Designing The Zero-DAF Electron Gun For Super Slim CRT

In order to achieve mass production in super slim CRT (cathode ray tube) for family used TV sets, a brand new electron gun uses the technology of zero-DAF (zero dynamic astigmatism focus) is designed. Based on numbers of simulations, experiments and measurements, the CO8(D-line)guns which are specially designed for super slim applications become more and more successful. Introducing the concept of super slim electron beam and some extra improvements on the DY (deflection yoke) and the shadow mask, almost the same performance on image sharpness of the super slim CRT can be found compared with conventional CRT for equal screen diagonal size. Meanwhile, with zero-DAF technology, the D-line guns are simpler and with fewer grids compared with normal DAF guns to make a cost down. At present, the whole depth of the sample super slim CRT has been decreased lower than 35 cm, 25 cm or even slimmer for the tentative ones, which is comparable to the LCD (liquid crystal displays).In this paper, the operation principles of the CRT and the electron gun are discussed firstly, and then the factors which influence the image quality of the CRT, the geometry of the D-line guns and the concept of the zero-DAF are presented. In the main pages, the procedure of the gun's simulations, experiments, and measurements are discussed in detail. Furthermore, some prospects and advices are given in the end on how to design a CRT with an even slimmer outlook and better image quality in the near future.