KR20110093354A - Led illuminator for feedback-controlling color temperature and method thereof - Google Patents

Abstract

PURPOSE: A color temperature feedback control type LED lamp and a control method thereof are provided to constantly maintain a color temperature of a set lamp by installing a color temperature detector. CONSTITUTION: A color temperature detector(102) detects the color temperature of a light source. A mode setting unit(104) sets the color temperature mode of the light source. A control unit(106) drives the light source in the color temperature mode set by the mode setting unit. The control unit controls to maintain the color temperature of the light source to the set color temperature in response to the color temperature detection signal through the color temperature detecting unit.

Description

Color temperature feedback control type LED lighting device and control method thereof. {LED Illuminator for Feedback-Controlling Color Temperature and Method about}

The present invention relates to an LED lighting apparatus and a control method thereof, and more particularly, to an LED lighting apparatus and a control method thereof, which are feedback-controlled to follow a set color temperature of the color temperature of the LED light source.

Recently, lighting devices using light emitting diodes (LEDs), which have been in the spotlight as next-generation light sources which are excellent in energy saving effect and can be used almost semi-permanently, are drawing attention.

The LED lighting device can be composed of a combination of multicolored light emitting diodes such as white, red, green, and blue, so that various colors can be expressed, thereby controlling emotional lighting.

Patent Publication No. 2009-73601 (White Light Emitting Device) discloses a technique for maintaining a constant color temperature of white light in response to ambient temperature. In this patent, it is difficult to control color temperature compensation for color temperature change factors other than temperature because the color temperature is controlled by detecting a change in ambient temperature through a temperature sensor. In addition, since the color temperature of the light source is not directly sensed, color temperature compensation due to temperature change in a state where the color temperature is converted due to other factors may be meaningless.

Patent Publication No. 2009-104587 (Lighting Lamp) discloses a technique for controlling the appropriate color temperature according to external factors such as temperature. This patent does not teach the technology of maintaining the color temperature of the light source to a predetermined color temperature by controlling the color temperature for emotional lighting adaptive to the season or the surrounding environment by measuring external factors such as external temperature, humidity, and illumination.

Various color temperature control techniques for other LED lighting devices are introduced.

Patent Publication No. 2009-41834 (Color temperature and illuminance lighting apparatus using a plurality of light sources) discloses a technology that can produce a variety of color temperature by varying the illuminance for each light source.

In Korean Patent Laid-Open Publication No. 2009-47285 (the color temperature control device and control method of the light emitting diode), the amount of the LED driving current according to the red, green, and blue ratios of the color temperature control pulse width control signals in order to maintain a constant brightness during color temperature control. A technique for controlling a power supply control pulse width control signal corresponding to

Patent Publication No. 2009-47323 (Color coordinate reproduction lighting apparatus) discloses a technique for controlling the LED by selecting the chromaticity and color temperature.

Korean Patent Laid-Open Publication No. 2009-132831 (Method Lighting Control Method and Apparatus) discloses a technology that can easily control emotional lighting by controlling different lightings with different color temperature and illuminance with one control command.

The color temperature control of the conventional LED lighting apparatus described above relates to general indoor lighting control or emotional lighting control, and the appearance of the LED lighting apparatus to be applied to a special lighting field such as an art field such as a studio or a stage lighting is required.

In the field where a special lighting such as a studio or a stage is required, it is still preferred to use a halogen lamp or a xenon lamp, which has been used for a long time, rather than LED lighting. In the field of video shooting or photography, color temperature control is very important for daylight lighting effect in indoor space or to produce the most natural color for human visual feeling.

Therefore, there was no choice but to prefer a conventional halogen lamp or xenon lamp that can be sensed for a long time rather than LED lighting that has not been mastered yet.

SUMMARY OF THE INVENTION An object of the present invention for solving the above problems is to provide an LED lighting device and a control method that can produce the lighting effect of a conventional filament heating lamp or a discharge lamp (hereinafter referred to as a classic lamp) in a special lighting field. There is.

Another object of the present invention is to provide an LED lighting device capable of controlling color temperature tracking corresponding to a color temperature lookup table for each model of a specific lamp maker and a control method thereof.

