Lighting apparatus and mobile object including the same

A lighting apparatus to be installed on a mobile object includes: a heat dissipator having a first outer surface and a second outer surface different from the first outer surface; a first light-emitting device thermally coupled to the first outer surface of the heat dissipator; a second light-emitting device thermally coupled to the second outer surface of the heat dissipator; a reflector that reflects light emitted from the first light-emitting device; a first lens that is disposed in a path of light reflected by the reflector and that transmits the light from the reflector along a predetermined lighting direction; and a second lens disposed in a path of light from the second light-emitting device.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority of Japanese Patent Application Number 2015-048388 filed on Mar. 11, 2015, Japanese Patent Application Number 2015-048642 filed on Mar. 11, 2015, Japanese Patent Application Number 2015-048735 filed on Mar. 11, 2015, and Japanese Patent Application Number 2015-048171 filed on Mar. 11, 2015, the entire content of which is hereby incorporated, by reference.

BACKGROUND

1. Technical Field

The present disclosure relates to a lighting apparatus and a mobile object including the same.

2. Description of the Related Art

Vehicles such as automobiles are equipped with lamps such as headlamps in the front. Headlamps include, a housing and a lighting apparatus attached to the housing.

This type of vehicle lighting apparatus (headlamp) includes, for example, a light-emitting device, a reflector that reflects light from the light-emitting device forward, and a projection lens that is disposed in front of the light-emitting device so as to transmit the light reflected by the reflector (for example, see Japanese Unexamined Patent Application Publication No. 2010-118203 and Japanese Unexamined Patent Application Publication No. 2008-243433).

SUMMARY

However, the conventional vehicle lamps described above form a light distribution pattern using a plurality of lamp units. Thus, there is a problem that the design freedom of the automobile decreases since a plurality of lamp units are required to be disposed in the front of the automobile.

In view of this, an object of the present disclosure is to provide a lighting apparatus which allows for an increase in design freedom of a mobile object such as an automobile, and a mobile object including the lighting apparatus.

In order to achieve the above object, a lighting apparatus according to an aspect of the present disclosure is a lighting apparatus to be installed on a mobile object, and includes: a heat dissipator having a first outer surface and a second outer surface different from the first outer surface; a first light-emitting device thermally coupled to the first outer surface of the heat dissipator; a second light-emitting device thermally coupled to the second outer surface of the heat dissipator; a reflector that reflects light emitted from the first light-emitting device; a first lens that is disposed in a path of light reflected by the reflector and that transmits the light from the reflector along a predetermined lighting direction; and a second lens disposed in a path of light from the second light-emitting device.

Moreover, a mobile object according to one aspect of the present disclosure includes the above described lighting apparatus installed in the front portion.

According the present disclosure, it is possible to provide a lighting apparatus which allows for an increase in design freedom of a mobile object, and a mobile object including the lighting apparatus.

DETAILED DESCRIPTION OF EMBODIMENT(S)

The following describes a lighting apparatus and mobile object according to embodiments of the present disclosure with reference to the drawings. Note that the each embodiment described below shows a specific example of the present disclosure. The numerical values, shapes, materials, elements, the arrangement and connection of the elements, and others indicated in the following embodiments are mere examples, and therefore do not intend to limit the inventive concept. Therefore, among the elements in the following embodiments, those not recited in any of the independent claims defining the most generic part of the inventive concept are described as arbitrary elements.

As described herein, “front” and “forward” refer to the direction in which light is emitted from the lighting apparatus (i.e., the light-emitting direction) and the light-extraction direction in which light is extracted (i.e., the lighting direction), and “back” and “rearward” refer to the direction opposite the direction to which “front” and “forward” refer. Moreover, “front” and “forward” refer to the direction of travel when the automobile moves forward, “right” and “left” are from the perspective of the driver of the automobile when facing forward, “up” refers to the direction toward the ceiling of the automobile, and “down” and “downward” refer to the direction opposite the direction to which “up” refers.

The Z axis corresponds to the front and back directions, the Y axis corresponds to the up and down (vertical) directions, and the X axis corresponds to the left and right (horizontal, lateral) directions. In other words, in the following embodiments, the predetermined lighting direction refers to the direction in which the lighting apparatus projects light, i.e., “forward”, i.e., the positive direction of the Z axis.

Note that the drawings are represented schematically and are not necessarily precise illustrations. Additionally, like elements share like reference numbers in the drawings. Also note that the term “approximately”, such as in “approximately the same”, is used throughout the specification. Here, in addition to meaning exactly the same, “approximately the same” means, for example, essentially the same, i.e., includes deviations of about a few percent. This applies to other phrases where “approximately” is used as well.

Automobile

First, automobile100according to Embodiment 1 of the present disclosure will be described with reference toFIG. 1.FIG. 1is a front view of automobile100according to Embodiment 1.

As illustrated inFIG. 1, automobile100according to Embodiment 1 is one example of a mobile object, such as a four-wheeled automobile, and includes vehicle body (vehicle)110, and headlamps120disposed on the left and right sides of the front of vehicle body110. Automobile100is, for example, an automobile propelled by a gasoline engine or an automobile propelled by an electric motor.

Headlamps120are lamps, and in Embodiment 1, are headlights installed on a vehicle (i.e., vehicle headlamps). Each headlamp120includes housing121, front cover122, and lighting apparatus1attached behind front cover122.

Housing121is, for example, a metal housing, and includes an opening through which light from lighting apparatus1is emitted. Front cover122is a light-transmissive headlamp cover and is disposed at the opening of housing121. Housing121and front cover122are sealed together so water or dust, for example, does not enter housing121.

Lighting apparatus1is disposed behind front cover122and attached to housing121. Light emitted by lighting apparatus1passes through front cover122and out of lighting apparatus1.

Lighting Apparatus

Next, lighting apparatus1according to Embodiment 1 will be described with reference toFIG. 2throughFIG. 4.

FIG. 2is a front view of lighting apparatus1according to Embodiment 1.FIG. 3is a cross sectional view of lighting apparatus1according to Embodiment 1, taken along line III-III inFIG. 2.FIG. 4is a cross sectional view of lighting apparatus1according to Embodiment 1, taken along line III-III inFIG. 2, illustrating light paths of light emitted by low beam light-emitting device11. More specifically,FIG. 3andFIG. 4are vertical cross sections taken down the center of lighting apparatus1.

Note that inFIG. 3andFIG. 4, the dotted and dashed horizontal line represents central axis J of low beam lens30. Central axis J is approximately aligned with the optical axis of low beam lens30, and passes through the approximate center of lighting apparatus1.

Lighting apparatus1according to Embodiment 1 is installed on a mobile object. Lighting apparatus1is, for example, a vehicle lighting apparatus used in a vehicle headlamp, and emits light forward. In other words, “forward.” relative to the vehicle is equivalent to the light-emitting direction of lighting apparatus1, and equivalent to the lighting direction of lighting apparatus1. As illustrated inFIG. 1, lighting apparatuses1are disposed in the front of vehicle body110.

As illustrated inFIG. 2andFIG. 3, lighting apparatus1includes, as the main body of the lamp, low beam light source module10, high beam light source module20, low beam lens30, high beam lens40, heat dissipator50, reflector60, and shield70. Although not illustrated in the Drawings, lighting apparatus1further includes a lighting controller that controls low beam light source module10and high beam light source module20.

Lighting apparatus1is an integrated tamp capable of emitting a high beam, which is a driving beam, and a low beam, which is a passing beam. Note that the high beam illuminates an area far ahead of automobile100, and the low beam illuminates an area forward and downward of automobile100.

As illustrated inFIG. 2, lighting apparatus1is configured to fit within a predetermined circular region when viewed from the lighting direction when viewed along the Z axis). More specifically, low beam light source module10, high beam light source module20, low beam lens30, high beam lens40, heat dissipator50, reflector60, and shield70form a unit that fits within a predetermined circular region when viewed along the Z axis. The predetermined circular region is, for example,70 mm (in diameter).

Note that lighting apparatus1according to Embodiment 1 is installed on automobile100configured for roads where the driving lane (i.e., the lane in which the driver drives his or her own vehicle) is the right lane and the oncoming traffic lane is the left lane relative to the direction of travel, such as in the United States of America. When lighting apparatus1is to be installed on an automobile configured for roads where the driving lane is the left lane and the oncoming traffic lane is the right lane relative to the direction of travel, such as in Japan, the configuration described below may be reversed left and right about central axis J of lighting apparatus1.

Hereinafter, each element of lighting apparatus1will be described in detail.

Low Beam Light Source Module

Low beam light source module10is one example of a first light source that emits light for short-distance illumination. More specifically, low beam light source module10is a light-emitting diode (LED) module for generating a low beam and is turned on when an area forward and downward of vehicle body110is to be illuminated—that is, more specifically, when the road surface is to be illuminated.

Low beam light source module10is turned on when the surrounding environment is dark, such as at night or in a tunnel. In Embodiment 1, low beam light source module10turns on when the high beam is to be emitted (for long-distance illumination) in addition to when just the low beam is to be emitted (for short-distance illumination). In other words, in Embodiment 1, the high beam is formed of the light emitted by low beam light source module10and the light emitted by high beam light source module20.

