RU2476765C2 - Lighting device and method to generate light mixture with this device - Google Patents

Abstract

FIELD: electrical engineering.

SUBSTANCE: lighting device consists of the first, second and third groups of solid-state light sources (hereinafter - "SSLSs") that irradiate light with dominant wavelengths within the ranges of 430…480 nm, 480…520 nm and 600…650 nm and at least one luminophor that irradiates light with dominant wavelengths within the range from 530 to 585 nm. When the device is connected to a power supply, the combination of light irradiated by the first SSLSs group and light emitted by the first luminophors group, yields (in case there are no outside light sources) a colour mixture having colour coordinates (x; y) in the colour chart 1931 CIE within the area limited by the coordinate points (0.32; 0.30), (0.315; 0.35), (0.367; 0.4), (0.44; 0.43), (0.41; 0.367), (0.357; 0.33) and the lines connecting them. The second and third SSLSs groups considerably improve the lighting device colour rendering.

EFFECT: improvement of the lighting device operational qualities.

11 cl, 43 dwg

Description

The present invention relates to electrical engineering and relates to the design of a lighting device, in particular a device that includes one or more solid-state light sources (hereinafter - TIS) of the type, for example, one or more LEDs (hereinafter - LED) and one or more luminescent materials ( for example, one or more phosphors). The present invention also contemplates a lighting method using LED components and luminescent materials.

CIE color chart (Commission International d'Eclairage - International Commission on Lighting) is a chart showing the color perceived by the human eye depending on two parameters x and y (for chart 1931) (figure 1) or u 'and v' (for chart 1976) (Fig. 2). A technical description of CIE color diagrams (see, for example, Encyclopedia of Physical Science and Technology, Volume 7, pp. 230-231 (Robert A. Meyers, 1987 edition)), also described in detail in US Pat. No. 7,213,940, F21V 9/00, publ. 05/08/2007. The colors of the spectrum are distributed near the edge of the circled space, which includes all the shades perceived by the human eye. The boundary line represents the maximum color saturation of the spectrum. As indicated above, the 1976 CIE chart is similar to the 1931 CIE except that the 1976 CIE has been changed so that equal distances in the 1976 CIE correspond to the same difference in color perception. In general, the 1931 CIE color charts (an international standard for primary colors, created in 1931) and CIE 1976 (similar to the 1931 chart, but modified so that similar perceived color differences correspond to the same distances) provide a useful basis for determining any colors as a weighted sum of other colors.

In the 1931 CIE diagram, the deviation from a point in the diagram can be expressed either in the form of coordinates or, in another way, to give a spatial representation of the perceived color difference, in the form of so-called Macadam ellipses. For example, a point region defined as being located at 10 MacAdam ellipses from a given tone in the 1931 CIE diagram consists of tones, each of which is perceived to have the same degree of difference with the given tone (the same can be said for the set of points, which are located from a given tone to another number of MacAdam ellipses).

Since the same distances in the CIE diagram 1976 represent the same differences in perceived color, a deviation from a point in the CIE diagram 1976 can be expressed by the coordinates Δu 'and Δv'; for example, the distance from the point Δ (u ';v') = (Δu ' ² + Δv' ² ) ^1/2 , and the shades that make up the set of points located at the same distance from the given hue are perceived as different from the given hue in one and the same degree. In other words, the MacAdam ellipses on the 1976 CIE diagram become circles.

CIE color coordinates and color charts are discussed in detail in many books and other publications, such as pp. 98-107 of N.K. Butler’s book “Phosphor Fluorescent Lamps” (Pennsylvania State University Press, 1980), “Fluorescent Materials” (Springer- Ferlag, 1994) listed in the list of sources.

Color coordinates (i.e. color points) that lie along the line of the black body (Fig. 1) are described by the Planck equation: E (λ) = Аλ-5 / (е (В / Т) -1), where Е - radiation intensity, λ is the emitted wavelength, T is the color temperature of the black body, A and B are constants. The color coordinates lying on or near the line of the black body represent a white light that is pleasant for a human observer. The 1976 CIE diagram includes temperature lists along the black body region. These temperature lists show the color path of blackbody radiation that has been heated to these temperatures. As it warms up, the object begins to heat up, first it glows reddish, then yellowish, then white and finally bluish. This is due to the fact that the wavelength associated with the peak radiation of the blackbody emitter gradually becomes shorter with increasing temperature in accordance with the Wien's law of displacement. Sources emitting light located on or close to the line of a completely black body can thus be described by their color temperature.

CRI is a relative indicator of how much color reproduction of a lighting system is comparable to blackbody radiation. CRI is equal to 100 if the color coordinates of the set of test colors illuminated by the lighting system completely coincide with the color coordinates of the same set of colors illuminated by the radiator in the form of a completely black body.

The expression "Saturated TIS" is a generally accepted concept that is understood by specialists in this field. Means a light source with a purity of at least 85%. The concept of purity of light, as well as methods for calculating this value are also well known to specialists in this field.

The expression "TIS range 430-480 nm" means any TIS that when turned on will emit light having a dominant wavelength in the range from about 430 to about 480 nm.

The expression “TIS range of 480-520 nm” means any TIS that when turned on will emit light having a dominant wavelength in the range of from about 480 to about 520 nm.

The expression "TIS range 600-650 nm" means any TIS, which when turned on will emit light having a dominant wavelength in the range from about 600 to about 650 nm.

The expression “phosphor in the range 530-585 nm” means any phosphor that when excited will emit light having a dominant wavelength in the range from about 530 to about 585 nm.

The term “current”, as it is used in the expression “if you feed the first power line with current”, “apply power to the first line”, etc., means an electric current sufficient to provide radiation by the TIS (s) the range of 430-480 nm of light having a dominant wavelength in the range of from about 430 to about 480 nm, the emission TIS'om (s) of the range of 480-520 nm of light having a dominant wavelength in the range of from about 480 to about 520 nm, and / or emission by TIS'om (s) of the range 600-650 nm of light having a dominant wavelength in the range from rimerno 600 to about 650 nm.

