CN101426312A - Backlight device - Google Patents
Backlight device Download PDFInfo
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- CN101426312A CN101426312A CNA2007101669179A CN200710166917A CN101426312A CN 101426312 A CN101426312 A CN 101426312A CN A2007101669179 A CNA2007101669179 A CN A2007101669179A CN 200710166917 A CN200710166917 A CN 200710166917A CN 101426312 A CN101426312 A CN 101426312A
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Abstract
The present invention relates to a backlight device which comprises a light emitting unit, a voltage converter, a voltage detecting unit, a correcting unit and a feedback control unit, wherein, the light emitting unit is provided with a first connecting end and a second connecting end. The voltage converter converts an input voltage to a rated voltage according to a periodic signal. The voltage detecting unit detects the voltage level between the first connecting end and the second connecting end to generate a measuring voltage. The correcting unit executes gain executes gain correction to the measuring voltage and adjusts the corrected voltage with a scaling for generating a correcting voltage. The feedback control unit outputs a feedback signal according to the correcting voltage. The voltage converter dynamically modifies the periodic signal according to the feedback signal.
Description
Technical field
The invention relates to a kind of back lighting device of display, and particularly relevant for a kind of back lighting device of voltage of dynamic correction driven for emitting lights diode.
Background technology
For present various types of display unit, the main flow commodity that LCD can be present at last.Because LCD has advantages such as high image quality, low consumption electrical power, slim volume production, low voltage drive, volume be little, it is occupied a tiny space on market, such as small-sized Portable TV, picture telephone, shoot with video-corder projector, notebook computer, desktop display and LCD TV etc., all show the importance of LCD.
LCD mainly comprises display panels, module backlight and frame.Wherein, the light source that module backlight produced is colourity and very important factor of brightness of decision LCD.Fig. 1 illustrates the Organization Chart into existing back lighting device 100.Please refer to Fig. 1, back lighting device 100 comprises electric pressure converter 110 and luminescence unit 120a～120n.Wherein, luminescence unit 120a～120n all is electrically connected to electric pressure converter 110, and luminescence unit 120a comprises M light-emitting diode D
11～D
M1, switch SW 1 and constant-current source CS1, M is the integer greater than 0.The internal structure of luminescence unit 120b～120n by that analogy.
In order to be easy to set forth the problem place of existing back lighting device 100, will utilize the local Organization Chart of the existing back lighting device 100 that Fig. 2 illustrates to be illustrated now.Please refer to Fig. 2, electric pressure converter 110 receives an input voltage V by its input
I1After, can be according to its inner periodic signal with this input voltage V
I1Be converted to a rated voltage V
O1, and be sent to luminescence unit 120a.During switch SW 1 conducting in luminescence unit 120a, luminescence unit 120a can be by rated voltage V
O1Drive inner lumination of light emitting diode D
11～D
M1, and adjust light-emitting diode D by its inner constant-current source CS1
11～D
M1Brightness.
Because electric pressure converter 110 can decide rated voltage V according to its inner periodic signal
O1Size, so as periodic signal fixedly time the, rated voltage V
O1Also will fix thereupon.Yet, light-emitting diode D
11～D
M1Forward voltage (forward voltage) can rise and descend along with the temperature of system, that is to say light-emitting diode D
11～D
M1The voltage difference at two ends can diminish.Therefore, unnecessary voltage will be absorbed by switch SW 1, and by the switching of switch SW 1 energy is discharged with the form of heat, causes the waste of the temperature rising and the energy.
