TWI684975B - Dynamic power management method of display drive circuit, display drive chip and display device - Google Patents

Abstract

A dynamic power management method for a display driving circuit is realized by using a control circuit, which includes the following steps: executing a maximum pixel brightness value detection process on a frame of picture data to generate a maximum brightness value, and executing on the frame of picture data An average pixel brightness value is calculated to generate an average brightness value; a weighted average is generated according to the maximum brightness value and the average brightness value to generate a weighted average brightness value; and a corresponding power supply voltage is selected according to the weighted average brightness value to do Supply voltage for a source driving circuit.

Description

Dynamic power management method of display drive circuit, display drive chip and display device

The invention relates to a display driving circuit, in particular to a dynamic power management method of a display driving circuit.

In order to save power, the general display driver chip generally develops a dynamic power management (DPM) function module to dynamically adjust the output of a power management chip to a frame based on the average brightness of each frame. A power voltage value of the display panel. Please refer to FIG. 1, which illustrates a block diagram of a conventional dynamic power management function module. As shown in FIG. 1, a dynamic power management function module 10 has an average calculation unit 11 and a table look-up unit 12, wherein the average calculation unit 11 is used to calculate the average brightness I _{AVG of} a frame of pixel data D _P ; And the table lookup unit 12 has an average brightness-power supply voltage comparison table, the table is generated according to an average brightness-power supply voltage conversion curve shown in Figure 2, and the table lookup unit 12 is based on the comparison table for the average brightness Value I _AVG performs a table lookup operation to obtain a power supply voltage selection code D _VSEL , so that a display driver chip can select a corresponding power supply voltage value according to the power supply voltage selection code D _VSEL to supply power to a display panel.

However, since the dynamic power management function module 10 shown in FIG. 1 determines the power voltage value according to the average brightness of the entire display screen, as shown in FIG. 3, when there is only a very small When the local area 21 is brighter and the other areas 22 are darker, since the average brightness of the entire image will be much lower than that of the local area 21, the power generated by the dynamic power management function module 10 of FIG. 1 The voltage may not be high enough to support the brightness requirement of the local area 21. That is to say, although the power supply voltage generated according to the average brightness can meet the requirement of the darker brightness of the other area 22, for the higher brightness requirement of the local area 21, insufficient conditions may occur.

Therefore, there is an urgent need in the art for a novel dynamic power management method for display driver circuits.

An object of the present invention is to provide a dynamic power management method for a display driving circuit, which can dynamically determine the driving power voltage of a display by detecting the maximum brightness value and the average brightness value of a frame.

Another object of the present invention is to provide a dynamic power management method for a display driving circuit, which can make the output power voltage not only adjust with the average brightness of a display screen without adding too many hardware circuits The problem that the power supply voltage cannot support the brightness requirement of the local small area can be avoided when the brightness of a local small area is much higher than the average brightness of the entire display screen.

Another object of the present invention is to provide a dynamic power management method for a display driving circuit, which can not only adjust the average brightness of a display screen but also adjust the average brightness of a display screen under a simple and small calculation process The problem that the power supply voltage cannot support the brightness requirement of the local small area can be avoided when the brightness of a local small area is much higher than the average brightness of the entire display screen.

To achieve the above objective, a dynamic power management method for a display driving circuit is proposed, which is implemented by a control circuit and includes the following steps:

Perform a maximum pixel brightness value detection procedure on a frame of picture data to generate a maximum brightness value, and perform an average pixel brightness value calculation on the frame of picture data to generate an average brightness value;

Performing a weighted average based on the maximum brightness value and the average brightness value to generate a weighted average brightness value; and

According to the weighted average brightness value, a corresponding power supply voltage is selected as the supply voltage of a source driving circuit.

In an embodiment, the maximum pixel brightness value detection process includes:

Preset a first pixel brightness value in the frame picture data as a tentative maximum brightness value; and

Sequentially, each pixel brightness value after the first pixel brightness value in the frame picture data is regarded as a current pixel brightness value, and the current pixel brightness value is compared with the provisional maximum brightness value to determine the Whether the current pixel brightness value is greater than the provisional maximum brightness value, if so, the provisional maximum brightness value is updated with the current pixel brightness value, if not, the provisional maximum brightness value is not updated.

