JP2007214074A - Vehicle headlamp - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle headlamp formed so that remote visibility and visibility for the front of a vehicle are enhanced with a simple structure by changing a light distribution in the lower part lower than a cutoff line. <P>SOLUTION: In this vehicle headlamp 10 equipped with a light source 11, a reflecting surface 12, a projection lens 13, and a light shading member 14 to define the cutoff line, the light shading member includes a movable part capable of moving in an optical axis direction by a moving means. The vehicle headlamp 10 is structured so that the center of a concave mirror recessed backward and integrally mounted to the light source side of this movable part is positioned near the light source, when the movable part is at its insertion position. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a projector-type vehicle headlamp that is used, for example, as a headlamp or an auxiliary headlamp provided at the front of an automobile.

  Conventionally, such a vehicle headlamp is configured, for example, as shown in FIG. That is, in FIG. 7, the vehicle headlamp 1 includes a bulb 2 as a light source, a reflecting surface 3, a projection lens 4, and a light shielding member 5.

The reflective surface 3 is composed of an elliptical reflective surface having the bulb 2 as the first focal point (rear focal point) and the major axis extending substantially horizontally toward the front, and its inner surface is formed as a reflective surface. Yes.
Here, the elliptical reflecting surface includes not only a spheroid and an elliptic cylinder but also a free-form surface based on an ellipsoid.

  The projection lens 4 is composed of a convex lens, and the focal point on the light source side (rear side) is arranged in the vicinity of the second focal position of the reflecting surface 3. The projection lens 4 collects light traveling forward from the bulb 2 or the reflecting surface 3 and irradiates the light forward.

  The light shielding member 5 gives a predetermined light distribution pattern for a low beam to the light irradiated toward the front. The light shielding member 5 is disposed in the vicinity of the second focal position of the reflecting surface 3, and its upper edge 5a is formed in a predetermined shape in order to form a cut-off line in the light distribution pattern.

According to the vehicle headlamp 1 having such a configuration, when the bulb 2 is supplied with power and emits light, the light emitted from the bulb 2 is reflected directly or by the reflection surface 3, and the reflection surface 3. Proceed forward toward near the second focal point. This light is irradiated forward while being focused by the projection lens 4.
At that time, a part of the light irradiated forward is blocked by the light shielding member 5, and a cut-off line is formed by the upper edge 5 a of the light shielding member 5, and is irradiated forward as a passing beam. Will be.

  As a result, as shown in FIG. 8, the cut-off line is projected by the projection lens 5, so that with respect to the light distribution pattern, on the opposite vehicle side from the center (right side), slightly below the horizontal line, A cut-off line C extending horizontally along the horizontal line is formed on the vehicle side (left side) from the center, and light suitable for the passing beam is irradiated only on the lower side of the cut-off line C. It has become.

  In this way, in such a vehicle headlamp 1, in the case of a passing beam, a light distribution pattern for the passing beam is formed by forming the cut-off line C by the light shielding member 5. It has become.

By the way, in the vehicle headlamp 1 described above, the light distribution pattern for the passing beam by the cut-off line C is constant.
On the other hand, in recent years, vehicle headlamps with a variable light distribution function have been recognized as AFS, and the traveling direction can be visually confirmed by moving the optical axis from the front to the left or right during curve driving. Automobiles equipped with vehicle headlamps designed to improve performance have already been sold.
As a method of moving the optical axis, there is a method in which the light shielding member or shade that defines the cut-off line is swung horizontally, a part of the reflecting surface is swung, or a dedicated light source is separately turned on. .

However, for example, distant visibility is important when traveling on a highway, or visibility in a relatively near area is important when traveling on a city.
In order to realize such distant visibility when traveling on an expressway and visibility before the vehicle when traveling on an urban area, vehicle headlamps according to Patent Documents 1 to 4 are disclosed.

  In the vehicle headlamp according to Patent Document 1, as shown in FIG. 9, the light blocking member 5 is arranged so as to be movable in the vertical direction, and when traveling on a highway, as shown in FIG. It is made to ensure far visibility by making it raise.

Moreover, in the vehicle headlamp according to Patent Document 2, as shown in FIG. 11, two light shielding members 5b and 5c having different heights are prepared, and these light shielding members 5b and 5c extend in the lateral direction. It is attached around the horizontal rotating shaft 5d.
By rotating the horizontal rotation shaft 5d, each light blocking member 5b or 5c is brought to a predetermined position, and the position of the upper edge of the light blocking member 5 is switched.
Thus, when traveling on a highway, as shown in FIG. 11, by inserting the light shielding member 5c having a lower upper edge into a predetermined position, the cut-off line C1 is slightly changed as shown in FIG. And is configured to ensure distant visibility.

