Source driver and operating method thereof

1. Field of the Invention

The invention relates to a display; in particular, to a source driver applied to a display and an operating method thereof.

2. Description of the Prior Art

In general, most current liquid crystal displays use a driving method of column inversion cooperated with the panel structure design, so that even the output polarity of the source driver is column inversion, it looks like dot inversion on the panel.

As to the panel structure design, the Zigzag structure and the Pixel 3-5 (HSD2) structure are usually used in current liquid crystal panels. In addition, the output polarity inversion methods used in the output channels of the source driver can be 1V inversion, 2V inversion and (2V+1) inversion.

However, since there is no effective power saving method used for the current panel structure cooperated with the output way of the source driver, it is hard to reduce the power consumption of the liquid crystal display.

Therefore, the invention provides a source driver and an operating method thereof to solve the above-mentioned problems of the prior arts.

A preferred embodiment of the invention is a source driver. In this embodiment, the source driver includes output channels, a selection unit and a switching unit. The output channels are coupled to a panel. The output channels include M sets of output channels and each set of output channels includes 6N output channels. M and N are positive integers. The selection unit is used to select a lowest power consumption charge-sharing way from the charge-sharing ways corresponding to the 6N output channels with a timing controller algorithm. The switching unit is coupled to the selection unit and the 6N output channels and used to correspondingly switch the coupling relationships of the 6N output channels according to the lowest power consumption charge-sharing way. The lowest power consumption charge-sharing way is to randomly select K output channels from the 6N output channels to perform charge sharing, wherein K=0˜6N.

In an embodiment, when N=1, the 6N output channels includes a first output channel, a second output channel, a third output channel, a fourth output channel, a fifth output channel and a sixth output channel. K=0˜6. The charge-sharing ways include: (a) when K=0, no charge sharing is performed in the first output channel˜the sixth output channel; (b) when K=1, one output channel is randomly selected from the first output channel˜the sixth output channel to perform charge sharing; (c) when K=2, two output channels are randomly selected from the first output channel˜the sixth output channel to perform charge sharing; (d) when K=3, three output channels are randomly selected from the first output channel˜the sixth output channel to perform charge sharing; (e) when K=4, four output channels are randomly selected from the first output channel˜the sixth output channel to perform charge sharing; (f) when K=5, five output channels are randomly selected from the first output channel˜the sixth output channel to perform charge sharing; (g) when K=6, charge sharing is performed in all of the first output channel˜the sixth output channel.

In an embodiment, when N=2, the 6N output channels includes a first output channel, a second output channel, a third output channel, a fourth output channel, a fifth output channel, a sixth output channel, a seventh output channel, an eighth output channel, a ninth output channel, a tenth output channel, an eleventh output channel and a twelfth output channel. K=0˜12. The charge-sharing ways include: (a) when K=0, no charge sharing is performed in the first output channel˜the twelfth output channel; (b) when K=1, one output channel is randomly selected from the first output channel˜the twelfth output channel to perform charge sharing; (c) when K=2, two output channels are randomly selected from the first output channel˜the twelfth output channel to perform charge sharing; (d) when K=3, three output channels are randomly selected from the first output channel˜the twelfth output channel to perform charge sharing; (e) when K=4, four output channels are randomly selected from the first output channel˜the twelfth output channel to perform charge sharing; (f) when K=5, five output channels are randomly selected from the first output channel˜the twelfth output channel to perform charge sharing; (g) when K=6, six output channels are randomly selected from the first output channel˜the twelfth output channel to perform charge sharing; (h) when K=7, seven output channels are randomly selected from the first output channel˜the twelfth output channel to perform charge sharing; (i) when K=8, eight output channels are randomly selected from the first output channel˜the twelfth output channel to perform charge sharing; (j) when K=9, nine output channels are randomly selected from the first output channel˜the twelfth output channel to perform charge sharing; (k) when K=10, ten output channels are randomly selected from the first output channel˜the twelfth output channel to perform charge sharing; (l) when K=11, eleven output channels are randomly selected from the first output channel˜the twelfth output channel to perform charge sharing; (m) when K=12, charge sharing is performed in all of the first output channel˜the twelfth output channel.

In an embodiment, each output channel of the output channels includes an operational amplifier, a first switch and a second switch. An input terminal and an output terminal of the operational amplifier are coupled. The first switch and the second switch are coupled to the output terminal of the operational amplifier respectively and the operation of the first switch and the second switch are controlled by the switching unit. The switching unit correspondingly controls the first switch and the second switch to be conducted or not according to the lowest power consumption charge-sharing way. The first switch and the second switch are not conducted at the same time.

In an embodiment, each output channel of the output channels includes an operational amplifier, a first switch, a second switch and a third switch. An input terminal and an output terminal of the operational amplifier are coupled. The first switch, the second switch and the third switch are coupled to the output terminal of the operational amplifier respectively and the operation of the first switch, the second switch and the third switch are controlled by the switching unit. The switching unit correspondingly controls the first switch, the second switch and the third switch to be conducted or not according to the lowest power consumption charge-sharing way.

