CN207925111U - Backlight source drive circuit and liquid crystal display - Google Patents
Backlight source drive circuit and liquid crystal display Download PDFInfo
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- CN207925111U CN207925111U CN201820412552.7U CN201820412552U CN207925111U CN 207925111 U CN207925111 U CN 207925111U CN 201820412552 U CN201820412552 U CN 201820412552U CN 207925111 U CN207925111 U CN 207925111U
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Abstract
The utility model discloses a backlight drive circuit and LCD. The circuit comprises a main control module and also comprises: the dimming control module is used for sending an on-off control signal to the PWM dimming module according to the PWM dimming signal sent by the main control module when receiving the backlight source conducting signal; sending a driving input signal to the isolation driving module according to the current signal fed back by the PWM dimming module; the isolation driving module is used for processing the driving input signal and outputting a driving output signal for controlling the flyback transformer module to work; the flyback transformer module is used for converting the alternating-current voltage into the direct-current voltage required by the PWM dimming module according to the driving output signal; and the PWM dimming module is used for outputting output current with adjustable duty ratio to the backlight source according to the on-off control signal and the direct current voltage so as to realize dimming of the backlight source. By adopting the above technical scheme, the utility model, backlight drive circuit can be simplified and the reliability of adjusting luminance is improved.
Description
Technical field
The utility model is related to technical field of liquid crystal display more particularly to backlight source driving circuits and liquid crystal display.
Background technology
Currently, pulse width modulation (Pulse Width Modulation, PWM) light modulation is widely used to liquid crystal display
The adjusting of back light source brightness in device, and PWM light modulations can pass through backlight drive that the backlight with liquid crystal display is connected electricity
It realizes on road.Fig. 1 gives a kind of existing backlight source driving circuit for realizing PWM light modulations, as shown in Figure 1, the backlight drive is electric
Road is integrally realized by the way of flyback topologies and boosting (BOOST) topological structure, is specifically included：Flyback transformer 11, flyback
Control module 12, boost chopper (BOOST circuits) 13, PWM light adjusting circuits 14 and dimming controlling module 15, work are former
Reason is：The drive signal control flyback transformer 11 that flyback control module 12 exports works, to input AC power AC
Alternating voltage converts low-voltage DC；The current signal output driving that dimming controlling module 15 is fed back according to PWM light adjusting circuits 14
Signal drives the BOOST circuits low-voltage DC that flyback transformer 11 exports is boosted to the voltage needed for backlight, and leads to
It crosses PWM light adjusting circuits 14 to dim backlight PWM, to realize the brightness regulation of backlight of LCD.
But inventor has found the prior art in the process of implementing the utility model that there are following technological deficiencies：It is existing
The circuit structure of backlight source driving circuit is complex, and backlight source driving circuit is caused to need the printed wiring board occupied
The area of (Printed Circuit Board, PCB) is larger, and required cost is higher, in addition, existing backlight source driving circuit is adopted
Secondary topological structure also affects the reliability of PWM light modulations.
Utility model content
In view of this, the utility model embodiment provides backlight source driving circuit and liquid crystal display, to solve existing skill
The technology that the circuit structure of backlight source driving circuit is complex in art, occupied pcb board area is larger and light modulation reliability is low
Problem.
In a first aspect, the utility model embodiment provides a kind of backlight source driving circuit, including：Main control module, also
Including：Dimming controlling module, isolation drive module, flyback voltage changing module and pulse width modulation (PWM) light-adjusting module, wherein
The dimming controlling module is connected with the main control module, also respectively with the PWM light-adjusting modules and drive is isolated
Dynamic model block is connected, for when receiving backlight Continuity signal, according to the PWM dim signals that the main control module is sent,
Break-make, which is sent, to the PWM light-adjusting modules controls signal；And according to the current signal of PWM light-adjusting modules feedback to institute
It states isolation drive module and sends drive input signal；
The isolation drive module is connected with the flyback voltage changing module, is carried out for the drive input signal to reception
Drive signal processing, output control the drive output signal of the flyback voltage changing module work；
The flyback voltage changing module is connected with AC power and the PWM light-adjusting modules respectively, for according to reception
The alternating voltage of AC power is converted to the DC voltage needed for the PWM light-adjusting modules and is supplied to institute by drive output signal
State PWM light-adjusting modules；
The PWM light-adjusting modules, are connected with backlight, for controlling signal and flyback change pressing mold according to the break-make
The DC voltage that block provides, to the adjustable output current of backlight output duty cycle, to realize the tune to the backlight
Light.
