JP4626618B2 - Vehicle headlamp lamp unit - Google Patents

Description

  The present invention relates to a lamp unit for a vehicle headlamp using an LED as a light source.

The lamp unit disclosed in Patent Document 1 includes an LED as a light source, a first reflecting surface that is arranged so as to cover the front side of the LED, and is based on an elliptical surface that has a first focal point matched with the LED, A second reflecting surface based on a parabolic surface reflecting reflected light from the reflecting surface to the front of the vehicle; and a third reflecting surface based on a parabolic surface reflecting direct light from the LED to the front of the vehicle. ing. The LED is directed in a direction in which its outgoing optical axis faces the first reflective surface (a direction substantially orthogonal to the optical axis of the first reflective surface). The reason why the outgoing optical axis of the LED is directed toward the first reflecting surface is that the outgoing optical axis with a large amount of light is directed toward the first reflecting surface and more light is reflected by the first reflecting surface.
JP 2006-19052 A

  However, in such a conventional technique, since the outgoing optical axis of the LED is directed in the direction facing the first reflecting surface, most of the light from the LED is reflected by the first reflecting surface. 2 It is guided to the reflection surface and reflected toward the front of the vehicle from there. And the remaining part which is not reflected by the 1st reflective surface is reflected toward the vehicle front by the 3rd reflective surface. That is, most of the light from the LED is reflected twice by the first reflecting surface and the second reflecting surface, and there is little light irradiated to the front of the vehicle by only one reflection of the third reflecting surface. In general, as the number of reflections increases, the light attenuates. Therefore, it cannot be said that the prior art can effectively use the light of the LED.

  The present invention has been made paying attention to such a conventional technique, and provides a lamp unit for a vehicle headlamp capable of effectively using light from an LED.

The invention according to claim 1 is a lamp unit for a vehicle headlamp , wherein a first reflecting surface based on a paraboloid having a focal point on a front lower side of the lamp unit, and the first reflecting surface. An LED as a light source disposed near the focal point and having an outgoing optical axis directed to the first reflection surface at the upper rear side, and an elliptical surface provided in a state of covering the LED from the upper front side and having the LED as the first focal point An auxiliary reflection surface based on the second reflection surface, a second reflection surface provided below the first reflection surface and based on a paraboloid focusing on the second focal point of the auxiliary reflection surface, and the auxiliary reflection surface A shade provided below the second focal point and having an edge near the second focal point of the auxiliary reflecting surface, wherein the reflected light from the auxiliary reflecting surface is partially cut at the edge. A light incident on the second reflecting surface with a predetermined light distribution pattern. And over de, it provided behind the lower side of the LED, and a plane mirror for reflecting light from the LED, is provided above the first reflecting surface and the focus of the symmetrical position with respect to the plane mirror of the LED And a third reflecting surface based on a parabolic surface.

According to the first aspect of the present invention, a large amount of direct light in the vicinity of the emission optical axis of the LED is directly guided to the first reflecting surface, and is reflected from the first reflecting surface as reflected light only once, to the front of the lamp unit. Can be irradiated. Since it irradiates ahead of a lamp unit only by reflection once, it can irradiate ahead of a lamp unit in the state which suppressed attenuation of light of LED, and can aim at effective use of light of LED. Further, according to the present invention, light that is emitted above the emission optical axis of the LED and is not originally effectively used is reflected by the auxiliary reflection surface with the LED as the first focal point and led to the second reflection surface, Since it can irradiate toward the front of the lamp unit, further effective utilization of the light of the LED can be achieved. Further, according to the present invention, the reflected light guided to the second reflecting surface is partially cut at the edge portion of the shade near the second focal point of the auxiliary reflecting surface, and has a predetermined distribution corresponding to the shape of the edge portion. The light pattern can be irradiated from the second reflecting surface to the front of the lamp unit. In addition, according to the present invention, light that is emitted downward from the emission optical axis of the LED and is not originally effectively used is reflected upward by the plane mirror disposed below the LED and guided to the third reflecting surface. From there, it can be irradiated toward the front of the lamp unit. Therefore, the LED light can be used more effectively.

  Hereinafter, a lamp unit of a vehicle headlamp according to an embodiment of the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited by this embodiment. In the drawings, the symbol “A” indicates the front side of the vehicle (the forward direction side of the vehicle). The symbol “B” indicates the rear side of the vehicle. The symbol “U” indicates the upper side, and “D” indicates the lower side. The symbol “L” indicates the left side when the front side is viewed from the driver side. The symbol “R” indicates the right side when the front side is viewed from the driver side. The symbol “VU-VD” indicates vertical lines on the top and bottom of the screen. Reference sign “HL-HR” indicates horizontal lines on the left and right of the screen.

