Light-sensitive glow discharge apparatus

880,574. Discharge lamps. INTERNATIONAL BUSINESS MACHINES CORPORATION. Sept. 26, 1958 [Sept. 27, 1957; Oct. 11, 1957], No. 30835/58. Class 39(1) [Also in Groups XIX and XL(b)] In a glow discharge diode matrix for use in electronic switching arrangements (see Groups XIX and XL(b)), the structure comprises three slabs of insulating material (glass) 55, 56 and 57 assembled in a sandwich type construction. A plurality of discaid or annular cathodes 58 are deposited on the inner surface of slab 55 and connected in rams to conductors 59-62. On the inner surface of slab 57 a similar number of annular anodes 63 are deposited and connected in columns to conductors 64-67. Each anode on slab 57 is positioned opposite a cathode on slab 55. Centre slab 56 is opaque and has a plurality of holes extending between each anode and associated cathode. A peripheral ridge 69 maintains a slight spacing between slabs 56 and 57 when the slabs are assembled. The enclosed space is evacuated and filled with neon and a small amount of argon at low pressure.