Patent Description:
As a vehicular headlamp, for example, a configuration in which a first light source for forming a low beam pattern in front of a vehicle and a second light source for forming a high beam pattern illuminating a distant area are installed in a single unit is known (see, for example, PTL1 and/or PTL2).

Vehicular headlamps described in PTL <NUM> and PTL <NUM> have configurations in which the first light source and the second light source are disposed on different planes. In this configuration, the number of components increases because separate mounting substrates need to be formed for the first and second light sources.

The present invention has been made in view of the above, and an object of the present invention is to provide a vehicular headlamp in which increase in the number of components can be suppressed.

A vehicular headlamp according to the present invention includes: a first light source that emits first light forward; a second light source that is disposed above the first light source and emits second light forward; a first reflecting surface that is disposed in front of the first light source, and reflects the first light upward; a second reflecting surface that is disposed above the second light source, and reflects, forward, the first light which reaches from the first light source via the first reflecting surface; a third reflecting surface that is disposed above the second light source and below the second reflecting surface in a state of extending in a front-rear direction, is connected to the second reflecting surface at an edge portion so as to share the edge portion with the second reflecting surface, and reflects the second light from the second light source forward; and a projection lens that is disposed in front of the first reflecting surface, the second reflecting surface, and the third reflecting surface, and irradiates the first light and the second light forward, and the first light source and the second light source are disposed on the same plane.

In the above vehicular headlamp, the edge portion may be disposed in a vicinity of a focal point of the projection lens, the second light source may be disposed below an optical axis of the projection lens and behind the focal point of the projection lens, and the first light source and the second light source may be disposed such that respective emission axes of the first light and the second light may face forward and diagonally upward.

The above vehicular headlamp may further include a substrate having a planar mounting surface mounted with the first light source and the second light source thereon, wherein the substrate may be disposed such that a normal line of the mounting surface face forward and diagonally upward.

In the above vehicular headlamp, the first reflecting surface, the second reflecting surface and the third reflecting surface may be formed on a surface of a single component.

In the above vehicular headlamp, the first light may be light for forming a low beam pattern in front of a vehicle, the second light may be light for forming a high beam pattern in front of the vehicle, and the edge portion may have a cutoff formation portion for forming a cutoff line in the low beam pattern.

According to the present invention, it is possible to provide a vehicular headlamp in which increase in the number of components can be suppressed.

Hereinafter, an embodiment of a vehicular headlamp according to the present invention will be described with reference to the drawings. The present invention is not limited by this embodiment. Components in the following embodiment include those that can be easily replaced by those skilled in the art, or those that are substantially the same.

<FIG> and <FIG> are diagrams illustrating an example of a vehicular headlamp <NUM> according to this embodiment. <FIG> is a front view illustrating an example of the vehicular headlamp <NUM>, and <FIG> is a sectional view taken along A-A arrows in <FIG>. As illustrated in <FIG> and <FIG>, the vehicular headlamp <NUM> includes a light source unit <NUM>, a reflector <NUM>, a projection lens <NUM>, and a holding portion <NUM>.

The light source unit <NUM> has first light sources <NUM>, second light sources <NUM>, and a substrate <NUM>. Each first light source <NUM> emits first light L1 for forming a low beam pattern in front of the vehicle, for example. The second light source <NUM> emits second light L2 for forming a high beam pattern in front of the vehicle, for example.

For the first light sources <NUM> and the second light sources <NUM>, for example, semiconductor-type light sources such as LEDs are used. A plurality of the first light sources <NUM> and a plurality of the second light sources <NUM> are provided, and are arranged side by side in the right-left direction. One of the first light sources <NUM> is disposed in the center in the right-left direction, and other first light sources <NUM> are disposed one by one on the both sides in the right-left direction, that is, three in total are disposed. The number of the first light sources <NUM> is not limited to three, but may be two or less or four or more. The plurality of second light sources <NUM> are disposed such that intervals between the second light sources <NUM> in the right-left direction are narrower than intervals between the first light sources <NUM>. The second light sources <NUM> may, for example, have independently controllable lighting conditions. The first light sources <NUM> are disposed below the second light sources <NUM>. In other words, the second light sources <NUM> are disposed above the first light sources <NUM>. Thus, the first light sources <NUM> and the second light sources <NUM> are disposed vertically.

