Light Guide Lamp

Abstract

The present invention provides a light generation system 1000 comprising one or more light generation devices 100, a light guiding element 500, a reflector 410, and optionally a light transmissive enclosure 600, wherein (A) the one or more light generation devices 100 are configured to generate device light 101, (B) the light guiding element 500 comprises a light transmissive body 510 including a light transmissive material 502 that is light transmissive to the device light 101, the light transmissive body 510 includes an elongation axis 501 and a body length L1, the light transmissive body 510 comprises a first end 511 and a second end 512, and the light transmissive body 510 comprises (i) a first outer surface 521 included in the first end 511, (ii) a second outer surface 522 included in the second end 512, and (iii) an outer side surface 523 having a distance d1 connecting the distance between the first outer surface 521 and the second outer surface 521 up to the elongation axis 501, where d1 < L1, and a second outer surface portion 524 of the second outer surface 522 is configured to provide a cavity 530 for accommodating at least a part of the reflector 410, (C) the reflector 410 is a diffusing reflector for the device light 101, and at least a part of the reflector 410 is configured within at least a part of the cavity 530, (D) the one or more light generation devices 100, the light guiding element 500, and the reflector 410 are configured such that (i) at least a part of the device light 101 is incoupled within the light guiding element 500 through the first outer surface 521, (ii) at least a part of the incoupled device light 101 exits the light guiding element 500 through the outer side surface 523 and through the second outer surface 522, for example, through the second outer surface portion (and / or rim portion), and (iii) at least a part of the device light 101 propagated to the second outer surface portion 524 is reflected by the reflector 410, and (E) at least a part of the light guiding element 500 is configured within an optional light transmissive enclosure 600, and the light transmissive enclosure 600 is transmissive to at least a part of the device light 101.

Description

[Technical field]

[0001] The present invention relates to a light generating system and to a lighting device comprising such a system. [Background technology]

[0002] Optical elements and light sources including such optical elements are known in the art. For example, US Patent Application Publication No. 2011 / 0273900 describes an optical element including: a light-transmissive light guide having an input end, an output end, and a central region therebetween, the light-transmissive light guide extending along an axial direction; a light unit including at least one light-emitting diode, the light unit being arranged adjacent to the input end to inject light into the central region; and a reflector arranged adjacent to the output end such that at least a portion of the light incident on the reflector is reflected, the refractive index of the light guide being higher than the refractive index of the medium outside the light guide, at least a portion of the inner boundary surface of the light guide includes a prism surface including a plurality of prisms arranged successively along the axial direction, each prism being arranged at an angle to the axial direction, the reflector having a reflective surface facing the output end and covering at least a portion of the output end, the reflective surface being arranged such that at least a portion of the reflective surface is one of a concave surface and a convex surface. Summary of the Invention [Problem to be solved by the invention]

[0003] It is desirable to have alternative lighting devices that are particularly efficient and / or capable of producing desirable optical effects. Some of the known systems may be complex to manufacture and / or may not provide desirable optical effects. It is further desirable to provide a lighting device that has a substantially Lambertian spatial power distribution. [Means for solving the problem]

[0004] Therefore, one aspect of the present invention is to provide an alternative light generating system and / or a lighting device comprising such a light generating system, which preferably also at least partially obviates one or more of the above mentioned disadvantages. The present invention may have as an object to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative.

[0005] According to a first aspect, the present invention provides an optical generation system (the "system") comprising one or more optical generation devices and an optical guiding element. The optical generation system may optionally further comprise a reflector. In particular, the one or more optical generation devices may be configured to generate device light. In certain embodiments, the one or more optical generation devices may comprise a diode-based light source. Further, in particular, the optical guiding element comprises an optically transparent body comprising an optically transparent material. The optically transparent material may in particular be optically transparent to the device light. In an embodiment, the optically transparent body may include an elongation axis and a body length (L1) defined in particular parallel to the elongation axis. Further, the optically transparent body may comprise a first end and a second end. These ends may define the body length (L1). In particular, the optically transparent body may comprise (i) a first outer surface included in the first end, (ii) a second outer surface included in the second end, and (iii) an outer side surface connecting the distance between the first outer surface and the second outer surface. The outer side surface may have a distance (d1) to the elongation axis. In an embodiment, d1 < L1. In particular, in an embodiment, the first outer surface, the second outer surface, and the outer side surface may define at least a part of the outer surface of the optically transparent body. In an embodiment, the second outer surface portion of the second outer surface may be configured to provide a cavity for accommodating at least a part of the reflector. Moreover, in an embodiment, the reflector may in particular be a diffusing reflector for the device light. Further, in particular embodiments, at least a part of the reflector may be configured to be within at least a part of the cavity. In an embodiment, the one or more optical generation devices, the optical guiding element, and the reflector are in particular configured such that at least a part of the device light can be incoupled into the optical guiding element through the first outer surface, and at least a part of the incoupled device light can exit the optical guiding element through the outer side surface and / or through the second outer surface, for example, through the second outer surface portion (and / or rim portion). In certain embodiments, the reflector may be configured such that a part of the device light propagated to the second outer surface portion can be reflected (by the reflector).Moreover, in an embodiment, the one or more light generating devices, the light guide element, and the reflector may be configured in particular such that a portion of the device light propagated to (and exiting through) the second outer surface may propagate away from the light guide element in a direction having a component parallel to the elongation axis. Furthermore, in an embodiment, at least a portion of the device light propagated to the second outer surface portion may be reflected by the reflector. Moreover, in an embodiment, a range of, in particular, 2-15% of the device light exiting the light generating system may exit within a (virtual) cone having the elongation axis as the cone axis, the cone having a cone angle (θ2) selected from the range of 20-40°. Furthermore, the system may, in an embodiment, comprise a light-transmitting envelope. In particular, in an embodiment, at least a portion of the light guide element may be configured within the light-transmitting envelope. Furthermore, in particular, the light-transmitting envelope may be transparent to at least a portion of the device light.In particular, in (certain) embodiments, the present invention provides a light generation system comprising one or more light generation devices, a light guiding element, a reflector, and a light transmissive enclosure, wherein (A) the one or more light generation devices are configured to generate device light, and the one or more light generation devices comprise a diode-based light source; (B) the light guiding element comprises a light transmissive body including a light transmissive material that is light transmissive to the device light, the light transmissive body including an elongation axis and a body length (L1) defined parallel to the elongation axis, the light transmissive body comprising a first end and a second end defining the body length (L1), the light transmissive body comprising (i) a first outer surface included in the first end, (ii) a second outer surface included in the second end, and (iii) an outer side surface having a (radial) distance (d1) from the connection of the first outer surface and the second outer surface to the elongation axis, where d1 < L1, and the first outer surface, the second outer surface, and the outer side surface define at least a part of the outer surface of the light transmissive body, and the second outer surface portion of the second outer surface is configured to provide a cavity for receiving at least a part of the reflector; (C) the reflector is a (diffusing) reflector for the device light, and at least a part of the reflector is configured within at least a part of the cavity; (D) the one or more light generation devices, the light guiding element, and the reflector are configured such that at least a part of the device light is incoupled into the light guiding element through the first outer surface, and at least a part of the incoupled device light exits the light guiding element through the outer side surface and through the second outer surface, for example, through the second outer surface portion (and / or rim portion), and the reflector is configured such that a part of the device light propagated to the second outer surface is reflected and a part of the device light propagated to the second outer surface propagates away from the light guiding element in a direction having a component parallel to the elongation axis; (E) at least a part of the light guiding element is configured within the light transmissive enclosure, and the light transmissive enclosure is transmissive to at least a part of the device light.Moreover, in the embodiment, the present invention provides a light generation system comprising one or more light generation devices, a light guiding element, a reflector, and an optional light transmissive enclosure, wherein (A) the one or more light generation devices are configured to generate device light, and the one or more light generation devices comprise diode-based light sources; (B) the light guiding element comprises a light transmissive body including a light transmissive material that is light transmissive to the device light, the light transmissive body includes an elongation axis and a body length (L1) defined parallel to the elongation axis, the light transmissive body comprises a first end portion and a second end portion defining the body length (L1), and the light transmissive body comprises (i) a first outer surface included in the first end portion, (ii) a second outer surface included in the second end portion, and (iii) an outer side surface having a distance (d1) connecting the distance between the first outer surface and the second outer surface to the elongation axis, where d1 < L1, and the first outer surface, the second outer surface, and the outer side surface define at least a part of the outer surface of the light transmissive body, and the second outer surface portion of the second outer surface is configured to provide a cavity for accommodating at least a part of the reflector; (C) the reflector is a diffusive reflector for the device light, and at least a part of the reflector is configured within at least a part of the cavity; (D) the one or more light generation devices, the light guiding element, and the reflector are configured such that (i) at least a part of the device light is incoupled into the light guiding element through the first outer surface, (ii) at least a part of the incoupled device light exits the light guiding element through the outer side surface and through the second outer surface, for example through the second outer surface portion (and / or rim portion), and (iii) at least a part of the device light propagated to the second outer surface portion is reflected by the reflector; (E) optionally, at least a part of the light guiding element may be configured within the light transmissive enclosure, and the light transmissive enclosure is transmissive to at least a part of the device light. Moreover, in the embodiment, the one or more light generation devices, the light guiding element, and the reflector are configured such that (iv) 2 to 15% of the device light exiting the light generation system exits within a (virtual) cone having the elongation axis as the cone axis, and the cone has a cone angle (θ2) selected from the range of 20 to 40°.

[0006] Such a light generating system can be provided that can exit from both the side and the top. This can result in the perception of a desired flame shape of light. Furthermore, such a light generating system can be used to combine light from different light sources, minimizing possible crosstalk. Furthermore, the spatial power distribution of the light exiting the light guide element can be controlled by controlling the dimensions of the reflective element, including optional openings in the reflective element. The reflective element, which may be particularly diffusely reflective, can promote color mixing of the device light. Furthermore, optional roughness on the outer surface can also promote color mixing of the device light. However, in such a light generating system, light may exit in a direction having a component parallel to the body axis of the light guide element and in a direction having a component perpendicular to the body axis of the light guide element. Furthermore, a substantially Lambertian type light distribution may be provided for (embodiments of) the light generating system. Furthermore, the present invention can be used to provide a hue light guide lamp. For example, the light generating system may be functionally coupled with a hue controller, or a control system as described herein may be a hue control system.

[0007] As mentioned above, the light-generating system may comprise one or more light-generating devices and a light-guiding element. Additionally, the system may comprise a reflector. Additionally, the system may comprise a light-transmitting envelope.

[0008] In particular, the one or more light-generating devices are configured to generate device light (during operation of the one or more light-generating devices). The one or more light-generating devices may each comprise one or more light sources. Thus, each light-generating device may comprise one or more light sources, more particularly one or more solid-state light sources. Furthermore, the light-generating devices may comprise optical elements. In an embodiment, the light exiting the one or more light sources, i.e. the source light (from the one or more light sources), may be beam-shaped via the optical elements. The device light may in particular comprise the source light. More particularly, the device light may essentially consist of the (source) light of one or more light sources.

[0009] The term "light source" may in principle relate to any light source known in the art. The light source may be a conventional (tungsten) light bulb, a low-pressure mercury lamp, a high-pressure mercury lamp, a fluorescent lamp, an LED (light emissive diode). In a particular embodiment, the light source comprises a solid-state LED light source, such as an LED or a laser diode (or "diode laser"). The term "light source" may also relate to a plurality of light sources, such as 2 to 200 (solid-state) LED light sources. The term LED may therefore also refer to a plurality of LEDs. Furthermore, the term "light source" may also refer in embodiments to so-called chip-on-board (COB) light sources. The term "COB" in particular refers to an LED chip in the form of a semiconductor chip, which is mounted directly on a substrate, such as a PCB, without encapsulation or connection. Thus, a plurality of light-emitting semiconductor light sources may be configured on the same substrate. In an embodiment, the COB is a multi-LED chip, which is configured together as a single lighting module.

[0010] The light source may have a light exit surface. With reference to conventional light sources, such as light bulbs or fluorescent lamps, the light exit surface may be the outer surface of a glass or quartz envelope. With respect to LEDs, the light exit surface may for example be the LED die or the outer surface of the resin if a resin is applied to the LED die. In principle, the light exit surface may also be the end of a fiber. The term exit surface particularly relates to that part of a light source where the light actually leaves or exits from the light source. The light source is configured to provide a beam of light. This beam of light exits (and therefore) from the light exit surface of the light source.

