The present invention relates to an ultra-directional speaker system comprising: a first envelope calculation unit for calculating the envelope of the currently input audio input signal; a square root calculation unit for generating a square root signal of a first envelope signal by calculating a square root of the first envelope signal calculated by the first envelope calculation unit; a pre-distortion adaptive filter unit for generating a compensation signal by performing distortion compensation in which an adaptive filter coefficient update term according to an adaptive filter coefficient determined in a previous stage is applied to the currently input audio input signal; a second envelope calculation unit for generating a second envelope signal by calculating the envelope of the compensation signal; an error calculation unit for generating an error signal by comparing and calculating the second envelope signal with the square root signal of the first envelope signal; an adaptive filter coefficient update unit for calculating an adaptive filter coefficient update term and an adaptive filter coefficient from the error signal; a dynamic signal modulation unit for generating a modulation signal by dynamically modulating the compensation signal into an ultrasonic band; an ultrasonic transducer model for modeling an inverse filter corresponding to frequency characteristics of an ultrasonic transducer, and generating a filtering signal by applying the inverse filter to the modulation signal; an ultrasonic amplifier for amplifying the filtering signal; and the ultrasonic transducer for converting the amplified signal into an ultrasonic signal, wherein the dynamic signal modulation unit includes: an AM signal modulation unit for generating an AM modulation signal of transmission data; a first sideband signal modulation unit, which receives the AM modulation signal and performs a Hilbert operation thereon so as to obtain a first sideband modulation signal from which a carrier wave has been removed; and a second sideband signal unit, which receives the first sideband modulation signal and adds the carrier wave thereto so as to obtain a second sideband modulation signal.
H04R 1/32 - Arrangements for obtaining desired frequency or directional characteristics for obtaining desired directional characteristic only
H04R 1/40 - Arrangements for obtaining desired frequency or directional characteristics for obtaining desired directional characteristic only by combining a number of identical transducers
H04R 3/04 - Circuits for transducers for correcting frequency response
2.
ULTRASONIC SENSOR ELEMENT HAVING IMPROVED PERFORMANCE
The present invention provides an ultrasonic sensor element having improved performance, the ultrasonic sensor element comprising a piezoelectric ceramic and a diaphragm disposed on the piezoelectric ceramic, wherein the diaphragm has a nano-pattern formed on the surface thereof, the nano-pattern having a predetermined shape which has certain depth and area.
B06B 1/06 - Processes or apparatus for generating mechanical vibrations of infrasonic, sonic or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction
The present invention relates to an improved ultrasound super-directional speaker system and a frequency modulation processing method therefor. Disclosed are an improved ultrasound super-directional speaker system and a frequency modulation processing method therefor, the improved ultrasound super-directional speaker system comprising: a processor including a general speaker function and software for performing ultrasound signal modulation generation; and an amplifier including a middle device, which receives a signal modulated by the processor so as to be capable of recreating the received signal in real time. According to the present invention, provided are: an improved ultrasound super-directional speaker system, which is less expensive and smaller than a conventional amplifier so as to have lower production costs and provide a variety of applications, is configured and processed in a frequency band that is more intuitive and facilitates access, and can implement an algorithm for improving processing speed through gain unification; and a frequency modulation processing method therefor.
The present invention relates to an ultra-directional speaker circuit with enhanced stability. The disclosed ultra-directional speaker circuit with enhanced stability comprises: a first inductor and a third inductor connected to a positive polarity electric signal line for a speaker input; a second inductor and a fourth inductor connected to a negative polarity electric signal line for a speaker input; and a first speaker, a second speaker, a third speaker, and a fourth speaker which receive the speaker input so as to convert same into vibration that can be recognized as sound by a human, wherein: an audio signal having passed through the first inductor is inputted to each of positive polarity terminals of the first speaker and the second speaker, and an audio signal having passed through the second inductor is connected to negative polarity terminals of the first speaker and the second speaker; and an audio signal having passed through the third inductor is inputted to each of positive polarity terminals of the third speaker and the fourth speaker, and an audio signal having passed through the fourth inductor is connected to negative polarity terminals of the third speaker and the fourth speaker. According to the present invention, provided is an ultra-directional speaker circuit with enhanced stability, capable of preventing damage caused by a counter electromotive force of an ultra-directional speaker by controlling, to be within the constant range, a voltage applied to the ultra-directional speaker.
