DISPLAY APPARATUS AND PIXEL VOLTAGE DRIVING METHOD THEREOF
A display apparatus includes a pixel array, a data line and a data driver. The pixel array has adjacent first and second pixels disposed in different rows. The data line transmits first and second pixel voltages to be written into the first and second pixels respectively. The first and second pixel voltages are employed to illustrate a same frame. The data driver is utilized for generating the first and second pixel voltages furnished to the data line based on input image data. The data driver includes a voltage analysis unit and a voltage setting unit. The voltage analysis unit is used for calculating a voltage difference between the first and second pixel voltages, and for comparing the voltage difference with a preset value so as to generate a control signal. The voltage setting unit is utilized for setting the voltage of the data line according to the control signal.
1. Technical Field
The disclosure relates to a display apparatus and driving method thereof, and more particularly, to a display apparatus having adaptation-mode data line voltage driving mechanism and pixel voltage driving method thereof.
2. Description of the Related Art
Flat panel displays (FPDs) have advantages of a thin profile, low power consumption, and low radiation, and are broadly adopted for application in a variety of electronic appliances such as media players, mobile phones, personal digital assistants (PDAs), and computer monitors, etc. In general, the structure of a flat panel display includes a pixel array, a data driver, a scan driver, a plurality of data lines, and a plurality of scan lines. The data driver is utilized for providing plural data signals furnished to the pixel array via the data lines. The scan driver is utilized for providing plural scan signals furnished to the pixel array via the scan lines. The pixel array is employed to illustrate images through performing pixel voltage writing operations based on the data signals and the scan signals. However, as dimensions of the flat panel display increase, both trace resistance and parasitic capacitor of each data line increase, such that the switching of voltage at each data line incurs higher charge/discharge driving power consumption. For that reason, how to reduce charge/discharge driving power consumption in the process of voltage switching at each data line has become one of the most important topics nowadays.
SUMMARYIn accordance with an embodiment of the present invention, a pixel voltage driving method for reducing the data line driving power consumption of a display apparatus is provided. The display apparatus includes adjacent first and second pixels disposed indifferent rows. The pixel voltage driving method comprises: providing a first pixel voltage and a second pixel voltage to be written into the first and second pixels respectively; calculating a voltage difference between the first and second pixel voltages and comparing the voltage difference with a preset value for generating a comparison result; and performing a pixel voltage driving operation for writing the second pixel voltage into the second pixel according to the comparison result. It is noted that the first and second pixel voltages are employed to illustrate one and the same frame.
The present invention further provides a display apparatus having adaptation-mode data line voltage driving mechanism for reducing the data line driving power consumption. The display apparatus comprises a pixel array, a data line, and a data driver. The pixel array has adjacent first and second pixels disposed in different rows. The data line, electrically connected to the first and second pixels, is utilized for transmitting a first pixel voltage and a second pixel voltage to be written into the first and second pixels respectively. The first and second pixel voltages are employed to illustrate one and the same frame. The data driver, electrically connected to the data line, is employed to generate the first and second pixel voltages based on input image data. The data driver comprises a voltage analysis unit and a voltage setting unit. The voltage analysis unit is put in use for calculating a voltage difference between the first and second pixel voltages, and for comparing the voltage difference with a preset value so as to generate a control signal. The voltage setting unit, electrically connected to the voltage analysis unit and the data line, is utilized for setting a voltage at the data line according to the control signal.
These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.
Hereinafter, some embodiments of the present invention will be described in detail with reference to the accompanying drawings. Here, it is to be noted that the present invention is not limited thereto. Furthermore, the step serial numbers regarding the pixel voltage driving method are not meant thereto limit the operating sequence, and any rearrangement of the operating sequence for achieving same functionality is still within the spirit and scope of the invention.