[0011] Similarly, the light-generating device may have a light exit surface, such as an end window.Furthermore, similarly, the light-generating system may have a light exit surface, such as an end window.

[0012] The term "light source" may refer to a semiconductor light emitting device, such as a light emitting diode (LED), a resonant cavity light emitting diode (RCLED), a vertical cavity laser diode (VCSEL), an edge-emitting laser, etc. The term "light source" may also refer to an organic light emitting diode (OLED), such as a passive-matrix organic light emitting diode (PMOLED) or an active-matrix organic light emitting diode (AMOLED). In certain embodiments, the light source includes a solid-state light source (such as an LED or laser diode). In one embodiment, the light source includes an LED (light emitting diode). The term "light source" or "solid-state light source" may also refer to a superluminescent diode (SLED).

[0013] The term LED may also refer to multiple LEDs. Furthermore, the term "light source" may also refer in embodiments to so-called chip-on-board (COB) light sources. The term "COB" refers in particular to an LED chip in the form of a semiconductor chip that is mounted directly on a substrate, such as a PCB, without encapsulation or connection. Thus, multiple semiconductor light sources may be configured on the same substrate. In an embodiment, the COB is a multi-LED chip that is configured together as a single lighting module.

[0014] The term "light source" may also refer to multiple (essentially identical (or different)) light sources, such as 2-2000 solid-state light sources. In embodiments, the light source may include one or more micro-optical elements (array of microlenses) downstream of a single solid-state light source, such as an LED, or downstream of multiple solid-state light sources (i.e., shared, for example, by multiple LEDs). In embodiments, the light source may include an LED with on-chip optical elements. In embodiments, the light source includes a pixelated single LED (with or without optical elements) (which, in embodiments, provides on-chip beam steering).

[0015] In an embodiment, the light source may be configured to provide a primary radiation to be used on its own, for example a blue light source such as a blue LED, or a green light source such as a green LED, and a red light source such as a red LED. Such LEDs, which may not include a luminescent material ("phosphor"), may be directly referred to as color LEDs.

[0016] However, in other embodiments, the light source may be configured to provide a primary radiation, and a portion of the primary radiation is converted to a secondary radiation. The secondary radiation may be based on conversion by the luminescent material. Hence, the secondary radiation may also be denoted as luminescent material radiation. The luminescent material may be included by the light source, such as an LED having a luminescent material layer or a dome containing the luminescent material, in embodiments. Such an LED may be denoted as a phosphor converted LED or a PC LED. In other embodiments, the luminescent material may be configured at some distance from the light source ("remote"), such as an LED having a luminescent material layer that is not in physical contact with the LED die. Thus, in certain embodiments, the light source may be a light source that emits light in operation at a wavelength selected from at least the range of 380-470 nm. However, other wavelengths may also be possible. This light may be used, in part, by the luminescent material.

[0017] In an embodiment, the light-generating device may comprise a luminescent material. In an embodiment, the light-generating device may comprise a PC LED. In other embodiments, the light-generating device may comprise a direct LED (i.e. without phosphor). In an embodiment, the light-generating device may comprise a laser device, such as a laser diode. In an embodiment, the light-generating device may comprise a superluminescent diode. Thus, in a particular embodiment, the light source may be selected from the group of laser diodes and superluminescent diodes. In other embodiments, the light source may comprise an LED.

[0018] The light source may be specifically configured to generate a source light having an optical axis (O), a beam shape, and a spectral power distribution. The source light may have one or more bands, in embodiments having a bandwidth as known for lasers.

[0019] The term "light source" may therefore refer to the light-generating element itself, e.g. a solid-state light source, or to a package of a light-generating element, e.g. a solid-state light source, and one or more of an element containing a luminescent material and (other) optical elements, such as a lens, a collimator. A light converter element ("converter element" or "converter") may include an element containing a luminescent material. A solid-state light source itself, e.g. a blue LED, is a light source. A combination of a solid-state light source (as a light-generating element) and a light converter element optically coupled to the solid-state light source, such as a blue LED and a light converter element, may also be a light source (but may also be indicated as a light-generating device). A white LED is therefore a light source (but may also be indicated as a (white) light-generating device, for example).

[0020] The term "light source" as used herein may also refer to light sources including solid state light sources such as LEDs or laser diodes or superluminescent diodes.

[0021] The term "light source" may therefore also refer in embodiments to a light source based on conversion of light, such as a light source in combination with a luminescent converter material. The term "light source" may therefore also refer to a combination of an LED and a luminescent material configured to convert at least a portion of the LED radiation, or a combination of a (diode) laser and a luminescent material configured to convert at least a portion of the (diode) laser radiation.

[0022] In embodiments, the term "light source" may refer to a combination of a light source, such as an LED, and an optical filter that can change the spectral power distribution of the light generated by the light source. In particular, the term "light-generating device" may be used to refer to a light source and further (optical components), such as optical filters and / or beam shaping elements.

[0023] The phrases "different light sources" or "multiple different light sources" and similar phrases may, in embodiments, refer to multiple solid-state light sources selected from at least two different bins. Similarly, the phrases "same light source" or "multiple identical light sources" and similar phrases may, in embodiments, refer to multiple solid-state light sources selected from the same bin.

[0024] The terms "solid-state light source" or "solid-state material light source" and similar terms may refer to semiconductor light sources, such as light emitting diodes (LEDs), diode lasers, or superluminescent diodes, among others.

[0025] The term "laser source" refers in particular to a laser. Such a laser may in particular be configured to generate laser source light having one or more wavelengths in the UV, visible or infrared, in particular having a wavelength selected from the spectral wavelength range of 200-2000 nm, for example 300-1500 nm. The term "laser" refers in particular to a device that emits light via a process of light amplification based on stimulated emission of electromagnetic radiation.

[0026] In particular, in embodiments, the term "laser" may refer to a solid-state laser. In certain embodiments, the term "laser" or "laser source" or similar terms refer to a laser diode (or diode laser).

[0027] Thus, in an embodiment, the light source comprises a laser light source. In an embodiment, the term "laser" or "solid-state laser" or "solid-state material laser" refers to a laser that is a cerium-doped lithium strontium (or calcium) aluminum fluoride (Ce:LiSAF, Ce:LiCAF), a chromium-doped chrysoberyl (alexandrite) laser, a chromium-ZnSe (Cr:ZnSe) laser, a divalent samarium-doped calcium fluoride (Sm:CaF2) laser, an Er:YAG laser, an erbium-doped and an erbium-ytterbium co-doped glass (Glass Laser), a fluoride-doped ... Lasers, F-center lasers, Holmium YAG (Ho:Nd:YAG) lasers, Nd:YAG lasers, NdCrYAG lasers, Neodymium-doped yttrium calcium oxoborate Nd:YCa4O(BO3)3 or Nd:YCOB, Neodymium-doped yttrium orthovanadate (Nd:YVO4) lasers, Neodymium-glass (Nd:glass) lasers, Neodymium YLF (Nd:YLF) solid-state lasers, Promethium-147-doped phosphate glass (147 Pm 3+ : Glass) solid-state laser, ruby ​​laser (Al2O3:Cr 3+ ), thulium YAG (Tm:YAG) laser, titanium sapphire (Ti:sapphire; Al2O3:Ti 3+ ) lasers, trivalent uranyl doped calcium fluoride (U:CaF2) solid-state lasers, ytterbium doped glass lasers (rod, plate / chip, and fiber), ytterbium YAG (Yb:YAG) lasers, Yb2O3 (glass or ceramics) lasers, etc.

[0028] For example, light sources, including embodiments for second and third harmonic generation, can be F-center lasers, yttrium orthovanadate (Nd:YVO4) lasers, promethium-147 doped phosphate glass (147 Pm 3+ :glass), and titanium sapphire (Ti:sapphire; Al2O3:Ti3+ ) lasers. For example, when considering second and third harmonic generation, such a light source may be used to generate blue light.

[0029] In embodiments, the terms "laser" or "solid state laser" or "solid state laser" may refer to one or more of semiconductor laser diodes, such as GaN, InGaN, AlGaInP, AlGaAs, InGaAsP, lead-salt, vertical cavity surface emitting lasers (VCSELs), quantum cascade lasers, hybrid silicon lasers, and the like.

[0030] The laser may be combined with an upconverter to reach shorter (laser) wavelengths. For example, the upconversion may be obtained by some (trivalent) rare earth ions or the upconversion can be obtained by nonlinear crystals. Alternatively, the laser may be combined with a downconverter, such as a dye laser, to reach longer (laser) wavelengths.

[0031] As can be derived from the following, the term "laser light source" may also refer to a plurality of (different or identical) laser light sources. In certain embodiments, the term "laser light source" may refer to a plurality N of (identical) laser light sources. In an embodiment, N=2 or more. In certain embodiments, N may be at least 5, such as in particular at least 8. In this way, a higher brightness may be obtained. In an embodiment, the laser light sources may be arranged in a laser bank (see also above). The laser bank may in an embodiment include a heat sink and / or optical elements, for example lenses for collimating the laser light.

[0032] The laser source is configured to generate laser source light (or "laser light"). The source light may consist essentially of laser source light. The source light may also include laser source light of two or more (different or the same) laser sources. For example, the laser source light of two or more (different or the same) laser sources may be incoupled into a light guide to provide a single light beam including the laser source light of two or more (different or the same) laser sources. Thus, in certain embodiments, the source light is in particular a collimated source light. In yet further embodiments, the source light is in particular a (collimated) laser source light.

[0033] The laser source light may, in embodiments, have one or more bands, with a bandwidth as known for lasers. In certain embodiments, the band may be a relatively well-defined line, such as one with a full width half maximum (FWHM) in the range of less than 20 nm at room temperature, such as 10 nm or less. The source light therefore has a spectral power distribution (intensity on an energy scale, as a function of wavelength) that may include one or more (narrow) bands.

[0034] The (source light) beam may be a focused or collimated (laser) source light beam. The term "focused" may in particular refer to converging to a small spot. This small spot may be at the individual converter area or (slightly) upstream or (slightly) downstream of the converter area. In particular, the focusing and / or collimation may be such that the cross-sectional shape (perpendicular to the optical axis) of the beam at the individual converter area (at the side) is essentially not larger than the cross-sectional shape (perpendicular to the optical axis) of the individual converter area (where the source light illuminates the individual converter area). The focusing may be performed using one or more optical elements, such as a (focusing) lens. In particular, two lenses may be applied to focus the laser source light. The collimation may be performed using one or more (other) optical elements, such as a collimation element, such as a lens and / or a parabolic mirror. In an embodiment, the beam of (laser) source light may be relatively highly collimated, such as in an embodiment ≦2° (FWHM), more particularly ≦1° (FWHM), most particularly ≦0.5° (FWHM). Therefore, ≦2° (FWHM) may be considered as (highly) collimated source light. Optical elements may be used to provide the (highly) collimated (see also above).

[0035] The term "solid state laser" and similar terms may refer to solid state lasers, such as those based on crystals or glasses doped with ions, such as transition metal ions and / or lanthanide ions, fiber lasers, photonic crystal lasers, and semiconductor lasers, such as vertical cavity surface emitting lasers (VCSELs).

[0036] The term "solid-state light source" and similar terms may refer to semiconductor light sources, such as light emitting diodes (LEDs), diode lasers, or superluminescent diodes, among others.

[0037] One or more of the light-generating devices (of the one or more light-generating devices) may comprise a superluminescent diode. Hence, one or more of the light sources of the one or more light-generating devices may comprise a superluminescent diode.

[0038] Superluminescent diodes are known in the art and may be described as semiconductor devices that may be capable of emitting broad-spectrum, low-coherence light like an LED, while having the brightness of a laser diode.

