CN102750907B - Image processing circuit and light illumination module - Google Patents

Image processing circuit and light illumination module Download PDF

Info

Publication number
CN102750907B
CN102750907B CN201110203501.6A CN201110203501A CN102750907B CN 102750907 B CN102750907 B CN 102750907B CN 201110203501 A CN201110203501 A CN 201110203501A CN 102750907 B CN102750907 B CN 102750907B
Authority
CN
China
Prior art keywords
light emitting
emitting diode
voltage
circuit
driving circuit
Prior art date
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.)
Active
Application number
CN201110203501.6A
Other languages
Chinese (zh)
Other versions
CN102750907A (en
Inventor
刘嘉俊
吴忠文
涂建成
王思婷
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Novatek Microelectronics Corp
Original Assignee
Novatek Microelectronics Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Novatek Microelectronics Corp filed Critical Novatek Microelectronics Corp
Publication of CN102750907A publication Critical patent/CN102750907A/en
Application granted granted Critical
Publication of CN102750907B publication Critical patent/CN102750907B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Landscapes

  • Led Devices (AREA)
  • Control Of Indicators Other Than Cathode Ray Tubes (AREA)
  • Circuit Arrangement For Electric Light Sources In General (AREA)

Abstract

The present invention provides an image processing circuit and a light illumination module. The light illumination module comprises an integrated circuit and a plurality of light emitting diode (LED) strings connected in parallel. The integrated circuit could be the image processing circuit. Each of the LED strings has a plurality of LEDs connected in series. The integrated circuit has a driving circuit coupled to the LED strings. The driving circuit supplies a driving voltage to first ends of the LED strings to drive the LED strings. The driving circuit is also configured to maintain the driving voltage at a voltage value obtained when all of the LED strings are turned on, until all of the LED strings are turned on again. Accordingly, the interference of the LED strings is decreased, and the LED strings operate more stably.

