CN101500361A - LED driving apparatus and driving method thereof - Google Patents
LED driving apparatus and driving method thereof Download PDFInfo
- Publication number
- CN101500361A CN101500361A CNA200910118228XA CN200910118228A CN101500361A CN 101500361 A CN101500361 A CN 101500361A CN A200910118228X A CNA200910118228X A CN A200910118228XA CN 200910118228 A CN200910118228 A CN 200910118228A CN 101500361 A CN101500361 A CN 101500361A
- Authority
- CN
- China
- Prior art keywords
- duty ratio
- current
- emitting diode
- duty
- setting signal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Abstract
The invention discloses an LED (light emitting diode) driving device and a driving method thereof. The LED driving device comprises a duty-cycle setting unit, a direct-current setting unit, a control unit and an LED driving circuit, wherein the duty-cycle setting unit is used for outputting a duty-cycle setting signal; the direct-current setting unit is used for outputting a direct-current setting signal; the control unit is used for receiving the duty-cycle setting signal and the direct-current setting signal and outputting a direct-current control signal and a duty-cycle control signal according to the duty-cycle setting signal and the direct-current setting signal; and the LED driving circuit is used for driving at least one LED according to the direct-current control signal and the duty-cycle control signal. The LED driving device and the driving method thereof can effectively adjust the current value and duty cycle of the LED driving current, thereby not only improving the work efficiency of the LED, but also accurately controlling the average on-state current of the LED.
Description
Technical field
The present invention relates to a kind of light emitting diode drive device and driving method thereof, or rather, relate to a kind of light emitting diode drive device and driving method thereof that is applied to panel.
Background technology
(Light Emitting Diode, good characteristic such as LED) low power consumption, operating temperature be lower is employed at present widely because light-emitting diode.
For example, most small-medium size panel, all be to utilize 3～10 LED, adopt the mode of polyphone to be used as back light, (Personal DigitalAssistant, keyboard back light PDA) are also mostly to be to utilize the usefulness of LED as floor light, adds European Union for mercuryless requirement for mobile phone or personal digital assistant even, therefore for the Driving technique of LED more of new generation, also just considerably expected by market.
Most portable product, the dimming function that all designed backlight for panel, that is to say, under the situation of no Alternating Current Power Supply, standby mode or the like, the capital is adjusted brightness backlight, reduce power consumption, prolong the service time of battery, yet existing LED type of drive have following shortcoming:
1. the light-emitting diode drive current is a fixed value, can't adjust automatically with behaviour in service.Because light-emitting diode is controlled luminous intensity by the size of current that flows through light-emitting diode, so the type of drive of fixed current value has limited its convenience that uses especially.
2. the electric current when drive current is fixed as high-high brightness, the electric current of use high-high brightness when non-high-high brightness can make LED act on inefficient district.In sum, present LED driving method has its defective, and a kind of better LED driving method is real to be expected by industry.
Summary of the invention
The invention provides a kind of light emitting diode drive device and driving method thereof, come driven for emitting lights diode better by current value and the duty ratio (duty cycle) of adjusting the light-emitting diode drive current.
One embodiment of light emitting diode drive device of the present invention comprises a duty ratio setup unit, a direct current setup unit, a control unit and a LED driving circuit.This duty ratio setup unit is in order to export a duty ratio setting signal.This direct current setup unit is in order to export a direct current setting signal.This control unit is in order to receiving this duty ratio setting signal and this direct current setting signal, and exports a dc control signal and a duty cycle control signal according to this duty ratio setting signal and this direct current setting signal.This LED driving circuit is in order to drive at least one light-emitting diode according to this dc control signal and this duty cycle control signal.
One embodiment of LED driving method of the present invention, this driving method comprises: provide one first drive current in the cycle very first time, in order to drive a light-emitting diode, this first drive current has one first duty ratio and one first current value; And provide one second drive current in second time cycle that is connected in this cycle very first time, in order to drive a light-emitting diode, this second drive current has one second duty, one second current value when, and wherein this first current value is not equal to this second current value and this first duty ratio is not equal to this second duty ratio.