[0039] U.S. Patent Application Publication No. 2020192017, for example, indicates that "with current technology, a single SLED can emit over a maximum bandwidth of 50-70 nm in the 800-900 nm wavelength range with sufficient spectral flatness and sufficient output power. In the visible range used for display applications, i.e., the 450-650 nm wavelength range, the maximum bandwidth that a single SLED can emit is 10-30 nm with current technology. These emission bandwidths are too small for display or projector applications requiring red (640 nm), green (520 nm), and blue (450 nm), i.e., RGB, emission." Furthermore, superluminescent diodes are described, inter alia, in "Edge Emitting Laser Diodes and Superluminescent Diodes" (Szymon Stanczyk, Anna Kafar, Dario Schiavon, Stephen Najda, Thomas Slight, Piotr Perlin, Book Editor(s): Fabrizio Roccaforte, Mike Leszczynski, First published:03 August 2020 https: / / doi.org / 10.1002 / 9783527825264.ch9 in chapter 9.3 superluminescent diodes). This book, in particular chapter 9.3, is incorporated herein by reference. In particular, the book shows that superluminescent diodes (SLDs) are emitters that combine the characteristics of laser diodes with those of light-emitting diodes. SLD emitters use stimulated emission, which means that these devices operate at current densities similar to those of laser diodes. The main difference between LDs and SLDs is that in the latter case the device waveguide may be designed in a special way to prevent standing wave formation and lasing.Nevertheless, the presence of the waveguide ensures the emission of a high-quality light beam with high spatial coherence, which is simultaneously characterized by low temporal coherence" and "Currently, the most successful designs of nitride SLDs are bent, curved or tilted waveguide geometries, as well as tilted facet geometries, but in all cases the front end of the waveguide meets the device facet in an oblique manner, as shown in Figures 9 and 10. The tilted waveguide suppresses the reflection of light from the facet back into the waveguide by directing the light outwards into lossy unpumped regions of the device chip." Therefore, SLDs can be semiconductor light sources in particular, where spontaneous emission is amplified by stimulated emission in the active region of the device. Such light emission is called "superluminescence". Superluminescent diodes combine the high power and brightness of laser diodes with the low coherence of conventional light-emitting diodes. The low (temporal) coherence of the light source has the advantage that speckle is significantly reduced or not visible, and the spectral distribution of the emitted light is much broader compared to laser diodes, which may make it more suitable for illumination applications. In particular, the spectral power distribution of a superluminescent diode may vary when the current varies. In this way, the spectral power distribution can be controlled, see also, for example, Abdullah A. Alatawi, et al., Optics Express Vol. 26, Issue 20, pp. 26355-26364, https: / / doi.org / 10.1364 / OE.26.026355.

[0040] One or more of the light-generating devices (of the one or more light-generating devices) may comprise a VCSEL. Hence, one or more of the light sources of the one or more light-generating devices may comprise a VCSEL.

[0041] A vertical cavity surface emitting laser, or VCSEL, is known in the art and may be a type of semiconductor laser diode with a laser beam emitting vertically from the top surface, as opposed to an edge emitting semiconductor laser (also called an in-plane laser), which emits from a surface formed by cleaving an individual chip from a wafer. VCSELs may have tunable emission wavelengths, as known in the art. For example, Dupont et al., Applied Physics Letters 98(16):161105 - 161105-3, DOI:10.1063 / 1.3569591, or Wendi Chang et al., Applied Physics Letters 105(7):073303, DOI:10.1063 / 1.4893758, or Thor Ansbaek, IEEE Journal of Selected Topics in Quantum Electronics 19(4):1702306-1702306, DOI:10.1109 / JSTQE.2013.2257164, or CJChang-Hasnain, IEEE Journal of Selected Topics in Quantum Electronics (Volume:6, Issue:6, Nov.-Dec.2000), DOI:10.1109 / 2944.902146, or Kogel et al., IEEE Sensors Journal, December 2007, volume 7, no.11, pages 1483-1489, or Jayaraman, et al., Electron Lett. 2012 Jul 5;48(14):867-869, doi:10.1049 / el.2012.1552, all of which are incorporated herein by reference, describe tunable VCSELs. In particular, when the voltage is varied, the spectral power distribution of the VCSEL may vary. Hence, the term "VCSEL" may refer herein to a tunable VCSEL in particular, as known in the art. Such tunable VCSELs may be based on MEMS technology. Such a (tunable) VCSEL may also be denoted as a "MEMS VCSEL."Thus, in an embodiment, the laser diode may comprise a vertical cavity surface emitting laser (VCSEL) with single mode emission and long coherence length. Wavelength sweeping may be achieved using microelectromechanical systems (MEMS) to vary the length of the laser cavity, resulting in stable and rapid wavelength sweeping.

[0042] Therefore, different spectral power distributions can be generated using the VCSEL. In particular, the VCSEL can be configured to generate laser light (during operation of the VCSEL). Thus, the (VCSEL) laser light can have a controllable spectral power distribution. A control system may be applied to control the spectral power distribution of the (VCSEL) laser light. The control system may be configured to control the spectral power distribution of the (VCSEL) laser light.

[0043] Thus, the one or more light generating devices may in particular comprise a diode-based light source. In certain embodiments, the one or more light generating devices comprise one or more of a light emitting diode, a diode laser, and a superluminescent diode. Light emitting diodes may be useful for this application. Diode lasers can provide a high intensity light source. VCSELs and superluminescent diodes may be color tunable, which may be useful for (further) controlling one or more of color, correlated color temperature, and color rendering index. The term "light emitting diode" may refer to a plurality of light emitting diodes. The term "diode laser" may refer to a plurality of diode lasers. The term "superluminescent diode" may refer to a plurality of superluminescent diodes.

[0044] In an embodiment, the one or more light-generating devices may comprise at least two different light-generating devices, which may differ in that they are configured to generate device light having different spectral power distributions. Thus, in an operational mode of the at least two different light-generating devices, the devices may generate device light having different spectral power distributions. For example, the device light of the at least two different light-generating devices may differ in one or more of color point, correlated color temperature, and color rendering index. Thus, in an operational mode of the at least two different light-generating devices, the devices may generate device light having different color points.

[0045] In particular embodiments, the colors or color points of the first and second types of light may differ if the respective color points of the first and second types of light differ by at least 0.01 with respect to u' and / or at least 0.01 with respect to v', and even more particularly by at least 0.02 with respect to u' and / or at least 0.02 with respect to v'. In even more particular embodiments, the respective color points of the first and second types of light may differ by at least 0.03 with respect to u' and / or at least 0.03 with respect to v', where u' and v' are the color coordinates of the light on the CIE 1976 UCS (uniform chromaticity scale) diagram.

[0046] As mentioned above, the light guide element may comprise a light-transmitting body including a light-transmitting material. In particular, the light-transmitting material is light-transmitting to the device light. Thus, at least a portion of the device light received by the light guide element can be transmitted through the light guide element. More particularly, the light-transmitting material may be essentially light-transparent to the device light.

[0047] The light-transmitting material may be polyethylene (PE), polyethylene naphthalate (PEN), polycarbonate (PC), polyurethane (PU), polymethylacrylate (PMA), polymethylmethacrylate (PMMA) (Plexiglas® or Perspex®), polymethacrylimide (PMI), polymethylmethacrylimide (PMMI), styrene acrylonitrile resin (SAN), cellulose acetate butyrate (CAB), silicone, polyvinylchloride (PVC), and in one embodiment polyethylene terephthalate (PETG), which includes glycol modified polyethylene terephthalate (PETG). The insulating layer may include one or more materials selected from the group consisting of transparent organic materials, such as selected from the group consisting of poly(ethylene terephthalate; PET), polydimethylsiloxane (PDMS), and cyclo olefin copolymer (COC).In particular, the light-transmitting material may be, for example, polycarbonate (PC), poly(methyl)methacrylate (P(M)MA), polyglycolide or polyglycolic acid (PGA), polylactic acid (PLA), polycaprolactone (PCL), polyethylene adipate (PEA), polyhydroxy alkanoate (PHA), polyhydroxy butyrate (PHB), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene ... The light-transmitting material may include an aromatic polyester, such as one or more of polyethylene terephthalate (PTT), polyethylene naphthalate (PEN), or a copolymer thereof. In particular, the light-transmitting material may include polyethylene terephthalate (PET). Therefore, the light-transmitting material is in particular a polymer light-transmitting material.

[0048] However, in another embodiment, the light-transmitting material may comprise an inorganic material. In particular, the inorganic light-transmitting material may be selected from the group consisting of glass, (fused) quartz, a transparent ceramic material, and silicone. Also hybrid materials comprising both inorganic and organic parts may be applied. In particular, the light-transmitting material comprises one or more of PMMA, transparent PC, or glass.

[0049] For example, the optically transparent material may comprise a ceramic body, such as a garnet type material. In an alternative embodiment, the optically transparent material may include an alumina material, such as an Al2O3 based material. In an embodiment, the optically transparent material may include, for example, sapphire. CaF2, MgO, BaF2, A3B5O 12Other materials such as one or more of garnet, ALON (aluminum oxynitride), MgAl2O4 and MgF2 may also be possible.

[0050] In particular, the material has a light transmittance in the range of 50-100%, in particular in the range of 70-100%, for light having a wavelength selected from the visible wavelength range. In this specification, the term "visible light" relates in particular to light having a wavelength selected from the range of 380-780 nm.

[0051] Transmittance (or optical transparency) can be determined by providing light of a particular wavelength having a first intensity to an optically transparent material under normal radiation and relating the intensity of the light of that wavelength measured after transmission through the material to the first intensity of light of that particular wavelength provided to the material (see also E-208 and E-406 of CRC Handbook of Chemistry and Physics, 69th edition, 1088-1989).

[0052] In certain embodiments, a material may be considered transparent if the transmission of radiation of a wavelength or range of wavelengths, particularly of the wavelength or range of wavelengths of radiation produced by a source of radiation as described herein, through a layer of material having a thickness of 1 mm, and even more particularly through a layer of material having a thickness of 5 mm, under normal illumination by that radiation, is at least about 20%, such as at least 40%, such as at least 60%, particularly such as at least 80%, such as at least about 85%, even such as at least about 90%.

[0053] Optically transparent materials have light guiding or waveguiding properties. Therefore, optically transparent materials are also referred to herein as waveguide or light guide materials. Optically transparent materials will generally have (some) transmittance of one or more of (N)UV, visible, and (N)IR radiation, for example, in embodiments, at least visible light, in a direction perpendicular to the length of the optically transparent material. In the absence of activators (dopants) such as trivalent cerium, the internal transmittance in the visible range can approach 100%.

[0054] Thus, the transmittance of the light-transmitting material for one or more luminescence wavelengths may be at least 80% / cm, such as at least 90% / cm, even more particularly at least 95% / cm, such as at least 98% / cm, for example at least 99% / cm. 3 This means that a cube-shaped piece of optically transparent material will have a transmittance of at least 95% under normal illumination with radiation having a selected luminescence wavelength (such as a wavelength corresponding to the emission maximum of the luminescence of the luminescent material of the optically transparent material).

[0055] In this specification, the values ​​for the transmittance in particular refer to the transmittance that does not take into account Fresnel losses at the interface (e.g. with air). The term "transmittance" therefore in particular refers to the internal transmittance. The internal transmittance may for example be determined by measuring the transmittance of two or more bodies having different widths, the transmittance of which is measured. Then, based on such measurements, the contribution of the Fresnel reflection losses and (as a result) the internal transmittance can be determined. In particular, the values ​​for the transmittance given in this specification therefore ignore the Fresnel losses.

[0056] In an embodiment, an anti-reflective coating may be applied to the luminescent body, such as to suppress Fresnel reflection losses (during the process of light in-coupling).

[0057] In addition to the high transmission for the wavelength of interest, the scattering for said wavelength may also be particularly low. Therefore, the mean free path for the wavelength of interest, taking into account only scattering effects (and therefore not taking into account possible absorption (which should be low anyway, taking into account the high transmission)), may be at least 0.5 times the length of the body, such as at least the length of the body, such as at least twice the length of the body. For example, in an embodiment, the mean free path, taking into account only scattering effects, may be at least 5 mm, such as at least 10 mm. The wavelength of interest may in particular be the wavelength at the maximum emission of the luminescence of the luminescent material. The term "mean free path" is in particular the average distance that a light ray will travel before experiencing a scattering event that changes its propagation direction.

[0058] In embodiments, an element that includes a light-transmitting material may consist essentially of the light-transmitting material. In certain embodiments, an element that includes a light-transmitting material may be a light-transparent element.

[0059] In particular, an optically transmissive element, such as an optically transparent element, may have an absorption length and / or scattering length that is, in embodiments, at least the length (or thickness) of the optically transmissive element, for example at least twice the length of the optically transmissive element. The absorption length may be defined as the length along the propagation direction where the intensity of light drops by 1 / e due to absorption. Similarly, the scattering length may be defined as the length along the propagation direction where the light drops by a factor 1 / e due to losses due to scattering. Here, the length may therefore in particular refer to the distance between the primary and secondary surfaces of the optically transmissive element, and the optically transmissive material is configured between the primary and secondary surfaces. The first and second outer surfaces may be the primary and secondary surfaces, respectively.

