CN101193488A - Brightness adjustment method and device - Google Patents

Abstract

The invention relates to a brightness adjusting method, which is used for adjusting the brightness of at least one fluorescent lamp. The invention also discloses a brightness adjusting device. The material cost of the temperature sensing element can be eliminated.

Description

Brightness adjustment method and device

technical field

The present invention relates to a brightness adjustment method and device, in particular to a brightness adjustment method and device.

Background technique

With the advancement of electronic technology, especially the prevalence of portable electronic products in daily life, the demand for thin and light displays with low power consumption is increasing day by day. Among them, Liquid crystal display (LCD) has been used in various electronic products for its advantages of low power consumption, low heat generation, light weight, and non-radiation, and has gradually replaced Traditional cathode ray tube display (Cold Cathode Tube Display, CRT Display).

Generally speaking, a liquid crystal display mainly includes a liquid crystal panel and a backlight module. Wherein, the liquid crystal panel has two substrates and a liquid crystal layer sandwiched between the two substrates; and the backlight module can evenly distribute light from a light source on the surface of the liquid crystal panel.

Traditionally, fluorescent lamps (Fluorescent Lamp) are mainly used as the light source in the backlight module. Among them, fluorescent lamps can be divided into Cold Cathode Fluorescent Lamp (CCFL) and Hot Cathode Fluorescent Lamp (Hot Cathode Fluorescent Lamp). Cold-cathode fluorescent lamps use cold-cathode electrodes instead of hot-cathode electrodes (such as tungsten filaments) that generate heat. Because cold-cathode fluorescent lamps can be started at low temperature, coupled with the characteristics of high efficiency and long life, it makes cold-cathode fluorescent lamps The lamp becomes the main backlight source in the liquid crystal display.

Please refer to Fig. 1, the cold-cathode fluorescent lamp 10 of the prior art is to comprise a glass tube 11, two ends of the glass tube 11 are respectively provided with an electrode 12, and the inner wall of the glass tube 11 is uniformly coated with a fluorescent layer (phosphor layer) 13. The glass tube 11 is filled with mercury vapor and a mixed inert gas (such as a mixed gas of xenon and argon) as a discharge medium.

When energized, the electrode 12 is connected to an external power source to release electrons. The electrons are accelerated by the electric field and collide with the discharge medium inside the glass tube 11, making the discharge medium in an excited state, and then release ultraviolet light to return to the ground state. Wherein, the ultraviolet light released by the discharge medium will be absorbed by the fluorescent layer 13 inside the glass tube to emit visible light.

However, the brightness of the CCFL 10 is very sensitive to temperature. When cold start (cold start), the brightness of the CCFL 10 will be very weak at first, and then the brightness will gradually increase as the temperature of the lamp tube increases. Enhanced, it takes a while to show a stable brightness. Taking a 32-inch backlight module with 16 cold-cathode fluorescent lamps as an example, it takes about 60 minutes of warm-up time before the cold-cathode fluorescent lamps 10 can emit stable brightness. If the user watches a 60-minute serial drama as an example, when the user feels that the brightness of the display screen is not enough when it is just started, it may increase the brightness of the lamp manually (usually by increasing the operating current of the lamp. increase), but as the temperature of the cathode fluorescent lamp 10 gradually rises, the brightness gradually increases. After a period of time, the user will feel that the display screen is too bright, and needs to reduce the brightness again. In order to obtain proper screen brightness, the user has to adjust the brightness of the screen back and forth, which is really inconvenient.

Based on the above, how to provide a brightness adjustment method and device that can automatically adjust the brightness of the lamp tube to solve the problem of manual adjustment by the user is a major issue!

This shows that the above-mentioned existing device for adjusting the brightness of the lamp tube obviously still has inconvenience and defects in the adjustment method, product structure and use, and needs to be further improved urgently. In order to solve the above-mentioned problems, the relevant manufacturers have tried their best to find a solution, but no suitable design has been developed for a long time, and there is no suitable method and structure for general adjustment methods and products to solve the above-mentioned problems. , this is obviously a problem that relevant industry players are eager to solve. Therefore, how to create a new brightness adjustment method and device for automatically adjusting the brightness of the lamp tube is one of the current important research and development topics, and has also become a goal that the industry needs to improve.

