CN100466057C - Signal regulation module and relative display device - Google Patents

Abstract

The invention is concerned with the signal adjusting module that uses to adjust the driving signal of the light source producing equipment on a display board that outputs from a driving circuit, it includes: a floating current adjustor, a signal detector, and a feedback controller. It is: the floating current adjustor couples with the light producing equipment on the display board and the driving circuit, which adjusts the driving signal by the light coupling mode and adjusts the value of the driving signal according to a feedback signal; the signal detector couples with the floating current adjustor in order to produce a corresponding voltage signal by the light coupling mode according to the value of the driving signal; the feedback controller couples with the floating current adjustor and the signal detector in order to produce the feedback signal according to value of the voltage signal, and outputs the feedback signal to the floating current adjustor.

Description

Signal regulation module and related display apparatus

Technical field

The present invention relates to a kind of signal regulation module, particularly relate to a kind of signal regulation module that one drive circuit exports the driving signal of the light-source generation device on the display panel to that is used for adjusting.

Background technology

LCD (Liquid Crystal Display, LCD) mainly be the transistor that utilizes rectangular arrangement, cooperate electronic components such as suitable electric capacity, switch and switching pad to drive liquid crystal pixel on the display panels, enrich beautiful pattern with demonstration.Because characteristics such as LCD has that external form is frivolous, low power consumption and low radiation pollution, therefore be widely used in mobile computer, personal digital assistant (Personal Digital Assistant, PDA) and on the portable information product such as digital camera, existing conventional cathode ray tube (Cathode Ray Tube, CRT) trend of display of replacing gradually.

Generally speaking, LCD comprises a backlight module (Backlight Module), be located at the below or the side of display panels, and utilize the combination of at least one light source and various optical element (as diffuser plate, prism etc.), so that display panels high brightness and uniform light source to be provided, and then it is luminous to control liquid crystal pixel by the pixel electrode on the display panels, to show corresponding image.Backlight module is one of key part and component of lcd products, comprises a light source and a blooming piece, and homodisperse light source can be provided.Light source penetrates display panels, and by the pixel electrode of control on the display panels to form image.According to the position of light source, backlight module can be divided into straight-down negative (Direct-type) backlight module of light source generation under display panels, or light source is near the side-light type the display panels side (Edge-type) backlight module.Wherein, therefore can be applicable to the display panels of higher brightness demand or large-size, for example flat television because direct type backlight module is positioned at light source generator under the display panels.

Please refer to Fig. 1, Fig. 1 is the synoptic diagram of a LCD backlight module drive circuit 10 in the prior art.Backlight module drive circuit 10 comprises a plurality of transformer TR1-TRn, can drive fluorescent tube L1-Ln respectively.The backlight module drive circuit 10 of prior art uses one group of transformer to drive the framework of a fluorescent tube.Along with the increase that large scale is used, panel size is also towards large scale development, and the employed fluorescent tube quantity of LCD also increases gradually, and relatively backlight module drive circuit 10 also need be used more multiple transformers, and so cost also can significantly improve.

Please refer to Fig. 2, Fig. 2 is the synoptic diagram of another LCD backlight module drive circuit 20 in the prior art.Backlight module drive circuit 20 comprises a transformer TR, can drive fluorescent tube L1-Ln simultaneously, and the electric current by fluorescent tube L1-Ln is respectively by I _L1-I _LnRepresent.The backlight module drive circuit 20 of prior art uses one group of transformer to drive the framework of many fluorescent tubes simultaneously, therefore can reduce the usage quantity of transformer and driving switch when large scale is used, and then reduction backlight module cost.Though backlight module drive circuit 20 can significantly reduce cost, however the influence of limited fluorescent tube self character, and every lamp tube current I flows through _L1-I _LnMeeting is difference to some extent, causes the brightness difference of every fluorescent tube, so can influence the uniformity coefficient of backlight module, reduces the liquid crystal display displays quality.

Please refer to Fig. 3, Fig. 3 is the synoptic diagram of another LCD backlight module drive circuit 30 in the prior art.Backlight module drive circuit 30 uses balancing circuitry (Balance Circuit) to improve the shortcoming of lamp current inequality when driving many fluorescent tubes, explains with two fluorescent tubes in Fig. 3.Backlight module drive circuit 30 comprises a transformer TR and a balancing circuitry 32, can drive fluorescent tube L1 and L2, and the electric current by fluorescent tube L1 and L2 is respectively by I _L1And I _L2 Represent.Balancing circuitry 32 comprises transistor Qp and Qn, diode Dp and Dn, comparer 34, and active member such as impedor (Impedance) Cx.Because balancing circuitry 32 adopts active design, the back coupling signal V1 of its generation is relevant to electric current I _L1Value, be relevant to electric current I and feedback signal V2 _L2Value.Comparer 34 can relatively be feedback the difference between signal V1 and the V2, and exports a corresponding switching voltage signal Vsw according to this, switching voltage signal Vsw is reached the gate of transistor Qp and Qn again.The open and close of switching voltage signal Vsw may command transistor Qp and Qn utilize transistorized on/off switch to move and adjust electric current I _L2Size so that electric current I _L2Value be bordering on electric current I _L1To reach the purpose of lamp tube current balance.

