CN101452677B - Driving device, backlight module and driving method - Google Patents
Driving device, backlight module and driving method Download PDFInfo
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- CN101452677B CN101452677B CN2007101962390A CN200710196239A CN101452677B CN 101452677 B CN101452677 B CN 101452677B CN 2007101962390 A CN2007101962390 A CN 2007101962390A CN 200710196239 A CN200710196239 A CN 200710196239A CN 101452677 B CN101452677 B CN 101452677B
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- 238000000034 method Methods 0.000 title claims description 25
- 238000001514 detection method Methods 0.000 claims abstract description 29
- 239000004973 liquid crystal related substance Substances 0.000 claims abstract description 21
- 239000010409 thin film Substances 0.000 claims description 6
- 238000004020 luminiscence type Methods 0.000 description 56
- 238000010586 diagram Methods 0.000 description 12
- 230000007246 mechanism Effects 0.000 description 6
- 230000008901 benefit Effects 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 230000004438 eyesight Effects 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 230000008034 disappearance Effects 0.000 description 1
- 238000005401 electroluminescence Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000010363 phase shift Effects 0.000 description 1
- 230000004044 response Effects 0.000 description 1
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Abstract
The invention discloses a driving device for driving a backlight module of a liquid crystal display, which comprises a driving unit and an error detection unit. The driving unit is used for driving the plurality of light emitting units in the backlight module to emit light. The error detection unit is used for respectively calculating a current error of each light-emitting unit. When the current error exceeds a first threshold value, the error detection unit controls the driving unit to stop driving the light-emitting unit to emit light.
Description
Technical field
The present invention relates to a kind of drive unit and method, and particularly relate to a kind of drive unit and method of the backlight module in order to the driving liquid crystal device.
Background technology
Increasingly mature along with the Internet and wireless communication technique in recent years; Various portable information products come across market and fast development in succession; For example mobile computer (notebook), mobile phone (mobile phone) and personal digital assistant (Personal Digital Assistant, PDA) etc.(Cathode Ray Tube, CRT) therefore display is not suitable for these portable information products because volume is big, Heavy Weight and demand electric weight are high to conventional cathode ray tube.Therefore, have slimming, lightweight, (Liquid Crystal Display LCD) just becomes the main flow of display in response to the informationalized trend of this number of share of stock word than the LCD of advantages such as low power consumption.
The LCD that is widely used on the market at present is Thin Film Transistor-LCD (ThinFilm Transistor Liquid Crystal Display; TFT-LCD); Its panel itself is not luminous, but the light that sends through backlight module through the liquid crystal molecule on the panel to present various color ranges and then display image.The employed light emitting source of backlight module has cold-cathode tube (Cold Cathode FluorescentLamp; CCFL), thermionic-cathode tube (Hot Cathode Fluorescent Lamp; HCFL), light emitting diode (Light Emitting Diode; LED) and the electroluminescence sheet (Electro-Luminscence, EL) etc., wherein cold-cathode tube has characteristic such as the long and various shapes of high briliancy, high-level efficiency, life-span and becomes the employed main stream light sources of present backlight module.
The backlight liquid crystal display area of large size panel is big, and relatively required cold-cathode tube number is more, therefore, keeps the luminance difference of these cold-cathode tubes in permissible scope, also to be the research emphasis of backlight module.Cold-cathode tube lighting brightness is decided by the electric current that flows through cold-cathode tube, is the equal stream mechanism through drive unit so keep uniform luminance, makes the electric current that flows through each cold-cathode tube identical haply.Yet, because every cold-cathode tube all has its stray capacitance and variation parameter, thus the generation of equal stream mechanism is arranged, yet all stream mechanism also can't to guarantee to flow through the electric current of every cold-cathode tube identical, so brightness difference to some extent still.When luminance difference is excessive between any two fluorescent tubes,, possibly make beholder's eyes uncomfortable even damage its eyesight to such an extent as to can cause the inhomogeneous display image of panel picture brightness to change.
Summary of the invention
Therefore, a category of the present invention is to provide a kind of drive unit, in order to the backlight module of driving liquid crystal device.Especially, drive unit of the present invention can be controlled the switch of backlight module according to current difference, improves the disappearance in the known skill.
According to a specific embodiment, the present invention discloses a kind of drive unit in order to driving liquid crystal device backlight module, and it comprises driver element and error detection unit.A plurality of luminescence units make it luminous to driver element in the backlight module in order to drive.Error detection unit is then in order to calculate the current error of each luminescence unit respectively.When the current error that is calculated surpassed a first threshold, it is luminous that the error detection unit control drive unit makes it stop the driven for emitting lights unit.