Low beam light source module10is a white light source and is, for example, a B-Y type white LED light source, which emits white light using a blue LED chip that emits blue light and a yellow phosphor. Alternatively, low beam light source module10may be a white LED light source that emits white light using LED chips emitting blue, red, and green light.

Low beam light source module10may be a surface mount device (SMD) module, and may be a chip on board (COB) module.

When low beam light source module10is an SMD module, low beam light-emitting device11is an SMD LED device that has an LED chip (bare chip) mounted and sealed with a sealant (phosphor-containing resin) in a resin package. When low beam light source module10is a COB module, low beam light-emitting device11is an LED chip (bare chip) itself, and is directly mounted on substrate12. In this case, the LED chip mounted on substrate12is sealed with a sealant such as a phosphor-containing resin.

Low beam light source module10is fixed to heat dissipator50. More specifically, as illustrated inFIG. 3, substrate12is placed on and fixed to a predetermined placement surface51of heat dissipator50. In Embodiment 1, substrate12is disposed lying down (i.e., disposed horizontally) so low beam light source module10emits light upward. In other words, the optical axis of low beam light source module10(low beam light-emitting device11) is parallel to the Y axis.

Low beam light-emitting device11is one example of a first light-emitting device that emits light that is to pass through low beam lens30. Low beam light-emitting device11is disposed at a focal point of reflector60(disposed at a first focal point). Low beam light-emitting device11is positioned below central axis J of low beam lens30. Low beam light-emitting device11is thermally coupled to placement surface51of heat dissipator50.

Substrate12is, for example, a ceramic substrate including, for example, alumina, a resin substrate including resin, or an insulated metal substrate including a metal base covered by a layer of insulating material. Substrate12has a shape in a plan view corresponding to the shape of placement surface51of heat dissipator50on which substrate12is placed.

High Beam Light Source Module

High beam light source module20is one example of a second light source that emits light for long-distance illumination. More specifically, high beam light source module20is an LED module for generating a high beam and is turned on when an area far ahead of vehicle body110(including areas above the horizon plane) is to be illuminated.

High beam light source module20is turned on when the surrounding environment is dark, such as at night or in a tunnel, and there are no oncoming vehicles in the oncoming traffic lane. More specifically, high beam light source module20is turned on when the high beam is to be emitted.

High beam light source module20is a white light source and is, for example, a B-Y type white LED light source, which emits white light using a blue LED chip that emits blue light and a yellow phosphor. Alternatively, high beam light source module20may be a white LED light source that emits white light using LED chips emitting blue, red, and green light.

High beam light source module20may be an SMD module and, alternatively, may be a COB module. Details regarding the structures of SMD and COB modules are the same as described with respect to low beam light source module10.

High beam light source module20is fixed to heat dissipator50. More specifically, as illustrated inFIG. 3, substrate24is placed on and fixed to a predetermined placement surface52of heat dissipator50. In Embodiment 1, substrate24is disposed standing up (i.e., disposed vertically) so high beam light source module20emits light forward. In other words, the optical axis of high beam light source module20(high beam light-emitting devices21through23) is parallel to the Z axis.

In this way, high beam light source module20and low beam light source module10are fixed to the same heat dissipator50. More specifically, high beam light source module20and low beam light source module10are placed on and fixed to different placement surfaces on heat dissipator50.

High beam light-emitting devices21through23are each one example of a second light-emitting device that emits light that is to pass through high beam lens40. High beam light-emitting devices21through23may emit the same color and amount of light and, alternatively, may emit different colors and amounts of light from one another.

High beam light-emitting devices21through23are disposed farther in the lighting direction than low beam light-emitting device11. In other words, high beam light-emitting devices21through23are more forwardly disposed than low beam light-emitting device11(i.e., farther in the positive direction of the Z axis). High beam light-emitting devices21through23are, for example, positioned below central axis J of low beam lens30and below low beam light-emitting device11. High beam light-emitting devices21through23are thermally coupled to heat dissipator50.

High beam light-emitting device21emits light that is to pass through collimating lens41of high beam lens40. High beam light-emitting device22emits light that is to pass through collimating lens42of high beam lens40. High beam light-emitting device23emits light that is to pass through collimating lens43of high beam lens40. Light emitted through collimating lenses41through43may illuminate the same area and, alternatively, may illuminate different areas.

Substrate24is, for example, a ceramic substrate including, for example, alumina, a resin substrate including resin, or an insulated metal substrate including a metal base covered by a layer of insulating material. Substrate24has a shape in a plan view corresponding to the shape of placement surface52of heat dissipator50on which substrate24is placed. For example, as illustrated inFIG. 2, the plan view shape of substrate24is an approximate circular arc having a predetermined width.

Low Beam Lens

Low beam lens30is one example of a first lens that is disposed in a path of light reflected by reflector60and that transmits the light from reflector60along a predetermined lighting direction. More specifically, low beam lens30is a projection lens that transmits in a forward direction light emitted by low beam light source module10.

As illustrated by the bold solid lines inFIG. 4, light emitted by low beam light source module10enters low beam lens30through the entry surface of low beam lens30after reflecting off reflector60, and exits low beam lens30through the exit surface of low beam lens30. Note that the entry surface is the back planar surface of low beam lens30, and the exit surface is the front curved surface (for example, a spherical or oval spherical surface) of low beam lens30.

In Embodiment 1, low beam lens30is more forwardly disposed than low beam light source module10and shield70(i.e., disposed farther in the positive direction of the Z axis). Low beam lens30is also more forwardly disposed than high beam lens40. More specifically, low beam lens30is disposed such that the entry surface of low beam lens30and the exit surface (front principal surface) of high beam lens40are approximately flush with one another. Low beam lens30is disposed to overlap with shield70and reflector60in a front view. Positioning of low beam lens30is achieved by, for example, low beam lens30being fixed to heat dissipator50.

Low beam lens30can be manufactured by, for example, injection molding using a light-transmissive resin such as amyl (PMMA), polycarbonate (PC), or a cyclic olefin resin. For example, low beam lens30is a portion of a sphere or oval sphere. More specifically, the upper portion of low beam lens30has the shape of a quarter slice of a sphere (one quarter of a sphere), and the lower portion has the shape of one quarter of a sphere with portions in front of high beam lens40(the three collimating lenses41through43) removed.

High Beam Lens

High beam lens40is a projection lens that transmits light emitted by high beam light source module20. High beam lens40is one example of a second lens disposed in a path of light from high beam light-emitting devices21through23.

More specifically, high beam lens40is formed by grouping three collimating lenses41through43together. Each of the three collimating lenses41through43corresponds to one of high beam light-emitting devices21through23. The three collimating lenses41through43convert incident light into collimated light.

Each of the three collimating lenses41through43has a truncated cone shape having a diameter that widens toward the front. High beam light-emitting devices21through23are disposed to the small diameter side of the three collimating lenses41through43.

High beam lens40can be manufactured by, for example, injection molding using a light-transmissive resin such as acryl (PMMA), polycarbonate (PC), or a cyclic olefin resin.

As illustrated inFIG. 3, high beam lens40and high beam light source module20are disposed on the same side of central axis J of low beam lens30as low beam light source module10. More specifically, low beam light source module10, high beam light source module20, and high beam lens40are disposed below central axis J of low beam lens30.

Moreover, high beam lens40and high beam light source module20are more forwardly disposed than shield70. More specifically, high beam lens40and high beam light source module20are, in a side view, disposed between shield70and low beam lens30.

Heat dissipator50is a heat dissipating component for dissipating and releasing out (to the atmosphere) heat generated by low beam light source module10and high beam light source module20. As such, heat dissipator50includes, for example, a material with a high rate of heat transfer, such as metal. Heat dissipator50is, for example, an aluminum die cast heat dissipator including composite aluminum. Heat dissipator50includes a plurality of heat dissipating fins.

Placement surface51is one outer surface (the first outer surface) of heat dissipator50. In Embodiment 1, placement surface51is an outer surface exposed to the central axis J side of low beam lens30, and more specifically is the top surface of heat dissipator50. Placement surface51is, for example, a planar surface parallel to central axis J.

Low beam light-emitting device11is thermally coupled to placement surface51. More specifically, low beam light source module10is placed on placement surface51. Moreover, shield70is disposed on placement surface51.

Placement surface52is one outer surface (second outer surface) of heat dissipator50, and is a different outer surface than placement surface51. In Embodiment 1, placement surface52is the front end surface of heat dissipator50. Placement surface52is, for example, a planar surface perpendicular to central axis J. Placement surface52is approximately perpendicular to placement surface51. Placement surface51and placement surface52share a common edge.

As illustrated inFIG. 3, heat dissipator50includes elongated portion53. Elongated portion53extends so as to cover the side of reflector60opposite the reflective surface of reflector60. More specifically, elongated portion53extends upward from the back end portion of heat dissipator50. The height of elongated portion53(i.e., the distance between the top surface of elongated portion53and placement surface51) is greater than the height from placement surface51to the highest point of reflector60, for example. Stated differently, elongated portion53extends above reflector60when viewed from the front.

