Display device and electronic device including light emitting element

Abstract

A display device and an electronic device are disclosed. The display device includes: a display panel including data lines, sensing lines, and pixels connected to the data lines and the sensing lines and including light emitting elements; and a panel driver configured to provide a scan signal and a sensing signal to the pixel, provide a data voltage to the pixel through the data line, provide an initialization voltage to an anode of the light emitting element through the sensing line, provide a first power supply voltage to the pixel, and provide a second power supply voltage to a cathode of the light emitting element of the pixel, the light emitting element is configured to be initialized based on an initialization voltage and a second power supply voltage, a voltage difference between the initialization voltage and the second power supply voltage being smaller than a turn-on voltage of the light emitting element by a margin voltage.

Description

Technical Field

[0001] Embodiments of this disclosure relate to display devices in which each pixel includes a light-emitting element. Background Technology

[0002] The display device may include: a display panel including a plurality of pixels; and a panel driver that drives the display panel. The panel driver may include a scan driver that provides scan signals to the plurality of pixels, a data driver that provides data voltages to the plurality of pixels, and a controller that controls the scan driver and the data driver.

[0003] Recently, variable frame modes (e.g., Free-Sync, G-Sync, etc.) have been developed, in which the panel driver drives the display panel at a variable frequency. In display devices operating in variable frame mode, flickering may occur when the driving frequency used for the display panel changes. Summary of the Invention

[0004] Some implementations provide display devices with improved image quality.

[0005] According to an embodiment, a display device is provided, comprising: a display panel including data lines, sensing lines, and pixels, the pixels being connected to the data lines and sensing lines and including light-emitting elements; and a panel driver configured to provide scan signals and sensing signals to the pixels, provide data voltages to the pixels via the data lines, provide an initialization voltage to the anode of the light-emitting elements via the sensing lines, provide a first power supply voltage to the pixels, and provide a second power supply voltage to the cathode of the light-emitting elements of the pixels, wherein the light-emitting elements are configured to be initialized based on the initialization voltage and the second power supply voltage, and the voltage difference between the initialization voltage and the second power supply voltage is a margin voltage smaller than the turn-on voltage of the light-emitting elements.

[0006] The initial voltage can be positive, and the second power supply voltage can be negative.

[0007] The initial voltage can be basically equal to the on-state voltage of the light-emitting element minus the margin voltage, where the second power supply voltage is basically equal to the ground voltage.

[0008] The pixel may include: a capacitor including a first electrode connected to a gate node and a second electrode connected to a source node; a first transistor including a gate connected to the gate node, a first terminal configured to receive a first power supply voltage, and a second terminal connected to the source node; a second transistor configured to connect a corresponding data line in the data lines to the gate node in response to a scan signal; a third transistor configured to connect a corresponding sensing line in the sensing lines to the source node in response to a sensing signal; and a light-emitting element including an anode connected to the source node and a cathode configured to receive a second power supply voltage.

[0009] The panel driver may include: a first voltage generator configured to generate a first power supply voltage based on a first input voltage, wherein the first power supply voltage is positive; and a second voltage generator configured to generate a second power supply voltage based on the first input voltage, wherein the second power supply voltage is negative.

[0010] During the power-on cycle of the display device, the second power supply voltage can be configured to be activated, and the first power supply voltage can be configured to be activated after the second power supply voltage is activated.

[0011] During the power-off cycle of the display device, the first power supply voltage can be configured to be disabled, and the second power supply voltage can be configured to be disabled after the first power supply voltage is disabled.

[0012] The panel driver may further include: power management circuitry, including an initialization voltage generator configured to generate an initialization voltage based on a second input voltage; and sensing circuitry configured to provide an initialization voltage to a pixel via a sensing line during a driving cycle, and to perform a sensing operation on the pixel via the sensing line during a sensing cycle.

[0013] The panel driver may also include a controller configured to generate a positive voltage enable signal and a negative voltage enable signal, wherein a second voltage generator is configured to generate a second power supply voltage in response to the negative voltage enable signal, and wherein the power management circuitry further includes a positive voltage generator configured to generate a positive voltage in response to the positive voltage enable signal.

[0014] During the driving cycle, the positive voltage enable signal can have a cutoff level, the negative voltage enable signal can have a conduction level, and the cathode of the light-emitting element can be configured to receive a second power supply voltage. During the sensing cycle, the positive voltage enable signal has a conduction level, the negative voltage enable signal has a cutoff level, and the cathode of the light-emitting element is configured to receive a positive voltage generated by the positive voltage generator.

[0015] The panel driver may include a suitable power supply voltage storage device configured to store a suitable voltage level determined by measuring the brightness of the display panel while gradually changing the voltage level of a second power supply voltage, wherein the panel driver is configured to generate a second power supply voltage having a suitable voltage level.

[0016] The panel driver may include a temperature sensor configured to measure the temperature of the display panel, wherein the panel driver is configured to adjust the voltage level of a second power supply voltage according to the temperature.

[0017] The panel driver can be configured to increase the voltage level of the second power supply voltage as the temperature increases.

[0018] The panel driver may include a drive time accumulator configured to accumulate the drive time of the display panel, wherein the panel driver is configured to adjust the voltage level of a second power supply voltage according to the drive time.

[0019] The panel driver can be configured to decrease the voltage level of the second power supply voltage as the driving time increases.

[0020] The panel driver may include a suitable initialization voltage storage, configured to store a suitable voltage level determined by measuring the brightness of the display panel while gradually changing the voltage level of the initialization voltage, wherein the panel driver is configured to generate an initialization voltage with a suitable voltage level.

[0021] According to an embodiment, a display device is provided, comprising: a display panel including a data line, a sensing line, and pixels connected to the data line and the sensing line; a scan driver configured to provide a scan signal and a sensing signal to the pixels; a data driver configured to provide a data voltage to the pixels via the data line; a first voltage generator configured to provide a first power supply voltage to the pixels; a second voltage generator configured to provide a negative second power supply voltage to the pixels; a power management circuit configured to generate a positive initialization voltage; a sensing circuit configured to provide an initialization voltage to the pixels via the sensing line during a driving cycle, and to perform a sensing operation on the pixels via the sensing line during a sensing cycle; and a controller configured to control scanning. The device includes a driver, a data driver, a first voltage generator, a second voltage generator, a power management circuit, and a sensing circuit, wherein the pixel comprises: a capacitor including a first electrode connected to a gate node and a second electrode connected to a source node; a first transistor including a gate connected to the gate node, a first terminal configured to receive a first power supply voltage, and a second terminal connected to the source node; a second transistor configured to connect a corresponding data line in the data lines to the gate node in response to a scan signal; a third transistor configured to connect a corresponding sensing line in the sensing lines to the source node in response to a sensing signal; and a light-emitting element including an anode connected to the source node and a cathode configured to receive a second power supply voltage.

[0022] The controller can be configured to generate a positive voltage enable signal and a negative voltage enable signal, wherein the second voltage generator is configured to generate a second power supply voltage in response to the negative voltage enable signal, and wherein the power management circuit is further configured to generate a positive voltage in response to the positive voltage enable signal.

[0023] During the driving cycle, the positive voltage enable signal can have a cutoff level, the negative voltage enable signal can have a conduction level, and the cathode of the light-emitting element can be configured to receive a second power supply voltage. During the sensing cycle, the positive voltage enable signal has a conduction level, the negative voltage enable signal has a cutoff level, and the cathode of the light-emitting element is configured to receive a positive voltage generated by the positive voltage generator.

[0024] According to an embodiment, a display device is provided, comprising: a display panel including data lines, sensing lines, and pixels, the pixels being connected to the data lines and sensing lines and including light-emitting elements; and a panel driver configured to provide scan signals and sensing signals to the pixels, provide data voltages to the pixels via the data lines, provide a positive initialization voltage to the anode of the light-emitting elements via the sensing lines, provide a first power supply voltage, and provide a negative second power supply voltage to the cathode of the light-emitting elements, wherein the light-emitting elements are configured to be initialized based on the initialization voltage and the second power supply voltage.