The first light sources <NUM> and the second light sources <NUM> are mounted on a mounting surface 13a of the substrate <NUM>. In this embodiment, the first light sources <NUM> and the second light sources <NUM> are mounted on the single substrate <NUM>. Therefore, a separate substrate does not need to be formed for each light source, and it is possible to reduce the number of components. The mounting surface 13a is planar. The substrate <NUM> is disposed on a substrate support surface <NUM> (see <FIG>) of the holding portion <NUM> described below. The substrate <NUM> is disposed along the substrate support surface <NUM>. The substrate <NUM> is disposed with the mounting surface 13a facing forward and diagonally upward. The first light sources <NUM> and the second light sources <NUM> are disposed with light emitting surfaces 11a and light emitting surfaces 12a facing forward, more specifically, facing forward and diagonally upward. Therefore, the first light sources <NUM> and the second light sources <NUM> are arranged such that emission axes of the first light L1 and the second light L2 each face forward and diagonally upward.

The reflector <NUM> reflects the first light L1 from each first light source <NUM> and the second light L2 from each second light source <NUM> toward the projection lens <NUM>. As illustrated in <FIG>, the reflector <NUM> is provided as a single component and is fixed to the holding portion <NUM>. The fact that the reflector <NUM> is a single member enables the positions of first reflecting surfaces <NUM>, a second reflecting surface <NUM>, and a third reflecting surface <NUM>, described below, to be precisely defined.

<FIG> is an enlarged diagram illustrating a main part of <FIG>. As illustrated in <FIG> and <FIG>, the reflector <NUM> has the first reflecting surfaces <NUM>, the second reflecting surface <NUM>, and the third reflecting surface <NUM>.

The first reflecting surfaces <NUM> are disposed in front of the first light sources <NUM>. Each first reflecting surface <NUM> reflects the first light upward. Each first reflecting surface <NUM> has such a shape as to extend forward from the substrate <NUM> and be curved upward so as to be convex toward the front. The first reflecting surfaces <NUM> each consist of a free-form surface based on an ellipsoid or a paraboloid, for example. As illustrated in <FIG>, the first reflecting surface <NUM> is provided corresponding to the position of each first light source <NUM>. In this embodiment, one of the first reflecting surfaces <NUM> is disposed in the center in the right-left direction, and other first reflecting surfaces <NUM> are disposed one by one on the both sides in the right-left direction, that is, three in total are disposed. The first reflecting surface <NUM> is not limited to the configuration in which the first reflecting surface <NUM> is provided corresponding to the position of each first light source <NUM>.

The second reflecting surface <NUM> is disposed above the second light sources <NUM>. The first light which reaches from each first light source <NUM> through the corresponding first reflecting surface <NUM> is reflected forward. The second reflecting surface <NUM> has a curved shape that is convex on the upper side. The second reflecting surface <NUM> consists of a free-form surface based on an ellipsoid, a paraboloid, or a plane, for example. The curvature of the second reflecting surface <NUM> may be the same as or different from that of each first reflecting surface <NUM>.

The second reflecting surface <NUM> forms an edge portion <NUM> at a rear end. The edge portion <NUM> is shared with the third reflecting surface <NUM>, described below. As illustrated in <FIG>, the edge portion <NUM> has a first straight portion 24a, an oblique portion 24b, and a second straight portion 24c. The first straight portion 24a and the second straight portion 24c are used to form horizontal cutoff lines CLa and CLc (see <FIG>) of the low beam pattern. The oblique portion 24b is used to form an oblique cutoff line CLb (see <FIG>) of the low beam pattern. The edge portion <NUM> is disposed at a focal point F of the projection lens <NUM> or in the vicinity of the focal point F, as described below. The first straight portion 24a and the second straight portion 24c may have a curved shape along an image plane by the projection lens <NUM>.

