Interpolation method and apparatus for improving registration adjustment in a projection television

摘要

The nonlinear, deflection waveform used improve registration in a three picture tube projection television system is produced using interpolation of stored data setting points by first performing a reduced number of high-order interpolation calculations using the setting points and then performing low-order interpolation calculations either between two calculated high-order interpolated data points or between one of the calculated high-order interpolated data points and one of the setting points. This results in reducing the work load on the central processing unit in the registration system. In addition, a reduced bit-size requirement for the interpolation portion of the registration is obtained by storing registration data of a first bit size and then adding bits below the original LSB for the interpolation calculation prior to performing the digital to analog conversion.