Patents by Inventor Takayoshi Akao

Takayoshi Akao 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: 7474060
    Abstract: A light source has a light emission section comprising a two-dimensional array of electron emitters and a drive circuit for applying a drive voltage to each of the electron emitters of the light emission section. The drive circuit applies the drive voltage between upper and lower electrodes of each of the electron emitters based on a control signal representative of turn-on/turn-off from an external source (a turn-on/turn-off switch or the like), for thereby controlling each of the electron emitters. Each of the electron emitters has a plate-like emitter, an upper electrode disposed on a face side of the emitter, and a lower electrode disposed on a reverse side of the emitter.
    Type: Grant
    Filed: August 16, 2004
    Date of Patent: January 6, 2009
    Assignee: NGK Insulators, Ltd.
    Inventors: Yukihisa Takeuchi, Tsutomu Nanataki, Iwao Ohwada, Takayoshi Akao
  • Patent number: 7379037
    Abstract: One image is displayed in a period as one frame, which includes one charge accumulation period and one light emission period. In the charge accumulation period, all electron emitters are scanned, and voltages depending on the luminance levels of corresponding pixels are applied to the electron emitters which correspond to pixels to be turned on (to emit light), to accumulate charges (electrons) in amounts depending on the luminance levels of corresponding pixels in the electron emitters which correspond to pixels to be turned on. In the next light emission period, a constant voltage is applied to all the electron emitters to emit electrons in amounts depending on the luminance levels of corresponding pixels from the electron emitters which correspond to pixels to be turned on, thereby emitting light from the pixels to be turned on.
    Type: Grant
    Filed: March 24, 2004
    Date of Patent: May 27, 2008
    Assignee: NGK Insulators, Ltd.
    Inventors: Yukihisa Takeuchi, Tsutomu Nanataki, Iwao Ohwada, Takayoshi Akao
  • Patent number: 7336026
    Abstract: An electron emitter has an emitter made of a dielectric material and an upper electrode and a lower electrode for being supplied with a drive voltage for emitting electrons. The upper electrode is disposed on an upper surface of the emitter, and the lower electrode is disposed on a lower surface of the emitter. The upper electrode has a plurality of through regions through which the emitter is exposed. Each of the through regions of the upper electrode has a peripheral portion having a surface facing the emitter and spaced from the emitter.
    Type: Grant
    Filed: September 27, 2004
    Date of Patent: February 26, 2008
    Assignee: NGK Insulators, Ltd.
    Inventors: Yukihisa Takeuchi, Tsutomu Nanataki, Iwao Ohwada, Takayoshi Akao
  • Patent number: 7304440
    Abstract: An electron emitting apparatus includes a lower electrode, an emitter section made of a dielectric material, a plurality of upper electrodes having micro through holes, and a collector electrode opposing the upper electrodes. In this electron-emitting apparatus, electrons are accumulated in the emitter section by controlling the potential difference (drive voltage) between the lower and upper electrodes with respect to the potential of the lower electrode to a negative predetermined voltage. At this time, the collector electrode of the electron-emitting apparatus is grounded. Thus, unnecessary electron-emitting is suppressed. Subsequently, the drive voltage is changed to a positive predetermined voltage. As a result, polarization reversal occurs in the emitter section, and accumulated electros are emitted through the micro through holes in the upper electrodes by Coulomb repulsion. At this time, a positive voltage Vc is applied to the collector electrode to give large energy to accelerate the electrons.
    Type: Grant
    Filed: September 27, 2005
    Date of Patent: December 4, 2007
    Assignee: NGK Insulators, Ltd.
    Inventors: Iwao Ohwada, Takayoshi Akao, Tetsuyuki Kameji, Hirokazu Nakamura
  • Publication number: 20070222393
    Abstract: The electron emitting device 10 includes a substrate 11, a lower electrode 12, an emitter section 13, an upper electrode 14. The upper electrode disposed above the emitter section to oppose the lower electrode so as to sandwich the emitter section with the lower electrode. The upper electrode has a plurality of micro through holes. The upper electrode is configured in such a manner that distance t1 (gap distance t1) between the lower surface of the upper electrode in the vicinity of the micro through holes 14c and the upper surface of the emitter section is substantially constant for any of the micro through holes.
    Type: Application
    Filed: September 29, 2006
    Publication date: September 27, 2007
    Applicant: NGK Insulators, Ltd.
