# US 2013/0156231 A1 · Digital/analogue conversion apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0156231 A1 - Document ID: US20130156231A1 - Status: Published application - Kind: A1 - Application number: 13/763,083 - Filed: 2013-02-08 - Published: 2013-06-20 - Earliest claimed: 2006-05-21 - Assignees: Trigence Semiconductor, Inc. - Inventors: AKIRA YASUDA; Junichi Okamura - Web page: https://patentgrep.com/patent/US20130156231A1 ## CPC - H04R 3/08: of electromagnetic transducers - H03G 3/20: Automatic control ({H03G3/005 takes precedence;} combined with volume compression or expansion H03G7/00) - H03H 15/00: Transversal filters (electromechanical filters H03H9/46, H03H9/70) - H03M 3/344: {by filtering other than the noise-shaping inherent to delta-sigma modulators, e.g. anti-aliasing} - H04R 17/005: {using a piezoelectric polymer} - H03M 3/414: {having multiple quantisers arranged in cascaded loops, each of the second and further loops processing the quantisation error of the loop preceding it, i.e. multiple stage noise shaping [MASH] type} - H03M 3/504: {the final digital/analogue converter being constituted by a finite impulse response [FIR] filter, i.e. FIRDAC} - H03M 7/3022: {having multiple quantisers arranged in cascaded loops, each of the second and further loops processing the quantisation error of the loop preceding it, i.e. multiple stage noise shaping [MASH] type} - H04R 1/005: {using digitally weighted transducing elements} - H04R 3/00: Circuits for transducers (arrangements for producing a reverberation or echo sound G10K15/08; amplifiers H03F) - H04R: LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS (producing sounds with frequency not determined by supply frequency G10K) - H03G: CONTROL OF AMPLIFICATION - H03H: IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS (waveguides, resonators, lines or other devices of the waveguide type H01P) - H03M: CODING; DECODING; CODE CONVERSION IN GENERAL (using fluidic means F15C4/00; optical analogue/digital converters G02F7/00; coding, decoding or code conversion, specially adapted for particular applications, see the relevant subclasses, e.g. G01D, G01R, G06F, G06T, G09G, G10L, G11B, G11C, H04B, H04L, H04M, H04N; ciphering or deciphering for cryptography or other purposes involving the need for secrecy G09C) ## Abstract 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. ## Claims ### Claim 1 A digital speaker system comprising: a plurality of driver circuits; a speaker unit having a plurality of inputs and a corn driven by a plurality of voice coils, each of plurality of inputs corresponding to each of the plurality of voice coils and corresponding to each of plurality of the driver circuits; a delta sigma modulator to receive a digital audio signal and generate a first signal; and a mismatch shaper to convert the first signal to generate a second signal and output the second signal to the plurality of driver circuits which are selected according to a selection history of the plurality of driver circuits, wherein each of the plurality of driver circuits amplifies the second signal and generates three valued digital signals by using a switching driver, and wherein each of the plurality of inputs is supplied with three valued digital signals generated by a corresponding driver circuit among the plurality of driver circuits. ### Claim 2 (depends on 1) The digital speaker system according to claim 1 wherein the plurality of the voice coils are wound individually. ### Claim 3 (depends on 1) The digital speaker system according to claim 1 wherein the plurality of the voice coils are bunched and wound. ### Claim 4 (depends on 1) The digital speaker system according to claim 1, comprising: a delay circuit to delay the second signal and supply the plurality of the driver circuits with the delayed second signal. ### Claim 5 (depends on 1) The digital speaker system according to claim 1, comprising: a microphone unit; and a controller to receive a signal from the microphone unit and output a control signal to the delta sigma modulator. ### Claim 6 (depends on 5) The digital speaker system according to claim 5 wherein the microphone unit has a plurality of microphones. ### Claim 7 (depends on 6) The digital speaker system according to claim 6 wherein the microphone unit detects a direction of a peripheral noise. ### Claim 8 (depends on 1) The digital speaker system according to claim 1, comprising: a transmitter to transmit the second signal; and a receiver to receive the transmitted second signal and supply the plurality of the driver circuits with the received second signal. ### Claim 9 A digital speaker system comprising: a first channel; a second channel; and a plurality of digital speakers, each of the plurality of digital speakers having a corn driven by a plurality of voice coils, and each of the first channel and the second channel including: a plurality of driver circuits, a delta sigma modulator to receive a digital audio signal and generate a first signal, a mismatch shaper to convert the first signal to generate a second signal and output the second signal to the plurality of driver circuits which are selected according to a selection history of the plurality of driver circuits, wherein each of the plurality of driver circuits amplifies the second signal and generates three valued digital signals by using a switching driver, and wherein a first group of the plurality of digital speakers among the plurality of digital speakers receives three valued digital signals from the first channel and a second group among the plurality of digital speakers receives three valued digital signals from the second channel. ### Claim 10 (depends on 9) The digital speaker system according to claim 9, comprising: a third channel wherein the first channel is a left channel, the second channel is a right channel, and the third channel is a center channel, and wherein a third group of the plurality of digital speakers among the plurality of digital speakers receives three valued digital signals from the third channel. ### Claim 11 (depends on 9) The digital speaker system according to claim 9, comprising: a third channel wherein a third group of the plurality of digital speakers among the plurality of digital speakers receives three valued digital signals from the first, second, or third channel. ### Claim 12 (depends on 10) The digital speaker system according to claim 10, wherein a speaker unit in the first channel and a speaker unit in the third channel are allocated dynamically and a speaker unit in the second channel and the speaker unit in the third channel are allocated dynamically.