TWI288278B - Multiple lamps backlight module - Google Patents

Abstract

A multiple lamps backlight module is provided. The multiple lamps backlight module comprises a plurality of first fluorescent lamps, a plurality of second fluorescent lamps, an electric source device, a first return cable, and a second return cable. Wherein each of the first fluorescent lamps has a first source electrode and a first feedback electrode, and each of the second fluorescent lamps has a second electric electrode and a second feedback electrode. In addition, the electric source device provides alternating currents with opposite phase to the first and the second source electrodes respectively. The first return cable is electrically connected between the first feedback electrode and the electric source device, and the second return cable is electrically connected between the second feedback electrode and the electric source device. The multiple lamps backlight module can provide precise feedback and compensation to improve the quality of output light and prevent the arc discharge owing to the high voltage between the return cables.

Description

Case No. 93109434 Year 1288278

V. INSTRUCTION DESCRIPTION OF THE INVENTION (1) [Technical Field to Be Invented by the Invention] In particular, the present invention relates to a multi-lamp backlight module having a feedback function of a backlight module. [Prior Art] With the development of the industry's daily surplus, digital devices such as mobile phones, digital cameras, history machines, notebook computers, and desktop computers are all in the direction of digital photography, multi-functionality and aesthetics. However, mobile phones, digital cameras, digital cameras, notebook computers, and desktop computers are indispensable for the human-machine communication interface. Through the above-mentioned products, the user's operation is more convenient. In recent years, large swollen mobile phones, digital cameras, digital cameras, and notebook computers have been used. The display screens on the computer are all liquid crystal display panels (LCD panes are on/off. However, since the liquid crystal display panels themselves do not have illumination The function can be, so the backlight module (elbow) must be provided under the LCD display panel to provide the surface light source required by the liquid crystal panel, so that the effect of the display can be obtained at the same time, and at the same time, it is sufficient. The function of the display. The degree of freedom and contrast, and then it is worth noting that the backlight module is usually divided into two types: the side-lit light-type fish type. ;r light guide pute), to convert the line source into the liquid crystal surface anti-s light source' and the direct-lit backlight module does not need to configure the light guide plate, V needs to directly provide the surface light source required by the liquid crystal panel, so #对对对对^ When there is a high demand for brightness, a direct-lit backlight module is usually used. The surface light source provided by the current backlight module is constructed in two ways, among which 1288278 is the number 93109434 _ Ά _ _ _ 5, the invention description (2) is composed of a plurality of cold cathode fluorescent lamps (Cold Cathode Fluorescent Lamp, CCFLs are arranged in parallel with each other, and the other method is arranged in an array by a plurality of Light Emitting Diodes. Please refer to FIG. 1 , which illustrates a schematic diagram of a conventional multi-lamp backlight module. The multi-lamp backlight module 100 includes a plurality of cold cathode fluorescent tubes, a power supply device 120 and a return line 1 30, wherein the power supply unit 12 is connected in series with all cold cathodes. The light tube 110 is provided to provide a driving current required for the cold cathode fluorescent lamp to emit light. In addition, the power supply device 120 further includes a DC to AC voltage converter 1 2 2 and a PWM control chip (PWM control 1C, hereinafter referred to as a PWM control chip) 124, wherein the DC to AC voltage is electrically connected to each other. The converter 1 2 2 can convert the DC power source into an AC power source to input the cold cathode fluorescent lamp 110, and the feedback line 1 30 is electrically connected to the feedback end of the cold fluorescent lamp 110. Between the PWM control chip 14 and the PWM control chip 124, a feedback signal is transmitted to the PWM control chip 124. Therefore, the PWM control chip 124 can immediately detect the tube current of the cold cathode fluorescent tube by using the feedback signal, and control the DC to the parent current voltage converter 1 2 2 to perform feedback compensation of the driving current. In order to maintain a stable output of the cold cathode fluorescent lamp 110. Referring to Figure 1, the early cold cathode fluorescent lamp is driven by the same phase AC power supply, but this driving method will cause signal interference to the L c D panel. In addition, when the feedback line 130 is released from the power supply device 120 by an external force, or an open circuit is formed between the feedback line i 3 〇 and the power supply device 1 2 0 due to an inaccurate product assembly, To the AC voltage converter 1 2 2 has a higher potential, which will cause the return line 1 130 and the surrounding low potential components

Page 10 1288278 Case No. 93109434 Revised V. Invention Description (3) An arc phenomenon that causes high-voltage discharge, which causes the component to burn out. Therefore, in order to improve the above situation, in recent years, the positive and negative polarities of the cold cathode fluorescent lamp have been alternately arranged to reduce the interference during display, and to avoid a high voltage between the feedback lines.