Heat dissipator50has a lengthwise direction extending from front to back. In other words, in a side view, placement surface51corresponds to the lengthwise portion of heat dissipator50and placement surface52corresponds to the narrow portion of heat dissipator50, as illustrated inFIG. 3.

Reflector

Reflector60reflects light emitted from low beam light-emitting device11. Reflector60is disposed above low beam light source module10. The area above reflector60is, for example, open. In other words, when lighting apparatus1is viewed from above, the back surface of reflector60(i.e., the surface opposite the light reflective surface) is visible.

Reflector60includes a light reflective surface (curved reflective surface) that reflects forward light emitted upward by low beam light source module10, such that the light is incident on low beam lens30. More specifically, as illustrated inFIG. 3, reflector60includes first reflective surface61and second reflective surface62.

First reflective surface61is the principal reflective surface of reflector60. The light reflected by first reflective surface61travels toward low beam lens30, as illustrated by the bold solid lines inFIG. 4.

First reflective surface61includes, for example, a portion of a spheroid. For example, in a vertical cross section of lighting apparatus1(the cross sections illustrated inFIG. 3andFIG. 4), first reflective surface61has a shape in which a plurality of ellipses having mutually different focal points are connected. Note that one focal point of the plurality of ellipses (the first focal point of first reflective surface61) is positioned near low beam light-emitting device11. Another focal point of the plurality of ellipses (the second focal point of first reflective surface61) is positioned near a focal plane of low beam lens30. For example, an axis (a lengthwise axis) in the approximate elliptical shape of first reflective surface61extends in a line connecting low beam light-emitting device11and an edge (upper surface edge) of shield70in the focal plane of low beam lens30. This axis is slanted relative to central axis J of low beam lens30.

Second reflective surface62reflects light emitted from low beam light-emitting device11and not reflected by first reflective surface61. As illustrated by the bold broken line inFIG. 4, light reflected by second reflective surface62is then reflected by reflective film71of shield70and travels toward low beam lens30.

Reflector60is fixed to heat dissipator50such that low beam light-emitting device11is disposed near the first focal point. With this, light emitted from low beam light-emitting device11is reflected by reflector60and travels toward the vicinity of the second focal point.

Reflector60is, for example, formed by resin molding using a heat resistant resin, and a reflective film is formed on the surface of reflector60. For example, polycarbonate (PC) can be used as the high resistant resin. Alternatively, instead of a heat resistant resin, fiber reinforced plastic (FRP) or a bulk molding compound (BMC) may be used. The reflective film is, for example, a metal deposition film such as an aluminum deposition film. The reflective film specularly reflects light emitted from low beam light-emitting device11.

Shield

Shield70is one example of a shield that blocks a portion of the light reflected by reflector60. More specifically, shield70is a structure that defines a predetermined cutoff line—which is a boundary between dark and light areas—by blocking a portion of light emitted by from low beam light source module10.

As illustrated inFIG. 3, shield70is disposed on placement surface51, between reflector60and low beam lens30. Shield70is fixed to heat dissipator50. More specifically, shield70is disposed such that the upper surface end in the focal plane of low beam lens30is approximately aligned with central axis J of low beam lens30. In other words, shield70is disposed between placement surface51and central axis J of low beam lens30.

Shield70is, for example, formed using a heat resistant resin or fiber reinforced plastic, similar to reflector60. The surface of shield70nearest low beam lens30has a reflective film formed thereon. For example, as illustrated inFIG. 3, shield70includes reflective film71.

Reflective film71directs light toward low beam lens30by reflecting light reflected by second reflective surface62of reflector60. Reflective film71is, for example, a metal deposition film such as an aluminum deposition film.

Reflective film71has, for example, a curved reflective surface. As illustrated by the bold broken line inFIG. 4, the light reflected by reflective film71and subsequently transmitted by low beam lens30is widely emitted forward and in a direction pointing above the horizon line.

Note that shield70may include metal instead of resin. Shield70may also be integrally formed with heat dissipator50.

As described above, lighting apparatus1according to Embodiment 1 is to be installed on automobile100and includes: heat dissipator50having placement surface51and placement surface52different from placement surface51; low beam light-emitting device11thermally coupled to placement surface51of heat dissipator50; high beam light-emitting devices21through23thermally coupled to placement surface52of heat dissipator50; reflector60that reflects light emitted from low beam light-emitting device11; low beam lens30that is disposed in a path of light reflected by reflector60and that transmits the light from reflector60along a predetermined lighting direction; and high beam lens40disposed in a path of light from high beam light-emitting devices21through23. Moreover, for example, automobile100according to Embodiment 1 includes lighting apparatus1installed in the front portion of vehicle body110.

With this configuration, low beam light-emitting device11and high beam light-emitting devices21through23are disposed on a single heat dissipator50. In other words, lighting apparatus1according to Embodiment 1 is a lamp that is a single unit that can emit a low beam and a high beam. Therefore, compared to when separate lamps for low beam use and high beam use are required, the design freedom of automobile100can be greatly increased.

Moreover, for example, lighting apparatus1further includes shield70that is disposed on placement surface51, between reflector60and low beam lens30, and blocks a portion of the light reflected by reflector60.

With this configuration, for example, light traveling toward the oncoming traffic lane can be blocked by shield70, which makes it possible to reduce glare for oncoming traffic.

Moreover, for example, high beam light-emitting devices21through23and high beam lens40are disposed on the same side of central axis J of low beam lens30as low beam light-emitting device11.

With this configuration, for example, low beam light-emitting device11and high beam light-emitting devices21through23can be closely disposed, which makes it possible to achieve a compact heat dissipator50. This in turn makes it possible to achieve a compact lighting apparatus1.

Moreover, for example, heat dissipator50extends to cover the side of reflector60opposite the reflective surface of reflector60.

With this configuration, the cubic measure of heat dissipator50can be increased, which makes it possible to effectively dissipate heat. Moreover, as a result of heat dissipator50including elongated portion53, the center of mass of lighting apparatus1can be moved farther rearward compared to when elongated portion53is not included. Thus, for example, it possible to stabilize lighting apparatus1by fixing lighting apparatus1to vehicle body110at a forward portion of lighting apparatus1.

Moreover, for example, heat dissipator50, low beam light-emitting device11, high beam light-emitting devices21through23, reflector60, low beam lens30, and high beam lens40form a unit that fits within a predetermined circular region when viewed from the lighting direction.

With this configuration, low beam light-emitting device11, low beam lens30, high beam light-emitting devices21through23, and high beam lens40can be formed as a unit, which makes it possible to achieve a compact lighting apparatus1.

With this configuration, power consumption can be reduced as a result of using LEDs.

Next, the lighting apparatus according to Embodiment 2 will described.

The conventional lighting apparatus described in the background section includes a protrusion acting as a shield that blocks a portion of the light reflected from a reflector in order to reduce glare for the oncoming traffic lane. As a result, a portion of the light emitted by the light-emitting device is blocked by the protrusion acting as a shield and not emitted forward. In other words, with the conventional lighting apparatus, light emitted by the light-emitting device cannot be effectively used for illumination purposes, and thus has a low lighting efficiency.

In view of this, a first object of the present disclosure is to provide a lighting apparatus which can achieve a further increase in lighting efficiency and a mobile object including the lighting apparatus.

In order to achieve the above described first object, a lighting apparatus according to Embodiment 2 is a lighting apparatus to be installed on a mobile object, and includes: a light-emitting device, a reflector that reflects light emitted from the light-emitting device; a lens disposed in a path of light reflected by the reflector; and a light guiding component disposed between the reflector and the lens. The light guiding component changes a traveling direction of the light from the reflector to guide the light to the lens.

According to Embodiment 2, lighting efficiency can be further increased.

The conventional lighting apparatus described in the background section reflects light emitted from the light-emitting device at the front end portion (the portion toward the lens) of the reflector in order to emit light for illuminating an upward area in front of the vehicle. As such, the reflector includes a large reflective surface for reflecting a greater portion of the light emitted from the light-emitting device. In other words, since the size of the reflector is increased, the size of the structure for supporting the reflector is also increased, thereby increasing the overall size of the lighting apparatus.

In view of this, a second object of the present disclosure is to provide a compact lighting apparatus and a mobile object including the lighting apparatus.

In order to achieve the above described second object, a lighting apparatus according to Embodiment 2 is a lighting apparatus to be installed on a mobile object and includes: a first light-emitting device; a first heat dissipator thermally coupled to the first light-emitting device; a first reflector that reflects light emitted from the first light-emitting device; a lens that is disposed in a path of light reflected by the first reflector and that transmits the light from the first reflector along a predetermined lighting direction; a second light-emitting device disposed further in the lighting direction than the first light-emitting device; and a second heat dissipator thermally coupled to the second light-emitting device and disposed so that the first reflector is between the first heat dissipator and the second heat dissipator. The second heat dissipator includes: an extension portion extending along the lighting direction beyond the first reflector; and reflective portion that is fixed to the extension portion and reflects light emitted from the first light-emitting device and not reflected by the first reflector.

