Display device and driving method thereof

Abstract

The present invention provides a display device and a driving method thereof, wherein the display device comprises: a display panel comprising a plurality of pixels; a control unit, which determines a duty cycle corresponding to an initial driving power supply voltage of the display panel, and controls light emission of the plurality of pixels corresponding to the determined duty cycle, and determines different initial driving power supply voltages based on brightness and color coordinates of the plurality of display panels.

Description

Technical Field

[0001] The present invention relates to a display device and a driving method thereof. Background Art

[0002] Generally, a display device includes a plurality of pixels, and each pixel circuit uses a driving power supply voltage to control a light emitting element. The driving power supply voltage may include a high potential driving power supply voltage and a low potential driving power supply voltage, and each of the driving power supply voltages may be set to a level suitable for its purpose.

[0003] The driving power supply voltage is determined according to the characteristics of the pixel and may be different in each display panel. Currently, considering the worst case, the same value is applied to the display panel. This may be inefficient in terms of power consumption. In order to improve this inefficiency in power consumption, a technique for reducing the ratio of the non-luminous period within one frame period may be applied, but the reduction in the ratio of the non-luminous period may increase the momentary afterimage. Summary of the invention

[0004] The present invention is used to provide a display device and a driving method thereof, which can specifically apply the ratio of a non-luminous period to a frame period, namely, a duty ratio (Off Ratio; OR), according to the characteristics of a display panel.

[0005] In addition, the present invention is used to provide a display device and a driving method thereof, which can apply a duty cycle corresponding to an initial driving power supply voltage to a display panel.

[0006] The display device involved in an embodiment of the present invention includes: a display panel including multiple pixels; a control unit, which determines a duty cycle corresponding to an initial driving power supply voltage of the display panel and controls the light emission of the multiple pixels corresponding to the determined duty cycle; different initial driving power supply voltages can be determined based on the brightness and color coordinates of multiple display panels.

[0007] In addition, the control unit may include: a driving power supply voltage determination unit that determines the initial driving power supply voltage based on the brightness and the color coordinates of the display panel; and a duty ratio determination unit that determines the duty ratio corresponding to the initial driving power supply voltage.

[0008] Furthermore, the duty ratio determination unit may increase the duty ratio as the initial driving power supply voltage for the plurality of display panels increases.

[0009] Furthermore, the driving power supply voltage determination unit may determine an offset based on a distribution of the initial driving power supply voltages for the plurality of display panels, and may reflect the determined offset on the initial driving power supply voltage to determine a final driving power supply voltage.

[0010] In addition, the display device may further include: a power supply unit that supplies power corresponding to the final driving power voltage to the display panel.

[0011] In addition, the display device may further include: a light emitting driving unit that generates a light emitting control signal based on the duty ratio and applies the light emitting control signal to the plurality of pixels.

[0012] In addition, the light-emitting driving unit can apply a light-emitting control signal of an off level to the multiple pixels during a non-light-emitting period within a frame determined by the duty cycle, and can apply a light-emitting control signal of an on level to the multiple pixels during a light-emitting period within a frame determined by the duty cycle.

[0013] In addition, the initial driving power supply voltage may be a low potential initial driving power supply voltage.

[0014] In addition, a driving method for a display device involved in an embodiment of the present invention includes: a step of determining an initial driving power supply voltage based on the brightness and color coordinates of a display panel including multiple pixels; a step of determining a duty cycle corresponding to the determined initial driving power supply voltage; and a step of controlling the light emission of the multiple pixels corresponding to the determined duty cycle; different initial driving power supply voltages can be determined based on the brightness and color coordinates of multiple display panels.

[0015] In addition, the step of determining the duty ratio may include the step of increasing the duty ratio as the initial driving power supply voltage for the plurality of display panels increases.

[0016] In addition, the driving method of the display device may further include: a step of determining an offset based on the distribution of the initial driving power supply voltage for the multiple display panels; a step of reflecting the determined offset in the initial driving power supply voltage to determine a final driving power supply voltage; and a step of supplying power corresponding to the final driving power supply voltage to the display panel.

[0017] In addition, the step of controlling light emission for the plurality of pixels may include: the step of generating a light emission control signal based on the duty ratio; and the step of applying the light emission control signal to the plurality of pixels.

