Many people have a vague notion that patents in a field undergoing
rapid development are inherently susceptible to early obsolescence.
Although many such patents will in fact become obsolete before
they expire, other such patents may retain commercial value despite
technical developments in the field.
There is a distinction between obsolescence of a product embodying
an invention and obsolescence of a patent claim
defining the invention. Although an embodiment of an invention
wholly depends upon contemporaneous technology, a patent claim
defining the invention may be relatively abstract and need not
be limited to contemporaneous technology. For example, a patent claim for the first telephone
reads:
. . . transmitting vocal or other sounds telegraphically . . . by causing electrical undulations, similar
in form to the vibrations of the air accompanying the said vocal
or other sounds . . .
Communication technology has advanced considerably in the
more than 100 years since the telephone was invented. Now, in
the field of modern technology, of course the first implementation
of the telephone would not be a viable product. The old patent
claim recited above, however, may read on any telephone, including
modern telephones employing computer, wireless, or satellite
technologies.
