WO2003017240A1

WO2003017240A1 - A system and a method for illuminating an advertising sign as well as a modular unit for use in a system for illuminating an advertising sign

Info

Publication number: WO2003017240A1
Application number: PCT/SE2002/001467
Authority: WO
Inventors: Dennis Tyronne Gustavsson
Original assignee: Elektro Vakuum Produktion Arjäng Aktiebolag
Priority date: 2001-08-17
Filing date: 2002-08-19
Publication date: 2003-02-27
Also published as: SE523880C2; SE0102763D0; SE0102763L

Abstract

The present invention relates to a system for illuminating a sign, comprising a housing (1) with an outer contour of a symbol such as a number or a letter, for example; two or more lamps (2) arranged in the housing (1); a source (3) of mains voltage; a lead (13) that connects the mains voltage source (3) to the lamps (2) and a transformer (4) arranged betweeen the mains voltage source (3) and the lamps. The lamps (2) consist of subminiature lampe (2) to a voltage that is below the voltage from the mains voltage source (3), so that the lamps (2) are supplied with a voltage that is below the voltage from the mains voltage source (3). The invention also relates to a method for illuminating a sign, in which method a mains voltage is transformed down and supplied to incandescent lamps placed in a housing. The invention also relates to a modular unit intended for use in the system according to the invention, which modular unit (5) comprises subminiature lamps (2).

Description

A SYSTEM AND A METHOD FOR ILLUMINATING AN ADVERTISING SIGN AS WELL AS A MODULAR UNIT FOR USE IN A SYSTEM FOR ILLUMINATING AN ADVERTISING SIGN

TECHNICAL FIELD

The present invention relates to a system for illuminating a sign, comprising a housing with the outer contour of a symbol, such as a number or a letter, for example; lamps arranged in the housing; a source of mains voltage and a lead that connects the mains voltage source to the lamps. The invention also relates to a method for illuminating a sign and a modular unit intended for use in a system for illuminating a sign.

BACKGROUND

Systems for sign illumination are used for example as billboards for the daily papers, general information on roads, price information at petrol stations and at sporting events. Examples of systems for sign illumination are described for example in US patent specification 4488090 and US patent specification 5365411, The first-named document, US 4488090, shows a sign illumination system in which a source of mains voltage has been placed inside a building. The mains voltage is transformed down to a low voltage, which it is stated can be between 16 and 24 volts. The voltage is transformed down in this case by means of a transformer situated inside the building. The voltage, thus reduced, is then routed out of the building and on to a housing for a display sign, which housing contains a lighting element for high voltage, such as a neon tube, for example. In the housing, the voltage is then transformed up to a higher voltage, which it is stated can be up to 15000 volts. As a reason for choosing this solution, it is stated that it is thereby possible to use finer cables (leads) out through the walls of the building, so that smaller holes can be drilled in the wall, and that the lower voltage that is used does not expose people to the risk of being affected by an electric shock. However, it can be said regarding neon tubes that such elements are expensive. Furthermore, it is the case that it is not possible to create extreme configurations in any way one likes using neon tubes, amongst other things the tubes cannot be made as slender as one likes or be curved too sharply.

The last-named document, US 5365411, shows a sign illumination system in which a voltage source has been connected to a lighting unit that contains light diodes. In US 5365411, it is shown how alternating voltage is transformed down to direct-current voltage and reduced from a higher to a lower level so that the lighting unit and its diodes are supplied with reduced direct-current voltage. If necessary, battery operation with direct- current voltage can be used. As a reason for the choice of diodes, it is stated that diodes require less power compared with fluorescent lamps (neon tubes) and incandescent lamps. Further stated advantages of diodes are that they emit less heat and have a long service life. However, it is stated that diodes can result in a large number of light points, even if a light- diffusing element is used. As a consequence of this, a large number of diodes must be used. To avoid the problem, it is proposed that the lighting unit is arranged in such a way that the diodes are arranged so that they may emit their light towards a shield, which reflects the light against a rear wall, which in turn transmits the light further through a light-diffusing element It is stated that, due to the special design of the rear wall, the effect can be achieved that the light reflected from the rear wall has an even intensity. The system proposed in US patent specification 5365411 offers a possibility of using low voltage. However, a relatively complicated construction of the conversion unit used to reduce and rectify the current is required. Furthermore, it has proved necessary to use a reflecting shield and rear wall of a special design to obtain sufficient light diffusion. This sets a lower limit for the cost of the system.

