Patent Description:
Optical devices are used in automobiles and the like, for lighting the path ahead and also for providing signaling functions. These lighting functions includes low beam light, high beam lights, turn indicator, parking/position lamp, tail/ stop lamp, day running lights (DRL), fog lamp and/ or signature lamp. Most of the modern optical devices use light guides that are attached facing one or more light source. The light produced by these light sources enters the light guide through a light entry portion and is propagated through the light guide by multiple total internal reflection. In optical devices having more than one lighting functions, different light guides each associated with a specific function may be provided, for example individual light guides associated with an amber light source and a white light source for turn indicator and DRL function may be provided.

A known optical device is disclosed in <CIT>.

The optical devices using light guides are known to be affected by light leakage issues. The leakage may affect the optical efficiency of the optical device further affecting the lighting function as well. It is paramount in optical devices disclosed above (specifically having multiple light guides) that the light from one light guide does not leak to the other light guide. The leakage may affect the lighting functionality and may create a safety issue due to light mixing, especially light color mixing. Further, the light leakage may affect the visual styling of the vehicle headlamp which may be perceived negatively by the user. Some optical devices may be designed such that the light guides need to cross each other in a physical plane. This crossing of light guides is needed in order to fulfil the requirements pertaining to light guide curvature and also to meet regulation. In such optical devices the light leakage is a huge issue and may aggravate the above disclosed issues.

To overcome the said issues some optical modules are provided with a cover that are configured to cover a portion of the light guide. These covers are usually fixed to the housing or a mask by means of clipping structures such as press clips or snap fit clips. These covers are able to prevent light leakage that can be viewed outside the headlamp. However they are not effective in preventing light leakage between multiple light guides in the optical devices. Further, the cover having clipping structures may involve assembly constraints and may not be able to properly fit to the housing and may not be able to arrest the movement of the cover during harsh vehicle operation conditions leading to failure.

The prior art and the conventional methods have various disadvantages as described earlier and there is a need for an optical device that can overcome the issues of the prior art to prevent light leakage between the light guides.

An object of the present invention is to solve the disadvantages described above of known optical devices. In particular, it is the object of the present invention to provide an optical device that can prevent light leakage between the light guides of the optical device. The present invention provides an optical device as defined in claim <NUM> and an assembly process as defined in claim <NUM>.

According to the present invention, an optical device for an automotive vehicle comprises at least one light source configured to produce a light beam, at least one light guide configured to propagate said light beam. The at least one light guide includes a light entry portion arranged facing the at least one light source to receive said light beam. Further, the optical guide comprises at least one support structure configured to support the at least one light guide and at least one cover assembled with the at least one support structure configured to cover the light entry portion of the at least one light guide. The at least one cover and the at least one support structure create a hinge in an assembled state, further, the hinge is configured to rotatably secure the at least one cover and the at least one support structure around a hinge axis. The cover is arranged over the light entry portion light guide thus masking light leakage from the said face of the light guide from being visible. Further, the hinge allows rotational movement that allows the cover to rotate about the hinge axis providing ease of assembly.

Further, the rotation of the hinge allows the light guide to be assembled easily in the optical device.

In an embodiment of the present invention, the at least one cover comprises a first hinge portion configured to be assembled relative to a second hinge portion of the at least one the support structure. The respective hinge portions on the cover and the support structure may enable the assembly to prevent fouling of components while assembly and whilst securing the cover over the at least one light guide.

In an embodiment of the present invention, the first hinge portion includes at least one supporting leg having plurality of pins that extend from the supporting leg along the hinge axis. The plurality of pins extending from the supporting leg allows the first hinge portion to be flexible such that the supporting legs move relative along the hinge axis.

In an embodiment of the present invention, the second hinge portion includes plurality of slots formed in the at least one support structure. The plurality of slots enables the support structure to be constructed with a simple design which allows ease of manufacture. Further, the slots may enable robust structure that can with stand the stress.

In an embodiment of the present invention, the plurality of pins are configured to mate with the plurality of slots. The plurality of pins when mated with the plurality of slots enables the cover to be assembled with the support structure such they rotate along the hinge axis and further, preventing any translational movement between the cover and the support structure.

In an embodiment of the present invention, the hinge further comprises a hinge channel extending tangentially from the hinge. The hinge channel guides the first hinge portion towards the second hinge portion during assembly. The hinge channel may compress the first hinge portion whilst assembly. Thus enabling quick assembly of the cover with respect to the support structure, in addition, the channel prevents assembly errors during assembly.

