GB1265888A - - Google Patents

Abstract

1,265,888. Electrode processing. PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd. 11 July, 1969 [16 July, 1968], No. 35057/69. Heading H1D. A method of manufacturing an electron tube whose envelope contains a photosensitive layer comprises exhausting a space containing the tube envelope, a first support and a spare support for the photosensitive layer, both being independently movable, and a vaporizer, forming the photosensitive layer on the first support by deposition from the vaporizer whilst checking the characteristics of the layer and, in the event of a defect being found in the layer, replacing the first support by the spare one, forming a photosensitive layer thereon and subsequently sealing the completed tube in the same vacuum. The photosensitive layer may be formed on an envelope portion of the tube which is sealed by cold welding under pressure within the vacuum to the remainder of the tube envelope to form the completed tube. The first and spare supports may be symmetrically mounted with respect to the welding press, vaporizer and checking device, Figs. 1 and 2 (not shown), such that each is independently movable, e.g. by rotation about a supporting shaft, from a first position to a second position in correspondence with both the vaporizer and checking position and on to a third position to co-operate with the remainder of the tube supported on the movable portion of the press.