Another preferred embodiment of the invention is a source driver operating method. In this embodiment, the source driver operating method is used to operate the source driver including output channels coupled to a panel. The output channels include M sets of output channels and each set of output channels includes 6N output channels. M and N are positive integers. The source driver operating method includes following steps: selecting a lowest power consumption charge-sharing way from the charge-sharing ways corresponding to the 6N output channels with a timing controller algorithm; and correspondingly switching the coupling relationships of the 6N output channels according to the lowest power consumption charge-sharing way. The lowest power consumption charge-sharing way is to randomly select K output channels from the 6N output channels to perform charge sharing, wherein K=0˜6N.

Compared to the prior art, the source driver and operating method thereof in the invention cooperated with the timing controller algorithm to select a lowest power consumption charge-sharing way and corresponding switch the coupling relationships of the output channels of the source driver; therefore, no matter what the panel structure and the output polarity inversion method of the output channels of the source driver are, the source driver and operating method thereof in the invention can realize the charge sharing with the lowest power consumption to reduce power consumption of the liquid crystal display.

The advantage and spirit of the invention may be understood by the following detailed descriptions together with the appended drawings.

FIG. 1 illustrates a schematic diagram of the source driver in an embodiment of the invention.

FIG. 2 illustrates a schematic diagram of the output channels of the source driver in FIG. 1 being divided into M sets of output channels and each set of output channels including 6N output channels.

FIG. 3 illustrates a schematic diagram of the source driver including the first output channel CH 1 ˜the sixth output channel CH 6 in an embodiment (M=1, N=1).

FIG. 4 illustrates a schematic diagram of the source driver including the first output channel CH 1 ˜the twelfth output channel CH 12 in an embodiment (M=1, N=2).

FIG. 5A and FIG. 5B illustrate schematic diagrams of the voltage levels of the data signals outputted by the first output channel CH 1 ˜the twelfth output channel CH 12 of the source driver using the output polarity inversion method of (2V+1) inversion when the panel with Zigzag structure displays a single color (e.g., red).

FIG. 6A illustrates a schematic diagram of using the lowest power consumption charge-sharing way to perform charge sharing to reduce power consumption when the data signal is transmitted from the first data line L 1 of the panel to the second data line L 2 .

FIG. 6B illustrates a schematic diagram of using the lowest power consumption charge-sharing way to perform charge sharing to reduce power consumption when the data signal is transmitted from the second data line L 2 of the panel to the third data line L 3 .

FIG. 7 illustrates a schematic diagram of the voltage levels of the data signals outputted by the first output channel CH 1 ˜the sixth output channel CH 6 of the source driver using the output polarity inversion method of iv inversion when the panel with Pixel 2-5 structure displays a single color (e.g., red).

FIG. 8A illustrates a schematic diagram of using the lowest power consumption charge-sharing way to perform charge sharing to reduce power consumption when the data signal is transmitted from the second data line L 2 of the panel to the third data line L 3 .

FIG. 8B illustrates a schematic diagram of using the lowest power consumption charge-sharing way to perform charge sharing to reduce power consumption when the data signal is transmitted from the fourth data line L 4 of the panel to the fifth data line L 5 .

FIG. 9A illustrates a schematic diagram of each output channel of the first output channel CH 1 ˜the sixth output channel CH 6 of the source driver including an operational amplifier, a first switch and a second switch.

FIG. 9B illustrates a schematic diagram of each output channel of the first output channel CH 1 ˜the sixth output channel CH 6 of the source driver including an operational amplifier, a first switch, a second switch and a third switch.

FIG. 10 illustrates a flowchart of the source driver operating method in another embodiment of the invention.

A preferred embodiment of the invention is a source driver. In this embodiment, the source driver is applied to a liquid crystal display and coupled to a panel through its output channels.

In practical applications, the panel can have Zigzag structure or Pixel 3-5 (HSD2) structure, but not limited to this; the output polarity inversion method can be 1V inversion, 2V inversion or (2V+1) inversion, but not limited to this.

Please refer to FIG. 1 . FIG. 1 illustrates a schematic diagram of the source driver in this embodiment. As shown in FIG. 1 , in a display 1 , a source driver 12 is coupled between a timing controller 10 and a panel 14 . The source driver 12 includes a selection unit 120 , a switching unit 122 and a plurality of output channels CH 1 ˜CH(6NM). Wherein, N and M are positive integers. The selection unit 120 is coupled to the timing controller 10 ; the switching unit 122 is coupled to the selection unit 120 and the plurality of output channels CH 1 ˜CH(6NM); the plurality of output channels CH 1 ˜CH(6NM) is coupled to the panel 14 .

It should be noticed that the plurality of output channels CH 1 ˜CH(6NM) of the source driver 12 in FIG. 1 can be divided into M sets of output channels and each set of output channels includes 6N output channels, wherein M and N are positive integers. That is to say, as shown in FIG. 2 , if the 6NM output channels CH 1 ˜CH(6NM) are divided into M sets of output channels, then a first set of output channels will include the output channels CH 1 ˜CH(6N), a second set of output channels will include the output channels CH(6N+1)˜CH(12N), . . . , a M-th set of output channels will include the output channels CH(6NM−6N+1)˜CH(6NM).