[0025] According to an embodiment, an electronic device including a display device is provided. The display device includes: a display panel including data lines, sensing lines, and pixels, the pixels being connected to the data lines and sensing lines and including light-emitting elements; and a panel driver configured to provide scan signals and sensing signals to the pixels, provide data voltages to the pixels via the data lines, provide an initialization voltage to the anode of the light-emitting elements via the sensing lines, provide a first power supply voltage to the pixels, and provide a second power supply voltage to the cathode of the light-emitting elements of the pixels, wherein the light-emitting elements are configured to be initialized based on the initialization voltage and the second power supply voltage, and the voltage difference between the initialization voltage and the second power supply voltage is a margin voltage smaller than the turn-on voltage of the light-emitting elements.

[0026] Electronic devices may include smartphones, televisions, monitors, tablets, electric vehicles, mobile phones, tablet PCs, mobile communication terminals, electronic notebooks, e-books, portable multimedia players (PMPs), navigation devices, ultra-mobile PCs (UMPCs), laptops, billboards, Internet of Things (IoT) devices, smartwatches, watch phones, or head-mounted displays (HMDs).

[0027] As described above, in the display device according to the embodiment, the light-emitting element of each pixel can be initialized based on an initialization voltage applied to the anode of the light-emitting element and a second power supply voltage applied to the cathode of the light-emitting element. The initialization voltage and the second power supply voltage can be set such that the voltage difference between the initialization voltage and the second power supply voltage is less than the turn-on voltage of the light-emitting element by a margin. That is, the voltage difference between the initialization voltage and the second power supply voltage can be close to the turn-on voltage of the light-emitting element. Therefore, the non-emission time of the light-emitting element during initialization can be reduced, and flickering can be reduced when the driving frequency changes. Attached Figure Description

[0028] The illustrative and non-limiting embodiments will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings.

[0029] Figure 1 This is a block diagram illustrating a display device according to an embodiment.

[0030] Figure 2 This is a circuit diagram illustrating an example of pixels included in a display device according to an embodiment.

[0031] Figure 3 This is a timing diagram illustrating an example of input image data fed to a display device at a variable frequency.

[0032] Figure 4 This is a diagram illustrating an example of the brightness of a display panel in a conventional display device when the driving frequency changes.

[0033] Figure 5 It is a block diagram used to describe the first power supply voltage and the second power supply voltage in a conventional display device and the first power supply voltage and the second power supply voltage in a display device according to an embodiment.

[0034] Figure 6 This is a timing diagram illustrating an example of the sensing signal for each pixel, the voltage of the source node, and the voltage of the second power supply voltage line in a display device according to an embodiment.

[0035] Figure 7 This is a block diagram showing a portion of a display device according to an embodiment.

[0036] Figure 8 This is a timing diagram illustrating an example of the power sequence of a display device according to an embodiment.

[0037] Figure 9 This is a flowchart illustrating a method for determining an acceptable voltage level for a second power supply voltage for a display device according to an embodiment.

[0038] Figure 10 This is a block diagram showing a portion of a display device according to an embodiment.

[0039] Figure 11 This is a block diagram showing a portion of a display device according to an embodiment.

[0040] Figure 12 This is a diagram illustrating an example of a second power supply voltage based on temperature in a display device according to an embodiment.

[0041] Figure 13 This is a block diagram showing a portion of a display device according to an embodiment.

[0042] Figure 14 This is a diagram illustrating an example of a second power supply voltage according to the driving time in a display device according to an embodiment.

[0043] Figure 15 This is a flowchart illustrating a method for determining an acceptable voltage level for the initialization voltage of a display device according to an embodiment.

[0044] Figure 16 This is a block diagram showing a portion of a display device according to an embodiment.

[0045] Figure 17 This is a block diagram illustrating a display device according to an embodiment.

[0046] Figure 18 This is a timing diagram illustrating an example of the sensing signal for each pixel, the voltage of the source node, and the voltage of the second power supply voltage line in a display device according to an embodiment.

[0047] Figure 19 This is a block diagram illustrating an electronic device including a display device according to an embodiment. Detailed Implementation

[0048] Some aspects of embodiments of this disclosure, and methods of implementing them, can be more readily understood by referring to the detailed description of the embodiments and the accompanying drawings. The described embodiments are provided as examples so that this disclosure will be thorough and complete, and will fully convey aspects of this disclosure to those skilled in the art. Therefore, redundant processes, elements, and techniques that are irrelevant or unrelated to the description of the embodiments, or unnecessary for a person of ordinary skill in the art to fully understand aspects of this disclosure, may be omitted. Unless otherwise stated, the same reference numerals, characters, or combinations thereof denote the same elements throughout the drawings and written description, and therefore, their repeated description may be omitted.

[0049] The described embodiments may have various modifications and may be implemented in different forms, and should not be construed as being limited to the embodiments shown herein. The use of "may," "may," or "may not" in describing embodiments corresponds to one or more embodiments of this disclosure.

[0050] Considering this disclosure as a whole, those skilled in the art will understand that each suitable feature of the various embodiments of this disclosure may be combined in part or in whole, or combined with one another, and may interact and operate technically in a variety of suitable ways, and each embodiment may be implemented independently of or in combination with one another in any suitable manner, unless otherwise stated or implied.

[0051] In the accompanying drawings, the relative dimensions of elements, layers, and regions may be exaggerated for clarity and / or for descriptive purposes. In other words, because the dimensions and thicknesses of elements in the drawings are arbitrarily shown for ease of description, this disclosure is not limited thereto.

[0052] It will be understood that when a component, layer, region, or part (e.g., device, apparatus, circuit, wiring, electrode, terminal, conductive film, etc.) is referred to as being "formed" on, "on," "connected to," or "(operably, functionally, or communicatively) coupled to" another component, layer, region, or part, it can be directly formed on, or directly on, connected to, or directly coupled to another component, layer, region, or part, or indirectly formed on, or indirectly on, or indirectly connected to, or indirectly coupled to another component, layer, region, or part, such that one or more intervening components, layers, regions, or parts may exist. Furthermore, this can generally mean direct or indirect connection or linkage, and integral or non-integral connection or linkage.

[0053] For example, when a layer, region, or component is referred to as "electrically connected" or "electrically coupled" to another layer, region, or component, it may be directly electrically connected or directly coupled to another layer, region, and / or component, or there may be one or more intervening layers, regions, or components. One or more intervening components may include switches, transistors, resistors, inductors, capacitors, diodes, etc. Therefore, connections are not limited to those illustrated in the drawings or detailed descriptions, and may also include other types of connections. In describing embodiments, the term "connection" indicates an electrical connection unless explicitly described as a direct connection, and "direct connection / direct coupling" or "directly on..." means that one component is directly connected or coupled to another component or directly on another component without intermediate components. Similarly, other expressions describing relationships between components, such as "between" and "directly between" or "adjacent to" and "directly adjacent to", can be interpreted similarly. It will be understood that when an element or layer is referred to as "between" two elements or layers, it may be the only element or layer between the two elements or layers, or there may be one or more intervening elements or layers.

[0054] For the purposes of this disclosure, expressions such as “at least one of…”, “any one of…”, or “one or more of…” when placed after an element of a list modify the entire list rather than individual elements within it. For example, “at least one of X, Y, and Z” and “at least one selected from the group consisting of X, Y, and Z” can be interpreted as only X, or only Y, or only Z, or any combination of two or more of X, Y, and Z (e.g., XYZ, XY, YZ, and XZ), or any variation thereof. Similarly, the expression “at least one of A and B” can include A, B, or A and B. As used herein, “or” generally means “and / or,” and the term “and / or” includes any and all combinations of one or more of the related listed items. For example, the expression “A and / or B” can include A, B, or A and B. Similarly, expressions such as “at least one of…”, “multiple,” “one of…”, and other prepositional phrases when placed before or after an element of a list modify the entire list rather than individual elements within it. When describing a range of values ​​such as “C to D”, unless otherwise stated, it means C or greater and D or less.

