(19)
(11) EP 2 642 181 B1

(12) EUROPEAN PATENT SPECIFICATION

(45) Mention of the grant of the patent:
03.02.2016 Bulletin 2016/05

(21) Application number: 13159888.0

(22) Date of filing: 19.03.2013
(51) International Patent Classification (IPC): 
F21S 8/02(2006.01)
F21V 13/10(2006.01)
F21V 7/00(2006.01)

(54)

Reflector for lighting devices comprising means adapted to eliminate lighting unevenness

Reflektor für Beleuchtungsvorrichtungen mit Mitteln zur Eliminierung von Beleuchtungsabweichungen

Réflecteur pour dispositifs d'éclairage comprenant des moyens adaptés pour éliminer l'inégalité d'éclairage


(84) Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(30) Priority: 19.03.2012 IT FI20120057

(43) Date of publication of application:
25.09.2013 Bulletin 2013/39

(73) Proprietor: iGUZZINI ILLUMINAZIONE S.p.A.
62019 Recanati (IT)

(72) Inventor:
  • Gattari, Massimo
    62018 POTENZA PICENA (IT)

(74) Representative: Cinquantini, Bruno et al
Notarbartolo & Gervasi S.p.A. Corso di Porta Vittoria, 9
20122 Milano
20122 Milano (IT)


(56) References cited: : 
EP-A1- 1 916 469
US-A- 5 562 343
DE-U1- 20 015 699
   
       
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description

    Field of the invention



    [0001] The present invention relates to the technical field of lighting devices, and in particular to the technical field of reflectors for lighting devices.

    State of the art



    [0002] Light emission uniformity and evenness are factors of primary importance for lighting devices. Reflectors, diffusers and light emission devices are designed and chosen to obtain specific lighting conditions, also in terms of lighting uniformity and evenness.

    [0003] Such reflectors are disclosed in documents US 5 562 343 A1, EP 1 916 469 A1 and DE 200 15 699 U1.

    [0004] Referring to lighting uniformity and evenness in terms of illumination means evaluating the distribution differences of the density of radiated lumen. The less even is the emission, the more perceivable are irregularities in light distribution, such as light spots or rings or streaks which interrupt the uniformity of the emitted light field on the illuminated surface.

    [0005] For instance, emission evenness faults in terms of illumination may be caused by irregularities of the reflecting surface of the reflector or by the particular conformation of the reflector itself or even by the position and orientation of the light source with respect to the reflector.

    [0006] The latter case is particularly important in the case of lighting devices in which the light source is adjustable or fixed but inclined with respect to the axis of symmetry of the reflector.

    [0007] The part of the emission of the light source which incides on the surface is reflected according to the local inclination of the reflector portion struck by the incident light rays, in accordance with Euclid's' rules according to which the incidence angle is equal to the reflection angle.

    [0008] In the case of mutual inclinations between the axis of the beam emitted by the light source and the axis of rotation of the reflector, reflections may occur such as to cause even very significant irregularities, often comprising streaks or spots of light particularly visible when located on the boundary between the grey area and the light area on said illuminated surface, on the projection of the light beam onto the illuminated surface.

    [0009] This problem becomes even more apparent and urgent in case of lighting devices in which the orientation of the light sources is variable with respect to the axis of symmetry of the reflector. In these cases, it often occurs that the reflections of the light beam on the walls of the reflector itself cause the unevenness shown above as the inclination of the light sources increases towards the ends.

    [0010] For example, figure 2 shows the case in which the orientation of said light sources is such that the main light emission direction is inclined with respect to the axis of rotation of the reflector, part of the reflected light beam, in particular the part related to the reflection on the upper part of the surface of the reflector - closest to the light sources - falls either on the limit or out of the main light cone 15 emitted by the lighting device, causing the streaks and spots of light 16 described above. With reference the aforesaid technical problem, it is therefore an object of the present invention to introduce a new reflector for lighting devices, provided with appropriate means adapted to correct the lighting unevenness faults described above which tend to occur especially in lighting devices in which the orientation of the light sources is variable with respect to the axis of symmetry of the reflector.

