Patents by Inventor Akihiro Takagi

Akihiro Takagi 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).

  • Publication number: 20100220115
    Abstract: A plasma display device has a plasma display panel (PDP) and a driver unit driving the PDP. One field for displaying one screen of the PDP is made up of a plurality of subfields having a reset period and an address period. At least one of the plurality of subfields is a subfield for low luminance with number of times of sustain discharge being set to 0 (zero) and a voltage between a scan electrode and a sustain electrode during the address period being set smaller than a firing voltage between the scan electrode and the sustain electrode. The driver unit applies between the scan electrodes and the sustain electrodes a voltage smaller than the firing voltage between the scan electrodes and the sustain electrodes in a reset period of a subfield subsequent to the subfield for low luminance. As a result, luminance when reproducing black can be lowered.
    Type: Application
    Filed: December 17, 2007
    Publication date: September 2, 2010
    Inventors: Tetsuya Sakamoto, Takashi Sasaki, Akihiro Takagi
  • Patent number: 7768188
    Abstract: An optical filter is provided on the output side of light from plural kinds of cells that output light with colors different from one another. In the optical filter, the penetrable rate of at least a portion of the wavelength band of light output from the cell with the color having highest luminescent intensity is set lower than that of the wavelength band of other kinds of cells. Consequently, the reflectance rate of outer light incident to a display can be reduced. Particularly, in a room environment using artificial lighting, the reflectance rate of outer light can be reduced in the wavelength band of light with relatively high luminescent intensity. Resultingly, bright room contrast can be improved by suppressing the reflection of outer light. Since the penetrable rate of the color with the highest luminescent intensity is reduced, reduction in brightness of the display can be kept to a minimum.
    Type: Grant
    Filed: February 14, 2007
    Date of Patent: August 3, 2010
    Assignee: Fujitsu Hitachi Plasma Display Limited
    Inventors: Takashi Sasaki, Akira Otsuka, Akihiro Takagi
  • Patent number: 7737641
    Abstract: A capacitive-load driving circuit has a configuration in which a driving power supply source is connected to an output terminal via a driving device. The capacitive-load driving circuit has a power distributing circuit inserted between the driving power supply source and the driving device. Therefore, temperature rise (power consumption) in the capacitive-load driving circuit can be distributed.
    Type: Grant
    Filed: February 10, 2006
    Date of Patent: June 15, 2010
    Assignee: Fujitsu Hitachi Plasma Display Limited
    Inventors: Yuji Sano, Akihiro Takagi, Tomokatsu Kishi, Toyoshi Kawada, Hirokazu Inoue
  • Publication number: 20100141625
    Abstract: In a driving method of a plasma display panel having a plurality of first electrodes provided so as to correspond to phosphors of a plurality of emitted light colors and having a plurality of second electrodes disposed so as to intersect with the first electrodes, the first electrodes for each of the emitted light colors that are provided so as to correspond to at least one of the phosphors of the emitted light colors among the first electrodes are brought into an electrically open state at the part of driving timings in a driving period. By doing so, gas discharge currents that flow through the first electrodes for each of the emitted light colors can be suppressed.
    Type: Application
    Filed: February 17, 2010
    Publication date: June 10, 2010
    Inventors: Yuji SANO, Akihiro Takagi, Tomokatsu Kishi, Toyoshi Kawada, Yoshinori Okada
  • Patent number: 7663574
    Abstract: A problem is to be solved in that there is to be provided a display device and a display method allowing two or more sorts of sustaining pulses to be employed by switching over the pulses depending on the state of display in such a manner as to achieve characteristics including high light emission efficiency/decrease in streaking and high luminance and the like. The display device is provided wherein one frame image contains a plurality of sub-frames, including: a detection section detecting a state of display: a sustaining pulse output section to select and output one out of two or more sorts of sustaining pulses for a display for each sub-frame depending on the state of display.
    Type: Grant
    Filed: November 9, 2005
    Date of Patent: February 16, 2010
    Assignee: Fujitsu Hitachi Plasma Display Limited
    Inventors: Akira Otsuka, Takashi Sasaki, Akihiro Takagi
  • Publication number: 20090327777
    Abstract: Some embodiments describe techniques that relate to power efficient, high frequency displays with motion blur mitigation. In one embodiment, the refresh rate of a display device may be dynamically modified, e.g., to reduce power consumption and/or reduce motion blur. Other embodiments are also described.
    Type: Application
    Filed: June 30, 2008
    Publication date: December 31, 2009
    Inventors: Maximino Vasquez, Akihiro Takagi, Yanli Zhang, Achintya K. Bhowmik
  • Publication number: 20090322795
    Abstract: A system, apparatus and method to reduce power consumption for displays is described. The method may include receiving image data comprising a plurality of color components, generating a histogram for each of the plurality of color components, and adjusting each of a plurality of light sources based on the histograms. The plurality of light sources may correspond to the plurality of color components. Other embodiments are described and claimed.
