JP5618312B2 - Vehicle headlamp - Google Patents

Description

  The present invention relates to a so-called projector-type vehicle headlamp, and particularly to a vehicle headlamp provided with a movable shade.

  In general, a projector-type vehicle headlamp has a projection lens disposed on an optical axis extending in the longitudinal direction of the vehicle, and a light source disposed behind the rear focal point. The reflector is configured to reflect near the optical axis. When a low beam light distribution pattern is formed by the projector-type vehicle headlamp, the reflector is provided with a shade arranged so that the upper edge is positioned near the optical axis near the rear focal point of the projection lens. A part of the reflected light from the light is shielded to form a predetermined cut-off line at the upper end of the low beam light distribution pattern.

  In “Patent Document 1” and “Patent Document 2”, as a shade in such a projector-type vehicle headlamp, there is a light-shielding position in which the upper edge is positioned near the optical axis near the rear focal point of the projection lens. There is described a plate-like movable shade configured to be able to move from the light shielding position to a light shielding mitigation position that reduces the amount of shielding of reflected light from the reflector.

  Further, “Patent Document 3” describes a plate-like shade in which an upper end edge is disposed so as to pass a rear focal point of a projection lens, and a flat portion extending forward from the upper end edge is described. . In the vehicle headlamp described in “Patent Document 3”, a part of the reflected light from the reflector is reflected upward by the flat portion of the shade and emitted as upward light from the projection lens. Thus, a light distribution pattern for irradiating an overhead sign on the road surface ahead of the vehicle is formed.

Japanese Patent Laid-Open No. 62-195802 JP 2003-257218 A Japanese Utility Model Publication No. 5-66806

  From the viewpoint of improving the distance visibility when the vehicle is traveling with a high beam, it is desirable to make the central luminous intensity of the high beam light distribution pattern as high as possible.

  However, the conventional projector-type vehicle headlamp has the following problems in this case.

  That is, as described in the above-mentioned “Patent Document 1” and “Patent Document 2”, when the beam is switched between the low beam and the high beam by moving the movable shade, the high beam light distribution pattern is: The light distribution pattern for the low beam is superposed with the light distribution pattern formed by the light whose shielding is released when the movable shade moves to the light shielding mitigation position. For this reason, if the central luminous intensity of the high beam light distribution pattern is increased, the central luminous intensity of the low beam light distribution pattern is increased accordingly. Therefore, there is a problem that the central luminous intensity of the high beam light distribution pattern cannot be increased without increasing the central luminous intensity of the low beam light distribution pattern more than necessary.

  On the other hand, if a shade as described in the above “Patent Document 3” is used as the movable shade, in the state where the movable shade is in the light shielding position, a part of the reflected light from the reflector is part of the movable shade. Since the light is reflected upward in the flat portion extending forward from the upper end edge, the central luminous intensity of the low beam light distribution pattern can be lowered accordingly.

  However, such a configuration is still insufficient for effectively reducing the central luminous intensity of the low beam light distribution pattern. Further, in such a configuration, since the direction of the reflected light from the reflector is merely inverted up and down at the flat portion of the shade, the light distribution pattern formed by the upward emitted light from the projection lens is low beam distribution. It spreads upward from the cut-off line of the optical pattern. Therefore, there is a possibility that glare may be given to an oncoming vehicle driver or the like by the light distribution pattern for irradiating the overhead sign.

  The present invention has been made in view of such circumstances, and in a projector-type vehicle headlamp equipped with a movable shade, the central luminous intensity of the low beam light distribution pattern is not increased more than necessary. An object of the present invention is to provide a vehicular headlamp capable of increasing the central luminous intensity of a high beam light distribution pattern without giving glare to an oncoming vehicle driver or the like.

  The present invention is intended to achieve the above object by devising the configuration of the movable shade.

