Lighting device and headlight having a reflector, lenses and light-shielding members

A lighting device includes: a light emission part; a reflector disposed above the light emission part and configured to reflect a first portion of light emitted from the light emission part; a first lens having a first incident face through which light reflected by the reflector enters; a second lens disposed higher than the first lens, and having a second incident face through which a second portion of the light emitted from the light emission part enters, wherein the second incident face is father than the first incident face from the light emission part; a first light shielding member disposed between the first lens and the second lens; a second light shielding member between the light emission part and the first lens; a third light shielding member between the light emission part and the second lens; and an actuator configured to move the second and third light shielding members.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Japanese Patent Application No. 2020-058029, filed on Mar. 27, 2020, and Japanese Patent Application No. 2020-148415, filed on Sep. 3, 2020, the disclosures of which are hereby incorporated by reference in their entireties.

BACKGROUND

The present disclosure relate to lighting devices and headlights.

As a vehicular headlight of an automobile and the like, a lighting device capable of switching between low beam and high beam light distribution patterns has been known. For such a lighting device, there is a need to achieve both low beam and high beam light distribution patterns using a single light emission part. See, for example, Japanese Patent Publication No. 2017-103189.

SUMMARY

One object of certain embodiments of the present disclosure is to provide a lighting device and a headlight capable of achieving both low beam and high beam light distribution patterns using a single light emission part.

A lighting device according to one embodiment includes: a light emission part, a reflector, a first lens, a second lens, a first light shielding member, a second light shielding member, a third light shielding member, and an actuator. The reflector is disposed above the light emission part, and reflects a first portion of light emitted from the light emission part. The first lens has a first incident face from which light reflected by the reflector enters. The second lens is disposed higher than the first lens in an up-down direction, and has a second incident face from which a second portion of the light emitted from the light emission part enters. A distance between the light emission part and the second incident face in a horizontal direction is smaller than a distance between the light emission part and the first incident face in the horizontal direction. The first light shielding member is disposed between the first lens and the second lens in the up-down direction. The second light shielding member whose position in the horizontal direction is between a position of the light emission part and a position of the first lens. The third light shielding member whose position in the horizontal direction is between a position of the light emission part and a position of the second lens. The actuator is capable of switching between a light-shielded state and a non-light-shielded state by moving the second light shielding member and the third light shielding member. In the light-shielded state, the second light shielding member shields a portion of light advancing from the reflector towards the first incident face, and the third light shielding member shields the second portion of the light advancing from the light emission part towards the second incident face. In the non-light-shielded state, the second light shielding member does not shield the light advancing from the reflector towards the first incident face, and the third light shielding member does not shield the second portion of the light.

A lighting device according to another embodiment includes: a substrate having an upper face and a lower face, a light emission part disposed on the upper face of the substrate, a reflector, a first lens, a second lens, a first light shielding member, a second light shielding member, a third light shielding member, and an actuator. The reflector is disposed on the upper face of the substrate to cover the light emission part, and reflects a first portion of light emitted from the light emission part. The first lens has a first incident face form which the light reflected by the reflector enters, a first emission face from which light entering the first incident face exits, and an upper face located between the first incident face and the first emission face. The second lens has a second incident face from which a second portion of the light emitted from the light emission part enters, a second emission face from which the light entering the second incident face exits, and a lower face located between the second incident face and the second emission face. The second lens is disposed higher than the first lens in a direction from the lower face to the upper face of the substrate, and a distance from a center of the light emission part to the second incident face is smaller than a distance from the center of the light emission part to the first incident face. The first light shielding member is disposed between the upper face of the first lens and the lower face of the second lens. The second light shielding member whose position in the direction from the light emission part to the first lens is between a position of the light emission part and a position of the first lens. The third light shielding member whose position in the direction from the light emission part to the second lens is between a position of the light emission part and a position of the second lens. The actuator is capable of switching between a light-shielded state and a non-light-shielded state by moving the second light shielding member and the third light shielding member. In the light-shielded state, the second light shielding member shields a portion of light advancing from the reflector towards the first incident face, and the third light shielding member shields the second portion of the light advancing from the light emission part towards the second incident face. In the non-light-shielded state, the second light shielding member does not shield the light advancing from the reflector towards the first incident face, and the third light shielding member does not shield the second portion of the light.

According to other embodiments, headlights are provided that include the lighting devices described above.

According to certain embodiments, a lighting device and a headlight capable of achieving both low beam and high beam light distribution patterns using a single light emission part can be provided.

