CN105261331A - Backlight driver circuit and display device - Google Patents
Backlight driver circuit and display device Download PDFInfo
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- CN105261331A CN105261331A CN201510700206.XA CN201510700206A CN105261331A CN 105261331 A CN105261331 A CN 105261331A CN 201510700206 A CN201510700206 A CN 201510700206A CN 105261331 A CN105261331 A CN 105261331A
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Abstract
The invention belongs to the field of display control, and provides a backlight driver circuit and a display device. According to the embodiment of the invention, the backlight driver circuit comprises a rectifier and filter circuit, a power calibration circuit, a control circuit, a backlight driver chip, a first transformer T1 and a second transformer T2, wherein the circuit modules are combined and connected in a particular way. On the basis of meeting the requirement of backlight drive, the design of the backlight driver circuit is simplified, and the working efficiency of the backlight driver circuit is improved.
Description
Technical field
The invention belongs to display and control field, particularly relate to a kind of backlight source driving circuit and display device.
Background technology
Backlight (BackLight) is positioned at liquid crystal display (LCD) a kind of light source behind, and its illumination effect will directly have influence on LCD MODULE (LCM) visual effect.Liquid crystal display itself is not luminous, its display graphics or it to light modulation result.
But current backlight source driving circuit generally designs complexity, and efficiency is lower.
Summary of the invention
The invention provides a kind of backlight source driving circuit, be intended to solve existing backlight source driving circuit design complexity, inefficient problem.
In order to solve the problems of the technologies described above, the present invention is achieved in that a kind of backlight source driving circuit, is connected with AC power, and described backlight source driving circuit comprises:
Current rectifying and wave filtering circuit, calibration of power circuit, control circuit, backlight driving chip, the first transformer T1, the second transformer T2;
Described current rectifying and wave filtering circuit is connected with described AC power, and the alternating current that described AC power exports is converted to direct current;
Described calibration of power circuit is connected with described backlight driving chip and described first transformer T1, is undertaken certainly charging by described direct current, controls described first transformer T1 and enter normal operating conditions after charging is full;
Described control circuit is connected with described first transformer T1 and described backlight driving chip, controls described first transformer T1 and generates driving voltage;
Described backlight driving chip is connected with described second transformer T2, drives described driving voltage and exports to drive backlight after being boosted by described driving voltage by described second transformer T2.
Further, described backlight source driving circuit also comprise be connected to described backlight driving chip and described second transformer T2 elementary between electric capacity C1.
Further, described current rectifying and wave filtering circuit comprises:
Rectifier bridge BD1, filter capacitor C2;
The first input end of described rectifier bridge BD1 is connected with described AC power respectively with the second input end, the output terminal of described rectifier bridge BD1 is connected with described calibration of power circuit, the earth terminal ground connection of described rectifier bridge BD1, between the output terminal that described filter capacitor C2 is connected to described rectifier bridge BD1 and earth terminal.
Further, described calibration of power circuit comprises:
Diode D1, diode D2, electrochemical capacitor C3, electrochemical capacitor C4, inductance L 1;
The anode of described diode D1 is connected with the output terminal of described rectifier bridge BD1 respectively with the anode of described diode D2, the first end that the negative electrode of described diode D1 is elementary with described first transformer T1 is connected, the negative electrode of described diode D2 is connected with the first end of described inductance L 1, the second end that second end of described inductance L 2 is elementary with described first transformer T1 is connected, between the negative electrode that described electrochemical capacitor C3 is connected to described diode D1 and ground, the first end of described electrochemical capacitor C4 is connected with the first end of described electrochemical capacitor C3, second end of described electrochemical capacitor C4 is connected with the first input end of described backlight driving chip, the negative electrode of described diode D1 is connected with the second input end of described backlight driving chip.
Further, described control circuit comprises:
PWM chip U1, NMOS tube Q1, diode D3;
The grid of described NMOS tube Q1 is connected with the pulse width modulating signal output terminal of PWM chip U1, the source electrode of described NMOS tube Q1 respectively with the anode of described diode D3 and the three-terminal link of described first transformer T1, the grounded drain of described NMOS tube Q1, the negative electrode of described diode D3 is connected with described backlight driving chip.
