摘要 |
<p>Reference beam deflection command values are assigned to respective pinholes at two diametrically opposite corners of a cathode ray screen. The pinholes sense actual beam position by transmitting light via respective fiberoptic cables to a detector arrangement remote from the electrostatic fields at the screen. Command values corresponding to actual beam alignment with the pinholes are determined and compared to the preselected reference beam deflection values, to produce corrections required to compensate for image scaling and/or center drift errors. With stroke type image generation, special beam search patterns are generated in the vicinity of the pinholes to activate the detector arrangement.</p> |