Display device

Abstract

The application relates to a display device including a driving controller that determines whether a dimming value is within one of a first range and a second range; in response to determining that the dimming value is within the first range, comparing the dimming value with the first value; and operating in one of a first mode and a second mode in response to a comparison result of the dimming value and the first value; in response to determining that the dimming value is within the second range, comparing the dimming value with the second value; and operating in one of a first mode and a second mode in response to a comparison result of the dimming value and the second value; in the first mode, a light-emitting control signal for adjusting the pulse width of a light-emitting signal is output. And outputting the output data signal by modifying the input image signal based on the dimming value in the second mode.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the priority of Korean Patent Application No. 10-2023-0153041 filed in the Korean Intellectual Property Office on November 7, 2023, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] Embodiments of the present disclosure described herein relate to a display device and a method for driving the display device, and more particularly, to a display device capable of improving display quality and a method for driving the display device. Background Art

[0004] The display device includes a display panel and a panel driver. The display panel includes scan lines, data lines and pixels. The panel driver includes a scan driver for applying scan signals to the scan lines and a data driver for applying data signals to the data lines. Each of the pixels can emit light having a brightness corresponding to the data signal applied through the relevant data line in response to the scan signal applied through the relevant scan line.

[0005] The data driving circuit may convert the data signal into a data signal corresponding to the gray levels using gamma voltages corresponding to a plurality of gray levels. Summary of the invention

[0006] Embodiments of the present disclosure described herein provide a display device and a method for driving the display device capable of overcoming the problem of deteriorating display quality after dimming.

[0007] According to aspects of the present disclosure, a display device includes: a display panel; a drive controller configured to modify an input image signal, output an output data signal, and generate a light emitting control signal; a data driving circuit configured to convert the output data signal into a data signal based on a plurality of gamma voltages and apply the data signal to the display panel; and a light emitting driving circuit configured to provide a light emitting signal to the display panel in response to the light emitting control signal. The driving controller is configured to: determine whether an input dimming code value is within one of a plurality of dimming ranges including a first dimming range and a second dimming range; in response to determining that the input dimming code value is within the first dimming range, compare the input dimming code value with a first reference dimming code value, and in response to a comparison result of the input dimming code value and the first reference dimming code value, operate in one of a first brightness control mode and a second brightness control mode; in response to determining that the input dimming code value is within the second dimming range, compare the input dimming code value with a second reference dimming code value, and in response to a comparison result of the input dimming code value and the second reference dimming code value, operate in one of the first brightness control mode and the second brightness control mode; in the first brightness control mode, output a light emitting control signal for adjusting a pulse width of a light emitting signal; and in the second brightness control mode, output an output data signal by modifying an input image signal based on the input dimming code value.

[0008] According to an embodiment, the display device may further include: a gamma voltage generator that generates a plurality of gamma voltages in response to a first voltage code value. The drive controller is configured to generate a first voltage code value based on an output data signal. The first voltage code value includes a bottom voltage code value for determining a voltage level of a first gamma reference voltage and a top voltage code value for determining a voltage level of a second gamma reference voltage. The plurality of gamma voltages are between the first gamma reference voltage and the second gamma reference voltage.

[0009] According to an embodiment, the driving controller may update the first voltage code value to the second voltage code value based on a difference between a highest dimming gray value of the output data signal and a preset highest reference gray value in the second brightness control mode.

[0010] According to an embodiment, the driving controller may update the first voltage code value to the second voltage code value in response to a difference between the highest dimming gray value and the highest reference gray value being greater than a preset reference difference.

[0011] According to an embodiment, the driving controller may maintain the voltage code value in response to a difference between the highest dimming gray value and the highest reference gray value being equal to or less than a preset reference difference.

[0012] According to an embodiment, the driving controller may output a light emitting control signal in the first brightness control mode to generate a light emitting signal having a pulse width corresponding to the input dimming code value.

[0013] According to an embodiment, the driving controller may operate in the first brightness control mode in response to the input dimming code value being less than the first reference dimming code value, and operate in the second brightness control mode in response to the input dimming code value being greater than or equal to the first reference dimming code value.

[0014] According to an embodiment, the driving controller may operate in the first brightness control mode in response to the input dimming code value being less than the second reference dimming code value, and operate in the second brightness control mode in response to the input dimming code value being greater than or equal to the second reference dimming code value.

[0015] According to an embodiment, the first reference dimming code value may be one of a plurality of dimming code values ​​included in the first dimming range, and the second reference dimming code value may be one of a plurality of dimming code values ​​included in the second dimming range.

[0016] According to an embodiment, the display panel may include pixels operating in response to a data signal and a light emitting signal.

[0017] According to an embodiment, the driving controller may include: a controller outputting input data obtained by converting an input image signal into grayscale input data and outputting an input dimming code value and a voltage code value; and a data converter outputting an output data signal based on the input data and the input dimming code value.

[0018] According to aspects of the present disclosure, a method for driving a display device includes: determining whether an input dimming code value is within one of a plurality of dimming ranges including a first dimming range and a second dimming range; in response to determining that the input dimming code value is within the first dimming range, comparing the input dimming code value with a first reference dimming code value, and operating in one of a first brightness control mode and a second brightness control mode in response to a comparison result between the input dimming code value and the first reference dimming code value; in response to determining that the input dimming code value is within the second dimming range, comparing the input dimming code value with a second reference dimming code value, and operating in one of the first brightness control mode and the second brightness control mode in response to a comparison result between the input dimming code value and the second reference dimming code value.

[0019] According to an embodiment, the method may further include: generating a plurality of gamma voltages in response to the first voltage code value; and converting the output data signal into a data signal based on the plurality of gamma voltages, and providing the data signal to the display panel.

[0020] According to an embodiment, the method may further include: in the second brightness control mode, in response to the difference between the highest dimming grayscale value of the output data signal and the preset highest reference grayscale value being greater than a preset reference difference, updating the first voltage code value to a second voltage code value.

[0021] According to an embodiment, the method may further include: in the second brightness control mode, in response to a difference between the highest dimming grayscale value and a preset highest reference grayscale value being equal to or less than a preset reference difference, maintaining the first voltage code value.

[0022] According to an embodiment, the method may further include: in the first brightness control mode, generating a light emitting signal having a pulse width corresponding to the input dimming code value.