In an embodiment of the present invention, the first hinge portion comprises a pin and a supporting leg extending from said pin. The supporting leg may allow the first hinge portion to be flexible, thus allowing ease of assembly. Further, the pin may allow to act as a male connection member in an assembly.

In an embodiment of the present invention, the supporting leg comprises a longitudinal slot. The longitudinal slot may prevent the translational movement in an assembled state, thus, restricting the degrees of freedom of the assembly.

In an embodiment of the present invention, the second portion comprises at least one knuckle configured to mate with the pin.

In an embodiment of the present invention, the at least one knuckle comports a plurality of arms configured to surround the pin. The plurality of arms may help the knuckle to assemble to a second component and they can easily assembled using press force.

In an embodiment of the present invention, at least one of the arm of the knuckle is configured to pass through said longitudinal slot. When the knuckle is passed through the longitudinal slot, it may prevent the movement of the assembly in all the directions other than a rotational movement about the hinge axis.

In an embodiment of the present invention, the at least one support structure and the at least one cover are integrally formed having a flexible portion configured to allow relative rotation between the at least one support and at least one cover. This may enable the cover and the support structure to be manufactured as a single part, hence reducing the manufacturing time as well as assembly time as the need for assembling the cover and the support structure is avoided.

In an embodiment of the present invention, the at least one cover includes at least one segment adapted to surround a portion of the at least one light guide. The at least one segment may be adapted to the shape and curvature of the light guide, thus allowing a compact and flush assembly of the cover and the light guide.

According to the present invention, the optical device comprises at least two light guides and at least two light sources, and further, each of the light guides is arranged facing respectively one of the at least two light sources. Each of the light guide along with the respective light sources may enable using different lighting functions such as turn indicator and day running light functions. In an alternate embodiment, the optical device may include a single light guide arranged facing a single or plurality of light sources. In said configuration, the optical device may be configured to perform a single lighting function or different lighting functions.

According to the present invention, the least one cover comprises at least two structures provided on opposite sides of the at least one cover.

In an embodiment of the present invention, the at least one cover further comprises a clipping structure configured secure the at least one cover on the at least one support structure. The clipping structure secures the cover arresting the translational movement of the cover when the cover is assembled over the light guide.

In an embodiment of the present invention, the at least one support structure comprises locking structure configured to mate with the clipping structure. The locking structure may be configured to hold the clipping structure thus securing the cover securely.

In an embodiment of the present invention, the optical device further comprises a bezel configured to hide a portion of the light guides. The bezel may hide provide additional styling to the optical device. In an alternate embodiment, the cover may be designed as the bezel elements and may be configured to cover at least a part of the light guide. In other words, the bezel may be designed to create a hinge with the at least one support structure in an assembled.

According to the present invention, an assembly process for assembling at least one cover on at least one support structure of an optical device is envisioned, said assembly process comprises the steps of providing a first light guide on the at least one support structure of the optical device, further, a light entry portion of the first light guide is arranged facing a light source. The assembly process further comprises the step of providing at least one cover on said support structure. The at least one cover is configured to form a hinge with the at least one support structure. Further, the assembly comprises the step of rotating the at least one cover about a hinge axis to cover the light entry portion of the at least one light guide. The assembly process allows an easy and secure assembly of the cover on the support structure and further preventing light leakage from the light guides.

According to the present invention, the assembly process further comprises a step of providing a second light guide over the at least one cover. The second light guide assembled over the at least one cover enables the light guides to be placed on the opposite side of the cover, thus preventing light leakage between the two light guides.

In an embodiment of the present invention, the assembly process further comprises a step of securing the at least one cover on the support using a clipping structure. Securing the cover using the clipping structure enables arresting the translational movement of the cover when the cover is assembled over the light guide.

In an embodiment of the present invention, the assembly process comprises a step of providing a bezel for hiding a portion of the first light guide and the second light guide. Assembling the bezel may hide provide additional styling to the optical devices.

To complete the description and to provide a better understanding of the invention, a set of drawings is provided. Said drawings form an integral part of the description and illustrate an embodiment of the invention, which should not be construed as restricting the scope of the invention, but only as an example of how the invention can be carried out. The drawings comprise the following characteristics.

