  A tree view or tree navigator is used to display hierarchical data organized
in the form of a tree. In a tree structure there are parent and child nodes.
The child nodes may further have descendants to n levels.
  There are many methods to make the navigation easy. Some of these are
expanding and collapsing branches, splitting the tree, displaying a parent node
in a separate tree, zooming branches, scrolling in various directions etc. It
is still a difficult exercise to handle large trees efficiently. The effort
still continues to manage large number of nodes with faster speed, greater
control, user friendliness and aesthetics.
  This article illustrates five inventions on tree navigators selected from US
patent database. Each of them tries to solve various problems relating to the
tree navigator in different ways. Each invention is also analyzed from a TRIZ
perspective.
