CN109637469A - Backlight regulating circuit - Google Patents
Backlight regulating circuit Download PDFInfo
- Publication number
- CN109637469A CN109637469A CN201910124997.4A CN201910124997A CN109637469A CN 109637469 A CN109637469 A CN 109637469A CN 201910124997 A CN201910124997 A CN 201910124997A CN 109637469 A CN109637469 A CN 109637469A
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- Prior art keywords
- backlight
- coupled
- pin
- resistance
- chip
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- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
- G09G3/3406—Control of illumination source
-
- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
- G09G3/3406—Control of illumination source
- G09G3/3413—Details of control of colour illumination sources
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- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Computer Hardware Design (AREA)
- General Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Circuit Arrangement For Electric Light Sources In General (AREA)
Abstract
A kind of backlight regulating circuit, brightness for the backlight to display is adjusted, the backlight regulating circuit includes photoinduction chip and backlight driving chip, the backlight driving chip is coupled to the backlight, the backlight regulating circuit further includes conversion circuit, the conversion circuit is coupled respectively to the photoinduction chip and backlight driving chip, and the enhancing or reduction of the photoinduction chip induction external environment light intensity are converted to increasing or reducing for current signal and are input to conversion circuit；Conversion circuit by the current signal received increase or reduce be converted to voltage signal output is decreased or increased to backlight driving chip, backlight driving chip corresponding adjust output and increases or reduces to the electric current of the backlight to adjust the luminous brightness of the backlight according to being decreased or increased for the voltage signal received.The backlight regulating circuit structure is simple and can carry out backlight adjusting without occupying central processing unit additional pin.
Description
Technical field
The present invention relates to a kind of backlight regulating circuits, more particularly to a kind of backlight adjusting electricity only realized by hardware circuit
Road.
Background technique
Currently, being provided with backlight on certain portable electronic devices to save electric power to extend the time that uses of battery
Circuit is adjusted, the light emitting diode (Light of the backlight module of portable electronic device is adjusted by ambient brightness
Emitting Diode, LED) brightness, with achieve the purpose that save electric power.
Existing backlight regulating circuit generally comprises central processing unit, optical inductor and liquid crystal display (Liquid
Crystal Display, LCD) backlight driving chip.The intensity of illumination of the optical inductor sensing external environment, then by light
Signal is converted to analog electrical signal, such as an ADC pin of current value input central processing unit, the ADC pin are connected to
Analog-digital converter inside central processing unit, the analog-digital converter read the analog electrical signal that optical inductor is sent,
And it is converted into digital signal, central processing unit passes through the luminous intensity of obtained digital signal judgement at this time, and via pulse width
Pin output pulse width modulated signal is modulated to adjust the output of LCD backlight driving chip, to change the bright of backlight LED
Degree.
But above-mentioned backlight regulating circuit needs to occupy an ADC pin and a pulse width tune for central processing unit
Pin processed is unfavorable for the expansion of other additional functions of central processing unit.In addition, in order to realize above-mentioned backlight regulating circuit
Backlight regulatory function needs to make pair between analog current value, light and pulse width modulating signal three on software
It should be related to, software design is more complex, needs to occupy software engineer's more time in software design, increases design cost.
Summary of the invention
In view of this, and a kind of backlight tune without occupy central processing unit additional pin simple it is necessary to provide circuit
Economize on electricity road.
A kind of backlight regulating circuit, the brightness for the backlight to display are adjusted, the backlight regulating circuit
Including photoinduction chip and backlight driving chip, which is coupled to the backlight, the backlight regulating circuit
It further include conversion circuit, the conversion circuit is coupled respectively to the photoinduction chip and backlight driving chip, the photoinduction core
The enhancing or reduction of piece induction external environment light intensity are converted to increasing or reducing for current signal and are input to conversion circuit；
Conversion circuit by the current signal received increase or reduce be converted to voltage signal be decreased or increased output give backlight drive
Dynamic chip, backlight driving chip are exported according to corresponding adjust that be decreased or increased of the voltage signal received to the backlight
Electric current is increased or reduced to adjust the luminous brightness of the backlight.