Description

Image-processing circuit and illuminating module
Technical field
The present invention relates to a kind of image-processing circuit and illuminating module, particularly relate to the illuminating module of a kind of image-processing circuit controlling the backlight of liquid crystal display and the backlight that liquid crystal display is provided.
Background technology
More and more general as the application of light emitting source using light emitting diode (Light Emitting Diode, LED), the such as screen backlight module of liquid crystal display, mobile phone, portable computer and personal digital assistant etc.Backlight module is the key part and component of driving light source in display, and it not only determines fiduciary level and the degree of stability of display, also directly has influence on the image display quality of display.
In general, in order to user can be adjusted light-source brightness according to hobby or can save more electric power under the permission of ambient brightness, good dimming function must be had.With the physical characteristics of light emitting diode, by the electric current of light emitting diode and the forward bias voltage drop exponentially relation of light emitting diode, the luminous degree of light emitting diode is then directly proportional to the electric current by itself.In other words, when the electric current passed through is larger, the brightness of lumination of light emitting diode is also thereupon higher.Common dimming mode has simulation dimming mode and digital dimming mode.Simulation dimming mode is the forward current size flowing through light emitting diode by adjustment, reaches brightness change.Digital dimming mode is the control flickered to light emitting diode, and the phenomenon utilizing human eye vision to persist, the work period (Duty Cycle) of flickering via change light emitting diode, the control of the brightness that is averaged.Adopt simulation dimming mode, although realize simple, must external circuit be increased, and add the cost of system.Therefore, current development trend just in a digital manner light modulation be main.
Please refer to Fig. 1, Fig. 1 is a kind of schematic diagram of existing illuminating module 100.Illuminating module 100 can be used for the backlight providing liquid crystal display, and it has scaler 112 and driving circuit 122.Scaler 112 and driving circuit 122 are formed in different integrated circuit (IC) chip respectively, and are respectively set on circuit of the scaler plate 110 and drive circuit board 120.Scaler 112 can receive signal of video signal S iMG, with by signal of video signal S iMGresolution be converted to the second resolution by the first resolution, to produce and to export control signal DIM [1:4] to driving circuit 122.The digital signal that control signal DIM [1:4] is nibble, its each bit is in order to control the light emitting diode string 160 of a correspondence.Each light emitting diode string 160 has multiple light emitting diode 162.
Please refer to Fig. 1 and Fig. 2, Fig. 2 is each bit of Fig. 1 control signal DIM [1:4] and the sequential chart of driving voltage VOUT.Each bit DIM [the 1] ~ DIM [3] of control signal DIM [1:4] is each in order to control unlatching and the closedown of corresponding light emitting diode string 160.Say further, when the value of the arbitrary bit in the middle of bit DIM [1] ~ DIM [3] is " 1 " (noble potential), the light emitting diode string 160 corresponding to it can be unlocked; And the value of arbitrary bit in the middle of bit DIM [1] ~ DIM [3] is when being " 0 " (electronegative potential), the light emitting diode string 160 corresponding to it can be closed.
But, because driving circuit 122 according to the terminal voltage of the second end B of the light emitting diode string 160 be sampled to, can control its driving voltage V oUT, again because the terminal voltage of the second end B can be different because of the On/Off state of each light emitting diode string 160, therefore the terminal voltage of the second end B causing driving circuit 122 each be sampled to is not quite similar, and then causes driving voltage V oUTmagnitude of voltage often change.But, driving voltage V oUTthe result that often changes of magnitude of voltage, make driving voltage V oUTitself become a noise source.In the case, the noise of illuminating module 100 can increase, and the intensity of the light that illuminating module 100 is provided is also unstable.
Summary of the invention
The invention provides a kind of image-processing circuit and illuminating module, it just carries out the sampling action of terminal voltage when all light emitting diode strings are all opened, to reduce the noise of illuminating module, and the luminous intensity of its illuminating module is stablized.
The present invention proposes a kind of illuminating module, and it comprises light emitting diode string and an integrated circuit of multiple parallel connection.Each light emitting diode string comprises the light emitting diode of multiple series connection.Integrated circuit comprises driving circuit.Driving circuit is coupled to above-mentioned multiple light emitting diode strings, in order to supply the first end of driving voltage to above-mentioned multiple light emitting diode strings, to drive above-mentioned multiple light emitting diode strings.Driving circuit in order to maintain the above-mentioned magnitude of voltage of driving voltage when light emitting diode string is all unlocked, until above-mentioned multiple light emitting diode strings are all unlocked once again.
