Background technology
In the prior art, liquid crystal has to be unable to cope with the shortcoming that changes fast dynamic image because of transmissivity changes according to its response effect.For addressing this is that, in the prior art, utilize and apply the overdrive mode higher than general liquid crystal drive voltage, improve the method for response speed of liquid crystal.Generally in order to realize drawing a higher overdrive voltage according to the liquid crystal drive voltage of input, use the table of comparisons (Over-drive Look-Up Table) of overdriving to reach, this table of comparisons of overdriving for example can be internal memory.
See also Fig. 1, its for the overdriving of conventional LCD drive method (Over-drive, OD) table of comparisons (Look-Up Table, LUT).As shown in Figure 1, present existing over-driving method, be to set up initial GTG value (initial value) (or last picture GTG value, previousvalue) a corresponding target gray scale value (target value) (or this picture GTG value, current value) (Over-drive that overdrives, OD) table of comparisons (Look-Up Table, LUT), utilize this table of comparisons of overdriving (OD LUT) to apply the overdrive mode higher, to improve the method for response speed of liquid crystal than general liquid crystal drive voltage.In general, if this LCD can show 0~255 GTG, basically just need 255 initial GTG values and correspond to 255 target gray scale values, just need to store 255*255 over-drive value, will cause the excessive feasible whole cost of internal memory to rise.In order to solve the excessive problem of internal memory, initial GTG value and target gray scale value are cut.As shown in Figure 1,0~8 GTG of initial GTG value is the first initial GTG interval, and 8~16 GTGs are the second initial GTG interval ... by that analogy; Same, 0~8 GTG of target gray scale is the first target gray scale interval, 8~16 is the second target gray scale interval ... by that analogy.
And the table of comparisons of the prior art (Look-Up Table, LUT) initial GTG value (initial value) must be identical interval and interval value with the corresponding relation of target gray scale value (target value) in, so must be the table of comparisons (the Look-Up Table of a N*N form, LUT), for example initial as mentioned above GTG value (initial value) writes down an over-drive value with per 8 GTGs of target gray scale value (target value), and the over-drive value in the middle of the interval then utilizes interpolation method to learn.As shown in Figure 1.When the N value is big more, then the needed frame buffer (Frame Buffer) and the table of comparisons (LUT) are just big more in the liquid crystal system.In the design of existing product, mostly the N value is set and become 32 even 16.Advantage in the existing technology is its design concept because without any need for the judgement formula, thus be easy to design and hardware design comparatively simple, can put into practice in limited hardware and be issued to the effect of overdriving.
Yet in order to reduce hardware cost; the N value definitely can not be big in the conventional method, because so regular meeting appears at the target gray scale brightness (target grayscale luminance) that can't reach required in the time or takes place the situation that surpasses target gray scale brightness.If do not reach target gray scale brightness, in other words, just the response time of liquid crystal improves few; If but, make image quality not good in order to reach the required liquid crystal response time and need to reach the white balance effect again and cause colour cast (Color Shift).Therefore the effect of of the prior art overdriving (OD) method overdrive (OD) that desire to reach then can become quite limited.
Duty is event, and the present invention is an idea of thinking and improve invention in view of the disappearance of prior art, invents out " LCD drive method and the device " of this case.
Summary of the invention
Fundamental purpose of the present invention is for providing a kind of LCD drive method and device, the overdrive characteristic of fragment linearity of GTG value curve of utilization, Application Design goes out the table of comparisons of overdriving of the present invention, can simplify the needed internal memory of hardware, and can reach the effect that liquid crystal is overdrived.
Another object of the present invention is for providing a kind of LCD drive method and device, not only possessed (the Look-Up Table of the table of comparisons in the prior art, LUT) reduction computer hardware, reduce the characteristic of required memory, more can provide the GTG value of overdriving comparatively accurately, to reach the effect that liquid crystal is overdrived.
