KR101639387B1 - method and apparatus for compensating light - Google Patents

Abstract

When an illumination device including a white LED (light emitting device) and RGB (Red, Green, Blue) LED is driven according to a predetermined reference value, light emitted according to driving of the illumination device is sensed, And calculates the difference from the reference value. Then, it is determined whether the illumination apparatus is corrected based on the calculated difference value, and the reference value is selectively corrected according to the determination result.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

The present invention relates to a correction method, and more particularly, to a method and apparatus for correcting hue or color temperature of an illumination.

As a lighting device, various lighting means are used. One of them, a light emitting device (LED), is a semiconductor emitting light. These LEDs can be configured in series and parallel to create LED lighting, which can be done in many ways to create white lighting. The first is to make white light using the same white LEDs with the desired color temperature and color rendering index (CRI). The second method is to construct a white light using white LEDs having different color temperature and color rendering index, and then adjusting the brightness of each LED to produce a white light having a desired color temperature and a color rendering index. The third method is to mix white LEDs, blue LEDs, and red LEDs to form white light, and then adjust the brightness of each LED to produce a white light having desired color temperature and color rendering index. The fourth method is to make white light using only RGB LEDs, in which case white light can be made by further mixing white LEDs. The fourth method of making white light is a structure capable of producing full color illumination, and emotional lighting capable of producing illumination according to human emotions can be constructed using the structure.

Because the LEDs exhibit slightly different characteristics from one LED to the next according to their own characteristics, different types of illumination can be produced when the LEDs are composed of lights. The characteristics of the LEDs vary depending on the surrounding environment such as temperature, humidity, etc., so that the light that has already been made may be changed, and the color temperature and the color rendering index,

Accordingly, there is a technique of measuring the ambient temperature and correcting the color temperature by adjusting the brightness of a white LED or other non-white LED having a different color temperature in response to the change of the color temperature of the LED according to the change of the ambient temperature. However, conventional techniques are mainly limited to white illumination.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an illumination correction method and apparatus for minimizing changes in LED light according to the surrounding environment and time.

Another object of the present invention is to provide an illumination correction method and apparatus capable of always providing homogeneous illumination.

According to an aspect of the present invention, there is provided a method of correcting an illumination device, the method comprising: detecting light emitted according to driving of the illumination device, detecting a light including RGB (Red, Green, Blue) Generating data; Converting the sensed data into a measured color coordinate value corresponding to a color coordinate; Calculating a difference value between a measured color coordinate value corresponding to the sensed data and a reference color coordinate value used in driving the lighting apparatus; And correcting the reference color coordinate value based on the calculated difference value.

According to another aspect of the present invention, there is provided an illumination correction apparatus comprising: a sensing unit for sensing light emitted according to driving of the illumination device and generating sensing data including RGB (Red, Green, Blue) values corresponding thereto; And a correction unit for correcting a reference color coordinate value corresponding to a color coordinate used in driving the illumination device using the sensed data. Wherein the correction unit includes a conversion module that converts the sensed data into a measured color coordinate value corresponding to the color coordinate; A calculation module for calculating a difference between a measured color coordinate value corresponding to the sensed data and a reference color coordinate value used for driving the illuminator; And a correction module for correcting the reference color coordinate value based on the calculated difference value.

According to an embodiment of the present invention, a color coordinate value is composed of x, y, and z, and the difference value is a difference between an x value of a measured color coordinate value corresponding to the sensed data and an x value of the reference color coordinate value, A difference value between a y value of a measured color coordinate value corresponding to the sensed data and a y value of the reference color coordinate value is a second difference value, a z value of a measured color coordinate value corresponding to the sensed data, and the difference value of the z value may include the third difference value.

According to the embodiment of the present invention, whatever kind of LEDs such as a white LED (Warm LED, Cool LED) and RGB (Red, Green, Blue) LEDs are used, It is possible to maintain the quality of the light which is not changed constantly.

