JPH01175490A - Remote control equipment with headphone - Google Patents

Remote control equipment with headphone

Info

Publication number
JPH01175490A
JPH01175490A JP62333709A JP33370987A JPH01175490A JP H01175490 A JPH01175490 A JP H01175490A JP 62333709 A JP62333709 A JP 62333709A JP 33370987 A JP33370987 A JP 33370987A JP H01175490 A JPH01175490 A JP H01175490A
Authority
JP
Japan
Prior art keywords
audio
remote control
signal
infrared
recording
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP62333709A
Other languages
Japanese (ja)
Inventor
Satoru Takeguchi
竹口 哲
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Fujitsu General Ltd
Original Assignee
Fujitsu General Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Fujitsu General Ltd filed Critical Fujitsu General Ltd
Priority to JP62333709A priority Critical patent/JPH01175490A/en
Publication of JPH01175490A publication Critical patent/JPH01175490A/en
Pending legal-status Critical Current

Links

Abstract

PURPOSE:To hear the sound having presence at a place away from a recorder by providing an infrared ray emitting element for a voice at a recording and reproducing device main body, providing an infrared ray receiving element for a voice at a remote control equipment and outputting the output of a demodulating circuit to a headphone. CONSTITUTION:A sound signal recording at a magnetic tape 11 is picked up as electric signal by a magnetic head 13 for a voice and outputted from an infrared ray emitting element 5 to the external part as the infrared ray signal over the carrier of several MHz. The infrared ray is received, converted to the electric signal by an infrared ray receiving element 21 for a voice, an FM demodulating circuit 23 demodulates the signal to the sound signal, the sound signal is amplified with a headphone amplifier 25, simultaneously, a resistance 24 for adjustment adjusts it to the suitable volume, balance and tone quality, and the voice is outputted from a wireless headphone 27.

Description

【発明の詳細な説明】 「産業上の利用分野」 本発明は音声・映像用のビデオテープ、ビデオディスク
、レーザーディスク、■=Fi用テープ等に録音された
音声をヘッドフォンで聴くためのヘソドフォン付きリモ
ートコントロール装置に関するものである。
[Detailed Description of the Invention] "Industrial Application Field" The present invention is equipped with a hesodophone for listening to audio recorded on audio/visual video tapes, video discs, laser discs, ■ = Fi tapes, etc. with headphones. This invention relates to a remote control device.

「従来の技術」 VTR等の再生音を臨場感を得ながらかつ周囲に迷惑が
かからないように聴く場合は、ヘッドフォン利用が有効
的であるが、従来はこのヘッドフォン(27)は第3図
に示すように、記録再生装置本体(1)のヘソドフォン
出力端子(33) (33)に長いケーブル(34)を
もって接続していた。そしてリモートコントロール装置
(18)(以下リモコン装置という)で停止、巻戻し、
再生等を操作を行うが、音量やバランスは記録再生装置
のところまで行って調節しなければならなかった。
``Prior art'' When listening to the reproduced sound of a VTR, etc. while getting a sense of reality while not disturbing those around you, it is effective to use headphones. It was connected to the hesodophone output terminal (33) (33) of the main body (1) of the recording/reproducing apparatus using a long cable (34). Then, use the remote control device (18) (hereinafter referred to as the remote control device) to stop, rewind,
Playback and other operations were performed, but the volume and balance had to be adjusted by going to the recording/playback device.

[発明が解決しようとする問題点」 ヘッドフォンを記録再生装置本体の出力端子にケーブル
で接続する方法はケーブルが短かすぎた場合は記録再生
装置本体から遠く離れた場所で聴くここができず、又ケ
ーブルが長すぎると近くで聴く場合にはケーブルが邪魔
になるという問題点があった。
[Problem to be solved by the invention] When connecting headphones to the output terminal of the recording/playback device using a cable, if the cable is too short, it may not be possible to listen to music from a distance from the recording/playback device. Another problem is that if the cable is too long, it will get in the way when listening to music from close quarters.

