Film cleaner method and apparatus

Claim 1

Method of cleaning photographic film that includes: (a) providing a venturi shaped cleaning zone between upper and lower hollow bars and passing film laterally through that zone, (b) providing streams of air flowing through said bars via holes directed toward said zone so that the gas streams flow toward opposite sides of the film as it passes in said zone, and (c) supplying ions of opposite polarity to said air streams and in cyclically reversing polarity relation, thereby cyclically reversing the polarity of ions supplied to each of two air streams one air stream flowing toward one side of the film via holes in the upper bar and another air stream flowing toward the opposite side of the film via holes in the lower bar, the polarity of ions supplied to said one air stream being positive when the polarity of ions supplied to the other air stream is negative, and vice versa, the film passing randomly through said zone with time varying spacing from said upper and lower bars, (d) and wherein ion dispensing tips are exposed to said air streams, and wherein cyclically varying high voltages are applied to said tips to that positive voltages peak as applied to tips exposed to air streams flowing toward one side of said zone at the same time that negative voltages peak as applied to tips exposed to air streams flowing toward the opposite side of said zone, and vice versa, with zero voltage node levels applied to all tips, simultaneously and cyclically, the zero voltage nodes occurring simultaneously, (e) initiating said supply of ions when film is caused to randomly enter said zone, and stopping said supply of ions when film completely leaves said zone, (f) providing two electromagnetic beams passing crosswise through said zone at the film entrance side thereof, and two electromagnetic beams passing crosswise through said zone at the film exit side thereof, (g) causing air flowing into said zone via each of said bars to flow through all of said beams, at said entrance and exit sides of the zone, initiating said supply of ions when the randomly moving film intercepts one or both of the beams at the entrance to said zone, and stopping said supply of ions when the film ceases to intersect the beams at the exit side of said zone.