DETAILED DESCRIPTION

A lighting device according to one embodiment includes: a substrate having an upper face and a lower face, a light emission part disposed on the upper face of the substrate, a reflector, a first lens, a second lens, a first light shielding member, a second light shielding member, a third light shielding member, and an actuator. The reflector is disposed on the upper face of the substrate to cover the light emission part, and reflects a first portion of light emitted from the light emission part. The first lens has a first incident face form which the light reflected by the reflector enters, a first emission face from which light entering the first incident face exits, and an upper face located between the first incident face and the first emission face. The second lens has a second incident face from which a second portion of the light emitted from the light emission part enters, a second emission face from which the light entering the second incident face exits, and a lower face located between the second incident face and the second emission face. The second lens is disposed higher than the first lens in a direction from the lower face to the upper face of the substrate, and a distance from a center of the light emission part to the second incident face is smaller than a distance from the center of the light emission part to the first incident face. The first light shielding member is disposed between the upper face of the first lens and the lower face of the second lens. The second light shielding member whose position in the direction from the light emission part to the first lens is between a position of the light emission part and a position of the first lens. The third light shielding member whose position in the direction from the light emission part to the second lens is between a position of the light emission part and a position of the second lens. The actuator is capable of switching between a light-shielded state and a non-light-shielded state by moving the second light shielding member and the third light shielding member. In the light-shielded state, the second light shielding member shields a portion of light advancing from the reflector towards the first incident face, and the third light shielding member shields the second portion of the light advancing from the light emission part towards the second incident face. In the non-light-shielded state, the second light shielding member does not shield the light advancing from the reflector towards the first incident face, and the third light shielding member does not shield the second portion of the light.

An example of a lighting device according to the embodiment will be explained below with reference to the drawings.

FIG. 1is a perspective view of a lighting device according to an embodiment.

FIG. 2is an exploded perspective view of the lighting device.

FIG. 3is a partial cross-sectional view of the lighting device in a light-shielded state.

FIG. 4is a partial cross-sectional view of the lighting device in a non-light-shielded state.

A lighting device100according to the embodiment can be used as a headlight of a vehicle such as an automobile. The lighting device100when installed in a vehicle can be switched between a low beam light distribution pattern and a high beam light distribution pattern.

In the explanation below, an XYZ orthogonal coordinate system will be used. For the purpose of making the explanation easier to understand, in the lighting device100installed in a vehicle, the direction from the lower side to the upper side of the vehicle will be referred to as the “up-down direction Z.” A direction orthogonal to the up-down direction Z will be referred to as a “horizontal direction.” With respect to horizontal directions when the lighting device100is installed in a vehicle, the direction from the rear to the front of the vehicle will be referred to as the “front-back direction X,” and the direction from the right side to the left side of the vehicle will be referred to as the “left-right direction Y.” However, terms indicating specific directions or positions (e.g., “up,” “upward,” “down,” “downward,” “right,” “left,” and others including these) merely indicate relative positions without being limited to the above description.

As shown inFIG. 1andFIG. 2, the lighting device100according to the embodiment includes a light emission part110, a reflector120, a first lens130, a second lens140, a first light shielding member150, a second light shielding member160, a third light shielding member170, and an actuator180.

As shown inFIG. 3andFIG. 4, the reflector120is disposed above the light emission part110, and reflects a first portion L1of the light emitted by the light emission part110.

The first lens130has a first incident face131from which the light L1areflected by the reflector120enters.

The second lens140is positioned higher than the first lens130in the up-down direction Z. The second lens140has a second incident face141from which a second portion L2of the light emitted by the light emission part110enters. The distance E2between the light emission part110and the second incident face141in the horizontal direction (the front-back direction X) is smaller than the distance E1between the light emission part110and the first incident face131in the horizontal direction (the front-back direction X). Here, the distances E1and E2mean the distances from the center of the light emission part110.

The first light shielding member150is disposed between the first lens130and the second lens140in the up-down direction Z. In the description herein, “light shielding” means that the transmittance of the irradiated light is less than 1%.

The position of the second light shielding member160in the horizontal direction (the front-back direction X) is between the position of the light emission part110and the position of the first lens130. “The position of the second light shielding member160in the horizontal direction (the front-back direction X) is between the position of the light emission part110and the position of the first lens130” merely specifies the relative positions of the second light shielding member160, the light emission part110, and the first lens130in the horizontal direction, but does not specify that the light emission part110, the second light shielding member160, and the first lens130are positioned on a straight line extending in the horizontal direction.

The position of the third light shielding member170in the horizontal direction (the front-back direction X) is between the position of the light emission part110and the position of the second lens140. Similarly, “the position of the third light shielding member170in the horizontal direction (the front-back direction X) is between the position of the light emission part110and the position of the second lens140” merely specifies the relative positions of the third light shielding member170, the light emission part110, and the second lens140in the horizontal direction, but does not specify that the light emission part110, the third light shielding member170, and the second lens140are positioned on a straight line extending in the horizontal direction.

The actuator180can switch between a light-shielded state and a non-light-shielded state by moving the second light shielding member160and the third light shielding member170as indicated by the arrow a1inFIG. 1.

As shown inFIG. 3, in the light-shielded state, the second light shielding member160shields a portion of the light L1aadvancing from the reflector120towards the first incident face131, and the third light shielding member170shields the second portion L2advancing from the light emission part110towards the second incident face141. When the light emission part110is turned on in the light-shielded state, the lighting device100emits light having a low beam light distribution pattern.