「問題点を解決するための手段」 本発明は前記問題点を解決するため発明されたもので、
音声信号の記録再生手段としてFMキャリアを用いた記
録再生装置本体と、この記録再生装置本体を操作するた
めの赤外線のリモートコントロール信号を発信するリモ
ートコントロール装置とを具備してなる記録再生装置に
おいて、前記記録再生装置本体に、音声のFM信号を取
り出して増幅する音声用赤外線発光素子駆動用増幅駆動
回路と、この増幅駆動回路により駆動されて赤外線によ
る音声のFM信号を発光する音声用赤外線発光素子とを
具備し、前記リモー1へコントロール装置に、前記音声
用赤外線発光素子からの信号を受光する音声用赤外線受
光素子と、この音声用赤外線受光素子で変換された電気
信号を音声信号に復調する復調回路と、この復調回路の
出力をヘッドフォン鄭動レベルに増幅する増幅回路と、
この増幅回路に結合されたヘラ1−フオン接続端子とを
具備してなるものである。
"Means for Solving the Problems" The present invention was invented to solve the problems mentioned above.
A recording and reproducing device comprising a recording and reproducing device main body that uses an FM carrier as an audio signal recording and reproducing means, and a remote control device that transmits an infrared remote control signal for operating the recording and reproducing device main body, The recording and reproducing apparatus main body includes an amplification drive circuit for driving an audio infrared light emitting element that extracts and amplifies an audio FM signal, and an audio infrared light emitting element that is driven by the amplification drive circuit and emits an infrared audio FM signal. The control device for the remote 1 includes an audio infrared receiving element that receives the signal from the audio infrared light emitting element, and demodulates the electrical signal converted by the audio infrared receiving element into an audio signal. a demodulation circuit; an amplifier circuit that amplifies the output of the demodulation circuit to a headphone driving level;
The amplifier circuit is equipped with a 1-phone connection terminal coupled to this amplifier circuit.

「作用」 本発明は上記の構成としたので、磁気テープ等に録音さ
れた音声信号は磁気ヘッド等のセンサで電気信号に変換
され、前置増幅器で前置増幅された後、音声用FM復調
回路に入る前にFM信号として取り出され、増幅駆動回
路で増幅されて音声用赤外線発光素子から数MHzのキ
ャリアにのった赤外線信号として出力される。この赤外
線信号を記録再生装置本体から離れた個所のリモコン装
置に具備した音声用赤外線受光素子で受信し、電気信号
に変換する。この電気信号をリモコン装置内の前置増幅
回路で増幅され、FM復調回路で音声信号に復調され、
さらに音声増幅される。この音声信号はリモコン装置に
接続されたヘソドフォンから出力する。また、テープ等
の停止、巻戻し、再生、音量調節、バランス調節等はリ
モコン装置に装着された操作釦によって行なう。
"Operation" Since the present invention has the above configuration, an audio signal recorded on a magnetic tape or the like is converted into an electrical signal by a sensor such as a magnetic head, preamplified by a preamplifier, and then FM demodulated for audio. Before entering the circuit, it is taken out as an FM signal, amplified by an amplification drive circuit, and output from an audio infrared light emitting element as an infrared signal on a carrier of several MHz. This infrared signal is received by an audio infrared receiving element provided in a remote control device located away from the main body of the recording/reproducing apparatus, and converted into an electrical signal. This electrical signal is amplified by a preamplifier circuit in the remote control device, demodulated into an audio signal by an FM demodulation circuit,
The sound is further amplified. This audio signal is output from a hesodophone connected to the remote control device. Further, operations such as stopping, rewinding, reproducing, adjusting the volume, and adjusting the balance of the tape are performed using operation buttons attached to the remote control device.

「実施例」 本発明をVTR用記録再生装置に利用したときの実施例
を第1図及び第2図に基づいて説明する。
"Embodiment" An embodiment in which the present invention is applied to a recording/reproducing apparatus for a VTR will be described based on FIGS. 1 and 2.

第1図において、(1)はVH5/Hj、−Fiステ1
iオの記録再生装置本体で、この記録再生装置本体(1
)にはテープ挿入口(2)の他に、音声用赤外線信号の
発光窓(3)とリモコン信号用赤外線信号の受光窓(4
)とが各々パネル(8)の表面に設けられている。
In Figure 1, (1) is VH5/Hj, -Fi step 1
This recording/playback device main body (1
) has a tape insertion slot (2), a light emitting window (3) for infrared signals for audio, and a light receiving window (4) for infrared signals for remote control signals.
) are respectively provided on the surface of the panel (8).