The data driver 110 comprises a voltage analysis unit 112, a voltage setting unit 114, and a plurality of buffers 118. In another embodiment, the voltage analysis unit 112 is disposed in a timing controller (not shown) of the display apparatus 100. The voltage analysis unit 112 is employed to calculate a voltage difference Vdiff between the pixel voltages of two adjacent pixels disposed in different rows, and is further employed to compare the voltage difference Vdiff with a preset value Vpd for generating a control signal Sctr. For example, a difference calculation may be performed based on the pixel voltage VPn_m and the pixel voltage VPn+1_m for obtaining the voltage difference Vdiff which in turn is compared with the preset value Vpd for generating the control signal Sctr. The preset value Vpd may be a voltage difference between the highest and lowest pixel voltages. Alternatively, the preset value Vpd may be a positive voltage less than the voltage difference between the highest and lowest pixel voltages, e.g. the preset value Vpd may be half the voltage difference between the highest and lowest pixel voltages. The voltage setting unit 114, electrically connected to the voltage analysis unit 112 and the data lines 150, is utilized for setting each data line voltage according to the control signal Sctr, e.g. setting the voltage at the data line DLm based on the control signal Sctr generated through performing a comparison operation over the voltage difference Vdiff between the pixel voltage VPn_m and the pixel voltage VPn+1_m.
VPn+1_m is then written into the pixel Pn+1_m.
During an interval Tx between the interval TP1 and the interval
TP2, i.e. after writing the pixel voltage VPn_m into the pixel Pn_m and before furnishing the data signal SDm having the pixel voltage VPn+1_m to the data line DLm, if the voltage difference Vdiff is not less than the preset value Vpd, the voltage setting unit 114 sets the voltage at the data line DLm to be a reference voltage yr according to the control signal Sctr, e.g. connecting the data line DLm to a power line having the reference voltage Vr according to the control signal Sctr. The reference voltage Vr may be a ground voltage or an intermediate voltage between the highest and lowest pixel voltages. That is, in the process of switching the data signal SDm from the pixel voltage VPn_m to the pixel voltage VPn+1_m, the buffer 118 electrically connected to the data line DLm is required to convert the voltage at the data line DLm simply from the reference voltage Vr to the pixel voltage VPn+1_m, thereby significantly reducing the driving power consumption of the buffer 118. It is noted that the voltage setting unit 114 is required to disconnect the data line DLm from the aforementioned power line having the reference voltage Vr during the interval TP2, such that the buffer 118 connected to the data line DLm is allowed to output the pixel voltage VPn+1_m.
Alternatively, if the voltage difference Vdiff is less than the preset value Vpd, the voltage at the data line DLm is retained to be around the pixel voltage VPn_m during the interval Tx, for saving additional charge/discharge driving power consumption caused by unnecessary voltage switching of the data line DLm. In particular, when the pixel voltage VPn+1_m is equal to the pixel voltage VPn_m, if the voltage at the data line DLm is first switched from the pixel voltage VPn_m to the reference voltage Vr and then switched to the pixel voltage VPn+1_m, an unnecessary voltage switching operation over the data line DLm is performed, thereby resulting in additional charge/discharge driving power consumption. On the contrary, if the voltage at the data line DLm is retained to be around the pixel voltage VPn_m identical to the pixel voltage VPn+1_m during the interval Tx, the charge/discharge driving power consumption dissipated in the operation of the display apparatus 100 from the interval TP1 to the interval TP2 is almost null.
