JP2009027479A - Power line communication acoustic playback apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power line communication acoustic playback apparatus which reduces interference of noise and is made compact. <P>SOLUTION: The power line communication acoustic playback apparatus comprises: a first casing 2 and a second casing 3 which are connected by a hinge part 1 provided in a pedestal end part so as to be folded; a speaker part 4 provided within the first casing 2; a digital amplifier part 5 provided within the first casing 2 and connected to the speaker part 4; a power line communication part 6 provided within the second casing 3 and connected to a power line for receiving an audio signal via the power line; and a power source part 7 provided within the second casing 3 for supplying power to the digital amplifier part 5 and the power line communication part 6, wherein the first casing 2 and the second casing 3 are each electromagnetic wave shield case. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a power line communication sound reproducing apparatus that receives and reproduces an audio signal via a power line.

Conventionally, for example, a speaker system described in Patent Document 1 has been proposed as a technique for transmitting audio data from an audio data transmission device (information transmission device) such as a CD player or a DVD player to a plurality of speaker devices and reproducing the data. ing.
In this speaker system, audio data is transmitted from a single audio data transmitter to a plurality of speaker devices installed wirelessly. Thereby, different types of audio data can be played back by the respective speaker devices. In this speaker device, a speaker and a control unit are built in a housing.

  On the other hand, in recent years, it has been studied to perform data communication between power line communication devices via a power line wired in a building such as a house. For example, research has been conducted on data communication such as audio data and video data between power line communication apparatuses such as audio devices using a power line of a house (see, for example, Patent Document 2).

JP 2001-275194 A JP 2000-216752 A

The following problems remain in the conventional technology.
To construct a speaker device that receives and reproduces an audio signal using power line communication, in the case of an active speaker with a built-in amplifier function, in addition to the speaker unit, a power line communication module, a power supply module, and an audio amplifier are provided. Must be built in. In order to improve the convenience of the active speaker, downsizing is required. Therefore, it is preferable to use a digital amplifier that is efficient in power and can be downsized as an audio amplifier. This digital amplifier has a function of sampling and quantizing a small signal at high speed, amplifies the digital signal, and converts it into an analog signal. However, since this digital amplifier performs high-speed sampling and digital control, there is a problem that a large amount of high-frequency noise in the MHz band is generated. That is, the high frequency noise has a disadvantage that the communication sensitivity of the power line communication module to be mounted is deteriorated. On the other hand, there is also a disadvantage that audio characteristics are deteriorated due to interference with the digital amplifier due to high frequency signal noise generated by the power line communication module. Furthermore, the interference of these noises affects through the connected signal lines, common power ground lines and spaces. In particular, interference due to spatial coupling becomes a problem when miniaturizing the apparatus. As a countermeasure, it is possible to reduce interference by separately providing a member for individually shielding the digital amplifier and the power line communication module. In this case, however, a space for installing at least two shield members is required. There are inconveniences that make it difficult to reduce the size and increase costs.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a power line communication sound reproducing device that can reduce noise interference and can be miniaturized.

  The present invention employs the following configuration in order to solve the above problems. That is, the power line communication sound reproducing device of the present invention is provided in the first housing and the first housing and the second housing that are foldably connected by the hinge portion provided at the base end portion. A speaker unit, a digital amplifier unit provided in the first casing and connected to the speaker unit, and a power line provided in the second casing and connected to the power line for receiving an audio signal via the power line A communication unit, and a power supply unit that is provided in the second housing and supplies power to the digital amplifier unit and the power line communication unit, and the first housing and the second housing are respectively It is an electromagnetic wave shielding case.

  In this power line communication sound reproducing apparatus, the digital amplifier unit and the power line communication unit are housed in separate casings having a shell structure, and these casings are respectively electromagnetic wave shielding cases. It can reduce that the noise of an amplifier part and a power line communication part is shielded, and interferes with each other's function. This makes it possible to transmit not only audio signals but also device control information and meta information (such as song titles and artist names) with high efficiency and high quality. Further, since the casing itself has a shielding function, it is not necessary to attach a shielding member individually, and the entire apparatus can be reduced in size.

