Display device and method of operating the same

Abstract

A display device and a method of operating the same are disclosed. The display device includes: a display panel including pixels; a gate driver that applies a gate signal to the pixels; a data driver applying a data voltage to the pixels; an emission driver that applies an emission signal to the pixels; and a power supply voltage generator receiving the sensing power supply voltage from the display panel and outputting the compensated power supply voltage to the display panel. The pixel includes: a driving transistor including a first control electrode receiving a data voltage, a second control electrode connected to the holding capacitor, a first electrode receiving a first power supply voltage, and a second electrode connected to the first electrode of the light emitting element; a holding capacitor including a first electrode receiving a compensation power supply voltage and a second electrode connected to a second control electrode of the driving transistor; and the light emitting element includes a first electrode receiving a first power supply voltage and a second electrode receiving a second power supply voltage.

Description

Technical Field

[0001] Embodiments of the inventive concept relate to a display device and a method of operating the display device. Background Art

[0002] Generally, a display device includes a display panel and a display panel driver. The display panel includes a plurality of gate lines, a plurality of data lines, a plurality of emission lines, a plurality of power supply voltage lines, and a plurality of pixels. The display panel driver includes a power supply voltage generator that provides a power supply voltage to the power supply voltage lines, a gate driver that provides a gate signal to the gate lines, a data driver that provides a data voltage to the data lines, an emission driver that provides an emission signal to the emission lines, and a drive controller that controls the gate driver, the data driver, and the emission driver. Summary of the invention

[0003] Embodiments of the inventive concept may provide a display device that reduces visibility of afterimages, bright lines, and dark lines of a display panel by generating a compensation power voltage in consideration of coupling through a power voltage generator.

[0004] Embodiments of the inventive concept also provide a method of operating the display device.

[0005] In an embodiment of a display device according to the concept of the present invention, the display device includes: a display panel including pixels; a gate driver configured to apply a gate signal to the pixels; a data driver configured to apply a data voltage to the pixels; an emission driver configured to apply an emission signal to the pixels; and a power supply voltage generator configured to receive a sensing power supply voltage from the display panel and configured to output a compensation power supply voltage to the display panel. The pixel includes: a driving transistor including a first control electrode receiving the data voltage, a second control electrode connected to a holding capacitor, a first electrode receiving a first power supply voltage, and a second electrode connected to a first electrode of a light-emitting element; the holding capacitor including a first electrode receiving the compensation power supply voltage and a second electrode connected to a second control electrode of the driving transistor; and the light-emitting element including a first electrode receiving the first power supply voltage and a second electrode receiving the second power supply voltage.

[0006] In an embodiment, the power supply voltage generator may include: a power supply voltage generating circuit configured to generate an initial power supply voltage; a voltage calculator configured to receive the initial power supply voltage and a sensed power supply voltage, and configured to output a calculated power supply voltage obtained by inversely amplifying a difference between the initial power supply voltage and the sensed power supply voltage; and a power supply voltage follower configured to receive the initial power supply voltage and the calculated power supply voltage, and configured to output a compensated power supply voltage.

[0007] In an embodiment, the voltage calculator may include: a first capacitor including a first electrode receiving a sensing power supply voltage and a second electrode connected to a first node; a first resistor including a first terminal connected to the first node and a second terminal connected to a third node; a second resistor including a first terminal connected to the third node and a second terminal connected to a fourth node; and an amplifier including a first input terminal connected to the third node, a second input terminal connected to the second node and receiving an initial power supply voltage, and an output terminal connected to the fourth node. The voltage of the fourth node is the calculation power supply voltage.

[0008] In an embodiment, the voltage calculator may further include a second capacitor connected to the second node.

[0009] In an embodiment, the fourth node may not be connected to a capacitor.

[0010] In an embodiment, the pixel may further include a reset transistor including a control electrode receiving a reset gate signal, a first electrode receiving a compensation reference voltage, and a second electrode connected to the first control electrode of the driving transistor. The compensation power supply voltage may be a compensation reference voltage.

[0011] In an embodiment, the first supply voltage may be a compensated first supply voltage. The compensated supply voltage may be a compensated first supply voltage.

[0012] In an embodiment, the emission signal may include a first emission signal and a second emission signal. The pixel may further include a first emission control transistor including a control electrode receiving the first emission signal, a first electrode receiving a compensated first power supply voltage, and a second electrode connected to the first electrode of the driving transistor.

[0013] In an embodiment, the sensing power supply voltage may be a sensing reference voltage. The compensation power supply voltage may be a compensation reference voltage. The first electrode of the holding capacitor may receive the compensation reference voltage.

[0014] In an embodiment, the sensing power supply voltage may be a sensing first power supply voltage. The compensating power supply voltage may be a compensating first power supply voltage. The first power supply voltage may be a compensating first power supply voltage. The first electrode of the holding capacitor may receive the compensating first power supply voltage.

[0015] In an embodiment, the pixel may further include a storage capacitor including a first electrode connected to the first control electrode of the driving transistor and a second electrode connected to the second electrode of the driving transistor.

[0016] In an embodiment, the pixel may further include an initialization transistor including a control electrode receiving an initialization gate signal, a first electrode receiving an initialization voltage, and a second electrode connected to the second electrode of the driving transistor.