According to Embodiment 2, it is possible to provide a compact lighting apparatus and an automobile including the lighting apparatus.

Lighting Apparatus

Next, lighting apparatus1A according to Embodiment 2 will be described with reference toFIG. 5throughFIG. 9.

FIG. 5is a front view of lighting apparatus1A according to Embodiment 2.FIG. 6is a cross sectional view of lighting apparatus1A according to Embodiment 2, taken along line VI-VI inFIG. 5. More specifically,FIG. 6is vertical cross section taken down the center of lighting apparatus1A.

FIG. 7is a cross sectional view of lighting apparatus1A according to Embodiment 2, taken along line VI-VI inFIG. 5, and illustrating paths of light passing through protrusion80A.FIG. 8is a cross sectional view of lighting apparatus1A according to Embodiment 2, taken along line VII-VII inFIG. 5, and illustrating paths of light passing through protrusion80A.FIG. 9is a cross sectional view of lighting apparatus1A according to Embodiment 2, taken along line VI-VI inFIG. 5, and illustrating paths of light reflected by reflective portion54A.

Note that inFIG. 7andFIG. 8, the bold solid line arrows indicate the paths of light passing through protrusion80A according to Embodiment 2. The thin broken line arrows are provided as a comparative example of paths of light when protrusion80A according to Embodiment 2 is not provided. Moreover, inFIG. 8, the vertically drawn dotted and dashed line is central axis J of low beam lens30A. Central axis J passes through the approximate center of lighting apparatus1A.

Similar to lighting apparatus1according to Embodiment 1, lighting apparatus1A according to Embodiment 2 is installed on a mobile object. Lighting apparatus1A is, for example, attached to automobile100illustrated inFIG. 1. In other words, automobile100may include, in the front of vehicle body110, lighting apparatus1A according to Embodiment 2 instead of lighting apparatus1according to Embodiment 1.

As illustrated inFIG. 5andFIG. 6, lighting apparatus1A includes, as the main body of the lamp, low beam light source module10A, high beam light source module20A, low beam lens30A, high beam lens40A, heat dissipator50A, reflector60A, shield70A, and protrusion80A. Although not illustrated in the Drawings, lighting apparatus1A further includes a lighting controller that controls low beam light source module10A and high beam light source module20A.

As illustrated inFIG. 5, lighting apparatus1A is configured to fit within a predetermined circular region when viewed from the lighting direction (i.e., when viewed along the Z axis). More specifically, low beam light source module10A, high beam light source module20A, low beam lens30A, high beam lens40A, heat dissipator50A, reflector60A, shield70A, and protrusion80A form a unit that fits within a predetermined circular region when viewed along the Z axis. The predetermined circular region is, for example,70 mm (in diameter).

Hereinafter, each element of lighting apparatus1A will be described in detail. Note that description of configurations that are the same as in Embodiment 1 are omitted or condensed.

Low Beam Light Source Module

Similar to low beam light source module10according to Embodiment 1, low beam light source module10A is one example of a first light source that emits light for short-distance illumination. As illustrated inFIG. 6, low beam light source module10A is fixed to first heat sink51A of heat dissipator50A. In other words, low beam light source module10A is different from Embodiment 1 in regard to arrangement, and the same as low beam light source module10in regard to structure, for example.

More specifically, substrate12is placed on and fixed to a predetermined placement surface of first heat sink51A. In Embodiment 2, substrate12is disposed lying down (i.e., disposed horizontally) so low beam light source module10A emits light upward, as illustrated inFIG. 6. In other words, the optical axis of low beam light source module10A (low beam light-emitting device11) is parallel to the Y axis.

In Embodiment 2, low beam light-emitting device11is thermally coupled to first heat sink51A. Substrate12has a shape in a plan view corresponding to the shape of placement surface of first heat sink51A on which substrate12is placed.

High Beam Light Source Module

Similar to high beam light source module20according to Embodiment 1, high beam light source module20A is one example of a second light source that emits light for long-distance illumination. As illustrated inFIG. 6, high beam light source module20A is fixed to second heat sink52A of heat dissipator50A. In other words, high beam light source module20A is different from Embodiment 1 in regard to arrangement, and the same as high beam light source module20in regard to structure, for example.

More specifically, substrate24is placed on and fixed to a predetermined placement surface of second heat sink52A. In Embodiment 2, substrate24is disposed standing up (i.e., disposed vertically) so high beam light source module20A emits light forward, as illustrated inFIG. 6. In other words, the optical axis of high beam light source module20A (high beam light-emitting devices21through23) is parallel to the Z axis.

In Embodiment 2, high beam light-emitting devices21through23are thermally coupled to second heat sink52A. Substrate24has a shape in a plan view corresponding to the shape of placement surface of second heat sink52A on which substrate24is placed. For example, as illustrated inFIG. 5, the plan view shape of substrate24is an approximate circular arc having a predetermined width.

Low Beam Lens

Similar to low beam lens30according to Embodiment 1, low beam lens30A is one example of a first lens that is disposed in a path of light reflected by reflector60A and that transmits the light from reflector60A along a predetermined lighting direction.

In Embodiment 2, positioning of low beam lens30A is achieved by, for example, low beam lens30A being fixed to shield70A (or first heat sink51A). Moreover, in Embodiment 2, the lower portion of low beam lens30A has the shape of a quarter slice of a sphere (one quarter of a sphere), and the upper portion has the shape of one quarter of a sphere with portions in front of high beam lens40A (the three collimating lenses41through43) removed.

Low beam lens30A projects a light source image formed on focal plane F as an inverted, image on a virtual vertical screen in front of low beam lens30A. In other words, low beam lens30A inversely projects a light source image (a distribution of light) formed on focal plane F, which is light emitted by low beam light-emitting device11. Note that focal plane F is a plane including the rearward focal point of low beam lens30A, and more specifically is the focal plane on the reflector60A side of low beam lens30A. Focal plane F is, for example, located near a focal point (the second focal point) of reflector60A.

High Beam Lens

High beam lens40A is a projection lens that transmits light emitted by high beam light source module20A. Similar to high beam lens40according to Embodiment 1, high beam lens40A is one example of a second lens disposed in a path of light from high beam light-emitting devices21through23.

In Embodiment 2, high beam lens40A and high beam light source module20A are disposed on the same side of central axis J of low beam lens30A as low beam light source module10A, as illustrated inFIG. 6. More specifically, high beam lens40A and high beam light source module20A are disposed above central axis J of low beam lens30A.

Similar to heat dissipator50according to Embodiment 1, heat dissipator50A is a heat dissipating component for dissipating and releasing out (to the atmosphere) heat generated by low beam light source module10A and high beam light source module20A. As such, heat dissipator50A includes, for example, a material with a high rate of heat transfer, such as metal.

As illustrated inFIG. 6, heat dissipator50A is divided into two heat sinks—first heat sink51A and second heat sink52A. In other words, first heat sink51A and second heat sink52A are combined such that heat dissipator50A is an integral unit. First heat sink51A and second heat sink52A each include a plurality of heat dissipating fins. First heat sink51A and second heat sink52A are aluminum die cast heat sinks including composite aluminum, for example.

First heat sink51A is a first heat dissipator thermally coupled to low beam light-emitting device11. First heat sink51A is principally a heat dissipating component for dissipating heat generated by low beam light source module10A (low beam light-emitting device11). First heat sink51A includes a placement surface (installation surface) for placing low beam light source module10A.

Second heat sink52A is a second heat dissipator thermally coupled to high beam light-emitting devices21through23. Second heat sink52A is principally a heat dissipating component for dissipating heat generated by high beam light source module20A (high beam light-emitting devices21through23). Second heat sink52A includes a placement surface (installation surface) for placing high beam light source module20A.

Second heat sink52A is disposed so as to sandwich reflector60A between first heat sink51A and second heat sink52A. In Embodiment 2, a space is formed between first heat sink51A and second heat sink52A where low beam light source module10A, reflector60A, and protrusion80A are disposed, as illustrated inFIG. 6.

As illustrated inFIG. 6, second heat sink52A includes extension portion53A and reflective portion54A.

Extension portion53A is a section of second heat sink52A, and extends in the lighting direction beyond the end of reflector60A located in the lighting direction (i.e., the end located in the positive direction of the X axis). More specifically, extension portion53A is the section of second heat sink52A that is positioned in front of the front end of reflector60A. Extension portion53A is not covered by reflector60A and is exposed to low beam light source module10A. As illustrated inFIG. 6, extension portion53A is disposed directly above and covers protrusion80A and a portion of shield70A (the back portion).

The front end surface of extension portion53A is a placement surface for placing high beam light source module20A. In other words, high beam light-emitting devices21through23are thermally coupled to extension portion53A.

Reflective portion54A reflects light emitted from low beam light-emitting device11and not reflected by reflector60A. Reflective portion54A has, for example, a curved reflective surface. Light reflected by reflective portion54A travels toward reflective film71A of shield70A, as illustrated inFIG. 9. More specifically, the light reflective surface of reflective portion54A (the curved reflective surface) includes a portion of a spheroid.

