KR20120067917A - Method and apparatus for compensating light - Google Patents

Abstract

PURPOSE: An illumination correction method and an apparatus using the same are provided to maintain quality of light by automatically compensating a changed amount of LED light according to time and a surrounding environment with respect to a reference value of initial LED light. CONSTITUTION: A lighting unit(13) comprises an RGB LED and a white LED. The white LED includes warm/cool white LEDs. A single illumination LED is formed with the RGB LED and the white LED. The lighting unit comprises a plurality of the illumination LEDs. An illumination sensor detects light emitted from the lighting unit. The illumination sensor is located on a diffusion plate for being corresponded to a direction of the light emitted from the lighting unit. The light emitted from the lighting unit is detected by the illumination sensor. The illumination sensor accurately measures the light using the diffusion plate.

Description

Method and apparatus for compensating light

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

Various lighting means are used as the lighting device, one of which is a light emitting device (LED) that emits light. These LEDs are configured in series and in parallel to create LED lights. There are many ways to create white lights. The first method is to create white light using the same white LEDs with the desired color temperature and color rendering index (CRI). The second method is to compose white light using white LEDs having different color temperature and color rendering index, and then adjust the brightness of each LED to make white lighting with desired color temperature and color rendering index. The third method is to create a white light having a desired color temperature and color rendering index by adjusting the brightness of each LED after mixing white LED, blue LED, and red LED properly. The fourth method is to create white light using only RGB LEDs, in which case the white LEDs can be further mixed to create white light. The fourth method of making white lighting is a structure capable of making full color lighting, and by using this, it is possible to construct an emotional lighting that produces lighting according to human emotion.

Since LEDs show slightly different characteristics for each LED according to their own characteristics, lighting with different levels may be produced when the lighting is composed of LEDs. Since the characteristics of the LED vary depending on the surrounding environment such as temperature and humidity, the lighting that is already made may vary, and as time passes, the color temperature and color rendering index that were initially configured when the lighting is changed may vary.

Accordingly, there is a technique of measuring the ambient temperature and correcting the color temperature by adjusting the luminance of the white LED or the non-white LED having a different color temperature with respect to the color temperature change of the LED according to the change of the ambient temperature. However, the prior art is mainly limited to white lighting.

The problem to be solved by the present invention is to provide an illumination correction method and apparatus for minimizing the change of the LED light with the environment and time.

In addition, the problem to be solved by the present invention is to provide an illumination correction method and apparatus that can always provide a homogeneous illumination.

The method according to the characteristics of the present invention for the above problem is a method for calibrating a lighting device, the sensing that detects the light emitted by the driving of the lighting device and includes a corresponding RGB (Red, Green, Blue) value Generating data; Converting the sensed data into a measured color coordinate value corresponding to the color coordinate; Calculating a difference value between a measured color coordinate value corresponding to the sensed data and a reference color coordinate value used when driving the illumination device; And correcting the reference color coordinate value based on the calculated difference value.

According to another aspect of the present invention, there is provided a lighting correcting apparatus, including: a sensing unit configured to sense light emitted by driving of the lighting apparatus and to generate sensing data including corresponding RGB (Red, Green, Blue) values; And a correction unit configured to correct the reference color coordinate value corresponding to the color coordinate used when driving the lighting device by using the sensed data. Wherein the correction unit converts the sensed data into measured color coordinate values corresponding to the color coordinates; 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 when driving the lighting device; And a correction module for correcting the reference color coordinate value based on the calculated difference value.

In the present invention having such a feature, the color coordinate value is composed of x, y, z, and the difference value is a difference value between the x value of the measured color coordinate value corresponding to the sensed data and the x value of the reference color coordinate value. The difference value, the difference between the y value of the measured color coordinate value corresponding to the sensed data and the y value of the reference color coordinate value is the second difference value, the z value of the measured color coordinate value corresponding to the sensed data, and the reference color coordinate value. The difference value of the z value may include a third difference value.

According to an embodiment of the present invention, whatever type of LEDs, such as white LEDs (warm LEDs, cool LEDs) and RGB (red, green, blue) LEDs, are used in the surrounding environment or time with respect to the reference value of the LED light initially configured at the time of manufacture. By automatically correcting the light change according to the LED light it is possible to maintain the quality of the light does not change all the time.