The backlight module drive circuit 30 of prior art adopts active design, and feedbacks the comparison and correction of carrying out electric current by actual current, electric current can be adjusted to setting value, more is not subjected to factor affecting such as surrounding environment.Yet, in backlight module drive circuit 30, transistor Qp and Qn operate in the switch region, lamp current can be because the property difference of transistor itself (for example carrying out the speed of on/off switch action), cause each lamp tube current waveform may have asymmetric positive-negative half-cycle waveform, unless be continuously applied a direct current level, the current waveform of lamp current also can produce distortion and shorten lamp tube service life.In addition, though backlight module drive circuit 30 adopts the actual current I that is relevant to fluorescent tube L2 _L2Back coupling signal V2 do control, but comparer 34 output signals can only be the logical signals of high-low level, so comparer 34 and can't judge electric current I exactly _L1And I _L2Between difference, and comparer 34 reaction velocitys are slower, need just can reach balance after after a while.In addition, balancing circuitry 32 can only be applied to the low-voltage end of fluorescent tube, and can't be applied to the high voltage end of fluorescent tube, so when large size panel adopts the both-end driving framework, and can't use backlight module drive circuit 30.

Summary of the invention

The invention provides a kind of signal regulation module, be used for adjusting the driving signal that one drive circuit exports the light-source generation device on the display panel to, it comprises one first suspension joint type current regulator, be coupled to one first light-source generation device on this driving circuit and this display panel, be used for adjusting the one first driving signal that this driving circuit exports this first light-source generation device to, and feedback signal in the optically-coupled mode according to one first and adjust this first value that drives signal, drive signal to export adjusted first; One first signal detecting device is coupled to this first suspension joint type current regulator, is used for producing corresponding first voltage signal in the optically-coupled mode according to this first value that drives signal; And one feedback controller, is coupled to this first signal detecting device and this first suspension joint type current regulator, is used for value according to this first voltage signal to produce this and first feedback signal, and this first is feedback signal and export this first suspension joint type current regulator to.

The present invention also provides a kind of display device that drives signal of adjusting, and it comprises a light-source generation device, is used for driving signal according to one light source is provided; One drive unit is used for producing this driving signal; And a signal adjusting gear, be used for coming this driving signal of sensing to produce corresponding back coupling signal in the optically-coupled mode, adjust the value of this driving signal according to this back coupling signal, and export adjusted driving signal to this light-source generation device.

Description of drawings

Fig. 1 is the synoptic diagram of a LCD backlight module drive circuit in the prior art.

Fig. 2 is the synoptic diagram of another LCD backlight module drive circuit in the prior art.

Fig. 3 is the synoptic diagram of another LCD backlight module drive circuit in the prior art.

Fig. 4 is the synoptic diagram of a LCD backlight module among the present invention.

Fig. 5 is the synoptic diagram of a LCD backlight module among the present invention.

Fig. 6 is the synoptic diagram of signal regulation module in the first embodiment of the invention.

Fig. 7 is the synoptic diagram of signal regulation module in the second embodiment of the invention.

The reference numeral explanation

32 balancing circuitrys, 34 comparers

44 single driver 46 single transformers

48 control chips, 52 fluorescent tube modules

60 signal regulation modules 62 are awarded controller

70 digitial controllers, 72 averaging circuits

C1 capacitor C x impedor

OP operational amplifier L, L1-Ln fluorescent tube

10,20,30,42 driving circuits

40,50 backlight modules

D1, Dp, Dn diode

Qp, Qn transistor

SW, SW1, SW2 switch

TR, TR1-TRn transformer

DIM, DIM1, DIM2 light modulator

PIC, PIC1, PIC2 proportional integral device

FCR, FCR1-FCRn suspension joint type current regulator

SS, SS1-SSn signal detecting device

PHC11, PHC12, PHC21, PHC22 optical coupling element

R, R1-R4, R11, R12, R21, R22 resistance

Embodiment

Please refer to Fig. 4, Fig. 4 is the synoptic diagram of a LCD backlight module 40 among the present invention.LCD backlight module 40 comprises one drive circuit 42, a signal regulation module 60 and a digitial controller 70, can drive a fluorescent tube module 52.Fluorescent tube module 52 can comprise a fluorescent tube or many fluorescent tubes, explain with fluorescent tube L1-Ln in Fig. 4, and the electric current by fluorescent tube L1-Ln is respectively by I _L1-I _Ln Represent.Driving circuit 42 comprises a single driver (Single Driver) 44, one single transformer (SingleTransformer) 46, and a control chip 48.Single driver 44 can convert the direct voltage source of input to alternating voltage, promotes the size of this alternating voltage again by single transformer 46, drives the required voltage of fluorescent tube module 52 in order to provide.Required relevant controlling signal when 48 of control chips provide LCD backlight module 40 running.

