CN106328067A - Backlight source module and liquid crystal display device - Google Patents
Backlight source module and liquid crystal display device Download PDFInfo
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- CN106328067A CN106328067A CN201510340113.0A CN201510340113A CN106328067A CN 106328067 A CN106328067 A CN 106328067A CN 201510340113 A CN201510340113 A CN 201510340113A CN 106328067 A CN106328067 A CN 106328067A
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- led strip
- backlight module
- led
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- strip row
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Abstract
The present invention provides a backlight source module and a liquid crystal display device. The backlight source module comprises a plurality of LED intandem and a dimming controller, wherein each LED intandem is formed by connecting a plurality of LED in series, and an LED intandem current flows through each LED intandem; the dimming controller is used to control the duty ratio of a voltage pulse outputted to each LED intandem, a product value can be obtained by multiplying the current of each LED intandem by the duty ratio of the voltage pulse of each LED intandem, and the product values are same substantially.
Description
Technical field
The present invention relates to a backlight module and use the liquid crystal indicator of this backlight module, and especially
Relate to circuit area reduce the backlight module making cost decline and use the liquid crystal display of this backlight module
Device
Background technology
Existing backlight module is widely used light emitting diode (hereinafter referred to as LED) come as liquid
The light source of crystal device.According to the physical characteristic of LED, the brightness of LED can be big according to the electric current flow through
Depending on little.Therefore equalizing circuit can be utilized on circuit framework to control the electric current of each LED strip row, really
The brightness protecting LED backlight is homogeneous.
Fig. 1 is to show that known use equalizing circuit controls the size of current of each LED strip row in backlight module
Schematic diagram.Backlight module possesses multiple LED strip row S1, S2, each LED strip row has many
Individual LED strip connection forms.Each LED strip row can receive the direct current that DC-to-DC converter 10 is provided
Voltage VLED, is in series with a field effect respectively between cathode terminal and the ground connection in each LED strip Herba Orobanches
Answer transistor and resistance.Microcontroller 20 is flowed by the cross-pressure of the resistance detected in each tandem
Cross the electric current of this tandem, then adjust the equiva lent impedance of the field-effect transistor in each tandem and make to flow through each
The electric current of tandem is equal.Here, multiple field-effect transistors constitute equalizing circuit 30.Known technology utilizes control
The control circuit (i.e. microcontroller 20) of chip internal processed controls the equalizing circuit 30 of outside.But,
Along with panel size is done bigger and bigger, LED number and tandem number that backlight module is used get more and more,
Therefore it is also required to the bigger equalizing circuit of area to control the electric current of each tandem, which results in circuit cost
Problem the highest, that circuit volume is excessive.
The present invention is in view of above-mentioned problem points, and proposes a kind of circuit face reduced needed for equalizing circuit
Amass and reduce the backlight module making cost decline.
Summary of the invention
The present invention proposes a kind of backlight module, including: multiple LED strip arrange, each LED strip arrange by
Multiple LED strip connection forms and flows through a LED strip row electric current；And a light adjusting controller, in order to control
The dutycycle (duty cycle) of the potential pulse that system output arranges to each this LED strip, wherein each this LED
The dutycycle of this potential pulse that tandem electric current is multiplied by each this LED strip row is respectively a product value, each
This product value is substantially the same.In the present invention, what is called " being substantially the same " includes the mistake between numerical value
Difference situation in ± 6%, wherein source of error is algorithm or hardware conversion or actual conjunction when measuring
Reason range of error.
According to an embodiment of the present invention, in above-mentioned backlight module, this light adjusting controller includes: one
Light modulation block, during switching the conducting of each this LED strip row；And one instruction transmit receive block, root
Duty cycle information needed for arranging according to each this LED strip controls this light modulation block.
In above-mentioned backlight module, this instruction is transmitted reception block and is connect by wired or wireless communication mode
Receive this duty cycle information exported by a controller.
In above-mentioned backlight module, this controller storage has the characterisitic parameter calculating each this LED strip row
Obtain the algorithm of this duty cycle information.
Above-mentioned backlight module, the characterisitic parameter of this LED strip row that this controller receives is by a sense
Electro-optical device is measured the luminescence of this backlight module and is obtained.
Again according to another kind embodiment of the present invention, this light adjusting controller of above-mentioned backlight module also includes:
One light modulation block, during switching the conducting of each this LED strip row；And an operational block, storage has meter
Calculate the characterisitic parameter of each this LED strip row to obtain the algorithm of duty cycle information of each this LED strip row,
And the duty cycle information needed for arranging according to each this LED strip controls this light modulation block.
