JP4315342B2 - Vehicle headlamp - Google Patents

Description

The present invention relates to a projector-type vehicle headlamp, and more particularly, a side-insertion type in which a light source bulb configured as a line segment light source is inserted and fixed to a reflector from the side of a lens central axis extending in the vehicle front-rear direction. This relates to a vehicle headlamp.

In general, a projector-type vehicle headlamp has a projection lens arranged so that its lens central axis extends in the vehicle front-rear direction, and a light source bulb is arranged behind the rear focal point of the projection lens. The light from the light source bulb is reflected by the reflector toward the center axis of the lens.

Usually, the light source bulb is configured as a line light source whose light emitting portion extends in the bulb axis direction.
In the case of a conventional projector-type vehicle headlamp, such a light source bulb is inserted and fixed to a reflector from the rear of the vehicle headlamp with the bulb axis (optical axis) being along the lens central axis. Many of them have a rear insertion type lamp structure.
However, the headlamp having such a configuration has a problem in that the lamp becomes longer in the vehicle front-rear direction, leading to an increase in the size of the headlamp.

Therefore, a so-called side-insertion type lamp configuration is proposed in which a light source bulb configured as a line segment light source is inserted and fixed to a reflector from the side of the lens central axis in a projector-type vehicle headlamp ( For example, see Patent Document 1 and Patent Document 2).

In such a side-insertion type lamp configuration, it is expected that the front and rear lengths of the lamps can be shortened, and the headlamp can be made compact accordingly.

Japanese Utility Model Publication No. 2-47704 Japanese Patent Laid-Open No. 2001-6408

However, in the case of a side-insertion-type lamp configuration, the following problem arises because the light source bulb is configured as a line segment light source.
That is, the light distribution of the line segment light source has a luminous intensity distribution in which the luminous intensity is highest in the direction orthogonal to the bulb axis and the luminous intensity in the bulb axis direction is lowest. Therefore, when a side-insertion type lamp configuration is adopted, the amount of incident light on the front surface of the reflector in the bulb insertion direction on the reflecting surface is extremely reduced, and therefore, formed by the irradiation light from the vehicle headlamp. There arises a problem that it is difficult to ensure sufficient brightness of the light distribution pattern.

The present invention has been made in view of such circumstances, and is a projector type in which a light source bulb configured as a line segment light source is inserted and fixed to a reflector from the side with respect to a lens central axis of a headlamp. In the vehicular headlamp, the brightness of the light distribution pattern due to the insufficient amount of light incident on the reflector's reflecting surface on the front side of the bulb insertion direction is resolved, and the headlamp's An object of the present invention is to provide a vehicular headlamp that is not only compact, but can sufficiently ensure the brightness of a light distribution pattern formed by irradiation light.

(1) A vehicular headlamp according to the present invention is configured as a projection lens disposed on a lens central axis extending in the vehicle front-rear direction and a line segment light source extending in the bulb axis direction. A light source bulb disposed on the rear side, a first reflector for reflecting light from the light source bulb forward and toward the lens central axis, and an upper edge near the lens central axis in the vicinity of the rear focal point And a shade that shields a part of the reflected light from the first reflector and a part of the direct light from the light source bulb, and the light source bulb has the bulb axis as the lens. A vehicle headlamp that is inserted and fixed to the first reflector from a side of the lens central axis in a direction orthogonal to the central axis,
Near the center axis of the lens between the projection lens and the first reflector, the light source bulb has a substantially elliptical reflective surface with the light emitting portion of the light source bulb as one focal point, and is incident from the light emitting portion. A second reflector for reflecting the light to the front region of the light source bulb in the bulb insertion direction is provided,
A third reflector for reflecting the reflected light from the second reflector toward the projection lens is provided in a front region in the bulb insertion direction of the light source bulb.

(2) Preferably, in the above (1), the light incident from the light emitting part having a substantially elliptical reflecting surface with the light emitting part as a focal point is provided between the shade and the light source bulb. Third
A fourth reflector that reflects in a region adjacent to the reflector is provided, and a fifth reflector that reflects reflected light from the fourth reflector toward the projection lens is provided in a region adjacent to the third reflector. It is characterized by that.

