FR3090823A1 - Lighting device for vehicle ceiling light - Google Patents

Abstract

The invention relates to a lighting light source (33), in particular for a vehicle ceiling lamp (100), comprising: a cylindrical body (34) made of transparent material, with an axis of revolution (A), a diopter of inlet (35) at an axial end of the cylindrical body, an outlet diopter (37) at the end of the axially opposite cylindrical body of the inlet diopter (35), characterized in that the inlet diopter (35) is produced in the form of a lens for collimating a light beam coming from a light source arranged, in the assembled state, at a focal point (F) of the lens, and in that the output diopter ( 37) is produced in the form of a plurality of planar surfaces (S1, S2, S3, S4) of normal (N1,…, N4) inclined with different directions relative to the axis of revolution (A) of the cylindrical body . Figure to be published with the abstract: [Fig. 2a]

Description

Description

Title of the invention: Lighting device for vehicle ceiling lamp

The present invention relates to a lighting device, in particular for a vehicle interior ceiling light.

Vehicle interiors are generally provided with an overhead lighting device, also known as a reading light, providing the driver or a passenger with auxiliary lighting allowing for example to consult a map or read a text. .

These devices generally include one or more light sources, implemented in the vehicle ceiling light, and the driver or passenger actuates a switch to turn the light source on or off. The light beam from the source is shaped (concentrated and uniform) and then directed towards an expected position of the driver or passenger, generally the seats they are supposed to occupy.

In the context of aesthetic choices for the purification of the passenger compartment of vehicles, it is known to arrange the light sources behind a window, covered with an opaque layer for the majority of its surface, which is equipped with a tactile surface, the actuation of which by contact with the finger or the hand of a user switches the lighting on or off, the beam of which passes through the glass via an opening in the opaque layer.

To delimit the portion of the touch surface whose actuation triggers the lighting, we can use a backlit outline, surrounding the opening through which the lighting beam passes. The backlight has the advantage of making visible the portion of the tactile surface forming an actuator in the dark or half-light of a passenger compartment at night.

To obtain this backlit outline, we then have in the ceiling a delimiting light source, with an associated light guide.

The presence of two sets of diodes forming the lighting and delimiting light sources, with associated guides or lenses, as well as the potential presence of other elements on a printed circuit carrying the diodes such as loudspeakers. ceiling light (as part of a multimedia device) imply a gap between said printed circuit and the apparent surface, with which the user interacts.

This difference, with the presence of two nested light sources, delimitation and lighting, makes the routing of complex light beams, especially taking into account the fact that the light beams must be tilted and oriented towards the driver and passenger from a central ceiling light.

In order to at least partially solve the problem mentioned above, the invention relates to a lighting light guide, in particular for a vehicle ceiling light, comprising:

A cylindrical body made of transparent material, with an axis of revolution, an input diopter at an axial end of the cylindrical body,

An output diopter at the axially opposite end of the input diopter characterized in that the input diopter is produced in the form of a lens for collimating a light beam coming from a arranged light source, in the assembled state, at a focal point of the lens, and in that the exit diopter Is produced in the form of a plurality of planar surfaces of norms inclined with different directions relative to the axis of the cylinder .

The light guide thus obtained is used to distribute the light in a space such as a passenger compartment in a relatively uniform manner. The length of the light guide is variable, which allows greater freedom of design of the ceiling light.

The light guide may also have one or more of the following characteristics, taken alone or in combination.

The output diopter may include:

a first surface covering one half of the exit diopter with a normal inclined with respect to the axis of the cylinder at an angle of between 20 and 60 °, a third surface, forming a central radial band in axial withdrawal from the first surface on half of the diopter not covered by the first surface, a second and a fourth surface, arranged on either side of the third surface, inclined with respect to said surface at an angle between 20 and 60 °, the second, third and fourth surfaces forming a concave relief on one half of the output diopter.

The input diopter can be produced in the form of an Eresnel lens.

