voltage switching lines (SMUX1 to SMUX3) are connected to the channels (Ch_1 to Ch_4) and each sensing line through a switching element. Switching elements may be implemented as transistors (for example, MOSFETs may be used). In this case, the sensing voltage switching lines (SMUX1 to SMUX3) may be connected to the gate terminal of each switching element. Additionally, the channels (Ch_1 to Ch_4) may be connected to the drain terminal of each switching element, and each sensing line may extend from the source terminal of each switching element.

The sensing voltage switching lines (SMUX1 to SMUX3) control the sensing voltages to be supplied to the channels (Ch_1 to Ch_4) of the color to be sensed in the sensing section. For example, when it is desired to sense the sensing voltages of red pixels, the switching elements in the sensing lines connected to the first and fourth channels (Ch_1, Ch_4) are turned on.

The data voltage switching lines (D_SW1, D_SW2) are connected to the channels (Ch_1 to Ch_4) and each data line through a switching element. Switching elements may be implemented as transistors (for example, MOSFETs may be used). In this case, the data voltage switching lines D_SW1 and D_SW2 may be connected to the gate terminals of each switching element. Additionally, the channels (Ch_1 to Ch_4) may be connected to the drain terminal of each switching element, and each data line may extend from the source terminal of each switching element.

The data voltage switching lines (D_SW1, D_SW2) control to supply data voltages to the data lines in the display period. For example, when data voltages are to be supplied to red pixels, switching elements in the data lines connected to the first and fourth channels (Ch_1 and Ch_4) are turned on.

Figure 1 illustrates the case of using two data voltage switching lines (D_SW1, D_SW2). In this case, when the switching device of the first data voltage switching line (D_SW1) is turned on in a certain display section, the switching device of the second reference voltage switching line (D_SW2) can be turned on in the next display section. . Accordingly, deterioration of the switching element can be prevented.

In the conventional data driver, sensing voltage switching lines (SMUX1 to SMUX3) are provided for each color of the pixel to receive sensing voltage from the pixels during the sensing period. During the sensing period, a sensing multiplexer (hereinafter referred to as "S multiplexer") connected to each sensing voltage switching line supplies a signal to the switching elements associated with the pixels of the color to be sensed, thereby performing sensing from the pixels. It receives voltage, but does not supply signals to the switching elements for pixels of other colors. Accordingly, in the case of a general display device with RGB color pixels, the sensing voltage was supplied from the pixels during the sensing period using three S multiplexers and three sensing voltage switching lines (SMUX1 to SMUX3).

However, in order to sense by color, separate sensing voltage switching lines (SMUX1 to SMUX3) are provided for each color of the pixel, and while sensing pixels of a specific color, the sensing voltage switching lines (SMUX1) connected to pixels of other colors are ~SMUX3) and the S multiplexers connected to the different color sensing voltage switching lines (SMUX1~SMUX3) have a problem of being in a floating state. In addition, there is a problem that the volume and manufacturing cost of the data driver increase by providing a plurality of S multiplexers and sensing voltage switching lines (SMUX1 to SMUX3) in the data driver.

Hereinafter, embodiments of the present invention will be described in detail. Figure 2 is a block diagram of a display device according to an example of the present invention.

A display device according to an embodiment of the present invention includes a display panel 100, a gate driver 110, a data driver 120, and a timing controller (T-CON) 130.

The display panel 100 includes a display area and a non-display area provided around the display area. The display area is an area where pixels (P) are provided to display an image. The display panel 100 is provided with gate lines (GL1 to GLp, p is a positive integer of 2 or more), data lines (DL1 to DLq, q is a positive integer of 2 or more), and sensing lines (SL1 to SLq). do. The data lines (DL1 to DLq) and the sensing lines (SL1 to SLq) may intersect the gate lines (GL1 to GLp). The data lines (DL1 to DLq) and the sensing lines (SL1 to SLq) may be parallel to each other. The display panel 100 may include a lower substrate on which pixels P are provided and an upper substrate that performs an encapsulation function. Each of the pixels P may be connected to one of the gate lines GL1 to GLp, one of the data lines DL1 to DLq, and one of the sensing lines SE1 to SEm. A detailed description of the pixels P will be described later in conjunction with FIGS. 3 to 5.