The present invention proposes a kind of image-processing circuit, is suitable for driving multiple light emitting diode string.Image-processing circuit comprises driving circuit.Driving circuit is coupled to above-mentioned multiple light emitting diode strings, in order to supply the first end of driving voltage to above-mentioned multiple light emitting diode strings, to drive above-mentioned multiple light emitting diode strings.Driving circuit in order to maintain the above-mentioned magnitude of voltage of driving voltage when light emitting diode string is all unlocked, until above-mentioned multiple light emitting diode strings are all unlocked once again.
In one embodiment of this invention, above-mentioned integrated circuit also comprises scaler (scaler).Scaler couples driving circuit, in order to process signal of video signal, to produce and to output control signals to driving circuit, and makes driving circuit control the operation of above-mentioned multiple light emitting diode strings according to control signal.
In one embodiment of this invention, above-mentioned scaler is also in order to be converted to the second resolution by the resolution of above-mentioned signal of video signal from the first resolution.
In one embodiment of this invention, above-mentioned scaler comprises register, in order to storage data.Wherein when driving circuit detects that above-mentioned light emitting diode string running is abnormal, the abnormal information of light emitting diode string can be stored to register.
In one embodiment of this invention, when driving circuit detects that above-mentioned light emitting diode string running is abnormal, driving circuit can cut out light emitting diode string, and scaler still continued operation.
In one embodiment of this invention, above-mentioned scaler comprises reference voltage circuit, in order to provide reference voltage to driving circuit, produces driving voltage to make driving circuit according to reference voltage.
In one embodiment of this invention, above-mentioned driving circuit controls the work period (duty cycle) of each light emitting diode string according to control signal.
In one embodiment of this invention, above-mentioned integrated circuit is single chip.
In one embodiment of this invention, above-mentioned driving circuit comprises sample circuit and pulse-width modulation circuit.Sample circuit in order to sample the voltage of the second end of light emitting diode string when light emitting diode string is all unlocked, and produces control voltage according to the voltage sampled.Pulse-width modulation circuit, in order to according to control voltage, controls the magnitude of voltage of driving voltage.
In one embodiment of this invention, above-mentioned illuminating module is for providing the backlight of liquid crystal display.
Based on above-mentioned, the driving circuit of illuminating module of the present invention just carries out the sampling action of terminal voltage when all light emitting diode strings are all opened, and the change of the driving voltage of driving circuit is unlikely become a noise source, therefore the noise of illuminating module can be reduced, and the luminous intensity of its illuminating module is stablized.In addition, scaler and driving circuit can be integrated among one chip, significantly can also promote the application elasticity of light emitting diode, and for the support of picture, can reach better instantaneity and application elasticity.
For above-mentioned feature and advantage of the present invention can be become apparent, special embodiment below, and coordinate accompanying drawing to be described in detail below.
Accompanying drawing explanation
Fig. 1 is a kind of schematic diagram of existing illuminating module.
Fig. 2 is each bit of Fig. 1 control signal and the sequential chart of driving voltage.
Fig. 3 is the schematic diagram of the illuminating module of one embodiment of the invention.
Fig. 4 is each bit of Fig. 3 control signal and the sequential chart of driving voltage.
Fig. 5 is the schematic diagram of the illuminating module of one embodiment of the invention.
Fig. 6 is each bit of Fig. 5 control signal and the sequential chart of driving voltage.
Reference numeral:
100,300,500: illuminating module
110: circuit of the scaler plate
120: drive circuit board
310: circuit board
320,520: integrated circuit
112,330,530: scaler
332: register
334: reference voltage circuit
122,340,540: driving circuit
160,360,560: light emitting diode string
162,362,562: light emitting diode
541: sample circuit
542: multiplexer
544: the first error amplifier
546: sample-and-hold circuit
548: the second error amplifier
550: pulse-width modulation circuit
552: shifter
A: first end
B: the second end
DIM [1:4]: control signal
DIM [1] ~ DIM [4]: bit
D eXT: diode
D1, D2, D3: the time interval
T 1, T 2, T 3: time point
S iMG: signal of video signal
S d: adjustment signal
adjustment signal S dcomplementary signal
SW1: the first switch
SW2: second switch
V iN: input voltage
V rEF: reference voltage
V oUT: driving voltage
V c: control voltage
V s: the first dividing potential drop
V l: the second dividing potential drop
L eXT: inductance
R 1: first electric group
R 2: second electric group
R 3: the 3rd electric group
R 4: the 4th electric group
