This application claims the benefit of Korean Patent Application No. 10-2015-0061857 filed on Apr. 30, 2015, the entire contents of which are incorporated herein by reference for all purposes as if fully set forth herein.
Field of the Invention
The present invention relates to a display device.
Discussion of the Related Art
Examples of a flat panel display include a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP), and an organic light emitting diode (OLED) display. In a flat panel display, data lines and gate lines are typically arranged to cross each other, and a pixel is defined by each crossing of the data lines and the gate lines. A plurality of pixels are formed on a display panel of the flat panel display in a matrix form. The flat panel display supplies a video data voltage to the data lines and sequentially supplies a gate pulse to the gate lines, thereby driving the pixels. The flat panel display supplies the video data voltage to the pixels of a gate line, to which the gate pulse is supplied, and sequentially scans all of the gate lines with the gate pulse, thereby displaying video data.
The data voltage supplied to a data line is generated in a data driver, and the data driver outputs the data voltage through a source channel connected to the data line. Recently, a structure, in which a plurality of data lines are connected to one source channel, and the source channel and the data lines are selectively connected using a multiplexer (MUX), is used to reduce the number of source channels. The interval between MUX signals decreases as the resolution and the size of the display panel increase. Further, because the MUX signals are delayed in a display panel of a high resolution, adjacent MUX signals may overlap each other. When the MUX signals overlap each other, the data voltage output from the source channel may be supplied to an unintended data line. Hence, the display quality of the flat panel display may be reduced.
Accordingly, the present invention is directed to a display device that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, a display device includes: a display panel including a plurality of subpixels of a plurality of colors arranged in a matrix form, and a plurality of gate lines and data lines respectively connected to the subpixels; a data driver configured to supply data voltages to the subpixels through a plurality of source channels and the data lines; and a switch circuit configured to connect one of the source channels selectively to one of the data lines during a first scan period in one horizontal period and to a different one of the data lines during a second scan period in the one horizontal period, wherein the data driver is configured to supply data voltages of one color to the one of the source channels during both the first scan period and the second scan period in the one horizontal period.
In another aspect, a display device includes: a first subpixel group including a first subpixel of a first color, a second subpixel of a second color, and a third subpixel of a third color; a second subpixel group including a fourth subpixel of the first color, a fifth subpixel of the second color, and a sixth subpixel of the third color; a plurality of data lines and a plurality of gate lines, the data lines including at least first to sixth data lines respectively connected to the first to the sixth subpixels, and the gate lines including at least a first gate line connected to each of the first to the sixth subpixels; a data driver configured to supply data voltages respectively to a plurality of source channels including at least a first source channel, a second source channel, and a third source channel; and a switch circuit configured to selectively connect the first source channel at least to the first data line and the fourth data line, the second source channel at least to the second data line and the fifth data line, and the third source channel at least to the third data line and the sixth data line.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. In the drawings:
Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
As shown in
The display panel 100 includes a pixel array, in which pixels are arranged in a matrix form and which displays input image data. As shown in
The timing controller 200 may receive digital video data RGB and timing signals, such as a vertical sync signal Vsync, a horizontal sync signal Hsync, a data enable signal DE, and a main clock CLK, from an external host. The timing controller 200 may transmit the digital video data RGB to the data driver 400. The timing controller 200 may generate a source timing control signal for controlling operation timing of the data driver 400 and a gate timing control signal for controlling operation timing of the gate driver 300 using the timing signals Vsync, Hsync, DE, and CLK.
The gate driver 300 outputs a gate pulse Gout using the gate timing control signal. The gate timing control signal may include a gate start pulse GSP, a gate shift clock GSC, and a gate output enable signal GOE. The gate start pulse GSP indicates a start gate line, to which the gate driver 300 outputs a first gate pulse Gout. The gate shift clock GSC is a clock for shifting the gate start pulse GSP. The gate output enable signal GOE sets an output period of the gate pulse Gout.
As shown in
A display device according to the first example embodiment is described in detail below.
The display panel 100 includes red subpixels R, green subpixels G, and blue subpixels B arranged along column lines. The red subpixels R are arranged along a (3m−2)-th column line C(3m−2), where m is a natural number. The green subpixels G are arranged along a (3m−1)-th column line C(3m−1), and the blue subpixels B are arranged along a (3m)-th column line C(3m). For example, the red subpixels R are arranged along a first column line C1, a fourth column line C4, and a seventh column line C7. The green subpixels G are arranged along a second column line C2, a fifth column line C5, and an eighth column line C8. The blue subpixels B are arranged along a third column line C3, a sixth column line C6, and a ninth column line C9.