1 is a diagram illustrating a structure of a lighting apparatus according to an embodiment of the present invention.
FIG. 2 is an exemplary view illustrating a positional relationship between a lighting unit and an illumination sensing unit according to an embodiment of the present invention.
3 is a diagram illustrating the structure of an illumination correcting unit and an illumination driving unit according to an embodiment of the present invention.
FIG. 4 is a flow chart illustrating an illumination correction method according to an embodiment of the present invention.
5 is a flowchart illustrating an error checking process in a correction method according to an embodiment of the present invention.
6 is a flowchart illustrating a correction process in the correction method according to the embodiment of the present invention.
7 is an exemplary diagram showing the chromaticity diagram of sensed data measured during driving of the illumination.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Throughout the specification, when an element is referred to as "comprising ", it means that it can include other elements as well, without excluding other elements unless specifically stated otherwise.

Hereinafter, an illumination correcting apparatus and method according to an embodiment of the present invention will be described with reference to the drawings.

1 is a structural view of a lighting apparatus according to an embodiment of the present invention.

1, a lighting apparatus 10 according to an embodiment of the present invention includes a power supply unit 11, a reference value storage unit 12, an illumination unit 13, an illumination driving unit 14, and a correction unit 15, , And a sensing unit (16).

The power supply unit 11 converts an AC power input into a DC power and converts the DC power into a voltage level for illumination driving. Here, a voltage level for driving a LED (light emitted device) is converted and supplied.

The reference value storage unit 12 stores a plurality of reference values corresponding to a color temperature and a color of a required illumination, and stores, for example, x, y, and z reference values. The reference value is a chromaticity coordinate indicating the chromaticity point on the chromaticity diagram, that is, an x, y, z coordinate value, and an xyz coordinate value on the chromaticity diagram indicates a color temperature and a color. The chromaticity point on the chromaticity diagram can be designated according to the required color temperature and color, and the xyz coordinate value corresponding to the designated chromaticity point is set as the reference value and stored in the reference value storage unit 12. [

The illumination driving unit 14 drives the illumination unit 13 based on the voltage supplied to the power supply unit 11 and drives the illumination unit 13 based on the reference value stored in the reference value storage unit 12 in detail.

The sensing unit 16 senses light emitted from the illuminating unit 13 and outputs corresponding sensing data. The sensed data includes RGB (Red, Green, Blue) data of the sensed light. For this, the sensing unit 16 may be formed of an RGB color sensor, and the RGB data may include an R value corresponding to the R component corresponding to the light emitted from the illumination unit 13, a G value corresponding to the G component, And the B value including the B value.

The illumination correcting unit 15 corrects the light of the LED so as not to deviate from the reference value based on the difference between the sensed data provided from the sensing unit 16 and the reference values used when the illumination unit 13 is driven.

The illumination unit 13 includes a plurality of LEDs having different color temperatures and color rendering indexes. The plurality of LEDs includes a white LED and an RGB LED, and illuminates light according to the user's demand. Here, the RGB LEDs indicate the R LED, the G LED, and the B LED. Here, the illuminating unit 13 is exemplified as including a white LED and an RGB LED, but is not limited thereto.

FIG. 2 is an exemplary view illustrating a positional relationship between a lighting unit and an illumination sensing unit according to an embodiment of the present invention.

The illumination unit 13 according to the embodiment of the present invention includes an RGB LED and a white LED, as illustrated in FIG. 2, wherein the white LED may include a warm white / cool white LED have. The RGB LED and the white LED form one illumination LED 131, and the illumination unit 13 may include a plurality of illumination LEDs.

The illumination sensing unit 16 for sensing the light emitted from the illumination unit 13 should be positioned at a position where light from the illumination unit 13 can be sufficiently received. The light sensing part 16 may be positioned on the diffusion plate 17 so as to correspond to the direction in which the light is emitted from the illumination part 13. [ In this case, divergent light from the illumination unit 13 is sensed by the illumination sensing unit 16, and the illumination sensing unit 16 receives the light from the illumination unit 13 by the diffusion plate 17, It is possible to measure more accurately. A power supply line and a signal line may be formed in the diffusion plate 17. [

The LED lighting apparatus 10 according to an embodiment of the present invention having such a structure emits illumination having a desired color temperature and hue, and the state of light emitted according to a predetermined period is measured and corrected.

To this end, the illumination correction unit 15 corresponding to the correction apparatus according to the embodiment of the present invention has the following structure.

3 is a diagram showing the structure of the illumination correcting unit 15 and the illumination driving unit 14 according to the embodiment of the present invention.

