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1. 发明专利

JPH01106547A SYNCHRONIZING SIGNAL GENERATING CIRCUIT 失效
公开(公告)号：JPH01106547A
公开(公告)日：1989-04-24
申请号：JP26314087
申请日：1987-10-19
申请人： YAGI ANTENNA , HITACHI LTD
发明人： MORIFUJI MOTOYOSHI , KOYAMA KATSUTO , TERADA MATSUAKI , FUKUZAWA JUNJI
IPC分类号： H04L27/06
摘要： PURPOSE:To make stable synchronizing signals always generable by reducing the zero-amplitude component of demodulated signal and producing the synchronizing signals by using only trigger signals at the time of phase changes. CONSTITUTION:The synchronizing signal generating circuit 21 which generates synchronizing signals against demodulated signals of an amplitude-phase demodulation (AM-PSK demodulation) system using three values of '0' and + or -in phase and '0' in amplitude, is composed of a low-pass filter 31, comparator 32, trigger generating circuit 33, frequency dividing circuit 34, and oscillation circuit 35. The synchronizing signals are produced by using only trigger signals at the time of phase changes by reducing the zero-component of the demodulated signals by means of the low-pass filter 31. Therefore, no period disturbance takes place when the amplitude of the demodulated signals is reduced and stable synchronizing signals can always be produced.

2. 发明专利

JPS63292748A MODULATION CIRCUIT 失效
公开(公告)号：JPS63292748A
公开(公告)日：1988-11-30
申请号：JP12772387
申请日：1987-05-25
申请人： YAGI ANTENNA , HITACHI LTD
发明人： MORIFUJI MOTOYOSHI , KANEKO YOICHI , TERADA MATSUAKI , FUKUZAWA JUNJI
IPC分类号： H03C1/58 , H04L27/00 , H04L27/36
摘要： PURPOSE:To prevent the spread of a spectrum by providing a gate circuit decoding a base band pulse signal and a low pass filter so as to easily realize the multi-level modulation of the amplitude and phase. CONSTITUTION:The titled circuit is provided with a ring modulation circuit 41 modulating a carrier signal based on two kinds of base band pulse signals S1, S2, a gate circuit 42 applying multi-level modulation to the phase and amplitude of a carrier signal in response to the combination of the base band pulse signals S1, S2 and a low pass filter 43 provided between the ring modulation circuit 41 and the gate circuit 42. Thus, the multi-level modulation of the phase and amplitude including the on/off control of the carrier signal is realized with a simple constitution and the spread of spectrum of the carrier signal after modulation is prevented.

3. 发明专利

JPS63127631A BASE BAND/BROAD BAND COEXISTING SYSTEM 失效
公开(公告)号：JPS63127631A
公开(公告)日：1988-05-31
申请号：JP27442386
申请日：1986-11-18
申请人： HITACHI LTD , YAGI ANTENNA
发明人： HIRATA TETSUHIKO , YAGYU KAZUO , TERADA MATSUAKI , NAKASE HIROMU , OSHIMA SHIGERU , MORIFUJI MOTOYOSHI , NISHIZAWA TAKAHIKO
IPC分类号： H04J1/00 , H04B14/00
摘要： PURPOSE:To attain the coexistence of the base/broad band system by using a band of a frequency passing through a filtering means for the base band and using the frequency band to be cut for a broad band. CONSTITUTION:A translator unit TU 3 has a function converting a broad band signal f1 (incoming signal to the TU 3) into a signal f2 (outgoing signal from the TU 3), a function of an FU 5, that is, a function cutting off the frequency component over the predetermined frequency, and a DC feeding function to the amplifier 11. A branching filter 7 cuts off only the DC in a transmission line 4 and passes the other signals. Through a main line of the transmission line, signals fc, f2 and DC flows in the outgoing direction and signals fc, f1 flow in the incoming direction. Thus, a data terminal equipment 6 applying communication by the base band system and a data terminal equipment 9 applying communication by the broad band system can be existed in common.