That is, the vehicle headlamp according to the present invention is
A projection lens disposed on the optical axis extending in the vehicle front-rear direction, a light source disposed rearward of the rear focal point of the projection lens, and light from this light source is reflected toward the optical axis toward the front. And a movable shade configured to shield a part of the reflected light from the reflector, and the movable shade has an upper edge passing through the vicinity of the rear focal point of the projection lens. A vehicle headlamp comprising: a light-shielding position disposed between the light-shielding position and an actuator that moves between the light-shielding position and a light-shielding relaxation position that reduces a shielding amount with respect to reflected light from the reflector.
In a state where the movable shade is in the light shielding position,
The portion located in the vicinity of the optical axis in the movable shade is formed as a thick portion,
The upper end surface of the thick portion has a concave curved cross section in a vertical plane parallel to the optical axis,
The rear focal point of the projection lens is located between the front edge and the rear edge on the upper end surface of the thick part,
The front edge of the upper end surface of the thick portion is formed so as to pass through the optical axis.

  The type of the “light source” is not particularly limited, and for example, a light emitting part of a discharge bulb, a filament of a halogen bulb, or the like can be employed.

  As long as the above-mentioned “concave curved cross-sectional shape” is a cross-sectional shape that protrudes downward as a whole, it may be a cross-sectional shape constituted only by a concave curve, or a partially uneven cross-sectional shape. It may be.

  The “thick part” may be formed as a thick part for other parts as long as at least a part located in the vicinity of the optical axis in the movable shade is formed as a thick part. It does not have to be.

  The above-mentioned “front edge at the upper end surface of the thick part” is not particularly limited as long as it is formed so as to pass through the optical axis, and the cut-off line of the light distribution pattern for low beam is not particularly limited. It is possible to set appropriately according to the shape.

  As shown in the above configuration, the vehicle headlamp according to the present invention is configured as a projector-type vehicle headlamp provided with a movable shade. The portion located in the vicinity of the optical axis is formed as a thick portion, and since the rear focus of the projection lens is located between the front end edge and the rear end edge on the upper end surface of the thick portion, Compared with the case where it is formed like a plate like the conventional movable shade, it is possible to block a large amount of reflected light from the reflector toward the vicinity of the rear focal point of the projection lens. At that time, the upper end surface of the thick portion has its front edge positioned in front of the rear focal point of the projection lens, and its rear edge positioned rearward of the rear focal point of the projection lens. Both the reflected light from the region above the optical axis and the reflected light from the region below the optical axis on the reflecting surface of the reflector can be shielded with respect to the light toward the rear focal point of the projection lens. .

  The reflected light from the reflector toward the vicinity of the rear focal point of this projection lens becomes light that contributes to the central luminous intensity of the low beam light distribution pattern. Can be kept low accordingly. For this reason, even when the reflecting surface of the reflector is formed to increase the central luminous intensity of the high beam light distribution pattern, the central luminous intensity of the low beam light distribution pattern is prevented from becoming higher than necessary. can do.

  At this time, the upper end surface of the thick portion in the movable shade has a concave curved cross section in a vertical plane parallel to the optical axis, and therefore the following operational effects can be obtained.

  In other words, if the upper end surface of the thick portion of the movable shade is formed as a flat surface, the light reflected from the rear focal point of the rear focal point of the projection lens on the upper end surface is light downward from the projection lens. However, the light reflected from the front area is emitted as upward light from the projection lens and becomes light that spreads upward from the cut-off line of the low beam light distribution pattern. Will be given.

  In that respect, in the present invention, the upper end surface of the thick wall portion has a concave curved cross-sectional shape in a vertical plane parallel to the optical axis, so that the front region is a curved surface inclined backward. . For this reason, the light reflected by the front region can be hardly incident on the projection lens. As a result, it is possible to effectively suppress the generation of glare light spreading upward from the cut-off line of the low beam light distribution pattern.

  On the other hand, the rear region on the upper end surface of the thick wall portion is a curved surface that is inclined forward. Therefore, by setting the inclined curved surface to an appropriate shape, the light reflected from the rear region is controlled as a projection lens. And can be emitted as controlled upward light from the projection lens. Thus, it is possible to easily form a light distribution pattern suitable for irradiating an overhead sign on the road surface ahead of the vehicle above the cutoff line in the low beam light distribution pattern.

  Moreover, in this invention, since the front-end edge in the upper end surface of a thick part is formed so that an optical axis may be passed, the following effects can be obtained.