Still another object of the present invention is to provide an LED lighting device and a control method thereof, which are easy to use by lighting engineers in a special lighting field.

The apparatus of the present invention for achieving the above object comprises a light source composed of at least one LED, color temperature detection means for detecting the color temperature of the light source, mode setting means for setting the color temperature mode of the light source, and mode setting means. And a control unit for driving the light source in the set color temperature mode and controlling the color temperature of the light source to be constantly maintained at the set color temperature in response to the color temperature detection signal through the color temperature detection means.

In the present invention, the mode setting means may set the color temperature of at least one or more of tungsten incandescent lamp, fluorescent lamp, three wavelength fluorescent lamp, halogen lamp, sodium lamp and xenon lamp. In addition, the mode setting means may set the color temperature of at least one or more light conditions of incandite, warm light, cool light, day light, and cool day light. In addition, the mode setting means may set the color temperature of at least one lamp model of the color temperature lookup table for each lamp model of the lamp manufacturer. In addition, the mode setting means may be set to at least one or more color temperatures of the color temperature table.

Preferably, the controller of the present invention variably adjusts the pulse width ratio of the pulse width control signal generated by the color temperature control data in response to the color temperature detection signal. The pulse width variable may include color temperature and brightness control factors.

The control method of the present invention sets the color temperature of the LED light source, drives the LED light source with the set color temperature, detects the color temperature of the driven LED light source, compares the detected color temperature with the set color temperature, and compares the detected color temperature with the result. If is different from the set color temperature, the driving of the LED light source is controlled to follow the set color temperature.

LED lighting device according to an embodiment of the present invention is to create the atmosphere of the classic lamp of the filament heating method or the discharge method of the filament heating method, such as tungsten lamp, fluorescent lamp, halogen lamp, xenon lamp in the stage lighting lamp as the LED light source The color temperature of the set lamp can be kept constant at all times even in a color temperature change environment such as temperature, humidity, power supply fluctuation or initial lighting.

1 is a block diagram of the LED lighting apparatus according to the present invention.
2 is a view showing an example of a color temperature setting screen by the color temperature table and the classic lamp icon of the LED lighting apparatus according to the present invention.
Figure 3 is a view showing an example of the color temperature setting screen by the color temperature table of the LED lighting apparatus according to the present invention.
3 is a view showing the illumination state of the white LED by the color temperature control.
Figure 4 is a waveform diagram showing an example of the LED color temperature control signal of the LED lighting apparatus according to the present invention.
5 and 6 are a flow chart for explaining the lamp color temperature tracking feedback control program according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in more detail with reference to the accompanying drawings. As the inventive concept allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to the specific disclosed form, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

1 shows a block diagram of an LED lighting apparatus according to the present invention.

Referring to FIG. 1, the LED lighting device 100 includes a color temperature detecting unit 102, a mode setting unit 104, a control unit 106, a power supply unit 108, a switch 110, 112, 114, and 116, a white LED. The driving means 118, the green LED driving means 120, the red LED driving means 122, the blue LED driving means 124, LED lamp 130 is included.

The color temperature detecting unit 102 is configured with a normal color temperature sensor to detect the color temperature of the LED light source 130.

The mode setting means 104 displays a main menu such as a color temperature table setting mode / classic lamp setting mode / color temperature lookup table setting mode / light marking condition setting mode of a lamp model on a screen using a touch panel display.

When the color temperature table setting mode / classic lamp setting mode is selected on the touch panel display screen, a color temperature selection screen in which the color temperature table and the classic lamp icon of FIG. 2 are combined is displayed. The classical lamp icon is indicated by a jutter sodium lamp (2,200K), tungsten lamp (3,000K), halogen lamp (4,000K), metal halide lamp (4,500K), xenon lamp (5,000K) and the like on the left side. Therefore, the lighting engineer is provided with a user interface for selecting the color temperature on the color temperature table displayed on the screen or by selecting the icon of the classic lamp to set the color temperature. The illumination engineer selects an icon corresponding to his or her classic lamp, such as a xenon lamp (HID), and the light source drives the LED light source at the color temperature of the xenon lamp.

