JP2008294999A - Speech unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a speech unit that dispenses with speech design according to the shape and size of a device body, and can reduce design working hours and design costs. <P>SOLUTION: The speech unit A has: a speaker SP outputting sound information transmitted from the outside from one surface side and microphones M1, M2 collecting sound to output a sound signal in a module body A20; a speech module A2 forming a rear air space Br surrounded by the inner surface of the module body A20 and the other surface side of the speaker SP; and the device body A1 storing the speech module A2 to form the outer shell of the unit. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a call device used for an interphone or the like.

Conventionally, there is a communication device installed indoors with an interphone system or the like, which includes a speaker that outputs sound from a communication device installed in another place, a microphone that inputs sound transmitted to the other communication device, and the like. Yes. (For example, refer to Patent Document 1).
JP 2007-28543 A

  Calling devices equipped with speakers and microphones, such as voice information transmission devices used indoors and intercom devices for detached houses and apartment buildings, are designed exclusively for users' needs, preferences, and standards. There was a need to do.

  However, since the acoustic characteristics change depending on the acoustic structure such as the speaker position, the microphone position, and the capacity of the rear air chamber on the back side of the speaker, it is necessary to design the telephone call according to these conditions. Therefore, if the shape and size of the device main body that forms the outline of the communication device changes, the speaker position, microphone position, capacity of the back air chamber on the back of the speaker, and the like also change. Design man-hours and design costs were required.

  The present invention has been made in view of the above-mentioned reasons, and its purpose is to provide a communication device that does not need to perform call design according to the shape and size of the device main body, and can reduce design man-hours and design costs. There is to do.

  According to the first aspect of the present invention, a module main body is provided with a speaker that outputs audio information transmitted from the outside from one side, and one or more microphones that collect sound and output audio signals. And a speaker module that forms a rear air chamber surrounded by the other side of the speaker, and a device main body that houses the speech module and forms the outer shell of the device.

  According to the present invention, a desired acoustic characteristic can be obtained simply by incorporating a call module into a device body of various shapes and sizes, so there is no need to perform a call design according to the shape and size of the device body. Design man-hours and design costs can be reduced.

  According to a second aspect of the present invention, in the first aspect, the microphone includes a first microphone and a second microphone disposed at a position farther from the first microphone than the speaker. And an audio processing unit for removing the audio signal of the first microphone from the audio signal of the second microphone and transmitting the same to the outside.

  According to this invention, howling can be prevented by performing a process of reducing the sound emitted by the speaker from the audio signal output from the second microphone by the audio processing unit.

  According to a third aspect of the present invention, in the second aspect, the first microphone faces a diaphragm of the speaker.

  According to the present invention, even if the sound emitted from the speaker has directivity, the sound emitted from the speaker can be easily collected, and the howling prevention effect by the sound processing unit is improved. In addition, the apparatus can be reduced in size.

  According to a fourth aspect of the present invention, in the second or third aspect, the apparatus main body is provided with a plurality of sound holes on the outer surface for allowing the sound output from the speaker to pass, and the center of the sound collecting hole of the second microphone is It is arranged to face the center of the sound hole.

  According to the present invention, since it is not necessary to provide a sound hole dedicated to the second microphone, it is possible to reduce costs and improve design.

  According to a fifth aspect of the present invention, in any one of the first to fourth aspects, a board on which a first connector is mounted is disposed in the apparatus main body, and the call module is electrically and mechanically connected to the first connector. The second connector is provided.

  According to the present invention, since the connector serves as both the signal connection means and the fixing means of the call module, the size and cost can be reduced.

  According to a sixth aspect of the present invention, in the fifth aspect, the call module and the board are arranged to face each other in an output shaft direction of the speaker, and the first and second connectors are connected to each other of the call module and the board. It is characterized by being provided on each of the opposing surfaces.

  According to the present invention, since the connector serves as both the signal connection means and the fixing means of the call module, the size and cost can be reduced.

  According to a seventh aspect of the present invention, in the fifth aspect, the board is fixed in the apparatus main body with screws, the call module is arranged in parallel in the surface direction of the board, and the first and second connectors are The communication module and the board are provided on opposite sides, respectively.

