Display device

Abstract

A display device capable of improving image quality, the display device comprising: a display panel; a pixel located on the display panel and comprising at least one light-emitting element; a timing controller configured to receive an image data signal of the pixel and compensate the grayscale value of the image data signal based on the number of light-emitting elements of the pixel to generate a compensated image data signal; and a data driver configured to select a compensation data signal corresponding to the compensated image data signal from the timing controller and apply the compensation data signal to the pixel.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2018-0042599 filed on April 12, 2018 in the Korean Intellectual Property Office (KIPO), the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] Aspects of some example embodiments of the present invention relate to a display device, and, for example, to a display device capable of improving image quality. Background Art

[0004] Light emitting diodes ("LEDs") have relatively high light conversion efficiency, very low energy consumption, are semi-permanent and environmentally friendly. Therefore, LEDs are used in many fields, such as traffic lights, mobile phones, car headlights, outdoor electronic billboards, backlights, and indoor / outdoor lights.

[0005] Recently, display devices using nano-sized LEDs as light emitting elements have been studied.

[0006] Nano-LEDs are usually deposited on a substrate by an ink printing method, however, in this case, it is difficult to deposit the same number of nano-LEDs in each pixel. Therefore, the number of LEDs deposited in each pixel becomes different, and thus the driving current applied to each LED in each pixel may be different, so that the image quality may be deteriorated.

[0007] It should be understood that this technical background section is intended to provide a useful context for understanding the technology and as disclosed herein, the background technology section may include ideas, concepts or cognitions that were not known or understood by a person skilled in the relevant art before the corresponding effective filing date of the subject matter disclosed herein. Summary of the invention

[0008] Aspects of some example embodiments of the present invention may include a display device capable of improving image quality.

[0009] According to some example embodiments, a display device includes: a display panel; pixels located on the display panel, the pixels including at least one light emitting element; a timing controller configured to receive an image data signal of the pixel and compensate a grayscale value of the image data signal based on the number of light emitting elements of the pixel to generate a compensated image data signal; and a data driver configured to select a compensation data signal corresponding to the compensated image data signal from the timing controller and apply the compensation data signal to the pixel.

[0010] As the number of light emitting elements of a pixel becomes smaller, the compensated image data signal may have a smaller grayscale value.

[0011] The timing controller may compare the number of light emitting elements of the pixel with a predetermined reference value and generate a compensated image data signal based on the comparison result.

[0012] When the number of light emitting elements of a pixel is less than a reference value, the compensated image data signal may have a grayscale value smaller than a grayscale value of the image data signal.

[0013] As the difference between the number of light emitting elements of a pixel and the reference value becomes larger, the compensated image data signal may have a smaller grayscale value.

[0014] When the number of light emitting elements of a pixel is greater than a reference value, the compensated image data signal may have a grayscale value greater than a grayscale value of the image data signal.

[0015] As the difference between the number of light emitting elements of a pixel and the reference value becomes larger, the compensated image data signal may have a larger grayscale value.

[0016] The display device may further include a lookup table storing the number of light emitting elements of the pixel.

[0017] At least one of the light emitting elements may be a nano light emitting element.

[0018] The compensation data signal from the data driver may be applied to the pixel through the data line of the display panel.

[0019] The pixel may include: a first switching element, including a gate electrode connected to a gate line of a display panel, the first switching element being connected between a data line and a node; a second switching element, including a gate electrode connected to a node, the second switching element being connected between a first driving power line of the display panel and a first electrode of a light-emitting element; and a capacitor connected between the node and the first driving power line.

[0020] The second electrode of the light emitting element may be connected to a second driving power line of the display panel.

[0021] According to some example embodiments, a display device includes: a display panel including pixels connected to a first driving power line, a second driving power line, a data line, and a first compensation line; and a driving circuit configured to generate a first compensation voltage based on the number of light-emitting elements of the pixel and apply the first compensation voltage to the first compensation line. The pixel includes: a driving switching element receiving a data signal from the data line; at least one light-emitting element connected to the driving switching element; and a first compensation switching element including a gate electrode connected to the first compensation line, the first compensation switching element being connected between the first driving power line and the driving switching element.

[0022] As the number of light emitting elements of a pixel becomes smaller, the first compensation voltage may have a smaller value.

[0023] The driving circuit may compare the number of light emitting elements of the pixel with a predetermined reference value and generate a first compensation voltage based on the comparison result.

[0024] When the number of light emitting elements of the pixel is less than a reference value, the first compensation voltage may have a value smaller than a value of a predetermined reference compensation voltage.

[0025] As the difference between the number of light emitting elements of a pixel and the reference value becomes larger, the first compensation voltage may have a smaller value.

[0026] When the number of light emitting elements of the pixel is greater than a reference value, the first compensation voltage may have a value greater than a value of a predetermined reference compensation voltage.

[0027] According to some example embodiments, a display device includes: a display panel including pixels connected to a first driving power line, a second driving power line, a data line, and a first compensation line; and a driving circuit configured to generate a first compensation voltage based on the number of light emitting elements of the pixel and apply the first compensation voltage to the first compensation line. The pixel includes: a driving switching element receiving a data signal from the data line; at least one light emitting element connected to the driving switching element; and a first compensation switching element including a gate electrode connected to the first compensation line, the first compensation switching element being connected between the light emitting element and the second driving power line.

[0028] As the number of light emitting elements of a pixel becomes smaller, the first compensation voltage may have a smaller value.

[0029] The foregoing is illustrative only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become more apparent by reference to the drawings and the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] A more complete understanding of the present invention will become more apparent by describing in more detail aspects of some example embodiments of the present invention with reference to the accompanying drawings, in which:

[0031] Figure 1 are views showing display devices according to some example embodiments of the present invention;

[0032] Figure 2 yes Figure 1 A circuit diagram of one of the pixels shown in FIG.

[0033] Figure 3 It is shown Figure 1 The plan view of three adjacent pixels in ;

[0034] Figure 4 is along Figure 3 Sectional view taken along the midline I-I';

[0035] Figure 5 It is shown Figure 3 Detail of one of the light emitting diodes ("LEDs") in FIG.

[0036] FIG. 6A to FIG. 6E is a view for explaining the magnitude of a compensation data signal according to the number of LEDs included in a pixel;

[0037] Figure 7 is a view for explaining color distortion of light according to the number of LEDs of green pixels;

[0038] Figure 8 are views showing display devices according to some example embodiments of the present invention;

[0039] Fig. 9 Some example embodiments of the present invention are shown in Figure 8 Circuit diagram of a pixel in ;

[0040] Fig.10 Some example embodiments of the present invention are shown in Figure 8 Circuit diagram of a pixel in ;

[0041] Fig.11 Some example embodiments of the present invention are shown in Figure 8 Circuit diagram of a pixel in ;

[0042] Fig.12 Some example embodiments of the present invention are shown in Figure 8 A circuit diagram of a pixel in ; and

[0043] Fig.13 Some example embodiments of the present invention are shown in Figure 8 Circuit diagram of a pixel in . DETAILED DESCRIPTION

[0044] Aspects of some example embodiments will now be described more fully below with reference to the accompanying drawings. Although the present invention can be modified in various ways and has several embodiments, some embodiments are shown in the drawings and will be primarily described in the specification. However, the scope of the present invention is not limited to these embodiments, and should be interpreted as including all variations, equivalents and substitutions included in the spirit and scope of the present invention.

[0045] In the accompanying drawings, for clarity and ease of description, the thickness of multiple layers and regions is shown in an enlarged manner. When a layer, region or plate is referred to as being "on" another layer, region or plate, the layer, region or plate may be directly on another layer, region or plate, or there may be an intermediate layer, region or plate between them. On the contrary, when a layer, region or plate is referred to as being "directly" "on" another layer, region or plate, there may not be an intermediate layer, region or plate between them. In addition, when a layer, region or plate is referred to as being "under" another layer, region or plate, the layer, region or plate may be directly under another layer, region or plate, or there may be an intermediate layer, region or plate between them. On the contrary, when a layer, region or plate is referred to as being "directly" "under" another layer, region or plate, there may not be an intermediate layer, region or plate between them.

[0046] For ease of description, spatially relative terms "below," "below," "down," "above," "upper," etc. may be used herein to describe the relationship between one element or component and another element or component as shown in the drawings. It should be understood that in addition to the orientation depicted in the drawings, spatially relative terms are intended to include different orientations of the device in use or operation. For example, in the case where the device shown in the drawings is flipped, a device located "below" or "below" another device can be placed "above" the other device. Therefore, the illustrative term "below" can include both lower and upper positions. The device can also be oriented in another direction, and therefore spatially relative terms can be interpreted differently depending on the orientation.

[0047] Throughout the specification, when an element is referred to as being "connected" to another element, the element is "directly connected" to the other element, or "electrically connected" to the other element, with one or more intermediate elements interposed therebetween. It should also be understood that when the terms "comprises," "comprising," "includes," and / or "comprising" are used in this specification, they indicate the presence of stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or clusters thereof.

[0048] It should be understood that although the terms "first", "second", "third", etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. Thus, the "first element" discussed below may be referred to as the "second element" or the "third element", and without departing from the teachings herein, the "second element" and the "third element" may be named similarly.

[0049] As used herein, "about" or "approximately" includes the values ​​and means within the acceptable variation range of a particular value determined by one of ordinary skill in the art taking into account the relevant measurements and the errors associated with the measurement of a particular quantity (i.e., the limitations of the measurement system). For example, "about" can mean within one or more standard variations, or within ±30%, ±20%, ±10%, ±5% of the stated value.

[0050] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. It should also be understood that, unless explicitly defined in this specification, terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense.

[0051] Throughout the specification, the same reference numerals refer to the same elements.

[0052] In the following, reference will be made to Figures 1 to 13 Display devices according to some example embodiments of the present invention are described.

[0053] Figure 1 are views illustrating display devices according to some example embodiments of the present invention.

[0054] like Figure 1 As shown, the display device according to some example embodiments of the present invention includes a display panel 111 , a scan driver 151 , a data driver 153 , a timing controller 122 , a lookup table LUT, and a power supply 123 .

[0055] The display panel 111 includes a plurality of pixels PX and a plurality of scan lines SL1 to SLi for transmitting various signals required for the pixels PX to display images, a plurality of data lines DL1 to DLj, and power lines VL, where "i" is a natural number greater than 2 and "j" is a natural number greater than 3. The power lines VL include a first driving power line VDL and a second driving power line VSL that are electrically isolated from each other.

[0056] The pixels PX are arranged in a matrix form at the display panel 111 .

[0057] Each pixel PX includes at least one light emitting diode ("LED").

