WO2009121701A1

WO2009121701A1 - Light comprising a transparent body

Info

Publication number: WO2009121701A1
Application number: PCT/EP2009/052877
Authority: WO
Inventors: Jürgen Komar
Original assignee: Osram Gesellschaft mit beschränkter Haftung
Priority date: 2008-04-04
Filing date: 2009-03-11
Publication date: 2009-10-08
Also published as: DE102008017322A1; DE102008017322B4

Abstract

The invention relates to a light (1) comprising at least one light source (7) and at least one transparent body (8). The transparent body (8) comprises at least one practically flat light incidence surface (9) and at least one pratically flat light emergence surface (10). At least one surface (lateral surface (11)) of the transparent body (8), connecting the light emergence surface (10) to the light incidence surface (9), is curved in no more than one direction, and said at least one lateral surface (11) is formed, and the light source (7) at a distance from the light incidence surface (9), in such a way that, when the light (1) is laterally viewed throught the lateral surface (11) approximately perpendicularly to the optical axis (A) of the transparent body (8), the light source (7) is not visible.

Description

description

Luminaire with a transparent body

Technical area

The invention relates to a luminaire with at least one light source and at least one transparent body.

In addition to a light source, luminaires generally still have elements for influencing the light emission behavior, such as, for example, reflectors or shields. These

Elements serve, for example, to give the impression of a planar radiation source for a relatively punctiform light source in order to avoid dazzling the viewer.

Often, transparent bodies, such as glass, are used to achieve by reflection or refraction of the light emanating from the light source for the viewer pleasant or even fascinating effect. At the same time, transparent bodies are of particular interest to the observer, because the possibility of looking through them when the light source is switched off gives an optically inconspicuous impression, which can clearly change when the light source is activated by reflection or diffraction of the light emanating from the light source.

Since many users purchase luminaires not only because of the quality of the illumination, but also because of an extraordinary appearance or an astonishing effect contradicting everyday perception, luminaires having such an effect enjoy great popularity. All known luminaires according to the preamble of claim 1, however, have in common that the light source for the observer is to be localized, at least to some extent, by the observer looking through the transparent body. This also corresponds to the usual everyday experience.

Furthermore, luminaires are intended primarily to illuminate the area to be illuminated and to dazzle viewers, in particular in the lateral direction, ie. perpendicular to the preferred direction of radiation, be avoided. For this purpose, the lights are usually fitted with umbrellas or reflectors which are intended to prevent undesired lateral emission of light. However, these devices are not transparent, so that a viewer located on the side of the lamp is not dazzled, but also can not recognize what is behind the lamp, which is often a disadvantage. The lamp also makes a chunky and thus disadvantageous impression.

The object of the present invention is therefore to provide a luminaire with at least one light source and at least one transparent body, which arouses the attention and curiosity of a viewer by providing a sight that contradicts everyday experience. In particular, this is done by the fact that the light source from certain angles is not visible even when switched on, although there is only the transparent body between the viewer and the light source. Furthermore, the light in the lateral direction should be as glare-free as possible without disturbing the view in this direction considerably.

This object is achieved by the characterizing features of claim 1.

Particularly advantageous embodiments can be found in the dependent claims.

Since the light source is spaced from the light entry surface, an air-filled gap is provided between the light source and the light entry surface, so that the conditions for total reflection at the light entry surface for a light path coming from a side surface and / or thence in the transparent body at suitable angles are fulfilled.

At least one surface (side surface) of the transparent body connecting the light exit surface to the light entry surface is curved in no more than one direction and suitably shaped so that the light source is not visible through the lateral surface of the light. In this case, a lateral view is considered to be a view with a position of the observer in the region approximately between the light entry plane and the light exit plane at a distance of at least the distance from the light entry and exit plane. A surface is also considered to be curved in no more than one direction if one of the principal curvatures of the considered surface is identically equal to zero at all points. Under these conditions, the observer will see through the transparent body or towards the inside of the light entrance surface. che look where due to the total reflection not the light source arranged on the outside but only for example on the opposite side of the body lying objects are recognizable. Thus, the light seems to come directly from the light exit surface and thus from the transparent body itself, which allows the desired surprise effect and also prevents glare of the viewer located laterally of the transparent body, since no light exits the side of the light source from the light without disturbing reflectors would be visible.