In view of the above-mentioned existing defects in the brightness adjustment method and device for adjusting the brightness of the lamp tube, the inventor actively researches and innovates based on his rich practical experience and professional knowledge in the design and manufacture of such products for many years, and in conjunction with the application of theories. In order to create a new brightness adjustment method and device for automatically adjusting the brightness of the lamp tube, it can improve the general existing brightness adjustment method and device for adjusting the brightness of the lamp tube, making it more practical. Through continuous research, design, and after repeated trials and improvements, the present invention with practical value is finally created.

Contents of the invention

The main purpose of the present invention is to overcome the defects of the existing brightness adjustment method and device for adjusting the brightness of the lamp tube, and provide a new brightness adjustment method and device that can automatically adjust the brightness of the lamp tube. The technical problem to be solved is It solves the problem of manual adjustment by the user, and thus is more suitable for practical use.

The purpose of the present invention and the solution to its technical problems are achieved by adopting the following technical solutions. A brightness adjustment method according to the present invention is to adjust the brightness of at least one fluorescent lamp, which is characterized in that it includes the following steps: sensing a current value and a voltage value of the fluorescent lamp; according to the current value and the Obtaining a brightness value from the voltage value; comparing the brightness value with a target brightness value to obtain a comparison result; and adjusting the current value or the voltage value according to the comparison result.

The purpose of the present invention and its technical problems can also be further realized by adopting the following technical measures.

In the aforementioned brightness adjustment method, in the step of obtaining the brightness value according to the current value and the voltage value, the brightness value corresponding to the current value and the voltage value is searched in a memory table.

In the aforementioned brightness adjustment method, the memory table records the complex experimental brightness values corresponding to the complex experimental current values and the complex experimental voltage values of the fluorescent lamp.

In the aforementioned brightness adjustment method, in the step of obtaining the brightness value according to the current value and the voltage value, the corresponding brightness value is calculated from the current value and the voltage value.

The purpose of the present invention and the solution to its technical problem also adopt the following technical solutions to achieve. A brightness adjusting device according to the present invention is for adjusting the brightness of at least one fluorescent lamp. The brightness adjusting device includes: a driving unit for generating a power signal to drive the fluorescent lamp; and a control unit for sensing Measure a current value and a voltage value of the fluorescent lamp, and obtain a brightness value according to the current value and the voltage value, compare the brightness value with a target brightness value, and the control unit sends a control signal to the drive unit , the driving unit adjusts the current value or the voltage value of the fluorescent lamp.

The purpose of the present invention and its technical problems can also be further realized by adopting the following technical measures.

In the aforementioned brightness adjustment device, the drive unit includes a switch circuit and a boost circuit, the switch circuit is electrically connected to the control unit, and is turned on and off according to the control signal output by the control unit , the step-up circuit is electrically connected with the switching circuit and generates the power signal by turning on and off the switching circuit.

In the aforementioned brightness adjustment device, the control unit searches for the brightness value corresponding to the current value and the voltage value in a memory table.

In the aforementioned brightness adjustment device, the memory table records the plural experimental current values and the plural experimental voltage values of the fluorescent lamp and the corresponding plural experimental brightness values.

In the aforementioned brightness adjustment device, the memory table is programmed into the control unit.

In the aforementioned brightness adjustment device, the control unit is a digital controller.

In the aforementioned brightness adjustment device, the control unit includes a digital controller, and the memory table is programmed into the digital controller.

In the aforementioned brightness adjustment device, the control unit includes a memory, and the memory table is recorded in the memory.

In the aforementioned brightness adjustment device, the control unit includes a sensing circuit, and the sensing circuit senses the current value and the voltage value of the fluorescent lamp.

