Vehicle broadcasting device

Abstract

To provide a vehicle broadcasting device capable of automatically changing over an output destination in response to a type of a sound signal while utilizing an existing vehicle broadcasting facility.SOLUTION: A vehicle broadcasting device with a plurality of speakers arranged therein includes: a tone detection section 41 for detecting a tone signal from a tone sound signal on which the tone signal has been superimposed with respect to an input sound signal; and a selection section 44 for selecting the speaker to be an output destination. The selection section 44 selects the speaker corresponding to the tone signal detected by the tone detection section 41 as the output destination.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a vehicle broadcasting device in which a plurality of speakers are arranged in a vehicle. [Background technology]

[0002] Vehicles used in public transportation such as railway cars are equipped with a vehicle broadcasting system that allows staff to make announcements to passengers and others. The vehicle broadcasting system is equipped with an in-car speaker for broadcasting to passenger compartments, an exterior speaker for broadcasting to the exterior of the vehicle, and a communication speaker for communication between the driver's cab at the front of the vehicle and the staff room in the rearmost car. The vehicle broadcasting system is configured so that a control amplifier installed in the driver's cab of the front vehicle (the staff room at the rearmost car) is connected to speakers installed in each vehicle via one or more wires that are routed to each vehicle (see Patent Documents 1 and 2).

[0003] However, even after being used by the public transportation system in which they were introduced, such vehicles are often used as second-hand vehicles by different public transportation systems. In other words, the vehicles themselves are often used over a long period of time by each transportation system, undergoing repeated repairs. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-182129 [Patent Document 2] Japanese Patent Application Laid-Open No. 2004-182130 Summary of the Invention [Problem to be solved by the invention]

[0005] While improvements to the operability of such vehicles are desirable each time they are modified, for example, to reduce the workload of staff during operation, adding additional wiring to the vehicle is rare because it requires modifying the entire vehicle. For this reason, it is desirable to modify the vehicle broadcasting device using the existing wiring. It is also desirable to reuse existing devices for other devices on the vehicle. [Means for solving the problem]

[0006] The vehicle broadcasting device for solving the above problem is a vehicle broadcasting device equipped with a plurality of speakers, and includes a tone detection unit that detects a tone signal from a toned audio signal in which the tone signal is superimposed on an input audio signal, and a selection unit that selects the speaker that will be the output destination, and the selection unit selects the speaker that corresponds to the tone signal detected by the tone detection unit as the output destination. [Effects of the Invention]

[0007] According to the present invention, it is possible to improve operability while utilizing existing train lines and facilities. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating a vehicle equipped with a conventional broadcasting device. [Figure 2] FIG. 2 is a diagram illustrating a vehicle equipped with a broadcasting device according to the first embodiment. [Figure 3] FIG. 3 is a diagram illustrating a broadcasting device in the first embodiment. [Figure 4] FIG. 4 is a diagram illustrating a vehicle equipped with a broadcasting device according to the second embodiment. [Figure 5] FIG. 5 is a diagram illustrating a broadcasting device according to the second embodiment. [Figure 6] FIG. 6 is a diagram showing an example of broadcast settings. [Figure 7] FIG. 7 is a diagram showing another example of broadcast settings. DETAILED DESCRIPTION OF THE INVENTION

[0009] A vehicle broadcasting device to which the present invention is applied will be described below with reference to the drawings. [Configuration of a vehicle equipped with a conventional broadcasting device] As shown in Figure 1, the vehicle to which the present invention is applied is, for example, a vehicle made up of three connected cars, with the leading car 11 having a driver's cab at the front and passenger compartments behind the driver's cab. The second car 12 is a passenger car with passenger compartments throughout. The last car 13 has an attendant's cab at the rear and passenger compartments ahead of the attendant's cab.

[0010] Each of the carriages 11, 12, and 13 is provided with an in-car speaker 16 for broadcasting to the passenger carriage, and exterior speakers 17a and 17b for broadcasting to the exterior of the carriage. The exterior speaker 17a is a mountain-side exterior speaker. The exterior speaker 17b is an ocean-side exterior speaker. The leading car 11 is equipped with a leading communication speaker 18 in the driver's cab. The last car 13 is equipped with a trailing communication speaker 19 in the operator's cab.

[0011] The conventional vehicle is equipped with a broadcasting device 20. The broadcasting device 20 includes an in-car speaker 16 and external speakers 17a and 17b provided in each of the cars 11 to 13, a front communication speaker 18 provided in the driver's cab of the lead car 11, and a rear communication speaker 19 provided in the operator's cab of the last car 13. The broadcasting device 20 also includes an output amplifier 21 in each of the cars 11 to 13.

[0012] The output amplifier 21 includes an amplifier 22 that amplifies the audio signal and outputs it to each speaker, and an output destination switching unit 23 that selects the speaker to which the signal is to be output. The output destination switching unit 23 includes a first switch 23a that switches the output of the in-vehicle speaker 16 on and off, a second switch 23b that switches the output of the mountain-side exterior speaker 17a on and off, and a third switch 23c that switches the output of the sea-side exterior speaker 17b on and off.

