TWI769718B - Power-saving source driver chip and liquid crystal display and information processing device using the same - Google Patents

Abstract

A power-saving source driver chip has: a detection circuit for judging whether the numerical difference of display data of two adjacent rows is greater than a threshold; and a charge sharing control circuit for when the numerical difference is greater than the threshold When driving a switch circuit to perform a charge sharing operation on a TFT liquid crystal array to save power consumption.

Description

Power-saving source driver chip and liquid crystal display and information processing device using the same

The present invention relates to a power-saving source driver chip, in particular to a power-saving source driver chip that can save the power consumption of a liquid crystal display.

In order to save the power consumption of the liquid crystal display, the conventional technical solution of charge sharing is proposed. Please refer to FIG. 1 , which shows a block diagram of a charge sharing control circuit of a conventional liquid crystal display. As shown in FIG. 1 , the charge sharing control circuit includes a timing controller 11 , a polarity change detection unit 12 , a source driver 13 and a TFT liquid crystal array 14 .

The timing controller 11 is used for transmitting a polarity signal _SP to the polarity change detection unit 12, wherein, when the timing controller 11 determines that there is a static partial image according to the display data, it will change the polarity of the polarity signal _SP , so that the polarity of the polarity signal SP is changed. It changes from positive to negative or from negative to positive, so that the pixel voltage is changed from above/below a reference voltage (common voltage) to below/above the reference voltage (common voltage), so as to avoid the liquid crystal of the TFT liquid crystal array 14 Molecules produce elastic fatigue that cannot be restored to its original state.

When the polarity change detection unit 12 detects that the _polarities of the two adjacent polarity signals SP are opposite, a charge sharing enable signal C _CS is in an active state, and the source driver 13 is in the charge sharing enable signal C _CS . In the active state, an internal switch circuit is driven, so as to cause the TFT liquid crystal array 14 to perform charge sharing among its multiple data channels, so as to save the amount of charge required to establish the pixel voltage of the next frame.

However, the charge sharing control circuit in FIG. 1 can only perform charge sharing when the polarity of the pixel voltage is instructed to be changed, and does not perform the charge sharing when the polarity of the pixel voltage is not instructed to be changed. There is still room for improvement in the power saving aspect of the display.

To solve the above problems, a novel source driver chip is urgently needed in the art.

One object of the present invention is to provide a power-saving source driver chip, which can still have a pixel gray level of a row greater than or equal to a first pixel voltage even when the timing controller does not instruct the polarity of the pixel voltage to be changed. A charge sharing operation is performed on a TFT liquid crystal array when the gray level of one pixel in the other row is lower than or equal to a second predetermined gray level.

Another object of the present invention is to provide a liquid crystal display, which can still have a pixel gray level of a row greater than or equal to a first predetermined gray level even when the timing controller does not instruct the polarity of the pixel voltage to be changed. When the gray level of one pixel in the other row is lower than or equal to a second predetermined gray level, a charge sharing operation is performed on a TFT liquid crystal array to save power consumption.

Another object of the present invention is to provide an information processing device, which has the aforementioned liquid crystal display and can save power consumption.

In order to achieve the aforementioned purpose, a power-saving source driver chip is proposed, which has:

a first detection circuit for detecting a row of display data to generate a first detection result, wherein when the highest two bits of the display data in the row of display data are both 1, the first detection The detection result is in an active state, otherwise, the first detection result is in an inactive state;

a register for latching the first detection result according to the control of a clock signal, and providing an output state representing the previous state of the first detection result accordingly;

a second detection circuit for detecting the next line of display data to generate a second detection result, wherein when the highest two bits of the display data in the next line of display data are both 0, the first The second detection result is in an active state, otherwise, the second detection result is in an inactive state; and

A logic gate outputs an enable signal to drive a switch circuit to perform a charge sharing operation on a TFT liquid crystal array when both the output state and the second detection result are in an active state.

In one embodiment, the logic gate is a gate and a gate.

In one embodiment, the logic gate is a NOT-OR gate.

In order to achieve the aforementioned purpose, the present invention further provides a power-saving source driver chip, which has:

a detection circuit for judging whether the numerical difference between the display data of two adjacent rows is greater than a threshold; and

A charge-sharing control circuit is used for driving a switch circuit to perform a charge-sharing operation on a TFT liquid crystal array when the value difference is greater than the threshold.