The third reflecting surface <NUM> is disposed above the second light source <NUM> and below the second reflecting surface <NUM>. The third reflecting surface <NUM> is disposed downward. The third reflecting surface <NUM> reflects, forward, a portion of the second light emitted from each second light source <NUM>, for example, an upward component of the second light from each second light source <NUM>. The third reflecting surface <NUM> shares the edge portion <NUM> with the second reflecting surface <NUM> and is connected to the second reflecting surface <NUM> at the edge portion <NUM>. The third reflecting surface <NUM> extends from the edge portion <NUM> toward the substrate <NUM>, that is, rearward in the front-rear direction. The third reflecting surface <NUM> is disposed in the vicinity of the second light sources <NUM>.

The projection lens <NUM> is disposed in front of the reflector <NUM>. The projection lens <NUM> has an incident surface <NUM> and an emission surface <NUM>. On the incident surface <NUM>, the first light L1 and the second light L2 from the reflector <NUM> are incident. The emission surface <NUM> emits the first light L1 and the second light L2 incident on the incident surface <NUM> to the front of the vehicle to form a low beam pattern and a high beam pattern. The projection lens <NUM> may be provided with a light diffusion portion (not illustrated) on at least one of the incident surface <NUM> and the emission surface <NUM>. This light diffusion portion diffuses the light incident on the incident surface <NUM> and the light emitted from the emission surface <NUM> in the right-left direction or the vertical direction.

The holding portion <NUM> has the substrate support surface <NUM> that supports the substrate <NUM>, at the front. The substrate support surface <NUM> is planar, for example, and is disposed facing forward and diagonally upward. The holding portion <NUM> dissipates heat generated by the first light sources <NUM> and the second light sources <NUM>. The holding portion <NUM> may be provided with a heat dissipating part (not illustrated) such as fins at the rear, the top or the bottom.

Now, operation of the vehicular headlamp <NUM> configured as described above will be described. <FIG> is a diagram illustrating an example of the operation of the vehicular headlamp <NUM>. The first light sources <NUM> of the vehicular headlamp <NUM> are turned on, so that the first light L1 is emitted from the light emitting surfaces 11a. As illustrated in <FIG>, the first light L1 is reflected upward by each first reflecting surface <NUM>, reflected forward by the second reflecting surface <NUM>, and reaches the projection lens <NUM>. The first light L1 that reaches the projection lens <NUM> is irradiated to the front of the vehicle by the projection lens <NUM>.

<FIG> is a diagram illustrating an example of a light distribution pattern PF irradiated on a virtual screen in front of the vehicle, and illustrates a pattern corresponding to a vehicle which drives on the left side of a road. In <FIG>, a V-V line indicates a vertical line of the screen and an H-H line indicates a right-left horizontal line on the screen. Herein, an intersection of the vertical line and the horizontal line is assumed to be a reference position in the horizontal direction.

As illustrated in <FIG>, the first light L1 emitted from the projection lens <NUM> forms a low beam pattern P1 in front of the vehicle. A cutoff line CL is formed by light that passes through the edge portion <NUM> of the first light L1. The cutoff line CL includes the horizontal cutoff lines CLa and CLc, and the oblique cutoff line CLb.

The second light sources <NUM> of the vehicular headlamp <NUM> are turned on, so that the second light L2 is emitted from the light emitting surfaces 12a. As illustrated in <FIG>, a portion of the second light L2, which is emitted forward (hereafter referred to as second light L2a), passes below the third reflecting surface <NUM> and reaches the projection lens <NUM>. In this case, a portion of the second light L2a reaches the projection lens <NUM> beyond the vicinity of the edge portion <NUM> which is a tip of the third reflecting surface <NUM>. A portion of the second light L2, which is emitted upward (hereinafter referred to as second light L2b), is reflected forward by the third reflecting surface <NUM> and reaches the projection lens <NUM>. A portion of the second light L2, which is emitted downward (hereinafter referred to as the second light L2c), passes through information on the first reflecting surface <NUM> and reaches the projection lens <NUM>.

