Single sheet ink-jet printer with passive drying system

An ink-jet printer comprising in associative combination:

• (a) a paper supply means for providing a supply of a medium to be printed;
• (b) a paper collection means for collecting printed medium;
• (c) means for conveying a sheet of said medium from said paper supply means to said paper collection means through a printing zone, said sheet conveying means including a mechanism for picking said sheet of said medium from the rear portion of said paper supply means, a rotatable paper drive shaft having mounted thereon a plurality of paper drive roll wheels fixedly mounted thereon, means for rotating said paper drive shaft, and pinch wheel means for maintaining said sheet of said medium against said paper drive roll wheels;
• (d) a pivotable platen in said print zone including means for pivoting said platen downward at the completion of printing each said sheet;
• (e) a printhead mounted on a printhead carriage adapted to moved orthogonal to movement of said medium for printing on said medium supported on said platen;
• (f) means for creating a reverse bow in said sheet of said medium for directing said sheet in a plane parallel to said printing zone just prior to entering said printing zone for maintaining flatness of said sheet;
• (g) means for permitting ink on a previously-printed sheet of said medium to dry during printing of a next sheet of said medium, including a pair of opposed support rails positioned above said paper collection means and of a width sufficient to support said sheet of said medium during printing but less than that required to support said sheet of said medium upon downward pivoting of said platen at the completion of said printing;
• (h) mechanically-actuated multiplexer means for at least initiating pick-up of said sheet and for initiating said downward pivoting of said platen;
• and
• (i) means for controlling said medium-conveying and said printing operations.

An ink-jet printer comprising in associative combination:

• (a) a user-facing paper supply tray for providing a supply of a medium to be printed;
• (b) a user-facing paper collection tray for collecting printed medium, said paper collection tray maintained above said paper supply tray in tandem arrangement;
• (c) means for conveying a sheet of said medium from said paper supply tray to said paper collection tray through a printing zone, said means including a mechanism for picking said sheet of said medium from the rear portion of said paper supply tray, a rotatable paper drive shaft having mounted thereon a plurality of paper drive roll wheels fixedly mounted thereon, means for rotating said paper drive shaft, pinch wheel means for maintaining said sheet of said medium against said paper drive roll wheels, said mechanism for picking said sheet of said medium including (1) an articulating portion of said paper supply tray, adapted to pivot about an axial pivot, (2) a spring means for urging said articulating portion upward toward said paper drive rollers, (3) a cam comprising a truncated disk, the disk portion of which urges said articulating portion downward and the truncated portion of which permits said upward movement of said articulating portion, and (4) a gear train for translating rotary motion of said drive shaft to said cam;
• (d) a pivotable platen in said print zone adapted to pivot downward at the completion of printing each said sheet, said pivotable platen including means for pivoting said platen downward at the completion of said printing;
• (e) an ink-jet printhead mounted on a printhead carriage adapted to move orthogonal to movement of said medium for printing on said medium supported on said platen;
• (f) means for creating a reverse bow in said sheet of said medium for directing said sheet in a plane parallel to said printing zone just prior to entering said printing zone for maintaining flatness of said sheet;
• (g) means for permitting ink on a previously-printed sheet of said medium to dry during printing of a next sheet of said medium, including a pair of opposed support rails positioned above said paper collection tray and of a width sufficient to support said sheet of said medium during printing but less than that required to support said sheet of said medium upon downward pivoting of said platen at the completion of said printing;
• (h) mechanically-actuated multiplexer means for at least initiating pick-up of said sheet and for initiating said downward pivoting of said platen;
• and
• (i) microprocessor means for controlling said medium-conveying and said printing operations.

An ink-jet printer comprising in associative combination:

• (a) means for conveying a sheet of a medium through a printing zone which includes a platen;
• (b) a printhead for printing on said medium supported on said platen, said printhead mounted in a printhead carriage adapted to move orthogonal to movement of said medium;
• and
• (c) means for providing a reverse bow in said sheet of said medium for directing said sheet in a plane parallel to said printing zone just prior to entering said printing zone for maintaining flatness of said sheet.