<FIG> shows an optical device for an automotive vehicle according to an embodiment of the present invention. The optical device <NUM> of the present invention comprises at least one light source <NUM> (as seen in <FIG>) configured to produce a light beam. The light beam produced by the light sources may be used for various lighting functions such as low beam light, high beam lights, turn indicator, parking/position lamp, tail/ stop lamp, day running lights (DRL), fog lamp and/ or signature lamp. In said optical device <NUM>, the light sources <NUM> may be of amber and white color respectively to achieve the above said functions. Alternatively, the light sources <NUM> may be of red color to achieve stop lamp or tail lamp function, further, the light sources <NUM> may be adapted to achieve fog lamp function as well. Further as shown in <FIG>, the optical device <NUM> may comprise at least one light guide <NUM> configured to propagate said light beam. In addition, the at least one light guide <NUM> includes a light entry portion arranged facing the at least one light source <NUM> to receive said light beam. The light beam that enters the at least one light guide <NUM> through the light entry portion may be propagated towards a light exit portion (not shown) of the light guide <NUM> by means of multiple total internal reflection. The light beam exiting from said exit portion may be viewable from outside the optical device <NUM> to carry out the desired lighting function.

Light guides are usually supported by a light guide support structure which may be further supported on a housing of the optical device. In some cases the support structure may also function as a mask that may be configured to mask a other components of the optical device. In an embodiment of the present invention, as seen in <FIG> and <FIG>, the optical device <NUM> further comprises at least one support structure <NUM> configured to support the at least one light guide <NUM>. The support structure <NUM> may allow supporting the at least one light guide <NUM> with respect to the light sources <NUM>. The light guide <NUM> are arranged such that optimal distance is maintained between the light sources and the at least one light guide <NUM>. The optimal distance signifies the best possible position of the light guide with respect to the light sources so as to allow optimized or maximized amount of light beam produced by the light source <NUM> transmitted through the entry portion.

In addition, the optical device <NUM> may comprise at least one cover <NUM> that is assembled with the at least one support structure <NUM> and may be configured to cover the light entry portion of the at least one light guide <NUM>. The at least one cover <NUM> is a physical structure or part that may be assembled over the specific portion of the light guide <NUM> so that the light guide may not be visible from outside the optical device <NUM>. In a preferred embodiment as shown in <FIG>, the at least one cover <NUM> and the at least one support structure <NUM> create a hinge <NUM> in an assembled state. A hinge may be defined as a mechanical bearing that is used to connect two solid part, typically allowing only a limited angle of rotation between them. The two parts connected by a hinge rotate relative to each other about a fixed axis of rotation. All other translations or rotations are prevented, and thus a hinge has limited degree of freedom. In such parts tolerance are provided to allow limited movement between the mating or assembled parts. The limited movement may signify the movement between the parts in assembled state. The limited movement may enable ease of assembly and may prevent any damage to the parts. It is understood that an ideal hinge only allows the rotation about a fixed axis of rotation, as mentioned above. However, on real products, tolerances are necessary, and the rotation or translation movements allowed by theses tolerances should not be considered as degrees of freedom. Thus, it can be considered that the hinge only has one rotation degree of freedom. Conventionally, hinges consists of three components namely, pin, knuckle and leaf and may be made of flexible material or of moving components. In a preferred embodiment of the present invention, the hinge <NUM> is configured to rotatably secure at least one cover <NUM> and the at least one support structure <NUM> around a hinge axis A-A' and further prevent translational movement of the at least one cover <NUM> with respect to the at least one support structure <NUM>.

In an embodiment of the present invention as shown in <FIG>, at least one cover <NUM> comprises a first hinge portion <NUM> that is configured to be assembled relative to a second hinge portion <NUM> of the at least one the support structure <NUM>. Further, the first hinge portion <NUM> includes at least one supporting leg <NUM> having plurality of pins <NUM> that extend from the supporting leg <NUM> along the hinge axis A-A' and the second hinge portion <NUM> includes at least one slot <NUM> formed in the at least one support structure <NUM>. The at least one supporting leg <NUM> may be connected to the at least one cover <NUM> and may extend away from the at least one cover <NUM>. Further, the plurality of pins <NUM> may be provided as a cantilever shaft projecting from the at least one supporting leg <NUM>. As seen in <FIG>, the first hinge portion <NUM> may include two pins <NUM> that are extending away and opposite to each other along the hinge axis A-A'. The least one leg <NUM> may be flexible to enable easy assembly of the at least one cover <NUM> and the support structure <NUM>. As shown in <FIG>, in a preferred embodiment of the present invention, the first hinge portion <NUM> includes two supporting legs <NUM> that are connected to the at least one cover <NUM>. Further, an end of the each of supporting legs <NUM> comprises a pin <NUM> that project from the supporting leg <NUM> along the hinge axis A-A'. In the shown embodiments the pins <NUM> are arranged facing away from each other, alternatively, the pins <NUM> can also be arranged facing towards each other as well.