1 is a view showing the structure of a lighting apparatus according to an embodiment of the present invention.
2 is an exemplary view illustrating a positional relationship between an illumination unit and an illumination detection unit according to an exemplary embodiment of the present invention.
3 is a view showing the structure of the lighting correction unit and the lighting driver according to an embodiment of the present invention.
4 is a view showing the flow of the 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 exemplary embodiment of the present invention.
6 is a flowchart illustrating a correction process in a correction method according to an exemplary embodiment of the present invention.
FIG. 7 is an exemplary view illustrating sensing data measured when driving an illumination on a chromaticity diagram.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is said to "include" a certain component, it means that it can further include other components, except to exclude other components unless specifically stated otherwise.

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

1 is a structural diagram of a lighting device according to an embodiment of the present invention.

As shown in FIG. 1, the lighting device 10 according to the embodiment of the present invention includes a power supply unit 11, a reference value storage unit 12, an illumination unit 13, an illumination driver 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 supply and converts the power supply into a voltage level for driving lighting. In this case, a voltage level for driving a light emitted device (LED) is converted and supplied.

The reference value storage unit 12 stores a plurality of reference values corresponding to the color temperature and color of the illumination required, and stores, for example, x, y, and z reference values. The reference value is a color coordinate representing the chromaticity point on the chromaticity diagram, that is, x, y, z coordinate values, and the xyz coordinate value on the chromaticity diagram represents color temperature and 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 lighting driver 14 drives the lighting unit 13 based on the voltage supplied to the power supply unit 11, and specifically drives the lighting unit 13 based on the reference value stored in the reference value storage unit 12.

The sensing unit 16 detects light emitted from the driving unit 13 and outputs corresponding sensing data, and the sensing data includes RGB (Red, Green, Blue) data of the detected light. To this end, the sensing unit 16 may be an RGB color sensor, and the RGB data corresponds to an R value corresponding to an R component corresponding to light emitted from the illumination unit 13, a G value corresponding to a G component, and a B component. It is an RGB value including the B value.

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

The lighting unit 13 includes a plurality of LEDs having different color temperatures and color rendering indices. The multiple LEDs include white LEDs and RGB LEDs, and illuminate light to meet the needs of the user. Here, the RGB LEDs represent R LEDs, G LEDs, and B LEDs. Although the illumination part 13 is illustrated here as including a white LED and RGB LED, it is not necessarily limited to this.

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

As illustrated in FIG. 2, the lighting unit 13 according to the embodiment of the present invention includes an RGB LED and a white LED, and 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 light detecting unit 16 for detecting the light emitted from the lighting unit 13 should be located where the light from the lighting unit 13 can be sufficiently received. Since it may be made, the light detecting unit 16 may be positioned on the diffusion plate 17 so as to correspond to the direction in which light is emitted from the light unit 13. In this case, the light emitted from the lighting unit 13 is detected by the light detecting unit 16, and the light detecting unit 16 receives the light of the lighting unit 13 while being less affected by ambient light by the diffuser plate 17. You can measure more accurately. A power line and a signal line may be formed in the diffusion plate 17.

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

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

3 is a view showing the structure of the light compensator 15 and the light driver 14 according to an embodiment of the present invention.

As shown in FIG. 3, the illumination compensator 15 according to an exemplary embodiment of the present invention includes a receiving module 151, a conversion module 152, a difference value calculating 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 conversion 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 values 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 values corresponding to three colors, that is, R (red), G (green), and B (blue), from the input light, and outputs the R value, G, of the input light. Named RGB data including value and B value. Based on the measured RGB data, a chromaticity point representing the color temperature and the color of the received light may be found from the chromaticity diagram, and thus, the RGB data of the received light may be converted into a xyz value, which is in the form of a reference value corresponding to the found chromaticity point. The xyx value corresponding to the RGB data may be referred to as a measured color coordinate value.

The conversion module 152 converts the detected data into an xyz value corresponding to the reference value form, and outputs the difference value calculating module 153 to determine the xyz value provided from the conversion module 152 and the reference value used when the lighting unit 13 is driven. Calculate the difference.

The correction module 154 corrects data for driving the lighting unit 13 based on the calculated difference value. Specifically, correction data based on the calculated difference value is generated and transmitted to the lighting driver 14. The correction data represents a value obtained by applying a difference value of xyz values corresponding to RGB data measured to a reference value.

In addition, the correction module 154 according to an embodiment of the present invention is an error based on the difference value in order to prevent the wrong lighting correction is made by a strong stimulus (other lighting light, sunlight, failure of some LEDs, etc.) from the outside The test is performed, which will be described later in more detail.

The lighting driver 14 drives the lighting unit 13 based on the reference value stored in the reference value storage unit 12, or drives the lighting unit 13 based on the correction data provided from the lighting correcting unit 15. To this end, as shown in FIG. 3, the driving data generating module 141 and the driving signal generating module 142 are included.

