WO2018091803A1

WO2018091803A1 - Lighting device comprising a screen with regions having different light transmission coefficients

Info

Publication number: WO2018091803A1
Application number: PCT/FR2017/053069
Authority: WO
Inventors: Michael Bore; Serge ROSSO
Original assignee: Psa Automoliles Sa
Priority date: 2016-11-21
Filing date: 2017-11-10
Publication date: 2018-05-24
Also published as: FR3059082A1; CN109983276A; EP3542101A1; FR3059082B1; EP3542101B1

Abstract

The invention relates to a lighting device (DE) comprising a light source (SL) for delivering, to a predefined site (EP), photons having at least one photometric function, and a screen (EC) placed in front of the predefined site (EP) and comprising alternating first (Z1) and second (Z2) zones respectively having a first light transmission coefficient and a second light transmission coefficient which is strictly lower than the first, such that the intensity of the light resulting from the photons passing through each first zone (Z1) is strictly higher than the intensity of the light resulting from the photons passing through each second zone (Z2).

Description

ZONED SCREEN LIGHTING DEVICE HAVING DIFFERENT LIGHT TRANSMISSION COEFFICIENTS

The invention relates to lighting devices, and more specifically those which comprise a light source delivering photons for providing at least one photometric function.

The term "lighting device" is understood here to mean a light device capable of providing at least one photometric function of lighting or signaling or of a luminous effect, possibly decorative.

In some areas, such as vehicles, possibly of the automotive type, lighting devices are used to produce a light strip consisting of an alternation of first light areas and second dark areas. This is for example the case where the lighting device is intended to provide a position light function (or night light or lantern) and / or a daylight function (or DRL (for "Daytime running Light (gold Lamp) "- illuminated warning light automatically when the vehicle is in operation during the day)).

Currently, this type of device comprises a light source (generally at least one light-emitting diode associated with a light guide), a mask placed in front of the light source and comprising through holes defining the first zones and gaps between through holes defining the second zones, and a protective glass placed in front of the mask with holes. The mask is made of an opaque plastic material (eg black), and therefore only the photons that pass through the through holes generate the light in the first areas that are interspersed between second opaque areas preventing the passage of photons.

Such an arrangement has several disadvantages. Indeed, it is relatively compact in the general direction of photon propagation (longitudinal direction in the case of a vehicle) of the made of the presence of a mask and a protective glass. Then, it is often subject to condensation between its mask and its protective glass due to significant temperature differences upstream of the mask and downstream of the protective glass. Moreover, it does not offer a very

5 good light output because a portion of the photons is prevented from going outside due to the presence of the second opaque areas defined by the mask outside the through holes. In addition, the positioning of the protective glass in front of the mask is often difficult because of their respective manufacturing dimensional tolerances and their games.

).

The invention is therefore particularly intended to improve the situation.

It proposes for this purpose a lighting device comprising a clean source of light to deliver in a predefined place photons to ensure at least one photometric function.

This lighting device is characterized in that it also comprises a screen placed in front of the predefined location and comprising an alternation of first and second zones respectively having a first coefficient of light transmission and a second coefficient of light transmission strictly lower. at this first coefficient of

) light transmission, so that the light resulting from the photons passing through each first zone has an intensity strictly greater than the intensity of the light resulting from the photons passing through each second zone.

Thus, it eliminates the mask holes, which allows in particular to reduce the space in the general direction of photon propagation, and to facilitate the positioning of the screen.

The lighting device according to the invention may comprise other characteristics that can be taken separately or in combination, and in particular:

the first zones may have a first color and the second zones may have a second color;

the first color may be a color called transparent white crystal and the second color may be opaque black; the screen may be a part in which the first zones are made of a first plastic material having the first color and the second zones are made of a second plastic material having the second color;

The part may comprise first and second sub-parts made respectively in the first and second plastics. The first sub-part is fixedly secured to at least a part of an outer face of the second sub-part, facing away from the predefined place, and the second sub-part

) comprises through-holes defined in front of portions of the first sub-part which respectively define the first zones;

alternatively, the screen may be a piece of plastic or glass having the first color and having a face provided with elements

5 reported having the second color and defining the second areas;

the light source may comprise at least one light-emitting diode, optionally of organic type;

the light source may comprise a light guide adapted to transfer the photons generated, received on an input face, to a

) front face located just before the predefined place and clean to transfer these photons in the latter.

The invention also proposes a vehicle optical unit, possibly of automobile type, and comprising at least one lighting device of the type of that presented above.

The invention also proposes a vehicle, possibly of automobile type, and comprising at least one lighting device of the type of the one presented above or at least one optical block of the type of that presented above.

