Display device comprising a deflection unit
AssigneeKoninklijke Philips Electronics N.V.
InventorMichiel Harjon Wassink
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Abstract
A color display device comprising a cathode ray tube and a deflection unit is described. The display device includes compensation coils for correcting a raster distortion in the raster displayed on the screen and means for providing correction currents through the correction coils. The ratio between the correction current I24 and the vertical deflection current I21 is higher at half vertical deflection than at full vertical deflection.
Claims3
A color display device comprising a cathode ray tube, means for generating at least one electron beam (7,8,9), a display screen (10), and a deflection unit (11) for generating deflection fields for deflecting the at least one electron beam (7,8,9) across the display screen (10), and magnetic field-generating means (24,27) at or near a display screen-facing end of the deflection unit (11) to reduce raster distortions, the magnetic field-generating means (24,27) comprising correction coils (24) and means (27) for supplying said correction coils, in operation, with a correction current (I24), the ratio (I21/I24) between the correction current(I24) and the vertical deflection current(I21) being a function of the vertical deflection and being less for full vertical deflection (N or S) than for half vertical deflection (0.5 N or 0.5 S).
Dependencies are inferred from the claim text.