[0018] In addition, the step of applying the light-emitting control signal may include: the step of applying the light-emitting control signal of the off-level to the multiple pixels during the non-light-emitting period within a frame determined by the duty cycle; and the step of applying the light-emitting control signal of the on-level to the multiple pixels during the light-emitting period within a frame determined by the duty cycle.

[0019] In addition, a driving method for a display device involved in an embodiment of the present invention may include: a step of determining an initial driving power supply voltage for each of the multiple display panels based on the characteristics of the brightness and color coordinates of each of the multiple display panels; a step of determining a common driving power supply voltage for the multiple display panels based on the distribution of the initial driving power supply voltage; and a step of setting a duty cycle for each of the multiple display panels based on the difference between the initial driving power supply voltage for each of the multiple display panels and the common driving power supply voltage.

[0020] In addition, the common driving power supply voltage may be determined as a lowest value of the initial driving power supply voltages.

[0021] In addition, the duty ratio may be set to be proportional to a difference between the initial driving power supply voltage and the common driving power supply voltage.

[0022] In addition, the different brightness and color coordinates may be determined based on at least one of a sample of a light-emitting element included in each of the plurality of display panels, and a type, specification, and size of the display device.

[0023] In addition, the duty ratio may be set to control the length of a light-emitting period and a non-light-emitting period within one frame for each of the plurality of display panels while the plurality of display panels are driven by applying the common driving power supply voltage.

[0024] In addition, the common driving power supply voltage may be a low potential driving power supply voltage.

[0025] In addition, the step of setting the duty ratio of each of the plurality of display panels may be performed before the initial driving of the display panel.

[0026] (Effects of the Invention)

[0027] The display device and the driving method thereof according to the embodiments of the present invention specifically apply the duty cycle according to the initial driving power supply voltage of the display panel, thereby minimizing the power consumption and improving the instantaneous afterimage effect. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0029] Figure 2 It is shown Figure 1 A diagram of one embodiment of a pixel is illustrated.

[0030] Figure 3 This is a diagram showing an example of a light-emitting period and a non-light-emitting period within one frame period.

[0031] Figure 4 It is shown Figure 1 This is a block diagram showing a specific structure of a control unit.

[0032] Figure 5 and Figure 6 This is a graph for explaining a method for determining a driving power supply voltage according to the present invention.

[0033] Figure 7 is a graph showing the duty ratio according to the embodiment of the present invention.

[0034] Figure 8 1 is a flowchart showing a method for driving a display device according to the present invention. DETAILED DESCRIPTION

[0035] Details of other embodiments are included in the detailed description and accompanying drawings.

[0036] The advantages and features of the present invention and the methods for implementing the same will become clearer with reference to the embodiments described in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various forms. In the following description, when a part is connected to other parts, it includes not only the case of direct connection, but also the case of electrical connection with other components sandwiched therebetween. In addition, in order to accurately illustrate the present invention, parts not related to the present invention are omitted in the accompanying drawings, and similar parts are given the same symbols throughout the specification.

[0037] Figure 1 This is a block diagram showing a display device according to an embodiment of the present invention.

[0038] Reference Figure 1 A display device according to an embodiment of the present invention includes: a display panel 100 including a plurality of pixels PX; a scan driving unit 210; a data driving unit 220; a light emitting driving unit 230; a power supply unit 240; and a control unit 250.

[0039] The control unit 250 may generate a scan drive control signal, a data drive control signal, a light emitting drive control signal, and a power drive control signal based on a signal input from the outside. The scan drive control signal generated by the control unit 250 may be supplied to the scan drive unit 210, the data drive control signal may be supplied to the data drive unit 220, the light emitting drive control signal may be supplied to the light emitting drive unit 230, and the power drive control signal may be supplied to the power supply unit 240.

[0040] The scan drive control signal may include a plurality of clock signals and a scan start signal. The scan start signal may control the output timing of the first scan signal. The clock signal may be used to shift the scan start signal.

[0041] The data driving control signal may include a source start pulse and a clock signal. The source start pulse may be used to control the start point of data sampling, and the clock signal may be used to control the sampling action.

[0042] The light-emitting driving control signal includes a light-emitting start pulse and a clock signal. The light-emitting start pulse controls the first timing of the light-emitting control signal. The clock signal is used to shift the light-emitting start pulse.

