CRT glass screen mfg. process - involves suction drawing into pot-shaped mould that has evacuated slot around inner periphery

摘要

The glass screen for a CRT is made by heating a flat glass plate to softening point and then drawing it down into a pot-shaped mould by evacuation to give the final pot-shaped mould by evacuation to give the final pot-shaped screen for the CRT. The region of low pressure inside the mould is generated in a circular slot (4) around the inside periphery of the pot-shaped mould. This slot is formed by the walls of the mould and its internal raised part (9) whose top surface forms the moulding surface for the 'base' of the screen.