OBJECT OF THE INVENTION The object of the present invention is to supply a system for sign illumination that is simple and of low cost. A further object of the invention is to supply a sign illumination that can be used without risk of accidents and preferably can also be installed by personnel who lack any special training. The invention also aims to supply a sign illumination that is flexible and capable of easily reproducing various messages and symbols. The invention also aims to supply a sign illumination that is sturdy and can be used regardless of the weather, season or climate. Another object of the invention is to supply a sign illumination with a long life. A further object is to supply a sign illumination that provides a uniform, pleasant light. It is also an object of the invention to supply a sign illumination that has a low content of environmentally hazardous substances, so that the impact on the environment can be minimized. The object of the invention is also to supply a method and a modular unit, which method and modular unit are suitable for use in connection with the system according to the invention for sign illumination and can be used both for forward- and backward-radiating illumination. Backward-radiating illumination refers to lighting that is directed backwards to be reflected against the background where the sign sits, so-called "corona illumination"

DESCRIPTION OF THE INVENTION According to the invention, a system for sign illumination comprises a housing with the outer contour of a symbol, such as a number or letter, for example; two or more lamps arranged in the housing; a source of mains voltage; a lead that connects the mains voltage source to the lamps and a transformer disposed between the mains voltage source and the lamps. The lamps consist of incandescent lamps and the transformer is disposed to convert the voltage entering the transformer to a voltage that is below the voltage from the mains voltage source, so that the incandescent lamps are supplied with a voltage that is below the voltage from the mains voltage source. It is to be understood hereby that the total voltage across the lamps shall be below the voltage from the mains voltage source. In the case of series connection of the lamps, the voltage is distributed over the various lamps so that the voltage across each individual lamp is lower than the total voltage. What is intended is that the total voltage across the lamps is below the voltage from the mains voltage source.

The transformer is suitably disposed to supply the incandescent lamps with alternating current and the incandescent lamps are preferably connected in series. The term "mains voltage" is understood to mean normal domestic electricity, i.e. the mains voltage that is supplied to the public for use in such applications as domestic lighting, TV sets, vacuum cleaners and the like. In Sweden, the mains voltage is adapted to the EU standard, 230 volts and 50 Hz (for three-phase: 400 volts and 50 Hz). In other countries, the mains voltage can be 110 to 120 volts and 60 Hz. The transformer used as an operating device can consist of a copper winding with an iron core, with a primary winding for incoming voltage, for example 230 volts, and a secondary winding for outgoing low voltage. Other choices of material are also conceivable, for example an aluminium winding can be used instead of a copper winding.

In the system according to the invention, the incandescent lamps consist of subminiature lamps. A subminiature lamp is an incandescent lamp intended to be operated using a voltage that is considerably below the normal mains voltage. Suitable voltage across a subminiature lamp should not exceed 6.5 volts, at best the voltage across a subminiature lamp is 6 volts or lower. Such lamps can be obtained for example from Oshino Lamps Limited, Kagoshima, Japan or from Alba Lighting GmbH in Bamberg, Germany. In a subminiature lamp, the incandescent filament is preferably executed in tungsten and the glass in the lamp is at best soft lime glass. Tungsten is a suitable material in the filament, since this material has a high melting point (3655K) and a low evaporation rate at the working temperature of the lamp, i.e. the temperature at which the filament glows and emits light. Dumet, a copper-clad nickel-iron core, is used for the connection and as a support for the electrodes. Molybdenum is preferably used in the support for the incandescent filament. A subminiature lamp can be operated using both alternating current and direct current. However, it has proved to be the case that the life of the lamp is considerably shorter when direct current is used, for which reason it is best to use alternating current. Subminiature lamps have been used hitherto in medical and military applications, among other things. The inventors have now found surprisingly that subminiature lamps can also be used in applications with large dimensions, such as lighting signs, and that good light diffusion and a pleasant light suitable for sign illumination systems can be obtained. In applying the present invention, subminiature lamps such as are described in US patent specification 5 359262 can be used, for example. Subminiature lamps such as are described in US patent specification 5 221 140 can also be used. The content of US patent specification 5 359 262 and US patent specification 5 221 140 shall be understood to form a part of this description.

In a particularly preferred embodiment, the subminiature lamps are arranged in the housing in such a way that they are mounted in a modular unit comprising a first plate and a second plate, which plates are essentially parallel to one another and joined to one another by a spacer, the subminiature lamps being placed in the first plate and directed towards the second plate, which second plate is executed in a translucent material, and the modular unit being placed inside the housing. The term "translucent material" is taken to mean a semi- transparent material that lets light through but diffuses the light so that the objects cannot be distinguished on the other side of the translucent material.

