JPH0521173A - Variable color lighting device - Google Patents

Abstract

PURPOSE:To light each light source in a stable condition when the light color of an illuminating light is made variable by the mixing color of light sources which have plural light colors. CONSTITUTION:The red system, the green system, and the blue system of light sources 2R1, 2R2, 2G1, 2G2, 3B1, and 2B2 are provided giving two sets for each color. One side light source 2B2 of the blue system is connected to a dimmer 4B through a switch element SWB. When the light quantity set to a light quantity data memory 6 is less than 40%, the switch element SWB is turned off, and at the same time, the dimming level of the light source 2B1 is corrected to the two times.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable color lighting device which is capable of obtaining a desired color-mixed light by mixing a plurality of types of light colors.

[0002]

2. Description of the Related Art Conventionally, it has been considered to control the living environment by adjusting the color temperature of illumination light.
For example, even with white lighting, if the color temperature is adjusted according to the temperature, a coolness or warmth can be obtained, and the living environment is improved. For such a purpose, a variable color lighting device having a configuration as shown in FIG. 11 is considered.
In this variable color lighting device, three color light sources 2 of red, green and blue are used.
R, 2G, 2B are provided in one fixture body to configure the lighting fixture 1, and the light sources 2R, 2G, 2B are configured to be dimmed by the control unit 3. The control unit 3 controls each of the light sources 2R and 2R.
Each of the light sources 2R and 2 is inserted between the G and 2B and the power source AC.
Dimmers 4R, 4G, 4 for controlling the dimming level of G, 2B
B, the light control levels of the respective light sources 2R, 2G, 2B are set by the light control signals input from the light control signal generator 5 to the light control devices 4R, 4G, 4B. Further, the dimming signal is output based on the light amount data in which the correspondence relationship between the color temperature of the illumination light obtained as a color mixture by the lighting fixture 1 and the dimming level of each of the light sources 2R, 2G, 2B is set. The light amount data is stored in the light amount data storage unit 6. The plurality of sets of light amount data stored in the light amount data storage unit 6 are
It is selected by operating the illumination light setting section 7, and the dimming level of each light source 2R, 2G, 2B is determined. The light amount data storage unit 6 is composed of a memory such as a RAM or a ROM, and stores the light amount data for each of the light sources 2R, 2G, and 2B as a set for each address. That is, the address corresponds to the color temperature, and by designating the address corresponding to the desired color temperature, the light amount data corresponding to the color temperature is output. Therefore, the illumination light setting unit 7 may be configured to be able to specify the address of the light amount data storage unit 6, and is configured by an up / down counter, a switch, and the like.

By the way, the light quantity data is set as follows. That is, the light colors of the respective light sources 2R, 2G and 2B are (x _R , y _R ), (x _G , y _G ), respectively in chromaticity coordinates.
(X _B , y _B ) and each light source 2R, 2G, 2B
Assuming that the light amount of each is Y _R , Y _G , and Y _B , respectively, the light color (x ₀ , y ₀ ) of the illumination light, which is a mixed color, and the light amount Y ₀ are
It becomes like number 1.

[0004]

[Equation 1]

If the light colors of the respective light sources 2R, 2G, 2B are not changed even if the light amount is changed, a mixed color is obtained by changing the light amount ratio of the light sources 2R, 2G, 2B. The light color of the illumination light can be changed, and the light amount of the illumination light can be changed by changing the light amount while maintaining the ratio of the light amounts of the respective light sources 2R, 2G, 2B. Therefore, the light amount data is created according to the light color of the illumination light, the variable range of the light amount, the specifications of the light source, and the like.

[0006]

Now, it is assumed that a plurality of light sources 2R, 2G and 2B whose chromaticity coordinates of light color are as follows are used. That is, reddish color (0.5859, 0.3
327), green (0.3324, 0.5349), and blue (0.1563, 0.0829). Further, the color temperature is variable within the range of 2950 to 6250 [K]. The maximum illuminance of each light source 2R, 2G, 2B on the reference irradiation surface is 110 [lx], 220 [lx], 3 respectively.
When 0 [lx] is set and the illuminance on the reference irradiation surface by the mixed illumination light is set to 200 [lx], the dimming level of each light source 2R, 2G, 2B for each color temperature of the illumination light is It becomes like Table 1.

