FR3046579A1 - OPTICAL BLOCK COMPRISING A SIGNALING LIGHT WITH A FLAT LIGHT GUIDE OF ITS EXTERIOR ICE - Google Patents

Abstract

The present invention relates to an optical unit for a motor vehicle comprising a housing whose peripheral edge supports an outer covering ice (12); said housing including a signaling light (16) having at least one light diode (17) and a flat light guide (20) having an input surface (23) of light rays generated by said source and front exit face (25) of said light rays; said optical block being characterized in that a portion (27) of said light guide (20) protrudes through and in front of said outer cover ice (12).

Description

Title of the invention

Optical block comprising a traffic light with a flat light guide projecting from its outer ice

Field of the invention

The present invention relates generally to the field of lighting and signaling systems for motor vehicles.

It relates in particular to an optical signaling unit for such a motor vehicle.

Background of the invention

Such an optical block conventionally comprises a housing whose peripheral edge supports an outer covering ice and enclosing at least one lamp intended to provide a signaling function such as, for example, a position light, a blinker indicating a change of direction or else a daytime running light (DRL), which is automatically lit when the vehicle is moving forward to increase visibility in daylight conditions.

These signaling lights must ensure a light diffusion according to a regulatory photometric grid which imposes a specific minimum luminous intensity range for each of the points of this grid.

In particular, the latter must respect geometric angles of visibility which delimit the area of the minimum solid angle in which the apparent surface of the light must be visible (ECE Regulation 48 2.13). This zone is determined by the segments of a sphere whose center coincides with the reference center of the fire and whose equator is parallel to the ground. These segments are defined from the optical axis of the fire: the horizontal angles correspond to the longitude and the vertical angles to the latitude. Within these angles of geometric visibility, there must be no obstacle to the propagation of light from any point on the apparent surface of the fire observed from infinity. This regulation is particularly demanding concerning the horizontal angles which must be at least 45 ° internal side and 80 ° external side.

For issues of lower consumption of electrical energy, longer life and freedom of style, it is now common to use, as an alternative to conventional incandescent bulbs, laser or electroluminescent light diodes (The latter being more commonly referred to by the acronym "LEDS").

It is also known, particularly from the French patent application FR 3,014,787, to associate these diodes with a flat-type light guide (more commonly referred to as "fiat guide") housed inside the housing and adapted to transfer the light rays that feed its input surface to an exit front face located opposite said cover glass.

In order to satisfy the regulatory photometric grid, such a light guide must thus be provided on its front face with optical elements capable of spreading the light horizontally and vertically.

Nevertheless, compliance with the minimum angles of geometric visibility for this type of traffic light is particularly delicate, especially in the horizontal plane.

Object and summary of the invention

The present invention therefore aims to facilitate compliance with the regulatory photometric grid for such a traffic light with a flat-type light guide.

It proposes for this purpose an optical unit for a motor vehicle comprising a housing whose peripheral edge supports an outer covering ice; said housing enclosing a signaling light having at least one light diode and a flat-type light guide having an input surface of the light rays generated by said source and an output front face of said light rays; said optical block being characterized in that a portion of said light guide protrudes through and in front of said outer cover ice.

This projecting portion of the light guide thus allows the signal light of the optical block according to the invention to more easily comply with horizontal geometric visibility angles imposed by the regulations, in particular that of 45 ° internal side, since the outgoing light rays do not are further impeded by the peripheral edge of the optical compartment case or by the vehicle grille.

According to preferred features of the invention, taken alone or in combination: - said light guide and said outer cover ice are integrally made of material; said light guide and said outer covering ice are obtained by a bi-injection molding process; said light guide and said outer covering ice are respectively formed in a first and a second material chosen from polycarbonate (PC) and polymethyl methacrylate (PMMA). ; said light guide and said outer covering ice are formed of the same material; said outer cover glass is partially tinted in the periphery of said light guide so as to form an opaque surround around the latter; said light guide projects at the front of said cover glass by a predetermined distance so that in the mounted configuration of said optical block, a portion of said exit face is visible from the horizontal and vertical geometric vertical visibility angles ; said predetermined distance is between 10 and 40 mm; said front face of said light guide is sandblasted or grained in order to ensure diffusion of the light rays passing therethrough over an extended angular range; and / or - at least a portion of said exit face of said light guide extends along a plane inclined downwardly with respect to the vertical, so as to respect the regulatory thresholds of light intensity from a point of view vertical.

