The disclosed embodiments relate generally to the field of lighting devices. More specifically, the disclosed embodiments relate to light modulation systems for a vehicle headlamp.
Systems to control light exiting a vehicular lamp are known in the art. U.S. Pat. No. 10,655,819 to Na et al. discloses a vehicular lamp comprising a shield for blocking at least a portion of the light. U.S. Pat. No. 11,035,537 to Puech et al. discloses a luminous lighting module for an automotive vehicle which may form a cut-off beam.
This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Other aspects and advantages of the invention will be apparent from the following detailed description of the embodiments and the accompanying drawing figures.
In an embodiment, a light modulation system configured to modulate light exiting a vehicular headlamp is provided. The system includes a light source, a reflector, a projector shield, and an outer lens. The reflector may be configured to reflect light from the light source in a specific direction. The projector shield includes a black metalized portion, which may be configured to form a cutoff light in the light projection. The projector shield includes a transparent optic protruding from the projector shield into the light projection. The transparent optic may redirect a portion of the light projection. The outer lens may be configured to invert the light after passing the projector shield.
In an embodiment, a projector shield for a vehicular headlamp is provided. The projector shield may include a black metalized portion and a clear metalized portion. The black metalized portion may be configured to block a portion of projected light. The clear metalized portion may be coupled to the black metalized portion. The projector shield may also include a clear obelisk optic, which may be coupled to the clear metalized portion. The clear obelisk optic may include a base protruding from the clear metalized portion. The clear obelisk optic may also include a tip protruding from the base. The based may be configured to allow a first portion of light to pass therethrough for projecting from the headlamp. The tip may be configured to refract a second portion of light for preventing the second portion of light from exiting the vehicular headlamp.
In an embodiment, a clear obelisk optic is provided. The clear obelisk optic may be a transparent optic extending from a projector shield of a headlamp. The transparent optic may include a tip portion and a base portion. The tip portion may have four sides angled inwardly. The base portion may be configured to support the tip portion. The tip portion and the base portion together may form an obelisk shape. The tip portion may be configured to redirect a first portion of light for preventing the first portion of light from exiting the headlamp. The base portion may be configured to allow a second portion of light to pass therethrough for projecting from the headlamp.
Illustrative embodiments are described in detail below with reference to the attached drawing figures, which are incorporated by reference herein and wherein:
The drawing figures do not limit the invention to the specific embodiments disclosed and described herein. The drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the invention.
The following detailed description references the accompanying drawings that illustrate specific embodiments in which the invention can be practiced. The embodiments are intended to describe aspects of the invention in sufficient detail to enable those skilled in the art to practice the invention. Other embodiments can be utilized and changes can be made without departing from the scope of the invention. The following detailed description is, therefore, not to be taken in a limiting sense. The scope of the invention is defined only by the appended claims, along with the full scope of equivalents to which such claims are entitled.
In this description, references to “one embodiment”, “an embodiment”, or “embodiments” mean that the feature or features being referred to are included in at least one embodiment of the technology. Separate references to “one embodiment,” “an embodiment,” or “embodiments” in this description do not necessarily refer to the same embodiment and are also not mutually exclusive unless so stated and/or except as will be readily apparent to those skilled in the art from the description. For example, a feature, structure, act, etc. described in one embodiment may also be included in other embodiments, but is not necessarily included. Thus, the technology can include a variety of combinations and/or integrations of the embodiments described herein.
Vehicle headlamps project a light pattern to meet lighting performance objectives, including a range and an intensity of the light pattern. To avoid glare to an oncoming driver, light modulation systems including a fully opaque shield or a reflective shield (e.g., projector shield) are provided in the headlamp assembly to block a portion of light projected from the projector. The projector shield is configured to block light below a predetermined cutoff angle. The cutoff provides a light pattern in front of the vehicle that is projected downwardly towards the road. For example, the projector shield may be configured to provide a crisp cutoff at a zero degree up/down angle that extends directly in front of the vehicle (e.g., towards the horizon), such that the light pattern is restricted to downward angles below the cutoff. In addition, a specific point in the light pattern below the cutoff has a maximum intensity requirement to avoid glare to an oncoming driver. The specific point is mandated by the U.S. Department of Transportation, National Highway Traffic Safety Administration, and is known as the “legal test point”. The legal test point is located at 0.86 degrees down from the cutoff and 3.5 degrees left of center (0.86 D, 3.5 L). To achieve dimming of light below the maximum intensity requirement at the legal test point, traditional projector shields include a fully opaque protrusion corresponding to 0.86 D, 3.5 L. However, this design blocks a larger portion of light than what is necessary at the legal test point, making it difficult to provide sufficient intensity of light in areas around the legal test point. For example, the traditional shield protrusion blocks light between the legal test point and the cutoff, which creates a larger hole in the projected pattern of light than what is required.
Embodiments of the present disclosure provide a light modulation system that more accurately dims light at the legal test point without blocking light in neighboring regions of the light pattern. Rather than using an opaque projector shield protrusion, a transparent optic is used. The transparent optic is shaped like an obelisk and configured to selectively redirect light to provide a fuller light pattern without sacrificing greater reach of the pattern and while maintaining the legal test point requirement.