[0007]

[Table 1]

As shown in Table 1, when the color temperature of the illumination light is high, the light control level of the blue light source 2B is higher than that of the red light source 2R, and conversely, when the color temperature is low, the red light source. The dimming level of 2R is higher than that of the blue light source 2B. Here, as the light sources 2R, 2G, and 2B, any light source such as a fluorescent lamp, a colored light bulb, a HID lamp, or a combination of a lamp and a color filter can be used as long as it can emit different colors. Can be used. By the way, which light source 2
Even when R, 2G, and 2B are used, if the dimming level becomes low, the lighting state becomes unstable and flicker occurs. In particular, in the case of a light bulb color, the light control level of the blue light source 2B becomes 11%, so that there arises a problem that stable illumination light cannot be obtained with such a low luminous flux. Therefore, the variable range of the color temperature at which stable illumination light can be obtained is limited.

Further, although the above description is based on the assumption that the light color of each of the light sources 2R, 2G, and 2B does not change even if the dimming level changes, in general, dimming is performed in a region where the dimming level is low. The color temperature changes depending on the level. For example, if a blue fluorescent lamp is used as the light source 2B, the chromaticity coordinate of the light color is (0.1563, 0.0829) when 100% is turned on.
On the other hand, the chromaticity coordinate of the light color changes to (0.1543, 0.0750) at 10% lighting. When the dimming level of each of the light sources 2R, 2G, and 2B is set to 72%, 54%, and 10%, respectively, the chromaticity coordinate of the light color of the illumination light is (0.441) unless changes in the light color are taken into consideration.
1, 0.4050), but considering the change in light color, it becomes (0.4388, 0.4019), and the difference in color temperature becomes about 100 [K]. If there is such a difference in color temperature, a difference in light color will be recognized. That is, by changing the dimming level while keeping the ratio of the light amounts of the respective light sources 2R, 2G, 2B constant, the light color changes even when it is desired to keep the light color constant and adjust only the light amount. There will be problems. In order to solve such a problem, the light quantity data is created in consideration of the change of the light color according to the dimming level, or the dimmers 4R, 4G, 4B are configured to compensate the change of the light color. However, it is difficult to create the light quantity data, and the dimmer 4R,
There is a problem that the configuration of 4G and 4B becomes complicated.

An object of the present invention is to solve the above-mentioned problems, and it is possible to widen the variable range of the color temperature and the light amount of the illumination light which is a mixed color, and at the same time, shift the color temperature with respect to the set light amount data. The present invention is intended to provide a variable color lighting device with less power consumption.

[0011]

In the present invention, in order to achieve the above object, a plurality of light sources of plural kinds of light colors are provided and a plurality of light sources are provided for at least one light color, and the light quantity of each light color is changed. In the variable color lighting device provided with the control unit that adjusts the illumination color obtained as a mixed color, the control unit controls the light source to be turned on when the light color having a plurality of light sources is set to a predetermined light amount or less. By reducing the number, the dimming level of the light source that is turned on is maintained above a predetermined level.

[0012]

According to the above construction, a plurality of light sources for the same light color are provided, and when the light quantity is set to be less than a predetermined light quantity, the number of light sources to be turned on is reduced to turn on the light sources. Since the dimming level of is kept above a predetermined level, it is possible to avoid lighting the light source in a low dimming level area where the lighting state becomes unstable or the light color changes. As a result, the color temperature of the illumination light and the variable range of the light amount can be widened, and the color temperature deviation with respect to the set light amount data can be reduced.

[0013]

【Example】

(Embodiment 1) In this embodiment, as shown in FIG. 1, light sources 2R ₁ , 2R ₂ , 2G ₁ , 2G ₂ , 2B composed of fluorescent lamps of three types of red, green and blue light colors. ₁ , 2B
_The luminaire 1 is configured by providing _{two 2} for each light color in one luminaire body. Each light source 2R ₁ , 2
R ₂ , 2G ₁ , 2G ₂ , 2B ₁ , 2B ₂ are dimmed by the control unit 3. The controller 3 controls the light sources 2R ₁ and 2
Dimmers 4R, 4G, and 4B for dimming R ₂ , 2G ₁ , 2G ₂ , 2B ₁ , and 2B ₂ are provided for each light color.
R, 4G, and 4B are light sources 2R ₁ , 2R ₂ , 2G ₁ , and 2G ₂ , respectively, according to the dimming signal output from the dimming signal generator 5.
Controls the dimming level of 2B ₁ and 2B ₂ . Further, the dimming signal generation unit 5 generates a dimming signal based on the light amount data stored in the light amount data storage unit 6 including a memory such as a ROM or a RAM. The light amount data includes the color temperature of the illumination light from the luminaire 1 and the light sources 2R ₁ , 2R ₂ , 2G ₁ , 2G ₂ ,
2B ₁ and 2B ₂ are made to correspond to each other, and the storage units 6R for each light color, which constitute the light amount data storage unit 6,
It is stored in 6G and 6B. When selecting the light amount data stored in the light amount data storage unit 6, the address data generated by the address designating unit 8 based on the setting state of the illumination light setting unit 7 causes the specific address of the light amount data storage unit 6 to be changed. It is specified. Here, the storage unit 6R corresponding to each light color,
6G and 6B have the same address, and three sets having the same address form one light quantity data. The illumination light setting unit 7 is composed of a switch group for setting the light color and amount of the illumination light and a display for displaying the setting state, and the address designating unit 8 has a microprocessor as a main component. is there. The above-mentioned configuration is basically the same as the conventional configuration shown in FIG.

