CN106409241B - The short-circuit protection method of liquid crystal display device and multi partition LED backlight - Google Patents
The short-circuit protection method of liquid crystal display device and multi partition LED backlight Download PDFInfo
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- CN106409241B CN106409241B CN201611076228.4A CN201611076228A CN106409241B CN 106409241 B CN106409241 B CN 106409241B CN 201611076228 A CN201611076228 A CN 201611076228A CN 106409241 B CN106409241 B CN 106409241B
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- 238000000034 method Methods 0.000 title claims abstract description 34
- 238000005192 partition Methods 0.000 title claims abstract description 31
- 239000004973 liquid crystal related substance Substances 0.000 title claims abstract description 29
- 239000004065 semiconductor Substances 0.000 claims abstract description 51
- 238000005070 sampling Methods 0.000 claims description 13
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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
- G09G3/342—Control of illumination source using several illumination sources separately controlled corresponding to different display panel areas, e.g. along one dimension such as lines
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Abstract
A kind of short-circuit protection method of liquid crystal display device and multi partition LED backlight; including making each driving unit can be according to certain time interval, certain voltage step-length; to attempt to improve driving current; PWM duty cycle is reduced simultaneously; driving current and the product of PWM duty cycle are reached and maintained to stablize in setting value, starts and enters backlight course of normal operation with terminate to light backlight;Backlight process is being lighted, if the difference of the driving voltage of any two paths of LED lamp bar is more than the protection voltage threshold value of setting, is determining that short circuit occurs in the lower LED light bar of driving voltage value, and then the paths of LEDs lamp bar can be disconnected by the first metal-oxide-semiconductor of shutdown;In backlight course of normal operation, if driving current reaches the current protection point of setting, determine that short circuit occurs in the paths of LEDs lamp bar, and then the paths of LEDs lamp bar can be disconnected by the first metal-oxide-semiconductor of shutdown.The present invention can effectively improve the safety of liquid crystal display device.
Description
Technical field
The present invention relates to liquid crystal display device more particularly to the multi partition backlight driving systems of liquid crystal display device.
Background technique
Currently, the backlight of liquid crystal display panel is almost LED backlight entirely in television field.It is high in order to improve display effect
TV is held, such as: multi partition LED backlight is usually used in ULED TV, and each subregion LED backlight can be according to display picture
Gray scale adjustment carrys out backlight illumination.Since multi partition LED backlight is needed using more LED light bars, lamp bar line number amount and LED driving number
Amount is consequently increased;In this way, be easy in process of production, by squeezing line, connecting the problems such as weldering and component failure, to lead to LED
The probability of happening of short circuit can be greatly increased compared to common LED backlight TV.Therefore, it is really necessary to the more of ULED TV
Subregion LED backlight technology improves, and is the more perfect fail-safe design of multi partition LED backlight drive system, so as to
While promoting effect, the generation of safety problem can be effectively prevented from.
Summary of the invention
The technical problem to be solved in the present invention is that overcoming above-mentioned the shortcomings of the prior art, and propose a kind of multi partition
The short-circuit protection method of LED backlight can effectively improve the safety of liquid crystal display device.
The technical solution that the present invention proposes in view of the above technical problems includes propose a kind of multi partition LED backlight short
Road guard method, comprising:
Making multi partition backlight driving system includes: LED drive power;LED multi-path lamp bar, the anode of each paths of LEDs lamp bar is simultaneously
The driving voltage of LED drive power offer is provided;Microprocessor, including multiple driving units, each driving unit is for controlling
The driving current of corresponding LED light bar all the way;First metal-oxide-semiconductor is connected with corresponding LED light bar, and it is single to be controlled by corresponding driving
Member and closure/disconnection;Current sampling resistor is supplied to the driving unit for sampling the driving current of corresponding LED light bar;
Make each driving unit can be according to certain time interval, certain voltage step-length, to attempt to improve driving current, simultaneously
PWM duty cycle is reduced, driving current and the product of PWM duty cycle are reached and is maintained to stablize in setting value, to terminate
That lights backlight starts and enters backlight course of normal operation;
Backlight process is being lighted, if the difference of the driving voltage of any two paths of LED lamp bar is more than the protection voltage of setting
Threshold value then determines that short circuit occurs in the lower LED light bar of driving voltage value, and then can disconnect this by the first metal-oxide-semiconductor of shutdown
Paths of LEDs lamp bar;
In backlight course of normal operation, if the driving current of certain paths of LEDs lamp bar reaches the current protection point of setting, sentence
There is short circuit in the fixed paths of LEDs lamp bar, and then can disconnect the paths of LEDs lamp bar by the first metal-oxide-semiconductor of shutdown.
