Patents by Inventor Donald Wayne Stafford
Donald Wayne Stafford has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 7236730Abstract: There is provided a system and mechanism for substantially reducing or substantially eliminating vibration or noise of a doctor blade of an image forming apparatus during operation. The system and mechanism provided includes at least one contact in communication with a doctor blade surface, e.g., a front surface, to substantially reduce or substantially eliminate vibration and/or noise associated with a doctor blade during image forming.Type: GrantFiled: November 17, 2004Date of Patent: June 26, 2007Assignee: Lexmark International, Inc.Inventors: James Eric Dickerson, Robert Edward Hackett, Donald Thomas Kral, Donald Wayne Stafford
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Patent number: 7231163Abstract: The present invention relates generally to image forming equipment, e.g. a laser printer of the type which includes a photoconductive (PC) drum and an associated charge roller. The invention is disclosed in exemplary embodiment as a laser printer incorporating a cleaner element with an electrical potential to sufficiently charge contamination particles on the PC drum to electrically repel from a charged surface, such as the charge roller.Type: GrantFiled: February 11, 2005Date of Patent: June 12, 2007Assignee: Lexmark International, Inc.Inventors: Bhaskar Gopalanarayanan, Robert Watson McAlpine, Jamie Piotrowski, Donald Wayne Stafford
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Patent number: 7167672Abstract: A conveyor mechanism for moving waste toner within an interior of a waste toner reservoir. The conveyor mechanism has a first end positioned in proximity to an inlet into the waste toner reservoir, and a second end positioned vertically above the first end. The conveyor mechanism operates to move the toner from a lower position within the waste toner reservoir to the vertically elevated position. The conveyor device may allow for the capacity of the waste toner reservoir to be more fully utilized. In use, the conveyor device is activated and waste toner is moved into the upper reaches of the waste toner reservoir.Type: GrantFiled: February 22, 2005Date of Patent: January 23, 2007Assignee: Lexmark International, Inc.Inventors: Donald Wayne Stafford, Robert Watson McAlpine, Franklin Joseph Palumbo, Alfred Louis Fahmy, Gregory Scott Tigges, William Dale Smith
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Patent number: 7162191Abstract: A doctor blade for use with an imaging apparatus includes an elongated member, and a metering surface formed on a portion of the elongated member. The metering surface has surface features, which are modified by buffing the metering surface.Type: GrantFiled: April 1, 2004Date of Patent: January 9, 2007Assignee: Lexmark International, Inc.Inventors: Martin Victor DiGirolamo, David Starling MacMillan, Jody Evan McCoy, Robert Francis Soto, Donald Wayne Stafford
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Patent number: 6990308Abstract: A doctor blade assembly (121) for an image forming device such as a laser printer (100) includes a bracket (622) to which foam (640) is attached providing improved tolerances in the nip formed between the assembly (121) and the doctoring media. The assembly (121) includes a lip (625) which extends under the foam (640) to help secure the foam (640) and reduce the amount of adhesive required to keep the foam (640) attached. The bracket (622) is stamped from a single piece of metal providing a doctor blade assembly (121) with high stiffness that is cost effective to manufacture.Type: GrantFiled: December 14, 2004Date of Patent: January 24, 2006Assignee: Lexmark International, Inc.Inventors: Robert Watson McAlpine, Donald Wayne Stafford, Gregory Scott Tigges
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Patent number: 6481837Abstract: An ink delivery system for an inkjet printing device has an ink cartridge, and a remote ink reservoir for containing a supply of ink. An air purge chamber is provided in flow communication between the reservoir and the cartridge. The air purge chamber includes a vent with a plug of hydrophobic material in the vent, and an outlet to the cartridge. The outlet communicates with a check valve leading to the cartridge. A screen of hydrophilic material is provided in the conduit, with a system for evacuating ink from the system to the reservoir when the printing device is not in use.Type: GrantFiled: August 1, 2001Date of Patent: November 19, 2002Inventors: Benjamin Alan Askren, Ronald Willard Baker, Philip Jerome Heink, Jeffrey Lynn Richie, Donald Wayne Stafford
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Patent number: 6243115Abstract: An ink supply and delivery system for a printer cartridge including a printer cartridge having an interior, at least one air inlet to the interior, and at least one ink outlet from the interior. An air pump is connected to the air inlet of the printer cartridge and creates a positive pressure in the interior of the printer cartridge. The system further includes an ink source, including ink, in the interior of the printer cartridge, the ink source in fluid communication with the ink outlet of the printer cartridge whereby the positive pressure created by the air pump in the interior of printer cartridge forces ink to flow from the ink source in the interior of the printer cartridge through the ink outlet. The ink source is preferably in a resilient container, and the system alternately includes a resilient air container either within, next to, or encapsulating the resilient container of the ink source.Type: GrantFiled: March 9, 2000Date of Patent: June 5, 2001Assignee: Lexmark International, Inc.Inventors: Ronald Willard Baker, Philip Jerome Heink, Jeffrey Lynn Richie, Donald Wayne Stafford