    Type: Application
    Filed: June 30, 2008
    Publication date: December 31, 2009
    Inventors: Maximino Vasquez, Achintya Bhowmik, Yanli Zhang, Akihiro Takagi
  • Patent number: 7639213
    Abstract: A driving circuit of a plasma display panel is provided in which a display cell including a first electrode and a second electrode is selected to light up, for applying a first voltage Vs1 to the first electrode and a second voltage Vs2 to the second electrode adjacent to the first electrode to cause a sustain discharge between the first and second electrodes. The driving circuit generates a sustain discharge voltage such that, during the sustain discharge between the first and second electrodes, an applied voltage Vc to a third electrode adjacent to the first electrode opposite to the second electrode falls within a range Vs2?Vc<Vs1, and, in this case, when a display cell including the third electrode is selected to light up, the polarity of a wall charge formed on the third electrode becomes positive.
    Type: Grant
    Filed: April 25, 2006
    Date of Patent: December 29, 2009
    Assignee: Fujitsu Hitachi Plasma Display Limited
    Inventors: Akihiro Takagi, Takashi Shiizaki, Takayuki Shimizu, Noriaki Setoguchi, Hitoshi Hirakawa, Tomokatsu Kishi
  • Patent number: 7633497
    Abstract: An air purifier includes a main body defining an air passage therein to allow sucked air to pass therethrough prior to being discharged, and a first filter installed in the main body to be switched between a closed state and an open state. The first filter removes contaminants from the sucked air in the closed state, and allows the sucked air to pass through the air passage in the open state. The air purifier may include a main body to suck and discharge air, with a bypass passage formed in the main body so that the bypass passage is opened or closed by a door, and a first filter installed in the main body. The sucked air passes through the first filter prior to being discharged when the door is closed, and passes through the bypass passage prior to being discharged when the door is opened.
    Type: Grant
    Filed: November 10, 2004
    Date of Patent: December 15, 2009
    Assignee: Fujitsu Hitachi Plasma Display Limited
    Inventors: Tomoya Matsui, Shigetoshi Tomio, Akihiro Takagi, Tetsuya Sakamoto, Tomokatsu Kishi
  • Publication number: 20090231235
    Abstract: In a plasma display module, the cost and size of a power supply circuit are reduced.
    Type: Application
    Filed: June 20, 2005
    Publication date: September 17, 2009
    Inventors: Akira Otsuka, Takashi Sasaki, Akihiro Takagi
  • Publication number: 20090231309
    Abstract: In a long-gap discharge using a trigger discharge in a display cell of a PDP having three electrodes (X, Y, A), a technology capable of stably generating the trigger discharge with low power consumption by using a float electrode is provided. In a dielectric layer of the PDP, a long gap is formed between first and second display electrodes, first and second float electrodes which are capacitive-coupled to the first and second display electrodes are formed, and a short gap is formed between the first and second float electrodes. A sustain pulse is applied to the first and second display electrodes, thereby generating a small trigger discharge in the short gap. Subsequently to this discharge, a main discharge at the long gap is generated. Electrodes and capacitances are structured so that the main discharge has an intensity equal to or smaller than one-fifth of an intensity of the trigger discharge.
    Type: Application
    Filed: December 2, 2005
    Publication date: September 17, 2009
    Inventors: Akira Otsuka, Takashi Sasaki, Akihiro Takagi
  • Patent number: 7576712
    Abstract: The present invention provides a plasma display device including: a plurality of scan electrodes sequentially scanned to be impressed with a scan pulse; an address electrode that is impressed with an address pulse corresponding to the scan pulse, for selection of a display pixel; a scan driving circuit generating the scan pulse; and an address driving circuit generating the address pulse. The address pulse rises in n stages (n is an integer equal to or larger than 2), and a period in a period during which the address pulse rises from a lowest voltage to a highest voltage overlaps a scan pulse immediately prior to the scan pulse corresponding to the address pulse.
    Type: Grant
    Filed: December 14, 2005
    Date of Patent: August 18, 2009
    Assignee: Fujitsu Hitachi Plasma Display Limited
    Inventors: Akihiro Takagi, Takashi Sasaki, Akira Otsuka
  • Publication number: 20090184945
    Abstract: An erroneous address discharge in the latter address when the so-called interlace scan is performed is prevented. A period for adjusting the charge of non-lighting cells is provided after an address period in a plasma display of the address-display-period separation method. The discharge in this period is a discharge between an X electrode or an address electrode and a scan electrode, and the discharge has the same polarity as the voltages applied in the address operation, but the relative voltage is rather low, and the discharge is weaker than the address discharge of lighting cells.
    Type: Application
    Filed: July 31, 2008
    Publication date: July 23, 2009
    Inventors: Takashi SASAKI, Akihiro Takagi
  • Publication number: 20090167752
    Abstract: A technique capable of enhancing performance of a reset operation by a reset waveform using a step-wise rectangular wave and obtaining stable display characteristics in a subfield drive control of a PDP device is provided. In the PDP driving method, in the drive control of the subfield, a reset waveform including a rectangular wave raised in a plurality of steps in a step-wise manner is used in the reset operation, and the application timing of a partial waveform having one or more steps previous to a second step in the rectangular wave is shifted according to the number of sustains previous to the reset operation.
