Vibration generation device

Abstract

To provide a vibration generation device capable of substantially simultaneously generating different vibrations.SOLUTION: The vibration generator B includes a magnetic-circuit unit having a magnetic gap, a coil unit, a first drive unit 300a, and a second drive unit 300b. The coil unit includes a bobbin, a first coil 220, and a second coil 230 connected in series to the first coil 220. A first coil part 223 of the first coil 220 and a second coil part 233 of the second coil 230 are wound around the bobbin and arranged in the magnetic gap. The first drive unit 300a can apply a first electric signal to the first coil 220 and the second coil 230, and the second drive unit 300b can apply a second electric signal to the second coil 230.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a vibration generating device. [Background technology]

[0002] A conventional speaker is described in Patent Document 1. This conventional speaker includes a cylindrical frame, a vibration weight unit, a vibration coil, and an acoustic unit.

[0003] The frame has a ring-shaped upper end and a ring-shaped lower end.

[0004] The vibration weight unit has a vibration spring, a yoke, a rivet shaft, a substantially cylindrical central magnet, a substantially cylindrical outer magnet, a substantially circular central top plate, and a substantially circular outer top plate. The vibration spring has a substantially circular inner peripheral edge and a substantially circular outer peripheral edge. The outer peripheral edge of the vibration spring is supported at the lower end of the frame. The yoke is fixed to the inner peripheral edge of the vibration plate with a rivet shaft. The central magnet is stacked on the central portion of the yoke and arranged around the rivet shaft. The outer magnet is stacked on the outer peripheral portion of the yoke and arranged around the central magnet. The central top plate is placed on the central magnet. The outer top plate is placed on the outer magnet. A magnetic gap is formed between the central magnet and the central top plate and the outer magnet and the outer top plate.

[0005] The vibration coil is supported on the upper end of the frame via a support and is disposed within the magnetic gap, and when a first electric signal is input to the vibration coil, the vibration mass unit vibrates, generating the vibration.

[0006] The acoustic unit includes an acoustic plate and an acoustic coil. The acoustic plate is supported on the upper end of the frame together with a support. The acoustic coil is fixed to the acoustic plate and disposed within the magnetic gap. When a second electric signal is input to the acoustic coil, the acoustic unit vibrates and generates an acoustic signal. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Special Publication No. 2009-543421 Summary of the Invention [Problem to be solved by the invention]

[0008] In the conventional speaker described above, if the first electric signal is input to the vibration coil and the second electric signal is input to the acoustic coil at the same time, vibrations of the vibration weight unit and the acoustic unit can be generated simultaneously.

[0009] However, since the vibration weight unit is simply vibrated by inputting the first electric signal to the vibration coil, it is not possible to make the vibration unit generate different vibrations substantially simultaneously.

[0010] The present invention provides a vibration generating device that can generate different vibrations substantially simultaneously. [Means for solving the problem]

[0011] A vibration generating device according to one aspect of the present invention includes a magnetic circuit unit having a magnetic gap, a coil unit, a first driving section, and a second driving section.

[0012] The coil unit has a bobbin, a first coil, and a second coil connected in series to the first coil. The first coil has a first starting end, a first ending end connected to the second coil, and a first coil portion. The first coil portion is wound around the bobbin and disposed within the magnetic gap. The second coil has a second starting end, a second ending end, and a second coil portion. The second coil portion is wound around the bobbin and disposed within the magnetic gap. The axial direction of the first coil and the second coil is a first direction.

[0013] The first driver is electrically connected to the first starting end and is configured to apply a first electrical signal to the first coil and the second coil, and the second driver is electrically connected to the second starting end and is configured to apply a second electrical signal to the second coil.

[0014] When a first electric signal is applied to the first coil and the second coil, the coil unit moves back and forth relative to the magnetic circuit unit in a first direction in response to the first electric signal, and when a second electric signal is applied to the second coil, the coil unit moves back and forth relative to the magnetic circuit unit in the first direction in response to the second electric signal. [Effects of the Invention]

[0015] In the vibration generating device of the above aspect, the first driving unit applies a first electric signal to the first coil and the second coil, thereby causing the coil unit to reciprocate relative to the magnetic circuit unit in response to the first electric signal, thereby vibrating the vibration system of the vibration generating device. Furthermore, the second driving unit applies a second electric signal to the second coil, thereby causing the coil unit to reciprocate relative to the magnetic circuit unit in response to the second electric signal, thereby vibrating the vibration system of the vibration generating device. Therefore, by applying the second electric signal to the second coil at approximately the same time as the first driving unit applies the first electric signal to the first and second coils connected in series, different vibrations can be generated approximately simultaneously in the vibration system of the vibration generating device.

[0016] Furthermore, by having the second driving unit apply a second electrical signal to the second coil at a timing different from the timing at which the first driving unit applies a first electrical signal to the first coil and second coil connected in series, it is possible to cause the vibration system of the vibration generating device to generate vibrations corresponding to the first electrical signal and vibrations corresponding to the second electrical signal at different timings.

