Cathode ray tube processing
AssigneeU.S. Philips Corporation
InventorsDavid J. Patrickson, John D. Webster, Edward Schwartz
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Abstract
A method of processing regunned cathode ray tubes by exhausting/baking the tube, aging the cathode, and only then flashing the getter. Finally, the gettered tube is high voltage conditioned before testing.
Claims3
A method of processing a cathode ray tube which has been previously gettered by the flashing of a barium containing material therein and, thus, has a barium film on portions of its internal surface, and which has been regunned by removing the original gun from the neck of the tube and then sealing therein a replacement gun having a cathode, a plurality of mutually spaced grid electrodes and a barium-containing getter extending from one of the electrodes, said method including baking and exhausting the tube to a pre-flash vacuum, then sealing the evacuated tube to form a closed vessel, and the improvement comprising the steps of:
- aging the tube including heating the cathode and drawing a current therefrom to at least one grid electrode, so that the electron emission from the cathode is stabilized, and then
- gettering the aged tube by flashing the barium-containing getter therein, whereby the occurrence of a dark-centered cathode is substantially avoided.
Dependencies are inferred from the claim text.