JP2006100132A - Headlamp for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a headlamp for a vehicle capable of increasing light intensity emitted ahead from a projection lens, and selectively increasing an illuminance of a specific portion in a distribution light pattern. <P>SOLUTION: This headlamp 10 for the vehicle has, inside a lamp room 10a formed by a lens cover 12 and a lamp body 14: a light source 22a disposed on an optical axis Ax extending in the back-and-forth direction of the vehicle; a main reflector 24 reflecting light from the light source toward the optical axis Ax; the projection lens 28 disposed in front of the main reflector 24; and a shade 34 partially shading reflection light from the main reflector 24 behind the projection lens 28. The main reflector 24 partially has a reflection face 25b that is a nearly ellipsoid-shaped second reflector with a focus of the projection lens 28 as a first focus and with a mid part of the light source 22a and the shade 34 as a first focus, and has an additional reflector 30 reflecting the light from the light source 22a to the reflection face 25b. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vehicular headlamp, and more particularly to a vehicular headlamp that can constitute a large light quantity optical system without changing a light source or a projection lens.

2. Description of the Related Art Conventionally, a vehicular headlamp configured to emit light toward the front of a vehicle by a projector-type lamp unit is known.
This projector-type lamp unit condenses and reflects light from a light source arranged in the vicinity of the optical axis extending in the longitudinal direction of the vehicle toward the front by the reflector toward the optical axis, and this reflected light is directed to the front of the reflector. Irradiate the front of the lamp unit through the provided projection lens.

  When a light distribution pattern having a cut-off line at the upper end is formed by this lamp unit, a shade is provided in the vicinity of the rear focal point of the projection lens, and this shade shields part of the reflected light from the reflector. And form a cut-off line.

  Among these types of vehicle lamps, there is also a vehicle lamp that increases the amount of light forward with a simple configuration. For example, in Patent Document 1, light shielded by a shade is reflected toward a main reflector by an additional reflector different from the main reflector, and reflected light from the additional reflector is reflected forward by the reflector to forward the lamp unit. There has been proposed a vehicular lamp configured to irradiate (see, for example, Patent Document 1).

In such a vehicular lamp, it is possible to configure a large light quantity optical system by increasing the amount of light emitted forward from the projection lens without changing the light source, the projection lens, etc. Is possible.
Japanese Utility Model Publication No. 5-72006

  However, in the vehicular lamp disclosed in Patent Document 1, the light reflected by the additional reflector is reflected so as to converge in the vicinity of the light source, for example. In such a structure, since the light reflected in the vicinity of the light source is irradiated forward through the main reflector, it is possible to increase the overall light amount, but a certain part in the light distribution pattern, for example, hot Only the illuminance of the zone could not be increased.

  The present invention has been made in view of the above, and while increasing the amount of light emitted forward from the projection lens without changing the light source, the projection lens, etc., the illuminance of a specific part in the light distribution pattern is selectively selected. An object of the present invention is to provide a vehicular headlamp that can be raised.

The object of the present invention is achieved by the following configurations.
(1) In the lamp chamber formed by the cover and lamp body,
A light source disposed on an optical axis extending in the longitudinal direction of the vehicle,
A main reflector that reflects light from the light source toward the optical axis;
A projection lens disposed in front of the main reflector;
A vehicular headlamp comprising a shade that partially shields the reflected light from the main reflector behind the projection lens,
The main reflector partially includes a second reflector having a substantially ellipsoidal shape having a focal point of the projection lens as a first focal point and a second focal point between the light source and the shade;
A vehicle headlamp comprising a third reflector that reflects light from the light source to the second reflector.
(2) The vehicle headlamp according to claim 1, wherein the third reflector is rotatable around the vicinity of the second focal point.
(3) The vehicular headlamp according to claim 2, wherein the third reflector forms a condensing optical system by condensing reflected light in the vicinity of the second focal point during motorway travel. .
(4) The vehicular headlamp according to claim 2, wherein the third reflector forms a diffusion optical system by collecting reflected light at a position deviated from the second focus during normal driving. light.

