Patents by Inventor Akihisa Kawamura
Akihisa Kawamura 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: 20020026255Abstract: This invention relates to a signal transmission apparatus and a signal transmission method both for transmitting a plurality of pieces of encoded audio information having a plurality of sampling frequencies of F or 1/N×F, which are encoded by the same encoding method, via a digital interface to a signal reception apparatus.Type: ApplicationFiled: August 21, 2001Publication date: February 28, 2002Inventors: Masahiro Sueyoshi, Takeshi Fujita, Kazutaka Abe, Kosuke Nishio, Takashi Katayama, Masaharu Matsumoto, Akihisa Kawamura
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Publication number: 20020003765Abstract: A decoding circuit inputs a data stream D3 which has been multiplexed at different sampling frequencies, and separates it into two audio data D1 and D2 at different sampling frequencies, which it supplies to buffers. The output of the buffer is inputted to an up-sampling circuit, which, along with performing up-sampling at a frequency which corresponds to a processing unit of data of which the time delay amount is predetermined, also suppresses aliasing distortion. On the other hand, the output of the buffer is inputted to a delay buffer, which delays it by a time delay amount the same as that due to the up-sampling circuit. By doing this, the reproducing phases of the two streams of audio signals are coincided.Type: ApplicationFiled: July 9, 2001Publication date: January 10, 2002Inventors: Masaharu Matsumoto, Takashi Katayama, Masahiro Sueyoshi, Kousuke Nishio, Takeshi Fujita, Akihisa Kawamura, Kazutaka Abe
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Publication number: 20010050959Abstract: An encoder comprises an input device for sampling an input signal at predetermined time intervals to obtain sampled data on a temporal axis, a conversion device for converting the sampled data on the temporal axis to spectral data on a frequency axis, a quantization device for quantizing the spectral data on the frequency axis, and an output device for outputting a resultant value of quantization as an encoded bit stream. The quantization device comprises an expected-value-of-quantization adjustment portion for determining an expected value of quantization for a specific sub-band on the frequency axis, and a quantization portion for determining a quantization coefficient for the specific sub-band, and quantizing each of a plurality of spectral data contained in the specific sub-band using the quantization coefficient for the specific sub-band.Type: ApplicationFiled: March 30, 2001Publication date: December 13, 2001Inventors: Kosuke Nishio, Takashi Katayama, Masaharu Matsumoto, Akihisa Kawamura, Takeshi Fujita, Masahiro Sueyoshi, Kazutaka Abe
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Publication number: 20010031007Abstract: According to the data amount and the nature of a video stream and an audio stream included in a program stream which is to be decoded, an audio and video processing apparatus performs processing while allocating higher priority to one or the other of the video and audio streams. Without any increase in circuit complexity or clock speed, this apparatus can reproduce streams in at least two formats, in which the ratios of the amounts of encoded signal data and of the amounts of calculation required for decoding for the video and the audio are very different.Type: ApplicationFiled: March 1, 2001Publication date: October 18, 2001Inventors: Takeshi Fujita, Takashi Katayama, Masahiro Sueyoshi, Kousuke Nishio, Masaharu Matsumoto, Akihisa Kawamura, Kazutaka Abe, Ryoji Yamaguchi, Makoto Meiarashi, Ken Monda
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Patent number: 6304890Abstract: A device of the present invention is an exponential calculation device for calculating x{circumflex over ( )}(a/b) (where a and b are each an integer constant) for a given input value of x. The device includes: an input control section for outputting a value of x′, wherein x′=x when x≦A (where A is a threshold value within a variable range of x) and x′=x/2{circumflex over ( )}b when x>A; a core section for outputting a value of z′=x′{circumflex over ( )}(a/b); and an output control section for outputting a value of z, wherein z=z′ when x≦A and z=z′*2{circumflex over ( )}a when x>A.Type: GrantFiled: February 3, 1999Date of Patent: October 16, 2001Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Shuji Miyasaka, Takeshi Fujita, Masahiro Sueyoshi, Akihisa Kawamura, Masaharu Matsumoto, Takashi Katayama, Kazutaka Abe, Kosuke Nishio