By the way, the switch element SW _B contacts like the relay is inserted between the light source 2B ₂ dimmer 4B in the present embodiment, on the switching element SW _B, light source 2B ₂ in response to off Blinks. The switch element SW _B is turned on and off by the switch switching unit 9 that operates based on the dimming signal output from the dimming signal generating unit 5, and the two light sources 2B ₁ and 2B _{2 are included.}
In the state in which the lights are simultaneously turned on, _one of the light sources 2B ₁ and 2B ₂ of the same light color is turned off when a dimming signal by which the dimming level by the dimmer 4B becomes a predetermined level or less is generated. That is, when the dimming level becomes equal to or lower than a predetermined level when the two light sources 2B ₁ and 2B ₂ are simultaneously turned on, the light source 2B is turned on without reducing the light amount.
By reducing the number of _1, it lit light source 2
The dimming level of B ₁ is maintained at a predetermined level or higher to prevent the lighting state of the light source 2B _{1 from} becoming unstable and the light color from changing in a region where the dimming level is low.

Now, the dimming signal is a pulse signal, as shown in FIG.
As shown in FIG. 4, the dimmers 4R, 4G, and 4B have the light sources 2R ₁ , 2R ₂ , 2G ₁ , 2G ₂ , and 2B so that the light amount (that is, the dimming level) is reduced when the on-duty increases.
The dimming level of ₁ and 2B ₂ shall be controlled. Also,
It is assumed that the light sources 2B ₁ and 2B ₂ are stably turned on when the dimming level is 41 to 100%, and the lighting state is unstable or the light color is changed when the dimming level is 40% or less.

When a desired light color and light amount are input from the illumination light setting unit 7 to obtain a desired illumination light, the address designating unit 8 stores light amount data corresponding to the set light color of the illumination light. The address data corresponding to the existing address is generated. When the light quantity data storage unit 6 is set to the read state and a specific address of the light quantity data storage unit 6 is designated by the address data, the light quantity data for determining the dimming level of each of the dimmers 4R, 4G, 4B is output, Dimming signal generator 5
Then, the light amount data is converted into a dimming signal which is a pulse signal. The dimming signal is input to the dimmers 4R, 4G, and 4B for each light color, but the dimming signal to the blue dimmer 4B is input to the dimmer 4B through the switch switching unit 9. .. The switch switching unit 9 determines the on-duty of the input dimming signal to turn on / off the switch element SW _{B. The} dimming signal of the on-duty whose dimming level is 41 to 100% is input. when it is keeps turning on the switching element SW _B, dimming signal on duty of 40% or less to turn off the input switching element SW _B. In addition, the light quantity data is obtained from the two light sources 4B ₁ and 4B ₂
Therefore, the switch switching unit 9 turns on the dimming signal input to the dimmer 4B so that the light amount set in the light amount data is maintained with one light source 4B ₂ turned off. Correct the duty to correct the dimming level. In short, since the light source 2B ₂ is turned off when the switch element SW _B is turned off, the light source 2 for the blue light color is
If only B ₁ is turned on, and if the light intensity data for blue is 35% of the maximum light intensity, the dimming signal to the dimmer 4B is adjusted so that the dimming level of the light source 2B ₁ becomes about 70%. The on-duty of is corrected.

