JPH1169486A - Full surface drive type speaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide high electroacoustic transducing efficiency by providing a means for supporting a non-magnetic and non-conductive plate member so as to be vibrated and a magnetic film for passing through a current crossing with the magnetic flux of a magnetic passage for passing through the magnetic flux by a magnetic generation means. SOLUTION: A base 2 is composed of a magnetic material such as soft iron or the like and magnets 1 and 1' are attached by bringing the magnetic pole surfaces of mutually opposite polarities into contact with the base 2. The magnetic poles on the opposite side of the magnetic poles attached to the base 2 of the magnets 1 and 1' are bridged by a diaphragm 3 and the two magnetic poles are turned to the opposite polarities. One end of conductors 4 and 4' is respectively connected to both end parts in a (y) direction of the diaphragm 3. The other ends of the conductors 4 and 4' are respectively connected to terminals 5 and 5' and the terminals 5 and 5' are disposed in an electrically insulated state to the upper part of the attachment part on the side of the magnet 1 of the diaphragm 3. The diaphragm 3 is provided with a two-layer structure provided with a highly magnetically permeable and conductive first layer and a non-magnetic and non-conductive second layer. By making the current flow through the terminals 5 and 5', the diaphragm 3 is vibrated in a direction orthogonal to the magnetic flux and the current.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electro-acoustic transducer, and more particularly, to a diaphragm using a magnetic material, in which a magnetic flux is passed along a surface of the diaphragm, and a current flows in a direction interlinking with the magnetic flux. The present invention relates to an overall driving speaker that vibrates the speaker.

[0002]

2. Description of the Related Art Magnetic flux is passed through a diaphragm made of a magnetic material,
An electro-acoustic transducer that acoustically vibrates a diaphragm by flowing an audio current in a direction intersecting with a magnetic flux is disclosed in, for example, Japanese Patent Publication No.
It is known as described in JP-A-936.

In this device, as shown in FIG. 10, the magnetic poles 14 and 15 of the magnets 11 and 11 'are bridged by a vibrating plate 13 made of a metallic magnetic material. A magnetic current flows through the diaphragm 13 through the lead wires 16 and 17, and an audio current flows in a direction intersecting with the magnetic flux as shown by a dotted arrow.

In this device, due to the interaction between the magnetic flux in the diaphragm 13 and the current, the diaphragm 13 vibrates in a direction orthogonal to the directions of the magnetic flux and the current, and generates sound corresponding to the current. That is, the electro-acoustic conversion device converts an electric signal into an acoustic signal.

[0005]

Since the above-described electroacoustic transducer uses a diaphragm made of a metallic magnetic material, the vibration system has high rigidity and heavy weight. An electroacoustic transducer using such a vibration system has low electroacoustic conversion efficiency and is not practical.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to realize a full-drive speaker having high electro-acoustic conversion efficiency while using a diaphragm for concentrating magnetic flux. .

[0007]

[Means for Solving the Problems]

(1) The invention according to claim 1 for solving the problem includes a non-magnetic and non-conductive plate member, a support means for supporting the plate member so as to vibrate, a magnetism generating means, and a cover provided on the plate member. And a conductive magnetic film forming a magnetic path for passing a magnetic flux generated by the magnetic generating means and an electric path for passing a current interlinking the magnetic flux of the magnetic path.

According to the first aspect of the present invention, the plate member on which the magnetic film is adhered serves as a vibration plate, and magnetic flux concentrates in the magnetic film. Then, due to the interaction with the magnetic flux, the diaphragm vibrates according to the current supplied from the outside to the current path.

The vibration characteristics of the diaphragm are mainly governed by the mechanical characteristics of the plate member. Therefore, the frequency characteristics can be adjusted by selecting the material and thickness of the plate member. (2) According to a second aspect of the present invention, in the first aspect of the present invention, the magnetic films are separated so as to be parallel to each other in a direction intersecting with the magnetic flux, and the current is supplied in the same direction. Characterized by a plurality of strips connected in series so as to flow.

