CN102568385A - Driving device, LED (light emitting diode) driving device and driving methods thereof - Google Patents
Driving device, LED (light emitting diode) driving device and driving methods thereof Download PDFInfo
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- CN102568385A CN102568385A CN2010106007701A CN201010600770A CN102568385A CN 102568385 A CN102568385 A CN 102568385A CN 2010106007701 A CN2010106007701 A CN 2010106007701A CN 201010600770 A CN201010600770 A CN 201010600770A CN 102568385 A CN102568385 A CN 102568385A
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Abstract
The invention discloses a driving device, an LED (light emitting diode) driving device and driving methods thereof. The LED driving device comprises a driving unit and multiple selection units; the driving unit is used for generating driving signals for driving an LED; the selection units are coupled with the driving unit, and respectively correspond to different current values; and the driving unit selects one of the selection units according to the work period of a first PWM (pulse width modulation) signal, takes the current values corresponding to the selected selection units as the current values of the driving signals, and generates the work period of a second PWM signal according to the work period of the first PWM signal as the work period of the driving signals. Therefore, the electric power consumption on the display brightness of the LED can be reduced.
Description
Technical field
The invention relates to a kind of drive unit, and particularly relevant for a kind of light emitting diode drive device and driving method thereof.
Background technology
LCD has gently, thin, short, little, low-power consumption and do not have the advantage that the width of cloth is penetrated pollution, thus LCD be widely used, especially on the portable apparatus, as PDA(Personal Digital Assistant), notebook computer (notebook, NB) and digital camera.Because the display panels of LCD itself can't be luminous, thus below display panels, must provide a backlight module so that light source to be provided, and then reach the function of demonstration.And in order to reach lightening effect, portable apparatus is generally and uses the light source of light emitting diode as backlight module.
When portable electronic devices uses civil power as power supply, then need not consider the electrical problems of device, thereby backlight module can provide brighter light source, to promote the display effect of portable electronic devices.Otherwise,, can reduce brightness of backlight module to reduce power consumption if portable electronic devices during as power supply, has long service time in order to make portable electronic devices with battery.Generally speaking, the adjustment of backlight module brightness can be accomplished through the responsibility cycle of adjustment drive signal.In other words, the responsibility cycle of drive signal is 100% when using civil power as if portable electronic devices, and the responsibility cycle of drive signal can be 50% when then portable electronic devices used battery.Whereby, the electric power in the time of can reducing portable electronic devices use battery is to promote the service time of portable electronic devices.
Summary of the invention
The present invention provides a kind of drive unit, light emitting diode drive device and driving method thereof, can reduce the power consumption of diode displaying brightness.
The present invention proposes a kind of light emitting diode drive device, and it comprises driver element and a plurality of selected cell.Driver element is in order to produce drive signal with the driven for emitting lights diode.These selected cells couple driver element, and the corresponding different respectively current value of these selected cells.Driver element is selected one of them of these selected cells according to work period of first pulse-width signal, and with the current value of the pairing current value of selecteed selected cell as drive signal.And; Driver element produces second pulse-width signal according to the work period of first pulse-width signal; And with the work period as drive signal work period of second pulse-width signal, wherein the work period of second pulse-width signal is more than or equal to the work period of first pulse-width signal.
In one embodiment of this invention, light emitting diode drive device more comprises a plurality of switches, and these switches are respectively coupled between these selected cells and the driver element.These switches according to selecting signal conducting one of them, one of them electrically connects driver element to select these selected cells.
In one embodiment of this invention, above-mentioned driver element is obtained according to the table of comparisons and is selected the pairing current value of signal, selects one of them of these selected cells of the pairing current value selection of signal with foundation.
In one embodiment of this invention; Above-mentioned driver element is obtained the pairing current value of work period of first pulse-width signal and the work period of second pulse-width signal according to the table of comparisons or the ALU that counts, and selects these selected cells one of them according to pairing current value of the work period of first pulse-width signal.
