PHOTOBIOLOGICALLY FRIENDLY CONVERSION LEDs

Technical field

The present invention relates to light sources having a spectral spectrum suitable for outdoor illumination and having little interference with the human circadian rhythm, more particularly, the present invention discloses LEDs consisting of a shortwave emitting semiconductor electroluminescent structure and an inorganic phosphor generating an orange component of spectral power.

Definitions:

CIE - International Commission on Illumination (Commission Internationale de l'Eclairage);

CIE standard luminaire A is a spectral power distribution corresponding to black body radiation at 2856 K.

CPF - Circadian Effect Factor (ratio of non-visual circadian efficacy of radiation to luminous efficacy);

Phosphorus is a substance that converts radiation of a shorter wavelength into radiation of a longer wavelength (otherwise known as a luminophore);

"Flame light" means a light of low coupled color temperature (<2500 K) with a color similar to that of black body radiation;

SAR - color rendering index;

SGS - spectral power distribution;

SST - associated color temperature;

LED - LED;

Description of the Related Art

In the case of daylight darkness, it is necessary to consider the effect of light on the human biological (circadian) rhythm. Man, like every mammal, has its own circadian rhythm that regulates the human sleep and wakeful phase [D. Lang, Energy efficient illumination for biological clock, Proc. of SPIE 7954, p. 795402-1-12 (2011)]. Already in the last century, the human circadian rhythm has been associated with illumination, and in 2001, it was discovered that the rhythm is regulated by ganglion cells in the lower retina of the eye [GC Brainard, J.P. Hanifin, J.M. Greeson, B.Byrne, G.Glickman, E. Gerner,

MD Rollag, Action spectrum for melatonin regulation in humans: Evidence for a novel circadian photoreceptor, J. Neurosci. 21 (16), p. 6405-6412 (2001); K. Thapan, J. Arendt, DJ Skene, An action spectrum for melatonin suppression: evidence for a novel non-rod, non-cone photoreceptor system in humans, J. Physiol. 535 (1), p. 261267 (2001)]. These cells are non-imaging photoreceptors which, together with the cerebral nucleus and the pineal gland, form the non-imaging pathway for circadian rhythm regulation.

When the eye is illuminated with blue light, especially from above, these ganglion cells generate a signal to the superficial nucleus in the brain, which acts to inhibit the release of melatonin (a sleep hormone and a natural oncostatic agent) into the pineal gland. This makes people feel active in high light during the day or in the morning. Meanwhile, in the evening, when the sun goes down, melatonin release is not suppressed and people are getting ready for sleep. Research has shown that disturbance of circadian rhythm and inhibition of melatonin release in the evening can cause a variety of medical conditions, such as increased risk of cancer [S. Davis, D. K. Mirick, Circadian disruption, shift work and the risk of cancer: a summary of evidence and studies in Seattle, Cancer Causes Control 17 (4), p. 539-545 (2006)]. Therefore, it is important to ensure that the light used to illuminate the streets, parking lots, pedestrian and bicycle paths, building facades, monuments, parks, parking lots, and courtyards in the evening and during the first half of the night does not have a significant circadian effect. U.S. Patent No. 6,498,429 discloses a high-pressure sodium lamp and U.S. Patent 4,401,914 a low-pressure sodium vapor lamp. These discharge lamps are showers, have a slow ignition time and relatively low luminous efficacy, and contain toxic and chemically aggressive substances. High- and low-pressure sodium vapor lamps have low SST and low circadian effects, but have poor color rendering due to their poor and structured spectrum.

U.S. Patent No. 2,001,501 discloses a mercury vapor lamp. This lamp emits a high beam flux in the blue region and strongly influences the human circadian rhythm, and at low ambient luminance, high SST can cause visual discomfort [AA Kruithof, Tabular luminescence lamps forgeneral illumination, Philips Tech. Rev. 6, p. 65-73 (1941).].

U.S. Patent No. 6,504,179 discloses a tricolor phosphor conversion lamp consisting of a semiconductor chip emitting light in the wavelength range of 300 to 470 nm, a portion of which is converted to green light in European-activated calcium magnesium chlorosilicate phosphorus and yellow light in cerium-activated rare earth. The combination of these three colors is perceived by the person as white light, but such light is not optimal for photobiologically friendly street lighting, for the following reasons:

the SGS of an optimum photobiologically friendly LED consists of two spectral components, and the patent describes an SGS LED consisting of three spectral components;

the phosphor composition of the luminaire is not selected so that the SGS is optimal for outdoor illumination with minimal circadian impact factor.

U.S. Patent No. 6,501,102 discloses a tricolor phosphor conversion lamp consisting of a semiconductor chip emitting light of less than 460 nm, the portion of which is converted into secondary and tertiary radiation by phosphorus, at least one of which is a compound of yttrium alumina. , strontium gallium sulfide, yttrium aluminum lanthanum oxide compound, yttrium aluminum lanthanum gallium oxide compound, strontium sulfide and nitridosilicate. The combination of these three colors is perceived by the person as white light, but such light is not optimal for photobiologically friendly street lighting, for the following reasons:

the SGS of an optimum photobiologically friendly LED consists of two spectral components, and the patent describes an SGS LED consisting of three spectral components ;

the phosphor composition of the luminaire is not selected so that the SGS is optimal for outdoor illumination with minimal circadian impact factor.

