JPH07130205A - Headlight for automobile - Google Patents

Abstract

PURPOSE:To use all the emitted light from a main mirror and change upper/ lower light distribution freely by placing a light source roughly at the focal point of the main mirror and changing inclination of a flat reflector mirror for changing radiation direction from the main mirror and thereby controlling the light distribution. CONSTITUTION:At the time of high beam, normal line of flat reflector mirrors 9a-9d is made perpendicular to an optical axis 'O'. The downward light 11a from the source 7 is reflected by a main mirror 8, so that is passes between the mirror 9a-9d and is emitted as a radiation light 11b. On the other hand, the upward light 12a is reflected by the mirror 8, so that is is emitted as a radiation light 12b. Then, at the time of a low beam, normal of mirror 9a-9d is made in parallel to the optical axis 'O'. Of the radiation light from the light source 7, the radiation light 13a downward, for example, is reflected by the mirror 8 and enters the mirror 9c and thus the radiation light 13a is emitted partly as a radiation light 13b. Of the radiation light 13a, 13c reflected by the mirror 9c returns to the light source 7 through a light path the same as for the radiation light 13a and then is reflected by the mirror and is emitted as a radiation light 13d.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle headlight.

[0002]

2. Description of the Related Art FIG. 3 is a sectional view showing an example of a conventional vehicle headlamp. As shown in FIG. 3, a conventional automotive headlamp that can switch a radiant light flux used in an automobile or the like has a low beam filament 1 and a high beam filament 2.
Has a low beam light-shielding plate 3 for blocking downward light. Therefore, the light of the low-beam filament 1 is only upward light, is reflected by the reflecting surface 4 having a parabolic surface, and becomes a low beam through the first condensing lens portion 5 that disperses it in a wide area in front. On the other hand, the light of the high-beam filament 2 is also emitted downward, so that it is reflected by the reflecting surface 4 and transmitted through the second condensing lens portion 6 that converges in a narrow area in front to form a high beam. be able to.

[0003]

However, the above-described conventional automotive headlamp requires the low-beam filament 1 and the high-beam filament 2 for switching the radiant flux, and in order to blink these,
There is a drawback that two relays having a large current capacity are required, and further, there is a drawback that the low beam light-shielding plate 3 reduces the light utilization efficiency.

In recent years, as described in Japanese Patent Laid-Open No. 2-72502, a liquid crystal screen is arranged on the surface of the second condenser lens portion 6 in FIG. 3, and a transparent state is changed to an opaque state by applying a control voltage. It has been devised that the transmittance of light can be controlled by changing the state to a different state and switching between high beam and low beam can be formed by one filament. However, even in this case, when a low beam is used, the light is blocked by the liquid crystal screen, and the light utilization efficiency is reduced.

The present invention solves the above-mentioned problems, and it is possible to switch between a high beam and a low beam with one light source, and it is possible to effectively use all the irradiation light from the light source even when the low beam is used. The purpose is to provide.

[0006]

In order to solve these problems, a vehicle headlamp according to the present invention includes a light source and a reflecting surface which partially surrounds the light source and collects the light emitted from the light source. At least a part of which is a parabolic surface, a reflecting surface is a flat surface, a planar reflecting mirror that changes the irradiation direction of a part of the reflected light from the primary mirror, and a control means that controls the planar reflecting mirror. The light distribution is controlled by installing a light source at a substantially focal position of a parabolic surface of the main mirror, and changing the inclination of the plane reflecting mirror by the control means.

Further, the light source is a discharge lamp. Also, the normal of the reflecting surface of the flat reflecting mirror can change its inclination in a substantially vertical direction, and the normal of the reflecting surface of the flat reflecting mirror can change its inclination in a substantially horizontal direction, Furthermore, both the one that changes the inclination of the plane reflecting mirror in the substantially vertical direction and the one that changes the inclination in the substantially horizontal direction are used.

Further, the flat reflecting mirror is a semi-transmissive mirror that transmits at least a part of the irradiation light from the primary mirror, and further, at least a part of the primary mirror or the flat reflecting mirror is wavelength selective transmission. It has a characteristic and a wavelength selective reflection characteristic.

[0009]

With this configuration, by changing the inclination of the plane reflecting mirror, a part of the irradiation light from the light source with the light source placed near the focal point of the parabolic surface of the main mirror is reflected by the main mirror and the plane reflection is performed. After being reflected by the mirror, it returns to the light source through the same optical path, is reflected by the primary mirror, and is then illuminated through the opening. Therefore, all the illumination light from the primary mirror is effectively used. The light distribution can be changed as well.

By changing the inclination of the reflection surface of the flat reflecting mirror in a substantially vertical direction, a part of the irradiation light reflected by the flat reflecting mirror is changed in the vertical direction and emitted. Therefore, all of the irradiation light from the primary mirror can be effectively used, and one light source can arbitrarily change the upper and lower light distributions.

Further, by changing the inclination of the reflection surface of the flat reflecting mirror in a substantially horizontal direction, a part of the irradiation light reflected by the flat reflecting mirror is emitted while changing the irradiation direction in the horizontal direction. Therefore, all the irradiation light from the primary mirror can be effectively used, and the left and right light distributions can be changed by one light source.