According to another specific embodiment, error detection unit of the present invention further comprises subtracter, comparer and transmitter.The function mode of error detection unit is following: at first, measure the electric current difference between each luminescence unit respectively by subtracter; Then, comparer calculates the current error of each luminescence unit respectively according to the electric current of electric current difference and each luminescence unit; At last, when the current error that is calculated surpasses first threshold, transmitter will send the first control signal control drive unit, and it is luminous to make driver element stop the driven for emitting lights unit.
According to another specific embodiment, drive unit of the present invention further comprises protected location.When the voltage when arbitrary luminescence unit is opened a way surpasses one second threshold value, protected location will send the second control signal control drive unit, and it is luminous to make driver element stop the driven for emitting lights unit.In addition; In this specific embodiment; When the current error that is calculated surpasses first threshold, transmitter will send first and control signal to protected location, and it is luminous to cause the further transmission of the protected location second control signal control drive unit to make it stop the driven for emitting lights unit.
Another category of the present invention is to provide a kind of backlight module, in order to the light source as LCD.
According to a specific embodiment, backlight module of the present invention comprises a plurality of luminescence units and drive unit.Drive unit is luminous in order to drive said luminescence unit.In addition, drive unit can calculate the current error of each luminescence unit respectively.When current error surpassed first threshold, it is luminous that drive unit will stop to drive these luminescence units.In addition, the drive unit of backlight module of the present invention further comprises driver element and error detection unit.A plurality of luminescence units make it luminous to driver element in the backlight module in order to drive, and error detection unit is then in order to calculate the current error between each luminescence unit respectively.
Another category of the present invention is to provide a kind of driving method, in order to the backlight module of driving liquid crystal device.
According to a specific embodiment, driving method of the present invention comprises the following step: at first, the luminescence unit that drives backlight module is luminous; Then, calculate current error between each luminescence unit respectively; At last, when error surpassed first threshold, it was luminous to stop the driven for emitting lights assembly.
Can further be understood through following detailed Description Of The Invention and accompanying drawing about advantage of the present invention and spirit.
Description of drawings
Figure 1A shows according to the drive unit of a specific embodiment of the present invention and the synoptic diagram of luminescence unit.
Figure 1B shows the synoptic diagram of the inner structure of error detection unit among Figure 1A.
Fig. 1 C shows the synoptic diagram that the drive unit according to another specific embodiment of the present invention is connected with luminescence unit.
Fig. 1 D shows the synoptic diagram that the drive unit according to another specific embodiment of the present invention is connected with luminescence unit.
Fig. 2 A shows the synoptic diagram according to the backlight module of a specific embodiment of the present invention.
Fig. 2 B shows the synoptic diagram according to the backlight module of another specific embodiment of the present invention.
Fig. 3 A is according to the flow chart of steps of the driving method of a specific embodiment of the present invention.
Fig. 3 B shows the flow chart of steps according to the driving method of another specific embodiment of the present invention.
Fig. 3 C shows the flow chart of steps according to the driving method of another specific embodiment of the present invention.
The reference numeral explanation
1,32: drive unit 10,320: driver element
12,322: error detection unit 14,324: protected location
2,24,26,28,30: luminescence unit 30: backlight module
S10-S16: process step S120, S122: process step
Embodiment
Please refer to Figure 1A, Figure 1A shows according to the drive unit 1 of a specific embodiment of the present invention and the synoptic diagram of luminescence unit 2.Drive unit 1 is in order to a plurality of luminescence units 2 in the backlight module of driving liquid crystal device.In practical application, LCD can be, but is not subject to, like Thin Film Transistor-LCD.Luminescence unit 2 then can be, but is not subject to, like cold cathode ray tube.
In this specific embodiment, this backlight module comprises three luminescence units 24,26,28.Shown in Figure 1A, drive unit 1 comprises driver element 10 and error detection unit 12.Driver element 10 is luminous in order to driven for emitting lights unit 2, and wherein, driver element 10 has equal stream mechanism, and to stablize the voltage and the electric current of each luminescence unit 24,26,28, the luminance brightness that each luminescence unit 24,26,28 is sent is identical haply.Error detection unit 12 can be calculated the current error of each luminescence unit 24,26,28 respectively; Reach the effect of secondary current-sharing; And; When current error surpassed first threshold, error detection unit 12 was sent the first control signal control drive unit 10, and it is luminous to make driver element 10 stop driven for emitting lights unit 2.