Reflective portion54A is fixed to extension portion53A. In Embodiment 2, reflective portion54A is a reflective film integrally formed with extension portion53A.

For example, reflective portion54A is a reflective film formed on the bottom surface of extension portion53A (the surface on the same side as low beam light-emitting device11) by white anodizing the aluminum, white coating, or deposition of a thin metal film. In other words, reflective portion54A is, for example, a white anodized film formed on the bottom surface of extension portion53A, a white resist film coated on the bottom surface of extension portion53A, or an aluminum deposition film deposited on the bottom surface of extension portion53A. Reflective portion54A may be formed by treating the bottom surface of extension portion53A to have a specular surface.

Reflector

Reflector60A is one example of a first reflector that reflects light emitted from low beam light-emitting device11. Reflector60A is disposed in heat dissipator50A, above low beam light source module10A. Reflector60A includes a light reflective surface (curved reflective surface) that reflects diagonally forward and downward light emitted upward by low beam light source module10A, such that the light is incident on low beam lens30A.

In Embodiment 2, the light reflective surface of reflector60A (the surface that opposes low beam light-emitting device11) includes a portion of a spheroid. For example, in a vertical cross section of lighting apparatus1A (the cross sections illustrated inFIG. 6), reflector60A has a shape in which a plurality of ellipses having mutually different focal points are connected. Note that one focal point of each of the plurality of ellipses (the first focal point of reflector60A) is located near low beam light-emitting device11. Another focal point of the plurality of ellipses (the second focal point of reflector60A) is located near focal plane F of low beam lens30A. For example, an axis (a lengthwise axis) in the approximate elliptical shape of reflector60A extends in a line connecting low beam light-emitting device11and an edge (upper surface edge) of shield70A in focal plane F of low beam lens30A.

Reflector60A is fixed to first heat sink51A of heat dissipator50A such that low beam light-emitting device11is disposed near the first focal point. With this, light emitted from low beam light-emitting device11is reflected by reflector60A and travels toward the vicinity of the second focal point.

Reflector60A is, for example, formed by resin molding using a heat resistant resin, and a reflective film is formed on the surface of reflector60A. For example, polycarbonate (PC) can be used as the high resistant resin. Alternatively, instead of a heat resistant resin, fiber reinforced plastic (FRP) or a hulk molding compound (BMC) may be used. The reflective film is, for example, a metal deposition film such as an aluminum deposition film. The reflective film specularly reflects light emitted from low beam light-emitting device11.

Shield

Shield70A is one example of a shield that blocks a portion of the light reflected by reflector60A. More specifically, shield70A is a structure that defines a predetermined cutoff line—which is a boundary between dark and light areas—by blocking a portion of light emitted by low beam light source module10A.

Shield70A is disposed between reflector60A and low beam lens30A. More specifically, shield70A is fixed to first heat sink51A.

Shield70A is, for example, formed using a heat resistant resin or fiber reinforced plastic, similar to reflector60A. The surface of shield70A nearest low beam lens30A has a reflective film formed thereon. For example, as illustrated inFIG. 6, shield70A includes reflective film71A.

Reflective film71A is one example of a second reflector disposed on shield70A. Reflective film71A directs light toward low beam lens30A by reflecting light reflected by reflective portion54A. Reflective film71A is, for example, a metal deposition film such as an aluminum deposition film.

Reflective film71A has, for example, a curved reflective surface. As illustrated inFIG. 9, after passing through low beam lens30A, the light reflected by reflective film71A is widely emitted forward and in a direction pointing above the horizon line.

Note that shield70A may include metal instead of resin. Shield70A may also be integrally formed with first heat sink51A.

Protrusion80A is one example of a light guiding component disposed between reflector60A and low beam lens30A. Protrusion80A protrudes upward from the ceiling (top surface) of shield70A. More specifically, protrusion80A protrudes upward above the optical axis of low beam lens30A. Note that inFIG. 6, the axis of low beam lens30A extends in a line connecting a point where central axis J intersects the entry surface of low beam lens30A and an edge (upper surface edge) of shield70A in focal plane F of low beam lens30A.

As illustrated inFIG. 6, protrusion80A is disposed between focal surface F of low beam lens30A and reflector60A. More specifically, protrusion80A is disposed between the position of the second focal point of reflector60A and reflector60A.

As illustrated inFIG. 8, protrusion80A is disposed in a position offset from central axis J of low beam lens30A . . . . In Embodiment 2, protrusion80A is offset to the driving lane side (right side) of central axis J.

As illustrated inFIG. 7andFIG. 8, protrusion80A includes entry surface81A and exit surface82A. Protrusion80A changes the direction of travel of light reflected by reflector60A and entering through entry surface81A, and transmits the light through exit surface82A toward low beam lens30A. More specifically, protrusion80A changes the direction of travel of light entering through entry surface81A such that the light is transmitted to the driving lane side of the road. Moreover, protrusion80A changes the direction of travel of light entering through entry surface81A such that an area farther ahead is illuminated.

As illustrated inFIG. 7andFIG. 8, entry surface81A has a convex surface protruding toward reflector60A. As illustrated inFIG. 7andFIG. 8, exit surface82A has a concave surface receding toward reflector60A. Entry surface81A and exit surface82A include, for example, a portion of a spheroid.

For example, entry surface81A and exit surface82A are vertically slanted (i.e., slanted relative to the Y axis), as illustrated inFIG. 7. More specifically, entry surface81A and exit surface82A are slanted such that the top end is positioned farther forward than the bottom end (the portion connected to the ceiling shield70A). In other words, protrusion80A protrudes upward from the ceiling of shield70A and diagonally forward.

As illustrated inFIG. 8, protrusion80A includes side surface83A and side surface84A. Side surface83A and side surface84A are the side surfaces between entry surface81A and exit surface82A, and are parallel to the optical axis of low beam light-emitting device11. More specifically, side surface83A and side surface84A are planar surfaces parallel to the Y axis. In other words, side surface83A and side surface84A are disposed perpendicular to the ceiling of shield70A. For example, side surface83A and side surface84A are elliptical or circular arcs having a predetermined width.

As illustrated inFIG. 8, side surface83A and side surface84A are slanted relative to central axis J. More specifically, side surface83A and side surface84A are slanted such that the distal end (the end where entry surface81A is located) is distanced farther from central axis J than the proximal end (the end where exit surface82A is located).

Protrusion80A includes a light-transmissive resin material. In Embodiment 2, protrusion80A is integrally formed with shield70A. Thus, protrusion80A and shield70A include the same material, such as a heat resistant resin or fiber resistant plastic.

Note that, as described above, although shield70A has a reflective film formed on the surface, a reflective film is not formed on protrusion80A. More specifically, a reflective film is not formed on entry surface81A, and a reflective film is not formed on exit surface82A.

Light Passing Through Protrusion

Next, paths of light passing through protrusion80A according to Embodiment 2 will be described with reference toFIG. 7andFIG. 8.

Light emitted upward by low beam light-emitting device11is reflected by reflector60A and travels forward. As illustrated inFIG. 7andFIG. 8, a portion of the light reflected by reflector60A (thin broken lines) enters protrusion80A through entry surface81A of protrusion80A. Light incident on protrusion80A travels into protrusion80A, exits through exit surface82A, and travels toward low beam lens30A.

Here, the difference in the refractive index of protrusion80A and the surrounding area (air) causes the light to refract. For example, the refractive index of protrusion80A is approximately 1.48 to 1.60, inclusive. With this, the light exiting through exit surface82A of protrusion80A travels more downward compared to when protrusion80A is omitted, as illustrated inFIG. 7. In other words, protrusion80A changes the direction of travel of light entering through entry surface81A to a more downward direction, and transmits the light through exit surface82A.

Thus, in focal plane of low beam lens30A, light that has passed through protrusion80A (indicated by the hold solid lines) travels below the path that the light would travel if protrusion80A were not provided (indicated by the thin broken lines). Low beam lens30A inversely projects the distribution of light passing through focal plane F, so light passing below a predetermined line in focal plane F passes above the line in front of low beam lens30A.

More specifically, light exiting exit surface82A and transmitted by low beam lens30A travels below and approximately perpendicular to central axis J in a side view, as illustrated inFIG. 7. Here, light exiting through exit surface82A (indicated by the bold solid lines) is transmitted in a direction more approximate to central axis J than the direction that the light would be transmitted, in if protrusion80A were not provided (indicated by the thin broken lines)—that is to say, is transmitted in a direction that is more horizontal. Thus, light passing through protrusion80A according to Embodiment 2 can illuminate an area farther ahead than when protrusion80A is not provided. In this way, according to Embodiment 2, light that would illuminate an area near vehicle body110can be directed farther ahead as a result of protrusion80A refracting light. This makes it possible to achieve an increase in lighting efficiency.

Note that light traveling in a downward direction as in the case when protrusion80A is not provided (i.e., the direction of light indicated by the thin broken lines) illuminates an area near automobile100. In this case, when the area near automobile100is excessively illuminated, areas far away from automobile100and areas to the sides of automobile100appear dark. In contrast, according to Embodiment 2, protrusion80A makes it possible to direct light that would illuminate an area near automobile100farther ahead. With this, a more comfortable driving environment can be created for the driver, which contributes to safer driving.