Further, described backlight driving chip comprises:
Backlight driving chip U2, NMOS tube Q2, NMOS tube Q3;
The source electrode of described NMOS tube Q2 is that the first input end of described backlight driving chip is connected with the negative electrode of second end of described electrochemical capacitor C4 and described diode D3, the grid of described NMOS tube Q2 is connected with the output terminal of described backlight driving chip U2 respectively with the grid of described NMOS tube Q3, the drain electrode of described NMOS tube Q2 is connected with the source electrode of described NMOS tube Q3, the drain electrode of described NMOS tube Q3 is that the second input end of described backlight driving chip is connected with the negative electrode of described diode D1 and the first end of described electric capacity C1 respectively, the drain electrode of the described NMOS tube Q2 first end elementary with described second transformer T2 with the public connecting end of the source electrode of described NMOS tube Q3 is connected, the second end that second end of described electric capacity C1 is elementary with described second transformer T2 is connected.
Present invention also offers a kind of display device, described display device comprises backlight source driving circuit as above.
In embodiments of the present invention, backlight source driving circuit comprises current rectifying and wave filtering circuit, calibration of power circuit, control circuit, backlight driving chip, the first transformer T1 and the second transformer T2, by foregoing circuit module is connected by ad hoc fashion, the basis meeting backlight driver simplifies the design of backlight source driving circuit, improves the work efficiency of backlight source driving circuit further.
Accompanying drawing explanation
Fig. 1 is the function structure chart of the backlight source driving circuit that the embodiment of the present invention provides;
Fig. 2 is the circuit structure diagram of the backlight source driving circuit that the embodiment of the present invention provides.
Embodiment
In order to make object of the present invention, technical scheme and advantage clearly understand, below in conjunction with drawings and Examples, the present invention is further elaborated.Should be appreciated that specific embodiment described herein only in order to explain the present invention, be not intended to limit the present invention.
Below in conjunction with specific embodiment, specific implementation of the present invention is described in detail:
Fig. 1 shows the modular structure of the backlight source driving circuit that the embodiment of the present invention provides, and for convenience of explanation, only lists the part relevant to the embodiment of the present invention.
As one embodiment of the invention, the backlight source driving circuit that the embodiment of the present invention provides is connected with AC power 200, comprising:
Current rectifying and wave filtering circuit 101, calibration of power circuit 102, control circuit 103, backlight driving chip 104, first transformer T1, the second transformer T2;
Current rectifying and wave filtering circuit 101 is connected with AC power 200, and the alternating current that AC power 200 exports is converted to direct current;
Calibration of power circuit 102 is connected with backlight driving chip 104 and the first transformer T1, and the direct current exported by rectifier bridge BD1 carries out certainly charging, and controls the first transformer T1 and enter normal operating conditions after charging is full;
Control circuit 103 is connected with the first transformer T1 and backlight driving chip 104, controls the first transformer T1 and generates driving voltage;
Backlight driving chip 104 is connected with the second transformer T2, drives this driving voltage and exports to drive backlight after being boosted by driving voltage by the second transformer T2.
As one embodiment of the invention, backlight source driving circuit also comprise be connected to backlight driving chip 104 and the second transformer T2 elementary between electric capacity C1.
Fig. 2 shows the circuit structure of the backlight source driving circuit that the embodiment of the present invention provides, and for convenience of explanation, only lists the part relevant to the embodiment of the present invention.
As one embodiment of the invention, current rectifying and wave filtering circuit 101 comprises:
Rectifier bridge BD1, filter capacitor C2;
The first input end of rectifier bridge BD1 is connected with AC power 200 respectively with the second input end, the output terminal of rectifier bridge BD1 is connected with calibration of power circuit 102, the earth terminal ground connection of rectifier bridge BD1, between the output terminal that filter capacitor C2 is connected to rectifier bridge BD1 and earth terminal.
As one embodiment of the invention, calibration of power circuit 102 comprises:
Diode D1, diode D2, electrochemical capacitor C3, electrochemical capacitor C4, inductance L 1;
The anode of diode D1 is connected with the output terminal of rectifier bridge BD1 respectively with the anode of diode D2, the first end that the negative electrode of diode D1 is elementary with the first transformer T1 is connected, the negative electrode of diode D2 is connected with the first end of inductance L 1, the second end that second end of inductance L 2 is elementary with the first transformer T1 is connected, between the negative electrode that electrochemical capacitor C3 is connected to diode D1 and ground, the first end of electrochemical capacitor C4 is connected with the first end of electrochemical capacitor C3, second end of electrochemical capacitor C4 is connected with the first input end of backlight driving chip, the negative electrode of diode D1 is connected with the second input end of backlight driving chip 104.
As one embodiment of the invention, control circuit 103 comprises:
PWM chip U1, NMOS tube Q1, diode D3;
The grid of NMOS tube Q1 is connected with the pulse width modulating signal output terminal of PWM chip U1, the source electrode of NMOS tube Q1 respectively with the anode of diode D3 and the three-terminal link of the first transformer T1, the grounded drain of NMOS tube Q1, the negative electrode of diode D3 is connected with described backlight driving chip.