[0023] According to an embodiment, operation in one of the first brightness control mode and the second brightness control mode in response to a comparison result between an input dimming code value and a first reference dimming code value may include: operating in the first brightness control mode in response to the input dimming code value being less than the first reference dimming code value; and operating in the second brightness control mode in response to the input dimming code value being greater than or equal to the first reference dimming code value.

[0024] According to an embodiment, operating in one of the first brightness control mode and the second brightness control mode in response to a comparison result between an input dimming code value and a second reference dimming code value may include: operating in the first brightness control mode in response to the input dimming code value being less than the second reference dimming code value; and operating in the second brightness control mode in response to the input dimming code value being greater than or equal to the second reference dimming code value.

[0025] According to an embodiment, the first reference dimming code value may be one of a plurality of dimming code values ​​included in the first dimming range, and the second reference dimming code value may be one of a plurality of dimming code values ​​included in the second dimming range.

[0026] According to an embodiment, the display panel may include pixels operating in response to a data signal and a light emitting signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The above and other objects and features of the present disclosure will become apparent by describing in detail embodiments of the present disclosure with reference to the attached drawings.

[0028] Figure 1 is a block diagram of a display device according to an embodiment of the present disclosure.

[0029] Figure 2 is a circuit diagram of a pixel according to an embodiment of the present disclosure.

[0030] Figure 3 The present invention is shown in the embodiment of the present invention. Figure 2 A timing diagram of the operation of a pixel is shown in FIG.

[0031] Figure 4 is a block diagram of a drive controller according to an embodiment of the present disclosure.

[0032] Figure 5 is a view showing an operation mode of a driving controller based on an input dimming code value according to an embodiment of the present disclosure.

[0033] Fig. 6A , Figure 6B and Figure 6C is a view illustrating a light emitting signal in a first brightness control mode according to an embodiment of the present disclosure.

[0034] Figure 7 is a view showing a relationship between input data and an output data signal based on an input dimming code value according to an embodiment of the present disclosure.

[0035] Figure 8 is a diagram illustrating a relationship between input data and output data signals according to dimming code values ​​according to an embodiment of the present disclosure.

[0036] Fig. 9 is a view showing an operation mode of a drive controller according to an embodiment of the present disclosure.

[0037] Fig. 10A and Fig. 10B is a view showing a chromaticity difference according to brightness according to an embodiment of the present disclosure.

[0038] Fig.11 is a flowchart illustrating a method for driving a display device according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0039] In this specification, the expression that a first component (or region, layer, portion, part, etc.) is "on", "connected to" or "coupled to" a second component means that the first component is directly on, directly connected to or directly coupled to the second component, or means that a third component is interposed therebetween.

[0040] The same reference numerals will be assigned to the same components. In addition, in the drawings, the thickness, proportion and size of the components may be exaggerated to effectively describe the technical features. The term "and / or" includes any and all combinations of one or more of the related components.

[0041] Although the terms first, second, etc. may be used herein to describe various components, these components should not be limited by these terms. These terms are used to distinguish one component from another component. For example, without departing from the technical scope of the present disclosure, the first component discussed below may be referred to as the second component. Similarly, the second component may be referred to as the first component. Unless the context clearly indicates otherwise, the singular form is intended to include the plural form.

[0042] In addition, the terms "below", "at the lower portion", "above", and "upper portion" are used to describe the relationship between components shown in the drawings. These terms are relative and are described with reference to the directions indicated in the drawings.

[0043] It will also be understood that the terms “comprises,” “including,” “contains,” “including,” or “having” specify the presence of stated features, quantities, steps, operations, components, parts, or combinations thereof, but do not preclude the presence or addition of one or more other features, quantities, steps, operations, components, parts, and / or combinations thereof.

[0044] Unless otherwise defined, all terms (including technical terms and scientific terms) used in the specification have the same meaning as commonly understood by those skilled in the art to which the present disclosure belongs. In addition, terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning consistent with the meaning in the context of the relevant technology, and should not be interpreted in an idealized or overly formalized meaning unless explicitly defined herein.

[0045] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0046] Figure 1 is a block diagram showing a display device DD according to an embodiment of the present disclosure.

[0047] refer to Figure 1 , the display device DD includes a display panel DP, a driving controller 100 , a data driving circuit 200 , a voltage generator 300 , and a gamma voltage generator 400 .

[0048] The driving controller 100 receives an input image signal RGB and a control signal CTRL. The driving controller 100 converts the input image signal RGB into an output data signal DS and outputs the output data signal DS. The driving controller 100 may also output various signals such as a scan control signal SCS, a data control signal DCS, an emission control signal ECS, and a voltage code value V_code.

[0049] The gamma voltage generator 400 may generate a plurality of gamma voltages V_GMMA according to the voltage code value V_code provided from the driving controller 100. The gamma voltage generator 400 may output the plurality of gamma voltages V_GMMA to the data driving circuit 200.

[0050] The data driving circuit 200 receives a data control signal DCS and an output data signal DS from the driving controller 100, and receives a plurality of gamma voltages V_GMMA from the gamma voltage generator 400. The data driving circuit 200 converts the output data signal DS into a data signal based on the plurality of gamma voltages V_GMMA, and then outputs the data signal to a plurality of data lines DL1, DL2, . . . and DLm to be described later.

[0051] The voltage generator 300 generates voltages for operating the display panel DP. According to an embodiment, the voltage generator 300 generates a first driving voltage ELVDD, a second driving voltage ELVSS, a first initialization voltage VINT1, and a second initialization voltage VINT2.

[0052] The display panel DP includes scan lines GIL1 to GILn, GCL1 to GCLn and GWL1 to GWLn+1, emission lines EML1 to EMLn, data lines DL1 to DLm and pixels PX. The display panel DP may further include a scan drive circuit SDC and an emission drive circuit EDC. According to an embodiment, the scan drive circuit SDC may be disposed at a first side of the display panel DP. The scan lines GIL1 to GILn, GCL1 to GCLn and GWL1 to GWLn+1 extend from the scan drive circuit SDC in a first direction DR1.

[0053] The light emitting driving circuit EDC is disposed at the second side of the display panel DP. The light emitting lines EML1 to EMLn extend from the light emitting driving circuit EDC in a direction opposite to the first direction DR1.