The backlight regulating circuit incudes the variation of external environment light intensity by the photoinduction chip, and
The electric signal that the variation of external environment light intensity is converted to variation is reflected into conversion circuit, conversion circuit is by the photoinduction
The electric signal of the variation of chip transmission is sent to the backlight driving chip, then by backlight driving chip according to the electricity of the variation
Signal adjusts its own output, to realize the adjusting to display backlight.Described in the backlight regulating circuit uses
The variation of photoinduction chip, backlight driving chip, the electronic components electric signal such as conversion circuit itself reach display backlight
The purpose of adjusting, circuit are simple and without occupying central processing unit additional pin.
Detailed description of the invention
Fig. 1 is the circuit diagram of the backlight regulating circuit of better embodiment of the present invention.
Main element symbol description
Backlight regulating circuit 100
Backlight drive circuit 10
Backlight driving chip 11
Photoinduction circuit 20
Photoinduction chip 21
Conversion circuit 30
Amplifying circuit 31
Input terminal 311
Output end 313
Power supply 33
Backlight 200
LED 210
First divider resistance R11
Feedback resistance R12
Adjust resistance R21
First resistor R31
Second resistance R32
Second divider resistance R33
Third divider resistance R34
First filter capacitor C11
Second filter capacitor C31
Inductance L11
PNP type triode Q31
Voltage input pin VIN
Voltage output pin VOUT
Feedback pin FB
Switch pin SW
Enabled pin EN
LED adjustment pin ILED
First grounding pin GND
Second grounding pin PGND
Drive input pin VDD
Pin SET is set
Inductive output pin VO
Cell voltage VBAT
Grounding pin GND.
Specific embodiment
Referring to Fig. 1, the backlight regulating circuit 100 of better embodiment of the present invention is used for, to driving display, (figure is not
Show) backlight 200 shine, while the light emission luminance of the backlight 200 is adjusted according to the variation of external environment light.
The backlight regulating circuit 100 includes backlight drive circuit 10, photoinduction circuit 20 and conversion circuit 30.The backlight drive
Circuit 10 is for driving the backlight 200 to shine.The conversion circuit 30 is coupled to the backlight drive circuit 10 and photoinduction electricity
Road 20.The photoinduction circuit 20 incudes the variation of external environment light intensity, and by the enhancing of external environment light intensity or
Reduction is converted to increasing or reducing for current signal and is input to conversion circuit 30；The current signal that conversion circuit 30 will receive
Increase or reduce and be converted into being decreased or increased for voltage signal and be transferred to backlight drive circuit 10；Backlight drive circuit 10 according to
It increases or reduces according to the corresponding adjusting output that is decreased or increased of the voltage signal received to the electric current of the backlight 200 to adjust
The luminous brightness of the backlight 200 is saved, realizes the adjusting to display backlight.
The backlight drive circuit 10 includes backlight driving chip 11, the first divider resistance R11, feedback resistance R12, electricity
Feel L11 and the first filter capacitor C11.The model of the backlight driving chip 11 can be TPS61062YZFR etc..The backlight
Driving chip 11 includes voltage input pin VIN, voltage output pin VOUT, feedback pin FB, switching pin SW, enables to draw
Foot EN, LED adjustment pin ILED, the first grounding pin GND and the second grounding pin PGND.The voltage input pin VIN,
Enabled pin EN and LED adjustment pin ILED accesses the cell voltage VBAT of battery (not shown) offer；The voltage is defeated
Pin VOUT is coupled to the input terminal of backlight 200 out；Feedback pin FB is coupled to described by the feedback resistance R12
The output end of backlight 200；The first grounding pin GND and the second grounding pin PGND are grounded.The backlight driving chip
The cell voltage VBAT is converted into output voltage by 11, and is exported via voltage output pin VOUT to the backlight
200, to drive the backlight 200 to shine.The backlight driving chip 11 detects the backlight 200 by feedback pin FB
Whether the voltage of output end is preset standard value.If feedback pin FB detects the voltage of 200 output end of backlight
Lower than preset standard value, which then will increase the electric current of voltage output pin VOUT output, to back
The compensation of the progress driving current of light source 200.
Described one end first divider resistance R11 is coupled between feedback resistance R12 and the backlight 200, another termination
Ground.The first divider resistance R11 is for dividing the output voltage of the backlight driving chip 11, so that the backlight 200
Obtain specified driving voltage.Cell voltage VBAT is accessed in the one end inductance L11, and the other end is coupled to the backlight drive core
The switching pin SW of piece 11.The inductance L11 is stored for the cell voltage VBAT energy provided, to increase the backlight
The output voltage of driving chip 11.In this better embodiment, the number of the first filter capacitor C11 is two.Wherein
One first one end filter capacitor C11 is coupled to the voltage input pin VIN, enabled pin EN and LED adjustment pin
ILED, other end ground connection.Another one end the first filter capacitor C11 is coupled to the voltage output pin VOUT and the back
Between light source 200, other end ground connection.Described two first filter capacitor C11 are respectively used to the input to the backlight driving chip
Voltage and output voltage are filtered.
