JP4608645B2 - Vehicle lighting - Google Patents

Description

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

Conventionally, a so-called projector-type vehicle headlamp for an automobile is configured as shown in FIG. 7, for example.
That is, in FIG. 7, the headlamp 1 is configured as a monocular vehicle headlamp, and the bulb 2 as a light source and the light emission center of the bulb 2 are located near the first focal position F1 and are long. An elliptical reflecting surface 3 that is arranged so that its axis coincides with the optical axis of the bulb 2 and reflects the light from the bulb 2 forward, and the focal position on the light source side of the reflecting surface 3 A projection lens 4 that is arranged near the second focal position F2 and focuses light from the bulb 2 or the reflection surface 3; and a second of the reflection surface 3 in the optical path from the bulb 2 to the projection lens 4. And a light shielding shutter 5 for forming a cut-off disposed near the focal position F2.

Here, the bulb 2 is called a so-called C-8 light source, and is disposed forward so that the central axis thereof coincides with the optical axis of the projection lens extending substantially horizontally toward the front.
The C-8 light source has a relatively weak emission intensity distribution on the front and rear end sides in the longitudinal direction, and relatively strong in the vertical and horizontal directions.
Therefore, the bulb 2 is attached from the rear side of the reflecting surface 3, and the light emitted in the vertical direction is reflected forward by the reflecting surface 3 to increase the light intensity of the irradiation light.

According to the vehicle headlamp 1 having such a configuration, after the light emitted from the bulb 2 is reflected directly or by the reflection surface 3 and converges toward the second focal position of the reflection surface 3. Then, the light enters the projection lens 4 and is focused by the projection lens 4 to be irradiated forward.
At this time, a part of the light incident on the projection lens 4 is blocked by the light-shielding shutter 5, so that a desired light distribution characteristic that shortens the irradiation distance on the oncoming lane side so as not to give a dazzling light to the oncoming vehicle. Thus, a so-called passing beam is formed.
In the case of a vehicle headlamp for a traveling beam, the above-described light-shielding shutter 5 is omitted, and the light from the bulb 2 is reflected and focused by the reflecting surface 3, and further forward by the projection lens 4. By being irradiated, a traveling beam is formed.

However, in the headlamp having such a configuration, as described above, since the bulb is disposed forward as the C-8 light source, the overall length L in the front-rear direction of the entire lamp becomes relatively long, The mounting space for the automobile body becomes large, and the degree of freedom of attachment is small, which becomes a restriction on the body design of the automobile.
In particular, when a HID (High Intensity Discharge) light source is used as the bulb 2, a relatively large power supply socket 2a in which a part of a lighting device for emitting the HID light source is incorporated is necessary. Since the depth of the HID light source itself in the optical axis direction is about 100 mm, the total length L of the headlamp 1 is about 180 mm.

By the way, in recent automobiles, the overhang of the front part of the vehicle body is short, and the shape of the vehicle body is rounded down and rounded to improve aerodynamic performance, and wide tires with large flatness and large-diameter wheels tend to be adopted. There is.
For this reason, the space before and behind for installing a headlamp in the inside of the vehicle body front part of a motor vehicle has become very small. Therefore, there is a strong demand for shortening the depth of the vehicle headlamp in the optical axis direction.

  On the other hand, from the viewpoint of safety and the like, in order to increase the light intensity, the use of HID light sources is increasing, and the use of variable light distribution headlamps {so-called AFS (Active Front Lighting System)} for curved roads Therefore, projector-type vehicle headlamps are often used because of the demand for downsizing the light emitting surface.

On the other hand, Patent Literature 1 and Patent Literature 2 disclose a vehicle headlamp in which a bulb is set sideways to be a C-6 light source and further disposed below the optical axis of the projection lens. Yes.
According to such a structure, the full length of a lamp can be shortened by arrange | positioning a bulb | bulb horizontally.

  In such a projector-type vehicle headlamp, the optical axis side region of the reflecting surface reflects the light from the bulb and guides it to the projection lens, thereby forming a diffusion region in the light distribution pattern. However, since the bulb is arranged below the optical axis, it is not necessary to provide a notch in the region on the side of the optical axis of the reflection surface described above in order to insert the bulb into the lamp from the side. For this reason, the amount of light in the diffusion region in the light distribution pattern does not decrease, and a diffusion region with a sufficient amount of light can be formed.