[0054] The scan lines GIL1 to GILn, GCL1 to GCLn and GWL1 to GWLn+1 and the emission lines EML1 to EMLn are arranged to be spaced apart from each other in the second direction DR2. The data lines DL1 to DLm extend from the data driving circuit 200 in a direction opposite to the second direction DR2 and may be arranged to be spaced apart from each other in the first direction DR1.

[0055] according to Figure 1 In the embodiment shown in , the scanning driving circuit SDC and the light emitting driving circuit EDC are arranged to face each other, and the pixel PX is inserted between the scanning driving circuit SDC and the light emitting driving circuit EDC. However, the present disclosure is not limited to this. For example, the scanning driving circuit SDC and the light emitting driving circuit EDC may be arranged adjacent to each other in the non-display area NDA of the display panel DP. According to an embodiment, the scanning driving circuit SDC and the light emitting driving circuit EDC may be implemented as one circuit in one body. For example, the scanning driving circuit SDC and the light emitting driving circuit EDC may be integrated into a single chip or a single package.

[0056] The plurality of pixels PX are electrically connected to the scan lines GIL1 to GILn, GCL1 to GCLn and GWL1 to GWLn+1, the emission lines EML1 to EMLn and the data lines DL1 to DLm. Each of the plurality of pixels PX may be electrically connected to four scan lines and one emission line. Figure 1 As shown in , each of the pixels PX in the first row can be connected to the scan lines GIL1, GCL1, GWL1 and GWL2 and the emission line EML1. Each of the pixels PX in the i-th row can be connected to the scan lines GILi, GCLi, GWLi and GWLi+1 and the emission line EMLi. Each of the pixels PX in the N-th row can be connected to the scan lines GILn, GCLn, GWLn and GWLn+1 and the emission line EMLn.

[0057] Each of the plurality of pixels PX may include a light emitting element ED (see Figure 2 ) and a pixel circuit PXC for controlling the light emitting operation of the light emitting element ED (see Figure 2 ). The pixel circuit PXC may include at least one transistor and at least one capacitor. The scan driving circuit SDC and the light emitting driving circuit EDC may include transistors formed by the same process as that for the pixel circuit PXC.

[0058] Each of the plurality of pixels PX receives a first driving voltage ELVDD, a second driving voltage ELVSS, a first initialization voltage VINT1 , and a second initialization voltage VINT2 from the voltage generator 300 .

[0059] The scan driving circuit SDC receives a scan control signal SCS from the driving controller 100. The scan driving circuit SDC may output scan signals to the scan lines GIL1 to GILn, GCL1 to GCLn, and GWL1 to GWLn+1 in response to the scan control signal SCS.

[0060] The light emitting driving circuit EDC receives a light emitting control signal ECS from the driving controller 100. The light emitting driving circuit EDC may output a light emitting control signal to the light emitting lines EML1 to EMLn in response to the light emitting control signal ECS. According to an embodiment, the light emitting driving circuit EDC may adjust a pulse width of a light emitting signal provided to the light emitting lines EML1 to EMLn in response to the light emitting control signal ECS.

[0061] Figure 2 is a circuit diagram of a pixel PX according to an embodiment of the present disclosure.

[0062] Figure 2 Shows the connection to Figure 1 , among the data lines DL1 to DLm shown in FIG. Figure 1The i-th scan line GILi, GCLi and GWLi and the i+1-th scan line GWLi+1 among the scan lines GIL1 to GILn, GCL1 to GCLn and GWL1 to GWLn+1 shown in FIG. Figure 1 Pixel PX of the i-th emission line EMLi among the emission lines EML1 to EMLn shown in FIG.

[0063] Figure 1 Each of the pixels PX shown in FIG. 1 may have Figure 2 The pixel PX shown in FIG.

[0064] refer to Figure 2 According to an embodiment, the pixel PX includes a pixel circuit PXC and at least one light emitting element ED. According to an embodiment, the light emitting element ED may be a light emitting diode. According to an embodiment, although the above description is made in the case where one pixel PX includes one light emitting element ED, the present disclosure is not particularly limited thereto. The pixel circuit PXC includes a first transistor T1, a second transistor T2, a third transistor T3, a fourth transistor T4, a fifth transistor T5, a sixth transistor T6, a seventh transistor T7, and a capacitor Cst.

[0065] According to an embodiment, the third transistor T3 and the fourth transistor T4 among the first transistor T1 to the seventh transistor T7 are N-type transistors including an oxide semiconductor used as a semiconductor layer. Each of the first transistor T1, the second transistor T2, the fifth transistor T5, the sixth transistor T6, and the seventh transistor T7 is a P-type transistor including a low-temperature polycrystalline silicon (LTPS) semiconductor layer. However, the present disclosure is not limited thereto, and all of the first transistor T1 to the seventh transistor T7 may be P-type transistors or N-type transistors. According to an embodiment, at least one of the first transistor T1 to the seventh transistor T7 may be an N-type transistor, and the remaining transistors may be P-type transistors. In addition, the circuit configuration of the pixel PX according to an embodiment of the present disclosure is not limited to Figure 2 The configuration shown in . Figure 2 The pixel circuit PXC shown in FIG. 1 is provided for illustrative purposes only. For example, the configuration of the pixel circuit PXC may be modified.

[0066] The scan lines GILi, GCLi, GWLi, and GWLi+1 may transmit scan signals GIi, GCi, GWi, and GWi+1, respectively, and the emission line EMLi may transmit an emission signal EMi. The data line DLj transmits a data signal Dj. The data signal Dj may have a signal similar to that input to the display device DD (see Figure 1) The first driving voltage line VL1, the second driving voltage line VL2, the third driving voltage line VL3 and the fourth driving voltage line VL4 can transmit the first driving voltage ELVDD, the second driving voltage ELVSS, the first initialization voltage VINT1 and the second initialization voltage VINT2 respectively.

[0067] The first transistor T1 includes a first electrode connected to the first driving voltage line VL1 through the fifth transistor T5, a second electrode electrically connected to the anode of the light emitting element ED through the sixth transistor T6, and a gate electrode connected to the first terminal of the capacitor Cst. The first transistor T1 can receive the data signal Dj received through the data line DLj in response to the switching operation of the second transistor T2, and can apply the driving current Id to the light emitting element ED.

