CN201369871Y

CN201369871Y - Back light source driving system and electronic equipment

Info

Publication number: CN201369871Y
Application number: CNU2009201299458U
Authority: CN
Inventors: 沈里和; 陈建宏
Original assignee: Huanyong Technology Co Ltd; Guolian Electronics (Shanghai) Co Ltd
Current assignee: Huanyong Technology Co Ltd; Guolian Electronics (Shanghai) Co Ltd
Priority date: 2009-02-20
Filing date: 2009-02-20
Publication date: 2009-12-23
Anticipated expiration: 2019-02-20

Abstract

The utility model provides a back light source driving system which is used for driving a plurality of lamp tube sets. The back light source driving system comprises a plurality of power supply converting circuits, a pulse width modulation controller and a plurality of multiplexers. The power supply converting circuits are correspondingly connected with the lamp tube sets, and are respectively used for providing AC signals to drive the corresponding lamp tube sets; the pulse width modulation controller is used for outputting a pulse width modulation control signal; each multiplexer is correspondingly connected with one power supply converting circuit, and receives as well as outputs the pulse width modulation control signal and low voltage signals to the corresponding power supply converting circuit according to the phase signal control which is externally input, so as to control whether the corresponding power supply converting circuit provides the AC signals to the corresponding lamp tube set. The utility model further provides electronic equipment. The electronic equipment and the back light source driving system can realize the alternate opening or closing by one pulse width modulation controller and a plurality of multiplexers; the cost is low and the controlling is simple.

Description

Backlight drive system and electronic equipment

Technical field

The utility model relates to a kind of electronic equipment, is meant a kind of backlight drive system especially and uses its electronic equipment.

Background technology

(Liquid Crystal Display, LCD) (Cold Cathode Fluorescent Lamp is CCFL) as the light source of (Backlight) backlight system with discharge lamp (Discharge Lamp), particularly cold-cathode fluorescence lamp for panel in liquid crystal display.Typically, cold-cathode fluorescence lamp is driven by converter circuit (InverterCircuit), and it can supply AC signal to fluorescent tube.

At relatively large display panels, in LCD TV, two or more cold-cathode fluorescence lamps need be set so that enough brightness to be provided.For a plurality of fluorescent tubes are changed in the light modulation process simultaneously, and cause display panels brightness acute variation, or display panels needs the scanning converter circuit when the show events picture, a kind of leggy discharge lamp driven apparatus all need be provided, make a plurality of fluorescent tube alternate.

Usually, the fluorescent tube in the large-scale display panels is divided into many groups by the zone, to realize alternation.Yet each light tube group need have a Pwm controller to control, and along with the increase of light tube group quantity, the quantity of Pwm controller also must increase, and this makes cost increase.

The utility model content

In view of this, need provide a kind of backlight drive system, but a plurality of light tube group of driven.

In addition, also need provide a kind of electronic equipment of using this backlight drive system.

A kind of backlight drive system is used to drive a plurality of light tube group, comprises a plurality of power-switching circuits, a Pwm controller and a plurality of multiplexer.The described light tube group of the corresponding connection of power-switching circuit, being respectively applied for provides AC signal to drive corresponding light tube group.Pwm controller is used to export a pulse width modulation control signal.The corresponding power-switching circuit that connects of multiplexer, each multiplexer all connects Pwm controller, received pulse width modulated control signal and low voltage signal, and according to the control of the phase signal of outside input, select output pulse width modulator control signal or low voltage signal to corresponding power-switching circuit, whether provide AC signal to corresponding light tube group to control corresponding power-switching circuit.

A kind of electronic equipment comprises operating circuit and LCD MODULE.Operating circuit is used to control the work of electronic equipment, and exports a plurality of phase signals.LCD MODULE comprises backlight and backlight drive system, and backlight comprises a plurality of light tube group.Backlight drive system comprises a plurality of power-switching circuits, Pwm controller and a plurality of multiplexer.The described light tube group of the corresponding connection of power-switching circuit, being respectively applied for provides AC signal to drive corresponding light tube group.Pwm controller is used for the output pulse width modulator control signal.The described power-switching circuit of the corresponding connection of multiplexer, each multiplexer all connects Pwm controller, received pulse width modulated control signal and low voltage signal, and according to the control of the phase signal of operating circuit output, select output pulse width modulator control signal or low voltage signal to corresponding power-switching circuit, whether provide described AC signal to corresponding light tube group to control corresponding power-switching circuit.

