A DEVICE FOR USE WITH AN ILLUMINATED SURFACE, PREFERABLY AN ELECTRIC SIGN

Abstract: A device for use with an illuminated surface, preferably an electric sign, comprises several light-emission diodes (8) positioned adjacent and connected with said surface (4). In order to provide a scattering of the light of the light-emission diodes (8) each light-emission diode is enclosed in a light-scattering lense (10) to which there is connected a mounting element (12) by means of which the unit consisting of the light-emission diode and the lense is connected with said surface.

Description: A device for use with an illuminated surface, preferably an electric sign. The present invention relates to a device for use with an illuminated surface, preferably an electric sign. Recently it has become common to use light-emission diodes instead of fluorescent tubes as light sources in connection with the type of illuminated surfaces which constitute electric signs for advertising and other purposes. The use of light-emission diodes for this purpose offers many and substantial advantages. Thus, the light-emission diodes provide for a substantially improved reliability and substantially reduced energy consumption. The light-emission diode has a life of a couple of hundred thousands of hours which is several times more than the life of fluorescent tubes. In addition thereto the strength of the light-emission diode is quite superior to the strength of conventional light sources. A further advantage is that the light-emission diodes offer substantially larger possibilities of designing an electric sign in the desired way. In this respect the use of fluorescent tubes provide substantial restrictions. The use of light-emission diodes as light sources in connection with electric signs requires a scattering of the light emitted by the light- emission diode. In order to provide this scattering of the light it is previously known to position each light emission diode in an opening at the center of a substantially semi-spherical depression provided in the sign, the surfaces of the semi-spherical depressions constituting reflectors scattering the light emitted by the light- emission diodes positioned therein. For providing a normal electric sign there is required a large number of light-emission diodes and a corresponding number of light-reflecting depressions. Thus, it is a time consuming and laborious operation to provide the light- reflecting depressions making the operation expensive and requiring the use. of compl icated and special machi nery in order to provide a satisfactory resul t. In order to obviate the drawbacks described above it is previously known to provide each l ight-emission diode in a separate reflector element comprisi ng a semi -spherical depression and to mount the units consisti ng of l ight-emission diodes and reflector elements in an opening in a surface formed by a plate or a wal l in a desi red pattern to provide the intended electric sign. It is a drawback of the lastmentioned type of device that the units consisting of reflector elements and light-emission diodes constitute complicated and expensive devices . A common drawback of the previously known devices both comprising reflectors in the form of semi -spherical depressions is that there is col lected dirt, snow and ice in said depressions preventing the desired scattering of the l ight of the l ight-emission diodes . The object of the invention is to provide an improved device -for use with an illuminated surface, preferably an electric sign. In order to comply with this object the device according to the invention is characterized in that each light-emission diode is enclosed in a light scattering lense which is connected with a mounting element by means of which the unit comprising the light- emission diode and the lense is connected with said surface. Thus, the device according to the invention does not require any reflector for scattering the light of the light-emission diodes, the above drawbacks of reflectors described above being thereby obviated. The units comprising light-emission diodes and light scattering lenses can be connected with the desired surface by means of their mounting elements in an extremely simple, rapid and reliable way. Preferably the lense and the mounting element constitute one unit and the mounting element is adapted to be introduced in and fastened in an opening in the surface to be illuminated. It is thereby preferred that the surface is constituted by one side of a board or plate and that the opening extends through said board or plate. There¬ by, the mounting element is formed so as extend through and project from the board or plate at the side thereof opposite from the illuminated side of the board or piate_ the mounting element being thereby retained in a simple way by means of a locking element engaging the side of the board or plate opposite from the illuminated side thereof. Due to the invention it is possible to provide electric signs without any special machinery or special knowledge by obtaining the desired number of the units comprising light-emission diodes, lenses and mounting elements and mounting the units in openings formed in a sign plate. The openings of the sign plate can of course be provided by means of conventional drilling equipment. In a device according to the invention the light-emission diodes are protected by the lenses enclosing the light-emission d ' iodes for which reason the device according to the invention have an extraordinary strength. The lenses treat the light of the light-emission diodes in a more efficient way than the reflectors used according to the previously known technique which together with the fact that the lenses less easily get dirty than the previously known reflectors provide that the light yield of a device according to the invention is substantial¬ ly higher than the light yield of the previously known devices. ' By colouring the lenses it is in the device according to the invention possible to provide light having substantially higher colour intensity than in the previously known devices. The invention is described in the following with reference to the accompanying drawing. Fig. 1 shows a device according to the invention in the form of an e.ectric sign shown in plan view. Fig. 2 -is a section on line 11—11 of Fig. 1 on an enlarged scale. Fig. 3 is a detail of an element of the device according to the invention. In Fig. 1 there is shown an electric sign comprising a plate 2 having an illuminated surface 4 within the areas of the letters T and L. The illumination of the surface 4 is provided by means of several luminous units 6 positioned within the area of said letters. As is most clearly shown in Fig. 2 each luminous unit 6 consists of a light-emission diode 8, a lens 10 enclosing the light-emission diode and a mounting element 12 formed in one unit with the lense 10. The mounting element 12 of each luminous unit 6 extends through a through opening 14 provided in the plate 2. The mounting element 12 has such a length that it extends through its corresponding opening 14 and projects at the side 16 of the plate 2 opposite from the surface 4 thereof. Within the plane of the side 16 the mounting elements 12 are provided with circumferencial grooves for receiving a locking element 18 preferably consisting of a locking ring. By the engagement of the surface of the lense 10 opposite to the surface 4 and the engagement of the locking element 18 with opposite sides of the plate adjacent the corresponding opening 14 there is provided an efficient retaining of the luminous units 6 to the plate 2. Because of the fact that the locking element 18 is of a releasable type it is possible to replace the luminous units 6 if that should be necessary. The light-emission diodes 8 are positioned in recesses 20 provided in the units consisting of the lenses 10 and the mounting element 12. The recesses 20 are sealed by means of a suitable sealing mass 22. The terminals 24 of the light-emission diodes 8 project through the sealing mass 22 and are according to conventional, desired principles connected with a suitable power source. The lense 10 of each luminous unit 6 provides a scattering of the light from the light emission diode of the unit so that each luminous unit 6 forms a luminous point having a diameter corresponding the outer diameter of the lense 10. At a distance the luminous units 6 are regarded as a continuous luminous surface. In order to provide an optimal light scattering the light-emitting chips 26 of the light- emission diodes 8 are preferably positioned in the plane of the surface 4 of the plate 2. It is realized that the device according to the invention offers great advantages with regard to the manufacturing, mounting and utilization. The luminous units 6 are manufactured in a simple way by manufacturing the lenses 10 and the mounting elements 12 as shown in Fig. 3 from a plastic material and by positioning and fixing the light-emission diodes 10 in the recesses 20. The mounting of the luminous units 6 on a plate for forming for example an electric sign is conducted in a simple way by formi g in the plate 2 openings having a suitable diameter with regard to the outer diameter of the mounting element 12 by means of conventional drilling equipment and by connecting the luminous units 6 to the plate by introducing the mounting elements 12 in the opening and securing the mounting elements therein by means of the locking elements 18. With regard to its use the device according to the invention is advantageous with regard to the fact that the light-emission diodes 8 have a completely protected position within the lenses 10 and by the fact that the lenses 10 are less subjected to the collection " of dirt than the reflectors of the previously known devices. The invention can be modified within the scope of the following claims.