The invention also relates to the light guide device for a vehicle ceiling lamp, characterized in that it comprises:

At least one lighting light guide as mentioned,

A lighting light source disposed at a focal point of the lens formed by the input diopter of the lighting light guide,

A delimiting light guide, comprising a tubular body, with a tubular base having an annular exit diopter, surrounding the exit diopter of the lighting light guide, and an upper portion separated into at least two parts by at least two triangular V-shaped cuts, the point of which is oriented towards the tubular base, with at least two input diopters, in the form of arcs of a circle and planes.

The triangular cuts can have an extension along the axis of revolution of the lighting light guide of between 30 and 70% of the total extension of the delimiting light guide along said axis.

The walls of the delimiting light guide may have diffusing recesses, arranged axially opposite the entry dioptres of the delimiting light guide, said diffusing recesses being in the form of a triangular recess or cut with a directed tip. towards the input diopter axially opposite, and a base substantially parallel to the plane of the opening (s).

Finally, the invention also relates to the overhead light of a motor vehicle, characterized in that it comprises:

At least one light guide device as mentioned,

A facade comprising a transparent layer of material of high transparency to the radiation of light sources, and an opaque layer over most of its surface, except for the portions corresponding to the openings.

The transparent layer can be tinted in the mass with dark or black dyes, so as to have a transparency of 10 to 50%.

The facade may include a tactile surface whose active surface is limited to the surface delimited by the openings, configured to control the switching on or off of the lighting and delimiting light sources.

Other features and advantages of the invention will appear more clearly on reading the following description, given by way of illustrative and non-limiting example, and the appended drawings among which: [fig.l] schematically shows a passenger compartment of the vehicle, with a ceiling lamp having two lighting devices, [fig.2a] shows a lighting device outside the ceiling lamp according to a first embodiment,

[fig.2b] shows the device of figure 2a in bottom view,

[fig.2c] is a partial section view of the light guide of figure 2b, [fig.3] shows a delimiting light generation module for a lighting device, [fig.4] is a view from below a light generation device combining lighting light and boundary light,

[fig-5] is a side view of the ceiling light,

[fig-6] is a schematic representation of a ceiling lamp comprising two light generation devices.

The embodiments described with reference to the figures are examples. Although the description refers to one or more embodiments, this does not necessarily mean that each reference relates to the same embodiment, or that the characteristics apply only to a single embodiment. Simple features of different embodiments can also be combined to provide other embodiments.

The terms such as first and second used below are given for simple referencing without indicating any preference or particular order of assembly.

A number of position qualifiers such as above or below, below, to the left, etc. are also used in connection with the figures. These qualifiers only serve to assist in understanding the figures described and the embodiment they represent. In particular, the same embodiment of the control module can equally be mounted on surfaces oriented in different ways.

Figure 1 schematically shows a passenger compartment of a motor vehicle, comprising a ceiling light 100 in which an lighting device is arranged. In particular, two light outputs 101, 103 by which a light beam is sent respectively towards a user U, driver or passenger of the vehicle.

A light generation device 1 of the ceiling light 100 is shown in Figure 2a. In particular, a single light generation device 1 comprising a lighting light generation module 3.

Said lighting light generation module 3 comprises in particular a lighting light source 31, for example a high power diode, in particular a white diode typically of more than 100 lumens, and a light guide lighting 33. The lighting light generating device 3 is in particular aligned along the normal to the opening 101, facing said opening 101.

The lighting light guide 33 has a tubular body 34, of axis of revolution A orthogonal to the plane of the opening 101. It is made of transparent material, typically polymethyl methacrylate (PMMA).

The lighting light guide 33 includes an input diopter 35, facing, in the assembled state, the lighting light source 31.

In particular, the input diopter 35 is produced in the form of a lens, in particular an aspherical lens, the focus F of which corresponds to the expected position of the lighting light source 31. The input diopter 35 allows then to collimate the light beam emitted by the lighting light source 31 along an axis orthogonal to the opening 101.