[0043] The scan driving unit 210 may output a scan signal corresponding to the scan driving control signal. The scan driving unit 210 may sequentially supply the scan signal to the scan lines S1 to Sn. Here, the scan signal may be set to a gate-on voltage (eg, a high level voltage) to turn on a transistor included in the pixel PX.

[0044] The data driving unit 220 may supply data signals to the data lines D1 to Dm corresponding to the data driving control signal. The data signals supplied to the data lines D1 to Dm may be supplied to the pixels PX supplied with the scanning signals. To this end, the data driving unit 220 may supply data signals to the data lines D1 to Dm so as to be synchronized with the scanning signals.

[0045] The light-emitting driving unit 230 may supply a light-emitting control signal to the light-emitting control lines E1 to En in response to the light-emitting driving control signal. The light-emitting control signal may be used to control the light-emitting time of the pixel PX. For example, a specific pixel PX that has received the light-emitting control signal may be set to a light-emitting state during a period in which the light-emitting control signal is supplied (e.g., during a period in which a light-emitting control signal of an on level is supplied), and may be set to a non-light-emitting state during the remaining period (e.g., during a period in which a light-emitting control signal of an off level is supplied). Hereinafter, the period in which the pixel is set to a light-emitting state according to the light-emitting control signal is referred to as a light-emitting period, and the period in which the pixel is set to a non-light-emitting state is referred to as a non-light-emitting period.

[0046] In various embodiments of the present invention, the ratio of the non-luminous period in one frame period, i.e., the duty ratio (OffRatio; OR) can be determined corresponding to the initial driving power supply voltage of the display panel 100. Here, the duty ratio can be an AID (AMOLED (Active Matrix Organic Light Emitting Diode) Impulsive Driving) duty ratio (AID Off Ratio; AOR). The supply period of the light emitting control signal can be controlled within one frame period according to the determined duty ratio.

[0047] The light-emitting driving unit 230 may supply a light-emitting control signal of an on level during the light-emitting period and output a light-emitting control signal of an off level during the non-light-emitting period, corresponding to the duty ratio defined by the light-emitting driving control signal. Figures 4 to 8The light emission control signal supply method according to the duty ratio of the light emission driving unit 230 according to the present invention will be described in more detail.

[0048] The power supply unit 240 may supply a driving power voltage to each pixel PX of the display panel 100 based on the power driving control signal. For example, the power supply unit 240 may supply a first driving power voltage ELVDD and a second driving power voltage ELVSS to the display panel 100. The first driving power voltage ELVDD may be set to a high potential voltage, and the second driving power voltage ELVSS may be set to a low potential voltage.

[0049] In various embodiments of the present invention, the driving power supply voltage supplied by the power supply unit 240 can be determined according to the initial driving power supply voltage. The initial driving power supply voltage can be determined according to the brightness and color coordinates of the light-emitting element of each pixel PX. The driving power supply voltage can be finally determined by considering the lowest value of the initial driving power supply voltage determined for various display panels 100 and applying a predetermined offset to the initial driving power supply voltage.

[0050] The control unit 250 may include information related to the level of the driving power supply voltage determined as described above in the power drive control signal and transmit it to the power supply unit 240. The power supply unit 240 may generate the driving power supply voltage of the determined level based on the power drive control signal and supply it to the display panel 100. Figure 5 and Figure 6 The method of determining the driving power supply voltage will be described in more detail.

[0051] The display panel 100 may include a plurality of pixels PX connected to data lines D1 to Dm, scan lines S1 to Sn, and light emitting control lines E1 to En. Each pixel PX may receive a data signal from the data lines D1 to Dm when a scan signal is supplied from the scan lines S1 to Sn connected thereto. The pixel PX receiving the data signal may control the amount of current flowing from the first driving power supply voltage ELVDD to the second driving power supply voltage ELVSS via the light emitting element (not shown) in accordance with the data signal. At this time, the light emitting element may generate light of a predetermined brightness in accordance with the amount of current.

