Classifications

• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
  • H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
  • H05B45/20—Controlling the colour of the light
  • H05B45/24—Controlling the colour of the light using electrical feedback from LEDs or from LED modules
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
  • H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F21—LIGHTING
  • F21Y—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED
  • F21Y2113/00—Combination of light sources
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F21—LIGHTING
  • F21Y—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED
  • F21Y2115/00—Light-generating elements of semiconductor light sources
  • F21Y2115/10—Light-emitting diodes [LED]

Definitions

• the present invention relates to a luminaire, in particular for illumination in enclosed spaces and / or for illuminating objects, having at least two light sources, wherein the light which can be emitted by the light sources has different wavelength ranges.
• the most similar color temperature of an electromagnetic spectrum is given in Kelvin and is a quantity that denotes a particular light color.
• the most similar color temperature of a spectrum e.g., a light source
• the mathematical determination of the most similar color temperature of a light source with known spectral distribution is carried out according to DIN 5033 "Color measurement” with DIN 5031-5 "Radiation physics in the optical domain and lighting technology temperature terms”.
• the most similar color temperature describes whether more long-wave or more short-wave light components are present in the spectrum of a light source.
• the color rendering index of a light source with known spectral distribution is determined purely mathematically in accordance with DIN 6169 "Color Rendering.” These numerical values provide information on the reproduction of the colors of objects that are illuminated by the type of light to be evaluated The theoretical maximum value for the color rendering index is 100. The lower the color rendering index for a particular color, the worse the color rendering property of the light source is for that color. Almost all light sources known in the prior art have deficiencies in color rendering in certain spectral regions. In addition, it often happens that a light source has the necessary light intensity for lighting, but the most similar color temperature is unsuitable for the lighting task.
• Object of the present invention is therefore to improve a generic lamp in such a way that both the "most similar color temperature” and the “color rendering index” for the respective lighting task of the lamp can be improved in the simplest and most energy efficient manner.
• one of the light sources is a main light source having a broader wavelength range and at least one of the light sources is a supplementary light source having a narrower wavelength range and that of the.
• Main light source radiating light flux at least twice, preferably at least 5 times, is as large as the total of the complementary or all supplementary light source (s) radiant luminous flux.
• the invention it is thus provided to specifically correct specific deficits in the light spectrum emitted by a main light source by adding color components to the emitted light by means of one or more supplementary light sources in specific light wave ranges. It has surprisingly been found here that it is sufficient if the supplementary light source (s) has a significantly lower luminous flux than the main light source. In this case, both the color rendering index and the most similar color temperature (ie the light environment) can be influenced in a targeted manner.
• the term luminous flux is used in accordance with DIN5031 "Radiation physics in the optical range and light technology" and describes the electromagnetic radiated power evaluated with the spectral brightness sensitivity of the eye.
• Some types of light sources especially those with high light output, such as low pressure or high pressure gas discharge lamps, have more or less unfavorable color rendering qualities for colored surfaces.
• a correction of the mixed spectrum can be achieved in such a way that a spectrum as level as possible for optimal neutral color reproduction of all possible surface colors is achieved.
• the "spectrum" of the light spectrum can also be increased towards warmer light with larger red proportions (corresponding to a lower most similar color temperature) or towards colder light with larger blue fractions (corresponding to a higher most similar color temperature) in this case, if the main light source and / or the supplementary light source (s), preferably individually, is (dimmable), as this is an adjustment of the spectral composition of the light emitted by the light to the respective lighting task easily and locally possible ,
• the luminous flux which can be emitted by the main light source is at least 10 times, preferably at least 20 times, as large as the total luminous flux which can be emitted by the or all supplementary light source.
• an extremely small proportion of light of the complementary light sources is sufficient to clearly supplement the light emitted overall by the light. Since many main light sources have deficits, especially at the edges of the visible wavelength spectrum of the light, it is often favorable for the supplementary light source to emit light in a wavelength range which lies at the edge of the wavelength range which can be emitted by the main light source.
• the light which can be emitted by the supplementary light source has a wavelength range between 550 and 780 nm, preferably between 600 and 700 nm. If the most similar color temperature and therefore the light spectrum are to be "tilted" into the blue area or if deficits in the main light source are to be improved in this area, then it is favorable if the light which can be emitted by the supplementary light source (s) has a wavelength range between 420 and 520 nm, preferably between 420 and 480 nm
• described measures can be improved not only at the edge of the spectrum of the main light source, but generally in all areas in which the main light source radiates with a reduced intensity. Further features and details of the present invention will become apparent from the following description of the figures. Showing:
• Figures 1 and 2 are schematic representations for the qualitative illustration of the terms “most similar color temperature” and “color rendering index”, Fig. 3 to 3c spectra of various lights according to the invention, Fig. 4a to 4e are schematic representations of different inventive lamp body and Fig. 5a and 5b another Embodiment according to the invention in a front view and a sectional side view.