In the aforementioned brightness adjustment device, the sensing loop includes a voltage sensing loop and a current sensing loop. Compared with the prior art, the present invention has obvious advantages and beneficial effects. It can be seen from the above technical solutions that the main technical content of the present invention is as follows: To achieve the above purpose, the present invention provides a brightness adjustment method, which is to adjust the brightness of at least one fluorescent lamp. The brightness adjustment method includes sensing a fluorescent lamp. A current value and a voltage value are used to obtain a brightness value according to the current value and the voltage value, and a comparison result is obtained by comparing the brightness value with a target brightness value, and the current value or the voltage value is adjusted according to the comparison result.

In order to achieve the above object, the present invention also provides a brightness adjustment device for adjusting the brightness of at least one fluorescent lamp. The brightness adjustment device includes a driving unit and a control unit. The drive unit generates a power signal to drive the fluorescent lamp, the control unit senses a current value and a voltage value of the fluorescent lamp, obtains a brightness value according to the current value and voltage value, and compares the brightness value with a target brightness value , the control unit sends a control signal to the drive unit, and the drive unit adjusts the current value or voltage value of the fluorescent lamp.

With the above-mentioned technical solution, the brightness adjustment method and device of the present invention have at least the following advantages: Based on the above, the brightness adjustment method and adjustment device of the present invention sense the current value and voltage value of the fluorescent lamp to calculate The current brightness value of the fluorescent lamp is used to adjust the brightness of the lamp tube. Compared with the prior art, the brightness adjustment method and the adjustment device of the present invention do not need a temperature sensing element to sense the temperature of the fluorescent lamp to adjust the brightness of the lamp tube. The brightness adjustment method and adjustment device of the present invention sense the current value and voltage value of the fluorescent lamp, and a current brightness value of the lamp can be obtained through calculation by the control unit or lookup in the memory table, and then can be obtained by comparing Adjust the current value and voltage value of the fluorescent lamp so that the brightness of the fluorescent lamp can be adjusted to the target brightness value of the fluorescent lamp. In this embodiment, the brightness adjustment method and the adjustment device can sense the current value and the voltage value of the fluorescent lamp at any time, so as to adjust the brightness value of the fluorescent lamp in real time. In this way, the material cost of the temperature sensing element can be saved.

To sum up, the present invention relates to a brightness adjustment method, which is to adjust the brightness of at least one fluorescent lamp. The brightness adjustment method includes sensing a current value and a voltage value of the fluorescent lamp, and according to the current value and the voltage value Obtain a brightness value, compare the brightness value with a target brightness value to obtain a comparison result, and adjust the current value or the voltage value according to the comparison result. The invention also discloses a brightness adjustment device. The material cost of the temperature sensing element can be saved. The present invention has the above-mentioned many advantages and practical value, and it has great improvement no matter in adjustment method, product structure or function, has significant progress in technology, and has produced easy-to-use and practical effects, and is better than the existing ones. The brightness adjustment method and device of the present invention have enhanced outstanding effects, are more suitable for practical use, and have extensive industrial application value, which is a novel, progressive and practical new design.

The above description is only an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention, it can be implemented according to the contents of the description, and in order to make the above and other purposes, features and advantages of the present invention more obvious and understandable , the following preferred embodiments are specifically cited below, and are described in detail as follows in conjunction with the accompanying drawings.

Description of drawings

FIG. 1 is a schematic diagram of a conventional cold cathode fluorescent lamp;

FIG. 2 is a schematic diagram of a brightness adjustment device according to a preferred embodiment of the present invention;

3 is a schematic diagram of a driving unit in a brightness adjustment device according to a preferred embodiment of the present invention;

FIG. 4 is a schematic diagram of a specific structure of a driving unit in a brightness adjustment device according to a preferred embodiment of the present invention;

5 is a schematic diagram of another specific configuration of the driving unit in the brightness adjustment device of the preferred embodiment of the present invention;

Fig. 6 is a schematic diagram of the memory table in the brightness adjustment device of the preferred embodiment of the present invention;

Fig. 7 is a schematic diagram of the brightness distribution of the lamp tube under different temperatures and different currents and voltages;

FIG. 8 is a schematic diagram of the brightness distribution of the lamp under different currents and different voltages; and

FIG. 9 is a schematic flowchart of a brightness adjustment method according to a preferred embodiment of the present invention.