[0060] The light-transmitting body may comprise an elongation axis and a body length (L1) defined parallel to the elongation axis. The body length may be selected, for example, from the range of 2 to 150 mm, particularly at least about 5 mm, more particularly at least about 10 mm. Thus, in certain embodiments, the light-transmitting body may have a body length selected from the range of about 10 to 100 mm, for example, particularly selected from the range of about 15 to 150 mm. Instead of the term "elongation axis", the term "body axis" may be applied. In particular, the light-transmitting body may be essentially symmetrical with respect to the body axis.

[0061] In an embodiment, the light-transmitting body may have a substantially circular (perpendicular to the elongation axis) cross section. Here, the term "substantially" is used because, as described below, in some embodiments, there may be a relatively small modulation of the outer surface, which is relatively small compared to its diameter. Alternatively, the light-transmitting body may have a substantially n-sided (perpendicular to the elongation axis) cross section, n≧2. When n=2, the side may be curved, and when n is 3 or more, the side may be curved or (substantially) flat. In particular, when the light-transmitting body has a substantially n-sided (perpendicular to the elongation axis) cross section, n≧6, more particularly n≧8, for example even more particularly n≧12, even more particularly n≧24. However, in particular, the light-transmitting body may have a substantially circular (perpendicular to the elongation axis) cross section.

[0062] Thus, in an embodiment, the light-transmitting body may have a tubular or cylindrical shape. Thus, the light-transmitting body may be a tubular body or a (solid) cylindrical body. One end may be defined by a first outer surface, another end may be defined by a second outer surface, and the outer surface may be defined by an outer side surface.

[0063] In particular, in an embodiment, the optically transparent body comprises a first end and a second end defining a body length (L1), the optically transparent body comprises (i) a first outer surface included in the first end, (ii) a second outer surface included in the second end, and (iii) an exterior side spanning the distance between the first and second outer surfaces. The exterior side may have a (radial) distance (d1) to the elongation axis.

[0064] In general, the distance d1 may be essentially the same across a particular cross-section (perpendicular to the elongation axis), except for any expected optional modulations (see also below). Furthermore, in embodiments, the distance d1 may be essentially the same across substantially each cross-section (perpendicular to the elongation axis) along the elongation axis, except for any expected optional modulations (see also below).

[0065] However, it is not excluded that the light-transmitting body has (some degree of) tapering over at least part of the length of the light-transmitting body. Thus, in an embodiment, the light-transmitting body may have, for example, a conical or pyramidal shape. However, in particular, the light-transmitting body has an essentially cylindrical shape.

[0066] Therefore, d1 may specifically refer to a radius. Thus, the outer side may be at a distance d1 equal to the radius of the light-transmitting body from the elongation axis. As will be clear to one skilled in the art, the distance d1 may be determined perpendicular to the elongation axis. The elongation axis may at least partially coincide with the optical axis of the light-generating system.

[0067] In particular, the optical axis may be defined as an imaginary line that defines the path along which light propagates through the system, starting from a light generating element, here in particular a light source. In particular, the optical axis may coincide with the direction of light having the maximum radiant flux.

[0068] In particular, in the embodiment, d1 < L1. For example, 0.01×L1 ≦ d1 ≦ 0.5×L1. However, other values may also be possible. Instead of or in addition, in the embodiment, d1 may be selected from the range of 4 to 15 mm, for example, may be selected from the range of about 6 to 10 mm. However, other values may also be possible.

[0069] A light transmissive body having a length selected from the range of 10 to 150 mm and a distance d1 (or a radius in the embodiment) selected from the range of about 4 to 15 mm, with d1 < L1, particularly d1 ≦ 0.5×L1, seems to yield good (simulation) results.

[0070] The light guide element may comprise an outer surface. A part of this outer surface may receive at least a part of the device light. This part may be the first outer surface or may be included in the first outer surface. A second outer surface may be configured at a distance approximately the length of the light guide element. A part of the coupled-in light can escape through the second outer surface. There is an outer side surface between the first outer surface and the second outer surface. This may in particular be the outer surface of a light guide element having, for example, a cylindrical shape, a tubular shape, or a conical shape. Therefore, the first outer surface, the second outer surface, and the outer side surface define at least a part of the outer surface of the light transmissive body. For example, the outer surface of the light transmissive body may consist essentially of the first outer surface, the second outer surface, and the outer side surface. In an embodiment, the first outer surface may be essentially planar. Further, in an embodiment, the second outer surface may comprise two parts, one part being essentially parallel to the first outer surface and one part being configured to be inclined with respect to the elongation axis. The outer side surface may surround (encircle) the elongation axis in the circumferential direction.

[0071] In particular, the second outer surface portion of the second outer surface is configured to provide a cavity for accommodating at least a portion of the reflector. The second outer surface may therefore comprise a (first) portion that may be (substantially) perpendicular to the elongation axis. This portion is also denoted herein as a rim portion. The second outer surface may comprise a (second) portion, denoted herein as a "second outer surface portion", that may be inclined to the elongation axis. The incoupled device light may escape from the system via the first portion, while the escape of the device light via the second outer surface portion may be limited due to the presence of the reflector.

[0072] A rim portion of the second outer surface may be configured essentially parallel to the first outer surface. Thus, a portion of the second outer surface may be configured parallel to the first outer surface. Due to the presence of a cavity (for a reflector), at least a portion of the second outer surface may not be parallel to the first outer surface.

[0073] The reflector may be a specular reflector for the device light, or may be a diffuse reflector for the device light. In particular, the reflector is a diffuse reflector for the device light. The diffuse reflector may facilitate color mixing of the device light. Furthermore, the (diffuse) reflector may reduce direct viewing back to one or more light-generating devices (through the light guide element). At least a part of the device light reflected by the reflector may reenter the light guide element. Thereby, the device light may have a chance to exit the light guide element again. In particular, in an embodiment, the diffuse reflector for the device light may be a diffuse reflector when the device light shines perpendicularly on the diffuse reflector.

[0074] The reflector may optionally include one or more through holes (see further below).

[0075] In particular, at least a portion of the reflector may be arranged within at least a portion of the cavity. Thus, one may have a reflector whose shape may be essentially complementary to the cavity. Thus, the reflector and the cavity may be arranged in a male-female configuration. Nevertheless, in embodiments, it may be desirable to reduce optical contact between the reflector and the second outer surface (see also below).

[0076] Thus, in operation, one or more light-generating devices generate device light, and at least a portion of the device light enters the light guide element via the first outer surface. The incoupled device light propagates through the light guide element via total internal reflection. However, some of the incoupled light can exit the light guide element via (i) the second outer surface, e.g. via the second outer surface portion (and / or via the rim portion), and / or even (ii) via the outer side surface, in particular via both. Thus, in an embodiment, the one or more light-generating devices, the light guide element, and the reflector may be configured such that at least a portion of the device light is incoupled within the light guide element via the first outer surface, and at least a portion of the incoupled device light exits the light guide element via the outer side surface and via the second outer surface, e.g. via the second outer surface portion (and / or via the rim portion).

[0077] The phrase "at least a portion of the incoupled device light exits the light guide element through the external side and through the second outer surface" and similar phrases may indicate, in particular, that a portion of the device light within the light guide element exits the light guide element through the external side and a (different) portion of the device light within the light guide element exits the light guide element through the second outer surface.

[0078] A portion of the device light exiting the second outer surface may exit the system in a direction having a component parallel to the elongation axis. For example, the intensity (in watts) defined by the full width at half maximum may lie within a (virtual) cone having a cone angle selected from the range of 45-175°. In particular, the beam of light exiting the light guide element (total) may be relatively wide and the full width at half maximum may lie within a (virtual) cone having a cone angle selected from the range of 45-175°. The cone axis may essentially coincide with the elongation axis. Furthermore, a portion of the device light exiting the second outer surface portion may be reflected back into the light guide element. In particular, the reflector may be configured such that a portion of the device light propagated to the second outer surface portion is reflected and a portion of the device light propagated to the second outer surface propagates away from the light guide element in a direction having a component parallel to the elongation axis.

[0079] In particular, in an embodiment, a range of 1-30%, more specifically 2-15%, of the device light exiting the light generating system exits within a (virtual) cone having the elongation axis as the cone axis, the cone having a cone angle (θ2) selected from the range of 20-40°. Thus, the cone may have, for example, a cone angle of about 30°, for example, within which a range of 2-15% of the device light exiting the light generating system is found. Here, the percentage refers to the percentage in watts of the total spectral power in the visible wavelength range. Thus, the cone may have, as the cone axis, an axis essentially coinciding with the elongation axis, and the tapering may be in the direction from the second end to the first end.

[0080] Therefore, a Lambertian distribution of the device light (or system light including the device light) can be obtained. In certain embodiments, the system light may exit the system at essentially any angle within the hemispherical intensity of the device light, within a hemisphere having a hemispherical axis essentially coinciding with the elongation axis, or within a larger hemisphere.

[0081] Thus, the phrase "particularly in the range of 2-15% of the device light that exits the light generating system exits within a (virtual) cone having an elongation axis as the cone axis, the cone having a cone angle (θ2) selected from the range of 20-40°" may also indicate that a significant portion may exit the system outside this cone (but in embodiments into a cone having a larger cone angle).

[0082] The light guide element, or in particular at least a part thereof, more in particular at least the second outer surface part, may be arranged in a light-transmitting envelope such as a "light bulb". Thus, at least a part of the light guide element is arranged in a light-transmitting envelope, which is transparent to at least a part of the device light. The light-transmitting envelope may comprise a light-transmitting material as described above in relation to the light guide element. In particular, the light-transmitting envelope may be based on glass. The light-transmitting envelope may have a retro shape like previous tungsten-based lamps. In this respect, the light-generating system may therefore be provided as a retrofit lamp (see also further below). The light-transmitting envelope may enclose a volume at least twice the volume of the light guide element, for example at least three times the volume of the light guide element, for example up to about 20 times the volume of the light guide element. The light-transmitting envelope may have an essentially spherical shape. In embodiments, the light-transmitting envelope may have a general (A) shape, or a mushroom shape, or an oval (E) shape, or a sine (S) shape.

[0083] The light generating device, light guide element, and reflector may be configured such that of all device light exiting the light generating system, at most about 40% exits the light guide element through the second outer surface, and at most about 60% exits the light guide element through the outer side surface. In an embodiment, 5-30%, for example at most about 25%, of all device light exiting the light generating system exits the light guide element through the second outer surface. Alternatively or additionally, in an embodiment, 55-98%, more specifically 65-90%, of all device light exiting the light generating system exits the light guide element through the outer side surface, and at most about 2-45%, more specifically 10-35%, of all device light exiting the light generating system exits the light guide element through the second outer surface. Here, percentages refer to percentages in watts of total spectral power in the visible wavelength range. Thus, most of the light can escape through the outer side, but some of the light can escape through the second outer surface, particularly the portion of the second outer surface that is essentially perpendicular to the elongation axis. In this way, in embodiments, a substantially Lambertian light distribution can be provided.

[0084] To facilitate outcoupling of the device light from the light guide element, it may be useful to provide a structure on the external side and / or the second external surface. The structure may be, for example, a surface roughness. The surface roughness may reduce the likelihood of internal (total) reflection.

[0085] Therefore, the surface roughness of the external side surface may be selected to outcouple a portion of the device light within the light guide element. Therefore, in an embodiment, at least a portion of the external side surface may have a surface roughness to facilitate outcoupling of the device light from the light transmissive body via the external side surface. In an embodiment, the surface roughness may have an Ra value selected from the range of 0.16 to 0.64 μm. In an embodiment, the surface roughness may have an RMS value selected from the range of 7.90 to 31.30. Furthermore, in a more specific embodiment, the surface roughness may have an Ra value selected from the range of 0.32 to 0.5 μm. In an embodiment, the surface roughness may have an RMS value selected from the range of 15.8 to 24.5.