Moreover, as illustrated inFIG. 8, the light exiting through exit surface82A of protrusion80A travels more toward the oncoming traffic lane than when protrusion80A is not provided. In other words, protrusion80A changes the direction of travel of light entering through entry surface81A to a direction more toward the oncoming traffic lane (more to the left), and transmits the light through exit surface82A. More specifically, in focal plane F of low beam lens30A, light transmitted through protrusion80A (indicated by the bold solid lines) travels in a direction more toward the oncoming traffic lane (more to the left) than the direction that the light would travel in if protrusion80A were not provided (indicated by the thin broken lines).

Light exiting through exit surface82A and transmitted by low beam lens30A intersects central axis J in a top view, as illustrated inFIG. 8. In other words, light exiting through exit surface82A is transmitted toward the driving lane.

In this way, according to Embodiment 2, as a result of protrusion80A refracting light, light that would illuminate the oncoming traffic lane can be directed to the driving line (i.e., the lane in which the driver drives his or her own vehicle). This makes it possible to achieve an increase in lighting efficiency.

Light Reflected by Reflective Portion

Next, paths of light reflected by reflective portion54A according to Embodiment 2 will be described with reference toFIG. 9.

As illustrated inFIG. 9, a portion of light emitted from low beam light-emitting device11is reflected by reflective portion54A rather than reflector60A. Light reflected by reflective portion54A is further reflected by reflective film71A of shield70A and travels toward low beam lens30A. Moreover, light reflected by reflective film71A and transmitted by low beam lens30A intersects central axis J in a side view, as illustrated inFIG. 9. In other words, light reflected by reflective portion54A and reflective film71A illuminates an area above the horizon plane. This makes it possible to illuminate, for example, signs on the shoulder of the road or above the road. With this, a more comfortable driving environment can be created for the driver.

As described above, lighting apparatus1A according to Embodiment 2 is to be installed on automobile100and includes: low beam light-emitting device11; reflector60A that reflects light emitted from low beam light-emitting device11; low beam lens30A that is disposed in a path of light reflected by reflector60A and that transmits light from reflector60A along a predetermined lighting direction; and protrusion80A disposed between reflector60A and low beam lens30A. Protrusion.80A includes entry surface81A and exit surface82A, changes a direction of travel of light reflected by reflector60A and entering through entry surface81A, and transmits the light through exit surface82A toward low beam lens30A. Moreover, for example, automobile100according to Embodiment 2 includes lighting apparatus1A installed in the front portion of vehicle body110.

FIG. 10illustrates the change in the direction of travel of light caused by protrusion80A according to Embodiment 2. InFIG. 10, the region shaded with dots is the area illuminated by tight emitting from low beam lenses30A (i.e., the area illuminated by the low beams).

As described above, protrusion80A changes the direction of travel of light that would illuminate the oncoming traffic lane if protrusion80A were omitted, to a direction more toward the driving lane and farther away. In other words, as illustrated inFIG. 10, protrusion80A changes the direction of travel of light illuminating region90A so that the light illuminates region91A. With this, region91A can be brightly illuminated instead of reducing the brightness of region90A.

In this way, for example, the light-transmissive protrusion80A can change the conventional direction of travel of light traveling toward the oncoming traffic lane to a direction toward the driving lane (i.e., the lane in which the driver drives his or her own vehicle), and thereby brighten the driving lane. Thus, since this makes it possible to efficiently use light, it is possible to achieve an increase in lighting efficiency.

Moreover, for example, protrusion80A is disposed between reflector60A and focal plane F located on the same side of low beam lens30A as reflector60A.

With this configuration, the distance between protrusion80A and low beam lens30A can be increased, and therefore the direction of travel of light can be changed to a greater degree.

Moreover, for example, protrusion80A is disposed in a position offset from central axis J of low beam lens30A.

With this configuration, for example, the conventional direction of travel of light traveling toward the oncoming traffic lane can be changed to a direction toward the driving lane, and thereby brighten the driving lane.

Moreover, for example, entry surface81A has a convex surface protruding toward reflector60A, and exit surface82A has a concave surface receding toward reflector60A.

Moreover, for example, protrusion80A includes side surface83A and side surface84A which are side surfaces between entry surface81A and exit surface82A, are parallel to the optical axis of low beam light-emitting device11, and are slanted relative to central axis J of low beam lens30A.

Moreover, for example, light exiting through exit surface82A and transmitted by low beam lens30A intersects central axis J in a top view, as illustrated inFIG. 8.

With this configuration, the light-transmissive protrusion80A can change the conventional direction of travel of light traveling toward the oncoming traffic lane to a direction toward the driving lane (i.e., the lane in which the driver drives his or her own vehicle), and thereby brighten the driving lane. Thus, since this makes it possible to efficiently use light, it is possible to achieve an increase in lighting efficiency.

Moreover, for example, light exiting through exit surface82A and transmitted by low beam lens30A travels below and approximately parallel to central axis J in a side view.

With this configuration, the light-transmissive protrusion80A changes the conventional direction of travel of light traveling forward and downward of vehicle body110to a direction comparatively farther ahead, to more brightly illuminate an area farther ahead. Thus, since this makes it possible to efficiently use light, it is possible to achieve an increase in lighting efficiency.

With this configuration, since a resin material is used, protrusion80A can be easily formed.

Moreover, for example, lighting apparatus1A further includes shield70A that is disposed between reflector60A and low beam lens30A and blocks a portion of the light reflected by reflector60A, and protrusion80A protrudes upward from the ceiling of shield70A.

With this configuration, since protrusion80A is provided on the ceiling of shield70A, positioning of shield70A and protrusion80A can be performed simultaneously.

Moreover, for example, protrusion80A is integrally formed with shield70A.

With this configuration, since shield70A and protrusion80A are integrally formed, assembly can be simplified.

Moreover, for example, the surface of shield70A nearest low beam lens30A has a reflective film formed thereon, and entry surface81A and exit surface82A of protrusion80A do not have a reflective film formed thereon.

With this configuration, for example, by forming reflective film71A, light can be emitted above the horizon plane. As a result, signs above the road, for example, can be illuminated, and a more comfortable driving environment can be created for the driver.

As described above, lighting apparatus1A according to Embodiment 2 is installed in automobile100and includes: low beam light-emitting device11; first heat sink51A thermally coupled to low beam light-emitting device11; reflector60A that reflects light emitted from low beam light-emitting device11; low beam lens30A that is disposed in a path of light reflected by reflector60A and that transmits, light from reflector60A along a predetermined direction; high beam light-emitting device21disposed further in the lighting direction than low beam light-emitting device11; and second heat sink52A that is thermally coupled to high beam light-emitting device21and disposed so that reflector60A is between first heat sink51A and second heat sink52A. Second heat sink52A includes: extension portion53A extending long the lighting direction beyond reflector60A; and reflective portion54A that is fixed to extension portion53A and reflects light emitted from low beam light-emitting device11and not reflected by reflector60A.

With this configuration, light emitted from low beam light-emitting device11can be reflected by reflective portion54A fixed to second heat sink52A, instead of by reflector60A, and illuminate an area above the horizon plane. Thus, since there is no need to increase the size of reflector60A, there is also no need to increase the rigidity of reflector60A and no need to increase the size of the structure for supporting reflector60A (more specifically, the first heat sink51A). For example, when reflector60A is extended, the size of the lighting apparatus increases by an amount equal to the thickness of reflector60A and the size of the gap between reflector60A and second heat sink52A. In contrast, with Embodiment 2, lighting apparatus1A can be made compact.

Moreover, for example, lighting apparatus1A further includes reflective film71A that directs light toward low beam lens30A by reflecting light reflected by reflective portion54A.

With this configuration, light reflected by reflective portion54A can be directed in a desired direction. This makes it possible to illuminate an area above the horizon plane, thereby making it possible to illuminate, for example, signs on the shoulder of the road or above the road. With this, a more comfortable driving environment can be created for the driver.

Moreover, for example, reflective portion54A is a reflective film integrally formed with extension portion53A.

With this configuration, reflective portion54A can be realized, with a simple structure by using the surface of second heat sink52A. Note that since light reflected by reflective portion54A is light to be widely emitted in front of the vehicle and upward, reflective portion54A is not required to have as precise control over the travel direction of light as reflector60A. For example, the surface of second heat sink52A can be used.

Moreover, for example, high beam light-emitting devices21through23are thermally coupled to extension portion53A.

With this configuration, effective dissipation of heat from high beam light-emitting devices21through23is possible with second heat sink52A.

Moreover, for example, light reflected by reflective portion54A and transmitted by low beam lens30A intersects central axis J of low beam lens30A in a side view.

This makes it possible to illuminate an area above the horizon plane, thereby making it possible to, for example, illuminate signs and such on the shoulder of the road or above the road. With this, a more comfortable driving environment can be created for the driver.