  In the vehicle headlamp according to the present invention, the second reflector and the movable third reflector are provided, and the light source light applied to the third reflector is irradiated forward through the second reflector. Thus, it is possible to selectively increase the amount of light in a certain region while increasing the amount of light output than before, or to enhance the visibility by increasing the amount of light overall. Therefore, the driver can enjoy comfortable driving with good visibility by operating the driver to a required state according to the situation.

  Specifically, in the vehicle headlamp according to the present invention, it is possible to arrange the third reflector so as to constitute a condensing optical system. Therefore, when the motorway is required to improve the distance visibility, the light emitted from the projection lens via the third reflector and the second reflector is emitted forward in a relatively condensed state, and the front of the vehicle The spot area can be overlaid on the light distribution pattern formed in the above, and the amount of light in the predetermined area of the light distribution pattern can be increased in a spot manner. Accordingly, it is possible to increase the amount of light emitted forward from the projection lens without changing the light source, the projection lens, and the like, and to selectively increase the illuminance of a specific part in the light distribution pattern.

  Moreover, in the vehicle headlamp according to the present invention, the third reflector can be disposed so as to constitute a diffusion optical system. Therefore, during normal traveling, where it is preferable to improve the front visibility as a whole, the light emitted from the projection lens via the third reflector and the second reflector is more diffused than during motorway traveling. The spot area is superimposed on the light distribution pattern that is irradiated forward and formed in front of the vehicle, so that the overall light quantity of the light distribution pattern can be increased overall. Therefore, the forward visibility can be improved by increasing the amount of light emitted forward from the projection lens without changing the light source or the projection lens.

  Hereinafter, an embodiment of a vehicular lamp according to the present invention will be described with reference to the drawings. In the following description, a vehicle headlamp will be described as an example of a vehicle lamp.

  FIG. 1 is a vertical sectional view through an optical axis Ax of a vehicle headlamp that is a vehicle lamp according to the present invention, and FIG. 2 is a horizontal sectional view through an optical axis Ax of the vehicle headlamp. . FIG. 3 is a cross-sectional view showing an optical path of light from the light source toward the reflecting surface of the main reflector, and FIG. 4 is a cross-sectional view showing an optical path of light through the second and third reflectors in the first position. FIG. 5 is a cross-sectional view showing an optical path of light through the second and third reflectors in the second position. FIG. 6 is a diagram showing a light distribution pattern of the vehicle headlamp according to the present embodiment.

  In the vehicle headlamp 10 of the present embodiment, a lamp unit 20 having an optical axis Ax extending in the vehicle front-rear direction is accommodated in a lamp chamber 10a formed by a light-transmissive transparent cover 12 and a lamp body 14. Configured. The lamp unit 20 is fixed to the lamp body 14 via an aiming mechanism 50 so as to be tiltable in the vertical direction and the horizontal direction.

The aiming mechanism 50 mainly includes an aiming screw 52, a bracket 26a, and an aiming nut 54.
The aiming screw 52 is rotatably attached to the lamp body 14, is inserted through the bracket 26 a of the lamp unit 20, and is connected to the bracket 26 a via the aiming nut 54. The aiming screw 52 tilts the bracket 26a back and forth by rotating via an adjusting member (not shown). The entire lamp unit 20 is tilted by the tilt of the bracket 26a, and the direction of the optical axis Ax of the lamp unit 20 is adjusted. Note that the optical axis Ax of the lamp unit 20 after aiming adjustment is adjusted so as to extend in a downward direction, for example, by about 0.5 to 0.6 degrees with respect to the longitudinal direction of the vehicle.

  The lamp unit 20 is a projector-type lamp unit, and includes a discharge bulb 22, a main reflector 24, a lens holder 26, a projection lens 28, and a shade 34.

  The discharge bulb 22 is a discharge bulb such as a metal halide bulb, for example, and the main reflector 24 is arranged such that a light source 22a constituted by the discharge light emitting portion is located on the optical axis Ax and the bulb axis is coaxial with the optical axis Ax. Are attached to the mounting holes 24b.