  According to the present invention, since the connector serves as both the signal connection means and the fixing means of the call module, the size and cost can be reduced.

  As described above, according to the present invention, there is no need to perform a call design according to the shape and size of the apparatus main body, and there is an effect that the design man-hour and the design cost can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
The communication device A of the present embodiment is shown in FIGS. 1 to 5 and is composed of a device main body A1 that forms an outer shell of the device, and a communication module A2 housed in the device main body A1, It is attached via a mounting frame 80 to the front surface of the box 90 embedded and disposed at a proper position. Then, the power line L1 and the information line L2 wired via the box 90 are connected to each other, and function as an intercom apparatus capable of two-way communication between the rooms via the information line L2.

  The apparatus main body A1 has a box (90 mm × 44 mm × 9 .9) whose rear surface is opened by fitting protrusions 101 provided at the four corners of the rear surface of the rectangular panel A10 into fitting holes (not shown) on the front surface of the body A11. 8 mm). A notch 102 is formed at substantially the center of the upper and lower ends of the body A11. By screwing a mounting screw (not shown) into a screw hole (not shown) of the mounting frame 80 via the notch 102, the apparatus main body A1 is attached to the mounting frame. 80. Then, by attaching a mounting bracket or a mounting screw (not shown) to the mounting holes 81 or screw holes 82 provided at both ends of the mounting frame 80, it is fixed to a structure such as a wall surface, and as shown in FIG. A decorative plate PL is attached to the mounting frame 80, and the apparatus main body A1 is exposed from within the frame of the decorative plate PL.

  A front panel A10 of the apparatus main body A1 is provided with a plurality of sound holes 7 for passing sound from an operation unit of the call switch SW1 and a speaker SP described later, and a circuit board is provided inside the apparatus main body A1. G1, G2 and call module A2 are stored.

  The circuit board G1 is disposed behind the call module A2, and the circuit board G1 and the call module A2 placed on the rib in the apparatus main body A1 are sandwiched between the panel A10 and the body A11. Is positioned by. Then, the circuit board G1 has an AC / DC converter 41 that converts the commercial power supply AC supplied from the power line L1 into an operating power supply + V of an internal circuit composed of a stable DC voltage, and information transmitted bidirectionally through the information line L2. A communication transmission unit 42 that transmits and receives signals, and an arithmetic processing unit 43 that performs processing by capturing data from an information signal received by the communication transmission unit 42 and performs data generation processing when sending data via the information line L2. And an I / O interface 44 having an interface function between the arithmetic processing unit 43 and the call module A2, and a connector CN2 (receptacle side) connected to the input / output of the I / O interface 44 and the operation power supply + V (See FIG. 5).

  A voice signal transmitted from the call device A installed in another room or the like via the information line L2 is transmitted to the call module A2 via the communication transmission unit 42, the arithmetic processing unit 43, the I / O interface 44, and the connector CN2. Is transmitted to the communication device A installed in another room or the like via the connector CN2, the I / O interface 44, the arithmetic processing unit 43, and the communication transmission unit 42. Is done.

  The circuit board G2 is screwed to the panel A10 below the call module A2 so as to face the front surface of the apparatus main body A1, and a CPU for performing integrated control of the operation of each part of the apparatus and a call switch SW1. Etc. are mounted and connected to the circuit board G1 by wiring (not shown).

  The call module A2 is disposed in front of the circuit board G1 and above the circuit board G2 so as to face the front face of the call module A2. As shown in FIGS. The module main body A20 (40 mm × 30 mm × 8.6 mm) is composed of A21 and the cover A22 covering the opening of the body A21. The module main body A20 includes a speaker SP, a microphone board MB1, and a sound processing unit 45. A connector CN1 (plug side) is provided on the rear surface of the module main body A20, and the connector CN1 is fitted into the connector CN2 on the circuit board G1 disposed behind the call module A2 (call module A2). And the circuit board G1 are arranged opposite to each other in the output axis direction of the speaker SP), the circuit board G1 and the call module A2 are electrically and mechanically connected, and the power source from the apparatus main body A1 to the call module A2 Supply and signal exchange between the apparatus main body A1 and the call module A2 are performed.

