JP2003338209A - Headlamp for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To sufficiently increase the available luminous flux of a lamp equipment without affecting the light distribution pattern formed by the reflected light from a reflector in a headlamp for a vehicle equipped with a lamp equipment unit of the projector type. <P>SOLUTION: A first additional reflector 34 is provided above an optical axis Ax between a reflector 24 and a projection lens 28 of a lamp equipment unit 20, and a second additional reflector 36 is provided below the optical axis Ax, whereby direct light forward off upper part from a light source 22a is emitted forward by the first and second additional reflectors 34, 36. In this case, a reflective surface 34a of the first additional reflector 34 is formed into an ellipitic spherical surface having a first focal point F1 at a position of the light source 22a and also having a second focal point F3 between a shade 32 and the projection lens 28. The reflected light from the first additional reflector 34 is thereby struck on the second additional reflector 36 without being screened by the shade 32 to sufficiently increase available luminous flux of a lamp equipment. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle headlamp including a so-called projector type lamp unit.

[0002]

2. Description of the Related Art Conventionally, there has been known a vehicle headlamp configured to irradiate a beam forward with a predetermined light distribution pattern by a projector-type lamp unit.

In this projector type lamp unit, light from a light source disposed on an optical axis extending in the vehicle front-rear direction is condensed and reflected forward by a reflector toward the optical axis, and the reflected light is forward of the reflector. It is configured to irradiate the front of the lamp through a projection lens provided in the. When the projector-type lamp unit is configured for low beam irradiation or the like, a shade is provided between the projection lens and the reflector to shield a part of the reflected light from the reflector.

Further, as described in Japanese Patent Application Laid-Open No. 2010-229715, in a projector type lamp unit, an additional reflector other than the reflector is provided to improve the lamp efficiency.

[0005]

When such an additional reflector is provided, in a projector-type lamp unit, direct light traveling obliquely upward and forward from a light source is generally not used for forming a light distribution pattern. As shown in FIG. 7, if this direct light is condensed and reflected downward by the first additional reflector 104 and then reflected forward by the second additional reflector 106, it is formed by the reflected light from the reflector 102. It is possible to increase the luminous flux used by the lamp without affecting the light distribution pattern.

However, the lamp unit 1 shown in FIG.
As in 00, when the convergence position of the reflected light from the first additional reflector 104 is located behind the shade 108, a part of the reflected light from the first additional reflector 104 is blocked by the shade 108. Therefore, there is a problem that the light flux using the lamp cannot be sufficiently increased.

The present invention has been made in view of the above circumstances, and provides a vehicle headlamp configured to irradiate a beam forward with a predetermined light distribution pattern by a projector-type lamp unit. An object of the present invention is to provide a vehicle headlamp capable of sufficiently increasing the luminous flux using a lamp without affecting a light distribution pattern formed by reflected light from a reflector.

[0008]

The present invention is to achieve the above object by devising the structure of the first additional reflector.

That is, a vehicle headlamp according to the present invention comprises a light source arranged on an optical axis extending in the vehicle front-rear direction,
A reflector that collects and reflects the light from the light source toward the optical axis toward the front, a projection lens provided in front of the reflector, and a projection lens provided between the projection lens and the reflector. A shade for shielding a part of the reflected light of the vehicle headlight for a vehicle configured to irradiate a beam forward with a predetermined light distribution pattern by a projector-type lamp unit including: For reflecting the direct light from the light source downward between the reflector above the projection lens and the projection lens.
An additional reflector is provided, and a second additional reflector that reflects the reflected light from the first additional reflector forward is provided below the optical axis.
The reflecting surface of the additional reflector is formed in an elliptic spherical shape having a first focus near the light source and a second focus between the shade and the projection lens.

The type of the "light source" is not particularly limited, and for example, a discharge light emitting portion of a discharge bulb, a filament of an incandescent bulb such as a halogen bulb, or the like can be adopted.

The above-mentioned "first additional reflector" is provided above the optical axis. At this time, it may be provided directly above the optical axis, or may be provided obliquely above the optical axis. Good. Further, only one "first additional reflector" may be provided, or a plurality of "first additional reflectors" may be provided.