  The main reflector 24 is a substantially spheroidal reflecting member, and is divided into three parts by a plane perpendicular to the optical axis Ax to form three reflecting surfaces 25a, 25b, and 25c. The reflective surface 25a formed on the side closest to the mounting hole 24b and the reflective surface 25c formed on the side farthest from the mounting hole 24b have one focal point F1 in the vicinity of the light source 22a and an optical axis in the vicinity of the shade 34. It has a substantially spheroidal shape with the other focal point F2 on Ax. Thereby, the reflective surface 25a and the reflective surface 25c reflect and condense the light from the light source 22a toward the optical axis Ax. The eccentricity of the reflecting surface 25a and the reflecting surface 25c is set to gradually increase from the vertical cross section toward the horizontal cross section.

  On the other hand, the reflecting surface 25b (second reflector) provided between the reflecting surfaces 25a and 25c has the other focal point F2 of the reflecting surfaces 25a and 25c as one focal point (first focal point), and one focal point. A substantially spheroidal shape having another focal point (second focal point) F3 is provided between F1 and the other focal point F2. The reflecting surface 25 a is a reflecting member that mainly reflects light from an additional reflector (third reflector) 30 described later toward the projection lens 28. The reflection surface 25b will be described in detail later.

  The lens holder 26 is a support member attached to the front end opening of the main reflector 24. A projection lens 28 is attached and fixed to the front end portion of the lens holder 26. Here, the lens central axis of the projection lens 28 is arranged so as to be substantially coaxial with the optical axis Ax by the lens holder 26.

  The projection lens 28 is a convex lens having a convex front surface and a flat rear surface. The rear focal point of the projection lens 28 is designed to substantially coincide with the other focal point F2 of the main reflector 24, and the light source 22a formed on the rear focal plane including the rear focal point (the other focal point) F2. Is projected forward as an inverted image.

  As shown in FIG. 1, a shade 34 integrally formed with the lens holder 26 is disposed in the internal space surrounded by the lens holder 26 and the main reflector 24. The shade 34 is a light shielding member provided so as to shield substantially the lower half of the inner space surrounded by the lens holder 26 and the main reflector 24. In the shade 34, an upper end edge 34a disposed substantially parallel to the vehicle width direction is disposed in the vicinity of the rear focal point F2 of the projection lens 28. The upper end edge 34a of the shade 34 is provided with a step in the vicinity of the optical axis Ax, and the height position is different on the left and right with the optical axis Ax of the shade 34 as an axis. The vehicle headlamp 10 of the present embodiment is configured to project a light distribution pattern 101 including a cut-off line 102 formed according to the shape of the upper end edge 34a to the front (see FIG. 6). .

  In the present embodiment, an additional reflector (third reflector) 30 is provided between the projection lens 28 and the main reflector 24 and at a position facing the lens holder 26. The third reflector 30 has a substantially spheroidal reflecting surface 30a, and is configured to be rotatable via a driving means (not shown).

  Specifically, as shown in FIGS. 1 and 2, the additional reflector 30 has one focal point (substantially the same as one focal point F1 of the main reflector 24) in the vicinity of the light source 22a, and the reflecting surface of the main reflector 24. A first position where the other focal point is located at the second focal point F3 of 25b and a certain point in the vicinity of the second focal point F3 (a point shifted from the second focal point F3) as shown in FIG. By doing so, each focal point can be displaced to the second position where the focal point is shifted from the focal points F1 and F3. Although the details will be described later, the additional reflector 30 contributes to the configuration of the condensing optical system at the first position and contributes to the configuration of the diffusion optical system at the second position.

Hereinafter, the optical path in the vehicle headlamp 10 including the lamp unit 20 of the present embodiment will be described with reference to FIGS.
As shown in FIG. 3, the light source light emitted from the light source 22a is reflected by the reflection surfaces 25a, 25b, and 25c of the main reflector 24. The light reflected by the reflecting surfaces 25a and 25c travels toward the optical axis Ax in the vicinity of the other focal point F2 of the main reflector 24. Here, the shade 34 blocks the reflected light reflected by the reflecting surfaces 25 a, 25 b, 25 c of the main reflector 24 according to the shape of the shade 34. Light that has passed forward without being blocked by the shade 34 is irradiated forward by the projection lens 28. As a result, as shown in FIGS. 6A and 6B, the light distribution pattern 101 having the cut-off line 102 corresponding to the shape of the upper end edge 34a of the shade 34 is placed in front of the vehicle headlamp 10. Projected.