[0052] Figure 2 yes Figure 1 A diagram of an embodiment of a pixel is shown, Figure 3 is a diagram showing an example of a light-emitting period and a non-light-emitting period within one frame period. Figure 2 In the figure, for convenience of explanation, a pixel PX connected to an i-th scan line Si, a j-th data line Dj, and an i-th emission control line Ei is shown.

[0053] Reference Figure 2The pixel PX involved in the embodiment of the present invention may include a first transistor T1 to a third transistor T3, a storage capacitor Cst and a light emitting element OLED.

[0054] The first transistor T1 (driving transistor) is connected between the first driving power supply voltage ELVDD and the third transistor T3. The gate electrode of the first transistor T1 is connected to the first node N1. The first transistor T1 can be turned on corresponding to the voltage of the first node N1. As the first transistor T1 is turned on, corresponding to the voltage stored in the energy storage capacitor Cst, the driving current can flow from the first driving power supply voltage ELVDD to the light emitting element OLED via the third transistor T3.

[0055] The second transistor T2 (switching transistor) is connected between the data line Dj and the first node N1. The gate electrode of the second transistor T2 is connected to the scan line Si. The second transistor T2 is turned on when a scan signal of a conduction level is supplied from the scan line Si, and can supply the data signal supplied to the data line Dj to the first node N1.

[0056] The third transistor T3 (light emission control transistor) is connected between the first transistor T1 and the light emitting element OLED. The gate electrode of the third transistor T3 is connected to the light emission control line Ei. The third transistor T3 is turned on when a light emission control signal of a conduction level is supplied from the light emission control line Ei, and can selectively supply the driving current supplied from the first transistor T1 to the light emitting element OLED.

[0057] The storage capacitor Cst is connected between the first node N1 and the first driving power voltage ELVDD. The storage capacitor Cst may store a voltage corresponding to a data signal when the data signal is supplied to the first node N1 via the second transistor T2.

[0058] The first electrode of the light emitting element OLED is connected to the third transistor T3, and the second electrode is connected to the second driving power supply voltage ELVSS. Here, the first electrode may be an anode electrode, and the second electrode may be a cathode electrode. The light emitting element OLED may generate light of a predetermined brightness corresponding to the current amount of the driving current in response to the driving current flowing from the first driving power supply voltage ELVDD to the second driving power supply voltage ELVSS via the first transistor T1 and the third transistor T3.

[0059] exist Figure 2 In the embodiment of the present invention, the transistors T1 to T3 constituting the pixel PX may be constituted by PMOS transistors. However, in various embodiments, at least a portion of the transistors T1 to T3 may be constituted by NMOS transistors, and the pixel circuit may have various modifications accordingly.

[0060] In addition, despite Figure 2An example of a pixel structure is shown, but the pixel PX of the display device according to the embodiment of the present invention is not limited to Figure 2 The pixel structure shown in the figure can have various structures.

[0061] In various embodiments of the present invention, the light emitting control signal supplied to the light emitting control line Ei during one frame period is as follows: Figure 3 As shown, it has an on level during the light-emitting period EP and an off level during the non-light-emitting period NEP. Figure 3 In the embodiment of the present invention, the on-level of the light emitting control signal is set to a low level in order to turn on the third transistor T3 formed by the P MOS transistor. Accordingly, the off-level of the light emitting control signal is set to a high level.

[0062] During the light-emitting period EP, as the third transistor T3 is turned on, a current path is formed from the first driving power supply voltage ELVDD through the light-emitting element OLED to the second driving power supply voltage ELVSS, so that the light-emitting element OLED emits light. During the non-light-emitting period NEP, as the third transistor T3 is turned off, the current path from the first driving power supply voltage ELVDD to the second driving power supply voltage ELVSS is blocked, so that the light-emitting element OLED does not emit light.

[0063] In various embodiments of the present invention, the ratio of the non-luminous period NEP to one frame period, that is, the duty ratio, can be determined according to the initial driving power supply voltage. In particular, the duty ratio can be determined based on the low potential initial driving power supply voltage.

[0064] In this embodiment of the present invention, the low potential initial driving power supply voltage can be determined according to the brightness and color coordinates of the display panel 100. In addition, the final low potential driving power supply voltage can be determined by applying an offset determined by multi-point programming to the low potential initial driving power supply voltage.

[0065] As described above, the method for determining the driving power supply voltage according to the present invention is described in more detail below.

