JP2013101833A - Luminaire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a luminaire which makes it easy to manage a variation in light color.SOLUTION: The luminaire includes an illumination unit 11 which radiates light in a color temperature range of approximately 4000 to 5000K, of 40≤a≤60 and 20≤b≤30 in a CIELAB space, and assuming a linear line in the CIELAB space to be X=0.3963a-b+5.0412, a normal line distance dx from the linear line X is less than 1.78.

Description

  The present invention relates to a lighting device.

  Among various lighting devices provided with LED elements or the like, ones that place importance on high efficiency are known. As described above, in a lighting device that places importance on high efficiency, the light emission efficiency of the device is good, but there is a possibility that the color rendering property is low and the appearance of the color of the object or the human skin that the light of the lighting device has reached is not faithful.

  Therefore, as disclosed in Patent Document 1, as an illuminating device that emphasizes high color rendering properties, for example, the average color rendering index Ra and the special color rendering index No. 15 (R15) is considered.

In addition to the fact that the skin color can be faithfully seen, there is known an illuminating device in which human skin appears to be a preferable skin color (see, for example, Patent Documents 2 and 3).
The illumination device of Patent Document 2 uses a duv representing a color deviation (deviation from a black body radiation locus) as a parameter, and irradiates light with a duv of 0 or more and 0.01 or less.

  Further, the lighting device of Patent Document 3 uses PS, which is a skin color preference index, of Japanese women as a parameter, and irradiates light with a PS of 80 or more.

JP 2010-176992 A JP-A-8-55610 Japanese Patent Laid-Open No. 11-258047

  By the way, in the illuminating device of patent document 3, the skin color preference index PS of a Japanese woman is used as a parameter to make it appear that human skin is a preferable skin color. However, by adding not only PS parameters but also the above-described duv and color temperature to the parameters, finer settings can be made, and the human skin color can be displayed more preferably.

However, the use of a plurality of parameters may complicate the management of light color variations.
The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an illuminating device capable of facilitating the management of light color variations while improving the appearance of the skin. It is in.

In order to solve the above problems, the lighting device of the present invention has a color temperature of 4000 to 5000 K, 40 ≦ a ^* ≦ 60 and 20 ≦ b ^* ≦ 30 on the CIELAB space, and a straight line on the CIELAB space. X = 0.3963a ^* −b ^* + 5.0412 is provided, and an illumination unit that irradiates light with a normal distance dx from the straight line X being less than 1.78 is provided.

In the above configuration, the illumination unit is configured to satisfy 44 ≦ a ^* ≦ 55 and 21 ≦ b ^* ≦ 27 in the CIELAB space, and the normal distance dx from the straight line X is less than 0.85. It is preferable.

  ADVANTAGE OF THE INVENTION According to this invention, the lighting apparatus which can make easy management of the dispersion | variation in light color can be provided, improving the appearance of skin.

The schematic block diagram of the illuminating device of embodiment. Explanatory drawing for demonstrating the experimental apparatus and experimental method of evaluation experiment. The graph which shows the experimental result of an evaluation experiment. The characteristic view of the spectrum of the illumination part in embodiment. The characteristic view of the spectrum of the illumination part in another example. The graph which shows the experimental result of evaluation experiment of the illuminating device of another example. The characteristic view of the spectrum of the illumination part in the same as the above. The schematic block diagram of the illuminating device in another example. The schematic block diagram of the illuminating device in another example. The schematic block diagram of the illuminating device in another example. The schematic block diagram of the illuminating device in another example.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings.
As shown in FIG. 1, the illuminating device 10 of this embodiment is provided with the illumination part 11 which irradiates light outside, and the lighting circuit 12 for making this illumination part 11 light.

  The illumination unit 11 includes one LED element 11a that is electrically connected to the lighting circuit 12, and one phosphor 11b that covers the LED element 11a and a predetermined gap and emits substantially yellow light. It is configured. And based on the electric power supply from the lighting circuit 12, the illumination part 11 lights up substantially white.

Next, the spectral characteristics of the illumination unit 11 of the illumination device 10 will be described.
The inventor of the present invention proposes a skin color preference index PS of Japanese women advocated by Tadashi Yano and the color deviation so that the light emitted from the illuminating unit 11 makes the color of human skin look good. An evaluation experiment was performed using duv representing (deviation from the black-body radiation locus) and color temperature as parameters.

  In this evaluation experiment, as shown in FIG. 2, the device A that can freely realize the light of the illumination unit 11 by controlling the wavelength is used to irradiate light around the cheek M1 of the model M in the dark room B. Various skin colors of M were realized, and it was evaluated whether or not a plurality of evaluators H outside the darkroom B looked preferable for each skin color of the model M.