Second aspect, the utility model embodiment additionally provide a kind of liquid crystal display, including backlight, further include this reality
With the backlight source driving circuit described in new embodiment.
In the technical solution of above-mentioned backlight driver, dimming controlling module is connecing when receiving backlight shutdown signal
When receiving backlight Continuity signal, according to the PWM dim signals that main control module is sent, break-make control is sent to PWM light-adjusting modules
Signal processed；And drive input signal is sent to isolation drive module according to the current signal of PWM light-adjusting modules feedback；Isolation is driven
To the drive input signal of reception into horizontal-drive signal processing, the driving of output control flyback voltage changing module work exports dynamic model block
Signal；The alternating voltage of AC power is converted to PWM light-adjusting modules by flyback voltage changing module according to the drive output signal of reception
Required DC voltage is simultaneously supplied to PWM light-adjusting modules；PWM light-adjusting modules control signal according to break-make and flyback voltage changing module carries
The DC voltage of confession, the adjustable output current of the light source output that supports or opposes duty ratio, to realize the light modulation to backlight.Above-mentioned backlight
The technical solution of driving can control flyback transformation when receiving backlight Continuity signal using a dimming controlling module
Circuit and PWM light adjusting circuits realize the required constant voltage that flyback transforming circuit directly exports PWM light modulations, thereby simplify
The topological structure and controlling unit of backlight source driving circuit, reduce backlight source driving circuit occupied by pcb board area, save at
This, while also improving the reliability of backlight source driving circuit.
Description of the drawings
By reading a detailed description of non-restrictive embodiments in the light of the attached drawings below, the utility model
Other features, objects and advantages will become more apparent upon：
Fig. 1 gives a kind of existing backlight source driving circuit for realizing PWM light modulations；
Fig. 2 is a kind of structural schematic diagram for backlight source driving circuit that the utility model embodiment provides；
Fig. 3 is a kind of electrical block diagram for isolation drive module that the utility model embodiment provides.
Specific implementation mode
The utility model is described in further detail with reference to the accompanying drawings and examples.It is understood that herein
Described specific embodiment is used only for explaining the utility model, rather than the restriction to the utility model.It further needs exist for
It is bright, it illustrates only for ease of description, in attached drawing and the relevant part of the utility model rather than full content.
The utility model embodiment provides a kind of backlight source driving circuit.The backlight source driving circuit, which can be used for driving, to be realized
The Dimming operation of backlight.Fig. 2 is a kind of structural schematic diagram for backlight source driving circuit that the utility model embodiment provides.Such as
Shown in Fig. 2, which includes：Main control module 50 further includes：Dimming controlling module 10, isolation drive module
20, flyback voltage changing module 30 and PWM light-adjusting modules 40, wherein
Dimming controlling module 10 is connected with main control module 50, also respectively with PWM light-adjusting modules 40 and isolation drive module
20 are connected, for when receiving backlight Continuity signal, according to the PWM dim signals that main control module 50 is sent, to PWM
Light-adjusting module 40 sends break-make and controls signal, and the current signal fed back according to PWM light-adjusting modules 40 to isolation drive module
20 send drive input signal；
Isolation drive module 20 is connected with flyback voltage changing module 30, is driven for the drive input signal to reception
Signal processing, the drive output signal of 30 work of output control flyback voltage changing module；
Flyback voltage changing module 30 is connected with AC power 60 and PWM light-adjusting modules 40 respectively, for the drive according to reception
The alternating voltage of AC power 60 is converted to the DC voltage needed for PWM light-adjusting modules 40 and is supplied to PWM by dynamic output signal
Light-adjusting module 40；
PWM light-adjusting modules 40 are connected with backlight 70, for controlling signal and flyback voltage changing module 30 according to the break-make
The DC voltage of offer, to the adjustable output current of 70 output duty cycle of backlight, to realize the light modulation to backlight 70.