[0013] Furthermore, the broadcasting device 20 is equipped with an amplifier 24 in front of the front communication speaker 18 and the rear communication speaker 19 in each of the lead car 11 and the rear car 13. Furthermore, the broadcasting device 20 is equipped with a control amplifier 25 in the driver's cab of the lead car 11 and the operator's cab of the rear car 13. The control amplifier 25 is equipped with a first microphone output destination switcher 26 and a second microphone output destination switcher 27 that switch the output destination of the audio signal from the microphone 15, a control circuit 28, and operation buttons 29a, 29b, and 29c that constitute an operation unit. Note that the term "mountain side" refers to one direction, such as the south or north side of the tracks, and the term "sea side" refers to the direction opposite to the one direction indicating the mountain side, which is a conventional term in the railway field.

[0014] When an employee makes an announcement inside the train, outside the train, or during business announcements, the microphone 15 collects the employee's voice, converts the voice into an electrical signal, and outputs the signal to the first microphone output destination switching unit 26. The microphone 15 is equipped with a microphone switch that turns the microphone on. The microphone switch is, for example, a PTT (Push to Talk) switch. When the microphone switch is pressed, the microphone 15 converts the voice into an electrical signal and outputs the electrical signal to the first microphone output destination switching unit 26.

[0015] First microphone output destination switching unit 26 includes first terminal 26a connected to microphone 15, second terminal 26b connected to broadcast audio line 34, and third terminal 26c connected to second microphone output destination switching unit 27. The switch of first microphone output destination switching unit 26 selectively connects either second terminal 26b or third terminal 26c to first terminal 26a.

[0016] Second microphone output destination switching unit 27 includes a fourth terminal 27a connected to third terminal 26c, a fifth terminal 27b connected to communication voice line 35, and a sixth terminal 27c connected to amplifier 24. The switch of second microphone output destination switching unit 27 selectively connects either fifth terminal 27b or sixth terminal 27c to fourth terminal 27a.

[0017] Control circuit 28 includes an internal memory that stores programs, various settings, etc., and a calculation unit that performs calculation processing in accordance with the programs, various settings, etc. Control circuit 28 controls the switching of switches in first microphone output destination switching unit 26 and second microphone output destination switching unit 27, for example. Control circuit 28 also controls broadcasting device 20 as a whole.

[0018] Operation button 29a is an in-vehicle operation button that inputs an operation signal to control circuit 28 to switch the audio output destination from microphone 15 to in-vehicle announcements. Operation button 29b is an exterior operation button that inputs an operation signal to control circuit 28 to switch the audio output destination from microphone 15 to in-vehicle announcements. Exterior operation button 29b can also be configured to allow detailed settings such as whether to broadcast from mountain-side exterior speaker 17a, sea-side exterior speaker 17b, or both speakers 17a and 17b. Operation button 29c is a communication operation button that inputs an operation signal to control circuit 28 to switch the audio output destination from microphone 15 to business announcements. Each of operation buttons 29a to 29c is configured with one or more switch components such as a push button or a slide switch.

[0019] The broadcasting device 20 further includes a memory 31 and an audio signal playback unit 32. The memory 31 is a storage element that records audio signals. The memory 31 stores audio signals in audio file format that are used for educational broadcasts (broadcasts that alert passengers) to educate an unspecified number of people and facility users. The audio signals are, for example, audio signals in a digital format (such as MP3 format) and are stored in a file format. For example, in the MP3 format, the frequency band of the audio signal is 20 Hz to 20,000 (20 kHz) Hz. Of these, audio signals used for in-train announcements, outside train announcements, and general-purpose announcements use a band of 300 Hz to 8,000 (8 kHz) Hz, which is relatively easy for listeners to hear.

[0020] The audio signal for announcements on the train (first audio signal) is an audio signal to inform passengers on the train, such as "The next stop is XX station," "There is space between the door and the platform," "Please do not rush onto the train," and "We have noticed an increase in the number of forgotten items. Please be careful not to leave behind items such as umbrellas."

[0021] The memory 31 may be an internal memory built into the audio signal playback unit 32, or may be a removable memory that is detachable from the audio signal playback unit 32. The audio signals stored in the memory 31 vary depending on the section on which the vehicle is operated and are replaced each time. The audio signal playback unit 32 reads out audio files and plays audio signals in accordance with a playback program. For example, the audio signals are played back sequentially in accordance with a playback program corresponding to the route on which the vehicle is traveling.

[0022] Furthermore, the broadcasting device 20 is connected by a plurality of lead wires between the control amplifier 25 of the lead car 11 and the control amplifier 25 of the last car 13. The output amplifier 21 arranged in front of each speaker 16, 17a, 17b is connected to the control amplifier 25 through the lead wires. In other words, the plurality of lead wires extending from the control amplifier 25 of the lead car 11 pass through the intermediate car 12 and connect to the control amplifier 25 of the last car. The plurality of lead wires include a broadcast audio lead wire 34, a communication audio lead wire 35, a broadcast control lead wire 36, an exterior control lead wire 37, and a communication control lead wire 38.

