公开(公告)号：US20060140414A1

公开(公告)日：2006-06-29

申请号：US10537981

申请日：2003-12-09

Applicant: Daisuke Higashihara ,  Shokichiro Hino ,  Koichi Tsuchiya ,  Tomohiko Endo

Inventor： Daisuke Higashihara ,  Shokichiro Hino ,  Koichi Tsuchiya ,  Tomohiko Endo

IPC: H04R29/00 ,  H04R3/00

CPC classification number: H04R29/00

Abstract: A device 1 for measuring a propagation time of a sound wave comprises a sound source means 11 and a calculation means 12. The sound source means 11 outputs a time stretched pulse as a sound source signal input to a speaker 3. The calculation means 12 calculates a cross-correlation function of the time stretched pulse and the sound signal which is output from the speaker 3 and is received in a microphone 4. Based on the cross-correlation function, the propagation time of the sound wave between the speaker 3 and the microphone 4 is found.

Abstract translation: 用于测量声波的传播时间的装置1包括声源装置11和计算装置12。 声源装置11输出延时脉冲作为输入到扬声器3的声源信号。 计算装置12计算延时脉冲和从扬声器3输出并被接收在麦克风4中的声音信号的互相关函数。 基于互相关函数，发现扬声器3和麦克风4之间的声波的传播时间。

公开(公告)号：US20060137454A1

公开(公告)日：2006-06-29

申请号：US10537984

申请日：2003-12-09

Applicant: Daisuke Higashihara

Inventor： Daisuke Higashihara

IPC: G01N9/24 ,  G01N29/04

CPC classification number: H04R3/02 ,  G01H13/00 ,  H04R3/002

Abstract: A device 20 for detecting a resonant frequency comprises a sound source means 21, a signal synthesization switching means 26 and 27, and a measuring means 25. The signal synthesization switching means 26 and 27 are capable of switching between a first state in which the signal synthesization switching means 26 and 27 outputs a measurement signal and a second state in which the signal synthesization switching means 26 and 27 outputs a synthesized signal containing the measurement signal and the signal output from a microphone 14. The device 20 detects the resonant frequency based on comparison between the first amplitude frequency characteristic measured in the first state and the second amplitude frequency characteristic measured in the second state.

Abstract translation: 用于检测谐振频率的装置20包括声源装置21，信号合成切换装置26和27以及测量装置25。 信号合成切换装置26和27能够在信号合成切换装置26和27输出测量信号的第一状态和信号合成切换装置26和27输出包含 测量信号和从麦克风14输出的信号。 装置20基于在第一状态下测量的第一幅度频率特性与在第二状态下测量的第二振幅频率特性之间的比较来检测谐振频率。

公开(公告)号：US07035395B2

公开(公告)日：2006-04-25

申请号：US10182523

申请日：2001-01-30

Applicant: Kazuaki Maeda

Inventor： Kazuaki Maeda

IPC: H04M1/00

CPC classification number: H04B1/64 ,  H03G3/001 ,  H03G3/3042

Abstract: The present invention provides a digital communication system which is free from noise generated in a receiver. A transmitter converts an analog input signal to a digital signal, and then a power level detector 5 compares the digital signal with a predetermined level. In accordance with the result, the transmitter transmits a transmission signal which includes the digital signal or a digital signal amplified from that digital signal, and a control bit indicative of the result of comparison. The receiver, in accordance with the control bit included in the received digital signal, outputs an analog signal converted from the received digital signal or an analog signal converted from the received digital signal after it is digitally amplified.

公开(公告)号：US5148491A

公开(公告)日：1992-09-15

申请号：US575243

申请日：1990-08-30

Applicant: Sinji Sakamoto ,  Kenichi Furukawa

Inventor： Sinji Sakamoto ,  Kenichi Furukawa

IPC: H03G3/20 ,  H04R3/00 ,  H04R27/00

CPC classification number: H03G3/301 ,  H04R27/00 ,  H04R3/005

Abstract: An automatic mixer apparatus is described which comprises a plurality of channels each including a level detecting circuit, a comparator and a voltage control amplifier, a gain control circuit for controlling the gains of the voltage control amplifiers of the respective channels and a mixer circuit for mixing signals from the voltage control amplifiers. The level detecting circuit detects a level of an aural signal received at the corresponding channel and the comparator operates to compare the detected level from the detecting circuit and a reference level. When the detected level is higher than the reference level, the comparator outputs a comparison signal to the corresponding voltage control amplifier to turn on. The gain control circuit receives the comparison signals from the whole comparators and outputs a gain control signal to the respective voltage amplifiers whereby the gains thereof are controlled in accordance with the number of the comparison signals received at the gain control circuit.

Abstract translation: 描述了一种自动混合装置，其包括多个通道，每个通道包括电平检测电路，比较器和电压控制放大器，用于控制各个通道的电压控制放大器的增益的增益控制电路和用于混合的混频器电路 来自电压控制放大器的信号。 电平检测电路检测在相应通道处接收到的听觉信号的电平，并且比较器操作以将来自检测电路的检测电平与参考电平进行比较。 当检测到的电平高于参考电平时，比较器将比较信号输出到相应的电压控制放大器以导通。 增益控制电路接收来自整个比较器的比较信号，并将增益控制信号输出到各个电压放大器，由此根据在增益控制电路处接收的比较信号的数量来控制其增益。