Variable color luminaire - Patent Review 5418432

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BACKGROUND OF THE INVENTION

This invention relates to a variable color luminaire of which luminaire light color is made variable with a plurality of emission colors properly blended.

DESCRIPTION OF RELATED ART

It has been generally attempted to vary human life environment by modulating color temperature of luminaire light. Even in the event of luminaire light in white colors, for example, it is enabled to provide either a cool or warm atmosphere by modulating the color temperature in accordance with ambient temperature, so that the life environment may be improved.

For luminaires realizing the variable color, there has been adopted an arrangement in which three color light sources of red, green and blue are disposed in each device unit and are subjected to a dimming executed by a control section which comprises dimmers respectively inserted between each light source and a power source for controlling dimming level of each light source, and the dimming level of the respective light sources is set by a dimming signal provided from dimming signal generators to the respective dimmers. The arrangement is so made that the dimming signals are provided as based on data of the quantity of light (which shall be referred to as the "quantity-of-light data" hereinafter) into which corresponding relationship between the color temperatures of the luminaire light obtained in a blended color to the dimming level of the respective light sources is set, upon which the quantity-of-light data are stored in a quantity-of-light data memory, and a plurality of pairs of the quantity-of-light data thus stored can be subjected to a selection by an operation of a luminaire light setting means, and the dimming levels of the respective light sources are to be determined. This quantity-of-light data memory comprises normally such memories as RAM, ROM or the like, and three of the quantity-of-light data with respect to every light source are stored in a set for every address. That is, the address is made to correspond to the color temperature, so that the quantity-of-light data corresponding to any desired color temperature can be provided as an output. Accordingly, the luminaire light setting means may be provided for being capable of appointing the address of the quantity-of-light data memory and may comprise an up-down counter and a switch or the like.

Referring more specifically to the foregoing known arrangement, the quantity-of-light data are set as in the followings in practice. That is, assuming that the emission colors of the respective light sources are (x.sub.R, y.sub.R), (x.sub.G, y.sub.G) and (x.sub.B, y.sub.B) on the chromaticity coordinate and the quantity-of-light of the respective light sources is Y.sub.R, Y.sub.G and Y.sub.B, the emission colors and the quantity-of-light of the luminaire light which are blended will have following relational formulas:

x.sub.0 =(x.sub.R Yhd R/y.sub.R +x.sub.G Y.sub.G /y.sub.G +x.sub.B Y.sub.B /y.sub.B)/(Y.sub.R /y.sub.R +Y.sub.G /y.sub.G +Y.sub.B /y.sub.B)

y.sub.0 =(Y.sub.R +Y.sub.G +Y.sub.B)/(Y.sub.R /y.sub.R +Y.sub.G /Y.sub.G +Y.sub.B /Y.sub.B/ y.sub.B)

Y.sub.0 =(Y.sub.R +Y.sub.G +Y.sub.B)

Here, a variation in the ratio of the quantity-of-light of the respective light sources will allow the emission color of the luminaire light obtained in the blended color to be varied, and a variation of the quantity-of-light in a state where the quantity-of-light ratio of the respective light- sources is maintained will allow the quantity-of-light of the luminaire light to be varied. At this time, the quantity-of-light data can be properly prepared in accordance with the emission color of the luminaire light, variable range of the quantity-of-light, specification of the light source and so on.

Here, it is assumed that a plurality of light sources of which the chromaticity coordinates of the emission colors will be (0.5859. 0.3327) for red colors R, (0.3324, 0.5349) for green colors G, and (0.1563, 0.0829) for blue colors B are employed, and that the color temperature is to vary in a range of 2,950 [K] to 6,250 [K]. In this case, the respective light sources have the maximum illuminance on the reference irradiation surface of 110 [1x], 220 [1x] and 30 [1x], and, in an event when the illuminance on the reference irradiation surface by the luminaire light of the blended color is set to be 200 [1x], the dimming level of the respective light sources with respect to the respective color temperatures of the luminaire light will be as in a following Table I:

TABLE I ______________________________________ Dimmng. Lvl.of Lt. Col.Temp. Chrmtcty. Crdnt. Sorc.[%] [K] x y R G B ______________________________________ Daylight Color 6,250 0.314 0.345 29 69 55 White Color 4,200 0.378 0.388 48 70 27 Warm White Col. 3,450 0.409 0.394 67 58 19 Elec. Lamp Col. 2,950 0.440 0.403 72 54 11 ______________________________________

According to the foregoing known art, however, there arises deviation with respect to the set quantity-of-light due to fluctuation in the light output from the light sources, their variation in characteristics with time and shift in ambient conditions, fluctuation in output characteristics of the dimmer and so on, and eventually the set luminaire light color may also deviate, so as to cause a problem to occur in that the user may feel unpleasant.

