CN201429968Y - User device and backlight driving circuit thereof - Google Patents
User device and backlight driving circuit thereof Download PDFInfo
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- CN201429968Y CN201429968Y CN2009201638601U CN200920163860U CN201429968Y CN 201429968 Y CN201429968 Y CN 201429968Y CN 2009201638601 U CN2009201638601 U CN 2009201638601U CN 200920163860 U CN200920163860 U CN 200920163860U CN 201429968 Y CN201429968 Y CN 201429968Y
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- backlight
- positive
- triode
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Abstract
The utility model discloses a user device and a backlight driving circuit thereof. The backlight driving circuit disclosed by the utility model comprises a triode, a base electrode bias load and a negative feedback load, wherein a base electrode of the triode is connected to a universal input and output port for providing starting voltage after being connected with the base electrode bias load inseries, one of an emitting electrode and a collecting electrode of the diode is earthed after being connected with the negative feedback load in series, and the other of the emitting electrode and thecollecting electrode of the diode is connected with a power supply after being connected with a backlight source in series. The user device disclosed by the utility model comprises a backlight sourceproviding backlight for the user device, and a backlight drive circuit for driving the backlight source. The user device and the backlight driving circuit provided by the utility model can realize approximate constant current drive of the backlight source and can realize brightness consistency of the user device, and the backlight driving circuit has the advantages of low cost and small occupiedcircuit board area.
Description
Technical field
The utility model relates to a kind of subscriber equipment, relates in particular to a kind of backlight drive circuit that is used for subscriber equipment.
Background technology
The subscriber equipment of the overwhelming majority all can adopt white light-emitting diode (Light-EmittingDiode at present, abbreviation " LED ") is integrated in liquid crystal display (Liquid Crystal Display, be called for short " LCD ") the interior mode of module, thereby for the screen of subscriber equipment provides backlight, and the backlight drive circuit that is used for the driven for emitting lights diode generally all designs above the printed circuit board (PCB) at subscriber equipment (Printed Circuit Board is called for short " PCB ").
Backlight drive circuit of the prior art mainly adopts constant current source chip and low pressure difference linear voltage regulator (Low Dropout regulator is called for short " LDO ") these two kinds of schemes of chip, thereby provides backlight drive for the LCD of subscriber equipment.
Fig. 1 shows the synoptic diagram of the backlight drive circuit of available technology adopting constant current source chip.In this scheme, the constant current source chip is that the characteristics that the brightness according to LED is directly proportional with the electric current that flows through design and produce.This scheme is directly controlled output current by the voltage of control on the sample resistance, makes to flow through the electric current of LED and the forward voltage drop of LED (Vf) it doesn't matter, thereby can accurately control the brightness of LED.But adopt the scheme of constant current source chip generally to need more peripheral components, cost has also taken bigger PCB area when increasing, the miniaturization and the ultrathin design that are unfavorable for subscriber equipment, and existing constant current source chip is minimum to provide the two-way driving, for only using the LCD driving circuit of a backlight, low end user device caused waste, adopt scheme Electro Magnetic Compatibility (the Electro Magnetic Compatibility of constant current source chip in addition, abbreviation " EMC ") interference emission is more serious, influences the wireless performance of subscriber equipment.
Fig. 2 shows the synoptic diagram of the backlight drive circuit of available technology adopting LDO chip.In this scheme, the LDO chip has the low-dropout regulator of output voltage stabilization, and therefore when load was constant, the electric current that flows through load was also constant.But, since the forward voltage drop Vf of general LCD backlight LED generally at 3.0V between the 3.35V, and current-voltage correlation curve (VI curve) is non-linear fairly obvious, LDO is constant voltage output simultaneously, therefore the electric current that flows through different LED can differ bigger, thereby the luminance difference of feasible same batch subscriber equipment is very big.If realize the consistance of the brightness of different user devices, then require the consistance of LED forward voltage drop Vf fine, and this requirement can bring the rapid increase of cost, the driving circuit of this scheme also takies bigger PCB area simultaneously.
Therefore, backlight drive circuit of the prior art is under the situation of the brightness unanimity that keeps subscriber equipment, all have the cost height, take the bigger problem of PCB area, particularly for low end user device, the cost problem of backlight drive circuit of the prior art is particularly outstanding.
The utility model content
For this reason, the technical problems to be solved in the utility model provides subscriber equipment and backlight drive circuit thereof, can realizing the approximate constant-current driving of backlight, realize the consistance of the brightness of subscriber equipment, make simultaneously backlight drive circuit have cost low, take the little advantage of board area.