For reaching above-mentioned purpose, the invention provides a kind of LCD drive method, comprise the following step:
Overdrive GTG value curve and polynomial expression of utilization simulated this GTG value curve of overdriving and set up the table of comparisons of overdriving, and obtains the target gray scale value and initial GTG value of turning point;
According to the initial GTG value of turning point correspondence, utilize binary approach to determine the pairing numerical value of section of the initial GTG value in previous view data place;
With the pairing numerical value of section of this initial GTG value in previous view data place and output to the reference position table of comparisons, as the Input Address of this reference position table of comparisons;
Utilize the Input Address of this reference position table of comparisons corresponding data content as the turning point data table of comparisons;
Find all turning point data according to this turning point numerical value table of comparisons to the GTG value curve of should overdriving;
According to the target gray scale value of this turning point correspondence, utilize the section of binary approach decision current image data place target gray scale value;
According to the pairing numerical value of section of this current image data place target gray scale value and the section value corresponding at previous view data place, utilize this table of comparisons of overdriving, pairing multinomial coefficient is read;
Multinomial coefficient is sent into over-drive value calculation unit;
This over-drive value calculation unit receives this current image data and from the multinomial coefficient of this table of comparisons of overdriving, calculates this GTG value of overdriving, this current image data of output of overdriving.
This case must be by with following diagram and detailed description, in order to do more deep understanding.
Embodiment
For describing LCD drive method of the present invention and device, with following specific embodiment it is described, right interest field of the present invention is not confined to following embodiment.
See also Fig. 2, it is for GTG value curve (ODCurve) synoptic diagram of overdriving of conventional liquid crystal panel.As shown in Figure 2, therefore the GTG value of overdriving (OD value) that different initial GTG values is corresponding different with different target gray scale values produces the GTG value curve (OD Curve) of overdriving as shown in Figure 2.The characteristic that all can be divided into the fragment quafric curve according to all as can be known GTG value curves of overdriving of the GTG value curve (OD Curve) of overdriving shown in Figure 2, utilize the characteristic of the fragment quafric curve of this GTG value curve of overdriving, Application Design goes out LCD drive method of the present invention and device.
See also Fig. 3 a~3d, it is the linear synoptic diagram of the GTG value curve segment of overdriving of 0 GTG for the initial GTG value of the preferred embodiment of the present invention.Shown in Fig. 3 a, the GTG value curve of overdriving that initial GTG value is 0 GTG can be divided into fragment I, II, the III of three quafric curves, has two turning points (judge point).Utilize two turning points and overdrive GTG value and target gray scale value and three curve second order polynomial (Y=ax of the Origin And Destination of the GTG value curve of overdriving
2+ bx+c) can be similar to three curve segment I, II, the III of this GTG value curve of overdriving, the GTG value of wherein overdriving curve linear fragment I, II, III have three sets of curves second order polynomial coefficient a, b, c respectively, wherein x represents the target gray scale value, and Y represents the GTG value of overdriving.Utilize known coefficient a, b, c numerical value to set up and be stored in the table of comparisons of overdriving (OD LUT, Over-drive Look-up Table).According to shown in Figure 2, the GTG value curve of overdriving under the actual state should have 256 curves as can be known, yet because some curve approximation overlaps, only has tens of so actual needs uses the representational GTG value curve of overdriving.Therefore can utilize representational method of overdriving GTG value curve and curve segment to set up the table of comparisons of overdriving.Utilize this table of comparisons of overdriving (ODLUT) can reach the effect that liquid crystal is overdrived.The present invention has not only possessed the table of comparisons in the prior art (Look-Up Table, LUT) reduction computer hardware has reduced the characteristic of required memory, have improved the shortcoming on the prior art especially greatly on the degree of accuracy of GTG value is overdrived in generation again.
See also Fig. 4, it is overdrive GTG value curve and target gray scale value, initial GTG value and the turning point synoptic diagram of the preferred embodiment of the present invention.As shown in Figure 4, different initial GTG values, its curve of overdriving can utilize three curve segment or a plurality of curve segment to be similar to the curve of overdriving of its correspondence.If utilize three curve segment to be similar to the curve of overdriving of its correspondence, promptly have two turning points; If utilize four curve segment to be similar to the curve of overdriving of its correspondence, promptly have three turning points; If utilize five curve segment to be similar to the curve of overdriving of its correspondence, promptly have four turning points, by that analogy.
See also Fig. 5, it is for the GTG value table of comparisons synoptic diagram of overdriving of the preferred embodiment of the present invention.As shown in Figure 5, the curve of overdriving that the GTG value table of comparisons utilizes curve segment to be similar to different initial its correspondences of GTG value because this is overdrived produces, and therefore the interval and the interval value of this initial GTG value might not be identical interval and interval values.Same, interval and interval value that the interval of this target gray scale value and interval value are also not necessarily identical.In other words, the curve characteristic of curve is neither identical because each bar is overdrived, so the overdrive interval of this initial GTG value of curve and the interval of this target gray scale value of each bar is inequality.What wherein this GTG value table of comparisons of overdriving was stored is the coefficient value of the curve segment of each bar curve correspondence.