R cS: electric group
Q1: the first transistor
Q2: transistor seconds
Q3: third transistor
Q4: the four transistor
Q5: the five transistor
UVLO, LX, OCP, PGND, OVS, VFB1, VFB2, VFB3, VFB4: pin position
Embodiment
Please refer to Fig. 3, Fig. 3 is the schematic diagram of the illuminating module 300 of one embodiment of the invention.Illuminating module 300 can be used for the backlight providing liquid crystal display, and it has scaler 330 and driving circuit 340.In the present embodiment, scaler 330 and driving circuit 340 are formed in same integrated circuit 320, and integrated circuit 320 can be single chip, and are arranged on circuit board 310.But the present invention is not as limit.For example, in other embodiments of the present invention, scaler 330 can be separated from integrated circuit 320, and independently operates with driving circuit 340.Again such as, in other embodiments of the present invention, illuminating module can not comprise scaler 330.
Illuminating module 300 separately includes multiple light emitting diode string 360, and each light emitting diode string 360 has multiple light emitting diode 362.In the present embodiment, illuminating module 300 has four light emitting diode strings 360, but the present invention is not as limit, those skilled in the art should understand that the number of the light emitting diode string of illuminating module of the present invention can be the number that other are greater than 1.
In the present embodiment, scaler 330 couples driving circuit 340, in order to process signal of video signal S iMG, to produce and to export control signal DIM [1:4] to driving circuit 340, and make driving circuit 340 control the operation of above-mentioned multiple light emitting diode string 360 according to control signal DIM [1:4].In addition, scaler 330 also can in order to by signal of video signal S iMGresolution be converted to the second resolution by the first resolution.In the present embodiment, the digital signal that control signal DIM [1:4] is nibble, its each bit is in order to control the operation of the light emitting diode string 360 of a correspondence.Each light emitting diode string 360 has multiple light emitting diode 362.Must understand, in the present embodiment, the bit number of the control signal DIM [1:4] that scaler 330 produces equals the number of light emitting diode string 360.And in the embodiment of other illuminating module of the present invention, the received number equaling light emitting diode string in order to its bit number of control signal controlling the operation of light emitting diode string of driver.
Driving circuit 340 is coupled to above-mentioned multiple light emitting diode strings 360, in order to supply driving voltage V oUTto the first end A of light emitting diode string 360, to drive light emitting diode string 360.Please refer to Fig. 3 and Fig. 4, Fig. 4 is each bit and the driving voltage V of Fig. 3 control signal DIM [1:4] oUTsequential chart.Each bit DIM [the 1] ~ DIM [3] of control signal DIM [1:4] is each in order to control unlatching and the closedown of corresponding light emitting diode string 360.Say further, when the value of the arbitrary bit in the middle of bit DIM [1] ~ DIM [3] is " 1 " (noble potential), the light emitting diode string 360 corresponding to it can be unlocked; And the value of arbitrary bit in the middle of bit DIM [1] ~ DIM [3] is when being " 0 " (electronegative potential), the light emitting diode string 360 corresponding to it can be closed.Therefore, driving circuit 340 can control the work period (duty cycle) of each light emitting diode string 360 according to control signal DIM [1:4].
Driving circuit 340 can maintain driving voltage V oUTmagnitude of voltage when all light emitting diode strings 360 are all unlocked, until all light emitting diode strings 360 are all unlocked once again.For Fig. 4, driving circuit 340 can maintain driving voltage V in the time interval D1, D2 and D3 oUTmagnitude of voltage, and driving voltage V oUTthe magnitude of voltage maintained in the time interval D1, D2 and D3 equals driving voltage V oUTat time point T 1, T 2and T 3magnitude of voltage, and whole light emitting diode strings 360 is at time point T 1, T 2and T 3can all be unlocked.
Thus, driving circuit 340 is supplied to the driving voltage V of light emitting diode string 360 oUTcan remain unchanged for a long time, therefore be unlikely to other circuit of formation one noise source interference, also can not cause the change of the current spikes of light emitting diode string 360.
Refer again to Fig. 3, in an alternative embodiment of the invention, scaler 330 can comprise register 332, in order to storage data.Wherein when driving circuit 340 detects that light emitting diode string 360 operates abnormal, the abnormal information of light emitting diode string 360 can be stored to register 332.In addition, in an embodiment of the present invention, when driving circuit 340 detects that light emitting diode string 360 operates abnormal, driving circuit 340 can cut out light emitting diode string 360, and scaler 330 still continued operation now.Thus, when light emitting diode string 360 operates abnormal, light emitting diode string 360 can be closed in time, and the abnormal information be stored in register 332 then can be read out, as the foundation of follow-up debug or maintenance.