According to the second aspect of the present invention, acoustic vibration is efficiently generated by the current flowing through the plurality of strips connected in series. (3) The invention according to claim 3 for solving the problem is characterized in that at least one end side is open and the open end is a unipolar magnetic pole, and a substantially cylindrical magnetism generating means is provided on the one end side of the magnetism generating means. A non-magnetic and non-conductive plate member disposed so as to close the opening, and a magnetic path which is attached to the plate member and passes a magnetic flux generated by the magnetism generating means radially with respect to the center of the plate member. A conductive magnetic film forming an electric path for passing a current interlinking with the magnetic flux of the magnetic path spirally with respect to the center of the plate member.

According to the third aspect of the present invention, the magnetic flux is radially concentrated in the magnetic film attached to the plate member. Then, due to the interaction with the magnetic flux, the plate member vibrates according to the current supplied from the outside to the spiral current path. Since the current path has a spiral shape, the current path per area of the magnetic film is lengthened, and efficient electro-acoustic conversion is performed.

(4) The invention according to claim 4 for solving the problem is characterized in that, in the invention according to claim 3, the magnetism generating means has a column member made of a magnetic material in an axial direction in the cylinder. .

According to the fourth aspect of the present invention, the column member performs a magnetic flux collecting operation to improve radial characteristics of magnetic flux. (5) An invention according to claim 5 for solving the problems is provided by a substantially cylindrical first magnetic generating means having at least one end open and an open end serving as a unipolar magnetic pole; An end is a magnetic pole having the same polarity as the magnetic pole of the first magnetic generating means, and the magnetic pole is disposed relatively to the first magnetic generating means such that the magnetic pole faces the magnetic pole of the first magnetic generating means. A substantially cylindrical second magnetic generating means, and the magnetic pole of the first magnetic generating means and the second magnetic generating means.
A non-magnetic and non-conductive plate member disposed between the magnetic poles of the magnetic generating means, and a magnetic flux generated by the first and second magnetic generating means attached to the plate member; A conductive magnetic film forming a magnetic passage radially passing through the center of the plate member and an electric passage spirally passing a current interlinking with the magnetic flux of the magnetic passage around the center of the plate member. Features.

According to the fifth aspect of the present invention, the magnetic flux is radially concentrated in the magnetic film attached to the plate member. Then, due to the interaction with the magnetic flux, the plate member vibrates according to the current supplied from the outside to the spiral current path.

Since the current path has a spiral shape, the current path per area of the magnetic film becomes longer.
By utilizing the sum of the magnetic fluxes of the two magnetic generating means,
Efficient electroacoustic conversion is performed.

(6) According to a sixth aspect of the present invention, to solve the problem, in the fifth aspect of the invention, at least one of the first magnetic generating means and the second magnetic generating means is provided in a cylinder. A column member made of a magnetic material is provided in the axial direction.

According to the sixth aspect of the present invention, the column member performs a magnetic flux collecting operation to improve radial characteristics of magnetic flux. (7) The invention according to claim 7 for solving the problem is the invention according to any one of claims 3 to 6, wherein the magnetic film has a property of suppressing the deflection of the radial magnetic path. Features.

According to the seventh aspect of the present invention, the radial characteristics of the magnetic path are maintained by the properties of the magnetic film of the magnetic path. (8) The invention of claim 8 for solving the problem is characterized in that, in any one of the inventions of claims 1 to 7, the magnetic film is a thin film of a high magnetic permeability metal.

According to the eighth aspect of the present invention, the magnetic flux is concentrated at a high density in the thin film of the high magnetic permeability metal. (9) The invention of claim 9 for solving the problem is characterized in that, in the invention of claim 8, the high magnetic permeability metal is permalloy.

According to the ninth aspect of the present invention, the magnetic flux is concentrated at a high density in the permalloy thin film. (10) According to a tenth aspect of the present invention for solving the problems, in any one of the first to ninth aspects of the present invention, the plate member is a polymer material film.

According to the tenth aspect of the present invention, the rigidity and weight of the diaphragm are reduced by using a film made of a polymer material.

[0022]

Embodiments of the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiment.

(First Example of Embodiment of the Invention) FIG. 1 shows a schematic configuration of a full-drive speaker according to the present invention. This speaker is a first example of an embodiment of the present invention.

(Configuration) The configuration of the speaker will be described. As shown in FIG. 1, the present speaker has a pair of magnets 1, 1 '. The magnets 1, 1 'are an example of an embodiment of the magnetic generating means in the present invention. The magnets 1, 1 'are mounted on a base 2. The base 2 is made of, for example, a plate of a magnetic material such as soft iron. The magnets 1, 1 ′ have their pole faces of opposite polarities in contact with the base 2 and are attached by, for example, bonding.