[0066] Figure 4 It is shown Figure 1 The block diagram of the specific structure of the control unit shown in the figure. Figure 5 and Figure 6 is a graph for explaining a method for determining a driving power supply voltage according to the present invention. Figure 7 is a graph showing the duty ratio according to the embodiment of the present invention.

[0067] Reference Figure 4 The control unit 250 of the display device according to the embodiment of the present invention may include a driving power supply voltage determination unit 251 and a duty ratio determination unit 252 .

[0068] The driving power supply voltage determination unit 251 may determine an initial driving power supply voltage (VDD, VSS) based on the brightness and color coordinates of the display panel 100 , and may reflect a predetermined offset to the determined initial driving power supply voltage (VDD, VSS) to determine a final driving power supply voltage (ELVDD, ELVSS).

[0069] Specifically, the driving power supply voltage determination unit 251 may set the initial driving power supply voltage (VDD, VSS) of the display panel 100. Here, the initial driving power supply voltage (VDD, VSS) may include a first initial driving power supply voltage VDD and a second initial driving power supply voltage VSS. The first initial driving power supply voltage VDD may be a high potential initial driving power supply voltage, and the second initial driving power supply voltage VSS may be a low potential initial driving power supply voltage.

[0070] The initial driving power supply voltage (VDD, VSS) can be determined based on the brightness and color coordinates of the display panel 100. The brightness and color coordinates of the display panel 100 can be determined based on the sample of the light-emitting element OLED provided in the display panel 100, the type and specification of the display device, the size of the display panel 100, etc. Figure 5 The brightness and color coordinate curves shown in the figure determine the initial driving power supply voltage (VDD, VSS).

[0071] If the initial driving power supply voltage (VDD, VSS) is determined, the driving power supply voltage determination unit 251 may determine the final driving power supply voltage (ELVDD, ELVSS) by applying a predetermined offset to the initial driving power supply voltage (VDD, VSS).

[0072] For example, the driving power supply voltage determination unit 251 is as follows: Figure 6 As shown in FIG. 1 , the offset of the second initial driving power supply voltage VSS can be determined by considering the lowest value of the second initial driving power supply voltage VSS determined for various display panels 100 . Figure 6 1 shows the distribution of the second initial driving power supply voltage VSS for the display panel 100. The display panels 100 manufactured with the same specifications are produced by the same materials and processes, and thus have the same panel characteristics, and therefore should have the same second initial driving power supply voltage VSS accordingly. However, due to process and design reasons, the display panel 100 may actually have different second initial driving power supply voltages VSS. Such a second initial driving power supply voltage VSS of the display panel 100 is as follows: Figure 6 As shown, it can have a Gaussian distribution.

[0073] Although the second initial driving power voltage VSS may be used as the actual second driving power voltage ELVSS for all display panels 100, the second driving power voltage ELVSS of the display panel 100 may be set to the lowest value (in the range of 1 to 100) of the second initial driving power voltage VSS for the display panel 100 for convenience of mass production. Figure 6 is -2.5V).

[0074] In such an embodiment, the offset may correspond to a difference between the lowest value of the second initial driving power supply voltage VSS for various display panels 100 and the second initial driving power supply voltage VSS determined as described above for the corresponding display panel. Accordingly, the driving power supply voltage determination unit 251 may reflect the determined offset (e.g., subtraction) to the second initial driving power supply voltage VSS to determine the second driving power supply voltage ELVSS.

[0075] The first driving power supply voltage ELVDD may be determined by considering the offset as described above, or may be determined corresponding to the determined second driving power supply voltage ELVSS. For example, the driving power supply voltage determination unit 251 may determine the first driving power supply voltage ELVDD by applying the offset determined for the second initial driving power supply voltage VSS to the first initial driving power supply voltage VDD.

[0076] The driving power supply voltage determination unit 251 may transmit the initial driving power supply voltage (VDD, VSS) determined in the above to the duty ratio determination unit 252. For example, the driving power supply voltage determination unit 251 may transmit the second initial driving power supply voltage VSS to the duty ratio determination unit 252.

[0077] In addition, the driving power voltage determination unit 251 may transmit the determined driving power voltage to the power supply unit 240 , thereby supplying the driving power voltage to the display panel 100 .

