In today's rear lamps, the importance of styling aspects influences not only the shape and size of the lamp, but also the colours used for the outer lenses are subject of design. Often only two colours (red and white) are desired, which makes it necessary to hide the unwanted colours by optical tricks. In the past, a lot of efforts have been made to develop concepts for hiding the colour. A very popular concept is to eliminate the clear section for the backup lamp removing it from the rear lamp and installing it separately, e.g. in the bumper. However, this is not feasible for the turn signal, which has to be installed in the rear lamp. If the amber colour has to be hidden, other approaches have to be taken into account. In general, there are two options for the turn signal indicator: either to hide the amber colour behind a white (= colourless) lens, or behind a red lens. Each request requires a different solution. For a colourless lens, a bulb solution must use an amber filter in any case. Often, the effect can be reduced by introducing some diminution optics (e.g. convex cylinder lenses) in the clear outer lens. A perfect clear design is possible if LEDs are applied. Since the LED itself is completely colourless, no amber colour at all disturbs the unlit appearance. The second, more demanding approach is to hide the turn signal indicator behind a red outer lens. The solutions described in the paper refer to turn signals with red outer lens and without visible amber lenses either with bulbs or with LEDs. The solutions with bulbs have restrictions with respect to design freedom, due to the high losses by thermal load, and due to the requirements imposed by the AMECA directions. On the other hand, LED solutions allow for more freedom in the selection of the red outer lens colour, since the LED light is less strongly affected by the filtering of the outer lens.
The effect of red outer lenses on colour shift for turn signal applications: a comparison between LED and bulb turn signals
Die Auswirkung roter Außenlinsen auf die Farbänderung bei Fahrtrichtungsanzeigeranwendungen: Vergleich zwischen LED- und Glühlampenanzeiger
2005
8 Seiten, 6 Bilder
Aufsatz (Konferenz)
Englisch
TURN-SIGNAL-LIGHT CONTROL DEVICE, TURN-SIGNAL DEVICE, AND CONTROL METHOD FOR TURN-SIGNAL DEVICE
Europäisches Patentamt | 2015
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