JP2001052506A - Headlamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a light distribution characteristics for collecting the direct light emitted by a light source with second and third reflective surfaces for controlling the light to the irradiating direction for increasing the intensity of a headlamp to improve visibility. SOLUTION: This headlamp is provided with a second reflective surface 6 having at least one focus and providing a prescribed characteristic to the direct light, and a third reflective surface 7 reflecting the reflected light from the second reflective surface 6 to the irradiation direction as almost parallel light at a position where a path of the light emitted by a light source 3 and reflected by a elliptical reflective surface 2 is not interrupted and the direct light emitted by the light source 3 reaches without being captured by the elliptical reflective surface 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicular lamp for lighting such as a headlamp and a fog lamp, and more specifically, to converge to a second focal point of an elliptical reflecting surface when generating light distribution characteristics. The present invention relates to a headlamp called a projector system by projecting a cross-sectional shape of a light beam by a projection lens.

[0002]

2. Description of the Related Art FIG. 9 shows an example of the configuration of a conventional headlamp 90 of this type, which is of a projector type. A light source 92 such as a filament of a halogen bulb is disposed, and the light from the light source 92 is transmitted to a second focus f2.
It is assumed to generate a light beam converging toward.

At an appropriate position between the light source 92 and the second focal point f2, there is provided a shielding plate 93 for shielding the lower half of the light beam Ph converging on the second focal point f2. Is formed in a semicircular shape with a lower chord, and this cross-sectional shape is projected by a projection lens 94 which is a convex lens-shaped aspherical lens having a focal point near the shielding plate 93.

Accordingly, the image projected by the projection lens 94 is inverted up and down and left and right, and has a semicircular shape of the upper chord, and does not include any upward light. A passing light distribution that does not cause dazzling to the driver of the vehicle can be obtained. In actual practice, in order to make it easy to confirm pedestrians,
In the case of left-hand traffic, the shape of the shielding plate 93 is adjusted so that the left half contains appropriate upward light.

[0005]

However, in the headlamp 90 having the above-described conventional configuration, first, as described above, approximately half of the light beam Ph from the elliptical reflection surface 91 is shielded by the shielding plate 93. Therefore, the luminous flux utilization rate for the light source 92 is reduced, and there is a problem that a bright headlamp 90 corresponding to the power consumption of the light source 92 cannot be obtained.

Second, since the projection lens 94 has a relatively small diameter of about 100 mm, it has a small light-emitting area when lit, and has a lens shape that does not cause irregular reflection when transmitting light. Therefore, visibility from oncoming vehicles or pedestrians is low, and the purpose of the headlamp 90 is one of
There is also a problem that the notification of the existence of the own vehicle is insufficient.

[0007]

According to the present invention, as a specific means for solving the above-mentioned conventional problems, there is provided a projector-type headlamp having a light source and an elliptical reflecting surface. The direct light has at least one focal point at a position where direct light from the light source, which does not block the optical path of the reflected light reflected on the reflecting surface and is not captured by the elliptical reflecting surface, reaches the light. A headlamp provided with a second reflecting surface that gives predetermined characteristics to the light source, and a third reflecting surface that reflects light reflected from the second reflecting surface as substantially parallel light in an irradiation direction. Is to solve the problem.

[0008]

Next, the present invention will be described in detail based on an embodiment shown in the drawings. FIG. 1 shows a first embodiment of the present invention, and a head lamp according to the present invention is indicated by reference numeral 1 in the figure. The headlamp 1 includes an elliptical reflecting surface 2 obtained by rotating an ellipse with a major axis as a rotation axis X, a light source 3 installed at a position of a first focal point f1 of the elliptical reflecting surface 2, and the elliptical reflecting surface. 2 is provided with a shielding plate 4 installed in the vicinity of the second focal point f2 and a projection lens 5 coaxial with the axis X, and is based on a projector system. Is the same as

Here, in the present invention, a second reflecting surface 6 and a third reflecting surface 7 are provided in addition to the elliptical reflecting surface 2, and in the first embodiment, the second reflecting surface 6 is provided.
Is formed as an elliptical surface obtained by rotating an ellipse whose first focus is the position of the light source 3 about the axis X. Therefore,
The first focal point f1 is substantially at the same position as the elliptical reflection surface 2.

