Lighting unit comprising a lamp shade

Abstract

The invention provides a lighting unit (1) comprising (a) a light source (10) configured to provide a beam of light (11), the light source (10) having a light exit surface (12) for escape of the light from the light source (10), (b) a lamp shade (20) partly surrounding the light source (10), wherein the lamp shade (20) has an internal lamp shade surface (21) and a lamp shade light exit (22), and (c) a light conversion element (30), configured partly between the light exit surface (12) of the light source (10) and the lamp shade light exit (22) of the lamp shade (20), wherein the light conversion element (30) comprises a light transmissive part (31), wherein the light transmissive part (31) comprises a luminescent material configured (40) to convert at least part of the beam of light into luminescent material light.

Claims

1. A lighting unit comprising: a light source configured to provide a beam of light, the light source having a light exit surface for escape of the light from the light source, a lamp shade partly surrounding the light source, wherein the lamp shade has an internal lamp shade surface and a lamp shade light exit, wherein the lamp shade light exit is the opening through which the light escapes from the lamp shade, a light conversion element, comprising luminescent material that has a hollow shape having a body axis and that is remote from said lamp shade, wherein the beam of light has an optical axis, wherein the body axis and optical axis coincide, the light conversion element being configured partly between the light exit surface of the light source and the lamp shade light exit of the lamp shade, thereby receiving part of the beam of light during operation of the lighting unit, wherein the light conversion element comprises a light transmissive part, wherein the light transmissive part comprises the luminescent material, wherein the light conversion element is an open structure with an opening disposed toward the lamp shade light exit and wherein the luminescent material is configured to convert at least part of the beam of light into luminescent material light for creating a colored appearance within the lamp shade.

2. The lighting unit according to claim 1, wherein the light transmission part comprises a plurality of transmissive regions having different luminescent properties.

3. Use of the lighting unit according to claim 2, for providing white lighting unit light escaping from the lamp shade light exit while creating a colored appearance within the lamp shade with different colored regions.

4. The lighting unit according to claim 1, wherein the light conversion element comprises a wall, wherein the wall comprises the light transmissive part, and wherein the wall further comprises one or more through holes.

5. The lighting unit according to claim 1, wherein the light conversion element comprises luminescent quantum dots.

6. The lighting unit according to claim 1, wherein the light conversion element comprises embedded micro particulate inorganic luminescent materials.

7. The lighting unit according to claim 1, wherein the light conversion element comprises embedded organic luminescent materials.

8. The lighting unit according to claim 1, wherein the light conversion element comprises embedded micro particulate organic luminescent materials.

9. The lighting unit according to claim 1, wherein the luminescent material comprises a perylene luminescent material.

10. The lighting unit according to claim 1, wherein the light source comprises a solid state LED light source.

11. The lighting unit according to claim 1, wherein the light conversion element is detachably attached to the lighting unit.

12. The lighting unit according to claim 1, wherein the light source is configured to provide light source light with a correlated color temperature in the range of 5000-20000 K.

13. The lighting unit according to claim 1, wherein said light conversion element is one of a plurality of light conversion elements, wherein said one of the plurality of light conversion elements is detachably attached to the lighting unit, wherein each light conversion element of the plurality of light conversion elements is readily attachable to and readily detachable from said lighting unit via a respective connector such that said one of the plurality of light conversion elements is readily replaceable with at least one other light conversion element of the plurality of light conversion elements.

14. The lighting unit according to claim 13, wherein said connector is at least one of one or more screws, one or more snap connectors, a hook and loop fastener, or a magnetic connector.

15. Use of the lighting unit according to claim 1, for providing white lighting unit light escaping from the lamp shade light exit while creating a colored appearance within the lamp shade.

16. The lighting unit according to claim 1, wherein said lighting unit is free of light conversion material along or about said optical axis.

17. The lighting unit according to claim 1, wherein said luminescent material comprises a first subsection configured to produce light of a first wavelength and to illuminate a first region on an inner surface of said lamp shade facing said light conversion element, and comprises a second subsection configured to produce light of a second wavelength and to illuminate a second region on the inner surface of said lamp shade such that said second region appears to have a different color than said first region when viewed by a user during operation of the lighting unit.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Embodiments of the invention will now be described, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, and in which:

(2) FIGS. 1a-1j schematically depict some embodiments and aspects of the lighting unit as described herein.

(3) The drawings are not necessarily on scale

DETAILED DESCRIPTION OF THE EMBODIMENTS

(4) FIG. 1a schematically depicts a lighting unit 1 comprising a light source 10 configured to provide a beam of light 11. The light source 10 has a light exit surface 12 for escape of the light from the light source 10, in this case the surface of the resin on a LED. Other configuration are possible as well, such as a shaped diffuser positioned at the vicinity or remote configurations from the light source 10 or a plurality of light sources (e.g. several LEDs). Further, the lighting unit comprises a lamp shade 20 partly surrounding the light source 10. The lamp shade 20 has an internal lamp shade surface 21 and a lamp shade light exit (22). Reference O indicates the optical axis of the beam of light 11 generated by the light source 10 during operation of the lighting unit 1.

