专利快速检索-快速检索全球专利，免费商用专利数据库-IPRDB

81. 发明专利

JPH0983898A IF DEMODULATION CIRCUIT 失效
公开(公告)号：JPH0983898A
公开(公告)日：1997-03-28
申请号：JP23536095
申请日：1995-09-13
申请人： TOSHIBA CORP
发明人： SUZUKI OSAMU , OSADA TATSUO
IPC分类号： H04N5/455 , H03D1/04
摘要： PROBLEM TO BE SOLVED: To provide an IF demodulation circuit not employing a SAW filter. SOLUTION: A low pass filter 5 blocks an audio carrier (60.25MHz) of an adjacent channel of an IF signal or over to attenuate a level at a video intermediate frequency (58.75MHz) by -6dB. An IF processing section 4 demodulates the IF signal outputted from the low pass filter. A filter 6 traps an audio intermediate frequency (4.5MHz) and blocks adjacent channels (6.0MHz) or over as to the video signal outputted from the IF processing section and demodulated.

82. 发明专利

JPH08237207A SIGNAL PROCESSING CIRCUIT FOR PHOTOELECTRIC CONVERSION ELEMENT 失效
公开(公告)号：JPH08237207A
公开(公告)日：1996-09-13
申请号：JP3879795
申请日：1995-02-27
申请人： SHARP KK
发明人： OKUDA TAKANORI , YOKOGAWA SEIICHI
IPC分类号： H03D1/04 , H04B1/10 , H04B10/07 , H04B10/114 , H04B10/40 , H04B10/50 , H04B10/524 , H04B10/60 , H04B10/69 , H04L25/49 , H04Q9/00 , H04B10/28 , H04B10/04 , H04B10/06 , H04B10/14 , H04B10/26
摘要： PURPOSE: To precisely demodulate a modulated wave from the output of a photoelectric conversion element by preventing the activation of an integration circuit only for time which is previously decided from the restoration time of a pulse outputted from an output circuit. CONSTITUTION: An electric signal from a light-receiving element 22 is amplified by an amplifier circuit 23 and is filtered into only a transportation frequency component by BPF 24. Output from BPF 24 is discriminated from a prescribed level by waveform shaping circuits 25 and 26 and is waveform-shaped. Then, it is inputted to the integration circuit 27 and the component of a modulate wave is extracted by integration. Then, it is waveform-shaped by an output circuit 28 and outputted to a decoding circuit and a control circuit in a poststage. Output is masked by permitting a discharge current switching circuit 33 to short circuit terminals in the capacitor of the integration circuit 27 so as to prevent the activation in response to the output of the output circuit 28, for example. Thus, the malfunction of output by the feedback of the output pulse to the input-side of the amplifier circuit with voltage fluctuation is prevented and the modulated wave can precisely be demodulated.

83. 发明专利

JPH06276026A CONTIGUOUS DISTURBANCE DETECTING DEVICE FOR AMPLITUDE-MODULATED SIGNAL 失效
公开(公告)号：JPH06276026A
公开(公告)日：1994-09-30
申请号：JP5722893
申请日：1993-03-17
申请人： FUJITSU TEN LTD
发明人： SASAKI MITSURU
IPC分类号： H03D1/04 , H03D1/22
摘要： PURPOSE:To obtain the contiguous disturbance detecting device for the amplitude-modulated signal which can automatically be switched from disturbance of a contiguous channel and provides convenience to a user by providing with an intermediate frequency filter, a contiguous carrier detecting means, a low-pass filter, and a switch. CONSTITUTION:An independent sideband demodulator 20 which demodulates the intermediate frequency signal of the intermediate frequency filter 1 independently expands the band of the intermediate frequency filter 1 to a range including the carrier frequency of the contiguous channels. Contiguous carrier detecting means 21 and 22 input the upper side wave signal and lower side wave signal outputted by the independent sideband demodulator 20 respectively and detects a carrier of contiguous disturbance. Further, low-pass filters 23 and 24 input the modulated upper side wave signal and lower side wave signal respectively and remove the signal of the modulated carrier of the disturbance of the contiguous channels. Switches 25 and 26 switch the outputs of the low-pass filters 23 and 24 so as to output the opposite side wave signal from the side wave signal including the detected contiguous channel carrier signal.

84. 发明专利

JPH06252649A SYNCHRONIZATION DETECTING CIRCUIT 失效
公开(公告)号：JPH06252649A
公开(公告)日：1994-09-09
申请号：JP6119293
申请日：1993-02-25
申请人： ANDO ELECTRIC
发明人： TAKEDA TOSHIYUKI
IPC分类号： H03D1/04 , H03D1/06 , H03D1/22
摘要： PURPOSE:To obtain a synchronization detection circuit in which a signal from a detector is branched, one branched signal is subject to amplitude limit and the resulting signals are multiplied so as to eliminate distortion due to phase fluctuation of the signal. CONSTITUTION:A detector 1 detects an AM modulation signal 7 and an amplifier 2 amplifies an output signal 8 of the detector 1. A limiter circuit 3 applies amplitude limit to an output signal 10 of the amplifier 2 and a delay circuit 4 corrects the delay by the amplifier 2 and a delay by the limiter circuit 3 and then a propagation delay. A multiplier 5 multiplies the output signal 1 of the limiter circuit 3 and an output signal 9 of the delay circuit 4 and a low pass filter 6 applies band limit to an output signal 12 of the multiplier 5.

