DE102008060874A1 - lamp - Google Patents

Abstract

The present invention relates to a luminaire having a luminaire housing, and at least one longitudinally extending elongated luminous means in the form of a fluorescent lamp, wherein at least a portion of the luminaire is covered at the bottom by a partially translucent prismatic plate and below at least one illuminant at least one opaque cover is provided, which prevents an immediate light leakage from the light source directly downwards, this light is according to the invention characterized in that at least one light source (12) is arranged approximately in the central region of the lamp and below this light source is at least one counter-reflector (14) which reflects a part of the luminous flux emitted by the luminous means onto a main reflector (11) arranged above the luminous means and that light reflected by this main reflector passes through the prismatic platen e (13) downwards out of the luminaire.

Description

The The present invention relates to a luminaire with a luminaire housing, and at least one longitudinally extending elongated one Light source, with at least a portion of the light down through a partially translucent prism plate is covered and wherein below at least one light source at least an opaque cover element is provided, which direct light leakage from the bulb directly prevented downwards.

to shine of the aforementioned type have a first portion of light after is radiated down and thereby through the prismatic plate exit and another share of light, which of the lamp is radiated towards the ceiling and from the ceiling in the space is reflected and thus indirectly on a to be illuminated Zone of a workplace falls in a room. These lights are also referred to as direct / indirect-radiating.

At one of the DE 203 21 097 U1 known light is a ceiling pendant lamp of the aforementioned type, in which two fluorescent lamps are located in the outer edge regions of the lamp and are covered at the bottom over each closed areas of the lamp housing. In a central area between the two bulbs, the opening of the lamp is covered by a prismatic plate. There are also obliquely upwardly directed to the luminaire center inclined arranged Lichtleitbleche used to direct the proportion of light upwards and to let only light rays at shallower angles downwards through the prismatic plate. The aforementioned luminaire has a very flat luminaire housing and is particularly suitable for illuminating workplaces which have an increased requirement for reflected glare, as well as computer workstations which have a sharply inclined or flat screen. An advantage with luminaires of this type is that the light is decoupled so that below the 0 ° -30 ° level the luminance is <1000 cd / m ² . The 0 ° -30 ° plane is the plane at which reflected glare is created by the ray path of the light.

With the glare limitation one differentiates according to the standard DIN EN 12464-1 between the limitation of direct glare, where a minimum screen angle is to be observed for all levels of radiation, to prevent the person from directly looking into the light source at work and to avoid reflected glare caused by reflections on reflecting surfaces. For the latter, luminance values above 1000 cd / m ^{2 should} be avoided at beam angles greater than 65 ° to the vertical. However, the standard is still based on conventional screens, which have a slope of only up to 15 ° to the vertical and does not consider more inclined or flat screens.

In the WO 00/50806 A1 a luminaire is described in which two fluorescent lamps are located in the central region of the luminaire and under these a conventional luminaire grid with longitudinal reflectors and cross blades is arranged. Hollow chambers are also provided on both sides of the fluorescent lamps, the underside of which is covered in each case by plate-shaped light distribution elements, through which light emerges downwards. These light distribution elements are intended to diffuse the light diffusely. This luminaire is also a direct / indirect light, as light is also emitted upwards towards the ceiling. The direct light emission from the light source directly downwards is not prevented here. This proportion of light is directed in the known lamp only by the lighting grid in a conventional manner.

at Both prior art lights are those in which the indirect portion of the radiated light is thereby that the luminaire housing at the top of the lamp respectively has a light-transmissive cover or the light on the top is partially open. Usually leaves This concept is only possible when suspended from the ceiling Realize lights (pendant lights).

The Object of the present invention therein, a luminaire of the above mentioned genus with a bottom cover by a prismatic plate to provide that on an alternative photometric Concept is based, good glare properties according to the Standard and at the high luminance on the prism plate be avoided in the area below the bulb.

The Solution of this task provides a luminaire of the beginning said genus with the characterizing features of the main claim. According to the invention provided that at least one lamp approximately in the central region the lamp is arranged and below this bulb at least one counter reflector is located, which is part of the the luminous flux emitted to the lamp to one above the Bulb arranged main reflector reflects and that of this Main reflector reflected light through the prismatic plate comes down out of the lamp.

By the use according to the invention of the counter-reflector can be achieved that a high luminance on the prism plate is prevented below the bulb.