Signal regulation module 60 comprises suspension joint type current regulator (Floating CurrentRegulator) FCR1-FCRn, signal detecting device SS1-SSn, and a back coupling controller 62.Signal regulation module 60 detects the electric current I of passing through fluorescent tube L1-Ln by signal detecting device SS1-SSn respectively _L1-I _LnSize, and transmit corresponding back coupling signal V respectively by feedbacking controller 62 _Fb1-V _FbnTo suspension joint type current regulator FCR1-FCRn, suspension joint type current regulator FCR1-FCRn is more respectively according to feedbacking signal V _Fb1-V _FbnThe instant electric current I of adjusting _L1-I _LnValue.Signal regulation module 60 adopts active design, can make all can reach setting value by the electric current on the every fluorescent tube according to adjusting current value immediately by the actual current on the every fluorescent tube.Signal regulation module 60 and driving circuit 42 can be arranged at same printed circuit board (PCB) (Printed Circuit Board, PCB) on, or be arranged at respectively on two printed circuit board (PCB)s.Signal regulation module 60 can be the integrated circuit of a high-pressure process, and also the matrix current adjustment circuit of being made up of circuit component can be described in detail after the detailed structure of signal regulation module 60.

Digitial controller 70 can carry out various sequential and brilliance control at single or all fluorescent tubes, changes the effect that reaches image processing by changing brightness of backlight module.The system that at first accepts digitial controller 70 transmits the controlling signal V at image processing _IN, after its internal digital control integrated circuit processing, send signal V respectively corresponding to fluorescent tube L1-Ln _COM1-V _COMnImmediately regulate and control lighting tube brightness, make display frame can obtain best light source adjustment, make screen-picture more clear beautiful, the light and shade contrast is better obviously.Therefore, do not receive controlling signal V when backlight module 40 corresponding to image processing _INThe time, digitial controller 70 is according to the running of its inner setting value, and this moment, LCD backlight module 40 was carried out sharing control by signal regulation module 60, made each lamp tube current value of flowing through identical; When LCD backlight module 40 receives controlling signal V corresponding to image processing _INThe time, this moment, backlight module 40 was carried out sharing control by signal regulation modules 60 earlier, made each lamp tube current value of flowing through identical, and digitial controller 70 is again according to controlling signal V _INExport corresponding signal V _COM1-V _COMn, reach the effect of image processing by the brightness of instant each fluorescent tube of regulation and control.Therefore, LCD backlight module 40 can reach the effect of sharing control and image processing simultaneously.

Please refer to Fig. 5, Fig. 5 is the synoptic diagram of another LCD backlight module 50 among the present invention.LCD backlight module 50 also comprises driving circuit 42, signal regulation module 60 and digitial controller 70, can drive fluorescent tube module 52.LCD backlight module 50 and LCD backlight module 40 differences are: the signal regulation module 60 of LCD backlight module 40 is coupled between the high voltage end of driving circuit 42 and fluorescent tube module 52, and the signal regulation module 60 of LCD backlight module 50 is coupled between the low-voltage end and earthing potential of fluorescent tube module 52.Because signal regulation module of the present invention 60 adopts the design of suspension joint types, that is carries out the height voltage isolation in the optically-coupled mode, so need not consider problems such as withstand voltage deficiency that high cross-pressure causes or safety concerns.Therefore, signal regulation module 60 can be located at the high voltage end of fluorescent tube module 52, LCD backlight module 40 as shown in Figure 4.Perhaps, signal regulation module 60 also can be located at the low-voltage end of fluorescent tube module 52, LCD backlight module 50 as shown in Figure 5.