U.S. Patent No. 6,294,800 discloses a phosphorus having the chemical composition of Ca8Mg (SiO4) 4Cl2: Eu.²⁺, Mn²⁺ and a tricolor phosphor conversion LED consisting of a semiconductor chip emitting light having a wavelength in the range of 330-420 nm, said Ca8Mg (SiO4) 4Cl2'.Eu²⁺, Mn²⁺ of phosphorus, in which part of the initial radiation is converted to green light, Y2C> 3: Eu³⁺, Bi³⁺ of phosphorus in which part of the initial radiation is converted to red light and BaMg2Ali6O27: Eu²⁺ or (Sr, Ba, Ca)₅(PO4) 3 Cl: Eu²⁺ phosphorus, in which part of the original radiation is converted into blue light. The combination of these three colors is perceived by a person as white light, but is not optimal for photobiologically friendly street lighting, for the following reasons:

the SGS of an optimum photobiologically friendly LED consists of two spectral components, and the patent describes an SGS LED consisting of three spectral components;

the phosphor composition of the luminaire is not selected so that the SGS is optimal for outdoor illumination with minimal circadian impact factor.

U.S. Patent No. 6,084,250 discloses a tricolor phosphor conversion lamp, which consists of a GaN light emitting in the ultraviolet region with a peak wavelength between 300 and 370 nm and a blue BaMgAI.₁₀Oops₇: Eu²⁺ of phosphorus, which converts the original radiation into a radiation having a peak in the range 430-490 nm, green ZnS: Cu phosphorus, which converts the original radiation to a radiation having a peak in the range of 520-570 nm and red Y₂O₂S of phosphorus in which the original radiation is converted to radiation in the range of 590-630 nm. The combination of these three colors is perceived by a person as white light, but is not optimal for photobiologically friendly street lighting, for the following reasons:

the SGS of an optimum photobiologically friendly LED consists of two spectral components, and the patent describes an SGS LED consisting of three spectral components;

the phosphor composition of the luminaire is not selected so that the SGS is optimal for outdoor illumination with minimal circadian impact factor.

U.S. Pat. No. 5,851,063 describes a matrix of purely electroluminescent LEDs of different colors, which are intended to produce the desired light source SGS). However, such arrays require the sophisticated topology required for the arrangement of the different groups of lights. In addition, purely electroluminescent lamps of different colors are powered by different currents, which requires a greater number of control channels and more sophisticated electronic circuits than phosphor conversion, when the electroluminescent structure is the same in all lamps.

The main prototype of the present invention is described in U.S. Patent No. 5,998,925. The luminaire described in this patent consists of a semiconductor light emitting component and a phosphor. In this case, the semiconductor chip is composed of ln / Ga / M & N (0 <i, 0 £ j, 0 <k, and i + j + k = 1), and phosphorus is a grenade activated material containing at least one element of cerium. of the two groups consisting of elements of Y, Lu, Se, La, Gd, Sm and Al, Ga, In. The semiconductor chip emits excitation light in the 400-530 nm wavelength range, and the phosphor photoluminescence is chosen so that its spectral peak wavelength is greater than the excitation light. However, the use of such luminaires in outdoor lighting does not avoid the following disadvantages:

the SGS of the luminaire is not optimized in such a way that the circadian effect factor of the emitted light is minimized, ie the negative impact on human organogenesis in the evening or at night is minimized;

the phosphor chemical composition of the luminaire is not selected so that the SGS is optimal for outdoor illumination with minimal circadian impact factor.

Mesopic vision can be used to reduce the non-visual effects of outdoor lighting and to avoid sophisticated design and electronics (when the average ambient luminance varies between 0.01 and 10 cd / m)²) optimized phosphorous solid-state flame light sources with a non-visual circadian effect several times smaller than conventional daylight luminaires [A. Žukauskas, R. Vaicekauskas, P. Vitta, Optimization of Solid State Lamps for Photobiologically Friendly Mesopic Lighting, Appl. Optics 51 (35), p. 8423-8432 (2012)]. This source presents the concept of a two-color light source with optimized LED SGS models with the lowest non-imaging effect and the highest light efficiency in the mesopic area. Such sources exhibit moderate color rendering, which is suitable for many outdoor lighting applications due to reduced color discrimination at dusk.

The invention discloses a low coupled color temperature (flame light) illuminator having a spectral power distribution composed of blue and orange components. These components have peak wavelengths and beam flux ratios so selected that the excitation ratio between the extracellular photoreceptors that regulate circadian rhythm of the eye and the visual photoreceptors that cause visual perception is the lowest. In this way, the least disturbance of the human circadian rhythm is achieved. The ratio of the spectral components of the spectral flux can be determined by varying the current feeding to the electroluminescent structure or by selecting the size and concentration of phosphor particles, wavelength transducer thickness, refractive index between wavelength transducer and electroluminescent outside the luminaire housing.

Such phosphor conversion lamps can be used for a variety of outdoor lighting applications (street, courtyard, pedestrian and bicycle paths, home facades, monuments, parks, parking lots, and home yards) in the evenings and in the first half of the night.

The essence of the invention

It is an object of the present invention to provide a small non-visual photobiological effect conversion phosphor illuminator in which a partial conversion of blue light or near-ultraviolet (UV) light in a wavelength converter is used such that the resulting light has a spectral component with a peak at 570-600 nm. spectral component with a peak in the 400-500 nm wavelength range, so that the color coordinates of the light spectrum correspond to the absolute black body radiation in the low (15003000 K) SST region.