[0068] The second transistor T2 includes a first electrode connected to the data line DLj, a second electrode connected to the first electrode of the first transistor T1, and a gate electrode connected to the scan line GWLi. The second transistor T2 may be turned on in response to a scan signal GWi received through the scan line GWLi, and may transmit a data signal Dj received through the data line DLj to the first electrode of the first transistor T1.

[0069] The third transistor T3 includes a first electrode connected to the gate electrode of the first transistor T1, a second electrode connected to the second electrode of the first transistor T1, and a gate electrode connected to the scan line GCLi. The third transistor T3 can be turned on in response to a scan signal GCi received through the scan line GCLi, and connects the gate electrode of the first transistor T1 to the second electrode, so that the first transistor T1 is diode-connected.

[0070] The fourth transistor T4 includes a first electrode connected to the gate electrode of the first transistor T1, a second electrode connected to the third driving voltage line VL3 for transmitting the first initialization voltage VINT1, and a gate electrode connected to the scan line GILi. The fourth transistor T4 can be turned on in response to the scan signal GIi received through the scan line GILi to perform an initialization operation for transmitting the first initialization voltage VINT1 to the gate electrode of the first transistor T1 to initialize the voltage of the gate electrode of the first transistor T1.

[0071] The fifth transistor T5 may include a first electrode connected to the first driving voltage line VL1 , a second electrode connected to the first electrode of the first transistor T1 , and a gate electrode connected to the light emitting line EMLi.

[0072] The sixth transistor T6 may include a first electrode connected to the second electrode of the first transistor T1, a second electrode connected to the anode of the light emitting element ED, and a gate electrode connected to the light emitting line EMLi.

[0073] The fifth transistor T5 and the sixth transistor T6 may be simultaneously turned on in response to the light emitting signal EMi received through the light emitting line EMLi. Therefore, the first driving voltage ELVDD may be compensated by the first transistor T1 connected as a diode and transmitted to the light emitting element ED.

[0074] The seventh transistor T7 includes a first electrode connected to the second electrode of the sixth transistor T6, a second electrode connected to the fourth driving voltage line VL4, and a gate electrode connected to the scanning line GWLi+1. The seventh transistor T7 is turned on in response to the scanning signal GWi+1 received through the scanning line GWLi+1, and bypasses the current of the anode of the light emitting element ED to the fourth driving voltage line VL4.

[0075] As described above, one terminal of the capacitor Cst is connected to the gate electrode of the first transistor T1, and the other terminal of the capacitor Cst is connected to the first driving voltage line VL1. The cathode of the light emitting element ED may be connected to the second driving voltage line VL2 transmitting the second driving voltage ELVSS. According to an embodiment, the structure of the pixel PX is not limited to Figure 2 For example, the number of transistors included in one pixel PX, the number of capacitors included in the pixel PX, and the connection relationship between the transistors and the capacitors may be variously modified.

[0076] Figure 3 The present invention is shown in the embodiment of the present invention. Figure 2 0 is a timing diagram of the operation of the pixel PX shown in FIG.

[0077] refer to Figure 2 and Figure 3 When the scan signal GIi having a high level is applied through the scan line GILi during the initialization period of one frame F1, the fourth transistor T4 is turned on. The first initialization voltage VINT1 is transmitted to the gate electrode of the first transistor T1 through the turned-on fourth transistor T4, and the gate electrode of the first transistor T1 is initialized by the first initialization voltage VINT1.

[0078] Next, when the scan signal GCi having a high level is applied through the scan line GCLi during the compensation period of one frame F1, the third transistor T3 is turned on. The compensation period may be in a non-overlapping state with the initialization period.

[0079] The first transistor T1 is diode-connected and forward-biased by the third transistor T3 turned on during the compensation period. In addition, the compensation period may overlap with a data writing period in which the scan signal GWi is activated at a low level.

[0080] During the data writing period, the second transistor T2 is turned on by the scanning signal GWi having a low level. In this case, a compensation voltage obtained by lowering the voltage of the data signal Dj provided via the data line DLj by the threshold voltage of the first transistor T1 is applied to the gate electrode of the first transistor T1. In other words, the potential of the gate electrode of the first transistor T1 may be the compensation voltage.

[0081] When the first driving voltage ELVDD and the compensation voltage are respectively applied to opposite terminals of the capacitor Cst, charges corresponding to a voltage difference between the opposite terminals may be stored in the capacitor Cst.

[0082] Meanwhile, the seventh transistor T7 is turned on by receiving the second write scan signal GWi+1 having a low level through the scan line GWLi+1. When the seventh transistor T7 is turned on, the anode of the light emitting element ED may be initialized by the second initialization voltage VINT2.

[0083] Next, the light emitting signal EMi provided from the light emitting line EMLi changes from a high level to a low level. The fifth transistor T5 and the sixth transistor T6 are turned on by the light emitting signal EMi having a low level. Then, the driving current Id is generated due to the voltage difference between the gate voltage of the gate electrode of the first transistor T1 and the first driving voltage ELVDD, and is applied to the light emitting element ED through the sixth transistor T6, so that the driving current Id flows through the light emitting element ED.

[0084] The period in which the light emitting signal EMi is maintained at a high level is the period in which the light emitting element ED is maintained in a non-emission state, and thus the period in which the light emitting signal EMi is maintained at a high level can be referred to as a non-emission period NEP. In addition, the period in which the light emitting signal EMi is maintained at a low level is the period in which the light emitting element ED is maintained in an emission state, and thus the period in which the light emitting signal EMi is maintained at a low level can be referred to as an emission period EP.

[0085] Figure 4 is a block diagram illustrating a driving controller 100 according to an embodiment of the present disclosure.

[0086] refer to Figure 4, the driving controller 100 may include a controller 110 and a data converter 120. The controller 110 receives an input image signal RGB and a control signal CTRL. The controller 110 generates input data I_data by transforming (ie, converting) the data format of the input image signal RGB so that the input image signal RGB is suitable for the display panel DP (see Figure 1 ). In an embodiment, the input image signal RGB may be converted into grayscale. The generated input data I_data is provided to the data converter 120. According to an embodiment, the input image signal RGB may include a red image signal, a green image signal, and a blue image signal.

