JP2017112569A - Acoustic wave generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To have an acoustic wave with good quality received by restraining peripheral reflection waves from being received when a generated acoustic wave is received at a desired reception position.SOLUTION: An acoustic wave generator 35 comprises: an acoustic wave generation unit 37 for generating an acoustic wave by converting an output signal obtained by modulating an ultrasonic wave into an acoustic wave; and a cylindrical reflection member 38 having a certain length and both ends in a length direction being open. The reflection member 38 is attached to the acoustic wave generation unit so that the acoustic wave generated by the acoustic wave generation unit is injected into one end of both open ends, and goes out from the other end. In addition, the reflection member 38 is formed such that the area of a cross section gradually increases from the one end to the other end.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a sound wave generator that generates sound waves.

  Various information providing systems that provide information using sound waves have been proposed. Patent Document 1 includes a transmission device that transmits ultrasonic waves including position information, and a portable terminal that receives the ultrasonic waves transmitted from the transmission device and detects position information included in the ultrasonic waves. The system is described.

JP 2006-58164 A

Conventional speakers for converting electrical signals into sound waves are generally non-directional or low-directional.
However, when sound waves are generated using a non-directional or low directivity speaker, the sound waves spread over a wide range of radiation angles. Therefore, not only a sound wave generated directly from a speaker (hereinafter referred to as a direct wave) but also a sound wave that reflects and reaches a surrounding object (for example, a wall surface of a building) far from the speaker. (Hereinafter referred to as ambient reflected waves) may also be received. If various objects with different distances from the speaker are present around the speaker, various different ambient reflected waves may be received by the receiving apparatus.

When the ambient reflected wave is received in addition to the direct wave, the ambient reflected wave becomes noise, and there is a possibility that information desired to be originally acquired cannot be acquired satisfactorily.
The present invention has been made in view of the above problems, and suppresses reception of ambient reflected waves when a generated sound wave is received at a desired reception position, so that sound waves of good quality are received. The purpose is to do.

  The sound wave generator (10, 35) of the present invention includes a signal generator (12), a sound wave generator (37), and a reflecting member (38). The signal generation unit generates an output signal having a frequency lower than that of the reference signal by modulating the reference signal having the frequency of the ultrasonic band. The sound wave generator generates sound waves by converting the output signal generated by the signal generator to sound waves. The reflecting member is a cylindrical member having a fixed length and having both ends opened in the length direction. In this reflection member, a sound wave generated from the sound wave generation unit is incident on one end side of the open ends, and the incident sound wave is radiated from the other end side of the open ends. It is attached so that. The reflecting member is formed so that the area of the cross section gradually increases from one end side to the other end side.

  In such a sound wave generator, the sound wave generated from the sound wave generator is a sound wave obtained by modulating an ultrasonic wave. A sound wave obtained by modulating an ultrasonic wave has a relatively narrow directivity and a characteristic of being easily reflected as compared with a general audible sound (for example, a sound emitted by a person). From the sound wave generator, sound waves having such properties are radiated through the reflecting member. As a result, the sound wave generated from the sound wave generation unit is radiated to the outside at a narrower radiation angle than the case where there is no reflection member, while a part of the sound wave is reflected by the reflection member.

  That is, it is possible to generate a directional sound field with a narrowed radiation angle, thereby suppressing a reflected wave from an object located away from the sound wave generator. Therefore, it is possible to receive sound waves of good quality at a desired reception position.

  In addition, the code | symbol in the parenthesis described in this column and a claim shows the correspondence with the specific means as described in embodiment mentioned later as one aspect, Comprising: The technical scope of this invention is shown. It is not limited.

It is a perspective view showing an outline of an information service system of an embodiment. It is explanatory drawing for demonstrating the state by which the information provision apparatus is incorporated in the illuminating device of embodiment. It is a schematic block diagram of an information provision apparatus. It is the bottom view and perspective view of a reflection member. It is a block diagram of an information provision apparatus. It is explanatory drawing which shows an example of a sound source code and a sound source signal. It is a block diagram of a portable terminal. It is explanatory drawing which shows the example of radiation | emission of the sound wave when there is no reflection member. It is explanatory drawing which shows the example of radiation | emission of the sound wave in case there exists a reflection member. It is explanatory drawing for demonstrating the difference by the presence or absence of a reflection member of the received waveform of the sound wave in a portable terminal. It is a perspective view which shows the other example of an illuminating device. It is a schematic sectional drawing which shows the internal structure of the other example of an illuminating device.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings.
(1) Overall Configuration of Information Providing System As shown in FIG. 1, the information providing system 1 of the present embodiment includes a lighting device 40, an information providing device 10 built in the lighting device 40, and a mobile terminal 20. Prepare. FIG. 1 shows an example in which the lighting device 40 is provided at a substantially intermediate portion between the walls 7 and 8 on both sides of the passage in the ceiling 2 of the indoor passage.

