Light generating device having improved performance for disinfection and general lighting

Abstract

The present invention relates to a light generating device (1) configured to generate device light (9), the light generating device comprising a first laser light source (2), a first frequency doubling element (4), a first luminescent element (6), and a light exit window (7). The first laser light source (2) is arranged for generating first laser light (3) being at least one of violet laser light having a first peak wavelength ?.sub.1 selected from a spectral wavelength range from 380 to 420 nm and blue laser light having a second peak wavelength ?.sub.2 selected from a spectral wavelength range from 420 to 490 nm. The first laser light (3) comprises at least a first portion (3) and a second portion (3). The first frequency doubling element (4) is arranged for converting at least a portion of the first portion (3) of the first laser light (3) emitted by the first laser light source (2) into a first frequency doubled light (5) having a third peak wavelength ?.sub.3 selected from a spectral wavelength range from 190 to 245 nm. The first luminescent element (6) comprises a first luminescent material configured to convert at least a portion of the second portion (3) of the first laser light (3) into a first converted light (8) having a fourth peak wavelength ?.sub.4 in one or more of (a) the green spectral wavelength range and (b) the yellow spectral wavelength range. The light exit window (7) is arranged to release the device light (9) comprising the first frequency doubled light (5) and the first converted light (8).

Claims

1. A light generating device configured to generate device light, said light generating device comprising a first laser light source, a first frequency doubling element, a first luminescent element, and a light exit window, wherein: said first laser light source is arranged for generating first laser light being at least one of violet laser light having a first peak wavelength ?.sub.1 selected from a spectral wavelength range from 380 to 420 nm and blue laser light having a second peak wavelength ?.sub.2 selected from a spectral wavelength range from 420 to 490 nm, said first laser light comprising at least a first portion and a second portion; said first frequency doubling element is arranged for converting at least a portion of said first portion of said first laser light emitted by said first laser light source into a first frequency doubled light having a third peak wavelength ?.sub.3 selected from a spectral wavelength range from 190 to 245 nm; said first luminescent element comprises a first luminescent material configured to convert at least a portion of said second portion of said first laser light into a first converted light having a fourth peak wavelength ?.sub.4 in one or more of (a) the green spectral wavelength range and (b) the yellow spectral wavelength range; and said light exit window is arranged to release said device light comprising at least said first frequency doubled light and said first converted light.

2. The light generating device according to claim 1, wherein said at least one of said first peak wavelength ?.sub.1 and said second peak wavelength ?.sub.2 of said first laser light is selected from a spectral wavelength range from 400 to 440 nm and said third peak wavelength ?.sub.3 of said first frequency doubled light is selected from a spectral wavelength range from 200 to 220 nm.

3. The light generating device according to claim 1, wherein said first laser light comprises a third portion and wherein said device light further comprises said third portion of said first laser light.

4. The light generating device according to claim 1, wherein said first luminescent element comprises a second luminescent material arranged to convert a portion of said second portion of said first laser light into a second converted light having an emission band having wavelengths in one or more of (a) a blue spectral wavelength range and (b) a red spectral wavelength range, and wherein said device light further comprises said second converted light.

5. The light generating device according to claim 1, wherein said light generating device comprises a second luminescent element comprising a third luminescent material arranged to convert a portion of said second portion of said first laser light into a third converted light having an emission band having wavelengths in one or more of (a) a blue spectral wavelength range and (b) a red spectral wavelength range, and wherein said device light further comprises said third converted light.

6. The light generating device according to claim 4, wherein said second converted light and/or said third converted light has an emission band having a peak wavelength in the blue spectral wavelength range, and wherein said at least one of said first peak wavelength ?.sub.1 and said second peak wavelength ?.sub.2 of said first laser light is selected from a spectral wavelength range from 400 to 420 nm and said third peak wavelength ?.sub.3 of said first frequency doubled light is selected from a spectral wavelength range from 200 to 210 nm.

7. The light generating device according to claim 1, wherein said first luminescent material is of the type A.sub.3B.sub.5O.sub.12:Ce, wherein A comprises one or more of Y, La, Gd, Tb and Lu, and wherein B comprises one or more of Al, Ga, In and Sc.