[0087] The controller 110 generates a scan control signal SCS, a data control signal DCS, and a light emitting control signal ECS in response to the control signal CTRL. The scan control signal SCS, the data control signal DCS, and the light emitting control signal ECS can be provided to the scan driving circuit SDC, the data driving circuit 200, and the light emitting driving circuit EDC, respectively. The controller 110 can also output a voltage code value V_code based on the output data signal DS.

[0088] The controller 110 may provide a preset input dimming code value I_DBV to the data converter 120. The input dimming code value I_DBV may be a value set so that the display device DD displays an image corresponding to a target brightness level. According to an embodiment, the input dimming code value I_DBV may be determined based on dimming information input by a user.

[0089] The input dimming code value I_DBV may be a value selected from a plurality of dimming values. According to an embodiment of the present disclosure, the input dimming code value I_DBV may be a digital value. For example, the input dimming code value I_DBV may be an 8-bit signal.

[0090] The data converter 120 can output the output data signal DS to the data driving circuit 200 by correcting (ie, modifying) the input data I_data based on the input dimming code value I_DBV. Figure 7 The modification of the input data I_data based on the input dimming code value I_DBV is described. According to an embodiment of the present disclosure, the output data signal DS may include red output data, green output data, and blue output data.

[0091] The gamma voltage generator 400 may generate a plurality of gamma voltages V_GMMA according to the voltage code value V_code provided from the driving controller 100. The gamma voltage generator 400 may output the plurality of gamma voltages V_GMMA to the data driving circuit 200.

[0092] The gamma voltage generator 400 may determine the voltage levels of the first gamma reference voltage (or bottom reference voltage) and the second gamma reference voltage (or top reference voltage) according to the voltage code value V_code. The voltage code value V_code may include a bottom voltage code value for determining the voltage level of the first gamma reference voltage and a top voltage code value for determining the voltage level of the second gamma reference voltage. According to an embodiment of the present disclosure, the voltage code value V_code may be a digital value.

[0093] The voltage level of each of the plurality of gamma voltages V_GMMA may be determined by using the first gamma reference voltage and the second gamma reference voltage. For example, each of the plurality of gamma voltages V_GMMA may be equal to or higher than the first gamma reference voltage and equal to or lower than the second gamma reference voltage.

[0094] The data driving circuit 200 may convert the output data signal DS into data signals D1 to Dm based on the plurality of gamma voltages V_GMMA, and may apply the data signals D1 to Dm to the display panel DP (see Figure 1 ) of the data lines DL1 to DLm (see Figure 1 ).

[0095] Figure 5 is a view showing an operation mode of the driving controller 100 based on an input dimming code value I_DBV.

[0096] exist Figure 5 In the graph shown in , the horizontal axis is the dimming code value DBV, and the vertical axis is the output data signal DS. According to an embodiment, the output data signal DS may be a 14-bit digital value.

[0097] refer to Figure 4 and Figure 5 , the controller 110 of the driving controller 100 may compare the input dimming code value I_DBV with the reference dimming code value DBV_TH, and may determine the operation mode based on the comparison result.

[0098] When the input dimming code value I_DBV is less than the reference dimming code value DBV_TH, the controller 110 may determine the operation mode to be the first brightness control mode. In the first brightness control mode, the controller 110 may adjust Figure 3 In other words, the controller 110 generates the light emitting control signal ECS for adjusting the pulse width of the non-emission period NEP of the light emitting signal EMi.

[0099] When the input dimming code value I_DBV is greater than the reference dimming code value DBV_TH, the controller 110 may determine the operation mode as the second brightness control mode. In the second brightness control mode, the controller 110 provides the input dimming code value I_DBV to the data converter 120. In the second brightness control mode, the data converter 120 performs a dimming operation on the input data I_data and outputs an output data signal DS.

[0100] The controller 110 may compare the highest dimming grayscale value (or referred to as dimming grayscale value D_scale) of the output data signal DS after the dimming operation with the highest grayscale value (hereinafter referred to as the highest reference grayscale value GC_max) of the output data signal DS before the dimming operation to update the voltage code value V_code (e.g., the bottom voltage code value) to a new value. The highest dimming grayscale value D_scale may be defined as the highest grayscale value of the output data signal DS that may be presented based on the input dimming code value I_DBV. The highest reference grayscale value GC_max may be preset as the highest dimming grayscale value that may be presented by the output data signal DS before the dimming operation (or determined based on the highest dimming code value among a plurality of dimming code values).

[0101] The controller 110 determines whether to update the voltage code value V_code by determining whether the difference ΔD between the highest dimming gray value D_scale and the highest reference gray value GC_max is greater than a preset reference difference. In detail, when the difference ΔD between the highest dimming gray value D_scale and the highest reference gray value GC_max is greater than the reference difference, the controller 110 updates the voltage code value V_code, and when the difference ΔD between the highest dimming gray value D_scale and the highest reference gray value GC_max is less than or equal to the reference difference, the controller 110 maintains the voltage code value V_code. The voltage code value V_code before the update may be referred to as a first voltage code value, and the voltage code value V_code after the update may be referred to as a second voltage code value.

[0102] According to an embodiment, the difference ΔD may indicate the number of bits. For example, the difference ΔD may be 1 bit. When the difference ΔD between the highest dimming grayscale value D_scale and the highest reference grayscale value GC_max is greater than 1 bit, the controller 110 may update the first voltage code value to the second voltage code value. Thereafter, the updated second voltage code value is provided to the gamma voltage generator 400, and the gamma voltage generator 400 adjusts the voltage level of the first gamma reference voltage (i.e., the bottom reference voltage) based on the second voltage code value. For example, assuming that when the first voltage code value is provided, the first gamma reference voltage has a voltage level of approximately 2.652V, when the second voltage code value is provided, the updated first gamma reference voltage may have a voltage level of approximately 3.409V.

[0103] The gamma voltage generator 400 updates a plurality of gamma voltages V_GMMA based on the updated first gamma reference voltage. Therefore, even if the gray level of the output data signal DS is lost due to the input dimming code value I_DBV, the data driving circuit 200 generates data signals D1 to Dm based on the plurality of updated gamma voltages V_GMMA, so that no gray level loss greater than or equal to a preset reference value occurs in the data signals D1 to Dm provided to the display panel DP.

