WO1997030311A1

WO1997030311A1 - Light fitting

Info

Publication number: WO1997030311A1
Application number: PCT/FI1997/000089
Authority: WO
Inventors: Jari Tabell
Original assignee: Teknoware Oy
Priority date: 1996-02-14
Filing date: 1997-02-12
Publication date: 1997-08-21
Also published as: FI960664A; FI960664A0

Abstract

The invention relates to an invention comprising a light source (1), like a halogen bulb, a reflector (2, 3) for directing the light emitted by the light source and a body (4), whereto the light source (1) and reflector (2, 3) are supported and where a light output aperture (5) is located opposite the reflector. To keep the surface temperature of the light fitting low, direct light emission to the light output aperture (5) from the light source (1) has been essentialy prevented and the reflector comprises at least two separate reflecting surfaces (2, 3) for distributing the light into at least two light beams (6, 7) which flow out of the light output aperture (5).

Description

LIGHT FITTING

The invention relates to a light fitting comprising a light source such as a halogen bulb, a reflector for directing the light emitted by the light source and a body whereto the light source and the reflector are supported and wherein a light output aperture is located opposite the reflector. The light fitting of the invention is mainly intended to be used as a reading light for public transport passengers.

In similar above described known light fitting solutions the halogen lamp is directed directly onto the desired object . As a consequence of this the surface of the light fitting is very hot, even so hot that the user can get burns on his hand as he is adjusting the light fitting. It is difficult to insulate the heat of a halogen lamp because the power density of the light emission in the light output aperture will at any rate be quite high. In such a light fitting solution it is also problematical to direct the light beam since the position of the whole light source has then to be changed.

It is an object of the present invention to provide a new type of light fitting and especially a light fitting that is suited for use in public transport, and wherein the above-mentioned problems have been successfully eliminated, in other words to provide a light fitting which is safe and has a light beam that can easily be directed. This is achieved with the light fitting of the invention, characterized in that direct light emission from the light source to the light out¬ put aperture is essentially prevented and that the reflector comprises at least two separate reflecting surfaces for distributing the light emitted by the light source into at least two light beams which flow out of the light output aperture. In the solution of the invention the procedure is such that the light source is lo¬ cated inside the body of the light fitting so that it will not be possible for the user to touch the light source itself, and the light emitted by the light source is directed by means of two or more reflecting surfaces, whereby the emittance can be distributed over an extensive surface in the light output aperture, still without expanding the spread angle of the light beam.

In a preferred embodiment of the light fitting the body of the light fit¬ ting is elongated, with the light output aperture provided on its other long side, and the light source is arranged to emit light essentially in the longitudinal di- rection of the body of the light fitting and the reflecting surfaces arranged to reverse the light emitted by the light source out of the light output aperture. The structure is preferably obtained so that the light source is supported es¬ sentially to the other end of the body so that it is at least essentially sheltered by the body.

That it would be possible to direct the light beams in the desired manner the reflecting surfaces are preferably flat or a little concave or convex cylindrical surfaces, arranged to diverge in angle from each other with respect to the light emitted by the light source, in order to achieve a divergent direction of the light beams reflected by the reflecting surfaces. It is not supposed in this solution that the reflecting surfaces are turnable or tiltable, but it is only indi- cated that the reflectors have originally, already when they were assembled, been installed so that they direct their respective light beams in the desired way. On the other hand it is possible that the reflecting surfaces are supported in an articulated manner to the body of the light fitting, to render it possible to tilt the reflecting surfaces at least by one axis so that the light beams can be directed. By making the reflecting surfaces turnable at least by one axis a light fitting can easily be obtained in which the direction of the light beams created thereby can safely be adjusted by the user.

A light fitting of the invention is described in greater detail below with reference to the accompanying drawing, where Figure 1 shows a schematic side view of a cross-section of an em¬ bodiment of a light fitting of the invention and

Figure 2 shows the light fitting according to Figure 1 seen from the axial direction.

In Figure 1 a schematic cross-section of an embodiment of the light fitting of the invention is shown by way of example. The light fitting comprises a light source 1 that in the embodiment described is a halogen bulb 1 provided with a fixed reflector formed as a truncated cone. This halogen bulb 1 is sup¬ ported in the area of the other end 4' of the elongated body 4. In the described embodiment the body 4 has been presented as being formed generally as a rectangular prism wherein a light output aperture 5, furnished with a transpar¬ ent cover or grate, is provided in the area of the central part of its other long side. This light output aperture 5 is located so in the body 4 that the light emitted by the light source cannot escape directly through the light output ap¬ erture 5. In practice this has been done so that the light source 1 is placed in the area of the other end of the body, sheltered by the body, and directed so that it emits light essentially in the direction of the longitudinal axis of the body 4.

