JP4960747B2 - Vehicle headlamp - Google Patents

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 known from Patent Document 1, for example, and is configured as shown in FIG.
That is, in FIG. 5, 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 bulb 2 is a bulb that is generally used for automobile headlamps or auxiliary headlamps. For example, a bulb or a discharge bulb is used.
The optical axis O of the bulb 2 is arranged almost horizontally toward the front, is fixedly held by a socket, and is supplied with power.
Here, the bulb 2 is arranged such that the light emitting portion 2a extends along the optical axis O.

The reflection surface 3 is composed of an elliptical reflection surface arranged so that the first focal point F1 is positioned in the vicinity of the light emitting portion 2a of the bulb 2 and the long axis extends substantially horizontally toward the front. The inner surface is formed as a reflecting surface.
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 its focal point on the light source side (rear side) is disposed in the vicinity of the second focal position F2 of the reflective surface 3, and forward from the bulb 2 or the reflective surface 3. The light traveling toward is condensed and irradiated toward the front.

  The light-shielding member 5 is for giving a predetermined light distribution pattern for a low-pass beam to the light irradiated toward the front, and is disposed in the vicinity of the second focal position F2 of the reflective surface 3. ing. Moreover, in order to form a cut-off line in the light distribution pattern, the upper edge 5a is formed in a predetermined shape.

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. The light travels forward toward the vicinity of the second focal point, and 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 blocking member 5. Further, a cut-off line is formed by the upper edge 5a of the light shielding member 5, and the light is irradiated forward as a passing beam.

  Thereby, the cut-off line is projected by the projection lens 5 as shown in FIG. For this reason, with respect to the light distribution pattern, a cut-off line C is formed which extends horizontally from the center to the right slightly below the horizontal line and horizontally from the center to the left side substantially along the horizontal line. On the other hand, light suitable for the low beam is emitted.

Thus, in such a vehicle headlamp 1, the cut-off line C is formed by the light shielding member 5 in the case of a passing beam. Thereby, as shown in FIG. 6, a light distribution pattern A1 for the passing beam is formed.
By irradiating the upper edge 5a of the light shielding member 5 forward in the light irradiation direction, no light is irradiated on the upper side of the cutoff line C. For this reason, it does not give dazzling light to the oncoming vehicle.

By the way, in recent standards for vehicle headlamps, as shown in FIG. 6, in order to confirm road signs and the like installed on the road, the upper side of the light distribution pattern A1 for the passing beam as the main light distribution unit is shown. Thus, a so-called overhead sign light distribution pattern A2 has been adopted near the center.
The range and illuminance of the light distribution pattern A2 for overhead sign are determined by the light distribution standard.
Light distribution standards including such overhead sign light distribution were previously recommended standards, but are now mandatory in new standards, and vehicle headlamps that do not meet such light distribution standards can be used as non-standard. It will disappear.

  In the vehicle headlamp 1 described above, in order to cope with such light distribution for overhead sign, the light distribution for overhead sign is placed on the light shielding member 5 at a position deviated from the focal position (F2) of the projection lens 4. A window portion 5b is provided.

Thereby, a part of the light emitted from the bulb 2 is reflected by the lower region 3 a of the reflection surface 3 and passes through the window portion 5 b of the light shielding member 5. Thereby, it irradiates through the projection lens 4 toward the upper side of a front horizontal line, and forms light distribution for overhead signs.
In this case, since the window portion 5b is out of the focus of the projection lens 4, the overhead sign light distribution is projected in a slightly blurred state. As a result, there is no concern about the bright and dark borders around this light distribution.
Further, the light reflected by the lower region 3a of the reflecting surface 3 that does not form the low beam light distribution pattern is used. For this reason, the light distribution pattern for the passing beam does not become dark.

  On the other hand, in Patent Document 2, a reflecting surface is provided on the mutually facing surfaces of the movable shades of the two thin plate structures arranged near the front focal position of the reflector, and a part of the reflected light from the reflector is provided. Is guided to the gap between these movable shades, the light reflected by the reflecting surface in this gap is incident on the lower part of the condenser lens, and the upper overhead sign region is irradiated by the condenser lens. A headlamp is disclosed.

