JP2014107049A - Head light for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a head light for a vehicle capable of forming a light distribution pattern with high visibility.SOLUTION: A head light for a vehicle comprises: a projection lens 20; a first optical system 21 having a first reflector 32 for reflecting light from a first light source 31 near an optical axis Ax; a second optical system 22 having a second reflector 36 for reflecting light from a second light source 35 near the optical axis Ax; and a transparent member 23 arranged near a rear focal point f of the projection lens 20. The light from the first optical system 21 passes through the transparent member 23, and is emitted to a front of a lamp from the projection lens 20, so as to form a low beam light distribution pattern. The light from the second optical system forms a high beam light distribution pattern. The transparent member 23 is provided with a first total reflection face 25a for passing the light from the second optical system 22 and total-reflecting some of the light of the first optical system 21. One part of a ridge line 23a that is an edge of the first total reflection face 25a has a shape corresponding to a cut-off line.

Description

  The present invention relates to a vehicle headlamp that illuminates the front of a vehicle.

  A vehicle headlamp capable of forming a low beam light distribution pattern and a high beam light distribution pattern using a common projection lens is known in Patent Document 1 and the like. In the vehicle headlamp described in Patent Document 1, a low beam light distribution pattern is formed by turning on the first light source system, and a high beam light distribution pattern is formed by turning on the first light source system and the second light source system. doing.

Japanese Patent No. 4413762

  In the vehicle headlamp described in Patent Literature 1, the first mirror member has an upward reflecting surface formed by aluminum vapor deposition. This upward reflecting surface reflects a part of the light from the first light emitting element of the first light source system to form a cut-off line of the low beam light distribution pattern.

  However, when the high beam light distribution pattern is formed, the first mirror member has a certain thickness, so that this portion is projected in front of the lamp, and a dark portion corresponding to the thickness is formed. Therefore, when the high beam light distribution pattern is formed, a dark part is formed in front of the lamp, and the driver's visibility may be reduced.

  Therefore, the present invention provides a vehicle headlamp capable of forming a light distribution pattern with high visibility.

The vehicle headlamp of the present invention capable of solving the above-described problems is
A projection lens having an optical axis extending in the front-rear direction;
A first optical system comprising: a first light source; and a first reflector that reflects light from the first light source from the optical axis;
A second optical system comprising: a second light source; and a second reflector that reflects light from the second light source from the optical axis;
A transparent member disposed in the vicinity of the rear focal point of the projection lens,
The light from the first optical system passes through the transparent member and is emitted from the projection lens to the front of the lamp to form a low beam light distribution pattern.
The light from the second optical system forms a high beam light distribution pattern together with the light from the first optical system,
The transparent member includes a total reflection surface that transmits light from the second optical system and totally reflects a part of the light from the first optical system,
A part of the edge of the total reflection surface has a shape corresponding to the cut-off line.

  In the vehicle headlamp according to the present invention, the transparent member transmits the light from the first optical system and totally reflects a part of the light from the second optical system toward the projection lens. It is preferable to have.

  According to the vehicle headlamp of the present invention, since the total reflection surface transmits the light from the second optical system, the irradiation range of the light from the first optical system and the second optical system are formed when the high beam light distribution pattern is formed. There is no gap between the areas irradiated by light from the system. Therefore, a highly visible light distribution pattern can be formed.

It is sectional drawing of the vehicle headlamp which concerns on 1st Embodiment of this invention. It is a schematic sectional drawing of the vehicle headlamp which shows the path | route of the light from a 1st optical system. It is a schematic sectional drawing of the vehicle headlamp which shows the path | route of the light from a 2nd optical system. It is a schematic diagram which shows the irradiation area | region by the vehicle headlamp. It is a figure explaining the vehicle headlamp which concerns on 2nd Embodiment of this invention, Comprising: (a) is a schematic sectional drawing in the back focus vicinity, (b) is a schematic diagram which shows an irradiation area | region.