The technical solution that the present invention proposes in view of the above technical problems further includes proposing a kind of liquid crystal display device, packet
Liquid crystal display panel and multi partition backlight driving system are included, which includes: LED drive power;Multi-way LED lamp
Item, the anode of each paths of LEDs lamp bar and the driving voltage that LED drive power offer is provided;Microprocessor, including multiple drivings are single
Member, each driving unit are used to control the driving current of corresponding LED light bar all the way;First metal-oxide-semiconductor, with corresponding LED light bar
It is connected, is controlled by corresponding driving unit and is closed/disconnects;Current sampling resistor, for sampling the driving of corresponding LED light bar
Electric current is supplied to the driving unit;
Wherein, each driving unit can according to certain time interval, certain voltage step-length, to attempt to improve driving current,
PWM duty cycle is reduced simultaneously, driving current and the product of PWM duty cycle are reached and is maintained to stablize in setting value, with
Terminate to light backlight starts and enters backlight course of normal operation;
Backlight process is being lighted, if the difference of the driving voltage of any two paths of LED lamp bar is more than the protection voltage of setting
Threshold value then determines that short circuit occurs in the lower LED light bar of driving voltage value, and then can disconnect this by the first metal-oxide-semiconductor of shutdown
Paths of LEDs lamp bar;
In backlight course of normal operation, if the driving current of certain paths of LEDs lamp bar reaches the current protection point of setting, sentence
There is short circuit in the fixed paths of LEDs lamp bar, and then can disconnect the paths of LEDs lamp bar by the first metal-oxide-semiconductor of shutdown.
Compared with prior art, by the present invention in that each driving unit can be walked according to certain time interval, certain voltage
It is long, to attempt to improve driving current, while PWM duty cycle is reduced, the product of driving current and PWM duty cycle is reached
And maintain to stablize in setting value, it is more than the protection voltage threshold value of setting in the difference of the driving voltage of any two paths of LED lamp bar
When, it is possible to determine that there is short circuit lighting backlight process, when driving current reaches the current protection point of setting, it is possible to determine that
There is short circuit in backlight course of normal operation, and then can disconnect short circuit by the first metal-oxide-semiconductor of shutdown when determining that short circuit occurs
LED light bar, the safety of liquid crystal display device can be effectively improved.
Detailed description of the invention
Fig. 1 is the functional block diagram of multi partition backlight driving system in liquid crystal display device of the invention.
Fig. 2 is the flow chart of the short-circuit protection method of multi partition LED backlight of the invention.
Fig. 3 is the flow chart of present invention short-circuit protection method of LED light bar during lighting backlight.
Fig. 4 is the flow chart of present invention short-circuit protection method of LED light bar in backlight course of normal operation.
Fig. 5 is the electrical schematic diagram of multi partition backlight driving system in liquid crystal display device of the invention.
Fig. 6 is the electrical schematic diagram of single led lamp bar driving in liquid crystal display device of the invention.
Fig. 7 is the triggering waveform diagram of present invention short-circuit protection of LED light bar in backlight course of normal operation.
Wherein, the reference numerals are as follows: 100 multi partition backlight driving system, 101 microprocessor, 102 LD interface
103 LED multi-path driving chip, 104 single LED drives 105 LED light bar of output unit, 106 voltage and current detection circuit;
503 506 current sampling resistor of LED multi-path driving chip 504 first metal-oxide-semiconductor, 505 LED light bar, 508 LED driving electricity
Source;5031 second metal-oxide-semiconductor, 5032 operational amplifier;The short-circuit trigger process 703 of 701 normal operating condition 702 is set
Current protection value.
Specific embodiment
Below in conjunction with attached drawing, the present invention is further described in detail.