The present invention proposes also a kind of driving method of light emitting diode.This driving method comprises: provide drive signal with the driven for emitting lights diode; A plurality of current values are provided; Receive first pulse-width signal; Select one of them current value of these current values as drive signal according to the work period of first pulse-width signal; Work period according to first pulse-width signal produces second pulse-width signal, and wherein the work period of second pulse-width signal is more than or equal to the work period of first pulse-width signal; With work period work period of second pulse-width signal as drive signal.
In one embodiment of this invention; The step of one of them of these current values of work period selection of above-mentioned foundation first pulse-width signal comprises according to the work period generation one of first pulse-width signal selects signal, and selects these current values one of them according to the selection signal.
In one embodiment of this invention; Above-mentioned according to selecting signal to select one of them step of these current values to comprise to obtain to select the pairing current value of signal according to the table of comparisons, and according to selecting the pairing current value of signal to select one of them of these current values.
In one embodiment of this invention, above-mentioned selection signal carries out obtaining after the computing according to the work period of first pulse-width signal for obtaining according to the table of comparisons perhaps.
In one embodiment of this invention, the second above-mentioned pulse-width signal carries out obtaining after the computing according to the work period of first pulse-width signal for obtaining according to the table of comparisons perhaps.
In one embodiment of this invention; Work period of above-mentioned foundation first pulse-width signal selects one the step wherein of these current values to comprise the pairing current value of work period of obtaining first pulse-width signal according to the table of comparisons, and to select one of them of these current values according to pairing current value of the work period of first pulse-width signal.
The present invention proposes a kind of drive unit in addition, and in order to drive at least one light emitting diode, drive unit comprises pwm unit, signal generation unit, selected cell and current generating unit.Selected cell couples the signal generation unit.Current generating unit couples selected cell.In the time will changing the brightness of above-mentioned lumination of light emitting diode, pwm unit receives first pulse-width signal and produces second pulse-width signal, and the signal generation unit also receives first pulse-width signal and produce the selection signal.And selected cell receives to be selected signal and produces electric current decision signal, and current generating unit received current decision signal also produces drive current.Drive unit drives above-mentioned light emitting diode according to the work period and the drive current of second pulse-width signal.
In one embodiment of this invention, above-mentioned selected cell is above resistance or register.
In one embodiment of this invention; Above-mentioned pwm unit is obtained second pulse-width signal of the work period of corresponding first pulse-width signal according to the table of comparisons, perhaps carry out computing to produce second pulse-width signal according to the work period of first pulse-width signal.
In one embodiment of this invention, above-mentioned signal generation unit is obtained the selection signal of the work period of corresponding first pulse-width signal according to the table of comparisons, perhaps carries out computing according to the work period of first pulse-width signal and selects signal to produce.
In one embodiment of this invention, the ratio of the work period of the work period of the second above-mentioned pulse-width signal and first pulse-width signal is inversely proportional to the ratio of drive current and predetermined current value.
Based on above-mentioned; Drive unit of the present invention, light emitting diode drive device and driving method thereof; Because the luminescence efficiency of light emitting diode can promote when electric current descended; Therefore the mode that the current value that sees through the adjustment drive signal is adjusted brightness can reduce sets required electric current of brightness and the consumption of therefore saving electric power.
Description of drawings
For let above-mentioned purpose of the present invention, feature and advantage can be more obviously understandable, elaborate below in conjunction with the accompanying drawing specific embodiments of the invention, wherein:
Figure 1A is for coupling the circuit diagram of light emitting diode according to the light emitting diode drive device of first embodiment of the invention.
It is 100% and the waveform synoptic diagram of work period of 50% o'clock adjustment drive signal SDR that Figure 1B and Fig. 1 C are respectively in display brightness.
Fig. 1 D is the luminescence efficiency synoptic diagram of light emitting diode corresponding to the different electric flow valuve.