[0023] The broadcast audio wiring line 34 is, for example, an audio signal transmission cable consisting of two cores (e.g., red and black). An audio signal is input to the broadcast audio wiring line 34 from the audio signal reproducing unit 32. The broadcast audio wiring line 34 also receives an audio signal from the microphone 15. The broadcast audio wiring line 34 then outputs the audio signal to the control amplifier 25 in the vehicles 11 and 13 and the amplifier 21 in the vehicle 12.

[0024] The communication voice line 35 is a voice signal transmission cable consisting of two cores. The communication voice line 35 receives an audio signal from the microphone 15. The communication voice line 35 is an audio line connecting the control amplifier 25 of the leading car 11 and the control amplifier 25 of the last car 13, and outputs the audio signal to the amplifier 24 of the communication speakers 18, 19.

[0025] The broadcast control line 36 and the exterior control line 37 are power lines for the amplifier 22 of the output amplifier 21. When the broadcast control line 36 and the exterior control line 37 are active (ON), the amplifier 22 is powered on, enabling broadcasts from the interior speaker 16 and the exterior speakers 17a, 17b. There are two exterior control line 37, one for the mountain-side exterior speaker 17a and one for the sea-side exterior speaker 17b.

[0026] The communication control line 38 is a power supply control line for the amplifiers 24 of the communication speakers 18, 19. When the communication control line 38 is active (ON), the amplifiers 24 are active, enabling broadcasts from the in-vehicle speaker 16 and the exterior speakers 17a, 17b. The communication control line 38 is switched on and off by the control circuit 28. Note that each of the broadcast control line 36, the exterior control line 37, and the communication control line 38 may be configured with multiple lines to enable the exchange of multiple control signals.

[0027] [Operation of a vehicle equipped with a conventional broadcasting device] -In-car announcements In the case of in-car announcements, the audio signal reproducing unit 32 reads out the first audio signal to be reproduced that is stored in the memory 31 according to the program. Then, the audio signal reproducing unit 32 activates the broadcast control line 36 and drives the amplifier 22 of the output amplifier 21. At the same time, the audio signal reproducing unit 32 turns on the first switch 23a of the output destination switching unit 23 through the broadcast control line 36 and turns off the remaining second switch 23b and third switch 23c. Furthermore, the audio signal reproducing unit 32 outputs the first audio signal to be reproduced to the broadcast audio line 34. As a result, the first audio signal to be reproduced is broadcast from the in-car speaker 16.

[0028] For outside broadcasts The exterior announcement is an audio signal for people outside the train, such as passengers waiting on a platform near the stopped train before boarding. For example, it may be something like, "Please move away from the train." For example, if the platform is on the mountain side, the exterior announcement is output from the mountain-side exterior speaker 17a, and if the platform is on the sea side, the exterior announcement is output from the sea-side exterior speaker 17b.

[0029] For external announcements, the microphone 15 is used. The driver, operator, or other personnel turns on the external operation button 29b. This causes the control circuit 28 to connect the first terminal 26a and the second terminal 26b in the first microphone output destination switching unit 26, enabling the audio signal from the microphone 15 to be output to the broadcast audio wiring line 34. At the same time, the control circuit 28 activates the external control wiring line 37 for the external speakers 17a and 17b. At the same time, the control circuit 28 turns on the second switch 23b or the third switch 23c of the output destination switching unit 23. Then, it turns off the remaining switch. Furthermore, the audio signal from the microphone 15 is output to the broadcast audio wiring line 34. As a result, the audio signal from the microphone 15 is broadcast from the mountain-side external speaker 17a or the sea-side external speaker 17b.

[0030] In the case of business announcement broadcasts Service announcements are announcements made between staff members and often have no bearing on passengers. For example, in the case of dual-voltage trains, they are announcements to change the voltage setting when switching from the first electrified section with the first voltage to the second electrified section with the second voltage, or to inform crew members of handover notices.

[0031] In the case of a service announcement, the announcement is typically made via microphone 15, for example, from an operator in the driver's cab of the lead car 11 to an operator in the operator's cab of the last car 13. In this case, the operator or the like turns on the communication operation button 29c in the lead car 11. This causes the control circuit 28 to connect the first terminal 26a to the third terminal 26c in the first microphone output destination switching unit 26. The control circuit 28 also connects the fourth terminal 27a to the fifth terminal 27b in the second microphone output destination switching unit 27. This enables the audio signal from the microphone 15 to be output to the communication audio line 35. The control circuit 28 activates the communication control line 38 and drives the amplifier 24. At the same time, the control circuit 28 connects the fifth terminal 27b, which is connected to the communication audio line 35, to the sixth terminal 27c, which is connected to the amplifier 24, in the second microphone output destination switching unit 27 in the last car 13. As a result, the audio signal from the microphone 15 is broadcast from the rearmost communication speaker 19 in the rearmost car 13.