10: Cold cathode fluorescent lamp 11: Glass tube

12: Electrode 13: Fluorescent layer

2: Brightness adjustment device 21, 21’: drive unit

211: Switching circuit 212, 212’: Boosting circuit

22: Control unit 221: Sensing circuit

222: memory table 223: controller

AD, X: point B _i : brightness value of experimental lamp

B ₁ , B ₂ , B ₃ , B ₄ , B ₅ , B ₆ , B ₁₂ , B _c : lamp brightness value

B _t : Target brightness value Ca: Capacitor

I _c , I ₁ : current value I _i : experimental current value

L: fluorescent lamp P _ia , P _ib : switch signal

S _c : Control signal S10-S70: Brightness adjustment steps

T ₁ , T ₂ , T ₃ , T ₄ , T ₅ : Lamp temperature Ta, Ta', Tb, Tb': Transistor

Tm, Tm': Transformer V _i : Experimental voltage value

V _c : V ₂ : voltage value

Detailed ways

In order to further explain the technical means and effects of the present invention to achieve the intended purpose of the invention, the specific implementation methods, methods, steps, and structures of the brightness adjustment method and device proposed according to the present invention will be described below in conjunction with the accompanying drawings and preferred embodiments. , features and their effects are described in detail below.

The method and device for adjusting brightness according to preferred embodiments of the present invention will be described below with reference to related drawings.

First, please refer to FIG. 2 to FIG. 7 to illustrate the brightness adjustment device of the preferred embodiment of the present invention.

As shown in FIG. 2 , the brightness adjustment device 2 includes a driving unit 21 and a control unit 22 . Wherein, the luminance adjusting device 2 adjusts the luminance of at least one fluorescent lamp. In this embodiment, the fluorescent lamp L is a cold cathode fluorescent lamp (Cold Cathode Fluorescent Lamp, CCFL) as an example. CCFLs are widely used. In addition to being used as backlights for liquid crystal display devices and light sources for some electronic devices (such as scanners), they can also be used as light sources for daily life lighting devices. Here, a cold-cathode fluorescent lamp is used as a backlight source of a liquid crystal display device as an example, and the number of fluorescent lamps L is not limited. In this embodiment, the brightness of one fluorescent lamp L is adjusted as an example. . In FIG. 2 , the control unit 22 may include a sensing circuit 221 , a memory table 222 , and a controller 223 , and details about the control unit 22 will be described later.

Please refer to FIG. 3 , the driving unit 21 generates a power signal to drive the fluorescent lamp L, wherein the driving unit 21 may include a switching circuit 211 and a boost circuit 212 . The switching loop 211 is electrically connected to the boosting loop 212 , and generates a power signal by switching the switching loop 211 on and off.

As shown in FIG. 4 , it is a specific composition of the driving unit 21. The boost circuit 212 of the driving unit 21 includes a transformer Tm and a capacitor Ca, and the switching circuit 211 includes two transistors (Ta, Tb). The transistors are respectively electrically connected to one end of the capacitor Ca, and the transistors (Ta, Tb) are respectively turned on and off according to the switching signals (Pia, Pib). The switching circuit 211 is electrically connected to the control unit 22 and is turned on and off according to a set of switching signals output by the control unit 22 . In addition, as shown in FIG. 5, the drive unit 21' can also have another configuration, that is, the boost circuit 212' includes a transformer Tm'; and the switching circuit 211' includes two transistors (Ta', Tb'). , the transistors (Ta', Tb') are respectively electrically connected to the primary coil side of the transformer Tm', and the transistors (Ta', Tb') are respectively turned on and off according to the switching signal.