It is the functional block diagram of multi partition backlight driving system in liquid crystal display device of the invention referring to Fig. 1, Fig. 1.This hair
Bright to propose a kind of liquid crystal display device, which can be liquid crystal display, be also possible to LCD TV.The liquid crystal display
Device includes liquid crystal display panel and provides the multi partition backlight driving system 100 of backlight for the liquid crystal display panel.The multi partition backlight
Drive system 100 includes: microprocessor 101, the adjustment of LD(LOCAL DIMMING dynamic area backlight) interface 102, LED multi-path
Driving chip 103, single LED drive output unit 104, LED light bar 105 and voltage and current detection circuit 106.
Referring to fig. 2, Fig. 2 is the flow chart of the short-circuit protection method of multi partition LED backlight of the invention.Multi partition LED back
The short-circuit protection method of light the following steps are included:
S201, make each driving unit can be according to certain time interval, certain voltage step-length, to attempt to improve driving electricity
Stream, while PWM (Pulse-width modulation, pulse width modulation) duty ratio is reduced, so that driving current and PWM
The product of duty ratio can reach and maintain to stablize in setting value, be worked normally with terminating to light the backlight that starts and enters of backlight
Process;
S202, backlight process is being lighted, if the difference of the driving voltage of any two paths of LED lamp bar is more than the protection of setting
Voltage threshold value then determines that short circuit occurs in the lower LED light bar of driving voltage value, and then can be broken by the first metal-oxide-semiconductor of shutdown
Open the paths of LEDs lamp bar;And
S203, in backlight course of normal operation, if the driving current of certain paths of LEDs lamp bar reaches the current protection of setting
Point then determines that short circuit occurs in the paths of LEDs lamp bar, and then can disconnect the paths of LEDs lamp bar by the first metal-oxide-semiconductor of shutdown.
It is noted that above-mentioned lighting backlight process and setting in two kinds of short-circuit protections of backlight course of normal operation
Meter both can be protected in time in LED light bar when most lamp short circuits or even when LED light bar is positive and negative short-circuit, and prevent the big electricity of high pressure
Stream impact burn out device, cause it is on fire;Can also in LED light bar a small number of lamps or even when a lamp short circuit, disconnect lamp bar, prevent
Only lamp bar for a long time generate heat, cause it is on fire.
It is the flow chart of present invention short-circuit protection method of LED light bar during lighting backlight referring to Fig. 3, Fig. 3.Point
During bright backlight LED light bar short-circuit protection method the following steps are included:
S301, LED drive circuit starting allow each paths of LEDs lamp bar to be connected with minimum duty cycle;
S302, the conducting electric current for judging whether there is certain paths of LEDs lamp bar are more than the protective current value of setting, if being, are turned
Step S308, otherwise, go to step S303;
S303, it is stepped up driving voltage, each paths of LEDs lamp bar can successively reach setting electric current value according to pressure drop height;
S304, it records each paths of LEDs lamp and reaches corresponding driving voltage value when setting electric current value;
S305, judge whether any two paths of LED lamp bar and the difference of when setting electric current value corresponding driving voltage value be more than
The short-circuit protection voltage threshold value of setting, if being, goes to step S307, otherwise, go to step S306;
S306, starting terminate, into normal operating conditions;
When S307, judgement are with setting electric current value there is short circuit in the corresponding lower LED light bar of driving voltage value, go to step
S309;
S308, determine that conducting electric current is more than that the LED light bar of the protective current value of setting has short circuit, go to step S309;
S309, the LED light bar for disconnecting short circuit.
Referring to fig. 4, Fig. 4 is the flow chart of present invention short-circuit protection method of LED light bar in backlight course of normal operation.
In backlight course of normal operation LED light bar short-circuit protection method the following steps are included:
If short circuit occur in S401, certain paths of LEDs lamp bar, pressure drop can be reduced;
S402, this street lamp item LED drive unit improve driving voltage to promote the conducting electric current of lamp bar, while reducing and leading
Logical duty ratio;
S403, the conducting electric current for judging whether this paths of LEDs lamp bar are more than the protective current value of setting, if being, are gone to step
S404, otherwise, go to step S402;
S404, determine that this paths of LEDs lamp bar has short circuit;
S405, the LED light bar for disconnecting short circuit.
It is the electrical schematic diagram of multi partition backlight driving system in liquid crystal display device of the invention referring to Fig. 5, Fig. 5.This is more
Subregion backlight driving system 500 includes: LED multi-path driving chip 503, the first metal-oxide-semiconductor 504, LED light bar 505, current sample electricity
Resistance 506 and LED drive power 508.