The gate driver 110 receives a gate control signal (GCS) from the timing controller 130. The gate driver 110 generates gate signals according to the gate control signal GCS and supplies them to the gate lines GL1 to GLp. The gate driver 110 according to an example of the present invention is provided as a GIP (Gate in Panel) circuit in a non-display area of the lower substrate. The GIP circuit is built into the non-display area of the lower substrate. For example, the GIP circuit may be provided in a non-display area on one side or the other side of the display area, or in a non-display area on both sides of the display area, but is not limited to this and can be provided in any non-display area that can supply a gate signal to the gate line. It is provided in a non-display area.

The data driver 120 receives digital video data (DATA) and a data driver control signal (DCS) supplied from the timing controller 130. The data driver 120 converts digital video data DATA into an analog data voltage according to the data driver control signal DCS and supplies it to the data lines DL1 to DLq. The data driver 120 may include a plurality of source drive integrated circuits (hereinafter referred to as “source drive IC”).

Each of the source drive ICs may be mounted on each of the flexible films. Each of the flexible films may be prepared as a chip on film (COF). The chip-on film may include a base film such as polyimide and a plurality of conductive lead wires provided on the base film. Each of the flexible films can bend or bend. Each of the flexible films may be attached to the lower substrate of the display panel 100 and a control printed circuit board (C-PCB). In particular, each of the flexible films can be attached to the lower substrate using the TAB (Tape Automated Bonding) method using an anisotropic conductive film (ACF), which allows the source drive ICs to connect data lines (DL1 to DLq). ) can be connected to.

The data driver 120 receives a sensing voltage from the sensing lines SL1 to SLq. Each pixel (P) supplies a sensing voltage reflecting its physical characteristics to the sensing lines. The data driver 120 receives sensing voltages during the sensing period. The data driver 120 generates sensing data (SD) using the supplied sensing voltages. The data driver 120 supplies sensing data (SD) to the timing controller 130.

The timing controller 130 is mounted on a control printed circuit board and receives digital video data (DATA) and timing synchronization signals (Timing Signal, TS) from an external system board. Here, the timing synchronization signals are a vertical sync signal (Vertical Sync Signal, Vsync) that defines one frame period, a horizontal sync signal (Horizontal Sync Signal (Hsync)) that defines one horizontal period, and a data enable signal that indicates whether data is valid. (Data Enable Signal, DE), and a dot clock (DCLK), which is a clock signal with a predetermined period. Additionally, the timing controller 130 receives sensing data (SD) from the data driver 120.

The timing controller 130 includes a gate driver control signal (GCS) for controlling the operation timing of the gate driver 110 based on the timing synchronization signals TS and a data driver control signal for controlling the data driver 120 ( DCS) is created. The timing controller 130 supplies a gate driver control signal (GCS) to the gate driver 110 and a data driver control signal (DCS) to the data driver 120. At this time, the timing controller 130 may compensate for differences in physical characteristics between pixels (P) by correcting the data driver control signal (DCS) using the sensing data (SD).

3 is a circuit diagram of a pixel P according to an example of the present invention. The pixel (P) according to an example of the present invention includes an organic light emitting diode (OLED), a driving transistor (DT), first to fifth transistors (T1 to T5), and a first capacitor (C1).

The anode electrode of the organic light-emitting diode (OLED) may be connected to the source terminal of the fourth transistor T4, and the cathode electrode may be connected to the low-potential voltage line (VSS) to which a low-potential voltage lower than the high-potential voltage is supplied. The organic light emitting diode (OLED) emits light according to the current supplied through the fourth transistor (T4).

More specifically, an organic light emitting diode (OLED) includes an anode electrode, a hole transporting layer, an organic light emitting layer, an electron transporting layer, and a cathode electrode. may include. In an organic light emitting diode (OLED), when voltage is applied to the anode and cathode electrodes, holes and electrons are moved to the organic light emitting layer through the hole transport layer and electron transport layer, respectively, and the holes and electrons combine with each other in the organic light emitting layer to emit light.

The gate terminal of the driving transistor (DT) is connected to the drain terminal of the second transistor (T2) and the first capacitor (C1). The drain terminal of the driving transistor (DT) is connected to a high-potential voltage line (VDD) to which a high-potential voltage is supplied. The source terminal of the driving transistor DT is connected to the source terminal of the second transistor T2 and the drain terminal of the fourth transistor T4. The driving transistor DT is turned on by receiving the data voltage VDATA stored in the first capacitor C1 and supplies current to the fourth transistor T4.