[0017] In an embodiment, the emission signal may include a first emission signal and a second emission signal. The pixel may further include a second emission control transistor including a control electrode receiving the second emission signal, a first electrode connected to the second electrode of the driving transistor, and a second electrode connected to the first electrode of the light emitting element.

[0018] In an embodiment of a method for operating a display device according to the concept of the present invention, the method includes: generating an initial power supply voltage; receiving a sensing power supply voltage; generating a calculated power supply voltage obtained by inversely amplifying a difference between the initial power supply voltage and the sensing power supply voltage; and outputting a compensation power supply voltage to a second control electrode of a driving transistor of a pixel based on the initial power supply voltage and the calculated power supply voltage.

[0019] In an embodiment, the driving transistor may further include a first control electrode receiving a data voltage, a first electrode receiving a first power supply voltage, and a second electrode connected to the first electrode of the light emitting element. The second control electrode of the driving transistor may be connected to a holding capacitor. The pixel may further include: a write transistor configured to apply the data voltage to the driving transistor; the holding capacitor including a first electrode receiving a compensation power supply voltage and a second electrode connected to the second control electrode of the driving transistor; and the light emitting element including a first electrode receiving the first power supply voltage and a second electrode receiving the second power supply voltage.

[0020] In an embodiment, the sensing power supply voltage may be a sensing reference voltage. The compensation power supply voltage may be a compensation reference voltage. The first electrode of the holding capacitor may receive the compensation reference voltage.

[0021] In an embodiment, the sensing power supply voltage may be a sensing first power supply voltage. The compensating power supply voltage may be a compensating first power supply voltage. The first power supply voltage may be a compensating first power supply voltage. The first electrode of the holding capacitor may receive the compensating first power supply voltage.

[0022] In an embodiment, the pixel may further include a reset transistor including a control electrode receiving a reset gate signal, a first electrode receiving a compensation reference voltage, and a second electrode connected to the first control electrode of the driving transistor.

[0023] In an embodiment, the pixel may further include an initialization transistor including a control electrode receiving an initialization gate signal, a first electrode receiving an initialization voltage, and a second electrode connected to the second electrode of the driving transistor.

[0024] In an embodiment, the pixel may further include a storage capacitor including a first electrode connected to the first control electrode of the driving transistor and a second electrode connected to the second electrode of the driving transistor.

[0025] According to a display device and a method for operating the display device, the display device may include a power supply voltage generator. The power supply voltage generator may receive a sensing power supply voltage through a sensing voltage line. The power supply voltage generator may calculate a calculated power supply voltage by calculating the sensing power supply voltage and the initial power supply voltage. The power supply voltage generator may output a compensation power supply voltage to a display panel of the display device based on the calculated power supply voltage and the initial power supply voltage. Accordingly, by reflecting the power supply voltage change caused by the coupling of the data voltage, the compensation power supply voltage may be maintained constant. Accordingly, afterimages, bright lines, and dark lines may be reduced on the display panel. In addition, the stability and reliability of the pixels of the display panel may be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The above and other features and advantages of the present inventive concept will become more apparent by describing in detail embodiments of the present inventive concept with reference to the accompanying drawings, in which:

[0027] Figure 1 is a block diagram illustrating a display device according to an embodiment of the inventive concept;

[0028] Figure 2 The diagram shows Figure 1 A block diagram of an example of a display panel and a power supply voltage generator;

[0029] Figure 3 The diagram shows Figure 1 A circuit diagram of an example of a pixel;

[0030] Figure 4 The diagram shows Figure 2 A block diagram of an example of a power supply voltage generator;

[0031] Figure 5 The diagram shows Figure 4 An example circuit diagram of a reference voltage calculator;

[0032] Figure 6 The diagram shows Figure 4 An example circuit diagram of a reference voltage calculator;

[0033] Figure 7 is a graph illustrating changes in a reference voltage in a conventional display device;

[0034] Figure 8 The diagram shows Figure 4A graph of the calculated reference voltage and the compensated reference voltage;

[0035] Fig. 9 The diagram shows Figure 1 A block diagram of an example of a display panel and a power supply voltage generator;

[0036] Fig.10 The diagram shows Figure 1 A circuit diagram of an example of a pixel;

[0037] Fig.11 The diagram shows Figure 1 A block diagram of an example of a power supply voltage generator;

[0038] Fig.12 The diagram shows Fig.11 a circuit diagram of an example of a first power supply voltage calculator;

[0039] Fig.13 The diagram shows Fig.11 a circuit diagram of an example of a first power supply voltage calculator;

[0040] Fig.14 is a block diagram illustrating an electronic device according to an embodiment of the inventive concept; and

[0041] Fig.15 The diagram shows Fig.14 The electronic device is implemented as an example of a smart phone. DETAILED DESCRIPTION

[0042] Hereinafter, the inventive concept will be explained in detail with reference to the accompanying drawings.

[0043] Figure 1 is a block diagram illustrating a display device according to an embodiment of the inventive concept.

[0044] refer to Figure 1 The display device includes a display panel 100 and a display panel driver. In an embodiment, the display panel driver includes a driving controller 200, a gate driver 300, a gamma reference voltage generator 400, a data driver 500, an emission driver 600, and a power supply voltage generator 700.

[0045] The display panel 100 has a display area on which an image is displayed and a peripheral area adjacent to the display area.

