TWI377535B - Backlight module and driving method thereof - Google Patents

Description

1377535 0710056ITW 23953twf.doc/n IX. Description of the Invention: 1. Field of the Invention The present invention relates to a backlight module and a driving method thereof, and more particularly to a light emitting diode (LED) Backlight module and its driving method. [Prior Art] In recent years, backlight modules for liquid crystal displays have used LEDs with long life, high efficiency, and low environmental pollution (Li"

Emitting Diode, LED) as a backlight. As LCD panels become larger and larger, their backlight modules use more LEDs to provide adequate backlighting. Therefore, the circuit that drives the LED will generate more power consumption. Referring to the figure 图, Fig. j is a diagram showing the temperature distribution relationship of the backlight unit back plate 10 during heat balance. Due to the liquid crystal display in general use, the backlight of the LED backlight mechanism is substantially perpendicular to the desktop (or horizontal plane). Therefore, in the state of thermal balance, the heat generated by the backlight module makes the backplane of the machine 1 from bottom to top. The temperature distribution is from low temperature to high temperature. "Please, see Figure 2, Figure 2 is the relative relationship between the LED's forward conduction current, the forward conduction 2 pressure and the ambient temperature. ® 2 draws a line with 3 shaft conductions' to take one of the curves and lines: As the LED's forward conduction current iFP^ rises, the LED's on-voltage will drop as the temperature rises. s February f test Figure 3, Figure 3 is the circuit diagram of the conventional backlight module.匕Including N-group LED driving circuit: illuminating element; 301 to 1377535 0710056ITW 23953twf.doc/n 30N respectively coupled to the corresponding dimming circuits 33i to 33N ^The heat generated by the backlight module is in thermal equilibrium state Under the LED backlight mechanism, the temperature of the back panel will change differently, so that the ambient temperature of each of the light-emitting elements is not the same 'the brightness is also different', which is easy to cause poor display. Therefore, the backlight module 3 is conventionally designed. 〇〇In the N-type LED driving circuit, N feedback signals Vml to VmN are taken out for closed loop driving control, and then the output of the DC power converter 31A is adjusted. However, the feedback compensation circuit 320 is designed. To process N feedback signals Vm l The complexity of the VmN is quite high, and designing N feedback signals increases the difficulty of circuit wiring, so the circuit cost of the backlight module 300 is also relatively increased. SUMMARY OF THE INVENTION The object of the present invention is to provide a backlight The module can use less feedback signals for closed loop control, which can reduce the complexity of the design feedback compensation circuit, reduce the difficulty of circuit wiring, and reduce the circuit cost of the module.