[0058] At least two pixels among all pixels (eg, "i*j" number of pixels) may include different numbers of LEDs. For example, if one pixel includes five LEDs, the other pixel may include one LED.

[0059] The pixels PX include a red pixel for displaying red, a green pixel for displaying green, and a blue pixel for displaying blue.

[0060] The red pixel includes at least one red LED that emits red light, the green pixel includes at least one green LED that emits green light, and the blue pixel includes at least one blue LED that emits blue light. In an example embodiment, a pixel does not necessarily include at least one LED. For example, each of the red pixel, the green pixel, and the blue pixel may include a red LED and a blue LED. In such an example embodiment, the red pixel, the green pixel, and the blue pixel may also include a color conversion layer located on the LED.

[0061] In the lookup table LUT, information about the number of LEDs included in each pixel PX is pre-stored. For example, information about the number of LEDs included in each of the "i*j" number of pixels PX may be pre-stored in the lookup table LUT.

[0062] Information about the number of LEDs of each pixel PX may be obtained, for example, through a photo taken by a camera or a current detected from each pixel PX of the display panel 111. The greater the number of LEDs of a pixel PX, the higher the current detected from the pixel PX.

[0063] The system located outside the display panel 111 outputs a vertical synchronization signal Vsync, a horizontal synchronization signal Hsync, a clock signal DCLK, a power signal VCC, and an image data signal DATA via an interface circuit by using a low voltage differential signal (LVDS) transmitter of a graphic controller. The vertical synchronization signal Vsync, the horizontal synchronization signal Hsync, the clock signal DCLK, and the power signal VCC output from the system are applied to the timing controller 122. In addition, the image data signal DATA sequentially output from the system is applied to the timing controller 122.

[0064] The timing controller 122 compensates each image data signal DATA of the pixel PX applied from the system to generate a compensated image data signal DATA', and applies the compensated image data signal DATA' to the data driver 153. In some example embodiments, the timing controller 122 may compensate the image data signal of the corresponding pixel based on the number of LEDs included in the corresponding pixel. For example, the timing controller 122 may identify the number of LEDs of the corresponding pixel based on information provided from the lookup table LUT, and compensate the image data signal of the corresponding pixel based on the number of LEDs.

[0065] The timing controller 122 generates a data control signal DCS and a scan control signal SCS based on the horizontal synchronization signal Hsync, the vertical synchronization signal Vsync, and the clock signal DCLK input to the timing controller 122, and outputs the data control signal DCS and the scan control signal SCS to the data driver 153 and the scan driver 151, respectively. The data control signal DCS is applied to the data driver 153, and the scan control signal SCS is applied to the scan driver 151.

[0066] The data control signal DCS includes a dot clock, a source shift clock, a source enable signal, and a polarity inversion signal.

[0067] The scan control signal SCS includes a gate start pulse, a gate shift clock, and a gate output enable signal.

[0068] The data driver 153 samples the compensated image data signal DATA' according to the data control signal DCS from the timing controller 122, latches the sampled image data signal corresponding to one horizontal line at each horizontal time (1H, 2H, ...), and applies the latched image data signal to the data lines DL1 to DLj. For example, the data driver 153 converts the compensated image data signal DATA' applied from the timing controller 122 into an analog signal using a gamma voltage input from the power supply 123, and applies the analog signal to the data lines DL1 to DLj.

[0069] The scan driver 151 includes a shift register and a level shifter, the shift register generates a scan signal in response to a gate start pulse in the scan control signal SCS applied from the timing controller 122, and the level shifter shifts the scan signal to a voltage level suitable for driving the pixel PX. The scan driver 151 applies the first scan signal to the i-th scan signal to the scan lines SL1 to SLi, respectively, in response to the scan control signal SCS applied from the timing controller 122.

[0070] The power supply 123 generates a plurality of gamma voltages, a first driving voltage VDD, and a second driving voltage VSS. The power supply 123 applies the plurality of gamma voltages to the data driver 153, applies the first driving voltage VDD to the first driving power line VDL, and applies the second driving voltage VSS to the second driving power line VSL.

[0071] Figure 2 It is shown Figure 1 Circuit diagram of one of the pixels in .

[0072] like Figure 2 As shown, the pixel PX includes a pixel circuit 180 and an LED that receives a driving current from the pixel circuit 180 .

[0073] The pixel circuit 180 may include a first switching element Tr1 , a second switching element Tr2 , and a storage capacitor Cst.

[0074] The first switching element Tr1 includes a first gate electrode connected to the nth scan line SLn, and is connected between the mth data line DLm and the node N. One of the first drain electrode and the first source electrode of the first switching element Tr1 is connected to the mth data line DLm, and the other of the first drain electrode and the first source electrode of the first switching element Tr1 is connected to the node N. For example, the first source electrode of the first switching element Tr1 is connected to the mth data line DLm, and the first drain electrode of the first switching element Tr1 is connected to the node N, where m is a natural number.

[0075] The second switching element Tr2 includes a second gate electrode connected to the node N, and is connected between the first driving power line VDL and the LED. One of the second drain electrode and the second source electrode of the second switching element Tr2 is connected to the first driving power line VDL, and the other of the second drain electrode and the second source electrode of the second switching element Tr2 is connected to the LED. For example, the second source electrode of the second switching element Tr2 is connected to the first driving power line VDL, and the second drain electrode of the second switching element Tr2 is connected to the LED.

[0076] The second switching element Tr2 is a driving switching element for driving the LED, and adjusts the amount (density) of driving current applied from the first driving power line VDL to the second driving power line VSL according to the amplitude of the data signal applied to the second gate electrode of the second switching element Tr2.

[0077] The storage capacitor Cst is connected between the node N and the first driving power line VDL. The storage capacitor Cst stores a signal applied to the second gate electrode of the second switching element Tr2 for one frame period.

[0078] The LED is connected between the second drain electrode of the second switching element Tr2 and the second driving power line VSL. The LED emits light according to the driving current applied through the second switching element Tr2. The LED emits light of different brightness depending on the magnitude of the driving current.

[0079] Figure 3 It is shown Figure 1 The plan view of three adjacent pixels in , and Figure 4 is along Figure 3 A cross-sectional view taken along line II' in FIG.

[0080] like Figure 3 and Figure 4As shown, the display device includes a substrate 301 , a buffer layer 302 , a first gate insulating layer 303 a , a second gate insulating layer 303 b , an insulating interlayer 304 , a planarization layer 305 , a first switching element Tr1 , a second switching element Tr2 , and a dummy layer 320 .

[0081] The first switching element Tr1 includes a first semiconductor layer 321 , a first gate electrode GE1 , a first source electrode SE1 , and a first drain electrode DE1 .

[0082] The second switching element Tr2 includes a second semiconductor layer 322 , a second gate electrode GE2 , a second source electrode SE2 , and a second drain electrode DE2 .

[0083] The buffer layer 302 is located on the substrate 301. The buffer layer 302 overlaps the entire surface of the substrate 301.

[0084] The first semiconductor layer 321 , the second semiconductor layer 322 , and the dummy layer 320 are located on the buffer layer 302 .

[0085] The first gate insulating layer 303a is located on the first semiconductor layer 321, the second semiconductor layer 322, and the buffer layer 302. The first gate insulating layer 303a overlaps the entire surface of the substrate 301.

[0086] The first gate electrode GE1, the second gate electrode GE2, and the second driving power line VSL are located on the first gate insulating layer 303a. In such an example embodiment, the first gate electrode GE1 is located on the first gate insulating layer 303a to overlap with the channel region C1 of the first semiconductor layer 321, the second gate electrode GE2 is located on the first gate insulating layer 303a to overlap with the channel region C2 of the second semiconductor layer 322, and the second driving power line VSL is located on the first gate insulating layer 303a to overlap with the dummy layer 320.

[0087] The second gate insulating layer 303 b is located on the first gate electrode GE1 , the second gate electrode GE2 , the second driving power line VSL, and the first gate insulating layer 303 a . The second gate insulating layer 303 b overlaps the entire surface of the substrate 301 .

[0088] The first driving power line VDL is located on the second gate insulating layer 303b. The first driving power line VDL is located on the second gate insulating layer 303b to overlap with the second gate electrode GE2. The storage capacitor Cst is located between the first driving power line VDL and the second gate electrode GE2.

[0089] The insulating interlayer 304 is located on the first driving power line VDL and the second gate insulating layer 303 b . The insulating interlayer 304 overlaps the entire surface of the substrate 301 .

[0090] The first source electrode SE1 , the first drain electrode DE1 , the second source electrode SE2 , the second drain electrode DE2 , and the connection electrode 340 are located on the insulating interlayer 304 .

[0091] The first source electrode SE1 is connected to the first source region S1 of the first semiconductor layer 321 through a first source contact hole, wherein the first source contact hole is defined by the insulating interlayer 304 , the second gate insulating layer 303 b , and the first gate insulating layer 303 a .

[0092] The first drain electrode DE1 is connected to the first drain region D1 of the first semiconductor layer 321 through a first drain contact hole, wherein the first drain contact hole is defined by the insulating interlayer 304, the second gate insulating layer 303b, and the first gate insulating layer 303a. The first drain electrode DE1 is connected to the second gate electrode GE2 through a contact hole, wherein the contact hole is defined by the insulating interlayer 304 and the second gate insulating layer 303b.

[0093] The second source electrode SE2 is connected to the second source region S2 of the second semiconductor layer 322 through a second source contact hole, wherein the second source contact hole is defined by the insulating interlayer 304, the second gate insulating layer 303b, and the first gate insulating layer 303a. The second source electrode SE2 is connected to the first driving power line VDL through a contact hole, wherein the contact hole is defined by the insulating interlayer 304.

[0094] The second drain electrode DE2 is connected to the second drain region D2 of the second semiconductor layer 322 through a second drain contact hole defined by the insulating interlayer 304 , the second gate insulating layer 303 b , and the first gate insulating layer 303 a .

[0095] The connection electrode 340 is connected to the second driving power line VSL through a contact hole defined by the insulating interlayer 304 and the second gate insulating layer 303 b .

[0096] The planarization layer 305 is located on the first source electrode SE1 , the first drain electrode DE1 , the second source electrode SE2 , the second drain electrode DE2 , the connection electrode 340 , and the insulating interlayer 304 .

[0097] The first electrode unit 351 and the second electrode unit 352 are located on the planarization layer 305 .

[0098] The first electrode unit 351 is connected to the second drain electrode DE2 through a first contact hole, wherein the first contact hole is defined by the planarization layer 305 .

[0099] The second electrode unit 352 is connected to the connection electrode 340 through a second contact hole, wherein the second contact hole is defined by the planarization layer 305. The second electrode unit 352 is connected to the second driving power line VSL through the connection electrode 340.