  As shown in FIG. 5, the audio processing unit 45 is composed of an IC including an amplification unit 45a, a signal processing unit 45b, and audio switch units 45c and 45d, and an audio signal received via the connector CN1 After being amplified by the amplifying unit 45a via 45c, it is output from the speaker SP. Further, by operating the call switch SW1, a call can be made, and each audio signal input from the microphone M1 (first microphone) and the microphone M2 (second microphone) on the microphone board MB1 is received by the signal processing unit 45b. After being subjected to signal processing to be described later, the signal passes through the voice switch unit 45d and is transmitted via the connector CN1.

  As shown in FIGS. 8 and 9, the speaker SP includes a yoke (iron-based material having a thickness of about 0.8 mm such as cold rolled steel plate (SPCC, SPKEN), electromagnetic soft iron (SUY)) or a permanent magnet (column). A support body 20 provided with a type neodymium magnet, a residual magnetic flux density of 1.39 T to 1.43 T) and the like, and an edge on the outer peripheral side of the dome-shaped diaphragm 21 is fixed to the support body 20. The diaphragm 21 is formed of a thermoplastic plastic (for example, 35 μm to 50 μm in thickness) such as PEN (polyethylene naphthalate) or PEI (polyetherimide), and is a voice coil (craft paper not shown) fixed to the back of the diaphragm 21. When an audio signal is input to a paper tube having a polyurethane copper wire wound around), an electromagnetic force is generated in the voice coil due to the current of the audio signal and the magnetic field of the permanent magnet of the support 20, so that the diaphragm 21 Is vibrated in the front-rear direction. At this time, a sound corresponding to the audio signal is emitted from the diaphragm 21. That is, an electrodynamic speaker SP is formed (for example, a diameter of 25 mm and a thickness of 3.6 mm). Since the configuration of the electrodynamic speaker is well known, detailed description thereof is omitted.

  The mounting holes 22 provided at the four corners of the support 20 of the speaker SP are placed on the four cylindrical bosses 11 formed at equal intervals on the inner surface of the cover A22, and are formed in the axial direction of the bosses 11. By screwing the attachment screw 23 into the screw hole 11a, the speaker SP is fixed in a state where the diaphragm 21 faces the inner surface of the cover A22. In addition, a plurality of sound holes 12 are formed in a portion of the cover A22 facing the diaphragm 21.

  When the cover A22 to which the speaker SP is fixed is attached to the body A21 and the module main body A20 is assembled, the front air chamber Bf that is a space surrounded by the inner surface of the cover A22 and the front surface side (the diaphragm 21 side) of the speaker SP. Then, a rear air chamber Br which is a space surrounded by the bottom surface of the body A21 and the four inner wall surfaces and the back surface side (the support body 20 side) of the speaker SP is formed. The front air chamber Bf communicates with the outside through a plurality of sound holes 12 provided in the cover A22. The rear air chamber Br is a space that is insulated (not communicated) with the front air chamber Bf by the support 20 of the speaker SP being in close contact with the inner surface of the cover A22, and the cover A22 is further opened at the front opening of the body A21. By being in close contact, it is a sealed space that is insulated from the outside.

  Further, the sound hole 7 provided on the front surface of the apparatus main body A1 and the sound hole 12 provided on the front surface of the call module A2 are formed to face each other, and the sound hole 12 and the sound hole 7 are continuously formed. One sound hole is formed, and the sound radiated from the front surface of the speaker SP is output to the outside through these sound holes.

  Next, as shown in FIG. 10, the microphone substrate MB1 includes a module substrate 2 having both surfaces 2a and 2b. A pair of the microphone bare chip BC1 and ICKa1 and a pair of the microphone bare chip BC2 and ICKa2 are connected to the module substrate 2. Are mounted on one surface 2a, and the wires between the bare chips BC1, ICKa1, and the wiring patterns (not shown) on the module substrate 2 and between the bare chips BC2, ICKa2, and the wiring patterns (not shown) on the module substrate 2 are wired. After each connection (wire bonding) with W, the shield case SC1 is mounted so as to cover the pair of bare chips BC1 and ICKa1, and the shield case SC2 is mounted so as to cover the pair of bare chips BC2 and ICKa2. BC1, ICKa1, and shield case SC1 Microphones M1 to be performed, the bare chip BC2, ICKa2, and a composed microphone M2 with a shield case SC2.