The gate terminal of the first transistor (T1) receives the first gate signal (G1). The drain terminal of the first transistor (T1) is supplied with the data voltage (VDATA). The source terminal of the first transistor (T1) is connected to the first capacitor (C1). The first transistor T1 is turned on by the first gate signal G1 and stores the data voltage VDATA in the first capacitor C1.

The gate terminal of the second transistor (T2) receives the second gate signal (G2). The drain terminal of the second transistor T2 is connected to the gate terminal of the driving transistor TD and the first capacitor C1. The source terminal of the second transistor T2 is connected to the source terminal of the driving transistor TD and the drain terminal of the fourth transistor T4. The second transistor T2 is turned on by the second gate signal G2 and controls the current flowing in the driving transistor TD by controlling the voltage difference between the gate terminal and the source terminal of the driving transistor TD.

The gate terminal of the third transistor T3 receives the light emission signal EM. The drain terminal of the third transistor T3 is connected to the source terminal of the first transistor T1 and the first capacitor C1. The source terminal of the third transistor (T3) is supplied with the reference voltage (Vref). The third transistor T3 is turned on by the emission signal EM and stores the reference voltage Vref in the first capacitor C1.

The gate terminal of the fourth transistor (T4) receives the light emission signal (EM). The drain terminal of the fourth transistor (T4) is connected to the source terminal of the driving transistor (TD). The source terminal of the fourth transistor (T4) is connected to the anode electrode of the organic light emitting diode (OLED). The fourth transistor T4 is turned on by the light emission signal EM and supplies current to the organic light emitting diode (OLED).

The gate terminal of the fifth transistor T5 receives the second gate signal G2. The drain terminal of the fifth transistor (T5) is connected to the anode electrode of the organic light-emitting diode (OLED). The source terminal of the fifth transistor (T5) is connected to the reference voltage (Vref) line. The fifth transistor T5 is turned on by the second gate signal G2 and supplies the sensing voltage sensed by the organic light emitting diode (OLED) to the reference voltage (Vref) line.

The first capacitor C1 is connected between the source terminal of the first transistor T1 and the gate terminal of the driving transistor TD. The first capacitor C1 turns on the driving transistor TD using the data voltage VDATA supplied from the first transistor T1.

When driving the pixel (P) in this way, the data voltage (VDATA) and the reference voltage (Vref) must be supplied, and the sensing voltage must be supplied. Figure 4 is a circuit diagram showing a data driver according to an example of the present invention. Figure 5 is a circuit diagram showing a data driver and a pixel (P) according to an example of the present invention.

The data driver according to an example of the present invention includes a plurality of channels (Ch_1 to Ch_4), a reference voltage line (Ref), reference voltage switching lines (REF_SW1, REF_SW2), an X signal line (X), and a data voltage switching line. Includes (D_SW1, D_SW2). In the data driver according to an example of the present invention, a plurality of channels (Ch_1 to Ch_4), a reference voltage line (Ref), reference voltage switching lines (REF_SW1, REF_SW2), and data voltage switching lines (D_SW1, D_SW2) Since the configuration and function of is the same as that of the conventional data driver described in FIG. 1, detailed description thereof will be omitted.

The X signal line (X) is connected to the channels (Ch_1 to Ch_4) and each sensing line through a switching element. Switching elements may be implemented as transistors (for example, MOSFETs may be used). In this case, the X signal line (X) may be connected to the gate terminal of each switching element. Additionally, the channels (Ch_1 to Ch_4) may be connected to the drain terminal of each switching element, and each sensing line may extend from the source terminal of each switching element.

The X signal line (X) controls to supply sensing voltages to all channels (Ch_1 to Ch_4) in the sensing section. When an X signal flows through the X signal line (X), all switching elements on the

The data driver according to an example of the present invention uses signals that control the connection of the data voltage switching lines (D_SW1, D_SW2) that supply the data voltage, and an X signal that controls the connection of the sensing line to receive the sensing voltage. creates . In other words, there is no need for a separate multiplexer or signal generator to generate the X signal. In addition, the

The data driver of the present invention uses the ) can be omitted. Accordingly, an example of the present invention can eliminate the sensing voltage switching lines (SMUX1 to SMUX3) and the S multiplexer. Accordingly, the volume and manufacturing cost of the data driver can be reduced.