The first to the 3m-th data lines DL1 to DL3m are disposed along the direction of the first to the 3m-th column lines C1 to C3m.
The first to the 3m-th data lines DL1 to DL3m receive the data voltage through source channels S1 to Sm used to output the data voltage from the data driver 400. Each of the source channels S1 to Sm is connected to three corresponding data lines. For example, a (3i−2)-th source channel is connected to a (3i−2)-th data line, a (3(i+1)−2)-th data line, and a (3(i+2)−2)-th data line, where “i” is a natural number satisfying a condition of “3i=m”. A (3i−1)-th source channel may be connected to a (3i−1)-th data line, a (3(i+1)−1)-th data line, and a (3(i+2)−1)-th data line. A (3i)-th source channel may be connected to a (3i)-th data line, a (3(i+1))-th data line, and a (3(i+2))-th data line. For example, the first source channel S1 may be connected to the first data line DL1, the fourth data line DL4, and the seventh data line DL7. The second source channel S2 may be connected to the second data line DL2, the fifth data line DL5, and the eighth data line DL8. The third source channel S3 may be connected to the third data line DL3, the sixth data line DL6, and the ninth data line DL9.
The gate lines GL may include the first to the n-th gate lines GL1 to GLn for supplying the gate pulse during the first to the n-th horizontal periods t1 to tn, where n is a natural number. The gate driver 300 may supply the gate pulse to the first gate line GL1 during the first horizontal period G1, to the second gate line GL2 during the second horizontal period G2, to the third gate line GL3 during the third horizontal period G3, and so on.
A switching unit 150 according to the first example embodiment includes the first to the third switching elements SW1 to SW3 so as to switch an output of the source channels. Each of the first to the third switching elements SW1 to SW3 includes switching parts corresponding to the number of source channels. The first switching element SW1 operates in response to a first MUX signal MUX1, the second switching element SW2 operates in response to a second MUX signal MUX2, and the third switching element SW3 operates in response to a third MUX signal MUX3.
The MUX controller 600 outputs the first MUX signal MUX1 during the first scan period t1, outputs the second MUX signal MUX2 during the second scan period t2, and outputs the third MUX signal MUX3 during the third scan period t3.
During the first scan period t1, the first switching element SW1 connects the first source channel S1 to the first data line DL1, connects the second source channel S2 to the second data line DL2, and connects the third source channel S3 to the third data line DL3, in response to the first MUX signal MUX1.
During the second scan period t2, the second switching element SW2 connects the first source channel S1 to the fourth data line DL4, connects the second source channel S2 to the fifth data line DL5, and connects the third source channel S3 to the sixth data line DL6, in response to the second MUX signal MUX2.
During the third scan period t3, the third switching element SW3 connects the first source channel S1 to the seventh data line DL7, connects the second source channel S2 to the eighth data line DL8, and connects the third source channel S3 to the ninth data line DL9, in response to the third MUX signal MUX3.
During one horizontal period, the data driver 400 supplies the data voltage of the same color to each source channel. In
During one horizontal period 1H, the data driver 400 outputs a red data voltage to the first source channel S1, outputs a green data voltage to the second source channel S2, and outputs a blue data voltage to the third source channel S3, for example. More specifically, the data driver 400 supplies the data voltage to the color subpixels connected to a (3m−2)-th data line, a (3m−1)-th data line, and a (3m)-th data line during the first scan period t1. The data driver 400 supplies the data voltage to the color subpixels connected to a (3(m+1)−2)-th data line, a (3(m+1)−1)-th data line, and a 3(m+1)-th data line during the second scan period t2. The data driver 400 supplies the data voltage to the color subpixels connected to a (3(m+2)−2)-th data line, a (3(m+2)−1)-th data line, and a 3(m+2)-th data line during the third scan period t3.
Namely, the data driver 400 may supply the data voltage to the red subpixel R11 of the first column line C1 and to the green subpixel G12 of the second column line C2 on the first horizontal line L1 via data lines DL2 and DL3, respectively, during the first scan period t1 of one horizontal period 1H. In this example, the first data line DL1 is not connected to a pixel on the odd-numbered horizontal lines, including the first horizontal line L1.