Of the Counter reflector is narrower than the main reflector, creating a Partial current of the light falls from the bulb to the main reflector, another partial stream but also past the counter-reflector down can fall on the prism plate. This can be done through the prism plate pass through and thereby refraction according to the deflected specific design of the prismatic plate accordingly become. Part of the light is also due to the total reflection this prism plate reflects and then meets first on the main reflector. The width of the counter-reflector is preferably only a fraction of the width of the main reflector.

The Shape of the counter-reflector depends among other things on the arrangement the bulb in the lamp, for example, its vertical Distance to the main reflector and can also be dependent, for example vary from the type of luminaire (surface-mounted luminaire, recessed luminaire, etc.), For example, forms with at least one laterally outer to the horizontal downwards angled or curved Leg preferably, if the one or more bulbs closer at the main reflector, that means further inside the luminaire housing and then it is when the (vertical) distance of the bulbs larger from the main reflector, prefers shapes, in which the counter-reflector at least one laterally outer to the horizontal upwards angled or curved Has leg.

The Light source, which in particular one or more fluorescent lamps may also be outside one in a ceiling (partially) recessed luminaire housing are, in particular for recessed ceiling luminaires also the underside of the luminaire by a trough-shaped or in cross-section U-shaped prism cover may be covered, which includes the prism plate. In this variant the lamp may, for example, a lateral region of the trough-shaped or U-shaped prism cover have a different prismatic structure as the remaining area of the prism plate Prism cover. This side area can be used to one through the trough-like or U-shaped prismatic cover laterally emerging light component through the prism structure to the ceiling to divert attention. This proportion of light is then reflected from the ceiling and thus serves as an indirectly emitted light component. To such a you can also create the side light Prism cover in this side area with another Forming a prism profile structure than in the lower area of the prism plate, which the light coming from the light downwards light directs. For example, in the lateral area be arranged sawtooth prisms.

In For example, primers can be used in the area of the prism plate having a substantially triangular structure with an acute angle or rectangular profile can be used. The invention is however by no means limited to such a prism structure. Rather, it depends on which radiation characteristic in each case is desired and the prism structure is corresponding customized. For example, the prism plate has a comparatively sharp-edged prism structure as advantageous proved, since in this case a directed light control by the Prism plate is achieved better. The prism structure is preferred either in the lamp longitudinal direction or in the longitudinal direction and aligned in the transverse direction of the lamp axis direction. In the latter Case may be, for example, a pyramidal prismatic structure act.

Preferably the main reflector of the luminaire is parabolic in cross-section educated. The usually narrower counter reflector is from Main reflector seen on the other side of the bulb arranged and can be bent, for example, one or more times or curved.

Prefers is the luminaire according to the invention a ceiling recessed or ceiling mounted luminaire. If the main reflector partially open at the top, the lighting technology principle but also be applied to pendant or floor lamps.

When Bulbs are usually elongated in lights of this type Fluorescent lamps preferably used with smaller diameters. The prism structure of the prism plate preferably follows according to the invention the direction of the lamp.

The In the subclaims described characteristics relate preferred developments of the invention Solution of the problems. Further advantages of the present invention result from the following detailed description.

following the present invention is based on embodiments with reference to the accompanying drawings closer explained. Showing:

1 a cross-sectional view through a lamp according to a first alternative embodiment of the present invention;

2 a cross-sectional view of a second slightly modified embodiment of a Luminaire according to the present invention;

3 an enlarged detail view of a section III of in 2 illustrated light;

4 a sectional view of a lamp of in 1 of the type shown, in which some exemplary light beams are drawn in order to sketch the beam path;

5 a sectional view of a lamp of in 2 shown type in which some exemplary light rays are drawn to sketch the beam path.

First, on the 1 Reference is made, which shows a schematically simplified cross section through a lamp according to a first possible embodiment of the present invention. These are, for example, a ceiling-mounted luminaire or recessed ceiling luminaire with an elongated, comparatively flat luminaire housing which is rectangular in plan view, for example 10 , in which the usual electrical installation equipment such as ballasts, connection devices, etc. are housed, which will not be discussed in detail here. In the luminaire housing 10 is for the light control a substantially parabolic in cross-section reflector 11 arranged inside of which is an elongated fluorescent lamp as a light source 12 whose axis extends in the longitudinal direction of the housing. In this embodiment, the fluorescent lamp is arranged in the upper region of the reflector and is located approximately in the center of the reflector, seen in the transverse direction of the lamp. Towards the bottom, the housing of the lamp is by a prism plate 13 covered here, which closes the given through the reflector cavity and through which the light emerging down through falls. In this prism plate 13 this is one in which parallel prisms approximately triangular in cross-section extend in the longitudinal direction of the lamp. These triangular prisms can, for example, have a pointed or right angle on the underside.

