CN101236726A - LCD device, light modulation circuit and its method - Google Patents
LCD device, light modulation circuit and its method Download PDFInfo
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- CN101236726A CN101236726A CNA2007100079579A CN200710007957A CN101236726A CN 101236726 A CN101236726 A CN 101236726A CN A2007100079579 A CNA2007100079579 A CN A2007100079579A CN 200710007957 A CN200710007957 A CN 200710007957A CN 101236726 A CN101236726 A CN 101236726A
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Abstract
The present invention discloses a light modulation circuit and a method thereof, which can be applied in a backlight module of a prior liquid crystal display devices to determine a reference current by changing a reference voltage value and a detection resistor value, and a light emitting unit determines the presented brightness according to the reference current, therefore a variable impedance unit increases the impedance of the loop of the light emitting unit to facilitate the load current of the light emitting unit to be decreased to the reference current when the load current of the light emitting unit is greater than the reference current; reversely, the variable impedance unit decreases the impedance of the loop of the light emitting unit to facilitate the load current of the light emitting unit to be increased to the reference current when the load current of the light emitting unit is smaller than the reference current; thereby controlling the load current value to be close to the reference current value so as to present the predetermined brightness of the light emitting unit.
Description
Technical field
The present invention relates to many lighting tube brightness are adjusted in a kind of backlight liquid crystal display module light adjusting circuit and method, particularly relate to a kind of light adjusting circuit and the method that can carry out the brightness adjustment at the fluorescent tube in the backlight liquid crystal display module.
Background technology
In recent years, because the size of display panels (LCD panel) is done bigger and bigger, so (for example: cold-cathode tube) number will be many more for the fluorescent tube of the area source that is provided at the backlight module of display panels (for example being direct type backlight module), and in order effectively to control its cost of manufacture and number of parts, the technology that many fluorescent tubes parallel connection (promptly be arranged parallel to each other and form) is used is just arisen at the historic moment.
Yet, because the characteristic error of each fluorescent tube itself is big, and also different and variant because of the machine sheet material matter of fluorescent tube arrangement mode and backlight module of the leakage current between each fluorescent tube and backlight module, so can cause each lamp tube current difference of flowing through, and cause the brightness disproportionation that display panels presents (that is some block is dark or some block brighter), so the current balance type of controlling between its each fluorescent tube just becomes the key that influences LCD picture quality quality.
Fig. 1 shows existing circuit diagram in order to the light adjusting circuit that reaches the multi-light tube current balance.Please refer to Fig. 1, in circuit Figure 100 of light adjusting circuit, comprise many fluorescent tube L
1～L
8, a plurality of high-tension transformer T
1～T
8, a plurality of capacitor C
1～C
8, and a plurality of current transformer CT
1～CT
7Wherein, high-tension transformer T
1～T
8Pass through capacitor C
1～C
8With fluorescent tube L
1～L
8Connect, and current transformer CT
1～CT
7Then be configured in each fluorescent tube L
1～L
8Between.
As high-tension transformer T
1～T
8Primary side receive the driving signal V that anti-transverter (Inverter) is exported
DAfter, can be at high-tension transformer T
1～T
8Primary side produce drive current and each fluorescent tube L that flows through
1～L
8Drive current utilize current transformer CT again
1～CT
7Reach current balance type, so each fluorescent tube L
1～L
7Luminous brightness meeting identical, so can be so that the brightness that display panels presented is more even.Yet, existing employed current transformer CT
1～CT
7Because of area occupied is big, and can't adjust,, and use elastic space little so not only cost of manufacture is higher at single fluorescent tube.
Summary of the invention
In view of this, the purpose of this invention is to provide a kind of light adjusting circuit and method, it can be adjusted at single fluorescent tube in the backlight liquid crystal display module, so can solve prior art because of adopting the shortcoming that current transformer caused, so can reach and use that elastic space is big, footprint area is little, and advantage such as cost of manufacture is cheap.
Another object of the present invention provides a kind of LCD, it is by light adjusting circuit of the present invention is applied in wherein, except the advantage of the light adjusting circuit that can reach the invention described above, and can be so that the brightness that display panels presented is more even, to realize promoting the picture quality that LCD was presented.
