Ink drop stream integrity checker in an ink jet printer

Claim 2

In an ink jet printer wherein a stream of drops of ink are projected through an electric field, the method of determining whether or not the path of such ink drop stream through said field is acceptable comprising: generating signals representative of the modulation of said field as an ink drop stream passes therethrough, establishing reference signals representative of an acceptable modulation of said field, comparing said generated signals with said reference signals and producing output signals as a result, and displaying said output signals.

Claim 3

In an ink jet printer of the type wherein an electric field is established and a stream of ink drops is projected through said electric field toward a substrate, means for determining whether or not the path traversed by said ink drop stream, in passing through said electric field is proper comprising: sensing electrode means, positioned to be within said electric field, to generate a current representative of the modulation of said electric field by said ink drop stream passing therethrough, and means responsive to said current generated by said sensing probe means for indicating the occurrence of undesired modulation of said electric field and therefore an improper path is traversed by said ink drop stream and for producing an indication thereof.

Claim 4

In an ink jet printer of the type wherein an electric field is established and a stream of ink drops is projected through said electric field toward a substrate, means for determining whether or not the path traversed by said ink drop stream, in passing through said electric field is proper comprising: sensing electrode means, positioned to be within said electric field, to generate a current representative of the modulation of said electric field by said ink drop stream passing therethrough, and means responsive to said current generated by said sensing probe means for indicating the occurrence of undesired modulation of said electric field and therefore an improper path is traversed by said ink drop stream and for producing an indication thereof.

Claim 5

In an ink jet printer as recited in claim 1 wherein said electric field is established between two deflection plates, and said sensing probe means is positioned adjacent the downstream end of one of said two deflection plates.

Claim 6

In an ink jet printer as recited in claim 2 wherein said electric field is established between two deflection plates, one of said deflection plates having a hole therein, and said sensing probe means is positioned within said hole.

Claim 7

In an ink jet printer as recited in claim 3 wherein said sensing probe means comprises a conductive tube, and wherein said conductive tube also functions to capture drops not desired for printing.

Claim 8

In an ink jet printer as recited in claim 2 wherein a plurality of ink jet streams arE projected through said electric field and there is included means responsive to the currents generated by said sensing means for indicating whether or not each one of the plurality of ink jet streams passes through an accepted predetermined location within said electric field.

Claim 9

In an ink jet printer wherein streams of drops of ink are projected through an electric field, means for determining whether or not the path of such ink drop streams through said field is acceptable comprising: sensing probe means positioned at a location within said field such that the field lines are modulated by passage of said ink drop stream therethrough to generate signals representative of the distance of said ink drop stream from said probe, means for establishing reference signals representative of an acceptable distance of said ink drop stream from said sensing probe, means for comparing said reference signals with said signals from said sensing probe means, and means responsive to an output from said comparator to produce an indication thereof.

Claim 10

In an ink jet printer wherein streams of drops of ink are projected through an electric field, means for determining whether or not the path of such ink drop streams through said field is acceptable comprising: sensing probe means positioned at a location within said field such that the field lines are modulated by passage of said ink drop stream therethrough to generate signals representative of the distance of said ink drop stream from said probe, means for establishing reference signals representative of an acceptable distance of said ink drop stream from said sensing probe, means for comparing said reference signals with said signals from said sensing probe means, and means responsive to an output from said comparator to produce an indication thereof.