Browse Prior Art Database

Magnetic Ink Hopper Content Control

IP.com Disclosure Number: IPCOM000097670D
Original Publication Date: 1961-Apr-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 63K

Publishing Venue

IBM

Related People

Rutter, DE: AUTHOR

Abstract

Magnetic images produced by a record head 10 on the surface of magnetic drum 11 are developed by magnetic ink particles 12 flowing in a stream from a hopper 13 onto an impression roller 14. Excess particles from the stream are collected in a container 15 and returned to the hopper 13. Developed images are transferred from the surface of 11 to a print medium such as paper 16 by pressure applied by roller 17. Paper 16 is fed from supply roll 18 over guide roll 19 to take up roll 20. Images transferred to 16 are pressure fixed by rolls 21.

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 77% of the total text.

Page 1 of 2

Magnetic Ink Hopper Content Control

Magnetic images produced by a record head 10 on the surface of magnetic drum 11 are developed by magnetic ink particles 12 flowing in a stream from a hopper 13 onto an impression roller 14. Excess particles from the stream are collected in a container 15 and returned to the hopper 13. Developed images are transferred from the surface of 11 to a print medium such as paper 16 by pressure applied by roller 17. Paper 16 is fed from supply roll 18 over guide roll 19 to take up roll 20. Images transferred to 16 are pressure fixed by rolls 21.

The supply of particles 12 in 13 is preferably maintained at a predetermined minimum level. For that purpose, a magnetic ink sense device 22, comprising a pair of coils 23 and 24 wound on a U-shaped magnetic core 25, is located at the appropriate level outside 13. The ends of 25 are placed in contact with the outside surface of 13 which is a nonmagnetic material. The magnetic ink particles inside the hopper coact with 25 to provide a variable reluctance transformer. Coils 23 and 24 of the variable reluctance sense element are connectable with triode 26 in a class C amplifier. Capacitor 27 is connected to the grid of triode 26 and the common point of coils 23 and 24, which is grounded. A resistor 28 connects the grid of 26 to ground. The cathode circuit of 26 includes variable resistor 29 coupled with a bypass capacitor 30. The plate circuit of 26 is connected to a coil of a relay 31. The latter...