[0032] [Vehicle equipped with broadcasting device of first embodiment] As shown in Fig. 2, in a vehicle equipped with a broadcasting device of the first embodiment, which is based on a vehicle equipped with a conventional broadcasting device, a broadcast selection unit 40 is added to the control amplifier 25 in, for example, the lead car 11. As shown in Fig. 3, the broadcast selection unit 40 includes a tone detection unit 41, a table 42, and a selection unit 44. The tone detection unit 41 includes a bandpass filter (hereinafter referred to as "BPF") 43. The tone detection unit 41 is disposed between the audio signal reproduction unit 32 and the broadcast audio wiring line 34 and the communication audio wiring line 35. The tone detection unit 41 is also connected to the table 42.

[0033] Memory 31, which stores the audio signals played back by audio signal playback unit 32, stores multiple tone-added audio signals on which tone signals are superimposed. In the first embodiment, the tone signals are composed of a frequency band below the audible range, for example, a frequency band of 200 Hz or less that is difficult to hear. They are also composed of a frequency band of 20 Hz or more. This is because frequencies below 20 Hz are cut off in digital signals such as MP3 format and may be output as noise. Furthermore, the tone signals exclude commercial power supply frequencies (50 Hz in the Kanto region and 60 Hz in the Kansai region, including deviations allowed by the standard) and their multiple harmonics, which are their multiples. This makes it difficult for the tone signals to interfere with the power supply frequency, thereby minimizing a decrease in the accuracy of tone signal detection.

[0034] In vehicles equipped with conventional broadcasting equipment, audio signals for in-car announcements (first audio signal) were stored in memory 31, but after the modification, audio signals for outside the vehicle announcements (second audio signal, third audio signal) and audio signals for business announcements (fourth audio signal) are also stored in memory 31.

[0035] The second audio signal is an audio signal output from the mountain-side exterior speaker 17a to educate people on the mountain-side platform, etc. The third audio signal is an audio signal output from the sea-side exterior speaker 17b to educate people on the sea-side platform, etc. The business announcement audio signal (fourth audio signal) is an audio signal output from announcement speakers 18, 19 for one staff member to inform other staff members of their work.

[0036] The memory 31 stores the first to fourth tone-attached audio signals on which the tone signals are superimposed. The memory 31 can be of the same specifications as the memory 31 used in vehicles equipped with conventional broadcasting devices. Such tone-attached audio signals can be reproduced using the same audio signal reproduction unit 32 as that used in vehicles equipped with conventional broadcasting devices.

[0037] Tone signals include, for example, a tone signal of a first frequency, a second tone signal of a second frequency different from the first frequency, a third tone signal of a third frequency different from the first and second frequencies, and a fourth tone signal of a fourth frequency different from the first, second, and third frequencies. Furthermore, a synthesized tone signal obtained by synthesizing multiple tone signals of different frequencies may be used. Such tone signals are superimposed on an audio signal. The tone signal may be superimposed over the entire time axis of an audio signal, or may be superimposed only on the beginning of the audio signal. Furthermore, the tone signal may be superimposed intermittently on an audio signal. As long as the tone signal is superimposed over the entire time axis of an audio signal, the tone signal can be detected no matter where playback is started.

[0038] For example, the first tone signal is a first control identifier associated with the in-vehicle speaker 16 as the output destination of the audio signal. The second tone signal is a second control identifier associated with the mountain-side exterior speaker 17a as the output destination of the audio signal. The third tone signal is a third control identifier associated with the sea-side exterior speaker 17b as the output destination of the audio signal. Furthermore, the fourth tone signal is a fourth control identifier associated with the communication speakers 18, 19 as the output destination of the audio signal.

[0039] The tone detection unit 41 detects a tone signal of a predetermined frequency using the BPF 43. The tone detection unit 41 refers to the table 42 to determine which boom signal the frequency detected by the BPF 43 corresponds to.

[0040] The table 42 is stored in a memory device. The table 42 associates tone signals with the speakers to which they are output. For example, in the table 42, the first tone signal is associated with the in-vehicle speaker 16, the second tone signal is associated with the mountain-side exterior speaker 17a, the third tone signal is associated with the sea-side exterior speaker 17b, and the fourth tone signal is associated with the communication speakers 18 and 19.

[0041] The selector 44 receives the tone-attached audio signal from the audio signal reproducing unit 32. The selector 44 is connected to the lead lines 34 to 38. The selector 44 includes a cut filter that cuts out the tone signal from the tone-attached audio signal before outputting the audio signal to the broadcast audio lead line 34 and the communication audio lead line 35. By removing the tone signal from the tone-attached audio signal in this way, deterioration in the sound quality of the audio broadcast from the speakers 16, 17a, 17b, 18, and 19 can be suppressed.

[0042] When tone detector 41 detects the first tone signal, selector 44 removes the first tone signal from the audio signal with the first tone, and outputs the first audio signal to broadcast audio line 34 for in-car announcement. Tone detector 41 also activates (ON) broadcast control line 36 via control circuit 28 using selector 44, thereby driving amplifier 22.

[0043] When the tone detection unit 41 detects the second tone signal or the third tone signal, the selection unit 44 removes the second tone signal or the third tone signal from the audio signal with the second tone, and outputs the second audio signal or the third audio signal to the broadcast audio wiring line 34 for use in the mountain side exterior broadcast or the sea side exterior broadcast. The tone detection unit 41 also activates (ON) the line for the mountain side exterior speaker 17a or the line for the sea side exterior speaker 17b via the control circuit 28 in the selection unit 44, and drives the amplifier 22.