In certain embodiments, clear obelisk optic 100 is formed as part of the clear plastic part during the injection molding process, then protected during the metallic coating step such that it remains uncoated and fully transparent. In this way, projector shield 200 is formed as a single monolithic piece. Alternatively, clear obelisk optic 100 may be a separate part made of any optically clear material such as glass or an optically clear plastic. In these embodiments, both the black metalized portion 110 and the clear metalized portion 120 are made of black plastic (e.g., in one shot) since the clear portion is no longer necessary to produce the clear obelisk optic 100. The separate clear obelisk optic 100 may be attached to projector shield 200 using screw stakes, heat stakes, or an adhesive, for example.
Clear obelisk optic 100 protrudes from projector shield 200, such that an upper portion of clear obelisk optic 100 extends above black metalized portion 110. In some embodiments, clear obelisk optic 100 is a transparent optic protruding from the projector shield into the light projection. In this manner, a portion of light passing above black metalized portion 110 is redirected by at least a portion of clear obelisk optic 100, as further described below in connection with
Base 106 is a bottom portion of clear obelisk optic 100 configured to support tip 104. The four sides of base 106 may be vertical, or nearly vertical and having a slight inward angle towards one another. Base 106 is configured to partially protrude upwardly above a clear surface 108. Clear surface 108 is configured to be substantially parallel with a top surface of projector shield 200 (see
A second light path 132 enters clear obelisk optic 100 at tip 104 through entry side 104A and is refracted downwards into base 106 at such an angle that the light passes through the distal side 106C of base 106. For example, the downward angle of second light path 132 through clear obelisk optic 100 is less than that of first light path 131 due to the angles at which the light paths reach the entry side 104A. Upon exiting clear obelisk optic 100, second light path 132 is directed downwardly such that it misses an outer lens 660 and is instead absorbed by a lens holder 662 (see
A third light path 133 enters clear obelisk optic 100 at base 106 and is only marginally refracted such that third light path 133 enters the base 106 on a proximal side 106A and exits on the distal side 106C at an angle that deviates only slightly from the entry angle. Therefore, third light path 133 reaches the outer lens and is projected from the vehicle headlamp. In this manner, light that enters tip 104 is effectively prevented from exiting the vehicle headlamp, while light that enters base 106 effectively permits light to be projected from the vehicle headlamp. Thus, clear obelisk optic 100 may be used to substantially dim light at the legal test point via tip 104, and to substantially illuminate regions outside of the legal test point, in particular the region between the cutoff and the legal test point. In other words, the result of using clear obelisk optic 100 in projector shield 200 is a small spot of reduced light intensity in the projected light pattern, as illustrated in
It is contemplated that clear obelisk optic 100 may be a transparent optic. Transparent optic may similarly include a base portion and a tip portion that do not form a substantially obelisk shape, but any other shape which may similarly refract light bidirectionally. For example, transparent optic may be elliptically shaped, including a base portion configured to allow the passage of light therethrough and a tip portion configured to refract light, such that the refracted light does not exit the vehicular headlamp. In another example, transparent optic may be pyramidally shaped, including a base portion configured to allow the passage of light therethrough and a tip portion configured to refract light, such that the refracted light does not exit the vehicular headlamp. It is contemplated that the transparent optic may comprise any shape which includes a base portion and a tip portion, said base portion and tip portion configured to alternatively refract light to modulate the light projection from a vehicular headlamp.
The A, B, and C regions illustrated in
Illuminating region B with a relatively high light intensity (e.g., approximately 25,000 cd) compared to a relatively dim light intensity in region A (e.g., approximately 2,500 cd) is not possible using a traditional opaque shield protrusion, which substantially dims light in region B similar to that of region A. Minor light leak/bleed allows enough light to reach region A for meeting minimum requirements set by Federal Motor Vehicle Safety Standards (FMVSS).
A light source 670 provides light for projecting from vehicle headlamp 600. Light source 670 is, for example, a light-emitting diode (LED) or an array of LEDs electrically coupled with a printed circuit board 672. A heat pipe 684 is thermally coupled with light source 670 for removing heat produced by light source 670. A heat sink 680 is thermally coupled with heat pipe 684 for dispersing heat to the surrounding environment. For example, heat sink 680 may include a series of fins for transferring heat to ambient air via convection.
Light from light source 670 is directed upwards towards a reflector 650, which reflects the light towards outer lens 660. Lens holder 662 holds lens 660 in place and is black to absorb any stray light. Black metalized portion 110 blocks a lower portion of light reflected off of reflector 650. Clear obelisk optic 100 protrudes above black metalized portion 110 to redirect a portion of light as explained above in connection with
An optional motor 690 enables rotation of projector shield 200 for moving it out of the light path to provide a high beam light pattern with no cutoff. It should be noted that clear obelisk optic 100 may be used in a bi-functional headlamp (e.g., providing a low beam and a high beam), such as vehicle headlamp 600, or simply with any low beam headlamp.