In above-mentioned backlight module, the characterisitic parameter of this LED strip row of this operational block is by a sense
Electro-optical device is measured the luminescence of this backlight module and is obtained.
The present invention is it is also proposed that a kind of liquid crystal indicator, including a display panels；And above-mentioned two
The backlight module of any one in embodiment.
According to above-mentioned backlight module and liquid crystal indicator, the present invention reduces in backlight module required really
Circuit area, make cost decline.Again because there is no the power dissipation of equalizing circuit, it is possible to decrease LED strip
The caloric value of row, and improving luminous efficiency.
Accompanying drawing explanation
Fig. 1 is to show that known use equalizing circuit controls the size of current of each LED strip row in backlight module
Schematic diagram.
Fig. 2 is the schematic diagram of the brightness adjustment step showing the backlight module according to the present invention.
Fig. 3 is to show to use light adjusting controller to adjust the flat of each LED strip row according to an embodiment of the invention
All schematic diagrams of current value.
Fig. 4 shows that using light adjusting controller to adjust each LED strip according to another embodiment of the present invention arranges
The schematic diagram of average current value.
Fig. 5 A is an example of the current value illustrating that the present invention flows through each LED strip row.
Fig. 5 B is an example of the potential pulse illustrating that the present invention is supplied to each LED strip row.
Fig. 5 C is the average of each LED strip row after the electric current showing Fig. 5 A is multiplied with the dutycycle of Fig. 5 B
Electric current.
[symbol description]
10～DC-to-DC converter；
20～microcontroller；
30～equalizing circuit；
201～backlight module；
202～photosensitive device；
203～controller；
204～light adjusting controller；
2041～instruction transmit receive block；
2042～light modulation block；
2043～operational block；
ILED1、ILED2、ILED64～electric current；
T1, t2, t64～pulse length；
T～pulse period；
S1, S2, S64～LED strip row.
Detailed description of the invention
The backlight of the display device of the present invention is described below according to accompanying drawing.In different accompanying drawings and correspondence
Explanation indicates identical symbol and represents that identical element omits repeat specification.
Present invention removes the equalizing circuit in known technology, and use light adjusting controller to adjust each
The mode of the dutycycle (Duty Cycle) of the potential pulse of LED strip row reaches the luminescence of backlight module
The effect that brightness is homogeneous.Owing to light adjusting controller is to be made in chip internal, therefore eliminate equalizing circuit institute
The circuit area needed, and then reduce cost of manufacture.
Fig. 2 is the schematic diagram of the brightness adjustment step showing the backlight module according to the present invention.First, make
The backlight module 201 with multiple LED strip row is luminous, and to have the photo-sensitive cells such as such as CCD
Photosensitive device 202 measures the brightness of each LED strip row in backlight module 201.Photosensitive device 202 will
Measurement result transmission or storage are to controller 203 or light adjusting controller.Controller 203 prestores
About the characteristic information (brightness and the relation of electric current, the relation etc. of electric current and required dutycycle) of LED,
Then measurement result is combined these information, calculates the duty of potential pulse needed for each LED strip row
Ratio.Light adjusting controller 204 is according to above-mentioned duty cycle information, and it is each that adjustment exports to backlight module 201
The dutycycle of the potential pulse of individual LED strip row, the current average making each LED strip arrange is equal, from
And reach the effect that LED luminance is homogeneous.
Fig. 3 is to show to use light adjusting controller to adjust the flat of each LED strip row according to an embodiment of the invention
All schematic diagrams of current value.In figure 3, there are 64 LED strip row, figure is only enumerated tandem S1,
As a example by S2, S64.As it is shown on figure 3, have more instruction in light adjusting controller 204 to transmit reception block 2041
And light modulation block 2042.Instruction transmits reception block 2041 and is used to receive what controller 203 was exported
Duty cycle information.Controller 203 can transmit dutycycle by various wired or wireless communication protocols to be believed
Breath transmits to instruction and receives block 2041.Transmit reception block 2041 to control to be somebody's turn to do according to this duty cycle information
Light modulation block 2042 arranges the adjustment during turning on to each LED strip.Make to flow through each LED strip
The electric current I of row S1, S2, S64LED1、ILED2、ILED64Although different, but the electric current of each tandem is multiplied by this
Can obtain the product value being substantially the same after the dutycycle of the potential pulse of tandem, be i.e. substantially the same is flat
All electric currents.In the present invention, what is called " being substantially the same " includes that the error between numerical value is in ± 6%
Situation, wherein source of error is algorithm or hardware conversion or actual reasonable error scope when measuring.