[0086] In an embodiment, at least a portion of the external side surface may comprise a repeating structure. The structure may have a sawtooth shape, a triangular shape, a square shape, and a sinusoidal shape (sinusoidal). However, other shapes may also be possible. The repeating structure may be 1D or 2D. If the repeating structure is 1D, it may be elongated and substantially parallel to the axis of elongation. The repeating structure may have a period (p) and a distance between the peak and the valley (dct) (which may be twice the amplitude in an embodiment), both of which may be individually selected from the range of 0.1 to 4 mm, for example 0.2 to 5 mm. The repeating structure may facilitate color blending.

[0087] The period (p) and the distance between the peaks and valleys (d ct ) may each individually be substantially smaller than the (radial) distance d1. For example, in an embodiment, 0.001≦p / d1≦0.1 and / or 0.001≦p / d ct ≦0.1.

[0088] In certain embodiments, the surface roughness of at least a portion of the exterior side surface may be superimposed into a repeating structure, such as a sinusoidal shape.

[0089] It should be noted that the surface roughness of at least a portion of the exterior side surface may be uniformly distributed or in other embodiments may have a gradient. For example, the roughness (Ra and / or RMS) may be greater closer to the second exterior surface than to the first exterior surface. For example, the difference in roughness may vary continuously or stepwise between the first and second roughness. The difference in roughness along the exterior side surface, if any, may be at least on the order of a factor of two.

[0090] Thus, the light guide element may be essentially completely transparent, except for the exterior side surface, which has a surface roughness that renders the surface opaque, and except for at least a portion of the second exterior surface, particularly the rim, which may have a surface roughness that renders the surface opaque. The surface roughness may improve color mixing.

[0091] When a repeating structure is applied, the repeating structure may extend in particular to the second outer surface. In this case, it is believed that the light distribution may be improved. Therefore, in a particular embodiment, the edge defined by the outer side surface and the second outer surface (also the edge) may comprise a repeating structure shape. Moreover, in a further particular embodiment, the edge defined by the outer side surface and the second outer surface comprises a sinusoidal shape.

[0092] As mentioned above, the second outer surface may also have a surface roughness. This may facilitate outcoupling of device light from the optically transparent body via the second outer surface. In particular, a rim that may be configured between the outer side and the cavity may include such a surface roughness. The surface roughness of at least a portion of the second outer surface may be substantially uniformly distributed in embodiments, although gradients in the surface roughness are not excluded.

[0093] Thus, in embodiments, at least a portion of the second outer surface may have a surface roughness to facilitate outcoupling of device light from the optically transmissive body through the second outer surface. In certain embodiments, the surface roughness (of at least a portion of the second outer surface) may have an Ra value selected from the range of 2.03 to 6.30 μm. In certain embodiments, the surface roughness (of at least a portion of the second outer surface) may have an RMS value selected from the range of 98.90 to 306.20. Even more specifically, in embodiments, the surface roughness (of at least a portion of the second outer surface) may have an Ra value selected from the range of 3.15 to 5.10 μm. In certain embodiments, the surface roughness may have an RMS value selected from the range of 153.7 to 248.6.

[0094] As mentioned above, the second outer surface may comprise a (first) portion that may be (substantially) perpendicular to the elongation axis and a (second) portion, denoted herein as "second outer surface portion", that may be inclined to the elongation axis. In particular, the latter portion may face the reflector. Thus, a portion of the second outer surface may not face the reflector and a portion of the second outer surface may face the reflector. Thus, device light that may have escaped from the system may escape via (also) the (first) portion that may be (substantially) perpendicular to the elongation axis.

[0095] As can be derived from the above, in particular embodiments, the second outer surface may comprise a rim portion configured between the outer side and the cavity. Furthermore, as described above, the rim portion may have a surface roughness as described above for the second outer surface. Furthermore, the second outer surface may further comprise a second outer surface portion configured to provide a cavity. The device light may exit the light guide element via both the rim portion and / or the second outer surface portion. The device light exiting via the rim portion may exit the system. The device light exiting via the second outer surface portion may be reflected back into the light guide element (unless there is a through hole (or opening) in the reflector). This device light may exit the light guide element via, for example, the outer side.

[0096] In certain embodiments, the light guide element comprises a rim portion. In further particular embodiments, the light guide element may not comprise a rim portion, but the reflector may comprise one or more through holes through which the device light can escape and thus not be reflected (back into the light guide element). In certain embodiments, the light guide element comprises a rim portion and the reflector may comprise one or more through holes.

[0097] Therefore, if the reflector comprises one or more through holes, the device light propagated to the second outer surface portion may not be reflected at the through holes and may propagate further out of the system. Thus, in an embodiment, the reflector may be configured such that a portion of the device light propagated to the second outer surface portion is reflected, and the reflector may be configured such that a (different) portion of the device light propagated to the second outer surface portion is not reflected by the reflector but may propagate further via the through holes in the reflector. Note that the through holes are optional.

[0098] Advantageously, a substantial part of the second outer surface may be blocked by the reflector. The unblocked part may be selected from the rim and the part upstream of the reflector opening (or through hole). The reflector may therefore be provided with a surface, in particular a conical surface, which may be fully reflective or may further comprise one or more through holes. In particular, in an embodiment, it may be true that for (approximately) 3-33%, such as in the range of 5-25%, 10-25%, of the surface area of ​​the second outer surface, the normal to the second outer surface does not intersect with the reflector surface of the reflector. This 3-33% of the surface area may be defined by the rim part and the surface of the second outer surface that is (directly) upstream of the reflector opening.

[0099] Since the second end is not completely blocked by the reflector, some of the system light can exit the system substantially parallel to the elongation axis, thus obtaining a (better) Lambertian type light distribution.

[0100] Therefore, the device light that exits the system may exit the light guide element through the outer side surface and / or through one or more of (i) the rim portion and (ii) the second outer surface portion when the (direct) downstream is the through hole of the reflector. In an embodiment, the reflector may comprise a single through hole (where the extension axes intersect). Thus, in an embodiment, one or more of the following may apply: (i) the reflector comprises one or more through holes, (ii) the second outer surface comprises a rim portion configured between the outer side surface and the cavity. In particular, in an embodiment, the rim portion may circumferentially surround the reflector. Further, in particular, the rim portion may have the surface roughness shown herein (for example, in particular, the rim portion having an Ra value selected from the range of 2.03 to 6.30 μm).

[0101] The terms "upstream" and "downstream" relate to the arrangement of an article or feature with respect to the propagation of light from a light generating means (in particular, a light source herein), and with respect to a first position within the light beam from the light generating means, a second position closer to the light generating means within the light beam is "upstream", and a third position farther from the light generating means within the light beam is "downstream".

[0102] In an embodiment, the rim portion may circumferentially surround the reflector. In an embodiment, the reflector may have a reflector radius r r In particular, in an embodiment where the system comprises a rim portion, the reflector radius (r r ) may be smaller than the (radial) distance (d1). Therefore, in an embodiment, r r < d1. For example, in an embodiment, r r ≦ 0.99 × d1. In a particular embodiment, 0.8 × d1 ≦ r r ≦ 0.99 × d1, more specifically 0.85 × d1 ≦ r r ≦ 0.99 × d1, even more specifically 0.9 × d1 ≦ r r ≦ 0.98 × d1, for example 0.95 × d1 ≦ r r ≦ 0.98 × d1. In an embodiment, the rim portion may have an outer radius r ro that is essentially the same as the distance (d1). In an embodiment, rro = d1. Furthermore, in an embodiment, the rim portion has an inner radius r ri In certain embodiments, the inner radius r of the rim portion ri may be essentially the same as the outer radius of the reflector. Therefore, in an embodiment, r ri ≒r r In an embodiment, 0.9≦r r / r ri ≦1.0, and more specifically, 0.95≦r r / r ri ≦1.0, for example in embodiments, about 0.98≦r r / r ri ≦1.0. Thus, in certain embodiments, about 0.8×d≦r ri ≦0.99×d1, more specifically, about 0.85×d1≦r ri ≦0.99×d1, more specifically, about 0.9×d1≦r ri ≦0.98×d1, for example, about 0.95×d1≦r ri ≦0.98×d1.

[0103] In certain embodiments, the reflector may comprise one or more through holes. In embodiments, the reflector may comprise a single through hole in the center of the reflector. Alternatively, the reflector may comprise two or more through holes. Thus, in embodiments, a reflector element may be provided that comprises a main reflective portion, which may be an essentially continuous portion, with one or more through holes. The percentage of the cross-sectional area of ​​the through holes relative to the area defined by the reflective portion and the cross-sectional area of ​​the through holes may range from 0 to 25%, for example in certain embodiments greater than 0% and up to 25% (0 percent indicating that there are in fact no through holes), for example in the range of 2 to 25%.

[0104] The reflector may in an embodiment be provided as a reflective coating on a surface of the cavity. In an alternative embodiment, a body including the reflector may be arranged within the cavity. In a particular embodiment, the body may be a cone having a reflective surface. As mentioned above, in an embodiment, the reflector and the cavity may be arranged in a male-female configuration. The reflector may in an embodiment be a polymer body, the part of which directed towards the cavity has a diffuse reflective surface. For example, a white polymer body may be used as the reflector, such as a white polymer body having a conical shape. The reflector may therefore have a conical shape.

[0105] In certain embodiments, the cavity (reflector cavity) may have a cavity surface facing the reflector, with at least a portion of the cavity surface not in optical contact with the reflector. In particular, the second outer surface portion may comprise a cavity surface. In other embodiments, the second outer surface portion may essentially consist of the cavity surface. As mentioned above, the cavity surface may be inclined. The inclination angle may be selected from the range of 20 to 70°, for example from the range of 27.5 to 42.5°.

[0106] In a particular embodiment, the reflector may have a cone angle (α) selected from the range of 40-140°, even more specifically selected from the range of about 55-85°. Even more specifically, the cone angle may be selected from the range of 70-75°, for example about 72.5°. Simulation results show that such an angle provides the best results in terms of outcoupling and spatial power distribution. As mentioned above, the cavity may also have a conical shape, which allows the reflector and the cavity to form an essentially male-female configuration. In particular, the reflector and the reflector cavity may have a substantially corresponding shape.

[0107] When elements are in optical contact or optically coupled, they may in embodiments be in physical contact with each other, or in other embodiments may be separated from each other by a (thin) layer of optical material, such as an optical adhesive or other optically transparent interface material, for example with a thickness of less than about 1 mm, preferably less than 100 μm. If no optically transparent interface material is applied, the (average) distance between two elements in optical contact may be approximately at a maximum, in particular at a wavelength of interest, such as the wavelength of the emission maximum. For visible wavelengths, this may be less than 1 μm, such as less than 0.7 μm, and for blue, it may be even smaller. Therefore, if optical coupling is desired, an optically transparent interface material may be applied. In yet other embodiments, if no optically transparent interface material is applied, the average distance between two elements in optical contact may be approximately at a maximum, in particular at a wavelength of interest, such as the wavelength of the emission maximum. Therefore, if optical contact is desired, physical contact may be present.

[0108] For example, the reflector may be physically coupled to a portion of the rim, which allows for reduced or no (physical) contact with the cavity. Alternatively or additionally, the reflector may only partially physically contact the cavity. For example, less than 50% of the cavity's surface, such as less than 10%, and even more specifically less than about 1%, may be in physical contact with the reflector. For example, the reflector may have an uneven surface and / or may include distance keepers. In certain embodiments, less than 50% of the cavity's surface, such as less than 10%, and even more specifically less than about 1%, may be in optical contact with the reflector.

[0109] At least a part of the device light that enters the light guide element through the first outer surface can propagate to the second outer surface, optionally through one or more (internal) reflections. A part of the device light that reaches the second outer surface can exit from the second outer surface (particularly from the rim portion (if available)). This device light may in particular be included in the system light, as may the device light that exits from the external side surface. A part of the device light that reaches the second outer surface may be further reflected by the second outer surface depending on the angle with the second outer surface. A part of the device light that reaches the second outer surface may be further reflected by a reflector. At least a part of the light reflected by the reflector may be incoupled (back) to the light guide element through the second outer surface (e.g., particularly the second outer surface portion). If the reflector is not in optical contact with the second outer surface, more particularly the second outer surface portion, the device light may exit the light guide element through the second outer surface portion, be reflected by the reflector, and thereby propagate back to the second outer surface portion and re-enter the light guide element.