In order to eliminate the above problem, there has been adopted such measure that a blended color light is set by a luminaire light setting means and the quantity-of-light data of the light source corresponding to the set value of the blended color light can be read out of the quantity-of-light data memory means. Assuming here that the values of -the quantity-of-light data for the respective light sources are V.sub.sr, V.sub.sg and V.sub.sb, a pair of the data V.sub.sr on the red R and V.sub.sg on the green G and another pair of the data V.sub.sb on the blue B and V.sub.sg on the green G are provided respectively into each of a pair of dividing means, and then outputs of these dividing means will be V.sub.sr /V.sub.sg and V.sub.sb /V.sub.sg. On the other hand, the quantity-of-light of the respective light sources is detected respectively by a quantity-of-light detecting means, their detection signals are converted by signal converting means to signals V.sub.yr, V.sub.yg and V.sub.vb suitable for a comparison operation, then the detected quantity-of-light values V.sub.yr and V.sub.yg for the red color and green color light sources are input into one of the dividing means, while the also detected quantity-of-light values V.sub.yb and V.sub.yg of the blue color and green color light sources are input into the other dividing means, whereby respective outputs V.sub.yr /V.sub.yg and V.sub.yb /V.sub.yg of these dividing means are input respectively into each of a pair of comparison operation means. Preferably, these comparison operation means comprise respectively a differential comparison circuit, and output signals V.sub.01 and V.sub.02 of these comparison operation means will be as following equations:

V.sub.01 =a.times.(V.sub.yr /V.sub.yg -V.sub.sr /V.sub.sg)

V.sub.02 =a.times.(V.sub.yb /V.sub.yg -V.sub.sb /V.sub.sg)

wherein a.gtoreq.1. These output signals V.sub.01 and V.sub.02 are input into a quantity-of-light data correction means to be thereby corrected to the quantity-of-light data V.sub.sr and V.sub.sb, and such output signals as follows are provided:

V.sub.sr '=V.sub.sr -a.times.(V.sub.yr /V.sub.yg -V.sub.sr V.sub.sg)

V.sub.sb '=V.sub.sb -a.times.(V.sub.yb /V.sub.yg -V.sub.sb V.sub.sg)

Here, the quantity-of-light data subjected to the correction are provided to dimming signal generating means to be subjected to a regulation of quantity-of-light, the quantity-of-light data are reproduced at a high fidelity, and the light of the blended color light conforming to the set value can be obtained. Further, in an event where the quantity-of-light in conformity to the quantity-of-light data cannot be obtained due to any reduction in the quantity-of-light caused by the variation with time or the like, the correction of the quantity-of-light ratio carried out with the quantity-of-light of the green color G made as the center prevents any deviation from occurring in the emission color of the blended color light. When, for example, the setting is made to the color temperature 2,950[K] of electric lamp color, the quantity-of-light data shown by the dimming ratio of the light sources of the red colors, green colors and blue colors will be 72%, 54% and 11% as will be clear from TABLE I, upon which the respective quantity-of-light of red, green and blue colors on the reference radiation surface will by 79.2 [1x], 118.8 [1x] and 3.3 [1x]. Provided here that the light source of the green emission color only, for example, attaining just 80% of the quantity-of-light with respect to the set quantity-of-light by means of the quantity-of-light data due to the reduction in the quantity-of-light, the quantity of green color light will become 118.8.times.0.8=95.04 [1x] and, if this quantity is used as it is, there should arise a deviation in the blended emission color from the set value. Provided here that the quantity-of-light of the red and blue colors as corrected through the foregoing correcting operation of the quantity-of-light ratio is made to be E.sub.R and E.sub.B, then E.sub.R =79.2.times.95.04./118.8=63.36 [1x] and E.sub.B =3.3.times.95.04/118.8=2.64 [1x], and the quantity-of-light data in the red and blue colors may be deemed to have been corrected respectively to 57.6% and 8.8%.