  That is, the above-mentioned conventional movable shade is arranged so that the upper end edge thereof passes through the rear focal point of the projection lens, so that the cut-off line of the low beam light distribution pattern is clearly formed. On the other hand, in the present invention, the upper end surface of the thick portion of the movable shade is not disposed so as to pass through the rear focal point of the projection lens. However, in the present invention, since the front end edge of the upper end surface of the thick wall portion is formed so as to pass through the optical axis, the light from the reflection area located at substantially the same height as the optical axis on the reflection surface of the reflector. Can be used as light for forming the cut-off line, it is possible to sufficiently ensure the sharpness of the cut-off line.

  As described above, according to the present invention, in the projector-type vehicle headlamp provided with the movable shade, the central luminous intensity of the low beam light distribution pattern is not increased more than necessary, and glare is generated on the driver of the oncoming vehicle. The central luminous intensity of the high-beam light distribution pattern can be increased without giving the light. And thereby, distance visibility with a high beam can be improved.

  In the above configuration, if the rear end edge on the upper end surface of the thick part is formed at substantially the same height as the front end edge on the upper end surface of the thick part, the rear end edge can also be formed as a cut-off line. This makes it possible to further increase the sharpness of the cut-off line.

  If the deepest part on the upper end surface of the thick part is positioned forward of the rear focus of the projection lens, the inclination angle of the front region located on the front side of the deepest part of the upper end surface is Since it becomes large, it becomes easier to prevent the light reflected by this front region from entering the projection lens. In addition, since it is possible to ensure a large area of the rear region located on the rear side of the deepest portion in the upper end surface of this thick portion, it becomes possible to finely control the reflected light from this rear region, This makes it easier to form a light distribution pattern suitable for irradiating an overhead marker.

Side sectional view which shows the vehicle headlamp which concerns on one Embodiment of this invention Detailed view of the main part of FIG. The perspective view which shows the principal part of the said vehicle headlamp Detail view of part IV in Fig. 2 The figure which shows transparently the light distribution pattern formed on the virtual vertical screen arrange | positioned in the position of the lamp front 25m with the light irradiated ahead from the said vehicle headlamp

  Hereinafter, embodiments of the present invention will be described 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 according to the present embodiment is configured as a projector-type lamp unit, and is used in a state of being incorporated in a lamp body or the like (not shown).

  The vehicle headlamp 10 includes a light source bulb 12, a reflector 14, a holder 16, a projection lens 18, a movable shade 20, and an actuator 22, and has an optical axis Ax extending in the vehicle front-rear direction. doing. However, the vehicle headlamp 10 is arranged in a state in which the optical axis Ax extends in a downward direction by about 0.5 to 0.6 ° with respect to the vehicle front-rear direction when the aiming adjustment is completed. It is like that.

  The projection lens 18 is a planoconvex aspheric lens having a convex front surface and a flat rear surface, and is disposed on the optical axis Ax. The projection lens 18 converts the light source image formed on the rear focal plane (that is, the focal plane including the rear focal point F of the projection lens 18) as an inverted image on the vertical virtual screen arranged in front of the lamp. Projected.

  The light source bulb 12 is a discharge bulb such as a metal halide bulb having a discharge light emitting portion as the light source 12a, and is inserted and fixed from the rear side to an opening portion 14b formed at the rear top portion of the reflector 14. The light source 12 a of the light source bulb 12 is configured as a line light source extending substantially coaxially with the optical axis Ax, and is disposed on the rear side of the rear focal point F of the projection lens 18.

  The reflector 14 has a reflecting surface 14a that reflects light from the light source 12a forward and toward the optical axis Ax. The cross-sectional shape along the plane including the optical axis Ax of the reflecting surface 14a is set to be substantially elliptical, and the eccentricity is set to gradually increase from the vertical cross section toward the horizontal cross section. As a result, the light from the light source 12a reflected by the reflecting surface 14a is substantially converged to the vicinity of the rear focal point F in the vertical section, and the convergence position is set to the front side of the rear focal point F in the horizontal section. It is supposed to be displaced.

  At this time, a boundary portion between the upper reflection area 14a1 located above the optical axis Ax and the lower reflection area 14a2 located below the optical axis Ax (that is, substantially the same as the optical axis Ax). The reflection regions on both the left and right sides of the opening 14b, which are located at a height, are formed so as to improve the convergence of the reflected light to the rear focal point F in the vertical direction. The lower reflection region 14a2 is formed so as to improve the convergence of the reflected light to the rear focal point F in the vertical direction and the horizontal direction.