Fig. 1 E for the present invention operation and traditional wide arteries and veins modulation operations in the power consumption synoptic diagram of different brightness.
Fig. 1 F is the circuit diagram of the signal processing unit 110 of Figure 1A.
Fig. 2 is for coupling the circuit diagram of light emitting diode according to the light emitting diode drive device of second embodiment of the invention.
Fig. 3 is for coupling the circuit diagram of light emitting diode according to the light emitting diode drive device of third embodiment of the invention.
Fig. 4 is for coupling the circuit diagram of light emitting diode according to the light emitting diode drive device of fourth embodiment of the invention.
Fig. 5 is for coupling the circuit diagram of light emitting diode according to the light emitting diode drive device of fifth embodiment of the invention.
Fig. 6 is for coupling the circuit diagram of light emitting diode according to the light emitting diode drive device of sixth embodiment of the invention.
Fig. 7 is the process flow diagram according to the driving method of the light emitting diode of one embodiment of the invention.
The main element symbol description:
100,200,300,400,500,600: light emitting diode drive device
110,410: signal processing unit
111: pwm unit
113: the signal generation unit
120,210,310,420,510,610: driver element
PWM1, PWM2, PWM3: pulse-width signal
SC1, SC2: select signal
SCD: electric current decision signal
SDR: drive signal
D1～Dn: light emitting diode
VCC: system voltage
SW1～SW9: switch
R1～R9: resistance
W1～W3: curve
S710, S720, S730, S740, S750: step
Embodiment
Figure 1A is for coupling the circuit diagram of light emitting diode according to the light emitting diode drive device of first embodiment of the invention.Please with reference to Figure 1A; Light emitting diode drive device 100 comprises that (is example at this with resistance R 1～R9 for signal processing unit 110, driver element 120, switch SW 1～SW9 and a plurality of selected cell; But can be a plurality of registers in other embodiments; And do not limit the present invention with this), and light emitting diode drive device 100 can be used as the backlight module of display.Signal processing unit 110 produces the second pulse-width signal PWM2 and selects signal SC1 according to the first pulse-width signal PWM1; The first pulse-width signal PWM1 luminance signal that can transmit for the outside wherein, and the work period of the second pulse-width signal PWM2 is more than or equal to the work period of the first pulse-width signal PWM1.And; Signal processing unit 110 can according to the table of comparisons search or according to work period of the first pulse-width signal PWM1 carry out computing obtain the corresponding first pulse-width signal PWM1 the second pulse-width signal PWM2 work period and select signal SC1, wherein above-mentioned computing can be accomplished via the ALU that counts.
Switch SW 1～SW9 makes one of them present conducting according to selecting signal SC 1; So that one of them of resistance R 1～R9 electrically connects driver element 120, wherein resistance R 1～R9 is in order to the control light emitting diode D1 that flows through, D2; ...; The current value of Dn, that is resistance R 1～R9 is in order to the current value of decision drive signal SDR, and the resistance of resistance R 1～R9 neither with.
With on the other hand, switch SW 1～SW9 makes one of them present conducting according to selecting signal SC1, so that one of them of resistance R 1～R9 electrically connects driver element 120, and the generation electric current that the resistance that couples with driver element 120 can be corresponding determines signal S
CDDriver element 120 can be according to electric current decision signal S
CDProduce drive current (that is current value of decision drive signal SDR), this moment, driver element 120 can be considered a current generating unit.In addition, whether driver element 120 can provide drive current to light emitting diode D1 according to the work period decision of the second pulse-width signal PWM2, D2 ..., Dn produces drive signal SDR according to this.Light emitting diode D1, D2 ..., Dn is then luminous or not luminous according to the decision of the pressure reduction between system voltage VCC and drive signal SDR, that is light emitting diode D1, D2 ..., Dn receives the driving of drive signal SDR and appears luminous or not luminous.
