Acer 7277e Service Manual page 27

Fig.3 Barreling Measurements
A, B represented as display area width and height
Top/Bottom Pincushion = (a1 or a2)
Side Pincushion = (b1 or b2)
substituted A by (PS + QR)/2
System Overview
B by (PQ + RS)/2
No Copy/Reproduction Allowed
=
API Confidential
1-21