1
Enock Joseph Guy: Improvements in or relating to electro-acoustic transducers. Decca, November 2, 2006: GB1234767-A (9 worldwide citation)

1,234,767. Capacitor transducers. DECCA Ltd. 26 Nov., 1968 [18 Sept., 1967], No. 42420/67. Heading H4J. In a capacitor transducer, e.g. microphone or loud-speaker, a rigid, perforated conductive plate 14 is spaced from a diaphragm comprising a sheet 10 of non-conductive dielectric material having a ...


2
Enock Joseph Guy: Improvements in or relating to electroacoustic transducing apparatus. Decca, April 2, 1969: GB1147423-A (4 worldwide citation)

1,147,423. Electrostatic loud - speakers. DECCA Ltd. 24 May, 1967 [25 May, 1966], No. 23443/66. Heading H4J. An electrostatic loud-speaker employing an electret has a source of energizing current arranged to apply to the electret an electric field of sufficient magnitude and duration to ensure the n ...