Further, the position of the "second focal point" of the ellipsoidal spherical surface constituting the reflecting surface of the first additional reflector may be set on the optical axis as long as it is between the shade and the projection lens. It may be set at a position off the optical axis. In the latter case, it may be set at a position deviated in any of up, down, left, and right directions from the optical axis.

If the "second additional reflector" is constructed so as to reflect the reflected light from the first additional reflector forward, the specific configuration of the reflection surface shape, size, etc. is not particularly limited. Not something.

[0014]

As described above, the vehicular headlamp according to the present invention is provided with the projector type lamp unit, but the reflector above the optical axis and the projection lens are: Since the first additional reflector that reflects the direct light from the light source downward is provided, and the second additional reflector that reflects the reflected light from the first additional reflector forward is provided below the optical axis, In the projector-type lamp unit, direct light directed obliquely upward and forward from a light source not used for forming a light distribution pattern can be emitted forward by the first and second additional reflectors. As a result, the light distribution pattern emitted from the lamp unit forward is formed by the reflected light from the second additional reflector, in addition to the light distribution pattern formed by the light reflected by the reflector and transmitted through the projection lens. A light distribution pattern can be added.

In this case, in the present invention, the reflecting surface of the first additional reflector is formed in an elliptical spherical shape having a first focus near the light source and a second focus between the shade and the projection lens. Therefore, the reflected light from the first additional reflector can be configured to be incident on the second additional reflector without being blocked by the shade, whereby the luminous flux used by the lamp can be sufficiently increased.

As described above, according to the present invention, in the vehicle headlamp configured to irradiate the beam forward with a predetermined light distribution pattern by the projector type lamp unit, it is formed by the reflected light from the reflector. It is possible to sufficiently increase the luminous flux using the lamp without affecting the light distribution pattern.

As described above, the specific structure of the second additional reflector is not particularly limited.
If the reflecting surface of the additional reflector is formed into a quadric surface shape (that is, parabolic shape, elliptical shape or hyperboloidal shape) having a focal point near the second focal point of the reflecting surface of the first additional reflector, The reflected light from the additional reflector can be easily reflected and controlled by the second additional reflector.

In the above structure, if the reflecting surface of the second additional reflector is formed so as to diffuse and reflect the light reflected from the first additional reflector in the left-right direction, the additional light distribution pattern that spreads widely to the left and right on the road surface ahead of the vehicle. Can be obtained. At that time, in the present invention, since the second focal point of the reflecting surface of the first additional reflector is located between the shade and the projection lens, the second additional reflector may be arranged near the front end portion of the lamp unit. It will be possible. Further, by adopting such an arrangement, it becomes possible to easily prevent the diffused reflection light from the second additional reflector from being blocked by other members constituting the vehicle headlamp.

In many vehicle headlamps, an extension reflector is provided at the peripheral edge of the front end of the lamp unit. In the above structure, the second additional reflector is formed so that its front end extends to the vicinity of the projection lens. Then, the projection lens and the second additional reflector can be arranged substantially flush with the extension reflector. As a result, the appearance of the lamp can be improved, and moreover, the reflected light from the first additional reflector can be easily diffused and reflected in the left-right direction.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a side sectional view showing a vehicle headlamp according to an embodiment of the present invention.

As shown in the figure, the vehicle headlamp 10 includes:
The lamp unit 20 has an aiming mechanism 5 in the lamp chamber formed by the transparent cover 12 and the lamp body 14 which are transparent.
It is accommodated so as to be tiltable in the vertical direction and the horizontal direction via 0, and an extension reflector 16 is provided at the peripheral edge of the front end of the lamp unit 20 in the lamp chamber.

2 and 3 are a side sectional view and a plan sectional view showing the lamp unit 20 as a single piece, and FIG. 4 is a perspective view showing main constituent elements of the lamp unit 20.

As shown in these figures, the lamp unit 20 is a projector type lamp unit for low beam irradiation, and includes a discharge bulb 22, a reflector 24, and
A holder 26, a projection lens 28, a retaining ring 30, a shade 32, a first additional reflector 34,
And a second additional reflector 36.

