International Business Machines Corporation

Lexmark International, Inc.

James J Molloy

Steven L Applegate

Paul Douglas Horrall

David Lee Merrifield

James A Craft

Benjamin Keith Newman

Earl Dawson Ward, Ii

Ronald Willard Baker

Martin Victor DiGirolamo

Bernard L Wilzbach

Stanley Dyer

Robert Leonard Burdick

Donald A Walker

Gregory Lawrence Ream

William Freeman

Harald Portig

Gary Neal Hackney

Phillip Byron Wright

Alan Stirling Campbell

Gary Scott Overall

Steven Alan Curry

Franklin Joseph Palumbo

James P Wang

Thoi Nguyen

Thomas Campbell Wade

James Philip Harden

Cyrus Bradford Clarke

David T Shadwick

Daniel George Mlejnek

Frank Marion Hughes

Donald Lee West

William L Dollenmayer

Timothy P Craig

Richard Andrew Seman, Jr

Charles S Aldrich

Clayton V Wilbur

Gary Michael Tylicki

Deh C Tao

Donald Thomas Kral

Michael Lewis Pawley

William F Voit, Jr

Thomas Gregrory Survant

Gregrory Lawrence Ream

David M Riherd

Thomas G Twardeck

Photoconductor unit

Toner ( ) is measured in a toner cartridge ( ) by compressing the air in the upper part ( ) of the toner hopper ( ). The result of the compression is observed by a diaphragm ( ) or, alternatively, by a pressure transducer ( ). The volume of air is inversely proportional to the resonant frequency of diaphragm ( ) or the pressure at pressure transducer ( ). This is converted by control system ( ) using direct equations or table look-up of empirical data. The diaphragm ( ) carries a magnet ( ), which is driven by coil ( ) from the imaging device and then frequency of current induced by magnet ( ) is then sensed by coil ( ). Uneven toner piling is not a significant factor in the results measured.

Measuring toner level in a closed container

A waste toner removal device for transporting toner from a photoconductive drum within an image-forming apparatus. The invention includes a waste toner reservoir having outer walls forming an interior chamber for housing toner removed from the photoconductive drum. An opening is positioned within the outer walls into the interior chamber forming an upper chamber section extending above the opening and a lower chamber section extending below the opening. An auger extends along the photoconductive drum and unobstructed into the opening of the waste toner reservoir. The auger includes helical blades extending outward for moving the toner from the photoconductive drum into the waste toner reservoir. A pumping cylinder having a generally cylindrical shape extends around the auger adjacent to the waste toner reservoir. The diameter of the pumping cylinder is approximately equal to the helical blades wherein rotation of the auger creates a pumping action for moving toner into the said upper and lower chamber sections.

Conveyor and waste toner reservoir for an image-forming apparatus

A toner cartridge (1) contains a photoconductive drum (49) having a central shaft (47). Gear (145) turns with the drum and has a stud (602). A coil spring (604) is mounted on the stud to form a spring clutch which is unwound by the rotation of the drum during imaging. Alternatively, a flat frictional surface is pressed against the side wall (600b) of the gear. Both contact areas have a light grease. The drag forces provide accurate, smooth operation during imaging.

Control of photosensitive roller movement

An improved electrophotographic (EP) printer is provided having a detachable process cartridge that contains a non-volatile memory device, which is an EPROM that cannot be erased after a bit is burned. A 'toner wheel' mounted to the exterior of the toner reservoir of the process cartridge provides, in conjunction with an optoelectronic sensor, an electrical signal that the printer receives and uses to determine toner usage. A toner 'gas-gauge' is created which uses 'bucket levels' as discrete steps to indicate how much of the measured physical toner material actually remains within the toner reservoir. After a given amount of toner material has been dispensed through the developer unit, one of the bits of the EPROM memory device is irreversibly burned, thereby providing a permanent record on the process cartridge of a certain amount of toner usage. As with a normal automobile gas gauge, the toner gas-gauge reading should never increase unless the amount of toner material inside the toner reservoir has increased. Once the bucket level transitions begin to occur for the toner gas-gauge, the printer becomes aware that a majority of the toner material has been expended from inside the toner reservoir. If the number of bucket gradation levels then increases by more than the hysteresis amount, then the printer will 'lock out' the operation of a non-reusable process cartridge. When the lock-out mode occurs, a particular bit is burned on the EPROM mounted to the cleaner housing of the process cartridge. This ensures that this particular process cartridge cannot be removed, then simply placed back into the same (or a different) printer, and then begin supplying toner to a printer. Certain important 'machine data' also can be stored in the EPROM memory device on the process cartridge of the present invention. The present invention is also able to declare the 'end-of-life' of a process cartridge when the gas-gauge toner sensor is not functional (such as when it has been tampered with).