  Hereinafter, a preferred embodiment of a vehicle headlamp according to the present invention will be described in detail with reference to the drawings.

(First embodiment)
First, the vehicle headlamp according to the first embodiment will be described.
FIG. 1 is a cross-sectional view of a vehicle headlamp according to a first embodiment of the present invention.
As shown in FIG. 1, the vehicle headlamp 10 according to the first embodiment includes a lamp body 11 having a front opening, and a light-transmitting outer cover 12 attached so as to cover the opening of the lamp body 11. I have. The vehicle headlamp 10 is a headlamp that is mounted on the front of the vehicle and illuminates the front of the vehicle.

  In this example, the front is the outer cover 12 side (left direction in FIG. 1) of the vehicle headlamp 10, and the rear is the lamp body 11 side (right direction in FIG. 1) opposite to the front. is there.

  The outer cover 12 is attached to the lamp body 11 by being adhesively fixed. The outer cover 12 is attached to the lamp body 11, and a sealed lamp chamber S is formed inside the vehicle headlamp 10.

  The vehicle headlamp 10 includes a projection lens 20, a first optical system 21, a second optical system 22, and a transparent member 23 in the lamp chamber S. The projection lens 20 has an optical axis Ax in the vehicle front-rear direction. A transparent member 23, a first optical system 21, and a second optical system 22 are arranged behind the projection lens 20.

  The projection lens 20 includes a planar incident surface 20a located on the rear side and a convex lens surface 20b located on the front side. The projection lens 20 condenses the light incident from the incident surface 20a and emits it from the lens surface 20b.

  A first support plate 27 is supported on the rear plate 11 a of the lamp body 11 so as to be tiltable by a plurality of bolts 25. By adjusting the fastening position with the rear plate 11a of the bolt 25, the orientations of the optical axes of the first optical system 21 and the second optical system 22 described later can be adjusted.

  A second support plate 28 is formed integrally with the first support plate 27. The second support plate 28 is a member that extends horizontally along the optical axis Ax in the vehicle longitudinal direction, and is disposed between the first optical system 21 and the second optical system 22. The first support plate 27 is provided with heat radiating fins 29 on the rear plate 11a side of the lamp body 11 for releasing heat from a first light source 31 and a second light source 35 described later.

  The first optical system 21 is an optical system that forms a lower irradiation region Lp serving as a low beam light distribution pattern. The first optical system 21 includes a first light source 31 and a first reflector 32. The first light source 31 is an LED (Light Emitting Diode) in the present embodiment, and is fixed to the upper surface of the second support plate 28 and emits light substantially upward.

  The first reflector 32 has an inner reflection surface made of a free-form surface based on an ellipse. The first reflector 32 reflects the light from the first light source 31 forward toward the optical axis Ax and converges it in the vicinity of the rear focal point f of the projection lens 20.

  The second optical system 22 is a light source unit that forms an upper irradiation region Hp described later, and includes a second light source 35 and a second reflector 36. The second optical system 22 can form an irradiation region including a cut-off line of the low beam distribution pattern by the first optical system 21. When the first optical system 21 is turned on together with the second optical system 22, a high beam light distribution pattern can be formed.

  The second light source 35 is also composed of an LED (Light Emitting Diode), and is fixed to the lower surface of the second support plate 28 and emits light substantially downward. The second reflector 36 has an inner surface formed of a free curved surface based on an ellipse. The second reflector 36 reflects the light from the second light source 35 toward the front toward the optical axis Ax and converges it in the vicinity of the rear focal point f of the projection lens 20.

  The second light source 35 constituting the second optical system 22 is arranged on the rear side of the first light source 31 constituting the first optical system 21. Thus, by arranging the first light source 31 and the second light source 35 at different positions in the front-rear direction, the heat generated by the first light source 31 and the second light source 35 is less likely to be accumulated, Adverse effects can be suppressed. With the arrangement of the first light source 31 and the second light source 35, the second reflector 36 constituting the second optical system 22 is arranged behind the first reflector 32 constituting the first optical system 21. Has been.

