JP4809635B2 - Vehicle headlamp - Google Patents

Description

  The present invention relates to a lamp suitable for a vehicular lamp including a vehicle headlamp using at least one light emitting element.

With the recent improvement in luminous efficiency of white LEDs, various vehicle headlamps using white LEDs as light sources have been proposed.
A vehicle headlamp using such an LED is configured, for example, as shown in FIG.

  That is, in FIG. 2, a vehicle headlamp 1 is a so-called projector-type vehicle headlamp, and includes a light source 2 composed of at least one LED and a reflector 3 that reflects light from the light source forward. The projection lens 4 for converging the light reflected by the reflector 3 and the light-shielding portion 5 for forming a cut-off for passing light distribution.

The light source 2 is composed of at least one LED 2b mounted on a substrate 2a.
The surface of the substrate 2 a is disposed along an optical axis that extends substantially horizontally toward the front of the vehicle headlamp 1, that is, the projection lens 4.

In addition, the substrate 2a is configured such that two LEDs 2b mounted on one side are arranged back to back as shown in FIG. 2, or the LEDs 2b are mounted on both sides of a double-sided substrate.
Each LED 2b is mounted on the substrate 2a so that its central axis (light emission optical axis) is substantially perpendicular to the surface of the substrate 2a.

  The reflector 3 is composed of, for example, a spheroid, and the LED 2a of the light source 2 is further positioned near the first focal position F1 so that the long axis thereof coincides with the optical axis O of the vehicle headlamp 1. The emission center is arranged.

  The projection lens 4 is composed of, for example, an aspherical convex lens, and is disposed such that the focal position on the light source side is located in the vicinity of the second focal position F2 of the reflector 3.

  The light-shielding portion 5 is disposed near the focal position of the projection lens 4 on the light source side, that is, near the second focal position F2 of the reflector 3, and the upper edge 5a forms, for example, a cut-off line of a low beam. It has become.

According to the vehicle headlamp 1 having such a configuration, the light emitted from the light source 2 is reflected by the reflector 3, travels toward the second focal point F <b> 2 of the reflector 3, and then converged by the projection lens 4. Irradiate forward.
At this time, a cut-off is formed by the light-shielding portion 5 so as to illuminate a range of a so-called passing beam light distribution pattern.

  By the way, in these vehicle headlamps 1, the long axis of the reflector 3 coincides with the optical axis O of the projection lens 4 as described above, so that the reflected light traveling forward from the reflector 3 is not disturbed. The reflecting surface of the reflector 3 is formed relatively short in the front-rear direction.

Therefore, with respect to the light L1 reflected near the front edge of the reflector 3, the distance B2 from the reflection position to the light shielding portion 5 is relatively long with respect to the distance A1 from the light source 2 to the reflection position of the reflector 3. .
As a result, the projection image of the light source 2 projected forward through the projection lens 4 is enlarged as indicated by reference numeral X1 in FIG. 3, so that the light condensing range becomes relatively wide. For this reason, the vehicle headlamp 1 having such a configuration is unsuitable for obtaining a condensing characteristic that is focused in the center as a spot.

The LEDs 2b of the light source 2 are aligned in a direction perpendicular to the optical axis O on the substrate 2a.
By the way, generally, an LED has a large amount of emitted light on its central axis. Therefore, in the configuration described above, the light emitted from the LED is not effectively guided to the projection lens 4, and the utilization efficiency of the light from the LED 2b is reduced.

  Such a problem occurs not only in the case of the LED but also in the case where another type of light emitting element that emits light from the light source center to one side in the vertical direction is used.

  In view of the above, the present invention provides a lamp such as a vehicular lamp using a light emitting element as a light source, which can irradiate light within a relatively narrow light collection range with a simple configuration. It is an object.

The above object is achieved according to the present invention, a light source at least one light emitting element is mounted on a substrate, the light from the light source to reflect forward, emission its first focal point is the light source located near the center, with its second focus is positioned in front of the first focus, and continuous rotating elliptic reflecting surface of the one formed only on one side of the central axis, the light source side located near the second focal position of the focal position wherein the spheroidal reflecting surface, the optical axis comprise a projection lens comprising a convex lens which extends substantially horizontally toward the front, the substrate of the light source, The vehicular headlamp is disposed along the long axis of the spheroid reflection surface, and the long axis of the spheroid reflection surface is rearward from the second focal position to the other side. together are arranged inclined to the substrate of the light source, With the long axis of the rotating elliptic reflecting surface that is obliquely disposed so that its surface is inclined toward the rear, the spheroidal reflecting surface is, from the reflection position near the front end of the rotating elliptic reflecting surface as the distance from the from the length of the to the second focus position the light source to the reflection position near the front end of the rotating elliptic reflecting surfaces increases, its front end extends towards the front, the rotary ellipsoidal reflecting The long axis of the spheroid reflection surface is rearward from the second focal position so that the light from the light source reflected near the front end of the surface transmits near the lower end of the projection lens. This is achieved by a vehicular headlamp characterized in that the vehicle headlamp is arranged at an inclination .