  The lighting device 40 includes a main body 41 and two fluorescent lamps 42 attached to the main body 41. The two fluorescent lamps 42 as light sources emit light when a switch (not shown) is turned on and power is supplied, and irradiate the surroundings with light.

  As shown in FIG. 2, the information providing apparatus 10 is built in the main body 41. The information providing apparatus 10 provides various types of information using sound waves. The information providing apparatus 10 includes a modulation circuit 11 and a speaker unit 35. The modulation circuit 11 generates a sound source signal modulated by information to be provided (hereinafter, provided information), and outputs a transmission signal in which the sound source signal is amplified. The speaker unit 35 converts the transmission signal from the modulation circuit 11 into sound waves and outputs it. Note that the sound wave of the transmission signal including the provided information is hereinafter referred to as an information sound wave. The information sound wave output from the information providing apparatus 10 of the present embodiment is a sound wave in a predetermined frequency band including, for example, 20 kHz.

  As shown in FIGS. 1 and 2, a substantially circular radiation hole 43 is formed in the main body 41 of the lighting device 40. The information providing device 10 is provided inside the main body 41 so that the sound wave output from the speaker unit 35 is radiated from the radiation hole 43 of the main body 41 to the floor 6 side of the passage. FIG. 1 shows a state in which a user 4 holding the portable terminal 20 stands in the vicinity of the passage 40 in the vicinity of the radiation hole 43 of the lighting device 40.

  The portable terminal 20 can receive information sound waves radiated from the information providing apparatus 10. The portable terminal 20 receives the information sound wave radiated from the information providing apparatus 10 and notifies information based on the provided information included in the received information sound wave. The final notification of information on the mobile terminal 20 is performed by at least one of notification by image and notification by voice. The user 4 of the mobile terminal 20 takes the mobile terminal 20 within a range in which the information sound wave radiated from the information providing apparatus 10 can be received, thereby providing the provided information received from the information providing apparatus 10 by the mobile terminal 20. Based information can be obtained in at least one of image and sound.

  In the present embodiment, position related information related to the position where the information providing apparatus 10 is installed is output as the provided information. Various specific contents of the position-related information are conceivable, and may be contents directly indicating the location of the information providing apparatus 10 such as latitude and longitude, an address, etc. It may be the information. Note that providing information is position-related information is merely an example, and information different from position-related information may be provided to the user.

(2) Configuration of Information Providing Device As shown in FIG. 3, the information providing device 10 includes a modulation circuit 11 and a speaker unit 35. For example, commercial AC power of 100 V is supplied to the modulation circuit 11 through an outlet 19. The modulation circuit 11 is operated by the supplied power. Note that, for example, the commercial AC 100V power supply for the fluorescent lamp 42 drawn into the lighting device 40 without being connected to the outlet 19 may be distributed and supplied to the modulation circuit 11 together with the fluorescent lamp 42. Where and how the power supply for operating the modulation circuit 11 is supplied can be determined as appropriate.

  The speaker unit 35 includes a case 36, a speaker 37, and a reflection member 38. The speaker 37 can generate sound waves. The speaker 37 of the present embodiment is, for example, a piezoelectric speaker that includes a piezoelectric ceramic element as a vibrator. When a transmission signal that is an electrical signal including provided information is input from the modulation circuit 11, the speaker 37 generates an information sound wave by converting the transmission signal into mechanical vibration of a piezoelectric ceramic element.

  Sound waves generated by the speaker 37 are radiated through a cylindrical reflection member 38. The reflecting member 38 is a cylindrical member having both ends opened. More specifically, as shown in FIGS. 3 and 4, the reflecting member 38 has a truncated cone shape as a whole. The length of the reflecting member 38, that is, the length in the height direction of the truncated cone, and the length in the vertical direction in FIG. 4 is Lh.