Above-mentioned electronic equipment and backlight drive system can be realized alternately opening or closing of light tube group by a Pwm controller and a plurality of multiplexer, thereby reach the effect of scanning, and cost is lower, and control is simpler.

Description of drawings

Fig. 1 is the Organization Chart of electronic equipment in the utility model one execution mode; And

Fig. 2 is the physical circuit Organization Chart of LCD MODULE in the utility model one execution mode.

Embodiment

About aforementioned and other technology contents, characteristics and effect of the present utility model, in the following detailed description that cooperates with reference to graphic execution mode, can clearly present.

Figure 1 shows that the Organization Chart of electronic equipment 10 in the utility model one execution mode.In the present embodiment, electronic equipment 10 comprises the equipment of big LCD for LCD TV or other, and it comprises operating circuit 20 and LCD MODULE 30.Operating circuit 20 is used to control the work of electronic equipment 10, and the signal that will handle is sent to LCD MODULE 30 and shows, and a plurality of phase signals of output.For example, if electronic equipment 10 is LCD TV, operating circuit 20 is used to handle image and voice signal, so that the LCD TV operate as normal, and the picture signal after will handling is sent to LCD MODULE 30 and shows.Described a plurality of phase signal phase places of operating circuit 20 outputs are not quite similar.

LCD MODULE 30 comprises backlight 40 and backlight drive system 50.Backlight 40 is used to LCD MODULE 30 to provide backlight, and backlight drive system 50 is used for the control according to the phase signal of operating circuit 20 outputs, drives backlight 40.The physical circuit framework of LCD MODULE 30 please refer to Fig. 2.

As shown in Figure 2, backlight 40 comprises a plurality of light tube group 400, and each light tube group 400 comprises a plurality of fluorescent tubes again.Backlight drive system 50 comprises a plurality of power-switching circuit 500, pulse width modulation (pulse width modulation, PWM) controller 510 and an a plurality of multiplexer 520.In the present embodiment, the quantity of phase signal, multiplexer 520, power-switching circuit 500 and the light tube group 400 of operating circuit 20 outputs is identical.

Power-switching circuit 500 light tube group 400 that connects one to one, being respectively applied for provides AC signal to drive corresponding light tube group 400.In the present embodiment, power-switching circuit 500 comprises switching circuit and transformer circuit etc.Pwm controller 510 is used to export a pulse width modulation control signal.

Multiplexer 520 power-switching circuit 500 that connects one to one, and each multiplexer 520 all connects Pwm controller 510, and reception low voltage signal and same pulse width modulation control signal, and according to the control of the phase signal of operating circuit 20 output, select output pulse width modulator control signal or low voltage signal to corresponding power-switching circuit 500, whether provide AC signal to corresponding light tube group 400 to control corresponding power-switching circuit 500.In the present embodiment, multiplexer 520 is the multiplexer switch, and each multiplexer 520 all comprises first input end 521, second input 522, control end 523 and output 524.First input end 521 connects Pwm controller 510, with the received pulse width modulated control signal.Second input 522 connects signal ground, to receive low voltage signal.Control end 523 receives a phase signal of operating circuit 20 inputs, and according to the current potential height of the phase signal that receives, the selectivity connection first input end 521 or second input 522 are to output 524, with the power-switching circuit 500 of output unlike signal to correspondence.In the present embodiment, the phase signal difference that the control end 523 of different multiplexers 520 receives receives first phase signal as first multiplexer 520, and second multiplexer 520 receives second phase signal, the rest may be inferred, and the phase place of these phase signals is not quite similar.