[0104] Fig. 6A 、 Figure 6B and Figure 6C is a view showing the light emission signal EMi in the first brightness control mode.

[0105] Reference Figure 4 、 Fig. 6A 、 Figure 6B and Figure 6C , in the first brightness control mode, the controller 110 can adjust the pulse width of the light emission signal EMi.

[0106] In one frame F1, the times of the non-light emission periods NEP1, NEP2, and NEP3 of the light emission signal EMi can have a relationship of NEP1 > NEP2 > NEP3.

[0107] In one frame F1, the times of the light emission periods EP1, EP2, and EP3 of the light emission signal EMi can have a relationship of EP1 < EP2 < EP3.

[0108] As the times of the non-light emission periods NEP1, NEP2, and NEP3 increase, in other words, as the times of the light emission periods EP1, EP2, and EP3 decrease, the time for light emission of the light emitting element ED (see Figure 2 ) decreases. Therefore, the brightness of the pixel PX (see Figure 2 ) can be reduced.

[0109] Conversely, as the times of the non-light emission periods NEP1, NEP2, and NEP3 decrease, in other words, as the times of the light emission periods EP1, EP2, and EP3 increase, the time for light emission of the light emitting element ED (see Figure 2 ) increases. Therefore, the brightness of the pixel PX (see Figure 2 ) can be increased.

[0110] For example, the input dimming code value I_DBV can be preset according to the dimming information input by the user. When the input dimming code value I_DBV is less than the reference dimming code value DBV_TH (see Figure 5 ), the driving controller 100 operates in the first brightness control mode.

[0111] In the first brightness control mode, the controller 110 can control the brightness of the image by inputting the dimming code value I_DBV as follows: Fig. 6A , Figure 6B and Figure 6C As shown in FIG. 8 , the pulse width of the emission signal EMi is adjusted to adjust the brightness of the pixel PX.

[0112] However, in the first brightness control mode, the brightness provided to the display panel DP (see Figure 1 ) of the entire pixel PX drive current Id (see Figure 2 ) may degrade the light emitting element ED (see Figure 2 )'s current-to-light characteristics (e.g., chromaticity difference).

[0113] Figure 7 is a view showing a relationship between input data I_data and an output data signal DS according to an input dimming code value.

[0114] refer to Figure 4 and Figure 7 , when the input dimming code value I_DBV is DBVa, DBVb, DBVc, DBVd, and DBVe, the output data signal DS may vary according to the input data I_data. Figure 7 In the embodiment, the input dimming code value I_DBV has the relationship of DBVa>DBVb>DBVc>DBVd>DBVe. In other words, as the input dimming code value I_DBV decreases, the digital value of the output data signal DS corresponding to the input data I_data may decrease.

[0115] Furthermore, regardless of the input dimming code value I_DBV, the gray level may be lost, and thus the gray level (ie, digital value) decreases at a higher gray level (eg, a gray level of 251) of the input data I_data.

[0116] Figure 8 is a diagram showing the relationship between input data I_data and output data signal DS according to dimming code values.

[0117] Figure 8 It is shown that the first line L1 represents the relationship between the input data I_data and the output data signal DS before dimming. The second line L2 represents the relationship between the input data I_data and the output data signal DS after dimming according to the input dimming code value I_DBV.

[0118] refer to Figure 4 and Figure 8, the controller 110 may compare the dimming grayscale value D_scale of the output data signal DS after dimming with the highest reference grayscale value GC_max of the output data signal DS before dimming to update the voltage code value V_code (eg, the bottom voltage code value).

[0119] The controller 110 determines whether to update the voltage code value V_code by determining whether the difference ΔD between the highest dimming gray value D_scale and the highest reference gray value GC_max is greater than a preset reference difference. In detail, when the difference ΔD between the highest dimming gray value D_scale and the highest reference gray value GC_max is greater than the reference difference, the controller 110 may update the voltage code value V_code. In addition, when the difference ΔD between the highest dimming gray value D_scale and the highest reference gray value GC_max is less than or equal to the reference difference, the controller 110 maintains the voltage code value V_code. In this case, the voltage code value V_code before the update may be referred to as a first voltage code value, and the voltage code value V_code after the update may be referred to as a second voltage code value.

[0120] According to an embodiment, the difference ΔD may indicate the number of bits. For example, the difference ΔD may be one bit. When the difference ΔD between the highest dimming grayscale value D_scale and the highest reference grayscale value GC_max is greater than one bit, the controller 110 may update the first voltage code value to a second voltage code value. Thereafter, the updated second voltage code value is provided to the gamma voltage generator 400, and the gamma voltage generator 400 adjusts the voltage level of the first gamma reference voltage (in other words, the bottom reference voltage) based on the second voltage code value.

[0121] The gamma voltage generator 400 updates the plurality of gamma voltages V_GMMA based on the updated first gamma reference voltage. Therefore, even if the gray level of the output data signal DS is lost due to the input dimming code value I_DBV, the data driving circuit 200 can generate the data signals D1 to Dm based on the plurality of updated gamma voltages V_GMMA. Therefore, even if the gray level (in other words, digital value) of the output data signal DS is reduced at a high gray level (e.g., a gray level of 253) of the input data I_data, the gray level can be compensated by the plurality of gamma voltages V_GMMA.

[0122] Fig. 9 2 is a view showing an operation mode of the driving controller 100 according to an embodiment of the present disclosure.

[0123] exist Fig. 9 In the graph shown in , the horizontal axis is the dimming code value DBV, and the vertical axis is the output data signal DS. According to an embodiment, the output data signal DS may be a 14-bit digital value.

[0124] refer to Figure 4 and Fig. 9 , the controller 110 of the driving controller 100 determines whether the input dimming code value I_DBV is included in the first dimming section DMM1 (i.e., the first dimming range) or the second dimming section DMM2 (i.e., the second dimming range). For example, the controller 110 may determine whether the input dimming code value I_DBV corresponds to a value in one of the first dimming section DMM1 and the second dimming section DMM2.

[0125] When the input dimming code value I_DBV is a value within a range from “0” to the first maximum code value DBV_NM, the input dimming code value I_DBV may be included in the first dimming zone DMM1. For example, the first maximum code value DBV_NM may be a normal maximum dimming code value, ie, “2047”.