Please refer to FIG. 2, which illustrates a schematic diagram of another multi-lamp backlight module. The cold cathode fluorescent lamp 2 1 0 system can be divided into a plurality of first fluorescent tubes 21 2 and a plurality of second fluorescent tubes 214 in a interposed configuration, wherein the power supply device 2 2 0 outputs positive and negative polarities respectively ( The alternating current power source drives the first fluorescent tube 21 2 and the second fluorescent tube 214 to generate positive and negative opposite directions in the first fluorescent tube 21 2 and the second fluorescent tube 21 4, respectively. Tube current. Therefore, the interference phenomenon of the cold cathode fluorescent lamp 2 10 in display can be effectively reduced, and the generation of the high voltage can be avoided by the offset of the positive and negative currents.

In view of the above, although the above-mentioned arrangement of the lamps is staggered, the interference can be effectively reduced and high voltage is avoided. However, when the number of the first fluorescent tube and the second fluorescent tube are equal, the feedback from the tube will be The positive and negative currents of the terminal output cancel each other out, and the total feedback current is zero or only the difference between the positive and negative tube currents. In this way, the feedback device (such as the PWM control chip) will not be able to accurately detect or resolve the actual current value of the lamp to adjust the lamp current, thus affecting the uniformity of the output brightness of the backlight module. In addition, although the backlight module currently provides a feedback line for each lamp tube to perform feedback compensation for each lamp tube, such a wiring method is bound to greatly increase the number of feedback lines, thereby improving The cost of production. SUMMARY OF THE INVENTION In view of the above, the object of the present invention is to provide a multi-lamp backlight

Page 11 1288278 Case No. 93109434 Year Month Amendment 5, Invention Description (4) Module, which can greatly reduce the number of return lines, and can achieve the purpose of feedback and control of tube current, thus providing better light output quality. Another object of the present invention is to provide a multi-lamp backlight module that provides a protection circuit to avoid the arcing of the high voltage discharge of the feedback line to improve the reliability and safety of the product. Another object of the present invention is to provide a multi-lamp backlight module that provides a protection circuit to integrate different feedback signals and reduce the number of feedback lines, thereby reducing manufacturing costs.

Based on the above object, the present invention provides a multi-lamp backlight module, which includes, for example, a plurality of first fluorescent tubes, a plurality of second fluorescent tubes, a power supply device, and a first back The line and a second return line. Each of the first fluorescent tubes has a first power supply end and a corresponding one of the first feedback terminals, and each of the second fluorescent tubes has a second power supply end and a corresponding second one. The first fluorescent tube and the second fluorescent tube are parallel to each other and are interposed and interposed. In addition, the power supply unit supplies AC power of opposite phases to the first power supply terminal and the second power supply terminal, respectively. In addition, the first feedback line is electrically connected between the first feedback terminal and the power supply device, and the second feedback wire is electrically connected between the second feedback terminal and the power supply device.

Based on the above object, the present invention further provides another multi-lamp backlight module, which includes, for example, a plurality of first fluorescent tubes, a plurality of second fluorescent tubes, a power supply device, and a plurality of The first feedback line and the plurality of second feedback lines. Each of the first fluorescent tubes has, for example, a first power terminal and a corresponding one of the first feedback terminals, and each of the second fluorescent tubes has, for example,

Page 12 1288278 Case No. 93109434 V. Description of invention (5)

The correction has a second power supply end and a corresponding one of the second tube and the second fluorescent tube system are parallel to each other, and ===, and the other one of the fluorescent lamp power supply units is respectively provided for the opposite phase. In addition, the second power supply end ..., the first return line power supply; and the power supply device, and each of the first fluorescent light does not correspond to one of the end lines of the electrical connection, and the second system / The first one of the second feedback lines corresponds to the electrical connection brother 1//the light official department and X Λ* T N> 9 5 U> ο In a preferred embodiment of the invention, the juice is - a = M= 2. One of the voltage output units is electrically connected to each other, and the device includes, for example, a medium voltage output unit and a first power supply terminal to feed back the control unit 70, and the feedback control unit and the first feedback source 2 The terminal is electrically connected. In addition, the voltage output unit includes, for example, a DC-AC inverter, and feedback control to the AC voltage control control chip (PWM control 1C). 70, for example, including pulse width modulation. In a preferred embodiment of the present invention, the upper portion further includes at least a protection circuit, which is between the second feedback lines of the multi-lamp backlight module, and the protection circuit is connected. The first return line and the type of capacitance. In addition, the protection circuit can also be a comb capacitor or the like—the first diode, the second resistor, and the first resistor and the resistor are electrically connected to the first feedback line and the diode. The first resistor is connected between the second feedback line and the ground, and the second resistor is electrically connected between the first feedback line and the power supply device, and the one-pole system is electrically connected to the second feedback line and the power supply device. between. One-pole system electrical connection