According to the foregoing known measure, however, it has been extremely difficult to have the quantity-of-light data corrected to values less than 10% in an event where the lower dimming limit of the dimming means is 10%, for example, there occurs inevitably a color deviation in the blended color light. In order that, in this event the correction will not be made to a value below the lower dimming limit of the dimmer, taking into account the reduction in the quantity-of-light due to any affection of the variation with time or the like in the luminaire in which the ratio of the respective quantity-of-light of the red, green and blue colors, it is necessary that the dimming range to be used as the respective quantity-of-light data of the red, green and blue color light is made to be about 20 to 100% irrespective of ordinary dimming range of 10 to 100% as inherent property of general dimmers, and the quantity-of-light data which does not employ the entire range of the inherent dimming range are set.

When, as has been described above, the dimming range to be used as the quantity-of-light data, in particular, part of the range adjacent to the lower limit of the dimming is set to have a margin so as to carry out the dimming in the range of 20 to 100%, it becomes impossible to obtain the emission color of a color temperature less than 3,450[K] at which the dimming level of the blue color becomes less than 20%. Consequently, in the foregoing known measure, there are involved such problems that:

a) In the luminaire which stores the quantity-of-light data employing the whole dimming range of the dimmer, there arises a risk that the dimmer cannot be regulated to the dimming ratio below the lower dimming limit of the dimmer itself, in an event where the emission color is regulated on the basis of the detection of the quantity-of-light, and the blended color light cannot be regulated to the set emission color.

b) When the luminaire is limited in the dimming range so as not to use the entire dimming range in order to avoid the above problem a), then the variable range of the blended color light has to be made narrower.

c) When, on the contrary to the above b), the color temperature is set to be further higher than the daylight color (6,250[K]), for example, to be 10,000[K], 20,000[K] or the like, the dimming level of the blue color light source rises to a value closer to 100%. Further, in an event where the color temperature is set to be lower than the electric lamp color (2,950[K]) to be 2,800[K], 2,700[K] or the like, then the dimming level of the red color light source rises to be a value close to 100%. When, at this time, the green color light source provides a more quantity-of-light than the set quantity-of-light due to any fluctuation in the luminous flux, the blended color light is caused to deviate from the set value, and a correction of this respect requires that the dimming level is elevated in respect of the red and blue color light sources concurrently. However, the dimming of the red and blue color light sources has already reached the upper limit of 100% and can no more be raised, and there arises a problem that the blended color light cannot be regulated to the set emission color.

For an arrangement relatively close to the foregoing known measure, it will be possible to enumerate one which has been described in Japanese Patent Laid-Open Publication No. 60-124398 by K. Ban.

SUMMARY OF THE INVENTION

A primary object of the present invention is, therefore, to provide a variable color luminaire which eliminates the foregoing problems, and which allows the quantity-of-light data capable of fully employing the whole dimming range to be prepared without causing the variable color range of the blended color light to be narrowed as restricted by the lower and upper dimming limits of the dimmer, and is capable of preventing any deviation of the blended color light from that of set value even when a dimming quantity of the light sources by virtue of the emission color correction is close to the lower or upper dimming limit.

In order to realize the above object, according to the present invention, a variable color luminaire in which a plurality of light sources of different emission colors are controlled by a dimming means, the quantity-of-light data determinative to dimming quantity of the light sources as well as the dimming quantity of the respective light sources corresponding to emission color and quantity-of-light of a blended color light are stored in a memory means, light outputs of the respective light sources are detected by a detecting means, set quantity-of-light of the respective light sources and detected quantity-of-light as detected by the detecting means are compared at a comparison operation means, the quantity-of-light of the respective light sources is corrected at a correction means in accordance with operational results at the comparison operation means, and the luminaire light is thereby made variable in the emission color and quantity-of-light, is characterized in that, except for one of the light sources, the quantity-of-light of other light sources is subjected to an increase and reduction so as to execute the dimming through a convergence discrimination means until a convergence to a predetermined range is attained.

