CN101593501A - The driving method of LCD and drive unit thereof - Google Patents

Abstract

The present invention proposes a kind of driving method and drive unit thereof of LCD, above-mentioned drive unit comprises difference circuit, the gray scale variation degree of picture determines whether activation overdrive circuit and memory controller before and after this difference circuit utilization, when the variation of front and back picture during less than default value, forbidden energy overdrive circuit and memory controller are to reduce power consumption.

Description

The driving method of LCD and drive unit thereof

Technical field

The invention relates to a kind of driving method and drive unit thereof of LCD, and particularly relevant for a kind of driving method and drive unit thereof with energy-saving effect.

Background technology

LCD (LiquidCrystalDisplay, LCD) used widely recently, improvement along with Driving technique, make it have advantages such as low consumption electric power, slim amount are light, low voltage drive, be applied in widely at present and shot with video-corder on projector, mobile computer, desktop display and the various projector equipment.With regard to display device, have that the high spatial utilization ratio is good, (Thin Film TransistorLiquid Crystal Display TFT-LCD) becomes the main flow in market to the Thin Film Transistor-LCD of low consumpting power, advantageous characteristic such as radiationless gradually.

Yet in order to improve the reaction time of LCD, its drive unit can utilize overdrive circuit to drive liquid crystal usually, to quicken the transition of liquid crystal.Please refer to Fig. 1, Fig. 1 is the driving circuit according to known techniques, and it comprises memory body 110, memory controller 120 and overdrive circuit 130.Memory controller 120 can be stored to last picture data in the memory body 110, and then, overdrive circuit 130 can read last picture data in the memory body 110, and compares with the output picture data of overdriving with present picture data.Overdrive circuit 130 can be adjusted drive signal to quicken the reaction time of picture element according to the variation of picture.Yet prior art goes round and begins again and constantly each picture is write memory body and read last picture that has write, and so action does not have any help and causes empty wasted work rate image quality when GTG changes.

Summary of the invention

The invention provides a kind of driving method and drive unit thereof of LCD, it is according to the gray scale variation degree of picture optionally activation overdrive circuit and memory controller.When picture changes hour, forbidden energy overdrive circuit and memory controller are with the reduction power consumption.

Hold above-mentioned, the present invention proposes a kind of driving method, is applicable to the drive unit of LCD, and above-mentioned drive unit comprises a memory body, a memory controller and an overdrive circuit, above-mentioned driving method comprises the following steps: at first, and picture is divided into a plurality of picture element blocks; Then, receive one first picture data and one second picture data in regular turn; According to the pairing picture element GTG of each above-mentioned picture element block value, obtain a plurality of first GTG differences of corresponding above-mentioned first picture data respectively and corresponding to a plurality of second GTG differences of above-mentioned second picture data; And more above-mentioned first GTG difference and the above-mentioned second GTG difference, and whether determine above-mentioned memory controller of activation and above-mentioned overdrive circuit according to the comparative result of above-mentioned first GTG difference and the above-mentioned second GTG difference.

The matrix block that wherein above-mentioned in an embodiment of the present invention picture element block is M * N, and the formula of calculating GTG difference is as follows:

$\mathrm{SOD}(R,C)=\underset{m=R}{\overset{R+Q-1}{\mathrm{\Σ}}}\underset{n=C}{\overset{C+Y-1}{\mathrm{\Σ}}}|P(m,n)-P(m,n-1)|$

Wherein, SOD (R, C) expression GTG difference, (R C) is the upper left side picture element coordinate of picture element block, (m, n) expression picture element coordinate figure, P (m, n) the picture element GTG value of above-mentioned first picture data of expression, Q represents the height of picture element block, Y represents the width of picture element block, wherein when n=1, and P (m, 0)=0, wherein R, C, m, Q, Y are all positive integer.

In an embodiment of the present invention, the above-mentioned first GTG difference and the step of the above-mentioned second GTG difference comprise the following steps: relatively to be positioned at the above-mentioned first GTG difference and the above-mentioned second GTG difference of identical picture element block, and according to the difference between above-mentioned first GTG difference and the above-mentioned second GTG difference whether greater than one first threshold value to determine an effective difference number; And when above-mentioned effective difference number during greater than one second threshold value, above-mentioned memory controller of activation and above-mentioned overdrive circuit, when above-mentioned effective difference number during less than above-mentioned second threshold value, above-mentioned memory controller of forbidden energy and above-mentioned overdrive circuit.

