Patents by Inventor Takashi Mihara

Takashi Mihara 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: 5487032
    Abstract: A method and apparatus for programming ferroelectric memory cells which reduces fatigue effects of switching polarization of the ferroelectric devices associated with the memory cells such as ferroelectric capacitors and transistors. Alteration of the rise AC fall times associated with signals used to switch ferroelectric device polarization are shown to reduce fatigue of the ferroelectric material thereby increasing the useful life of ferroelectric memory cells. Slowing the rise and fall times as well as the rate of signal level rise and fall, (signal shape), are shown to reduce the fatigue effects of switching polarization of ferroelectric devices. Methods and apparatus for producing a triangular ("sawtooth") signal waveform, a Gaussian signal waveform, and a waveform having exponential rise and fall times are disclosed.
    Type: Grant
    Filed: November 10, 1994
    Date of Patent: January 23, 1996
    Assignees: Symetrix Corporation, Olympus Optical Co., Ltd.
    Inventors: Takashi Mihara, Hitoshi Watanabe, Hiroyuki Yoshimori, Carlos A. Paz de Araujo, Larry D. McMillan
  • Patent number: 5481348
    Abstract: A discharge device is usable for an image forming apparatus including a fixing portion having a heating roller in the shape of a hyperboloid for fixing a toner image formed on an envelope having a turned-up portion, and a stacking portion for stacking envelopes. The discharge device provided with a discharge roller system provided between the fixing portion and the stacking portion to discharge the envelope to the stacking portion has a upright portion provided near the discharge roller system below the transport path of the envelope to prevent the turned-up portion of the envelope from warping downward. This discharge device prevents a discharging envelope from coming into contact or colliding with the uppermost one of a stack of already discharged envelopes on the stacking portion, and enables the envelopes to be discharged suitably and to be stacked orderly on the stacking portion and increases an amount of envelopes stacked on the stacking portion.
    Type: Grant
    Filed: October 1, 1993
    Date of Patent: January 2, 1996
    Assignee: Mita Industrial Co., Ltd.
    Inventors: Takashi Mihara, Kazumi Shirasaka, Kenji Oda, Akinobu Nakahata, Masahiro Shinohara, Wataru Sasaki
  • Patent number: 5471363
    Abstract: A ferroelectric capacitive element according to the present invention includes a substrate constituted by a silicon oxide, glass, or the like, an adhesive layer of Ti or the like formed on the substrate, a lower electrode formed on the adhesive layer and constituted by any one of Pt, Pd, Ag, Au and the like, a ferroelectric film 14 formed on the lower electrode, a conductive oxide film formed on the ferroelectric film, and an upper electrode formed on the conductive oxide film and constituted by a metallic material other than precious metal, such as Al, Al alloy, AlSi, AlNi, Ni alloy, Cu alloy, AlCu.
    Type: Grant
    Filed: September 19, 1994
    Date of Patent: November 28, 1995
    Assignees: Olympus Optical Co., Ltd., Symetrix Corporation
    Inventor: Takashi Mihara
  • Patent number: 5468684
    Abstract: A method of fabricating a ferroelectric or layered superlattice DRAM compatible with conventional silicon CMOS technology. A MOSFET is formed on a silicon substrate. A thick layer of BPSG followed by a thin SOG layer overlies the MOSFET. A capacitor is formed by depositing a layer of platinum, annealing, depositing an intermediate layer comprising a ferroelectric or layered superlattice material, annealing, depositing a second layer of platinum, then patterning the capacitor. Another SOG layer is deposited, contact holes to the MOSFET and capacitor are partially opened, the SOG is annealed, the contact holes are completely opened, and a Pt/Ti/PtSi wiring layer is deposited.
    Type: Grant
    Filed: May 21, 1993
    Date of Patent: November 21, 1995
    Assignees: Symetrix Corporation, Olympus Optical Co., Ltd.
    Inventors: Hiroyuki Yoshimori, Hitoshi Watanabe, Carlos A. Paz De Araujo, Shuzo Hiraide, Takashi Mihara, Larry D. McMillan
  • Patent number: 5466629
    Abstract: An oversize ferroelectric capacitor is located against the contact hole to the MOSFET source/drain in a DRAM. A barrier layer made of titanium nitride, titanium tungsten, tantalum, titanium, tungsten, molybdenum, chromium, indium tin oxide, tin dioxide, ruthenium oxide, silicon, silicide, or polycide lies between the ferroelectric layer and the source drain. The barrier layer may act as the bottom electrode of the ferroelectric capacitor, or a separate bottom electrode made of platinum may be used. In another embodiment in which the barrier layer forms the bottom electrode, an oxide layer less than 5 nm thick is located between the barrier layer and the ferroelectric layer and the barrier layer is made of silicon, silicide, or polycide. A thin silicide layer forms and ohmic contact between the barrier layer and the source/drain. The capacitor and the barrier layer are patterned in a single mask step. The ends of the capacitor are stepped or tapered.
    Type: Grant
    Filed: February 3, 1995
    Date of Patent: November 14, 1995
    Assignees: Symetrix Corporation, Olympus Optical Co., Ltd.
