EP2492582A1 - Lamp and reflector for lamp - Google Patents

Abstract

The lamp (1) has a light source (4), a reflector (2) and a light conductor (3) that is arranged inside the reflector, where the reflector has a light source end (5) and a reflector outlet end (6). The light conductor has a light conducting portion (7) between a light input end (8) and a light output end (9), where the reflector and the light conductor are manufactured in a piece of glass.

Description

The invention relates to a lamp and a reflector for a lamp according to the preamble of the independent claims.

Such luminaires comprise a light source, a reflector and a light guide arranged inside the reflector. The reflector has a light source end and a reflector outlet end, wherein the light source is arranged at the light source end of the reflector. The light guide has a light entry end, a light exit end and an intermediate light-conducting section. The light entry end of the light guide is arranged at the light source end of the reflector, where the light source is located. The light guide extends from the light source such that the light exit end of the light guide comes to rest on a point between the light source end of the reflector and the reflector exit end.

Such a light is for example off US 2004/0228131 A1 known. This pamphlet deals with the use of LEDs as a replacement for conventional bulbs in flashlights. Conventional bulbs for use in a flashlight have a thread with which the bulb can be screwed into a socket or directly into the reflector of the flashlight. Furthermore, a conventional incandescent bulb comprises a glass bulb, which extends from the thread of the bulb in the direction of the outlet opening of the reflector and surrounds the filament of Glühbirnchens. This filament, together with the pear-shaped glass bulb surrounding it, forms a more or less point-like light source which is outstandingly suitable for use in a parabolic or ellipsoid reflector. Such reflectors are also used in flashlights. If you want to replace a conventional light bulb, which from today's point of view has a considerable power consumption, with an energy-saving LED, so you face the problem that the existing reflector is not optimally suited for the emission characteristics of a modern LED. In contrast to a conventional light bulb, an LED is not a punctiform light source, which radiates the emitted light more or less globally. The emission characteristic of a modern LED is at best hemispherical, with most of the light emitted in one direction. In order to continue to use the conventional reflector is in the US 2004/0228131 A1 suggested to direct the light of the arranged at the bottom of the reflector LED by means of an essay to the point in which is located in conventional incandescent filaments, and from there as uniformly as possible to radiate in all directions. The attachment thus functions as a light guide and comprises a light-conducting section for guiding the light from the LED to the desired emission point from the LED, and a light exit end for uniformly emitting the light at this point. The US 2004/0228131 A1 also proposes to simulate the LED and top unit of a conventional light bulb, and in particular to provide a thread and a glass bulb enclosing the LED and its attachment.

Furthermore, also the WO 2010/110652 A1 with the idea of replacing a conventional light bulb with an LED. Here, too, a light-conducting attachment is used. LED and photoconductive attachment are the same as the case US 2004/0228131 A1 known replacement bulb enclosed in a glass flask.

The desire to use LEDs in conjunction with known parabolic or ellipsoidal reflectors, however, extends not only to cases in which a conventional light bulb of an existing lamp with a corresponding reflector to be replaced. The radiation characteristic of known parabolic or Ellipsoidreflektoren is often desirable even in completely newly developed lights that use as a light source one or more LEDs or other bulbs whose radiated light must first be directed by a light guide to a certain point within the reflector to be radiated evenly from there. The encompassing of the LED known from the prior art as well as its light-guiding attachment with a glass bulb brings various disadvantages. The light-conducting attachment usually has to be encapsulated with the LED or at least adhesively bonded in order to ensure a secure fit. Since the LED and its attachment are enclosed together in a glass bulb, the existing LED, light-conducting attachment and glass bulb lamp unit must be replaced as a whole, if it is defective. If the lighting unit is used together with open reflectors, in many applications, a seal between the lamp unit and the reflector or between the lamp unit and the socket, in which it is screwed required. In addition, most of the reflector must be sealed against the housing of the corresponding lamp. Incidentally, this disadvantage also exists when the LED and the light-conducting attachment would not be included together in a glass flask. Even then, the interface between reflector and lichtleitendem essay would have to be sealed in certain applications.

Object of the present invention is therefore to improve a luminaire or a reflector of the aforementioned type on. In particular, an elegant shapely appearance of the lamp or the reflector is to be achieved while also the sealing of the lamp and the manufacture and installation should be simplified. Also, the invention is intended to enable a simple replacement of the bulb without the light-conducting attachment also has to be replaced. The lamp according to the invention or the reflector according to the invention should also be inexpensive to manufacture.

The object is solved by the features of the independent claims. Accordingly, there is then an inventive solution to the problem, when reflector and light guide are made in one piece from glass.

If the housing of the lamp is, for example, embedded in a wall or a ceiling, the viewer is given an extremely appealing appearance of the luminaire, since only the reflector and the optical fiber designed in one piece with it are visible to the outside. Particularly when the light is switched off, the elegant appearance is not clouded by dark sealing elements or the glass bulb of a conventional illuminant or a replacement solution known from the prior art, which releases the view of underlying components. A seal between light-conducting attachment and reflector is eliminated, since the two components are integrally connected to each other. Compared to the above-mentioned prior art, the invention also offers the advantage that the light source, so the light source such as an LED, can be replaced without the same time the photoconductive attachment must be replaced with. The integrally interconnected components reflector and light guide can also be made inexpensively in a simple manner.