[0078] The duty ratio determination unit 252 determines the duty ratio corresponding to the initial driving power supply voltage (VDD, VSS) transmitted from the driving power supply voltage determination unit 251, and controls the light-emitting driving unit 230 corresponding to the determined duty ratio, so that the light-emitting driving unit 230 outputs the light-emitting control signal. For example, the duty ratio determination unit 252 generates the light-emitting driving control signal ECS corresponding to the determined duty ratio, and transmits it to the light-emitting driving unit 230.

[0079] In one embodiment, the duty ratio determination unit 252 may determine the duty ratio corresponding to the second initial driving power supply voltage V SS. For example, the duty ratio determination unit 252 may compare the second initial driving power supply voltage V SS with a preset critical value to determine the critical range to which the second initial driving power supply voltage V SS belongs.

[0080] The duty ratio determination unit 252 may load a preset duty ratio corresponding to the critical range to which the second initial driving power supply voltage VSS belongs. In one embodiment, the duty ratio determination unit 252 may match the corresponding duty ratio according to the critical range for the second initial driving power supply voltage VSS, thereby using a stored look-up table (LUT) or the like to load the preset duty ratio.

[0081] For example, refer to Figure 7 In the case where the second initial driving power supply voltage VSS is less than the first critical value TH1, that is, in the case where the second initial driving power supply voltage VSS belongs to the first critical range THR1, the duty ratio determination unit 252 may determine the duty ratio to be the first value. In addition, in the case where the second initial driving power supply voltage VSS is greater than or equal to the first critical value TH1 and less than the second critical value TH2, that is, in the case where the second initial driving power supply voltage VSS belongs to the second critical range THR2, the duty ratio determination unit 252 may determine the duty ratio to be the second value. In addition, in the case where the second initial driving power supply voltage VSS is greater than or equal to the second critical value TH2, that is, in the case where the second initial driving power supply voltage VSS belongs to the third critical range THR3, the duty ratio determination unit 252 may determine the duty ratio to be the third value.

[0082] In various embodiments, the first value may be less than the second value, and the second value may be less than the third value. For example, the first value may be 2%, the second value may be 10%, and the third value may be 20%. However, in the present invention, the first to third values ​​are not limited to the above examples.

[0083] exist Figure 7 FIG. 2 shows the duty cycle involved in the above-mentioned embodiment. That is, when the second initial driving power supply voltage VSS belongs to the first critical range THR1, as shown in FIG. Figure 7 As shown in (a), the duty cycle can be set to 2%. In addition, when the second initial driving power supply voltage VSS belongs to the second critical range THR2, as shown in FIG. Figure 7 As shown in (b), the duty cycle can be set to 10%. In addition, when the second initial driving power supply voltage VSS belongs to the third critical range THR3, as shown in FIG. Figure 7 As shown in (c), the duty cycle can be set to 20%.

[0084] Reference Figure 7 The higher the second initial driving power supply voltage VSS is, the higher the duty cycle will be. As the duty cycle increases, the non-luminous period NEP in one frame will be longer, and conversely, the luminous period EP will be shorter. In other words, in the present invention, the greater the offset of the second initial driving power supply voltage VSS determined for the display panel 100 is, the higher the duty cycle will be.

[0085] As described above, since the initial driving power supply voltage is determined according to the brightness and color coordinates of the display panel 100, a different initial driving power supply voltage can be determined for each display panel 100. In addition, since the duty cycle is determined corresponding to the initial driving power supply voltage, a different duty cycle can be determined for each display panel 100 based on its characteristics. As described above, the display device involved in the embodiment of the present invention can apply a different duty cycle to each display panel 100, thereby reducing the power consumption of the display panel 100 and improving the instantaneous afterimage.

[0086] Figure 8 1 is a flowchart showing a method for driving a display device according to the present invention.

[0087] Reference Figure 8 The display device according to the present invention can first determine the initial driving power supply voltage (VDD, VSS) (801).

[0088] The initial driving power supply voltage (VDD, VSS) may include a first initial driving power supply voltage VDD and a second initial driving power supply voltage VSS. The first initial driving power supply voltage VDD may be a high potential initial driving power supply voltage, and the second initial driving power supply voltage VSS may be a low potential initial driving power supply voltage.