As shown inFIG. 4, in the non-light-shielded state, the second light shielding member160does not shield the light L1aadvancing from the reflector120towards the first incident face131, and the third light shielding member170does not shield the second portion L2. When the light emission part110is turned on in the non-light shielded state, the lighting device100emits light having a high beam light distribution pattern.

In both the light-shielded and non-light-shielded states, the position of the second light shielding member160in the horizontal direction (the front-back direction X) is between the position of the light emission part110and the position of the first lens130. Similarly, in both the light-shielded and non-light-shielded states, the position of the third light shielding member170in the horizontal direction (the front-back direction X) is between the position of the light emission part110and the position of the second lens140. Each part of the lighting device100will be described in detail below.

The lighting device100includes a substrate191.

The substrate191, for example, is a wiring substrate in which wires to be connected to the light emission part110are provided in a base material such as a resin. The surfaces of the substrate191include an upper face191aand a lower face191blocated opposite the upper face191a.

The upper face191aand the lower face191bare flat faces parallel to the front-back direction X and the left-right direction Y. A light emission part110is mounted on the upper face191a.Furthermore, a reflector120is attached to the upper face191aso as to cover the light emission part110.

A heatsink192is fastened to the lower face191b.As shown inFIG. 2, the heatsink192is provided with through holes192apassing through the heatsink192in the up-down direction Z. The substrate191is provided with through holes191cpassing through the substrate191in the up-down direction Z.

As shown inFIG. 3andFIG. 4, the light emission part110in this embodiment includes a light emitting element111and a wavelength conversion member112that converts the wavelength of the light emitted from the light emitting element111. The light emitting element111, for example, is an LED (light emitting diode). In this embodiment, the color of the light emitted by the light emitting element111is blue. The wavelength conversion member112contains wavelength conversion particles such as phosphor particles. The color of the light emitted by the wavelength conversion member112is yellow. The color of the light emitted by the light emission part110is white resulting from mixing the blue light from the light emitting element111and the yellow light from the wavelength conversion member112. The light emitting element111can emit green or red light, and the wavelength conversion member112can emit green or red light. The number of light emitting elements configuring the light emission part110can be one or more. Similarly, the number of wavelength conversion members provided in the light emission part110can be one or more.

FIG. 5is a perspective view of a reflector of the light emitting device.

FIG. 6is a cross-sectional view of the reflector and the substrate of the light emitting device.

As shown inFIG. 5, the reflector120in this embodiment includes a main body121, a first attaching part122, and a second attaching part123. The reflector120is, for example, formed of a metal material such as aluminum.

The main body121in this embodiment is a concave mirror which is open in the front and bottom. The surfaces of the main body121include an inner face121a,an outer face121b, a lower face121c,and a front face121d.

As shown inFIG. 6, the inner face121asubstantially has a shape formed by rotating a curve D1, which becomes more distant towards the front from the central axis C1extending in the front-back direction X, by 180 degrees about the central axis C1. The curve D1is, for example, made by combining multiple parabolas. The inner face121afaces the light emission part110. The central axis C1passes through the center of the light emission part110in a top view.

The outer face121bis located opposite to the inner face121a.The outer face121bsubstantially has a shape formed by rotating a curve D2, which becomes more distant from the central axis C1towards the front, by 180 degrees about the central axis C1.

The lower face121cmeets the lower edge of the inner face121aand is provided in the periphery of the inner face121a.The lower face121cis in contact with the upper face191aof the substrate191.

The front face121dis located between the front edge of the inner face121aand the front edge of the outer face121b.As shown inFIG. 5, the front face121dhas a first region121emeeting the front edge of the lower face121con the right side, a second region121fmeeting the front edge of the lower face121con the left side, and a third region121glocated between the first region121eand the second region121f. The first region121eand the second region121fare substantially perpendicular to the upper face191aof the substrate191. The third region121gis curved, recessed towards the back.

The first attaching part122is attached to the substrate191. The first attaching part122protrudes rearwards from the main body121to be in contact with the upper face191aof the substrate191. The first attaching part122has a plate-like shape. The first attaching part122is provided with first through holes122apassing through the first attaching part122in the up-down direction Z. As shown inFIG. 2, in the first through holes122aand the through holes191cof the substrate191, fasteners such as screws or rivets for fastening the reflector120to the substrate191will be provided.

The actuator180is attached to the second attaching part123. As shown inFIG. 5, the second attaching part123protrudes upwards from the main body121. The second attaching part123is provided with a second through hole123apassing through the second attaching part123in the front-back direction X. As shown inFIG. 3, the motor181of the actuator180is placed through the second through hole123a. Furthermore, as shown inFIG. 5, the second attaching part123is provided with third through holes123bpassing through the second attaching part123in the front-back direction X. As shown inFIG. 2, in the third through holes123band the through holes182aof the holder182of the actuator180explained later, fasteners such as screws or rivets for fastening the holder182to the reflector120will be provided.

The construction of the reflector120is not limited to what has been described above. For example, the reflector120can be formed of a resin material provided with a reflecting layer formed of a metal such as aluminum on the inner face121aof the main body121. Moreover, the reflector120does not have to have a second attaching part123. In this case, the actuator180can be attached to another constituent element other than the reflector120, such as the substrate191or the heatsink192of the lighting device100.

