公开(公告)号：JP2005341257A

公开(公告)日：2005-12-08

申请号：JP2004157746

申请日：2004-05-27

Applicant: Yamaha Corp ,  ヤマハ株式会社

Inventor： NORO MASAO

IPC: H04S3/00 ,  H03G5/00 ,  H04B1/04 ,  H04R5/04 ,  H04S7/00

CPC classification number: H04R5/04

Abstract: PROBLEM TO BE SOLVED: To provide an audio amplifier (AV amplifier) which can transmit three channels including a sub-woofer channel, using a general-purpose, inexpensive two-channel transmission module. SOLUTION: An audio signal of the sub-woofer channel is combined to surround left and right channels by using adders 15L, 15R. The signal of the surround channel is cut of the bass by high-pass filters 13L, 13R. Generally, since a surround speaker has a small diameter and a small size, the surround speaker does not have pronunced properties in a low-pitched sound zone in many cases. If the low-pitched sound is pronounced from the sub-woofer, even when the low-pitched sound is not pronounced from the surround speaker, since a listener can hardly detect, such a combining can be made. COPYRIGHT: (C)2006,JPO&NCIPI

Abstract translation: 要解决的问题：提供一种音频放大器（AV放大器），其可以使用通用廉价的双通道传输模块来传输包括次低音扬声器通道的三个通道。 解决方案：通过使用加法器15L，15R将次低音扬声器通道的音频信号组合以包围左右声道。 环绕通道的信号是通过高通滤波器13L，13R切断低音。 通常，由于环绕扬声器具有小直径和小尺寸，所以在许多情况下，环绕声扬声器在低音区域中没有发音特性。 如果从低音扬声器发出低音的声音，即使当低音的声音没有从环绕扬声器发出时，由于听众几乎不能检测到，所以可以进行这种组合。 版权所有（C）2006，JPO＆NCIPI

公开(公告)号：JP2004336530A

公开(公告)日：2004-11-25

申请号：JP2003131538

申请日：2003-05-09

Applicant: Yamaha Corp ,  ヤマハ株式会社

Inventor： USUI AKIRA ,  NORO MASAO

IPC: H04R1/40 ,  H04R3/12 ,  H04S3/00

CPC classification number: H04R3/12 ,  H04R2203/12 ,  H04R2205/022 ,  H04S3/00

Abstract: PROBLEM TO BE SOLVED: To radiate efficiently a sound while preventing sound radiation characteristics from being beam-shaped and comb-shaped.
SOLUTION: To each of speaker units 1-1 to 1-15 constituting an array speaker system, signals are inputted to each of which weight is added that is effected by absolute values of weighting factors C1 to C15 that are based on a Bessel function, in weighting means 2-1 to 2-15 that are provided corresponding to the speaker units, respectively. Among the weighting means 2-1 to 2-15, to the weighting means whose weighting factor Ci takes on a negative value, the signals are supplied that have passed through an all pass filter 3 by which a phase in a high frequency region turns at an angle of 180°. Consequently, the radiation characteristics of the signals in a high frequency region can be prevented from being beam-shaped and comb-shaped as well as being able to prevent the radiation efficiency of the signals in a low frequency region from being lowered due to outputs of reverse phase signals.
COPYRIGHT: (C)2005,JPO&NCIPI

Abstract translation: 要解决的问题：有效地发出声音，同时防止声辐射特性为波束形状和梳状。 解决方案：对构成阵列扬声器系统的扬声器单元1-1至1-15中的每个扬声器单元，将信号输入到加权因子C1至C15的绝对值所基于的 贝塞尔函数，分别对应于扬声器单元提供的加权装置2-1至2-15。 在加权装置2-1至2-15中，对于加权因子Ci取负值的加权装置，提供已经通过全频段滤波器3的信号，通过该全通滤波器3，高频区域中的相位转为 角度为180°。 因此，可以防止高频区域中的信号的辐射特性是波束形状和梳状形状，并且能够防止低频区域中的信号的辐射效率由于 反相信号。 版权所有（C）2005，JPO＆NCIPI

