International Business Machines Corporation

Peter A Stevenson

Stephen Martin Vogel

John H Dodge

Francis E Hauke

Thomas F Eichhorn

John Walton Woods

Donald L Janeway

Michael L Nettles

Chris Hawley

Robert Marion McElroy, Jr

Everette Ray McCully

Digital circuitry and microprocessor techniques are used to monitor the quality of toner operations in a copier and take appropriate corrective action based upon the monitoring results. Patch sensing is used. Reflectivity signals from the patch and from clean photoconductor are analog-to-digital converted and a plurality of these signals taken over discrete time periods of a sample are stored. The stored signals are averaged for use in determining appropriate toner replenishment responses and/or machine failure indicators and controls.

System for monitoring and controlling electrophotographic toner operation

A flexible, closed loop belt having a photoconductive surface is mounted internally to a xerographic-type copier. The belt mounting frame or guide, is arranged to include a series of interconnected courses defining a supporting path for the belt. One or more portions of the guide surface are formed as peripheral segments of a cylinder. Various courses are interconnected in a generally continuous closed loop path for the belt.

Noncircular photoconductor belt mounting apparatus and method

Lateral force is applied to a web material by an air bearing for the purpose of guiding the web against a fixed reference edge. A bearing surface over which the web is movable includes an arrangement of holes for establishing a differential flow across the bearing surface to produce a lateral force on the web in the direction of the reference edge. The holes are arranged asymmetrically relative to the center line of the bearing surface but typically are parallel to the reference edge. The differential air flow is established by controlled sizes of apertures through the bearing plate, variable air permeability of the material forming the bearing surface or the like. A common source of pressurized air is coupled to all of the bearing surface holes.

Differential flow guiding air bearing

In a reel-to-reel longitudinally scanned tape transport or recorder, a length of media is positioned to fly in transducing relationship with a transducing head. The transducing head is mounted on a rotatable turntable rotor. The rotor includes a substantially circular member with concentric horizontal surfaces projecting in separate vertical planes. A cam shaped contour is fabricated on one of the horizontal surfaces with the transducing means positioned at the peak or crown of said cam shaped surface. There is a gradual roll off between the crown and the lowest point of the cam shaped surface. The roll off creates a converging channel which allows a sufficient volume of air to enter the interface between the media and the head and a diverging channel which allows the air to be bled off.

Longitudinal scan, cam shaped, turntable rotor for magnetic recording

A flying head, helical scan magnetic recording device comprises a tape source, a mandrel for supporting a helical wrap of magnetic tape, a rotor which is lobed with respect to the mandrel axis and a tape sink. The lobed rotor carries one or more magnetic heads at substantially the peak of the lobe around a flying scan path in non-contact, microinch adjacency to the magnetic tape supported on the mandrel. The major portion of the rotor, however, is recessed with respect to the magnetic tape, thereby minimizing the tendency of the tape to shear off the air bearing film carried by the rotor. The result is enhanced dynamic air bearing support of the tape in the immediate vicinity of the flying head.

Flying head helical scan magnetic recording device employing a lobed

A precision-surface is constructed to support magnetic tape on a dynamically-stiff air film above the surface. The precision-surface is achieved by using relatively thick stock material for the bearing. The bearing may be ground to the precise contour and dimensions for the desired tape path. A thin stiff air film between the bearing surface and the tape is provided by deep pools in the bearing surface. The bottom of each pool contains a single small hole in the order of 0.010 inch (0.254 mm.) in diameter for supplying air under pressure to the pool. The small holes are placed in the bottom of the pools preferably by using a thin foil with the holes etched therein and bonding the foil inside the rigid bearing so that the foil becomes the bottom of the pools. The total cross-sectional area of pools on the bearing surface is limited to a small percentage of the area of the bearing surface as the compressibility of the air in the pools can affect the stiffness of the air film.

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Boulder, CO, United States of America

Peter A Stevenson