For example, as shown in FIG. 3 , if M=1 and N=1, then the source driver 12 includes a first output channel CH 1 , a second output channel CH 2 , a third output channel CH 3 , a fourth output channel CH 4 , a fifth output channel CH 5 and a sixth output channel CH 6 ; as shown in FIG. 4 , if M=1 and N=2, then the source driver 12 includes a first output channel CH 1 , a second output channel CH 2 , a third output channel CH 3 , a fourth output channel CH 4 , a fifth output channel CH 5 , a sixth output channel CH 6 , a seventh output channel CH 7 , an eighth output channel CH 8 , a ninth output channel CH 9 , a tenth output channel CH 10 , an eleventh output channel CH 11 and a twelfth output channel CH 12 . The rest can be deduced by analogy and will not be described here.

In this embodiment, the selection unit 120 can select a lowest power consumption charge-sharing way from a plurality of charge-sharing ways corresponding to the 6N output channels cooperated with an algorithm of the timing controller 10 . That is to say, the selection unit 120 selects a charge-sharing way consuming the least energy (the lowest power consumption) from the plurality of charge-sharing ways cooperated with the algorithm of the timing controller 10 . And then, the switching unit 122 correspondingly switches the coupling relationships of the 6N output channels according to the lowest power consumption charge-sharing way.

In practical applications, the lowest power consumption charge-sharing way is to randomly select K output channels from the 6N output channels to perform charge sharing, wherein K=0˜6N.

Taking FIG. 3 for example, the source driver 12 includes the first output channel CH 1 , the second output channel CH 2 , the third output channel CH 3 , the fourth output channel CH 4 , the fifth output channel CH 5 and the sixth output channel CH 6 . Therefore, there will be 7 charge sharing ways corresponding to K=0˜6 among the first output channel CH 1 ˜the sixth output channel CH 6 as follows:

(a) when K=0, no charge sharing is performed in the first output channel˜the sixth output channel;

(b) when K=1, one output channel is randomly selected from the first output channel˜the sixth output channel to perform charge sharing;

(c) when K=2, two output channels are randomly selected from the first output channel˜the sixth output channel to perform charge sharing;

(d) when K=3, three output channels are randomly selected from the first output channel˜the sixth output channel to perform charge sharing;

(e) when K=4, four output channels are randomly selected from the first output channel˜the sixth output channel to perform charge sharing;

(f) when K=5, five output channels are randomly selected from the first output channel˜the sixth output channel to perform charge sharing;

(g) when K=6, charge sharing is performed in all of the first output channel˜the sixth output channel.

If the selection unit 120 selects the charge-sharing way (c) from the seven charge-sharing ways (a)˜(g) as the lowest power consumption charge-sharing way, that is to say, the selection unit 120 determines that the charge-sharing way (c) consuming the least energy (the lowest power consumption) among the seven charge-sharing ways (a)˜(g) cooperated with the algorithm of the timing controller 10 , and then the switching unit 122 will correspondingly switch the coupling relationships of the first output channel˜the sixth output channel according to the lowest power consumption charge-sharing way (c) to randomly select two output channels from the first output channel˜the sixth output channel to perform charge sharing, so that the power consumption can be effectively reduced. The rest can be deduced by analogy and will not be described here.

Taking FIG. 4 for example, the source driver 12 includes a first output channel CH 1 , a second output channel CH 2 , a third output channel CH 3 , a fourth output channel CH 4 , a fifth output channel CH 5 and a sixth output channel CH 6 ; as shown in FIG. 4 , if M=1 and N=2, then the source driver 12 includes a first output channel CH 1 , a second output channel CH 2 , a third output channel CH 3 , a fourth output channel CH 4 , a fifth output channel CH 5 , a sixth output channel CH 6 , a seventh output channel CH 7 , an eighth output channel CH 8 , a ninth output channel CH 9 , a tenth output channel CH 10 , an eleventh output channel CH 11 and a twelfth output channel CH 12 . Therefore, there will be 13 charge sharing ways corresponding to K=0˜12 among the first output channel CH 1 ˜the twelfth output channel CH 12 as follows:

(a) when K=0, no charge sharing is performed in the first output channel˜the twelfth output channel;

(b) when K=1, one output channel is randomly selected from the first output channel˜the twelfth output channel to perform charge sharing;

(c) when K=2, two output channels are randomly selected from the first output channel˜the twelfth output channel to perform charge sharing;

(d) when K=3, three output channels are randomly selected from the first output channel˜the twelfth output channel to perform charge sharing;

(e) when K=4, four output channels are randomly selected from the first output channel˜the twelfth output channel to perform charge sharing;

(f) when K=5, five output channels are randomly selected from the first output channel˜the twelfth output channel to perform charge sharing;

(g) when K=6, six output channels are randomly selected from the first output channel˜the twelfth output channel to perform charge sharing;

(h) when K=7, seven output channels are randomly selected from the first output channel˜the twelfth output channel to perform charge sharing;

(i) when K=8, eight output channels are randomly selected from the first output channel˜the twelfth output channel to perform charge sharing;

(j) when K=9, nine output channels are randomly selected from the first output channel˜the twelfth output channel to perform charge sharing;

(k) when K=10, ten output channels are randomly selected from the first output channel˜the twelfth output channel to perform charge sharing;

(l) when K=11, eleven output channels are randomly selected from the first output channel˜the twelfth output channel to perform charge sharing;

(m) when K=12, charge sharing is performed in all of the first output channel˜the twelfth output channel.

