H
ELECTRICITY
H
ELECTRICITY
H04
ELECTRIC COMMUNICATION TECHNIQUE
H04
ELECTRIC COMMUNICATION TECHNIQUE
H04N
PICTORIAL COMMUNICATION, e.g. TELEVISION
H04N
PICTORIAL COMMUNICATION, e.g. TELEVISION
7/00
Television systems
7/00
Television systems
H04N7/14
Systems for two-way working
H04N7/14
Systems for two-way working
H04N7/141
between two video terminals, e.g. videophone
H04N7/141
between two video terminals, e.g. videophone