Patents by Inventor Hirotsugu Kawada
Hirotsugu Kawada 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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Patent number: 7577251Abstract: A data player for reading contents encrypted by a decoding key from a digital medium, and playing the encrypted contents by using the decoding key which is stored in a key storage unit, comprises: a key obtaining unit for performing mutual authentication with the key storage unit to obtain the decoding key stored in the key storage unit; a key holding unit for holding the decoding key; a playback state obtaining unit for monitoring the playback state of the digital medium; and a contents decoding unit for decoding the encrypted contents by using the decoding key. The decoding key is obtained by the key obtaining unit and stored in the key holding unit, and the encrypted contents read from the digital medium is decoded with the decoding key by the contents decoding unit to play the contents. The decoding key stored in the key holding unit is discarded according to the playback state of the digital medium which is obtained by the playback state obtaining unit.Type: GrantFiled: August 30, 2006Date of Patent: August 18, 2009Assignee: Panasonic CorporationInventors: Hirotsugu Kawada, Noboru Katta, Susumu Ibaraki, Makoto Tatebayashi, Shunji Harada
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Patent number: 7286616Abstract: A data transmission system in which normal transmission can be performed irrespectively of the inserting orientation of a connector is provided. A transmitting device transmits to a receiving device a differential transmission signal including polarity decision data for deciding the polarity of the connector. Based on the polarity decision data included in the differential transmission signal transmitted from the transmitting device, the receiving device decides whether the polarity of the connector has been reversed or not. When it is decided that the polarity has not been reversed, the receiving device reads data from the differential transmission signal. When it is decided that the polarity has been reversed, the polarity of the differential transmission signal is reversed for data reading.Type: GrantFiled: May 30, 2003Date of Patent: October 23, 2007Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Yutaka Takahira, Yuji Mizuguchi, Noboru Katta, Nobuhiko Yasui, Takahisa Sakai, Hirotsugu Kawada, Toshitomo Umei
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Patent number: 7245719Abstract: A recording apparatus records movie content onto a DVD. The movie content is encrypted using a different encryption method depending on whether the DVD is intended for consumer use or industrial use. If the DVD is for consumer use, a VIDEO_TS directory is created on the DVD, and the encrypted movie content is recorded in the VIDEO_TS directory. If the DVD is for industrial use, a VIDEO_TS directory and an EWCPS_TS directory are created on the DVD, and the encrypted movie content and message data are recorded respectively in the EWCPS_TS directory and the VIDEO_TS directory. The message data indicates that the movie content cannot be played back by consumer DVD players.Type: GrantFiled: June 29, 2001Date of Patent: July 17, 2007Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Hirotsugu Kawada, Noboru Katta, Katsuhiko Miwa, Yoshihiro Mori, Masaaki Takata
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Patent number: 7218678Abstract: A digital data transmission apparatus includes a transmitting end (100) that includes: a binary/quadrary conversion unit (110) for converting a data stream; a coding unit (120) for mapping converted data to be coded; a digital filter (130); a D/A conversion unit (140); a low-pass filter (150) for attenuating noises which are caused by folding distortion; a differential driver (160); low-pass filters (170a) and (170b) for eliminating noises from differentially outputted signals; and a common mode choke coil (180) for eliminating common mode noises and outputting a resultant signal to a twisted pair cable (300), and a receiving end (200) that includes: a low-pass filter (210) for eliminating noises from the twisted pair cable; a receiver (220); an A/D conversion unit (230); a digital filter (240); an evaluation unit (250) for evaluating a signal level of a received signal; a decoding unit (260) for decoding the signal level into received data; and a synchronization unit (270) for generating a clock.Type: GrantFiled: October 5, 2001Date of Patent: May 15, 2007Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Noboru Katta, Yuji Mizuguchi, Takahisa Sakai, Hirotsugu Kawada, Toshihiko Kurosaki
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Patent number: 7190728Abstract: A digital data transmission apparatus includes a transmitting end (100) that includes: a binary/quadrary conversion unit (110) for converting a data stream; a coding unit (120) for mapping the converted data to be coded; a digital filter (130); a D/A conversion unit (140); a low-pass filter (150) for eliminating a high-band signal; a differential driver (160) for inputting an analog signal that has passed through the low-pass filter into a twisted pair cable (300), and a receiving end (200) that includes: a low-pass filter (210) for eliminating noises from both wires of the twisted pair cable; a receiver (220) for receiving the signals that have passed through the low-pass filter; an A/D conversion unit (230); a digital filter (240); an evaluation unit (250) for evaluating a signal level of a received signal; a decoding unit (260) for decoding the signal level into receipt data; and a synchronization unit (270) for generating a clock.Type: GrantFiled: October 5, 2001Date of Patent: March 13, 2007Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Hirotsugu Kawada, Yuji Mizuguchi, Takahisa Sakai, Noboru Katta, Toshihiko Kurosaki