If the selection unit 120 selects the charge-sharing way (d) from the thirteen charge-sharing ways (a)˜(m) as the lowest power consumption charge-sharing way, that is to say, the selection unit 120 determines that the charge-sharing way (d) consuming the least energy (the lowest power consumption) among the thirteen charge-sharing ways (a)˜(m) cooperated with the algorithm of the timing controller 10 , and then the switching unit 122 will correspondingly switch the coupling relationships of the first output channel˜the twelfth output channel according to the lowest power consumption charge-sharing way (d) to randomly select three output channels from the first output channel˜the twelfth output channel to perform charge sharing, so that the power consumption can be effectively reduced. The rest can be deduced by analogy and will not be described here.

Then, please refer to FIG. 5A and FIG. 5B . FIG. 5A and FIG. 5B illustrate schematic diagrams of the voltage levels of the data signals outputted by the first output channel CH 1 ˜the twelfth output channel CH 12 of the source driver 12 using the output polarity inversion method of (2V+1) inversion when the panel 14 with Zigzag structure displays a single color (e.g., red).

As shown in FIG. 5A and FIG. 5B , since the first output channel CH 1 ˜the twelfth output channel CH 12 of the source driver 12 use the output polarity inversion method of (2V+1) inversion, the output polarities of the first output channel CH 1 , the second output channel CH 2 , the third output channel CH 3 , the fourth output channel CH 4 , the fifth output channel CH 5 , the sixth output channel CH 6 , the seventh output channel CH 7 , the eighth output channel CH 8 , the ninth output channel CH 9 , the tenth output channel CH 10 , the eleventh output channel CH 11 and the twelfth output channel CH 12 are positive (+), negative (−), negative (−), positive (+), positive (+), negative (−), negative (−), positive (+), positive (+), negative (−), negative (−) and positive (+) in order.

As shown in FIG. 5A and FIG. 5B , when the output polarity of the output channels is positive (+), the voltage levels of the data signals outputted by the output channels are all higher than the common voltage VCOM; on the contrary, when the output polarity of the output channels is negative (−), the voltage levels of the data signals outputted by the output channels are all lower than the common voltage VCOM.

Please refer to FIG. 5A , FIG. 5B and the first output channel CH 1 ˜the twelfth output channel CH 12 without charge sharing shown in the left-side of FIG. 6A . As to the first output channel CH 1 , when the positive (+) data signal outputted by the first output channel CH 1 is transmitted from a first data line L 1 of the panel to a second data line L 2 , the positive (+) data signal is changed from high-level to low-level.

As to the second output channel CH 2 , when the negative (−) data signal outputted by the second output channel CH 2 is transmitted from the first data line L 1 of the panel to the second data line L 2 , the negative (−) data signal is changed from high-level to low-level.

As to the third output channel CH 3 , when the negative (−) data signal outputted by the third output channel CH 3 is transmitted from the first data line L 1 of the panel to the second data line L 2 , the negative (−) data signal is maintained at high-level.

As to the fourth output channel CH 4 , when the positive (+) data signal outputted by the fourth output channel CH 4 is transmitted from the first data line L 1 of the panel to the second data line L 2 , the positive (+) data signal is changed from high-level to low-level.

As to the fifth output channel CH 5 , when the positive (+) data signal outputted by the fifth output channel CH 5 is transmitted from the first data line L 1 of the panel to the second data line L 2 , the positive (+) data signal is changed from low-level to high-level. It should be noticed that the fifth channel CH 5 needs to consume energy (power consumption) Q at this time.

As to the sixth output channel CH 6 , when the negative (−) data signal outputted by the sixth output channel CH 6 is transmitted from the first data line L 1 of the panel to the second data line L 2 , the negative (−) data signal is maintained at high-level.

As to the seventh output channel CH 7 , when the negative (−) data signal outputted by the seventh output channel CH 7 is transmitted from the first data line L 1 of the panel to the second data line L 2 , the negative (−) data signal is changed from low-level to high-level. It should be noticed that the seventh channel CH 7 needs to consume energy (power consumption) Q at this time.

As to the eighth output channel CH 8 , when the positive (+) data signal outputted by the eighth output channel CH 8 is transmitted from the first data line L 1 of the panel to the second data line L 2 , the positive (+) data signal is changed from low-level to high-level. It should be noticed that the eighth channel CH 8 needs to consume energy (power consumption) Q at this time.

As to the ninth output channel CH 9 , when the positive (+) data signal outputted by the ninth output channel CH 9 is transmitted from the first data line L 1 of the panel to the second data line L 2 , the positive (+) data signal is maintained at low-level.