According to the invention is now below the fluorescent lamp 12 a counter reflector 14 , by the direct emission of the luminous flux coming from the fluorescent lamp vertically down to the prism plate 13 is avoided, so that too high a luminance on the prism plate is prevented below the lamp. The latter would run counter to the concern of achieving a directed exit of the light with the desired non-glare light emission characteristic here. A partial current of the light thus falls from the fluorescent lamp 12 out first on the counter reflector 14 and goes up past the lamp to the main reflector 11 reflected. From there, the light is then reflected in a corresponding angle according to the laws of optics, falls on the prism plate 13 , There undergoes a distraction by refraction and exits down from the lamp in the desired beam angle.

A partial current of the light falls from the fluorescent lamp 12 starting laterally or upwards and hits directly on the main reflector 11 where it is reflected accordingly in the direction of the prism plate, through which it then exits after refraction. Another sub-stream of light falls from the fluorescent lamp 12 from the side down to the counter reflector 14 over and then passes at a shallower angle directly to the prism plate 13 where the light rays are deflected again and emerge down. At steep angles, however, because of the arranged there counter-reflector 14 the light from the lamp 12 not directly down on the prism plate 13 fall.

The partial flow of the fluorescent lamp 12 is radiated laterally down from even shallower angles, is reflected due to the total reflection at the top of the prismatic plate and thus does not occur directly through it. This portion of the light is thus reflected by the reflection on the main reflector 11 thrown back, there again reflected and occurs at a different angle down through the prismatic plate 13 out.

The shape of the counter-reflector 14 is how you look 1 can recognize so that a middle in the installed state flat approximately horizontal section 14a below the fluorescent lamp 12 is provided, at the sides on both sides at an obtuse angle down angled leg 14b . 14c followed. It therefore results in total for the counter reflector 14 a flat trough shape or shape of a bottom open trapezium, which is virtually upside down, so that the broader side is down and open, while the narrower side through the middle section 14a is formed and relatively close to the fluorescent lamp 12 borders. A similar lighting effect can be achieved if the counter-reflector is not angled twice but formed curved with a similar basic shape, but the middle section and the two lateral legs merge into one another in a radius.

2 , to which reference is made below, shows an alternative embodiment of the luminaire according to the invention, which is mainly used for recessed ceiling luminaires into consideration. Accordingly, the light is in 2 in one in a blanket 15 installed state shown. The luminaire housing 10 is in this variant predominantly of the blanket 15 added. It is here a cross-section trough-shaped or U-shaped prism cover 16 used a horizontal prismatic plate 13 comprises, which may be constructed similar to the embodiment described above according to 1 , The prism cover 16 is located below (outside) the ceiling 15 in which the luminaire is installed.

The main reflector 11 is also parabolic here in cross section. The fluorescent lamp also extends here in the longitudinal direction, wherein the housing is preferably again designed to be rectangular and in 2 is shown cut in the transverse direction. Unlike the variant described above, however, in the variant according to 2 the fluorescent lamp 12 at a greater distance to the main reflector 11 arranged so that the fluorescent lamp 12 compared with the variant of 1 located below, their axis runs here below the built-in ceiling part of the lamp and thus slightly below the ceiling 15 , This results in other lighting conditions. The counter reflector 14 is also in the variant 2 under the fluorescent lamp 12 , but here has a different shape and the distance of the counter-reflector 14 from the main reflector 11 is much larger, since the distance of the fluorescent lamp 12 from the main reflector 11 is larger. For this reason, the shape of the counter-reflector has been changed. In this case, the counter-reflector in turn has a central horizontal portion, to which, however, laterally angled legs adjoin each other on both sides, which are angled upwards at an obtuse angle. This can be done by the fluorescent lamp 12 outgoing rays only on the prism plate 13 when they are radiated at even shallower angles. A larger proportion of the light emitted by the lamp is therefore here by the counter-reflector 14 first in the direction of the main reflector 11 is radiated and then from this towards the prism plate 13 reflected.

As in the variant according to 2 the prism cover 16 a tub shape or U-shape with lateral areas 17 , which as you can see approximately at the height of the fluorescent lamp 12 lie, here is a lateral light emission through the lateral areas 17 possible through. Partially be from the fluorescent lamp 12 radiated luminous flux components, which at flat angles to the top of the prism plate 13 hit, reflected by total reflection at this and the passage through the lateral areas, which are also designed as a prismatic plate, broken and deflected and then hit the ceiling 15 in the vicinity of the lamp. From the fluorescent lamp 12 Light rays radiated directly upwards and those which are emitted upward by reflection at the counter reflector reach the main reflector 11 and are reflected by it and at steeper angles through the prism plate 13 passed through from the lamp downwards.