A specific example of the switch switching section 9 that performs the above operation will be described with reference to FIGS. 3 and 4. The dimming signal, which is a pulse signal, includes an operational amplifier OP ₁ , resistors R ₁ , R ₂ , and R.
₃ , the capacitor C ₁ , the analog switch S ₁ , the NOT circuit NOT ₁ , and the Zener diode ZD ₁ are input to the integrating circuit 11. The integrator circuit 11 outputs a voltage corresponding to the time width of the input signal equal to or higher than the predetermined voltage set by the Zener diode ZD ₁ . That is, as shown in FIG. 4A, the period when the dimming signal is at the H level (ON period)
Since the analog switch S ₁ is off as shown in FIG. 4B, the capacitor C ₁ is charged through the resistor R ₁ and is proportional to the terminal voltage of the capacitor C ₁ as shown in FIG. 4C. The voltage is output from the integrating circuit 11. Also,
During the period when the dimming signal is at L level (off period), the analog switch S ₁ is turned on, and the electric charge of the capacitor C ₁ is discharged through the resistor R ₂ .

The output voltage of the integrating circuit 11 is a sample-hold circuit 12 including an analog switch S ₂ , a capacitor C ₂ , and an operational amplifier OP ₂ which constitutes a voltage follower.
The output voltage of the integrating circuit 11 at the end of the ON period of the dimming signal is held as the terminal voltage of the capacitor C ₂ . Since the analog switch S ₂ is controlled by the dimming signal, as shown in FIG.
During the ON period of the dimming signal, the analog switch S ₂ is turned on, the terminal voltage of the capacitor C ₂ increases according to the output voltage of the integrating circuit 11, and during the OFF period of the dimming signal, the analog switch S ₂ is turned off. Then, the terminal voltage of the capacitor C ₂ is maintained at the voltage immediately before the analog switch S ₂ is turned off. Therefore, if the on-duty of the dimming signal is constant, the output voltage of the sample hold circuit 12 is a constant voltage as shown by the alternate long and short dash line in FIG. That is, the output voltage of the sample hold circuit 12 is proportional to the on-duty of the dimming signal.

The output voltage of the integrator circuit 11 and the output voltage of the sample hold circuit 12 are respectively the comparator CP.
₁ and CP ₂ are compared with the reference voltage Vr (two-dot chain line in FIG. 4C). The reference voltage Vr is set by using a series circuit of a resistor R ₄ and a Zener diode ZD ₂ inserted between both ends of the power supply and resistors R ₅ and R ₆ that divide the voltage between both ends of the Zener diode ZD _2. It Since the output voltage of the sample hold circuit 12 is proportional to the on-duty of the dimming signal, it is possible to judge whether the dimming level is equal to or higher than a predetermined level, based on the magnitude relationship with the reference voltage Vr. The output of the comparator CP ₁ becomes H level while the output voltage of the integrating circuit 11 is lower than the reference voltage Vr. The output of the comparator CP ₁ becomes a signal which goes to the H level while the output voltage of the integrating circuit 11 is higher than the reference voltage Vr as shown in FIG. 4E through the NOT circuit NOT ₂ . In addition, the output of the comparator CP ₂ is the output voltage of the sample hold circuit 12 is the reference voltage Vr.
It becomes H level in a lower period. Comparator CP ₂
The output of ON controls ON / OFF of the analog switch S ₃ , and also controls ON / OFF of the analog switch S ₄ through the NOT circuit NOT ₃ . That is, the output of the comparator CP ₂ is used to selectively output _one of the output of the NOT circuit NOT ₂ and the dimming signal from the terminal T ₁ through the OR circuit OR, and this output is input to the dimmer 4B. Is done. Pull-down resistors R ₇ and R ₈ are connected to the respective input terminals of the OR circuit OR, and are maintained at the L level when there is no input. In addition, the comparator C
The output of P ₂ is taken out from the terminal T ₂ and the switch element S
It is also used as a switching signal for W ₁ .

According to the above configuration, the comparator CP ₂
Output becomes H level in a region where the on-duty of the dimming signal is small, so when the dimming level is high, the dimming signal input to the switch switching unit 9 is directly output from the OR circuit OR, and the dimming level is When N is low, Negative circuit N
The output of OT ₂ is output. As a result, when the dimming level is high, a dimming signal with a small on-duty is output, and when the dimming level is below the set level and the on-duty of the input dimming signal is above the set value,
At the same time as the switching signal output from the terminal T ₂ to the switch element SW _B becomes L level and the switch element SW _B is turned off, a corrected dimming signal whose on-duty is smaller than the input dimming signal is generated. It is output from the terminal T ₁ to the dimmer 4B. Here, when the dimming level by the dimmer 4B is in the range of 41 to 100%, the light sources 2B ₁ , 2
Since a stable light output can be obtained from B ₂ , the reference voltage Vr
Is set such that the output of the comparator CP ₂ becomes L level when a dimming signal having an on-duty such that the dimming level becomes 40% or less is input to the switch switching unit 9. Moreover, the on-duty of the corrected dimming signal, the resistor R _1, a of being determined by the R ₂ and the capacitor C _1, resistors R _1, R ₂ and capacitor C ₁
The values of and are such that when the dimming level reaches 40% and the light source 2B ₂ is turned off, the dimming level of the lit light source 2B ₁ is set to 80% so that the light amount of the blue light color does not decrease. Is set to pull up. When a dimming signal with a dimming level of 40% or less is input and the dimming level is 20
%, The dimming level after correction is 40%
%, 60%.