For solving the problems of the technologies described above, the utility model embodiment provides a kind of backlight drive circuit, described backlight drive circuit comprises NPN type triode, base bias load and degenerative load, the base stage of described NPN type triode be connected to the universal input and output port that trigger voltage is provided after described base bias load is connected, the emitter of the described NPN type triode back ground connection of connecting with described degenerative load, and the collector of described NPN type triode be connected to power supply after backlight is connected.
The utility model embodiment also provides a kind of backlight drive circuit, described backlight drive circuit comprises positive-negative-positive triode, base bias load and degenerative load, the base stage of described positive-negative-positive triode be connected to the universal input and output port that trigger voltage is provided after described base bias load is connected, the collector of the described positive-negative-positive triode back ground connection of connecting with described degenerative load, and the emitter of described positive-negative-positive triode be connected to power supply after backlight is connected.
The utility model embodiment also provides a kind of subscriber equipment, described subscriber equipment is included as described subscriber equipment backlight backlight is provided, and the backlight drive circuit that is used to drive described backlight, wherein, described backlight drive circuit comprises NPN type triode, base bias load and degenerative load, the base stage of described NPN type triode be connected to the universal input and output port that trigger voltage is provided after described base bias load is connected, the emitter of the described NPN type triode back ground connection of connecting with described degenerative load, and the collector of described NPN type triode be connected to power supply after backlight is connected.
The utility model embodiment also provides a kind of subscriber equipment, described subscriber equipment is included as described subscriber equipment backlight backlight is provided, and the backlight drive circuit that is used to drive described backlight, wherein, described backlight drive circuit comprises the positive-negative-positive triode, base bias load and degenerative load, the base stage of described positive-negative-positive triode be connected to the universal input and output port that trigger voltage is provided after described base bias load is connected, the collector of the described positive-negative-positive triode back ground connection of connecting with described degenerative load, and the emitter of described positive-negative-positive triode be connected to power supply after backlight is connected.
Based on technique scheme, because the backlight drive circuit among the utility model embodiment adopts the negative feedback working method, can realize the approximate constant-current driving of backlight, thereby it is very little to make that backlight brightness when the mains voltage variations of subscriber equipment changes, and can overcome because the inconsistent problem of brightness of the same batch of subscriber equipment that the difference of the forward voltage drop of backlight causes; On the other hand and since the utility model embodiment in backlight drive circuit adopted discrete component seldom, thereby have cost low, take the little advantage of board area, for ultra-thinization, the miniaturization Design of subscriber equipment are provided convenience.
Description of drawings
In order to be illustrated more clearly in the utility model embodiment or technical scheme of the prior art, to do to introduce simply to the accompanying drawing of required use in the utility model embodiment or the description of the Prior Art below, apparently, below described accompanying drawing only be some embodiment, for those of ordinary skills, under the prerequisite of not paying creative work, can also obtain other accompanying drawing according to these accompanying drawings.
Fig. 1 shows the synoptic diagram of the backlight drive circuit of available technology adopting constant current source chip;
Fig. 2 shows the synoptic diagram of the backlight drive circuit of available technology adopting LDO chip;
Fig. 3 shows the synoptic diagram of backlight drive circuit of the present utility model;
Fig. 4 shows the synoptic diagram of the output characteristics of NPN type triode;
Fig. 5 shows another synoptic diagram of backlight drive circuit of the present utility model; And
Fig. 6 shows the synoptic diagram of subscriber equipment of the present utility model.
Embodiment
Below in conjunction with the accompanying drawing among the utility model embodiment, the technical scheme among the utility model embodiment is clearly and completely described, obviously, described embodiment is a part of embodiment of the present utility model, rather than whole embodiment.Based on the embodiment in the utility model, those of ordinary skills are not making the every other embodiment that is obtained under the creative work prerequisite, all belong to the scope of the utility model protection.
The utility model embodiment provides a kind of backlight drive circuit, this backlight drive circuit comprises triode, base bias load and degenerative load, the base stage of this triode be connected to the universal input and output port that trigger voltage is provided after the base bias load is connected, in the emitter and collector of this triode one the back ground connection of connecting with degenerative load, and in the emitter and collector of this triode another be connected to power supply after backlight is connected.