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Publication number: 20060291653Abstract: A data player for reading contents encrypted by a decoding key from a digital medium, and playing the encrypted contents by using the decoding key which is stored in a key storage unit, comprises: a key obtaining unit for performing mutual authentication with the key storage unit to obtain the decoding key stored in the key storage unit; a key holding unit for holding the decoding key; a playback state obtaining unit for monitoring the playback state of the digital medium; and a contents decoding unit for decoding the encrypted contents by using the decoding key. The decoding key is obtained by the key obtaining unit and stored in the key holding unit, and the encrypted contents read from the digital medium is decoded with the decoding key by the contents decoding unit to play the contents. The decoding key stored in the key holding unit is discarded according to the playback state of the digital medium which is obtained by the playback state obtaining unit.Type: ApplicationFiled: August 30, 2006Publication date: December 28, 2006Inventors: Hirotsugu Kawada, Noboru Katta, Susumu Ibaraki, Makoto Tatebayashi, Shunji Harada
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Publication number: 20060291652Abstract: A data player for reading contents encrypted by a decoding key from a digital medium, and playing the encrypted contents by using the decoding key which is stored in a key storage unit, comprises: a key obtaining unit for performing mutual authentication with the key storage unit to obtain the decoding key stored in the key storage unit; a key holding unit for holding the decoding key; a playback state obtaining unit for monitoring the playback state of the digital medium; and a contents decoding unit for decoding the encrypted contents by using the decoding key. The decoding key is obtained by the key obtaining unit and stored in the key holding unit, and the encrypted contents read from the digital medium is decoded with the decoding key by the contents decoding unit to play the contents. The decoding key stored in the key holding unit is discarded according to the playback state of the digital medium which is obtained by the playback state obtaining unit.Type: ApplicationFiled: August 30, 2006Publication date: December 28, 2006Inventors: Hirotsugu Kawada, Noboru Katta, Susumu Ibaraki, Makoto Tatebayashi, Shunji Harada
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Publication number: 20060285687Abstract: A data player for reading contents encrypted by a decoding key from a digital medium, and playing the encrypted contents by using the decoding key which is stored in a key storage unit, comprises: a key obtaining unit for performing mutual authentication with the key storage unit to obtain the decoding key stored in the key storage unit; a key holding unit for holding the decoding key; a playback state obtaining unit for monitoring the playback state of the digital medium; and a contents decoding unit for decoding the encrypted contents by using the decoding key. The decoding key is obtained by the key obtaining unit and stored in the key holding unit, and the encrypted contents read from the digital medium is decoded with the decoding key by the contents decoding unit to play the contents. The decoding key stored in the key holding unit is discarded according to the playback state of the digital medium which is obtained by the playback state obtaining unit.Type: ApplicationFiled: August 30, 2006Publication date: December 21, 2006Inventors: Hirotsugu Kawada, Noboru Katta, Susumu Ibaraki, Makoto Tatebayashi, Shunji Harada
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Publication number: 20060285688Abstract: A data player for reading contents encrypted by a decoding key from a digital medium, and playing the encrypted contents by using the decoding key which is stored in a key storage unit, comprises: a key obtaining unit for performing mutual authentication with the key storage unit to obtain the decoding key stored in the key storage unit; a key holding unit for holding the decoding key; a playback state obtaining unit for monitoring the playback state of the digital medium; and a contents decoding unit for decoding the encrypted contents by using the decoding key. The decoding key is obtained by the key obtaining unit and stored in the key holding unit, and the encrypted contents read from the digital medium is decoded with the decoding key by the contents decoding unit to play the contents. The decoding key stored in the key holding unit is discarded according to the playback state of the digital medium which is obtained by the playback state obtaining unit.Type: ApplicationFiled: August 30, 2006Publication date: December 21, 2006Inventors: Hirotsugu Kawada, Noboru Katta, Susumu Ibaraki, Makoto Tatebayashi, Shunji Harada
