Provided is a speaker device configured so that a time lag between a sound signal and a noise cancellation signal can be prevented, worsening of high-frequency characteristics can be avoided, and acoustic characteristics can be improved. A plane diaphragm 11 includes a flexible circuit board 20. A sound voice coil pattern 21 to which drive current corresponding to a sound signal is supplied and a noise cancellation voice coil pattern 22 to which drive current corresponding to a noise cancellation signal is supplied are formed on the flexible circuit board 20 and are formed corresponding to a formed magnetic field of a magnet 13.

A digital sound system suitable for a digital speaker device to directly convert analog sound by a circuit using a 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 modulator, a post filter, s driving circuits, and a power supply circuit to supply power to the modulator, the post filter and the s driving elements, and the s driving circuits are adapted to s digital signal terminals.

A digital/analog conversion apparatus to convert a digital signal into an analog signal. The digital/analog conversion apparatus can generate a high-quality analog signal, even when elements configuring the digital/analog conversion apparatus have variance, with high resolution and a small circuit size. The data conversion apparatus is provided with a first data converter to reduce the number of bits of an input signal, a second data converter to convert the format of the first output signal, and a third data converter for conversion into a code which corresponds to the history of the output from the second data converter.

Provided is a speaker device configured so that a time lag between a sound signal and a noise cancellation signal can be prevented, worsening of high-frequency characteristics can be avoided, and acoustic characteristics can be improved. A plane diaphragm 11 includes a flexible circuit board 20. A sound voice coil pattern 21 to which drive current corresponding to a sound signal is supplied and a noise cancellation voice coil pattern 22 to which drive current corresponding to a noise cancellation signal is supplied are formed on the flexible circuit board 20 and are formed corresponding to a formed magnetic field of a magnet 13.

A digital microphone system, audio control device and control method thereof is related to the method for controlling a digital microphone circuit including receiving a clock signal; detecting that the clock signal is maintained at a predetermined level for a duration; when the duration reaches a given time, switching a transmission type of a data pin; in a data mode, outputting a digital audio signal to a data line via the data pin in an output type; and in a command mode, receiving a command signal from the data line via the data pin in an input type.

The present disclosure provides a method for testing an apparatus which comprises a set of operational subunits each comprising a moving element, wherein the moving elements move between respective first and second extreme positions, the method comprising: transferring to the apparatus stabilization control commands; transferring to the apparatus first latching-commands for latching to the first extreme position a candidate moving element which is a moving element of a candidate operational subunit; when the first latching control commands are in effect, measuring a first output frequency of an oscillator whose output is coupled to the candidate operational subunit in an electrical coupling setup which causes the output frequency of the oscillator to depend on positions of a plurality of moving elements which comprises the candidate moving element; and based on the first output frequency determining a state of the candidate operational subunit.

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.

A direct digital drive audio system and method system and method are presented. The direct digital drive system and method utilizes a digital signal to directly drive the speakers. In one exemplary implementation, an audio system includes a sample register, an convergence adjustment component, an accumulated error register, a digital driver and a speaker. The sample register is coupled to the convergence adjustment component which is coupled to the accumulated error register and the digital driver which in turn is coupled to the speaker. The sample register holds an audio sample. The convergence adjustment component calculates the error for each sample. The accumulated error register stores an accumulated error. The digital driver determines whether to drive on a positive digital value, drive on a negative digital value or not drive. The speaker creates audio sounds based upon a signal from the digital driver.

Provided is an electro-acoustic conversion film that is suitably used for a digital speaker or the like, and that includes a polymer composite piezoelectric body formed by dispersing piezoelectric particles in a viscoelastic matrix formed of a polymer material having viscoelasticity at room temperature, and thin-film electrodes provided on both surfaces of the polymer composite piezoelectric body, and at least one of the thin-film electrodes is divided into a plurality of regions of which an area increases by 2.sup.n times (n is a natural number including 0). Thus, a digital speaker in which reverberation or crosstalk between segments is suppressed is obtained.

Provided is an electro-acoustic conversion film that is suitably used for a digital speaker or the like, and that includes a polymer composite piezoelectric body formed by dispersing piezoelectric particles in a viscoelastic matrix formed of a polymer material having viscoelasticity at room temperature, and thin-film electrodes provided on both surfaces of the polymer composite piezoelectric body, in which at least one of the thin-film electrodes is divided into a plurality of regions having the same area, and the respective regions are coupled in parallel and grouped to correspond to a weight of each bit digit of a parallel PCM digital signal. Thus, an electro-acoustic conversion film by which a digital speaker in which reverberation or crosstalk between segments is suppressed is obtained is provided.