To be able to direct the light emitted by the light source 1 out of the light output aperture 5, located in the central part of the long side of the body 4 of the light fitting, two reflectors 2 and 3 have been supported to the inside of the body 4 of the light fitting. In the described embodiment these reflectors are arranged at an angle of approximately 45 degrees in relation to the light emit¬ ted by the light source 1 , whereby they will emit two light beams 6 and 7 in an essentially perpendicular direction in relation to the longitudinal axis of the body 4. In the described embodiment the reflectors 2 and 3 that can be for in¬ stance mirror surfaces, are presented as attached to each other so as to form a stepped construction. Such a uniform construction comprising several re¬ flecting surfaces naturally makes installation easier than in a case where sev¬ eral separate reflecting surfaces are used. As shown in Figure 1 the reflecting surfaces 2 and 3 are arranged one behind the other along the longitudinal axis of the body 4 so that the first reflector covers about half of the light beam emitted by the light source, and the other reflector 3, located farther from the light source, covers the other half of the light beam emitted by the light source. In this way the light intensity of the light beams 6 and 7 emitted by the reflectors, is at least nearly equal, but due to the axial distance of the reflecting surfaces in the body 4 of the light fit¬ ting the light beams reflected by them are axially separate in a corresponding manner. Still it is more essential that the light beams 6 and 7 can be directed separately either by making at least one axis of the reflecting surfaces articu- lated, or if they are fixed by installing them originally at divergent angles to the light beam emitted by the light source 1. A procedure like this has been em¬ ployed in the embodiment described, as illustrated in Figure 2.

In Figure 2, where the light fitting of Figure 1 is shown from the axial direction, it is seen that the light beams 6 and 7 are directed diagonally to the sides with respect to the vertical axis. This is of course based on the fact that the reflecting surfaces 2 and 3 are not located on parallel planes. Besides be¬ ing plane surfaces the reflecting surfaces, which could of course be more in number, could also be somewhat concave or convex cylindrical surfaces, whereupon they would either spread or contract the light beam they reflect. A light fitting like that in Figures 1 and 2 is very suitable for use e.g. as a reading light in public transport. The light fitting can then, for instance, be installed in a longitudinal direction at the outer edge of the overhead stowage above two adjacent seats. Since this outer edge is normally located between the two adjacent seats below it, light beams 6 and 7, directed like those in Fig¬ ure 2, will direct the light right where these adjacent seats are. An position of installation like that mentioned, i.e. a metal profile at the edge of the overhead stowage, is very well suited as a position of installation for the light fitting of the invention also because the edge rail transmits the heat generated by the light source along quite a long distance of this edge rail, whereupon the tem¬ perature of the rail does not significantly increase by the impact of the light fit- ting.

A significant advantage of the light fitting solution of the invention is also that the light fitting can be designed in a slender form and that the light beams can be directed in the desired direction without changing the position of the light source per se. As has been shown above such a possibility of direct- ing the light can be carried out either by using fixed reflecting surfaces or re¬ flecting surfaces that are adjustable by the user.

The light fitting of the invention has been described above by way of example in one embodiment only and it is clear that a light fitting of the inven¬ tion could be designed in an essentially different way from what has been thought in the described embodiment without still departing from the scope of protection of the accompanying claims. The essential idea of the light fitting of the invention is that the light source cannot be touched directly, but is located so that it is shielded by the body of the light fitting, and that the light emitted by the light source is reflected by at least two reflecting surfaces, whereby the light emission can be distributed over a larger surface, still without expanding the spread angle of the light beam. It is just because of these factors that the temperature of the light output aperture is essentially lower than in light fittings where the light source, especially a halogen lamp, is directed directly onto the desired object.

Claims

1. A light fitting compπsing a light source (1), such as a halogen bulb, a reflector (2, 3) for directing the light emitted by the light source and a body (4) whereto the light source (1) and the reflector (2, 3) are supported and wherein a light output aperture (5) is located opposite the reflector, char¬ acterized in that direct light emission from the light source (1) to the light output aperture (5) is essentially prevented and that the reflector com¬ prises at least two separate reflecting surfaces (2, 3) for distributing the light emitted by the light source into at least two light beams (6, 7) which flow out of the light output aperture (5).

2. A light fitting according to claim 1, characterized in that the body (4) of the light fitting is elongated, with a light output aperture (5) pro¬ vided on its other long side, and that the light source (1) is arranged to emit light essentially in the longitudinal direction of the body (4) of the light fitting and the reflecting surfaces (2, 3) arranged to reverse the light (6, 7) emitted by the light source out of the light output aperture (5).

3. A light fitting according to claim 1 or 2, characterized in that the light source (1) is supported to the body (4) essentially in the area of its other end (4') and is at least essentially sheltered by the body (4).

4. A light fitting according to any one of claims 1 - 3, charac¬ terized in that the reflecting surfaces (2, 3) are plane surfaces or slightly concave or convex cylindrical surfaces.

5. A light fitting according to any one of claims 1 -4 , charac¬ ter i z e d in that the reflecting surfaces (2, 3) are arranged one behind the other in the axial direction of the body (4) and that each reflecting surface (2, 3) is arranged to receive only a part of the light emitted by the iight source (1).

6. A light fitting according to any one of claims 1 - 5, charac¬ terized in that the reflecting surfaces (2, 3) are arranged to diverge in an¬ gle from each other with respect to the light emitted by the light source, in or- der to achieve a divergent direction of the light beams (6, 7) reflected by the reflecting surfaces.

7. A light fitting according to any one of claims 1 -6, charac¬ terized in that the reflecting surfaces (2, 3) are supported to the body (4) of the light fitting in an articulated manner to make possible a tilting of the re- fleeting surfaces by at least one axis so that the light beams (6, 7) can be di¬ rected.