In the above scheme, backlight 70 can be the luminescent devices such as light emitting diode or organic electroluminescent piece.Driving
Input signal and drive output signal can be voltage signal or current signal etc., it is contemplated that in drive signal recipient's detection
Convenience when drive signal is stated, above-mentioned drive input signal and drive output signal are preferably voltage signal.
Backlight Continuity signal can be generated by external control device or main control module 50, typically can be by outside
The main control module 50 of the on or off for controlling backlight 70 of configuration generates.In the present embodiment, the main control module
50 can work as main control with 10 direct or indirect connection of dimming controlling module in backlight source driving circuit provided in this embodiment
When module 50 receives the backlight turn-on command of user's triggering, or receive electronic equipment belonging to backlight 70 (typically
The television set or computer of liquid crystal display are such as installed) central processing unit send backlight turn-on command and/or inspection
When measuring conditions present and meeting the turn-on condition of backlight 70, it can be sent to the dimming controlling module 10 in the technical program
Backlight Continuity signal.
In the present embodiment, dimming controlling module 10 is equivalent to when receiving backlight Continuity signal on backlight 70
There are electric currents, since backlight 70 is connected with PWM light-adjusting modules 40, it is believed that and PWM light-adjusting modules 40 are in and are powered on pattern,
And luminous required electric current is provided to backlight 70, meanwhile, dimming controlling module 10 also can receive the hair of main control module 50
The PWM dim signals (frequency of the PWM dim signals is usually 200HZ) sent, then generation one is same with the PWM dim signals
The synchronous break-make of frequency controls signal, and break-make control signal is supplied to PWM light-adjusting modules 40, to control PWM light-adjusting modules
40 upper switch pipe break-makes；In addition, PWM light-adjusting modules 40 can also carry out current signal feedback, light modulation to dimming controlling module 10
The current signal of feedback can be compared by control module 10 with preset current reference value, generate drive input signal (one
As, the frequency of the drive input signal is tens even hundreds of KHZ) and export to isolation drive module 20；Isolation drive
Module 20 can be used for drive input signal into horizontal-drive signal processing, to export the drive of 30 work of control flyback voltage changing module
Dynamic output signal.
The present embodiment purpose is to realize single dimming controlling module 10 simultaneously to flyback voltage changing module 30 and PWM tune
The control of optical module 40, but in practical applications, the current signal needed for control flyback voltage changing module 30 is apparently higher than control
Current signal needed for PWM light-adjusting modules 40, the drive input signal that dimming controlling module 10 is formed as a result, can not directly be made
For flyback voltage changing module 30, but need to set isolated drive circuit to drive input signal progress signal processing；It drives defeated
The working condition of flyback voltage changing module 30 can be controlled by going out signal, at the same can to the output voltage of flyback voltage changing module 30 into
Row regulation and control, i.e., flyback voltage changing module 30 in the operational mode can be by the alternating current of AC power 60 according to the drive output signal
Pressure is converted to the DC voltage needed for PWM light-adjusting modules 40；PWM light-adjusting modules 40 can be provided according to regulation and control control module 10
Break-make control signal and flyback voltage changing module 30 provide DC voltage, to the adjustable output of 70 output duty cycle of backlight
Electric current is achieved in the light modulation of backlight 70.