公开(公告)号：JP2004007324A

公开(公告)日：2004-01-08

申请号：JP2002181772

申请日：2002-06-21

Applicant: YAMAHA CORP

Inventor： TSUJI NOBUAKI ,  NORO MASAO

IPC: H03K4/06 ,  H03F3/217

Abstract: PROBLEM TO BE SOLVED: To provide a triangular wave generating circuit of class D amplifier capable of generating a triangular wave with high accuracy without variations in the peak value and offset deviations. SOLUTION: An integration circuit comprises an operational amplifier 39 and a capacitor 40. Then, switch elements 36, 37 are alternately turned on, The capacitor 40 is charged by a current from constant current circuits 34, 35 alternately and a triangular wave is obtained at an output terminal 46. When the voltage at the output terminal 46 reaches +1V or -1v at this time, comparator circuits 41, 42 and flip-flop circuits comprising NAND gates 44, 45 change over the switch elements 36, 37. The current of the constant current circuits 34, 35 is controlled in response to the current of a load circuit 33, and the current of the load circuit 33 is controlled by a PLL circuit including a phase comparator circuit 22, a loop filter 23, an LPF 24, an operational amplifier 30, and an FET 32. Thus, the frequency of the output triangular wave is the same as the frequency of a clock pulse CK. COPYRIGHT: (C)2004,JPO

公开(公告)号：JP2003204590A

公开(公告)日：2003-07-18

申请号：JP2002001276

申请日：2002-01-08

Applicant: YAMAHA CORP

Inventor： MITSUOKA KUNIHIKO ,  NORO MASAO

IPC: H04R3/00 ,  H03F1/30 ,  H03F3/217 ,  H03G3/34

Abstract: PROBLEM TO BE SOLVED: To provide a class D amplifier capable of effectively reducing a wait time until a mute state is released and effectively suppressing occurrence of pop noise or the like without the need for employing a large-sized expensive component such as a relay. SOLUTION: An operational amplifier OPA receives an external music signal VIN at its inverting input terminal, receives a reference voltage VREF at its noninverting input terminal and outputs a signal INA whose amplitude center is the reference voltage. A modulation circuit MOD applies PWM modulation to the signal INA to convert it into a pulse signal, which is given to a drive circuit DRV for driving a loudspeaker SPK. At application of power, after a voltage setting circuit VSET temporarily sets a voltage at a node Q at which the reference voltage VREF appears to a prescribed voltage, the circuit VSET restores the voltage at the node Q to the reference voltage VREF. When the voltage at the node Q and the voltage INA are nearly equal to each other in this process, a mute state control circuit MCTL releases the mute state. COPYRIGHT: (C)2003,JPO

公开(公告)号：JP2002252393A

公开(公告)日：2002-09-06

申请号：JP2001046486

申请日：2001-02-22

Applicant: YAMAHA CORP

Inventor： SATO HIDEKI ,  NORO MASAO

IPC: G01R33/09 ,  G11B5/39 ,  H01L43/08

Abstract: PROBLEM TO BE SOLVED: To provide a magnetic sensor that can detect a magnetic field with high accuracy, even when the characteristics of a magnetic tunnel effect element change due to a temperature change or a change in the lapse of time. SOLUTION: The magnetic tunnel effect element 10 used in this magnetic sensor has a sensing layer 11 formed into a laminate composed of a PtMn antiferromagnetic film 11a and an NiFe ferromagnetic film 11b, a thin Al-O insulating layer 12, and an NiFe reference layer 13. These layers 11, 12, and 13 constitute a magnetic tunnel junction structure. The ferromagnetic film 11a, insulating layer 12, and ferromagnetic film 13 have rectangular shapes, and the magnetization of the ferromagnetic film 11a is weakly pinned in the direction of its shorter edges. Consequently, the resistance of the element 10 changes functionally even with respect to the magnetic field that changes in the direction of the longer edges. By imparting an AC bias magnetic field in the direction of the longer edges, an applied magnetic field h is detected based on the occurring resistance change of the element 10.