As described above, the blue light source 2
For B ₁ and 2B ₂ , the two light sources 2B ₁ and 2B ₂ are turned on in a large amount of light area where the lighting state is stable, and only one light source 2B ₁ is used in a small amount of light area where the lighting state becomes unstable. Is turned on, and the dimming level of the light source 2B ₁ which is turned on so as to maintain a predetermined light amount at this time is made higher than the dimming level set by the dimming signal. Therefore, the light source 2B ₁ can be dimmed in a region where the lighting state is stable. In addition, the light sources 2B ₁ and 2B ₂ are set to 2
Since the state of individual lighting and the state of single lighting are switched, the correction amount of the dimming level in the switch switching unit 9 is set so that the change of the light amount is continuous at this time. Here, the switching point between the state where _two light sources 2B ₁ and 2B ₂ are turned on and the state where one light source is turned on is the dimming level 4
Although it is set at the boundary between 1% and 40% (in steps of 1%), it goes without saying that the dimming level at the switching point is appropriately set depending on the specifications of the light sources 2B ₁ and 2B _2. ..

The illumination light setting section 7 may be configured to increase / decrease the address data indicating the address of the light quantity data storage section 6 by using two switches and an up / down counter. Further, the number of light sources and the types of light colors are not limited as long as the light sources of a plurality of light colors are provided and a plurality of light sources are used for at least one light color. That is, the number of light sources for light colors other than blue may be switched,
Also, the number of lights for all light color light sources may be switched. Further, the number of light sources to which the dimmer is connected via the switch element is not limited to one. Any kind of light source may be used as long as different light colors can be obtained as shown in the conventional example. For the dimming signal, the on-duty of the pulse signal is changed to indicate the dimming level. Other than the above, a device that indicates a dimming level by a voltage level or the like can be used, and the present invention is not limited to the embodiment.

(Embodiment 2) In the embodiment 1, the switch switching section 9 controls ON / OFF of the switch element according to the dimming level of the input dimming signal, and the dimming level of the dimming signal is changed. Although the light amount data stored in the light amount data storage unit 6 is corrected in advance in this embodiment, the light amount data is stored in the corrected state. Assuming that the light source has the same configuration as that of the first embodiment, it is 2 when the dimming level is 41 to 100% for the blue light color.
Since the individual light sources 2B ₁ and 2B ₂ are turned on at the same time, for example, when the dimming level is 100% and 41%, as shown in FIGS. 5A and 5B, both light sources 2B ₁ and 2B ₂ are turned on. 100% lighting, 41% lighting. On the other hand, since only one light source 2B ₁ is turned on when the dimming level is 40% or less, for example, when the dimming level is 40% and 20%, as shown in FIGS. 5C and 5D, respectively. The one light source 2B _{1 that} is turned on is turned on by 80% and turned on by 40%.
If the light quantity data corrected in consideration of such a lighting state is stored in the light quantity data storage unit 6, the dimming level becomes 41.
The on-duty change of the dimming signal is continuous in the range of up to 100% and in the range of 40% or less, but when the dimming level exceeds the boundary between 40% and 41%, the dimming signal is increased. The on-duty of will change discontinuously. Therefore, when operating the illumination light setting unit 7, turning on the switch element SW _B, as the amount of light colors that need to be turned off is continuously changed, configuration and quantity data storage of the illumination light setting unit 7 The data array of the section 6 is set in advance. That is, the illumination light setting unit 7 is configured so that the address data for instructing the address of the light amount data storage unit 6 sequentially increases and decreases by using, for example, two switches and an up / down counter. On the other hand, the light amount data storage unit 6 stores the light amount data so that the light amounts of the blue light sources 2B ₁ and 2B ₂ continuously change in the order of addresses. In such a configuration,
When the illumination light setting unit 7 is operated, the light amount for the light sources 2B ₁ and 2B ₂ continuously changes, so that the light amount is 40% and 41%.
The switching point can be detected by detecting a discontinuous change in the on-duty of the dimming signal when the boundary between and is crossed.

