JPH0314729Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial field of application> The present invention relates to a headlamp for an automobile, and more specifically to a bulb made of a main filament and a subfilament arranged in parallel in a direction orthogonal to the optical axis, and a paraboloid of revolution. The present invention relates to an automobile headlamp using a reflector.

<Conventional technology> This type of headlamp is specified not only to have the required power (light spread) in the passing beam mode (when the subfilament is lit), but also to prevent glare light from being emitted. It is configured to control light using a reflecting mirror and a front lens to obtain a desired light distribution pattern. Therefore, if a reflector with a large focal length is used, the dot-dashed line S ₂ in Figure 2
As shown in the light distribution pattern shown in , the light from the bulb is more concentrated, and when the subfilament is turned on, there is less glare (light distributed above the horizontal axis H) and it is easier to control with the front lens, but the power There is a problem that the (spreading of light) becomes smaller, and conversely, if the focal length of the reflector is made smaller, the broken line in Figure 2
As shown in the light distribution pattern shown in S ₁ , the light from the bulb is more diffused and the power increases, but at the same time glare light also increases, making it difficult to control with the front lens, which is a trade-off. still,
The light distribution patterns shown by S ₁ and S ₂ are light distribution patterns of only the reflecting mirror when the subfilament is turned on.

<Problems to be solved by the invention> The present invention was developed in view of these conventional problems, and aims to develop an automobile headlamp that can improve light distribution performance while suppressing an increase in glare. This is what we intend to provide.

<Means for solving the problem> The vehicle headlamp of the present invention that achieves the above purpose has the following features:
A bulb consisting of a main filament and a sub-filament arranged in parallel in a direction orthogonal to the optical axis is installed at the focal point of a rotating paraboloid reflector, and when the reflector is viewed from the front, it has four parts with horizontal and vertical axes. The reflective surface forming the diffused portion in the light distribution pattern and the reflective surface forming the hot zone portion are arranged so as to be descending from each other, and the focal length of the reflective surface forming the diffused portion in the light distribution pattern is made small in the hot zone portion. It is characterized by the fact that the focal length of the reflective surface forming the reflection surface is made large.

<Example> Hereinafter, an example of implementing the present invention will be described based on the drawings.

The headlight of the present invention is composed of a reflector 1, a bulb 2, a lamp body, a front lens, etc. (not shown), and the light from the bulb 2 is controlled by the reflector 1 and the front lens. The desired light distribution pattern is now being obtained.

The reflecting mirror 1 has a plurality of paraboloid of revolution reflecting surfaces 1a and 1b with different focal lengths F ₁ and F ₂ , and has a diffused portion S ₁ in the light distribution pattern (indicated by a broken line in the drawing).
The focal length _F1 of the reflecting surface 1a forming the light distribution pattern is made small, and the hot zone portion _S2 in the light distribution pattern is
Reflecting surface 1b forming (shown by a dashed line in the drawing)
The focal length F ₂ of the lens is formed to be large (F ₁ <F ₂ ). That is, when looking at the reflector 1 from its positive side, the horizontal axis H
The focal length F ₁ of the reflecting surface 1a for reflecting the light from the bulb 2 is made small (for example, _{F 1} =25) The focal length F 2 of the reflecting surface 1b is formed and placed at the upper left and lower right portions of the reflecting mirror 1 to reflect the light from the bulb 2 to form the hot zone portion S ₂ in the light distribution _pattern . It is configured as a multi-rotating parabolic reflecting mirror which is formed large (for example, F ₂ =30) and arranged in sections at the lower left and upper right portions of the reflecting mirror 1. In the illustrated embodiment, the reflective surface 1a with a small focal length F ₁ is divided and arranged in the upper left and lower right parts, and the reflective surface 1b with a large focal length F ₂ is divided in the lower left and upper right _parts. A reflective surface 1a with a small focal length F2 is placed at the lower left and upper right part, and a reflective surface 1 with a large focal length _F2 is
b may be arranged at the upper left and lower right parts.

Valve 2 is the same as before, main filament 2
A type in which a filament a and a subfilament 2b are arranged in parallel in a direction perpendicular to the optical axis is used, and it is installed at the focal point of the reflecting mirror 1.

Thus, the light from the bulb 2 is reflected and controlled by the multiple reflection surfaces 1a and 1b of the reflecting mirror 1, and further controlled by the front lens to obtain a required light distribution pattern that satisfies the standards.

That is, as shown in Fig. 2, the light from the bulb 2 (subfilament 2b) reflected by the reflecting surface 1a with a small focal length (F ₁ = 25) has a large power (spreading of light) and becomes glare light (horizontal light). The light distribution pattern S ₁ also has a lot of light (light distributed above the axis H), but
This is controlled downward by the front lens to form the light distribution pattern Sa for the diffuser part, and the light from the bulb 2 (subfilament 2b) reflected by the reflecting surface 1b with a large focal length (F ₂ = 30) is The light has a light distribution pattern _S2 with low power but less glare, so this is controlled by the front lens to create a light distribution pattern Sb for the hot zone part.
The light distribution pattern Sa for these diffusion parts is formed.
and the hot zone portion light distribution pattern Sb are combined to form a light distribution pattern that satisfies a predetermined standard.

<Effects of the invention> Since the automobile headlight of the invention is constructed in this way,
By forming a hot zone part in the light distribution pattern even with a reflective surface with a large focal length, it becomes easier to form a hot zone that suppresses an increase in glare light, and even with a reflective surface with a small focal length, a diffused part in the light distribution pattern can be formed. As a result, a light distribution pattern with high power can be easily obtained, and the light distribution performance can be generally improved while suppressing an increase in glare light.

Moreover, since the light distribution performance has been improved, the size of the headlight can be made smaller than the conventional one.

Therefore, the prescribed purpose can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a reflecting mirror showing an example of the implementation of the present invention, and FIG. 2 shows an example of the light distribution pattern when the subfilament is turned on. In the figure, 1 is a reflecting mirror, 1a and 1b are reflective surfaces, 2 is a bulb, 2a is a main filament, 2b is a sub-filament, Sa and S ₁ are light distribution patterns in the diffused part, and Sb and S ₂ are distribution patterns in the hot zone part. light pattern,
It is.

Claims (1)

[Scope of utility model registration request] A bulb consisting of a main filament and a sub-filament arranged in parallel in a direction orthogonal to the optical axis is installed at the focal point of a rotating paraboloid reflector, and when the reflector is viewed from the front, it has four parts with horizontal and vertical axes. The reflective surface forming the diffused portion in the light distribution pattern and the reflective surface forming the hot zone portion are arranged so as to be descending from each other, and the focal length of the reflective surface forming the diffused portion in the light distribution pattern is made small in the hot zone portion. An automobile headlamp characterized in that a reflective surface forming a large focal length is formed.