FR3039250A1 - OPTICAL ELEMENT WITH MONOBLOC PIECE, FOR AN OPTICAL BLOCK WITHOUT ICE - Google Patents

Abstract

An optical element (EO) equips an optical block (BO) without ice and comprises a source (SP) delivering photons intended to participate in at least one photometric function, a one-piece piece (PM), made of a material transparent to photons, and comprising an input face (FE) allowing the input of an internal zone (ZI) of the delivered photons, a rear face (FR) adapted to reflect towards the internal zone (ZI) the delivered photons which are input by the face input (FE), and a front face (FV) constituting an output face (FS) of the optical block (BO) and adapted to deliver outgoing photons having been previously reflected by the rear face (FR). At least the rear (FR) and front (FV) faces have predefined shapes that together make the outgoing photons suitable for the photometric function.

Description

The invention relates to ice-free optical blocks, optionally for vehicles.

As known to those skilled in the art, the use of ice (glass or plastic) at the output of an optical unit induces optical losses of 10% to 15%. It has therefore recently been proposed to manufacture certain optical blocks without ice, and more specifically to use their lens not only as an optical element participating in at least one photometric function, but also as a protective element defining the face. Release. In this case, the optical unit generally comprises a source of photons coupled to a reflector, a lens (generally aspherical), and at least one cover ensuring the connection between the reflector and the lens and the sealing vis-à-vis the lights external parasites, dust and water (including moisture and condensation). A seal also ensures the sealing of the optical block at the interface between its lens and the front end of its cover.

With such an architecture, this type of optical unit remains relatively bulky in the longitudinal direction, and its sealing is difficult in practice to obtain, especially at its output face (defined by the front of its lens). The purpose of the invention is in particular to improve the situation.

It proposes for this purpose an optical element intended to equip an optical block without ice and comprising a source for delivering photons intended to participate in at least one photometric function. This optical element is characterized by the fact that: it comprises a one-piece part, made of a material transparent to photons, and comprising an input face arranged so as to allow entry into an internal zone of the delivered photons, one face rear arrangement arranged so as to reflect towards the inner area the delivered photons which are input by the input face, and a front face intended to constitute an output face of the optical block and adapted to deliver outgoing photons having been previously reflected by the rear face, and - at least the rear and front faces of the one-piece piece have predefined shapes to make together the outgoing photons adapted to the photometric function.

With this compact optical element, it is now possible to manufacture a more compact optical unit (in particular in a longitudinal direction), and whose sealing is easier to achieve because its sealing area is smaller. The optical element according to the invention may comprise other characteristics that may be taken separately or in combination, and in particular: the rear face and the front face may be convex relative to the outside; - The input face may have a predefined shape to make, with the predefined shapes of the rear face and front face, the outgoing photons adapted to the photometric function; - the inner zone can be full. Alternatively, the inner zone may comprise a housing also having a predefined shape adapted to make, with the shapes of the rear face and front face and possibly with a predefined shape of the input face, the outgoing photons adapted to the function photometric; the rear face may be provided with a reflective layer on an outward facing external side; the material may be chosen from (at least) a glass and a plastics material. The invention also proposes an optical block without ice and comprising a source capable of delivering photons intended to participate in at least one photometric function, a support on which the source is secured, and an optical element of the type of that presented above. and having its input face secured to the support facing the source, with the interposition of at least one seal. The invention also proposes a vehicle, possibly of automobile type, and comprising at least one optical block of the type of that presented above. Other characteristics and advantages of the invention will appear on examining the detailed description below, and the accompanying drawings, in which: - Figure 1 schematically illustrates in a sectional view in a vertical plane XZ , a first example of an optical block comprising a first exemplary embodiment of an optical element according to the invention, and - Figure 2 schematically illustrates, in a sectional view in the vertical plane XZ, a second example of an optical block. comprising a second embodiment of an optical element according to the invention. The object of the invention is notably to propose an optical element EO intended to equip an optical block BO without ice.

In what follows, it is considered, by way of non-limiting example, that the optical block BO is intended to equip a motor vehicle, such as a car. But the invention is not limited to this application. Indeed, an optical block BO, according to the invention, can equip any type of system or installation that can be equipped with a lighting device. Thus, it concerns any type of vehicle, land, sea (or fluvial), or air, and buildings, in particular.

Furthermore, it is considered in the following, by way of non-limiting example, the optical block BO is a headlight (or front projector). But the invention is not limited to this type of optical block. Thus, it also relates to the rear lights. In general, the invention relates to any optical block that fulfills at least one photometric function. In the case of a vehicle, the photometric function may relate to the lighting, or the signaling of the vehicle or event relating to the vehicle, or an aesthetic light function. By way of nonlimiting example, a photometric lighting function may be a low beam function (or code), a fog lamp function, or a high beam function.