4. 发明专利

JPS63119330A LEVEL ADJUSTING DEVICE 失效
公开(公告)号：JPS63119330A
公开(公告)日：1988-05-24
申请号：JP26376886
申请日：1986-11-07
申请人： HITACHI LTD , YAGI ANTENNA
发明人： HIRATA TETSUHIKO , YAGYU KAZUO , TERADA MATSUAKI , MORIFUJI MOTOYOSHI , NISHIZAWA TAKAHIKO
IPC分类号： H04B3/04
摘要： PURPOSE:To uniformize the level of a reception high frequency signal by adjusting the level of a transmission high frequency signal in the terminal side to which the signal level measured by a head end frequency converter part is given as information. CONSTITUTION:The level of the up high frequency signal transmitted from each data terminal is measured by a level measuring circuit 6 provided in a frequency converter part 4. The measured level is reported back to each terminal by a device consisting of a microcomputer, a communication LSI, or the like. Each terminal to which its own transmission level is reported back controls a level adjusting attenuator by the microcomputer to set the transmission signal to a proper level and tries this level adjustment several times. Since it is unnecessary to provide a pilot signal generator in the frequency converter side and to provide each data terminal with a pilot signal detector, the circuit constitution of the data terminal is simplified and the cost is reduced.

5. 发明专利

JPS6284637A SIGNAL COLLISION DETECTION SYSTEM 失效
公开(公告)号：JPS6284637A
公开(公告)日：1987-04-18
申请号：JP22536785
申请日：1985-10-09
申请人： YAGI ANTENNA , HITACHI LTD
发明人： MORIFUJI MOTOYOSHI , NISHIZAWA TAKAHIKO , TERADA MATSUAKI , YAGYU KAZUO
IPC分类号： H04L12/40
摘要： PURPOSE:To detect a signal collision at low cost with high precision by detecting whether there is a down high frequency signal received from the computer of another station through a coaxial cable for the 1st time when data from each computer is transmitted, and transmitting the data with an up high frequency signal unless there is the high frequency signal of another station on the coaxial cable. CONSTITUTION:A pulse signal is normally inputted to a processing part as effective data when the pulse signal is communication data of another computer or this computer and the waveform 103 of a carrier detecting circuit 56 is '1', but if a collision occurs, a pulse Y7 is outputted to a line 422 to make the data ineffective and the transmission is interrupted immediately when the data is transmitted. Then, when there is no down high frequency signal, namely, when the output of the carrier detecting circuit 56 is '0', the unmodulated up high frequency signal is transmitted again to confirm that the collision does not occur, and the data is sent out to make a communication with another computer.

6. 发明专利

JPH01114241A DEMODULATION CIRCUIT 失效
公开(公告)号：JPH01114241A
公开(公告)日：1989-05-02
申请号：JP27213287
申请日：1987-10-28
申请人： YAGI ANTENNA , HITACHI LTD
发明人： MORIFUJI MOTOYOSHI , KOYAMA KATSUTO , FUKUZAWA JUNJI , TERADA MATSUAKI
IPC分类号： H04L27/156 , H04L27/14
摘要： PURPOSE:To demodulate a particular modulated wave where the combination form of switching time is changed, as well within the time of one bit by directly holding the output pulse of a reception circuit by a first shift register, and at the same time, inverting it, and holding it by a second shift register, and detecting it by a matrix circuit. CONSTITUTION:The output pulse of the reception circuit 22 is held directly by the first shift register 23, and at the same time, is inverted, and is held by the second shift register 27 as well, and '0', '1' of the data signal outputted by these shift registers 23, 27 is detected by the matrix circuit 28, and is demodulated through a gate circuit 29 and a latch circuit 30 into '0', '1' or a particular data signal corresponding to the output pulse of the reception circuit varying variously within one bit period of the data signal. Thus, by including this particular data in the transmission format of the data signal, the necessary data and a delimiter or a preamble indicating the start or the finish of the data can be easily distinguished, and the reliability of the contents of the data at the time of data transmission is improved.

7. 发明专利

JPH01106548A MODULATOR CIRCUIT 失效
公开(公告)号：JPH01106548A
公开(公告)日：1989-04-24
申请号：JP26313987
申请日：1987-10-19
申请人： YAGI ANTENNA , HITACHI LTD
发明人： MORIFUJI MOTOYOSHI , KOYAMA KATSUTO , TERADA MATSUAKI , FUKUZAWA JUNJI
IPC分类号： H04L27/12 , H04L27/10
摘要： PURPOSE:To make the modulated waveform of data signals having a peculiar pattern obtainable with a modulation circuit, by constituting the modulation circuit of the combination of a counter, decoder, matrix circuit, and gate circuit. CONSTITUTION:The modulation circuit of this invention is constituted of a counter 103, decoder circuit 104, matrix circuit 105, and gate circuit 106. Namely, a modulating pulse pattern corresponding to three data signals is formed and the modulating pulse pattern corresponding to the three data signals is switched at the gate circuit 106 and outputted through a filter 108. Therefore, the modulating waveform form of data signals becomes freely settable and easily changeable and the modulated waveform of data signals having a peculiar pattern other than ordinary 'H' and 'L' signals can be obtained. Accordingly, the complicated control, etc., of a reception station can be coped with by constituting complicated data formats.