Wm sms Page 13 1288278 Case No. 93109434 V. Description of the invention (6) The module is further electrically connected to the first end, for example, based on the driving voltage of the above-mentioned bit, and connected to the same group, and the return line In order to check the voltage feedback and the cost of the lamp backlight module, the quality of the light can be output. In addition, there is a pressure difference, so this road, which consists of the components of the maintenance segment. When forming an open circuit, the signal of the product is reduced, and the return is made to make the present invention easy to understand. The following is explained below. [Embodiment] The 曰 曰 曰 第三 第三 第三 第三 第三 第三 第三 第三 第三 第三 第三 第三 第三 第三 第三 第三 第三 第三 第三 第三 第三 第三 第三 第三 第三 第三 第三 第三 第三 第三 第三 第三 第三 第三 第三 第三 第三 第三 第三 第三 第三The multi-protection circuit can be combed to thereby protect the above-mentioned special feedback line, which is the same as the second two-pole device. The 2 multi-lamp backlight modules divide the same phase into the same group and use one return light tube or one or two fluorescent tubes. The conventional feedback saves the light-receiving tube and the backlight of the tube is made up of the first return capacitor or by multiple circuits, which can be implemented in the high-voltage fullness of the line, and this purpose is implemented for reduction and other purposes. For example, the third intermediate body, and one of the first lines of the line is the three-phase line, and the fluorescent tubes on the same group of fluorescent tubes are connected to one tube current. Driven and driven, many of the inventions are provided to reduce the production and provide a better second feedback group. The protection circuit is made up of a wire and a resistance return line discharge. Components and power arcs can also be used. And the excellent figure has an electric protection line between the semiconductor element device, and then the integrated feedback point can be more clear, for details

Page 14 1288278 - Case No. 93109434_Yearly Revision V. Description of the Invention (7) - Referring to Figure 3, there is shown a schematic diagram of a first multi-tube backlight module in accordance with a preferred embodiment of the present invention. The multi-lamp backlight module 3 includes, for example, a plurality of first fluorescent tubes 312, a plurality of second fluorescent tubes 314, a power supply unit 320, a first feedback line 33 2 and a second feedback Line 334. Wherein, the first fluorescent tube 3 1 2 and the second fluorescent tube 3 14 are parallel to each other and interposed twice, and the first fluorescent tube 3 1 2 has, for example, a first power end 3 1 2a and corresponding The first feedback terminal 312b, and the second fluorescent tube 31 4 has, for example, a second power supply terminal 314a and a corresponding second feedback terminal 3 14b. In addition, the power supply unit 32 includes, for example, a voltage output unit 32 2 and a feedback control unit 324, wherein the voltage output unit is, for example, always flowing to the AC voltage converter, and the feedback control unit is, for example, a PWM control chip. Referring to FIG. 3 again, the voltage output unit 3 2 2 is electrically connected to the first power terminal 31 2a and the second power terminal 31 4a respectively to provide an opposite phase AC power supply to the first fluorescent lamp 31 2 . With the second fluorescent tube 314. The second feedback line 3 3 2 and the second feedback line 3 3 4 can be formed, for example, on a printed circuit board (not shown), wherein the first feedback line 3 3 2 is electrically connected to the first feedback The terminal 312b is connected to the feedback control unit 324, and the second feedback line 334 is electrically connected between the second feedback terminal 3丨4b and the feedback control unit 32.4. In addition, the feedback control unit 32 4 is adapted to detect the first fluorescent tube 3丨2 and the second fluorescent tube 3丨4 by the first feedback line 33 2 and the second feedback line 3 3 4 The current is 'received' and corresponds to the output voltage value of the control voltage output unit 32 to maintain a stable luminance of the first glory 31 2 and the second fluorescent tube 314. A portion of the line segment corresponding to the above-mentioned first feedback line 3 3 2 and the second feedback line 3 3 4 is formed with a protection circuit, such as a comb capacitor 3 4 〇

