JP2008148086A - Cartilage conduction speaker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a speaker used by being contacted to cartilage. <P>SOLUTION: A cartilage conduction speaker is composed of two piezoelectric oscillators where a film of PZT (lead zirconate titanate polymer) is formed on both sides of an electrode plate, a spacer keeping the two piezoelectric oscillators parallel with a predetermined interval, and connecting the vicinity of the piezoelectric oscillators, a conducting wire which conducts one of two polar characters of an electric signal to the electrode plate of the piezoelectric oscillator and the other polar to the PZT film part of the piezoelectric oscillator in order to operate the two piezoelectric oscillators reversely, a case fixing one of the two piezoelectric oscillators through an elastic member, and a contact pad contacted to cartilage in the vicinity of a user's ear through the other elastic member of the piezoelectric oscillators. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention is a cartilage conduction speaker, that is, a speaker that converts an electric signal into vibration that can be sensed by humans, and is used by contacting the cartilage near the auricle of a human body.

Patent Document 1 discloses a bone conduction speaker. Patent Document 2 discloses a headphone including a piezoelectric transducer.
JP-A-2005-151183 JP 2003-032768 A

  Conventional bone conduction speakers have been developed on the assumption that they are used in contact with hard bones such as the cheekbone, jawbone, and skull. The inventor of the present application has realized that if a speaker used in contact with the cartilage portion, in particular, the ear canal cartilage portion, can be developed, a speaker that can provide a comfortable feeling for use can be provided. The problem to be solved by the present invention is to provide a speaker that is used in contact with cartilage.

  The cartilage conduction speaker of the present invention includes two piezoelectric vibrators formed by forming a thin film of PZT (lead zirconate titanate polymer) on both sides of an electrode plate, and the two piezoelectric vibrators parallel to each other. One of two electrical signals having two polarities is applied to the electrode plate of the piezoelectric vibrator in order to cause the two piezoelectric vibrators to operate in reverse to each other, with a spacer that connects the periphery thereof while maintaining a predetermined interval. One of the two piezoelectric vibrators is connected to the PZT thin film portion of the piezoelectric vibrator, the case of fixing one of the two piezoelectric vibrators via an elastic member, and the other of the two piezoelectric vibrators. It consists of a contact pad that contacts the cartilage near the user's ear via an elastic member.

The invention according to claim 2 is the cartilage conduction speaker according to claim 1, wherein a thickness of an electrode plate constituting the piezoelectric vibrator is between 40 microns (micrometers) and 60 microns, and a thin film of PZT The thickness of which is between 80 microns and 120 microns.

A third aspect of the present invention is the cartilage conduction speaker according to the first or second aspect, wherein an interval for holding the two piezoelectric vibrators in parallel is 0.8 mm to 1.2 mm. Between.

The invention according to claim 4 is the cartilage conduction speaker according to any one of claims 1, 2, or 3, wherein the electrode plates constituting the two piezoelectric vibrators have an approximately elliptic shape, Its major axis is between 10 and 15 millimeters and its minor axis is between 6 and 10 millimeters.

A fifth aspect of the present invention is the cartilage conduction speaker according to any one of the first, second, third, or fourth aspect, wherein the piezoelectric vibrator and the case, and the elasticity interposed between the piezoelectric vibrator and the contact pad are provided. The central part of the member is a sponge having a rubber shape and the peripheral part being a donut shape.

A sixth aspect of the present invention is the cartilage conduction speaker according to any one of the first, second, third, fourth, and fifth aspects, wherein the electrode plate constituting the piezoelectric vibrator is 42 nickel (of nickel and iron). Alloy).

A seventh aspect of the present invention is the cartilage conduction speaker according to any one of the first, second, third, fourth, fifth, or sixth aspect, wherein the contact pad has adhesiveness and is a user's ear. It is used by adhering to the nearby cartilage.

  Since the present invention is configured as described above, it is suitable for use in contact with cartilage. Since the elasticity of the human cartilage itself can be used, there is an advantage that the structure of the speaker itself can be simplified and good contact can be obtained without a feeling of pressure.