Further, in Patent Document 3, a dedicated reflection surface for variable light distribution, a projection lens, and a movable reflection surface are added, and the movable reflection surface is opened and closed to change the light distribution, thereby rapidly changing the light distribution shape. A variable light distribution type vehicle headlamp that avoids such a change is disclosed.
JP 2004-127830 A JP 2005-1000076 JP-A-2005-166282

By the way, in the projector-type vehicle headlamp described above, the light emission center of the bulb is arranged so as to be located immediately below the optical axis, and the light is emitted from the bulb in the direction of the central axis to be side of the reflection surface of the optical axis. The light reflected by the region passes through the projection lens and is then emitted to a side region in the light distribution pattern, a so-called diffusion region.
For this reason, since the light emitted along the optical axis of the bulb is not irradiated near the front center, the light use efficiency from the bulb is lowered, and the maximum luminous intensity near the center in the light distribution pattern is lowered. .

Further, among the light irradiated forward from the bulb, the light that does not enter the projection lens is not irradiated forward and does not contribute to the formation of the light distribution pattern, so that the total luminous flux is insufficient. End up.
Further, in the case of the HID light source, the horizontal direction shortens the optical axis direction only to about 50 mm, and it has not been possible to realize a significant depth reduction.

  Furthermore, in the vehicle headlamp according to Patent Document 3, since the light source is similarly disposed along the optical axis, the depth becomes long.

  In view of the above, it is an object of the present invention to provide a bulb-type projector-type vehicle headlamp with a simple configuration that reduces the overall depth of a lamp without reducing brightness. It is aimed.

According to the configuration of the present invention, the above object is achieved by a light source that is disposed horizontally on a lamp optical axis that extends horizontally in the longitudinal direction of the vehicle and whose light emission center is positioned on the lamp optical axis, and in front of the light source. a first projection lens above or below the lamp optical axis is oriented towards the lamp optical axis direction, in front of the light source, the tip side of the light source disposed toward the lamp optical axis direction The second projection lens and the first focal position are arranged near the light emitting point of the light source, and the second focal position is arranged near the focal position on the rear side of the first projection lens. In the front of the light source, an ellipsoidal first reflecting surface that reflects the light emitted from the light source to the upper side or the lower side behind and reflects the light toward the focal position on the rear side of the first projection lens, with the first focal position is disposed near the light emitting point of the light source, the light source And the tip-side region is reflected a second reflecting surface disposed on the distal region Ru is focused on the second focal position of the light source of the light source light at the side to be emitted towards the tip of the light source A third mirror that is arranged to intersect the optical axis of the light source in the side region and focuses reflected light from the second reflecting surface toward a focal position on the rear side of the second projection lens; The second reflecting surface, the first focal position of which is arranged near the light emitting point of the light source, and the second focal position of the second projection lens This is achieved by a vehicle headlamp characterized in that the rear focal position is arranged in the vicinity of a conjugate position by the third reflecting surface.

The vehicle headlamp according to the present invention preferably further includes a third projection lens disposed in front of the light source, below or above the light axis of the lamp, and a first focal position near the light emitting point of the light source. And the second focal position is arranged near the focal position on the rear side of the third projection lens, and the light emitted from the light source to the lower side or the upper side is reflected to reflect the first focal position. And an elliptical fourth reflecting surface for focusing toward the rear focal position of the three projection lenses.

  The vehicle headlamp according to the present invention is preferably arranged in the vicinity of the rear focal position with respect to at least one of the first, second or third projection lenses, and has a predetermined light distribution pattern. A light-shielding shutter that forms a cut-off line that defines

In the vehicle headlamp according to the present invention, preferably, the light shielding shutter is formed in a plane perpendicular to the lamp optical axis, or in an arc shape or an ellipsoid curved from the optical axis toward the front side.

  In the vehicle headlamp according to the present invention, preferably, at least one light-shielding shutter has a slit hole at a position corresponding to the overhead sign, and the slit hole is in front of the focal position on the rear side of the corresponding projection lens. It is shifted and arranged.

  In the vehicle headlamp according to the present invention, preferably, at least one of the first, second and third projection lenses is configured as a Fresnel lens.