3, the illumination correction unit 15 according to the embodiment of the present invention includes a reception module 151, a conversion module 152, a difference value calculation module 153, and a correction module 154 .

The receiving module 151 receives the sensing data (RGB data) transmitted from the sensing unit 16, and the converting module 152 converts the received sensing data into a reference value form.

In the embodiment of the present invention, the sensing data includes RGB data, and the RGB data represents a value corresponding to each of R, G, and B measured by the RGB sensor of the sensing unit 16. The RGB sensor of the sensing unit 16 measures and outputs the respective values corresponding to the three colors R (red), G (green) and B (blue) from the input light, Value, and B value, and is called RGB data. Based on the measured RGB data, a chromaticity point representing the color temperature and color of the received light can be found from the chromaticity diagram, and thus the RGB data of the received light can be converted into an xyz value which is a reference value type corresponding to the chromaticity point found. The xyx value corresponding to the RGB data can be named the measured color coordinate value.

The conversion module 152 converts the sensing data into xyz values corresponding to the reference value type and outputs the xyz values. The difference value calculation module 153 calculates the difference value between the reference value used when the illumination unit 13 is driven and the xyz value provided from the conversion module 152 The difference value is calculated.

The correction module 154 corrects data for driving the illumination unit 13 based on the calculated difference value. And generates correction data based on the specifically calculated difference value and transmits it to the illumination driving unit 14. [ The correction data represents a value obtained by applying a difference value of xyz value corresponding to the RGB data measured in the reference value.

In addition, the correction module 154 according to the embodiment of the present invention may be configured to correct an error (e.g., an error) based on a difference value in order to prevent erroneous illumination correction from being caused by strong external stimuli (other illumination light, sunlight, Inspection will be carried out, which will be described later in more detail.

The illumination driving unit 14 drives the illumination unit 13 based on the reference value stored in the reference value storage unit 12 or drives the illumination unit 13 based on the correction data provided from the illumination correction unit 15. [ For this, as shown in FIG. 3, a drive data generation module 141 and a drive signal generation module 142 are included.

The drive data generation module 141 converts the reference value or the correction data into drive data for driving the illumination unit 13 substantially. The illumination unit 13 includes a plurality of LEDs, and includes RGB LEDs. The drive data is data for driving each of the RGB LEDs of the illumination unit 13, with the x, y, and z values corresponding to the reference value and the correction data being RGB values for R, G, and B values for illumination, respectively.

The drive signal generation module 142 generates a pulse width modulation (PWM) drive signal based on the drive data, and outputs the generated drive signal to the illumination unit 13. Specifically, a driving signal for driving the RGB LED of the illumination unit 13 is generated corresponding to the driving data RGB value, and an R driving signal for driving the R LED corresponding to the R value and a G LED corresponding to the G value are driven A G drive signal, and a B drive signal for driving the B LED corresponding to the B value. When the illumination unit 13 includes a white LED, a white driving signal for white illumination is generated according to the RGB value of driving data, and the white driving signal is output to the white LED.

The illumination correction unit 15 having such a structure automatically corrects the state of the light of the illumination unit 13 to maintain the ambient light and the LED light varying with time to maintain the most important function . The illumination correction unit 15 and the illumination driving unit 14 may be fabricated in a single chip form using an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Chip).

In the embodiment of the present invention, the xyz reference value or the measured color coordinate value xyz indicates the x, y, z coordinate values on the chromaticity diagram, and the RGB values indicate the R, G, and B values. And the xyz reference value used in driving the illumination may be referred to as "reference color coordinate value ".

Next, an illumination correction method according to an embodiment of the present invention will be described based on the illumination device 10 as described above.

FIG. 4 is a flow chart of a correction method of a lighting apparatus 10 according to an embodiment of the present invention.

An initial reference value for driving the illumination device 10 at a predetermined color temperature and color is set and stored in the reference value storage 12. The initial reference value can be arbitrarily designated by the user through an input interface or the like It may be preset at the time of manufacture.