The lighting light guide 31 includes an output diopter 37, facing, in the assembled state, the opening 101, a contour of which is shown in dotted lines.

In particular, the output diopter 37 is produced in the form of a plurality of plane surfaces SI to S4 (see FIGS. 2b and 2c), the number of said surfaces SI to S4 being greater than or equal to 3. Said plane surfaces SI to S4 have normals NI to N4 which are oriented at specific angles, between themselves and with respect to the axis of revolution of the lighting light guide 33.

Figure 2b shows the output diopter 37 of the lighting light guide 33 in front view.

In this view, the outer contour of said output diopter 37 is circular. Half of this circle is occupied by the first planar surface S1, the planar surfaces S2 to S4 covering the other half of the circle. The surface SI is inclined with its normal pointing radially outward (see FIG. 2a), with an angle relative to the axis of revolution from 20 to 60 °.

The light exiting through said first planar surface S1 is for example emitted towards the driver or passenger seat. Its large surface (half of the output diopter 37) makes the generated beam relatively bright.

The surface S3 is in the form of a radial strip, arranged at the center of the semicircle which the surfaces S2 to S4 occupy. The surfaces S2 and S4 then occupy the semicircle portions on either side of the surface S3.

Figure 2c is a section along the axis B-B (see Figure 2b) parallel to the line of demarcation between the surfaces SI on the one hand and S2 to S4 on the other hand. This line is parallel or merged with a diameter of the circle of the output diopter 37, and perpendicular to the strip occupied by the surface S3.

We can see in Figure 2c that the third planar surface S3 is recessed relative to the lower edge of the lighting light guide 33, and that the surfaces S2 and S4 are arranged on either side of the surface plane S3. The surfaces S2 and S4 are inclined with respect to said surface at an angle between 20 and 60 °. The plane surfaces S2, S3 and S4 thus form a concave relief in the plane of Figure 2c.

The light exiting through said surfaces S2 to S4 is emitted in the direction of the steering column (central strip between the passenger and driver seats, on the right in FIG. 1). The concave relief shape of said surfaces S2 to S4 makes it possible to generate a divergent light beam along the direction of the axis B-B (plane of FIG. 3).

Other embodiments can be obtained by modifying the shape, the position or the inclination of the plane surfaces SI to S4. The flat surfaces SI to S4, due to their norms inclined in different directions, thus distribute the light from the lighting light source 51 in a space corresponding to one half of the passenger compartment of the vehicle.

In other embodiments, not shown, the input diopter is produced in the form of a Lresnel lens, possibly allowing greater compactness in the direction perpendicular to the opening 101.

FIG. 3 is a schematic representation of a delimiting light generation module 5, which can be incorporated into the light generation device 1 with the lighting light generation module 3.

Said delimiting light generation module 5 comprises at least two delimiting light sources 51, and a delimiting light guide 53. The delimiting light guide 53 is roughly tubular, with a lower portion forming a base tubular 55, and an upper portion 57 separated in two by two triangular cutouts 59 in V, the point of which is oriented towards the tubular base 55. The delimiting light guide 53 is for example also made of PMMA or other high plastic material transparency.

At the lower end of the tubular base 55 is an annular outlet diopter 61, the outline of which corresponds to that of the opening 101. Opposite the outlet diopter 61, at the parts of the upper portion 57 between the triangular cutouts 59, there are two input diopters 63, in the form of arcs of a circle and planes.

Axially facing the input diopters 63 are arranged the delimiting light sources 51. According to other embodiments, the lighting light generation module 5 comprises more than two delimiting light sources 51, regularly distributed around the perimeter of the delimiting light guide 53, which then comprises more than two triangular cutouts 59, separating at least three input diopters 63, one for each delimiting light source 53.