  As shown in FIG. 11, in the bare chip BC (bare chip BC1 or BC2), an Si thin film 1d is formed on one surface side of the silicon substrate 1b so as to close the hole 1c formed in the silicon substrate 1b. An electrode 1f is formed between them via an air gap 1e, and a pad 1g for outputting an audio signal is further provided to constitute a capacitor type silicon microphone. Then, an external acoustic signal vibrates the Si thin film 1d, whereby the capacitance between the Si thin film 1d and the electrode 1f changes to change the amount of charge, and the pad 1g changes with this change in the amount of charge. , 1g, a current corresponding to the acoustic signal flows. In this bare chip BC, the silicon substrate 1b is die-bonded on the module substrate 2, and in particular, the Si thin film 1d of the bare chip BC2 is opposed to the sound collection hole F2 formed in the module substrate 2.

  The microphone M1 uses the bottom surface side of the shield case SC1 provided with the sound collection hole F1 as a sound collection surface, and the microphone M2 uses the mounting surface side of the module substrate 2 provided with the sound collection hole F2 as the sound collection surface. As described above, the sound collecting surfaces are provided on both sides of the module substrate 2 in opposite directions. Since the microphone substrate MB1 configured in this manner has both the microphones M1 and M2 mounted on the one surface 2a of the module substrate 2, the thickness of the microphone substrate MB1 can be reduced.

  FIG. 12A is a plan view of the microphone board MB1 as viewed from the one surface 2a side of the module board 2. The module board 2 has a rectangular part 2f for arranging the microphone M1 and a rectangular part 2g for arranging the microphone M2. And a connecting portion 2h that connects the rectangular portions 2f and 2g, and the rectangular portion 2g is formed larger than the rectangular portion 2f. A negative power supply pad P1, a positive power supply pad P2, an output 1 pad P3, and an output 2 pad P4 are provided along the edge of the rectangular portion 2g.

  As shown in FIG. 12B, the negative power supply pad P1 is connected to the negative side of the power supply voltage supplied from the outside, and the positive power supply pad P2 is connected to the positive side of the power supply voltage. Power is supplied to the microphones M1 and M2 through the pattern. Further, an audio signal collected by the microphone M1 is output from the output 1 pad P3 via a wiring pattern on the module substrate 2, and an audio signal collected by the microphone M2 is output from the output 2 pad P4. It is output via the upper wiring pattern. The ground of the audio signal output from the output pads P3 and P4 is shared by the negative power supply pad P1.

  Thus, the power of the microphones M1 and M2 is supplied from the common negative power supply pad P1 and the positive power supply pad P2, and the ground of each output of the microphones M1 and M2 is shared by the negative power supply pad P1, so that the number of pads The configuration can be simplified.

  Next, the operation of the microphone substrate MB1 will be described.

  First, each current flowing from the bare chips BC1 and BC2 according to the collected acoustic signal is impedance-converted by ICKa1 and Ka2 and converted into a voltage signal, and output from the output 1 pad P3 and the output 2 pad P4 as audio signals, respectively. Is done.

  ICKa (ICKa1 or ICKa2) has the circuit configuration of FIG. 13, and is a constant IC composed of a chip IC that converts a power supply voltage + V (for example, 5V) supplied from power supply pads P1 and P2 into a constant voltage Vr (for example, 12V). A voltage circuit Kb is provided, a constant voltage Vr is applied to the series circuit of the resistor R11 and the bare chip BC, and the connection midpoint between the resistor R11 and the bare chip BC is connected to the junction type J-FET element S11 via the capacitor C11. Connected to the gate terminal. The drain terminal of the J-FET element S11 is connected to the operating power supply + V, and the source terminal is connected to the negative side of the power supply voltage via the resistor R12. Here, the J-FET element S11 is for electrical impedance conversion, and the voltage at the source terminal of the J-FET element S11 is output as an audio signal. Note that the ICKa impedance conversion circuit is not limited to the above-described configuration, and may be, for example, a circuit having a function of a source follower circuit using an operational amplifier, or an audio signal amplification circuit in the ICKa if necessary. May be provided.