Therefore, the switch switching section 9 is configured to detect the discontinuity of the on-duty of the dimming signal, and as shown in FIG. 6, the dimming signal is the same as in the first embodiment. It is input to the integrating circuit 11, and the integrating circuit 11 outputs an output voltage proportional to the on-duty. Further, the dimming signal is also input to the timing control circuit 13 including, for example, a timer circuit, and the trailing edge of the dimming signal is detected as shown in FIG.
As shown in (f), (h), (i), and (j), the six output terminals O
_A timing pulse that becomes H level in order from ₁ , O ₂ , O ₃ , O ₄ , O ₅ , O ₆ is output. The output voltage of the integrating circuit 11 changes according to the on-duty of the dimming signal as shown in FIG. 7C, and the slope of the output voltage waveform is determined by the resistor R ₁ and the capacitor C _1. .. From the output terminal O ₁ of the timing control circuit 13 shown in FIG.
Of the gate signal is output, and the sample hold circuit 12 is operated during the period when the gate signal is at the H level.
The analog switch S ₂ is turned on and the output voltage of the integrating circuit 11 is held in the capacitor C ₂ . After that, the reset signal as shown in FIG. 7D is output from the output terminal O ₂ of the timing control circuit 13, the analog switch S ₁ of the integrating circuit 11 is turned on, and the capacitor C ₁ is discharged. The integration circuit 11 integrates the dimming signal until the reset signal is generated.

The output voltage of the sample-and-hold circuit 12 (see FIG. 7 (e)), a pair of subtraction circuits through an analog switch S ₈ (differential amplifier) 15a, is input to the 15b, the analog switch S ₆ It is input to another sample-hold circuit 14 having an operational amplifier OP ₃ which serves as a voltage follower via. After the output voltage of the integration circuit 11 is held in the sample hold circuit 12, the analog switch S ₈ outputs the output terminal O ₃ of the timing control circuit 13.
It is turned on by the pulse signal as shown in FIG. Further, the sample hold circuit 14 outputs the signal from the output terminal O ₄ of the timing control circuit 13 shown in FIG.
Immediately after receiving the reset signal as shown in (h), the analog switch S ₇ connected with the resistor R ₁₀ across the capacitor C ₃ is turned on immediately after the analog switch S ₈ is turned on. After that, the output terminal O of the timing control circuit 13
_The analog switch S ₆ is turned on by the gate signal output from ₅ as shown in FIG. 7 (i) to hold the output voltage of the sample hold circuit 12. In this way, when the output voltage of the sample hold circuit 12 is held in the sample hold circuit 14, the reset signal as shown in FIG. 7 (j) output from the output terminal O ₆ of the timing control circuit 13 is received, Capacitor C of the sample and hold circuit 12
_The analog switch S ₅ connected with the resistor R ₉ across both ends of ₂ is turned on. In short, the sample-hold circuit 12 holds the peak value V ₂ of the output voltage of the integration circuit 11 corresponding to the length of one ON period of the dimming signal, and the sample-hold circuit 14 holds the peak value V ₂ of the dimming signal once. The peak value V of the output voltage of the integrating circuit 11 corresponding to the length of the previous ON period
₁ is to hold.

Output voltage of the sample and hold circuit 14 (see FIG.
7 (g)) is the analog switch S₉Pair through
Is input to the subtraction circuits 15a and 15b. Analog switch
Touch S₉Is the analog switch S₈At the same time, Taimin
Output terminal O of control circuit 13 ₃Pulse signal output from
It is turned on and off depending on the issue. That is, each subtraction circuit 1
5a and 15b, the length of one ON period of the dimming signal and
Compare the voltage corresponding to the length of the ON period one time before,
As shown in 7 (k), output the voltage corresponding to the difference.
It is. Here, FIG. 7 (k) shows the output of the subtraction circuit 15a.
The output polarity is different from that of the subtraction circuit 15b.
So that it is reversed (ie the sign of the output value is reversed)
The connection relation is set.

The output of each subtractor circuit 15a, 15b is compared is input to the comparator CP _3, CP _4, a reference voltage Vs output from the reference voltage generator 16. When the output voltage of either one of the subtraction circuits 15a and 15b is higher than the reference voltage Vs, the outputs of the corresponding comparators CP ₃ and CP ₄ are at the H level as shown in FIG. ) shows the output of the comparator CP _3). The outputs of the comparators CP ₃ and CP ₄ are input to the up terminal and the down terminal of the up / down counter 17, respectively. The up / down counter 17 uses an output of 1 bit (the least significant bit of a plurality of bits), and the rising edge of the input to the up terminal UP (or
The output becomes L level at the fall) and the NOT circuit NOT
The output of ₄ is set to H level. Further, the up / down counter 17 is set so that its output becomes H level at the rising (or falling) of the input to the down terminal DOWN and the output of the NOT circuit NOT ₄ becomes L level.

According to the above configuration, when the on-duty of the dimming signal changes from a large on-duty to a sharp decrease (that is, when the dimming level changes from 41% to 40%), subtraction is performed. Since the output voltage of the circuit 15a becomes a positive voltage larger than the reference voltage Vs, the output of the comparator CP ₁ becomes L level during the period when the analog switches S ₈ and S ₉ are on (at this time, the output voltage of the subtraction circuit 15b). Has a negative polarity, the output of the comparator CP ₂ does not change), and the input to the up terminal of the up / down counter 17 changes. As a result, the output of the switch switching unit 9 output from the NOT circuit NOT ₄ becomes L level,
The switch element SW _B is turned off and the light source 2B ₂ is turned off. On the other hand, when the on-duty of the dimming signal suddenly changes from a small state to a large state (that is, when the dimming level changes from 40% to 41%), the output voltage of the subtraction circuit 15b is the reference voltage Vs. Since the positive voltage becomes larger than that, the output of the comparator CP ₂ becomes L level while the analog switches S ₈ and S ₉ are on, and the input to the down terminal of the up / down counter 17 changes. That is, the output of the switch switching unit 9 becomes H level and the switch SW _B is turned on.

[0029] As described above, on the dimming signal on switch elements SW _B detects a rapid change of the duty, there is to determine the off switching of the switching element SW _B by a change of the dimming level Only the signal is generated. That is, the on-duty of the dimming signal is determined by the light amount data, and the dimming signal to the dimmer 4B is not corrected according to the on-duty of the dimming signal as in the first embodiment. An error due to the circuit constant does not occur in the on-duty of the dimming signal to the optical device 4B. Instead of the up / down counter 17, RS
It is also possible to use flip-flops. The other configurations and operations are the same as those in the first embodiment, and the description thereof will be omitted.

(Embodiment 3) In each of the above embodiments, a dimmer is provided for each light color, but in this embodiment, as shown in FIG. 8, a light source having a blue light color is used. 2B ₁ , 2
Regarding B ₂ , light sources 4B ₁ and 4B ₂ are provided for the respective light sources 2B ₁ and 2B ₂ . Therefore, the light amount data for each of the dimmers 4B ₁ and 4B ₂ is set individually and stored in the storage units 6B ₁ and
It is stored in 6B ₂ . The light quantity data in the storage unit 6B ₁ is the same as that in the second embodiment, and the light quantity data in the storage unit 6B ₂ is the ratio of the light quantity to the maximum light quantity (hereinafter, abbreviated as light quantity ratio).
Is set to 40% or less, the dimming level of the dimmer 4B ₂ is set to 0%. The dimmer 4B ₂ is configured to turn off the light source 2B ₂ when the dimming level is 0%. For example, if the light quantity ratio is 45%,
The light quantity data of the storage units 6B ₁ and 6B ₂ are both 45%, but if the light quantity ratio is 20%, the light quantity data of the storage unit 6B ₁ is set to 40% and the light quantity data of the storage unit 6B ₂ is set to 0%. To be done. With this configuration, the switch element SW _B as in the above embodiment is not required, and therefore the circuit configuration is simplified. Other configurations and operations are similar to those of the first embodiment.