    Inventors: Iwao Ohwada, Takayoshi Akao
  • Publication number: 20070188418
    Abstract: An electron-emitting apparatus includes an electron-emitting element having a lower electrode, a dielectric emitter section, upper electrodes having micro through holes, and a circuit for applying a drive voltage Vin between the lower and upper electrodes. The drive voltage is applied between the lower and upper electrodes to set an element voltage Vka, which is a potential of the upper electrode relative to a potential of the lower electrode, at a negative voltage for a charge accumulation period Td to accumulate electrons in the emitter section, and to set the element voltage Vka at a predetermined positive voltage for an electron emission period Th to emit electrons from the emitter section. The drive voltage applying circuit stepwise increases the positive voltage during the electron emission period Th and separately emits the electrons accumulated in the emitter section a plurality of times.
    Type: Application
    Filed: October 14, 2005
    Publication date: August 16, 2007
    Applicant: NGK Insulators, Ltd.
    Inventors: Iwao Ohwada, Takayoshi Akao, Naoki Goto, Tomohiko Sugiyama
  • Patent number: 7230371
    Abstract: A light source has a rear glass substrate and a front glass substrate having a plate surface disposed in facing relation to a principal surface of the rear glass substrate. The plate surface of the front glass substrate is coated with a phosphor. A two-dimensional array of electron emitters is disposed on the principal surface of the rear glass substrate. A space defined between the rear glass substrate and the front glass substrate is filled with a gas. The gas may be an Hg (mercury) gas or an Xe (xenon) gas.
    Type: Grant
    Filed: March 17, 2005
    Date of Patent: June 12, 2007
    Assignee: NGK Insulators, Ltd.
    Inventors: Yukihisa Takeuchi, Tsutomu Nanataki, Iwao Ohwada, Takayoshi Akao
  • Publication number: 20070040130
    Abstract: An electron beam irradiating apparatus includes a chamber being kept under vacuum, and housing a planar electron emitting element and a positioning unit and an object to be irradiated is directly irradiated with an electron beam emitted from the element. The planar electron emitting element includes: an emitter portion composed of a dielectric material; and a first electrode and a second electrode applied with a driving voltage for emitting electrons, and the first electrode is formed on a first surface of the emitter portion and has a plurality of through-holes where the emitter portion is exposed, a surface of the first electrode facing to the emitter portion around the through-holes is separated from the emitter portion, and the electron beam is emitted from the first surface of the emitter portion through the through-holes.
    Type: Application
    Filed: March 21, 2006
    Publication date: February 22, 2007
    Applicant: NGK Insulators, Ltd.
    Inventors: Tsutomu Nanataki, Iwao Ohwada, Yuki Bessho, Takayoshi Akao
  • Patent number: 7176609
    Abstract: An electron emitter has an emitter made of a dielectric material, and an upper electrode and a lower electrode to which a drive voltage is applied to emit electrons. The upper electrode is formed on a first surface of the substance serving as the emitter, and the lower electrode is formed on a second surface of the substance serving as the emitter. The upper electrode has a plurality of through regions through which the emitter is exposed. The upper electrode has a surface which faces the emitter in peripheral portions of the through regions and which is spaced from the emitter.
    Type: Grant
    Filed: December 8, 2003
    Date of Patent: February 13, 2007
    Assignee: NGK Insulators, Ltd.
    Inventors: Yukihisa Takeuchi, Tsutomu Nanataki, Iwao Ohwada, Takayoshi Akao
  • Patent number: 7141915
    Abstract: An actuator device has a drive section including a plurality of actuators arranged in a plane on a substrate, and a single first plate member to which drive forces from the actuators of the drive section are transmitted. A plurality of spacers are disposed between the first plate member and the substrate, forming m cells. Each of the actuators has a cavity, a vibrating section and a fixed section formed on the substrate. The rigidity of the first plate member is greater than the rigidity of the vibrating section of the actuator.
    Type: Grant
    Filed: July 22, 2004
    Date of Patent: November 28, 2006
    Assignee: NGK Insulators, Ltd.
    Inventors: Yukihisa Takeuchi, Tsutomu Nanataki, Koji Kimura, Natsumi Shimogawa, Takayoshi Akao
  • Patent number: 7109962
    Abstract: A display device has drive circuits each having a logic gate for inhibiting the inputting of a data signal from a signal line when unselected and permitting the inputting of a data signal from the signal line when selected, based on a drive signal (select voltage) applied from a select line, a capacitor for holding the output of the logic gate when selected and outputting the held output as a control voltage, and a drive voltage generating circuit for generating a drive voltage for displacing the actuator based on the control voltage from the capacitor.