In order to achieve the above object, the present invention further provides a display driving chip having a control circuit, an adjustable power supply voltage circuit and a source driving circuit. The control circuit generates a control parameter by executing a dynamic power management method Adjusting one of the output voltages of the adjustable power supply voltage circuit, which is used as the supply voltage of the source driving circuit, and the control circuit has a comparison unit, a storage unit, an average calculation unit, a A weighted average unit and a table lookup unit, the dynamic power management method includes the following steps:

Use the comparison unit and the storage unit to perform a maximum pixel brightness value detection process on a frame of picture data to generate a maximum brightness value, and use the average calculation unit to perform an average pixel brightness value calculation on the frame of picture data to generate a Average brightness value

Using the weighted average unit to perform a weighted average calculation on the maximum brightness value and the average brightness value to generate a weighted average brightness value; and

A look-up operation is performed on the weighted average brightness value using an average brightness-power supply voltage conversion table in the table look-up unit to obtain the control parameter.

In an embodiment, the maximum pixel brightness value detection process includes:

Preset a first pixel brightness value in the frame picture data as a tentative maximum brightness value and store it in the storage unit; and

Use the comparison unit to sequentially take each pixel brightness value after the first pixel brightness value in the frame picture data as a current pixel brightness value, and make the current pixel brightness value and the provisional maximum brightness value proceed Compare to determine whether the current pixel brightness value is greater than the provisional maximum brightness value. If yes, update the provisional maximum brightness value with the current pixel brightness value. If not, do not update the provisional maximum brightness value.

To achieve the above object, the present invention further provides a display device having a display panel and a display driving chip as described above for driving the display panel.

In a possible embodiment, the display device may be a liquid crystal display or an organic light emitting diode display.

In order to enable your review committee to further understand the structure, features, objectives, and extreme advantages of the present invention, the drawings and the detailed description of the preferred embodiments are attached as follows.

Please refer to FIG. 4, which is a flowchart of an embodiment of a dynamic power management method of a display driving circuit of the present invention, which is implemented by a control circuit. As shown in FIG. 4, the dynamic power management method includes: executing a maximum pixel brightness value detection procedure on a frame of picture data to generate a maximum brightness value, and performing an average pixel brightness value calculation on the frame of picture data to generate a Average brightness value (step a); performing a weighted average on the maximum brightness value and the average brightness value to generate a weighted average brightness value (step b); and selecting a corresponding power supply voltage as the weighted average brightness value as The supply voltage of a source driving circuit (step c).

In an embodiment, the maximum pixel brightness value detection process described in step a may include: presetting a first pixel brightness value in the frame picture data to a tentative maximum brightness value; and sequentially applying the frame Each pixel brightness value after the first pixel brightness value in the picture data is regarded as a current pixel brightness value, and the current pixel brightness value is compared with the provisional maximum brightness value to determine whether the current pixel brightness value If it is greater than the tentative maximum brightness value, if it is, the tentative maximum brightness value is updated with the current pixel brightness value, if not, the tentative maximum brightness value is not updated.

To further highlight the technical features of the present invention, please refer to FIG. 5, which illustrates a block diagram of an embodiment of the display driver chip of the present invention using a control circuit to implement the dynamic power management method of FIG. As shown in FIG. 5, a display driving chip 100 has a control circuit 110, an adjustable power supply voltage circuit 120, and a source driving circuit 130, wherein the control circuit 110 has a comparison unit 111, a storage unit 112, and an average The calculation unit 113, a weighting unit 114, a weighting unit 115, an addition unit 116 and a table lookup unit 117.