As shown in
As shown in
During a first interval Tx1 after the interval TP1, if the voltage difference Vdiff is not less than the preset value Vpd, the voltage setting unit 114 sets the voltage at the data line DLm to be a first reference voltage Vr1 according to the control signal Sctr. Further, during a second interval Tx2 between the first interval Tx1 and the interval TP2, the voltage setting unit 114 sets the voltage at the data line DLm to be a second reference voltage Vr2 different from the first reference voltage Vr1 according to the control signal Sctr. The first reference voltage Vr1 and the second reference voltage Vr2 are two intermediate voltages between the highest and lowest pixel voltages. That is, in the process of switching the data signal SDm from the pixel voltage VPn_m to the pixel voltage VPn+113 m, the buffer 118 electrically connected to the data line DLm is required to convert the voltage at the data line DLm simply from the second reference voltage Vr2 to the pixel voltage VPn+1_m, thereby significantly reducing the driving power consumption of the buffer 118. Alternatively, if the voltage difference Vdiff is less than the preset value Vpd, the voltage at the data line DLm is retained to be around the pixel voltage VPn_m during the first interval Tx1 and the second interval Tx2, for saving additional charge/discharge driving power consumption caused by unnecessary voltage switching of the data line DLm. It is noted that, in the operation of the display apparatus 100 based on the second pixel voltage driving method, the intermediate period between the interval TP1 and the interval TP2 may be divided into more intervals so as to provide a multi-stage voltage changing process of switching the data signal SDm from the pixel voltage VPn_m to the pixel voltage VPn+1_m with the aid of more reference voltages.
Step S810: providing the first pixel voltage VPn_m and the second pixel voltage VPn+1_m to be written into the first pixel Pn_m and the second pixel Pn+1_m respectively, wherein the first pixel voltage VPn_m and the second pixel voltage VPn30 113 m are employed to illustrate one and the same frame;
Step S815: writing the first pixel voltage VPn_m into the first pixel Pn_m;
Step S820: calculating the voltage difference Vdiff between the first pixel voltage VPn_m and the second pixel voltage VPn+1_m;
Step S825: judging whether the voltage difference Vdiff is greater or not less than the preset value Vpd; if the voltage difference Vdiff is greater or not less than the preset value Vpd, go to step S830; otherwise, go to step S880;
Step S830: setting the voltage of the data line DLm to be the reference voltage Vr during the interval after writing the first pixel voltage VPn_m into the first pixel Pn_m and before furnishing the second pixel voltage VPn+1_m to the second pixel Pn+1 m, wherein the data line DLm is electrically connected to the first pixel Pn_m and the second pixel Pn+lm;
Step S880: retaining the voltage of the data line DLm to be around the first pixel voltage VPn_m during the interval after writing the first pixel voltage VPn_m into the first pixel Pn_m and before furnishing the second pixel voltage VPn+1_m to the second pixel Pn+lm; and
Step S890: furnishing the second pixel voltage VPn+1_m to the data line DLm and writing the second pixel voltage VPn+1_m into the second pixel Pn+lm.
In the flow 800 of the first pixel voltage driving method described above, the preset value Vpd may be a voltage difference between the highest and lowest pixel voltages. Alternatively, the preset value Vpd may be a positive voltage less than the voltage difference between the highest and lowest pixel voltages, e.g. the preset value Vpd may be half the voltage difference between the highest and lowest pixel voltages. The reference voltage Vr may be a ground voltage or an intermediate voltage between the highest and lowest pixel voltages. In the embodiment shown in
Step S810: providing the first pixel voltage VPn_m and the second pixel voltage VPn+1_m to be written into the first pixel Pn_m and the second pixel Pn+1_respectively, wherein the first pixel voltage VPn_m and the second pixel voltage VPn+1_are employed to illustrate one and the same frame;
Step S815: writing the first pixel voltage VPn_m into the first pixel Pn_m;
Step S820: calculating the voltage difference Vdiff between the first pixel voltage VPn_m and the second pixel voltage VPn+1_;
Step S825: judging whether the voltage difference Vdiff is greater or not less than the preset value Vpd; if the voltage difference Vdiff is greater or not less than the preset value Vpd, go to step S840; otherwise, go to step S880;
Step S840: setting the voltage of the data line DLm to be the first reference voltage Vr1 during the first interval after writing the first pixel voltage VPn_m into the first pixel Pn_m, wherein the data line DLm is electrically connected to the first pixel Pn_m and the second pixel Pn+1_;
Step S845: setting the voltage of the data line DLm to be the second reference voltage Vr2 different from the first reference voltage Vr1 during the second interval after the first interval and before furnishing the second pixel voltage VPn+1_m to the second pixel Pn+1_;
Step S880: retaining the voltage of the data line DLm to be around the first pixel voltage VPn_m during the interval after writing the first pixel voltage VPn_m into the first pixel Pn_m and before furnishing the second pixel voltage VPn+1_m to the second pixel Pn+1_; and
Step S890: furnishing the second pixel voltage VPn+1_m to the data line DLm and writing the second pixel voltage VPn+1_m into the second pixel Pn+1_.