As to the tenth output channel CH 10 , when the negative (−) data signal outputted by the tenth output channel CH 10 is transmitted from the first data line L 1 of the panel to the second data line L 2 , the negative (−) data signal is changed from low-level to high-level. It should be noticed that the tenth channel CH 10 needs to consume energy (power consumption) Q at this time.

As to the eleventh output channel CH 11 , when the negative (−) data signal outputted by the eleventh output channel CH 11 is transmitted from the first data line L 1 of the panel to the second data line L 2 , the negative (−) data signal is changed from high-level to low-level.

As to the twelfth output channel CH 12 , when the positive (+) data signal outputted by the twelfth output channel CH 12 is transmitted from the first data line L 1 of the panel to the second data line L 2 , the positive (+) data signal is maintained at low-level.

Above all, if no charge sharing is performed in the first output channel CH 1 ˜the twelfth output channel CH 12 , total energy consumed (power consumption) is 4Q when the data signals outputted by the first output channel CH 1 ˜the twelfth output channel CH 12 are transmitted from the first data line L 1 of the panel to the second data line L 2 .

When the data signals are transmitted from the first data line L 1 of the panel to the second data line L 2 , as shown in the right-side of the FIG. 6A , the lowest power consumption charge-sharing way selected by the selection unit 120 of the invention from all charge-sharing ways can be: performing charge sharing on the first output channel CH 1 of positive (+) output and the seventh output channel CH 7 of negative output (−) and performing charge sharing on the fourth output channel CH 4 of positive (+) output and the tenth output channel CH 10 of negative output (−). Therefore, the switching unit 122 will correspondingly switch the first output channel CH 1 and the seventh output channel CH 7 to be coupled and switch the fourth output channel CH 4 and the tenth output channel CH 10 to be coupled according to the lowest power consumption charge-sharing way.

Since the first output channel CH 1 is changed from high-level to low-level and the seventh output channel CH 7 is changed from low-level to high-level, when they are coupled to perform charge sharing, the voltage changes of the first output channel CH 1 and the seventh output channel CH 7 will be compensated without power consumption. Similarly, Since the fourth output channel CH 4 is changed from high-level to low-level and the tenth output channel CH 10 is changed from low-level to high-level, when they are coupled to perform charge sharing, the voltage changes of the fourth output channel CH 4 and the tenth output channel CH 10 will be compensated without power consumption. Therefore, the total energy consumed (power consumption) is 2Q including the energy consumed by the fifth output channel CH 5 and the eighth output channel CH 8 when the data signals outputted by the first output channel CH 1 ˜the twelfth output channel CH 12 are transmitted from the first data line L 1 of the panel to the second data line L 2 . That is to say, using the lowest power consumption charge-sharing way can effectively reduce 50% power consumption.

Similarly, please refer to FIG. 5A , FIG. 5B and the first output channel CH 1 ˜the twelfth output channel CH 12 without charge sharing shown in the left-side of FIG. 6B . As to the first output channel CH 1 , when the positive (+) data signal outputted by the first output channel CH 1 is transmitted from a second data line L 2 of the panel to a third data line L 3 , the positive (+) data signal is changed from low-level to high-level. It should be noticed that the first channel CH 1 needs to consume energy (power consumption) Q at this time.

As to the second output channel CH 2 , when the negative (−) data signal outputted by the second output channel CH 2 is transmitted from the second data line L 2 of the panel to the third data line L 3 , the negative (−) data signal is changed from low-level to high-level. It should be noticed that the second channel CH 2 needs to consume energy (power consumption) Q at this time.

As to the third output channel CH 3 , when the negative (−) data signal outputted by the third output channel CH 3 is transmitted from the second data line L 2 of the panel to the third data line L 3 , the negative (−) data signal is maintained at high-level.

As to the fourth output channel CH 4 , when the positive (+) data signal outputted by the fourth output channel CH 4 is transmitted from the second data line L 2 of the panel to the third data line L 3 , the positive (+) data signal is changed from low-level to high-level. It should be noticed that the fourth output channel CH 4 needs to consume energy (power consumption) Q at this time.

As to the fifth output channel CH 5 , when the positive (+) data signal outputted by the fifth output channel CH 5 is transmitted from the second data line L 2 of the panel to the third data line L 3 , the positive (+) data signal is changed from high-level to low-level.

As to the sixth output channel CH 6 , when the negative (−) data signal outputted by the sixth output channel CH 6 is transmitted from the second data line L 2 of the panel to the third data line L 3 , the negative (−) data signal is maintained at high-level.

As to the seventh output channel CH 7 , when the negative (−) data signal outputted by the seventh output channel CH 7 is transmitted from the second data line L 2 of the panel to the third data line L 3 , the negative (−) data signal is changed from high-level to low-level.

As to the eighth output channel CH 8 , when the positive (+) data signal outputted by the eighth output channel CH 8 is transmitted from the second data line L 2 of the panel to the third data line L 3 , the positive (+) data signal is changed from high-level to low-level.

As to the ninth output channel CH 9 , when the positive (+) data signal outputted by the ninth output channel CH 9 is transmitted from the second data line L 2 of the panel to the third data line L 3 , the positive (+) data signal is maintained at low-level.