Further advantageous embodiments of the present invention are the subject of the dependent claims.

An optimal emission characteristic of the lamp results when the reflector has a focal point, wherein the light exit end of the light guide is located in the focal point of the reflector. Thus, the light, which is guided, starting from the light source through the light guide into the focal point of the reflector, directed from there at optimal angles to the reflector. The term focal point used in this application should not be understood to mean a focal point in the strict sense, as it exists only with rotationally symmetrical reflectors. The term focal point thus also explicitly includes the focal line of an elongated two-dimensional reflector.

In a further particularly preferred embodiment of the present invention, the reflector has a threaded portion at the light source end. Preferably, this threaded portion is a sleeve-shaped or hollow-cylindrical extension at the lower light source end of the reflector, on whose inner or outer surface a thread is formed. With the threaded portion which consists of reflector and light guide unit can be screwed into the socket of a lamp housing. The threaded section assumes the function of sealing between the reflector and the lamp housing.

Preferably, a step-shaped shoulder is formed between the threaded portion and the adjoining part of the reflector. As a result, the seal against the lamp housing is further simplified. For example, a seal can be introduced between the step-shaped shoulder and a housing flange.

In a further particularly preferred embodiment of the present invention, reflector and optical fiber are made of pressed glass. This allows a very simple and inexpensive production of the existing reflector and optical fiber unit. In particular, this reflector and light guide can be produced in one operation.

Alternatively, it is also possible to manufacture the reflector and light guide separately and then to fuse together.

In a further embodiment of the present invention, the light exit end of the light guide is spherical. As a result, a good uniform point or spherical radiation of the light at the light exit end of the light guide is achieved. Uniform emission characteristics can be achieved with a particularly attractive appearance In particular, be achieved by a cone-shaped light exit end. Possible here is both a conical tip of the light guide, ie a cone aligned in the direction of the beam path, and a conical depression at the head end of the light guide, the tip of the cone in this case pointing against the beam path direction.

In a further preferred embodiment of the present invention, the light exit end of the light guide is reflective coated. This is particularly appropriate if the Lichtausrittsende of the light guide is designed as a conical recess. The light emitted by the light source is then first passed through the light guide to the light exit end and deflected at the reflective coated surface of the conical recess completely on the reflector. With appropriate geometry and using a suitable glass material, the effect of total reflection can be used instead of the reflective layer.

In a further preferred embodiment of the present invention, moreover, the reflector is reflective coated. Preferably, the coatings consist of a vapor-deposited aluminum layer. Thereby, the reflective coating can be inexpensively and easily manufactured.

In a further preferred embodiment of the present invention, the reflector is a parabolic reflector. This allows the use of the erfidungsgemäßen lamp as a spotlight.

The desired in particular ceiling lights radiation characteristic is best achieved when the reflector is designed as ellipsoidal reflector.

In a further preferred embodiment of the present invention, the light entry end of the light guide is formed dome-shaped. As a result, the unit according to the invention consisting of reflector and optical waveguide can be placed optimally on an LED, the light emitted by the LED being suitably coupled into the optical waveguide. However, the dome-shaped design of the light entry end is also suitable for other bulbs than LEDs.

In a further preferred embodiment of the present invention, the reflector, ie the distance between the light source end and the reflector outlet end, at least twice as long as the light guide, so the distance between the light entry end and light exit end. As a result, an extremely homogeneous light emission of the lamp is achieved.

An embodiment of the present invention will be explained below with reference to drawings.

Figur 1:

einen Schnitt durch eine Leuchte mit einer aus Reflektor und Lichtleiter be-stehenden Einheit,

Figur 2:

eine Seitenansicht der aus Reflektor und Lichtleiter bestehenden Einheit aus Figur 1, und

Figur 3:

eine Schrägansicht der aus Reflektor und Lichtleiter bestehenden Einheit aus Figur 2.

Show it:

FIG. 1:

a section through a luminaire with a unit consisting of reflector and light guide,

FIG. 2:

a side view of the existing reflector and optical fiber unit FIG. 1 , and

FIG. 3:

an oblique view of the reflector and optical fiber unit FIG. 2 ,

For the following statements applies that the same parts are designated by the same reference numerals.

The FIG. 1 shows a section of a lamp 1 according to the invention. The lamp 1 is designed as a ceiling light and shown for illustrative purposes upside down. It comprises a luminaire housing 10, a light source 4 and an attached unit consisting of reflector 2 and light guide 3. The housing 10 is usually embedded depending on the installation situation in the ceiling. In the illustrated light source 4 is an LED, wherein the application of the lamp according to the invention is not limited to the use of LEDs. Other bulbs would be conceivable.