  Both ends of the reflecting member 38 in the length direction are opened. Specifically, an incident opening 38a is formed on one end side in the length direction, and a radiation opening 38b is formed on the other end side in the length direction. Each of the openings 38a and 38 is circular. The incident-side opening diameter, which is the diameter of the incident opening 38a, is φa, and the radiation-side opening diameter, which is the diameter of the radiation opening 38b, is φb, and the magnitude relationship between them is φa <φb. A line connecting the center points Pa and Pb of the openings 38a and 38b is referred to as a center axis Xc.

  Since the reflecting member 38 has a truncated cone shape as a whole, the cross section perpendicular to the length direction is entirely circular from the incident opening 38a to the radiation opening 38b. Further, the area of the circular cross section gradually increases from the incident opening 38a toward the radiation opening 38b. Specifically, the spread angle β, which is an angle formed by the central axis Xc and the bus bar 38c, is a predetermined angle greater than 0 °.

  As shown in FIGS. 3 and 4, the reflection member 38 is entirely or almost completely covered with the opening surface of the incident opening 38 a with respect to the speaker 37. It is attached as follows. Therefore, all or almost all of the sound waves output from the speaker 37 are incident on the reflecting member 38 from the incident opening 38a. The incident sound wave is radiated from the radiation opening 38 b through the internal space of the reflecting member 38.

  As shown in FIG. 5, the modulation circuit 11 includes a control unit 12, an amplifier 13, and a wireless communication unit 14. The modulation circuit 11 includes a power supply circuit (not shown) that generates a DC control voltage Vcc from power supply power of commercial AC 100V. Each part in the modulation circuit 11 is operated by a control voltage Vcc generated by the power supply circuit.

  The control unit 12 is configured as a known microcomputer having a CPU 16 and a memory 17. The memory 17 includes a semiconductor memory such as a RAM, a ROM, and a flash memory.

  Various programs and data are stored in the memory 17. The data stored in the memory 17 includes provided information data and various setting information data transmitted by sound waves.

  The CPU 16 implements various functions by executing various programs stored in the non-transitional tangible recording medium. In the present embodiment, the memory 17 storing the program corresponds to a non-transitional tangible recording medium. The function of the control unit 12 includes at least a signal generation function for generating a sound source signal including provided information.

  The number of microcomputers constituting the control unit 12 may be one or plural. In addition, the realization of various functions in the control unit 12 is not limited to so-called software processing based on a program, and some or all of the various functions are realized using hardware that combines a logic circuit, an analog circuit, and the like. Also good.

  Specifically, the signal generation function by the control unit 12 is realized as follows. That is, the control unit 12 creates a sound source code having a predetermined data format based on the provided information data stored in the memory 17.

  The sound source code mainly has a header part and a body part as illustrated in the upper part of FIG. Among these, the header part is an N-bit data area indicating the start of the sound source code. The body part is an M-bit data area. N and M are each a natural number of 1 or more. Data indicating the information is included in the body part. In the present embodiment, all N bits are “0” in the header portion.

  The control unit 12 continuously generates and outputs a sound source signal during a predetermined output period based on the sound source code including the data of the provided information. The sound source signal is a pulse having a predetermined frequency Fx as illustrated in the lower part of FIG.

  The control unit 12 generates a sound source signal according to the value of each bit of the sound source code. Specifically, a pulse is output for the bit value “1”, and no pulse is output for the bit value “0”. Therefore, during the period corresponding to the header portion of the sound source code among all the sound source signals corresponding to one sound source code, since the header portion is all “0”, no pulse is output and the signal voltage is 0. Maintained.

  In the present embodiment, when generating the sound source signal, the control unit 12 first generates an ultrasonic band pulse of a predetermined frequency (for example, 40 kHz) as a reference signal. Then, the sound source signal is generated by modulating the pulse of the reference signal of the ultrasonic band. Specifically, for example, by cutting every other pulse with respect to the reference signal, an apparent 20 kHz pulse wave is obtained, and the 20 kHz pulse wave corresponds to each bit value of the sound source code. . As a result, a sound source signal of 20 kHz is finally generated. The sound source signal generated by modulating the reference signal of the ultrasonic band in this way is converted into a sound wave by the speaker 37 and transmitted.

