Display device

Abstract

A display device is provided. The display device includes a plurality of pixel blocks each including a plurality of pixels, a scan driver supplying a scan signal to a scan line and a control signal to a control line, a data driver supplying an image data voltage or a low gray data voltage to a data line, and a power supply supplying a reference voltage to the plurality of pixels, wherein the plurality of pixels are configured to receive the image data voltage during a first scan period of a frame and receive the low gray data voltage during a second scan period of the frame, and a reference voltage supplied to a first pixel row of at least one of the plurality of pixel blocks in the first scan period is different from a reference voltage supplied to a last pixel row of the at least one of the plurality of pixel blocks in the first scan period.

Description

[0001] This application claims priority to and the benefit of Korean Patent Application No. 10-2020-0024900, filed on February 28, 2020, in the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0002] Aspects of some example embodiments of the present application relate to a display device. BACKGROUND

[0003] The display device can perform a driving operation outside a pixel circuit by sensing a threshold voltage or mobility of a driving transistor included in the pixel circuit to compensate for degradation or change in characteristics of the driving transistor.

[0004] On the other hand, as the display resolution and driving frequency increase, when a video is displayed, it can cause inconvenience in viewing the video such as recognizing motion blur (i.e., motion trailing). In order to improve or alleviate the motion blur phenomenon, a technique of inserting a black image between frames can be utilized.

[0005] The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention, and therefore, it can contain information that does not constitute prior art. SUMMARY

[0006] Aspects of some example embodiments of the present application include a display device that supplies a reference voltage supplied to a pixel differently according to a pixel row in a unit of a pixel block.

[0007] Aspects of some example embodiments of the present application include a display device that supplies an image data voltage of the same grayscale differently according to a pixel row in a unit of a pixel block.

[0008] However, the characteristics according to the embodiments of the present application are not limited to the above-described characteristics, but can be variously extended within the scope of the spirit and range of the present application.

[0009] A display apparatus according to some example embodiments of the present invention includes a plurality of pixel blocks each including a plurality of pixels connected to a scan line, a control line, and a data line; a scan driver supplying a scan signal to the scan line and a control signal to the control line; a data driver supplying an image data voltage or a low gray data voltage to the data line; and a power supply supplying a reference voltage to the plurality of pixels. The plurality of pixels can receive the image data voltage during a first scan period of a frame and receive the low gray data voltage during a second scan period of the frame. The reference voltage supplied to a first pixel row of at least one of the plurality of pixel blocks in the first scan period is different from the reference voltage supplied to a last pixel row of at least one of the plurality of pixel blocks in the first scan period.

[0010] According to some example embodiments of the present invention, the reference voltage supplied to the first pixel row in the first scan period is greater than the reference voltage supplied to the last pixel row in the first scan period. The low gray data voltage can be an image data voltage corresponding to a black gray.

[0011] According to some example embodiments of the present invention, a first scan period for a pixel row included in a first pixel block of the plurality of pixel blocks can be sequentially activated during a first period, and a second scan period for the pixel row included in the first pixel block can be simultaneously activated at the same time.

[0012] According to some example embodiments of the present invention, the power supply can gradually decrease the reference voltage during the first period.

[0013] According to some example embodiments of the present invention, the power supply can repeat the change of the reference voltage of the first period for each of the plurality of pixel blocks.

[0014] According to some example embodiments of the present invention, each of the plurality of pixel blocks can include consecutive k pixel rows (k is an integer greater than 1).

[0015] According to some example embodiments of the present invention, the display apparatus can further include first to k-th power supply lines connected to the first to k-th pixel rows of each of the plurality of pixel blocks, respectively, and transmitting the reference voltage of different voltage levels from the power supply.

[0016] According to some example embodiments of the present invention, the j-th power supply line can be connected to the j-th pixel row of each of the plurality of pixel blocks (j is an integer greater than or equal to 1 and less than or equal to k).

[0017] According to some example embodiments of the present application, the scan driver can sequentially supply a scan signal to scan lines among the scan lines included in a p-th pixel block (p is a positive integer) during a first period, and can simultaneously supply a scan signal to scan lines among the scan lines included in a q-th pixel block (q is a positive integer different from p) during the first period.

[0018] According to some example embodiments of the present application, each of the plurality of pixels can include: a light emitting element; a first transistor connected between a first driving power supply and the light emitting element, and having a gate electrode connected to a first node; a second transistor connected between one of the data lines and the first node, and having a gate electrode receiving a scan signal; a third transistor supplying a reference voltage to a second node in response to a control signal supplied to a gate electrode of the third transistor, the first transistor and the light emitting element being connected to the second node; and a storage capacitor connected between the first node and the light emitting element.

[0019] According to some example embodiments of the present application, the second transistor and the third transistor can be turned on during a first scan period, and the second transistor can be turned on during a second scan period.

[0020] According to some example embodiments of the present application, the data driver can supply a first image data voltage corresponding to a first gray level to a first pixel row of each of the plurality of pixel blocks and a last pixel row of each of the plurality of pixel blocks at different voltage levels.

[0021] According to some example embodiments of the present application, the first image data voltage supplied to the first pixel row of each of the plurality of pixel blocks can be less than the first image data voltage supplied to the last pixel row of each of the plurality of pixel blocks.

[0022] According to some example embodiments of the present application, the data driver can gradually increase the first image data voltage from the first pixel row of each of the plurality of pixel blocks to the last pixel row of each of the plurality of pixel blocks.

[0023] According to some example embodiments of the present application, the display apparatus can further include: a gamma tap voltage generator controlling a gamma tap voltage output in the pixel row of each of the plurality of pixel blocks; and a gamma voltage generator generating a gamma voltage corresponding to the pixel row based on the gamma tap voltage.

[0024] A display apparatus according to some example embodiments of the present application includes a plurality of pixel blocks each including a plurality of pixels connected to a scan line, a control line, a data line, and a sensing line; a scan driver supplying a scan signal to the scan line and a control signal to the control line; a data driver supplying an image data voltage or a low gray data voltage to the data line; and a power supply supplying a reference voltage to the plurality of pixels through the sensing line. Each of the plurality of pixels can receive the image data voltage during a first scan period of a frame and receive the low gray data voltage during a second scan period of the frame. The image data voltage supplied to a first pixel row of at least one of the plurality of pixel blocks is less than the image data voltage supplied to a last pixel row of at least one of the plurality of pixel blocks. The image data voltage supplied to the first pixel row and the image data voltage supplied to the last pixel row both correspond to a first gray.

[0025] According to some example embodiments of the present application, the data driver can gradually increase the image data voltage of the first gray from a first pixel row of each of the plurality of pixel blocks to a last pixel row of each of the plurality of pixel blocks. The low gray data voltage can be an image data voltage corresponding to a black gray.

[0026] According to some example embodiments of the present application, the display apparatus can further include a gamma tap voltage generator decreasing a gamma tap voltage as the pixel row included in each of the plurality of pixel blocks is sequentially selected, and a gamma voltage generator generating a gamma voltage corresponding to the pixel row based on the gamma tap voltage.

[0027] According to some example embodiments of the present application, the power supply can decrease the reference voltage as the pixel row included in each of the plurality of pixel blocks is sequentially selected.

[0028] According to some example embodiments of the present application, a light emission time of the first pixel row of each of the plurality of pixel blocks can be longer than a light emission time of the last pixel row of each of the plurality of pixel blocks. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is a block diagram illustrating a display apparatus according to some example embodiments of the present application.

[0030] Figure 2 is a circuit diagram illustrating an example of a pixel included in the display apparatus of Figure 1 .

[0031] Figure 3 is a waveform diagram illustrating an example of an operation of the pixel of Figure 2 .

