LIGHTING APPARATUS

Abstract

A lighting apparatus includes at least one primary light source for emitting primary light, at least one phosphor body arranged at a distance from the primary light source, for converting the wavelength of primary light into secondary light, and at least one at least partly dichroic mirror, which at least partly deflects primary light radiated thereon onto at least one phosphor body and which passes secondary light radiated by the phosphor body. Used light radiated by the lighting apparatus contains the secondary light and primary light radiated by at least one primary light source, and the dichroic mirror includes at least one first and second mirror regions, in such a way that the first mirror region deflects primary light onto at least one phosphor body and passes secondary light incident from the phosphor body, and that the second mirror region deflects primary light in a manner circumventing the phosphor body.

Claims

1. A lighting apparatus, comprising at least one primary light source for emitting primary light, at least one phosphor body arranged at a distance from the primary light source, for converting the wavelength of primary light into secondary light, and at least one at least partly dichroic mirror, which at least partly deflects primary light radiated thereon onto at least one phosphor body and which passes secondary light radiated by the phosphor body, wherein used light radiated by the lighting apparatus contains the secondary light and primary light radiated by at least one primary light source, and wherein the at least one at least partly dichroic mirror comprises at least one first dichroic mirror region and at least one second mirror region, in such a way that the at least one first mirror region deflects primary light radiated thereon by at least one primary light source onto at least one phosphor body and passes secondary light incident from the phosphor body, and that the at least one second mirror region deflects primary light radiated thereon by at least one primary light source in a manner circumventing the phosphor body.

2. The lighting apparatus as claimed in claim 1, wherein an area centroid of the second mirror region is arranged within a plane of extent of the first mirror region.

3. The lighting apparatus as claimed in claim 1, wherein the at least one first mirror region and the at least one second mirror region have disjoint areas in relation to an irradiation by the primary light and the secondary light.

4. The lighting apparatus as claimed in claim 3, wherein the at least one first mirror region and the at least one second mirror region practically completely fill a radiation cross section of the secondary light.

5. The lighting apparatus as claimed in claim 1, wherein the at least one second mirror region is a dichroic mirror region.

6. The lighting apparatus as claimed in claim 1, wherein the at least one second mirror region is a non-dichroic mirror region.

7. The lighting apparatus as claimed in claim 1, wherein the at least one first mirror region and the at least one second mirror region are parts of a common mirror.

8. The lighting apparatus as claimed in claim 1, wherein the at least one first mirror region and the at least one second mirror region are separately produced mirrors.

9. The lighting apparatus as claimed in claim 1, wherein the at least one first mirror region and/or the at least one second mirror region is a respectively plane mirror region.

10. The lighting apparatus as claimed in claim 1, wherein the at least one second mirror region is a curved mirror region.

11. The lighting apparatus as claimed in claim 1, wherein the at least one second mirror region is arranged with angular offset, in relation to the at least one first mirror region.

12. The lighting apparatus as claimed in claim 1, wherein the at least one second mirror region is arranged in a circumferentially bounded opening.

13. The lighting apparatus as claimed in claim 1, wherein at least one microlens field is disposed downstream of the at least one first mirror region and the at least one second mirror region.

14. The lighting apparatus as claimed in claim 1, wherein the at least one phosphor body is arranged in a reflecting arrangement.

15. The lighting apparatus as claimed in claim 1, wherein the at least one primary light source comprises at least one semiconductor source.

16. The lighting apparatus as claimed in claim 1, wherein the at least one second mirror region is arranged with angular offset through 90° in relation to the at least one first mirror region.

17. The lighting apparatus as claimed in claim 1, wherein the at least one second mirror region is arranged in a central opening, and/or in an opening, open on an edge side, of a first mirror region.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The above-described properties, features and advantages of the present disclosure and the manner in which they are achieved will become clearer and more easily understandable in conjunction with the following schematic description of embodiments, which are explained in more detail in conjunction with the drawings. Here, for reasons of clarity, the same elements or elements with the same effect may be provided with the same reference sign.

[0040] In the drawings, like reference characters generally refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the disclosed embodiments. In the following description, various embodiments described with reference to the following drawings, in which:

[0041] FIG. 1 shows a side view of a structure of a lighting apparatus including a dichroic mirror in accordance with a first embodiment in a sectional illustration;

[0042] FIG. 2 shows an oblique view of the dichroic mirror in accordance with the first embodiment;

[0043] FIG. 3 shows a side view of a structure of a lighting apparatus including a dichroic mirror in accordance with a second embodiment or a third embodiment in a sectional illustration;

[0044] FIG. 4 shows an oblique view of the dichroic mirror in accordance with the second embodiment;

[0045] FIG. 5 shows an oblique view of the dichroic mirror in accordance with the third embodiment;

[0046] FIG. 6 shows a side view of a structure of a lighting apparatus including a dichroic mirror in accordance with a fourth embodiment in a sectional illustration; and

[0047] FIG. 7 shows a side view of a structure of a lighting apparatus in accordance with a fifth embodiment in a sectional illustration.

