JP5325501B2 - Vehicle lighting - Google Patents

Description

  According to the present invention, when a light distribution pattern for passing beam is formed, the light distribution pattern for overhead sign is formed at the light / dark boundary portion of the light distribution pattern for passing beam in order to ensure the visibility of the overhead sign (overhead sign). The present invention relates to a projector-type vehicular lamp.

  2. Description of the Related Art In recent years, projector-type lamps that employ a projection lens and can be miniaturized are widely used as vehicle headlamps. As shown in FIG. 11, such a projector-type vehicular lamp 100 includes a light source 101 provided on an optical axis X in the vehicle front-rear direction and light emitted from the light source 101 toward the front, closer to the optical axis. And a projection lens 103 attached to the front end opening of the lens holder 105 on the front side of the reflector 102.

  Furthermore, in order to generate a passing beam light distribution pattern in the vehicular lamp 100, the reflected light RB from the reflector 102 is interposed between the reflector 102 and the projection lens 103 as shown in FIG. A light shielding plate 104 that shields a part and removes upward irradiation light is provided. As a result, as shown in FIG. 12, the upper side becomes the light / dark boundary DL, and the light distribution pattern P1 for the passing beam with the additional light distribution pattern P1a is formed on the side portion.

  However, in such a projector-type lamp, since the upward irradiation light is almost removed by the light-shielding plate 104, the overhead sign placed above the road ahead of the vehicle is not sufficiently irradiated, and this is visually recognized. It will deteriorate the nature. Therefore, in the vehicular lamp 100 of FIG. 11, an inclined surface 104a extending obliquely downward toward the front is formed on the upper part of the light shielding plate 104, and the reflected light RB from the reflector 102 is deflected upward on the inclined surface 104a. An upward overhead sign irradiation pattern P <b> 2 is formed by reflecting the projection lens 103.

However, the illuminance and pattern shape of the light distribution pattern P1 for the passing beam and the light distribution pattern P2 for the overhead sign formed in this way must conform to a predetermined standard. In particular, since the overhead sign light distribution pattern P2 is irradiated upward in the forward direction of the vehicle, an upper limit of illuminance is set so as not to dazzle the driver of the oncoming vehicle. There has been proposed a technique in which a groove portion is formed on a reflection surface so as to obtain an overhead sign irradiation pattern with an appropriate amount of light (see Patent Document 1).
JP 2008-4456 A

  By the way, the overhead sign light distribution pattern P2 is a standard-standard required pattern as shown by the broken line in FIG. 13, and the upper limit of the illuminance is defined in the central portion P2a. However, it is extremely difficult to simultaneously match the pattern shape of the overhead sign light distribution pattern P2 and the illuminance of the designated central portion P2a with the standard.

  FIG. 12 schematically shows the pattern shape of the overhead sign light distribution pattern P2 formed by plane reflection in the above-described conventional vehicle lamp, and the region indicated by the broken line in FIG. 12 is reflected by the reflector. This is a part where it is difficult to control the light RB, and the loss of irradiation light occurs and does not approximate the required pattern. Further, accurate adjustment of the illuminance at the central portion P2a cannot be easily performed.

Therefore, the present invention solves the above problems by the means described below. That is, according to the first aspect of the present invention, the light source provided on the optical axis, the reflector that reflects the light from the light source toward the front optical axis, the reflected light of the reflector and the front of the vehicle are transmitted. In the vehicular lamp provided between the projection lens and the reflector, a front side of the light shielding plate, the projection lens for irradiating and a light shielding plate for shielding a part of the reflected light from the reflector and removing the upward irradiation light A prism lens that has been subjected to an optical path adjustment process of the reflected light is disposed on the top of the light source, and the prism lens is a reflection surface that totally reflects light incident from the incident surface facing the vicinity of the upper edge of the light shielding plate. A prism, and the prism lens has a triangular cross-section in the front-rear direction of the vehicle, which includes the incident surface, the reflective surface, and the exit surface. Yes, the pre Of the entrance surface or exit surface of the lens, the portion of the optical path toward the center of the overhead sign light distribution pattern is subjected to a textured process, and a part of the reflected light from the reflector is incident on the prism lens. The overhead sign light distribution pattern is formed at the light / dark boundary portion of the low beam light distribution pattern.

  According to the present invention, since it becomes easy to control the reflected light from the reflector, it is possible to form an overhead sign light distribution pattern of an arbitrary shape at the light / dark boundary portion of the low beam light distribution pattern, It is possible to accurately adjust the illuminance at the center of the overhead sign light distribution pattern.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a cross-sectional view of a vehicular lamp 1 according to the present invention. As shown in FIG. 1, main components are a light source 2, a reflector 3, a lens holder 4, and an opening at the front end of the lens holder 4. And a light shielding plate 6 that rises from the bottom of the lens holder 4. The reflector 3 and the lens holder 4 are formed in a cylindrical shape from a heat-resistant material, and the rear end opening of the lens holder 4 is fitted and integrated with the front end opening of the reflector 3.

  The light source 2 is a discharge bulb such as a halogen bulb or a metal halide, and is attached to the reflector 3 so as to be positioned on an optical axis X extending in the front-rear direction of the vehicle lamp 1 body. The reflector 3 is formed with an elliptical reflecting surface 3a centered on the optical axis X. Since the light source 2 is disposed at the first focal point F1 of the reflecting surface 3a, the light emitted from the light source 2 is The light is reflected toward the front optical axis X, and the reflected light RB is converged to the second focal point F2.

  The projection lens 5 is a plano-convex lens having a convex front surface and a flat rear surface, and is arranged so that the rear focal position coincides with the second focal point F <b> 2 of the reflector 3. Thereby, the projection lens 5 condenses and transmits the reflected light RB from the reflecting surface 3a of the reflector 3 near the optical axis X.

  The light shielding plate 6 is formed integrally with the lens holder 4 so as to block the lower half of the inner space of the lens holder 4, and removes the upward reflected light RB reflected from the reflecting surface 3a of the reflector 3. Thus, a light distribution pattern for a passing beam that is substantially parallel to the optical axis X is obtained.

  Next, in the vehicular lamp 1 of the present invention, the configuration of the formation elements of the overhead sign light distribution pattern P2 will be described. In the present invention, the prism lens 7 is used to determine the optical path of the reflected light RB from the reflector 3 toward the projection lens 5 and is erected on the front surface of the light shielding plate 6 as shown in FIG. Both sides of the prism lens 7 are fixedly supported on the support piece 6a.

  When the prism lens 7 is a triangular prism as shown in FIG. 3, the incident surface 7a faces the vicinity of the upper end edge of the light shielding plate 6 to form the overhead sign light distribution pattern P2 incident from the incident surface 7a. Therefore, the reflected light RB is totally reflected by the reflecting surface 7 b and emitted from the emitting surface 7 c toward the projection lens 5. Then, the light flux of the overhead sign light distribution pattern P2 is emitted from the projection lens 5 at an upward angle of approximately 0 ° to 6 °, for example, about 5 °, and irradiates an overhead sign in front of the vehicle.

  In the case of using the prism lens 7, the incident light beam is totally reflected and emitted, but the prism lens 8 having the shape shown in FIG. 4 can also be adopted, and the vehicular lamp 1 shown in FIG. Can be configured. In this case, the incident surface 8a faces the vicinity of the upper edge of the light shielding plate 6, the reflected light RB that forms the overhead sign light distribution pattern P2 incident from the incident surface 8a is refracted inside, and the light exits from the output surface 8b. The light is emitted toward the projection lens 5.

  The prism lenses 7 and 8 are preferably formed of a high heat-resistant glass material or the like, and can be molded, so that the entrance surfaces 7a and 8a and the exit surface 7c, which are generally flat surfaces, are used. In the case of the lens 8b or the prism lens 7, the reflecting surface 7b can have an arbitrary surface shape. Therefore, the direction of the incident reflected light beam RB is controlled by the surface shape, and the direction of the optical path can be partially changed. Therefore, the overhead sign light distribution pattern P2 is changed to a desired pattern. It can be a shape.

  6 to 8 show the result of the light distribution pattern in the verification experiment of the vehicular lamp 1 of the present invention configured as described above. FIG. 6 shows the incident surface 7a, the reflecting surface 7b of the prism lens 7, and FIG. Each of the emission surfaces 7c is a flat surface. In this case, the pattern shape of the overhead sign light distribution pattern P2 results in a loss from the center to the left and right as in the case where a conventional reflector is employed, and the brightness of the center portion P2a increases.