[0017] When a first electrical signal is applied to the first and second coils connected in series, the DC resistance is the sum of the DC resistance of the first coil and the DC resistance of the second coil, and the length is the sum of the lengths of the first and second coils. On the other hand, when a second electrical signal is applied to the second coil, the DC resistance is the DC resistance of the second coil, and the length is the length of the second coil. There is no difference (they are the same) between the mechanical resonance sharpness (Qms) of the first and second coils connected in series and the mechanical resonance sharpness (Qms) of the second coil, but the electrical resonance sharpness (Qes) of the second coil is higher than the electrical resonance sharpness (Qes) of the first and second coils connected in series, and the total resonance sharpness (Qts) of the second coil is higher than the total resonance sharpness (Qts) of the first and second coils connected in series. Generally, when the total resonance sharpness (Qts) of a coil is high, the coil has a sharper resonance peak, and vibrations occurring around the resonance frequency (near Fo) are emphasized. Therefore, by applying a first electrical signal having a high frequency to a first coil and a second coil connected in series and having a low total resonance sharpness (Qts), vibrations corresponding to the first electrical signal can be suitably generated in the vibration system of the vibration generating device. On the other hand, by applying a second electrical signal having a low frequency to a second coil having a high total resonance sharpness (Qts), vibrations corresponding to the second electrical signal can be suitably generated in the vibration system of the vibration generating device B. However, the frequencies of the first and second electrical signals are set appropriately and are not intended to limit the present invention. [Brief explanation of the drawings]

[0018] [Figure 1A] 1 is a front view of a vibration generating device according to a first embodiment of the present invention. [Figure 1B] FIG. 1 is a plan view of a vibration generating device according to a first embodiment. [Figure 2] 2 is a cross-sectional view of the vibration generating device of the first embodiment taken along line 2-2 in FIG. 1B. [Figure 3] FIG. 2 is a schematic exploded perspective view of the vibration generating device of the first embodiment, in which the first coil and the second coil of the coil unit are omitted. [Figure 4] 2 is an explanatory diagram of a coil unit of the vibration generating device of the first embodiment. FIG. [Figure 5] 1 is a circuit diagram of a vibration generating device according to a first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, several embodiments of the present invention, including Example 1 and its design variations, will be described. Note that the components of the examples and design variations described below can be combined with each other as long as they are not inconsistent. Also, note that the materials, shapes, dimensions, numbers, and arrangements of the components in each aspect of the examples and design variations described below are merely examples, and that any design variation is possible as long as the same functions can be achieved. [Example]

[0020] Hereinafter, a vibration generating device B according to a first embodiment of the present invention and several other embodiments including design variations thereof will be described with reference to Figs. 1A to 5. Figs. 1A to 5 show the vibration generating device B of the first embodiment. Fig. 2 shows the Z-Z' direction. Here, the vibration generating device B will be described as a bone conduction device. Note that bone conduction devices are typically built into headphones, earphones, headsets (headphones or earphones equipped with a microphone), goggles, helmets, etc., but may also be built into other devices.

[0021] The vibration generating device B includes a magnetic circuit unit U1 having a magnetic gap G. The magnetic circuit unit U1 may further include, for example, the following configuration (1) or (2).

[0022] (1) The magnetic circuit unit U1 has a permanent magnet 110, a yoke 120 (yoke), and a pole piece 130. The yoke 120 is a substantially cylindrical (cylindrical or polygonal) tube with a bottom, and has a bottom on the Z-direction side and a substantially cylindrical (cylindrical or polygonal) side wall rising in the Z' direction from the outer circumferential edge of the bottom (see FIG. 2). The permanent magnet 110 is disposed on the bottom of the yoke 120. The pole piece 130 is placed on the permanent magnet 110 and disposed within the yoke 120. A substantially cylindrical (cylindrical or polygonal) magnetic gap G that is open in the Z' direction is formed between the permanent magnet 110 and the pole piece 130 and the side wall of the yoke 120.

[0023] (2) The magnetic circuit unit U1 has a permanent magnet 110, a yoke 120 (yoke), and a pole piece 130. The yoke 120 has a bottom on the Z-direction side and a center pole extending in the Z' direction from the center of the bottom (not shown). The permanent magnet 110 and pole piece 130, which are approximately cylindrical (cylindrical or polygonal cylindrical), are placed in this order on the outer periphery of the bottom and are arranged concentrically around the center pole. A magnetic gap G, which is approximately cylindrical (cylindrical or polygonal cylindrical) and opens in the Z' direction, is formed between the permanent magnet 110, pole piece 130, and the center pole of the yoke 120.

[0024] The vibration generating device B further includes a coil unit U2. The coil unit U2 includes a substantially cylindrical bobbin 210, a first coil 220, and a second coil 230 connected in series to the first coil 220. The Z-Z' direction is the axial direction of the first coil 220 and the second coil 230. In FIG. 3, the first coil 220 and the second coil 230 are omitted from illustration. In FIG. 4, for convenience of illustration, the bobbin 210 is shown with a solid line, the first coil 220 with a dashed line, and the second coil 230 with a dashed line. In addition, in order to distinguish the bobbin 210 from the first coil 220 and the second coil 230, the diameter of the bobbin 210 is shown as being different from the diameters of the first coil 220 and the second coil 230, but it should be noted that this is not realistic.