At this time, the major axis Y of the ellipse 6 ′ constituting the second reflecting surface 6 is appropriately inclined such that the second focal point f 3 is located near the outer diameter of the elliptical reflecting surface 2. . Here, the degree to which the major axis Y is tilted is determined based on the balance with the third reflecting surface 7, which will be described in detail later.

The ellipse 6 'having the major axis Y inclined as described above is rotated about the axis X as a rotation axis. In this case, the curved surface obtained by rotating the ellipse 6 ′ causes a portion that physically interferes with the elliptical reflection surface 2 and also shields the light beam from the ellipse reflection surface 2, and will be described later. Since the light also interferes with the optical path of the third reflection surface 7, those portions are excluded, and the second reflection surface 6 having a substantially donut shape is obtained.

The third reflecting surface 7 is obtained by rotating a parabola whose center is at the second focal point f3 of the second reflecting surface and whose central axis Z is parallel to the axis X, with the axis X being the rotation axis. In addition, as in the case of the above-mentioned second reflection surface 6, a portion which physically interferes with the elliptical reflection surface 2 is removed, and the shape is substantially a donut.

Here, the positional relationship between the second reflecting surface 6 and the third reflecting surface 7 with respect to the elliptical reflecting surface 2 will be described. First, the second reflecting surface 6 is one of the light from the light source 3. The elliptical reflection surface 2 is provided for the purpose of using light that is not captured, that is, provided for the purpose of capturing direct light from the light source 3.

Accordingly, as described above, the light is provided in front of the elliptical reflection surface 2. In this direction, the reflected light from the elliptical reflection surface 2 is also radiated. Is provided with an opening 6a to prevent the occurrence of interference. However, the light from the elliptical reflecting surface 2
2, the area of the opening 6a can be reduced by providing the second reflecting surface 6 near the second focal point f2 of the elliptical reflecting surface 2. Thus, it is possible to improve the capture ratio for direct light.

On the other hand, the third reflecting surface 7 reflects the light reflected from the second reflecting surface 6 and reflects it again in the direction of the axis X of the headlamp 1. In order to avoid physical interference, it has to be provided on the outer periphery of the elliptical reflection surface 2, and it has a substantially donut shape having an opening 7 a like the second reflection surface 6.

Next, the operation and effects of the headlamp 1 according to the present invention having the above-described configuration will be described. In the above configuration, the elliptical reflection surface 2, the light shielding plate 4, and the projection lens 5 do not cause physical or optical interference with the second reflection surface 6 and the third reflection surface 7 even when they are provided. Therefore, light is projected from the projection lens 5 as a conventional projector system, and a light distribution characteristic for a low beam, for example, can be obtained.

On the other hand, the second reflecting surface 6 captures only the direct light from the light source 3 and converges the direct light to the second focal point f3. At this time, since the third reflecting surface 7 is formed as a paraboloid having a focal point at the second focal point f3 of the second reflecting surface 6, the reflected light from the second reflecting surface 6 is directed in the axis X direction. The light is converted into a parallel light beam and directed to the irradiation direction of the headlamp 1.

In the figure, reference numeral 8 denotes an outer lens that transmits both the light from the projection lens 5 and the light from the third reflecting surface 7. A lens cut 8a is provided at a position where the parallel light rays from the three reflection surfaces 7 are transmitted, and the light distribution characteristics from the projection lens 5 can be matched. The reference numeral 9 in the drawing denotes an extension cover. The extension cover 9 covers the back side of the second reflection surface 6 when the inside of the headlamp 1 is seen through the outer lens 8. Is to improve.

That is, according to the present invention, since the direct light that cannot be collected by the conventional configuration can be used as the irradiation light, the light flux utilization rate for the light source 3 can be improved, and the bright headlamp can be improved. 1 can be realized. In general, direct light that is not controlled is harmful light such as a factor of dazzling light, but becomes effective light by controlling the second reflection surface 6 and the third reflection surface 7 according to the present invention, The quality of the light distribution characteristics is also improved.

FIG. 2 shows a second embodiment of the present invention. In the second embodiment, the second reflection surface 6 and the third reflection surface 7 are provided. It is the same as the first embodiment, and their reflecting surfaces 6, 7
Is completely the same as the previous embodiment.