[0046] The display panel 100 includes gate lines GWL, GRL, GIL, and GBL, data lines DL, and emission lines EML and EMBL, and pixels PX connected to the gate lines GWL, GRL, GIL, and GBL, data lines DL, and emission lines EML and EMBL. The gate lines GWL, GRL, GIL, and GBL may extend in a first direction D1. The data lines DL may extend in a second direction D2 intersecting the first direction D1. The emission lines EML and EMBL may extend in the first direction D1.

[0047] The driving controller 200 may receive input image data IMG and an input control signal CONT from an external device. For example, the input image data IMG may include red image data, green image data, and blue image data. For example, the input image data IMG may include white image data. For example, the input image data IMG may include magenta image data, yellow image data, and cyan image data. The input control signal CONT may include a main clock signal and a data enable signal. The input control signal CONT may further include a vertical synchronization signal and a horizontal synchronization signal.

[0048] The driving controller 200 may generate a first control signal CONT1 , a second control signal CONT2 , a third control signal CONT3 , a fourth control signal CONT4 , and a data signal DATA based on input image data IMG and an input control signal CONT.

[0049] The driving controller 200 generates a first control signal CONT1 for controlling the operation of the gate driver 300 based on the input control signal CONT, and outputs the first control signal CONT1 to the gate driver 300. The first control signal CONT1 may include a vertical start signal and a gate clock signal.

[0050] The driving controller 200 generates a second control signal CONT2 for controlling the operation of the data driver 500 based on the input control signal CONT, and outputs the second control signal CONT2 to the data driver 500. The second control signal CONT2 may include a horizontal start signal and a load signal.

[0051] The driving controller 200 generates a data signal DATA based on the input image data IMG. The driving controller 200 outputs the data signal DATA to the data driver 500.

[0052] The driving controller 200 generates a fourth control signal CONT4 for controlling the operation of the emission driver 600 based on the input control signal CONT, and outputs the fourth control signal CONT4 to the emission driver 600 .

[0053] The driving controller 200 generates a third control signal CONT3 for controlling the operation of the gamma reference voltage generator 400 based on the input control signal CONT, and outputs the third control signal CONT3 to the gamma reference voltage generator 400 .

[0054] The gate driver 300 generates gate signals GW, GR, GI and GB that drive the gate lines GWL, GRL, GIL and GBL, respectively, in response to the first control signal CONT1 received from the driving controller 200. The gate driver 300 may output the gate signals GW, GR, GI and GB to the gate lines GWL, GRL, GIL and GBL, respectively.

[0055] In an embodiment of the inventive concept, the gate driver 300 may be integrated on a peripheral area of ​​the display panel 100. In an embodiment of the inventive concept, the gate driver 300 may be mounted on a peripheral area of ​​the display panel 100.

[0056] The gamma reference voltage generator 400 generates the gamma reference voltage VGREF in response to the third control signal CONT3 received from the driving controller 200. The gamma reference voltage generator 400 provides the gamma reference voltage VGREF to the data driver 500. The gamma reference voltage VGREF has a value corresponding to each of the data signals DATA.

[0057] The gamma reference voltage generator 400 may be provided in the driving controller 200 or in the data driver 500 .

[0058] The data driver 500 receives the second control signal CONT2 and the data signal DATA from the driving controller 200, and receives the gamma reference voltage VGREF from the gamma reference voltage generator 400. The data driver 500 converts the data signal DATA into a data voltage VDATA having an analog type using the gamma reference voltage VGREF. The data driver 500 outputs the data voltage VDATA to the data line DL.

[0059] In an embodiment of the inventive concept, the data driver 500 may be integrated on a peripheral area of ​​the display panel 100. In an embodiment of the inventive concept, the data driver 500 may be mounted on a peripheral area of ​​the display panel 100.

[0060] The emission driver 600 may generate emission signals EM and EMB that respectively drive the emission lines EML and EMBL in response to the fourth control signal CONT4 received from the driving controller 200. The emission driver 600 may output the emission signals EM and EMB to the emission lines EML and EMBL, respectively.

[0061] In an embodiment of the inventive concept, the emission driver 600 may be integrated on a peripheral area of ​​the display panel 100. In an embodiment of the inventive concept, the emission driver 600 may be mounted on a peripheral area of ​​the display panel 100.

[0062] Although for ease of explanation, Figure 1 In the embodiment, the gate driver 300 is disposed on a first side of the display panel 100 and the emission driver 600 is disposed on a second side of the display panel 100, but the inventive concept is not limited thereto. The gate driver 300 and the emission driver 600 may be disposed on a first side of the display panel 100. For example, the gate driver 300 and the emission driver 600 may be disposed on a peripheral area of ​​the display panel 100 located on the same side of the display area of ​​the display panel 100. For example, the gate driver 300 and the emission driver 600 may be formed integrally with each other.