Referring to FIG. 2 again, the control unit 22 is electrically connected to the driving unit 21. Generally speaking, the control unit 22 can be electrically connected to the driving unit 21 through a connection line (not shown in the figure). The control unit 22 generates at least one switching signal, and the driving unit 21 generates a power signal according to the switching signal. In addition, in this embodiment, part of the control circuit of the control unit 22 can be integrated into a digital controller (Digital Controller IC), so that the control unit 22 includes this digital controller, or the control unit 22 is directly integrated into a digital controller .

In addition, the sensing circuit 221 of the control unit 22 senses a current value Ic and a voltage value Vc of the fluorescent lamp L, wherein the current value Ic represents the intensity of the operating current passing through the fluorescent lamp L. In addition, because the voltage intensity passing through the fluorescent lamp L is a sine wave, the voltage value Vc is used to represent the root mean square voltage value (Root Mean Square Voltage) passing through the fluorescent lamp L. Wherein, the sensing loop 221 may include a current sensing loop and a voltage sensing loop, the current sensing loop may have a sensing element for sensing the current value Ic flowing through the fluorescent lamp L; The circuit can obtain the voltage value Vc of the fluorescent lamp L by sensing the voltage value of point X.

As shown in FIG. 6, it is a memory table (memory table) 222, which records complex experimental current values Ii and complex experimental voltage values Vi and their corresponding experimental lamp brightness values Bi. The data in the memory table is to pass different current intensities and different voltage intensities through the fluorescent lamp L to measure the luminance value produced by the fluorescent lamp L. For example, when the current value passing through the fluorescent lamp L is I1, and the voltage value passing through the fluorescent lamp L is V2, the measured brightness value of the fluorescent lamp tube is B12. After multiple experiments and measurements, the experimental values in the memory table 222 can be obtained, and lamps with different specifications can have different memory tables 222 .

Referring to Fig. 2, the memory table 222 can be stored in many forms, for example, the memory table 222 can be burned into the controller 223 in the control unit 22, or there is a memory in the control unit 22, and the memory table 222 is recorded in in memory. In this embodiment, the memory table 222 is burned into a memory as an example, and the controller 223 in the control unit 22 is electrically connected to the memory memory recorded with the memory table 222, wherein the controller 223 is a Digital Controller.

When the control unit 22 senses that the current value and the voltage value passing through the fluorescent lamp L are Ic, Vc, the control unit 22 can search the memory table 222 for the corresponding current value Ic and voltage value Vc through the controller 223. A lamp brightness value Bc. Of course, if the experimental data in the memory table 222 is calculated to obtain a closest formula, and then this formula is used to represent the mutual correspondence between the current value, the voltage value and the brightness value of the lamp tube, the formula can be directly Commits to the controller 223 to perform the calculations. After sensing, the control unit 22 can substitute the current value Ic and the voltage value Vc into the formula to calculate a corresponding brightness value Bc. In this way, a memory is not needed to record the data of the memory table 222 .

After the control unit 22 obtains a luminance value Bc, it compares the luminance value Bc with a target luminance value Bt, wherein the target luminance value Bt is the stable luminance of the fluorescent lamp L after it is turned on. After comparison, if the brightness value Bc is equal to the target brightness value Bt, the brightness adjustment will not be performed; if the brightness value Bc is greater than or smaller than the target brightness value Bt, the control unit 22 will send a control signal Sc to the drive unit 21 to drive The unit 21 adjusts the current value Ic or the voltage value Vc of the fluorescent lamp L to adjust the brightness value of the lamp tube to the target brightness value Bt.