The object of the present invention is achieved by a two-color (blue-orange) illuminator having a semiconductor chip which, due to injection electroluminescence and photoluminescence, generates a shorter wavelength than 500 nm for converting said radiation into longer wavelengths in length, and which has one type (for partial conversion) or two types (for complete conversion) of phosphorus particles. What's new is that the LED emits a mixture of blue and orange light in the transducer containing one of the orange phosphores listed below. This orange component, together with the blue component, forms a SGS of flaming light with low non-visual circadian exposure in humans. The phosphorus emitted in the orange spectral region may be as follows:

- Yttrium magnesium aluminum silicon garnet activated by trivalent cerium ions Y₃Mg₂AISi₂O₁₂: Ce³⁺,

- Barium strontium silicon nitride activated by divalent europium ions (Ba, Sr)₂Si₅N₈: Eu²⁺,

- barium strontium orthosilicate activated by divalent europium ions

Ί (Ba, Sr) SiO4'.Eu²⁺,

- calcium-alpha-silicon aluminum oxynitride doped with divalent europium ions Ca-a-SiAION: Eu²⁺,

- Calcium strontium selenide doped with divalent europium ions (Ca, Sr) Se: Eu²⁺.

In the case of partial conversion, the semiconductor chip generates blue light in the 400-500 nm spectrum, and the converter contains phosphorus, which is characterized by the partial conversion of this light into longer-wave (orange) light. In this case, the semiconductor chip has an active layer made of ln_xGai-_xN semiconductor alloy.

In the case of full conversion, the semiconductor chip generates near-UV or blue (violet) light with a wavelength of less than 450 nm, and the transducer has a second phosphor that exhibits luminescence in the 400-500 nm spectral band and can be an oxide, halo, or nitride compound, activated by divalent europium, divalent manganese, divalent tin, or trivalent cerium ions. In this case, the semiconductor chip has an active layer made of GaN semiconductor compound, or_xGai-_xN, Al_yGai-_yN or Al_yln_xGai-_x-_yN semiconductor alloy.

In any of the above cases where the LED emits multiple spectral components, the spectral flux and peak wavelengths of each spectral component are selected such that the final spectral composition of the emitted light is suitable for photobiologically friendly field illumination, i.e. low temperature (1500 - 3000 K) radiation, and SGS would have a relatively low non-visual circadian effect.

The low non-visual circadian effect is a SGS whose blue-spectrum component has a fluorescence of the orange spectrum component of a ratio of no more than 1:17 for partial conversion luminaire and no more than 1:15 for full conversion luminaire of SST = 2000 K and up to 1: 5 for partial conversion LED and up to 1: 4 for full conversion LED when SST = 3000 K

The ratio of the radiation flux components is determined by selecting the size and concentration of the phosphor particles, the wavelength transducer thickness, the refractive index of the wavelength transducer material, the distance between the wavelength transducer and the electroluminescent structure and the position of the wavelength transducer in the luminaire housing.

In the case of an optically small non-visual illuminator, the light spectrum components generated have the following wavelengths:

about 585 ± 20 nm for the orange spectrum component and about 450 ± 20 nm for the blue spectrum component.

Brief description of the drawings:

Fig. - photopic and scotopic functions of spectral luminous efficiency and spectral circadian efficiency;

Fig. - a basic arrangement of a partial conversion of blue light into phosphor for a photobiologically friendly field illumination (100);

Fig. - a basic arrangement of a full conversion phosphor light (200) for dipped UV light for photobiologically friendly outdoor illumination;

Fig. - Typical electroluminescence spectra of a semiconductor chip with an InGaN active layer: (a) 450 nm blue emitter; (b) 365 nm emitter in the near UV region;

Fig. - Typical photoluminescence spectra of inorganic phosphorus: (a) orange emitter; (b) blue emitter;

Fig. - SGS for Fluorescent Conversion Fluorescent Lamps for Photobiologically Friendly Outdoor Lighting: (a) Partial Conversion Lights with Orange Phosphor: Y₃Mg₂AISi₂0i₂: Ce³⁺, (Ba, Sr) 2Si5N8: Eu²⁺, (Ba, Sr) 2SiC> 4: Eu²⁺, Ca-aSiAION: Eu²⁺, (Ca, Sr) Se: Eu²⁺; (b) Full conversion luminaire with blue BaMg2AI16O27: Eu²⁺ and in Y3Mg orange₂AISi₂0i₂: Ce³⁺ phosphorus.

Detailed Description of the Invention

Semiconductor luminaires are increasingly being used in outdoor lighting as energy-efficient smart lighting systems are being developed. They are high-performance, long-lasting, have the flexibility to select the SGS they need, are quick to switch and smooth, have no sudden burnout, require no high power, and are compatible with computer control technologies.

The proposed two-component flameproof luminaire has a low non-visual circular effect, which SGS is optimized for light efficiency. Since the luminous efficiency of a light source is the product of the luminous efficiency of the light generated and the luminous efficiency of the source, optimization based on the luminous efficiency, which depends solely on SGS, is universal. Meanwhile, the luminous efficiency of LEDs depends on injection performance, internal quantum efficiency, light escape performance, and consistent impedance - parameters that are constantly improving as LED technology evolves [P. Mottier, LEDs for Lighting Applications, John Wiley & Sons, Ine, London, (2009)].

For photopic (day) vision, the luminous efficacy is:

where S (4) is the SGS of the illuminator, Λ is the wavelength, and V (A) is the spectral luminous efficacy of photopic vision as defined by CIE in 1924, which is the maximum possible luminous efficacy of 683 lm / W for photopic vision.