In an embodiment of the present invention, scaler 330 can comprise reference voltage circuit 334.Reference voltage circuit 334 is in order to provide reference voltage V rEFto driving circuit 340, to make driving circuit 340 according to reference voltage V rEFproduce driving voltage V oUT.In this embodiment, in response to different demands, the reference voltage V that reference voltage circuit 334 provides rEFmagnitude of voltage can be adjusted.For example, in response to the light emitting diode string 360 of different number, reference voltage circuit 334 can provide the reference voltage V of tool appropriate voltage value rEFto driving circuit 340, suited the requirements to make the luminous intensity of light emitting diode string 360.
Please refer to Fig. 5, Fig. 5 is the schematic diagram of the illuminating module 500 of one embodiment of the invention.Similar to above-mentioned illuminating module 300, illuminating module 500 also can be used for the backlight providing liquid crystal display, and it has scaler 530 and driving circuit 540.In the present embodiment, scaler 530 and driving circuit 540 are formed in same integrated circuit 540, and integrated circuit 540 can be single chip.But the present invention is not as limit.For example, in other embodiments of the present invention, scaler 530 can be separated from integrated circuit 520, and independently operates with driving circuit 540.Again such as, in other embodiments of the present invention, illuminating module can not comprise scaler 530.
Illuminating module 500 separately includes multiple light emitting diode string 560, and each light emitting diode string 560 has multiple light emitting diode 562.In the present embodiment, illuminating module 500 has four light emitting diode strings 560, but the present invention is not as limit, those skilled in the art should understand the number of the light emitting diode string of illuminating module of the present invention can be more than or equal to 2 other numbers.
In the present embodiment, scaler 530 couples driving circuit 540, in order to process signal of video signal S iMG, to produce and to export control signal DIM [1:4] to driving circuit 540, and make driving circuit 540 control the operation of above-mentioned multiple light emitting diode string 560 according to control signal DIM [1:4].In addition, scaler 530 also can in order to by signal of video signal S iMGresolution be converted to the second resolution by the first resolution.In the present embodiment, the digital signal that control signal DIM [1:4] is nibble, its each bit is in order to control the light emitting diode string 560 of a correspondence.Each light emitting diode string 560 has multiple light emitting diode 562.In the present embodiment, the bit number of control signal DIM [1:4] that scaler 530 produces equals the number of light emitting diode string 560.
Driving circuit 540 is coupled to above-mentioned multiple light emitting diode strings 560, in order to supply driving voltage V oUTto the first end A of light emitting diode string 560, to drive light emitting diode string 560.Please refer to Fig. 5 and Fig. 6, Fig. 6 is each bit and the driving voltage V of Fig. 5 control signal DIM [1:4] oUTsequential chart.Each bit DIM [the 1] ~ DIM [3] of control signal DIM [1:4] is each in order to control unlatching and the closedown of corresponding light emitting diode string 560.Say further, when the value of the arbitrary bit in the middle of bit DIM [1] ~ DIM [3] is " 1 " (noble potential), the light emitting diode string 560 corresponding to it can be unlocked; And the value of arbitrary bit in the middle of bit DIM [1] ~ DIM [3] is when being " 0 " (electronegative potential), the light emitting diode string 560 corresponding to it can be closed.Therefore, driving circuit 560 can control the work period of each light emitting diode string 560 according to control signal DIM [1:4].
Driving circuit 540 can maintain driving voltage V oUTmagnitude of voltage when all light emitting diode strings 560 are all unlocked, until all light emitting diode strings 560 are all unlocked once again.For Fig. 6, driving circuit 540 can maintain driving voltage V in the time interval D1, D2 and D3 oUTmagnitude of voltage, and driving voltage V oUTthe magnitude of voltage maintained in the time interval D1, D2 and D3 equals driving voltage V oUTat time point T 1, T 2and T 3magnitude of voltage, and whole light emitting diode strings 560 is at time point T 1, T 2and T 3can all be unlocked.
Thus, driving circuit 540 is supplied to the driving voltage V of light emitting diode string 560 oUTcan remain unchanged for a long time, therefore be unlikely to other circuit of formation one noise source interference, also can not cause the change of the current spikes of light emitting diode string 560.
In an embodiment of the present invention, driving circuit 540 can comprise sample circuit 541 and width modulation (Pulse Width Modulation; PWM) circuit 550.Sample circuit 541 in order to sample the voltage of its second end B when above-mentioned light emitting diode string 560 is all unlocked, and produces control voltage V according to the voltage sampled c.Pulse-width modulation circuit 550 is in order to foundation control voltage V c, control driving voltage V oUTmagnitude of voltage.