  In addition, the light distribution pattern 101 shown in FIG. 6A and FIG. 6B shows the light distribution pattern in the case of the vehicle headlamp attached to the left traveling person, respectively. A cut-off line 102 that is higher on the left side than the right side of the vertical center line V in the field of view is formed.

Next, the optical path through the additional reflector 30 will be described with reference to FIGS.
As shown in FIG. 4, in a state where the additional reflector 30 is disposed at the first position, the light emitted from the light source 22a is directed to the second focal point F3 of the reflective surface 25b by the reflective surface 30a of the additional reflector 30. And reflected. The light collected near the second focal point F3 is reflected by the second reflecting surface 25b of the main reflector 24 and reflected toward the first focal point F2. Here, at the first position, the first focal point F2 is disposed so as to be substantially the same as the rear focal point of the projection lens 28, so that the projection lens 28 does not diffuse as substantially parallel light in the front. A predetermined area is irradiated.

  As shown in FIG. 6A, when the additional reflector 30 is disposed at the first position, it is a position that substantially overlaps the cut-off line 102 and is on the left side of the portion where the horizontal line H and the vertical line V intersect, so-called A spot region 103 is formed in the hot zone. The spot area 103 contributes to an increase in the amount of light emitted from the vehicle headlamp 10, and the light distribution obtained by superimposing such a spot area 103 on the light distribution pattern 102 is far away, for example, on an automobile exclusive road. It can be used as a so-called motorway light distribution for bright illumination.

  On the other hand, as shown in FIG. 5, in a state where the additional reflector 30 is disposed at the second position, the light emitted from the light source 22a is reflected by the second reflecting surface 25b of the reflecting surface 25b at the reflecting surface 30a of the additional reflector 30. Reflected toward the position deviated from. Thereafter, the reflected light from the additional reflector 30 is reflected by the reflecting surface 25b of the main reflector 24 and reflected toward a position shifted from the first focal point F2 (the rear focal point of the projection lens 28). 28 is incident. Since this reflected light is incident on the projection lens through a position shifted from the rear focal point of the projection lens 28, the reflected light is not converted into parallel light by the projection lens 28 at the second position, and the additional reflector 30 is It irradiates a predetermined area ahead in a diffused state as compared with the case where it is arranged at the position.

  As shown in FIG. 6B, when the additional reflector 30 is arranged at the second position, a spot region 104 in which the irradiation region is diffused more than the spot region 103 is formed. The spot area 104 contributes to an increase in the amount of light emitted from the vehicle headlamp 10, and in particular, the light distribution obtained by superimposing the spot area 104 on the light distribution pattern 102 is, for example, during normal traveling on a general road or the like. It can be used as a so-called passing beam light distribution.

  As described above, the vehicle headlamp 10 of the present embodiment has the light source 22a disposed on the optical axis Ax extending in the vehicle front-rear direction in the lamp chamber 10a formed by the lens cover 12 and the lamp body 14. A main reflector 24 that reflects light from the light source 22a toward the optical axis Ax, a projection lens 28 disposed in front of the main reflector 24, and reflected light from the main reflector 24 behind the projection lens 28. And a partially shielded shade 34. The main reflector 24 partially includes a reflecting surface 25b, which is a substantially elliptical second reflector having the projection lens 28 as a first focal point and a first focal point between the light source 22a and the shade 34. The additional reflector 30 that reflects the light from the light source 22a to the reflection surface 25b is provided.

  In the present embodiment, the additional reflector 30 is configured to be rotatable about the vicinity of the second focal point F3. The additional reflector 30 collects reflected light near the second focal point F3 when the motorway is running. Thus, the condensing optical system is configured, and the reflected light is condensed at a position deviated from the second focal point F3 during normal traveling to configure the diffusing optical system.