  The microphone board MB1 can efficiently configure the signal lines and the power supply lines by performing signal transmission and power supply through the wiring pattern on the module board 2 as described above, and can be attached to the outer surface of the module main body A20. It becomes. In the present embodiment, one surface 2a of the module substrate 2 is arranged along the outside of the front surface of the module main body A20, and the microphone M1 is inserted through the opening 14 on the front surface of the module main body A20 as shown in FIG. The sound collection hole F1 of the microphone M1 that faces the air chamber Bf and is formed in the bottom surface of the shield case SC1 faces the center of the diaphragm 21 of the speaker SP, and is transmitted through the sound collection hole F1. Therefore, even if the sound emitted from the speaker SP has directivity, the speaker sound can be reliably collected. Furthermore, by making the sound collection surface of the microphone M1 face the center of the diaphragm 21 of the speaker SP, the microphone M1 can easily collect the sound emitted by the speaker SP in a correct phase.

  Further, as shown in FIG. 9, the microphone M2 is fitted into a recess 15 provided on the front surface of the module main body A20, and the sound collection hole F2 of the microphone M2 formed in the module substrate 2 is connected via the sound hole 7. Since it faces the outside (front) of the module main body A20, it has high directivity with respect to the voice from the speaker located in front of the communication device A that is transmitted through the sound collection hole F2. . The center of the sound collection hole F2 of the microphone M2 is disposed to face the center of any one of the plurality of sound holes 7 for speaker sound, and a sound hole dedicated to the microphone M2 is provided. Since it is not necessary, the cost can be reduced and the design can be improved. If the distances from the center of the speaker SP to the centers of the microphones M1 and M2 are X1 and X2, respectively, X1 <X2.

  Further, since the rear air chamber Br facing the back surface of the speaker SP is sealed in the module main body A20, the sound radiated from the back surface of the speaker SP is difficult to leak from the rear air chamber Br, and the speaker SP and the microphone M2 The acoustic coupling is reduced. Furthermore, the sound radiated from the back surface of the speaker SP (the back surface of the diaphragm 21) has a phase reversed from that of the sound radiated from the surface of the speaker SP (the surface of the diaphragm 21). When the generated sound circulates forward, the sound radiated from the surface of the speaker SP cancels each other, the radiated sound pressure of the speaker SP decreases, and the speaker in front cannot hear the sound emitted by the speaker SP. However, since the sound radiated from the back surface of the speaker SP is difficult to leak outside the module main body A20 as described above, the radiated sound pressure of the speaker SP due to the wraparound is prevented.

  Further, since the recessed portion 15 in which the microphone M2 is accommodated is a separated space that does not communicate with the rear air chamber Br, the microphone M2 becomes more difficult to collect the sound emitted by the speaker SP, and the speaker SP and the microphone M2 are separated. The acoustic coupling is further reduced. That is, with the above configuration, the sound emitted from the speaker SP and the sound emitted from the speaker are separated and collected by the microphones M1 and M2.

  Further, when the microphone substrate MB1 is disposed in the module main body A20, it is difficult to maintain the spatial insulation between the front air chamber Bf and the rear air chamber Br. However, the microphone substrate MB1 is not provided as in the present embodiment. By attaching to the outer surface of the module main body A20, the spatial insulation between the front air chamber Bf and the rear air chamber Br can be maintained.