More specifically, the data driver according to an example of the present invention switches the data voltage generated by a display multiplexer (hereinafter referred to as “D multiplexer”) that controls the connection of the data voltage switching lines (D_SW1 and D_SW2) (hereinafter referred to as “D multiplexer”). (referred to as “D switching”) further includes a negated logical product (NAND) gate supplied with signals.

The two input terminals of the NAND gate are connected to the first data voltage switching line (D_SW1) and the second data voltage switching line (D_SW2). The output terminal of the negated logical product (NAND) gate is connected to the X signal line (X). Accordingly, the signal output from the output terminal of the negative logical product (NAND) gate is supplied to the X signal line (X). That is, the negative logical product (NAND) gate receives the D switching signals flowing through the first data voltage switching line (D_SW1) and the second data voltage switching line (D_SW2), and sends the It can be supplied to X). Since the

The present invention controls the supply of sensing voltage to the sensing lines using the conventional sensing voltage switching lines (SMUX1 to SMUX3) and an S multiplexer that supplies signals to the sensing voltage switching lines (SMUX1 to SMUX3). The same task can be performed using the X signal output from one negated logical product (NAND) gate. Accordingly, an example of the present invention proposes a specific method that can replace the roles played by the sensing voltage switching lines (SMUX1 to SMUX3) and the S multiplexer while eliminating them.

Preferably, the X signal line (X) is connected to all gate terminals of transistors connected to the sensing line. Accordingly, the X signal can be supplied simultaneously to all gate terminals of the transistors connected to the sensing line.

Conventionally, separate sensing voltage switching lines (SMUX1 to SMUX3) and an S multiplexer were provided for each RGB color. However, even when the sensing voltage is supplied for each RGB color, there is no need to turn on the transistor that plays the role of switching the sensing line connected to each color. In addition, when separate sensing voltage switching lines (SMUX1 to SMUX3) and an S multiplexer are provided for each RGB color, a problem occurred in which the output voltage of the S multiplexer except for the color being sensed is floating.

In the present invention, regardless of RGB color, one X signal can be simultaneously supplied to all gate terminals of transistors connected to the sensing line. All transistors connected to the sensing line can be controlled using the X signal. Accordingly, the role previously performed by the sensing voltage switching lines (SMUX1 to SMUX3) and the S multiplexer can be performed using only one signal line. Ultimately, the width of the bezel can be reduced as the number of lines is reduced, making it possible to implement a narrow bezel display device.

In the present invention, the transistor of the sensing line supplied with the X signal is turned on. The turned-on transistor connects the sensing line supplied with the X signal to the pixels (P) and the data driver. Accordingly, the sensing line supplied with the X signal can supply the sensing voltage supplied from the pixels P to the data driver.

The transistor in the sensing line of the present invention blocks the connection between the sensing line and the data driver when the X signal is not supplied, and connects the sensing line and the data driver when the X signal is supplied. Accordingly, the sensing line of the present invention can use the X signal to supply a sensing voltage to the data driver only in the sensing section.

According to the image of the pixel P connected to the data driver in FIG. 5 and the driving method of the pixel P in conjunction with FIGS. 3 to 5, the pixels P are supplied with gate signals G1 and G2. At this time, the sensing voltage of the organic light-emitting diode (OLED) is supplied to the reference line (Ref), which serves as a sensing line. Therefore, in the present invention, the sensing line supplied with the X signal can supply the sensing voltage to the data driver when the gate signals G1 and G2 are supplied to the pixels P. Accordingly, the sensing voltage can be supplied to the data driver according to the sensing section, and the input of unnecessary signals can be prevented by blocking the connection between the data driver and the sensing line in the display section where the gate signal (G1, G2) is not supplied. there is.

A method of driving a display device according to an example of the present invention includes the following steps.

First, the data driver 120 receives a sensing voltage from pixels (P) that display images. After sensing the difference in physical characteristics between the pixels (P), the data driver 120 must supply a data voltage to compensate for the difference in characteristics and display an image with uniform luminance on the display panel 100. Sensing voltages representing the characteristics of the pixels (P) are generated from the pixels (P) in the sensing section. The data driver 120 receives the sensing voltage through a sensing line in the sensing section. The data driver 120 generates sensing data (SD) based on the sensing voltage.

Second, the timing controller 130 receives sensing data (SD) based on the sensing voltage from the data driver 120 and supplies a data driver control signal (DCS) to the data driver 120. The timing controller 130 controls the data driver 120 to display an image with uniform luminance on the display panel 100 by compensating for differences in characteristics for each pixel P using the data driver control signal DCS.