[0025] The bobbin 210 has a first cylindrical portion having a generally cylindrical shape and a second cylindrical portion having a generally cylindrical shape located on the Z'-direction side of the first cylindrical portion.

[0026] The first coil 220 has a first starting end 221, a first terminal end 222, and a first coil portion 223. The second coil 230 has a second starting end 231, a second terminal end 232, and a second coil portion 233.

[0027] The first end 222 of the first coil 220 is connected to the second coil 230. More specifically, it is connected between the second start end 231 and the second coil portion 233 of the second coil 230. The second end 232 of the second coil 230 is connected to ground.

[0028] The first coil portion 223 of the first coil 220 is wound around the bobbin 210 and is disposed within the magnetic gap G having the configuration (1) or (2) above. The second coil portion 233 of the second coil 230 is wound around the bobbin 210 and is disposed within the magnetic gap G of the magnetic circuit unit U1 having the configuration (1) or (2) above.

[0029] For example, the first coil portion 223 and the second coil portion 233 may be wound around the first cylindrical portion of the bobbin 210 so that the coil wires thereof alternate (see FIG. 4), and may be disposed together with the first cylindrical portion of the bobbin 210 in the magnetic gap G of the magnetic circuit unit U1 having the configuration (1) or (2) above (see FIG. 2). Alternatively, the first coil portion 223 may be wound around the first cylindrical portion of the bobbin 210 (not shown), and the second coil portion 233 may be wound around the first cylindrical portion of the bobbin 210 so that it is positioned on the Z-direction side or Z'-direction side relative to the first coil portion 223, and the first coil portion 223 and the second coil portion 233 may be disposed together with the first cylindrical portion of the bobbin 210 in the magnetic gap G of the magnetic circuit unit U1 having the configuration (1) or (2) above (not shown).

[0030] The DC resistance (R) of the first coil 220 is approximately the same as the DC resistance (R) of the second coil 230. The length (L) of the first coil 220 is approximately the same as the length (L) of the second coil 230.

[0031] The vibration generating device B further includes a first driving section 300a and a second driving section 300b.

[0032] The first driving unit 300 a is electrically connected to the first starting end 221 of the first coil 220 and is configured to be able to apply a first electrical signal to the first coil 220 and the second coil 230 .

[0033] The first driver 300a includes, for example, a first amplifier circuit 310a and a first filter 320a. The first amplifier circuit 310a includes an operational amplifier 311a and a negative feedback resistor 312a. The operational amplifier 311a includes a non-inverting input terminal, an inverting input terminal, and an output terminal. An electrical signal is input to the inverting input terminal of the operational amplifier 311a. The non-inverting input terminal of the operational amplifier 311a is connected to ground. The negative feedback resistor 312a is connected between the output terminal and the inverting input terminal of the operational amplifier 311a. The first filter 320a is connected between the output terminal of the operational amplifier 311a and the first starting end 221 of the first coil 220. The first filter 320a is, for example, an RC series circuit and includes a resistor 321a and a capacitor 322a. The electrical signal input to the inverting input terminal of the operational amplifier 311a is amplified by the first amplifier circuit 310a, and signals of a predetermined frequency and / or noise, etc. are removed from the amplified electrical signal by the first filter 320a, thereby generating a first electrical signal of constant voltage, and this first electrical signal is applied to the first coil 220 and the second coil 230.

[0034] The first filter 320a can be omitted. In this case, the electrical signal input to the inverting input terminal of the operational amplifier 311a is amplified by the first amplifier circuit 310a to generate a first electrical signal of a constant voltage, which is then applied to the first coil 220 and the second coil 230.

[0035] The second driving section 300b is electrically connected to the second starting end 231 of the second coil 230 and is configured to be able to apply a second electrical signal to the second coil 230.

[0036] The second driver 300b includes, for example, a second amplifier circuit 310b and a second filter 320b. The second amplifier circuit 310b includes an operational amplifier 311b and a negative feedback resistor 312b. The operational amplifier 311b includes a non-inverting input terminal, an inverting input terminal, and an output terminal. An electrical signal is input to the inverting input terminal of the operational amplifier 311b. The non-inverting input terminal of the operational amplifier 311b is connected to ground. The negative feedback resistor 312b is connected between the output terminal and the inverting input terminal of the operational amplifier 311b. The second filter 320b is connected between the output terminal of the operational amplifier 311b and the second starting end 231 of the second coil 230. The second filter 320b is, for example, an RC series circuit and includes a resistor 321b and a capacitor 322b. The electrical signal input to the inverting input terminal of the operational amplifier 311b is amplified by the second amplifier circuit 310b, and signals of a predetermined frequency and / or noise, etc. are removed from the amplified electrical signal by the second filter 320b, thereby generating a second electrical signal of constant voltage, and the second electrical signal is applied to the second coil 230.

[0037] The second filter 320b can be omitted. In this case, the electrical signal input to the inverting input terminal of the operational amplifier 311b is amplified by the second amplifier circuit 310b to generate a second electrical signal of a constant voltage, and the second electrical signal is applied to the second coil 230.

