Vehicle headlight assembly

A headlight assembly includes a housing, a light source, a light shielding plate, and a light guiding plate. The housing defines a compartment, and includes a reflector and a lens disposed in front of the reflector. The light source is mounted in the compartment and is disposed on an optical axis. The light shielding plate is mounted between the light source and the lens. The light guiding plate is disposed below the optical axis. A first portion of light beams emitted upwardly is reflected by the reflector, passes over the light shielding plate and through the lens, which refracts the first portion of the light beams to form a first illuminating pattern. A second portion of the light beams passes through the light guiding plate and through the lens, which refracts the second portion of the light beams to result in a second illuminating pattern that is directed forwardly and upwardly.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Taiwan application serial number 097100027 filed Jan. 2, 2008, the disclosure of which is expressly incorporated herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a headlight assembly, more particularly to a projector-type vehicle headlight assembly.

2. Description of the Related Art

A vehicle headlamp assembly is configured to provide road illumination to suit different road conditions and road visibility requirements. Currently, there exists a projector-type, or Poly-Ellipsoid System (PES) headlamp assembly.FIG. 1shows a conventional headlamp assembly, which includes a reflector61that defines a compartment610, a light source62mounted in the compartment610and disposed on an optical axis (x), a lighting shielding plate63extending upwardly from a bottom edge of the reflector and having a top edge that is flush with the optical axis (x), a housing (not shown) assembled in front of the reflector61. By virtue of the shielding effect of the light shielding plate63, the light beams reach and exit a region of the lens64that is below the optical axis (x). As a result, an illuminating pattern is formed. Even though the aforementioned vehicle headlamp assembly is capable of casting the illuminating pattern, the pattern cast thereby is heavily concentrated at a lower region (i.e., below the optical axis “x”), and causes an adjacent upper region (i.e., above the optical axis “x”) to suffer from inadequate light illumination.

In order to adequately illuminate on upper region that is 18 meters in front of the headlamp assembly, the headlamp assembly must be able to provide at least 64 candela (cd) of light intensity thereat. However, the aforementioned conventional vehicle headlamp assembly does not have enough power to cast such light intensity, which is detrimental for drivers to be not able to discern the overhead signs when driving at nighttime.

As illustrated inFIG. 2, U.S. Pat. No. 6,736,533 discloses a vehicular headlamp that has an auxiliary plate72provided in front of a shield plate71. The auxiliary plate72serves to reflect a portion of the descending light beams through a lens73. As a result of passing through the lens73, light beams A1radiate forwardly in an upward direction so as to enhance overall light intensity in the upper region. Referring toFIG. 3, U.S. Pat. No. 6,736,533 further teaches another vehicular headlamp that has an aperture810in the shield plate81, and an auxiliary plate82provided on an inner side of the shield plate81. This particular configuration can also achieve the effect of enhancing light intensity in the upper region.

Another conventional headlight is disclosed in U.S. Patent Application Publication No. 2001/0019484, which discloses a screen configuration that permits limited upper region illumination.

SUMMARY OF THE INVENTION

The object of the present invention is to provide vehicle headlight assembly that can form two illuminating patterns.

According to the present invention, a vehicle headlight assembly includes a housing, a light source, a light shielding plate, and a light guiding plate. The housing defines a compartment, and includes a reflector and a lens disposed in front of the reflector. The light source is mounted in the compartment and is disposed on an optical axis. The light shielding plate is mounted in the housing between the light source and the lens. The light guiding plate is mounted in the housing and is disposed below the optical axis. A first portion of light beams emitted upwardly by the light source is reflected by the reflector, passes over the light shielding plate, and further passes through the lens, which refracts the first portion of the light beams to form a first illuminating pattern. A second portion of the light beams emitted by the light source passes through the light guiding plate and further passes through the lens, which refracts the second portion of the light beams to result in a second illuminating pattern that is directed forwardly and upwardly.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring toFIGS. 4,5, and6, the preferred embodiment of a vehicle headlight assembly according to the present invention includes a housing1, a light source2, a heat-insulation plate3, an elongated light shielding plate4, and a light guiding plate5. The housing1defines a compartment10, and includes a reflector11and a lens13that is coupled to a lens holder12and that is disposed in front of the reflector11. The light source2is mounted in the compartment10via mounting unit14, and is disposed on an optical axis (L). The heat-insulation plate3is mounted in the housing1and is disposed below the light source2. The light shielding plate4is mounted in the housing1between the light source2and the lens13and has opposite ends respectively fastened to the reflector11. The light shielding plate4also has a top edge that is disposed at a same level as the optical axis (L). The light guiding plate5is mounted in the housing1and is disposed below the optical axis (L).

As shown inFIG. 6, a first portion of the light beams emitted upwardly by the light source2is reflected by the reflector11, passes over the light shielding plate4, and further passes through the lens13, which refracts the first portion of the light beams to form a first illuminating pattern that is positioned below the optical axis (L). The first illuminating pattern is a low-beam illuminating pattern. On the other hand, a second portion of the light beams emitted by the light source2passes through the light guiding plate5and further passes through the lens13, which refracts the second portion of the light beams to result in a second illuminating pattern (B) that is directed forwardly and upwardly. The light guiding plate5has a light incident surface51that faces toward the light source2and whereat the second portion of the light beams is incident, and a light exit surface52that is opposite to and spaced apart from the light incident surface51and that faces toward the lens13.

In this embodiment, the heat-insulation plate3has upper and lower surfaces and a through-hole31formed through the upper and lower surfaces. The through-hole31allows the second portion of the light beams emitted by the light source2to pass therethrough and subsequently enter the light guiding plate5. The light incident surface51is formed with saw-teeth protrusions, whereas the light exit surface52is formed with rounded protrusions. The light guiding plate5extends forwardly to the lens13with respect to the heat-insulation plate3. In the preferred embodiment, the light guiding plate5is fastened to the heat-insulation plate3and is made of a plastic material but should not be limited thereto.

As shown inFIG. 5, the reflector11has inner and outer surfaces and is formed with a groove111that extends along a curve and that is indented from the inner surface toward the outer surface. The heat-insulation plate3is constructed to match the inner surface of the reflector11. The heat-insulation plate3engages the groove111and is fixed to the reflector11by fasteners112. The heat insulation plate3is utilized in the present invention to insulate heat radiated from the light source2. It should be noted that the heat-insulation plate3can be omitted in other embodiments of the present invention.

In the conventional Poly-Ellipsoid System (PES)/headlight assembly, a portion of the descending light beams emitted by the light source62is blocked and is not utilized. However, in the present invention, due to the light guiding property of the light guiding plate5, such descending light beams can be utilized for further illumination. That is, the light guiding plate5directs the descending light beams that were previously unusable into usable light beams for forming the second illuminating pattern. With this structure of the present invention, the light beams are effectively utilized so that the illuminating efficiency of the headlight assembly is thus maximized.

It should be noted that while the preferred embodiment of the headlight assembly is exemplified as a low beam light module, this invention can also be applied to other headlight assemblies, such as a high beam light module or an integrated low/high beam light module.