It should be noted that also there is the dimming controlling module 10 in the present embodiment control PWM light-adjusting modules 40 to carry out perseverance
Flow the effect of output.For example, when it is setting value that PWM light-adjusting modules 40, which need the target current exported, regulation and control control mould
Block 10 can analyze the current value of 40 fed-back current signals of PWM light-adjusting modules, and the current value of Cutoff current signal is
It is no to be equal to required setting value, if it is less than setting value, then it can generate the corresponding first driving input letter of the predicting relation
Number, as a result, according to first drive input signal by isolation drive module 20 can control flyback voltage changing module 30 output compared with
High DC voltage is supplied to PWM light-adjusting modules 40, meanwhile, dimming controlling module 10 can also be dimmed according to externally input PWM
Signal inputs break-make to PWM light-adjusting modules 40 and controls signal, and signal is controlled to the switch on PWM light-adjusting modules 40 based on break-make
Pipe carries out break-make control, comes the corresponding duration for increasing high level in the pulse period, current to increase PWM light-adjusting modules 40
The current value of output ensures that current value meets setting value；If the current value of current signal is greater than the set value, this can be generated
Corresponding second drive input signal of predicting relation, passes through isolation drive module 20 by second drive input signal as a result,
It flyback voltage changing module 30 can be controlled exports relatively current lower DC voltage and be supplied to PWM light-adjusting modules 40, meanwhile, in root
Break-make being inputted to PWM light-adjusting modules 40 according to externally input PWM dim signals and controlling signal, signal is controlled to PWM based on break-make
Switching tube on light-adjusting module 40 carries out break-make control, carrys out the corresponding duration for reducing high level in the pulse period, to drop
The current value that low PWM light-adjusting modules 40 currently export ensures that the current value meets setting value.It, can be with so by repeatedly adjusting
Ensure the constant current output of PWM light-adjusting modules 40.
In backlight source driving circuit provided in this embodiment, dimming controlling module 10 is additionally operable to receiving backlight pass
When break signal, stop inputting the break-make control signal to PWM light-adjusting modules 40, and stop inputting to isolation drive module 20
The drive input signal is stopped with controlling PWM light-adjusting modules 40 and isolation drive module 20.
Specifically, dimming controlling module 10 is equivalent on backlight 70 and stopped when receiving backlight cut-off signals
The supply of electric current, at this time it is believed that dimming controlling module 10 will stop generating the break-make for being supplied to PWM light-adjusting modules 40 and controlling believing
Number, at this point, dimming controlling module 10 does not receive the current signal of the feedback of PWM light-adjusting modules 40, thus dimming controlling module yet
10 also accordingly stopped the formation of drive input signal, to also provide drive input signal without normal direction isolation drive module 20,
And then control PWM light-adjusting modules 40 and isolation drive module 20 are stopped, and thus avoid certain in backlight source driving circuit
A little modules work on (typically such as flyback voltage changing module 30) to the damage caused by electronic equipment belonging to backlight 70.
The specific connection relation of each module of backlight source driving circuit provided in this embodiment can be arranged as required to, optional
, as shown in Fig. 2, the output end of AC power 60 is connected with the first input end of flyback voltage changing module 30, flyback voltage changing module
30 the first output end is connected with the first input end of PWM light-adjusting modules 40, the first output end and backlight of PWM light-adjusting modules 40
The input terminal in source 70 is connected；The output end of backlight 70 is connected with the second input terminal of PWM light-adjusting modules 40, PWM light-adjusting modules
40 second output terminal is connected with the second input terminal of flyback voltage changing module 30, the second output terminal of flyback voltage changing module 30 and friendship
The input terminal in galvanic electricity source 60 is connected；The third output end of first input end and PWM light-adjusting modules 40 in dimming controlling module 10
It is connected, the second input terminal of dimming controlling module 10 is connected with the input terminal of main control module 50；The of dimming controlling module 10
One output end is connected with the third input terminal of PWM light-adjusting modules 40；The second output terminal and isolation drive of dimming controlling module 10
The input terminal of module 20 is connected；The output end of isolation drive module 20 is connected with the switching tube of flyback voltage changing module 30.