Further, in the vehicle headlamp according to Patent Document 3, the light reflected by the movable reflector disposed above the optical axis is reflected by a plurality of additional reflectors disposed below the optical axis and having different optical characteristics. The light is selectively incident on each of them, and the light reflected by these additional reflectors is reflected forward without going through the projection lens.
Thereby, by moving the said movable reflector according to the driving | running | working condition etc. of a vehicle, light is reflected toward the front by each additional reflector, and a light distribution pattern can be switched.

Further, in the vehicle headlamp according to Patent Document 4, the light that is reflected in the upper region of the reflecting surface and incident on the projection lens is allowed to pass or partially blocked by the movable shade disposed near the upper end of the reflecting surface. By doing so, the light distribution pattern in the region below the cut-off line is changed.
Actual Kaihei 07-036305 Japanese Patent No. 2861737 JP-A-2005-347127 JP-A-2005-347128

By the way, in the vehicle headlamps according to Patent Document 1 and Patent Document 2 described above, the cut-off line is slightly raised by moving the upper edge of the light shielding member slightly upward during traveling on the highway. Thereby, the far visibility is ensured by irradiating light toward the vicinity of the horizon.
However, in the vehicle headlamps according to Patent Document 1 and Patent Document 2 described above, the light distribution characteristics of the region corresponding to the area immediately below the cut-off line, that is, in front of the vehicle are changed when traveling on a highway and traveling in an urban area. I can't let you.
For this reason, the request | requirement of making the near side of a vehicle bright when driving | running a city area was not able to be satisfy | filled.

  Further, in the vehicle headlamp according to Patent Document 3, since the movable reflector and the additional reflector are respectively arranged above and below the vehicle headlamp, the number of parts increases and the size in the vertical direction increases. End up.

  Furthermore, in the vehicle headlamp according to Patent Document 4, since the movable shade needs to largely swing from the light shielding state through the dimming state to the light shielding release state, a relatively large swinging space for the movable shade is necessary. At the same time, the drive mechanism for swinging the movable shade becomes large.

  From the above points, the present invention changes the light distribution below the cut-off line with a simple configuration to improve distant visibility when traveling at high speeds, etc., and at a short distance from the vehicle when traveling in urban areas. It aims at providing the vehicle headlamp which improved visibility.

  According to the present invention, the above object is arranged such that the light source and the first focal position are located in the vicinity of the light source and the second focal position is located on the optical axis of the light source extending substantially horizontally from the light source. A concave elliptical reflecting surface, a convex projection lens whose focal position on the light source side is located near the second focal position of the reflecting surface, and an upper edge that reflects reflected light from the light source to the projection lens. A light shielding member which is formed so as to shield light and define a cut-off line, and which moves between an insertion position near the second focal position of the reflecting surface and a retracted position spaced from the second focal position; A concave mirror that is provided on the reflection direction side of the reflection surface and is movable between the insertion position and the retraction position, reflects light from the light source to the reflection surface, and inserts and removes the light shielding member and the concave mirror at the insertion position. A vehicle headlamp comprising a driving device for , The center of the concave mirror, when said light blocking member is in the insertion position by the vehicle headlamp in the vicinity of the light source is achieved.

  Further, according to the present invention, the first focal position is located in the vicinity of the light source and the second focal position is substantially forward so that the light from the light source and the light from the light source are reflected forward. An ellipsoidal reflecting surface that is concave toward the front and disposed so as to be positioned on the optical axis of the horizontally extending light source, and the focal point on the light source side on the optical axis of the light source in front of the reflecting surface. A convex projection lens disposed so that the position is located near the second focal position of the reflecting surface, and disposed near the second focal position of the reflecting surface, and the upper edge defines a cut-off line. In the vehicle headlamp, the light shielding member includes a movable part that is movable in the optical axis direction by the moving means, and the movable light shielding member is movable. A concave concave mirror is integrated on the light source side of the part. The concave mirror is formed such that when the movable part of the light shielding member is located near the second focal position (insertion position) of the reflecting surface, the center is located near the light source. When the movable part of the light shielding member is at the insertion position, a light distribution pattern having a high luminous intensity near the center is formed, and when the movable part of the light shielding member moves from the insertion position along the optical axis, This is achieved with a vehicle headlamp, characterized in that a diffused light distribution pattern is formed.

  In the vehicle headlamp according to the present invention, preferably, the moving means moves the movable part of the light shielding member stepwise or continuously in the optical axis direction in accordance with the traveling speed of the automobile.

  In the vehicle headlamp according to the present invention, preferably, the light shielding member further includes a fixed portion fixed at an insertion position, and the movable portion is movable toward the light source side of the fixed portion.

  In the vehicle headlamp according to the present invention, preferably, the light shielding member further includes a second movable part on the projection lens side of the fixed part, and the second movable part is In conjunction with the movable part, the movable part can move in the opposite direction.