  In the figure, reference numeral 1 denotes a lamp unit. The lamp unit 1 is arranged in plural (four in this example) on both the left and right sides of the front portion of the vehicle to constitute the left and right headlamps 2 (see FIG. 3). In this embodiment, one of them will be described as a representative.

  The four lamp units 1 are housed inside the headlamp 1 in a state of being partitioned via a partition wall 3. A transparent outer lens is provided on the front face of the headlamp 1. Each lamp unit 1 includes a reflector 4 and an LED 5 as a light source as a basic configuration.

  The reflector 4 is formed from a light-impermeable resin or the like, and has a shape that is vertically long and curved as a whole. On the front surface of the reflector 4, a third reflecting surface M3, a first reflecting surface M1, a second reflecting surface M2, a shade 6, and a plane mirror 7 are formed in this order from the top. A dome-shaped auxiliary reflection surface 9 having an opening at the rear upper portion is formed below the flat mirror 7. All of the first to third reflecting surfaces M1, M2, M3, the shade 6, the flat mirror 7, and the auxiliary reflecting surface 9 are mirror-finished by aluminum deposition or silver coating.

  A bottom surface portion 10 is formed on the auxiliary reflection surface 9, and the LED 5 is installed here. The auxiliary reflecting surface 9 is formed as an ellipsoid (or a free-form surface based on the ellipsoid) based on the first focus F1 and the second focus F2. A line segment L1 passing through the first focal point F1 and the second focal point F2 of the auxiliary reflecting surface 9 is inclined by an angle θ1 with respect to the horizontal axis H passing through the light emitting part of the LED 5. The horizontal axis H coincides with the traveling axis of the vehicle. Further, the outgoing optical axis (0 ° axis) X of the LED 5 is inclined with respect to the horizontal axis H at an angle θ2 larger than the line segment L1. The inclination angle θ2 of the outgoing optical axis X of the LED 5 is just an angle directed toward the center of the first reflecting surface M1.

  The first reflecting surface M1 is formed as a paraboloid (or a free-form surface based on the paraboloid) having the first optical axis Z1 parallel to the horizontal axis H as the optical axis and the first focal point F1 as a focal point. Yes.

  The second reflecting surface M2 is formed as a paraboloid (or a free-form surface based on the paraboloid) having the second optical axis Z2 parallel to the horizontal axis H as the optical axis and the second focal point F2 as a focal point. Yes. The focal point F2 of the second reflecting surface M2 (that is, the second focal point F2 of the auxiliary reflecting surface) is located on the second optical axis Z2.

  In front of the second reflecting surface M2, a shade 6 having an edge portion 6a whose center in the left-right direction coincides with the focal point F2 of the second reflecting surface (the second focal point F2 of the auxiliary reflecting surface) is formed. The edge portion 6a has a shape that is bent in a “shape”, and can form a light distribution pattern for passing.

  A flat mirror 7 is formed below the shade 6 and below the line segment L1 and parallel to the line segment L1. The flat mirror 7 is continuous with the bottom surface portion 10.

  The third reflecting surface M3 formed above the first reflecting surface M1 is a paraboloid (or paraboloid) having the third optical axis Z3 parallel to the horizontal axis H as the optical axis and the pseudo focal point f1 as the focal point. Free-form surface). The pseudo focal point 1 is in a symmetrical position with the first mirror F 1 matched with the light emitting part of the LED 5 and the plane mirror 7 interposed therebetween, and the light from the LED 5 becomes the light as if it is emitted from the pseudo focal point f 1 and is third reflected. Guided to the surface M3. The third reflecting surface M3 has a longer focal length, and has a horizontal cross section that is easier to diffuse light in the vehicle width direction than the first reflecting surface M1 and the second reflecting surface M2.

  The LED 5, the auxiliary reflecting surface 9, and the plane mirror 7 are disposed below the reflecting surfaces M1, M2, and M3 (that is, below the second optical axis Z2).

  Next, the operation of this embodiment will be described. The light emitted from the LED 5 becomes three kinds of light S1, S2, and S3 reflected by the first reflecting surface M1, the second reflecting surface M2, and the third reflecting surface M3, respectively, and synthesized as shown in FIG. Light distribution patterns HP1, HP2, and HP3 are applied to the front of the vehicle.

  First, the light S1 emitted from the LED 5 in the direction of the outgoing optical axis X is guided directly to the first reflective surface M1 as the outgoing optical axis X of the LED 5 is directed to the center of the first reflective surface M1. . In general, the light distribution curve of the light emitted from the LED 5 is maximum near the outgoing optical axis (0 ° axis) X of the LED 5, and the luminous intensity decreases as the angle from the outgoing optical axis X increases. Light having high luminous intensity from the LED 5 is directly introduced into the first reflecting surface M1, and is irradiated from the first reflecting surface M1 to the front of the vehicle with a predetermined light distribution pattern HP1 shown in FIG. This light distribution pattern HP1 is a basic pattern. Since the light is irradiated forward of the vehicle by only one reflection from the first reflecting surface M1, it is possible to irradiate the front of the vehicle while suppressing the attenuation of the light of the LED 5, and the light of the LED 5 can be effectively used.

