73745471
Aug 11, 1988
Apr 25, 1989
APPARATUS FOR RECORDING, TRANSMITTING OR REPRODUCING SOUND OR IMAGES, NAMELY, ELECTRONICALLY-OPERATED DOOR LOCK RELEASES AND INTERCOM SYSTEMS COMPRISING PICTURE AND VOICE TRANSMITTERS AND RECEIVERS, ELECTRONIC AUDIO AND VIDEO ENTRY PHONES, INTERNAL TELEPHONE HANDSETS AND AMPLIFIERS AND POWER SUPPLIES AND ANTENNAS FOR USE THEREWITH
Electrical and Scientific Apparatus