KR100310520B1 - Flat Electromagnetic Induction Converter - Google Patents

Abstract

The electroconductor diaphragm 110 has an electrical conductor layer 221 positioned between two insulating layers 220 and 222 of flexible, electrically insulating material attached to each other to protect the diaphragm with a conductor pattern.

An electric current flows through the conductor to generate an electromagnet around the conductor which interacts with the electromagnet to generate a mechanical displacement of the diaphragm that generates an audible signal.

Non-ferrous supports are used to support the diaphragm.

It is used to generate an electromagnetic field with a magnet.

The magnet is attached to the cross arm of the nonferrous support.

Description

[Name of invention]

Flat Electromagnetic Inductive Converter

[Background of invention]

The present invention relates to a plate type electromagnetic induction transducer capable of converting an electrical signal into movement of a diaphragm. In addition, the transducer may convert the movement of the diaphragm into an electrical signal. Such transducers can be used in speakers, headphones, microphones, or other devices having similar characteristics.

A description of the advantages and disadvantages of flat panel electromagnetic induction speakers and a description of the state of the art are described in Thigpen, US Patent No. 4,387,838, "Electromagnetic Transducer of Improved Efficiency."

The Tig Pen also discloses an electromagnetic inductive transducer in which a conductive diaphragm is disposed between two sets of magnetic assemblies. The magnet inside the assembly is attached inside an elongated U-shaped channel made of ferrous material. This steel frame makes it difficult to assemble a large and powerful magnet in the frame. In addition, the conductive element is fixed to the outside of the diaphragm. As a result, the conductor part may be exposed to damage from the outside, and there is a risk of causing a shock to a person who accidentally contacts the diaphragm.

[Overview of invention]

According to a first aspect of the present invention, an electromagnetic induction transducer of the present invention comprises a means for generating a flexible diaphragm, an electromagnetic field having at least one magnet and in which the diaphragm is placed, and the diaphragm and the electromagnetic field generating means. Non-ferrous support means for supporting the. The diaphragm comprises a first insulating layer made of a flexible electrical insulating material, a second insulating layer made of a flexible electrical insulating material, and a conductor pattern disposed between the first insulating layer and the second insulating layer.

According to a second aspect of the invention, the first insulating layer and the second insulating layer of the electromagnetic inductive transducer of the present invention are formed of an electrical insulating material in the form of a polymer.

According to a third aspect of the present invention, the first insulating layer and the second insulating layer of the electromagnetic inductive transducer of the present invention are formed of Kapton or Mylar.

According to a fourth aspect of the invention, the electromagnetic inductive transducer of the invention is configured to operate as an audio speaker.

According to a fifth aspect of the invention, the electromagnetic inductive transducer of the invention is configured to operate as a microphone.

According to a sixth aspect of the invention, the electromagnetic inductive transducer of the invention is configured to operate as an antenna.

According to a seventh aspect of the present invention, the electromagnetic induction transducer of the present invention further comprises a plurality of insulating layers and a plurality of conductive layers inside the flexible diaphragm, wherein at least one insulating layer is provided between each conductive layer. And no conductive layer material is present on the surface of the diaphragm.

According to an eighth aspect of the present invention, the nonferrous support means of the electromagnetic inductive transducer of the present invention includes an integrally formed block made of nonferrous material.

According to a ninth aspect of the present invention, the conductive layer of the electromagnetic induction transducer of the present invention includes a plurality of coils.

According to a tenth aspect of the present invention, a plurality of coils of the electromagnetic induction transducer of the present invention are connected in parallel to a plurality of signal sources.

According to an eleventh aspect of the present invention, two or more coils of the plurality of coils of the electromagnetic induction transducer of the present invention are configured to be optimized for different frequency response ranges.

According to a twelfth aspect of the present invention, a method of constructing an electromagnetic induction transducer of the present invention includes selecting a first insulating layer of a flexible electrical insulating material, and a conductor layer having a conductor pattern on one surface of the first insulating layer. Forming a second insulating layer such that the conductor layer is disposed between the first insulating layer and the second insulating layer and no conductive layer material is present on the surface of the diaphragm; Arranging the diaphragm in a magnetic field generated by the magnet, and attaching the diaphragm and the at least one magnet to a nonferrous support means.

According to a thirteenth aspect of the present invention, the conductor layer in the method of constructing the electromagnetic induction transducer of the present invention is formed by printing a conductor pattern on the first insulating layer.

According to a fourteenth aspect of the present invention, at least one magnet in the construction method of the electromagnetic induction transducer of the present invention is charged after being inserted into the support means of the nonferrous material.