85. 发明专利

JPH05291832A 失效
公开(公告)号：JPH05291832A
公开(公告)日：1993-11-05
申请号：JP8539892
申请日：1992-04-07
申请人： PIONEER ELECTRONIC CORP
发明人： FUKUOKA SHINYA , ABE YOJIN , NUMATA MASAHIRO
IPC分类号： H03D1/00 , H03D1/04
摘要： PURPOSE:To provide the impulse noise elimination device eliminating impulse noise with simple configuration. CONSTITUTION:The device is provided with an A/D converter 1 converting an AM signal into a digital signal, a 1st orthogonal output frequency conversion means 2A applying frequency conversion to an output of the A/D converter 1 and outputting two orthogonal signals I, Q, a 1st filter 3A passing either of upper/lower side bands included in the signals I, Q, a 2nd orthogonal output frequency conversion means 2B applying frequency conversion to an output of the 1st filter 3A and outputting four orthogonal signals II, IQ, QI, QQ, a 2nd filter 3B passing any of upper/lower side bands included in the signals II, IQ, Qi, QQ, an AM detection means 4 AM-detecting an output signal of the 2nd filter 3B, a subtractor circuit 5 subtracting AM detection outputs with each other, and an interpolation circuit 6 receiving the output of the subtractor circuit 5 to interpolate an impulse noise invasion period of the AM signal.

86. 发明专利

JPS6410704A HIGH FREQUENCY DETECTING CIRCUIT 失效
公开(公告)号：JPS6410704A
公开(公告)日：1989-01-13
申请号：JP16634387
申请日：1987-07-02
申请人： NEC CORP
发明人： TAMURA YOSHIHARU
IPC分类号： C02F3/06 , B01F3/04 , B01F7/00 , C02F3/00 , H03D1/04 , H03D1/10
摘要： PURPOSE:To obtain a good temperature characteristic even at the time of a small signal by biasing previously a first diode so that the currents of the two diodes come equal, when a high frequency signal is the small signal. CONSTITUTION:An operational amplifier A1 and resistors R1, R2 make a constant voltage power source, which outputs a voltage V1 at a low output impedance, and the operational amplifier A2 makes a buffer circuit, which outputs the voltage (V1+VX1) of the anode of the diode X1 at the low output impedance. When the high frequency signal Vi is a small signal, the values of the voltage V1 and the resistor R3 are set so that the current of the diode X2 comes equal to the current of the diode X1, (as the result, a voltage drop VX2 comes equal to the voltage drop VX1 as well), and furthermore, detection sensitivity comes higher. Thus, if the high frequency signal Vi is the small signal, the voltage drops VX1, VX2 come equal to each other, including the temperature characteristic, and the variation of a detected voltage V0, caused by a temperature change, is removed, and the temperature characteristic comes to be good even at the time of the small signal.

87. 发明专利

JPS6017170B2 失效
公开(公告)号：JPS6017170B2
公开(公告)日：1985-05-01
申请号：JP10088477
申请日：1977-08-23
申请人： NIPPON JIDOSHA BUHIN SOGO KENKYUSHO KK
发明人： EGAMI TSUNEYUKI , KAWAI HISASHI
IPC分类号： H03K9/02 , G01R19/18 , H03D1/04 , H03D1/10 , H03F3/38

88. 实用新型

JPS5719608U 失效
公开(公告)号：JPS5719608U
公开(公告)日：1982-02-01
申请号：JP9598780
申请日：1980-07-08
IPC分类号： H03D1/04 , H03D1/06 , H03D7/12 , H04B1/26 , H04N5/44 , H04N5/48

89. 发明专利

JPS5644601B1 失效
公开(公告)号：JPS5644601B1
公开(公告)日：1981-10-21
申请号：JP3788871
申请日：1971-06-02
IPC分类号： H03D1/04 , H03K17/74 , H04S1/00

90. 发明专利

JPS5614704A AM DEMODULATING CIRCUIT 失效
公开(公告)号：JPS5614704A
公开(公告)日：1981-02-13
申请号：JP9122779
申请日：1979-07-17
申请人： MITSUBISHI ELECTRIC CORP
发明人： MITSUI HIDEO
IPC分类号： H04B1/30 , H03D1/04
摘要： PURPOSE:To eliminate an asymmetric disturbing component by canceling by making use of the property of a symmetric side band characteristic to both side-band amplitude modulation system. CONSTITUTION:The output of intermediate-frequency amplifying circuit 1 is supplied to the 1st synchronous detecting circuit 5 and the 2nd synchronous detecting circuit 6. Carrier extracting circuit 2 extracts a carrier from the output of circuit 1 and then supplies it to +pi/2 phase shifter 3 and -pi/2 phase shifter 4. A signal from phase shifter 3 is supplied to detecting circuit 6. As a result, A+pi/4-phase- shifted signal appears at the output of detecting circuit 5, and a -pi/4-phase-shifted signal at the output of detecting circuit 5, and that from phase shifter 4 to detecting circuit 6. The outputs of detecting circuits 5 and 6 are supplied to -pi/4 phase shifter 7 and +pi/4 phase shifter 8 respectively. The outputs of phase shifters 7 and 8 are both input to adding circuit 9. Adding circuit 9 obtains the sum of the outputs of phase shifters 7 and 8 and outputs an aural frequency signal.

你已经成功收藏专利！

检索式保存成功!

IPRDB

热门服务

关于我们

友情链接

联系方式