The invention further provides a driving method for a backlight module, which can adjust the operating voltage of the DC source conversion ,, and can control the loopback control signal to reduce the temperature of the backlight module to reduce power consumption, and can Improve the life of the LED, so you can improve the 'circuit performance. The present invention provides a backlight module which is formed with a plurality of temperature distribution regions according to a heat dissipation system. The temperature distribution regions 1 are closed to the lowest temperature region, and the backlight module includes a light-emitting diode drive= 0710056ITW 23953twf.doc/n DC power converter and feedback compensation circuit. The LED driving circuit is configured to provide a backlight and generate a first feedback signal, and the LED driving circuit comprises a plurality of light emitting elements and a plurality of dimming circuits. The light-emitting elements are configured to receive a working voltage to generate a backlight, and the first light-emitting elements of the light-emitting elements are disposed at a temperature lower region β. The dimming circuits are configured to provide driving currents of the light-emitting elements. The optical circuit is lightly connected to one of the corresponding light-emitting elements, and the first feedback signal is obtained from a coupling of the first light-adjusting circuits of the dimming circuits corresponding to the first light-emitting elements. The DC power converter is coupled to the LED driving circuit, and adjusts and outputs the operating voltage according to the voltage compensation signal. The feedback compensation circuit is coupled between the DC power converter and the LED driving circuit for receiving the first feedback to generate a voltage compensation signal. In the above backlight module, in one embodiment, the feedback compensation circuit includes a first error amplifier and a first voltage compensator. The first error amplifier receives the first reference signal and the first feedback signal, and compares the first reference signal with the first feedback signal to obtain an output. The first voltage compensator is coupled between the output of the first error amplifier and the DC power converter, and accordingly generates and outputs a voltage compensation signal. In another embodiment, in one embodiment, one of the light-emitting elements is disposed in a lowest temperature region, and the LED driving circuit generates a second feedback signal, and the second feedback signal The number is obtained from the coupling of the second dimming circuit of the dimming circuits corresponding to the second lighting element. The feedback compensation circuit further receives the second feedback signal, and generates a voltage compensation signal according to the average value of the first feedback "唬" and the second feedback signal. 1377535 0710056ITW 23953twf.doc/n The invention further provides that the driving rib of the backlight module comprises a light emitting diode driving circuit, a DC power conversion and a feedback compensation circuit. The light emitting diode driving circuit comprises a plurality of light emitting Γ* two optical circuits. The method includes the following Step: the relative relationship of the heat dissipation direction of the backlight mode is divided into a plurality of temperature distribution regions, and the driving is the lowest temperature region; the first-th light of the light-emitting diode optical component is the first feedback signal from which the first feedback signal is generated The first-modulation photoelectric 3 missing feedback compensation circuit of the dimming circuit receives the first-receiving signal, and generates a converter receiving the charging signal, and provides, provides, and works according to the voltage=domain wire. The voltage to the LED driver is configured to receive the first feedback signal to generate a voltage compensation signal. The driving method of the backlight module described in the other embodiment further includes two: the light emitting diode circuit generates a third feedback signal, and the second long (four) miscellaneous recording element n light element = is obtained, And the (5) breaks the configuration of the U's most healthy domain. The compensation circuit receives the average value of the second feedback signal and the second coffee number. The backlight module of the present invention divides the plurality of temperature distribution areas according to heat dissipation. The feedback compensation circuit of the temperature range 1377535 0710056ITW 23953twf.d〇c/n is the lowest temperature. The area couch = ^ ^ ' and generate compensation power is willing to DC power converter to adjust: work, and thus simplify the feedback compensation circuit to receive feedback S, instead of sending more feedback signals to the feedback than the original Compensation for the road. Therefore, the present invention can reduce the warming amount of the compensation circuit and the LED driving circuit. The fishing device and the driving method of the invention can reduce the _ degree of the phase-adding circuit, reduce the difficulty of the circuit, reduce the circuit cost of the backlight module, reduce the power consumption of the backlight module, and reduce the backlight of the LED. The temperature of the module increases the lifetime of the LED, which in turn improves the circuit performance of the entire backlight module. The above and other objects, features and advantages of the present invention will become more apparent from the aspects of the appended claims. [Embodiment] The inventor of the present invention has a complicated circuit design in view of the circuit design of the conventional backlight module, and the present invention has been produced by analyzing and simulating various situations. One of the main features of the present invention is to extract feedback signals from the lowest temperature region for processing. The embodiments of the present invention are described below. Referring to FIG. 4(a), FIG. 4(a) is a diagram showing a plurality of temperature distribution regions divided by a backlight of a light emitting diode (LED) backlight mechanism according to an embodiment of the invention. In order to alleviate the complexity, it is conventional to require N feedback signals Vml to VmN' to reduce the feedback signal required by the prior art in the embodiment of the present invention. First, the backlight module forms a plurality of temperature distribution regions according to the relative relationship of the heat dissipation directions 10 1377535 0710056ITW 23953twf.doc/n. In FIG. 4(a), the backlight module is disposed on the LED backlight mechanism back plate 40, and the LED backlight mechanism back plate 4 is divided into three temperature distribution regions, which are respectively a T1 region, a T2 region, and a D3 region. Those skilled in the art should be able to understand that the temperature distribution region can be divided into regions based on thermal equilibrium simulation or experimental results, so the number of temperature distribution regions is not limited. Assuming that the LED backlight mechanism is configured such that the board 40 is erected on the desktop, the LED backlight mechanism has a heat-dissipating aperture for four weeks or only the uppermost heat-dissipating aperture. Therefore, when the liquid crystal display in use is in thermal equilibrium, the LED backlight mechanism backplane 40 will be the hottest in the T1 region, followed by the T2 region, and the T3 region has the lowest temperature region. When designing the moonlight module, the LEDs in each zone are different due to the ambient temperature, so the forward voltage of the LEDs in each zone will be different. The LED in the T1 area has the smallest forward voltage, the LED in the T3 area has the largest forward voltage, and the LED in the T2 area has the largest forward voltage. After dividing the above into multiple temperature zones, it is necessary to reduce the number of summers. The intention to reduce the number of feedback signals is to retrieve the feedback signal from a certain area, so the complexity of processing the feedback signal will be reduced a lot. For the verification, please refer to Figure 4(b), and carry out the following experiments. . Fig. 4(b) is a circuit diagram of a backlight module according to a plurality of temperature distribution regions of Fig. 4(a). The backlight module 42 includes a T1 area light emitting element, a T2 area light emitting element, and a T3 area light emitting element. Wherein, the Τ1 area illuminating element comprises the illuminating elements 41a, 41b..., and the T2 area illuminating element comprises the illuminating elements 43a, 43b... ’ T3 area illuminating element

The light-emitting elements 45a, 45b, ... are included and each of the light-emitting elements includes at least one light-emitting diode. X 11 < S) 1377535 0710056ITW 23953twf.doc/n In order to analyze the backlight module 42 in the T1E? is the second case of the cold machine, the mode: the machine, the open circuit control of the analog zone; Open loop control of three thermal analog T3 zones. Figure _ monthly hair ^ ^ 4 (4) LED backlight mechanism back plate 4 ^ ^ pieces in the picture of a backlight module 42 back to the first board of the relative relationship diagram. Times • institution a

Here, the analysis of the above various cases is carried out, assuming that the light-emitting elements are made up to 41c, 43a to 43c, 45a to 45c' and the light-emitting elements are the same, and the number is the same, and the LEDs are connected in series. Please refer to Figure 4(d). The figure shows the open loop control architecture diagram of Figure 4(b). The DC power conversion boundary 4 drives the light-emitting element 46 to generate the operating voltage VLED, that is, the driving power of the LEDs 1 to LEDN. The sum of the voltages of the respective light-emitting diodes (Vfi, %.....VfN) is the sum of the light-emitting elements %

The turn-on voltage Vf_tota dimming circuit 47 includes a switch SW and a constant current source II. The voltage Vm is generated from the junction of the light-emitting element 46 and the dimming circuit 47, and the relationship is VLED = Vf - total + Vm. (Assume that the illuminating element 46 is currently using four illuminating diodes' and the forward conduction voltage of each illuminating implant is equal to 2V.) 'In the first case, when the chiller is simulated, the open loop control is performed, so the operating voltage The VLED is fixed. Here, a data sheet is provided. When the constant current source n is 20 mA, the operating voltage VLED is 9 V, the Vf is 8 V, and the voltage Vm is IV, and the Vm power consumption is 2 〇 mV: Next, the second In the case of a heat engine, the analog circuit T1 opens the circuit 12 (s 1377535 0710056ITW 23953twf.doc/n control. Provided here - data sheet, when the constant current source n is 2 mA, the work voltage is 9V, The conduction voltage Vf hits 6 degrees, and (4) the voltage Vm is 2.2V', and its Vm consumes power. Therefore, the forward voltage of each light-emitting diode drops to 〇3v. When the third condition is a heat engine, Analog T3 zone _ open loop control. Here is provided - data data, when the constant current source ^ is 2QmA, the working voltage VLED is 9V, 'the forward voltage vf_t_ is 7 6v, and the voltage m is 1.4V 'Vm &gt The power consumption of the xiao is 2gmv. Therefore, the power of each illuminator and diode is reduced to 〇lv. For the above two simulation cases, please refer to Figure 4(e) after arranging the data. In addition to the temperature rise, the forward voltage Vf_total drops 'and the voltage Vm rises, The power consumption of the switch is large, which makes the power loss increase σ and makes the component efficiency worse. Next, the fourth situation and the fifth situation are simulated. The fourth case is the simulation of the T1 zone. The feedback signal is closed loop control; • When the fifth case is a heat engine, the analog capture T3 zone feedback signal is used for closed loop control. Among them, the fourth and fifth cases are only for one temperature distribution area. Control is given, while the other two areas are not controlled by feedback. In the fourth case, the feedback signal Vmla or Vmlb is taken or the average value of the feedback signals Vmla and Vmlb is taken. In the fifth case, the feedback signal Vm3a or Vm3b or the average value of the feedback signals Vm3a and Vm3b. Please refer to Fig. 4(f), Fig. 4(f) is the structural diagram of the closed loop control when simulating the heat engine in Fig. 4(b). Originally in Fig. 4 ( The voltage Vm of d) is now a feedback signal of Fig. 13 <S) 1377535 0710056ITW 23953twf.doc/n 4(f). The light-emitting element 46 uses four identical light-emitting diodes. The feedback compensation circuit 49 