The data driver 400 may supply the data voltage to the blue subpixel B13 of the third column line C3, the red subpixel R14 of the fourth column line C4, and the green subpixel G15 of the fifth column line C5 on the first horizontal line L1 during the second scan period t2 of one horizontal period 1H.
The data driver 400 may supply the data voltage to the blue subpixel B16 of the sixth column line C6, the red subpixel R17 of the seventh column line C7, and the green subpixel G18 of the eighth column line C8 on the first horizontal line L1 during the third scan period t3 of one horizontal period 1H.
The data driver 400 may respectively supply the data voltages of opposite polarities to an odd-numbered source channel and an even-numbered source channel for a horizontal 1-dot inversion drive. For example, the data driver 400 may output the positive data voltage to the first source channel S1 and may output the negative data voltage to the second source channel S2.
The display device according to the first example embodiment selectively connects each source channel to the plurality of data lines and supplies the data voltage to the data lines. Thus, the display device according to the first example embodiment may supply the data voltage to the entire display panel through a number of source channels, which is lower than the number of data lines. In other words, the display device according to the first example embodiment may reduce the number of source channels of the data driver and may reduce power consumption.
In particular, because the display device according to the first example embodiment outputs the same color data voltage to each respective source channel during one horizontal period 1H, the display device according to the first example embodiment may prevent or lessen a reduction in the display quality resulting from a mixed color even when the MUX signals are delayed. This is described in detail below.
As a resolution of the display panel 100 increases, a length of each of the first to third scan periods t1 to t3 gradually decreases. Hence, an output period of each of the first to the third MUX signals MUX1 to MUX3 in the first to the third scan periods t1 to t3 decreases. As the size of the display panel 100 increases, the delay of the first to the third MUX signals MUX1 to MUX3 increases. An example waveform of the MUX signals MUX1 to MUX3 in theory is shown in
On the other hand, the display device according to the first embodiment outputs the data voltage of one color through each of the source channels S1 to Sm during one horizontal period. Because the data voltage output through each source channel is the data voltage of the adjacent subpixels of the same color, there may unlikely be a large difference between the data voltages. As a result, even if the delay of the MUX signals MUX1 to MUX3 is generated, the display device according to the first example embodiment may prevent large unintended changes in the color the subpixels represent.
The display device according to the second example embodiment is described in detail below.
A display panel 100 includes red subpixels R, green subpixels G, and blue subpixels B arranged along column lines. The red subpixels R are arranged along a (3m−2)-th column line C(3m−2), where m is a natural number. The green subpixels G are arranged along a (3m−1)-th column line C(3m−1), and the blue subpixels B are arranged along a (3m)-th column line C(3m). In other words, the first to the 3m-th data lines DL1 to DL3m are arranged parallel to the first to the 3m-th column lines C1 to C3m.
The first to the 3m-th data lines DL1 to DL3m are disposed along a direction of the first to the 3m-th column lines C1 to C3m.
The first to the 3m-th data lines DL1 to DL3m receive a data voltage through source channels S1 to Sm used to output the data voltage through a data driver 400-1. Each of the source channels S1 to Sm is connected to the corresponding two of the data lines. A (3i−2)-th source channel is connected to a (3i−2)-th data line and a (3(i+1)−2)-th data line, where “i” is a natural number satisfying a condition of “3i=m”. A (3i−1)-th source channel is connected to a (3i−1)-th data line and a (3(i+1)−1)-th data line. A (3i)-th source channel is connected to a (3i)-th data line and a 3(i+1)-th data line. For example, the first source channel S1 is connected to the first data line DL1 and the fourth data line DL4. The second source channel S2 is connected to the second data line DL2 and the fifth data line DL5. The third source channel S3 is connected to the third data line DL3 and the sixth data line DL6.
Gate lines GL may include the first to the 2n-th gate lines GL1 to GLn for supplying gate pulses during the first to the n-th horizontal periods G1 and Gn, where n is a natural number. For example, a gate driver 300-1 supplies the gate pulse to the first gate line GL1 during the first horizontal period G1, to the second gate line GL2 during the second horizontal period G2, and so on.