Based on above-mentioned and other purpose, the invention provides a kind of light adjusting circuit, it is suitable for controlling the brightness of luminescence unit in the backlight liquid crystal display module, and this light adjusting circuit comprises detecting unit, comparing unit, and the variableimpedance unit.Wherein, detecting unit is electrically connected first end of luminescence unit, in order to the detection electric current of each luminescence unit of flowing through, and converts thereof into and exports after detecting voltage.Comparing unit is electrically connected detecting unit, compares in order to a detection voltage and the reference voltage that detecting unit is exported, and the output controlling signal.The variableimpedance unit is electrically connected second end of comparing unit and luminescence unit, and the controlling signal that this variableimpedance unit is exported according to comparing unit is first impedance or second impedance and change its resistance.
In the described light adjusting circuit of preferred embodiment of the present invention, when detecting voltage greater than this reference voltage, the resistance of variableimpedance unit is first impedance, drop to reference voltage so that detect voltage, and when detecting voltage less than reference voltage, the resistance of variableimpedance unit is second impedance, rises to reference voltage so that detect voltage.
From another viewpoint, the invention provides a kind of light-dimming method, it is suitable for controlling the brightness of luminescence unit in the backlight liquid crystal display module, and this light-dimming method comprises the following steps: at first, sets a reference current.Then, detect the load current of the luminescence unit of flowing through.Wherein, when load current during, increase the impedance in luminescence unit loop, so that load current drops to reference current greater than reference current; Otherwise,, reduce the impedance in luminescence unit loop, so that load current rises to reference current when load current during less than reference current.
From another viewpoint, the invention provides a kind of LCD again, it comprises display panels and backlight module.Wherein, backlight module is in order to providing display panels required light source, and this backlight module has a luminescence unit and a light adjusting circuit at least.In the described LCD of preferred embodiment of the present invention, luminescence unit is in order to producing light source, and light adjusting circuit is then in order to the brightness of control luminescence unit, and this light adjusting circuit comprises control module and variableimpedance unit.
In the described LCD of preferred embodiment of the present invention, control module is electrically connected first end of luminescence unit, in order to the detection electric current of luminescence unit of flowing through, and converts thereof into and detects voltage and compare with a reference voltage, with the output controlling signal.
In the described LCD of preferred embodiment of the present invention, control module comprises detecting unit and comparing unit.Wherein, detecting unit is electrically connected first end of luminescence unit, in order to the detection electric current of luminescence unit of flowing through, and converts thereof into and exports after detecting voltage.Comparing unit is electrically connected detecting unit, compares in order to a detection voltage and the reference voltage that detecting unit is exported, and the output controlling signal.
In the described LCD of preferred embodiment of the present invention, the variableimpedance unit is electrically connected second end of comparing unit and luminescence unit, and the controlling signal that this variableimpedance unit is exported according to comparing unit is first impedance or second impedance and change its resistance.
In the described LCD of preferred embodiment of the present invention, when detecting voltage greater than reference voltage, the resistance of variableimpedance unit is first impedance, drop to reference voltage so that detect voltage, and when detecting voltage less than reference voltage, the resistance of variableimpedance unit is second impedance, rises to reference voltage so that detect voltage.
Light adjusting circuit provided by the present invention and method thereof, can be applied to now in the backlight liquid crystal display module, it is by the impedance that changes the variableimpedance unit, and the impedance loop of luminescence unit in increase or the reduction backlight module, and the reference current size that before set for the deviser of the electric current that changes the luminescence unit of flowing through according to this, by this if change the resistance of detection resistance and the numerical value of reference voltage, can carry out the brightness adjustment at arbitrary luminescence unit in the backlight module, use to reach that elastic space is big, footprint area is little, and advantage such as cost of manufacture is cheap.In addition, just because of liquid crystal display applications of the present invention light adjusting circuit of the present invention in its backlight module, so not only can reach outside the above-listed described advantage, and can promote the picture quality that LCD was presented to reach so that the brightness that display panels presented is more even.
For above and other objects of the present invention, feature and advantage can be become apparent, preferred embodiment of the present invention cited below particularly, and be described with reference to the accompanying drawings as follows.
