Abstract: The present invention provides a method for detecting a shape of a butt joint of a welded steel pipe. A specific detection range including a butt joint of a welded steel pipe is scanned with a non-contact means to obtain geometric coordinate data. Coordinates of a start point and an end point of the specific detection range, a first selected point located between the start point and the butt joint, and a second selected point located between the butt joint and the end point are selected from the geometric coordinate data. A first approximate circle including the start point, the end point, and the first selected point, and a second approximate circle including the start point, the end point, and the second selected point are calculated. A deviation between the first and the second approximate circles is used as an index representing the shape of the butt joint.

Abstract: The present invention provides a method for detecting a shape of a butt joint of a welded steel pipe. A specific detection range including a butt joint of a welded steel pipe is scanned with a non-contact means to obtain geometric coordinate data. Coordinates of a start point and an end point of the specific detection range, a first selected point located between the start point and the butt joint, and a second selected point located between the butt joint and the end point are selected from the geometric coordinate data. A first approximate circle including the start point, the end point, and the first selected point, and a second approximate circle including the start point, the end point, and the second selected point are calculated. A deviation between the first and the second approximate circles is used as an index representing the shape of the butt joint.

Abstract: A reproducing apparatus includes: a digital signal processing block configured to execute first boost processing for setting a volume level for an entered digital audio signal and boosting an amplitude level of the signal; a digital-to-analog conversion block configured to convert the digital audio signal into an analog one; an analog signal processing block configured to execute second boost processing for boosting an amplitude level of the analog audio signal; an analog volume adjusting block configured to set a volume level for the analog audio signal from the analog signal processing block; a loudspeaker configured to output the analog audio signal from the analog volume adjusting block; an operating block configured to indicate a volume level of an audio signal from the loudspeaker and turn on/off the boost processing for the audio signals; and a control block configured to control components in accordance with an operation by the operating block.

Abstract: Disclosed herein is a noise canceling apparatus including: a microphone configured to pick up ambient sound as noise; a first signal generator configured to receive a signal from the microphone to generate a noise cancel signal that is inverted in phase to the signal received from the microphone and has an amplitude level considered with an attenuation in accordance with a distance from the microphone to an observation point separated away from the microphone; a first loudspeaker configured to be arranged in the proximity of the microphone and output the noise cancel signal; a second signal generator configured to receive the signal from the microphone to generate a positive-phase signal that has the same phase as that of the signal from the microphone; and a second loudspeaker configured to be arranged in the proximity of the microphone and output the positive-phase signal.

Abstract: A data reproduction apparatus includes: arithmetic means for calculating difference data that indicate a difference between left-channel and right-channel data that have been compressed in a predetermined compression format; higher harmonic component generation means for generating a higher harmonic component, which was lost during compression, by performing, when the difference data's signal level exceeds a predetermined threshold, a digital limiter process that suppresses the signal level to the threshold; and adding means for adding the higher harmonic component to the left-channel and right-channel data to reproduce original data before being compressed.

Abstract: The present invention provides a digital signal processing device that considerably reduces a return noise generated in a processing result signal in specific signal processing without wastefully increasing the processing load. There is provided a digital signal processing device that executes specific signal processing under which a return noise is generated in a processing result signal which includes an up-sampling processing unit that performs the up-sampling processing for a digital signal with a predetermined up-sampling rate to generate an up-sampling signal, a specific signal processing unit that performs the specific signal processing for the up-sampling signal generated by the up-sampling processing unit to generate the processing result signal, and a down-sampling processing unit that performs the down-sampling processing for the processing result signal generated by the specific signal processing unit with a predetermined down-sampling rate to generate a down-sampling signal.

Abstract: A sound field in a vehicle can be further readily and optimally corrected without forcing a user to do troublesome work. As an embodiment of the present invention, a measurement sound emitted through a left speaker or a right speaker at a further position in a view from a driver's listening point that was assumed on the head touching surface of the headrest of the driver's seat or the passenger seat is picked up, with a microphone provided as buried on a front panel of a head unit to be attached to the almost center position between the driver's seat and the passenger seat in the vehicle. And the frequency characteristic of the above sound is corrected, based on a tendency that the frequency characteristic of an audio sound reaching from the left speaker or the right speaker to the microphone is almost approximate to the virtual frequency characteristic of an audio sound that will reach from the left speaker or the right speaker to the driver's listening point assumed on the head touching surface.