However, in the second embodiment, a movable light shielding plate 10 is provided in the vicinity of the second focal point f3 of the second reflecting surface 6 so as to be movable between the passing position S and the traveling position M. When the passing position S is set, the reflected light from the second reflecting surface 6 is blocked from reaching the third reflecting surface 7.

In this way, the light emitted from the headlamp 1 is emitted from only the projection lens 5 as shown in FIG. 3 when the movable shielding plate 10 is at the passing position S. When the movable shielding plate 10 is at the traveling position M, the light is radiated from the entire surface of the outer lens 8 as shown in FIG.

At this time, since the upward light of the light from the projection lens 5 is eliminated by the light shielding plate 4, when the movable shielding plate 10 is at the passing position S, the light distribution of the headlamp 1 is a passing light distribution. . In addition, since light rays parallel to the axis X are emitted from the third reflection surface 7, when emitted from both the projection lens 5 and the third reflection surface 7, the downward light and the front light are added and travel. Light distribution can be obtained.

FIG. 5 shows a third embodiment of the present invention. Also in the third embodiment, a second reflecting surface and a third reflecting surface are provided, which is different from the first and second embodiments. Similarly, in the third embodiment, the second reflecting surface 16 is formed by a hyperboloid obtained by rotating one of the hyperbolas about the axis X.

FIG. 6 illustrates the properties of the hyperbola. A set of hyperbolas h1 and h2 have focal points h1a and h2a, respectively. Here, one of the hyperbolas h1 is adopted as a reflection surface, and a light source is arranged at the focal point h2a of the hyperbola h2 that has not been adopted, and light from this light source is reflected on one of the hyperbolas h1. The trajectory of the ray after reflection is the focal point h1a of the hyperbola h1.
It is the same as being radiated from.

In the third embodiment, the above-mentioned property is utilized, and the second reflection surface 16 is formed as a hyperboloid obtained by rotating one hyperbola with the other focal point being the position of the light source 3. ing. Accordingly, the third reflecting surface 1 that reflects light from the second reflecting surface 16 as parallel light rays parallel to the axis X
Numeral 7 is formed as a paraboloid having the focal point f4 of the second reflecting surface 16 as a focal point. The opening 16a is provided in the second reflecting surface 16 so as not to block the reflected light from the elliptical reflecting surface 2, and the like, as in the first and second embodiments.

FIG. 7 shows a fourth embodiment of the present invention. In the fourth embodiment, the second reflecting surface 26 is formed as a paraboloid having a focal point f5 at the position of the light source 3. However, in the fourth embodiment, the parabola p, which is the basis for forming the second reflecting surface 26, points the axis pa passing through the focal point f5 in the direction in which the third reflecting surface 27 is provided, for example, at 45 °. It is to be changed.

The parabola obtained by rotating the parabola p set as described above about the axis X is the second reflecting surface 2.
6, the light from the light source 3 is converted into a parallel ray parallel to the axis pa when the light from the light source 3 is reflected toward the third reflection surface 27. Therefore, in the fourth embodiment, the third reflecting surface 27 may be a plane mirror.

FIG. 8 shows a fifth embodiment of the present invention. In the fifth embodiment, a light source 13 is provided with two main filaments 13a and a sub-filament 13b like an H-4 type halogen lamp or the like. What has been adopted. And, for example, in the case of the first embodiment,
The elliptical reflection surface 2 with respect to the main filament 13a side,
Second reflecting surface (not shown) 6, third reflecting surface 7 (not shown)
Are formed, and a light distribution is obtained by lighting the main filament 13a.

Accordingly, the sub-filament 13b is composed of the elliptical reflection surface 2, the second reflection surface 6 (not shown), and the third reflection surface 7
(Not shown) or the like, a so-called out-of-focus state occurs, and when the sub-filament 13b is turned on, the light distribution characteristic is different from that when the main filament 13a is turned on.

At this time, it is possible for a person skilled in the art to predict how much the amount and direction of displacement of the sub-filament 13b with respect to the main filament 13a will affect the change in the shape of the light distribution characteristics. The position of the sub-filament 13b may be determined so as to obtain the intended traveling light distribution, or the above-described respective beams may be obtained so that a passing beam and a traveling beam can be obtained with respect to a ready-made bulb such as an H-4 type bulb. It is only necessary to adjust the reflection surfaces 2, 6, 7 and the lens cut 8a.

