Patent Translate Powered by EPO and Google Notice This translation is machine-generated. It cannot be guaranteed that it is intelligible, accurate, complete, reliable or fit for specific purposes. Critical decisions, such as commercially relevant or financial decisions, should not be based on machine-translation output. DESCRIPTION JP2009147713 An electromagnetic transducer capable of preventing a diaphragm and a permanent magnet plate from contacting while maintaining a large amplitude of the diaphragm uniformly. A permanent magnet plate (2) and (3) on which a strip-like multipolar magnetization pattern is formed, and a coil pattern (4a) arranged opposite to a surface of the permanent magnet plates (2 and 3) on which the multipolar magnetization pattern is formed The upper metal frame 11 and the lower side that cover and support the vibrating film 4 that is electromagnetically coupled to the permanent magnet plates 2 and 3 and vibrates when a current flows in the coil pattern 4a, and the permanent magnet plates 2 and 3 and the vibrating film 4 The electromagnetic transducer 1 having the metal frame 12 is provided with the sponge edge 5 for sandwiching and supporting the outer peripheral portion of the vibrating membrane 4. [Selected figure] Figure 1 Electromagnetic converter [0001] The present invention relates to an electromagnetic transducer which has a coil pattern on the surface of a diaphragm and reproduces sound from an audio signal. [0002] Various techniques have been proposed for an electromagnetic transducer in which a permanent magnet plate and a vibrating membrane are combined. 03-05-2019 1 For example, the electromagnetic converter of Patent Document 1 includes a permanent magnet plate, a vibrating membrane disposed to face the permanent magnet plate, and a buffer member disposed between the permanent magnet plate and the vibrating membrane. There is. The permanent magnet plate has a multi-pole magnetization pattern in which strip-like different magnetic poles are alternately formed at regular intervals. In the vibrating film, a coil formed of a meander-shaped conductor pattern is formed on the entire surface at a position facing the socalled neutral zone of magnetization in the gap between different magnetic poles of permanent magnet plates. When current (audio signal) flows in the coil of the diaphragm, the coil and the multipolar magnetization pattern of the permanent magnet plate are electromagnetically coupled, and audio vibration is generated in the diaphragm according to the law of Fleming. The permanent magnet plate, the diaphragm and the buffer member are covered with a metal frame and attached to the speaker housing. [0003] JP-A-9-331596 [0004] Since the conventional electromagnetic transducer is configured as described above, it is necessary to fix and fix a part of the vibrating membrane to the metal frame, and there is a problem that the amplitude of the vibrating membrane is restricted and it is difficult to make large amplitude. In addition, when a part of the diaphragm is attached to the metal frame, the diaphragm vibrates unevenly when it is oscillated with a large amplitude, and the diaphragm and the permanent magnet plate come into contact with each other to generate noise. The [0005] The present invention has been made to solve the above-described problems. Even when the amplitude of the vibrating membrane becomes large, the amplitude is kept uniform and the vibrating membrane and the permanent magnet plate are in contact with each other. It is an object of the present invention to obtain an electromagnetic converter capable of preventing the [0006] The electromagnetic converter according to the present invention has a permanent magnet plate 03-05-2019 2 on which a strip-shaped multipolar magnetization pattern is formed, and a coil pattern disposed opposite to the surface on which the multipolar magnetization pattern is formed in the permanent magnet plate, An electromagnetic transducer comprising: a vibrating film electromagnetically coupled to the permanent magnet plate and vibrating when a current flows in a coil pattern; and a frame covering and supporting the permanent magnet plate and the vibrating film, the vibrating film And a buffer member for sandwiching and supporting the outer peripheral portion of [0007] According to the present invention, since the shock absorbing member for sandwiching and supporting the outer peripheral portion of the vibrating membrane is provided, it is possible to make the vibrating membrane have a large amplitude uniformly by the expansion and contraction of the shock absorbing member, and the vibrating membrane and the permanent magnet plate It is possible to prevent contact and generation of noise. [0008] Embodiment 1 FIG. 1 is an exploded perspective view showing a configuration of an electromagnetic converter according to Embodiment 1 of the present invention, and FIG. 2 is a cross-sectional view of the electromagnetic converter of FIG. The permanent magnet plates 2 and 3 of the electromagnetic converter 1 shown in FIG. 1 have strip-like multipolar magnetization patterns (parallel stripes of alternating N poles and S poles appearing on the surface facing the vibrating film 4) A magnetized pattern is formed. In the vibrating film 4, a coil pattern 4a consisting of a meander-shaped conductive wire pattern is printed on a thin and flexible film 4b. The linear portion of the coil pattern 4a extending in the longitudinal direction of the rectangular diaphragm 4 is a position corresponding to a neutral zone that is approximately halfway between the N pole and the S pole of the upper permanent magnet plate 2 and the lower permanent magnet plate 3 Provided in When a current flows in the coil pattern 4 a of the vibrating membrane 4, the permanent magnet plates 2 and 3 are electromagnetically coupled to vibrate in the thickness direction of the electromagnetic converter 1. 