  Further, the power line communication sound reproducing device of the present invention operates only the power line communication unit when the first casing and the second casing are closed in a folded state, and the first casing and A switching mechanism capable of switching to operate the digital amplifier unit when the second housing is opened is provided. That is, in this power line communication sound reproducing apparatus, when the first casing and the second casing are folded such as when stored or not in use, only the power line communication unit is operated by the switching mechanism to perform power line communication. Since the digital amplifier section is stopped and not operating, power line communication can be performed with high quality. In particular, when performing channel estimation of a power line transmission line in power line communication, it is possible to select a channel without noise and to estimate the power line transmission line with high quality. Thereby, the narrow frequency band given to power line communication can be used effectively. In addition, since the switching mechanism controls the start / stop of the digital amplifier unit in conjunction with the folding opening / closing operation, there is no need for cumbersome operations for separate switch control, and it functions when the digital amplifier unit is needed. And can be used without the user's awareness.

  In the power line communication sound reproducing apparatus of the present invention, the digital amplifier unit is housed on the distal end side of the first housing, and the power line communication unit is housed on the distal end side of the second housing. It is characterized by. That is, in this power line communication sound reproducing apparatus, the digital amplifier unit and the power line communication unit are respectively housed at the distal end sides of the first casing and the second casing, so that in the opened state, The distance to the power line communication unit is maximized, and the influence of noise can be further reduced. For this reason, it is not necessary to use an expensive electromagnetic wave shielding case for the first housing and the second housing, and a merit can be obtained in terms of cost and shape.

The present invention has the following effects.
That is, according to the power line communication sound reproducing apparatus according to the present invention, since the digital amplifier unit and the power line communication unit are respectively housed in separate housings of the electromagnetic wave shielding case, each other's noise is shielded and high quality is achieved. Communication and audio characteristics can be obtained. Further, since the casing itself has a shielding function, it is not necessary to attach a shielding member individually, and the entire apparatus can be reduced in size. Therefore, it is possible to obtain an active speaker that is low in cost and small in size and has good communication quality and audio characteristics.

  Hereinafter, an embodiment of a power line communication sound reproducing apparatus according to the present invention will be described with reference to FIGS.

  The power line communication sound reproduction device of the present embodiment receives an audio signal transmitted from an audio signal transmission device such as a CD reproduction device via a power line that is wired to a general house or the like and supplies power to a plurality of electronic devices. This is an active speaker that reproduces and outputs and has an amplifier function. As shown in FIGS. 1 and 2, the power line communication sound reproducing device includes a first casing 2 and a second casing 3 that are foldably connected by a hinge portion 1 provided at a base end portion, and A speaker unit 4 provided in the first housing 2, a digital amplifier unit 5 provided in the first housing 2 and connected to the speaker unit 4, and a power line provided in the second housing 3 And a power line communication unit 6 that receives an audio signal via the power line, and a power supply unit 7 that is provided in the second housing 3 and supplies power to the digital amplifier unit 5 and the power line communication unit 6. ing.

Each of the first casing 2 and the second casing 3 is an electromagnetic shielding case. This electromagnetic wave shielding case is a case in which a metal thin film is formed on the surface or the inner surface of a metal case or a resin case body, for example, and has a function of absorbing, attenuating and reflecting electromagnetic waves and blocking them.
The digital amplifier unit 5 is housed on the front end side of the first housing 2, and the power line communication unit 6 is housed on the front end side of the second housing 3.
In addition, the said hinge part 1 has a well-known hinge function.

  Further, the power line communication sound reproducing device operates only the power line communication unit 6 when the first casing 2 and the second casing 3 are closed in the folded state, and the first casing 2 and the second casing 3 A switching mechanism 8 capable of switching to operate the digital amplifier unit 5 when the housing 3 is opened is provided. The switching mechanism 8 is electrically connected between the digital amplifier unit 5 and the power supply unit 7, and turns on / off the digital amplifier unit 5 when the first casing 2 and the second casing 3 are opened and closed. It is a switch to make.

  That is, as shown in FIG. 1, the switching mechanism 8 is provided in a protruding state at the distal end portion of the first casing 2 when the first casing 2 and the second casing 3 are opened. Then, the digital amplifier unit 5 is turned on. Further, as shown in FIG. 2, the switching mechanism 8 is pushed in contact with the tip of the second housing 3 when the first housing 2 and the second housing 3 are closed in the folded state. Thus, the digital amplifier unit 5 is turned off. As the switching mechanism 8, any other mechanism may be employed as long as the digital amplifier unit 5 is turned on / off in accordance with opening / closing of the first housing 2 and the second housing 3. .