    Inventors: Takashi Mihara, Hiroyuki Yoshimori, Hitoshi Watanabe, Larry D. McMillan, Carlos P. De Araujo
  • Patent number: 5439845
    Abstract: A liquid precursor containing a metal is applied to a substrate, RTP baked, and annealed to form a layered superlattice material. Prebaking the substrate and oxygen in the RTP and anneal is essential, except for high bismuth content precursors. Excess bismuth between 110% and 140% of stoichiometry and RTP temperature of 725.degree. C. is optimum. The film is formed in two layers, the first of which uses a stoichiometric precursor and the second of which uses an excess bismuth precursor. The electronic properties are so regularly dependent on process parameters and material composition, and such a wide variety of materials are possible, that electronic devices can be designed by selecting from a continuous record of the values of one or more electronic properties as a continuous function of the process parameters and material composition, and utilizing the selected process and material composition to make a device.
    Type: Grant
    Filed: December 5, 1994
    Date of Patent: August 8, 1995
    Assignees: Olympus Optical Co., Ltd., Symetrix Corporation
    Inventors: Hitoshi Watanabe, Carlos A. Paz De Araujo, Hiroyuki Yoshimori, Michael C. Scott, Takashi Mihara, Joseph D. Cuchiaro, Larry D. McMillan
  • Patent number: 5434102
    Abstract: A liquid precursor containing a metal is applied to a substrate, RTP baked, and annealed to form a layered superlattice material. Prebaking the substrate and oxygen in the RTP and anneal is essential, except for high bismuth content precursors. Excess bismuth between 110% and 140% of stoichiometry and RTP temperature of 725.degree. C. is optimum. The film is formed in two layers, the first of which uses a stoichiometric precursor and the second of which uses an excess bismuth precursor. The electronic properties are so regularly dependent on process parameters and material composition, and such a wide variety of materials are possible, that electronic devices can be designed by selecting from a continuous record of the values of one or more electronic properties as a continuous function of the process parameters and material composition, and utilizing the selected process and material composition to make a device.
    Type: Grant
    Filed: May 21, 1993
    Date of Patent: July 18, 1995
    Assignees: Symetrix Corporation, Olympus Optical Co., Ltd.
    Inventors: Hitoshi Watanabe, Carlos A. Paz De Araujo, Hiroyuki Yoshimori, Michael C. Scott, Takashi Mihara, Joseph D. Cuchiaro, Larry D. McMillan
  • Patent number: 5430534
    Abstract: A copy item transport device is used in an image forming apparatus having an image bearing member and a pair of registration rollers before the image bearing member, and includes a separator for regulating multiple copy items to one copy item for each image formation. The separator is constructed by a forward roller being driven in a forward direction of transporting the copy item to the registration roller pair, a reverse roller in contact with the forward roller. The reverse roller is driven in a reverse direction of transporting the copy item backward, but rotatable in the forward direction together with the forward roller when receiving a greater transmitted forward torque from the forward roller than the reverse torque. The reverse drive to the reverse roller is stopped at the same time or after the forward drive to the forward roller is stopped to assure the nip of copy item by the registration roller pair.
    Type: Grant
    Filed: October 1, 1993
    Date of Patent: July 4, 1995
    Assignee: Mita Industrial Co., Ltd.
    Inventors: Kazumi Shirasaka, Akinobu Nakahata, Masahiro Shinohara, Kenji Oda, Takashi Mihara, Wataru Sasaki
  • Patent number: 5406510
    Abstract: A non-volatile memory includes a constant voltage source, a bit line, a memory cell having a first ferroelectric capacitor connected between the bit line and the constant voltage source, a source of a reference voltage, and a latch connected between the bit line and the reference voltage. The latch drives the bit line to the same logic state as the ferroelectric capacitor to read and rewrite the capacitor in a single operation. The reference voltage is provided by a ferroelectric dummy capacitor having an area smaller than the area of the first capacitor but greater than 1/2 the area of the first capacitor.
    Type: Grant
    Filed: July 15, 1993
    Date of Patent: April 11, 1995
    Assignees: Symetrix Corporation, Olympus Optical Co., Ltd.
    Inventors: Takashi Mihara, Carlos A. Paz De Araujo, Larry D. McMillan
  • Patent number: 5405129
    Abstract: A detecting device is adapted for detecting the presence of an item and includes a shaft rotatably supported on a frame, a first contacting member attached to the shaft and operable to come into contact with an item; a second contacting member attached to the shaft and operable to come into contact with an item, the second contacting member being spaced away from the first contacting member in an axial direction of the shaft by a specified distance, a pivotal member, a detector for detecting whether the pivotal member is at a specified detecting position, and a transmission device for transmitting a rotation of either the first or second contacting member to the pivotal member to rotate the pivotal member to the specified detecting position.
    Type: Grant
    Filed: November 3, 1993
    Date of Patent: April 11, 1995
    Assignee: Mita Industrial Co., Ltd.
    Inventors: Takashi Mihara, Seiji Kikuchi, Masaki Tsuchiya, Junichiro Higuma, Hiromi Okada