In an embodiment of the present invention, driving circuit 540 also can comprise the first transistor Q1, transistor seconds Q2, third transistor Q3, the 4th transistor Q4, its grid is controlled by a bit of control signal DIM [1:4] respectively, and its drain electrode is connected to the second end B of corresponding light emitting diode string 560 respectively by pin VFB1, VFB2, VFB3 and VFB4.Sample circuit 541 also comprises multiplexer 542, first error amplifier 544, sample-and-hold circuit 546 and the second error amplifier 548.Multiplexer 542 can be selected and export the minimum voltage in the voltage of the second end B of each light emitting diode string 560.First error amplifier 544 can according to reference voltage V rEFand the voltage that multiplexer 542 exports, export corresponding voltage.Sample-and-hold circuit 546 is controlled by adjustment signal S d.As adjustment signal S dwhen noble potential, sample-and-hold circuit 546 can sample the first dividing potential drop V s; And as adjustment signal S dwhen electronegative potential, sample-and-hold circuit 546 can keep the first sampled dividing potential drop V s.The first dividing potential drop V that second error amplifier 548 can sample according to sample-and-hold circuit 546 sthe first dividing potential drop V at that time sexport corresponding voltage.Sample circuit 541 also can comprise the first interrupteur SW 1 and second switch SW2, and wherein the first interrupteur SW 1 is coupled to the output terminal of the first error amplifier 544 and is controlled by adjustment signal S d, and second switch SW2 is coupled to the output terminal of the second error amplifier 548 and is controlled by signal wherein signal for adjustment signal S dcomplementary signal.The framework of above, sample circuit 541 exports control voltage V cto pulse-width modulation circuit 550, and make pulse-width modulation circuit 550 according to control voltage V ccontrol driving voltage V oUTmagnitude of voltage.
In an embodiment of the present invention, illuminating module 500 separately can comprise the first resistance R of series connection 1and the second resistance R 2, in order to by input voltage V iNdividing potential drop, and produce and export the second dividing potential drop V lto the pin UVLO of driving circuit 540.Wherein, input voltage V iNfor DC voltage.In addition, illuminating module 500 also can comprise inductance L eXTand diode D eXT.Inductance L eXTin order to input voltage V iNcarry out direct current conversion, and diode D eXTthen in order to rectification.Illuminating module 500 also can comprise the 5th transistor Q5 and shifter 552.Shifter 552 is coupled to pulse-width modulation circuit 550 by pin LX, and the position of the voltage exported in order to the above-mentioned pulse-width modulation circuit 550 of displacement is accurate.5th transistor Q5 then can accurate and conducting or not conducting according to the output voltage position of shifter 552, and then the voltage of the drain electrode of the 5th transistor Q5 can be adjusted because of the change of the output voltage of pulse-width modulation circuit 550.Illuminating module 500 also can comprise resistance R cS, its one end is coupled to the source electrode of the 5th transistor Q5 and the pin OCP of driving circuit 540, and its other end is coupled to the pin PGND of driving circuit 540.Driving circuit 540 can according to the current potential of pin OCP, PGND and resistance R cSresistance value, judge the size of the electric current flowing through the 5th transistor Q5.Illuminating module 500 also can comprise the 3rd resistance R of series connection 3and the 4th resistance R 4, in order to by driving voltage V oUTdividing potential drop, and produce and export the first dividing potential drop V sto the pin OVS of driving circuit 540.By this, driving circuit 540 can according to the first dividing potential drop V sand the second dividing potential drop V l, judge input voltage V iNand driving voltage V oUTmagnitude of voltage.
In other embodiments of the present invention, also provide for the image-processing circuit being suitable for driving above-mentioned multiple light emitting diode string 360 or 560.Above-mentioned image-processing circuit can be the integrated circuit 320 of Fig. 3, or be the integrated circuit 520 of Fig. 5, and the sampling action of terminal voltage just can be carried out when all light emitting diode strings 360 or 560 are all opened, to reduce the noise of illuminating module, and the luminous intensity of its illuminating module is stablized.Thin portion as image-processing circuit illustrates, can refer to the above-mentioned explanation for integrated circuit 320,520, namely repeats no more at this.
In sum, the driving circuit of illuminating module of the present invention just carries out the sampling action of terminal voltage when all light emitting diode strings are all opened, and the change of the driving voltage of driving circuit is unlikely become a noise source, therefore the noise of illuminating module can be reduced, and the luminous intensity of its illuminating module is stablized.In addition, scaler and driving circuit can be integrated among one chip, significantly can also promote the application elasticity of light emitting diode, and for the support of picture, can reach better instantaneity and application elasticity.
Although the present invention with embodiment disclose as above, so itself and be not used to limit the present invention, any person of an ordinary skill in the technical field, when doing a little change and retouching, and does not depart from the spirit and scope of the present invention.