According to a fifteenth aspect of the present invention, at least one magnet in the construction method of the electromagnetic induction transducer of the present invention is charged by a solenoid powered by discharge of a capacitor bank.

The electromagnetic induction transducer according to the present invention improves the diaphragm of a conventional flat electromagnetic induction transducer by further providing a layer of insulating material on the conductor portion. This layer protects the conductor against oxidation or other environmental damage, allowing the transducer to operate in a wide range of environments, such as high wet or corrosive environments. In addition, such an insulating layer protects the conductor portion from mechanical damage such as abrasion and prevents breakage of the circuit inside the conductive pattern. In addition, an additional layer of such insulating material can prevent the conductor portion from contacting the magnet assembly or other conductive parts of the transducer, thereby eliminating the risk of shock, which may be reducing the likelihood of a short circuit.

Moreover, the insulating layer may comprise a plurality of layers. These multilayers can be made of different materials. Thus, the resonance frequency of the diaphragm can be controlled. Moreover, different regions of the diaphragm may have different resonant frequencies so that any frequency response peak is removed or appears less. Likewise, an insulating layer can be used to minimize the effect of atmospheric temperature changes on the diaphragm by selecting an insulating material having an appropriate temperature coefficient.

In addition, by providing an insulating layer on the conductor portion, the coil made of a conductor on the diaphragm can have a plurality of conductor portions not only in the plane of the diaphragm but also perpendicular to the plane of the diaphragm. This stacking of coils provides more conductors inside the transducer's magnetic field, ie the electrostatic magnetic field, resulting in increased efficiency.

In addition, the electromagnetic induction transducer according to the present invention provides an improved means for generating a magnetic field in which the diaphragm is located. A non-ferrous support is used for the magnet. Such a nonferrous support does not distort the magnetic field, and when an insulating plastic is used as the nonferrous support, it is possible to further prevent a short circuit to the conductor portion on the diaphragm. This non-ferrous support also protects the magnet from the surrounding environment. The support may be a crossarm to which the magnet is attached, or a frame or block supporting the magnet.

The magnet assembly can be manufactured using new techniques that eliminate the difficulties associated with assembling rigid structures with strong permanent magnets. These magnets generate a strong repulsive force between adjacent magnets on the same side of the diaphragm, and generate a strong attraction force between the magnets on the opposite side of the diaphragm. This assembly technique allows a precisely aligned magnet structure to be obtained, thereby improving the linearity and efficiency of the transducer.

[Brief Description of Drawings]

1 shows a transducer according to an embodiment of the invention seen from the front.

2 is a cross-sectional view of the transducer according to the cutting point shown in FIG.

2A is a detailed cross-sectional view of the diaphragm.

3 shows an example of a means for supporting a magnet of a transducer.

4 shows another magnet support.

5 shows an example of a conductor pattern on the diaphragm.

6 shows another example of the arrangement of the conductor portion inside the diaphragm allowing two or more conductor layers.

FIG. 7 is a cutaway view at the point indicated in FIG. 1 showing the manner in which the individual patterns of the conductor portions are connected to an external signal source.

8 is a diagram illustrating a plurality of transducers are connected to form a system.

[Description of Preferred Embodiment]

1 shows an embodiment of a plate type electromagnetic induction transducer showing a state in which the transducer is seen in front. 2 is a cross-sectional view of the transducer along the cutout shown in FIG. Referring to FIG. 1, main components of the electromagnetic induction transducer according to the present embodiment include a multilayer diaphragm 110, a frame 101 supporting the diaphragm 110, and each side surface of the diaphragm 110. Two magnet assemblies located at. The front magnet assembly has a number of elongated permanent magnets 105 supported by the crossarm 102, while the rear magnet assembly has a permanent magnet 106 supported by the crossarm 103. The frame 101 and the front and rear magnet assemblies (i.e., the magnet 105 supported by the crossarm 102 and the magnet 106 supported by the crossarm 103) are as shown in FIG. It is connected by the screw 104 and the spacers (111, 112).

The diaphragm 110 has three layers as shown in FIG. 2A. The conductive layer 221 is surrounded by two electrical insulating layers 220 and 222. The conductive layer 221 has one or more conductor portions (in this embodiment, the conductive layer 221 has a plurality of conductor portions in the form of a coil-see FIG. 5). In operation, the conductive layer 221 is located in the electromagnetic field. As current flows through the conductor portions, magnetic and electrostatic fields are generated around each conductor portion. These magnetic and electrostatic fields interact with the electromagnetic fields around the diaphragm to generate forces that displace the diaphragm toward the front or rear of the transducer, depending on the direction and magnitude of the current flowing through the conductor portion. This mechanical displacement of the diaphragm causes the surrounding air to move, generating an audio signal in accordance with an electrical signal applied to the conductor portion, so that the converter functions as a speaker. Among these transducers, small transducers can be used inside the headphones.