As to the tenth output channel CH 10 , when the negative (−) data signal outputted by the tenth output channel CH 10 is transmitted from the second data line L 2 of the panel to the third data line L 3 , the negative (−) data signal is changed from high-level to low-level.

As to the eleventh output channel CH 11 , when the negative (−) data signal outputted by the eleventh output channel CH 11 is transmitted from the second data line L 2 of the panel to the third data line L 3 , the negative (−) data signal is changed from low-level to high-level. It should be noticed that the eleventh output channel CH 11 needs to consume energy (power consumption) Q at this time.

As to the twelfth output channel CH 12 , when the positive (+) data signal outputted by the twelfth output channel CH 12 is transmitted from the second data line L 2 of the panel to the third data line L 3 , the positive (+) data signal is maintained at low-level.

Above all, if no charge sharing is performed in the first output channel CH 1 ˜the twelfth output channel CH 12 , total energy consumed (power consumption) is 4Q when the data signals outputted by the first output channel CH 1 ˜the twelfth output channel CH 12 are transmitted from the second data line L 2 of the panel to the third data line L 3 .

When the data signals are transmitted from the second data line L 2 of the panel to the third data line L 3 , as shown in the right-side of the FIG. 6B , the lowest power consumption charge-sharing way selected by the selection unit 120 of the invention from all charge-sharing ways can be: performing charge sharing on the fifth output channel CH 5 of positive (+) output and the second output channel CH 2 of negative output (−) and performing charge sharing on the eighth output channel CH 8 of positive (+) output and the eleventh output channel CH 11 of negative output (−). Therefore, the switching unit 122 will correspondingly switch the fifth output channel CH 5 and the second output channel CH 2 to be coupled and switch the eighth output channel CH 8 and the eleventh output channel CH 11 to be coupled according to the lowest power consumption charge-sharing way.

Since the fifth output channel CH 5 is changed from high-level to low-level and the second output channel CH 2 is changed from low-level to high-level, when they are coupled to perform charge sharing, the voltage changes of the fifth output channel CH 5 and the second output channel CH 2 will be compensated without power consumption. Similarly, since the eighth output channel CH 8 is changed from high-level to low-level and the eleventh output channel CH 11 is changed from low-level to high-level, when they are coupled to perform charge sharing, the voltage changes of the eighth output channel CH 8 and the eleventh output channel CH 11 will be compensated without power consumption. Therefore, the total energy consumed (power consumption) is 2Q including the energy consumed by the first output channel CH 1 and the fourth output channel CH 4 when the data signals outputted by the first output channel CH 1 ˜the twelfth output channel CH 12 are transmitted from the second data line L 2 of the panel to the third data line L 3 . That is to say, using the lowest power consumption charge-sharing way can effectively reduce 50% power consumption.

It should be noticed that the lowest power consumption charge-sharing way selected by the selection unit 120 cooperated with the timing controller 10 is not limited by the above-mentioned embodiments.

In another embodiment, please refer to FIG. 7 . FIG. 7 illustrates a schematic diagram of the voltage levels of the data signals outputted by the first output channel CH 1 ˜the sixth output channel CH 6 of the source driver 12 using the output polarity inversion method of 1V inversion when the panel 14 with Pixel 2-5 structure displays a single color (e.g., red).

As shown in FIG. 7 , since the first output channel CH 1 ˜the sixth output channel CH 6 of the source driver 12 use the output polarity inversion method of 1V inversion, the output polarities of the first output channel CH 1 , the second output channel CH 2 , the third output channel CH 3 , the fourth output channel CH 4 , the fifth output channel CH 5 and the sixth output channel CH 6 are positive (+), negative (−), positive (+), negative (−), positive (+) and negative (−) in order.

As shown in FIG. 7 , when the output polarity of the output channels is positive (+), the voltage levels of the data signals outputted by the output channels are all higher than the common voltage VCOM; on the contrary, when the output polarity of the output channels is negative (−), the voltage levels of the data signals outputted by the output channels are all lower than the common voltage VCOM.

It should be noticed that L 1 →L 2 in FIG. 7 represents that the data signal is transmitted from the first data line L 1 to the second data line L 2 , L 2 →L 3 in FIG. 7 represents that the data signal is transmitted from the second data line L 2 to the third data line L 3 , L 3 →L 4 in FIG. 7 represents that the data signal is transmitted from the third data line L 3 to the fourth data line L 4 , and L 4 →L 5 in FIG. 7 represents that the data signal is transmitted from the fourth data line L 4 to the fifth data line L 5 , wherein examples of L 2 →L 3 and L 4 →L 5 will be introduced as follows and so on.

Please refer to FIG. 7 and the first output channel CH 1 ˜the sixth output channel CH 6 without charge sharing shown in the left-side of FIG. 8A . As to the first output channel CH 1 , when the positive (+) data signal outputted by the first output channel CH 1 is transmitted from the second data line L 2 of the panel to the third data line L 3 , the positive (+) data signal is changed from high-level to low-level.

As to the second output channel CH 2 , when the negative (−) data signal outputted by the second output channel CH 2 is transmitted from the second data line L 2 of the panel to the third data line L 3 , the negative (−) data signal is maintained at high-level.