    Type: Grant
    Filed: March 25, 2003
    Date of Patent: September 19, 2006
    Assignee: NGK Insulators, Ltd.
    Inventors: Yukihisa Takeuchi, Tsutomu Nanataki, Iwao Ohwada, Yasuharu Kuno, Takayoshi Akao
  • Publication number: 20060197413
    Abstract: An actuator device has a drive section including a plurality of actuators arranged in a plane on a substrate, and a single first plate member to which drive forces from the actuators of the drive section are transmitted. A plurality of spacers are disposed between the first plate member and the substrate, forming m cells. Each of the actuators has a cavity, a vibrating section and a fixed section formed on the substrate. The rigidity of the first plate member is greater than the rigidity of the vibrating section of the actuator.
    Type: Application
    Filed: July 22, 2004
    Publication date: September 7, 2006
    Applicant: NGK Insulators, Ltd.
    Inventors: Yukihisa Takeuchi, Tsutomu Nanataki, Koji Kimura, Natsumi Shimogawa, Takayoshi Akao
  • Publication number: 20060132024
    Abstract: An electron-emitting apparatus includes an emitter section made of a dielectric material, lower electrodes, upper electrodes having micro through holes, insulating layers disposed on the upper surface of the emitter section and between the adjacent upper electrodes, and focusing electrodes to which a predetermine potential is applied and which are disposed on the insulating layers. The electron-emitting apparatus applies a negative potential to the upper electrode to accumulate electrons in the emitter section and then applies a positive potential to the upper electrode. As a result, the polarization of the emitter section is reversed, and the accumulated electrons are emitted through the micro through holes in the upper electrodes by Coulomb repulsion. Owing to electric fields generated by the focusing electrodes, the emitted electrons travel in the upward direction of the upper electrode without spreading into a shape of a cone.
    Type: Application
    Filed: September 12, 2005
    Publication date: June 22, 2006
    Applicant: NGK Insulators, Ltd.
    Inventors: Tsutomu Nanataki, Iwao Ohwada, Takayoshi Akao, Hirokazu Nakamura
  • Publication number: 20060132052
    Abstract: An electron-emitting apparatus includes an electron-emitting element having a lower electrode, an emitter section having a dielectric material, and a plurality of upper electrodes having micro through holes, and a drive voltage applying circuit having a circuit for applying a drive voltage Vin between the lower electrode and the upper electrode. The drive voltage applying circuit applies a drive voltage between the lower electrode and the upper electrode to set an element voltage Vka, which is a potential of the upper electrode relative to a potential of the lower electrode, at a negative voltage for a charge accumulation period Td so as to accumulate electrons in the emitter section, and to set the element voltage Vka at a predetermined positive voltage for an electron emission period Th so as to emit electrons from the emitter section.
    Type: Application
    Filed: September 16, 2005
    Publication date: June 22, 2006
    Applicant: NGK Insulators, Ltd.
    Inventors: Iwao Ohwada, Takayoshi Akao, Naoki Goto, Tomohiko Sugiyama
  • Publication number: 20060118827
    Abstract: An electron emitting apparatus includes a lower electrode, an emitter section made of a dielectric material, a plurality of upper electrodes having micro through holes, and a collector electrode opposing the upper electrodes. In this electron-emitting apparatus, electrons are accumulated in the emitter section by controlling the potential difference (drive voltage) between the lower and upper electrodes with respect to the potential of the lower electrode to a negative predetermined voltage. At this time, the collector electrode of the electron-emitting apparatus is grounded. Thus, unnecessary electron-emitting is suppressed. Subsequently, the drive voltage is changed to a positive predetermined voltage. As a result, polarization reversal occurs in the emitter section, and accumulated electros are emitted through the micro through holes in the upper electrodes by Coulomb repulsion. At this time, a positive voltage Vc is applied to the collector electrode to give large energy to accelerate the electrons.
    Type: Application
    Filed: September 27, 2005
    Publication date: June 8, 2006
    Applicant: NGK Insulators, Ltd.