  Further, as shown in FIGS. 8 and 9, the call module A2 has one end separated from the inner wall surface along the inner wall surface of the body A21 surrounding the rear air chamber Br on the back surface of the speaker SP, and the other end on the inner wall surface. A continuous tube wall 16 is erected, and a hollow acoustic tube 60 is formed by the tube wall 16, the inner wall surface of the body A21, and the back surface of the cover A22. The acoustic tube 60 is a small-capacity rear air chamber. Arranged in Br. The acoustic tube 60 is a hollow closed tube having a rectangular cross-sectional shape which is bent along the three inner wall surfaces of the rear air chamber Br and is formed over the circumference of the rear air chamber Br over approximately three quarters. (Open end 60a) and the other end is closed (closed end 60b), and the inside of the pipe communicates with the rear air chamber Br via the open end 60a. An acoustic tube uses the fact that the input impedance becomes extremely small at the resonance frequency of the closed tube (the frequency at which the total length of the tube coincides with an odd multiple of a quarter wavelength). The reflected wave has a waveform whose phase is inverted with respect to the incident wave, and the incident wave and the reflected wave cancel each other, thereby reducing the sound wave propagating from the opening end 60a to the outside.

  Such an acoustic tube 60 is provided to shift the lowest resonance frequency of the speaker SP to the low frequency side and further increase the sound pressure level of the speaker SP. Is set to approximately a quarter wavelength of a low frequency (in the present embodiment, around 700 to 800 Hz), the sound quality and efficiency of the speaker SP can be improved even if the rear air chamber Br has a small capacity.

  Further, by forming the acoustic tube 60 continuously over a plurality of inner wall surfaces of the rear air chamber Br, the acoustic tube 60 provided in the rear air chamber Br having a small capacity can be lengthened as necessary. Further, by forming the acoustic tube 60 in a bent shape, the acoustic tube 60 can be disposed in the small-capacity rear air chamber Br.

  And in this embodiment, in order to prevent the howling which generate | occur | produces when the microphones M1 and M2 pick up the audio | voice output of the speaker SP, it has the following structures.

  First, as shown in FIG. 14, the signal processing unit 45 b accommodated in the audio processing unit 45 includes an amplification circuit 30 that non-inverts and amplifies the output of the microphone M <b> 1, and an audio band (300 to 4000 Hz) from the output of the amplification circuit 30. ), A delay circuit 32 that delays the output of the bandpass filter 31, an amplifier circuit 33 that inverts and amplifies the output of the microphone M2, and an audio band from the output of the amplifier circuit 33. A band-pass filter 34 that removes noise at frequencies other than (300 to 4000 Hz), and an adder circuit 35 that adds outputs of the delay circuit 32 and the band-pass filter 34 are provided.

  15 to 18 show the sound signal waveforms of the respective parts of the signal processing unit 45b when the sound from the speakers is collected by the microphones M1 and M2. First, when the distances from the center of the speaker SP to the centers of the microphones M1 and M2 are X1 and X2, respectively, X1 <X2. Therefore, when the sound from the speaker SP is picked up by the microphones M1 and M2, the output Y21 of the microphone M2 is more than the output Y11 of the microphone M1 depending on the distance between the speaker SP and the microphones M1 and M2 and the directivity of the microphones M1 and M2. And the microphone M2 for the delay time [Td = (X2-X1) / Vs] (Vs is the speed of sound) corresponding to the difference (X2-X1) in the distance between the microphones M1, M2 and the speaker SP. The phase of the output Y21 is delayed (see FIGS. 15A and 15B).

  The amplifier circuit 30 generates an output Y12 obtained by non-inverting amplification of the output Y11, and the amplifier circuit 33 generates an output Y22 obtained by inverting and amplifying the output Y21 and inverting the phase by 180 °. At this time, level adjustment corresponding to the difference (X2−X1) in the distance between the two microphones M1, M2 and the speaker SP is performed to match the output levels of the two microphones M1, M2 with respect to the sound from the speaker SP (FIG. 16 ( a) (b)). In the present embodiment, the amplification factor of the amplifier circuit 30 is approximately 1, and the amplifier circuit 30 may be omitted.

  Then, the band pass filters 31 and 34 generate outputs Y13 and Y23 obtained by removing noise of frequencies other than the audio band from the outputs Y12 and Y22 (see FIGS. 17A and 17B).

  Next, the delay circuit 32 is composed of a time delay element or a CR phase delay circuit, and delays the output of the microphone M1 closer to the speaker SP by the delay time Td, so that the output Y14 of the delay circuit 32 and The phase with the output Y23 of the bandpass filter 34 is matched to reduce noise on the transmitted audio signal.