[0038] When a first electric signal is applied to the first coil portion 223 and the second coil portion 233, an electromagnetic force (F) is generated in the first coil portion 223 and the second coil portion 233 due to the interaction between the first electric signal and the magnetic flux in the magnetic gap G. This electromagnetic force (F) acts on the first coil portion 223 and the second coil portion 233 as a driving force in the Z-Z' direction, causing the coil unit U2 to reciprocate in the Z-Z' direction relative to the magnetic circuit unit U1 in response to the first electric signal. That is, the magnetic circuit unit U1 reciprocates in the Z-Z' direction relative to the coil unit U2, or the coil unit U2 reciprocates in the Z-Z' direction relative to the magnetic circuit unit U1.

[0039] When a second electric signal is applied to the second coil portion 233, an electromagnetic force (F) is generated in the second coil portion 233 due to the interaction between the second electric signal and the magnetic flux in the magnetic gap G. This electromagnetic force (F) acts on the second coil portion 233 as a driving force in the Z-Z' direction, causing the coil unit U2 to reciprocate in the Z-Z' direction relative to the magnetic circuit unit U1 in response to the second electric signal. That is, the magnetic circuit unit U1 reciprocates in the Z-Z' direction relative to the coil unit U2, or the coil unit U2 reciprocates in the Z-Z' direction relative to the magnetic circuit unit U1.

[0040] The application of the first electrical signal to the first coil 220 and the second coil 230 by the first driving unit 300a and the application of the second electrical signal to the second coil 230 by the second driving unit 300b may be performed at the same timing or at different timings.

[0041] The vibration generator B may further include a first damper 400a that is elastically deformable in the Z-Z' direction. The first damper 400a is disposed in the coil unit U2 on the Z' direction side (one side in the first direction) of the magnetic circuit unit U1. The first damper 400a is fixed to the magnetic circuit unit U1 and also to the coil unit U2.

[0042] The first damper 400a may be, for example, approximately disk-shaped or approximately polygonal plate-shaped, and may have a first fixed portion 410a fixed to the magnetic circuit unit U1, a second fixed portion 420a fixed to the coil unit U2, and one or more connecting portions 430a connecting the first fixed portion 410a and the second fixed portion 420a.

[0043] When the magnetic circuit unit U1 has the above configuration (1), the first fixed portion 410a of the first damper 400a is fixed to the Z'-direction surface of the pole piece 130 of the magnetic circuit unit U1 via an intervening member A made of synthetic resin or the like, and the second fixed portion 420a of the first damper 400a is fixed to the second cylindrical portion of the bobbin 210 of the coil unit U2 (see FIGS. 1A to 3). Note that the first fixed portion 410a of the first damper 400a may be fixed directly to the Z'-direction surface of the pole piece 130 of the magnetic circuit unit U1.

[0044] When the magnetic circuit unit U1 has the above configuration (2), the first fixed portion 410a of the first damper 400a is fixed to the center pole of the yoke 120 of the magnetic circuit unit U1 via an intervening member A or directly, and the second fixed portion 420a of the first damper 400a is fixed to the second cylindrical portion of the bobbin 210 of the coil unit U2 (not shown).

[0045] The vibration generating device B may further include a frame 500 having a substantially tubular shape (cylindrical or polygonal tubular shape). The frame 500 is made of a synthetic resin or the like. The frame 500 fits over the magnetic circuit unit U1 and is fixed to the magnetic circuit unit U1. The frame 500 is disposed around the coil unit U2. The frame 500 has a first tubular portion and a second tubular portion located on the Z'-direction side of the first tubular portion.

[0046] When the magnetic circuit unit U1 has the above configuration (1), the side wall of the yoke 120 of the magnetic circuit unit U1 is fitted into the first cylindrical portion of the frame 500 and is fixed to the first cylindrical portion of the frame 500 (see FIGS. 1A to 2).

[0047] When the magnetic circuit unit U1 has the configuration (2) above, the bottom of the yoke 120 of the magnetic circuit unit U1, the permanent magnet 110, and the pole piece 130 are fitted into the first cylindrical portion of the frame 500 and fixed to the first cylindrical portion of the frame 500 (not shown).

[0048] In either case, the second cylindrical portion of the frame 500 is disposed opposite to the second cylindrical portion of the bobbin 210 of the coil unit U2.

[0049] The vibration generator B may further include a substantially annular second damper 400b elastically deformable in the Z-Z' direction. The second damper 400b is disposed around the coil unit U2 and suspended between the frame 500 and the coil unit U2. The second damper 400b may include, for example, a first fixed portion 410b fixed to the second cylindrical portion of the bobbin 210 of the coil unit U2, a second fixed portion 420b fixed to the second cylindrical portion of the frame 500, and one or more connecting portions 430b connecting the first fixed portion 410b and the second fixed portion 420b.