  In the vehicle headlamp according to the present invention, preferably, the moving means moves the movable part and / or the second movable part of the light shielding member and the concave mirror in the optical axis direction in accordance with the traveling state of the automobile.

  In the vehicle headlamp according to the present invention, preferably, the movable part and / or the second movable part of the light shielding member blocks light directed toward at least the opposite lane side of the automobile in the light distribution pattern.

  According to the above configuration, the light emitted from the light source is reflected directly or by the reflecting surface, converged toward the second focal position, and further irradiated forward through the projection lens.

Here, when traveling at a high speed or traveling on a straight road, the movable portion of the light shielding member is inserted in the vicinity of the second focal position of the reflecting surface in the optical path by the moving means.
Thereby, a part of the light incident on the projection lens from the reflecting surface is blocked by the movable part of the light shielding member. Thereby, a cut-off line slightly below the horizontal line is formed in the light distribution pattern of the irradiation light irradiated toward the front.
At this time, since the movable part of the light shielding member is positioned near the rear focal position of the projection lens, the upper edge of the movable part of the light shielding member is projected sharply slightly below the horizontal line, and is at the cut-off line position. A clear light / dark border will be formed. Therefore, no illusion light is given to oncoming vehicles or pedestrians.

In addition, light incident on the concave mirror attached to the light source side of the movable part of the light shielding member from the light source is reflected by the concave mirror, returned to the light source, and further reflected by the reflecting surface. This light is focused toward the second focal position, and then converged and irradiated in the vicinity of the center forward through the projection lens.
Therefore, the light conventionally blocked by the light shielding member is reflected by the concave mirror. The light passes through the upper side of the movable portion of the light shielding member and is irradiated toward the front center. For this reason, according to this invention, while using efficiency of the light from a light source improves, distance visibility improves.
In this way, in the present invention, the cut-off line is located slightly below the horizon, and the luminous intensity near the center is increased. For this reason, according to the present invention, the distance visibility is good, and an optimal light distribution pattern for high-speed traveling and straight traveling can be obtained.

On the other hand, the movable portion of the light shielding member is moved forward or backward in the optical axis direction by the moving means when traveling on an urban area or on a curved road. It will deviate from the rear focal position.
Thereby, part of the light incident on the projection lens from the reflecting surface is blocked by the movable part of the light shielding member, so that the movable part of the light shielding member is added to the light distribution pattern of the irradiation light irradiated forward. A cut-off line is formed by the projected image of the upper edge of the.
At this time, since the movable part of the light shielding member is deviated from the focal position on the rear side of the projection lens, the projected image of the upper edge of the movable part of the light shielding member, that is, the light / dark boundary line due to the cut-off line is blurred. As a result, a gentle luminous intensity gradient is provided at this light / dark boundary line, so that the visibility above the horizontal line is improved.

Further, light incident on the concave mirror attached to the light source side of the movable part of the light shielding member from the light source is reflected by the concave mirror. At this time, the center of the concave mirror deviates from the light source, so that the reflected light from the concave mirror is slightly diffused. Therefore, when the reflected light by the concave mirror is further reflected by the reflecting surface, it does not converge toward the second focal position, and passes forward through the projection lens through the upper side of the movable part of the light shielding member. Is irradiated.
At this time, since the reflected light from the concave mirror is slightly diffused with respect to the focused light toward the second focal position, it passes through the upper side of the movable part of the light shielding member and is irradiated further downward, that is, in front of the vehicle. Will be.

In this way, when traveling on an urban area or on a curved road, the movable part of the light shielding member moves forward or backward from the insertion position along the optical axis, so that the light reflected by the concave mirror is slightly diffused. Thereby, the luminous intensity of the area | region corresponding to the direction lower than the cut-off line in a light distribution pattern, ie, the vehicle front, can be raised.
In addition, blurring of the light / dark boundary line due to the cut-off line improves visibility near the light / dark boundary line, and brightening the front side of the vehicle improves visibility near the front of the vehicle. An optimal light distribution pattern for road driving and the like can be obtained.

  When the moving means moves the movable part of the light-shielding member stepwise or continuously in the optical axis direction corresponding to the traveling speed of the vehicle, the vehicle travels at a high speed when the vehicle is traveling at a high speed. A light distribution pattern suitable for the vehicle is formed, and when the traveling speed of the automobile decreases, the movable part of the light shielding member correspondingly shifts stepwise or continuously from the insertion position. A light distribution pattern suitable for running on a curved road or the like is formed.

  When the light shielding member further includes a fixed portion fixed at the insertion position, and the movable portion is movable to the light source side of the fixed portion, the movable portion of the light shielding member is lighted from the insertion position. Even when moving in the axial direction, a clear light / dark boundary line is formed by the upper edge of the fixed portion. Further, the light reflected on the upper surface of the fixed portion based on the thickness of the fixed portion in the optical axis direction forms a so-called overhead sign region in the light distribution pattern. Thereby, the visibility of the sign etc. which are located in the upper part ahead of vehicles can be secured, for example.

