DIGITAL DEVICE FOR CORRECTING THE IMAGE FORMED ON THE SCREEN OF A CATHODE RAY TUBE

摘要

Device for correcting the line and/or frame fields of a deflector for cathode ray tube comprising - a current sensor (1) for evaluating the value of a line current II - a series of comparators (40 to 4N) intended to compare the value of the line current II with reference values - a current sensor (2) for evaluating the value of the frame current It - an analogue/digital converter (31) for converting the analogue value of the frame current - a programmed correction memory (50) which is addressed by the output signals from the comparators and from the analogue/digital converter so as to deliver to at least one digital/analogue converter (70, 71... 7N), data (60, 61, ...6N) which are dependent on the addressing signals - a low-pass filter (80, 81, ... 8N) for filtering the output of the digital/analogue converter - at least one correction coil (100, 101,...10N) for correcting the deflection fields of the deflector, and generating a correction field as a function of the output value from the low-pass filter.