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Patent number: 7133936Abstract: A ring-shaped network quickly performs initialization even when a plurality of data transmission apparatuses are connected thereto. Each data transmission apparatus outputs received data to a device connected thereto while performing establishment of clock synchronization based on the received data, and when synchronization is established, it resends the received data. Further, when synchronization of the connected device is established, it sends data supplied from the connected device. Further, a master data transmission apparatus outputs data at turn-on of power or immediately after reset, and a next-stage slave data transmission apparatus receives the data to establish synchronization, and resends the received data when synchronization is established. Thus, synchronization of all the data transmission apparatuses is established while making a round of this data, and then synchronization of devices connected to the respective data transmission apparatuses is established.Type: GrantFiled: October 5, 2001Date of Patent: November 7, 2006Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Noboru Katta, Yuji Mizuguchi, Takahisa Sakai, Hirotsugu Kawada, Toshihiko Kurosaki, Nobuhiko Yasui, Yutaka Takahira
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Patent number: 7120251Abstract: A data player for reading contents encrypted by a decoding key from a digital medium, and playing the encrypted contents by using the decoding key which is stored in a key storage unit, comprises: a key obtaining unit for performing mutual authentication with the key storage unit to obtain the decoding key stored in the key storage unit; a key holding unit for holding the decoding key; a playback state obtaining unit for monitoring the playback state of the digital medium; and a contents decoding unit for decoding the encrypted contents by using the decoding key. The decoding key is obtained by the key obtaining unit and stored in the key holding unit, and the encrypted contents read from the digital medium is decoded with the decoding key by the contents decoding unit to play the contents. The decoding key stored in the key holding unit is discarded according to the playback state of the digital medium which is obtained by the playback state obtaining unit.Type: GrantFiled: August 18, 2000Date of Patent: October 10, 2006Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Hirotsugu Kawada, Noboru Katta, Susumu Ibaraki, Makoto Tatebayashi, Shunji Harada
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Publication number: 20060165194Abstract: The data sending device (10) receives input biphase-mark-encoded sending data which is output from an apparatus on the sending side, and a biphase decoding section (12) biphase-mark-decodes the input sending data. The output data from the biphase decoding section (12) is transmitted to a data receiving device via a sending section (14). On the other hand, the data receiving device biphase-mark-encodes the data received from the data sending apparatus (10) and then supplies the data to an apparatus on the receiving side.Type: ApplicationFiled: January 28, 2004Publication date: July 27, 2006Inventors: Yuji Mizuguchi, Nobuhiko Yasui, Noboru Katta, Takahisa Sakai, Yutaka Takahira, Hirotsugu Kawada, Toshitomo Umei, Takashi Akita
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Publication number: 20060155816Abstract: A data transmission device (1a) generates and transmits a lock signal for establishing clock synchronization with data transmission devices (1b-n). The data transmission device (1a) is capable of generating a pattern 1 lock signal for giving a notice of start of communication by use of data subjected to eight-value mapping, and a pattern 2 lock signal for giving a notice of start of communication by use of data subjected to four-value mapping. One of the two types of lock signals is transmitted to each data transmission device. Determining which lock signal has been received enables each data transmission device to give a notice of data communication method prior to training.Type: ApplicationFiled: December 24, 2003Publication date: July 13, 2006Inventors: Toshitomo Umei, Noboru Katta, Nobuhiko Yasui, Takahisa Sakai, Yuji Mizuguchi, Yutaka Takahira, Hirotsugu Kawada, Takashi Akita
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Publication number: 20060129318Abstract: To a data reception device, a signal having a frequency of 12.5 MHz and including data is transmitted. The data reception device generates a clock B having a frequency of 400 MHz of (1) in FIG. 8, and performs sampling for the above-described 12.5 MHz signal based on the clock B ((2) in FIG. 8). Then, the data reception device detects zero cross points of the sampled data, and generates a 25 MHz frequency clock signal indicating the zero cross points ((3) in FIG. 8). Next, the data reception device generates, by delaying the generated clock signal by the time amount corresponding to eight clocks ((4) in FIG. 8), a 25 MHz signal indicating symbol points. Thus, symbol points can be detected.Type: ApplicationFiled: December 26, 2003Publication date: June 15, 2006Inventors: Yuji Mizuguchi, Nobuhiko Yasui, Noboru Katta, Takahisa Sakai, Yutaka Takahira, Hirotsugu Kawada, Toshitomo Umei, Takashi Akita, Takefumi Yoshikawa, Shiro Dosho
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Patent number: 7042965Abstract: An evaluation level setting method and a data reception apparatus in which the method is implemented accurately evaluate signal levels in multi-valued transmission for transmitting data while assigning one or more bits of data as one data symbol to a signal level. A data transmission apparatus outputs an initialization pattern signal at turn-on of power or after reset, and the data reception apparatus establishes clock synchronization on the basis of the received initialization pattern signal and starts data reception after setting of evaluation levels to be used for threshold evaluation of signal levels.Type: GrantFiled: October 5, 2001Date of Patent: May 9, 2006Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Noboru Katta, Yuji Mizuguchi, Takahisa Sakai, Hirotsugu Kawada, Toshihiko Kurosaki
