This paper describes a type of digital TV tracking window controled by Iight pen for practical applications.At first the functions of TV tarcking Window in TV tracking system

type of TV tracking window

the difference between automatic Window and hand window

and the structure principle of digital tracking window with side-frame have been given.Then the light Pen control of TV tracking window

including the principles of light pen structure

positioning

circuit structure and operation principle of tracking window position controled by light pen and some cautions in the use of light pen are described.