Further, without any change, the transducer of the present embodiment can be used as a microphone because it can generate an electrical signal based on the displacement of the diaphragm, which can be generated from ambient air by audio vibration. In this case, the movement of the conductor part in the electromagnetic field induces a current flow in the conductor part. These two modes of operation are common to most electromagnetic inductive transducers. For simplicity of the following description, the following only refers to the manner in which the electrical input signal causes the displacement of the diaphragm, but the transducer allows the electrical signal to be generated so that it can be used for other applications (e.g. microphones). It should be noted that

Although this embodiment uses a permanent magnet to generate an electromagnetic field, various other techniques exist. For example, the electromagnetic field may be generated by one or more electromagnets, or may be an electrostatic field generated between two charged plates.

In this embodiment, the electromagnetic field is generated by using the permanent magnets 105 and 106 supported by the cross arms 102 and 103 as shown in FIG. The permanent magnets 105 are arranged to have the same polarity (N pole or S pole) with respect to the diaphragm 110, and the permanent magnets 106 have the opposite polarity as the magnets 105 with respect to the diaphragm 110. Is placed. The center to center spacing between the magnets 105 is constant and equal to the center to center spacing between the magnets 106. In addition, the magnets 105 are alternately arranged with the magnets 106 such that the centerline of each magnet 105 coincides with the center of the space between the two magnets 106 as shown in FIG. Accordingly, a linear pattern is generated with respect to the magnetic flux line between the magnet 105 and the magnet 106.

There are several ways to attach the magnets 105, 106 to the support cross arms 102, 103. In this embodiment, as shown in FIG. 2, a casting 210 made of a magnetic material is attached to a pedestal 211 made of a nonferrous material such as glass fiber or plastic. The magnetic body 210 is adhered to the pedestal 211 by an epoxy resin or other suitable bonding or attaching means. The pedestal 211 is attached to the crossarm 102 or 103 using epoxy resin, plastic rivets or screws or other suitable attachment means. Preferably, the pedestal or other attachment means is made of non-ferrous material to minimize the adverse effect on the linearity of the magnetic field. In addition, non-ferrous materials may also be used for the crossarms 102 and 103 to minimize the undesired coupling of the magnetic field between two adjacent magnets. The non-ferrous crossarm provides a nonferrous support for the magnets 105, 106. The nonferrous support and magnet described above constitute a magnet assembly. Other forms of support for magnets may be used (see Figure 4). As shown in FIG. 3, the magnetic material (eg, magnet) 351 may be sealed in a seal 352 (or other type of seal) that is a rectangular tubular plastic extrusion. Another type of seal or partial seal made of non-ferrous material may be used to seal or partially seal the magnetic material. Such seals (or partial seals) can be distinguished by marking the frequency range of the transducer or by coloring for other information purposes. The nonferrous material used for the support may be any nonferrous material having a structural strength sufficient to support the magnets 105, 106. Glass fibers and plastics are well suited for this purpose.

As shown in FIG. 2, the crossarms 102, 103 are attached to the frame assembly 101 by screws 104. The frame 101 supports the diaphragm 110. The spacers 111 and 112 separate the cross arms 102 and 103 from the frame 101 by a predetermined distance. The distance between the diaphragm 110 and the magnets 105 and 106 may be varied to produce a transducer having different frequency response characteristics. Increasing the distance will cause the transducer to have a low frequency response.

4 shows another means for supporting a magnet. Instead of the crossarm, a forming block 400 made of nonferrous material is used. This block functions as a frame for supporting the magnets. Plastics or other nonferrous materials with suitable strength can be used for this purpose. The block may be manufactured by a variety of methods including, but not limited to, thermal casting, vacuum casting, injection molding or processing. Inside the block 400 there is formed a channel 402 for supporting the magnet 401 and an opening 403 allowing sound generated by the transducer to exit the transducer. Magnet 401 is attached to channel 402 inside block 400 using epoxy resin or other suitable attachment means. The raised portion 404 of the block 400 functions as the spacers 111 and 112 (shown in FIG. 2) to provide a means for attaching to the frame 101 supporting the diaphragm 110. .

