CN104185344B - Control circuit for light source, backlight module and display device - Google Patents
Control circuit for light source, backlight module and display device Download PDFInfo
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- CN104185344B CN104185344B CN201410400829.0A CN201410400829A CN104185344B CN 104185344 B CN104185344 B CN 104185344B CN 201410400829 A CN201410400829 A CN 201410400829A CN 104185344 B CN104185344 B CN 104185344B
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Abstract
The invention discloses a kind of control circuit for light source, backlight module and display device, relate to Display Technique field, it is possible to avoid light-source temperature too high, not only improve the reliability of backlight module, also reduce the fault rate of backlight module simultaneously.This control circuit for light source includes booster circuit, temperature sensitive member and control unit, booster circuit includes chip and sampling unit, the outfan of chip is connected to sampling unit, sampling unit is connected to the feedback end of chip, and sampling unit is for sampling to the output voltage of chip and exporting sampled voltage to the feedback end of chip.Control unit is for when the temperature that temperature sensitive member senses is more than preset value, the sampled voltage controlling sampling unit output increases, control unit is additionally operable to when the temperature that temperature sensitive member senses is less than preset value, and the sampled voltage controlling sampling unit output reduces.
Description
Technical field
The present invention relates to Display Technique field, particularly relate to a kind of control circuit for light source, backlight module and display
Device.
Background technology
In a display device, generally providing backlight by backlight module, the light source in backlight module is by all
Impact such as the factor such as impedance fluctuations, ambient temperature, it is possible to light-source temperature can be caused too high, thus cause
The reduction of backlight module reliability and the increase of fault rate.Existing light source is driven by Boost circuit
Realizing luminescence, Boost circuit is generally by feedback regulation output voltage, so that output voltage tends towards stability,
Owing to the output voltage of Boost circuit determines the brightness of light source, avoid the most to a certain extent because of
This light-source brightness increases the too high problem of temperature caused.But, the scope of Boost circuit feedback regulation has
Limit, therefore, the most still lacks effective means to prevent light-source temperature too high.
Summary of the invention
The present invention provides a kind of control circuit for light source, backlight module and display device, it is possible to avoid light-source temperature
Too high, not only improve the reliability of backlight module, also reduce the fault rate of backlight module simultaneously.
For reaching above-mentioned purpose, the present invention adopts the following technical scheme that
First aspect, it is provided that a kind of control circuit for light source, including:
Booster circuit, described booster circuit includes that chip and sampling unit, the outfan of described chip are connected to
Described sampling unit, described sampling unit is connected to the feedback end of described chip, and described sampling unit is for right
The output voltage of described chip is sampled and exports the feedback end of sampled voltage extremely described chip.
Temperature sensitive member.
Being connected to described temperature sensitive member and the control unit of described sampling unit, described control unit is used for
When the temperature that described temperature sensitive member senses is more than preset value, control adopting of described sampling unit output
Sample voltage increases, and described control unit is additionally operable to preset when the temperature that described temperature sensitive member senses is less than
During value, the sampled voltage controlling the output of described sampling unit reduces.
Alternatively, described sampling unit includes the first division module and the second division module, described first dividing potential drop
First end of module is connected to the outfan of described chip, and the second end of described first division module is connected to institute
Stating the feedback end of chip, the first end of described second division module is connected to the feedback end of described chip, described
Second end ground connection of the second division module.
Alternatively, described control unit is connected to described second division module, and described control unit is for working as institute
When stating temperature that temperature sensitive member senses more than preset value, the impedance controlling described second division module increases
Greatly, described control unit, for when the temperature that temperature sensitive member senses is less than preset value, controls described
The impedance of the second division module reduces.
Specifically, described first division module includes that the first resistance, the first end of described first resistance are connected to
The outfan of described chip, the second end of described first resistance is connected to the feedback end of described chip.
Alternatively, described second division module includes the second resistance, the 3rd resistance and switching tube, described second
First end of resistance is connected to the feedback end of described chip, the second end ground connection of described second resistance, and described
First end of three resistance is connected to the feedback end of described chip, and the first end of described switching tube is connected to described
Second end of three resistance, the second end ground connection of described switching tube.