[0100] The LED is located on the first electrode unit 351, the second electrode unit 352, and the planarization layer 305. For example, the first electrode of the LED is located on the first electrode unit 351, and the second electrode of the LED is located on the second electrode unit 352. The first electrode of the LED is connected to the first electrode unit 351, and the second electrode of the LED is connected to the second electrode unit 352.

[0101] The first pixel PX1, the second pixel PX2, and the third pixel PX3 may include LEDs that emit light of different colors, respectively. For example, the LED of the first pixel PX1 may be a red LED that emits red light, the LED of the second pixel PX2 may be a green LED that emits green light, and the LED of the third pixel PX3 may be a blue LED that emits blue light.

[0102] like Figure 3 As shown, the first pixel PX1, the second pixel PX2, and the third pixel PX3 may include different numbers of LEDs, respectively. For example, the first pixel PX1 may include five LEDs, the second pixel PX2 may include four LEDs, and the third pixel PX3 may include one LED.

[0103] The first contact electrode 371 is located on the first electrode unit 351 and the first electrode of the LED. The first contact electrode 371 is connected to the first electrode unit 351 and the first electrode of the LED.

[0104] The second contact electrode 372 is located on the second electrode unit 352 and the second electrode of the LED. The second contact electrode 372 is connected to the second electrode unit 352 and the second electrode of the LED.

[0105] The light shielding layer 306 is located on the planarization layer 305. The light shielding layer 306 has an opening 355 that defines a pixel region. The aforementioned LED is located in the pixel region.

[0106] The spacer 307 is located on the light shielding layer 306. The width of the spacer 307 is smaller than the width of the light shielding layer 306, and the thickness of the spacer 307 is greater than the thickness of the light shielding layer 306. The width of the spacer 307 and the width of the light shielding layer 306 refer to the dimensions in the X-axis direction, and the thickness of the spacer 307 and the thickness of the light shielding layer 306 refer to the dimensions in the Z-axis direction.

[0107] The protection layer 308 is located on the light shielding layer 306 , the LED, the first electrode unit 351 , the second electrode unit 352 , the first contact electrode 371 , the second contact electrode 372 , and the planarization layer 305 .

[0108] The anti-reflection layer 309 is located on the protective layer 308 and the spacer 307. The anti-reflection layer 309 prevents (or substantially prevents) reflection of light incident from the outside to the display device.

[0109] The first pixel PX1, the second pixel PX2, and the third pixel PX3 may include anti-reflection layers 309 of different colors. For example, the anti-reflection layer 309 of the first pixel PX1 may be a red anti-reflection layer that prevents (or reduces) red light reflection, the anti-reflection layer 309 of the second pixel PX2 may be a green anti-reflection layer that prevents (or reduces) green light reflection, and the anti-reflection layer 309 of the third pixel PX3 may be a blue anti-reflection layer that prevents (or reduces) blue light reflection.

[0110] The encapsulation layer 310 is located on the anti-reflection layer 309 and the spacer 307. The encapsulation layer 310 overlaps the entire surface of the substrate 301.

[0111] Figure 5 It is shown Figure 3 Detail of one of the LEDs in the image.

[0112] LEDs are light-emitting elements with a length of, for example, nanometers or micrometers. LEDs can have Figure 5 Although not shown, the LED may have a quadrilateral parallelepiped shape or various other shapes.

[0113] The LED may include a first electrode 411, a second electrode 412, a first semiconductor layer 431, a second semiconductor layer 432, and an active layer 450. In example embodiments, the LED may further include an insulating layer 470 in addition to the above-described components 411, 412, 431, 432, and 450. At least one of the first electrode 411 and the second electrode 412 may be omitted.

[0114] The first semiconductor layer 431 is located between the first electrode 411 and the active layer 450 .

[0115] The active layer 450 is located between the first semiconductor layer 431 and the second semiconductor layer 432 .

[0116] The second semiconductor layer 432 is located between the active layer 450 and the second electrode 412 .

[0117] The insulating layer 470 may have a ring shape surrounding a portion of the first electrode 411, a portion of the second electrode 412, the first semiconductor layer 431, the active layer 450, and the second semiconductor layer 432. As another example, the insulating layer 470 may have a ring shape surrounding only the active layer 450. The insulating layer 470 prevents (or substantially prevents) contact between the active layer 450 and the first electrode unit 351 and contact between the active layer 450 and the second electrode unit 352. In addition, the insulating layer 470 may prevent (or substantially prevent) the light emitting efficiency of the LED from being deteriorated by protecting the outer surface including the active layer 450.

[0118] The first electrode 411, the first semiconductor layer 431, the active layer 450, the second semiconductor layer 432, and the second electrode 412 are sequentially stacked along the longitudinal direction of the LED. As used herein, the length of the LED refers to the dimension in the X-axis direction. For example, the length L of the LED may be in the range of about 2 μm to about 5 μm.

[0119] The first electrode 411 and the second electrode 412 may be ohmic contact electrodes, however, the first electrode 411 and the second electrode 412 are not limited thereto and may be Schottky contact electrodes.

[0120] The first electrode 411 and the second electrode 412 may include a conductive metal. For example, the first electrode 411 and the second electrode 412 may include one or more metal materials of aluminum, titanium, indium, gold, and silver. In addition, the first electrode 411 and the second electrode 412 may include indium tin oxide (ITO) or indium zinc oxide (IZO). The first electrode 411 and the second electrode 412 may include substantially the same material. Alternatively, the first electrode 411 and the second electrode 412 may include materials different from each other.

[0121] The first semiconductor layer 431 may include, for example, an n-type semiconductor layer. As an example, when the LED is a blue LED, the n-type semiconductor layer may include an In x Al y Ga 1-x-y A semiconductor material having a composition formula of N, wherein 0≤x≤1, 0≤y≤1, and 0≤x+y≤1, for example, one or more of InAlGaN, GaN, AlGaN, InGaN, AlN, InN, etc. The n-type semiconductor material may be doped with a first conductive dopant (e.g., Si, Ge, Sn, etc.).

[0122] An LED having a different color other than the above-mentioned blue LED may include another III-V semiconductor material as the n-type semiconductor layer.

[0123] The first electrode 411 may be omitted. When the first electrode 411 is not present, the first semiconductor layer 431 may be connected to the first electrode unit 351 .

[0124] The second semiconductor layer 432 may include, for example, a p-type semiconductor layer. As an example, when the LED is a blue LED, the p-type semiconductor layer may include an In x Al y Ga 1-x-y The semiconductor material of the composition formula of N, wherein 0≤x≤1, 0≤y≤1, and 0≤x+y≤1, for example, one or more of InAlGaN, GaN, AlGaN, InGaN, AlN, InN, etc. The p-type semiconductor layer may be doped with a second conductive dopant (eg, Mg).

[0125] The second electrode 412 may be omitted. When the second electrode 412 is not present, the second semiconductor layer 432 may be connected to the second electrode unit 352 .

[0126] The active layer 450 may have a single or multiple quantum well structure. For example, a capping layer doped with a conductive dopant may be located at least one of the upper side and the lower side of the active layer 450. The capping layer (i.e., the capping layer including the conductive dopant) may be an AlGaN layer or an InAlGaN layer. In addition, materials such as AlGaN or AlInGaN may be used as the active layer 450. When an electric field is applied to the active layer 450, light is generated by coupling of electron-hole pairs. Depending on the type of LED, the position of the active layer 450 may be changed differently.

[0127] The active layer of an LED having a different color than the above-mentioned blue LED may include another III-V semiconductor material.

[0128] The LED may further include at least one of a phosphor layer, an active layer, a semiconductor layer, and electrodes above or below the first semiconductor layer 431 and the second semiconductor layer 432 .

[0129] like Figure 3As shown, when the first pixel PX1, the second pixel PX2, and the third pixel PX3 include different numbers of LEDs, respectively, the magnitudes of the driving currents applied to the LED of the first pixel PX1 (hereinafter referred to as the "first LED"), the LED of the second pixel PX2 (hereinafter referred to as the "second LED"), and the LED of the third pixel PX3 (hereinafter referred to as the "third LED") become different with respect to substantially the same data voltage (e.g., the data voltage corresponding to the image data signal). That is, the driving current applied to the smallest number of the third LED has the highest level compared to the other driving currents. In other words, when the driving current is divided to be applied to a plurality of LEDs, the divided current may be defined as a unit driving current, and the unit driving current applied to the third LED is the largest.

[0130] In the case where the first LED, the second LED, and the third LED are all green LEDs that emit green light, the third LED receiving the maximum driving current may emit blue light instead of green light. For example, when a data signal corresponding to an image data signal of the highest grayscale level (e.g., grayscale level 255) (hereinafter referred to as "the data signal of the highest grayscale level") is applied to the third pixel PX3, the third LED may emit blue light by a large driving current generated by the data signal of the highest grayscale level.

[0131] In some example embodiments, since the driving current generated by the data signal of the highest gray level is divided and applied to the five first LEDs in the first pixel PX1, the unit driving current applied to each of the five first LEDs is relatively small. Therefore, each first LED can normally emit green light.

[0132] In some example embodiments, since the driving current generated by the data signal of the highest grayscale level is divided and applied to the four second LEDs in the second pixel PX2, the unit driving current applied to each of the four second LEDs is relatively large. Therefore, the second LED can emit light closer to blue than the first LED.

[0133] Even when the first LED, the second LED, and the third LED described above are all red LEDs that emit red light, the second LED and the third LED may emit light of a different color other than red due to the different amplitudes of the driving current described above.

[0134] Similarly, even when the first LED, the second LED, and the third LED described above are all blue LEDs that emit blue light, due to the different amplitudes of the driving current described above, the second LED and the third LED may emit light of a different color other than blue.

[0135] The timing controller 122 according to some example embodiments of the present invention may prevent (or substantially prevent) image quality degradation due to the above color distortion by compensating the image data signal of the pixel PX based on the number of LEDs included in the pixel PX, which will be referred to as FIG. 6A to FIG. 6E Describe in more detail.

[0136] FIG. 6A to FIG. 6E is a view for explaining the magnitude of a compensation data signal according to the number of LEDs included in a pixel, and Figure 7 is a view for explaining color distortion of light according to the number of LEDs of green pixels.

[0137] refer to FIG. 6A to FIG. 6C , the image data signal may have an amplitude corresponding to one of a plurality of predetermined gray levels. For example, the image data signal may have an amplitude corresponding to one of 256 gray levels. In other words, the image data signal may have an amplitude corresponding to one gray level in a range from gray level 0 (i.e., the lowest gray level) to gray level 255 (i.e., the highest gray level).