Further, in Patent Document 3, an auxiliary reflector that reflects light from a light source forward without passing through a condensing lens is provided above and below the reflector, so that the vertical rectangular outline shape of the auxiliary reflector is illuminated. A headlamp is disclosed.
Japanese Utility Model 05-05807 JP 2004-172104 A JP 2001-095910 A

However, in the vehicle headlamp 1 according to Patent Document 1, a window portion 5 b for forming an overhead sign light distribution is formed below the upper edge 5 a of the light shielding member 5. For this reason, a certain dimension is required between the window portion 5b and the upper edge 5a in view of the structure.
Accordingly, it has been impossible to set the sign light distribution pattern so as to be in contact with the upper end of the low beam light distribution pattern.

Further, the light reflected by the reflecting surface 3 for forming the light distribution for the passing beam is allowed to pass through the window portion 5b, and the shape of the window portion 5b is projected onto the overhead sign region by the projection lens 4. Yes.
Therefore, the overhead sign light distribution is formed by the light condensed by the projection lens 4. For this reason, the light distribution characteristic that is optimal as the light distribution for overhead sign is not always achieved.

  On the other hand, the structure of the headlamp according to Patent Document 2 is complicated because it includes two movable shades. Also in this case, it is impossible to make the cutoff line and the overhead sign light distribution close to each other. Further, since the overhead sign light distribution passes through the projection lens, it has been difficult to obtain optimum light distribution characteristics.

  Moreover, in the vehicle headlamp according to Patent Document 3, the reflected light from the auxiliary reflector is guided to the outside without passing through the projection lens. However, the reflected light from the auxiliary reflector does not form an overhead sign light distribution. For this reason, the object and effect differ from the present invention.

  In view of the above, an object of the present invention is to provide a vehicle headlamp in which an overhead sign light distribution having an optimal light distribution characteristic can be formed with a simple configuration.

According to the present invention, the first object is located near the light source and the second focal position is light so that the light from the light source and the light from the light source are reflected forward in the light irradiation direction. On the optical axis of the light source, in front of the reflection surface, a concave elliptical reflection surface that is concave toward the front of the light irradiation direction, which is arranged so as to be positioned on the optical axis of the light source extending substantially horizontally in front of the irradiation direction A convex projection lens arranged so that the focal position on the light source side is located near the second focal position of the reflecting surface, and an upper edge arranged near the second focal position of the reflecting surface. The vehicle headlamp includes: a light shielding member formed so as to define a cut-off line; and a cover that supports the projection lens and surrounds a region between the projection lens and the reflecting surface. reflecting surface, near the periphery of the plane, the projecting light from a light source Has a cutting portion for forming an auxiliary reflecting surface for overhead sign light distribution reflected from the outside toward the light irradiation direction in front of the lens, the cover, the reflective surface with an opening toward the front This is achieved by a vehicle headlamp characterized by including a hole through which light reflected by the cut portion can be transmitted.

  In the vehicle headlamp according to the present invention, preferably, the cut portion is provided in a region below the optical axis of the reflection surface.

  In the vehicle headlamp according to the present invention, preferably, the cut portion focuses the light from the light source and reflects the light so that a minimum beam diameter is obtained near the center of the hole of the cover.

  In the vehicle headlamp according to the present invention, preferably, the cut portion has a focus value of about F8 to F12.

  In the vehicle headlamp according to the present invention, preferably, the cut portion forms a light distribution pattern for an overhead sign that is long in the lateral direction in the vicinity of 4 degrees above the horizontal line.

According to the above configuration, the light incident on the reflecting surface from the light source is reflected by the reflecting surface, converged toward the second focal position, and further converged by the projection lens and directed forward in the light irradiation direction. Is irradiated.
At this time, the light is cut off by the light shielding member. As a result, a light distribution pattern for the passing beam is formed.