[0063] The power supply voltage generator 700 may output the power supply voltage to the display panel 100. For example, the power supply voltage may include a compensated first power supply voltage ELVDD, a second power supply voltage ELVSS, a compensated reference voltage VREF, an initialization voltage VINT, and a light emitting element initialization voltage VAINT. For example, the power supply voltage may be a DC voltage. In an embodiment, the power supply voltage generator 700 may include a power supply voltage generating circuit, a voltage calculator, and a power supply voltage follower. The power supply voltage generating circuit may be configured to generate an initial power supply voltage. The voltage calculator may be configured to receive an initial power supply voltage and a sensing power supply voltage, and may be configured to output a calculated power supply voltage obtained by reversely amplifying the difference between the initial power supply voltage and the sensing power supply voltage. The power supply voltage follower may be configured to receive an initial power supply voltage and a calculated power supply voltage, and may be configured to output a compensated power supply voltage. In the following embodiments, the power supply voltage generating circuit may be a reference voltage generator or a first power supply voltage generator, the voltage calculator may be a reference voltage calculator or a first power supply voltage calculator, and the power supply voltage follower may be a reference voltage follower or a first power supply voltage follower.

[0064] Figure 2 The diagram shows Figure 1 1 is a block diagram of an example of a display panel 100 and a power supply voltage generator 700.

[0065] refer to Figure 2In the present embodiment, the power supply voltage generator 700A may receive the sensing reference voltage VREFS from the display panel 100. The power supply voltage generator 700A may output the compensation reference voltage VREF to the display panel 100. For example, the display panel 100 may be connected to the power supply voltage generator 700A via a sensing reference voltage line and a reference voltage line. The display panel 100 may output the sensing reference voltage VREFS to the sensing reference voltage line. The power supply voltage generator 700A may output the compensation reference voltage VREF to the reference voltage line. In an embodiment, the reference voltage line may have a mesh structure. However, the inventive concept is not limited to the structure of the reference voltage line.

[0066] Figure 3 The diagram shows Figure 1 FIG. 1 is a circuit diagram of an example of a pixel PX.

[0067] refer to Figure 3 In this embodiment, the pixel PX-A may include 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, a storage capacitor Cst, a holding capacitor CHOLD, and a light emitting element EE.

[0068] The first transistor T1 may include a first control electrode connected to the first node P1, a second control electrode connected to the third node P3, a first electrode connected to the second node P2, and a second electrode connected to the third node P3. The first transistor T1 may output a driving current for driving the light emitting element EE in response to the voltage of the first node P1. For example, the first transistor T1 may be referred to as a driving transistor. In the present embodiment, the first transistor T1 may have a dual-gate structure.

[0069] The second transistor T2 may include a control electrode receiving a write gate signal GW, a first electrode receiving a data voltage VDATA, and a second electrode connected to the first node P1. The second transistor T2 may apply the data voltage VDATA to the first node P1 in response to the write gate signal GW. For example, the second transistor T2 may be referred to as a write transistor.

[0070] The third transistor T3 may include a control electrode receiving a reset gate signal GR, a first electrode receiving a compensation reference voltage VREF, and a second electrode connected to the first node P1. The third transistor T3 may apply the compensation reference voltage VREF to the first node P1 in response to the reset gate signal GR. For example, the third transistor T3 may be referred to as a reset transistor.

[0071] The fourth transistor T4 may include a control electrode receiving the initialization gate signal GI, a first electrode receiving the initialization voltage VINT, and a second electrode connected to the third node P3. The fourth transistor T4 may apply the initialization voltage VINT to the third node P3 in response to the initialization gate signal GI. For example, the fourth transistor T4 may be referred to as an initialization transistor.

[0072] The fifth transistor T5 may include a control electrode receiving the first emission signal EM, a first electrode receiving the compensated first power supply voltage ELVDD, and a second electrode connected to the second node P2. The fifth transistor T5 may apply the compensated first power supply voltage ELVDD to the second node P2 in response to the first emission signal EM. For example, the fifth transistor T5 may be referred to as a first emission control transistor.

[0073] The sixth transistor T6 may include a control electrode receiving the second emission signal EMB, a first electrode connected to the third node P3, and a second electrode connected to the fourth node P4. The sixth transistor T6 may apply the voltage of the third node P3 to the fourth node P4 in response to the second emission signal EMB. The sixth transistor T6 may apply a driving current to the light emitting element EE in response to the second emission signal EMB. For example, the sixth transistor T6 may be referred to as a second emission control transistor.

[0074] The seventh transistor T7 may include a control electrode receiving a light emitting element initialization gate signal GB, a first electrode receiving a light emitting element initialization voltage VAINT, and a second electrode connected to the fourth node P4. The seventh transistor T7 may apply the light emitting element initialization voltage VAINT to the fourth node P4 in response to the light emitting element initialization gate signal GB.

[0075] The storage capacitor Cst may include a first electrode connected to the first node P1 and a second electrode connected to the third node P3. The storage capacitor Cst may store a difference between a voltage of the first node P1 and a voltage of the third node P3.

[0076] The holding capacitor CHOLD may include a first electrode receiving the compensation reference voltage VREF and a second electrode connected to the third node P3. The holding capacitor CHOLD may improve reliability and stability of the pixel PX-A.

[0077] The light emitting element EE may include a first electrode (eg, an anode) connected to the fourth node P4 and a second electrode (eg, a cathode) receiving the second power voltage ELVSS. The light emitting element EE may emit light based on the driving current.

[0078] Figure 4 The diagram shows Figure 2 700A is a block diagram of an example of a power supply voltage generator 700A.

[0079] refer to Figures 1 to 4 In this embodiment, the power supply voltage generator 700A may include a reference voltage generator 710A, a reference voltage calculator 720A and a reference voltage follower 730A.