The drive data generation module 141 converts the reference value or the correction data into the drive data for substantially driving the lighting unit 13. The lighting unit 13 includes a plurality of LEDs, and includes an RGB LED. The drive data are RGB values of R values, G values, and B values for illuminating the xyz values corresponding to the reference value or the correction data, and are data for driving the RGB LEDs of the illumination unit 13, respectively.

The drive signal generation module 142 generates a drive signal in the form of pulse width modulation (PWM) based on the drive data, and outputs the generated drive signal to the lighting unit 13. Specifically, a driving signal for driving the RGB LED of the lighting unit 13 is generated in response to the driving data RGB value, and the R driving signal for driving the R LED corresponding to the R value, and the 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 are generated and output. When the lighting unit 13 includes a white LED, a white driving signal for white illumination is generated according to the RGB value, which is driving data, and output as a white LED.

The lighting correction unit 15 having such a structure automatically corrects the state of the light of the lighting unit 13 to maintain a constant LED light that changes according to the surrounding environment and time, and thus the most essential function for producing an optimal LED light. Do this. The lighting compensator 15 and the lighting driver 14 may be manufactured and implemented in a single chip form using a field programmable gate array (FPGA) or an application specific integrated chip (ASIC).

In an embodiment of the present invention, the xyz reference value or the xyz value, which is the measured color coordinate value, represents x, y, z coordinate values on the chromaticity diagram, and the RGB value represents an R value, a G value, and a B value. The xyz reference value used when driving the lighting may be referred to as a "reference color coordinate value".

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

4 is a view showing a flow of a correction method of the lighting device 10 according to an embodiment of the present invention.

An initial reference value for driving the lighting device 10 at a predetermined color temperature and color is set and stored in the reference value storage unit 12. The initial reference value may be arbitrarily designated by the user through an input interface, not shown, or the like. It may be set in advance at the time of manufacture.

The power supply unit 11 of the lighting device 10 converts an AC power input into a DC power, converts the voltage level for driving the LED, and supplies the same to each component. According to the power supply, the light driving unit 14 is provided with a lighting unit ( 13). In this case, the lighting driver 14 drives the lighting unit 13 according to the initial reference value stored in the reference value storage unit 12. That is, the lighting driver 14 converts the XYZ reference value, which is an initial reference value, to an RGB value, generates a PWM signal corresponding to the converted RGB value, outputs the PWM signal to the lighting unit 13, and drives the LED lighting.

Accordingly, as shown in FIG. 4, the sensing unit 16 detects light emitted by the driving of the lighting unit 13 and outputs RGB data corresponding to the sensing data, and the LED driving of the lighting unit 13 is performed. After the start, the light emitted from the lighting unit 13 is sensed for a predetermined time and then outputs the corresponding RGB data (S100).

The RGB data obtained by driving the lighting unit 13 is transferred to the lighting correcting unit 15, and the lighting correcting unit 15 converts the sensing data into xyz values corresponding to the reference value type (S110). The difference between the XYZ value and the initial reference value xyz reference value used when driving the lighting unit is generated. Specifically, for each of x, y, and z, the difference between the initial reference value XYZ reference value and the xyz value corresponding to the sensed data is calculated, respectively, to obtain difference values ΔX, ΔY, and ΔZ (S130).

The lighting correction unit 15 checks whether there is an error based on the obtained difference values ΔX, ΔY, and ΔZ (S140).

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

In general, since the change of light is changed little by little in a small range, when strong external stimulus (other illumination light, sunlight, failure of some LEDs, etc.) occurs, the values of ΔX, ΔY, and ΔZ may change significantly. When this phenomenon occurs, a difference (Δ) above a predetermined allowable value may occur for ΔX, ΔY, and ΔZ. In such a case, the correction is delayed until the phenomenon disappears, and then a correction operation is performed after a certain period of time. It is preferable. According to an exemplary embodiment of the present invention, an error check is performed based on the difference values ΔX, ΔY, and ΔZ corresponding to the sensed data measured when driving the lighting.

As shown in FIG. 5, the illumination compensator 15 performs an operation of comparing the preset values with respect to the difference values ΔX, ΔY, and ΔZ corresponding to the sensed data, respectively. Specifically, first, when the first difference value ΔX is compared with a preset first allowable value (S141), and when ΔX is equal to or greater than the first allowable value, in order to delay an operation for performing illumination correction, detection according to driving of lighting is performed. A delay process of repeatedly performing the set number of times for obtaining data (S100 to S140) is performed (S142). For convenience of description, the steps of sensing the light of the lighting unit and calculating a difference value corresponding to the sensing data (S100 to S140) are collectively referred to as a “sensing process”.