For example, with reference to Fig. 2, light-emitting diode D
11One voltage V is forward arranged
11, light-emitting diode D
21One voltage V is forward arranged
12, the rest may be inferred for all the other.In addition, make that the voltage of voltage drop on switch SW 1 is voltage V
SW1, and the voltage of voltage drop on constant-current source CS1 is voltage V
C1, therefore can obtain the first mathematical expression V
O1=V
11+ ...+V
1M+ V
SWith the second mathematical expression V
S=V
SW1+ V
C1Earlier from first mathematical expression, as light-emitting diode D
11～D
M1, temperature makes forward voltage V because rising
11～V
1MDuring decline, because rated voltage V
O1Fix, so voltage V
STo rise thereupon.Again from second mathematical expression, because voltage V
C1Be fixing, so voltage V
SThe part that rises is absorbed by switch SW 1 fully.So, there are many energy will to shed with the form of heat (energy loss of switch is divided into conduction loss and switch cost), cause system temperature to rise and redundant power consumption, therefore the operating efficiency of system also reduces.
Summary of the invention
The invention provides a kind of back lighting device, can improve the forward voltage decline that light-emitting diode Yin Wendu rises and causes itself, make unnecessary voltage absorb, the problem that causes switch temperature to rise by switch.
The invention provides a kind of back lighting device, because the influence that temperature rises and brought can also effectively prevent the rising of redundant power consumption and unit temp, make whole efficiency can obtain to promote except improving light-emitting diode.
The present invention proposes a kind of back lighting device, comprises luminescence unit, electric pressure converter, voltage detection unit, correcting unit and feedback control unit.Wherein, luminescence unit has first link and second link.Electric pressure converter is converted to rated voltage according to the one-period signal with input voltage, and this rated voltage is brought in this luminescence unit of driving by first connection of luminescence unit.
Accept above-mentionedly, voltage detection unit is in order to detect the voltage quasi position on luminescence unit first link and second link, whereby to produce a measurement voltage.Correcting unit is in order to carrying out gain calibration to measuring voltage, and adjusts measurement voltage after the correction with a scaling, whereby to produce a correction voltage.Feedback control unit is exported a feedback signal according to correction voltage, and electric pressure converter will dynamically be revised periodic signal according to this feedback signal.
From another viewpoint, the present invention proposes a kind of back lighting device, comprises N luminescence unit, electric pressure converter, a N voltage detection unit, voltage comparison unit, correcting unit and feedback control unit.Wherein, each unit in N luminescence unit all has first link and second link separately, and N is the integer greater than 0.Electric pressure converter is converted to a rated voltage according to the one-period signal with input voltage, and this rated voltage is brought in each luminescence unit of driving by first connection of each luminescence unit.
Accept above-mentioned, each unit in N voltage detection unit all produces one separately and measures voltage, and i voltage detection unit among N voltage detection unit is in order to the voltage quasi position on two links that detect i luminescence unit, measure voltage to produce i whereby, and above-mentioned mentioned i is an integer and 1 ≦ i ≦ N.Voltage comparison unit is in order to N measurement voltage that voltage detection unit produced relatively, and measures from these according to comparative result and to select one to export as maximum measurement voltage voltages.
On the other hand, correcting unit is in order to carrying out gain calibration to measuring voltage, and adjusts measurement voltage after the correction with a scaling, whereby to produce a correction voltage.Feedback control unit is exported a feedback signal according to correction voltage, and electric pressure converter will dynamically be revised periodic signal according to this feedback signal.
The present invention makes electric pressure converter dynamically revise its inner periodic signal according to a feedback signal because of adopting the design of feedback circuit, to change the rated voltage of output, therefore can effectively improve the shortcoming of prior art, makes the unlikely rising of switch temperature.And, can prevent the rising of redundant power consumption and unit temp by dynamically adjusting rated voltage, make whole efficiency can obtain to promote.
Description of drawings
For above-mentioned purpose of the present invention, feature and advantage can be become apparent, below in conjunction with accompanying drawing the specific embodiment of the present invention is elaborated, wherein:
Fig. 1 illustrates the Organization Chart into existing back lighting device 100.
Fig. 2 illustrates the local Organization Chart into existing back lighting device 100.
Fig. 3 A illustrates and is the Organization Chart according to the back lighting device 300 of one embodiment of the invention.
Fig. 3 B illustrates the Organization Chart that uses the voltage detection unit of another type into back lighting device 300.
Fig. 4 A illustrates and is the Organization Chart according to the back lighting device 400 of another embodiment of the present invention.