DETAILED DESCRIPTION

[0048] FIG. 1 shows a side view of a structure of a lighting apparatus in the form of a LARP headlamp/spotlight 1 in a sectional illustration, for example for vehicle lighting or stage lighting. The LARP headlamp/spotlight 1 includes at least one primary light source in the form of at least one laser 2 (e.g. a laser-diode array, a single laser diode, etc.) in order to radiate a primary light beam made of blue primary light P onto a dichroic mirror 3.

[0049] The dichroic mirror 3 includes a plane first dichroic mirror region 3a and a plane second dichroic mirror region 3b. The two mirror regions 3a and 3b have the same structure and reflect the blue primary light P. While here this refers in a purely exemplary manner to two mirror regions 3a and 3b of a common dichroic mirror 3 (the two mirror regions 3a and 3b are therefore parts of a single mirror 3), the two mirror regions 3a and 3b may be produced separately in an alternative variant and then affixed to one another by means of e.g. an affixment device (a mechanical frame, a solder connection or the like; not depicted here) for the purposes of providing the then multi-part dichroic mirror 3.

[0050] The first mirror region 3a is aligned in such a way that it deflects the primary light P incident thereon onto a phosphor body 5 via a lens 4. Thus, the phosphor body 5 is arranged at a distance from the at least one laser 2, while the first dichroic mirror region 3a is arranged optically between the at least one laser 2 and the phosphor body 5. At the phosphor body 5, the incident component P1 of the primary light P is converted into at least one secondary light S, e.g. into yellow, green, red and/or orange secondary light S.

[0051] On the side thereof facing away from the incident primary light P, the phosphor body 5 is arranged on a carrier 6 which reflects the primary light P and the secondary light S. Consequently, light is only radiated as used light component from that side of the phosphor body 5 on which the primary light beam P1 is also incident. This is also referred to as a “reflecting” or “reflective” arrangement, which has particularly low losses and may be cooled particularly easily. In the present embodiment, the primary light P is completely converted into secondary light S by the phosphor body 5. The secondary light S radiated by the phosphor body 5 is guided onto both mirror regions 3a and 3b by the lens 4. Since both mirror regions 3a and 3b are transmissive for the secondary light S, the secondary light S is provided, practically in the entirety thereof, optically downstream of the dichroic mirror 3, for example for output coupling from the LARP headlamp/spotlight 1.

[0052] The second dichroic mirror region 3b is aligned in such a way that primary light P radiated thereon is deflected in a manner circumventing the phosphor body 5, to be precise in the direction of the secondary light beam S. To this end, the second dichroic mirror region 3b has an angular offset through 90° from the first mirror region 3a, to be precise about an axis of rotation or tilt axis which is perpendicular to a plane spanned by an incoming radiation direction of the primary light P on the first mirror region 3a and a direction of the component P2 of the primary light P reflected at said location onto the phosphor body 5. Here, this plane corresponds to the plane of the sheet.

[0053] As a result, a component P2 of the primary light P is deflected by the second mirror region 3b in a direction which corresponds to the direction of the secondary light S passing through the mirror 3. Thus, the used light radiated by the LARP headlamp/spotlight 1 includes the secondary light S and the primary light component P2 reflected by the second mirror 3b (and therefore directly radiated by the at least one laser 2). By way of example, the used light may be white light, for example based on a blue-yellow color mixture with e.g. additional red and/or orange light components for producing a “warm white” color impression.

[0054] Here, the tilt axis also extends through a central area centroid of the second mirror region 3b, said area centroid being arranged within a planar plane of extent spanned by the first mirror region 3a.

[0055] In respect of the incoming radiation of the primary light P, the first mirror region 3a and the second mirror region 3b are disjoint or non-overlapping such that primary light P incident on the area of the first mirror region 3a facing the at least one laser 2 is not shadowed by the second mirror region 3b. Nor has the secondary light S incident on the second mirror region 3b previously run through the first mirror region 3a.

[0056] As also shown in the oblique view of the dichroic mirror 3 in FIG. 2, the second mirror region 3b is arranged in a central opening 7 of the first mirror region 3a. As a result, the primary light component P2 reflected by the second mirror region 3b extends at least approximately centrally in the secondary light beam S. The component P2 of the primary light P in the used light P2, S may easily be set by way of an area and/or form of the second mirror region 3b and/or, also, e.g. by a cross-sectional area of the primary light P incident on the mirror 3.

[0057] Beam shaping of the used light emanating from the dichroic mirror 3 may be carried out by at least one further optical element (not depicted here).

[0058] FIG. 1 and FIG. 2 can also show a further LARP headlamp/spotlight 8, in which—in the case of the same mirror region 3a-a second mirror region 9b, which has the same form and arrangement as the second mirror region 3b, of an at least partly dichroic mirror 9 does not have a dichroic embodiment, but simply has a specular embodiment. Hence, the second mirror region 9b reflects both the primary light P and the secondary light S. Such a second mirror region 9b may be easier to produce and more cost-effective than the mirror region 3b, particularly in the case of a separate production (in which the two mirror regions 3a and 9b then, in particular, correspond to separate mirrors). Then, the secondary light S incident from the phosphor body 5 onto the second mirror region 9b may be lost.