The photoinduction circuit 20 includes photoinduction chip 21 and adjusting resistance R21.The model of the photoinduction chip 21
It can be CM3204B3OR etc..The photoinduction chip 21 includes driving input pin VDD, setting pin SET, inductive output
Pin VO and grounding pin GND.The driving input pin VDD accesses input voltage；The setting pin SET series connection tune
Economize on electricity resistance R21 is extremely；The inductive output pin VO and grounding pin GND are grounded.Outside the photoinduction chip 21 senses
When portion's ambient light becomes strong, biggish operating current is needed, i.e., can be become via the electric current that the driving input pin VDD is inputted
Greatly；When the photoinduction chip 21 senses that external environment light dies down, operating current can become smaller, i.e., defeated via the driving
The electric current for entering pin VDD input can become smaller.The adjusting resistance R21 is for adjusting the photoinduction chip 21 to light intensity sense
The sensitivity answered.In this better embodiment, when adjusting resistance R21 is bigger, the photoinduction chip 21 is strong to light
The sensitivity of weak induction is lower；When adjusting resistance R21 is smaller, which incudes light intensity sensitive
It spends higher.
The conversion circuit 30 includes amplifying circuit 31, power supply 33, first resistor R31, second resistance R32.The amplification
Circuit 31 includes input terminal 311 and output end 313.The input terminal 311 connects the second resistance R32 to the power supply 33, defeated
Outlet 313 connect the first resistor R31 to the backlight driving chip 11 feedback pin FB and feedback resistance R 12 it
Between.The driving input pin VDD of the photoinduction chip 21 is coupled between the input terminal 311 and second resistance R32.The amplification
The electric current that circuit 31 is used to be inputted on end 311 is passed through after amplifying by the output end 313 output to first resistor R31.
The first resistor R31 is used to convert the current signal that the amplifying circuit 31 exports to voltage signal to export to the backlight and drive
The feedback pin FB of dynamic chip 11.The second resistance R32 is used to provide for the input terminal 311 of the amplifying circuit 31 suitable
Operating voltage, meanwhile, by adjusting the resistance value size of second resistance R32, the driving of the photoinduction chip 21 can be made defeated
Enter and obtains suitable operating current on pin VDD.
In this better embodiment, the amplifying circuit 31 include PNP type triode Q31, the second divider resistance R33,
Third divider resistance R34 and the second filter capacitor C31.Second electricity of the PNP type triode Q31
Hinder R32；Second divider resistance R33 described in base series is to the power supply 33；Collector is coupled to the second resistance R32.
Described one end third divider resistance R34 be coupled to the second divider resistance R33 and the PNP type triode Q31 base stage it
Between, other end ground connection.The second divider resistance R33 and third divider resistance R34 constitutes bleeder circuit, by the power supply 33
The supply voltage of offer is input to the base stage of PNP type triode Q31 after being divided, PNP type triode is enable to work normally.
In this better embodiment, the number of the second filter capacitor C31 is two.One of them second filter capacitor C31 mono-
End is coupled between the base stage of the PNP type triode and the third divider resistance R34, other end ground connection；Another second
The one end filter capacitor C31 is coupled between the collector and first resistor R31 of the PNP type triode Q31, other end ground connection.
Voltage of described two second filter capacitor C31 respectively on the base stage to PNP type triode Q31 and collector is filtered surely
Pressure.
It is appreciated that the amplifying circuit 31 or operational amplifier.
In this better embodiment, the backlight 200 includes four LED210.Four LED210 successively go here and there
It is coupled between the voltage output pin VOUT of the backlight driving chip 11 and feedback resistance R12.And the sun of four LED210
Pole is coupled to the voltage output pin VOUT of the backlight driving chip 11, and cathode is coupled to feedback resistance R12.
It is appreciated that the number of the LED210 of the backlight 200 can according to need and be increased and decreased, and pass through adjusting
The resistance value of first divider resistance R11, then can make multiple LED210 of the backlight 200 obtain specified driving voltage.