[0032] Figure 4 is a schematic view illustrating a display apparatus according to some example embodiments of the present application. Figure 1A diagram illustrating the driving method of a display device.

[0033] Figure 5 It is shown that... Figure 4 A diagram showing a portion of the emission time of the pixel row corresponding to part A.

[0034] Figure 6 It is shown Figure 1 A waveform diagram illustrating an example of the operation of a display device.

[0035] Figure 7 It is used for explanation Figure 6 The graph shows the change in the reference voltage.

[0036] Figure 8 It is shown that it includes Figure 1 A diagram illustrating an example of the setup of a power line supplying a reference voltage in a display device.

[0037] Figure 9 It is shown that it includes Figure 1 A diagram illustrating an example of the setup of a power line supplying a reference voltage in a display device.

[0038] Figure 10 It shows the supply to Figure 9 A diagram showing an example of the voltage level of the reference voltage for the power line.

[0039] Figure 11 It is shown Figure 1 A waveform diagram illustrating an example of the operation of a display device.

[0040] Figure 12 It is shown in detail Figure 11 The image data shows the change in voltage.

[0041] Figure 13 It is shown Figure 1 A block diagram illustrating a partial structure of a display device.

[0042] Figure 14 This is a diagram showing an example of setting the gamma tap voltage in a pixel row.

[0043] Figure 15 This shows the settings. Figure 14 A diagram illustrating an example of the construction of a gamma tap voltage.

[0044] Figure 16 It is shown that it includes Figure 1 A diagram illustrating an example of the arrangement of drive power lines supplying the voltage of the first drive power supply in a display device.

[0045] Figure 17 It shows including Figure 16 A diagram illustrating an example of the operation of a display device that drives power lines.

[0046] Figure 18 is a diagram illustrating an example of a setting of a driving power line supplying a voltage of a second driving power source included in a display device of Figure 1

[0047] Figure 19 is a diagram illustrating an example of an operation of a display device including a driving power line of Figure 18

[0048] Figure 20 is a block diagram illustrating a display device according to some example embodiments of the present application.

[0049] Figure 21 is a circuit diagram illustrating an example of a pixel included in a display device of Figure 20 DETAILED DESCRIPTION

[0050] Hereinafter, aspects of some example embodiments of the present application will be described in greater detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used for the same constituent elements and repetitive descriptions are omitted. Also, descriptions of similar reference numerals for similar constituent elements are omitted.

[0051] Figure 1 is a block diagram illustrating a display device according to some example embodiments of the present application.

[0052] Referring to Figure 1 , the display device 1000 can include a pixel unit 100, a scan driver 200, a data driver 300, a power source 500, and a timing controller 600.

[0053] The display device 1000 can be a flat panel display device, a flexible display device, a curved display device, a foldable display device, a bendable display device, or a stretchable display device. In addition, the display device 1000 can be applied to a transparent display device, a head-mounted display device, a wearable display device, etc. In addition, the display device 1000 can be applied to various electronic devices such as a smart phone, a tablet, a smart pad, a TV, a monitor, etc.

[0054] Meanwhile, the display device 1000 can be implemented as an organic light emitting diode display device, a liquid crystal display device, etc. However, this is merely an example, and the configuration of the display device 1000 is not limited thereto. For example, the display device 1000 can be a self-emissive display device including an inorganic light emitting element.

[0055] ​​​According to some example embodiments, the display apparatus 1000 can be driven by being divided into a display period for displaying an image and a sensing period for sensing a characteristic of a driving transistor and / or a light emitting element included in each of the pixels PX. Since the main feature of the present application is driving and operation during the display period, this will be mainly described.

[0056] According to some example embodiments, the display apparatus 1000 can further include a sensing circuit (e.g., 400 in FIG. 1) for calculating a characteristic of the pixels PX and generating a compensation value of the pixels PX. Figure 20 For example, a configuration or a function of at least a part of the sensing circuit can be integrated into the data driver 300.

[0057] The pixel unit 100 can include the pixels PX disposed to be connected to data lines DL1 to DLm (here, m is a natural number), scan lines SL1 to SLn (here, n is a natural number), and a power line PL (e.g., a reference power line or an initialization power line).

[0058] According to some example embodiments, each of the pixels PX can further be connected to a sensing line for extracting a sensing value. The sensing line can be electrically connected to the pixels PX alternately with the power line PL through a switching operation (see Figure 20 and Figure 21 ).

[0059] The pixels PX can receive voltages of the first driving power source VDD and the second driving power source VSS from an external source.

[0060] Meanwhile, Figure 1 n scan lines SL1 to SLn are illustrated, but embodiments according to the present application are not limited thereto. For example, at least one control line, a scan line, a sensing line, etc. can be additionally formed in the circuit structure corresponding to the pixels PX in the pixel unit 100.

[0061] According to some example embodiments, the transistor included in the pixels PX can be an N-type oxide thin film transistor. For example, the oxide thin film transistor can be a low temperature polyoxide (LTPO) thin film transistor. However, this is merely an example, and the N-type transistor is not limited thereto. For example, an active pattern (e.g., a semiconductor layer) included in the transistor can include an inorganic semiconductor (e.g., amorphous silicon, polycrystalline silicon) or an organic semiconductor. In addition, at least one of the transistors included in the display apparatus 1000 can be replaced with a P-type transistor.

[0062] According to some example embodiments, the pixel unit 100 can include a plurality of pixel blocks BL1, BL2, and BL3. Each of the pixel blocks BL1, BL2, and BL3 can include a set or predetermined number of pixel rows. For example, according to some example embodiments, each of the pixel blocks BL1, BL2, and BL3 can include eight pixel rows. However, this is merely an example, and the number of pixel rows included in each of the pixel blocks BL1, BL2, and BL3 is not limited thereto. For example, according to some example embodiments, the number of pixel rows included in each of the pixel blocks BL1, BL2, and BL3 can be more than eight or less than eight.

[0063] Meanwhile, the black image insertion driving can be performed in units of the pixel blocks BL1, BL2, and BL3. According to some example embodiments, a low gray data voltage (or referred to as a black data voltage) can be simultaneously supplied to the pixel rows included in each of the pixel blocks BL1, BL2, and BL3, and then a black image can be displayed in the corresponding pixel block during a certain period (e.g., a set or predetermined period).

[0064] The timing controller 600 can generate a data driving control signal DCS, a scan driving control signal SCS, and a power driving control signal PCS in response to a synchronization signal supplied from the outside. The data driving control signal DCS generated by the timing controller 600 can be supplied to the data driver 300, the scan driving control signal SCS can be supplied to the scan driver 200, and the power driving control signal PCS can be supplied to the power source 500.

[0065] In addition, the timing controller 600 can supply image data RGB to the data driver 300, in which input image data supplied from the outside is re-set.

[0066] The data driving control signal DCS can include a source start signal and a clock signal. The source start signal can control a sampling start point of data. The clock signal can be used to control a sampling operation.

[0067] The scan driving control signal SCS can include a scan start signal, a control start signal, and a clock signal. The scan start signal can control a timing of a scan signal. The control start signal can control a timing of a control signal. The clock signal can be used to shift the scan start signal and / or the control start signal.

[0068] The power driving control signal PCS can control a voltage level or a supply point of a reference voltage Vint (or an initialization voltage).

[0069] According to some example embodiments, the timing controller 600 can detect a change in a characteristic of the driving transistor based on the current or voltage extracted from the pixel PX during the sensing period. The timing controller 600 can calculate a compensation value for compensating the input image data based on the detected change in the characteristic. In addition, the timing controller 600 can compensate the input image data based on the compensation value to supply the image data RGB.

[0070] The scan driver 200 can receive a scan driving control signal SCS from the timing controller 600. The scan driver 200 receiving the scan driving control signal SCS can supply a scan signal to the scan lines SL1 to SLn and supply a control signal to the control lines CL1 to CLn.