The second light L2a, the second light L2b, and the second light L2c that reach the projection lens <NUM> are irradiated to the front of the vehicle by the projection lens <NUM>, and form a high beam pattern P2, as illustrated in <FIG>. The second light L2c that reaches the lower side of the projection lens <NUM> is irradiated on an upper part of the high beam pattern P2.

In this embodiment, the first light sources <NUM> and the second light sources <NUM> are arranged such that the emission axes of the first light L1 and the second light L2 face forward and diagonally upward. Therefore, each first light source <NUM> can be arranged such that the first light L1 passes through the edge portion <NUM> of the second reflecting surface <NUM>, while each second light source <NUM> can be arranged such that the emission axis of the second light L2 is directed toward the vicinity of the edge portion <NUM>. With this configuration, a portion of the second light L2a passes near the edge portion <NUM> and reaches the projection lens <NUM>. Therefore, a lower portion of the high beam pattern P2 is formed near the horizontal cutoff line CLc of the low beam pattern P1. Therefore, the high beam pattern P2 can be prevented from being formed above and away from the low beam pattern P1. In addition, the low beam pattern P1 and the high beam pattern P2 can be partially overlapped to increase the altitude in the center.

As described above, the vehicular headlamp <NUM> according to this embodiment includes: the first light sources <NUM> that emit the first light L1 forward; the second light sources <NUM> that are disposed above the first light sources <NUM> and emit the second light L2 forward; the first reflecting surfaces <NUM> that are disposed in front of the first light sources <NUM>, and reflect the first light L1 upward; the second reflecting surface <NUM> that is disposed above the second light sources <NUM>, and reflects, forward, the first light L1 which reaches from the first light sources <NUM> via the first reflecting surfaces <NUM>; the third reflecting surface <NUM> that is disposed above the second light sources <NUM> and below the second reflecting surface <NUM> in a state of extending in the front-rear direction, is connected to the second reflecting surface <NUM> at an edge portion <NUM> so as to share the edge portion <NUM> with the second reflecting surface <NUM>, and reflects the second light L2 from the second light sources <NUM> forward; and the projection lens <NUM> that is disposed in front of the first reflecting surfaces <NUM>, the second reflecting surface <NUM>, and the third reflecting surface <NUM>, and irradiates the first light L1 and the second light L2 forward, and the first light sources <NUM> and the second light sources <NUM> are disposed on the same plane, and the second light sources <NUM> are disposed below the optical axis AX of the projection lens <NUM>.

According to this configuration, the first light sources <NUM> and the second light sources <NUM> are disposed on the same plane, and therefore the first light sources <NUM> and the second light sources <NUM> can be mounted on the single substrate <NUM>. Therefore, a separate substrate does not need to be formed for each light source. Consequently, it is possible to prevent suppress in the number of components. In addition, the second light L2 which travels upward from the second light sources <NUM> is reflected forward by the third reflecting surface <NUM>, and therefore it is possible to suppress the loss of the second light L2. Further, the first light sources <NUM> and the second light sources <NUM> are disposed vertically and face forward, so that it is possible to reduce the size in the front-rear direction compared to a case where the first light sources <NUM> and the second light sources <NUM> are directed vertically.

In the vehicular headlamp <NUM> according to this embodiment, the edge portion <NUM> is disposed in the vicinity of the focal point of the projection lens <NUM>, the second light sources <NUM> are disposed below the optical axis AX of the projection lens <NUM> and behind the focal point F of the projection lens <NUM>, and the first light sources <NUM> and the second light sources <NUM> are disposed such that respective emission axes of the first light L1 and the second light L2 face forward and diagonally upward. According to this configuration, the first light sources <NUM> can be arranged such that the first light L1 passes through the edge portion <NUM> of the second reflecting surface <NUM>, while the second light sources <NUM> can be arranged such that the emission axis of the second light L2 is directed toward the vicinity of the edge portion <NUM>. Consequently, a portion of the second light L2 passes through the vicinity of the edge portion <NUM> to reach the projection lens <NUM>, and therefore the pattern by the second light L2 can be formed in the vicinity of the upper side of the pattern by the first light L1.