One embodiment of the method for driven for emitting lights diode of the present invention, this driving method comprises: a duty ratio setting signal is provided; One direct current setting signal is provided; Receive this duty ratio setting signal and this direct current setting signal to a control unit; Export a dc control signal and duty cycle control signal to a LED driving circuit via this control unit; With drive at least one light-emitting diode according to this dc control signal and this duty cycle control signal.
The present invention can effectively adjust the current value and the duty ratio of light-emitting diode drive current, allows the LED operating efficiency improve and makes the average conducting electric current of LED can be precisely controlled.
Above summarize technical characterictic of the present invention and advantage quite widely, make the present invention's detailed description hereinafter be obtained preferable understanding.Other technical characterictic and the advantage that constitute the target of claim of the present invention will be described in hereinafter.Those of ordinary skills should be appreciated that, can quite easily utilize the notion that hereinafter discloses to can be used as modification with specific embodiment or design other structure or technology and realize the purpose identical with the present invention.Those of ordinary skills should be appreciated that also this class equivalence construction can't break away from the appended the spirit and scope of the present invention that claim defined.
Description of drawings
By reference above stated specification and following accompanying drawing, technical characterictic of the present invention and advantage are obtained to be understood fully.
The systematic square frame schematic diagram of the light emitting diode drive device of Fig. 1 illustration one embodiment of the invention;
Fig. 2 A and Fig. 2 B be the oscillogram that control unit received and exported in the light emitting diode drive device of illustration one embodiment of the invention respectively; And
The systematic square frame schematic diagram of the control unit in the light emitting diode drive device of Fig. 3 illustration one embodiment of the invention.
Wherein, description of reference numerals is as follows:
100 light emitting diode drive devices
102 light-emitting diodes
104 duty ratio setup units
106 direct current setup units
108 control units
110 LED driving circuit
302 duty ratios and current operator unit
308 electric current exponent number setup units
Embodiment
Please refer to Fig. 1, the systematic square frame schematic diagram of the light emitting diode drive device of its illustration one embodiment of the invention.This light emitting diode drive device 100 is in order to driven for emitting lights diode 102, and wherein this light emitting diode drive device 100 comprises duty ratio setup unit 104, direct current setup unit 106, control unit 108 and LED driving circuit 110.Duty ratio setup unit 104 gives control unit 108 in order to export a direct current setting signal for control unit 108 and direct current setup unit 106 in order to export a duty ratio setting signal; 108 of control units are according to this duty ratio setting signal that is received and this direct current setting signal is exported a dc control signal and a duty cycle control signal is given LED driving circuit 110, and 110 of LED driving circuit drive this light-emitting diode according to this received dc control signal and this duty cycle control signal.