[0044] When the tone detector 41 detects the fourth tone signal, the selector 44 removes the fourth tone signal from the audio signal with the fourth tone, and outputs the fourth audio signal to the audio communication line 35 for use in a business announcement broadcast. The tone detector 41 also activates (ON) the audio communication line 38 via the control circuit 28 using the selector 44, thereby driving the amplifier 24.

[0045] [Operation of a vehicle equipped with the broadcasting device of the first embodiment] -In-car announcements In the case of an in-car announcement, the audio signal reproducing unit 32 reads out the first tone-attached audio signal to be reproduced, which is stored in the memory 31. The tone detecting unit 41 determines that the first tone signal is the first tone signal from the frequency of the tone signal by referring to the table 42. The tone detecting unit 41 then removes the first tone signal from the first tone-attached audio signal using the selecting unit 44, and outputs the first audio signal to the broadcast audio wiring line 34 for in-car announcement. The tone detecting unit 41 also activates the broadcast control wiring line 36 using the selecting unit 44 via the control circuit 28, thereby driving the amplifier 22 of the output amplifier 21. At the same time, the tone detecting unit 41 turns on the first switch 23a of the output destination switching unit 23 using the selecting unit 44, and turns off the remaining second switch 23b and third switch 23c. As a result, the audio signal to be reproduced is broadcast from the in-car speaker 16.

[0046] When making an announcement on the train using the microphone 15, the train attendant turns on the in-train operation button 29a. This causes the control circuit 28 to connect the first terminal 26a and the second terminal 26b in the first microphone output destination switching unit 26, enabling the audio signal from the microphone 15 to be output to the broadcast audio wiring line 34. The control circuit 28 activates the broadcast control wiring line 36 and drives the amplifier 22. At the same time, the control circuit 28 turns on the first switch 23a of the output destination switching unit 23 via the broadcast control wiring line 36, and turns off the remaining switches, the second switch 23b and the third switch 23c. This causes the audio signal from the microphone 15 to be broadcast from the in-train speaker 16.

[0047] For outside broadcasts In the case of an outside broadcast, the audio signal reproducing unit 32 reads out the second tone-attached audio signal or the third tone-attached audio signal to be reproduced, which is stored in the memory 31. The tone detecting unit 41 determines whether the tone signal is the second tone signal or the third tone signal from the frequency of the tone signal by referring to the table 42. The tone detecting unit 41 removes the second tone signal or the third tone signal from the second tone-attached audio signal or the third tone-attached audio signal using the selecting unit 44, and outputs the second audio signal or the third audio signal to the broadcast audio wiring line 34 for use in an outside broadcast.

[0048] Here, the exterior speakers include a mountain-side exterior speaker 17a and a sea-side exterior speaker 17b. When the tone signal is a second tone signal and the output destination is the mountain-side exterior speaker 17a, the tone detection unit 41 activates the exterior control line 37 of the mountain-side exterior speaker 17a via the selection unit 44 through the control circuit 28. When the tone signal is a third tone signal and the output destination is the sea-side exterior speaker 17b, the tone detection unit 41 activates the exterior control line 37 of the sea-side exterior speaker 17b via the selection unit 44 through the control circuit 28. At the same time, the tone detection unit 41 activates the second switch 23b or the third switch 23c of the output destination switching unit 23 via the selection unit 44. The remaining switches are then turned off. As a result, the second audio signal or the third audio signal to be reproduced is broadcast from the mountain-side exterior speaker 17a or the sea-side exterior speaker 17b.

[0049] To make an external announcement using the microphone 15, the driver, operator, or the like turns on the external operation button 29b. This causes the control circuit 28 to connect the first terminal 26a and the second terminal 26b in the first microphone output destination switching unit 26, enabling the audio signal from the microphone 15 to be output to the broadcast audio wiring line 34. At the same time, the control circuit 28 activates the external control wiring line 37 for the external speakers 17a and 17b. At the same time, the control circuit 28 turns on the second switch 23b or the third switch 23c of the output destination switching unit 23. Then, it turns off the remaining switch. Furthermore, the audio signal from the microphone 15 is output to the broadcast audio wiring line 34. This causes the audio signal from the microphone 15 to be broadcast from the mountain-side external speaker 17a or the sea-side external speaker 17b.

[0050] In the case of business announcement broadcasts In the case of a service announcement broadcast, the audio signal reproduction unit 32 reads out the audio signal with the fourth tone to be reproduced, which is stored in the memory 31. The tone detection unit 41 determines that the tone signal is the fourth tone signal based on its frequency by referencing the table 42. The tone detection unit 41 then removes the fourth tone signal from the audio signal with the fourth tone using the selection unit 44, and outputs the fourth tone signal to the service announcement broadcast line 35. The tone detection unit 41 also activates the announcement control line 38 using the selection unit 44 via the control circuit 28, and the status is input to the control circuit 28. The control circuit 28 then connects the fifth terminal 27b, which is connected to the announcement voice line 35, and the sixth terminal 27c, which is connected to the amplifier 24, in the second microphone output destination switching unit 27 of the last car 13. As a result, the fourth audio signal is broadcast from the last car announcement speaker 19.