The magnetic poles of the magnets 1 and 1 ′ opposite to the magnetic poles attached to the base 2 are bridged by the diaphragm 3. The two magnetic poles to be bridged are magnetic poles of opposite polarities. The rear surfaces of both ends of the diaphragm 3 in the x direction in FIG. 1 are respectively attached to the magnetic pole surfaces of the magnets 1 and 1 ′ by, for example, bonding. The magnets 1, 1 'and the base 2 are an example of an embodiment of the support means in the present invention.

The vibrating plate 3 is substantially a flat plate. However, the magnets 1 and 1 'are formed so as to form a corrugation in the vicinity of the attachment portion to the magnetic pole surface. These corrugated parts are the diaphragm 3
Is formed.

One end of each of the conducting wires 4 and 4 'is connected to both ends of the diaphragm 3 in the y direction in FIG. The other ends of the conductors 4, 4 'are connected to terminals 5, 5', respectively. The terminals 5 and 5 ′ are disposed above the mounting portion of the diaphragm 3 on the side of the magnet 1 ′ while being electrically insulated.

FIG. 2 shows a cross section of the diaphragm 3. As shown in the figure, the diaphragm 3 has a two-layer structure of a highly magnetically and electrically conductive first layer 31 and a non-magnetic and electrically non-conductive second layer 32.

The first layer 31 is formed of a thin film of a high magnetic permeability metal magnetic material such as permalloy. First layer 3
1 is an example of an embodiment of a magnetic film according to the present invention. The high magnetic permeability metal magnetic material is an example of the embodiment of the high magnetic permeability metal in the present invention. The metal magnetic material is not limited to Permalloy, and may be another high magnetic permeability alloy. Metal magnetic materials generally have conductivity.

The second layer 32 is made of, for example, a plate or film of a polymer material such as polyester. The second layer 32 is an example of an embodiment of the plate member in the present invention. The plate member is not limited to polyester and may be made of another resin material, for example, polyethylene, polyimide, or the like.

The first layer 31 is formed in close contact with a plate member forming the second layer 32 by, for example, plating or sputtering. The thickness of the first layer 31 is, for example, several hundred nm.
To about several μm. The thickness of the second layer 32 is, for example, about several tens of μm.

FIG. 1 shows a diaphragm 3 having such a two-layer structure.
However, the first layer 31 is attached to the magnetic poles of the magnets 1 and 1 'with the second layer 32 as the back side and the second layer 32 as the back side. With such a configuration, a highly permeable first magnetic pole is provided between the magnetic poles of the magnets 1 and 1 '.
A magnetic path is formed by the layer 31 of FIG.

As a result, the magnetic flux between the magnetic poles of the magnets 1 and 1 ′ passes through the first layer 31 in a concentrated manner. Since the magnetic flux intensively passes through the thin layer, the magnetic flux density in the first layer 31 is increased. For example, about 0.8 T (tesla) can be used without using a very strong magnet 1, 1 '. Can easily be achieved. The magnetic flux is distributed almost uniformly along the surface of the diaphragm.

FIG. 3 shows a simulation result of the magnetic flux density distribution in the first layer 31. As shown in the drawing, a magnetic flux density of 0.857 to 0.872 T is obtained in a range of ± 0.0113 m in the x direction from the center of the diaphragm 8, that is, over substantially the entire effective length of the diaphragm 8 in the x direction. Can be

The conductors 4 and 4 ′ are connected to such a first layer 31.
Is to be connected to. Thereby, the terminal 5
Thus, an electric path is formed to reach the terminal 5 'through the conductor 4, the first layer 31, and the conductor 4'. This electric path links with the magnetic path in the first layer 31. The electric passages are distributed almost uniformly along the surface of the diaphragm 3.

(Operation) The operation of the present speaker will be described. When, for example, an audio current is passed through the terminals 5 and 5 ′ through an electric path by current supply means (not shown), the interaction between the magnetic flux and the current in the first layer 31 causes the diaphragm 3 to move in the direction of the magnetic flux and the current. Vibrates in a direction perpendicular to the plate, that is, in a direction perpendicular to the plate surface. At this time, the diaphragm performs a piston motion by a driving force acting almost uniformly on its entire surface, thereby generating a compression wave in the surrounding air. That is, the electric signal is converted into an acoustic signal.