  In the lamp according to the present invention, preferably, the projection lens is composed of an aspheric lens.

  The lamp according to the present invention is preferably configured such that a part of the light traveling from the reflector toward the projection lens is blocked by the upper edge to form a cut-off suitable for a predetermined light distribution pattern. A light-shielding portion is provided near the focal point.

  In the lamp according to the present invention, preferably, the one side is an upper side and the other side is a lower side.

  In the lamp according to the present invention, preferably, the one side is the left side or the right side, and the other side is the right side or the left side.

  In the lamp according to the present invention, preferably, the lamp is a vehicle lamp, particularly a vehicle headlamp, and the light shielding portion forms a cut-off corresponding to a light distribution pattern of a low beam.

  According to the said structure, the light radiate | emitted from the light source is reflected by the reflector, and advances, converging toward the 2nd focus. Then, the light that has passed through the second focal point, that is, the focal point on the light source side of the projection lens, enters the projection lens while being diverged, and is refracted and converged by the projection lens to be irradiated forward.

  In this case, since the light source and the reflector are inclined obliquely to the rear side, the front edge of the reflector can be formed relatively long in the optical axis direction. Accordingly, among the light from the light source, the luminous flux of the light reflected by the reflector is increased, so that the utilization efficiency of the light irradiated toward the front is improved.

  The reflector has a front end extending forward so that the distance from the light source to the reflection position near the front end of the reflector is longer than the distance from the reflection position to the second focal position. Since the virtual image of the light source by the light from the light source 11 incident on the projection lens is located farther from the rear side of the projection lens, the projection image of the light source reflected by the reflector and projected forward by the projection lens is obtained. Since it can be formed smaller, it is possible to obtain a smaller spot light distribution.

  When the projection lens is composed of an aspheric lens, the aberration of the projection image of the light source projected forward by the projection lens is reduced, and a desired projection image is obtained.

  A light-shielding portion disposed near the second focal point of the reflector so as to form a cut-off suitable for a predetermined light distribution pattern by blocking a part of the light traveling from the reflector toward the projection lens by the upper edge. In the case of being provided, a part of the light reflected by the reflector and directed to the projection lens is cut off by the light shielding part, and the cutoff line by the light shielding part is focused by the projection lens. Projected forward. As a result, the cut-off line image is formed at a predetermined distance in front, whereby light is irradiated with a predetermined light distribution pattern, for example, a low beam light distribution pattern.

  In the case where the one side is the upper side and the other side is the lower side, the reflector and the light source are arranged to be inclined downward, so that it is easy to reduce the size in the left-right direction.

  When the one side is the left side or the right side and the other side is the right side or the left side, the reflector and the light source are inclined to the left side or the right side. The size can be easily reduced in the vertical direction.

  When the lamp is a vehicular lamp, particularly a vehicle headlamp, and the light-shielding portion forms a cut-off corresponding to the light distribution pattern of the passing beam, an LED is used as a light source, and the lamp is small. In addition, a vehicle headlamp without color separation can be configured.

  In this way, according to the present invention, with respect to the light emitted forward from the light source composed of the light emitting element, more light is reflected by the reflector and incident on the projection lens, and from the light source to the leading edge of the reflector. By making the optical path length to the vicinity longer than the optical path length to the vicinity of the second focal point of the light reflected near the front edge of the reflector, the projection image of the light source projected forward is reduced in size and smaller. A high luminous intensity spot light distribution can be realized.

Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to FIG.
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 a configuration of an embodiment of a vehicular lamp to which the present invention is applied.
That is, in FIG. 1, a vehicle headlamp 10 is a so-called projector-type vehicle headlamp, and includes a light source 11 composed of at least one LED and a reflector 12 that reflects light from the light source 11 forward. And a projection lens 13 for converging the light reflected by the reflector 12, and a light shielding part 14 for forming a cutoff for passing light distribution.

The light source 11 is composed of at least one LED 11b mounted on the substrate 11a.
Here, the substrate 11a is inclined by an inclination angle θ with respect to an optical axis O extending substantially horizontally toward the front of the vehicle headlamp 10, that is, the projection lens 13, so that the rear side is lowered downward, as will be described later. Are arranged.
Each LED 11b is mounted on the substrate 11a such that its central axis (light emission optical axis) is substantially perpendicular to the surface of the substrate 11a.