Description of drawings
Fig. 1 shows existing circuit diagram in order to the light adjusting circuit that reaches the multi-light tube current balance.
Fig. 2 shows the circuit diagram according to the light adjusting circuit of preferred embodiment of the present invention.
Fig. 3 shows utilization light adjusting circuit of the present invention to reach the circuit diagram of multi-light tube current balance.
Fig. 4 shows the process flow diagram according to the light-dimming method of preferred embodiment of the present invention.
The reference numeral explanation
100,200,200a～200n: light adjusting circuit
201: control module
201a: detecting unit
201b: comparing unit
203: the variableimpedance unit
L
1～L
n: fluorescent tube
T
1～T
8: high-tension transformer
C: first electric capacity
C
1～C
8: electric capacity
CT
1～CT
7: current transformer
D
1: first diode
D
2: second diode
R
D: detect resistance
OP: comparer
C
f: back coupling electric capacity
R
f: feedback resistance
SW: switch
R
1: first resistance
R
2: second resistance
S401～S405: each step of the light-dimming method process flow diagram that preferred embodiment of the present invention illustrated
Embodiment
Fig. 2 shows the circuit diagram according to the light adjusting circuit of preferred embodiment of the present invention.Please refer to Fig. 2, light adjusting circuit 200 for example can be in order to the interior luminescence unit L of backlight module (backlightmodule) of control LCD (not illustrating)
1(for example: fluorescent tube, cold-cathode tube, fluorescent light, Halogen lamp LED ... etc.) brightness, be not applied to technical field of the present invention but do not limit it at this.That is to say, need to adjust luminescence unit L as long as have
1Brightness the time, though it non-ly is applied to technical field of the present invention, it still belongs to protection scope of the present invention.
The detecting unit 201a of present embodiment is by the first diode D
1, the second diode D
2, and detect resistance R
DForm.Wherein, diode D
1Anode with detect resistance R
DSecond end in order to receive a reference potential (, but being not restricted to this current potential), diode D for example for earthing potential
1Negative electrode and luminescence unit first end and diode D
2Anode be electrically connected to each other and diode D
2Negative electrode then be electrically connected the detection resistance R
DFirst end.
In addition, comparing unit 201b is by comparer OP, back coupling capacitor C
f, and feedback resistance R
fForm.Wherein, the positive input terminal (+) of comparer OP is in order to receive reference voltage V
Ref, and the negative input end (-) of comparer OP is electrically connected the detection resistance R
DFirst end and feedback resistance R
fFirst end.Feedback resistance R
fSecond end be electrically connected to feedback capacitor C
fFirst end, and feedback capacitor C
fSecond end then be electrically connected the output terminal of comparer OP.
Please continue with reference to Fig. 2, variableimpedance unit 203 is electrically connected luminescence unit L
1With control module 201, in order to receive the driving signal V that is exported by anti-transverter (Inverter, not shown)
D, and will drive signal V by first capacitor C
DBe sent to luminescence unit L
1With control module 201, and the controlling signal CS that is exported according to control module 201, and decision increases or reduce luminescence unit L
1Impedance loop, be in reference voltage V with control detection voltage
RefWherein, first capacitor C drives signal V in order to filtering
DThe direct current composition.
