AT14523U1 - LED MODULE WITH SPECIFIC EMISSION CHARACTERISTICS - Google Patents

Abstract

An LED module (1) for presenting merchandise, preferably for presenting food products, more preferably for presenting meat and bakery products, comprising: a blue LED (6), a red or orange LED (5) mounted on a support (3 ) and a color conversion means (7) having a main emission peak in the range of 530nm to 550nm, and wherein the LED module provides a continuous emission spectrum between 380nm and 780nm and the emission spectrum of the LED module has its maximum intensity in the range of 610-670nm and wherein the half width of the emission peak of the color conversion agent is 80-120 nm, and the half width of the maximum intensity peak of the emission spectrum of the LED module is 14-20 nm, preferably 16-18 nm.

Description

description

LED MODULE WITH SPECIAL EMISSION PROPERTIES PRIOR ART

The invention relates to an LED module, a corresponding so-called LED light engine arrangement and a goods display device. In shops, especially in grocery stores, white light illumination with a high proportion of red and / or orange light is often used to improve the presentation of goods. In particular, the use of light sources with red and / or orange hues may improve the appearance of goods having predominantly red and / or orange color (s), such as (fresh) meat, baked, vegetable and fruit products. However, a disadvantage of known and commonly used lighting arrangements such as gas discharge lamps (e.g., fluorescent tubes) is the detrimental effect on the lighted products due to the high UV and IR content of the emitted light.

SUMMARY OF THE INVENTION

Therefore, the present invention improves the presentation of goods, in particular the presentation of food products (e.g., meat or bakery products) while significantly reducing (or completely preventing) damage to the goods.

According to the invention, an LED module with a blue (or UV) LED (as a cube, chip or SMD (Surface Mounted Device1)) is provided with an encapsulation above this, which contains a phosphor or a phosphor mixture. The phosphor (s) give the blue light another fraction (s) of greater wavelength (s), and at least one additional orange and / or red LED is arranged so that the LED module white light with orange and / or red colors is emitted. The spectrum of emitted light of the LED module is continuous in the visible range (380-780nm) and has a sharp (second) peak of 610-670nm in the orange-red area in addition to the threshold region in the range of about 500-600nm (green yellow area). The use of the blue LED results in a blue peak in the range of 430-470nm on the spectrum. The emitted white light with orange / red tones targets a color on the CIE (1964) color value chart with chromaticity coordinates of x = 0.3860, y = 0.3270 and x = 0.4875, y = 0.4045 at a 5 SDCM ( Standard Deviations of Color Matching) MacAdam Ellipse for Illuminating "Meat" or "Back" Products.

In general, a phosphor is used for the various applications by using a blue (or UV) and an additional orange (610-620) and / or red (640-670) LED. A multiple phosphor mixture (with at least two phosphors) can be applied to set certain shades in the white light. Thus, the spectrum can be tailored specifically to a wide range of applications. A flesh lamp can be made with a spectrum that provides a relatively high deep red fraction (in the range of 640-670mn). The emitted light does not comprise any UV component and only a very small amount of IR. The towering red peak ensures optimal reproduction / illumination of the "meat" colors. Accordingly, the presentation of meat products / goods is improved while the quality of the goods remains unchanged.

According to the invention, it is possible to have a certain color setting or a certain spectrum in the shorter red / orange (610-620) wavelength range, for example for the illumination of bakery products, e.g. Bread, or in the yellow-orange area to illuminate cheese products, which also contributes to an ideal presentation of goods. The white light emitted by the device for surface mounting is not limited to aiming for the said color with these chromaticity coordinates by using a spectrum with a distinct orange and / or red peak and a threshold in the green-yellow region, but could also be of any kind be achieved by other spectra.

The invention also relates to an LED light engine assembly comprising, inter alia, an inventive LED module and a device for displaying goods, which includes, inter alia, the aforementioned light engine arrangement. Further features, advantages and characteristics of the invention are explained below on the basis of embodiments and the figures of the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 shows spectra of "meat lamps" according to the invention with a suitable one

Blend of phosphors and a range of state-of-the-art 2800K warm white LED module.