[0050] When the magnetic circuit unit U1 is configured to reciprocate in the Z-Z' direction relative to the coil unit U2, the vibration generating device B may further include a base 600 and a substrate 700 made of insulating resin or the like. The base 600 has a first portion 610 and a second portion 620. The first portion 610 of the base 600 is fixed to the second cylindrical portion of the bobbin 210 of the coil unit U2. The first portion 610 of the base 600 is located on the Z' direction side relative to the coil unit U2. The second portion 620 of the base 600 extends from the first portion 610 in a direction approximately perpendicular to the Z-Z' direction and is located outward relative to the magnetic circuit unit U1 in the same direction. The base 600 may be omitted.

[0051] The substrate 700 is fixed onto the surface of the second part 620 of the base 600 on the Z direction side. The first driving unit 300a and the second driving unit 300b may be electrically connected to the substrate 700. The first driving unit 300a and the second driving unit 300b may be mounted on the substrate 700. In either case, the first driving unit 300a is electrically connected to the first starting end 221 of the first coil 220 via the substrate 700, and the second driving unit 300b is electrically connected to the second starting end 231 of the second coil 230 via the substrate 700. The substrate 700 may be omitted.

[0052] When the magnetic circuit unit U1 is configured to reciprocate in the ZZ' direction relative to the coil unit U2, the vibration system of the vibration generating device B can have any one of the following configurations (a) to (c).

[0053] (a) When the first damper 400a, the second damper 400b, and the frame 500 are provided, the vibration system of the vibration generator B is composed of the magnetic circuit unit U1, the first damper 400a, the second damper 400b, and the frame 500. When a first electric signal is applied to the first coil portion 223 and the second coil portion 233, the magnetic circuit unit U1 and the frame 500 move back and forth in the Z-Z' direction in response to the first electric signal, and the first damper 400a and the second damper 400b elastically deform in the Z-Z' direction. In this way, the vibration system of the vibration generator B vibrates in response to the first electric signal. When a second electric signal is applied to the second coil portion 233, the magnetic circuit unit U1 and the frame 500 move back and forth in the Z-Z' direction in response to the second electric signal, and the first damper 400a and the second damper 400b elastically deform in the Z-Z' direction. In this way, the vibration system of the vibration generating device B vibrates in response to the second electric signal.

[0054] (b) When the first damper 400a is provided but the second damper 400b and frame 500 are not provided, the vibration system of the vibration generator B is composed of the magnetic circuit unit U1 and the first damper 400a. When a first electric signal is applied to the first coil portion 223 and the second coil portion 233, the magnetic circuit unit U1 moves back and forth in the Z-Z' direction in response to the first electric signal, and the first damper 400a elastically deforms in the Z-Z' direction. In this way, the vibration system of the vibration generator B vibrates in response to the first electric signal. When a second electric signal is applied to the second coil portion 233, the magnetic circuit unit U1 moves back and forth in the Z-Z' direction in response to the second electric signal, and the first damper 400a elastically deforms in the Z-Z' direction. In this way, the vibration system of the vibration generator B vibrates in response to the second electric signal.

[0055] (c) When the second damper 400b and the frame 500 are provided but the first damper 400a is not provided, the vibration system of the vibration generator B is composed of the magnetic circuit unit U1, the second damper 400b, and the frame 500. When a first electric signal is applied to the first coil portion 223 and the second coil portion 233, the magnetic circuit unit U1 and the frame 500 move back and forth in the Z-Z' direction in response to the first electric signal, and the second damper 400b elastically deforms in the Z-Z' direction. In this way, the vibration system of the vibration generator B vibrates in response to the first electric signal. When a second electric signal is applied to the second coil portion 233, the magnetic circuit unit U1 and the frame 500 move back and forth in the Z-Z' direction in response to the second electric signal, and the second damper 400b elastically deforms in the Z-Z' direction. In this way, the vibration system of the vibration generator B vibrates in response to the second electric signal.

[0056] As described above in any one of (a) to (c), the vibration system of the vibration generating device B vibrates, and the magnetic circuit unit U1 repeatedly contacts the transmission target (for example, the skull or the outer ear cartilage) in the Z-Z' direction, whereby the vibration of the vibration system of the vibration generating device B is transmitted to the transmission target. The vibration is transmitted to the cochlea via the transmission target.

[0057] When the coil unit U2 is configured to reciprocate in the Z-Z' direction relative to the magnetic circuit unit U1, the vibration generator B may further include an abutment member (not shown) instead of the base 600. The abutment member is fixed to the second cylindrical portion of the bobbin 210 of the coil unit U2 instead of the base 600. In this case, the vibration system of the vibration generator B can have any of the following configurations (d) to (f).

[0058] (d) When the first damper 400a, the second damper 400b, and the frame 500 are provided, the vibration system of the vibration generator B is composed of the coil unit U2, the contact member, the first damper 400a, and the second damper 400b. When a first electric signal is applied to the first coil section 223 and the second coil section 233, the coil unit U2 and the contact member move back and forth in the Z-Z′ direction in response to the first electric signal, and the first damper 400a and the second damper 400b elastically deform in the Z-Z′ direction. In this way, the vibration system of the vibration generator B vibrates in response to the first electric signal. When a second electric signal is applied to the second coil section 233, the coil unit U2 and the contact member move back and forth in the Z-Z′ direction in response to the second electric signal, and the first damper 400a and the second damper 400b elastically deform in the Z-Z′ direction. In this way, the vibration system of the vibration generator B vibrates in response to the second electric signal.