  The present invention is a cartilage conduction speaker configured by providing two piezoelectric vibrators that operate in reverse to each other in parallel to each other via a spacer and housing them in a simple case. The piezoelectric vibrator has a PZT (lead zirconate titanate polymer) thin film on both sides of an electrode plate made of 42 nickel (nickel and iron alloy) with a thickness of 40 microns (micrometers) to 60 microns. To a thickness of 120 to 120 microns is used. In order to reversely operate the two piezoelectric vibrators, a minus lead wire is connected to the electrode plate, and a plus lead wire is connected to a portion outside the PZT thin film portion. Then, the PZT portions on both the front and back surfaces of each piezoelectric vibrator are connected to each other by another conducting wire. The overall size of the cartilage conduction speaker is suitable for contacting with the external auditory canal cartilage, and is composed of, for example, a piezoelectric vibrator having an elliptical shape having a major axis of 12 mm and a minor axis of 8 mm. The peripheral portions of the two piezoelectric vibrators are connected by a spacer so as to be held in parallel while maintaining a distance of about 1 millimeter. The two piezoelectric vibrators thus formed have their front side (the side that contacts the human cartilage, preferably the outer ear cartilage cartilage) centered through a rubber contact, and the periphery of the piezoelectric vibrator is a donut-shaped sponge. The contact pad (preferably an adhesive pad having adhesiveness) made of a soft material is covered with the vibration damping pad made of The back side of the two piezoelectric vibrators is covered with a case made of synthetic resin. In this way, the cartilage conduction speaker constituted as described above is brought into contact with the user's ear canal cartilage and the two lead wires are connected to a music device such as an MP3 player via an amplifier as a speaker. Used.

  Hereinafter, Example 1 will be described with reference to FIGS. FIG. 1 is a view showing a cross section of a cartilage conduction speaker. The piezoelectric vibrators 3 and 4 are each formed by forming a thin film of PZT (lead zirconate titanate polymer) on both front and back surfaces of an electrode plate made of 42 nickel. The connection of the conductors is omitted in FIG. 1 to avoid complications. Each of the piezoelectric vibrators 3 and 4 has an elliptical shape, and has a major axis of 12 millimeters and a minor axis of 8 millimeters. The two piezoelectric vibrators are connected by a spacer 5 at the periphery. A case 1 made of plastic (synthetic resin) and a contact pad 2 made of a soft material are members constituting the appearance of the cartilage conduction speaker. The contact pad 2 can have an adhesive property to facilitate contact with the ear canal cartilage. The piezoelectric vibrators 3 and 4 are fixed to the case 1 and the contact pad 2 by a rear stator 6 made of rubber and a front contact 7 at the center portion thereof, and a donut-shaped rear control made of sponge at the peripheral portion thereof. Mounting balance is assisted by the vibration pad 8 and the front vibration control pad 9. The rear stator 6 is a center stator (center attachment) for extracting vibrations from the periphery. The front contact 7 is a contact (contact vibrator) for transmitting vibration energy. The rear damping pad 8 serves as a cushion for suppressing parasitic vibrations and assisting the mounting balance of the piezoelectric vibrators. The front damping pad 9 serves as a cushion for suppressing parasitic vibration and assisting the mounting balance of the piezoelectric vibrator.

  FIG. 2 is a perspective view showing the external appearance of the cartilage conduction speaker. The members constituting the appearance are only the case 1, the contact pad 2, and the conducting wires 10 and 11. The case 1 is provided with outlets for the conducting wires 10 and 11. The contact pad 2 can be configured to fit into the case 1.

  FIG. 3 is a perspective view showing an appearance of two piezoelectric vibrators constituting the cartilage conduction speaker. The front piezoelectric vibrator 3 is a piezoelectric vibrator on the side in contact with the contact pad 2. The rear piezoelectric vibrator 4 is a piezoelectric vibrator on the side in contact with the case 1. The conducting wire 10 is a minus-side conducting wire connected to the electrode plate of the members constituting the two piezoelectric vibrators 3 and 4. The conducting wire 11 is a plus conducting wire connected to two places outside the PZT thin film portion of the members constituting the two piezoelectric vibrators 3 and 4. In addition, although there are conducting wires 12 and 13 for connecting the PZT thin film portions on the front and back of each piezoelectric vibrator to each other, the illustration is omitted in FIG. 3 to avoid complexity.

  FIG. 4 is a cross-sectional view of a portion of two piezoelectric vibrators. As described above, in addition to connecting the conducting wires 10 and 11, the conducting wire 12 connects the PZT thin film portions 61 and 62 provided on the front and back surfaces of the electrode plate 71 constituting the front piezoelectric vibrator, and the conducting wire 13 is connected. The PZT thin film portions 63 and 64 provided on both the front and back surfaces of the electrode plate 72 constituting the rear piezoelectric vibrator are connected. As a result, the two piezoelectric vibrators vibrate in opposite directions.

  FIG. 5 is a block diagram when the cartilage conduction speaker is connected to the MP3 player. The audio signal output from the MP3 player 40 is amplified through the amplifier 30 and input to the cartilage conduction speaker 20 to vibrate the internal piezoelectric vibrator, and the vibration is used via the contact pad 2. To the ear canal cartilage of the person. Thereby, the user can enjoy music and the like. Instead of the MP3 player 40, other devices that output sound, such as an MD player, a CD player, a mobile phone, a DVD player, and a radio can be used.

  In Example 1 described above, the thickness of the electrode plate was set to 40 to 60 microns and the thickness of the PZT thin film was set to 80 to 120 microns. However, depending on the specification conditions, the thickness of the electrode plate / piezoelectric ceramics, etc. It is possible to manufacture by changing the size. In addition, although the interval for holding the two piezoelectric vibrators in parallel is set to 0.8 mm to 1.2 mm, it has been confirmed that it can be used practically even if this interval is extended to a maximum of about 5 mm. It was. Moreover, although the shape of the electrode plate was approximately elliptical, it was confirmed that a rectangular shape or a circular shape was also practical. Furthermore, although the central part of the elastic member interposed between the piezoelectric vibrator and the case, and between the piezoelectric vibrator and the contact pad is rubber and the peripheral part is a donut-shaped sponge, felt can be used instead of the sponge. The material of the electrode plate is 42 nickel, but a relatively hard metal plate such as brass can also be used. Furthermore, although the contact pad is adhesive, other embodiments are possible in which the contact pad is fixed and used as a hook. The cartilage conduction loudspeaker is suitable for the part of the human body that contacts the external auditory canal cartilage, but is not limited to this. Other uses are possible.

  It can be widely used for devices that enjoy audio, such as mobile phones, MP3 players, CD players, DVD players, and portable televisions.

It is a figure which shows the cross section of a cartilage conduction speaker. It is a perspective view which shows the external appearance of a cartilage conduction speaker. It is a perspective view which shows the external appearance of the part of the two piezoelectric vibrators which comprise a cartilage conduction speaker. It is sectional drawing of the part of two piezoelectric vibrators. It is a block diagram in the case of connecting a cartilage conduction speaker to an MP3 player.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Case 2 Contact pad 3 Front piezoelectric vibrator 4 Rear piezoelectric vibrator 5 Spacer 6 Rear stator 7 Front contactor 8 Rear damping pad 9 Front damping pad 10, 11, 12, 13 Conductor 20 Cartilage conduction speaker 30 Amplifier 40 MP3 players 61, 62, 63, 64 PZT thin film portions 71, 72 Electrode plate

Claims (7)

Two piezoelectric vibrators formed by forming a thin film of PZT (lead zirconate titanate polymer) on both sides of the electrode plate;
A spacer that connects the two piezoelectric vibrators in parallel with each other while maintaining a predetermined interval;
In order to cause the two piezoelectric vibrators to operate in reverse to each other, a conductive wire for transmitting one of the two polar electrical signals to the electrode plate of the piezoelectric vibrator and the other to the PZT thin film portion of the piezoelectric vibrator; ,
A case in which one of the two piezoelectric vibrators is fixed via an elastic member;
A cartilage conduction speaker comprising a contact pad for contacting the other of the two piezoelectric vibrators to the cartilage near the user's ear via an elastic member. The cartilage conduction speaker according to claim 1, wherein a thickness of an electrode plate constituting the piezoelectric vibrator is between 40 microns (micrometers) and 60 microns.
A cartilage conduction speaker in which the thickness of the PZT thin film is between 80 microns and 120 microns. 3. The cartilage conduction speaker according to claim 1, wherein the distance between the two piezoelectric vibrators held in parallel is between 0.8 mm and 1.2 mm. 4. The cartilage conduction speaker according to any one of claims 1, 2, and 3, wherein the electrode plates constituting the two piezoelectric vibrators have an approximately elliptical shape, and a major axis thereof is 10 to 15 millimeters. A cartilage conduction speaker with a minor axis between 6 and 10 millimeters. The cartilage conduction speaker according to any one of claims 1, 2, 3, or 4,
A cartilage conduction speaker in which the central portion of the elastic member interposed between the piezoelectric vibrator and the case, and between the piezoelectric vibrator and the contact pad is rubber and the peripheral portion is a donut-shaped sponge. A cartilage conduction speaker according to any one of claims 1, 2, 3, 4 or 5,
A cartilage conduction speaker in which an electrode plate constituting the piezoelectric vibrator is 42 nickel (an alloy of nickel and iron). A cartilage conduction speaker according to any one of claims 1, 2, 3, 4, 5 or 6,
A cartilage conduction speaker used by the contact pad having adhesiveness and sticking to cartilage near a user's auricle.

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