    Inventors: Iwao Ohwada, Takayoshi Akao, Tetsuyuki Kameji, Hirokazu Nakamura
  • Publication number: 20060113608
    Abstract: An electron-emitting device includes an emitter section composed of a dielectric material, a lower electrode disposed on the lower side of the emitter section, and an upper electrode disposed on the upper side of the emitter section so as to be opposed to the lower electrode with the emitter section therebetween, electrons being emitted from the emitter section through the upper electrode by the application of a drive voltage between the lower electrode and the upper electrode, wherein the upper electrode is provided with a plurality of through-holes which expose the emitter section and which have an average diameter of 10 nm or more and less than 100 nm, and a peripheral portion of each through-hole facing the emitter section is separated at a predetermined distance from the emitter section.
    Type: Application
    Filed: November 29, 2005
    Publication date: June 1, 2006
    Applicant: NGK Insulators, Ltd.
    Inventors: Iwao Ohwada, Masao Takahashi, Takayoshi Akao, Shuichi Ozawa, Kei Kosaka
  • Publication number: 20060082318
    Abstract: An electron-emitting element has an electron emission unit including a lower electrode, an emitter section composed of a dielectric material, and an upper electrode having a plurality of micro through holes; and a power supply for applying a power supply voltage to the electron emission unit. During the period between the point at which emission of electrons accumulated in the emitter section is started and the point at which the electron emission is completed, the power supply generates a first power supply voltage, whose absolute value changes with forming a sinusoidal wave so that the potential of the upper electrode is higher than the potential of the lower electrode.
    Type: Application
    Filed: September 27, 2005
    Publication date: April 20, 2006
    Applicant: NGK Insulators, Ltd.
    Inventors: Iwao Ohwada, Takayoshi Akao, Tetsuyuki Kameji, Hirokazu Nakamura
  • Publication number: 20060082317
    Abstract: An electron-emitting apparatus includes an element having a lower electrode, an emitter section composed of a dielectric material, and an upper electrode having a plurality of micro through holes: and a drive voltage applying circuit having a power supply and a circuit that applies a voltage generated by the power supply between the lower electrode and the upper electrode. In order to emit electrons accumulated in the emitter section, the power supply generates a voltage gradually increasing from a first voltage to a second voltage. In order to accumulate electrons In the emitter section, the power supply generates a voltage gradually decreasing from the second voltage to the first voltage. A rapid change in element voltage and excessive element current can thereby be avoided, and unnecessary electron emission can be prevented.
    Type: Application
    Filed: September 26, 2005
    Publication date: April 20, 2006
    Applicant: NGK Insulators, Ltd.
    Inventors: Iwao Ohwada, Takayoshi Akao, Tetsuyuki Kameji, Hirokazu Nakamura
  • Patent number: 7006061
    Abstract: A display device has first row select lines for selecting rows of picture elements, picture element signal lines for supplying picture element signals to picture elements which are selected, a drive unit having drive circuits arrayed at respective picture elements each for driving the corresponding actuator in response to a picture element signal, and a selector unit for selecting the actuators corresponding to selected picture elements. Each of the drive circuits has a drives potential generating circuit for applying a drive potential based on a signal from a picture element signal line to upper electrodes of actuators. The selector unit has selector circuits for applying a select potential to lower electrodes of the actuators corresponding to selected picture elements.
    Type: Grant
    Filed: March 24, 2003
    Date of Patent: February 28, 2006
    Assignee: NGK Insulators, Ltd.
    Inventors: Yukihisa Takeuchi, Tsutomu Nanataki, Iwao Ohwada, Yasuharu Kuno, Takayoshi Akao
  • Patent number: RE40489
    Abstract: One selection period S and display cycles Td of a number corresponding to a maximum gradation level are allotted in one field, and the display cycle Td is composed of an unselection period U and a reset period R to perform the following control. A row electrode-driving circuit is used to output a selection pulse Ps during the selection period S, output an unselection signal Su during the unselection period U in the display cycle Td, and output a reset pulse Pr during the reset period R. A column electrode-driving circuit is used to output an ON signal during a light emission maintenance period, and output an OFF signal at least at an end timing of the light emission maintenance period, of the period other than the light emission maintenance period. Accordingly, it is possible to effectively reduce the electric power consumption, and it is possible to achieve the high brightness.
    Type: Grant
    Filed: November 17, 2004
    Date of Patent: September 9, 2008
    Assignee: NGK Insulators, Ltd.
    Inventors: Yukihisa Takeuchi, Tsutomu Nanataki, Iwao Ohwada, Takayoshi Akao