As shown in Figure 5, have what interval, promptly represent this curve of overdriving to utilize how many linear fragments to be similar in the pairing target gray scale value in arbitrary interval of initial GTG value.
See also Fig. 6, it is the LCD drive g device block schematic diagram of first preferred embodiment of the invention.In this embodiment, set each bar over-drive value curve break (judgepoint) count and the pairing target gray scale value of turning point all identical.
As shown in Figure 6, this LCD drive g device comprises: image input block 110, two dichotomy unit 121,122, frame buffer controller 130, frame buffer 140, over-drive value calculation unit 150, Memory Controller Hub 160, the overdrive table of comparisons 170 and image data-outputting unit 180.This image input block 110 receives view data, and this view data can be gray scale image or coloured image.If this view data is a coloured image, then this view data comprises red (R) look, green (G) look, three kinds of view data of indigo plant (B) look.
Present t1 constantly, this image input block 110 receives current image datas, and this image input block 110 is sent to this dichotomy unit 121 with this current image data.This dichotomy unit 121 has stored the turning point of all initial GTG correspondences, according to this turning point and present input image data, utilizes binary approach to determine the section of this initial GTG value in current image data place.Can calculate the section of this initial GTG value in current image data place via this dichotomy unit 121, this section value corresponding is stored in this section value corresponding among this frame buffer 140 via this frame buffer controller 130.This frame buffer controller 130 is also read the section value corresponding of the initial GTG value in previous view data place of previous moment t0 by this frame buffer 140, be sent to this Memory Controller Hub 160.
The current image data that this dichotomy unit 122 receives from this image input block 110.This dichotomy unit 122 has stored the turning point and the current image data of all target gray scale correspondences, according to this turning point and current image data, utilizes binary approach to determine the section of this current image data place target gray scale value.Can calculate the section of this current image data place target gray scale value via this dichotomy unit 122, this section value corresponding is sent into this Memory Controller Hub 160, this Memory Controller Hub 160 deposits this section value corresponding among the internal memory in.According to the pairing numerical value of section of this current image data place target gray scale value and the section value corresponding at previous view data place, utilize the existing table of comparisons 170 of overdriving, this over-drive value calculation unit 150 is read and sent into to the pairing GTG value of overdriving (OD value).This over-drive value calculation unit 150 receives these current image datas and from this GTG value of overdriving of this table of comparisons 170 of overdriving, this current image data of output of overdriving is to this image data-outputting unit 180.By the output of overdriving of these image data-outputting unit 180 these current image datas of output, to drive liquid crystal panel.
In the above-described embodiments, if this current image data is a coloured image, then this current image data comprises red (R) look, green (G) look, three kinds of view data of indigo plant (B) look, can utilize binary approach to determine three kinds of view data section of the initial GTG value in place respectively respectively at red (R) look, green (G) look, three kinds of view data of indigo plant (B) look.Three numerical value of each section correspondence are stored in each section value corresponding among this frame buffer 140 via this frame buffer controller 130.This frame buffer controller 130 is also read the section value corresponding of the initial GTG value in previous view data place of previous moment t0 by this frame buffer 140, be sent to this Memory Controller Hub 160.
In like manner, three kinds of view data that this dichotomy unit 122 receives from this image input block 110 utilize binary approach to determine the section of three kinds of view data place target gray scale values.Can calculate the section of three kinds of view data place target gray scale values via this dichotomy unit 122, each section value corresponding is sent among this Memory Controller Hub 160.According to three kinds of pairing numerical value of each section of color of this current image data place target gray scale value and each section value corresponding of three kinds of colors at previous view data place, utilize the existing table of comparisons 170 of overdriving, this over-drive value calculation unit 150 is read and sent into to each GTG value of overdriving of pairing three kinds of colors.This over-drive value calculation unit 150 receives these current image datas and from this GTG value of overdriving of this table of comparisons 170 of overdriving, this current image data of output of overdriving is to this image data-outputting unit 180.By the output of overdriving of these image data-outputting unit 180 these current image datas of output, to drive liquid crystal panel.
