Luminaire designed as a spotlight, installation unit for converting such a luminaire, and use of such an installation unit

Abstract

A luminaire (1) designed as a spotlight, comprising a light source (9) supported by a light source holder (8) and a reflector (4) for the directed emission of light generated by the light source (9), characterized in that the luminaire (1) has a mounting unit (15) comprising the light source holder (8) and the light source (9) supported by it, wherein the light source holder (8) is arranged outside the reflector space (4) and comprises as a light source an LED light source (9) and a light guide body (10) supported by the light source holder (8) and extending into the reflector space (5), which has an input surface (12) into which light generated by the LED light source (9) is coupled when the LED light source is operated, and an output surface located within the reflector space (5) from which light is coupled out of the light guide body (10) in the direction of the reflector surface (6) of the reflector (4).

Description

The invention relates to a luminaire designed as a spotlight, comprising a light source supported by a lamp holder and a reflector for the directed emission of light generated by the light source. A further claim relates to an installation unit for converting a luminaire designed as a spotlight, comprising a reflector and a lamp holder supporting an incandescent or discharge lamp as the light source, the light source of which is arranged within the reflector space of the reflector, to LED technology. The use of such an installation unit is also described. Luminaires designed as spotlights include, for example, recessed ceiling lights or track lighting. These types of lights are frequently used to illuminate exhibits, such as in museums, galleries, and similar venues. Due to its spotlight design, the light emitted by such a luminaire is directed. For this purpose, the luminaire has a reflector. Depending on the desired beam pattern or the light pattern produced by the luminaire, the reflector can have a different shape and / or surface area. The light source, either an incandescent bulb or a discharge lamp, is located within the reflector's recess. In the former, the light is generated by a filament (incandescent bulb or halogen lamp), and in the latter, by a burner (metal halide lamp).The reflector is calculated and designed for this specific focal point of the light source. To achieve the desired illumination of an object, such luminaires are designed to be equipped with interchangeable reflectors with different beam angles, or with additional elements such as focusing or diffusing lenses, color filters, and the like. The light source holder of such a luminaire is usually located outside the reflector housing. The reflector itself has an opening through which the light source, with its connection base, passes and engages in the complementary counterpart supported by the light source holder. For energy-saving reasons, and given that incandescent and discharge lamps are no longer permitted for use in lighting applications, efforts are being made to convert such luminaires, especially high-end or premium models, to LED technology. The aim is to maintain lighting characteristics such as beam angle, uniformity, and glare control as closely as possible, ensuring that the illuminated object is lit in the same way as it was with the conventional light source.LED light sources, however, have a completely different beam pattern than conventional light sources. Therefore, to achieve the same lighting characteristics as with a conventional light source, the reflector and, if used, any additional components such as interchangeable reflectors with different beam angles, lenses, filters, and the like must be replaced with components adapted to the beam pattern of the LED light source. Thus, it is necessary to replace all the technology responsible for the lighting in such a luminaire. Only the luminaire housing and the components intended for holding or installing it can be retained.Consequently, converting halogen spotlights to LED technology while largely maintaining the existing lighting characteristics is quite expensive, especially for institutions that operate a large number of such lights and accessories, such as museums. Simply replacing the aforementioned conventional light sources with so-called retrofit lamps using LED technology does not meet the same photometric requirements as the lamp being replaced. Based on this discussed state of the art, the invention aims to propose an installation unit for converting such a luminaire designed as a spotlight, as well as a luminaire equipped with such a unit, which makes it possible to convert from operation with conventional lamps to LED technology in a more cost-effective and, above all, more resource-efficient manner. This problem is solved according to the invention by a luminaire designed as a spotlight, as mentioned above, in which the luminaire has a mounting unit comprising the lamp holder and the lamp carried by it, in which the lamp holder is arranged outside the reflector space and comprises an LED light source and a light guide body carried by the lamp holder, extending into the reflector space, which has an input surface into which light generated by the LED light source is coupled when the LED light source is operated, and an output surface located within the reflector space from which light is coupled out of the light guide body in the direction of the reflector surface of the reflector. This problem is further solved by an installation unit for converting a luminaire designed as a spotlight with conventional light source to LED technology with the features of claim 14. In this luminaire, designed as a spotlight – the same applies to the recessed version – the lamp holder, located outside the reflector's reflector chamber, houses an LED light source. This is typically a flat COB LED (Chip-on-Board LED). The LED light source is also located outside the reflector chamber. In addition to the LED light source, the lamp holder supports a light guide. This light guide protrudes into the reflector chamber. The light guide has a coupling surface into which the light generated by the LED is coupled when the luminaire, and thus the LED light source, is in operation. This coupling surface of the light guide is located either directly adjacent to or in close proximity to the light-emitting side of the LED light source.To improve the luminous efficacy of the light generated by the LED light source and coupled into the light guide, the coupling surface of the light guide can be connected to the light-emitting side of the LED light source by means of an optically conductive material, such as optically conductive silicone. The light generated by the LED light source is guided through the light guide, via the bottom