The power supply unit 7 is connected to an AC cable 9 that extends from the second housing 3 to the outside and can be connected to a power line.
The power line communication unit 6 divides data such as an audio signal into a plurality of subcarriers, for example, and receives and transmits the data via a power line at a carrier frequency corresponding to the plurality of subcarriers. (Not shown). Similarly, an audio signal transmission device such as a CD playback device includes a data reception device and a data transmission device.
The power line communication unit 6 is connected to an AC cable 9 via a power supply unit 7.

  The digital amplifier unit 5 has a function of sampling and quantizing a small signal such as an audio signal received by the power line communication unit 6 at high speed, amplifies the digital signal, and converts it into an analog signal. The signal transmitted / received between the power line communication unit 6 and the audio signal transmitting device such as a CD playback device via the power line includes the control information and meta information (song title and artist name) of the device together with the audio signal to be played back. Etc.).

  In the power line communication sound reproducing apparatus of the present embodiment, an information display unit such as a liquid crystal display capable of displaying the meta information or the like may be provided on the surface of the first casing 2 or the second casing 3. Absent. In this power line communication sound reproducing apparatus, the audio signal transmitting apparatus such as a CD reproducing apparatus may be provided with a function for transmitting control signals such as reproduction, stop, fast forward, and fast reverse through the power line by the power line communication unit 6. Absent. In this case, an operation button or the like for sending these control signals may be provided on the surface of the first casing 2 or the second casing 3.

  The power line communication unit 6 and an audio signal transmission device such as a CD playback device perform channel estimation of a transmission line for performing power line communication, select a good channel and set the transmission line between them as a transmission line. However, this transmission line setting is performed when the digital amplifier unit 5 is stopped by the switching mechanism 8 particularly when the first casing 2 and the second casing 3 are folded and closed. To be done.

  For example, as shown in FIG. 3, when the digital amplifier unit 5 is stopped by the switching mechanism 8 when it is closed (step S1), channel estimation of the transmission path is performed (step S2). When a good channel is selected, the power line communication unit 6 and an audio signal transmission device such as a CD playback device set the channel of the transmission path used for power line communication (step S3).

  The detailed flow of this transmission path estimation and setting (steps S2 and S3), and transmission / reception and reproduction of audio signals will be described below with reference to FIGS. Here, processing performed between a data transmission device in an audio signal transmission device such as a CD reproduction device and a data reception device of a power line communication sound reproduction device will be described.

First, in an audio signal transmission apparatus such as a CD playback apparatus, the data transmission apparatus continuously changes the frequency of the pilot tone p to f1, f2, f3, and f4 as shown in FIGS. Then, the data is transmitted to the data receiving device of the power line communication sound reproducing device via the power line (step S01).
Here, a case where notches n1 and n2 as shown in FIG. 4B are generated in the frequency band received by the data receiving device due to the influence of other electrical equipment connected to the power line afterward will be described. To do.

The data receiving device of the power line communication sound reproducing device receives the pilot tone transmitted from the data transmitting device via the power line (step S02).
Next, the data receiving apparatus detects whether or not a notch exists in the frequency band used for the received pilot tone (step S03).
Since notches n1 and n2 as shown in FIG. 4B are generated in the communication environment of the power line between the data transmitting apparatus and the data receiving apparatus, pilot tones received by the data receiving apparatus (FIG. 4). (See (c)) also causes distortion corresponding to the notches n1 and n2.

Next, the data receiving apparatus selects a channel used in power line communication so as to avoid the frequency band in which the detected notch exists (step S04).
Then, the data reception device transmits the channels c1, c2, c3, and c4 (see FIG. 4D) in the frequency band in which the selected notch does not exist as “channel information” to the data transmission device via the power line. (Step S05).

The transmitted “channel information” is received by the data transmitting apparatus (step S06).
Based on the received “channel information”, the data transmission apparatus sets transmission channels c1, c2, c3, and c4 (see FIG. 4D) in frequency bands that do not have a notch and are used in power line communication (see FIG. 4D). Step S07).

The data transmission apparatus performs processing to distribute the original data that is specified and distribute it in each channel to be transmission data so that power line communication is performed using the set transmission channels cl, c2, c3, and c4. (Step S08).
The data transmitting apparatus transmits the original data arranged in the transmission channel having no notch as transmission data to the data receiving apparatus via the power line (step S09).