Please refer to Fig. 6, Fig. 6 is the synoptic diagram of signal regulation module 60 in the first embodiment of the invention.The embodiment of Fig. 6, only explains with two fluorescent tubes at this in order to simplify narration for driving the structure of many fluorescent tubes.In first embodiment of the invention, fluorescent tube module 52 comprises two fluorescent tube L1 and L2, and the electric current by fluorescent tube L1 and L2 is respectively by I _L1And I _L2Represent.Signal regulation module 60 comprises suspension joint type current regulator FCR1 and FCR2, signal detecting device SS1 and SS2, and back coupling controller 62.In signal regulation module 60, each suspension joint type current regulator and signal detecting device respectively comprise elements such as optical coupling element (Photo Couple), impedor and resistance.The optical coupling element PHC12 of signal detecting device SS1 and SS2 and PHC22 can distinguish the electric current I of senses flow through fluorescent tube L1 and L2 _L1And I _L2, work as electric current I _L1And I _L2Big more, the electric current of the optical coupling element internal body diodes of flowing through is big more, so the optotransistor ON time of optical coupling element inside is just long more, so the electric current I of the optical coupling element inside of flowing through _PHC1And I _PHC2Just big more.Simultaneously, can be by resistance R 12 and R22 respectively with current signal I _PHC1And I _PHC2Convert voltage level V to ₁And V ₂Therefore, the flow through electric current I of fluorescent tube L1 and L2 _L1And I _L2Big more, voltage level V ₁And V ₂Just high more; The flow through electric current I of fluorescent tube L1 and L2 _L1And I _L2More little, voltage level V ₁And V ₂Just low more.

In first embodiment of the invention shown in Figure 6, back coupling controller 62 comprises an averaging circuit (Averaging Circuit) 72, light modulator (Dimmer) DIM1 and DIM2, and proportional integral device (Proportional Integral Controller, PI Controller) PIC1 and PIC2.Averaging circuit 72 is coupled to signal detecting device SS1 and SS2, and its function is to produce an average signal V _AVGMake the reference potential of proportional integral device PIC1 and PIC2, carry out the closed loop control of electric current in order to proportional integral device PIC1 and PIC2.Because fluorescent tube properties influence, understand difference behind the lamp tube starting because of itself characteristic, cause every lamp current difference, first embodiment of the invention utilizes averaging circuit 72 to get the mean value of all lamp currents, when system reaches balance, the size of current that every lamp tube current naturally will convergence sets, and then reach the current-sharing effect.In first embodiment of the invention, averaging circuit 72 comprises elements such as operational amplifier OP and resistance R, can reach the purpose that signal is isolated, and avoids being subjected to load effect to influence and causes averaging circuit 72 to produce mistake.

If fluorescent tube module 52 comprises fluorescent tube L1-Ln, the running of averaging circuit 72 can be represented by following formula:

$\frac{V_1-V_{\mathrm{AVG}}}{R}=\frac{V_{\mathrm{AVG}}-V_2}{R}+\frac{V_{\mathrm{AVG}}-V_3}{R}+\frac{V_{\mathrm{AVG}}-V_4}{R}+\·\·\·+\frac{V_{\mathrm{AVG}}-V_n}{R}$

Can get after the arrangement:

$V_{\mathrm{AVG}}=\frac{V_1+V_2+\·\·\·+V_n}{n}$

Therefore, when fluorescent tube module 52 comprised fluorescent tube L1 and L2, the running of averaging circuit 72 can be represented by following formula in the first embodiment of the invention:

$V_{\mathrm{AVG}}=\frac{{\mathrm{<figure-callout\; id="1"\; label="V"\; filenames="C200610141216E00181.png"\; state="\{\{state\}\}">V</figure-callout>}}_1+V_2}{2}$

If the user needs to adjust its brightness at each fluorescent tube in the light tube group 52 individually, can import controlling signal V by system _INTo digitial controller 70, digitial controller 70 produces according to this corresponding to the reference signal of adjusting each fluorescent tube again.In first embodiment of the invention, when the user desired distinctly to adjust the brightness of fluorescent tube L1 and L2, digitial controller 70 can produce corresponding reference signal V respectively _COM1And V _COM2

Light modulator DIM1 and DIM2 can receive by the image controlling signal of system end after calculation process, or receive the controlling signal V that is sent by digitial controller 70 respectively _COM1And V _COM2, and by switch SW 1 and SW2 the signal that receives is reached proportional integral device PIC1 and PIC2 respectively.In first embodiment of the invention, light modulator DIM1 and DIM2 respectively comprise a resistance R 4 and a diode D1, but the different output voltage of mat is controlled different current waveforms, increase the elasticity of circuit design.

Proportional integral device PIC1 and PIC2 respectively comprise operational amplifier OP, resistance R 1-R3 and capacitor C 1.The positive input terminal of proportional integral device PIC1 and PIC2 is coupled to averaging circuit 72 to receive average signal V _AVG, negative input end is respectively coupled to signal detecting device SS1 and SS2 to receive voltage V respectively ₁And V ₂, and output terminal is respectively coupled to suspension joint type current regulator FCR1 and FCR2.Proportional integral device PIC1 is according to average signal V _AVGWith voltage V ₁Produce back coupling signal V in its output terminal _Fb1, and will feedback signal V _Fb1Reach the optical coupling element PHC11 of suspension joint type current regulator FCR1.In like manner, proportional integral device PIC2 is according to average signal V _AVGWith voltage V ₂Produce back coupling signal V in its output terminal _Fb2, and will feedback signal V _Fb2Reach the optical coupling element PHC21 of suspension joint type current regulator FCR2.