[0059] (e) When the first damper 400a is provided but the second damper 400b and frame 500 are not, the vibration system of the vibration generator B is composed of the coil unit U2, the abutment member, and the first damper 400a. When a first electric signal is applied to the first coil portion 223 and the second coil portion 233, the coil unit U2 and the abutment member move back and forth in the Z-Z' direction in response to the first electric signal, and the first damper 400a elastically deforms in the Z-Z' direction. In this way, the vibration system of the vibration generator B vibrates in response to the first electric signal. When a second electric signal is applied to the second coil portion 233, the coil unit U2 and the abutment member move back and forth in the Z-Z' direction in response to the second electric signal, and the first damper 400a elastically deforms in the Z-Z' direction. In this way, the vibration system of the vibration generator B vibrates in response to the second electric signal.

[0060] (f) When the second damper 400b and frame 500 are provided but the first damper 400a is not, the vibration system of the vibration generator B is composed of the coil unit U2, the abutment member, and the second damper 400b. When a first electric signal is applied to the first coil portion 223 and the second coil portion 233, the coil unit U2 and the abutment member move back and forth in the Z-Z' direction in response to the first electric signal, and the second damper 400b elastically deforms in the Z-Z' direction. In this way, the vibration system of the vibration generator B vibrates in response to the first electric signal. When a second electric signal is applied to the second coil portion 233, the coil unit U2 and the abutment member move back and forth in the Z-Z' direction in response to the second electric signal, and the second damper 400b elastically deforms in the Z-Z' direction. In this way, the vibration system of the vibration generator B vibrates in response to the second electric signal.

[0061] As described above in any of (d) to (f), the vibration system of the vibration generating device B vibrates, and the contact member repeatedly contacts the transmission target in the Z-Z' direction, thereby transmitting the vibration of the vibration system of the vibration generating device B to the transmission target. The vibration is transmitted to the cochlea via the transmission target. Note that the contact member can be omitted.

[0062] When a first electrical signal of a constant voltage is applied to the first coil 220 and the second coil 230 connected in series, the DC resistance of the first coil 220 and the second coil 230 connected in series is 2R (the sum of the DC resistance of the first coil 220 and the DC resistance of the second coil 230), and the length of the first coil 220 and the second coil 230 connected in series is 2L (the sum of the length of the first coil 220 and the length of the second coil 230). When a second electrical signal with the same input voltage as the first electrical signal is applied to the second coil 230, the DC resistance of the second coil 230 is R, and the length of the second coil 230 is L, as described above.

[0063] In this case, there is no difference (they are the same) between the mechanical resonance sharpness (Qms) of the first coil 220 and the second coil 230 connected in series and the mechanical resonance sharpness (Qms) of the second coil 230. On the other hand, the electrical resonance sharpness (Qes) of the second coil 230 is approximately twice the electrical resonance sharpness (Qes) of the first coil 220 and the second coil 230 connected in series. As a result, the total resonance sharpness (Qts) of the second coil 230 is higher than the total resonance sharpness (Qts) of the first coil 220 and the second coil 230 connected in series.

[0064] There is no difference (they are the same) between the electromagnetic force (F) generated in the first coil portion 223 and the second coil portion 233 when a first electric signal is applied to the first coil 220 and the second coil 230 connected in series, and the electromagnetic force (F) generated in the second coil portion 233 when a second electric signal is applied to the second coil 230. Furthermore, there is no difference (they are the same) between the acceleration of the vibration system of the vibration generating device B when the first electric signal is applied to the first coil 220 and the second coil 230 connected in series, and the acceleration of the vibration system of the vibration generating device B when the second electric signal is applied to the second coil 230.

[0065] In addition, the electrical resonance sharpness (Qes) of the first coil 220 and the second coil 230 connected in series can be calculated by the following formula 2, where 2πFoMo=A in the formula 1 below, since A is considered to be a constant.

[0066]

number

[0067]

number

[0068] On the other hand, as described above, the electric resonance sharpness (Qes) of the second coil 230 is calculated by the following formula 3, since the DC resistance of the second coil 230 is R and the length of the second coil 230 is L.

[0069]

number

[0070] The mechanical resonance sharpness (Qms) of the first coil 220 and second coil 230 connected in series is calculated by the following formula 4. The mechanical resonance sharpness (Qms) of the second coil 230 is also calculated by the following formula 4. Here, Rm is the mechanical resistance, Mo is the vibration system weight, and Fo is the lowest resonance frequency.

[0071]

number

[0072] The total resonance sharpness (Qts) of the first coil 220 and the second coil 230 connected in series, and the total resonance sharpness (Qts) of the second coil 230 are calculated by the following mathematical expression 5.