Other objects and advantages of the present invention shall be made clear in following description of the invention detailed with reference to accompanying drawings.

BRIEF EXPLANATION OF THE DRAWINGS

FIG. 1 consisting of the combination of FIGS. 1A and 1B is a block diagram showing an embodiment of the variable color luminaire according to the present invention;

FIG. 2 consisting of the combination of FIGS. 2A and 2B is a flow-chart of the operation of the luminaire of FIG. 1;

FIG. 3 consisting of the combination of FIGS. 3A and 3B is a block diagram showing another embodiment of the luminaire according to the present invention;

FIG. 4 consisting of the combination of FIGS. 4A and 4B is a flow-chart of the operation of the luminaire of FIG. 3;

FIG. 5 consisting of the combination of FIGS. 5A and 5B is a block diagram showing a further embodiment of the luminaire according to the present invention;

FIG. 6 consisting of the combination of FIGS. 6A and 6B is a flow-chart of the operation of the luminaire of FIG. 5;

FIG. 7 consisting of the combination of FIGS. 7A and 7B is a flow-chart of the operation another embodiment utilizing the luminaire of FIG. 5;

FIG. 8 consisting of the combination of FIGS. 8A and 8B is a flow-chart of the operation in still another embodiment in which the luminaire of FIG. 1 is utilized;

FIG. 9 consisting of the combination of FIGS. 9A and 9B is a flow-chart of the operation in still another embodiment in which the luminaire of FIG. 3 is utilized;

FIG. 10 consisting of the combination of FIGS. 10A and 10B is a flow-chart showing the operation of another embodiment utilizing the luminaire of FIG. 1;

FIG. 11 consisting of the combination of FIGS. 11A and 11B shows in a block diagram a further embodiment of the luminaire according to the present invention;

FIG. 12 consisting of the combination of FIGS. 12A and 12B is a flow-chart of the operation of the embodiment of FIG. 11;

FIG. 13 consisting of the combination of FIGS. 13A and 13B is a flow-chart of another embodiment utilizing the luminaire of FIG. 11;

FIG. 14 consisting of the combination of FIGS. 14A and 14B is a flow-chart of another embodiment of the present invention employing the luminaire of FIG. 11;

FIG. 15 consisting of the combination of FIGS. 15A and 15B is a block diagram showing still another embodiment of the present invention;

FIG. 16 consisting of the combination of FIGS. 16A and 16B shows in a flow-chart of the operation of the embodiment of FIG. 15;

FIG. 17 consisting of the combination of FIGS. 17A and 17B is a flow-chart of the operation in still another embodiment of the present invention in which the luminaire of FIG. 15 is employed;

FIG. 18 consisting of the combination of FIGS. 18A and 18B is a flow-chart of the operation in another embodiment in which the luminaire of FIG. 15 is used; and

FIG. 19 consisting of the combination of FIGS. 19A and 19B is a block diagram showing a further embodiment of the luminaire according to the present invention.

It should be appreciated here that, while the invention should be described with reference to the embodiments shown in the drawings, the intention is not to limit the invention only to the embodiments shown but rather to include all alterations, modifications and equivalent arrangements possible within the scope of appended claims.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring here to FIG. 1, a luminaire equipment 11 of the variable color luminaire according to the present invention comprises light sources 12R, 12G and 12B of mutually different emission colors, and quantity-of-light detectors 13R, 13G and 13B are respectively disposed adjacent to each of the light sources 12R, 12G and 12B. These detectors 13R, 13G and 13B respectively consist preferably of a photodiode, CdS or the like, so that the quantity-of-light of the light sources 12R, 12G and 12B will be successively detected. To the respective light sources 12R, 12G and 12B, light dimmers 14R, 14G and 14B are connected so that the dimming operation will be carried out with dimming signals received from a correction operating means 20. In practice, the correction operating means 20 comprises dimming signal generators 15R, 15G and 15B connected respectively to each of the dimmers 14R, 14G and 14B, and dimming signals for controlling the respective light sources 12R, 12G and 12B to be at optional levels are provided from these dimming signal generators 15R, 15G and 15B.

