Display device

Abstract

A display device includes: a pixel connected to a scan line, a data line, and a sensing line; a power supply that supplies a voltage of the first driving power source to the first power line, supplies a voltage of the second driving power source to the second power line, and supplies a voltage of the third driving power source to the third power line; a plurality of first switches respectively positioned on the plurality of pixel rows; and a plurality of second switches respectively positioned on the plurality of pixel rows. A first switch positioned on an i-th pixel row is connected between a pixel positioned on the i-th pixel row and the first power line, and a second switch positioned on the i-th pixel row is connected between the pixel positioned on the i-th pixel row and the second power line, where i is a natural number greater than 0. The first switch and the second switch positioned on the i-th pixel row are alternately turned on and off.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and all benefits arising from Korean Patent Application No. 10-2023-0079708, filed on June 21, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure generally relates to a display device and a method of driving the display device. Background Art

[0004] As information technology develops, the importance of display devices as a connection medium between users and information increases. Therefore, display devices such as liquid crystal display devices and organic light emitting display devices are widely used in various fields.

[0005] The pixels of the display device may deteriorate corresponding to the use time or display brightness, etc., and thus correction of data (grayscale correction) may be required. An external compensation method may be used to correct the data corresponding to the characteristics of the pixels. Summary of the invention

[0006] In a display device using an external compensation method for correcting data corresponding to characteristics of a pixel to compensate for a degraded pixel, the characteristics of the pixel are sensed during a separate sensing period, and the data is corrected using the sensing data corresponding to the characteristics of the pixel. When the voltage of a driving power source supplied to the pixel during the sensing period is not constant, the characteristics of the pixel cannot be accurately sensed, and thus the reliability of compensation may deteriorate.

[0007] The embodiment provides a display device and a method of driving the display device capable of constantly maintaining a voltage of a driving power source during a sensing period of a pixel.

[0008] According to an embodiment of the present disclosure, a display device includes: pixels, connected to scan lines, data lines and sensing lines; a power supply, supplying a voltage of a first driving power source to a first power line, the power supply supplies a voltage of a second driving power source to a second power line, and the power supply supplies a voltage of a third driving power source to a third power line; a plurality of first switches, respectively positioned on a plurality of pixel rows; and a plurality of second switches, respectively positioned on the plurality of pixel rows, wherein a first switch positioned on the i-th pixel row among the plurality of first switches is connected between a pixel positioned on the i-th pixel row and the first power line, and a second switch positioned on the i-th pixel row among the plurality of second switches is connected between the pixel positioned on the i-th pixel row and the second power line, wherein i is a natural number greater than 0, and wherein the first switch and the second switch positioned on the i-th pixel row are alternately turned on and off.

[0009] In an embodiment, during a display period in which an image is displayed by the pixels, the plurality of first switches may be turned on, and the plurality of second switches may be turned off.

[0010] In an embodiment, the display period may be an effective period included in one frame period.

[0011] In an embodiment, during a sensing period in which the pixels positioned on the i-th pixel row are sensed, the first switches positioned on the i-th pixel row may be turned off, and the second switches positioned on the i-th pixel row may be turned on.

[0012] In an embodiment, the sensing cycle may include a first cycle and a second cycle, in which the sensing data corresponding to the sensing voltage is sensed from the pixel positioned on the i-th pixel row; in the second cycle, the data signal before the sensing cycle is resupplied.

[0013] In an embodiment, the power supply may supply a voltage of the second driving power source to the second power line during the sensing period, and set the second power line to a floating state during the display period.

[0014] In an embodiment, during the sensing period in which the pixel positioned on the i-th pixel row is sensed, the first switches among the plurality of first switches positioned on other pixel rows except the i-th pixel row can be set to an on state, and the second switches among the plurality of second switches positioned on other pixel rows can be set to an off state.

[0015] In an embodiment, the sensing period may be a vertical blanking period included in one frame period.

[0016] In an embodiment, the display device may further include: a data driver that supplies a data signal to the data line during the display period and supplies a voltage of a reference power source to the data line during the sensing period; a scan driver that supplies a scan signal to the scan line; a sensing unit connected to the sensing line, wherein the sensing unit can generate sensing data corresponding to a sensing voltage supplied from the pixel positioned on the i-th pixel row during the sensing period in which the pixel positioned on the i-th pixel row is sensed; and a timing controller that generates output data by correcting input data input from the outside using the sensing data.

[0017] In an embodiment, the timing controller may control turning on and off of the plurality of first switches and the plurality of second switches through a switch control signal supplied to the timing controller.

[0018] According to an embodiment of the present disclosure, a display device includes: a plurality of pixels connected to scan lines, data lines and sensing lines, wherein each of the plurality of pixels includes a first switch and a second switch; and a power supply, supplying a voltage of a first driving power source to a first power line, the power supply supplies a voltage of a second driving power source to a second power line, and the power supply supplies a voltage of a third driving power source to a third power line, wherein the first switch included in each of the plurality of pixels is connected to the first power line, and the second switch included in each of the plurality of pixels is connected to the second power line, and wherein, during a display period in which the plurality of pixels display an image, the first switch included in each of the plurality of pixels is in an on state, and the second switch included in each of the plurality of pixels is in an off state.

[0019] In an embodiment, during a sensing period in which pixels positioned on the i-th pixel row among the multiple pixels are sensed, the first switch included in each of the pixels positioned on the i-th pixel row among the multiple pixels may be in an off state, and the second switch included in each of the pixels positioned on the i-th pixel row among the multiple pixels may be in an on state, where i is a natural number greater than 0.

[0020] In an embodiment, the display period may be an effective period included in one frame period, and the sensing period may be a vertical blanking period included in the one frame period.

[0021] In an embodiment, the power supply may supply a voltage of the second driving power source to the second power line during the sensing period, and set the second power line to a floating state during the display period.

[0022] In an embodiment, the display device may further include: a data driver that supplies a data signal to the data line during the display period and supplies a voltage of a reference power source to the data line during the sensing period; a scan driver that supplies a scan signal to the scan line; a sensing unit that generates sensing data corresponding to a sensing voltage supplied from the pixel positioned on the i-th pixel row during the sensing period; and a timing controller that generates output data by correcting input data input from the outside using the sensing data.