Please refer to Fig. 2 A and Fig. 2 B.The oscillogram that control unit received in the light emitting diode drive device of Fig. 2 A illustration one embodiment of the invention; This duty ratio setting signal can (pulse width modulation, PWM) signal, voltage, digital signal etc. be to be example with pulse bandwidth turn-on cycle signal at this embodiment for the pulse bandwidth turn-on cycle; The oscillogram that control unit in the light emitting diode drive device of Fig. 2 B illustration one embodiment of the invention is exported.In this oscillogram, the setting exponent number of output current is 4, and promptly output current can be maximum output current Imax, 0.75 times maximum output current 0.75Imax, 0.5 times maximum output current 0.5Imax or 0.25 times maximum output current 0.25Imax.The transverse axis representative is time shaft in the diagram, and what the longitudinal axis was represented is size of current.Please earlier with reference to Fig. 2 A, in period of time T 1, be 100% from the duty ratio of duty ratio setup unit 104 Input Control Elements 108, be IMAX from the maximum current of direct current setup unit 106 Input Control Elements 104; In period of time T 2, be 75% from the duty ratio of duty ratio setup unit 104 Input Control Elements 108, and be IMAX from the maximum current of direct current setup unit 106 Input Control Elements 104; In period of time T 3, be 85% from the duty ratio of duty ratio setup unit 104 Input Control Elements 108, and be IMAX from the maximum current of direct current setup unit 106 Input Control Elements 104; In period of time T 4, be 50% from the duty ratio of duty ratio setup unit 104 Input Control Elements 108, and be IMAX from the maximum current of direct current setup unit 106 Input Control Elements 104; In period of time T 5, be 30% from the duty ratio of duty ratio setup unit 104 Input Control Elements 108, and be IMAX from the maximum current of direct current setup unit 106 Input Control Elements 104.Please continue the B with reference to Fig. 2, in period of time T 1 ', the duty ratio of exporting to light-emitting diode driver element 110 from control unit 108 is 100%, and electric current is IMAX; In period of time T 2 ', the duty ratio of exporting to light-emitting diode driver element 110 from control unit 108 is 100%, and electric current is 0.75IMAX; In period of time T 3 ', the duty ratio of exporting to light-emitting diode driver element 110 from control unit 108 is 85%, and electric current is IMAX; In period of time T 4 ', the duty ratio of exporting to light-emitting diode driver element 110 from control unit 108 is 100%, and electric current is 0.5IMAX; In period of time T 5 ', the duty ratio of exporting to light-emitting diode driver element 110 from control unit 108 is 60%, and electric current is 0.5IMAX.It should be noted that the duty ratio that control unit 108 is received can equate also can not wait with electric current with the duty ratio of electric current and output.For example be respectively 75% and IMAX at the received duty ratio of period of time T 2 control units 108 and electric current, different with 0.75IMAX with its duty ratio with electric current 100% in period of time T 2 ' output.The duty ratio that control unit 108 is received and the duty ratio and the electric current of electric current and output satisfy following relationship:
Duty ratio * output current-----equation (1) of the duty ratio * institute received current=output that is received
Make it satisfy equation (1) by duty ratio and the output current of adjusting output, can make LED operate in adaptively in the higher zone of operating efficiency.The present invention can allow the LED operating efficiency improve by the mode of collocation DC driven and the driving of pulse bandwidth turn-on cycle; Set and can promote efficient by adjusting direct current in addition, and by adjust the logical cycle of pulse bandwidth then accurately control flows cross the average current of LED.
Please refer to Fig. 3.Fig. 3 is the systematic square frame schematic diagram of the control unit 108 in the light emitting diode drive device of illustration one embodiment of the invention.Control unit 108 comprises electric current exponent number setup unit 308, in order to determine an electric current exponent number; A dc control signal and a duty cycle control signal are exported in order to the electric current exponent number that determined according to the lowest high-current value that is determined by direct current setup unit 106, by electric current exponent number setup unit 308 and by the duty ratio setting signal that duty ratio setup unit 104 transmits in duty ratio and current operator unit 302.Wherein electric current exponent number setup unit can be set the electric current exponent number arbitrarily according to actual demand.Is example at this with 4 rank electric current exponent numbers (1～4), and an explanation is done in the operation of duty ratio and current operator unit 302.When the duty ratio of the duty ratio setting signal that received representative is 0≤duty ratio≤25,, the electric current exponent number is set to 1, and it is 1 that dc control signal is set to
*Lowest high-current value IMAX/4; When the duty ratio of the duty ratio setting signal that received representative is 25＜duty ratio≤50,, the electric current exponent number is set to 2, and dc control signal is set to 2
*Lowest high-current value IMAX/4=lowest high-current value IMAX/2; When the duty ratio of the duty ratio setting signal that received representative is 50＜duty ratio≤75,, the electric current exponent number is set to 3, and it is 3 that dc control signal is set to
*Lowest high-current value IMAX/4; When the duty ratio of the duty ratio setting signal that received representative is 75＜duty ratio≤100,, the electric current exponent number is set to 4, and dc control signal is set to lowest high-current value IMAX.For example, the duty ratio of representing when received duty ratio setting signal is 80%, and then the electric current exponent number is 4, and dc control signal is 4
*Lowest high-current value IMAX/4=lowest high-current value IMAX, can get duty cycle control signal according to equation (1) is 80%.For example, the duty ratio setting signal of representing when received duty ratio setting signal is 25%, and then the electric current exponent number is 1, and dc control signal is 1
*Imax/4=0.25Imax, can get duty cycle control signal according to equation (1) is 100%.Though at this is to be 4 to be that example is done explanation with the electric current exponent number, yet the electric current exponent number can be not limited thereto according in fact needing to do setting.