Each parameter used in this evaluation experiment was set as follows.
First, PS is set in the range of 80-100. This is because the reference value of PS proposed by Tadashi Yano et al. Is 80, and it is desirable that the reference value be 80 or more. Incidentally, as a method for calculating PS, for example, as disclosed in Japanese Patent Application Laid-Open No. 11-258047, after obtaining a calculation evaluation value P relating to skin color preference, the preference for skin color from 4 × 5 ^P is obtained. The index PS can be calculated.

  And duv is set in the range of -0.01 to 0.005. The color temperature is set in the range of 4000K to 5000K, which is considered to be frequently used at present. In consideration of manufacturing variations, the range of the color temperature variation is determined from the color temperature discrimination threshold, and is set to a range of about 3915K to 5140K.

Then, when setting each parameter for the evaluator H, “Very favorable”, “Very preferable”, “Slightly preferable”, “Neither”, “Slightly unfavorable”, “Very not preferable”, “ The evaluation was carried out in 7 grades “very unfavorable”. The result of the evaluation experiment is shown in FIG. FIG. 3 is plotted on the (a ^* , b ^* ) axis of the CIELAB space, with a ^{* on} the horizontal axis and b ^* on the vertical axis. Further, in FIG. 3, when the evaluation values of “7” to “1” are set in order from the seven levels “preferably” to “very not preferable”, which are the levels of preference used in the evaluation experiment. The white squares indicate the conditions under which evaluations of preference 4.9 or higher were obtained. Similarly, the conditions under which evaluations of preference 4.0 or more and less than 4.9 were obtained are indicated by white diamonds in FIG. 3, and the conditions under which evaluations of preference 4.0 were obtained are shown in FIG. Indicated by white triangles.

  First, Formula 1 which shows the straight line X (refer FIG. 3) linearly approximated based on the result by which evaluation with preference 4.9 or more was obtained by evaluation experiment is derived | led-out.

Next, a distance dx in the normal direction orthogonal to the straight line X is defined.

Then, when the range of the distance dx in the normal direction is set in consideration of the result shown in FIG. 3, by setting the distance dx <1.78, while eliminating the condition of the preference less than 4.0, A condition of preference 4.0 or higher is included. At this time, the coordinates (a ^* , b ^* ) of the CIELAB space are in the range of 40 ≦ a ^* ≦ 60 and 20 ≦ b ^* ≦ 30.

Next, FIG. 4 shows an example of the spectral characteristic (action) of the illumination unit 11 in accordance with the evaluation experiment.
The illumination unit 11 having the spectral characteristics shown in FIG. 4 is set such that PS is 96, duv is −0.004, and color temperature is 4118K. As shown in FIG. 4, the illumination unit 11 has a first peak wavelength P1 in the vicinity of about 450 nm that is between 410 and 470 nm, and the second peak in the vicinity of about 610 nm that is between 580 and 630 nm on the longer wavelength side. It is set as the structure which has the peak wavelength P2. The illumination unit 11 is configured such that the relative spectral intensity at the first peak wavelength P1 is higher than the relative spectral intensity at the second peak wavelength P2. More specifically, when the relative spectral intensity at the first peak wavelength P1 is 1, the relative spectral intensity at the second peak wavelength P2 is set to approximately 0.85.

By configuring the illumination unit 11 in this way, (a ^* , b ^* ) = (51.65, 24.30) in the CIELAB space, and the range of 40 ≦ a ^* ≦ 60, 20 ≦ b ^* ≦ 30 Is done. Further, since the distance dx = 1.12 in the normal direction orthogonal to the straight line X represented by (Expression 1), dx <1.78 is satisfied. For this reason, the light irradiated from the illumination unit 11 can have a color temperature of 4118K in the range of about 4000 to 5000K and a preference of 4.0 or more.

Next, characteristic effects of the present embodiment will be described.
(1) The color temperature is in the range of about 4000 to 5000 K, 40 ≦ a ^* ≦ 60 and 20 ≦ b ^* ≦ 30 on the CIELAB space, and the straight line on the CIELAB space is represented by X = 0.3963a ^* −b ^* The illumination unit 11 irradiates light with a normal distance dx from the straight line X of less than 1.78. For this reason, it is possible to radiate light having a preference of 4.0 or more. In addition, since the skin color can be favorably displayed with one index instead of the three parameters of PS, duv, and color temperature, it is possible to easily manufacture the lighting device and manage the variation of the light color.