Photopic vision occurs in environments with average (adaptation) luminance greater than 10 cd / m². Under these conditions, the visual sensation is determined by the three types of photoreceptors in the retina of the eye - cones, so photopic vision is color-coded. When the luminance values ​​of the adaptation do not exceed 0.01 cd / m², the visual sensation is caused by one type of photoreceptor, the stalks, which results in the loss of the ability to distinguish colors at low luminance values. In this case, the sensitivity function of the eye is described by the spectral luminous efficiency function V '(A) of the scotopic vision defined in CIE 1951. The maximum possible light efficiency for scopic vision is 1700 lm / W. The spectral luminous efficiency functions for photopic and scopic vision are shown in Fig. 1.

Offered for outdoor lighting, the proposed luminaire is optimized for intermediate, mesopic, vision with an average luminance of 0.01 cd / m² and 10 cd / m². This area of ​​luminance covers the range of 0.1 cd / m used for street and pedestrian lighting² up to 2 cd / m². In this case, the visual sensation is determined by both the stalks and the cones, the color difference is less pronounced, and the mesopic function of the spectral luminous efficiency \ Z_us(4) depends on the luminance of the environment. The spectral sensitivity of mesopic vision is intricately dependent on the luminance of the adaptation and is described in various models. This is based on the CIE recommended MES-2 photometric system [Commission Internationale de l'Eclairage, Recommended system for mesopic photometry based on visual performance, Pub. CIE 191: 2010.]. Under this system, the spectral luminous efficacy function of mesopic vision is expressed as follows:

[zwK (2> (i- (2) where M (m) is the rationing function, om is the luminance multiplier. For mesopic vision, the luminous efficacy is calculated as follows:

^Λ us ^Λ mesO

J SŲ.yl /.

here is the highest possible mesopic luminous efficacy K_meit depends on the ambient luminance and varies from 1700 lm / W to 683 lm / W.

The ganglion cells responsible for the non-visual circadian effects of light have their spectral sensitivity, as do the image receptors. This spectral sensitivity is described by the circadian efficiency function C (4), which is depicted in Fig. 1. It is seen that the peak of this function is approximately 460 nm, so that the circadian rhythm is most affected by blue light [D. May, Circadiane LichtgroBen und deren messtechnische Ermittlung, Licht 54, p. 1292-1297 (2002).

Non-visual circadian effect of the proposed outdoor lighting fixture, estimated by calculating the circadian impact factor (CPF) for mesopic conditions characteristic of artificial outdoor lighting_mes · This factor is defined as the ratio of the non-visual circadian efficiency of radiation to the mesopic efficiency of light:

_K_c _ 7C JC (2) 5 (2) J2 ' ^<4) here K_cq equals 683 blm / VV [A. Žukauskas, R. Vaicekauskas, P. Vitta, Optimization of Solid State Lamps for Photobiologically Friendly Mesopic Lighting, Appl. Optics 51 (35), p. 8423-8432 (2012)].

The CPF value is suitable for comparing the non-visual circadian effects of light sources.

For outdoor outdoor lighting, as low as possible a_c, we value it because it requires as much light as possible and circadian efficiency as low as possible. The lowest CPF value is characterized by a two-color light source with a shortwave component peak at about 440-460 nm and a longwave component peak at about 570-600 nm [A. Žukauskas, R. Vaicekauskas, P. Vitta, Optimization of Solid State Lamps for Photobiologically Friendly Mesopic Lighting, Appl. Optics 51 (35), p. 8423-8432 (2012)]. The SGS of the proposed luminaire was optimized to look for a minimum CPF value.

The proposed outdoor lighting luminaire is superior to conventional outdoor lighting sources (high and low pressure sodium vapor lamps) and has a color rendering capability. Color rendering can be estimated by the overall color rendering index (SAR) R_aintroduced by the CIE in 1965 and revised in 1995 in its evaluation procedure [Commission Internationale de l'Aclairage, Method for measuring and specifying color rendering properties of light sources, Pub. CIE 13.3: 1995]. 8 main color samples are used in the procedure; each sample is illuminated by a reference and test light source. After analyzing the reflected light spectra, a color difference is calculated, which is used to find a specific color rendering index for each sample. The average SAR of the following eight specific color-specific recovery rates is obtained:

R = 100-4,6 where ΔΕ is the mean color shift of the eight color samples at CIE 1964. color space [Commission Internationale de l'Eclairage, Method of measuring and specifying color rendering properties of light sources, pub. CIE 13.3: 1995]. The SAR value is 100 at the maximum and is incandescent and halogen. In the field of mesopic luminance, the ability of a person to distinguish colors is known to be impaired [WRJ Brown, The Influence of Luminance Level on Visual Sensitivity to Color Differences, J. Opt. Soc. Am. 41, p. 684-688 (1951)], so the mesopic SAR F?_a, we can be described a little differently and depend on the luminance [A. Žukauskas, R. Vaicekauskas, P. Vitta, Optimization of Solid State Lamps for Photobiologically Friendly Mesopic Lighting, Appl. Optics 51 (35), p. 8423-8432 (2012)]:

^_us= 100-4.6y (Z_us) J £, ₍₆₎ where y is a factor depending on the luminance L of the environment_us.

The proposed illuminator (100, 200) is comprised of a semiconductor chip (1, 11), by means of electroluminescence generating shortwave radiation at a wavelength of less than 500 nm, which is contained in a reflector cup (2, 12) and connected to the terminals (3, 13). ) using wire (4, 14). The chip (1, 11) is covered by a wavelength transducer (5, 15) enclosed in a transparent housing (6, 16). Said transducer is for converting said shortwave radiation into longer-wave radiation due to photoluminescence to obtain photons (10, 20, 22), where it contains one type of phosphor particles (7) for partial conversion and two types of phosphor particles for complete conversion. (17.18).

