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EP-4736239-A1 - LIGHT-EMITTING DEVICE AND LAMP

EP4736239A1EP 4736239 A1EP4736239 A1EP 4736239A1EP-4736239-A1

Abstract

The invention relates to a light-emitting device (1) comprising at least two LED units (L i , where i = 1, 2, 3) each having: at least one LED chip (C i ) for generating primary light (P i ) with a primary spectrum; and a conversion component (K i ) for converting the primary light (P i ) into secondary light (S i ) with a secondary spectrum that has a greater spectral width than the primary spectrum. The secondary spectra of each of the at least two LED units (L i ) are different from one another.

Inventors

  • Andreev, Zhelio
  • HERNANDEZ GOMEZ, Carlos Roberto
  • KÖCK, Dominik
  • Özgür, Harun

Assignees

  • Würth Elektronik Eisos Gmbh & CO. KG

Dates

Publication Date
20260506
Application Date
20240627

Claims (15)

  1. Patent claims 1. Light-emitting device, in particular LED package, having at least two LED units (L i ; La i ; Lb i ), each with - at least one LED chip (Ci) for generating primary light (Pi) with a primary spectrum and - a conversion component (Ki; Kai; Kbi) for converting the primary light (Pi) into a secondary light (Si) with a secondary spectrum which has a greater spectral width than the primary spectrum, wherein the secondary spectra of different ones of the at least two LED units (Li; Lai; Lbi) are different.
  2. 2. Light-emitting device according to claim 1, characterized in that the secondary spectra of the different LED units (L i ; La i ; Lbi) have different color values.
  3. 3. Light-emitting device according to one of the preceding claims, characterized in that the at least two LED units (L i ; La i ; Lb i ) can be controlled independently of one another in order to set a mixture of the secondary spectra of the at least two LED units (L i ; La i ; Lb i ), in particular by means of an integrated circuit (3) of the light-emitting device (1; 1a; 1b).
  4. 4. Light-emitting device according to one of the preceding claims, characterized in that that the primary light (P i ) of the respective LED chips (C i ) of the at least two LED units (Li; Lai; Lbi) is selected such that the primary spectrum lies entirely within the spectral range of the respective secondary spectrum.
  5. 5. Light-emitting device according to one of the preceding claims, characterized by at least three LED units (Li; Lai; Lbi), whose secondary spectra have color values that correspond to the primary colors of a color system.
  6. 6. Light-emitting device according to claim 5, characterized in that the LED chips (Ci) of the respective LED units (Li; Lai; Lbi) emit primary light (Pi) which corresponds to the basic colors of the respective color system.
  7. 7. Light-emitting device according to claim 5 or 6, characterized by a color rendering index (CRI) of a radiation spectrum obtained by superimposing the secondary spectra of over 70, in particular over 75, in particular over 80.
  8. 8. Light-emitting device according to one of the preceding claims, characterized in that a spectral width of the secondary spectra is between 15 nm and 120 nm.
  9. 9. Light-emitting device according to one of the preceding claims, characterized in that the conversion component (K i ; Ka i ; Kb i ) of at least one LED unit (Li; Lai; Lbi) has quantum dots of different diameters.
  10. 10. Light-emitting device according to one of the preceding claims, characterized in that at least one LED unit (Li; Lai; Lbi) has several LED chips (C i ) whose primary spectra differ.
  11. 11. Light-emitting device according to one of the preceding claims, characterized in that the LED units (Li; Lai; Lbi) are shielded from one another in such a way that light from one LED unit (Li; Lai; Lbi) cannot shine directly into the conversion medium (Ki; Kai; Kbi) of another LED unit (Li; Lai; Lbi ).
  12. 12. Light-emitting device according to claim 11, characterized in that the LED units (Li; Lai; Lbi) are arranged in respective recesses (5) of a substrate (2b).
  13. 13. Light-emitting device according to one of the preceding claims, characterized in that at least one of the conversion components (Ki, Kbi) forms an encapsulation containing a light-converting material for the respective LED chip (Ci).
  14. 14. Light-emitting device according to one of the preceding claims, characterized in that at least one of the conversion components (Ka i ) is applied as a coating to the respective LED chip (Ci).
  15. 15. Luminaire with at least one light-emitting device (1; 1a; 1b) according to one of the preceding claims.