The discharge bulb 22 is a metal halide bulb, and its discharge light emitting portion 22a (light source) is arranged in the vehicle front-rear direction (more precisely, in a downward direction of about 0.5 to 0.6 ° with respect to the vehicle front-rear direction). It is attached to the reflector 24 so as to be arranged coaxially with the extending optical axis Ax.

The reflector 24 has a substantially elliptic spherical reflecting surface 24a having the optical axis Ax as its central axis. The reflecting surface 24a has an elliptical cross-sectional shape including the optical axis Ax, and its eccentricity is set to gradually increase from the vertical cross section to the horizontal cross section. However, the rear vertices of the ellipses forming each of these cross sections are set at the same position. The light source 22a is arranged at the first focal point F1 of an ellipse forming the vertical cross section of the reflecting surface 24a.
As a result, the reflecting surface 24a collects and reflects the light from the light source 22a forward toward the optical axis Ax, and at that time, in the vertical cross section including the optical axis Ax, the second focal point of the ellipse. It is designed to substantially converge to F2.
A notch 24b is formed at the upper end of the front end opening of the reflector 24.

The holder 26 is formed in a tubular shape so as to extend forward from the front end opening of the reflector 24, is fixedly supported by the reflector 24 at its rear end, and has a retaining ring at its front end. The projection lens 28 is fixedly supported via 30. A cutout portion 26a is formed at the lower end of the holder 26. A first additional reflector 34 (which will be described later) is provided at the upper end of the holder 26.
It is formed integrally with.

The projection lens 28 is a plano-convex lens having a convex front surface and a flat rear surface. And
The projection lens 28 is arranged on the optical axis Ax so that the rear focal position of the projection lens 28 coincides with the second focal point F2 of the reflecting surface 24a of the reflector 24. As a result, on the focal plane including the second focal point F2. The image of is projected as a reverse image to the front.

The shade 32 is formed so as to extend substantially along a vertical plane orthogonal to the optical axis Ax, and both left and right ends thereof wrap around to the front side. It is fixed to the holder 26 while being arranged so as to pass through. And this shade 3
Reference numeral 2 shields a part of the reflected light from the reflecting surface 24a of the reflector 24 and removes the upward irradiation light emitted from the lamp unit 20. As a result, the low-beam irradiation is performed downward with respect to the optical axis Ax. Light (the beam shown by the solid line in FIG. 2) is obtained. And this
A left-beam low-beam light distribution pattern P (L) having a so-called Z-shaped cut-off line CL having a difference in right and left steps as shown in FIG. 6 is formed.

The first additional reflector 34 has a reflecting surface 34a formed in an elliptical spherical shape. The first focal point of the first additional reflector 34 is the reflection surface 2 of the reflector 24.
4a is set at the same position as the first focus F1 and the second focus F3 of the first additional reflector 34 is set at a position below the optical axis Ax between the shade 32 and the projection lens 28. There is. At this time, the central axis Ax1 of the ellipsoidal spherical surface that constitutes the reflecting surface 34a is set in a direction that forms an included angle α with the optical axis Ax in the vertical plane including the optical axis Ax. This included angle α is 5 to 45 ° (preferably 10 to 45 °).
It is set to a value within a range of 30 ° (for example, a value of about 20 °).

The second additional reflector 36 is provided near the lower part of the holder 26. This second additional reflector 3
6 is formed integrally with the shade 32 so as to extend forward from the lower end of the shade 32. The reflecting surface 36a of the second additional reflector 36 has a focus at the position of the second focal point F3 of the reflecting surface 34a of the first additional reflector 34 and is a straight line substantially parallel to the optical axis Ax passing through the second focal point F3 (specifically, Specifically, a plurality of diffuse reflection elements 36s are formed on a paraboloid of revolution whose central axis is a straight line that is slightly downward toward the front with respect to the optical axis Ax.
These diffuse reflection elements 36s are formed in vertical stripes,
The light incident on the reflecting surface 36a is diffused and reflected in the left-right direction.

