Dual mode electrographic recorder

Claim 2

Apparatus for rendering latent images visible, said apparatus comprising: a first developer applicator having an arcuate surface capable of retaining developer, said first applicator being rotatably supported adjacent the path of movement of a recording member; a second developer applicator capable of retaining developer, said second developer applicator being rotatably supported adjacent the path of movement of said recording web; means containing a supply of developer through which said second applicator is rotatable; means rendering said second developer applicator operable in a first mode of operation to bring developer to a zone through which said recording member passes; means for preventing said second applicator from bringing developer to said zone, in a second mode of operation; and means operable to effect cooperative engagement of said first and second applicators during said second mode of operation whereby said second applicator serves as a donor for said first applicator.

Claim 3

Apparatus according to claim 1 wherein, said developer comprises electroscopic marking particles mixed with iron particles; and said means rendering said second developer applicator operable in a first mode comprises means for rendering said second applicator operable as a magnetic brush.

Claim 4

Apparatus according to claim 2 wherein, said means rendering said second developer applicator operable in said first mode comprises drive means for rotating said second applicator in one direction; and a magnet positioned adjacent the path of said recording web and disposed internally of said second applicator structure, said magnet being ineffective to render said second applicator operable as a magnetic brush during rotation of said second applicator in a direction opPosite said one direction.

Claim 5

Combination donor and developer applicator structure for use in a developing system, said structure comprising: a member having a continuous surface, said surface exhibiting a relatively high affinity for electroscopic marking particles thereby rendering said structure suitable as a donor member; means supporting said member for movement in two directions; and means for rendering said structure operable as a magnetic brush during movement in only one of said directions whereby said structure functions as a developer applicator.

Claim 6

Combination donor and developer applicator structure for use in a developing system, said structure comprising: a member having a continuous surface, said surface exhibiting a relatively high affinity for electroscopic marking particles thereby rendering said structure suitable as a donor member; means supporting said member for movement in two directions; and means for rendering said structure operable as a magnetic brush during movement in only one of said directions whereby said structure functions as a developer applicator.

Claim 7

Combination donor and developer applicator structure for use in a developing system, said structure comprising: a member having a continuous surface exhibiting a relatively high affinity for electroscopic marking particles; means for selectively moving said member in opposite directions; means for rendering said member operable as a magnetic brush during movement of said member in only one direction.

Claim 8

Combination donor and developer applicator structure for use in a developing system, said structure comprising: a member having a continuous surface exhibiting a relatively high affinity for electroscopic marking particles; means for selectively moving said member in opposite directions; means for rendering said member operable as a magnetic brush during movement of said member in only one direction.

Claim 9

Structure according to claim 5 wherein, said means for selectively rendering said member operable as a magnetic brush comprises a magnet stationarily disposed within said continuous surfaced member.

Claim 10

A dual mode electrographic apparatus comprising: a linear array of conductive styli; an elongated backing electrode defining a first recording station; means for selectively incrementing said linear array of styli through a first recording zone opposite said backing electrode during a first recording mode; first developer applicator means having an arcuate surface capable of retaining developer particles for bringing said particles to said first recording zone, said applicator being selectively rotatable about an axis substantially parallel to said first recording zone; a fixed linear array of conductive styli positioned opposite said elongated backing electrode and substantially coextensive therewith and forming a second recording zone therebetween; means for moving a web of insulative recording medium, first between said fixed array of styli and said elongated backing electrode and secondly between said elongated backing electrode and said incrementally movable array of styli; second development applicator means positioned along the path of the web between the first and second recording zones having a surface capable of retaining developer particles and rotatable about an axis parallel to the axis of said first developing applicator means; means rendering said second developer applicator operable in said first mode of operation to bring developer to said web at said first recording zone; means for preventing said second applicator from bringing developer to said web at said second recording zone, in a second mode of operation, while serving as a donor for said first applicator; and means operable to effect cooperative engagement of said first and second applicators during said second mode of operation whereby said second applicator serves as a donor for said first applicator.

Claim 11

A dual mode electrographic apparatus comprising: a linear array of conductive styli; an elongated backing electrode defining a first recording station; means for selectively incrementing said linear array of styli through a first recording zone opposite said backing electrode during a first recording mode; first developer applicator means having an arcuate surface capable of retaining developer particles for bringing said particles to said first recording zone, said applicator being selectively rotatable about an axis substantially parallel to said first recording zone; a fixed linear array of conductive styli positioned opposite said elongated backing electrode and substantially coextensive therewith and forming a second recording zone therebetween; means for moving a web of insulative recording medium, first between said fixed array of styli and said elongated backing electrode and secondly between said elongated backing electrode and said incrementally movable array of styli; second development applicator means positioned along the path of the web between the first and second recording zones having a surface capable of retaining developer particles and rotatable about an axis parallel to the axis of said first developing applicator means; means rendering said second developer applicator operable in said first mode of operation to bring developer to said web at said first recording zone; means for preventing said second applicator from bringing developer to said web at said second recording zone, in a second mode of operation, while serving as a donor for said first applicator; and means operable to effect cooperative engagement of said first and second applicators during said second mode of operation whereby said second applicator serves as a donor for said first applicator.

Claim 12

Apparatus according to claim 7 wherein, said developer comprises electroscopic marking particles mixed with iron filings; and said means rendering said second applicator operable in said first mode of operation comprises means for selectively rendering said second applicator operable as a magnetic brush.

Claim 13

Apparatus according to claim 8 wherein, said means rendering said second developer applicator operable in said first mode comprises drive means for rotating said second applicator in one direction and a magnet positioned adjacent the path of movement of said recording web and disposed internally of said second applicator structure.