(3) Preferably, in the above (1) or (2), the horizontal diffusion angle on the light distribution pattern of the irradiation light emitted forward from the third reflector through the projection lens is The third reflector and the fifth reflector are configured to be larger than a horizontal diffusion angle on a light distribution pattern of irradiation light emitted forward from the five reflectors through the projection lens. And

According to the vehicle headlamp of the present invention, the light source bulb configured as the line segment light source has the bulb axis in the direction perpendicular to the lens central axis of the headlamp, and the first from the side of the lens central axis. Because it is a so-called side-insertion type lamp structure that is inserted and fixed to the reflector, the space occupied in the front-rear direction when the light source bulb is arranged is small, and the headlamp can be made compact by shortening the front-rear length of the lamp That is, the vehicle body mounting space for the headlamp can be reduced.

In addition, in the case of a side-insertion type lamp configuration, the amount of light incident on the front region of the reflector in the bulb insertion direction is usually low because the amount of light emitted from the light emitting portion of the light source bulb in the bulb axial direction is weak. Insufficient brightness of the light distribution pattern due to the shortage occurs.
However, in the vehicle headlamp of the present invention, the light emitted obliquely upward from the light emitting part is reflected by the second reflector to the front region in the bulb insertion direction of the light source bulb, and the amount of incident light to the front region in the bulb insertion direction is insufficient. Can be eliminated. Then, the reflected light from the second reflector is reflected again toward the projection lens by the third reflector provided in the front region in the bulb insertion direction, and is effectively used as the front irradiation light.
Therefore, the amount of light irradiated forward is increased by the reflected light reflected again from the front region in the bulb insertion direction toward the projection lens by the third reflector, and the light distribution formed by the irradiation light irradiated forward from the projection lens. The brightness of the pattern can be sufficiently secured.
Moreover, the light incident on the second reflector from the light emitting unit is direct light emitted obliquely upward on the front side from the light emitting unit, and as it is, the front illumination light is directed upward and does not conform to the passing light distribution pattern. Therefore, it is usually cut and not used for front lighting. However, in the vehicle headlamp according to the present invention, the light emitted obliquely upward from the light emitting portion toward the front side can be used for front illumination by the second reflector and the third reflector, and thus is emitted from the light emitting portion. The utilization factor of the luminous flux is improved, and a bright light distribution pattern can be obtained even with a light source bulb having a small output.

In the vehicle headlamp described in (2) above, the light emitted obliquely downward from the light emitting portion is reflected by the fourth reflector to the region adjacent to the third reflector, and further from the fourth reflector. The reflected light is reflected again toward the projection lens by the fifth reflector provided adjacent to the third reflector, and is effectively used as the forward irradiation light.
Therefore, the amount of light irradiated forward from the projection lens is increased by the fourth reflector and the fifth reflector, and the brightness of the light distribution pattern formed by the irradiation light irradiated forward from the projection lens is further improved.

In the vehicle headlamp described in the above (3), the reflected light from the first reflector is mainly irradiated forward through the projection lens, so that, for example, a basic headlight that matches a passing light distribution pattern or the like is used. An irradiation pattern is formed, and an irradiation pattern by reflected light from the third reflector and an irradiation pattern by reflected light from the fifth reflector are superimposed on the basic irradiation pattern.
In this case, as described above, if a difference is given to the diffusion angle in the horizontal direction at the time of forward irradiation between the third reflector and the fifth reflector, as shown in FIG. 3, irradiation with the highest luminous intensity is performed. The pattern is located at the center of the front irradiation surface, and the irradiation surface with low intensity spreads around it in stages.
Visibility can be improved by optimizing the illuminance distribution.

Hereinafter, embodiments of a vehicle headlamp according to the present invention will be described in detail with reference to the accompanying drawings.
1 is a side sectional view of an embodiment of a vehicle headlamp according to the present invention, FIG. 2 is a plan sectional view of the vehicle headlamp shown in FIG. 1, and FIG. 3 is a vehicle shown in FIG. It is explanatory drawing of the light distribution pattern which a headlamp forms.