• the spectral power density P is plotted against the wavelength of the emitted light ⁇ .
• the wavelength is given here in nanometers [nm], while for P a purely qualitative, not necessarily true to scale representation is selected.
• the arrow on the P axis points in the direction of increase of P.
• a high maxima as well as very small minima exhibiting spectrum 8 of a main light source is shown schematically.
• This has a poor color rendering index, since in some light wavelength ranges 9 light components are only to a very limited extent or almost nonexistent.
• the color rendering is very poor, since these long-wave light components are only very weak.
• the illuminated object appears under illumination of such a light source in a different color than in daylight.
• a spectrum with very good color rendering properties for all colors is shown schematically by the curve 13.
• the spectrum 2 shows three different curves of light spectra with a different "most similar color temperature.”
• the spectrum 10 corresponds to a similar color temperature of 3000 Kelvin, the spectrum 11 of 5500 Kelvin and the spectrum 12 of 10,000 Kelvin the curves is a qualitative criterion for the most similar color temperature present in the spectrum has a higher shortwave and thus blue component, while the spectrum 10 has a greater longwave or red component.
• spectrum 11 all wavelength ranges are approximately equally represented.
• the spectrum 8 of a high-pressure mercury metal vapor lamp is shown in dashed lines. This has a significant deficit in the long-wave red area.
• the light of the supplementary light source 2 has a light wavelength range between 580 and 700 nm. In sum, this results in the overall spectrum of 15.
• a red LED is used in the example shown in FIG. 3a with a share of 5-10 percent of the total luminous flux of the lamp.
• Fig. 3b shows in phantom the spectrum 8 of a low pressure mercury metal halide lamp (e.g., a fluorescent tube).
• This spectrum 8 shows significant shortcomings in the short-wave range below 540 nm and in the long-wave range above 620 nm.
• two complementary light sources 2 are provided, which together provide the supplementary light components 14, so that an overall spectrum 15 results with clearly improved color rendering properties both in the blue and in the red region.
• at least one cyan-colored light-emitting diode and one red-light-emitting diode are selected as supplementary light sources 2.
• the cyan as well as the red LEDs each account for 5-10 percent of the total luminous flux of the luminaire.
• Fig. 3c shows how the light of a so-called RGB (red-green-blue) light source can be improved in its color rendering properties.
• RGB red-green-blue
• the spectral view shows that the spectrum of the RGB light source 8 has clear "holes" in the range between 450 and 520 nm and between 550 and 600 nm.
• complementary light sources 2 in the form of cyan and amber (orange) light-emitting diodes with luminous flux components of 10 to 20 percent.
• the overall spectrum 15 produced in this way again has significantly improved color rendering properties and an average similar color temperature.
• FIGS. 4a to 5b show schematically some selected variants.
• the main light source is assigned a separate reflector body 4 in each case.
• the supplementary light sources 2 are arranged around this reflector body 4 around.
• the complementary light sources 2 are arranged slightly withdrawn.
• light guides 5 are provided for transmitting light into the region of the light exit opening 6 or 6 '.
• the light guides 5 may be e.g. be made of acrylic.
• FIG. 4c shows a variant in which the supplementary light source 2 are arranged in recesses of the reflector body 4.
• FIG. 4 d shows an exemplary embodiment in which the main light source 1 and the supplementary light sources 2 lie in a common reflector body 4. This is conveniently equipped with highly reflective surfaces, as is known in the art, to improve the light mixture. As indicated only schematically here, a desired blanking can be ensured by means of apertures 7.
• the supplementary light sources 2 are semiconductor light sources, preferably light-emitting diodes.
• FIG. 4e shows an embodiment in which the main light source 1 is formed by a plurality of white light emitting diodes (LED's). For color enhancement, cyan and red LEDs are embedded as complementary light sources 2 in this array. Overall, this results in turn the ratio of the radiated luminous flux according to the invention.
• FIGS. 5a and 5b show a further exemplary embodiment in which, analogously to FIG. 4a, the supplementary light sources 2 are arranged at the edge of the main light source 1.
• the main light source 1 a high-pressure metal halide lamp with high power is used, the light of which is spectrally enhanced with the red and cyan LEDs 2 used as complementary light sources 2.
• the supplemental light sources 2 are thermally insulated from it.
• the thermal insulation 3 is constructed in the embodiment shown in the form of a multilayer winding of at least two different, alternately arranged materials or films. One of the materials used for this winding is conveniently a polytetrafluoroethylene film.
• the thermal insulation 3 essentially extends, as can be seen in section in FIG. 5b, over the entire area in which the main light source develops high temperatures.
• the slight tilting of the cyan LEDs as shown in FIG. 5a, improves the spatial light mixture.
• the diameter 16 of the light exit openings 6 of the embodiment shown is 25 cm, the overall diameter 17 about 37 cm.
• Both the main light source 1 and the supplementary light sources 2 are preferably individually dimmable, so that the spectral composition of the total emitted light can be easily adapted to the respective lighting task.

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• Non-Portable Lighting Devices Or Systems Thereof (AREA)
• Eye Examination Apparatus (AREA)
• Optical Radar Systems And Details Thereof (AREA)

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Publications (1)

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Cited By (9)

Citations (5)

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• 2004
  • 2004-08-03 ES ES04737405T patent/ES2281806T5/es active Active
  • 2004-08-03 WO PCT/AT2004/000275 patent/WO2005012785A1/de active IP Right Grant
  • 2004-08-03 PL PL04737405T patent/PL1651906T5/pl unknown
  • 2004-08-03 DE DE502004002835T patent/DE502004002835D1/de active Active
  • 2004-08-03 AT AT04737405T patent/ATE353128T1/de active
  • 2004-08-03 EP EP04737405A patent/EP1651906B2/de not_active Not-in-force

Patent Citations (5)

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