CN100574550C

CN100574550C - Multi-lamp-tube driving system

Info

Publication number: CN100574550C
Application number: CNB2005100327353A
Authority: CN
Inventors: 李启雄; 赵育孝; 范姜哲辰; 蔡正爵; 林宪男
Original assignee: Hongfujin Precision Industry Shenzhen Co Ltd; Hon Hai Precision Industry Co Ltd
Current assignee: Hongfujin Precision Industry Shenzhen Co Ltd; Hon Hai Precision Industry Co Ltd
Priority date: 2005-01-06
Filing date: 2005-01-06
Publication date: 2009-12-23
Anticipated expiration: 2025-01-06
Also published as: CN1802064A

Abstract

A kind of multi-lamp-tube driving system is used to drive a fluorescent tube module that comprises a plurality of fluorescent tubes.This multi-lamp-tube driving system comprises that one is converted to the transducer of direct voltage with input voltage, one is converted to the drive circuit of alternating voltage with direct voltage, one is electrically connected on the Pwm controller between fluorescent tube module and the transducer, is used for the output voltage according to the signal controlling transducer of fluorescent tube module feedback; One is electrically connected on the bus control unit between fluorescent tube module and the drive circuit, is used for adjusting operating frequency according to the signal of fluorescent tube module feedback the voltage output of control Driver Circuit.Multi-lamp-tube driving system provided by the invention only adopts a Pwm controller, and system architecture is simple, and effectively reduces cost.

Description

Multi-lamp-tube driving system

[technical field]

The present invention relates to a kind of multi-load drive system, refer to a kind of LCD (liquid crystal display, LCD) drive system of fluorescent tube more than the backlight module of being applied to especially.

[background technology]

Discharge lamp (discharge lamp) is usually used in the backlight of LCD panel, and it has according to state at that time and puts on the frequency of AC signal of fluorescent tube and the end-point voltage characteristic that changes.Discharge lamp has negative resistance character, and its equiva lent impedance can reduce along with the increase of input power.Power supply/power to the circuit of fluorescent tube must have a controllable interchange source of supply, and the feedback circuit that can accurately detect electric current in the fluorescent tube, so that the stability of holding circuit, and have the function that load is adjusted.

The system of a plurality of discharge lamps of driving of the prior art uses two Pwm controllers usually, and one is used to regulate the size of current of discharge lamp of flowing through, a direct voltage that is used for stablizing input driving circuit.

See also Fig. 1, it is the lamp-tube driving system that adopts in the known techniques.This lamp-tube driving system comprises a transducer 1, a bridge drive circuit 2, a fluorescent tube module 3, a Pwm controller 4 and a bridge controller 5.Wherein, Pwm controller 4 is used for according to the voltage after the transducer conversion by pulse width modulation control transformation device, thus the stable direct voltage of exporting.Bridge controller 5 also is a Pwm controller, is used for reaching the power of regulating flowing through lamps tube module electric current according to the electric current of flowing through lamps tube module.This lamp-tube driving system adopts two pulse modulation controllers, a direct voltage that is used for stablizing after transducer is changed, and another is used for regulating each lamp tube current of flowing through lamps tube module.Yet the cost of pulse modulation controller is higher, especially when driving many group fluorescent tubes, and the driving system structure complexity, and adopt a plurality of pulse modulation controllers to cause the cost costliness of whole lamp-tube driving system.

Thereby one of needs are applied to LCD, and (it is simple in structure, and low price for liquid crystal display, the LCD) drive system of fluorescent tube more than the backlight module.

[summary of the invention]

Technical problem to be solved by this invention is to provide a kind of multi-lamp-tube driving system, and it only adopts a Pwm controller.

