JP6580080B2 - Light source driving apparatus and light source driving method - Google Patents

Description

  The present invention relates to a light source driving device and a light source driving method.

  As one of the dimming instruction signals for the light source driving device, there is a PWM (Pulse Width Modulation) signal, and a method of dimming the light source according to the duty ratio is known. On the other hand, an international standard called DALI (Digital Addressable Lighting Interface (registered trademark)) is mainly used as facility lighting control mainly in Europe. In addition, a method of inputting a control signal of 0 to 10 V as a dimming instruction signal and performing dimming according to the voltage value (analog dimming, 0-10 V dimming) is also known.

  The dimming instruction signal includes an instruction level (dimming instruction level), but the relationship between the instruction level and the brightness of the light source (light quantity, light source level) is not fixed, and the instruction level And the dimming level and the driving circuit. As an example of the relationship between the indication level and the dimming level, the dimming level decreases at a constant rate when the indication level decreases by a certain amount (relationship indicated by the log dimming curve), and the indication level and the dimming level are proportional Relationship (relationship indicated by a linear dimming curve).

  In order to correspond to a plurality of dimming instruction signals and a plurality of relations between the instruction level and the light quantity, it corresponds to each dimming instruction signal system, and further, a plurality of correspondence relations (indicating levels and dimming levels) A light control method capable of dealing with a plurality of drive circuits is required. In addition, it is necessary to provide switching means for selecting a dimming instruction signal, a dimming curve, and a drive circuit. For this reason, there is a problem that the number of parts increases and the light source driving device increases in size.

Japanese Patent Application Laid-Open No. 2015-173031

The technique described in Patent Document 1 can cope with PWM and DALI dimming instruction signals with one control unit (dimming control unit). However, a method corresponding to a plurality of light control curves and a plurality of drive circuits is not disclosed.
The present invention aims to solve such a problem, and a light source driving device capable of supporting a plurality of dimming instruction signals, a plurality of dimming curves, and a plurality of driving circuits with one control unit. The purpose is to provide.

The present invention for solving the above problems is a light source driver for driving the light source in response to the dimming instruction signal is inputted, whether the light control direction signal is a PWM dimming instruction signal, or DALI tone An instruction level generation unit that determines whether the signal is a light instruction signal and generates a dimming instruction level within a predetermined range, and adjusts from the dimming instruction level according to desired dimming curves included in a plurality of dimming curves. a dimming level generator for generating a light level, and generates a dimming signal corresponding to the dependent dimming signal curve driving circuit of the light source from the dimming level, the driving the dimming signal of the light source A light source driving device comprising a dimming signal generation unit for outputting to a circuit.

  ADVANTAGE OF THE INVENTION According to this invention, the light source drive device which can respond | correspond to the light control instruction | indication signal of a several system, a some light control curve, and a some drive circuit with one control part can be provided.

It is a figure which illustrates the whole structure of the illumination system which concerns on this embodiment. It is a functional block diagram which illustrates the composition of the control part with which the light source drive concerning this embodiment is provided. It is a graph which illustrates the light control curve concerning this embodiment. It is a figure which illustrates the structure of the light control table memorize | stored in the memory | storage part with which the light source drive device which concerns on this embodiment is provided. It is a graph which illustrates the light control signal curve concerning this embodiment. It is a figure which illustrates the structure of the light control signal table memorize | stored in the memory | storage part with which the light source drive device which concerns on this embodiment is provided. It is a flowchart which shows the light control process which concerns on this embodiment. It is a figure which illustrates the data structure of the lower limit point and upper limit point of the light control signal curve memorize | stored in the memory | storage part with which the light source drive device which concerns on the modification of this embodiment is provided. It is a figure for demonstrating the linear interpolation of the light control signal curve which concerns on the modification of this embodiment.

≪Overall structure≫
FIG. 1 is a diagram illustrating an overall configuration of a lighting system 1 according to this embodiment. The lighting system 1 includes a remote controller 10, a light source driving device 20, and a lighting device 30. The lighting device 30 includes a light source 301.

  The remote controller 10 is a controller with a dial (not shown) attached to a wall surface, for example, and outputs a dimming instruction signal including an instruction level corresponding to an angle at which the dial is turned to the light source driving device 20. The dimming instruction signal includes a PWM method and a DALI method. The instruction level of the PWM system has 0 to 65535 stages, and the DALI system has 0 to 254 stages. In either method, the instruction level 0 corresponds to power off.