In addition, you may change embodiment of this invention as follows.
In the above embodiment, the spectral characteristics of the illumination unit 11 are configured as shown in FIG. 4, but the present invention is not limited to this. For example, the illumination unit 11 may be configured to have spectral characteristics as shown in FIG. As shown in FIG. 5, the illumination unit 11 has a first peak wavelength P1 in the vicinity of about 470 nm that is between 410 and 470 nm, and the second in the vicinity of about 610 nm that is between 580 and 630 nm on the longer wavelength side. It is set as the structure which has the peak wavelength P2. As described above, the spectral characteristic is merely an example, and the spectral characteristic is not particularly limited as long as the coordinates in the CIELAB space are in the range of 40 ≦ a ^* ≦ 60 and 20 ≦ b ^* ≦ 30.

In the above embodiment, the coordinates in the CIELAB space are in the range of 40 ≦ a ^* ≦ 60, 20 ≦ b ^* ≦ 30. For example, as shown in FIG. 6, 44 ≦ a ^* ≦ 55, 21 ≦ b ^*. A range of ≦ 27 and a normal distance dx <0.85 are preferable. With such a configuration, light with a preference of 4.9 or more can be irradiated. An example of the illumination unit 11 that meets such conditions is shown in FIG. The illumination unit 11 having the spectral characteristics shown in FIG. 7 is set such that PS is 94, duv is −0.004, and the color temperature is 4901K. As shown in FIG. 7, the illumination unit 11 has a first peak wavelength P1 in the vicinity of about 450 nm that is between 410 and 470 nm, and the second peak in the vicinity of about 630 nm that is between 580 and 630 nm on the longer wavelength side. It is set as the structure which has the peak wavelength P2. Further, the illumination unit 11 has a third peak wavelength P3 in the vicinity of about 560 nm between the first peak wavelength P1 and the second peak wavelength P2. The illumination unit 11 is configured such that the relative spectral intensity at the first peak wavelength P1 is higher than the relative spectral intensity at the second peak wavelength P2 and the third peak wavelength P3. More specifically, when the relative spectral intensity at the first peak wavelength P1 is 1, the relative spectral intensity at the second peak wavelength P2 and the third peak wavelength is approximately 0.6. The By configuring the illumination unit 11 in this way, (a ^* , b ^* ) = (51.67, 24.97) in the CIELAB space, and 44 ≦ a ^* ≦ 55 and 21 ≦ b ^* ≦ 24 Is done. Further, since the distance dx = 0.51 in the normal direction orthogonal to the straight line X represented by (Expression 1), dx <0.85 is satisfied.

In the above embodiment, the predetermined gap is provided between the LED element 11a and the phosphor 11b. However, a configuration in which the phosphor is applied to the LED element 11a may be employed.
In the above embodiment, the illumination unit 11 is configured by one LED element 11a and one phosphor 11b. However, the present invention is not limited thereto, and may be appropriately changed according to specifications and the like. As a modified example of the illumination unit 11 that is lit in substantially white, the following configuration is conceivable. However, the present invention is not limited to this as long as the present invention is applicable.

  For example, as shown in FIG. 8, in addition to one LED element 11a and one phosphor 11b covering the element 11a, a configuration including an LED element 20 having a peak wavelength different from that of the LED element 11a may be employed. .

  Further, as shown in FIG. 9, in addition to one LED element 11a and one phosphor 11b covering this element 11a, the LED element 21a and the phosphor 11b, which have substantially the same peak wavelength as the LED element 11a, You may employ | adopt the structure provided with different fluorescent substance 21b.

  Further, as shown in FIG. 10, a blue LED element 22a and a phosphor 22b that covers the element 22a and emits red light, and a blue LED element 23a and a phosphor 23b that covers the element 23a and emits green light. The illumination unit 11 may be configured with the blue LED element 24.

Moreover, as shown in FIG. 11, you may comprise the illumination part 11 by the blue LED element 25, the green LED element 26, and the red LED element 27. As shown in FIG.
Further, the illumination unit 11 may be configured using a transmission / diffusion filter, and for example, a configuration that satisfies the spectral characteristics as illustrated in FIG. 4 may be employed.

  DESCRIPTION OF SYMBOLS 10 ... Illuminating device, 11 ... Illumination part, X ... Straight line, dx ... Distance.

Claims (2)

The color temperature is 4000 to 5000 K, 40 ≦ a ^* ≦ 60 and 20 ≦ b ^* ≦ 30 on the CIELAB space, and the straight line on the CIELAB space is X = 0.3963a ^* −b ^* + 5.0412 ^. An illumination device comprising an illumination unit that emits light having a normal distance dx from X of less than 1.78. The lighting device according to claim 1.
The illumination unit is configured to satisfy 44 ≦ a ^* ≦ 55 and 21 ≦ b ^* ≦ 27 on the CIELAB space, and the normal distance dx from the straight line X is less than 0.85. A lighting device.