  The light shielding member further includes a second movable part on the projection lens side of the fixed part, and the second movable part is interlocked with the movable part by the moving means. When it is possible to move in the opposite direction, the two movable parts of the light shielding member move in the opposite directions in conjunction with each other, thereby canceling out chromatic aberration caused by deviation from the focal position of the projection lens. Become.

  When the moving means moves the movable part and / or the second movable part of the light shielding member and the concave mirror in the direction of the optical axis in accordance with the driving state of the automobile, the highway is based on road information, for example. Alternatively, an appropriate light distribution pattern can be formed while traveling on a general road.

  In the case where the movable part and / or the second movable part of the light shielding member blocks light directed to at least the opposite lane side of the automobile in the light distribution pattern, the light distribution pattern on the opposite lane side determines the traveling speed of the automobile, Since it changes according to the driving state, no illusion light is given to the oncoming vehicle.

Thus, according to the present invention, the movable portion of the light shielding member is moved to the insertion position near the rear focal position of the projection lens, whereby the cut-off line in the light distribution pattern is formed sharply, and the light shielding member is movable. The light from the light source is reflected and focused by a concave mirror provided on the light source side of the portion, and the focused light is irradiated near the center of the light distribution pattern, thereby increasing the luminous intensity near the center.
Thereby, for example, in the case of high-speed traveling or straight traveling, the luminous intensity near the center of the light distribution pattern is increased by moving the movable part of the light shielding member to the insertion position, so that the distance visibility is improved. .

On the other hand, by moving the movable part of the light shielding member along the optical axis direction and shifting from the vicinity of the rear focal position of the projection lens, the cut-off line bright / dark boundary line in the light distribution pattern is blurred, and the concave mirror By reflecting and diffusing the light from the light source and irradiating the slightly diffused light to the lower side of the cutoff line, the light intensity on the lower side of the cutoff line is increased.
Accordingly, for example, in the case of running on an urban area, running on a curved road, and the like, the luminous intensity of the area corresponding to the front of the vehicle in the light distribution pattern is increased by moving the movable part of the light shielding member along the optical axis direction from the insertion position. Therefore, the visibility in front of the vehicle is improved.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to FIGS.
The embodiments described below are preferable specific examples of the present invention, and thus various technically preferable limitations are given. However, the scope of the present invention particularly limits the present invention in the following description. As long as there is no description of the effect, it is not restricted to these aspects.

[Example 1]
FIG. 1 shows the configuration of a first embodiment of a vehicle headlamp according to the present invention.
In FIG. 1, a vehicle headlamp 10 includes a bulb 11 as a light source, a reflection surface 12 that reflects light from the bulb 11 forward, and a projection lens 13 that is disposed in front of the reflection surface 12. The light shielding member 14 disposed between the reflection surface 12 and the projection lens 13, the concave mirror 15 attached to the light source side of the light shielding member 14, and the light shielding member 14 and the concave mirror 15 are integrated with the optical axis. And moving means 16 for moving back and forth along.

  The bulb 11 is a bulb generally used for an automobile headlamp or an auxiliary headlamp. For example, a bulb such as an incandescent bulb, a halogen bulb, a halogen bulb with an infrared reflecting film, or a discharge lamp such as a metal halide lamp is used. In use, the optical axis O is arranged substantially horizontally toward the front, is fixedly held by the socket 11a, and is supplied with power.

  The reflecting surface 12 is formed in a concave shape so as to reflect the light from the bulb 11 forward, and the first focal position F1 is located in the vicinity of the light emitting point of the bulb 11, It is configured as an elliptical reflecting surface so that the second focal position F2 is positioned on the optical axis O extending forward from the bulb 11 on the front side. Here, the elliptical reflecting surface includes not only a spheroid and an elliptic cylinder but also a free-form surface based on an ellipsoid.

  The projection lens 13 is composed of a convex lens, preferably an aspheric lens, and the focal point on the light source side (rear side) on the optical axis O is the second focal position of the reflecting surface 12. It arrange | positions so that it may be located in F2 vicinity.

The light shielding member 14 is for imparting a predetermined light distribution pattern for a low-pass beam to the light irradiated toward the front, and is made of an opaque material.
As shown by the solid line in FIG. 1, the light shielding member 14 is disposed at the focal position on the light source side of the projection lens 13, that is, at the insertion position A near the second focal position F <b> 2 of the reflecting surface 12. .

  Further, the light shielding member 14 can be moved stepwise or continuously by the moving means 16 from the insertion position A indicated by the solid line in FIG. 1 to the movement position B (retraction position) indicated by the dotted line toward the front. It is configured as follows.

