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).
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Publication number: 20080042600Abstract: 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: ApplicationFiled: November 29, 2005Publication date: February 21, 2008Inventors: Toru Teraoka, Akihiro Takagi
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Publication number: 20080036728Abstract: A method and system to reduce power consumption of a display includes using a matrix of light sources to illuminate pixels in display segments. The light sources may be light emitting diodes (LED). An LED may be associated with a display segment. The intensity level of an LED may be individually controlled.Type: ApplicationFiled: August 10, 2006Publication date: February 14, 2008Inventors: Akihiro Takagi, David Williams, Achintya K. Bhowmik, Jim Kardach
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Publication number: 20070296325Abstract: 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: ApplicationFiled: February 14, 2007Publication date: December 27, 2007Inventors: Takashi Sasaki, Akira Otsuka, Akihiro Takagi
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Patent number: 7307603Abstract: A first and a second signal line respectively supplying a first potential and a second potential to one end of a capacitive load, a waveform output circuit whose input terminal is connected to a supply line supplying a third potential, whose output terminal is connected to the first or the second signal line, and whose control terminal is connected to a waveform generating circuit, and a reactive current preventing switch connected between the control terminal and the output terminal or the input terminal of the waveform output circuit are provided. During a period when a reactive current is prevented from flowing, the reactive current preventing switch is bought into conduction to make a potential difference between the control terminal and the output terminal of the waveform output circuit smaller so that the waveform output circuit cannot be operated, which prevents the reactive current from flowing, leading to an improvement in the reliability of a driving circuit.Type: GrantFiled: October 4, 2004Date of Patent: December 11, 2007Assignee: Fujitsu Hitachi Plasma Display LimitedInventors: Makoto Onozawa, Tomokatsu Kishi, Tetsuya Sakamoto, Akihiro Takagi
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Publication number: 20070236417Abstract: In a PDP apparatus provided with a PDP having (X, Y, A) and various drivers, two adjacent Ys in a plurality of Ys are commonly connected by a wiring so as to form one set unit, in the vicinity of a connection portion of the PDP and the drivers. A two-stage reset and address operation control using a reset operation including an address disable operation is used for a control unit including a plurality of display lines (L) of the set units. In a plurality of Ls as objects of drive display, the reset and address operation of first Ls (Lo) corresponding to Ys on one side of set units and that of second Ls (Le) corresponding to Ys on the other side thereof are performed separately in former and latter periods, and then, sustain operations of the first and second Ls on both sides are performed simultaneously.Type: ApplicationFiled: February 7, 2007Publication date: October 11, 2007Inventors: Akihiro Takagi, Tetsuya Sakamoto, Takashi Shiizaki
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Patent number: 7145526Abstract: 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: GrantFiled: May 19, 2003Date of Patent: December 5, 2006Assignee: Fujitsu Hitachi Plasma Display LimitedInventors: Akihiro Takagi, Takashi Shiizaki, Takayuki Shimizu, Noriaki Setoguchi, Hitoshi Hirakawa, Tomokatsu Kishi
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Publication number: 20060227074Abstract: In a plasma display device including: a plasma display panel having scan electrodes, sustain electrodes, and address electrodes; scan electrode driving circuits; a sustain electrode driving circuit; and an address electrode driving circuit, each sub-field has a reset period, an address period in which scan pulses are sequentially applied to the scan electrodes, and address pulses are applied to the data electrodes in synchronization with the application to select cells to be turned on, and a sustain period in which the selected cells are turned on. An identical line detecting circuit for detecting display identical lines on which the turned-on cells on one line are identical in each sub-field is provided, and the scan electrode driving circuit simultaneously applies the scan pulses to a plurality of scan electrodes corresponding to the display identical lines in the address period.Type: ApplicationFiled: March 24, 2006Publication date: October 12, 2006Inventors: Takashi Sasaki, Yoshikazu Kanazawa, Akihiro Takagi
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Publication number: 20060220994Abstract: A plasma display device capable of stably generating a discharge between an address electrode and a scan electrode without being influence by temperature in an address period is provided. The plasma display device having a temperature detecting part that detects temperature, a scan electrode to which a scan pulse for selection is applied in the address period, an address electrode to which an address pulse is applied corresponding to the scan pulse to select emission or non-emission of a display cell, and a scan electrode drive circuit which supplies a voltage to the scan electrode in accordance with the detected temperature is provided. The scan electrode dive circuit changes a voltage of the scan electrode at a time of not applying the scan pulse in the address period in accordance with the detected temperature without changing an amplitude of the scan pulse.Type: ApplicationFiled: March 27, 2006Publication date: October 5, 2006Applicant: Fujitsu Hitachi Plasma Display LimitedInventors: Akihiro TAKAGI, Takashi Sasaki, Akira Otsuka
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Publication number: 20060187149Abstract: 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: ApplicationFiled: April 25, 2006Publication date: August 24, 2006Applicant: FUJITSU HITACHI PLASMA DISPLAY LIMITEDInventors: Akihiro Takagi, Takashi Shiizaki, Takayuki Shimizu, Noriaki Setoguchi, Hitoshi Hirakawa, Tomokatsu Kishi