[0059] FIG. 3 shows a side view of a setup of an LARP headlamp/spotlight 10 including an at least partly dichroic mirror 11, which is also shown in FIG. 4 in an oblique view, in a sectional illustration.

[0060] In contrast to the LARP headlamps/spotlights 1 or 8, a dichroic or non-dichroic second mirror (region) 11b of the mirror 11 is now arranged in an opening 12, open on an edge side, of a first, dichroic mirror region 11a, wherein a tilt axis (perpendicular to the plane of the sheet) of the second mirror region 11b is arranged within the areal extent of the first mirror region 11a. As a result, the component P2 of the primary light P reflected by the second mirror region 11b may extend along the edge in the beam of the secondary light S.

[0061] FIG. 3 may also show an LARP headlamp/spotlight 13, the at least partly dichroic mirror 14 of which is shown in an oblique view in FIG. 5. In comparison with the LARP headlamp/spotlight 10, in this case the second mirror (region) 14b now is not arranged in an opening of an associated first, dichroic mirror region 14a, but instead it is arranged in series therewith. The two mirror regions 14a and 14b have the same width. They adjoin one another along a projection in the direction of the incident primary light P, advantageously in a practically gap-free manner for the purposes of avoiding light losses.

[0062] By way of example, the mirror regions 11b and 14b may alternatively also have a non-dichroic embodiment in this embodiment.

[0063] FIG. 6 shows a side view of a structure of an LARP headlamp/spotlight 15 similar to the LARP headlamps/spotlights 1 or 8 in a sectional illustration. In contrast to these, the dichroic or non-dichroic second mirror region 16b of an at least partly dichroic mirror 16 has a curved embodiment. To be precise, the second mirror region 16b in this case has a convex form in relation to the incident primary light P. As a result, beam-shaping of the reflected primary light beam P2 may be achieved, for example the widening thereof for improved spatial color mixing.

[0064] FIG. 7 shows a side view of a structure of an LARP headlamp/spotlight 17 in a sectional illustration. Here, the LARP headlamp/spotlight 17 has a structure like the LARP headlamp/spotlight 1 or 8 (alternatively, for example, like one of the LARP headlamps/spotlights 10, 13 or 15), wherein the used light P2, S output coupled therefrom is still guided through a microlens field 18 (which is therefore optically disposed downstream of the mirror 11) for the purpose of color mixing. To this end, the microlens field 18 has a field of small lens regions 19 or “lenslets” on both sides. As a result, a homogeneous image may be obtained despite the very different beam diameters of the reflected primary light P2 and of the converted secondary light S. The microlens field 18 may also be referred to as (in this case two-sided) “eye of the fly”.

[0065] Even though the present disclosure was illustrated more closely and described in detail by the shown embodiments, the present disclosure is not restricted thereto and other variations may be derived therefrom by a person skilled in the art, without departing from the scope of protection of the present disclosure.

[0066] Thus, organic or inorganic light-emitting diodes, for example in the form of individual light-emitting diodes or as an LED field or array, etc., may also be used in place of lasers. The LARP headlamps/spotlights may include further optical elements such as stops, lenses, collimators, etc. The dimensions and/or angle relationships may differ from the embodiments; by way of example, different reflection angles may be set.

[0067] Also, a first mirror region may include a plurality of openings arranged on an edge side and/or internal openings with corresponding second mirror regions.

[0068] As a matter of principle, there are no restrictions on the shape and/or size of the mirror regions. Thus, the first mirror regions and/or the second mirror regions need not have a rectangular, in particular square, external contour but, for example, may also have a round, oval or free-form outer contour.

[0069] The tilt angles of a plurality of second mirror regions need not all be equal but may vary as desired, in particular in a range of the tilt angle from 80° to 100°, in particular from 85° to 95°.

[0070] A rotating phosphor wheel which contains one or more sequentially arranged phosphor segments may also be used instead of a stationary phosphor body.

[0071] If a plurality of light sources are present, these may consist of light sources with a similar structure or different structures. The light sources, e.g. laser diodes, may vary, in particular, in terms of the frequency, power and method of operation (constant or pulsed operation, ON or OFF) thereof. Thus, in particular, those light sources whose radiation is incident on the second mirror region may emit a different wavelength and have a different mode of operation to the remaining light sources. By way of example, this may apply to laser diodes and to light-emitting diodes.

[0072] The second mirror regions may also have different forms, i.e., in particular, in terms of the outer form or contour (round, polygonal, elliptic, free-form, etc.) and/or surface curvature (plane, convex, free-form, etc.) thereof.

[0073] Generally, “a(n)”, “one”, etc. can be understood to mean a singular or a plural, in particular in the sense of “at least one” or “one or more”, etc. as long as this is not explicitly excluded, e.g. by the expression “exactly one”, etc.

[0074] Moreover, a numerical indication can encompass exactly the indicated number and also a customary tolerance range, as long as this is not explicitly excluded.

[0075] While the disclosed embodiments have been particularly shown and described with reference to specific embodiments, it should be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the disclosed embodiments as defined by the appended claims. The scope of the disclosed embodiments is thus indicated by the appended claims and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced.