Masking device for a colour flat screen cathode ray tube comprising a supporting frame for planar mask and planar mask

摘要

A device for masking a flat screen color monitor has a mask mounted within and tensioned at ambient temperature by a support. The support is an iron nickel alloy with a thermal expansion coefficient ≤ 5 x 10<-6>/K between 20 - 150 degrees C and an elastic limit Rp0.2 at 20 degrees C ≥ 700 MPa. Independent claims are included for the following: (a) Methods of manufacturing the above device including hardening of the screen at 400 - 800 degrees C. (b) Methods of manufacturing the above device including de-tensioning the screen at 400 - 600 degrees C.