In a first embodiment, the second plate is fastened to a wall and forms an inner plate, the first plate constituting an outer plate to which the subminiature lamps are attached so that the lamps are directed inwards in the direction of the wall to obtain corona illumination. According to a second embodiment of the invention, the housing is hung up on a wall, the modular unit resting inside the housing in such a way that the first plate forms an inner plate situated close to the wall, the second plate constituting an outer plate at a distance from the wall so that the lamps are directed outwards, away from the wall, to obtain forward lighting.

The invention also relates to a method for illuminating a sign, in which a source of mains voltage is provided, a housing with an outer contour of a symbol such as a number or a letter, for example, two or more lamps arranged in the housing and a transformer. A connection is then set up between the lamps and the mains voltage source so that the lamps can be supplied with voltage from the mains voltage source. The lamps consist of incandescent lamps, preferably subminiature lamps, which are connected to the mains voltage source via the transformer. According to the invention, the voltage entering the transformer from the mains voltage source is transformed down to a voltage that is below the voltage from the mains voltage source, so that the lamps are supplied with a voltage that is below the voltage from the mains voltage source.

Alternating current is preferably used so that the subminiature lamps are supplied with alternating current at a voltage that is below the voltage from the mains voltage source.

The invention finally relates to a modular unit intended for use in connection with a system for illuminating a sign, which modular unit comprises a first plate and a second plate, which first and second plate are essentially parallel to one another and joined to one another by a spacer. The first plate is provided here with incandescent lamps, preferably subminiature lamps that are directed towards the second plate to radiate directly towards this. The second plate is executed in a translucent material.

BRIEF DESCRIPTION OF DIAGRAMS

Fig. 1 shows diagrammatically the construction of the system according to the invention for illuminating a sign according to a first embodiment of the invention.

Fig. 2 shows diagrammatically the construction of the system according to the invention for illuminating a sign according to a second embodiment of the invention. Fig. 3 shows the construction of a modular unit for illuminating a sign placed in a housing.

Fig. 4 shows an arrangement comprising a housing and a modular unit, which arrangement is disposed for backward-radiating illumination towards a wall.

Fig. 5 shows an arrangement comprising a housing and a modular unit, which arrangement is disposed for forward-radiating illumination.

Fig. 6 shows some different examples of suitable connection arrangements.

DETAILED DESCRIPTION OF THE INVENTION

The invention shall now be described in greater detail with reference to the enclosed figures. Figure 1 and Figure 2 show a system for illuminating a sign, comprising a housing 1 with the outer contour of a symbol such as a number or a letter; two or more lamps 2 arranged in the housing 1, a source 3 of mains voltage; a lead 13 that connects the mains voltage source 3 to the lamps 2 and a transformer 4 arranged between the mains voltage source 3 and the lamps. The lamps consist of incandescent lamps 2, and the transformer 4 is disposed to convert the voltage entering the transformer 4 to a voltage that is below the voltage from the mains voltage source 3, so that the incandescent lamps 2 are supplied with a voltage that is below the voltage from the mains voltage source 3, i.e. so that the total voltage across the lamps arranged in the housing is below the voltage from the mains voltage source 3. The total voltage across the lamps can naturally be higher than the voltage across each individual lamp. The transformer 4 — the operating device - can be given a very simple design and best consists of a copper winding on an iron core. A very durable operating device is thereby obtained.

In a preferred embodiment, the transformer 4 is disposed to supply the incandescent lamps 2 with alternating current.

According to the invention, the incandescent lamps 2 consist of subminiature lamps 2. A subminiature lamp is an incandescent lamp intended to be operated by a voltage that is considerably below the normal mains voltage. Suitable voltage for a subminiature lamp should not exceed 6.5 volts. Subminiature lamps are now used in medical and military applications, among other things, for example in military equipment for light amplification, and in the aviation industry. Such lamps expediently utilize incandescent filaments of tungsten. Subminiature lamps have relatively good light diffusion. The subminiature lamps now available can have a life of up to 50,000 hours.

The subminiature lamps 2 are suitably connected in series. The lamps are series-connected at best two and two or four and four, so that standard 12 and 24 volt transformers respectively can be used. Suitable voltage across each lamp is 6 volts. As shown in Figure 6, the lamps can naturally also be connected conceivably in another manner, for example three and three.

The subminiature lamps 2 are arranged in the housing 1 in such a way that they are mounted in a modular unit 5 comprising a first plate 6 and a second plate 7, which plates 6, 7 are essentially parallel to one another and joined to one another by a spacer 8. The subminiature lamps 2 are placed in the first plate 6 and directed towards the second plate 7, which second plate 7 is executed in a translucent material, and the modular unit 5 is placed inside the housing 1. The subminiature lamps 2 are preferably glued firmly in holes 14 in the first plate 6, but can also be attached in another way.