[0126] When the input dimming code value I_DBV is included in the first dimming zone DMM1, the controller 110 may compare the input dimming code value I_DBV with the first reference dimming code value DBV_TH1 and may determine the operation mode based on the comparison result. The first reference dimming code value DBV_TH1 may be one of a plurality of dimming code values ​​included in the first dimming zone DMM1.

[0127] When the input dimming code value I_DBV is less than the first reference dimming code value DBV_TH1, the controller 110 may determine the operation mode to be the first brightness control mode. In the first brightness control mode, the controller 110 may adjust the brightness as follows: Figure 3 In other words, the controller 110 generates the light emitting control signal ECS for adjusting the pulse width of the non-emission period NEP of the light emitting signal EMi.

[0128] When the input dimming code value I_DBV is greater than the first reference dimming code value DBV_TH1, the controller 110 may determine the operation mode as the second brightness control mode. In the second brightness control mode, the controller 110 provides the input dimming code value I_DBV to the data converter 120. In the second brightness control mode, the data converter 120 performs a dimming operation on the input data I_data and outputs an output data signal DS.

[0129] The controller 110 can adjust the dimming grayscale value D_scale (see Figure 5 ) and the highest reference grayscale value GC_max of the output data signal DS before dimming (see Figure 5 ) is compared to update the voltage code value V_code.

[0130] When the input dimming code value I_DBV is a value within the range from the first maximum code value DBV_NM to the second maximum code value DBV_HM, the input dimming code value I_DBV may be included in the second dimming zone DMM2. For example, the second maximum code value DBV_HM may be a higher maximum dimming code value, ie, "4094".

[0131] When the input dimming code value I_DBV is included in the second dimming zone DMM2, the controller 110 may compare the input dimming code value I_DBV with the second reference dimming code value DBV_TH2 and may determine the operation mode based on the comparison result. The second reference dimming code value DBV_TH2 may be one of a plurality of dimming code values ​​included in the second dimming zone DMM2.

[0132] When the input dimming code value I_DBV is less than the second reference dimming code value DBV_TH2, the controller 110 may determine the operation mode to be the first brightness control mode. In the first brightness control mode, the controller 110 may adjust Figure 3 In other words, the controller 110 generates the light emitting control signal ECS for adjusting the pulse width of the non-emission period NEP of the light emitting signal EMi.

[0133] When the input dimming code value I_DBV is greater than the second reference dimming code value DBV_TH2, the controller 110 may determine the operation mode as the second brightness control mode. In the second brightness control mode, the controller 110 provides the input dimming code value I_DBV to the data converter 120. In the second brightness control mode, the data converter 120 performs a dimming operation on the input data I_data and outputs an output data signal DS.

[0134] The controller 110 can adjust the dimming grayscale value D_scale (see Figure 5 ) and the highest reference grayscale value GC_max of the output data signal DS before dimming (see Figure 5 ) is compared to update the voltage code value V_code.

[0135] In the second brightness control mode, the pulse width of the light emitting signal supplied to the light emitting lines EML1 to EMLn may be maintained at a preset value.

[0136] The drive controller 100 can be Fig. 9 . For example, as the change in the pulse width of the light emitting signal applied to the light emitting lines EML1 to EMLn is minimized, the light emitting element ED (see Figure 2)'s current can minimize the degradation of optical characteristics (e.g., chromaticity difference).

[0137] Despite Fig. 9 , only two dimming sections as the first dimming section DMM1 and the second dimming section DMM2 are shown, but the present disclosure is not limited thereto. The dimming section may be a plurality of dimming sections of at least two dimming sections. For example, when three dimming sections are provided, the number of reference dimming code values ​​may be "3". In other words, the controller 110 of the driving controller 100 may compare the input dimming code value I_DBV with the reference dimming code value corresponding to each of the dimming sections, and determine the operation mode according to the comparison result.

[0138] Fig. 10A and Fig. 10B is a view showing chromaticity difference according to brightness.

[0139] exist Fig. 10A and Fig. 10B In the figure, the horizontal axis represents the image displayed on the display device DD (see Figure 1 ) on the vertical axis, and the vertical axis represents the chromaticity difference (ΔUV).

[0140] Fig. 10A is a view showing a chromaticity difference according to brightness when the driving controller 100 uses only one reference dimming code value.

[0141] Fig. 10B is shown when the drive controller 100 is used as Fig. 9 1 is a view of the chromaticity difference according to brightness when the first reference dimming code value DBV_TH1 and the second reference dimming code value DBV_TH2 are shown in FIG.

[0142] According to an embodiment, the chromaticity difference ΔUV of the display device DD is preferably 0.005 or less.

[0143] When the general Fig. 10A and Fig. 10B When making a comparison, it can be appreciated that when the driving controller 100 adopts the first reference dimming code value DBV_TH1 and the second reference dimming code value DBV_TH2 as reference dimming code values, the chromaticity difference according to brightness can be minimized.

[0144] Fig.11 is a flowchart illustrating a method for driving a display device according to an embodiment of the present disclosure.

[0145] refer to Figure 1 , Figure 4 , Fig. 9 and Fig.11, the driving controller 100 of the display device DD may compensate the input data I_data based on the input dimming code value I_DBV and output the output data signal DS.

[0146] In detail, the controller 110 of the driving controller 100 determines whether the input dimming code value I_DBV is included in the first dimming section DMM1 (step S100 ).

[0147] When the input dimming code value I_DBV is included in the first dimming zone DMM1, the controller 110 may compare the input dimming code value I_DBV with the first reference dimming code value DBV_TH1 (S110). According to an embodiment, the first reference dimming code value DBV_TH1 may be a dimming code value included in the first dimming zone DMM1.

[0148] When the input dimming code value I_DBV is less than the first reference dimming code value DBV_TH1, the controller 110 may determine the operation mode as the first brightness control mode and prepare for operation in the first brightness control mode (S112). For example, the controller 110 may set the pulse width of the non-emission period NEP of the light emitting signal EMi to correspond to the input dimming code value I_DBV.

[0149] The controller 110 generates the light emitting control signal ECS for adjusting the pulse width of the non-emission period NEP of the light emitting signal EMi (S114).