Further, the light incident on the cut portion provided on the periphery of the reflection surface from the light source is reflected by the cut portion and converged. This light passes through the hole in the cover without passing through the projection lens, and then diffuses slightly and is irradiated to the light distribution area for overhead sign slightly above the horizontal line in front of the light irradiation direction.
As a result, a light distribution for overhead sign is formed, and for example, it is irradiated to a road sign or the like located slightly above the horizon with respect to the traveling direction of the automobile. Thereby, these road signs etc. are illuminated brightly, and these road signs etc. can be visually recognized reliably.

  At that time, the cut portion that forms the overhead sign light distribution is reflected by the periphery of the reflecting surface at the time of the passing beam and does not enter the projection lens, and the light that does not form the passing beam distribution pattern enters. For this reason, the light flux that forms the light distribution pattern for the passing beam does not decrease.

  Further, the overhead sign light distribution is irradiated toward the overhead sign light distribution region without passing through the projection lens. For this reason, a light distribution characteristic different from that of the low beam is given, and an optimum light distribution for overhead sign is obtained close to the upper edge of the light distribution pattern of the low beam, and overhead sign visibility is improved. improves.

The overhead sign light distribution is formed by the cut portion of the reflecting surface and the hole of the cover. For this reason, compared with the conventional vehicle headlamp, no additional parts are required, so that it can be configured at a low cost with a simple configuration.
Furthermore, even if a part of the light reflected by the reflecting surface and forming the light distribution pattern of the passing beam passes through the hole of the cover, it does not enter the projection lens. For this reason, such light does not become illusion light.

  In the case where the cut portion is provided in a region below the optical axis of the reflection surface, light that is blocked by the light shielding member at the time of the passing beam and does not form the passing beam light distribution pattern is incident. For this reason, the light flux that forms the light distribution pattern for the passing beam does not decrease.

  When the cut portion focuses the light from the light source and reflects the light so that it has a minimum beam diameter near the center of the hole in the cover, the hole provided in the cover only needs to have the minimum diameter. .

  When the cut portion has a focus value of about F8 to F12, the reflected light from the cut portion is appropriately diffused after passing through the hole in the cover, and the optimum overhead sign distribution is obtained. Light will be formed.

  When the cut part forms a light distribution pattern for overhead signs that is long in the horizontal direction at around 4 degrees above the horizontal line, road signs and the like installed in a wide range on the left and right above the road can be reliably recognized. It will be.

  In this way, according to the present invention, it is possible to provide a vehicle headlamp in which an overhead sign light distribution having an optimal light distribution characteristic can be formed with a simple configuration.

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.

FIG. 1 shows the configuration of an embodiment of a vehicle headlamp according to the present invention.
In FIG. 1, a vehicle headlamp 10 is configured as an automobile headlamp, and includes a bulb 11 as a light source, a reflecting surface 12 that reflects light from the bulb 11 forward in the light irradiation direction, and a bulb. 11 or the projection lens 13 for converging the light traveling forward from the reflecting surface 12, the light shielding member 14 disposed in the optical path from the bulb 11 to the projection lens 13, and holding the projection lens 13 and the projection lens 13. And a cover 15 surrounding a region between the reflecting surface 12 and the reflecting surface 12.

The bulb 11 is a bulb generally used for an automobile headlamp or an auxiliary headlamp. For example, an incandescent bulb, a halogen bulb, or a discharge lamp such as a high intensity discharge (HID) is used. The optical axis O is arranged almost horizontally toward the front, is fixedly held by a socket, and is supplied with power.
Here, the bulb 11 is arranged such that the light emitting portion 11 a extends along the optical axis O.

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 portion 11a of the bulb 11. It is configured as follows. Moreover, it is comprised as an elliptical reflective surface arrange | positioned so that a long axis may correspond with the optical axis O extended toward the light irradiation direction front from the bulb | ball 11. FIG.
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 reflection surface 12 is formed so as to give a light distribution pattern for passing beams almost entirely except for a region of a cut portion 12a described later.