  The sound pressure level of the finally output sound wave can be adjusted by, for example, the pulse width of the sound source signal pulse. The larger the pulse width, the higher the sound pressure level of the sound wave. In the present embodiment, as illustrated in the lower part of FIG. 6, the pulse width Tx [sec.] Of the pulse of the sound source signal has a period corresponding to 1/4 of the period of the frequency Fx as the reference width T0 [sec.]. The reference width T0 can be set to an arbitrary width. The pulse width Tx can be arbitrarily changed, for example, directly from the outside or by remote operation. By adjusting the pulse width Tx, the sound pressure level of the sound wave can be arbitrarily set.

  The output period for generating and outputting the sound source signal can be determined as appropriate. For example, the entire period during which the control unit 12 is operating may be set as the output period, or a certain output period may be periodically generated. Alternatively, a predetermined output period may be set every time a predetermined output condition is satisfied, and output may be performed during that period.

  In the present embodiment, as illustrated in the lower part of FIG. 6, sound source signals are continuously generated and output during the output period. The sound source signal generated by the control unit 12 is amplified by the amplifier 13 and input to the speaker 37, and is converted into a sound wave and transmitted.

  The amplifier 13 receives the sound source signal generated by the control unit 12, amplifies the sound source signal, and outputs it to the speaker 37. A transmission signal obtained by amplifying the sound source signal by the amplifier 13 is converted into an information sound wave by the speaker 37 and output.

  The wireless communication unit 14 is a communication module for performing wireless data transmission / reception with an external communication device. The wireless communication unit 14 can transmit and receive radio waves based on a predetermined communication method. In this embodiment, the communication method supported by the wireless communication unit 14 is, for example, Bluetooth. Note that Bluetooth is a registered trademark. Various adjustments to the modulation circuit 11 can be performed from an external communication device using data communication via the wireless communication unit 14. Specific examples of the adjustment work include, for example, updating of provided information, various settings (for example, setting of the above-described pulse width Tx), and updating and reading of various other information.

  The set value of the pulse width Tx is stored in the memory 17 of the control unit 12, for example. The control unit 12 generates a pulse of the reference signal based on the pulse width Tx stored in the memory 17 and modulates the reference signal based on the sound source code to generate a sound source signal.

  Note that the frequency of the sound source signal generated by the control unit 12 is 20 kHz, and that the frequency of the information sound wave including the provided information output from the speaker 37 is only an example. For example, a non-audible sound band other than the 20 kHz band may be used. Further, it is not necessarily a non-audible sound, and may be a band of an audible sound.

(3) Configuration of Mobile Terminal As shown in FIG. 7, the mobile terminal 20 includes a control unit 21, a wireless communication unit 22, a display unit 23, an operation input unit 24, an audio output unit 25, and a microphone 26.

  The control unit 21 is configured as a known microcomputer having a CPU 31 and a memory 32. The memory 32 includes a semiconductor memory such as a RAM, a ROM, and a flash memory. Various programs and data are stored in the memory 32.

  The CPU 31 implements various functions by executing various programs stored in the memory 32. The number of microcomputers constituting the control unit 21 may be one or plural. In addition, the realization of various functions in the control unit 21 is not limited to so-called software processing based on a program, and some or all of the various functions are realized using hardware that combines a logic circuit, an analog circuit, and the like. Also good.

  The functions realized by the control unit 21 include a telephone function and an information notification function. The telephone function is a function that enables a voice call through the mobile phone communication network by connecting to the mobile phone communication network via the wireless communication unit 22.

  When the information sound wave transmitted from the information providing device 10 is received by the microphone 26, the information notification function displays the provided information from the information providing device 10 included in the information sound wave, the display unit 23 and the sound output. This is a function to notify the user by outputting from at least one of the units 25.

  The wireless communication unit 22 is a communication module for performing wireless communication using a predetermined communication method. The communication method supported by the wireless communication unit 22 is, for example, a communication method (for example, LTE) used in a mobile phone communication network. The above telephone function is realized by using the wireless communication unit 22.

  The display unit 23 has a display screen (for example, a liquid crystal display) installed on the front surface of the casing of the mobile terminal 20. The display unit 23 displays an image on the display screen according to image data indicating an image to be displayed, which is input from the control unit 21.