For solving the problems of the technologies described above, a kind of multi-lamp-tube driving system provided by the invention is used to drive a light tube group module that comprises a plurality of fluorescent tubes.This multi-lamp-tube driving system comprises that one is converted to the transducer of direct voltage with input voltage, one is converted to the drive circuit of alternating voltage with direct voltage, one is electrically connected on the Pwm controller between fluorescent tube module and the transducer, is used for the output voltage according to the signal controlling transducer of fluorescent tube module feedback; One is electrically connected on the bus control unit between fluorescent tube module and the drive circuit, is used for adjusting operating frequency, control Driver Circuit according to the signal of fluorescent tube module feedback.

Because system of the present invention only adopts a Pwm controller, especially under the situation that drives many group fluorescent tubes, at utmost reduce the utilization rate of Pwm controller, so system configuration is simple, and effectively reduce cost.

[description of drawings]

Fig. 1 is known multi-lamp-tube driving system Organization Chart.

Fig. 2 is the Organization Chart of multi-lamp-tube driving system first embodiment of the present invention.

Fig. 3 is the Organization Chart of multi-lamp-tube driving system second embodiment of the present invention.

Fig. 4 is the Organization Chart of multi-lamp-tube driving system the 3rd embodiment of the present invention.

Fig. 5 is the Organization Chart of multi-lamp-tube driving system the 4th embodiment of the present invention.

[embodiment]

Consult Fig. 2, be depicted as the Organization Chart of multi-lamp-tube driving system first embodiment of the present invention.

In the present invention, multi-lamp-tube driving system comprises an AC/DC converter 11, one drive circuit 12, one fluorescent tube modules 13, one Pwm controllers 14, and a bus control unit (BUS Inverter Controller) 15.Wherein, fluorescent tube module 13 comprises a plurality of fluorescent tubes.

AC/DC converter 11 is used to receive alternating voltage, and is converted into direct voltage.

Drive circuit 12 is electrically connected with AC/DC converter 11, is used for being converted to alternating voltage with receiving direct voltage.Drive circuit 12 utilizes switch voltage when conducting to pass through, and the intransitable principle of voltage is converted to alternating voltage with the direct voltage that receives when closing.When switch conduction, switch receives a direct current voltage and exports the signal of a high potential, and when switch cuts out, because direct voltage can't be exported the signal of an electronegative potential by switch, therefore, direct voltage by a switch with periodically conducting and closing property, is produced periodic pulse, and this periodic pulse promptly is the alternating voltage of exporting via drive circuit 12.

In an embodiment of the present invention, drive circuit 12 is semibridge system drive circuits, and in other embodiments of the invention, drive circuit 12 also can make the full-bridge type drive circuit, or push-pull driver circuit.

Fluorescent tube module 13 is electrically connected with drive circuit 12, is used to receive drive circuit 12 output AC voltages, lights each fluorescent tube.

Pwm controller 14 links to each other with fluorescent tube module 13 and AC/DC converter 11, is used for that each lamp tube current feedback signal output one of flowing through controls signal to AC/DC converter 11 according to fluorescent tube module 13.AC/DC converter 11 changes the power of its output dc voltage according to this control signal.The power of the direct voltage of AC/DC converter 11 outputs influences the brightness of each fluorescent tube in the fluorescent tube module 13 via drive circuit 12.Therefore, when the brightness of each fluorescent tube in the fluorescent tube module 13 need correct or change, promptly, when each lamp tube current of flowing through need be adjusted, AC/DC converter 11, drive circuit 12, fluorescent tube module 13 and Pwm controller 14 will form a loop, change the direct voltage of AC/DC converter 11 outputs by each lamp tube current in the circuit feedback fluorescent tube module, thereby control the brightness of each fluorescent tube in the fluorescent tube module 13.

Bus control unit 15 is electrically connected with fluorescent tube module 13 and drive circuit 12, is used for adjusting bus control unit 15 operating frequencies according to flow through each lamp tube current of fluorescent tube module 13, improves the ac output voltage of drive circuit 12.Each fluorescent tube is not lighted as yet in fluorescent tube module 13, fluorescent tube module 13 constitutes a loop with bus control unit 15 and drive circuit 12, sense by the loop that each fluorescent tube does not have electric current in the fluorescent tube module 13, bus control unit 15 is adjusted operating frequency, control Driver Circuit 12 improves the alternating voltage of output, lights each fluorescent tube in the fluorescent tube module 13.