According to a first embodiment of the invention, the second plate 7 is attached to a wall 9 and forms an inner plate and the first plate 6 constitutes an outer plate to which the subminiature lamps 2 are attached. The lamps 2 are then directed inwards in the direction of the wall to obtain corona illumination.

According to a second embodiment of the invention, the housing 1 is hung on a wall 9, the modular unit 5 resting inside the housing 1 in such a way that the first plate 6 forms an inner plate situated close to the wall 9 and the second plate 7 constitutes an outer plate at a distance from the wall 9. The lamps 2 are directed outwards, away from the wall, to obtain forward lighting.

The wall 9 can be the wall of a building 10 on which the system according to the invention for illuminating a sign is hung. The building 10 can consist for example of office premises, a restaurant or a garage or other building where a public or private business is operated and one would like to display one's business. In a preferred embodiment of the invention, both the voltage source 3 and the transformer 4 are placed indoors, i.e. inside the building 10. Due to this, the voltage from the voltage source can be already transformed down indoors so that it is possible to work outdoors, where the system is exposed to stresses such as rain for example, exclusively with low voltage.

The method according to the invention for illuminating a sign consequently comprises the following stages: a) supplying a source 3 of mains voltage; b) supplying a housing 1 with an outer contour of a symbol such as a number or letter, for example; c) supplying two or more lamps 2 arranged in the housing 1, which lamps 2 consist of subminiature lamps; d) supplying a transformer 4; e) establishing a connection between the lamps 2 and the mains voltage source 3 in such a way that the lamps 2 are connected to the mains voltage source 3 via the transformer 4; f) the voltage entering the transformer 4 from the mains voltage source 3 is transformed down to a voltage that is below the voltage from the mains voltage source 3 so that the lamps 2 are supplied with a voltage that is below the voltage from the mains voltage source 3.

The mains voltage is preferably transformed down to a level at which the voltage across each lamp (subminiature lamp) amounts to a maximum of 6.5 volts. It is preferable, however, for the voltage to the individual lamps to amount to at least 5 volts. In the case of series connection of the lamps, the voltage will be distributed across the various lamps. According to directives applicable in Sweden, persons without special competence may connect systems with a plug contact to the electricity supply if the system is made for voltage up to 50 volts. It is therefore desirable for the total voltage across the lamps to be below 50 volts. In an even more preferred embodiment, a total voltage across the lamps of below 30 volts is chosen. With reference to Fig. 6, a number of different arrangements are shown in which the voltage across each individual lamp has been selected at 6 volts. In series connection of 4 lamps, the total voltage across the lamps is then 24 volts, thus less than 30 volts. In series connection of 3 lamps, the total voltage across the lamps is 18 volts. The incoming voltage from the mains voltage source is thus transformed down to 18 volts. The lamps (2), which consist of subminiature lamps, are best supplied with alternating current. Alternating current is preferable, as it has proved to be the case that the life of subminiature lamps is reduced by 50% - 70% when direct current is used instead of alternating current.

The modular unit 5 according to the invention that is intended for use in connection with a system for illuminating a sign is most clearly evident from Figures 3, 4 and 5. The modular unit 5 is executed as a sandwich construction and comprises a first plate 6 and a second plate 7, which first and second plates 6, 7 are essentially parallel to one another and joined to one another by a spacer 8. The first plate 6 is provided with incandescent lamps 2, preferably subminiature lamps, which are directed towards the second plate 7 to radiate directly towards this and the second plate 7 is executed in a translucent material. The modular unit according to the invention can also utilize types of incandescent lamps other than subminiature lamps, but subminiature lamps are preferred. Regardless of whether the module according to the invention utilizes subminiature lamps or some other type of incandescent lamp, the module can be applied in a system that is otherwise identical to the system for illuminating a sign described in this application, so that a system with the module according to the invention is obtained.

Figure 3 shows the housing 1 fastened on the modular unit 5 according to the invention, the housing 1 having been secured on the modular unit 5 by fastening organs 11 , suitably . Velcro elements or the like. By means of lead-through holes 12 in one of the plates 6, 7 (or both of the plates), the modular unit 5 can simply be fastened screwed firmly to a wall by screws 15 or attached by other suitable fixing organs 15. This embodiment is intended for forward illumination.