opening of the reflector, into the reflector chamber. Within the reflector chamber, the light guide has an output coupling surface from which light is coupled out when the luminaire is in operation, in the direction of the reflector surface. It is not necessary for light to be coupled out of the light guide exclusively in the direction of the reflector surface in order to be reflected there in the desired direction of emission.Rather, as with conventional lamps, the output surface is typically designed so that light is coupled directly from the reflector surface without reflection and emitted in the direction of radiation. In such a light guide, which is typically rod-shaped, the output surface can be adapted to the desired radiation characteristics of the conventional lamp being replaced by the integrated unit, or it can be designed to mimic the radiation characteristics of a conventional lamp. This is typically achieved by creating light-directing structures. These light-directing structures can be light-directing surfaces or a frosted surface, and both can also be combined. In the case of a frosted surface, a multitude of miniature surfaces oriented in different spatial directions form the light-directing structures.With such a mounting unit, a luminaire designed as a spotlight, originally equipped with a conventional light source, can be converted to LED technology simply by replacing the light source holder and the light source it supports, while maintaining the lighting characteristics previously established for this luminaire, such as beam angle, uniformity, and glare control. The reflector and any additional components intended for this luminaire, such as lenses, can continue to be used. Converting a spotlight operated with a conventional light source is therefore correspondingly cost-effective and resource-efficient. By converting to LED technology, luminaires retrofitted with a mounting unit according to the invention gain the added benefit that, with a suitable LED light source design, the light color can be adjusted and, if necessary, changed.This applies to different shades of white as well as to the appropriate design of the LED light source for generating colored light. If an object is illuminated in color with the luminaire being converted, the use of color filters can generally be dispensed with after the conversion. In addition to the possibility of individually designing the output surface of the light guide body of such a built-in unit, it is also possible to influence the length of the light guide body in the direction of emission as well as the length of the section of the light guide body extending in this direction with its output surface. Regardless of whether the original lamp holder of the luminaire to be converted, which is designed as a spotlight with a conventional light source, is adjustable in the axial direction and thus in the direction of the emission relative to the reflector in order to focus the light source it carries located in the reflector space, the lamp holder of the luminaire according to the invention or the installation unit according to the invention within the luminaire housing can be adjustable in this direction in order to bring the coupling surface of the light guide element within the reflector space to the position required for the desired light emission characteristic. Typically, the light guide is made of glass. Such a light guide is then insensitive to the higher temperatures that sometimes occur during operation of the LED light source. If less heat is generated during operation of the LED light source, such a light guide can also be made of other light-conducting materials, for example, acrylic. In many cases, such a light guide will have a cylindrical outer surface, thus a circular cross-sectional area. The geometric design of the light guide's outer surface can also influence its emission characteristics and, consequently, those of the luminaire. For example, the cross-sectional geometry of the light guide can be square, polygonal, or have other outline geometries. Typically, the coupling surface of the light guide is planar and lies in the transverse plane perpendicular to the axial extent of the light guide. As light-guiding structures, the optical fiber can, for example, have a recess in its end face opposite the coupling surface. According to one embodiment, this recess is stepped to create multiple coupling surfaces, with the diameter decreasing towards the depth. Advantageously, the inner surface of this recess is frosted, which contributes to a more uniform light coupling. The outline geometry of such a recess typically corresponds to that of the outer surface of the rod-shaped optical fiber. The light guide is connected to the lamp holder. This connection can be permanent or detachable. In the latter case, if a change in the light emission characteristics is desired, the first light guide can be replaced with another featuring differently arranged or designed light-directing structures. A light guide holder typically serves to attach the light guide to the lamp holder. A detachable connection of the light guide to the lamp holder is possible, for example, by means of a circumferentially opening sleeve, which in this case serves as the light guide holder. The light source holder is preferably made of a highly thermally conductive material, which, when the LED light source is in operation, acts as a heat sink and thus dissipates the heat generated by the LED light source during operation. The light source holder extends from the back of the reflector away from it. Suitable materials include copper or aluminum alloys, with brass being the most common choice in the former case. The LED light source, for example, a flat COB LED or an array of individual LEDs, is thermally connected to the light source holder. The light source holder extends sufficiently far from the LED light source to effectively absorb and dissipate the heat generated during operation. This absorbed heat can then be radiated within the light fixture housing, which typically has ventilation openings.Connecting such a light source holder to a luminaire housing allows the housing to also be thermally connected to the light source holder, thus acting as a heat sink for efficient cooling of the LED light source. The same applies if the light source holder is connected to an inner luminaire housing that acts as a holder for the light source holder and is adjustable relative to the reflector. The invention is described below with reference to an exemplary embodiment and the accompanying figures. These show: Fig. 1: A schematic longitudinal sectional view of a luminaire according to the invention, designed as a spotlight, with a built-in unit comprising an LED light source; Fig. 2: The built-in unit of the luminaire of Fig. 1 in a schematic perspective view similar to an exploded