In practice, first threshold can be set at 5% error range, and in existing liquid crystal display drive circuit, this 5% error range is approximately 1 milliampere (mA).For example, when the current error that detects luminescence unit 24,26,28 respectively when error detection unit 12 was 3%, 2%, 2%, because there is not the current error of luminescence unit to surpass first threshold (5%), therefore, said luminescence unit 2 was kept normally luminous.And the current error that detects luminescence unit 24,26,28 respectively when error detection unit 12 is when being 3%, 7%, 2%; Because the current error of luminescence unit 26 surpasses first threshold, so error detection unit 12 is sent, and first control signal control control drive unit 10 stops driven for emitting lights unit 26 or all luminescence unit 2 is luminous.Note that first threshold can be set at other numerical value according to circumstances, is not limited to aforesaid 5%.
Please refer to Figure 1B, Figure 1B shows the synoptic diagram of the inner structure of error detection unit 12 among Figure 1A.Shown in Figure 1B, according to another specific embodiment of the present invention, error detection unit 12 comprises subtracter 120, comparer 122 and transmitter 124.Subtracter 120 is in order to measure the electric current difference of 2 of each luminescence units respectively.On practice, subtracter 120 can an operational amplifier collocation subtraction circuit and forming.Comparer 122 calculates the current error of each luminescence unit 2 respectively according to the electric current of electric current difference and each luminescence unit 2.124 of transmitters send the first control signal control drive unit 10 when current error surpasses first threshold, it is luminous to make driver element 10 stop driven for emitting lights unit 2.
Please refer to Fig. 1 C, Fig. 1 C shows the synoptic diagram that the drive unit 1 according to another specific embodiment of the present invention is connected with luminescence unit 2.Shown in Fig. 1 C, in this specific embodiment, drive unit 1 further comprises protected location 14 except each assembly with above-mentioned specific embodiment.When the voltage of arbitrary luminescence unit 2 open circuits surpasses second threshold value, protected location 14 will send the second control signal control drive unit 10, and it is luminous to make driver element 10 stop driven for emitting lights unit 2.In practice, second threshold value be higher than when open circuit luminescence unit the normal voltage that should have be worth 650 volts.Certainly, in practical application, second threshold value can be set at other numerical value according to circumstances, is not limited to aforesaid 650 volts.
In addition, please refer to Fig. 1 D, Fig. 1 D shows the synoptic diagram that the drive unit 1 according to another specific embodiment of the present invention is connected with luminescence unit 2.Shown in Fig. 1 D; In this specific embodiment; When current error surpasses first threshold; Error detection unit 12 will be sent first and controlled signal to protected location 14, cause protected location 14 further to send the second control signal control drive unit 10, and it is luminous to make driver element 10 stop driven for emitting lights unit 2.
In practice; The structure of the driver element 1 of above-mentioned each specific embodiment can comprise current fed type antiresonant circuit structure, half bridge series resonance converter structure, full-bridge phase shift converter structure and push-pull converter structure, or other appropriate driving device structure.
Please refer to Fig. 2 A, Fig. 2 A shows the synoptic diagram according to the backlight module 3 of a specific embodiment of the present invention.Shown in Fig. 2 A, backlight module 3 of the present invention comprises luminescence unit 30 and drive unit 32.Note that in fact luminescence unit 30 comprises a plurality of luminescence units shown in Figure 1A,, in Fig. 2 A, represent whole luminescence units with a luminescence unit 30 for keeping the succinct of drawing.Drive unit 32 is luminous in order to driven for emitting lights unit 30.Wherein, drive unit 32 has equal stream mechanism, and with voltage and the electric current of stablizing each luminescence unit 30, the luminance brightness that each luminescence unit 30 is sent is identical haply.In addition, drive unit 32 can calculate the current error of each luminescence unit 30 respectively, and when current error surpassed first threshold, it is luminous that drive unit 32 can stop driven for emitting lights unit 30.
In this specific embodiment, drive unit 32 can further comprise driver element 320 and error detection unit 322.Driver element 320 is luminous in order to driven for emitting lights unit 30.322 of error detection unit are in order to calculate the current error of each luminescence unit 30 respectively.