8. The light generating device according to claim 1, wherein said light generating device further comprises a second laser light source being arranged for generating second laser being at least one of blue laser light having a wavelength of from 420 to 490 nm and red laser light.

9. The light generating device according to claim 1, wherein said light generating device comprises a splitting optical element arranged for splitting said first laser light into said first and said second portion.

10. The light generating device according to claim 1, wherein said light generating device further comprises a filtering element arranged downstream of said first frequency doubling element for filtering a portion of said first frequency doubled light.

11. The light generating device according to claim 1, wherein said light generating device further comprises a mixing optical element arranged upstream of said light exit window configured to combine at least said first frequency doubled light and said first converted light.

12. The light generating device according to claim 1, wherein said light generating device further comprises one or more sensors arranged to sense the first frequency doubled light and/or the converted light and generate a signal, and a controller arranged to receive said one or more signals and to control said light generating device based on said one or more signals.

13. The light generating device according to claim 1, wherein said light generating device further comprises a second frequency doubling element generating a second frequency doubled light having a peak wavelength different from the peak wavelength of said first frequency doubled light.

14. A luminaire or a lamp comprising the light generating device according to claim 1.

15. A method for operating a light generating device configured to generate device light, said light generating device comprising a first laser light source arranged for generating first laser light being at least one of violet laser light having a first peak wavelength ?.sub.1 selected from a spectral wavelength range from 380 to 420 nm and blue laser light having a second peak wavelength ?.sub.2 selected from a spectral wavelength range from 420 to 490 nm, a first frequency doubling element, a first luminescent element comprising a first luminescent material, and a light exit window, said method comprising the steps of: a) splitting said first laser light into at least a first portion and a second portion; b) converting at least a portion of said first portion of said first laser light emitted by said first laser light source into a first frequency doubled light having a third peak wavelength ?.sub.3 selected from a spectral wavelength range from 190 to 245 nm by means of said first frequency doubling element; c) converting at least a portion of said second portion of said first laser light into a first converted light by means of said first luminescent element, wherein said first converted light has a fourth peak wavelength ?.sub.4 in one or more of (a) the green spectral wavelength range and (b) the yellow spectral wavelength range; d) releasing said device light comprising at least said first frequency doubled light and said first converted light through said light exit window.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Embodiments of the invention will now be described by way of example with reference to the accompanying drawings, of which:

(2) FIGS. 1-5 illustrate different embodiments of the light generating device according to the present invention;

(3) FIG. 6 illustrates different components of the device light generated by the light generating device depicted in FIG. 5.

(4) All the figures are schematic, not necessarily to scale, and generally only show parts which are necessary in order to elucidate embodiments of the present invention, wherein other parts may be omitted or merely suggested.

DETAILED DESCRIPTION

(5) The present invention will now be described hereinafter with reference to the accompanying drawings, in which exemplifying embodiments of the present invention are shown. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments of the present invention set forth herein; rather, these embodiments of the present invention are provided by way of example so that this disclosure will convey the scope of the invention to those skilled in the art. In the drawings, identical reference numerals denote the same or similar components having a same or similar function, unless specifically stated otherwise.

(6) FIG. 1 depicts a light generating device 1 configured to generate device light 9, the light generating device comprising a first laser light source 2, a first frequency doubling element 4, a first luminescent element 6, and a light exit window 7.

(7) The first laser light source 2 is arranged for generating first laser light 3 being at least one of violet laser light having a first peak wavelength ?.sub.1 selected from a spectral wavelength range from 380 to 420 nm and blue laser light having a second peak wavelength ?.sub.2 selected from a spectral wavelength range from 420 to 490 nm. The first laser light 3 comprises at least a first portion 3 and a second portion 3.

(8) The first frequency doubling element 4 is arranged for converting the first portion 3 of the first laser light 3 emitted by the first laser light source 2 into a first frequency doubled light 5 having a third peak wavelength ?.sub.3 selected from a spectral wavelength range from 190 to 245 nm (second harmonic generation). The peak wavelength of the first frequency doubled light 5 is half the peak wavelength of the first portion 3 of the first laser light 3. The first frequency doubling element 2 is optically coupled to the first laser light source 2. By using both types of light the user of the light generating device 1 will be notified about generation of invisible UV light 5 when seeing visible emission 8, thus improving safety of the light generating device 1.