[0071] For example, the scan driver 200 can sequentially supply the scan signal to the scan lines SL1 to SLn. When the scan signal is sequentially supplied to the scan lines SL1 to SLn, the pixel PX can be selected in units of a horizontal line. For this purpose, the scan signal can be set to a gate-on voltage (e.g., a logic high level) so that the transistor included in the pixel PX can be turned on.

[0072] Similarly, the scan driver 200 can supply the control signal to the control lines CL1 to CLn. The control signal can be used to sense (or extract) a driving current (i.e., a current flowing through the driving transistor) flowing through the pixel PX. The timing and the waveform in which the scan signal and the control signal are supplied can be differently set according to a display period and a sensing period.

[0073] Meanwhile, in Figure 1 In the above-described embodiment, one scan driver 200 is illustrated as outputting both the scan signal and the control signal, but embodiments according to the present application are not limited thereto. For example, the scan driver 200 can include a first scan driver that supplies the scan signal to the pixel unit 100 and a second scan driver that supplies the control signal to the pixel unit 100. That is, the first scan driver and the second scan driver can be implemented in separate configurations.

[0074] The data driver 300 can receive a data driving control signal DCS from the timing controller 600. The data driver 300 can supply an image data voltage to the pixel unit 100 during a first scan period of one frame period of each of the pixels. In addition, the data driver 300 can supply a black data voltage to the pixel unit 100 during a second scan period of one frame period. At this time, the image data voltage can be a data voltage for displaying an effective image (i.e., a data voltage corresponding to the image data RGB), and the black data voltage can be a data voltage corresponding to a black gray scale.

[0075] As described above, according to some example embodiments, the data driver 300 can function as a sensing circuit. For example, a current or a voltage extracted from the pixel PX during a sensing period can be supplied to the data driver 300 through a data line (at least one data line among the data lines DL1 to DLm corresponding to the corresponding pixel). The sensing circuit included in the data driver 300 can calculate a sensing value based on the extracted current / voltage. That is, Figure 20 The functions of the sensing lines SSL1 to SSLm can be performed through the data lines DL1 to DLm.

[0076] The power supply 500 can supply the reference voltage Vint to the pixels PX through the power line PL based on the power driving control signal PCS. According to some example embodiments, the power line PL can be commonly connected to all the pixels PX. For example, the power line PL can be patterned within the display panel while being overlaid with the pixel unit 100.

[0077] According to some example embodiments, during a period in which the scan signal is sequentially supplied to the first pixel block BL1, the power supply 500 can gradually decrease the reference voltage Vint. Similarly, for each of the other pixel blocks BL2 and BL3, during a period in which the scan signal is sequentially supplied, the power supply 500 can gradually decrease the reference voltage Vint.

[0078] Figure 2 is a circuit diagram illustrating an example of a pixel included in a display apparatus of Figure 1 and Figure 3 is a waveform diagram illustrating an example of an operation of the pixel of Figure 2 .

[0079] In Figure 2 and Figure 3 , for better understanding and ease of description, a pixel PXij disposed on an i-th horizontal line and connected to a j-th data line DLj will be illustrated.

[0080] Referring to Figure 2 and Figure 3 , the pixel PXij can include a light emitting element LD, a first transistor T1 (or a driving transistor), a second transistor T2, a third transistor T3, and a storage capacitor Cst.

[0081] A first electrode (anode or cathode) of the light emitting element LD is connected to the second node N2, and a second electrode (cathode or anode) is connected to the second driving power VSS. The light emitting element LD generates light of a set or predetermined brightness in response to an amount of current supplied from the first transistor T1 (e.g., a driving transistor).

[0082] The first electrode of the first transistor T1 can be connected to the first driving power source VDD, and the second electrode of the first transistor T1 can be connected to the first electrode of the light emitting element LD. The gate electrode of the first transistor T1 can be connected to the first node N1. The first transistor T1 controls the amount of current flowing to the light emitting element LD in response to the voltage of the first node N1.

[0083] The first electrode of the second transistor T2 can be connected to the data line DLj, and the second electrode can be connected to the first node N1. The gate electrode of the second transistor T2 can be connected to the scan line SLi. The second transistor T2 can be turned on when a scan signal is supplied to the scan line SLi to transmit a data voltage from the data line DLj to the first node N1.

[0084] The third transistor T3 can be connected between the power line PL and the second electrode (i.e., the second node N2) of the first transistor T1. The gate electrode of the third transistor T3 can be connected to the control line CLi. The third transistor T3 can be turned on when a control signal is supplied to the control line CLi to electrically connect the power line PL and the second node N2 (i.e., the second electrode of the first transistor T1).

[0085] According to some example embodiments, when the third transistor T3 is turned on, a reference voltage Vint can be supplied to the second node N2 through the power line PL. The reference voltage Vint can be used to set the voltage of the second electrode (e.g., the source electrode) of the first transistor T1 to a predetermined value or to initialize the voltage of the second electrode (e.g., the source electrode) of the first transistor T1. Accordingly, the reliability of the driving current generated from the first transistor T1 can be improved.

[0086] According to some example embodiments, when the third transistor T3 is turned on, the current generated in the first transistor T1 can be supplied to the sensing circuit or the timing controller 600 (see Figure 1 ) through a sensing line (not shown).

[0087] According to some example embodiments, when the second transistor T2 is turned on, the current generated in the first transistor T1 can be supplied to the sensing circuit or the timing controller 600 (see Figure 1 ) through the data line DLj.

[0088] The storage capacitor Cst can be connected between the first node N1 and the second node N2. The storage capacitor Cst can store a voltage corresponding to the voltage difference between the first node N1 and the second node N2.

[0089] On the other hand, the circuit structure of the pixel PXij according to some example embodiments of the present application is not limited to Figure 2For example, the light emitting element LD can be provided between the first driving power source VDD and the first electrode of the first transistor T1. Also, in Figure 2 The transistors T1 to T3 are illustrated as NMOS, but embodiments according to the present application are not limited thereto. For example, at least one of the transistors T1 to T3 can be formed of PMOS.

[0090] As illustrated in FIG. 1, one frame 1Frame can include a first scan period SP1, a display period DP, a second scan period SP2, and a black insertion period BIP. Figure 3 As illustrated in FIG. 1, one frame 1Frame can include a first scan period SP1, a display period DP, a second scan period SP2, and a black insertion period BIP.

[0091] During the first scan period SP1, a scan signal and a control signal can be supplied to the scan line SLi and the control line CLi, respectively. Also, an image data voltage Dj can be supplied to the data line DLj during the first scan period SP1. Then, the second transistor T2 can be turned on to supply the image data voltage Dj to the first node N1, and the third transistor T3 can be turned on to supply the reference voltage Vint to the second node N2.

[0092] Accordingly, a voltage amount corresponding to a difference between the image data voltage Dj and the reference voltage Vint can be stored in the storage capacitor Cst.

[0093] Next, the second transistor T2 and the third transistor T3 can be turned off during the display period DP. The light emitting element LD can emit light having a luminance corresponding to the voltage stored in the storage capacitor Cst. A substantial effective image to be displayed can be displayed during the display period DP.

[0094] Next, a scan signal can be supplied to the scan line SLi during the second scan period SP2. Also, a black data voltage Bdata can be supplied to the data line DLj during the second scan period SP2. Then, the second transistor T2 can be turned on to supply the black data voltage Bdata to the first node N1.

[0095] Next, the second transistor T2 can be turned off during the black insertion period BIP, and the light emitting element LD can display a black image. When the pixel PXij displays a video, a response time of the pixel PXij can increase due to a sudden change in the data voltage. Due to the increase in the response time, motion blur can be visually recognized by a user, and the motion blur of the video can be improved by inserting a black image during a short black insertion period BIP between display images between frames.

[0096] During one frame 1Frame, a length of the display period DP and a length of the black insertion period BIP can be determined as optimal values by factors such as an image change speed, a frequency, etc.

[0097] Figure 4 is a diagram schematically showing Figure 1 a driving method of a display device.

[0098] Referring to Figure 2 to Figure 4 , the display device 1000 (see Figure 1 ) can supply (or write) both the image data voltage Dj and the black data voltage Bdata to the first to nth pixel rows PR1 to PRn during one frame 1F (frame). That is, the display device 1000 (see Figure 1 ) can insert a black image without increasing a frame rate.

[0099] According to some example embodiments, as shown in Figure 4 , the operation during one frame 1F of the first pixel row PR1 can be divided into an operation during a display period DP and an operation during a black insertion period BIP. The first pixel row PR1 can emit light having a luminance corresponding to the image data voltage Dj during the display period DP and output a black image during the black insertion period BIP.

[0100] Meanwhile, a scan signal for displaying an image during the display period DP can be sequentially supplied to the entire pixel unit 100 (see Figure 1 ). Accordingly, the display period DP can be sequentially started in units of pixel rows.

[0101] A scan signal for inserting a black image during the black insertion period BIP can be simultaneously or concurrently supplied in units of the pixel blocks BL1, BL2, and BL3 (see Figure 1 ). For example, the scan signal is simultaneously or concurrently supplied to the pixel rows of the first pixel block BL1 (see Figure 1 ) so that the black data voltage Bdata can be simultaneously or concurrently written. Accordingly, the black insertion period BIP of the pixel rows of the first pixel block BL1 can be simultaneously or concurrently started.

[0102] Next, the black data voltage Bdata can be simultaneously written to the pixel rows of the second pixel block BL2 (see Figure 1 ) after a certain time period (e.g., a set or predetermined time period) elapses. Similarly, the same driving can be performed for other pixel blocks at a certain time interval (e.g., a set or predetermined time interval). As such, the black insertion period BIP can be sequentially started in units of pixel blocks.

[0103] Figure 5 is a diagram showing a portion of a light emission time of a pixel row corresponding to the A portion of Figure 4 .

[0104] Referring toFigure 2 to Figure 5 The display period DP of each of the pixel rows PR1 to PR8 included in the first pixel block BL1 can be different.

[0105] According to some example embodiments, as Figure 5 indicated in FIG. 1, one pixel block can include eight pixel rows. For example, the first pixel block BL1 can include the first pixel row PR1 to the eighth pixel row PR8. However, this is merely an example, and the number of pixel rows included in a pixel block is not limited thereto.

[0106] As described with reference to Figure 4 , the display periods DP in the first pixel block BL1 can be sequentially performed in the order of the first pixel row PR1 to the eighth pixel row PR8. After the display periods DP, the black insertion period BIP can be performed simultaneously. Thus, the emission times T(1) to T(8) of each of the first pixel row PR1 to the eighth pixel row PR8 can be different from each other. For example, as indicated in Figure 5 , the length of the emission times can decrease from the first pixel row PR1 to the eighth pixel row PR8.

[0107] The emission times are generally proportional to the display luminance. Thus, the display luminance can decrease from the first pixel row PR1 to the eighth pixel row PR8.

[0108] On the other hand, the second pixel block BL2 can perform substantially the same operation as the first pixel block BL1 with a time difference from the first pixel block BL1. Thus, the emission time T(9) of the ninth pixel row PR9 can be substantially the same as the emission time T(1) of the first pixel row PR1. The emission times T(10) and T(11) of the tenth pixel row PR10 and the eleventh pixel row PR11 can be substantially the same as the emission times T(2) and T(3) of the second pixel row PR2 and the third pixel row PR3, respectively.

[0109] Thus, a sharp difference in the emission times and the display luminance can occur between the emission time T(8) of the last pixel row (i.e., the eighth pixel row PR8) of the first pixel block BL1 and the emission time T(9) of the first pixel row (i.e., the ninth pixel row PR9) of the second pixel block BL2. The difference in the display luminance between the eighth pixel row PR8 and the ninth pixel row PR9 can be recognized as a large difference to a user due to the Mach band effect. Thus, a configuration for minimizing or eliminating such a difference in the perceptible luminance due to driving the inserted black image in units of pixel blocks is needed.

[0110] For example, the display luminance can be proportional to a drive transistor (e.g., a data line driver) included in a pixel PX. Figure 2The driving current of the first transistor T1 in the first pixel row PR1 and the driving current of the first transistor T1 in the eighth pixel row PR8 are proportional to the driving current of the first transistor T1 in the first pixel row PR1 and the driving current of the first transistor T1 in the eighth pixel row PR8, respectively, and the light emission time. Accordingly, for the same gray scale or the same image data voltage, when the driving current at the pixels of the eighth pixel row PR8 is greater than the driving current at the pixels of the ninth pixel row PR9, the brightness difference between the eighth pixel row PR8 and the ninth pixel row PR9 can be reduced. In addition, by reducing the brightness difference between the first pixel row PR1 and the eighth pixel row PR8, the brightness difference between the boundaries of the pixel blocks and the brightness deviation of the entire image can be reduced.

[0111] Figure 6 is a waveform diagram showing an example of the operation of the display device of Figure 1 , and Figure 7 is a graph for explaining the change of the reference voltage of Figure 6 .

[0112] In Figure 6 , only the scan signal supplied to the scan line is shown, and the control signal supplied to the control line is omitted for better understanding and ease of description.

[0113] Referring to Figure 2 to Figure 7 , the magnitude of the reference voltage Vint can change during one frame 1F with the first period P1 as one cycle.

[0114] According to some example embodiments, the reference voltage Vint during the first period P1 can gradually decrease. For example, the reference voltage Vint can linearly decrease during the first period P1. However, this is merely an example, and the form of decrease, the slope of decrease, etc. of the reference voltage Vint are not limited thereto.

[0115] The first period P1 can be a period including the first scan period SP1 of each of the pixel rows included in each of the pixel blocks BL1, BL2, and BL3. For example, the period during which the scan signal is sequentially supplied to the first to eighth scan lines SL1 to SL8 of the first pixel block BL1 can be the first period P1. Similarly, each of the period during which the scan signal is sequentially supplied to the scan lines corresponding to the pixel rows of the second pixel block BL2 and the period during which the scan signal is sequentially supplied to the scan lines corresponding to the pixel rows of the third pixel block BL3 can be defined as the first period P1. Accordingly, the driving of the supply of the reference voltage Vint at a reduced level can be repeated during the first period P1 of the pixel blocks BL1, BL2, and BL3.

[0116] Meanwhile, in Figure 6 , the period between the first scan period SP1 and the second scan period SP2 can correspond to the actual light emission time (or display period DP) of the corresponding pixel row.

[0117] When the voltage of the second electrode of the first transistor Tl is reduced under the same data voltage condition, the drive current can be increased. Because the display luminance is proportional to the drive current of the first transistor Tl, the display luminance can be increased as the drive current is increased. Thus, when the magnitude of the reference voltage Vint supplied to the pixel unit 100 during the first period P1 is reduced, the display luminance of the first to eighth pixel rows PR1 to PR8 can be adjusted to similar levels for the same gray scale (and the same image data voltage).

[0118] According to some example embodiments, the display luminance for each pixel row can be calculated by the following [Equation 1].

