Method for improving performance of an ink jet bar code printer

Claim 2

In an ink drop printer of the type wherein a stream of drops is emitted for printing a bar in a bar code, and wherein the leading drops in the stream are retarded, due to aerodynamic effects to thereby adversely affect the printing, the method of compensating for the adverse aerodynamic effects comprising generating a plurality of ink drops to form a stream, projecting said stream of ink drops in a path toward a receiving substrate for printing a bar thereon, removing from each stream of drops those drops immediately following the first of the drops in each stream which due to aerodynamic effects cannot align themselves with the remaining drops in said stream for printing a bar in a bar code, and deflecting the remainder of the drops in said stream of drops to desired locations on said substrate.

Claim 3

A method as recited in claim 1 wherein said step of removing one or more of the drops following the first drop in said stream of drops, and deflecting the remaining drops in said stream to desired locations on said substrate comprises intercepting said one or more drops following said first drop prior to reaching said substrate, applying charges to the remaining drops in said stream representative of the locations desired to be reached by said drops on said substrate, and establishing an electric field in the path of said drops toward said substrate through which said drops must pass to reach desired locations on said substrate.

Claim 4

In an ink drop printing system of the type wherein each bar in a bar code is printed by projecting a stream of ink drops in a path through the air toward a receiving substrate, and the leading drops in said stream of ink drops, due to aerodynamic drag, are slowed in their flight, thereby causing defective printing, the improvement comprising means for projecting successive streams of drops toward said substrate for correctly printing bars in a bar code, including means for removing those drops from each stream of drops immediately following the first ink drop in a stream of ink drops which, due to aerodynamic effects will not properly align themselves with the remaining ink drops in said ink drop stream for printing a bar in a bar code to thereby eliminate the defective printing caused by aerodynamic drag.

Claim 5

In an ink drop printing system of the type wherein each bar in a bar code is printed by projecting a stream of ink drops in a path through the air toward a receiving substrate, and the leading drops in said stream of ink drops, due to aerodynamic drag, are slowed in their flight, thereby causing defective printing, the improvement comprising means for projecting successive streams of drops toward said substrate for correctly printing bars in a bar code, including means for removing those drops from each stream of drops immediately following the first ink drop in a stream of ink drops which, due to aerodynamic effects will not properly align themselves with the remaining ink drops in said ink drop stream for printing a bar in a bar code to thereby eliminate the defective printing caused by aerodynamic drag.

Claim 6

In an ink drop printing system as recited in claim 3 wherein said means for removing those drops from each stream of said ink drops following said first ink drop in an ink drop stream includes means for applying a charge to each of said ink drops in an ink drop stream having an amplitude in accordance with the location it is desired for each drop to reach on the surface of the receiving substrate, means for establishing an electric field between said means for charging said drops in a stream and said substrate, and means within said means for applying a charge, for withholding a charge from each of said predetermined number of drops, to insure that they are deflected out of the path which the remaining drops in said stream take when passing through said electric field.

Claim 7

In an ink drop printer of the type wherein a stream of drops is emitted for printing a bar in a bar code, and wherein one or more of the leading drops in the stream are retarded, due to aerodynamic effect thereby adversely affecting the printing, apparatus for compensating for the adverse aerodynamic effect comprising means for projecting a stream of drops in a path towards a receiving substrate to print a bar thereon, means along said path for intercepting drops having a predeteRmined charge and preventing them from reaching said substrate, means, along said path and upstream of said means for intercepting drops, for charging each drop with a charge for deflecting each drop to a desired location on said substrate and for charging with said predetermined charge successive drops following the first drop in a stream, which, due to aerodynamic effects will not align themselves with the remaining drops in said stream for printing a bar in a bar code, whereby said predetermined charged drops are intercepted by said means for intercepting, and means for establishing an electric field along said path for deflecting each of said drops in accordance with the charge applied thereto, whereby said first drop aligns itself with the remaining drops reaching said substrate to thereby eliminate said adverse printing effect.

Claim 8

In an ink drop printer of the type wherein a stream of drops is emitted for printing a bar in a bar code, and wherein one or more of the leading drops in the stream are retarded, due to aerodynamic effect thereby adversely affecting the printing, apparatus for compensating for the adverse aerodynamic effect comprising means for projecting a stream of drops in a path towards a receiving substrate to print a bar thereon, means along said path for intercepting drops having a predeteRmined charge and preventing them from reaching said substrate, means, along said path and upstream of said means for intercepting drops, for charging each drop with a charge for deflecting each drop to a desired location on said substrate and for charging with said predetermined charge successive drops following the first drop in a stream, which, due to aerodynamic effects will not align themselves with the remaining drops in said stream for printing a bar in a bar code, whereby said predetermined charged drops are intercepted by said means for intercepting, and means for establishing an electric field along said path for deflecting each of said drops in accordance with the charge applied thereto, whereby said first drop aligns itself with the remaining drops reaching said substrate to thereby eliminate said adverse printing effect.