The vibration characteristics of the diaphragm 3 are governed by the mechanical characteristics of the plate members constituting the second layer 32 occupying most of the thickness. A plate member, such as a polyester film, that forms the second layer 32 has a lower rigidity and weight than a metal plate having the same thickness. For this reason, the amplitude of the piston movement increases, and the sound pressure level can be improved. That is, it is possible to realize a full-surface drive type speaker having high electroacoustic conversion efficiency.

The vibration characteristics of the diaphragm 3 can be changed by selecting the material and thickness of the plate member forming the second layer 32. This increases the degree of freedom in design and facilitates sound quality design and the like.

The above is an example in which the first layer 31 is provided so as to continuously cover the surface of the second layer.
For example, as shown in FIG. 4, a plurality of parallel strips 311 in a direction intersecting with the magnetic flux are formed, and the plurality of strips 311 are connected in series with the same polarity by lead wires 312. You may do it. The strip 311 is an example of the embodiment of the strip in the present invention. By doing so, the same current is repeated a plurality of times and interlinks with the magnetic flux, so that acoustic vibration with high efficiency per current can be generated.

(Second Example of Embodiment of the Invention) FIG. 5 shows a schematic configuration of a second example of the embodiment of the present invention. FIG.
(A) is a plan view, and (b) is an AA cross-sectional view. In FIG. 5B, some illustrations are omitted.

(Configuration) The configuration of the speaker will be described. As shown in FIG. 5, the speaker has a magnet 1. Magnet 1
Has a cylindrical shape and is magnetized in its axial direction.
The magnet 1 is an example of an embodiment of the magnetism generating means in the present invention.

The use of the cylindrical magnet 1 is preferable in that a general cylindrical magnet for a speaker can be used. In addition,
The magnet is not limited to a cylinder, but may be another magnet such as, for example, an elliptic cylinder or a rectangular cylinder, which forms a cylinder having an appropriate cross-sectional shape. Further, a plurality of bar magnets may be arranged in a cylinder to substantially form a cylinder.

The magnet 1 is mounted on a base 2. The base 2 is made of, for example, a plate of a magnetic material such as soft iron. The magnet 1 has one magnetic pole surface in contact with the base 2 and is attached by, for example, bonding.

The diaphragm 3 is attached to the other magnetic pole of the magnet 1. The diaphragm 3 has a disk shape. Disc-shaped diaphragms are preferred because they do not have directivity and anisotropy. When the magnet 1 is, for example, an elliptical cylinder or a rectangular cylinder, the diaphragm 3 has a shape corresponding to the cross-sectional shape of the cylindrical body.

The diaphragm 3 has a peripheral back surface attached to the magnetic pole surface of the magnet 1 by, for example, bonding. Thus, the opening surface of the cylindrical magnet 1 is closed by the diaphragm 3.

One end of a conducting wire 4 is connected to the center of the diaphragm 3. One end of a conducting wire 4 ′ is connected to the periphery of the diaphragm 3. The other ends of the conductors 4, 4 'are connected to terminals 5, 5', respectively. The terminals 5 and 5 ′ are disposed above the mounting portion of the diaphragm 3 to the magnet 1 in a state of being electrically insulated.

FIG. 6 shows an enlarged cross section of the diaphragm 3.
As shown in the figure, the diaphragm 3 has a two-layer structure of a highly magnetically and electrically conductive first layer 31 and a non-magnetic and electrically non-conductive second layer 32.

The first layer 31 and the second layer 32 are respectively similar to the first layer 31 and the second layer 32 of the diaphragm 3 in the speaker shown in FIG. However, the first layer 31 is partially removed by, for example, etching or the like, so that a spiral pattern is formed from the center to the periphery of the diaphragm 3. The number of turns (the number of turns) of the spiral pattern is, for example, about several tens of turns. Between adjacent turns of the spiral pattern, the first
The clearance 33 in which the layer 31 does not exist is formed.

The diaphragm 3 having such a two-layer structure is attached to the magnet 1 with the first layer 31 on the front side and the second layer 32 on the back side. With such a configuration, the opening of the cylindrical magnet 1 is covered with the first layer 31 having high magnetic permeability. For this reason, the magnetic flux of the magnet 1 concentrates and passes through the first layer 31.