As shown inFIG. 3, the first lens130, disposed in front of the lower portion of the reflector120and the substrate191, is positioned apart from the reflector120and the substrate191. The upper edge130aof the first lens130is positioned higher than the upper face191aof the substrate191. The lower edge130bof the first lens130is positioned lower than the lower face191bof the substrate191.

FIG. 7is a perspective view of a first lens, a second lens, and a first light shielding member of the lighting device.

The first lens130is, for example, a collimating lens. The first lens130is formed of a light transmissive material, such as acrylic, polycarbonate, or the like. The shape of the first lens130is convex projecting towards the front. The surfaces of the first lens130include a first incident face131, a first emission face132, and an upper face133.

The first incident face131is a flat face parallel to the up-down direction Z and the left-right direction Y. The first emission face132is located opposite the first incident face131. The first emission face132is curved in a convex shape projecting towards the front. The upper face133is located between the upper edge of the first incident face131and the upper edge of the first emission face132. The upper face133is a flat face parallel to the upper face191aof the substrate191.

As shown inFIG. 3, the second lens140is positioned higher than the first lens130in the up-down direction Z. In other words, the second lens140is disposed higher than the first lens130in the direction from the lower face191btoward the upper face191aof the substrate191. The second lens140, disposed in front of the upper portion of the reflector120, is positioned apart from the reflector120. The upper edge140aof the second lens140is positioned higher than the inner face121aof the main body121of the reflector120. The lower edge140bof the second lens140is positioned higher than the upper face of the light emission part110.

As shown inFIG. 7, the second lens140is, for example, a collimating lens. The second lens140has a convex shape projecting towards the front. The second lens140is formed of a light transmissive material, such as acrylic, polycarbonate, or the like. The surfaces of the second lens140include a second incident face141, a second emission face142, and a lower face143.

The second incident face141is a flat face parallel to the up-down direction Z and the left-right direction Y. The second emission face142is located opposite to the second incident face141. The second emission face142is curved in a convex shape projecting towards the front. The lower face143is located between the lower edge of the second incident face141and the lower edge of the second emission face142. The lower face143is a flat face parallel to the upper face191aof the substrate191.

As shown inFIG. 3, the distance E2between the light emission part110and the second incident face141in the front-back direction X is smaller than the distance E1between the light emission part110and the first incident face131in the front-back direction X. The distance from the center of the light emission part110to the second incident face141is smaller than the distance from the center of the light emission part110to the first incident face131.

The area of the first incident face131in this embodiment is larger than the area of the second incident face141. The magnitude relation between the area of the first incident face131and the area of the second incident face141is not limited to this. The dimension (thickness) of the second lens140in the front-back direction X, in this embodiment, is smaller than the dimension (thickness) of the first lens130in the front-back direction X, but the magnitude relation between the thicknesses of the first lens130and the second lens140is not limited to this.

A first light shielding member150is disposed between the first lens130and the second lens140. The first light shielding member150in this embodiment has light absorbing properties. In the description herein, “light absorption” means light reflectivity of less than 1% for the irradiated light. The first light shielding member150is preferably dark colored, more preferably black. The first light shielding member150can be formed of, for example, a resin material with a black coating applied to the surface. Alternatively, the first light shielding member150can be formed of a light-absorbing material such as carbon black. However, the first light shielding member150can have light reflectivity.

As shown inFIG. 7, the first light shielding member150in this embodiment has a main body151positioned between the first lens130and the second lens140, and a first attaching part152and a second attaching part153to be attached to the heatsink192.

The main body151has a plate-like shape. The surfaces of the main body151include an upper face151aand a lower face151b.The upper face151ais parallel to the upper face191aof the substrate191. The upper face151ais in contact with the lower face143of the second lens140. The lower face151bis located opposite the upper face151a.The lower face151bis in contact with the upper face133of the first lens130. The main body151covers the entire upper face133of the first lens130and the entire lower face143of the second lens140.

The first attaching part152includes a first extended portion152athat is connected to the main body151and extending to the right, a second extended portion152bthat is connected to the first extended portion152aand extending downwards, and a third extended portion152cthat is connected to the second extended portion152band extending to the right. The third extended portion152cis provided with a through hole152dpassing through the third extended portion152cin the up-down direction Z. As shown inFIG. 2, in the through hole152dand a hole192aof the heatsink192, a fastener such as a screw or rivet for fastening the first light shielding member150to the heatsink192will be provided.

As shown inFIG. 7, the second attaching part153has a first extended portion153athat is connected to the main body151and extends to the left, a second extended portion153bthat is connected to the first extended portion153aand extends downwards, and a third extended portion153cthat is connected to the second extended portion153band extends to the left. The third extended portion153cis provided with a through hole153dpassing through the third extended portion153cin the up-down direction Z. As shown inFIG. 2, in the through hole153dand a hole192aof the heatsink192, a fastener such as a screw or rivet for fastening the first light shielding member150to the heatsink192will be provided.

