Lamp device for a motor vehicle illuminating gantry points

DETAILED DESCRIPTION To do this, the invention proposes a lamp device for a motor vehicle, comprising at least one reflector, a light source producing a set of light signals possibly being reflected by the reflector, an output lens, comprising an input surface, an output surface and a focus, for producing a light beam, and a mask disposed between the reflector and the output lens for implementing a cutoff line in the light beam produced, characterised in that the output lens comprises a set of arrangements implemented in at least one circumferential part of the output surface of the lens, this set being capable of deviating in a given direction some of the light signals encountering this arrangement.
According to a preferred embodiment, the deviation directions are directions situated above the cutoff line.
And preferably, these arrangements are capable of deviating some of the light signals encountering this arrangement in a direction corresponding to a gantry point.
According to a first implementation variant, this circumferential part is disposed on the lower part of the lens.
In this case, preferably, it is substantially symmetrical with respect to a vertical plane of symmetry of the lens.
Advantageously, this circumferential part extends over approximately 45° on each side of said plane of symmetry.
This first variant has the advantage of modifying the external appearance of the lens only minimally and of therefore being very unobtrusive visually.
According to a second implementation variant, this circumferential part extends over the entire perimeter of the lens.
This second preferred implementation variant has the advantage of entailing no constraint of angular positioning of the lens.
However, it turns out that implementation of the polarisation arrangement, of the type of a notch on the lens fitting over a rib on its support, is a relatively tricky operation in view of the fragility of such lenses.
More precisely, preferably, this circumferential part consists of a tapered surface with a rectilinear generator inclined by an angle determined in order to obtain a deviation upwards of the optical signals coming from the focus and passing through it at the low point of the lens