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1. 发明专利

JPS63122291A LIGHT OUTPUT STABILIZING CIRCUIT 失效
公开(公告)号：JPS63122291A
公开(公告)日：1988-05-26
申请号：JP26765986
申请日：1986-11-12
申请人： HITACHI LTD , HITACHI SHONAN DENSHI
发明人： MINAE YASUO , UEHARA HIDEO , NEBIYA HIDEYUKI , KUDO YOSHIHIRO , AZUMA KOICHIRO
IPC分类号： H04B10/293 , H01S5/068 , H01S5/0683 , H04B10/07 , H04B10/564 , H04B10/572
摘要： PURPOSE:To obtain a light output which is stable to dispersion of elements and a characteristic change to temperatures, by dividing this circuit into a high-speed differential amplification circuit for signal current amplification and an emitter follower circuit for supplying a bias current and a signal current and performing feedback control of a collector potential in the differential amplification circuit. CONSTITUTION:Assuming that light output of semiconductor laser 11 has increased, a current flowing across a light detecting element 12 is increased and also a voltage generated across a resistor 13 is raised. However, because a d-c polarity is inverted in an inversion d-c amplifier 15, an output voltage of a d-c adder 17 is decreased in comparison with the voltage which is obtained before the light output increases. Noises are removed from this voltage through an integrator 18 and this voltage is applied to a base of a transistor 19. This operation corresponds to the lowering of a transistor 19's emitter voltage VE. When the emitter voltage VE is lowered, an emitter current 16 is also decreased and so the light output is suppressed. The light signal of a constant output generated by this control is sent outside through an optical fiber 14.

2. 发明专利

JPS6253538A SIMPLE RADIO COMMUNICATION EQUIPMENT FOR NETWORK BETWEEN DIGITAL DEVICES 失效
公开(公告)号：JPS6253538A
公开(公告)日：1987-03-09
申请号：JP19321585
申请日：1985-09-03
申请人： HITACHI SHONAN DENSHI
发明人： NEBIYA HIDEYUKI , SUGA KOJI , KUDO YOSHIHIRO , OKAMURA MASAYA , AZUMA KOICHIRO
IPC分类号： H04L5/14
摘要： PURPOSE:To simplify a circuit and to apply radio communication by using a saturation amplifier circuit comprising an inverter and a waveform shaping circuit. CONSTITUTION:The S/N of a radio wave received by a reception antenna 5 is improved through a reception film 6 and rectified by a detection diode 7. The DC component of the signal is cut off by a capacitor 8 and the result is inputted to an inverter 9. The input to the inverter 9 is biased to a half of an output voltage difference corresponding to levels '1' and '0' by a feedback resistor 10. The bias point is subjected to the provision of high gain by the inverter, saturation amplification and the result is inputted to a waveform shaping circuit 11, the waveform as a digital signal is shaped, inputted to other digital device 1' for communication. Thus, the circuit constitution is simplified.

3. 发明专利

JPS6253551A DEMODULATION CIRCUIT FOR DIGITAL DATA SUBJECTED TO FREQUENCY MODULATION 失效
公开(公告)号：JPS6253551A
公开(公告)日：1987-03-09
申请号：JP19321785
申请日：1985-09-03
申请人： HITACHI SHONAN DENSHI
发明人： KUDO YOSHIHIRO , NEBIYA HIDEYUKI , AZUMA KOICHIRO , MIYAZAWA TOMOYUKI
IPC分类号： H04L27/148 , H04L27/14
摘要： PURPOSE:To miniaturize the circuit constitution by using a voltage comparator to compare an output of a frequency-voltage conversion circuit with an output of a reference setting circuit and outputting the result to improve the communication efficiency when FSK communication is applied, where a data transmission rate and a FSK carrier frequency are adjacent comparatively. CONSTITUTION:The FSK wave inputted from an input terminal 1 is bisected at a signal branch point 2. The signal fed to the frequency-voltage conversion circuit is received by a buffer amplifier 3, inputted to an active low-pass filter 5, subjected to amplitude limit at each frequency and becomes a signal corresponding to digital data by a detection circuit 6. On the other hand, the signal is received by a buffer amplifier 4 in a reference voltage generating circuit, the result is detected by a detection circuit 7, attenuated by an attenuator 8 comprising resistors and a reference voltage proportional to the input signal level is obtained. The bisected voltage is inputted and compared by a voltage comparator 9 to recover accurate data. Thus, the circuit is miniaturized to improve the demodulation efficiency and the circuit constitution is miniaturized.

4. 发明专利

JPS61257050A PSK MODULATION CIRCUIT 失效
公开(公告)号：JPS61257050A
公开(公告)日：1986-11-14
申请号：JP9803485
申请日：1985-05-10
申请人： HITACHI SHONAN DENSHI
发明人： AZUMA KOICHIRO
IPC分类号： H04L27/20
摘要： PURPOSE:To lower a consumed power, to make compact a circuit scale and to decrease a loss in the circuit by using an FET in a PSK demodulation circuit in a transmission line of a responding system using the same carrier wave. CONSTITUTION:In a strip line, in accordance with a termination condition, a reflected wave having a different phase with respect to an incident wave is produced. When the termination is opened, the reflected wave of the in-phase is produced and in the case of a short circuit, the reflected wave of an opposite phase having a phase difference of 180 deg. is generated. Accordingly, when a control signal is applied to an input terminal 5 in a response station, a control voltage is impressed to a gate G of the FET 8 through a high frequency noise removing low-pass filter 4 constituted by the strip lines. Thereby, in the termination of a matching section 7 constituted by the strip lines with respect to the incident carrier wave from a base station of the response system receiving from an antenna 1, correspondingly to an inoperative time or an operative time of the FET 8, the in-phase or the opposite phase reflected wave is generated. Thereby, a PSK modulated signal wave is transmitted to the base station from the antenna 1 through the matching section 7.