In the utility model embodiment, triode can be the triode of NPN type, for example the germanium tube of the silicone tube of NPN type or NPN type, perhaps triode also can be the triode of positive-negative-positive, the germanium tube of the silicone tube of positive-negative-positive or positive-negative-positive for example, preferably, triode is the triode of NPN type.The utility model embodiment will be that example describes with NPN type triode mainly, but this does not should be understood to qualification of the present utility model.
When backlight drive circuit adopts NPN type triode, the base stage of NPN type triode be connected to the universal input and output port that trigger voltage is provided after the base bias load is connected, the emitter of the NPN type triode back ground connection of connecting with degenerative load, and the collector of NPN type triode be connected to power supply after backlight is connected; When backlight drive circuit adopts the positive-negative-positive triode, the base stage of positive-negative-positive triode be connected to the universal input and output port that trigger voltage is provided after the base bias load is connected, the collector of the positive-negative-positive triode back ground connection of connecting with degenerative load, and the emitter of positive-negative-positive triode be connected to power supply after backlight is connected.
As shown in Figure 3, backlight drive circuit comprises NPN type triode Q1, base bias load R1 and degenerative load R2.Wherein, triode Q1 electrifies and banishes big effect, and this triode Q1 has base stage B, collector C and emitter E; Base bias load R1 is used to be provided with the electric current that flows through base stage B, thereby guarantees can satisfy through the collector current after amplifying the requirement of backlight current; Thereby degenerative load R2 can be by regulating the effect that self voltage drop plays steady current.
The base stage B of this NPN type triode Q1 be connected to universal input and output port (the General Purpose I/O that trigger voltage is provided after base bias load R1 connects, be called for short " GPIO "), the emitter E of this NPN type triode Q1 back ground connection of connecting with degenerative load R2, and the collector C of this NPN type triode Q1 be connected to power supply BAT after backlight D1 connects.
The output characteristics of triode as shown in Figure 4, wherein transverse axis is represented collector emitter voltage U
CE, the longitudinal axis is represented collector current I
CBase-emitter voltage U when triode
BEGreater than cut-in voltage U
ON(U for NPN type silicone tube
ONBe approximately 0.7V) time, this moment, the duty of triode depended on collector emitter voltage U
CEWith the base-emitter voltage U
BEBetween relation.Work as U
CE＜U
BEThe time, triode works in state of saturation, at this moment collector current I
CWith collector emitter voltage U
CEVariation and alter a great deal; Work as U
CE〉=U
BEThe time, triode works in magnifying state, at this moment collector current I
CWith base current I
BThe pass is I
C=β I
B, and I
CNot with U
CEVariation and change, β is a constant, is commonly referred to current amplification factor.
The principle of work of the backlight drive circuit of the utility model embodiment will be described below.As shown in Figure 3, as supply voltage U
BATSatisfy U
BAT〉=U
LED+ U
BE+ R
b* I
CThe time, triode Q1 is operated in magnifying state, at this moment, and supply voltage U no matter
BATVariation still is the forward voltage drop U of backlight
LEDChange collector current I
CKeep substantially constant, wherein U
BEBe the base-emitter voltage of Q1, R
bResistance for degenerative load.The LCD that can guarantee subscriber equipment thus scintillation can not occur.
As supply voltage U
BATSatisfy U
BAT＜U
LED+ U
BE+ R
b* I
CThe time, triode Q1 is operated in state of saturation, as supply voltage U
BATWhen reducing, collector emitter voltage U
CEForward voltage drop U with backlight
LEDThe capital reduces thereupon, causes collector current I
CDiminish the brightness deepening of backlight; This moment is owing to the negative feedback of degenerative load R2, I
CReduce to make the voltage U of degenerative load R2
R2Reduce, thus U
CEAnd U
LEDThe voltage of getting becomes big (still can not return to the numerical value before supply voltage diminishes), thereby makes collector current I
CBecome big, the brightness of backlight is recovered significantly.Because the negative feedback effect of backlight drive circuit is carried out in real time, so collector current I
CChange very for a short time, the brightness of backlight changes also less.Thereby the backlight drive circuit that the utility model embodiment provides can be realized the approximate constant-current driving of backlight.
Based on technique scheme, because the backlight drive circuit among the utility model embodiment adopts the negative feedback working method, thereby can realize the approximate constant-current driving of backlight, thereby it is very little to make that backlight brightness when the supply voltage of subscriber equipment diminishes changes, and can overcome because the inconsistent problem of brightness of the same batch of subscriber equipment that the difference of the forward voltage drop of backlight causes; On the other hand and since the utility model embodiment in backlight drive circuit adopted discrete component seldom, thereby have cost low, take the little advantage of board area, for ultra-thinization, the miniaturization Design of subscriber equipment are provided convenience.