[0110] Thus, at least a portion of the device light that enters the light guide element via the first outer surface can propagate to the second outer surface, optionally via one or more (internal) reflections, and exit the light guide element via the second outer surface. Alternatively, but particularly additionally, at least a portion of the device light that enters the light guide element via the first outer surface can propagate to the outer side, optionally via one or more (internal) reflections, and exit the light guide element via the second outer surface.

[0111] As can be derived from the above, in an embodiment, the light-transmitting body may have a cylindrical shape. In particular, the (radial) distance (d1) may be selected in the range of 6 to 10 mm. Furthermore, the reflector may have a conical shape with a conical tip pointing towards the first end.

[0112] Thus, in certain embodiments, the reflector may be configured to reflect a portion of the device light propagated to the second outer surface portion back into the light guide element.

[0113] In an embodiment, the light-generating system may comprise a support, such as a PCB. In an embodiment, the support may be configured to support one or more light-generating devices. Furthermore, the light-generating system may comprise a light guide element assembly ("assembly"). In an embodiment, the light guide assembly may comprise a light guide element and a light guide element base. The latter may be operatively coupled to the light guide element. In particular, the light guide element and the light guide element base may be monolithic bodies and may be provided, for example, by casting, injection molding or 3D printing a light-transmitting polymer material. The surface roughness may be provided after casting or 3D printing. In particular, the assembly may be provided by injection molding. The light guide element base may comprise a base cavity. The one or more light-generating devices may be at least partially configured in the base cavity. The cavity may therefore be defined by the light guide assembly and the support. In particular, the light guide element may be operatively coupled to the support via the light guide element base. This coupling may be a physical coupling, for example by a clamping element. Thus, in particular, in an embodiment the light-generating system may comprise a support, the support configured to support one or more light-generating devices, the light-generating system further comprising a light guide element assembly, the light guide element comprising a light guide element and a light guide element base operatively coupled to the light guide element, the light guide element base comprising a base cavity, the one or more light-generating devices being at least partially configured within the base cavity, and the light guide element operatively coupled to the support via the light guide element base.

[0114] As mentioned above, the light generating system may further comprise a light-transmitting envelope (see also above). The light-transmitting envelope may have an envelope center, the second end (of the light guide element) may be closer to the envelope center than the first end, and the second distance (d2) from the second end to the envelope center, determined from the first end, may be selected from the range of about -20 mm to +25 mm, more specifically from the range of -10 mm to +15 mm. Even more specifically, the second distance (d2) from the second end to the envelope center may be selected from the range of about +1 mm to +10 mm, for example, more specifically from the range of +2 mm to +8 mm, for example about +5 mm.

[0115] The lamp may have a lamp base to which the light guide element and / or the envelope may be operatively coupled. The lamp base may comprise electronics such as a driver. The lamp base may also comprise one or more electrical connectors for operative coupling to a power source. For example, the lamp base may comprise a screw base. Thus, the outline of at least a portion of the light generating system may be essentially defined by the lamp base and the envelope.

[0116] Any distance between the envelope center and the lamp base, as viewed from the lamp base, can be indicated by a negative value. Thus, a value of -10 mm means that, as viewed from the lamp base, the envelope center is 10 mm further from the lamp base than the second end. A value of 0 mm means that the second end is essentially at the envelope center. However, a value of +15 mm means that, as viewed from the lamp base, the envelope center is 15 mm closer to the lamp base than the second end, which extends 15 mm from the envelope center. The envelope center can be the geometric center of the envelope.

[0117] As used herein, the term "operably coupled" may refer, in embodiments, to a physical or mechanical connection between at least two elements, for example, via one or more of screws, solder, adhesives, fusion connections, click connections, and the like. The terms "physical connection" and "mechanical connection" may be used interchangeably herein. Thus, the terms "physical connection" and "mechanical connection" may also refer to adhesive connections. Alternatively or in addition, the term "operably coupled" may refer, in embodiments, to a conductive connection between at least two connections. When two (or more) elements have a conductive connection, there is at least 1×10 5 S / m, e.g. at least 1×10 6 In general, a conductive connection will exist between two (or more) elements, each of which comprises a conductive material, and which may be in physical contact with each other or may have a conductive material arranged between them. In this specification, the conductivity of an insulating material is specifically defined as being greater than or equal to 1×10 -10 S / m or less, especially 1×10 -13 In this specification, the ratio of the electrical conductivity of an insulating material (insulator) to the electrical conductivity of a conductive material (conductor) may be, in particular, 1×10 -15 In certain embodiments, the functional coupling may include coupling via wireless communication, such as via Wi-Fi or Bluetooth or LiFi.

[0118] In particular, the light-generating device may comprise one or more devices that allow control of the spectral power distribution of the device light. For example, the color point of the device may be controllable, and / or the color rendering index may be controllable, and / or the correlated color temperature may be controllable. In this way, the spectral power distribution of the light exiting the system, i.e. the system light, may be controllable. In certain embodiments, the one or more light-generating devices comprise one or more of an RGB light source, an RGBW light source, and an RYB light source, where R stands for red, G stands for green, B stands for blue, W stands for white, and Y stands for yellow.

[0119] In an embodiment, the one or more light generating devices comprise at least two different types of white-emitting light generating devices, for example configured to generate warm white light and cold white light, respectively, for example one or more light generating devices configured to generate device light with a CCT of up to 2700K and one or more light generating devices configured to generate device light with a CCT of at least 4500K, for example at least about 5500K. Alternatively, the one or more light generating devices may comprise one or more red light generating devices, one or more green light generating devices, and one or more blue light generating devices. In particular, the one or more light generating devices comprise one or more warm white light generating devices (particularly with a CCT of up to 2700K), one or more cool white light generating devices (particularly with a CCT of at least 4500K), one or more red light generating devices, one or more green light generating devices, and one or more blue light generating devices.

[0120] The term "purple light" or "purple emission" particularly relates to light having a wavelength in the range of about 380-440 nm. The term "blue light" or "blue emission" particularly relates to light having a wavelength in the range of about 440-495 nm (including some purple and cyan hues). The term "green light" or "green emission" particularly relates to light having a wavelength in the range of about 495-570 nm. The term "yellow light" or "yellow emission" particularly relates to light having a wavelength in the range of about 570-590 nm. The term "orange light" or "orange emission" particularly relates to light having a wavelength in the range of about 590-620 nm. The term "red light" or "red emission" particularly relates to light having a wavelength in the range of about 620-780 nm. The term "pink light" or "pink emission" refers to light having a blue component and a red component. The term "cyan" may refer to one or more wavelengths selected from the range of about 490-520 nm. The term "amber" may refer to one or more wavelengths selected from the range of about 585-605 nm, such as about 590-600 nm. The phrase "light having one or more wavelengths in a wavelength range" and similar phrases may specifically indicate that the indicated light (or radiation) has a spectral power distribution that has at least an intensity at one or more of the wavelengths in the indicated wavelength range. For example, a blue-emitting solid-state light source will have a spectral power distribution that has an intensity at one or more wavelengths in the wavelength range of 440-495 nm.

[0121] The terms "visible", "visible light", or "visible emission", and similar terms refer to light having one or more wavelengths in the range of about 380 to 780 nm. As used herein, UV may specifically refer to wavelengths selected from the range of 190 to 380 nm, e.g., 200 to 380 nm.

[0122] The terms "light" and "radiation" are used interchangeably herein, unless it is clear from the context that the term "light" refers only to visible light. Thus, the terms "light" and "radiation" may refer to UV radiation, visible light, and IR radiation. In certain embodiments, particularly those relating to lighting applications, the terms "light" and "radiation" refer to (at least) visible light.

[0123] Thus, in an embodiment, the system may further comprise a control system configured to control the spectral power distribution of the device light.

[0124] The term "controlling" and similar terms in particular refer to at least determining the behavior of an element or managing the operation of an element. Thus, in this specification, "controlling" and similar terms may refer to, for example, imposing a behavior on an element, such as, for example, measuring, indicating, activating, opening, transitioning, changing temperature, etc. (determining the behavior of an element or managing the operation of an element). Alternatively, the term "controlling" and similar terms may further include monitoring. Thus, the term "controlling" and similar terms may include imposing a behavior on an element, as well as imposing a behavior on an element and monitoring the element. Controlling an element can be performed by a control system, which may also be denoted as a "controller". Thus, the control system and the element may be functionally coupled, at least temporarily or permanently. The element may include the control system. In an embodiment, the control system and the element may not be physically coupled. Control can be performed via wired control and / or wireless control. The term "control system" may also refer to multiple different control systems that are specifically functionally coupled, of which, for example, one control system may be a master control system and one or more other control systems may be slave control systems. A control system may include a user interface or be functionally coupled to a user interface.

[0125] The control system may also be configured to receive and execute instructions from a remote controller. In an embodiment, the control system may be controlled via an app on a device, such as a portable device, such as a smartphone or I-phone, tablet, etc. Hence, the device is not necessarily coupled to the lighting system, but may be (temporarily) functionally coupled to the lighting system.

[0126] Therefore, in an embodiment, the control system may (also) be configured to be controlled by an app on a remote device. In such an embodiment, the control system of the lighting system may be a slave control system or may control in a slave mode. For example, the lighting system may be identifiable by a code, in particular a unique code for the corresponding lighting system. The control system of the lighting system may be configured to be controlled by an external control system that has access to the lighting system based on knowledge of the (unique) code (entered by a user interface of an optical sensor (e.g. a QR code reader)). The lighting system may also comprise means for communicating with other systems or devices, such as based on Bluetooth, WIFI, LiFi, ZigBee, BLE or WiMAX, or another wireless technology.

[0127] A system, or an apparatus, or a device may perform an action in a "mode" or "operation mode". The term "operation mode" may also be indicated as a "control mode". Similarly, in a method, an action, or a stage, or a step may be performed in a "mode" or "operation mode". This does not exclude that the system, or an apparatus, or a device may also be adapted to provide another control mode or multiple other control modes. Similarly, this may not exclude that one or more other modes may be performed before and / or after performing a mode.

[0128] However, in embodiments, a control system may be available that is adapted to provide at least the control mode. If other modes are available, the selection of such modes may in particular be performed via a user interface, although other options may also be possible, such as executing the mode depending on a sensor signal or a (time) scheme. An operating mode may also refer in embodiments to a system, or an apparatus, or a device that can only operate in a single operating mode (i.e., "on", without further adjustability).

[0129] Thus, in an embodiment, the control system may be responsive to one or more of a user interface input signal, a sensor signal (of a sensor), and a timer, where the term "timer" may refer to a clock and / or a predefined time scheme.

[0130] In certain embodiments, the light-generating system may be configured to generate a white system light that includes at least a portion of the device light that escapes the light guide element through the external side and through the second external surface, e.g., through the second external surface portion if the reflector has one or more through holes, and / or through the rim portion. In particular, the system light may have one or more of a controllable color rendering index and a controllable correlated color temperature. In other embodiments, the system may be configured to generate colored light. Thus, the system may be operated in different operating modes, e.g., one or more operating modes using (different types of) white light and one or more operating modes using (different types of) colored light.

[0131] The term "white light" in this specification is known to those skilled in the art. White light particularly relates to light having a correlated color temperature (CCT) in the range of about 1800K to 20000K, such as 2000 to 20000K, particularly 2700 to 20000K, and particularly for general lighting, about 2700K to 6500K. In embodiments, for backlighting purposes, the correlated color temperature (CCT) may particularly be in the range of about 7000K to 20000K. Furthermore, in embodiments, the correlated color temperature (CCT) is particularly within about 15 SDCM (standard deviation of color matching) from the black body locus (BBL), particularly within about 10 SDCM from the BBL, and even more particularly within about 5 SDCM from the BBL.

[0132] The light generating system may be part of or applied to, for example, an office lighting system, a home application system, a store lighting system, a domestic lighting system, an accent lighting system, a spot lighting system, a theater lighting system, a fiber optic application system, a projection system, a self-illuminated display system, a pixelated display system, a segmented display system, a warning sign system, a medical lighting application system, an indicator sign system, a decorative lighting system, a portable system, an automotive application, an (outdoor) road lighting system, an urban lighting system, a greenhouse lighting system, a horticultural lighting, a digital projection, or an LCD backlight. The light generating system (or luminaire) may be part of or applied to, for example, an optical communication system or a disinfection system.