The variable color luminaire includes a luminaire light setting means 16, for which any arrangement that can appoint addresses of a quantity-of-light data memory 17, such as an up-down counter, switch or the like, may be properly employed, so that predetermined luminaire light color and its quantity-of-light will be set. The quantity-of-light data memory 17 comprises such memory elements as ROM's, in which the data preliminarily computed through a theoretical formula for dimming the respective light sources 12R, 12G and 12B at each of predetermined levels with respect to every address of ROM's in order to obtain the luminaire light of desired emission color are stored in sets respectively for the three colors of R, G and B.

The correction operating means 20 further includes light signal converters 18R, 18G and 18B which convert output signals of the quantity-of-light detectors 13R, 13G and 13B into operated signals. Two comparison operating means 19a and 19b are connected respectively to each pair of dividers 21 and 23 as well as 22 and 24 to receive their output signals to operate a differential amplification. Further, the correction operating means 20 also comprises a quantity-of-light data corrector 25 and a convergence discriminator 26. At the dividers 21 and 22, and R/G operation and a B/G operation of the quantity-of-light data are carried out for preparing reference quantity-of-light ratios to be used upon operation of a quantity-of-light correction, whereas at the dividers 23 and 24 an R/G operation and a B/G operation of the detection signals are carried out to prepare detected quantity-of-light ratios. Thus the quantity-of-light data corrector 25 carries out a comparison operation of the reference quantity-of-light ratios and the detected quantity-of-light ratios of R/G and B/G, and provides as outputs corrected quantity-of-light data with the respective quantity-of-light data on R, G and B corrected. At the convergence discriminator 26, a convergence of the detected quantity-of-light ratios with respect to the reference quantity-of-light ratios is discriminated.

The variable color luminaire shown in FIG. 1 is featured in an arrangement of the quantity-of-light data corrector 25, and the operation of this corrector shall be explained in conjunction with FIG. 2. At the luminaire light setting means 16, a predetermined emission color is set, and the respective quantity-of-light data on R, G and B and stored in the quantity-of-light data memory 17 as set emission colors are read out. Provided here that these quantity-of-light data are V.sub.sr, V.sub.sg and V.sub.sb, these data are provided to the dividers 21 and 22 to be subjected to a setting operation of the reference quantity-of-light ratio, and data V.sub.sr /V.sub.sg and V.sub.sb /V.sub.sg are obtained. On the other hand, the quantity-of-light data V.sub.sr, V.sub.sg and V.sub.sb are input to the quantity-of-light data corrector 25 and thereafter to the respective dimming signals generators 15R, 15G and 15B, which generators provide dimming signals for causing the respective light sources 12R, 12G and 12B to provide the quantity-of-light determined by the quantity-of-light data V.sub.sr, V.sub.sg and V.sub.sb, and the respective light sources 12R, 12G and 12B can be dimmed by such dimming signals. Real quantity-of-light emitted by the light sources 12R, 12G and 12B are detected by the respective quantity-of-light detectors 13R, 13G and 13B and are subjected to photoelectric conversion at the light signal converters 18R, 18G and 18B, of which output signals V.sub.yr, V.sub.yg and V.sub.yb are provided, these output signals are input into the dividers 23 and 24 to be subjected to the operation of the detected quantity-of-light ratios, and such data as V.sub.yr /V.sub.yg and V.sub.yb /V.sub.yg are obtained. Thereafter, the reference quantity-of-light ratios V.sub.sr /V.sub.sg and V.sub.sb /V.sub.sg as well as the detected quantity-of-light ratios V.sub.yr /V.sub.yg and V.sub.yb /V.sub.yg are provided respectively into the comparison operating means 19a and 19b, where the operation for correcting the quantity-of-light is carried out. In these means 19a and 19b, such comparison operation as (the reference quantity-of-light ratio--the detected quantity-of-light ratio), and their outputs V.sub.or and V.sub.ob are as follows:

V.sub.or =(V.sub.sr /V.sub.sg -V.sub.yr /V.sub.yg)

V.sub.ob =(V.sub.sb /V.sub.sg -Y.sub.yb /V.sub.yg)

