JPS6230242Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an improvement in the structure of a small light bulb housed in a lamp body of an automobile headlamp.

[Technical background of the invention and its problems]

In recent years, with the development of expressways and the increase in automobile traffic, there has been a need to improve the central luminous intensity and optimize the light distribution characteristics of automobile headlamps. Headlights containing small halogen bulbs have become widely used. However, since the glass bulb of the halogen-containing light bulb is small and reaches high temperatures, hard glass is used as the bulb glass, and therefore a crushing sealing method called a pinch seal is used for sealing.

However, when a bulb is pinched in the pinch sealing process during light bulb manufacturing, the glass wall thickness distribution, heating temperature distribution, blowing conditions, etc. are not uniform near the pinch seal area where the diameter is reduced from the outside diameter of the bulb, and in the pinch seal area. The thickness of the rear glass is not uniform and tends to create unevenness, and light that passes through these areas is diffused.

When such a small light bulb is incorporated into a headlight, the light emitted from the light bulb's filament is diffused in an undesired direction, making it difficult for the light reflected by the reflector to become an effective parallel beam. . The central luminous intensity of automobile headlights decreases, and the desired light distribution characteristics are not achieved, such as the undesirable upward light emitted by headlights, resulting in decreased visibility and increased glare toward oncoming vehicles. There were some drawbacks, such as:

[Purpose of invention]

The present invention was developed to solve the above-mentioned drawbacks, and it provides an automobile headlamp with improved light distribution characteristics by making simple changes to the structure of the small light bulb housed in the automobile headlamp. The purpose is to provide.

[Summary of the idea]

The present invention is an automobile headlamp characterized by having a light-absorbing heat-resistant coating coated on the outer surface of the small light bulb near the pinch seal part, which is housed in a light body made of a polymerized bowl-shaped reflector and lens. be.

The details of the invention will be explained below with reference to an illustrated embodiment.

In the figure, reference numeral 2 denotes a bowl-shaped reflector made of glass, synthetic resin, metal, etc., and the inner surface of the reflector is coated with a reflective film 1 made of vapor-deposited aluminum or the like.
is formed. Further, 4 is a small halogen-containing light bulb having a pinch seal portion 3, and this light bulb 4 has a filament 9 located at or near the focal point of a reflector 2 consisting of a paraboloid of revolution or a rotating inertial circle, and an outer conductor 6 as a reflector. It is fixed in a ferrule 5 provided on the back side of 2 with a brazing material or the like. Reference numeral 10 denotes a glass bulb of a small light bulb 4, and a light-absorbing heat-resistant coating 11 made of black cobalt oxide is adhered to the pinch seal portion 3 and the outer surface near the pinch seal portion. Further, a lens 8 is superimposed on the front opening 7 of the reflector 2 by means of sealing, adhesion, pressure bonding, etc. to form a lamp body 12.

As described above, the small light bulb 4 with the light-absorbing heat-resistant coating 11 coated on the pinch seal portion 3 and the vicinity of the pinch seal portion is undesirable even when attached to a reflector because no light is emitted from the portion where the coating 11 is formed. Light irradiation in the direction disappeared.

Note that the present invention is not limited to the above-mentioned embodiments; for example, the light-absorbing heat-resistant coating is applied not only to the pinch seal part and the glass bulb as in the embodiment, but also to a part of the pinch seal part, The curved boundary between the pinch seal portion and the glass bulb alone may have a sufficient effect depending on how the pinch seal is deformed. Further, the material of the light-absorbing heat-resistant coating is not limited to cobalt oxide as shown in the embodiments, but materials such as manganese oxide can be used. This coating is preferably heat resistant since the temperature of the glass bulb of a small light bulb is high. Furthermore, although the present invention is not limited to halogen-containing light bulbs, especially in halogen-filled light bulbs, the coating is formed at or near the pinch seal portion, which is relatively far from the filament. It was also possible to achieve the effect that the temperature rose and the halogen cycle was carried out in a sufficiently stable manner.

Furthermore, the reflector of the present invention has a bowl-like shape, such as a circle, an ellipse, or a square, when viewed from the front opening side, and a reflective film is formed on all or most of its inner surface. Can be applied to things.

[Effect of idea]

As described in detail above, the present invention provides a headlamp in which a small light bulb is housed in a lamp body made by polymerizing a bowl-shaped reflector and a lens, in which a light-absorbing heat-resistant coating is applied to the outer surface of the small light bulb near the pinch seal part. The coating completely blocks the diffusion of light emitted from the filament due to undesirable unevenness or uneven wall thickness that occurs on the glass bulb during the pinch sealing process during light bulb manufacturing. The bowl-shaped reflector is designed so that only the light from the normally smooth surface around the entire circumference of the light bulb is emitted without loss, and the reflector emits only the parallel light necessary for the headlight.

Therefore, as an automobile headlamp, undesirable diffused light is completely prevented from reaching the reflector, and the light distribution characteristics are excellent, with no upward scattered light.
This has the effect of providing an automobile headlamp with improved visibility and less glare to oncoming vehicles.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway front view showing an embodiment of the automobile headlamp of the present invention, and FIG. 2 is an enlarged front view of the small light bulb shown in FIG. 1. 2...Reflector, 3...Pinch seal part, 4
...Small light bulb, 8...Lens, 11...Light-absorbing heat-resistant coating, 12...Lamp body.

Claims (1)

[Scope of utility model registration request] A small light bulb having a pinch seal part is housed in a lamp body in which a lens is polymerized in the opening of a bowl-shaped reflector, and the small light bulb has a light-absorbing heat-resistant coating coated on the outer surface near the pinch seal part. An automobile headlamp characterized by: