Stacked light-mixing LED

Details Stacked light-mixing LED Stacked light-mixing LED

2000-09-08

2003-02-25

Patel, Ashok (Department: 2879)

Electric lamp and discharge devices

With luminescent solid or liquid material

Solid-state type

C313S512000

Reexamination Certificate

active

06525464

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an LED and, more particularly, to an LED that provides better light-mixing effect by stacking chips.
2. Description of Related Art
A conventional LED utilizes blue light to excite a fluorochrome material to cause the fluorochrome material to emit yellow light, which is mixed with the blue light to generate white light. Alternatively, the conventional LED utilizes a parallel blue chip and yellow chip (shown in FIG.
5
and
FIG. 6
) to emit the white light. The blue chip
93
and the yellow chip
94
are stuck on the conductive supporting frame
91
of the LED
9
by conductive paste
92
, and the electrical power supplied by the conductive frame
91
is used to make the blue chip
93
emit the blue light and the yellow chip
94
to emit yellow light. By controlling the electrical current and voltage, the LED
9
with the characteristic of a single wavelength can make the blue light and yellow light diffuse and mix to provide white light.
However, the LED
9
, which has the parallel chip
93
and chip
94
, has a problem in mixing the lights, and also has a color fleck problem. The reason is that the distance D between the parallel chip
93
and chip
94
causes the LED to display different colors on two sides of the LED, the blue LED chip
93
side showing blue light and the yellow due to difficulties in processing that the distance D between the chip
93
and the chip
94
cannot be made closer or the chips will be short-circuited and leaking current problems will result, which causes the additional problem of decreasing the yield.
SUMMARY OF THE INVENTION
The main objective of the present invention is to solve the aforesaid problems and to provide a stacked, light-mixing LED in which by mixing two lights with different wavelengths in the visible light spectrum area, excited and emitted from a first chip and a second chip, and by controlling electrical current and voltage, the two lights excited from the first chip and the second chip can be mixed into another wavelength of light in the visible light spectrum area, such as the white light, to provide a better symmetric light-mixing effect and avoid a visible color difference.
Another objective of the present invention is to provide a stacked, light-mixing LED without the problem of short circuits and leaking current by stacking the first chip and the second chip.


REFERENCES:
patent: 5393993 (1995-02-01), Edmond et al.
patent: 5623181 (1997-04-01), Suehiro et al.
patent: 5707745 (1998-01-01), Forrest et al.
patent: 5998925 (1999-12-01), Shimizu et al.
patent: 6346771 (2002-02-01), Salam
patent: 2001/0022495 (2001-09-01), Salam
patent: 2002/0057567 (2002-05-01), Chen
patent: 106555 (1998-05-01), None

Affiliated with

Also associated with

Rating

Stacked light-mixing LED does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Stacked light-mixing LED, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Stacked light-mixing LED will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3165839