[0023] In an embodiment, the timing controller may control turning on and off of the plurality of first switches and the plurality of second switches through a switch control signal supplied to the timing controller.

[0024] According to an embodiment of the present disclosure, a method for driving a display device includes: during a display period, supplying a voltage of a first driving power source to a driving transistor included in each of a plurality of pixels via a first power line; and during a sensing period, supplying a voltage of a second driving power source different from the first driving power source to the driving transistor included in each of the plurality of pixels via a second power line.

[0025] In an embodiment, the second power line may be set to a floating state during the display period.

[0026] In an embodiment, the display period may be an effective period included in one frame period, and the sensing period may be a vertical blanking period included in the one frame period.

[0027] In an embodiment, the method may further include: generating output data corresponding to sensing data generated from the plurality of pixels during the sensing period by correcting input data; and generating a data signal using the output data, and supplying the data signal to the plurality of pixels during the display period. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The above and other features of the present invention will become more apparent by further describing the embodiments of the present invention in detail with reference to the accompanying drawings, in which:

[0029] Figure 1 is a schematic diagram showing a display device according to an embodiment of the present disclosure;

[0030] Figure 2is a schematic diagram showing a pixel and a sensing channel according to an embodiment of the present disclosure;

[0031] Figure 3 is a waveform diagram illustrating an embodiment of a method of driving a pixel during a display period;

[0032] Figure 4 is a waveform diagram illustrating an embodiment of a method of driving a pixel during a sensing period;

[0033] Figure 5 is a schematic diagram showing an embodiment of a voltage of a first driving power source;

[0034] Figure 6 and Figure 7 is a schematic diagram showing an embodiment of a voltage of a second driving power source;

[0035] Fig. 8A and Figure 8B is a schematic diagram showing an embodiment of an image displayed in a pixel unit when a voltage of a first driving power source or a voltage of a second driving power source is supplied during a sensing period;

[0036] Fig. 9 is a schematic diagram showing a display device according to an embodiment of the present disclosure; and

[0037] Figures 10 to 11B It is shown Fig. 9 A schematic diagram of an embodiment of a pixel is shown in FIG. DETAILED DESCRIPTION

[0038] Hereinafter, the present invention will now be described more fully with reference to the accompanying drawings, in which various embodiments are illustrated. However, the present invention may be implemented in different forms and should not be construed as being limited to the embodiments set forth herein. On the contrary, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the scope of the invention to those skilled in the art. The same reference numerals always refer to the same elements.

[0039] In order to clearly describe the present disclosure, parts irrelevant to the description will be omitted, and the same or similar constituent elements will be denoted by the same reference numerals throughout the specification.

[0040] In addition, for better understanding and ease of description, the size and thickness of each component shown in the drawings are arbitrarily illustrated, but the present disclosure is not limited thereto. For clarity of expression, the thickness of several parts and regions is exaggerated.

[0041] It will be understood that when an element is referred to as being "on" another element, the element can be directly on the other element or intervening elements can exist between the element and the other element. In contrast, when an element is referred to as being "directly on" another element, there are no intervening elements.

[0042] Some embodiments related to functional blocks, units and / or modules are described in the accompanying drawings. It will be understood by those skilled in the art that these (multiple) blocks, units and / or modules are physically implemented by logic circuits, discrete components, microprocessors, hard-wired circuits, storage elements, line connections and other electronic circuits. These can be formed by using semiconductor-based manufacturing techniques or other manufacturing techniques. By using software, blocks, units and / or modules implemented by microprocessors or other similar hardware are programmed and controlled to perform various functions discussed herein, and the blocks, units and / or modules can be optionally driven by firmware and / or software. In addition, each block, each unit and / or each module can be implemented by dedicated hardware or by a combination of dedicated hardware that performs some functions of the blocks, units and / or modules and processors (e.g., one or more programmed microprocessors and related circuits) that perform other functions of the blocks, units and / or modules. In addition, without departing from the scope of the present disclosure, in some embodiments, the blocks, units and / or modules can be physically separated into two or more separate blocks, two or more separate units and / or two or more separate modules. Furthermore, in some embodiments, the blocks, units and / or modules may be physically separated into more complex blocks, more complex units and / or more complex modules without departing from the scope of the present disclosure.

[0043] The term "connection" between two components may include both electrical connection and physical connection, but the present disclosure is not necessarily limited thereto. For example, the term "connection" used based on a circuit diagram may represent an electrical connection, and the term "connection" used based on a cross-sectional view and a plan view may represent a physical connection.

[0044] It will be understood that although the terms "first", "second", etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. Therefore, without departing from the teachings of the present disclosure, the "first" element discussed below may also be referred to as the "second" element.

[0045] The terms used herein are only for the purpose of describing a particular embodiment, and are not intended to be restrictive. Unless the context clearly indicates otherwise, as used herein, "one", "one (kind / person)", "described (should)" and "at least one (kind / person)" do not represent the limitation of quantity, and are intended to include both singular and plural. Therefore, the "described (should)" element after the "one (kind / person)" element in the claim includes one element and a plurality of described elements. For example, unless the context clearly indicates otherwise, "an element" has the same meaning as "at least one element". "At least one (kind / person)" is not interpreted as being limited to "one" or "one (kind / person)". "Or" means "and / or". As used herein, the term "and / or" includes any combination and all combinations of one or more related listed items. It will also be understood that the terms “comprises,” “comprising,” or “includes,” “including,” when used in this specification, specify the presence of stated features, regions, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and / or groups thereof.

[0046] In addition, relative terms such as "lower" or "bottom" and "upper" or "top" may be used herein to describe the relationship of one element to another element as shown in the accompanying drawings. It will be understood that, in addition to the orientations depicted in the accompanying drawings, relative terms are intended to cover different orientations of the device. For example, if the device in a figure is turned over, the element described as being "on the "lower" side of the other elements will then be oriented "on the "upper" side of the other elements. Therefore, depending on the specific orientation of the accompanying drawings, the term "lower" can cover both "lower" and "upper" orientations. Similarly, if the device in a figure is turned over, the element described as being "below" or "under" the other elements will then be oriented "above" the other elements. Therefore, the terms "below..." or "under..." can cover both upper and lower orientations.