[0055] It will be understood that while the terms “first,” “second,” “third,” etc., may be used herein to describe various elements, components, regions, layers, and / or parts, these elements, components, regions, layers, and / or parts should not be limited by these terms. These terms do not correspond to a specific order, position, or priority, but are used only to distinguish one element, component, part, region, area, layer, segment, or part from another. Therefore, without departing from the spirit and scope of this disclosure, the first element, first component, first region, first layer, or first part described below may be referred to as a second element, second component, second region, second layer, or second part. Describing an element as a “first” element may not require or imply the presence of a second element or other elements. The terms “first,” “second,” etc., may also be used herein to distinguish elements of different categories or groups. For brevity, the terms “first,” “second,” etc., may respectively represent “first category (or first group),” “second category (or second group),” etc.

[0056] The terminology used herein is for descriptive purposes only and is not intended to limit this disclosure. As used herein, the singular forms “a” and “an” are intended to include the plural forms as well, and the plural forms are intended to include the singular forms as well, unless the context clearly indicates otherwise. It will also be understood that, when used in this specification, the terms “comprises,” “comprising,” “have,” “having,” “includes,” and “including” specify the presence of the described features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or combinations thereof.

[0057] As used herein, the terms “substantially,” “about,” “approximately,” and similar terms are used as approximate terms rather than as terms of degree and are intended to account for inherent deviations in measured or calculated values ​​that would be recognized by those skilled in the art. For example, “substantially” can include a range of + / - 5% of the corresponding value. Given the measurement discussed and the error associated with the measurement of a particular quantity (i.e., limitations of the measurement system), as used herein, “about” or “approximately” includes the value and means within an acceptable range of deviation for the particular value as determined by those skilled in the art. For example, “about” can mean within one or more standard deviations, or within ±30%, ±20%, ±10%, ±5% of the value. Additionally, the word “may” as used in describing embodiments of this disclosure means “one or more embodiments of this disclosure.” Furthermore, the expression “identical” can mean “substantially identical.” In other words, the expression “identical” can include a range acceptable to those skilled in the art. Other expressions may also omit the word “substantially.”

[0058] In some embodiments, well-known structures and arrangements may be described in the accompanying drawings for one or more functional blocks (e.g., block diagrams), units, and / or modules to avoid unnecessarily obscuring the various embodiments. Those skilled in the art will understand that such blocks, units, and / or modules are physically implemented by logic circuits, discrete components, microprocessors, hardwired circuits, memory elements, wire connectors, and other electronic circuits. This can be formed using semiconductor-based manufacturing techniques or other manufacturing techniques. Blocks, units, and / or modules implemented by microprocessors or other similar hardware can be programmed and controlled using software to perform the various functions discussed herein, and optionally can be driven by firmware and / or software. Furthermore, each block, unit, and / or module may be implemented by dedicated hardware, or a combination of dedicated hardware performing some functions and processors performing functions different from those of the dedicated hardware (e.g., one or more programmable microprocessors and associated circuitry). Additionally, in some embodiments, blocks, units, and / or modules may be physically divided into two or more interactive discrete blocks, units, and / or modules without departing from the scope of this disclosure. Furthermore, in some embodiments, without departing from the scope of this disclosure, blocks, units and / or modules may be physically combined into more complex blocks, units and / or modules.

[0059] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. It will also be understood that terms, such as those defined in commonly used dictionaries, shall be interpreted as having the same meaning as they have in the relevant field and / or the context of this specification, and shall not be interpreted in an idealized or overly formal sense unless expressly defined herein.

[0060] Figure 1 This is a block diagram illustrating a display device according to an embodiment. Figure 2 This is a circuit diagram illustrating an example of pixels included in a display device according to an embodiment. Figure 3 This is a timing diagram illustrating an example of input image data fed to a display device at a variable frequency. Figure 4 This is a diagram illustrating an example of the brightness of a display panel in a conventional display device when the driving frequency changes. Figure 5 This is a block diagram used to describe the first power supply voltage and the second power supply voltage in a conventional display device and in a display device according to an embodiment. Figure 6 This is a timing diagram illustrating an example of the sensing signal for each pixel, the voltage of the source node, and the voltage of the second power supply voltage line in a display device according to an embodiment.

[0061] refer to Figure 1The display device 100 according to an embodiment may include: a display panel 110 including a plurality of pixels PX; and a panel driver 120 driving the display panel 110. In some embodiments, the panel driver 120 may include: a scan driver 130 providing a scan signal SC and a sensing signal SS to each of the plurality of pixels PX; a data driver 140 connected to the plurality of pixels PX via a plurality of data lines DL; a sensing circuit 150 connected to the plurality of pixels PX via a plurality of sensing lines SL; a power management circuit 160 generating an initialization voltage VINT; a first voltage generator 170 generating a first power supply voltage ELVDD (e.g., a high power supply voltage); a second voltage generator 180 generating a second power supply voltage ELVSS (e.g., a low power supply voltage); and a controller 190 controlling the scan driver 130, the data driver 140, the sensing circuit 150, the power management circuit 160, the first voltage generator 170, and the second voltage generator 180.

[0062] The display panel 110 may include a plurality of data lines DL, a plurality of sensing lines SL, and a plurality of pixels PX connected to the plurality of data lines DL and the plurality of sensing lines SL. In some embodiments, the display panel 110 may further include a plurality of scan signal lines for transmitting scan signals SC, a plurality of sensing signal lines for transmitting sensing signals SS, a first power supply voltage line for transmitting a first power supply voltage ELVDD, and a second power supply voltage line for transmitting a second power supply voltage ELVSS. Each pixel PX may include a light-emitting element, and the display panel 110 may be a light-emitting display panel.

[0063] For example, such as Figure 2 As shown, each pixel PX can have a 3T1C structure, which includes a first transistor T1, a second transistor T2, a third transistor T3, a capacitor CST, and a light-emitting element LED.

[0064] The capacitor CST can store the data voltage VDAT transmitted from the data line DL through the second transistor T2. The capacitor CST can be referred to as a storage capacitor for storing the data voltage VDAT, but is not limited thereto. In some embodiments, the capacitor CST may include a first electrode connected to the gate node NG and a second electrode connected to the source node NS.

[0065] The first transistor T1 can generate a drive current based on the data voltage VDAT stored in the capacitor CST. The first transistor T1 can be referred to as a drive transistor for generating drive current, but is not limited thereto. In some embodiments, the first transistor T1 may include a gate connected to the gate node NG, a first terminal (e.g., drain) receiving the first power supply voltage ELVDD, and a second terminal (e.g., source) connected to the source node NS.

[0066] The second transistor T2 can connect the data line DL to the gate node NG in response to the scan signal SC. That is, the second transistor T2 can transfer the data voltage VDAT from the data line DL to the gate node NG in response to the scan signal SC. The second transistor T2 may be referred to as a scan transistor, but is not limited thereto. In some embodiments, the second transistor T2 may include a gate for receiving the scan signal SC, a first terminal connected to the data line DL, and a second terminal connected to the gate node NG.