The expression “directly or electrically connected with the possibility of disconnection” means “directly electrically connected” or “electrically connected with the possibility of disconnection”.

The expression given in this document that one or more TISs are “electrically connected” to the power line means that current can flow to the TIS (s) when it is supplied to the power line.

The expression given in this document that one (or more) switches are electrically connected to the power line means that current can flow through the power line if the switch (s) is closed (s), and that current flow through the power line is prevented if the switch (switches) open (s).

The expression given in this document that one component of the device “can selectively turn on and off the current” means that there is a switch between the two components that can open and close, and if the switch is closed, then these two components are electrically connected, and if the switch is open (i.e. during any period of time in which the switch is open), the two components are not electrically connected.

The expression “included”, as used herein in relation to TIS, means that at least some current is supplied to the TIS, leading to the emission of at least some light by it.

The expression “excited”, as used herein with reference to phosphors, means that at least some electromagnetic radiation (for example, visible light, ultraviolet or infrared radiation), in contact with the phosphor, leads to the emission of at least some light. TIS used in the devices described in the present invention, and the phosphor (or phosphors) used in the devices described in the present invention can have any of the known structures.

A wide range of such TIS and phosphors is readily available and well known, and all of them can be applied. Examples of the design and use of TIS (LEDs) and phosphors suitable for the practical implementation of this invention are described in US patent No. 7,213,940 and its accompanying materials.

Compared to normal TIS lifetimes, incandescent lamps have a relatively short lifespan, typically around 750-1000 hours. For comparison, the lifetime of LEDs, for example, can generally be measured for decades. Fluorescent lamps have a longer life (for example, 10000-20000 hours) than incandescent lamps, but give less favorable color reproduction.

Color reproduction is typically measured using the Color Rendering Index (CRI). CRI is a relative assessment of how the color reproduction of a lighting system is comparable to the color reproduction of a completely black body, i.e. it is a measure of the relative color shift of the surface of an object illuminated by a measured lamp. CRI is 100 if the color coordinates of a set of test colors when illuminated by a lighting system (lamp) are the same as the coordinates of the same colors when illuminated by absolutely black body radiation. Daylight (of the sun) has the highest CRI (100), incandescent (ordinary) lamps are also quite close (about 95), and fluorescent lighting is less accurate (70-85). Some types of specialized lighting have relatively low CRIs (for example, mercury vapor lamps, sodium lamps — CRIs as low as 40 or even less). Sodium lights are used, for example, to illuminate roads. The driver’s reaction time, however, significantly decreases with lower CRI values (for any given illumination, object recognition worsens with a decrease in CRI).

For these and other reasons, efforts are continuing to develop ways in which TIS can be used in place of incandescent, fluorescent and other light-emitting devices in a wide range of applications. In addition, where TISs are already in use, steps are being taken to improve TIS parameters, for example, with respect to energy efficiency, color rendering coefficient (CRI), contrast, efficiency (lumen / watt) and / or service life.

LEDs (hereinafter referred to as LEDs) are semiconductor devices that emit light (ultraviolet, visible, and IR) when a potential difference is applied to the pn structure. There are several known methods for manufacturing LEDs and related structures; any such devices may be used for the present invention. For example, chapters 12-14 of the textbook on Physics of Semiconductor Devices S.M. Ze [Physics of semiconductor devices by SMSze, 2-nd edition, 1981] and chapter 7 of the Textbook of Modern Physics of Semiconductor Devices (1998) [Modem Semiconductor Device Physics by SMSze, 1998] describe various types of light emitting devices, including LEDs. The generally recognized and commercially available LEDs sold in electronics stores are typically a “packaged” device consisting of several parts. These devices in the housing typically include a semiconductor light emitting diode, such (but not limited to) as described in US Nos. 04918487, 5631190 and 5912477, as well as various connectors, wires and the housing in which the LED is packaged.

An LED emits light as a result of the excitation of electrons passing through the band gap between the conductor and the valence band of the semiconductor active (light emitting) layer. The transition of an electron forms light at a wavelength depending on the band gap. Thus, the color of the light (wavelength) emitted by the LED depends on the semiconductor materials of the active layers of the LED. But some characteristics of TIS present problems, some of which have not yet been completely eliminated. For example, the emission spectrum of a given LED, as a rule, is concentrated around one wavelength (which is dictated by the design of the LED and its structure), which is desirable for some applications and undesirable for others (for example, when used as light sources, such a radiation spectrum gives very low CRI).

This is due to the fact that light that is perceived as white is nothing but a mandatory combination of radiation of two or more colors (or wavelengths), therefore, no LED alone can give white light. White LEDs were made in which the LED pixel is formed from the corresponding red, green, and blue LEDs. There are other “white” LEDs that include an LED that emits blue light and luminescent material (such as phosphorus) that emits yellow light in response to excitation by the light emitted from the LED. When blue light and yellow light mix, a light is produced that is perceived as white.

A wide range of luminescent materials (and structures that contain luminescent materials known as phosphors or phosphor carriers, for example, as described in US patent No. 6600175) is well known and available to professionals in this field. For example, phosphorus is a luminescent material that emits secondary rays (for example, visible light) when illuminated by a source of exciting radiation. In many cases, the secondary radiation at a wavelength different from the wavelength of the exciting radiation. Other examples include fluorescent reflector materials, reflective tapes and inks that glow in the visible region of the spectrum when exposed to ultraviolet light.

Luminescent materials can be classified as lowering, that is, materials that convert “incident” photons into photons with lower level energy (long-wavelength) or increasing, i.e. materials that convert photons into photons of a higher energy level (shortwave).

The incorporation of luminescent materials into LED devices was achieved by adding luminescent materials to the transparent plastic of the filler material (for example, based on epoxy resin or silicone-based material), as indicated above, for example, by mixing with the filler and by coating.