[0047] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those commonly understood by those of ordinary skill in the art to which the present disclosure belongs. It will also be understood that, unless explicitly defined as such herein, terms (such as those defined in general dictionaries) should be interpreted as having a meaning consistent with their context in the relevant art and / or the meaning in this specification, and should not be interpreted in an idealized or overly formalized sense.

[0048] The present disclosure is not limited to the embodiments disclosed below, and can be implemented in various forms. Each embodiment disclosed below can be implemented independently, or can be implemented in combination with at least one other embodiment before being implemented.

[0049] Figure 1 is a schematic diagram showing a display device according to an embodiment of the present disclosure.

[0050] Reference Figure 1 , the display device 10 according to an embodiment of the present disclosure may include a timing controller 11 , a data driver 12 , a scan driver 13 , a pixel unit 14 , a sensing unit 15 , and a power supply 16 .

[0051] The timing controller 11 may receive input data Din and a control signal corresponding to each frame from an external processor. The external processor may include at least one selected from a graphics processing unit (GPU), a central processing unit (CPU), an application processor (AP), and the like.

[0052] The timing controller 11 may generate output data Dout by correcting input data Din, and supply the output data Dout to the data driver 12. The timing controller 11 may be supplied with sensing data Sdata from the sensing unit 15, and correct the input data Din using the sensing data Sdata, thereby generating output data Dout. Characteristic information (e.g., threshold voltage information and / or mobility information) of a driving transistor included in each of the plurality of pixels PX may be included in the sensing data Sdata, and the timing controller 11 may generate output data Dout by correcting the input data Din in a manner of compensating for the characteristics of the driving transistor included in each of the plurality of pixels PX using the sensing data Sdata.

[0053] In an embodiment, the timing controller 11 may correct the input data Din in such a manner that degradation of the light emitting element included in each of the plurality of pixels PX can be compensated. Also, the timing controller 11 may correct the input data Din by reflecting the optical measurement result measured during the process. Also, the timing controller 11 may also provide a control signal suitable for the specifications of each of the data driver 12, the scan driver 13, and the sensing unit 15.

[0054] During the display period, the data driver 12 may generate a data signal (or data voltage) to be supplied to the data lines D1, D2, D3, ... and Dm ("m" is a natural number greater than 0) corresponding to the output data Dout and the control signal supplied from the timing controller 11. The data driver 12 may supply the data signal to the data lines D1 to Dm in units of pixel rows (or horizontal lines). The pixel row may represent the position of the pixels PX connected to the same scan line or arranged in the extension direction of the same scan line.

[0055] In an embodiment, for example, the data signals supplied to the data lines D1 to Dm may be supplied to the pixels PX selected by the first scan signal. In such an embodiment, the data driver 12 may supply the data signals to the data lines D1 to Dm to be synchronized with the first scan signal.

[0056] During the sensing period, the data driver 12 may supply a voltage of a reference power source to the data lines D1 to Dm. The voltage of the reference power source may be set to a voltage at which a driving transistor included in each of the plurality of pixels PX may be turned on.

[0057] The scan driver 13 may supply a first scan signal to the first scan lines S11, S12, S13, ... and S1n ("n" is a natural number greater than 0) and a second scan signal to the second scan lines S21, S22, S23, ... and S2n in response to a control signal from the timing controller 11.

[0058] In an embodiment, for example, the scan driver 13 may sequentially supply a first scan signal having a gate-on voltage (or a conduction level) to the first scan lines S11 to S1n. Moreover, the scan driver 13 may also sequentially supply a second scan signal having a gate-on voltage (or a conduction level) to the second scan lines S21 to S2n. In an embodiment, as Figure 1 As shown in , the display device 10 may include a single scan driver 13 to drive the first scan lines S11 to S1n and the second scan lines S21 to S2n. However, the present disclosure is not limited thereto. For example, in an alternative embodiment, the scan driver 13 may be provided in plurality, and the first scan lines S11 to S1n and the second scan lines S21 to S2n may be supplied with scan signals from different scan drivers, respectively.

[0059] During the display period, when the first scan signal and the second scan signal are sequentially supplied to the pixel PX, the pixel PX is selected in units of pixel rows. The pixel PX selected during the display period may be supplied with a data signal and generate light having a predetermined brightness corresponding to the data signal.

[0060] During the sensing period, the first scanning signal and the second scanning signal are supplied to at least one specific pixel row, so that the pixels located on the specific pixel row (i.e., the pixels to be sensed) are selected. During the sensing period, the sensing unit 15 may supply the voltage of the initialization power source to the sensing line located on the specific pixel row, or receive the sensing voltage (or sensing information) from the pixels connected to the sensing line located on the specific pixel row.

[0061] Threshold voltage information of the driving transistor may be included in the sensing voltage. Mobility information of the driving transistor may be included in the sensing voltage. Degradation information of the light emitting element may be included in the sensing voltage. The sensing unit 15 may be supplied with a sensing voltage from the pixel PX and generate sensing data Sdata using the sensing voltage. The sensing data Sdata may be supplied to the timing controller 11.

[0062] During the display period, the sensing unit 15 may supply the voltage of the initialization power source to the sensing lines I1, I2, I3, ... and Ip ("p" is a natural number greater than 0). During the sensing period, the sensing unit 15 may supply the voltage of the initialization power source to the sensing lines positioned on at least one specific pixel row. During another period, the sensing unit 15 may receive a sensing voltage from a pixel positioned on a specific pixel row.

[0063] The pixel unit 14 includes a pixel PX. Each of the plurality of pixels PX may include a plurality of transistors and at least one light emitting element. When a scan signal is supplied to a scan line connected to the pixel PX, the pixel PX may be selected to be supplied with a data signal from a data line connected to the pixel PX. Each of the plurality of pixels PX supplied with a data signal may supply light of a predetermined brightness corresponding to the data signal to the outside.

[0064] Each of the plurality of pixels PX may be connected to the first power line PL1 or the second power line PL2 . Also, each of the plurality of pixels PX may be connected to the third power line PL3 .