BRIEF DESCRIPTION OF THE DRAWINGS The description of the invention will now be continued by the detailed description of an exemplary embodiment, given below by way of illustration but without limitation, with reference to the appended drawings, in which: FIG. a front view of a portion of a front optical unit according to the invention; - Figure 2 shows a sectional view of the optical block of Figure 1, taken along a vertical longitudinal plane; and - Figure 3 is an enlargement of detail III of Figure 2.

Detailed description of a preferred embodiment

An orthogonal reference mark XYZ is defined in the figures comprising three mutually perpendicular axes, namely: an axis X defining a longitudinal direction parallel to the longitudinal axis of the vehicle; a Y axis defining a horizontal transverse direction; , which with the X axis defines a horizontal XY plane, and - an Z axis, defining a vertical direction, perpendicular to the horizontal XY plane.

In the following description and by convention, the terms "lower", "upper", "longitudinal" and "transverse" will be defined with respect to the mounting position of this optical signal unit 10 on such a vehicle.

Figures 1 and 2 here represent the major part of a front optical unit 10 to be mounted on the body structure of a motor vehicle.

This optical unit 10 comprises a housing 11 preferably integrally molded from a thermoplastic polymer such as acrylonitrile butadiene styrene (ABS), and whose peripheral edge supports an outer cover 12.

In the following description, the terms "back" and "front" will be used to designate portions of the same element respectively oriented towards the bottom of the housing 11 or in the opposite direction.

This housing 11 encloses here a position / road light 13 (visible only partially in FIG. 1), a dipped beam 14, a direction indicator flashing light, 15 as well as a diurnal light 16 commonly referred to as acronym DRL (Daytime Running Light).

This diurnal traffic light 16 comprises a light guide 20 of the flat type (or "fiat guide") extending substantially longitudinally and in the form of a sheet having an L-shaped cross-section, the latter being delimited in FIG. direction of the thickness by two main faces of guides 21, 22 curves and substantially parallel to each other, (Figure 1).

As illustrated by this figure 1, the main branch 20A of this light guide 20 extends substantially horizontally in the lower part of the housing 11 while its branch of smaller length 20B extends substantially vertically along the outer edge of this housing 11.

The daytime running light 16 also comprises a plurality of light sources 17 capable of generating a white light, and in this case constituted by light-emitting diodes of the electroluminescent (LEDS) or laser type.

These light-emitting diodes 17 are implanted on a rigid or flexible printed circuit board (PCB) 18, which is housed inside the housing 11 and extends parallel to and above the guide of FIG. light 20.

This PCB 18 further comprises means not shown to ensure its attachment to the housing 11, the latter being for example in the form of fixing lugs cooperating by screwing or snapping with complementary means provided on the housing 11.

The light rays emitted by each light diode 17 penetrate into the light guide 20 through a respective input surface 23 located at the top of a corresponding dome 24 protruding from its upper main guiding face 21, this light guide being adapted to transfer these light rays towards its front exit face 25.

It will be noted with reference to FIG. 3 that each of these light-emitting diodes 17 has an emission axis substantially perpendicular to its respective input surface 23.

It will also be noted that the light guide 20 comprises, at the periphery of each dome 24, a plurality of studs 26 angularly distributed and on the free ends on which the PCB 18 rests around a corresponding light diode 17, so as to maintain the gap predefined between each diode 17 and its respective input surface 23.

According to the invention, a portion 27 of the light guide 20 protrudes through and in front of the outer cover glass 12 by a predetermined distance advantageously between 10 and 40 mm, so that in the mounted configuration of the block 10, a portion of its outlet face 25 is visible from the horizontal and vertical geometric visibility angles regulatory.