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Patent number: 6297754Abstract: A decoding device for decoding a data stream includes a decoding table including a first region and a second region; a first decoder; and a second decoder. The first region defines a relationship between first data having a predetermined number of bits and a result of decoding a portion of the first data having bits smaller than or equal to the predetermined number. The second region defines a relationship between concatenated data obtained by concatenating the first data with second data having additional bits and a result of decoding the concatenated data. The first decoder reads the first data from the data stream; decodes the portion of the first data based on the first region; determines whether the decoding of the portion of the first data is completed or not; and when the decoding of the portion of the first data is completed, outputs a result of the decoding of the portion of the first data.Type: GrantFiled: March 30, 2000Date of Patent: October 2, 2001Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Shuji Miyasaka, Takeshi Fujita, Masahiro Sueyoshi, Akihisa Kawamura, Masaharu Matsumoto, Takashi Katayama, Kazutaka Abe, Kousuke Nishio
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Patent number: 6295319Abstract: A decoding device for decoding a bit stream defined by MPEG2 Audio Multichannel is provided. The bit stream including an MPEG1 compatible area and an MPEG2 multichannel extended area, the MPEG1 compatible area including MPEG1 side information. The decoding device includes: MPEG1 decoding means for decoding the MPEG1 compatible area; MC decoding means for decoding the MPEG2 multichannel extended area; and MC header detection means for executing a first processing including locating a position of a header of the MPEG2 multichannel extended area based on the MPEG1 side information and shifting a read position of the bit stream to the position of the header.Type: GrantFiled: March 29, 1999Date of Patent: September 25, 2001Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Masahiro Sueyoshi, Masaharu Matsumoto, Shuji Miyasaka, Takeshi Fujita, Takashi Katayama, Kazutaka Abe, Kosuke Nishio, Akihisa Kawamura, Tsukuru Ishito, Tsuyoshi Nakamura, Eiji Otomura
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Patent number: 6262965Abstract: In an optical disk, data are recorded by using a hierarchical file structure in which a frame is composed of digitized data, a packet is composed of at least one frame, and a pack is composed of at least one packet. In this structure, the pack is composed of an integral number of packets, each packet being completed, and each of the packets is composed of an integral number of frames, each frame being completed. Therefore, there is no possibility that one frame is assigned over two or more different packets and one packet is assigned over two or more different packs. Since an integral number of frames are assigned in each packet, when a packet header is detected, reproduction of data can be carried out from the beginning of each packet.Type: GrantFiled: October 14, 1998Date of Patent: July 17, 2001Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Masatoshi Shimbo, Ryoji Suzuki, Yoshihiro Mori, Akihisa Kawamura
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Patent number: 6233562Abstract: An audio decoding device for decoding coded audio information with multiple channels includes a coded information memory section for storing the coded audio information; an information transmission section for reading the coded audio information stored at an arbitrary position in the coded information memory section; and an audio decoding section for decoding the coded audio information read by the information transmission section and outputting the resultant audio information in accordance with a time axis.Type: GrantFiled: December 8, 1997Date of Patent: May 15, 2001Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Masahiro Sueyoshi, Shuji Miyasaka, Tukuru Ishito, Takeshi Fujita, Takashi Katayama, Masaharu Matsumoto, Tuyoshi Nakamura, Eiji Otomura, Akihisa Kawamura
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Patent number: 6118821Abstract: A compressed code decoding device of the present invention includes: a decoding section for receiving a plurality of groups of blocks of compressed codes and decoding each of the blocks of compressed codes; a buffer section for storing decoded signals decoded by the decoding section; a reproduction time acquisition section for acquiring a reproduction time at which to reproduce a predetermined one of the blocks; an output section for externally outputting the decoded signals stored in the buffer section; a detection section for detecting that the predetermined block of compressed codes has been decoded and output via the output section; an addition section for, at a time when the detection section detects that the predetermined block has been output, adding a time required for reproducing the predetermined block to the reproduction time acquired by the reproduction time acquisition section so as to produce a synchronization time; a synchronization section for comparing the synchronization time produced by theType: GrantFiled: May 15, 1998Date of Patent: September 12, 2000Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Masaharu Matsumoto, Takashi Katayama, Masahiro Sueyoshi, Shuji Miyasaka, Takeshi Fujita, Akihisa Kawamura, Tsukuru Ishito, Eiji Otomura, Tsuyoshi Nakamura