  The light source driving device 20 receives the dimming instruction signal from the remote controller 10 and outputs a direct current corresponding to the instruction level included in the dimming instruction signal to the light source 301 so that the brightness according to the instruction level is obtained. The light source 301 is driven. The light source drive device 20 includes an interface circuit 201, a control unit 40, a storage unit 202, a drive circuit 203, and an AC / DC conversion unit 204.

  The interface circuit 201 converts the input dimming instruction signal into a serial signal and outputs the serial signal to the control unit 40. The dimming instruction signal is a PWM dimming instruction signal or a DALI dimming instruction signal. The interface circuit 201 is composed of, for example, an analog circuit, and converts a dimming instruction signal, which is a differential signal having a wide voltage range, into a serial signal corresponding to a microcomputer (a control unit 40 described later) and electrically insulates the interface circuit 201 Have

  The control unit 40 is configured by a microcomputer, for example, and outputs a dimming signal corresponding to the serial signal input from the interface circuit 201 to the drive circuit 203. The serial signal includes the instruction level of the PWM dimming instruction signal or the DALI dimming instruction signal, and the control unit 40 outputs the dimming signal according to the instruction level, the dimming curve, and the drive circuit. Output. The instruction level included in the serial signal is reflected in the duty ratio of the dimming signal. The configuration of the control unit 40 will be described in detail later with reference to FIG.

  The storage unit 202 may be a ROM (Read Only Memory) including a dimming table storage area 207 and a dimming signal table storage area 208, or a ROM included in a microcomputer constituting the control unit 40. It may be a form.

  The dimming table storage area 207 is a storage area for data in a table format that approximates a dimming curve, and includes a log dimming table 2071 that approximates a log dimming curve and a linear dimming table 2072 that approximates a linear dimming curve. And store. When other dimming curves are used, a table that approximates the dimming curves is provided. When the dimming curve is set when the lighting system 1 is installed, or when the dimming curve is changed during use, these dimming tables are changed. The dimming curve and the dimming table will be described later in detail with reference to FIGS. 3 and 4, respectively.

  The dimming signal table storage area 208 is a data storage area in a table format that approximates the correspondence (the dimming signal curve) between the dimming level and the duty ratio of the dimming signal, and includes a dimming signal table 2081. Yes. The dimming signal curve depends on the drive circuit 203, and one of the dimming signal tables 2081 is selected in accordance with the drive circuit 203 when the illumination system 1 is installed. Alternatively, a single dimming signal table 2081 may be rewritten according to the driving circuit 203. The dimming signal curve and dimming signal table will be described later in detail with reference to FIGS. 5 and 6, respectively.

The drive circuit 203 is a device that supplies a direct current corresponding to the light source 301 as a power source. By supplying a direct current corresponding to the duty ratio of the dimming signal input from the control unit 40, the brightness (light quantity) of the light source 301 changes.
The AC / DC conversion unit 204 is a device that converts AC power from a commercial power supply (not shown) into DC power and supplies the DC power to the drive circuit 203.

≪Configuration of control part≫
FIG. 2 is a functional block diagram illustrating the configuration of the control unit 40 included in the light source driving device 20 according to this embodiment. The control unit 40 includes an instruction level generation unit 41, a dimming level generation unit 42, and a dimming signal generation unit 43.

  The instruction level generation unit 41 determines whether the serial signal input from the interface circuit 201 is a signal based on the PWM dimming instruction signal or a signal based on the DALI dimming instruction signal. Further, the instruction level generation unit 41 acquires an instruction level included in the PWM dimming instruction signal or the DALI dimming instruction signal and outputs the instruction level to the dimming level generation unit 42. The instruction level generation unit 41 includes a signal determination unit 411, a DALI detection unit 412, a PWM detection unit 413, and a conversion unit 414.

  The signal determination unit 411 determines whether the serial signal is based on the PWM dimming instruction signal or the DALI dimming instruction signal, and outputs the PWM dimming information to the PWM detection unit 413 or receives the DALI command information. The data is output to the DALI detection unit 412. The DALI command information includes an address (for example, an identification number or group number of the light source driving device 20 in the illumination system 1 in which a plurality of light source driving devices 20 are connected to the remote controller 10), a command, and DALI dimming information.

