JP2009238354A - Information reproducing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an information reproducing device (50) capable of performing a power source control for suppressing an unnecessary power consumption. <P>SOLUTION: The device is equipped with: a voice output unit (50b) for supplying a voice signal (MD1) to a reproducing signal output terminal (50a); a silence interval detecting unit (203) for detecting the silence interval of the voice signal (MD1); a recording unit (207) for recording the voice signal from speakers (51b, 51c) through the output terminal (50a) when the speakers (51b, 51c) are connected to the output terminal (50a); a control unit (208) for controlling an operation of the device itself; and a power source unit (201) for supplying the power to the device. The control unit (208) compares a sound pressure level of the recorded voice signal with a preliminarily set threshold to control the power supply of the power source unit (201) based on the comparison result. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an information reproducing apparatus, and more particularly to an information reproducing apparatus capable of listening to sound with connected headphones.

Information playback devices such as digital audio / video players and optical disk playback devices have become smaller and lighter and easier to carry.
Using such an information reproducing apparatus and headphones connected thereto, a lifestyle that enjoys music information, image information, and the like outdoors has become established.
In particular, since a portable information reproducing apparatus is usually driven by a battery, power control for enabling long-term use is important.

Therefore, a technique for controlling the power source of the information reproducing apparatus connected to the headphones so as not to perform a wasteful operation when not in use has been studied.
Specifically, it is a technology that detects whether or not headphones are attached to the head, and if not, the power is turned off and power consumption is reduced when not in use. 1 and Patent Document 2.

Japanese Patent Laid-Open No. 7-240989 JP-A-8-294191

Patent Document 1 discloses a technique for turning on / off a power switch using a pressing force applied to a head when headphones are attached to the head.
Since this technology requires a certain pressing force to operate the switch, an improvement is desired in that the user may not obtain a comfortable wearing feeling.

Patent Document 2 discloses a technique for turning on / off a power source by displacement of a headband when the head is mounted on the head.
This technique is desired to be improved in that the structure of the headband becomes complicated and the number of assembly steps increases.

  In addition, since the techniques described in these Patent Documents 1 and 2 require dedicated headphones, even when general-purpose headphones are used, power management is performed so as to suppress unnecessary power consumption. A playback device is desired.

  Accordingly, the problem to be solved by the present invention is to provide an information reproducing apparatus in which power management is performed so as to suppress unnecessary power consumption in an information reproducing apparatus capable of listening to sound using general-purpose headphones. There is.

In order to solve the above problems, the present invention has the following configurations 1) to 3) as means.
1) An output terminal (50a) for outputting a reproduced audio signal, an audio output unit (50b) for supplying the reproduced audio signal (MD1) to the output terminal (50a), and a silent section in the reproduced audio signal (MD1) In the silent section detected by the silent section detector (203) to be detected and the silent section detector (203), an electroacoustic transducer (51b, 51c) is connected to the output terminal (50a). In addition, a recording unit (207) that records an audio signal from the electroacoustic transducer (51b, 51c) via the output terminal (50a), and a control unit that controls the operation of the information reproducing device (50). (208) and a power supply unit (201) for supplying power to the information reproducing apparatus (50), and the control unit (208) is preset with a sound pressure level of the recorded audio signal. The information reproducing device (50) is characterized in that the power supply of the power supply unit (201) is controlled based on a comparison result with a threshold value.
2) When the recording unit (207) does not connect an electroacoustic transducer (51b, 51c) to the output terminal (50a) in the silent period detected by the silent period detection unit (203). The information reproducing apparatus (50) according to 1), which records a silence signal having a signal intensity level of zero.
3) The information reproduction device (50) according to 1), wherein the control unit (208) compares a sound pressure level in a high sound range of the recorded audio signal with the threshold value.

  According to the present invention, in an information reproducing apparatus that can listen to sound using headphones, there is an effect that power management is performed so as to suppress unnecessary power consumption even if general-purpose headphones are used.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to FIGS.