FIG. 2 shows spectra of "baked goods lamps" according to the invention with a suitable one

Blend of phosphors and a range of state-of-the-art 2800K warm white LED module.

FIG. 3 shows the chromaticity coordinates of the light emitted by a "flesh lamp" according to the invention on the UCS color chart CIE 1964.

4 shows the chromaticity coordinates of the light emitted by a "baked goods lamp" according to the invention on the UCS color chart CIE 1964.

Fig. 5 shows an LED module according to an embodiment of the invention.

Fig. 6 shows an LED light engine assembly with LED module (s) according to an embodiment of the invention Ausfüh.

DETAILED DESCRIPTION OF THE DRAWINGS

The invention relates to the generation of an application-specific reddish and / or orange white light using blue (or UV) LED in conjunction with red / orange LED and color conversion means (phosphor, phosphor) for applications in shops, e.g. in grocery stores, bakeries and butchers.

A blue LED having a peak wavelength of about 420-460nm is encapsulated in a color conversion agent (phosphor, down-converted blue light phosphor) to emit white light. The phosphor converts a part of the light emitted by the LED, for example, into yellow and / or green light. In particular, a special phosphor having an asymmetric peak of about 540 nm can be used for this purpose. In addition, at least one orange / red LED (610-670nm) will be installed in the assembly.

As the color conversion agent applicable phosphors could be used for known from the prior art LED. One or more phosphors (phosphor blends) in organic (e.g., silicone resin (s)) or inorganic matrices (e.g., ceramic materials) may be applied to the LED. Alternatively, in the case of different LEDs, different phosphor (s) or phosphors could be used to achieve a particular light color / tint and color distribution.

The color conversion means could be applied directly to the LED e.g. applied as a thin layer or placed in an encapsulant (or cast material), such as in a ball-head covering the LED (e.g., dome-shaped encapsulant). The ball head could cover the at least one LED or more LED applied to the LED module.

The applied LEDs could emit the same or different colors. The applied LED could emit the same or different spectra with the same or different peak wavelengths. The LEDs could be phosphor converted (e.g., white light emitting phosphor converted LED) or monochromatic LED (e.g., monochromatic red LED).

The advantage in particular the use of a blue and red / orange LED to emphasize certain colors by the expert selection of phosphor is that the spectrum has no harmful UV or IR content that affect the goods, especially the food could and yet is suitable for the ideal presentation of goods and storage. However, the invention is not limited to this arrangement.

In this way, an LED module (or a LED light engine) is generated for the presentation of goods in a grocery store with LED, which have a high red and / or orange proportion and their spectrum in particular to a selected product (or selected goods).

Spectra of "meat lamps" (LED modules or light engines) according to a first embodiment of the invention are shown in FIG. The generated spectra are in the range of 380 to 780nm continuous with a clear peak in the range of 640-670nm. In the case of lighting of meat products, it is necessary to ensure that there is a distinctly sharp peak in the red region of long wavelength (e.g., 660nm). A "warm white" light source (commercially available) with a correlated color temperature (COT) of 2800K for general illumination provides a similar sharp red peak, but with shorter wavelength (630nm) as indicated in the third curve of Figure 1. The half width values (FWHM) of the "meat lamp" spectra at 660nm are usually around 14-20nm, especially around 16-18nm. In addition, the spectra have an asymmetric threshold in the range of 500-600nm, which reaches its highest intensity at about 540nm. This fraction of the spectra is basically the emission peak of the applied phosphor (overlapping with the blue and red spectra of the LED). The white light source spectrum of 2800K of the prior art has a relatively symmetrical Schwellanteil with a low intensity peak at about 560nm next to said sharp red peak.