According to the above configuration, the light that is horizontally disposed on the lamp optical axis that extends horizontally in the vehicle front-rear direction and the light emitted from the light source having the light emission center located on the lamp optical axis to the upper or lower side is The light is reflected by the first reflecting surface, converged toward the second focal position, that is, the focal position on the rear side of the first projection lens, and further irradiated forward through the first projection lens.
Further, the light emitted from the light source to the front side and incident on the second reflecting surface is reflected by the second reflecting surface, travels toward the third reflecting surface, and is reflected by the third reflecting surface. After that, the light is focused toward the focal position on the rear side of the second projection lens arranged in the lamp optical axis direction on the front end side of the light source, and irradiated forward through the second projection lens. .

Therefore, the light emitted from the light source toward the front side is emitted forward through the second projection lens by the second reflecting surface that converges at the second focal position disposed in the tip side region of the light source. From the above, the use efficiency of light from the light source is improved, the total luminous flux forming the light distribution pattern is increased , and the plane mirror is arranged so as to intersect the optical axis of the light source in the tip side region of the light source, The light reflected by the third reflecting surface that reflects the reflected light from the second reflecting surface toward the focal position on the rear side of the second projection lens is projected into the second projection at a relatively small incident angle. Since it is incident on the lens, it is focused and irradiated relatively near the center toward the front, so that the maximum luminous intensity near the center of the light distribution pattern irradiated toward the front can be sufficiently increased. become.

Here, since the light source is disposed transversely to the optical axis, the entire lamp of the vehicle headlamp can be configured to be relatively short, and the light reflected by the first and second reflecting surfaces is Since each of the projection lenses is irradiated forward through the first and second projection lenses, the diameter and focal length of each projection lens can be selected to be smaller than that of a conventional monocular vehicle headlamp. .
Therefore, by reducing the focal length of each projection lens, the length of the entire vehicle headlamp in the optical axis direction can be further reduced, and by reducing the diameter of each projection lens, the vehicle headlamp can be reduced. The overall height can be reduced.

  Further, since the light from the light source is dispersedly incident on the plurality of projection lenses, heat concentration on each projection lens is avoided, so that the temperature increase of each projection lens can be suppressed. That is, the distance between each projection lens and the light source can be set shorter. Accordingly, it is possible to further reduce the length of the entire vehicle headlamp.

  Furthermore, by arranging a plurality of projection lenses side by side, it becomes possible to exhibit a novel appearance.

Furthermore, in front of the light source, a fourth projection lens disposed below or above the optical axis, a first focal position is disposed in the vicinity of the light emitting point of the light source, and a second focal position is defined above. It is arranged near the focal position on the rear side of the fourth projection lens, and reflects the light emitted from the light source to the lower side or the upper side of the rear side toward the focal position on the rear side of the third projection lens. And an ellipsoidal fourth reflecting surface to be focused, the light emitted from the light source to the lower side or the upper side is reflected by the fourth reflecting surface, and the second focal position, that is, The light is focused toward the rear focal position of the third projection lens, and further irradiated forward through the third projection lens.
As a result, the light use efficiency from the light source is further improved, so that the total luminous flux forming the light distribution pattern is further increased, and the maximum luminous intensity in the vicinity of the center of the light distribution pattern irradiated toward the front is increased. Can be further enhanced.

  A light-shielding shutter that forms a cut-off line that is disposed in the vicinity of the rear focal position of at least one of the first, second, and third projection lenses and that defines a predetermined light distribution pattern. In the case where it is provided, the shadow of the light-shielding shutter is projected forward by the light condensed near the rear focal position of the projection lens. A cut-off line will be formed.

  In the case where the light shielding shutter is formed in a plane perpendicular to the optical axis, or an arc shape or an ellipsoid shape curved from the optical axis toward the front side, the light distribution pattern is based on the shape of the light shielding shutter. A cut-off line will be formed.

When at least one light-shielding shutter has a slit hole at a position corresponding to the overhead sign, and this slit hole is shifted forward from the focal position on the rear side of the corresponding projection lens, By emitting light forward through the slit hole, light is irradiated to a sign or the like located on the upper front side, and the sign or the like can be easily recognized.
At that time, the slit hole is shifted from the focal point of the rear side of the corresponding projection lens to the front side, so that the outline of the image of the slit hole projected toward the front is blurred, thereby forming the slit hole. The appearance of the light distribution can be improved.