The proposed blue light partial conversion phosphor illuminator (100) has a semiconductor chip (1) emitting blue light in a 400-500 nm spectral band that is aligned with the phosphor absorption spectrum of the transducer (5). A certain portion of the primary flux is converted by the appropriate phosphorus (7) into orange light in the 570-600 nm spectral band. Such phosphorus may be yttrium magnesium aluminum silicon garnet activated by trivalent cerium ions (Y3Mg2AISi2O12.Ce³*), barium strontium silicon nitride activated by divalent europium ions ((Ba, Sr) 2Si5N8: Eu²⁺), barium strontium orthosilicate activated by divalent europium ions ((Ba, Sr) SiO4: Eu²⁺), calcium-alpha silicon aluminum oxide nitride doped with divalent europium ions (Ca-a-SiAION: Eu²⁺) or calcium strontium selenide doped with divalent europium ions ((Ca, Sr) Se: Eu²⁺). The rest of the primary blue light remains undigested. By mixing the blue and orange spectral components in a beam flux ratio of about 1:17, one obtains a spectrum corresponding to the color of the black body radiation, which is perceived by a person as low CCT white or flame light.

The proposed dipped UV full phosphor luminaire (200) has a semiconductor chip (11) emitting dipped UV, violet or blue light with a wavelength of less than 450 nm. This light is consistent with the absorption spectra of the phosphorus and is fully convertible in a wavelength converter (15). As with partial conversion, the converter (15) contains phosphorus (17) for converting shortwave radiation to orange light in the 570-600 nm spectrum. In addition, the transducer (15) contains phosphorus (18), which converts shortwave radiation into blue light, in the 400-500 nm spectral band. Such phosphorus may be an oxide, halooxide, or nitride compound activated with divalent europium, divalent manganese, divalent tin, or trivalent cerium ions. For example, the blue component can be generated in inorganic phosphorus such as

CaMgSi₂O₆: Eu²⁺, Ba5SiO4Cl6: Eu²⁺, Mg 3 Ca₃(PO₄)₄: Eu²⁺, (Ca, Sr, Ba)₅(PO₄)₃CI: Eu²⁺,

Ca.₂B₅O₉(Br, CI): Eu²⁺, BaMgAlioOi7: Eu²⁺, Mn²⁺, BaMg2AI₁₆O₂₇: Eu²⁺, (Lu, Gd)₂SiO₅: Ce³⁺, Sr2P2O7: Sn²⁺, SrSiAI2O₃N₂: Ce³⁺ or La₃Si₆Nn: Ce³⁺. By mixing the blue and orange spectral components in a radiation flux ratio of about 1:15, one obtains a spectrum corresponding to the color of the black body radiation, which is perceived by a person as low SST white or flame light.

The phosphor conversion lamp (100, 200) has a conventional construction of a semiconductor chip (1,11) consisting of a p-type layer connected to the anode terminals and an n-type layer connected to the cathode terminals (3, 13) which envelop the active layer. In the active layer, electrons injected from a n-type envelope recombine with holes injected from a p-type envelope.

The semiconductor chip (1, 11) of the exposed phosphor conversion LEDs (100, 200) has an active layer that emits blue or near UV light. In the active layer, it is preferable to use the third group of nitride compounds having the general formula Al_yln_xGai-_x-_yN. These materials have a high chemical and photochemical inertness, which determines the durability of LEDs. The structure of these semiconductor energy bands (remote side valleys) and the characteristics of charge recombination result in a weak temperature dependence of the output stream. The thickness of the active layer and the molar portions of the indium and / or aluminum, x and y, respectively, are selected such that the peak of the emission band is at the desired wavelength.

The most suitable active layer material of a revealing phosphor of a partial conversion phosphor (100) in which a semiconductor chip (1) emits in the 400-500 nm wavelength range is triple ln_xGai-_xN alloy.

The active layer of the revealing full phosphor conversion LED (200), in which the semiconductor chip (11) radiates at a wavelength of less than 450 nm, can be made of triple ln_xGai-_xN alloy (wavelength range 370-450 nm), binary GaN compound (wavelength about 360 nm), or triple Al_yGai-_yN alloy (wavelengths shorter than 360 nm). Also, a quadruple Al can be used throughout the wavelength range_yln_xGai-_x-_yN alloy.

Typically, the chip (1, 11) of the luminaires (100, 200) is mounted in a reflector cup (2, 12) and the wires (4, 14) are connected to the metal terminals (3, 13) through which the chip (1, 11) is powered by a current. The wavelength transducer (5,15), which is a resin or silicone layer, a crystalline or ceramic plate, or a plastic mold containing phosphor particles, is arranged adjacent to said semiconductor chip (1, 11) so that a portion or all of the photon flux generated in the semiconductor is on the chip, the phosphor particles would be absorbed. The transducer (5, 15) may also be located outside the luminaire body, for example, the transducer functions may be performed by a transparent luminaire cover covered with phosphor particles.

The wavelength transducer (5, 15) is configured such that the wavelengths and radiation fluxes of the components of the spectral radiation of the LEDs are best suited for photobiologically friendly field illumination with low non-visual circadian effects. The optimum spectrum composition may vary according to specific applications (lighting of streets, parking lots, pedestrian and bicycle paths, building facades, monuments, parks, parking lots, and courtyards) and luminance requirements.