The data receiving apparatus receives the transmission data via the power line (step S10).
Next, the data receiving apparatus restores the original data arranged in the received transmission channel having no notch (step S11).
The data receiving apparatus reproduces the restored “original data” (step S12). The reproduced “original data” is amplified by the digital amplifier unit 5 through the above-described processing, and is reproduced and output by the speaker unit 4.

  In the power line communication sound reproducing apparatus of the present embodiment, the digital amplifier unit 5 and the power line communication unit 6 are housed in separate housings having a shell structure, and these housings are electromagnetic wave shielding cases, and thus have a shielding function. It can reduce that the noise of the digital amplifier part 5 and the power line communication part 6 is each shielded by each housing | casing, and interferes with a mutual function. Thereby, it is possible to transmit not only the audio signal but also the control information and meta information of the apparatus with high efficiency and high quality. Further, since the casing itself has a shielding function, it is not necessary to attach a shielding member individually, and the entire apparatus can be reduced in size.

  When the first casing 2 and the second casing 3 are folded, such as when stored or not in use, only the power line communication unit 6 is operated by the switching mechanism 8 to perform power line communication, and the digital amplifier unit Since 5 is stopped and not operating, power line communication is possible with high quality. In particular, when performing channel estimation of a power line transmission line in power line communication, it is possible to select a channel without noise and to estimate the power line transmission line with high quality. Thereby, the narrow frequency band given to power line communication can be used effectively. In addition, since the switching mechanism 8 performs start / stop switch control of the digital amplifier unit 5 in conjunction with the folding opening / closing operation, a complicated operation for performing separate switch control becomes unnecessary, and the digital amplifier unit 5 is necessary. Sometimes it can function and can be used without the user's awareness.

  Further, since the digital amplifier unit 5 and the power line communication unit 6 are housed on the leading end sides of the first housing 2 and the second housing 3, respectively, the digital amplifier unit 5 and the power line communication unit are opened. 6 is obtained to the maximum, and the influence of noise can be further reduced. For this reason, it is not necessary to make the 1st housing | casing 2 and the 2nd housing | casing 3 into an expensive electromagnetic wave shielding case, and a merit is acquired in terms of cost or a shape.

  The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

In the above embodiment, a CD playback device or the like is adopted as the audio signal playback device of the transmission source. However, as another playback device, playback with a built-in HDD or non-volatile memory capable of storing and playing back audio data in MP3 format or the like. A player, personal computer, PDA, or the like may be used.
Further, Dolby (registered trademark) control, equalizer control, and the like may be performed by the power line communication sound reproducing device.

1 is a simplified cross-sectional view showing an open state in a power line communication sound reproducing device according to an embodiment of the present invention. In the power line communication sound reproducing apparatus of this embodiment, it is a simple sectional view showing a folded state. It is a flowchart of the transmission line setting in the power line communication sound reproduction apparatus of this embodiment. It is the figure which showed the waveform of the data at the time of performing data communication in the power line communication sound reproduction apparatus of this embodiment. It is a sequence diagram which shows the detailed flow of the process of a transmission line setting in the power line communication audio | voice reproduction apparatus of this embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Hinge part, 2 ... 1st housing | casing, 3 ... 2nd housing | casing, 4 ... Speaker part, 5 ... Digital amplifier part, 6 ... Power line communication part, 7 ... Power supply part, 8 ... Switching mechanism

Claims (3)

A first casing and a second casing that are foldably connected to each other by a hinge provided at a base end;
A speaker unit provided in the first housing;
A digital amplifier unit provided in the first housing and connected to the speaker unit;
A power line communication unit provided in the second casing and connected to a power line to receive an audio signal via the power line;
A power supply unit provided in the second housing and configured to supply power to the digital amplifier unit and the power line communication unit,
The power line communication sound reproducing apparatus, wherein each of the first casing and the second casing is an electromagnetic shielding case. In the power line communication sound reproducing device according to claim 1,
When only the power line communication unit is operated when the first casing and the second casing are closed in the folded state, and when the first casing and the second casing are opened. A power line communication sound reproducing apparatus, further comprising a switching mechanism capable of switching to operate the digital amplifier unit. The power line communication sound reproducing device according to claim 1 or 2,
The power line communication sound reproducing apparatus, wherein the digital amplifier section is housed on the distal end side of the first casing, and the power line communication section is housed on the distal end side of the second casing. .

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