[0067] The third transistor T3 can connect the sensing line SL to the source node NS in response to the sensing signal SS. During the driving cycle of the display panel 110 displaying an image, the switch SW of the sensing circuit 150 can connect the sensing line SL to the power management circuit 160, and the third transistor T3 can transfer the initialization voltage VINT from the sensing line SL to the source node NS in response to the sensing signal SS. When the initialization voltage VINT is applied to the source node NS, the light-emitting element LED can be initialized based on the initialization voltage VINT applied to the anode of the light-emitting element LED and the second power supply voltage ELVSS applied to the cathode of the light-emitting element LED. During the sensing cycle in which the sensing circuit 150 performs sensing operations on multiple pixels PX, the third transistor T3 can connect the sensing line SL to the source node NS in response to the sensing signal SS, the switch SW of the sensing circuit 150 can connect the sensing line SL to the analog-to-digital converter ADC of the sensing circuit 150, and the sensing circuit 150 can sense the characteristics of the pixels PX through the sensing line SL. In some embodiments, the third transistor T3 may include a gate for receiving the sensing signal SS, a first terminal connected to the source node NS, and a second terminal connected to the sensing line SL.

[0068] The light-emitting element (LED) can emit light based on a drive current flowing from a first power supply voltage line ELVDDL to a second power supply voltage line ELVSSL. In some embodiments, the LED may include an anode connected to the source node NS and a cathode receiving the second power supply voltage ELVSS. In some embodiments, the LED may be an organic light-emitting diode (“OLED”). In other embodiments, the LED may be a nano-LED (“NED”), a quantum dot (“QD”) LED, a micron-LED, an inorganic LED, or any other suitable light-emitting element.

[0069] In some implementations, such as Figure 2 As shown, the first transistor T1, the second transistor T2, and the third transistor T3 can be implemented as, but are not limited to, N-type metal-oxide-semiconductor (“NMOS”) transistors. Furthermore, although... Figure 2An example of a pixel PX with a 3T1C structure is shown, but the pixel PX according to the embodiment is not limited to... Figure 2 Examples.

[0070] The scan driver 130 can generate a scan signal SC and a sensing signal SS based on the scan control signal SCTRL received from the controller 190. It can provide the scan signal SC sequentially to multiple pixels PX row by row via multiple scan signal lines, and the sensing signal SS sequentially to multiple pixels PX row by row via multiple sensing signal lines. In some embodiments, the scan control signal SCTRL may include a scan start signal and a scan clock signal, but is not limited thereto. In some embodiments, the scan driver 130 may be integrated or formed in the display panel 110. In other embodiments, the scan driver 130 may be implemented using one or more integrated circuits.

[0071] Data driver 140 can generate a data voltage VDAT based on a data control signal DCTRL received from controller 190 and output image data ODAT, and can provide the data voltage VDAT to multiple pixels PX via multiple data lines DL. In some embodiments, the data control signal DCTRL may include, but is not limited to, an output data enable signal, a level start signal, and a load signal. Furthermore, in some embodiments, data driver 140 can receive output image data ODAT from controller 190 at a variable frequency VF (e.g., in the range of about 48 Hz to about 240 Hz). In some embodiments, data driver 140 and sensing circuit 150 can be implemented as a single integrated circuit, which may be referred to as a readout source driver integrated circuit (“RSIC”). In other embodiments, data driver 140 and controller 190 can be implemented as a single integrated circuit, which may be referred to as a timing controller embedded data driver (“TED”) integrated circuit. In still other embodiments, data driver 140, sensing circuit 150, and controller 190 can be implemented as separate integrated circuits.

[0072] Power management circuit 160, first voltage generator 170, and second voltage generator 180 can respectively generate the voltages VINT, ELVDD, and ELVSS required for the operation of display device 100. In some embodiments, first voltage generator 170 can generate a first power supply voltage ELVDD as a positive voltage based on a first input voltage VIN1, and second voltage generator 180 can generate a second power supply voltage ELVSS as a negative voltage based on the first input voltage VIN1. First voltage generator 170 can provide the first power supply voltage ELVDD to a plurality of pixels PX via a first power supply voltage line ELVDDDL, and second voltage generator 180 can provide the second power supply voltage ELVSS to a plurality of pixels PX via a second power supply voltage line ELVSSL. Furthermore, power management circuit 160 can generate an initialization voltage VINT for initializing the light-emitting element LED based on a second input voltage VIN2. According to embodiments, the second input voltage VIN2 can be different from the first input voltage VIN1, or it can be substantially the same as the first input voltage VIN1. In some embodiments, the power management circuit 160, the first voltage generator 170, and the second voltage generator 180 may include, but are not limited to, a buck converter and / or a linear regulator for converting the first input voltage VIN1 and the second input voltage VIN2 into desired voltages VINT, ELVDD, and ELVSS, respectively. Furthermore, in some embodiments, the power management circuit 160, the first voltage generator 170, and the second voltage generator 180 may be implemented as separate integrated circuits. In other embodiments, at least two of the power management circuit 160, the first voltage generator 170, and the second voltage generator 180 may be implemented as a single integrated circuit.

[0073] The sensing circuit 150 can provide an initialization voltage VINT generated by the power management circuit 160 to multiple pixels PX via multiple sensing lines SL during a drive cycle, and can perform sensing operations to sense characteristics of the multiple pixels PX (e.g., the threshold voltage and / or mobility of the first transistor T1) via the multiple sensing lines SL during a sensing cycle. In some embodiments, the sensing circuit 150 may include a switch SW that selectively connects the sensing lines SL to the power management circuit 160 or to an analog-to-digital converter (ADC), and the sensing circuit 150 may also include an ADC that converts the analog signal (voltage or current) from the sensing lines SL into a digital signal. The switch SW can connect the sensing lines SL to the power management circuit 160 during a drive cycle, and can also connect the sensing lines SL to the ADC during a sensing cycle. The ADC can convert the analog signal received from the pixels PX via the sensing lines SL into digital sensing data, and the sensing circuit 150 can provide the digital sensing data representing the characteristics of the pixels PX to the controller 190.

[0074] Controller 190 (e.g., a timing controller) can receive input image data IDAT and control signal CTRL from an external host processor (e.g., a graphics processing unit (“GPU”), application processor (“AP”), or graphics card). In some embodiments, the input image data IDAT may be RGB image data, including red, green, and blue image data. Furthermore, in some embodiments, the control signal CTRL may include, but is not limited to, a vertical synchronization signal, a horizontal synchronization signal, a data enable signal, a master clock signal, etc. Controller 190 can generate output image data ODAT, a data control signal DCTRL, and a scan control signal SCTRL based on the input image data IDAT and the control signal CTRL. Controller 190 can control the operation of scan driver 130 by providing the scan control signal SCTRL to scan driver 130, and can control the operation of data driver 140 by providing the output image data ODAT and the data control signal DCTRL to data driver 140.

[0075] The host processor can provide input image data IDAT to the display device 100 at a variable frequency VF (or variable frame rate) by changing the length of the blank period in each frame cycle. The controller 190 can receive the input image data IDAT from the host processor at a variable frequency VF. Furthermore, in the display device 100 according to the embodiment, the controller 190 can control the scan driver 130 and the data driver 140 to drive the display panel 110 at a variable frequency VF. In some embodiments, the mode in which the display panel 110 of the display device 100 is driven at a variable frequency VF (or variable frame rate) can be referred to as a variable frame mode. For example, the variable frame mode can be, but is not limited to, Free-Sync mode, G-Sync mode, etc.

[0076] For example, such as Figure 3 As shown, the period or frequency of rendering 210, 220, and 230 performed by the host processor (e.g., GPU, AP, or graphics card) may not be constant (e.g., it may not be constant in the case of rendering game image data). The host processor can provide input image data IDAT (or frame data FD1, FD2, and FD3) to the display device 100 in a variable frame mode in synchronization with these irregular periods or frequencies of rendering 210, 220, and 230. Therefore, in a variable frame mode, each frame period FP1, FP2, and FP3 may include constant effective periods AP1, AP2, and AP3 with constant duration, and the host processor can provide frame data FD1, FD2, and FD3 to the display device 100 at a variable frequency VF by changing the duration of the blank periods BP1, BP2, and BP3 of each frame period FP1, FP2, and FP3. Figure 3 In the example, if rendering 210 for the second frame data FD2 is performed at a frequency of approximately 240Hz in the first frame period FP1, the host processor can provide the first frame data FD1 to the display device 100 at a variable frequency VF of approximately 240Hz in the first frame period FP1. Furthermore, the host processor can output the second frame data FD2 during the effective period AP2 of the second frame period FP2, and can continue the blank period BP2 of the second frame period FP2 until the rendering 220 for the third frame data FD3 is completed. Therefore, if rendering 220 for the third frame data FD3 is performed at a frequency of approximately 48Hz in the second frame period FP2, the host processor can provide the second frame data FD2 to the display device 100 at a variable frequency VF of approximately 48Hz by increasing the duration of the blank period BP2 of the second frame period FP2. In the third frame period FP3, if rendering 230 for the fourth frame data FD4 is again performed at a frequency of approximately 240Hz, the host processor can again provide the third frame data FD3 to the display device 100 at a variable frequency VF of approximately 240Hz.