  The reflector 12 is composed of, for example, a spheroid surface, and the long axis 12a of the LED 11b of the light source 11 is arranged in the vicinity of the first focal point F1 so that the rear side thereof is lowered downward with respect to the optical axis O. The emission center is located and the second focal point F2 is located on the optical axis O.

  In addition, the reflector 12 is formed only on the upper side of the long axis 12a, and its front edge is cut out so as not to block light reflected by the reflector 12 and traveling forward. Since 12a is inclined downward on the rear side, it can extend relatively forward.

  Further, the reflector 12 has a distance A2 from the light source 11 to the reflection position from the reflection position to the second focal point F2 of the reflector 12 with respect to the light L2 emitted from the light source 11 and reflected near the front edge thereof. It is formed so as to be longer than the distance B2.

  The projection lens 13 is composed of, for example, an aspherical convex lens, and is disposed such that the focal position on the light source side is located in the vicinity of the second focal position F2 of the reflector 12.

At least the surface of the light-shielding portion 14 is made of an opaque material, and the upper edge 14a thereof is near the focal position on the light source side of the projection lens 13, that is, near the second focal position F2 of the reflector 12. It is arranged to be located.
The light shielding portion 14 has an upper edge 14a that forms a desired light distribution pattern, that is, a cut-off line of a low beam, for example.

The vehicular lamp 10 according to the embodiment of the present invention is configured as described above, and the light emitted from the light source 11 is reflected by the reflector 12 when each LED 11b of the light source 11 is fed and emits light. Proceed toward the second focal point F2.
At this time, since the light source 11 and the reflector 12 are arranged to be inclined slightly rearward, the light emitted from the light source 11 can be reflected by the reflector 12 and enter the projection lens 13 with relatively high use efficiency. It will be.

The light that has passed through the second focal point F2 is irradiated forward while being focused by the projection lens 13.
At that time, a part of the light traveling from the reflector 12 toward the projection lens 13 is blocked by the light shielding portion 14, so that a cutoff is formed, and the image is projected forward by the second reflecting surface 13. Since the image is formed at a predetermined distance, for example, a light distribution pattern of a passing beam is provided.

Here, as described above, since the distance A1 from the light source 11 to the reflection position near the front end of the reflector 12 is longer than the distance B2 from the reflection position to the second focal position F2, the reflector 12 projects to the projection lens. The virtual image of the light source due to the light from the light source 11 incident on 13 is located farther from the projection lens 13 on the rear side.
Therefore, the projected image of the light source reflected by the reflector 12 and projected forward by the projection lens 13 can be formed smaller, so that a smaller spot distribution is obtained as indicated by reference numeral X2 in FIG. It is possible to obtain light.

  In this way, according to the vehicular lamp 10 according to the present invention, the light from the LED 11b of the light source 11 is reflected by the reflector 12, toward the second focus F2, that is, the vicinity of the focus on the light source side of the projection lens 13. Irradiate, converge and irradiate forward by the projection lens 13, and part of the light from the reflector 12 toward the projection lens 13 is blocked by the light shielding unit 14, thereby forming the shape of the upper edge 14 a of the light shielding unit 14. That is, by forming an image of the cut-off line at a predetermined distance in front by the projection lens 13, a predetermined light distribution pattern, for example, a light distribution pattern of a low beam can be formed by a relatively small spot light distribution.