The DALI detection unit 412 acquires DALI dimming information from the input DALI command information, and outputs the instruction level to the dimming level generation unit 42. The instruction level is a value from 0 to 254.
The PWM detector 413 measures the duty ratio of the input PWM dimming information, and when the duty ratio is 0%, the PWM level is 0, and when the duty ratio is 100%, the PWM level is 65535, and the converter 414 Output to.
The conversion unit 414 converts the input PWM level into an instruction level and outputs it to the dimming level generation unit 42.

  The dimming level generation unit 42 converts the instruction level into a dimming level. The dimming level is a value from 0 to 100. The conversion includes conversion based on a linear dimming curve and conversion based on a log dimming curve, but may be conversion based on another dimming curve.

  FIG. 3 is a graph illustrating a dimming curve according to the present embodiment. The horizontal axis is the instruction level, and the vertical axis is the dimming level. A graph indicated by a broken line is a linear dimming curve 51, and indicates that an instruction level of 0 to 254 is linearly converted to a dimming level of 0 to 100. A graph indicated by a solid line is a log dimming curve 52, which indicates that the indicated level of 0 to 254 is converted to a dimming level of 0 to 100 based on the exponential function curve. The log dimming curve 52 is a graph of a function represented by the equation (1), where n is an instruction level and X (n) is a dimming level. For each indication level increased by approximately 25, the dimming level doubles. Compared to the linear dimming curve 51, the log dimming curve 52 is close to the reaction degree of the human eye, and it is easy to perform dimming at a particularly low level.

  FIG. 4 is a diagram illustrating a configuration of a dimming table stored in the storage unit 202 included in the light source driving device 20 according to the present embodiment. FIG. 4A shows a log dimming table 2071 used when converting an instruction level to a dimming level based on the log dimming curve 52, and is composed of an instruction level column 611 and a dimming level column 612. Is done. Each record (row) indicates a dimming level based on the log dimming curve 52 corresponding to the instruction level. FIG. 4B shows a linear dimming table 2072 used when converting an instruction level into a dimming level based on the linear dimming curve 51, and is composed of an instruction level column 613 and a dimming level column 614. Is done. Each record indicates a dimming level based on the linear dimming curve 51 corresponding to the instruction level.

  Returning to the description of FIG. 2, the dimming signal generation unit 43 outputs a dimming signal having a duty ratio corresponding to the input dimming level to the drive circuit 203. The correspondence between the dimming level and the duty ratio of the dimming signal depends on the drive circuit 203 and can be indicated by a dimming signal curve.

FIG. 5 is a graph illustrating a dimming signal curve according to this embodiment. The horizontal axis represents the dimming level, and the vertical axis represents the duty ratio (%) of the dimming signal.
The dimming signal curve 56 indicated by a thick solid line corresponding to the drive circuit of the model A changes the dimming signal linearly from 40 to 70% when the dimming level is between 0 and 60, and the dimming level. Is 60 or more, the duty ratio of the dimming signal remains 70%.

  The lower limit value of the duty ratio is 40%, and the maximum value of the light control level that is the lower limit value is zero. The upper limit value of the duty ratio is 70%, and the minimum value of the light control level that is the upper limit value is 60. Hereinafter, regarding the lower limit value and the upper limit value, the lower limit point 56L is also referred to as (0, 40) and the upper limit point 56U is also referred to as (60, 70).

  In the dimming signal curve 57 indicated by a thin solid line corresponding to the drive circuit of the model B, the duty ratio of the dimming signal remains 30% when the dimming level is 0-20, and the dimming level is 20-20. Between 100, the duty ratio of the dimming signal varies linearly from 30 to 90%. The lower limit 57L is (20, 30), and the upper limit 57U is (100, 90).

  The dimming signal curve 58 indicated by the dotted line corresponding to the drive circuit of the model C has a dimming level between 30 and 80 while the duty ratio of the dimming signal remains 10% when the dimming level is between 0 and 30. Then, the duty ratio of the dimming signal changes linearly from 10 to 50%, and when the dimming level is 80 or more, the duty ratio of the dimming signal remains 50%. The lower limit 58L is (30, 10), and the upper limit 58U is (80, 50).