By the light exit surface and the light entry surface are arranged approximately parallel to each other, an unobstructed, straight-through passage of the radiation emanating from the light source through the transparent body is given.

It is expedient if the distance of the light source from the light entry surface is less than 0.5 mm, in particular less than 0.1 mm, particularly preferably less than 0.05 mm. The smallest possible distance allows a compact design and also reduces light losses in the space between the light source and the light entry surface. In principle, the distance is advantageously to be selected so small that a direct large-area contact in breaking optic respect between the light source and the light entry surface is barely avoided. Depending on the surface quality of the components, this may also be the case when they are placed directly next to one another.

By forming the transparent body from a polymer material, in particular polymethyl methacrylate (PMMA), is det, one, especially in comparison to glass, a simple shape for the transparent body allows. This can be done either directly in the production, for example by casting process, as well as in subsequent machining by machining, grinding, polishing or gluing, In addition, polymeric materials have a low density, so that the lamp has a low weight and fasteners for both the lamp as well as for attaching the transparent body in the lamp can be easily performed.

In an advantageous development of the invention, the light source comprises at least one light-emitting diode (LED). Light-emitting diodes are energy-saving and very compact, so that the lamp can be designed very inconspicuous overall. In addition, light-emitting diodes emit very little heat, so that they bring in little heat even in close proximity to the transparent body. This is particularly advantageous in the case of transparent bodies made of a polymer material, since these high temperatures and inhomogeneous temperature distributions have a particularly disadvantageous effect on many properties, in particular the optical properties due to local changes in the refractive indices.

In a further advantageous embodiment, the light source comprises at least one surface radiator, in particular an organic light-emitting diode (OLED) and / or a flat-shaped discharge lamp, the light source preferably being formed essentially from the surface radiator. Surface spotlights ensure uniform illumination and are thus particularly suitable for use with luminaires Preferably irradiate large-area transparent body with correspondingly large-area light entrance surface. In particular, large-area light sources are less sensitive to possible inhomogeneities, for example inclusions, in the transparent body. Since the surface radiators are also preferably mounted with an alignment of the radiating surface parallel to the light entry surface of the transparent body and compared to their radiating surface perpendicular to this have a small extent, the luminaire has perpendicular to the light entry surface above this only a small extent.

With all the side surfaces of the transparent body curved in no more than one direction and the side surfaces shaped such that when the light is viewed laterally through the side surfaces approximately perpendicular to the optical axis of the transparent body, the light source is not visible, the effect discussed to be realized when looking at the luminaire from all sides, ie regardless of which side of the lamp is considered, the bulb is not visible and the viewer is protected against glare, the lamp makes a particularly filigree impression.

If there is at least one orientation for each side surface, to which a tangent is aligned in nearly every point of the side surface, the desired effect of transparency and glare protection is particularly well realizable. Since the major curvature of at least one side surface is approximately parallel to the optical axis at approximately every point and equal to zero, the tangents to the side surface are virtually parallel to the optical axis at all points, ie light rays incident perpendicular to the optical axis occur in a substantially straight line the transparent body. Examples of this would be flat side surfaces which run approximately parallel to the optical axis or a cylindrical side surface in which the cylinder axis runs approximately parallel to the optical axis. Thus, an unhindered view of the transparent body is possible.

In an advantageous embodiment of the invention, at least one side surface is practically flat. This allows an undistorted view of the transparent body and makes it very clear to the observer that no light source is visible when viewed from the side.

In an expedient development of the invention, the light entry surface and / or the light exit surface is approximately rectangular, in particular square. Rectangular surfaces are easy to produce and are well suited for light coupling, since most surface radiators have a rectangular or square basic shape. If the entrance and exit surfaces have the same shape, advantageously even the same size, the result is both a simple shaping of the transparent body and a simple beam path. In a further expedient development of the invention, the light entry surface and / or the light exit surface is approximately circular. Circular surfaces are easy to produce and are well suited for light coupling, since many light sources have a circular basic shape. Have entrance and exit surface the same shape, advantageously even with the same size, results in both a simple shape of the transparent body and a simple beam path.

