Electrostatic matrix head construction

Claim 2

A multi character matrix printing head assembly for electrostatic printers comprising a plurality of stacked, superposed, printed circuit insulative boards cemented together, each of said boards having a leading edge and trailing edge, and including a plurality of groups of mutually spaced linear printing electrodes on one side of each board which terminate along the leading edge of said board a number of spaced back electrodes on an opposite side of said board which is equal to the number of printing electrodes in a group, the back electrodes extending parallel to the leading edge over substantially the full length of the leading edge, and means for electrically connecting each printing electrode of each group to a preselected back electrode, whereby corresponding printing electrodes in each of the group are electrically connected together and isolated from other elements in the same character position.

Claim 5

A multi-character printing head comprising a plurality of elongate insulative circuit boards stacked one on top of the other and secured to each other, the boards of each stack having a common aligned edge defining a printing surface of the head, the boards further having progressively varying widths so that a portion of a side of each board remote from the printing surface is exposed, a plurality of printing electrode sets, each set having a plurality of electrodes distributed over the length of each board, the electrodes on each board being secured to another side of the board and terminating at the printing surface, printing electrode sets on adjacent boards being mutually aligned, the printing electrodes further extending away from the printing surface to the area of the exposed sides, back electrodes running over substantially the lengtH of the boards parallel to the printing surface secured to the exposed sides of the respective boards, the number of back electrodes equalling the number of printing electrodes in the sets, and means connecting each back electrode with the printing electrode in a given relative position within a set.

Claim 6

A multi-character printing head comprising a plurality of elongate insulative circuit boards stacked one on top of the other and secured to each other, the boards of each stack having a common aligned edge defining a printing surface of the head, the boards further having progressively varying widths so that a portion of a side of each board remote from the printing surface is exposed, a plurality of printing electrode sets, each set having a plurality of electrodes distributed over the length of each board, the electrodes on each board being secured to another side of the board and terminating at the printing surface, printing electrode sets on adjacent boards being mutually aligned, the printing electrodes further extending away from the printing surface to the area of the exposed sides, back electrodes running over substantially the lengtH of the boards parallel to the printing surface secured to the exposed sides of the respective boards, the number of back electrodes equalling the number of printing electrodes in the sets, and means connecting each back electrode with the printing electrode in a given relative position within a set.

Claim 7

A matrix printing head assembly comprising a laminate of a plurality of flat insulative boards, each board having a top surface, a bottom surface, and at least one edge, the one edge of each board being aligned with the one edge of each other board to define a planar surface, the top and bottom surface of each successive insulative board extending progressively beyond the top and bottom surface of the preceding board; a plurality of printing arrays positioned on said planar surface, each array composed of a rectangular grid of electrically conductive writing stylii substantially uniformly spaced one from another, the size of each grid corresponding to the size of an alphanumeric character to be printed, a plurality of groupings of mutually spaced printing electrodes disposed on the bottom surface of each insulative board, said electrodes terminating along said one edge of said board to define said electrically conductive writing stylii; a plurality of parallely spaced back electrodes on the top surface of said insulative board, disposed at right angles to said printing electrodes and passing thereabove, the number of back electrodes corresponding to the number of printing electrodes in each grouping of printing electrodes for a given board , the back electrodes of each board being disposed on that portion of the board extending beyond the board stacked immediately adjacent thereto, the printing electrodes extending from said edge to a point directly below said back electrodes; and means electrically connecting each printing electrode to a single back electrode carried on the same board, corresponding elements in each character position being connected to the same back electrode and insulated from other elements in the same character position.

Claim 8

A matrix printing head assembly comprising a laminate of a plurality of flat insulative boards, each board having a top surface, a bottom surface, and at least one edge, the one edge of each board being aligned with the one edge of each other board to define a planar surface, the top and bottom surface of each successive insulative board extending progressively beyond the top and bottom surface of the preceding board; a plurality of printing arrays positioned on said planar surface, each array composed of a rectangular grid of electrically conductive writing stylii substantially uniformly spaced one from another, the size of each grid corresponding to the size of an alphanumeric character to be printed, a plurality of groupings of mutually spaced printing electrodes disposed on the bottom surface of each insulative board, said electrodes terminating along said one edge of said board to define said electrically conductive writing stylii; a plurality of parallely spaced back electrodes on the top surface of said insulative board, disposed at right angles to said printing electrodes and passing thereabove, the number of back electrodes corresponding to the number of printing electrodes in each grouping of printing electrodes for a given board , the back electrodes of each board being disposed on that portion of the board extending beyond the board stacked immediately adjacent thereto, the printing electrodes extending from said edge to a point directly below said back electrodes; and means electrically connecting each printing electrode to a single back electrode carried on the same board, corresponding elements in each character position being connected to the same back electrode and insulated from other elements in the same character position.

Claim 9

A matrix printing head for an electrostatic printer comprising in combination a plurality of printed circuit insulative boards superposed one atop another, each board having a leading edge and a trailing edge, the leading edges of said boards being aligned to define a planar surface; at least two groups of spaced electrodes on one side of each board, the number of electrodes within each group being the same, said groups of electrodes terminating at the leading edge of said board at spaced points to define a row of printing elements; a plurality of continuous spaced, back electrodes on the other side of each board equal in number to the number of printing electrodes within a group, and means for electrically connecting each of said back electrodes to corresponding ones of said printing electrodes in each group whereby each printing electrode within a group is electrically isolated from other printing electrodes within the same group so that a plurality of groups can be formed on one set of circuit boards and interconnected on these same circuit boards, and connected to corresponding electrodes within each other group.

Claim 10

A matrix printing head for an electrostatic printer comprising in combination a plurality of printed circuit insulative boards superposed one atop another, each board having a leading edge and a trailing edge, the leading edges of said boards being aligned to define a planar surface; at least two groups of spaced electrodes on one side of each board, the number of electrodes within each group being the same, said groups of electrodes terminating at the leading edge of said board at spaced points to define a row of printing elements; a plurality of continuous spaced, back electrodes on the other side of each board equal in number to the number of printing electrodes within a group, and means for electrically connecting each of said back electrodes to corresponding ones of said printing electrodes in each group whereby each printing electrode within a group is electrically isolated from other printing electrodes within the same group so that a plurality of groups can be formed on one set of circuit boards and interconnected on these same circuit boards, and connected to corresponding electrodes within each other group.

Claim 11

The matrix printing head of claim 5 wherein the printing electrodes are parallel spaced, intersecting the leading edge of the board at right angles thereto, and the back electrodes are parallel spaced, disposed at right angles to said printing electrodes and extend over substantially the full length of the planar surface.

Claim 12

The matrix printing head of claim 5 wherein the insulative boards define a step-like configuration, the spaced back electrodes on each board lying on that portion of each board which extends beyond the trailing edge of the preceding insulative board.

Claim 13

The matrix printing head of claim 5 wherein the back electrodes of each board are electrically connected to the corresponding printing electrodes on the same board by plated through holes provided in said insulative board.

Claim 14

The matrix printing head of claim 5 including an insulative base board mounted beneath the bottommost board of the matrix printing head.