JPS6137122Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a headlamp unit equipped with a front lens made of synthetic resin.

A headlight unit using a front lens made of synthetic resin instead of a front lens made of glass, as shown in Figs. 1 to 3, has a reflector a made of glass, metal, or synthetic resin, and a It includes a synthetic resin front lens b disposed on the front surface and a bulb c.

In detail, the reflector a has a reflective surface coated with a reflective thin film on its inner surface in the shape of a paraboloid of revolution, and a bulb holder h is fixed to the rear opening of the reflector a.
The subfilament d of the bulb c, which is detachably attached to the reflector a, is located in front of the focal point f of the reflector a and on the optical axis i, and its lower half is covered with a light shielding plate g, and the subfilament d of the bulb c is detachably attached to the main The filament e is located behind the focal point f and slightly below the optical axis i. Therefore, the light rays emitted from the main filament e and reflected on the inner surface of the reflector a will be in a slightly diffused state, but the light rays emitted from the sub-filament d will be reflected by the front lens as shown in FIGS. 1 to 3. The light is focused on the sign b′ near the center of b, and at the same time the subfilament d
The heat rays (infrared rays) emitted from the reflector a and reflected by the inner surface of the reflector a also concentrate on the condenser b'. Also,
The atmosphere inside the unit, which is in a substantially sealed state, is heated by heat rays (infrared rays), causing a convection phenomenon and remaining above the inside of the unit. Therefore,
Due to these phenomena, the upper part b'' of the light condensing part b' of the front lens b made of synthetic resin becomes higher in temperature, and there is a risk that the front lens b may be deformed or softened.

In view of the above circumstances, the present invention is an inexpensive headlamp unit that prevents deformation and softening of the front lens, especially the upper part of the lens, even if the light reflected from the reflector is focused on the front lens made of synthetic resin. The purpose is to provide

In order to achieve the above object, the present invention provides a headlamp unit in which a reflective thin film is formed on the inner surface of the reflector by metal vapor deposition via an undercoat to form a reflective surface. The reflective thin film of the front lens is removed to make the area non-reflective, thereby preventing heat rays from concentrating on the upper part of the front lens, thereby preventing deformation or softening of the synthetic resin lens. .

Hereinafter, one embodiment of the headlamp unit according to the present invention will be described with reference to FIGS. 4 to 6.

This example is an example applied to a rectangular headlamp unit for a vehicle, and 1 is a reflector made of glass, metal, or synthetic resin, and the reflector has a substantially paraboloid-shaped reflective surface 13 formed on its inner surface. A valve holder 11 is fixedly installed in a rear opening opened approximately in the center of the rear part. The bulb 2 has a light-shielding paint applied to its tip and has a subfilament 21 and a main filament 22 inside.
1, a light shielding plate 23 is located at the bottom of the subfilament 21.
This is a so-called halogen _H4 bulb that is installed to cover approximately the lower half of the bulb. And this valve 2
The bulb holder 1 is arranged so that the sub-filament 21 is located in front of the focal point f of the reflector 1 and on the optical axis i, and the main filament 22 is located behind the focal point f and slightly below the optical axis i.
1 is removably attached. Specifically, the flange portion 24 of the valve 2 is pressed against the bulb holder 11 by a pressing spring 5 that is removably engaged with the bulb holder 11.

The front lens 3 is made of transparent synthetic resin such as polycarbonate or acrylic, and its periphery 31 is an annular recess 1 formed on the front periphery of the reflector 1.
2 through an adhesive 4 in an airtight manner.

Next, regarding the above-mentioned reflective surface, a non-reflective portion 14 is formed on the reflective surface 13. To be more specific, the reflective surface 13 is formed by depositing aluminum or the like through an undercoat 15 applied to the substantially paraboloid-shaped inner surface of the reflector 1 to form a reflective thin film 16.
, and of the reflective thin film 16, as shown in FIG. The thin film 16 is removed (non-evaporated) to form the non-reflective portion 14.
A transparent top coat 17 for protecting the reflective thin film is applied on the reflective thin film 16.

In this way, the present invention removes the upper reflective thin film perpendicular to the optical axis of the reflector to form the non-reflective part 1.
4, the heat rays concentrated at the upper part b'' of the condensing part b' of the front lens 3 (indicated by the broken line in Fig. 5) are not reflected, and therefore a convection phenomenon occurs within the unit. However, the temperature of the upper part b'' does not rise significantly, so there is no risk of deformation or softening, and the advantage is that a synthetic resin front lens with good precision can be put to practical use at a low cost.

[Brief explanation of drawings]

Figure 1 is a front view of a conventional headlamp unit, Figure 2 is a front view of a conventional headlight unit.
The figure is a sectional view taken along the - line in Fig. 1, Fig. 3 is a sectional view taken along the - line in Fig. 1, Figs. 4 to 6 show an embodiment of the present invention, and Fig. 4 is a partially cutaway front view. , FIG. 5 is a sectional view taken along the - line in FIG. 4, and FIG. 6 is a cross-sectional view taken along the line A in FIG.
It is an enlarged view of the part. 1... Reflector, 13... Reflective surface, 14...
...Non-reflection part, 2...Bulb, 21...Subfilament, 3...Front lens, b'...Condensing part, b''...
...Top, f...focal point, i...optical axis line.

Claims (1)

[Scope of utility model registration request] A reflector having a substantially paraboloid-shaped reflective surface formed on its inner surface, a bulb having a subfilament located in front of the focal point of the reflector, and a front lens made of synthetic resin disposed on the front surface of the reflector. In the headlamp unit in which a reflective thin film is formed on the inner surface of the reflector by metal vapor deposition via an undercoat to form a reflective surface, the upper reflective thin film in a direction perpendicular to the optical axis of the reflector is removed. A headlight unit characterized by having a non-reflective part.