[0119] [Equation 1]

[0120] L'(N) = (T(l) / T(N)) · L(N)

[0121] Here, L'(N) is the desired display luminance of the Nth pixel row of the pixel block, T(l) is the light emission time of the first pixel row of the pixel block, T(N) is the light emission time of the Nth pixel row of the pixel block, and L(N) is the actual display luminance of the Nth pixel row of the pixel block. At this time, when the pixel block includes k pixel rows, N can be a natural number of k or less. In addition, the actual display luminance can be determined by the image data voltage supplied to the Nth pixel row.

[0122] Thus, the desired display luminance can be determined according to the ratio of the light emission times.

[0123] In addition, when it is assumed that the desired display luminance is proportional to the drive current of the first transistor Tl and [Equation 1] is applied in the drain current formula of the transistor, the following [Equation 2] can be derived.

[0124] [Equation 2]

[0125] Vint(N) = VDATA - (T(l) / T(N)) 0.5 · (VDATA - Vint(l))

[0126] Here, Vint(N) is the reference voltage Vint corresponding to the Nth pixel row of the pixel block, VDATA is the image data voltage (e.g., a set or predetermined image data voltage), T(l) is the light emission time of the first pixel row of the pixel block, T(N) is the light emission time of the Nth pixel row of the pixel block, and Vint(l) is the reference voltage Vint corresponding to the first pixel row of the pixel block. At this time, Vint(l) and VDATA can be constants (e.g., set or predetermined constants).

[0127] For example, when a scan signal of the first scan period SP1 is supplied to the Nth pixel row, a reference voltage Vint having a size of Vint(N) can be supplied.

[0128] Accordingly, the power supply 500 (see Figure 1 ) can output a reference voltage Vint having a waveform such as Figure 6 , so that the reference voltage Vint can gradually decrease as the first scan period SP1 progresses. For example, as shown in Figure 7 , the reference voltage Vint can change between a first level V1 and a second level V2 in response to a scan time of a pixel row (i.e., the first scan period SP1).

[0129] Accordingly, a difference in display brightness between the first pixel row PR1 and the eighth pixel row PR8 can be reduced. In addition, a difference in display brightness between a last pixel row (e.g., the eighth pixel row PR8) of the first pixel block BL1 and a first pixel row (e.g., the ninth pixel row PR9) of the second pixel block BL2 can be minimized or can be reduced. Accordingly, in the display device 1000 (see Figure 1 ) to which the black image insertion driving is applied, a perceptible difference in brightness according to a difference in light emission time for each pixel row can be reduced or can be minimized, and display quality can be improved.

[0130] Figure 8 is a diagram illustrating an example of a setting of a power line supplying a reference voltage included in the display device of Figure 1 .

[0131] Referring to Figure 4 to Figure 8 , a power line PL supplying a reference voltage Vint can extend from one side of the pixel unit 100 (see Figure 1 ) in a first direction DR1, and can branch to each of the pixel rows PR1 to PR16.

[0132] For example, the power line PL extending in the first direction DR1 can branch in a second direction DR2.

[0133] According to some example embodiments, the power line PL can be patterned while being overlaid with the pixel unit 100 (see Figure 1 ). Accordingly, the power supply 500 (see Figure 1 ) can supply the reference voltage Vint to the power line PL in common.

[0134] Because the reference voltage Vint in the pixel PXij of Figure 2 is supplied to the corresponding pixel PXij only when the third transistor T3 is turned on, the reference voltage Vint can be transmitted to the entire pixel row through the power line PL.

[0135] Figure 9 is a diagram illustrating an example of a setting of power lines supplying reference voltages included in a display device of Figure 1 , and Figure 10 is a diagram illustrating an example of voltage levels of reference voltages supplied to power lines of Figure 9 .

[0136] Referring to Figure 4 to Figure 7 , Figure 9 and Figure 10 , the display device 1000 (see Figure 1 ) can include power lines PL1 to PL8 supplying reference voltages Vint of different magnitudes.

[0137] According to some example embodiments, the power lines PL1 to PL8 can be set to extend from at least one side of the pixel unit 100 (see Figure 1 ) in the first direction DR1. According to some example embodiments, the number of the power lines PL1 to PL8 can be determined to be the same as the number of pixel rows set for each pixel block. For example, when each of the first and second pixel blocks BL1 and BL2 includes eight pixel rows, the display device 1000 (see Figure 1 ) can include first to eighth power lines PL1 to PL8. Each of the first to eighth power lines PL1 to PL8 can branch in the second direction DR2 at a certain pixel row interval (e.g., a set or predetermined pixel row interval).

[0138] The first power line PL1 can be connected to the first and ninth pixel rows PR1 and PR9. In other words, the first power line PL1 can be connected to the first pixel rows of the pixel blocks BL1 and BL2.

[0139] The second power line PL2 can be connected to the second and tenth pixel rows PR2 and PR10. In other words, the second power line PL2 can be connected to the second pixel rows of the pixel blocks BL1 and BL2.

[0140] Similarly, the third to eighth power lines PL3 to PL8 can be connected to the third and eleventh to last pixel rows PR3 and PR11 to PR8 and PR16 of the pixel blocks BL1 and BL2, respectively.

[0141] Meanwhile, as illustrated in Figure 10 , voltage levels of the reference voltages Vint supplied to each of the first to eighth power lines PL1 to PL8 can be different from each other. For example, a voltage of a first level V1 can be supplied to the first power line PL1, and a voltage of a second level V2 can be supplied to the eighth power line PL8. Different voltage levels between the first and second levels V1 and V2 can be supplied to the second to seventh power lines PL2 to PL7.

[0142] As described above, because a constant voltage is supplied to each pixel row, there is no need to change the reference voltage Vint in real time. Accordingly, the reference voltage Vint can be stably supplied to each pixel row PR1 to PR16.

[0143] Figure 11 is a waveform diagram showing an example of the operation of the display apparatus of Figure 1 , and Figure 12 is a graph specifically showing the change of the image data voltage of Figure 11 .

[0144] In Figure 11 , only a scan signal supplied to a scan line is shown for better understanding and ease of description, and a control signal supplied to a control line is omitted.

[0145] Referring to Figure 3 , Figure 4 , Figure 11 and Figure 12 , the magnitude of the image data voltage VDATA corresponding to the same gray scale can be changed with the first period P1 as one cycle.

[0146] Hereinafter, the image data voltage VDATA can be a voltage value corresponding to a first gray scale G1 of image data. The first gray scale G1 can be any gray scale selected from among gray scales applied to the display apparatus.

[0147] According to some example embodiments, the image data voltage VDATA can gradually increase during the first period P1. For example, the image data voltage VDATA can linearly increase during the first period P1. However, this is merely an example, and the form of increase, the slope of increase, etc. of the image data voltage VDATA are not limited thereto.

[0148] The first period P1 can be a period including the first scan period SP1 of each of the pixel rows included in each of the pixel blocks BL1, BL2, and BL3.

[0149] When the gate voltage of the first transistor T1 is increased under the same gray scale condition, the driving current can be increased. Because the display brightness is proportional to the driving current of the first transistor T1, the display brightness can be increased as the driving current increases. Accordingly, when the image data voltage VDATA is increased for the same gray scale during the first period P1, the display brightness of the first to eighth pixel rows PR1 to PR8 can be adjusted to a similar level even though the light emission time is reduced.

[0150] For example, when [Equation 1] is applied to a drain current formula of a transistor, the magnitude of the image data voltage VDATA supplied to a corresponding pixel row of a corresponding gray scale can be derived by the following [Equation 3].

[0151] [Equation 3]

[0152] VDATA(N) = (T(1) / T(N)) 0.5 ·(VDATA(1)-Vint)+Vint

[0153] Here, VDATA(N) is an image data voltage VDATA of the first gray scale G1 corresponding to the Nth pixel row of the pixel block, Vint is a reference voltage (for example, a set or predetermined reference voltage), T(1) is an emission time of the first pixel row of the pixel block, T(N) is an emission time of the Nth pixel row of the pixel block, and VDATA(1) is an image data voltage VDATA of the first gray scale G1 corresponding to the first pixel row of the pixel block.