In the utility model embodiment, base bias load and degenerative load can be respectively a resistance, thereby low at the cost of realizing backlight drive circuit, take board area little in, the EMC interference problem of avoiding inductance or capacity cell to bring to the full extent, thereby the wireless performance of raising subscriber equipment.
In the utility model embodiment, for low end user device, backlight can be a light emitting diode, wherein, ground connection after the emitter of NPN type triode is connected with degenerative load, the collector of NPN type triode is connected with the negative pole of this light emitting diode, and the positive pole of this light emitting diode is connected with power supply.This scheme can be avoided the inconsistent problem of brightness of the different backlights of same subscriber equipment when reducing cost thus.
In the utility model embodiment, the resistance of base bias load and degenerative load can be determined by following formula:
Wherein, U
GPIOBe the voltage that universal input and output port provides, U
BATBe the voltage that power supply provides, U
BEBe the base-emitter voltage of triode, U
CEBe transistor collector-emitter voltage, U
LEDBe the forward voltage drop of backlight, R
aBe the resistance of base bias load, R
bBe the resistance of degenerative load, β is the current amplification factor of triode, I
CFor flowing through the electric current of light emitting diode.By rationally choosing of R1, R2 and Q1, can guarantee that the electric current that flows through backlight in the supply voltage working range of subscriber equipment changes less than 4mA, thereby make naked eyes can't differentiate the variation of back light source brightness.
In addition, choosing of each component parameters of the backlight drive circuit of the utility model embodiment it is also conceivable that following influence factors:
(1) design flow is crossed the current value I of light emitting diode
CThe time, if I
CThen the life-span of LED is exerted an influence greater than 25mA, if I
CDuring less than 15mA then naked eyes can feel the difference of LED brightness, therefore, flow through the electric current I of LED
CSpan can be 0.015A≤I
C≤ 0.025A preferably, can design flow crosses the electric current I of LED
CBe 20mA;
(2) selecting the principle of base bias load and degenerative load is to guarantee that as far as possible triode works in magnifying state because this moment collector current I
CSubstantially the influence that does not change, but be reduced to triode when entering state of saturation when supply voltage, I at this moment with supply voltage and LED forward voltage drop
CCan be along with U
CEVariation and change, so the selection of degenerative load R2 also needs to consider the Current Negative Three-Point Capacitance effect, the R2 resistance is big more, negative feedback effect is good more, but for identical external condition, the also easy more state of saturation that enters of triode.
The object lesson of the backlight drive circuit of the utility model embodiment is described below.For example, the voltage U that provides of universal input and output port
GPIOBe 1.8V, the minimum voltage U of power supply
BATBe 3.4V, the forward voltage drop U of backlight
LEDBe 3.0V, the currentamplificationfactor of triode is 180, flows through the electric current I of described light emitting diode
CBe made as 20mA, through type (1) can calculate the resistance R of base bias load
aShould get about 10K Ω the resistance R of degenerative load
bShould get less than 20 Ω.
The resistance of R1 and R2 can also further be optimized according to experimental result so that flow through the electric current of backlight be subjected to the forward voltage drop of supply voltage and backlight conforming influence less.Experiment finds to work as R
aGet 10K Ω and R
bWhen getting 1 Ω, when supply voltage when 3.4V changes to 4.2V, the electric current that flows through backlight LED changes and has only 2.9mA, as shown in Table 1, visually can't distinguish this variation; In addition for the forward voltage drop of LED when changing between the 3.0V to 3.3V, the luminance difference of different user devices is very little, visually also can't distinguish this variation.
Table one
| U BAT(V) | I C(mA) |
| 3.4 | 18.0 |
| 3.5 | 19.7 |
| 3.55 | 20.1 |
| 3.6 | 20.3 |
| 3.7 | 20.4 |
| 3.8 | 20.6 |
| 4.0 | 20.8 |
| 4.2 | 20.9 |
As shown in Figure 5, when the triode that comprises when backlight drive circuit is positive-negative-positive triode Q2, the base stage B of this positive-negative-positive triode Q2 be connected to the universal input and output port that trigger voltage is provided after base bias load R1 ' connects, the collector C of this positive-negative-positive triode Q2 back ground connection of connecting with degenerative load R2 ', and the emitter E of this positive-negative-positive triode Q2 be connected to power supply BAT after backlight D1 connects.
