A program switching device and a method thereof which can prevent a disorder of images and an invisible state of the image when a channel (program) is switched. When it is instructed to switch a program to the other program in the state where the image of a program of a predetermined channel is displayed,...http://www.google.com.hk/patents/US7540010?utm_source=gb-gplus-share專利 US7540010 - Program switching device and method