Moreover, for example, low beam light-emitting device11, first heat sink51A, reflector60A, low beam lens30A, high beam light-emitting devices21through23, and second heat sink52A form a unit that fits within a predetermined circular region when viewed from the lighting direction.

With this configuration, low beam light-emitting device11, low beam lens30A, high beam light-emitting devices21through23, and high beam lens40A can be formed in a unit, which makes it possible to achieve a compact lighting apparatus1A. In other words, lighting apparatus1A according to Embodiment 2 is a lamp that is a single unit that can emit a low beam and a high beam. Therefore, compared to when separate lamps for low beam use and high beam use are required, the design freedom of automobile100can be greatly increased.

Variations

In Embodiment 2, reflective portion54A is exemplified as a reflective film integrally formed with extension portion53A of second heat sink52A, but reflective portion54A is not limited to this example. For example, reflective portion54A may be formed as a separate component from second heat sink52A.

FIG. 11is a cross sectional view of lighting apparatus1Aa according to the present variation. Similar toFIG. 6,FIG. 11is a cross section taken along line VI-VI inFIG. 5.

In contrast to lighting apparatus1A according to Embodiment 2, lighting apparatus1Aa includes second heat sink52Aa instead of second heat sink52A. Second heat sink52Aa includes reflective portion54Aa instead of reflective portion54A.

Reflective portion54Aa is a reflective plate separate from reflector60A. Reflective portion54Aa is fixed to extension portion53A of second heat sink52Aa. Reflective portion54Aa is, for example, formed by resin molding using a heat resistant resin, and a reflective film is formed on the surface of reflective portion54Aa, similar to reflector60A. The reflective film is, for example, an aluminum deposition film.

With this configuration, compared to when reflector60A is extended, the size of reflector60A reduced. Thus, there is no need to increase the rigidity of reflector60A and no need to increase the size of the structure for supporting reflector60A (the first heat sink51A). This in turn makes it possible to achieve a compact lighting apparatus1Aa.

Next, the lighting apparatus according to Embodiment 3 will be described.

The conventional lighting apparatus described in the background section includes a protrusion acting as a shield that blocks a portion of the light reflected from a reflector in order to reduce glare for the oncoming traffic lane. As a result, a portion of the light emitted by the light-emitting device is blocked by the protrusion acting as a shield and not emitted forward. In other words, with the conventional lighting apparatus, light emitted by the light-emitting device cannot be effectively used for illumination purposes, and thus has a low lighting efficiency.

In view of this, one object of the present disclosure is to provide a lighting apparatus which can achieve a further increase in lighting efficiency and a mobile object including the lighting apparatus.

In order to achieve the above described object, the lighting apparatus according to Embodiment 3 is a lighting apparatus to be installed on a mobile object, and includes: a light-emitting device, a reflector that reflects light emitted from the light-emitting device; a lens disposed in a path of light reflected by the reflector; and a light guide disposed between the reflector and the lens. The light guide changes a traveling direction of the light from the reflector to guide the light to the lens.

According to Embodiment 3, lighting efficiency can be further increased.

Lighting Apparatus

First, lighting apparatus1B according to Embodiment 3 will be described with reference toFIG. 12throughFIG. 15.

FIG. 12is a front view of lighting apparatus1B according to Embodiment 3.FIG. 13is a cross sectional view of lighting apparatus1B according to Embodiment 3, taken along line XIII-XIII inFIG. 12. More specifically,FIG. 13is vertical cross section taken down the center of lighting apparatus1B.

FIG. 14is a cross sectional view of lighting apparatus1B according to Embodiment 3, taken along line XIII-XIII inFIG. 12, and illustrates a path of light passing through light guide71B and a path of light passing through protrusion80A.FIG. 15is a cross sectional view of lighting apparatus1B according to Embodiment 3, taken along line XV-XV inFIG. 12, and illustrates paths of light passing through light guide71B. Moreover, inFIG. 15, the vertically drawn dotted and dashed line is central axis J of low beam lens30A. Central axis J passes through the approximate center of lighting apparatus1B.

Note that inFIG. 14andFIG. 15, the bold solid line arrows indicate the paths of light passing through light guide71B and protrusion80A according to Embodiment 3. The thin broken line arrows are provided as a comparative example of paths of light when light guide71B and protrusion80A according to Embodiment 3 is not provided.

Similar to lighting apparatus1A according to Embodiment 2, lighting apparatus1B according to Embodiment 3 is installed on a mobile object. Lighting apparatus1B is, for example, attached to automobile100illustrated inFIG. 1. In other words, automobile100may include, in the front of vehicle body110, lighting apparatus1B according to Embodiment 3 instead of lighting apparatus1according to Embodiment 1.

As illustrated inFIG. 12andFIG. 13, lighting apparatus1B includes, as the main body of the lamp, low beam light source module10A, high beam light source module20A, low beam lens30A, high beam lens40A, heat dissipator50A, reflector60A, shield70B, light guide71B, and protrusion80A. Although not illustrated in the Drawings, lighting apparatus1B further includes a lighting controller that controls low beam light source module10A and high beam light source module20A.

As illustrated inFIG. 12, lighting apparatus1B is configured to fit within a predetermined circular region when viewed from the lighting direction (i.e., when viewed along the Z axis). More specifically, low beam light source module10A, high beam light source module20A, low beam lens30A, high beam lens40A, heat dissipator50A, reflector60A, shield70B, light guide71B, and protrusion80A form a unit that fits within a predetermined circular region when viewed along the Z axis. The predetermined circular region is, for example,70 mm (in diameter).

Hereinafter, each element of lighting apparatus1B will be described in detail. Note that description of configurations that are the same as in Embodiment 2 are omitted or condensed.

Shield

Similar to shield70A according to Embodiment 2, Shield70B is one example of a shield that blocks a portion of the light reflected by reflector60A. More specifically, shield70B is a structure that defines a predetermined cutoff line—which is a boundary between dark and light areas—by blocking a portion of light emitted by low beam light source module10A.

Shield70B is disposed between reflector60A and low beam lens30A. More specifically, shield70B is fixed to first heat sink51A.

Shield70B is, for example, formed using a heat resistant resin or fiber reinforced plastic, similar to reflector60A. The surface of shield70B nearest low beam lens30A has a reflective film formed thereon. The reflective film is, for example, an aluminum deposition film.

Light Guide

Light guide71B is a portion of shield70B and is located between reflector60A and low beam lens30A.

As illustrated inFIG. 13throughFIG. 15, light guide71B includes entry surface72B, exit surface73B, ceiling surface74B, and bottom surface75B. Light guide71B diffuses, about central axis J, light reflected by reflector60A and entering through entry surface72B, and transmits the light through exit surface73B toward low beam lens30A. More specifically, light guide71B diffuses, toward the driving lane, light entering through entry surface72B, and directs the light to illuminate an area above the horizon line.

As illustrated inFIG. 15, entry surface72B has a convex surface receding away from reflector60A. Entry surface72B includes, for example, a portion of a spheroid.

Entry surface72B is disposed in a position offset from central axis J in a top view. The direction in which entry surface72B is offset from central axis J and the amount of offset (i.e., the distance between the two) is substantially equal to the direction in which entry surface81A of protrusion80A is offset from central axis J and the amount of offset (i.e., the distance between the two). In Embodiment 3, entry surface72B is offset to the driving lane side (right side) of central axis J.

As illustrated inFIG. 15, exit surface73B has a concave surface receding toward reflector60A. Exit surface73B includes, for example, a portion of a spheroid.

Exit surface73B is disposed so as to intersect central axis J in a top view. More specifically, as illustrated inFIG. 15, exit surface73B is disposed such that the center in a top view intersects central axis J.

Ceiling surface74B is a top surface between entry surface72B and exit surface73B of light guide71B. More specifically, ceiling surface74B is the surface that opposes second heat sink52A. A reflective film is formed on ceiling surface74B of light guide71B. This makes it possible to inhibit light from entering through ceiling surface74B.

Bottom surface75B is a bottom surface between entry surface72B and exit surface73B of light guide71B. More specifically, bottom surface75B is the surface that opposes first heat sink51A. A reflective film is formed on bottom surface75B of light guide71B.

Light guide71B is integrally formed with shield70B. More specifically, when the reflective film is formed on the surface of shaped heat-resistant resin or fiber reinforced plastic, light guide71B can be formed without forming a reflective film on entry surface72B and exit surface73B. Moreover, protrusion80A can be formed in the same manner. Note that the reflective film is, for example, an aluminum deposition film.

Note that in Embodiment 3, a space is formed between first heat sink51A and second heat sink52A where low beam light source module10A, reflector60A, light guide71B, and protrusion80A are disposed, as illustrated inFIG. 13. Moreover, side surface83A and side surface84A of protrusion80A are approximately flush with a portion of a side surface of light guide71B (the portion on the entry surface72B side).

Light Passing Through Light Guide

Next, paths of light reflected by passing through light guide71B according to Embodiment 3 will be described with reference toFIG. 14andFIG. 15.