The construction of the first light shielding member150is not limited to what has been described above. For example, the first light shielding member150does not have to be in contact with the upper face133of the first lens130and the lower face143of the second lens140. Furthermore, the first light shielding member150does not have to be attached to the heatsink192.

The first lens130, the second lens140, and the first light shielding member150will be collectively referred to as a “lens unit U” below.

FIG. 8Ais a perspective view of a second light shielding member, a third light shielding member, and an actuator of the lighting device.

FIG. 8Bis a plan view of the second light shielding member, the third light shielding member, and the actuator when viewed in the direction from the front to the back.

FIG. 9Ais a plan view of the second light shielding member when viewed in the direction from the back to the front.

FIG. 9Bis a plan view of the third light shielding member when viewed in the direction from the back to the front.

The second light shielding member160is joined to the shaft183of the actuator180. The second light shielding member160in this embodiment has light absorbing properties. The second light shielding member160is preferably dark colored, more preferably black. The second light shielding member160can be formed of a resin material with a black coating applied to the surface. Alternatively, the second light shielding member160can be formed of a light-absorbing material, such as carbon black and the like. The second light shielding member160can have light reflectivity.

The second light shielding member160substantially has a plate-like shape and a through hole160apassing through the second light shielding member160in the front-back direction X. As shown inFIG. 3, the second light shielding member160positioned between the reflector120and the lens unit U in the light-shielded state shields a portion of the light La advancing from the reflector120towards the first incident face131of the first lens130while allowing another portion of the light La to pass through the through hole160a.

As shown inFIG. 9A, the second light shielding member160in this embodiment includes a joining part161joined to the shaft183of the actuator180, a cut-off line forming part162positioned under the joining part161in the light-shielded state, a first connecting part163connecting the joining part161and the left edge of the cut-off line forming part162, and a second connecting part164connecting the joining part161and the right edge of the cut-off line forming part162. The through hole160ais formed by the joining part161, the cut-off line forming part162, the first connecting part163, and the second connecting part164.

The joining part161is provided with a through hole161apassing through the joining part161in the front-back direction X. As shown inFIG. 3, the shaft183of the actuator180is placed through the through hole161a.

The cut-off line forming part162in the light-shielded state shields a portion of the light La advancing from the reflector120towards the first incident face131of the first lens130, thereby forming a cut-off line J (seeFIG. 13A) in a low beam light distribution pattern.

The “cut-off line J” means the upper light-dark boundary in the low beam light distribution pattern. The low beam light distribution pattern is desired to reduce irradiation of light against oncoming traffic so as not to dazzle oncoming drivers, while irradiating signs or pedestrians on the sidewalk to allow the driver to see the signs and the pedestrians on the sidewalk. Accordingly, in the case where left-hand traffic is practiced such as in Japan, formation of a cut-off line that rises to the left is desired. An example of the shape of a cut-off line forming part162corresponding to left-hand traffic will be explained below.

As shown inFIG. 9A, the cut-off line forming part162extends in the left-right direction Y in the light-shielded state. In the light-shielded state, the surfaces of the cut-off line forming part162include an upper face162aand a lower face162blocated opposite the upper face162a.

The lower face162bis parallel to the left-right direction Y in the light-shielded state. The upper face162aincludes a first region162s1, a second region162s2, a third region162s3, and a fourth region162s4. The first region162s1is in contact with the first connecting part163and oblique to the left-right direction Y so as to go down towards the right. The second region162s2is in contact with the right edge of the first region162s1. The second region162s2is oblique to the left-right direction Y so as to go down towards the right. The third region162s3is in contact with the right edge of the second region162s2. The third region162s3is parallel to the left-right direction Y. The fourth region162s4is in contact with the right edge of the third region162s3. The fourth region162s4is oblique to the left-right direction Y so as to go up towards the right. Accordingly, the upper face162ais provided with a stepped portion162cformed by the regions162s1,162s2,162s3, and162s4. In the case of right-hand traffic, formation of a cut-off line that rises to the right is required. Accordingly, the shape of the cut-off line forming part for right-hand traffic would be the horizontally reversed shape of the cut-off line forming part162for left-hand traffic.

A portion of the first connecting part163extends obliquely to the up-down direction Z so as to extend downwards towards the left in the light-shielded state. A portion of the second connecting part164extends obliquely to the up-down direction Z so as to extend downwards towards the right in the light-shielded state.

As shown inFIG. 3, the position of the second light shielding member160in the direction from the light emission part110to the first lens130is between the position of the light emission part110and the position of the first lens130. The position of the third light shielding member170in the direction from the light emission part110to the second lens140is between the position of the light emission part110and the position of the second lens140. As shown inFIG. 8A, the third light shielding member170is disposed in front of the second light shielding member160. The third light shielding member170is positioned apart from the second light shielding member160. In other words, as shown inFIG. 3, the distance E3between the light emission part110and the second light shielding member160in the front-back direction X is smaller than the distance E4between the light emission part110and the third light shielding member170in the front-back direction X. However, the position of the third light shielding member170in the front-back direction X can be made the same as the position of the second light shielding member160by integrating the third light shielding member170and the second light shielding member160, or adjusting the positional relationship between the lens unit U and the third and second light shielding members170and160.