As shown in
Summarizing the above, the present invention provides a display apparatus having adaptation-mode data line voltage driving mechanism and pixel voltage driving method thereof for performing adaptive data line voltage setting operation during an intermediate period between pixel voltage writing intervals of two adjacent pixels so as to lower total data line voltage changing amount, thereby reducing data line driving power consumption.
The present invention is by no means limited to the embodiments as described above by referring to the accompanying drawings, which may be modified and altered in a variety of different ways without departing from the scope of the present invention. Thus, it should be understood by those skilled in the art that various modifications, combinations, sub-combinations and alternations might occur depending on design requirements and other factors insofar as they are within the scope of the appended claims or the equivalents thereof.
Claims
1. A pixel voltage driving method for use in a display apparatus having adjacent first and second pixels disposed in different rows, the pixel voltage driving method comprising:
- providing a first pixel voltage and a second pixel voltage to be written into the first and second pixels respectively, wherein the first and second pixel voltages are employed to illustrate a same frame;
- calculating a voltage difference between the first and second pixel voltages, and comparing the voltage difference with a preset value for generating a comparison result; and
- performing a pixel voltage driving operation for writing the second pixel voltage into the second pixel according to the comparison result.
2. The pixel voltage driving method of claim 1, wherein the preset value is a voltage difference between a highest pixel voltage and a lowest pixel voltage.
3. The pixel voltage driving method of claim 1, wherein the preset value is half a voltage difference between a highest pixel voltage and a lowest pixel voltage.
4. The pixel voltage driving method of claim 1, wherein the step of performing the pixel voltage driving operation for writing the second pixel voltage into the second pixel according to the comparison result comprises:
- if the voltage difference being less or not greater than the preset value, retaining a voltage of a data line electrically connected to the first and second pixels in the display apparatus to be around the first pixel voltage during an interval after writing the first pixel voltage into the first pixel and before furnishing the second pixel voltage to the second pixel.
5. The pixel voltage driving method of claim 1, wherein the step of performing the pixel voltage driving operation for writing the second pixel voltage into the second pixel according to the comparison result comprises:
- if the voltage difference being greater or not less than the preset value, setting a voltage of a data line electrically connected to the first and second pixels in the display apparatus to be a reference voltage during an interval after writing the first pixel voltage into the first pixel and before furnishing the second pixel voltage to the second pixel.
6. The pixel voltage driving method of claim 5, wherein the reference voltage is a ground voltage.
7. The pixel voltage driving method of claim 5, wherein the reference voltage is an intermediate voltage between a highest pixel voltage and a lowest pixel voltage.
8. The pixel voltage driving method of claim 1, wherein the step of performing the pixel voltage driving operation for writing the second pixel voltage into the second pixel according to the comparison result comprises:
- if the voltage difference being greater or not less than the preset value, setting a voltage of a data line electrically connected to the first and second pixels in the display apparatus to be a first reference voltage during a first interval after writing the first pixel voltage into the first pixel, and setting the voltage of the data line to be a second reference voltage different from the first reference voltage during a second interval after the first interval and before furnishing the second pixel voltage to the second pixel;
- wherein the first and second reference voltages are two intermediate voltages between a highest pixel voltage and a lowest pixel voltage.