As described above, in the vehicular lamp 10 according to the present embodiment, the light source 11 is inclined and the distance A2 from the light source to the point reflected by the reflector 12 is the focal point of the projection lens 13 from the reflector 13 (reflector 12). The second focal point) is longer than the distance B2 to the vicinity.
As shown in FIG. 1, the vehicular lamp 10 allows the light irradiated from the projection lens 13 to have a compact and high-density luminous intensity (a spot-like light distribution is obtained) as shown in FIG. That is, the characteristics of the LED light source that emits light in a single direction.
First, in order to obtain a spot-like light distribution, the angle between the light incident on the projection lens 13 focused in the vicinity of the light shielding portion 14 and the optical axis O of the projection lens 13 is set to 45 ° or less. It is desirable. In addition, in order to obtain light having a strong luminous intensity suitable for spot-like light distribution, when the light source 2 is arranged coaxially with the optical axis O as in the conventional lamp 1, the size of the reflector 2 is increased. An attempt was made to obtain a spot-like light distribution by increasing the distance A1.
However, with such a configuration, the reflector 2 is large in the conventional technique, and the distance B from the reflector 2 to the vicinity of the focal point of the projection lens 4 is also long, so that the overall structure of the lamp is large in both the width and depth directions. It had become. That is, a projector lamp using a light source that emits light on both sides, such as a conventional halogen lamp or HID, cannot adopt the structure of the present embodiment for obtaining a spot-like light distribution, as shown in FIG. Because of the structure, only a light distribution with poor light condensing property and insufficient distance visibility was obtained as in X1 shown in FIG.
Therefore, in the present invention, by using a single-sided light source called LED, the light source 11 can be inclined (angled) with respect to the projection lens 13 (optical axis O), and the diameter of the reflector 12 can be reduced. The configuration of the entire lamp can be made compact while taking the distance A2 longer than B2 without increasing it. Further, by making the distance A2 longer than B2 , the vehicle lamp 10 can guide the light to the projection lens 13 by a single reflection. Light distribution can be obtained.
Further, by adopting the configuration as in the present embodiment, the vehicular lamp also improves the degree of freedom of arrangement when mounted on the vehicle, so that the heat of the heat sink for the LED, for example, is easily reversed from FIG. It is also possible to arrange the light source on the top or to arrange to easily take in air introduced from the grill.

  In the above-described embodiment, an LED is used as a light emitting element constituting the light source 11, but is not limited thereto, and may be a small light source using another type of light emitting element such as a laser element. .

In the above-described embodiment, the light source 11 and the reflector 12 are arranged with the rear inclined downward with respect to the optical axis O of the projection lens 13, but the present invention is not limited thereto, and the light source 11 and the reflector 12 are not limited thereto. However, the rear may be arranged to be inclined leftward or rightward with respect to the optical axis of the projection lens 13.
In this case, corresponding to this inclination direction, the reflector 12 is formed only on the side opposite to the inclination direction, and the LED 11b is arranged so that the light source 11 has a light emitting optical axis directed to the opposite side to the inclination direction. Will be.

  Furthermore, in the above-described embodiment, the vehicle headlamp 10 is simply described. However, the present invention is not limited to this, and the vehicle headlamp can be used for, for example, a headlamp, a bending lamp, a fog lamp, and the like. It is apparent that the present invention can be applied to a vehicular lamp such as an auxiliary headlamp, and other lamps for general lighting.

It is a schematic side view which shows the structure of one Embodiment of the vehicle headlamp by this invention. 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 by the vehicle headlamp of FIG.1 and FIG.2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Vehicle lamp 11 Light source 11a Board | substrate 11b LED
12 reflector 13 projection lens 14 light-shielding part 14a upper edge

Claims (6)

A light source at least one light emitting element is mounted on a substrate, so as to reflect light from the light source toward the front, situated in the light emission near the center of the first focus the light source, the second A continuous focal ellipsoidal reflecting surface that is formed in front of the first focal point and formed only on one side of the central axis;
A projection lens composed of a convex lens whose focal position on the light source side is located in the vicinity of the second focal position of the spheroid reflection surface and whose optical axis extends substantially horizontally toward the front,
A vehicle headlamp , wherein the light source substrate is disposed along the major axis of the spheroid reflection surface ,
The major axis of the spheroid reflection surface is inclined to the other side toward the rear from the second focal position, and
Substrate of the light source, with the long axis of the tilted the rotating elliptic reflecting surface being disposed such that a surface is inclined toward the rear,
The spheroid reflection surface is
As the distance from the light source than the distance until said second focal position from the reflective position of the vicinity of the front end of the rotating elliptic reflecting surface to the reflection position near the front end of the rotating elliptic reflecting surfaces increases, its front end Extending forward ,
The long axis of the spheroid reflection surface is rearward from the second focal position so that light from the light source reflected near the front end of the spheroid reflection surface transmits near the lower end of the projection lens. A vehicle headlamp characterized by being inclined toward the other side toward the vehicle . The vehicle headlamp according to claim 1, wherein the projection lens includes an aspheric lens. The part of the light toward the projection lens from the reflector and blocked by the upper edge, so as to form a cut-off suitable for a predetermined light distribution pattern, the second light shielding portion arranged in the vicinity of the focal point of the reflector The vehicle headlamp according to claim 1, wherein the vehicle headlamp is provided . The one side a top, characterized in that the other side is the lower side, the vehicle headlamp according to any one of claims 1 to 3. The one side is a left or right side, wherein the other side is the right or left, the vehicle headlamp according to any one of claims 1 to 3. The vehicle headlamp according to claim 3 , wherein the light shielding portion forms a cut-off corresponding to a light distribution pattern of a passing beam.

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