Trigence Semiconductor, Inc.

Thine Electronics, Inc.

Jun-ichi Okamura

Akira Yasuda

Hiroshi Iwamura

Satoshi Miura

Seiichi Ozawa

Yohei Ishizone

Tatsuo Tsujita

A speaker driving device includes a first calculation unit, a first driving signal generation unit and a third calculation unit. The first calculation unit outputs a first calculation signal obtained from a first input signal based on response characteristics according to a first parameter defining an equivalent circuit of a first speaker unit. The first driving signal generation unit generates a first driving signal based on a second driving signal and the first calculation signal. The first driving signal drives a first output speaker unit. The third calculation unit generates a third calculation signal from a second input signal based on response characteristics according to a third parameter defining an equivalent circuit of a third speaker unit. The second driving signal generation unit generates the second driving signal based on the first driving signal and the third calculation signal. The second driving signal drive a second output speaker unit.

Speaker driving device

A speaker driving device including a setting part setting at least one parameter defining an equivalent circuit of a first speaker unit as a first parameter; a first calculator configured to change a first frequency response based on the first parameter, the changed first frequency response being applied to an input signal; and a driving signal generator configured to generate a drive signal for driving a speaker unit based on a first calculation signal, the first calculation signal being obtained by applying the changed first frequency response to the input signal.

A speaker control device in one embodiment includes an oscillator connected in parallel with a drive circuit for driving a speaker, the oscillator changing an oscillation frequency according to a voltage, and a control circuit detecting a variation in the oscillation frequency of the oscillator, and adjusting an amount of current supplied to the speaker by the drive circuit in the case where a variation in the voltage exceeds an allowable value.

Speaker control device and speaker control method

Provided is a digital acoustic system comprising: a &#x394;&#x3a3; modulator that modulates a digital input signal and outputs a digital signal; a post-filter that is connected to the &#x394;&#x3a3; modulator and which performs mismatch shaping to convert the digital signal; a parallel-serial converter that converts the digital signal converted by the post-filter into a digital signal which is serially transmitted; a serial-parallel converter that restores the digital signal converted by the parallel-serial converter; and a drive circuit which receives the digital signal restored by the serial-parallel converter, and drives drive elements to convert the signal into an analog audio signal.

Digital acoustic system

Provided is a selection device including an acquisition section for acquiring digital selection signals, and an output section for outputting selection signals to respective unit cells, each unit cell capable of being commanded to output the value zero. The selection device is characterized in that: each selection signal is for commanding the unit cell to output a value corresponding to that selection signal; the sum of the values to be output as commanded by the respective selection signals, which are output to the respective unit cells, is a value determined in association with the digital selection signal; and if the output corresponding to the digital selection signal is the value zero, then selection signals each commanding to output a non-zero value (N) are output to some of the unit cells.

Selection device

A digital sound system suitable for a digital speaker device to directly convert analog sound by a circuit using a &#x394;&#x3a3; modulator and a mismatch shaping filter circuit to output a plurality of digital signals and a plurality of speakers driven by the plurality of digital signals. A digital speaker driving device includes a &#x394;&#x3a3; modulator, a post filter, s driving circuits, and a power supply circuit to supply power to the &#x394;&#x3a3; modulator, the post filter and the s driving elements, and the s driving circuits are adapted to s digital signal terminals.

Digital speaker driving apparatus

As one embodiment a drive circuit is disclosed. When a three-value signal including a value representing zero is input, the drive circuit outputs two two-value signals that drive two drive elements such that the difference between values representing the two two-value signals corresponds to a value representing the input three-value signal. When the value of the input three-value signal represents zero, output signals are determined in accordance with the input history of the three-value signal. The drive circuit may also be provided with a memory that records a flag value that is reversed in accordance with the input history of the input three-value signal, and the combination of the output two two-value signals being determined in accordance with the flag.