The ratio of the highest intensity of Schwellanteils (phosphorus peak) to the intensity of the red peak is 1: 7-1: 8, while in the case of the commercial 2800K white light source, this value is about 1: 2. This ratio ensures that the meat lamp emits white light with a significant amount of red, which improves the presentation of the meat products. The white shade is exactly matched to the selected product for presentation purposes. The third discernible area of "meat lamp" spectra is the blue LED peak with a wavelength of about 445nm (it could be in the range of 440-470nm).

The values of the color rendering index (CRI) of the "meat lamps" with the spectra given in Figure 1 are about 63, while the known from the prior art light source for general lighting purposes a color rendering index (CRI) of 88 supplies. It shows the different objectives of general lighting and application-specific lighting. In the case of application-specific lighting, the CRI is neglected, but the right white color matched to the illuminated object plays the main role.

In the first embodiment shown in FIG. 1, phosphorus was chosen as the color conversion agent to convert the blue light of the LED into one of longer wavelength that could be combined with the red peak of the additional LED to achieve the desired hue. The emission peak of the deposited phosphor shown in this embodiment is about 540 nm and has a half-width (FWHM) of about 100 nm (80-120 nm). The emission peak of 540nm is asymmetric.

Phosphors to be applied are the phosphors known from the prior art which emit mainly in the green and / or yellow region (these could have an additional emission in the red / orange region). A phosphor with the described emission properties could be selected from the group of silicates (Ca3Sc2Si30i2: Ce3 +), orthosilicates (BOSE), aluminates / garnets (YAG: Ce3 +, YGd) AG: Ce3 +, LuAG: Ce3 +), oxides (CaS-c02 : Eu2 +), SiALONs (α-SiALON: Eu2 +, β-SiALON: Eu2 +), nitrides (La3Si6Nn: Ce3 +, CaAISiN3: Ce3 +), oxynitrides (SrSi2N202: Eu2 +, Ca, Sr, Ba) Si2N202: Eu2 +). The phosphor applied in the first and second embodiments of the present invention may be composed of a garnet containing yttrium and / or lutetium and / or gadolinium and other rare earth metal ions as a dopant (s) and having a particle size of D50 = 17-18 microns.

On the spectra of the "meat lamps" there is a third peak, namely the one corresponding to the blue LED at about 445nm. The mixture of the blue peak (440-470nm) with the sharp red peak (640-670nm) and the shallow green-yellow (threshold about 500-600nm with a half-width (FWHM) of 80-120nm) gives a reddish white light that looks the red shades of meat products, especially in the case of fresh meat products, while the CRI is kept at a relatively low level of 63.

FIG. 2 shows spectra of "baked goods lamps" according to the second embodiment of the invention. The generated spectra illustrate continuous spectra in the range of 380 to 780nm with a clear peak around 610-620nm. In the case of baked goods lighting, a distinctly sharp peak in the red short wavelength range or in the orange wavelength range is beneficial. A commercial "warm white" light source with a correlated color temperature (CCT) of 2800K for general illumination provides a peak in the red region at approximately 630nm. The values of the half-width (FWHM) of the red / orange peak (610-620nm) of the spectra of the "baked goods lamps" are, similar to the commercial ones, usually at about 16-18nm.

In addition, the spectra have an asymmetric Schwellanteil in the range of 500-600nm, which reaches its highest intensity at about 540nm. This peak corresponds to the phosphorus emission. The known from the prior art white light source spectrum of 2800K has a relatively symmetrical Schwellanteil with a low intensity peak at about 560nm.

The ratio of the highest intensity of the Schwellanteils to the intensity of the orange peak is 1: 4-1: 5, while this value is approximately 1: 2 in the case of the commercial 2800K white light source. This ratio ensures that the "baked goods lamp" emits white light with a significant amount of orange, which improves the presentation of the baked goods. The white color is exactly matched to the product selected for presentation purposes. The third discernible range of "baked goods lamp" spectra is the blue LED peak with a peak wavelength around 450nm.

In the second embodiment shown in FIG. 2, the phosphor applied is the same as in the case of the first embodiment. The phosphor (s) used may be selected from the group of phosphors mentioned in the case of the first embodiment. The application of phosphorous mixtures, e.g. a combination of any listed phosphors that give similar emission properties in the green-yellow area could be considered.

