The present invention relates to a display technology, and in particular, to a display apparatus and method for driving pixels thereof.
Due to properties such as low power consumption, low radiation, light weight and thin shapes, LCD displays have become important and highly used electronic products. In addition, with continued advances in technology, the frame resolution of LCD display apparatuses continues to improve, resulting in an increase in power consumption. Thus, reducing power consumption of a display apparatus without affecting the display quality has become an important objective.
The present invention provides a display apparatus and method for driving pixels thereof, by which the power consumption of a display apparatus may be reduced.
The display apparatus of embodiments of the present invention includes a source driver, a plurality of data lines and a plurality of pixels. The source driver receives a polarity signal and a frame switching signal and has a plurality of data channels. The data channels alternately provide a plurality of first pixel voltages and a plurality of second pixel voltages according to the polarity signal, wherein each of the data channels alternatively outputs the corresponding first pixel voltage and the corresponding second pixel voltage according to the polarity signal and the frame switching signal. The first pixel voltages have a first drive capability, and the second pixel voltages have a second drive capability. The data lines are coupled to the source driver, for receiving the first pixel voltages and the second pixel voltages. The pixels are coupled to the data lines to receive the corresponding first pixel voltage or the corresponding second pixel voltage.
The pixel driving method according to embodiments of the present invention is suitable for a plurality of pixels coupled to a source driver, and includes the steps of: providing a plurality of data channels through the source driver, to alternately provide a plurality of first pixel voltages and a plurality of second pixel voltages, wherein each of the data channels alternatively outputs the corresponding first pixel voltage and the corresponding second pixel voltage according to a polarity signal and a frame switching signal, the first pixel voltages have a first drive capability, and the second pixel voltages have a second drive capability; and providing a plurality of data lines to transmit the first pixel voltages and the second pixel voltages to the pixels.
According to the display apparatus and method for driving pixels thereof of embodiments of the present invention, the data channels thereof alternatively output the first pixel voltages having the first drive capability and the second pixel voltages having the second drive capability to the pixels according to the polarity signal and the frame switching signal. As such, the formation of differences in drive capabilities of writing frames can be prevented and the power consumption for writing frames can be reduced.
To assist in the understanding of the present invention, the following embodiments are described in detail in conjunction with accompanying figures.
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In the first embodiment, the frame switching signal XFS is configured to represent switching of frame periods; namely, the frame switching signal XFS may be a vertical blanking signal, but embodiments of the present invention are not limited thereto. The source driver 110 generates the first pixel voltages VP1 and the second pixel voltages VP2 according to a driving mode of column inversion; namely, the first pixel voltages VP1 and the second pixel voltages VP2 are alternately outputted, and during one frame period, each output end keeps outputting the first pixel voltage VP1 or the second pixel voltage VP2.
The source driver 110 includes a shift register 111, a plurality of data channels (such as channels 113_1 through 113_4) and a first drive capability setting unit 115. The shift register 111 receives the data signal XDD to provide a plurality of display data XDP to the data channels (such as channels 113_1 through 113_4). The data channels (such as channels 113_1 through 113_4) receive the polarity signal XPOL, the frame switching signal XFS and the latch signal XSTB, and alternately provide the first pixel voltages VP1 and the second pixel voltages VP2 according to the polarity signal XPOL; namely, two adjacent data channels of the plurality of data channels (such as 113_1 through 113_2) provide the first pixel voltage VP1 and the second pixel voltage VP2 respectively. Each of the data channels determines whether to convert the received display data XDP according to the latch signal XSTB, and each of the data channels alternatively outputs the corresponding first pixel voltage VP1 and the corresponding second pixel voltage VP2 according to the polarity signal XPOL and the frame switching signal XFS. In other words, in one frame period, each of the data channels provides the corresponding first pixel voltage VP1; in the next frame period, each of the data channels provides the corresponding second pixel voltage VP2.
The first drive capability setting unit 115 is coupled to the data channels and receives the polarity signal XPOL, the frame switching signal XFS and the latch signal XSTB, to provide a first bias VB1 and a second bias VB2 to the data channels, wherein the first bias VB1 is configured to set the first pixel voltages VP1 to have the first drive capability, and the second bias VB2 is configured to set the second pixel voltages VP2 to have the second drive capability. As used herein, the term “coupled” means either a direct electrical connection, or an electrical connection through one or more intermediary components which intermediary components don't have an appreciable impact on the electrical signal.