Further, dimming controlling module is preferably a brightness adjustment control chip by this implementation, the brightness adjustment control chip packet
It includes：Feedback pin, PWM pins and GATE pins；The feedback pin is connected with the third output end of PWM light-adjusting modules 40, uses
In the current signal for receiving the feedback of PWM light-adjusting modules 40；The PWM pins are connected with 50 output end of main control module；While with
The third input terminal of PWM light-adjusting modules 40 is connected, and the PWM dim signals for being sent according to main control module 50 are generated and sent
Break-make to PWM light-adjusting modules 40 controls signal；The GATE pins, are connected with the input terminal of isolation drive module 20, are used for
The current signal received according to the feedback pin generates the drive input signal inputted to isolation drive module 20.
It is understood that further including in addition to comprising each pin set forth above in the brightness adjustment control chip of the present embodiment
Have other pins of other functions, such as grounding pin, overvoltage protection pin and chip select pin.
In addition, brightness adjustment control chip can be preferably integrated Metal-oxide-semicondutor (Metal- by the present embodiment
Oxide-semiconductor, MOS) pipe MP3398 control chip；Alternatively, being preferably external metal-oxide-semiconductor by brightness adjustment control chip
OB3350E chips.It is understood that the brightness adjustment control chip of the present embodiment, which can also be other, carries PWM dimming functions
Control chip.
Fig. 3 is a kind of electrical block diagram for isolation drive module that the utility model embodiment provides.Such as Fig. 3 institutes
Show, isolation drive module includes：Totem driving circuit 201 and driving isolation circuit 202；Totem driving circuit 201 it is defeated
Enter end with GATE pins to be connected, the drive input signal for exporting GATE pins generates driving into horizontal-drive signal processing
Analog signal that treated；The input terminal of driving isolation circuit 202 is connected with the output end of totem driving circuit 201, is used for
The analog signal isolating generated by totem driving circuit 201 is transformed into digital signal, the digital signal is for controlling
The drive output signal of flyback voltage changing module work processed.
Specifically, as shown in figure 3, totem driving circuit 201, including：First resistor R1, second resistance R2, the one or three
Pole pipe Q1, the second triode Q2,3rd resistor R3 and the first diode D1；The base of first triode Q1 and the second triode Q2
Pole is connected by first resistor R1 with the GATE pins of brightness adjustment control chip U1 respectively, meanwhile, the first triode Q1 and the two or three
The base stage of pole pipe Q2 is grounded by second resistance R2；The collector of first triode Q1 is connected with direct-flow external power source VCC, and first
The emitter of triode Q1 is connected with the emitter of the second triode Q2, the grounded collector of the second triode Q2；3rd resistor
R3 is connected with the input terminal after the first diode D1 parallel connections with the emitter of the first triode Q1,3rd resistor R3 and the one or two pole
Output end after pipe D1 parallel connections is connected with the input terminal of driving isolation circuit 202.Isolation circuit 202 is driven, including：Pulse transforming
Device T1, the second diode D2, third diode D3 and the 4th resistance R4；The first input end and totem of pulse transformer T1
The output end of column driving circuit 201 is connected, the second input end grounding of pulse transformer T1；The first output of pulse transformer T1
End is connected with the first end of the second diode D2, the first end of the second output terminal and third diode D3 of pulse transformer T1
It is grounded after being connected；The second end of second diode D2 and the second end of third diode are become by the 4th resistance R4 and flyback respectively
The switching tube G of die block is connected.
