Browse Prior Art Database

Operating a Magnetic Ink Jet Printer

IP.com Disclosure Number: IPCOM000088010D
Original Publication Date: 1977-Apr-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 4 page(s) / 60K

Publishing Venue

IBM

Related People

Helinski, FF: AUTHOR [+3]

Abstract

In a magnetic ink jet printer a continuous stream of ferrofluid ink drops 10 is projected from nozzle 11 toward the print medium 12. Drops 10 not used for printing are deflected by pulses from source 13 applied to winding 14 on core 15 of the dual selector 16 for deposition in gutter 22. Raster scan signals are applied to magnetic selector 18 by a raster scan generator 19 to vertically deflect drops for deposition on horizontally movable paper 12.

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Operating a Magnetic Ink Jet Printer

In a magnetic ink jet printer a continuous stream of ferrofluid ink drops 10 is projected from nozzle 11 toward the print medium 12. Drops 10 not used for printing are deflected by pulses from source 13 applied to winding 14 on core 15 of the dual selector 16 for deposition in gutter 22. Raster scan signals are applied to magnetic selector 18 by a raster scan generator 19 to vertically deflect drops for deposition on horizontally movable paper 12.

The method for operating the ink jet printer of Fig. 1 basically involves rastering a column of ink drops for each single recorded column of a character. However, the column of ink drops contains essentially only half the drops required to print a solid vertical bar. The rastered columns of drops, if allowed to be deposited on paper 12, are separated in the vertical direction by gaps. If a dot is required to be printed in a gap, an ink drop is "stolen" from the subsequent (or previous) rastered column of drops and so on. This means that since printing is done on-the-fly, the "stolen" drops must be deflected transverse to the direction of motion. A "steal" pulse is applied to winding 17 (or 14 if stealing from previous raster) by the selection pulse source 13 under control of character generator 20. A bias drive 21, controlled by the drop selection pulse source 13, applies a DC bias to magnetic deflector 18 to cause vertical shifting of the drops one dot space.

The manner of printing in accordance with this method is shown in Fig. 2 relative to printing the character Z. In column 1, for drop raster 1, drops are available for alternate positions 1, 3, 5...13. For every other column position, there is an option to put drops on the paper covering spots 2, 4, 6, 8, etc. In addition to this, as previously mentioned, there are many horizontal strokes at the top, bottom and middle of the characters. Thus, for the raster shifte...