  The holder 16 is formed so as to extend in a substantially cylindrical shape from the front end opening of the reflector 14 toward the front. The holder 16 fixes and supports the reflector 14 at the rear end, and also supports the projection lens 18 at the front end. ing. The lower region of the holder 16 is cut away.

  The movable shade 20 is provided so as to be positioned in a substantially lower half portion in the internal space of the holder 16, and is supported at the lower end portion thereof by the holder 16 via a rotation pin 24 extending in the left-right direction. ing. The movable shade 20 can adopt a light-shielding position indicated by a solid line in the figure and a light-shielding relaxation position indicated by a two-dot chain line in the figure rotated by a predetermined angle from the light-shielding position to the rear side. Yes.

  FIG. 2 is a detailed view of a main part of FIG. FIG. 3 is a perspective view showing a main part of the vehicle headlamp 10.

  As shown in these figures, the movable shade 20 is formed with a thick portion 20A at a portion located near the optical axis Ax when in the light shielding position. At this time, the thickness of the thick portion 20A is set to about 6 to 10 mm (for example, about 8 mm). On the other hand, the thickness of the general portion 20B (that is, the portion other than the thick portion 20A) in the movable shade 20 is set to about 1 to 5 mm (for example, about 3 mm). The left and right end portions of the thick portion 20A are formed so that the thickness gradually decreases toward the general portion 20B.

  The movable shade 20 is arranged so that the rear focal point F of the projection lens 18 is located between the front end edge 20Aa1 and the rear end edge 20Aa2 of the upper end surface 20Aa of the thick portion 20A in a state where the movable shade 20 is in the light shielding position. Has been. In the present embodiment, the rear focal point F of the projection lens 18 is positioned approximately at the center between the front edge 20Aa1 and the rear edge 20Aa2.

  The thick portion 20A has an upper end surface 20Aa having a concave curved cross section in a vertical plane parallel to the optical axis Ax. The upper end surface 20Aa is subjected to a mirror surface treatment such as aluminum vapor deposition.

  The front end edge 20Aa1 of the upper end surface 20Aa of the thick part 20A is formed in a stepped manner so as to pass through the optical axis Ax. That is, the area on the own lane side in the front edge 20Aa1 (that is, the area on the left side of the optical axis Ax) extends horizontally from the optical axis Ax, and the area on the opposite lane side in the front edge 20Aa1 is the optical axis Ax. After extending diagonally downward from, it extends horizontally.

  The rear end edge 20Aa2 on the upper end surface 20Aa of the thick portion 20A is formed in a step difference that is substantially the same height as the front end edge 20Aa1.

  Note that the upper end surface 20Ba of the general portion 20B of the movable shade 20 is formed in a planar shape.

  FIG. 4 is a detailed view of a portion IV in FIG.

  As shown in the figure, the deepest portion 20Aa3 of the upper end surface 20Aa of the thick portion 20A in the movable shade 20 is located in front of the rear focal point F of the projection lens 18.

  In the upper end surface 20Aa, the front region 20AaF positioned on the front side of the deepest portion 20Aa3 is formed as a concave curved surface having a substantially arc-shaped cross section from the front end edge 20Aa1 to the deepest portion 20Aa3. On the other hand, in the upper end surface 20Aa, the rear region 20AaR located on the rear side of the deepest portion 20Aa3 extends from the rear edge 20Aa2 to the deepest portion 20Aa3. A concave curved surface having a substantially arc-shaped cross section is formed as a curved surface smoothly connected in this order.

  The left and right end portions of the upper end surface 20Aa of the thick wall portion 20A are formed so as to gradually shift from a concave curved surface to a flat surface toward the upper end surface 20Ba of the general portion 20B formed in a flat shape.

  As shown in FIG. 1, when the movable shade 20 is in the light-shielding position, the upper end surface 20Aa is disposed so as to pass below the rear focal point F of the projection lens 18, and thereby, from the reflecting surface 14a of the reflector 14. A part of the reflected light is blocked and most of the upward light emitted forward from the projection lens 18 is removed. On the other hand, when the movable shade 20 moves from the light shielding position to the light shielding mitigation position, the upper end surface 20Aa is displaced obliquely downward toward the rear, and the amount of shielding against the reflected light from the reflecting surface 14a is reduced. . In the present embodiment, the shielding amount with respect to the reflected light from the reflecting surface 14a is made substantially zero at the light-shielding relaxation position.