[0065] During the display period, the pixel PX may be connected to the first power line PL1 and the third power line PL3. The pixel PX may be supplied with the voltage of the first driving power source VDD1 through the first power line PL1, and may be supplied with the voltage of the third driving power source VSS through the third power line PL3. The first driving power source VDD1 may be set to a voltage level higher than the voltage level of the third driving power source VSS.

[0066] During the sensing period, pixels located on at least one specific pixel row may be connected to the second power line PL2 and the third power line PL3. Pixels located on the specific pixel row may be supplied with a voltage of the second drive power source VDD2 through the second power line PL2, and may be supplied with a voltage of the third drive power source VSS through the third power line PL3. The second drive power source VDD2 may be set to a voltage level higher than the voltage level of the third drive power source VSS.

[0067] In an embodiment, the pixel PX may be supplied with a voltage of a first driving power source VDD1 during a display period, and the pixel positioned on at least one specific pixel row may be supplied with a voltage of a second driving power source VDD2 during a sensing period. In an embodiment, the first driving power source VDD1 and the second driving power source VDD2 may be set to the same voltage as each other or to different voltages from each other. When the voltage of the second driving power source VDD2 is supplied during the sensing period, the sensing data Sdata in which the characteristics of the pixel PX are reflected may be generated with improved accuracy, and thus the reliability of compensation may be ensured.

[0068] Hereinafter, this will be described in detail. During the display period, the first power line PL1 supplied with the voltage of the first driving power source VDD1 may be commonly connected to the pixel PX. The first driving power source VDD1 may supply a predetermined driving current to the pixel PX connected to the first driving power source VDD1. The amount of the driving current may be determined corresponding to the data signal supplied to each of the plurality of pixels PX, and may be set differently for each frame. When the amount of the driving current is set differently for each frame, the voltage drop of the first driving power source VDD1 may also be set differently for each frame. Moreover, the first power line PL1 supplied with the voltage of the first driving power source VDD1 is commonly connected to the pixel PX, and therefore, the voltage may change due to noise from the pixel PX.

[0069] When pixels positioned on a specific pixel row are supplied with the voltage of the first driving power source VDD1 during a blanking period (or sensing period) between multiple frames, the sensing voltage (or sensing data) generated from the pixels positioned on the specific pixel row may also have a predetermined deviation corresponding to the voltage of the first driving power source VDD1.

[0070] The second driving power source VDD2 is connected to the pixel to be sensed located on a specific pixel row, and the other pixels of the display image are not supplied with any driving current. No voltage drop (or voltage drop is minimized) occurs in the voltage of the second driving power source VDD2, and therefore a constant voltage can be stably maintained. Moreover, the second driving power source VDD2 is connected to the pixel located on the specific pixel row (that is, not connected to the pixel located on the other pixel row of the display image) during the sensing period, and therefore the influence of noise can be minimized.

[0071] Therefore, in an embodiment, the voltage of the second driving power source VDD2 is supplied to pixels located on a specific pixel row during a blanking period (or sensing period) between multiple frames, so that reliable sensing data Sdata reflecting characteristics of the pixels can be generated with improved accuracy.

[0072] The power supply 16 can supply the voltage of the first driving power source VDD1 to the first power line PL1, and supply the voltage of the second driving power source VDD2 to the second power line PL2. Moreover, the power supply 16 can also supply the voltage of the third driving power source VSS to the third power line PL3. Each of the first driving power source VDD1 and the second driving power source VDD2 can be set to a voltage higher than the voltage of the third driving power source VSS.

[0073] In an embodiment, in addition to the voltage of the first driving power source VDD1, the voltage of the second driving power source VDD2, and the voltage of the third driving power source VSS, the power supply 16 may additionally generate various voltages. In an embodiment, for example, the power supply 16 may generate a gate-off voltage, a gate-on voltage, or a gamma voltage, and supply the generated voltage to the display device 10.

[0074] The display device 10 according to the embodiment of the present disclosure may further include first switches SW11 , SW12 , SW13 , . . . , and SW1 n , and second switches SW21 , SW22 , SW23 , . . . , and SW2 n .

[0075] The first switches SW11 to SW1n may be located on pixel rows, respectively. The first switch SW1i (also referred to as the i-th first switch SW1i) located on the i-th (“i” is a natural number greater than 0 and less than or equal to n) pixel row (see Figure 3 ) may be connected between the pixels positioned on the i-th pixel row and the first power line PL1.

[0076] The second switches SW21 to SW2n may be located on pixel rows, respectively. The second switch SW2i (also referred to as the i-th second switch SW2i) located on the i-th pixel row (see Figure 3) can be connected between the pixels positioned on the i-th pixel row and the second power line PL2.

[0077] The first switches SW11 to SW1n and the second switches SW21 to SW2n may be turned on and off by a switch control signal SWcs supplied from the timing controller 11. The first switch SW1i and the second switch SW2i positioned on the i-th pixel row may be alternately turned on and off.

[0078] In an embodiment, during the display period, the first switches SW11 to SW1n may be turned on so that the voltage of the first driving power source VDD1 is supplied to the pixel PX. In an embodiment, during the sensing period, the first switch SW1i positioned on at least one specific pixel row to be sensed (e.g., the i-th pixel row) may be turned off, and the second switch SW2i positioned on the i-th pixel row may be turned on. The pixels positioned on the i-th pixel row may be supplied with the voltage of the second driving power source VDD2, and the pixels positioned on other pixel rows may be supplied with the voltage of the first driving power source VDD1.

[0079] That is, during the sensing period, pixels located on a specific pixel row may be sensed, and other (or remaining) pixels except for the pixels located on the specific pixel row may display a predetermined image corresponding to a data signal.

[0080] Figure 2 is a schematic diagram showing a pixel and a sensing channel according to an embodiment of the present disclosure. Figure 2 In the description, a pixel PXij ("j" is a natural number greater than 0 and less than or equal to m) positioned on the i-th horizontal line (or i-th pixel row) and the j-th vertical line (or j-th pixel column) will be described.

[0081] Reference Figure 2 , the pixel PXij according to an embodiment of the present disclosure may include transistors M1 to M3 , a storage capacitor Cst, and a light emitting element LD.