Since the magnet 1 is cylindrical, the magnetic flux passes through the first layer 31 along the surface of the diaphragm 3 and radially with respect to the center of the diaphragm 3. The magnetic flux passes between the center of the diaphragm 3 and the center of the base 2 in the axial direction, for example, as indicated by a broken line.

As described above, a radial magnetic path is formed in the first layer 31. Since the magnetic flux intensively passes through the thin layer, the magnetic flux density in the first layer 31 is increased,
Even if a very strong magnet is not used, a magnetic flux density of, for example, about 0.8 T (tesla) can be easily achieved.

The formation of a radial magnetic path in the first layer 31 could be confirmed by analysis using the finite element method. At this time, it was found that the magnetic path tends to deflect in the circumferential direction of the spiral pattern as it approaches the center of the diaphragm 3. Such a deflection weakens the radial properties of the magnetic path.

In order to compensate for this, the cross-sectional area of the first layer 31 is reduced as it approaches the center of the spiral, or the magnetic permeability of the first layer 31 is reduced as it approaches the center of the spiral. Then, the magnetic resistance in the circumferential direction of the spiral may be increased to suppress the degree of deflection of the magnetic flux in the circumferential direction. Alternatively, the clearance 33 of the spiral pattern may be reduced toward the center of the spiral to reduce the radial reluctance to improve the radial characteristics of the magnetic flux. In this manner, the first layer 31 can be provided with the property of suppressing the deflection of the radial magnetic path.

The conductors 4 and 4 ′ are connected to such a first layer 31.
Connected to. As a result, from the terminal 5 to the conductor 4, the first
An electric path reaching the terminal 5 ′ via the layer 31 (spiral pattern) and the conductor 4 ′ is formed. The spiral electric path interlinks with the radial magnetic path. Since the electric passage is formed in a spiral shape, the length interlinking the magnetic flux is increased.

(Operation) The operation of the present speaker will be described. When, for example, an audio current is supplied to the electric path through the terminals 5 and 5 ′ by a current supply unit (not shown), the interaction between the magnetic flux and the current in the first layer 31 causes the diaphragm 3 to move in the direction of the magnetic flux and the current. Vibrates in a direction perpendicular to the plate, that is, in a direction perpendicular to the plate surface. At this time, the diaphragm 3 performs a piston motion by a driving force acting almost uniformly on the entire surface thereof, thereby generating a compression wave in the surrounding air. That is, the electric signal is converted into an acoustic signal.

In this case, when the current flows in a spiral shape, the current intersects with the same magnetic flux a plurality of times (several tens of times) to generate a driving force. For this reason, the efficiency of generating sound pressure per current is increased. That is, an efficient full-surface drive type speaker can be obtained.

The vibration characteristics of the diaphragm 3 are governed by the mechanical characteristics of the plate member constituting the second layer 32 occupying most of the thickness. A plate member, such as a polyester film, that forms the second layer 32 has a lower rigidity and weight than a metal plate having the same thickness. For this reason, the amplitude of the piston movement increases, and the sound pressure level can be improved. That is, it is possible to realize a full-surface drive type speaker having high electroacoustic conversion efficiency.

The vibration characteristics of the diaphragm 3 can be changed by selecting the material and thickness of the plate member forming the second layer 32. This increases the degree of freedom in design and facilitates sound quality design and the like.

(Third Example of Embodiment of the Invention) FIG.
9 shows a third example of the embodiment of the present invention. In FIG.
Parts similar to those in FIG. 5 are denoted by the same reference numerals, and description thereof is omitted. In this example, a column member 21 made of a magnetic material such as soft iron is provided in the center of the base 2 in the axial direction. The column member 21 is an example of an embodiment of the column member in the present invention. The column member 21 may be formed integrally with the base 2.

The column member 21 forms a magnetically permeable magnetic path between the center of the diaphragm 3 and the center of the base 2 to collect magnetic flux at the center. Thereby, the radial component of the magnetic flux passing through the magnetic film of the diaphragm 3 is enhanced, and more efficient electroacoustic conversion can be performed. Although FIG. 7 shows an example in which a gap is provided between the tip of the column member 21 and the diaphragm 3, the tip of the column member 21 may be fixed to the center of the diaphragm 3. Thereby, the radial component of the magnetic flux passing through the magnetic film of the diaphragm 3 is further enhanced.