In order to achieve the aforementioned purpose, the present invention further provides a liquid crystal display, which has a power-saving source driver chip and a TFT liquid crystal array, and the power-saving source driver chip has:

a first detection circuit for detecting a row of display data to generate a first detection result, wherein when the highest two bits of the display data in the row of display data are both 1, the first detection The detection result is in an active state, otherwise, the first detection result is in an inactive state;

a register for latching the first detection result according to the control of a clock signal, and providing an output state representing the previous state of the first detection result accordingly;

a second detection circuit for detecting the next line of display data to generate a second detection result, wherein when the highest two bits of the display data in the next line of display data are both 0, the first The second detection result is in an active state, otherwise, the second detection result is in an inactive state; and

A logic gate outputs an enable signal to drive a switch circuit to perform a charge sharing operation on the TFT liquid crystal array when both the output state and the second detection result are in active states.

In one embodiment, the logic gate is a gate and a gate.

In one embodiment, the logic gate is a NOT-OR gate.

In order to achieve the aforementioned purpose, the present invention further provides a liquid crystal display, which has a power-saving source driver chip and a TFT liquid crystal array, and the power-saving source driver chip has:

a detection circuit for judging whether the numerical difference between the display data of two adjacent rows is greater than a threshold; and

A charge sharing control circuit is used for driving a switch circuit to perform a charge sharing operation on the TFT liquid crystal array when the value difference is greater than the threshold.

In order to achieve the aforementioned object, the present invention further provides an information processing device, which has a central processing unit and a liquid crystal display, wherein the central processing unit is used for communication with the liquid crystal display, and the liquid crystal display has a power saving type A source driver chip and a TFT liquid crystal array, the power-saving source driver chip has:

a first detection circuit for detecting a row of display data to generate a first detection result, wherein when the highest two bits of the display data in the row of display data are both 1, the first detection The detection result is in an active state, otherwise, the first detection result is in an inactive state;

a register for latching the first detection result according to the control of a clock signal, and providing an output state representing the previous state of the first detection result accordingly;

a second detection circuit for detecting the next line of display data to generate a second detection result, wherein when the highest two bits of the display data in the next line of display data are both 0, the first The second detection result is in an active state, otherwise, the second detection result is in an inactive state; and

A logic gate outputs an enable signal to drive a switch circuit to perform a charge sharing operation on the TFT liquid crystal array when both the output state and the second detection result are in active states.

In one embodiment, the logic gate is a gate and a gate.

In one embodiment, the logic gate is a NOT-OR gate.

In order to achieve the aforementioned object, the present invention further provides an information processing device having a central processing unit and a liquid crystal display, wherein the central processing unit is used for communication with the liquid crystal display, and the liquid crystal display has a power saving type A source driver chip and a TFT liquid crystal array, the power-saving source driver chip has:

a detection circuit for judging whether the numerical difference between the display data of two adjacent rows is greater than a threshold; and

A charge sharing control circuit is used for driving a switch circuit to perform a charge sharing operation on the TFT liquid crystal array when the value difference is greater than the threshold.

In a possible embodiment, the information processing device may be a portable computer or a smart handheld device.

The principle of the present invention is:

(1) Detecting a row of display data to generate a first detection result, wherein when the highest two bits of the display data in the row of display data are both 1, the first detection result is in an active state, Otherwise, the first detection result is rendered inactive;

(2) temporarily storing the first detection result to provide the previous state of the first detection result;

(3) Detecting the display data of the next line to generate a second detection result, wherein when the highest two bits of the display data in the display data of the next line are both 0, the second detection result is displayed. state, otherwise, the second detection result is rendered inactive; and

(4) When the previous state of the first detection result and the second detection result are both active states, output an enable signal to drive a switch circuit to perform a charge sharing operation on a TFT liquid crystal array.

That is, the principle of the power-saving source driver chip of the present invention is to set a detection circuit and a charge sharing control circuit, and the detection circuit determines whether the numerical difference between the display data of two adjacent rows is greater than a threshold value, When the value difference is greater than the threshold value, the charge sharing control circuit is driven to drive a switch circuit to perform a charge sharing operation on a TFT liquid crystal array.

Accordingly, the present invention can perform a charge sharing operation on two adjacent channels of a TFT liquid crystal array when the timing controller does not detect that the display data has a still image and does not change the polarity of the pixel voltage. , in order to save the power consumption of the TFT liquid crystal array.

Please refer to FIG. 2 , which shows a block diagram of a liquid crystal display including an embodiment of the power-saving source driver chip of the present invention. As shown in FIG. 2 , a liquid crystal display 100 includes a power-saving source driver chip 110 and a TFT liquid crystal array 120 . In order to demonstrate the technical features of the present invention, other constituent elements in the liquid crystal display 100 that are not directly related to the present invention, such as a gate driving chip and a backlight module, are not shown in FIG. 2 .