The moderately optimal composition of the two-color, black-body radiant light with low non-circular circadian effect is such that the spectral power distribution consists of about 94-95% of orange light and about 5-6% of blue light at SST = 2000 K and about 75%. -80% orange light and about 20-25% blue light at SST = 3000K. Therefore, it is proposed that the ratio of the beam fluxes of the wide application conversion phosphor lamps with blue and orange spectral components to the following proportions, ie for phosphor partial conversion would be no more than 1:17 respectively, and for phosphor full conversion would be no more than 1:15 respectively at SST = 2000 K and would not be more than 1: 5 for phosphor partial conversion respectively. , and for phosphor complete conversion would be no more than 1: 4 for SST = 3000 K, respectively.

In two spectral component luminaires for photobiologically friendly outdoor illumination, the radiation fluxes of each spectral component can be determined in several ways. In the proposed luminaires, this is done by selecting the size and concentration of phosphor particles, the wavelength transducer thickness, the refractive index of the wavelength transducer material, the distance between the wavelength transducer and the electroluminescent structure, and the position of the wavelength transducer inside or outside the luminaire housing.

Optimal photobiologically friendly street lighting can be achieved when the color of the lights corresponds to the color of the black body radiation. The spectral components are chosen considering the mesopic functions of spectral luminous efficiency and spectral circadian efficiency. With a small non-circular circular effect, the optimum spectral components peak at about 450 nm and 585 nm. As the aforementioned spectral performance functions are widespread, the optimal wavelength values ​​indicated may vary within ± 15 nm.

Specific examples

As an example, a partial blue light conversion lamp (100) is provided for photobiologically friendly outdoor illumination. The illuminator contains a semiconductor chip (1) which generates blue light by injection electroluminescence. The chip is inserted into the reflector cup (2) and connected to the terminals (3) using the connected wires (4). The chip is covered by a wavelength converter (5). The chip and transducer are encapsulated in a transparent housing (6) such as a plastic or silicone die. Typically, a semiconductor chip is composed of a p-type layer connected to the anode terminals and an n-type layer connected to the cathode terminals which envelop the active layer. In the active layer, electrons injected from a n-type shell layer radially recombine with holes injected from a p-type shell layer. A typical active layer material is triple ln_xGai-_xThe N alloy, where the thickness of the active layer and the molar fraction of the indium in the alloy x are selected such that the emission band has a peak at 430-470 nm.

The light generated in the semiconductor chip (1) passes through a wavelength converter (5) containing phosphor particles (7). In one case, photons emitted from a semiconductor chip (8) are not absorbed by the phosphor particles and escape from the chip to the environment through a transparent housing. Alternatively, photons (9) emitted from a semiconductor chip are absorbed by phosphor particles (7) and converted to photons (10) having a wavelength corresponding to a spectral component with a peak in the 570-600 nm (orange) spectrum. Such a light emits a two-component blue-orange (low SST white or flame-colored) light.

An example of a complete near-UV conversion of phosphor in a phosphor (200) is provided as an example for photobiologically friendly outdoor lighting. Said luminaire (200) comprises a semiconductor chip (11) which generates dipped UV light by injection electroluminescence. The chip (11) is inserted into the reflector cup (12) and is connected to the terminals (13) by means of connected wires (14). The chip is covered by a wavelength converter (15). Said chip (14) and said transducer (15) are encapsulated in a transparent housing (16). Typically, a semiconductor chip is composed of a p-type layer connected to the anode terminals and an n-type layer connected to the cathode terminals which envelop the active layer. In the active layer, electrons injected from a n-type shell layer radially recombine with holes injected from a p-type shell layer. Typical active layer material is either a GaN semiconductor compound or a triple ln_xGai-_xN or AlyGai-_yN alloy, or quadruple ln_xAl_yGa-i-_x-YN alloy, whereby the thickness of the active layer and the mole fraction of the indium x or the aluminum part of the alloy y are chosen such that the emission band has a peak at wavelengths shorter than 450 nm.

The light generated in the semiconductor chip (11) passes through a wavelength transducer (15) containing the first type of phosphor particles (17) and additionally the second type of phosphor particles (18). All photons emitted from a semiconductor chip are absorbed by phosphor particles. In this case, a portion of the photons (19) is absorbed by the first type of phosphor particles (17) and converted to photons (20) having a wavelength corresponding to a spectral component with a peak in the 570-600 nm (orange) spectrum. Also, the remainder of the photons (21) are absorbed by the second type of phosphor particles (18) and converted to photons (22) having a wavelength in the 430-470 nm (blue) spectrum. Such a two-color light emits blue-orange (low SST white or flame-colored) light.

As an example illustrating the invention (Fig. 4), available electroluminescence spectra of semiconductor chips, which are proposed for use in conversion phosphor luminaires for photobiologically friendly field illumination, are provided. For both partial and total conversion, the electroluminescence spectra of the LEDs must be consistent with the absorption spectra of the phosphorus. In addition, at partial conversion, the electroluminescence spectrum of the luminaire must be matched with orange phosphorus so that the total spectral power distribution corresponds to the absolute color of the black body radiation.

Accordingly, Figure 4 (a) shows the electroluminescence spectrum corresponding to a semiconductor chip having an active layer made of a triple ln_xGai-_xN alloy, where the thickness of the active layer and the molar fraction of the indium in the alloy are selected such that the peak of the emission band is at 445 nm in the blue spectrum. Such a chip can be used in a partial conversion luminaire for photobiologically friendly outdoor lighting. Accordingly, Figure 4 (b) shows the electroluminescence spectrum corresponding to a semiconductor chip having an active layer made of a triple ln_xGai-_xN alloy, where the thickness of the active layer and the molar fraction of the indium in the alloy are chosen such that the peak of the irradiance is at 380 nm in the near UV spectrum. Such a chip can be used in a full conversion LED for photobiologically friendly outdoor lighting.