view; and Fig. 3: The built-in unit of Fig. 2 in its assembled state. A luminaire 1 designed as a spotlight (spot) has an outer housing 2, only partially shown in the figure. The other components of the luminaire 1 are housed within this outer housing. Inside the housing 2 is an inner housing 3, which can also be referred to as a holder. As indicated by the double block arrow in Fig. 1, the inner housing 3 is adjustable in the longitudinal axial direction and thus in the direction of light emission from the luminaire 1. A reflector 4 is located inside the housing 2. A reflector chamber 5 is enclosed by the reflector 4. The surface of the reflector 4 facing the reflector chamber 5 forms the reflector surface 6. The reflector 4 has an opening 7. In the illustrated embodiment, this opening is located at the apex of the reflector 4, which is concave with respect to its reflector surface 6.Within the inner housing 3 is a light source carrier 8, which holds an LED light source 9. In the illustrated embodiment, this LED is a COB LED with a circular outline geometry. The light source carrier 8 also carries a light guide 10, which in the illustrated embodiment is made of glass. This light guide is rod-shaped and, in the illustrated embodiment, has a cylindrical outer surface. The light guide 10 is attached to the light source carrier 8 by means of a sleeve 11, which acts as a guide holder. The light source carrier 8 is a cylindrical component made of an aluminum alloy. This alloy has good thermal conductivity, so that during operation, the light source carrier 8 effectively dissipates heat from the LED light source 9. Therefore, active cooling is generally not required. When the luminaire 1 is operated, the light generated by the LED light source 9 is coupled into a coupling surface 12 of the light guide body 10. In the illustrated embodiment, the coupling surface 12 is the end face of the light guide body 10 facing the light source carrier 8. The light source carrier 8, together with the LED light source 9, is located outside the reflector 9 and is connected to the inner housing 3 in a manner not shown, such that any adjustment of the inner housing 3 also adjusts the light source carrier 8 and the components it supports, namely the LED light source 9 and the light guide body 10. The light guide 10 extends through the opening 7 of the reflector 4. The light guide 10 has a section 13, which, in the illustrated embodiment, also includes the end face 14 opposite the coupling surface 12. Light is coupled out of this section 13 of the light guide 10. Thus, the entire surface of section 13 of the light guide 10 represents its coupling surface. The light carrier 8 with the LED light source 9 and with the light guide 10 forms a mounting unit 15. This is explained in more detail in the following figures. From the schematic perspective view of the mounting unit 15 shown in Fig. 2, where the mounting unit 15 is shown without the sleeve 11, it can be seen that both the light carrier 8 and the light guide 10 are cylindrical bodies. The LED array of the LED light source 9 is shown in Fig.Figure 2 shows a schematic representation using a grid. The cross-sectional geometry of the light source carrier 8 can differ significantly from that of the light guide. For example, the cross-sectional area of ​​the light source carrier can be polygonal, such as hexagonal, while that of the light guide can be circular or circular. To increase the heat-radiating surface area of ​​the light source carrier 8, it can have cooling fins or other surface-enhancing structures on its outer circumferential surface. For light guidance, the light guide 10 has a stepped recess 16 incorporated into its end face 14, the stepped design being shown only in Fig. 3. In the illustrated embodiment, the recess 16 has three steps, each step having a smaller diameter towards the depth than the step adjacent to the opening of the recess 16. The inner wall of the recess 16 and the end face 14 are frosted to improve the scattered emission of light coupled out of section 13. In the illustrated embodiment, the end face 14 of the optical fiber 10 opposite the coupling surface 12 is also planar. It is understood that the end of the optical fiber opposite the coupling surface 12 can also have a different geometric design, for example, convexly curved, which also includes a hemispherical shape. A spherical shape for the light-emitting end of the optical fiber is also possible. The light guide 10 is connected to the light carrier 8 by means of the sleeve 11, as shown in Fig. 3, in such a way that the sleeve 11 keeps the light guide 10 permanently in its position shown in Fig. 3, even at the temperatures generated during operation of the LED light source 9. Fig. 1 shows, by way of example, beam paths of light coupled out from the output surface of the light guide body 10 during operation of the luminaire 1.In luminaire 1, all components of the original luminaire 1, which was operated with a conventional light source and retrofitted by the installation unit 15, have been retained. To convert this luminaire, previously operated with a halogen lamp, to LED technology, only the original light source holder and the halogen lamp were removed and replaced by the light source holder 8 with its components, namely the LED light source 9 and the light guide 10, i.e., the installation unit 15. The emission characteristics of the light guide 10 are designed in its output surface to be, at least as closely as possible, adapted to the emission characteristics of the previously used halogen lamp within the reflector 4. Therefore, the emission characteristics of luminaire 1 have not been changed by the upgrade to LED technology through the installation unit 15.Focusing of the light output surface within the reflector chamber 5 can be achieved by adjusting the inner housing 3 and thus the lamp holder 8. With the reflector 4, all additional components used with the luminaire 1, such as lenses and the like, can continue to be used while maintaining the originally configured beam pattern of the luminaire 1. For this reason, a particular aspect of using such a built-in unit is the conversion (upgrading) of a light fixture designed as a spotlight that is operated with a conventional light source. The invention has been described with reference to exemplary embodiments. Without departing from the scope of protection described by the applicable claims, numerous further embodiments of the inventive concept would be apparent to a person skilled in the art, without these needing to be explained in more detail within the scope of these explanations. Reference symbol list 1 Luminaire 2 Luminaire housing 3 Inner housing 4 Reflector 5 Reflector chamber 6 Reflector surface 7 Opening 8 Light source holder 9 LED light source 10 Light guide 11 Sleeve 12 Coupling surface 13 Section 14 End face 15 Mounting unit