[0082] The light emitting element LD may be connected between the power line PL1 or PL2 supplying the voltage of the driving power source VDD and the third power line PL3 supplying the voltage of the third driving power source VSS. In an embodiment, for example, the first electrode (e.g., anode electrode) of the light emitting element LD may be connected to the first power line PL1 or the second power line PL2 via the second node N2 and the first transistor M1, and the second electrode (e.g., cathode electrode) of the light emitting element LD may be connected to the third power line PL3. The light emitting element LD may emit light having a brightness corresponding to the amount of the driving current supplied from the first transistor M1.

[0083] The voltage of the first driving power source VDD1 and the voltage of the third driving power source VSS supplied during the display period may have a predetermined potential difference so that the light emitting element LD can emit light. In an embodiment, for example, the first driving power source VDD1 may be a high potential power source having a high voltage, and the third driving power source VSS may be a low potential power source having a voltage lower than that of the first driving power source VDD1.

[0084] The voltage of the second driving power source VDD2 and the voltage of the third driving power source VSS supplied during the sensing period may have a predetermined potential difference so that a current corresponding to the voltage of the reference power source may flow from the first transistor M1 to the second node N2. In an embodiment, for example, the second driving power source VDD2 may be a high potential power source having a high voltage, and the third driving power source VSS may be a low potential power source having a low voltage.

[0085] In an embodiment, the light emitting element LD may be an organic light emitting diode. Alternatively, the light emitting element LD may be an inorganic light emitting diode such as a micro LED (light emitting diode) or a quantum dot light emitting diode. Alternatively, the light emitting element LD may be an element configured by a combination of an organic material and an inorganic material. Figure 2 As shown in , each of the plurality of pixels PXij may include a single light emitting element LD. However, in another embodiment, the pixel PXij may include a plurality of light emitting elements, and the plurality of light emitting elements may be connected in series, in parallel, or in series / parallel with each other.

[0086] In an embodiment, transistors M1, M2, and M3 may be implemented as N-type transistors. In an alternative embodiment, transistors M1, M2, and M3 may be implemented as P-type transistors. In another alternative embodiment, transistors M1, M2, and M3 may be implemented as a combination of N-type transistors and P-type transistors. Transistors may be implemented in various forms such as thin film transistors (TFTs), field effect transistors (FETs), and bipolar junction transistors (BJTs).

[0087] The first transistor M1 may be connected between the first power line PL1 or the second power line PL2 and the second node N2. In addition, the gate electrode of the first transistor M1 may be connected to the first node N1. During the display period, the first transistor M1 may control the amount of current corresponding to the voltage of the first node N1 supplied from the first driving power source VDD1 to the third driving power source VSS via the light emitting element LD. During the sensing period, the first transistor M1 may control the amount of current corresponding to the voltage of the first node N1 supplied from the second driving power source VDD2 to the second node N2. The first transistor M1 may be referred to as a driving transistor.

[0088] The second transistor M2 may be connected between the data line Dj and the first node N1. In addition, the gate electrode of the second transistor M2 may be connected to the first scan line S1i. When the first scan signal is supplied to the first scan line (or the i-th first scan line) S1i, the second transistor M2 may be turned on to electrically connect the data line (or the j-th data line) Dj and the first node N1 to each other. The second transistor M2 may be referred to as a switching transistor.

[0089] The third transistor M3 may be connected between the second node N2 and a sensing line (or k-th sensing line) Ik ("k" is a natural number greater than 0 and less than or equal to p). In addition, a gate electrode of the third transistor M3 may be connected to a second scan line S2i. When a second scan signal is supplied to the second scan line (or i-th second scan line) S2i, the third transistor M3 may be turned on to electrically connect the sensing line Ik and the second node N2 to each other. The third transistor M3 may be referred to as a sensing transistor.

[0090] The storage capacitor Cst may be connected between the first node N1 and the second node N2. The storage capacitor Cst may store a voltage corresponding to a voltage difference between the first node N1 and the second node N2.

[0091] The sensing channel 151 may include an initialization switch SWi, a sampling switch SWs, a sensing capacitor Css, and an analog-to-digital converter (hereinafter, referred to as “ADC”) 152 .

[0092] The initialization switch SWi may be connected between the third node N3 connected to the sensing line Ik and the initialization power source Vint. The initialization switch SWi may be turned on or off corresponding to a control signal supplied from the timing controller 11 to the sensing unit 15. When the initialization switch SWi is turned on, the voltage of the initialization power source Vint may be supplied to the sensing line Ik via the third node N3.

[0093] The sampling switch SWs may be connected between the third node N3 and the fourth node N4. The sampling switch SWs may be turned on or off corresponding to a control signal supplied from the timing controller 11 to the sensing unit 15. When the sampling switch SWs is turned on, the third node N3 and the fourth node N4 may be electrically connected to each other.

[0094] A first electrode of the sensing capacitor Css may be connected to the fourth node N4, and a second electrode of the sensing capacitor Css may be connected to a base power source (eg, ground). The sensing capacitor Css may store a voltage of the fourth node N4.

[0095] The ADC 152 may be connected to the fourth node N4. The ADC 152 may generate sensing data Sdata by using a voltage (eg, sensing voltage) applied to the fourth node N4. The sensing data Sdata may include characteristic (threshold voltage and / or mobility) information of the first transistor M1.

[0096] In an embodiment, the ADC 152 may be positioned for each sensing channel 151. The sensing unit 15 may include ADCs 152 corresponding to a plurality of sensing channels 151. In an alternative embodiment, the ADC 152 may be positioned to be shared by (or commonly connected to) a plurality of sensing channels 151. The ADC 152 may convert the sensing voltages of the plurality of sensing channels 151 by time-dividing the sensing voltages.

[0097] Figure 3 is a waveform diagram illustrating an embodiment of a method of driving a pixel during a display period. Figure 4 is a waveform diagram illustrating an embodiment of a method of driving a pixel during a sensing period.

[0098] Reference Figure 3 and Figure 4 In an embodiment, a frame period may include an active period and a vertical blanking period between adjacent active periods. Figure 3 and Figure 4 In the embodiment, the data enable signal DE may define an effective period during which the data signal is supplied. In an embodiment, for example, a period during which the data enable signal DE is supplied (supplied in the form of pulses) may be defined as an effective period, and a period during which the data enable signal DE is not supplied may be defined as a vertical blanking period. The effective period of one frame may be set as a display period, and the vertical blanking period of one frame may be set as a sensing period.