The effect of suspension joint type current regulator FCR1 and FCR2 is to carry out the adjustment of lamp current size, utilizes the interior lights coupling diode to regulate and control the lamp current size.FCR1 is an example with suspension joint type current regulator, when feedbacking signal V _Fb1When becoming big, the electric current of flow through its optically-coupled diode and resistance R 11 is also big more, so its inner optotransistor ON time is just long more, the electric current I on the fluorescent tube L1 that flows through _L1Also can become big; Anti-, when feedbacking signal V _Fb1When diminishing, the electric current of flow through its optically-coupled diode and resistance R 11 is also more little, so its inner optotransistor ON time is just short more, the electric current I on the fluorescent tube L1 that flows through _L1Also can diminish.In addition, impedor Z11 and Z21 can comprise elements such as diode or electric capacity, its role is to provide interchange sinusoidal signal another flow to the path.

According to different designs, can be coupled to positive input terminal or the negative input end of proportional integral device PIC1 and PIC2 respectively by switch SW 1 and SW2 as light modulator DIM1 and DIM2.When light modulator DIM1 and DIM2 were coupled to the negative input end of proportional integral device PIC1 and PIC2 by switch SW 1 and SW2 respectively, the back coupling signal of proportional integral device PIC1 and PIC2 output can be represented by following formula one: $V_{\mathrm{fb}}\left(t\right)=V_{\mathrm{AVG}}+\frac{R_3}{R_2}(V_{\mathrm{AVG}}-V_1)+\frac{1}{R_2{\mathrm{<figure-callout\; id="1"\; label="C"\; filenames="C200610141216E00181.png"\; state="\{\{state\}\}">C</figure-callout>}}_1}\underset{0}{\overset{\mathrm{\&tau;}}{\&Integral;}}(V_{\mathrm{AVG}}-V_1)\mathrm{dt}+\frac{R_3}{R_1}(V_{\mathrm{AVG}}-V_{\mathrm{COM}})+\frac{1}{R_1{\mathrm{<figure-callout\; id="1"\; label="C"\; filenames="C200610141216E00181.png"\; state="\{\{state\}\}">C</figure-callout>}}_1}\underset{0}{\overset{\mathrm{\&tau;}}{\&Integral;}}(V_{\mathrm{AVG}}-V_{\mathrm{COM}})\mathrm{dt}$ If resistance R 3 is 0 ohm, then proportional integral device PIC1 and PIC2 can be considered as integrator (IController), this moment, the back coupling signal of proportional integral device PIC1 and PIC2 output can be represented by following formula two:

$V_{\mathrm{fb}}\left(t\right)=V_{\mathrm{AVG}}+\frac{1}{R_2{\mathrm{<figure-callout\; id="1"\; label="C"\; filenames="C200610141216E00181.png"\; state="\{\{state\}\}">C</figure-callout>}}_1}\underset{0}{\overset{\mathrm{\&tau;}}{\&Integral;}}(V_{\mathrm{AVG}}-V_1)\mathrm{dt}+\frac{1}{R_1{\mathrm{<figure-callout\; id="1"\; label="C"\; filenames="C200610141216E00181.png"\; state="\{\{state\}\}">C</figure-callout>}}_1}\underset{0}{\overset{\mathrm{\&tau;}}{\&Integral;}}(V_{\mathrm{AVG}}-V_{\mathrm{com}})\mathrm{dt}$

At the purpose of electric current current-sharing the time, do not consider earlier controlling signal V _COM, by formula one or formula two as can be known, voltage V ₁Must equal average signal V _AVG, back coupling signal V _FbVoltage just can be fixed up.Therefore, back coupling signal V _Fb1And V _Fb2Can drive suspension joint type current regulator FCR1 and FCR2 respectively, so that the voltage V that corresponding signal detecting device SS1 and SS2 are produced ₁And V ₂Difference convergence back coupling signal V _Fb1And V _Fb2Value.So, each lamp tube current energy convergence one identical value of flowing through, and the current-sharing effect of acquisition light intensity unanimity.When the purpose of adjusting at image, controlling signal V _COMAlso need consider, except voltage V ₁And V ₂Outward, controlling signal V _COMAlso can influence the value of back coupling signal.Therefore by changing controlling signal V _COM1And V _COM2Value, can change voltage V respectively ₁And V ₂Convergence back coupling signal V _Fb1And V _Fb2End value.