The mixture of the blue peak (440-470nm) with the sharp orange (610-620nm) and the flat greenish-yellow peak (swelling fraction, 500-600nm) gives a white light with a high orange tint which gives the appearance of the orange hues of the baked goods improved. The CCT is about 87, which corresponds to the known from the prior art warm light, however, the chromaticity coordinates of the desired color are significantly different (see Figure 4).

Similar to the first and second embodiments, to illuminate any selected product, e.g. For vegetables and fruits with red, orange or yellowish hues (apples, cherries, radishes, mangos, oranges, tomatoes, carrots etc.), a spectrum can be produced.

The color of the "meat lamps" with the spectra according to FIG. 1 could be described by the chromaticity coordinates shown in FIG. 3 by a cross at x = 0.3860, y = 0.3270. The ellipse shows the tolerance range of the 5 SDCM.

The color of the "baked goods lamps" with the spectra according to FIG. 2 could be described by the chromaticity coordinates shown in FIG. 4 by a cross at x = 0.4875, y = 0.4045. The ellipse shows the tolerance range of the 5 SDCM. The 2800K white light source known in the art provides a color with chromaticity coordinates of x = 0.4696, y = 0.4176, represented by the rectangle.

Figure 5 shows an LED module 1 according to another aspect of the invention with two red / orange 5 and a blue LED 6. The LED 5, 6 are on a support 3 (eg, board, circuit board), preferably on a flat Carrier 3 by die attaching means (eg soldering, gluing) attached.

The LED module (s) preferably includes at least one blue LED 5 and two red LEDs 6 under a common ball head 7 to provide suitable color adjustment.

The LED module is preferably a COB (chip-on-board) module. The LEDs are connected in series. The LEDs can be connected via connecting wires and / or soldering thresholds with the electrical paths / conduction paths 4 of the carrier 3. The color conversion agent is applied as a transparent encapsulation in the form of a ball head 7 (hemispherical element) on the LED. The LEDs 5, 6 could be covered by a common ball head 7 or they could be covered separately from individual ball heads. The invention is not limited to the above-mentioned form of encapsulation, but may take any form such as e.g. have a rectangular shape.

The color conversion agent comprises a polymer matrix, e.g. For example, a silicone resin or a silicone resin mixture is incorporated in the (or any type of color conversion agent). In addition, it is additionally possible to apply scattering substances (eg SiO 2, TiO 2, BaTiO 3, BaSO 4, ZrO 2, ZnO, Al 2 O 3) and / or active ingredients for adjusting the rheological properties of the color conversion dispersion used (for example filler particles: SiO 2, silica gel, TiO 2, BaTiO 3, BaSO 4, ZrO 2, ZnO, Al 2 O 3). The transparent encapsulation (ball head) preferably contains 6-9% by weight of phosphorus, more preferably 7-8% by weight of phosphorus.

Preferably, the top of the carrier 8 may be coated with a highly reflective coating layer comprising nonconductive reflective particles, e.g. TiO 2, BaSO 4, ZrO 2, BaTiO 3, Al 2 O 3.

Preferably, an erase diode (e.g., ESD diode) is applied to the carrier 3.

FIG. 6 shows an LED light engine arrangement 9 according to the invention. The LED light engine arrangement 9 preferably consists of a linear LED light engine arrangement. The light engine assembly 9 preferably comprises a cover and / or a housing 10 and preferably in this a lens 11. The lens 11 could be received in the cover / housing 10 according to another aspect of the invention. The light engine assembly 9 comprises (a) LED module (s) 1 according to the invention with certain color settings, e.g. for lighting goods such as food products. The LED modules 1 are preferably mounted in the housing 10, preferably on the aluminum profile (not shown) under the cover 10 / or within the housing 10.

As shown, the light engine may be tied to a ballast, for example by two electrical conductor cables 12, to operate the light engine, although the light engine according to another aspect of the invention may also be connected directly to the power supply.