[0133] In yet a further aspect, the present invention also provides a lamp or luminaire comprising a light-generating system as defined herein. The luminaire may further comprise a housing, optical elements, louvers, etc. The lamp or luminaire may further comprise a housing enclosing the light-generating system. The lamp or luminaire may comprise an optical window in the housing, or a housing opening, through which the system light may escape the housing. In yet a further aspect, the present invention also provides a projection device comprising a light-generating system as defined herein. In particular, a projection device or "projector" or "image projector" may be an optical device that projects an image (or a moving image) onto a surface, such as a projection screen. The projection device may include one or more light-generating systems as described herein. Thus, in one aspect, the present invention also provides an illumination device selected from the group of lamps, luminaires, projector devices, disinfection devices, photochemical reactors, and optical wireless communication devices, comprising a light-generating system as defined herein. The illumination device may comprise a housing or support configured to accommodate or support one or more elements of the light-generating system. For example, in embodiments, the lighting device may comprise a housing or support configured to accommodate or support one or more of the light guide elements and one or more light generating devices, In certain embodiments, the lighting device may have the shape of a retrofit lamp.

[0134] The terms "light" and "radiation" are used interchangeably herein, unless it is clear from the context that the term "light" refers only to visible light. Thus, the terms "light" and "radiation" can refer to UV radiation, visible light, and IR radiation. In certain embodiments, particularly those relating to lighting applications, the terms "light" and "radiation" refer to visible light.

[0135] Accordingly, in particular, the present invention provides a light generation system comprising one or more light generation devices, a light guiding element, a reflector, and an optional light transmissive enclosure, wherein: (A) the one or more light generation devices are configured to generate device light; (B) the light guiding element comprises a light transmissive body comprising a light transmissive material that is light transmissive to the device light, the light transmissive body comprising an elongation axis and a body length (L1), the light transmissive body comprising a first end and a second end, the light transmissive body comprising: (i) a first outer surface included at the first end; (ii) a second outer surface included at the second end; and (iii) an outer side surface having a distance (d1) connecting the first outer surface and the second outer surface to the elongation axis, where d1 < L1, and the second outer surface portion of the second outer surface is configured to provide a cavity for accommodating at least a portion of the reflector; (C) the reflector is a diffusive reflector for the device light, and at least a portion of the reflector is configured within at least a portion of the cavity; (D) the one or more light generation devices, the light guiding element, and the reflector are configured such that: (i) at least a portion of the device light is incoupled into the light guiding element through the first outer surface; (ii) at least a portion of the incoupled device light exits the light guiding element through the outer side surface and through the second outer surface, for example through the second outer surface portion (and / or rim portion); and (iii) at least a portion of the device light propagated to the second outer surface portion is reflected by the reflector; and (E) at least a portion of the light guiding element is configured within an optional light transmissive enclosure, the light transmissive enclosure being transmissive to at least a portion of the device light.

Brief Description of the Drawings

[0136] Here, embodiments of the present invention are described by way of example only with reference to the accompanying schematic drawings, in which corresponding reference numerals indicate corresponding parts.

[0137] [Figure 1A] Embodiments and aspects of system 1000 are schematically illustrated. [Figure 1B] Embodiments and aspects of system 1000 are schematically illustrated. [Figure 1C]1 illustrates generally embodiments and aspects of a system 1000. [Figure 1D] 1 illustrates generally embodiments and aspects of a system 1000. [Figure 1E] 1 illustrates generally embodiments and aspects of a system 1000. [Figure 1F] 1 illustrates generally embodiments and aspects of a system 1000. [Figure 1G] 1 illustrates generally embodiments and aspects of a system 1000. [Figure 1H] 1 illustrates generally embodiments and aspects of a system 1000. [Figure 1I] 1 illustrates generally embodiments and aspects of a system 1000. [Figure 1J] 1 illustrates generally embodiments and aspects of a system 1000. [Diagram 2] 1 illustrates a simulated light distribution for one embodiment of the system. [Diagram 3] Some further embodiments and aspects are illustrated diagrammatically.

[0138] The schematic drawings are not necessarily to scale. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0139] 1A-1J, there are shown embodiments and aspects of a system 1000. In particular, FIG. 1A illustrates generally one embodiment of a light-generating system 1000 comprising one or more light-generating devices 100, a light guide element 500, and a reflector 410.

[0140] One or more light-generating devices 100 may be configured to generate device light 101, where the one or more light-generating devices 100 comprise diode-based light sources.

[0141] The light guide element 500 may include a light transmissive body 510 that includes a light transmissive material 502 that may be light transmissive with respect to the device light 101. The light transmissive body 510 may include an elongation axis 501 and a body length L1 defined parallel to the elongation axis 501. The light transmissive body 510 may include a first end portion 511 and a second end portion 512 that define the body length L1. The light transmissive body 510 may include (i) a first outer surface 521 included in the first end portion 511, (ii) a second outer surface 522 included in the second end portion 512, and (iii) an outer side surface 523 having a (radial) distance d1 connecting the distance between the first outer surface 521 and the second outer surface 521 to the elongation axis 501. Therefore, d1 may refer to a radius in embodiments. In particular, d1 < L1. The first outer surface 521, the second outer surface 522, and the outer side surface 523 may define at least a part of the outer surface of the light transmissive body 510. In an embodiment, a second outer surface portion 524 of the second outer surface 522 may be configured to provide a cavity 530 for accommodating at least a part of the reflector 410.

[0142] The reflector 410 may be a diffusive reflector for the device light 101. In particular, at least a part of the reflector 410 may be configured within at least a part of the cavity 530.

[0143] One or more light generating devices 100, the light guide element 500, and the reflector 410 may be configured such that at least a part of the device light 101 can be incoupled into the light guide element 500 through the first outer surface 521, and at least a part of the incoupled device light 101 can exit the light guide element 500 through the outer side surface 523 and / or through the second outer surface portion 524, particularly through both of them. In an embodiment, the reflector 410 may reflect a part of the device light 101 propagated to the second outer surface portion 524, and a part of the device light 101 propagated to the second outer surface portion 524 may be propagated away from the light guide element 500 in a direction having a component parallel to the elongation axis 501.

[0144] In an embodiment, at least a portion of the device light 101 propagated to the second outer surface portion 524 may be reflected by the reflector 410. In an embodiment, a range of 2 to 15% of the device light 101 exiting the light generation system 1000 may exit within a (virtual) cone having the elongation axis 501 as the cone axis, and the cone may have a cone angle θ2 selected from a range of 20 to 40°. For example, a range of 2 to 15% of the device light 101 exiting the light generation system 1000 may exit within a (virtual) cone having the elongation axis 501 as the cone axis, and the cone may have a cone angle θ2 of 30°. The reference θ1 may be a half cone angle.

[0145] In an embodiment, at least a portion of the external side 523 has a surface roughness to facilitate outcoupling of the device light 101 from the optically transparent body 510 via the external side 523. In particular, in an embodiment, the surface roughness may have an Ra value selected from the range of 0.16 to 0.64 μm, more specifically 0.32 to 0.5 μm, and / or an RMS value selected from the range of 7.90 to 31.30, more specifically 15.8 to 24.5.

[0146] 1B and 1C, in certain embodiments, at least a portion of exterior side 523 may be provided with a sinusoidal shape. In particular, in embodiments, edge 527 defined by exterior side 523 and second outer surface 522 may comprise a sinusoidal shape.

[0147] 1E , in an embodiment, at least a portion of second outer surface 522 may have a surface roughness to facilitate outcoupling of device light 101 from optically transparent body 510 via second outer surface 522. In an embodiment, the surface roughness may have an Ra value selected from the range of 2.03 to 6.30 μm, more specifically 3.15 to 5.10 μm, and / or an RMS value selected from the range of 98.90 to 306.20, more specifically 153.7 to 248.6.

[0148] 1E, the rim portion 525 may circumferentially surround the reflector 410. In an embodiment, the reflector 410 has a reflector radius r r The reflector radius r r may be smaller than the (radial) distance d1. For example, in an embodiment, r r ≦0.99×d1. In certain embodiments, 0.8×d1≦r r ≦0.99×d1, more specifically 0.85×d1≦r r ≦0.99×d1, more specifically, 0.9×d1≦r r ≦0.98×d1, for example, 0.95×d1≦r r ≦0.98×d1. In an embodiment, the rim portion 525 has an outer radius r ro In an embodiment, r ro = d1. Further, in an embodiment, the rim portion 525 has an inner radius r ri In certain embodiments, the inner radius r of the rim portion ri may be essentially the same as the outer radius of the reflector. Therefore, in an embodiment, r ri ≒r r In an embodiment, 0.9≦r r / r ri ≦1.0, and more specifically, 0.95≦r r / r ri ≦1.0, for example in embodiments, about 0.98≦r r / r ri ≦1.0. Thus, in certain embodiments, about 0.8×d≦r ri ≦0.99×d1, more specifically, about 0.85×d1≦r ri ≦0.99×d1, more specifically, about 0.9×d1≦r ri ≦0.98×d1, for example, about 0.95×d1≦r ri ≦0.98×d1. Such dimensions of the rim portion may cause at least a portion of the device light to propagate essentially parallel to the elongation axis. The small dimensions and / or surface roughness of the rim portion may reduce or even prevent direct viewing (through the light guide element) of one or more light-generating devices upstream of the first outer surface.

[0149] 1D, 1F, and 1G in particular, in embodiments it may be true that for 3-33% of the surface area of ​​second outer surface 522, the normal to second outer surface 522 does not intersect with the reflector surface of reflector 410. In Figures 1B and 1E, some of the dashed lines indicate normal N. The small rectangle at the bottom of normal N indicates how normal N is 90° to the surface on which it lies.

[0150] With reference to Figures 1F-1G, in certain embodiments, the reflector 410 may comprise one or more through holes 415. In Figure 1F, embodiments I and IV comprise a solid light-transmitting body with a reflector 412, for example a coating. In embodiment I, the body does not even need to be light-transmitting, since there is not a through hole 415 in the reflector as in embodiment IV. In embodiments II and III, hollow reflectors are shown diagrammatically. The hollow reflectors are shown diagrammatically to comprise one or more through holes 415. In embodiment II, the reflector may comprise a single through hole (crossed by the extension axis 501). It should be noted that the reflector 410 may not have a through hole. In such embodiments, the light guide element may in particular comprise a rim portion. Figure 1G diagrammatically shows a bottom view of the reflector diagrammatically shown in Figure 1F. 1H shows several top views of the light guide element 500 with a reflector 410 arranged in a cavity, in which embodiments I, II, and IV have a rim portion 525, and embodiments III and V have no rim portion. Furthermore, embodiments II, III, IV, and V all have one or more through holes 415 in the reflector. Therefore, in any of these embodiments, the second outer surface 522 is completely blocked by the reflector 410, and a portion of the device light can escape from the light guide element 500 parallel to the elongation axis. Therefore, in the embodiments, one or more of the following may apply: (i) the reflector 410 comprises one or more through holes 415, (ii) the second outer surface 522 comprises a rim portion 525 arranged between the outer side surface 523 and the cavity 530.

[0151] 1A-1B and 1D-1E in particular, in an embodiment, the second exterior surface 522 may include a rim portion 525 configured between the exterior side 523 and the cavity 530. In still further particular embodiments, the rim portion 525 may have a surface roughness, with an Ra value selected from the range of 2.03-6.30 μm, more specifically 3.15-5.10 μm, and / or an RMS value selected from the range of 98.90-306.20, more specifically 153.7-248.6.

[0152] Thus, the light guide element 500 may be essentially completely transparent, except for the exterior side 523, which may have a surface roughness that renders the surface opaque, and except for at least a portion of the second exterior surface 522, particularly the rim 525, which may also have a surface roughness that renders the surface opaque.

[0153] In an embodiment, the reflector 410 may be configured to reflect a portion of the device light 101 propagated to the second outer surface portion 524 back into the light guide element 500 (via the second outer surface portion 524).

[0154] In embodiments, the one or more light generating devices may comprise one or more of a light emitting diode, a diode laser, and a superluminescent diode.

[0155] 1C-1D, for example, in an embodiment, the light-transmitting body 510 has a cylindrical shape. In particular, in an embodiment, the (radial) distance d1 may be selected from the range of 6-10 mm. In FIG. 1C (top view), the external side 523 comprises a repeating structure. In FIG. 1D, by way of example, this repeating structure is not available. In both embodiments, the external side 523 may have a surface roughness as described herein.