In the utility model embodiment, for low end user device, backlight can be a light emitting diode, wherein, ground connection after the collector of positive-negative-positive triode is connected with degenerative load, the emitter of positive-negative-positive triode is connected with the negative pole of this light emitting diode, and the positive pole of this light emitting diode is connected with power supply.This scheme can be avoided the inconsistent problem of brightness of the different backlights of same subscriber equipment when reducing cost thus.
In the utility model embodiment, base bias load and degenerative load can be respectively a resistance, thereby low at the cost of realizing backlight drive circuit, take board area little in, the EMC interference problem of avoiding inductance or capacity cell to bring to the full extent, thereby the wireless performance of raising subscriber equipment.Similarly, in embodiments of the present invention, flow through the current value I of light emitting diode
CSpan can be 0.015A≤I
C≤ 0.025A preferably, can design flow crosses the electric current I of LED
CBe 20mA.
Wherein, the design of the principle of work of the backlight drive circuit that present embodiment is related, base bias load, degenerative load and backlight with choose etc., the related content that can disclose with reference to above-mentioned Fig. 3 and the related embodiment of Fig. 4 does not repeat them here.
The utility model embodiment also provides a kind of subscriber equipment 200, and as shown in Figure 6, this subscriber equipment 200 is included as subscriber equipment 200 backlight 210 backlight is provided, and the backlight drive circuit 220 that is used to drive this backlight 210.Wherein, this subscriber equipment 200 includes but not limited to mobile phone, portable computer, personal digital assistant, portable game machine and portable multimedia machine; This backlight drive circuit 220 comprises triode, base bias load and degenerative load, when backlight drive circuit adopts NPN type triode, the base stage of NPN type triode be connected to the universal input and output port that trigger voltage is provided after the base bias load is connected, the emitter of the NPN type triode back ground connection of connecting with degenerative load, and the collector of NPN type triode be connected to power supply after backlight is connected; When backlight drive circuit adopts the positive-negative-positive triode, the base stage of positive-negative-positive triode be connected to the universal input and output port that trigger voltage is provided after the base bias load is connected, the collector of the positive-negative-positive triode back ground connection of connecting with degenerative load, and the emitter of positive-negative-positive triode be connected to power supply after backlight is connected.
Based on technique scheme, because the backlight drive circuit of the subscriber equipment of the utility model embodiment adopts the negative feedback working method, thereby can realize the approximate constant-current driving of backlight, thereby it is very little to make that backlight brightness when the supply voltage of subscriber equipment diminishes changes, and can overcome because the inconsistent problem of brightness of the same batch of subscriber equipment that the difference of the forward voltage drop of backlight causes; On the other hand and since the utility model embodiment in backlight drive circuit adopted discrete component seldom, thereby have cost low, take the little advantage of board area, for ultra-thinization, the miniaturization Design of subscriber equipment are provided convenience.
In the utility model embodiment, backlight can be a light emitting diode; Base bias load and degenerative load can be respectively a resistance; Triode can be NPN type triode, also can be the positive-negative-positive triode.Wherein, the related backlight drive circuit of the utility model embodiment can not repeat them here with reference to the related content of the related embodiment exposure of above-mentioned Fig. 3 to Fig. 5.
Although the utility model by with reference to the accompanying drawings and mode in conjunction with the preferred embodiments describe in detail, the utility model is not limited to this.Under the prerequisite that does not break away from spirit of the present utility model and essence, those of ordinary skill in the art can carry out the distortion and the change of various equivalences to embodiment of the present utility model, and these distortion and change are all in covering scope of the present utility model.
Claims (12)
1. backlight drive circuit, it is characterized in that, comprise NPN type triode, base bias load and degenerative load, the base stage of described NPN type triode be connected to the universal input and output port that trigger voltage is provided after described base bias load is connected, the emitter of the described NPN type triode back ground connection of connecting with described degenerative load, and the collector of described NPN type triode be connected to power supply after backlight is connected.
2. backlight drive circuit according to claim 1, it is characterized in that, described backlight is a light emitting diode, being connected to power supply after the series connection of the collector of described NPN type triode and backlight comprises: the collector of described NPN type triode is connected with the negative pole of described light emitting diode, and the positive pole of described light emitting diode is connected with described power supply.
3. backlight drive circuit according to claim 1 is characterized in that, described base bias load and described degenerative load are respectively a resistance.
4. backlight drive circuit according to claim 2 is characterized in that, flows through the electric current I of described light emitting diode
CSpan be: 0.015A≤I
C≤ 0.025A.