  Then, the sound component from the speaker SP included in the output Y14 and the sound component from the speaker SP included in the output Y23 have the same amplitude and the same phase by the amplification process and the delay process. By adding Y23, an output Ya in which the audio signal corresponding to the audio from the speaker SP is canceled is generated (see FIGS. 18A to 18C). That is, in the output Ya, the sound component from the speaker SP is reduced.

  On the other hand, for the sound emitted by the speaker H in front of the microphones M1, M2, the amplitude of the output Y21 of the microphone M2 having high directivity with respect to the sound emitted by the speaker H is larger than the amplitude of the output Y11 of the microphone M1. Also grows. Furthermore, since the amplification factor of the amplification circuit 33 is larger than the amplification factor of the amplification circuit 30, the speech component from the speaker H included in the output Y23 is further larger than the speech component from the speaker H included in the output Y14. That is, the amplitude difference between the speech component from the speaker H included in the output Y14 and the speech component from the speaker H included in the output Y23 becomes large, and even if the addition process is performed by the addition circuit 35, the output Ya Therefore, the signal corresponding to the voice uttered by the speaker H remains in a state where the amplitude is maintained sufficiently.

  As described above, the sound component from the speaker SP is reduced at the output Ya of the adder circuit 35, and the sound component emitted from the speaker H in front of the communication device A toward the microphone board MB1 remains, and at the output Ya The relative difference between the speech component from the speaker H to be retained and the speech component from the speaker SP to be reduced increases. That is, even when the sound from the speaker H and the sound from the speaker SP are generated at the same time, only the sound component from the speaker SP is reduced while maintaining a sufficient amplitude for the sound component from the speaker H. Therefore, howling that occurs when the microphones M1 and M2 pick up the sound output of the speaker SP can be prevented.

  Furthermore, since the microphone M2 has the sound collection surface facing the outside of the housing A1, and the output direction of the speaker SP and the directivity of the microphone M2 are substantially the same direction, the acoustic coupling between the speaker SP and the microphone M2 is reduced, and the microphone M2 Makes it difficult to collect the sound emitted by the speaker SP, and the microphone M2 can be arranged adjacent to the speaker SP, that is, adjacent to the front air chamber Bf, so that the communication device A can be further reduced in size.

  Next, the voice switch unit 45c is arranged on the transmission line of the received signal, the voice switch unit 45d is arranged on the transmission line of the signal to be transmitted (see FIG. 5), and the voice switch units 45c and 45d are mutually connected. The voice switch section with the smaller input signal level gives a loss amount (for example, 48 dB loss amount) to the transmission line by the variable loss means provided inside. Therefore, a signal having a lower level of the received signal and the transmitted signal is attenuated and the howling margin is further increased (for example, an increase of 48 dB), so that further howling prevention is achieved.

  As described above, in this embodiment, the call module A2 includes the speaker SP, the microphones M1 and M2, and the sound processing unit 45 in the module main body A20, and is surrounded by the inner surface of the module main body A20 and the back surface side of the speaker SP. The air chamber Br is formed, and acoustic structures such as a speaker position, a microphone position, and a capacity of the rear air chamber are determined by the call module A2. Therefore, even if the shape and size of the device main body A1 forming the outline of the communication device A is changed, the desired acoustic characteristics can be obtained by incorporating the call module A2 into each device main body. Therefore, it is not necessary to design a call for each device body having a different size, and the design man-hours and cost can be reduced.

  For example, as shown in FIGS. 19 (a) to 19 (e), as the type of the communication device A, the lobby side terminal (FIG. 19 (a)) of the condominium HA system and the dwelling unit side terminal (FIG. 19 (b) of the condominium HA system are used. )), Door phone device for detached house (FIG. 19 (c)), embedded intercom device for detached house (FIG. 19 (d)), notification device used for child emergency call system (FIG. 19 (e)) The shape and size of the apparatus main body A1 are different from each other. By incorporating the call module A2 into each device main body A1, it is possible to obtain desired acoustic characteristics even if the shape and size of the device main body A1 change.

  In the present embodiment, voice signals are exchanged between the call devices A using a wired communication system via the information line L2, but wireless communication means can be provided by providing known wireless communication means in the call device A. Voice signals may be exchanged using a communication method.