The vehicular headlamp <NUM> according to this embodiment further includes the substrate <NUM> having the planar mounting surface 13a mounted with the first light sources <NUM> and the second light sources <NUM> thereon, wherein the substrate <NUM> is disposed such that a normal line of the mounting surface 13a face forward and diagonally upward. According to this configuration, it is possible to set the orientation and the position of each of the first light sources <NUM> and the second light sources <NUM> with high precision.

In the vehicular headlamp <NUM> according to this embodiment, the first reflecting surfaces <NUM>, the second reflecting surface <NUM>, and the third reflecting surface <NUM> are formed on a surface of a single component. In this configuration, the positional relation among the first reflecting surfaces <NUM>, the second reflecting surface <NUM>, and the third reflecting surface <NUM> can be precisely defined compared to a configuration in which the first reflecting surfaces <NUM>, the second reflecting surface <NUM>, and the third reflecting surface <NUM> are formed in separate components.

In the vehicular headlamp <NUM> according to this embodiment, the first light L1 is light for forming the low beam pattern P1 in front of a vehicle, the second light L2 is light for forming the high beam pattern P2 in front of the vehicle, and the edge portion <NUM> has a cutoff formation portion (the first straight portion 24a, the oblique portion 24b, the second straight portion 24c) for forming a cutoff line CL in the low beam pattern P1. In this configuration, the lower portion of the high beam pattern P2 is formed in the vicinity of the horizontal cutoff line CLc of the low beam pattern P1. Consequently, the high beam pattern P2 can be prevented from being formed above and away from the low beam pattern P1.

The technical scope of the present invention is not limited to the above embodiment, and modifications can be made as appropriate without departing from the scope of the present invention, which is defined in the appended claims.

For example, the first reflecting surfaces <NUM>, the second reflecting surface <NUM>, and the third reflecting surface <NUM> are formed on the surface of the single component in the above embodiment. However, the present invention is not limited to this. At least one of the first reflecting surfaces <NUM>, the second reflecting surface <NUM>, and the third reflecting surface <NUM> may be formed on a separate component.

In the above embodiment, the first light sources <NUM> and the second light sources <NUM> are arranged such that the respective emission axes of the first light L1 and the second light L2 face forward and diagonally upward. However, the present invention is not limited to this. The first light sources <NUM> and the second light sources <NUM> may be arranged such that the respective emission axes of the first light L1 and the second light L2 are directed to the direction along a front horizontal surface or forward and diagonally downward.

Claim 1:
A vehicular headlamp comprising:
a first light source (<NUM>) that emits first light (L1) forward;
a second light source (<NUM>) that is disposed above the first light source (<NUM>) and emits second light (L2) forward;
a first reflecting surface (<NUM>) that is disposed in front of the first light source (<NUM>), and reflects the first light (L1) upward;
a second reflecting surface (<NUM>) that is disposed above the second light source (<NUM>), and reflects, forward, the first light (L1) which reaches from the first light source (<NUM>) via the first reflecting surface (<NUM>);
a third reflecting surface (<NUM>) that is disposed above the second light source (<NUM>) and below the second reflecting surface (<NUM>) in a state of extending in a front-rear direction, is connected to the second reflecting surface (<NUM>) at an edge portion (<NUM>) so as to share the edge portion (<NUM>) with the second reflecting surface (<NUM>), and reflects the second light (L2) from the second light source (<NUM>) forward; and
a projection lens (<NUM>) that is disposed in front of the first reflecting surface (<NUM>), the second reflecting surface (<NUM>), and the third reflecting surface (<NUM>), and irradiates the first light (L1) and the second light (L2) forward, wherein
the first light source (<NUM>) and the second light source (<NUM>) are disposed on the same plane.