Illumination – Light modifier – Reflector
Reexamination Certificate
1998-10-02
2001-04-03
Spyrou, Cassandra (Department: 2872)
Illumination
Light modifier
Reflector
C362S342000, C362S507000, C362S547000
Reexamination Certificate
active
06210024
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a vehicle lamp wherein a light source is fitted into a light-source fitting hole formed in a metal reflector disposed within a lamp chamber. More particularly, the invention relates to a vehicle lamp wherein a light source is fixed, by a plastic fixedly holding means, in the light-source fitting hole formed in a metal reflector.
2. Related Art
As shown in
FIG. 7
, a projection-type automobile headlamp as an example of the conventional lighting fixture of this type is provided with a light source unit integrating a substantially elliptic reflector
3
fitted with a bulb
4
as a light source, a cylindrical lens holder
5
and a projection convex lens
6
together within a lamp chamber defined by a lamp body
1
and a front cover
2
. Reference numeral Sa denotes a shade for forming a clear cut line of a low-beam.
The bulb
4
is structurally formed by integrating a bulb body
4
a
as a light source with a plastic bulb socket
4
b
, and a focusing ring
4
c
formed with mating pawls
4
c
1
in its peripheral edge portion is integrated with the outer periphery of the bulb socket
4
b
. On the other hand, a ring-like socket fixture
7
formed of synthetic resin is fixed with screws to the edge face of a cylindrical portion
3
b
forming a bulb fitting hole
3
a
in the reflector
3
and a mating groove
8
is formed so that the mating pawls
4
c
1
on the side of the bulb socket
4
b
can be brought into engagement with the mating groove by bayonet coupling between the bulb fitting hole
3
a
and the socket fixture
7
. The bulb
4
is made detachable from the bulb fitting hole
3
a
by turning the bulb
4
(the bulb socket
4
b
).
As the conventional projection-type headlamp of this type can be made compact to the extent that a smaller reflector is usable though a large quantity of light is available in comparison with a reflection-type headlamp using a parabolic reflector, the former is increasingly spotlighted and positively utilized for automobile headlamps.
However, because the reflector
3
in the aforesaid projection-type lamp is made of metal having high thermal conductivity (generally aluminum die-cast), it suffers from a problem that high temperature resulting from the generation of heat when the bulb
4
is lighted may subject to heat deformation any part of the plastic bulb socket
4
b
or plastic socket fixture
7
which is brought into contact with the reflector
3
.
SUMMARY OF THE INVENTION
In view of the foregoing problems accompanying the conventional vehicle lamp, it is an object of the present invention to provide a vehicle lamp eliminating the possibility of subjecting to thermal deformation a plastic means for fixedly holding a light source, such as a plastic bulb socket and a plastic socket fixture, in the light source fitting hole of a metal reflector.
In order to accomplish the object above, a vehicle lamp according to the present invention includes a cap-like metal reflector opening toward the front end of a lamp chamber, a light source body fixedly held in a light source fitting hole formed in the rear top portion of the reflector by plastic fixing-holding means and disposed in a predetermined position ahead of the reflector, and convection-current forming holes for restraining the reflector from being heated to high temperatures.
An air convection current is generated between the inside and outside of the reflector via the convection-current forming holes and this air convection current promotes the heat radiating action of the reflector causing warmed air inside the reflector to flow out through the convection-current forming holes and further preventing heat from accumulating inside the reflector thereby restraining the reflector from heating to high temperatures.
Furthermore, as the light receiving area of the reflector is reduced by what corresponds to the convection-current forming holes, the heat transmitted to the reflector due to the direct rays of light and the radiant heat are also reduced and the reflector is restrained from being heated up to high temperatures.
Further, according to the present invention, the vehicle lamp that are provided with the convection-current forming holes is formed on the non-effective reflective surface of the reflector.
The light distribution of the vehicle lamp is obtained from the light reflected from the effective reflective surface of the reflector, and as the light reflected from the non-effective reflective surface of the reflector hardly contributes to the light distribution of the vehicle lamp, the light distribution of the vehicle lamp remains unaffected even though the convection-current forming holes are provided in the non-effective reflective surface.
Furthermore, according to the present invention, the vehicle lamp is such that the convection-current forming holes respectively include a plurality of laterally-long slits formed at predetermined intervals in the direction of an optical axis extending in a direction substantially perpendicular to the optical axis of the reflector; and vertical wall-like heat-radiating fins extending along the respective slits are provided between the adjoining slits.
The whole open area of the convection-current forming holes is increased by forming the convection-current forming holes with a plurality of rectangular slits. The heat radiating action of the reflector is promoted by making the convection current active and besides the vertical wall-like heat-radiating fins extending along the respective slits.
According to the present invention, the vehicle lamp is such that each of the heat-radiating fins is tilted in a direction substantially perpendicular to the direction of direct rays of light from the light source body in order to have the light reflected backward.
Since the direct rays of light emitting from the light source body and passed through the convection-current forming holes are shaded by the heat-radiating fins, a wall forming the plastic lamp chamber is never irradiated with the direct rays of light. Since the direct rays of light from the light source body are reflected backward by the heat-radiating fins, moreover, the intensity of light leaking from the vehicle lamp forward is extremely low and the light distribution of the vehicle lamp remains substantially unaffected.
According to the present invention, the vehicle lamp is such that the convection-current forming holes are provided in the upper and lower portions of the reflector opposite to each other.
The air warmed in the lamp chamber is made to flow out of the reflector smoothly through the upper convection-current forming holes, whereas the air outside the reflector is made to flow into the reflector smoothly through the lower convection-current forming holes.
According to the present invention, the vehicle lamp is such that the reflector is integrated with a projection lens via a cylindrical lens holder, so that region ranging from the inside of the lens holder up to the front of the reflector is substantially closed.
The air convection current generated between the inside and outside of the reflector via the convection-current forming holes prevents heat from being accumulated inside the reflector kept substantially closed.
A vehicle lamp according to the present invention includes a cup-like metal reflector opening toward the front end of a lamp chamber and a light source body fixedly held in a light source fitting hole provided in the rear top portion of the reflector by plastic fixing-holding means and disposed in a predetermined position ahead of the reflector. Additionally, heat-radiating fins for restraining the reflector from being heated to high temperatures are provided on the outside of the reflector.
Since the outer surface area of the reflector is increased to an extent equivalent to the area of the heat-radiating fins, the heat radiating effect is improved. In other words, the heat radiating action of the reflector is promoted and the reflector is restrained from being heated to high temperatur
Koito Manufacturing Co. Ltd.
Spyrou Cassandra
Sughrue Mion Zinn Macpeak & Seas, PLLC
Winstedt Jennifer
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