Suppose that integral body has 32 GTG value curves (OD Curve) of overdriving, and then can utilize 5 (bits) data to represent the section of this initial GTG value in current image data place again.These frame buffer 140 stored data can replace with above-mentioned 5 (bits) data.In like manner, this frame buffer controller 130 is read 5 (bits) data of the section correspondence of the initial GTG value in previous view data place of previous moment t0 by this frame buffer 140, be sent to this Memory Controller Hub 160.This dichotomy unit 122 can calculate the section of this current image data place target gray scale value, can utilize 5 (bits) data to represent the section of this current image data place target gray scale value.5 (bits) data of this section correspondence are sent among this Memory Controller Hub 160.5 bit data according to the section correspondence at pairing 5 bit data of the section of this current image data place target gray scale value and previous view data place, utilize the existing table of comparisons 170 of overdriving, this over-drive value calculation unit 150 is read and sent into to the pairing GTG value of overdriving.This over-drive value calculation unit 150 receives these current image datas and from this GTG value of overdriving of this table of comparisons 170 of overdriving, this current image data of output of overdriving is to this image data-outputting unit 180.By the output of overdriving of these image data-outputting unit 180 these current image datas of output, to drive liquid crystal panel.
See also Fig. 7, it is the LCD drive g device block schematic diagram of second preferred embodiment of the invention.As shown in Figure 7, this LCD drive g device comprises: image input block 210, two dichotomy unit 221,222, frame buffer controller 230, frame buffer 240, the reference position table of comparisons 250, the turning point data table of comparisons 260, over-drive value calculation unit 270, Memory Controller Hub 281,282,283, the overdrive table of comparisons 290 and image data-outputting unit 300.
This image input block 210 receives view data, and this view data can be gray scale image or coloured image.If this view data is a coloured image, then this view data comprises red (R) look, green (G) look, three kinds of view data of indigo plant (B) look.
Present t1 constantly, this image input block 210 receives current image datas, and this image input block 210 is sent to this dichotomy unit 221 with this current image data.This dichotomy unit 221 has stored the turning point of all initial GTG correspondences, according to this turning point and current image data, utilize binary approach to determine the section of this initial GTG value in current image data place, in other words, find the corresponding GTG value curve (OD Curve) of overdriving exactly.Can calculate the section of this initial GTG value in current image data place via this dichotomy unit 221, that is the pairing GTG value curve (OD Curve) of overdriving, this section value corresponding is stored in this section value corresponding among this frame buffer 240 via this frame buffer controller 230.This frame buffer controller 230 is also read the section value corresponding of the initial GTG value in previous view data place of previous moment t0 by this frame buffer 240, be sent to this Memory Controller Hub 281.
Again, suppose that integral body has 32 GTG value curves (OD Curve) of overdriving and is example, then can utilize 5 (bits) data to represent the section of this initial GTG value in current image data place.That is these frame buffer 240 stored data promptly are this 5 bit data.
This 5 bit data that is read by this Memory Controller Hub 281 is input to this reference position table of comparisons 250, as the Input Address (Input Address) of this reference position table of comparisons 250, by these reference position table of comparisons 250 corresponding data content Input Address (Input Address) that promptly is this turning point data table of comparisons 260.Then find all turning point data to the GTG value curve (OD Curve) of should overdriving by this turning point numerical value table of comparisons 260.These all turning point data of overdriving GTG value curve (OD Curve) are sent into this dichotomy unit 222 via this Memory Controller Hub 282.
This dichotomy unit 222 and reception are from this current image data of this image input block 210.All turning points that this dichotomy unit 222 receives from this Memory Controller Hub 282 according to this turning point and current image data, utilize binary approach to determine the section of this current image data place target gray scale value.Can calculate the section of this current image data place target gray scale value via this dichotomy unit 222, this section value corresponding is sent among this Memory Controller Hub 283.This Memory Controller Hub 283 receives the start position data of being found from the section value corresponding of the initial GTG value in previous view data place of this Memory Controller Hub 281 again, and sends among this Memory Controller Hub 283.
Start position data according to the section value corresponding at the pairing numerical value of section of this current image data place target gray scale value and previous view data place, utilize the existing table of comparisons 290 of overdriving, this over-drive value calculation unit 270 is read and sent into to pairing multinomial coefficient.This over-drive value calculation unit 270 receives these current image datas and from this multinomial coefficient of the table of comparisons 290 of overdriving, and calculates this GTG value (ODvalue) of overdriving, and this current image data of output of overdriving is to this image data-outputting unit 300.By the output of overdriving of these image data-outputting unit 300 these current image datas of output, to drive liquid crystal panel.
