Lamp makers: Tight supply of projector and RPTV lamps to persist &lt;b&gt;...&lt;/b&gt; A tight supply of lamps for front projectors and rear-projection TVs (RPTVs) is likely to persist through 2005 as Taiwan-based projector makers are increasing their shipments of RPTV optical engines, said lamp makers Ushio, Royal Philips Electronics and 