A projection display comprises three cathode ray tubes each having a deflection yoke and convergence yoke and each tube generating a raster for projection. One of the three cathode ray tubes has the convergence yoke coupled for current flow in a direction opposite to that of the other two convergence yokes. An amplifier is respectively coupled to each convergence yoke for convergence correction of each raster. A convergence circuit supplies correction signal values that are coupled to each respective amplifier such that convergence correction by the other two convergence yokes is responsive to a difference between the correction signal value coupled to the one convergence yoke and the correction signal values coupled to the other two convergence yokes.