A switching unit 150-1 according to the second example embodiment includes the first and the second switching elements SW1 and SW2 so as to switch an output of the source channels. The first switching element SW1 operates in response to a first MUX signal MUX1, and the second switching element SW2 operates in response to a second MUX signal MUX2.
A MUX controller 600 outputs the first MUX signal MUX1 during the first scan period t1 and outputs the second MUX signal MUX2 during the second scan period t2.
During the first scan period t1, the first switching element SW1 connects the first source channel S1 to the first data line DL1, connects the second source channel S2 to the second data line DL2, and connects the third source channel S3 to the third data line DL3 in response to the first MUX signal MUX1.
During the second scan period t2, the second switching element SW2 connects the first source channel S1 to the fourth data line DL4, connects the second source channel S2 to the fifth data line DL5, and connects the third source channel S3 to the sixth data line DL6 in response to the second MUX signal MUX2.
During one horizontal period, the data driver 400-1 supplies the data voltage of the same color to each source channel. For example, during one horizontal period 1H, the data driver 400-1 outputs a red data voltage to the first source channel S1, outputs a green data voltage to the second source channel S2, and outputs a blue data voltage to the third source channel S3. More specifically, the data driver 400-1 supplies the data voltage to the color subpixels connected to a (3m−2)-th data line, a (3m−1)-th data line, and a (3m)-th data line during the first scan period t1. The data driver 400-1 supplies the data voltage to the color subpixels connected to a (3(m+1)−2)-th data line, a (3(m+1)−1)-th data line, and a 3(m+1)-th data line during the second scan period t2.
Namely, the data driver 400-1 may supply the data voltage to the red subpixel R11 of the first column line C1, the green subpixel G12 of the second column line C2, and the blue subpixel B13 of the third column line C3 on the first horizontal line L1, via data lines DL1, DL2, and DL3, respectively, during the first scan period t1 of one horizontal period 1H. In this example, the first data line DL1 is not connected to a pixel on even-numbered horizontal lines, including the second horizontal line L2.
The data driver 400-1 may supply the data voltage to the red subpixel R14 of the fourth column line C4, the green subpixel G15 of the fifth column line C5, and the blue subpixel B16 of the sixth column line C6 on the first horizontal line L1 during the second scan period t2 of one horizontal period 1H.
The data driver 400-1 may change a polarity of the data voltage output in each horizontal period.
As described above, the display device according to the second example embodiment selectively connects each source channel to the plurality of data lines and supplies the data voltage to the data lines. Thus, the display device according to the second example embodiment may supply the data voltage to the entire display panel through a number of source channels, which is lower than the number of data lines. In other words, the display device according to the second example embodiment may reduce the number of source channels of the data driver and may reduce power consumption. In particular, because the display device according to the second example embodiment outputs the same color data voltage to each respective source channel during one horizontal period 1H, the display device according to the second example embodiment may prevent or lessen a reduction in the display quality resulting from a mixed color even when the MUX signals are delayed.
The display quality of the display device according to the first and second example embodiments may not be significantly reduced even when the MUX signals MUX1 to MUX3 are delayed. Therefore, a shorter interval between the MUX signals MUX1 to MUX3 may be adopted without a significant reduction in the display quality. In a related art device, as shown in
On the other hand, the display device according to the first or the second example embodiment does not necessarily need to secure a large interval between the MUX signals MUX1 to MUX3 equal to or longer than the delay period Td of the MUX, because the potential reduction in the display quality caused by the delay of the MUX signals MUX1 to MUX3 is much less significant than in the related art device. Thus, as shown
Accordingly, a length of an output period Tm′ of the MUX signal according to the first or the second example embodiment may be longer than a length of an output period Tm of the related art MUX signal. Because the output period of the MUX signal is a period in which the pixels are charged to the data voltage, the display device according to the first or the second example embodiment may increase a data charge time. Hence, the display device according to the first and second example embodiments may be advantageously applied to a display device of a high resolution.
The example embodiments of the present invention supply the data voltage of the same color to each respective source channel during the same horizontal period and thus can prevent or lessen a reduction in the display quality even if the unintended mixture of the data voltages resulting from the delay of the MUX signals occurs.
It will be apparent to those skilled in the art that various modifications and variations can be made in the display device of the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of the disclosed and illustrated example embodiments, provided they come within the scope of the appended claims and their equivalents.
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