Please refer to Fig. 7, Fig. 7 is the synoptic diagram of signal regulation module 60 in the second embodiment of the invention.The embodiment of Fig. 7 is for driving the structure of single fluorescent tube, so fluorescent tube module 52 only comprises a fluorescent tube L, and the electric current by fluorescent tube L is by I _LRepresent.In second embodiment of the invention, signal regulation module 60 comprises a suspension joint type current regulator FCR, a signal detecting device SS, and back coupling controller 62.Suspension joint type current regulator FCR and signal detecting device SS respectively comprise elements such as optical coupling element, impedor and resistance.Because the situation of current unevenness can't take place for driving the structure of single fluorescent tube in second embodiment of the invention.When the electric current I of the optical coupling element PHC12 of signal detecting device SS internal body diodes senses flow through fluorescent tube L _LAfter, its inner optotransistor can produce corresponding electric current I _PHC, again by resistance R 12 with current signal I _PHCConvert voltage level V to.

In second embodiment of the invention shown in Figure 7, back coupling controller 62 comprises an averaging circuit 72, a light modulator DIM, and a proportional integral device PIC.Owing to drive the structure of single fluorescent tube one group of voltage V is only arranged ₁, voltage V ₁Can reach proportional integral device PIC by averaging circuit 72.If user's desire is adjusted the brightness of fluorescent tube L, can import controlling signal V by system _INTo digitial controller 70, digitial controller 70 produces according to this corresponding to the reference signal V that adjusts fluorescent tube L again _COM, reference signal V _COMCan reach proportional integral device PIC by switch SW.

According to different designs, can be coupled to positive input terminal or the negative input end of proportional integral device PIC as light modulator DIM by switch SW.When light modulator DIM is coupled to the negative input end of proportional integral device PIC by switch SW, the back coupling signal V of proportional integral device PIC output _FbCan represent by following formula three:

$V_{\mathrm{fb}}\left(t\right)={\mathrm{<figure-callout\; id="1"\; label="V"\; filenames="C200610141216E00181.png"\; state="\{\{state\}\}">V</figure-callout>}}_1+\frac{R_3}{R_1}(V_1-V_{\mathrm{COM}})+\frac{1}{R_1{\mathrm{<figure-callout\; id="1"\; label="C"\; filenames="C200610141216E00181.png"\; state="\{\{state\}\}">C</figure-callout>}}_1}\underset{0}{\overset{\mathrm{\&tau;}}{\&Integral;}}(V_1-V_{\mathrm{COM}})\mathrm{dt}$

If resistance R 3 is 0 ohm, then proportional integral device PIC1 and PIC2 can be considered integrator, the back coupling signal V of proportional integral device PIC output this moment _FbCan represent by following formula four::

$V_{\mathrm{fb}}\left(t\right)={\mathrm{<figure-callout\; id="1"\; label="V"\; filenames="C200610141216E00181.png"\; state="\{\{state\}\}">V</figure-callout>}}_1+\frac{1}{R_1{\mathrm{<figure-callout\; id="1"\; label="C"\; filenames="C200610141216E00181.png"\; state="\{\{state\}\}">C</figure-callout>}}_1}\underset{0}{\overset{\mathrm{\&tau;}}{\&Integral;}}(V_1-V_{\mathrm{COM}})\mathrm{dt}$

The purpose of adjusting at image, by formula three or formula four as can be known, voltage V ₁Must equal controlling signal V _COM, back coupling signal V _FbVoltage just can be fixed up.Therefore feedback signal V _FbCan drive suspension joint type current regulator FCR, so that the voltage V that signal detecting device SS is produced ₁Convergence controlling signal V _COMValue.Therefore by changing controlling signal V _COMValue, can change voltage V ₁Convergence controlling signal V _COMEnd value, to reach the purpose that image is adjusted.

The present invention can be applicable in the LCD of various different frameworks, when driving many fluorescent tubes, can improve the unbalanced phenomenon of lamp current, solves the not good problem of backlight module uniformity coefficient.Simultaneously, the present invention also can do lamp tube starting sequential, size of current adjustment by the various controlling signal of digitial controller, reaches various controls such as brightness adjustment, to reach functions such as picture control and image processing.

The above only is preferred embodiment of the present invention, and all equalizations of doing according to claim of the present invention change and modify, and all should belong to covering scope of the present invention.