The third light shielding member170in this embodiment has light absorbing properties. The third light shielding member170is preferably dark colored, more preferably black. The third light shielding member170can be formed of a resin material with a black coating applied to the surface, for example. Alternatively, the third light shielding member170can be formed of a light-absorbing material, such as carbon black and the like. The third light shielding member170can have light reflectivity.

FIG. 9Bis a plan view of the third light shielding member170when viewed in the direction from the back to the front.

The third light shielding member170has a plate-like shape. The third light shielding member170has a joining part171and a main body172. The joining part171is joined to the shaft183of the actuator180. The main body172is connected to the joining part171and covers the entire second incident face141.

The joining part171is provided with through holes171apassing through the joining part171in the front-back direction. In the through holes171a,fasteners such as screws or rivets will be provided to fasten the third light shielding member170to the shaft183of the actuator180.

As shown inFIG. 3, the main body172in the light-shielded state covers the entire second incident face141and shields the second portion L2of the light emitted from the light emission part110advancing towards the second incident face141. In the light-shielded state, the lower edge of the main body172is positioned higher than the upper face133of the first lens130. The lower edge of the main body172is positioned above the upper face162aof the cut-off line forming part162of the second light shielding member160.

The actuator180, as shown inFIG. 8A, includes a motor181, a holder182that holds the motor181, and a shaft183that is interlocked with the motor181. The holder182is provided with through holes182apassing through the holder182in the front-back direction X. The shaft183is located in front of the motor181, and extends in the front-back direction X. When the motor181is rotated, the shaft183rotates about the axis C2which extends in the front-back direction X. The rotation of the shaft183causes the second light shielding member160and the third light shielding member170to rotate about the axis C2.

As shown inFIG. 1, by actuating the motor181to thereby rotate the shaft183, the actuator180switches between the following states (i) and (ii):

(i) the light-shielded state, in which the second light shielding member160is positioned to shield a portion of the light L1aadvancing from the reflector120to the first incident face131, and the third light shielding member170is positioned to shield the light L2advancing from the light emission part110to the second incident face141, and

(ii) the non-light-shielded state, in which the second light shielding member160is positioned not to shield the light L1aadvancing from the reflector120towards the first incident face131, and the third light shielding member170is positioned not to shield the light L2advancing from the light emission part110towards the second incident face141.

The light emission part110and the actuator180are electrically connected to a controller193. The controller193, which is electrically connected to an integrated controller installed in a vehicle, controls the light emission part110and the actuator180in accordance with the control signals received from the integrated controller.

The controller193includes, for example, a control circuit for the light emission part110, a control circuit for the actuator180, a central processing unit (CPU), and an electronic control unit (ECU) including a memory. The controller193controls the light emitting element111in the light emission part110to turn on or off the light emitting element111. The controller193controls the motor181of the actuator180to switch between the light-shielded state and the non-light-shielded state.

The operation of a lighting device100according to the embodiment will be explained next.

FIG. 10is a diagram showing the paths of the light emitted from the light emission part in the light-shielded state.

FIG. 11is a diagram showing the paths of the light emitted from the light emission part in the non-light-shielded state.

FIG. 12Ais a diagram illustrating the light output by a vehicle in the light-shielded state.

FIG. 12Bis a diagram illustrating the light output by a vehicle in the non-light-shielded state.

FIG. 13Ais a diagram illustrating a light distribution pattern on a screen placed in front of a vehicle in the light-shielded state.

FIG. 13Bis a diagram illustrating a light distribution pattern on a screen placed in front of a vehicle in the non-light-shielded state.

InFIG. 13AandFIG. 13B, the HV point, the H line, and the V line on the screen S specified in the regulations such as the Headlight Test (Regulation No. 112 of the UN/ECE) for left-hand traffic enforced in countries such as Japan are denoted as HV, H, and V, respectively. InFIG. 12AtoFIG. 13B, moreover, the light irradiated regions are indicated by using dot patterns. InFIG. 12AtoFIG. 13B, dot patterns are varied to facilitate distinctions among the regions explained below. Accordingly, a dot pattern difference does not represent a luminous intensity difference.

When a control signal for outputting a low beam light distribution pattern is received from the integrated controller, as shown inFIG. 10, the controller193controls the actuator180to achieve the light-shielded state while turning on the light emission part110.

This lights up the light emission part110in the state in which the second light shielding member160and the third light shielding member170are positioned between the reflector120and the lens unit U. At this point, the first portion L1of the light emitted from the light emission part110is reflected by the reflector120. The light L1a, the vast majority of the first portion L1reflected by the reflector120, advances towards the first incident face131.

The cut-off line forming part162is positioned between the lower portion of the reflector120and the first incident face131of the first lens130. Accordingly, a portion L1bof the light L1aadvancing from the reflector120to the first incident face131is shielded by the cut-off line forming part162.