includes an error amplifier 49b coupled to the voltage compensator 49a' voltage compensator 49a between the error amplifier 49b and the DC power converter 48b. The error amplifier 4A receives the feedback signal Vm and a reference signal Vref, and the voltage compensator 49a generates a voltage compensation signal 49c to the DC power converter 48b. The DC power converter 48b adjusts and outputs the operating voltage VLED based on the voltage compensation signal 49c. When the fourth case is a heat engine, the analog capture T1 zone feedback signal is used for closed loop control. Here, a data feed is provided for the data. When the constant current source II is 20 mA and the original working voltage VLED is 9 V, the compensation is performed. The operating voltage VLED is 7 8v. The forward conduction voltage vf_t〇tai in the T1 region is 6.8V, so the voltage Vm in the T1 region is IV, but the forward conduction voltage vf_total in the T3 region is 7.6V, which causes the light in the lower temperature region (T3 region). Insufficient operating voltage of the component makes the light-emitting diode unstable. Then, 'when the fifth case is a heat engine', the simulation draws the feedback signal of the T3 area to perform closed loop control. Here, a data is provided. When the constant current source Π is 20 mA and the original working voltage Vled is 9 V, the compensation is performed. The operating voltage VLED is 8.6V. The forward voltage vf_t〇tal of the T3 region is 7.6V', so the voltage Vm of the T3 region is L0V; while the forward voltage Vfjotal is 6.8V, and the voltage Vm of the T1 region is 丨8V. Therefore, when the voltage VLED is adjusted downward to 8.6V, the driving circuit of the backlight module 42 of Fig. 4(b) can be covered. For the simulation of the fourth and fifth cases mentioned above, please refer to Figure 4(g) after sorting the data, in which the compensation is performed with the higher temperature region, and the adjusted operating voltage 乂1^1) and temperature The JL of the component between the lower region 0710056ITW 23953twf.doc/n and the forward voltage Vf-total is unstable. It proves that the ',' § causes the most fading area of the illuminating method (the back-spinning group and its drive number are clearly defined, and the adjustment result is f (^) is the lowest area of the feedback reliability. "Women area" took ^^^^. Therefore, it is feasible to return the compensation to Wei from the implementation of Wen. It is reduced to three-thirds. The complexity of processing the feedback signal can be divided into 5ΐ: according to the temperature of another embodiment of the present invention. The area, as shown in the figure, is divided into nine zones. Assuming the general situation, the LED backlight is in the second zone and the C1 zone ~ C3, the LED backlight mechanism is backed up = the mechanism moonboard 50 is standing on the desktop. The top has a heat-dissipating small hole because of Γ, Α1Γ to the weekly hot hole or only the second highest temperature, and the shape 'from the α-area~C34=configuration; the temperature distribution of the plate 50 is the light-emitting element Take the j control that is configured in its area number to adjust all the light-emitting elements. According to the feedback point of the operation point, the general knowledge should be able to understand the work;!= Of course, this item, 5Γ丨V says 々h "攸 Located in the Cl area to the C3 area, the average value of the points is taken as the feedback value = the spirit range, and the protection scope of the present invention is not limited to the implementation _ degree points; according to another embodiment of the present invention At the temperature, we divide the LED backlight backplane into nine 1377535 0710056ITW 23953twf.doc/,

The area 'As shown in Fig. 5 (8), A1 area ~ A3 area, m area ~ B3 area disk C ^ is not flat ^ this C1 area and the 〇 area (four) board (4) heat sink. Therefore, at , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Take the feedback signal of the point = value, and then adjust the common working voltage of all the light-emitting components.