It is 100% and the waveform synoptic diagram of work period of 50% o'clock adjustment drive signal SDR that Figure 1B and Fig. 1 C are respectively in display brightness.Generally speaking, backlight module brightness decided for the work period that sees through drive signal SDR, and the electric current of drive signal SDR is fixed as a predetermined current value (for example being 20mA).With reference to Figure 1B, for instance, be 100% if set the brightness of backlight module demonstration please, then the electric current of drive signal SDR is 20mA, and the work period of drive signal SDR is 100% (that is direct current).With reference to Fig. 1 C, be 50% if set the brightness of backlight module demonstration please, then the electric current of drive signal SDR is maintained 20mA, and the work period of drive signal SDR becomes 50%.Under general state; The electric current of drive signal SDR can present a fixed value, but after the relation to its luminescence efficiency of light-emitting diode measurement and electric current, finds when current density reduces; Luminescence efficiency increases on the contrary, and the forward forward voltage of light emitting diode also can descend.
Fig. 1 D is the luminescence efficiency synoptic diagram of light emitting diode corresponding to the different electric flow valuve.Please with reference to Fig. 1 D, curve W1 is the luminous efficiency curve of light emitting diode.With curve W1 is example, and when current value was 20mA, the luminescence efficiency of light emitting diode was 92lm/W (lumens/watt), and when current value was 10mA, the luminescence efficiency of light emitting diode was 106lm/W.In other words, be that 20mA changes to 10mA at current value, the luminescence efficiency of light emitting diode can improve 15% on the contrary.Fig. 1 E for the present invention operation and traditional wide arteries and veins modulation operations in the power consumption synoptic diagram of different brightness.Please with reference to Fig. 1 E, curve W2 adjusts the power-consumption curve of brightness for the work period of tradition adjustment drive signal SDR, and the current value that curve W3 adjusts drive signal SDR for the present invention is adjusted the power-consumption curve of brightness.Shown in curve W2 and W3, when showing same brightness, the work period that the power of adjusting brightness with the current value of adjustment drive signal SDR can be lower than adjustment drive signal SDR is adjusted the power of brightness.Therefore, see through the mode of adjustment drive signal SDR electric current, its power required when showing same brightness can be lower than the mode of adjustment drive signal SDR work period.
Therefore, in the present embodiment, the work period of the second pulse-width signal PWM2 is fixed as 100%, so that drive signal SDR presents the direct current shape, and the current value of the corresponding different brightness of resistance R 1～R9 difference.For instance, if brightness is the unit of an adjustment with 10%, and the scope of adjustment is 20%～100%, and the brightness that then resistance R 1～R9 is corresponding respectively is assumed to be 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100%.That is to say; Signal processing unit 110 can select to produce corresponding selection signal SC1 according to the work period of the first pulse-width signal PWM1; So that driver element 120 electrically connects the resistance of corresponding brightness among resistance R 1～R9, and the work period of the corresponding second pulse-width signal PWM2 that produces can be 100%.Wherein, The variation of the work period of the first pulse-width signal PWM1 can be user's adjustment or adjusts because of the system power supply state variation; And when using civil power as power supply; Adjustable brightness range is assumed to be 20%～100%, and when using battery as power supply, adjustable brightness range is assumed to be 20%～50%.
In addition, if brightness is the unit of an adjustment with 1%, and the scope of adjustment is 20%～100%, then can increase to 81 by corresponding resistance, and the corresponding different brightness of each resistance.Then driver element 120 can electrically connect the resistance of the work period of the corresponding first pulse-width signal PWM1 according to selection signal SC1, so that light emitting diode presents corresponding brightness.Whereby, the current value that can see through adjustment drive signal SDR is adjusted brightness, reduces with this and sets required electric current of brightness and the consumption of therefore saving electric power.