Please refer to Fig. 2 B, Fig. 2 B shows the synoptic diagram according to the backlight module 3 of another specific embodiment of the present invention.Shown in Fig. 2 B, drive unit 32 further comprises protected location 324.When the voltage when arbitrary luminescence unit 30 is opened a way surpassed second threshold value, protected location 324 can send the second control signal control drive unit 320, and it is luminous to make driver element 320 stop driven for emitting lights unit 30.In addition; In this specific embodiment; When current error surpasses first threshold; Error detection unit 322 can be sent first and controlled signal to protected location 324, causes protected location 324 further to send the second control signal control drive unit 320, and it is luminous to make driver element 320 stop driven for emitting lights unit 30.
In another specific embodiment, protected location 324 can be independent of outside the drive unit 32, yet its operation mechanism is still identical with above-mentioned specific embodiment, so repeat no more at this.
Please refer to Fig. 3 A, Fig. 3 A is the flow chart of steps according to the driving method of a specific embodiment of the present invention, and this driving method is in order to the backlight module of driving liquid crystal device.In this specific embodiment, driving method of the present invention comprises the following step: at first, in step S10, a plurality of luminescence units that drive in the backlight module are luminous; Then, in step S12, calculate the current error of each luminescence unit respectively; At last, in step S14, judge whether current error surpasses first threshold, and when current error surpassed first threshold, it was luminous to stop the driven for emitting lights unit.
Please refer to Fig. 3 B, Fig. 3 B shows the flow chart of steps according to the driving method of another specific embodiment of the present invention.Shown in Fig. 3 B, a driving method of this specific embodiment and a last specific embodiment difference are that step S12 further comprises the following step: in step S120, measure the electric current difference between each luminescence unit respectively; And, in step S122,, calculate the current error of each luminescence unit respectively according to the electric current of electric current difference and each luminescence unit.Other step of this specific embodiment is identical with corresponding step in the last specific embodiment, repeats no more at this.
Please refer to Fig. 3 C, Fig. 3 C shows the flow chart of steps according to the driving method of another specific embodiment of the present invention.Shown in Fig. 3 C, driving method of the present invention further comprises the following step: in step S16, the voltage when arbitrary luminescence unit is opened a way surpasses second threshold value, and it is luminous to stop the driven for emitting lights unit.Other step of this specific embodiment is identical with corresponding step in the above-mentioned specific embodiment, repeats no more at this.
Compared to prior art, the current error between each luminescence unit can measured and calculate to drive unit of the present invention and method, and when the current error between two luminescence units is excessive, backlight module will stop luminous.By this, can avoid the panel display brightness of LCD inhomogeneous, and then make beholder's eyes uncomfortable even damage its eyesight.
Through the detailed description of above preferred embodiment, hope can be known description characteristic of the present invention and spirit more, and is not to come category of the present invention is limited with the above-mentioned preferred embodiment that is disclosed.On the contrary, its objective is that hope can contain in the scope that is arranged in claim of the present invention of various changes and tool equality.Therefore, the scope of claim of the present invention should be done the broadest explanation according to above-mentioned explanation, contains the arrangement of all possible change and tool equality to cause it.
Claims (17)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2007101962390A CN101452677B (en) | 2007-11-30 | 2007-11-30 | Driving device, backlight module and driving method |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2007101962390A CN101452677B (en) | 2007-11-30 | 2007-11-30 | Driving device, backlight module and driving method |
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| Publication Number | Publication Date |
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| CN101452677A CN101452677A (en) | 2009-06-10 |
| CN101452677B true CN101452677B (en) | 2012-01-04 |
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| CN2007101962390A Expired - Fee Related CN101452677B (en) | 2007-11-30 | 2007-11-30 | Driving device, backlight module and driving method |
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Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102271438B (en) * | 2010-06-04 | 2013-12-25 | 金威贸易有限公司 | A Lighting Device Using Uniform AC Current to Drive Light Emitting Diodes |
| CN103680469B (en) * | 2013-12-23 | 2015-12-30 | 深圳市华星光电技术有限公司 | The method of adjustment of the brightness and contrast of a kind of liquid crystal display and liquid crystal display thereof |
| CN104680986B (en) * | 2015-03-19 | 2017-07-11 | 京东方科技集团股份有限公司 | A kind of backlight module, liquid crystal display and display device |
| CN110264928B (en) * | 2019-06-21 | 2022-05-27 | 上海创功通讯技术有限公司 | Backlight chip detection method and device and storage medium |
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