From another perspective, the present invention more proposes a kind of drive unit of LCD, is applicable to drive a liquid crystal panel, and above-mentioned drive unit comprises a memory body, a memory controller, an overdrive circuit and a difference circuit.Wherein difference circuit is coupled to above-mentioned memory controller and above-mentioned overdrive circuit, in order to carry out the following step: picture is divided into a plurality of picture element blocks; Receive one first picture data and one second picture data in regular turn; According to the pairing picture element GTG of each above-mentioned picture element block value, obtain a plurality of first GTG differences of corresponding above-mentioned first picture data respectively and corresponding to a plurality of second GTG differences of above-mentioned second picture data; And more above-mentioned first GTG difference and the above-mentioned second GTG difference, and whether determine above-mentioned memory controller of activation and above-mentioned overdrive circuit according to the comparative result of above-mentioned first GTG difference and the above-mentioned second GTG difference.All the other details of operations of drive unit are described as above-mentioned driving method, do not repeat them here.

Based on above-mentioned, the present invention utilizes the gray scale variation of picture to determine whether activation overdrive circuit and memory controller, under the situation of keeping the script image quality, reduces power consumption by forbidden energy overdrive circuit and memory controller.

For above-mentioned feature and advantage of the present invention can be become apparent, embodiment cited below particularly, and cooperate appended graphic being described in detail below.

Description of drawings

Fig. 1 is the driving circuit according to known techniques.

Fig. 2 is drive unit according to an embodiment of the invention.

Fig. 3 is the picture element block diagram according to present embodiment.

Fig. 4 is driving method according to an embodiment of the invention.

Primary clustering symbol description in the accompanying drawing:

110,210: memory body

120,220: memory controller

130,230: overdrive circuit

240: difference circuit

SOD (R, C): picture element block label

S410 ~ S450: flow chart step

Embodiment

Please refer to Fig. 2, Fig. 2 is drive unit according to an embodiment of the invention, and it comprises memory body 210, memory controller 220, overdrive circuit 230 and difference circuit 240.Overdrive circuit 230 is coupled to memory controller 220,220 read-write motion that are used for controlling memory body 110 of memory controller with difference circuit 240.230 of overdrive circuits are the computings that are used for overdriving with the output picture data of overdriving.

Difference circuit 240 can be carried out computing to obtain corresponding GTG difference to the picture data that is received, and tranmittance determines whether activation overdrive circuit 230 and memory controller 220 to the GTG difference of front and back picture then.When picture changes greatly, difference circuit 240 meeting activation overdrive circuits 230 and memory controller 220, memory controller 220 can store the computing of picture data to overdrive that is received in regular turn at this moment.When picture changes hour, difference circuit 240 can forbidden energy overdrive circuits 230 and memory controllers 220, and this moment, memory controller 220 can not store the picture data that is received, the computing that driving circuit 230 also can not be overdrived.

The step that difference circuit 240 is calculated the GTG difference is as follows: at first, picture is divided into a plurality of picture element blocks, as shown in Figure 3, Fig. 3 is the picture element block diagram according to present embodiment.Fig. 3 is that the display panel with 192 * 120 esolving degrees is an example, wherein each picture element region block size is 10 * 10 picture element block, its expression mode is SOD (R, C), (R C) is the upper left side picture element coordinate of picture element block, SOD (R, C) numerical value is the GTG difference of above-mentioned picture element block, and its formula is as follows:

$\mathrm{SOD}(R,C)=\underset{m=R}{\overset{R+Q-1}{\mathrm{\Σ}}}\underset{n=C}{\overset{C+Y-1}{\mathrm{\Σ}}}|P(m,n)-P(m,n-1)|$

(m, n) expression picture element coordinate figure, P (Q represents the height (representing with the picture element number) of picture element block for m, n) the picture element GTG value of expression picture data, and Y represents the width (representing with the picture element number) of picture element block, wherein when n=1, and P (m, 0)=0.As shown from the above formula, the GTG difference be by the difference of GTG value between the picture element on the picture element in the individual block and the adjacent left side with form, and the picture element on border is (as P (1,1) ~ P (10,1)),, therefore keeps original GTG value because its left side has not had picture element.It should be noted that (R only is the wherein a kind of mode that is used for indicating the picture element block C) to SOD, and present embodiment is not limited.The size of each picture element piece also can be decided according to design requirement, is not subject to present embodiment equally.

