Dual length copier lamp
AssigneeGTE Products Corporation
InventorsMerle E. Morris, Lawrence M. Rice, Steven L. Meade
Life of this patent
Estimating the term…
Abstract
A tubular incandescent lamp for use in a fusing type lamp in a photocopy machine in which the lamp filament means is capable of operation at two different lengths on a selective basis as a function of the different lengths of paper that are to be reproduced by the copier. In one embodiment the filament means comprises a single linear filament with the contacts being taken at opposite ends of the filament for full length reproduction and along a predetermined length of the filament or shorter length of reproduction. In an alternate embodiment of the invention, two different length filaments are employed, each one selectively and mutually exclusively operated.
Claims18
In an incandescent lamp including a tubular quartz envelope, a coiled tungsten filament substantially centrally disposed within said envelope and extending substantially the length thereof, and first and second contact means located respectively at first and second opposing ends of said coiled tungsten filament and electrically coupled thereto, said coiled tungsten filament being energized over the substantially entire length thereof when a predetermined, first voltage is applied across said first and second contact means, the improvement comprising:
- means for de-energizing an end portion of preselected length of said coiled tungsten filament while enabling the remaining length of said filament to be energized, said de-energizing means comprising a third contact means located at said second opposing end of said coiled tungsten filament and spaced from said second contact means, said third contact means electrically coupled to said coiled tungsten filament at a point located an established distance from said second opposing end substantially equal to said preselected length of said coiled tungsten filament being de-energized, said de-energizing of said end portion of said filament and said energizing of said remaining length simultaneously occurring when a predetermined, second voltage is applied across said first and third contact means.
An incandescent lamp comprising:
- first and second tubular quartz envelopes of substantially the same length and positioned substantially parallel to each other, each of said envelopes having a first sealed end portion positioned within a first common mount member and a second sealed end portion positioned within a second common mount member;
- a first coiled tungsten filament having a first length and substantially centrally disposed within said first tubular quartz envelope;
- a second coiled tungsten filament having a second length shorter than said first length and substantially centrally disposed within said second tubular quartz envelope;
- first contact means associated with said first common mount member and electrically coupled to a first end of each of said first and second coiled tungsten filaments;
- second and third contact means associated with said second common mount member and respectively electrically coupled to a second end of said first and second coiled tungsten filaments whereby said first coiled tungsten filament will be energized when a predetermined, first voltage is applied across said first and third contact means and said second coiled tungsten filament will be energized when a predetermined, second voltage is applied across said first and second contact means.
Dependencies are inferred from the claim text.