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Patent number: 6145971Abstract: A system and method for supplying ink to a print head on a moving carrier using the acceleration of the print head carrier to assist in pumping the ink. The system includes an ink supply reservoir and an ink pump on the moving carrier where the ink pump has a carrier reservoir including at least one flexible wall that deforms from inertial resistance to acceleration of the moving carrier, a print head, and a pressure regulator in fluid communication with the carrier reservoir and the print head. The system also has an ink supply tube in fluid communication with the ink supply reservoir and the carrier reservoir such that acceleration of the moving carrier and ink pump deforms the flexible wall and thereby pumps ink from the ink supply reservoir to the carrier reservoir and from the carrier reservoir to the print head, or solely to the carrier reservoir.Type: GrantFiled: March 9, 2000Date of Patent: November 14, 2000Assignee: Lexmark International, Inc.Inventors: Ronald Willard Baker, William P. Cook, Philip Jerome Heink, Jeffrey Lynn Richie, Donald Wayne Stafford
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Patent number: 6117557Abstract: A semiconductor developer roller having a conductive shaft and an outer member of caprolactone-ester-based polyurethane loaded with ferric chloride. The members have low environmental sensitivity and good electrical stability.Type: GrantFiled: April 19, 1995Date of Patent: September 12, 2000Assignee: Lexmark International, Inc.Inventors: Johnny Dale Massie, II, Jean Marie Massie, Donald Wayne Stafford, Peter Eric Wallin
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Patent number: 6087011Abstract: An electrophotographic developer roller with a highly resistive layer over a conductive core is made by mixing polyurethane and ferric chloride. After curing, the roller is soaked in hydrogen peroxide to oxidize the outer surface. The oxidized surface layer is electrically resistive. An excellent developer roller is achieved at low production cost.Type: GrantFiled: October 13, 1998Date of Patent: July 11, 2000Assignee: Lexmark International, Inc.Inventors: Bradley Leonard Beach, Todd Lucas Janes, Jean Marie Massie, Donald Wayne Stafford
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Patent number: 6072970Abstract: A charge roller has a steel shaft and conductive outer cylindrical body which is formed by curing with heat a blend comprised of epichlorohydrin rubber, mineral-oil-free zinc oxide dispersion, stearic acid as a lubricant, accelerators and a sulfur donor. The roller has a long useful life and does not express oil while inactive.Type: GrantFiled: October 29, 1996Date of Patent: June 6, 2000Assignee: Lexmark International, Inc.Inventors: William Hargis Barton, Alan Stirling Campbell, Martin Victor DiGirolamo, Donald Wayne Stafford
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Patent number: 5804114Abstract: An electrophotographic developer roller is made by casting urethane prepolymer mixed with a butadiene, a trifunctional curative and ferric chloride powder. After curing, the roller is baked, which oxidizes the outer surface. The oxidized surface layer is electrically resistive, which is desirable in a developer roller. An excellent developer roller is achieved at low production cost.Type: GrantFiled: June 6, 1997Date of Patent: September 8, 1998Assignee: Lexmark International, Inc.Inventors: Todd Lucas Janes, Johnny Dale Massie, II, Joan Marie Massie, Ronald Lloyd Roe, Donald Wayne Stafford
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Patent number: 5797076Abstract: A compliant doctor blade has a metal bar (13) with bottom attached by dual side adhesive tape (15) to a resilient layer of porous foam (7). The bottom of the foam layer is attached by dual side adhesive tape (8) to a shim (1), which is stiff in the direction of movement of the roller (9) which the shim contacts. The shim has a polyester body (3) and a bottom layer (5) containing abrasive grit and conductive carbon black. Finally, the end of the doctor blade is dipped in a conductive paste which hardens into a conductive coating (17) which bridges the conductive layer of the shim and the metal bar. Advantages are reduced costs and improved performance, particularly with respect to streaks from prenip packing.Type: GrantFiled: May 12, 1997Date of Patent: August 18, 1998Assignee: Lexmark International, Inc.Inventors: Peter Wallace Bracken, Jeffery Richard Brener, Martin Victor Digirolamo, Samuel Edward Mullinix, Jr., Donald Wayne Stafford, Peter Eric Wallen
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Patent number: 5707743Abstract: An electrophotographic developer roller is made by casting urethane prepolymer mixed with a butadiene, a trifunctional curative and ferric chloride powder. After curing, the roller is baked, which oxidizes the outer surface. The oxidized surface layer is electrically resistive, which is desirable in a developer roller. An excellent developer roller is achieved at low production cost.Type: GrantFiled: April 9, 1996Date of Patent: January 13, 1998Assignee: Lexmark International, Inc.Inventors: Todd Lucas Janes, Johnny Dale Massie, II, Jean Marie Massie, Ronald Lloyd Roe, Donald Wayne Stafford
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Patent number: 4101224Abstract: Disclosed is a mechanism for replacing the non-escapement magnet normally utilized to inhibit escapement during certain machine functions on a typewriter. A detent arm is connected to the normal pawl knock-off arm so that upon the print shaft rotating and effecting, by a cam thereon, movement of associated linkage and motion of the knock-off arm to disengage the pawl from the ratchet wheel, the detent arm associated with the knock-off arm detents the ratchet wheel and inhibits escapement thereof until the linkage and knock-off arm returns to its normal position by rotation of the print shaft. Thus, if the escapement magnet coil is not energized, the pawl associated with the magnet will return to its normal position and the ratchet wheel will, because of the detent of the member associated with the knock-off arm, be inhibited from motion.Type: GrantFiled: February 18, 1977Date of Patent: July 18, 1978Assignee: International Business Machines CorporationInventors: John Robert Litkenhus, Donald Wayne Stafford