Page 15 1288278 Case No. 9^09434_^ Amendment 5, Invention Description (8) Used to buffer the first feedback line 3 3 2. When the second feedback line 3 3 4 and the power supply unit 3 2 形成 form an open circuit The voltage is applied to avoid arcing of high voltage discharge. Wherein, when the multi-lamp backlight module 3 is in a normal state, the first feedback line 3 3 2 and the second feedback line 3 3 4 are respectively connected to the power supply device 3 2 0, at this time, the first The potential difference between the feedback line 33 2 and the second feedback line 334 is zero, and no current is generated in the comb capacitor 340. However, when the multi-lamp backlight module 3 is in an abnormal state, that is, the first return line 332 or the second return line 334 is affected by an external force and is loosened from the power supply unit 320, or due to the production line. The assembly is not correct, resulting in the opening of the first feedback line 3 3 2 or the second feedback line 3 3 4 and the power supply unit 3 2 0

The path-time comb capacitor 430 converts the voltage into a current to prevent high voltages from being generated. In addition, the plurality of combs printed on the first feedback circuit board are arranged in the first type, or the other type units are provided, except for the first signal line 332 and the The two feedback lines 334 can be equipped with the same surface of the circuit board or different surfaces. For example,

The line 332 and the second feedback line 334 can be disposed, for example, on a printed front side and a back side, respectively, and are respectively shaped like a corresponding structure in a corresponding area to constitute a plurality of comb capacitors. It is worth noting that the overlapping area of the comb structure of the line 332 and the second return line 334, the smaller the distance, the larger the capacitance of the comb capacitor. The value of the protection circuit of the present invention can also be, for example, a flat capacitor or a capacitor, and the voltage output unit and the feedback control type in the power supply unit can be changed according to actual requirements. In addition to the two j ^ comb capacitors, the present invention can also be used in printed circuit boards/type electronic components as a protection circuit and can provide other functions such as processing. Please refer to FIG. 4, which illustrates the present invention.

Page 16 1288278 Case No. 93109434 Amendment V. Description of invention (9)

There is another schematic diagram of a multi-lamp backlight module that protects the circuit. As shown in FIG. 4, the first feedback line 3 3 2 is electrically connected to one end of a first resistor 3 5 2 , and the other end of the first resistor 3 5 2 is grounded, and the second feedback line 3 3 The 4 series is electrically connected to one end of a second resistor 354, and the other end of the second resistor 354 is grounded. In addition, the first feedback line 3 3 2 and the second feedback line 3 3 4 are electrically connected to the anodes of the first diode 356 and the second diode 358, respectively, wherein the first diode The body 3 5 6 and the second diode 3 8 8 are used as filter elements for integrating the feedback signals of the first feedback line 3 3 2 and the second feedback line 3 34 into a single feedback signal. And sent to the feedback control unit 3 2 4 by a third feedback line 3 600 . In this way, not only the arc phenomenon caused by high voltage can be avoided, but also the feedback of the original two signals is reduced to one, thereby reducing the number of feedback lines required.

Please refer to FIG. 5, which is a schematic diagram of a second multi-lamp backlight module according to a preferred embodiment of the present invention. The multi-lamp backlight module 400 includes, for example, a plurality of first fluorescent tubes 412, a plurality of second fluorescent tubes 414, a power supply unit 4 2 0, a plurality of first feedback lines 4 3 2 and more The second feedback line is 4 3 4. Wherein, the DC to AC voltage converter 4 2 2 in the power supply device 410 drives the first fluorescent tube 4 1 2 and the second fluorescent tube 414 with an AC power of opposite phases, respectively, and the first fluorescent light The lamp tube 41 2 and the second fluorescent lamp tube 41 4 are interleaved and arranged in groups of two. In addition, the first feedback terminal 41 2b of each group (two) of the first fluorescent tubes 41 2 is connected to a first feedback line 432, and each group (two) of the second fluorescent tubes The second feedback terminal 4 1 4b is connected to a second feedback line 434, and the PWM control chip 4 24 is connected by a plurality of first feedback lines 432 and a plurality of second feedback lines 434. Detecting the first fluorescent tube 41 2 and the second fluorescent light