Further, since the flat reflecting mirror is a semi-transmissive mirror, a part of the irradiation light incident on the flat reflecting mirror is transmitted through the flat reflecting mirror and is emitted, so that the irradiation light is not blocked but is appropriately cut off. It is possible to make the driver easily recognize the sign, the guide plate, etc. by illuminating them upward.

Further, by making part of the main mirror or the plane reflecting mirror have the wavelength selective transmission characteristic and the wavelength selective reflection characteristic, the spectral distribution of the emitted irradiation light can be arbitrarily changed, The light color can be changed arbitrarily.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 (a) is a cross-sectional view showing a vehicle headlamp at high beam according to an embodiment of the present invention, FIG.
Is a front view thereof. FIG. 2 (a) is a sectional view showing a vehicle headlamp at the time of low beam of the same embodiment, and FIG. 2 (b) is a front view thereof. The illumination device of the embodiment is shown in FIGS. 1 (a) and 2 (a).
As shown in, a point light source 7 (for example, a halogen bulb or a short arc type metal halide lamp),
A main mirror 8 whose reflecting surface for converging light emitted from the light source 7 is a paraboloid of revolution, and flat reflecting mirrors 9a, 9b, 9c, 9d arranged in the lower half of the front surface of the opening of the main mirror 8, control It is composed of a motor (not shown) as a means.

The rotating shafts 10a, 10b, 10c and 10d of the plane reflecting mirrors 9a, 9b, 9c and 9d are mechanically connected to a motor (not shown) which is a control means, so that the motor can rotate. By the plane reflecting mirror 9
a, 9b, 9c and 9d are rotating shafts 10a, 10b and 10
It rotates about c and 10d as fulcrums, that is, the inclinations of the plane reflecting mirrors 9a, 9b, 9c and 9d are changed. The plane reflecting mirrors 9a, 9b, 9c and 9d are semi-transmissive mirrors.

At the time of high beam, as shown in FIG. 1, the normals of the plane reflecting mirrors 9a, 9b, 9c, 9d are set to be perpendicular to the optical axis O, and the light 11a emitted downward from the light source 7 is set. Is reflected by the primary mirror 8, and the plane reflecting mirrors 9a, 9b,
It passes through between 9c and 9d and is emitted as irradiation light 11b. On the other hand, the upward irradiation light 12a is reflected by the main mirror 8 and then emitted as irradiation light 12b.

At the time of low beam, as shown in FIG. 2, the normal lines of the plane reflecting mirrors 9a, 9b, 9c and 9d are set to be parallel to the optical axis O, and the irradiation light from the light source 7 is set. Of these, for example, downward irradiation light 13a is reflected by the main mirror 8, enters the flat reflecting mirror 9c, and part of the irradiation light 13a is emitted as it is as irradiation light 13b. Further, of the incident irradiation light 13a, the irradiation light 13c reflected by the flat reflecting mirror 9c passes through the same optical path as the irradiation light 13a, and the light source 7
Then, after being reflected by the main mirror 8, it is emitted as irradiation light 13d.

Therefore, the high beam and the low beam can be switched by rotating the plane reflecting mirrors 9a, 9b, 9c and 9d with only one light source 7, and all the irradiation light from the light source 7 is emitted even during the low beam. Since the flat reflecting mirrors 9a, 9b, 9c, 9d can be effectively used as the lights 13b, 13d and a part of the irradiation light 13b is transmitted, the oncoming vehicle is dazzled. It is possible to illuminate information such as a sign or a guide board displayed above without making it easier for the driver to obtain information.

In this embodiment, of the irradiation light from the light source 7, the irradiation light 13a incident on the flat reflecting mirror 9c has been described as an example, but the same effect can be obtained with the flat reflecting mirrors 9a, 9b and 9d. It goes without saying that you can get it.

In the present embodiment, the plane reflecting mirror 9
Although a, 9b, 9c, and 9d are installed on the lower side of the main mirror 8 in the vertical direction to switch between the high beam and the low beam, they are installed on either the left or right side of the main mirror 8 so that the vehicle travels in the direction of travel. It may be used as a cornering lamp when changing.

Further, by disposing by individually controlling a plurality of flat reflecting mirrors, which are installed so as to cover the upper and lower sides of the main mirror 8, that is, the front surface of the opening of the main mirror 8 and which can change the inclination in an arbitrary direction, respectively. The degree of freedom of light can be increased.

In the present embodiment, the plane reflecting mirror 9
The normals of a, 9b, 9c and 9d are switched to be vertical or horizontal to the optical axis O, but the plane reflecting mirrors 9a, 9b, 9c,
Both surfaces of 9d are mirror surfaces, and the optical axis O and the flat reflecting mirrors 9a, 9
By setting an arbitrary angle with respect to the normals of b, 9c, and 9d, it is possible to obtain an arbitrary light distribution.