This exit face 25 is advantageously sandblasted or grained in order to ensure diffusion of the light rays passing through the light guide 20 over an extended angular range, so that the minimum threshold of regulatory light intensity reaches the points of the light. photometric grid located at the extreme horizontal angles of geometric visibility (and in particular up to the one at the geometric visibility angle of 45 ° internal side).

At the level of the horizontal main branch 20A of the light guide 20, this outlet face 25 extends in a plane inclined downwardly with respect to the vertical, so as to comply with the minimum light intensity thresholds of a vertical point of view.

The light guide 20 and the outer cover glass 12 are additionally made of one-piece material, advantageously by bi-injection molding.

This type of molding is preferably obtained by the transfer technique: a first injection of a first thermoplastic material is first made in a first mold to form the light guide 20, the latter then being demolded and then transferred into a second mold in which a second injection of a second thermoplastic material is performed so as to obtain the final piece.

The first and second materials respectively constituting the light guide 20 and the outer covering ice are advantageously identical and chosen from polycarbonate (PC) and polymethyl methacrylate (PMMA).

The fact that the light guide 20 is formed integrally with the outer cover glass 12 not only avoids any problem of sealing between these two elements but also to do without fastening means by snapping or screwing traditionally used to ensure the fixing of such a light guide to the housing which results in a significant economic gain and a significant reduction in the mounting time of such an optical unit.

Preferably, the outer cover glass 12 is partially tinted in the mass at the periphery of the light guide 20, so as to form an opaque surround and preferably black around this guide 20.

According to alternative embodiments not shown, the front face of exit of the light guide has a stepped shape with flat steps and risers each comprising a plurality of convex facets joined laterally.

According to other embodiments not shown, the rear face of the light guide has an inclined parabolic profile, the latter forming a reflective surface through which the light entering through the input surfaces is returned to the front face of exit under the shape of a beam with substantially parallel radii oriented in a substantially longitudinal direction.

According to still other embodiments not shown, the optical unit contains only a single signaling light. In general, it is recalled that the present invention is not limited to the embodiments described and shown, but encompasses any embodiment within the scope of those skilled in the art.

In particular, it will be noted that the invention can also be implemented in a rear optical unit and that it is not limited to a particular type of signaling light (this therefore also relates to the direction indicator flashing lights). , position lights or even reversing lights).

Claims (10)

An optical unit for a motor vehicle comprising a housing (11) whose peripheral edge supports an outer covering ice (12); said housing (11) enclosing a signaling light (16) having at least one light diode (17) and a flat-type light guide (20) having an input surface (23) of the light rays generated by said light source and an output front face (25) of said light rays; said optical block being characterized in that a portion of said light guide (20) protrudes through and in front of said outer cover ice (12). An optical unit according to claim 1, characterized in that said light guide (20) and said outer cover skin (12) are integrally made of material. An optical unit according to claim 2, characterized in that said light guide (20) and said outer cover skin (12) are obtained by a bi-injection molding process. 4. Optical block according to one of claims 1 to 3, characterized in that said light guide (20) and said outer cover ice (12) are respectively formed in a first and second materials selected from polycarbonate (PC ) and polymethyl methacrylate (PMMA). 5. Optical block according to one of claims 1 to 4, characterized in that said light guide (20) and said outer cover ice (12) are formed in the same material. An optical unit according to one of claims 1 to 5, characterized in that said outer cover glass (12) is partially tinted in the periphery of said light guide (20) so as to form an opaque surround around this last. Optical block according to one of claims 1 to 6, characterized in that said light guide (20) protrudes in front of said cover glass (12) by a predetermined distance so that in the assembled configuration said optical block (10), a portion of said output face (25) is visible from the horizontal and vertical geometric visibility angles. An optical unit according to claim 7, characterized in that said predetermined distance is between 10 and 40 mm. 9. An optical unit according to one of claims 1 to 8, characterized in that said front face (25) of said light guide (20) is sanded or grained to ensure a distribution of light rays passing through an angular range extended. 10. Optical block according to one of claims 1 to 9, characterized in that at least a portion of said outlet face (25) of said light guide (20) extends in a plane inclined downwards relative to vertically, so as to respect the regulatory thresholds of light intensity from a vertical point of view.