As to the third output channel CH 3 , when the positive (+) data signal outputted by the third output channel CH 3 is transmitted from the second data line L 2 of the panel to the third data line L 3 , the positive (+) data signal is changed from high-level to low-level.

As to the fourth output channel CH 4 , when the negative (−) data signal outputted by the fourth output channel CH 4 is transmitted from the second data line L 2 of the panel to the third data line L 3 , the negative (−) data signal is changed from low-level to high-level. It should be noticed that the fourth output channel CH 4 needs to consume energy (power consumption) Q at this time.

As to the fifth output channel CH 5 , when the positive (+) data signal outputted by the fifth output channel CH 5 is transmitted from the second data line L 2 of the panel to the third data line L 3 , the positive (+) data signal is maintained at low-level.

As to the sixth output channel CH 6 , when the negative (−) data signal outputted by the sixth output channel CH 6 is transmitted from the second data line L 2 of the panel to the third data line L 3 , the negative (−) data signal is changed from low-level to high-level. It should be noticed that the sixth output channel CH 6 needs to consume energy (power consumption) Q at this time.

Above all, if no charge sharing is performed in the first output channel CH 1 ˜the sixth output channel CH 6 , total energy consumed (power consumption) is 2Q when the data signals outputted by the first output channel CH 1 ˜the sixth output channel CH 6 are transmitted from the second data line L 2 of the panel to the third data line L 3 .

When the data signals are transmitted from the second data line L 2 of the panel to the third data line L 3 , as shown in the right-side of the FIG. 8A , the lowest power consumption charge-sharing way selected by the selection unit 120 of the invention from all charge-sharing ways can be: performing charge sharing on the first output channel CH 1 of positive (+) output and the fourth output channel CH 4 of negative output (−) and performing charge sharing on the third output channel CH 3 of positive (+) output and the sixth output channel CH 6 of negative output (−). Therefore, the switching unit 122 will correspondingly switch the first output channel CH 1 and the fourth output channel CH 4 to be coupled and switch the third output channel CH 3 and the sixth output channel CH 6 to be coupled according to the lowest power consumption charge-sharing way.

Since the first output channel CH 1 is changed from high-level to low-level and the fourth output channel CH 4 is changed from low-level to high-level, when they are coupled to perform charge sharing, the voltage changes of the first output channel CH 1 and the fourth output channel CH 4 will be compensated without power consumption. Similarly, since the third output channel CH 3 is changed from high-level to low-level and the sixth output channel CH 6 is changed from low-level to high-level, when they are coupled to perform charge sharing, the voltage changes of the third output channel CH 3 and the sixth output channel CH 6 will be compensated without power consumption. Therefore, the total energy consumed (power consumption) is zero when the data signals outputted by the first output channel CH 1 ˜the sixth output channel CH 6 are transmitted from the second data line L 2 of the panel to the third data line L 3 . That is to say, using the lowest power consumption charge-sharing way can effectively reduce power consumption.

Similarly, please refer to FIG. 7 and the first output channel CH 1 ˜the sixth output channel CH 6 without charge sharing shown in the left-side of FIG. 8B . As to the first output channel CH 1 , when the positive (+) data signal outputted by the first output channel CH 1 is transmitted from the fourth data line L 4 of the panel to the fifth data line L 5 , the positive (+) data signal is maintained at low-level.

As to the second output channel CH 2 , when the negative (−) data signal outputted by the second output channel CH 2 is transmitted from the fourth data line L 4 of the panel to the fifth data line L 5 , the negative (−) data signal is changed from low-level to high-level. It should be noticed that the second output channel CH 2 needs to consume energy (power consumption) Q at this time.

As to the third output channel CH 3 , when the positive (+) data signal outputted by the third output channel CH 3 is transmitted from the fourth data line L 4 of the panel to the fifth data line L 5 , the positive (+) data signal is changed from high-level to low-level.

As to the fourth output channel CH 4 , when the negative (−) data signal outputted by the fourth output channel CH 4 is transmitted from the fourth data line L 4 of the panel to the fifth data line L 5 , the negative (−) data signal is maintained at high-level.

As to the fifth output channel CH 5 , when the positive (+) data signal outputted by the fifth output channel CH 5 is transmitted from the fourth data line L 4 of the panel to the fifth data line L 5 , the positive (+) data signal is changed from high-level to low-level.

As to the sixth output channel CH 6 , when the negative (−) data signal outputted by the sixth output channel CH 6 is transmitted from the fourth data line L 4 of the panel to the fifth data line L 5 , the negative (−) data signal is changed from low-level to high-level. It should be noticed that the sixth output channel CH 6 needs to consume energy (power consumption) Q at this time.

Above all, if no charge sharing is performed in the first output channel CH 1 ˜the sixth output channel CH 6 , total energy consumed (power consumption) is 2Q when the data signals outputted by the first output channel CH 1 ˜the sixth output channel CH 6 are transmitted from the fourth data line L 4 of the panel to the fifth data line L 5 .