Light emitted upward by low beam light-emitting device11is reflected by reflector60A and travels forward. As illustrated inFIG. 14andFIG. 15, a portion of the light reflected by reflector60A (indicated by the thin broken lines) is incident on entry surface72B of light guide71B and enters light guide71B. Light incident on light guide71B travels into light guide71B, exits through exit surface73B, and travels toward low beam lens30A.

Here, the difference in the refractive index of light guide71B and the surrounding area (air) causes the light to refract. For example, the refractive index of light guide71B is approximately 1.48 to 1.60, inclusive. Moreover, light inside light guide71B is reflected by bottom surface75B, as illustrated inFIG. 14. With this, light exiting through exit surface73B of light guide71B travels in an upward direction, as illustrated inFIG. 14. In other words, light guide71B changes the direction of travel of light entering through entry surface72B to an upward direction, and transmits the light through exit surface73B. Note that in the example illustrated inFIG. 14, light is exemplified as only being reflected off bottom surface75B, but a portion of light inside light guide71B is also reflected off ceiling surface74B.

With this, light exiting through exit surface73B of light guide71B (bold solid line) and transmitted by low beam lens30A travels above central axis J, in a direction approximately parallel to central axis J, as illustrated inFIG. 14. In other words, light exiting through exit surface73B of light guide71B illuminates an area above the horizon plane.

Moreover, light exiting through exit surface73B of light guide71B diffuses about central axis J more widely than when light guide71B is omitted, as illustrated inFIG. 15. More specifically, in focal plane F of low beam lens30A, light that has passed through light guide71B (indicated by the bold solid lines) is diffused wider about central axis J than if light guide71B were omitted (indicated by the thin broken lines). Thus, since low beam lens30A inversely projects a distribution of light passing through focal plane F, diffused light is projected in front of low beam lens30A.

FIG. 16illustrates the change in the direction of travel of light caused by light guide71B and protrusion80A according to Embodiment 3. InFIG. 16, the region shaded with dots is the area illuminated by light emitting from low beam lenses30A (i.e., the area illuminated by the low beams).

As described above, light guide71B can change the direction of travel of light that would illuminate the oncoming traffic lane if light guide71B were omitted, to a direction that light illuminates an area above the horizon and illuminates a broader area. In other words, as illustrated inFIG. 16, light guide71B can, for example, brightly illuminate area91B instead of reducing the brightness of region90B. With this, for example, signs and such above the road, for example, can be illuminated, and a more optimal driving environment can be created for the driver.

As described above, lighting apparatus1B according to Embodiment 3 is installed in automobile100and includes: low beam light-emitting device11; reflector60A that reflects light emitted from low beam light-emitting device11; low beam lens30A disposed in a path of light reflected by reflector60A; and light guide71B disposed between reflector60A and low beam lens30A. Light guide71B includes entry surface72B and exit surface73B, diffuses, about central axis J of low beam lens30A, light reflected by reflector60A and entering through entry surface72B, and transmits the light through exit surface73B toward low beam lens30A.

With this configuration, light guide71B can change the direction of travel of light that would illuminate the oncoming traffic lane if light guide71B were omitted to a direction light illuminates an area above the horizon and illuminates a broader area. Thus, since this makes it possible to efficiently use light, it is possible to achieve an increase in lighting efficiency. Moreover, for example, signs and such above the road, for example, can be illuminated, and a more optimal driving environment can be created for the driver.

Moreover, for example, a reflective film is formed on bottom surface75B between entry surface72B and exit surface73B of light guide71B.

Moreover, for example, a reflective film is formed on ceiling surface74B between entry surface72B and exit surface73B of light guide71B.

This makes it possible to inhibit light from entering light guide71B through ceiling surface74B. Moreover, light traveling through light guide71B can be inhibited from exiting through ceiling surface74B. Moreover, by allowing for reflection to occur between ceiling surface74B and bottom surface75B, light can be transmitted through exit surface73B in a nearly horizontal direction.

Moreover, for example, entry surface72B has a concave surface receding away from reflector60A, and exit surface73B has a concave surface receding toward reflector60A.

With this configuration, the difference in the indexes of refraction between light guide71B and the surrounding area (air) can be used to change the direction of travel of light and diffuse the light.

Moreover, for example, entry surface72B is offset from central axis J of low beam lens30A in a top view, and exit surface73B is disposed so as to intersect central axis J of low beam lens30A in a top view.

With this configuration, since the conventional (when light guide71B is omitted) direction of travel of light traveling toward the oncoming traffic lane can be diffused, it is possible to achieve an increase in lighting efficiency.

Moreover, for example, lighting apparatus1B further includes light-transmissive protrusion80A that protrudes upward from ceiling surface74B of light guide71B. Moreover, for example, protrusion80A protrudes upward from a portion of ceiling surface74B of light guide71B where no reflective film is formed.

With this configuration, for example, the light-transmissive protrusion80A can change the conventional direction of travel of light traveling toward the oncoming traffic lane to a direction toward the driving lane (i.e., the lane in which the driver drives his or her own vehicle), and thereby brighten the driving lane. Thus, since this makes it possible to efficiently use light, it is possible to achieve an increase in lighting efficiency.

For example, as illustrated inFIG. 14, a portion of the light reflected by reflector60A (thin broken lines) enters protrusion80A through entry surface81A of protrusion80A. Light incident on protrusion80A travels into protrusion80A, exits through exit surface82A, and travels toward low beam lens30A.

In this way, according to Embodiment 3, as a result of protrusion80A refracting light, light that would illuminate the oncoming traffic lane can be directed to the driving line (i.e., the lane in which the driver drives his or her own vehicle). More specifically, protrusion80A changes the direction of travel of light that would illuminate the oncoming traffic lane if protrusion80A were omitted, to a direction more toward the driving lane and farther away. In other words, as illustrated inFIG. 16, protrusion80A changes the direction of travel of light illuminating region90B to a direction that illuminates region92B. With this, region92B can be brightly illuminated instead of reducing the brightness of region90B.

Moreover, for example, light exiting through exit surface73B and transmitted by low beam lens30A travels above and approximately parallel to central axis J in a side view.

This makes it possible to illuminate an area above the horizon plane, thereby making it possible to, for example, illuminate signs and such on the shoulder of the road or above the road. With this, a more comfortable driving environment can be created for the driver.

With this configuration, since a resin material is used, light guide71B can be easily formed.

Other Variations

Hereinbefore the lighting apparatus according to the present disclosure has been described based on the above examples and variations, but the present disclosure is not limited to those examples.

For example, in Embodiments 1 through 3 above, the lighting apparatus is exemplified as including a plurality of high beam light-emitting devices21through23, but the lighting apparatus may include only a single high beam light-emitting device.

Moreover, for example, in Embodiment 1 above, heat dissipator50is exemplified as having a back end portion that extends upward, but heat dissipator50is not limited to this example. For example, heat dissipator50may extend downward and, alternatively, may extend backward. For example, heat dissipator50may extend downward from the bottom surface (i.e., from the surface opposite placement surface51).

Moreover, for example, in Embodiment 2 above, protrusion80A is exemplified as being disposed between focal plane F of low beam lens30A and reflector60A, but the location of protrusion80A is not limited to this example. Protrusion80A may be disposed on the same side of low beam lens30A as focal plane F.

Moreover, for example, in Embodiment 2 above, protrusion80A and shield70A are exemplified as being integrally formed, but protrusion80A and shield70A are not limited to this example. Protrusion80A and shield70A may be formed as separate components. Moreover, protrusion80A may be fixed to first heat sink51A.

For example, in Embodiment 3 above, ceiling surface74B and bottom surface75B of light guide71B are exemplified as having a reflective film thereon, but no reflective film may be formed on ceiling surface74B and bottom surface75B. Even in this case, light traveling through light guide71B is reflected by ceiling surface74B and bottom surface75B as it travels due to the difference in the refractive index of light guide71B and the surrounding area.

Moreover, for example, in Embodiment 3 above, protrusion80A and light guide71B are exemplified as being integrally formed, but protrusion80A and light guide71B are not limited to this example. Protrusion80A and light guide71B (or shield70B) may be formed as separate components. Moreover, lighting apparatus1B is not required to include protrusion80A.

Moreover, for example, the shapes and arrangement of light guide71B and protrusion80A are not limited to the examples given above. For example, protrusion80A may be disposed to the low beam lens30A side of focal plane F.

Moreover, for example, in the above embodiments, automobile100is exemplified as including two lighting apparatuses1(headlamps120), but automobile100is not limited to this example. For example, automobile100may include three or more lighting apparatuses1, such as two lighting apparatuses1on each of the left and right sides of vehicle body110, and, alternatively, may include only one lighting apparatus1.

For example, the above embodiments are applied to headlamps which emit low beams and high beams is given, but may be applied to fog lamps or day time running light (DRM) headlamps.

Moreover, for example, in the above embodiments, LEDs are given as an example of the light-emitting devices, but laser devices such as semiconductor lasers, or light-emitting devices such as organic electro-luminescence (EL devices) and non-organic EL devices may be used.

Moreover, for example, in the above embodiments, automobile100is exemplified as a four-wheeled automobile, but automobile1may be a different automobile such as a two-wheeled automobile.