Next B simultaneously please sees figures.1.and.2.During period of time T 2 ' and T3 ', light emitting diode drive device 100 provides one first drive current in period of time T 2 ', and in order to driven for emitting lights diode 102, this first drive current has duty ratio 100% and current value 0.75IMAX; Next light emitting diode drive device 100 provides one second drive current in a time period T 3 ' that is connected in period of time T 2 ', and in order to driven for emitting lights diode 102, this second drive current has duty ratio 80% and current value I MAX; During period of time T 2 ' and T3 ', the duty ratio of first drive current is greater than the duty ratio of second drive current; And the current value of first drive current is less than the current value of second drive current.
During period of time T 3 ' and T4 ', light emitting diode drive device 100 provides one second drive current in period of time T 3 ', and in order to driven for emitting lights diode 102, this second drive current has duty ratio 80% and current value I MAX; Next light emitting diode drive device 100 provides one the 3rd drive current in a time period T 4 ' that is connected in period of time T 3 ', has duty ratio 100% and current value 0.5IMAX in order to driven for emitting lights diode 102, the three drive currents; During period of time T 3 ' and T4 ', the duty ratio of second drive current is less than the duty ratio of the 3rd drive current; And the current value of second drive current is greater than the current value of the 3rd drive current.
Drive And Its Driving Method by above-mentioned light-emitting diode, can effectively adjust the current value and the duty ratio of light-emitting diode drive current, allowing the LED operating efficiency improve and make the average conducting electric current of LED can be precisely controlled, be the drive unit and the driving method of a preferred light-emitting diode.
Technology contents of the present invention and technical characterstic disclose as above, however those of ordinary skills should be appreciated that, in the spirit and scope of the invention that does not deviate from claims and defined, instruction of the present invention and disclose and can do all replacements and modification.For example, above many technologies of Jie Shiing can diverse ways be implemented or are replaced with other technology, perhaps adopt the combination of above-mentioned two kinds of modes.
Claims (12)
1. light emitting diode drive device comprises:
One duty ratio setup unit is in order to export a duty ratio setting signal;
One direct current setup unit is in order to export a direct current setting signal;
One control unit in order to receiving this duty ratio setting signal and this direct current setting signal, and is exported a dc control signal and a duty cycle control signal according to this duty ratio setting signal and this direct current setting signal; With
One LED driving circuit is in order to drive at least one light-emitting diode according to this dc control signal and this duty cycle control signal.
2. light emitting diode drive device as claimed in claim 1, wherein this direct current setting signal is in order to set the lowest high-current value that control unit is exported.
3. light emitting diode drive device as claimed in claim 1, wherein this duty ratio setting signal comprises the information of the duty ratio of the electric current that control unit receives.
4. light emitting diode drive device as claimed in claim 1, wherein this control unit further comprises:
One electric current exponent number setup unit is in order to determine an electric current exponent number; With
One duty ratio and current operator unit are in order to export this dc control signal and this duty cycle control signal according to this lowest high-current value and this electric current exponent number.
5. light emitting diode drive device as claimed in claim 4, wherein the product of the duty ratio of this duty cycle control signal representative and this dc control signal equals the duty ratio of this duty ratio setting signal representative and the product of this direct current setting signal.