[0154] For example, when a scan signal of the first scan period SP1 is supplied to the Nth pixel row, an image data voltage VDATA having a size of VDATA(N) can be supplied.

[0155] Accordingly, the data driver 300 (see Figure 1 ) can output an image data voltage VDATA having a waveform such as Figure 11 , so that the image data voltage VDATA of the first gray scale G1 can gradually increase as the first scan period SP1 progresses. For example, as shown in Figure 12 , the image data voltage VDATA can change between the third level V3 and the fourth level V4 in response to the scan time of the pixel row (i.e., the first scan period SP1).

[0156] Accordingly, the difference in display brightness between the first to eighth pixel rows PR1 to PR8 can be reduced. In addition, the difference in display brightness between the last pixel row (for example, the eighth pixel row PR8) of the first pixel block BL1 and the first pixel row (for example, the ninth pixel row PR9) of the second pixel block BL2 can be minimized or can be reduced. Accordingly, in the display device 1000 (see Figure 1 ) to which the black image insertion driving is applied, the perceptible difference in brightness according to the difference in emission time for each pixel row can be reduced or minimized, and the display quality can be improved.

[0157] Meanwhile, the reference voltage Vint can change together with the change in the image data voltage VDATA. For example, during the first period P1, the reference voltage Vint can gradually decrease.

[0158] Figure 13 is a block diagram showing an example of a partial configuration of the display device of Figure 1 .

[0159] Referring toFigure 1 、 Figure 11 and Figure 13 The display apparatus 1000 can further include a gamma voltage generator 700.

[0160] According to some example embodiments, the power supply 500' can further generate gamma tap voltages VGMA1 to VGMA9 (or gamma reference voltages) supplied to the gamma voltage generator 700. For example, the power supply 500' can determine the sizes of the first gamma tap voltage VGMA1 to the ninth gamma tap voltage VGMA9 based on the control signal CON supplied from the timing controller 600. That is, the voltage levels of the gamma tap voltages VGMA1 to VGMA9 can be changed for reference Figure 11 and Figure 12 adjustment of the image data voltage VDATA described above.

[0161] For example, the first gamma tap voltage VGMA1 can be a gamma voltage (or image data voltage VDATA) corresponding to a white gray scale, and the ninth gamma tap voltage VGMA9 can be a gamma voltage (or image data voltage VDATA) corresponding to a black gray scale.

[0162] According to some example embodiments, the control signal CON can include a command to change the size (or voltage level) of at least one of the first gamma tap voltage VGMA1 to the ninth gamma tap voltage VGMA9 for each write period (e.g., the first scan period SP1) of each pixel row. Accordingly, the power supply 500' can adjust the voltage levels of the first gamma tap voltage VGMA1 to the ninth gamma tap voltage VGMA9 in real time in units of pixel rows.

[0163] For example, the first gamma tap voltage VGMA1 to the ninth gamma tap voltage VGMA9 can be selected from a register or a memory in which values set according to the order of the pixel rows for each pixel block are stored in the corresponding pixel row. However, this is merely an example, and the method in which the first gamma tap voltage VGMA1 to the ninth gamma tap voltage VGMA9 are determined or output from the power supply 500' is not limited thereto.

[0164] The gamma voltage generator 700 can generate a gamma voltage GV (i.e., an image data voltage VDATA) corresponding to the entire gray scale of the display apparatus 1000 based on the first gamma tap voltage VGMA1 to the ninth gamma tap voltage VGMA9. The gamma voltage GV can be supplied to the data driver 300. For example, the gamma voltage GV can include voltage values (e.g., GV0 to GV255) corresponding to each of 256 gray scales.

[0165] According to some example embodiments, the gamma voltage generator 700 can include a resistor string that divides the first gamma tap voltage VGMA1 to the ninth gamma tap voltage VGMA9. For example, the gamma voltage GV can be determined based on the first gamma tap voltage VGMA1 to the ninth gamma tap voltage VGMA9 and a gamma curve (e.g., a set or predetermined gamma curve) (e.g., a 2.2 gamma curve, etc.).

[0166] Figure 14 is a diagram illustrating an example in which the gamma tap voltages are set in the pixel rows.

[0167] Referring to Figure 4 , Figure 13 and Figure 14 , the gamma tap voltages can be determined as different values according to the pixel rows of the pixel blocks.

[0168] For example, the first gamma tap voltage VGMA1 to the ninth gamma tap voltage VGMA9 corresponding to the first pixel rows PR1, PR9, …, PR(8k+1) of the pixel blocks can be determined through a voltage range between a first high voltage VH1 and a low voltage VL.

[0169] The first gamma tap voltage VGMA1' to the eighth gamma tap voltage VGMA8' corresponding to the last pixel rows PR8, PR16, …, PR(8k+8) of each of the pixel blocks can be determined through a voltage range between a second high voltage VH2 and the low voltage VL. Here, the second high voltage VH2 can be less than the first high voltage VH1.

[0170] Accordingly, the first gamma tap voltage VGMA1' to the eighth gamma tap voltage VGMA8' corresponding to the last pixel rows PR8, PR16, …, PR(8k+8) of the pixel blocks can have voltage values less than the first gamma tap voltage VGMA1 to the eighth gamma tap voltage VGMA8 corresponding to the first pixel rows PR1, PR9, …, PR(8k+1) of the pixel blocks, respectively. For example, a function connecting the gamma tap voltages corresponding to each of the pixel rows can be expressed as a straight line of a first order function, and a slope of the straight line can decrease from the first pixel row of each of the pixel blocks to the last pixel row of each of the pixel blocks.

[0171] In addition, the function of the gamma tap voltages corresponding to each of the second pixel rows PR2 to the seventh pixel rows PR7 can be formed to have different slopes between two straight lines as illustrated in Figure 14

[0172] In Figure 14 ​In the middle, the low voltage VL is shown as constant, but is not limited thereto. For example, a ninth gamma tap voltage corresponding to the last pixel row PR8, PR16, …, PR(8k+8) of the pixel block can be greater than a ninth gamma tap voltage VGMA9 corresponding to the first pixel row PR1, PR9, …, PR(8k+1) of the pixel block.

[0173] As described above, the gamma tap voltages VGMA1 to VGMA9 corresponding to each of the pixel rows of the pixel block can vary, such that the gamma voltage GV supplied to the data driver 300 can vary in real time in the pixel rows.

[0174] Figure 15 is a diagram showing an example of a configuration for setting Figure 14 the gamma tap voltages.

[0175] Except that the function of the power supply 500' of Figure 13 is replaced by the gamma tap voltage generator 800, Figure 15 the configuration of Figure 13 can have a similar configuration to that of

[0176] Referring to Figure 1 , Figure 11 , Figure 13 , Figure 14 and Figure 15 , the display apparatus 1000 can further include the gamma tap voltage generator 800 and the gamma voltage generator 700.

[0177] The gamma tap voltage generator 800 can adjust the gamma tap voltages VGMA1 to VGMA9 as the pixel rows included in each of the pixel blocks BL1, BL2, and BL3 are sequentially selected.

[0178] According to some example embodiments, the gamma tap voltage generator 800 can include a plurality of digital variable resistors DVR1 to DVR9 (or digital potentiometers) that generate the gamma tap voltages VGMA1 to VGMA9 by dividing a reference voltage AVDD and a ground voltage GND. The digital variable resistors DVR1 to DVR9 can be formed by programming resistance values corresponding to conditions or commands (e.g., set or predetermined conditions or commands). For example, when a pixel block includes eight pixel rows, eight resistance values corresponding to each of the pixel rows can be programmed in each of the digital variable resistors DVR1 to DVR9.