In the vehicle headlamp 1 of this embodiment, a lamp unit 5 is housed in a lamp chamber formed by a transparent transparent cover (cover) 2 and a lamp body 4.
The lamp unit 5 is supported by the lamp body 4 through an aiming mechanism (not shown). The aiming mechanism is a mechanism for finely adjusting the mounting position and the mounting angle of the lamp unit 5, and at the stage of adjusting the aiming, the lens center axis Ax of the lamp unit 5 is 0.5-0. It extends in the downward direction by about 6 degrees.

The lamp unit 5 is a projector-type lamp unit, and extends in the bulb lens V direction (in FIG. 1, the direction orthogonal to the paper surface) disposed on the lens central axis Ax extending in the vehicle front-rear direction. A light source bulb 10 such as a discharge bulb or a halogen bulb configured as a line light source and having a light emitting portion 10a positioned on a lens central axis Ax behind the focal point F on the rear side of the projection lens 8, and the light source bulb 10 Light B1 emitted from the light source bulb 10 after being inserted and fixed
A first reflector 13 that reflects the lens toward the lens center axis Ax and a rear focal point F
In the vicinity, the shade 15 is disposed so that the upper end edge is positioned in the vicinity of the lens center axis Ax and shields a part of the reflected light from the first reflector 13, the front end opening edge of the second reflector described later, and the projection lens 8. And a substantially cylindrical holder 17 serving as a connecting means between the two.

The projection lens 8 is a plano-convex lens having a convex front surface and a flat rear surface, and projects an image on the focal plane including the rear focus F forward as a reverse image.

In the case of this embodiment, the light source bulb 10 has a light emitting section 10 that emits light on the bulb axis V by discharge.
The metal halide valve having a is inserted and fixed to the first reflector 13 from the side of the lens center axis Ax with the valve axis V in a direction orthogonal to the lens center axis Ax.

As shown in FIG. 2, the first reflector 13 has a substantially elliptical spherical reflecting surface 13a having a lens central axis Ax passing through the light emitting portion 10a as a central axis.
The reflecting surface 13a has a cross-sectional shape including the lens center axis Ax in a substantially elliptical shape with the center position of the light emitting unit 10a as the first focus (F1) and the vicinity of the rear focus F of the projection lens 8 as the second focus. It is set so that the light from the light emitting portion 10a is condensed and reflected toward the lens central axis Ax toward the front. The eccentricity of the reflecting surface 13a is set so as to gradually increase from the vertical cross section toward the horizontal cross section.

The shade 15 is formed integrally with the holder 17 so as to be positioned in a substantially lower half of the internal space of the holder 17. The upper edge 15a of the shade 15 includes a light / dark boundary forming part that passes through the rear focal point F of the projection lens 8 and forms a cut-off line of the passing light distribution pattern. Therefore, the shade 15 shields a part of the reflected light from the reflecting surfaces of the first reflector 13 and the third reflector and the fifth reflector described later, and removes most of the upward light emitted forward from the projection lens 8. It has become.

In the case of this embodiment, as shown in FIG. 1, the center of the light emitting part 10a of the light source bulb 10 is set as one focal point substantially above the lens center axis Ax between the projection lens 8 and the first reflector 13. At the same time, the light source bulb 10 has light B2 incident from the light emitting portion 10a, which has a substantially elliptical reflecting surface 21a having a focal point F2 in front of the front end of the light source bulb 10 on the bulb axis of the light source bulb 10 as the other focus. The second reflector 21 is provided to reflect the front region R1 in the valve insertion direction.

Further, a third reflector 23 having a reflection surface 23 a that reflects the reflected light from the second reflector 21 toward the projection lens 8 is provided in the bulb insertion direction front region R1 of the light source bulb 10.

In the case of the present embodiment, the lens center axis Ax is between the shade 15 and the light source bulb 10.
Is provided with a reflection surface 25a having a substantially elliptical shape with the two focal points F1 and F2 as the focal points, and the light incident from the light emitting unit 10a is reflected to a region adjacent to the third reflector 23. A reflector 25 is provided.