(9) The first luminescent element 6 comprises a first luminescent material configured to convert the second portion 3 of the first laser light 3 into a first converted light 8 having a fourth peak wavelength ?.sub.4 in one or more of (a) the green spectral wavelength range and (b) the yellow spectral wavelength range.

(10) The light exit window 7 of the light generating device 1 of the present invention is arranged to release the device light 9 comprising the first frequency doubled light and the first converted light 8.

(11) Consequently, the light generating device 1 according to the embodiment shown in FIG. 1 generates the device light 9 comprising both UV laser light in the form of the first frequency doubled light 5, and visible light in the form of the first converted light 8. Simultaneous emission of the UV and visible laser light ensures a safe operation of the light generating device 1, while providing the first converted light 8 by means of the first luminescent element 6 improves optical properties of the light generating device 1 by providing high brightness.

(12) As depicted in FIG. 2, a light generating device 101 comprises a first laser light source 102, a first frequency doubling element 104, a first luminescent element 106, and a light exit window 107.

(13) The first laser light source 102 is arranged for generating first laser light 103 being at least one of violet laser light having a first peak wavelength ?.sub.1 selected from a spectral wavelength range from 380 to 420 nm and blue laser light having a second peak wavelength ?.sub.2 selected from a spectral wavelength range from 420 to 490 nm. The first laser light 103 comprises a first portion 103, a second portion 3, and a third portion 103. The first frequency doubling element 104 is arranged for converting the first portion 103 of the first laser light 103 emitted by the first laser light source 102 into a first frequency doubled light 105 having a third peak wavelength ?.sub.3 selected from a spectral wavelength range from 190 to 245 nm (second harmonic generation). The peak wavelength of the first frequency doubled light 105 is half the peak wavelength of the first portion 103 of the first laser light 103. The first frequency doubling element 102 is optically coupled to the first laser light source 102.

(14) The first luminescent element 106 comprises a first luminescent material configured to convert the second portion 103 of the first laser light 103 into a first converted light 108 having a fourth peak wavelength ?.sub.4 in one or more of (a) the green spectral wavelength range and (b) the yellow spectral wavelength range.

(15) The light exit window 107 of the light generating device 101 of the present invention is arranged to release the device light 109 consisting of the first frequency doubled light 105, the first converted light 108, and the third portion of the first laser light 103.

(16) The embodiment depicted in FIG. 3 is similar to the one shown in FIG. 1. As may be seen in FIG. 3, the light generating device 201 comprises a second laser light source 210 being arranged for generating second laser light 211 being at least one of blue laser light having the seventh peak wavelength ?.sub.7 in the range from 420 to 490 nm and red laser light. The device light 209 thus comprises the frequency doubled light 205, the second laser light 211 and the first converted light 208.

(17) FIG. 4 illustrates yet another embodiment of the present invention. As may be seen in FIG. 4, the light generating device 301 is similar to the one shown in FIG. 1. However, only a portion of the second portion 303 of the first laser light 303 is converted into the first converted light 308. The device light 309 will thus consist of the first frequency doubled light 305, the first converted light 308 and the second portion 303 of the first laser light 303.

(18) FIG. 5 illustrates an embodiment similar to the one shown in FIG. 4, wherein a second laser light source 410 is arranged for providing a second laser light 411. The light generating device 401 further a red phosphor material (not shown) being pumped by the second laser light 411 thus providing red phosphor emission 411. In the embodiment depicted in FIG. 5, the device light 409 thus consists of the first frequency doubled light 405, the first converted light 408, the second portion 403 of the first laser light 403, and the red phosphor emission 411. FIG. 6 illustrates these four components of the device light 409.

(19) Although the present invention has been described with reference to various embodiments, those skilled in the art will recognize that changes may be made without departing from the scope of the invention. It is intended that the detailed description be regarded as illustrative and that the appended claims including all the equivalents are intended to define the scope of the invention. While the present invention has been illustrated in the appended drawings and the foregoing description, such illustration is to be considered illustrative or exemplifying and not restrictive; the present invention is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the appended claims, the word comprising does not exclude other elements or steps, and the indefinite article a or an does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.