In present embodiment, when detecting voltage greater than reference voltage V
RefThe time, the resistance of variableimpedance unit 203 is first impedance, and increases luminescence unit L
1Impedance loop drop to reference voltage V so that detect voltage
Ref, and adjust the luminescence unit L that flows through
1Current i
LRelatively, when detecting voltage less than reference voltage V
RefThe time, the resistance of variableimpedance unit 203 is second impedance, and reduces luminescence unit L
1Impedance loop rise to reference voltage V so that detect voltage
Ref, and adjust the luminescence unit L that flows through
1Current i
L
The variableimpedance unit 203 of present embodiment is by switch SW (for example can be MOS transistor or any assembly with switching function), first resistance R
1, second resistance R
2, and high-tension transformer T
1Form.Wherein, the control end of switch SW is electrically connected the output terminal of comparer OP, and first, second end of switch SW then distinctly is electrically connected first resistance R
1First and second end.Second resistance R
2First end be electrically connected second end of switch SW, and second resistance R
2Second end then be electrically connected high-tension transformer T
1First end of primary side.High-tension transformer T
1Second end of primary side be electrically connected first resistance R
1First end, and high-tension transformer T
1Primary side then in order to receive the driving signal V that anti-transverter is exported
D
And in order to be illustrated more clearly in the content of the foregoing description, below lift an example again: please continue with reference to Fig. 2, if will determine luminescence unit L
1The size of the brightness that is presented, the reference voltage V that can be received by the positive input terminal (+) of change comparer OP
RefValue with detect resistance R
DResistance, and the decision luminescence unit L that flows through
1Current i
L, also be about to reference voltage V
RefNumerical value divided by detecting resistance R
DResistance can learn.
Therefore, as high-tension transformer T
1Primary side receive the positive half cycle that anti-transverter exports and drive signal V
DAfter, because luminescence unit L
1Can equivalence regard a resistance r as
L, and this moment diode D
2Conducting is so can obtain the luminescence unit L that flows through with ohm theorem
1Current i
L, promptly positive half cycle drives signal V
DDivided by luminescence unit L
1Impedance loop, luminescence unit L wherein
1Impedance loop comprise: high-tension transformer T
1Primary side impedance, equivalent resistance r
L, diode D
2Conduction impedance r forward
D, and detect resistance R
DResistance.
Then, in order to make the luminescence unit L that flows through
1Current i
LFor before setting reference voltage V
RefValue with detect resistance R
DThe resistance value of trying to achieve.So according to above-mentioned current i of trying to achieve
LThe detection resistance R of flowing through
DAfter, can obtain detecting voltage, and this detects the negative input end (-) that voltage can be delivered to comparer OP, and the reference voltage V that is received with the positive input terminal (+) of comparer OP
RefCompare, and export the control end of a controlling signal CS to switch SW.
Wherein, when detecting voltage greater than reference voltage V
RefThe time, the controlling signal CS that comparer OP is exported causes switch SW to be ended, so high-tension transformer T
1Primary side impedance meeting promote and (to be first resistance R
1Resistance second resistance R that adds up
2Resistance), and well known because high-tension transformer T
1Has the equiva lent impedance characteristic, so according to high-tension transformer T
1Primary and secondary side number of turn relation, high-tension transformer T
1Primary side impedance lifting can cause high-tension transformer T
1The primary side impedance also promote, therefore just increased luminescence unit L
1Impedance loop, so can reduce the luminescence unit L that flows through
1Current i
LSo, detect voltage and also drop to reference voltage V
Ref
Otherwise, when detecting voltage less than reference voltage V
RefThe time, the controlling signal CS that comparer OP is exported causes the switch SW conducting, so high-tension transformer T
1Primary side impedance meeting descend and (to be first resistance R
1Resistance), so again according to high-tension transformer T
1Primary and secondary side number of turn relation, high-tension transformer T
1Primary side impedance decline can cause high-tension transformer T
1The primary side impedance also descend, therefore just reduced luminescence unit L
1Impedance loop, so can increase the luminescence unit L that flows through
1Current i
LSo, detect voltage and also rise to reference voltage V
RefIn the present embodiment, high-tension transformer T
1The primary side impedance change amplitude, can be by adjusting first resistance R
1With second resistance R
2Resistance, or high-tension transformer T
1The primary and secondary side number of turn.
Because comparer OP can relatively detect voltage and reference voltage V repeatedly
RefSo,, make that detecting voltage maintains reference voltage V by action so repeatedly
RefSo luminescence unit L flows through
1Current i
LMaintain and before set reference voltage V
RefValue with detect resistance R
DThe resistance value of trying to achieve.And what deserves to be mentioned is, in order to make comparer OP be in correct workspace (promptly allowing comparer OP running), in the present embodiment, on the negative feedback loop of comparer OP, add the back coupling capacitor C in action relatively
fWith feedback resistance R
f, to suppress comparer OP running in non-correct workspace (for example concussion).