A portable music playback device 50 will be described as an embodiment of the information playback device of the present invention.
FIG. 1 shows a portable music player 50 according to an embodiment and a headphone 51 connected thereto.
Specifically, the plug 51 a of the headphone 51 is connected to the output terminal 50 a provided in the portable music playback device 50, and the audio signal output from the portable music playback device 50 can be listened to by the headphones 50.

  In FIG. 1, a headphone 51 is an inner ear type having two speaker portions 51b and 51c. The headphone 51 is not limited to this, and may be an overhead type having a headband or a monaural type having one speaker unit.

FIG. 2 is a block diagram for explaining the configuration of the portable music playback device 50.
The portable music player 50 includes a power supply unit 201, a storage unit 202, a reading unit 203, a decoding unit 204, a D / A conversion unit 205, a control unit 208, an input operation unit 209, and a storage unit 207a. A recording unit 207, a mode switching unit (switch) 206, and an A / D conversion unit 210.
Here, the storage unit 202, the reading unit 203, the decoding unit 204, and the D / A conversion unit 205 are collectively referred to as an audio output unit 50b.

The portable music playback device 50 is configured to operate in two modes, a music playback mode and an audio recording mode.
The switching of the mode is automatically performed under the control of the control unit 208.

  Details of this configuration will be specifically described along the operation.

First, the storage unit 202 stores music data supplied from outside via an input terminal (not shown). This music data is uncompressed digital data or digital data compressed in a compressed audio file format such as MP3 (MPEG AUDIO LAYER-3).
And before music reproduction, under the control of the control unit 208, the mode switching unit 206 sets the music reproduction mode (the switch shown in FIG. 2 is in the lower state).

  Here, when a user designates a song to be played and an instruction to play the song through the input operation unit 209, the control unit 208 sends the reading unit 203, the decoding unit 204, and the mode switching unit 206. On the other hand, it is instructed to read the music data MD1 designated by the user from the music data stored in the storage unit 202, and further output it from the output terminal 50a as an analog audio signal after decoding and D / A conversion. .

  When the reproduction of the designated music is finished, the control unit 208 instructs the mode switching unit 206 to switch to the music recording mode (the switch shown in FIG. 2 is in the upper side).

  The switching to the music recording mode and the operation of the music recording mode will be described using the flowchart of FIG.

  When the reproduction of the designated music is completed, the control unit 208 first inserts a silent section of a predetermined time. The silent section is inserted by outputting silent data from the storage unit 202 to the reading unit 203. The predetermined time is, for example, 2 seconds.

In the reading unit 203, this silent section is detected (S301).
When the silent section is detected by the reading unit 203, the control unit 208 switches the mode switching unit 206 to the sound recording mode (S302).
In the audio recording mode, the control unit 208 regards the output terminal 50a as an input terminal and performs audio recording for a predetermined time (S303). The predetermined time is, for example, 1 second.

This audio recording utilizes the fact that the speaker is a so-called electroacoustic transducer, and the vibration of the diaphragm is output as an electric signal and also functions as a microphone.
Specifically, the speaker units 51a and 51b of the headphone 51 connected to the output terminal 50a are caused to function as microphones, and the audio collected by the speaker units 51a and 51b is recorded and stored in the storage unit 207a of the recording unit 207. It is something to be made.
The recorded voice is stored as an analog signal or as a digital signal after A / D conversion. The digital signal to be stored may remain uncompressed or may be compressed.

  The recording unit 207 evaluates the recorded audio stored in the storage unit 207a according to the following procedure.

First, it is evaluated whether or not the signal level of the recorded audio is less than a predetermined value (smaller than a predetermined value) set in advance (S304).
If the signal level of the recorded voice is equal to or higher than the predetermined value (S304-No), it is determined that the headphones 50 are removed from the head and recording external noise, that is, a non-wearing state, and the determination result is controlled. The data is output to the unit 208.
Based on the determination result, the control unit 208 instructs the power supply unit 201 to turn off the power or enter the power saving mode (S305).