Please refer to Figure 7, which is a schematic diagram of the brightness distribution of the lamp tube under different temperatures and different currents and voltages, which can be drawn by using the experimental data of 222 in the memory table, where the lamp tube temperature T5>T4>T3>T2> T1; lamp brightness value B6<B5<B4<B3<B2<B1, and assume that the lamp is driven by a constant current (Ic) and the target lamp brightness is in the B2 area. As shown at point A in the figure, in the prior art, when the lamp tube is cold-started, because the temperature of the lamp tube is low (T1), the vapor pressure in the lamp tube is insufficient and the brightness is also low (B3). However, as the temperature of the lamp tube rises slowly, the brightness of the lamp tube will change slowly from point A to a brighter luminance point B (brightness of the lamp tube B2) and point C (brightness of the lamp tube B1), and finally Only then can the stable D point (brightness of the lamp tube B2) be reached.

In this embodiment, in order to avoid the above-mentioned problems and reduce the inconvenience for users to adjust the brightness of the lamp tube by themselves, the brightness adjustment device 2 shown in FIG. 2 can be used to change the current intensity and voltage intensity passing through the fluorescent lamp L. , so that the lamp brightness can be maintained at the target lamp brightness value Bt, so as to provide users with a stable and suitable lamp brightness.

As shown in FIG. 8 , assuming that the lamp is driven by a constant current (Ic) and the target lamp brightness is B2, the measured lamp voltage of the fluorescent lamp L is Vc. Then, according to the current value Ic and the voltage value Vc, the luminance value Bc of the current lamp tube can be obtained by looking up a memory table or using a formula to calculate. Then, compare whether the brightness value Bc is equal to the target lamp brightness value Bt, if the lamp brightness value Bc is equal to the target lamp brightness value Bt, then the lamp brightness does not need to be adjusted. If the lamp brightness value Bc is not equal to the target lamp brightness value Bt, the following two situations can be distinguished: the lamp brightness value Bc is greater than the target lamp brightness value Bt or Bc is smaller than the target lamp brightness value Bt. Assume that the fluorescent lamp L is driven by a constant current, so when the corresponding lamp brightness value Bc is greater than the target lamp brightness value Bt (for example, the brightness value of point C is Bc; and the block B2 is the range of the target brightness value Bt, that is To adjust from point C to point B or point D), you can increase the voltage through the lamp to reach point B in block B2, or reduce the brightness of the lamp to reach point D in block B2 point. Wherein, the control unit can select a mode with a small voltage variation for adjustment. In addition, when the corresponding lamp brightness value Bc is smaller than the target lamp brightness value Bt (for example, the brightness value of point B is Bc; and the B1 block is within the range of the target brightness value Bt, that is, to move from point B to point C) , then the voltage through the lamp tube can be reduced to reach the point C located in the B1 block.

In addition, the lamp can also be driven by a constant voltage, and the brightness of the lamp can be changed by changing the magnitude of the current. Of course, the current and voltage passing through the lamp tube can also be changed at the same time, so as to change the corresponding brightness value of the lamp tube. After adjustment, the voltage value and current value passing through the lamp tube can still be sensed repeatedly, so that the fluorescent lamp L can be kept at the target lamp tube brightness value Bt at any time.

Next, please refer to FIG. 9 to illustrate the brightness adjustment method of the preferred embodiment of the present invention.

In this embodiment, the brightness adjustment method is to adjust the brightness of at least one fluorescent lamp. The brightness adjustment method includes the following steps: sensing a current value and a voltage value of the fluorescent lamp (S10), and obtaining A brightness value (S30), comparing the brightness value with a target brightness value to obtain a comparison result (S50), and adjusting the current value or the voltage value according to the comparison result (S70).

Wherein, the above-mentioned brightness adjustment method has been described in the brightness adjustment device in the foregoing embodiments, and will not be repeated here. It should be noted that the brightness adjustment method of this embodiment can be executed at any time and in real time, because the temperature of the lamp tube will change with the environment or operating time, etc., and the characteristics of the current value and voltage value of the lamp tube will vary according to the temperature of the lamp tube. Therefore, it can be set to adjust the brightness of the lamp tube every fixed time, so that the brightness of the fluorescent lamp L can be maintained at the target brightness value Bt.