Specifically, described control unit is connected to the control end of described switching tube, and described control unit is for defeated
Going out the control end of pulse signal extremely described switching tube, the temperature sensed when described temperature sensitive member is more than pre-
If during value, described control unit controls the dutycycle of described pulse signal and reduces, when temperature sensitive member senses
When the temperature arrived is less than preset value, described control unit controls the dutycycle of described pulse signal and increases.
Specifically, described second division module also includes electric capacity, and the first end of described electric capacity is connected to described core
The feedback end of sheet, the second end ground connection of described electric capacity.
Specifically, described control unit is single-chip microcomputer, and described temperature sensitive member is critesistor, described in open
Close pipe to manage for MOS (Metal-Oxide-Semiconductor, metal-oxide semiconductor (MOS)), described switching tube
First end is the drain electrode of described metal-oxide-semiconductor, the source electrode that the second end is described metal-oxide-semiconductor of described switching tube, institute
That states switching tube controls the grid that end is described switching tube.
Second aspect, additionally provides a kind of backlight module, including light source, also includes above-mentioned light source control electricity
Road, in described control circuit for light source, the chip output of booster circuit is connected to described light source.
The third aspect, additionally provides a kind of display device, including described backlight module.
Control circuit for light source, backlight module and the display device that the present invention provides, first passes through the temperature in circuit
Sensing element senses the temperature of light source in real time and compares with default standard temperature, if light-source temperature is high
In default standard value, then increase sampling unit by the control unit in circuit and export chip feedback end
Sampled voltage, thus reduce the output voltage of chip output, it is to avoid the too high phenomenon of light-source temperature is sent out
Raw, not only improve the reliability of backlight module, and reduce the fault rate of backlight module.
Accompanying drawing explanation
For the technical scheme being illustrated more clearly that in the embodiment of the present invention, below will be to required in embodiment
The accompanying drawing used is briefly described, it should be apparent that, the accompanying drawing in describing below is only the one of the present invention
A little embodiments, for those of ordinary skill in the art, on the premise of not paying creative work, also
Other accompanying drawing can be obtained according to these accompanying drawings.
The schematic diagram of a kind of control circuit for light source that Fig. 1 provides for the embodiment of the present invention；
The schematic diagram of the another kind of control circuit for light source that Fig. 2 provides for the embodiment of the present invention.
Detailed description of the invention
Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is carried out clearly
Chu, be fully described by, it is clear that described embodiment be only a part of embodiment of the present invention rather than
Whole embodiments.Based on the embodiment in the present invention, those of ordinary skill in the art are not making creation
The every other embodiment obtained under property work premise, broadly falls into the scope of protection of the invention.
As it is shown in figure 1, the embodiment of the present invention provides a kind of control circuit for light source, including: booster circuit 1, temperature
Spend sensing element 2 and be connected to temperature sensitive member 2 and control unit 3.
Booster circuit 1 includes chip 11 and sampling unit 12, and the output end vo ut of chip 11 is connected to sampling
Unit 12, sampling unit 12 is connected to the feedback end FB of chip 11, and sampling unit 12 is for chip 11
Output voltage sample and export sampled voltage to the feedback end FB of chip 11.
Control unit 3 is for when the temperature that temperature sensitive member 2 senses is more than preset value, controlling sampling
The sampled voltage of unit 12 output increases, and control unit 3 is additionally operable to the temperature when temperature sensitive member 2 senses
When degree is less than preset value, the sampled voltage controlling sampling unit 12 output reduces.
Specifically, above-mentioned control circuit for light source is used for being controlled the light source in backlight module, booster circuit 1
For driving light source, the outfan of chip 11 is connected to light source (not shown), the output electricity of chip 11
Pressure is the driving voltage of light source.Chip 11 by sampled voltage is compared with reference voltage, and according to
The output voltage of comparative result regulation chip 11.Temperature in temperature sensitive member 2 inductive backlight module, when
When this temperature is more than preset value, illustrate that the temperature of backlight module, higher than ideal temperature, now controls sampling unit
The sampled voltage of 12 outputs increases, and sampled voltage is relatively big compared with reference voltage, and therefore chip 11 regulation makes defeated
Go out voltage to reduce, i.e. reduce temperature by the driving voltage of reduction light source, prevent backlight module temperature with this
Spend height, the brightness of light source can be reduced simultaneously；The temperature sensed when temperature sensitive member 2 is less than preset value
Time, illustrating that the temperature of backlight module is relatively low, the sampled voltage now controlling sampling unit 12 output reduces, and adopts
Sample voltage is less compared with reference voltage, and therefore chip 11 regulation makes output voltage increase, and increases driving of light source
Galvanic electricity pressure is so that light-source brightness recovers normal.