  The projection lens 13 is composed of, for example, an aspherical convex lens, and is disposed on the optical axis O of the bulb 11 so that the focal position on the light source side is located near the second focal position F2 of the reflecting surface 12. ing.

The light shielding member 14 is made of a light shielding material, and is disposed near the second focal position F2 of the reflecting surface 12, that is, near the focal position on the light source side of the projection lens 13.
Thereby, the upper edge 14a of the light shielding member 14 is projected forward by the projection lens 13 in the light irradiation direction. Thereby, a cut-off line in the light distribution pattern for the passing beam is formed.

  The cover 15 holds the projection lens 13 in a predetermined position. Moreover, it is connected to the periphery of the reflecting surface 12 so as to surround the region between the projection lens 13 and the reflecting surface 12. As a result, the optical path from the reflecting surface 12 to the projection lens 13 is protected from dust and the like.

The above configuration is substantially the same as the conventional vehicle headlamp 1 shown in FIG. 5, but the vehicle headlamp 10 according to the embodiment of the present invention is configured differently in the following points.
That is, the reflection surface 12 has an overhead sign in the peripheral region on the right side in the light irradiation direction as shown in FIG. 2, and preferably in the region below the optical axis O as shown in FIG. The cut part 12a which forms the auxiliary | assistant reflective surface for the light distribution for light is provided.

  The cover 15 includes a hole 15a through which light emitted from the bulb 11 and reflected by the cut portion 12a for overhead sign light distribution is passed.

Here, the cut portion 12a is formed integrally with the reflective surface 12 as an auxiliary reflective surface based on a focus value of about F8 to F12, for example, with a different curvature from other portions of the reflective surface 12. .
The cut portion 12a focuses the reflected light on the light distribution area for overhead sign, that is, slightly upward (for example, upward by 4 degrees) and wide in the left-right direction (for example, in an angle range of 10 to 20 degrees). It has become.
At that time, the cut portion 12a is configured to diffuse the reflected light toward the front in the light irradiation direction after setting the reflected light to the minimum beam diameter near the center of the hole 15a of the cover 15.

  Further, the size and shape of the cut portion 12a are selected so that the reflected light forms a light distribution for overhead sign having a predetermined size and shape.

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 11a of the bulb 11 when the bulb 11 is supplied with power from outside and emits light.
A part L1 of the light emitted from the bulb 11 is reflected by the reflecting surface 12, converged toward the vicinity of the second focal position F2, and further converged via the projection lens 13 while being forward in the light irradiation direction. Irradiated towards.
At this time, a cut-off is formed by the upper edge 14a of the light shielding member 14, whereby a light distribution pattern B1 for a low beam is formed as shown in FIG.

  Further, the light L2 emitted from the bulb 11 toward the lower right side is incident on the cut portion 12a provided in the peripheral region on the lower right side of the reflecting surface 12, and is reflected by the cut portion 12a. While focusing, the light travels forward in the light irradiation direction substantially parallel to the optical axis O, passes through the hole 15a of the cover 15 and then diffuses slightly, for an overhead sign slightly above the horizontal line in front of the light irradiation direction. The light distribution area is irradiated to form an overhead sign light distribution pattern B2 as shown in FIG.

Thereby, the light distribution for overhead signs is irradiated to the road sign etc. which are located a little above the horizon with respect to the traveling direction of the automobile, for example. Thereby, these road signs etc. are illuminated brightly, and these road signs etc. can be visually recognized reliably.
In this case, the cut portion 12a for light distribution for overhead sign on the reflection surface 12 reflects a light beam that does not contribute to the formation of the light distribution pattern for the passing beam. Thereby, the light beam forming the light distribution pattern B1 of the low beam is not reduced by the installation of the cut portion 12a.

Further, the outline of the cut portion 12a determines the shape of the periphery of the overhead sign light distribution pattern B2. Therefore, by appropriately selecting the size and shape of the cut portion 12a, the size and shape of the overhead sign light distribution pattern B2 can be adjusted without depending on the optical characteristics of the projection lens. .
Therefore, the overhead sign light distribution can be formed to satisfy a predetermined light distribution standard.