Page 17 _t^_931〇9434 1288278

V. Description of the invention (10) The tube current of the lamp tube 414 is used to perform the feedback of the supplementary line and the back of the lamp tube of the same pole tube is accurate, except for the backlight of the upper tube, etc. According to the above, the multi-lamp backlight of the present invention operates two times. Connect the fluorescent tube of the same polarity, or connect each two or two fluorescent tubes to a feedback, line, flow above =f, and drive the voltage back to the two-lamp - a multi-lamp backlight module compared to; complement. In the second light-emitting module of the invention, the fluorescent tubes are grouped and fed back, so that a more tube current can be performed to obtain a better feedback compensation effect. In addition to the detection of the fluorescent tubes, the module of the present invention can further optimize the meter according to the manufacturing cost, the output quality requirement or the other number of the fluorescent tubes connected to the feedback line. The second multi-lamp backlight module of the present invention may also be provided with a protection circuit that can be combined with a plurality of feedback 电路 circuit boards, for example, to be separately protected on multiple circuit layers of the multi-layer circuit board. The circuit and the related components and configurations are not repeated here. The above, the multi-lamp backlight module of the present invention separately supplies the fluorescent tubes of different polarities. Therefore, the problem that the positive and negative tube currents are mutually offset can be avoided, and the multi-lamp backlight module of the present invention can be greatly saved compared with the conventional backlight module which uses one return line for each fluorescent tube. The number of feedback lines 'can reduce production costs. This In addition, the feedback line of the present invention has a design of a protection circuit for avoiding arcing of high voltage discharge when an open circuit is formed between the feedback line and the power supply device, and can integrate the feedback signal to reduce the required back. The number of lines awarded to reduce costs. With this issue

Page 18 1288278 Case No. 93109434 Revision of the Year V. Invention Description (11) The multi-lamp backlight module can not only accurately detect the tube current of the fluorescent tube, but also provide better light output quality and ensure the reliability of the product. And security, and effectively enhance the competitiveness of products. While the present invention has been described in its preferred embodiments, the present invention is not intended to limit the invention, and the present invention may be modified and modified without departing from the spirit and scope of the invention. The scope of protection is subject to the definition of the scope of the patent application.

Page 19 1288278 Case No. 93109434 Year 曰 Correction Simple description of the drawing Fig. 1 is a schematic view showing a conventional multi-lamp backlight module. FIG. 2 is a schematic view showing another conventional multi-lamp backlight module. FIG. 3 is a schematic view showing a first multi-lamp backlight module according to a preferred embodiment of the present invention. FIG. 4 is a schematic diagram of a multi-lamp backlight module having another protection circuit according to the present invention. FIG. 5 is a schematic view showing a second multi-lamp backlight module according to a preferred embodiment of the present invention. [Illustration description]

1 0 0 : Multi-lamp backlight module 1 1 0 : Cold cathode fluorescent tube 1 2 0 : Power supply unit 1 2 2 : DC to AC voltage converter 124: PWM control chip 1 3 0 : Feedback line 2 1 0: cold cathode fluorescent tube 2 1 2 : first fluorescent tube 214: second fluorescent tube 2 2 0 : power supply unit

3 0 0: multi-lamp backlight module 312: first fluorescent tube 312a: first power terminal 312b: first feedback terminal 314: second fluorescent tube

Page 20 1288278 Case No. 93109434 Yearly Correction Diagram Simple Description 314a 314b 3 2 0 : 322 324 332 334 340 400 412 412b 414b 414 420 422 424 432 434: Second Power Terminal: Second Feedback Terminal Power Supply Voltage Output unit feedback control unit first return line second return line comb capacitor multi-lamp backlight module first fluorescent tube: first feedback terminal: second feedback terminal second fluorescent tube power supply Device DC to AC voltage converter PWM control chip first return line second return line

Page 21

Claims (1)