  The actuator 22 is composed of a solenoid having a plunger 22 a extending in the front-rear direction, and is fixed to a mounting portion 14 c formed at the lower end portion of the reflector 14. The plunger 22a of the actuator 22 is engaged with a stay 20Bb formed so as to protrude downward from the movable shade 20 at the tip end portion thereof, thereby reciprocating the plunger 22a in the front-rear direction. It is transmitted as a rotational movement. The actuator 22 is driven when a beam changeover switch (not shown) is operated to move the plunger 22a in the front-rear direction, thereby moving the movable shade 20 between the light shielding position and the light shielding relaxation position. It is like that.

  In FIG. 2, the case where the optical path of the light emitted from each position on the light source 12a is reflected at a point located obliquely above and behind the light source 12a on the reflecting surface 14a of the reflector 14 is shown.

  As shown by the hatched lines in the figure, the reflected light spreads forward and obliquely downward with an extent corresponding to the longitudinal length of the light source 12 a, approximately half of which reaches the projection lens 18 as it is, and the rest reaches the movable shade 20. . Of the light reaching the movable shade 20, the light reaching the upper end surface 20Aa is reflected upward by the upper end surface 20Aa.

  At this time, the front region 20AaF of the upper end surface 20Aa is formed as a concave curved surface having a substantially arc-shaped cross section from the front end edge 20Aa1 to the deepest portion 20Aa3, and is a curved surface inclined backward. The light reaching 20AaF is reflected by the front region 20AaF and becomes upward light at a large angle. For this reason, the light reflected by the front region 20AaF does not enter the projection lens 18.

  On the other hand, the rear region 20AaR of the upper end surface 20Aa has a concave curved surface having a substantially arc-shaped cross section, a convex curved surface having a substantially arc-shaped cross section, and a concave curved surface having a substantially arc-shaped cross section from the rear edge 20Aa2 to the deepest portion 20Aa3. Since the curved surface is smoothly connected in order, a part of the light reaching the rear region 20AaR is reflected by the rear region 20AaR and becomes a small angle upward light, and is near the lower side of the rear focal point F. The light is incident on the projection lens 18 so as to pass through, and the remaining light becomes light traveling in a direction not incident on the projection lens 18.

  FIG. 5 is a perspective view showing a light distribution pattern formed on a virtual vertical screen arranged at a position 25 m ahead of the lamp by light irradiated forward from the vehicle headlamp 10. (A) shows the low beam distribution pattern PL, and (b) shows the high beam distribution pattern PH.

  The low beam light distribution pattern PL is a light distribution pattern formed when the movable shade 20 is in the light shielding position, and the high beam light distribution pattern PH is formed when the movable shade 20 is in the light shielding relaxation position. It is a light distribution pattern. When the movable shade 20 is in the light shielding position, the additional light distribution pattern PA is formed together with the low beam light distribution pattern PL.

  A low beam light distribution pattern PL shown in FIG. 5A is a left light distribution light beam distribution pattern, and has upper and lower cut-off lines CL1 and CL2 at its upper edge. The cut-off lines CL1 and CL2 extend in the horizontal direction at the left and right steps with the VV line passing through the HV, which is a vanishing point in the front direction of the lamp, in the vertical direction, and are on the right side of the VV line. The opposite lane side portion is formed as a lower horizontal cut-off line CL1, and the left lane side portion on the left side of the V-V line is raised from the lower horizontal cut-off line CL1 through an inclined portion via an inclined portion. It is formed as offline CL2.

  In this low-beam light distribution pattern PL, the elbow point E, which is the intersection of the lower horizontal cut-off line CL1 and the VV line, is located about 0.5 to 0.6 ° below HV. This is because the optical axis Ax of the lamp unit 20 extends in a downward direction by about 0.5 to 0.6 ° with respect to the vehicle longitudinal direction. In the low beam light distribution pattern PL, a hot zone HZL which is a high luminous intensity region is formed so as to surround the elbow point E.

