JPH0237641B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a lamp for a vehicle such as an automobile, and particularly relates to a reflector structure of a headlamp.

[Prior Art] Conventionally, a paraboloid of revolution is often used as a reflector for this type of headlamp, and the optical role of the reflector is to obtain parallel light rays and to determine light distribution characteristics. In the past, the mainstream of lighting equipment design relied exclusively on the lens cut made on the front lens, but in recent years, as a new direction in lighting equipment design, the reflector also has all or no light distribution characteristics. , a lighting fixture design method has been proposed in which this part is taken care of. An example of this is JP-A No. 58-145002, in which a plurality of reflecting surfaces are arranged in parallel, each having a parabolic surface in the vertical direction and a specific curved surface in the horizontal direction, and compound reflection. By making it a surface, it is possible to obtain light rays that do not spread in the vertical direction but spread in the horizontal direction in accordance with the light distribution characteristics. What is shown in Fig. 3 is a reflecting mirror with a composite reflecting surface as explained above, in which a plurality of reflecting surfaces 1a to 1h divided in the left and right direction are joined in parallel (the number is arbitrary) to form a single reflecting surface. It constitutes mirror 1.
Moreover, what is shown in FIG. 4 shows the basic principle of a method of obtaining light distribution characteristics using this reflecting mirror 1, and for ease of understanding, the number of reflecting surfaces will be limited in explanation. Envelopes 1A, 1B, 1C,
1G are the reflective surfaces 1a, 1, respectively.
The reflected light is given a predetermined spread by b, 1c, and 1g, and by making these reflected lights overlap at a predetermined position in front of the car, a desired predetermined light distribution characteristic is obtained. .

[Problems to be Solved by the Invention] However, in the prior art described above, the reflection from the reflecting surfaces 1a to 1h, each of which is approximately rectangular and has a relatively clear boundary line, is Since this method obtains light distribution characteristics by superimposing light, although this tendency can be reduced by increasing the number of reflective surfaces, there is still a clear difference in illuminance that occurs at the interface of superimposed light. When this step passes over an illuminated object while the car is driving, the light suddenly becomes brighter or darker, causing the driver to detect uneven light distribution, causing discomfort and reducing visibility. This caused problems. FIG. 5 is a more detailed study of the above problem, and the figure shows the reflecting mirror 1.
The figure is cut along the horizontal line and a portion is shown enlarged. Normally, the reflector 1 with this type of composite reflective surface is formed of a metal plate in order to maintain precision due to its complex shape, so when mirror-finishing the surface, it is used as a pre-treatment. ,
In order to obtain a smoother surface, a resin coating 2 called an undercoat is applied. At this time, the joint portion of each reflective surface indicated by arrow R in the figure is the resin coating 2.
is attached somewhat thickly to produce a slight inner radius R, and this inner radius R acts in the same way as a convex lens to focus the reflected light on the boundary line portion,
It turned out that this made the difference even more noticeable.

[Means for Solving the Problems] As a specific means for solving the above-mentioned conventional problems, the present invention provides a single reflecting mirror by joining a plurality of reflecting surfaces, and the reflecting mirror has a plurality of reflecting surfaces. In a reflecting mirror for a vehicle headlamp which is undercoated and then subjected to a mirror finish, the adjoining joining parts of the reflecting surfaces are provided with joining parts curved in a direction away from the light source of the headlamp. The conventional problems are solved by providing a composite reflector equipped with a joint characterized by the following.

[Example] Next, the present invention will be described in detail based on an example shown in the drawings. In order to facilitate understanding, the same parts as in the conventional example will be described with the same reference numerals.

FIG. 1 shows a partially enlarged view of a headlamp reflector 1 cut along a horizontal center line, and shows a reflection surface 1 similar to that shown in the conventional example.
c, 1d, 1e and their respective joints are shown. However, at the joint part, there is a direction away from the light source (not shown), that is, a reflector 1
When viewed from the side, a groove-shaped joint S1 is provided so as to form a recess and create a radius r from the outer surface toward each reflective surface. By doing this, even if the undercoat 2 is applied as in the conventional example, by adjusting the radius r, it is possible to prevent the inner surface radius described in the conventional example from occurring in the joint S1. More positively, it becomes possible to maintain the radius from the outer surface side even after applying the undercoat. The effect of providing an outer radius at the end of each reflective surface, for example, the reflective surface 1d, is completely opposite to the effect of providing an inner radius at the end of the conventional reflective surface described above. , the outer radius acts as a concave lens,
To eliminate the formation of a clear boundary line by diffusing the vertical side boundary line part of the rectangular reflected light projected forward and gradually darkening it. This allows the light distribution characteristics to be extremely natural. According to the results of numerous studies conducted by the inventor in order to complete the present invention, the value of the radius r from the outer surface of the reflecting mirror 1 is too small if it is less than 1 mm, and no effect can be recognized, and if it is more than 10 mm, the above-mentioned It has been confirmed that a large portion of the reflective surface falls under the influence of the radius, resulting in too much diffusion and lack of a center of light distribution, resulting in inappropriate light distribution.

What is shown in FIG. 2 is another embodiment of the present invention, in which the junction S2 is provided with the radius r from the outer surface described above only at one end of the reflective surface, By doing this, you can obtain rectangular reflected light with one side having a clear boundary line and the other side having a diffused boundary line, so for example, you can limit the direction of light distribution such as in a passing beam. This is an effective method when used when receiving treatment.

[Effects of the Invention] As explained in detail above, the present invention provides
A plurality of reflective surfaces are joined together to form a single reflective mirror, and the reflective surface is under-coated and then mirror-treated.The reflective mirror for a vehicle headlamp is attached to the adjacent joined portion of the reflective surface as the light source of the headlamp. By providing a joint that curves away from the vehicle, it eliminates the uneven light distribution that occurs in headlamps that use this type of composite reflector, eliminating the discomfort felt by the driver, and improving visibility.
This has an excellent effect on safe driving.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing the main parts of an embodiment of a composite reflector provided with a joint according to the present invention, FIG. 2 is a cross-sectional view showing the main parts of another embodiment of the present invention, and FIG.
The figure is a front view showing a conventional example, FIG. 4 is an explanatory diagram showing light distribution characteristics according to the conventional example, and FIG. 5 is a sectional view showing main parts of the conventional example. 1...Reflecting mirror, 1a to 1h...Reflecting surface, 2...
Undercoat, S1, S2...junction.

Claims (1)

[Claims] 1. A plurality of reflecting surfaces are joined together to form a single reflecting mirror,
In the reflecting mirror for a vehicle headlamp, the reflecting mirror is subjected to undercoating and then mirror-finishing, and the adjoining joining parts of the reflecting surfaces are provided with joining parts curved in a direction away from the light source of the headlamp. A composite reflector with a joint that is characterized by: 2. A composite reflecting mirror provided with a joint according to claim 1, wherein the curved joint has a radius of r=1 mm to r=10 mm. 3. Providing a joint according to claim 1, wherein the joint provided at the joint of each of the reflective surfaces is provided on one of the adjacent reflective surfaces. Composite reflector.