Improvements relating to pick-up tubes having photo-conductive or semi-conductive targets

摘要

1,027,841. Photo-conductive devices; television pick-up tubes. ELECTRIC & MUSICAL INDUSTRIES Ltd. Jan. 31, 1963 [Feb. 1, 1962], No. 3895/62. Headings H1D and H1K. A pick-up tube comprises a radiation sensitive target comprising a first semi-conductor layer on a conductive film and a second layer on the first, of amorphous material including selenium and arsenic. The Figure shows a vidicon type tube, in which the target consists of a transparent conductive film 4 on the end of the glass tube 1, a thin (0À3 Á) deposited layer 5 of selenium and a deposited layer 6 (0À3 to 3 Á thick) of arsenic and selenium. The proportion of arsenic may vary between 3% and 36% by weight. A smaller amount of arsenic (5 to 10%) or other impurity may be provided in the first layer 5.