[0077] When the display panel is driven at different frequencies, a conventional display device operating in a variable frame mode may have different brightness levels. This is because the light-emitting element of each pixel is initialized in each frame cycle, and because the light-emitting element does not emit light when it is initialized, such as... Figure 4 As shown, during the same time period, the number of luminance valleys (or the number of non-emissions per pixel) in a display panel driven at approximately 120Hz can be reduced compared to the number of luminance valleys in a display panel driven at approximately 240Hz, and the average luminance AVGLUM2 of the display panel driven at approximately 120Hz can be higher than the average luminance AVGLUM1 of the display panel driven at approximately 240Hz. Due to this difference in luminance based on the driving frequency, flickering may occur in conventional display devices when the driving frequency changes. Furthermore, as... Figure 4 As shown, in conventional display devices, overshoot (OVS) can occur, where the brightness of the display panel undesirably increases in the first frame cycle immediately following a change in the driving frequency. Furthermore, flicker and OVS may worsen as the non-emission time of the light-emitting elements increases during initialization.

[0078] However, in the display device 100 according to the embodiment, the initialization voltage VINT and the second power supply voltage ELVSS can be set such that the voltage difference between the initialization voltage VINT and the second power supply voltage ELVSS is close to the turn-on voltage of the light-emitting element LED (e.g., the average or lowest turn-on voltage of the light-emitting elements LED of a plurality of pixels PX). Therefore, the non-emission time of the light-emitting element LED when it is initialized can be reduced. In some embodiments, the initialization voltage VINT can be set to a positive voltage, and the second power supply voltage ELVSS can be set to a negative voltage.

[0079] For example, such as Figure 5 As shown, in a conventional display device, the panel driver 260 may include a first voltage generator 270 that provides a first power supply voltage ELVDD (e.g., a high power supply voltage) to the first power supply voltage line ELVDDL of the display panel 250, but may not include a second voltage generator that generates a second power supply voltage (e.g., a low power supply voltage). In a conventional display device, the ground voltage VGND can be used as the second power supply voltage. That is, the panel driver 260 can provide the ground voltage VGND to the second power supply voltage line ELVSSL of the display panel 250, and the ground voltage VGND can be applied to the cathode of the light-emitting element of each pixel.

[0080] However, in the display device 100 according to the embodiment, the panel driver 120 may include not only a first voltage generator 170 that generates a positive first power supply voltage ELVDD based on a first input voltage VIN1, but also a second voltage generator 180 that generates a negative second power supply voltage ELVSS based on a negative first input voltage VIN1. The panel driver 120 can provide the first power supply voltage ELVDD to the first power supply voltage line ELVDDL of the display panel 110, and can provide the second power supply voltage ELVSS, which is a negative voltage VNEG, to the second power supply voltage line ELVSSL of the display panel 110. That is, in the display device 100 according to the embodiment, the negative voltage VNEG can be used instead of the ground voltage VGND as the second power supply voltage ELVSS.

[0081] When using a negative voltage VNEG as the second power supply voltage ELVSS, the non-emission time of the LED during initialization in each frame cycle can be reduced. For example, as... Figure 6 As shown, when the second power supply voltage ELVSS of the second power supply voltage line ELVSSL is reduced from approximately 0V ground voltage VGND to approximately -2V negative voltage VNEG, the voltage of the source node NS of each pixel PX before the light-emitting element LED is initialized can also be reduced. Furthermore, when an initialization voltage VINT of approximately 6.7V is applied to the source node NS in response to the sensing signal SS, the light-emitting element LED of each pixel PX can be initialized based on the initialization voltage VINT applied to the anode of the light-emitting element LED and based on the second power supply voltage ELVSS applied to the cathode of the light-emitting element LED. Compared to the case where approximately 0V ground voltage VGND is used as the second power supply voltage ELVSS, when the approximately -2V negative voltage VNEG is used as the second power supply voltage ELVSS, the voltage difference VINT-ELVSS between the initialization voltage VINT and the second power supply voltage ELVSS can be closer to the LED's turn-on voltage VEL_ON. In this case, the degree of discharge of the parasitic capacitor of the light-emitting element LED can be reduced. Therefore, compared to the non-emission time LVT1 of the LED when it is initialized with a ground voltage of approximately 0V VGND as the second power supply voltage ELVSS, the non-emission time LVT2 of the LED when it is initialized with a negative voltage of approximately -2V VNEG as the second power supply voltage ELVSS can be reduced. If the non-emission time LVT2 of the LED is reduced, the amount or size of the brightness trough in the display panel 110 can be reduced, and flicker and brightness overshoot OVS during driving frequency changes can be reduced.

[0082] As described above, in order to reduce the non-emission time LVT2 of the light-emitting element LED, in the display device 100 according to the embodiment, the initialization voltage VINT and the second power supply voltage ELVSS can be set such that the voltage difference VINT-ELVSS between the initialization voltage VINT and the second power supply voltage ELVSS is smaller than the turn-on voltage VEL_ON of the light-emitting element LED by a margin voltage (e.g., a predetermined margin voltage) VMAR. For example, as Figure 6 As shown, the initialization voltage VINT can be set to approximately 6.7V, and the second supply voltage ELVSS can be set to approximately -2V, such that the voltage difference VINT-ELVSS between the initialization voltage VINT and the second supply voltage ELVSS is a margin voltage VMAR of approximately 0.3V smaller than the approximately 9V turn-on voltage VEL_ON. However, the initialization voltage VINT and the second supply voltage ELVSS are not limited to... Figure 6 Examples. Furthermore, in some embodiments, a negative voltage VNEG can be used instead of the ground voltage VGND as the second power supply voltage ELVSS. In this case, even if the initialization voltage VINT is not increased, or even if the sensing circuit 150 and / or power management circuit 160 are not redesigned to increase the initialization voltage VINT, the voltage difference VINT-ELVSS between the initialization voltage VINT and the second power supply voltage ELVSS can become close to the turn-on voltage VEL_ON of the light-emitting element LED. Furthermore, in the display device 100 according to the embodiment, since the voltage difference VINT-ELVSS between the initialization voltage VINT and the second power supply voltage ELVSS is close to the turn-on voltage VEL_ON of the light-emitting element LED, the non-emission time LVT2 of the light-emitting element LED when it is initialized can be reduced, and flickering and luminance overshoot OVS during driving frequency changes can be reduced.

[0083] Figure 7 This is a block diagram illustrating a portion of a display device according to an embodiment, and Figure 8 This is a timing diagram illustrating an example of the power sequence of a display device according to an embodiment.

[0084] refer to Figure 7 The display device 100a according to the embodiment may include a display panel 110 and a panel driver 120a. The panel driver 120a may include a power management circuit 160a, a first voltage generator 170, a second voltage generator 180a, and a controller 190a. Figure 7In the display device 100a, the second voltage generator 180a can provide a second power supply voltage ELVSS, which is a negative voltage, to the second power supply voltage line ELVSSL during the drive cycle, and the power management circuit 160a can provide a positive voltage VPOS to the second power supply voltage line ELVSSL during the sensing cycle.