(Embodiment 2)
The basic configuration of the communication device A of the present embodiment is the same as that of the first embodiment, but the communication module A2 has a connector CN1 provided on the lower surface of the module main body A20 as shown in FIG. As shown in FIG. 21, a connector CN3 is provided along the upper side of the connector CN1, and when the connector CN1 is fitted to the connector CN3, the circuit board G2 and the call module A2 are electrically and mechanically connected. Power supply from A1 to the call module A2 and signal exchange between the apparatus main body A1 and the call module A2 are performed (the call module A2 is arranged in parallel in the surface direction of the circuit board G2, and the connectors CN1, CN3 is provided on each side of the call module A2 and the circuit board G2 facing each other). That is, signal exchange and operation power supply + V performed between the call module A2 and the circuit board G1 are performed via the circuit board G2. The call module A2 is fixed to the apparatus main body A1 via a circuit board G2 screwed to the panel A10.

  Other configurations are the same as those in the first embodiment, and a description thereof will be omitted.

It is a perspective view which shows the communication apparatus of Embodiment 1. It is the perspective view which attached the telephone apparatus same as the above to the box. It is a side view of a call apparatus same as the above. It is the top view which attached the plate to the communication apparatus same as the above. It is a circuit block diagram of a communication apparatus same as the above. (A) (b) It is a top view of a circuit board same as the above. It is a perspective view of a call module same as the above. (A) (b) (c) It is a figure which shows the structure of the call module same as the above. It is a disassembled perspective view of the call module same as the above. It is side surface sectional drawing which shows the structure of a microphone substrate same as the above. It is side surface sectional drawing which shows the structure of a bare chip same as the above. It is the (a) simplified top view and (b) simplified circuit diagram which show the structure of a microphone substrate same as the above. It is a circuit diagram of an impedance conversion circuit same as the above. It is a circuit block diagram of a signal processing part same as the above. (A) (b) It is a signal waveform diagram of a signal processing part same as the above. (A) (b) It is a signal waveform diagram of a signal processing part same as the above. (A) (b) It is a signal waveform diagram of a signal processing part same as the above. (A)-(c) It is a signal waveform diagram of the signal processing part same as the above. (A)-(e) It is a figure which shows the kind of communication apparatus same as the above. It is a perspective view of the telephone call module of Embodiment 2. (A) (b) It is a top view of a circuit board same as the above.

Explanation of symbols

A Communication device A1 Device main body A2 Communication module A20 Module main body SP Speaker M1, M2 Microphone Bf Front air chamber Br Rear air chamber

Claims (7)

The module body includes a speaker that outputs audio information transmitted from the outside from one side, and one or more microphones that collect sound and output an audio signal. The inner surface of the module body and the other side of the speaker A call module forming a rear air chamber surrounded by
A communication device comprising: a device main body that houses a communication module and forms an outer shell of the device.   The microphone includes a first microphone and a second microphone disposed at a position farther than the first microphone with respect to a speaker, and the call module receives a first microphone from an audio signal of the second microphone. 2. The communication apparatus according to claim 1, further comprising a voice processing unit that removes a voice signal from the microphone and transmits the signal to the outside.   The call device according to claim 2, wherein the first microphone is opposed to a diaphragm of the speaker.   The apparatus body is provided with a plurality of sound holes on the outer surface for allowing the sound output from the speaker to pass, and the center of the sound collecting hole of the second microphone is disposed to face the center of one of the sound holes. 4. The communication device according to claim 2 or 3, wherein   2. A board on which a first connector is mounted is disposed in the apparatus main body, and the call module includes a second connector that is electrically and mechanically connected to the first connector. 5. The communication device according to any one of 4 to 4.   The call module and the board are arranged to face each other in the output axis direction of the speaker, and the first and second connectors are respectively provided on surfaces of the call module and the board that face each other. The communication device according to claim 5.   The board is fixed in the apparatus main body with screws, the call module is arranged in parallel in the surface direction of the board, and the first and second connectors are provided on opposite sides of the call module and the board, respectively. The communication device according to claim 5, wherein the communication device is a communication device.

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