[0138] The image data signals from grayscale level 0 to grayscale level 255 are image data signals representing different brightness. For example, the image data signal of grayscale level 0 represents the image data signal of the darkest grayscale level (e.g., a full black grayscale level), and the image data signal of grayscale level 255 is the image data signal of the brightest grayscale level (e.g., a full white grayscale level). In other words, an image data signal of a relatively high grayscale level is a relatively bright image data signal.

[0139] exist FIG. 6A to FIG. 6E In FIG. 1 , the image data signal D_Gp represents an image data signal of gray level p, where p can be, for example, a gray level from gray level 0 to gray level 255. For example, Fig. 6A The image data signal D_G255 in φ represents an image data signal of grayscale level 255. When the number of grayscale levels is greater than 256, the maximum value of p may be greater than 255.

[0140] The image data signal has different grayscale values ​​depending on the grayscale level. For example, the higher the grayscale level of the image data signal, the greater the grayscale value of the image data signal. Fig. 6A , the image data signal D_G255 of grayscale level 255 has a grayscale value greater than the grayscale value of the image data signal D_G254 of grayscale level 254.

[0141] Depending on the type of driving switching element, the voltage of the image data signal (ie, the digital voltage) may be gradually increased or gradually decreased in proportion to the grayscale value of the image data signal. Figure 2 As shown, when the second switching element Tr2 of the pixel is a P-type transistor, the greater the grayscale value of the image data signal, the lower the voltage of the image data signal. For example, when the second switching element Tr2 of the pixel described above is a P-type transistor, Fig. 6A The image data signal D_G255 of gray level 255 in the pixel may have a voltage lower than the voltage of the image data signal D_G254 of gray level 254. On the other hand, when the second switching element Tr2 of the pixel is an N-type transistor, the greater the gray value of the image data signal, the higher the voltage of the image data signal. For example, when the second switching element Tr2 of the pixel described above is an N-type transistor, Fig. 6A The image data signal D_G255 of the grayscale level 255 may have a voltage higher than a voltage of the image data signal D_G254 of the grayscale level 254.

[0142] exist FIG. 6A to FIG. 6D , D_q_Gp represents a compensated image data signal for an image data signal of gray level "p" including a "q" number of LEDs, where q is a natural number and may be one of k, k-1, k-2, k+1, and k+2 to be described below. For example, Fig. 6A The compensated image data signal D_k-1_G255 represents a compensated image data signal of the image data signal D_G255 of the grayscale level 255 for a pixel including a “k-1” number of LEDs.

[0143] The compensated image data signal has different grayscale values ​​depending on the grayscale level. For example, the higher the grayscale level of the compensated image data signal, the larger the grayscale value of the compensated image data signal. Fig. 6A , the compensated image data signal D_k-1_G255 of the grayscale level 255 has a grayscale value greater than the grayscale value of the compensated image data signal D_k-1_G254 of the grayscale level 254.

[0144] Depending on the type of driving switching element, the voltage of the compensated image data signal (ie, the digital voltage) may be gradually increased or gradually decreased in proportion to the grayscale value of the compensated image data signal. Figure 2 As shown, when the second switching element Tr2 of the pixel is a P-type transistor, the greater the grayscale value of the compensated image data signal, the lower the voltage of the compensated image data signal. For example, when the second switching element Tr2 of the pixel described above is a P-type transistor, Fig. 6A The compensated image data signal D_k-1_G255 of the gray level 255 may have a voltage lower than that of the compensated image data signal D_k-1_G254 of the gray level 254 .

[0145] On the other hand, when the second switching element Tr2 of the pixel described above is an N-type transistor, the greater the grayscale value of the compensated image data signal, the higher the voltage of the compensated image data signal. Fig. 6A The compensated image data signal D_k-1_G255 of the gray level 255 may have a voltage higher than that of the compensated image data signal D_k-1_G254 of the gray level 254 .

[0146] FIG. 6A to FIG. 6D The compensation data signal A_q_Gp in represents an analog voltage for the corresponding compensated image data signal. The image data signal and the compensated image data signal are digital signals, and the compensation data signal is an analog voltage corresponding to the compensated image data signal. In other words, the compensation data signal is an analog voltage predetermined according to the digital compensated image data signal. For example, Fig. 6A A_k-1_G255 in φ represents an analog voltage for the compensated image data signal D_k-1_G255.

[0147] exist FIG. 6A to FIG. 6D In the embodiment, the compensation data signal has different grayscale values ​​depending on the grayscale level. For example, the higher the grayscale level of the compensation data signal, the greater the grayscale value of the compensation data signal. Fig. 6A The compensation data signal A_k-1_G255 of the grayscale level 255 has a grayscale value greater than the grayscale value of the compensation data signal A_k-1_G254 of the grayscale level 254.

[0148] Depending on the type of driving switching element, the voltage of the compensation data signal (ie, the analog voltage) may be gradually increased or gradually decreased in proportion to the grayscale value of the compensation data signal. Figure 2 As shown, when the second switching element Tr2 of the pixel is a P-type transistor, the greater the grayscale value of the compensation data signal, the lower the voltage of the compensation data signal. For example, when the second switching element Tr2 of the pixel described above is a P-type transistor, Fig. 6A The compensation data signal A_k-1_G255 of the gray level 255 in the pixel may have a voltage lower than the voltage of the compensation data signal A_k-1_G254 of the gray level 254. On the other hand, when the second switching element Tr2 of the pixel is an N-type transistor, the greater the gray value of the compensation data signal, the higher the voltage of the compensation data signal. For example, when the second switching element Tr2 of the pixel described above is an N-type transistor, Fig. 6A The compensation data signal A_k-1_G255 of the gray level 255 may have a voltage higher than that of the compensation data signal A_k-1_G254 of the gray level 254.

[0149] Fig. 6E The data signal A_Gp in represents an analog voltage corresponding to the image data signal. For example, Fig. 6E A_G255 in FIG. 2 represents an analog voltage corresponding to the image data signal D_G255.

[0150] exist Fig. 6E In the embodiment, the data signal has different grayscale values ​​depending on the grayscale level. For example, the higher the grayscale level of the data signal, the greater the grayscale value of the data signal. Fig. 6E The data signal A_G255 of the grayscale level 255 has a grayscale value greater than the grayscale value of the data signal A_G254 of the grayscale level 254.

[0151] Depending on the type of driving switching element, the voltage of the data signal (ie, the analog voltage) may be gradually increased or gradually decreased in proportion to the grayscale value of the data signal. Figure 2 As shown, when the second switching element Tr2 of the pixel is a P-type transistor, the greater the grayscale value of the data signal, the lower the voltage of the data signal. For example, when the second switching element Tr2 of the pixel described above is a P-type transistor, Fig. 6E The data signal A_G255 of the grayscale level 255 in the pixel may have a voltage lower than the voltage of the data signal A_G254 of the grayscale level 254. On the other hand, when the second switching element Tr2 of the pixel is an N-type transistor, the greater the grayscale value of the data signal, the higher the voltage of the data signal. For example, when the second switching element Tr2 of the pixel described above is an N-type transistor, Fig. 6E The data signal A_G255 of the gray level 255 may have a voltage higher than the voltage of the data signal A_G25 of the gray level 254.

[0152] The timing controller 122 compensates the image data signal of the pixel PX provided from the system based on the number of LEDs included in the pixel PX.

[0153] For example, as the number of LEDs included in the pixel PX becomes smaller, the compensated image data signal of the pixel PX may have a smaller grayscale value.

[0154] For example, the timing controller 122 may compare a predetermined reference value “k” (see FIG. 6 ) with the number of LEDs of the pixel PX, and compensate the image data signal of the pixel PX based on the comparison result, where k is a natural number.

[0155] The reference value represents the number of LEDs included in a pixel when light of a normal expected color is emitted from the pixel. Figure 7As shown in FIG. 1 , when an image data signal of the highest grayscale level (e.g., grayscale level 255) is applied to a green pixel, and green light is generally generated by five green LEDs included in the green pixel, the reference value may be 5. In such an example embodiment, normal green light may have a color located at a green light coordinate (i.e., X=0.149 and Y=0.657) in the CIE chromaticity coordinate system. On the other hand, as the number of LEDs of the green pixel decreases from its reference value of 5, the light from the green pixel has a color closer to blue. For example, as Figure 7 As shown, when the number of LEDs of the green pixel is 1, the light may have a color located at a blue light coordinate (ie, X=0.129 and Y=0.287) in the CIE chromaticity coordinate system.

[0156] Figure 7 The CIE chromaticity coordinate system in includes a green area A1, a blue area A2 and a red area A3.

[0157] As a result of the above comparison, when it is determined that the number of LEDs of pixel PX is less than the reference value "k", the timing controller 122 can correct (or modulate) the image data signal of pixel PX into a compensated image data signal having a grayscale value smaller than the grayscale value of the image data signal of pixel PX.

[0158] For example, Fig. 6A As shown, when the pixel PX includes a "k-1" number of LEDs (which is less than the reference value "k") and the grayscale level of the image data signal D_G255 of the pixel PX is 255, the timing controller 122 can output D_k-1_G255 as the compensated image data signal of the pixel PX. The compensated image data signal D_k-1_G255 has a grayscale value smaller than the grayscale value of the image data signal D_G255. In other words, the image data signal D_G255 and the compensated image data signal D_k-1_G255 have the same grayscale level 255, but the grayscale value of D_G255 and the grayscale value of D_k-1_G255 are different from each other.

[0159] so, Fig. 6A The compensated image data signal in has a grayscale value smaller than the grayscale value of the image data signal corresponding thereto. In other words, the compensated image data signal has a grayscale value smaller than the grayscale value of the image data signal, wherein the image data signal has the same grayscale level as the grayscale level of the compensated image data signal.

[0160] The compensated image data signal output from the timing controller 122 is applied to the data driver 153. For example, the compensated image data signal D_k-1_G255 described above is applied to the data driver 153.

[0161] The data driver 153 outputs (e.g., selects and outputs) a compensation data signal corresponding to the compensated image data signal. For example, the data driver 153 outputs a compensation data signal A_k-1_G255 corresponding to the compensated image data signal D_k-1_G255. As used herein, the compensation data signal A_k-1_G255 represents an analog voltage corresponding to the compensated image data signal D_k-1_G255.

[0162] When the number of LEDs of the pixel PX is less than the reference value "k" described above, as the difference between the number of LEDs of the pixel PX and the reference value "k" becomes larger, the timing controller 122 outputs a compensated image data signal having a smaller grayscale value. Therefore, the larger the difference between the number of LEDs of the pixel PX and the reference value, the larger the difference in grayscale value between the image data signal and the compensated image data signal thereof.