For example, US patent No. 6963166 says that a conventional LED lamp includes an LED crystal, a substrate, a dome-shaped transparent housing for protecting the LED, a conductor for supplying power to the LED, and a reflector cup for reflecting the LED radiation in the desired direction in which the LED crystal is coated with the first resin layer , which on top is additionally coated with the second part of the resin. In accordance with this patent, the first part of the coating with resin is obtained by filling the reflector bowl and curing it, after the LED crystal was installed at the bottom of the reflector cup, and its cathode and anode were electrically connected to the legs of the LED. According to US Pat. No. 6,963,166, phosphorus is added to the first part of the resin so that when excited by the light A that emits the LED crystal, it itself begins to emit light ("light B"), which has a longer wavelength than light A; part of light A penetrates through the first part of the mixture of resin and phosphorus, and, as a consequence, light C, as a mixture of light A and light B, can be used for lighting.

As noted above, “white light emitting diodes” (that is, of a color that is perceived as white or almost white) have been investigated as potential substitutes for white incandescent lamps. A representative example of a white LED consists of a blue LED whose crystal is made of gallium nitride (GaN) coated with a phosphor such as YAG. In such an LED, a blue LED chip produces blue radiation, and yellow phosphorus produces fluorescence from exposure to this radiation. Further, in some designs, white LEDs are made by forming a ceramic phosphor layer on an output surface of a blue light emitting semiconductor LED. Part of the blue light coming from the LED crystal passes through the phosphor, and part of the blue light coming from the LED crystal is absorbed by the phosphor, which is excited and emits yellow light. Part of the blue light emitted by the LED that passes through the phosphor is mixed with the yellow light emitted by the phosphor. The observer perceives the mixture of blue and yellow light as white light.

As noted above, in another type of lighting LED, an LED crystal that emits ultraviolet light is combined with phosphorous materials that give red (R), green (G) and blue (B) light rays. In such "RGB LEDs", the ultraviolet light emitted by the crystal excites the phosphor, and the phosphor begins to emit red, green and blue light, which when mixed with the human eye is seen as white light. Therefore, white light can also be obtained as a mixture of these colors.

Today, there is a need for a highly efficient white light source that combines the efficiency and long life of white LEDs (avoiding the use of relatively inefficient light sources) with an acceptable color temperature, good color reproduction and a wide range.

In the decision of US No. 7213940, F21V 9/00, publ. 2007-05-08 (this decision was made as a prototype for the claimed objects), a lighting device is described, characterized in that it contains one or more TIS emitting light with a dominant wavelength in the range from 430 nm to 480 nm, exciting one or more phosphors that emit light with a dominant wavelength in the range from 555 to 585 nm, and one or more TIS emitting light with a dominant wavelength in the range from 600 nm to 630 nm in such a way that the combination of light that was emitted by the first group of TIS, first group of phosphors and second I am a group of TIS, produces a mixture of light with (x; y) coordinate on the 1931 CIE color chart, which defines a point that is within 10 MacAdam ellipses from at least one point on the emission line of a completely black body in the color chart The 1931 CIE, and combinations of the light emitted by the first group of TIS and the first group of phosphors in the absence of any additional light, produce a sub-mixture of light with (x; y) the color coordinates that fall into the first region on the CIE color chart, covered by the first, second, third, fourth and fifth line segments, the first line segment connecting the first and second points, the second line segment connecting the second and third points, the third segment connecting the third and fourth points, the fourth segment connecting the fourth and fifth points, and the fifth segment of the line connecting the fifth and first points, the first point with (x; y) coordinates of 0.32; 0.40, the second point with (x; y) coordinates 0.36; 0.48, the third point with (x; y) coordinates of 0.43; 0.45, the fourth point with (x; y) coordinates of 0.42; 0.42 and the fifth point with (x; y) coordinates 0.36, 0.38.

The expression "dominant wavelength" is used here in accordance with its well-known and recognized meaning, denoting the perceived color of the spectrum, i.e. light of a single wavelength, which gives a sensation of a color that is most similar to the color perceived from viewing in the light that a given light source emits (i.e., approximately similar to a “color”), as opposed to simply a “wavelength” which, as is well known, refers in the spectral line to the greatest power of the light source. Since the human eye does not see at all wavelengths equally (it perceives yellow and green light better than red and blue) and because the light from many TISs (for example, LEDs) is actually a set of radiation of different wavelengths, then perceived the color (i.e. the color of the dominant wavelength) is not necessarily equal (and often different) from the point with the highest power (i.e. just the wavelength or peak wavelength). But really monochromatic light sources, such as a laser, have the same dominant and peak wavelengths.

Thus, US Pat. No. 7,213,940 suggests the use of “white” TISs (light emitting diodes), in which the amount of phosphor giving light in the red part of the spectrum, which (instead) is emitted by separately added light emitting diodes with a dominant wavelength of 600 ... 630 nm, is reduced. At the same time, “white” LEDs cease to be even conditionally “white”, but become green-yellow (see the coordinates of the pentagon from the description of this patent) and, as a result, are non-standard.

Usually, the lamp designer is faced with the task of making a lamp with a high CRI coefficient (another name is the color rendering index Ra) and the position of the color point of the lamp strictly on the line of an absolutely black body.

Color reproduction index (color reproduction coefficient) is a parameter characterizing the level of correspondence of the natural color of a body to the visible (apparent) color of this body when it is illuminated by this light source.

The present invention is aimed at achieving a technical result, which consists in improving the performance of a lighting device built on the basis of LEDs and phosphor material by increasing the color rendering index (CRI).