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Patent number: 5813874Abstract: A relay apparatus between relative rotary members comprises a first rotator (a rotator) 11 having an inner cylindrical portion, a second rotator (a fixed body) having an outer cylindrical portion for surrounding the inner cylindrical portion at a predetermined interval, and relatively rotating to the inner cylindrical portion, a flexible flat cable (a cable) coiled along an inside of a circular space K between the inner cylindrical portion and the outer cylindrical portion, an upper cover having an aperture at a center portion, installed in the outer cylindrical portion in order to cover an upper side of the circular space, and an outer leading cover installed on the upper cover for rotating flexibly, and coupled to the first rotator through the aperture for leading the flexible flat cable outward. The outer leading cover has a circular rib A connected to the upper cover on its outer circumferential portion, whose diameter of an outer circumference is shorter than that of the upper cover.Type: GrantFiled: November 13, 1996Date of Patent: September 29, 1998Assignee: Yazaki CorporationInventors: Hidehiro Ichikawa, Hiraku Tanaka, Akihisa Kawamura
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Patent number: 5796845Abstract: The apparatus of the invention calculates filter coefficients for controlling sound field and sound image, based on a plurality of first impulse response signals and a pair of second impulse response signals. The plurality of first impulse response signals indicate impulse responses from loudspeakers reproducing audio signals to both ears of a listener. The pair of second impulse response signals indicate impulse responses from a reference loudspeaker at a position at which a sound image is localized to both ears of the listener.Type: GrantFiled: June 26, 1997Date of Patent: August 18, 1998Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Mitsuhiko Serikawa, Ryou Tagami, Akihisa Kawamura, Masaharu Matsumoto, Mikio Oda, Hiroko Numazu
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Patent number: 5742688Abstract: A sound field controller of the invention reproduces a sound field which provides a distance perspective depending on a position of a sound image for a listener. The sound field controller includes: an A/D converter; a signal processing section for processing the digital signal using predetermined parameters, and generating a sound signal; an input device for inputting conditions which include a position of a sound image to be localized and a distance from a listener; a parameter controller for setting the parameters in the signal processing section so that the sound signal has characteristics in accordance with the input conditions; a D/A converter; and a reproducing unit for amplifying and reproducing the signal output from the D/A converter.Type: GrantFiled: February 3, 1995Date of Patent: April 21, 1998Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Michiko Ogawa, Akihisa Kawamura, Masaharu Matsumoto, Toshihiko Date, Tadashi Tamura, Yasutoshi Nakama
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Patent number: 5700153Abstract: A relay device includes a first rotor having an inner cylinder, a second rotor having an outer cylinder and a cover attached to the inner cylinder. A flexible flat cable is accommodated in an annular space defined between the inner cylinder and the outer cylinder. The inner cylinder is provided with a shroud part for retaining the end portion of the flexible flat cable therein while the cover is provided with a press part. The press part is arranged so that, when the cover is attached to the inner cylinder, the press part is brought into contact with the shroud part from the outside. Therefore, the press part urges the inner end portion of the cable against the inner cylinder, whereby the inner end portion of the cable can be fixed on the inner cylinder securely.Type: GrantFiled: January 3, 1996Date of Patent: December 23, 1997Assignee: Yazki CorporationInventors: Akihisa Kawamura, Satoshi Ishikawa, Hiroaki Iizuka
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Patent number: 5684881Abstract: The apparatus of the invention calculates filter coefficients for controlling sound field and sound image, based on a plurality of first impulse response signals and a pair of second impulse response signals. The plurality of first impulse response signals indicate impulse responses from loudspeakers reproducing audio signals to both ears of a listener. The pair of second impulse response signals indicate impulse responses from a reference loudspeaker at a position at which a sound image is localized to both ears of the listener.Type: GrantFiled: May 23, 1994Date of Patent: November 4, 1997Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Mitsuhiko Serikawa, Ryou Tagami, Akihisa Kawamura, Masaharu Matsumoto, Mikio Oda, Hiroko Numazu