  The operation input unit 24 includes a touch panel installed on the display screen of the display unit 23 and a switch installed around the display screen of the display unit 23. A user of the mobile terminal 20 (for example, the user 4 in FIG. 1) can cause the mobile terminal 20 to execute various functions by performing various input operations on the operation input unit 24. When the user performs an input operation via a touch panel and a switch, the operation input unit 24 outputs operation information indicating the content of the input operation to the control unit 21. When the operation information is input from the operation input unit 24, the control unit 21 performs various processes based on the operation information.

The sound output unit 25 outputs various sounds. The audio output unit 25 outputs audio according to audio data input from the control unit 21 and indicating audio to be output.
The microphone 26 receives sound waves generated in the surroundings, converts them into electrical signals, and inputs them to the control unit 12. The microphone 26 has two main purposes. One is to input a voice uttered by a user during a voice call. The other is to receive the information sound wave transmitted from the information providing apparatus 10.

  When the information sound wave from the information providing apparatus 10 is received by the microphone 26, the received signal is input to the control unit 21, whereby the control unit 21 can obtain the provided information included in the received signal. . When the control unit 21 acquires the provision information transmitted from the information provision apparatus 10 by the information sound wave, the control unit 21 causes the information notification function to notify the provision information. With this information notification function, the user of the mobile terminal 20 can obtain provided information provided from the information providing apparatus 10.

(4) Action of Reflecting Member The information providing apparatus 10 of the present embodiment radiates the information sound wave generated by the speaker 37 via the reflecting member 38 instead of radiating the information sound wave to the outside of the information providing apparatus 10 as it is.

  The information sound wave of the present embodiment is a sound wave obtained by modulating an ultrasonic wave as described above. A sound wave obtained by modulating an ultrasonic wave has a relatively narrow directivity compared to a general audible sound (for example, a sound emitted by a person).

  However, if the information sound wave is radiated directly from the speaker 37 without providing the reflecting member 38, the directivity becomes wider as illustrated in FIG. It spreads and radiates with a wide radiation angle α.

  In FIG. 8, the reception height L01 is the height from the floor 6 to the reception assumed surface W, and is, for example, 1 [m]. The assumed reception surface W is a surface perpendicular to the floor surface, that is, a surface perpendicular to the central axis Xc, and is assumed to be portable when the user 4 attempts to acquire information from information sound waves using the portable terminal 20. This is the location where the terminal 20 exists. Further, in FIG. 8, the propagation length L02 is the distance from the speaker 37 to the assumed reception surface W, and is, for example, 1.5 [m]. The wall surface distance L2 is a distance from the central axis Xc to the wall 7 and the wall 8, and is, for example, 1.3 [m].

  When the reflecting member 38 is not used, the directivity is wide as illustrated in FIG. 8, and the radiation angle α is 55 °, for example. Therefore, when the portable terminal 20 is positioned on the assumed reception surface W, for example, when the information sound wave is emitted from the speaker 37, the waveform of the reception signal of the information sound wave received by the portable terminal 20 is as follows. , 8 and the like, and may be disturbed by the influence of reflection from surrounding objects away from the speaker 37. The influence of the reflection becomes larger as it is closer to the central portion of the assumed reception surface W, that is, closer to the central axis Xc.

  On the other hand, in the present embodiment in which the reflection member 38 is attached to the speaker 37, the information sound wave generated by the speaker 37 is radiated through the cylindrical reflection member 38. In addition, a sound wave obtained by modulating an ultrasonic wave has a characteristic of being easily reflected as compared with a general audible sound (for example, a sound emitted by a person).

  Therefore, as illustrated in FIG. 9, the directivity of the information sound wave radiated from the speaker unit 35 is narrower than that in the case where the reflecting member 38 is not provided, and the possibility of reflection by surrounding objects is reduced. Moreover, when the information sound wave passes through the reflecting member 38, the information sound wave is amplified in the reflecting member 38. Therefore, as a result, the waveform of the reception signal of the information sound wave received on the assumed reception surface W is a waveform with less noise components in which the disturbance due to the ambient reflected wave is suppressed compared to the case where the reflection member 38 is not provided. .

  In the example of FIG. 9, the spread angle β of the reflecting member 38 is, for example, 10 °, the member length Lh of the reflecting member 38 is, for example, 20 [mm], and the incident side opening diameter φa of the reflecting member 38 is, for example, 14 [mm]. Then, the radiation angle α of the information sound wave radiated from the speaker unit 35 is, for example, 30 °, and the directivity is clearly narrower than the example of FIG.