The specified technical result in terms of the device is achieved by the fact that the lighting device, characterized in that it contains a first solid-state light source, a second solid-state light source, a third solid-state light source, a phosphor or a group of phosphors, at least one power line to which are electrically connected the first, second and third solid-state light sources, the first mentioned solid-state light source is configured to emit light with a dominant wavelength in the range from 430 nm d 480 nm, the second mentioned solid state light source is configured to emit light with a dominant wavelength in the range of 600 nm to 650 nm, the third said solid state light source is configured to emit light with a dominant wavelength in the range from 480 nm to 520 nm, and said phosphor or said group of phosphors, when excited, is configured to emit light with a dominant wavelength in the range from 530 to 585 nm, and when a power is supplied via said power line, a combination of light ory rejected, in the absence of other light sources of first, second and third mentioned solid state light sources and said phosphor or group of phosphors to form a mixture of light with the coordinate (x; y) points on the 1931 CIE chromaticity diagram located within 10 MacAdam ellipses of at least one point on the emission line of a completely black body on the 1931 CIE chromaticity diagram, with the combination of light emitted by the first solid-state light source mentioned and said phosphor or a group of phosphors in the absence of other light sources produces a sub-mixture of light with coordinates on the 1931 CIE color chart, which fall into the first region on this chart, covered by the first, second, third, fourth, fifth and sixth line segments, the first of which connects the first point with coordinates (0.32; 0.30) and the second point with coordinates (0.315; 0.35), the second - the second and third point with coordinates (0.367; 0.4), the third is the third and fourth point with coordinates (0.44; 0.43), the fourth is the fourth and fifth point with coordinates (0.41; 0.367), the fifth is the fifth and sixth point with coordinates (0.357; 0.33) and sixth - the sixth and first point.

Moreover, said first solid-state light source is made in the form of one LED or more than one LED, said second solid-state light source is made in the form of one LED or more than one LED, said third solid-state light source is made in the form of one LED or more than one LED, and said first phosphor or all of said first group of phosphors is configured to emit light under the influence of light from said first solid state source and light when you turn it on.

The specified technical result in terms of the method is achieved by the fact that the method of forming a mixture of light, characterized by the coordinate of a point on the 1931 CIE color chart, located within 10 MacAdam ellipses from at least one point on the emission line of a completely black body in this diagram, consists in supplying power simultaneously to the first solid-state light source in the form of at least one LED for emitting light with a dominant wavelength in the range from 430 nm to 480 nm, to the second solid-state source with eta in the form of at least one LED for emitting light with a dominant wavelength in the range of 600 nm to 650 nm, to a third solid state light source in the form of at least one LED for emitting light with a dominant wavelength in the range of 480 nm to 520 nm, and excitation by light emitted by the first solid-state light source of at least one phosphor, with the emission of light with a dominant wavelength in the range from 530 to 585 nm to form together with the light the radiation of the first solid-state light source a sub-mixture of light with coordinates on the 1931 CIE color chart, which fall into the first region on this chart, covered by the first, second, third, fourth, fifth and sixth line segments, the first of which connects the first point with the coordinates (0.32; 0.30) and the second point with coordinates (0.315; 0.35), the second - the second and third point with coordinates (0.367; 0.4), the third - the third and fourth point with coordinates (0.44; 0.43) , the fourth is the fourth and fifth point with coordinates (0.41; 0.367), the fifth is the fifth and sixth point with coordinates (0.357; 0.33) and the sixth is the sixth and first point.

These features are significant and are interconnected with the formation of a stable set of essential features sufficient to obtain the desired technical result.

The present invention is illustrated by a specific example of execution, which, however, is not the only possible, but clearly demonstrates the possibility of achieving the desired technical result.

1 is a color chart 1931 CIE;

FIG. 2 is a 1976 CIE color chart;

figure 3 - emission spectrum of a typical "white" LED type ELSH firm EVERLIGHT, Taiwan;

figure 4 - table of partial indices of color reproduction for the LED in figure 3, CCT = 5600 K according to the passport, CCT = 5000 K according to the measurement results;

figure 5 is a table of partial indices of color reproduction for the LED in figure 3, CCT = 3300 K according to the passport, CCT = 3000 K according to the measurement results;

6 is a graph of the distribution of color matching functions CMF;

7 is a radiation spectrum of a sample TCS01;

Fig - radiation spectrum of the sample TCS02;

Fig.9 is the emission spectrum of the sample TCS03;

figure 10 - radiation spectrum of the sample TCS04;

11 - radiation spectrum of the sample TCS05;

Fig - radiation spectrum of the sample TCS06;

Fig - radiation spectrum of the sample TCS07;

Fig - radiation spectrum of the sample TCS08;

Fig - spectrum of the red test color of the sample TCS08;

Fig. 16 is a spectrum of a group of red monochrome LEDs with shifted (in spectrum) wavelengths (with dominants 615 nm and 635 nm);

Fig - spectral data of the red LED in Fig.16 with a dominant wavelength of approximately 615 nm;

Fig. 18 is a spectral data of the red LED of Fig. 16 with a dominant wavelength of approximately 635 nm;

Fig.19 is a spectrum of a group of turquoise monochrome LEDs with shifted (in spectrum) wavelengths (with dominants of 480 nm and 512 nm);

Fig.20 is the spectral data of the turquoise LED of Fig.19 with a dominant wavelength of approximately 480 nm;

Fig.21 is the spectral data of the turquoise LED of Fig.19 with a dominant wavelength of approximately 512 nm;

Fig - the final spectrum as a result of improving the CRI of the "white" LED;

Fig.23 is a table of partial CRI indices for the lamp of Fig.22;

Fig - position of a point indicating the color of the lamp on the color chart, when adding red LEDs;

Fig - an example of the use of blue-green (turquoise) LEDs with a dominant wavelength of 510 nm to compensate for the introduction of red LEDs;

Fig. 26 is an example of a structure of a lamp with a high Ra value (CRI);

Fig.27 shows the required radiation region in the 1931 CIE color diagram of the "white" LEDs according to the structure in Fig.26;

Fig. 28 is a radiation spectrum of a lamp obtained from the condition for fulfilling all the requirements for LEDs when the structure of the lamp of Fig. 26;

Fig.29 shows a spectrum of a "cold" white LED from Everlight (5000 K);

Fig. 30 shows a spectrum of a “warm” white LED from Everlight (3000 K);

Fig. 31 shows a spectrum of a red LED with a dominant wavelength of 619 nm (desired spectrum);

Fig. 32 shows a spectrum of a turquoise LED with a dominant wavelength of 497 nm (desired spectrum);