  Thus, in the vehicle headlamp 10 of this embodiment, it is possible to arrange the additional reflector 30 so as to constitute a condensing optical system. Therefore, when the motorway is required to improve the distance visibility, the light irradiated from the projection lens 28 via the additional reflector 30 and the reflecting surface 25b is irradiated in the forward direction in a relatively condensed state. By superimposing the spot area on the light distribution pattern formed in front, the amount of light in the predetermined area of the light distribution pattern can be increased in a spot manner. As described above, according to the vehicle headlamp 10 of the present embodiment, a simple configuration is added to the conventional lamp unit so that the light source 22a, the projection lens 28, and the like can be moved forward from the projection lens 28. While increasing the emitted light quantity, it is possible to selectively increase the illuminance of a specific part in the light distribution pattern.

  Moreover, in the vehicle headlamp 10 of this embodiment, it is possible to arrange the additional reflector 30 so as to constitute a diffusion optical system. Therefore, during normal travel, where it is preferable to improve the front visibility as a whole, the light emitted from the projection lens 28 via the additional reflector 30 and the reflecting surface 25b is more diffused than during motorway travel. The spot area is superimposed on the light distribution pattern that is irradiated forward and formed in front of the vehicle, so that the overall light quantity of the light distribution pattern can be increased overall. As described above, according to the vehicle headlamp 10 of the present embodiment, a simple configuration is added to the conventional lamp unit so that the light source 22a, the projection lens 28, and the like can be moved forward from the projection lens 28. The forward visibility can be improved by increasing the amount of light emitted.

  In general, during normal driving on ordinary roads other than motorways, if the illuminance in the hot zone is too high, drivers driving oncoming vehicles may feel dazzling and interfere with driver driving. It is preferable to lower the illuminance in the hot zone than during high-speed traveling. In such a case, rather than increasing the illuminance of the hot zone too much, irradiate the light forward in a relatively diffused state than during motorway travel, and the spot area in the light distribution pattern formed in front of the vehicle As a result, the driver can drive with the overall light quantity increased, and can drive more comfortably and safely.

  Thus, in the vehicle headlamp 10 of this embodiment, while increasing the amount of light output compared to the conventional case, the amount of light in a certain area is selectively increased, or the overall amount of light is increased to improve visibility. It is possible to Therefore, the driver can enjoy comfortable driving with good visibility by operating the driver to a required state according to the situation.

It is a vertical sectional view which passes along optical axis Ax of a vehicular headlamp which is a vehicular lamp according to the present invention. It is a horizontal sectional view which passes along optical axis Ax of a vehicle headlamp. It is sectional drawing which shows the optical path of the light which went to the reflective surface of the main reflector from the light source. It is sectional drawing which shows the optical path of the light through the 2nd and 3rd reflector in a 1st position. It is sectional drawing which shows the optical path of the light through the 2nd and 3rd reflector in a 2nd position. It is a figure which shows the light distribution pattern of the vehicle headlamp of this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Vehicle headlamp 12 Transparent cover 14 Lamp body 20 Lamp unit 22 Discharge bulb 22a Light source 24 Main reflector 25a, 25b, 25c Reflective surface 26 Lens holder 28 Projection lens 30 Additional reflector 34 Shade

Claims (4)

In the lamp chamber formed by the cover and lamp body,
A light source disposed on an optical axis extending in the longitudinal direction of the vehicle,
A main reflector that reflects light from the light source toward the optical axis;
A projection lens disposed in front of the main reflector;
A vehicular headlamp comprising a shade that partially shields the reflected light from the main reflector behind the projection lens,
The main reflector partially includes a second reflector having a substantially ellipsoidal shape having a focal point of the projection lens as a first focal point and a second focal point between the light source and the shade;
A vehicle headlamp comprising a third reflector that reflects light from the light source to the second reflector.   The vehicle headlamp according to claim 1, wherein the third reflector is rotatable around the vicinity of the second focal point.   3. The vehicle headlamp according to claim 2, wherein the third reflector forms a condensing optical system by condensing reflected light in the vicinity of the second focal point when the motorway is running. 3. The vehicle headlamp according to claim 2, wherein the third reflector collects reflected light at a position deviated from the second focal point during normal traveling to constitute a diffusion optical system. 4.

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