Consult Fig. 3, be depicted as the Organization Chart of multi-lamp-tube driving system second embodiment of the present invention.The difference of this multi-lamp-tube driving system and first embodiment of the invention only limits to adopt AC/DC converter 11 in first embodiment, promptly this multi-lamp-tube driving system uses the alternating voltage input to drive many fluorescent tubes, and adopt DC-DC converter 11 ' in a second embodiment, promptly this multi-lamp-tube driving system adopts the direct voltage input to drive many fluorescent tubes.

Too many when the quantity that drives fluorescent tube, and drive circuit 12 be can't bear numerous fluorescent tube power demand the time, and the present invention provides another preferred embodiment that drives a plurality of fluorescent tube modules again.

Seeing also Fig. 4, is the Organization Chart that the present invention drives a plurality of fluorescent tube modules.This circuit comprises a plurality of AC/

DC converters

11,21 ..., N1, a plurality of

drive circuits

12,22 ..., N2, a plurality of

fluorescent tube modules

13,23 ..., N3,14 ', one bus control unit 15 of a leggy Pwm controller.

AC/DC converter N1 (N=2,3 ...), drive circuit N2 (N=2,3 ...) and fluorescent tube module N3 (N=2,3 ...) AC/DC converter 11, drive circuit 12 and fluorescent tube module 13 annexation unanimities described in annexation and Fig. 1.

Leggy Pwm controller 14 ' and AC/DC converter N1 (N=1,2 ...) and fluorescent tube module N3 (N=1,2 ...) be electrically connected.Bus control unit 15 and drive circuit N2 (N=1,2 ...) and fluorescent tube module N3 (N=1,2 ...) be electrically connected.

Leggy Pwm controller 14 ' outputs control signals to corresponding AC/DC converter N1 (N=1 according to pre-set sequential in the different time, 2 ...), control AC/DC converter N1 (N=1,2 ...) receive the alternating voltage input in the different time.

At first, leggy Pwm controller 14 ' control AC/DC converter 11 receives alternating voltages, and AC/DC converter 11 is converted to direct voltage with alternating voltage.Drive circuit 12 is converted to alternating voltage with direct voltage, is used to drive fluorescent tube module 13 each fluorescent tubes.The electric current of bus control unit 15 sense light tube modules 13 if do not have electric current in the fluorescent tube module 13, is then adjusted its operating frequency, improves the alternating voltage of drive circuit 12 outputs, thereby lights each fluorescent tube in the fluorescent tube module 13.

Each fluorescent tube is to finish in first time of leggy Pwm controller 14 ' sequential in the fluorescent tube module 13 if setting is lighted, then at the N (N=2 of leggy Pwm controller 14 ' sequential, 3, ...) in the time, leggy Pwm controller 14 ' control AC/DC converter N1 (N=2,3, ...) the reception alternating voltage, AC/DC converter N1 (N=2,3 ...) alternating voltage is converted to direct voltage.Drive circuit N2 is converted to alternating voltage with direct voltage, be used to drive fluorescent tube module N3 (N=2,3 ...) and each fluorescent tube.Do not have electric current to flow through if bus control unit 15 senses fluorescent tube module 23, then adjust operating frequency, improve drive circuit N2 (N=2,3 ...) and the alternating voltage of output, thereby light fluorescent tube module N3 (N=2,3 ...) and in each fluorescent tube.

When the brightness of each fluorescent tube among the fluorescent tube module N3 need correct or change, leggy Pwm controller 14 ' was controlled the direct voltage of AC/DC converter N1 output successively according to sequential, thereby regulated the brightness of each fluorescent tube among the fluorescent tube module N3.