[0163] For example, when Fig. 6A The pixel shown including "k-1" number of LEDs is defined as the first pixel and as Figure 6B When the pixel including the LEDs of the number "k-2" is defined as a second pixel, the compensated image data signal of the second pixel has a grayscale value smaller than the grayscale value of the compensated image data signal of the first pixel, although the compensated image data signal of the first pixel has the same grayscale level as the compensated image data signal of the second pixel. For example, Figure 6B The compensated image data signal D_k-2_G255 of gray level 255 has a ratio Fig. 6A The grayscale value of the compensated image data signal D_k-1_G255 at the grayscale level 255 is a small grayscale value.

[0164] Similarly, D_k-2_G0 has a grayscale value smaller than that of D_k-1_G0, D_k-2_G1 has a grayscale value smaller than that of D_k-1_G1, and D_k-2_G2 has a grayscale value smaller than that of D_k-1_G2, and D_k-2_G254 has a grayscale value smaller than that of D_k-1_G254.

[0165] Therefore, A_k-2_G0 has a grayscale value smaller than that of A_k-1_G0, A_k-2_G1 has a grayscale value smaller than that of A_k-1_G1, A_k-2_G2 has a grayscale value smaller than that of A_k-1_G2, and A_k-2_G254 has a grayscale value smaller than that of A_k-1_G254.

[0166] When the number of LEDs of the pixel PX is less than a predetermined reference value "k", the pixel PX receives a data signal (i.e., a compensated data signal) set based on an image data signal (i.e., a compensated image data signal), wherein the image data signal (i.e., the compensated image data signal) has a grayscale value smaller than the grayscale value of the original image data signal. Therefore, the pixel PX may generate a driving current having a level lower than the current level of the reference pixel. For example, the pixel circuit 180 of the pixel PX may generate a driving current having a level lower than the current level generated by the pixel circuit 180 of the reference pixel. As used herein, a reference pixel refers to a pixel including a number of LEDs corresponding to a reference value.

[0167] Therefore, the LED of the pixel PX and the LED of the reference pixel can receive substantially the same level of unit driving current, respectively. In other words, when the driving current is divided to be applied to a plurality of LEDs included in one pixel, the divided current can be defined as a unit driving current, and the unit driving current applied to each LED of the pixel PX and the unit driving current applied to each LED of the reference pixel can be substantially equal to each other. Therefore, although the pixel PX and the reference pixel include different numbers of LEDs, respectively, light (e.g., green light) of substantially the same color (e.g., color of the same coordinates on the chromaticity coordinate system) can be generated.

[0168] On the other hand, if the comparison result indicates that the number of LEDs of pixel PX is greater than the reference value "k", the timing controller 122 can correct (or modulate) the image data signal of pixel PX into a compensated image data signal having a grayscale value greater than the grayscale value of the image data signal of pixel PX.

[0169] For example, Figure 6C As shown, when the pixel PX includes a "k+1" number of LEDs (which is greater than the reference value "k") and the grayscale level of the image data signal D_G255 of the pixel PX is 255, the timing controller 122 can output D_k+1_G255 as the compensated image data signal of the pixel PX. The compensated image data signal D_k+1_G255 has a grayscale value greater than the grayscale value of the image data signal D_G255. In other words, the image data signal D_G255 and the compensated image data signal D_k+1_G255 have the same grayscale level 255, but the grayscale value of D_G255 and the grayscale value of D_k+1_G255 are different from each other.

[0170] so, Figure 6CThe compensated image data signal in has a grayscale value greater than the grayscale value of the image data signal corresponding thereto. In other words, the compensated image data signal has a grayscale value greater than the grayscale value of the image data signal, wherein the image data signal has the same grayscale level as the grayscale level of the compensated image data signal.

[0171] The compensated image data signal D_k+1_G255 output from the timing controller 122 is applied to the data driver 153. The data driver 153 outputs a compensation data signal A_k+1_G255 corresponding to the compensated image data signal D_k+1_G255. As used herein, the compensation data signal A_k+1_G255 represents an analog voltage corresponding to the compensated image data signal D_k+1_G255.

[0172] In addition, as described above, when the number of LEDs of the pixel PX is greater than the reference value "k" as described above, as the difference between the number of LEDs of the pixel PX and the reference value "k" becomes larger, the timing controller 122 outputs a compensated image data signal having a larger grayscale value. Therefore, the larger the difference between the number of LEDs of the pixel PX and the reference value, the larger the difference in grayscale value between the image data signal and the compensated image data signal thereof.

[0173] For example, when Figure 6C The pixel shown including "k+1" number of LEDs is defined as the first pixel and as Fig.6D When the pixel including the "k+2" number of LEDs shown is defined as a second pixel, the compensated image data signal of the second pixel has a grayscale value greater than the grayscale value of the compensated image data signal of the first pixel, wherein the compensated image data signal of the first pixel has the same grayscale level as the grayscale level of the compensated image data signal of the second pixel. For example, Fig.6D The compensated image data signal D_k+2_G255 of gray level 255 has a ratio Figure 6C The grayscale value of the compensated image data signal D_k+1_G255 at the grayscale level 255 is a larger grayscale value.

[0174] Similarly, D_k+2_G0 has a grayscale value greater than that of D_k+1_G0, D_k+2_G1 has a grayscale value greater than that of D_k+1_G1, and D_k+2_G2 has a grayscale value greater than that of D_k+1_G2, and D_k+2_G254 has a grayscale value greater than that of D_k+1_G254.

[0175] Therefore, A_k+2_G0 has a grayscale value greater than that of A_k+1_G0, A_k+2_G1 has a grayscale value greater than that of A_k+1_G1, A_k+2_G2 has a grayscale value greater than that of A_k+1_G2, and A_k+2_G254 has a grayscale value greater than that of A_k+1_G254.

[0176] In some example embodiments, FIG. 6A to FIG. 6E In the embodiment, the compensation data signals of the lowest gray level (or the data signals of the lowest gray level) may all have the same gray value. For example, A_k-1_G0, A_k-2_G0, A_k+1_G0, A_k+2_G0, and A_G0 may have the same gray value.

[0177] In this way, when the number of LEDs of the pixel PX is greater than the predetermined reference value "k", the pixel PX receives a data signal (i.e., a compensated data signal) set based on the image data signal (i.e., a compensated image data signal), wherein the image data signal (i.e., the compensated image data signal) has a grayscale value greater than the grayscale value of the original image data signal. Therefore, the pixel PX can generate a driving current having a level higher than the current level of the reference pixel. For example, the pixel circuit 180 of the pixel PX can generate a driving current having a level higher than the current level generated by the pixel circuit 180 of the reference pixel.

[0178] Therefore, the LED of the pixel PX and the LED of the reference pixel can receive substantially the same level of unit drive current, respectively. In other words, the unit drive current applied to each LED of the pixel PX and the unit drive current applied to each LED of the reference pixel can be substantially equal to each other. Therefore, although the pixel PX and the reference pixel include different numbers of LEDs, respectively, light (e.g., green light) of substantially the same color (e.g., color of the same coordinates on the chromaticity coordinate system) can be generated.

[0179] On the other hand, when the number of LEDs of the pixel PX is equal to the reference value “k”, the timing controller 122 may output the image data signal of the pixel substantially without correction.

[0180] For example, Fig. 6E As shown, when the pixel PX includes the same number of LEDs as the reference value “k” and the grayscale level of the image data signal D_G255 of the pixel PX is 255, for example, the timing controller 122 outputs the image data signal D_G255 as it is without correction.

[0181] The image data signal D_G255 output from the timing controller 122 is applied to the data driver 153. The data driver 153 outputs the data signal A_G255 corresponding to the image data signal D_G255. As used herein, the data signal A_G255 represents an analog voltage corresponding to the image data signal D_G255.

[0182] A_G0 has a grayscale value that is smaller than the grayscale value of A_k+1_G0 and larger than the grayscale value of A_k-1_G0, A_G1 has a grayscale value that is smaller than the grayscale value of A_k+1_G1 and larger than the grayscale value of A_k-1_G1, A_G254 has a grayscale value that is smaller than the grayscale value of A_k+1_G254 and larger than the grayscale value of A_k-1_G254, and A_G255 has a grayscale value that is smaller than the grayscale value of A_k+1_G255 and larger than the grayscale value of A_k-1_G255.

[0183] Figure 8 are views illustrating display devices according to some example embodiments of the present invention.

[0184] like Figure 8 As shown, a display device according to another embodiment of the present invention includes a display panel 111 , a scan driver 151 , a data driver 153 , a timing controller 122 , a lookup table LUT, and a power supply 123 .

[0185] Figure 8 The display panel 111 in FIG. 1 includes a plurality of pixels PX, a plurality of scan lines SL1 to SLi, a plurality of data lines DL1 to DLj, a first driving power line VDL, a second driving power line VSL, and a plurality of compensation lines CL.

[0186] Figure 8 The plurality of pixels PX, the plurality of scan lines SL1 to SLi, the plurality of data lines DL1 to DLj, the first driving power line VDL and the second driving power line VSL are respectively connected to Figure 2 The plurality of pixels PX, the plurality of scan lines SL1 to SLi, the plurality of data lines DL1 to DLj, the first driving power line VDL, and the second driving power line VSL are substantially the same.

[0187] A plurality of compensation lines CL are connected to the scan driver 151. In addition, the plurality of compensation lines CL are respectively connected to a plurality of pixels PX. For example, "i*j" number of compensation lines CL are respectively and individually connected to "i*j" number of pixels PX. In other words, "i*j" number of pixels PX are individually connected to different compensation lines CL.

[0188] Figure 8The timing controller 122 in FIG. 1 resets the image data signal DATA applied from the system and applies the reset image data signal DATA′ to the data driver 153 .

[0189] The timing controller 122 generates a data control signal DCS and a scan control signal SCS based on the horizontal synchronization signal Hsync, the vertical synchronization signal Vsync, and the clock signal DCLK input to the timing controller 122, and outputs the data control signal DCS and the scan control signal SCS to the data driver 153 and the scan driver 151, respectively. The data control signal DCS is applied to the data driver 153, and the scan control signal SCS is applied to the scan driver 151.

[0190] The data control signal DCS includes a dot clock, a source shift clock, a source enable signal, and a polarity inversion signal.

[0191] The scan control signal SCS includes a gate start pulse, a gate shift clock, and a gate output enable signal.

