Sony Corporation

Takahiro Muraguchi

Jun Kishigami

Masao Fujihira

Kazuhiro Akaike

Makoto Yamagishi

Ikuo Shinohara

Kensaku Abe

Kenji Tokushige

An input device of an electronic apparatus including an input detection unit which is provided on the electronic apparatus at a position that is difficult to be seen by a user who uses the input device, and which detects an input operation of the user; a movement distance detection unit that detects a movement distance of an input position over the input detection unit; and an action control unit that controls a predetermined action of the electronic apparatus based on the movement distance detected by the movement distance detection unit.

Input device

An electromagnetic induction type acoustic transducer apparatus including a magnetic gap formed between a plate and a pole piece serving as assemblies of a magnetic circuit, a conductive ring attached to a diaphragm, the diaphragm interposed within the magnetic gap for generating sounds when it is vibrated, and a flat coil disposed in the plate or the pole piece at the position opposing the magnetic gap and of which winding is increased from the vibration direction of the diaphragm to the direction perpendicular to the vibration direction of the diaphragm, wherein a width of the magnetic gap can be reduced.

Acoustic transducer

A speaker apparatus capable of reproducing from low-pitched to high-pitched sounds and a voice reproduction system employing the same. The speaker apparatus includes a speaker unit in which a primary coil is mounted in a gap portion between a plate and a center pole of a magnetic circuit, a secondary coil is disposed within the gap in such a manner as to be fixed to a vibration plate, and a secondary electric current is induced in the secondary coil by a signal current flowing through a primary coil, thereby operating the vibration plate; and a speaker driving circuit adapted to drive the primary coil of the speaker unit in accordance with a digital sound signal.

Speaker apparatus and sound reproduction system employing same

An electromagnetic induction type acoustic transducer including a plate as an assembly of a magnetic circuit and having an opening of a predetermined diameter about a central axis, a pole piece as an assembly of the magnetic circuit and protruded on the central axis, having an outer peripheral diameter smaller than the opening of the plate and having an upper surface located lower than a lower surface of an opening peripheral portion of the plate by a predetermined distance, a lower surface portion of the opening peripheral portion of the plate and an upper surface portion of the pole piece constitute a magnetic gap of the magnetic circuit,

A speaker apparatus which drives an electromagnetic-coupling-type speaker in accordance with a digital signal is provided with a speaker unit, and a plurality of amplifiers corresponding to the number of quantization bits of a digital audio signal. The output terminals of the amplifiers are connected to the respective primary coils, respectively, and the output impedances of the plurality of the amplifiers are made equal to those of the respective primary coils to which the amplifiers are connected. Each bit of each sample of the digital audio signal is amplified by the plurality of the amplifiers and supplied to the respective primary coils, respectively.

Speaker apparatus

A speaker device driving drive coils of a speaker such as an electromagnetically coupled speaker by digital sound signals, where a primary coil of the speaker unit is constituted by 15 pieces of coils, the coils are made to correspond to respective bits excluding MSB of a digital sound of 16 bits issued from a serial/parallel converter, each of the coils are connected in a bridge connection to 4 pieces of FETs respectively opposed to each other and constant current sources are connected to the bridge connection portions whereby a coil drive circuit is constituted, currents from the constant current sources are respectively supplied to the coils and a variable resistor is adjusted by which voltages are changed and the currents of the constant current sources are commonly controlled whereby the volume of the speaker is finely driven.

A headphone includes an acoustic pipe, a loudspeaker unit, a microphone unit and a feedback circuit. The acoustic pipe has an inner diameter substantially equal to that of an external auditory canal. The acoustic pipe has a mounting portion provided at an end thereof for being mounted on the outer ear and has an acoustically non-reflective end at the other end thereof. The loudspeaker unit is provided on one side of the acoustic pipe with a sound emitting face thereof opposed to the inside of the acoustic pipe. The microphone unit is provided on the one side of the acoustic pipe with a sound collecting face thereof opposed to the inside of the acoustic pipe. The feedback circuit feeds back an output signal of the microphone unit to an input side of the loudspeaker unit. The feedback circuit includes an equalizing section. The output signal of the microphone unit is supplied to the loudspeaker unit by way of the equalizing section. The equalizing section has an open loop characteristic wherein an attenuation characteristic in a frequency band other than a frequency band in which noise can be canceled rises higher than an attenuation characteristic in the frequency band in which noise can be canceled.

Headphone apparatus including an equalizer system having an open loop

A light signal transmitting apparatus having first and second light signal terminals and two optical fibers for coupling the first and second light signal terminals to transmit light signals in the opposite directions. The first light signal terminal comprises a separating device for separating a multiplexed light signal in which first and second light signals are multiplexed, first and second light-sensing devices for receiving the first and second light signals thus separated, a detecting circuit for generating a detection signal on the basis of a received output of the second light-sensing device, and a first light emitting device controlled by the detecting circuit so that the first light emitting device emits a third light signal of sufficiently high output level when the second light signal is detected by the detecting circuit and that the first light emitting device emits a third light signal of low output level or disabled when the second light signal is not detected by the detecting circuit. The second light signal terminal comprises a third light-sensing device for receiving the third light signal, second and third light emitting devices for emitting the first and second light signals, and a multiplexer for multiplexing the first and second light signals to provide the multiplexed signal.

Growing community of inventors

Tokyo, Japan

Takahiro Muraguchi