[0089] The initial driving power supply voltage (VDD, VSS) can be determined based on the brightness and color coordinates of the display panel 100. The brightness and color coordinates of the display panel 100 can be determined based on the sample of the light-emitting element OLED provided in the display panel 100, the type and specification of the display device, the size of the display panel 100, etc. Figure 5 The initial driving power supply voltage (VDD, VSS) is determined by the curves of brightness and color coordinates shown in the figure.

[0090] Thereafter, the display device may apply a predetermined offset to the initial driving power supply voltage (VDD, VSS) to determine the final driving power supply voltage (ELVDD, ELVSS) (802). In one embodiment, the display device may determine an offset for the display panel 100 based on the lowest value of the second initial driving power supply voltage VSS of the various display panels 100, and apply the determined offset to the initial driving power supply voltage (VDD, V SS) to determine the final driving power supply voltage (ELVDD, ELVSS).

[0091] In addition, the display device can determine the duty cycle of the display panel 100 based on the initial driving power supply voltage (VDD, VSS) (803). For example, the display panel 100 can compare the second initial driving power supply voltage V SS with a preset critical value to determine the critical range to which the second initial driving power supply voltage VSS belongs. In addition, the display panel 100 can determine the preset duty cycle corresponding to the critical range to which the second initial driving power supply voltage VSS belongs. Here, the display panel 100 can increase the duty cycle as the low potential initial driving power supply voltage increases.

[0092] Thereafter, the display device may drive the display panel 100 using the determined final driving power supply voltage (ELVDD, ELVSS) and duty cycle (804).

[0093] On the other hand, Figure 8 The display device determines the duty cycle after determining the final driving power supply voltage (ELVDD, ELVSS) of the display panel 100, but the technical idea of ​​the present invention is not limited to this. That is, in various embodiments, the display device can first determine the duty cycle from the initial driving power supply voltage (VDD, VSS), and then determine the driving power supply voltage (ELVDD, ELVSS). Alternatively, in various embodiments, the display device can process the determination of the duty cycle and the driving power supply voltage (ELVDD, ELVSS) in parallel.

[0094] In various embodiments, the initial driving power supply voltage (VDD, VSS) and / or the driving power supply voltage (ELVDD, ELVSS) for the display panel 100 may be predetermined and stored in a process such as when manufacturing the display device, or may be received from the outside. In such an embodiment, the setting operation of the initial driving power supply voltage (VDD, VSS) and the driving power supply voltage (ELVDD, ELVSS) of the display device may be omitted, and the display device may determine the duty cycle based on the initial driving power supply voltage (VDD, VSS) stored or received from the outside as described above.

[0095] In various embodiments, the duty ratio determination method of the present invention may be performed by a device (e.g., an experimental device, a host device, etc.) configured outside the display device. In such an embodiment, the control unit 250 of the display device may receive a set duty ratio from the outside, and control the light-emitting driving unit 230 to output a light-emitting control signal in accordance with the received duty ratio.

[0096] In various embodiments, the duty cycle determination method of the present invention may be executed at least once before the initial light emission period of the display device (for example, before the product is sold). Alternatively, in various embodiments, the duty cycle determination method of the present invention may be executed at least once after the driving power is supplied to the display device (for example, after the power is turned on). Alternatively, in various embodiments, the duty cycle determination method of the present invention may be executed at least once during the vertical blank period within a frame.

[0097] Those skilled in the art to which the present invention belongs will understand that the present invention can be implemented in other specific forms without changing its technical ideas and essential features. Therefore, it should be understood that the embodiments described above are only illustrative and not restrictive in all aspects. The scope of the present invention is not reflected by the above detailed description, but by the scope of the claims, and should be interpreted as all changes or deformations derived from the meaning, scope and equivalent concepts of the scope of the claims are included in the scope of the present invention.

Claims

1. A display device, comprising: A display panel including a plurality of pixels; a control unit that determines a duty ratio according to an initial driving power supply voltage of the display panel, and controls light emission of the plurality of pixels according to the determined duty ratio; as well as a light-emitting driving unit that generates a light-emitting control signal based on the duty ratio and applies the light-emitting control signal to the plurality of pixels, The control unit determines different initial driving power supply voltages based on the brightness and color coordinates of the plurality of display panels. The control unit increases the duty ratio as a low potential initial driving power supply voltage for the plurality of display panels increases.