  FIG. 6 is a diagram illustrating a configuration of the dimming signal table 2081 stored in the storage unit 202 provided in the light source driving device 20 according to the present embodiment. The dimming signal table 2081 is data in a table format used when the dimming level is converted into the dimming signal based on the dimming signal curve 56, and the dimming level column 631 and the duty ratio of the dimming signal. It is composed of columns 632. Each record indicates the duty ratio (%) in the dimming signal based on the dimming signal curve 56 corresponding to the dimming level.

≪Dimming control processing≫
FIG. 7 is a flowchart showing the dimming control process according to the present embodiment. The dimming control processing of the light source driving device 20 will be described with reference to FIG.
In step S <b> 40, the interface circuit 201 generates a serial signal corresponding to the dimming instruction signal input from the remote controller 10 and outputs the serial signal to the signal determination unit 411 of the control unit 40.

≪Instruction level generation step≫
In step S41, the signal determination unit 411 determines whether the input serial signal is based on the PWM dimming instruction signal or the DALI dimming instruction signal. The DALI dimming instruction signal includes a Forward frame transmitted from the remote controller 10 to the light source driving device 20, and there is a predetermined pause period between the two Forward frames. The signal determination unit 411 determines whether the serial signal is based on the PWM dimming instruction signal or the DALI dimming instruction signal by analyzing the serial signal and pause period based on the forward frame.

In step S42, the signal determining unit 411 proceeds to step S43 when determining that the serial signal is based on the PWM dimming instruction signal, and proceeds to step S46 when determining that the serial signal is based on the DALI dimming instruction signal.
In step S43, the signal determination unit 411 that has determined that the serial signal is based on the PWM dimming instruction signal outputs the PWM dimming information to the PWM detection unit 413.

In step S <b> 44, the PWM detection unit 413 acquires the PWM level from the input PWM dimming information, and outputs the PWM level to the conversion unit 414.
In step S <b> 45, the conversion unit 414 converts the PWM level into an instruction level and outputs it to the dimming level generation unit 42. The PWM level is a value from 0 to 65535, the instruction level is a value from 0 to 254, and can be converted by multiplying the PWM level by 254 and dividing by 65535. Alternatively, the instruction level may be calculated using an 8-bit right shift process that has a lighter processing load than a normal division operation. That is, a value obtained by shifting right by 8 bits and dividing by 256 may be obtained, and when this value exceeds 254, the indication level may be calculated as 254.

In step S46, the signal determination unit 411 that has determined that the serial signal is based on the DALI dimming instruction signal outputs DALI command information to the DALI detection unit 412.
In step S <b> 47, the DALI detection unit 412 acquires DALI dimming information from the input DALI command information, and outputs the instruction level to the dimming level generation unit 42.

≪Dimming level generation step≫
In step S <b> 48, the dimming level generation unit 42 converts the instruction level input with reference to the dimming table into a dimming level, and outputs the dimming level to the dimming signal generation unit 43. A conversion method when the dimming table is the log dimming table 2071 (see FIG. 4A) will be described below.

The dimming level generation unit 42 rounds up the input instruction level to a value in the instruction level column 611 and converts it to a dimming level corresponding to the rounded-up instruction level. For example, if the instruction level is 107, it is rounded up to 125, which is the minimum value of 107 or more, and the light control level is set to 3.
The dimming level generation unit 42 may convert the instruction level into a dimming level by performing linear interpolation with a value in the log dimming table 2071. For example, if the instruction level is 180, the dimming level is set to 14 by linear interpolation between the instruction level 175 and 200. Even when the linear dimming table 2072 or another dimming table is used, the dimming level generation unit 42 can convert the instruction level into the dimming level by the same method.

≪Dimming signal generation step≫
In step S49, the dimming signal generation unit 43 generates a dimming signal having a duty ratio corresponding to the dimming level input with reference to the dimming signal table 2081 (see FIG. 6), and sends it to the drive circuit 203. Output. The method for calculating the duty ratio from the dimming level is the same as in step S48. However, if the light control level is 0, the duty ratio is calculated as 0%.

≪Modification≫
In the above embodiment, the dimming signal generation unit 43 refers to the dimming signal table 2081 and calculates the duty ratio of the dimming signal from the dimming level. A method in which the dimming signal generation unit 43 calculates the duty ratio from the lower limit point and the upper limit point instead of the dimming signal table 2081 will be described below.

