Abstract: According to this invention, mechanical noise from a noise source of a pre-identified device can be removed, while tracing a change in gain of acoustic wave data, and noise is removed by tracing a change over time of the noise source. To this end, the gain of a signal from a microphone is automatically adjusted by an Auto level control unit (ALC). A threshold according to the gain of the ALC is stored in a register. A comparator compares audio data from the ALC with the threshold, generates weighting coefficients k and 1?k based on the comparison result, and outputs them to weighting coefficient multipliers. The weighting coefficient multipliers and an adder calculate a weighted average value of data in a memory that stores weighting coefficients of old frames and the input acoustic wave data, and update the contents of the memory by the calculation result. With this update processing, the memory stores only a NOISE component.

Abstract: According to this invention, if noise generated by operation of a component such as a rotary drum of a recording/playback apparatus which operates periodically enters a microphone, noise waveforms can be extracted and reduced. Data obtained from microphones (6, 7) are converted into digital data by A/D converters (11, 12) and are supplied to a control microcomputer (5) and adders (15, 16). The control microcomputer (5) has a memory which stores input data for respective mechanical noise generation cycles. The microcomputer (5) calculates the average of inphase data in each cycle, thereby generating only data of noise components and storing the result in memories (13, 14). The adders (15, 16) output data without noise components by subtracting the inphase data stored in the memories (13, 14) from input current data.

Abstract: An impulse line-clogging detecting apparatus. The apparatus is provide with: a differential pressure detecting unit that detects a differential pressure of a fluid, and outputs time-series data of the differential pressure. Fluctuations are determined by a differential pressure fluctuation calculating unit that calculates a differential pressure fluctuation, and a fluctuation variance calculating unit that calculates a variance of the differential pressure fluctuation. Based upon the calculated variance, a variance ratio calculating unit calculates a variance ratio of the differential pressure fluctuation variance to a differential pressure fluctuation variance obtained in advance in a normal state of the high and low pressure side impulse lines. A variance ratio correcting unit calculates a correction value for suppressing a change of the variance ratio.

Abstract: According to this invention, if noise generated by operation of a component such as a rotary drum of a recording/playback apparatus which operates periodically enters a microphone, noise waveforms can be extracted and reduced. Data obtained from microphones (6, 7) are converted into digital data by A/D converters (11, 12) and are supplied to a control microcomputer (5) and adders (15, 16). The control microcomputer (5) has a memory which stores input data for respective mechanical noise generation cycles. The microcomputer (5) calculates the average of inphase data in each cycle, thereby generating only data of noise components and storing the result in memories (13, 14). The adders (15, 16) output data without noise components by subtracting the inphase data stored in the memories (13, 14) from input current data.

Abstract: According to this invention, if noise generated by operation of a component such as a rotary drum of a recording/playback apparatus which operates periodically enters a microphone, noise waveforms can be extracted and reduced. Data obtained from microphones (6, 7) are converted into digital data by A/D converters (11, 12) and are supplied to a control microcomputer (5) and adders (15, 16). The control microcomputer (5) has a memory which stores input data for respective mechanical noise generation cycles. The microcomputer (5) calculates the average of inphase data in each cycle, thereby generating only data of noise components and storing the result in memories (13, 14). The adders (15, 16) output data without noise components by subtracting the inphase data stored in the memories (13, 14) from input current data.

Abstract: This impulse line-clogging detecting apparatus is provide with: a differential pressure detecting unit that detects a differential pressure of a fluid, and outputs time series data of the differential pressure; a differential pressure fluctuation calculating unit that calculates a differential pressure fluctuation; a fluctuation variance calculating unit that calculates a variance of the differential pressure fluctuation; a variance ratio calculating unit that calculates a variance ratio of the differential pressure fluctuation variance calculated by the fluctuation variance calculating unit to a differential pressure fluctuation variance obtained in advance in a normal state of the high and low pressure side impulse lines; a variance ratio correcting unit that calculates a correction value for suppressing change of the variance ratio; and a clogging determining unit that determines whether the high and low pressure side impulse lines are clogged, based on the variance ratio corrected by the variance ratio co

Abstract: A detecting apparatus includes the following units. A pressure detecting unit detects in time series higher and lower static pressures and a differential pressure. Fluctuation calculating units calculate time series data sets of a differential pressure fluctuation, a higher static pressure fluctuation, and a lower static pressure fluctuation. Square sum calculating units calculate the square sum of the time series data sets of the differential pressure fluctuation, the square sum of the time series data sets of the higher static pressure fluctuation, and the square sum of the time series data sets of the lower static pressure fluctuation. A correlation coefficient calculating unit calculates first and second correlation coefficients. An intermediate variable calculating unit calculates an intermediate variable. A blockage rate calculating unit calculates a blockage rate. A determination unit determines a blockage of higher and lower pressure impulse lines with reference to the blockage rate.

Abstract: A detecting apparatus includes the following units. A pressure detecting unit detects in time series higher and lower static pressures and a differential pressure. Fluctuation calculating units calculate time series data sets of a differential pressure fluctuation, a higher static pressure fluctuation, and a lower static pressure fluctuation. Square sum calculating units calculate the square sum of the time series data sets of the differential pressure fluctuation, the square sum of the time series data sets of the higher static pressure fluctuation, and the square sum of the time series data sets of the lower static pressure fluctuation. A correlation coefficient calculating unit calculates first and second correlation coefficients. An intermediate variable calculating unit calculates an intermediate variable. A blockage rate calculating unit calculates a blockage rate. A determination unit determines a blockage of higher and lower pressure impulse lines with reference to the blockage rate.