Preferred techniques for producing the magnets are not magnetized, either in the form of powder pre-cast into a desired, thin, elongated form when the magnet is attached to the non-ferrous pedestal support, or filled into a compression molded rectangular tube support. Non-Alnico (aluminum, nickel and cobalt) alloy materials. After all parts of the magnet assembly are connected, the entire assembly is placed inside an electromagnet or solenoid powered by the discharge of the capacitor bank. The activation of the electromagnets or solenoids generates large electromagnetic pulses that magnetize the magnetic material of the assembly to the desired polarity.

As shown in FIG. 2A, the diaphragm 110 has a conductive layer 221 positioned between two layers 220 and 222 of an electrically insulating material. The material for the insulating layers 220 and 222 is formed thick enough to prevent damage at the maximum displacement of the diaphragm 110. If the material does not have sufficient flexibility, a strong input signal is required to generate a desired diaphragm movement, resulting in low speaker efficiency. Thin film polyester having a thickness of 1 mil such as Mylar for layer 220, and thin film sound insulation having a thickness of 1 mil such as Kapton Type H for layer 222 (Both manufactured by EI Dupont de Nemours & Co., Inc. of Washington, Delaware) has been found to be desirable. Various thicknesses and a wide range of electrical insulation materials can be used. Different electrical insulation materials may be used to change the frequency response of the transducer. Because of the natural attraction between the Mylar layer and the Kapton layer, no adhesive or other means is required to join the two layers to each other. In order to facilitate the coupling, it is preferable that the insulation materials are different from each other and have attraction to each other. The conductive layer 221 is located between the insulating layer 220 and the insulating layer 222 (sealed in this embodiment).

The conductive layer 221 may be manufactured from a light gauge wire inserted between the insulating layers 220 and 222. The conductive layer may be formed by printing or plating a wire on one of the insulating layers, or by depositing or vacuum depositing a metal coating on one of the insulating layers, and then applying the conductive layer to an undesired portion. It may be formed by removing the metal from the metal by etching (or a similar process). Other methods of forming one or more conductive layers with respect to the conductive layer may be used.

For example, to form one of the insulating layer and the conductive layer, a metal removal method using an aluminum-coated mylar, such as Colortone from Hurd Hastings, may be used. The pattern consisting of the negative pattern of the desired conductor pattern is printed on the paper sheet using a sperm copier or a laser printer. The side of the patterned paper is then placed opposite the aluminum-coated side of the mylar and passed through a heat and compression fusion machine similar to that used in electronic copiers or laser printers. As a result, the bonding of aluminum to the negative pattern occurs because the pattern has a higher temperature. After separating the paper and the mylar, the desired conductor pattern remains in the mylar.

As mentioned above, the diaphragm 110 is supported by the frame 101. As shown in FIG. 2, the frame 101 may be manufactured from the same subframe 201, 202. The diaphragm 110 is inserted between two subframes and uses a double sided adhesive strip 203 to further secure the diaphragm 110 to the subframes 201 and 202.

As shown in FIG. 5, the conductor of the conductive layer 221 of the diaphragm 110 has the form of an independent coil 312. When a voltage is applied between the terminals 301, 302, the current flows so that the vertical direction of the current flowing in the coil region 313 is opposite to the vertical direction of the current flowing in the region 314. The length of the coil 312 is set such that the horizontal conductor regions 310 and 311 lie outside the main magnetic flux region uttered by the magnets 105 and 106.

The width of each coil 312 is equal to the spacing between the centers of the magnets 105 (this corresponds to the spacing between the centers of the magnets 106 as described above). The diaphragm 110 is disposed inside the frame 101 such that the center of each coil 312 coincides with the center of each of the front magnets 105. The number of vertical conductors in the regions 313 and 314 of the coil 312 depends on the width of the conductor. The smaller the conductor width, the more conductors can be placed in the region, resulting in an increase in impedance for the coil and an increase in force between the coil and the magnet, thereby enhancing the efficiency of acoustic generation.

FIG. 6 shows a state in which a plurality of conductive layers are formed by stacking diaphragms in plural layers. FIG. 6 shows an embodiment with three conductive layers 605, 606, 607 embedded inside the electrical insulation layers 601, 602, 603, 604. By using a plurality of conductive layers as shown in FIG. 6, more vertical conductors can be arranged inside the electromagnetic field, thereby improving the efficiency of the converter. The three conductive layers shown in FIG. 6 are merely to illustrate that a plurality of conductive layers can be formed according to the present invention, and are not illustrated to limit the scope of the present invention to a specific number of conductive layers. As shown in FIG. 5, each coil has two terminals 301, 302. 7 shows one possible way of connecting these coils together to a signal source. The double-sided printed circuit board 701 provides electrical connections between the conductor strips 702 and 703 on one side thereof and the contacts 301 and 302 on the side of the substrate 701 on the opposite side of the conductor strips 702 and 703. Plated through holes 704 and 705 are provided. The contact 705 is pressed against the coil terminal 301 and the contact 704 is pressed against the coil terminal 302 to provide the necessary electrical connection.