In the present embodiment, the circuit structure diagram based on the isolation drive module provided in Fig. 3, in brightness adjustment control chip U1
When receiving backlight Continuity signal, the current signal that can be received according to feedback pin generates regulation and control PWM light-adjusting modules
PWM Regulate signals, it is to be understood that the PWM Regulate signals are equivalent to an impulse wave, and brightness adjustment control chip draws according to PWM
The PWM Regulate signals generated at foot, can also generate the drive input signal synchronous with PWM Regulate signals at GATE pins,
The drive input signal corresponds again to an impulse wave.Brightness adjustment control chip U1 passes through isolation drive according to drive input signal
When module forms the drive output signal for controlling flyback voltage changing module, two-part processing is mainly have passed through, that is, is first passed through
Totem driving circuit 201 carries out signal processing to drive input signal, and drive signal is exported to an isolation by treated
The pulse transformer T1 of effect, so that treated, drive signal can be connect by the switching tube that analog-signal transitions are flyback transformer
The digital signal of receipts.
Illustratively, totem driving circuit 201 is equivalent to an amplifying circuit, when the driving that GATE pins currently input
When input signal is in high level, increased marked as the voltage value at A, at this point, the first triode Q1 is in the conduction state, second
Triode Q2 is off state, thereby guarantees that the voltage value at marked as B increases, and be equivalent to realizes driving input letter at this time
Number signal processing, at B voltage value increase when, by drive isolation circuit 202 isolation processing after, the ends switching tube G just
The drive output signal of high level can accordingly be exported；Conversely, when the drive input signal that GATE pins currently input is in low electricity
Usually, it is reduced marked as the voltage value at A, at this point, the first triode Q1 is off state, the second triode Q2 is in and leads
Logical state, after the acceleration electric discharge for passing through the first diode D2 marked as the voltage at B, current voltage value is lower, the voltage at B
When value reduces, after the isolation processing by driving isolation circuit 202, in G sections of just exportable low level driving outputs of switching tube
Signal.It is understood that during the work of entire circuit is done, first resistor R1,3rd resistor R3 and the 4th resistance are
It is pull down resistor to drive resistance, second resistance R2, and the first triode Q1 and the second triode Q2 play the work of electric current distribution
With, the second diode D2 then can carry out rectification to the signal by pulse transformer, meanwhile, third diode D3 is equivalent to one
A zener diode can be used for limiting the amplitude of the signal by pulse transformer, prevent the overtension in circuit.
The backlight source driving circuit that the utility model embodiment provides, dimming controlling module are receiving backlight closing letter
Number when receiving backlight Continuity signal, according to PWM light-adjusting modules feed back current signal, to PWM light-adjusting modules send
PWM Regulate signals, and send drive input signal to isolation drive module；Isolation drive module inputs letter to the driving of reception
Number into horizontal-drive signal processing, output control flyback voltage changing module work drive output signal；Flyback voltage changing module is according to connecing
The alternating voltage of AC power is converted to the DC voltage needed for PWM light-adjusting modules and is supplied to by the drive output signal of receipts
PWM light-adjusting modules；The DC voltage and PWM Regulate signals that PWM light-adjusting modules are provided according to flyback voltage changing module, to backlight
The adjustable output current of output duty cycle, to realize the light modulation to the backlight.Based on the backlight source driving circuit, Neng Gou
When receiving backlight Continuity signal, flyback transforming circuit and PWM light adjusting circuits are controlled using single dimming controlling module, it is real
Show the required voltage that flyback transforming circuit directly exports PWM light modulations, thereby simplifies the topological structure of backlight source driving circuit
And controlling unit, the area of PCB plates occupied by backlight source driving circuit is reduced, it is cost-effective, while also improving backlight drive
The reliability of dynamic circuit.
In addition, the utility model embodiment additionally provides a kind of liquid crystal display, which includes backlight, also
Include the backlight source driving circuit that the utility model above-described embodiment provides, using being integrated with above-mentioned backlight source driving circuit
Liquid crystal display has not only saved cost of manufacture, also the light modulation for realizing backlight of high efficient and reliable.
