Browse Prior Art Database

Ribbonless Multicopy Impact Matrix Printer

IP.com Disclosure Number: IPCOM000050211D
Original Publication Date: 1982-Sep-01
Included in the Prior Art Database: 2005-Feb-10
Document File: 3 page(s) / 56K

Publishing Venue

IBM

Related People

Lane, R: AUTHOR [+3]

Abstract

In an impact matrix printer, the printing of dots on the first copy of the paper is accomplished with an inked ribbon. The ink is transferred from the ribbon onto the paper with an impact of the hammer. Ribbon wear and its driving mechanisms are always a serious concern for an impact printer. This publication describes methods of depositing solid toner or liquid ink on the tips of the dots, and the toner or ink is then transferred to paper by hammer impact. With this arrangement, the ink ribbon can be eliminated and the multicopy feature can still be achieved.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 52% of the total text.

Page 1 of 3

Ribbonless Multicopy Impact Matrix Printer

In an impact matrix printer, the printing of dots on the first copy of the paper is accomplished with an inked ribbon. The ink is transferred from the ribbon onto the paper with an impact of the hammer. Ribbon wear and its driving mechanisms are always a serious concern for an impact printer. This publication describes methods of depositing solid toner or liquid ink on the tips of the dots, and the toner or ink is then transferred to paper by hammer impact. With this arrangement, the ink ribbon can be eliminated and the multicopy feature can still be achieved.

Two means of depositing toner or ink on the dot surface are described. One is to use a magnetic field, and the other is to use an electrostatic field. As shown in Fig. 1, a drum 10, with embossed dots arranged in, for example, a helical pattern, is rotating at a constant speed. A bank of print hammers 12 is set along the drum, and each hammer covers the pitch of the helix. With proper timing and sequence of hammer impact, all dots can be addressable. In this embodiment, an additional bar 14 is provided which spans the entire length of the drum. Bar 14 may be an electromagnet. The bar 14 will induce a magnetic field or an electro-static field in the embossed dots as the dots pass by the bar due to the rotation of the drum.

For magnetic field inking, bar 14 can be a permanent magnet or iron with a single coil to generate the magnetic field. The drum 10 is made of a non- magnetic metal with dots etched on the surface; the dot tips are deposited with a layer of magnetic material (such as nickel colbalt). During the rotation of the drum 10, the dots pass by the permanent magnet 14 and the tips of the dots are magnetized. A magnetic toner or a magnetic ink from source 16 is deposited on the dot tips as drum rotates by a developer station, as shown in Fig. 2. The dots carrying the toner then will rotate to the hammer station for impact. The impact will transfer ink onto the paper 18 without ribbon and also will be capable of making multiple carbon copies. It should be noted that only one magnetic bar is used.

For electrostatic field inking, the bar 14 in Fig. 2 is an electrode with high voltage. The drum 10, which is grounded, is made of conductive metal. The tips of the dots are then coated with a dielectric layer, such as alumina, titanium dioxide, or zinc oxide. When the dots rotate past the electrode 14, an electrostatic field is induced on the dielectric layer. As the dots with retained charge rotate to the toner supply 16, the charged toner will then be attached to the dot tips. The toner is then carried by the dots and moves to the front of the print hammers 12. With the impact of the hammer, the toner is transferred to th paper 18. A fusing station may not be required because of sufficient impact pressure.

With the proper thickness of the layer coated on the tips of the dots, the to...