According to the pattern of the strips 702, 703, the coils are connected in series, parallel or other series-parallel configuration. Configuration means such as switches can be used to select different series-parallel configurations so that the user can change the impedance of the transducer to match the signal source.

8 illustrates an example where two or more planar electromagnetic inductive transducers are combined to form a system that can handle greater power, generate more acoustic energy, and provide better frequency response characteristics. It is shown. Each transducer 801 is attached to a frame 802, which is made of a material such as plastic to protect it from environmental adverse effects, or wood to provide a nice appearance for speakers used in home audio systems. And the like.

The individual transducers of the system may be a series circuit providing a system impedance equal to the sum of the impedances of the transducers, a parallel circuit providing a system impedance equal to the impedance of the individual transducers divided by the number of transducers, or an impedance between these two values. It can be connected as a series-parallel circuit providing. At this time, configuration means such as switches can be used to select different series-parallel configurations so that the user can change the impedance of the transducer to match the signal source.

In addition, the individual transducers can be configured to have different frequency response characteristics by using different materials for the diaphragm or by varying the distance between the diaphragm and the magnet. Also, to route the appropriate frequency range from the input signal to the appropriate converter, a frequency selection network such as a cross-over network commonly used in conventional speaker systems may be used. Techniques for connecting a plurality of transducers using a frequency selective network are already known to those skilled in the art. To help identify a transducer with a particular frequency range, the diaphragm of the transducer can be constructed using color coded materials, and the magnet assembly can likewise be constructed of color coded materials.

It is obvious that the configurations described above are merely illustrative of a number of other alternative configurations that constitute applications for the principles of the present invention. Such other arrangements can be readily devised to those skilled in the art without departing from the spirit and scope of the invention.

Claims (15)

(a) (iii) a first insulating layer made of a flexible electrical insulating material, (Ii) a second insulating layer made of a flexible electrical insulating material, (Iii) a flexible diaphragm composed of a conductor pattern disposed between the first insulating layer and the second insulating layer; (b) means for generating an electromagnetic field having at least one magnet and in which the diaphragm lies; (c) non-ferrous support means for supporting the diaphragm and the electromagnetic field generating means. According to claim 1, The first insulating layer and the second insulating layer is an electromagnetic induction transducer, characterized in that formed of an electrical insulating material of a polymer form. The method of claim 2, And the first and second insulating layers are formed of Kapton or Mylar. An electromagnetic inductive transducer according to claim 1 configured to operate as an audio speaker. An electromagnetic inductive transducer according to claim 1 configured to operate as a microphone. An electromagnetic inductive transducer according to claim 1 configured to operate as an antenna. According to claim 1, A plurality of insulating layers, And a plurality of conductive layers in the flexible diaphragm, such that at least one insulating layer exists between each conductive layer and no conductive layer material is present on the surface of the diaphragm. According to claim 1, The nonferrous support means is characterized in that the electromagnetic induction transducer having an integrally formed block made of a nonferrous material. According to claim 1, And the conductive layer comprises a plurality of coils. The method of claim 9, And said plurality of coils are connected in parallel to a plurality of signal sources. The method of claim 10, And at least two coils of the plurality of coils are configured to be optimized for different frequency response ranges. (a) (i) selecting a first insulating layer of flexible electrical insulating material, (ii) disposing a conductor layer having a conductor pattern on one surface of the first insulating layer; (iii) forming a second insulating layer such that the conductor layer is disposed between the first insulating layer and the second insulating layer and no conductive layer material is present on the surface of the diaphragm; (b) placing the diaphragm in a magnetic field generated by one or more magnets, (c) attaching the diaphragm and at least one magnet to a support means of a non-ferrous material. The method of claim 12, And the conductor layer is formed by printing a conductor pattern on the first insulating layer. The method of claim 12, The one or more magnets are inserted into the support means of the non-ferrous material is a configuration method of the electro-inductive converter characterized in that the charge. The method of claim 14, And said at least one magnet is charged by a solenoid powered by a discharge of a capacitor bank.