8. 发明专利

JPS63290424A SYNCHRONIZING SIGNAL GENERATING CIRCUIT 失效
公开(公告)号：JPS63290424A
公开(公告)日：1988-11-28
申请号：JP12529087
申请日：1987-05-22
申请人： YAGI ANTENNA , HITACHI LTD
发明人： MORIFUJI MOTOYOSHI , KANEKO YOICHI , TERADA MATSUAKI , FUKUZAWA JUNJI
IPC分类号： H03L7/08 , H03K5/00 , H04L7/02 , H04L7/033
摘要： PURPOSE:To obtain a stable synchronizing signal even when an external input data including jitter is supplied by using a low pass filter so as to integrate the phase change, and relaxing the control of a VCO. CONSTITUTION:An external input data B is supplied to a differentiation circuit 101 and a D FF 109. The differentiation circuit 101 generates a differentiating pulse at the leading and trailing edges of the input data B, supplies it to a 1st frequency dividing circuit 104 as a reset pulse to allow the circuit 104 to output a signal A having the same period as the input data B. The signal A is subject to phase comparison with a signal C from a 2nd frequency divider circuit 108 by a phase comparing circuit 105 and its phase error is inputted to a control terminal of the VCO 107 via an integrating circuit 106. In such a case, the change in an output voltage D2 is made slow by the operation of the integrating circuit 106 and even when an external input data including jitter is supplied, a stable synchronizing signal is obtained.

9. 发明专利

JPS62115945A DATA COMMUNICATION CONTROL SYSTEM 失效
公开(公告)号：JPS62115945A
公开(公告)日：1987-05-27
申请号：JP25481185
申请日：1985-11-15
申请人： HITACHI LTD , YAGI ANTENNA
发明人： YAGYU KAZUO , TERADA MATSUAKI , HIRATA TETSUHIKO , NISHIZAWA TAKAHIKO
IPC分类号： H04L12/40
摘要： PURPOSE:To improve the throughput of a communication control board if necessary by optionally adding a board with a two-port memory accessible from a local processor and a one out of a station in common. CONSTITUTION:A coaxial cable 2 is installed in a hierarchical structure, on a frequency converter 1. A branch device for branching a signal is provided with a directional joint function which branches a down signal and flows only an up signal in a straight direction. LAN control boards 6a and 6b are connected to the cable out of the branch device, and are built in stations 5a and 5b, respectively. Each station is connected by the LAN of a CSMA/CD system at 2Mbps. Data is modulated into an up signal frequency, transmitted to a frequency converter 1, converted into a down signal frequency and transmitter to all stations. Thus an accelerating board is added to an LAN control board with the insifficient throughput in such a way, thereby improving the throughput.

10. 发明专利

JPS581361A DATA COMMUNICATION SYSTEM 失效
公开(公告)号：JPS581361A
公开(公告)日：1983-01-06
申请号：JP9821781
申请日：1981-06-26
申请人： HITACHI LTD , YAGI ANTENNA
发明人： NAKADA YUKIO , TERADA MATSUAKI , SUDA KAORU , MORIFUJI MOTOYOSHI , SHIOZU OSAMU
IPC分类号： H04B10/11 , H04B10/00 , H04B10/079 , H04B10/114 , H04B10/278 , H04B10/524 , H04L12/28 , H04L12/40
摘要： PURPOSE:To install a terminal or computer at a desired place easily, and to eliminate the congestion of cables, by coupling an optical transmitting and receiving means with a data processing means. CONSTITUTION:Transceivers TRX6-TRX9 receive data transmitted from corresponding terminal equipments 10-13, and impose intensity modulation upon infrared rays from LEDs 6-1-9-1 to converge and transmit the modulates waves to reflectors 4 and 5. They are photodetected and converted into data signals through photodiodes PD4-2 and PD5-2, and the data signals are sent out to a coaxial cable 3. Reflectors 4 and 5 having received the data from the cable 3 impose intensity modulation upon infrared rays of LEDs 4-1 and 5-1 to send the modulated waves to all TRXes in the room. The radiated waves are photodetected by PDs 6-2 and 9-2, and detected signals are supplied as data signals to the equipments 10-13.

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