Other characteristics and advantages of the invention will become apparent on examination of the following detailed description, and the appended drawings, in which:

- Figure 1 illustrates schematically in a sectional view in a plane XY, an example of an optical block comprising an exemplary embodiment of a lighting device according to the invention, and

FIG. 2 schematically illustrates, in a front view, an example of a light strip obtained by means of the lighting device of FIG. 1.

The object of the invention is in particular to propose a lighting device DE intended to provide at least one photometric function.

In what follows, it is considered, by way of non-limiting example, that the lighting device DE is intended to equip an optical block BO of a vehicle of the automotive type, such as a car. But the invention

) is not limited to this application. Indeed, a lighting device DE may be an equipment in itself (possibly including its own housing), or may be part of another equipment that a vehicle optical unit. Thus, a lighting device DE can be part of any vehicle (terrestrial, maritime (or fluvial), or aerial), of any installation, including

Including industrial type, any device (or system), and any building.

Furthermore, it is considered in what follows, by way of non-limiting example, that the optical block BO (comprising at least one lighting device DE) is a front light providing at least one function

) a signaling light, such as a position light function (or pilot light or lantern) and / or a daylight running function (or DRL (for "Daytime running Light (Gold Lamp)" - illuminated automatically when the vehicle is put into operation during the day)). But the invention is not limited to this application. In

Indeed, the lighting device DE, according to the invention, is a luminous device capable of providing at least one photometric function of lighting or signaling or of a luminous effect, possibly decorative.

In Figures 1 and 2, the direction X is a so-called longitudinal direction because it is parallel to a longitudinal side of a vehicle, the Y direction

) is a transverse direction because it is perpendicular to the longitudinal sides of the vehicle and therefore perpendicular to the longitudinal direction X, and the direction Z is a vertical direction, perpendicular to the longitudinal direction X and transverse Y. FIG. 1 diagrammatically illustrates a part of a vehicle optical block BO (here a front light) comprising a lighting device DE according to the invention.

As illustrated, this optical block BO includes a BB housing 5 secured to a portion of the bodywork CV of a vehicle (here in a left front part).

The BB housing is made of a rigid material, such as a plastic or synthetic material. In this case, it can be made by molding. This BB box delimits a portion of a cavity housing a lighting device DE according to the invention, as well as any other lighting means providing at least one other photometric function.

As illustrated in FIG. 1, a lighting device DE according to the invention comprises at least one light source SL and one screen EC.

The light source SL is capable of delivering photons at a predefined location EP which must provide at least one photometric function.

This light source SL comprises at least one photon generator, such as for example a light-emitting diode (or LED ("Light-Emitting Diode")), optionally of organic type (or OLED

) ("Organic Light-Emitting Diode"). Alternatively, each photon generator could be a laser diode.

It will be noted, although this does not appear in FIG. 1, that each photon generator may, for example, be installed on a support plate. This support plate may, for example, be a circuit board

5 printed, PCB type ("Printed Circuit Board"), rigid or flexible ("type" Flex ").

As illustrated without limitation in FIG. 1, the light source SL may also comprise a light guide GL capable of transferring the photons, generated by the photon generator (s) and received on an input side, to a front face FV which is located just before the predefined place EP and which is able to transfer these photons in the latter (EP). This input face is for example located at one end of the light guide GL.

For example, the light guide GL can be realized in polycarbonate (or PC) or polymethylmethacrylate (or PMMA).

In order to optimize the delivery of the photons in the predefined spot EP located in front of the front face FV of the light guide GL, the lighting device DE may comprise a reflector RL partially surrounding this

5 (GL) on the side of a rear face opposite to its front face FV. This reflector RL can be made by molding in a plastic or synthetic material, for example of white color.

When the lighting device DE is part of an optical block BO, the reflector RL is secured to an inner face of the housing BB which delimits a

) part of the aforementioned cavity.

The EC screen is placed in front of the predefined location EP and comprises an alternation of first Z1 and second Z2 zones. Here, "alternation" is understood to mean a series of type Z1, Z2, Z1, Z2, Z1, Z2, as shown in non-limiting manner in FIG. 2.

Each first zone Z1 has a first light transmission coefficient ct1. Each second zone Z2 has a second light transmission coefficient ct2 which is strictly less than the first light transmission coefficient ct1 (ie ct2> ct1). Thus, the light that results (or is constituted) photons crossing each

) first zone Z1 has an intensity which is strictly greater than the intensity of the light which results (or is constituted) photons passing through each second zone Z2. This makes it possible to define a luminous band BL comprising an alternation of portions of "strong" intensity and "weak" (or even zero) intensity, as in the example illustrated without limitation on the

5 figure 2.

For example, the first zones Z1 may have a first color and the second zones Z2 may have a second color.