6. LED driving method comprises:
Provide one first drive current in the cycle very first time, in order to drive a light-emitting diode, this first drive current has one first duty ratio and one first current value; With
Provide one second drive current in second time cycle that is connected in this cycle very first time, in order to drive a light-emitting diode, this second drive current has one second duty, one second current value when, and wherein this first current value is not equal to this second current value and this first duty ratio is not equal to this second duty ratio.
7. LED driving method as claimed in claim 6, wherein this first current value is greater than this second current value.
8. LED driving method as claimed in claim 6, wherein this first current value is less than this second current value.
9. LED driving method as claimed in claim 6, wherein this first duty ratio is less than this second duty ratio.
10. LED driving method as claimed in claim 8, wherein this second duty ratio is greater than this second duty ratio.
11. the method for a driven for emitting lights diode comprises:
One duty ratio setting signal is provided;
One direct current setting signal is provided;
Receive this duty ratio setting signal and this direct current setting signal to a control unit;
Export a dc control signal and duty cycle control signal to a LED driving circuit via this control unit; With
Drive at least one light-emitting diode according to this dc control signal and this duty cycle control signal.
12. LED driving method as claimed in claim 11, wherein this driving at least the step of this light-emitting diode further comprise:
Provide one first drive current in the cycle very first time, in order to drive this light-emitting diode; With
Provide one second drive current in second time cycle that is connected in this cycle very first time, in order to drive this light-emitting diode.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200910118228XA CN101500361B (en) | 2009-03-03 | 2009-03-03 | LED driving apparatus and driving method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200910118228XA CN101500361B (en) | 2009-03-03 | 2009-03-03 | LED driving apparatus and driving method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101500361A true CN101500361A (en) | 2009-08-05 |
| CN101500361B CN101500361B (en) | 2012-07-04 |
Family
ID=40947171
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN200910118228XA Active CN101500361B (en) | 2009-03-03 | 2009-03-03 | LED driving apparatus and driving method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101500361B (en) |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101902861A (en) * | 2010-08-10 | 2010-12-01 | 友达光电股份有限公司 | LED driving method and LED driving circuit |
| CN102014554A (en) * | 2010-09-28 | 2011-04-13 | 深圳市明微电子股份有限公司 | Method and device for adjusting drive current |
| CN102568385A (en) * | 2010-12-13 | 2012-07-11 | 奇美电子股份有限公司 | Driving device, LED (light emitting diode) driving device and driving methods thereof |
| CN103118454A (en) * | 2011-09-23 | 2013-05-22 | 英飞凌科技股份有限公司 | Digital switching converter control |
| US8541956B2 (en) | 2010-07-23 | 2013-09-24 | Au Optronics Corp. | Light emitting diode driving method and driving circuit |
| US8604720B2 (en) | 2010-09-01 | 2013-12-10 | Au Optronics Corp. | Light emitting diode driving method |
| US8638049B2 (en) | 2010-03-09 | 2014-01-28 | Chimei Innolux Corporation | Driving device, light emitting diode driving device and driving method |
| CN104869685A (en) * | 2014-02-25 | 2015-08-26 | 群光电能科技股份有限公司 | Output current changeable LED driver and method thereof |
| CN105448233A (en) * | 2014-08-26 | 2016-03-30 | 上海和辉光电有限公司 | OLED pixel driving method and organic light-emitting diode display device |
| WO2019000157A1 (en) * | 2017-06-26 | 2019-01-03 | 华为技术有限公司 | Method for controlling backlight power of liquid crystal display and liquid crystal display |
-
2009
- 2009-03-03 CN CN200910118228XA patent/CN101500361B/en active Active