The enlarged detail view according to 3 shows that the lateral areas 17 are formed as a prism plate with a sawtooth prism profile structure on the outside, whereas the bottom of the horizontal prism plate 13 has a triangular prism profile structure with isosceles triangles. By choosing these different prism structures below the fluorescent lamp or laterally of this, the desired Lichtabstrahlcharakteristik can be supported. The light that passes through the lateral areas with the sawtooth prism profile structure is refracted towards the ceiling.

Due to the U-shape in cross section, the height of the luminaire is according to 2 slightly larger than in the variant according to 1 , The trough-shaped prism cover 16 is as you can see below the ceiling 16 , Depending on the arrangement of the fluorescent lamp in the luminaire and its distance to the main reflector, depending on the shape of the counter-reflector 14 , Cross-sectional shape of the prism cover 13 . 16 as well as prism profile structure of the prism cover 16 or prism plate 13 you can vary the emission characteristics of the lamp according to the invention. In the two examples were each lights with only one fluorescent lamp 12 shown. As well, of course, you can use several fluorescent lamps, with two lamps can be arranged directly next to each other.

The following is with reference to 4 the beam path of the light emission of a lamp according to the invention of 1 illustrated type explained in more detail. There are only a few exemplary light rays shown, the principle of radiation with main reflector 11 and counter reflector to clarify. In fact, the beam path is more complex and not all radiated light components are considered here.

It is a first ray of light 18 shown by the lamp 12 starting at a shallower angle, first onto the main reflector 11 falls, there according to the optical laws (angle of incidence = angle of reflection) is reflected and then on the prism plate 13 falls, where it is broken and at a deflected angle down from the lamp 10 exit. Another ray of light 19 is shown by the lamp 12 at a steeper angle, starting at the prism plate 13 falls and emerges through the bottom down out of the lamp. Right is a third ray of light 20 drawn, which of the lamp 12 starting first on the Ge genreflektor 14 is reflected by this at the appropriate angle upwards and then on the main reflector 11 is reflected, this is reflected in turn down, then on the prism plate 13 meets, is broken there and emerges down out of the lamp.

Below will now be with reference to 5 the beam path of the light emission of a lamp according to the invention of 2 illustrated type explained in more detail. There are only a few exemplary light rays shown, the principle of radiation with main reflector 11 and counter reflector 14 to clarify. In fact, the beam path is more complex and not all radiated light components are considered here. On the left side in the drawing is a ray of light 21 shown at first by the lamp 12 is radiated upward and on the main reflector 11 falls, where it is reflected down, so that he is on the prismatic plate 13 falls, where a refraction occurs with direction change, so that the beam 21 in the direction shown downwards out of the lamp exits.

On the left side in the drawing is another ray of light 22 shown which of the lamp 12 starting at a very shallow angle, so that it hits the prism plate 13 exceeds the critical angle of total reflection. Consequently, the light beam enters 22 not through the prism plate 13 through, but is reflected at this, so that he then on the lateral area 17 incident, where there is also a prism, which is designed so that a refraction of this light beam 22 Upwards to the ceiling occurs. Such a proportion of the emitted light thus contributes to a brightening of the ceiling area surrounding the luminaire and forms an indirectly emitted light component.

The light beam 23 is from the lamp 12 initially directed downwards and first meets the counter reflector 14 so he is pointing up to the main reflector 11 is distracted. On this he meets in a relatively steep angle and is there reflected accordingly and deflected downwards, where he on the prismatic plate 13 meets and is broken there, finally to exit right down out of the lamp.

The light beam 24 on the right side in the drawing occurs at a shallower angle from the lamp 12 Starting to the right, so that he at the counter reflector 14 radiates over and at a comparatively shallow angle on the prism plate 13 meets and is reflected there due to the total reflection. This ray of light 24 then apply to the above 2 described lateral area 17 The prism cover and is there broken and deflected upward to the ceiling.

The quasi horizontal of the lamp 12 to the right radiated light beam 25 immediately hits the lateral area 17 the primer cover is broken there and also exits upwards towards the ceiling. These statements show that the luminaire according to the invention by reflector 11 and counter reflector 14 achieved a light deflection, which leads to a desired light emission characteristic, on the one hand a directional radiation is achieved by with specific glare and on the other hand, a brightening of the ceiling surrounding the ceiling of the ceiling.