The through hole160ais positioned above the cut-off line forming part162and in front of the reflector120. Accordingly, a portion L1c, another portion of the light L1aadvancing from the reflector120towards the first incident face131, enters the first incident face131and exits the first emission face132. At this point, the first light shielding member150is provided between the first lens130and the second lens140in the up-down direction Z. Accordingly, the light having entered the first lens130is less likely to enter the second lens140. Also, direct light from the light emission part110is less likely to enter the second lens140through the lower face143of the second lens140. This can reduce stray light in the light-shielded state.

The light L1cthat has exited from the first emission face132, as shown inFIG. 12A, illuminates the region in front of the vehicle G having the lighting device100installed therein. As shown inFIG. 13A, the light L1cthat has exited the first emission face132primarily illuminates the first region S1positioned below the H line on the screen S. Because the portion L1bof the light L1ais shielded by the cut-ff line forming part162, a cut-off line J is formed on the upper end of the first region S1. The cut-off line J can hinder illuminating the region in the vicinity of the HV point and the region on the right side of the V line above the H line. In other words, irradiation of light against oncoming traffic can be hindered.

As shown inFIG. 10, the second portion L2of the light emitted from the light emission part110advances towards the second incident face141of the second lens140without being reflected by the reflector120. In the light-shielded state, the third light shielding member170covers the entire second incident face141. Accordingly, the second part L2is shielded by the third light shielding member170and substantially does not enter the second incident face141.

The distance E3between the light emission part110and the second light shielding member160in the front-back direction X is smaller than the distance E4between the light emission part110and the third light shielding member170in the front-back direction X. Accordingly, the light L1aadvancing from the reflector120to the first incident face131of the first lens130is less likely to be shielded by the third light shielding member170.

In this manner, in the light-shielded state, a light distribution pattern formed primarily by the light Lc that has exited form the first emission face132of the first lens130can be achieved.

When a control signal for outputting a high beam light distribution pattern is received from the integrated controller, as shown inFIG. 11, the controller193controls the actuator180to achieve the non-light-shielded state while turning on the light emission part110. This lights up the light emission part110in the state in which the second light shielding member160and the third light shielding member170are both entirely out of the positions between the reflector120and the lens unit U.

The first portion L1of the light emitted from the light emission part110is reflected by the reflector120. The light L1a, the vast majority of the first portion L1reflected by the reflector120, advances towards the first incident face131.

In the non-light-shielded state, as shown inFIG. 11, the cut-off line forming part162of the second light shielding member160is not positioned between the reflector120and the lens unit U. Accordingly, the portion L1bof the light L1athat would be shielded in the light-shielded state enters the first incident face131and exits from the first emission face132.

Similar to the light-shielded state, the portion L1c, another portion of the light L1aadvancing from the reflector120towards the first incident face131enters the first incident face131and exits from the first emission face132.

The light L1cthat has exited from the first emission face132, as shown inFIG. 12B, illuminates the region in front of the vehicle G. As a result, as shown inFIG. 13B, the light L1cprimarily illuminates the first region S1on the screen S located under the H line. The light L1bthat has exited from the first emission face132, as shown inFIG. 12B, illuminates the region in front of the vehicle G and above the region illuminated by the light L1c. As a result, as shown inFIG. 13B, the light L1bprimarily illuminates the second region S2on the screen S that is positioned above the first region S1and includes the HV point while spreading in the direction in which the H line extends. This allows the light to illuminate the region above the H line on the screen S as well as increasing the luminous intensity of the vicinity of the HV point.

As shown inFIG. 11, in the non-light-shielded state, the entire second incident face141is exposed from the third light shielding member170. Accordingly, the second portion L2of the light emitted from the light emission part110enters the second incident face141. The distance E2between the light emission part110and the second incident face141of the second lens140in the front-back direction X is smaller than the distance E1between the light emission part110and the first incident face131of the first lens130in the front-back direction. Accordingly, the light emitted from the light emission part110advancing upwards and forward can readily enter the second incident face141of the second lens140. This, as a result, can increase the light extraction efficiency of the second lens140.

The light L2a,the vast majority of the light L2that has entered the second incident face141exits from the second emission face142. The light L2athat has exited from the second emission face142, as shown inFIG. 12B, primarily illuminates the region in front of the vehicle G and above the region illuminated by the light L1c. As a result, as shown inFIG. 13B, the light L2aprimarily illuminates the third region S3on the screen S that includes the HV point and the vicinity. The lower portion of the third region S3overlaps a portion of the first region S1, and the upper portion of the third region S3overlaps a portion of the second region S2. The upper portion of the third region S3overlapping a portion of the second region S2in the vicinity of the HV point can increase the luminous intensity in the vicinity of the HV point.

Moreover, as shown inFIG. 11, furthermore, the first light shielding member150is provided between the first lens130and the second lens140in the up-down direction Z. Accordingly, the light L1band L1cthat has entered the first lens130is less likely to enter the second lens140. Also, the light L2that has entered the second lens140is less likely to enter the first lens130. This can reduce stray light in the non-light-shielded state.