Drive circuit

A speaker control device in one embodiment includes a time to digital converter connected to a drive power source in series with a drive circuit for driving a plurality of coils of a speaker, the converter outputting a digital data in accordance with a voltage of the drive power source, and a monitor circuit detecting a state of the plurality of coils of the speaker based on digital data output by the time to digital converter.

Speaker control device

An acoustic playback system including a digital filter; and a plurality of digital modulators each of which output a digital signal to one of a plurality of speakers driven by digital signals having different play back bandwidths; wherein the digital filter converts a digital audio signal which is input into a plurality of digital audio signals of a plurality of frequency bandwidths corresponding to play back bandwidths of the speakers, and outputs each of the digital audio signals of the plurality of frequency bandwidths to one of the plurality of digital modulators; each of the digital modulators outputs the modulated digital signal to the speaker of a play back bandwidth corresponding to a frequency bandwidth of the digital audio signal which is input by performing miss-match shaping after noise shaping to a digital audio signal; and each number of bits of a digital signal of the digital modulators is different.

Acoustic playback system

Provided is a data converter which is provided with a clock signal input part which inputs a clock signal, and an input part which inputs an input signal, a sampling part which, in response to the clock signal input to the clock signal input part, performs sampling of the input signal input to the input part, and a signal processing part which performs signal processing according to the sampling cycle and outputs an output signal, wherein when the cycle of the clock signal input to the clock signal input part becomes longer, the output signals output by the signal processing part are reduced.

Converter

A selection device includes an acquisition part to acquire digital selection signals, and an output part to output selection signals to respective unit cells, each unit cell capable of being commanded to output the value zero. In the selection device, each selection signal is to command the unit cell to output a value corresponding to that selection signal; the sum of the values to be output as commanded by the respective selection signals, which are output to the respective unit cells, is a value determined in association with the digital selection signal; and if the output corresponding to the digital selection signal is the value zero, then selection signals each commanding to output a non-zero value (N) are output to some of the unit cells.

An inverter for generating a plurality of alternating signals to be supplied to a motor, the motor having a plurality of phases and a plurality of coils arranged at each of the plurality of phases is provided. The inverter is a motor driving inverter characterized in including a multi-level pulse-density modulator configured to modulate a signal that fluctuates periodically and controls rotation of the motor; and a plurality of switching elements configured to generate each of the plurality of alternating signals by controlling an ON/OFF of a direct current according to selection by an output signal of the pulse-density modulator.

Inverter for a driving a motor

An acoustic playback system including a digital filter; and a plurality of digital modulators each of which output a digital signal to one of a plurality of speakers configured with speakers driven by digital signals having different play back bandwidths; wherein the digital filter converts a digital audio signal which is input into a plurality of digital audio signals of a plurality of frequency bandwidths corresponding to play back bandwidths of the plurality of speakers, and outputs each of the digital audio signals of the plurality of frequency bandwidths to one of the plurality of digital modulators; each of the plurality of digital modulators outputs the modulated digital signal to the speaker of a play back bandwidth corresponding to a frequency bandwidth of the digital audio signal which is input by performing miss match shaping after noise shaping to a digital audio signal which is input; and each number of bits of a digital signal which is output by each of the digital modulators is different is provided.

The disclosed conversion device converts an analog input signal into a digital signal and outputs thereof, wherein the conversion device comprises a feedback signal generator for performing mismatch shaping on the digital signal that has been converted and output, and then performing digital-analog conversion to generate a feedback signal; a subtractor for subtracting the feedback signal from the analog input signal and outputting thereof; a serial-parallel converter for converting the signal output from the subtractor into a plurality of parallel signals and outputting thereof; a vector filter for performing signal processing on the plurality of parallel signals output by the serial-parallel converter and outputting a plurality of signals; a quantizer for quantizing the plurality of signals output by the vector filter and outputting digital signals; and a parallel-serial converter for converting the digital signals output by the quantizer into serial signals and outputting thereof.

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Tokyo, Japan

Jun-ichi Okamura