3 shows another form of color temperature table. When the color temperature table of FIG. 3 is displayed on the screen of the touch panel display, selecting a desired color temperature sets the color temperature of the LED light source to the selected color temperature. Here, the color temperature refers to the temperature of light by complete thermal radiation. When heat is applied to the black body at the absolute temperature of 0 ° C (-273 ° C), the lowest temperature, radiation is generated. The unit is expressed in Kelvin. As the color temperature increases, the color changes from red to orange, yellow, white and blue. 3 shows a change in illumination according to the color temperature of the white LED. In other words, it can be seen that as the color temperature increases, the red light series changes from the blue light series.

On the touch panel display screen, <Table 1> is displayed on the touch panel screen when the color temperature lookup table setting mode / light display condition setting mode of each lamp model of the lamp manufacturer is selected. If the model number of each manufacturer is selected on the screen or the labeling condition is selected, the corresponding color temperature is set as the color temperature of the LED light source.

[Table 1] Color table and labeling conditions by lamp model of lamp manufacturer

The control unit 106 is composed of circuits such as a microcomputer or a microprocessor, a DRAM and a timer, executes the color temperature feedback control program of the present invention, and performs a control program such as general illumination control. Here, only the parts related to the lamp color temperature tracking feedback control will be described, and a detailed description of the general user adjustment control will be omitted.

The control unit 106 executes the color temperature feedback control control program according to the present invention. When the color temperature of the LED lamp 130 is set by the mode setting means 104, the pulse width control signal of FIG. 4 for driving the LED lamp 130 is generated at the set color temperature to control the switches 110 to 116. do. The color temperature of the current LED lamp 130 is detected by the color temperature detection signal of the LED lamp 130 detected by the color temperature detecting unit 102. The controller 106 compares the detected color temperature with the set color temperature, and controls the duty ratio of the pulse width control signal so that the color temperature of the LED lamp increases to the set value if the detected color temperature is lower than the set value. The duty ratio of the pulse width control signal is controlled to fall to the set value. Such a control value is created and stored in the lookup table and an address signal of the lookup table corresponding to the detected color temperature value is generated, and the data of the lookup table is read out by the generated address signal. The read data are white color temperature control data, green color temperature control data, red color temperature control data, and blue color temperature control data, and the duty ratio of the pulse width control signal is varied with the duty ratio corresponding to each data. By the drive combination of these white LEDs, green LEDs, red LEDs, and blue LEDs, color temperature control of the appropriate LED lamp is achieved.

The power supply unit 108 generates a DC power supply voltage by inputting 110V / 220V commercial exchange, and the generated DC power supply voltage is driven through the switches 110, 112, 114, and 116 to the white LED driving means 118 and the green LED driving means. 120, the red LED driving means 122, and the blue LED driving means 124. Therefore, each of the white LED driving means 118, the green LED driving means 120, the red LED driving means 122, and the blue LED driving means 124 is an LED driving current signal corresponding to the pulse width controlled power voltage signal, respectively. Each white LED, green LED, red LED, and blue LED constituting the LED lamp 130 is converted.

In the above embodiment, the LED lamp 130 shows an example in which green, red, and blue LEDs are arranged around a white LED, but is not limited thereto, and various multicolor LEDs may be combined.

5 and 6 show flowcharts for explaining a subject adaptive color temperature control program according to the present invention.

Referring to the drawing, the controller 106 checks the power input (S102), and when the power is turned on, displays the main menu on the touch pad type display of the mode setting means 104 (S104). When the lighting technician selects menu 1 in the main menu (S106), the color temperature table of FIG. 2 or 3 is displayed (S108). When the lighting technician selects the menu 2 in the main menu (S110), the above-described Table 1 is displayed on the touch pad display (S112).

Looking at the color temperature table or lookup table displayed in steps S108 and S112, when the illumination engineer selects a specific classic lamp, for example, a halogen lamp, a color temperature of 3,500 K corresponding to the halogen lamp is selected (S114), and the selected color temperature is the color temperature of the LED lamp 130. Is set to.

The controller 106 turns on and drives the LED lamp 130 at the set color temperature (S118). Therefore, since the LED lamp 130 is illuminated at the same color temperature as the halogen lamp, which is a classic lamp, the lighting engineer can work in the same lighting conditions as the illumination with a halogen lamp mastered to him.