As a result, in the non-light-shielded state, as shown inFIG. 13B, a light distribution pattern formed by the light existing from the first emission face132of the first lens130and the light existing from the second emission face142of the second lens140can be achieved.

In the light distribution pattern in the light-shielded state, irradiation of light to the HV point is hindered and the region primarily under the H line is illuminated, whereas in the light distribution pattern in the non-light-shielded state, the vicinity of the HV point and the region above the H line are also illuminated. Accordingly, the light distribution pattern in the light-shielded state can be used as the low beam light distribution pattern, and the light distribution pattern in the non-light-shielded state can be used as the high beam light distribution pattern.

The effect of the embodiment will be explained next.

The lighting device100according to this embodiment includes a light emission part110, a reflector120, a first lens130, a second lens140, a first light shielding member150, a second light shielding member160, a third light shielding member170, and an actuator180.

The reflector120is disposed above the light emission part110, and reflects a first portion L1of the light emitted from the light emission part110.

The first lens130has a first incident face131from which the light L1areflected by the reflector120enters.

The second lens140is disposed higher than the first lens130in the up-down direction Z. The second lens140has a second incident face141from which a second portion L2of the light emitted from the light emission part110enters. The distance E2between the light emission part110and the second incident face141in the horizontal direction is smaller than the distance E1between the emission face110and the first incident face131in the horizontal direction.

The first light shielding member150is disposed between the first lens130and the second lens140in the up-down direction Z.

The position of the second light shielding member160in the front-back direction X is between the position of the light emission part110and the position of the first lens130.

The position of the third light shielding member170in the front-back direction X is between the position of the light emission part110and the position of the second lens140.

The actuator180can switch between the light-shielded state and the non-light-shielded state by moving the second light shielding member160and the third light shielding member170.

In the light-shielded state, the second light shielding member160shields a portion of the light L1aadvancing from the reflector120to the first incident face131, and the third light shielding member170shields the second portion L2of the light advancing from the light emission part110to the second incident face141.

In the non-light-shielded state, the second light shielding member160does not shield the light L1aadvancing from the reflector120towards the first incident face131, and the third light shielding member170does not shield the second portion L2.

According to the lighting device100described above, switching between the low beam light distribution pattern and the high beam light distribution pattern can be achieved by using a single light emission part110.

In the lighting device100described above, moreover, the distance E2between the light emission part110and the second incident face141of the second lens140in the front-back direction X is smaller than the distance E1between the light emission part110and the first incident face131of the first lens130in the front-back direction. Accordingly, the light emitted by the light emission part110upwards and forward can readily enter the second incident face141of the second lens140. This, as a result, can increase the light extraction efficiency of the second lens140. This can increase the luminous intensity at the HV point and the vicinity thereof in the high beam light distribution pattern.

Furthermore, the first light shielding member150is provided between the first lens130and the second lens140in the up-down direction Z. Accordingly, in the light-shielded state, the light L1bthat has entered the first lens130is less likely to enter the second lens140, and direct light from the light emission part110is less likely to enter the second lens140from the lower face143of the second lens140. Furthermore, in the non-light-shielded state, the light L1band L1cthat has entered the first lens130is less likely to enter the second lens140, and the light L2athat has entered the second lens140is less likely to enter the first lens130. This can reduce stray light in both the light-shielded state and the non-light-shielded state.

In the light-shielded state, the distance E3between the light emission part110and the second light shielding member160in the horizontal direction is smaller than the distance E4between the light emission part110and the third light shielding member170in the horizontal direction. Accordingly, the third light shielding member170is less likely to shield the light L1aadvancing from the reflector120towards the first incident face131of the first lens130.

The first lens130has a first emission face132located opposite the first incident face131, and an upper face133located between the upper edge of the first incident face131and the upper edge of the first emission face132. The second lens140has a second emission face142located opposite the second incident face141, and a lower face143located between the lower edge of the second incident face141and the lower edge of the second emission face142. The first light shielding member150covers the upper face133and the lower face143. Accordingly, the light that has entered the first lens130is less likely to enter the second lens140, and the light that has entered the second lens140is less likely to enter the first lens130.

Moreover, the area of the first incident face131is larger than the area of the second incident face141. Accordingly, the first lens130can readily take in the light advancing from the reflector120.

The actuator180can switch between the light-shielded state and the non-light-shielded state by rotating the second light shielding member160and the third light shielding member170. This can achieve switch between the light-shielded state and the non-light-shielded state by a simple structure.

Furthermore, the first light shielding member150is a light absorbing material. It can thus reduce stray light.

In the embodiment described above, an example in which the actuator rotates the second light shielding member and the third light shielding member has been explained. However, the actuator can be designed to switch between the light-shielded state and the non-light-shielded state by moving the second and third light shielding members in the up-down direction or the left-right direction.

In the embodiment described above, moreover, an example in which the actuator rotates the second and third light shielding members in the same direction has been explained. However, the directions of rotation for the second and third light shielding members can be different from one another.