EP1883099A2

EP1883099A2 - Lighting device with a compact structure

Info

Publication number: EP1883099A2
Application number: EP07108120A
Authority: EP
Inventors: Gian Pietro Beghelli
Original assignee: Beghelli SpA
Current assignee: Beghelli SpA
Priority date: 2006-05-19
Filing date: 2007-05-14
Publication date: 2008-01-30
Also published as: EP1883099A3; CN101076212A; ITVI20060153A1

Abstract

A lighting device with a compact structure, of the type comprising a light source of the fluorescent type (12) coupled with a light source of the incandescent or halogen type (13), having an adequate power, so as to obtain a twofold contribution in immediately reaching the emission of a satisfactory light flow; once the nominal flow has been reached, an electronic circuit interrupts the power supply to the incandescent or halogen light source (13), so that the current absorptions and light flow are those characteristic of the fluorescent light source (12). In practice, the lighting device according to the invention allows optimum lighting levels to be reached immediately (typical characteristic of an incandescent light source), at the same time with a reduced consumption, a considerable energy saving and long functioning life (typical characteristics of a fluorescent light source).

Description

The present invention relates, in general, to a lighting device with a compact structure, and also with immediate lighting and a high energy saving.
In particular, the invention relates to a compact fluorescent lamp to which an incandescent or halogen light source is added to improve the lighting time and average life duration.
Energy-saving fluorescent lamps of the "CFL" type are becoming increasingly more widely diffused on the market, thanks to the high performances which they are capable of reaching; in particular, these lamps are capable of allowing a good 80% energy saving with the same light flow emitted and also the useful life of "CFL" energy saving fluorescent lamps can increase by as much as 10 times with respect to traditional lamps.
The only negative characteristics of these products, from the point of view of their performances, relate to the chromatic yield index, which is lower than normal incandescent or halogen light bulbs, and above all the heating time necessary for reaching the nominal light emission.
As far as the chromatic yield is concerned, this can be solved by intervening on the formulation of fluorescent powders used for transforming the ultraviolet radiations inside the tube into visible emission; at the cost of a slight reduction in efficiency, it is in fact currently possible to obtain a chromatic yield comparable to that of halogen lamps (CR>95) .
The problem relating to the heating time (or Run-Up time) however, is by far the most troublesome and this fact in practice relegates the use of this type of lamps to applications which envisage a prolonged continuative lighting time (such as the illumination of gardens).
Figure 1 enclosed shows, for illustrative purposes, the trend of the light flow F in relation to the time t, revealed on an energy-saving light bulb of the 20 W "CFL" type.
From the graph it can be seen that it takes almost 5 minutes to reach a nominal light flow emission, whereas the initial light flow emitted is equal to about 25%, with respect to the nominal value.
This effect is particularly unwelcome, especially in places where the permanence time of the user is short, for example bathrooms, corridors, landings, etc.
An objective of the present invention is therefore to overcome the above drawbacks and, in particular, to provide a lighting device with a compact structure, which has a substantially limited consumption and which therefore allows a high energy saving and which, at the same time, allows the nominal lighting level, which is a typical characteristic of incandescent light sources, to be reached almost immediately.
A further objective of the present invention is to provide a lighting device with a compact structure, with immediate lighting and high energy saving, which is also extremely safe and highly reliable.
Another objective of the invention is to provide a lighting device with a compact structure at substantially reduced costs, in view of the advantages obtained.
These and other objectives are achieved by a lighting device with a compact structure, according to claim 1 enclosed; further detailed characteristics of the device are described in the subsequent claims.
The invention advantageously envisages combining an incandescent or halogen light source having a suitable power with a fluorescent light source, in order to obtain a twofold contribution in immediately reaching a satisfactory light flow equal to about 80% of the nominal value.
Incandescent or halogen light sources, in fact, reach a nominal emission in a few ms. and also produce a considerable quantity of heat.
By combining the two light sources in a single body it is therefore possible to obtain an immediate light supply upon lighting, an accelerated heating of the lighting device and a consequent reduction in the Run-up time.
Further objectives and advantages of the present invention will appear more evident from the following description, referring to a preferred illustrative but non-limiting embodiment of the lighting device having a compact structure, according to the invention, and from the enclosed drawings, wherein:

figure 1 shows, in a Cartesian graph, the trend of the light flow emitted, in relation to the time, revealed on a 20 Kw energy-saving fluorescent light bulb, of the traditional type;
figure 2 shows, in a Cartesian graph, the trend of the light flow emitted, in relation to the time, revealed on a standard fluorescent lamp, on a halogen lamp and on the lighting device with a compact structure, object of the present invention;
figure 3 is a perspective view of a first possible embodiment of the lighting device with a compact structure, according to the present invention;
figure 4 is a side view of the lighting device with a compact structure as per figure 3, according to the present invention;
figure 5 is a transversal sectional view, along the line V-V of figure 4;
figure 6 is a perspective view of a second possible embodiment, alternative to that of figure 3, of the lighting device with a compact structure, according to the present invention;
figure 7 is a side view of the lighting device with a compact structure as per figure 6, according to the present invention;
figure 8 is a transversal sectional view, along line VIII-VIII of figure 7.