The control circuit 110 generates a control parameter D _SEL by performing a dynamic power management method to adjust one of the output power voltage V _{PW of the} adjustable power voltage circuit 120, and the output power voltage V _PW is used as the source driving circuit 130 Supply voltage. The dynamic power management method includes the following steps:

(1) Use the comparison unit 111 and the storage unit 112 to perform a maximum pixel brightness value detection process on a frame of picture data D _P to generate a maximum brightness value I _MAX , and use the mean calculation unit 113 to execute the frame picture data D _P An average pixel brightness value is calculated to generate an average brightness value I _AVG ;

(2) The weighting unit 114, the weighting unit 115, and the addition unit 116 perform a weighted average on the maximum brightness value I _MAX and the average brightness value I _AVG to generate a weighted average brightness value I _WAVG , where I _WAVG = a _‧ I _MAX +b _‧ I _AVG , a and b are positive numbers less than 1, and a+b=1; and

(3) A look-up operation is performed on the weighted average brightness value I _WAVG by using an average brightness-power supply voltage conversion table in the table look-up unit 117 to obtain the control parameter D _SEL , where the control parameter D _SEL is used to adjust One of the adjustable power supply voltage circuits 120 outputs the power supply voltage V _PW , and the output power supply voltage V _PW is used as the supply voltage of the source driving circuit 130.

Further, in step (1), the maximum pixel intensity value detection program comprising: a first pre-set the pixel intensity value in the frame picture data D _P is a provisional maximum luminance value and stored in the storage unit 112 ; and a comparing unit 111 sequentially using each of the frame pixel after the luminance value of the picture data D _P of the first pixel luminance values as the luminance values of a current pixel, the current pixel and the luminance value and the tentative The maximum brightness value is compared to determine whether the current pixel brightness value is greater than the provisional maximum brightness value. If it is, the provisional maximum brightness value is updated with the current pixel brightness value. If not, the provisional maximum brightness value is not updated. Accordingly, after processing the complete frame of picture data, the final value of the provisional maximum brightness value is the maximum brightness value I _MAX .

To achieve the above object, the present invention further provides a display device. Please refer to FIG. 6, which illustrates a block diagram of an embodiment of the display device of the present invention. As shown in FIG. 6, a display device 200 has a display panel 210 and a display driving chip 220 for driving the display panel 210, wherein the display driving chip 220 is implemented by the display driving chip 100 shown in FIG.

In a possible embodiment, the display device 200 may be a liquid crystal display or an organic light emitting diode display.

In this way, the above has completely and clearly explained the principles, technical solutions and technical spirit of the present invention; and, through the above, the present invention has the following advantages:

(1) The dynamic power management method of the display driving circuit of the present invention can dynamically determine the driving power voltage of a display by detecting the maximum brightness value and the average brightness value of a frame of picture, so as to take into account the picture quality and power saving effect.

(2) The dynamic power management method of the display driving circuit of the present invention can make the output power voltage not only adjust with the average brightness of a display screen but also avoid a part without adding too many hardware circuits When the brightness of the small area is much higher than the average brightness of the entire display screen, the power supply voltage cannot support the brightness requirement of the small area.

(3) The dynamic power management method of the display driving circuit of the present invention can not only adjust the output power voltage in accordance with the average brightness of a display screen, but also avoid a partial When the brightness of the small area is much higher than the average brightness of the entire display screen, the power supply voltage cannot support the brightness requirement of the small area.

It must be emphasized that the aforementioned disclosure in this case is a preferred embodiment, and any part of the modification or modification that originates from the technical idea of this case and is easily inferred by those who are familiar with the art, does not deviate from the patent of this case. Power category.

In summary, regardless of the purpose, means and effects of this case, it shows that it is very different from the conventional technology, and its first invention is practical and practical, and it does meet the patent requirements of the invention. I urge your review committee to investigate and give the patent to the AirPlus as soon as possible. Society is for supreme prayer.

<this invention>

Step a‧‧‧ Perform a maximum pixel brightness value detection procedure on a frame of picture data to generate a maximum brightness value, and perform an average pixel brightness value calculation on the frame of picture data to generate an average brightness value

Step b‧‧‧ Perform a weighted average based on the maximum brightness value and the average brightness value to generate a weighted average brightness value

Step c‧‧‧ Select a corresponding power supply voltage as the supply voltage of a source driving circuit according to the weighted average brightness value