  FIG. 8 is a diagram illustrating a data configuration of the lower limit point and the upper limit point of the dimming signal curve stored in the storage unit 202 included in the light source driving device 20 according to the modification of the present embodiment. FIG. 8A shows data indicating a lower limit point and an upper limit point of the dimming signal curve 56. The lower limit light control level 621, the lower limit light control signal duty ratio 622, the upper limit light control level 623, and the upper limit light control signal duty ratio 624 are arranged in this order.

  If the input dimming level is 0 or less, which is the dimming level 621 at the lower limit point, the dimming signal generation unit 43 calculates 40% as the duty ratio 622 of the dimming signal at the lower limit point. If the input dimming level is 60 or more, which is the dimming level 623 of the upper limit point, the dimming signal generation unit 43 calculates 70% which is the duty ratio 624 of the dimming signal of the upper limit point. If the input dimming level is between 0, which is the dimming level 621 of the lower limit, and 60, which is the dimming level 623 of the upper limit, the dimming signal generation unit 43 (0, 40) and (60, 70) is used for linear interpolation. For example, if the dimming level is 30, the dimming signal generation unit 43 calculates the duty ratio as 55%. However, if the light control level is 0, the duty ratio is calculated as 0%.

  FIG. 8B shows tabular data storing the lower and upper limit points of the three dimming signal curves (56 to 58). 5 of the drive circuit model 641, the dimming level 642 of the lower limit point, the duty ratio 643 of the dimming signal of the lower limit point, the dimming level 644 of the upper limit point, and the duty ratio 645 of the upper limit dimming signal Consists of two columns. Each record indicates a lower limit point and an upper limit point of the dimming signal curve. The method for calculating the duty ratio of the dimming signal from the dimming level is the same as in FIG.

  As described with reference to FIG. 8A, by using the lower limit point and the upper limit point of the dimming signal curve instead of the dimming signal table 2081, an effect of reducing the capacity of the storage unit 202 can be obtained. Further, as described with reference to FIG. 8B, by previously storing the lower limit point and upper limit point of a plurality of dimming signal curves in the storage unit 202, it is possible to rewrite the storage unit 202 for each drive circuit 203. The effect of reduction is obtained.

  FIG. 8 shows a method for calculating the duty ratio of the dimming signal from the dimming level by performing linear interpolation at the lower limit and upper limit of the dimming signal curve. This is because the dimming signal curve is flat on the left of the lower limit point and on the right of the upper limit point, and is almost straight between the lower limit point and the upper limit point. Is used to calculate the duty ratio. A dimming signal curve with few flat or straight portions may be linearly interpolated by dividing the dimming signal curve into small sections in a range where the dimming level is small.

FIG. 9 is a diagram for explaining linear interpolation of a dimming signal curve according to a modification of the present embodiment. The dimming signal curve 59 is a dimming signal curve corresponding to the drive circuit of the model D. Linear interpolation end points (59A to 59G) on the graph are end points of straight lines (line segments) to be linearly interpolated. In a range where the dimming level is small, the dimming level column 631 of the dimming signal table 2081 (see FIG. 6) is divided into fine sections and finely linearly interpolated.
The darker the human eye is, the higher the degree of response, so in the low dimming level range, the dimming level is divided finely and the interpolation interval is made finer, so that the interpolation error can be reduced and the increase in the capacity of the storage unit is suppressed. In addition, it is possible to facilitate dimming of dark light.

  When the dimming level generation unit 42 converts the instruction level to the dimming level using the linear dimming curve 51 in step S48, the conversion is performed with reference to the linear dimming table 2072 (see FIG. 4B). . For linear interpolation, the indication level may be converted by multiplying by 100 and then dividing by 254.

≪Effect≫
As described above, the dimming level generation unit 42 converts the instruction level output from the instruction level generation unit 41 into a dimming level with reference to the dimming table. Compared with the method in which the correspondence table of each instruction level and dimming level is stored in the storage unit 202 and referenced when the dimming level is calculated from each of the PWM dimming instruction signal and the DALI dimming instruction signal. In the invention, the capacity of the storage unit 202 can be reduced.