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Publication number: 20060170621Abstract: A plasma display device includes a first electrode from which sustain discharge occurs; a second electrode from which sustain discharge occur to the first electrode, a distance from the second electrode to the first electrode continuously varying in one discharge space; and a driving circuit which generates a sustain discharge pulse that rises in two stages, with an application time of a second-stage voltage being longer than an application time of a first-stage voltage, to apply the sustain discharge pulse between the first and second electrodes, thereby causing the sustain discharge.Type: ApplicationFiled: January 13, 2006Publication date: August 3, 2006Applicant: FUJITSU HITACHI PLASMA DISPLAY LIMITEDInventors: Akihiro Takagi, Takashi Sasaki, Akira Otsuka
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Publication number: 20060158391Abstract: 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: ApplicationFiled: December 28, 2005Publication date: July 20, 2006Inventors: Yuji Sano, Akihiro Takagi, Tomokatsu Kishi, Toyoshi Kawada, Yoshinori Okada
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Patent number: 7078865Abstract: 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: GrantFiled: August 21, 2001Date of Patent: July 18, 2006Assignee: Fujitsu Hitachi Plasma Display LimitedInventors: Yuji Sano, Akihiro Takagi, Tomokatsu Kishi, Toyoshi Kawada, Hirokazu Inoue
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Publication number: 20060152167Abstract: 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: ApplicationFiled: December 14, 2005Publication date: July 13, 2006Applicant: FUJITSU HITACHI PLASMA DISPLAY LIMITEDInventors: Akihiro Takagi, Takashi Sasaki, Akira Otsuka
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Publication number: 20060125411Abstract: 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: ApplicationFiled: February 10, 2006Publication date: June 15, 2006Applicant: FUJITSU HITACHI PLASMA DISPLAY LTD.Inventors: Yuji Sano, Akihiro Takagi, Tomokatsu Kishi, Toyoshi Kawada, Hirokazu Inoue
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Publication number: 20060119546Abstract: 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: ApplicationFiled: November 9, 2005Publication date: June 8, 2006Inventors: Akira Otsuka, Takashi Sasaki, Akihiro Takagi
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Publication number: 20060012545Abstract: There is provided a drive circuit of a display device using a capacitive load which includes a clamp circuit connected to a power source potential and clamping a potential of the capacitive load to the power source potential such that an electric power is supplied to the capacitive load in a temporally dispersed manner. For example, the clamp circuit includes a plurality of switches parallelly connected between the capacitive load and the power source potential, the plurality of switches being turned on at different times.Type: ApplicationFiled: July 15, 2005Publication date: January 19, 2006Applicant: FUJITSU HITACHI PLASMA DISPLAY LIMITEDInventors: Tomokatsu Kishi, Tetsuya Sakamoto, Akihiro Takagi, Satoru Nishimura, Yoshikazu Kanazawa, Takayuki Kobayashi, Takashi Sasaki, Yasunobu Hashimoto
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Publication number: 20050218822Abstract: 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: ApplicationFiled: May 31, 2005Publication date: October 6, 2005Applicant: FUJITSU HITACHI PLASMA DISPLAY LIMITEDInventors: Yuji Sano, Akihiro Takagi, Tomokatsu Kishi, Toyoshi Kawada, Hirokazu Inoue
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Publication number: 20050184928Abstract: 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: ApplicationFiled: November 10, 2004Publication date: August 25, 2005Applicant: Fujitsu Hitachi Plasma Display LimitedInventors: Tomoya Matsui, Shigetoshi Tomio, Akihiro Takagi, Tetsuya Sakamoto, Tomokatsu Kishi
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Patent number: 6925228Abstract: A practical optical waveguide circuit is provided which includes many intersections but is low loss. The width of a waveguide core is w1 at input and output terminal sections and w2 at an intersecting section, where w2>w1. The core width of the intersecting section is made different from that of the input and output terminal sections, or the core height of the intersecting section is made different from that of the input and output terminal sections. The core width is smoothly varied between the intersecting section and the input and output terminal sections by a tapered section. When the number of the waveguides intersecting with the intersecting section is 100, the intersection loss is 5.8 dB for the conventional device where w2=w1=5 ?m, but is 1.8 dB when w2=12 ?m, thereby being able to reduce the intersection loss sharply.Type: GrantFiled: December 16, 2002Date of Patent: August 2, 2005Assignee: Nippon Telegraph and TelephoneInventors: Shin Kamei, Motohaya Ishii, Akihiro Takagi, Takeshi Kitagawa
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Publication number: 20050140309Abstract: A first and a second signal line respectively supplying a first potential and a second potential to one end of a capacitive load, a waveform output circuit whose input terminal is connected to a supply line supplying a third potential, whose output terminal is connected to the first or the second signal line, and whose control terminal is connected to a waveform generating circuit, and a reactive current preventing switch connected between the control terminal and the output terminal or the input terminal of the waveform output circuit are provided. During a period when a reactive current is prevented from flowing, the reactive current preventing switch is bought into conduction to make a potential difference between the control terminal and the output terminal of the waveform output circuit smaller so that the waveform output circuit cannot be operated, which prevents the reactive current from flowing, leading to an improvement in the reliability of a driving circuit.Type: ApplicationFiled: October 4, 2004Publication date: June 30, 2005Applicant: FUJITSU HITACHI PLASMA DISPLAY LIMITEDInventors: Makoto Onozawa, Tomokatsu Kishi, Tetsuya Sakamoto, Akihiro Takagi