As one embodiment of the invention, backlight driving chip 104 comprises:
Backlight driving chip U2, NMOS tube Q2, NMOS tube Q3;
The source electrode of NMOS tube Q2 is that the first input end of backlight driving chip 104 is connected with the negative electrode of second end of electrochemical capacitor C4 and diode D3, the grid of NMOS tube Q2 is connected with the output terminal of backlight driving chip U2 respectively with the grid of NMOS tube Q3, the drain electrode of NMOS tube Q2 is connected with the source electrode of NMOS tube Q3, the drain electrode of NMOS tube Q3 is that the second input end of backlight driving chip 104 is connected with the negative electrode of diode D1 and the first end of electric capacity C1 respectively, the drain electrode of the NMOS tube Q2 first end elementary with the second transformer T2 with the public connecting end of the source electrode of NMOS tube Q3 is connected, the second end that second end of electric capacity C1 is elementary with the second transformer T2 is connected.
In embodiments of the present invention, NMOS tube Q1, NMOS tube Q2 and NMOS tube Q3 can replace by NPN type triode respectively, and annexation is also corresponding to be changed.
Below the principle of work of the backlight source driving circuit that the embodiment of the present invention provides is described.
AC power 200 is in the moment of start, the alternating current that AC power 200 exports is converted to direct current rapidly by current rectifying and wave filtering circuit 101, direct current is charged to electrochemical capacitor C3 by diode D1 rapidly, be formed at running current 10-20 dash current doubly, the duration of charging of electric capacity C2 is relevant with input voltage with the capacity of electric capacity, when the voltage on electric capacity C2 reaches the peak value of input voltage, electric capacity C2 charge cutoff, after electric capacity C2 is full of electric charge, the first transformer T1 enters the state of normal work.
The conducting of PWM chip U1 output pulse signal control Q1 or shutoff, and then control the first transformer T1 generation driving voltage, the size of this driving voltage is determined by the turn ratio of flyback first transformer T1, then backlight driving chip 104 is driven this driving voltage and is boosted by the second transformer T2, voltage after boosting is exported the voltage as driving backlight, and the secondary output one of the first transformer T1 is for standby voltage simultaneously.
Present invention also offers a kind of display device, comprise backlight source driving circuit as above.
In embodiments of the present invention, backlight source driving circuit comprises current rectifying and wave filtering circuit, calibration of power circuit, control circuit, backlight driving chip, the first transformer T1 and the second transformer T2, by foregoing circuit module is connected by ad hoc fashion, the basis meeting backlight driver simplifies the design of backlight source driving circuit, improves the work efficiency of backlight source driving circuit further.
The foregoing is only preferred embodiment of the present invention, not in order to limit the present invention, all any amendments done within the spirit and principles in the present invention, equivalent replacement and improvement etc., all should be included within protection scope of the present invention.
Claims (7)
1. a backlight source driving circuit, is connected with AC power, it is characterized in that, described backlight source driving circuit comprises:
Current rectifying and wave filtering circuit, calibration of power circuit, control circuit, backlight driving chip, the first transformer T1, the second transformer T2;
Described current rectifying and wave filtering circuit is connected with described AC power, and the alternating current that described AC power exports is converted to direct current;
Described calibration of power circuit is connected with described backlight driving chip and described first transformer T1, is undertaken certainly charging by described direct current, controls described first transformer T1 and enter normal operating conditions after charging is full;
Described control circuit is connected with described first transformer T1 and described backlight driving chip, controls described first transformer T1 and generates driving voltage;
Described backlight driving chip is connected with described second transformer T2, drives described driving voltage and exports to drive backlight after being boosted by described driving voltage by described second transformer T2.
2. backlight source driving circuit as claimed in claim 1, is characterized in that, described backlight source driving circuit also comprise be connected to described backlight driving chip and described second transformer T2 elementary between electric capacity C1.
3. backlight source driving circuit as claimed in claim 2, it is characterized in that, described current rectifying and wave filtering circuit comprises:
Rectifier bridge BD1, filter capacitor C2;
The first input end of described rectifier bridge BD1 is connected with described AC power respectively with the second input end, the output terminal of described rectifier bridge BD1 is connected with described calibration of power circuit, the earth terminal ground connection of described rectifier bridge BD1, between the output terminal that described filter capacitor C2 is connected to described rectifier bridge BD1 and earth terminal.