  The difference in the waveform of the received signal depending on the presence or absence of the reflecting member 38 is also apparent from the waveform example of FIG. As illustrated in the upper part of FIG. 10, when there is no reflection member 38, the waveform of the reception signal of the information sound wave received by the mobile terminal 20 near the center of the reception assumed plane W is not the component of the waveform that is originally desired to be acquired. A relatively large amount of other noise components are superimposed. Therefore, there is a possibility that the provided information cannot be normally demodulated from the received signal.

  On the other hand, in the case of the present embodiment in which the reflecting member 38 is provided, the noise component included in the waveform of the received signal is small as illustrated in the lower part of FIG. ing.

  The directivity adjustment of the information sound wave radiated from the speaker unit 35, that is, the adjustment of the radiation angle α can be performed mainly by adjusting at least one of the member length Lh and the spread angle β of the reflecting member 38. The longer the member length Lh and the smaller the spread angle β, the smaller the radiation angle α and the more directivity can be reduced.

  Even if there is a restriction that the incident side opening diameter φa and the radiation side opening diameter φb of the reflecting member 38 must be set to certain values, the directivity is adjusted by adjusting the member length Lh and the spread angle β. be able to. When the incident side opening diameter φa and the emission side opening diameter φb are fixed values, the spread angle β is inevitably reduced when the member length Lh is increased.

  The transmission distance of the information sound wave from the speaker unit 35, that is, the distance at which the information sound wave can be normally received can be adjusted by adjusting the sound pressure level of the information sound wave. As described above, in the present embodiment, the information sound wave is output using the pulse-shaped reference signal of the ultrasonic band, and the sound pressure level can be adjusted by adjusting the pulse width Tx. That is, when it is desired to transmit the information sound wave farther by increasing the sound pressure level, the pulse width Tx may be increased.

  Therefore, even if the installation conditions for installing the speaker unit 35 are different, the member length Lh of the reflecting member 38 is adjusted, the spread angle β of the reflecting member 38 is adjusted, By adjusting the sound pressure level, it is possible to radiate information sound waves appropriately corresponding to the installation conditions. For example, when it is necessary to attach the speaker unit 35 to a high position and the distance to the reception position of the information sound wave becomes long, for example, by increasing the sound pressure level or reducing the spread angle β, It is possible to appropriately receive the information sound wave at the reception position.

(5) Effects of the Embodiment According to the embodiment described above, the following effects can be obtained.
That is, in the information providing apparatus 10 of the present embodiment, a sound source signal obtained by modulating the reference signal of the ultrasonic band is converted into a sound wave by the speaker 37 and output as an information sound wave. The information sound wave is radiated through the reflecting member 38. As a result, a part of the information sound wave generated from the speaker 37 is reflected in the reflecting member 38 and is radiated to the outside at a narrower radiation angle α as compared with the case where the reflecting member 38 is not provided.

  That is, it is possible to generate a directional sound field in which the radiation angle α is narrowed, and thereby it is possible to suppress ambient reflected waves from an object located away from the speaker 37. For this reason, the mobile terminal 20 can receive information sound waves of good quality. In other words, the mobile terminal 20 can obtain a reception signal with less noise component as a reception signal obtained by converting the received information sound wave into an electric signal. Therefore, provision information can be appropriately acquired from the received signal with less noise components.

  Further, even if the speaker 37 itself is an inexpensive speaker with no directivity or low directivity, the directivity of the directivity can be reduced by providing the reflective member 38 and appropriately setting the size, shape, etc. of the reflective member 38. Sharp desired propagation characteristics can be obtained.

  Further, the reflecting member 38 of the present embodiment has a truncated cone shape as a whole, and has a simple outer shape. In addition, due to the shape of the truncated cone, the outer periphery of the cross section is inevitably circular, and the area of the cross section gradually increases from the incident opening 38a toward the radiation opening 38b. Therefore, it is possible to easily provide the reflecting member 38 having a relatively high noise component reduction effect.

  Further, the transmission distance of the information sound wave can be easily adjusted by adjusting the pulse width Tx of the pulse of the reference signal. Further, the radiation angle α of the information sound wave can be easily adjusted by appropriately adjusting the member length Lh, the spread angle β, the opening diameters φa, φb, and the like of the reflecting member 38.