Fig. 4 B illustrates the Organization Chart that uses the voltage detection unit of another type into back lighting device 400.
The main element symbol description:
100,300,400: back lighting device
110,320,460: electric pressure converter
120a～120n, 310,410a～410n: luminescence unit
330,380,420a～420n, 480a～480n: voltage detection unit
340,440: correcting unit
350,450: feedback control unit
311,411a: current generating unit
430: voltage comparison unit
D
1～D
M, D
11～D
M1: light-emitting component
C
1, C
2, C
11, C
12: electric capacity
T
1, T
41: transformer
E
1～E
N: diode
SW1, SW31, SW41: switch
CS1, CS31, CS41: constant-current source
S
1, S
11～SN
1: first link
S
2, S
12～S
N2: second link
V
11, V
I3, V
I4: input voltage
V
O1, V
O3, V
O4: rated voltage
V
11～V
1M, V
31～V
3M: voltage forward
V
SW1, V
C1, V
SW3, V
C3, V
S: voltage
VM31, V41a～V41n: measure voltage
VM32, V42: correction voltage
S31, S41: feedback signal
VM41: the maximum voltage that measures
Embodiment
Fig. 3 A illustrates and is the Organization Chart according to the back lighting device 300 of one embodiment of the invention.Please refer to Fig. 3, back lighting device 300 comprises luminescence unit 310, electric pressure converter 320, voltage detection unit 330, correcting unit 340 and feedback control unit 350.Wherein, luminescence unit 310 has the first link S
1With the second link S
2, its first link S
1Electrically connect the output of electric pressure converter 320, and its second link S
2Electrically connect voltage detection unit 330.
Accept above-mentionedly, voltage detection unit 330 is electrically connected at the first link S
1With the second link S
2Between, in order to detecting the voltage quasi position of two links, and produce one according to this and measure voltage VM31.Correcting unit 340 electrically connects voltage detection units 330 and feedback control units 350, in order to carrying out gain calibration to measuring voltage VM31, and adjusts measurement voltage VM31 after the correction with a scaling, and produces a correction voltage VM32 according to this.Feedback control unit 350 electrically connects electric pressure converter 320, exports a feedback signal S31 to electric pressure converter 320 in order to foundation correction voltage VM32.
Further, current generating unit 311 is electrically connected at the second link S of luminescence unit 310
2And between the earth terminal, it comprises switch SW 31 and constant-current source CS31.Wherein, an end of switch SW 31 is electrically connected to the second link S
2, the other end then electrically connects constant-current source CS31, and the other end of constant-current source CS31 is electrically connected to earth terminal.At this, current generating unit 311 is according to the control signal light-emitting component D that regulates and control to flow through
1～D
MElectric current.In other words, switch SW 31 can determine its conducting state according to above-mentioned control signals, the electric current that is provided with the control constant-current source CS31 light-emitting component D that whether flows through
1～D
M
Please continue the A with reference to Fig. 3, electric pressure converter 320 is receiving an input voltage V
I3After, can be according to its inner periodic signal, with input voltage V
I3Amplify or dwindle, its objective is input voltage V
IBe converted to a rated voltage V
O3After switch SW 31 is according to the control signal conducting, the rated voltage V that luminescence unit 301 meetings provide by electric pressure converter 320
O3, drive its inner light-emitting component D
1～D
M, and can regulate and control light-emitting component D by adjusting constant-current source CS31
1～D
MBrightness.
Suppose light-emitting component D
1One voltage V is forward arranged
31, light-emitting component D
MOne voltage V is forward arranged
3M, the rest may be inferred for all the other, and the voltage on the hypothesis switch SW 31 is voltage V
SW3With the voltage on the constant-current source CS31 be voltage V
C3Because light-emitting component D
1～D
MCan Yin Wendu rise and cause its forward voltage descend, so voltage V forward
F1～V
FMDuring decline, voltage detection unit 330 can be obtained the first link S
1With the second link S
2Between the variation of voltage, produce one and measure voltage VM31, and be sent to correcting unit 340.