These outputs V.sub.or and V.sub.ob of the comparison operating means 19a and 19b are input into the convergence discriminator 26, where such discrimination as follows are carried out:

.vertline.V.sub.or .vertline.=V.sub.sr /V.sub.sg -V.sub.yr /V.sub.yg .vertline.>.alpha.1

.vertline.V.sub.ob .vertline.=V.sub.sb /V.sub.sg -V.sub.yb /V.sub.yg .vertline.>.alpha.2

wherein .alpha.1 and .alpha.2 are values closer to zero but may be set to values of a level at which any emission color deviation of the blended color light due to a deviation in the quantity-of-light ratio is not recognizable to users. The values .alpha.1 and .alpha.2 may either be the same value or different values. In an event where .vertline.V.sub.or .vertline..ltoreq..alpha.1 and .vertline.V.sub.ob .vertline..ltoreq..alpha.2 in the convergence discriminator 26, no correction of the quantity-of-light data, and a state in which the quantity-of-light is detected is attained. When .vertline.V.sub.or .vertline.>.alpha.1, on the other hand, it is discriminated that the correction is required in respect of the dimming quantity of the light source 12R of the red emission color R, and the output V.sub.or of the convergence discriminator 26 can be corrected at the quantity-of-light data corrector 25. Assuming that this corrected quantity-of-light data is V.sub.sr ': ##EQU1## wherein "a" is a constant. This also applies to the case of .vertline.V.sub.ob .vertline.>.alpha.2, and a corrected quantity-of-light data V.sub.sb ' of the quantity-of-light data V.sub.sb will be: ##EQU2## These corrected quantity-of-light data V.sub.sr ' and V.sub.sb ' are input into the dimming signal generators 15R and 15B, and the dimming signals are modified, so as to correct the dimming quantities of the light sources 12R and 12B of the emission colors R and B. In an event where, at this time, the light source 12G of the emission color G is unable to attain the quantity-of-light set as the quantity-of-light data due to a reduction in the quantity-of-light, then the correction of the dimming quantity of the light sources 12R and 12B of the emission colors R and B is carried out in connection with the quantity-of-light of the above light source 12G but, when the corrected dimming quantities corrected become lower than the lower limit of the dimming range of the dimmers 14R and 14B, it is no more possible to regulate the quantities of light of R and B. In this case, the convergence discrimination carried out at the convergence discriminator 26 should always result in that:

.vertline.V.sub.or .vertline.=.vertline.V.sub.sr /V.sub.sg -V.sub.yr /V.sub.yg .vertline.>.alpha.1

.vertline.V.sub.ob .vertline.=.vertline.V.sub.sb /V.sub.sg -V.sub.yb /V.sub.yg .vertline.>.alpha.2

It is assumed here that the frequency of carrying out the correction of the quantity-of-light in respect of the light sources of R and B is "J", while the frequency of discriminating that the quantity-of-light also in respect of the light sources of R and B cannot be regulated is "N". As the frequency J of the quantity-of-light correction with respect to R and B is counted at the quantity-of-light corrector 25 and J.gtoreq.N is reached, the lower dimming limit of R and B is discriminated, and the correction of the quantity-of-light of G is carried out when the dimming is discriminated to be close to the lower limit (V.sub.sr '.ltoreq.V.sub.min or V.sub.sb '.ltoreq.V.sub.min).

While in the foregoing arrangement the quantity-of-light correction for G is carried out upon discrimination of the lower dimming limit, the all quantity-of-light correction is stopped at the time when R and B are discriminated not to be at the lower limit since, in this event, too, the blended color light involves a color deviation. The corrected quantity-of-light data V.sub.sg ' of G is made to be

V.sub.sg '=V.sub.sg +.DELTA.V.sub.sg

that is, .DELTA.V.sub.sg is added to the quantity-of-light data V.sub.sg of G, and the dimming signal is modified so as to increase the quantity-of-light of G. Thus, the control is so made that the corrected dimming quantity of R and B will be made higher than the lower dimming limit of the dimmers 13R and 13B. The quantity-of-light of R and B will be repeatedly regulated with respect to the increased quantity-of-light of G, and the respective quantity-of-light correction of R, G and B is carried out until the convergence discriminator 26 discriminates that

.vertline.V.sub.or .vertline.=.vertline.V.sub.sr /V.sub.sg -V.sub.yr /V.sub.yg .vertline..ltoreq..alpha.1, and

.vertline.V.sub.ob .vertline.=.vertline.V.sub.sb /V.sub.sg -V.sub.yb /V.sub.yg .vertline..ltoreq..alpha.2.