It is understood that the LED multi-path driving chip 503 is microprocessor.The LED multi-path driving chip 503 includes
Multichannel driving unit can carry out drive control to LED multi-path lamp bar 505.In the present embodiment, the LED multi-path driving chip
503 being capable of 16 paths of LEDs lamp bar 505 of drive control.In other embodiments, which can apply
In the LED backlight application of any 505 quantity of LED light bar, the quantity for LED light bar 505 is more than the application scenarios on 16 tunnels, both may be used
To select the stronger LED multi-path driving chip 503 of processing capacity, multiple LED multi-path driving chips 503 also can be used.
The LED drive power 508 can be randomly topologically structured DC-DC conversion circuit or AC-DC translation circuit, use
In the driving voltage VLED according to input voltage VIN, provided.The LED drive power 508 can feed back to driving voltage VLED
To the port FB1 of the LED multi-path driving chip 503.Specifically, driving voltage VLED is via resistance Rfb1 and resistance Efb2
Partial pressure, using resistance Rfb3 be sent into port FB1.
In conjunction with the electrical schematic diagram for referring to Fig. 6, Fig. 6 being single led lamp bar driving in liquid crystal display device of the invention.Individually
LED light bar driving includes: driving unit 5030, the first metal-oxide-semiconductor 504, LED light bar 505 and current sampling resistor 506.
The driving unit 5030 is equivalent to 503 corresponding ports G of LED multi-path driving chip and a port S in Fig. 5
Between equivalent circuit.In the present embodiment, which includes second metal-oxide-semiconductor 5031 and an operation amplifier
Device 5032.First metal-oxide-semiconductor 504 and the second metal-oxide-semiconductor 5031 are two metal-oxide-semiconductors being serially connected, and the first metal-oxide-semiconductor 504 works in out
Off status controls on-off according to PWM, and the second metal-oxide-semiconductor 5031 works in linear condition, is controlled work by operational amplifier 5032 and existed
Linear zone.
It, the characteristics of drain current (i.e. LED current) Id is driven voltage Vgs control, can be with when using metal-oxide-semiconductor linear condition
The electric current of LED light bar 505 is controlled by the second metal-oxide-semiconductor 5031.Wherein, the anode of LED multi-path lamp bar 505 is to be connected in parallel on one
It rises, the driving voltage VLED provided with LED drive power is connected, the cathode of each paths of LEDs lamp bar 505 and corresponding first metal-oxide-semiconductor
504 drain electrode is connected.In the ideal situation, each paths of LEDs lamp bar 505 is not no pressure difference, and each paths of LEDs lamp bar 505 is in same electricity
Required driving voltage is the same in the case where stream.
The principle for the LED short-circuit protection that the multi partition backlight driving system 500 is realized during lighting backlight is substantially are as follows:
During lighting backlight, the first metal-oxide-semiconductor 504 first is controlled with minimum duty cycle, each paths of LEDs lamp bar 505 is allowed to be connected,
Each 505 electric current of paths of LEDs lamp bar is detected by current sampling resistor 506, if electric current is more than design protection point current value, is judged
There is short circuit in LED light bar 505, and driving unit 5030 stops starting, device failure caused by preventing because of short circuit, fever, on fire.If
505 electric current of LED light bar is normal, not trigger protection, and driving unit 5030 continues to start, the drive of lifting step by step LED drive power 508
Dynamic voltage VLED, in driving voltage VLED from initial voltage by step uphill process, each paths of LEDs lamp bar 505 can be according to pressure drop height
It is low successively to reach setting electric current value, while when recording every paths of LEDs lamp bar 505 and reaching setting electric current value, corresponding driving voltage
The value of VLED is more than setting short-circuit protection voltage if the difference of the corresponding driving voltage VLED of any two paths of LED lamp bar 505
Threshold value then determines that LED short circuit occurs in the lower LED light bar 505 of the value of driving voltage VLED, is disconnected by the first metal-oxide-semiconductor 504
The LED light bar 505 of short circuit.Wherein, this short-circuit protection voltage threshold value can pass through the LED light bar 505 of the normal backlight of scanning
Driving voltage difference to be determined by the intelligence of the LED multi-path driving chip 503, also can be set as fixed voltage value.