[0099] Reference Figure 1 , Figure 2 and Figure 3 During the display period (i.e., the effective period), the first switches SW11 to SW1n may be turned on, and the second switches SW21 to SW2n may be turned off. That is, during the display period, the i-th first switch SW1i located on the i-th pixel row may be turned on, and the i-th second switch SW2i located on the i-th pixel row may be turned off. When the i-th first switch SW1i is turned on, the pixel PXij may be connected to the first power line PL1, and accordingly, the voltage of the first driving power source VDD1 may be supplied.

[0100] During the display period, the initialization switch SWi may be set to an on state, and accordingly, the voltage of the initialization power source Vint may be supplied to the sensing line Ik. During the display period, a first scan signal may be supplied to the first scan line S1i, and a second scan signal may be supplied to the second scan line S2i.

[0101] When the first scan signal is supplied to the first scan line S1i, the second transistor M2 may be turned on. When the second transistor M2 is turned on, the data signal DSij from the data line Dj may be supplied to the first node N1. When the second scan signal is supplied to the second scan line S2i, the third transistor M3 may be turned on. When the third transistor M3 is turned on, the voltage of the initialization power source Vint from the sensing line Ik may be supplied to the second node N2. A voltage corresponding to the difference between the voltage of the data signal DSij and the voltage of the initialization power source Vint may be stored in the storage capacitor Cst.

[0102] After the voltage corresponding to the data signal DSij is stored in the storage capacitor Cst, the second transistor M2 may be turned off as the supply of the first scan signal to the first scan line S1i is stopped, and the third transistor M3 may be turned off as the supply of the second scan signal to the second scan line S2i is stopped. Thereafter, the first transistor M1 may supply a driving current from the first driving power source VDD1 to the light emitting element LD corresponding to the voltage stored in the storage capacitor Cst. The brightness of the light emitting element LD may be determined corresponding to the amount of the driving current supplied from the first transistor M1 to the light emitting element LD.

[0103] Reference Figure 2 and Figure 4 , during the sensing period (i.e., the vertical blanking period), sensing information may be extracted on (or obtained from) at least one specific pixel row. In an embodiment, for example, sensing information may be extracted from pixels located on the i-th pixel row (or at least one pixel located on the i-th pixel row). During the sensing period, other pixels to be sensed other than the pixels located on the i-th pixel row may display a predetermined image while being supplied with the voltage of the first driving power source VDD1.

[0104] During the sensing period, the i-th first switch SW1i located on the i-th pixel row may be turned off, and the i-th second switch SW2i may be turned on. When the i-th second switch SW2i is turned on, the pixel PXij located on the i-th pixel row may be connected to the second power line PL2 and accordingly supplied with the voltage of the second driving power source VDD2.

[0105] The sensing period may be divided into a first period P1 and a second period P2. The first period P1 may be a period during which sensing data Sdata corresponding to a sensing voltage is generated, and the second period P2 may be a period during which data is rewritten.

[0106] At a first time point t1 of the first period P1, a first scan signal may be supplied to the first scan line S1i, and a second scan signal may be supplied to the second scan line S2i. When the first and second scan signals are supplied, the second and third transistors M2 and M3 may be turned on.

[0107] When the second transistor M2 is turned on, the reference voltage Vref from the data line Dj may be supplied to the first node N1. The reference voltage Vref is a voltage at which the first transistor M1 may be turned on, and may be predetermined.

[0108] When the third transistor M3 is turned on, the voltage of the initialization power source Vint can be supplied to the second node N2. To this end, the initialization switch SWi can be set to an on state during a period between the first time point t1 and the second time point t2. A voltage corresponding to the difference between the reference voltage Vref and the voltage of the initialization power source Vint can be charged into the storage capacitor Cst. In addition, after the second time point t2, the supply of the voltage of the initialization power source Vint to the sensing line Ik can be suspended.

[0109] After the second time point t2, the supply of the first scan signal may be suspended, and the supply of the second scan signal may be maintained. During the remaining portion of the first period P1 after the second time point t2, the sampling switch SWs may be set to a conducting state.

[0110] During the remaining portion after the second time point t2 in the first period P1, the third transistor M3 may maintain a turned-on state. The first transistor M1 may supply a predetermined current corresponding to the reference voltage Vref from the second driving power source VDD2 to the second node N2, and accordingly, a sensing voltage may be applied to the second node N2. The sensing voltage supplied to the second node N2 may be supplied to the sensing capacitor Css via the third node N3 and the sampling switch SWs.

[0111] The ADC 152 may convert the sensing voltage stored in the sensing capacitor Css into sensing data Sdata in a digital format and supply the sensing data Sdata to the timing controller 11 (see Figure 1 ). The threshold voltage and mobility information of the first transistor M1 may be included in the sensing data Sdata.

[0112] The second period P2 is a period in which a previous data signal REDATA is supplied to restore an image display state before a sensing period. In the second period P2, the initialization switch SWi may be turned on, and the sampling switch SWs may be turned off. When the initialization switch SWi is turned on, the voltage of the initialization power source Vint may be supplied to the sensing line Ik. During the second period P2, the first scan signal may be supplied to the first scan line S1i, and the second scan signal may be supplied to the second scan line S2i. When the first scan signal and the second scan signal are supplied, the second transistor M2 and the third transistor M3 may be turned on.

[0113] When the second transistor M2 is turned on, the voltage of the previous data signal REDATA may be supplied to the first node N1. When the third transistor M3 is turned on, the voltage of the initialization power source Vint may be supplied to the second node N2. The voltage corresponding to the previous data signal REDATA may be stored in the storage capacitor Cst. Thereafter, the pixel PXij may generate light having a brightness corresponding to the previous data signal REDATA.

[0114] As described above, in the embodiment of the present disclosure, the voltage of the first driving power source VDD1 is supplied to the pixel PX during the display period (see Figure 1 ), and the voltage of the second driving power source VDD2 is supplied to the pixels to be sensed located on at least one specific pixel row during the sensing period. Compared with the first driving power source VDD1, the second driving power source VDD2 has a low voltage drop and low noise. Therefore, sensing data reflecting the characteristics of the pixel can be generated with improved accuracy during the sensing period, and thus the reliability of compensation can be ensured.