[0085] The first voltage generator 170 can generate a first power supply voltage ELVDD based on the first input voltage VIN1, and can provide the first power supply voltage ELVDD to the first power supply voltage line ELVDDL of the display panel 110. The second voltage generator 180a can receive a negative voltage enable signal NELVSS_EN from the controller 190a, and can generate a second power supply voltage ELVSS as a negative voltage based on the first input voltage VIN1 in response to the negative voltage enable signal NELVSS_EN, and can provide the second power supply voltage ELVSS to the second power supply voltage line ELVSSL of the display panel 110.

[0086] In some implementations, such as Figure 8 As shown, during the power-on cycle PON of the display device 100a, the second power supply voltage ELVSS can be activated first, and the first power supply voltage ELVDD can be activated after the second power supply voltage ELVSS is activated. Therefore, unwanted light emission from the light-emitting element when the second power supply voltage ELVSS is activated can be reduced or prevented.

[0087] Furthermore, during the drive cycle PDR of the display panel 110 displaying the image, the first voltage generator 170 can provide the first power supply voltage ELVDD to the first power supply voltage line ELVDDL of the display panel 110, the initialization voltage generator 162a of the power management circuit 160a can provide the initialization voltage VINT to the display panel 110, and the second voltage generator 180a can provide the second power supply voltage ELVSS to the second power supply voltage line ELVSSL of the display panel 110.

[0088] Furthermore, during the power-off cycle POFF of the display device 100a, the first power supply voltage ELVDD can be disabled first, and the second power supply voltage ELVSS can be disabled after the first power supply voltage ELVDD is disabled.

[0089] The power management circuit 160a may include not only an initialization voltage generator 162a that generates an initialization voltage VINT based on a second input voltage VIN2, but also a positive voltage generator 164a that generates a positive voltage VPOS in response to a positive voltage enable signal PELVSS_EN received from the controller 190a. In some embodiments, each of the initialization voltage generator 162a and the positive voltage generator 164a may include a linear regulator, but is not limited thereto.

[0090] like Figure 8 As shown, during the drive cycle PDR of the display panel 110 displaying an image, the controller 190a can generate a positive voltage enable signal PELVSS_EN with a cutoff level (e.g., low level) and a negative voltage enable signal NELVSS_EN with a conduction level (e.g., high level). Therefore, the second voltage generator 180a can, in response to the negative voltage enable signal NELVSS_EN with a conduction level, provide a negative second power supply voltage ELVSS to the second power supply voltage line ELVSSL of the display panel 110, and the second power supply voltage ELVSS generated by the second voltage generator 180a can be provided to the cathode of the light-emitting element of each pixel of the display panel 110.

[0091] Conversely, during the sensing cycle PSEN, which performs the sensing operation, controller 190a can generate a positive voltage enable signal PELVSS_EN with an on level and a negative voltage enable signal NELVSS_EN with an off level. Therefore, the positive voltage generator 164a of power management circuit 160a can provide a positive voltage VPOS to the second power supply voltage line ELVSSL of display panel 110, and the positive voltage VPOS generated by positive voltage generator 164a can be provided to the cathode of the light-emitting element of each pixel of display panel 110. Therefore, during the sensing cycle PSEN, the light-emitting element of each pixel may not emit light.

[0092] Figure 9 This is a flowchart illustrating a method for determining an acceptable voltage level (e.g., a suitable voltage level or an optimal voltage level) for a second power supply voltage for a display device according to an embodiment. Figure 10 This is a block diagram showing a portion of a display device according to an embodiment.

[0093] refer to Figure 9 and Figure 10 An acceptable voltage level (e.g., optimal voltage level) OVL for the second power supply voltage ELVSS can be determined for each of the plurality of display devices 100b, and each display device 100b can generate a second power supply voltage ELVSS having an acceptable voltage level OVL determined for each display device 100b.

[0094] When manufacturing each display device 100b, the voltage level of the second power supply voltage ELVSS can be gradually reduced from an initial voltage level (e.g., about 0V) (S310), and the brightness of the display panel 110 can be measured (S330). If the brightness of the display panel 110 is about 0 nits (S350: Yes), or if the light-emitting element of each pixel of the display panel 110 does not emit light, the voltage level of the second power supply voltage ELVSS can be reduced again (S310), and the brightness of the display panel 110 can be measured again (S330).

[0095] If the brightness of the display panel 110 is greater than about 0 nits (S350: No), or if the light-emitting element of each pixel of the display panel 110 emits light, the acceptable voltage level OVL of the second power supply voltage ELVSS can be determined, and the acceptable voltage level OVL can be stored in the acceptable power supply voltage storage (e.g., optimal power supply voltage storage or suitable power supply voltage storage) 195b of the display device 100b (S370). In some embodiments, the acceptable voltage level OVL of the second power supply voltage ELVSS can be determined by increasing a margin voltage (e.g., a predetermined margin voltage) to the second power supply voltage ELVSS when the brightness of the display panel 110 is greater than about 0 nits, but is not limited thereto.

[0096] When each display device 100b is driven, the controller 190b of the panel driver 120b can provide the second voltage generator 180b with an acceptable voltage level OVL stored in the acceptable power voltage storage 195b. In some embodiments, the acceptable power voltage storage 195b may be included in the controller 190b, but is not limited thereto. The second voltage generator 180b can generate a second power supply voltage ELVSS with an acceptable voltage level OVL based on the first input voltage VIN1, and can provide the second power supply voltage ELVSS with an acceptable voltage level OVL to the second power supply voltage line ELVSSL of the display panel 110. Therefore, second power supply voltages ELVSS with different voltage levels can be generated in multiple display devices 100b, and each display device 100b can generate a second power supply voltage ELVSS that is acceptable (e.g., suitable or optimal) for each display device 100b.

[0097] Figure 11 This is a block diagram illustrating a portion of a display device according to an embodiment, and Figure 12 This is a diagram illustrating an example of a second power supply voltage based on temperature in a display device according to an embodiment.

[0098] refer to Figure 11The display device 100c according to the embodiment may include a display panel 110 and a panel driver 120c. The panel driver 120c may include a first voltage generator 170, a second voltage generator 180c, a controller 190c, a temperature sensor 192c, and a temperature-second power supply voltage lookup table 194c. Figure 11 In the display device 100c, the voltage level TVL of the second power supply voltage ELVSS can be adjusted according to the temperature.

[0099] Temperature sensor 192c can measure the temperature of display panel 110 and provide a temperature signal STEMP to controller 190c, the temperature signal STEMP indicating the temperature of display panel 110. Temperature-second power supply voltage lookup table 194c can store the voltage level TVL of the second power supply voltage ELVSS corresponding to each of a plurality of temperatures. Controller 190c can determine the voltage level TVL of the second power supply voltage ELVSS corresponding to the temperature indicated by temperature signal STEMP by using temperature-second power supply voltage lookup table 194c, and can provide the voltage level TVL of the second power supply voltage ELVSS corresponding to the temperature to second voltage generator 180c. In some embodiments, such as Figure 12 As shown, when the temperature of the display panel 110 increases, the voltage level TVL of the second power supply voltage ELVSS can increase, but is not limited to this. Furthermore, according to the embodiment, the temperature-second power supply voltage lookup table 194c can be located inside or outside the controller 190c. The second voltage generator 180c can generate a second power supply voltage ELVSS with a temperature-corresponding voltage level TVL based on the first input voltage VIN1, and can provide the second power supply voltage ELVSS with a temperature-corresponding voltage level TVL to the second power supply voltage line ELVSSL of the display panel 110. Therefore, the brightness of the display panel 110 can be reduced or prevented from increasing as the temperature of the display panel 110 increases.

[0100] Figure 13 This is a block diagram illustrating a portion of a display device according to an embodiment, and Figure 14 This is a diagram illustrating an example of a second power supply voltage according to the driving time in a display device according to an embodiment.