03-05-2019 3 [0009] The sponge edge (buffer member) 5 has a rectangular frame shape capable of holding the outer peripheral portion of the vibrating membrane 4 and is made of, for example, an elastic member such as urethane foam. As shown in FIG. 2, the pair of sponge edges 5 is disposed between the upper metal frame 11 in which the upper permanent magnet plate 2 is disposed and the lower metal frame 12 in which the lower permanent magnet plate 3 is disposed. Since the film 4 is held, a constant gap can be provided between the upper permanent magnet plate 2 and the vibrating film 4 and between the lower permanent magnet plate 3 and the vibrating film 4. Thereby, even when the diaphragm 4 vibrates, generation of noise due to collision between the upper permanent magnet plate 2 and the diaphragm 4 or the lower permanent magnet plate 3 and the diaphragm 4 is prevented. Can. [0010] Furthermore, a plurality of sponge cushions (second buffer members) 6 are disposed in the vicinity of the center of the vibrating membrane 4 with the vibrating membrane 4 interposed therebetween, and the sponge cushion 6 pair is an upper permanent magnet plate 2 and a lower permanent Hold with the magnet plate 3. The sponge cushion 6 is made of, for example, an elastic member such as urethane foam. Further, the arrangement position and the arrangement number of the sponge cushions 6 can be set arbitrarily. By interposing the sponge cushion 6 between the upper permanent magnet plate 2 and the vibrating membrane 4 and between the lower permanent magnet plate 3, nonuniform displacement of the vibrating membrane 4 can be suppressed. [0011] An upper metal on which a pair of sponge edges 5 are disposed so as to sandwich the outer peripheral portion of the vibrating membrane 4 and a plurality of sponge cushions 6 are disposed near the center of the vibrating membrane 4 and the upper permanent magnet plate 2 is disposed. The metal frame (frame) 10 is configured by sandwiching and bonding the frame (frame) 11 and the lower metal frame (frame) 12 in which the lower permanent magnet plate 3 is disposed. A plurality of radiation sound holes 11 a and 12 a are formed on the surface of the vibrating film 4 of the upper metal frame 11 and the lower metal frame 12 facing the coil pattern 03-05-2019 4 4 a. [0012] Next, the operation of the electromagnetic converter 1 will be described. Since the vibrating film 4 is disposed opposite to the surface on which the multipolar magnetization pattern is formed in the permanent magnet plates 2 and 3, when a current as an audio signal flows through the coil pattern 4a formed on the surface, the coil pattern 4a and the multipolar magnetization pattern of the permanent magnet plates 2 and 3 are electromagnetically coupled, and audio vibration is generated in the vibrating film 4 according to Fleming's law. Sound waves generated by the audio vibration are emitted to the outside through the emission sound holes 11a and 12a, and audio reproduction is performed. [0013] Next, displacement of the diaphragm of the electromagnetic converter according to the first embodiment will be described. When the vibrating membrane 4 vibrates, the sponge edge 5 for holding the vibrating membrane 4 is also extended and contracted to be displaced, whereby the amplitude of the vibrating membrane 4 is allowed. On the other hand, when the amount of compression of the sponge edge 5 increases, a restoring force for returning the sponge edge 5 to the original shape is generated, and the vibration film 4 is further suppressed from being oscillated. As a result, the vibrating membrane 4 can be prevented from coming into contact with the permanent magnet plates 2 and 3, and generation of abnormal noise can be prevented. [0014] FIG. 3 is a view showing another example of the sponge edge of the electromagnetic transducer in accordance with the first embodiment of the present invention. Another embodiment of the sponge edge 5 will be described with reference to FIG. FIG. 3A shows a configuration in which the pair of sponge edges 5 is provided to sandwich and support the outer peripheral portion of the vibrating membrane 4 over the entire periphery as described above. On the other hand, FIG. 3 (b) shows a configuration in which a pair of sponge edges 5 is provided to sandwich and support only two opposing sides of the rectangular vibrating film 4 in the short side direction. Further, FIG. 3C shows a configuration in which a pair of sponge edges 5 is provided which sandwiches and supports only two opposing sides in the longitudinal direction of the rectangular 03-05-2019 5 diaphragm 4. Further, FIG. 3D shows a configuration in which a pair of sponge edges 5 for holding and supporting the four corners of the vibrating membrane 4 is provided. [0015] As described above, according to the first embodiment, the sponge edge pair is disposed between the upper metal frame on which the upper permanent magnet plate is disposed and the lower metal frame on which the lower permanent magnet plate is disposed to vibrate Since the membrane is configured to be held, the sponge edge is also displaced at the same time as the vibrating membrane vibrates, and the amplitude of the vibrating membrane can be allowed within a certain range. As a result, it is possible to suppress the generation of noise due to the vibrating film coming into contact with the permanent magnet plate. [0016] Further, according to the first embodiment, a plurality of sponge cushions are disposed in the vicinity of the center of the vibrating film via the vibrating film, and the upper permanent magnet plate and the lower permanent magnet plate sandwich the sponge cushions. Because of this, it is possible to suppress uneven displacement of the vibrating membrane. [0017] It is a disassembled perspective view which shows the structure of the electromagnetic converter which concerns on Embodiment 1 of this invention. It is the sectional view on the AA line in FIG. It is a figure which shows the example of arrangement ¦ positioning of the sponge edge of the electromagnetic transducer concerning Embodiment 1 of this invention. Explanation of sign [0018] DESCRIPTION OF SYMBOLS 1 electromagnetic converter, 2, 3 permanent magnet board, 4 vibrating membrane, 4a coil pattern, 4b resin film, 5 sponge edge, 6 sponge cushion, 10 metal 03-05-2019 6 frame, 11 upper metal frame, 12 lower metal frame, 11a, 12a Sound emission hole. 03-05-2019 7
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