Design of an Automatic Alignment System for Video Displays Using an Adaptive Alignment Algorithm


Department of Electrical Engineering,Ferdowsi University of Mashhad


One of the critical stages in a display production line is the image alignment of displays that
includes the precise adjustment of the geometric parameters and the color of the image. The
mutual in
uences of the parameters of the display's image necessitate a complex and interactive
alignment process. In this paper, the e ect of the mutual in
uences of geometric parameters
on the alignment process of a display's image are shown, a suitable model for the geometric
characteristics of a display's image are suggested and, then, the unknown parameters of the
proposed model are estimated by the RLS estimator. Using an o -line estimator, an initial
measure of the values of the unknown parameters of the display model is obtained. To modify the
model parameters of the consecutive video displays on the production line, an on-line estimator
is applied. Variations of the parameters of the display model on a production line are traced
using on-line estimation. This model estimation is used to implement an adaptive alignment
algorithm. Both the adaptive and the proportional alignment processes have been experimentally
implemented under similar working conditions. Experimental results show that the use of the
adaptive alignment process considerably increases the speed and reliability of convergence of
geometric parameters to their desired values. An IA-32, 3.4 GHz Pentium P4 processor has been
used in this research. Considering the rapid developments in UDSM technology and the IA-64
architecture, the application of the proposed adaptive alignment algorithm in an auto-alignment
system has the potential for real-time implementation in the near future.