Note that above are only the preferred embodiment and institute's application technology principle of the utility model.Those skilled in the art's meeting
Understand, the utility model is not limited to specific embodiment described here, can carry out for a person skilled in the art various bright
Aobvious variation is readjusted and is substituted without departing from the scope of protection of the utility model.Therefore, although passing through above example
The utility model is described in further detail, but the utility model is not limited only to above example, is not departing from
Can also include other more equivalent embodiments in the case that the utility model is conceived, and the scope of the utility model is by appended
Right determine.
Claims (10)
1. a kind of backlight source driving circuit, including：Main control module, which is characterized in that further include：Dimming controlling module, isolation
Drive module, flyback voltage changing module and pulse width modulation (PWM) light-adjusting module, wherein
The dimming controlling module is connected with the main control module, also respectively with the PWM light-adjusting modules and isolation drive mould
Block is connected, for when receiving backlight Continuity signal, according to the PWM dim signals that the main control module is sent, to institute
It states PWM light-adjusting modules and sends break-make control signal；And according to the current signal of PWM light-adjusting modules feedback to the isolation
Drive module sends drive input signal；
The isolation drive module is connected with the flyback voltage changing module, is driven for the drive input signal to reception
Signal processing, output control the drive output signal of the flyback voltage changing module work；
The flyback voltage changing module is connected with AC power and the PWM light-adjusting modules respectively, for the driving according to reception
The alternating voltage of AC power is converted to the DC voltage needed for the PWM light-adjusting modules and is supplied to described by output signal
PWM light-adjusting modules；
The PWM light-adjusting modules, are connected with backlight, for being carried according to break-make control signal and the flyback voltage changing module
The DC voltage of confession, to the adjustable output current of backlight output duty cycle, to realize the light modulation to the backlight.
2. circuit according to claim 1, which is characterized in that the dimming controlling module is additionally operable to receiving backlight
When the cut-off signals of source, stop inputting the break-make control signal to the PWM light-adjusting modules, and stop to the isolation drive
Module inputs the drive input signal, to control the PWM light-adjusting modules and the isolation drive module from service.
3. circuit according to claim 1 or 2, which is characterized in that the output end of the AC power becomes with the flyback
The first input end of die block is connected, and the first of the first output end of the flyback voltage changing module and the PWM light-adjusting modules is defeated
Enter end to be connected, the first output end of the PWM light-adjusting modules is connected with the input terminal of the backlight；
The output end of the backlight is connected with the second input terminal of the PWM light-adjusting modules, and the second of the PWM light-adjusting modules
Output end is connected with the second input terminal of the flyback voltage changing module, second output terminal and the friendship of the flyback voltage changing module
The input terminal in galvanic electricity source is connected；
First input end in the dimming controlling module is connected with the third output end of the PWM light-adjusting modules, the light modulation
Second input terminal of control module is connected with the input terminal of the main control module；First output end of the dimming controlling module
It is connected with the third input terminal of the PWM light-adjusting modules；The second output terminal of the dimming controlling module and the isolation drive
The input terminal of module is connected；
The output end of the isolation drive module is connected with the switching tube of the flyback voltage changing module.
4. circuit according to claim 3, which is characterized in that the dimming controlling module is brightness adjustment control chip, described
Brightness adjustment control chip includes：Feedback pin, PWM pins and GATE pins；
The feedback pin is connected with the third output end of the PWM light-adjusting modules, anti-for receiving the PWM light-adjusting modules
The current signal of feedback；
The PWM pins are connected with the main control module output end；Third input terminal with the PWM light-adjusting modules simultaneously
It is connected, the PWM dim signals for being sent according to the main control module generate the break-make for being sent to the PWM light-adjusting modules
Control signal；
The GATE pins are connected with the input terminal of the isolation drive module, the electricity for being received according to the feedback pin
Stream signal generates the drive input signal inputted to the isolation drive module.