[0156] Furthermore, in an embodiment, the reflector 410 may have a conical shape with the cone tip 412 pointing towards the first end 511. In an embodiment, the reflector 410 may have a cone angle α selected from the range of 55 to 85°.

[0157] In an embodiment, the cavity 530 may have a reflector 410 facing a cavity surface 531, at least a portion of which may not be in optical contact with the reflector 410. In an embodiment, the reflector 410 may have a reflector surface 411 facing the optically transparent body.

[0158] 1A , due in part to the surface roughness of the side surfaces, a majority of the light 101 can exit the light guide through surface 523. However, a significant portion of the light 101 will be reflected by TIR at surface 524 and then exit the light guide through surface 523. A significant portion of the light 101 will also pass through surface 524 and be reflected back into the light guide element through reflector 410, and a significant portion of this light can exit the light guide element, also at surface 523.

[0159] 1I, the system 1000 may further comprise a light-transmitting envelope 600. In particular, at least a part of the light guide element 500 may be configured within the light-transmitting envelope 600. In particular, the light-transmitting envelope 600 may be transparent to at least a part of the device light 101. Thus, the outline of at least a part of the light-generating system may essentially be defined by the lamp base and the envelope.

[0160] Light exiting the system 1000 is shown as system light 1001 and may include, or more specifically consist essentially of, the device light 101 (exiting the light guide element 500).

[0161] In an embodiment, the optically transparent envelope 600 has an envelope center 601. In particular, in an embodiment, the second end 512 may be closer to the envelope center 601 than the first end 511. In certain embodiments, a second distance d2 from the second end 512 to the envelope center 601, as determined from the first end 511, may be selected from a range of −10 mm to +15 mm.

[0162] The light-generation system 1000 may further comprise a control system 300. The control system 300 may be configured to control the spectral power distribution of the device light 101.

[0163] In an embodiment, the one or more light generating devices comprise one or more of an RGB light source, an RGBW light source, and an RYB light source.

[0164] In certain embodiments, the light generating system 1000 may be configured to generate a white system light 1001 that includes at least a portion of the device light 101 exiting the light guide element 500 through the exterior side 523 and through the second exterior portion 524. In further embodiments, the system light 1001 has one or more of a controllable color rendering index and a controllable correlated color temperature.

[0165] FIG. 1J shows a schematic representation of an embodiment of a support 600 configured to support one or more light-generating devices 100. Additionally, a schematic representation of an embodiment of a light guide element assembly 550 is shown. In an embodiment, the light guide assembly 550 may comprise a light guide element 500 and a light guide element base 560 operatively coupled to the light guide element 500. In particular, the light guide element base 560 may comprise a base cavity 562 in which one or more light-generating devices 100 are at least partially configured. The light guide element 500 may be operatively coupled to the support 600 via the light guide element base 560. Reference number 610 refers to a support hole. Reference number 561 refers to a part of the assembly that may penetrate the support 600. This may facilitate the operative coupling between the light guide element base 560 and the support. The light guide element base 560 may be referred to as a "light guide element base". The base cavity may be referred to as a "foot cavity". Further elements may be provided to enable a functional coupling: Reference number 620 refers to a fastening element, e.g. a clamping element, that can associate the light guide element 500 (via the light guide element base 560) with the support 600.

[0166] 2 shows a simulated light distribution of one embodiment of the system. As shown, the distribution may be substantially Lambertian.

[0167] In one embodiment, the light guide element may have a length L1 of about 60 mm and a diameter of about 17 mm. The diameter of the reflector is about 15. The reflector has a conical shape with an apex angle or cone angle of about 72°.

[0168] Fig. 3 shows a schematic representation of an embodiment of a luminaire 2 comprising a light-generating system 1000 as described above. Reference number 301 indicates a user interface, which may be functionally coupled to a control system 300 included by or functionally coupled to the light-generating system 1000. Fig. 3 also shows a schematic representation of an embodiment of a lamp 1 comprising the light-generating system 1000. Reference number 3 indicates a projector device or projector system, which may be used to project an image on a wall or the like, which may also comprise the light-generating system 1000. Thus, Fig. 3 shows a schematic representation of an embodiment of a lighting device 1200 selected from the group of lamps 1, luminaires 2, projector devices 3, disinfection devices, photochemical reactors and optical wireless communication devices, comprising the light-generating system 1000 as described herein. In an embodiment, such lighting devices may be lamps 1, luminaires 2, projector devices 3, disinfection devices or optical wireless communication devices. The lighting device light exiting the lighting device 1200 is indicated with reference number 1201. The illumination device light 1201 may consist essentially of the system light 1001, and therefore may be the system light 1001 in certain embodiments.

[0169] The term "plurality" refers to two or more.

[0170] The terms "substantially" or "essentially" and similar terms herein will be understood by those skilled in the art. The terms "substantially" or "essentially" may also include embodiments with "entirely", "completely", "all", etc. Thus, in embodiments, the adjectives substantially or essentially may also be omitted. Where applicable, the terms "substantially" or "essentially" may also relate to 90% or more, including 100%, such as 95% or more, particularly 99% or more, and even more particularly 99.5% or more.

[0171] The term "comprises" also includes embodiments where the term "comprises" means "consists of".

[0172] The term "and / or" specifically refers to one or more of the items mentioned before and after "and / or." For example, the phrase "item 1 and / or item 2" and similar phrases may refer to one or more of items 1 and 2. The term "comprising" may, in one embodiment, refer to "consisting of," but in another embodiment may also refer to "including at least the defined species, and optionally one or more other species."

[0173] Moreover, the terms first, second, third, etc., in the specification and claims are used to distinguish between similar elements and are not necessarily used to describe a sequential or chronological order, and the terms so used are interchangeable under appropriate circumstances, with it being understood that the embodiments of the invention described herein are capable of operation in other orders than those described or illustrated herein.

[0174] As used herein, a device, apparatus, or system may be described, among other things, in operation. As will be apparent to one of ordinary skill in the art, the present invention is not limited to methods of operation or to devices, apparatus, or systems in operation.

[0175] It should be noted that the above-described embodiments are illustrative rather than limiting of the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims.

[0176] In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.

[0177] Use of the verb "to comprise" and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. Unless the context clearly requires otherwise, throughout the specification and claims, the words "comprise", "comprising", and the like, are to be interpreted in an inclusive sense, i.e., "including, but not limited to", rather than an exclusive or exhaustive sense.

[0178] The article "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.

[0179] The invention may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In a device claim, or an apparatus claim, or a system claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The mere fact that certain means are recited in mutually different dependent claims does not indicate that a combination of these means cannot be used to advantage. In still a further aspect, the invention therefore provides a software product which, when executed on a computer, is capable of causing (one or more embodiments of) the method as described herein.

[0180] The present invention also provides a control system that may control a device, apparatus or system or that may perform the methods or processes described herein. Still further, the present invention also provides a computer program product that, when executed on a computer operatively coupled to or included by a device, apparatus or system, controls one or more controllable elements of such a device, apparatus or system.

[0181] The invention further applies to a device, an apparatus or a system comprising one or more of the features described in the present specification and / or shown in the accompanying drawings.The invention further relates to a method or process comprising one or more of the features described in the present specification and / or shown in the accompanying drawings.

[0182] The various aspects discussed in this patent may be combined to provide additional advantages. Moreover, those skilled in the art will appreciate that embodiments may be combined, and that three or more embodiments may be combined. Moreover, some of the features may form the basis for one or more divisional applications.

Claims

1. A light-generating system comprising one or more light-generating devices, a light guide element, a reflector, and a light-transmitting envelope, the one or more light-generating devices are configured to generate device light, the one or more light-generating devices comprising a diode-based light source; the light guide element comprises a light-transmitting body comprising a light-transmitting material that is light-transmitting to the device light, the light-transmitting body comprising an elongation axis and a body length L1 defined parallel to the elongation axis, the light-transmitting body comprising a first end and a second end defining the body length L1, the light-transmitting body comprising: (i) a first outer surface included at the first end; (ii) a second outer surface included at the second end; and (iii) an exterior side spanning a distance between the first outer surface and the second outer surface and having a distance d1 to the elongation axis, where d1<L1, the first outer surface, the second outer surface, and the exterior side define at least a portion of an exterior surface of the light-transmitting body, and a second exterior surface portion of the second outer surface configured to provide a cavity to accommodate at least a portion of the reflector; the reflector is a diffuse reflector for the device light, at least a portion of the reflector being configured within at least a portion of the cavity; The one or more light generating devices, the light guide element, and the reflector are configured such that (i) at least a portion of the device light is incoupled within the light guide element via the first outer surface, (ii) at least a portion of the incoupled device light exits the light guide element via the external side and the second outer surface, (iii) at least a portion of the device light propagated to the second outer surface portion is reflected by the reflector, and (iv) for 3-33% of a surface area of ​​the second outer surface, a normal to the second outer surface does not intersect a reflector surface of the reflector; at least a portion of the light guide element is configured within the light-transmissive envelope, the light-transmissive envelope being transmissive to at least a portion of the device light; A light production system, wherein at least a portion of the second exterior surface has a surface roughness to facilitate outcoupling of the device light from the optically transparent body through the second exterior surface.

2. 10. The light production system of claim 1, wherein at least a portion of the exterior side has a surface roughness to facilitate outcoupling of the device light from the optically transparent body through the exterior side.

3. 3. The light generation system of claim 2, wherein the surface roughness has an Ra value selected from the range of 0.16 to 0.64 μm.

4. 4. The light generation system of claim 2 or 3, wherein at least a portion of the exterior side comprises a repeating shape having a period and a distance between peaks and valleys independently selected from the range of 0.1 to 4 mm.

5. The light generating system of claim 4 , wherein an edge defined by the exterior side and the second outer surface comprises the repeating shape, the repeating shape having a sinusoidal shape.

6. The light generation system of any one of the preceding claims, wherein the surface roughness of the at least part of the second outer surface has an Ra value selected from the range of 2.03 to 6.30 μm.

7. 7. The light generation system of claim 1, wherein for 10-25% of the surface area of ​​the second outer surface, a normal to the second outer surface does not intersect the reflector surface of the reflector, and a range of 2-15% of the device light exiting the light generation system exits within a cone with the elongation axis as a cone axis, the cone having a cone angle θ2 selected from the range of 20-40°, and the reflector comprises one or more through holes.

8. 8. The light generation system of claim 1, wherein the second outer surface comprises a rim portion configured between the exterior side and the cavity.

9. 9. The light generating system of claim 1 , wherein the reflector is configured to reflect a portion of the device light propagated to the second outer surface portion back to the light guide element, and the one or more light generating devices comprise one or more of a light emitting diode, a diode laser, and a superluminescent diode.

10. 10. The light-generating system of claim 1, wherein the light-transmitting body has a cylindrical shape, the distance d1 is selected from the range of 6 to 10 mm, the reflector has a conical shape with a conical tip pointing towards the first end, the reflector has a cone angle α selected from the range of 55 to 85°, and 55 to 98% of all device light exiting the light-generating system exits the light guide element through the external side surface and 2 to 45% of all device light exiting the light-generating system exits the light guide element through the second external surface.

11. 11. The light generation system of claim 1, wherein the cavity has a cavity face facing the reflector, at least a part of the cavity face being not in optical contact with the reflector.

12. 12. The light-generating system of claim 1, further comprising a light guide element assembly comprising the light guide element and a light guide element base operatively coupled to the light guide element, the light guide element base comprising a base cavity, the one or more light-generating devices being at least partially configured within the base cavity, and the light guide element being operatively coupled to the support via the light guide element base.

13. 13. The light generating system of any one of claims 1 to 12, wherein the light-transmitting envelope has an envelope center, the second end is closer to the envelope center than the first end, and a second distance d2 from the second end to the envelope center, determined from the first end, is selected from the range of -10 mm to +15 mm.

14. 14. The light-generating system of claim 1, further comprising a control system configured to control a spectral power distribution of the device light, the one or more light-generating devices comprising one or more of an RGB light source, an RGBW light source, and an RYB light source, the light-generating system configured to generate a white system light comprising at least a portion of the device light exiting the light guide element through the external side surface and through the second external surface, the system light having one or more of a controllable color rendering index and a controllable correlated color temperature.

15. 15. An illumination device selected from the group of a lamp, a luminaire, a projector device, a disinfection device, a photochemical reactor, and an optical wireless communication device, comprising a light generating system according to any one of the preceding claims.

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