  The low-beam light distribution pattern PL is obtained by converting the image of the light source 12a formed on the rear focal plane of the projection lens 18 by the light from the light source 12a reflected by the reflection surface 14a of the reflector 14 by the projection lens 18 to the virtual vertical direction. The cut-off lines CL1 and CL2 are formed by projecting the image as a reverse projection image on the screen, and the upper end edges of the movable shade 20 (in this embodiment, the upper end face 20Aa of the thick part 20A and the upper end face of the general part 20B). 20Ba) as a reverse projection image.

  At that time, the main parts of the cut-off lines CL1, CL2 are formed by the front end edge 20Aa1 on the upper end face 20Aa of the thick part 20A. The front end edge 20Aa1 is located in front of the rear focal plane, but the reflected light from the reflection region located at substantially the same height as the optical axis Ax on the reflection surface 14a is reflected from the rear focus F in the vertical direction. Therefore, the sharpness of the cut-off lines CL1 and CL2 is sufficiently maintained.

  Further, since the rear end edge 20Aa2 of the upper end surface 20Aa of the thick portion 20A is formed at substantially the same height as the front end edge 20Aa1, the rear end edge 20Aa2 also contributes to the formation of the cut-off lines CL1 and CL2. It will be.

  In this case, since the front end edge 20Aa1 forms the cut-off lines CL1 and CL2 by the reflected light from the upper reflection region 14a1, the cut-off lines CL1 and CL2 appear to be bluish only by the front end edge 20Aa1 due to chromatic aberration. It will end up. On the other hand, the rear edge 20Aa2 forms the cut-off lines CL1 and CL2 by the reflected light from the lower reflection region 14a2, so that the cut-off lines CL1 and CL2 have a reddish appearance due to chromatic aberration. Therefore, not only the front end edge 20Aa1 but also the rear end edge 20Aa2 contributes to the formation of the cut-off lines CL1 and CL2, thereby canceling the influence of chromatic aberration and making the cut-off lines CL1 and CL2 appear bluish. It comes to prevent.

  The additional light distribution pattern PA shown in FIG. 5A is formed as a horizontally long light distribution pattern at a position distant upward from the cutoff lines CL1 and CL2 in the low beam light distribution pattern PL.

  This additional light distribution pattern PA is a light distribution pattern for irradiating an overhead sign (that is, an overhead sign) OHS in front of the vehicle traveling path, and in the rear region 20AaR of the upper end surface 20Aa of the thick portion 20A in the movable shade 20. It is formed by obliquely upward light that is reflected and emitted forward from the projection lens 28.

  On the other hand, the high-beam light distribution pattern PH shown in FIG. 5B is formed so as to expand to some extent upward from the cut-off lines CL1 and CL2 with respect to the low-beam light distribution pattern PL. It has a hot zone HZH.

  At that time, since the lower reflection region 14a2 on the reflection surface 14a of the reflector 14 is formed so as to improve the convergence of the reflected light to the rear focal point F, the central luminous intensity of the hot zone HZH is considerably high. It has become.

  As described in detail above, the vehicle headlamp 10 according to the present embodiment is configured as a projector-type vehicle headlamp including the movable shade 20, and the movable shade 20 is located at the light shielding position. In a certain state, a portion located in the vicinity of the optical axis Ax is formed as a thick portion 20A, and the projection lens 18 is formed between the front end edge 20Aa1 and the rear end edge 20Aa2 on the upper end surface 20Aa of the thick portion 20A. Since the rear focal point F is located, compared with the case where the rear focal point F is formed like a plate like the conventional movable shade 20, the rear focal point F is closer to the vicinity of the rear focal point F of the projection lens 18. A large amount of reflected light can be blocked. At that time, the upper end surface 20Aa of the thick portion 20A has the front end edge 20Aa1 positioned in front of the rear focal point F of the projection lens 18 and the rear end edge 20Aa2 from the rear focal point F of the projection lens 18. Since the light reflected from the upper reflective area 14a1 and the reflected light from the lower reflective area 14a2 on the reflective surface 14a of the reflector 14 are also directed to the vicinity of the rear focal point F of the projection lens 18, This can be shielded.

  The reflected light from the reflector 14 that is directed to the vicinity of the rear focal point F of the projection lens 18 becomes light that contributes to the central luminous intensity of the low beam light distribution pattern PL. The central luminous intensity of the pattern PL can be suppressed by that much. For this reason, although the lower reflection region 14a2 on the reflection surface 14a of the reflector 14 is formed so as to increase the central luminous intensity of the high beam light distribution pattern PH, the central luminous intensity of the low beam light distribution pattern PL is It can be prevented from becoming higher than necessary.