[0101] refer to Figure 13 The display device 100d according to the embodiment may include a display panel 110 and a panel driver 120d. The panel driver 120d may include a first voltage generator 170, a second voltage generator 180d, and a controller 190d including a drive time accumulator 195d. Figure 13In the display device 100d, the voltage level DTVL of the second power supply voltage ELVSS can be adjusted according to the driving time of the display panel 110.

[0102] The drive time accumulator 195d can accumulate the drive time of the display panel 110. In some embodiments, the drive time accumulator 195d can accumulate the drive time of the display panel 110 by accumulating the input image data IDAT, but it is not limited to this. The controller 190d can determine the voltage level DTVL of the second power supply voltage ELVSS based on the drive time of the display panel 110, and can provide the voltage level DTVL corresponding to the drive time to the second voltage generator 180d. In some embodiments, such as Figure 14 As shown, as the driving time of the display panel 110 increases, the voltage level DTVL of the second power supply voltage ELVSS can decrease, but is not limited thereto. The second voltage generator 180d can generate a second power supply voltage ELVSS with a voltage level DTVL corresponding to the driving time based on the first input voltage VIN1, and can provide the second power supply voltage ELVSS with a voltage level DTVL corresponding to the driving time to the second power supply voltage line ELVSSL of the display panel 110. Therefore, the brightness of the display panel 110 can be reduced or prevented from decreasing as the driving time of the display panel 110 increases.

[0103] Figure 15 This is a flowchart illustrating a method for determining an acceptable voltage level (e.g., an optimal voltage level) for the initialization voltage of a display device according to an embodiment, and Figure 16 This is a block diagram showing a portion of a display device according to an embodiment.

[0104] refer to Figure 15 and Figure 16 A second power supply voltage ELVSS, which is substantially the same negative voltage, can be used in multiple display devices 100e. An acceptable voltage level (e.g., optimal voltage level) OVL for an initialization voltage VINT can be determined for each of the multiple display devices 100e. Each display device 100e can generate a second power supply voltage ELVSS, which is substantially the same negative voltage, and can generate an initialization voltage VINT with an acceptable voltage level OVL determined for each display device 100e.

[0105] When manufacturing each display device 100e, a substantially identical negative voltage can be generated for the multiple display devices 100e as a second power supply voltage ELVSS (S410). The voltage level of the initialization voltage VINT can be increased (e.g., gradually increased) from the initial voltage level (S430), and the brightness of the display panel 110 can be measured (S450). If the brightness of the display panel 110 is approximately 0 nits (S470: Yes), or if the light-emitting elements of each pixel of the display panel 110 do not emit light, the voltage level of the initialization voltage VINT can be increased again (S430), and the brightness of the display panel 110 can be measured again (S450).

[0106] If the brightness of the display panel 110 is greater than approximately 0 nits (S470: No), or if the light-emitting element of each pixel of the display panel 110 emits light, the acceptable voltage level OVL of the initialization voltage VINT can be determined, and the acceptable voltage level OVL can be stored in the acceptable initialization voltage storage (e.g., optimal initialization voltage storage) 195e of the display device 100e (S490). In some embodiments, the acceptable voltage level OVL of the initialization voltage VINT can be determined by subtracting a margin voltage (e.g., a predetermined margin voltage) from the initialization voltage VINT when the brightness of the display panel 110 is greater than approximately 0 nits, but is not limited thereto.

[0107] When each display device 100e is driven, the controller 190e of the panel driver 120e can provide the power management circuit 160e with an acceptable voltage level OVL stored in the acceptable initialization voltage storage 195e. In some embodiments, the acceptable initialization voltage storage 195e may be included in the controller 190e, but is not limited thereto. The second voltage generator 180 can generate a negative voltage that is substantially the same for the plurality of display devices 100e as a second power supply voltage ELVSS based on the first input voltage VIN1. The power management circuit 160e can generate an initialization voltage VINT with an acceptable voltage level OVL based on the second input voltage VIN2, and the sensing circuit 150e can provide the initialization voltage VINT with an acceptable voltage level OVL to the second power supply voltage line ELVSSL of the display panel 110. Therefore, initialization voltages VINT with different voltage levels can be generated in the plurality of display devices 100e, and each display device 100e can generate an initialization voltage VINT that is acceptable (e.g., suitable or optimal) for each display device 100e.

[0108] Figure 17 This is a block diagram illustrating a display device according to an embodiment, and Figure 18This is a timing diagram illustrating an example of the sensing signal for each pixel, the voltage of the source node, and the voltage of the second power supply voltage line in a display device according to an embodiment.

[0109] refer to Figure 17 The display device 500 according to the embodiment may include a display panel 510 and a panel driver 520. The panel driver 520 may include a scan driver 530, a data driver 540, a sensing circuit 550, a power management circuit 560, a first voltage generator 570, and a controller 590. The panel driver 520 may not be included. Figure 1 The second voltage generator 180 shown can provide the ground voltage VGND to the second power supply voltage line ELVSSL, and the power management circuit 560 can generate a voltage higher than the ground voltage VGND. Figure 1 Apart from the initialization voltage VINT' shown, which is higher than the initialization voltage VINT, Figure 17 The display device 500 can have the same as Figure 1 The display device 100 has a similar configuration and similar operation.

[0110] The panel driver 520 can provide a ground voltage VGND to the second power supply voltage line ELVSSL, and each pixel PX can receive the ground voltage VGND as the second power supply voltage. That is, in the display device 500, the ground voltage VGND can be used as the second power supply voltage.

[0111] The power management circuit 560 can generate ratios Figure 1 The initialization voltage VINT' shown is a higher initialization voltage VINT'. In some embodiments, the initialization voltage VINT' generated by the power management circuit 560 can be a voltage obtained by subtracting a margin voltage from the turn-on voltage of the light-emitting element of each pixel PX.

[0112] For example, such as Figure 18As shown, the power management circuit 560 can generate an initialization voltage VINT' that is higher than the initialization voltage VINT, which is approximately 6.7V. In one example, the turn-on voltage VEL_ON of the light-emitting element can be, but is not limited to, approximately 9V, the margin voltage VMAR can be, but is not limited to, approximately 0.3V, and the initialization voltage VINT' can be, but is not limited to, approximately 8.7V. In this case, the voltage difference VINT'-ELVSS between the initialization voltage VINT' and the second power supply voltage ELVSS can be close to the turn-on voltage VEL_ON of the light-emitting element. Therefore, the non-emission time LVT3 of the light-emitting element when it is initialized with a relatively low initialization voltage VINT' can be reduced. If the non-emission time LVT4 of the light-emitting element is reduced, flickering and brightness overshoot during drive frequency changes can be reduced.

[0113] Figure 19 This is a block diagram illustrating an electronic device including a display device according to an embodiment.

[0114] refer to Figure 19 Electronic device 1100 may include a processor 1110, a memory device 1120, a storage device 1130, an input / output (I / O) device 1140, a power supply 1150, and a display device 1160. Electronic device 1100 may also include multiple ports for communicating with video cards, sound cards, memory cards, universal serial bus (“USB”) devices, other electronic devices, etc.

[0115] Processor 1110 can perform various computing functions or tasks. Processor 1110 can be an application processor (“AP”), a microprocessor, a central processing unit (“CPU”), etc. Processor 1110 can be connected to other components via address buses, control buses, data buses, etc. In addition, in some embodiments, processor 1110 can also be connected to an expansion bus, such as a peripheral component interconnect (“PCI”) bus.

[0116] The memory device 1120 can store data for the operation of the electronic device 1100. For example, the memory device 1120 may include: at least one non-volatile memory device, such as an erasable programmable read-only memory (“EPROM”) device, an electrically erasable programmable read-only memory (“EEPROM”) device, a flash memory device, a phase-change random access memory (“PRAM”) device, a resistive random access memory (“RRAM”) device, a nano-floating gate memory (“NFGM”) device, a polymer random access memory (“PoRAM”) device, a magnetic random access memory (“MRAM”) device, a ferroelectric random access memory (“FRAM”) device, etc.; and / or at least one volatile memory device, such as a dynamic random access memory (“DRAM”) device, a static random access memory (“SRAM”) device, a mobile dynamic random access memory (“mobile DRAM”) device, etc.