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Patent number: 5677987Abstract: An A/D converter converts an analog signal to a digital signal. A plurality of cascade-connected notch filters include a first notch filter which is connected to the output of the A/D converter. A D/A converter is connected to the output of the last stage notch filter for converting a digital signal to an analog signal. The output of the last stage notch filter is connected to the input of a fast Fourier transform unit for analyzing the frequency. Analysis results of the fast Fourier transform unit are supplied to a detector. A coefficient having the same center frequency as that of a peak frequency outputted from the detector is selected from a coefficient memory and it is transferred to a second coefficient memory. Thus, the frequencies of the notch filters are set to eliminate howling.Type: GrantFiled: July 18, 1994Date of Patent: October 14, 1997Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Nobuyuki Seki, Kazuhiro Onizuka, Akihisa Kawamura
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Patent number: 5617478Abstract: A sound reproduction system for automatically conducting a tone control for an audio signal according to the present invention includes: an input terminal for inputting an audio signal; a judgment circuit for determining a ratio between a stereophonic signal component and a monophonic signal component of the input audio signal and for outputting a judgment signal; a signal processing section for receiving the input audio signal and processing the input audio signal so as to generate an output signal having uniform transmission characteristics irrespective of the listening position; an adder for receiving the input audio signal and the output signal and for adding the input audio signal with the output signal at a certain addition ratio based on the judgment signal so as to generate an added signal; and a loudspeaker for receiving the added signal and for reproducing the added signal in a plurality of positions.Type: GrantFiled: April 11, 1994Date of Patent: April 1, 1997Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Ryou Tagami, Takeshi Norimatsu, Masaharu Matsumoto, Mikio Oda, Mitsuhiko Serikawa, Akihisa Kawamura, Hiroko Numazu
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Patent number: 5572591Abstract: According the present invention, a sound field controller for reproducing a sound field with presence comprising; input terminals for inputting an audio signal having a first and a second channel signals, a signal extracting circuit for receiving and processing the audio signal, and producing an extracted signal of the audio signal, an operation circuit for receiving the extracted signal from the signal extracting circuit, performing the convolution on the extracted signal, and generating a convolution sum signal, a delay circuit for delaying the convolution sum signal by a predetermined time, and producing a delayed signal, an adding circuit for receiving the audio signal and the delayed signal, and adding the audio signal and the delayed signal with a predetermined summation ratio to produce a summed signal, and output terminals for reproducing the summed signal to localize a sound image in a desirable direction.Type: GrantFiled: March 8, 1994Date of Patent: November 5, 1996Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Hiroko Numazu, Masaharu Matsumoto, Akihisa Kawamura, Ryou Tagami, Mikio Oda
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Patent number: 5442712Abstract: A sound signal picked-up by a microphone is processed in a howl suppresser including a digital filter. A frequency analyzer performs frequency analysis of the picked-up sound signal. A howl detector detects a howl contained in the sound signal from a result of frequency analysis by the frequency analyzer. A coefficient calculator calculates coefficients to be input to the digital filter to suppress the howl according to a detection result by the howl detector, and a controller inputs the calculated coefficients to the digital filter. The howl detector judges that a maximum peak power level among power levels of the sound signal in a frequency region analyzed by the frequency analyzer is a howl component when a ratio of the maximum peak power level to a mean power level of the sound signal is larger than a predetermined threshold level, preferably for a predetermined threshold time.Type: GrantFiled: August 31, 1993Date of Patent: August 15, 1995Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Akihisa Kawamura, Masaharu Matsumoto, Mitsuhiko Serikawa, Hiroko Numazu
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Patent number: 5381482Abstract: A sound field controller for generating apparent sound sources by adjusting the amplitude and delay time of a sound signal so that the sound will be perceived by plural listeners as sound coming from a location separated from the specific location of the front speakers, and for additionally controlling the effect of the apparent sound sources by evaluating the attributes of the source sound signal.Type: GrantFiled: February 1, 1993Date of Patent: January 10, 1995Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Masaharu Matsumoto, Mitsuhiko Serikawa, Akihisa Kawamura, Hiroko Numazu, Takeshi Norimatsu, Ryo Tagami, Mikio Oda