In this episode I go through the part of the patent application called "The Background of the Invention."  Here you discuss what came before your invention and some of the shortcomings of the current devices.  You do not discuss your invention at all in this section. Leave the discussion of your invention to other sections.  You want to write this section in a way that makes the reader want to read the later sections that describe how you were able to overcome the problems in current devices.