The principle for the LED short-circuit protection that the multi partition backlight driving system 500 is realized in backlight course of normal operation is big
It causes are as follows:
Driving voltage Vgs is held essentially constant after starting initialization.When LED backlight drives and works normally, driving is single
Member 5030 is according to certain time interval, certain voltage step-length, to attempt to improve driving voltage Vgs to improve LED current Id, simultaneously
PWM duty cycle is reduced to reach so that the electric current Id* duty ratio D of every paths of LEDs lamp bar 505 remains setting electric current value and remain steady
It is fixed, referring to the normal operating condition 701 in Fig. 7.
It can be reduced if there is certain 505 short circuit of paths of LEDs lamp bar, this 505 pressure drop of paths of LEDs lamp bar caused by component damage,
Driving unit 5030 can be according to certain time interval above-mentioned, certain voltage step-length, to attempt to improve the LED light bar that there is short circuit
505 electric current, while its conducting dutycycle is reduced, to prevent corresponding first metal-oxide-semiconductor 504 due to the pressure drop of Drain-Source
High and damage of generating heat.In conjunction with referring to the short-circuit trigger process 702 in Fig. 7, when this 505 electric current of paths of LEDs lamp bar reaches the electricity of setting
When stream protection point 703, then it is determined as short circuit occur, the LED light bar 505 of short circuit is disconnected by turning off first metal-oxide-semiconductor 504, prevent
Only LED light bar 505 is generated heat for a long time/is caused and is on fire, while avoiding damaging other normal LED in the LED light bar 505 of failure.
Compared with prior art, by the present invention in that each driving unit 5030 can be according to certain time interval, certain electricity
Step-length is pressed, to attempt to improve driving current, while reducing PWM duty cycle, enables the product of driving current and PWM duty cycle
Reach and maintain to stablize in setting value, is more than the protection voltage of setting in the difference of the driving voltage of any two paths of LED lamp bar 505
When threshold value, it is possible to determine that there is short circuit lighting backlight process, it, can be with when driving current reaches the current protection point of setting
Determine short circuit occur in backlight course of normal operation, and then can be when determining that short circuit occurs, by turning off the first metal-oxide-semiconductor 504
Come disconnect short circuit LED light bar 505, the safety of liquid crystal display device can be effectively improved.
Above content, only presently preferred embodiments of the present invention, are not intended to limit embodiment of the present invention, and this field is general
Logical technical staff's central scope according to the present invention and spirit can very easily carry out corresponding flexible or modification, therefore originally
The protection scope of invention should be subject to protection scope required by claims.
Claims (10)
1. a kind of short-circuit protection method of multi partition LED backlight, which is characterized in that
Making multi partition backlight driving system includes: LED drive power;LED multi-path lamp bar, the anode of each paths of LEDs lamp bar simultaneously connect this
The driving voltage that LED drive power provides;Microprocessor, including multiple driving units, each driving unit is for controlling correspondence
LED light bar all the way driving current;First metal-oxide-semiconductor is connected with corresponding LED light bar, be controlled by corresponding driving unit and
Closure/disconnection;Current sampling resistor is supplied to the driving unit for sampling the driving current of corresponding LED light bar;
Reduce each driving unit can to attempt to improve driving current simultaneously according to certain time interval, certain voltage step-length
PWM duty cycle enables driving current and the product of PWM duty cycle to reach and maintains to stablize in setting value, to terminate to light
Backlight starts and enters backlight course of normal operation;
Backlight process is being lighted, if the difference of the driving voltage of any two paths of LED lamp bar is more than the protection voltage threshold of setting
Value then determines that short circuit occurs in the lower LED light bar of driving voltage value, and then can disconnect the paths of LEDs by the first metal-oxide-semiconductor of shutdown
Lamp bar;
In backlight course of normal operation, if the driving current of certain paths of LEDs lamp bar reaches the current protection point of setting, determining should
There is short circuit in paths of LEDs lamp bar, and then can disconnect the paths of LEDs lamp bar by the first metal-oxide-semiconductor of shutdown.
2. the short-circuit protection method of multi partition LED backlight according to claim 1, which is characterized in that keep each driving single
Member includes the second metal-oxide-semiconductor, and the drain electrode of second metal-oxide-semiconductor is connected with the source electrode of first metal-oxide-semiconductor, the source electrode of second metal-oxide-semiconductor and
The current sampling resistor is connected.