Correcting unit 340 receive measure voltage VM31 after, can measure voltage VM31 to this and do gain calibration, and adjust measurement voltage VM31 after the correction, and produce a correction voltage VM32 according to this with a scaling.That is to say, obtaining the first link S
1With the second link S
2Between voltage quasi position after, the obtained voltage quasi position of voltage quasi position that correcting unit 340 can be obtained this moment and previous moment subtracts each other, to obtain a voltage variety.Afterwards, correcting unit 340 carries out nonlinear computing to this variable quantity, and then produces correction voltage VM32, and exports feedback control unit 350 to.
After feedback control unit 350 receives correction voltage VM32, can produce a feedback signal S31 according to this correction voltage VM32, and be sent to electric pressure converter 320.That is to say that feedback control unit 350 can carry out the conversion of unit to the correction voltage VM32 that receives, and produces feedback signal S31 whereby.And electric pressure converter 320 can be done correction to the periodic signal of inside according to this feedback signal S31 after receiving feedback signal S31, to change the rated voltage V of output
O3For example, electric pressure converter 320 is originally according to inner periodic signal, with a ratio value convergent-divergent input voltage V
I3Produce rated voltage V
O3, but after receiving feedback signal S31, can or subtract each other with this feedback signal S31 and periodic signal addition, produce a new periodic signal whereby, to revise in order to convergent-divergent input voltage V
I3Ratio value.
At this, the coupling mode of electric pressure converter 320, voltage detection unit 330, correcting unit 340 and feedback control unit 350 can be considered a feedback circuit.By above-mentioned feedback circuit, back lighting device 300 can momentarily be adjusted rated voltage V
O3Size.So, as long as voltage detection unit 330 is obtained light-emitting component D
1～D
MThe variable quantity of forward voltage, just can produce a feedback signal S31 at once and remove to revise periodic signal in the electric pressure converter 320, and then change rated voltage V
O3To cause the voltage V of voltage drop on switch SW 31
SW3Unlikely rising.In addition, light-emitting component D
1～D
MVoltage decline is not linear relationship because of the temperature rising causes forward, and the gain calibration that the voltage of 340 pairs of measurements of correcting unit hereat VM31 is carried out is to adopt nonlinear compute mode, with the demand of compliance with system reality.
What deserves to be mentioned is at this, the voltage detection unit 330 in the back lighting device 300, its framework is not limited only to the above.For instance, Fig. 3 B illustrates the Organization Chart that uses the voltage detection unit of another type into back lighting device 300, and wherein voltage detection unit 380 is in order to replace the voltage detection unit 330 among Fig. 3 A.Please refer to Fig. 3 B, voltage detection unit 380 comprises transformer T
1Wherein, transformer T
1Have primary side and secondary side, first end of primary side is electrically connected to the first link S of luminescence unit 310
1, second end of primary side is electrically connected to the second link S of luminescence unit 310
2, and first end of secondary side is in order to produce to measure voltage VM31, and second end of secondary side is electrically connected to earth terminal.
Accept above-mentionedly, utilize above-mentioned transformer T
1Coupling mode, voltage detection unit 380 can reach the effect of the voltage detection unit of being made up of electric capacity 330.Therefore, have the knack of this operator and should know, the voltage detection unit in the back lighting device 300 is not limited to the cited form of the various embodiments described above, and the user also can utilize an Amplifier Design circuit to reach the effect of voltage detection unit.
Fig. 4 A illustrates and is the Organization Chart according to the back lighting device 400 of another embodiment of the present invention.Please refer to Fig. 4 A, back lighting device 400 comprises N luminescence unit 410a～410n, electric pressure converter 460, N voltage detection unit 420a～420n, voltage comparison unit unit 430, correcting unit 440 and feedback control unit 450, and N is the integer greater than 0.Wherein, luminescence unit 410a～410n has one first link and one second link separately, and for example luminescence unit 410a has the first link S
11With the second link S
12, luminescence unit 410b has the first link S
N1With the second link S
N2, the rest may be inferred for all the other.The first link S of all luminescence units
11～S
N1The common output that electrically connects electric pressure converter 460, and its second link S
12～S
N2Then be electrically connected to corresponding voltage detection unit 420a～420n separately.