The power supply unit 11 of the lighting apparatus 10 converts the AC power input to DC power and converts the voltage into a voltage level for driving LEDs and supplies the voltage to each component. 13). At this time, the illumination driving unit 14 drives the illumination unit 13 according to an initial reference value stored in the reference value storage unit 12. That is, the illumination driving unit 14 converts the initial reference value XYZ reference value into RGB values, generates a PWM signal corresponding to the converted RGB value, and outputs the PWM signal to the illumination unit 13 to drive the LED illumination.

4, the sensing unit 16 senses light emitted according to the driving of the illumination unit 13 and outputs RGB data as sensing data corresponding thereto, and the LED driving of the illumination unit 13 And senses the light emitted from the illumination unit 13 for a preset time after the start, and outputs corresponding RGB data (S100).

The RGB data obtained in accordance with the driving of the illumination unit 13 is transmitted to the illumination correction unit 15 and the illumination correction unit 15 converts the sensing data into xyz values corresponding to the reference value type in operation S110. Then, a difference value between the XYZ value and the initial reference value xyz reference value used in driving the illumination unit is generated. Specifically, the difference values? X,? Y, and? Z values are obtained by calculating the difference between the initial reference value XYZ reference value and the xyz value corresponding to the sensed data for each of x, y, and z (S130).

The illumination correcting unit 15 checks whether there is an error based on the obtained difference values? X,? Y, and? Z (S140).

5 is a flowchart illustrating an error checking process in a correction method according to an embodiment of the present invention.

Generally, since the change of light changes slightly in a small range, the values of DELTA X, DELTA Y and DELTA Z can vary greatly when a strong external stimulus (such as another illumination light, sunlight, or some LED failure) occurs. When such a phenomenon occurs, a difference (?) Equal to or larger than a predetermined tolerance value may be generated for? X,? Y, and? Z. In this case, the correction is delayed until the phenomenon disappears, . In the embodiment of the present invention, error checking is performed on the basis of difference values? X,? Y, and? Z corresponding to sensed data measured at the time of lighting driving.

As shown in FIG. 5, the illumination correcting unit 15 performs an operation of comparing the difference values? X,? Y, and? Z corresponding to the sensed data with preset tolerances. Specifically, first, the first difference value? X is compared with a predetermined first allowable value (S141), and when the? X value is equal to or greater than the first allowable value, in order to delay the operation for performing the illumination correction, A delay process of repeating the above steps (S100 to S140) for acquiring data is repeated a predetermined number of times (S142). For convenience of explanation, steps (S100 to S140) of detecting light of the illumination unit and calculating a difference value corresponding to the sensed data are collectively referred to as "sensing process ".

For example, the delaying process is repeated n times in the time period t, and when the value of DELTA X is equal to or greater than the first allowable value, the delaying process is performed.

On the other hand, when the first difference value? X is smaller than the first allowable value, it is determined whether the second difference value? Y is equal to or greater than the second allowable value (S143). If the second difference value? Y is equal to or greater than the second tolerance value, a delay process is performed (S144).

If the second difference value? Y is smaller than the second allowable value, it is determined whether the third difference value? Z is equal to or greater than the third allowable value (S145). If the third difference value? Z is equal to or greater than the third tolerance value, a delay process is performed (S146).

In this way, when any one of the difference values? X,? Y, and? Z is compared with the corresponding tolerance (first tolerance value, second tolerance value, third tolerance value) Light, failure of some LED, etc.), and delays the correction. Here, the first tolerance value, the second tolerance value, and the third tolerance value may be different values, or may be the same value.

If any one of the difference values DELTA X, DELTA Y and DELTA Z corresponding to the sensed data measured after the delaying process is equal to or greater than the corresponding tolerance value despite the delay process, (S150).

On the other hand, if the difference values DELTA X, DELTA Y, DELTA Z corresponding to the sensed data measured after the delay process are all less than the allowable values, a correction process is performed (S160).

FIG. 6 is a flowchart illustrating a correction process in a correction method according to an exemplary embodiment of the present invention, and FIG. 7 is an exemplary view illustrating sensed data measured in a lighting operation on a chromaticity diagram. .

As shown in FIG. 6, in the embodiment of the present invention, each correction is performed on x, y, and z based on the difference values? X,? Y, and? Z corresponding to the sensed data.