  Note that the first support plate 27 on which the second support plate 28 is formed can adjust the orientation of the surface of the first support plate in the vertical and horizontal directions by adjusting the screwing amount of the plurality of bolts 25. Then, by adjusting the direction of the first support plate 27, the direction of the optical axes of the first optical system 21 and the second optical system 22 mounted on the second support plate 28 can be adjusted.

  The transparent member 23 is disposed in the vicinity of the rear focal point f of the projection lens 20. The transparent member 23 is formed of a light-transmitting material such as a transparent resin such as acrylic or transparent glass, and transmits at least part of light from the first light source 31 and the second light source 35.

  Specifically, the transparent member 23 is formed of a prism having a quadrangular prism and has a rhombic cross section as shown in the drawing. In this embodiment, the attitude | position of the transparent member 23 is set so that two diagonal lines of a cross-sectional rhombus may face a horizontal direction and a perpendicular direction, respectively. In addition, among the diagonal lines having a rhombus cross section, the diagonal line facing in the horizontal direction is aligned with the optical axis Ax. Further, the posture of the transparent member 23 is set so that the ridge line 23a on the front side is positioned in the vicinity of the rear focal point f of the projection lens 20.

  Of the outer peripheral surface of the transparent member 23, the surface on the rear side and above the optical axis Ax is the first incident surface 24a, and the surface on the rear side and below the optical axis Ax is the second incident surface 24b. Yes. Of the transparent member 23, the front side and the lower side of the optical axis Ax is the first total reflection surface (total reflection surface) 25a, and the front side and the upper side of the optical axis Ax is the second total reflection surface. (Auxiliary reflection surface) 25b.

  In the transparent member 23, at least a part of a ridge line (edge) 23a formed by the first total reflection surface 25a and the second total reflection surface 25b has a stepped shape on the left and right, and a cut-off line of a low beam light distribution pattern. It is the shape corresponding to.

  Next, the path of light from the first optical system 21 and the second optical system 22 in the vehicle headlamp 10 having the above structure will be described with reference to FIGS. FIG. 2 is a schematic cross-sectional view of the vehicular headlamp 10 and shows a light path from the first optical system 21. FIG. 3 is a schematic cross-sectional view of the vehicle headlamp, and shows a light path from the second optical system 22. FIG. 4 is a schematic diagram of a light distribution pattern formed by the vehicle headlamp 10.

(First optical system)
As shown in FIG. 2, the light from the first light source 31 of the first optical system 21 is reflected near the optical axis Ax by the first reflector 32 and converges in the vicinity of the rear focal point f of the projection lens 20. The lower irradiation region Lp shown in FIG. 4 is formed by the light from the first optical system 21.

  As shown in FIG. 2, among the light from the first optical system 21, the light L1 that has passed through the rear focal point f of the projection lens 20 and passed above the optical axis Ax in the plane P perpendicular to the optical axis Ax is Directly enters the projection lens 20 or enters the projection lens 20 via the transparent member 23. The light L1 incident on the projection lens 20 is refracted by the projection lens 20 and emitted to the front of the lamp. As shown in FIG. 4, the light L1 reaches a region p1 below the lower irradiation region Lp.

  Returning to FIG. 2, the light L <b> 2 that attempts to pass below the optical axis Ax on the plane P enters the transparent member 23 from the first incident surface 24 a of the transparent member 23. The light L2 incident on the transparent member 23 is totally reflected by the first total reflection surface 25a, guided to the projection lens 20, refracted by the projection lens 20, and emitted forward of the lamp. As shown in FIG. 4, the light L2 reaches a region p2 above the lower irradiation region Lp.