  When at least one of the first, second, and third projection lenses is configured as a Fresnel lens, the depth of the projection lens can be shortened. The axial length can be further shortened.

Thus, according to the present invention, the light source is disposed sideways, and the light emitted from the light source to the rear upper side, the lower side, and the front is reflected by the first, third, and second reflecting surfaces, respectively. By focusing toward the rear focal position of the first, third and second projection lenses, respectively, the light use efficiency from the light source is improved and the maximum luminous intensity near the center in the light distribution pattern is increased. As a result, the total luminous flux increases.
Further, since the light from the light source is dispersed and incident on the first, third and second projection lenses, the diameter of each projection lens can be reduced and the focal length thereof can be shortened. Can be reduced in size, and the entire vehicle headlamp can also be reduced in size.

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 is particularly limited in the following description. As long as there is no description of the effect, it is not restricted to these aspects.

[Example 1]
1 to 4 show a configuration of an embodiment of a vehicle headlamp according to the present invention.
1 to 4, a vehicle headlamp 10 is a headlamp on the left side when viewed from the traveling direction of an automobile, and includes a bulb 11 as a light source and a first reflector that reflects light from the bulb 11 forward. One main reflecting surface 12, a second main reflecting surface 13, a sub-reflecting surface 14 arranged facing the rear in front of the bulb 11, and reflected light from the sub-reflecting surface 14 toward the front A reflecting plane mirror 15, a first main projection lens 16, a second main projection lens 17 and a sub projection lens 18, a first main light shielding shutter 19, a second main light shielding shutter 20, and a sub light shielding shutter 21, It is composed of Hereinafter, with respect to the vehicle front-rear direction, the front direction is defined as + Z direction, the vehicle vertical direction is defined as + Y direction, and the lateral direction of the vehicle from the vehicle center toward the side is defined as + X direction.

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 metal halide lamp or the like is used and is fixedly held by a socket. In addition, power is supplied.
In the illustrated case, the bulb 11 uses, for example, an HID light source having a length of about 100 mm.

As shown in FIGS. 2 and 3, the bulb 11 is substantially transverse to the optical axis O extending horizontally in the longitudinal direction of the vehicle and outward toward the side of the vehicle body, that is, toward the + X direction. The light emitting center 11a is disposed on the optical axis O so that the tip extends.
Furthermore, the valve 11 is inserted and fixedly held by a predetermined means, for example, in the engine room from the inside of the vehicle center, that is, the -X side, at the time of mounting.

The first main reflection surface 12 is disposed on the upper side (+ Y region) behind the bulb 11 (−Z region).
Then, as shown in FIG. 4, the first main reflection surface 12 is formed in a concave shape toward the front so as to reflect the light emitted from the bulb 11 to the upper rear side toward the front. The first focal position F1 is located in the vicinity of the light emission center 11a of the bulb 11, and the second focal position F2a is formed on the elliptical reflecting surface so as to be located above the optical axis O on the front side. .
Here, the elliptical reflecting surface includes not only a rotating ellipsoid and an elliptic cylinder but also a free-form surface based on an ellipsoid.
As a result, the light emitted from the bulb 11 substantially upward in the −Z direction is reflected by the first main reflecting surface 12 and proceeds toward the focal position on the rear side of the first main projection lens 16 as will be described later. Further, the light passes through the first main projection lens 16 via the first main light-shielding shutter 19 and is emitted forward.

On the other hand, the second main reflecting surface 13 is disposed on the lower side (-Y region) behind the bulb 11 (-Z region).
As shown in FIG. 4, the second main reflecting surface 13 is formed in a concave shape toward the front so as to reflect the light emitted from the bulb 11 to the lower rear side toward the front. The first main reflecting surface 12 is positioned such that the first focal position F1 is located near the light emission center 11a of the bulb 11 and the second focal position F2b is located below the optical axis O on the front side. It is comprised from the same elliptical reflective surface.
As a result, the light emitted from the bulb 11 substantially downward in the −Z direction is reflected by the second main reflection surface 13 and directed toward the rear focal position of the second main projection lens 17 as will be described later. Further, the light passes through the second main projection lens 17 via the second main light-shielding shutter 20 and is emitted forward.