With particular reference to figure 2 above, this shows an experimental graph relating to the trend, with time, of the light flow (reference FL1) emitted from a lighting device with a compact structure, produced according to the present invention, and compared with the trends of the light flow emitted from a standard energy-saving fluorescent lamp (reference FL2) and a halogen lamp (reference FL3) respectively.
The experimental result shown in figure 2 is obtained by producing the lighting device with a compact structure, object of the invention, according to a first constructive embodiment, which is shown in detail in figures 3, 4 and 5 enclosed. As can be seen in these figures, the embodiment proposed is to envisage the use of two lamps assembled on a single central containment structure 10, in support of the lower electric contact 11.
In particular, above the central structure 10, there is a shaped fluorescent tube 12 on the outside, and an incandescent or halogen lamp 13, equipped with an outer bulb 14 and internal filament 15, is installed more internally and centrally with respect to the tube 12.
This is the simplest structure that can be produced and allows an immediate light supply to be obtained upon lighting and an accelerated heating of the device, with a consequent reduction in the Run-up time.
Once the nominal flow has been reached, an electronic circuit situated inside the structure 10 interrupts the power supply to the incandescent or halogen lamp 13, so that at this point both the current absorptions and light flow are those characteristic of the fluorescent source (tube 12).
In practice, in this way, the advantages of the incandescent or halogen sources are combined with those of the fluorescent sources, as the lighting device according to the invention allows the nominal lighting levels (typical characteristic of the incandescent or halogen source 13) to be reached immediately and, at the same time, with a reduced consumption with respect to the other types of light sources, and a consequent energy saving and long functioning period (typical characteristics of the fluorescent tube 12).
The graph of figure 2 shows, in fact, that the lighting device according to the invention immediately reaches 80% of the nominal flow (reference FL1).
The subsequent light oscillation of the device after reaching the nominal flow emission (reference FL1), cannot be substantially perceived with the human eye as it is negligible with respect to the basic component; this component however can also be totally eliminated, by possibly introducing a more sophisticated control in the electronic circuit present inside the containment structure 10.
An alternative embodiment, which is more complicated but less costly and more effective with respect to that described above, is illustrated in detail in figures 6, 7 and 8 enclosed and envisages the fluorescent light source (tube 12) and the incandescent or halogen light source 13 inside a single cap 16, which acts as a containing element for the fluorescent tube or coil 12 and is also functional for the filament 15 of the incandescent or halogen lamp 13, in that it ensures the formation of the vacuum necessary for the functioning of the above incandescent or halogen filament.
This second embodiment, also complete with an electronic circuit suitable for interrupting the power supply to the incandescent or halogen lamp 13, once the nominal light flow emission has been reached, can also guarantee a more rapid establishment of the operating temperature.
The characteristics of the lighting device with a compact structure, with immediate lighting and high energy saving, object of the present invention, are evident from the description, as also the advantages.
Finally, embodiment variants can obviously be applied to the lighting device in question, included in the principles which form the basis of the inventive concept. In the practical embodiment of the invention, the materials, forms and dimensions can also be selected according to technical requirements.

Claims

A lighting device with a compact structure, of the type comprising a containment and supporting structure (10), to which at least one element is connected, which acts as an electric contact (11), characterized in that at least one light source of the fluorescent type (12) and at least one light source of the incandescent or halogen type (13), having a suitable power, are connected to said electric contact (11) in order to immediately reach a satisfactory light flow for the user, upon lighting.
The lighting device according to claim 1, characterized in that said light source of the fluorescent type (12) and said light source of the incandescent or halogen type (13) can be coupled and joined in a single body.
The lighting device according to claim 1, characterized in that said light source of the fluorescent type (12) consists of a fluorescent tube or coil.
The lighting device according to claim 1, characterized in that said incandescent or halogen light source (13) consists of an incandescent light bulb.
The lighting device according to claim 1, characterized in that fluorescent source (13) is situated outside and said incandescent or halogen light source (13) is positioned inside and centrally with respect to said fluorescent light source (12).
The lighting device according to claim 4, characterized in that incandescent light bulb has an outer bulb (14) and at least one inner filament (15).
The lighting device according to claim 1, characterized in that said containment and supporting structure (10) contains an electronic circuit, suitable for interrupting the power supply to said incandescent or halogen light source (13), once the lighting device has reached a nominal light flow, after lighting.
The lighting device according to claim 1, characterized in that, upon lighting, a nominal light flow emission of at least 80% is obtained.
The lighting device according to claim 1, characterized in that said fluorescent light source (12) and said incandescent or halogen light source (13) are contained inside at least one single cap (16), which acts as a containing element for said fluorescent light source (12) and is also functional for creating the vacuum necessary for the functioning of said light source of the incandescent or halogen type (13).
The lighting device according to claim 9, characterized in that said containment and supporting structure (10) contains an electronic circuit, suitable for interrupting the power supply to said incandescent or halogen light source (13), once the lighting device has reached a nominal light flow, after lighting.