5. 发明专利

JP2002111595A OPTICAL RECEIVER 失效
公开(公告)号：JP2002111595A
公开(公告)日：2002-04-12
申请号：JP2000336699
申请日：2000-09-29
申请人： HITACHI SHONAN DENSHI
发明人： AZUMA KOICHIRO
IPC分类号： H03F3/08 , H04B10/07 , H04B10/293 , H04B10/40 , H04B10/50 , H04B10/564 , H04B10/572 , H04B10/60 , H04B10/67 , H04B10/69 , H04L25/03 , H04B10/14 , H04B10/04 , H04B10/06 , H04B10/26 , H04B10/28
摘要： PROBLEM TO BE SOLVED: To surely carry out identification, even when a non-signal period continues. SOLUTION: A peak level detection circuit 4 detects the peak level of the positive phase signals of differential output from a preamplifier 2, outputs it to a subtractor 6 and outputs the positive phase signals of a subtracted value to an identifier 3. The peak level detection circuit 5 detects the peak level of the negative phase signals of the differential output from the preamplifier 2, outputs it to an adder 7 and outputs the negative phase signals of an added value to the identifier 3.

6. 发明专利

JPH03136419A OPTICAL RECEIVER 失效
公开(公告)号：JPH03136419A
公开(公告)日：1991-06-11
申请号：JP27373889
申请日：1989-10-23
申请人： HITACHI SHONAN DENSHI
发明人： AZUMA KOICHIRO
IPC分类号： H01L31/107 , H04B10/079 , H04B10/293 , H04B10/564 , H04B10/572
摘要： PURPOSE:To constitute the receiver with a simple circuit and a comparatively small size by detecting a mean current flowing to the avalanche photodiode (APD) and controlling a high voltage generating circuit with a detected signal so as to make the output current of the APD constant. CONSTITUTION:A man current flowing to an APD 11 is detected by a mean current detector 14 and the detection signal is inputted to a high voltage generating circuit 12 via an amplifier 13. A voltage applied to the APD 11 from the high voltage generating circuit 12 is changed by the detection signal, the current multiplier rate of the APD 11 is controlled and the output current of the APD 11 is made stable. Then the output signal from the stabilized APD 11 is amplified by a preamplifier 15 and inputted to a timing detection circuit 17 and an identification circuit 18, in which the signal is separated into a timing signal and an information signal and outputted. Thus, since no AGC loop circuit is formed, the comparatively small and simple circuit constitution is attained.

7. 发明专利

JPH10242816A PULSE WIDTH ADJUSTING CIRCUIT 失效
公开(公告)号：JPH10242816A
公开(公告)日：1998-09-11
申请号：JP4036297
申请日：1997-02-25
申请人： HITACHI LTD , HITACHI SHONAN DENSHI
发明人： ARAI TAKATERU , SUZUKI MUNETOSHI , TAKANO MITSUHIRO , TAKAHASHI YASUSHI , AZUMA KOICHIRO
IPC分类号： H03K5/04 , H04B10/2507 , H04B10/40 , H04B10/50 , H04B10/58 , H04B10/60 , H04B10/04 , H04B10/06 , H04B10/14 , H04B10/26 , H04B10/28
摘要： PROBLEM TO BE SOLVED: To correct the waveform distortion of a light signal due to the rise delay of the light signal with simple constitution by applying a variable comparison reference voltage to a buffer amplifier and adjusting the pulse width when an input signal having its signal waveform rise and fall slanted by using a filter circuit is shaped through the buffer amplifier. SOLUTION: The input signal is inputted to an input terminal 11A of a filter circuit 11 to obtain an output 11B whose digital signal waveform rise and fall are slanted, and the output is inputted to the uninverted input terminal 12A of a buffer amplifier circuit 12. The buffer amplifier circuit 12 outputs a reference voltage 12C which is internally compensated according to a driving power source, so the voltage divided by it through resistances R12 to R14 is inputted as the comparison reference voltage to the inverted input terminal 12B. The uninverted and inverted outputs 12D and 12E of the buffer amplifier 12 are inputted to the uninverted and inverted input terminals 13A and 13B of a light emitting element driving circuit 13 to drive a light emitting element 14.

8. 发明专利

JPS6253550A DIGITAL DATA TRANSMISSION CIRCUIT 失效
公开(公告)号：JPS6253550A
公开(公告)日：1987-03-09
申请号：JP19321685
申请日：1985-09-03
申请人： HITACHI SHONAN DENSHI
发明人： AZUMA KOICHIRO , SUGA KOJI , NEBIYA HIDEYUKI , KUDO YOSHIHIRO , OKAMURA MASAYA
IPC分类号： H04L27/04 , H04L27/06
摘要： PURPOSE:To miniaturize the titled device, to simplify the circuit and to reduce power consumption by providing a digital transmitter and a digital receiver. CONSTITUTION:The DC component is cut off by a capacitor 10 in a saturation amplifier circuit 8 and a data is inputted to a saturation amplifier circuit section comprising an inverter 13. The input to the inverter 13 is biased to a voltage between H and L levels of a digital data output to form a high gain point of the inverter thereby changing minutely the input signal, which is subject to saturation amplifier. The amplified digital data is waveform-shaped as a digital data inputted to a digital equipment 1' by a waveform shaping circuit 9 and the result is inputted to the digital equipment 1'. Thus, miniaturization, low power consumption and simplicity of the circuit are attained.

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