5. backlight drive circuit, it is characterized in that, comprise positive-negative-positive triode, base bias load and degenerative load, the base stage of described positive-negative-positive triode be connected to the universal input and output port that trigger voltage is provided after described base bias load is connected, the collector of the described positive-negative-positive triode back ground connection of connecting with described degenerative load, and the emitter of described positive-negative-positive triode be connected to power supply after backlight is connected.
6. backlight drive circuit according to claim 5, it is characterized in that, described backlight is a light emitting diode, being connected to power supply after the series connection of the emitter of described positive-negative-positive triode and backlight comprises: the emitter of described positive-negative-positive triode is connected with the negative pole of described light emitting diode, and the positive pole of described light emitting diode is connected with described power supply.
7. backlight drive circuit according to claim 5 is characterized in that, described base bias load and described degenerative load are respectively a resistance.
8. backlight drive circuit according to claim 6 is characterized in that, flows through the electric current I of described light emitting diode
CSpan be: 0.015A≤I
C≤ 0.025A.
9. a subscriber equipment is characterized in that, be included as described subscriber equipment backlight backlight is provided, and the backlight drive circuit that is used to drive described backlight,
Wherein, described backlight drive circuit comprises NPN type triode, base bias load and degenerative load, the base stage of described NPN type triode be connected to the universal input and output port that trigger voltage is provided after described base bias load is connected, the emitter of the described NPN type triode back ground connection of connecting with described degenerative load, and the collector of described NPN type triode be connected to power supply after backlight is connected.
10. subscriber equipment according to claim 9, it is characterized in that, described backlight is a light emitting diode, being connected to power supply after the series connection of the collector of described NPN type triode and backlight comprises: the collector of described NPN type triode is connected with the negative pole of described light emitting diode, and the positive pole of described light emitting diode is connected with described power supply.
11. a subscriber equipment is characterized in that, is included as described subscriber equipment backlight backlight is provided, and the backlight drive circuit that is used to drive described backlight,
Wherein, described backlight drive circuit comprises positive-negative-positive triode, base bias load and degenerative load, the base stage of described positive-negative-positive triode be connected to the universal input and output port that trigger voltage is provided after described base bias load is connected, the collector of the described positive-negative-positive triode back ground connection of connecting with described degenerative load, and the emitter of described positive-negative-positive triode be connected to power supply after backlight is connected.
12. subscriber equipment according to claim 11, it is characterized in that, described backlight is a light emitting diode, being connected to power supply after the series connection of the collector of described positive-negative-positive triode and backlight comprises: the emitter of described positive-negative-positive triode is connected with the negative pole of described light emitting diode, and the positive pole of described light emitting diode is connected with described power supply.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009201638601U CN201429968Y (en) | 2009-07-03 | 2009-07-03 | User device and backlight driving circuit thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009201638601U CN201429968Y (en) | 2009-07-03 | 2009-07-03 | User device and backlight driving circuit thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201429968Y true CN201429968Y (en) | 2010-03-24 |
Family
ID=42033708
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|---|---|---|---|
| CN2009201638601U Expired - Lifetime CN201429968Y (en) | 2009-07-03 | 2009-07-03 | User device and backlight driving circuit thereof |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105957475A (en) * | 2015-12-27 | 2016-09-21 | 天津市品通电力科技有限公司 | Display screen control circuit of electric power instrument |
| CN108650404A (en) * | 2018-04-08 | 2018-10-12 | 努比亚技术有限公司 | Port start-up circuit, device and mobile terminal |
| CN110211540A (en) * | 2019-05-30 | 2019-09-06 | 深圳创维－Rgb电子有限公司 | A kind of multi-region method for controlling backlight thereof, device, terminal and storage medium |
-
2009
- 2009-07-03 CN CN2009201638601U patent/CN201429968Y/en not_active Expired - Lifetime
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105957475A (en) * | 2015-12-27 | 2016-09-21 | 天津市品通电力科技有限公司 | Display screen control circuit of electric power instrument |
| CN108650404A (en) * | 2018-04-08 | 2018-10-12 | 努比亚技术有限公司 | Port start-up circuit, device and mobile terminal |
| CN108650404B (en) * | 2018-04-08 | 2021-01-22 | 努比亚技术有限公司 | Port starting circuit, device and mobile terminal |
| CN110211540A (en) * | 2019-05-30 | 2019-09-06 | 深圳创维－Rgb电子有限公司 | A kind of multi-region method for controlling backlight thereof, device, terminal and storage medium |
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