The color temperature may be changed by various factors while driving the LED lamp under the set color temperature condition.

1. The light emission characteristics change due to the temperature rise of the PN junction of the light emitting diode.

2. The difference between the first color temperature and the color temperature after preheating during the preheating of the junction at initial lighting

3. Color Temperature Variation due to Characteristic Degradation with Time of Use of Light Emitting Diode

4. Color temperature change due to voltage and current instability

5. Lighting change of the lamp itself by the change of ambient brightness

6. Color temperature change by changing ambient humidity on rainy day

The color temperature detecting unit 102 of the present invention directly detects the color temperature change of the lamp due to such various color temperature change factors (S120).

The detected color temperature is compared with the set color temperature (S122), and it is determined whether the color temperature is increased or decreased. If the color temperature is higher than the set value, the control data is generated in the direction of lowering the color temperature, and if the color temperature is lower than the set value, the control data is generated in the direction of increasing the color temperature (S124). The control unit 106 generates the white, green, red, blue LED color temperature control signal using the generated control data as an address signal of the lookup table (S126). The generated color temperature control signal is applied to the switches 110 to 116 as a pulse width control signal to control the amount of current applied to the LED lamp 130.

Subsequently, the controller 106 checks whether a user's brightness control command exists (S128), and if the brightness change command exists, readjusts the pulse width to reflect the brightness value in the pulse width of the generated pulse width control color temperature control signal ( S130).

The color temperature control signal reflecting the color temperature and the brightness is applied as the switching control signal of the switches 110, 112, 114, and 116 to the white, green, red, and blue LED driving means 118, 120, 122, and 124. By controlling the applied power voltage to control the LED lamp variable color temperature (S132). If there is no power interruption (S134), the steps S106 to S118 are repeatedly performed to variably control the color temperature.

As described above, in the present invention, the color temperature detection means is installed in the lighting apparatus to directly detect the color temperature of the LED lamp, and the feedback control is performed so that the color temperature of the lamp follows the set color temperature. Therefore, the color temperature set by the user or the same color temperature as the classic lamp can be maintained at all times, which is suitable for special lighting such as a stage or a studio.

As described above, the present invention can replace the lamp in the field that requires special lighting, such as studio or stage lighting, from the existing filament heating or discharge lamp to the LED lamp, energy saving in the special lighting field, lamp maintenance There are industrial advantages, such as cost reduction.

Claims (8)

A light source consisting of at least one LED;
Color temperature detecting means for detecting a color temperature of the light source;
Mode setting means for setting a color temperature mode of the light source;
And a control unit for driving the light source in the color temperature mode set by the mode setting means and controlling the color temperature of the light source to be constantly maintained at the set color temperature in response to a color temperature detection signal through the color temperature detecting means. Color temperature feedback controlled LED lighting device. The LED lighting apparatus of claim 1, wherein the mode setting means sets the color temperature of at least one of tungsten incandescent lamps, fluorescent lamps, three-wavelength fluorescent lamps, halogen lamps, sodium lamps and xenon lamps. The color temperature feedback control type LED lighting apparatus according to claim 1, wherein the mode setting means sets a color temperature of at least one light marking condition among an incandite light, a warm light, a cool light, a day light, and a cool day light. The color temperature feedback control type LED lighting apparatus according to claim 1, wherein the mode setting means sets at least one color temperature of at least one lamp model among color temperature lookup tables of lamp models of a lamp manufacturer. The color temperature feedback control type LED lighting apparatus according to claim 1, wherein the mode setting means sets a color temperature of at least one color temperature lamp model of the color temperature table. The color temperature feedback control type LED lighting device of claim 1, wherein the control unit variably adjusts a pulse width ratio of a pulse width control signal generated by color temperature control data in response to the color temperature detection signal. The color temperature feedback controlled LED lighting device of claim 1, wherein the light source includes a white LED disposed at a center thereof, and red, green, and blue LEDs disposed at equal intervals on a main surface thereof. Setting a color temperature of the LED light source;
Driving the LED light source at the set color temperature;
Detecting a color temperature of the driven LED light source;
Comparing the detected color temperature with the set color temperature;
And controlling the driving of the LED light source to follow the set color temperature if the detected color temperature is different from the set color temperature as a result of the comparison.

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