[0179] The resistance values of the digital variable resistors DVR1 to DVR9 can be changed based on the first control signal CON1 and the second control signal CON2 supplied from the timing controller 600. For example, the first control signal CON1 and the second control signal CON2 can include a signal determining a change timing of the resistance values, a signal including information on the changed resistance values, etc.

[0180] The gamma tap voltages VGMA1 to VGMA9 can include values such as Figure 14 , in the pixel row.

[0181] According to some example embodiments, the gamma tap voltage generator 800 can change the gamma tap voltages VGMA1 to VGMA9 by changing the reference voltage AVDD. Accordingly, the gamma tap voltages VGMA1 to VGMA9 corresponding to each of the pixel rows can be output by using a simple algorithm and a circuit configuration.

[0182] Figure 16 is a diagram illustrating an example of a setting of a drive power line supplying a voltage of a first driving power source included in a display apparatus of Figure 1 , and Figure 17 is a diagram illustrating an example of an operation of a display apparatus including a drive power line of Figure 16 .

[0183] Referring to Figure 2 , Figure 5 , Figure 16 and Figure 17 , the voltage of the first driving power source VDD can be changed with a first period P1 as one cycle.

[0184] According to some example embodiments, as the voltage of the first driving power source VDD for the same image data voltage VDATA increases, the driving current can increase. The power source 500 (see Figure 1 ) can output the voltage of the first driving power source VDD in a waveform as illustrated in Figure 17 .

[0185] Meanwhile, the first driving power source VDD can be supplied to all pixels simultaneously (or concurrently). In order to spatially separate the voltage levels of the first driving power source VDD, the display apparatus 1000 (see Figure 1 ) can include high potential drive power lines VDDL1 to VDDL8 supplying voltages of the first driving power source VDD of different sizes.

[0186] The high potential drive power lines VDDL1 to VDDL8 can be disposed to be along a first direction DR1 from the pixel unit 100 (see Figure 1extends at least one side of each of the pixel blocks BL1 and BL2. According to some example embodiments, when each of the pixel blocks BL1 and BL2 includes eight pixel rows, the display apparatus 1000 (see Figure 1 ) can include first to eighth high-potential driving power lines VDDL1 to VDDL8. Each of the first to eighth high-potential driving power lines VDDL1 to VDDL8 can branch off in the second direction DR2 at a certain pixel row interval (e.g., a set or predetermined pixel row interval).

[0187] The first high-potential driving power line VDDL1 can be connected to the first pixel row PR1 and the ninth pixel row PR9. In other words, the first high-potential driving power line VDDL1 can be connected to the first pixel rows of the pixel blocks BL1 and BL2.

[0188] The second high-potential driving power line VDDL2 can be connected to the second pixel row PR2 and the tenth pixel row PR10. In other words, the second high-potential driving power line VDDL2 can be connected to the second pixel rows of the pixel blocks BL1 and BL2.

[0189] Similarly, the third to eighth high-potential driving power lines VDDL3 to VDDL8 can be connected to the third pixel rows PR3 and PR11 to the last pixel rows PR8 and PR16 of the pixel blocks BL1 and BL2, respectively.

[0190] As described above, the difference in display brightness between the pixel rows PR1 to PR16 can be minimized or reduced by supplying different sizes of the voltage of the first driving power source VDD for each pixel row of the pixel blocks BL1 and BL2.

[0191] Figure 18 is a graph illustrating an example of the setting of the driving power line supplying the voltage of the second driving power source included in the display apparatus of Figure 1 , and Figure 19 is a graph illustrating an example of the operation of the display apparatus including the driving power line of Figure 18 .

[0192] Referring to Figure 2 , Figure 5 , Figure 18 and Figure 19 , the voltage of the second driving power source VSS can be changed with the first period P1 as one cycle.

[0193] According to some example embodiments, as the voltage of the second driving power source VSS for the same image data voltage VDATA decreases, the driving current can increase. The power source 500 (see Figure 1 ) can output the voltage of the second driving power source VSS in a waveform as illustrated in Figure 19 .

[0194] Meanwhile, the second driving power source VSS can be supplied to all the pixels simultaneously or concurrently. In order to spatially separate the voltage level of the second driving power source VSS, the display apparatus 1000 (see Figure 1 ) can include low potential driving power lines VSSL1 to VSSL8 that supply voltages of the second driving power source VSS of different magnitudes.

[0195] The low potential driving power lines VSSL1 to VSSL8 can be disposed to extend from at least one side of the pixel unit 100 (see Figure 1 ) in the first direction DR1. According to some example embodiments, when each of the pixel blocks BL1 and BL2 includes eight pixel rows, the display apparatus 1000 (see Figure 1 ) can include a first low potential driving power line VSSL1 to an eighth low potential driving power line VSSL8. Each of the first low potential driving power line VSSL1 to the eighth low potential driving power line VSSL8 can branch in the second direction DR2 at a certain pixel row interval (e.g., a set or predetermined pixel row interval).

[0196] As shown in Figure 18 , a difference in display brightness between the pixel rows PR1 to PR16 can be minimized or reduced by supplying voltages of the second driving power source VSS of different magnitudes for each of the pixel rows in the pixel blocks BL1 and BL2.

[0197] Figure 20 is a block diagram illustrating a display apparatus according to some example embodiments of the present application.

[0198] In Figure 20 , the same reference numerals are used to refer to constituent elements described with Figure 1 , and a repeated description of these constituent elements will be omitted. In addition, the display apparatus 1001 of Figure 20 may have substantially the same or similar configuration as the display apparatus 1000 of Figure 1 except for the sensing circuit 400 and the lines to which the reference voltage Vint is supplied.

[0199] Referring to Figure 20 , the display apparatus 1001 can include the pixel unit 100, the scan driver 200, the data driver 300, the sensing circuit 400, the power supply 500, and the timing controller 600.

[0200] The timing controller 600 can also control the operation of the sensing circuit 400. For example, the timing controller 600 can control the timing for supplying the reference voltage Vint to the pixels PX through the sensing lines SSL1 to SSLm and / or the timing for sensing the current generated from the pixels PX through the sensing lines SSL1 to SSLm.

[0201] The sensing circuit 400 can generate a compensation value compensating for a characteristic value of the pixel PX based on a sensing value (or a sensing current) provided from the sensing lines SSL1 to SSLm. For example, the sensing circuit 400 can detect and compensate for a variation in threshold voltage and a variation in mobility of the driving transistor and a variation in characteristics of the light emitting element included in the pixel PX.

[0202] According to some example embodiments, during a sensing period, the sensing circuit 400 can supply a reference voltage (e.g., a set or predetermined reference voltage) Vint to the pixel PX through the sensing lines SSL1 to SSLm, and can receive a current or a voltage extracted from the pixel PX. The extracted current or voltage can correspond to a sensing value, and the sensing circuit 400 can detect a variation in characteristics of the driving transistor based on the sensing value. The sensing circuit 400 can calculate a compensation value compensating for the input image data based on the detected variation in characteristics. The compensation value can be provided to the timing controller 600 or the data driver 300.

[0203] During a display period, the sensing circuit 400 can supply a reference voltage (e.g., a set or predetermined reference voltage) Vint to the pixel unit 100 through the sensing lines SSL1 to SSLm. According to some example embodiments, the reference voltage Vint can be provided to the sensing circuit 400 from the power supply 500.

[0204] Figure 21 is a circuit diagram illustrating an example of a pixel included in a display apparatus of Figure 20 .