Fig - the total spectrum of white "warm" and white "cold" diabetes;

Fig. 34 - spectrum of the combination "white" warm "+ white" cold "+ a lot of red;

Fig - spectrum of the combination of "white" warm "+ white" cold "+ normal red;

Fig - position on the color chart of the resulting point of the lamp without a turquoise LED;

Fig. 37 is a table of partial CRI indices, all colors together, including turquoise;

Fig. 38 is a position on a color chart of a resultant dot of a lamp, all colors together, including turquoise;

Fig. 39 shows a spectrum and parameters of a real red LED used in an experimental lamp;

Fig - shows the spectrum and parameters of a real turquoise LED firm Everlight, used in an experimental lamp;

Fig - graph of the radiation spectrum and a table with the characteristics of the spectrum of a full-color lamp with a black body at the locus (CCT = 3800 K);

Fig - shows a longitudinal section of a possible lamp;

Fig - shows a cross section of the device along the line aa in Fig and the location of the LEDs.

According to the present invention, there is considered a lighting device that comprises a first solid state light source, a second solid state light source, a third solid state light source, a phosphor or a group of phosphors, at least one power line to which the first, second and third solid state light sources are electrically connected, the first mentioned solid state light source is configured to emit light with a dominant wavelength in the range from 430 nm to 480 nm, the second mentioned solid state the light point is configured to emit light with a dominant wavelength in the range of 600 nm to 650 nm, the third solid state light source is configured to emit light with a dominant wavelength in the range of 480 nm to 520 nm, and said phosphor or said group of phosphors being excited, it is possible to emit light with a dominant wavelength in the range from 530 to 585 nm, and when applying power to the specified power line, the combination of light emitted in the absence of other sources of light, the first, second and third mentioned solid state light sources and said phosphor or group of phosphors, forms a mixture of light with the coordinate (x; y) points on the 1931 CIE chromaticity diagram located within 10 MacAdam ellipses of at least one point on the emission line of a completely black body on the 1931 CIE chromaticity diagram, with the combination of light emitted by the first solid-state light source mentioned and said phosphor or a group of phosphors, in the absence of other light sources, produces a sub-mixture of light with coordinates on the 1931 CIE color chart, which fall into the first region on this chart, covered by the first, second, third, fourth, fifth and sixth line segments, the first of which connects the first point with coordinates (0.32; 0.30) and the second point with coordinates (0.315; 0.35), the second - the second and third point with coordinates (0.367; 0.4), the third is the third and fourth point with coordinates (0.44; 0.43), the fourth is the fourth and fifth point with coordinates (0.41; 0.367), the fifth is the fifth and sixth point with coordinates (0.357; 0.33) and sixth - the sixth and first point.

The present invention in terms of the design of the lighting device - the lamp is based on the analysis of the calculation of the Ri coefficients (individual coefficients for each color included in the calculation of the total CRI coefficient) for light sources.

The formulas for calculating the color rendering index are taken from CIE 13.3 - 1995 [CIE 13.3 - 1995. CIE Commission recommendations from 1995]

So, the color shift for each sample in the light of the tested light source is calculated by the formula [1]:

ΔEi = ((ΔU ^* _i ) ² + (ΔV ^* _i ) ² + (ΔW ^* _i ) ² ) ^1/2 , where U ^* , V ^* , W ^* are 1964 CIE universal color coordinates are calculated by the formulas:

,

,

and the Δ sign indicates the difference in the color coordinates of sample i when illuminated with light of test k and sample r source from CIE 13.3 - 1995.

Next, we can calculate (for each sample) the shear index Ri:

Ri = 100-4.6ΔEi

And calculate the total CRI index:

Where Ri are the transmission indices of individual color samples selected from the Mansell samples [Munsell color system.pdf, http://en.wikipedia.org/wiki/Munsell].

It is necessary that the point representing the color of the lamp be on the line of a completely black body (Locus Planck) (Fig. 1). Typically, the deviation from the line of a completely black body should not exceed 0.01 in absolute value.

Lamps whose color is close to the line of a black body can be classified by the so-called correlated color temperature (CCT):

Warm lamps - CCT below 3300 K

Neutral lamps - CCT in the range 3300-5300 K

Cold lamps - CCT above 5300 K

Consider the emission spectrum of a typical "white" LED ELSH company EVERLIGHT, Taiwan (figure 3). As can be seen from the graph in Fig. 3, usually in the so-called “white” LEDs, the spectrum consists of a fairly significant peak in the 450-470 nm region (this is a feature of the design of white LEDs in which phosphors are excited by a powerful monochrome LED, as a rule, blue) and the hilly part of the spectrum, which is formed by the phosphors themselves. For example, consider tables of partial color reproduction indices for two “white” LEDs of the ELSH type by EVERLIGHT, Taiwan (5600 K according to the passport and 5000 K according to the measurement results (Fig. 4), CCT = 3300 K according to the passport and CCT = 3000 K by measurement results (figure 5).

We are interested in the first 8 indices (R ₁ ... R ₈ ), the rest are given for reference and are not involved in the calculation of R _a .

From the study of the components R _{i of the} integral coefficient CRI (R _a ) for the “white” LED, it becomes obvious that the coefficient R ₈ usually has the least value (including due to the distribution of color matching functions CMF [CIE_XYZ.pdf, http: //en.wikipedia.org/wiki/CIE_XYZ]) (Fig.6). R ₈ is a lilac color rendering index. This situation arises due to the design features of white LEDs. Usually, phosphors excited by a blue LED have a maximum in the region of 530-585 nm, and the blue LED power (or the presence of an additional phosphor for the “red” region of the spectrum) is not enough for the correct transfer of the red part of the spectrum. You can also notice that the coefficients R4, R5 have low values. This, too, is a consequence of the design features of the “white” LEDs, namely, a dip in the diagram of the spectral radiation density between the blue excitation light and the green-yellow “reaction hump” of the phosphors. Thus, in order to improve the color rendering index R _a, it is necessary to focus on the correction of precisely these three coefficients.