As shown in FIG. 2, the direct light traveling obliquely upward and forward from the light source 22a is incident on the reflecting surface 34a of the first additional reflector 34. Since the reflecting surface 34a is formed in an elliptical spherical shape, The light reflected by the reflecting surface 34a converges on the second focal point F3. The convergent light to the second focal point F3 is incident on the reflecting surface 36a of the second additional reflector 36, and the incident light is incident as divergent light from the second focal point F3. Therefore, the light reflected by the reflecting surface 36a is not diffused in the up-down direction but is diffused in the left-right direction, and is radiated forward, whereby the low-beam light distribution pattern P (L ), An additional light distribution pattern P (A) that spreads to the left and right more than the low beam light distribution pattern P (L) is formed on the road surface slightly on the front side.

FIG. 5 is a bottom view showing the lamp unit 20 together with the extension reflector 16.

As shown, the second additional reflector 36
Has a front end portion 36b extending to the vicinity of the projection lens 28, and is disposed substantially flush with the extension reflector 16 together with the projection lens 28. At this time, the opening 16a of the extension reflector 16
Are located behind the front end position of the projection lens 28 by a distance L, and the inner diameter D of the opening 16a is set to a value slightly larger than that of the projection lens 28.

If the second additional reflector 36 is arranged at the rear position shown by the two-dot chain line in the figure as in the conventional case, the extension reflector 16 may block the light reflected from the second additional reflector 36. Instead, in order to diffusely reflect the light in the left-right direction, the extension reflector 16 is separated from the front end position of the projection lens 28 by a distance L ′.
It is necessary to dispose (L '> L) only at the rear position or set the inner diameter of the opening 16a to a value D' (D '> D) which is considerably larger than that of the projection lens 28. In the case of adopting the former configuration, the lamp unit 20 largely projects forward from the extension reflector 16,
When the latter configuration is adopted, a large gap is formed between the lamp unit 20 and the extension reflector 16, and in either case, the appearance of the lamp is impaired.

On the other hand, in this embodiment, since the front end portion 36b of the second additional reflector 36 extends to the vicinity of the projection lens 28, the lamp unit 20 does not largely project forward from the extension reflector 16. Moreover, a large gap is not formed between the lamp unit 20 and the extension reflector 16.

As described above in detail, the vehicular headlamp 10 according to this embodiment is a projector type lamp unit 20.
, But the reflector 2 above the optical axis Ax
A first additional reflector 34 for reflecting the direct light from the light source 22a downward is provided between the projection lens 28 and the projection lens 28, and the reflected light from the first additional reflector 34 is provided below the optical axis Ax. Since the second additional reflector 36 that reflects the light forward is provided, the light source 22 a that is not used for forming the light distribution pattern in the lamp unit 20.
Direct light traveling obliquely upward from the front can be emitted forward by the first and second additional reflectors 34 and 36. Thus, in addition to the low beam light distribution pattern P (L) formed by the light reflected by the reflector 24 and transmitted through the projection lens 28, the second additional reflector is used as the light distribution pattern emitted forward from the lamp unit 20. An additional light distribution pattern P (A) formed by the reflected light from 36 can be added.

At this time, in this embodiment, the reflecting surface 34a of the first additional reflector 34 has the first focal point F1 at the position of the light source 22a and the second focal point F3 between the shade 32 and the projection lens 28. Since it is formed in the elliptical spherical shape, it is possible to configure so that the reflected light from the first additional reflector 34 is incident on the second additional reflector 36 without being blocked by the shade 32. The utilized luminous flux can be sufficiently increased.

As described above, according to the present embodiment, it is possible to sufficiently increase the luminous flux used by the lamp without affecting the light distribution pattern formed by the reflected light from the reflector 24.

In the present embodiment, the reflecting surface 36a of the second additional reflector 36 is the first additional reflector 34.
Since a plurality of diffuse reflection elements 36s are formed on the paraboloid of revolution whose focal point is the second focal point F3 of the reflection surface 34a, the reflection light from the first additional reflector 34 is diffused and reflected in the left-right direction. It is possible to form the additional light distribution pattern P (A) that diffuses widely to the left and right on the road surface in front of the vehicle.