[0073]

number

[0074] 1A to 2, a comparison was made between CASE (A) and CASE (B) as shown in Table 1 below. CASE (A) is a case where a constant-voltage first electrical signal is applied to the first coil 220 and the second coil 230 connected in series, and the magnetic flux density of the magnetic gap G of the magnetic circuit unit U1, the effective wire length of the first coil 220 and the second coil 230 connected in series, the DC resistance of the first coil 220 and the second coil 230 connected in series, the minimum resonance frequency of the vibration generator B, the weight of the vibration system of the vibration generator B, and the mechanical resistance of the vibration generator B were set as shown in Table 1. CASE (B) is the case where a second electrical signal is applied to the second coil 230 at the same input voltage as the first electrical signal, and the magnetic flux density of the magnetic gap G of the magnetic circuit unit U1, the effective wire length of the second coil 230, the DC resistance of the second coil 230, the minimum resonant frequency of the vibration generating device B, the weight of the vibration system of the vibration generating device B, and the mechanical resistance of the vibration generating device B are set as shown in Table 1.

[0075] As a result, as shown in Table 1, there is no difference (they are the same) between the mechanical resonance sharpness (Qms) value of the first coil 220 and the second coil 230 connected in series and the mechanical resonance sharpness (Qms) value of the second coil 230, but the electrical resonance sharpness (Qes) value of the second coil 230 is approximately twice the electrical resonance sharpness (Qes) value of the first coil 220 and the second coil 230 connected in series, and the overall resonance sharpness (Qts) value of the second coil 230 is higher than the overall resonance sharpness (Qts) value of the first coil 220 and the second coil 230 connected in series.

[0076] [Table 1]

[0077] The vibration generating device B as described above has the following technical features and effects (1) and (2).

[0078] Technical Features and Effects (1) The first driver 300a applies a first electric signal to the first coil 220 and the second coil 230 connected in series, thereby vibrating the vibration system of the vibration generator B in accordance with the first electric signal. The second driver 300b applies a second electric signal to the second coil 230, thereby vibrating the vibration system of the vibration generator B in accordance with the second electric signal. Therefore, different vibrations can be generated in the vibration system of the vibration generator B approximately simultaneously by the second driver 300b applying the second electric signal to the second coil 230 at approximately the same timing as the first driver 300a applies the first electric signal to the first coil 220 and the second coil 230 connected in series.

[0079] Furthermore, by having the second driving unit 300b apply a second electrical signal to the second coil 230 at a timing different from the timing at which the first driving unit 300a applies a first electrical signal to the first coil 220 and the second coil 230 connected in series, it is possible to cause the vibration system of the vibration generating device B to generate vibrations corresponding to the first electrical signal and vibrations corresponding to the second electrical signal at different timings.

[0080] Technical Features and Effects (2) The total resonance sharpness (Qts) value of the second coil 230 is higher than the total resonance sharpness (Qts) value of the first coil 220 and the second coil 230 connected in series. Generally, when the total resonance sharpness (Qts) value of a coil is high, the coil has a sharper resonance peak, and vibrations occurring around the resonance frequency (near Fo) are emphasized. Therefore, by applying a first electrical signal having a high frequency (e.g., 20 Hz to 20 kHz) such as voice or music to the first coil 220 and the second coil 230 connected in series and having a low total resonance sharpness (Qts), vibrations (voice, music, etc.) corresponding to the first electrical signal can be suitably generated in the vibration system of the vibration generating device B. On the other hand, by applying a second electrical signal having a low frequency (e.g., 10 Hz to 100 Hz) such as vibration or deep bass to the second coil 230 having a high overall resonance sharpness (Qts), vibration (vibration, deep bass, etc.) corresponding to the second electrical signal can be suitably generated in the vibration system of the vibration generating device B.

[0081] To repeat, since the value of the total resonance sharpness (Qts) of the second coil 230 is higher than the value of the total resonance sharpness (Qts) of the first coil 220 and the second coil 230 connected in series, even if the second electrical signal is applied to the second coil 230 with the same input voltage as the first electrical signal, the vibration (vibration, deep bass, etc.) generated in response to the second electrical signal by the vibration system of the vibration generating device B can be made larger (emphasized).

[0082] The vibration generating device described above is not limited to the above embodiment, and can be modified in any manner within the scope of the claims.

[0083] The magnetic circuit unit U1 has a magnetic gap G in which the first coil portion 223 and the second coil portion 233 of the coil unit U2 are arranged, and may have any configuration as long as the magnetic circuit unit U1 is configured to move back and forth relative to the magnetic circuit unit U1 in the Z-Z' direction through the interaction between the first electrical signal flowing in the first coil portion 223 and the second coil portion 233 and / or the second electrical signal flowing in the second coil portion 233 and the magnetic flux in the magnetic gap G.