What deserves to be mentioned is; In other embodiments; Signal processing unit 110 can be integrated in the time schedule controller of display; Therefore time schedule controller can produce the second pulse-width signal PWM2 and select signal SC1 according to the first pulse-width signal PWM1, work period and the current value of the drive signal SDR that is produced with this control drive unit 120.
Fig. 1 F is the circuit diagram of the signal processing unit 110 of Figure 1A.Please with reference to Fig. 1 F, in the present embodiment, signal processing unit 110 comprises pwm unit 111 and signal generation unit 113.Pwm unit 111 receives the first pulse-width signal PWM1 to produce the second pulse-width signal PWM2.Signal generation unit 113 receives the first pulse-width signal PWM1 and selects signal SC1 to produce.Wherein pwm unit 111 can be searched or carries out the work period that computing obtains the second pulse-width signal PWM2 of the corresponding first pulse-width signal PWM1 according to work period of the first pulse-width signal PWM1 according to the table of comparisons.Likewise, signal generation unit 113 also can be searched or carries out the selection signal SC1 that computing obtains the corresponding first pulse-width signal PWM1 according to work period of the first pulse-width signal PWM1 according to the table of comparisons.Wherein, above-mentioned computing can be accomplished via the ALU that counts.
Fig. 2 is for coupling the circuit diagram of light emitting diode according to the light emitting diode drive device of second embodiment of the invention.Please with reference to Figure 1A and Fig. 2; Its difference is that switch SW 1～SW9 is integrated among the driver element 210 of light emitting diode drive device 200; Therefore driver element 210 can according to select signal SC1 select resistance R 1～R9 one of them, with the current value of decision drive signal SDR.Whereby, the pairing brightness of the may command diode displaying first pulse-width signal PWM1.
Fig. 3 is for coupling the circuit diagram of light emitting diode according to the light emitting diode drive device of third embodiment of the invention.Please with reference to Figure 1A and Fig. 3; Its difference is that switch SW 1～SW9 and signal processing unit 110 all are integrated among the driver element 310 of light emitting diode drive device 300; Therefore driver element 310 can according to the work period of the first pulse-width signal PWM1 select resistance R 1～R9 one of them, with the current value of decision drive signal SDR.Wherein, driver element 310 can see through the current value that the table of comparisons obtained the work period of the corresponding first pulse-width signal PWM1, more according to this current value select corresponding same electrical flow valuve or similar current value resistance R 1～R9 one of them.According to above-mentioned, in the inside of driver element 310, driver element 310 can produce the second pulse-width signal PWM2 according to the first pulse-width signal PWM1, and with the work period as drive signal SDR work period of the second pulse-width signal PWM2.
Fig. 4 is for coupling the circuit diagram of light emitting diode according to the light emitting diode drive device of fourth embodiment of the invention.Please with reference to Figure 1A and Fig. 4; In the present embodiment; Light emitting diode drive device 400 is divided into a plurality of sections with the brightness that shows; To set drive signal SDR according to the different brightness section is different current values, and the adjustment of brightness in each section then realizes through the work period of adjustment drive signal SDR.For instance; The brightness 0%～100% that shows is divided into 0%～20%, 20%～50% and 50%～100% 3 section; The current value of in section 0%～20%, setting drive signal SDR can be corresponding 20% brightness, and the current value of in section 20%～50%, setting drive signal SDR can be corresponding 50% brightness, the current value of setting drive signal SDR can be corresponding 100% brightness in section 50%～100%.
Therefore, present embodiment keeps resistance R 1, R4 and the R9 in switch SW 1, SW4, SW9 and the above-mentioned resistance in the above-mentioned switch, and signal processing unit 410 is similar in appearance to signal processing unit 110, and driver element 420 is similar in appearance to driver element 120.Wherein, the quantity of brightness section and scope can be changed according to deviser's demand, and each brightness section set the pairing brightness of electric current of drive signal SDR can be greater than the upper limit brightness value of each brightness section, and can be the preferable brightness value of luminous power.If the work period of the first pulse width signal PWM1 is 60%, that is representes that brightness to display is 60%.At this moment, select signal SC2 can make switch SW 9 conductings, so that the current value of drive signal SDR still is the predetermined current value, and the work period of the 3rd pulse width signal PWM3 can be identical with the work period of the first pulse width signal PWM1 and be 60%.Therefore, the current value of drive signal SDR is the predetermined current value, and the work period of drive signal SDR is 60%.