[0150] In S110, when the input dimming code value I_DBV is equal to or greater than the first reference dimming code value DBV_TH1, the controller 110 may determine the operation mode as the second brightness control mode and prepare for operation in the second brightness control mode (S122). In the second brightness control mode, the controller 110 provides the input dimming code value I_DBV to the data converter 120.

[0151] In the second brightness control mode, the data converter 120 performs a dimming operation on the input data I_data and outputs an output data signal DS ( S124 ).

[0152] The controller 110 may determine the highest reference grayscale value GC_max of the output data signal DS before dimming (see Figure 8 ) and the dimming grayscale value D_scale of the output data signal DS after dimming (see Figure 8 ) between the difference ΔD (see Figure 8 ) is greater than a preset reference difference (S126).

[0153] When the difference ΔD between the highest dimming grayscale value D_scale and the highest reference grayscale value GC_max is greater than the reference difference, the controller 110 may update the voltage code value V_code ( S128 ).

[0154] When the difference ΔD between the highest dimming grayscale value D_scale and the highest reference grayscale value GC_max is less than or equal to the reference difference, the controller 110 may maintain the voltage code value V_code.

[0155] The gamma voltage generator 400 may set a voltage level of a first gamma reference voltage (or a bottom reference voltage) according to a voltage code value V_code, and generate a plurality of gamma voltages V_GMMA ( S130 ).

[0156] The data driving circuit 200 may generate data signals D1 to Dm based on the updated plurality of gamma voltages V_GMMA.

[0157] In S100 , when the input dimming code value I_DBV is not included in the first dimming zone DMM1 , that is, when the input dimming code value I_DBV is included in the second dimming zone DMM2 , the controller 110 may compare the input dimming code value I_DBV with the second reference dimming code value DBV_TH2 ( S120 ).

[0158] When the input dimming code value I_DBV is less than the second reference dimming code value DBV_TH2, the controller 110 may determine the operation mode as the first brightness control mode and prepare for operation in the first brightness control mode (S112). The operation in the first brightness control mode has been described above.

[0159] When the input dimming code value I_DBV is equal to or greater than the second reference dimming code value DBV_TH2, the controller 110 may determine the operation mode as the second brightness control mode and prepare for operation in the second brightness control mode (S122). The operation in the second brightness control mode has been described above.

[0160] According to the present disclosure, the display device may operate in a first brightness mode for adjusting a pulse width of a light emitting control signal and a second brightness mode for changing a gray level of output data according to a dimming code value.

[0161] According to the present disclosure, the display device can minimize the operation duration in the first brightness mode, and thus, can prevent the degradation of display quality due to the change of the pulse width of the light emitting control signal.

[0162] Although the embodiments of the present disclosure have been described for illustrative purposes, it will be understood by those skilled in the art that various modifications and substitutions are possible without departing from the scope and spirit of the present disclosure as disclosed in the appended claims. Therefore, the technical scope of the present disclosure is not limited to the detailed description of this specification, but should be defined by the claims.

Claims

1. Display equipment, including: Display panel; a driving controller configured to modify an input image signal, output an output data signal, and generate a light emitting control signal; a data driving circuit configured to convert the output data signal into a data signal based on a plurality of gamma voltages and apply the data signal to the display panel; as well as a light emitting driving circuit, configured to provide a light emitting signal to the display panel in response to the light emitting control signal, Wherein, the drive controller is configured as: determining whether the input dimming code value is within one of a plurality of dimming ranges including a first dimming range and a second dimming range; In response to determining that the input dimming code value is within the first dimming range, comparing the input dimming code value with a first reference dimming code value, and operating in one of a first brightness control mode and a second brightness control mode according to a result of the comparison between the input dimming code value and the first reference dimming code value; In response to determining that the input dimming code value is within the second dimming range, comparing the input dimming code value with a second reference dimming code value, and operating in one of the first brightness control mode and the second brightness control mode according to a result of the comparison between the input dimming code value and the second reference dimming code value; In the first brightness control mode, outputting the light emitting control signal for adjusting the pulse width of the light emitting signal; and In the second brightness control mode, the output data signal is output by modifying the input image signal based on the input dimming code value.

2. The display device according to claim 1, further comprising: a gamma voltage generator, generating the plurality of gamma voltages in response to a first voltage code value, The driving controller is configured to generate the first voltage code value based on the output data signal. The first voltage code value includes a bottom voltage code value for determining a voltage level of a first gamma reference voltage and a top voltage code value for determining a voltage level of a second gamma reference voltage, and The plurality of gamma voltages are between the first gamma reference voltage and the second gamma reference voltage.

3. The display device according to claim 2, in, The drive controller is configured as follows: In the second brightness control mode, the first voltage code value is updated to a second voltage code value based on a difference between a highest dimming gray value of the output data signal and a preset highest reference gray value.

4. The display device according to claim 3, in, The drive controller is configured as follows: In response to the difference between the highest dimming grayscale value and the preset highest reference grayscale value being greater than a preset reference difference, the first voltage code value is updated to the second voltage code value.

5. The display device according to claim 3, in, The drive controller is configured as follows: The first voltage code value is maintained in response to the difference between the highest dimming grayscale value and the preset highest reference grayscale value being equal to or less than a preset reference difference.

6. The display device according to claim 1, in, The drive controller is configured as follows: In the first brightness control mode, the light emitting control signal is output to generate the light emitting signal having a pulse width corresponding to the input dimming code value.

7. The display device according to claim 1, in, The drive controller is configured as follows: operating in the first brightness control mode in response to the input dimming code value being less than the first reference dimming code value, and and operating in the second brightness control mode in response to the input dimming code value being greater than or equal to the first reference dimming code value.

8. The display device according to claim 1, in, The drive controller is configured as follows: operating in the first brightness control mode in response to the input dimming code value being less than the second reference dimming code value, and and operating in the second brightness control mode in response to the input dimming code value being greater than or equal to the second reference dimming code value.

9. The display device according to claim 1, in, The first reference dimming code value is one of a plurality of dimming code values ​​included in the first dimming range, and The second reference dimming code value is one of a plurality of dimming code values ​​included in the second dimming range.

10. The display device according to claim 1, in, The display panel comprises: The pixel operates in response to the data signal and the light emission signal.

Images