International Business Machines Corporation

Lexmark International, Inc.

Jerry Wesley Raider

Randall David Mayo

Johann Hans Meier

Edmund Hulin James, Iii

Earl Dawson Ward, Ii

Joseph P Pawletko

Alan L Jones

Selahattin A Okcuoglu

Paul Albert Cook

Christopher Patrick Murphy

Kurt Matthew Korfhage

Christopher Keith Caspar

Blair Robertson Martin

Stephen Alexander Oleksa

Donald J Kacmarcik

A printing method for ink jet printing on a recording substrate in which a column of N dot forming nozzles for projecting ink onto a printing area are arranged, wherein N is an integer greater than 2. The column of dot forming nozzles are moved horizontally across the printing area and in each column of the printing area the printhead deposits one or more dots from a subgroup of S dot forming nozzles, wherein S is an integer of from 1 to about N&minus;1. In each column of the printing area, not more than every Gth nozzle deposits a dot and a single nozzle deposits a dot not more than every Gth column, wherein G is an integer from 1 to about S. The subgroup of S dot forming nozzles is shifted vertically among the N dot forming nozzles in at least two adjacent columns according to a predetermined pattern. The recording substrate is vertically advanced in a first direction by a height of about Q nozzles, wherein Q&equals;(S/G). Printer apparatuses including the printing method.

Method of ink jet printing with enhanced shingling and printer apparatuses for the same

Each sheet of a stack of media is aligned with a fixed alignment surface prior to being fed towards a process station of a printer by a single pick roll. During the first portion of its cycle of operation, the sheet advancing force of the pick roll, which is offset from the axis or centerline of the sheet, exerts a torque on at least the uppermost sheet of the stack to have one of its sides engage the alignment surface if it is skewed. When the one side of the sheet is not engaging the alignment surface when the pick roll is initially energized, the uppermost sheet's leading edge engages a resilient projection of an insert of a rib, which is offset from the axis of the sheet but farther from the alignment surface than the pick roll. The skewed sheet pivots about the projection, which is formed of a high coefficient of friction material, extending beyond the surface of the rib. During the remainder of its energization, the pick roll advances the sheet towards the process station of the printer.

Sheet aligning apparatus

A dam has a plurality of substantially parallel ribs extending from a base surface. At least one of the ribs is formed of a body of metal having a coating as its exterior surface, which has a low coefficient of friction over which sheets of a media move. The body has a longitudinal slot in its exterior surface. An insert, which has a high coefficient of friction with sheets of a media and is preferably polyurethane, is supported within the body. The insert is preloaded so that a projection extends a predetermined distance through the slot in the body for engagement with each advancing sheet. When the sheet is stiff, the projection is pushed interior of the body so that the low coefficient of friction surface, which has a much larger area for engaging the sheet than the insert, of the body is engaged by the advancing sheet. When the sheet is flexible, the projection of the insert engages the advancing edge of the sheet so that only the high coefficient of friction of the insert is initially engaging the advancing sheet to cause it to buckle or become corrugated so that portions of the sheet engage the low coefficient of friction of the exterior surface of the body to separate the sheet from the next adjacent sheet in the stack.

Sheet separator

A method for quickly testing stepping motors (10). The motor phases (.PHI.A-.PHI.C) are connected in series, and a constant current is applied to the phases. The rotor (12) of the motor (10) under test is rotated unidirectionally at a constant speed, and the voltage drop across each phase is measured and converted into back EMF. The back EMF is then analyzed to determine a characteristic of the motor (10), for example stepping accuracy of each of the phases, or related torque information, and the result of the analysis is then compared with a predetermined motor parameter to provide comparison data or a signal of a pass or fail condition based upon the comparison.

Method of testing stepping motors

A stepper motor damping control system. Damping is performed by switching the power supply connection(s) of energized motor phase windings alternatively ON and OFF at a predetermined relatively high fixed rate. Said switching is performed using a clock signal information for switching one way and an information denoting equality between a voltage substantially proportional to the current flowing through said motor phase windings with a predetermined sawtooth sloped reference signal synchronized with said clock signal for switching the other way.

Stepper motor drive system

In a daisy wheel or rotary print wheel typewriter, a single motor is employed to accomplish both ribbon lift and feed for typewriter ribbon and correction ribbon loaded in a cartridge assembly. A single motor drive moves the cartridge assembly support about an axis to present the typewriter ribbon or the correction ribbon to the print point at the print line. When the elevation of the cartridge assembly about the axis is such to permit normal typing upon the typewriter ribbon, only the feed ratchet for the ribbon is engaged. Alternatively, when the rotation is greater, for example, for typing on the correction ribbon, the added elevation of the cartridge assembly effects disengagement of the normal ratchet feed for the typewriter ribbon while allowing advancement of the correction ribbon.

Ribbon feed and lift mechanism for a typewriter

Magnetoresistive displacement transducer arrangement for toothed magnetic members in which each transducer is formed by a pair of interconnected sections spaced from each other by the width of a tooth to provide greater change and improved symmetry in the output signal at the tooth edges. Multiple transducers can be positioned interdigitally for compact packaging for vernier type detection of motion. Transducer embodiments for both linear and rotary motion are disclosed.

Interleaved magnetoresistive displacement transducers

A rotatable print disk is mounted on a carrier which traverses along the print line. The disk is moved from each character position to the next by the shortest distance and it is stopped at the time of printing. The carrier is moved from one print position to the next at a speed which is selected depending on the time required for the disk to rotate to the next character. Printing takes place with the carrier moving at one of a number of speeds. Hammer firing is timed dependent on printing speed.

Controls for a movable disk printer

Adaptive control circuit for a stepping motor in which each motor displacement from a present position to a target position is monitored and the proportion of acceleration signals to deceleration signals is modified as necessary to obtain minimal elapsed time during motor movement. Each designated motor displacement is assigned a corresponding number of acceleration signals which are applied to move the motor. Then during a subsequent homing of the motor, the motor displacement is monitored and the number of acceleration signals previously applied is either altered or left unchanged as a result of comparison between this displacement and a standard. The adaptive control circuit is shown as applied to printing apparatus in which a print disk is variously rotated by a first stepping motor mounted on a carrier and the carrier is moved along a print line by a second stepping motor.

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Lexington, KY, United States of America

Jerry Wesley Raider