[0051] An operational announcement may be made via microphone 15, for example, from an operator in the driver's cab of the lead car 11 to an operator in the operator's cab of the last car 13. In this case, the operator or the like turns on the communication operation button 29c in the lead car 11. This causes the control circuit 28 to connect the first terminal 26a to the third terminal 26c in the first microphone output destination switching unit 26. The control circuit 28 also connects the fourth terminal 27a to the fifth terminal 27b in the second microphone output destination switching unit 27. This enables the audio signal from the microphone 15 to be output to the communication audio line 35. The control circuit 28 activates the communication control line 38 and drives the amplifier 24. At the same time, the control circuit 28 connects the fifth terminal 27b, which is connected to the communication audio line 35, to the sixth terminal 27c, which is connected to the amplifier 24, in the second microphone output destination switching unit 27 in the last car 13. As a result, the audio signal from the microphone 15 is broadcast from the rearmost communication speaker 19 in the rearmost car 13.

[0052] [Effects of the first embodiment] The first embodiment described above can provide the following effects. (1-1) The tone signals superimposed on each audio signal correspond to the speakers 16, 17a, 17b, 18, and 19 to which the audio signal is to be output. The tone detection unit 41 detects the tone signal and broadcasts the audio signal from the speakers 16, 17a, 17b, 18, and 19 corresponding to the tone signal. By removing the tone signal when outputting from the speaker, degradation of sound quality can be suppressed. Furthermore, by using the tone signal, speaker switching can be automated not only for in-car announcements but also for outside announcements and business announcements, reducing operational errors such as incorrect output.

[0053] When converting such a conventional vehicle into a vehicle of the first embodiment, it is possible to reuse the existing speakers 16, 17a, 17b, 18, 19, output amplifier 21, and control amplifier 25. The vehicle conversion is mainly performed by adding only broadcast selection unit 40, making the conversion work easy.

[0054] (1-2) Table 42 can manage the correspondence between the output destination speakers 16, 17a, 17b, 18, and 19 and the frequency of the tone signal. Therefore, by referring to table 42, tone detection unit 41 can select the output destination based on the frequency of the tone signal, and selection unit 44 can select the output destination.

[0055] (1-3) By storing a tone-added audio signal in the memory 31, the audio signal can be broadcast from the speakers 16, 17a, 17b, 18, and 19 corresponding to the tone signal without selecting the output destination speakers 16, 17a, 17b, 18, and 19. If the memory 31 is replaceable with respect to the audio signal reproducing unit 32, the tone-added audio signal to be broadcast can be easily changed. Alternatively, even if the memory 31 is fixed with respect to the audio signal reproducing unit 32, if the tone-added audio signal is rewritable, the tone-added audio signal to be broadcast can be easily changed.

[0056] (1-4) As long as a tone signal is superimposed over the entire time axis of a single audio signal, it can be detected regardless of the position at which playback is started, and the output destination can be selected. The tone signal can be made inaudible or difficult to hear by passengers and other listeners by configuring it at 200 Hz or less. The tone signal is configured to exclude overtones consisting of the commercial power frequency (Kanto: 50 Hz / Kansai: 60 Hz, including deviations allowed by the standard) and its harmonics. This makes it less likely for the tone signal to interfere with the power frequency, thereby preventing a decrease in the accuracy of tone signal detection.

[0057] [Vehicle equipped with broadcasting device of second embodiment] 4 and 5, the control amplifier 25 includes the operation buttons 29a, 29b, and 29c as described above. The control amplifier 25 also includes a tone generator 51. The tone generator 51 includes a table similar to the above-described table 42. When an operation signal is input from the operation buttons 29a, 29b, and 29c, the tone generator 51 generates a tone signal corresponding to the output indicated by the operation signal.

[0058] The memory 31 stores audio signals without tone signals superimposed thereon. When each audio signal is read by the audio signal reproducing unit 32, it is output to the line 56. The tone signal generated by the tone generating unit 51 is superimposed on the audio signal output from the audio signal reproducing unit 32.

[0059] The memory 31 can also store a tone-added audio signal on which a tone signal is superimposed. In this case, when the audio signal reproducing unit 32 reproduces the tone-added audio signal, the tone generating unit 51 is not used. In the second embodiment, there is one line 56, which is an audio signal transmission cable. The tone-added audio signal is input to the line 56.

[0060] In each of the cars 11 to 13, the output amplifier 21 includes a broadcast selection unit 40. This broadcast selection unit 40 also includes a tone detection unit 41, a table 42, and a selection unit 44. The tone detection unit 41 includes a BPF 43. By referencing the table 42, the tone detection unit 41 determines which boom signal the frequency of the tone signal in the tone-accompanied audio signal transmitted from the train line 56 corresponds to. The selection unit 44 then drives the amplifier 22 to broadcast the audio signal from the corresponding speaker 16, 17a, 17b, 18, or 19.