By executing the quantity-of-light correction of the respective light sources in this way, it is possible to obtain the blended color light of the preliminarily set emission color. Further, since no color deviation occurs in the emission color even the quantity-of-light data of the respective light sources of the different colors R, G and B are made to employ the whole of the dimming range of the dimmers 14R, 14G and 14B, the variable emission color range is not caused to be narrowed, and the emission colors of a wide range can be obtained.

While in the foregoing the quantity-of-light correction of G has been referred to as being carried out in the event when the frequency J of the quantity-of-light correction of R and B has reached J.gtoreq.N, it is possible to execute the quantity-of-light correction of G in an event where the correction of R and B cannot be executed within a set time t predetermined.

Referring now to FIG. 3, there is shown another embodiment of the luminaire according to the present invention, the operation of which embodiment being shown with a flow-chart of FIG. 4. While the instant embodiment has an arrangement very similar to that of the foregoing embodiment of FIG. 1, differences are present in the manners in which the quantity-of-light ratio is operated and in which the quantity-of-light data of R, G and B are corrected. In the instant embodiment, the quantity-of-light data of the respective light sources 12R, 12G and 12B of R, G and B corresponding to the emission colors set at the luminaire light setting means 16 are read out of the quantity-of-light data memory 17, and the light sources 12R, 12G and 12B of R, G and B are controlled to the predetermined dimming quantity. The quantity-of-light of each of the respective light sources 12R, 12G and 12B is detected at the quantity-of-light detectors 13R, 13G and 13B, and the corresponding detection signals V.sub.yr, V.sub.yg and V.sub.yb are provided as outputs of the light signal converters 18R, 18G and 18B. These detection signals V.sub.yr, V.sub.yg and V.sub.yb are input respectively of the light signal converters 18R, 18G and 18B. These into corresponding dividers 21, 22 and 23, whereas the of the light signal converters 18R, 18G and 18B. These quantity-of-light data V.sub.sr, V.sub.sg and V.sub.sb from the quantity-of-light data memory 17 are also input respectively into each of the dividers 21, 22 and 23, where the quantity-of-light ratio operation is carried out to attain their outputs V.sub.yr /V.sub.sr, V.sub.yg /V.sub.sg and V.sub.yb /V.sub.sb. First two outputs of the dividers 21 and 22 are input into the comparison operating means 19a, and the latter two outputs of the dividers 22 and 23 are input into the other comparison operating means 19b. At these comparison operating means 19a and 19b, the comparison operation of the quantity-of-light ratio is carried out. Assuming that their operation results are V.sub.og and V.sub.ob, they will be

V.sub.og =V.sub.yr /V.sub.sr -V.sub.yg /V.sub.sg

V.sub.ob =V.sub.yr /V.sub.sr -V.sub.yb /V.sub.sb

These outputs of the comparison operating means 19a and 19b are input into the convergence discriminator 26, where the same convergence discrimination as that in the embodiment of FIG. 1 is carried out. At this convergence discriminator 26, the correction of the quantity-of-light data is not required when .vertline.V.sub.og .vertline..ltoreq..alpha.1 and .vertline.V.sub.ob .vertline..ltoreq..alpha.2, and the correction is not carried out. In the case of .vertline.V.sub.og .vertline.>.alpha.1, it is discriminated that the correction of the dimming quantity of the light source 12G of the color G is necessary, and the operation result V.sub.og of the comparison operating means 19a is provided to the quantity-of-light data corrector 25, where the quantity-of-light data V.sub.sg are corrected to be V.sub.sg '=V.sub.sg +a.times.V.sub.og. The same operation is performed in the event of .vertline.V.sub.ob .vertline.>.alpha.2, and the corrected quantity of-light data will be V.sub.sb '=V.sub.sb +a.times.V.sub.ob.