  In the present embodiment, the speaker unit 35 is built in the lighting device 40, and the presence of the speaker unit 35 cannot be easily recognized from the outside of the lighting device 40. If the speaker unit 35 is to be installed alone, it is difficult to install the speaker unit 35 on the ceiling from the viewpoint of aesthetics or protection of the speaker unit 35, and the installation location is restricted. This is because if installed on the ceiling or other conspicuous places, there is a risk that the aesthetic appearance may be lost or the product may be intentionally damaged.

  On the other hand, in this embodiment, the speaker unit 35 can be built in the lighting device 40. In general, the lighting device 40 is often installed indoors in a central part of a passage or a room. In other words, the lighting device 40 is often installed indoors at a position above where a person exists. Therefore, the fact that the speaker unit 35 is built in the lighting device 40 inevitably means that the speaker unit 35 is installed at an appropriate position while making it difficult to notice the presence of the speaker unit 35.

(6) Correspondence Relationship with Claims Here, the correspondence relationship between the words of the present embodiment and the words of the claims will be described. The speaker unit 35 and the information providing apparatus 10 having the speaker unit 35 correspond to a sound wave generator. The control unit 12 in the modulation circuit 11 corresponds to a signal generation unit and a pulse width setting unit, a transmission signal input to the speaker 37 corresponds to an output signal, the speaker 37 corresponds to a sound wave generation unit, and a portable terminal. Reference numeral 20 corresponds to an information notification device.

[Other Embodiments]
As mentioned above, although embodiment of this invention was described, this invention can take a various form, without being limited to the said embodiment.

  (1) The lighting device that can incorporate the information providing device 10 is not limited to the lighting device 40 shown in FIGS. 1 and 2. You may make it incorporate the information provision apparatus 10 with respect to the illuminating device of another shape and a structure.

  For example, the information providing device 10 may be built in the lighting device 60 having a shape as shown in FIGS. The lighting device 60 includes a main body 61, a cover 62, and a socket 63. The cover 62 is a translucent annular member that can transmit light, and is attached on the distal end side of the main body 61 so as to cover the distal end surface thereof. The socket 63 has an electrode for inputting power to the lighting device 60.

  A plurality of illumination LEDs 64 are arranged in an arc shape on all end faces of the main body 61. The cover 62 is attached so as to cover the plurality of illumination LEDs 64 arranged in the arc shape from the front side. The modulation circuit 11 constituting the information providing apparatus 10 is accommodated in the main body 61 as shown in FIG. The speaker unit 35 constituting the information providing apparatus 10 is arranged so as to protrude from the front end surface of the main body 61. However, the entire side surface of the speaker unit 35 is covered with an annular cover 62 and is not exposed to the outside.

  However, the speaker unit 35 is disposed such that the radiation opening 38 b in the reflecting member 38 faces the central hole in the annular cover 62. Thereby, the sound wave generated from the speaker 37 and radiated through the reflecting member 38 is radiated to the outside from the central hole portion in the cover 62.

  (2) The information providing device 10 may be incorporated in a device other than the lighting device. For example, you may incorporate in other apparatuses, such as a sprinkler and a human detection sensor which are often installed in the indoor ceiling of a building. Moreover, it is not indispensable to incorporate in the apparatus installed in an indoor ceiling. You may incorporate in the apparatus installed in places other than an indoor ceiling.

  Further, when the information providing device 10 is built in the lighting device or other devices, it is not essential that the information providing device 10 is completely built in so as not to protrude outside. For example, a part of the modulation circuit 11 may protrude to the outside of the lighting device, or a part of the reflecting member 38 (for example, the end on the radiation opening 38b side) may protrude to the outside of the lighting device.

Alternatively, only a part of each component constituting the information providing apparatus 10 may be built in a device such as a lighting device, and the other components may be installed outside the device such as a lighting device.
In addition, it is not essential to incorporate the information providing apparatus 10 in another apparatus such as a lighting apparatus. The information providing apparatus 10 may be installed alone at a desired installation position such as a ceiling.

(3) The shape of the reflecting member 38 is not limited to the shape of a truncated cone. The outer shape may be different from that of the truncated cone.
The reflecting member 38 is not limited to a perfect circle in cross section. For example, a reflective member having an elliptical cross-sectional shape may be used. Further, it is not essential that the entire outer periphery of the cross section is a curve. For example, a reflecting member having a polygonal cross section may be used.