At that time, the vehicle headlamp 1 according to the present embodiment.
0, the reflecting surface 34a of the first additional reflector 34
Since the second focal point F3 of the second additional reflector 36 is located between the shade 32 and the projection lens 28 and the second additional reflector 36 is disposed near the front end portion of the lamp unit 20, the reflected light from the first additional reflector 34 is Even when the second additional reflector 36 is configured to diffuse and reflect the light in the left-right direction, the reflected light from the second additional reflector 36 is forwarded without being blocked by other members of the vehicle headlamp 10. Can be irradiated.

Further, in the present embodiment, the extension reflector 16 is provided on the peripheral portion of the front end of the lamp unit 20.
However, since the front end portion 36b of the second additional reflector 36 extends to the vicinity of the projection lens 28, the projection lens 28 and the second additional reflector 36 are substantially flush with the extension reflector 16. Can be placed. As a result, the appearance of the lamp can be improved, and moreover, the reflected light from the first additional reflector 34 can be easily diffused and reflected in the left-right direction.

In the present embodiment, the additional light distribution pattern P (A) has been described as being a diffused light distribution pattern that spreads to the left and right more than the low beam light distribution pattern P (L). It is also possible to employ a light pattern (for example, a condensing light distribution pattern that reinforces the hot zone (high-luminance region) of the low-beam light distribution pattern P (L)).

[Brief description of drawings]

FIG. 1 is a side sectional view showing a vehicle headlamp according to an embodiment of the present invention.

FIG. 2 is a side sectional view showing the lamp unit of the vehicle headlamp as a single item.

FIG. 3 is a plan sectional view showing the lamp unit as a single item.

FIG. 4 is a perspective view showing main components of the lamp unit.

FIG. 5 is a bottom view showing the lamp unit together with an extension reflector.

FIG. 6 is a perspective view showing a light distribution pattern formed on a virtual vertical screen arranged at a position 25 m in front of the lamp by the beam irradiation from the lamp unit.

FIG. 7 is a view similar to FIG. 2 showing a conventional example.

[Explanation of symbols]

10 Vehicle headlights 12 transparent cover 14 lamp body 16 extension reflector 16a opening 20 Projector type lighting unit 22 Discharge valve 22a Discharge light emitting part (light source) 24 reflector 24a reflective surface 24b Notch 26 Holder 26a Notch 28 Projection lens 30 retaining ring 32 shades 32a upper edge 34 First Additional Reflector 34a reflective surface 36 Second Additional Reflector 36a reflective surface 36b front end 36s Diffuse reflection element 50 Aiming mechanism Ax optical axis Ax central axis CL cut-off line F1 first focus F2, F3 second focus P (A) Additional light distribution pattern P (L) Low beam light distribution pattern

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F21Y 101: 00 F term (reference) 3K042 AA08 AC01 AC06 BA04 BA08 BB05 BB13 BB14 BC01 BC09 BD04 BE09

Claims (4)

[Claims] 1. A light source arranged on an optical axis extending in the vehicle front-rear direction, a reflector for converging light from the light source forward toward the optical axis, and a reflector provided in front of the reflector. A projector type lamp unit including a projection lens and a shade provided between the projection lens and the reflector to shield a part of the reflected light from the reflector is used to provide a front light distribution pattern with a predetermined light distribution pattern. In a vehicle headlamp configured to perform beam irradiation, a first additional reflector that reflects direct light from the light source downward is provided between the reflector above the optical axis and the projection lens. A second additional reflector that reflects the reflected light from the first additional reflector to the front is provided below the optical axis, and the first additional reflector is provided. The vehicular headlamp, wherein the reflecting surface of the reflector is formed in an elliptical spherical shape having a first focal point in the vicinity of the light source and a second focal point between the shade and the projection lens. . 2. The reflection surface of the second additional reflector is formed into a quadric surface having a focal point in the vicinity of the second focal point of the reflection surface of the first additional reflector. The vehicle headlamp described. 3. The reflection surface of the second additional reflector is formed so as to diffuse and reflect the reflected light from the first additional reflector in the left-right direction. Vehicle headlights. 4. An extension reflector is provided at a peripheral edge of a front end of the lamp unit, and a front end of the second additional reflector extends to the vicinity of the projection lens. The vehicle headlight according to any one of the above.