These corrected quantity-of-light data V.sub.sg ' and V.sub.sb ' are provided to the respective dimming signal generators 15R, 15G and 15B, and the dimming signals are modified so as to correct the dimming quantity of the light sources 12G and 12B. Here, as the frequency J of the quantity-of-light correction with respect to G and B becomes J.gtoreq.N and the dimming level of G and B is discriminated to be close to the lower limit, the quantity-of-light of the light source 12R is to be corrected. The corrected quantity-of-light data V.sub.sr ' of the source 12R will be V.sub.sr '=V.sub.sr +.DELTA.V.sub.sr, and the dimming signal is modified so as to increase the quantity-of-light of the light source 12R. While in the foregoing embodiment of FIG. 1 the correction of the quantity-of-light of G has been made in the event when the emission color correction cannot be attained by the quantity-of-light correction of R and B, it is possible as in the present embodiment to carry out the quantity-of-light correction of R when the emission color correction cannot be attained, as will be readily appreciated. And, in the same manner, it is easily understood that it is possible to carry out the quantity-of-light correction of B, when the emission color correction cannot be attained.

Referring next to FIG. 5, there is shown another embodiment of the present invention, the operation of which is as shown by a flow-chart of FIG. 6. In the present instance, similar to the embodiment of FIG. 1, the quantity-of-light of the respective light sources 12R, 12G and 12B is detected, the detection signals are subjected to the operation for obtaining the quantity-of-light ratio, results of this quantity-of-light ratio operation are compared with the reference quantity-of-light ratio to carry out the quantity-of-light correction of the respective light sources 12R, 12G and 12B, and the emission color correction of the blended color luminaire light is carried out. While in the embodiment of FIG. 1 the reference quantity-of-light ratio has been set to be V.sub.sr /V.sub.sg and V.sub.sb /V.sub.sg through the operation carried out with respect to the quantity-of-light data V.sub.sr, V.sub.sg and V.sub.sb stored preliminarily in the quantity-of-light data memory 17, the present embodiment is provided with a reference quantity-of-light ratio data memory 27 for preliminarily storing the set reference quantity-of-light ratio V.sub.sr /V.sub.sg and V.sub.sb /V.sub.sg. This reference quantity-of-light ratio data memory 27 may comprise such memory elements as ROM's similarly to the foregoing quantity-of-light data memory 17, the quantity-of-light data for determining the dimming quantity of the respective light sources 12R, 12G and 12B so as to achieve the set value of the luminaire light are provided out of the quantity-of-light data memory 17 in response to the appointment of the address corresponding to the set value at the luminaire light setting means 16, and the reference quantity-of-light ratio data which are the quantity-of-light ratio of R, G and B in the same colors are provided out of the reference quantity-of-light ratio data memory 27. These reference quantity-of-light data V.sub.sr /V.sub.sg and V.sub.sb /V.sub.sg thus provided out of the memory 27 are subjected at the comparison operating means 19a and 19b to the comparison operation with the operational results V.sub.yr /V.sub.yg and V.sub.yb /V.sub.yg of the detection quantity-of-light ratio repectively operated at the dividers 23 and 24, and the quantity-of-light data V.sub.sr and V.sub.sb of R and B as the result of the above comparison operation are corrected at the quantity-of-light data corrector 25, so as to be such data V.sub.sr ' and V.sub.sb ' as represented by following formulas:

V.sub.sr '=V.sub.sr +a.times.(V.sub.sr /V.sub.sg -V.sub.yr /V.sub.yg)

V.sub.sb '=V.sub.sb +a.times.(V.sub.sb /V.sub.sg -V.sub.yb /V.sub.yg)

These corrected quantity-of-light data V.sub.sr ' and V.sub.sb ' are input into the dimming level discriminator 28, in which the lower limit quantity-of-light value V.sub.min corresponding to the lower limit dimming level of the dimmers 14R and 14B employed in the present embodiment is preliminarily stored. The corrected quantity-of-light data V.sub.sr ' and V.sub.sb ' are compared with the lower limit quantity-of-light value V.sub.min and, when V.sub.sr '.gtoreq.V.sub.min and V.sub.sb '.gtoreq.V.sub.min, the correction of the lu