JP4814821B2 - Variable light distribution headlight - Google Patents

Description

  The present invention relates to a headlight for a vehicle, and more specifically, a variable that can switch between a passing beam light distribution and a traveling beam light distribution in a single light source such as a metal halide discharge lamp. This relates to the configuration of the light distribution type headlight.

  FIG. 7 shows an example of the configuration of the conventional variable light distribution type headlight 90 of this type. First, in the case of normal city driving, as shown in FIG. A light source 92a is set in front of the focal point f3 of the low beam reflecting mirror 91L, and a light source 92 such as a metal halide discharge lamp is installed.

  Accordingly, the light emitted from the light emitting source 92a is appropriately directed downward by the upper half of the low beam reflecting mirror 91L, irradiates a road surface relatively close to the vehicle, and is a light distribution suitable for running in an urban area. Since the upward light is not included, the driver of the oncoming vehicle is not dazzled.

  Here, the reference numeral 91H in the figure denotes a traveling beam reflecting mirror, and this traveling beam reflecting mirror 91H is formed as a parabolic reflecting surface whose focal point is matched with the center of the light emitting source 92a. Yes. Therefore, since the light from the light emitting source 92a reflected by the traveling beam reflecting mirror 91H is irradiated in the horizontal direction, there is a high possibility that the driver of the oncoming vehicle is dazzled.

  Therefore, a movable hood 94 is provided in a fixed hood 93 that covers the light source 92 from the front in order to shield light directly emitted from the light emitting source 92a. A light source 92a is covered with a hood 94 and shielded so that light does not reach the traveling beam reflecting mirror 91H (see FIG. 9).

When it is necessary to travel with a traveling beam distribution such as on an expressway, the movable hood 94 is accommodated in a fixed hood 93 by a solenoid 95 or the like, and the traveling beam reflector 91H also emits light. It is assumed that the light from 92a reaches and a traveling beam light distribution that is easy to confirm from a distance can be obtained (see FIG. 8).
JP 2001-319506 A

  However, in the above-described conventional variable light distribution type headlight 90, first, the traveling beam reflecting mirror 91H is installed outside the passing beam reflecting mirror 91L, and the light beam from the light source 92a. Since the distance becomes longer, the size of the light emitting source 92a projected onto the traveling beam reflecting mirror 91H is also reduced, and even when switching from the passing beam shown in FIG. 9 to the traveling beam shown in FIG. There is a problem that the brightness when used for far-distance illumination cannot be obtained.

  Second, when switching to the traveling beam, the light certainly reaches the traveling beam reflecting mirror 91H, but the state in which the light still reaches the passing beam reflecting mirror 91L is still present. The road surface that is relatively close to the vehicle remains bright because it continues, and there is also a problem that the driver cannot obtain a clear switching feeling between the passing beam and the traveling beam. .

The present invention, as a specific means for solving the conventional problems described above, the movable light shielding plate is provided to change the state of the light from the light source to the fixed hood reaches reflection mirror, the reflection by the movable shielding plate In a variable light distribution type headlight that switches between passing beam distribution and traveling beam distribution according to a change in the state of light from the light source reaching the mirror, the light emitting source is the first focal point in the fixed hood. fixed elliptic reflecting surface for a bifocal and down direction of the light source is provided, the movable ellipse wherein the movable light shielding plate to the light-emitting source after section first focus and to the fixed elliptic reflecting surface second focus substantially the same position system reflecting surface and is provided, the variable light distribution type below the light source, characterized in Tei Rukoto main reflection surface is provided with a parabolic to a substantially horizontal irradiation direction and focus the second focus Resolving issues by providing headlights Is shall.

  According to the present invention, a fixed ellipsoidal reflecting surface and a movable ellipsoidal reflecting surface are provided exclusively for the passing beam and the traveling beam. When each beam is irradiated, a dedicated elliptical reflecting surface is provided for each beam. By selecting and using the surface, for example, when using a low-pass beam, the second focal point is located at an optimal position to obtain a low-pass beam with respect to the reflector, making it more ideal. It is assumed that light distribution characteristics can be obtained.

