JP2008177037A - Headlamp for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To supplement brightness of a vehicle lamp by making reflection light of the light from a light source, reflected on a hood, go downward in irradiation direction. <P>SOLUTION: The vehicle lamp has concave spherical faces 11-13 which are treated in mirror face and have their focus at the light source formed at a portion of a hood 10 on which the light from the light source 3 is lighted. Then, the center line FX of the concave spherical face is set at 0.5-5 mm upper part than the center line X of the light source, thereby, a virtual image is formed at the upper part of the light source, and the downward light reflecting to the reflecting face from the virtual image is added to the light distribution characteristics, thereby bright light having no dazzlement is obtained. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  In the present invention, the reflecting surface is formed as a paraboloidal system and the irradiation direction is relatively wide, so that direct light from a light source such as a filament reaches a driver of an oncoming vehicle and causes dazzling. Since the possibility becomes high, the present invention relates to a configuration of a vehicle headlamp in which a hood formed of an opaque member such as metal is attached in front of the light emitting source.

  At this time, when the light is simply shielded by the hood, almost all of the light from the shielded light source becomes invalid and cannot be used as irradiation light. Since the utilization efficiency is lowered, it is possible to increase the utilization efficiency with respect to the light source and realize a brighter vehicle lamp by assuming that a part of the light shielded by the hood can be used as the irradiation light.

  FIG. 8 shows an example of a configuration for obtaining a bright vehicular lamp 90 by effectively using the amount of light from one light emitting source of this type in the past. First, the vehicular lamp 90 of this conventional example includes a light source 91, a first reflecting surface 92 having the light source 91 as a focal point, a second reflecting surface 93 that reflects light from the light source 91 in the same manner as the first reflecting surface 92, and the light from the light source 91 once. The third reflection surface 94 that reflects obliquely upward and the fourth reflection surface 95 that reflects the light from the third reflection surface 94 in the irradiation direction and serves as irradiation light is configured. Yes.

With this configuration, the light source 91 and the first reflecting surface 92 that reflects the light from the light source 91 can obtain light distribution characteristics having substantially the same amount of light and the same shape as those of conventional vehicle lamps. In addition, in addition to this, the light quantity captured by the second reflecting surface 93 and the fourth reflecting surface 95 is reinforced to realize a brighter vehicle lamp.
Japanese Patent Laid-Open No. 2002-25312

  However, in the above-described conventional vehicular lamp 90, the light distribution characteristic is formed with a simple shape of only the light source 91 and the first reflecting surface 92, whereas the second reflecting surface 93 and the third reflecting surface 94 are formed. Furthermore, a fourth reflecting surface 95 and three reflecting surfaces are added. In particular, the light reflected by the third reflecting surface 94 is reflected again by the fourth reflecting surface 95 to form a light distribution characteristic. Since it bears a part, considerable accuracy is required, and there is a problem of cost increase due to complicated configuration.

The present invention provides, as specific means for solving the above-described conventional problems, a light emitting source, a parabolic main reflecting surface that has the light emitting source as a focal point and is disposed behind the light emitting source in the irradiation direction. A vehicular headlamp centered above the light emitting source and disposed in front of the light emitting source in the irradiation direction, wherein the concave spherical reflecting surface is the light emitting source. A first reflecting portion provided at a position intersecting the optical axis in front of the irradiation direction, and a second reflecting portion provided around the optical axis, wherein the first reflecting portion and the first reflecting portion The light from the light source reflected by the second reflecting portion is focused near the light source to form a virtual light source, and the parabolic main reflection surface includes the light from the light source and the light source. Irradiating light from the virtual light source with the light from the vehicle lamp,
A vehicular headlamp characterized by that. The center of the concave spherical reflecting surface is located 0.5 mm to 5 mm above the light source, and the object is solved by providing a vehicular headlamp. .

  According to the present invention, as the distance from the light source increases in the irradiation direction, the plurality of concave spherical surface portions having a larger radius and the ring portion that reduces the amount of light reflected from the light source substantially parallel to the light emitted from the light source. The hood is formed by connecting a plurality of the hoods and the inner surface is mirror-finished, and the center line in the irradiation direction of the hood is installed 0.5 mm to 5 mm above the center line in the irradiation direction of the light source. Assuming that the reflected light of the light from the light source reflected by the hood is directed downward in the irradiation direction, the brightness of the vehicular lamp is supplemented to achieve the purpose.

  Below, this invention is demonstrated in detail based on embodiment shown in a figure. 1 and 2 schematically show a state in which a hood 10 of a vehicular lamp according to the present invention is attached to a vehicular headlamp 1. The vehicular headlamp 1 is, for example, a paraboloid of revolution. A reflection surface 2 formed as a light source, a light emitting source 3 such as a filament disposed near the focal point of the reflection surface 2, a side wall 2a surrounding the reflection surface 2, and a front side of the side wall 2a. And an outer lens 4 to be formed.

  In order to simplify the description, the light emitting source 3 is described as emitting light from one point corresponding to the focal point, and the hood 10 transmits light from the light emitting source 3 to the reflecting surface 2. The following description will be made on the assumption that the light emission from the light emitting source 3 is limited within the range where the light emission exists.

  Incidentally, in a vehicle headlamp 1 such as a headlight in recent years, the outer lens 4 is made transparent, and the light distribution characteristic of the vehicle headlamp 1 is perpendicular to the reflecting surface 2 as shown in FIG. A parabola appears on the cross-section side and reflects light from the light source in a state close to a parallel line extending in a substantially horizontal direction, and a plurality of straight lines appear on the cross-section on the horizontal side as shown in FIG. A combination of so-called parabolic column surfaces reflecting in a wide range in the left-right direction is used. In this case, the hood 10 is only in the range of the reflecting surface 2. The shape is adjusted so as to give light.

  FIG. 3 shows a state when light is applied to the hood 10 whose tip is formed by the concave spherical surface 11, and the state shown in the figure emits light at the center Q of the concave spherical surface where the hood 10 is formed. The state when the light is emitted with the sources 3 matched is shown. Here, the shape of the light emitting source 3 is shown as a point light source.

  At this time, the light emitted from the light emitting source 3 is reflected by a surface perpendicular to the light traveling direction on the inner surface of the hood 10, so the reflected light (shown by a broken line) inevitably reaches the light emitting source 3. The reflected light is reflected in the returning direction, and the light reflected from the light source 3 is overlapped with the reflected light to form a focal image on the center Q, that is, at a position coincident with the light source 3.

  In FIG. 4, the light emitting source 3 is disposed on the concave spherical surface 11 of the same hood 10 at a position (0.5 mm to 5 mm) appropriately below in the vertical direction from the center of the concave spherical surface on which the hood 10 is formed. This shows the state when the light from the light emitting source 3 is reflected, and the light reflected by the hood 10 forms a focal point QF at a position above the light emitting source 3.

  In the present invention, the inner surface of the hood 10 is mirror-finished 10a, and as shown in FIG. 4, it is reflected and converged by the inner surface of the hood 10, and the second light emitting source 3F is In the present invention, it is assumed that light from the second light emitting source 3F (virtual image) also reaches the reflecting surface 2 and is reflected in the irradiation direction of the irradiation lamp 1.

  That is, in the vehicle headlamp 1 according to the present invention, the light directly emitted from the light source 3 and the light reflected from the hood 10 are reflected on the reflecting surface 2 and once converged to an appropriate position above the light source 3. After that, the light is again diffused and comes into contact with the light directed toward the reflecting surface 2. At this time, the hood 10 has an appropriate shape such as a concave spherical surface as described above, and is attached. The position is also devised, and the second light emission source 3F (virtual image) is formed substantially vertically above the actual light emission source 3 and upward.

  And the light from the said light emission source 3 and the 2nd light emission source 3F is reflected by the reflective surface 2, as mentioned above, and is turned up in the irradiation direction, and becomes irradiation light of the vehicle headlamp 1. Therefore, in the case of the vehicle headlamp 1 having a normal configuration, the hood 10 is exclusively used to shield direct light from the light source 3 radiated in the irradiation direction. In the present invention, the hood 10 is formed so that the light abutting on the hood 10 can be reused as irradiation light, so that the luminous flux utilization rate with respect to the light source 3 as the vehicle headlamp 1 is higher. Thus, a bright vehicle headlamp 1 is obtained.

  In terms of light distribution, the light emitting source 3 is provided on the center line X of the reflecting surface 2 and reflected in the irradiation direction as shown in FIG. However, as shown by the solid line M in FIG. 5, the second light emission is effective for forming a so-called traveling light distribution that illuminates a distant area in front of the vehicle. Since the reflected light from the source 3F is generated above the focal point of the reflecting surface 2, it is appropriately downward as shown by the chain line S in FIG. 5, and the oncoming vehicle also has a light distribution characteristic in which the light from both sides is synthesized. There is no dazzling.

  FIG. 6 shows the shape and configuration of the hood 10 according to the present invention in detail. The hood 10 is formed with reference to a center line XF and a reference point PF set on the center line XF. . When the center line X of the reflecting surface 2 and the center line XF of the hood 10 are overlapped, the position of the focal point of the reflecting surface and the reference point PF are overlapped.

  And since the hood 10 is preferably in a cylindrical shape or the like so as not to block a large amount of light reflected by the reflecting surface 2 and traveling in the irradiation direction, it is not the hemispherical shape described above in the present invention. As a shape in which a plurality of concave spherical surfaces having different radii are arranged in the irradiation direction, the amount of irradiation light shielded is reduced.

  FIG. 6 shows an example in which the hood 10 is formed of, for example, three sets of concave spherical surfaces, a first concave spherical surface 11, a second concave spherical surface 12, and a third concave spherical surface 13. One concave spherical surface 11 is provided, and the radius of the first concave spherical surface is a distance to the reference point PF. A second concave spherical surface 12 is installed behind the first concave spherical surface 11, that is, on the reference point PF side.

  At this time, the outer diameter of the second concave spherical surface 12 is the same as the outer diameter of the first concave spherical surface 11, but the radius forming the second concave spherical surface 12 is also the distance to the reference point PF. Yes. This means that the first concave spherical surface 11 is farther from the reference point PF than the second concave spherical surface 12, so that the light is incident on the entire surface of the first concave spherical surface 11 at a narrow angle from the reference point PF. The second concave spherical surface 12 is provided with a necessary and sufficient opening 12a for the purpose.

  Further, a third concave spherical surface 13 is provided closer to the reference point PF than the second concave spherical surface 12, and the radius of the third concave spherical surface 13 is also a distance from the reference point PF. The second concave spherical surface 12 is also provided with an opening 13 a for supplying light to the second concave spherical surface 12.

  In the first concave spherical surface 11, the second concave spherical surface 12, and the third concave spherical surface 13 formed as described above, a cylindrical holder portion 11b matched to the outer diameter of these concave spherical surfaces 11 to 13, 12b and 13b are provided, and each can be fitted at a predetermined position. Therefore, if the parts are attached and assembled by bonding, welding or the like after fitting, the desired hood 10 can be formed. Note that, as described above, the mirror surface processing 10 a is performed in advance on the concave surface portions of the first concave spherical surface 11, the second concave spherical surface 12, and the third concave spherical surface 13.

  Further, when the hood 10 formed as described above is attached to the reflecting surface 2, the hood 10 is provided with a stay or the like so that the light emission source 3 is disposed at a position assumed below the reference point PF. Appropriate means are provided and attached to the reflecting surface 2 (see FIG. 1).

  Further, as shown in FIG. 7, the hood 10 of the present invention has a first concave spherical surface 11 and a second concave spherical surface 12 between the first concave spherical surface 11 to the third concave spherical surface 13 formed in the same manner as described above. The gap is a conical shape with the reference surface PF as the apex and the diameter of the first concave spherical surface 11 as the bottom surface, that is, a conical shape with an angle of light that comes into contact with the first concave spherical surface 11 from the light source 3 and is reflected and turned back. And is cut at a position corresponding to the opening 12a provided in the second concave spherical surface 12 to form a ring portion 11d and connected by an appropriate means such as welding. You may connect with the 3rd concave spherical surface 13 by the ring part 12d.

  In this case, the outer diameter of each of the first concave spherical surface 11 to the third concave spherical surface 13 is not restricted by the diameters of the holders 11b, 12b and the like as in the previous embodiment. The degree of distribution of the downward light distribution formed by the second light emitting source 3F is also given a degree of freedom.

  Finally, according to the results of trial manufacture and experiment of the vehicular lamp of the present invention by the inventor, the distance between the center line X of the reflecting surface 2 and the center line FX of the hood 10 according to the present invention is the center line FX of the hood 10. Is set at 0.5 mm to 5 mm above the center line X of the reflecting surface 2, it has been clarified that good results can be obtained in both light distribution characteristics and brightness enhancement.

It is explanatory drawing which shows schematically the state attached to the vehicle lamp of the hood which concerns on this invention in the state cut in the vertical direction. Similarly, it is explanatory drawing which shows schematically the cross section to the horizontal direction of the state which attached the hood which concerns on this invention to the vehicle lamp. It is explanatory drawing which shows a state when light is given to the concave spherical surface from the center of the concave spherical surface. It is explanatory drawing which shows the operation | movement principle of the hood of the vehicle lamp which concerns on this invention. It is explanatory drawing which shows the example of the light distribution characteristic obtained with the food | hood of the vehicle lamp which concerns on this invention. It is sectional drawing which shows 1st embodiment of the food | hood of the vehicle lamp which concerns on this invention. It is sectional drawing which shows 2nd embodiment of the food | hood of the vehicle lamp which concerns on this invention. It is explanatory drawing which shows a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Vehicle lamp 2 ... Reflective surface 3 ... Light source 4 ... Outer lens 10 ... Hood 10a ... Mirror surface treatment 11 ... First concave spherical surface 12 ... Second concave spherical surface 13 ... Third concave spherical surface 14 ... Holder

Claims (4)

A light source;
A parabolic main reflecting surface that is focused on the light emitting source and is arranged behind the light emitting source in the irradiation direction;
A vehicular headlamp comprising a concave spherical reflecting surface centered on the light source and disposed in front of the light source in the irradiation direction,
The concave spherical reflecting surface is composed of a first reflecting portion provided at a position intersecting with the optical axis in front of the light emitting source in the irradiation direction, and a second reflecting portion provided around the optical axis. ,
The light of the light emitting source reflected by the first reflecting portion and the second reflecting portion is focused near the light emitting source to form a virtual light source,
The paraboloidal main reflection surface irradiates light from the light source, light from the light source, and light from the virtual light source in the irradiation direction of the vehicular lamp.
A vehicular headlamp characterized by that.   The vehicle headlamp according to claim 1, wherein the center of the concave spherical reflecting surface is located 0.5 mm to 5 mm above the light source.   The vehicular headlamp according to claim 1, wherein the concave spherical reflecting surface is formed on an inner surface of a hood covering the front of the light emitting source.   The vehicular headlamp according to any one of claims 1 to 3, wherein the first reflecting portion and the second reflecting portion are connected by a connecting portion to form the hood.

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