The uPD7220 was designed by Tetsuji Oguchi, and information and schematics for the 7220 and 7220A can be found on his website: http://oguchi-rd.com/LSI%20products.php
The schematics are at http://oguchi-rd.com/schematics/logic/7220A/7220A%20Schematics.pdf
The patents for certain covering the the 7220 are: 4,459,676 - covers the accelerated bresenham curve drawing scheme
Other patents which probably cover the 7220 are: 4,356,482 4,491,834 4,545,014 4,570,222