  If the signal level of the recorded audio is less than the predetermined value set in advance (S304-Yes), it is next determined whether or not the signal level is 0 (no signal level) ( In step S306, the determination result is output to the control unit 208.

  If it is determined that the signal level of the recorded audio is a non-signal level (S306-Yes), the control unit 208 turns off the power supply unit 201 or sets the power-saving mode based on the determination result. An instruction is given (S305).

  If it is determined that the signal level of the recorded audio is not a non-signal level (No in S306), the control unit 208 converts the recorded audio from the time domain to the frequency domain, and determines whether the headphones 50 are in a non-wearing state or a wearing state. To do.

  This determination is performed by the following procedure.

When sound is recorded with the headphones 50 not worn, sound in the space opened by the speaker units 50b and 50c is recorded.
On the other hand, when sound is recorded with the headphones 50 attached to the head (or ear), sound in a space sealed by the speaker portions 50b and 50c and the head or ear (auricle) is recorded. . The sound recorded in this sealed space has a lower sound pressure level in comparison with the sound recorded in the open space, and becomes a sound that is audible. That is, the frequency characteristics of the sound pressure levels of the two are different, and in particular, a remarkable difference is recognized for the high sound range.

FIG. 4 is a frequency characteristic diagram of the sound pressure level in the recorded sound when the headphones 50 are worn and not worn.
As can be seen from FIG. 4, there is a significant difference in the sound pressure level in the vicinity of 20 kHz as shown in part A.
Specifically, the sound pressure level is lower when attached than when not attached (when removed).

  Therefore, by utilizing this characteristic difference and evaluating the power spectrum of the high sound range with respect to the frequency region (middle low sound region) where the difference is not so remarkable, the headphone 50 is relatively worn or not worn. Can be determined.

  In the embodiment, specifically, the control unit 208 sets the high frequency range fh of the frequency domain obtained by FET-converting the recorded audio to 20 kHz to 21 kHz, and sets the peak value of the power spectrum of the high frequency range fh and the other frequency range fm. As 10 kHz to 11 kHz, it is evaluated whether or not the difference between the peak value of the power spectrum in the region fm is equal to or greater than a preset threshold value.

  If this difference is greater than or equal to the threshold value, it is determined that the sound pressure level in the high frequency range has been lowered and the headphones 50 are in the wearing state (S307-No). It is determined that the decrease in the sound pressure level is not significant and the headphones 50 are not worn (S307-Yes).

  When the control unit 208 determines that the headphones 50 are in the wearing state (S307-No), the control unit 208 maintains the power supply operation of the device itself, and when determining that the headphones 50 are in the non-wearing state (S307-Yes), An instruction is issued to turn off the power or enter the power saving mode (S305). The power saving mode is a mode in which, for example, only the minimum necessary power for accepting the next operation is supplied.

  According to such control of the control unit 208, for example, when the headphones 50 are removed from the head during music playback, when playback of the music being played back at that time is finished, the power is turned off. Or, since it automatically shifts to the power saving mode, it is possible to suppress wasteful power consumption of the power source (battery).

When the headphones have two speaker units (51b, 51c) as in the headphone 51 of the embodiment, the audio recording may be performed by recording the audio signal output from one of the speakers as a representative.
In addition, when two are recorded independently, if at least one is determined to be attached, it is determined to be in use, and only when both are determined to be not attached, the power is turned off or power saving It is desirable to switch to the mode.

In addition, when the plug 50a of the headphone 50 is removed from the output terminal during music reproduction, the recorded sound is silent (the signal intensity level is zero). In this case, the determination S304 in FIG. 3 is Yes, and the next determination S306 is Yes.
Accordingly, when the reproduction of the music that was being played when the plug 50a is removed is completed, the power is turned off or the power saving mode is automatically entered in step S305, and unauthorized power consumption of the power supply (battery) is performed. Can be suppressed.

  The silence in determination S306 may not be completely zero, and even a very small value may be treated as silence.

  Since the frequency band set in the high frequency range fh, the other frequency range fm, the threshold value, and the like differ depending on the acoustic characteristics of the music reproducing device 50 and the acoustic characteristics of the speaker units 50b and 50c of the headphones 50, The values are not limited to those described above.