Axially under the input diopters 63 are diffuser recesses 65, of triangular shape, with a point directed towards the input diopter 63 above, and a base substantially parallel to the plane of the opening 101. These diffuser recesses 65 are shown in more detail in FIG. 5.

The diffuser recesses 65 are either radially through openings or recesses which do not radially pass through the walls of the delimiting light guide 53.

In the assembled state, the lighting light guide 33 is inserted into the housing in the center of the delimiting light guide 53. The assembly obtained is shown in bottom view in FIG. 4.

We see in Figure 4 that the output diopter 61 of the delimiting light guide 53, of annular shape, surrounds the output diopter 37 of the lighting light guide 33, of circular shape.

FIG. 5 is a side view of the lighting light guides 33 and of delimitation 53 placed on a front plate 4.

The lighting light guides 33 and delimitation 53 are shown nested. The side view is centered on one of the diffusing recesses 65. A light ray coming from a delimiting light source entering the diffusing recess 65 is shown in dashes.

Said ray is emitted by the delimiting light source 51 with a slight inclination relative to the axis of revolution of the lighting light guide 33. When said ray strikes one of the sides of the diffuser recess 65, it is diffracted by the PMMA / air interface (or more generally the material of the guide / air) which is located on said side. The inclination of the ray of light is thus increased.

The light ray then meets the base of the diffuser recess 65, and is again diffracted by the air / PMMA interface which is located at said base. The tilt of the light beam is increased again.

At the output diopter 61, the light ray is again diffracted, as well as at the facade 4 and its different layers. The light beam at the output of the delimiting light source 51 is thus distributed over the entire annular output diopter 61. The apparent surface ring thus obtained is then more uniform in appearance.

To optimize the distribution of the brightness, the triangular cutouts 59 have a height along the axis of the lighting light guide 33 between 30 and 70% of the total height of the delimiting light guide 53 le along said axis.

The opening 101 shown in Figure 5 is carried by the front 4, opaque on the majority of its apparent front surface for the occupants of the vehicle. The facade 4 here comprises a transparent layer 41 made of material of high transparency to the radiation from light sources 31, 51 and an opaque layer 43 colored over the major part of its surface, except for the portions corresponding to the opening 101.

In the embodiment of Figure 5 the opaque layer 43 is relatively thick (a few millimeters to 1cm for example). In other embodiments, this opaque layer 43 is a single layer of paint.

The facade 4 is in particular has on its front surface a transparent touch surface 45, which, when contact with a part of the body of a user U (finger, hand) is detected, turns on or off the source of lighting light 31. Contact with the touch surface 45 can also be used to respectively turn off or on the boundary light source 53 when the lighting light source 31 is on or off. In other embodiments, the stacking order of the transparent 41, opaque 43 and tactile 45 layers is modified.

The opening 101 has in particular a transparency of between 10 and 90% in the visible spectral range. The transparent plate composing it can however be tinted in the mass with dark or black dyes, so as to reduce the transparency to 10 to 50%. These transparency values, with a dark tint, make it possible to make the opening 101 imperceptible in the absence of lighting therethrough.

The touch surface 45, or at least a portion of its active surface is advantageously limited to the surface delimited by the openings 101, 103 and possibly their immediate vicinity.

Figure 6 is a schematic representation of a ceiling light 100 having two light generation devices 1a and 1b. Each of the light generation devices 1a, 1b comprises a lighting light generation module 3 and a delimiting light generation module 5, as well as two openings 101, 103 allocated, for example, respectively to the driver and to the passenger front of the vehicle.

Each of the light generating devices 1a, 1b is arranged in a position symmetrical with respect to the other, each at one of the two openings 101, 103.

The light beam from the lighting light generation module 3 of the first device 1a is directed mainly towards an expected position of a first user Ua, for example the driver of the vehicle. The expected position of said first user Ua is then the driver's seat of the vehicle.

The light beam from the lighting light generation module 3 of the second device 1b is directed to an expected position of a second user Ub, for example the front passenger of the vehicle. The expected position of said first user Ub is then the front passenger seat of the vehicle.