To obtain a high integral R _a (CRI), it is necessary to correctly reproduce the colors of test samples "No. 4", "No. 5" and "No. 8". The emission spectra for eight samples are shown in Fig.7-14. On Fig separately shows the spectrum of the red test color TCS08.

A careful study of the formulas for calculating the CRI coefficients and color matching functions (CMF) shows that to significantly increase the R ₈ coefficient, it is necessary to add a significant peak in the range of 615-650 nm to the spectrum of the “white” LED (while the blue peak of the phosphor excitation is “white” »LED falls well in the blue peak of the TCS08 spectrum). This can be done using a monochrome red LED or a group of red LEDs with shifted (in spectrum) dominant wavelengths, for example, standard 615 nm, 624 nm, 635 nm (Fig. 16, 17, 18). Thus, it will be possible to significantly increase the value of the coefficient R ₈ , as shown in Figs. 22 and 23. Figs. 18-20 show the spectra and graphs of monochrome turquoise LEDs with shifted dominant wavelengths distributed over the spectrum (for example, 480 nm and 512 nm). . On Fig and 23 shows the spectrum and the table of partial indices, as well as the actual CRI index obtained as a result of improving the "white" LED.

However, adding red LEDs to the lamp causes the color of the lamp to change toward red, and the point indicating the color of the lamp in the color chart “moves out” from the line of the absolutely black body (Fig. 24).

Some manufacturers of LED lamps to compensate for this effect use LEDs with a special type of phosphors, which have a secondary radiation spectrum shifted to the green-yellow part of the color chart (for example, CREE, US patent No. 7213940). However, such compensation is not optimal, since there is an increase in the unevenness of the spectrum in the main (for the human eye) radiation zone and, as a result, the impossibility of obtaining a high CRI coefficient. Also, such “corrected white” TIS (LEDs) are used only in lamps of this design, while it would be highly desirable to use standard “white” TIS (LEDs), which are in mass production and, accordingly, have a low and also constant decreasing cost. In addition, such compensation allows you to adjust the spectrum of only LED lamps with a sufficiently low color temperature (CCT <= 3700 K), while, for example, the European standard EN 12464-1 establishes [EN_12464-1_engl.pdf]: for medical institutions use lamps with CRI> 90 and CCT> 4000 K, for accurate labor-intensive work use lamps with CRI> 90 and CCT> 4000 K, to illuminate artwork use lamps with CRI> 90 and CCT> 4000 K.

In this invention, to compensate for the effect of “sliding” the point from the line of a completely black body (Fig. 24), it is proposed to use the opposite (relative to the “hump” of the phosphor) color, which in this case is TIS (LED) light with a dominant wavelength of 480-520 nm .

Since the radiation spectrum of such a TIS (LED) falls into the "dip" of the radiation of a conventional "white" TIS (LED), then the radiation spectrum of the lamp is further aligned, the indices R ₄ , R ₅ increase and, as a result, the integral coefficient Ra (CRI increases) )

This decision can be approached on the other hand. From considering the shape of the spectrum of samples TCS04, TCS05 (Figs. 10 and 11), it is also obvious that the addition of light with a dominant wavelength of 480-520 nm positively affects the value of the coefficients R ₄ , R ₅ , the value of which usually remains low when using other compensation methods LED spectrum lamp.

On Fig shows an example of the use of blue-green (turquoise) LEDs with a dominant wavelength of 510 nm to compensate for the introduction of red LEDs (see also Fig.19-21 for possible options for the emission spectrum of turquoise LEDs). As can be seen from Fig.25, R _a (CRI) of such a lamp reaches a value of 96.

A further development of this direction may be the use of several types of TIS (LEDs) of blue and blue-green (turquoise) color with shifted wavelengths of radiation in order to fill the dip of the spectral characteristic of the "white" TIS (LED) in the wavelength range of 450-480 nm.

The use of this kind of compensation for the spectrum of white LEDs opens up the possibility of creating simple, inexpensive, high-performance LED lamps (TIS lamps) with a high R _a (CRI) and with the desired color temperature (3000-5000 K). To do this, in the manufacture of lamps it is enough to change the ratio of the number of “warm” and “cold” white LEDs in the group of white LEDs.

The choice of the CCT temperature of the lamp depends on the psychology of the person and the aesthetics of the illuminated objects. Such a choice will depend on the level of illumination, the presence and type of colors in the room, the colors of the furniture and surrounding objects, as well as the climate of the place and scope of the lamp. In a warm climate, lamps with a neutral or “cold” glow are usually preferable, while in a cold climate - “warm” lamps.

On Fig presents a possible structure of the lamp with a high value of Ra (CRI). The structure includes an AC power source 1, through a power corrector block 2 connected to a (quasi) resonant converter 3, supplying power to a power line (bus) 4, to which four current stabilizers 5 are connected, one of which supplies power to the cold "White TIS 6, the second - on the group of" warm "white TIS 7, the third - on the group of TIS (LEDs) 8 with the dominant light emission in the range of 600-650 nm, and the fourth - on the group of TIS (LEDs) 9 with the dominant light emission in the range of 480-520 nm. By adjusting the current through the groups TIS (LEDs), you can adjust the position of the emitting point of the LED lamp in the color chart.

In the LED lamp collected by the author to confirm this decision, the following LEDs were used:

Group of “cold” white TIS - 6 pieces EVERLIGHT EHP-AX08EL / GT01H-P01 / 5063 / Y / K42;

A group of “warm” white TIS - 6 pieces EVERLIGHT EHP-AX08EL-LM01H-P01-3238-Y-K31.

By changing the currents in the circuits of the corresponding LEDs, you can effectively "move" along the 1931 CIE color chart, compensating for the variation in the parameters of different LED instances, as well as the effect of their aging and the effect of uneven decrease in the brightness of various LEDs during heating. So, it is known that red LEDs lose brightness with increasing temperature. So, using a temperature sensor in the lamp circuit, this effect can be eliminated. You can also equip the lamp with a sensor or light flux sensors of different groups of LEDs. This will allow you to directly control the position of the point in the 1931 CIE diagram and allow you to maintain the correct position of this point throughout the life of the lamp.