The power-saving source driver chip 110 has a first detection circuit 111 , a register 112 , a second detection circuit 113 , a logic AND gate 114 and a switch circuit 115 .

The first detection circuit 111 is used for detecting a row of display data D _DISPL1 to generate a first detection result S _HH , wherein when the two highest bits of the display data in the row of display data D _DISPL1 are both 1 , the first detection result S _HH is in an active state, otherwise, the first detection result S _HH is in an inactive state.

The register 112 is used for latching the first detection result _SHH according to the control of a clock signal CLK, and accordingly provides an output state S _HHP representing the previous state of the first detection result, that is, in Before the clock signal CLK has a latching effect on the register 112, the output state S _HHP shows the previous state of the first detection result S _HH .

The second detection circuit 113 is used for detecting the next line of display data D _DISPL2 to generate a second detection result S _LL , wherein when the next line of display data D _DISPL2 has the highest two bits of the display data both are When the value is 0, the second detection result S _LL is in an active state; otherwise, the second detection result S _LL is in an inactive state.

The logic AND gate 114 outputs an enable signal EN to drive the switch circuit 115 to perform a charge sharing operation on the TFT liquid crystal array 120 when the output state S _HHP and the second detection result S _LL are both active. That is, in the power-saving source driver chip 110 of the present invention, one pixel gray level in a row is greater than or equal to a first predetermined gray level (the highest two bits of the display data are both 1 is only an example), When the gray level of one pixel in the other row is lower than or equal to a second predetermined gray level (the uppermost two bits of the display data are both 0 as an example), the charge sharing operation is performed on the TFT liquid crystal array 120 .

It should be specially pointed out here that the logic AND gate 114 can also be replaced by other logic circuits, for example, a logic NOT OR gate. In the case of using the logic AND gate 114, the active state refers to a high potential; when the logical AND gate 114 is replaced by a logical NOT OR gate, the active state refers to a low potential.

The switch circuit 115 is used to redistribute the charges of the pixel capacitors in the two adjacent data channels of the TFT liquid crystal array 120 when enabled by the enable signal EN, thereby reducing the establishment time of a new pixel voltage.

According to the above description, the present invention further provides an information processing device. Please refer to FIG. 3 , which shows a block diagram of an embodiment of the information processing apparatus of the present invention. As shown in FIG. 3 , an information processing device 200 has a central processing unit 210 and a liquid crystal display 220 , wherein the central processing unit 210 is used for communicating with the liquid crystal display 220 and the liquid crystal display 220 is realized by the liquid crystal display 100 . In addition, the information processing device 200 can be a portable computer or a smart handheld device.

According to the above description, the present invention can provide the following advantages:

1. In the power-saving source driver chip of the present invention, when the timing controller does not instruct the polarity of the pixel voltage to be changed, the grayscale of one pixel in a row can still be greater than or equal to a first predetermined grayscale, and A charge sharing operation is performed on a TFT liquid crystal array when one pixel gray level of the other row is lower than or equal to a second predetermined gray level.

2. In the liquid crystal display of the present invention, when the timing controller does not instruct the polarity of the pixel voltage to be changed, the grayscale of one pixel in one row is greater than or equal to a first predetermined grayscale, while the grayscale of one pixel in the other row is greater than or equal to a first predetermined grayscale. When the pixel gray level is lower than or equal to a second predetermined gray level, a charge sharing operation is performed on a TFT liquid crystal array to save power consumption.

3. The information processing device of the present invention can save power consumption due to the aforementioned liquid crystal display.

What is disclosed in the present invention is one of the preferred embodiments, and any partial changes or modifications originating from the technical idea of the present invention and easily inferred by those skilled in the art are within the scope of the patent right of the present invention.

To sum up, regardless of the purpose, means and effect of this case, it shows that it is completely different from the conventional technology, and its first invention is suitable for practical use, and indeed meets the patent requirements of the invention. Society is to pray for the best.

11: Timing Controller 12: Polarity change detection unit 13: Source driver 14: TFT liquid crystal array 100: LCD display 110: Power-saving source driver chip 111: The first detection circuit 112: Scratchpad 113: Second detection circuit 114: Logic and Gates 115: switch circuit 120: TFT liquid crystal array 200: Information processing device 210: Central Processing Unit 220: LCD display

In order to further disclose the specific technical content of the present invention, please refer to the drawings first, wherein: FIG. 1 is a block diagram of a charge sharing control circuit of a conventional liquid crystal display. FIG. 2 is a block diagram of a liquid crystal display including the power-saving source driver chip of the present invention. FIG. 3 is a block diagram illustrating an embodiment of the information processing apparatus of the present invention.

