(under subclass 109) Subject matter wherein an audio signal, as the information signal, is directly modulated onto a light beam.
(1) Note. This subclass includes direct modulation of the light beam by a sound responsive mechanical device (e.g., a diaphragm).
(2) Note. The optical telephones of this subclass require the use of an optical carrier for communication information.
SEE OR SEARCH CLASS
379, Telephonic Communications,
56.1+, for a light wave link for speech or a paging signal. These would include optical telephones where connection is made through a telephone operator or exchange.