Accept above-mentionedly, voltage detection unit 420a～420n is electrically connected at the first corresponding link S separately
11～S
N1With the second link S
12～S
N2Between, for example voltage detection unit 420a is electrically connected at the first link S
11With the second link S
12Between, voltage detection unit 420n is electrically connected at the first link S
N1With the second link S
N2Between.In addition, voltage detection unit 420a～420n is in order to detecting the voltage quasi position of two links, and produces one separately and measure voltage.For example, voltage detection unit 420a is electrically connected at the first link S
11With the second link S
12Between, in order to detecting the voltage quasi position of two links, and produce one according to this and measure voltage V41a.Voltage comparison unit 430 electrically connects voltage detection unit 420a～420n, in order to relatively measuring the magnitude of voltage of voltage V41a～V41n, and therefrom selects an output as a maximum voltage VM41 that measures according to comparative result.
Correcting unit 440 electrically connects voltage comparison unit 430 and feedback control unit 450, and feedback control unit 450 electrically connects electric pressure converter 460, and its effect is same as the previously described embodiments, so be not repeated in this.
Please continue the A with reference to Fig. 4, the framework of the back lighting device 400 of present embodiment and effect and the foregoing description are very similar, only different be in voltage comparison unit and luminescence unit, voltage detection unit how much.Therefore, now the spirit of present embodiment will be described at these unit (410a～410n, 420a～420n, 430).
In luminescence unit 410a～410n, each unit all comprises a M light-emitting component and a current generating unit, and M is the integer greater than 0, and for example luminescence unit 420a comprises light-emitting component D
11～D
M1With current generating unit 411a, by that analogy, the internal structure of luminescence unit 410b～410n.At this, current generating unit 411a comprises switch SW 41 and constant-current source CS41, and it is according to control signal light-emitting component D that regulates and control to flow through
11～D
M1Electric current.In other words, switch SW 41 can determine its conducting state according to above-mentioned control signals, the electric current that is provided with the control constant-current source CS41 light-emitting component D that whether flows through
11～D
M1
And among voltage detection unit 420a～420n, each unit all comprises two electric capacity, and this two electric capacity is connected in series mutually, and is electrically connected between corresponding first link and second link.For example, voltage detection unit 420a comprises capacitor C
11With C
12, capacitor C wherein
11First end be electrically connected to the first link S
11, second end electrically connects capacitor C
12First end, and capacitor C
12Second end be electrically connected to the second link S
12, and first end measures voltage V41a in order to produce one.By that analogy, the internal structure of voltage detection unit 420b～420n and its coupling mode.
In Fig. 4 A, luminescence unit 420a～420n all may make forward, and voltage descends because temperature rises, so each voltage detection unit can be obtained the measurement voltage of a correspondence,, N voltage detection unit 420a～420n measure voltage V41a～V41n so will having N.Therefore, voltage comparison unit 430 will receive the magnitude of voltage that measures voltage V41a～V41n and relatively measure voltage V41a～V41n, selects an output as a maximum voltage VM41 that measures from measure voltage V41a～V41n according to comparative result afterwards.For example, if voltage comparison unit 430 includes only diode E
1With E
2, and diode E
1Receive 2 volts measurement voltage V41a, and diode E
2When receiving 1 volt measurement voltage V41b, diode E then
1Cathode terminal will obtain 2 volts voltage, make diode E
21 volt of received voltage can't pass through, and is 2 volts so the maximum of utilizing this principle to produce measures voltage.
After obtaining maximum measurement voltage VM41, ensuing action is with similar to the above embodiments.Correcting unit 440 can be done gain calibration and proportional zoom to this maximum voltage VM41 that measures, to produce a correction voltage V42 and to be sent to feedback control unit 450, feedback control unit 450 then produces a feedback signal S41 according to this correction voltage V42, remove to revise the periodic signal of electric pressure converter 460, change rated voltage V whereby
O4
What deserves to be mentioned is at this, the voltage detection unit 420a～420n in the back lighting device 400, its framework is not limited only to the above.For instance, Fig. 4 B illustrates the Organization Chart that uses the voltage detection unit of another type into back lighting device 400, and wherein voltage detection unit 480a～480n is in order to replace the voltage detection unit 420a～420n among Fig. 4 A.Please refer to Fig. 4 B, in voltage detection unit 480a～480n, each voltage detection unit all comprises a transformer.Wherein, transformer T
41Have primary side and secondary side, first end of primary side and second end are electrically connected to the first link S of luminescence unit 410a respectively
11With the second link S
12, and first end of secondary side is in order to produce to measure voltage V41a, and second end of secondary side is electrically connected to earth terminal.By that analogy, the internal structure of voltage detection unit 480b～480n and its coupling mode.
Accept above-mentionedly, utilize above-mentioned transformer T
41Coupling mode, voltage detection unit 480a～480n can reach the effect of the voltage detection unit 420a～420n that is made up of electric capacity.Therefore, be familiar with this operator and should know, the voltage detection unit in the back lighting device 400 is not limited to the cited form of the various embodiments described above.
In sum, the present invention adopts the feedback circuit design, make electric pressure converter revise its inner periodic signal according to a feedback signal, whereby to change the rated voltage of its output, make the unlikely rising of switch temperature, therefore can prevent the rising of redundant power consumption and unit temp, and can make the state of light-emitting component more stable, make the whole efficiency of system obtain to promote.In addition, the present invention can be applicable to electric pressure converter framework arbitrarily, therefore can be used widely, promotes competitiveness of product.
Though the present invention discloses as above with preferred embodiment; right its is not in order to qualification the present invention, any those skilled in the art, without departing from the spirit and scope of the present invention; when can doing a little modification and perfect, so protection scope of the present invention is when with being as the criterion that claims were defined.
Claims (13)
1. back lighting device is characterized in that comprising:
One luminescence unit has one first link and one second link;
One electric pressure converter is converted to a rated voltage in order to foundation one-period signal with an input voltage, and this rated voltage connects by first of this luminescence unit and brings in that to drive this luminescence unit luminous;
One voltage detection unit in order to first link that detects this luminescence unit and the voltage quasi position on second link, measures voltage and produce one according to this;
One correcting unit in order to this measurement voltage is carried out gain calibration, and is adjusted this measurement voltage after the correction with a scaling, and is produced a correction voltage according to this; And
One feedback control unit, in order to export a feedback signal according to this correction voltage, wherein this electric pressure converter is dynamically revised this periodic signal according to this feedback signal.
2. back lighting device as claimed in claim 1 is characterized in that, this voltage detection unit comprises:
One first electric capacity, its first end is electrically connected to first link of this luminescence unit, and its second end is in order to produce this measurement voltage; And
One second electric capacity, its first end is electrically connected to second end of this first electric capacity, and its second end is electrically connected to second link of this luminescence unit.
3. back lighting device as claimed in claim 1 is characterized in that, this voltage detection unit comprises:
One transformer, have a primary side and a secondary side, first end of this primary side is electrically connected to first link of this luminescence unit, second end of this primary side is electrically connected to second link of this luminescence unit, and first end of this secondary side is in order to produce this measurement voltage, and second end of this secondary side is electrically connected to an earth terminal.
4. back lighting device as claimed in claim 1 is characterized in that, this luminescence unit comprises:
A most light-emitting component, those light-emitting components are serially connected between first link and second link of this luminescence unit mutually; And
One current generating unit is electrically connected between second link and an earth terminal of this luminescence unit, in order to the electric current of those light-emitting components of regulating and control to flow through according to a control signal.
5. back lighting device as claimed in claim 4 is characterized in that, this current generating unit comprises:
One switch, its first end is electrically connected to second link of this luminescence unit, and this switch determines its conducting state according to this control signal; And
One constant-current source is electrically connected between second end and this earth terminal of this switch.