Based on the above, according to the brightness adjustment method and adjustment device of the present invention, the current value and voltage value of the fluorescent lamp are sensed to calculate the current brightness value of the fluorescent lamp to adjust the brightness of the lamp tube. Compared with the prior art, the brightness adjustment method and the adjustment device of the present invention do not need a temperature sensing element to sense the temperature of the fluorescent lamp to adjust the brightness of the lamp tube. The brightness adjustment method and adjustment device of the present invention sense the current value and voltage value of the fluorescent lamp, and a current brightness value of the lamp can be obtained through calculation by the control unit or lookup in the memory table, and then can be obtained by comparing Adjust the current value and voltage value of the fluorescent lamp so that the brightness of the fluorescent lamp can be adjusted to the target brightness value of the fluorescent lamp. In this embodiment, the brightness adjustment method and the adjustment device can sense the current value and the voltage value of the fluorescent lamp at any time, so as to adjust the brightness value of the fluorescent lamp in real time. In this way, the material cost of the temperature sensing element can be saved.

The above description is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. Anyone familiar with this field Those skilled in the art, without departing from the scope of the technical solution of the present invention, may use the technical content disclosed above to make some changes or modify them into equivalent embodiments with equivalent changes, but as long as they do not depart from the technical solution of the present invention, the Technical Essence Any simple modifications, equivalent changes and modifications made to the above embodiments still fall within the scope of the technical solution of the present invention.

Claims (14)

1. A brightness adjustment method is to adjust the brightness of at least one fluorescent lamp, characterized in that it comprises the following steps: sensing a current value and a voltage value of the fluorescent lamp; obtaining a brightness value according to the current value and the voltage value; comparing the brightness value with a target brightness value and obtaining a comparison result; and The current value or the voltage value is adjusted according to the comparison result. 2. The brightness adjustment method according to claim 1, wherein the step of obtaining the brightness value according to the current value and the voltage value is to search for the current value and the voltage value in a memory table corresponding to the brightness value. 3. The brightness adjusting method according to claim 2, wherein said memory table records the complex experimental brightness values corresponding to the complex experimental current values and the complex experimental voltage values of the fluorescent lamp. 4. The brightness adjustment method according to claim 1, wherein in the step of obtaining the brightness value according to the current value and the voltage value, the corresponding value is calculated from the current value and the voltage value Brightness value. 5. A brightness adjusting device for adjusting the brightness of at least one fluorescent lamp, the brightness adjusting device comprising: a drive unit that generates a power signal to drive the fluorescent lamp; and A control unit senses a current value and a voltage value of the fluorescent lamp, obtains a brightness value according to the current value and the voltage value, compares the brightness value with a target brightness value, and sends out a The control signal is sent to the drive unit, and the drive unit adjusts the current value or the voltage value of the fluorescent lamp. 6. The brightness adjustment device according to claim 5, wherein the driving unit comprises a switching circuit and a boost circuit, the switching circuit is electrically connected to the control unit, and according to the control unit The output control signal is turned on and off, and the boost circuit is electrically connected to the switching loop to generate the power signal by turning on and off the switching loop. 7. The brightness adjusting device according to claim 5, wherein the control unit searches a memory table for the brightness value corresponding to the current value and the voltage value. 8 . The brightness adjusting device according to claim 7 , wherein the memory table records the plural experimental current values and the plural experimental voltage values of the fluorescent lamp and the corresponding plural experimental brightness values. 9. The brightness adjusting device according to claim 7, wherein the memory table is programmed into the control unit. 10. The brightness adjusting device according to claim 5, wherein the control unit is a digital controller. 11. The brightness adjusting device according to claim 7, wherein the control unit comprises a digital controller, and the memory table is programmed into the digital controller. 12. The brightness adjusting device according to claim 7, wherein the control unit comprises a memory, and the memory table is recorded in the memory. 13. The brightness adjusting device according to claim 5, wherein the control unit comprises a sensing circuit, and the sensing circuit senses the current value and the voltage value of the fluorescent lamp. 14. The brightness adjustment device according to claim 13, wherein the sensing circuit comprises a voltage sensing circuit and a current sensing circuit.

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