[0032]

As described above, according to the present invention, the optical path of the reflected light emitted from the light source and reflected on the elliptical reflection surface is not interrupted and is not captured by the ellipse reflection surface. At a position where the direct light reaches, a second reflecting surface having at least one focal point and providing predetermined characteristics to the direct light, and reflecting the reflected light from the second reflecting surface in the irradiation direction as substantially parallel light. By using a headlamp with a third reflecting surface, the direct light from the light source, which was conventionally invalid, is collected by the second reflecting surface and the third reflecting surface, and the shape etc. is controlled in the irradiation direction The headlamp can be used to form a light distribution characteristic as the headlamp is turned, and the brightness of this kind of headlamp is increased, and the effect of improving the performance such as the visibility is extremely excellent.

Further, by collecting the direct light, the amount of harmful light radiated to the outside is reduced, and an excellent effect is obtained in terms of prevention of dazzling. In addition, the light emitting area of the headlamp is increased by the second reflecting surface and the third reflecting surface, so that visibility from oncoming vehicles, pedestrians, and the like is also improved, and excellent effects are also obtained in terms of improving safety. .

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of a headlamp according to the present invention.

FIG. 2 is a sectional view showing a second embodiment of the headlamp according to the present invention.

FIG. 3 is an explanatory diagram showing a light emitting state of a lens surface when passing light is distributed in the second embodiment.

FIG. 4 is an explanatory diagram showing a light emitting state of a lens surface when a traveling light distribution is used in the second embodiment.

FIG. 5 is a sectional view showing a third embodiment of the headlamp according to the present invention.

FIG. 6 is an explanatory diagram showing hyperbolic characteristics.

FIG. 7 is a sectional view showing a fourth embodiment of the headlamp according to the present invention.

FIG. 8 is a sectional view showing a main part of a fifth embodiment of the headlamp according to the present invention.

FIG. 9 is a sectional view showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Headlamp 2 ... Elliptical reflection surface 3, 13 ... Light source 13a ... Main filament 13b ... Subfilament 4 ... Shielding plate 5 ... Projection lens 6, 16, 26 ... Second reflection surface 7, 17, 27: third reflecting surface 8: outer lens 9: extension cover 10: movable light shielding plate X: axis of headlamp

Claims (7)

[Claims] 1. A headlamp of a projector type including a light source and an elliptical reflecting surface, wherein an optical path of reflected light emitted from the light source and reflected on the elliptical reflecting surface is not interrupted and captured by the elliptical reflecting surface. A second reflection surface having at least one focal point and providing a predetermined characteristic to the direct light is provided at a position where the direct light from the light source emitted without being reached, and a reflection from the second reflection surface. A headlamp provided with a third reflection surface that reflects light in a direction of irradiation as substantially parallel light. 2. The second reflecting surface is an elliptical surface having a first focal point on the light source, and the third reflecting surface is a parabolic surface that is located substantially at the second focal point of the second reflecting surface. The headlamp according to claim 1, wherein: 3. A movable shielding plate is provided in the vicinity of the second focal point of the second reflecting surface so as to open and close an optical path to the third reflecting surface, and the third reflecting surface is opened and closed by opening and closing the movable shielding plate. 3. The headlamp according to claim 2, wherein the traveling light distribution and the passing light distribution are switched according to the presence or absence of reflected light from the light source. 4. The second reflecting surface is a hyperboloid having a focal point on the optical axis of the headlamp, and the third reflecting surface is a paraboloid having a focal point substantially equal to the focal point of the second reflecting surface. The headlamp according to claim 1, wherein: 5. The headlamp according to claim 1, wherein the second reflecting surface is a paraboloid having a focus on the light source, and the third reflecting surface is a plane mirror. 6. The light source is one or two,
The headlamp according to claim 1, wherein the first is located at a first focal point of the elliptical reflecting surface. 7. The headlight according to claim 1, wherein an extension cover is provided on the second reflection surface to cover the headlamp from the irradiation direction side.
Headlamp.