For example, the delay process is performed by repeating the sensing process n times in a t time period, and when the ΔX value is greater than or equal to the first allowable value, the delay process is performed.

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

In addition, when the second difference value ΔY is smaller than the second allowable value, it is determined whether the third difference value ΔZ is greater than or equal to the third allowable value (S145). If the third difference value ΔZ is greater than or equal to the third allowable value, a delay process is performed (S146).

In this way, the difference values ΔX, ΔY, and ΔZ are respectively compared with the corresponding allowable values (first allowable value, second allowable value, and third allowable value), and when any one exceeds the corresponding allowable value, external stimulus (other illumination light, solar It is determined that an error phenomenon affected by light, a failure of some LEDs, etc. is occurring, and the correction is delayed. Here, the first tolerance value, the second tolerance value, and the third tolerance value may be different values, or may be the same value.

Although the delay process is performed, if any one of the difference values ΔX, ΔY, and ΔZ corresponding to the sensed data measured after the delay process is larger than the corresponding allowable value, it is determined that an error state is terminated without further performing the correction function. (S150).

On the other hand, if the difference values ΔX, ΔY, and ΔZ corresponding to the measured data after performing the delay process are all smaller than the allowable value, the correction process is performed (S160).

6 is a flowchart illustrating a calibration process in a calibration method according to an exemplary embodiment of the present invention, and FIG. 7 is an exemplary diagram illustrating sensing data measured when driving lighting on a chromaticity diagram. .

As shown in FIG. 6, in the exemplary embodiment of the present invention, respective corrections are performed on x, y, and z based on the difference values ΔX, ΔY, and ΔZ corresponding to the sensed data.

Before describing the correction, for example, suppose that the lighting unit 13 is driven at the initial reference value xyz value, as shown in FIG. 7, at the initial position ⓐ of the chromaticity diagram. In this case, the color temperature and the color of the lighting unit 13 may change with time due to the influence of the surrounding environment. For example, as shown in FIG. 7, the color temperature and the color change within the change range R1. Assume that

For the difference values ΔX, ΔY, and ΔZ values corresponding to the sensed data, first, when the value of the first difference value ΔX is greater than “0” (S161), ΔX at the X value constituting the XYZ reference value used when driving the illumination. Correction to add (S162). That is, when the value of ΔX is greater than 0, the measured value, that is, the sensing data is in the first position ⓑ within the change range R1 of FIG. Add the ΔX value. When the value of ΔX is less than 0, the ΔX value is subtracted from the X value of the XYZ reference value used when driving the light as the sensed data is in the second position ⓒ (S163).

In addition, correction is also performed for the value of the second difference value ΔY, and when ΔY is greater than "0", the detection data is in the first position (ⓑ) within the change range R1, and is used for driving lighting. The ΔY value is added to the Y value among the obtained XYZ reference values (S164, S165). When the value of ΔY is smaller than 0, the ΔY value is subtracted from the Y value of the XYZ reference value driven during illumination as the sensed data is in the second position (ⓒ) (S166).

In addition, correction is performed on the value of the third difference value ΔZ, and when ΔZ is greater than “0”, the ΔZ value is added to the Z value among the XYZ reference values used when driving the illumination (S167 and S168). If the value of ΔZ is less than 0, the ΔZ value is subtracted from the Z value of the xyz reference value used when driving the light (S169).

When the correction for the XYZ reference value driven in this manner is completed, as shown in FIG. 5, the illumination unit 13 is driven again according to the corrected xyz reference value. That is, the lighting driver 14 converts the corrected XYZ reference value into an RGB value (S170), generates a PWM signal according to the RGB value, and drives the lighting unit 13 (S180).

Therefore, when the color temperature or the color of the illuminated light changes as the surrounding environment changes over time, as described above, uniform illumination can be obtained by correcting a value for driving the lighting unit.

Meanwhile, the correction method as described above may be periodically performed at a set period of time.