In addition, the disclosed light adjusting circuit 200 of Fig. 2 is to drive signal V at the positive half cycle that anti-transverter is exported
DAction, but those skilled in the art is as can be known, as high-tension transformer T
1Primary side receive the negative half period that anti-transverter exports and drive signal V
DThe time, also can be according to spirit of the present invention, with the control luminescence unit L that flows through
1Current i
LMaintain and before set reference voltage V
RefNumerical value with detect resistance R
DThe resistance value of trying to achieve.
Fig. 3 shows utilization light adjusting circuit of the present invention to reach the circuit diagram of a plurality of luminescence unit current balance types.Please refer to Fig. 3, comprise a plurality of light adjusting circuit 200a～200n and a plurality of luminescence unit L in the circuit diagram by the disclosed a plurality of luminescence unit current balance types of Fig. 3
1～L
nWherein, the effect of light adjusting circuit 200a～200n is similar with the disclosed light adjusting circuit 200 of Fig. 2 with the relation of coupling, thus also no longer given unnecessary details at this, and in order to reach luminescence unit L
1～L
nCurrent balance type, only need reference voltage V
Ref1～V
RefnNumerical value with detect resistance R
D1～R
DnResistance all be made as unanimity, luminescence unit L
1～L
nThe brightness that is presented will be identical, to reach luminescence unit L
1～L
nCurrent balance type, so the brightness meeting that presented of display panels is more even, and the picture quality of its applied LCD also can promote thereupon.
As mentioned above, the disclosed a plurality of luminescence unit L of Fig. 3
1～L
nLuminescence unit L in the circuit diagram of current balance type
1～L
n, can in parallel (promptly be arranged parallel to each other and form) use, and be used in the backlight module of display panels.In addition, the user can be according to the actual design demand, and in good time change reference voltage V
Ref1～V
RefnNumerical value with detect resistance R
D1～R
DnResistance, realize the effect of other design.
In order to reach the effect that above-mentioned light adjusting circuit can provide, below enumerate a kind of light-dimming method again.Fig. 4 shows the process flow diagram according to the light-dimming method of preferred embodiment of the present invention.Please refer to Fig. 4, light-dimming method of the present invention be suitable for controlling a luminescence unit (for example: fluorescent tube, cold-cathode tube, fluorescent light, Halogen lamp LED ... etc.) brightness, and this light-dimming method comprises the following steps: at first, in step S401, sets a reference current.Wherein, this reference current is in order to the flow through electric current of luminescence unit of decision, also is the decision brightness that luminescence unit presented.
Then, in step S403, detect the load current of the luminescence unit of flowing through, and as described in the step S405,, increase the impedance in luminescence unit loop, so that load current drops to reference current when load current during greater than reference current; Otherwise, when load current during, reduce the impedance in luminescence unit loop less than reference current, so that load current rises to reference current, the control load current value is near reference current value, to present the brightness of the luminescence unit that is before determined by this.
In sum, the invention provides a kind of light adjusting circuit and method, it can be applicable to now in the backlight liquid crystal display module.And according to the above embodiments, the present invention comprises following advantage at least:
1. utilize the variableimpedance unit to replace the employed current transformer of prior art, to save footprint area, so can reduce cost of manufacture.
2. can adjust at single luminescence unit in the backlight liquid crystal display module, so use elastic space bigger.
3. by light adjusting circuit of the present invention is applied in the backlight liquid crystal display module, so can promote the picture quality that LCD was presented to reach so that the brightness that display panels presented is more even.
Though the present invention discloses as above with preferred embodiment; right its is not in order to limit the present invention; those skilled in the art can do a little change and retouching under the premise without departing from the spirit and scope of the present invention, so protection scope of the present invention is as the criterion with claim of the present invention.
