Patents by Inventor May F. Ho
May F. Ho 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: 5638101Abstract: Described is an inkjet print cartridge including an ink reservoir; a substrate having a plurality of individual ink firing chambers with an ink firing element in each chamber; said ink firing chambers arranged in a first chamber array and a second chamber array and said firing chambers spaced so as to provide 600 dots per inch printing; an ink channel connecting said reservoir with said ink firing chambers, said channel including a primary channel connected at a first end with said reservoir and at a second end to a secondary channel; a separate inlet passage for each firing chamber connecting said secondary channel with said firing chamber for allowing high frequency refill of the firing chamber; a group of said firing chambers in adjacent relationship forming a primitive in which only one firing chamber in said primitive is activated at a time; a first circuit on said substrate connected to said firing elements; and a second circuit on said cartridge connected to said first circuit, for transmitting firingType: GrantFiled: October 6, 1994Date of Patent: June 10, 1997Assignee: Hewlett-Packard CompanyInventors: Brian J. Keefe, May F. Ho, Kenneth J. Courian, Steven W. Steinfield, Winthrop D. Childers, Ellen R. Tappon, Kenneth E. Trueba, Terri I. Chapman, William R. Knight, Jules G. Moritz, III
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Self-cooling printhead structure for inkjet printer with high density high frequency firing chambers
Patent number: 5619236Abstract: Disclosed is an inkjet print cartridge having an ink reservoir; a substrate having a plurality of individual ink firing chambers with an ink firing element in each chamber along a top surface of the substrate and having a first outer edge along a periphery of substrate; the first outer edge being in close proximity to the ink firing chambers. The ink firing chambers are arranged in a first chamber array and a second chamber array and with the firing chambers spaced so as to provide 600 dots per inch printing. An ink channel connects the reservoir with the ink firing chambers, the channel including a primary channel connected at a first end with the reservoir and at a second end to a secondary channel; the primary channel allowing ink to flow from the ink reservoir, around the first outer edge of the substrate to the secondary channel along the top surface of the substrate so as to be proximate to the ink firing chambers.Type: GrantFiled: May 15, 1996Date of Patent: April 8, 1997Assignee: Hewlett-Packard CompanyInventors: Brian J. Keefe, May F. Ho, Kenneth J. Courian, Steven W. Steinfield, Winthrop D. Childers, Ellen R. Tappon, Kenneth E. Trueba, Terri I. Chapman, William R. Knight, Jules G. Moritz, III -
Patent number: 5604519Abstract: Described is an ink delivery system for an array of nozzle orifices in a print cartridge comprising an ink reservoir; a substrate having a plurality of individual ink firing chambers with an ink firing element in each chamber; an ink channel connecting said reservoir with said ink firing chambers, said channel including a primary channel connected at a first end with said reservoir and at a second end to a secondary channel; a separate inlet passage for each firing chamber connecting said secondary channel with said firing chamber for allowing high frequency refill of the firing chamber; a group of said firing chambers in adjacent relationship forming a primitive in which only one firing chamber in said primitive is activated at a time; first circuit means on said substrate connected to said firing elements; and second circuit means on said cartridge connected to said first circuit means, for transmitting firing signals to said ink firing elements at a frequency greater than 9 kHz.Type: GrantFiled: October 6, 1994Date of Patent: February 18, 1997Assignee: Hewlett-Packard CompanyInventors: Brian J. Keefe, May F. Ho, Kenneth J. Courian, Steven W. Steinfield, Winthrop D. Childers, Ellen R. Tappon, Kenneth E. Trueba, Terri I. Chapman, William R. Knight, Jules G. Moritz
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Patent number: 5594481Abstract: Disclosed is an inkjet print cartridge including an ink reservoir; a substrate having a plurality of individual ink firing chambers with an ink firing element in each chamber along a top surface of said substrate and having a first outer edge along a periphery of substrate; the first outer edge being in close proximity to the ink firing chambers. The ink firing chambers are arranged in a first chamber array and a second chamber array and with the firing chambers spaced so as to provide 600 dots per inch printing. An ink channel connects the reservoir with the ink firing chambers, the channel including a primary channel connected at a first end with the reservoir and at a second end to a secondary channel; the primary channel allowing ink to flow from the ink reservoir, around the first outer edge of the substrate to the secondary channel along the top surface of the substrate so as to be proximate to the ink firing chambers.Type: GrantFiled: October 6, 1994Date of Patent: January 14, 1997Assignee: Hewlett-Packard CompanyInventors: Brian J. Keefe, May F. Ho, Kenneth J. Courian, Steven W. Steinfield, Winthrop D. Childers, Ellen R. Tappon, Kenneth E. Trueba, Terri I. Chapman, William R. Knight, Jules G. Moritz, III
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Patent number: 5563642Abstract: Disclosed is an inkjet print cartridge having an ink reservoir; a substrate having a plurality of individual ink firing chambers with an ink firing element in each chamber along a top surface of the substrate and having a first outer edge along a periphery of substrate; the first outer edge being in close proximity to the ink firing chambers. The ink firing chambers are arranged in a first chamber array and a second chamber array and with the firing chambers spaced so as to provide 600 dots per inch printing. An ink channel connects the reservoir with the ink firing chambers, the channel including a primary channel connected at a first end with the reservoir and at a second end to a secondary channel; the primary channel allowing ink to flow from the ink reservoir, around the first outer edge of the substrate to the secondary channel along the top surface of the substrate so as to be proximate to the ink firing chambers.Type: GrantFiled: October 6, 1994Date of Patent: October 8, 1996Assignee: Hewlett-Packard CompanyInventors: Brian J. Keefe, May F. Ho, Kenneth J. Courian, Steven W. Steinfield, Winthrop D. Childers, Ellen R. Tappon, Kenneth E. Trueba, Terri I. Chapman, William R. Knight, Jules G. Moritz, III
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Patent number: 5463413Abstract: A "barrier reef" configuration, comprising a plurality of cays, or pillars, is provided, each pillar associated with the entrance to a firing chamber in a thermal ink-jet printhead. Each firing chamber is formed in a photopolymer layer, together with an associated barrier inlet channel that fluidically communicates with a common ink refill channel which acts as a common reservoir to the each firing chamber, in which resides a resistor element. When energized, the resistor element fires a droplet of ink toward a print medium. Over each resistor element is a nozzle, formed in an orifice plate, for firing the droplets of ink orthogonal to the resistor element. The pillars, which are positioned near the ink refill channel, serve to support the orifice plate and act as pillars between the substrate and the orifice plate, thereby avoiding any pinching effect that would otherwise occur for an unsupported region.Type: GrantFiled: June 3, 1993Date of Patent: October 31, 1995Assignee: Hewlett-Packard CompanyInventors: May F. Ho, Ellen Tappon
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Patent number: 5109234Abstract: A thermal technique for reducing print density shifts due to print wait time in thermal ink jet printers. The ink jet firing resistors of the printhead are driven with warming pulses having a pulse width insufficient to cause ink drop firing at the warming pulse frequency. They are driven for an interval that depends on the amount of time that has elapsed since printing by the printhead last occurred, or an interval that depends on the amount of decrease in the printhead temperature since printing stopped. In a particular embodiment of the printhead warming technique, the warming pulses have the same amplitude as the ink drop firing pulses, and a higher frequency.Type: GrantFiled: September 14, 1990Date of Patent: April 28, 1992Assignee: Hewlett-Packard CompanyInventors: David R. Otis, Jr., May F. Ho