JPH06314503A - Projector-type head lamp - Google Patents

Abstract

PURPOSE:To lower the electric power consumption of a light source and make a heat resistant structure or a heat radiating structure unnecessary by installing a shielding plate whose lower face is made to be a reflecting face between secondary focusing projection lens of an elliptic face reflecting mirror as a horizontal plate. CONSTITUTION:A shielding plate 4 is a horizontal plate and installed slightly above a center line Z or at a position where it touches the line Z. The lower face of the shielding plate 4 is made to be a mirror face 4a and the upper face is made to be non-reflecting face 4b. The reflected light from the upper half part 3a of an elliptic face reflecting mirror 3 having a first focusing point F1 is focused on a second focusing point F2 and then reflected totally by the mirror face 4a of the shielding plate 4 and reaches the lens 5 after it changes proceeding direction downward. Consequently, the reflected light from the upper half part 3a and the lower half part 3b is projected to the lens as the same state. As a result, the whole quantity of the light of the light source 2 can be utilized and thus electric power consumption is lowered.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicular lamp, and more particularly to a structure of a headlight called a projector type headlamp.

[0002]

2. Description of the Related Art A conventional projector type headlamp 90
FIG. 5 shows an example of the configuration of the elliptical reflecting mirror 91.
Of the light source 92 arranged at the first focal point F1 of the shielding plate 93 so as to be substantially orthogonal to the light flux that converges at the second focal point F2.
The shielding plate 93 shields a portion that becomes upward light when projected forward by the projection lens 94, and obtains light distribution for a low beam or for a fog lamp.

[0003]

However, in the above-mentioned conventional projector type headlamp 90,
As described above, almost all of the upward light in the light flux that converges on the second focus F2 is shielded. Therefore, the amount of shielding the light flux is approximately half of the light reflected from the elliptical reflection surface 91. The luminous efficiency of the luminous flux is reduced, and a bright light cannot be obtained for the projector-type headlamp 90 for the power consumption of the adopted light source 92.

This means that, in order to obtain a predetermined brightness for the projector type headlamp 90, it is necessary to employ a light source 92 having a total light amount of about twice.
There is a problem that power consumption increases excessively, and the projector headlamp 90
There is a problem in that the temperature rises markedly and the structure becomes complicated due to the heat-resistant structure or the heat-dissipating structure, and it has been a problem to solve these problems.

[0005]

The present invention is, as a concrete means for solving the above-mentioned conventional problems, an elliptical reflecting mirror having a light source arranged at a first focal point, and reflecting from the elliptic reflecting mirror. In a projector-type headlamp, which comprises a shield plate which is disposed in a light flux to form a light distribution characteristic on the light flux, and a projection lens which projects the shape of the light flux formed by the shield plate, the shield plate is the first Provided is a projector-type headlamp, which is disposed between the bifocal point and the projection lens and at a position substantially on a center line, in a substantially horizontal plate shape having a lower surface as a mirror surface and an upper surface as a non-reflection surface. By doing so, it is possible to reduce the power consumption of the light source and solve the problem.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described in detail based on an embodiment shown in the drawings. Reference numeral 1 in FIGS. 1 and 2 denotes a projector-type headlamp (hereinafter abbreviated as headlamp 1) according to the present invention. The headlamp 1 includes a light source 2 such as a halogen lamp and the light source 2. Is composed of an ellipsoidal reflecting mirror 3 which is, for example, a compound ellipsoidal surface and is arranged at the first focal point F1, a shielding plate 4 which is placed in the luminous flux of the reflected light from the ellipsoidal reflecting mirror 3, and a projection lens 5. It is the same as that of the conventional example.

Here, in the conventional example, the shielding plate is provided so as to be substantially orthogonal to the luminous flux of the reflected light, that is, the center line Z of the headlamp 1, and the provided position is near the second focal point F2. In the present invention, the shielding plate 4 is provided near the first focus F1, that is, inside the second focus F2.
Is parallel to the center line Z, and is provided between the second focus F2 and the projection lens 5, that is, outside the second focus F2.

As described above, the shielding plate 4 is provided in the front-rear direction of the headlamp 1 so as to be parallel to the center line Z, that is, horizontally, and also horizontally in the left-right direction of the headlamp 1. The shielding plate 4 has a horizontal plate shape, and at the same time, its vertical position is the center line Z.
It is provided as a position in contact with or slightly above.

In addition, the lower surface of the shielding plate 4 is, for example, vapor-deposited with aluminum to form a mirror surface 4a, which totally reflects the light reaching the mirror surface 4a, while the upper surface is coated with, for example, black matte coating. The non-reflecting surface 4b is made to absorb all the light reaching the non-reflecting surface 4b.

Next, the operation and effect of the headlamp 1 of the present invention having the above structure will be described. First,
Considering the reflected light from the upper half 3a above the horizontal line Z of the elliptical reflecting mirror 3, the upper half 3 will be considered.
Since the shield plate 4 is provided closer to the projection lens 5 than the second focus F2, the reflected light from a is projected without being shielded by the shield plate 4 after once converging to the second focus F2. It reaches the lens 5, and is projected in the irradiation direction as a semicircle of the upper chord, which is similar to the passing beam of the conventional example.