Here, the first main reflection surface 12 and the second main reflection surface 13 are actually composed of an assembly such as a strip-shaped spheroid or a free curved surface based on an ellipse, In order to improve the degree of freedom of light distribution design, reflecting surfaces such as different curvatures may be combined by being divided above and below the optical axes of the corresponding first and second main projection lenses 16 and 17.
The first main reflection surface 12 and the second main reflection surface 13 also generate diffused light not only in the optical axis O direction but also in the horizontal left and right sides in consideration of the road surface illumination light distribution pattern. It is configured as such.
Further, in the illustrated case, the first main reflecting surface 12 includes a so-called hot zone forming reflecting surface in a region located above the bulb 11.

The sub-reflecting surface 14 receives incident light from the bulb 11 or the main reflecting surfaces 12 and 13 to the first and second main projection lenses 16 and 17 respectively in front of the bulb 11 (+ Z region). It arrange | positions on the optical axis O so that it may not disturb.
The sub-reflecting surface 14 is formed in a concave shape toward the rear so that the light emitted from the bulb 11 to the front side is reflected obliquely in the + X direction toward the rear, and the first focal position F1 is the bulb. 11 is located in the vicinity of the light emission center 11a, and the second focal position F2c is located at a position conjugate to the rear focal position of the sub-projection lens 18 by the plane mirror 15 (or a nearby position). It consists of a system reflection surface.
As a result, the light emitted from the bulb 11 substantially in the + Z direction is reflected by the sub-reflecting surface 14, further reflected by the plane mirror 15, proceeds toward the focal position on the rear side of the sub-projecting lens 18, and further sub-shielded. The light passes through the sub-projection lens 18 via the shutter 21 and is emitted forward.
Similarly, the sub-reflecting surface 14 is configured to generate diffused light not only in the optical axis O direction but also in the horizontal left and right sides in consideration of the road surface illumination distribution pattern.

As shown in FIG. 2, the plane mirror 15 is disposed in an extended region (+ X direction) on the tip side of the bulb 11, reflects reflected light from the sub-reflection surface 14, and The inclination angle is set so as to converge toward the rear focal position, and in the illustrated case, it is arranged at approximately 45 degrees.
Here, the bulb 11 generally has a relatively low light emission intensity at the tip side and the base side, and receives light in the range of, for example, about 55 degrees with respect to the vertical plane passing through the light emission center 11a. A main reflection surface 12 and a second main reflection surface 13 are arranged. Accordingly, since the first main reflection surface 12 and the second main reflection surface 13 are not arranged on the distal end side of the bulb 11, the plane mirror 15 includes the first main reflection surface 12 and the second main reflection surface 12. There is no interference with the main reflecting surface 13.

  The first main projection lens 16 is composed of a convex lens, preferably an aspherical lens, and is focused on the light source side above the optical axis O and on the optical axis O1 parallel to the optical axis O. Are arranged in the vicinity of the second focal position F2a of the first main reflecting surface 12.

  The second main projection lens 17 is similarly composed of a convex lens, preferably an aspheric lens, on the optical axis O2 parallel to the optical axis O below the optical axis O. The focal point on the light source side is arranged so as to be located in the vicinity of the second focal position F2b of the second main reflecting surface 13.

  Further, the sub-projection lens 18 is similarly composed of a convex lens, preferably an aspheric lens, on the side of the optical axis O (+ X direction) on the optical axis O3 parallel to the optical axis O. The focal point on the light source side is arranged so as to be located at a conjugate position (near the focal point) by the second focal position F2c of the sub-reflecting surface 14 and the plane mirror 15.

The first main light-shielding shutter 19 is made of an opaque material, and its upper edge 19a is disposed near the focal position on the light source side of the first main projection lens 16.
The upper edge 19a of the first main light-shielding shutter 19 forms a cut-off line in a light distribution pattern of a passing beam, for example.
In the illustrated case, the first main light-shielding shutter 19 is formed such that both sides thereof are curved in an arc shape or an elliptical shape toward the corresponding first projection lens 16 side.
Here, the curved shape of the first main light-shielding shutter 19 is selected in consideration of the diffusion state in the horizontal direction of the light irradiated forward by the first main projection lens 16. Yes.
The first main light shielding shutter 19 may be formed in a flat plate shape.