When the data signals are transmitted from the fourth data line L 4 of the panel to the fifth data line L 5 , as shown in the right-side of the FIG. 8B , the lowest power consumption charge-sharing way selected by the selection unit 120 of the invention from all charge-sharing ways can be: performing charge sharing on the third output channel CH 3 of positive (+) output and the second output channel CH 2 of negative output (−) and performing charge sharing on the fifth output channel CH 5 of positive (+) output and the sixth output channel CH 6 of negative output (−). Therefore, the switching unit 122 will correspondingly switch the third output channel CH 3 and the second output channel CH 2 to be coupled and switch the fifth output channel CH 5 and the sixth output channel CH 6 to be coupled according to the lowest power consumption charge-sharing way.

Since the third output channel CH 3 is changed from high-level to low-level and the second output channel CH 2 is changed from low-level to high-level, when they are coupled to perform charge sharing, the voltage changes of the third output channel CH 3 and the second output channel CH 2 will be compensated without power consumption. Similarly, since the fifth output channel CH 5 is changed from high-level to low-level and the sixth output channel CH 6 is changed from low-level to high-level, when they are coupled to perform charge sharing, the voltage changes of the fifth output channel CH 5 and the sixth output channel CH 6 will be compensated without power consumption. Therefore, the total energy consumed (power consumption) is zero when the data signals outputted by the first output channel CH 1 ˜the sixth output channel CH 6 are transmitted from the fourth data line L 4 of the panel to the fifth data line L 5 . That is to say, using the lowest power consumption charge-sharing way can effectively reduce power consumption.

Next, please refer to FIG. 9A . As shown in FIG. 9A , in an embodiment, as to the first output channel CH 1 ˜the sixth output channel CH 6 of the source driver in FIG. 3 , each of the first output channel CH 1 ˜the sixth output channel CH 6 can include an operational amplifier OP, a first switch SW 1 and a second switch SW 2 . One input terminal and an output terminal of the operational amplifier OP are coupled. The first switch SW 1 and the second switch SW 2 are coupled to the output terminal of the operational amplifier OP respectively. The operation of the first switch SW 1 and the second switch SW 2 are controlled by the switching unit 122 . The switching unit 122 correspondingly controls whether the first switch SW 1 and the second switch SW 2 are conducted or not according to the lowest power consumption charge sharing way. It should be noticed that the first switch SW 1 and the second switch SW 2 are not conducted at the same time.

In addition, as to the first output channel CH 1 ˜the twelfth output channel CH 12 in FIG. 4 , each of the first output channel CH 1 ˜the twelfth output channel CH 12 can also include an operational amplifier OP, a first switch SW 1 and a second switch SW 2 , and so on.

Then, please refer to FIG. 9B . As shown in FIG. 9B , in an embodiment, as to the first output channel CH 1 ˜the sixth output channel CH 6 of the source driver in FIG. 3 , each of the first output channel CH 1 ˜the sixth output channel CH 6 can include an operational amplifier OP, a first switch SW 1 , a second switch SW 2 and a third switch SW 3 . One input terminal and an output terminal of the operational amplifier OP are coupled. The first switch SW 1 , the second switch SW 2 and the third switch SW 3 are coupled to the output terminal of the operational amplifier OP respectively. The operation of the first switch SW 1 , the second switch SW 2 and the third switch SW 3 are controlled by the switching unit 122 . The switching unit 122 correspondingly controls whether the first switch SW 1 , the second switch SW 2 and the third switch SW 3 are conducted or not according to the lowest power consumption charge sharing way.

In addition, as to the first output channel CH 1 ˜the twelfth output channel CH 12 in FIG. 4 , each of the first output channel CH 1 ˜the twelfth output channel CH 12 can also include an operational amplifier OP, a first switch SW 1 , a second switch SW 2 and a third switch SW 3 , and so on.

Another preferred embodiment of the invention is a source driver operating method. In this embodiment, the source driver operating method is used to operate the source driver including output channels coupled to a panel. The output channels include M sets of output channels and each set of output channels includes 6N output channels, wherein M and N are positive integers.

Please refer to FIG. 10 . FIG. 10 illustrates a flowchart of the source driver operating method in this embodiment. As shown in FIG. 10 , the source driver operating method can include following steps:

Step S 10 : selecting a lowest power consumption charge-sharing way from the charge-sharing ways corresponding to the 6N output channels with a timing controller algorithm; and

Step S 12 : correspondingly switching the coupling relationships of the 6N output channels according to the lowest power consumption charge-sharing way. The lowest power consumption charge-sharing way is to randomly select K output channels from the 6N output channels to perform charge sharing, wherein K=0˜6N.

Compared to the prior art, the source driver and operating method thereof in the invention cooperated with the timing controller algorithm to select a lowest power consumption charge-sharing way and corresponding switch the coupling relationships of the output channels of the source driver; therefore, no matter what the panel structure and the output polarity inversion method of the output channels of the source driver are, the source driver and operating method thereof in the invention can realize the charge sharing with the lowest power consumption to reduce power consumption of the liquid crystal display.

With the example and explanations above, the features and spirits of the invention will be hopefully well described. Those skilled in the art will readily observe that numerous modifications and alterations of the device may be made while retaining the teaching of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.