In one embodiment of the invention, the luminaire is designed as a suspended luminaire, wherein the at least one light source and the at least one transparent body are fastened to a suspension part by means of a flexible suspension means. In the case of a suspended luminaire, the hanging part containing the light source is usually at a height at which a lateral view is in use, for which reason the effect of the non-visible light source and the glare shielding is particularly effective and also achieves a particularly filigree impression of the suspended part becomes.

By the suspension part of the pendant lamp comprises at least one ballast for powering the light source, the hanging part of the pendant lamp is particularly filigree executable.

Short description of the drawing (s)

In the following, the invention will be explained in more detail with reference to an embodiment. The figures show (show): 1 shows a suspension lamp according to the invention in a perspective view,

2 shows a suspension lamp according to the invention in a perspective detail view,

3 is a sectional view of the suspended part of the suspension lamp of Figure 1.

FIG. 1 shows a suspension lamp 1 according to the invention in a perspective view. On a suspension part 2 three hanging parts 4 are fixed by means of four flexible suspension means 3.

The suspension part consists of a rail 5 to which three retaining plates 6 are attached. At the holding plates 6 four wire cables 3 are attached, which also serve as a power supply to the hanging parts 4.

The suspended parts 4 are essentially formed from an organic light-emitting diode (OLED) 7 as a light source 7 and a transparent body 8.

In order to supply voltage to the OLEDs 7, three ballasts, not shown here, are arranged in the rail 5, to each of which a suspended part 4 is assigned. As a result, the three hanging parts 4 can be operated independently of one another, and if one ballast or an OLED 7 or a suspension means 3 fails, the other two hanging parts 4 can continue to be operated. The transparent body 8 is formed of polymethylmethacrylate (PMMA) and is substantially cube-shaped. The light entry surface 9 as well as the light exit surface 10 are thus square in this embodiment. The OLED 7 extends virtually over the entire upper surface of the hanging part 4, so that a pleasant light distribution is achieved.

The side surfaces 11 are aligned parallel to the optical axis A. A parallelepiped shape allows an almost unobstructed view through the body 8 through the mutually parallel side surfaces 11, so that for a viewer, the hanging part 4 is almost invisible when viewed from the side.

Only when viewing the light exit surface 10, as shown in Figure 2, the light source 7 or its image 12 is visible, the OLED 7 also provides a particularly pleasant and glare-free light due to the large-area radiation.

In Figure 3, the hanging part 4 is shown in a sectional illustration. The OLED 7 is placed directly on the transparent body 8 and secured to the edge regions 13 by means of an adhesive connection 14. The air layer between OLED 7 and transparent body 8 due to the natural roughness of the surfaces is sufficient to allow total reflection at the light entrance surface 9 for light rays entering through the side surfaces 11 and thus the light source 7 for the observer disappears when the light 1 is viewed from the side and to prevent leakage of light emitted from the OLED 7 through the side surfaces 11. Also glued to the body 8 is an opaque cover 16, at the same time the wire ropes 3 are fixed. It can be clearly seen that due to the flat design of the OLED 7, this is hardly recognizable in the side view and thus the hanging part 4 of the luminaire 1 is almost invisible to the viewer. The lateral adhesive bond 14, together with the gluing of the cover 16, ensures that no liquid gets between the OLED 7 and the light entry surface 9, which would lead to a cancellation of the total reflection at the light entry surface 9.

Of course, other embodiments are conceivable. Thus, in particular instead of the OLED 7, another light source 7 can be used. In order to keep the dimensions small, surface emitters such as the discharge lamps marketed under the name "Planon" by OSRAM GmbH are particularly suitable, but conventional light-emitting diodes are also suitable because of the small dimensions of the light source 7. The shape of the light source 7 does not necessarily have to be square Even if the transparent body 8 has a cube shape, when using a circular OLED, changing and interesting patterns may result on the light exit side depending on the viewing angle, for example.

