Honeywell G.m.b.h.

Roger D Erickson

Paul A Diddens

William R Chynoweth

Boyce D Braschler

Charles J O'Toole, Jr

An improvement in electrographic recorders to increase the speed of writing that is possible by utilizing a magnetic member behind the paper and by preventing writing signals to occur until the toner is in such a position that writing is possible.

Electrographic recorder with enhanced writing speed

An electrographic recording system includes means wherein toner powder having electrical and magnetic properties is deposited on a recording medium, as a solid blanket of toner which is transported by the record medium to a recording station where selected portion of that toner coating is caused to adhere to the record member in a data determined pattern while the rest is collected by suitable magnetic structure at the recording station, then unto to a fixing station whereat the record data toner particles are permanently fixed to the record member. Alternatively, toner particles are transmitted to a recording medium by a rotating drum and, under the influence of electrodes thereat cause selective particles to be adhered to the record medium. The record medium then passes from such a recording station, again, to a fixing station whereat the toner particles are permanently fixed to the record member. In such systems, a control system for the operation of such apparatus, includes a time delay arrangement wherein at the termination of a recording cycle the recording signals are turned off instantly and a time delay is instituted which is a function of the paper speed and the relative distances on the record member between the toner deposit position and the fixing position. The time delay is effective to delay the cessation of the advancement of the record member through the fixing position until such time as all of the toner remaining on the record member has passed the fixing station.

Electrographic recording apparatus with delayed paper drive termination

In an electrographic recording system wherein a dynamic bridge of toner particles, the particles having electrical and magnetic properties, corresponding to a concentrated magnetic field formed between a toner carrier and the recording medium, an improved stylus array is provided. The stylus array includes a thin strip of magnetically permeable material secured to the undersurface of the stylus array but insulated from the styli, themselves. The permeable strip tends to modify the configuration of the magnetic field, pulling the toner bridge into intimate contact with the tips of the styli.

Electrographic recording

A stylus array for electrographic recording which includes a laminated stack of stylus elements, each separated from the next adjacent stylus element by a non-conductive layer. The stack array of stylus elements is contoured to have a forward end shaped to conveniently fit between the toner shell and a record receiving medium. The rear end of the stylus array is step contoured to provide two levels, to either of which an electrical contact may be made. Preferably the electrical contact is made to one step on alternate ones of the styli and the intermediate styli are connected electrically at the other step thus providing a measure of separation between the electrical connectors. A non-conductive layer is fixed to the lower edge of the stylus array to provide a sliding low-friction surface for engagement with the upper surface of the recording medium.

Electrographic recording stylus

An electrographic recording system includes means wherein toner powder having electrical and magnetic properties is carried from a hopper to a recording station by a rotatable drum or shell. The shell is rotated about a magnetic core structure which produces a magnetic field to hold the toner powder onto the surface of the shell as it rotates. At the recording station, a dynamic bridge is formed of the toner powder between the periphery of the drum and a magnetically permeable member positioned a predetermined distance from the surface of the drum. A record member is driven along a path between the drum and the permeable member with the reverse side of the record member in contact with the permeable member. An array of recording electrodes are positioned to be in electrical contact with the toner powder in the bridge. The record member is backed up by an electrically conductive platen. When one or more of the electrodes is energized a conductive path is established from the electrode through the bridge to the surface of the recording member and the conductive backup plate, electrically charging the dielectric surface of the recording member to deposit toner thereon.

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Denver, CO, United States of America

Roger D Erickson