The ==3 zone of the light-emitting elements - the point of the feedback control = the common working voltage of all the light-emitting elements of the jade.

4 Refer to Figure 5(c). 5(c) is a temperature knives area map in accordance with another embodiment of the present invention. This is similar to the method of Fig. 5(b). Similarly, the C1 and C3 areas of the back panel 50 of the coffee-backing mechanism can be installed with air, and the temperature of the C1 and C3 1 is minimized at the thermal balance 4'. Therefore, the backlight mold can be taken from the C1 area and the C3 area, and each of the light-emitting elements arranged in the area is taken as a feedback control, and the feedback value is returned according to the feedback signals of the two extraction points. Adjust the common working power of all the light-emitting elements; or just take the collapse point of one of the C1 area or C3 @ light-emitting elements for feedback control, and then adjust the common working voltage of all the light-emitting elements. 5(b) and 5(c), this technique has the general knowledge that f should be able to dissipate heat # or the fan is to ensure that the alpha zone and C3 are the temperature-lower zone. Other methods of heat dissipation are achieved: the area with the lowest temperature is the heat dissipation design relative to the backplane. When considering the symmetry of the average heat dissipation, the area with the lowest temperature can be in the two sides of the back plate. In addition, the number of divided temperature zones and the number of heat sinks are not limited. There are 1377535 • · 0710056ITW 23953twf.d〇c/n Xu Xi, kind. Therefore, the scope of protection of the present invention should not be limited by the embodiments, without departing from the spirit and scope of the invention. . 'Please refer to Figure 5(d). Figure 5 (d) is a circuit of a light-emitting mode, 1 according to another embodiment of the present invention. The backlight module 5GG is disposed on the LED backlight mechanism back plate 5A having the heat sink as shown in FIG. 5(b) or FIG. 5(c). The backlight module 5〇〇 forms a plurality of temperature distribution regions according to the relative relationship of the heat dissipation directions, as shown in Fig. 5(a). The focus of the present invention is to extract the feedback signal from the "lowest temperature region", as shown in Fig. 5(a) and Fig. 5(d): the C1 zone and the C3 zone are the lowest temperature zones, and the C1 zone and the C3 zone are taken from the C1 zone and the C3 zone. The first feedback signal Vmcl and the second feedback signal Vmc3 are used for closed loop control. The backlight module 500 includes a light emitting diode driving circuit 52, a DC power converter 51, and a feedback compensation circuit 55. The LED driving circuit 52 is coupled between the DC power converter 51 and the feedback compensation circuit 55. The light-emitting body driving circuit 52 includes a plurality of light-emitting elements and a plurality of light-modulating circuits. Each of the light-emitting elements includes at least one light-emitting diode, and the forward-pass voltage characteristics of the light-emitting diodes are affected by the ambient temperature. Each dimming circuit package includes a switch SW and a constant current source I, wherein one end of the switch SW is coupled to one of the corresponding light-emitting elements, and the other end of the switch SW2 is coupled to the corresponding constant current source I, and the corresponding The other end of the constant current source is grounded. Each dimming circuit can provide a driving current of its corresponding light-emitting element. The light-emitting element can generate a backlight after receiving the working voltage VLED, and the first light-emitting element 510 and the second light-emitting element 511 of the light-emitting elements are disposed at the lowest temperature. The area in which the lowest temperature region is further provided with a heat sink. The first feedback signal Vmcl is obtained from the coupling of the first dimming circuit 512 of the first photo-emission element 51 corresponding to 17 (S) 1377535 0710056ITW 23953twf.d〇c/n. The second feedback signal is obtained from the coupling of the second dimming circuit 514 of the dimming circuit corresponding to the second light emitting element 511. Therefore, the LED driving circuit 52 further generates a first feedback signal Vmcl and a second feedback signal Vmc3. The feedback compensation circuit 55 includes an error amplifier 59 and a voltage compensator 57. The error amplifier 59 receives the reference signal Vref, the first feedback signal Vmcl and the second feedback signal Vmc3' and compares the average of the reference signal Vref, the first feedback signal Vmcl and the second feedback signal Vmc3 to obtain an output. In order