If the work period of the first pulse width signal PWM1 is 40%, that is representes that brightness to display is 40%.At this moment, select signal SC2 can make switch SW 4 conductings, so that the current value of drive signal SDR is the current value of corresponding brightness 50%, and the work period of the 3rd pulse width signal PWM3 can double the work period of the first pulse width signal PWM1 and be 80%.Therefore, the current value of drive signal SDR is the current value of corresponding brightness 50%, and the work period of drive signal SDR is 80%.
If the work period of the first pulse width signal PWM1 is 10%, that is representes that brightness to display is 10%.At this moment, select signal SC2 can make switch SW 1 conducting, so that the current value of drive signal SDR is the current value of corresponding brightness 20%, and the work period of the 3rd pulse width signal PWM3 can be five times in the work period of the first pulse width signal PWM1 and be 50%.Therefore, the current value of drive signal SDR is the current value of corresponding brightness 20%, and the work period of drive signal SDR is 50%.According to above-mentioned, the ratio of the work period of the work period of the 3rd pulse-width signal PWM3 and the first pulse-width signal PWM1 is inversely proportional to the current value of drive signal SDR and the ratio of predetermined current value.Whereby, smaller or equal to 50% o'clock, meeting was because when the electric current of drive signal SDR is lower than predetermined current in the brightness that shows, the luminescence efficiency of light emitting diode can improve, and then reduced the consumption of electric power.
Fig. 5 is for coupling the circuit diagram of light emitting diode according to the light emitting diode drive device of fifth embodiment of the invention.Please with reference to Fig. 4 and Fig. 5; Its difference is that switch SW 1, SW4, SW9 are integrated among the driver element 510 of light emitting diode drive device 500; Therefore driver element 510 can according to select signal SC2 select resistance R 1, R4, R9 one of them, with the current value of decision drive signal SDR.
Fig. 6 is for coupling the circuit diagram of light emitting diode according to the light emitting diode drive device of sixth embodiment of the invention.Please with reference to Fig. 4 and Fig. 6; Its difference is that switch SW 1, SW4, SW9 and signal processing unit 410 all are integrated among the driver element 610 of light emitting diode drive device 600; Therefore driver element 610 can according to the work period of the first pulse width signal PWM1 select resistance R 1, R4, R9 one of them, with the current value of decision drive signal SDR.Wherein, driver element 610 can see through the current value that the table of comparisons obtained the work period of the corresponding first pulse width signal PWM1, more according to this current value select corresponding same electrical flow valuve or similar current value resistance R 1, R4, R9 one of them.And the ratio of the work period of the work period of drive signal SDR and the first pulse-width signal PWM1 is inversely proportional to the current value of drive signal SDR and the ratio of predetermined current value.
According to above-mentioned, can converge whole is the driving method of a light emitting diode.Fig. 7 is the process flow diagram according to the driving method of the light emitting diode of one embodiment of the invention.Please, in this driving method, can provide drive signal, and a plurality of current values (step S720) are provided, wherein the corresponding different brightness of these current values with driven for emitting lights diode (step S710) with reference to Fig. 7.Then; Receive first pulse-width signal (step S730); And select one of them current value (step S740) of above-mentioned current value according to work period of first pulse-width signal as drive signal, simultaneously according to work period (step S750) of the work period decision drive signal of first pulse-width signal.Wherein, in this driving method, step S730～750 can not stop to carry out, to adjust the current value and the work period of drive signal according to first pulse-width signal at that time.In addition, the details of each step can then repeat no more at this with reference to the explanation of above-mentioned light emitting diode drive device 100～600.