Furthermore, the first drive capability setting unit 115 includes a first bias circuit 117, a second bias circuit 119 and a plurality of first voltage transmission circuits (such as VSC11, VSC12). The first bias circuit 117 is configured to provide the first bias VB1. The second bias circuit 119 is configured to provide the second bias VB2. The first voltage transmission circuits (VSC11, VSC12) receive the polarity signal XPOL, the latch signal XSTB and the frame switching signal XFS, and are respectively coupled to the first bias circuit 117, the second bias circuit 119 and disposed between two adjacent data channels of the plurality of data channels (i.e., 113_1 through 113_4). According to the polarity signal XPOL, the latch signal XSTB and the frame switching signal XFS, each of the first voltage transmission circuits (VSC11, VSC12) transmits the first bias VB1 and the second bias VB2 to two adjacent data channels of the plurality of data channels respectively.
The display panel 120 includes a plurality of data lines (such as data lines 121_1 through 121_5) and a plurality of pixels (such as red pixels PR, green pixels PG and blue pixels PB). The data lines (121_1, 121_5) are coupled to the source driver 110, for receiving the first pixel voltages VP1 and the second pixel voltages VP2. The pixels (such as PR, PG and PB) are coupled to the data lines (121_1, 121_5121_1 through 121_5) to receive the corresponding first pixel voltage VP1 or the corresponding second pixel voltage VP2. In the present embodiment, the pixels (such as PR, PG and PB) and the data lines (121_1, 121_5121_1 through 121_5) are coupled to each other in a Z-shaped pixel arrangement; namely, the pixels (such as PR, PG and PB) to which each of the data lines (121_1, 121_5121_1 through 121_5) is coupled are located in two adjacent columns of pixels, and the pixels (such as PR, PG and PB) to which each of the data lines (121_1, 121_5121_1 through 121_5) corresponds are located in different rows and not adjacent to each other.
For example, in a first frame period, the data channels (113_1 through 113_4) provide the first pixel voltages VP1 to the pixels (such as PR, PG and PB) respectively through even data lines (such as 121_2, 121_4, corresponding to first data lines) in the data lines (121_1, 121_5121_1 through 121_5) according to the polarity signal XPOL and the frame switching signal XFS, and the data channels (113_1 through 113_4) provide the second pixel voltages VP2 to the pixels (PR, PG and PB) respectively through odd data lines (such as 121_1, 121_3, 121_5, corresponding to second data lines) in the data lines (121_1, 121_5121_1 through 121_5) according to the polarity signal XPOL and the frame switching signal XFS. In a second frame period following the first frame period, the data channels (113_1 through 113_4) provide the second pixel voltages VP2 to the pixels (PR, PG and PB) respectively through the even data lines (such as 121_2, 121_4) according to the polarity signal XPOL and the frame switching signal XFS, and the data channels (113_1 through 113_4) provide the first pixel voltages VP1 to the pixels (PR, PG and PB) respectively through the odd data lines (such as 121_1, 121_3, 121_5) according to the polarity signal XPOL and the frame switching signal XFS. In accordance with the above, the first data lines are different from the second data lines in embodiments of the present invention.
In embodiments of the present invention, the display apparatus 100 may further include a timing controller (not shown) and a gate driver (not shown), and the display panel 120 may further comprise scan lines. The scan lines are coupled to the gate driver and the corresponding pixels (PR, PG and PB), to drive the pixels (PR, PG and PB) row by row. The gate driver is controlled by the timing controller to provide a gate signal to the scan lines, and the source driver 110 is controlled by the timing controller to provide the first pixel voltages VP1 or the corresponding second pixel voltages VP2 to the data lines (121_1, 121_5121_1 through 121_5); namely, the timing controller can provide the data signal XDD, the polarity signal XPOL, the frame switching signal XFS and the latch signal XSTB to the source driver 110.
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In accordance with the above, the writing of the red frames, the green frames and the blue frames all make use of the first pixel voltages VP1 and the second pixel voltages VP2; namely, the drive capabilities in writing the red frames, the green frames and the blue frames are generally the same, and thus the differences in drive capabilities are prevented from affecting the display of frames. The writing of the red frames, the green frames and the blue frames each use the first pixel voltages VP1 having a lower drive capability, and thus power consumption for writing frames is reduced.
In addition, in certain embodiments, the form of the data channels (113_1 through 113_4) is an electrical property affecting the pixel voltages (such as the first pixel voltages VP1 and the second pixel voltages VP2). For example, when the data channels (113_1 through 113_4) are formed of NMOS transistors, the first pixel voltages VP1 (here, pixel voltages greater than a common voltage) have a rise time of 0.96 μs and a fall time of 1.22 μs, and the second pixel voltages VP2 (here, pixel voltages less than the common voltage) have a rise time of 1.28 μs and a fall time of 0.98 μs. As described above, the rise times (i.e., charging capabilities) of the first pixel voltages VP1 and the second pixel voltages VP2 are different from each other, and thus the charging capabilities of the first pixel voltages VP1 and the second pixel voltages VP2 can be made generally the same through adjustments of the drive capabilities, so as to prevent frames from flickering, thereby improving the quality of frames.
