公开(公告)号：US3818355A

公开(公告)日：1974-06-18

申请号：US28680872

申请日：1972-09-06

Applicant: VICTOR COMPANY OF JAPAN

Inventor： ISHIGAKI Y

IPC: G01R23/02 ,  G01R23/09 ,  H03D3/00 ,  H03D3/04 ,  H03K5/00 ,  H04L27/22

CPC classification number: H03D3/04

Abstract: A demodulating system produces two square waves of mutually opposite phase responsive to an angular modulated wave in which a carrier wave of low frequency is modulated. The phase of one square wave is delayed by 90*, thereby to produce two square waves of mutually opposite phase. The four square waves of phases respectively differing by 90* are differentiated for producing a differentiated pulse train of a frequency which is quadruple the frequency of the angular modulated wave. Pulse counting means demodulates this differentiated pulse train.

Abstract translation: 一个解调系统产生两个相反相位的方波，响应于调制低频载波的角度调制波。 一个方波的相位延迟90°，从而产生相互相反的两个方波。 分别相差90°的相位的四个方波被区分用于产生频率的微分脉冲串，其是角调制波的频率的四倍。 脉冲计数装置解调这个不同的脉冲串。

公开(公告)号：US3806667A

公开(公告)日：1974-04-23

申请号：US21330671

申请日：1971-12-29

Applicant: VICTOR COMPANY OF JAPAN

Inventor： ISHIGAKI Y ,  SASAMURA K

IPC: H03G7/06 ,  H04S3/00 ,  G11B3/00 ,  G11B3/74

CPC classification number: H03G7/06 ,  H04S3/006

Abstract: A four channel recording system starts with a pre-recorded magnetic tape which is played back by two reproducing heads. A first head is used to detect the output signal level read from the tape. The output from the other head is then controlled responsive to the detected level. Thereafter, the controlled signal is recorded on a phonograph record at signal levels set responsive to the output of the first head.

Abstract translation: 四通道记录系统从由两个再现头重放的预先记录的磁带开始。 第一个头用于检测从磁带读取的输出信号电平。 然后响应于检测到的电平来控制来自另一头的输出。 此后，受控信号以响应于第一磁头的输出设置的信号电平被记录在留声机记录上。

公开(公告)号：US3795876A

公开(公告)日：1974-03-05

申请号：US3795876D

申请日：1972-04-04

Applicant: VICTOR COMPANY OF JAPAN

Inventor： TAKAHASHI N ,  ITOH Y ,  FUJITA Y ,  NISHIKAWA K ,  ISHIGAKI Y

IPC: H03G9/18 ,  H04B1/64

CPC classification number: H03G9/18

Abstract: A compression and/or expansion system comprises fixed frequency characteristic changing means having a specific fixed frequencyresponse characteristic which increases or decreases the level of an input signal in a predetermined frequency band. A variable frequency characteristic changing means has a characteristic which varies so that it approaches a characteristic complimentary with the characteristic of the fixed frequency characteristic change means as the level of the input signal becomes larger and approaches a flat characteristic as the level of the signal becomes smaller. The signal is effectively compressed or expanded according to its level by passing through the fixed and variable frequency characteristic change means.

Abstract translation: 压缩和/或扩展系统包括具有特定固定频率响应特性的固定频率特性改变装置，其增加或减少预定频带中的输入信号的电平。 可变频率特性改变装置具有随着信号电平变大而接近与固定频率特性改变装置的特性互补的特性的特性，随着信号电平变小而变得平坦特性 。 信号通过穿过固定和可变频率特性改变装置根据其电平被有效地压缩或扩大。