  At this time, the upper end surface 20Aa of the thick portion 20A in the movable shade 20 has a concave curved cross-sectional shape in a vertical plane parallel to the optical axis Ax, so that the following operational effects can be obtained. it can.

  That is, assuming that the upper end surface 20Aa of the thick portion 20A in the movable shade 20 is formed as a flat surface, the light reflected in the region on the rear side of the rear focal point F of the projection lens 18 on the upper end surface 20Aa is The light emitted from the projection lens 18 as downward light, but the light reflected by the area in front of the projection lens 18 is emitted as upward light from the projection lens 18 and upward from the cutoff lines CL1 and CL2 of the low beam light distribution pattern PL. Since the light spreads, glare is given to the driver of the oncoming vehicle.

  In this respect, in the present embodiment, the upper end surface 20Aa of the thick portion 20A has a concave curved cross-sectional shape in a vertical plane parallel to the optical axis Ax, so that the front region 20AaF faces backward. It becomes an inclined curved surface. For this reason, the light reflected by the front region 20AaF can be hardly incident on the projection lens 18. As a result, it is possible to effectively suppress the generation of glare light that spreads upward from the cut-off lines CL1 and CL2 of the low-beam light distribution pattern PL.

  On the other hand, since the rear region 20AaR on the upper end surface 20Aa of the thick wall portion 20A is a curved surface inclined forward, the light reflected by the rear region 20AaR is controlled by setting the inclined curved surface to an appropriate shape. The light can enter the projection lens 18 and can be emitted as controlled upward light from the projection lens 18. As a result, it is possible to easily form the additional light distribution pattern PA suitable for irradiating the overhead sign OHS on the road surface ahead of the vehicle above the cutoff lines CL1 and CL2 in the low beam light distribution pattern PL.

  In the present embodiment, since the front end edge 20Aa1 of the upper end surface 20Aa of the thick portion 20A is formed so as to pass through the optical axis Ax, the following operational effects can be obtained.

  That is, in the present embodiment, the upper end surface 20Aa of the thick portion 20A of the movable shade 20 is disposed so as to pass near the lower side of the rear focal point F of the projection lens 18, and passes through the rear focal point F. Is not arranged. However, in the present embodiment, the front end edge 20Aa1 of the upper end surface 20Aa of the thick portion 20A is formed so as to pass through the optical axis Ax, and the height of the reflective surface 14a of the reflector 14 is substantially the same as the optical axis Ax. Since the light from the reflection region located at the same position is used as the light for forming the cut-off lines CL1 and CL2, the sharpness of the cut-off lines CL1 and CL2 can be sufficiently secured.

  As described above, according to the present embodiment, in the projector-type vehicle headlamp 10 including the movable shade 20, the center luminous intensity of the low beam light distribution pattern PL is not increased more than necessary, and the oncoming vehicle The central luminous intensity of the high beam distribution pattern PH can be increased without giving glare to the driver or the like. And thereby, distance visibility with a high beam can be improved.

  In addition, in the present embodiment, the rear end edge 20Aa2 on the upper end surface 20Aa of the thick portion 20A is formed at substantially the same height as the front end edge 20Aa1, and therefore the rear end edges 20Aa2 are also cut off lines CL1, CL2. Therefore, the sharpness of the cut-off lines CL1 and CL2 can be further increased.

  In particular, since the light source 12a of the vehicle headlamp 10 according to the present embodiment is a discharge light emitting part of a discharge bulb, the cut-off lines CL1 and CL2 appear bluish by adopting such a configuration. Can be prevented beforehand.

  That is, the front end edge 20Aa1 on the upper end surface 20Aa of the thick wall portion 20A forms the cut-off lines CL1 and CL2 by the reflected light from the upper reflection region 14a1, and therefore, only the front end edge 20Aa1 has a cut-off line CL1 due to chromatic aberration. , CL2 will appear bluish. On the other hand, the rear edge 20Aa2 forms the cut-off lines CL1 and CL2 by the reflected light from the lower reflection region 14a2, so that the cut-off lines CL1 and CL2 are reddish due to chromatic aberration. Therefore, not only the front end edge 20Aa1 but also the rear end edge 20Aa2 contributes to the formation of the cut-off lines CL1 and CL2, so that the influence of chromatic aberration can be offset, thereby making the cut-off lines CL1 and CL2 appear bluish. Can be prevented beforehand.