    Type: Application
    Filed: August 9, 2006
    Publication date: July 2, 2009
    Inventors: Akihiro Takagi, Tetsuya Sakamoto
  • Publication number: 20090079726
    Abstract: A plasma display driving method and apparatus that can reduce the occurrences of dropout, on a displayed image, caused by misaddress when the environment temperature becomes low. In the inventive plasma display, the environment temperature is determined, and during a charge adjustment interval, the ultimate voltage, which the drive waveform of a scan electrode voltage reaches at the end after continuously varying in the negative direction, is changed in accordance with the determined environment temperature in such a manner that if the environment temperature becomes lower, the ultimate voltage is directed in the positive direction.
    Type: Application
    Filed: June 20, 2005
    Publication date: March 26, 2009
    Inventors: Akihiro Takagi, Takashi Sasaki, Akira Otsuka
  • Publication number: 20090066609
    Abstract: A method and an apparatus for driving a plasma display in which supply of a driving waveform to the non-lighting display line of a plasma display screen is stopped while preventing level difference in luminance or instability of operational margin incident to stoppage of driving waveform supply. In the inventive plasma display, a sustain waveform is created and supplied to each display line of the plasma display, and supply of the sustain waveform is stopped for such a display line as no cell is lighted at all in a unit of sub-field thus quickening the clamp period of sustain waveform by using an inductance having an increased L value and shortening the sustain cycle.
    Type: Application
    Filed: July 6, 2005
    Publication date: March 12, 2009
    Inventors: Akihiro Takagi, Takashi Sasaki, Akira Otsuka, Tetsuya Sakamoto
  • Publication number: 20090027308
    Abstract: Provided is a method for driving plasma display panel capable of changing the quantity of emission in an erasure discharge. The method drives a plasma display panel including a scan electrode drive circuit (3) for driving scan electrodes (112), a sustain electrode drive circuit (2) for driving sustain electrodes (111), an address electrode drive circuit (4) for driving address electrodes (121), and a control circuit (5) for controlling the actions of the individual drive circuits. The individual drive circuits are driven for a reset period, in which one field is divided for actions into a plurality of sub-fields for adjusting the electric charges in cells, for an address period, in which cells to be issued are designated, for a sustain period, in which discharges are repeated with the scan electrodes and the sustain electrodes to cause the emissions of the cells, and for an erase period, in which the quantity of wall charges formed in the cell having emitted finally of the sustain period is reduced.
    Type: Application
    Filed: August 4, 2005
    Publication date: January 29, 2009
    Inventors: Takashi Sasaki, Akira Otsuka, Akihiro Takagi
  • Publication number: 20080238908
    Abstract: In this PDP apparatus, in a sustain driving circuit device for supplying sustain discharge pulses, an energy recovery circuit has a coil, switches, and diodes, and a Vs clamp circuit has switches. In the energy recovery circuit, the switches are connected to a panel capacitor, and the coil is connected to a power source line with an intermediate potential of Vs, and a clamp diode and a power source connected thereto are connected to a node between the coil and the switch. As a control timing, at a timing of less than ?/2 of an LC resonance current cycle, the switch of the energy recovery circuit is turned OFF and then the switch of the Vs clamp circuit is turned ON, thereby performing the Vs clamp.
    Type: Application
    Filed: August 31, 2007
    Publication date: October 2, 2008
    Inventors: Tetsuya Sakamoto, Akira Otsuka, Akihiro Takagi, Shigetoshi Tomio
  • Publication number: 20080136748
    Abstract: A novel PDP device capable of reducing the peak current of a sustain discharge without the need to modify circuits has been disclosed.
    Type: Application
    Filed: August 17, 2005
    Publication date: June 12, 2008
    Applicant: FUJITSU HITACHI PLASAMA DISPLAY LIMITED
    Inventors: Akira Otsuka, Takashi Sasaki, Akihiro Takagi
  • Publication number: 20080042600
    Abstract: A display apparatus having a capacitive load (Cij), clamp circuits (103, 104) for clamping the potential of the capacitive load to high and low levels, power recovering circuits (103, 104) including coils for recovering power from the capacitive load and supplying the recovered power to the capacitive load, a display load rate determining part (111) for determining a display load rate, and a control part (112) is provided. When the determined display load rate is smaller than a first threshold value, the control part does not use the power recovering circuits but uses the clamp circuits to control the potential of the capacitive load. When the determined display load rate is larger than the first threshold value, the control part uses the power recovering circuits and clamp circuits to control the potential of the capacitive load.
    Type: Application
    Filed: November 29, 2005
    Publication date: February 21, 2008
    Inventors: Toru Teraoka, Akihiro Takagi