Further, in a region adjacent to the third reflector 23, a fifth reflector 27 having a reflection surface 27a that reflects the reflected light from the fourth reflector 25 toward the projection lens 8 is provided.
The reflecting surface 27a of the fifth reflector 27 has a substantially elliptical surface shape having two focal points F2 and F3 in FIG. The focal point F3 is on the upper edge 15a of the shade 15 and the projection lens 8
Is set to a position shifted from the rear focus F.

In the case of the present embodiment, the horizontal diffusion angle on the light distribution pattern of the irradiation light emitted forward from the third reflector 23 via the projection lens 8 causes the projection lens 8 to move from the fifth reflector 27. The third reflector 23 and the fifth reflector 27 are configured to be larger than the horizontal diffusion angle on the light distribution pattern of the irradiation light emitted forward through.

According to the vehicle headlamp 1 described above, the light source bulb 10 configured as a line light source has the bulb axis V in a direction perpendicular to the lens central axis Ax of the headlamp, Since it is inserted and fixed to the first reflector 13 from the side to form a so-called side-insertion type lamp structure, a space occupied in the front-rear direction when the light source bulb 10 is arranged can be reduced, and by shortening the front-rear length of the lamp It is possible to make the headlamp compact, that is, to reduce the vehicle mounting space of the headlamp.

Further, in the case of a side-insertion type lamp configuration, normally, since the amount of light emitted from the light emitting portion 10a of the light source bulb 10 in the bulb axis V direction is weak, the bulb insertion direction front region R1 on the reflecting surface of the reflector. Insufficient brightness of the light distribution pattern due to an insufficient amount of incident light occurs.
However, in the vehicle headlamp 1 described above, as shown in FIG. 1, the light B2 radiated obliquely upward from the light emitting portion 10a is directed to the front region R1 in the bulb insertion direction of the light source bulb 10 by the second reflector 21. The shortage of the amount of incident light that is reflected and enters the front region R1 in the bulb insertion direction is resolved. Then, the reflected light from the second reflector 21 is reflected again toward the projection lens 8 by the third reflector 23 provided in the bulb insertion direction front region R1, and is effectively used as the front irradiation light.
Therefore, the amount of light irradiated forward is increased by the reflected light reflected again from the bulb insertion direction front region R1 toward the projection lens 8 by the third reflector 23, and formed by the irradiation light irradiated forward from the projection lens 8. It is possible to sufficiently secure the brightness of the light distribution pattern.

In addition, the light incident on the second reflector 21 from the light emitting unit 10a is direct light emitted obliquely upward on the front side from the light emitting unit 10a, and as it is, the front illumination light is directed upward.
Since it does not conform to the passing light distribution pattern, it is usually cut and not used for front lighting. However, in the vehicle headlamp 1 of the present embodiment, light emitted obliquely upward on the front side from the light emitting unit 10a can be used for front illumination by the second reflector 21 and the third reflector 23. The utilization factor of the light beam emitted from the light emitting unit 10a is improved, and a bright light distribution pattern can be obtained even with the light source bulb 10 having a small output.

Further, in the vehicle headlamp 1 of the present embodiment, the light emitted obliquely downward from the light emitting unit 10a is reflected by the fourth reflector 25 to the region adjacent to the third reflector 23, and further, the fourth reflector 25. The reflected light from is reflected again toward the projection lens 8 by the fifth reflector 27 provided adjacent to the third reflector 23, and is effectively used as the front irradiation light.
Therefore, the amount of light irradiated forward from the projection lens 8 is increased by the fourth reflector 25 and the fifth reflector 27, and the brightness of the light distribution pattern formed by the irradiation light irradiated forward from the projection lens 8 is further improved. To do.

Moreover, in the vehicle headlamp 1 of the present embodiment, as shown in FIG. 3, the first reflector 13 is mainly used.
The reflected light from the front is irradiated through the projection lens 8 to form, for example, a basic irradiation pattern P1 suitable for a passing light distribution pattern for right-side traveling, and the basic irradiation pattern P1. The irradiation pattern P2 by the reflected light from the third reflector 23 and the irradiation pattern P3 by the reflected light from the fifth reflector 27 are overlaid on top.
In that case, as described above, if the third reflector 23 and the fifth reflector 27 have a difference in the diffusion angle in the horizontal direction during the front irradiation, as shown in FIG. The irradiation pattern P3 with the highest luminous intensity is positioned at the center of the front irradiation surface on the opposite lane side, and the irradiation surfaces P2, P1 with low luminous intensity spread stepwise around it, by optimizing the illuminance distribution, Visibility can be further improved.