  FIG. 7 shows the result of the light distribution pattern that has undergone the optical path adjustment processing. As shown in FIG. An emission surface 7d having a different inclination angle from the surface 7c was formed. By forming the prism lens 7 in this way, the reflected light RB is controlled by the emission surface 7d, and light distribution is also formed from the center to the side. In addition, in this optical path adjustment process, in the case of the entrance surfaces 7a and 8a and exit surfaces 7c and 8b of the prism lenses 7 and 8, or in the case of the prism lens 7, a curved surface may be formed in the main part of the reflection surface 7b. FIG. 8 shows the result of a light distribution pattern obtained by performing optical path adjustment processing at two places on the entrance surface 7a and the exit surface 7c of the prism lens 7, and a more ideal overhead sign light distribution pattern P2 can be formed. did it.

  Next, since the standard reference luminance is determined at the central portion P2a of the overhead sign light distribution pattern P2 as described above, a light reduction process is applied to this portion. FIG. 10 shows the prism lens 8 in which a portion of the optical path toward the center portion P2a of the overhead sign light distribution pattern P2 is subjected to the texture processing 8c. It was possible to confirm the attenuation of. In addition, the said dimming process can obtain the same result also by the method of sticking a filter sheet irrespective of a texturing process.

  As described above in detail, according to the present invention, it is possible to control the reflected light with high accuracy by adopting the prism lens to determine the optical path of the reflected light from the reflector toward the projection lens. . And since prism lenses can be molded, any shape can be formed uniformly, and dimming can be done easily, so that the quality of the vehicle conforms to the standard. An effect peculiar to the present invention can be achieved, such as providing a lamp.

It is sectional drawing of the vehicle lamp of this invention. It is a perspective view which shows the structure of the principal part of the vehicle lamp of FIG. It is a figure explaining the formation state of the optical path of the reflected light by a prism lens. It is a figure explaining the formation state of the optical path of the reflected light by a prism lens. It is sectional drawing which shows the other example of the vehicle lamp of this invention. It is a figure explaining the light distribution pattern for overhead signs. It is a figure explaining the light distribution pattern for overhead signs. It is a figure explaining the light distribution pattern for overhead signs. It is a perspective view which shows the example of the prism lens which performed the optical path adjustment process. It is a perspective view of the example which performed the light reduction process to the prism lens. It is sectional drawing of the conventional vehicle lamp. It is a figure explaining the conventional light distribution pattern for overhead signs. It is a figure explaining the standard reference | standard of the light distribution pattern for overhead signs.

Explanation of symbols

1 .... Vehicle lamp 2 .... Light source 3 .... Reflector 4 .... Lens holder 5 .... Projection lens 6 ....・ Light shielding plate 7 ・ ・ ・ ・ ・ ・ Prism lens 8 ・ ・ ・ ・ ・ ・ ・ ・ Prism lens P1 ・ ・ ・ Light distribution pattern for passing beam P2 ・ ・ ・ Light distribution pattern for overhead sign RB ・ ・ ・ ・·reflected light

Claims (1)

A light source provided on the optical axis; a reflector that reflects light from the light source toward the front optical axis; a projection lens that transmits the reflected light of the reflector and irradiates the front of the vehicle; and In the vehicular lamp provided with a light-shielding plate that shields part of the reflected light and removes the upward irradiation light between the projection lens and the reflector,
A prism lens that has been subjected to an optical path adjustment process of the reflected light is disposed on the front side of the light shielding plate,
The prism lens includes an incident surface facing the vicinity of the upper edge of the light shielding plate, a reflecting surface that totally reflects light incident from the incident surface, and an emitting surface that emits light totally reflected by the reflecting surface,
Further, the prism lens has a triangular cross-section in the front-rear direction of the vehicle composed of the entrance surface, the reflection surface, and the exit surface.
Of the incident surface or the exit surface of the prism lens, the portion of the optical path toward the center portion of the overhead sign light distribution pattern is subjected to a graining process,
The overhead sign light distribution pattern is formed at the light / dark boundary portion of the low beam light distribution pattern by causing a part of the reflected light from the reflector to enter the prism lens. Light fixture.

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