[0115] Figure 5 is a schematic diagram showing an example of the voltage of the first driving power source.

[0116] Reference Figure 1 and Figure 5 , the first driving power source VDD1 may supply a predetermined driving current to the pixel PX, and is electrically connected to each of the plurality of pixels PX accordingly. When the first driving power source VDD1 supplies the predetermined driving current to the pixel PX, a predetermined voltage drop may occur in the first driving power source VDD1. In addition, when the first driving power source VDD1 is electrically connected to each of the plurality of pixels PX, noise corresponding to the driving of each of the plurality of pixels PX may be transmitted to the first driving power source VDD1.

[0117] In an embodiment, Figure 5As shown in , the first driving power source VDD1 may not maintain a certain voltage, but may change corresponding to time. Therefore, when the voltage of the first driving power source VDD1 is supplied to the pixel to be sensed, the sensing voltage of the second node N2 applied to each of the plurality of pixels may be set differently corresponding to the voltage of the first driving power source VDD1. Although a specific pixel maintains the same characteristics, the sensing data Sdata generated in the specific pixel may be set differently each time corresponding to the voltage of the first driving power source VDD1, and thus the reliability of compensation may deteriorate.

[0118] Figure 6 and Figure 7 is a schematic diagram showing an example of the voltage of the second driving power source.

[0119] Reference Figure 6 , the voltage of the first driving power source VDD1 can be compared with the reference Figure 5 The times mentioned vary accordingly.

[0120] The second driving power source VDD2 may not supply any driving current to the pixel PX (see Figure 1 ), and thus the voltage drop can be minimized. In addition, during the sensing period, the second driving power source VDD2 is connected to the pixels positioned on at least one specific pixel row, and thus the noise from the pixels can be minimized.

[0121] like Figure 6 As shown in Figure 2 , the second driving power source VDD2 can maintain a certain voltage corresponding to time. Therefore, when the voltage of the second driving power source VDD2 is supplied to the pixel to be sensed, the sensing voltage applied to the second node N2 of each of the pixels can accurately reflect the characteristics of the pixel. That is, in the embodiment of the present disclosure, the voltage of the second driving power source VDD2 is supplied to the pixel to be sensed, and accordingly, the sensing data Sdata in which the characteristics of the pixel are reflected can be generated with improved accuracy.

[0122] In an embodiment, Figure 6 As shown in Figure 1 The power supply 16 may supply the voltage of the second driving power source VDD2 to the second power line PL2 during the display period and during the sensing period. However, during the display period, the voltage of the second driving power source VDD2 is not supplied to the pixel PX, and thus may cause unexpected power consumption.

[0123] In an embodiment, Figure 7 As shown in Figure 1, the power supply 16 does not supply the voltage of the second driving power source VDD2 to the second power line PL2 during the display period (i.e., the second power line PL2 is set to a floating state during the display period), but can supply the voltage of the second driving power source VDD2 to the second power line PL2 only during the sensing period. Therefore, the power consumption caused by the second driving power source VDD2 can be minimized.

[0124] Fig. 8A and Figure 8B is a schematic diagram showing an embodiment of an image displayed in a pixel unit when a voltage of a first driving power source or a voltage of a second driving power source is supplied during a sensing period. Fig. 8A shows a case where the voltage of the first driving power source VDD1 is supplied during the sensing period, and Figure 8B A case where the voltage of the second driving power source VDD2 is supplied during the sensing period is shown.

[0125] Reference Figure 1 and Fig. 8A When the voltage of the first driving power source VDD1 is supplied during the sensing period, the sensing data Sdata may deviate corresponding to the voltage variation of the first driving power source VDD1. Although the same data signal is supplied to the pixels PX included in the pixel unit 14, an image in the form of a horizontal line may be displayed on the pixel unit 14.

[0126] Reference Figure 1 and Figure 8B When the voltage of the second driving power source VDD2 is supplied during the sensing period, the second driving power source VDD2 maintains a certain voltage, and thus the sensing data Sdata in which only the characteristics of the pixel are reflected can be generated. When the same data signal is supplied to the pixel PX included in the pixel unit 14, a consistent image can be displayed on the pixel unit 14.

[0127] Fig. 9 is a schematic diagram showing a display device according to an embodiment of the present disclosure. Fig. 9 In, with Figure 1 The same components as those illustrated in FIG. 1 are denoted by the same reference numerals, and any repeated detailed description of the components will be omitted.

[0128] Reference Fig. 9 , a display device 10 a according to an embodiment of the present disclosure may include a timing controller 11 , a data driver 12 , a scan driver 13 , a pixel unit 14 , a sensing unit 15 , and a power supply 16 .

[0129] In such an embodiment, the power supply 16 can supply the voltage of the first driving power source VDD1 to the first power line PL1, and supply the voltage of the second driving power source VDD2 to the second power line PL2. Moreover, the power supply 16 can also supply the voltage of the third driving power source VSS to the third power line PL3. The first power line PL1, the second power line PL2, and the third power line PL3 can be commonly connected to the pixel PXa.

[0130] The pixel unit 14 may include a pixel PXa. Each of the plurality of pixels PXa may include a plurality of transistors and at least one light emitting element. When a scan signal is supplied to a scan line connected to the pixel PXa, the pixel PXa may be selected to be supplied with a data signal from a data line. Each of the plurality of pixels PXa supplied with a data signal may supply light having a predetermined brightness corresponding to the data signal to the outside.

[0131] Each of the plurality of pixels PXa may include a plurality of switches. The switches may selectively connect the first power line PL1 or the second power line PL2 to the first transistor M1 (refer to Figure 2 ).

[0132] During the display period, the first transistor M1 of each of the plurality of pixels PXa may be connected to the first power line PL1. In an embodiment, for example, during the display period, the pixel PXa may be supplied with the voltage of the first driving power source VDD1 via the first power line PL1.