The present invention provides a complex speaker system comprising an ultra-directional speaker system, capable of simultaneously outputting ultra-directional and non-directional signals, the complex speaker system comprising: a signal input unit for receiving an audio input signal to be amplified; an A/D converter for converting an analog input signal into a digital signal; a signal delay unit for delaying a non-directional signal by the amount of time a signal outputted from the ultra-directional speaker system is delayed, and outputting the delayed non-directional signal; a pulse width modulator for pulse-width-modulating the signal outputted from the signal delay unit; and a non-directional amplifier for performing non-directional-amplification on the pulse-width-modulated signal and outputting the same.
The present invention relates to a tunnel information broadcasting system using speakers for a tunnel that have an improved ability to transmit information. More specifically, the present invention relates to a tunnel information broadcasting system comprising: a plurality of sensor units installed in and around a tunnel to individually operate to sense and determine a situation using measured data; a plurality of speakers for a tunnel, the speakers being installed along opposite wall surfaces of the tunnel with a predetermined interval therebetween, each speaker having a horn for sound output and installed such that one surface part of the horn adjacent to a tunnel sidewall is in contact with the tunnel sidewall; an amplifier for amplifying sound signals output to the plurality of speakers; and a main control unit for controlling the amplifier and each speaker for the tunnel to collect surrounding information using signals received from the respective sensor units and to output the collected information, wherein the main control unit delays outputs of the respective speakers for the tunnel that are arranged in the progress direction of a vehicle with respect to the speaker adjacent to the corresponding vehicle. According to the present invention, information can be output as sounds toward a travelling vehicle with a delay using the plurality of speakers for a tunnel, and thus a driver in the vehicle can clearly identify the information, thereby rapidly realizing and responding to the situation.
H04R 3/12 - Circuits for transducers for distributing signals to two or more loudspeakers
H04R 1/32 - Arrangements for obtaining desired frequency or directional characteristics for obtaining desired directional characteristic only
H04R 1/34 - Arrangements for obtaining desired frequency or directional characteristics for obtaining desired directional characteristic only by using a single transducer with sound reflecting, diffracting, directing or guiding means
H04H 20/55 - Arrangements specially adapted for specific applications, e.g. for traffic information or for mobile receivers for traffic information
G08G 1/09 - Arrangements for giving variable traffic instructions
7.
INFORMATION PROVIDING SYSTEM USING ULTRASONIC SPEAKER TRANSMITTING DIFFERENTIAL SIGNAL
The present invention, with respect to an information providing system that uses an ultrasonic speaker to modulate a signal in an audible frequency bandwidth to a carrier wave in an ultrasonic bandwidth and provide information to a receiving terminal through the ultrasonic speaker, provides an information providing system using an ultrasonic speaker that transmits a differential signal, the system characterized by comprising: a differential signal generating module that divides signal frequencies in an audible frequency bandwidth and generates a differential pair signal; and an encoder including a signal processing module that converts digital signals generated by the differential signal generating module to generate analog signals.
The present invention provides an information provision system using an ultrasonic speaker, the system comprising: a fusion speaker part consisting of a speaker in an audio frequency band and a directional speaker in an ultrasonic band; and a transmission signal generation part which generates a signal by fusing a signal in an audio frequency band and a carrier wave in an ultrasonic band which are delivered to the fusion speaker part.
H04B 11/00 - Transmission systems employing ultrasonic, sonic or infrasonic waves
G10K 11/00 - Methods or devices for transmitting, conducting or directing sound in generalMethods or devices for protecting against, or for damping, noise or other acoustic waves in general
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