Third, the data driver 120 supplies data voltage to the pixels (P). The data driver 120 uses the data driver control signal (DCS) supplied from the timing controller 130 to compensate for differences in characteristics for each pixel (P) and displays an image with uniform luminance on the display panel 100. You can.

In particular, the step in which the data driver 120 of the present invention receives the sensing voltage from the pixels (P) that display the image uses the signals of the data voltage switching lines (D_SW1 and D_SW2) that supply the data voltage. It includes generating an X signal that controls the connection of a sensing line to receive voltage.

The X signal is supplied to the sensing line through the X signal line (X). By using the That is, the present invention can omit the conventional sensing voltage switching lines (SMUX1 to SMUX3) and S multiplexers and perform the step of receiving the sensing voltage using a single signal.

In addition, the step of receiving the sensing voltage of the present invention further includes the step of supplying an do.

For this purpose, the present invention adds one negated logical product (NAND) gate. Two signals supplied from the data voltage switching lines (D_SW1, D_SW2) are input to the input terminal of the negated logical product (NAND) gate. The output terminal of the negated logical product (NAND) gate is connected to the X signal line (X). The negative logical product (NAND) gate outputs an This is the same waveform as the signal supplied using conventional sensing voltage switching lines (SMUX1 to SMUX3) and S multiplexers.

In other words, the present invention uses only one negative logical product (NAND) gate and the Supply the same signal. Accordingly, the present invention presents a specific implementation method that can generate a signal in the same sensing section while omitting the sensing voltage switching lines (SMUX1 to SMUX3) and S multiplexers.

In the step of supplying the X signal to the sensing line of the present invention, the X signal is simultaneously supplied to all gate terminals of the transistor connected to the sensing line. Conventionally, when sensing lines were connected to each pixel, the pixels were divided by color and separate signals were supplied. For example, when supplying signals to sensing lines connected to RGB pixels, three sensing voltage switching lines (SMUX1 to SMUX3) and three S multiplexers were required.

However, even when sensing voltage is supplied for each color, there is no need to supply separate signals for each color. Focusing on this point, the present invention supplies a single It can be made into a state where the sensing voltage can be supplied.

In addition, in the step where the data driver 120 of the present invention receives the sensing voltage from the pixels (P) that display the image, the sensing voltage supplied from the pixels (P) is supplied using the sensing line supplied with the It further includes supplying data to the data driver 120.

The X signal is supplied to the gate terminals of the transistors on the sensing line. Accordingly, when the X signal is supplied, the transistors on the sensing line are turned on, connecting the pixels P and the data driver 120 to each other. Accordingly, the sensing voltage generated by the pixels P in the sensing section can be transmitted to the data driver 120 using the X signal.

Here, in the step of supplying the sensing voltage supplied from the pixels (P) to the data driver 120 using the sensing line supplied with the X signal, the sensing line supplied with the When the signals G1 and G2 are supplied, the sensing voltage is supplied to the data driver 120.

When the gate signals G1 and G2 are supplied to the pixels P, the pixels P generate a sensing voltage. That is, when the gate signals (G1, G2) are supplied to the pixels (P), it corresponds to the sensing period. Accordingly, the present invention connects the sensing line to the data driver 120 using the By not doing so, you can prevent the input of unnecessary voltage.

Figure 6 is a waveform diagram showing signals within one sensing frame according to a method of driving a display device according to an example of the present invention. In the present invention, it is assumed that the switching elements are turned on when the input signals are at a low logic level. This is because the switching elements are turned on when they are at a low logic level in the case of PMOS.

The Sensing Data Enable (SDE) signal allows starting the task of performing sensing for each color within the sensing section.

Signals of the data voltage switching lines (D_SW1, D_SW2) alternately have low logic levels in one sensing period. In Figure 6, the switching elements of the first data voltage switching line (D_SW1) are driven. Accordingly, it is possible to prevent switching elements from being deteriorated.

The X signal of the X signal line (X) has a low logic level in the sensing section. Accordingly, the sensing line may connect the pixels P and the data driver 120 so that the sensing voltage is transmitted to the data driver 120 in the sensing section by the X signal.