公开(公告)号：JP2001160721A

公开(公告)日：2001-06-12

申请号：JP34261299

申请日：1999-12-01

Applicant: YAMAHA CORP

Inventor： NORO MASAO

IPC: H03F1/32 ,  H03F3/21 ,  H03F3/30

Abstract: PROBLEM TO BE SOLVED: To provide the power amplifier circuit of high bias stability and high linearity capable of low voltage drive. SOLUTION: This circuit is provided with a differential amplifier circuit 10 for amplifying + side input signals, - side input signals and differential voltage signals, an amplifier circuit 12 for amplifying the output signals of the differential amplifier circuit, an output circuit 16 composed of complementarily connected first PMOS transistor and first NMOS transistor and formed by connecting the connection point of the PMOS transistor and the NMOS transistor to a load and a current boosting circuit 14 for supplying a current for which the output signal current of the amplifier circuit is multiplied to a prescribed multiplying power through the output circuit to the load.

公开(公告)号：JPH1098877A

公开(公告)日：1998-04-14

申请号：JP22197697

申请日：1997-08-04

Applicant: YAMAHA CORP

Inventor： NORO MASAO

IPC: H02M3/155 ,  H02M3/28 ,  H02M3/335

Abstract: PROBLEM TO BE SOLVED: To improve efficiency and reduce the operating voltage in a circuit and the harmonic components in an operating current waveform. SOLUTION: Two switching elements S1, S2 are connected in series to a DC power source 1 to drive the switching elements S1, S2 in push-pull. AC voltage outputted from the node A of both elements S1, S2 is supplied to a load RL through a power supply passage P by being rectified and filtered by diodes D1, D2 and capacitors C3, C4. A series resonance circuit consisting of an inductance L2 and a capacitor C2 is formed in series to the power supply passage P. A resonance circuit consisting of an inductance L1 and a capacitor C1 is formed in parallel to the power supply passage P. After the switching elements S1, S2 are turned on so that series resonance by the series resonance circuit is completed, the element is turned off. After one element S1 (S2) is turned off so that voltage applied to the other element S2 (S1) by parallel resonance with a parallel resonance circuit becomes almost zero, the other element S2 (S1) is turned on.

公开(公告)号：JP2513381B2

公开(公告)日：1996-07-03

申请号：JP27196391

申请日：1991-09-24

Applicant: YAMAHA CORP

Inventor： NORO MASAO

IPC: H02M3/155 ,  H02M3/28 ,  H02M3/338

公开(公告)号：JPH07273567A

公开(公告)日：1995-10-20

申请号：JP8540094

申请日：1994-03-31

Applicant: YAMAHA CORP

Inventor： NORO MASAO

IPC: H03F3/45 ,  H03F3/26

Abstract: PURPOSE:To simplify the configuration of a common mode feedback circuit in the differential input/differential output operational amplifier circuit. CONSTITUTION:An input signal is received from input terminals IN-A, IN-B and amplified by a differential amplifier stage 12. An output signal of the differential amplifier stage 12 is amplified by an output amplifier stage 14 and output signals Voa, Vob are obtained from output terminals OUT-A, OUT-B. A common mode voltage component detection circuit 16 detects a common mode voltage component Vc of the output signals Voa, Vob. A common mode feedback circuit 18 amplifies a voltage difference between the common mode voltage component Vc and a reference voltage Vref by using TRs Q3, Q4 and a current corresponding to the voltage difference flows to the TR Q7. The current flows to TRs Q5, Q6 being components of a current mirror circuit and to the TR Q7 to control an output amplifier stage 14. Thus, the common mode voltage Vc of the differential output of the output amplifier stage 14 is fed back to make a common mode voltage Vc being a differential output stable.

公开(公告)号：JPH07244996A

公开(公告)日：1995-09-19

申请号：JP6203194

申请日：1994-03-07

Applicant: YAMAHA CORP

Inventor： NORO MASAO

IPC: G11C27/02

Abstract: PURPOSE:To eliminate variations of input impedances in accordance with gain switchings in a ground flow type gain switching sample-hold circuit. CONSTITUTION:Resistors R1 to R4 are set so as to be R1 (R1+R)R1-]divided by [(R1+R2+R)(R2-R1)R]. When this circuit is made to be operated as the sample-hold circuit of a gain R/R1 by turning a switch SW1 on and off, switches SW2, SW3 are made to be fixed to offs. When the circuit is made to be operated as the sample-hole circuit of a gain R/R2 by turning the switch 2 on and off, the switch SW1 is made to be fixed to the off and the switch SW3 is made to be fixed to the on. Since the resistor R5 is existing, the variations of input impedances in accordance with gain switchings are eliminated.