Thermal deformation analysis of the shadow mask and prediction of beam landing shifts for CRT using finite element method

摘要

Thermal deformation of the mask frame assembly is analyzed by using a general-purpose finite element method (FEM) software ANSYS, and ultimately the beam landing shifts for a 15" cathode ray tube (CRT) is predicted. Measures are taken to make the analysis more realistic and applicable. Firstly, the shadow mask, a thin perforated membrane structure, is modeled as a shell without slits. This is realized by homogenization of the shadow mask and the effective thermal conductivity and the effective elastic modulus are calculated. Secondly, all parts inside the CRT are modeled and transient thermal analysis of these components is performed. The beam landing shifts are derived from the following thermal deformation analysis of the shadow mask. In particular, prebending of the bimetal support spring as well as the connection of the spring to the panel are properly treated. The present FEM procedure is applicable for the thermal deformation design of a shadow mask and for design optimization in developing prototypes of CRT. (C) 2004 Elsevier Ltd. All rights reserved.