Abelman, Frayne, Rezac & Schwab
Combination ionization and photoelectric smoke detector
 A combination type smoke detector comprising a light scattering smoke detector and an ionization smoke detector in which a labyrinth structure dark chamber for the light scattering smoke detector is made of an electroconductive plastic material and functions as the outer electrode of the ionization smoke detector is disclosed. Members of the ionization smoke detector and the light emitter and the light sensing element for the light scattering smoke detector are arranged so that the light emitted from the light source and reflected by said members and the lamina members does not enter the light-sensing element. 
Nittan Company, Limited
G G G G
G08B G08B G08B G08B
inventional inventional inventional inventional
Masayoshi Kohei Takao Seiji
Saito Yamada Fujisawa Tsubouchi