As an example illustrating the invention (Fig. 5), individual photoluminescence spectra corresponding to phosphores are proposed for use in conversion phosphor lamps for photobiologically friendly outdoor lighting. Accordingly, Figure 5 (a) shows the photoluminescence spectra corresponding to yttrium magnesium aluminum silicate garnet activated with trivalent cerium ions (Y3Mg2AISi2O12.Ce³⁴·), Barium strontium silicon nitride activated with divalent europium ions ((Ba, Sr) 2Si5N8: Eu²⁺), barium strontium orthosilicate activated by divalent europium ions ((Ba, Sr) SiO4: Eu²⁺), calcium - alpha silicon aluminum oxynitride activated by divalent europium ions (Ca-a-SiAION: Eu²⁺) or calcium strontium selenide activated by divalent europium ions ((Ca, Sr) Se: Eu²⁺) phosphorus, which absorbs blue or dim UV light and emits orange light with a spectral band at 570-600 nm. Such phosphores can be used in partial or full conversion luminaires for photobiologically friendly outdoor lighting to generate an orange component of the spectrum. Accordingly, Figure 5 (b) shows the photoluminescence spectrum corresponding to the aluminum phosphorus activated by divalent europium ions (BaMgAlioOi7: Eu).²⁺), which absorbs near-UV light and emits blue light with a spectral band at 446 nm. Such phosphor can be used in full conversion luminaires for photobiologically friendly outdoor lighting to generate a blue spectral component.

An illustrative example of the invention (Fig. 6) is provided by SGS of partial and full conversion luminaires for photobiologically friendly outdoor lighting. The spectra have a blue component with a peak in the 430-470 nm range, generated by an InGaN semiconductor chip due to injection electroluminescence or generated by a wavelength converter due to photoluminescence, and an orange component generated by a wavelength converter by photoluminescence. The radiation fluxes corresponding to the residual blue light and the light generated by each phosphor are determined by selecting the concentration of the phosphor particles, the wavelength transducer thickness, the refractive index of the wavelength transducer, and the position of the wavelength transducer inside or outside the housing. Accordingly, Figure 6 (a) shows the SGS corresponding to the flame-colored bicomponent light generated by the partial conversion of a blue light with a spectral component peak at 445-450 nm in an orange light emitting Y₃Mg 2 Al₂0i2: Ce³⁺, (Ba, Sr) 2Si5N8: Eu²⁺, (Ba, Sr) 2SiC> 4: Eu²⁺, Ca-a-SiAION: Eu²⁺ and (Ca, Sr) Se: Eu²⁺ in phosphorus whose spectral component has a peak at 570-600 nm due to photoluminescence. Accordingly, Figure 6 (b) shows the SGS corresponding to the two-component flame color light generated by the full conversion of the near-UV light BaMgAI10O17: Eu²⁺ and Y3Mg₂AISi₂0i₂: Ce³⁺ in the case of phosphorus, which emits blue light with a spectral component peak at 446 nm and an orange light with a spectral component peak at 600 nm respectively, due to photoluminescence.

Such flame light fixtures can be used for evening illumination of streets, pedestrian and bicycle paths, courtyards, buildings, monuments, parks, parking lots, and home yards, so as not to disturb the human circadian rhythm.

Table 1 shows the photometric, color and photobiological parameters of the sample luminaires.

Table 1

<td>The light source.</td><td>SST, K</td><td>CPF, blm / lm 0.3 cd / m²</td><td>CPF, blm / lm 2 cd / m²</td><td>CPF norm. to CIE A 2 cd / m²</td><td>NW, lm / W 0.3 cd / m²</td><td>st, lm / W 2 cd / m²</td><td>SARmes 0.3 cd / m²</td><td>SARmes 2 cd / m²</td><td>SARfot</td><td>η</td>

<td>lnGaN / (Ba, Sr) 2Si₅N₈</td><td> 1704</td><td> 0,075</td><td> 0,068</td><td> 0,185</td><td> 298</td><td> 329</td><td> 84</td><td> 69</td><td> 39</td><td> 0,73</td>

<td>InGaN / Y3Mg2AlSi20i2</td><td> 2088</td><td> 0,146</td><td> 0,139</td><td> 0,379</td><td> 250</td><td> 263</td><td> 90</td><td> 81</td><td> 62</td><td> 0,71</td>

<td>InGaN / (Ca, Sr) Se</td><td> 2101</td><td> 0,124</td><td> 0,114</td><td> 0,311</td><td> 404</td><td> 439</td><td> 78</td><td> 57</td><td> 16</td><td> 0,77</td>

<td>InGaN / Ca-a-SiAION</td><td> 2426</td><td> 0,193</td><td> 0,186</td><td> 0,507</td><td> 356</td><td> 369</td><td> 88</td><td> 76</td><td> 53</td><td> 0,76</td>

<td>InGaN / (Ba, Sr)₂SiO4</td><td> 2542</td><td> 0,214</td><td> 0,208</td><td> 0,567</td><td> 343</td><td> 353</td><td> 88</td><td> 77</td><td> 55</td><td> 0,75</td>

<td>Warm white LED light</td><td> 3652</td><td> 0,301</td><td> 0,311</td><td> 0,847</td><td> 377</td><td> 365</td><td> 90</td><td> 80</td><td> 62</td><td> 0,77</td>