  In addition, the two elliptical reflecting surfaces of the fixed ellipsoidal reflecting surface and the movable elliptical reflecting surface can adopt the same distance between the focal points of each other, so that the light source image when projected onto the reflecting mirror can be used. Since the sizes are almost the same and the change in the irradiation direction can be clearly felt at the time of switching, the user does not feel uncomfortable.

  Below, this invention is demonstrated in detail based on embodiment shown in a figure. 1 is a variable light distribution type headlight according to the present invention. The variable light distribution type headlight 1 is a light source 2 having only one light source 2a such as a discharge lamp as a light source 2, for example. Is the same as that of the conventional example in that the single light emitting source 2a is of a variable light distribution type in order to form a passing beam and a traveling beam.

  Accordingly, the light source 2 is provided with a fixed hood 3 for shielding light directly directed forward, and a movable hood 4 is provided in the fixed hood 3 to move the movable hood 4. Thus, a passing beam and a traveling beam are formed. Here, in this invention, it is set as the structure by which the two rotation ellipsoids are accommodated in the said fixed hood 3, and one is formed also using a part of the said fixed hood 3, if needed. The fixed elliptical reflecting surface 3a.

  In addition, when the shape of the fixed hood 3 becomes complicated and difficult to form when formed as described above, the fixed elliptical reflective surface 3a or a part thereof is formed as a separate member and then welded or the like. It can be freely integrated with the fixed hood 3 to have a desired shape.

  At this time, the fixed elliptical reflecting surface 3a has the center of the light source 2a of the light source 2 as the first focal point fx and the second focal point f2 as appropriate downward. The position of the second focal point f2 will be described again in detail when the main reflector 5 described later is described.

  The main reflecting surface 5 is formed as a parabolic system having the second focal point f2 as a focal point. The paraboloidal axis is horizontal with respect to the state attached to the vehicle. Therefore, the light reflected from the fixed elliptical reflecting surface 3a out of the light emitted from the light source 2a irradiates the front in the horizontal direction of the vehicle after passing through the vicinity of the second focal point f2.

  In reality, since the fixed hood 3 and the like are present in the vicinity in the vicinity of the main reflecting surface 5, the main light is prevented from being blocked by these obstacles. The focal length of the reflecting surface 5 is determined as appropriate.

  As described above, in the variable light distribution headlight 1 according to the present invention, when the movable elliptical reflecting surface 4a, which is the movable hood 4, is not operated, the main reflecting surface 5 is irradiated in a substantially horizontal direction and is distant. The traveling beam distribution with excellent visibility is irradiated.

  Here, as shown in FIG. 2, when the movable elliptical reflecting surface 4a, which is the movable hood 4, is operated, the movable elliptical reflecting surface 4a is installed at a predetermined position along with the operation of the movable hood 4. Become. At this time, the movable elliptical reflecting surface 4a has the first focal point fy set at the rear end of the light source 2a, and the second focal point f2 is at the same position as the fixed elliptical reflecting surface 3a, that is, at the focal point f2. Is set.

  In addition, the movable elliptical reflecting surface 4a is appropriately reduced in size as compared with the fixed elliptical reflecting surface 3a, and when the movable elliptical reflecting surface 4 is driven, the movable elliptical reflecting surface 4a is formed. The system reflection surface 4a enters the inside of the fixed elliptical reflection surface 3a, and blocks light from the light source 2 (light emission source 2a) that has reached the fixed reflection surface 3a.

  By doing so, the optical path of the light obtained by the movable elliptical reflecting surface 4 is less inclined than the case of the fixed elliptical reflecting surface 3a, that is, the first focal point fy is retracted, that is, The state becomes closer to the vertical and passes through the second focal point f2, and this state is maintained and the main reflection surface 5 is reached.

  Therefore, since the incident angle and the reflection angle are equal during reflection, the traveling direction of the light after being reflected by the main reflection surface 5 is downward, which is suitable for passing beam distribution. Here, according to the present invention, both the fixed elliptical reflective surface 3a and the movable elliptical reflective surface 4a have substantially the same focal distance between the two focal points, so that the focal image generated on the main reflective surface 5 is reduced. The size is almost the same.