Description

Light-emitting device and lamp The present patent application claims priority from German patent application DE 102023206079.5, the content of which is incorporated herein by reference. The present invention relates to a light-emitting device, in particular in the form of an LED package. The invention also relates to a lamp with at least one such light-emitting device. Light-emitting devices in the form of LED packages are known from prior use. These use one or more LED chips to generate light. Due to the narrow-band radiation characteristics of LED chips, the generation of white light and mixed colors requires special precautions. For example, it is known to combine LED chips of different colors. In particular, the use of red, green and blue LEDs in an LED package to generate white light is known. However, these so-called RGB LED packages, or RGB LEDs for short, have an inhomogeneous spectrum, which leads to poorer color rendering values. In particular, to generate white light, it is also known to convert the primary light of an LED chip into, for example, white secondary light using a light-converting material. However, the resulting spectrum is determined by the light-converting material used and therefore cannot be adjusted. It is an object of the present invention to improve a light-emitting device, in particular to provide a light-emitting device that has a radiation spectrum with high color rendering quality and a high degree of flexibility with regard to the radiation spectrum. This object is achieved by a light-emitting device according to claim 1. The light-emitting device, also called a light emitter, is in particular an LED package. It has at least two LED units. The at least two LED units each have at least one LED chip for generating primary light with a primary spectrum and a conversion component for converting the primary light into secondary light with a secondary spectrum, the secondary spectrum having a greater spectral width than the primary spectrum. The secondary spectra of various of the at least two LED units are different. The device combines the advantages of individual LED units with the broadband radiation characteristics of the respective conversion component. This enables more homogeneous and therefore more color-accurate color mixtures without being limited to the spectrum of a light-converting material. The secondary light of the at least two LED units is superimposed to form a radiation light of the light-emitting device. In other words, the secondary spectra of the at least two LED units are superimposed to form a radiation spectrum. The radiation light with the radiation spectrum is the light emitted by the device and ultimately perceived by the user. The radiation spectrum covers in particular at least part of the visible light. The radiation spectrum can also include parts of the infrared range and/or UV range, depending on the application. The radiation spectrum is preferably in the visible wavelength range, in particular between 380 nm and 780 nm. In particular for generating white light, the radiation spectrum preferably covers at least 50% of the visible wavelength range, in particular at least 75% of the visible wavelength range. The secondary spectra differ. They cover different sub-ranges of the wavelength range covered by the radiation spectrum. The secondary spectra are preferably in the visible wavelength range, in particular between 380 nm and 780 nm. The primary light can be visible light (in particular between 380 nm and 780 nm). The primary light can also have other wavelengths, in particular in the UV wavelength range. The primary light of an LED unit is converted into secondary light by the respective conversion components. The wavelengths of the primary light are preferably selected in such a way that good absorption and re-emission by the respective conversion component is ensured. It is also possible to select the primary light in such a way that the primary spectrum lies entirely in the spectral range of the secondary spectrum. This particularly reliably prevents incorrect colors in the emission spectrum that are due to non-converted primary light. The spectral width of the secondary spectrum is greater than that of the respective primary spectrum. The spectral width is in particular an emission line width, in particular a full width at half maximum (FWHM). Due to the use of LED chips, the primary light is particularly narrow-band. The respective primary spectra can, for example, have a half-width between 5 nm and 20 nm, for example a half-width of approximately 15 nm. The spectral width, in particular the half-width, of the secondary spectra is preferably greater than 15 nm, in particular greater than 20 nm, in particular greater than 30 nm. A particularly suitable range for the spectral width, in particular the half-width, of the respective secondary spectra is between 15 nm and 120 nm. The conversion components in particular comprise at least on