[0080] The reference voltage generator 710A may generate an initial reference voltage VREFI. The reference voltage generator 710A may apply the initial reference voltage VREFI to the reference voltage calculator 720A and the reference voltage follower 730A.

[0081] The reference voltage calculator 720A may receive an initial reference voltage VREFI. The reference voltage calculator 720A may receive a sensing reference voltage VREFS. The reference voltage calculator 720A may calculate a calculated reference voltage VREFC based on the initial reference voltage VREFI and the sensing reference voltage VREFS. The reference voltage calculator 720A may output the calculated reference voltage VREFC to the reference voltage follower 730A.

[0082] The reference voltage follower 730A may receive an initial reference voltage VREFI. The reference voltage follower 730A may receive a calculated reference voltage VREFC. The reference voltage follower 730A may generate a compensation reference voltage VREF based on the initial reference voltage VREFI and the calculated reference voltage VREFC. For example, the compensation reference voltage VREF may be the sum of the calculated reference voltage VREFC and the initial reference voltage VREFI. The reference voltage follower 730A may output the compensation reference voltage VREF to the display panel 100.

[0083] Figure 5 The diagram shows Figure 4 A circuit diagram of an example of the reference voltage calculator 720A.

[0084] refer to Figures 1 to 5 In this embodiment, the reference voltage calculator 720A may include a first capacitor C1, a first resistor R1, a second resistor R2, and an amplifier AMP.

[0085] The first capacitor C1 may include a first electrode receiving a sensing reference voltage VREFS and a second electrode connected to a first node N1. The first resistor R1 may include a first terminal connected to the first node N1 and a second terminal connected to a third node N3. The second resistor R2 may include a first terminal connected to the third node N3 and a second terminal connected to a fourth node N4. The amplifier AMP may include a first input terminal connected to the third node N3, a second input terminal receiving an initial reference voltage VREFI, and an output terminal connected to a fourth node N4. The reference voltage calculator 720A may output a voltage of the fourth node N4 as a calculated reference voltage VREFC. For example, the reference voltage calculator 720A may include an inverting amplifier.

[0086] In an embodiment, the fourth node N4 may not be connected to the capacitor. Accordingly, the reliability and stability of the reference voltage calculator 720A may be further improved. In addition, the accuracy of calculating the reference voltage VREFC may be further improved.

[0087] In a conventional display device, a reference voltage may be coupled to a data voltage according to a design pattern of a display panel. The reference voltage may be changed due to the coupling. The reference voltage is changed so that the voltage of the second control electrode of the driving transistor and the voltage of the source electrode may be changed. Accordingly, the driving transistor may fail. Due to the failure of the driving transistor, afterimages, bright lines, dark lines, etc. may be visible on the display panel.

[0088] In contrast, the power supply voltage generator 700A according to the present invention can receive the sensing reference voltage VREFS through the sensing reference voltage line. The power supply voltage generator 700A can calculate the calculation reference voltage VREFC based on the sensing reference voltage VREFS and the initial reference voltage VREFI. The power supply voltage generator 700A can output the compensation reference voltage VREF to the display panel 100 based on the calculation reference voltage VREFC and the initial reference voltage VREFI. Accordingly, by reflecting the voltage change caused by the coupling, the compensation reference voltage VREF can be maintained constant. Accordingly, afterimages, bright lines, and dark lines can be reduced. In addition, the stability and reliability of the pixel PX-A can be improved.

[0089] Figure 6 The diagram shows Figure 4 A circuit diagram of an example of the reference voltage calculator 720A.

[0090] Figure 6 The reference voltage calculator 720A-1 is Figure 5The reference voltage calculator 720A-1 is substantially the same as that of the reference voltage calculator 720A-1, except that the reference voltage calculator 720A-1 further includes a second capacitor C2, and thus the same reference numerals will be used to refer to the same elements, and repeated explanations regarding the above elements will be omitted.

[0091] refer to Figure 6 , the reference voltage calculator 720A-1 may further include a second capacitor C2 connected to the second node N2. Accordingly, the reliability and stability of the reference voltage calculator 720A-1 may be further improved. Accordingly, the accuracy of calculating the reference voltage VREFC may be improved. Accordingly, the accuracy of the compensation reference voltage VREF may be improved.

[0092] Figure 7 is a graph illustrating changes in a reference voltage in a conventional display device.

[0093] refer to Figure 7 In a conventional display device, the compensation reference voltage VREF may be changed due to coupling. For example, when the data voltage is changed from a data voltage corresponding to white to a data voltage corresponding to black, the compensation reference voltage VREF of the conventional display device may be the changed reference voltage VREF-ΔV1. Accordingly, afterimages, bright lines, and dark lines are visible on the display panel of the conventional display device.

[0094] Figure 8 The diagram shows Figure 4 A graph of the calculated reference voltage VREFC and the compensated reference voltage VREF.

[0095] refer to Figure 8 In this embodiment, the calculated reference voltage VREFC may be a value reflecting the voltage change caused by the coupling. For example, the calculated reference voltage VREFC may be a value in which the sensed reference voltage VREFS is reversely amplified. The compensated reference voltage VREF may be a value that takes into account the initial reference voltage VREFI and the calculated reference voltage VREFC. Accordingly, the compensated reference voltage VREF may be less affected by the coupling. For example, the compensated reference voltage VREF may have a compensated reference voltage VREF-ΔV2 that is changed due to the coupling. The changed compensated reference voltage VREF-ΔV2 may be lower than Figure 7 The changed reference voltage VREF-ΔV1 is obtained. Accordingly, the compensation reference voltage VREF can be maintained constant. Accordingly, afterimages, bright lines, and dark lines can be reduced. In addition, the stability and reliability of the pixel PX-A can be improved.