By way of example, the first color may be a so-called transparent white crystal color and the second color may be opaque black, as in the example shown non-limitatively in FIG. 2. But other combinations of first and second colors , respectively offering the first ct1 and second ct2 light transmission coefficients, can be envisaged according to the photometric function (s) to be ensured. The definition of the first Z1 and second Z2 zones can be done in different ways. Some of these ways are described hereinafter as non-limiting examples.

For example, the EC screen may be a room in which the

First 5 zones Z1 are made of a first plastic material having the first color and the second zones Z2 are made of a second plastic material having the second color. Such an EP piece may, for example, be made by molding.

In this case, the EC part can, for example and as illustrated no

) limitatively in Figure 1, comprising first SP1 and second SP2 subparts respectively made in the first and second plastics. The first subpart SP1 is secured to at least a portion of an outer face of the second subpart SP2. This external face is oriented opposite the predefined place EP, that is to say towards

5 outside the optical block BO. The second subpart SP2 comprises through holes TT located in front of portions of the first subpart SP1 which respectively define the first zones Z1.

It will be understood that the portions of the second subpart SP2 which are solid and therefore which surround the through holes TT define

) second zones Z2. The photons can thus pass freely from the predefined space EP to the first zones Z1 of the first sub-part SP1 via the through-holes TT, then through these first zones Z1 in order to emerge outside the optical block BO (in front of the face external of the first sub-part SP1 and thus of the screen EC). On the other hand, when photons hit

A second zone Z2 which is opaque (ie ct2 = 0), they are absorbed or reflected towards the predefined space EP, which allows that they are then reflected by the reflector RL to first zones Z1.

Such a piece EC can for example be made by injection molding of two materials of different colors.

) In an alternative embodiment not shown, the screen EC may be a plastic part or glass having the first color and having a face (preferably internal) provided with inserts having the second color and defining the second areas Z2. These elements can, for example, be defined by pad printing (for example with ink), or else be joined pieces by bonding, possibly thermally.

Note that when the lighting device DE is part of an optical block BO, the screen EC can cooperate with the housing BB to define the cavity, in particular in a front part, as illustrated without limitation in FIG.

The invention offers several advantages, among which:

it makes it possible to obtain a bulk, in the general direction of photon propagation, smaller than that of a lighting device of the prior art, because of the absence of a mask with holes,

it avoids the formation of condensation due to the absence of a mask with holes between the light source and the screen,

it makes it possible to obtain a better light output because the light source is closer to the screen because of the absence of a mask with holes,

it avoids the problems of positioning the screen due to the absence of a mask with holes,

it makes it possible to simplify the assembly of the lighting device and its possible integration into an optical unit, because of the absence of a mask with holes.

Claims

1. Illumination device (DE) comprising a light source (SL) capable of delivering, in a predefined area (EP), photons which must have at least one photometric function, characterized in that it further comprises a screen (EC) placed in front of said predefined location (EP) and comprising an alternation of first (Z1) and second (Z2) zones, defining a light band (BL), the first (Z1) and second (Z2) areas respectively having a first transmission coefficient and a second coefficient of light transmission strictly less than said first light transmission coefficient, so that the light resulting from the photons passing through each first zone (Z1) has an intensity strictly greater than the intensity of the light resulting from the photons passing through each second zone (Z2).

2. Device according to claim 1, characterized in that said first zones (Z1) have a first color and said second zones (Z2) have a second color.

3. Device according to claim 2, characterized in that said first color is a color called transparent white crystal and said second color is opaque black.

4. Device according to one of claims 2 and 3, characterized in that said screen (EC) is a part in which said first zones (Z1) are made in a first plastic material having said first color and said second zones (Z2 ) are made of a second plastic material having said second color.

5. Device according to claim 4, characterized in that said piece (EC) comprises first (SP1) and second (SP2) subparts respectively formed in said first and second plastics, said first subpart (SP1) being further secured to at least a portion of an outer face of said second sub-portion (SP2) facing away from said predefined location (EP), and said second sub-portion (SP2) including through-holes ( TT) in front of portions of said first subpart (SP1) which respectively define said first zones (Z1).

6. Device according to one of claims 2 and 3, characterized in that said screen (EC) is a plastic part or glass having

Said first color and having a face provided with inserts having said second color and defining said second areas (Z2).

7. Device according to one of claims 1 to 6, characterized in that said light source (SL) comprises at least one light emitting diode.

8. Device according to claim 7, characterized in that said light source (SL) comprises a light guide (GL) capable of transferring said generated photons, received on an input face, to a front face (FV ) located just before said predefined place (EP) and adapted to transfer these photons in the latter (EP).

9. Vehicle optical block (BO), characterized in that it comprises at least one lighting device (DE) according to one of the preceding claims.

10. Vehicle, characterized in that it comprises at least one optical block (BO) according to claim 9.