to avoid the feedback signal, it is possible to compare the average value of the two feedback signals with the reference signal Vref. Of course, it is also possible to compare the reference signal Vref with only the first or the same. The voltage compensator 57 is coupled between the output of the error amplifier 59 and the DC power converter 51, and accordingly generates and outputs a voltage compensation signal 53. The DC power converter 51 can adjust the input and output powers of different DC levels according to the voltage compensation signal 53 in a pulse width modulation manner, and output an operating voltage VLED. The type of the DC power converter 51 can be a conventional step-up DC power converter, a step-down DC power converter, or a buck-boost DC power converter, and will not be described here. Let us compare the difference between FIG. 3 and FIG. 5(d). In the conventional technology, the backlight module 300 of FIG. 3 adopts a considerable number of feedback signals, and the heavy feedback signal quantity of the light-emitting module 300 makes the conventional The feedback compensation circuit 320 will therefore be overloaded. In the backlight module 5A of FIG. 5(d), the configuration of the feedback compensation circuit 55 is relatively simple, and the feedback compensation circuit 55 1J/7535 0710056ITW 23953twf.doc/n processes the number of feedback signals. Compared with the feedback compensation, the power is less. Therefore, the number of feedback signals in the embodiment of the present invention is reduced, and the complexity of designing the feedback compensation circuit 55 also reduces the difficulty of circuit wiring i and the circuit cost of the backlight modules 1 and 5〇0 is compared with that of the backlight module 3. He also followed suit. In addition to the backlight module of the above embodiment, the present invention also includes a method of driving a backlight module. For those skilled in the art of the present invention, the backlight module embodiment of the present invention should be capable of driving the backlight module of the present invention, and therefore will not be described. 〇In summary, the present invention simplifies the number of feedback apostrophes received by the feedback compensation circuit, and the backlight module uses the feedback signal from the "lowest temperature region" as closed loop control instead of transmitting a plurality of backs. The signal is sent to the edge compensation circuit. Therefore, the present invention can reduce the amount and line of return money between the feedback compensation circuit and the emitter drive circuit. The moonlight module of the present invention and the driving method thereof have at least the following advantages: L uses less feedback signals for closed loop control; • 2) reduces the complexity of the design feedback compensation circuit; 3. reduces the difficulty of circuit wiring 4. Reduce the circuit cost of the backlight module; 5. Reduce the power consumption of the backlight module; 6. Reduce the temperature of the LED backlight module; 7 Improve the life of the LED; 8. Sharpen the backlight module Circuit performance. Although the present invention has been disclosed above by way of example, it is not intended to limit 19 c: S) 1377535 0710056ITW 23953 twf.doc/n The present invention is in the ordinary skill of the art without departing from the spirit and scope of the present invention. The scope of protection of the present invention is defined by the scope of the appended claims. [Simplified description of the figure] ^ Figure 1 is the temperature distribution relationship of the back panel of the LED backlight mechanism during thermal equilibrium. .2 is a graph showing the relative relationship between the forward current of the LED and the temperature of the looped current. 〃不兄 Figure 3 is a circuit diagram of a conventional backlight module. Fig. 4 (a) is a view showing a plurality of temperature distribution regions divided by a light-emitting diode backlight mechanism according to an embodiment of the present invention. The circuit ^ 4 (b) is a backlight module according to the plurality of temperature distribution regions of FIG. 4 (a) wins & A 4 Figure 4 (C) is the backlight element of the backlight module of Figure 4 (b) and the led backlight The relative relationship between the moon and the moon. Figure 4(d) is a diagram showing the open loop control architecture of Figure 4(b). =4(e) is the electrical characteristic diagram of the cooling machine when simulating open circuit control. Solid (f) is an architectural diagram of analog closed loop control.夂彳 夂彳 = g) is a comparison chart of voltages for feedback compensation for high temperature and low temperature regions, respectively. S(a) to FIG. 5(C) are temperature distributions according to another embodiment of the present invention.