Abstract: A frequency-characteristic-acquisition device that inputs a time-stretched-pulse signal to a system to be measured and that acquires information about a frequency characteristic of the system on the basis of a signal output from the system is provided. The frequency-characteristic-acquisition device includes a control unit which performs control so that the time-stretched-pulse signal is expanded in a time-axis direction and output to the system, and an acquisition unit that analyzes the signal output from the system and that acquires the frequency-characteristic information.

Abstract: A frequency-characteristic-acquisition device that inputs a time-stretched-pulse signal to a system to be measured and that acquires information about a frequency characteristic of the system on the basis of a signal output from the system is provided. The frequency-characteristic-acquisition device includes a control unit which performs control so that the time-stretched-pulse signal is expanded in a time-axis direction and output to the system, and an acquisition unit that analyzes the signal output from the system and that acquires the frequency-characteristic information.

Abstract: A measuring apparatus that measures sound arrival delay time from a speaker to a microphone on the basis of a result obtained by collecting signals output from the speaker by means of the microphone includes: measuring means for measuring the sound arrival delay time that makes a control such that a first sine wave signal having a first frequency and a second sine wave signal having a second frequency different from the first frequency are output from the speaker, is input with the first sine wave signal and the second sine wave signal collected by the microphone and then mixes the first sine wave signal and the second sine wave signal so as to generate a third sine wave signal having a frequency corresponding to a difference between the first frequency and the second frequency, and measures the sound arrival delay time on the basis of the third sine wave signal.

Abstract: A sound measuring apparatus for measuring a sound-arrival delay time from a speaker to a microphone on the basis of a result obtained by outputting a test signal from the speaker and picking up the test signal using the microphone includes the following elements. A control unit performs control so that the test signal is expanded in a time axis and is then output from the speaker. A delay time measuring unit measures an expansion-based measured delay time on the basis of a delay time that is measured on the basis of a time difference between the test signal expanded in the time axis and output from the speaker and a signal obtained from the microphone by picking up the output expanded test signal, and obtains the sound-arrival delay time as the expansion-based measured delay time.

Abstract: The present invention provides an audio apparatus including: a decoding device configured to decode results of channel-by-channel reproduction of a multichannel sound source made up of at least a left channel, a right channel, and a center channel, and to down-mix the decoded results of channel-by-channel reproduction in accordance with the number of speakers configured in a speaker system without a center speaker corresponding to the center channel; an audio processing device configured to perform predetermined audio processing on the decoded results having undergone the down-mixing by the decoding device, and to get the processed results output from the speaker system; and a control device configured to control the audio processing device.

Abstract: A sound field measurement apparatus includes a signal generating unit for outputting a burst signal, a driving unit for driving a speaker using the burst signal, a microphone for picking up an audio output from the speaker, an analog-digital converter for performing analog-digital conversion processing on an output signal from the microphone and outputting picked-up audio data, a filtering unit for performing filtering processing on the picked-up audio data, and an analyzing unit for determining a propagation time of the audio output from the speaker to the microphone in accordance with data output from the filtering unit. In this sound field measuring apparatus, the filtering unit is an IIR filter configured to filter the picked-up audio data forward and then backward along a time axis, or an IIR filter configured to filter the picked-up audio data backward and then forward along the time axis.

Abstract: A clipping prevention device, includes: a compression section adapted to compress an input digital audio signal level; a digital-analog conversion section adapted to operate at a predetermined first operating voltage and convert the digital audio signal into an analog audio signal; an electronic volume control adapted to operate at a second operating voltage and amplify or attenuate the analog audio signal with a user-changeable amplification factor; and a control section adapted to calculate a clipping level based on the maximum amplification factor of the electronic volume control and the user-changeable amplification factor, the maximum amplification factor being determined when the analog audio signal at the maximum signal level is amplified to the maximum signal level, and also adapted to control the compression section so that the signal is compressed so as to prevent clipping of the analog audio signal amplified or attenuated by the electronic volume control.