この発光窓(3)に臨ませて赤外線LED、レーザダイ
オード等からなる音声用赤外線発光素子(5)が発光面
を正面に向けて設けられている。この音声用赤外線発光
素子(5)はその発光面が上下左右に回転できるように
歯車、モータ等の機構からなる回転装置を設けてもよい
。前記受光窓(4)に臨ませてフォトトランジスタ、フ
ォトダイオード等からなるリモコン用赤外線受光素子(
7)がその受光面を正面に向けて記録再生装置本体(1
)の正面パネル(8)に固設されている。
Facing this light emitting window (3), an audio infrared light emitting element (5) consisting of an infrared LED, a laser diode, etc. is provided with its light emitting surface facing forward. This infrared light emitting element for audio (5) may be provided with a rotation device including a mechanism such as a gear or a motor so that its light emitting surface can rotate vertically and horizontally. An infrared receiving element (for remote control) consisting of a phototransistor, a photodiode, etc. is placed facing the light receiving window (4).
7) with its light-receiving surface facing the front.
) is fixedly installed on the front panel (8).

第2図は概略のブロック図で、(11)は記録再生装置
本体(1)に装着されたVTRのテープで、このテープ
(11)に接触するように映像用及び音声用の磁気ヘッ
ド(12)、(13)が記録再生装置本体(1)に固設
されている。音声用の磁気ヘッド(13)の出刃側はプ
リアンプ(15)に接続され、このプリアンプ(15)
の出力側は音声のFM復調回路(16)に接続されてい
る。前記プリアンプ(15)の出力側はまた増@駆動回
路(17)を介して前記音声用赤外線発光素子(5)に
接続されている。
FIG. 2 is a schematic block diagram, in which (11) is a VTR tape attached to the main body (1) of the recording/reproducing apparatus, and magnetic heads (12) for video and audio are placed in contact with this tape (11). ), (13) are fixedly installed on the main body (1) of the recording/reproducing apparatus. The blade side of the audio magnetic head (13) is connected to a preamplifier (15), and this preamplifier (15)
The output side of is connected to an audio FM demodulation circuit (16). The output side of the preamplifier (15) is also connected to the audio infrared light emitting element (5) via an amplifier drive circuit (17).

第1図および第2図において(18)はリモートコント
ロール装置(以下リモコン装置という)である。
In FIGS. 1 and 2, (18) is a remote control device (hereinafter referred to as a remote control device).

このリモコン装置(18)の正面には赤外線受光窓(1
9)と赤外線発光窓(20)が設けられている。この赤
外線受光窓(19)に臨ませてフォ1へトランジスタ、
フォトダイオード等からなる音声用赤外線受光素子(2
1)が受光面を正面に向けて固設されている。
The front of this remote control device (18) has an infrared receiving window (18).
9) and an infrared emitting window (20). Transistor to photo 1 facing this infrared receiving window (19),
Audio infrared receiving element (2) consisting of a photodiode, etc.
1) is fixedly installed with the light-receiving surface facing the front.

又リモコン装置(18)の赤外線発光窓(20)に臨ま
せて操作用赤外線発光素子(31)が固設されている。
Further, an infrared light emitting element (31) for operation is fixedly provided facing the infrared light emitting window (20) of the remote control device (18).

音声用赤外線受光素子(21)の出力端はプリアンプ(
22)を介して音声のFM復調回路(23)に接続され
ており、このFM復調回路(23)の出力端は音量、バ
ランス、音質等の調節用抵抗(24) (24)を介し
てヘソドフォンアンプ(25)に接続されている。この
ヘッドフォンアンプ(25)の出力端かヘッドフォン接
続用コネクタ(26)に接続され、このコネクタ(26
)にヘッドフォン(27)が着脱自在に接続される。
The output end of the audio infrared receiving element (21) is connected to the preamplifier (
22) to the audio FM demodulation circuit (23), and the output end of this FM demodulation circuit (23) is connected to the navel via a resistor (24) for adjusting volume, balance, sound quality, etc. It is connected to the phone amplifier (25). The output end of this headphone amplifier (25) is connected to the headphone connection connector (26).
) is detachably connected to headphones (27).