Also as a non-limiting example, a photometric signaling function may be a function of a change of direction indicator (or flashing), a brake light function, a position light function (or night light or lantern) , a daylight running function (or DRL (for "Daytime running Light (or Lamp)" - light signaling automatically switched on when the vehicle is in operation during the day), or a welcome function (or courtesy ).

In the figures, the direction X is a so-called longitudinal direction, substantially parallel, here, to the lateral sides of a vehicle which respectively comprise the side doors (or doors), the Y direction is a so-called transverse direction, perpendicular to the longitudinal direction X (and thus here at the lateral sides of the vehicle), and the direction Z is a so-called vertical direction, perpendicular to the longitudinal direction X and transverse Y.

FIGS. 1 and 2 show schematically two examples of optical block BO comprising different embodiments of optical elements EO according to the invention.

As illustrated, these optical blocks BO each comprise a support SS, a source of photons SP, at least one seal JE, and an optical element EO.

It will be noted that in the examples illustrated in non-limiting manner in FIGS. 1 and 2, the optical blocks BO only provide a single lighting function. But they could provide at least one other lighting function and / or a signaling function of the vehicle or event related to the vehicle.

The source of photons SP is firmly fixed to the support SS and arranged to deliver photons which are intended to participate in at least one photometric function.

For example, the photon source SP may comprise at least one light emitting diode (or LED). As a variant, it may comprise at least one laser diode or a lamp (or bulb).

The support SS may, for example, comprise a base intended to be fixedly secured (here) to a vehicle, and an integrated circuit board on which is secured the source (photons) SP and comprising the control and power means of the latter (SP). The optical element EO mainly comprises a monoblock piece PM which is made of a material transparent to photons, at least in a selected spectral band, for example that comprising wavelengths belonging to the visible spectrum. But alternatively, this material could also be or alternatively transparent to ultraviolet (UV) or infrared (IR) photons, especially for night vision.

For example, this material may be a glass or a plastic material, possibly synthetic, such as polymethyl methacrylate (or PMMA), polycarbonate (PC), or polyacrylate.

The monoblock piece PM may, for example, be made by molding. But, it could also be done by machining, for example.

Furthermore, the one-piece piece PM comprises an entry face FE, a rear face FR and a front face FV which together delimit an internal zone ZI.

The input face FE is intended to be secured to the support SS facing the source SP, and is arranged to allow entry into the internal zone ZI photons that are delivered by this source SP. It will be noted that this input face FE may, optionally and as illustrated without limitation in FIG. 1, comprise a concave zone ZC whose utility will be understood later.

The attachment of the optical element EO to the support SS can be done by various means, and in particular by MF screws (for example two three or four). The use of MF screws requires that threaded holes are defined in the material defining the internal zone ZI. As a variant, this joining could be by overmolding or gluing, for example.

The rear face FR is arranged so as to reflect towards the internal zone ZI the photons which have been delivered by the source SP and which have entered the internal zone ZI by the input face FE.

For example, and as illustrated without limitation in FIGS. 1 and 2, this rear face FR may be provided with a reflective layer CR on an outwardly facing outer side (of the rear side of the optical block BO). This reflective layer CR may, for example, be a metallization carried out by a deposit. But alternatively it could be an opaque paint layer (eg black). It should be noted that any technique known to those skilled in the art and making it possible to make the rear face FR reflective can be used here. Thus, one could also define microstructures, two-dimensional (2D) or three-dimensional (3D), for example.

The front face FV is intended to constitute an output face FS of the optical block BO and is adapted to deliver outgoing photons having been previously reflected by the rear face FR. It will be understood that in the absence of protective glass is the front face FV of the optical element EO, which is located at the interface with the outside (the front side) and therefore which defines the face FS output of the optical block BO, which delivers outside photons outgoing participating in the photometric function. The optical element EO thus ensures the protection of the optical block BO, and therefore the material in which it is made must be very resistant, especially at its front face FV. To do this, the latter (FV) may have possibly undergone treatment. This treatment may, for example, be protective and / or anti-UV. It will be noted that, alternatively or in addition, this front face FV may be provided with optical microstructures intended to participate in the photometry, possibly of the outgoing light beam (for example to obtain a cutoff blur and / or an illumination of gantries (auto) road).

The front face FV defines a material / air diopter which induces a refraction of the incident photons.

It will be noted that in the illustrated examples, the outgoing photons define a lighting beam having an average propagation direction substantially parallel to the illumination direction of the optical block BO. But when the latter (BO) provides a signaling function the outgoing photons can have fairly different mean directions of propagation.