[0192] Figure 8 The data driver 153 in the data controller 122 samples the reset image data signal DATA' according to the data control signal DCS from the timing controller 122, latches the sampled image data signal corresponding to one horizontal line at each horizontal time (1H, 2H, ...), and applies the latched image data signal to the data lines DL1 to DLj. For example, the data driver 153 converts the reset image data signal DATA' applied from the timing controller 122 into an analog signal using a gamma voltage input from the power supply 123, and applies the analog signal to the data lines DL1 to DLj.

[0193] Figure 8 The scan driver 151 in the embodiment includes a shift register and a level shifter, the shift register generates a scan signal in response to a gate start pulse in a scan control signal SCS applied from the timing controller 122, and the level shifter shifts the scan signal to a voltage level suitable for driving the pixel PX. The scan driver 151 applies the first scan signal to the i-th scan signal to the scan lines SL1 to SLi, respectively, in response to the scan control signal SCS applied from the timing controller 122.

[0194] in addition, Figure 8 The scan driver 151 in FIG. 1 generates a compensation voltage for each pixel PX based on the number of LEDs of each pixel PX provided by the lookup table LUT, and applies the compensation voltage to the compensation line CL.

[0195] The compensation voltage is a DC voltage and may have different values ​​depending on the number of LEDs included in the pixel PX. For example, the smaller the number of LEDs included in the pixel PX, the lower the compensation voltage applied to the pixel PX.

[0196] Figure 8 The power supply 123 in the above description Figure 1 The power supply 123 in is the same (or substantially the same).

[0197] Fig. 9 is a diagram showing an embodiment according to the present invention Figure 8 Circuit diagram of a pixel in .

[0198] like Fig. 9 As shown, the pixel PX includes a pixel circuit 180 and an LED that receives a driving current from the pixel circuit 180 .

[0199] The pixel circuit 180 may include a first switching element Tr1 , a second switching element Tr2 , a compensation switching element Trc, and a storage capacitor Cst.

[0200] Fig. 9 The first switching element Tr1 in the above-described Figure 2 The first switching element Tr1 in is basically the same.

[0201] Fig. 9 The LEDs in the Figure 2 The LEDs in are basically the same.

[0202] The second switching element Tr2 includes a second gate electrode connected to the first node N1, and is connected between the second node N2 and the first electrode of the LED. One of the second drain electrode and the second source electrode of the second switching element Tr2 is connected to the second node N2, and the other of the second drain electrode and the second source electrode of the second switching element Tr2 is connected to the first electrode of the LED. For example, the second source electrode of the second switching element Tr2 is connected to the second node N2, and the second drain electrode of the second switching element Tr2 is connected to the first electrode of the LED.

[0203] The second switching element Tr2 adjusts the amount (density) of driving current applied from the first driving power line VDL to the second driving power line VSL according to the amplitude of the signal applied to the second gate electrode of the second switching element Tr2 .

[0204] Fig. 9The compensation switch element Trc in the embodiment includes a gate electrode connected to the compensation line CL, and is connected between the first driving power line VDL and the second node N2. One of the source electrode and the drain electrode of the compensation switch element Trc is connected to the first driving power line VDL, and the other of the source electrode and the drain electrode of the compensation switch element Trc is connected to the second node N2. For example, the source electrode of the compensation switch element Trc is connected to the first driving power line VDL, and the drain electrode of the compensation switch element Trc is connected to the second node N2.

[0205] The compensation switching element Trc adjusts the amount (density) of the driving current applied from the first driving power line VDL to the second switching element Tr2 according to the magnitude of the compensation voltage Vc applied to the gate electrode of the compensation switching element Trc.

[0206] The storage capacitor Cst is connected between the first node N1 and the second node N2. The storage capacitor Cst stores a signal applied to the second gate electrode of the second switching element Tr2 for one frame period.

[0207] The first electrode of the LED is connected to the second drain electrode of the second switching element Tr2, and the second electrode of the LED is connected to the second driving power line VSL. The LED emits light according to the driving current applied by the compensation switching element Trc and the second switching element Tr2. Depending on the amplitude of the driving current, the LED emits light of different brightness.

[0208] The above-described compensation voltage Vc is applied to the gate electrode of the compensation switching element Trc.

[0209] Depending on the type of the compensation switching element Trc, the compensation voltage Vc may have a positive amplitude or a negative amplitude. Fig. 9 As shown, when the compensation switch element Trc is a P-type transistor, the compensation voltage Vc has a negative amplitude. On the other hand, when the compensation switch element Trc is an N-type transistor, the compensation voltage Vc has a positive amplitude. Therefore, unless otherwise specified, the amplitude of the compensation voltage Vc represents the amplitude of the absolute value of the compensation voltage Vc. That is, the fewer the number of LEDs included in the pixel PX, the smaller the absolute value of the compensation voltage Vc applied to the pixel PX.

[0210] For example, in the case where the first pixel PX1, the second pixel PX2, and the third pixel PX3 all include LEDs of the same color (eg, a green LED), as shown in FIG. Figure 3As shown, when the second pixel PX2 includes fewer LEDs than the first pixel PX1, the compensation voltage Vc applied to the second pixel PX2 is lower than the compensation voltage Vc applied to the first pixel PX1. That is, the compensation voltage Vc applied to the gate electrode of the compensation switching element Trc included in the second pixel PX2 is lower than the compensation voltage Vc applied to the gate electrode of the compensation switching element Trc included in the first pixel PX1.

[0211] Therefore, the compensation switching element Trc of the second pixel PX2 is turned on at a level lower than that of the compensation switching element Trc of the first pixel PX1. In other words, the compensation switching element Trc of the second pixel PX2 has a resistance (e.g., an internal resistance of a transistor) greater than that of the compensation switching element Trc of the first pixel PX1. Therefore, the driving current applied to the LED of the second pixel PX2 through the compensation switching element Trc of the second pixel PX2 is less than the driving current applied to the LED of the first pixel PX1 through the compensation switching element Trc of the first pixel PX1.

[0212] As described above, the pixel circuit 180 of the second pixel PX2 including a relatively small number of LEDs generates a driving current at a level lower than the driving current level generated by the pixel circuit 180 of the first pixel PX1 including a relatively large number of LEDs. Therefore, the LED of the second pixel PX2 and the LED of the first pixel PX1 can receive substantially the same level of unit driving current, respectively. In other words, the unit driving current applied to each LED of the first pixel PX1 and the unit driving current applied to each LED of the second pixel PX2 can be substantially equal to each other. Therefore, although the first pixel PX1 and the second pixel PX2 respectively include different numbers of LEDs, light (e.g., green light) of substantially the same color (e.g., color of the same coordinates on the chromaticity coordinate system) can be generated.

[0213] In addition, since the third pixel PX3 includes fewer LEDs than the second pixel PX2 (the third pixel PX3 may be Figure 3 As shown in FIG. 1 , the compensation voltage Vc applied to the compensation switching element Trc of the third pixel PX3 is lower than the compensation voltage Vc applied to the compensation switching element Trc of the second pixel PX2. Therefore, although the first pixel PX1, the second pixel PX2, and the third pixel PX3 include different numbers of LEDs, they can generate light of substantially the same color.

[0214] When a pixel including a number of LEDs corresponding to the reference value "k" described above is defined as a reference pixel, and a compensation voltage Vc applied to the compensation switching element Trc of the reference pixel is defined as a reference compensation voltage, the scan driver 151 may apply a compensation voltage Vc having a value smaller than that of the reference compensation voltage to a pixel including a smaller number of LEDs than the reference value "k". In this case, when the number of LEDs of the pixel PX is less than the reference value "k", as the difference between the number of LEDs of the pixel PX and the reference value "k" becomes larger, the scan driver 151 applies a lower compensation voltage Vc to the pixel PX.

[0215] On the other hand, the scan driver 151 may apply a compensation voltage Vc having a value greater than that of the reference compensation voltage to a pixel including a greater number of LEDs than the reference value "k". In this case, when the number of LEDs of the pixel PX is greater than the reference value "k", as the difference between the number of LEDs of the pixel PX and the reference value "k" becomes larger, the scan driver 151 applies a higher compensation voltage Vc to the pixel PX.

[0216] Fig.10 Some example embodiments of the present invention are shown in Figure 8 Circuit diagram of a pixel in .

[0217] like Fig.10 As shown, the pixel PX includes a pixel circuit 180 and an LED that receives a driving current from the pixel circuit 180 .

[0218] The pixel circuit 180 may include a first switching element Tr1 , a second switching element Tr2 , a compensation switching element Trc, and a storage capacitor Cst.

[0219] Fig.10 The first switching element Tr1 in the above-described Figure 2 The first switching element Tr1 in is the same (or substantially the same).

[0220] Fig.10 The second switching element Tr2 in the above-described Figure 2 The same (or substantially the same) as the second switching element Tr2 in.

[0221] Fig.10 The storage capacitor Cst in the above-described Figure 2 The storage capacitor Cst in is the same (or substantially the same).

[0222] Fig.10The compensation switch element Trc in the embodiment includes a third gate electrode connected to the compensation line CL, and is connected between the second electrode of the LED and the second driving power line VSL. One of the source electrode and the drain electrode of the compensation switch element Trc is connected to the second electrode of the LED, and the other of the source electrode and the drain electrode of the compensation switch element Trc is connected to the second driving power line VSL. For example, the source electrode of the compensation switch element Trc is connected to the second electrode of the LED, and the drain electrode of the compensation switch element Trc is connected to the second driving power line VSL.

[0223] The compensation switching element Trc adjusts the amount (density) of the driving current applied from the LED to the second driving power line VSL according to the magnitude of the compensation voltage Vc applied to the gate electrode of the compensation switching element Trc.

[0224] exist Fig.10 In the embodiment, the first electrode of the LED is connected to the second drain electrode of the second switching element Tr2, and the second electrode of the LED is connected to the source electrode of the compensation switching element Trc.

[0225] The LED emits light according to the driving current applied through the compensation switching element Trc and the second switching element Tr2. Depending on the magnitude of the driving current, the LED emits light of different brightness.

[0226] The above-described compensation voltage Vc is applied to the gate electrode of the compensation switching element Trc.

[0227] Depending on the type of the compensation switching element Trc, the compensation voltage Vc may have a positive amplitude or a negative amplitude. Fig.10 As shown, when the compensation switch element Trc is a P-type transistor, the compensation voltage Vc has a negative amplitude. On the other hand, when the compensation switch element Trc is an N-type transistor, the compensation voltage Vc has a positive amplitude. Therefore, unless otherwise specified, the amplitude of the compensation voltage Vc represents the amplitude of the absolute value of the compensation voltage Vc. That is, the fewer the number of LEDs included in the pixel PX, the smaller the absolute value of the compensation voltage Vc applied to the pixel PX.