Then, difference circuit 240 can according to the picture order that is received, be calculated its corresponding GTG difference when receiving picture data, then according to the position of individual block, and the GTG difference of picture before and after comparing.When the GTG difference differs by more than threshold value, then classify this picture element block as effective difference block, promptly represent the picture element block that gray scale variation is bigger.The number of adding up all effective difference block can obtain an effective difference number, can judge the gray scale variation degree of picture by the effective numerical value of difference number.As the heterodyne heteromerism during greater than default threshold value, i.e. activation memory controller 120 and the computing of overdrive circuit 130 with the picture data of overdriving.As the heterodyne heteromerism during less than default threshold value, promptly forbidden energy memory controller 120 and overdrive circuit 130 are to reduce power consumption.

Owing to represent that the gray scale variation degree of whole picture is less when effectively the difference number is less than default threshold value, even therefore forbidden energy memory controller 120 can not influence image quality with overdrive circuit 130 yet, but can effectively reduce the consumed power of memory controller 120 and memory body 110.In other words, present embodiment is that the gray scale variation degree according to picture determines whether the computing of activation overdrive circuit 230 to overdrive, propose to judge picture gray scale variation degree methods simultaneously, just be a plurality of picture element blocks with picture segmentation, and the GTG difference in the calculating individual block, tranmittance decides the gray scale variation degree of its picture than the GTG difference of front and back picture then.It should be noted that, because difference circuit 240 only need store the GTG difference of picture out of the ordinary and can compare, therefore in the process that compares the GTG difference, need not store the data of whole picture, only when activation overdrive circuit 230, just need store the data of whole picture.

From another perspective, can summarize a kind of driving method by the foregoing description, as shown in Figure 4, Fig. 4 is driving method according to an embodiment of the invention, be applicable to the drive unit of LCD, this drive unit comprises a memory body, one memory controller and an overdrive circuit, this driving method comprises the following steps: at first, picture is divided into a plurality of picture element blocks (step S410), receive first picture data and second picture data (step S420) then in regular turn, next, obtain GTG difference (step S430) in regular turn corresponding to first picture data and second picture.After obtaining the GTG difference, relatively before and after the GTG difference (step S440) of picture, and whether determine activation memory controller and overdrive circuit (step S450) according to comparative result.In step S450, when the differing greatly of the GTG difference of front and back picture, when promptly effectively the difference number is greater than threshold value, activation memory controller and overdrive circuit.When the difference of the GTG difference of front and back picture hour, when promptly effectively the difference number was less than threshold value, forbidden energy memory controller and overdrive circuit were with the reduction power consumption.

In sum, the present invention proposes to judge front and back picture gray scale variation degree methods with the GTG difference, and according to the change degree of GTG difference optionally forbidden energy memory controller and overdrive circuit to reduce power consumption, allow LCD can when picture changes less or tableaux, reach the effect of energy saving, when dynamic menu, keep its image quality simultaneously.

Though the present invention discloses as above with embodiment; right its is not in order to limit the present invention; have in the technical field under any and know the knowledgeable usually; without departing from the spirit and scope of the present invention; when doing a little change and retouching, so protection scope of the present invention is as the criterion when looking claims scope person of defining.

Claims (10)

1. the driving method of a LCD is applicable to the drive unit of LCD, and this drive unit comprises a memory body, a memory controller and an overdrive circuit, it is characterized in that, described driving method comprises:

Picture is divided into a plurality of picture element blocks;

Receive one first picture data and one second picture data in regular turn;

According to the pairing picture element GTG of this picture element block value respectively, obtain respectively to a plurality of first GTG differences that should first picture data and corresponding to a plurality of second GTG differences of this second picture data; And

Relatively those first GTG differences and those second GTG differences, and whether determine this memory controller of activation and this overdrive circuit according to the comparative result of those first GTG differences and those second GTG differences.

2. the driving method of LCD according to claim 1 is characterized in that, those picture element blocks matrix block that is M * N wherein, and wherein M, N are positive integer.

3. the driving method of LCD according to claim 1 is characterized in that, wherein those first GTG differences are corresponding to those picture element blocks, and the formula that calculates those first GTG differences is as follows:

$\mathrm{SOD}(R,C)=\underset{m=R}{\overset{R+Q-1}{\mathrm{\Σ}}}\underset{n=C}{\overset{C+Y-1}{\mathrm{\Σ}}}|P(m,n)-P(m,n-1)|$

Wherein, (R C) represents those first GTG differences to SOD, (R C) is the upper left side picture element coordinate of picture element block, (m, n) expression picture element coordinate figure, (m n) represents the picture element GTG value of this first picture data to P, Q represents the height of picture element block, Y represents the width of picture element block, wherein when n=1, and P (m, 0)=0, wherein R, C, m, Q, Y are all positive integer.