[0084] The DC resistance (R) of the first coil 220 and the DC resistance (R) of the second coil 230 may be different, and the length (L) of the first coil 220 and the length (L) of the second coil 230 may be different. When a first electrical signal is applied to the first coil 220 and the second coil 230 connected in series, the DC resistance is the sum of the DC resistance of the first coil 220 and the DC resistance of the second coil 230, and the length is the sum of the lengths of the first coil 220 and the second coil 230. On the other hand, when a second electrical signal is applied to the second coil 230, the DC resistance is the DC resistance of the second coil 230, and the length is the length of the second coil 230. Even in this case, there is no difference (they are the same) between the mechanical resonance sharpness (Qms) of the first coil 220 and the second coil 230 connected in series and the mechanical resonance sharpness (Qms) of the second coil 230, but the electrical resonance sharpness (Qes) of the second coil 230 is higher than the electrical resonance sharpness (Qes) of the first coil 220 and the second coil 230 connected in series, and the overall resonance sharpness (Qts) of the second coil 230 is higher than the overall resonance sharpness (Qts) of the first coil 220 and the second coil 230 connected in series. Therefore, even with the vibration generating device B designed in this way, the same technical scope and effects as those described above can be obtained.

[0085] The first driving unit 300a may have any configuration as long as it is electrically connected to the first starting end 221 of the first coil 220 and is capable of applying a first electrical signal to the first coil 220 and the second coil 230. The first amplifier circuit 310a of the first driving unit 300a may have any configuration as long as it is electrically connected to the first starting end 221 of the first coil 220 and is capable of amplifying an input electrical signal to generate a first electrical signal and applying the first electrical signal to the first coil 220 and the second coil 230. The first electrical signal is not limited to an electrical signal having a high frequency such as voice or music, and can be set arbitrarily.

[0086] The second driving unit 300b may have any configuration as long as it is electrically connected to the second starting end 231 of the second coil 230 and is capable of applying a second electrical signal to the second coil 230. The second amplifier circuit 310b of the second driving unit 300b may have any configuration as long as it is electrically connected to the second starting end 231 of the second coil 230 and is capable of amplifying an input electrical signal to generate a second electrical signal and applying the second electrical signal to the second coil 230. The second electrical signal is not limited to an electrical signal having a low frequency such as vibration or deep bass, and can be set arbitrarily.

[0087] The vibration system of the vibration generating device B described above may further include a separate member such as a weight.

[0088] The vibration generator B described above is not limited to a bone conduction device. For example, the vibration generator B can also be used as a vibration generator for a haptic device or a speaker. When the vibration generator B is used as a vibration generator for a speaker, for example, the first damper 400a and the base 600 of the vibration generator B described above may be omitted, and the voice coil of the speaker may be disposed inside the coil unit U2 within the magnetic gap G of the magnetic circuit unit U1, and the outer peripheral edge of the diaphragm fixed to the voice coil may be fixed to the frame 500 so as not to interfere with the second damper 400b. In this case, when a third electronic signal is input to the voice coil, the voice coil and the diaphragm fixed thereto vibrate, generating an acoustic signal.

[0089] The transmission target to which the vibration generated by the vibration generating device B is transmitted can be set arbitrarily. [Explanation of symbols]

[0090] B: Vibration generator U1: Magnetic circuit unit G: Magnetic gap 110: Permanent magnet 120: Yoke 130: Pole piece U2: Coil unit 210: bobbin 220: first coil 221: first starting end 222: first ending end 223: first coil section 230: second coil 231: second starting end 232: second ending end 233: second coil section 300a: First driving unit 300b: Second driving unit 400a: First damper 400b: Second damper 500: Frame 600: Bass 700: Circuit board A: Intervening member

Claims

1. a magnetic circuit unit having a magnetic gap; A coil unit, A first drive unit; a second drive unit, the coil unit includes a bobbin, a first coil, and a second coil connected in series to the first coil; the first coil has a first starting end, a first ending end connected to the second coil, and a first coil portion, the first coil portion being wound around the bobbin and disposed within the magnetic gap; the second coil has a second starting end, a second ending end, and a second coil portion, the second coil portion being wound around the bobbin and disposed within the magnetic gap, and an axial direction of the first coil and the second coil being a first direction; the first driving unit is electrically connected to the first starting end and is configured to be able to apply a first electrical signal to the first coil and the second coil; the second driving unit is electrically connected to the second starting end and is configured to be able to apply a second electric signal to the second coil, A vibration generating device in which, when the first electric signal is applied to the first coil and the second coil, the coil unit moves back and forth relative to the magnetic circuit unit in the first direction in response to the first electric signal, and, when the second electric signal is applied to the second coil, the coil unit moves back and forth relative to the magnetic circuit unit in the first direction in response to the second electric signal.

2. 2. The vibration generating device according to claim 1, The DC resistance of the first coil and the DC resistance of the second coil are substantially the same, A vibration generating device, wherein the length of the first coil and the length of the second coil are approximately the same.

3. 2. The vibration generating device according to claim 1, Further comprising a first damper, The first damper is arranged on one side of the magnetic circuit unit in the first direction within the coil unit, and is fixed to the magnetic circuit unit and a vibration generating device fixed to the coil unit.

4. 4. The vibration generating device according to claim 1, a substantially cylindrical frame fitted onto the magnetic circuit unit and arranged around the coil unit; The vibration generating device further includes a substantially annular second damper disposed around the coil unit and suspended from the frame and the coil unit.

5. 2. The vibration generating device according to claim 1, The vibration generating device, wherein the second end of the second coil is connected to ground.

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