[0228] For example, in the case where the first pixel PX1, the second pixel PX2, and the third pixel PX3 all include LEDs of the same color (eg, a green LED), as shown in FIG. Figure 3 As shown, when the second pixel PX2 includes fewer LEDs than the first pixel PX1, the compensation voltage Vc applied to the second pixel PX2 is lower than the compensation voltage Vc applied to the first pixel PX1. That is, the compensation voltage Vc applied to the gate electrode of the compensation switching element Trc included in the second pixel PX2 is lower than the compensation voltage Vc applied to the gate electrode of the compensation switching element Trc included in the first pixel PX1.

[0229] Therefore, the compensation switching element Trc of the second pixel PX2 is turned on at a level lower than that of the compensation switching element Trc of the first pixel PX1. Fig. 9 As described, pixels including different numbers of LEDs can produce the same (or substantially the same) color of light.

[0230] Fig.11 FIG. 1 is a diagram showing another embodiment of the present invention. Figure 8 Circuit diagram of a pixel in .

[0231] like Fig.11 As shown, the pixel PX includes a pixel circuit 180 and an LED that receives a driving current from the pixel circuit 180 .

[0232] The pixel circuit 180 may include a first switching element Tr1, a second switching element Tr2, a first compensation switching element Trc1, a second compensation switching element Trc2, and a storage capacitor Cst.

[0233] Fig.11 The first switching element Tr1 in the above-described Figure 2 The first switching element Tr1 in is the same (or substantially the same).

[0234] Fig.11 The second switching element Tr2 in the above-described Fig. 9 The same (or substantially the same) as the second switching element Tr2 in.

[0235] Fig.11 The first compensation switch element Trc1 in the above-described Fig. 9 The compensation switching element Trc in is the same (or substantially the same).

[0236] Fig.11 The second compensation switch element Trc2 in the above-described Fig.10 The compensation switching element Trc in is the same (or substantially the same).

[0237] Fig.11 The LEDs in the Fig.10 The LEDs in are the same (or substantially the same).

[0238] The first compensation line CL1 connected to the first compensation switching element Trc1 is connected to the Fig. 9 The compensation lines CL in are the same (or substantially the same).

[0239] The second compensation line CL2 connected to the second compensation switch element Trc2 is connected to the Fig.10 The compensation lines CL in are the same (or substantially the same).

[0240] The first and second compensation switching elements Trc1 and Trc2 of each pixel PX are connected to the scan driver 151. For example, gate electrodes of the first and second compensation switching elements Trc1 and Trc2 included in each pixel PX are connected to the scan driver 151 individually.

[0241] The LED emits light according to the driving current controlled by the first compensation switching element Trc1, the second switching element Tr2 and the second compensation switching element Trc2. Depending on the magnitude of the driving current, the LED emits light of different brightness.

[0242] Depending on the type of the first compensation switch element Trc1, the first compensation voltage Vc1 may have a positive amplitude or a negative amplitude. Fig.11 As shown, when the first compensation switch element Trc1 is a P-type transistor, the first compensation voltage Vc1 has a negative amplitude. On the other hand, when the first compensation switch element Trc1 is an N-type transistor, the first compensation voltage Vc1 has a positive amplitude. Therefore, unless otherwise specified, the amplitude of the first compensation voltage Vc1 represents the amplitude of the absolute value of the first compensation voltage Vc1. That is, the smaller the number of LEDs included in the pixel PX, the smaller the absolute value of the first compensation voltage Vc1 applied to the pixel PX.

[0243] For example, in the case where the first pixel PX1, the second pixel PX2, and the third pixel PX3 all include LEDs of the same color (eg, a green LED), as shown in FIG. Figure 3 As shown, when the second pixel PX2 includes fewer LEDs than the first pixel PX1, the first compensation voltage Vc1 applied to the second pixel PX2 is lower than the first compensation voltage Vc1 applied to the first pixel PX1. That is, the first compensation voltage Vc1 applied to the gate electrode of the first compensation switching element Trc1 included in the second pixel PX2 is lower than the first compensation voltage Vc1 applied to the gate electrode of the first compensation switching element Trc1 included in the first pixel PX1.

[0244] Depending on the type of the second compensation switch element Trc2, the second compensation voltage Vc2 may have a positive amplitude or a negative amplitude. Fig.11 As shown, when the second compensation switch element Trc2 is a P-type transistor, the second compensation voltage Vc2 has a negative amplitude. On the other hand, when the second compensation switch element Trc2 is an N-type transistor, the second compensation voltage Vc2 has a positive amplitude. Therefore, unless otherwise specified, the amplitude of the second compensation voltage Vc2 represents the amplitude of the absolute value of the second compensation voltage Vc2. That is, the fewer the number of LEDs included in the pixel PX, the smaller the absolute value of the second compensation voltage Vc2 applied to the pixel PX.

[0245] For example, in the case where the first pixel PX1, the second pixel PX2, and the third pixel PX3 all include LEDs of the same color (eg, a green LED), as shown in FIG. Figure 3 As shown, when the second pixel PX2 includes fewer LEDs than the first pixel PX1, the second compensation voltage Vc2 applied to the second pixel PX2 is lower than the second compensation voltage Vc2 applied to the first pixel PX1. That is, the second compensation voltage Vc2 applied to the gate electrode of the second compensation switching element Trc2 included in the second pixel PX2 is lower than the second compensation voltage Vc2 applied to the gate electrode of the second compensation switching element Trc2 included in the first pixel PX1.

[0246] Fig.12 Some example embodiments of the present invention are shown in Figure 8 Circuit diagram of a pixel in .

[0247] like Fig.12 As shown, the pixel PX includes a pixel circuit 180 and an LED that receives a driving current from the pixel circuit 180 .

[0248] The pixel circuit 180 includes a first switching element Tr1, a second switching element Tr2, a third switching element Tr3, a fourth switching element Tr4, a fifth switching element Tr5, a sixth switching element Tr6, a seventh switching element Tr7, and a storage capacitor Cst.

[0249] Fig.12 The first switching element Tr1 in the embodiment includes a gate electrode connected to the first node N1, and is connected between the second node N2 and the third node N3. The first switching element Tr1 is a driving switching element for driving the LED, and the first switching element Tr1 adjusts the amount (density) of driving current applied from the first driving power line VDL to the second driving power line VSL according to the amplitude of the data signal applied to the gate electrode of the first switching element Tr1.

[0250] Fig.12 The second switching element Tr2 includes a gate electrode connected to the nth scan line SLn, and is connected between the mth data line DLm and the second node N2.

[0251] Fig.12 The third switching element Tr3 includes a gate electrode connected to the n-th scan line SLn, and is connected between the first node N1 and the third node N3.

[0252] Fig.12The fourth switching element Tr4 includes a gate electrode connected to the (n-1)th scan line SLn-1, and is connected between the first node N1 and the initialization line IL. An initialization voltage Vinit is applied to the initialization line IL.

[0253] Fig.12 The fifth switching element Tr5 includes a gate electrode connected to the nth emission control line ELn, and is connected between the fifth node N5 and the second node N2.

[0254] Fig.12 The sixth switching element Tr6 in FIG. 1 includes a gate electrode connected to the nth emission control line ELn, and is connected between the third node N3 and the fourth node N4. The nth emission control signal ESn is applied to the nth emission control line ELn.

[0255] Fig.12 The seventh switching element Tr7 includes a gate electrode connected to the (n+1)th scan line SLn+1, and is connected between the initialization line IL and the fourth node N4.

[0256] Fig.12 The first compensation switching element Trc1 includes a gate electrode connected to the first compensation line CL1, and is connected between the first driving power line VDL and a fifth node N5.

[0257] Fig.12 The second compensation switching element Trc2 in the embodiment includes a gate electrode connected to the second compensation line CL2, and is connected between the second electrode of the LED and the second driving power line VSL.

[0258] Fig.12 The storage capacitor Cst in is connected between the first driving power line VDL and the first node N1. The storage capacitor Cst stores a signal for one frame period applied to the gate electrode of the first switching element Tr1.

[0259] Fig.12 The LED in is connected between the fourth node N4 and the second compensation switch element Trc2. For example, a first electrode of the LED is connected to the fourth node N4, and a second electrode of the LED is connected to the source electrode of the second compensation switch element Trc2.

[0260] Fig.12 The first compensation switch element Trc1 and the second compensation switch element Trc2 are respectively connected to Fig.11 The first compensation switching element Trc1 and the second compensation switching element Trc2 are identical (or substantially identical) to each other.

[0261] In some example embodiments, from Fig.12The structure in which the first compensation switching element Trc1 and the second compensation switching element Trc2 are omitted can be applied to the above-described Figure 1 Pixels in .

[0262] Fig.13 Some example embodiments of the present invention are shown in Figure 8 Circuit diagram of a pixel in .

[0263] like Fig.13 As shown, the pixel PX includes a pixel circuit 180 and an LED that receives a driving current from the pixel circuit 180 .

[0264] The pixel circuit 180 includes first, second, third, fourth, fifth, and sixth switching elements Tr1, Tr2, Tr3, Tr4, Tr5, Tr6, first and second compensation switching elements Trc1, Trc2, and first and second storage capacitors Cst1 and Cst2.

[0265] Fig.13 The first switching element Tr1 in the embodiment includes a gate electrode connected to the first node N1, and is connected between the second node N2 and the third node N3. The first switching element Tr1 is a driving switching element for driving the LED, and the first switching element Tr1 adjusts the amount (density) of driving current applied from the first driving power line VDL to the second driving power line VSL according to the amplitude of the data signal applied to the gate electrode of the first switching element Tr1.

[0266] Fig.13 The second switching element Tr2 includes a gate electrode connected to the n-th scan line SLn, and is connected between the second node N2 and the first node N1.

[0267] Fig.13 The third switching element Tr3 includes a gate electrode connected to the nth scan line SLn, and is connected between the mth data line DLm and the third node N3.

[0268] Fig.13 The fourth switching element Tr4 includes a gate electrode connected to the (n-1)th scan line SLn-1, and is connected between the first node N1 and the initialization line IL. An initialization voltage Vinit is applied to the initialization line IL.

[0269] Fig.13 The fifth switching element Tr5 includes a gate electrode connected to the nth emission control line ELn, and is connected between the second node N2 and the fourth node N4. The nth emission control signal ESn is applied to the nth emission control line ELn.

[0270] Fig.13 The sixth switching element Tr6 in the embodiment includes a gate electrode connected to the nth emission control line ELn, and is connected between the third node N3 and the first electrode of the LED.

[0271] Fig.13 The first compensation switching element Trc1 in the embodiment includes a gate electrode connected to the first compensation line CL1, and is connected between the first driving power line VDL and the fourth node N4.