Before describing the correction, it is assumed that, for example, when the illumination unit 13 is driven to the initial reference value xyz, it is located at the initial position (a) of the chromaticity diagram, as in Fig. In this case, the color temperature and hue of the illuminating unit 13 may change with time depending on the influence of the surrounding environment. For example, as shown in FIG. 7, the color temperature and hue are changed within the change range R1 .

First, when the value of the first difference value? X is larger than "0" (S161) with respect to the difference values? X,? Y,? Z corresponding to the sensed data,? X (S162). That is, when the value of DELTA X is larger than 0, the measured value is the first position (b) within the change range R1 of FIG. 7, and the X value among the X, Y, Add the ΔX value. If the value of DELTA X is less than 0, DELTA X is subtracted from the X value of the XYZ reference value used at the time of illumination driving (S163).

Also, when the value of DELTA Y is larger than "0 ", the detection data is in the first position (b) within the change range R1, The Y value is added to the Y value in the X, Y, and Z reference values (S164, S165). When the value of DELTA Y is smaller than 0, DELTA Y is subtracted from the Y value of the XYZ reference value driven at the time of illumination (S166) when the sensing data is in the second position (c).

If the value of? Z is larger than 0, the value of? Z is added to the Z value among the X, Y, and Z reference values used at the time of illumination driving (S167, S168). If the value of? Z is less than 0, the value of? Z is subtracted from the value of the reference value of xyz used in driving the illumination (S169).

When the correction of the XYZ reference value driven in the illumination is completed as described above, the illumination unit 13 is driven again according to the corrected xyz reference value, as shown in FIG. That is, the illumination driving unit 14 converts the corrected XYZ reference value into an RGB value (S170), generates a PWM signal according to the RGB value, and drives the illumination unit 13 (S180).

Accordingly, when the color temperature or hue of the illuminated light changes as the surrounding environment changes with time, the illuminating unit is driven to correct the value for driving the illuminating unit as described above, thereby obtaining uniform illumination.

On the other hand, the correction method as described above can be periodically performed at a predetermined time period.

According to the embodiment of the present invention as described above, light emitted from the LED illumination is sensed using RGB sensors for various LED lights, not limited to white illumination, and light characteristics By automatically detecting and correcting the deviation, it is possible to minimize the variation of the light according to the surrounding environment and time, and as a result, it is possible to always provide homogeneous illumination.

The embodiments of the present invention are not limited to the above-described apparatuses and / or methods, but may be implemented through a program for realizing functions corresponding to the configuration of the embodiment of the present invention, a recording medium on which the program is recorded And such an embodiment can be easily implemented by those skilled in the art from the description of the embodiments described above.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, It belongs to the scope of right.

Claims (18)