(Embodiment 4) This embodiment is as shown in FIG.
And has a reddish light color.
A light source 2R and a light source 2G having a green color
Two light sources 2B having a blue light color₁, 2B
₂Is different from Example 3 in that the maximum light amounts of
It That is, when 100% is turned on, the light source 2B₂The amount of light
Light source 2B₁The light intensity is set to about 50%.
It Each light source 2B₁, 2B₂The dimming level of is shown in Fig. 10.
Controlled. The horizontal axis of FIG. 10 indicates the blue light color.
Ratio of light intensity to maximum light intensity (hereinafter abbreviated as light intensity ratio)
And the right vertical axis is the light source 2B. ₁Dimming level, left vertical
Axis is light source 2B₂Indicates the dimming level of (light source 2B₁Is real
Line, light source 2B₂Is the alternate long and short dash line). In this example, blue
When the light quantity ratio of the light colors of the color system is 41 to 100%, the light source 2
B₁Only the light is turned on, and light is emitted when the light intensity ratio is 40% or less.
Source 2B₂Only the lights are turned on. Because
If the light intensity ratio is in the range of 41 to 100%, the dimmer
4B₁Set the dimming signal to the dimming level to 41-100%.
Is determined by the dimmer 4B₂Dimmer 4B₁Same as
If the same configuration is used, the light intensity ratio will be less than 40%.
The dimmer 4B₂Is suitable for the dimming level of blue light
And a dimming signal with a doubled dimming level is input.
Is. For example, the light intensity ratio of blue light is 40%, 2
If 0%, dimmer 4B₂Dimming level of dimming signal to
Are 80% and 40%, respectively. Light intensity data storage unit 6
The light intensity data stored in is set based on the above concept.
The light quantity ratio for blue light is 4
In the range of 1-100%, dimmer 4B₁Set by
The dimming level is 41 to 100%, and the dimmer 4B₂To
The dimming level set more is 0%. Also, the light intensity ratio
In the range of 40% or less, dimmer 4B₁Key set by
Light level is 0%, dimmer 4B₂Set by
The dimming level is twice the dimming level to be set (80% or more
Below).

According to the above configuration, it is possible to set the minimum light amount smaller than that when a plurality of light sources having the same maximum light amount are used. Although both light sources 2B ₁ and 2B ₂ are selectively turned on in this embodiment, both light sources 2B ₁ and 2B ₂ may be turned on at the same time when the light amount is increased. Further, although the light amount data for each of the light sources 2B ₁ and 2B ₂ is stored in the separate storage units 6B ₁ and 6B ₂ , the light amount data is stored in one storage unit and a dimming signal is input according to the light amount data. The optical devices 4B ₁ and 4B ₂ may be selected. The other configurations and operations are the same as those in the first embodiment, and the description thereof will be omitted.

In each of the above embodiments, the case where the light color of the illumination light is variable has been described, but the technical idea of the present invention is applied even if only the light adjustment is performed without changing the light color. By applying it, it is possible to change the number of lights of the plurality of light sources according to the dimming level, and to widen the adjustment range of the light amount in a stable lighting state.

[0034]

As described above, according to the present invention, a plurality of light sources for the same light color are provided, and when the light amount is set to a predetermined light amount or less, the number of light sources to be turned on is reduced to turn on the light. Since the dimming level of the light source being used is kept above a predetermined level, it is recommended to turn on the light source in the low dimming level area where the lighting state becomes unstable or the light color changes. It can be avoided, and as a result, there is an advantage that the color temperature of the illumination light and the variable range of the light amount can be widened. Further, since it is possible to avoid the change of the light color of the light source, it is possible to reduce the deviation of the color temperature with respect to the set light amount data.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment.

FIG. 2 is an operation explanatory diagram of the first embodiment.

FIG. 3 is a circuit diagram of a switch switching unit used in the first embodiment.

FIG. 4 is an operation explanatory diagram of a switch switching unit used in the first embodiment.

FIG. 5 is an explanatory diagram showing an example of a dimming signal according to a second embodiment.

FIG. 6 is a circuit diagram of a switch switching unit used in the second embodiment.

FIG. 7 is an operation explanatory diagram of a switch switching unit used in the second embodiment.

FIG. 8 is a block diagram of a third embodiment.

FIG. 9 is a block diagram of a fourth embodiment.

FIG. 10 is an operation explanatory diagram of the fourth embodiment.

FIG. 11 is a block diagram showing a conventional example.

[Explanation of symbols]

1 Lighting fixture 2R ₁ Red light source 2R ₂ Red light source 2G ₁ Green light source 2G ₂ Green light source 2B ₁ Blue light source 2B ₂ Blue light source 3 Controller 4R Red light dimmer 4G Green-based dimmer 4B Blue-based dimmer 5 Dimming signal generator 6 Light intensity data storage 7 Operation part 8 Address indication part

Claims (1)

Claim: What is claimed is: 1. A light source for a plurality of types of light colors is provided, and a plurality of light sources for at least one light color are provided, and an illumination color obtained as a mixed color is obtained by changing the light amount of each light color. In the variable color lighting device provided with a control unit for adjusting, the control unit lights by reducing the number of light sources to be turned on when setting the light color having a plurality of light sources to a predetermined light amount or less. A variable color lighting device characterized in that the dimming level of a light source is maintained at a predetermined level or higher.