According to an embodiment of the present invention as described above, for various LED lights not limited to the white light, using the RGB sensor to detect the light emitted from the LED light and the characteristics of the light at the initially set reference value using the color coordinates By automatically detecting and correcting the deviation, it is possible to minimize the change of light with the surrounding environment and time, and as a result, it is possible to always provide a 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)

How to calibrate a lighting device
Sensing the light emitted by the driving of the lighting 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 value between a measured color coordinate value corresponding to the sensed data and a reference color coordinate value used when the lighting apparatus is driven; And
Correcting the reference color coordinate value based on the calculated difference value
Including, the illumination correction method. The method of claim 1
Determining whether to perform correction by comparing the difference value with a preset tolerance value; And
If it is determined that the correction is not performed, performing a delay process of delaying the correction.
Further comprising, lighting correction method. The method of claim 2,
The color coordinate value consists of x, y, z
The difference is
The difference between the x value of the measured color coordinate value corresponding to the sensed data and the x value of the reference color coordinate value is a first difference value,
A second difference value between a y value of the measured color coordinate value corresponding to the sensed data and a y value of the reference color coordinate value;
The 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 is a third difference value.
Including, lighting correction method. The method of claim 3,
Determining whether the correction is performed
Comparing the first difference value, the second difference value, and the third difference value with corresponding first allowable values, second allowable values, and third allowable values, respectively; And
Determining that any one of the first difference value, the second difference value, and the third difference value does not perform correction exceeding a corresponding allowable value;
Including, the illumination correction method. The method of claim 4
Determining whether the correction is performed
And determining that the correction is to be performed when all of the first difference value, the second difference value, and the third difference value do not exceed a corresponding allowable value. The method of claim 4, wherein
And the first, second, and third tolerance values are the same. The method of claim 4
The step of performing the delay process
And a process of acquiring the sensed data for a predetermined period, calculating a difference value, and comparing the calculated difference value with a corresponding allowable value. The method of claim 7, wherein
The performing of the delay process may include performing a correction operation when any one of the acquired first allowable value, second allowable value, and third allowable value exceeds the corresponding allowable value despite repeating the predetermined number of strokes during the set period. Termination, lighting correction method. The method of claim 4
Correcting the reference color coordinate value
Adding or subtracting a first difference value from an 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 a third difference value from a z value of the reference color coordinate value
Including, the illumination correction method. The method of claim 9
When the first difference value, the second difference value, and the third difference value are greater than "0", a correction is performed to add a corresponding difference value;
And correcting the subtraction value when the first difference value, the second difference value, and the third difference value are smaller than "0". From the device that calibrates the lighting device
A detector configured to sense light emitted by the driving of the lighting device and to generate sensing data including RGB (Red, Green, Blue) values corresponding thereto; And
A correction unit for correcting a reference color coordinate value corresponding to the color coordinate used when driving the lighting device by using the sensed data
Including,
The correction unit
A conversion module for converting the sensed data into measured color coordinate values corresponding to the color coordinates;
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 when driving the lighting device;
A correction module for correcting the reference color coordinate value based on the calculated difference value
To include, lighting correction device. The method of claim 11, wherein
The correction module
And determining whether to perform the correction by comparing the difference value with a preset allowable value, and performing a delay process of delaying the correction if it is determined that the correction is not performed. The method of claim 12,
The delay process is to perform a predetermined number of times to repeat the process of acquiring the sensing data during the set period to calculate the difference value, and comparing the calculated difference value with a corresponding allowable value. The method of claim 11, wherein
The color coordinate value consists of x, y, z
The difference is
The difference between the x value of the measured color coordinate value corresponding to the sensed data and the x value of the reference color coordinate value is a first difference value,
A second difference value between a y value of the measured color coordinate value corresponding to the sensed data and a y value of the reference color coordinate value;
The 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 is a third difference value.
To include, lighting correction device. The method of claim 14,
The correction module compares the first difference value, the second difference value, and the third difference value with a corresponding first allowable value, second allowable value, and third allowable value, respectively; The lighting correction apparatus which determines that any one of 3 difference values does not perform the correction which exceeds the applicable tolerance value. The method of claim 14, wherein
The correction module
If one of the first difference value, the second difference value, and the third difference value is greater than "0", the correction is performed by adding the first difference value to the x value of the reference color coordinate value, and at the y value of the reference color coordinate value. Performing one of a correction for adding a second difference value and a correction for adding a third difference value from a z value of the reference color coordinate value,
If one of the first difference value, the second difference value, and the third difference value is smaller than "0", a correction is performed to subtract the first difference value from the x value of the reference color coordinate value, and the y value of the reference color coordinate value. And a correction for subtracting the second difference value from the second difference value, and a correction for subtracting the third difference value from the z value of the reference color coordinate value. The method of claim 11, wherein
The sensing unit
Located between the lighting device and the diffuser, an RGB value including an R value corresponding to the R component corresponding to the light emitted from the lighting device, a G value corresponding to the G component, and a B value corresponding to the B component. The illumination correction device which consists of a sensor to output. The method of claim 11, wherein
The lighting device comprises a white light emitting device (LED) and a red, green, blue (RGB) LED.

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