In sum; Light emitting diode drive device of the present invention and driving method thereof; Because the luminescence efficiency of light emitting diode can promote when electric current descended; Therefore the mode that the current value that sees through the adjustment drive signal is adjusted brightness can reduce sets required electric current of brightness and the consumption of therefore saving electric power.And, can the brightness that show be divided into a plurality of sections, couple the quantity of the selected cell of driver element with minimizing.
Though the present invention discloses as above with preferred embodiment; Right its is not that any those skilled in the art are not breaking away from the spirit and scope of the present invention in order to qualification the present invention; When can doing a little modification and perfect, so protection scope of the present invention is when being as the criterion with what claims defined.
Claims (18)
1. light emitting diode drive device comprises:
One driver element is in order to produce a drive signal with the driven for emitting lights diode; And
A plurality of selected cells couple this driver element, the current value that said selected cell is corresponding different respectively;
Wherein, This driver element is selected one of them of said selected cell according to the work period of one first pulse-width signal; And with the current value of the pairing current value of selecteed selected cell as this drive signal; And this driver element produces one second pulse-width signal according to the work period of this first pulse-width signal; And with the work period as this drive signal work period of this second pulse-width signal, wherein the work period of this second pulse-width signal is more than or equal to the work period of this first pulse-width signal.
2. light emitting diode drive device as claimed in claim 1 is characterized in that, more comprises:
A plurality of switches are respectively coupled between said selected cell and this driver element, said switch select signal according to this and conducting one of them, one of them electrically connects this driver element to select said selected cell.
3. light emitting diode drive device as claimed in claim 1 is characterized in that, this driver element is obtained the pairing current value of this selection signal according to comparison list, to select one of them of said selected cell according to the pairing current value of this selection signal.
4. light emitting diode drive device as claimed in claim 1 is characterized in that, the ratio of the work period of the work period of this second pulse-width signal and this first pulse-width signal is inversely proportional to the current value of this drive signal and the ratio of a predetermined current value.
5. light emitting diode drive device as claimed in claim 1; It is characterized in that; This driver element is obtained the pairing current value of work period of this first pulse-width signal and the work period of second pulse-width signal according to comparison list or an ALU that counts, and selects said selected cell one of them according to pairing current value of the work period of this first pulse-width signal.
6. light emitting diode drive device as claimed in claim 1 is characterized in that said selected cell is respectively more than one resistance or register.
7. the driving method of a light emitting diode comprises:
Provide a drive signal with the driven for emitting lights diode;
A plurality of current values are provided;
Receive one first pulse-width signal;
Select one of them current value of said current value as this drive signal according to the work period of this first pulse-width signal;
Work period according to this first pulse-width signal produces one second pulse-width signal, and wherein the work period of this second pulse-width signal is more than or equal to the work period of this first pulse-width signal; And
With work period work period of this second pulse-width signal as this drive signal.
8. the driving method of light emitting diode as claimed in claim 7 is characterized in that, selects one of them step of said current value to comprise according to the work period of this first pulse-width signal:
Work period according to this first pulse-width signal produces a selection signal; And
Select one of them of said current value according to this selection signal.
9. the driving method of light emitting diode as claimed in claim 8 is characterized in that, selects one of them step of said current value to comprise according to this selection signal:
Obtain the pairing current value of this selection signal according to comparison list; And
Select one of them of said current value according to the pairing current value of this selection signal.
10. the driving method of light emitting diode as claimed in claim 8 is characterized in that, this selection signal carries out obtaining after the computing according to the work period of this first pulse-width signal for obtaining perhaps according to comparison list.
11. the driving method of light emitting diode as claimed in claim 7 is characterized in that, this second pulse-width signal carries out obtaining after the computing according to the work period of this first pulse-width signal for obtaining perhaps according to comparison list.