In the middle of Fig. 3, the present invention completely removes the equalizing circuit in known technology, and dims district
Block 2042 belongs to the circuit in light adjusting controller (chip), additional circuit that therefore need not be complicated, only makes
Just can be by brightness homogeneous for backlight module furnishing with the light modulation circuit in IC chip.Therefore circuit is greatly decreased
Area, thus reduce manufacturing cost.Again because having minused the cross-pressure on equalizing circuit on LED strip row,
Therefore eliminate unnecessary power efficiency, reduce the caloric value of LED strip row, improving luminous efficiency.
Also, according to another kind embodiment of the present invention, the calculation function of controller 203 can also be integrated into
In the middle of light adjusting controller 204.Fig. 4 is to show to use light adjusting controller according to another embodiment of the present invention
Adjust the schematic diagram of the average current value of each LED strip row.In the diagram, operational block 2043 directly has
There is the function of the controller 203 of Fig. 3, namely prestored the characteristic information (brightness about LED
Relation etc. with the relation of electric current, electric current and required dutycycle), then the measurement result of photosensitive device is tied
Close these information, calculate the dutycycle of potential pulse needed for each LED strip row, then further according to respectively
Duty cycle information needed for this LED strip individual row controls light modulation block 2042 and leads each LED strip row
The adjustment of logical period.
Will be described below the relation of each LED strip row electric current, dutycycle and average current.Fig. 5 A is explanation
The present invention flows through an example of the current value of each LED strip row, as shown in FIG., flows through LED strip
The electric current of row S1, S2, S64 is different, respectively ILED1、ILED2、ILED64.Light adjusting controller root
According to the electric current of each tandem, provide potential pulse as shown in Figure 5 B respectively.As shown in FIG., each LED
Tandem S1, the potential pulse length of S2, S64 are respectively t1, t2, t64, therefore dutycycle be respectively t1/T,
t2/T、t64/T.The electric current flowing through tandem is the biggest, it is provided that the least to the dutycycle of this tandem.Therefore,
Obtaining average current as shown in Figure 5 C, each tandem S1, the electric current of S2, S64 are ILED1、ILED2、
ILED64, after being multiplied by its dutycycle t1/T, t2/T, t64/T, just obtain identical average current (ILED1×
(t1/T)=ILED2× (t2/T)=ILED64×(t64/T))。
The present invention does not change the current value flowing through each LED strip row, but by providing different voltage
Pulse duty factor, the electric current making each LED strip arrange is multiplied by the potential pulse dutycycle of this LED strip row
Product value is substantially the same, i.e. the average current of each LED strip row is substantially the same.Because each LED
The average current of tandem is substantially the same, so the mean flow rate of each LED strip row is the most all substantially the same.
Therefore present invention is equally capable to reach the effect by homogeneous for the brightness adjustment of LED backlight module.
It addition, the difference of the local dimming of the explanation present invention and known technology.Local dimming technology is also
Backlight is done zones of different, the regulation of light and shade change in various degree, mat by the available mode adjusting dutycycle
This is greatly reduced power consumption, improves display picture contrast, increases ash exponent number, reduces ghost etc..But,
Local dimming technology is in the backlight module applying to employ equalizing circuit, owing to equalizing circuit makes respectively
The electric current of individual LED strip row is equal and produces homogeneous brightness.When using local dimming technology, adjust each
The dutycycle of LED strip row, the average current making different LED strip arrange is different, and it is different to produce subregion
Brightness.It is thus known that the local dimming of technology is poor in order to make the brightness in each region of backlight module produce
Different, and the present invention is intended to allow brightness homogeneous in each region of backlight module, both purposes are the most contrary.
It is also known that the local dimming of technology is also to be used in have in the middle of the backlight module of equalizing circuit, the most also
The backlight module the most not possessing equalizing circuit from the application is different.
And the liquid crystal indicator that the backlight module of the present invention mainly applies to have liquid crystal city panel is worked as
In, the backlight as this liquid crystal indicator uses.
Backlight module according to the above description and liquid crystal indicator, the present invention reduces backlight module really
Circuit area needed in, makes cost decline.Again because there is no the power dissipation of equalizing circuit, it is possible to decrease
The caloric value of LED strip row, and improving luminous efficiency.