(5) FIG. 1b schematically depicts the same lighting unit, now provided with a light conversion element 30. The light conversion element 30 in the schematically depicted embodiments also partly surrounds the light exit surface 12 of the light source 10.

(6) The light conversion element 30 is arranged partly between the light exit surface 12 of the light source 10 and the lamp shade light exit 22 of the lamp shade 20. In this way, it receives part of the beam of light 11 during operation of the lighting unit 1. This is indicated by the rays r1 and r2, wherein the former travels undisturbed, and whereas the latter illuminates the internal surface of the light conversion element 30. As indicated above, the light conversion element 30 comprises a light transmissive part 31 which comprises a luminescent material 40 configured to convert at least part of the beam of light 11 into luminescent material light, indicated with reference 37.

(7) In most of the schematically depicted embodiment, the light conversion element has a wall 36, which has a first surface 32, directed to the light source 10 (or light exit surface 12 of the light source 10) and a second surface 33, opposite first surface, and facing away of the light source 10, but facing the internal lamp shade surface 21. Light source light 11 illuminates the first surface 32 and luminescent light (i.e. luminescent material light 37) may escape from the opposite second surface 33. A ray responsible for excitation of the luminescent material is indicated with reference r2; the luminescent material light 37 is by way of example further indicated with r3; a ray not being “hindered” by the light conversion element 30 is indicated with reference r1. For instance, the light source light may be white light 11 may be white light, with a blue component, that may be converted by the luminescent material 40.

(8) The light conversion element 30 may have a first opening 41, and a second opening 42, through which part of the light source light enters and exits the light conversion element, respectively. The wall 36 may for instance form a cylindrical or spherical hollow element, through the light source light 11 may travel. The light conversion element 30 may have a body axis be, which may be aligned parallel, or preferably coincide, with the optical axis of the light source 10. The optical axis is indicated with reference O.

(9) FIG. 1c schematically depicts the same embodiment as schematically depicted in FIG. 1b, but now with some more details. By way of example, the interior of the lamp shade 20, indicated with reference 8, may have a colored appearance to an observer, whereas the lighting unit light, indicated with reference 50, may appear white. The lighting unit light is the sum of the light source light 11 downstream of the light conversion element 30 and luminescence material light. Here, the light conversion element 30 has the shape of a cylinder.

(10) FIG. 1d schematically depicts the same embodiment as schematically depicted in FIGS. 1b & 1c, but now the light conversion element 30 comprises a plurality of transmissive regions, indicated with reference 131, 132, . . . , wherein two or more transmissive regions have different luminescent properties, for instance because of the use of different luminescent materials or different combinations of luminescent materials. This may lead to differently colored regions, as indicated with refs R1 and R2. FIG. 1e in detail depicts an embodiment of such light conversion element 30, with different transmissive regions 131, 132 . . . some of them may comprise different types of luminescent materials of different combinations of luminescent materials, which is indicated with references 40(1), 40(2) . . . etc.

(11) In principle, also a patterned light conversion element 30 may be applied. This may give specific patterns, or even logo's, on the lamp shade internal surface 21. This is schematically depicted in FIG. 1f. R1_R4 by way of example indicate differently colored regions. Alternatively or additionally, the light conversion element 30 may also comprise one or more through holes. FIG. 1g schematically depicts such light conversion element 30, comprising a plurality of through holes 231, 232, . . . etc.

(12) FIGS. 1h and 1i schematically depict another embodiment of the light conversion element 30. Here, the element is curved around the body axis B and also around an axis perpendicular to the body axis B. FIG. 1h is added to show that all kind of shapes of the light conversion element 30 may be applied.

(13) FIG. 1j schematically depicts that in the far field another type of light may be obtained than within the lamp shade 20. An object 7, such as a floor, or a wall, at a distance d from the lamp shade light exit 22 may receive white light. In other words, an observer may observe the object 7 to be illuminated with lighting unit light 50, notwithstanding the fact that the lamp shade interior may appear to be colored by colored light (not depicted in this drawing, but see FIGS. 1c-1d and 1f-1h. For instance, a distance d of at least 0.5 m from the lamp shade light exit, the lighting unit light 50 illuminating an object may be perceived white (or having a different color than the color(s) of the light within the lamp shade 20).

(14) FIG. 1k schematically depicts an embodiment wherein the light conversion element 30 can be detachably attached to the lighting unit 1, for with connector(s), for instance attached with one or more screws, with one or more snap-on/snap-off means, a Velcro type of attachment, or may be attached via magnetic means. Here, a screw type of system is schematically depicted.