Convergence correction circuit.

摘要

A convergence correction circuit according to the present invention has a PLL loop including a programmable counter (3). The programmable counter has programmable count start and end points. The output of the programmable counter is supplied to a memory (6) storing convergence distortion correcting data therein. As the horizontal screen size is increased, a value closer to the lower limit 0 of the start point as compared with that taken when the horizontal size is small is set as the count start point of the programmable counter, and a value closer to the upper limit (2<7>-1) of the end point as compared with that taken when the horizontal size is small is set as the count end point. In accordance with the horizontal screen size, therefore, the count start and end points of the programmable counter are changed. Even if the horizontal screen size is changed, correct convergence correction can thus be performed.