Claims (8)
1. a backlight module, including:
Multiple LED strip arrange, and each LED strip arranges and formed by multiple LED strip connection and flow through a LED
Tandem electric current；And
Light adjusting controller, in order to control the dutycycle (duty of the potential pulse exported to each this LED strip row
Cycle),
Wherein each this LED strip row electric current is multiplied by the dutycycle of this potential pulse that each this LED strip arranges
Being respectively a product value, each this product value is substantially the same.
2. backlight module as claimed in claim 1, wherein this light adjusting controller includes:
Light modulation block, during switching the conducting of each this LED strip row；And
Instruction transmits and receives block, and the duty cycle information needed for arranging according to each this LED strip controls this light modulation
Block.
3. backlight module as claimed in claim 2, wherein this instruction transmits and receives block by wired
Or communication receives this duty cycle information exported by controller.
4. backlight module as claimed in claim 3, wherein this controller storage has each this LED of calculating
The characterisitic parameter of tandem obtains the algorithm of this duty cycle information.
5. backlight module as claimed in claim 4, this LED strip row that wherein this controller receives
Characterisitic parameter is to measure the luminescence of this backlight module by photosensitive device and obtain.
6. backlight module as claimed in claim 1, wherein this light adjusting controller also includes:
Light modulation block, during switching the conducting of each this LED strip row；And
Operational block, storage has the characterisitic parameter calculating each this LED strip row to obtain each this LED
The algorithm of the duty cycle information of tandem, and control to be somebody's turn to do according to the duty cycle information needed for each this LED strip row
Light modulation block.
7. backlight module as claimed in claim 6, the wherein spy of this LED strip row of this operational block
Property parameter is to measure the luminescence of this backlight module by photosensitive device and obtain.
8. a liquid crystal indicator, including:
Display panels；And
Backlight module as claimed in claim 1.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510340113.0A CN106328067A (en) | 2015-06-18 | 2015-06-18 | Backlight source module and liquid crystal display device |
| US15/184,101 US20160374165A1 (en) | 2015-06-18 | 2016-06-16 | Backlight module and liquid-crystal display device using the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510340113.0A CN106328067A (en) | 2015-06-18 | 2015-06-18 | Backlight source module and liquid crystal display device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN106328067A true CN106328067A (en) | 2017-01-11 |
Family
ID=57733226
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510340113.0A Pending CN106328067A (en) | 2015-06-18 | 2015-06-18 | Backlight source module and liquid crystal display device |
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| Country | Link |
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1776497A (en) * | 2004-11-19 | 2006-05-24 | 索尼公司 | Backlight device, method of driving backlight and liquid crystal display apparatus |
| CN101185173A (en) * | 2005-06-20 | 2008-05-21 | 罗姆股份有限公司 | Light emission control circuit for lighting a plurality of light emitting elements, and illuminating apparatus and mobile information terminal having the same |
| CN101253813A (en) * | 2005-08-26 | 2008-08-27 | 飞利浦拉米尔德斯照明设备有限责任公司 | LED light source for backlighting with integrated electronics |
| CN101848574A (en) * | 2009-03-27 | 2010-09-29 | 北京京东方光电科技有限公司 | Drive device of light emitting diode backlight source and brightness adjustment method |
| CN103118455A (en) * | 2011-10-24 | 2013-05-22 | 万国半导体股份有限公司 | LED current control |
-
2015
- 2015-06-18 CN CN201510340113.0A patent/CN106328067A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1776497A (en) * | 2004-11-19 | 2006-05-24 | 索尼公司 | Backlight device, method of driving backlight and liquid crystal display apparatus |
| CN101185173A (en) * | 2005-06-20 | 2008-05-21 | 罗姆股份有限公司 | Light emission control circuit for lighting a plurality of light emitting elements, and illuminating apparatus and mobile information terminal having the same |
| CN101253813A (en) * | 2005-08-26 | 2008-08-27 | 飞利浦拉米尔德斯照明设备有限责任公司 | LED light source for backlighting with integrated electronics |
| CN101848574A (en) * | 2009-03-27 | 2010-09-29 | 北京京东方光电科技有限公司 | Drive device of light emitting diode backlight source and brightness adjustment method |
| CN103118455A (en) * | 2011-10-24 | 2013-05-22 | 万国半导体股份有限公司 | LED current control |
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Application publication date: 20170111 |
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