The light shielding member 14 has an upper edge 14a that forms a desired light distribution pattern.
More specifically, in the light shielding member 14, the upper edge 14a forms a cut-off line of a low beam for high speed running or straight running at the insertion position A described above. In the light shielding member 14, the upper edge 14a forms a cut-off line of a low beam for running on urban areas and running on curved roads at the movement position B described above.

The concave mirror 15 is disposed on the light source side of the light shielding member 14 described above, and is integrally attached to the light shielding member 14 in this embodiment.
In the case shown in the drawing, the concave mirror 15 is integrally formed on the light source side surface of the light shielding member 14 formed concavely toward the rear, and is moved in the optical axis direction by the moving means 16 together with the light shielding member 14. It has come to be.

  The concave mirror 15 is formed of a part of a substantially spherical shape that is concave toward the rear, and when the light shielding member 14 is at the insertion position A, the center thereof is located near the light emitting portion of the bulb 11. . As the concave mirror 15 moves from the insertion position A to the movement position B, the center thereof is separated from the vicinity of the light emitting portion of the bulb 11.

  The moving means 16 includes, for example, a stepping motor, a DC motor, a solenoid, and the like. For example, the light shielding member 14 is moved stepwise or continuously along the optical axis direction according to the traveling speed or traveling state of the automobile. It comes to control.

The vehicle headlamp 10 according to the embodiment of the present invention is configured as described above, and light is emitted from the light emitting portion of the bulb 11 when the bulb 11 is supplied with power from the socket and emits light.
A part of the light L1 emitted from the bulb 11 is reflected directly or by the reflecting surface 12 and travels forward toward the vicinity of the second focal point F2 of the reflecting surface 12, and is projected by the projection lens 13. It is irradiated toward the front while being focused.
The other part L2 of the light emitted from the bulb 11 is reflected by the concave mirror 15, further reflected by the reflecting surface 12, travels forward, and is irradiated forward through the projection lens 13.

Here, when traveling at a high speed or traveling in a straight line, the light shielding member 14 is located at the insertion position A indicated by a solid line in FIG. 1, and the concave mirror 15 is centered near the light emitting portion of the bulb 11. is doing.
Thereby, a part of the light L1 from the bulb 11 or the reflecting surface 12 is blocked by the light shielding member 14, and the upper edge 14a forms the cut-off line C1 and is irradiated forward. become.
The light L2 reflected by the concave mirror 15 is converged toward the center thereof, then reflected by the reflecting surface 12, and converged toward the second focal position F2. Thereby, it irradiates ahead through the projection lens 13 similarly to the said light L1.

Accordingly, as shown in FIG. 2 (A), the light L1 forms a light distribution pattern having a cut-off line C1 for a low beam slightly below the horizontal line, and the light L2 It will be focused near the center of the pattern.
Here, the luminous intensity distribution in the vertical direction in the light distribution pattern has a relatively large luminous intensity gradient g1 near the cutoff line C1 and a relatively high luminous intensity as shown in FIG. 2B. .
As a result, the light / dark boundary line is sharp in the light distribution pattern, improving the overall luminous intensity and increasing the luminous intensity especially near the center. A simple light distribution pattern can be obtained.

On the other hand, when traveling on an urban area or traveling on a curved road, the light shielding member 14 is moved forward by the moving means 16 to the moving position B indicated by the wavy line in FIG. As a result, the center of the concave mirror 15 is shifted forward from the vicinity of the light emitting portion of the bulb 11.
Thereby, a part of the light L1 from the bulb 11 or the reflecting surface 12 is blocked by the light shielding member 14, and the upper edge 14a forms the cut-off line C2 and is irradiated forward. become. Accordingly, when the light shielding member 14 is shifted forward from the rear focal position of the projection lens 13, the projected image of the upper edge 14a is blurred, so that the light / dark boundary line of the cutoff line C2 is also blurred.
The light L2 reflected by the concave mirror 15 is converged toward the center thereof, then reflected by the reflecting surface 12, slightly diffused, and irradiated forward through the projection lens 13.

Therefore, as shown in FIG. 3A, the light L1 forms a light distribution pattern having a cut-off line C2 for a low beam slightly below the horizontal line, and the light L2 The light is diffused slightly below the cut-off line of the pattern.
Here, the light intensity distribution in the vertical direction in the light distribution pattern has a relatively small light intensity gradient g2 in the vicinity of the cut-off line C2, as shown in FIG.
Thereby, in the light distribution pattern, the light and dark boundary line has a gentle luminous intensity gradient, and a relatively wide area below the cutoff line, i.e., the luminous intensity in front of the vehicle is increased, so that the visibility in front of the vehicle is improved, An optimal light distribution pattern can be obtained for traveling in urban areas and traveling on curved roads.