Claims

Luminaire (1) designed as a spotlight with a light source (9) supported by a light source holder (8) and with a reflector (4) for the directed emission of light generated by the light source (9), characterized in that the luminaire (1) has a mounting unit (15) comprising the light source holder (8) and the light source (9) supported by it, in which the light source holder (8) is arranged outside the reflector space (4) and comprises as a light source an LED light source (9) and a light guide body (10) supported by the light source holder (8) and extending into the reflector space (5), which has an input surface (12) into which light generated by the LED light source (9) is coupled when the LED light source is operated, and an output coupling surface located within the reflector space (5) from which light from the light guide body (10) is coupled out in the direction of the reflector surface (6) of the reflector (4). Luminaire according to claim 1, characterized in that the light guide body (10) is rod-shaped. Luminaire according to claim 2, characterized in that the light guide body (10) is designed with a cylindrical outer surface. Luminaire according to claim 2 or 3, characterized in that the coupling surface (12) is provided by a planar end face of the light guide body (10). Luminaire according to one of claims 2 to 4, characterized in that the light guide body (10) has one or more light-directing structures in its section (13) providing the output coupling surface. Luminaire according to claim 5, characterized in that one or more light-directing structures are incorporated into the end face (14) of the light guide body (10) opposite the coupling surface (12). Luminaire according to claim 6, characterized in that the light-directing structures are provided by a recess (16) having one or more steps with a diameter decreasing towards the depth. Luminaire according to claim 7, characterized in that the outline geometry of the recess (16) providing the light-directing structures has the same geometry as the outer surface of the light guide body (10). Luminaire according to one of claims 1 to 8, characterized in that the light guide body (10) is connected to the light source holder (8) by means of a guide body holder (11). Luminaire according to claim 9, characterized in that the light guide body (10) is detachably connected to the lamp holder (8) for connection. Luminaire according to one of claims 1 to 10, characterized in that the coupling surface (12) of the light guide body is connected to the light emission side of the LED light source (9) via an optically conductive layer. Luminaire according to one of claims 1 to 11, characterized in that the lamp holder (8) with its light guide body (10) is adjustable relative to the reflector (4) in the direction of light emission. Luminaire according to one of claims 1 to 12, characterized in that the light carrier (8) is made of a heat-conducting material, for example a Cu or Al material, and the LED light source (9) is connected to the light carrier (8) in a heat-transferring coupling. Installation unit for converting a luminaire designed as a spotlight with a reflector and with a lamp holder (8) carrying an incandescent lamp or discharge lamp as a light source, the light source of which is arranged within the reflector space of the reflector, characterized in that the lamp holder (8) comprises an LED light source (9) as a light source and a light guide body (10) carried by the lamp holder (8) and extending into the reflector space (5) of a reflector (4) belonging to a luminaire, which has an input surface (12) into which light generated by the LED light source (9) is coupled when it is operated, and an output coupling surface located within the reflector space (5) from which light is coupled out of the light guide body (10) in the direction of the reflector surface (6) of the reflector (4). Installation unit according to claim 14, characterized in that it has the features directed towards the installation unit (15) of one or more of claims 2 to 13. Use of a built-in unit according to claim 14 or 15 for converting a luminaire designed as a spotlight with a reflector and with a lamp holder carrying an incandescent lamp type or discharge lamp type as a light source, the light source of which is arranged within the reflector space of the reflector, to operation of the luminaire with an LED light source.

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