Gate signals (G1, G2) have a low logic level in the sensing period. The gate signals G1 and G2 allow each pixel P to generate a sensing voltage in the sensing section and supply it to the sensing line.

The emission signal (EM) has a high logic level in the sensing section. Accordingly, the light emission signal EM prevents the data voltage from being supplied to the pixels P in the sensing section. The light emitting signal (EM) causes current to flow through the organic light emitting diode (OLED) of each pixel (P) in the display section to emit light.

The Sensing Channel Select (SCS) signal has a high logic level for each RGB color in the sensing section. The sensing channel selection (SCS) signal is a control signal transmitted from the timing controller 130 to the data driver 120 to select the channel corresponding to the color to be sensed.

The PRE signal has a high logic level at the beginning of the sensing period, and the sensing (SEN) signal has a high logic level at the end of the sensing period. The pre (PRE) signal and the sensing (SEN) signal are control signals used during sensing. Here, the PRE signal controls the beginning of the sensing period, and the sensing (SEN) signal controls the latter part of the sensing period.

Ultimately, the display device and its driving method according to an example of the present invention reduce the number of lines by consolidating the sensing control of each color pixel from three to one signal. Accordingly, there is an effect of reducing the size of the bezel by reducing the number of sensing control lines. Specifically, by reducing two lines, the width of the bezel can be reduced by about 0.3mm.

In addition, the display device and its driving method according to an example of the present invention can control the sensing section with a signal created by passing the control signals of two existing data line switching multiplexers through a negated logical product (NAND) gate. Accordingly, the number of pins can be reduced by eliminating all three pins (PINs) for conventional sensing control. Accordingly, there is a chip integration (CI) effect and a chip size reduction effect.

Although embodiments of the present invention have been described in more detail with reference to the accompanying drawings, the present invention is not necessarily limited to these embodiments, and various modifications may be made without departing from the technical spirit of the present invention. . Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but are for illustrative purposes, and the scope of the technical idea of the present invention is not limited by these embodiments. Accordingly, the embodiments described above should be understood in all respects as illustrative and not restrictive. The scope of protection of the present invention should be interpreted in accordance with the claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of rights of the present invention.

100: display panel 110: gate driver
120: data driver 130: timing controller
TD: Driving transistors T1 to T5: First to fifth transistors
C1: First capacitor Ch_1~Ch_4: Multiple channels
Ref: reference voltage line, REF_SW1, REF_SW2: reference voltage switching lines
X: X signal line D_SW1, D_SW2: Data voltage switching lines

Claims (10)

a display panel provided with pixels that display images;
a data driver that supplies a data voltage to the pixels and receives a sensing voltage from the pixels;
It includes a timing controller that supplies a data driver control signal to the data driver and receives sensing data based on the sensing voltage from the data driver,
The data driver,
Using signals from a data voltage switching line that supplies the data voltage, an
The data driver,
It further includes a negative logical product gate that receives data voltage switching signals generated by a display multiplexer that controls the connection of the data voltage switching line,
The negative AND gate simultaneously supplies the X signal to all gate terminals of connected transistors. delete delete According to claim 1,
A display device in which the sensing line supplied with the X signal supplies the sensing voltage supplied from the pixels to the data driver. According to claim 4,
A sensing line supplied with the X signal supplies the sensing voltage to the data driver when a gate signal is supplied to the pixels. A data driver receiving a sensing voltage from pixels that display images;
A timing controller receiving sensing data based on the sensing voltage from the data driver and supplying a data driver control signal to the data driver; and
The data driver includes supplying a data voltage to the pixels,
The step of the data driver receiving a sensing voltage from pixels that display images is,
Using signals from a data voltage switching line that supplies the data voltage, generating an
The step of the data driver receiving a sensing voltage from pixels that display an image is to connect the X signal to the sensing line using data voltage switching signals generated by a display multiplexer that controls the connection of the data voltage switching line. A method of driving a display device, further comprising simultaneously supplying power to all gate terminals of a transistor. delete delete The method of claim 6, wherein the data driver receives a sensing voltage from pixels that display images,
A method of driving a display device further comprising supplying a sensing voltage supplied from the pixels to the data driver using a sensing line supplied with the X signal. The method of claim 9, wherein the step of supplying the sensing voltage supplied from the pixels to the data driver using the sensing line supplied with the
A method of driving a display device in which the sensing line supplied with the X signal supplies the sensing voltage to the data driver when a gate signal is supplied to the pixels.

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