Long-lasting metal halide discharge lamp

Details Long-lasting metal halide discharge lamp Long-lasting metal halide discharge lamp

1998-12-08

2001-04-17

Patel, Nimeshkumar D. (Department: 2879)

Electric lamp and discharge devices

With gas or vapor

With particular gas or vapor

C313S571000

Reexamination Certificate

active

06218781

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a metal halide discharge lamp In particular, the present invention relates to a metal halide discharge lamp for use in the field of effect lighting, that is, with color temperatures above the so-called “daylight” temperature of 4200 K and with medium arc lengths.
2. Background Information
Metal halide discharge lamps are preferably used for lighting fixtures in architectural and effect lighting, and thus are particularly for accent lighting of defined areas, such as in houses and apartments, in galleries, or for social or professional occasions, to provide emphasis and lighting that is brighter than ambient light. The demands made in this field, in terms of the optical properties of the light, and in particular the location where the light is generated, the luminous flux referred to the power of the lamp, and the color temperature, can be classified somewhere between the needs of general lighting and specialized requirements, such as for projection purposes.
Although somewhat more stringent demands in terms of the aforementioned technical characteristics are made of such lamps, compared with the general lighting field, still in the field of effect lighting it is quite important to strive for the longest possible service life, so as to lessen the cost of replacement bulbs and the labor of replacing them, as well as to make the lamps reliable and maintenance-free.
Good color reproduction and the correct color temperature are important goals as well.
SUMMARY OF THE INVENTION
An object of the invention, is to provide a metal halide discharge lamp having a lengthened preamble to claim
1
, is to lengthen the service life.
This object is attained by a metal halide discharge lamp having a color temperature of over 4800° K. and comprising a bulb and a fill disposed therein, the fill comprising an ignition gas, mercury, a halogen, lithium, indium, thallium and tin, and is devoid of a rare earth element.
As its point of departure, the invention first assumes that devitrification,—that is, the progressive crystallization of the bulb of a metal halide discharge lamp,—is an essential determinant of its service life. The invention therefore contemplates a fill without any rare earth element, because the rare earth elements have proven to be a substantial cause of the devitrification phenomenon as the lamp increases in age.
Because the invention dispenses with a rare earth element, an additional advantageous effect,—in addition to the increase in service life because there is less devitrification, is a decreased tendency to blackening of the inside wall of the lamp bulb. In view of the fundamental object stated above, this effect can be exploited to reduce the wall load. To this end, either the bulb can be larger, for a specified electrical power consumption of the lamp, or for a specified bulb size, the power consumption can be reduced. Until now, this was not conventionally possible except at the cost of the blackening problems that then ensued. The low wall load additionally lessens the tendency to devitrification, and thus, beyond the already-described effect of dispensing with rare earth elements, improves devitrification and hence improves the service life of the lamp.


REFERENCES:
patent: 5138229 (1992-08-01), Honda et al.
patent: 5323085 (1994-06-01), Genz
patent: 5691601 (1997-11-01), Frey et al.
patent: 492 205 (1992-07-01), None
Derwent AbstractsAN 97-032850, XP-002079972, Database WPI, Section CH, Week 9703, Apr. 20, 1996, of RU 2058620C.
Patent Abstracts of Japan, vol. 017, No. 340, Jun. 28, 1993, of JP 050047348, Toshiba Lighting & Technol. Corp., Feb. 26, 1993.
Patent Abstracts of Japan, vol. 004, No. 083, Jun. 14, 1998, of JP 55050567, Toshiba Corp., Apr. 12, 1980.

Affiliated with

Also associated with

Rating

Long-lasting metal halide discharge lamp does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Long-lasting metal halide discharge lamp, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Long-lasting metal halide discharge lamp will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2501040