  The first total reflection surface 25a is a surface using the total reflection phenomenon. Total reflection is a phenomenon in which light incident at a specific incident angle or more is totally reflected at an interface between substances having different refractive indexes without passing through the interface. In the present embodiment, the refractive index of the transparent member 23 and the first total reflection are reflected so as to reflect all the light L2 that attempts to pass below the optical axis Ax in the plane P among the light from the first optical system 21. An inclination angle of the surface 25a with respect to the optical axis Ax is determined.

  Note that the light that attempts to pass below the optical axis Ax in the plane P is light that is directly incident on the projection lens 20 if the transparent member 23 is not provided. When there is no transparent member 23, the light L2 'is refracted by the projection lens 20 and emitted upward in front of the lamp (see the dotted line L2' in FIG. 2).

  As shown in FIG. 4, when the first light source 31 of the first optical system 21 is turned on, the lower irradiation region Lp is formed by the lights L1 and L2. This lower irradiation region Lp becomes a low beam light distribution pattern.

  Here, the ridge line 23a of the transparent member 23 has a left-right step shape corresponding to the cut-off line CL of the low beam light distribution pattern. Therefore, a part of the light from the first light source 31 is blocked by the first total reflection surface 25a below the ridge line 23a, thereby forming a cut-off line CL of the low beam light distribution pattern. In this way, the light from the first optical system 21 is emitted forward of the lamp through the transparent member 23 and the projection lens 20 to form a low beam light distribution pattern.

(Second optical system)
As shown in FIG. 3, the light from the second light source 35 of the second optical system 22 is reflected near the optical axis Ax by the second reflector 36 and converges in the vicinity of the rear focal point f of the projection lens 20. The upper irradiation region Hp shown in FIG. 4 is formed by the light from the second optical system 22.

  As shown in FIG. 3, among the light from the second optical system 22, the light L <b> 3 that has passed below the optical axis Ax in the plane P is guided to the projection lens 20 directly or via the transparent member 23. The light is refracted by the projection lens 20 and emitted to the front of the lamp. As shown in FIG. 4, the light L3 reaches the region p3 above the upper irradiation region Hp.

Returning to FIG. 3, of the light from the second optical system 22, the light L <b> 4 that attempts to pass above the optical axis Ax in the plane P is incident from the second incident surface 24 b of the transparent member 23. The light L4 incident on the transparent member 23 from the second incident surface 24b is totally reflected toward the projection lens 20 by the second total reflection surface 25b. The light L4 is further refracted by the projection lens 20 and emitted to the front of the lamp. As shown in FIG. 4, the light L4 reaches a region p4 below the upper irradiation region Hp.
If there is no transparent member 23, the light L4 is light that directly enters the projection lens 20, is refracted by the projection lens 20, and is emitted upward (see the dotted line L4 ′ in FIG. 3).

  Here, the second total reflection surface 25b is also a reflection surface using the total reflection phenomenon as in the first total reflection surface 25a described above. Of the light from the second optical system 22, the refractive index of the transparent member 23 and the optical axis Ax of the second total reflection surface 25b are reflected so as to reflect all of the light L4 that attempts to pass above the optical axis Ax on the plane P. An inclination angle with respect to is determined.

  As shown in FIG. 4, when the second light source 35 of the second optical system 22 is turned on, an upper irradiation region Hp is formed by the lights L3 and L4. At this time, since the light L4 from the second optical system 22 is totally reflected toward the projection lens 20 by the second total reflection surface 25b of the transparent member 23, the upper irradiation region Hp is brightly formed. That is, by providing the second total reflection surface 25b, the light L4 ′ that should have been originally directed downward can be changed to the light L4 that is directed upward, and the upper irradiation region Hp can be brightly formed.

  In the vehicle headlamp 10 according to the present embodiment having the above-described configuration, only the first optical system 21 is turned on when a low beam distribution pattern is irradiated forward of the vehicle. When only the first optical system 21 is turned on, as shown in FIG. 4, a lower irradiation region Lp that is a low beam light distribution pattern is formed.

  Further, when the high beam light distribution pattern is irradiated forward of the vehicle, the first optical system 21 and the second optical system 22 are turned on. As described above, when the first optical system 21 and the second optical system 22 are turned on, in addition to the lower irradiation region Lp, the upper side is above the cut-off line CL of the low beam distribution pattern of the lower irradiation region Lp. An irradiation region Hp is formed, and a high beam light distribution pattern in which the lower irradiation region Lp and the upper irradiation region Hp are combined is formed.

  Here, the first total reflection surface 25a and the second total reflection surface 25b are reflection surfaces formed by utilizing the phenomenon of total reflection. As described above, the first total reflection surface 25a and the second total reflection surface 25b are formed by setting the refractive index of the transparent member and the incident angle with respect to the total reflection surfaces 25a and 25b so as to cause total reflection. . That is, since the first total reflection surface 25a and the second total reflection surface 25b are not physical reflection surfaces such as a vapor deposition surface, the first total reflection surface 25a and the second total reflection surface 25b do not have a thickness.

  Thus, the first total reflection surface 25a of the transparent member 23, which is a member that forms the cut-off line of the low beam light distribution pattern, has no thickness. Therefore, when the high beam distribution pattern is formed, the first total reflection surface 25a does not block the light from the second optical system 22, so that a dark gap is formed between the lower irradiation region Lp and the upper irradiation region Hp. It will not be done. Thereby, the lower irradiation region Lp formed by the light from the first optical system 21 and the upper irradiation region Hp formed by the light from the second optical system 22 are smoothly connected.

  As described above, according to the vehicle headlamp 10 according to the present embodiment, the first total reflection surface 25a transmits the light from the second optical system 22, and thus the low beam distribution emitted by the first optical system 21. A dark gap is not formed between the lower irradiation region Lp serving as a pattern and the upper irradiation region Hp irradiated by the second optical system 22. Therefore, a high beam light distribution pattern with high visibility and good appearance can be formed.

  Further, the transparent member 23 has a second total reflection surface 25 b that transmits light from the first optical system 21 and totally reflects a part of the light from the second optical system 22 toward the projection lens 20. Thereby, the light from the second optical system 22 can be used for forming the upper irradiation region Hp without waste, and the upper illumination region Hp can be formed brightly.

(Second Embodiment)
Next, the vehicle headlamp according to the second embodiment will be described.
FIG. 5 is a diagram illustrating a vehicle headlamp according to a second embodiment of the present invention. FIG. 5A is a schematic cross-sectional view in the vicinity of the rear focal point, and FIG. 5B is a schematic diagram showing an irradiation region.

  As shown in FIG. 5A, in the vehicle headlamp 40 according to the second embodiment, a tapered transparent member 41 is provided on the upper surface side at the front end of the second support plate 28. The transparent member 41 is also a shade having a shape corresponding to a cut-off line in which a ridge line 41a located on the front side on the projection lens 20 side forms a light distribution pattern having different steps on the left and right.

  The lower surface 41b of the transparent member 41 is a total reflection surface using a total reflection phenomenon. For this reason, of the light from the first optical system 21, the light that attempts to pass below the optical axis Ax on the plane P is totally reflected toward the projection lens 20 by the lower surface 41 b. Thus, the lower surface 41b of the transparent member 41 blocks part of the light from the first optical system 21, thereby forming a cut-off line of the low beam light distribution pattern.

  Further, the front end surface 28a of the second support plate 28 that supports the first light source 31 and the second light source 35 is an inclined surface that is inclined so that the lower end is positioned rearward of the upper end. The front end surface 28a and the upper surface 28b of the second support plate 28 are reflective surfaces on which aluminum or the like is deposited. In the vehicle headlamp 40, the second reflector 36 constituting the second optical system 22 is disposed on the front side of the second light source 35 and the front end face 28 a of the second support plate 28.

