| 摘要 |
1,133,868. Colour television tubes. RADIO COPORATION OF AMERICA. 2 June, 1966 [7 Jan., 1966], No. 24701/66. Heading H1D. [Also in Division G1]. A shadow mask electrode is assembled with respect to a cathode ray tube faceplate by measuring the spacing between the faceplate and the mask at a plurality of points distributed over the faceplate, adjusting the relative positions of the faceplate and mask until each of the measured spacings departs from the desired spacing by less than the permitted tolerance, and maintaining the faceplate and mask in that relative position by detachably fixing the mask to the faceplate. The method permits the mating of a higher proportion of mask-faceplate pairs than does the use of a fixed spacer member. The mask electrode and faceplate are mounted in a machine (Figs. 1 to 4, not shown), which permits the faceplate to be both raised against the fixed mask, and also tilted about two perpendicular axes lying in its plane - and preferably coincident with the diagonals of the faceplate, if the latter is rectangular. Before raising the faceplate, a spacer assembly is placed thereon, consisting of a thin sheet 107, Fig. 6, of fibre glass or plastics material, shaped substantially to conform to the contour of the faceplate, and having five air-operated distance gauges 109 (see Division G1) flexibly attached one to each corner and one at the centre, the gauges being connected to a liquid column pressure meter calibrated to indicate the spacings sensed by the gauges. After adjustment of the faceplate, by tilting and vertical movement, to produce spacings all lying within the permitted tolerance, the mask is detachably secured to the faceplate by welding support springs to the mask which is held by the engagement of studs on the faceplate within corresponding apertures formed one at the end of each spring. Prior to the welding, the faceplate may be displaced bodily from the mask by a predetermined distance sufficient to compensate for the change of spacing which normally results from the thermal effects of welding. |