The following is with reference to the 4 and 5 another advantage of the lamp according to the invention explained. 4 shows a variant of the lamp, which is designed as a surface-mounted luminaire, in which the housing has a base body 26 includes. Within this body 26 is located in the lower inner region a circumferential in cross-section U-shaped angle frame 27 whose lower horizontal leg 27a as a support for the prism plate 13 can serve.

It is advantageous that you have the same basic body in principle 26 also for a variant of the luminaire according to 5 can use, in which this is designed as a ceiling light. In this case, one uses on the outside of the vertical part of the main body 26 to be attached Z-angle 28 whose upper horizontal inward pointing leg 28b on the body 26 rests and the lower horizontal outwardly facing leg 28a under the blanket 15 engages, in which the lamp is installed. In this way, it is possible with relatively simple means and minor changes the housing body 26 to use a ceiling-mounted luminaire also for a recessed ceiling luminaire.

10

luminaire housing

11

main reflector

12

Fluorescent Lamp

13

prism plate

14

retroreflex

14a

middle section

14b c

lateral leg

15

blanket

16

prism cover

17

lateral areas

18

beam of light

19

beam of light

20

beam of light

21

beam of light

22

beam of light

23

beam of light

24

beam of light

25

beam of light

26

body

27

Winkelrahmen

28

Z-angle

28a

lower horizontal thigh

28b

upper horizontal thigh

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 20321097 U1 [0003]
• WO 00/50806 A1 [0005]

Cited non-patent literature

• - DIN EN 12464-1 [0004]

Claims (13)

Luminaire with a luminaire housing, and at least one longitudinally extending elongate luminous means, wherein at least a portion of the luminaire is covered at the bottom by a partially translucent prismatic plate and below at least one illuminant at least one opaque cover is provided which direct light emission from the Illuminant directly downwards prevented, characterized in that at least one light source ( 12 ) is arranged approximately in the central region of the lamp and below this illuminant at least one counter reflector ( 14 ), which directs a part of the luminous flux emitted by the luminous means to a main reflector ( 11 ) and that reflected light from this main reflector through the prism plate ( 13 ) through downwards out of the luminaire. Luminaire according to claim 1, characterized in that the width of the counter-reflector ( 14 ) only a fraction of the width of the main reflector ( 11 ) and / or the prism plate ( 13 ) having. Luminaire according to claim 1 or 2, characterized in that the lighting means ( 12 ) a comparatively small distance to the main reflector ( 11 ) and the counter reflector ( 14 ) Has at least one laterally outer to the horizontal downwardly angled or curved leg. Luminaire according to one of claims 1 or 2, characterized in that the lighting means ( 12 ) a comparatively larger distance to the main reflector ( 11 ) and the counter reflector ( 14 ) Has at least one laterally outer to the horizontal upwardly angled or curved leg. Luminaire according to one of claims 1 to 4, characterized in that it is designed as a surface-mounted luminaire or recessed ceiling luminaire and the main reflector ( 11 ) on the underside by a flat prism plate ( 13 ) is covered. Luminaire according to one of claims 1 to 4, characterized in that it is designed as a ceiling luminaire and the underside of the lamp by a trough-shaped or in cross-section U-shaped prism cover ( 16 ) which covers the prism plate ( 13 ). Luminaire according to one of claims 1 to 6, characterized in that the main reflector ( 11 ) is formed parabolic in cross-section. Luminaire according to claim 6, characterized in that a lateral area ( 17 ) of the trough-shaped or U-shaped prism cover ( 16 ) has a different prism structure than the prism plate ( 13 ) comprehensive remaining area of the prism cover. Luminaire according to one of claims 1 to 8, characterized in that the prism plate ( 13 ) has a preferably rectangular or acute-angled triangular prismatic profile structure extending in the lamp longitudinal direction or a preferably pyramidal prismatic profile structure extending in the lamp longitudinal direction and transverse direction. Luminaire according to claim 8, characterized in that the lateral area ( 17 ) has a sawtooth prism profile structure. Luminaire according to one of claims 1 to 10, characterized in that the prism plate ( 13 ) has a comparatively sharp-edged prism profile structure. Luminaire according to one of claims 6 to 11, characterized in that by the trough-like or U-shaped prism cover ( 16 ) laterally emerging light component is deflected by the prismatic structure toward the ceiling. Luminaire according to one of claims 1 to 12, characterized in that one of the fluorescent lamp ( 12 ) downwards emerging portion of the luminous flux at the counter reflector ( 14 ) passing through the prism plate at shallower angles ( 13 ) down through the luminaire without first reaching the main reflector ( 11 ) to fall.