Further, when the user of the lighting system 1 performs dimming by switching a plurality of dimming curves, the reduction capacity is further increased. For example, in the case of two types of dimming instruction signals and three types of dimming curves, the related art requires a correspondence table of six instruction levels and dimming levels. However, in the present invention, it is sufficient if there are three dimming tables, the capacity of the storage unit 202 corresponding to the three dimming tables can be reduced, and the cost of the storage unit 202 or the microcomputer including the storage unit 202 can be reduced.
If the user does not switch the dimming curve, it is sufficient to provide only one dimming table, and the capacity of the storage unit 202 can be reduced.

  By changing the dimming table, it is possible to deal with dimming curves other than log dimming curves and linear dimming curves. In addition, for the dimming instruction signals other than PWM and DALI, the instruction level generating unit 41 responds to the dimming instruction signal, so that the instruction level of the dimming instruction signal is increased without increasing the dimming table. It is possible to convert to a dimming level corresponding to the dimming curve.

  The dimming signal generation unit 43 refers to the dimming signal table 2081 and outputs a dimming signal having a duty ratio corresponding to the instruction level to the drive circuit 203. The control unit 40 can cope with a plurality of drive circuits by changing the dimming signal table 2081 and can reduce development and manufacturing costs. For example, when mass producing the light source driving device, the control unit 40 can correct the variation of the direct current output from the driving circuit 203 due to the product variation (characteristic) of the component by changing the dimming signal table 2081. .

  As shown in FIG. 8, the capacity of the storage unit 202 can be reduced and the cost can be reduced by referring to the lower and upper limit points of the dimming signal curve instead of the dimming signal table 2081. In addition, as shown in FIG. 9, when linearly interpolating the dimming signal curve, in a range where the dimming level is low, linear interpolation is performed by dividing the dimming level into small sections to take into account the degree of human eye response. Thus, the duty ratio of the dimming signal can be calculated so as to reduce the error.

DESCRIPTION OF SYMBOLS 1 Illumination system 10 Remote control 20 Light source drive device 201 Interface circuit 202 Storage part 203 Drive circuit 204 AC / DC conversion part 207 Dimming table storage area 2071 Log dimming table 2072 Linear dimming table 208 Dimming signal table memory area 2081 Dimming Signal table 30 Illuminating device 301 Light source 40 Control unit 41 Instruction level generation unit 411 Signal determination unit 412 DALI detection unit 413 PWM detection unit 414 Conversion unit 42 Dimming level generation unit 43 Dimming signal generation unit 51 Linear dimming curve 52 Log dimming Light curve 56, 57, 58, 59 Light control signal curve 56L, 57L, 58L Lower limit point 56U, 57U, 58U Upper limit point

Claims (6)

A light source driving device that drives a light source in response to an input dimming instruction signal,
An instruction-level generation unit for generating a dimming instruction level in a predetermined range to determine whether the light control direction signal or a PWM dimming instruction signal, or a DALI light control direction signal,
A dimming level generation unit that generates a dimming level from the dimming instruction level according to a desired dimming curve included in a plurality of dimming curves ;
And it generates a dimming signal corresponding to the dependent dimming signal curve to the drive circuit of the light source from the dimming level comprises the dimming signal and the dimming signal is output to the drive circuit generator of the light source A light source driving device characterized by that.   The light source driving device according to claim 1, wherein the dimming level generation unit generates the dimming level with reference to a dimming table corresponding to the dimming curve.   The light source driving device according to claim 1, wherein the dimming signal generation unit generates the dimming signal with reference to a dimming signal table corresponding to the dimming signal curve.   The dimming signal generation unit generates the dimming signal by dividing and linearly interpolating the dimming level section corresponding to the lower limit point and the upper limit point of the dimming signal curve. Item 4. The light source driving device according to Item 1.   4. The light source driving device according to claim 3, wherein the dimming signal table is finely divided in a range where the dimming level is small. A light source driving method for driving a light source according to an input dimming instruction signal,
An instruction level generation step of generating a dimming instruction level in a predetermined range to determine whether the light control direction signal or a PWM dimming instruction signal, or a DALI light control direction signal,
A dimming level generation step of generating a dimming level from the dimming instruction level according to a desired dimming curve included in a plurality of dimming curves ;
And it generates a dimming signal corresponding to the dependent dimming signal curve to the drive circuit of the light source from the dimming level comprises the dimming signal and the driving circuit dimming signal generating step of outputting to the light source And a light source driving method.

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