Furthermore, the reflected light from the cut portion 12a diffuses slightly after passing through the hole 15a of the cover 15. As a result, the outline of the peripheral edge of the overhead sign light distribution pattern is blurred.
Accordingly, the luminance change at the periphery of the light distribution pattern for overhead sign becomes smooth, and the boundary between the bright part and the dark part is not particularly difficult to see.

  Even if the light reflected by the reflecting surface 12 or the direct light from the bulb 11 directly enters the hole 15 a of the cover 15, it does not enter the projection lens 13. For this reason, it does not emit to the outside and become dazzling light.

  Thus, according to the embodiment of the present invention, a part of the reflection surface 12 is integrally formed as the cut portion 12a. Moreover, by providing the hole 15a in the cover 15, the overhead light distribution pattern B2 can be formed without the need for additional components.

  In the above-described embodiment, for overhead sign light distribution, the cut portion 12a is provided in the lower right region of the reflective surface 12, and the cover 15 is provided with a hole 15a correspondingly, Not limited to this, a region of the reflecting surface 12 where the reflected light does not enter the projection lens 13 or does not form a passing beam even when entering the projection lens 13, for example, the upper right side, the left side of the reflecting surface 12, Cut portions 12a are provided above, below, or in an oblique region from the optical axis O between them, and cut portions 12a are provided at a plurality of locations among these, and holes 15a are formed in the cover 15 correspondingly. It is clear that may be provided.

  Furthermore, in the above-described embodiment, the case where the vehicle headlamp 10 is a headlamp has been described. However, the present invention is not limited to this, and other types of vehicle headlamps, for example, auxiliary headlamps such as fog lamps are configured. It is also possible.

  As described above, according to the present invention, it is possible to provide an extremely excellent vehicle headlamp that can form an overhead sign light distribution having an optimal light distribution characteristic with a simple configuration.

It is a schematic side view which shows the structure of one Embodiment of the vehicle headlamp by this invention. It is the schematic perspective view which abbreviate | omitted the cover in the vehicle headlamp of FIG. It is a schematic perspective view which shows the hole of the cover in the vehicle headlamp of FIG. It is a graph which shows the light distribution pattern for the passing beam and overhead sign by the vehicle headlamp of FIG. It is a schematic side view which shows the structure of an example of the conventional vehicle headlamp. It is a graph which shows the light distribution pattern for the passing beam and overhead sign by the vehicle headlamp of FIG.

Explanation of symbols

10 Vehicle headlights 11 Bulb (light source)
12 reflective surface 12a cut part 13 projection lens 14 light shielding member 15 cover 15a hole

Claims (5)

A light source;
On the optical axis of the light source, the first focal position is located near the light source and the second focal position extends substantially horizontally forward in the light irradiation direction so that light from the light source is reflected forward in the light irradiation direction. A concave elliptical reflecting surface facing forward in the direction of light irradiation arranged to be located at
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;
A cover that supports the projection lens and surrounds a region between the projection lens and the reflecting surface;
In vehicle headlamps, including
The reflective surface has a cut portion forming an auxiliary reflective surface for light distribution for overhead sign that reflects light from the light source from the outside of the projection lens toward the front in the light irradiation direction in the vicinity of the peripheral edge in the surface. Have
The cover includes a hole that opens toward the front and allows the light reflected by the cut portion of the reflecting surface to pass through.
A vehicle headlamp characterized by that.   The vehicle headlamp according to claim 1, wherein the cut portion is provided in a region below the optical axis of the reflection surface.   3. The vehicle headlamp according to claim 1, wherein the cut portion focuses light from a light source and reflects the light so as to have a minimum beam diameter near a center of the hole of the cover. .   The vehicle headlamp according to any one of claims 1 to 3, wherein the cut portion has a focus value of about F8 to F12.   5. The vehicle headlamp according to claim 1, wherein the cut portion forms a light distribution pattern for an overhead sign that is long in the horizontal direction at a vicinity of 4 degrees above the horizontal line.

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