<td>Cold white LED light</td><td> 5000</td><td> 0,472</td><td> 0,515</td><td> 1,403</td><td> 394</td><td> 361</td><td> 91</td><td> 82</td><td> 65</td><td> 0,82</td>

<td>HPS lamp</td><td> 1886</td><td> 0,126</td><td> 0,117</td><td> 0,319</td><td> 319</td><td> 344</td><td> 77</td><td> 55</td><td> 12</td><td> -</td>

<td>CIE A standard lightening</td><td> 2856</td><td> 0,345</td><td> 0,367</td><td> 1</td><td> 170</td><td> 160</td><td> 100</td><td> 100</td><td> 100</td><td> -</td>

The parameters in Table 1 are compared with those of commercial warm and cold white LEDs and CIE standard luminaire A: SST - associated color temperature, CPF - circadian effect factor, SV - luminous efficiency, SAR

- the general color rendering index, SAR_mes is the mesopic index of color and η

- the limiting efficiency determined by the difference in wavelengths of the light emitted by the semiconductor chip and the phosphor (Stokes offset).

The parameters of the luminaires in Table 1 are compared with those of the widely used HPS (h / gh pressure sodium) lamp. The values ​​are given with an ambient luminance of 0.3 and 2 cd / m² (standard for low-end ME6 and high-end ME1 street lighting respectively). The third column of CPF gives the values ​​normalized to CIE standard luminous A (2856 K black body radiation), assuming an ambient luminance of 2 cd / m².

Table 1 shows that the parameters of light sources are strongly dependent on the phosphorus chosen, but the general trend is that with higher SST values ​​the circadian effect factor of the source increases. The SGS of the offered luminaires goes down to the luminous efficacy values ​​of commercial luminaires and HPS lamps, but most of them have a lower circadian effect factor: at 2cd / m²the luminance of the luminaires offered for ambient luminosity is approximately 0.1-0.25 blm / lm lower than the CPF for commercial warm white luminaires, and even 0.3-0.45 blm / lm lower than the CPF for commercial luminaries. Compared to CIE standard luminaire A, the CPF of the proposed luminaires, rated to CIE standard luminaire A CPF, is not more than 0.6. Meanwhile, for warm white light, this standardized CPF is about 0.85, and for cold white light, which corresponds to the main prototype of this patent, about 1.4.

The luminaires offered have a color-rendering capability comparable to that of commercial luminaires and are significantly better than HPS lamps. The marginal efficiency values ​​for commercial warm white and offered luminaires are very similar, but due to the lower Stokes shift, commercial cold white luminaires have higher marginal performance.

the shortwave and longwave components of the light spectrum produced by the proposed partial conversion phosphor lamps have the following partial beam flux ratios, respectively:

-About 1:21 when using Y3Mg₂AISi20i2: Ce³⁺ phosphorus, the wavelength of the InGaN chip emitted has a peak wavelength of 440 nm and the resulting SGS SST = 2088 K, with CIE A standard luminance-normalized CPF = 0.379 at 2 cd / m² environmental luminosity;

-About 1:37 when using (Ba, Sr)₂Si5N₈: Eu²⁺ phosphorus, the InGaN chip emitted a wavelength peak at 443 nm and the resulting SGS SST = 1704 K, with CIE A standard luminance-normalized CPF = 0.185 at 2 cd / m²environmental luminosity;

-about 1:10 when (Ba, Sr) 2SiO is used₄: Eu²⁺ phosphorus, the wavelength of the InGaN chip's emission spectrum at 440 nm, and the resulting SGS SST = 2542 K, and the CIE A standard luminance is CPF = 0.567 at 2 cd / m²environmental luminosity;

-about 1:14 when using (Ca, Sr) Se: Eu²⁺ phosphorus, the peak wavelength of the InGaN chip at 443 nm, and the resulting SGS SST = 2101 K, and the CIE A standard luminance is CPF = 0.311 at 2 cd / m²environmental luminosity;

-about 1:11 when using Ca-a-SiAION: Eu²⁺ phosphorus, the peak wavelength of the InGaN chip at 443 nm and the resulting SGS SST = 2426 K, and the CIE A standard luminance is CPF = 0.507 at 2 cd / m²for environmental luminosity.

The shortwave and longwave components of the proposed luminescent spectrum of the proposed total conversion phosphor LEDs have the following partial beam flux ratios, respectively:

-About 1:19 when using Y₃Mg₂AISi20i2: Ce³⁺ phosphorus, SGS SST = 2100 K, CIE A standard luminous flux normalized CPF = 0.398 at 2 cd / m²environmental luminosity;

-About 1:33 when using (Ba, Sr)₂Si5N₈: Eu²⁺ phosphorus, obtained by SGS SST = 1708 K and CPF = 0.196 at CIE A standard beam at 2 cd / m²environmental luminosity;

-About 1: 9 when used (Ba, Sr)₂SiO4: Eu²⁺ phosphorus, obtained SGS SST = 2576 K and CPF = 0.613 at CIE A standard light at 2 cd / m²environmental luminosity;

-about 1:12 when using (Ca, Sr) Se: Eu²⁺ phosphorus, obtained by SGS of SST = 2114 K and CPF = 0.338 at CIE A standard beam at 2 cd / m²environmental luminosity;

-about 1:10 when Ca-a-SiAION is used: Eu²⁺ phosphorus obtained by SGS SST = 2449 K, with CIE A standard luminous flux standardized CPF = 0.545 at 2 cd / m²for environmental luminosity.