In this way, when the light shielding member 14 is at the insertion position A, a light distribution pattern similar to that of the conventional passing beam is obtained, and the light L2 reflected by the concave mirror 15 is converged toward the vicinity of the center. Is irradiated. Therefore, the vehicle headlamp 10 is formed with a light distribution pattern with good distance visibility.
When the light shielding member 14 is at the movement position B, the light shielding member 14 is shifted forward from the rear focal position of the projection lens 13 and the center of the concave mirror 15 is shifted forward from the light emitting portion of the bulb 11. . Therefore, in the vehicle headlamp 10, a cut-off line with a gentle luminous intensity gradient is formed as compared with the case where the light shielding member is at the insertion position A. Further, the vehicle headlamp 10 irradiates a wide area below the cut-off line as the reflected light L2 from the concave mirror 15 diffuses. Thereby, the light distribution pattern with favorable visibility in front of the vehicle is formed.
In this way, by moving the light shielding member 14 in the optical axis direction and shifting from the rear focal position of the projection lens 13, the vehicle headlamp 10 not only moves the cut-off line in the vertical direction but also moves the vertical direction thereof. Decrease the luminosity gradient in the direction. In addition, the vehicle headlamp 10 changes the light distribution pattern itself by irradiating the lower region of the cut-off line with the reflected light L2 from the concave mirror 15, so that an optimal light distribution pattern is always obtained.

In the above description, only the case where the light shielding member 14 is located at the insertion position A and the movement position B has been described. However, the present invention is not limited to this, and the light shielding member 14 is stepwise or continuous from the insertion position A to the movement position B. It is also possible to move to.
In this case, as shown in FIG. 4, the light intensity gradient g at the cut-off line light / dark boundary line continuously changes according to the position of the light shielding member 14 in the front-rear direction on the optical axis O. Therefore, when the cut-off line movement is switched, a light distribution pattern suitable for the traveling speed and traveling state of the vehicle is formed, so that the light intensity gradient changes suddenly and gives the driver a sense of incongruity. There is no.

[Example 2]
FIG. 5 shows a configuration of a second embodiment of the vehicle headlamp according to the present invention.
In FIG. 5, the vehicle headlamp 20 has substantially the same configuration as the vehicle headlamp 10 shown in FIG. 1, and therefore the same components are denoted by the same reference numerals and description thereof is omitted.
In the vehicle headlamp 20, the light shielding member 14 is formed perpendicular to the optical axis O, the moving means 16 includes a motor 17 and a transmission mechanism 18, and the moving means 16 is further controlled. The configuration is different in that the drive is controlled by the system 21.

The motor 17 is a motor configured to control the amount of rotation, such as a stepping motor.
In the illustrated case, the transmission mechanism 18 includes a long screw 18a that extends parallel to the optical axis O and is rotationally driven by a motor 17, and a nut member 18b that meshes with the screw 18a. The nut member 18b is moved in the optical axis direction when the 18a is rotationally driven by the motor 17.
The light shielding member 17 and the concave mirror 15 are fixed to the nut member 18b.

  The control system 21 includes a motor driver 22 that drives and controls the motor 17, an ECU 23 as a control unit that controls the motor driver 22, vehicle speed detection means 24, and road information detection means 25.

The motor driver 22 drives and controls the motor 17 by a predetermined angle or a predetermined rotation speed based on a control signal from the ECU 23.
The ECU 23 is composed of, for example, a computer, and calculates the optimum position of the light shielding member 14 on the optical axis O based on detection signals from the vehicle speed detection means 24 and the road information detection means 25. The ECU 23 sends a control signal to the motor driver 22 based on the calculation result.

Specifically, the ECU 23 holds the light shielding member 14 at the insertion position A when the vehicle speed exceeds a predetermined value. However, when the vehicle speed becomes equal to or lower than the predetermined value, the ECU 23 performs light shielding according to the vehicle speed. A control signal is output to the motor driver 22 so as to move the member 14 to an appropriate position up to the movement position B.
Further, the ECU 23 outputs a control signal to the motor driver 22 in accordance with the traveling state of the automobile, for example, traveling on a highway, traveling on a general road, traveling on a straight road, or traveling on a curved road. That is, the ECU 23 holds the light shielding member 14 at the insertion position A during traveling on a highway or traveling on a straight road, but during traveling on a general road or traveling on a curved road, the light shielding member 14 depends on the traveling state. A control signal is output to the motor driver 22 so that the motor 14 is moved stepwise or continuously to an appropriate position between the moving position B and the moving position B.

Here, the vehicle speed detecting means 24 can use the output of the vehicle speed sensor mounted on the automobile as it is.
The road information detecting means 25 can use road information in a car navigation device, for example.