[0272] Fig.13 The second compensation switching element Trc2 in the embodiment includes a gate electrode connected to the second compensation line CL2, and is connected between the second electrode of the LED and the second driving power line VSL.

[0273] Fig.13 The first storage capacitor Cst1 in is connected between the fourth node N4 and the first node N1.

[0274] Fig.13 The second storage capacitor Cst2 is connected between the nth scan line SLn and the first node N1.

[0275] Fig.13 The LED in is connected between the drain electrode of the sixth switching element Tr6 and the source electrode of the second compensation switching element Trc2. That is, the first electrode of the LED is connected to the drain electrode of the sixth switching element Tr6, and the second electrode of the LED is connected to the source electrode of the second compensation switching element Trc2.

[0276] Fig.13 The first compensation switch element Trc1 and the second compensation switch element Trc2 are respectively connected to Fig.11 The first compensation switching element Trc1 and the second compensation switching element Trc2 are identical (or substantially identical) to each other.

[0277] In some example embodiments, from Fig.13 The structure in which the first compensation switching element Trc1 and the second compensation switching element Trc2 are omitted can be applied to the above-described Figure 1 Pixels in .

[0278] In some example embodiments, the compensation voltages Vc, Vc1, and Vc2 described above may be applied from one of the data driver 153, the power supply 123, and the timing controller 122, instead of being applied from the scan driver 151. In such example embodiments, the compensation line CL may be connected to one of the elements 153, 123, and 122 described above, instead of being connected to the scan driver 151. In addition, in such example embodiments, the lookup table LUT may be connected to one of the elements 153, 123, and 122 described above, instead of being connected to the scan driver 151.

[0279] In some example embodiments, Figure 8 The first driving power lines VDL in the embodiment may be individually connected to an "i*j" number of pixels PX. To this end, the first driving power lines VDL may include an "i*j" number of first driving power lines VDL separated from each other. The "i*j" number of first driving power lines VDL are individually connected to an "i*j" number of pixels PX. In some example embodiments, Figure 8 The lookup table LUT in provides information about the number of LEDs for each pixel PX to the power supply 123. In some example embodiments, Figure 8 The power supply 123 in the embodiment calculates the first driving voltage VDD of each pixel PX based on the number of LEDs of each pixel PX provided from the lookup table LUT, and applies the first driving voltage VDD to the pixel PX through the first driving power line VDL, respectively. For example, the fewer the number of LEDs of the pixel PX, the lower the first driving voltage VDD applied to the pixel PX.

[0280] When the first driving power line VDL is individually connected to each pixel PX as described above, Figure 8 The compensation line CL and Fig. 9 The compensation switch element Trc in is omitted. For example, each pixel PX may have Figure 2 In addition, each pixel PX may have Figures 10 to 13 The structures of the compensation lines CL1 and CL2 and the compensation switch elements Trc1 and Trc2 are omitted.

[0281] In another example embodiment, Figure 8 The second driving power lines VSL in the embodiment may be individually connected to the “i*j” number of pixels PX. To this end, the second driving power lines VSL may include the “i*j” number of second driving power lines VSL separated from each other. The “i*j” number of second driving power lines VSL are individually connected to the “i*j” number of pixels PX. In such an example embodiment, Figure 8The lookup table LUT in provides information about the number of LEDs for each pixel PX to the power supply 123. In such an example embodiment, Figure 8 The power supply 123 in the embodiment calculates the second driving voltage VSS of each pixel PX based on the number of LEDs of each pixel PX provided from the lookup table LUT, and applies the second driving voltage VSS to the pixel PX through the second driving power line VSL, respectively. For example, the fewer the number of LEDs of the pixel PX, the lower the second driving voltage VSS applied to the pixel PX.

[0282] When the second driving power line VSL is individually connected to each pixel PX as described above, Figure 8 The compensation line CL and Fig. 9 The compensation switch element Trc in is omitted. For example, each pixel PX may have Figure 2 In addition, each pixel PX may have Figures 10 to 13 The structures of the compensation lines CL1 and CL2 and the compensation switch elements Trc1 and Trc2 are omitted.

[0283] In another example embodiment, Figure 8 The first driving power line VDL and the second driving power line VSL in the embodiment may be individually connected to an “i*j” number of pixels PX. To this end, the first driving power line VDL may include an “i*j” number of first driving power lines VDL separated from each other, and the second driving power line VSL may include an “i*j” number of second driving power lines VSL separated from each other. The “i*j” number of first driving power lines VDL are individually connected to an “i*j” number of pixels PX, and the “i*j” number of second driving power lines VSL are individually connected to an “i*j” number of pixels PX. In such an example embodiment, Figure 8 The lookup table LUT in provides information about the number of LEDs for each pixel PX to the power supply 123. In such an example embodiment, Figure 8 The power supply 123 in the embodiment calculates the first driving voltage VDD and the second driving voltage VSS of each pixel PX based on the number of LEDs of each pixel PX provided from the lookup table LUT, applies the first driving voltage VDD to the pixel PX through the first driving power line VDL, and applies the second driving voltage VSS to the pixel PX through the second driving power line VSL. For example, the fewer the number of LEDs of the pixel PX, the lower the level of the first driving voltage VDD and the second driving voltage VSS applied to the pixel PX.

[0284] As set forth above, the display device according to one or more example embodiments of the present invention may provide the following effects.

[0285] First, the grayscale value of the image data signal of the pixel is compensated based on the number of LEDs of the pixel. Therefore, pixels including different numbers of LEDs can emit light of the same color.

[0286] Second, the compensation voltage of a pixel is set based on the number of LEDs of the pixel. Thus, pixels including different numbers of LEDs can emit light of the same color.

[0287] While the invention has been shown and described with reference to embodiments thereof, it will be apparent to those skilled in the art that various changes in form and details may be made without departing from the spirit and scope of the invention as defined by the appended claims and their equivalents.

Claims

1. A display device, comprising: Display panel; A pixel, located on the display panel, wherein the pixel includes at least one light emitting element; a timing controller configured to receive an image data signal of the pixel and compensate a grayscale value of the image data signal based on the number of the light emitting elements of the pixel to generate a compensated image data signal; as well as a data driver configured to select a compensation data signal corresponding to the compensated image data signal from the timing controller and apply the compensation data signal to the pixel, wherein the timing controller is configured to compare the number of the light emitting elements of the pixel with a predetermined reference value, and generate the compensated image data signal based on the comparison result, and Wherein, when the number of the light-emitting elements of the pixel is less than the reference value, the compensated image data signal has a grayscale value smaller than the grayscale value of the image data signal; and when the number of the light-emitting elements of the pixel is greater than the reference value, the compensated image data signal has a grayscale value greater than the grayscale value of the image data signal.

2. The display device according to claim 1, wherein: As the number of the light emitting elements of the pixel becomes smaller, the compensated image data signal has a smaller grayscale value.

3. The display device according to claim 1, wherein: When the number of the light emitting elements of the pixel is less than the reference value, as the difference between the number of the light emitting elements of the pixel and the reference value becomes larger, the compensated image data signal has a smaller grayscale value.

4. The display device according to claim 1, wherein: When the number of the light emitting elements of the pixel is greater than the reference value, as the difference between the number of the light emitting elements of the pixel and the reference value becomes larger, the compensated image data signal has a larger grayscale value. 5 . The display device according to claim 1 , further comprising a lookup table storing the number of the light emitting elements of the pixel.

6. The display device according to claim 1, wherein: At least one of the light emitting elements is a nano light emitting element.

7. The display device according to claim 1, wherein: The compensation data signal from the data driver is applied to the pixel through the data line of the display panel.

8. The display device according to claim 7, wherein: The pixels include: A first switching element, comprising a gate electrode connected to a gate line of the display panel, the first switching element being connected between the data line and a node; a second switching element including a gate electrode connected to the node, the second switching element being connected between a first driving power line of the display panel and a first electrode of the light emitting element; and A capacitor is connected between the node and the first driving power line.

9. The display device according to claim 8, wherein: The second electrode of the light emitting element is connected to a second driving power line of the display panel.

10. A display device comprising: A display panel including pixels connected to a first driving power line, a second driving power line, a data line, and a first compensation line; as well as a driving circuit configured to generate a first compensation voltage based on the number of light-emitting elements of the pixel and apply the first compensation voltage to the first compensation line, wherein when the number of the light-emitting elements of the pixel is less than a predetermined reference value, the first compensation voltage has a magnitude smaller than a magnitude of a predetermined reference compensation voltage; and when the number of the light-emitting elements of the pixel is greater than the reference value, the first compensation voltage has a magnitude greater than a magnitude of the reference compensation voltage, Wherein, the pixels include: A driving switch element configured to receive a data signal from the data line; at least one light emitting element connected to the driving switch element; and The first compensation switch element includes a gate electrode connected to the first compensation line, and the first compensation switch element is connected between the first driving power line and the driving switch element.

11. The display device according to claim 10, wherein: As the number of the light emitting elements of the pixel becomes smaller, the first compensation voltage has a smaller value.

12. The display device according to claim 10, wherein: When the number of the light emitting elements of the pixel is less than the reference value, the first compensation voltage has a value smaller than a value of a predetermined reference compensation voltage.

13. The display device according to claim 12, wherein: As the difference between the number of the light emitting elements of the pixel and the reference value becomes larger, the first compensation voltage has a smaller value.

14. The display device according to claim 10, wherein: When the number of the light emitting elements of the pixel is greater than the reference value, the first compensation voltage has a value greater than a value of a predetermined reference compensation voltage.

15. A display device comprising: A display panel including pixels connected to a first driving power line, a second driving power line, a data line, and a first compensation line; as well as a driving circuit configured to generate a first compensation voltage based on the number of light emitting elements of the pixel and apply the first compensation voltage to the first compensation line, Wherein, the pixels include: A driving switch element configured to receive a data signal from the data line; at least one light emitting element connected to the driving switch element; a first compensation switch element, comprising a gate electrode connected to the first compensation line, the first compensation switch element being connected between the light emitting element and the second driving power line; and The driving circuit is configured to compare the number of the light-emitting elements of the pixel with a predetermined reference value, and generate a compensated image data signal based on the comparison result, wherein when the number of the light-emitting elements of the pixel is less than the reference value, the compensated image data signal has a grayscale value smaller than the grayscale value of the image data signal; and when the number of the light-emitting elements of the pixel is greater than the reference value, the compensated image data signal has a grayscale value greater than the grayscale value of the image data signal.

16. The display device according to claim 15, wherein: As the number of the light emitting elements of the pixel becomes smaller, the first compensation voltage has a smaller value.

Images