4. the driving method of LCD according to claim 1, wherein those second GTG differences are corresponding to those picture element blocks, the formula that calculates those second GTG differences is as follows:

$\mathrm{SOD}(R,C)=\underset{m=R}{\overset{R+Q-1}{\mathrm{\Σ}}}\underset{n=C}{\overset{C+Y-1}{\mathrm{\Σ}}}|P(m,n)-P(m,n-1)|$

Wherein, (R C) represents those second GTG differences to SOD, (R C) is the upper left side picture element coordinate of picture element block, (m, n) expression picture element coordinate figure, (m n) represents the picture element GTG value of this second picture data to P, Q represents the height of picture element block, Y represents the width of picture element block, wherein when n=1, and P (m, 0)=0, wherein R, C, m, Q, Y are all positive integer.

5. the driving method of LCD according to claim 1 is characterized in that, wherein comprises in the step that compares those first GTG differences and those second GTG differences:

Relatively be positioned at those first GTG differences and those second GTG differences of identical picture element block, and according to the difference between those first GTG differences and those the second GTG differences whether greater than one first threshold value to determine an effective difference number; And

When this effective difference number during, this memory controller of activation and this overdrive circuit greater than one second threshold value, when this effective difference number during less than this second threshold value, this memory controller of forbidden energy and this overdrive circuit.

6. the drive unit of a LCD is applicable to drive a liquid crystal panel, it is characterized in that this drive unit comprises:

One memory body;

One memory controller is coupled to this memory body;

One overdrive circuit is coupled to this memory controller, in order to produce the picture data of overdriving; And

One difference circuit is coupled to this memory controller and this overdrive circuit, and wherein this difference circuit is in order to carry out the following step:

Picture is divided into a plurality of picture element blocks;

Receive one first picture data and one second picture data in regular turn;

According to the pairing picture element GTG of this picture element block value respectively, obtain respectively to a plurality of first GTG differences that should first picture data and corresponding to a plurality of second GTG differences of this second picture data; And

Relatively those first GTG differences and those second GTG differences, and whether determine this memory controller of activation and this overdrive circuit according to the comparative result of those first GTG differences and those second GTG differences.

7. the drive unit of LCD according to claim 6 is characterized in that, those picture element blocks matrix block that is M * N wherein, and wherein M, N are positive integer.

8. the drive unit of LCD according to claim 6 is characterized in that, wherein those first GTG differences are corresponding to those picture element blocks, and the formula that calculates those first GTG differences is as follows:

$\mathrm{SOD}(R,C)=\underset{m=R}{\overset{R+Q-1}{\mathrm{\Σ}}}\underset{n=C}{\overset{C+Y-1}{\mathrm{\Σ}}}|P(m,n)-P(m,n-1)|$

Wherein, (R C) represents those first GTG differences to SOD, (R C) is the upper left side picture element coordinate of picture element block, (m, n) expression picture element coordinate figure, (m n) represents the picture element GTG value of this first picture data to P, Q represents the height of picture element block, P represents the width of picture element block, wherein when n=1, and P (m, 0)=0, wherein R, C, m, Q, Y are all positive integer.

9. the drive unit of LCD according to claim 6 is characterized in that, wherein those second GTG differences are corresponding to those picture element blocks, and the formula that calculates those second GTG differences is as follows:

$\mathrm{SOD}(R,C)=\underset{m=R}{\overset{R+Q-1}{\mathrm{\Σ}}}\underset{n=C}{\overset{C+Y-1}{\mathrm{\Σ}}}|P(m,n)-P(m,n-1)|$

Wherein, (R C) represents those second GTG differences to SOD, (R C) is the upper left side picture element coordinate of picture element block, (m, n) expression picture element coordinate figure, (m n) represents the picture element GTG value of this second picture data to P, Q represents the height of picture element block, P represents the width of picture element block, wherein when n=1, and P (m, 0)=0, wherein R, C, m, Q, Y are all positive integer.

10. the drive unit of LCD according to claim 6 wherein comprises in the step of those first GTG differences and those second GTG differences relatively:

Relatively be positioned at those first GTG differences and those second GTG differences of identical picture element block, and according to the difference between those first GTG differences and those the second GTG differences whether greater than one first threshold value to determine an effective difference number; And

When this effective difference number during, this memory controller of activation and this overdrive circuit greater than one second threshold value, when this effective difference number during less than this second threshold value, this memory controller of forbidden energy and this overdrive circuit.

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