C S 20 1377535 0710056ITW 23953twf.doc/n FIG. 5(d) is a circuit diagram of a light emitting module according to another embodiment of the present invention. [Description of main component symbols] 10, 40, 50: LED backlight mechanism back plates 41a, 41b, 43a, 43b, 45a, 45b, 46, 301 to 30N: light-emitting elements 42, 500: backlight modules 47, 331 to 33N: Dimming circuits 48a, 48b, 51, 310: DC power converters 49, 55: feedback compensation circuits 49a, 57: voltage compensators 49b, 59: error amplifiers 49c, 53: voltage compensation signal 52: LED driving Circuit 300: conventional backlight module 320: conventional feedback compensation circuit 510: first light-emitting element 511: second light-emitting element 512; first light-adjusting circuit 514: second light-adjusting circuit GND: ground I, II: Current source Ipp. Forward conduction current 21 1377535 0710056ITW 23953twf.doc/n LED1~LEDN: Light-emitting diode. SW: Switch

Vf_total : forward conduction voltage ' VLED : operating voltage

Vm : voltage (feedback signal)

Vml~VmN, Vmla, Vmlb, Vm3a, Vm3b: feedback signal

Vmcl: first feedback signal • Vmc3: second feedback signal

Vref: reference signal

twenty two

Claims (1)