Claims (15)
1. light adjusting circuit be suitable for controlling the brightness of a luminescence unit in the backlight module of a LCD, and this light adjusting circuit comprises:
One detecting unit is electrically connected first end of this luminescence unit, in order to the detection electric current of this luminescence unit of flowing through, and converts thereof into one and exports after detecting voltage;
One comparing unit is electrically connected this detecting unit, detects a voltage and a reference voltage in order to relatively to be somebody's turn to do, and exports a controlling signal; And
One variableimpedance unit is electrically connected second end of this comparing unit and this luminescence unit, and changing its resistance according to this controlling signal is one first impedance or one second impedance,
Wherein, when this detects voltage greater than this reference voltage, the resistance of this variableimpedance unit is this first impedance, so that this detection voltage drops to this reference voltage, and when this detects voltage less than this reference voltage, the resistance of this variableimpedance unit is this second impedance, so that this detection voltage rises to this reference voltage.
2. light adjusting circuit as claimed in claim 1, wherein this detecting unit comprises:
One first diode, its cathodic electricity connect first end of this luminescence unit, and the anode of this first diode is electrically connected first reference potential;
One second diode, its anode are electrically connected first end of this luminescence unit; And
One detects resistance, and its first end is electrically connected the negative electrode of this second diode, and second end of this detection resistance is electrically connected second reference potential.
3. light adjusting circuit as claimed in claim 1, wherein this comparing unit comprises a comparer, and its two input end is in order to receive this reference voltage and this detection voltage respectively, and the output terminal of this comparer is then exported this controlling signal.
4. light adjusting circuit as claimed in claim 3, wherein this comparing unit also comprises:
One feedback resistance, its first end be electrically connected this comparer two input ends one of them; And
One back coupling electric capacity, its first end is electrically connected second end of this feedback resistance, and second end of this back coupling electric capacity then is electrically connected the output terminal of this comparer.
5. light adjusting circuit as claimed in claim 1, wherein this variableimpedance unit comprises:
One switch, its control end is in order to receive this controlling signal;
One first resistance is with this switch in parallel;
One second resistance is connected with this switch;
Wherein, when this detected voltage greater than this reference voltage, this switch was a cut-off state, so that the resistance of this variableimpedance unit is this first impedance, and when this detected voltage less than this reference voltage, this switch was a conducting state, so that the resistance of this variableimpedance unit is this second impedance.
6. light adjusting circuit as claimed in claim 5, wherein this variableimpedance unit also comprises a high-tension transformer, and its primary side is electrically connected this first resistance and this second resistance, and the primary side of this high-tension transformer then receives the driving signal that anti-transverter is exported.
7. light adjusting circuit as claimed in claim 5, wherein this light adjusting circuit also comprises one first electric capacity, it is electrically connected on the primary side of this high-tension transformer and second end of this luminescence unit.
8. LCD comprises:
One display panels, and
One backlight module, it is in order to providing this display panels required light source, and this backlight module comprises at least:
One luminescence unit, it is in order to produce light source; And
One light adjusting circuit, it is in order to controlling the brightness of this luminescence unit, and this light adjusting circuit comprises:
One control module is electrically connected first end of this luminescence unit, in order to the detection electric current of this luminescence unit of flowing through, and converts thereof into one and detects voltage and compare with a reference voltage, to export a controlling signal; And
One variableimpedance unit is electrically connected second end of this control module and this luminescence unit, and changing its impedance according to this controlling signal is one first impedance or one second impedance,
Wherein, when this detects voltage greater than this reference voltage, the impedance of this variableimpedance unit is this first impedance, so that this detection voltage drops to this reference voltage, and when this detects voltage less than this reference voltage, the impedance of this variableimpedance unit is this second impedance, so that this detection voltage rises to this reference voltage.
9. LCD as claimed in claim 8, wherein this control module comprises:
One detecting unit is electrically connected first end of this luminescence unit, in order to the detection electric current of this luminescence unit of flowing through, and converts thereof into one and exports after detecting voltage; And
One comparing unit is electrically connected this detecting unit, detects a voltage and a reference voltage in order to relatively to be somebody's turn to do, and exports a controlling signal.
10. LCD as claimed in claim 9, wherein this detecting unit comprises:
One first diode, its cathodic electricity connect first end of this luminescence unit, and the anode of this first diode is electrically connected first reference potential;
One second diode, its anode are electrically connected first end of this luminescence unit; And
One detects resistance, and its first end is electrically connected the negative electrode of this second diode, and second end of this detection resistance is electrically connected second reference potential.