前記リモコン装置(18)の上面には操作釦(28)が
複数個設けられている。この操作釦(28)の出力側は
エンコーダ回路(29)、リモコン用送信回路(30)
を介して前記操作用赤外線発光素子(31)に接続され
ている。
A plurality of operation buttons (28) are provided on the top surface of the remote control device (18). The output side of this operation button (28) is an encoder circuit (29) and a remote control transmitter circuit (30).
It is connected to the operating infrared light emitting element (31) via.

さらに、前記記録再生装置本体(1)のリモコン用赤外
線受光素子(7)の出力端はシステムコン1へロール回
路(32)に接続され、このシステムコン1〜ロール回
路(32)はサーボ系、信号処理系に接続されている。
Further, the output end of the remote control infrared receiving element (7) of the recording/reproducing apparatus main body (1) is connected to the roll circuit (32) to the system controller 1, and the system controller 1 to the roll circuit (32) are connected to the servo system, Connected to the signal processing system.

以下、本発明の作用を上記構成に基づき説明する。Hereinafter, the operation of the present invention will be explained based on the above configuration.

磁気テープ(11)に記録されている音声信号は、音声
用磁気ヘッド(13)によって電気信号としてピックア
ップされ、この電気信号はプリアンプ(15)によって
処理し易いレベルに増幅される。この増幅された電気信
号は増幅暉動回路(17)でさらに増幅され、音声用赤
外線発光素子(5)から数MT(zのキヤリアにのった
赤外線信号として外部に出力される。この赤外線受光窓
(19)を音声用赤外線発光素子(5)からの赤外線の
進路に向けておくと、この赤外線信号が音声用赤外線受
光素子(21)によって受光され電気信号に変換される
。この電気信号をプリアンプ(22)で増幅し、FM復
調回路(23)によって音声信号に復調し、この音声信
号をヘソドフォンアンプ(25)で増幅すると同時に調
節用抵抗(24)で適当な音量、バランス、音質に調節
し、ワイヤレスヘッドフォン(27)から音声を出力す
る。
The audio signal recorded on the magnetic tape (11) is picked up as an electrical signal by an audio magnetic head (13), and this electrical signal is amplified by a preamplifier (15) to a level that is easy to process. This amplified electric signal is further amplified by the amplification and perturbation circuit (17), and outputted from the audio infrared light emitting element (5) as an infrared signal on a carrier of several MT (z). When the window (19) is directed toward the path of the infrared rays from the audio infrared light emitting element (5), this infrared signal is received by the audio infrared receiver (21) and converted into an electrical signal.This electrical signal is It is amplified by a preamplifier (22), demodulated into an audio signal by an FM demodulation circuit (23), and this audio signal is amplified by a hesodophone amplifier (25), while at the same time adjusting the volume, balance, and sound quality to an appropriate level using an adjustment resistor (24). and output audio from the wireless headphones (27).

なお、記録再生装置本体(1)から離れた場所からテー
プ(11)の即動停止、巻戻し、再生その他の操作は従
来技術を利用して行なうことができる。
It should be noted that immediate stopping, rewinding, reproducing, and other operations of the tape (11) can be performed from a location away from the main body (1) of the recording/reproducing apparatus using conventional techniques.

即ち、リモコン装置(18)の上面に設けられた操作釦
(28)を押すと、該当する命令の操作信号がリモコン
用赤外線発光素子(31)から約40KI(zの赤外線
信号として出力される。この赤外線信号を操作用赤外線
受光素子(7)で受信し、電気信号に変換する。この電
気信号によってシステムコントロール回路(32)から
各種の制御信号が出力され、制御が行なわれる。
That is, when the operation button (28) provided on the top surface of the remote control device (18) is pressed, an operation signal of the corresponding command is output from the remote control infrared light emitting element (31) as an infrared signal of approximately 40 KI (z). This infrared signal is received by the operating infrared light receiving element (7) and converted into an electrical signal. Various control signals are outputted from the system control circuit (32) based on this electrical signal, and control is performed.

