Raster distortion avoidance arrangement
AssigneeRCA Thomson Licensing Corporation
InventorPeter E. Haferl
Life of this patent
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Abstract
Organ pipes distortions, caused by parasitic ringing in a horizontal deflection current are suppressed by forming a current pulse in a current injection arrangement. The current pulse is coupled to a junction terminal between a terminal of the horizontal deflection winding where a high retrace pulse voltage is developed and a low voltage terminal of a linearity correction inductance. A high voltage terminal of the linearity correction inductance is coupled to a horizontal output transistor. The current pulse begins prior to the end of retrace and ends during the trace interval.
Claims15
A video display deflection apparatus comprising:
- a deflection winding;
- a retrace capacitance coupled to said deflection winding to form a retrace resonant circuit;
- first switching means coupled to said deflection winding for producing a deflection current and a retrace pulse voltage therein;
- an inductance coupled in a current path of said deflection current between said deflection winding and said first switching means;
- means for generating a pulse of current that is coupled to said inductance and to said deflection winding via a junction terminal, that is in said current path between said inductance and said deflection winding, said pulse of current having both a beginning time and an end time in a vicinity of an instant when said retrace pulse voltage ceases, said pulse of current producing a decrease in a current that flows in said inductance, during a beginning portion of a trace interval.
A video display deflection apparatus, comprising:
- a deflection winding;
- a retrace capacitance coupled to said deflection winding to form a retrace resonant circuit;
- first switching means coupled to said deflection winding for generating a resonant retrace pulse voltage at a first terminal of said deflection winding and a deflection current in said deflection winding, said retrace pulse voltage producing a capacitive current in an inter-winding capacitance of said deflection winding that decreases when said retrace pulse voltage ceases, said decrease in said capacitive current producing an increase in a current that flows in said first terminal;
- and
- means coupled to said terminal for generating a current pulse in a current path that includes said terminal, when said retrace pulse ceases, in a manner to reduce a rate of said increase of said first terminal current such that following a beginning portion of a trace interval, said current pulse ceases.
A video display deflection apparatus, comprising:
- a deflection winding;
- a retrace capacitance coupled to said deflection winding to form a retrace resonant circuit;
- first switching means coupled to said deflection winding for producing a deflection current and a retrace pulse therein;
- an inductance coupled in a current path of said deflection current between said deflection winding and said first switching means;
- a series arrangement of a resistor and a second capacitor for producing from said retrace pulse voltage a current that charges said second capacitor such that said resistor limits said charging current;
- and
- second switching means coupled to said second capacitor for generating a pulse of current from the charge in said second capacitor in a manner that bypasses said resistor so as to prevent said resistor from limiting said current pulse, said current pulse being coupled to said inductance and to said deflection winding via a junction terminal that is in said current path between said inductance and said deflection winding.
Dependencies are inferred from the claim text.