[0133] During the sensing period, the first transistor M1 of each of the plurality of pixels to be sensed positioned on the pixel row may be connected to the second power line PL2. In an embodiment, for example, during the sensing period, the pixels to be sensed positioned on the pixel row may be supplied with the voltage of the second driving power source VDD2 via the second power line PL2.

[0134] Figures 10 to 11B It is shown Fig. 9 A schematic diagram of an embodiment of a pixel is shown in FIG. Fig.10 In the Figure 2 Detailed description of the partially overlapping parts illustrated in FIG.

[0135] Reference Fig.10 , also refer to Figure 1, the pixel PXaij according to an embodiment of the present disclosure may include transistors M1 to M3, a storage capacitor Cst and a light emitting element LD. In such an embodiment, the pixel PXaij may include a first switch SW1 and a second switch SW2. The first switch SW1 and the second switch SW2 may be turned on or off by a switch control signal SWcs supplied from the timing controller 11. In an embodiment, the first switch SW1 and the second switch SW2 may be turned on or off alternately.

[0136] The first switch SW1 may be connected between the first power line PL1 and the first transistor M1. Fig.11A As shown in , the first switch SW1 may be turned on during the display period. When the first switch SW1 is turned on, the first power line PL1 may be electrically connected to the first transistor M1, and accordingly, the first transistor M1 may be driven by the first driving power source VDD1.

[0137] The second switch SW2 may be connected between the second power line PL2 and the first transistor M1. Fig. 11B As shown in , the second switch SW2 may be turned on during the sensing period. When the second switch SW2 is turned on, the second power line PL2 may be electrically connected to the first transistor M1, and accordingly, the first transistor M1 may be driven by the second driving power source VDD2.

[0138] In addition, during the sensing period, the second switch SW2 included in each of the plurality of pixels to be sensed positioned on the pixel row may be turned on. The second switch SW2 included in each of the plurality of pixels not to be sensed positioned on the pixel row may be set to an off state (i.e., the first switch SW1 is set to an on state), and accordingly, the pixels not to be sensed positioned on the pixel row may display a predetermined image corresponding to the data signal.

[0139] In a display device and a method for driving a display device according to the present disclosure, a voltage of a first driving power source may be supplied to a pixel during a display period, and a voltage of a second driving power source may be supplied to a pixel during a sensing period. The second driving power source is set as a power source for maintaining a constant voltage, and therefore, sensing data with high reliability can be generated during a sensing period.

[0140] The present invention should not be interpreted as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure is thorough and complete, and will fully convey the concept of the present invention to those skilled in the art.

[0141] While the invention has been particularly shown and described with reference to embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit or scope of the invention as defined by the following claims.

Claims

1. A display device, wherein: The display device comprises: Pixels, connected to scan lines, data lines, and sense lines; a power supply that supplies a voltage of a first driving power source to a first power line, the power supply that supplies a voltage of a second driving power source to a second power line, and the power supply that supplies a voltage of a third driving power source to a third power line; A plurality of first switches, respectively positioned on a plurality of pixel rows; and A plurality of second switches are respectively positioned on the plurality of pixel rows, wherein a first switch located on the i-th pixel row among the plurality of first switches is connected between a pixel located on the i-th pixel row and the first power line, and a second switch located on the i-th pixel row among the plurality of second switches is connected between the pixel located on the i-th pixel row and the second power line, Where i is a natural number greater than 0, and The first switch and the second switch located on the i-th pixel row are alternately turned on and off.

2. The display device according to claim 1, wherein: During a display period in which an image is displayed by the pixels, the plurality of first switches are turned on, and the plurality of second switches are turned off.

3. The display device according to claim 2, wherein: The display period is an effective period included in one frame period.

4. The display device according to claim 2, wherein: During a sensing period in which the pixels located on the i-th pixel row are sensed, the first switches located on the i-th pixel row are turned off, and the second switches located on the i-th pixel row are turned on.

5. The display device according to claim 4, wherein: The power supply supplies a voltage of the second driving power source to the second power line during the sensing period, and sets the second power line to a floating state during the display period.

6. The display device according to claim 4, wherein: During the sensing period in which the pixels positioned on the i-th pixel row are sensed, the first switches among the plurality of first switches positioned on other pixel rows except the i-th pixel row are in an on state, and the second switches among the plurality of second switches positioned on the other pixel rows are in an off state.

7. The display device according to claim 4, wherein: The sensing period is a vertical blanking period included in one frame period.

8. The display device according to claim 4, wherein: The display device further includes: a data driver that supplies a data signal to the data line during the display period and supplies a voltage of a reference power source to the data line during the sensing period; A scan driver for supplying a scan signal to the scan line; a sensing unit connected to the sensing line, wherein the sensing unit generates sensing data corresponding to a sensing voltage supplied from the pixel positioned on the i-th pixel row during the sensing period in which the pixel positioned on the i-th pixel row is sensed; and a timing controller that generates output data by correcting input data input from the outside using the sensing data; and The timing controller controls the on and off of the plurality of first switches and the plurality of second switches using a switch control signal supplied to the timing controller.

9. A display device, wherein: The display device comprises: a plurality of pixels connected to the scan line, the data line, and the sensing line, wherein each of the plurality of pixels comprises a first switch and a second switch; and a power supply that supplies a voltage of a first driving power source to a first power line, the power supply that supplies a voltage of a second driving power source to a second power line, and the power supply that supplies a voltage of a third driving power source to a third power line, wherein the first switch included in each of the plurality of pixels is connected to the first power line, and the second switch included in each of the plurality of pixels is connected to the second power line, and During a display period in which the plurality of pixels display an image, the first switch included in each of the plurality of pixels is in an on state, and the second switch included in each of the plurality of pixels is in an off state.

10. The display device according to claim 9, wherein: During a sensing period in which pixels located on an i-th pixel row among the plurality of pixels are sensed, the first switch included in each of the pixels located on the i-th pixel row among the plurality of pixels is in an off state, and the second switch included in each of the pixels located on the i-th pixel row among the plurality of pixels is in an on state, wherein i is a natural number greater than 0; and wherein the display period is an effective period included in one frame period, and the sensing period is a vertical blanking period included in the one frame period; and The power supply supplies a voltage of the second driving power source to the second power line during the sensing period, and sets the second power line to a floating state during the display period.

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