According to the present invention, the pins <NUM> may be configured to mate with the at least one slot <NUM>. The plurality of pins <NUM> when mated with the at least one slot <NUM> prevents translational movement of the at least one cover <NUM> but allows rotational motion of the at least one cover <NUM> around the hinge axis A-A'. The flexible nature of the supporting legs <NUM> allows the legs to be compressed during assembly so as to mate the pins <NUM> with the at least one slot <NUM>. Once the pins <NUM> are mated with respective slots <NUM> the supporting legs are configured to return to its normal state. In a preferred embodiment, the hinge <NUM> comprises a hinge channel <NUM> extending tangentially from the hinge <NUM>. The hinge channel <NUM> guides the first hinge portion <NUM> towards the second hinge portion <NUM> during assembly. The hinge channel may be designed such that the first hinge portion <NUM> gets compressed when entering the hinge channel <NUM>. Further, the hinge channel <NUM> may end just before the at least one slot of the second hinge portion <NUM>. The first hinge portion <NUM> when exiting said channel regains its shape and may be locked inside the at least one slot of the second hinge portion <NUM>.

In an alternate embodiment of the present invention as shown in <FIG>, the first hinge portion <NUM>' comprises a pin <NUM>' and a supporting leg <NUM>' extending from said pin <NUM>'. The supporting leg <NUM>' may be attached to the at least one cover <NUM> and the pin <NUM>' may be configured to mate with the second hinge portion <NUM>. Further, the supporting leg <NUM>' may comprises a longitudinal slot 52a. In said embodiment the second portion <NUM> comprises at least one knuckle configured to mate with the pin <NUM>'. The knuckle may include at least one arm 54a that may be configured to surround the pin <NUM>' to secure the at least one cover <NUM> to the at least one support structure <NUM>. Once the at least one arm 54a are assembled against the pin <NUM>' a hinge <NUM> may be created between the at least one cover <NUM> and the supporting structure <NUM>. Further, the at least one arm 54a of the knuckle may configured to pass through said longitudinal slot 52a to allow ease of assembly and prevent translational movement of the at least one cover <NUM>.

In an alternate embodiment, the at least one support structure <NUM> and the at least one cover <NUM> are integrally formed having a flexible portion configured to allow relative rotation between the at least one support structure <NUM> and at least one cover <NUM>. The flexible portion may be made of a malleable material to provide flexibility to said flexible portion. Alternatively, the flexible portion may be made having a portion with a reduced or lower thickness, compared to at least one support structure <NUM> and at least one cover <NUM>, to provide flexibility to said flexible portion. Further, the flexible portion may be made as below to accommodate the rotational motion of the cover <NUM> during assembly.

<FIG> shows a preferred embodiment of the at least one cover <NUM>. As seen in the <FIG>, the at least one cover <NUM> includes at least one segment <NUM> adapted to surround a portion of the at least one light guide <NUM>. The at least one segment <NUM> may be designed to match the profile and curvature of the at least one light guide <NUM>. Conventionally, the light guide <NUM> may be supported on the supporting structure <NUM> by dedicated support means such. Whereas, the at least one segment <NUM> may provide additional support to the at least one light guide inside optical device <NUM>. Further, the at least one guide portion <NUM> may also acts as shield to prevent light leakage from being visible from outside and also from leaking into other light guide. As seen in said <FIG> at least one guide portion <NUM> is an integral rib structure formed substantially perpendicular to the planar surface of the at least one cover <NUM>. In an alternate embodiment, the at least one segment <NUM> may be metalized or provided with reflective material so that the at least one segment <NUM> acts as an reflector to reflect any light beam back towards the at least one light guide <NUM>.

According to the invention, the optical device <NUM> comprises at least a first light guide <NUM>, and a second light guide <NUM>', configured to propagate light from at least two light sources <NUM>. As described earlier, the two light guides <NUM>, <NUM>' may be associated with two light sources <NUM> such as amber color light source and white color light source for enabling turn indicator function and day running light function respectively. More in detail, the first light guide <NUM> is associated with an amber color light source, and the second light guide <NUM>' is associated with an white color light source, or opposite. Alternatively, both light guides may be associated each respectively with at least one amber color light source and one white color light source. In said embodiment, the at least one cover <NUM> comprises at least two segments <NUM>, <NUM> provided on opposite sides of at least one cover <NUM>. The two light guides <NUM>, <NUM>' of the optical device <NUM> are surrounded by the respective segment <NUM>, <NUM>. The first light guide <NUM> is surrounded by the segment <NUM> and the second light guide <NUM>' is surrounded by the segment <NUM>. Alternate arrangements of the light guide <NUM>, <NUM>' with respect to the segments <NUM>, <NUM> is also possible and may be provided in an alternate embodiment. As the segments <NUM>, <NUM> are on opposite sides of the at least one cover <NUM>, the light from the first light guide <NUM> does not leak into the second light guide <NUM>', and the light from the second light guide <NUM>' does not leak into the first light guide <NUM>.

