Luminaire

Abstract: The luminaire according to the invention comprises a reflector (2) in a housing (1), a lampholder (6) for accommodating an electric lamp (10) parallel to a window (3) and to second sides (5) thereof, and a pane (7) closing the window. Lamellae (8) are present near the window, transverse to the main direction of the lamp. The luminaire has lamellae in regions adjacent first sides (4) of the window, only. In an embodiment of the luminaire the lamellae are not linked to the pane. The luminaire allows for an easy replacement of the lamp and easy cleaning of the pane. An increased light output is obtained, too.

Description: The invention relates to a luminaire comprising: a housing provided with a reflector and with a light emission window with first and second mutually opposing sides. Such a luminaire is known from CH-A-677 398. The known luminaire has a light transmitting shell closing the housing and an electric lamp arranged with its longitudinal axis at about the interface of the housing and the shell. Several lamellae are present at either side of the lamp, parallel to its longitudinal axis, the inclination of which may be adjusted in dependency of the area laterally of the lamp to be illuminated through raised portions of the shell. A luminaire for the illumination of road tunnels is known from CH-C-449 919 the light emission window of which is dosed with a pane, along which an electric lamp is accommodated in the luminaire, its longitudinal axis to be arranged in the length direction of the tunnel. A lamellae grid, having a plurality of lamellae transverse to the axis of the lamp, is present between the lamp and the base, fixed to the housing so as to be slidable. The grid is present below the portion of the lamp which is directed towards approaching traffic, only. It is thereby achieved that the luminaire emits light towards approaching traffic under a smaller angel with the vertical than in the opposite direction. However, a lamellae grid covering substantially the whole of the lamp should be present according to this patent, in the case traffic would pass from the other direction, too. A luminaire is known from DE-GM 76 01 614 which has a raster of parallel lamellae coupled to the pane closing the light emission window. The object of the raster is to prevent glare in opposite directions at comparatively wide angles to the perpendicular on the pane. A disadvantage of the lamellae attachment near the light emission window is that the raster is to be removed for exchanging a defective lamp. This disadvantage is counteracted in the known luminaire in that the raster is coupled to the pane. When the housing is opened, the lamp becomes immediately accessible. Coupling of the raster to the pane, however, has the disadvantage that cleaning of the pane is difficult and requires much time because the pane is not readily accessible. It is an object of the invention to provide a luminaire of the kind described in the opening paragraph which is of a construction which renders an enclosed lamp easily accessible for exchange and in which cleaning of a pane is also rendered easier. According to the invention, this object is achieved by a lampholder in the housing for accommodating an electric lamp inside the reflector alongside the emission window, alongside the second sides thereof, a pane closing the emission window, and several lamellae near the light emission window along the first sides thereof, transverse to the pane, the lamellae being present only in regions adjacent the first sides of the emission window, so as to render it possible to insert or remove a lamp through the central region inbetween the lamellae of the two regions adjacent the first sides. It was found that it is not necessary for lamellae to be present over the entire light emission window for the restriction of the angles to the perpendicular on the pane at which high brightnesses in the luminaire can be observed during operation. If such lamellae are present only in regions at the first sides, and are accordingly absent in the interposed central region, it is already achieved that high brightnesses of the lamp accommodated in the luminaire and of the reflector cannot be observed at great angles. The measure in the luminaire according to the invention has the result that cleaning of the pane in the case in which the lamellae are coupled thereto is much less time-consuming. In a favourable embodiment of the luminaire, the lamellae are uncoupled from the pane. The lamellae are then fastened, for example, to the reflector or to the housing. The pane can then be cleaned very easily at both its surfaces. Coupling of the lamellae to the housing, possibly by way of the reflector, provides a very reliable position of the lamellae relative to the reflector and the lamp. The absence of lamellae in the central region of the light emission window renders it possible to insert or remove a lamp through the central region, in between the lamellae of the two regions adjacent the first sides. Depending on the geometric relations between the lamp and the luminaire, it may be necessary during this to move the lamp into or from the housing parallel to the lamellae. An additional favourable property of the luminaire is that the absence of lamellae in the central region results in an increase in the luminous flux from the luminaire. An embodiment of the luminaire according to the invention is shown in the drawing. Therein is: Figure 1 a longitudinal cross-section; Figure 2 a cross-section according to II - II in Figure 1. In the drawings, the luminaire has a housing 1 provided with a reflector 2 and with a light emission window 3 with first 4 and second 5 mutually opposing sides. A lampholder 6, an E-40 holder in Figure 1, is present in the housing for accommodating an electric lamp 10 inside the reflector alongside the emission window, along the second sides thereof. A pane 7 closes the emission window. Several lamellae 8 are arranged near the light emission window along the first sides thereof, transverse to the pane. The lamellae 8 are present only in regions 9 adjacent the first sides of the light emission window. They are uncoupled from the pane 7. In the Figure, the lamp is a high-pressure sodium discharge lamp which consumes a power of 250 W during operation. The lamellae 8 in the luminaire drawn are fastened to the reflector. The lamp can be removed from the luminaire through the central region of the emission window between the regions 9. The pane 7 is free from lamellae and can as a result be easily cleaned at both its surfaces. In the case of a conventional arrangement of lamellae, two more lamellae would be present in the central region with a mutual interspacing and a distance from the drawn lamellae equal to the interspacings of the lamellae in each of the regions 9. The lamellae 8 prevent an observer from looking into the lamp or from observing high brightnesses coming from the reflector at an angle in excess of an angle α. The luminaire shown is designed for recessed mounting into a false ceiling.

Claims: A luminaire comprising: a housing (1) provided with a reflector (2) and with a light emission window (3) with first (4) and second (5) mutually opposing sides, characterized by a lampholder (6) in the housing for accommodating an electric lamp inside the reflector (2) alongside the emission window (3), alongside the second sides (5) thereof, a pane (7) closing the emission window (3), and several lamellae (8) near the light emission window (3) along the first sides (4) thereof, transverse to the pane (7), the lamellae (8) being present only in regions (9) adjacent the first sides (4) of the light emission window (3), so as to render it possible to insert or remove a lamp through the central region in between the lamellae (8) of the two regions (9) adjacent the first sides (4). A luminaire as claimed in Claim 1, characterized in that the lamellae (8) are fastened to the reflector (2).

Inventors: ENTROP JEAN PAUL, WIJBENGA HENDRIK, ENTROP, JEAN PAUL, WIJBENGA, HENDRIK, Entrop, Jean Paul, c/o Int. Octrooibureau B.V., Wijbenga, Hendrik, c/o Int. Octrooibureau B.V.
Applicants: PHILIPS ELECTRONICS NV, PHILIPS ELECTRONICS N.V.
Application year: 1993
Main classification: F21V11
IPC codes: F21V11, F21S8, F21V19, F21V13