  Further, the peak value of the power spectrum in the high sound range fh varies depending on the acoustic characteristics of the speaker units 50b and 50c and the degree of sealing of the sealed space in which sound is recorded in the mounted state. It is more preferable if it is configured to learn.

  That is, in the above-described example, when the reproduction of the music is finished, the control unit automatically switches to the sound recording mode. However, the optimum frequency band (high range fh and In order to optimize other frequency regions fm), peak values, threshold values, etc., for example, when using different headphones for the first time, the mode is switched to the sound recording mode according to the user's instruction and the headphones are worn. And the state of non-wearing may be recorded while making a guide announcement to the user.

  If this operation is referred to as an optimization mode, this optimization mode allows not only the use of general-purpose headphones, but also the acoustic characteristics of the headphones and the degree of close contact with the ears and head of the speaker when worn, It is possible to determine mounting / non-mounting with high accuracy and to execute power management of the information reproducing apparatus itself.

  The embodiment of the present invention is not limited to the configuration and procedure described above, and it goes without saying that modifications may be made without departing from the scope of the present invention.

The information reproducing apparatus is not limited to the portable music reproducing apparatus described in the embodiments.
The music data is not limited to the data stored in the storage unit.
Needless to say, the present invention can also be applied to an apparatus that receives a broadcast and outputs an audio signal, such as a television or radio receiver.
A video / audio playback device that can also play back images may be used, and includes various electronic devices such as a radio device, a television device, a game machine, a personal computer, a disk playback device, an image display device, and a mobile phone. Of course, the music may be reproduction-only or the music can be recorded (stored).

In the above-described embodiment, the configuration has been described in which the silent section is detected and the sound recording mode is entered after the reproduction of the designated music is completed. However, when a predetermined silent section exists in the designated music, Alternatively, the silent section may be detected without waiting for the end of reproduction to shift to the audio recording mode.
This makes it possible to detect that the headphones are not worn in the middle, for example when the specified music is long, without replaying to the end of the music, thus further reducing unnecessary power consumption. More preferred.

It is a figure which shows the Example of the information reproduction apparatus of this invention, and the headphones connected to it. It is a block diagram for demonstrating the Example of the information reproduction apparatus of this invention. It is a flowchart for demonstrating operation | movement of the Example of the information reproduction apparatus of this invention. It is a frequency characteristic diagram for demonstrating the audio | voice recorded in the audio | voice recording mode in the Example of the information reproduction apparatus of this invention.

Explanation of symbols

50 Portable music playback device (information playback device)
50a Output terminal 50b Audio output unit 51 Headphone 51a Plug 51b, 51c Speaker unit 201 Power supply unit 202 Storage unit 203 Reading unit 204 Decoding unit 205 D / A conversion unit 206 Mode switching unit 207 Recording unit 207a Storage unit 208 Control unit 209 Input operation 210 A / D converter fh High frequency range fm Other frequency range

Claims (3)

An output terminal for outputting a playback audio signal;
An audio output unit for supplying a reproduced audio signal to the output terminal;
A silent section detector for detecting a silent section in the reproduced audio signal;
Recording in which the audio signal from the electroacoustic transducer is recorded via the output terminal when an electroacoustic transducer is connected to the output terminal in the silent period detected by the silent interval detector. And
A control unit for controlling the operation of the information reproducing apparatus;
A power supply unit for supplying power to the information reproducing apparatus,
The controller is
An information reproducing apparatus characterized in that the sound pressure level of the recorded audio signal is compared with a preset threshold value, and the power supply of the power supply unit is controlled based on the comparison result.   The recording unit records a silence signal having a signal intensity level of zero when an electroacoustic transducer is not connected to the output terminal in the silence period detected by the silence period detection unit. The information reproducing apparatus according to claim 1.   2. The information reproducing apparatus according to claim 1, wherein the control unit compares a sound pressure level in a high sound range of the recorded audio signal with the threshold value.

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