Claims (31)

1. a signal regulation module is used for adjusting the driving signal that one drive circuit exports the light-source generation device on the display panel to, and it comprises:

One first suspension joint type current regulator, be coupled to one first light-source generation device on this driving circuit and this display panel, be used for adjusting the one first driving signal that this driving circuit exports this first light-source generation device to, and feedback signal in the optically-coupled mode according to one first and adjust this first value that drives signal, drive signal to export adjusted first;

One first signal detecting device is coupled to this first suspension joint type current regulator, is used for producing corresponding first voltage signal in the optically-coupled mode according to this first value that drives signal from this first suspension joint type current regulator output; And

One back coupling controller is coupled to this first signal detecting device and this first suspension joint type current regulator, is used for producing this first back coupling signal according to the value of this first voltage signal, and exports this first back coupling signal to this first suspension joint type current regulator.

2. signal regulation module as claimed in claim 1, it also comprises:

One digitial controller, be coupled to this back coupling controller, be used for exporting one and feedback controller to this, first feedback signal so that this back coupling controller produces this according to this first voltage signal and this first reference signal corresponding to first reference signal of this first light-source generation device display characteristic.

3. signal regulation module as claimed in claim 2, wherein this back coupling controller comprises:

One proportional integral device is coupled to this first suspension joint type current regulator, this first signal detecting device and this digitial controller, is used for adjusting the value of this first voltage signal according to this first reference signal, and produces this first back coupling signal.

4. signal regulation module as claimed in claim 3, wherein this proportional integral device comprises:

One adjusts circuit, is coupled to this first signal detecting device and this digitial controller, is used for receiving and adjusting this first voltage signal and this first reference signal; And

One operational amplifier, it comprises:

One first input end is coupled to this adjustment circuit, is used for receiving through adjusted this first voltage signal of this adjustment circuit;

One second input end is coupled to this adjustment circuit, is used for receiving through adjusted this first reference signal of this adjustment circuit; And

One output terminal is used for exporting this first back coupling signal.

5. signal regulation module as claimed in claim 4, wherein this adjustment circuit comprises a passive device, and this passive device comprises resistance and electric capacity.

6. signal regulation module as claimed in claim 3, wherein this back coupling controller also comprises:

One light modulator is coupled between this digitial controller and this proportional integral device, is used for controlling the circulation path of this first reference signal.

7. signal regulation module as claimed in claim 6, wherein this light modulator comprises a resistance and a diode.

8. signal regulation module as claimed in claim 1, it also comprises:

One second suspension joint type current regulator, be coupled to the secondary light source generation device on this driving circuit and this display panel, be used for adjusting the one second driving signal that this driving circuit exports this secondary light source generation device to, and feedback signal in the optically-coupled mode according to one second and adjust this second value that drives signal, drive signal to export adjusted second; And

One second signal detecting device, be coupled to this second suspension joint type current regulator and this backs coupling controller, be used for producing corresponding second voltage signal according to value and feedback controller to this from this second driving signal of this second suspension joint type current regulator output in the optically-coupled mode;

Wherein, this back coupling controller produces this first and second back couplings signal according to the mean value of this first and second voltage signal, and exports this first and second back couplings signal to this first and second suspension joints type current regulator respectively.

9. signal regulation module as claimed in claim 8, wherein this back coupling controller comprises:

One averaging circuit is coupled to this first and second signals detecting device, is used for receiving this first and second voltage signal and produces an average signal corresponding to the mean value of this first and second voltage signal.

10. signal regulation module as claimed in claim 9, wherein this averaging circuit comprises an operational amplifier.

11. signal regulation module as claimed in claim 9, it also comprises:

One digitial controller, be coupled to this back coupling controller, be used for exporting corresponding to first and second reference signal of this first and second light-source generation device display characteristic and feedback controller to this, so that this back coupling controller produces this first back coupling signal according to this average signal and this first reference signal, and produce this second back coupling signal according to this average signal and this second reference signal.

12. signal regulation module as claimed in claim 11, wherein this back coupling controller also comprises:

One first proportional integral device is coupled to this first suspension joint type current regulator and this averaging circuit, is used for producing this first back coupling signal according to this average signal and this first reference signal; And

One second proportional integral device is coupled to this second suspension joint type current regulator and this averaging circuit, is used for producing this second back coupling signal according to this average signal and this second reference signal.

13. signal regulation module as claimed in claim 12, wherein:

This first proportional integral device comprises:

One first adjusts circuit, is coupled to this averaging circuit and this digitial controller, is used for receiving and this average signal of adjustment and this first reference signal; And

One first operational amplifier, it comprises:

One first input end is coupled to this first adjustment circuit, is used for receiving through adjusted this average signal of this first adjustment circuit;

One second input end is coupled to this first adjustment circuit, is used for receiving through adjusted this first reference signal of this first adjustment circuit; And

One output terminal is used for exporting this first back coupling signal; And

This second proportional integral device comprises:

One second adjusts circuit, is coupled to this averaging circuit and this digitial controller, is used for receiving and this average signal of adjustment and this second reference signal; And

One second operational amplifier, it comprises:

One first input end is coupled to this second adjustment circuit, is used for receiving through adjusted this average signal of this second adjustment circuit;

One second input end is coupled to this second adjustment circuit, is used for receiving through adjusted this second reference signal of this second adjustment circuit; And

One output terminal is used for exporting this second back coupling signal.