Claims (13)

1. an illuminating module, comprising:
The light emitting diode string of multiple parallel connection, each light emitting diode string comprises the light emitting diode of multiple series connection; And
One integrated circuit, comprising:
One drive circuit, be coupled to those light emitting diode strings, in order to supply the first end of a driving voltage to those light emitting diode strings, to drive those light emitting diode strings, this driving circuit in order to maintain the magnitude of voltage of this driving voltage when those light emitting diode strings are all unlocked, until those light emitting diode strings are all unlocked once again, wherein this driving circuit more comprises a sample circuit and a pulse-width modulation circuit, this sample circuit samples the voltage of the second end of those light emitting diode strings when those light emitting diode strings are all unlocked, and produce a control voltage according to the voltage sampled, and this pulse-width modulation circuit is in order to according to this control voltage, controls the magnitude of voltage of this driving voltage.
2. illuminating module according to claim 1, wherein this integrated circuit also comprises:
One scaler, couples this driving circuit, in order to process a signal of video signal, controls signal to this driving circuit, and make this driving circuit control the operation of those light emitting diode strings according to this control signal to produce and to export one.
3. illuminating module according to claim 2, wherein this scaler is also in order to be converted to one second resolution by the resolution of this signal of video signal from one first resolution.
4. illuminating module according to claim 2, wherein this scaler comprises:
One register, in order to storage data;
Wherein when this driving circuit detects that the running of those light emitting diode strings is abnormal, the abnormal information of those light emitting diode strings can be stored to this register.
5. illuminating module according to claim 2, wherein when this driving circuit detects that the running of those light emitting diode strings is abnormal, this driving circuit can cut out those light emitting diode strings, and this scaler still continued operation.
6. illuminating module according to claim 2, wherein this scaler comprises:
One reference voltage circuit, in order to provide a reference voltage to this driving circuit, produces this driving voltage to make this driving circuit according to this reference voltage.
7. illuminating module according to claim 2, wherein this driving circuit controls the work period of each those light emitting diode string according to this control signal.
8. illuminating module according to claim 2, wherein this integrated circuit is single chip.
9. illuminating module according to claim 1, wherein this illuminating module is for providing the backlight of a liquid crystal display.
10. an image-processing circuit, be suitable for driving multiple light emitting diode string, this image-processing circuit comprises:
One drive circuit, be coupled to those light emitting diode strings, in order to supply the first end of a driving voltage to those light emitting diode strings, to drive those light emitting diode strings, this driving circuit in order to maintain the magnitude of voltage of this driving voltage when those light emitting diode strings are all unlocked, until those light emitting diode strings are all unlocked once again, wherein this driving circuit more comprises:
One sample circuit, in order to sample the voltage of the second end of those light emitting diode strings when those light emitting diode strings are all unlocked, and produces a control voltage according to the voltage sampled; And
One pulse-width modulation circuit, in order to according to this control voltage, controls the magnitude of voltage of this driving voltage.
11. image-processing circuits according to claim 10, wherein this image-processing circuit also comprises:
One scaler, couples this driving circuit, in order to process a signal of video signal, controls signal to this driving circuit, and make this driving circuit control the operation of those light emitting diode strings according to this control signal to produce and to export one.
12. image-processing circuits according to claim 11, wherein this scaler is also in order to be converted to one second resolution by the resolution of this signal of video signal from one first resolution.
13. image-processing circuits according to claim 11, wherein this scaler comprises:
One register, in order to storage data;
Wherein when this driving circuit detects that the running of those light emitting diode strings is abnormal, the abnormal information of those light emitting diode strings can be stored to this register.
CN201110203501.6A 2011-04-22 2011-07-20 Image processing circuit and light illumination module Active CN102750907B (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US201161478063P 2011-04-22 2011-04-22
US61/478,063 2011-04-22