  Further, the cross-sectional shape may change between the incident opening 38a and the radiation opening 38b. Also, there is no particular limitation on how the area of the cross section gradually increases between the incident opening 38a and the radiation opening 38b. For example, a reflecting member having a shape in which the cross-sectional area or the cross-sectional diameter increases in a quadratic function may be used. In addition, the circular cross section may have a shape whose diameter increases in a higher order function than the second order, or may have a shape that increases exponentially.

  Thus, how to make the cross-sectional shape, how to specifically increase the cross-sectional area from the incident opening to the radiation opening, and the shape of the cross-section from the incident opening to the radiation opening The specific shape of the reflecting member may be determined as appropriate, including whether the value is constant or changed.

  (4) The method of generating the sound source signal as the output signal is not limited to the method of modulating the ultrasonic band reference signal using the sound source code as shown in FIG. It is not essential that the reference signal has a pulse-like waveform, and it is not essential to use the sound source code of the format shown in FIG. 6 as a signal for modulating the reference signal. As a result, it is only necessary to generate a sound source signal (20 kHz in the above example) having a frequency lower than that of the reference signal by modulating the reference signal of the ultrasonic band, and the type, frequency, modulation method, and the like of the reference signal used for that purpose are as follows: You may decide suitably.

  (5) The functions of one component in the above embodiment may be distributed as a plurality of components, or the functions of a plurality of components may be integrated into one component. Moreover, you may abbreviate | omit a part of structure of the said embodiment. In addition, at least a part of the configuration of the above embodiment may be added to or replaced with the configuration of the other embodiment. In addition, all the aspects included in the technical idea specified only by the wording described in the claim are embodiment of this invention.

  (6) In addition to the above-described speaker unit 35 and the information providing apparatus 10 having the speaker unit 35, a system including the speaker unit 35 or the information providing apparatus 10 as a component, and a function of a computer as the information providing apparatus 10 The present invention can also be realized in various forms such as a program, a medium on which the program is recorded, and a method used in the information providing apparatus 10.

  DESCRIPTION OF SYMBOLS 1 ... Information provision system, 2 ... Ceiling, 10 ... Information provision apparatus, 11 ... Modulation circuit, 12, 21 ... Control part, 13 ... Amplifier, 14, 22 ... Wireless communication part, 16, 31 ... CPU, 17, 32 ... Memory, 20 ... portable terminal, 23 ... display unit, 24 ... operation input unit, 25 ... audio output unit, 26 ... microphone, 35 ... speaker unit, 36 ... case, 37 ... speaker, 38 ... reflecting member, 38a ... incident aperture Part, 38b ... radiation opening, 38c ... busbar, 40, 60 ... lighting device, 41, 61 ... main body, 42 ... fluorescent lamp, 43 ... radiation hole, 62 ... cover, 63 ... socket, 64 ... LED for illumination.

Claims (5)

A signal generator (12) that generates an output signal having a frequency lower than that of the reference signal by modulating a reference signal having a frequency of an ultrasonic band;
A sound wave generator (37) that generates a sound wave by converting the output signal generated by the signal generator into a sound wave;
A cylindrical member having a fixed length and both ends opened in the length direction, and the sound wave generated from the sound wave generation unit is incident on one end side of the opened both ends with respect to the sound wave generation unit. A reflection member (38) is attached so that an incident sound wave is radiated from the other end side of the both open ends, and the cross-sectional area gradually increases from the one end side toward the other end side. )When,
A sound wave generator (10, 35). The sound wave generator according to claim 1,
The reflection member is a sound wave generating device formed so that an outer periphery of the cross section is continuously circular from the one end side to the other end side. The sound wave generator according to claim 2,
The reflection member is a sound wave generator, the outer shape of which is formed to have a truncated cone shape. It is a sound wave generator of any one of Claims 1-3,
The signal generation unit is configured to generate the output signal by modulating the pulsed reference signal,
Furthermore, a pulse width setting unit (12) for setting a pulse width of a pulse constituting the reference signal is provided.
Sound wave generator. The sound wave generator according to any one of claims 1 to 4,
The said sound wave generator is a sound wave generator built in the illuminating device (40, 60) comprised so that light may be irradiated from a light source (42, 64).