14. signal regulation module as claimed in claim 13, wherein each adjustment circuit comprises a passive device, and this passive device comprises resistance and electric capacity.

15. signal regulation module as claimed in claim 12, wherein this back coupling controller also comprises:

One first light modulator is coupled between this digitial controller and this first proportional integral device, is used for controlling the circulation path of this first reference signal; And

One second light modulator is coupled between this digitial controller and this second proportional integral device, is used for controlling the circulation path of this second reference signal.

16. signal regulation module as claimed in claim 15, wherein each light modulator comprises a resistance and a diode.

17. signal regulation module as claimed in claim 1, wherein this first suspension joint type current regulator comprises:

One optically-coupled diode is coupled to this back coupling controller to receive this first back coupling signal, is used for providing light source according to the forward current of this optically-coupled diode of flowing through, and wherein the forward current of this optically-coupled diode is relevant to the value of this first back coupling signal; And

One photo-coupled transistor, be coupled to this driving circuit and this first light-source generation device, be used for adjusting from the value of this first driving signal of this driving circuit output, and produce corresponding this adjusted first driving signal according to the intensity of light source that this optically-coupled diode is provided.

18. signal regulation module as claimed in claim 17, wherein this first suspension joint type current regulator also comprises an impedor, is parallel to this photo-coupled transistor.

19. signal regulation module as claimed in claim 18, wherein this impedor is a diode or an electric capacity.

20. signal regulation module as claimed in claim 1, wherein this first signal detecting device comprises:

One optically-coupled diode, be coupled to this first suspension joint type current regulator to receive this first driving signal from this first suspension joint type current regulator output, be used for providing light source according to the forward current of this optically-coupled diode of flowing through, wherein the forward current of this optically-coupled diode is relevant to the value that first of this first suspension joint type current regulator output drives signal; And

One photo-coupled transistor is coupled to this back coupling controller, is used for producing corresponding this first voltage signal according to the intensity of light source that this optically-coupled diode is provided.

21. signal regulation module as claimed in claim 20, wherein this first signal detecting device comprises an impedor, is parallel to this optically-coupled diode.

22. signal regulation module as claimed in claim 21, wherein this impedor is a diode or an electric capacity.

23. signal regulation module as claimed in claim 1, it is to be coupled between the high voltage end of this driving circuit and this light-source generation device.

24. signal regulation module as claimed in claim 1, it is coupled between the low-voltage end and earthing potential of this light-source generation device.

25. can adjust the display device that drives signal for one kind, it comprises:

One light-source generation device is used for driving signal according to one light source is provided;

One drive unit is used for producing this driving signal; And

One signal adjusting gear is used for coming this driving signal of sensing to produce corresponding back coupling signal in the optically-coupled mode, and adjust the value of this driving signal according to this back coupling signal, and export adjusted driving signal to this light-source generation device,

Wherein, this signal adjusting gear comprises:

One suspension joint type current regulator is coupled to this drive unit and this light-source generation device, is used for adjusting the driving signal that this drive unit produces, and adjusts the value of this driving signal in the optically-coupled mode according to this back coupling signal, to export adjusted driving signal;

One signal detecting device is coupled to this suspension joint type current regulator, is used for producing a corresponding voltage signal in the optically-coupled mode according to the value from this driving signal of this suspension joint type current regulator output; And

One feedbacks controller, is coupled to this signal detecting device and this suspension joint type current regulator, is used for producing this back coupling signal according to the value of this voltage signal, and should feedbacks signal and export this suspension joint type current regulator to.

26. display device as claimed in claim 25, wherein this drive unit comprises a single driver, a control chip, and a transformer.

27. display device as claimed in claim 25, it also comprises a signal intensifying device, is used for strengthening this driving signal.

28. display device as claimed in claim 27, wherein this signal intensifying device comprises electric capacity.

29. display device as claimed in claim 25, it also comprises a numerical control device, be used for producing a reference signal that is relevant to this light-source generation device display characteristic, so that this signal adjusting gear is adjusted the value of this driving signal according to this back coupling signal and this reference signal.

30. display device as claimed in claim 25, wherein this drive unit and this signal adjusting gear are arranged on the same printed circuit board (PCB).

31. display device as claimed in claim 25, wherein this drive unit and this signal adjusting gear are arranged at respectively on two printed circuit board (PCB)s.

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