Hitachi, Ltd.

Hitachi Engineering Co., Ltd.

Yasushi Yokosuka

Yasuyuki Kozima

Kazuhiko Takaoka

Kozo Nakamura

Kouzou Nakamura

Hideki Inoue

Kimiya Yamaashi

Yasuyuki Kojima

Dai Watanabe

Yoichi Sugita

Takeshi Asai

Yukihito Ishihara

Toru Yamada

Kiyoshi Chiba

Kagehiro Yamamoto

Takanori Yamasaki

Takeshi Shimanuki

An information-transmission system which uses non-geosynchronous artificial satellites, including a server-system and its client apparatuses, for performing communications or broadcast, the system comprises: a means for controlling changeover of a non-geosynchronous artificial satellite being used, to another satellite to be next used; wherein the server-system determines whether or not a satellite-changeover occurs during sending of an information packet to be sent toward a satellite being used, one of the non-geosynchronous artificial satellites; and if it is determined that a satellite-changeover occurs during sending of the information packet to be sent, the server-system or each client apparatus postpones sending of the information packet to be sent, and starts sending of the information packet to be sent, after the completion of the satellite-changeover; or repeatedly sends the information packet to be sent, until the completion of said satellite-changeover. Moreover, the server-system informs each satellite on at least one of the start time of, the time necessary for, and the end time of the satellite-changeover.

Information-transmission system which uses non-geosynchronous artificial satellites, including server-system and its clients, for performing communications or broadcast

Train control method and apparatus

An information transmission/reception apparatus having a reader for reading an image and outputting an image signal of the image, an encoder having a plurality of line memories for storing the image signal for encoding the image signal into a code signal while always confirming that the image signal of at least one line is stored in the line memories, a transceiver for transmitting and receiving the code signal, a decoder having a plurality of line memories for storing the image signal represented by the code signal, the decoder decoding an input code signal from one of a page top position and a page intermediate position, and a recorder for recording the image signal decoded by the decoder, thereby while an image signal is being decoded without using a page memory, a split or overlapping recording of pages can be carried out.

Image signal processing apparatus and information transmission/reception apparatus using the same

Image signal processing apparatus and information transmission/reception

A high-speed image signal processing system for encoding an image signal, read out at a high speed, into an encoded signal, and/or for recording a decoded signal obtained through a decoding operation on an encoded signal. The image signal, obtained through a scanning operation on an original document, is sent to an encoder through an image bus. A code bus, provided at an output of the encoder, is connected with an encoded-signal memory for storing the encoded signal. A code transfer unit, for performing input/output operation over the encoded signal and for performing transfer of the encoded signal from the code bus to a system bus, is disposed between the code bus and the system bus. A control unit, performing control over the entire system, and a document management data memory, storing management data for performing management over documents stored in the encoded-signal memory, are connected to the system bus. Further, the control unit, when receiving a request from a data input/output unit, issues a command indicative of the start of the encoding/decoding operation to the encoder/decoder. The encoder/decoder, when receiving the command from the control unit, sequentially processes the data from the data input/output unit without any intervention of the control unit, and when the data processing is completed, informs the control unit of the end of the data processing.

High-speed image signal processing system

An apparatus for decoding a coded image into a pixel image and printing the pixel image at an essentially constant speed without using decoding means which decodes the coded image faster than a printing speed and pixel memory means for storing at least one page of pixel information. Decoding amount calculation means for calculating the decoding amount of the code to be decoded is provided, and compare means monitors whether the decoding amount exceeds the printing amount of the pixels to be printed and the code is converted to other code depending on the comparison result. The decoding means needs only receive the converted code from the code memory means and decode it to the pixel information. Thus, the constant speed printing apparatus is attained without high speed decoding means and one-page memory.

Method and appratus for decoding and printing coded image, and facsimile

In a MODEM having modulation and demodulation circuits and a circuit for controlling the modulation and demodulation, a modulator-demodulator apparatus includes a register for accepting a macro-instruction from an external source; a circuit for interpreting and executing the macro-instruction; and a circuit for outputting a response to the macro-instruction, whereby the MODEM is controlled in response to the macro-instruction accepted from the outside source. The modulator-demodulator apparatus is suitably integrated over a single semiconductor substrate.

Modulator-demodulator apparatus and system

A modem (modulator-demodulator) apparatus provided with modem circuits having different signal processing standards, which is optimized for a facsimile machine. Switching of modem functions can be accurately performed by concurrently operating modems with required standards selected from modems with different standards incorporated in a modem apparatus and incorporating in a common input/output port means for selectively switching an input/output of each modem and a dedicated signal detection means required for the switching, and further by constituting a facsimile using the this modem apparatus so as to perform the switching control from the facsimile body or automatically. Moreover, the modem signal after switching can be obtained by using a low speed modem as dedicated signal detection means, detecting a flag pattern after having completed an initial sequence consisting of detection of the presence (power) of an input signal, automatic gain control (AGC), carrier reproduction (PLL), timing synchronization, etc. and deciding that a signal for receiving a low speed modem signal has been received on the condition that at least one of the flag pattern has been detected.

Multimode modem for facsimile

A first phase control loop not including a signal delay part and a second phase control loop including a signal delay part such as an automatic equalizer are formed independently of each other in a demodulator incorporated in a MODEM. The first and second phase control loops are arranged in such a relation that an input to the second phase control loop is not affected by an output of the first phase control loop, so that correction of a frequency offset by the first phase control loop and correction of a frequency jitter by the second phase control loop can be carried out independently of each other. This arrangement facilitates the design of the first and second phase control loops and improves the stability of the phase control system.

Phase control device

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Hitachi, Japan

Yasushi Yokosuka