The second main light-shielding shutter 20 is made of an opaque material, and its upper edge 20a is disposed near the focal position on the light source side of the second main projection lens 17.
The upper edge 20a of the second main light-shielding shutter 20 forms, for example, a cut-off line in a light distribution pattern of a passing beam.
In the illustrated case, the second main light-shielding shutter 20 is formed such that both sides thereof are curved in an arc shape or an elliptical shape toward the corresponding second projection lens 17 side.

Further, the sub light-shielding shutter 21 is made of an opaque material, and its upper edge 21 a is disposed in the vicinity of the focal position on the light source side of the sub-projection lens 18.
The sub-light-shielding shutter 21 has an upper edge 21a that forms a cut-off line in a light distribution pattern of a passing beam, for example.
In the case shown in the drawing, the sub light-shielding shutter 21 is formed such that both sides thereof are curved in an arc shape or an elliptical shape toward the corresponding sub projection lens 18 side.

Here, the second main light shielding shutter 20 and the sub light shielding shutter 21 are respectively provided with slit holes 20b and 21b.
These slit holes 20b and 21b each define a so-called overhead sign for satisfying the minimum illuminance from the horizontal to 4 degrees above the light distribution pattern.
The slit holes 20b and 20c are arranged such that their opening positions are shifted forward (+ Z direction) in order to blur the outline of the overhead sign.

  The vehicle headlamp 10 according to the embodiment of the present invention is configured as described above. When the bulb 11 is supplied with power and emits light, the light L1 emitted rearward from the bulb 11 is the first main light. Reflected by the reflecting surface 12, proceeds toward the second focal point F <b> 2 a, i.e., near the focal point on the rear side of the first main projection lens 16, and further passes through the first main light-shielding shutter 19 to the first main projection lens. While being focused by 16, it is irradiated forward.

  Further, the light L2 emitted from the bulb 11 to the lower rear side is reflected by the second main reflection surface 13 and is in the vicinity of the second focal point F2b, that is, the focal position on the rear side of the second main projection lens 17. Then, the light is irradiated forward while being focused by the second main projection lens 17 via the second main light-shielding shutter 20.

  Further, the light L3 emitted forward from the bulb 11 is reflected by the sub-reflecting surface 14, reflected by the corresponding flat mirror 15, and then proceeds toward the focal position on the rear side of the sub-projection lens 18, Further, the light is emitted forward while being focused by the sub projection lens 18 via the sub light shielding shutter 21.

  At that time, the light L1, L2, and L3 are respectively sent from the upper edges 19a, 20a, and 21a of the first main light-shielding shutter 19, the second main light-shielding shutter 20, and the sub-light-shielding shutter 21 to the projection lenses 16, 17, respectively. By being enlarged and projected forward by 18, a cut-off line in the light distribution pattern is formed, and a light distribution pattern of a passing beam is obtained.

Further, the lights L2 and L3 pass through the slit holes 20b and 21b of the light shielding shutters 20 and 21, thereby defining an overhead sign in the light distribution pattern. For example, a sign positioned on the upper front side of the vehicle To improve the visibility of these signs and the like.
At that time, the light from the bulb 11 is divided into three light beams L1, L2, and L3, and the light beams L2 and L3 have been confirmed to be weaker than the light beam L1. For this reason, even if an overhead sign is defined by the slit holes 20b and 20c with respect to the lights L2 and L3, the illuminance does not deviate from the specified value.

Further, since the bulb 11 is disposed sideways, the overall length of the lamp can be shortened, and the light from the bulb 11 is divided into three parts, which are directed forward by the three projection lenses 16, 17, and 18. Since it is irradiated, the light condensing property can be tripled, so that the focal length and diameter of each projection lens 16, 17, 18 can be reduced.
Thereby, since each projection lens 16, 17, 18 is configured in a small size, the vehicle headlamp 10 as a whole can have a shorter length in the optical axis direction and a smaller thickness in the vertical direction. The entire headlamp 10 can be downsized.

For example, the focal length of each projection lens 16, 17, 18 is about 15 to 40 mm, which is shorter than the focal length of the projection lens in the conventional monocular vehicle headlamp, and the diameter thereof is similarly about 20 to 50 mm, which is smaller. Can be selected.
Therefore, in combination with shortening the focal length of the elliptical reflecting surfaces 12, 13, and 14, the vehicle headlamp 10 can be shortened to 100 mm or less.