[0205] In Figure 21 , the same reference numerals are used to refer to constituent elements described in Figure 2 , and repetitive description of these constituent elements will be omitted. In addition, the pixel PXij' of Figure 21 may have substantially the same or similar configuration as the pixel PXij of Figure 2 .

[0206] Referring to Figure 21 , the pixel PXij' can include a light emitting element LD, a first transistor T1 (or a driving transistor), a second transistor T2, a third transistor T3, and a storage capacitor Cst.

[0207] The third transistor T3 can be connected between the sensing line SSLj and the second electrode (i.e., the second node N2) of the first transistor T1. The gate electrode of the third transistor T3 can be connected to the control line CLi. The third transistor T3 can be turned on when a control signal is supplied to the control line CLi to electrically connect the sensing line SSLj and the second node N2 (i.e., the second electrode of the first transistor T1).

[0208] The reference voltage Vint can be supplied to the second node N2 through the sensing line SSLj, or a sensed value generated from the second node N2 can be supplied to the sensing circuit 400 (see Figure 20 ).

[0209] However, this is merely an example, and various modifications can be made to the configuration of the pixel PXij' and the external compensation method.

[0210] As described above, the display apparatus to which the black image insertion driving according to some example embodiments of the present application is applied can change the reference voltage Vint supplied to the pixel PX according to the difference in the light emission time of the pixel rows. In addition, the display apparatus can change the image data voltage VDATA corresponding to the same gray scale according to the difference in the light emission time of the pixel rows. Accordingly, the difference in the display brightness between the pixel rows adjacent to each other can be reduced.

[0211] Specifically, the difference in the display brightness between the last pixel row of the first pixel block and the first pixel row of the second pixel block adjacent to the first pixel block can be minimized or reduced. Accordingly, in the display apparatus to which the black image insertion driving is applied, the perceptible difference in brightness according to the difference in the light emission time for each pixel row (i.e., the perception of the boundary) is reduced or minimized, and the display quality can be improved.

[0212] While aspects of some example embodiments of the present application have been described with reference to the drawings, it is understood that various changes in form and details can be made therein without departing from the spirit and scope of embodiments according to the present application as defined by the following claims and their equivalents.

Claims

1. A display device, the display device comprising: Multiple pixel blocks, each comprising multiple pixels connected to scan lines, control lines, and data lines; A scan driver is configured to supply scan signals to the scan lines and control signals to the control lines; A data driver is configured to supply image data voltage or low grayscale data voltage to the data line; as well as The power supply is configured to supply a reference voltage to the plurality of pixels. The plurality of pixels are configured to receive the image data voltage during a first scan period of the frame and the low grayscale data voltage during a second scan period of the frame. Wherein, the reference voltage supplied to the first pixel row of at least one pixel block among the plurality of pixel blocks during the first scanning period is different from the reference voltage supplied to the last pixel row of at least one pixel block among the plurality of pixel blocks during the first scanning period. The power supply is configured to supply a reference voltage to the first pixel row during the first scan period that is greater than the reference voltage supplied to the last pixel row during the first scan period. The power supply is configured to gradually decrease the reference voltage as the first scan period progresses.

2. The display device according to claim 1, wherein, The low grayscale data voltage is the image data voltage corresponding to the black grayscale.

3. The display device according to claim 1, wherein, The first scan period, for the pixel row in the first pixel block included in the plurality of pixel blocks, is sequentially activated during the first scan period, and The second scan period for the pixel row included in the first pixel block is activated simultaneously at the same time.

4. The display device according to claim 3, wherein, The power supply is configured to change the reference voltage for each of the plurality of pixel blocks during the first time period.

5. The display device according to claim 2, wherein, Each of the plurality of pixel blocks comprises k consecutive rows of pixels, where k is an integer greater than 1.

6. The display device according to claim 5, further comprising: The first power line to the kth power line are respectively connected to the first pixel row to the kth pixel row of each of the plurality of pixel blocks, and are configured to transmit reference voltages of different voltage levels from the power supply.

7. The display device according to claim 6, wherein, The j-th power line is connected to the j-th pixel row of each of the plurality of pixel blocks, where j is an integer greater than or equal to 1 and less than or equal to k.

8. The display device according to claim 2, wherein, The scan driver is configured to sequentially supply the scan signal to the scan lines included in the p-th pixel block during a first time period, where p is a positive integer, and The scan driver is configured to simultaneously supply the scan signal to the scan lines included in the q-th pixel block within the first time period, where q is a positive integer different from p.

9. The display device according to claim 2, wherein, Each of the plurality of pixels includes: Light-emitting elements; A first transistor is connected between a first driving power supply and the light-emitting element, and has a gate electrode connected to a first node; The second transistor is connected between one of the data lines and the first node, and has a gate electrode for receiving the scan signal; A third transistor is configured to supply a reference voltage to a second node in response to a control signal supplied to the gate electrode of the third transistor; the first transistor and the light-emitting element are connected to the second node; and A storage capacitor is connected between the first node and the light-emitting element.

10. The display device according to claim 9, wherein, The second transistor and the third transistor are configured to be turned on during the first scan period, and The second transistor is configured to be turned on during the second scan period.

11. The display device according to claim 1, wherein, The data driver is configured to supply a first image data voltage corresponding to a first grayscale to the first pixel row of each of the plurality of pixel blocks and the last pixel row of each of the plurality of pixel blocks at different voltage levels.

12. The display device according to claim 11, wherein, The first image data voltage supplied to the first pixel row of each of the plurality of pixel blocks is less than the first image data voltage supplied to the last pixel row of each of the plurality of pixel blocks.

13. The display device according to claim 12, wherein, The data driver gradually increases the first image data voltage from the first pixel row of each of the plurality of pixel blocks to the last pixel row of each of the plurality of pixel blocks.

14. The display device according to claim 11, further comprising: A gamma tap voltage generator is configured to control the output gamma tap voltage in the pixel row of each of the plurality of pixel blocks. as well as A gamma voltage generator is configured to generate a gamma voltage corresponding to the pixel row based on the gamma tap voltage.

15. A display device, the display device comprising: Multiple pixel blocks, each comprising multiple pixels connected to scan lines, control lines, data lines, and sensing lines; A scan driver is configured to supply scan signals to the scan lines and control signals to the control lines; A data driver is configured to supply image data voltage or low grayscale data voltage to the data line; and The power supply is configured to supply a reference voltage to the plurality of pixels through the sensing lines. Each of the plurality of pixels is configured to receive the image data voltage during a first scan period of the frame and the low grayscale data voltage during a second scan period of the frame. The image data voltage supplied to the first pixel row of at least one of the plurality of pixel blocks is less than the image data voltage supplied to the last pixel row of at least one of the plurality of pixel blocks, and The image data voltage supplied to the first pixel row and the image data voltage supplied to the last pixel row both correspond to the first gray level. The image data voltage of the first grayscale level gradually increases as the first scanning period progresses.

16. The display device according to claim 15, wherein, The data driver is configured to progressively increase the image data voltage of the first grayscale level from the first pixel row of each of the plurality of pixel blocks to the last pixel row of each of the plurality of pixel blocks, and The low grayscale data voltage is the image data voltage corresponding to black grayscale.

17. The display device according to claim 16, further comprising: A gamma tap voltage generator is configured to decrease the gamma tap voltage as pixel rows included in each of the plurality of pixel blocks are selected sequentially. as well as A gamma voltage generator is configured to generate a gamma voltage corresponding to the pixel row based on the gamma tap voltage.

18. The display device according to claim 16, wherein, The power supply is configured to decrease the reference voltage as the pixel rows included in each of the plurality of pixel blocks are selected sequentially.

19. The display device according to claim 15, wherein, The emission time of the first pixel row of each of the plurality of pixel blocks is longer than the emission time of the last pixel row of each of the plurality of pixel blocks.

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