Publications (2)

Publication Number Publication Date
CN102750907A CN102750907A (en) 2012-10-24
CN102750907B true CN102750907B (en) 2015-01-14

Family

ID=47031041

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201110203501.6A Active CN102750907B (en) 2011-04-22 2011-07-20 Image processing circuit and light illumination module

Country Status (2)

Country Link
CN (1) CN102750907B (en)
TW (1) TWI431599B (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112423452B (en) * 2019-08-19 2023-03-28 光宝电子(广州)有限公司 Street lamp control device and street lamp control method
TWI768667B (en) 2021-01-20 2022-06-21 緯創資通股份有限公司 Direct-lit led backlight display and light emission control method thereof

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
TW201023682A (en) * 2008-12-12 2010-06-16 Chunghwa Picture Tubes Ltd Current-balance circuit and backlight module having the same
CN102573192A (en) * 2010-12-16 2012-07-11 联咏科技股份有限公司 Protection device of driving voltage of light-emitting diode and driving device

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4985669B2 (en) * 2009-02-05 2012-07-25 株式会社デンソー Light emitting diode drive circuit
US8217591B2 (en) * 2009-05-28 2012-07-10 Cree, Inc. Power source sensing dimming circuits and methods of operating same

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
TW201023682A (en) * 2008-12-12 2010-06-16 Chunghwa Picture Tubes Ltd Current-balance circuit and backlight module having the same
CN102573192A (en) * 2010-12-16 2012-07-11 联咏科技股份有限公司 Protection device of driving voltage of light-emitting diode and driving device

Also Published As

Publication number Publication date
CN102750907A (en) 2012-10-24
TW201243809A (en) 2012-11-01
TWI431599B (en) 2014-03-21

Similar Documents

Publication Publication Date Title
TWI404310B (en) Power management and control module and liquid crystal display device
KR100945205B1 (en) Light emitting element drive device and mobile device using the same
KR101539359B1 (en) Method for driving a light source, light source apparatus for performing the method, and display apparatus having the light source apparatus
US7714517B2 (en) LED driver with current sink control and applications of the same
KR101912936B1 (en) Apparatus for controlling constant current for multi-channel led and liquid crystal display using the same
CN102237040B (en) Driving circuit of light emitting diode, light emitting apparatus, electronic apparatus
JP4950631B2 (en) Method and apparatus for supplying power to a light emitting diode array
KR100587022B1 (en) Led driving circuit comprising dimming circuit
EP2360990B1 (en) Backlight assembly and display apparatus having the same
US7557520B2 (en) Light source driving circuit
US8994279B2 (en) Method and apparatus to control a DC-DC converter
CN103037597B (en) Multi-channel LED (Light Emitting Diode) constant current control circuit and LED light source control system
US9439259B2 (en) LED backlight driving circuit for LCD panels
US8502459B2 (en) Driver IC for electrical load and driving method thereof
US9105219B2 (en) Light emitting element drive device, light emitting element drive method, and display apparatus
CN101176215A (en) Drive circuit for supplying, based on control signal, current to load, and mobile information terminal incorporating the same
US20140097762A1 (en) Light emitting element drive circuit
JP2004022646A (en) Led driving circuit
JP4094018B2 (en) Portable device
CN102750907B (en) Image processing circuit and light illumination module
US8664868B2 (en) Image processing circuit and light illumination module
CN102542997A (en) Systems and methods for dynamic power management for use with a video display device
CN115035867B (en) Backlight driving circuit and method, backlight module and display device
CN116056283A (en) Multichannel low-voltage linear constant current driving LED lighting control circuit with network communication
KR100664001B1 (en) Lighting apparatus formed by serially-driven lighting units

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C14 Grant of patent or utility model
GR01 Patent grant