Abstract: A reproducing apparatus includes: a digital signal processing block configured to execute first boost processing for setting a volume level for an entered digital audio signal and boosting an amplitude level of the signal; a digital-to-analog conversion block configured to convert the digital audio signal into an analog one; an analog signal processing block configured to execute second boost processing for boosting an amplitude level of the analog audio signal; an analog volume adjusting block configured to set a volume level for the analog audio signal from the analog signal processing block; a loudspeaker configured to output the analog audio signal from the analog volume adjusting block; an operating block configured to indicate a volume level of an audio signal from the loudspeaker and turn on/off the boost processing for the audio signals; and a control block configured to control components in accordance with an operation by the operating block.

Abstract: Disclosed herein is a noise canceling apparatus including: a microphone configured to pick up ambient sound as noise; a first signal generator configured to receive a signal from the microphone to generate a noise cancel signal that is inverted in phase to the signal received from the microphone and has an amplitude level considered with an attenuation in accordance with a distance from the microphone to an observation point separated away from the microphone; a first loudspeaker configured to be arranged in the proximity of the microphone and output the noise cancel signal; a second signal generator configured to receive the signal from the microphone to generate a positive-phase signal that has the same phase as that of the signal from the microphone; and a second loudspeaker configured to be arranged in the proximity of the microphone and output the positive-phase signal.

Abstract: The present invention provides a digital signal processing device that considerably reduces a return noise generated in a processing result signal in specific signal processing without wastefully increasing the processing load. There is provided a digital signal processing device that executes specific signal processing under which a return noise is generated in a processing result signal which includes an up-sampling processing unit that performs the up-sampling processing for a digital signal with a predetermined up-sampling rate to generate an up-sampling signal, a specific signal processing unit that performs the specific signal processing for the up-sampling signal generated by the up-sampling processing unit to generate the processing result signal, and a down-sampling processing unit that performs the down-sampling processing for the processing result signal generated by the specific signal processing unit with a predetermined down-sampling rate to generate a down-sampling signal.

Abstract: A data reproduction apparatus includes: arithmetic means for calculating difference data that indicate a difference between left-channel and right-channel data that have been compressed in a predetermined compression format; higher harmonic component generation means for generating a higher harmonic component, which was lost during compression, by performing, when the difference data's signal level exceeds a predetermined threshold, a digital limiter process that suppresses the signal level to the threshold; and adding means for adding the higher harmonic component to the left-channel and right-channel data to reproduce original data before being compressed.

Abstract: Disclosed herein is an audio output device including: an equalizer configured to execute frequency characteristic correction processing for an audio signal from an audio source; an output part configured to supply an audio signal processed by the equalizer to a speaker for audio output from the speaker; a signal analyzer configured to analyze a frequency characteristic of an input audio signal to thereby obtain a gain of each of sample points on a frequency axis; and an arithmetic unit configured to control parameters of the equalizer, the arithmetic unit extracting sample points having substantially equal intervals on a logarithmic-scale frequency axis from sample points of which gains have been obtained by the signal analyzer, the arithmetic unit calculating parameters of the equalizer by using differences between gains of the extracted sample points and gains at frequencies corresponding to the extracted sample points on a target frequency characteristic.

Abstract: A sound field in a vehicle can be further readily and optimally corrected without forcing a user to do troublesome work. As an embodiment of the present invention, a measurement sound emitted through a left speaker or a right speaker at a further position in a view from a driver's listening point that was assumed on the head touching surface of the headrest of the driver's seat or the passenger seat is picked up, with a microphone provided as buried on a front panel of a head unit to be attached to the almost center position between the driver's seat and the passenger seat in the vehicle. And the frequency characteristic of the above sound is corrected, based on a tendency that the frequency characteristic of an audio sound reaching from the left speaker or the right speaker to the microphone is almost approximate to the virtual frequency characteristic of an audio sound that will reach from the left speaker or the right speaker to the driver's listening point assumed on the head touching surface.