Method and apparatus for storing data in a non-volatile memory circuit

A toner cartridge having no toner pump with the toner adding roller (11 ) positioned horizontal to the developer roller (3), the toner chamber (9) located predominantly below the developer roller, the photoconductive drum located 120 degrees from the top of tile developer roller, and the doctor blade (5) is located near the top. The cartridge has a minimal number of operational parts.

Reduced component toner cartridge

In a toner cartridge, photoconductor drum (11) is driven by a gear (3) which is in the printer, toner adder roller (48) is driven independently by a face coupling (5) which is in the printer. On the opposite side, a gear train from toner adder roller (48) drives developer roller (42) and toner paddle (52). The two systems permit the cartridge to function in different printers requiring different ratios of speeds. Stiffness requirements of the cartridge are reduced. Movements are more consistent, and space utilization is enhanced.

Toner cartridge with independent driven systems

An electrophotographic printer (11) having a base (13) and a top (12), the top (12) being pivotable about an axis (23) between a closed position and an open position. The printer (11) receives a supply cartridge (14) on a shelf (22) which is pivotable about the same axis (23) as the top (12) of the printer (11). A counterbalance spring (34) helps to support the shelf (22) and the cartridge (14) below the top (12) of the printer (11) and above the printer base (13) when the top (12) of the printer (11) is in its open position. When the top (12) of the printer (11) is closed, the cartridge (14) is urged into a position adjacent the printer base (13) and locked into an operative position.

Electrophotographic printer and cartridge arrangement

Metering roller (3) in the electrophotographic developer cartridge (1) is unsymmetrical along its length. As the metering roller rotates it distributes toner (11) both ways between chamber 13 and chamber 19 to maintain an equilibrium level (31) between the chambers. The unsymmetrical roller simultaneously reduces and increases the area of chamber 11, and possibly also provides a significant open path to chamber 19 across its flat surfaces (35), to inherently eliminate significant pressure build-up in chamber 13. The need for a vent between the chambers is eliminated.

Toner metering apparatus with pressure equalization

A developer apparatus (29) for use in an electrostatic reproduction apparatus includes a large reservoir of toner (34, 44). The toner is located in a supply chamber (39) and is metered to a developer roller chamber (35) from which it is carried by a developer roller (31) past a doctor blade (36) to a photoconductor drum (19) for image development. A toner metering roller (41) rotates with the developer roller (31) to provide a continuous supply of toner from the supply chamber (39) to the developer chamber (35). Once an equilibrium level (65) is reached, the toner metering roller (41) acts to remove toner (34) from the developer chamber (35) to the supply chamber (39) to insure proper operation of the developer roller (31).

Toner metering apparatus

Cartridge for an electrophotographic printer

A thermal printhead, which is pivotally mounted on a carrier, is moved into and out of its printing position by a four bar linkage, which is responsive to the direction in which the carrier is being advanced, rendering a spring, which urges the thermal printhead into its printing position, effective and ineffective. When the carrier is advanced from left to right to print, the linkage responds to a drive mechanism for the carrier to enable movement of the printhead into its printing position by the spring prior to the carrier drive mechanism moving the carrier. When the carrier is to be moved from right to left in the non-printing direction, the linkage responds to the initial motion of the carrier drive mechanism in this direction to render the spring ineffective and to move the printhead out of its printing position prior to the carrier drive mechanism moving the carrier.

Thermal printhead actuator responsive to carriage drive and including a

A symmetrical printer ribbon cartridge which is refillable. An internal, continuous drive belt (15) provides tension to push studs (33, 35) of the supply spool (23) and of a take-up spool (29) to the ends of notches (31, 32) in cartridge wall 1. When the original supply spool is emptied, a new spool need only be moved into place and the free end of the ribbon pulled from the new spool, directed through the ribbon path in the cartridge, and attached to the remaining spool.

Reloadable ribbon cartridge

A wear-resistant ribbon guide surface (11 or 25a, 25b) is added to a thermal printhead (1) to lower the ribbon exit angle after printing or to shift the ribbon exit position away from the printing. The angle past that surface remains large enough for visibility of prior printing. The modification of exit conditions makes the printing darker and significantly improves printhead life.

Thermal printhead with ribbon exit guide

Conservation of ribbon 40 is achieved by underfeeding ribbon 40 relative to movement of thermal printhead 16. Pressure of printhead 16 may be low enough that smearing from a typical ribbon 40 does not occur. Gears 208, 210, 212, 214 and 216 may be positioned in one of two settings by action of bellcrank 230. One position provides a 1.04 to 1 underfeed ratio and the other provides a 5 to 1 underfeed ratio. Control 232 lowers print current for the 5 to 1 ratio. A printer having a single ratio of 1.04 to 1 provides printing of unimpaired quality with significant saving of ribbon.

Feed rates and two-mode embodiments for thermal transfer medium

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Lexington, KY, United States of America

James J Molloy