[0061] The control amplifier 25 also has an amplifier 24 in the preceding stage of the communication speakers 18, 19, and a broadcast selection unit 40 in the preceding stage of the amplifier 24. In this broadcast selection unit 40, a selection unit 44 drives the amplifier 24 to broadcast the fourth audio signal from the corresponding communication speaker 18, 19.

[0062] -In-car announcements In the case of an in-car announcement, the audio signal reproducing unit 32 reads out the first audio signal to be reproduced, which is stored in the memory 31. Here, a control identifier indicating that the output destination is to the in-car speaker 16 according to the first audio signal or the reproduction program is input to the tone generating unit 51. Then, the tone generating unit 51 generates a first tone signal, outputs it to the train line 56, and superimposes it on the first audio signal. Also, when an in-car announcement is to be made using the microphone 15, the in-car operation button 29a is turned on. Then, the tone generating unit 51 generates a first tone signal, outputs it to the train line 56, and superimposes the first tone signal on the first audio signal from the microphone 15. As a result, the first audio signal becomes a first tone-added audio signal in the train line 56. Also, the audio signal reproducing unit 32 reproduces the first tone-added audio signal stored in the memory 31 and outputs it to the train line 56. When the tone detector 41 in each vehicle detects the first tone signal, the selector 44 selects the output destination as the in-vehicle speaker 16, and the first audio signal is broadcast from the in-vehicle speaker 16.

[0063] For outside broadcasts In the case of an exterior broadcast, the audio signal playback unit 32 reads out the second audio signal or the third audio signal to be played back, which is stored in the memory 31. Here, in the case of the second audio signal, a control identifier indicating that the output destination is to be the mountain-side exterior speaker 17a in accordance with the second audio signal or the playback program is input to the tone generation unit 51. In the case of the third audio signal, a control identifier indicating that the output destination is to be the sea-side exterior speaker 17b in accordance with the third audio signal or the playback program is input. Alternatively, the exterior operation button 29b is operated. Then, the tone generation unit 51 generates the second tone signal or the third tone signal, outputs it to the train line 56, and superimposes the second tone signal on the second audio signal, or superimposes the third tone signal on the third audio signal.

[0064] When using the microphone 15 to make an external announcement for the mountain side or sea side, the external operation button 29b is turned on. At this time, the output destination is also set to mountain side or sea side. The tone generator 51 then generates a second tone signal for the mountain side, and a third tone signal for the sea side, and outputs these to the train line 56. The second tone signal is then superimposed on the second audio signal from the microphone 15. The third tone signal is also superimposed on the third audio signal from the microphone 15. As a result, the third audio signal becomes an audio signal with a third tone in the train line 56.

[0065] As a result, the second audio signal becomes the audio signal with the second tone, and the third audio signal becomes the audio signal with the third tone in the draw line 56. In addition, the audio signal reproducing unit 32 reproduces the audio signal with the second tone or the audio signal with the third tone stored in the memory 31, and outputs it to the draw line 56.

[0066] When the tone detector 41 in each vehicle detects the second tone signal, the selector 44 selects the output destination as the mountain-side exterior speaker 17a, and broadcasts the second audio signal from the mountain-side exterior speaker 17a. When the tone detector 41 in each vehicle detects the third tone signal, the selector 44 selects the output destination as the sea-side exterior speaker 17b, and broadcasts the third audio signal from the sea-side exterior speaker 17b.

[0067] In the case of business announcement broadcasts In the case of an external announcement, the audio signal reproducing unit 32 reads out the fourth audio signal to be reproduced, which is stored in the memory 31. Here, in the case of the fourth audio signal, a control identifier indicating that the output destination is to the announcement speakers 18, 19 according to the fourth audio signal or the reproduction program is input to the tone generating unit 51. The tone generating unit 51 then generates a fourth tone signal, outputs it to the train line 56, and superimposes it on the fourth audio signal. In addition, in the case of an external announcement using the microphone 15, the announcement operation button 29c is turned on. Then, the tone generating unit 51 generates a first tone signal and superimposes the fourth tone signal on the fourth audio signal from the microphone 15. As a result, the fourth audio signal becomes an audio signal with a fourth tone. In addition, the audio signal reproducing unit 32 reproduces the fourth audio signal with a fourth tone stored in the memory 31 and outputs it to the train line 56. When the tone detector 41 in each control amplifier 25 detects the fourth tone signal, the selector 44 selects the output destination as the announcement speaker 18, 19, and the announcement speaker 18, 19 broadcasts the fourth audio signal.

[0068] [Effects of the second embodiment] The second embodiment described above can provide the following advantages. (2-1) By providing the tone generating unit 51, a tone signal can be superimposed on the audio signal stored in the memory 31. The audio signal stored in the memory 31 can be the same as in the past. The superimposition of a tone signal according to the output destination can be based on a control identifier stored in the memory 31, or can be performed based on the operation of the operation buttons 29a, 29b, and 29c.

[0069] (2-2) By providing the tone generating unit 51, a tone signal can be superimposed on the audio signal input from the microphone 15. The output destination of the audio signal input from the microphone 15 can be selected using the operation buttons 29a, 29b, and 29c, and a tone signal corresponding to the selected destination can be superimposed on the audio signal input from the microphone 15.

