Problem statement : wall hanging based decorative articles ...calenders ...other display stuff.
 
                    how suspension is done....

                    taking the case of a calender or other scratch pad ....

                    understanding printer drum/ roller.

                    how news-print/cloth is wrapped on a roller.

Opportunity :    taking or deriving a rectangular frame ....having two rollers , one each at top and the bottom 
                 suspended such that they are parallel to each other.

                 by having the paper/cloth mass suspended on one of the rollers ...the other roller can be used
                 to wrap or roll or scroll the paper/cloth ...viz... change the display area...

                 eg: notion or concept can be visualized using a calender,
                     mechanized hording space ...traditional printed versions.
                            
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Note: The above problem statement having been encountered in various scenarios
      and detailed in various 'Proof of concepts' as mentioned in 
      
       http://uk.geocities.com/ravivenkatus/projects.pdf
       http://ravishankarkv.tripod.com/projects.pdf
        ....apply appropriate
      'use-case' modeling, rationalize and arrive at a workable and feasible 
       solution both commercially and techinically viable.