100: LCD display

110: Power-saving source driver chip

111: The first detection circuit

112: Scratchpad

113: Second detection circuit

114: Logic and Gates

115: switch circuit

120: TFT liquid crystal array

Claims (13)

A power-saving source driver chip, which has: a first detection circuit for detecting a row of display data to generate a first detection result, wherein when the row of display data has the highest two display data When the bits are all 1, the first detection result is in an active state; otherwise, the first detection result is in an inactive state; a register is used to latch the first detection result according to the control of a clock signal. a detection result to provide an output state representing the previous state of the first detection result; a second detection circuit to detect the next line of display data to generate a second detection result, wherein, When the uppermost two bits of the display data in the next line of display data are both 0, make the second detection result in an active state; otherwise, make the second detection result in an inactive state; and a logic The gate outputs an enable signal to drive a switch circuit to perform a charge sharing operation on a TFT liquid crystal array when both the output state and the second detection result show an active state. The power-saving source driving chip as described in claim 1, wherein the logic gate is a gate and a gate. The power-saving source driving chip of claim 1, wherein the logic gate is a NOT-OR gate. A power-saving source driver chip, which has: a detection circuit for judging whether the numerical difference of display data of two adjacent rows is greater than a threshold; and a charge sharing control circuit for when the numerical difference is greater than the At the threshold, a switch circuit is driven to perform a charge sharing operation on a TFT liquid crystal array. A liquid crystal display, which has a power-saving source driver chip and a TFT liquid crystal array, the power-saving source driver chip has: a first detection circuit for detecting a row of display data to generate a first detection circuit The test result, wherein, when the highest two bits of the display data in the row of display data are both 1, the first detection result is in an active state; otherwise, the first detection result is in an inactive state ; a register for latching the first detection result according to the control of a clock signal, and providing generation An output state representing the previous state of the first detection result; a second detection circuit for detecting the display data of the next line to generate a second detection result, wherein, when the display data of the next line has a display When the highest two bits of the data are both 0, the second detection result is in an active state, otherwise, the second detection result is in an inactive state; and a logic gate is connected between the output state and the When the second detection results are in the active state, an enable signal is output to drive a switch circuit to perform a charge sharing operation on the TFT liquid crystal array. The liquid crystal display as described in claim 5, wherein the logic gate is a gate and a gate. The liquid crystal display as described in claim 5, wherein the logic gate is a NOT-OR gate. A liquid crystal display, which has a power-saving source driver chip and a TFT liquid crystal array, the power-saving source driver chip has: a detection circuit for judging whether the numerical difference between the display data of two adjacent rows is greater than or equal to a threshold; and a charge-sharing control circuit for driving a switch circuit to perform a charge-sharing operation on the TFT liquid crystal array when the value difference is greater than the threshold. An information processing device has a central processing unit and a liquid crystal display, wherein the central processing unit is used for communication with the liquid crystal display, and the liquid crystal display has a power-saving source driver chip and a TFT liquid crystal array, The power-saving source driver chip has: a first detection circuit for detecting a row of display data to generate a first detection result, wherein when the row of display data has the highest two bits of the display data When both are 1, the first detection result is in an active state, otherwise, the first detection result is in an inactive state; a register is used to latch the first detection result according to the control of a clock signal a detection result, and provide an output state representing the previous state of the first detection result; a second detection circuit is used to detect the display data of the next line to generate a second detection result, wherein, when the In the next line of display data, when the highest two bits of the display data are both 0, the second detection result is in an active state; otherwise, the second detection result is in an inactive state; and A logic gate outputs an enable signal to drive a switch circuit to perform a charge sharing operation on the TFT liquid crystal array when both the output state and the second detection result are in active states. The information processing device as described in claim 9, wherein the logic gate is a gate and a gate. The information processing device as described in claim 9, wherein the logic gate is a NOT-OR gate. An information processing device has a central processing unit and a liquid crystal display, wherein the central processing unit is used for communication with the liquid crystal display, and the liquid crystal display has a power-saving source driver chip and a TFT liquid crystal array, The power-saving source driver chip has: a detection circuit for judging whether the numerical difference between the display data of two adjacent rows is greater than a threshold; and a charge sharing control circuit for when the numerical difference is greater than the threshold A switch circuit is driven to perform a charge sharing operation on the TFT liquid crystal array. The information processing device according to any one of items 9 to 12 of the scope of the application is a portable computer or a smart handheld device.

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