[0070] (2-2) When an audio signal with a tone is stored in memory 31, the tone signal can be detected by tone detection unit 41 provided in front of each speaker 16, 17a, 17b, 18, and 19 without using tone generation unit 51, and the audio signal can be broadcast from the speaker indicated by the detected tone signal.

[0071] [First broadcast setting example] FIG. 6 shows examples of broadcast settings. For example, broadcast setting A is a setting that sets the driver's cab communication speaker 18 as the output destination and is associated with a first tone signal A of a first frequency (e.g., 40 Hz). Broadcast setting B is a setting that sets the driver's cab communication speaker 18 and the in-vehicle speaker 16 as the output destination and is associated with a second tone signal B of a second frequency (e.g., 70 Hz) different from the first frequency. Broadcast setting C is a setting that sets the mountain-side exterior speaker 17a and the sea-side exterior speaker 17b as the output destination and is associated with a third tone signal C that combines the first and second frequencies. Furthermore, a tone signal of "none" is set as the output destination to "none." This method allows four patterns of broadcast settings to be created using two frequencies. In addition, broadcast setting B and broadcast setting C also allow multiple output destinations to be associated with one tone signal, allowing simultaneous broadcasting to multiple output destinations.

[0072] 7 is a diagram showing another broadcast setting example. In this broadcast setting example, eight patterns can be set using three frequencies. Here, a first tone signal associated with a first frequency f1, a second tone signal associated with a second frequency f2, and a third tone signal associated with a third frequency f3 are used.

[0073] For example, in "State 0," the three tone signals are "absent," and the system is set to in-car announcements. The speaker SP1 installed inside the vehicle is set as the output destination. In "State 1," the third tone signal is "present," the first tone signal and the second tone signal are "absent," and the system is set to ocean-side outside announcements. The speaker SP2 installed on the ocean side is set as the output destination. According to the broadcast settings shown in FIG. 7, if the number of tone signals used is increased, it becomes possible to set various combinations of speakers SP. This also makes it possible to broadcast simultaneously in multiple locations.

[0074] [Modification] The broadcasting device can also be implemented by further modifying it as appropriate as follows: In addition to the above-described embodiments, the broadcasting device may be implemented in a form that combines, for example, the following modified examples, or at least two mutually consistent modified examples.

[0075] If two types of tone signals are used, four different broadcast destinations can be set. If three types of tone signals are used, eight different broadcast destinations can be set. If one type of tone signal is used, two different broadcast destinations can be set.

[0076] The tone detector 41 may use a detection method that uses a discrete Fourier transform, a fast Fourier transform, or the like, in addition to the BPF 43. When using an audio signal with a tone, the tone signal may be broadcast from a speaker without being removed.

[0077] The vehicle may be a train or a bus made up of multiple vehicles connected together. [Explanation of symbols]

[0078] 11-13...vehicle, 15...microphone, 16...speaker, 16...in-vehicle speaker, 17...speaker for rear end communication, 17a...mountain side exterior speaker, 17b...sea side exterior speaker, 18...front end communication speaker, 19...rear end communication speaker, 20...broadcasting device, 21...output amplifier, 22...amplifier, 23...output destination switching unit, 23a...first switch, 23b...second switch, 23c...third 3 switch, 24...amplifier, 25...control amplifier, 26...first microphone output destination switching unit, 26a...first terminal, 26b...second terminal, 26c...third terminal, 27...second microphone output destination switching unit, 27a...fourth terminal, 27b...fifth terminal, 27c...sixth terminal, 28...control circuit, 29a...in-vehicle operation button, 29b...out-vehicle operation button, 29c...contact operation button, 40...broadcast selection unit.

Claims

1. A vehicle broadcasting device equipped with a plurality of speakers, a tone detection unit that detects a tone signal from a tone-added audio signal in which the tone signal is superimposed on an input audio signal; a selection unit that selects the speaker that will be the output destination, The selection unit selects, as the output destination, the speaker corresponding to the tone signal detected by the tone detection unit. Vehicle broadcasting device.

2. a table that associates each of a plurality of tone signals having different frequencies with the speaker to which the tone signals are output, The selection unit refers to the table and selects, as the output destination, the speaker corresponding to the tone signal detected by the tone detection unit.

2. The vehicle broadcasting device according to claim 1.

3. There are multiple types of audio signals, a memory for storing a plurality of types of tone-added audio signals in which the tone signal corresponding to the type of the audio signal is superimposed on each of the audio signals; an audio signal reproducing unit that reproduces the audio signal with the tone.

3. The vehicle broadcasting device according to claim 1 or 2.

4. a memory for storing a plurality of types of said audio signals; an audio signal reproducing unit that reproduces the audio signal; a tone generating unit that generates the tone signal, The tone-added audio signal is configured by superimposing the tone signal on the audio signal.

3. The vehicle broadcasting device according to claim 1 or 2.

5. The frequency band constituting the tone signal is 20 Hz or more and 200 Hz or less.

2. The vehicle broadcasting device according to claim 1.

6. The tone signal is configured in a band excluding the power supply frequency and its multiples.

6. The vehicle broadcasting device according to claim 5.

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