Abstract: A pressure detector for detecting a high side pressure from a high pressure side impulse line and a low side pressure from a low pressure side impulse line includes a high side pressure variance calculating section for calculating a high side pressure variance from a high side pressure fluctuation calculated from a high side pressure signal, a low side pressure variance calculating section for calculating a low side pressure variance from a low side pressure fluctuation calculated from a low side pressure signal, a rate calculating section for calculating a variable according to a ratio of the high side pressure variance to the low side pressure variance, and a determining section for determining blockage of the high pressure side impulse line or blockage of the low pressure side impulse line based on a value of the variable.

Abstract: A pressure detector for detecting a high side pressure from a high pressure side impulse line and a low side pressure from a low pressure side impulse line includes a high side pressure variance calculating section for calculating a high side pressure variance from a high side pressure fluctuation calculated from a high side pressure signal, a low side pressure variance calculating section for calculating a low side pressure variance from a low side pressure fluctuation calculated from a low side pressure signal, a rate calculating section for calculating a variable according to a ratio of the high side pressure variance to the low side pressure variance, and a determining section for determining blockage of the high pressure side impulse line or blockage of the low pressure side impulse line based on a value of the variable.

Abstract: According to this invention, mechanical noise from a noise source of a pre-identified device can be removed, while tracing a change in gain of acoustic wave data, and noise is removed by tracing a change over time of the noise source. To this end, the gain of a signal from a microphone is automatically adjusted by an Auto level control unit (ALC). A threshold according to the gain of the ALC is stored in a register. A comparator compares audio data from the ALC with the threshold, generates weighting coefficients k and 1?k based on the comparison result, and outputs them to weighting coefficient multipliers. The weighting coefficient multipliers and an adder calculate a weighted average value of data in a memory that stores weighting coefficients of old frames and the input acoustic wave data, and update the contents of the memory by the calculation result. With this update processing, the memory stores only a NOISE component.

Abstract: A recording apparatus having a microphone unit; and a drive unit adapted to drive a disk medium on which sound collected by the microphone unit is to be recorded. The recording apparatus is capable of changing a rotational speed of the drive unit in accordance with a level of the sound collected by the microphone unit.

Abstract: According to this invention, if noise generated by operation of a component such as a rotary drum of a recording/playback apparatus which operates periodically enters a microphone, noise waveforms can be extracted and reduced. Data obtained from microphones (6, 7) are converted into digital data by A/D converters (11, 12) and are supplied to a control microcomputer (5) and adders (15, 16). The control microcomputer (5) has a memory which stores input data for respective mechanical noise generation cycles. The microcomputer (5) calculates the average of inphase data in each cycle, thereby generating only data of noise components and storing the result in memories (13, 14). The adders (15, 16) output data without noise components by subtracting the inphase data stored in the memories (13, 14) from input current data.

Abstract: Disclosed is a recording apparatus comprising: an audio level detecting unit, for detecting an audio level L indicating the level of sounds collected by a microphone unit and for notifying a control unit of the detected audio level L; and a control unit for changing the rotational speed of a spindle motor in accordance with the audio level L. With this configuration, noise generated during recording can be reduced and the high-quality recording of sounds can be performed.

Abstract: A reproducing apparatus for reproducing an information signal recorded on a recording medium is provided with a reproducing part arranged to reproduce the information signal recorded on the recording medium and to output the reproduced information signal, a muting circuit for muting the information signal outputted from the reproducing part, a detecting circuit for detecting the level of a noise component included in the information signal outputted from the reproducing part, and a control part for controlling a muting action of the muting circuit on the basis of a result of detection provided by the detecting circuit. These parts in combination enable the reproducing apparatus to reproduce the information signal without generating any noise component, in a minimal length of time after the commencement of reproduction.

Abstract: A reproducing apparatus for reproducing a video signal and date-and-time information related to the video signal is arranged to detect a change in date on the basis of the date-and-time information reproduced, to display the data-and-time information for a predetermined period of time according to the change in date, and to inhibit the data-and-time information from being displayed after the lapse of the predetermined period of time.

Abstract: A reproducing apparatus for reproducing an information signal recorded on a recording medium is provided with a reproducing part arranged to reproduce the information signal recorded on the recording medium and to output the reproduced information signal, a muting circuit for muting the information signal outputted from the reproducing part, a detecting circuit for detecting the level of a noise component included in the information signal outputted from the reproducing part, and a control part for controlling a muting action of the muting circuit on the basis of a result of detection provided by the detecting circuit. These parts in combination enable the reproducing apparatus to reproduce the information signal without generating any noise component, in a minimal length of time after the commencement of reproduction.

Abstract: An audio processing apparatus is arranged to be capable of attenuating only an unnecessary wind noise without cutting off the low frequency part of sounds picked up. In the apparatus, a first low frequency band signal and a first high frequency band signal are extracted from a signal obtained by subtracting a delayed right-side audio signal from a received left-side audio signal. A second low frequency band signal and a second high frequency band signal are extracted from a signal obtained by subtracting a delayed left-side audio signal from a received right-side audio signal. An addition signal is formed by adding together the extracted first low frequency band signal and the extracted second low frequency band signal. The extracted first low frequency band signal and the addition signal are added together in an arbitrary variable addition ratio to obtain a first variable addition signal.

Abstract: In an audio signal output device, when muting audio signals outputted from audio signal output terminals, a ground terminal provided for the audio signal output terminals is brought into an open state in association with the muting action, so that the audio signals can be adequately muted without causing any noise or the like.

Abstract: A rotation control device including a rotary head drum drive circuit for driving rotation of a rotary head drum, a tape transport mechanism for transporting a tape in a predetermined direction relative to the rotary head drum, and a correction circuit for detecting a change of the speed of transportation of the tape to supply correction information to the rotary head drum drive circuit so that the driving state of the rotary head drum is corrected.