The specific configurations of the lamp body, the cover, the light source bulb, the reflector, and the like related to the vehicle headlamp of the present invention are not limited to the configurations of the above-described embodiments, and various configurations can be made based on the gist of the present invention. Of course, it is possible to take the form.
For example, in the vehicle headlamp 1 of the above-described embodiment, as shown in FIG. 3, the irradiation pattern P3 having the highest luminous intensity is positioned at the center of the front irradiation surface on the opposite lane side, and the luminous intensity is low around the irradiation pattern P3. Although the illumination surfaces P2 and P1 have an illuminance distribution that gradually spreads, the irradiation pattern P2 by the reflected light from the third reflector 23, the first illumination pattern P1 that conforms to the passing light distribution pattern for the left side traveling, 5 By irradiating the irradiation pattern P3 by the reflected light from the reflector 27, the irradiation pattern P3 having the highest luminous intensity is positioned at the center of the front irradiation surface on the own lane side, and irradiation surfaces P2 and P1 having low luminous intensity are provided around the irradiation pattern P3. Various illuminance distributions such as an illuminance distribution that spreads in stages can be formed.

It is side sectional drawing of one Embodiment of the vehicle headlamp which concerns on this invention. It is a plane sectional view of the vehicle headlamp shown in FIG. It is explanatory drawing of the light distribution pattern in the vehicle headlamp shown in FIG.

Explanation of symbols

1 Vehicle headlamp 2 Transparent cover (cover)
4 Lamp body 8 Projection lens 10 Light source bulb 10a Light emitting part 13 First reflector 15 Shade 21 Second reflector 21a Reflective surface 23 Third reflector 23a Reflective surface 25 Fourth reflector 25a Reflective surface 27 Fifth reflector 27a Reflective surface Ax Lens central axis F Rear focus R1 Front region in the valve insertion direction

Claims (3)

A projection lens disposed on a lens central axis extending in the vehicle front-rear direction; a light source bulb configured as a line light source extending in the bulb axis direction and disposed rearward of the rear focal point of the projection lens; A first reflector that reflects light from the light source bulb toward the lens center axis toward the front, and an upper end edge that is positioned in the vicinity of the lens center axis in the vicinity of the rear focal point, from the first reflector. A shade that blocks a part of the reflected light of the light source and a part of the direct light from the light source bulb, and the light source bulb has a bulb axis in a direction perpendicular to the lens central axis, A vehicle headlamp that is inserted and fixed to the first reflector from the side,
Near the center axis of the lens between the projection lens and the first reflector, the light source bulb has a substantially elliptical reflective surface with the light emitting portion of the light source bulb as one focal point, and is incident from the light emitting portion. A second reflector for reflecting the light to the front region of the light source bulb in the bulb insertion direction is provided,
A vehicular headlamp characterized in that a third reflector for reflecting light reflected from the second reflector toward the projection lens is provided in a front region of the light source bulb in the bulb insertion direction. A fourth surface that has a substantially elliptical reflecting surface with the light emitting portion as a focal point between the shade and the light source bulb and reflects light incident from the light emitting portion to a region adjacent to the third reflector. A reflector is provided,
2. The vehicle-use front according to claim 1, wherein a fifth reflector that reflects reflected light from the fourth reflector toward the projection lens is provided in an area adjacent to the third reflector. Lighting. The horizontal diffusion angle on the light distribution pattern of the irradiation light emitted forward from the third reflector via the projection lens is the irradiation light emitted forward from the fifth reflector via the projection lens. The vehicle headlamp according to claim 1, wherein the third reflector and the fifth reflector are configured to be larger than a horizontal diffusion angle on the light distribution pattern.

Images