1288278 Case No. 93109434 Amendment VI. Patent Application Range 1. A multi-lamp backlight module, comprising: a plurality of first fluorescent tubes, each of the first fluorescent tubes having a first power end and corresponding a first feedback terminal; a plurality of second fluorescent tubes, each of the second fluorescent tubes having a second power terminal and a corresponding one of the second feedback terminals, wherein the first fluorescent lamps The lamp tube and the second fluorescent lamp tube systems are parallel to each other and are interposed in an interpenetrating configuration; a power supply device that respectively supplies alternating phase power sources to the first power source end and the second power source ends; a first feedback line electrically connected between the first feedback terminals and the power supply device; and a second feedback line electrically connected between the second feedback terminals and the power supply device . 2. The multi-lamp backlight module of claim 1, wherein the power supply device comprises a voltage output unit electrically connected to each other and a feedback control unit, wherein the voltage output unit is coupled to the A power supply terminal and the second power supply terminals are electrically connected, and the feedback control unit is electrically connected to the first feedback line and the second feedback line. 3. The multi-lamp backlight module of claim 2, wherein the voltage output unit comprises a DC-AC inverter 0. 4. As described in claim 2 The multi-lamp backlight module, wherein the feedback control unit comprises a pulse width modulation control chip (PWM c ο ntr ο 1 IC). 5. The multi-lamp backlight module as described in claim 1 of the patent application, further includes Page 22 1288278 Case No. 93109434 曰 修正 Amendment VI. The patent application scope includes a protection circuit electrically connected between the first feedback line and the second feedback line. The multi-lamp backlight module described in item 5, wherein the volume is contained. The multi-lamp backlight module according to item 5, wherein the protective circuit is a comb-like electric power according to the patent application scope. The protection circuit includes: a first first set; a resistor, a battery The diode is electrically connected between the first feedback line and the ground; and is electrically connected to the first feedback line and the power supply resistor, and is electrically connected between the second feedback line and the ground; A second diode is electrically connected between the second feedback line and the power supply device. 8. If the patent application includes a third feedback line, the first diode is electrically connected to the electricity. 9. A multi-lamp is used for the first power supply and the second power supply. And a plurality of lamp backlight modules according to item 7 of the second power source and the second source device, and one of the third feedback lines is electrically connected to the first a diode, and the other end of the third feedback line source device. The backlight module comprises: a light tube, each of the first fluorescent tubes has a first feedback end; and a light tube, each of the second fluorescent tubes has a one a second feedback terminal, wherein the first fluorescent light tubes are parallel to each other and are interleaved and arranged; the power supply device respectively provides alternating phase 4» Page 23 1288278 Case No. 93109434_Yearly revision _ 6. Applying the patent range power supply to the first power supply terminal and the second power supply terminals; a plurality of first feedback lines are electrically connected to the first Between the feedback terminal and the power supply device, wherein each of the N first fluorescent lamp tubes is electrically connected to one of the first feedback lines, and the total number of the first fluorescent tubes is 2 N2 2 ; a plurality of second feedback lines are electrically connected between the second feedback terminals and the power supply device, wherein each of the second fluorescent lamp lines corresponds to one of the second feedback lines Sexual connection, and the total number of second fluorescent tubes g Μ - 2. The multi-lamp backlight module of claim 9, wherein the power supply device comprises a voltage output unit electrically connected to each other and a feedback control unit, wherein the voltage output unit is A power supply terminal and the second power supply terminals are electrically connected, and the feedback control unit is electrically connected to the first feedback lines and the second feedback lines. 11. The multi-lamp backlight module of claim 10, wherein the voltage output unit comprises a DC-AC inverter 0 1 2 as claimed in claim 10 The multi-lamp backlight module, wherein the feedback control unit comprises a pulse width modulation control chip (PWM contro 1 IC) 〇1 3 , such as the multi-lamp backlight module described in claim 9 Further comprising at least one protection circuit, and the protection circuit is electrically connected between one of the first feedback lines and one of the second feedback lines. 1 4. The multi-lamp backlight module of claim 13, wherein the protection circuit is a comb capacitor. </ RTI> </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; One of the first feedback lines is connected to the ground; a first diode is electrically connected between the one of the first feedback lines and the power supply device; and a second resistor is electrically connected to One of the second feedback lines and ground; and A second diode is electrically connected between one of the second feedback lines and the power supply device. The multi-lamp backlight module of claim 15, further comprising a third feedback line, wherein one end of the third feedback line is electrically connected to the first diode And the second diode, and the other end of the third feedback line is electrically connected to the power supply device. Page 25 1288278 Case No. 93109434 修正 Amendment VI. Designation of Representative Representatives (1) The representative representative of this case is: Figure 3 (2), the representative symbol of the representative figure is a simple description 3 0 0: Multi-lamp backlight module 312: First fluorescent tube 312a: first power terminal 312b: first feedback terminal 314: second fluorescent tube 314a: second power terminal 314b: second feedback terminal 3 2 0: power supply device 3 2 2: voltage output unit 324: feedback control unit 3 3 2: first feedback line 3 3 4: second feedback line 3 4 0 : comb capacitor Page 7