The at least one cover <NUM> as seen in <FIG> further comprises a clipping structure <NUM> configured secure the at least one cover <NUM> on the at least one support structure <NUM>. The at least one support structure <NUM> comprises locking structure <NUM> (seen in <FIG>) that may be configured to mate with the clipping structure <NUM>. The clipping structure <NUM> and locking structure <NUM> may be designed to act as a press fit mechanism or a snap fit mechanism or similar connection means. Once the clipping structure is locked in the locking structure <NUM> the rotational motion of the cover can be arrested. The clipping structure <NUM> and locking structure <NUM> are designed such that they can not be separated easily. In an embodiment of the present invention, to meet the styling requirements of the optical device <NUM> may further comprise a bezel that may configured to hide a portion of the light guides.

An assembly process for assembling the at least one cover <NUM> on at least one support structure <NUM> of an optical device <NUM> according to an embodiment of the present invention is described below. The assembly process comprises the steps of providing a first light guide <NUM> on the at least one support structure <NUM> of the optical device <NUM>. The first light guide is provided such that a light entry portion <NUM> of the first light guide <NUM> is arranged facing a light source <NUM>. The distance between the first light guide <NUM> and the light source <NUM> may be maintained such that optimized or maximized amount of light beam produced by the light source <NUM> is transmitted through the entry portion <NUM>. Further, at least one cover <NUM> may be provided on said support structure <NUM>. The at least one cover <NUM> may be configured to form a hinge <NUM> with the at least one support structure <NUM>. As disclosed earlier, the hinge <NUM> comprises a first hinge portion <NUM> and a second hinge portion <NUM>. Additionally, the first hinge portion <NUM> may be guided by hinge channel <NUM> towards the second hinge portion <NUM>. Once the first hinge portion <NUM> is assembled with the second hinge portion <NUM>, the at least one cover <NUM> may be rotated about a hinge axis A-A' to cover the light entry portion <NUM> of the first light guide <NUM>.

Further, the assembly process comprises a step of providing a second light guide <NUM>' over the at least one cover <NUM>. The second light guide <NUM>' is provided on the opposite side of the at least one cover <NUM> as compared to the first light guide <NUM>. Similar to the first light guide <NUM>, light entry portion <NUM>' of the second light guide <NUM>' is arranged facing another light source <NUM>. In addition, the at least one cover may be secured on the support using a clipping structure that are configured to mate with locking structures of the at least one support structure <NUM>. In addition, a bezel may be provided for hiding a portion <NUM> of the first light guide <NUM> and the second light guide <NUM>'.

Claim 1:
An optical device (<NUM>) for an automotive vehicle comprising:
at least one light source (<NUM>) configured to produce a light beam;
at least one light guide (<NUM>) configured to propagate said light beam, wherein the at least one light guide (<NUM>) includes a light entry portion arranged facing the at least one light source (<NUM>) to receive said light beam;
at least one support structure (<NUM>) configured to support the at least one light guide (<NUM>);
at least one cover (<NUM>) assembled with the at least one support structure (<NUM>) configured to cover the light entry portion of the at least one light guide (<NUM>),
wherein the optical device (<NUM>) comprises at least two light guides (<NUM>, <NUM>') and at least two light sources (<NUM>), and wherein each of the light guides (<NUM>, <NUM>') is arranged facing respectively one of the at least two light sources (<NUM>);
characterized in that the at least one cover (<NUM>) and the at least one support structure (<NUM>) create a hinge (<NUM>) in an assembled state, and wherein the hinge (<NUM>) is configured to rotatably secure the at least one cover (<NUM>) and the at least one support structure (<NUM>) around a hinge axis (A-A')
wherein the at least one cover (<NUM>) comprises at least a first and a second two structure (<NUM>, <NUM>) provided on opposite sides of the at least one cover (<NUM>), and
wherein the first light guide (<NUM>) is surrounded by the first structure (<NUM>) and the second light guide (<NUM>') is surrounded by the second structure (<NUM>).