When the phase signal that receives when the control end 523 of certain multiplexer 520 is high potential, control end 523 control first input ends 521 connect output 524, thereby the output 524 output pulse width modulator control signals of multiplexer 520 are to corresponding power-switching circuit 500, make power-switching circuit 500 work, thereby drive corresponding light tube group 400, make it to light.

When the phase signal that receives when the control end 523 of certain multiplexer 520 is electronegative potential, control end 523 controls second input 522 connects output 524, thereby the extremely corresponding power-switching circuit 500 of the output 524 output LOW voltage signals of multiplexer 520, thereby make power-switching circuit 500 close light tube group 400.Because the phase signal phase place difference that a plurality of multiplexers 520 receive, thus make light tube group 400 alternately open or close, thus reach the effect of scanning.

Electronic equipment 10 of the present utility model is only by a Pwm controller 510, export a pulse width modulation control signal, and a plurality of multiplexers 520 can be realized the effect that light tube group 400 is alternately opened or closed, and because of having only a Pwm controller 510, make that the cost of electronic equipment 10 and backlight drive system 50 is lower, and control is simpler.

Claims

1. a backlight drive system is used to drive a plurality of light tube group, it is characterized in that, described backlight drive system comprises:

A plurality of power-switching circuits, the described light tube group of corresponding connection, being respectively applied for provides AC signal to drive corresponding light tube group;

A Pwm controller is used to export a pulse width modulation control signal; And

A plurality of multiplexers, the described power-switching circuit of corresponding connection, each multiplexer all connects described Pwm controller, receive described pulse width modulation control signal and low voltage signal, and according to the control of the phase signal of outside input, select described pulse width modulation control signal of output or described low voltage signal to corresponding power-switching circuit, provide the light tube group of described AC signal to described correspondence with the power-switching circuit of controlling described correspondence.

2. backlight drive system as claimed in claim 1, it is characterized in that, described multiplexer is the multiplexer switch, comprise at least two inputs, control end and output respectively, described two inputs receive described pulse width modulation control signal and low voltage signal respectively, and described control end receives the phase signal of described outside input.

3. backlight drive system as claimed in claim 2 is characterized in that, the phase signal phase place that described multiplexer receives is not quite similar.

4. backlight drive system as claimed in claim 2 is characterized in that, described control end is according to the current potential height of described phase signal, and selectivity connects described input to described output.

5. backlight drive system as claimed in claim 4, it is characterized in that, described control end is used for when described phase signal is high potential, control described pulse width modulation control signal input and connect described output, make described multiplexer export described pulse width modulation control signal, provide the light tube group of AC signal to described correspondence to drive the corresponding power change-over circuit.

6. an electronic equipment is characterized in that, comprising:

Operating circuit is used to control the work of described electronic equipment, and exports a plurality of phase signals; And

LCD MODULE comprises backlight and backlight drive system, and described backlight comprises a plurality of light tube group, and described backlight drive system comprises:

A Pwm controller is used to export a pulse width modulation control signal; And

A plurality of multiplexers, the described power-switching circuit of corresponding connection, each multiplexer all connects described Pwm controller, receive described pulse width modulation control signal and low voltage signal, and according to a phase signal of described operating circuit output control, select described pulse width modulation control signal of output or described low voltage signal to corresponding power-switching circuit, provide the light tube group of described AC signal to described correspondence with the power-switching circuit of controlling described correspondence.

7. electronic equipment as claimed in claim 6, it is characterized in that, described multiplexer is the multiplexer switch, comprise at least two inputs, control end and output respectively, described two inputs receive described pulse width modulation control signal and low voltage signal respectively, and described control end receives the phase signal of described operating circuit input.

8. electronic equipment as claimed in claim 7 is characterized in that, the described phase signal phase place of described operating circuit output is not quite similar.

9. electronic equipment as claimed in claim 7 is characterized in that, described control end is according to the current potential height of described phase signal, and selectivity connects described input to described output.

10. electronic equipment as claimed in claim 9, it is characterized in that, described control end is used for when described phase signal is high potential, control described pulse width modulation control signal input and connect described output, make described multiplexer export described pulse width modulation control signal, provide the light tube group of AC signal to described correspondence to drive the corresponding power change-over circuit.