Further, in this embodiment, the plane reflecting mirror 9
By individually controlling a, 9b, 9c, and 9d, the degree of freedom of light distribution can be increased. Further, in this embodiment, the plane reflecting mirrors 9a, 9b, 9c and 9d are replaced by the primary mirror 8.
By placing it on the lower side (upper side), the normal of which changes the tilt in the vertical direction, and by placing the plane reflecting mirror that changes the tilt of the normal line in the horizontal direction on the upper side (the lower side), It can serve both as a switch and as a cornering lamp.

In the present embodiment, the plane reflecting mirror is 9
Although four sheets of a, 9b, 9c, and 9d are used, it goes without saying that the same effect can be obtained with any number. Further, in the present embodiment, the control means is a motor (not shown), but it is a plane reflecting mirror such as one that is switched in two steps by using an electromagnet and a permanent magnet, or is switched by a spring and a lever or a wire. It goes without saying that the same effect can be obtained by using a material capable of changing the inclinations of 9a, 9b, 9c and 9d.

Further, in the present embodiment, at least a part of the main mirror 8 and the plane reflecting mirrors 9a, 9b, 9c, 9d have wavelength selective transmission and wavelength selective reflection characteristics, so that the main mirror 8 or the plane reflecting mirror can be formed. Mirrors 9a, 9
Since some wavelength components of the irradiation light incident on b, 9c, and 9d are transmitted or reflected, the wavelength component of the irradiation light can be set arbitrarily, that is, the light color of the irradiation light can be adjusted arbitrarily.

Further, in this embodiment, the light source 7, the main mirror 8 and the plane reflecting mirrors 9a, 9b, 9c and 9d are constructed. However, if necessary, the main mirror 8 and the plane reflecting mirrors 9a, 9b and 9d are provided.
Even if a translucent member such as a condenser lens is arranged on at least a part between c and 9d, or at least a part on the irradiation direction side of the flat reflecting mirrors 9a, 9b, 9c and 9d, the same effect is not obtained. Needless to say.

Further, in this embodiment, the plane reflecting mirror 9 is used.
Although a, 9b, 9c and 9d are semi-transmissive mirrors, it goes without saying that the same effect can be obtained even if they are total reflection mirrors.

[0028]

As described above, according to the present invention, the following effects can be obtained. (1) A single light source can switch between a high beam and a low beam, and all irradiation light from the light source can be effectively used even during a low beam. (2) A cornering lamp can be obtained by changing the light distribution in the left and right directions. (3) The degree of freedom of light distribution can be increased, and arbitrary light distribution can be achieved. (4) It becomes possible to switch between high beam, low beam, and cornering lamps. (5) Not only the upward irradiation light is blocked, but also the upward irradiation light is appropriately moderated so that the driver can easily recognize the signs and the guide plates. (6) The light color of the irradiation light can be adjusted.

[Brief description of drawings]

FIG. 1 (a) is a cross-sectional view showing a vehicle headlamp at the time of a high beam according to an embodiment of the present invention. (B) It is a front view which shows the vehicle headlamp at the time of a high beam of one Example of this invention.

FIG. 2 (a) is a cross-sectional view showing a vehicle headlamp at the time of low beam according to an embodiment of the present invention. (B) It is a front view which shows the vehicle headlamp at the time of a low beam of one Example of this invention.

FIG. 3 is a sectional view schematically showing a conventional automobile headlamp.

[Explanation of symbols]

7 light source 8 primary mirror 9a-9d plane reflecting mirror 10a-10d rotation axis 11a, 11b, 12a, 12b, 13a-13d, 1
4a, 14b Irradiation light O optical axis

Claims (7)

[Claims] 1. A light source, a main mirror that partially surrounds the light source and collects the irradiation light from the light source, and at least a part of the reflection surface is a parabolic surface, and the reflection surface is a flat surface. A flat reflecting mirror that changes the irradiation direction of a part of the reflected light from the mirror, and control means that controls the flat reflecting mirror, and the light source is installed at a substantially focal position of the parabolic surface of the primary mirror, and the control is performed. A vehicle headlamp, characterized in that the light distribution is controlled by changing the inclination of the plane reflecting mirror by means. 2. The vehicle headlamp according to claim 1, wherein the light source is a discharge lamp. 3. The vehicle headlamp according to claim 1, wherein the normal line of the reflecting surface of the plane reflecting mirror changes its inclination in a substantially vertical direction. 4. The vehicle headlamp according to claim 1, wherein the normal line of the reflecting surface of the plane reflecting mirror changes its inclination in a substantially horizontal direction. 5. The flat reflecting mirror according to claim 3 and claim 4.
3. The vehicle headlight according to claim 1 or 2, wherein both the flat reflecting mirror according to claim 1 and 2 are used. 6. The vehicle headlamp according to claim 1, wherein the plane reflecting mirror is a semi-transmissive mirror that transmits at least a part of the irradiation light from the primary mirror. 7. The vehicle headlamp according to claim 1, wherein at least a part of the primary mirror or the plane reflecting mirror has a wavelength selective transmission characteristic and a wavelength selective reflection characteristic.