    Brief description of the figures



    [0011] 

    Fig. 1 a shows a perspective view of a preferred embodiment of the lighting device comprising the reflector according to the present invention.

    Fig. 1 b shows a section view of a preferred embodiment of the lighting device comprising the reflector according to the present invention.

    Fig. 1 c shows a perspective view of a preferred embodiment of the lighting device comprising the reflector according to the present invention.

    Fig. 2 shows an example of the technical problems underlying the present invention, in the case of a lighting device in which the orientation of said light sources is such that the main direction of light emission is inclined with respect to the axis of rotation of the reflector and a reflected light beam which falls outside the main light cone is present.


    Disclosure of the invention



    [0012] A reflector for flush installed lighting devices, adapted to eliminate possible undesired spots of light and unevenness of the produced light beam, said reflector being provided with a further reflective element, arranged on the surface of said reflector and essentially parallel to the lying plane of the greater opening of said reflector. Said further reflective element will preferably have a circular segment shape and dimensions which may vary according to the dimensions of said reflector and according to the inclination that the lighting assembly may assume with respect to the main body of the flush installed lighting device.

    Detailed description of the invention



    [0013] The appended figures show a typical embodiment of a lighting device for flush installation, comprises: a main body 10 - comprising, in turn, fixing means to a wall 11, a frame 12 adapted to engage an opening in said wall and a reflector 13 - and a lighting assembly 20, comprising, in turn, light sources 21 associated to possible thermal dissipation means 22, said lighting assembly 20 being associated to said main body 10 so that the mutual inclination thereof may be modified within two limit positions.

    [0014] Said reflector 13 is of the rotationally symmetrical type - i.e. characterized by a rotational symmetry about an axis of rotation - and is provided with an apex comprising a first opening of such dimensions to enable the entrance of the luminous flux emitted by said light sources 21 and a second opening, of greater dimensions than the first opening, adapted to let out the direct light emitted by said light sources 21 and the light reflected by the inner surface of said reflector 13. Said two openings lay approximately on planes which are inclined to each other by a certain angle α, the plane on which said second opening lies being essentially orthogonal to the axis of rotation of said reflector 13.

    [0015] In this manner, said reflector 13 has a reflective internal surface which has a height varying between a minimum and a maximum at the distance between the lying planes of said first and second openings, and said light sources 21 face the part having greater height of the surface of said reflector 13 when said lighting assembly 20 is inclined with respect to said main body 10.

    [0016] In the aforesaid inclination conditions of said lighting assembly 20 with respect to said main body 10, the reflections of part of the lighting beam emitted by said light sources 21 on a part of the surface of said reflector 13 may cause the unevenness illustrated above creating undesired light spots of various shape on the illuminated surface.

    [0017] In order to avoid the aforesaid drawback and eliminate possible portions of the light emission 16 outside the main emission cone 15, said reflector 13 is provided with a further reflective element 14, arranged on said part having greater height of the surface of said reflector 13 and essentially parallel to the lying plane of said second opening.

    [0018] Said further reflective element 14 will preferably be circular segment shaped, and have dimensions which may vary according to the dimensions of said reflector 13 and according to the inclination that said lighting assembly 20 may assume with respect to said main body 10, and will have the same surface finish of said reflector 13. Furthermore, said further reflective element 14 will be preferably positioned at a height which is closer to said first opening with respect to said second opening.

    [0019] During the operation of the lighting device, said further reflective element 14 advantageously reflects a portion of the light flux emitted by said light sources 21 - as shown in appended figure 1b) - so as to prevent said portion of light flux from being reflected outside the main lighting cone 15 causing undesired spots of light 16 and unevenness of the produced lighting.