1377535 0710056ITW 23953twf.doc/n X. Patent application scope: 乂 A backlight module, which forms a plurality of temperature distribution regions according to the relative relationship of heat dissipation directions, wherein one of the temperature distribution regions is a lowest temperature region The backlight module includes: a light emitting diode driving circuit for providing a backlight and generating a first feedback signal, wherein the LED driving circuit comprises: a light emitting component for receiving an operating voltage a backlight f′ is generated and the first light-emitting element of the neo-light element is disposed at the lowest temperature region; and a plurality of dimming circuits are configured to provide driving currents of the light-emitting elements, each of: the dimming circuit is coupled to Corresponding to one of the light-emitting elements, and the first-receiving (four) is obtained from a coupling of the first dimming circuit of one of the dimming circuits corresponding to the first light-emitting element; - a DC power conversion H, Secret to the LED driving circuit, and adjusting and outputting the operating voltage according to a voltage compensation signal; and - feedback compensation circuit, pure to the DC converter Made between the diode driving circuit for receiving the second - the feedback signal, the compensation voltage according to the raw signal. 2. The backlighting level as recited in claim 2, wherein the compensation circuit comprises: Λ a first error amplifier receiving a first reference signal and the first signal and comparing the first reference signal with the first 1 signal output; and & - voltage compensator, reduced to the first - error A | | round 23 1377535 0710056ITW 23953twf.doc / n and the DC power converter, and according to The voltage compensation signal is output. 3. The backlight module of claim 2, wherein the lowest temperature region is provided with a heat sink. 4. The backlight module of claim 3, wherein the heat sink is a heat sink, a fan or a water cooling device. 5. The backlight module of claim 1, wherein each of the light-emitting elements comprises at least one light-emitting diode. 6. The backlight module of claim 5, wherein the forward voltage of the light-emitting diode is affected by the ambient temperature. 7. The backlight module of claim 1, wherein each of the dimming circuits comprises: a switch having one end coupled to one of the corresponding light-emitting elements; and A current source coupled between the switch and ground. 8. For the backlight module described in the scope of the patent application, The second light-emitting element is disposed at the lowest temperature region, and the driving circuit further generates a second feedback signal, and the second light-emitting element (four) of the second light-emitting elements corresponds to the dimming One of the circuits is obtained by coupling the second to nine circuits. The backlight module of claim 8 , wherein the back-to-back 】--< receives the second feedback signal, and generates the voltage compensation according to an average value of the first feedback feedback signal signal. The back wire group described in the eighth aspect of Patent No. 11, wherein the back 24 CS) 1377535 0710056ITW 23953twf.doc/n compensation circuit comprises: a second error amplifier receiving a second reference signal, the first back credit And the second feedback signal, and comparing the average of the first reference signal, the first feedback signal and the second feedback signal to obtain a round-out ^; A second voltage compensator is coupled between the wheel outflow power converters of the second error amplifier, and accordingly generates and outputs the voltage compensation signal. The backlight module of claim 1, wherein the linear power converter adjusts the operating voltage in a pulse width modulation manner. " 12·If you apply for the f-light module described in item i of the patent scope, 湄丝秘众 and ^ ^ _ ΛΜ- The power converter is a boost DC power converter source converter or a buck-boost DC power converter. Secondly, the L3·-age optical mold mosquito shaft method comprises a light-emitting: an η-channel, a DC power converter and a feedback compensation electro-optical photoelectric== road comprising a plurality of light-emitting elements and a plurality of step-down direct current The bth LED driving circuit generates a flute-receiving signal from the light-emitting element light-emitting elements in the lowest temperature region; the first feedback signal, and the first light-emitting element corresponds to 25 1377535 0710056ITW 23953twf.doc/n Receiver-receive _, and generate a d. The DC power converter receives the voltage compensation voltage compensation signal to operate, provide and output - work to the polar body drive circuit. According to the method of claim 13, wherein the light-emitting elements receive the voltage, the dimming circuits are lightly connected to the light-emitting elements, and each of the light-emitting elements is consumed. The components of the 调--the dimming circuit are used to provide the driving current of the 7G piece of the yarn. The driving compensation circuit of the backlight module described in claim 13 is lightly connected between the DC power converter and the transmitter for receiving the first feedback signal, thereby generating the voltage compensation signal. 16. The driving power of the DC power supply is automatically connected to the LED driving circuit, and the operating voltage is adjusted and output according to the voltage compensation signal.驱动. The driving method of the backlight module described in claim ls, wherein the feedback compensation circuit comprises: “the first error amplifier receiving-the first reference signal and the first returning tiger’ and comparing the first And outputting the first reference signal and the first feedback signal; and - the first voltage compensation n' is output to the output of the first 黯 amplifier, and between the DC power converters 26 (S) 1377535 0710056ITW 23953twf.doc/n Compensation signal 18. The driving method of the backlight module according to claim 13 further includes: bl. The LED driving circuit generates _ second credit And the second (four) is obtained from the region of the second dimming circuit of the dimming circuit corresponding to the second illuminating element, and the second illuminating element is disposed at the lowest temperature region ;as well as Cl. The feedback compensation circuit receives the second feedback signal and generates a compensation signal based on the average of the first-return money_second gambling money. 19. The method of driving a backlight module according to claim 18, wherein the feedback compensation circuit comprises: - a second error amplifier, a receiving - a second reference signal, the first feedback signal, and the second Retrieving (4)' and comparing the average of the second feedback signal and the second feedback signal to obtain an output; The first voltage compensator is coupled between the output of the second error amplifier and the DC converter, and shouts and outputs the voltage compensation signal. 20. The driving method of the backlight module as described in the patent scope 613 of June, wherein the lowest temperature region is provided with a heat sink. 21. The driving method of the backlight module as described in claim 2G, wherein the heat sinking system is a heat sink, a fan or a water cooling device. 22. The method of claim 27, wherein the light-emitting elements comprise at least one light-emitting diode, wherein the light-emitting elements of the backlight module are as claimed in claim 13 of the invention. 23. The driving method of a backlight module according to claim 22, wherein the forward voltage of the light emitting diode is affected by an ambient temperature. The driving method of the backlight module of claim 13, wherein each of the dimming circuits comprises: a switch, one end of which is coupled to one of the corresponding light-emitting elements ;as well as A constant current source is coupled between the switch and the ground. 25. The driving method of a backlight module according to claim 13, wherein the DC power converter adjusts the operating voltage in a pulse width modulation manner. 26. The driving method of a backlight module according to claim 13, wherein the DC power converter is a step-up DC power converter, a step-down DC power converter or a buck-boost DC power converter. . c s > 28