4. passive PFC backlight driving chip as claimed in claim 3, is characterized in that, described calibration of power circuit comprises:
Diode D1, diode D2, electrochemical capacitor C3, electrochemical capacitor C4, inductance L 1;
The anode of described diode D1 is connected with the output terminal of described rectifier bridge BD1 respectively with the anode of described diode D2, the first end that the negative electrode of described diode D1 is elementary with described first transformer T1 is connected, the negative electrode of described diode D2 is connected with the first end of described inductance L 1, the second end that second end of described inductance L 2 is elementary with described first transformer T1 is connected, between the negative electrode that described electrochemical capacitor C3 is connected to described diode D1 and ground, the first end of described electrochemical capacitor C4 is connected with the first end of described electrochemical capacitor C3, second end of described electrochemical capacitor C4 is connected with the first input end of described backlight driving chip, the negative electrode of described diode D1 is connected with the second input end of described backlight driving chip.
5. backlight source driving circuit as claimed in claim 4, it is characterized in that, described control circuit comprises:
PWM chip U1, NMOS tube Q1, diode D3;
The grid of described NMOS tube Q1 is connected with the pulse width modulating signal output terminal of PWM chip U1, the source electrode of described NMOS tube Q1 respectively with the anode of described diode D3 and the three-terminal link of described first transformer T1, the grounded drain of described NMOS tube Q1, the negative electrode of described diode D3 is connected with described backlight driving chip.
6. backlight source driving circuit as claimed in claim 5, it is characterized in that, described backlight driving chip comprises:
Backlight driving chip U2, NMOS tube Q2, NMOS tube Q3;
The source electrode of described NMOS tube Q2 is that the first input end of described backlight driving chip is connected with the negative electrode of second end of described electrochemical capacitor C4 and described diode D3, the grid of described NMOS tube Q2 is connected with the output terminal of described backlight driving chip U2 respectively with the grid of described NMOS tube Q3, the drain electrode of described NMOS tube Q2 is connected with the source electrode of described NMOS tube Q3, the drain electrode of described NMOS tube Q3 is that the second input end of described backlight driving chip is connected with the negative electrode of described diode D1 and the first end of described electric capacity C1 respectively, the drain electrode of the described NMOS tube Q2 first end elementary with described second transformer T2 with the public connecting end of the source electrode of described NMOS tube Q3 is connected, the second end that second end of described electric capacity C1 is elementary with described second transformer T2 is connected.
7. a display device, is characterized in that, described display device comprises the backlight source driving circuit as described in claim 1-6.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510700206.XA CN105261331A (en) | 2015-10-26 | 2015-10-26 | Backlight driver circuit and display device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510700206.XA CN105261331A (en) | 2015-10-26 | 2015-10-26 | Backlight driver circuit and display device |
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| Publication Number | Publication Date |
|---|---|
| CN105261331A true CN105261331A (en) | 2016-01-20 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510700206.XA Pending CN105261331A (en) | 2015-10-26 | 2015-10-26 | Backlight driver circuit and display device |
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| CN (1) | CN105261331A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105741788A (en) * | 2016-04-22 | 2016-07-06 | 青岛海信电器股份有限公司 | Backlight drive circuit and display apparatus |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN202435665U (en) * | 2011-12-20 | 2012-09-12 | 成都成电硅海科技股份有限公司 | LED constant-current driving circuit with high power factor |
| CN203398989U (en) * | 2013-08-06 | 2014-01-15 | 惠科电子（深圳）有限公司 | Flat television power supply |
| CN203397670U (en) * | 2013-08-07 | 2014-01-15 | 惠科电子（深圳）有限公司 | Passive PFC backlight driving circuit and flat panel television |
-
2015
- 2015-10-26 CN CN201510700206.XA patent/CN105261331A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN202435665U (en) * | 2011-12-20 | 2012-09-12 | 成都成电硅海科技股份有限公司 | LED constant-current driving circuit with high power factor |
| CN203398989U (en) * | 2013-08-06 | 2014-01-15 | 惠科电子（深圳）有限公司 | Flat television power supply |
| CN203397670U (en) * | 2013-08-07 | 2014-01-15 | 惠科电子（深圳）有限公司 | Passive PFC backlight driving circuit and flat panel television |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105741788A (en) * | 2016-04-22 | 2016-07-06 | 青岛海信电器股份有限公司 | Backlight drive circuit and display apparatus |
| CN105741788B (en) * | 2016-04-22 | 2018-08-07 | 青岛海信电器股份有限公司 | Backlight drive circuit and display device |
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