In a method of calibrating a lighting device
Sensing light emitted according to driving of the illumination device and generating sensing data including RGB (Red, Green, Blue) values corresponding thereto;
Converting the sensed data into a measured color coordinate value corresponding to the color coordinate;
Calculating a difference between a measured color coordinate value corresponding to the sensed data and a reference color coordinate value used in driving the lighting apparatus; And
Comparing the difference value with a preset allowable value to determine whether or not to perform correction;
Correcting the reference color coordinate value based on the difference value when the difference value does not exceed the tolerance value;
Performing a correction delay process when the difference value exceeds the tolerance value
Lt; / RTI >
The determining whether or not the correction is performed may further include determining whether to perform correction based on the difference value newly obtained after performing the correction delay process,
Wherein the step of correcting the reference color coordinate value comprises: if the color coordinate value is x, y, z, the difference value includes a first difference value, a second difference value, and a third difference value, Value, y value, and z value based on the first difference value, the second difference value, and the third difference value, respectively. The method of claim 1, wherein
Wherein the first difference value is a difference value between an x value of a measured color coordinate value corresponding to the sensed data and an x value of the reference color coordinate value,
Wherein the second difference value is a difference value between a y value of a measured color coordinate value corresponding to the sensed data and a y value of the reference color coordinate value,
Wherein the third difference value is a difference value between the z value of the measured color coordinate value corresponding to the sensed data and the z value of the reference color coordinate value. delete The method according to claim 1,
The step of determining whether or not to perform the correction
Comparing the first difference value, the second difference value, and the third difference value with a corresponding first tolerance value, a second tolerance value, and a third tolerance value, respectively; And
Determining that correction is not performed when any one of the first difference value, the second difference value, and the third difference value exceeds a corresponding allowable value
/ RTI > The method of claim 4, wherein
The step of determining whether or not to perform the correction
Determining that correction is to be performed when the first difference value, the second difference value, and the third difference values do not exceed the respective allowable values. 5. The method of claim 4,
Wherein the first tolerance, the second tolerance, and the third tolerance are equal to each other. The method of claim 4, wherein
The step of performing the delaying step
Calculating a difference value by obtaining the sensed data during a predetermined period, and comparing the calculated difference value with a corresponding allowable value, the method comprising: The method of claim 7, wherein
The step of performing the delaying step may include a step of performing a correction operation when any one of the first tolerance value, the second tolerance value, and the third tolerance value acquired exceeds the corresponding tolerance value, And terminates the illumination correction process. The method of claim 4, wherein
The step of correcting the reference color coordinate value
Adding or subtracting the first difference value from the x value of the reference color coordinate value;
Adding or subtracting a second difference value from a y value of the reference color coordinate value; And
Adding or subtracting the third difference value from the z value of the reference color coordinate value
/ RTI > The method of claim 9, wherein
When the first difference value, the second difference value, and the third difference value are greater than "0 ", the correction for adding the difference value is performed,
And performs a correction to subtract the difference value when the first difference value, the second difference value, and the third difference value are less than "0 ". In a device for calibrating a lighting device
A sensing unit sensing light emitted according to driving of the illumination device and generating sensed data including RGB (Red, Green, Blue) values corresponding thereto; And
And a correction unit for correcting a reference color coordinate value corresponding to a color coordinate used in driving the illumination device using the sensed data,
Lt; / RTI >
The correction unit
A conversion module for converting the sensed data into a measured color coordinate value corresponding to the color coordinate;
A calculation module for calculating a difference value between a measured color coordinate value corresponding to the sensed data and a reference color coordinate value used in driving the illumination device;
Correcting the reference color coordinate value based on the calculated difference value when the difference value does not exceed the tolerance value and correcting the reference color coordinate value based on the calculated tolerance value, A correction module for determining whether to perform correction on the basis of a difference value newly obtained after performing the correction delay process,
/ RTI >
The correction module corrects the x value, y value, and z value of the reference color coordinate value based on the first difference value, the second difference value, and the third difference value, respectively, when the color coordinate value is x, y, , An illumination correction device. The method of claim 11, wherein
Wherein the first difference value is a difference value between an x value of a measured color coordinate value corresponding to the sensed data and an x value of the reference color coordinate value and the second difference value is a y value of a measured color coordinate value corresponding to the sensed data Wherein the third difference value is a difference value between the z value of the measured color coordinate value corresponding to the sensed data and the z value of the reference color coordinate value. The method of claim 11, wherein
Wherein the correction delay process is performed by repeating the process of acquiring the sensed data during a predetermined period to calculate a difference value and comparing the calculated difference value with a corresponding allowable value. delete 12. The method of claim 11,
Wherein the correction module compares the first difference value, the second difference value, and the third difference value with a corresponding first tolerance value, a second tolerance value, and a third tolerance value, 3 < / RTI > difference value does not exceed the corresponding allowable value. The method of claim 11, wherein
The correction module
If one of the first difference value, the second difference value and the third difference value is larger than "0", the correction for adding the first difference value from the x value of the reference color coordinate value, the correction for adding the y value of the reference color coordinate value Performing a correction to add a second difference value, and a correction to add a third difference value from the z value of the reference color coordinate value,
A correction for subtracting the first difference value from the x value of the reference color coordinate value when one of the first difference value, the second difference value and the third difference value is smaller than "0 & A correction to subtract a second difference value from the z value of the reference color coordinate value, and a correction to subtract a third difference value from the z value of the reference color value. The method of claim 11, wherein
The sensing unit
An RGB value including an R value corresponding to the R component corresponding to the light emitted from the illumination device, a G value corresponding to the G component, and a B value corresponding to the B component, And a sensor for outputting the light. The method of claim 11, wherein
Wherein the illumination device comprises a white light emitting device (LED) and an RGB (Red, Green, Blue) LED.

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