Studies have been conducted, within the framework of which the requirements for the components of the llama have been established. Requirements for groups of white TIS (LEDs): their radiation should lie in the zone outlined by a black polygon, as shown in Fig.27. This zone is the region of white “cold” LEDs, outlined by the border of points 1-2-3-6, and the region of white “warm” LEDs, outlined by the border of 3-4-5-6, with the following coordinates of these points (3250 K - 6300 TO):

1) (0.32 0.30);

2) (0.315 0.35);

3) (0.367 0.4);

4) (0.44 0.43);

5) (0.41 0.367);

6) (0.357 0.33).

Based on these requirements, the spectral graphs and LED parameters were theoretically determined, at which it would be possible to obtain a combination of light with a point at the locus of an absolutely black body (3800 K). These conditions are presented in FIGS. 28-38.

On Fig shows the emission spectrum of the lamp obtained from the conditions for fulfilling all the requirements for LEDs according to the present invention, and the results of CRI for it. In Fig.29 shows the spectrum of a "cold" white LED from Everlight (5000 K), Fig.30 shows a spectrum of a "warm" white LED from Everlight (3000 K), Fig.31 shows a spectrum of a red LED with a dominant wavelength of 619 nm (required spectrum), Fig. 32 shows a spectrum of a turquoise LED with a dominant wavelength of 497 nm (required spectrum), Fig. 33 shows the total spectrum of white "warm" and white "cold" LEDs, and Fig. 34 shows a spectrum of the combination " white “warm” + white “cold” + a lot of red (as a result, we see a high CRI), Fig. 35 shows the spectrum of the combination warm “warm” + white “cold” + normal red (CRI is lower than in the previous case in Fig. 34), in Fig. 36 is the position on the color chart of the resulting dot of the lamp without turquoise LED, in Fig. 37 is a partial table CRI indices, all colors together, including turquoise, in Fig. 38 - position on the color chart of the resulting dot of the lamp, colors together, including turquoise LED (the color of the lamp is displayed by a dot on the locus of a completely black body (CCT = 3800 K).

The results of using real-life LEDs are shown in Figs. 39-41, where Fig. 39 shows the spectrum and parameters of a real red LED used in an experimental lamp, Fig. 40 shows the spectrum and parameters of a real turquoise LED from Everlight, used in an experimental lamp, and Fig. 41 is a graph of the radiation spectrum and a table with the characteristics of the spectrum of a full-color lamp with a black body (3800 K) entering the locus.

On Fig shows a longitudinal section of the lamp of a possible lamp, and on Fig shows a cross section of the device along the line aa and the location of the LEDs. LEDs 6, 7, 8, 9 (these include white LEDs, red LEDs, turquoise LEDs) are located on the board 10, which has conductive tracks 11, isolated from the base of the board. The heat generated by the LEDs is transferred by the metal base of the board to the device housing 12 having heat-removing ribs 13. The light emitted by the LEDs is reflected by the reflectors 14 and 15 and passes through the diffuser 16.

TIS with a dominant wavelength in the range from 430 nm to 480 nm of light can be made in the form of one LED or more than one LED (group of LEDs), TIS with a dominant wavelength in the range from 600 nm to 650 nm can be made in the form of one LED or more than one LED (group of LEDs), TIS with a dominant wavelength in the range of 480 nm to 520 nm can be made in the form of one LED or more than one LED (group of LEDs). A phosphor or group of phosphors is configured to emit light under the influence of light from said first solid state light source when the latter is turned on. TIS with a dominant wavelength in the range from 430 nm to 480 nm of light in the form of an LED is placed in a housing that also contains a phosphor, or each LED of the first group mentioned is located in a separate housing, each of which also contains one phosphor from the group phosphors. A color mixture formed by a TIS with a dominant wavelength in the range of 430 nm to 480 nm and a phosphor or group of phosphors gives light with a CRI of more than 80 at an efficiency of at least 50 lumens per watt.

The lighting device is provided with at least one electronic key electrically connected to said first power line for selectively turning on and off the current in the first power line. At least one TIS can be made in the form of at least two parallel chains of LEDs connected in series with the first power line. In this case, the lighting device will contain at least one current regulator, directly or through a key, electrically connected to the first or second of these parallel chains of LEDs to control the current through the specified first or second chain of LEDs. This current regulator is performed with an automatic control function to obtain the specified mixture of light of different colors inside 10 MacAdam ellipses from at least one point on the emission line of a completely black body in the 1931 CIE color chart.

The formation of a mixture of light in this lighting device - a lamp, characterized by the coordinate of a point on the 1931 CIE color chart, located within 10 MacAdam ellipses from at least one point on the emission line of a completely black body in this diagram, is carried out by:

- power supply simultaneously to the first solid-state light source in the form of at least one LED for emitting light with a dominant wavelength in the range from 430 nm to 480 nm, the second solid-state light source in the form of at least one LED for emitting light with dominant wavelength in the range from 600 nm to 650 nm, to the third solid-state light source in the form of at least one LED for emitting light with a dominant wavelength in the range from 480 nm to 520 nm and excitation of at least one lumine Ofori with the emission of light with a dominant wavelength in the range from 530 to 585 nm from the light emitted from the first solid-state light source;

- the formation by the light emitted by at least one phosphor, together with the light from the first solid-state light source, of a sub-mixture of light with coordinates on the 1931 CIE color chart, which fall into the first region on this diagram, covered by the first, second, third, fourth , fifth and sixth line segments, the first of which connects the first point with coordinates (0.32; 0.30) and the second point with coordinates (0.315; 0.35), the second - the second and third point with coordinates (0.367; 0, 4), the third - the third and fourth point with coordinates (0.44; 0.43), four fifth - the fourth and the fifth point with the coordinates (0.41; 0.367), the fifth - the fifth and sixth point with coordinates (0.357; 0.33) and sixth - a sixth and the first point;

- adjusting the position of a point on the line of a completely black body in this diagram: increase the number of “cold” and reduce the number of “warm” LEDs or increase the number of “warm” and reduce the number of “cold” LEDs, followed by the addition of red light and turquoise light to display the color on the locus of an absolutely black body.