(Fourth Example of Embodiment of the Invention) FIG.
4 shows a fourth example of an embodiment of the present invention. In FIG.
Parts similar to those in FIG. 5 are denoted by the same reference numerals, and description thereof is omitted. In this example, a cylindrical magnet 1 'is arranged to face the magnet 1. Here, the magnet 1 is an example of an embodiment of the first magnetism generating means in the present invention. The magnet 1 'is an example of an embodiment of the second magnetism generating means in the present invention. The magnets 1 and 1 ′ are opposed to each other with the diaphragm 3 interposed therebetween such that the magnetic poles face each other. The magnet 1 ′ is electrically insulated from the magnetic film of the diaphragm 3.

A yoke 2 'made of a plate made of a magnetic material such as soft iron is attached to the other magnetic pole of the magnet 1'. The yoke 2 'serves as a return path for the magnetic flux of the magnet 1'. The yoke 2 'is provided with a plurality of holes 20. The hole 20 provides an entrance for an acoustic signal.
The yoke 2 'can be omitted. This is preferable in that the entrance and exit of the acoustic signal are widened.

In this device, since the magnetic flux related to the electroacoustic conversion increases by the amount of the added magnet 1 ′, it is possible to obtain a full-drive speaker with higher sensitivity than the device shown in FIG.

(Fifth Embodiment of the Invention) FIG.
5 shows a fifth example of an embodiment of the present invention. In FIG.
7 and 8 are denoted by the same reference numerals and description thereof is omitted. In this example, column members 21 and 21 'made of a magnetic material such as soft iron are provided on a base 2 and a yoke 2'. The column members 21, 21 'are provided at the center of the base 2 and the yoke 2', respectively. The column members 21 and 21 'may be formed integrally with the base 2 and the yoke 2', respectively.

Since the column members 21 and 21 'collect the magnetic flux at the center of the diaphragm 3, the radial component of the magnetic flux in the magnetic film of the diaphragm 3 is strengthened as in the case of FIG. Because of the synergistic effect with the use of the opposed magnets 1 and 1 ′, the most sensitive electro-acoustic conversion can be performed among the four examples.
Note that one of the column members 21 and 21 'can be omitted.

In each of the above embodiments of the present invention, the magnetic film is provided on the surface of the plate member. However, the magnetic film may be provided on the back surface of the plate member. Further, it may be provided on both sides of the plate member. By providing the magnetic film on both sides of the plate member, the magnetic flux of the magnet can be more effectively used.

[0067]

As described above in detail, according to the first aspect of the present invention, since the plate member on which the magnetic film is adhered is the diaphragm, the sound pressure characteristics can be improved by selecting the material and thickness of the plate member. Accordingly, it is possible to realize an all-drive speaker having high electro-acoustic conversion efficiency while using a diaphragm for concentrating magnetic flux.

According to the second aspect of the present invention, acoustic vibration can be efficiently generated by the current flowing through the plurality of strips connected in series. In the invention of claim 3,
Since the diaphragm is a plate member covered with a magnetic film forming a radial magnetic path and a spiral electric path, it is possible to realize a highly efficient full-drive speaker using a diaphragm that concentrates magnetic flux. it can.

According to the fourth aspect of the present invention, since the magnetic column member is provided in the cylinder of the magnetic generating means in the axial direction, the radial characteristic of the magnetic path is improved by the magnetic flux concentration effect, and the electroacoustic Conversion efficiency is improved.

Further, in the invention of claim 5, since two magnetism generating means opposed to each other are used, the magnetic force relating to the electroacoustic conversion is increased, and the electroacoustic conversion efficiency is improved. Also,
According to the sixth aspect of the invention, since the magnetic column member is provided on at least one of the two magnetism generating means, the radial characteristic of the magnetic path is improved by the magnetic flux concentration effect, and the electroacoustic conversion efficiency is improved.

According to the seventh aspect of the present invention, since the magnetic film has the property of suppressing the deflection of the magnetic path, the radial characteristics of the magnetic path are maintained, and the electroacoustic conversion efficiency is improved.

Further, according to the invention of claim 8, the magnetic flux is concentrated at a high density in the thin film of the high magnetic permeability metal, and an efficient full-surface drive type speaker can be realized. Further, according to the ninth aspect of the present invention, the magnetic flux is concentrated at a high density in the permalloy thin film, and an efficient full-surface drive type speaker can be realized.