The backlight regulating circuit 100 becomes strong at work, when the photoinduction circuit 20 senses external environment light
When, the electric current flowed through on the driving input pin VDD of the photoinduction chip 21 increases, and the stream due to being provided by the power supply 33
It is certain through the electric current on second resistance R32, therefore the electric current for flowing into the emitter of PNP type triode Q31 can become
It is small, it drives the electric current on the collector of PNP type triode Q31 also to become smaller, passes through the electric current on first resistor R31
Become smaller, it at this time can electricity by the voltage pull-down on first resistor R31, i.e. on the feedback pin FB of the backlight driving chip 11
Pressure drags down, and after which detects that the voltage on feedback pin FB is lower, backlight driving chip 11 then can
Increase the electric current exported on its voltage output pin VOUT, the electric current flowed through on four LED210 at this time becomes larger, thus this four
The brightness of a LED210 can be promoted.
When the photoinduction circuit 20, which senses external environment light, to die down, the driving of the photoinduction chip 21 is inputted
The electric current flowed through on pin VDD reduces, and since the electric current on second resistance R32 that flows through provided by the power supply 33 is one
Fixed, therefore the electric current for flowing into the emitter of PNP type triode Q31 can become larger, and drive the collection of PNP type triode Q31
Electric current on electrode also becomes larger, and the electric current passed through on first resistor R31 becomes larger, at this time can will be on first resistor R31
Voltage high, i.e. voltage high on the feedback pin FB of the backlight driving chip 11, which detects
After voltage on feedback pin FB is got higher, backlight driving chip 11 can then reduce to be exported on its voltage output pin VOUT
Electric current, the electric current flowed through on four LED210 at this time becomes smaller, so that the brightness of four LED210 can reduce, so realizes
Adjusting to display backlight.
The backlight regulating circuit 100 incudes the change of external environment light intensity by the photoinduction chip 21
Change, and the electric signal that the variation of external environment light intensity is converted to variation is input to conversion circuit 30, the conversion circuit
The electric signal for the variation that the photoinduction chip 21 transmits is sent to the backlight driving chip 11 by 30, then by backlight drive core
Piece 11 adjusts the output of its own according to the electric signal of the variation, to realize the adjusting to display backlight.The back
Light adjusts circuit 100 using the electronics such as the photoinduction chip 21, backlight driving chip 11, triode, resistance and capacitor member
Part electric signal itself changes to achieve the purpose that display backlight is adjusted, and circuit is simple and without occupying central processing unit volume
Outer pin.
Claims (10)
1. a kind of backlight regulating circuit, the brightness for the backlight to display is adjusted, the backlight regulating circuit packet
Photoinduction chip and backlight driving chip are included, which is coupled to the backlight, it is characterised in that: the back
It further includes conversion circuit that light, which adjusts circuit, and the conversion circuit is coupled respectively to the photoinduction chip and backlight driving chip, institute
The enhancing or reduction for stating photoinduction chip induction external environment light intensity are converted to increasing or reducing for current signal and are input to
Conversion circuit；Conversion circuit increases or reduces that be converted to being decreased or increased for voltage signal defeated for the current signal received
Out to backlight driving chip, backlight driving chip according to the voltage signal received be decreased or increased it is corresponding adjust output to
The electric current of the backlight is increased or reduced to adjust the luminous brightness of the backlight.
2. backlight regulating circuit as described in claim 1, it is characterised in that: the photoinduction chip includes driving input pin,
The backlight driving chip includes voltage output pin and feedback pin, which is coupled to the voltage output pin, separately
One end is coupled to the feedback pin, and the conversion circuit includes power supply and the first resistor for being coupled to the power supply, first electricity
The other end of resistance is coupled between the feedback pin and backlight of the backlight driving chip, and the driving of the photoinduction chip is defeated
Enter pin to be coupled between the power supply and the first resistor；When external environment light enhances or weakens, the driving input pin
On electric current increase accordingly or reduce, correspondingly reduced or increased by the electric current of the power input to first resistor, this
One resistance is for exporting the variation that the variation of electric current is converted to voltage to the feedback pin, and the backlight driving chip is according to it
The variation of voltage adjusts accordingly the output of electric current on its voltage input pin in feedback pin, to adjust backlight intensity.
