Digital amplifier, three-value signal output method and speaker

• US 9,641,937 B2
• Filed: 01/14/2014
• Issued: 05/02/2017
• Est. Priority Date: 02/28/2013
• Status: Active Grant

• Current Assignee: Clarion Co., Ltd. (Faurecia SA)
• Original Assignee: Clarion Co., Ltd. (Faurecia SA)
• Inventors: Kuromoto, Shinichi
• Primary Examiner(s): Monikang, George
• Application Number:
  US14/769,640
• Publication Number:
  US 20150382109A1
• Time in Patent Office: 1,204 Days
• Field of Search: 330251, 330252, 381 57, 381120
• CPC Class Codes: H03F 1/0205 in transistor amplifiers
• CPC Class Codes: H03F 2200/03 the amplifier being designed for audio applications
• CPC Class Codes: H03F 3/185 with field-effect devices H03F3/187 takes precedence
• CPC Class Codes: H03F 3/2171 with field-effect devices H03F3/2173 - H03F3/2178 take precedence
• CPC Class Codes: H03F 3/2173 of the bridge type
• CPC Class Codes: H04R 2420/01 Input selection or mixing for amplifiers or loudspeakers for hearing aids H04R25/43
• CPC Class Codes: H04R 3/00 Circuits for transducers , loudspeakers or microphones
• CPC Class Codes: H04R 5/04 Circuit arrangements, e.g. for selective connection of amplifier inputs/outputs to loudspeakers, for loudspeaker detection, or for adaptation of settings to personal preferences or hearing impairments combinations of amplifiers H03F3/68; stereophonic systems H04S
• CPC Class Codes: H04S 3/008 in which the audio signals are in digital form, i.e. employing more than two discrete digital channels data reduction aspects thereof based on psychoacoustics G10L19/02

Abstract

Noise is reduced when three-value output is performed. In a digital amplifier 1, a three-value driver 18a associated with a positive electrode and a three-value driver 18b output three-value signals which are inverted to each other, and execute an output of three values on the basis of a differential output of the positive electrode and a negative electrode.

Claims

1. An audio device comprising:

a speaker main body;

a plurality of digital amplifiers each of which corresponds to respective channel; and

a plurality of coils,

wherein each of the plurality of digital amplifiers comprises;

a positive electrode signal output circuit that is associated with a positive electrode and that outputs three-value positive signals; and

a negative electrode signal output circuit that is associated with a negative electrode and that outputs negative signal which is inverted from the positive signal to be output from the positive electrode signal output circuit and which maintains in signal amplitude of the positive signal, the negative electrode signal output circuit outputting the inverted signal at a same timing as a timing of the positive signal,

wherein the positive electrode signal output circuit and the negative electrode signal output circuit are connected to each of the plurality of coils, and the three-value signals that are inverted each other and that have the same amplitude are input at the same timing to each of the plurality of coils.

2. The audio device according to claim 1, wherein a signal representing three values is input from a pre-stage circuit to the positive electrode signal output circuit, the signal representing the three values is branched, inverted and input to the negative electrode signal output circuit.

3. The audio device according to claim 2, wherein each of the positive electrode signal output circuit and the negative electrode signal output circuit has power sources having three kinds of potential outputs, three switches connected to the respective power sources, and a switch control circuit for operating the respective switches, and outputs a three-value signal by switching the respective switches with the switch control circuit.

4. The audio device according to claim 3, wherein a period for which all the three switches are turned off is provided at a switching time when the three switches are switched by the switch control circuit.