  According to the vehicle headlamp 20 having such a configuration, the light-shielding member 14 is operated according to the traveling state such as the vehicle speed and road conditions of the automobile by operating in the same manner as the vehicle headlamp 10 shown in FIG. By moving in the optical axis direction and shifting from the rear focal position of the projection lens 13, not only the cut-off line is moved in the vertical direction but also the light intensity gradient in the vertical direction is made gentle. In addition, the vehicle headlamp 20 changes the light distribution pattern itself by irradiating the lower region of the cut-off line with the reflected light L2 from the concave mirror 15, so that an optimal light distribution pattern can always be obtained. Become.

[Example 3]
FIG. 6 shows a configuration of a third embodiment of the vehicle headlamp according to the present invention.
In FIG. 6, the vehicle headlamp 30 has substantially the same configuration as the vehicle headlamp 20 shown in FIG. 5, and thus the same components are denoted by the same reference numerals and description thereof is omitted.
The vehicle headlamp 30 includes a fixed portion 14b in which the light shielding member 14 is fixedly disposed at the insertion position A, and two movable portions 14c and 14d that are movable with respect to the optical axis O before and after the fixed portion 14b. And is different in that a concave mirror 15 is attached to the rear movable portion 14d.
The fixed portion 18b has an upper edge having a thickness in the direction of the optical axis O, and preferably has an upper end surface formed as a reflection surface.

In this case, the transmission mechanism 18 of the moving means 16 is provided with screw threads 18a1 and 18a2 in opposite directions before and after the position corresponding to the insertion position A, and with respect to the screw threads 18a1 and 18a2. The nut members 18b1 and 18b2 for holding the movable members 14c and 14d are screwed together.
Thereby, when the screw 18a is rotationally driven by the motor 17, the nut members 18b1 and 18b2 move in opposite directions.

  According to the vehicle headlamp 30 having such a configuration, the light-shielding member 14 is operated according to the traveling state such as the vehicle speed and road conditions of the automobile by operating in the same manner as the vehicle headlamp 10 shown in FIG. The projection lens 13 is shifted from the rear focal position by moving in the optical axis direction. Thereby, the vehicle headlamp 30 not only moves the cutoff line in the vertical direction, but also makes the luminous intensity gradient in the vertical direction gentle and irradiates the reflected light L2 from the concave mirror 15 to the lower area of the cutoff line. As a result, the optimal light distribution pattern can always be obtained by changing the light distribution pattern itself.

In this case, when the movable parts 14c and 14d are separated from each other with respect to the optical axis O, the chromatic aberration due to the projection lens 13 can be corrected because the movable parts 14c and 14d have a thickness in the direction of the optical axis O. Therefore, coloring due to chromatic aberration of light irradiated toward the front can be eliminated.
In this case, the movable portion 14d behind the light shielding member 14 is moved backward from the insertion position A. At this time, the movable portion 14d is displaced from the rear focal position of the projection lens 13 in the same manner as when moved forward, and the cutoff line is blurred and the reflected light from the concave mirror 15 is diffused below the cutoff line. Will be irradiated.

  Furthermore, the upper end surface of the fixed portion 14b of the light shielding member 14 has a width in the direction of the optical axis O. For this reason, a part L3 of the light reflected on the upper side of the reflecting surface 12 is incident on the upper end surface of the fixed portion 14b and reflected. Then, the light L3 is irradiated through the projection lens 13 slightly upward from the horizontal line. As a result, a so-called overhead sign region for satisfying the minimum illuminance from the horizontal to 4 degrees above the light distribution pattern is defined. Therefore, for example, a sign or the like disposed on the upper front side of the vehicle can be easily visually recognized.

  In the embodiment described above, the vehicle headlamps 10, 20, and 30 are each configured as a headlamp of an automobile, but are not limited thereto, and include an auxiliary lamp such as an auxiliary headlamp and a fog lamp of the automobile. It is clear that the present invention can be applied to a vehicle headlamp in a broad sense.

  In the above-described embodiment, the moving mechanism 16 in the vehicle headlamps 20 and 30 is configured by the motor 17 and the transmission mechanism 18, but the present invention is not limited thereto, and a moving mechanism having an arbitrary configuration can be used. The light shielding member 14 can be moved directly in the optical axis direction using, for example, a linear motor.

  Further, in the above-described embodiment, the movable light shielding member 14 in the vehicle headlamps 10 and 20 and the movable members 14c and 14d in the vehicle headlamp 30 are provided on the left and right sides in the lateral direction. In order to restrict the light distribution in the region near the horizontal line at the insertion position and eliminate the dazzling light to the oncoming vehicle, the light shielding member 14 and the movable members 14c, 14d can only use the light distribution pattern to the oncoming lane. You may make it define.

  In the above-described embodiment, the control system 21 includes the road information detection unit 25 in the vehicle headlamps 20 and 30. However, the present invention is not limited to this, and the road information detection unit 25 may be omitted.