3. backlight regulating circuit as claimed in claim 2, it is characterised in that: the conversion circuit further includes amplifying circuit, should
Amplifying circuit includes input terminal and output end, which is coupled to the power supply, and output end end is coupled to first resistor, should
The driving input pin of photoinduction chip is coupled between the power supply and amplifying circuit, which is used for the power supply is defeated
Enter its input terminal electric current amplify after through being exported by output end to the first resistor.
4. backlight regulating circuit as claimed in claim 3, it is characterised in that: the conversion circuit further includes second resistance, should
Second resistance one end is coupled to the power supply, the other end be coupled to the driving input pin and amplify resistance input terminal it
Between, the resistance value of the second resistance is adjusted so as to obtain suitable operating current on the driving input pin.
5. backlight regulating circuit as claimed in claim 4, it is characterised in that: the amplifying circuit includes PNP type triode,
The second resistance of the PNP type triode；Base stage is coupled to the power supply；Collector is coupled to described
First resistor.
6. backlight regulating circuit as claimed in claim 5, it is characterised in that: the amplifying circuit further includes the second partial pressure electricity
Resistance and third divider resistance, second divider resistance are coupled between the power supply and the base stage of the PNP type triode；It should
Third divider resistance one end described in third divider resistance is coupled to the base of second divider resistance and the PNP type triode
Between pole, other end ground connection.
7. such as backlight regulating circuit described in claim 5 or 6, it is characterised in that: the amplifying circuit further includes two second
Filter capacitor, described two second filter capacitors respectively filter the voltage on the base stage of PNP type triode and collector
Wave.
8. backlight regulating circuit as claimed in claim 2, it is characterised in that: the backlight regulating circuit further includes first point
Piezoresistance, the first divider resistance one end are coupled between the backlight and the feedback pin of the backlight driving chip, the other end
Ground connection, which divides the output voltage of the backlight driving chip so that the backlight obtain it is specified
Driving voltage.
9. backlight regulating circuit as claimed in claim 2, it is characterised in that: the backlight regulating circuit further includes feedback electricity
Resistance, the feedback resistance one end are coupled to the feedback pin of the backlight driving chip, the other end be coupled to first divider resistance with
Between backlight.
10. backlight regulating circuit as claimed in claim 2, it is characterised in that: backlight regulating circuit further includes adjusting resistance,
The photoinduction chip includes setting pin, which is coupled to the setting pin, other end ground connection；The adjusting
Resistance is for adjusting the sensitivity that the photoinduction chip incudes light intensity.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910124997.4A CN109637469A (en) | 2019-02-20 | 2019-02-20 | Backlight regulating circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910124997.4A CN109637469A (en) | 2019-02-20 | 2019-02-20 | Backlight regulating circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN109637469A true CN109637469A (en) | 2019-04-16 |
Family
ID=66065550
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910124997.4A Pending CN109637469A (en) | 2019-02-20 | 2019-02-20 | Backlight regulating circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109637469A (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102542995A (en) * | 2010-12-22 | 2012-07-04 | 深圳富泰宏精密工业有限公司 | Backlight regulating circuit |
| CN102963295A (en) * | 2012-11-19 | 2013-03-13 | 奇瑞汽车股份有限公司 | Backlight circuit of automobile combination instrument and backlight automatic adjustment method thereof |
| CN103295537A (en) * | 2013-05-08 | 2013-09-11 | 深圳市华星光电技术有限公司 | LED backlight driving circuit, backlight module and liquid crystal display device |
| CN104952398A (en) * | 2014-03-25 | 2015-09-30 | 深圳市海洋王照明工程有限公司 | LED backlight drive circuit and LCD display |
-
2019
- 2019-02-20 CN CN201910124997.4A patent/CN109637469A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102542995A (en) * | 2010-12-22 | 2012-07-04 | 深圳富泰宏精密工业有限公司 | Backlight regulating circuit |
| CN102963295A (en) * | 2012-11-19 | 2013-03-13 | 奇瑞汽车股份有限公司 | Backlight circuit of automobile combination instrument and backlight automatic adjustment method thereof |
| CN103295537A (en) * | 2013-05-08 | 2013-09-11 | 深圳市华星光电技术有限公司 | LED backlight driving circuit, backlight module and liquid crystal display device |
| CN104952398A (en) * | 2014-03-25 | 2015-09-30 | 深圳市海洋王照明工程有限公司 | LED backlight drive circuit and LCD display |
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Application publication date: 20190416 |
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