Control circuit for light source in the present embodiment, first passes through the temperature sensitive member in circuit and senses light in real time
The temperature in source also compares with default standard temperature, if light-source temperature is higher than the standard value preset, then leads to
Control unit in oversampling circuit increases sampling unit and exports the sampled voltage of chip feedback end, thus reduces
The output voltage of chip output, it is to avoid the too high phenomenon of light-source temperature occurs, and not only improves backlight mould
The reliability of group, and reduce the fault rate of backlight module.
As in figure 2 it is shown, concrete, above-mentioned sampling unit can include the first division module 121 and second point
Die block 122, the first end of the first division module 121 is connected to the output end vo ut of chip 11, first point
Second end of die block 121 is connected to the feedback end FB of chip 11, the first end of the second division module 122
It is connected to the feedback end FB of chip 11, the second end ground connection of the second division module 122；Control unit 3 is even
Being connected to the second division module 122, control unit 3 is more than pre-for the temperature sensed when temperature sensitive member 2
If during value, the impedance controlling the second division module 122 increases, and control unit 3 is for when temperature sensitive member 2
When the temperature sensed is less than preset value, the impedance controlling the second division module 122 reduces.
First division module 121 and the second division module 122 are used for the output voltage of chip 11 is carried out dividing potential drop,
Voltage at feedback end FB is the sampled voltage after dividing potential drop, and sampled voltage is by the first division module 121 and
The impedance proportionate relationship of two division module 122 obtains, and chip 11 is by carrying out sampled voltage with reference voltage
Relatively, the output voltage of chip 11 and is regulated according to comparative result.When the impedance of the second division module 122 increases
Time big, the impedance of the first division module 121 is constant, hence in so that sampled voltage increases, and sampled voltage and ginseng
Examining voltage and compare relatively big, therefore chip 11 can regulate and make output voltage reduce；When the second division module 122
When impedance reduces, the impedance of the first division module 121 is constant, hence in so that sampled voltage reduces, and sampling electricity
Pressing less compared with reference voltage, therefore chip 11 can regulate and make output voltage increase.
Alternatively, the first division module 121 can include the first resistance R1, first end of the first resistance R1
The second end being connected to the output end vo ut of chip 11, the first resistance R1 is connected to the feedback end of chip 11；
Second division module 122 can include the second resistance R2, the 3rd resistance R3 and switching tube M1, the second resistance
First end of R2 is connected to the second end ground connection of the feedback end FB of chip 11, the second resistance R2, the 3rd electricity
First end of feedback end FB, switching tube M1 that first end of resistance R3 is connected to chip 11 is connected to the 3rd electricity
Second end of resistance R3, the second end ground connection of switching tube M1；Control unit 3 is connected to the control of switching tube M1
End processed, control unit 3 is for the control end of output pulse signal to switching tube M1, when temperature sensitive member 2
When the temperature sensed is more than preset value, the dutycycle of control unit 3 control wave reduces, and works as temperature
When the temperature that sensing element 2 senses is less than preset value, control unit 3 controls the duty of control wave
Than increasing.
Wherein, described dutycycle is the explanation of the amplification to automatically controlled pulsewidth modulation, and dutycycle substantially refers to controlled
The time that the circuit of system is switched on accounts for the percentage ratio of whole circuit working cycle.In the present embodiment, dutycycle
Referring to that in pulse signal, the persistent period of conduction level is at a cycle proportion, conduction level refers to control
The level of switching tube M1 conducting.During switching tube M1 cut-off, the impedance of the second division module 122 is the second electricity
Resistance R2 impedance, switching tube M1 conducting time, the impedance of the second division module 122 be the second resistance R2 and
The impedance that 3rd resistance R3 is in parallel, i.e. during switching tube M1 cut-off, the impedance of the second division module 122 is more than opening
The impedance of the second division module 122 when closing pipe M2 conducting.Switching tube M1 is leading according to the control of pulse signal
Lead to and change between cut-off state, when the dutycycle of pulse signal reduces, the resistance of the second division module 122
Anti-increase, when the dutycycle of pulse signal increases, the impedance of the second division module 122 reduces.