In contrast,
Features described above as well as those claimed below may be combined in various ways without departing from the scope hereof. The following examples illustrate some possible, non-limiting combinations:
(A1) A light modulation system is configured to modulate a light projection exiting a vehicular headlamp, the system includes a light source, a reflector configured to reflect light from the light source in a specific direction, a projector shield which includes a black metalized portion configured to form a cutoff line in the light projection, a transparent optic protruding from the projector shield into the light project, the transparent optic configured to redirect a portion of the light projection, and an outer lens configured to invert the light after passing the projector shield.
(A2) For the light modulation system denoted as (A1), the transparent optic may include a base that may be configured to allow the passage of light therethrough, and a tip that may be configured to refract light preventing a refracted light from exiting the vehicular headlamp.
(A3) For the light modulation system denoted as (A1) or (A2), the tip may include four sides angled inwardly, said sides may be configured to refract light towards the base.
(A4) For the light modulation system denoted as any of (A1) through (A3), the system may include a motor operatively connected to the projector shield, the motor may be configured to adjust a position of the projector shield therein removing the cutoff line from the light projection.
(A5) For the light modulation system denoted as any of (A1) through (A4), the transparent optic may be one of a clear plastic or a glass.
(A6) For the light modulation system denoted as any of (A1) through (A5), the transparent optic may cause a first area within the light projection to be dimmer than other areas in the light projection not affected by the transparent optic.
(A7) For the light modulation system denoted as any of (A1) through (A6), the projector shield may include a clear metalized portion aligned with the black metalized portion.
(A8) For the light modulation system denoted as any of (A1) through (A7), the clear metalized portion and the transparent optic may be formed of one piece of material and the transparent optic may be an extension of the clear metalized portion that may be configured to extend into the light projection.
(A9) For the light modulation system denoted as any of (A1) through (A8), the system may include a lens holder that mechanically couples the outer lens to the light modulation system, the lens holder may be configured to absorb the refracted light.
(A10) For the light modulation system denoted as any of (A1) through (A9), the transparent optic may cause a second area within the light projection to be substantially as bright as the other areas in the light projection, said second area may be located between the first area and the cutoff line.
(B1) A projector shield for a vehicular headlamp includes a black metalized portion configured to block a portion of projected light, a clear metalized portion coupled to the black metalized portion, and a clear obelisk optic coupled to the clear metalized portion, the clear obelisk optic includes a base protruding from the clear metalized portion, and a tip protruding from the base, the base is configured to allow a first portion of light to pass therethrough for projecting from the headlamp, and the tip is configured to refract a second portion of light for preventing the second portion of light from exiting the vehicular headlamp.
(B2) For the projector shield denoted as (B1), the clear obelisk optic may include a clear surface connected to the base opposite the tip, the clear surface may be coupled to the clear metalized portion.
(B3) For the projector shield denoted as (B1) or (B2), the clear obelisk optic may be an extension of the clear metalized portion.
(B4) For the projector shield denoted as any of (B1) through (B3), the base and the tip of the clear obelisk optic may form an obelisk shape.
(B5) For the projector shield denoted as any of (B1) through (B4), the clear obelisk optic may be one of a clear plastic or a glass.
(C1) A clear obelisk optic includes a transparent optic extending from a projector shield of a headlamp, the transparent optic includes a tip portion having four sides angled inwardly and a base portion configured to support the tip portion, the tip portion and the base portion together form an obelisk shape and the tip portion is configured to redirect a first portion of light for preventing the first portion of light from exiting the headlamp and the base portion is configured to allow a second portion of light to pass therethrough for projecting from the headlamp.
(C2) For the clear obelisk optic denoted as (C1), the four sides of the tip portion may be angled inwardly at an angle between thirty-five degrees to fifty-five degrees.
(C3) For the clear obelisk optic denoted as (C1) or (C2), the clear obelisk optic may be made of a clear plastic.
(C4) For the clear obelisk optic denoted as any of (C1) through (C3), the clear obelisk optic may be made of glass.
(C5) For the clear obelisk optic denoted as any of (C1) through (C4), the clear obelisk optic may include a clear surface coupled to a clear metalized portion of the projector shield.
Many different arrangements of the various components depicted, as well as components not shown, are possible without departing from the spirit and scope of what is claimed herein. Embodiments have been described with the intent to be illustrative rather than restrictive. Alternative embodiments will become apparent to those skilled in the art that do not depart from what is disclosed. A skilled artisan may develop alternative means of implementing the aforementioned improvements without departing from what is claimed.
It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations and are contemplated within the scope of the claims. Not all steps listed in the various figures need be carried out in the specific order described.
This application claims the benefit of U.S. Provisional Patent Application No. 63/106,207 entitled “Clear Obelisk Projector Shield” and filed on Oct. 27, 2020, which is herein incorporated by reference in its entirety.
Number | Date | Country | |
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63106207 | Oct 2020 | US |