In the above-described embodiments, if this current image data is a coloured image, then this current image data comprises red (R) look, green (G) look, three kinds of view data of indigo plant (B) look, can be respectively at red (R) look, green (G) look, three kinds of view data of indigo plant (B) look, utilize binary approach to determine three kinds of view data section of the initial GTG value in place respectively, in other words, find the corresponding respectively GTG value curve of overdriving exactly.Three numerical value of each section correspondence are stored in each section value corresponding among this frame buffer 240 via this frame buffer controller 230.This frame buffer controller 230 is also read the section value corresponding of the initial GTG value in previous view data place of previous moment t0 by this frame buffer 240, be sent to this Memory Controller Hub 281.
In like manner, these dichotomy unit 222 receptions are from three kinds of view data of this image input block 210.The target gray scale value that this dichotomy unit 222 receives from all turning point correspondences of this Memory Controller Hub 282 according to the target gray scale value of this turning point correspondence, utilizes binary approach to determine the section of three kinds of view data place target gray scale values.Can calculate the section of three kinds of view data place target gray scale values via this dichotomy unit 222, each section value corresponding is fed among this Memory Controller Hub 283.Start position data according to three kinds of each section value corresponding of color at three kinds of pairing numerical value of each section of color of this current image data place target gray scale value and previous view data place, utilize the existing table of comparisons 290 of overdriving, this over-drive value calculation unit 270 is read and sent into to pairing multinomial coefficient.This over-drive value calculation unit 270 receives this current image data and calculates this GTG value (ODvalue) of overdriving from this multinomial coefficient of overdriving the table of comparisons 290, and this current image data of output of overdriving is to this image data-outputting unit 300.By the output of overdriving of these image data-outputting unit 300 these current image datas of output, to drive liquid crystal panel.
See also Fig. 8, it is the LCD drive method schematic flow sheet of second preferred embodiment of the invention.As shown in Figure 8, moment t1 receives view data at present, and this view data can be gray scale image or coloured image.If this view data is a coloured image, then this view data comprises red (R) look, green (G) look, three kinds of view data of indigo plant (B) look.Buffer has stored the turning point of all initial GTG value correspondences, according to this turning point and current image data, utilize binary approach to determine the section of this initial GTG value in current image data place, in other words, find the corresponding GTG value curve (OD Curve) of overdriving exactly.This section value corresponding is stored among the frame buffer.This reference position table of comparisons is read and be input to this frame buffer controller also with the section value corresponding of the initial GTG value in previous view data place of previous moment t0 by this frame buffer, as the Input Address of this reference position table of comparisons, by this reference position table of comparisons corresponding data content Input Address that promptly is this turning point data table of comparisons.Then find all turning point data to the GTG value curve of should overdriving by this turning point numerical value table of comparisons.According to this turning point and current image data, utilize binary approach to determine the section of this current image data place target gray scale value.Initial GTG position data according to the section value corresponding at the pairing numerical value of section of this current image data place target gray scale value and previous view data place, utilize the existing table of comparisons of overdriving, this over-drive value calculation unit is read and sent into to pairing multinomial coefficient.This over-drive value calculation unit receives this current image data and from the multinomial coefficient of this table of comparisons of overdriving, and calculates this GTG value of overdriving (OD value), and this current image data of output of overdriving is to drive liquid crystal panel.
In the above-described embodiments, if this current image data is a coloured image, then this current image data comprises red (R) look, green (G) look, three kinds of view data of indigo plant (B) look, can be respectively at red (R) look, green (G) look, three kinds of view data of indigo plant (B) look, utilize binary approach to determine the section of three kinds of initial GTG values in the indivedual places of view data, in other words, find the corresponding respectively GTG value curve of overdriving exactly.With three numerical value of each section correspondence through being stored among this frame buffer.
Specific embodiment of the invention described above and diagram can be understood those skilled in the art, yet protection scope of the present invention is not limited to the foregoing description.
Comprehensively above-mentioned, purpose of the present invention fully and is effectively disclosed.The present invention can be appointed by those skilled in the art and executes that the craftsman thinks and be to modify right neither disengaging such as Protector that claims are desired as all.