In a particularly preferred embodiment, an LED light engine assembly 9 according to the invention with an LED module 1 according to the invention on / in a device for displaying goods, such as meat products, baked goods, fruits and vegetables, arranged. The merchandiser may, for example, consist of a shelf, a counter, a refrigerated or frozen display case in a store or market, e.g. a food market. The device has at least the LED light engine arrangement 9 according to the invention and a goods display area for the presentation and display of the goods. REFERENCE LIST: 1 LED module 2 erase diode 3 carrier 4 Electrical path / line path

5 blue LEDs

6 Red LED 7 Color Conversion Device 8 Carrier Top 9 LED Light Engine Assembly 10 Housing / Cover 11 Lens 12 Electrical conductor cable

Claims (16)

Claims 1. LED module (1) for presenting goods, preferably for the presentation of food products, more preferably for the presentation of meat and bakery products, comprising: - a blue LED (6), - a red or orange LED (5) on a carrier (3), and a color conversion means (7) having a main emission peak in the range of 530nm to 550nm, and wherein the LED module provides a continuous emission spectrum between 380nm and 780nm and the emission spectrum of the LED module has its maximum intensity in the Reaches the range of 610-670nm, and wherein the half width of the emission peak of the color conversion agent is 80-120nm and the half width of the maximum intensity peak of the emission spectrum of the LED module is 14-20nm, preferably 16-18nm. 2. LED module (1) for presenting goods, preferably for the presentation of food products, more preferably for the presentation of meat and bakery products, comprising: - a blue LED (6), - a red or orange LED (5) on one Carrier (3), and a color conversion means (7) having a main emission peak in the range of 530nm to 550nm, the emitted color of the LED module being of the chromaticity coordinates of x = 0.3860, y = 0.3270 or x = 0.4875, y = 0.4045 is described with a 5 SDCM MacAdam ellipse. 3. LED module (1) according to claim 1, wherein the emitted color of the LED module (1) of the chromaticity coordinates of x = 0.3860, y = 0.3270 or x = 0.4875, y = 0.4045 is described with a 5 SDCM MacAdam ellipse. 4. LED module (1) according to claim 1 to 3, wherein the ratio of the highest intensity of the emission peak of the color conversion means to the maximum intensity peak of the emission spectrum of the LED module in the range of 1: 41: 8. 5. LED module (1) according to claim 1 to 4, wherein the applied to the LED color conversion agent from the group of garnets, aluminates, silicates, orthosilicates, oxides, SiALONen, nitrides, oxynitrides is selected. 6. LED module (1) according to one of the preceding claims, wherein the applied to the LED color conversion agent has a garnet structure with yttrium and / or lutetium and / or gadolinium and rare earth metal ion (s) as a dopant. 7. LED module (1) according to one of the preceding claims, wherein the LED module (1) has at least one blue LED (6) and two red and / or orange LED (5). 8. LED module (1) according to one of the preceding claims, wherein the LED module (1) has a plurality of blue LED (6) and a plurality of red and / or orange LED (5). 9. LED module (1) according to one of the preceding claims, wherein the blue LED (6) has its emission peak in the range of 440-470nm. 10. LED module (1) according to one of the preceding claims, wherein the red LED (5) has its emission peak in the range of 640-670nm. 11. LED module (1) according to one of the preceding claims, wherein the orange LED (5) has its emission peak in the range of 610-620nm. 12. LED module (1) according to one of the preceding claims, wherein the LED module (1) is a COB module. 13. LED module (1) according to one of the preceding claims, wherein the LED (5, 6) by a common spherical head or individual ball heads (7) are covered, the (/) contain the color-converting /. 14. LED module (1) according to one of the preceding claims, wherein the ball head (s) (7) contains filling and / or scattering means. 15. LED light engine assembly (9), comprising: - a housing or a cover (10), - a lens (11), and - an LED module according to claim 1, wherein the LED module in the housing (10) is arranged. 16. Device for the display of goods, with a display area and an LED light engine assembly (9) according to claim 14. For this 5-sheet drawings