Patents by Inventor Megumi Shimizu

Megumi Shimizu 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).

  • Patent number: 6386668
    Abstract: In an ink jet recording apparatus having two head units, each having a large number of ink nozzles arranged in a line, assembled so that they overlap with each other, an 8-shade image signal is entered into a correction circuit and a line direction position signal is input into a position signal decision circuit. When the position signal decision circuit decides that the position signal represents the overlapping zone of the head units, the shade level of the image signal is divided between the head units. For example, when the shade level of the image signal is 7, one of the head units is allotted the shade level and the other is allotted the shade level. The overlapping nozzles in a pair eject droplets of ink to form one dot.
    Type: Grant
    Filed: June 24, 1999
    Date of Patent: May 14, 2002
    Assignee: Toshiba Tec Kabushiki Kaisha
    Inventors: Megumi Shimizu, Atsushi Kubota, Hidehiro Watanabe, Takahisa Ikeda
  • Patent number: 6378973
    Abstract: An ink jet head is provided having ink chambers, energy-generating elements provided in the ink chambers, respectively, and ink outlet ports communicating with the ink chambers, respectively. The ink jet head may be left unused for a time longer than a predetermined time, with a meniscus formed in each ink outlet port. In this case, a drive pulse is applied to each energy-generating element several times, thereby forcing the ink outwards from the ink outlet ports and increasing a surface area of the ink from a surface area of the meniscus. Then, a negative pressure is applied in each ink chamber, thereby drawing the ink back toward the ink chambers, thus forming a meniscus again in the ink outlet ports. In this condition, a drive pulse is applied to the energy-generating elements, thus ejecting an ink droplet from the ink outlet ports to record data.
    Type: Grant
    Filed: December 8, 1999
    Date of Patent: April 30, 2002
    Assignee: Toshiba Tec Kabushiki Kaisha
    Inventors: Atsushi Kubota, Hidehiro Watanabe, Takahisa Ikeda, Megumi Shimizu
  • Publication number: 20020041315
    Abstract: An ink jet head having ink chambers, energy-generating elements provided in the ink chambers, respectively, and ink outlet ports communicating with the ink chambers, respectively. The ink jet head may be left unused for a time longer than a predetermined time, with a meniscus formed in each ink outlet port. In this case, a drive pulse is applied to each energy-generating element several times, thereby forcing the ink outwards from the ink outlet port and increasing a surface area of the ink from a surface area of the meniscus. Then, a negative pressure is applied in each ink chamber, thereby drawing the ink back toward the ink chamber, thus forming a meniscus again in the ink outlet port. In this condition, a drive pulse is applied to the energy-generating element, thus ejecting an ink droplet from the ink outlet port to record data.
    Type: Application
    Filed: December 3, 2001
    Publication date: April 11, 2002
    Applicant: Toshiba Tec Kabushiki Kaisha
    Inventors: Atsushi Kubota, Hidehiro Watanabe, Takahisa Ikeda, Megumi Shimizu
  • Patent number: 6364445
    Abstract: An image printing apparatus comprises a storage section and a control section. The storage section stores an absorbing speed information in a storage area, the absorption speed information is a measured speed at which a recording medium used for a printing process absorbs an ink used for the printing process. And the control section controls an ink head so as to perform first dot recording which records a plurality of dots on the recording medium by a pitch of an ink ejection opening of the ink head, and moves the recording medium relatively with the ink head and controls the ink head so as to perform second dot recording which records a plurality of dots between a plurality of dots recorded by first dot recording, in accordance with a print interval time determined based on the absorption speed information stored in the storage section.
    Type: Grant
    Filed: June 23, 2000
    Date of Patent: April 2, 2002
    Assignee: Toshiba Tec Kabushiki Kaisha
    Inventors: Takahisa Ikeda, Atsushi Kubota, Hidehiro Watanabe, Megumi Shimizu