公开(公告)号：US4736238A

公开(公告)日：1988-04-05

申请号：US941242

申请日：1986-12-12

申请人： Yoshiaki Moriyama ,  Sumitaka Matsumura ,  Kaname Abe ,  Akihiro Ono ,  Kenji Yamagata ,  Toshio Gotoh

发明人： Yoshiaki Moriyama ,  Sumitaka Matsumura ,  Kaname Abe ,  Akihiro Ono ,  Kenji Yamagata ,  Toshio Gotoh

IPC分类号： H04N9/804 ,  H04N5/92 ,  H04N9/79 ,  H04N9/808 ,  H04N9/82 ,  H04N9/85 ,  H04N9/87 ,  H04N9/873 ,  H04N9/88 ,  H04N9/896 ,  H04N9/45

CPC分类号： H04N9/8205 ,  H04N9/7904 ,  H04N9/87 ,  H04N9/873 ,  H04N9/88

摘要： A digital television circuit in which the analog FM video signal is first digitized and all processing is performed digitally, including FM demodulation. Clocks at the subcarrier frequency and four times this frequency are synchronized with the horizontal synchronizing circuit or color burst signal.

摘要翻译： 数字电视电路，其中模拟FM视频信号被首先数字化，并且所有处理都是以数字方式进行的，包括FM解调。 副载波频率和频率四倍的时钟与水平同步电路或色同步信号同步。

公开(公告)号：US4656432A

公开(公告)日：1987-04-07

申请号：US791164

申请日：1985-10-24

申请人： Sumitaka Matsumura

发明人： Sumitaka Matsumura

IPC分类号： H03D3/06 ,  H03D3/00 ,  H03D3/04

CPC分类号： H03D3/007 ,  H03D2200/008 ,  H03D3/006

摘要： An FM detector includes a Hilbert transforming means and a pair of detector circuits which respectively detect an input FM signal and a Hilbert transform of the input FM signal produced by the Hilbert transforming circuit. Output signals of the two detector circuits are applied to a combining circuit, such as an adder circuit, to provide a detection output signal. With this construction, a second harmonic component which is inevitably produced during the detection operation is cancelled, so that a detector output signal, free of the so-called Aliasing distortion, is obtained even if an overlap between the baseband component and the second harmonic component occurs. Further, the gain characteristic of the detector is greatly improved.

摘要翻译： FM检测器包括希尔伯特变换装置和一对检测器电路，其分别检测由希尔伯特变换电路产生的输入FM信号的输入FM信号和希尔伯特变换。 两个检测器电路的输出信号被施加到诸如加法器电路的组合电路，以提供检测输出信号。 利用这种结构，消除了在检测操作期间不可避免地产生的二次谐波分量，使得即使基带分量和二次谐波分量之间的重叠也可以获得没有所谓的混叠失真的检测器输出信号 发生。 此外，检测器的增益特性大大提高。

公开(公告)号：US4245245A

公开(公告)日：1981-01-13

申请号：US654721

申请日：1976-02-02

申请人： Katsuaki Matsumoto ,  Yoshifumi Saeki ,  Osamu Tazawa ,  Minoru Kosaka ,  Masaki Saito ,  Hiroki Uemura ,  Tetuo Kanazashi ,  Seiji Hashimoto ,  Tsuyoshi Fujiwara ,  Tsutomu Fukui ,  Saburo Takaoka ,  Tsutomu Suzuki ,  Shozo Nakamuta ,  Toshihiko Hosaka ,  Kuniaki Shiratori ,  Youichiro Tsuda ,  Takashi Morii ,  Sumitaka Matsumura ,  Morihisa Oka

发明人： Katsuaki Matsumoto ,  Yoshifumi Saeki ,  Osamu Tazawa ,  Minoru Kosaka ,  Masaki Saito ,  Hiroki Uemura ,  Tetuo Kanazashi ,  Seiji Hashimoto ,  Tsuyoshi Fujiwara ,  Tsutomu Fukui ,  Saburo Takaoka ,  Tsutomu Suzuki ,  Shozo Nakamuta ,  Toshihiko Hosaka ,  Kuniaki Shiratori ,  Youichiro Tsuda ,  Takashi Morii ,  Sumitaka Matsumura ,  Morihisa Oka

IPC分类号： H04N7/167 ,  H04N7/171 ,  H04N7/173 ,  H04N7/16 ,  H04N7/00

CPC分类号： H04N7/17309 ,  H04N7/17363 ,  H04N2007/17372

摘要： A two-way CATV system having a substantial number of terminals incorporates a central processor and transmitter system which continually interrogates the terminals at high speed, monitoring changes of usage of premium programs and other data while also permitting central control of access to restricted premium programs. For inexpensive but reliable intercommunication, short, fixed word length digital messages are frequency multiplexed onto the cable in both upstream and downstream directions, and subscriber groups are controllably selected in turn, with each subscriber being scanned in what may be an arbitrary order by transmission of unique private messages which are recognized at the terminal and in response to which previously prepared fixed length messages are immediately transmitted in return. By employing both upstream and downstream messages which are initiated by a series of synchronizing bits and non-ambiguously related subsequent data sequences, and by the provision of means to initiate both downstream and upstream messages of short length without delay, rapid but reliable data interchange is effected despite differences in transmission and response times with different subscribers. Concurrently, terminal status and various special conditions including security alarms are remotely processed at each terminal, and short upstream messages are assembled containing priority selected data to be transmitted in response to an interrogation. The system incorporates additional means for monitoring power status, program selection and authorization and other operating conditions at each terminal effectively to provide accurate and reliable accounting information while preventing unauthorized or improper usage of restricted premium programs.

摘要翻译： 具有大量终端的双向CATV系统包括中央处理器和发射机系统，其以高速度连续询问终端，监视高级节目和其他数据的使用的改变，同时还允许对受限优惠节目的访问的中央控制。 对于廉价但可靠的互通，短，固定字长数字消息在上行和下行两个方向上被频率复用到电缆上，并且用户组可以依次可控地选择，每个用户以任意顺序扫描可以通过传输 在终端被识别并且响应于先前准备好的固定长度的消息被立即发送的唯一私人消息。 通过采用由一系列同步位和非相关相关的后续数据序列发起的上行和下行消息，并且通过提供无延迟地启动短长度的下行和上行消息的装置，快速但可靠的数据交换是 尽管与不同用户的传输和响应时间有差异。 同时，终端状态和包括安全警报在内的各种特殊条件在每个终端进行远程处理，并且组合短的上游消息，其中包含响应于询问要发送的优先选择数据。 该系统包括用于监控每个终端的电源状态，程序选择和授权以及其他操作条件的其他手段，有效地提供准确可靠的会计信息，同时防止未经授权或不正确使用限制性溢价程序。