Claims: C L A I M S 1. A device for use with an illuminated surface, preferably an electric sign, comprising light-emission diodes positioned in connection with said surface, c h a r a c t e r i z e d in that each light-emission diode (8) is enclosed in a light scattering lense (10) and that a mounting element (12) is connected with the lense, the unit formed by the light-emission diode and the lense being connected with said surface (4) by means of said mounting element (12). 2. A device as claimed in claim 1, c h a r a c t e r i z e d in that the lense (10) and the mounting element (12) are formed in one piece. 2. A device as claimed in claim 1 or 2, c h a r a c t e r i z e d in that the mounting element (12) projects into an opening (14) in the surface (4) and is fixed in said opening. •a 4. A device as claimed in claim 3, wherein the illuminated surface (4) constitutes one side of a board or plate (2) and the opening (14) extends through said board or plate, c h a r a c t e r i z e d in that the mounting element (12) extends through and projects from the board or plate (2) at the side (16) thereof opposite from the illuminated surface and is secured in its mounted position by means of a preferably releasable locking element (18) engaging said side (16). 5. A device as claimed in any of the preceding claims, c h a a c t e r i z e d in that the light-emitting chips (26) of the light-emission diodes (8) are positioned in the plane of the illuminated surface (4).

Inventors: LUNDIN TORSTEN, LUNDIN, TORSTEN
Applicants: LEDEX GMBH
Application year: 1986
Main classification: F21V5
IPC codes: F21K7, F21S8, F21V19, G09F13