The reflector 2 of the reflector and optical fiber unit is designed as EIlipsoidreflektor. The outer wall of the reflector is rotationally symmetrical about the optical axis 13. The upper Reflektorausrittsende 6 marks the light exit opening, from which the light of the lamp is radiated into the room. The lower end of the reflector 2 is continuously referred to in the application as the light source end 5, since the light source 4 is arranged at this lower end. The lower light source end 5 of the reflector 2 coincides with the light entrance end 8 of the concentric within the reflector arranged light guide 3 together. Reflector 2 and light guide 3 are made, so to speak, of one piece. A simple production of this unit consisting of the components reflector and light guide is achieved by means of pressed glass. The light entry end 8 of the light guide 3 is formed dome-shaped in order to ensure optimum coupling of the light emitted by the light source 4 in the light guide 3. Starting from the lower light entry end 8, a light-conducting portion 7 of the light guide 3 extends upward in the direction of the reflector exit end 6. The light-conducting portion 7 is also rotationally symmetrical to the optical axis 13 and has an upwardly tapering slightly conical outer surface. However, the outer surface of the photoconductive portion 7 may be made cylindrical or elliptical. In any case, should be achieved by the geometric design of the outer surface of the photoconductive portion 7 that the light coupled from the light source into the light guide light is optimally guided in the direction indicated by the reference numeral 9 light exit end of the light guide 3. It is therefore of advantage if a total reflection of the light emitted by the light source 4 takes place at the outer surface of the light-conducting section 7, which is also referred to as the lateral surface.

The light exit end 9 of the light guide 3 is formed as a conical recess and is located in the focal point of the reflector 2. On the surface of the conical recess, a reflective deposited aluminum layer is applied. This reflective layer ensures that the light guided upward from the light source 4 via the light-conducting section 7 is diverted more or less at the focal point of the reflector onto the reflector itself. With appropriate geometry can be dispensed with the reflective layer, if on the surface of the conical recess, a total reflection of the guided through the light guide light takes place.

The reflector itself is also provided with a reflective layer which, depending on the geometry, can be vapor-deposited either on the inside or the outside of the outer reflector wall. This layer is also a vapor-deposited aluminum layer.

As from the illustration in FIG. 1 and in particular the other views of the unit consisting of reflector and light guide, shown in the FIGS. 2 and 3 , is apparent at the lower light source end 5 of the reflector, a stepped shoulder 15 is formed. The step-shaped shoulder 15 connects the upper reflector part with a downwardly extending sleeve-shaped extension of the reflector, which is designed as a threaded portion 11. The cylindrical outer surface of the hollow cylindrical threaded portion 11 has a thread with which the unit consisting of reflector 2 and light guide 3 can be screwed into a socket 14 of the lamp housing 10. In this case, the step-shaped shoulder 15 of the reflector 2 comes to lie on the upper housing flange 16 of the lamp housing 10, wherein in the illustrated case, a sealing ring 12 is inserted between the step-shaped shoulder 15 and the housing flange 16. This sealing ring 12 is not required in most applications, but it allows a watertight seal of the lamp housing 10 by screwing the reflector 2 and the light guide 3 existing unit.

The invention is not limited to ceiling lights but can also be used in other lights, especially for spotlights.

Claims (10)

Luminaire (1) having a light source (4), a reflector (2) and an inside the reflector (2) arranged light guide (3), wherein the reflector (2) has a light source end (5) and a reflector outlet end (6) Light source (4) at the light source end (5) is arranged, the light guide (3) has a light-conducting portion (7) between a light entry end (8) and a light exit end (9), and wherein the light entry end (8) of the light guide (3) on Light source end (5) of the reflector (2), and the light exit end (9) of the light guide (3) between the light source end (5) and reflector outlet end (6) are arranged, characterized in that the reflector (2) and light guide (3) made of glass are made. Luminaire (1) according to claim 1, characterized in that the reflector (2) has a focal point, wherein the light exit end (9) of the light guide (3) in the focal point of the reflector (2). Luminaire (1) according to one of claims 1 or 2, characterized in that the reflector (2) at the light source end (5) has a threaded portion (11). Luminaire (1) according to one of claims 1 to 3, characterized in that the reflector (2) and light guide (3) are made of pressed glass. Luminaire (1) according to one of claims 1 to 4, characterized in that the light exit end (9) is conical or spherical. Luminaire (1) one of claims 1 to 5, characterized in that the light exit end (9) is coated reflective. Luminaire (1) according to one of claims 1 to 6, characterized in that the reflector (2) is coated reflective. Luminaire (1) according to one of claims 6 or 7, characterized in that the coating consists of a vapor-deposited aluminum layer. Luminaire (1) according to one of claims 1 to 8, characterized in that the light entry end (8) is formed dome-shaped. Reflector (2) for a luminaire (1) with a light source (4) and an inside the reflector (2) arranged light guide (3), wherein the reflector (2) has a light source end (5) and a reflector outlet end (6) Light source (4) at the light source end (5) is arranged, the light guide (3) has a light-conducting portion (7) between a light entry end (8) and a light exit end (9), and wherein the light entry end (8) of the light guide (3) on Light source end (5) of the reflector (2), and the light exit end (9) of the light guide (3) between the light source end (5) and reflector outlet end (6) are arranged, characterized in that the reflector (2) and light guide (3) made of glass are made.

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