[0096] Fig. 9 The diagram shows Figure 1 1 is a block diagram of an example of a display panel 100 and a power supply voltage generator 700.

[0097] refer to Fig. 9 , the display panel 100 may include a first power voltage line ELVDDL and a sensing first power voltage line ELVDDSL. In the present embodiment, the power voltage generator 700B may receive the sensing first power voltage ELVDDS from the display panel 100. The power voltage generator 700B may output the compensating first power voltage ELVDD to the display panel 100. For example, the display panel 100 may be connected to the power voltage generator 700B through the sensing first power voltage line ELVDDSL and the first power voltage line ELVDDL. The display panel 100 may output the sensing first power voltage ELVDDS to the sensing first power voltage line ELVDDSL. The power voltage generator 700B may output the compensating first power voltage ELVDD to the first power voltage line ELVDDL. In an embodiment, the first power voltage line ELVDDL may have a mesh structure. However, the inventive concept is not limited to the structure of the first power voltage line ELVDDL.

[0098] Fig.10 The diagram shows Figure 1 FIG. 1 is a circuit diagram of an example of a pixel PX.

[0099] refer to Fig.10 , Fig.10 The pixel PX-B with Figure 3 The pixel PX-A is substantially the same except that the holding capacitor CHOLD does not receive the compensation reference voltage VREF but receives the compensation first power supply voltage ELVDD, and thus the same reference numerals will be used to refer to the same elements and repeated explanations regarding the above elements will be omitted.

[0100] Fig.11 The diagram shows Figure 1 700 is a block diagram of an example of a power supply voltage generator 700.

[0101] refer to Figure 1 as well as Figures 9 to 11 In this embodiment, the power supply voltage generator 700B may include a first power supply voltage generator 710B, a first power supply voltage calculator 720B and a first power supply voltage follower 730B.

[0102] The first power voltage generator 710B may generate an initial first power voltage ELVDDI. The first power voltage generator 710B may apply the initial first power voltage ELVDDI to the first power voltage calculator 720B and the first power voltage follower 730B.

[0103] The first power supply voltage calculator 720B may receive an initial first power supply voltage ELVDDI. The first power supply voltage calculator 720B may receive a sensed first power supply voltage ELVDDS. The first power supply voltage calculator 720B may calculate a calculated first power supply voltage ELVDDC based on the initial first power supply voltage ELVDDI and the sensed first power supply voltage ELVDDS. The first power supply voltage calculator 720B may output the calculated first power supply voltage ELVDDC to the first power supply voltage follower 730B.

[0104] The first power supply voltage follower 730B may receive an initial first power supply voltage ELVDDI. The first power supply voltage follower 730B may receive a calculated first power supply voltage ELVDDC. The first power supply voltage follower 730B may generate a compensated first power supply voltage ELVDD based on the initial first power supply voltage ELVDDI and the calculated first power supply voltage ELVDDC. For example, the compensated first power supply voltage ELVDD may be the sum of the calculated first power supply voltage ELVDDC and the initial first power supply voltage ELVDDI. The first power supply voltage follower 730B may output the compensated first power supply voltage ELVDD to the display panel 100.

[0105] Fig.12 The diagram shows Fig.11 1 is a circuit diagram of an example of the first power supply voltage calculator 720B.

[0106] refer to Fig.12 , Fig.12 The first power supply voltage calculator 720B and Figure 5 The reference voltage calculator 720A is basically the same, except that the first supply voltage calculator 720B does not receive the initial reference voltage VREFI but receives the initial first supply voltage ELVDDI and the first supply voltage calculator 720B does not receive the sensing reference voltage VREFS but receives the sensing first supply voltage ELVDDS, so the same figure numbers will be used to refer to the same elements, and repeated explanations about the above elements will be omitted.

[0107] refer to Fig.11In this embodiment, the power supply voltage generator 700B can receive the sensed first power supply voltage ELVDDS by sensing the first power supply voltage line ELVDDSL. The power supply voltage generator 700B can calculate the calculated first power supply voltage ELVDDC based on the sensed first power supply voltage ELVDDS and the initial first power supply voltage ELVDDI. The power supply voltage generator 700B can output the compensated first power supply voltage ELVDD to the display panel 100 based on the calculated first power supply voltage ELVDDC and the initial first power supply voltage ELVDDI. Accordingly, by reflecting the voltage change caused by coupling, the compensated first power supply voltage ELVDD can be maintained constant. Accordingly, afterimages, bright lines, and dark lines can be reduced. In addition, the stability and reliability of the pixel PX-B can be improved.

[0108] Fig.13 The diagram shows Fig.11 1 is a circuit diagram of an example of the first power supply voltage calculator 720B.

[0109] Fig.13 The first power supply voltage calculator 720B-1 is connected with Fig.12 The first power supply voltage calculator 720B is substantially the same as the first power supply voltage calculator 720B-1 except that the first power supply voltage calculator 720B-1 further includes a second capacitor C2, and thus the same reference numerals will be used to refer to the same elements and repeated explanations regarding the above elements will be omitted.