Cited By (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8638049B2 (en) | 2010-03-09 | 2014-01-28 | Chimei Innolux Corporation | Driving device, light emitting diode driving device and driving method |
| US8541956B2 (en) | 2010-07-23 | 2013-09-24 | Au Optronics Corp. | Light emitting diode driving method and driving circuit |
| CN101902861A (en) * | 2010-08-10 | 2010-12-01 | 友达光电股份有限公司 | LED driving method and LED driving circuit |
| CN101902861B (en) * | 2010-08-10 | 2013-09-11 | 友达光电股份有限公司 | LED driving method and LED driving circuit |
| US8604720B2 (en) | 2010-09-01 | 2013-12-10 | Au Optronics Corp. | Light emitting diode driving method |
| CN102014554A (en) * | 2010-09-28 | 2011-04-13 | 深圳市明微电子股份有限公司 | Method and device for adjusting drive current |
| CN102014554B (en) * | 2010-09-28 | 2013-07-10 | 深圳市明微电子股份有限公司 | Method and device for adjusting drive current |
| CN102568385A (en) * | 2010-12-13 | 2012-07-11 | 奇美电子股份有限公司 | Driving device, LED (light emitting diode) driving device and driving methods thereof |
| CN103118454A (en) * | 2011-09-23 | 2013-05-22 | 英飞凌科技股份有限公司 | Digital switching converter control |
| US9292028B2 (en) | 2011-09-23 | 2016-03-22 | Infineon Technologies Ag | Digital switching converter control |
| CN103118454B (en) * | 2011-09-23 | 2016-06-01 | 英飞凌科技股份有限公司 | Numeral switching converter control |
| CN104869685A (en) * | 2014-02-25 | 2015-08-26 | 群光电能科技股份有限公司 | Output current changeable LED driver and method thereof |
| CN105448233A (en) * | 2014-08-26 | 2016-03-30 | 上海和辉光电有限公司 | OLED pixel driving method and organic light-emitting diode display device |
| WO2019000157A1 (en) * | 2017-06-26 | 2019-01-03 | 华为技术有限公司 | Method for controlling backlight power of liquid crystal display and liquid crystal display |
Also Published As
| Publication number | Publication date |
|---|---|
| CN101500361B (en) | 2012-07-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101500361B (en) | LED driving apparatus and driving method thereof | |
| CN101547540B (en) | Backlight controller, method for driving light sources, and display system | |
| US7498754B2 (en) | Architecture for driving multiple loads at constant current | |
| CN201667742U (en) | LED backlight driving device of light emitting diode and liquid crystal display | |
| US8952622B2 (en) | Light emitting diode driving apparatus, driving method of light emitting diode, and computer-readable recording medium | |
| US9241377B2 (en) | LED backlight driving circuit, LCD device, and method for driving the LED backlight driving circuit | |
| US8159148B2 (en) | Light emitting diode light source module | |
| TWI405500B (en) | Light emitting diode driving device and driving method thereof | |
| JP2011035368A (en) | Light-emitting diode driver and driving method of the same | |
| CN201504346U (en) | OLED illumination lamp or back light source driving controller | |
| CN104333933A (en) | Light emitting diode driving device and light emitting diode illumination system applying same | |
| CN104505030A (en) | Backlight drive circuit, driving method thereof and liquid-crystal display device | |
| CN102622986A (en) | Light emitting diode (LED) backlight drive circuit, backlight module, and liquid crystal display device | |
| CN111048045A (en) | Light emitting diode driving device and light emitting diode backlight module | |
| CN103533722A (en) | LED dimming lamp device | |
| CN103024977B (en) | Light emitting diode driving circuit | |
| CN101170850A (en) | Light source driving circuit | |
| CN202004436U (en) | Light emitting diode (LED) driving circuit and short circuit protection circuit thereof | |
| CN103379706A (en) | Driving circuit | |
| CN102568385A (en) | Driving device, LED (light emitting diode) driving device and driving methods thereof | |
| US8692476B2 (en) | Boost circuit for LED backlight driver circuit | |
| CN102682707A (en) | Energy saving device of light emitting diode | |
| CN100553392C (en) | Light-emitting device | |
| CN215222542U (en) | Low-cost dimming circuit | |
| CN213755057U (en) | Multi-path self-adaptive constant current driving circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |