JPH04223001A - compound reflector - Google Patents

Abstract

PURPOSE:To cope with problems which do not meet specifications because of lack of illuminance when a composite ellipsoid reflecting surface is employed in order that wide light distribution characteristics are secured in a projector type head-light for a vehicle. CONSTITUTION:When a composite reflecting mirror 1 is constituted to combine a spheroid reflecting surface 2 with a composite ellipsoid reflecting surface 6, the light distribution characteristics in a spot shape of the spheroid reflecting surface 2 are over-lapped with the light distribution characteristics which are wide in the horizontal direction, of the composite ellipsoid reflecting surface 6, so that ideal light distribution characteristics wide in width and high in center illuminance, can thereby be provided. The combination of the aforesaid two surfaces formed into the composite reflecting mirror 1 enables the universality in shape of the light distribution characteristics such as use for keeping traffic to the left to be provided with no reduction in center illuminance with a photo axis Z6 tilted at the side of the composite ellipsoid reflecting surface 1.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a headlamp called a projector headlamp, and more particularly to a reflector thereof.

0002

2. Description of the Related Art FIGS. 6 and 7 show examples of conventional reflecting mirrors 91 of this type, which typically have light distribution characteristics that are narrow in the vertical direction and wide in the horizontal direction as headlamps for automobiles. Therefore, the light source 92 has a first focal point F1, and as shown in FIG.
3, the second focal point F2V is located approximately at the position of the focal point F0, and as shown in FIG.
Composite ellipsoidal reflection with 2H was to be adopted.

0003

[Problems to be Solved by the Invention] However, in the above-mentioned conventional reflecting mirror 91 having a compound ellipsoidal reflecting surface, if the above-mentioned horizontal light distribution width is made sufficient, the center illuminance is insufficient, and the center illuminance is If the above conditions are satisfied, the light distribution width in the horizontal direction becomes insufficient, resulting in the problem that a headlamp that satisfies both conditions cannot be obtained, and a solution to this problem has been proposed.

0004

[Means for Solving the Problems] The present invention provides a composite reflecting mirror in which a plurality of ellipsoidal reflecting surfaces are combined, as a specific means for solving the conventional problems described above. a spheroidal reflecting surface having a second focal point at approximately the focal point of the projection lens; and a first focal point at the position of the light source, which is near the focal point of the projection lens in a vertical section and ahead of it in a horizontal section. By providing a composite reflecting mirror characterized by combining a composite ellipsoidal reflecting surface having a second focal point with a composite ellipsoidal reflecting surface having a second focal point, sufficient light distribution characteristics and center illuminance can be obtained. This is a solution to a conventional problem.

[0005]

[Embodiment] Next, the present invention will be explained in detail based on an embodiment shown in the drawings. FIG. 1 shows a composite reflecting mirror 1 according to the present invention in a vertical cross section, and this composite reflecting mirror 1 has a combination of a spheroidal reflecting surface 2 and a compound ellipsoidal reflecting surface 3, and the spheroidal reflecting surface 2 has a first focus F21 at the position of the light source 4, and a second focus F22 substantially coincident with the focus F of the projection lens 5.

One of the compound ellipsoidal reflecting surfaces 3 has a first focal point F3.
1 is set at the position of the light source 4 like the spheroidal reflecting surface 2, but the vertical second focal point F32 of this composite ellipsoidal reflecting surface 3 is projected in the vertical cross section of FIG. It is set at the position of the focal point F of the lens 5, or slightly closer to the front.

FIG. 2 shows a horizontal cross section of the compound reflecting mirror 1, and in this horizontal cross section, the spheroidal reflecting surface 2 naturally aligns the first focal point F21 with the position of the light source 4, and the second focal point F21 coincides with the position of the light source 4. The focal point F22 is made to substantially coincide with the position of the focal point F of the projection lens 5, and the compound ellipsoidal reflecting surface 3 makes the first focal point F31 coincide with the position of the light source 4, but the horizontal The side second focus F33 is set in front of the vertical side second focus F32, that is, on the irradiation direction side.

[0008] Here, to explain the compound ellipsoidal reflecting surface 3, this compound ellipsoidal reflecting surface 3 has a first focal point F31 in a section at an intermediate angle from the vertical section in FIG. 1 to the horizontal section in FIG. is fixed at the position of the light source 4, and an ellipse appears that temporarily approaches the second focal point from the vertical second focal point F32 toward the horizontal second focal point F33, that is, has a common first focal point F31. and change the second focus from F32 to F33.
It becomes a composite of countless ellipses.

Furthermore, when joining the spheroidal reflecting surface 2 and the compound ellipsoidal reflecting surface 3, the spheroidal reflecting surface 2
If they are joined at the intersection P so as to be disposed on the light source side, there will be no difference in level between the reflecting surfaces 2 and 3, and a composite reflecting mirror 1 that will not generate stray light, for example, will be obtained.

Next, the effects of the composite reflecting mirror 1 having the above structure will be explained. FIG. 3 shows the composite reflecting mirror 1
The light distribution characteristic H2 due to the spheroidal reflecting surface 2 is a spheroidal ellipsoid, and the second focal point F22 substantially coincides with the position of the focal point F of the projection lens 5.
By having this, it converges in a spot shape at the center.

On the other hand, the light distribution characteristic H2 due to the composite ellipsoidal reflecting surface 3 has a vertical second focal point F32 near the focal point F of the projection lens 5 in the vertical cross section, and a horizontal second focal point F32 in the vicinity of the focal point F of the projection lens 5 in the horizontal cross section. By having the side second focal point F33, it is possible to obtain a lens that is narrow in the vertical direction and wide in the horizontal direction.

That is, in the composite reflecting mirror 1 of the present invention, by adjusting the area ratio of the spheroidal reflecting surface 2 and the composite ellipsoidal reflecting surface 3 or the shape of the compound ellipsoidal reflecting surface 3, the central illuminance can be adjusted. Also, the shape of the light distribution characteristic H can be freely adjusted. Although not shown in the drawings, it goes without saying that in actual implementation of the present invention, a light shielding plate for correcting the shape of the light distribution characteristic H is additionally employed.

FIG. 4 is a horizontal cross section showing another embodiment of the present invention, in which the previous embodiment had the spheroidal reflecting surface 2 and the composite ellipsoidal reflecting surface 3 arranged on the same optical axis. On the other hand, in this embodiment, the optical axis Z6 of the composite ellipsoidal reflecting surface 6 is aligned with the first focal point F21, respectively, with respect to the optical axis Z2 of the spheroidal reflecting surface 2.
It is tilted so that it intersects at F61.

Therefore, the horizontal second focal point F63 of the compound elliptical reflecting surface 6 naturally occurs on the optical axis Z6, that is, at a position biased to the left side compared to the previous embodiment.

The direction in which the optical axis Z6 is tilted may be tilted to the left if the composite reflector 1 is used, for example, for driving on the left. As shown in 5, the light distribution characteristic H2 from the spheroidal reflecting surface 2 facing the front of the vehicle and the light distribution characteristic H6 from the compound ellipsoidal reflecting mirror 6 which is wider toward the left side are combined to illuminate the roadside. In addition, light distribution characteristics suitable for driving on the left without dazzling oncoming vehicles can be obtained.

In this embodiment, the optical axis Z6 is tilted horizontally, but it may also be tilted vertically, for example, downward, or it can be tilted vertically and horizontally. It may also be tilted in two directions. Further, since the functions and effects other than those described above are the same as those of the previous embodiment, detailed explanations will be omitted here.

[0017]

As explained above, the present invention provides a spheroidal reflecting surface having a first focal point approximately at the position of the light source and a second focal point approximately at the position of the focal point of the projection lens; A compound reflecting mirror is formed by combining a compound ellipsoidal reflecting surface which has a first focal point near the focal point of the projection lens in the vertical section and a second focal point in front of it in the horizontal section. The ellipsoidal reflective surface is used to converge the light distribution characteristics to the center to obtain central illuminance, and the compound ellipsoidal reflective surface allows the light distribution width in the horizontal direction to be freely set, so that the central illuminance is also insufficient. This has the extremely excellent effect of making it possible to provide a projector headlamp that can provide a satisfactory light distribution width without requiring a large amount of light.

Furthermore, by tilting the optical axes of the spheroidal reflecting surface and the composite ellipsoidal reflecting surface so that they intersect at their respective first focal points, the shape of their light distribution characteristics can be formed more freely. As a result, it also has an excellent effect of improving performance.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view showing an embodiment of a composite reflecting mirror according to the present invention.

FIG. 2 is a horizontal cross-sectional view of the same embodiment.

FIG. 3 is an explanatory diagram showing the operation of the same embodiment.

FIG. 4 is a horizontal sectional view showing another embodiment according to the present invention.

FIG. 5 is an explanatory diagram showing the operation of another embodiment.

FIG. 6 is a vertical sectional view showing a conventional example.

FIG. 7 is a horizontal sectional view of the same conventional example.

[Explanation of symbols]

1...Compound reflecting mirror 2...Spheroidal reflecting surface 3, 6...Compound ellipsoidal reflecting surface 4...Light source 5...Projection lens F...Focal point F21 of the projection lens...No. of the spheroidal reflecting surface One focal point F22...Second focal point of the spheroidal reflecting surface F31, F61...First focal point of the compound ellipsoidal reflecting surface F32...Second focus on the vertical side of the compound ellipsoidal reflecting surface F33, F63...Compound ellipsoidal surface Second focal point on the horizontal side of the reflective surface Z2...Optical axis Z6 of the spheroidal reflective surface...Optical axis of the composite ellipsoidal reflective surface

Claims (2)

[Claims] 1. A compound reflecting mirror in which a plurality of ellipsoidal reflecting mirrors are combined, comprising: a spheroidal reflecting surface having a first focal point approximately at the position of the light source and a second focal point approximately at the position of the focal point of the projection lens; , a compound ellipsoidal reflecting surface having a first focal point at the position of the light source and a second focal point near the focal point of the projection lens in a vertical section and in front of it in a horizontal section. Composite reflector. 2. The optical axis of the compound ellipsoidal reflecting surface is inclined to intersect with the optical axis of the spheroidal reflecting surface at the position of each first focal point.
Composite reflector as described.