100‧‧‧Display driver chip

110‧‧‧Control circuit

111‧‧‧Comparative unit

112‧‧‧Storage unit

113‧‧‧Mean calculation unit

114‧‧‧ weighting unit

115‧‧‧ weighting unit

116‧‧‧Addition unit

117‧‧‧ table lookup unit

120‧‧‧Adjustable power supply voltage circuit

130‧‧‧Source drive circuit

200‧‧‧Display device

210‧‧‧Display panel

220‧‧‧Display driver chip

<Learning>

10‧‧‧Dynamic power management function module

11‧‧‧Mean calculation unit

12‧‧‧Lookup unit

20‧‧‧ one frame

21‧‧‧The first area

22‧‧‧Other regions

FIG. 1 shows a block diagram of a conventional dynamic power management function module. FIG. 2 illustrates an average brightness-power voltage conversion curve used by the conventional dynamic power management function module of FIG. 1. FIG. 3 is a schematic diagram showing that only a very small area is brighter and other areas are darker in a frame. 4 is a flow chart of an embodiment of a method for dynamic power management of a display driving circuit of the present invention. FIG. 5 is a block diagram of an embodiment of the display driver chip of the present invention using a control circuit to implement the dynamic power management method of FIG. 4. 6 is a block diagram of an embodiment of the display device of the present invention.

Step a‧‧‧ Perform a maximum pixel brightness value detection procedure on a frame of picture data to generate a maximum brightness value, and perform an average pixel brightness value calculation on the frame of picture data to generate an average brightness value

Step b‧‧‧ Perform a weighted average based on the maximum brightness value and the average brightness value to generate a weighted average brightness value

Step c‧‧‧ Select a corresponding power supply voltage as the supply voltage of a source driving circuit according to the weighted average brightness value

Claims (6)

A dynamic power management method for a display driving circuit is realized by using a control circuit, which includes the following steps: executing a maximum pixel brightness value detection process on a frame of picture data to generate a maximum brightness value, and executing on the frame of picture data An average pixel brightness value is calculated to generate an average brightness value; a weighted average is generated according to the maximum brightness value and the average brightness value to generate a weighted average brightness value; and a corresponding power supply voltage is selected according to the weighted average brightness value to do Supply voltage for a source driving circuit. The dynamic power management method of the display driving circuit as described in item 1 of the patent scope, wherein the maximum pixel brightness value detection process includes: presetting a first pixel brightness value in the frame picture data as a tentative The maximum brightness value; and sequentially taking each pixel brightness value after the first pixel brightness value in the frame picture data as a current pixel brightness value, and making the current pixel brightness value and the provisional maximum brightness value A comparison is performed to determine whether the current pixel brightness value is greater than the provisional maximum brightness value. If so, the provisional maximum brightness value is updated with the current pixel brightness value. If not, the provisional maximum brightness value is not updated. A display driving chip having a control circuit, an adjustable power supply voltage circuit and a source drive circuit, the control circuit generates a control parameter by adjusting a dynamic power management method to adjust one of the adjustable power supply voltage circuits Output power supply voltage, which is used as the supply voltage of the source driving circuit, and the control circuit has a comparison unit, a storage unit, an average calculation unit, a first weighting unit, a second weighting Unit, an addition unit and a table lookup unit, the dynamic power management method includes the following steps: Use the comparison unit and the storage unit to perform a maximum pixel brightness value detection process on a frame of picture data to generate a maximum brightness value, and use the average calculation unit to perform an average pixel brightness value calculation on the frame of picture data to generate a An average brightness value; using the first weighting unit, the second weighting unit, and the addition unit to perform a weighted average calculation on the maximum brightness value and the average brightness value to generate a weighted average brightness value; and using the table lookup unit internally An average brightness-power supply voltage conversion table performs a look-up operation on the weighted average brightness value to obtain the control parameter. The display driver chip as described in item 3 of the patent application scope, wherein the maximum pixel brightness value detection process includes: presetting a first pixel brightness value in the frame image data to a tentative maximum brightness value and storing In the storage unit; and using the comparison unit to sequentially take each pixel brightness value after the first pixel brightness value in the frame picture data as a current pixel brightness value, and make the current pixel brightness value Compare with the provisional maximum brightness value to determine whether the current pixel brightness value is greater than the provisional maximum brightness value, if yes, update the provisional maximum brightness value with the current pixel brightness value, if not, do not update the provisional maximum brightness value . A display device has a display panel and a display driving chip as described in any one of items 3-4 of the patent application scope for driving the display panel. The display device as described in item 5 of the patent application is a liquid crystal display or an organic light emitting diode display.

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