9. The pixel voltage driving method of claim 1, further comprising writing the first pixel voltage into the first pixel, wherein the step of calculating the voltage difference between the first and second pixel voltages, and comparing the voltage difference with the preset value for generating the comparison result is performed prior to writing the first pixel voltage into the first pixel.
10. The pixel voltage driving method of claim 1, further comprising writing the first pixel voltage into the first pixel, wherein the step of calculating the voltage difference between the first and second pixel voltages, and comparing the voltage difference with the preset value for generating the comparison result is performed after writing the first pixel voltage into the first pixel.
11. A display apparatus, comprising:
- a pixel array having adjacent first and second pixels disposed in different rows;
- a data line, electrically connected to the first and second pixels, for transmitting a first pixel voltage and a second pixel voltage to be written into the first and second pixels respectively, wherein the first and second pixel voltages are employed to illustrate a same frame; and
- a data driver, electrically connected to the data line, for generating the first and second pixel voltages based on input image data, the data driver comprising: a voltage analysis unit, for calculating a voltage difference between the first and second pixel voltages, and for comparing the voltage difference with a preset value so as to generate a control signal; and a voltage setting unit, electrically connected to the voltage analysis unit and the data line, for setting a voltage of the data line according to the control signal.
12. The display apparatus of claim 11, wherein if the voltage difference is greater or not less than the preset value, the voltage setting unit is utilized for setting the voltage of the data line to be a reference voltage according to the control signal during an interval after writing the first pixel voltage into the first pixel and before furnishing the second pixel voltage to the data line.
13. The display apparatus of claim 12, wherein the reference voltage is an intermediate voltage between a highest pixel voltage and a lowest pixel voltage.
14. The display apparatus of claim 11, wherein if the voltage difference is greater or not less than the preset value, the voltage setting unit is utilized for setting the voltage of the data line to be a first reference voltage according to the control signal during a first interval after writing the first pixel voltage into the first pixel, and for setting the voltage of the data line to be a second reference voltage different from the first reference voltage according to the control signal during a second interval after the first interval and before furnishing the second pixel voltage to the data line, wherein the first and second reference voltages are two intermediate voltages between a highest pixel voltage and a lowest pixel voltage.
15. The display apparatus of claim 11, wherein if the voltage difference is less or not greater than the preset value, the voltage setting unit is utilized for retaining the voltage of the data line to be around the first pixel voltage according to the control signal during an interval after writing the first pixel voltage into the first pixel and before furnishing the second pixel voltage to the data line.
16. The display apparatus of claim 11, wherein the preset value is a voltage difference between a highest pixel voltage and a lowest pixel voltage.
17. The display apparatus of claim 11, wherein the preset value is half a voltage difference between a highest pixel voltage and a lowest pixel voltage.
18. The display apparatus of claim 11, further comprising:
- a scan driver, electrically connected to the first and second pixels, for providing a first scan signal and a second scan signal for controlling writing operations of the first and second pixels respectively.
19. The display apparatus of claim 11, wherein the voltage analysis unit calculates the voltage difference between the first and second pixel voltages, and compares the voltage difference with the preset value for generating the control signal during an interval prior to writing the first pixel voltage into the first pixel.
20. A pixel voltage driving method for use in a display apparatus having adjacent first and second pixels disposed indifferent rows, the pixel voltage driving method comprising:
- providing a first pixel voltage and a second pixel voltage to be written into the first and second pixels respectively, wherein the first and second pixel voltages are employed to illustrate a same frame;
- performing a pixel voltage driving operation for writing the second pixel voltage into the second pixel when a voltage difference between the first and second pixel voltages is smaller than a preset value.
Type: Application
Filed: May 2, 2012
Publication Date: Feb 28, 2013
Inventors: Huan-Hsin Li (Hsin-Chu), Yu-Jen Chen (Hsin-Chu), De-Zhang Peng (Hsin-Chu), Chi-Fu Tsao (Hsin-Chu)
Application Number: 13/462,779