Alternatively, the second division module 122 can also include that first end of electric capacity C1, electric capacity C1 is connected to
The second end ground connection of the feedback end FB of chip 11, electric capacity C1.Wherein, the effect of described electric capacity is used to surely
Determine the sampled voltage in circuit.
Specifically, described control unit 3 can be single-chip microcomputer, it is also possible to be that other can realize described control list
The device of unit's 3 functions or equipment.
Specifically, described temperature sensitive member 2 can be critesistor.
Specifically, described switching tube M1 can be metal-oxide-semiconductor, and first end of described switching tube M1 is MOS
The drain electrode of pipe, second end of described switching tube M1 is the source electrode of metal-oxide-semiconductor, the control of described switching tube M1
End is the grid of described switching tube M1.Switching tube M1 can also be IGBT (Insulated Gate Bipolar
Transistor, insulated gate bipolar transistor) etc. other switching devices.
Below by way of a concrete light source control method, above-mentioned control circuit for light source is described.
Specifically, the temperature in temperature sensitive member 2 inductive backlight module, when this temperature is more than preset value,
Illustrating that the temperature of backlight module is higher than ideal temperature, now the dutycycle of control unit 3 control wave subtracts
Little, though the second division module 122 impedance increase so that sampled voltage increase, sampled voltage with
Reference voltage is compared relatively big, and therefore chip 11 regulation makes output voltage reduce, i.e. by reducing the driving of light source
Voltage reduces temperature, prevents backlight module temperature too high with this, can reduce the brightness of light source simultaneously；When
When the temperature that temperature sensitive member 2 senses is less than preset value, illustrate that the temperature of backlight module is relatively low, now
The dutycycle of those remote 3 control waves such as control increases, even if the impedance of the second division module 122 reduces,
So that sampled voltage reduces, sampled voltage is less compared with reference voltage, and therefore chip 11 regulation makes defeated
Go out voltage to increase, increase the driving voltage of light source so that light-source brightness recovers normal.
Control circuit for light source in the present embodiment, first passes through the temperature sensitive member in circuit and senses light in real time
The temperature in source also compares with default standard temperature, if light-source temperature is higher than the standard value preset, then leads to
Control unit in oversampling circuit increases sampling unit and exports the sampled voltage of chip feedback end, thus reduces
The output voltage of chip output, it is to avoid the too high phenomenon of light-source temperature occurs, and not only improves backlight mould
The reliability of group, and reduce the fault rate of backlight module.
The present invention also provides for a kind of backlight module, including light source, also includes above-mentioned control circuit for light source, light
In source control circuit, the chip output of booster circuit is connected to this light source.This light source is preferably LED (Light
Emitting Diode, light emitting diode).
Wherein concrete structure and the principle of control circuit for light source are same as the previously described embodiments, do not repeat them here.
The present invention also provides for a kind of display device, including above-mentioned backlight module.
This display device can be: display panels, mobile phone, panel computer, television set, display,
Notebook computer, DPF, navigator etc. are any to be provided backlight by backlight module and has display merit
The product of energy or parts.
Above, the only detailed description of the invention of the present invention, but protection scope of the present invention is not limited thereto,
Any those familiar with the art, in the technical scope that the invention discloses, can readily occur in change
Or replace, all should contain within protection scope of the present invention.Therefore, protection scope of the present invention Ying Yiquan
The protection domain that profit requires is as the criterion.
