Patents by Inventor Noriaki Okazawa

Noriaki Okazawa 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: 6296351
    Abstract: In order to ease the discharge of air bubbles stagnated in end portions of a reservoir in an ink jet recording head, the end portions of the reservoir are so formed that the widths thereof are substantially equal to the depths thereof. Air bubbles entered in those portions are drawn into pressure generating chambers by directly applying negative pressure to discharge outwards from nozzle orifices.
    Type: Grant
    Filed: August 11, 1999
    Date of Patent: October 2, 2001
    Assignee: Seiko Epson Corporation
    Inventors: Ryoichi Tanaka, Tsuyoshi Kitahara, Noriaki Okazawa, Hitotoshi Kimura, Takayuki Iijima
  • Patent number: 6217159
    Abstract: An ink jet printing device supplies first and second signals to cause a pressure generating chamber to jet out ink droplets. A third signal is applied to the pressure generating chamber to effectively attenuate the kinetic energy of the meniscus and to hold the meniscus at a position suitable for jetting out the next ink droplet to provide a stable print output. Also, an ink-jet recording apparatus is provided with a control means for controlling the timing of the start of the second signal and the timing of the start of the third signal according to the environmental temperature. In the ink-jet recording apparatus, the discharge speed of ink drops is made constant by regulating the start time of the second signal so as to make constant the drawing position of a meniscus when the ink drops are discharged.
    Type: Grant
    Filed: July 9, 1997
    Date of Patent: April 17, 2001
    Assignee: Seiko Epson Corporation
    Inventors: Koji Morikoshi, Tsuyoshi Kitahara, Kaoru Momose, Noriaki Okazawa, Masahiko Yoshida, Kazunaga Suzuki, Takahiro Katakura, Toshiki Usui
  • Patent number: 6139132
    Abstract: A pressurizing chamber 1 is formed as a recess by half etching of a silicon single-crystal substrate 2. A nozzle communicating hole 6 through which the pressurizing chamber 1 is connected to a nozzle opening 5 is formed as a through hole which is smaller in width than the pressurizing chamber 1. The pressurizing chamber 1 is connected to the nozzle opening 5 in the other face via the nozzle communicating hole 6 while reducing the volume of the pressurizing chamber 1 to a degree as small as possible. The silicon single-crystal substrate is used as a member constituting a spacer so that an ink drop of a reduced ink amount suitable for high density printing files with high positioning accuracy.
    Type: Grant
    Filed: September 5, 1996
    Date of Patent: October 31, 2000
    Assignee: Seiko Epson Corporation
    Inventors: Shinji Yasukawa, Minoru Usui, Takahiro Naka, Tsuyoshi Kitahara, Noriaki Okazawa, Hideaki Sonehara
  • Patent number: 6048053
    Abstract: An ink jet recording head having high printing quality which is achieved independently of ambient temperature changes. An overhang portion (22) is formed on a surface of a frame (20) in such a manner that the overhang portion extends close to an island portion (9) of a resilient plate. A front end (17) of a fixed board (14) is fixed to the overhang portion (22) so that a gap (23) is interposed between a lateral side of the fixed board (14) and the frame (20). The piezoelectric vibration elements (8) are secured to the opposite end of the fixed board and abut against each of the island portions. The thickness (L0) of the overhang portion (22) affects that thermal expansion differential derived from a difference in the materials of the frame (20) and the piezoelectric vibration element. Since the thickness is minimized, the thermal expansion differential between the frame (20) and the piezoelectric vibration elements (8) is correspondingly minimized.
    Type: Grant
    Filed: July 25, 1995
    Date of Patent: April 11, 2000
    Assignee: Seiko Epson Corporation
    Inventors: Kazumi Kamoi, Noriaki Okazawa, Kazunaga Suzuki, Minoru Usui, Hiromi Mimura, Manabu Nagawatari
  • Patent number: 5710584
    Abstract: An ink jet recording head formed by laminating and fixing: a flow path forming plate having through holes for defining pressure producing chambers, ink supply inlets, and a common ink chamber, a nozzle plate having nozzle openings communicating with the pressure producing chambers, and a vibration plate having diaphragm portions that are resiliently deformed in response to displacement of piezoelectric vibration elements one upon another with an adhesive so as to be watertight. The vibration plate has frame-like thick wall portions that extend as far as to the ink supply inlet side of the pressure producing chamber as well as to the inner side of the nozzle opening, and portions closer to a piezoelectric vibration element than to both ends of the pressure producing chamber are made to be supported by a base. As a result of this construction, a nonsupported region of the pressure producing chamber can be shortened, which in turn improves the rigidity of a substrate unit as a whole.
    Type: Grant
    Filed: November 29, 1994
    Date of Patent: January 20, 1998
    Assignee: Seiko Epson Corporation
    Inventors: Kazunaga Suzuki, Minoru Usui, Noriaki Okazawa, Kazuhiko Miura, Takahiro Naka
  • Patent number: 5548314
    Abstract: An ink jet recording head for ejecting ink drops by expanding or shrinking a pressure generation chamber of an ink flow route forming member consisting of nozzle openings, the pressure generation chamber, an ink supply port, and a reservoir. Piezoelectric vibrators are disposed and fixed in a row with a predetermined pitch, to a piezoelectric vibrator support plate having excellent cutting properties and the piezoelectric vibrator support plate is fixed to a base made of material having a larger rigidity than the support plate. If the piezoelectric vibrator support plate receives reaction forces when ink is ejected, the base having a larger rigidity than the support plate resists the reaction force and suppresses undesired displacement of the contiguous piezoelectric vibrators.
    Type: Grant
    Filed: May 12, 1994
    Date of Patent: August 20, 1996
    Assignee: Seiko Epson Corporation
    Inventors: Noriaki Okazawa, Takahiro Naka, Shinji Yasukawa
  • Patent number: 5157420
    Abstract: An inkjet recording head having a head substrate (1); at least a group of pressure chambers (2) arranged so as to be recessed over an entire surface of the head substrate; ink ejecting nozzles (7), each of which is opened so as to face a surface opposite to that of the substrate by extending through a flow path (5) that passes through the head substrate thicknesswise from one end of each of the pressure chambers; and an annular ink preparation chamber (4) communicating with the other end of each of the pressure chambers. The ink preparation chamber that communicates with each of the pressure chambers is arranged so as to be annular, thereby improving the air bubble discharging characteristics and preventing disruption of ink ejection. In addition, the advantage that the ink can be supplied to each of the ink ejecting nozzles uniformly ensures excellent printing quality. Furthermore, the ink chamber is recessed into an opposite surface of the head substrate opposite the pressure chambers.
    Type: Grant
    Filed: August 15, 1990
    Date of Patent: October 20, 1992
    Inventors: Takahiro Naka, Kazuhiko Hara, Noriaki Okazawa, Seiji Mochizuki