At least the rear faces FR and before FV have predefined shapes which are suitable for rendering the outgoing photons together adapted to the photometric function considered in the optical block BO. It will be noted that when the input face FE comprises a concave zone ZC as shown in non-limiting manner in FIG. 1, it has a predefined shape which is able to render, with the predefined shapes of the rear faces FR and front face FV, the photons outgoing adapted to the photometric function considered in the optical block BO. It will be understood that these different predefined shapes of the face differences FV, FR and possibly FE are calculated so as to participate together in the production of the outgoing photons. The shape of the optical element E0 is therefore calculated according to the type of photometric function to be performed. The concave zone ZC is also intended to optimize the injection of incoming photons into the internal zone ZI.

Note that in the examples illustrated without limitation in Figures 1 and 2 the rear face FR and front face FV have general convex shapes with respect to the outside. But at least one of them could have another general shape, possibly with multiple curvatures to obtain complex shapes, possibly with continuous surfaces. It will also be noted that the calculated forms may also be intended to correct chromatic aberrations.

The (each) seal JE is interposed between the entry face FE and the support SS. It may, for example, be a rubber ring, possibly synthetic, or elastomer. It will be understood that it is mainly this gasket JE which advantageously ensures the sealing of the optical unit (and in particular of its source SP and its control and supply means) vis-à-vis the external parasitic lights , dust and water (including moisture and condensation). This makes it much easier to obtain a quality seal. Note that it will also be interposera, preferably, another seal between the periphery of the front face FV and here the part of the body where this front face FV is fixedly installed.

Note also that the position of the optical element EO may be optionally adjustable in location and / or in azimuth. For this purpose, the position of its support SS may be optionally adjustable.

It will also be noted that in the example shown in non-limiting manner in FIG. 1, the internal zone ZI of the one-piece piece PM is full. But this is not obligatory. Indeed, in order to reduce substantially the weight of this monoblock piece PM, its internal zone ZI can, as shown nonlimitingly in Figure 2, comprise a housing (or recess) L. The latter (L) also has a predefined shape that is capable of rendering, with the predefined shapes of the rear face FR and front face FV and possibly of the entry face FE, the outgoing photons adapted to the photometric function considered in the optical block BO.

This predefined shape of the housing L is defined by a rear internal face F1, situated on the side of the rear face FR, and by a front internal face F2, situated on the side of the front face FV. It will be understood that these rear internal face F1 and front internal face F2 define two air / material dioptres which induce a refraction of the incident photons and therefore participate in the production of the outgoing photons, with at least the rear face FR and front face FV.

Claims (10)

1. Optical element (EO) for an optical block (BO) without ice and comprising a source (SP) capable of delivering photons intended to participate in at least one photometric function, characterized in that it comprises a single piece (PM ), made of a material transparent to said photons, and comprising an input face (FE) arranged to allow entry into an internal zone (ZI) of said delivered photons, a rear face (FR) arranged so as to reflect towards said internal zone (ZI) said delivered photons which are entered by said input face (FE), and a front face (FV) intended to constitute an output face (FS) of said optical block (BO) and able to deliver outgoing photons having been previously reflected by said rear face (FR), and in that at least said rear (FR) and front (FV) faces have predefined shapes suitable for rendering said outgoing photons adapted to said photometric function. 2. Optical element according to claim 1, characterized in that said rear face (FR) and front face (FV) are convex relative to the outside. 3. optical element according to one of claims 1 and 2, characterized in that said input face (FE) has a predefined shape to make, with said predefined shapes of the rear face (FR) and front face (FV) said outgoing photons adapted to said photometric function. 4. Optical element according to one of claims 1 to 3, characterized in that said inner zone (ZI) is full. 5. optical element according to one of claims 1 to 3, characterized in that said inner zone (ZI) comprises a housing (L) also having a predefined shape adapted to make, with said predefined shapes of the rear faces (FR) and front face (FV) and optionally with a predefined shape of said input face (FE), said outgoing photons adapted to said photometric function. 6. optical element according to one of claims 1 to 5, characterized in that said rear face (FR) is provided with a reflective layer (CR) on an outer side facing outwards. 7. optical element according to one of claims 1 to 6, characterized in that said material is selected from a group comprising a glass and a plastic material. An optical block (BO) without ice and comprising a source (SP) capable of delivering photons intended to participate in at least one photometric function, characterized in that it further comprises a support (SS) on which said source (SP), and an optical element (EO) according to one of the preceding claims, having its input face (FE) secured to said support (SS) facing said source (SP), with interposition of at least a seal (JE). Vehicle, characterized in that it comprises at least one optical block (BO) according to claim 8. 10. Vehicle according to claim 9, characterized in that it is automotive type.