To navigate in the direction of increasing the color temperature (in the direction of cold color), increase the number of “cold” and reduce the number of “warm” LEDs (1.35 R “cold” and 0.65 R “warm”). Then we add red light to increase CRI and turquoise to display the color at the locus. As a result, the color point of the lamp shifts by 400 K (10%) to the “cold” side along the line of a completely black body. T = 4400 K.

To navigate in the direction of decreasing color temperature (in the direction of warm color), increase the number of warm and reduce the number of “cold” LEDs (1.5 R “warm” and 0.7 R “cold”). Then we add red light to increase CRI and turquoise to display the color at the locus. As a result, the color point of the lamp shifts by 400 K (10%) to the “warm” side T = 3600 K.

Claims (11)

1. Lighting device, characterized in that it contains a first solid-state light source, a second solid-state light source, a third solid-state light source, a phosphor or a group of phosphors, at least one power line to which the first, second and third solid-state light sources are electrically connected , the first said solid state light source is configured to emit light with a dominant wavelength in the range from 430 nm to 480 nm, the second said solid state light source is configured to the light emission with a dominant wavelength in the range from 600 nm to 650 nm, the third solid-state light source is configured to emit light with a dominant wavelength in the range from 480 nm to 520 nm, and said phosphor or said group of phosphors, when excited, made with the possibility of emitting light with a dominant wavelength in the range from 530 nm to 585 nm, and when applying power to the specified power line, the combination of light that was emitted, in the absence of other light sources, the first, second said third solid-state light sources and said phosphor or group of phosphors, the light forms a mixture with the coordinate (x; y) points on the 1931 CIE color chart located within 10 MacAdam ellipses of at least one point on the black body emission line on the 1931 CIE color chart, with the combination of light emitted by the first solid state light source and said phosphor or a group of phosphors, in the absence of other light sources, produces a sub-mixture of light with coordinates on the 1931 CIE color chart, which fall into the first region on this chart, covered by the first, second, third, fourth, fifth and by straight line segments, the first of which connects the first point with coordinates (0.32; 0.30) and the second point with coordinates (0.315; 0.35), the second - the second and third points with coordinates (0.367; 0.4), the third is the third and fourth point with coordinates (0.44; 0.43), the fourth is the fourth and fifth point with coordinates (0.41; 0.367), the fifth is the fifth and sixth point with coordinates (0.357; 0.33), and the sixth - the sixth and first point. 2. The lighting device according to claim 1, characterized in that said first solid-state light source is made in the form of one LED or more than one LED, said second solid-state light source is made in the form of one LED or more than one LED, said third solid-state light source is made in as one LED or more than one LED. 3. The lighting device according to claim 1, characterized in that it is provided with at least one electronic key electrically connected to said first power line for selectively turning on and off the current in said first power line. 4. The lighting device according to claim 1, characterized in that said first phosphor or the entire group of phosphors is configured to emit light under the influence of light from said first solid-state light source when the latter is turned on. 5. The lighting device according to claim 1, characterized in that said first solid-state light source in the form of an LED is placed in a housing in which said first phosphor is also placed, or each LED of said solid-state light source is placed in a separate housing, each of which also one phosphor from the said group of phosphors is placed. 6. The lighting device according to claim 1, characterized in that said color mixture formed by the light of solid-state light sources and a phosphor or group of phosphors emits light with a CRI coefficient of more than 80. 7. The lighting device according to claim 1, characterized in that it has an efficiency of at least 50 Lumens per watt. 8. The lighting device according to claim 1, characterized in that at least one solid-state light source is made in the form of at least two parallel chains of LEDs connected in series with said first power line. 9. The lighting device according to claim 8, characterized in that it contains at least one current regulator, directly or via a key, electrically connected to the first or second of these parallel chains of LEDs to control the current through the specified first or second chain of LEDs. 10. The lighting device according to claim 9, characterized in that said current regulator is provided with an automatic control function for producing said mixture of light of different colors inside 10 MacAdam ellipses from at least one point on the emission line of a completely black body in a color chart 1931 CIE. 11. The method of forming a mixture of light, characterized by a coordinate on the 1931 CIE color diagram of a point located within 10 MacAdam ellipses from at least one point on the emission line of a completely black body in this diagram, which consists in supplying power to the first solid-state light source simultaneously at least one LED for emitting light with a dominant wavelength in the range from 430 nm to 480 nm, a second solid-state light source in the form of at least one LED for emitting light with a dominant wavelength in the range from 600 nm to 650 nm, to a third solid state light source in the form of at least one LED for emitting light with a dominant wavelength in the range from 480 nm to 520 nm, and excitation of at least one phosphor emitting light with a dominant wavelength in the range of 530 nm to 585 nm from the light emitted by the first solid-state light source to form light emitted by the phosphor, together with the light of the first solid-state light source, a sub-mixture of light with coordinates 1931 chromaticity diagram in CIE, which fall into the first region in the diagram enclosed by the first, second, third, fourth, fifth and sixth line segments, the first of which connects the first point with the coordinates (0.32; 0.30) and the second point with coordinates (0.315; 0.35), the second - the second and third point with coordinates (0.367; 0.4), the third - the third and fourth point with coordinates (0.44; 0.43) , the fourth is the fourth and fifth point with coordinates (0.41; 0.367), the fifth is the fifth and sixth point with coordinates (0.357; 0.33), and the sixth is the sixth and first point, and the position of the point on the black line is this diagram is determined by the ratio of the number of “cold” and “warm” white LEDs: increase the number of “cold” and decrease the number of “warm” LEDs or increase the number of TVO warm and reduce the amount of "cold" LED followed by the addition of red light and cyan light to display color on the locus of blackbody.

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