Furthermore, in the vehicle headlamp 10 having such a configuration, the amount of light incident on each projection lens 16, 17, 18 is dispersed, so that compared with a conventional monocular vehicle headlamp, respectively. It will be about one third.
Accordingly, since the heat generation in the projection lenses 16, 17, and 18 is also about one-third, the projection lenses 16, 17, and 18 can be made of resin.
At this time, by configuring each projection lens 16, 17, 18 as a Fresnel lens, the thickness of each projection lens 16, 17, 18 in the optical axis direction can be reduced by 10 mm or more, so the entire vehicle headlamp 10 can be reduced. The length in the optical axis direction can be further shortened.

FIG. 5 shows a simulation result of the light distribution pattern by the vehicle headlamp 10 described above.
Here, FIG. 5A shows a light distribution pattern by the light L <b> 1 reflected from the bulb 11 by the first main reflection surface 12 and emitted forward through the first main projection lens 16.
FIG. 5B shows a light distribution pattern by the light L <b> 2 reflected from the bulb 11 by the second main reflection surface 13 and emitted forward through the second main projection lens 17.
In this case, it can be seen that an overhead line is formed by the slit hole 20b of the second main light-shielding shutter 20.

On the other hand, FIG. 5C is emitted forward from the bulb 11, reflected by the sub-reflection surface 14, further reflected by the plane mirror 15, and emitted forward via the sub-projection lens 18. The light distribution pattern by the light L3 is shown.
In this case, it can be seen that the light distribution pattern is concentrated near the center, and an overhead line is formed by the slit hole 21b of the sub-light-shielding shutter 21.

Accordingly, the light distribution pattern of the entire vehicle headlamp 10 by the above-described lights L1, L2, and L3 is as shown in FIG. 6A, and the total luminous flux increases and the maximum luminous intensity near the center of the light distribution pattern. It can be seen that is sufficiently increased.
At that time, the light distribution pattern can obtain a brightness of about 1000 lm, which is equal to or higher than the entire light distribution pattern of the conventional monocular vehicle headlamp shown in FIG. 6B. The left and right diffusibility is also good, and an overhead sign can be secured.

In the embodiment described above, the vehicle headlamp 10 is configured as a so-called trinocular type, but is not limited to this, and the first main reflection surface 12, the first main projection lens 16, and the first main projection lens 16 are not limited thereto. It is also possible to omit the light shielding shutter 19 or omit the second main reflection surface 13, the second main projection lens 17, and the second main light shielding shutter 20.
In this case, the remaining second main reflecting surface 13 or first main reflecting surface 12 and sub-reflecting surface 14 can be enlarged to compensate for a reduction in light utilization efficiency from the bulb 11.
In this way, a twin-lens vehicle headlamp is configured, and a vehicle headlamp with a novel appearance can be provided.

  Further, in the above-described embodiment, the vehicle headlamp 10 is configured as a left headlamp for an automobile, but is not limited thereto, and is also configured as a right headlamp having a symmetric configuration. In addition, by configuring symmetrically with respect to the optical axis O, it is possible to provide a vehicle headlamp in a right-hand traffic area.

  Furthermore, in the above-described embodiment, the vehicle headlamp 10 is configured as a so-called headlamp, but is not limited thereto, and may be configured as an auxiliary headlamp such as a fog lamp.

  In the above-described embodiment, the slit holes 20b and 21b are provided for the second main light-shielding shutter 20 and the sub-light-shielding shutter 21, respectively. Of these, at least one slit hole may be provided, and none of the light-shielding shutters 19, 20, 21 may have a slit hole.

  Furthermore, in the above-described embodiment, the plane mirror 15 is used to focus the reflected light from the sub-reflecting surface 14 in the vicinity of the focal position of the sub-projection lens (second projection lens) 18. For example, a reflective surface other than a flat surface (such as a parabolic reflective surface) may be used. In that case, by making the focal position of the reflective surface be in the vicinity of the focal position of the sub-projection lens 18, even if the reflective surface is other than a flat surface, the same action as when the plane mirror 15 in the above-described embodiment is used. Can be played.

  The vehicle headlamp 10 according to the present invention is configured as a left headlamp for an automobile. However, the present invention is not limited thereto, and the present invention is applied to other types of vehicle headlamps including an auxiliary headlamp. Is possible.