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Publication number: 20060072624Abstract: In the case where transmission and reception is made impossible at a certain portion, a data transmission system configured in a ring LAN performs an initialization process for a physical layer (a transmission/reception section 4) repeatedly, thereby setting as a master a data transmission device which is located most upstream in electrical communication from a disconnection point. With that data transmission device being the master, an initial setting of the physical layer such as a clock synchronization with another data transmission device or the like is established, and an initialization process for a data link layer is performed, whereby subsequent data transmission and reception is enabled. That is, the data transmission system configured in a ring LAN is able to perform communication using transmission lines excluding a damaged point even in the case where transmission and reception is made impossible at a certain portion.Type: ApplicationFiled: January 29, 2004Publication date: April 6, 2006Inventors: Takashi Akita, Noboru Katta, Nobuhiko Yasui, Takahisa Sakai, Yuji Mizuguchi, Yutaka Takahira, Hirotsugu Kawada, Toshitomo Umei
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Patent number: 7012936Abstract: A first initialization pattern signal is a signal in which a maximum signal level and a minimum signal level appear alternately, and a second initialization pattern signal is a signal in which all signal levels appear in a predetermined arrangement. In a ring-shaped network including plural stages of data transmission apparatuses (100), a transmission unit (110) of each data transmission apparatus outputs the first initialization pattern signal successively to a next-stage data transmission apparatus at turn-on of power or immediately after reset, and a reception unit (120) establishes clock synchronization on the basis of the first initialization pattern signal received.Type: GrantFiled: October 5, 2001Date of Patent: March 14, 2006Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Hirotsugu Kawada, Yuji Mizuguchi, Takahisa Sakai, Noboru Katta, Toshihiko Kurosaki, Nobuhiko Yasui, Yutaka Takahira
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Publication number: 20060050820Abstract: A signal receiver (11) receives an analog signal via a twisted pair cable (31). An A/D converter (12) converts the analog signal to a digital signal. A phase detection unit (14) detects the phase of the digital signal, and generates a reception timing signal. A transmission timing generation unit (15) controls, based on the reception timing signal, timing for a transmission processing unit (16) to output the digital signal such that the reception signal (point A) and a transmission signal (point D) are different in phase by a predetermined degree. The transmission processing unit (16) outputs, in accordance with the timing, a digital signal obtained by performing mapping on data inputted from a connection device (20). A D/A converter (17) converts the digital signal to an analog signal. A signal transmitter (18) transmits the analog signal via a twisted pair cable (32).Type: ApplicationFiled: February 10, 2004Publication date: March 9, 2006Inventors: Hirotsugu Kawada, Yoshiyuki Saito, Osamu Shibata, Hiroshi Suenaga, Takahisa Sakai, Toshitomo Umei, Takashi Akita, Yuji Mizuguchi, Noboru Katta
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Publication number: 20060034388Abstract: A data section is mapped such that the polarity of the signal level of each symbol is constantly inverted on a symbol by symbol basis. On the other hand, a header section is mapped such that the header section includes a distinguishing symbol for distinguishing the data section and the header section from each other, and such that the signal level of the distinguishing symbol is equal to the signal level of the symbol which is mapped immediately before the distinguishing symbol. Thus, data transfer, by which the header section and the data section can be distinguished from each other with certainty by an apparatus on the receiving side, is made possible.Type: ApplicationFiled: January 28, 2004Publication date: February 16, 2006Inventors: Yuji Mizuguchi, Nobuhiko Yasui, Noboru Katta, Takahisa Sakai, Yutaka Takahira, Hirotsugu Kawada, Toshitomo Umei, Takashi Akita
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Patent number: 6992537Abstract: A receiver includes a noise reduction circuit for eliminating noise from a differential signal transmitted through a differential transmission line, and a data recovery circuit for recovering data from a differential signal outputted from the noise reduction circuit. The noise reduction circuit includes common-mode chokes for reflecting common-mode noise superimposed on an input differential signal, and a common-mode noise reduction circuit for directing the common-mode noise reflected by the common-mode chokes to a low potential point of the common-mode noise reduction circuit.Type: GrantFiled: December 27, 2002Date of Patent: January 31, 2006Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Nobuhiko Yasui, Noboru Katta, Takahisa Sakai, Yuji Mizuguchi, Yutaka Takahira, Hirotsugu Kawada, Toshitomo Umei, Takashi Akita, Osamu Shibata