Claims (8)
1. a control circuit for light source, it is characterised in that including:
Booster circuit, described booster circuit includes that chip and sampling unit, the outfan of described chip are connected to
Described sampling unit, described sampling unit is connected to the feedback end of described chip, and described sampling unit is for right
The output voltage of described chip is sampled and exports the feedback end of sampled voltage extremely described chip；
Temperature sensitive member；
Being connected to described temperature sensitive member and the control unit of described sampling unit, described control unit is used for
When the temperature that described temperature sensitive member senses is more than preset value, control adopting of described sampling unit output
Sample voltage increases, and described control unit is additionally operable to preset when the temperature that described temperature sensitive member senses is less than
During value, the sampled voltage controlling the output of described sampling unit reduces,
Described sampling unit includes the first division module and the second division module, the of described first division module
One end is connected to the outfan of described chip, and the second end of described first division module is connected to described chip
Feedback end；Described second division module includes the second resistance, the 3rd resistance and switching tube, described second resistance
The first end be connected to the feedback end of described chip, the second end ground connection of described second resistance, described 3rd electricity
First end of resistance is connected to the feedback end of described chip, and the first end of described switching tube is connected to described 3rd electricity
Second end of resistance, the second end ground connection of described switching tube；Described control unit is connected to the control of described switching tube
End processed, described control unit is for the control end of output pulse signal to described switching tube, when described temperature sense
When the temperature answering element senses to arrive is more than preset value, described control unit controls the dutycycle of described pulse signal
Reducing, when the temperature that temperature sensitive member senses is less than preset value, described control unit controls described arteries and veins
The dutycycle rushing signal increases.
Control circuit for light source the most according to claim 1, it is characterised in that
Described first division module includes that the first resistance, the first end of described first resistance are connected to described chip
Outfan, the second end of described first resistance is connected to the feedback end of described chip.
Control circuit for light source the most according to claim 1, it is characterised in that
Described second division module also includes that electric capacity, the first end of described electric capacity are connected to the feedback of described chip
End, the second end ground connection of described electric capacity.
Control circuit for light source the most as claimed in any of claims 1 to 3, it is characterised in that
Described control unit is single-chip microcomputer.
Control circuit for light source the most as claimed in any of claims 1 to 3, it is characterised in that
Described temperature sensitive member is critesistor.
Control circuit for light source the most according to claim 1, it is characterised in that
Described switching tube is metal-oxide-semiconductor, the drain electrode that the first end is described metal-oxide-semiconductor of described switching tube, described
The source electrode that second end is described metal-oxide-semiconductor of switching tube, the grid that control end is described switching tube of described switching tube
Pole.
7. a backlight module, including light source, it is characterised in that also include as appointed in claim 1 to 6
Anticipating a described control circuit for light source, in described control circuit for light source, the chip output of booster circuit connects
In described light source.
8. a display device, it is characterised in that include backlight module as claimed in claim 7.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410400829.0A CN104185344B (en) | 2014-08-14 | 2014-08-14 | Control circuit for light source, backlight module and display device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410400829.0A CN104185344B (en) | 2014-08-14 | 2014-08-14 | Control circuit for light source, backlight module and display device |
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| Publication Number | Publication Date |
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| CN104185344A CN104185344A (en) | 2014-12-03 |
| CN104185344B true CN104185344B (en) | 2016-11-16 |
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Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN106354075B (en) * | 2016-11-25 | 2020-01-21 | 北京意同创科技有限公司 | Remote controller control circuit with backlight screen |
| CN107196546B (en) * | 2017-06-09 | 2023-12-26 | 苏州汇川联合动力***股份有限公司 | Active discharge system of motor controller |
| CN107256697A (en) * | 2017-07-31 | 2017-10-17 | 昆山龙腾光电有限公司 | Backlight drive circuit |
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| CN1373632A (en) * | 2001-03-06 | 2002-10-09 | 北京金燕莱科工贸有限责任公司 | Voltage-limiting current-stabilizing device for fluorescent lamp of aircraft |
| JP5757683B2 (en) * | 2006-12-11 | 2015-07-29 | コーニンクレッカ フィリップス エヌ ヴェ | Method and apparatus for digital control of lighting devices |
| CN102202447A (en) * | 2011-04-22 | 2011-09-28 | 威海东兴电子有限公司 | Heat-resistant and lightning proof LED driving power supply without electrolytic capacitor |
| CN102762011B (en) * | 2011-04-29 | 2015-03-11 | 海洋王照明科技股份有限公司 | LED (Light Emitting Diode) constant-current dimming drive circuit device |
| CN203102140U (en) * | 2013-01-06 | 2013-07-31 | 青岛海信宽带多媒体技术有限公司 | Device capable of dynamically adjusting power |
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