[0117] Storage device 1130 may be a solid-state drive (“SSD”) device, a hard disk drive (“HDD”) device, an optical disc read-only memory (“CD-ROM”) device, etc. I / O device 1140 may be an input device such as a keyboard, keypad, mouse, touchscreen, etc., and an output device such as a printer, speaker, etc. Power supply 1150 provides power for the operation of electronic device 1100. Display device 1160 can be connected to other components via a bus or other communication link.

[0118] In the display device 1160, the light-emitting element of each pixel can be initialized based on an initialization voltage applied to the anode of the light-emitting element and a second power supply voltage applied to the cathode of the light-emitting element. The initialization voltage and the second power supply voltage can be set such that the voltage difference between them is less than the turn-on voltage of the light-emitting element by a margin. In other words, the voltage difference between the initialization voltage and the second power supply voltage can be close to the turn-on voltage of the light-emitting element. Therefore, the non-emission time of the light-emitting element during initialization can be reduced, and flickering can be reduced when the driving frequency changes.

[0119] The disclosed embodiments can be applied to any electronic device 1100 including the display device 1160. For example, the disclosed embodiments can be applied to mobile phones, smartphones, virtual reality (“VR”) devices, televisions (“TV”) (e.g., digital TV, 3D TV, etc.), wearable electronic devices, personal computers (“PC”) (e.g., laptop computers, tablet computers, etc.), home appliances, personal digital assistants (“PDAs”), portable multimedia players (“PMPs”), digital cameras, music players, portable game consoles, navigation devices, etc.

[0120] According to one or more embodiments, the display devices of the disclosed embodiments (e.g., display devices 100, 100a, 100b, 100c, 100d, 100e, 500, 1160) are devices for displaying moving images and / or still images. The display devices can be applied to portable electronic devices such as mobile phones, smartphones, tablet PCs, mobile communication terminals, e-notebooks, e-readers, portable multimedia players (PMPs), navigation devices, and ultra-mobile PCs (UMPCs). For example, the display devices can be applied to the display units of televisions, laptop computers, monitors, billboards, or Internet of Things (IoT) devices. Optionally, in one or more embodiments, the display devices can be applied to smartwatches, watch phones, and / or head-mounted display devices (HMDs) for implementing virtual reality and / or augmented reality.

[0121] The foregoing is illustrative of embodiments and should not be construed as limiting them. Although multiple embodiments have been described, those skilled in the art will readily understand that many modifications can be made to the embodiments without substantially departing from the novel teachings and advantages of this disclosure. Therefore, all such modifications are intended to be included within the scope of this disclosure as defined in the claims. It will thus be understood that the foregoing is illustrative of various embodiments and should not be construed as limiting to the specific embodiments disclosed, and modifications to the disclosed embodiments, as well as other embodiments, are intended to be included within the scope of the appended claims, and their functional equivalence will be included within the scope of the appended claims.

Claims

1. A display device, comprising: A display panel includes a data line, a sensing line, and pixels, wherein the pixels are connected to the data line and the sensing line and include light-emitting elements; as well as A panel driver is configured to provide scan signals and sensing signals to the pixels, provide data voltage to the pixels via the data lines, provide an initialization voltage to the anode of the light-emitting element via the sensing lines, provide a first power supply voltage to the pixels, and provide a second power supply voltage to the cathode of the light-emitting element of the pixels. The light-emitting element is configured to be initialized based on the initialization voltage and the second power supply voltage, wherein the voltage difference between the initialization voltage and the second power supply voltage is a margin smaller than the turn-on voltage of the light-emitting element.

2. The display device according to claim 1, wherein, The initialization voltage is positive, and the second power supply voltage is negative.

3. The display device according to claim 1, wherein, The initialization voltage is equal to the on-state voltage of the light-emitting element minus the margin voltage, and Wherein, the second power supply voltage is equal to the ground voltage.

4. The display device according to claim 1, wherein, The pixels include: A capacitor, comprising a first electrode connected to a gate node and a second electrode connected to a source node; The first transistor includes a gate connected to the gate node, a first terminal configured to receive the first power supply voltage, and a second terminal connected to the source node; A second transistor is configured to connect a corresponding data line in the data lines to the gate node in response to the scan signal; A third transistor is configured to connect a corresponding sensing line in the sensing line to the source node in response to the sensing signal; and The light-emitting element includes the anode connected to the source node and the cathode configured to receive the second power supply voltage.

5. The display device according to claim 1, wherein, The panel driver includes: A first voltage generator is configured to generate a first power supply voltage based on a first input voltage, wherein the first power supply voltage is positive; and A second voltage generator is configured to generate a second power supply voltage based on the first input voltage, wherein the second power supply voltage is negative.

6. The display device according to claim 5, wherein, During the power-on cycle of the display device, the second power supply voltage is configured to be activated, and the first power supply voltage is configured to be activated after the second power supply voltage is activated.

7. The display device according to claim 5, wherein, During the power-off cycle of the display device, the first power supply voltage is configured to be disabled, and the second power supply voltage is configured to be disabled after the first power supply voltage is disabled.

8. A display device, comprising: The display panel includes a data line, a sensing line, and pixels connected to the data line and the sensing line; A scan driver configured to provide scan signals and sensing signals to the pixels; A data driver configured to provide a data voltage to the pixel via the data line; A first voltage generator is configured to provide a first power supply voltage to the pixel; A second voltage generator is configured to provide a negative second power supply voltage to the pixel; The power management circuit is configured to generate a positive initial voltage; A sensing circuit is configured to provide the initialization voltage to the pixel through the sensing line during a driving cycle, and to perform a sensing operation on the pixel through the sensing line during a sensing cycle; as well as The controller is configured to control the scan driver, the data driver, the first voltage generator, the second voltage generator, the power management circuit, and the sensing circuit. The pixels include: A capacitor, comprising a first electrode connected to a gate node and a second electrode connected to a source node; The first transistor includes a gate connected to the gate node, a first terminal configured to receive the first power supply voltage, and a second terminal connected to the source node; A second transistor is configured to connect a corresponding data line in the data lines to the gate node in response to the scan signal; A third transistor is configured to connect a corresponding sensing line in the sensing line to the source node in response to the sensing signal; and The light-emitting element includes an anode connected to the source node and a cathode configured to receive the second power supply voltage.

9. A display device, comprising: A display panel includes a data line, a sensing line, and pixels, wherein the pixels are connected to the data line and the sensing line and include light-emitting elements; as well as A panel driver is configured to provide scan signals and sensing signals to the pixels, provide data voltages to the pixels via the data lines, provide a positive initialization voltage to the anode of the light-emitting element via the sensing lines, provide a first power supply voltage, and provide a negative second power supply voltage to the cathode of the light-emitting element. The light-emitting element is configured to be initialized based on the initialization voltage and the second power supply voltage.

10. An electronic device, including a display device, said display device comprising: A display panel includes data lines, sensing lines, and pixels, wherein the pixels are connected to the data lines and sensing lines and include light-emitting elements; as well as A panel driver is configured to provide scan signals and sensing signals to the pixels, provide data voltage to the pixels via the data lines, provide an initialization voltage to the anode of the light-emitting element via the sensing lines, provide a first power supply voltage to the pixels, and provide a second power supply voltage to the cathode of the light-emitting element of the pixels. The light-emitting element is configured to be initialized based on the initialization voltage and the second power supply voltage, wherein the voltage difference between the initialization voltage and the second power supply voltage is a margin smaller than the turn-on voltage of the light-emitting element.

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