11. LCD as claimed in claim 9, wherein this comparing unit comprises a comparer, and in order to receive this reference voltage and this detection voltage, the output terminal of this comparer is then exported this controlling signal to its two input end respectively.
12. LCD as claimed in claim 11, wherein this comparing unit also comprises:
One feedback resistance, its first end be electrically connected this comparer two input ends one of them; And
One back coupling electric capacity, its first end is electrically connected second end of this feedback resistance, and second end of this back coupling electric capacity then couples the output terminal of this comparer.
13. LCD as claimed in claim 8, wherein this variableimpedance unit comprises:
One switch, its control end is in order to receive this controlling signal;
One first resistance is with this switch in parallel;
One second resistance is connected with this switch;
Wherein, when this detected voltage greater than this reference voltage, this switch was a cut-off state, so that the impedance of this variableimpedance unit is this first impedance, and when this detected voltage less than this reference voltage, this switch was a conducting state, so that the impedance of this variableimpedance unit is this second impedance.
14. LCD as claimed in claim 13, wherein this variableimpedance unit also comprises a high-tension transformer, its primary side is electrically connected this first resistance and this second resistance, and the primary side of this high-tension transformer then receives the driving signal that anti-transverter is exported.
15. LCD as claimed in claim 13, wherein this light adjusting circuit also comprises one first electric capacity, and it is electrically connected on the primary side of this high-tension transformer and second end of this luminescence unit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2007100079579A CN101236726B (en) | 2007-02-01 | 2007-02-01 | LCD device, light modulation circuit and its method |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2007100079579A CN101236726B (en) | 2007-02-01 | 2007-02-01 | LCD device, light modulation circuit and its method |
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| Publication Number | Publication Date |
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| CN101236726A true CN101236726A (en) | 2008-08-06 |
| CN101236726B CN101236726B (en) | 2011-12-07 |
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| CN2007100079579A Expired - Fee Related CN101236726B (en) | 2007-02-01 | 2007-02-01 | LCD device, light modulation circuit and its method |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN102446481A (en) * | 2010-10-09 | 2012-05-09 | 奇美电子股份有限公司 | Two-dimensional display, backlight module and drive method thereof |
| CN102917508A (en) * | 2012-10-31 | 2013-02-06 | 上海小糸车灯有限公司 | Multi-path constant current LED drive circuit with protection function and circuit board structure thereof |
| US8624525B2 (en) | 2009-10-19 | 2014-01-07 | Chimei Innolux Corporation | Flat display, backlight module and driving method thereof |
| WO2014082315A1 (en) * | 2012-11-28 | 2014-06-05 | 深圳市华星光电技术有限公司 | Backlight drive circuit and liquid crystal display |
| CN109243385A (en) * | 2018-11-12 | 2019-01-18 | 惠科股份有限公司 | Backlight adjusting circuit and display device |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1153119C (en) * | 2001-04-29 | 2004-06-09 | 广达电脑股份有限公司 | Double-regulating back lighting controller |
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2007
- 2007-02-01 CN CN2007100079579A patent/CN101236726B/en not_active Expired - Fee Related
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8624525B2 (en) | 2009-10-19 | 2014-01-07 | Chimei Innolux Corporation | Flat display, backlight module and driving method thereof |
| CN102446481A (en) * | 2010-10-09 | 2012-05-09 | 奇美电子股份有限公司 | Two-dimensional display, backlight module and drive method thereof |
| CN102917508A (en) * | 2012-10-31 | 2013-02-06 | 上海小糸车灯有限公司 | Multi-path constant current LED drive circuit with protection function and circuit board structure thereof |
| WO2014082315A1 (en) * | 2012-11-28 | 2014-06-05 | 深圳市华星光电技术有限公司 | Backlight drive circuit and liquid crystal display |
| CN109243385A (en) * | 2018-11-12 | 2019-01-18 | 惠科股份有限公司 | Backlight adjusting circuit and display device |
| US11450285B2 (en) | 2018-11-12 | 2022-09-20 | HKC Corporation Limited | Backlight adjustment circuit, backlight module and display device |
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|---|---|
| CN101236726B (en) | 2011-12-07 |
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