  In this way, according to the present invention, with a simple configuration, the light distribution distribution below the cutoff line is changed to improve the distance visibility when traveling at high speeds, and before the vehicle when traveling in urban areas. An extremely excellent vehicle headlamp that improves visibility can be provided.

It is a schematic sectional drawing which shows the structure of 1st embodiment of the vehicle headlamp by this invention. It is a graph which shows the luminous intensity gradient of (A) light distribution pattern and (B) cut-off line when the light shielding member in the vehicle headlamp of FIG. 1 exists in the insertion position A. It is a graph which shows the luminous intensity gradient of (A) light distribution pattern and (B) cutoff line when the light-shielding member in the vehicle headlamp of FIG. It is a graph which shows the relationship between the movement position of the light-shielding member in the vehicle headlamp of FIG. 1, and the luminous intensity gradient of a cutoff line. It is a schematic sectional drawing which shows the structure of 2nd embodiment of the vehicle headlamp by this invention. It is a schematic sectional drawing which shows the structure of 3rd embodiment of the vehicle headlamp by this invention. It is a schematic sectional drawing which shows the structure of an example of the conventional vehicle headlamp. It is a graph which shows the light distribution pattern by the vehicle headlamp of FIG. It is a schematic sectional drawing which shows the structure of the other example of the conventional vehicle headlamp. It is a graph which shows the light distribution pattern by the vehicle headlamp of FIG. It is a schematic sectional drawing which shows the structure of the further another example of the conventional vehicle headlamp.

Explanation of symbols

10, 20, 30 Vehicle headlamp 11 Bulb (light source)
DESCRIPTION OF SYMBOLS 12 Reflecting surface 13 Projection lens 14 Light-shielding member 14a Upper edge 14b Fixed member 14c, 14d Movable member 15 Concave mirror 16 Moving means 17 Motor 18 Transmission mechanism 21 Control system 22 Motor driver 23 ECU
24 vehicle speed detection means 25 road information detection means

Claims (7)

A light source;
A concave elliptical reflecting surface disposed such that the first focal position is located near the light source and the second focal position is located on the optical axis of the light source extending substantially horizontally from the light source;
A convex projection lens in which the focal position on the light source side is arranged near the second focal position of the reflecting surface;
The upper edge is formed so as to block the reflected light from the light source to the projection lens to define a cut-off line, and is separated from the insertion position near the second focal position of the reflecting surface and the second focal position. A light shielding member that moves between the retracted position,
A concave mirror provided on the reflection direction side of the reflection surface, movable between the insertion position and the retraction position, and reflecting light from the light source to the reflection surface;
A vehicle headlamp comprising a driving device for inserting and removing the light shielding member and the concave mirror at an insertion position;
The center of the concave mirror
A vehicle headlamp in the vicinity of the light source when the light shielding member is in the insertion position. A light source;
Arranged so that the first focal position is located near the light source and the second focal position is located on the optical axis of the light source extending substantially horizontally forward so that the light from the light source is reflected forward A concave ellipsoidal reflective surface toward the front,
A convex projection lens arranged in front of the reflecting surface, on the optical axis of the light source, so that the focal position on the light source side is located near the second focal position of the reflecting surface;
A light-shielding member that is disposed near the second focal position of the reflecting surface, and whose upper edge defines a cut-off line;
In a vehicle headlamp comprising:
The light shielding member includes a movable part that is movable in the optical axis direction by the moving means, and
Furthermore, a concave concave mirror toward the rear is integrally attached to the light source side of the movable part of the light shielding member,
The concave mirror is formed such that when the movable part of the light shielding member is positioned near the second focal position (insertion position) of the reflecting surface, the center thereof is positioned near the light source,
When the movable part of the light shielding member is at the insertion position, a light distribution pattern having a high luminous intensity near the center is formed,
The vehicle headlamp is characterized in that a slightly diffused light distribution pattern is formed when the movable part of the light shielding member moves along the optical axis from the insertion position.   2. The vehicle headlamp according to claim 1, wherein the moving means moves the movable part of the light shielding member stepwise or continuously in the optical axis direction in accordance with the traveling speed of the automobile.   The vehicle according to claim 1, wherein the light shielding member further includes a fixed portion fixed at an insertion position, and the movable portion is movable toward the light source side of the fixed portion. Headlight. The light shielding member further includes a second movable part on the projection lens side of the fixed part,
4. The vehicle headlamp according to claim 3, wherein the second movable part is movable in the direction opposite to the movable part in conjunction with the movable part by the moving means.   The moving means moves the movable part and / or the second movable part of the light shielding member and the concave mirror in the direction of the optical axis in accordance with the running state of the automobile. The vehicle headlamp described in Crab.   The vehicle according to any one of claims 1 to 5, wherein the movable part and / or the second movable part of the light shielding member blocks light directed to at least the opposite lane side of the automobile in the light distribution pattern. Headlight.

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