PURPOSE: To increase the convergence performance dispersion allowable value of a product and to improve productivity by automatically correcting misconvergence at an entire screen with the drive of an electromagnetic CY coil part by an electromagnetic CY driving power source.

CONSTITUTION: By H and V synchronous signals 11 from an input signal processing/synchronizing circuit 9, a scanning position detection part 7 generates screen scanning timing signals and outputs a screen scanning position to a memory cell 6. The screen scanning position is subdivided into blocks and outputted to addresses inside the cell 6 stored with the convergence correction information of the timing for scanning the respective blocks beforehand. The cell 6 outputs the correction information corresponding to the specified address to a D/A converter 5 to be analog-converted and outputted to an electromagnetic CY driving power source part 4 as a control voltage. The power source part 4 generates a magnetic field by driving an electromagnetic CY coil 3, controls the orbits of electron beams corresponding to three colors and automatically corrects the misconvergence generally.