この操作用の赤外線信号と音声用の赤外線信号は略平行
な進路となるが、キャリアの周波数が異なり相互に悪影
響を及ぼすことはない。
The infrared signal for operation and the infrared signal for audio follow approximately parallel paths, but the carrier frequencies are different and they do not adversely affect each other.

前記実施例ではVH5方式のHi−Fjステレオの場合
を説明したが、これに限るものでな(8+nmHj−F
jモノラルの場合、レーザディスク音声FMステレオの
場合であってもよい。
In the above embodiment, the case of Hi-Fj stereo of VH5 system was explained, but it is not limited to this (8+nmHj-Fj
In the case of j monaural, it may be in the case of laser disc audio FM stereo.

「発明の効果」 本発明は上記の通り構成したので、ヘッドフォンには長
いケーブルが付いていないので記録装置から離れた場所
で臨場感のある音を聴くことができ、しかも身動きが自
由である。
"Effects of the Invention" Since the present invention is constructed as described above, the headphones do not have long cables, so it is possible to listen to realistic sound at a location far from the recording device, and moreover, the user can move freely.

【図面の簡単な説明】[Brief explanation of the drawing]

第1図は本発明によるヘッドフォン付きリモートコン1
−ロール装置の一実施例の説明図、第2図は同実施例の
概略の構成を示すブロック図、第3図は従来技術の構成
を示すブロック図である。 (1)・記録再生装置本体、(3)・・音声用赤外線信
号発光窓、(4)・ リモコン信号用赤外線信号受光窓
、(5)・・・音声用赤外線受光素子、(7)・・・リ
モコン用赤外線受光素子、(17)・・・増幅駆動回路
、(18)・・リモコン装置、(21)・・・音声用赤
外線受光素子、(23)・・・FM復調回路、(24)
・・調節用抵抗、(31)・・・リモコン用赤外線発光
素子。 出願人 株式会社富士通ゼネラル 一   −
Figure 1 shows a remote controller 1 with headphones according to the present invention.
- An explanatory diagram of an embodiment of the roll device, FIG. 2 is a block diagram showing the general configuration of the same embodiment, and FIG. 3 is a block diagram showing the configuration of a conventional technique. (1) Recording/playback device body, (3) Audio infrared signal emitting window, (4) Remote control signal infrared signal receiving window, (5) Audio infrared receiving element, (7)... - Infrared light receiving element for remote control, (17)...Amplification drive circuit, (18)...Remote control device, (21)...Infrared light receiving element for audio, (23)...FM demodulation circuit, (24)
...Adjustment resistor, (31)...Infrared light emitting element for remote control. Applicant: Fujitsu General Limited -

Claims (5)

【特許請求の範囲】[Claims] (1)音声信号の記録再生手段としてFMキャリアを用
いた記録再生装置本体と、この記録再生装置本体を操作
するための赤外線のリモートコントロール信号を発信す
るリモートコントロール装置とを具備してなる記録再生
装置において、前記記録再生装置本体に、音声のFM信
号を取り出して増幅する音声用赤外線発光素子駆動用増
幅駆動回路と、この増幅駆動回路により駆動されて赤外
線による音声のFM信号を発光する音声用赤外線発光素
子とを具備し、前記リモートコントロール装置に、前記
音声用赤外線発光素子からの信号を受光する音声用赤外
線受光素子と、この音声用赤外線受光素子で変換された
電気信号を音声信号に復調する復調回路と、この復調回
路の出力をヘッドフォン駆動レベルに増幅する増幅回路
と、この増幅回路に結合されたヘッドフオン接続端子と
を具備してなることを特徴とするヘッドフォン付きリモ
ートコントロール装置。
(1) A recording and reproducing device comprising a recording and reproducing device that uses an FM carrier as a means for recording and reproducing audio signals, and a remote control device that transmits an infrared remote control signal for operating the recording and reproducing device. In the apparatus, the recording/reproducing apparatus main body includes an amplification drive circuit for driving an audio infrared light emitting element that extracts and amplifies an audio FM signal, and an audio amplifier that is driven by the amplification drive circuit to emit an audio FM signal using infrared rays. an infrared light emitting element for sound, the remote control device includes an infrared light receiving element for sound that receives a signal from the infrared light light emitting element for sound, and demodulates the electrical signal converted by the infrared light receiving element for sound into an audio signal. 1. A remote control device with headphones, comprising: a demodulation circuit that amplifies the output of the demodulation circuit to a headphone drive level; and a headphone connection terminal coupled to the amplification circuit.
(2)音声用赤外線発光素子は赤外線LEDからなる特
許請求の範囲第1項記載のヘッドフォン付きリモートコ
ントロール装置。
(2) The remote control device with headphones according to claim 1, wherein the infrared light emitting element for sound is an infrared LED.
(3)音声用赤外線発光素子はレーザダイオードからな
る特許請求の範囲第1項記載のヘッドフオン付きリモー
トコントロール装置。
(3) The remote control device with headphones according to claim 1, wherein the infrared light emitting element for audio is a laser diode.
(4)音声用赤外線受光素子はフォトトランジスタから
なる特許請求の範囲第1項、第2項または第3項記載の
ヘッドフォン付きリモートコントロール装置。
(4) A remote control device with headphones according to claim 1, 2 or 3, wherein the audio infrared receiving element is a phototransistor.
(5)音声用赤外線受光素子はフォトダイオードからな
る特許請求の範囲第1項、第2項または第3項記載のヘ
ッドフオン付きリモートコントロール装置。
(5) A remote control device with headphones according to claim 1, 2 or 3, wherein the audio infrared receiving element is a photodiode.
JP62333709A 1987-12-29 1987-12-29 Remote control equipment with headphone Pending JPH01175490A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP62333709A JPH01175490A (en) 1987-12-29 1987-12-29 Remote control equipment with headphone