The ceiling light 100 thus obtained can easily be arranged at the rear view mirror of a conventional vehicle. The light beams are then directed towards the occupants (front passenger Ub and driver Ua) so as to allow them to read a map, find an object or the like. The light from the boundary light generation module 5 makes it possible to make visible the areas on which a pressure will trigger the emission of a beam of lighting light, in particular in a dark environment, for example at night or in a tunnel or garage.

Claims (1)

Claims [Claim 1] Lighting light guide (33), in particular for a vehicle ceiling lamp (100), comprising: a cylindrical body (34) of transparent material, with an axis of revolution (A), an input diopter (35) at an axial end of the cylindrical body, an output diopter (37) at the end of the axially opposite cylindrical body of the input diopter (35), characterized in that the input diopter (35) is produced in the form of a lens for collimating a light beam coming from a light source arranged, in the assembled state, at a focal point (F) of the lens, and in that the output diopter (37) is produced in the form of a plurality of planar surfaces (SI, S2, S3, S4) of normal (NI, ..., N4) inclined with different directions relative to the axis of revolution (A) of the cylindrical body. [Claim 2] Light guide according to claim 1, characterized in that the output diopter comprises: a first surface (SI) covering one half of the exit diopter with a normal (NI) inclined relative to the axis of the cylinder at an angle between 20 and 60 °, a third surface (S3), forming a central radial band in axial withdrawal with respect to the first surface (SI) on the half of the diopter not covered by the first surface (SI), a second (S2) and a fourth surface (S4), arranged on either side of the third surface (S3), inclined relative to said surface (S3) at an angle between 20 and 60 °, the second (S2), third (S3) and fourth (S4) surfaces forming a concave relief on one half of the output diopter (37). [Claim 3] Light guide according to claim 1 or 2, characterized in that the input diopter (35) is produced in the form of a Fresnel lens. [Claim 4] Light guiding device for vehicle ceiling lamp, characterized in that it comprises: at least one lighting light guide (33) according to claim 1, 2 or 3, an illumination light source (31) disposed at a focal point (F) of the lens formed by the input diopter (35) of the illumination light guide (33), a delimiting light guide (53), comprising a tubular body, with a tubular base (55) having an annular exit diopter (61), surrounding the exit diopter (37) of the lighting light guide (33) , and an upper portion (57) separated into at least two parts by at least two triangular cutouts (59) in V, the point of which is oriented towards the tubular base (55), with at least two input diopters (63 ), in the form of arcs and circles. [Claim 5] Light guide device according to the preceding claim, characterized in that the triangular cutouts (59) have an extension along the axis of revolution (A) of the lighting light guide (33) of between 30 and 70% total extension of the delimiting light guide (53) along said axis (A). [Claim 6] Light guiding device according to the preceding claim, characterized in that the walls of the delimiting light guide have diffusing recesses (65), arranged axially opposite the input diopters (63) of the delimiting light guide (53 ), said diffusing recesses (65) being in the form of a recess or triangular cutout with a point directed towards the input diopter (63) axially opposite, and a base substantially parallel to the plane of the opening (s) (101, 103). [Claim 7] Motor vehicle ceiling light, characterized in that it comprises: at least one light guiding device according to one of claims 4 to 6, a facade (4) comprising a transparent layer (41) made of material of high transparency to radiation light sources (31, 51), and an opaque layer (43) over most of its surface, except for the portions corresponding to the openings (101, 103). [Claim 8] Ceiling lamp according to the preceding claim, characterized in that the transparent layer (41) is tinted in the mass with dark or black dyes, so as to have a transparency of 10 to 50%. [Claim 9] Ceiling lamp according to claim 7 or 8, characterized in that the front comprises a tactile surface (45) whose active surface is limited to the surface delimited by the openings (101, 103), configured to control the switching on or off sources of lighting light (31) and delimitation (51). 1/7