In the present embodiment, the pixels (such as PD, PR, PG and PB) and the data lines (221_1 through 221_5) are coupled to each other in a generally Z-shaped pixel arrangement; namely, the pixels (such as PD, PR, PG and PB) to which each of the data lines (221_1 through 221_5) is coupled are located in four adjacent columns of pixels. Among the pixels (PD, PR, PG and PB) to which each of the data lines (221_1 through 221_5) corresponds, those located in different rows of the pixels (PD, PR, PG and PB) are not adjacent to each other, while those located in the same rows of pixels (PD, PR, PG and PB) are adjacent to each other.
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In accordance with the above, in the generally Z-shaped pixel arrangement, the writing of the red frames, the green frames and the blue frames all make use of the first pixel voltages VP1 and the second pixel voltages VP2; namely, the drive capabilities in writing the red frames, the green frames and the blue frames are generally the same.
When the frame rate command XCF sets the display apparatus 300 at a high frame rate mode (i.e., the frame rate of the display apparatus 300 is greater than or equal to 120 Hertz), the second drive capability setting unit 311 transmits the third bias VB3 and the fourth bias VB4 to the data channels (113_1 through 113_4) to set the first drive capability of the first pixel voltages VP1 to be lower than the second drive capability of the second pixel voltages VP2; on the contrary, when the frame rate command XCF sets the display apparatus 300 not to be at the high frame rate mode (i.e., the frame rate of the display apparatus 300 is less than 120 Hertz), the second drive capability setting unit 311 transmits one of the third bias VB3 and the fourth bias VB4 to the data channels (113_1 through 113_4) to set the first drive capability of the first pixel voltages VP1 to be equal to the second drive capability of the second pixel voltages VP2.
Furthermore, the second drive capability setting unit 311 includes a third bias circuit 313, a fourth bias circuit 315 and a plurality of second voltage transmission circuits (such as VSC21, VSC22). The third bias circuit 313 is configured to provide the third bias VB3. The fourth bias circuit 315 is configured to provide the fourth bias VB4. The second voltage transmission circuits (such as VSC21, VSC22) receive the polarity signal XPOL, the frame rate command XCF, the latch signal XSTB, and the frame switching signal XFS, and are respectively coupled to the third bias circuit 313, the fourth bias circuit 315 and disposed between two adjacent data channels of the plurality of data channels (113_1 through 113_4). When the frame rate command XCF sets the frame rate of the display apparatus 300 at greater than or equal to 120 Hertz, each of the second voltage transmission circuits (such as VSC21, VSC22) respectively transmits the third bias VB3 and the fourth bias VB4 to two adjacent data channels of the plurality of data channels (113_1 through 113_4) according to the polarity signal XPOL, the latch signal XSTB and the frame switching signal XFS; on the contrary, when the frame rate command XCF sets the frame rate of the display apparatus 300 at lower than 120 Hertz, the second voltage transmission circuits (such as VSC21, VSC22) collectively transmit one of the third bias VB3 and the fourth bias VB4 to the data channels (113_1 through 113_4).
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The level shifter 520 is coupled to the latch 510 to provide a to-be-converted display data XTDP according to the latch display data XLDP. The digital-to-analog converter 530 is coupled to the level shifter 520 and receives a plurality of gamma voltages VGM and the polarity signal XPOL, for converting the display data XTDP to be converted into a pixel reference voltage VPRX. The output buffer 540 is coupled to the digital-to-analog converter 530 and receives the pixel reference voltage VPRX and the polarity signal XPOL, to provide the first pixel voltages VP1 or the second pixel voltages VP2.
When the output buffer 540 is coupled to the first drive capability setting unit 115, the output buffer 540 receives the first bias VB1 or the second bias VB2; when the output buffer 540 is coupled to the second drive capability setting unit 311, the output buffer 540 receives the third bias VB3 or the fourth bias VB4. When the output buffer 540 receives the first bias VB1 and the third bias VB3, the output buffer 540 provides the first pixel voltages VP1 having the first drive capability; when the output buffer 540 receives the second bias VB2 and the fourth bias VB4, the output buffer 540 provides the second pixel voltages VP2 having the second drive capability.
To sum up the above, according to the display apparatus and method for driving pixels thereof according to the embodiments of the present invention, the data channels alternatively output the first pixel voltages having the first drive capability and the second pixel voltages having the second drive capability to the display panel with a Z-shaped pixel arrangement according to the polarity signal and the frame switching signal. As such, the differences in drive capability of writing frames can be prevented from resulting in poor image quality, and the power consumption for writing frames can be reduced.
Even though the present invention has been disclosed as the abovementioned embodiments, it is not limited thereto. Any person of ordinary skill in the art may make some changes and adjustments without departing from the spirit and scope of the present invention. Therefore, the scope of the present invention is defined in view of the appended claims.
Number | Date | Country | Kind |
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104135029 | Oct 2015 | TW | national |