  In the present embodiment, since the deepest portion 20Aa3 of the upper end surface 20Aa of the thick portion 20A is located in front of the rear focal point F of the projection lens 18, the following operational effects can be obtained. it can.

  That is, the front region 20AaF located on the front side of the deepest portion 20Aa3 in the upper end surface 20Aa has a large inclination angle, so that the light reflected by the front region 20AaF is not incident on the projection lens 18. It becomes possible more easily. Further, since the rear region 20AaR located on the rear side of the deepest portion 20Aa3 on the upper end surface 20Aa of the thick wall portion 20A can secure a large area, the control of the reflected light from the rear region 20AaR can be controlled. Accordingly, it is possible to form a light distribution pattern suitable for irradiating an overhead marker.

  Specifically, in the present embodiment, the rear region 20AaR of the upper end surface 20Aa extends from the rear end edge 20Aa2 to the deepest portion 20Aa3, a concave curved surface having a substantially arcuate cross section, a convex curved surface having a substantially arcuate cross section, and a cross section. Since the substantially arc-shaped concave curved surface is a curved surface smoothly connected in this order, a part of the light reaching the rear region 20AaR is reflected as a small angle upward light by the rear region 20AaR, The light can be incident on the projection lens 18 so as to pass near the lower side of the rear focal point F, and the remaining light can be directed to a direction not incident on the projection lens 18.

  In addition, the numerical value shown as a specification in the said embodiment is only an example, and of course, you may set these to a different value suitably.

  Further, in the above embodiment, the case where the left light distribution pattern for low beam distribution PL is formed has been described. However, even in the case where the right light distribution pattern for low beam distribution is formed, the same configuration as in the above embodiment is used. By adopting, it is possible to obtain the same operational effects as the above embodiment.

DESCRIPTION OF SYMBOLS 10 Vehicle headlamp 12 Light source bulb 12a Light source 14 Reflector 14a Reflective surface 14a1 Upper reflective area 14a2 Lower reflective area 14b Opening part 14c Mounting part 16 Holder 18 Projection lens 20 Movable shade 20A Thick part 20Aa Upper end face 20Aa2 Front end edge 20Aa2 Edge 20Aa3 Deepest part 20AaF Front part 20AaR Rear part 20B General part 20Ba Upper end 20Bb Stay 22 Actuator 22a Plunger 24 Rotating pin Ax Optical axis CL1 Lower horizontal cut-off line CL2 Upper horizontal cut-off line E Elbow point F Rear focus HZH HZL Hot zone PA Additional light distribution pattern PH High beam light distribution pattern PL Low beam light distribution pattern

Claims (3)

A projection lens disposed on the optical axis extending in the vehicle front-rear direction, a light source disposed rearward of the rear focal point of the projection lens, and light from this light source is reflected toward the optical axis toward the front. And a movable shade configured to shield a part of the reflected light from the reflector, and the movable shade has an upper edge passing through the vicinity of the rear focal point of the projection lens. A vehicle headlamp comprising: a light-shielding position disposed between the light-shielding position and an actuator that moves between the light-shielding position and a light-shielding relaxation position that reduces a shielding amount with respect to reflected light from the reflector.
In a state where the movable shade is in the light shielding position,
The portion located in the vicinity of the optical axis in the movable shade is formed as a thick portion,
The upper end surface of the thick portion has a concave curved cross section in a vertical plane parallel to the optical axis,
The rear focal point of the projection lens is located between the front edge and the rear edge on the upper end surface of the thick part,
A vehicular headlamp characterized in that a front end edge of an upper end surface of the thick portion is formed so as to pass through the optical axis.   The vehicular headlamp according to claim 1, wherein a rear end edge of the upper end surface of the thick portion is formed at substantially the same height as a front end edge of the upper end surface of the thick portion.   The vehicular headlamp according to claim 1, wherein a deepest portion of the upper end surface of the thick portion is positioned in front of a rear focal point of the projection lens.

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