5. circuit according to claim 4, which is characterized in that the isolation drive module includes：Totem driving circuit
With driving isolation circuit；
The input terminal of the totem driving circuit is connected with the GATE pins, and the driving for being exported to GATE pins inputs
Signal generates driving treated analog signal into horizontal-drive signal processing；
The input terminal of the driving isolation circuit is connected with the output end of the totem driving circuit, for that will pass through the figure
The analog signal isolating for rising the generation of column driving circuit is transformed into digital signal, and the digital signal is to become for controlling the flyback
The drive output signal of die block work.
6. circuit according to claim 5, which is characterized in that the totem driving circuit, including：First resistor,
Two resistance, the first triode, the second triode, 3rd resistor and the first diode；
The base stage of first triode and the second triode passes through the GATE of first resistor and the brightness adjustment control chip respectively
Pin is connected, meanwhile, the base stage of first triode and the second triode is grounded by the second resistance；
The collector of first triode is connected with direct-flow external power source, the emitter of first triode and described second
The emitter of triode is connected, the grounded collector of second triode；
The 3rd resistor is connected with the input terminal after first diodes in parallel with the emitter of first triode, institute
3rd resistor is stated with the output end after first diodes in parallel to be connected with the input terminal of the driving isolation circuit.
7. circuit according to claim 5, the driving isolation circuit, including：Pulse transformer, the second diode,
Three diodes and the 4th resistance；
The first input end of the pulse transformer is connected with the output end of the totem driving circuit, the pulse transformer
The second input end grounding；
First output end of the pulse transformer is connected with the first end of second diode, and the of the pulse transformer
Two output ends are grounded after being connected with the first end of the third diode；
The second end of second diode and the second end of the third diode respectively by the 4th resistance with it is described
The switching tube of flyback voltage changing module is connected.
8. circuit according to claim 4, the brightness adjustment control chip is at least integrated metal-Oxidc-Semiconductor MOS
The MP3398 of pipe controls chip.
9. circuit according to claim 4, the brightness adjustment control chip is at least the OB3350E chips of external metal-oxide-semiconductor.
10. a kind of liquid crystal display, including backlight, which is characterized in that further include the back of the body described in any one of claim 1-9
Light source driving circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201820412552.7U CN207925111U (en) | 2018-03-26 | 2018-03-26 | Backlight source drive circuit and liquid crystal display |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201820412552.7U CN207925111U (en) | 2018-03-26 | 2018-03-26 | Backlight source drive circuit and liquid crystal display |
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| CN207925111U true CN207925111U (en) | 2018-09-28 |
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| CN201820412552.7U Active CN207925111U (en) | 2018-03-26 | 2018-03-26 | Backlight source drive circuit and liquid crystal display |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109639161A (en) * | 2019-02-21 | 2019-04-16 | 合肥惠科金扬科技有限公司 | Voltage conversion circuit and display device |
| CN111954341A (en) * | 2020-09-03 | 2020-11-17 | 广州彩熠灯光股份有限公司 | Double-frequency control device and method and LED stage lamp |
-
2018
- 2018-03-26 CN CN201820412552.7U patent/CN207925111U/en active Active
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109639161A (en) * | 2019-02-21 | 2019-04-16 | 合肥惠科金扬科技有限公司 | Voltage conversion circuit and display device |
| CN111954341A (en) * | 2020-09-03 | 2020-11-17 | 广州彩熠灯光股份有限公司 | Double-frequency control device and method and LED stage lamp |
| CN111954341B (en) * | 2020-09-03 | 2022-12-09 | 广州彩熠灯光股份有限公司 | Double-frequency control device and method and LED stage lamp |
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Effective date of registration: 20190513 Address after: 510530 3/F 310, 192 Kezhu Road, Guangzhou High-tech Industrial Development Zone, Guangdong Province Patentee after: GUANGZHOU SHIKUN ELECTRONICS Co.,Ltd. Address before: 510530 No. 6, Yunpu Fourth Road, Yunpu Industrial Park, Huangpu District, Guangzhou City, Guangdong Province Patentee before: Guangzhou Shiyuan Electronic Technology Company Limited |