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP62333709A JPH01175490A (en) 1987-12-29 1987-12-29 Remote control equipment with headphone

Publications (1)

Publication Number Publication Date
JPH01175490A true JPH01175490A (en) 1989-07-11

Family

ID=18269087

Family Applications (1)

Application Number Title Priority Date Filing Date
JP62333709A Pending JPH01175490A (en) 1987-12-29 1987-12-29 Remote control equipment with headphone

Country Status (1)

Country Link
JP (1) JPH01175490A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2002089475A3 (en) * 2001-05-01 2003-02-13 Koninkl Philips Electronics Nv System for recording and reading audiovisual information
GB2397186A (en) * 2003-01-07 2004-07-14 Punch Video Inc LCD display with an infrared transmission interface for transmitting audio signals in stereo

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2002089475A3 (en) * 2001-05-01 2003-02-13 Koninkl Philips Electronics Nv System for recording and reading audiovisual information
GB2397186A (en) * 2003-01-07 2004-07-14 Punch Video Inc LCD display with an infrared transmission interface for transmitting audio signals in stereo

Similar Documents

Publication Publication Date Title
US6614912B1 (en) Sound reproducing device, earphone device and signal processing device therefor
CA2295092C (en) System for producing an artificial sound environment
US5781850A (en) Live voice device for cellular phones particularly operable in combination with radio receiver apparatus in motor vehicles
AU3724489A (en) Tape recording and/or reproducing apparatus
US4095261A (en) Audio tape recorder, editor and amplifying system
JPH01175492A (en) Remote control equipment with headphone
US4287388A (en) Drive-in theatre sound distribution system
JPH01175490A (en) Remote control equipment with headphone
JP2792217B2 (en) Remote control device
JPH01175491A (en) Remote control equipment with headphone
US4395739A (en) Recording/reproducing apparatus with selective attenuation of reproduced signals to facilitate comprehension of external speech signals
US5361378A (en) Camcorder stereo mic/phones
KR960012402B1 (en) Recording method and recording carrier for learning language device
US3475564A (en) System for selectively reproducing signals recorded at different levels
US3047670A (en) Educational doll
JPH0739067Y2 (en) Wireless headphone stereo
KR100902356B1 (en) Earphone
JPH0166695U (en)
JP4150319B2 (en) Headphone device
KR960004962B1 (en) Adaptive volume auto-regulating device in audio apparatus
JPS6235186Y2 (en)
JP2502086Y2 (en) Sound reproduction device
GB2201068A (en) Speaking toy
KR910003611Y1 (en) Audio output automatic control circuit
KR900007918Y1 (en) A headphone with a receiver