    Claims

    1. A reflector (13) of rotationally symmetrical type for lighting devices comprising: a first opening of such dimensions to enable the entrance of the luminous flux emitted from the light sources of said lighting devices; a second opening, of greater dimensions than the first opening, adapted to let out the direct light emitted by said light sources and that reflected by the internal surface of said reflector (13), said two openings approximately lying on planes which are inclined to each other by a certain angle α and the plane on which said second opening lies being substantially orthogonal to the axis of rotation of said reflector; a reflective internal surface which has a height varying between a minimum and a maximum in correspondence to the distance which runs between the planes on which said first and said second openings approximately lie, characterized in that it comprises a further reflective element, (14) arranged on said part having a greater height of the surface of said reflector (13) and substantially parallel to the lying plane of said second opening.
     
    2. The reflector (13) according to claim 1, wherein said further reflective element (14) has a circular segment shape.
     
    3. The reflector (13) according to claim 1, wherein said further reflective element (14) has the same surface finish as said reflector 13.
     
    4. The reflector (13) according to claims 1, wherein said further reflective element (14) is positioned at a height which is nearer to said first opening with respect to said second opening
     
    5. A lighting device for flush installation comprising: a main body (10)

    - comprising, fixing means (11) for fixing to a wall and a frame (12) adapted to engage an opening in said wall - and a lighting assembly (20) comprising, light sources, (21) said lighting assembly being associated with said main body so that the mutual inclination thereof may be modified within two limit positions characterized in that said main body (10) further comprises a reflector (13) according to claim 1.


     
    6. The lighting device for flush installation according to claim 5, characterized in that said lighting device (20) is associated with said main body (10) so that the orientation of said light sources is such that the main direction of light emission is inclined with respect to the axis of rotation of the reflector.
     
    7. Lighting device according to claim 5, wherein said light sources are associated with possible thermal dissipation means.
     


    Ansprüche

    1. Reflektor (13) vom rotationssymmetrischen Typ für Beleuchtungsvorrichtungen, wobei der Reflektor umfasst: eine erste Öffnung von solchen Dimensionen, die den Eintritt des von den Lichtquellen der genannten Beleuchtungsvorrichtungen emittierten Lichtflusses ermöglichen; eine zweite Öffnung von größeren Dimensionen als die erste Öffnung, die dafür ausgelegt ist, das durch die genannten Lichtquellen emittierte und das durch die Innenoberfläche des genannten Reflektors (13) reflektierte direkte Licht herauszulassen, wobei die genannten zwei Öffnungen näherungsweise in Ebenen liegen, die um einen bestimmten Winkel α gegeneinander geneigt sind, und wobei diejenige Ebene, in der die genannte zweite Öffnung liegt, im Wesentlichen orthogonal zu der Rotationsachse des genannten Reflektors ist; eine reflektierende Innenoberfläche, die eine Höhe aufweist, die entsprechend der Entfernung, die zwischen den Ebenen verläuft, in denen näherungsweise die genannte erste und die genannte zweite Öffnung liegen, zwischen einem Minimum und einem Maximum variiert, dadurch gekennzeichnet, dass der Reflektor ein weiteres reflektierendes Element (14) umfasst, das an dem genannten Teil mit einer größeren Höhe der Oberfläche des genannten Reflektors (13) angeordnet ist und das zu der Liegeebene der genannten zweiten Öffnung im Wesentlichen parallel ist.
     
    2. Reflektor (13) gemäß Anspruch 1, wobei das genannte weitere reflektierende Element (14) eine Kreissegmentform aufweist.
     
    3. Reflektor (13) gemäß Anspruch 1, wobei das genannte weitere reflektierende Element (14) dieselbe Oberflächenbeschaffenheit wie der genannte Reflektor 13 aufweist.
     
    4. Reflektor (13) gemäß den Ansprüchen 1, wobei das genannte weitere reflektierende Element (14) in einer Höhe positioniert ist, die der genannten ersten Öffnung in Bezug auf die genannte zweite Öffnung näher ist.
     