2. The display device according to claim 1, wherein: The control unit includes: a driving power supply voltage determination unit that determines the initial driving power supply voltage based on the brightness and the color coordinates of the display panel; and The duty ratio determination unit determines the duty ratio according to the initial driving power supply voltage.

3. The display device according to claim 2, wherein: The driving power supply voltage determination unit determines an offset based on the distribution of the initial driving power supply voltages for the plurality of display panels, and reflects the determined offset on the initial driving power supply voltage to determine a final driving power supply voltage.

4. The display device according to claim 3, further comprising: The power supply unit supplies power corresponding to the final driving power voltage to the display panel.

5. The display device according to claim 1, wherein: The light-emitting driving unit applies a light-emitting control signal of an off level to the multiple pixels during a non-light-emitting period within a frame determined by the duty cycle, and applies a light-emitting control signal of an on level to the multiple pixels during a light-emitting period within the frame determined by the duty cycle.

6. The display device according to claim 1, wherein: The initial driving power supply voltage is a low potential initial driving power supply voltage.

7. A method for driving a display device, comprising: The step of determining an initial driving power supply voltage based on the brightness and color coordinates of a display panel including a plurality of pixels; A step of determining a duty cycle corresponding to the determined initial driving power supply voltage; as well as a step of controlling light emission of the plurality of pixels corresponding to the determined duty ratio, The step of controlling the light emission of the plurality of pixels comprises: generating a light emitting control signal based on the duty cycle; and applying the light emitting control signal to the plurality of pixels, wherein different initial driving power supply voltages are determined based on the brightness and the color coordinates of a plurality of display panels, and The step of determining the duty ratio includes the step of increasing the duty ratio as the low potential initial driving power supply voltage for the plurality of display panels increases.

8. The method for driving a display device according to claim 7, further comprising: determining an offset based on a distribution of the initial driving power supply voltage for the plurality of display panels; The step of reflecting the determined offset on the initial driving power supply voltage to determine a final driving power supply voltage; as well as The step of supplying power corresponding to the final driving power voltage to the display panel.

9. The method for driving a display device according to claim 7, wherein: The step of applying the light emitting control signal comprises: A step of applying a light emitting control signal of an off level to the plurality of pixels during a non-light emitting period in one frame determined according to the duty ratio; and A step of applying a light emission control signal of an on level to the plurality of pixels during a light emission period in the one frame determined according to the duty ratio.

10. A method for driving a display device, comprising: The step of determining the initial driving power supply voltage of each of the plurality of display panels based on the brightness and color coordinates of each of the plurality of display panels; setting a plurality of duty ratios for each of the plurality of display panels corresponding to each of the determined initial driving power supply voltages; generating a plurality of light emission control signals based on the plurality of duty ratios for the respective display panels, and applying a corresponding light emission control signal among the plurality of light emission control signals to each of the plurality of display panels; as well as determining an offset based on the distribution of the initial driving power supply voltage, and reflecting the offset on the low potential initial driving power supply voltage for the plurality of display panels to determine a common driving power supply voltage for the plurality of display panels, and The common driving power supply voltage is a low potential driving power supply voltage, The step of setting the duty ratio includes the step of increasing the duty ratio as the low potential initial driving power supply voltage for the plurality of display panels increases.

11. The method for driving a display device according to claim 10, wherein: The common driving power supply voltage is determined as a lowest value of the initial driving power supply voltages.

12. The method for driving a display device according to claim 10, wherein: The offset is set to be proportional to a difference between the initial driving power supply voltage and the common driving power supply voltage.

13. The method for driving a display device according to claim 10, wherein: The different brightness and color coordinates are determined based on at least one of a sample of a light-emitting element included in each of the plurality of display panels and a type, specification, and size of the display device.

14. The method for driving a display device according to claim 10, wherein: The duty ratio is set to control the length of a light-emitting period and a non-light-emitting period in one frame for each of the plurality of display panels while the plurality of display panels are driven by applying the common driving power supply voltage.

15. The method for driving a display device according to claim 10, wherein: The step of setting the duty ratio of each of the plurality of display panels is performed before the initial driving of the display panel.

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