3. the short-circuit protection method of multi partition LED backlight according to claim 2, which is characterized in that make first metal-oxide-semiconductor
Work in switch state;Second metal-oxide-semiconductor works in linear condition.
4. the short-circuit protection method of multi partition LED backlight according to claim 3, which is characterized in that keep each driving single
Member further includes operational amplifier, and the output of the operational amplifier terminates the grid of the second metal-oxide-semiconductor of the driving unit, which puts
One input terminal of big device is connected with the grid of first metal-oxide-semiconductor, another input terminal and electric current of the operational amplifier are adopted
Sample resistance is connected.
5. the short-circuit protection method according to the described in any item multi partition LED backlights of Claims 1-4, which is characterized in that make this
LED drive power is Switching Power Supply, during lighting backlight, the LED drive power provide driving voltage be it is controlled gradually
It raises.
6. a kind of liquid crystal display device, including liquid crystal display panel and multi partition backlight driving system, which is characterized in that multi partition back
Optical drive system includes: LED drive power;LED multi-path lamp bar, the anode of each paths of LEDs lamp bar simultaneously connect LED drive power offer
Driving voltage;Microprocessor, including multiple driving units, each driving unit is for controlling corresponding LED light bar all the way
Driving current;First metal-oxide-semiconductor is connected with corresponding LED light bar, is controlled by corresponding driving unit and is closed/disconnects;Electric current is adopted
Sample resistance is supplied to the driving unit for sampling the driving current of corresponding LED light bar;
Wherein, each driving unit can be according to certain time interval, certain voltage step-length, to attempt to improve driving current, simultaneously
PWM duty cycle is reduced, driving current and the product of PWM duty cycle are reached and is maintained to stablize in setting value, to terminate
That lights backlight starts and enters backlight course of normal operation;
Backlight process is being lighted, if the difference of the driving voltage of any two paths of LED lamp bar is more than the protection voltage threshold of setting
Value then determines that short circuit occurs in the lower LED light bar of driving voltage value, and then can disconnect the paths of LEDs by the first metal-oxide-semiconductor of shutdown
Lamp bar;
In backlight course of normal operation, if the driving current of certain paths of LEDs lamp bar reaches the current protection point of setting, determining should
There is short circuit in paths of LEDs lamp bar, and then can disconnect the paths of LEDs lamp bar by the first metal-oxide-semiconductor of shutdown.
7. liquid crystal display device according to claim 6, which is characterized in that each driving unit includes the second metal-oxide-semiconductor, should
The drain electrode of second metal-oxide-semiconductor is connected with the source electrode of first metal-oxide-semiconductor, and the source electrode of second metal-oxide-semiconductor is connected with the current sampling resistor.
8. liquid crystal display device according to claim 7, which is characterized in that first metal-oxide-semiconductor works in switch state;It should
Second metal-oxide-semiconductor works in linear condition.
9. liquid crystal display device according to claim 8, which is characterized in that each driving unit further includes operation amplifier
Device, the output of the operational amplifier terminate the grid of the second metal-oxide-semiconductor of the driving unit, an input terminal of the operational amplifier
It is connected with the grid of first metal-oxide-semiconductor, another input terminal of the operational amplifier is connected with the current sampling resistor.
10. according to the described in any item liquid crystal display devices of claim 6 to 9, which is characterized in that the LED drive power is out
Powered-down source, during lighting backlight, the driving voltage which provides is controlled gradually to raise.
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CN109584829B (en) * | 2018-12-25 | 2020-10-30 | 惠科股份有限公司 | Overcurrent protection method, display panel and overcurrent protection device |
CN109713637B (en) | 2018-12-27 | 2020-09-15 | 惠科股份有限公司 | Overcurrent protection method, overcurrent protection circuit and display device |
TWI696987B (en) * | 2019-04-18 | 2020-06-21 | 友達光電股份有限公司 | A display device and a backlight driving method thereof |
CN112908232B (en) * | 2021-03-26 | 2022-10-18 | 四川长虹电器股份有限公司 | LED multi-partition backlight fault detection system and fault judgment method |
CN113314065B (en) * | 2021-06-04 | 2023-03-31 | 豪威触控与显示科技(深圳)有限公司 | Driving method, pixel circuit and display panel |
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CN109243379B (en) | 2020-10-23 |
CN106409241A (en) | 2017-02-15 |
CN109243379A (en) | 2019-01-18 |
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