Further, according to the tenth aspect of the present invention, the rigidity and weight of the diaphragm are reduced by the film of the polymer material, and a full-surface drive type speaker with high conversion efficiency can be realized.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of an example of an embodiment of the present invention.

FIG. 2 is a diagram showing a cross section of a diaphragm in an example of an embodiment of the present invention.

FIG. 3 is a graph showing a simulation result of a magnetic flux density distribution in a first layer of the diaphragm.

FIG. 4 is a diagram showing another example of the configuration of the diaphragm in one example of the embodiment of the present invention.

FIG. 5 is a diagram showing a schematic configuration of an example of an embodiment of the present invention.

FIG. 6 is a diagram showing a cross section of a diaphragm in one example of an embodiment of the present invention.

FIG. 7 is a diagram illustrating a schematic configuration of an example of an embodiment of the present invention.

FIG. 8 is a diagram showing a schematic configuration of an example of an embodiment of the present invention.

FIG. 9 is a diagram showing a schematic configuration of an example of an embodiment of the present invention.

FIG. 10 is a diagram showing a schematic configuration of a conventional example.

[Explanation of symbols]

 Reference Signs List 1, 1 'magnet 2 base 2' yoke 3 diaphragm 4, 4 'conducting wire 5, 5' terminal 31 first layer 32 second layer 33 clearance 21, 21 'pillar member 20 punched hole 11, 11' magnet 13 Diaphragm 14, 15 Magnetic pole 16, 17 Lead wire

Claims (10)

[Claims] A non-magnetic and non-conductive plate member; a support means for oscillatingly supporting the plate member; a magnetic generation means; and a magnetic flux which is applied to the plate member and generated by the magnetic generation means. An all-drive speaker comprising: a magnetic path that passes through the magnetic path; and a conductive magnetic film that forms an electric path that passes a current interlinking with the magnetic flux of the magnetic path. 2. The method according to claim 1, wherein the magnetic film is a plurality of strips that are separated so as to be parallel to each other in a direction interlinking with the magnetic flux and are connected in series so that current flows in the same direction. The full-surface drive type speaker according to claim 1, wherein: 3. A substantially cylindrical magnet generating means having at least one open end and an open end serving as a unipolar magnetic pole, and a non-magnetic member disposed at one end of the magnet generating means so as to close the opening. A magnetic and non-conductive plate member, a magnetic path attached to the plate member, and passing a magnetic flux generated by the magnetism generating means radially with respect to the center of the plate member; A full-drive speaker, comprising: a conductive magnetic film that forms an electric passage that spirally passes through the center of the plate member. 4. The loudspeaker according to claim 3, wherein the magnetism generating means has a magnetic column member in an axial direction in the cylinder. 5. A substantially cylindrical first magnetic generating means having at least one open end and an open end serving as a unipolar magnetic pole, and at least one open end having an open end of said first magnetic generating means. A substantially cylindrical second magnetic pole disposed relative to the first magnetic generation means such that the magnetic pole has the same polarity as the magnetic pole, and the magnetic pole faces the magnetic pole of the first magnetic generation means. A magnetism generating means, a non-magnetic and non-conductive plate member disposed between the magnetic pole of the first magnetism generation means and the magnetic pole of the second magnetism generation means, A magnetic path through which the magnetic flux generated by the first and second magnetic generating means passes radially with respect to the center of the plate member, and a current interlinking with the magnetic flux of the magnetic path spirally with respect to the center of the plate member. A conductive magnetic film constituting an electric passage through which; An all-drive loudspeaker comprising: 6. The apparatus according to claim 5, wherein at least one of the first magnetic generating means and the second magnetic generating means has a magnetic column member in an axial direction in the cylinder. Fully driven speaker. 7. The magnetic film according to claim 3, wherein the magnetic film has a property of suppressing deflection of the radial magnetic path.
An overall drive speaker according to any one of claims 1 to 6. 8. The magnetic recording medium according to claim 1, wherein said magnetic film is a thin film of a metal having high magnetic permeability.
Fully driven speaker described in (1). 9. The high-permeability metal is permalloy.
The speaker according to claim 8, wherein: 10. The speaker according to claim 1, wherein the plate member is a film of a polymer material.