This invention relates to a device that allows e- lectric lamps uuith white or transparent bulb to emit differ- < ^■ 5 ent colours , as a function of the internal covering of the filarηeπt that was selected to be energized.

In this text, to facilitate the description of the invention, lamps uuith one filament divided by taps in sever¬ al segments ujith independent control capability mill be con- ID sidered as having several filaments, one for each independ¬ ent segment.

The colour lamps available presently, does not rna_t ter if intended to application to domestic, artistical, in¬ dustrial, decorative, public way illumination or automotive 15 use produce the effect of colour by passing the light gener¬ ated in the filament through the bulb or glass of the refle tor apparatus, with no means of changing the colour emitted, unless ωith a mechanical device to change the colour of the external lens, as used in light guns for artistical purposes. 20 The present invention describes a method to change the colour of, the light, by placing a light filter or any oth_ er translucid material, in the desired colour, in such a way that the light beam generated by the filament crosses it be¬ fore leaving the lamp. Each filament has an individual coπ- 25 trol to be energized and has a colour of filter associated to it. Obviously, lamps with only one filament but using an internal filter, as described here, without the need to use a colour bulb is a possible embodiment of this, invention.

The invention is diagra atically illustrated , in 30 the appended drauiings, that shows by way of example, two pos_ sible embodiments of the invention.

Figure 1 shows an embodiment appropriated for lamps f that presents an internal reflector for one of the filaments, as those used for automotive headlight lamps. - ^*■ 35 Figure 2 shows another possible embodiment of the invention, with number of filaments taken at random.

Figure 3 shows in detail the filament embraced by the filter, with two examples of possible embodiments.

In accordance with one embodiment of the present invention (figure l) applied to a lamp with a reflector (l) internal to the bulb (3) intended to partly block the light of one of the filaments (2) in such a way that it concentrate the beam in a desired direction, the filter or any other mate_ rial with the property of changing the colour of the light (4) intercept the beams that leave the filament, reflected by the internal reflector or not, changing the colour to the desired one. Other filaments may be provided or not with fil_ ters (5), in accordance with the desired application.

The control of the colour of the light to be emit-s ted by the lamp is done by the energization of the filament associated to the filter of this colour. The way the filter is fixed inside the bulb (6) is not relevant, provided that it not blocks out significant portion of the light produced by the filament.

In accordance with other possible embodiment of this invention (figure 2) the filaments (l) are embraced by small bulbs (2), fixed by any internal element (4) located interπaly to the external bulb (3). These small internal bulbs (2) intercepts the light emitted by the filaments giving them the desired colour.

The colour of the light resulted from this lamp is defined by the control of which filament is energized in each instant, including the combination of the effects of two or more filaments and filters.

The material that embraces the filament, giving colour to the light, must be installed in such a way that all the beams leaving the filament associated with that fil- ter must cross it in order to haσe its colour changed. Two possible implementations giving this effect are shown (fig¬ ure 3) nevertheless others may be used without changing the object of the present invention.

The filter embracing the filament (l) may almost close in the extremities (2) in order to avoid the light from passing without having its colour changed or may have opaque elements (3) in the extremities, in order to avoid the light beam to pass unless through the filter. The light

of the filament (4) in these situations will present the col_ our of the filter associated to it.