On the other hand, the reflected light from the lower half portion 3b of the ellipsoidal reflecting mirror 3 is temporarily set to the second line because the shielding plate 4 is installed on the center line Z or slightly above the center line Z. Focus F
After converging to 2, it reaches the mirror surface 4a which is the lower surface of the shielding plate 4, is totally reflected by this mirror surface 4a, and reaches the projection lens 5 in a state where the traveling direction is changed downward.

At this time, the reflected light from the upper half 3a of the elliptical reflecting mirror 3 and the reflected light from the lower half 3b of the elliptical reflecting mirror 3 are symmetrical with respect to the center line Z. Therefore, the reflected light from the lower half 3b of the reflecting mirror 3 after being reflected by the mirror surface 4a has the same shape as the reflected light from the upper half 3a of the reflecting mirror 3, and therefore The shapes projected by the projection lens 5 in the irradiation direction are substantially the same.

Therefore, in the headlamp 1 of the present invention, the light reflected from the lower half portion 3b is not lost by the shielding plate as in the conventional example, and theoretically the brightness is about double. Will be obtained. That is, in other words, all the light of the light source 2 reflected by the ellipsoidal reflecting mirror 3 can be used as irradiation light.

FIG. 3 shows another embodiment of the present invention, and in the case of forming an actual headlamp 1,
When the headlamp 1 is for left-hand traffic, it may be required to emit an appropriate amount of upward light to the left shoulder side to improve the visibility of road signs and the like installed on the shoulder.

The present invention also meets the above requirements, and at this time, as shown in the drawing, the second focal point F2 of the shielding plate 4 is used.
If it is for the left side passage of the side 4c closer to the left side, the cutout portion 4 in which the cutout amount is increased in the right half from the center line Z toward the right end
If d is provided, the reflected light from the lower half portion 3b of the ellipsoidal reflecting mirror 3 that reaches the cutout portion 4d is projected by the projection lens 5 as upward light without being reflected. At this time, the amount of upward light increases as the distance from the center to the road shoulder side increases, so that the visibility of road signs and the like is improved without dazzling the oncoming vehicle.

In the actual implementation of the present invention, the shielding plate 4 takes into consideration the optical characteristics of the projection lens 5 such as astigmatism, chromatic aberration, and field curvature. For example, the projection lens 5 is used. When the field curvature and the chromatic aberration occur, the side 4c of the shielding plate 4 near the second focus F2 is formed as a curve corresponding to the degree of the field curvature as shown in FIG. The bright and dark boundary line between the dark portion and the dark portion where the shielding is performed is clarified, and the bright and dark boundary line is not colored due to chromatic aberration.

[0017]

As described above, according to the present invention, the shield plate is substantially horizontal between the second focal point and the projection lens and at a position substantially on the center line with the lower surface being a mirror surface and the upper surface being a non-reflective surface. Since the projector-type headlamp is arranged in the shape of a plate, the light from the lower half of the elliptical reflecting mirror, which was lost by being shielded by the shielding plate in the conventional configuration, is provided on the lower surface of the shielding plate. It shall be projected in the irradiation direction as the same shape as the light from the upper half of the ellipsoidal reflecting mirror, so that the total amount of light from the reflecting surface can be used as irradiation light.
This is an extremely excellent effect in reducing the power consumption of this type of projector-type headlamp.

Further, since the power consumption is reduced, the amount of heat generated is also reduced, and for example, a heat resistant structure or a heat dissipation structure is not required, and the structure of this type of projector type headlamp is simplified and excellent in cost reduction. It will play. Furthermore, by using a projector-type headlamp in which a cutout is provided at the end of the shield plate near the second focus so as to generate a prescribed upward light, the visibility of road signs on the shoulder side, for example, is also improved. It also has an excellent effect on performance improvement.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a projector-type headlamp according to the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a perspective view showing the main part of another embodiment of the projector type headlamp according to the present invention.

FIG. 4 is a perspective view showing a main part of still another embodiment of the present invention.

FIG. 5 is a cross-sectional view showing a conventional example.

[Explanation of symbols]

 1 ... Projector type headlamp 2 ... Light source 3 ... Elliptical reflecting mirror 3a ... Upper half 3b ... Lower half 4 ... Shielding plate 4a ... Mirror surface 4b ... Non-reflective surface 4c ... Second Side near the focus 4d ...... Notch 5 ...... Projection lens Z ...... Center line F1 ...... First focus F2 ...... Second focus

Claims (2)

[Claims] 1. An elliptical reflecting mirror having a light source arranged at a first focal point, a shielding plate arranged in a luminous flux reflected from the elliptical reflecting mirror to form a luminous intensity distribution characteristic on the luminous flux, and the shielding plate. In a projector type headlamp comprising a projection lens for projecting the shape of the light flux formed by, the shielding plate has a mirror surface on the lower surface between the second focus and the projection lens and at a position substantially on the center line. A projector-type headlamp, characterized in that it is arranged as a substantially horizontal plate having a non-reflective upper surface. 2. The projector type headlamp according to claim 1, wherein a cutout portion is provided at an end portion of the shielding plate near the second focus so as to generate a predetermined upward light.