Also, the shape of the transparent body 8 is not limited to a cube shape. However, all forms of straight or oblique prisms are particularly suitable, with the latter possibly not meeting the conditions for total reflection at the light entry surface 9 from all lateral viewing directions. In particular, prisms with circular, ellipsoid, tri-six or octagonal base offer itself. Cone or truncated pyramids may also be suitable shapes for the transparent body 8. The design of the side surfaces 11 is limited only by the condition of total reflection at the light entry surface 9, which essentially depends on the refractive index of the transparent body 8 and the beam path, ie the viewing direction.

Depending on the application and the light source 7 used, the light exit surface 10 can also be wholly or partially structured or matted, for example in order to achieve a diffuse radiation behavior in the case of a punctiform light source.

The luminaire 1 itself can of course also have other designs than shown here, for example in the form of a floor or ceiling lamp. Also, any other number may be used instead of the three hanging parts 4.

In particular, more or fewer wire ropes than shown or other suspension means 3 can be used for suspension.

Claims

claims

1. luminaire (1) with at least one light source (7) and at least one transparent body (8), characterized in that the transparent body (8) at least one practically flat light entry surface (9) and at least one practically flat light exit surface (10) wherein at least one surface (side surface (H)) of the transparent body (8) connecting the light exit surface (10) to the light entry surface (9) is curved in no more than one direction, and wherein the at least one side surface (11) is shaped as well as Light source (7) is spaced from the light entry surface (9) such that, when the light (1) is viewed laterally through the side surface (11) approximately perpendicular to the optical axis (A) of the transparent body (8), the light source (7 ) is not visible.

2. Lamp (1) according to claim 1, characterized in that the light exit surface (10) and the light inlet surface (9) are arranged approximately parallel to each other.

3. Lamp (1) according to claim 1 or 2, characterized in that the distance of the light source (7) from the light entry surface (9) is less than 0.5 mm, in particular less than 0.1 mm, preferably less than 0, 05 mm.

4. Luminaire according to one of claims 1 to 3, characterized in that the transparent body (8) made of a polymer material, in particular polymethyl methacrylate, is formed.

5. Lamp according to one of claims 1 to 3, characterized in that the light source (7) comprises at least one light emitting diode (LED).

6. Luminaire according to one of claims 1 to 3, characterized in that the light source (7) at least one nen surface radiator, in particular an organic light emitting diode (OLED) (7) and / or a sheet-like discharge lamp comprises, preferably substantially from the Surface radiator is formed.

7. Lamp according to one of claims 1 to 3, character- ized in that all side surfaces (11) of the transparent body (8) are curved in not more than one direction and the side surfaces

(11) are shaped such that in a lateral

Viewing the lamp (1) through the side surfaces (H) approximately perpendicular to the optical axis (A) of the transparent body (8), the light source (7) is not visible.

8. Luminaire according to one of claims 1 to 3, characterized in that there is for each side surface (11) at least one orientation for which in almost every point of the side surface (11) a tangent is aligned parallel.

9. Luminaire according to one of claims 1 to 3, characterized in that the main curvature of at least one side surface (11) approximately parallel to the optical axis (A) and is equal to zero

10. Lamp according to one of claims 1 to 3, characterized in that at least one side surface (11) is practically flat.

11. Luminaire according to one of claims 1 to 3, characterized in that the light entry surface (9) and / or the light exit surface (10) is approximately rectangular, in particular square, is formed.

12. Light according to one of claims 1 to 3, characterized in that the light entry surface (9) and / or the light exit surface (10) is approximately circular.

13. Luminaire according to one of claims 1 to 3, characterized in that the lamp (1) is designed as a pendant lamp (1), wherein the at least one light source (7) and the at least one transparent body (8) on a suspension part (2) are fastened by means of a flexible suspension means (3).

14. Luminaire according to claim 13, characterized in that the suspension part (2) comprises at least one ballast for powering the light source (7).