  In the vehicle headlamp 40, when the second light source 35 of the second optical system 22 is turned on, the light is reflected by the second reflector 36 toward the front end face 28a of the second support plate 28. Further, the light reflected by the front end face 28 a is irradiated forward of the lamp through the projection lens 20. Thereby, as shown to (b) of FIG. 5, the upper side irradiation area | region Hp is formed.

  Here, of the light from the second optical system 22, the light L5 reflected by the region below the front end face 28a is directly incident on the projection lens 20, refracted by the projection lens 20, and emitted upward. The Thereby, the light L5 irradiates near the center of the upper irradiation region Hp shown in FIG.

  Of the light from the second optical system 22, the light L 6 reflected by the intermediate region in the vertical direction on the front end surface 28 a passes through the vicinity of the rear focal point f of the projection lens 20 and enters the projection lens 20. Further, the light L6 is refracted by the projection lens 20 and guided to the vicinity of the cut-off line CL shown in FIG.

  Of the light from the second optical system 22, part of the light L7 reflected by the region above the front end surface 28a is incident on the transparent member 41 from the lower surface 41b. The light L7a is emitted from the upper surface side of the transparent member 41, is further refracted by the projection lens 20, and is emitted downward. Thereby, the light L7a irradiates the lower irradiation region Lp, which is near the lower side of the upper irradiation region Hp in FIG.

  In addition, a part of the light L7, the light L7b, is reflected by the lower surface 41b of the transparent member 41, enters the projection lens 20, is further refracted by the projection lens 20, and is emitted upward. Thereby, the light L7b irradiates near the upper side of the upper irradiation region Hp in FIG.

  As described above, the vehicle headlamp 40 according to the second embodiment also turns on the first optical system 21 and the second optical system 22 to turn on the high beam in which the lower irradiation area Lp and the upper irradiation area Hp are combined. A light distribution pattern is formed. At this time, the lower surface 41b of the transparent member 41 is a total reflection surface using a total reflection phenomenon, and does not have a substantial thickness. Therefore, the lower surface 41b does not block all the light L7 from the second optical system, but allows a part of the light L7a to pass therethrough. Thereby, the light L7a from the second optical system irradiates the lower irradiation region Lp, and the lower irradiation region Lp is formed to overlap the upper irradiation region Hp. Thereby, a dark gap is not formed between the lower irradiation region Lp and the upper irradiation region Hp, and a high beam light distribution pattern with high visibility and good appearance can be formed.

  Moreover, although the said embodiment demonstrated the case where the transparent member 23 which consists of a prismatic prism was used, the shape of the transparent member 23 is not limited to this shape.

10, 40: vehicle headlamp, 20: projection lens, 21: first optical system, 22: second optical system, 23, 41: transparent member, 25a: first total reflection surface (total reflection surface), 25b : Second total reflection surface (auxiliary reflection surface), 31: first light source, 32: first reflector, 35: second light source, 36: second reflector, Ax: optical axis, CL: cut-off line, f: rear focus , L1 to L7, L7a, L7b: light, Lp: lower irradiation region, Hp: upper irradiation region

Claims (2)

A projection lens having an optical axis extending in the front-rear direction;
A first optical system comprising: a first light source; and a first reflector that reflects light from the first light source from the optical axis;
A second optical system comprising: a second light source; and a second reflector that reflects light from the second light source from the optical axis;
A transparent member disposed in the vicinity of the rear focal point of the projection lens,
The light from the first optical system passes through the transparent member and is emitted from the projection lens to the front of the lamp to form a low beam light distribution pattern.
The light from the second optical system forms a high beam light distribution pattern together with the light from the first optical system,
The transparent member includes a total reflection surface that transmits light from the second optical system and totally reflects a part of the light from the first optical system,
A vehicle headlamp, wherein a part of the edge of the total reflection surface has a shape corresponding to a cut-off line.   2. The vehicle according to claim 1, wherein the transparent member has an auxiliary reflection surface that transmits light from the first optical system and totally reflects a part of the light from the second optical system toward a projection lens. For headlamps.

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