  In this way, according to the present invention, the projector-type vehicle headlamp of the excellent bulb horizontal type, which has a simple configuration and reduces the depth of the entire lamp without reducing the brightness, is achieved. Can be provided.

It is a schematic perspective view which shows the structure of one Embodiment of the vehicle headlamp by this invention. It is the schematic plan view seen from the + Y direction which shows the vehicle headlamp of FIG. It is the schematic front view seen from the + Z direction which shows the vehicle headlamp of FIG. It is a schematic sectional drawing along the optical axis which looked at the vehicle headlamp of FIG. 1 from the + X direction. 1A shows a light distribution pattern by the first projection system, FIG. 1B shows a light distribution pattern by the second projection system, and FIG. 1C shows a light distribution pattern by the third projection system, respectively. It is a graph. (A) It is a graph which shows the whole light distribution pattern in the vehicle headlamp of FIG. 1, and (B) The whole light distribution pattern in the conventional vehicle headlamp, respectively. It is a schematic sectional drawing along the optical axis which shows the structure of an example of the conventional vehicle headlamp.

Explanation of symbols

10 Vehicle headlights 11 Bulb (light source)
12 1st main reflective surface (1st reflective surface or 4th reflective surface)
13 Second main reflecting surface (fourth reflecting surface or first reflecting surface)
14 Sub-reflective surface (second reflective surface)
15 Plane mirror (third reflective surface)
16 First main projection lens (first projection lens or third projection lens)
17 Second main projection lens (third projection lens or first projection lens)
18 Subprojection lens (second projection lens)
19 First main light shielding shutter 20 Second main light shielding shutter 20b Slit hole 21 Sub light shielding shutter 21b Slit hole

Claims (6)

A light source disposed horizontally on a lamp optical axis extending horizontally in the vehicle front-rear direction and having a light emission center positioned on the lamp optical axis;
At the front of the light source, a first projection lens disposed toward the lamp optical axis direction above or below the lamp optical axis,
A second projection lens disposed in front of the light source and in the lamp optical axis direction on the front end side of the light source;
The first focal position is arranged near the light emitting point of the light source, and the second focal position is arranged near the focal position on the rear side of the first projection lens, and the upper or lower side behind the light source. An ellipsoidal first reflecting surface that reflects the light emitted to the side and focuses it toward the focal position on the rear side of the first projection lens;
In front of the light source, the first focal position is arranged in the vicinity of the light emitting point of the light source, and the light emitted forward from the light source is reflected laterally to the tip side region of the light source, thereby leading the tip of the light source. a second reflecting surface Ru is focused on a second focal position arranged on the side areas,
A plane mirror disposed so as to intersect the optical axis of the light source in the tip side region of the light source, and the reflected light from the second reflection surface toward the focal position on the rear side of the second projection lens A third reflecting surface to be reflected;
Contains
The second reflecting surface is arranged such that the first focal position is in the vicinity of the light emitting point of the light source, and the second focal position is the third focal position on the rear side of the second projection lens. It is arranged near the conjugate position by the reflecting surface,
A vehicle headlamp characterized by that. Further, a third projection lens disposed in front of the light source, below or above the lamp optical axis,
The first focal position is disposed in the vicinity of the light emitting point of the light source, and the second focal position is disposed in the vicinity of the rear focal position of the third projection lens. An ellipsoidal fourth reflecting surface that reflects the light emitted upward and focuses it toward the rear focal position of the third projection lens;
The vehicle headlamp according to claim 1, further comprising:   A light-shielding shutter that forms a cut-off line that is disposed in the vicinity of the rear focal position of at least one of the first, second, and third projection lenses and that defines a predetermined light distribution pattern. The vehicle headlamp according to claim 1, wherein the vehicle headlamp is provided. 4. The front of the vehicle according to claim 3, wherein the light shielding shutter is formed in a plane perpendicular to the optical axis of the lamp , or in an arc shape or an ellipsoid shape curved from the optical axis toward the front side. Lighting.   At least one light-shielding shutter has a slit hole at a position corresponding to an overhead sign, and the slit hole is arranged to be shifted to the front side from the focal position on the rear side of the corresponding projection lens. The vehicle headlamp according to claim 3 or 4.   6. The vehicle headlamp according to claim 1, wherein at least one of the first, second, and third projection lenses is configured as a Fresnel lens.

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