Supposing to regulate fluorescent tube module 13 brightness finished in first time of leggy Pwm controller 14 ' sequential, then at the N (N=1 of leggy Pwm controller 14 ' sequential, 2, ...) in the individual time, AC/DC converter N1 (N=1,2 ...), drive circuit N2 (N=1,2 ...), fluorescent tube module N3 (N=1,2, ...) and leggy Pwm controller 14 ' will form a loop, by loop sense light tube module N3 (N=1,2, ...) in the feedback signal control AC/DC converter N1 (N=1 of each lamp current, 2 ...) direct voltage of output, thus reach control fluorescent tube module N3 (N=1,2 ...) in the purpose of brightness of each fluorescent tube.

Consult Fig. 5, be depicted as the Organization Chart of multi-lamp-tube driving system the 4th embodiment of the present invention.The circuit framework of this multi-lamp-tube driving system and third embodiment of the invention is basic identical, difference only limits to adopt among the 3rd embodiment AC/DC converter N1 ' (N=1,2, ...), promptly this multi-lamp-tube driving system can use the alternating voltage input to drive many fluorescent tubes, and in a second embodiment, adopt DC-DC converter N1 ' (N=1,2 ...), promptly this multi-lamp-tube driving system also can adopt the direct voltage input to drive many fluorescent tubes.

Claims

1. A multi-lamp driving system for driving a lamp module comprising a plurality of lamps, the multi-lamp driving system includes a converter for converting an input voltage into a DC voltage, and a converter for converting the DC voltage into an AC A voltage driving circuit, characterized in that the system further includes:

A pulse width modulation controller electrically connected between the lamp module and the converter, used to control the output voltage of the converter according to the signal fed back by the lamp module;

A bus controller electrically connected between the lamp module and the drive circuit, used to adjust the working frequency according to the signal fed back by the lamp module and control the drive circuit.

2. The multi-lamp driving system according to claim 1, wherein the converter is an AC/DC converter for converting the received AC voltage into a DC voltage.

3. The multi-lamp driving system according to claim 1, wherein the converter is a DC/DC converter for converting the received DC voltage into a DC voltage.

4. The multi-lamp driving system according to claim 1, wherein if the signal fed back by the lamp module is that no current flows through the lamp module, the bus controller controls the driving circuit to output an AC voltage.

5. The multi-lamp driving system according to claim 1, characterized in that the driving circuit is a half-bridge, full-bridge or push-pull type.

6. A multi-lamp driving system, used to drive a plurality of lamp modules including a plurality of lamps, the multi-lamp driving system includes a plurality of converters for converting an input voltage into a DC voltage, and a plurality of converters for converting the DC voltage Converting to an AC voltage drive circuit, characterized in that the system also includes:

A multi-phase pulse width modulation controller electrically connected between the plurality of lamp modules and the plurality of converters, controlling the output voltage of the converter according to the signals fed back by the plurality of lamp modules;

A bus controller electrically connected between a plurality of lamp modules and a plurality of drive circuits, used for adjusting the working frequency according to the signal fed back by the lamp modules, and controlling the drive circuits.

7. The multi-lamp driving system according to claim 6, wherein the converter is an AC/DC converter for converting the received AC voltage into a DC voltage.

8. The multi-lamp driving system according to claim 6, wherein the converter is a DC/DC converter for converting the received DC voltage into a DC voltage.

9. The multi-lamp driving system according to claim 6, wherein the multi-phase pulse width modulation controller outputs control signals to corresponding converters at different times according to its timing, and controls different converters at different times Accepts AC voltage input.

10. The multi-lamp driving system according to claim 6, wherein the multi-phase pulse width modulation controller sequentially controls the DC voltage output by different converters according to its timing, thereby adjusting the brightness of each corresponding lamp in the lamp module .

11. The multi-lamp driving system according to claim 6, wherein if the signal fed back by the lamp module is that no current flows through the lamp module, the bus controller increases the output AC voltage of the driving circuit by adjusting the operating frequency.

12. The multi-lamp driving system as claimed in claim 6, wherein the driving circuit is a half-bridge type, a full-bridge type or a push-pull type.