  Therefore, unlike the conventional variable orientation type headlight, there is no extreme difference in brightness even when the light distribution for passing beam and the light distribution for traveling beam are used. Further, when the traveling beam light distribution is made by changing the positions of the first focal points fx and fy between the fixed elliptical reflective surface 3a and the movable elliptical reflective surface 4a, the light beam hardly includes downward light. When beam distribution is used, almost all of the light is directed downward, and with the passing beam distribution turned on as in the conventional example, the traveling beam distribution was turned on to obtain the traveling beam distribution. Compared to the vehicle, the switching feeling between passing / running is excellent.

  Further, as shown in FIGS. 3 and 4, when the movable hood 4 is driven in the upward direction of the light source 2, the light source is within the range where the light is reached by the movable hood 4 as in the conventional example. A low beam reflecting surface 6 having a parabolic system having a focal point in the rear is arranged, and further, above the passing beam exclusive reflecting surface 6, light is transmitted when the movable hood 4 is housed in the fixed hood 3. It is also possible to provide a traveling beam dedicated reflecting surface 7 which is a parabolic system having a focal point at the center of the light source 2a (see also FIG. 4), and the light distribution pattern at this time is shown in FIG. As shown in FIG. The light distribution shape shown in FIG. 5 corresponds to the lamp shown in FIG. 3, and the light distribution shape shown in FIG. 6 corresponds to the lamp shown in FIG.

  However, in the configuration shown in FIG. 3, even when the movable hood 4 is moved, a portion of the passing beam light distribution remains because the light beam continues to hit the reflecting surface 6 for the passing beam, so that the driver feels switching. Although there is a possibility of damage, the luminous flux utilization rate with respect to the light source is the best.

It is explanatory drawing which shows the variable light distribution type headlight which concerns on this invention in the state of traveling beam light distribution. Similarly, it is explanatory drawing which shows the variable light distribution type headlight which concerns on this invention in the state of passing beam light distribution. Similarly, the variable light distribution type headlight according to the present invention is an explanatory diagram showing an example of an optical path when a mirror for exclusive use of passing light distribution and traveling light distribution is provided in the same manner as in the conventional example and a traveling beam light distribution state is set. . Similarly, the variable light distribution type headlight according to the present invention is provided with a reflective mirror for exclusive use of passing light distribution and traveling light distribution as in the conventional example, and an explanatory diagram showing an example of an optical path when the traveling beam light distribution state is set. It is. It is explanatory drawing which shows the light distribution characteristic of the variable light distribution type headlight shown in FIG. It is explanatory drawing which shows the light distribution characteristic of the variable light distribution type headlight shown in FIG. It is explanatory drawing which shows the structure of the variable light distribution type headlight of a prior art example in the state of passing light distribution. It is explanatory drawing which shows the shape of the traveling beam light distribution of the variable light distribution type headlight of a prior art example. It is explanatory drawing which shows the shape of the passing beam light distribution of the variable light distribution type headlight of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Variable light distribution type headlight 2 ... Light source 2a ... Light emission source 3 ... Fixed hood 3a ... Fixed ellipsoidal reflective surface 4 ... Movable hood 4a ... Movable elliptical reflective surface 5 ... Main reflective surface 6 ... Reflective surface for exclusive use of a passing beam 7 ... Traffic beam dedicated reflective surface

Claims (2)

The movable light shielding plate that changes the state of the light from the light source to the fixed hood reaches reflection mirror provided, running a passing beam light distribution by a change in state of the light from the light source reaching the reflecting mirror by the movable shielding plate in the variable light distribution type headlamps comprising switching between beam light distribution, the said fixed hood, which fixed elliptic reflecting surface to the lower direction of the light source and the second focal point and the light emission source and the first focal point, the movable the light shielding plate is provided with a movable elliptic reflecting surface to the light-emitting source after section first focus and to the fixed elliptic reflecting surface and substantially the same position of the second focal point, said second focal point below the light source variable light distribution-type headlight main reflection surface that is a parabolic to a substantially horizontal irradiation direction and focus, characterized in Tei Rukoto provided.   Above the reflecting mirror, when the movable elliptical reflecting surface is not driven, light from the light source reaches and reflects light in a substantially horizontal direction, and when driven, the light from the light source is blocked. 2. The variable light distribution type headlight according to claim 1, further comprising a traveling beam reflecting surface which is a parabolic reflecting surface.

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