[0110] refer to Fig.13 , the first power supply voltage calculator 720B-1 may further include a second capacitor C2 connected to the second node N2. Accordingly, the reliability and stability of the first power supply voltage calculator 720B-1 may be further improved. Accordingly, the accuracy of calculating the first power supply voltage ELVDDC may be improved. Accordingly, the accuracy of compensating the first power supply voltage ELVDD may be improved.

[0111] Fig.14 is a block diagram illustrating an electronic device according to an embodiment of the inventive concept. Fig.15 The diagram shows Fig.14 The electronic device is implemented as an example of a smart phone.

[0112] refer to Fig.14 and Fig.15 , the electronic device 1000 may include a processor 1010, a memory device 1020, a storage device 1030, an input / output (I / O) device 1040, a power supply 1050, and a display device 1060. Here, the display device 1060 may be Figure 1In addition, the electronic device 1000 may further include a plurality of ports for communicating with a video card, a sound card, a memory card, a universal serial bus (USB) device, other electronic devices, and the like.

[0113] In an embodiment, Fig.15 As shown in the figure, the electronic device 1000 can be implemented as a smart phone. However, the electronic device 1000 is not limited thereto. For example, the electronic device 1000 can be implemented as a cellular phone, a video phone, a smart tablet, a smart watch, a tablet personal computer (PC), a car navigation system, a computer monitor, a laptop computer, and a head mounted display (HMD) device, etc.

[0114] The processor 1010 may perform various computing functions or various tasks. The processor 1010 may be a microprocessor, a central processing unit (CPU), an application processor (AP), etc. The processor 1010 may be coupled to other components via an address bus, a control bus, a data bus, etc. In addition, the processor 1010 may be coupled to an expansion bus such as a peripheral component interconnect (PCI) bus.

[0115] The processor 1010 can output the input image data IMG and the input control signal CONT to Figure 1 A drive controller 200 is provided.

[0116] The memory device 1020 may store data for the operation of the electronic device 1000. For example, the memory device 1020 may include at least one nonvolatile memory device and / or at least one volatile memory device, the nonvolatile memory device being, for example, an erasable programmable read-only memory (EPROM) device, an electrically erasable programmable read-only memory (EEPROM) device, a flash memory device, a phase change random access memory (PRAM) device, a resistive random access memory (RRAM) device, a nano-floating gate memory (NFGM) device, a polymer random access memory (PoRAM) device, a magnetic random access memory (MRAM) device, and a ferroelectric random access memory (FRAM) device, etc., and the volatile memory device being, for example, a dynamic random access memory (DRAM) device, a static random access memory (SRAM) device, and a mobile DRAM device, etc.

[0117] The storage device 1030 may include a solid state drive (SSD) device, a hard disk drive (HDD) device, a CD-ROM device, etc. The I / O device 1040 may include input devices such as a keyboard, a keypad, a mouse device, a touch pad, and a touch screen, etc., and output devices such as a printer and a speaker, etc. In some embodiments, a display device 1060 may be included in the I / O device 1040. The power supply 1050 may provide power for the operation of the electronic device 1000. The display device 1060 may be coupled to other components via a bus or other communication link.

[0118] The display apparatus according to the embodiment may be applied to a display device included in a computer such as a notebook computer, a mobile phone, a smart phone, a smart tablet, a PMP, a PDA, an MP3 player, or the like.

[0119] The foregoing is an illustration of the inventive concept and should not be construed as limiting it. Although embodiments of the inventive concept have been described, it will be readily appreciated by those skilled in the art that many modifications may be made in the embodiments without substantially departing from the novel teachings and advantages of the inventive concept. Accordingly, all of these modifications are intended to be included within the scope of the inventive concept as defined in the claims. In the claims, means plus function clauses are intended to cover structures described herein as performing the functions described, and not only structural equivalents, but also equivalent structures. Therefore, it should be understood that the foregoing is an illustration of the inventive concept and should not be construed as being limited to the specific embodiments disclosed, and modifications to the disclosed embodiments and other embodiments are intended to be included within the scope of the appended claims. The inventive concept is defined by the appended claims, which include the equivalents of the claims.

Claims

1. A display device, comprising: A display panel, including pixels; a gate driver configured to apply a gate signal to the pixel; a data driver configured to apply a data voltage to the pixel; an emission driver configured to apply an emission signal to the pixel; as well as a power supply voltage generator configured to receive a sensing power supply voltage from the display panel and configured to output a compensation power supply voltage to the display panel, Wherein, the pixels include: a driving transistor including a first control electrode configured to receive the data voltage, a second control electrode connected to the holding capacitor, a first electrode configured to receive a first power supply voltage, and a second electrode connected to the first electrode of the light emitting element; the holding capacitor comprising a first electrode configured to receive the compensation power supply voltage and a second electrode connected to the second control electrode of the driving transistor; and The light emitting element includes the first electrode configured to receive the first power supply voltage and the second electrode configured to receive the second power supply voltage.

2. The display device according to claim 1, wherein: The power supply voltage generator comprises: A power supply voltage generating circuit configured to generate an initial power supply voltage; a voltage calculator configured to receive the initial power supply voltage and the sensing power supply voltage, and configured to output a calculated power supply voltage obtained by inversely amplifying a difference between the initial power supply voltage and the sensing power supply voltage; and The power supply voltage follower is configured to receive the initial power supply voltage and the calculated power supply voltage, and is configured to output the compensated power supply voltage.