12. the driving method of light emitting diode as claimed in claim 7; It is characterized in that the ratio of the work period of the work period of this second pulse-width signal and this first pulse-width signal is inversely proportional to the current value of this drive signal and the ratio of a predetermined current value.
13. the driving method of light emitting diode as claimed in claim 7 is characterized in that, selects one of them step of said current value to comprise according to the work period of this first pulse-width signal:
Obtain the pairing current value of work period of this first pulse-width signal according to comparison list; And
To select one of them of said current value according to pairing current value of the work period of this first pulse-width signal.
14. a drive unit in order to drive at least one light emitting diode, comprising:
One pwm unit;
One signal generation unit;
One selected cell couples this signal generation unit; And
One current generating unit couples this selected cell;
Wherein, In the time will changing the brightness of above-mentioned lumination of light emitting diode; This pwm unit receives one first pulse-width signal and produces one second pulse-width signal; Select signal and this signal generation unit also receives this first pulse-width signal and produce one; This selected cell receives this selection signal and produces electric current decision signal, and this current generating unit receives this electric current decision signal and produces a drive current, and this drive unit drives above-mentioned light emitting diode according to the work period of this second pulse-width signal with this drive current.
15. drive unit as claimed in claim 14 is characterized in that, this selected cell is above resistance or register.
16. drive unit as claimed in claim 14; It is characterized in that; This pwm unit is obtained this second pulse-width signal to work period that should first pulse-width signal according to comparison list, perhaps carries out computing to produce this second pulse-width signal according to the work period of this first pulse-width signal.
17. drive unit as claimed in claim 14; It is characterized in that; This signal generation unit is obtained this selection signal to work period that should first pulse-width signal according to comparison list, perhaps carries out computing to produce this selection signal according to the work period of this first pulse-width signal.
18. drive unit as claimed in claim 14 is characterized in that, the ratio of the work period of the work period of this second pulse-width signal and this first pulse-width signal is inversely proportional to the ratio of this drive current and a predetermined current value.
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| CN2010106007701A CN102568385A (en) | 2010-12-13 | 2010-12-13 | Driving device, LED (light emitting diode) driving device and driving methods thereof |
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| CN2010106007701A CN102568385A (en) | 2010-12-13 | 2010-12-13 | Driving device, LED (light emitting diode) driving device and driving methods thereof |
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| CN2010106007701A Pending CN102568385A (en) | 2010-12-13 | 2010-12-13 | Driving device, LED (light emitting diode) driving device and driving methods thereof |
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| CN (1) | CN102568385A (en) |
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| CN105962922A (en) * | 2016-04-19 | 2016-09-28 | 矽力杰半导体技术(杭州)有限公司 | Photoelectric sensor, photoelectric detection method and heart rate detection equipment making use of photoelectric sensor |
| CN107146582A (en) * | 2017-06-14 | 2017-09-08 | 昆山龙腾光电有限公司 | Backlight driver and its driving method |
| CN114724510A (en) * | 2022-01-07 | 2022-07-08 | 友达光电股份有限公司 | Display device and driving method thereof |
| US12148379B2 (en) * | 2022-01-07 | 2024-11-19 | AUO Corporation | Display device and driving method thereof |
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| CN107146582B (en) * | 2017-06-14 | 2019-09-13 | 昆山龙腾光电有限公司 | Backlight driver and its driving method |
| CN114724510A (en) * | 2022-01-07 | 2022-07-08 | 友达光电股份有限公司 | Display device and driving method thereof |
| CN114724510B (en) * | 2022-01-07 | 2023-12-19 | 友达光电股份有限公司 | Display device and driving method thereof |
| US12148379B2 (en) * | 2022-01-07 | 2024-11-19 | AUO Corporation | Display device and driving method thereof |
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Application publication date: 20120711 |