Due to the use of subminiature lamps that are supplied with a voltage that is below the normal mains voltage, it is possible to achieve the following advantages among others. It is possible to avoid high voltage completely, due to which the system according to the invention can also be used by personnel who lack any special training. The transformer can be placed at a distance from the sign and the sign as such does not need to contain any electronics or any operating device. Since both the mains voltage source and the transformer can be placed inside a building, high voltage levels can be avoided entirely outdoors and the system can therefore be used without any risk of personal injury or other accidents in environments where the system is exposed to moisture in the form of rain, dew or other precipitation. The only operating device that is required consists of a transformer 4 that can consist of a copper winding on an iron core. No complicated electronics are then necessary and a simple arrangement costing very little is obtained. The good light diffusion of the subminiature lamp also means that the lamps do not need to be placed as closely as diodes. In spite of the sparser positioning, it is not necessary either to appropriate the arrangement shown in US 5365411 with a reflecting shield and specially designed rear wall. Furthermore, subminiature lamps have a comparatively low content of environmentally hazardous substances, for which reason the invention contributes to minimizing the impact on the environment.

It is perceived that the modular unit according to the invention is reversible and thus carries the advantage that it can be used both for forward-radiating illumination and for corona illumination, i.e. reflecting light towards the background where the sign sits. Since the module can easily be turned both forwards and backwards, it is a flexible component that gives the user greater freedom of choice.

Claims

1. System for illuminating a sign, comprising a housing (1 ) with an outer contour of a symbol such as a number or a letter, for example, two or more lamps (2) arranged in the housing (1); a source (3) of mains voltage; a lead (13) that connects the mains voltage source (3) to the lamps (2) and a transformer (4) arranged between the mains voltage source (3) and the lamps, characterized in that the lamps (2) consist of subminiature lamps (2) and that the transformer (4) is disposed to convert the voltage entering the transformer (4) to a voltage that is below the voltage from the mains voltage source (3), so that the lamps (2) are supplied with a voltage that is below the voltage from the mains voltage source (3).

2. System according to claim 1, characterized in that the transformer (4) is disposed to supply the lamps (2) with alternating current.

3. System according to one of the preceding claims, characterized in that the transformer is disposed to supply the lamps (2) with a total voltage across the lamps that is below 50 volts and preferably with a total voltage across the lamps that is below 30 volts and so that the voltage across each individual lamp does not exceed 6.5 volts.

4. System according to one of the preceding claims, characterized in that the lamps (2) are connected in series.

5. System according to claim 1, characterized in that the subminiature lamps (2) are arranged in the housing (1) in such a way that they are contained in a modular unit (5) comprising a first plate (6) and a second plate (7), which plates (6, 7) are essentially parallel to one another and joined to one another by a spacer (8), the subminiature lamps (2) being placed in the first plate (6) and directed towards the second plate (7), which second plate (7) is executed in a translucent material, and the modular unit (5) being placed inside the housing (1).

6. System according to claim 5, characterized in that the second plate (7) is attached to a wall (9) and forms an inner plate and the first plate (6) constitutes an outer plate to which the subminiature lamps (2) are attached so that the lamps (2) are directed inwards in the direction of the wall to obtain corona illumination.

7 System according to claim 5, characterized in that the housing (1) is hung on a wall (9), the modular unit (5) resting inside the housing (1 ) in such a way that the first plate (6) forms an inner plate situated close to the wall (9) and the second plate (7) constitutes an outer plate at a distance from the wall (9) so that the lamps (2) are directed outwards, away from the wall, to obtain forward lighting.

8 Method for illuminating a sign, which method comprises the following stages: a) supplying a source (3) of mains voltage; b) supplying a housing (1) with an outer contour of a symbol such as a number or letter, for example; c) supplying two or more lamps (2) arranged in the housing (1); d) supplying a transformer (4); e) establishing a connection between the lamps (2) and the mains voltage source (3), characterized in that the lamps (2) are subminiature lamps that are connected to the mains voltage source (3) via the transformer (4) and that the voltage entering the transformer (4) from the mains voltage source (3) is transformed down to a voltage that is below the voltage from the mains voltage source (3) so that the lamps (2) are supplied with a voltage that is below the voltage from the mains voltage source (3).

9. Method according to claim 8, characterized in that the lamps (2) are supplied with alternating current.

10. Modular unit (5) intended for use in connection with a system for illuminating a sign, which modular unit (5) comprises a first plate (6) and a second plate (7), which first and second plates (6, 7) are essentially parallel to one another and joined to one another by a spacer (8), the first plate (6) being provided with incandescent lamps (2), preferably subminiature lamps (2), which are directed towards the second plate (7) to radiate directly towards this and the second plate (7) being executed in a translucent material.