    5. Beleuchtungsvorrichtung für bündigen Einbau, wobei die Beleuchtungsvorrichtung umfasst: einen Hauptkörper (10), der - Befestigungsmittel (11) zum Befestigen an einer Wand und einen Rahmen (12), der dafür ausgelegt ist, mit einer Öffnung in der genannten Wand in Eingriff zu gelangen, umfasst

    - und eine Beleuchtungsanordnung (20), die Lichtquellen (21) umfasst, wobei die genannte Beleuchtungsanordnung dem genannten Hauptkörper in der Weise zugeordnet ist, dass die gegenseitige Neigung davon innerhalb zweier Grenzpositionen geändert werden kann, dadurch gekennzeichnet, dass der genannte Hauptkörper (10) ferner einen Reflektor (13) gemäß Anspruch 1 umfasst.


     
    6. Beleuchtungsvorrichtung für bündigen Einbau gemäß Anspruch 5, dadurch gekennzeichnet, dass die genannte Beleuchtungsvorrichtung (20) dem genannten Hauptkörper (10) in der Weise zugeordnet ist, dass die Orientierung der genannten Lichtquellen derart ist, dass die Hauptrichtung der Lichtemission in Bezug auf die Rotationsachse des Reflektors geneigt ist.
     
    7. Beleuchtungsvorrichtung gemäß Anspruch 5, wobei den genannten Lichtquellen mögliche Wärmeableitmittel zugeordnet sind.
     


    Revendications

    1. Réflecteur (13) de type rotativement symétrique pour dispositifs d'éclairage comprenant : une première ouverture aux dimensions telles qu'elle permet l'entrée du flux lumineux émis depuis les sources de lumière desdits dispositifs d'éclairage ; une seconde ouverture, aux dimensions supérieures à celles de la première ouverture, adaptée pour laisser sortir la lumière directe émise par lesdites sources de lumière et qui est réfléchie par la surface interne dudit réflecteur (13), lesdites deux ouvertures se trouvant approximativement sur des plans qui sont inclinés l'un par rapport à l'autre d'un certain angle α et le plan sur lequel se trouve ladite seconde ouverture étant sensiblement orthogonal à l'axe de rotation dudit réflecteur ; une surface interne réfléchissante qui a une hauteur variant entre un minimum et un maximum en correspondance avec la distance qui s'étend entre les plans sur lesquels se trouvent approximativement lesdites première et seconde ouvertures, caractérisé en ce qu'il comprend un élément réfléchissant supplémentaire (14) agencé sur ladite partie ayant une hauteur supérieure de la surface dudit réflecteur (13) et sensiblement parallèle au plan de repos de ladite seconde ouverture.
     
    2. Réflecteur (13) selon la revendication 1, dans lequel ledit élément réfléchissant supplémentaire (14) a une forme de segment circulaire.
     
    3. Réflecteur (13) selon la revendication 1, dans lequel ledit élément réfléchissant supplémentaire (14) a le même fini de surface que ledit réflecteur (13).
     
    4. Réflecteur (13) selon la revendication 1, dans lequel ledit élément réfléchissant supplémentaire (14) est positionné à une hauteur qui est plus proche de ladite première ouverture par rapport à ladite seconde ouverture.
     
    5. Dispositif d'éclairage pour installation à fleur comprenant : un corps principal (10) comprenant un moyen de fixation (11) pour fixation à un mur et un cadre (12) adapté pour entrer en prise avec une ouverture dudit mur, et un ensemble d'éclairage (20) comprenant des sources de lumière (21), ledit ensemble d'éclairage étant associé audit corps principal de sorte que l'inclinaison mutuelle de ceux-ci puisse être modifiée dans deux positions limites caractérisé en ce que ledit corps principal (10) comprend en outre un réflecteur (13) selon la revendication 1.
     
    6. Dispositif d'éclairage pour installation à fleur selon la revendication 5, caractérisé en ce que ledit dispositif d'éclairage (20) est associé audit corps principal (10) de sorte que l'orientation desdites sources de lumière soit telle que la direction principale d'émission de lumière est inclinée par rapport à l'axe de rotation du réflecteur.
     
    7. Dispositif d'éclairage selon la revendication 5, dans lequel lesdites sources de lumière sont associées à des moyens de dissipation thermique possibles.
     




    Drawing











    Cited references

    REFERENCES CITED IN THE DESCRIPTION



    This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

    Patent documents cited in the description