  Next, the light S <b> 2 emitted upward from the emission optical axis X of the LED 5 is reflected by the auxiliary reflecting surface 9 and almost goes to the second focal point F <b> 2. Since the edge portion 6a of the shade 6 exists at the second focal point F2, the light S2 from the auxiliary reflecting surface 9 is partially cut by the edge portion 6a. Then, as shown in FIG. 7, a predetermined light distribution pattern (passing light distribution pattern) HP2 corresponding to the shape of the edge portion 6a is formed, and the light is irradiated from the second reflecting surface M2 toward the front of the vehicle. In this way, the light S2 that is emitted upward from the emission optical axis X of the LED 5 and is not effectively used by itself is reflected by the auxiliary reflecting surface 9 and guided to the second reflecting surface M2, and from there as a predetermined light distribution pattern HP2. Since it can irradiate toward the front of a vehicle, the further effective utilization of the light of LED5 can be aimed at.

  Next, the light S3a emitted toward the lower side than the outgoing optical axis X of the LED 5 is reflected by the flat mirror 7 and guided to the third reflecting surface M3. The light S3 reflected by the plane mirror 7 becomes the light S3a as if it was emitted from the pseudo-focus f1 at a symmetrical position across the plane mirror 7 of the first focus F1 that matches the light emitting portion of the LED 5. The light is guided to the third reflecting surface M3 and emitted toward the front of the vehicle as the light distribution pattern HP3 from the third reflecting surface M3. In this way, the light S3 that is emitted below the emission optical axis X of the LED 5 and is not effectively used by itself is reflected upward by the plane mirror 7 disposed below the LED 5 and led to the third reflecting surface M3. Since it can irradiate toward the vehicle front from there, the further effective utilization of the light of LED5 can be aimed at.

  Further, since the LED 5, the auxiliary reflecting surface 9, and the plane mirror 7 are disposed below the reflecting surfaces M1, M2, and M3 (that is, below the second optical axis Z2), these 5 and 9 and 7 are Further, the light reflected from the reflecting surfaces M1, M2, and M3 is not blocked, and the light from the LED 5 can be used more effectively.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment, and various modifications can be made.

The sectional side view which shows the lamp unit which concerns on embodiment of this invention. The perspective view which shows the schematic structure of a reflector. The front view which shows a headlamp. Sectional drawing which shows the periphery of LED. The figure which shows the light distribution pattern which synthesize | combined all the reflective surfaces. The figure which shows the light distribution pattern of a 1st reflective surface. The figure which shows the light distribution pattern of a 2nd reflective surface. The figure which shows the light distribution pattern of a 3rd reflective surface.

Explanation of symbols

1 Lamp Unit 2 Headlamp 3 Bulkhead 4 Reflector 5 LED (Light Source)
6 Shade 6a Edge portion 7 Flat mirror 9 Auxiliary reflection surface 10 Bottom portion X LED outgoing optical axis F1 First focal point F2 Second focal point f1 Pseudo focal point K1 First optical axis K2 Second optical axis K3 Third optical axis M1 First Reflection surface M2 Second reflection surface M3 Third reflection surface S1 Light from the first reflection surface S2 Light from the second reflection surface S3 Light from the third reflection surface HP1 Light distribution pattern of the first reflection surface HP2 Second reflection surface Light distribution pattern of HP3 Light distribution pattern of third reflecting surface θ1 Angle of second optical axis θ2 Angle of optical axis of LED

Claims (1)

A vehicle headlamp unit ,
A first reflecting surface based on a paraboloid having a focal point on the front lower side of the lamp unit ;
An LED as a light source disposed in the vicinity of the focal point of the first reflecting surface and having an outgoing optical axis directed to the first reflecting surface on the upper rear side ;
An auxiliary reflecting surface provided in a state of covering the LED from the upper front side and based on an ellipsoid having the LED as a first focal point ;
A second reflecting surface provided below the first reflecting surface and based on a paraboloid focusing on the second focal point of the auxiliary reflecting surface ;
A shade provided below the second focal point of the auxiliary reflecting surface and having an edge portion in the vicinity of the second focal point of the auxiliary reflecting surface, wherein the reflected light from the auxiliary reflecting surface is partially at the edge portion. A shade that is cut and incident on the second reflecting surface with a predetermined light distribution pattern ;
A flat mirror that is provided on the lower rear side of the LED and reflects light from the LED;
A third reflecting surface provided above the first reflecting surface and based on a paraboloid focusing on a symmetrical position of the LED with respect to the plane mirror;
A lamp unit for a vehicle headlamp, comprising:

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