3. The display device according to claim 2, wherein: The voltage calculator comprises: a first capacitor including a first electrode configured to receive the sensing power supply voltage and a second electrode connected to a first node; a first resistor including a first terminal connected to the first node and a second terminal connected to a third node; a second resistor including a first terminal connected to the third node and a second terminal connected to a fourth node; and an amplifier including a first input terminal connected to the third node, a second input terminal connected to the second node, and an output terminal connected to the fourth node, the second input terminal being configured to receive the initial power supply voltage, and The voltage of the fourth node is the calculation power supply voltage.

4. The display device according to claim 3, wherein: The voltage calculator further comprises: A second capacitor is connected to the second node.

5. The display device according to claim 3, wherein: The fourth node is not connected to the capacitor.

6. The display device according to claim 3, wherein: The pixel further comprises: a reset transistor including a control electrode configured to receive a reset gate signal, a first electrode configured to receive a compensation reference voltage, and a second electrode connected to the first control electrode of the drive transistor, and Wherein, the compensation power supply voltage is the compensation reference voltage.

7. The display device according to claim 3, wherein: The first supply voltage is a compensated first supply voltage, and Wherein, the compensated power supply voltage is the compensated first power supply voltage.

8. The display device according to claim 7, wherein: The transmission signal includes a first transmission signal and a second transmission signal, and Wherein, the pixel further comprises: The first emission control transistor includes a control electrode configured to receive the first emission signal, a first electrode configured to receive the compensated first power supply voltage, and a second electrode connected to the first electrode of the driving transistor.

9. The display device according to claim 1, wherein: The sensing supply voltage is a sensing reference voltage, Wherein, the compensation power supply voltage is a compensation reference voltage, and Wherein, the first electrode of the holding capacitor is configured to receive the compensation reference voltage.

10. The display device according to claim 1, wherein: The sensing power supply voltage is sensing a first power supply voltage, Wherein, the compensation power supply voltage is to compensate the first power supply voltage, wherein the first power supply voltage is the compensated first power supply voltage, and Wherein, the first electrode of the holding capacitor is configured to receive the compensated first power supply voltage.

11. The display device according to claim 1, wherein: The pixel further comprises: A storage capacitor includes a first electrode connected to the first control electrode of the driving transistor and a second electrode connected to the second electrode of the driving transistor.

12. The display device according to any one of claims 1 to 11, wherein: The pixel further comprises: The initialization transistor includes a control electrode configured to receive an initialization gate signal, a first electrode configured to receive an initialization voltage, and a second electrode connected to the second electrode of the driving transistor.

13. The display device according to claim 1, wherein: The transmission signal includes a first transmission signal and a second transmission signal, and Wherein, the pixel further comprises: The second emission control transistor includes a control electrode configured to receive the second emission signal, a first electrode connected to the second electrode of the driving transistor, and a second electrode connected to the first electrode of the light emitting element.

14. A method for operating a display device, the method comprising: generating an initial power supply voltage; receiving a sense supply voltage; generating a calculated power supply voltage obtained by inversely amplifying a difference between the initial power supply voltage and the sensed power supply voltage; as well as A compensated power supply voltage is output to a second control electrode of a driving transistor of a pixel based on the initial power supply voltage and the calculated power supply voltage.

15. The method according to claim 14, wherein: The driving transistor further includes a first control electrode configured to receive a data voltage, a first electrode configured to receive a first power supply voltage, and a second electrode connected to the first electrode of the light emitting element, wherein the second control electrode of the driving transistor is connected to a holding capacitor, and Wherein, the pixel further comprises: a write transistor configured to apply the data voltage to the drive transistor; the holding capacitor comprising a first electrode configured to receive the compensation power supply voltage and a second electrode connected to the second control electrode of the driving transistor; and The light emitting element includes a first electrode configured to receive the first power supply voltage and a second electrode configured to receive a second power supply voltage.

16. The method according to claim 15, wherein: The sensing supply voltage is a sensing reference voltage, Wherein, the compensation power supply voltage is a compensation reference voltage, and Wherein, the first electrode of the holding capacitor is configured to receive the compensation reference voltage.

17. The method according to claim 15, wherein: The sensing power supply voltage is sensing a first power supply voltage, Wherein, the compensation power supply voltage is to compensate the first power supply voltage, wherein the first power supply voltage is the compensated first power supply voltage, and Wherein, the first electrode of the holding capacitor is configured to receive the compensated first power supply voltage.

18. The method according to claim 15, wherein: The pixel further comprises: The reset transistor includes a control electrode configured to receive a reset gate signal, a first electrode configured to receive a compensation reference voltage, and a second electrode connected to the first control electrode of the driving transistor.

19. The method according to claim 15, wherein: The pixel further comprises: The initialization transistor includes a control electrode configured to receive an initialization gate signal, a first electrode configured to receive an initialization voltage, and a second electrode connected to the second electrode of the driving transistor.

20. The method according to any one of claims 15 to 19, wherein: The pixel further comprises: A storage capacitor includes a first electrode connected to the first control electrode of the driving transistor and a second electrode connected to the second electrode of the driving transistor.

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