6. back lighting device as claimed in claim 4 is characterized in that, those light-emitting components are light-emitting diode.
7. back lighting device is characterized in that comprising:
N luminescence unit, each those luminescence unit have one first link and one second link separately, and N is the integer greater than 0;
One electric pressure converter is converted to a rated voltage in order to foundation one-period signal with an input voltage, and this rated voltage connects by first of each those luminescence unit and brings in that to drive those luminescence units luminous;
N voltage detection unit measures voltage in order to produce N, and wherein i voltage detection unit be in order to the voltage quasi position on two links that detect i luminescence unit, and produce i measurement voltage according to this, and wherein, i is integer and 1 ≦ i ≦ N;
One voltage comparison unit in order to relatively those measure the magnitude of voltage of voltage, and is selected one according to comparative result and is exported as the maximum voltage that measures from those measurement voltages;
One correcting unit carries out gain calibration in order to this maximum is measured voltage, and this maximum of adjusting after the correction with a scaling measures voltage, and produces a correction voltage according to this; And
One feedback control unit, in order to export a feedback signal according to this correction voltage, wherein this electric pressure converter is dynamically revised this periodic signal according to this feedback signal.
8. back lighting device as claimed in claim 7 is characterized in that, this voltage comparison unit comprises:
N diode, wherein the anode of i diode is electrically connected to i voltage detection unit, and the negative electrode of each those diode is electrically connected to this correcting unit jointly.
9. back lighting device as claimed in claim 7 is characterized in that, i voltage detection unit comprises:
One first electric capacity, its first end is electrically connected to first link of i luminescence unit, and its second end measures voltage in order to produce i; And
One second electric capacity, its first end is electrically connected to second end of this first electric capacity, and its second end electrically is connected to second link of i luminescence unit.
10. back lighting device as claimed in claim 7 is characterized in that, i voltage detection unit comprises:
One transformer, have a primary side and a secondary side, first end of this primary side is electrically connected to first link of i luminescence unit, second end of this primary side is electrically connected to second link of i luminescence unit, and first end of this secondary side measures voltage in order to produce i, and second end of this secondary side is electrically connected to an earth terminal.
11. back lighting device as claimed in claim 7 is characterized in that, i luminescence unit comprises:
A most light-emitting component, those light-emitting components are serially connected between first link and second link of i luminescence unit mutually; And
One current generating unit is electrically connected between second link and an earth terminal of i luminescence unit, in order to the electric current of those light-emitting components of regulating and control to flow through according to a control signal.
12. back lighting device as claimed in claim 11 is characterized in that, this current generating unit comprises:
One switch, its first end is electrically connected to second link of i luminescence unit, and this switch determines its conducting state according to this control signal; And
One constant-current source is electrically connected between second end and this earth terminal of this switch.
13. back lighting device as claimed in claim 11 is characterized in that, those light-emitting components are light-emitting diode.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNA2007101669179A CN101426312A (en) | 2007-10-29 | 2007-10-29 | Backlight device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNA2007101669179A CN101426312A (en) | 2007-10-29 | 2007-10-29 | Backlight device |
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| Publication Number | Publication Date |
|---|---|
| CN101426312A true CN101426312A (en) | 2009-05-06 |
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ID=40616585
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNA2007101669179A Pending CN101426312A (en) | 2007-10-29 | 2007-10-29 | Backlight device |
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| CN101895194B (en) * | 2009-05-21 | 2012-11-28 | 华映视讯（吴江）有限公司 | Voltage converter, backlight module control system and control method thereof |
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| CN106163027A (en) * | 2015-03-26 | 2016-11-23 | 苏州璨宇光学有限公司 | Light source drive device and light source driving method |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN101895194B (en) * | 2009-05-21 | 2012-11-28 | 华映视讯（吴江）有限公司 | Voltage converter, backlight module control system and control method thereof |
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Application publication date: 20090506 |