Led lamp having a prismatically-cut modifier

Details Led lamp having a prismatically-cut modifier Led lamp having a prismatically-cut modifier

1999-08-11

2001-10-02

O'Shea, Sandra (Department: 2875)

Illumination

Light source and modifier

Including reflector

C362S268000, C362S297000, C362S311040, C362S317000, C362S339000, C362S307000

Reexamination Certificate

active

06296376

ABSTRACT:

This invention claims the benefit of Japanese Patent Application No. Hei 10-228038, filed on Aug. 12, 1998, which are incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an LED lamp employing an LED chip that is a semiconductor light emitting device as a light source specifically provided with the object of providing LED lamp configuration applicable to uses in vehicle signal lights etc. demanding area-lighting with uniform brightness.
2. Description of Related Art
An example configuration of a related type of LED lamp
90
is shown in FIG.
6
. An LED chip
91
is mounted within a horn section
92
a
provided in order to obtain reflection at a lead frame
92
, light is reflected in a prescribed direction and the LED chip
91
is covered by a molded case
93
of transparent resin.
The object of the molded case
93
is to provide resistance to moisture and to provide light from the LED chip
91
including light reflected at the horn section
92
a
at an appropriate illuminating angle. A top part
93
a
of the molded case
93
therefore forms a convex lens and an illuminating angle &ggr; of, for example, 30 to 40 degrees is provided.
In the related LED lamp
90
of the above configuration, the LED chip
91
is embedded within the molded case
93
. The LED chip
91
is therefore subjected to stress due to the difference in the thermal expansion coefficients of the LED chip
91
and the molded case
93
, and it is therefore extremely important to make the diameter of the molded case
93
approximately 5 mm or less.
When the LED lamp
90
is used as a light source for a vehicle light such as a rear light, a plurality of LED lamps
90
are adopted. However, the light emitting area of one LED lamp
90
is small and the illuminating angle is narrow. There is also a strong tendency for the luminance distribution to focus itself about a central line. It is therefore preferable to arrange a plurality of LED lamps
90
at a narrow pitch in order to provide a uniform intensity of illumination at the outer lens surface of a vehicle light.
However, if LED lamps are arranged in a small pitch at the rear surface of an outer lens of a vehicle light having a prescribed area, the number of LED lamps
90
required increases, which causes increasing costs. Further, when the pitch of the LED lamps
90
is narrow, the temperature within a light housing for the vehicle light increases, and the luminance of the LED lamps
90
decreases.
Further, there is a tendency of oversimplification for the vehicle lamp comprising the conventional LED lamp
90
. Since the mold case
93
is a convex lens which must act as an optical means to obtain prescribed optical characteristics of the LED lamp
90
, it is difficult for the mold case
93
to have any complicated shape such as a combination of pentagons, although such a complicated shape is required from aesthetic appearance of the vehicle light.
It is therefore the object of the present invention to provide an LED lamp that overcomes the above problems and which is applicable to uses in vehicle signal lights etc. demanding uniform brightness.
SUMMARY OF THE INVENTION
In order to achieve the aforementioned object, the present invention provides an LED lamp comprising a first optical section and a second optical section. The first optical section is for providing light, from an LED chip provided with at least one of a concave mirror and a dome lens, at an appropriate illuminating angle. The second optical section is positioned to receive light from the first optical section via an air layer and is shaped as a lens in such a manner that a composite focal point thereof substantially coincides with the position of the LED chip. At least one surface of the second optical means is a prismatically cut surface.
In the present invention, at least one type of second optical section is provided in a manner selectable on assembly of the LED lamp.
Further, the entire shape of the second optical section when viewed from the front is of such a shape that a plurality of the shapes can be arranged close to each other.
With the present invention, the diameter of the light emitting surface can easily be enlarged from approximately 5 mm at most in the related art to approximately 15 mm, the tendency for luminance to be large at a central line is alleviated and the luminance of the outer lens surface of a vehicle light taking LED lamps as a light source is made uniform. Visibility are therefore improved, and performance are also improved.
Further, aesthetic appearance of the vehicle light is also improved, as the present invention provides the second optical means separate from the first optical means, a wide variety of design changes can be catered for by preparing a plurality of types of second optical means and then selecting which is to be used or which types are to be used in combination. Design oversimplification that often occurred in related vehicle lights taking related LED lamps as a light source can therefore be prevented.


REFERENCES:
patent: 4935665 (1990-06-01), Murata
patent: 4965488 (1990-10-01), Hihi
patent: 5093768 (1992-03-01), Ohe
patent: 5515253 (1996-05-01), Sjobom
patent: 5939996 (1999-08-01), Kniveton et al.
patent: Shou 62-269984 (1987-11-01), None
patent: Hei. 4-36588 (1992-06-01), None
patent: Hei. 4-36589 (1992-06-01), None

Affiliated with

Also associated with

Rating

Led lamp having a prismatically-cut modifier does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Led lamp having a prismatically-cut modifier, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Led lamp having a prismatically-cut modifier will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2590336